/*
- * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2004-2011 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
+ *
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
- *
+ *
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
+ *
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
- *
+ *
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
-
/*
- * Kernel Authorization framework: Management of process/thread credentials and identity information.
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
*/
+/*
+ * Kernel Authorization framework: Management of process/thread credentials
+ * and identity information.
+ */
-#include <sys/param.h> /* XXX trim includes */
+#include <sys/param.h> /* XXX trim includes */
#include <sys/acct.h>
#include <sys/systm.h>
#include <sys/ucred.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
+#include <sys/sdt.h>
-#include <bsm/audit_kernel.h>
+#include <security/audit/audit.h>
#include <sys/mount.h>
+#include <sys/stat.h> /* For manifest constants in posix_cred_access */
#include <sys/sysproto.h>
#include <mach/message.h>
#include <mach/host_security.h>
-#include <libkern/OSAtomic.h>
+#include <machine/atomic.h>
#include <kern/task.h>
-#include <kern/lock.h>
+#include <kern/locks.h>
#ifdef MACH_ASSERT
# undef MACH_ASSERT
#endif
-#define MACH_ASSERT 1 /* XXX so bogus */
+#define MACH_ASSERT 1 /* XXX so bogus */
#include <kern/assert.h>
-#define CRED_DIAGNOSTIC 1
+#if CONFIG_MACF
+#include <security/mac.h>
+#include <security/mac_framework.h>
+#include <security/_label.h>
+#endif
+
+#include <IOKit/IOBSD.h>
+
+void mach_kauth_cred_uthread_update( void );
+
+# define NULLCRED_CHECK(_c) do {if (!IS_VALID_CRED(_c)) panic("%s: bad credential %p", __FUNCTION__,_c);} while(0)
+
+/* Set to 1 to turn on KAUTH_DEBUG for kern_credential.c */
+#if 0
+#ifdef KAUTH_DEBUG
+#undef KAUTH_DEBUG
+#endif
+
+#ifdef K_UUID_FMT
+#undef K_UUID_FMT
+#endif
+
+#ifdef K_UUID_ARG
+#undef K_UUID_ARG
+#endif
+
+# define K_UUID_FMT "%08x:%08x:%08x:%08x"
+# define K_UUID_ARG(_u) &_u.g_guid_asint[0],&_u.g_guid_asint[1],&_u.g_guid_asint[2],&_u.g_guid_asint[3]
+# define KAUTH_DEBUG(fmt, args...) do { printf("%s:%d: " fmt "\n", __PRETTY_FUNCTION__, __LINE__ , ##args); } while (0)
+#endif
+
+/*
+ * Credential debugging; we can track entry into a function that might
+ * change a credential, and we can track actual credential changes that
+ * result.
+ *
+ * Note: Does *NOT* currently include per-thread credential changes
+ */
+
+#if DEBUG_CRED
+#define DEBUG_CRED_ENTER printf
+#define DEBUG_CRED_CHANGE printf
+extern void kauth_cred_print(kauth_cred_t cred);
+
+#include <libkern/OSDebug.h> /* needed for get_backtrace( ) */
+
+int is_target_cred( kauth_cred_t the_cred );
+void get_backtrace( void );
+
+static int sysctl_dump_creds( __unused struct sysctl_oid *oidp, __unused void *arg1,
+ __unused int arg2, struct sysctl_req *req );
+static int
+sysctl_dump_cred_backtraces( __unused struct sysctl_oid *oidp, __unused void *arg1,
+ __unused int arg2, struct sysctl_req *req );
+
+#define MAX_STACK_DEPTH 8
+struct cred_backtrace {
+ int depth;
+ void * stack[MAX_STACK_DEPTH];
+};
+typedef struct cred_backtrace cred_backtrace;
+
+#define MAX_CRED_BUFFER_SLOTS 200
+struct cred_debug_buffer {
+ int next_slot;
+ cred_backtrace stack_buffer[MAX_CRED_BUFFER_SLOTS];
+};
+typedef struct cred_debug_buffer cred_debug_buffer;
+cred_debug_buffer * cred_debug_buf_p = NULL;
+
+#else /* !DEBUG_CRED */
+
+#define DEBUG_CRED_ENTER(fmt, ...) do {} while (0)
+#define DEBUG_CRED_CHANGE(fmt, ...) do {} while (0)
-# define NULLCRED_CHECK(_c) do {if (!IS_VALID_CRED(_c)) panic("bad credential %p", _c);} while(0)
+#endif /* !DEBUG_CRED */
+#if CONFIG_EXT_RESOLVER
/*
* Interface to external identity resolver.
*
- * The architecture of the interface is simple; the external resolver calls in to
- * get work, then calls back with completed work. It also calls us to let us know
- * that it's (re)started, so that we can resubmit work if it times out.
+ * The architecture of the interface is simple; the external resolver calls
+ * in to get work, then calls back with completed work. It also calls us
+ * to let us know that it's (re)started, so that we can resubmit work if it
+ * times out.
*/
static lck_mtx_t *kauth_resolver_mtx;
-#define KAUTH_RESOLVER_LOCK() lck_mtx_lock(kauth_resolver_mtx);
-#define KAUTH_RESOLVER_UNLOCK() lck_mtx_unlock(kauth_resolver_mtx);
+#define KAUTH_RESOLVER_LOCK() lck_mtx_lock(kauth_resolver_mtx);
+#define KAUTH_RESOLVER_UNLOCK() lck_mtx_unlock(kauth_resolver_mtx);
-static volatile pid_t kauth_resolver_identity;
-static int kauth_resolver_registered;
-static uint32_t kauth_resolver_sequence;
+static volatile pid_t kauth_resolver_identity;
+static int kauth_identitysvc_has_registered;
+static int kauth_resolver_registered;
+static uint32_t kauth_resolver_sequence;
+static int kauth_resolver_timeout = 30; /* default: 30 seconds */
struct kauth_resolver_work {
TAILQ_ENTRY(kauth_resolver_work) kr_link;
struct kauth_identity_extlookup kr_work;
- uint32_t kr_seqno;
- int kr_refs;
- int kr_flags;
-#define KAUTH_REQUEST_UNSUBMITTED (1<<0)
-#define KAUTH_REQUEST_SUBMITTED (1<<1)
-#define KAUTH_REQUEST_DONE (1<<2)
- int kr_result;
+ uint64_t kr_extend;
+ uint32_t kr_seqno;
+ int kr_refs;
+ int kr_flags;
+#define KAUTH_REQUEST_UNSUBMITTED (1<<0)
+#define KAUTH_REQUEST_SUBMITTED (1<<1)
+#define KAUTH_REQUEST_DONE (1<<2)
+ int kr_result;
};
TAILQ_HEAD(kauth_resolver_unsubmitted_head, kauth_resolver_work) kauth_resolver_unsubmitted;
-TAILQ_HEAD(kauth_resolver_submitted_head, kauth_resolver_work) kauth_resolver_submitted;
-TAILQ_HEAD(kauth_resolver_done_head, kauth_resolver_work) kauth_resolver_done;
+TAILQ_HEAD(kauth_resolver_submitted_head, kauth_resolver_work) kauth_resolver_submitted;
+TAILQ_HEAD(kauth_resolver_done_head, kauth_resolver_work) kauth_resolver_done;
+
+/* Number of resolver timeouts between logged complaints */
+#define KAUTH_COMPLAINT_INTERVAL 1000
+int kauth_resolver_timeout_cnt = 0;
+
+#if DEVELOPMENT || DEBUG
+/* Internal builds get different (less ambiguous) breadcrumbs. */
+#define KAUTH_RESOLVER_FAILED_ERRCODE EOWNERDEAD
+#else
+/* But non-Internal builds get errors that are allowed by standards. */
+#define KAUTH_RESOLVER_FAILED_ERRCODE EIO
+#endif /* DEVELOPMENT || DEBUG */
+
+int kauth_resolver_failed_cnt = 0;
+#define RESOLVER_FAILED_MESSAGE(fmt, args...) \
+do { \
+ if (!(kauth_resolver_failed_cnt++ % 100)) { \
+ printf("%s: " fmt "\n", __PRETTY_FUNCTION__, ##args); \
+ } \
+} while (0)
+
+static int kauth_resolver_submit(struct kauth_identity_extlookup *lkp, uint64_t extend_data);
+static int kauth_resolver_complete(user_addr_t message);
+static int kauth_resolver_getwork(user_addr_t message);
+static int kauth_resolver_getwork2(user_addr_t message);
+static __attribute__((noinline)) int __KERNEL_IS_WAITING_ON_EXTERNAL_CREDENTIAL_RESOLVER__(
+ struct kauth_resolver_work *);
+
+#define KAUTH_CACHES_MAX_SIZE 10000 /* Max # entries for both groups and id caches */
+
+struct kauth_identity {
+ TAILQ_ENTRY(kauth_identity) ki_link;
+ int ki_valid;
+ uid_t ki_uid;
+ gid_t ki_gid;
+ int ki_supgrpcnt;
+ gid_t ki_supgrps[NGROUPS];
+ guid_t ki_guid;
+ ntsid_t ki_ntsid;
+ const char *ki_name; /* string name from string cache */
+ /*
+ * Expiry times are the earliest time at which we will disregard the
+ * cached state and go to userland. Before then if the valid bit is
+ * set, we will return the cached value. If it's not set, we will
+ * not go to userland to resolve, just assume that there is no answer
+ * available.
+ */
+ time_t ki_groups_expiry;
+ time_t ki_guid_expiry;
+ time_t ki_ntsid_expiry;
+};
+
+static TAILQ_HEAD(kauth_identity_head, kauth_identity) kauth_identities;
+static lck_mtx_t *kauth_identity_mtx;
+#define KAUTH_IDENTITY_LOCK() lck_mtx_lock(kauth_identity_mtx);
+#define KAUTH_IDENTITY_UNLOCK() lck_mtx_unlock(kauth_identity_mtx);
+#define KAUTH_IDENTITY_CACHEMAX_DEFAULT 100 /* XXX default sizing? */
+static int kauth_identity_cachemax = KAUTH_IDENTITY_CACHEMAX_DEFAULT;
+static int kauth_identity_count;
+
+static struct kauth_identity *kauth_identity_alloc(uid_t uid, gid_t gid, guid_t *guidp, time_t guid_expiry,
+ ntsid_t *ntsidp, time_t ntsid_expiry, int supgrpcnt, gid_t *supgrps, time_t groups_expiry,
+ const char *name, int nametype);
+static void kauth_identity_register_and_free(struct kauth_identity *kip);
+static void kauth_identity_updatecache(struct kauth_identity_extlookup *elp, struct kauth_identity *kip, uint64_t extend_data);
+static void kauth_identity_trimcache(int newsize);
+static void kauth_identity_lru(struct kauth_identity *kip);
+static int kauth_identity_guid_expired(struct kauth_identity *kip);
+static int kauth_identity_ntsid_expired(struct kauth_identity *kip);
+static int kauth_identity_find_uid(uid_t uid, struct kauth_identity *kir, char *getname);
+static int kauth_identity_find_gid(gid_t gid, struct kauth_identity *kir, char *getname);
+static int kauth_identity_find_guid(guid_t *guidp, struct kauth_identity *kir, char *getname);
+static int kauth_identity_find_ntsid(ntsid_t *ntsid, struct kauth_identity *kir, char *getname);
+static int kauth_identity_find_nam(char *name, int valid, struct kauth_identity *kir);
-static int kauth_resolver_submit(struct kauth_identity_extlookup *lkp);
-static int kauth_resolver_complete(user_addr_t message);
-static int kauth_resolver_getwork(user_addr_t message);
+struct kauth_group_membership {
+ TAILQ_ENTRY(kauth_group_membership) gm_link;
+ uid_t gm_uid; /* the identity whose membership we're recording */
+ gid_t gm_gid; /* group of which they are a member */
+ time_t gm_expiry; /* TTL for the membership, or 0 for persistent entries */
+ int gm_flags;
+#define KAUTH_GROUP_ISMEMBER (1<<0)
+};
+
+TAILQ_HEAD(kauth_groups_head, kauth_group_membership) kauth_groups;
+static lck_mtx_t *kauth_groups_mtx;
+#define KAUTH_GROUPS_LOCK() lck_mtx_lock(kauth_groups_mtx);
+#define KAUTH_GROUPS_UNLOCK() lck_mtx_unlock(kauth_groups_mtx);
+#define KAUTH_GROUPS_CACHEMAX_DEFAULT 100 /* XXX default sizing? */
+static int kauth_groups_cachemax = KAUTH_GROUPS_CACHEMAX_DEFAULT;
+static int kauth_groups_count;
+
+static int kauth_groups_expired(struct kauth_group_membership *gm);
+static void kauth_groups_lru(struct kauth_group_membership *gm);
+static void kauth_groups_updatecache(struct kauth_identity_extlookup *el);
+static void kauth_groups_trimcache(int newsize);
-#define KAUTH_CRED_PRIMES_COUNT 7
-static const int kauth_cred_primes[KAUTH_CRED_PRIMES_COUNT] = {97, 241, 397, 743, 1499, 3989, 7499};
-static int kauth_cred_primes_index = 0;
-static int kauth_cred_table_size = 0;
+#endif /* CONFIG_EXT_RESOLVER */
-TAILQ_HEAD(kauth_cred_entry_head, ucred);
-static struct kauth_cred_entry_head * kauth_cred_table_anchor = NULL;
+#define KAUTH_CRED_TABLE_SIZE 128
-#define KAUTH_CRED_HASH_DEBUG 0
+LIST_HEAD(kauth_cred_entry_head, ucred);
+static struct kauth_cred_entry_head
+ kauth_cred_table_anchor[KAUTH_CRED_TABLE_SIZE];
-static int kauth_cred_add(kauth_cred_t new_cred);
-static void kauth_cred_remove(kauth_cred_t cred);
-static inline u_long kauth_cred_hash(const uint8_t *datap, int data_len, u_long start_key);
-static u_long kauth_cred_get_hashkey(kauth_cred_t cred);
+static struct kauth_cred_entry_head *kauth_cred_get_bucket(kauth_cred_t cred);
+static kauth_cred_t kauth_cred_add(kauth_cred_t new_cred, struct kauth_cred_entry_head *bucket);
+static void kauth_cred_remove_locked(kauth_cred_t cred);
static kauth_cred_t kauth_cred_update(kauth_cred_t old_cred, kauth_cred_t new_cred, boolean_t retain_auditinfo);
-static void kauth_cred_unref_hashlocked(kauth_cred_t *credp);
+static kauth_cred_t kauth_cred_find_and_ref(kauth_cred_t cred,
+ struct kauth_cred_entry_head *bucket);
+static bool kauth_cred_is_equal(kauth_cred_t cred1, kauth_cred_t cred2);
-#if KAUTH_CRED_HASH_DEBUG
-static int kauth_cred_count = 0;
-static void kauth_cred_hash_print(void);
-static void kauth_cred_print(kauth_cred_t cred);
-#endif
+#if CONFIG_EXT_RESOLVER
+
+/*
+ * __KERNEL_IS_WAITING_ON_EXTERNAL_CREDENTIAL_RESOLVER__
+ *
+ * Description: Waits for the user space daemon to respond to the request
+ * we made. Function declared non inline to be visible in
+ * stackshots and spindumps as well as debugging.
+ *
+ * Parameters: workp Work queue entry.
+ *
+ * Returns: 0 on Success.
+ * EIO if Resolver is dead.
+ * EINTR thread interrupted in msleep
+ * EWOULDBLOCK thread timed out in msleep
+ * ERESTART returned by msleep.
+ *
+ */
+static __attribute__((noinline)) int
+__KERNEL_IS_WAITING_ON_EXTERNAL_CREDENTIAL_RESOLVER__(
+ struct kauth_resolver_work *workp)
+{
+ int error = 0;
+ struct timespec ts;
+ for (;;) {
+ /* we could compute a better timeout here */
+ ts.tv_sec = kauth_resolver_timeout;
+ ts.tv_nsec = 0;
+ error = msleep(workp, kauth_resolver_mtx, PCATCH, "kr_submit", &ts);
+ /* request has been completed? */
+ if ((error == 0) && (workp->kr_flags & KAUTH_REQUEST_DONE)) {
+ break;
+ }
+ /* woken because the resolver has died? */
+ if (kauth_resolver_identity == 0) {
+ RESOLVER_FAILED_MESSAGE("kauth external resolver died while while waiting for work to complete");
+ error = KAUTH_RESOLVER_FAILED_ERRCODE;
+ break;
+ }
+ /* an error? */
+ if (error != 0) {
+ break;
+ }
+ }
+ return error;
+}
+
+/*
+ * kauth_resolver_init
+ *
+ * Description: Initialize the daemon side of the credential identity resolver
+ *
+ * Parameters: (void)
+ *
+ * Returns: (void)
+ *
+ * Notes: Initialize the credential identity resolver for use; the
+ * credential identity resolver is the KPI used by the user
+ * space credential identity resolver daemon to communicate
+ * with the kernel via the identitysvc() system call..
+ *
+ * This is how membership in more than 16 groups (1 effective
+ * and 15 supplementary) is supported, and also how UID's,
+ * UUID's, and so on, are translated to/from POSIX credential
+ * values.
+ *
+ * The credential identity resolver operates by attempting to
+ * determine identity first from the credential, then from
+ * the kernel credential identity cache, and finally by
+ * enqueueing a request to a user space daemon.
+ *
+ * This function is called from kauth_init() in the file
+ * kern_authorization.c.
+ */
void
kauth_resolver_init(void)
{
TAILQ_INIT(&kauth_resolver_submitted);
TAILQ_INIT(&kauth_resolver_done);
kauth_resolver_sequence = 31337;
- kauth_resolver_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0/*LCK_ATTR_NULL*/);
+ kauth_resolver_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0 /*LCK_ATTR_NULL*/);
}
+
/*
- * Allocate a work queue entry, submit the work and wait for completion.
+ * kauth_resolver_submit
+ *
+ * Description: Submit an external credential identity resolution request to
+ * the user space daemon.
+ *
+ * Parameters: lkp A pointer to an external
+ * lookup request
+ * extend_data extended data for kr_extend
+ *
+ * Returns: 0 Success
+ * EWOULDBLOCK No resolver registered
+ * EINTR Operation interrupted (e.g. by
+ * a signal)
+ * ENOMEM Could not allocate work item
+ * copyinstr:EFAULT Bad message from user space
+ * workp->kr_result:??? An error from the user space
+ * daemon (includes ENOENT!)
*
- * XXX do we want an 'interruptible' flag vs. always being interruptible?
+ * Implicit returns:
+ * *lkp Modified
+ *
+ * Notes: Allocate a work queue entry, submit the work and wait for
+ * the operation to either complete or time out. Outstanding
+ * operations may also be cancelled.
+ *
+ * Submission is by means of placing the item on a work queue
+ * which is serviced by an external resolver thread calling
+ * into the kernel. The caller then sleeps until timeout,
+ * cancellation, or an external resolver thread calls in with
+ * a result message to kauth_resolver_complete(). All of these
+ * events wake the caller back up.
+ *
+ * This code is called from either kauth_cred_ismember_gid()
+ * for a group membership request, or it is called from
+ * kauth_cred_cache_lookup() when we get a cache miss.
*/
static int
-kauth_resolver_submit(struct kauth_identity_extlookup *lkp)
+kauth_resolver_submit(struct kauth_identity_extlookup *lkp, uint64_t extend_data)
{
struct kauth_resolver_work *workp, *killp;
struct timespec ts;
- int error, shouldfree;
-
+ int error, shouldfree;
+
/* no point actually blocking if the resolver isn't up yet */
if (kauth_resolver_identity == 0) {
/*
- * We've already waited an initial 30 seconds with no result.
+ * We've already waited an initial <kauth_resolver_timeout>
+ * seconds with no result.
+ *
* Sleep on a stack address so no one wakes us before timeout;
* we sleep a half a second in case we are a high priority
* process, so that memberd doesn't starve while we are in a
* tight loop between user and kernel, eating all the CPU.
*/
- error = tsleep(&ts, PZERO | PCATCH, "kr_submit", hz/2);
+ error = tsleep(&ts, PZERO | PCATCH, "kr_submit", hz / 2);
if (kauth_resolver_identity == 0) {
/*
* if things haven't changed while we were asleep,
* tell the caller we couldn't get an authoritative
* answer.
*/
- return(EWOULDBLOCK);
+ return EWOULDBLOCK;
}
}
-
+
MALLOC(workp, struct kauth_resolver_work *, sizeof(*workp), M_KAUTH, M_WAITOK);
- if (workp == NULL)
- return(ENOMEM);
+ if (workp == NULL) {
+ return ENOMEM;
+ }
workp->kr_work = *lkp;
+ workp->kr_extend = extend_data;
workp->kr_refs = 1;
workp->kr_flags = KAUTH_REQUEST_UNSUBMITTED;
workp->kr_result = 0;
/*
- * We insert the request onto the unsubmitted queue, the call in from the
- * resolver will it to the submitted thread when appropriate.
+ * We insert the request onto the unsubmitted queue, the call in from
+ * the resolver will it to the submitted thread when appropriate.
*/
KAUTH_RESOLVER_LOCK();
workp->kr_seqno = workp->kr_work.el_seqno = kauth_resolver_sequence++;
workp->kr_work.el_result = KAUTH_EXTLOOKUP_INPROG;
- /* XXX as an optimisation, we could check the queue for identical items and coalesce */
+ /*
+ * XXX We *MUST NOT* attempt to coalesce identical work items due to
+ * XXX the inability to ensure order of update of the request item
+ * XXX extended data vs. the wakeup; instead, we let whoever is waiting
+ * XXX for each item repeat the update when they wake up.
+ */
TAILQ_INSERT_TAIL(&kauth_resolver_unsubmitted, workp, kr_link);
+ /*
+ * Wake up an external resolver thread to deal with the new work; one
+ * may not be available, and if not, then the request will be grabbed
+ * when a resolver thread comes back into the kernel to request new
+ * work.
+ */
wakeup_one((caddr_t)&kauth_resolver_unsubmitted);
- for (;;) {
- /* we could compute a better timeout here */
- ts.tv_sec = 30;
- ts.tv_nsec = 0;
- error = msleep(workp, kauth_resolver_mtx, PCATCH, "kr_submit", &ts);
- /* request has been completed? */
- if ((error == 0) && (workp->kr_flags & KAUTH_REQUEST_DONE))
- break;
- /* woken because the resolver has died? */
- if (kauth_resolver_identity == 0) {
- error = EIO;
- break;
- }
- /* an error? */
- if (error != 0)
- break;
- }
+ error = __KERNEL_IS_WAITING_ON_EXTERNAL_CREDENTIAL_RESOLVER__(workp);
+
/* if the request was processed, copy the result */
- if (error == 0)
+ if (error == 0) {
*lkp = workp->kr_work;
-
+ }
+
+ if (error == EWOULDBLOCK) {
+ if ((kauth_resolver_timeout_cnt++ % KAUTH_COMPLAINT_INTERVAL) == 0) {
+ printf("kauth external resolver timed out (%d timeout(s) of %d seconds).\n",
+ kauth_resolver_timeout_cnt, kauth_resolver_timeout);
+ }
+
+ if (workp->kr_flags & KAUTH_REQUEST_UNSUBMITTED) {
+ /*
+ * If the request timed out and was never collected, the resolver
+ * is dead and probably not coming back anytime soon. In this
+ * case we revert to no-resolver behaviour, and punt all the other
+ * sleeping requests to clear the backlog.
+ */
+ KAUTH_DEBUG("RESOLVER - request timed out without being collected for processing, resolver dead");
+
+ /*
+ * Make the current resolver non-authoritative, and mark it as
+ * no longer registered to prevent kauth_cred_ismember_gid()
+ * enqueueing more work until a new one is registered. This
+ * mitigates the damage a crashing resolver may inflict.
+ */
+ kauth_resolver_identity = 0;
+ kauth_resolver_registered = 0;
+
+ /* kill all the other requestes that are waiting as well */
+ TAILQ_FOREACH(killp, &kauth_resolver_submitted, kr_link)
+ wakeup(killp);
+ TAILQ_FOREACH(killp, &kauth_resolver_unsubmitted, kr_link)
+ wakeup(killp);
+ /* Cause all waiting-for-work threads to return EIO */
+ wakeup((caddr_t)&kauth_resolver_unsubmitted);
+ }
+ }
+
/*
- * If the request timed out and was never collected, the resolver is dead and
- * probably not coming back anytime soon. In this case we revert to no-resolver
- * behaviour, and punt all the other sleeping requests to clear the backlog.
+ * drop our reference on the work item, and note whether we should
+ * free it or not
*/
- if ((error == EWOULDBLOCK) && (workp->kr_flags & KAUTH_REQUEST_UNSUBMITTED)) {
- KAUTH_DEBUG("RESOLVER - request timed out without being collected for processing, resolver dead");
- kauth_resolver_identity = 0;
- /* kill all the other requestes that are waiting as well */
- TAILQ_FOREACH(killp, &kauth_resolver_submitted, kr_link)
- wakeup(killp);
- TAILQ_FOREACH(killp, &kauth_resolver_unsubmitted, kr_link)
- wakeup(killp);
- }
-
- /* drop our reference on the work item, and note whether we should free it or not */
if (--workp->kr_refs <= 0) {
/* work out which list we have to remove it from */
if (workp->kr_flags & KAUTH_REQUEST_DONE) {
/* someone else still has a reference on this request */
shouldfree = 0;
}
+
/* collect request result */
- if (error == 0)
+ if (error == 0) {
error = workp->kr_result;
+ }
KAUTH_RESOLVER_UNLOCK();
+
/*
* If we dropped the last reference, free the request.
*/
- if (shouldfree)
+ if (shouldfree) {
FREE(workp, M_KAUTH);
+ }
KAUTH_DEBUG("RESOLVER - returning %d", error);
- return(error);
+ return error;
}
+
/*
- * System call interface for the external identity resolver.
+ * identitysvc
+ *
+ * Description: System call interface for the external identity resolver.
+ *
+ * Parameters: uap->message Message from daemon to kernel
+ *
+ * Returns: 0 Successfully became resolver
+ * EPERM Not the resolver process
+ * kauth_authorize_generic:EPERM Not root user
+ * kauth_resolver_complete:EIO
+ * kauth_resolver_complete:EFAULT
+ * kauth_resolver_getwork:EINTR
+ * kauth_resolver_getwork:EFAULT
+ *
+ * Notes: This system call blocks until there is work enqueued, at
+ * which time the kernel wakes it up, and a message from the
+ * kernel is copied out to the identity resolution daemon, which
+ * proceed to attempt to resolve it. When the resolution has
+ * completed (successfully or not), the daemon called back into
+ * this system call to give the result to the kernel, and wait
+ * for the next request.
*/
int
-identitysvc(__unused struct proc *p, struct identitysvc_args *uap, __unused register_t *retval)
+identitysvc(__unused struct proc *p, struct identitysvc_args *uap, __unused int32_t *retval)
{
int opcode = uap->opcode;
user_addr_t message = uap->message;
struct kauth_resolver_work *workp;
+ struct kauth_cache_sizes sz_arg = {};
int error;
pid_t new_id;
+ if (!IOTaskHasEntitlement(current_task(), IDENTITYSVC_ENTITLEMENT)) {
+ KAUTH_DEBUG("RESOLVER - pid %d not entitled to call identitysvc", current_proc()->p_pid);
+ return EPERM;
+ }
+
/*
* New server registering itself.
*/
new_id = current_proc()->p_pid;
if ((error = kauth_authorize_generic(kauth_cred_get(), KAUTH_GENERIC_ISSUSER)) != 0) {
KAUTH_DEBUG("RESOLVER - pid %d refused permission to become identity resolver", new_id);
- return(error);
+ return error;
}
KAUTH_RESOLVER_LOCK();
if (kauth_resolver_identity != new_id) {
workp->kr_flags |= KAUTH_REQUEST_UNSUBMITTED;
TAILQ_INSERT_HEAD(&kauth_resolver_unsubmitted, workp, kr_link);
}
+ /*
+ * Allow user space resolver to override the
+ * external resolution timeout
+ */
+ if (message > 30 && message < 10000) {
+ kauth_resolver_timeout = message;
+ KAUTH_DEBUG("RESOLVER - new resolver changes timeout to %d seconds\n", (int)message);
+ }
kauth_resolver_identity = new_id;
kauth_resolver_registered = 1;
+ kauth_identitysvc_has_registered = 1;
wakeup(&kauth_resolver_unsubmitted);
}
KAUTH_RESOLVER_UNLOCK();
- return(0);
+ return 0;
}
/*
- * Beyond this point, we must be the resolver process.
+ * Beyond this point, we must be the resolver process. We verify this
+ * by confirming the resolver credential and pid.
*/
- if (current_proc()->p_pid != kauth_resolver_identity) {
+ if ((kauth_cred_getuid(kauth_cred_get()) != 0) || (current_proc()->p_pid != kauth_resolver_identity)) {
KAUTH_DEBUG("RESOLVER - call from bogus resolver %d\n", current_proc()->p_pid);
- return(EPERM);
+ return EPERM;
+ }
+
+ if (opcode == KAUTH_GET_CACHE_SIZES) {
+ KAUTH_IDENTITY_LOCK();
+ sz_arg.kcs_id_size = kauth_identity_cachemax;
+ KAUTH_IDENTITY_UNLOCK();
+
+ KAUTH_GROUPS_LOCK();
+ sz_arg.kcs_group_size = kauth_groups_cachemax;
+ KAUTH_GROUPS_UNLOCK();
+
+ if ((error = copyout(&sz_arg, uap->message, sizeof(sz_arg))) != 0) {
+ return error;
+ }
+
+ return 0;
+ } else if (opcode == KAUTH_SET_CACHE_SIZES) {
+ if ((error = copyin(uap->message, &sz_arg, sizeof(sz_arg))) != 0) {
+ return error;
+ }
+
+ if ((sz_arg.kcs_group_size > KAUTH_CACHES_MAX_SIZE) ||
+ (sz_arg.kcs_id_size > KAUTH_CACHES_MAX_SIZE)) {
+ return EINVAL;
+ }
+
+ KAUTH_IDENTITY_LOCK();
+ kauth_identity_cachemax = sz_arg.kcs_id_size;
+ kauth_identity_trimcache(kauth_identity_cachemax);
+ KAUTH_IDENTITY_UNLOCK();
+
+ KAUTH_GROUPS_LOCK();
+ kauth_groups_cachemax = sz_arg.kcs_group_size;
+ kauth_groups_trimcache(kauth_groups_cachemax);
+ KAUTH_GROUPS_UNLOCK();
+
+ return 0;
+ } else if (opcode == KAUTH_CLEAR_CACHES) {
+ KAUTH_IDENTITY_LOCK();
+ kauth_identity_trimcache(0);
+ KAUTH_IDENTITY_UNLOCK();
+
+ KAUTH_GROUPS_LOCK();
+ kauth_groups_trimcache(0);
+ KAUTH_GROUPS_UNLOCK();
+ } else if (opcode == KAUTH_EXTLOOKUP_DEREGISTER) {
+ /*
+ * Terminate outstanding requests; without an authoritative
+ * resolver, we are now back on our own authority.
+ */
+ struct kauth_resolver_work *killp;
+
+ KAUTH_RESOLVER_LOCK();
+
+ /*
+ * Clear the identity, but also mark it as unregistered so
+ * there is no explicit future expectation of us getting a
+ * new resolver any time soon.
+ */
+ kauth_resolver_identity = 0;
+ kauth_resolver_registered = 0;
+
+ TAILQ_FOREACH(killp, &kauth_resolver_submitted, kr_link)
+ wakeup(killp);
+ TAILQ_FOREACH(killp, &kauth_resolver_unsubmitted, kr_link)
+ wakeup(killp);
+ /* Cause all waiting-for-work threads to return EIO */
+ wakeup((caddr_t)&kauth_resolver_unsubmitted);
+ KAUTH_RESOLVER_UNLOCK();
}
-
+
/*
* Got a result returning?
*/
if (opcode & KAUTH_EXTLOOKUP_RESULT) {
- if ((error = kauth_resolver_complete(message)) != 0)
- return(error);
+ if ((error = kauth_resolver_complete(message)) != 0) {
+ return error;
+ }
}
/*
* Caller wants to take more work?
*/
if (opcode & KAUTH_EXTLOOKUP_WORKER) {
- if ((error = kauth_resolver_getwork(message)) != 0)
- return(error);
+ if ((error = kauth_resolver_getwork(message)) != 0) {
+ return error;
+ }
}
- return(0);
+ return 0;
}
+
/*
- * Get work for a caller.
+ * kauth_resolver_getwork_continue
+ *
+ * Description: Continuation for kauth_resolver_getwork
+ *
+ * Parameters: result Error code or 0 for the sleep
+ * that got us to this function
+ *
+ * Returns: 0 Success
+ * EINTR Interrupted (e.g. by signal)
+ * kauth_resolver_getwork2:EFAULT
+ *
+ * Notes: See kauth_resolver_getwork(0 and kauth_resolver_getwork2() for
+ * more information.
*/
static int
-kauth_resolver_getwork(user_addr_t message)
+kauth_resolver_getwork_continue(int result)
+{
+ thread_t thread;
+ struct uthread *ut;
+ user_addr_t message;
+
+ if (result) {
+ KAUTH_RESOLVER_UNLOCK();
+ return result;
+ }
+
+ /*
+ * If we lost a race with another thread/memberd restarting, then we
+ * need to go back to sleep to look for more work. If it was memberd
+ * restarting, then the msleep0() will error out here, as our thread
+ * will already be "dead".
+ */
+ if (TAILQ_FIRST(&kauth_resolver_unsubmitted) == NULL) {
+ int error;
+
+ error = msleep0(&kauth_resolver_unsubmitted, kauth_resolver_mtx, PCATCH, "GRGetWork", 0, kauth_resolver_getwork_continue);
+ /*
+ * If this is a wakeup from another thread in the resolver
+ * deregistering it, error out the request-for-work thread
+ */
+ if (!kauth_resolver_identity) {
+ RESOLVER_FAILED_MESSAGE("external resolver died");
+ error = KAUTH_RESOLVER_FAILED_ERRCODE;
+ }
+ KAUTH_RESOLVER_UNLOCK();
+ return error;
+ }
+
+ thread = current_thread();
+ ut = get_bsdthread_info(thread);
+ message = ut->uu_save.uus_kauth.message;
+ return kauth_resolver_getwork2(message);
+}
+
+
+/*
+ * kauth_resolver_getwork2
+ *
+ * Decription: Common utility function to copy out a identity resolver work
+ * item from the kernel to user space as part of the user space
+ * identity resolver requesting work.
+ *
+ * Parameters: message message to user space
+ *
+ * Returns: 0 Success
+ * EFAULT Bad user space message address
+ *
+ * Notes: This common function exists to permit the use of continuations
+ * in the identity resolution process. This frees up the stack
+ * while we are waiting for the user space resolver to complete
+ * a request. This is specifically used so that our per thread
+ * cost can be small, and we will therefore be willing to run a
+ * larger number of threads in the user space identity resolver.
+ */
+static int
+kauth_resolver_getwork2(user_addr_t message)
{
struct kauth_resolver_work *workp;
- int error;
+ int error;
- KAUTH_RESOLVER_LOCK();
- error = 0;
- while ((workp = TAILQ_FIRST(&kauth_resolver_unsubmitted)) == NULL) {
- error = msleep(&kauth_resolver_unsubmitted, kauth_resolver_mtx, PCATCH, "GRGetWork", 0);
- if (error != 0)
- break;
+ /*
+ * Note: We depend on the caller protecting us from a NULL work item
+ * queue, since we must have the kauth resolver lock on entry to this
+ * function.
+ */
+ workp = TAILQ_FIRST(&kauth_resolver_unsubmitted);
+
+ /*
+ * Copy out the external lookup structure for the request, not
+ * including the el_extend field, which contains the address of the
+ * external buffer provided by the external resolver into which we
+ * copy the extension request information.
+ */
+ /* BEFORE FIELD */
+ if ((error = copyout(&workp->kr_work, message, offsetof(struct kauth_identity_extlookup, el_extend))) != 0) {
+ KAUTH_DEBUG("RESOLVER - error submitting work to resolve");
+ goto out;
+ }
+ /* AFTER FIELD */
+ if ((error = copyout(&workp->kr_work.el_info_reserved_1,
+ message + offsetof(struct kauth_identity_extlookup, el_info_reserved_1),
+ sizeof(struct kauth_identity_extlookup) - offsetof(struct kauth_identity_extlookup, el_info_reserved_1))) != 0) {
+ KAUTH_DEBUG("RESOLVER - error submitting work to resolve");
+ goto out;
}
- if (workp != NULL) {
- if ((error = copyout(&workp->kr_work, message, sizeof(workp->kr_work))) != 0) {
+
+ /*
+ * Handle extended requests here; if we have a request of a type where
+ * the kernel wants a translation of extended information, then we need
+ * to copy it out into the extended buffer, assuming the buffer is
+ * valid; we only attempt to get the buffer address if we have request
+ * data to copy into it.
+ */
+
+ /*
+ * translate a user@domain string into a uid/gid/whatever
+ */
+ if (workp->kr_work.el_flags & (KAUTH_EXTLOOKUP_VALID_PWNAM | KAUTH_EXTLOOKUP_VALID_GRNAM)) {
+ uint64_t uaddr;
+
+ error = copyin(message + offsetof(struct kauth_identity_extlookup, el_extend), &uaddr, sizeof(uaddr));
+ if (!error) {
+ size_t actual; /* not used */
+ /*
+ * Use copyoutstr() to reduce the copy size; we let
+ * this catch a NULL uaddr because we shouldn't be
+ * asking in that case anyway.
+ */
+ error = copyoutstr(CAST_DOWN(void *, workp->kr_extend), uaddr, MAXPATHLEN, &actual);
+ }
+ if (error) {
KAUTH_DEBUG("RESOLVER - error submitting work to resolve");
goto out;
}
- TAILQ_REMOVE(&kauth_resolver_unsubmitted, workp, kr_link);
- workp->kr_flags &= ~KAUTH_REQUEST_UNSUBMITTED;
- workp->kr_flags |= KAUTH_REQUEST_SUBMITTED;
- TAILQ_INSERT_TAIL(&kauth_resolver_submitted, workp, kr_link);
}
+ TAILQ_REMOVE(&kauth_resolver_unsubmitted, workp, kr_link);
+ workp->kr_flags &= ~KAUTH_REQUEST_UNSUBMITTED;
+ workp->kr_flags |= KAUTH_REQUEST_SUBMITTED;
+ TAILQ_INSERT_TAIL(&kauth_resolver_submitted, workp, kr_link);
out:
KAUTH_RESOLVER_UNLOCK();
- return(error);
+ return error;
}
+
/*
- * Return a result from userspace.
+ * kauth_resolver_getwork
+ *
+ * Description: Get a work item from the enqueued requests from the kernel and
+ * give it to the user space daemon.
+ *
+ * Parameters: message message to user space
+ *
+ * Returns: 0 Success
+ * EINTR Interrupted (e.g. by signal)
+ * kauth_resolver_getwork2:EFAULT
+ *
+ * Notes: This function blocks in a continuation if there are no work
+ * items available for processing at the time the user space
+ * identity resolution daemon makes a request for work. This
+ * permits a large number of threads to be used by the daemon,
+ * without using a lot of wired kernel memory when there are no
+ * actual request outstanding.
*/
static int
-kauth_resolver_complete(user_addr_t message)
+kauth_resolver_getwork(user_addr_t message)
{
- struct kauth_identity_extlookup extl;
struct kauth_resolver_work *workp;
- int error, result;
-
- if ((error = copyin(message, &extl, sizeof(extl))) != 0) {
- KAUTH_DEBUG("RESOLVER - error getting completed work\n");
- return(error);
- }
+ int error;
KAUTH_RESOLVER_LOCK();
-
error = 0;
- result = 0;
- switch (extl.el_result) {
- case KAUTH_EXTLOOKUP_INPROG:
- {
- static int once = 0;
+ while ((workp = TAILQ_FIRST(&kauth_resolver_unsubmitted)) == NULL) {
+ thread_t thread = current_thread();
+ struct uthread *ut = get_bsdthread_info(thread);
- /* XXX this should go away once memberd is updated */
- if (!once) {
+ ut->uu_save.uus_kauth.message = message;
+ error = msleep0(&kauth_resolver_unsubmitted, kauth_resolver_mtx, PCATCH, "GRGetWork", 0, kauth_resolver_getwork_continue);
+ KAUTH_RESOLVER_UNLOCK();
+ /*
+ * If this is a wakeup from another thread in the resolver
+ * deregistering it, error out the request-for-work thread
+ */
+ if (!kauth_resolver_identity) {
+ printf("external resolver died");
+ error = KAUTH_RESOLVER_FAILED_ERRCODE;
+ }
+ return error;
+ }
+ return kauth_resolver_getwork2(message);
+}
+
+
+/*
+ * kauth_resolver_complete
+ *
+ * Description: Return a result from userspace.
+ *
+ * Parameters: message message from user space
+ *
+ * Returns: 0 Success
+ * EIO The resolver is dead
+ * copyin:EFAULT Bad message from user space
+ */
+static int
+kauth_resolver_complete(user_addr_t message)
+{
+ struct kauth_identity_extlookup extl;
+ struct kauth_resolver_work *workp;
+ struct kauth_resolver_work *killp;
+ int error, result, want_extend_data;
+
+ /*
+ * Copy in the mesage, including the extension field, since we are
+ * copying into a local variable.
+ */
+ if ((error = copyin(message, &extl, sizeof(extl))) != 0) {
+ KAUTH_DEBUG("RESOLVER - error getting completed work\n");
+ return error;
+ }
+
+ KAUTH_RESOLVER_LOCK();
+
+ error = 0;
+ result = 0;
+ switch (extl.el_result) {
+ case KAUTH_EXTLOOKUP_INPROG:
+ {
+ static int once = 0;
+
+ /* XXX this should go away once memberd is updated */
+ if (!once) {
printf("kauth_resolver: memberd is not setting valid result codes (assuming always successful)\n");
once = 1;
}
}
/* FALLTHROUGH */
+
case KAUTH_EXTLOOKUP_SUCCESS:
break;
case KAUTH_EXTLOOKUP_FATAL:
/* fatal error means the resolver is dead */
KAUTH_DEBUG("RESOLVER - resolver %d died, waiting for a new one", kauth_resolver_identity);
+ RESOLVER_FAILED_MESSAGE("resolver %d died, waiting for a new one", kauth_resolver_identity);
+ /*
+ * Terminate outstanding requests; without an authoritative
+ * resolver, we are now back on our own authority. Tag the
+ * resolver unregistered to prevent kauth_cred_ismember_gid()
+ * enqueueing more work until a new one is registered. This
+ * mitigates the damage a crashing resolver may inflict.
+ */
kauth_resolver_identity = 0;
- /* XXX should we terminate all outstanding requests? */
- error = EIO;
+ kauth_resolver_registered = 0;
+
+ TAILQ_FOREACH(killp, &kauth_resolver_submitted, kr_link)
+ wakeup(killp);
+ TAILQ_FOREACH(killp, &kauth_resolver_unsubmitted, kr_link)
+ wakeup(killp);
+ /* Cause all waiting-for-work threads to return EIO */
+ wakeup((caddr_t)&kauth_resolver_unsubmitted);
+ /* and return EIO to the caller */
+ error = KAUTH_RESOLVER_FAILED_ERRCODE;
break;
+
case KAUTH_EXTLOOKUP_BADRQ:
KAUTH_DEBUG("RESOLVER - resolver reported invalid request %d", extl.el_seqno);
result = EINVAL;
break;
+
case KAUTH_EXTLOOKUP_FAILURE:
KAUTH_DEBUG("RESOLVER - resolver reported transient failure for request %d", extl.el_seqno);
- result = EIO;
+ RESOLVER_FAILED_MESSAGE("resolver reported transient failure for request %d", extl.el_seqno);
+ result = KAUTH_RESOLVER_FAILED_ERRCODE;
break;
+
default:
KAUTH_DEBUG("RESOLVER - resolver returned unexpected status %d", extl.el_result);
- result = EIO;
+ RESOLVER_FAILED_MESSAGE("resolver returned unexpected status %d", extl.el_result);
+ result = KAUTH_RESOLVER_FAILED_ERRCODE;
break;
}
/*
- * In the case of a fatal error, we assume that the resolver will restart
- * quickly and re-collect all of the outstanding requests. Thus, we don't
- * complete the request which returned the fatal error status.
+ * In the case of a fatal error, we assume that the resolver will
+ * restart quickly and re-collect all of the outstanding requests.
+ * Thus, we don't complete the request which returned the fatal
+ * error status.
*/
if (extl.el_result != KAUTH_EXTLOOKUP_FATAL) {
/* scan our list for this request */
TAILQ_FOREACH(workp, &kauth_resolver_submitted, kr_link) {
/* found it? */
if (workp->kr_seqno == extl.el_seqno) {
- /* copy result */
- workp->kr_work = extl;
- /* move onto completed list and wake up requester(s) */
+ /*
+ * Do we want extend_data?
+ */
+ want_extend_data = (workp->kr_work.el_flags & (KAUTH_EXTLOOKUP_WANT_PWNAM | KAUTH_EXTLOOKUP_WANT_GRNAM));
+
+ /*
+ * Get the request of the submitted queue so
+ * that it is not cleaned up out from under
+ * us by a timeout.
+ */
TAILQ_REMOVE(&kauth_resolver_submitted, workp, kr_link);
workp->kr_flags &= ~KAUTH_REQUEST_SUBMITTED;
workp->kr_flags |= KAUTH_REQUEST_DONE;
workp->kr_result = result;
+
+ /* Copy the result message to the work item. */
+ memcpy(&workp->kr_work, &extl, sizeof(struct kauth_identity_extlookup));
+
+ /*
+ * Check if we have a result in the extension
+ * field; if we do, then we need to separately
+ * copy the data from the message el_extend
+ * into the request buffer that's in the work
+ * item. We have to do it here because we do
+ * not want to wake up the waiter until the
+ * data is in their buffer, and because the
+ * actual request response may be destroyed
+ * by the time the requester wakes up, and they
+ * do not have access to the user space buffer
+ * address.
+ *
+ * It is safe to drop and reacquire the lock
+ * here because we've already removed the item
+ * from the submission queue, but have not yet
+ * moved it to the completion queue. Note that
+ * near simultaneous requests may result in
+ * duplication of requests for items in this
+ * window. This should not be a performance
+ * issue and is easily detectable by comparing
+ * time to live on last response vs. time of
+ * next request in the resolver logs.
+ *
+ * A malicious/faulty resolver could overwrite
+ * part of a user's address space if they return
+ * flags that mismatch the original request's flags.
+ */
+ if (want_extend_data && (extl.el_flags & (KAUTH_EXTLOOKUP_VALID_PWNAM | KAUTH_EXTLOOKUP_VALID_GRNAM))) {
+ size_t actual; /* notused */
+
+ KAUTH_RESOLVER_UNLOCK();
+ error = copyinstr(extl.el_extend, CAST_DOWN(void *, workp->kr_extend), MAXPATHLEN, &actual);
+ KAUTH_DEBUG("RESOLVER - resolver got name :%*s: len = %d\n", (int)actual,
+ actual ? "null" : (char *)extl.el_extend, actual);
+ KAUTH_RESOLVER_LOCK();
+ } else if (extl.el_flags & (KAUTH_EXTLOOKUP_VALID_PWNAM | KAUTH_EXTLOOKUP_VALID_GRNAM)) {
+ error = EFAULT;
+ KAUTH_DEBUG("RESOLVER - resolver returned mismatching extension flags (%d), request contained (%d)",
+ extl.el_flags, want_extend_data);
+ }
+
+ /*
+ * Move the completed work item to the
+ * completion queue and wake up requester(s)
+ */
TAILQ_INSERT_TAIL(&kauth_resolver_done, workp, kr_link);
wakeup(workp);
break;
* timed out the work record will be gone.
*/
KAUTH_RESOLVER_UNLOCK();
-
- return(error);
+
+ return error;
}
+#endif /* CONFIG_EXT_RESOLVER */
/*
* Identity cache.
*/
-struct kauth_identity {
- TAILQ_ENTRY(kauth_identity) ki_link;
- int ki_valid;
-#define KI_VALID_UID (1<<0) /* UID and GID are mutually exclusive */
-#define KI_VALID_GID (1<<1)
-#define KI_VALID_GUID (1<<2)
-#define KI_VALID_NTSID (1<<3)
- uid_t ki_uid;
- gid_t ki_gid;
- guid_t ki_guid;
- ntsid_t ki_ntsid;
- /*
- * Expiry times are the earliest time at which we will disregard the cached state and go to
- * userland. Before then if the valid bit is set, we will return the cached value. If it's
- * not set, we will not go to userland to resolve, just assume that there is no answer
- * available.
- */
- time_t ki_guid_expiry;
- time_t ki_ntsid_expiry;
-};
-
-static TAILQ_HEAD(kauth_identity_head, kauth_identity) kauth_identities;
-#define KAUTH_IDENTITY_CACHEMAX 100 /* XXX sizing? */
-static int kauth_identity_count;
-
-static lck_mtx_t *kauth_identity_mtx;
-#define KAUTH_IDENTITY_LOCK() lck_mtx_lock(kauth_identity_mtx);
-#define KAUTH_IDENTITY_UNLOCK() lck_mtx_unlock(kauth_identity_mtx);
-
-
-static struct kauth_identity *kauth_identity_alloc(uid_t uid, gid_t gid, guid_t *guidp, time_t guid_expiry,
- ntsid_t *ntsidp, time_t ntsid_expiry);
-static void kauth_identity_register(struct kauth_identity *kip);
-static void kauth_identity_updatecache(struct kauth_identity_extlookup *elp, struct kauth_identity *kip);
-static void kauth_identity_lru(struct kauth_identity *kip);
-static int kauth_identity_guid_expired(struct kauth_identity *kip);
-static int kauth_identity_ntsid_expired(struct kauth_identity *kip);
-static int kauth_identity_find_uid(uid_t uid, struct kauth_identity *kir);
-static int kauth_identity_find_gid(gid_t gid, struct kauth_identity *kir);
-static int kauth_identity_find_guid(guid_t *guidp, struct kauth_identity *kir);
-static int kauth_identity_find_ntsid(ntsid_t *ntsid, struct kauth_identity *kir);
+#define KI_VALID_UID (1<<0) /* UID and GID are mutually exclusive */
+#define KI_VALID_GID (1<<1)
+#define KI_VALID_GUID (1<<2)
+#define KI_VALID_NTSID (1<<3)
+#define KI_VALID_PWNAM (1<<4) /* Used for translation */
+#define KI_VALID_GRNAM (1<<5) /* Used for translation */
+#define KI_VALID_GROUPS (1<<6)
+#if CONFIG_EXT_RESOLVER
+/*
+ * kauth_identity_init
+ *
+ * Description: Initialize the kernel side of the credential identity resolver
+ *
+ * Parameters: (void)
+ *
+ * Returns: (void)
+ *
+ * Notes: Initialize the credential identity resolver for use; the
+ * credential identity resolver is the KPI used to communicate
+ * with a user space credential identity resolver daemon.
+ *
+ * This function is called from kauth_init() in the file
+ * kern_authorization.c.
+ */
void
kauth_identity_init(void)
{
TAILQ_INIT(&kauth_identities);
- kauth_identity_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0/*LCK_ATTR_NULL*/);
+ kauth_identity_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0 /*LCK_ATTR_NULL*/);
}
-static int
-kauth_identity_resolve(__unused struct kauth_identity_extlookup *el)
-{
- return(kauth_resolver_submit(el));
-}
+/*
+ * kauth_identity_alloc
+ *
+ * Description: Allocate and fill out a kauth_identity structure for
+ * translation between {UID|GID}/GUID/NTSID
+ *
+ * Parameters: uid
+ *
+ * Returns: NULL Insufficient memory to satisfy
+ * the request or bad parameters
+ * !NULL A pointer to the allocated
+ * structure, filled in
+ *
+ * Notes: It is illegal to translate between UID and GID; any given UUID
+ * or NTSID can only refer to an NTSID or UUID (respectively),
+ * and *either* a UID *or* a GID, but not both.
+ */
static struct kauth_identity *
-kauth_identity_alloc(uid_t uid, gid_t gid, guid_t *guidp, time_t guid_expiry, ntsid_t *ntsidp, time_t ntsid_expiry)
+kauth_identity_alloc(uid_t uid, gid_t gid, guid_t *guidp, time_t guid_expiry,
+ ntsid_t *ntsidp, time_t ntsid_expiry, int supgrpcnt, gid_t *supgrps, time_t groups_expiry,
+ const char *name, int nametype)
{
struct kauth_identity *kip;
-
+
/* get and fill in a new identity */
MALLOC(kip, struct kauth_identity *, sizeof(*kip), M_KAUTH, M_WAITOK | M_ZERO);
if (kip != NULL) {
kip->ki_valid = KI_VALID_GID;
}
if (uid != KAUTH_UID_NONE) {
- if (kip->ki_valid & KI_VALID_GID)
+ if (kip->ki_valid & KI_VALID_GID) {
panic("can't allocate kauth identity with both uid and gid");
+ }
kip->ki_uid = uid;
kip->ki_valid = KI_VALID_UID;
}
+ if (supgrpcnt) {
+ /*
+ * A malicious/faulty resolver could return bad values
+ */
+ assert(supgrpcnt >= 0);
+ assert(supgrpcnt <= NGROUPS);
+ assert(supgrps != NULL);
+
+ if ((supgrpcnt < 0) || (supgrpcnt > NGROUPS) || (supgrps == NULL)) {
+ return NULL;
+ }
+ if (kip->ki_valid & KI_VALID_GID) {
+ panic("can't allocate kauth identity with both gid and supplementary groups");
+ }
+ kip->ki_supgrpcnt = supgrpcnt;
+ memcpy(kip->ki_supgrps, supgrps, sizeof(supgrps[0]) * supgrpcnt);
+ kip->ki_valid |= KI_VALID_GROUPS;
+ }
+ kip->ki_groups_expiry = groups_expiry;
if (guidp != NULL) {
kip->ki_guid = *guidp;
kip->ki_valid |= KI_VALID_GUID;
kip->ki_valid |= KI_VALID_NTSID;
}
kip->ki_ntsid_expiry = ntsid_expiry;
+ if (name != NULL) {
+ kip->ki_name = name;
+ kip->ki_valid |= nametype;
+ }
}
- return(kip);
+ return kip;
}
+
/*
- * Register an association between identity tokens.
+ * kauth_identity_register_and_free
+ *
+ * Description: Register an association between identity tokens. The passed
+ * 'kip' is consumed by this function.
+ *
+ * Parameters: kip Pointer to kauth_identity
+ * structure to register
+ *
+ * Returns: (void)
+ *
+ * Notes: The memory pointer to by 'kip' is assumed to have been
+ * previously allocated via kauth_identity_alloc().
*/
static void
-kauth_identity_register(struct kauth_identity *kip)
+kauth_identity_register_and_free(struct kauth_identity *kip)
{
struct kauth_identity *ip;
/*
- * We search the cache for the UID listed in the incoming association. If we
- * already have an entry, the new information is merged.
+ * We search the cache for the UID listed in the incoming association.
+ * If we already have an entry, the new information is merged.
*/
ip = NULL;
KAUTH_IDENTITY_LOCK();
if (kip->ki_valid & KI_VALID_UID) {
- if (kip->ki_valid & KI_VALID_GID)
+ if (kip->ki_valid & KI_VALID_GID) {
panic("kauth_identity: can't insert record with both UID and GID as key");
+ }
TAILQ_FOREACH(ip, &kauth_identities, ki_link)
- if ((ip->ki_valid & KI_VALID_UID) && (ip->ki_uid == kip->ki_uid))
- break;
+ if ((ip->ki_valid & KI_VALID_UID) && (ip->ki_uid == kip->ki_uid)) {
+ break;
+ }
} else if (kip->ki_valid & KI_VALID_GID) {
TAILQ_FOREACH(ip, &kauth_identities, ki_link)
- if ((ip->ki_valid & KI_VALID_GID) && (ip->ki_gid == kip->ki_gid))
- break;
+ if ((ip->ki_valid & KI_VALID_GID) && (ip->ki_gid == kip->ki_gid)) {
+ break;
+ }
} else {
panic("kauth_identity: can't insert record without UID or GID as key");
}
-
+
if (ip != NULL) {
/* we already have an entry, merge/overwrite */
if (kip->ki_valid & KI_VALID_GUID) {
ip->ki_valid |= KI_VALID_NTSID;
}
ip->ki_ntsid_expiry = kip->ki_ntsid_expiry;
- /* and discard the incoming identity */
- FREE(kip, M_KAUTH);
- ip = NULL;
+ /* a valid ki_name field overwrites the previous name field */
+ if (kip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM)) {
+ /* if there's an old one, discard it */
+ const char *oname = NULL;
+ if (ip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM)) {
+ oname = ip->ki_name;
+ }
+ ip->ki_name = kip->ki_name;
+ kip->ki_name = oname;
+ }
+ /* and discard the incoming entry */
+ ip = kip;
} else {
- /* don't have any information on this identity, so just add it */
+ /*
+ * if we don't have any information on this identity, add it;
+ * if it pushes us over our limit, discard the oldest one.
+ */
TAILQ_INSERT_HEAD(&kauth_identities, kip, ki_link);
- if (++kauth_identity_count > KAUTH_IDENTITY_CACHEMAX) {
+ if (++kauth_identity_count > kauth_identity_cachemax) {
ip = TAILQ_LAST(&kauth_identities, kauth_identity_head);
TAILQ_REMOVE(&kauth_identities, ip, ki_link);
kauth_identity_count--;
}
}
KAUTH_IDENTITY_UNLOCK();
- /* have to drop lock before freeing expired entry */
- if (ip != NULL)
+ /* have to drop lock before freeing expired entry (it may be in use) */
+ if (ip != NULL) {
+ /* if the ki_name field is used, clear it first */
+ if (ip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM)) {
+ vfs_removename(ip->ki_name);
+ }
+ /* free the expired entry */
FREE(ip, M_KAUTH);
+ }
}
+
/*
- * Given a lookup result, add any associations that we don't
- * currently have.
+ * kauth_identity_updatecache
+ *
+ * Description: Given a lookup result, add any associations that we don't
+ * currently have; replace ones which have changed.
+ *
+ * Parameters: elp External lookup result from
+ * user space daemon to kernel
+ * rkip pointer to returned kauth
+ * identity, or NULL
+ * extend_data Extended data (can vary)
+ *
+ * Returns: (void)
+ *
+ * Implicit returns:
+ * *rkip Modified (if non-NULL)
+ *
+ * Notes: For extended information requests, this code relies on the fact
+ * that elp->el_flags is never used as an rvalue, and is only
+ * ever bit-tested for valid lookup information we are willing
+ * to cache.
+ *
+ * XXX: We may have to do the same in the case that extended data was
+ * passed out to user space to ensure that the request string
+ * gets cached; we may also be able to use the rkip as an
+ * input to avoid this. The jury is still out.
+ *
+ * XXX: This codes performance could be improved for multiple valid
+ * results by combining the loop iteration in a single loop.
*/
static void
-kauth_identity_updatecache(struct kauth_identity_extlookup *elp, struct kauth_identity *rkip)
+kauth_identity_updatecache(struct kauth_identity_extlookup *elp, struct kauth_identity *rkip, uint64_t extend_data)
{
struct timeval tv;
struct kauth_identity *kip;
+ const char *speculative_name = NULL;
microuptime(&tv);
-
+
+ /*
+ * If there is extended data, and that data represents a name rather
+ * than something else, speculatively create an entry for it in the
+ * string cache. We do this to avoid holding the KAUTH_IDENTITY_LOCK
+ * over the allocation later.
+ */
+ if (elp->el_flags & (KAUTH_EXTLOOKUP_VALID_PWNAM | KAUTH_EXTLOOKUP_VALID_GRNAM)) {
+ const char *tmp = CAST_DOWN(const char *, extend_data);
+ speculative_name = vfs_addname(tmp, strnlen(tmp, MAXPATHLEN - 1), 0, 0);
+ }
+
/* user identity? */
if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_UID) {
KAUTH_IDENTITY_LOCK();
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
/* matching record */
if ((kip->ki_valid & KI_VALID_UID) && (kip->ki_uid == elp->el_uid)) {
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_SUPGRPS) {
+ assert(elp->el_sup_grp_cnt <= NGROUPS);
+ if (elp->el_sup_grp_cnt > NGROUPS) {
+ KAUTH_DEBUG("CACHE - invalid sup_grp_cnt provided (%d), truncating to %d",
+ elp->el_sup_grp_cnt, NGROUPS);
+ elp->el_sup_grp_cnt = NGROUPS;
+ }
+ kip->ki_supgrpcnt = elp->el_sup_grp_cnt;
+ memcpy(kip->ki_supgrps, elp->el_sup_groups, sizeof(elp->el_sup_groups[0]) * kip->ki_supgrpcnt);
+ kip->ki_valid |= KI_VALID_GROUPS;
+ kip->ki_groups_expiry = (elp->el_member_valid) ? tv.tv_sec + elp->el_member_valid : 0;
+ }
if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_UGUID) {
kip->ki_guid = elp->el_uguid;
kip->ki_valid |= KI_VALID_GUID;
}
- kip->ki_guid_expiry = tv.tv_sec + elp->el_uguid_valid;
+ kip->ki_guid_expiry = (elp->el_uguid_valid) ? tv.tv_sec + elp->el_uguid_valid : 0;
if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_USID) {
kip->ki_ntsid = elp->el_usid;
kip->ki_valid |= KI_VALID_NTSID;
}
- kip->ki_ntsid_expiry = tv.tv_sec + elp->el_usid_valid;
+ kip->ki_ntsid_expiry = (elp->el_usid_valid) ? tv.tv_sec + elp->el_usid_valid : 0;
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_PWNAM) {
+ const char *oname = kip->ki_name;
+ kip->ki_name = speculative_name;
+ speculative_name = NULL;
+ kip->ki_valid |= KI_VALID_PWNAM;
+ if (oname) {
+ /*
+ * free oname (if any) outside
+ * the lock
+ */
+ speculative_name = oname;
+ }
+ }
kauth_identity_lru(kip);
- if (rkip != NULL)
+ if (rkip != NULL) {
*rkip = *kip;
+ }
KAUTH_DEBUG("CACHE - refreshed %d is " K_UUID_FMT, kip->ki_uid, K_UUID_ARG(kip->ki_guid));
break;
}
if (kip == NULL) {
kip = kauth_identity_alloc(elp->el_uid, KAUTH_GID_NONE,
(elp->el_flags & KAUTH_EXTLOOKUP_VALID_UGUID) ? &elp->el_uguid : NULL,
- tv.tv_sec + elp->el_uguid_valid,
+ (elp->el_uguid_valid) ? tv.tv_sec + elp->el_uguid_valid : 0,
(elp->el_flags & KAUTH_EXTLOOKUP_VALID_USID) ? &elp->el_usid : NULL,
- tv.tv_sec + elp->el_usid_valid);
+ (elp->el_usid_valid) ? tv.tv_sec + elp->el_usid_valid : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_SUPGRPS) ? elp->el_sup_grp_cnt : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_SUPGRPS) ? elp->el_sup_groups : NULL,
+ (elp->el_member_valid) ? tv.tv_sec + elp->el_member_valid : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_PWNAM) ? speculative_name : NULL,
+ KI_VALID_PWNAM);
if (kip != NULL) {
- if (rkip != NULL)
+ if (rkip != NULL) {
*rkip = *kip;
+ }
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_PWNAM) {
+ speculative_name = NULL;
+ }
KAUTH_DEBUG("CACHE - learned %d is " K_UUID_FMT, kip->ki_uid, K_UUID_ARG(kip->ki_guid));
- kauth_identity_register(kip);
+ kauth_identity_register_and_free(kip);
}
}
}
- /* group identity? */
- if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GID) {
+ /* group identity? (ignore, if we already processed it as a user) */
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GID && !(elp->el_flags & KAUTH_EXTLOOKUP_VALID_UID)) {
KAUTH_IDENTITY_LOCK();
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
/* matching record */
kip->ki_guid = elp->el_gguid;
kip->ki_valid |= KI_VALID_GUID;
}
- kip->ki_guid_expiry = tv.tv_sec + elp->el_gguid_valid;
+ kip->ki_guid_expiry = (elp->el_gguid_valid) ? tv.tv_sec + elp->el_gguid_valid : 0;
if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GSID) {
kip->ki_ntsid = elp->el_gsid;
kip->ki_valid |= KI_VALID_NTSID;
}
- kip->ki_ntsid_expiry = tv.tv_sec + elp->el_gsid_valid;
+ kip->ki_ntsid_expiry = (elp->el_gsid_valid) ? tv.tv_sec + elp->el_gsid_valid : 0;
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GRNAM) {
+ const char *oname = kip->ki_name;
+ kip->ki_name = speculative_name;
+ speculative_name = NULL;
+ kip->ki_valid |= KI_VALID_GRNAM;
+ if (oname) {
+ /*
+ * free oname (if any) outside
+ * the lock
+ */
+ speculative_name = oname;
+ }
+ }
kauth_identity_lru(kip);
- if (rkip != NULL)
+ if (rkip != NULL) {
*rkip = *kip;
+ }
KAUTH_DEBUG("CACHE - refreshed %d is " K_UUID_FMT, kip->ki_uid, K_UUID_ARG(kip->ki_guid));
break;
}
if (kip == NULL) {
kip = kauth_identity_alloc(KAUTH_UID_NONE, elp->el_gid,
(elp->el_flags & KAUTH_EXTLOOKUP_VALID_GGUID) ? &elp->el_gguid : NULL,
- tv.tv_sec + elp->el_gguid_valid,
+ (elp->el_gguid_valid) ? tv.tv_sec + elp->el_gguid_valid : 0,
(elp->el_flags & KAUTH_EXTLOOKUP_VALID_GSID) ? &elp->el_gsid : NULL,
- tv.tv_sec + elp->el_gsid_valid);
+ (elp->el_gsid_valid) ? tv.tv_sec + elp->el_gsid_valid : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_SUPGRPS) ? elp->el_sup_grp_cnt : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_SUPGRPS) ? elp->el_sup_groups : NULL,
+ (elp->el_member_valid) ? tv.tv_sec + elp->el_member_valid : 0,
+ (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GRNAM) ? speculative_name : NULL,
+ KI_VALID_GRNAM);
if (kip != NULL) {
- if (rkip != NULL)
+ if (rkip != NULL) {
*rkip = *kip;
+ }
+ if (elp->el_flags & KAUTH_EXTLOOKUP_VALID_GRNAM) {
+ speculative_name = NULL;
+ }
KAUTH_DEBUG("CACHE - learned %d is " K_UUID_FMT, kip->ki_uid, K_UUID_ARG(kip->ki_guid));
- kauth_identity_register(kip);
+ kauth_identity_register_and_free(kip);
}
}
}
+ /* If we have a name reference to drop, drop it here */
+ if (speculative_name != NULL) {
+ vfs_removename(speculative_name);
+ }
+}
+
+
+/*
+ * Trim older entries from the identity cache.
+ *
+ * Must be called with the identity cache lock held.
+ */
+static void
+kauth_identity_trimcache(int newsize)
+{
+ struct kauth_identity *kip;
+
+ lck_mtx_assert(kauth_identity_mtx, LCK_MTX_ASSERT_OWNED);
+
+ while (kauth_identity_count > newsize) {
+ kip = TAILQ_LAST(&kauth_identities, kauth_identity_head);
+ TAILQ_REMOVE(&kauth_identities, kip, ki_link);
+ kauth_identity_count--;
+ FREE(kip, M_KAUTH);
+ }
}
/*
- * Promote the entry to the head of the LRU, assumes the cache is locked.
+ * kauth_identity_lru
+ *
+ * Description: Promote the entry to the head of the LRU, assumes the cache
+ * is locked.
+ *
+ * Parameters: kip kauth identity to move to the
+ * head of the LRU list, if it's
+ * not already there
+ *
+ * Returns: (void)
*
- * This is called even if the entry has expired; typically an expired entry
- * that's been looked up is about to be revalidated, and having it closer to
- * the head of the LRU means finding it quickly again when the revalidation
- * comes through.
+ * Notes: This is called even if the entry has expired; typically an
+ * expired entry that's been looked up is about to be revalidated,
+ * and having it closer to the head of the LRU means finding it
+ * quickly again when the revalidation comes through.
*/
static void
kauth_identity_lru(struct kauth_identity *kip)
}
}
+
/*
- * Handly lazy expiration of translations.
+ * kauth_identity_guid_expired
+ *
+ * Description: Handle lazy expiration of GUID translations.
+ *
+ * Parameters: kip kauth identity to check for
+ * GUID expiration
+ *
+ * Returns: 1 Expired
+ * 0 Not expired
*/
static int
kauth_identity_guid_expired(struct kauth_identity *kip)
{
struct timeval tv;
+ /*
+ * Expiration time of 0 means this entry is persistent.
+ */
+ if (kip->ki_guid_expiry == 0) {
+ return 0;
+ }
+
microuptime(&tv);
- KAUTH_DEBUG("CACHE - GUID expires @ %d now %d", kip->ki_guid_expiry, tv.tv_sec);
- return((kip->ki_guid_expiry <= tv.tv_sec) ? 1 : 0);
+ KAUTH_DEBUG("CACHE - GUID expires @ %ld now %ld", kip->ki_guid_expiry, tv.tv_sec);
+
+ return (kip->ki_guid_expiry <= tv.tv_sec) ? 1 : 0;
}
+
+/*
+ * kauth_identity_ntsid_expired
+ *
+ * Description: Handle lazy expiration of NTSID translations.
+ *
+ * Parameters: kip kauth identity to check for
+ * NTSID expiration
+ *
+ * Returns: 1 Expired
+ * 0 Not expired
+ */
static int
kauth_identity_ntsid_expired(struct kauth_identity *kip)
{
struct timeval tv;
+ /*
+ * Expiration time of 0 means this entry is persistent.
+ */
+ if (kip->ki_ntsid_expiry == 0) {
+ return 0;
+ }
+
+ microuptime(&tv);
+ KAUTH_DEBUG("CACHE - NTSID expires @ %ld now %ld", kip->ki_ntsid_expiry, tv.tv_sec);
+
+ return (kip->ki_ntsid_expiry <= tv.tv_sec) ? 1 : 0;
+}
+
+/*
+ * kauth_identity_groups_expired
+ *
+ * Description: Handle lazy expiration of supplemental group translations.
+ *
+ * Parameters: kip kauth identity to check for
+ * groups expiration
+ *
+ * Returns: 1 Expired
+ * 0 Not expired
+ */
+static int
+kauth_identity_groups_expired(struct kauth_identity *kip)
+{
+ struct timeval tv;
+
+ /*
+ * Expiration time of 0 means this entry is persistent.
+ */
+ if (kip->ki_groups_expiry == 0) {
+ return 0;
+ }
+
microuptime(&tv);
- KAUTH_DEBUG("CACHE - NTSID expires @ %d now %d", kip->ki_ntsid_expiry, tv.tv_sec);
- return((kip->ki_ntsid_expiry <= tv.tv_sec) ? 1 : 0);
+ KAUTH_DEBUG("CACHE - GROUPS expires @ %ld now %ld\n", kip->ki_groups_expiry, tv.tv_sec);
+
+ return (kip->ki_groups_expiry <= tv.tv_sec) ? 1 : 0;
}
/*
- * Search for an entry by UID. Returns a copy of the entry, ENOENT if no valid
- * association exists for the UID.
+ * kauth_identity_find_uid
+ *
+ * Description: Search for an entry by UID
+ *
+ * Parameters: uid UID to find
+ * kir Pointer to return area
+ * getname Name buffer, if ki_name wanted
+ *
+ * Returns: 0 Found
+ * ENOENT Not found
+ *
+ * Implicit returns:
+ * *klr Modified, if found
*/
static int
-kauth_identity_find_uid(uid_t uid, struct kauth_identity *kir)
+kauth_identity_find_uid(uid_t uid, struct kauth_identity *kir, char *getname)
{
struct kauth_identity *kip;
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
if ((kip->ki_valid & KI_VALID_UID) && (uid == kip->ki_uid)) {
kauth_identity_lru(kip);
+ /* Copy via structure assignment */
*kir = *kip;
+ /* If a name is wanted and one exists, copy it out */
+ if (getname != NULL && (kip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM))) {
+ strlcpy(getname, kip->ki_name, MAXPATHLEN);
+ }
break;
}
}
KAUTH_IDENTITY_UNLOCK();
- return((kip == NULL) ? ENOENT : 0);
+ return (kip == NULL) ? ENOENT : 0;
}
/*
- * Search for an entry by GID. Returns a copy of the entry, ENOENT if no valid
- * association exists for the GID.
+ * kauth_identity_find_gid
+ *
+ * Description: Search for an entry by GID
+ *
+ * Parameters: gid GID to find
+ * kir Pointer to return area
+ * getname Name buffer, if ki_name wanted
+ *
+ * Returns: 0 Found
+ * ENOENT Not found
+ *
+ * Implicit returns:
+ * *klr Modified, if found
*/
static int
-kauth_identity_find_gid(uid_t gid, struct kauth_identity *kir)
+kauth_identity_find_gid(uid_t gid, struct kauth_identity *kir, char *getname)
{
struct kauth_identity *kip;
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
if ((kip->ki_valid & KI_VALID_GID) && (gid == kip->ki_gid)) {
kauth_identity_lru(kip);
+ /* Copy via structure assignment */
*kir = *kip;
+ /* If a name is wanted and one exists, copy it out */
+ if (getname != NULL && (kip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM))) {
+ strlcpy(getname, kip->ki_name, MAXPATHLEN);
+ }
break;
}
}
KAUTH_IDENTITY_UNLOCK();
- return((kip == NULL) ? ENOENT : 0);
+ return (kip == NULL) ? ENOENT : 0;
}
/*
- * Search for an entry by GUID. Returns a copy of the entry, ENOENT if no valid
- * association exists for the GUID. Note that the association may be expired,
- * in which case the caller may elect to call out to userland to revalidate.
+ * kauth_identity_find_guid
+ *
+ * Description: Search for an entry by GUID
+ *
+ * Parameters: guidp Pointer to GUID to find
+ * kir Pointer to return area
+ * getname Name buffer, if ki_name wanted
+ *
+ * Returns: 0 Found
+ * ENOENT Not found
+ *
+ * Implicit returns:
+ * *klr Modified, if found
+ *
+ * Note: The association may be expired, in which case the caller
+ * may elect to call out to userland to revalidate.
*/
static int
-kauth_identity_find_guid(guid_t *guidp, struct kauth_identity *kir)
+kauth_identity_find_guid(guid_t *guidp, struct kauth_identity *kir, char *getname)
{
struct kauth_identity *kip;
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
if ((kip->ki_valid & KI_VALID_GUID) && (kauth_guid_equal(guidp, &kip->ki_guid))) {
kauth_identity_lru(kip);
+ /* Copy via structure assignment */
+ *kir = *kip;
+ /* If a name is wanted and one exists, copy it out */
+ if (getname != NULL && (kip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM))) {
+ strlcpy(getname, kip->ki_name, MAXPATHLEN);
+ }
+ break;
+ }
+ }
+ KAUTH_IDENTITY_UNLOCK();
+ return (kip == NULL) ? ENOENT : 0;
+}
+
+/*
+ * kauth_identity_find_nam
+ *
+ * Description: Search for an entry by name
+ *
+ * Parameters: name Pointer to name to find
+ * valid KI_VALID_PWNAM or KI_VALID_GRNAM
+ * kir Pointer to return area
+ *
+ * Returns: 0 Found
+ * ENOENT Not found
+ *
+ * Implicit returns:
+ * *klr Modified, if found
+ */
+static int
+kauth_identity_find_nam(char *name, int valid, struct kauth_identity *kir)
+{
+ struct kauth_identity *kip;
+
+ KAUTH_IDENTITY_LOCK();
+ TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
+ if ((kip->ki_valid & valid) && !strcmp(name, kip->ki_name)) {
+ kauth_identity_lru(kip);
+ /* Copy via structure assignment */
*kir = *kip;
break;
}
}
KAUTH_IDENTITY_UNLOCK();
- return((kip == NULL) ? ENOENT : 0);
+ return (kip == NULL) ? ENOENT : 0;
}
+
/*
- * Search for an entry by NT Security ID. Returns a copy of the entry, ENOENT if no valid
- * association exists for the SID. Note that the association may be expired,
- * in which case the caller may elect to call out to userland to revalidate.
+ * kauth_identity_find_ntsid
+ *
+ * Description: Search for an entry by NTSID
+ *
+ * Parameters: ntsid Pointer to NTSID to find
+ * kir Pointer to return area
+ * getname Name buffer, if ki_name wanted
+ *
+ * Returns: 0 Found
+ * ENOENT Not found
+ *
+ * Implicit returns:
+ * *klr Modified, if found
+ *
+ * Note: The association may be expired, in which case the caller
+ * may elect to call out to userland to revalidate.
*/
static int
-kauth_identity_find_ntsid(ntsid_t *ntsid, struct kauth_identity *kir)
+kauth_identity_find_ntsid(ntsid_t *ntsid, struct kauth_identity *kir, char *getname)
{
struct kauth_identity *kip;
TAILQ_FOREACH(kip, &kauth_identities, ki_link) {
if ((kip->ki_valid & KI_VALID_NTSID) && (kauth_ntsid_equal(ntsid, &kip->ki_ntsid))) {
kauth_identity_lru(kip);
+ /* Copy via structure assignment */
*kir = *kip;
+ /* If a name is wanted and one exists, copy it out */
+ if (getname != NULL && (kip->ki_valid & (KI_VALID_PWNAM | KI_VALID_GRNAM))) {
+ strlcpy(getname, kip->ki_name, MAXPATHLEN);
+ }
break;
}
}
KAUTH_IDENTITY_UNLOCK();
- return((kip == NULL) ? ENOENT : 0);
+ return (kip == NULL) ? ENOENT : 0;
}
+#endif /* CONFIG_EXT_RESOLVER */
+
/*
* GUID handling.
*/
guid_t kauth_null_guid;
+
+/*
+ * kauth_guid_equal
+ *
+ * Description: Determine the equality of two GUIDs
+ *
+ * Parameters: guid1 Pointer to first GUID
+ * guid2 Pointer to second GUID
+ *
+ * Returns: 0 If GUIDs are unequal
+ * !0 If GUIDs are equal
+ */
int
kauth_guid_equal(guid_t *guid1, guid_t *guid2)
{
- return(!bcmp(guid1, guid2, sizeof(*guid1)));
+ return bcmp(guid1, guid2, sizeof(*guid1)) == 0;
}
+
/*
- * Look for well-known GUIDs.
+ * kauth_wellknown_guid
+ *
+ * Description: Determine if a GUID is a well-known GUID
+ *
+ * Parameters: guid Pointer to GUID to check
+ *
+ * Returns: KAUTH_WKG_NOT Not a well known GUID
+ * KAUTH_WKG_EVERYBODY "Everybody"
+ * KAUTH_WKG_NOBODY "Nobody"
+ * KAUTH_WKG_OWNER "Other"
+ * KAUTH_WKG_GROUP "Group"
*/
int
kauth_wellknown_guid(guid_t *guid)
{
- static char fingerprint[] = {0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef};
- int code;
+ static char fingerprint[] = {0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef};
+ uint32_t code;
/*
* All WKGs begin with the same 12 bytes.
*/
- if (!bcmp((void *)guid, fingerprint, 12)) {
+ if (bcmp((void *)guid, fingerprint, 12) == 0) {
/*
- * The final 4 bytes are our code.
+ * The final 4 bytes are our code (in network byte order).
*/
- code = *(u_int32_t *)&guid->g_guid[12];
- switch(code) {
+ code = OSSwapHostToBigInt32(*(uint32_t *)&guid->g_guid[12]);
+ switch (code) {
case 0x0000000c:
- return(KAUTH_WKG_EVERYBODY);
+ return KAUTH_WKG_EVERYBODY;
case 0xfffffffe:
- return(KAUTH_WKG_NOBODY);
+ return KAUTH_WKG_NOBODY;
case 0x0000000a:
- return(KAUTH_WKG_OWNER);
+ return KAUTH_WKG_OWNER;
case 0x00000010:
- return(KAUTH_WKG_GROUP);
+ return KAUTH_WKG_GROUP;
}
}
- return(KAUTH_WKG_NOT);
+ return KAUTH_WKG_NOT;
}
/*
- * NT Security Identifier handling.
+ * kauth_ntsid_equal
+ *
+ * Description: Determine the equality of two NTSIDs (NT Security Identifiers)
+ *
+ * Parameters: sid1 Pointer to first NTSID
+ * sid2 Pointer to second NTSID
+ *
+ * Returns: 0 If GUIDs are unequal
+ * !0 If GUIDs are equal
*/
int
kauth_ntsid_equal(ntsid_t *sid1, ntsid_t *sid2)
/* check sizes for equality, also sanity-check size while we're at it */
if ((KAUTH_NTSID_SIZE(sid1) == KAUTH_NTSID_SIZE(sid2)) &&
(KAUTH_NTSID_SIZE(sid1) <= sizeof(*sid1)) &&
- !bcmp(sid1, sid2, KAUTH_NTSID_SIZE(sid1)))
- return(1);
- return(0);
+ bcmp(sid1, sid2, KAUTH_NTSID_SIZE(sid1)) == 0) {
+ return 1;
+ }
+ return 0;
}
+
/*
* Identity KPI
*
* be done using it.
*/
-static int kauth_cred_cache_lookup(int from, int to, void *src, void *dst);
-/*
- * Fetch UID from credential.
- */
-uid_t
-kauth_cred_getuid(kauth_cred_t cred)
-{
- NULLCRED_CHECK(cred);
- return(cred->cr_uid);
-}
/*
- * Fetch GID from credential.
+ * kauth_cred_change_egid
+ *
+ * Description: Set EGID by changing the first element of cr_groups for the
+ * passed credential; if the new EGID exists in the list of
+ * groups already, then rotate the old EGID into its position,
+ * otherwise replace it
+ *
+ * Parameters: cred Pointer to the credential to modify
+ * new_egid The new EGID to set
+ *
+ * Returns: 0 The egid did not displace a member of
+ * the supplementary group list
+ * 1 The egid being set displaced a member
+ * of the supplementary groups list
+ *
+ * Note: Utility function; internal use only because of locking.
+ *
+ * This function operates on the credential passed; the caller
+ * must operate either on a newly allocated credential (one for
+ * which there is no hash cache reference and no externally
+ * visible pointer reference), or a template credential.
+ */
+static int
+kauth_cred_change_egid(kauth_cred_t cred, gid_t new_egid)
+{
+ int i;
+ int displaced = 1;
+#if radar_4600026
+ int is_member;
+#endif /* radar_4600026 */
+ gid_t old_egid = kauth_cred_getgid(cred);
+ posix_cred_t pcred = posix_cred_get(cred);
+
+ /* Ignoring the first entry, scan for a match for the new egid */
+ for (i = 1; i < pcred->cr_ngroups; i++) {
+ /*
+ * If we find a match, swap them so we don't lose overall
+ * group information
+ */
+ if (pcred->cr_groups[i] == new_egid) {
+ pcred->cr_groups[i] = old_egid;
+ DEBUG_CRED_CHANGE("kauth_cred_change_egid: unset displaced\n");
+ displaced = 0;
+ break;
+ }
+ }
+
+#if radar_4600026
+#error Fix radar 4600026 first!!!
+
+/*
+ * This is correct for memberd behaviour, but incorrect for POSIX; to address
+ * this, we would need to automatically opt-out any SUID/SGID binary, and force
+ * it to use initgroups to opt back in. We take the approach of considering it
+ * opt'ed out in any group of 16 displacement instead, since it's a much more
+ * conservative approach (i.e. less likely to cause things to break).
+ */
+
+ /*
+ * If we displaced a member of the supplementary groups list of the
+ * credential, and we have not opted out of memberd, then if memberd
+ * says that the credential is a member of the group, then it has not
+ * actually been displaced.
+ *
+ * NB: This is typically a cold code path.
+ */
+ if (displaced && !(pcred->cr_flags & CRF_NOMEMBERD) &&
+ kauth_cred_ismember_gid(cred, new_egid, &is_member) == 0 &&
+ is_member) {
+ displaced = 0;
+ DEBUG_CRED_CHANGE("kauth_cred_change_egid: reset displaced\n");
+ }
+#endif /* radar_4600026 */
+
+ /* set the new EGID into the old spot */
+ pcred->cr_groups[0] = new_egid;
+
+ return displaced;
+}
+
+
+/*
+ * kauth_cred_getuid
+ *
+ * Description: Fetch UID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (uid_t) UID associated with credential
+ */
+uid_t
+kauth_cred_getuid(kauth_cred_t cred)
+{
+ NULLCRED_CHECK(cred);
+ return posix_cred_get(cred)->cr_uid;
+}
+
+
+/*
+ * kauth_cred_getruid
+ *
+ * Description: Fetch RUID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (uid_t) RUID associated with credential
+ */
+uid_t
+kauth_cred_getruid(kauth_cred_t cred)
+{
+ NULLCRED_CHECK(cred);
+ return posix_cred_get(cred)->cr_ruid;
+}
+
+
+/*
+ * kauth_cred_getsvuid
+ *
+ * Description: Fetch SVUID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (uid_t) SVUID associated with credential
*/
uid_t
+kauth_cred_getsvuid(kauth_cred_t cred)
+{
+ NULLCRED_CHECK(cred);
+ return posix_cred_get(cred)->cr_svuid;
+}
+
+
+/*
+ * kauth_cred_getgid
+ *
+ * Description: Fetch GID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (gid_t) GID associated with credential
+ */
+gid_t
kauth_cred_getgid(kauth_cred_t cred)
{
NULLCRED_CHECK(cred);
- return(cred->cr_gid);
+ return posix_cred_get(cred)->cr_gid;
+}
+
+
+/*
+ * kauth_cred_getrgid
+ *
+ * Description: Fetch RGID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (gid_t) RGID associated with credential
+ */
+gid_t
+kauth_cred_getrgid(kauth_cred_t cred)
+{
+ NULLCRED_CHECK(cred);
+ return posix_cred_get(cred)->cr_rgid;
+}
+
+
+/*
+ * kauth_cred_getsvgid
+ *
+ * Description: Fetch SVGID from credential
+ *
+ * Parameters: cred Credential to examine
+ *
+ * Returns: (gid_t) SVGID associated with credential
+ */
+gid_t
+kauth_cred_getsvgid(kauth_cred_t cred)
+{
+ NULLCRED_CHECK(cred);
+ return posix_cred_get(cred)->cr_svgid;
+}
+
+
+static int kauth_cred_cache_lookup(int from, int to, void *src, void *dst);
+
+#if CONFIG_EXT_RESOLVER == 0
+/*
+ * If there's no resolver, only support a subset of the kauth_cred_x2y() lookups.
+ */
+static __inline int
+kauth_cred_cache_lookup(int from, int to, void *src, void *dst)
+{
+ /* NB: These must match the definitions used by Libinfo's mbr_identifier_translate(). */
+ static const uuid_t _user_compat_prefix = {0xff, 0xff, 0xee, 0xee, 0xdd, 0xdd, 0xcc, 0xcc, 0xbb, 0xbb, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00};
+ static const uuid_t _group_compat_prefix = {0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0x00, 0x00, 0x00, 0x00};
+#define COMPAT_PREFIX_LEN (sizeof(uuid_t) - sizeof(id_t))
+
+ assert(from != to);
+
+ switch (from) {
+ case KI_VALID_UID: {
+ id_t uid = htonl(*(id_t *)src);
+
+ if (to == KI_VALID_GUID) {
+ uint8_t *uu = dst;
+ memcpy(uu, _user_compat_prefix, sizeof(_user_compat_prefix));
+ memcpy(&uu[COMPAT_PREFIX_LEN], &uid, sizeof(uid));
+ return 0;
+ }
+ break;
+ }
+ case KI_VALID_GID: {
+ id_t gid = htonl(*(id_t *)src);
+
+ if (to == KI_VALID_GUID) {
+ uint8_t *uu = dst;
+ memcpy(uu, _group_compat_prefix, sizeof(_group_compat_prefix));
+ memcpy(&uu[COMPAT_PREFIX_LEN], &gid, sizeof(gid));
+ return 0;
+ }
+ break;
+ }
+ case KI_VALID_GUID: {
+ const uint8_t *uu = src;
+
+ if (to == KI_VALID_UID) {
+ if (memcmp(uu, _user_compat_prefix, COMPAT_PREFIX_LEN) == 0) {
+ id_t uid;
+ memcpy(&uid, &uu[COMPAT_PREFIX_LEN], sizeof(uid));
+ *(id_t *)dst = ntohl(uid);
+ return 0;
+ }
+ } else if (to == KI_VALID_GID) {
+ if (memcmp(uu, _group_compat_prefix, COMPAT_PREFIX_LEN) == 0) {
+ id_t gid;
+ memcpy(&gid, &uu[COMPAT_PREFIX_LEN], sizeof(gid));
+ *(id_t *)dst = ntohl(gid);
+ return 0;
+ }
+ }
+ break;
+ }
+ default:
+ /* NOT IMPLEMENTED */
+ break;
+ }
+ return ENOENT;
+}
+#endif
+
+#if defined(CONFIG_EXT_RESOLVER) && (CONFIG_EXT_RESOLVER)
+/*
+ * Structure to hold supplemental groups. Used for impedance matching with
+ * kauth_cred_cache_lookup below.
+ */
+struct supgroups {
+ int *count;
+ gid_t *groups;
+};
+
+/*
+ * kauth_cred_uid2groups
+ *
+ * Description: Fetch supplemental GROUPS from UID
+ *
+ * Parameters: uid UID to examine
+ * groups pointer to an array of gid_ts
+ * gcount pointer to the number of groups wanted/returned
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *groups Modified, if successful
+ * *gcount Modified, if successful
+ *
+ */
+static int
+kauth_cred_uid2groups(uid_t *uid, gid_t *groups, int *gcount)
+{
+ int rv;
+
+ struct supgroups supgroups;
+ supgroups.count = gcount;
+ supgroups.groups = groups;
+
+ rv = kauth_cred_cache_lookup(KI_VALID_UID, KI_VALID_GROUPS, uid, &supgroups);
+
+ return rv;
+}
+#endif
+
+/*
+ * kauth_cred_guid2pwnam
+ *
+ * Description: Fetch PWNAM from GUID
+ *
+ * Parameters: guidp Pointer to GUID to examine
+ * pwnam Pointer to user@domain buffer
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *pwnam Modified, if successful
+ *
+ * Notes: pwnam is assumed to point to a buffer of MAXPATHLEN in size
+ */
+int
+kauth_cred_guid2pwnam(guid_t *guidp, char *pwnam)
+{
+ return kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_PWNAM, guidp, pwnam);
+}
+
+
+/*
+ * kauth_cred_guid2grnam
+ *
+ * Description: Fetch GRNAM from GUID
+ *
+ * Parameters: guidp Pointer to GUID to examine
+ * grnam Pointer to group@domain buffer
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *grnam Modified, if successful
+ *
+ * Notes: grnam is assumed to point to a buffer of MAXPATHLEN in size
+ */
+int
+kauth_cred_guid2grnam(guid_t *guidp, char *grnam)
+{
+ return kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_GRNAM, guidp, grnam);
+}
+
+
+/*
+ * kauth_cred_pwnam2guid
+ *
+ * Description: Fetch PWNAM from GUID
+ *
+ * Parameters: pwnam String containing user@domain
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
+ *
+ * Notes: pwnam should not point to a request larger than MAXPATHLEN
+ * bytes in size, including the NUL termination of the string.
+ */
+int
+kauth_cred_pwnam2guid(char *pwnam, guid_t *guidp)
+{
+ return kauth_cred_cache_lookup(KI_VALID_PWNAM, KI_VALID_GUID, pwnam, guidp);
+}
+
+
+/*
+ * kauth_cred_grnam2guid
+ *
+ * Description: Fetch GRNAM from GUID
+ *
+ * Parameters: grnam String containing group@domain
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
+ *
+ * Notes: grnam should not point to a request larger than MAXPATHLEN
+ * bytes in size, including the NUL termination of the string.
+ */
+int
+kauth_cred_grnam2guid(char *grnam, guid_t *guidp)
+{
+ return kauth_cred_cache_lookup(KI_VALID_GRNAM, KI_VALID_GUID, grnam, guidp);
}
+
/*
- * Fetch UID from GUID.
+ * kauth_cred_guid2uid
+ *
+ * Description: Fetch UID from GUID
+ *
+ * Parameters: guidp Pointer to GUID to examine
+ * uidp Pointer to buffer for UID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *uidp Modified, if successful
*/
int
kauth_cred_guid2uid(guid_t *guidp, uid_t *uidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_UID, guidp, uidp));
+ return kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_UID, guidp, uidp);
}
+
/*
- * Fetch GID from GUID.
+ * kauth_cred_guid2gid
+ *
+ * Description: Fetch GID from GUID
+ *
+ * Parameters: guidp Pointer to GUID to examine
+ * gidp Pointer to buffer for GID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *gidp Modified, if successful
*/
int
kauth_cred_guid2gid(guid_t *guidp, gid_t *gidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_GID, guidp, gidp));
+ return kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_GID, guidp, gidp);
+}
+
+/*
+ * kauth_cred_nfs4domain2dsnode
+ *
+ * Description: Fetch dsnode from nfs4domain
+ *
+ * Parameters: nfs4domain Pointer to a string nfs4 domain
+ * dsnode Pointer to buffer for dsnode
+ *
+ * Returns: 0 Success
+ * ENOENT For now just a stub that always fails
+ *
+ * Implicit returns:
+ * *dsnode Modified, if successuful
+ */
+int
+kauth_cred_nfs4domain2dsnode(__unused char *nfs4domain, __unused char *dsnode)
+{
+ return ENOENT;
+}
+
+/*
+ * kauth_cred_dsnode2nfs4domain
+ *
+ * Description: Fetch nfs4domain from dsnode
+ *
+ * Parameters: nfs4domain Pointer to string dsnode
+ * dsnode Pointer to buffer for nfs4domain
+ *
+ * Returns: 0 Success
+ * ENOENT For now just a stub that always fails
+ *
+ * Implicit returns:
+ * *nfs4domain Modified, if successuful
+ */
+int
+kauth_cred_dsnode2nfs4domain(__unused char *dsnode, __unused char *nfs4domain)
+{
+ return ENOENT;
}
/*
- * Fetch UID from NT SID.
+ * kauth_cred_ntsid2uid
+ *
+ * Description: Fetch UID from NTSID
+ *
+ * Parameters: sidp Pointer to NTSID to examine
+ * uidp Pointer to buffer for UID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *uidp Modified, if successful
*/
int
kauth_cred_ntsid2uid(ntsid_t *sidp, uid_t *uidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_UID, sidp, uidp));
+ return kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_UID, sidp, uidp);
}
+
/*
- * Fetch GID from NT SID.
+ * kauth_cred_ntsid2gid
+ *
+ * Description: Fetch GID from NTSID
+ *
+ * Parameters: sidp Pointer to NTSID to examine
+ * gidp Pointer to buffer for GID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *gidp Modified, if successful
*/
int
kauth_cred_ntsid2gid(ntsid_t *sidp, gid_t *gidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_GID, sidp, gidp));
+ return kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_GID, sidp, gidp);
}
+
/*
- * Fetch GUID from NT SID.
+ * kauth_cred_ntsid2guid
+ *
+ * Description: Fetch GUID from NTSID
+ *
+ * Parameters: sidp Pointer to NTSID to examine
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
*/
int
kauth_cred_ntsid2guid(ntsid_t *sidp, guid_t *guidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_GUID, sidp, guidp));
+ return kauth_cred_cache_lookup(KI_VALID_NTSID, KI_VALID_GUID, sidp, guidp);
}
+
/*
- * Fetch GUID from UID.
+ * kauth_cred_uid2guid
+ *
+ * Description: Fetch GUID from UID
+ *
+ * Parameters: uid UID to examine
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
*/
int
kauth_cred_uid2guid(uid_t uid, guid_t *guidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_UID, KI_VALID_GUID, &uid, guidp));
+ return kauth_cred_cache_lookup(KI_VALID_UID, KI_VALID_GUID, &uid, guidp);
}
+
/*
- * Fetch user GUID from credential.
+ * kauth_cred_getguid
+ *
+ * Description: Fetch GUID from credential
+ *
+ * Parameters: cred Credential to examine
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
*/
int
kauth_cred_getguid(kauth_cred_t cred, guid_t *guidp)
{
NULLCRED_CHECK(cred);
- return(kauth_cred_uid2guid(kauth_cred_getuid(cred), guidp));
+ return kauth_cred_uid2guid(kauth_cred_getuid(cred), guidp);
}
+
/*
- * Fetch GUID from GID.
+ * kauth_cred_getguid
+ *
+ * Description: Fetch GUID from GID
+ *
+ * Parameters: gid GID to examine
+ * guidp Pointer to buffer for GUID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *guidp Modified, if successful
*/
int
kauth_cred_gid2guid(gid_t gid, guid_t *guidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_GID, KI_VALID_GUID, &gid, guidp));
+ return kauth_cred_cache_lookup(KI_VALID_GID, KI_VALID_GUID, &gid, guidp);
}
+
/*
- * Fetch NT SID from UID.
+ * kauth_cred_uid2ntsid
+ *
+ * Description: Fetch NTSID from UID
+ *
+ * Parameters: uid UID to examine
+ * sidp Pointer to buffer for NTSID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *sidp Modified, if successful
*/
int
kauth_cred_uid2ntsid(uid_t uid, ntsid_t *sidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_UID, KI_VALID_NTSID, &uid, sidp));
+ return kauth_cred_cache_lookup(KI_VALID_UID, KI_VALID_NTSID, &uid, sidp);
}
+
/*
- * Fetch NT SID from credential.
+ * kauth_cred_getntsid
+ *
+ * Description: Fetch NTSID from credential
+ *
+ * Parameters: cred Credential to examine
+ * sidp Pointer to buffer for NTSID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *sidp Modified, if successful
*/
int
kauth_cred_getntsid(kauth_cred_t cred, ntsid_t *sidp)
{
NULLCRED_CHECK(cred);
- return(kauth_cred_uid2ntsid(kauth_cred_getuid(cred), sidp));
+ return kauth_cred_uid2ntsid(kauth_cred_getuid(cred), sidp);
}
+
/*
- * Fetch NT SID from GID.
+ * kauth_cred_gid2ntsid
+ *
+ * Description: Fetch NTSID from GID
+ *
+ * Parameters: gid GID to examine
+ * sidp Pointer to buffer for NTSID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *sidp Modified, if successful
*/
int
kauth_cred_gid2ntsid(gid_t gid, ntsid_t *sidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_GID, KI_VALID_NTSID, &gid, sidp));
+ return kauth_cred_cache_lookup(KI_VALID_GID, KI_VALID_NTSID, &gid, sidp);
}
+
/*
- * Fetch NT SID from GUID.
+ * kauth_cred_guid2ntsid
+ *
+ * Description: Fetch NTSID from GUID
+ *
+ * Parameters: guidp Pointer to GUID to examine
+ * sidp Pointer to buffer for NTSID
+ *
+ * Returns: 0 Success
+ * kauth_cred_cache_lookup:EINVAL
+ *
+ * Implicit returns:
+ * *sidp Modified, if successful
*/
int
kauth_cred_guid2ntsid(guid_t *guidp, ntsid_t *sidp)
{
- return(kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_NTSID, guidp, sidp));
+ return kauth_cred_cache_lookup(KI_VALID_GUID, KI_VALID_NTSID, guidp, sidp);
}
-
/*
- * Lookup a translation in the cache.
+ * kauth_cred_cache_lookup
+ *
+ * Description: Lookup a translation in the cache; if one is not found, and
+ * the attempt was not fatal, submit the request to the resolver
+ * instead, and wait for it to complete or be aborted.
+ *
+ * Parameters: from Identity information we have
+ * to Identity information we want
+ * src Pointer to buffer containing
+ * the source identity
+ * dst Pointer to buffer to receive
+ * the target identity
+ *
+ * Returns: 0 Success
+ * EINVAL Unknown source identity type
*/
+#if CONFIG_EXT_RESOLVER
static int
kauth_cred_cache_lookup(int from, int to, void *src, void *dst)
{
struct kauth_identity ki;
struct kauth_identity_extlookup el;
int error;
+ uint64_t extend_data = 0ULL;
int (* expired)(struct kauth_identity *kip);
+ char *namebuf = NULL;
KAUTH_DEBUG("CACHE - translate %d to %d", from, to);
-
+
/*
* Look for an existing cache entry for this association.
* If the entry has not expired, return the cached information.
+ * We do not cache user@domain translations here; they use too
+ * much memory to hold onto forever, and can not be updated
+ * atomically.
*/
- ki.ki_valid = 0;
- switch(from) {
+ if (to == KI_VALID_PWNAM || to == KI_VALID_GRNAM) {
+ if (dst == NULL) {
+ return EINVAL;
+ }
+ namebuf = dst;
+ *namebuf = '\0';
+ }
+ ki.ki_valid = 0;
+ switch (from) {
case KI_VALID_UID:
- error = kauth_identity_find_uid(*(uid_t *)src, &ki);
+ error = kauth_identity_find_uid(*(uid_t *)src, &ki, namebuf);
break;
case KI_VALID_GID:
- error = kauth_identity_find_gid(*(gid_t *)src, &ki);
+ error = kauth_identity_find_gid(*(gid_t *)src, &ki, namebuf);
break;
case KI_VALID_GUID:
- error = kauth_identity_find_guid((guid_t *)src, &ki);
+ error = kauth_identity_find_guid((guid_t *)src, &ki, namebuf);
break;
case KI_VALID_NTSID:
- error = kauth_identity_find_ntsid((ntsid_t *)src, &ki);
+ error = kauth_identity_find_ntsid((ntsid_t *)src, &ki, namebuf);
+ break;
+ case KI_VALID_PWNAM:
+ case KI_VALID_GRNAM:
+ /* Names are unique in their 'from' space */
+ error = kauth_identity_find_nam((char *)src, from, &ki);
break;
default:
- return(EINVAL);
+ return EINVAL;
+ }
+ /* If we didn't get what we're asking for. Call the resolver */
+ if (!error && !(to & ki.ki_valid)) {
+ error = ENOENT;
}
/* lookup failure or error */
if (error != 0) {
/* any other error is fatal */
if (error != ENOENT) {
+ /* XXX bogus check - this is not possible */
KAUTH_DEBUG("CACHE - cache search error %d", error);
- return(error);
+ return error;
}
} else {
- /* do we have a translation? */
- if (ki.ki_valid & to) {
- /* found a valid cached entry, check expiry */
- switch(to) {
+ /* found a valid cached entry, check expiry */
+ switch (to) {
+ case KI_VALID_GUID:
+ expired = kauth_identity_guid_expired;
+ break;
+ case KI_VALID_NTSID:
+ expired = kauth_identity_ntsid_expired;
+ break;
+ case KI_VALID_GROUPS:
+ expired = kauth_identity_groups_expired;
+ break;
+ default:
+ switch (from) {
case KI_VALID_GUID:
expired = kauth_identity_guid_expired;
break;
expired = kauth_identity_ntsid_expired;
break;
default:
- switch(from) {
- case KI_VALID_GUID:
- expired = kauth_identity_guid_expired;
- break;
- case KI_VALID_NTSID:
- expired = kauth_identity_ntsid_expired;
- break;
- default:
- expired = NULL;
- }
- }
- KAUTH_DEBUG("CACHE - found matching entry with valid %d", ki.ki_valid);
- /*
- * If no expiry function, or not expired, we have found
- * a hit.
- */
- if (!expired) {
- KAUTH_DEBUG("CACHE - no expiry function");
- goto found;
+ expired = NULL;
}
+ }
+
+ /*
+ * If no expiry function, or not expired, we have found
+ * a hit.
+ */
+ if (expired) {
if (!expired(&ki)) {
KAUTH_DEBUG("CACHE - entry valid, unexpired");
+ expired = NULL; /* must clear it is used as a flag */
+ } else {
+ /*
+ * We leave ki_valid set here; it contains a
+ * translation but the TTL has expired. If we can't
+ * get a result from the resolver, we will use it as
+ * a better-than nothing alternative.
+ */
+
+ KAUTH_DEBUG("CACHE - expired entry found");
+ }
+ } else {
+ KAUTH_DEBUG("CACHE - no expiry function");
+ }
+
+ if (!expired) {
+ /* do we have a translation? */
+ if (ki.ki_valid & to) {
+ KAUTH_DEBUG("CACHE - found matching entry with valid 0x%08x", ki.ki_valid);
+ DTRACE_PROC4(kauth__identity__cache__hit, int, from, int, to, void *, src, void *, dst);
goto found;
+ } else {
+ /*
+ * GUIDs and NTSIDs map to either a UID or a GID, but not both.
+ * If we went looking for a translation from GUID or NTSID and
+ * found a translation that wasn't for our desired type, then
+ * don't bother calling the resolver. We know that this
+ * GUID/NTSID can't translate to our desired type.
+ */
+ switch (from) {
+ case KI_VALID_GUID:
+ case KI_VALID_NTSID:
+ switch (to) {
+ case KI_VALID_GID:
+ if ((ki.ki_valid & KI_VALID_UID)) {
+ KAUTH_DEBUG("CACHE - unexpected entry 0x%08x & %x", ki.ki_valid, KI_VALID_GID);
+ return ENOENT;
+ }
+ break;
+ case KI_VALID_UID:
+ if ((ki.ki_valid & KI_VALID_GID)) {
+ KAUTH_DEBUG("CACHE - unexpected entry 0x%08x & %x", ki.ki_valid, KI_VALID_UID);
+ return ENOENT;
+ }
+ break;
+ }
+ break;
+ }
}
- /*
- * We leave ki_valid set here; it contains a translation but the TTL has
- * expired. If we can't get a result from the resolver, we will
- * use it as a better-than nothing alternative.
- */
- KAUTH_DEBUG("CACHE - expired entry found");
}
}
/*
- * Call the resolver. We ask for as much data as we can get.
+ * We failed to find a cache entry; call the resolver.
+ *
+ * Note: We ask for as much non-extended data as we can get,
+ * and only provide (or ask for) extended information if
+ * we have a 'from' (or 'to') which requires it. This
+ * way we don't pay for the extra transfer overhead for
+ * data we don't need.
*/
- switch(from) {
+ bzero(&el, sizeof(el));
+ el.el_info_pid = current_proc()->p_pid;
+ switch (from) {
case KI_VALID_UID:
el.el_flags = KAUTH_EXTLOOKUP_VALID_UID;
el.el_uid = *(uid_t *)src;
el.el_usid = *(ntsid_t *)src;
el.el_gsid = *(ntsid_t *)src;
break;
+ case KI_VALID_PWNAM:
+ /* extra overhead */
+ el.el_flags = KAUTH_EXTLOOKUP_VALID_PWNAM;
+ extend_data = CAST_USER_ADDR_T(src);
+ break;
+ case KI_VALID_GRNAM:
+ /* extra overhead */
+ el.el_flags = KAUTH_EXTLOOKUP_VALID_GRNAM;
+ extend_data = CAST_USER_ADDR_T(src);
+ break;
default:
- return(EINVAL);
+ return EINVAL;
}
/*
* Here we ask for everything all at once, to avoid having to work
el.el_flags |= KAUTH_EXTLOOKUP_WANT_UID | KAUTH_EXTLOOKUP_WANT_GID |
KAUTH_EXTLOOKUP_WANT_UGUID | KAUTH_EXTLOOKUP_WANT_GGUID |
KAUTH_EXTLOOKUP_WANT_USID | KAUTH_EXTLOOKUP_WANT_GSID;
+ if (to == KI_VALID_PWNAM) {
+ /* extra overhead */
+ el.el_flags |= KAUTH_EXTLOOKUP_WANT_PWNAM;
+ extend_data = CAST_USER_ADDR_T(dst);
+ }
+ if (to == KI_VALID_GRNAM) {
+ /* extra overhead */
+ el.el_flags |= KAUTH_EXTLOOKUP_WANT_GRNAM;
+ extend_data = CAST_USER_ADDR_T(dst);
+ }
+ if (to == KI_VALID_GROUPS) {
+ /* Expensive and only useful for an NFS client not using kerberos */
+ el.el_flags |= KAUTH_EXTLOOKUP_WANT_SUPGRPS;
+ if (ki.ki_valid & KI_VALID_GROUPS) {
+ /*
+ * Copy the current supplemental groups for the resolver.
+ * The resolver should check these groups first and if
+ * the user (uid) is still a member it should endeavor to
+ * keep them in the list. Otherwise NFS clients could get
+ * changing access to server file system objects on each
+ * expiration.
+ */
+ if (ki.ki_supgrpcnt > NGROUPS) {
+ panic("kauth data structure corrupted. kauth identity 0x%p with %d groups, greater than max of %d",
+ &ki, ki.ki_supgrpcnt, NGROUPS);
+ }
+
+ el.el_sup_grp_cnt = ki.ki_supgrpcnt;
+
+ memcpy(el.el_sup_groups, ki.ki_supgrps, sizeof(el.el_sup_groups[0]) * ki.ki_supgrpcnt);
+ /* Let the resolver know these were the previous valid groups */
+ el.el_flags |= KAUTH_EXTLOOKUP_VALID_SUPGRPS;
+ KAUTH_DEBUG("GROUPS: Sending previously valid GROUPS");
+ } else {
+ KAUTH_DEBUG("GROUPS: no valid groups to send");
+ }
+ }
+
+ /* Call resolver */
KAUTH_DEBUG("CACHE - calling resolver for %x", el.el_flags);
- error = kauth_identity_resolve(&el);
+
+ DTRACE_PROC3(kauth__id__resolver__submitted, int, from, int, to, uintptr_t, src);
+
+ error = kauth_resolver_submit(&el, extend_data);
+
+ DTRACE_PROC2(kauth__id__resolver__returned, int, error, struct kauth_identity_extlookup *, &el)
+
KAUTH_DEBUG("CACHE - resolver returned %d", error);
- /* was the lookup successful? */
+
+ /* was the external lookup successful? */
if (error == 0) {
/*
- * Save the results from the lookup - may have other information even if we didn't
- * get a guid.
+ * Save the results from the lookup - we may have other
+ * information, even if we didn't get a guid or the
+ * extended data.
+ *
+ * If we came from a name, we know the extend_data is valid.
+ */
+ if (from == KI_VALID_PWNAM) {
+ el.el_flags |= KAUTH_EXTLOOKUP_VALID_PWNAM;
+ } else if (from == KI_VALID_GRNAM) {
+ el.el_flags |= KAUTH_EXTLOOKUP_VALID_GRNAM;
+ }
+
+ kauth_identity_updatecache(&el, &ki, extend_data);
+
+ /*
+ * Check to see if we have a valid cache entry
+ * originating from the result.
*/
- kauth_identity_updatecache(&el, &ki);
+ if (!(ki.ki_valid & to)) {
+ error = ENOENT;
+ }
+ }
+ if (error) {
+ return error;
}
+found:
/*
- * Check to see if we have a valid result.
+ * Copy from the appropriate struct kauth_identity cache entry
+ * structure into the destination buffer area.
*/
- if (!error && !(ki.ki_valid & to))
- error = ENOENT;
- if (error)
- return(error);
-found:
- switch(to) {
+ switch (to) {
case KI_VALID_UID:
*(uid_t *)dst = ki.ki_uid;
break;
case KI_VALID_NTSID:
*(ntsid_t *)dst = ki.ki_ntsid;
break;
+ case KI_VALID_GROUPS: {
+ struct supgroups *gp = (struct supgroups *)dst;
+ u_int32_t limit = ki.ki_supgrpcnt;
+
+ if (gp->count) {
+ limit = MIN(ki.ki_supgrpcnt, *gp->count);
+ *gp->count = limit;
+ }
+
+ memcpy(gp->groups, ki.ki_supgrps, sizeof(gid_t) * limit);
+ }
+ break;
+ case KI_VALID_PWNAM:
+ case KI_VALID_GRNAM:
+ /* handled in kauth_resolver_complete() */
+ break;
default:
- return(EINVAL);
+ return EINVAL;
}
KAUTH_DEBUG("CACHE - returned successfully");
- return(0);
+ return 0;
}
* XXX the linked-list implementation here needs to be optimized.
*/
-struct kauth_group_membership {
- TAILQ_ENTRY(kauth_group_membership) gm_link;
- uid_t gm_uid; /* the identity whose membership we're recording */
- gid_t gm_gid; /* group of which they are a member */
- time_t gm_expiry; /* TTL for the membership */
- int gm_flags;
-#define KAUTH_GROUP_ISMEMBER (1<<0)
-};
-
-TAILQ_HEAD(kauth_groups_head, kauth_group_membership) kauth_groups;
-#define KAUTH_GROUPS_CACHEMAX 100 /* XXX sizing? */
-static int kauth_groups_count;
-
-static lck_mtx_t *kauth_groups_mtx;
-#define KAUTH_GROUPS_LOCK() lck_mtx_lock(kauth_groups_mtx);
-#define KAUTH_GROUPS_UNLOCK() lck_mtx_unlock(kauth_groups_mtx);
-
-static int kauth_groups_expired(struct kauth_group_membership *gm);
-static void kauth_groups_lru(struct kauth_group_membership *gm);
-static void kauth_groups_updatecache(struct kauth_identity_extlookup *el);
-
+/*
+ * kauth_groups_init
+ *
+ * Description: Initialize the groups cache
+ *
+ * Parameters: (void)
+ *
+ * Returns: (void)
+ *
+ * Notes: Initialize the groups cache for use; the group cache is used
+ * to avoid unnecessary calls out to user space.
+ *
+ * This function is called from kauth_init() in the file
+ * kern_authorization.c.
+ */
void
kauth_groups_init(void)
{
TAILQ_INIT(&kauth_groups);
- kauth_groups_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0/*LCK_ATTR_NULL*/);
+ kauth_groups_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0 /*LCK_ATTR_NULL*/);
}
+
+/*
+ * kauth_groups_expired
+ *
+ * Description: Handle lazy expiration of group membership cache entries
+ *
+ * Parameters: gm group membership entry to
+ * check for expiration
+ *
+ * Returns: 1 Expired
+ * 0 Not expired
+ */
static int
kauth_groups_expired(struct kauth_group_membership *gm)
{
struct timeval tv;
+ /*
+ * Expiration time of 0 means this entry is persistent.
+ */
+ if (gm->gm_expiry == 0) {
+ return 0;
+ }
+
microuptime(&tv);
- return((gm->gm_expiry <= tv.tv_sec) ? 1 : 0);
+
+ return (gm->gm_expiry <= tv.tv_sec) ? 1 : 0;
}
+
+/*
+ * kauth_groups_lru
+ *
+ * Description: Promote the entry to the head of the LRU, assumes the cache
+ * is locked.
+ *
+ * Parameters: kip group membership entry to move
+ * to the head of the LRU list,
+ * if it's not already there
+ *
+ * Returns: (void)
+ *
+ * Notes: This is called even if the entry has expired; typically an
+ * expired entry that's been looked up is about to be revalidated,
+ * and having it closer to the head of the LRU means finding it
+ * quickly again when the revalidation comes through.
+ */
static void
kauth_groups_lru(struct kauth_group_membership *gm)
{
}
}
+
+/*
+ * kauth_groups_updatecache
+ *
+ * Description: Given a lookup result, add any group cache associations that
+ * we don't currently have.
+ *
+ * Parameters: elp External lookup result from
+ * user space daemon to kernel
+ * rkip pointer to returned kauth
+ * identity, or NULL
+ *
+ * Returns: (void)
+ */
static void
kauth_groups_updatecache(struct kauth_identity_extlookup *el)
{
struct kauth_group_membership *gm;
struct timeval tv;
-
+
/* need a valid response if we are to cache anything */
if ((el->el_flags &
- (KAUTH_EXTLOOKUP_VALID_UID | KAUTH_EXTLOOKUP_VALID_GID | KAUTH_EXTLOOKUP_VALID_MEMBERSHIP)) !=
- (KAUTH_EXTLOOKUP_VALID_UID | KAUTH_EXTLOOKUP_VALID_GID | KAUTH_EXTLOOKUP_VALID_MEMBERSHIP))
+ (KAUTH_EXTLOOKUP_VALID_UID | KAUTH_EXTLOOKUP_VALID_GID | KAUTH_EXTLOOKUP_VALID_MEMBERSHIP)) !=
+ (KAUTH_EXTLOOKUP_VALID_UID | KAUTH_EXTLOOKUP_VALID_GID | KAUTH_EXTLOOKUP_VALID_MEMBERSHIP)) {
return;
+ }
microuptime(&tv);
- /* search for an existing record for this association before inserting */
+ /*
+ * Search for an existing record for this association before inserting
+ * a new one; if we find one, update it instead of creating a new one
+ */
KAUTH_GROUPS_LOCK();
TAILQ_FOREACH(gm, &kauth_groups, gm_link) {
if ((el->el_uid == gm->gm_uid) &&
} else {
gm->gm_flags &= ~KAUTH_GROUP_ISMEMBER;
}
- gm->gm_expiry = el->el_member_valid + tv.tv_sec;
+ gm->gm_expiry = (el->el_member_valid) ? el->el_member_valid + tv.tv_sec : 0;
kauth_groups_lru(gm);
break;
}
KAUTH_GROUPS_UNLOCK();
/* if we found an entry to update, stop here */
- if (gm != NULL)
+ if (gm != NULL) {
return;
+ }
/* allocate a new record */
MALLOC(gm, struct kauth_group_membership *, sizeof(*gm), M_KAUTH, M_WAITOK);
} else {
gm->gm_flags &= ~KAUTH_GROUP_ISMEMBER;
}
- gm->gm_expiry = el->el_member_valid + tv.tv_sec;
- }
+ gm->gm_expiry = (el->el_member_valid) ? el->el_member_valid + tv.tv_sec : 0;
+ }
/*
- * Insert the new entry. Note that it's possible to race ourselves here
- * and end up with duplicate entries in the list. Wasteful, but harmless
- * since the first into the list will never be looked up, and thus will
- * eventually just fall off the end.
+ * Insert the new entry. Note that it's possible to race ourselves
+ * here and end up with duplicate entries in the list. Wasteful, but
+ * harmless since the first into the list will never be looked up,
+ * and thus will eventually just fall off the end.
*/
KAUTH_GROUPS_LOCK();
TAILQ_INSERT_HEAD(&kauth_groups, gm, gm_link);
- if (kauth_groups_count++ > KAUTH_GROUPS_CACHEMAX) {
+ if (++kauth_groups_count > kauth_groups_cachemax) {
gm = TAILQ_LAST(&kauth_groups, kauth_groups_head);
TAILQ_REMOVE(&kauth_groups, gm, gm_link);
kauth_groups_count--;
KAUTH_GROUPS_UNLOCK();
/* free expired cache entry */
- if (gm != NULL)
+ if (gm != NULL) {
+ FREE(gm, M_KAUTH);
+ }
+}
+
+/*
+ * Trim older entries from the group membership cache.
+ *
+ * Must be called with the group cache lock held.
+ */
+static void
+kauth_groups_trimcache(int new_size)
+{
+ struct kauth_group_membership *gm;
+
+ lck_mtx_assert(kauth_groups_mtx, LCK_MTX_ASSERT_OWNED);
+
+ while (kauth_groups_count > new_size) {
+ gm = TAILQ_LAST(&kauth_groups, kauth_groups_head);
+ TAILQ_REMOVE(&kauth_groups, gm, gm_link);
+ kauth_groups_count--;
FREE(gm, M_KAUTH);
+ }
}
+#endif /* CONFIG_EXT_RESOLVER */
/*
* Group membership KPI
*/
+
/*
- * This function guarantees not to modify resultp when returning an error.
+ * kauth_cred_ismember_gid
+ *
+ * Description: Given a credential and a GID, determine if the GID is a member
+ * of one of the supplementary groups associated with the given
+ * credential
+ *
+ * Parameters: cred Credential to check in
+ * gid GID to check for membership
+ * resultp Pointer to int to contain the
+ * result of the call
+ *
+ * Returns: 0 Success
+ * ENOENT Could not perform lookup
+ * kauth_resolver_submit:EWOULDBLOCK
+ * kauth_resolver_submit:EINTR
+ * kauth_resolver_submit:ENOMEM
+ * kauth_resolver_submit:ENOENT User space daemon did not vend
+ * this credential.
+ * kauth_resolver_submit:??? Unlikely error from user space
+ *
+ * Implicit returns:
+ * *resultp (modified) 1 Is member
+ * 0 Is not member
+ *
+ * Notes: This function guarantees not to modify resultp when returning
+ * an error.
+ *
+ * This function effectively checks the EGID as well, since the
+ * EGID is cr_groups[0] as an implementation detail.
*/
int
kauth_cred_ismember_gid(kauth_cred_t cred, gid_t gid, int *resultp)
{
- struct kauth_group_membership *gm;
- struct kauth_identity_extlookup el;
- int i, error;
+ posix_cred_t pcred = posix_cred_get(cred);
+ int i;
/*
* Check the per-credential list of override groups.
* We can conditionalise this on cred->cr_gmuid == KAUTH_UID_NONE since
* the cache should be used for that case.
*/
- for (i = 0; i < cred->cr_ngroups; i++) {
- if (gid == cred->cr_groups[i]) {
+ for (i = 0; i < pcred->cr_ngroups; i++) {
+ if (gid == pcred->cr_groups[i]) {
*resultp = 1;
- return(0);
+ return 0;
}
}
* If we don't have a UID for group membership checks, the in-cred list
* was authoritative and we can stop here.
*/
- if (cred->cr_gmuid == KAUTH_UID_NONE) {
+ if (pcred->cr_gmuid == KAUTH_UID_NONE) {
*resultp = 0;
- return(0);
+ return 0;
}
-
-
+
+#if CONFIG_EXT_RESOLVER
+ struct kauth_group_membership *gm;
+ struct kauth_identity_extlookup el;
+ int error;
+
/*
- * If the resolver hasn't checked in yet, we are early in the boot phase and
- * the local group list is complete and authoritative.
+ * If the resolver hasn't checked in yet, we are early in the boot
+ * phase and the local group list is complete and authoritative.
*/
if (!kauth_resolver_registered) {
*resultp = 0;
- return(0);
+ return 0;
}
-
+
/* TODO: */
/* XXX check supplementary groups */
/* XXX check whiteout groups */
*/
KAUTH_GROUPS_LOCK();
TAILQ_FOREACH(gm, &kauth_groups, gm_link) {
- if ((gm->gm_uid == cred->cr_gmuid) && (gm->gm_gid == gid) && !kauth_groups_expired(gm)) {
+ if ((gm->gm_uid == pcred->cr_gmuid) && (gm->gm_gid == gid) && !kauth_groups_expired(gm)) {
kauth_groups_lru(gm);
break;
}
}
/* did we find a membership entry? */
- if (gm != NULL)
+ if (gm != NULL) {
*resultp = (gm->gm_flags & KAUTH_GROUP_ISMEMBER) ? 1 : 0;
+ }
KAUTH_GROUPS_UNLOCK();
/* if we did, we can return now */
- if (gm != NULL)
- return(0);
-
+ if (gm != NULL) {
+ DTRACE_PROC2(kauth__group__cache__hit, int, pcred->cr_gmuid, int, gid);
+ return 0;
+ }
+
/* nothing in the cache, need to go to userland */
+ bzero(&el, sizeof(el));
+ el.el_info_pid = current_proc()->p_pid;
el.el_flags = KAUTH_EXTLOOKUP_VALID_UID | KAUTH_EXTLOOKUP_VALID_GID | KAUTH_EXTLOOKUP_WANT_MEMBERSHIP;
- el.el_uid = cred->cr_gmuid;
+ el.el_uid = pcred->cr_gmuid;
el.el_gid = gid;
- error = kauth_identity_resolve(&el);
- if (error != 0)
- return(error);
+ el.el_member_valid = 0; /* XXX set by resolver? */
+
+ DTRACE_PROC2(kauth__group__resolver__submitted, int, el.el_uid, int, el.el_gid);
+
+ error = kauth_resolver_submit(&el, 0ULL);
+
+ DTRACE_PROC2(kauth__group__resolver__returned, int, error, int, el.el_flags);
+
+ if (error != 0) {
+ return error;
+ }
/* save the results from the lookup */
kauth_groups_updatecache(&el);
/* if we successfully ascertained membership, report */
if (el.el_flags & KAUTH_EXTLOOKUP_VALID_MEMBERSHIP) {
*resultp = (el.el_flags & KAUTH_EXTLOOKUP_ISMEMBER) ? 1 : 0;
- return(0);
+ return 0;
}
- return(ENOENT);
+ return ENOENT;
+#else
+ *resultp = 0;
+ return 0;
+#endif
}
/*
- * Determine whether the supplied credential is a member of the
- * group nominated by GUID.
+ * kauth_cred_ismember_guid
+ *
+ * Description: Determine whether the supplied credential is a member of the
+ * group nominated by GUID.
+ *
+ * Parameters: cred Credential to check in
+ * guidp Pointer to GUID whose group
+ * we are testing for membership
+ * resultp Pointer to int to contain the
+ * result of the call
+ *
+ * Returns: 0 Success
+ * kauth_cred_guid2gid:EINVAL
+ * kauth_cred_ismember_gid:ENOENT
+ * kauth_resolver_submit:ENOENT User space daemon did not vend
+ * this credential.
+ * kauth_cred_ismember_gid:EWOULDBLOCK
+ * kauth_cred_ismember_gid:EINTR
+ * kauth_cred_ismember_gid:ENOMEM
+ * kauth_cred_ismember_gid:??? Unlikely error from user space
+ *
+ * Implicit returns:
+ * *resultp (modified) 1 Is member
+ * 0 Is not member
*/
int
-kauth_cred_ismember_guid(kauth_cred_t cred, guid_t *guidp, int *resultp)
+kauth_cred_ismember_guid(__unused kauth_cred_t cred, guid_t *guidp, int *resultp)
{
- gid_t gid;
- int error, wkg;
+ int error = 0;
- error = 0;
- wkg = kauth_wellknown_guid(guidp);
- switch(wkg) {
+ switch (kauth_wellknown_guid(guidp)) {
case KAUTH_WKG_NOBODY:
*resultp = 0;
break;
*resultp = 1;
break;
default:
- /* translate guid to gid */
+ {
+ gid_t gid;
+#if CONFIG_EXT_RESOLVER
+ struct kauth_identity ki;
+
+ /*
+ * Grovel the identity cache looking for this GUID.
+ * If we find it, and it is for a user record, return
+ * false because it's not a group.
+ *
+ * This is necessary because we don't have -ve caching
+ * of group memberships, and we really want to avoid
+ * calling out to the resolver if at all possible.
+ *
+ * Because we're called by the ACL evaluator, and the
+ * ACL evaluator is likely to encounter ACEs for users,
+ * this is expected to be a common case.
+ */
+ ki.ki_valid = 0;
+ if ((error = kauth_identity_find_guid(guidp, &ki, NULL)) == 0 &&
+ !kauth_identity_guid_expired(&ki)) {
+ if (ki.ki_valid & KI_VALID_GID) {
+ /* It's a group after all... */
+ gid = ki.ki_gid;
+ goto do_check;
+ }
+ if (ki.ki_valid & KI_VALID_UID) {
+ *resultp = 0;
+ return 0;
+ }
+ }
+#endif /* CONFIG_EXT_RESOLVER */
+ /*
+ * Attempt to translate the GUID to a GID. Even if
+ * this fails, we will have primed the cache if it is
+ * a user record and we'll see it above the next time
+ * we're asked.
+ */
if ((error = kauth_cred_guid2gid(guidp, &gid)) != 0) {
/*
* If we have no guid -> gid translation, it's not a group and
error = 0;
}
} else {
+#if CONFIG_EXT_RESOLVER
+do_check:
+#endif /* CONFIG_EXT_RESOLVER */
error = kauth_cred_ismember_gid(cred, gid, resultp);
}
}
- return(error);
+ break;
+ }
+ return error;
+}
+
+/*
+ * kauth_cred_gid_subset
+ *
+ * Description: Given two credentials, determine if all GIDs associated with
+ * the first are also associated with the second
+ *
+ * Parameters: cred1 Credential to check for
+ * cred2 Credential to check in
+ * resultp Pointer to int to contain the
+ * result of the call
+ *
+ * Returns: 0 Success
+ * non-zero See kauth_cred_ismember_gid for
+ * error codes
+ *
+ * Implicit returns:
+ * *resultp (modified) 1 Is subset
+ * 0 Is not subset
+ *
+ * Notes: This function guarantees not to modify resultp when returning
+ * an error.
+ */
+int
+kauth_cred_gid_subset(kauth_cred_t cred1, kauth_cred_t cred2, int *resultp)
+{
+ int i, err, res = 1;
+ gid_t gid;
+ posix_cred_t pcred1 = posix_cred_get(cred1);
+ posix_cred_t pcred2 = posix_cred_get(cred2);
+
+ /* First, check the local list of groups */
+ for (i = 0; i < pcred1->cr_ngroups; i++) {
+ gid = pcred1->cr_groups[i];
+ if ((err = kauth_cred_ismember_gid(cred2, gid, &res)) != 0) {
+ return err;
+ }
+
+ if (!res && gid != pcred2->cr_rgid && gid != pcred2->cr_svgid) {
+ *resultp = 0;
+ return 0;
+ }
+ }
+
+ /* Check real gid */
+ if ((err = kauth_cred_ismember_gid(cred2, pcred1->cr_rgid, &res)) != 0) {
+ return err;
+ }
+
+ if (!res && pcred1->cr_rgid != pcred2->cr_rgid &&
+ pcred1->cr_rgid != pcred2->cr_svgid) {
+ *resultp = 0;
+ return 0;
+ }
+
+ /* Finally, check saved gid */
+ if ((err = kauth_cred_ismember_gid(cred2, pcred1->cr_svgid, &res)) != 0) {
+ return err;
+ }
+
+ if (!res && pcred1->cr_svgid != pcred2->cr_rgid &&
+ pcred1->cr_svgid != pcred2->cr_svgid) {
+ *resultp = 0;
+ return 0;
+ }
+
+ *resultp = 1;
+ return 0;
}
+
/*
- * Fast replacement for issuser()
+ * kauth_cred_issuser
+ *
+ * Description: Fast replacement for issuser()
+ *
+ * Parameters: cred Credential to check for super
+ * user privileges
+ *
+ * Returns: 0 Not super user
+ * !0 Is super user
+ *
+ * Notes: This function uses a magic number which is not a manifest
+ * constant; this is bad practice.
*/
int
kauth_cred_issuser(kauth_cred_t cred)
{
- return(cred->cr_uid == 0);
+ return kauth_cred_getuid(cred) == 0;
}
+
/*
* Credential KPI
*/
/* lock protecting credential hash table */
-static lck_mtx_t *kauth_cred_hash_mtx;
-#define KAUTH_CRED_HASH_LOCK() lck_mtx_lock(kauth_cred_hash_mtx);
-#define KAUTH_CRED_HASH_UNLOCK() lck_mtx_unlock(kauth_cred_hash_mtx);
-#if KAUTH_CRED_HASH_DEBUG
-#define KAUTH_CRED_HASH_LOCK_ASSERT() _mutex_assert(kauth_cred_hash_mtx, MA_OWNED)
-#else /* !KAUTH_CRED_HASH_DEBUG */
-#define KAUTH_CRED_HASH_LOCK_ASSERT()
-#endif /* !KAUTH_CRED_HASH_DEBUG */
+static lck_mtx_t kauth_cred_hash_mtx;
+#define KAUTH_CRED_HASH_LOCK() lck_mtx_lock(&kauth_cred_hash_mtx);
+#define KAUTH_CRED_HASH_UNLOCK() lck_mtx_unlock(&kauth_cred_hash_mtx);
+#define KAUTH_CRED_HASH_LOCK_ASSERT() LCK_MTX_ASSERT(&kauth_cred_hash_mtx, LCK_MTX_ASSERT_OWNED)
+
+/*
+ * kauth_cred_init
+ *
+ * Description: Initialize the credential hash cache
+ *
+ * Parameters: (void)
+ *
+ * Returns: (void)
+ *
+ * Notes: Intialize the credential hash cache for use; the credential
+ * hash cache is used convert duplicate credentials into a
+ * single reference counted credential in order to save wired
+ * kernel memory. In practice, this generally means a desktop
+ * system runs with a few tens of credentials, instead of one
+ * per process, one per thread, one per vnode cache entry, and
+ * so on. This generally results in savings of 200K or more
+ * (potentially much more on server systems).
+ *
+ * The hash cache internally has a reference on the credential
+ * for itself as a means of avoiding a reclaim race for a
+ * credential in the process of having it's last non-hash
+ * reference released. This would otherwise result in the
+ * possibility of a freed credential that was still in uses due
+ * a race. This use is protected by the KAUTH_CRED_HASH_LOCK.
+ *
+ * On final release, the hash reference is droped, and the
+ * credential is freed back to the system.
+ *
+ * This function is called from kauth_init() in the file
+ * kern_authorization.c.
+ */
void
kauth_cred_init(void)
{
- int i;
-
- kauth_cred_hash_mtx = lck_mtx_alloc_init(kauth_lck_grp, 0/*LCK_ATTR_NULL*/);
- kauth_cred_table_size = kauth_cred_primes[kauth_cred_primes_index];
+ lck_mtx_init(&kauth_cred_hash_mtx, kauth_lck_grp, 0 /*LCK_ATTR_NULL*/);
- /*allocate credential hash table */
- MALLOC(kauth_cred_table_anchor, struct kauth_cred_entry_head *,
- (sizeof(struct kauth_cred_entry_head) * kauth_cred_table_size),
- M_KAUTH, M_WAITOK | M_ZERO);
- for (i = 0; i < kauth_cred_table_size; i++) {
- TAILQ_INIT(&kauth_cred_table_anchor[i]);
+ for (int i = 0; i < KAUTH_CRED_TABLE_SIZE; i++) {
+ LIST_INIT(&kauth_cred_table_anchor[i]);
}
}
+
/*
- * Return the current thread's effective UID.
+ * kauth_getuid
+ *
+ * Description: Get the current thread's effective UID.
+ *
+ * Parameters: (void)
+ *
+ * Returns: (uid_t) The effective UID of the
+ * current thread
*/
uid_t
kauth_getuid(void)
{
- return(kauth_cred_get()->cr_uid);
+ return kauth_cred_getuid(kauth_cred_get());
}
+
/*
- * Return the current thread's real UID.
+ * kauth_getruid
+ *
+ * Description: Get the current thread's real UID.
+ *
+ * Parameters: (void)
+ *
+ * Returns: (uid_t) The real UID of the current
+ * thread
*/
uid_t
kauth_getruid(void)
{
- return(kauth_cred_get()->cr_ruid);
+ return kauth_cred_getruid(kauth_cred_get());
}
+
/*
- * Return the current thread's effective GID.
+ * kauth_getgid
+ *
+ * Description: Get the current thread's effective GID.
+ *
+ * Parameters: (void)
+ *
+ * Returns: (gid_t) The effective GID of the
+ * current thread
*/
gid_t
kauth_getgid(void)
{
- return(kauth_cred_get()->cr_groups[0]);
+ return kauth_cred_getgid(kauth_cred_get());
}
+
/*
- * Return the current thread's real GID.
+ * kauth_getgid
+ *
+ * Description: Get the current thread's real GID.
+ *
+ * Parameters: (void)
+ *
+ * Returns: (gid_t) The real GID of the current
+ * thread
*/
gid_t
kauth_getrgid(void)
{
- return(kauth_cred_get()->cr_rgid);
+ return kauth_cred_getrgid(kauth_cred_get());
}
+
/*
- * Returns a pointer to the current thread's credential, does not take a
- * reference (so the caller must not do anything that would let the thread's
- * credential change while using the returned value).
+ * kauth_cred_get
+ *
+ * Description: Returns a pointer to the current thread's credential
+ *
+ * Parameters: (void)
+ *
+ * Returns: (kauth_cred_t) Pointer to the current thread's
+ * credential
+ *
+ * Notes: This function does not take a reference; because of this, the
+ * caller MUST NOT do anything that would let the thread's
+ * credential change while using the returned value, without
+ * first explicitly taking their own reference.
+ *
+ * If a caller intends to take a reference on the resulting
+ * credential pointer from calling this function, it is strongly
+ * recommended that the caller use kauth_cred_get_with_ref()
+ * instead, to protect against any future changes to the cred
+ * locking protocols; such changes could otherwise potentially
+ * introduce race windows in the callers code.
*/
kauth_cred_t
kauth_cred_get(void)
uthread = get_bsdthread_info(current_thread());
/* sanity */
- if (uthread == NULL)
+ if (uthread == NULL) {
panic("thread wants credential but has no BSD thread info");
+ }
/*
- * We can lazy-bind credentials to threads, as long as their processes have them.
- * If we later inline this function, the code in this block should probably be
- * called out in a function.
+ * We can lazy-bind credentials to threads, as long as their processes
+ * have them.
+ *
+ * XXX If we later inline this function, the code in this block
+ * XXX should probably be called out in a function.
*/
if (uthread->uu_ucred == NOCRED) {
- if ((p = (proc_t) get_bsdtask_info(get_threadtask(current_thread()))) == NULL)
+ if ((p = (proc_t) get_bsdtask_info(get_threadtask(current_thread()))) == NULL) {
panic("thread wants credential but has no BSD process");
+ }
uthread->uu_ucred = kauth_cred_proc_ref(p);
}
- return(uthread->uu_ucred);
+ return uthread->uu_ucred;
}
-/*
- * Returns a pointer to the current thread's credential, takes a reference.
- */
-kauth_cred_t
-kauth_cred_get_with_ref(void)
+void
+mach_kauth_cred_uthread_update(void)
{
- struct proc *procp;
- struct uthread *uthread;
+ uthread_t uthread;
+ proc_t proc;
uthread = get_bsdthread_info(current_thread());
- /* sanity checks */
- if (uthread == NULL)
- panic("%s - thread wants credential but has no BSD thread info", __FUNCTION__);
- if ((procp = (proc_t) get_bsdtask_info(get_threadtask(current_thread()))) == NULL)
- panic("%s - thread wants credential but has no BSD process", __FUNCTION__);
+ proc = current_proc();
- /*
- * We can lazy-bind credentials to threads, as long as their processes have them.
- * If we later inline this function, the code in this block should probably be
- * called out in a function.
- */
- if (uthread->uu_ucred == NOCRED) {
- /* take reference for new cred in thread */
- uthread->uu_ucred = kauth_cred_proc_ref(procp);
- }
+ kauth_cred_uthread_update(uthread, proc);
+}
+
+/*
+ * kauth_cred_uthread_update
+ *
+ * Description: Given a uthread, a proc, and whether or not the proc is locked,
+ * late-bind the uthread cred to the proc cred.
+ *
+ * Parameters: uthread_t The uthread to update
+ * proc_t The process to update to
+ *
+ * Returns: (void)
+ *
+ * Notes: This code is common code called from system call or trap entry
+ * in the case that the process thread may have been changed
+ * since the last time the thread entered the kernel. It is
+ * generally only called with the current uthread and process as
+ * parameters.
+ */
+void
+kauth_cred_uthread_update(uthread_t uthread, proc_t proc)
+{
+ if (uthread->uu_ucred != proc->p_ucred &&
+ (uthread->uu_flag & UT_SETUID) == 0) {
+ kauth_cred_t old = uthread->uu_ucred;
+ uthread->uu_ucred = kauth_cred_proc_ref(proc);
+ if (IS_VALID_CRED(old)) {
+ kauth_cred_unref(&old);
+ }
+ }
+}
+
+
+/*
+ * kauth_cred_get_with_ref
+ *
+ * Description: Takes a reference on the current thread's credential, and then
+ * returns a pointer to it to the caller.
+ *
+ * Parameters: (void)
+ *
+ * Returns: (kauth_cred_t) Pointer to the current thread's
+ * newly referenced credential
+ *
+ * Notes: This function takes a reference on the credential before
+ * returning it to the caller.
+ *
+ * It is the responsibility of the calling code to release this
+ * reference when the credential is no longer in use.
+ *
+ * Since the returned reference may be a persistent reference
+ * (e.g. one cached in another data structure with a lifetime
+ * longer than the calling function), this release may be delayed
+ * until such time as the persistent reference is to be destroyed.
+ * An example of this would be the per vnode credential cache used
+ * to accelerate lookup operations.
+ */
+kauth_cred_t
+kauth_cred_get_with_ref(void)
+{
+ struct uthread *uthread = current_uthread();
+
+ /*
+ * We can lazy-bind credentials to threads, as long as their processes
+ * have them.
+ *
+ * XXX If we later inline this function, the code in this block
+ * XXX should probably be called out in a function.
+ */
+ if (uthread->uu_ucred == NOCRED) {
+ /* take reference for new cred in thread */
+ uthread->uu_ucred = kauth_cred_proc_ref(current_proc());
+ }
/* take a reference for our caller */
kauth_cred_ref(uthread->uu_ucred);
- return(uthread->uu_ucred);
+ return uthread->uu_ucred;
}
+
/*
- * Returns a pointer to the given process's credential, takes a reference.
+ * kauth_cred_proc_ref
+ *
+ * Description: Takes a reference on the current process's credential, and
+ * then returns a pointer to it to the caller.
+ *
+ * Parameters: procp Process whose credential we
+ * intend to take a reference on
+ *
+ * Returns: (kauth_cred_t) Pointer to the process's
+ * newly referenced credential
+ *
+ * Locks: PROC_UCRED_LOCK is held before taking the reference and released
+ * after the refeence is taken to protect the p_ucred field of
+ * the process referred to by procp.
+ *
+ * Notes: This function takes a reference on the credential before
+ * returning it to the caller.
+ *
+ * It is the responsibility of the calling code to release this
+ * reference when the credential is no longer in use.
+ *
+ * Since the returned reference may be a persistent reference
+ * (e.g. one cached in another data structure with a lifetime
+ * longer than the calling function), this release may be delayed
+ * until such time as the persistent reference is to be destroyed.
+ * An example of this would be the per vnode credential cache used
+ * to accelerate lookup operations.
*/
kauth_cred_t
kauth_cred_proc_ref(proc_t procp)
{
- kauth_cred_t cred;
-
- proc_lock(procp);
+ kauth_cred_t cred;
+
+ proc_ucred_lock(procp);
cred = proc_ucred(procp);
kauth_cred_ref(cred);
- proc_unlock(procp);
- return(cred);
+ proc_ucred_unlock(procp);
+ return cred;
}
/*
- * Allocates a new credential.
+ * kauth_cred_alloc
+ *
+ * Description: Allocate a new credential
+ *
+ * Parameters: (void)
+ *
+ * Returns: !NULL Newly allocated credential
+ * NULL Insufficient memory
+ *
+ * Notes: The newly allocated credential is zero'ed as part of the
+ * allocation process, with the exception of the reference
+ * count, which is set to 0 to indicate the caller still has
+ * to call kauth_cred_add().
+ *
+ * Since newly allocated credentials have no external pointers
+ * referencing them, prior to making them visible in an externally
+ * visible pointer (e.g. by adding them to the credential hash
+ * cache) is the only legal time in which an existing credential
+ * can be safely iinitialized or modified directly.
+ *
+ * After initialization, the caller is expected to call the
+ * function kauth_cred_add() to add the credential to the hash
+ * cache, after which time it's frozen and becomes publically
+ * visible.
+ *
+ * The release protocol depends on kauth_hash_add() being called
+ * before kauth_cred_rele() (there is a diagnostic panic which
+ * will trigger if this protocol is not observed).
+ *
+ * XXX: This function really ought to be static, rather than being
+ * exported as KPI, since a failure of kauth_cred_add() can only
+ * be handled by an explicit free of the credential; such frees
+ * depend on knowlegdge of the allocation method used, which is
+ * permitted to change between kernel revisions.
+ *
+ * XXX: In the insufficient resource case, this code panic's rather
+ * than returning a NULL pointer; the code that calls this
+ * function needs to be audited before this can be changed.
*/
-kauth_cred_t
+static kauth_cred_t
kauth_cred_alloc(void)
{
kauth_cred_t newcred;
-
- MALLOC(newcred, kauth_cred_t, sizeof(*newcred), M_CRED, M_WAITOK | M_ZERO);
+
+ MALLOC_ZONE(newcred, kauth_cred_t, sizeof(*newcred), M_CRED, M_WAITOK | M_ZERO);
+ assert(newcred);
if (newcred != 0) {
- newcred->cr_ref = 1;
+ posix_cred_t newpcred = posix_cred_get(newcred);
+ newcred->cr_audit.as_aia_p = audit_default_aia_p;
/* must do this, or cred has same group membership as uid 0 */
- newcred->cr_gmuid = KAUTH_UID_NONE;
-#if CRED_DIAGNOSTIC
- } else {
- panic("kauth_cred_alloc: couldn't allocate credential");
-#endif
+ newpcred->cr_gmuid = KAUTH_UID_NONE;
+#if CONFIG_MACF
+ mac_cred_label_init(newcred);
+#endif
}
+ return newcred;
+}
-#if KAUTH_CRED_HASH_DEBUG
- kauth_cred_count++;
-#endif
- return(newcred);
+/*
+ * kauth_cred_free
+ *
+ * Description: Destroy a credential
+ *
+ * Parameters: cred Credential to destroy.
+ */
+static void
+kauth_cred_free(kauth_cred_t cred)
+{
+ assert(os_atomic_load(&cred->cr_ref, relaxed) == 0);
+#if CONFIG_MACF
+ mac_cred_label_destroy(cred);
+#endif
+ AUDIT_SESSION_UNREF(cred);
+ FREE_ZONE(cred, sizeof(*cred), M_CRED);
}
/*
- * Looks to see if we already have a known credential and if found bumps the
- * reference count and returns it. If there are no credentials that match
- * the given credential then we allocate a new credential.
+ * kauth_cred_create
+ *
+ * Description: Look to see if we already have a known credential in the hash
+ * cache; if one is found, bump the reference count and return
+ * it. If there are no credentials that match the given
+ * credential, then allocate a new credential.
+ *
+ * Parameters: cred Template for credential to
+ * be created
+ *
+ * Returns: (kauth_cred_t) The credential that was found
+ * in the hash or created
+ * NULL kauth_cred_add() failed, or
+ * there was not an egid specified
*
- * Note that the gmuid is hard-defaulted to the UID specified. Since we maintain
- * this field, we can't expect callers to know how it needs to be set. Callers
- * should be prepared for this field to be overwritten.
+ * Notes: The gmuid is hard-defaulted to the UID specified. Since we
+ * maintain this field, we can't expect callers to know how it
+ * needs to be set. Callers should be prepared for this field
+ * to be overwritten.
*/
kauth_cred_t
kauth_cred_create(kauth_cred_t cred)
{
- kauth_cred_t found_cred, new_cred = NULL;
+ kauth_cred_t found_cred, new_cred = NULL;
+ posix_cred_t pcred = posix_cred_get(cred);
+ int is_member = 0;
- cred->cr_gmuid = cred->cr_uid;
-
- for (;;) {
- KAUTH_CRED_HASH_LOCK();
- found_cred = kauth_cred_find(cred);
- if (found_cred != NULL) {
- /* found an existing credential so we'll bump reference count and return */
- kauth_cred_ref(found_cred);
- KAUTH_CRED_HASH_UNLOCK();
- return(found_cred);
- }
- KAUTH_CRED_HASH_UNLOCK();
-
- /* no existing credential found. create one and add it to our hash table */
- new_cred = kauth_cred_alloc();
- if (new_cred != NULL) {
- int err;
- new_cred->cr_uid = cred->cr_uid;
- new_cred->cr_ruid = cred->cr_ruid;
- new_cred->cr_svuid = cred->cr_svuid;
- new_cred->cr_rgid = cred->cr_rgid;
- new_cred->cr_svgid = cred->cr_svgid;
- new_cred->cr_gmuid = cred->cr_gmuid;
- new_cred->cr_ngroups = cred->cr_ngroups;
- bcopy(&cred->cr_groups[0], &new_cred->cr_groups[0], sizeof(new_cred->cr_groups));
- KAUTH_CRED_HASH_LOCK();
- err = kauth_cred_add(new_cred);
- KAUTH_CRED_HASH_UNLOCK();
-
- /* retry if kauth_cred_add returns non zero value */
- if (err == 0)
- break;
- FREE(new_cred, M_CRED);
- new_cred = NULL;
+ if (pcred->cr_flags & CRF_NOMEMBERD) {
+ pcred->cr_gmuid = KAUTH_UID_NONE;
+ } else {
+ /*
+ * If the template credential is not opting out of external
+ * group membership resolution, then we need to check that
+ * the UID we will be using is resolvable by the external
+ * resolver. If it's not, then we opt it out anyway, since
+ * all future external resolution requests will be failing
+ * anyway, and potentially taking a long time to do it. We
+ * use gid 0 because we always know it will exist and not
+ * trigger additional lookups. This is OK, because we end up
+ * precatching the information here as a result.
+ */
+ if (!kauth_cred_ismember_gid(cred, 0, &is_member)) {
+ /*
+ * It's a recognized value; we don't really care about
+ * the answer, so long as it's something the external
+ * resolver could have vended.
+ */
+ pcred->cr_gmuid = pcred->cr_uid;
+ } else {
+ /*
+ * It's not something the external resolver could
+ * have vended, so we don't want to ask it more
+ * questions about the credential in the future. This
+ * speeds up future lookups, as long as the caller
+ * caches results; otherwise, it the same recurring
+ * cost. Since most credentials are used multiple
+ * times, we still get some performance win from this.
+ */
+ pcred->cr_gmuid = KAUTH_UID_NONE;
+ pcred->cr_flags |= CRF_NOMEMBERD;
}
}
- return(new_cred);
-}
-
-/*
- * Update the given credential using the uid argument. The given uid is used
- * set the effective user ID, real user ID, and saved user ID. We only
- * allocate a new credential when the given uid actually results in changes to
- * the existing credential.
- */
-kauth_cred_t
-kauth_cred_setuid(kauth_cred_t cred, uid_t uid)
-{
- struct ucred temp_cred;
+ /* Caller *must* specify at least the egid in cr_groups[0] */
+ if (pcred->cr_ngroups < 1) {
+ return NULL;
+ }
- NULLCRED_CHECK(cred);
+ struct kauth_cred_entry_head *bucket = kauth_cred_get_bucket(cred);
- /* don't need to do anything if the effective, real and saved user IDs are
- * already the same as the user ID passed in
- */
- if (cred->cr_uid == uid && cred->cr_ruid == uid && cred->cr_svuid == uid) {
- /* no change needed */
- return(cred);
+ KAUTH_CRED_HASH_LOCK();
+ found_cred = kauth_cred_find_and_ref(cred, bucket);
+ KAUTH_CRED_HASH_UNLOCK();
+ if (found_cred != NULL) {
+ return found_cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * No existing credential found. Create one and add it to
+ * our hash table.
*/
- bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_uid = uid;
- temp_cred.cr_ruid = uid;
- temp_cred.cr_svuid = uid;
- temp_cred.cr_gmuid = uid;
+ new_cred = kauth_cred_alloc();
+ if (new_cred != NULL) {
+ *posix_cred_get(new_cred) = *pcred;
+#if CONFIG_AUDIT
+ new_cred->cr_audit = cred->cr_audit;
+#endif
+ new_cred = kauth_cred_add(new_cred, bucket);
+ }
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ return new_cred;
}
+
/*
- * Update the given credential using the euid argument. The given uid is used
- * set the effective user ID. We only allocate a new credential when the given
- * uid actually results in changes to the existing credential.
+ * kauth_cred_setresuid
+ *
+ * Description: Update the given credential using the UID arguments. The given
+ * UIDs are used to set the effective UID, real UID, saved UID,
+ * and GMUID (used for group membership checking).
+ *
+ * Parameters: cred The original credential
+ * ruid The new real UID
+ * euid The new effective UID
+ * svuid The new saved UID
+ * gmuid KAUTH_UID_NONE -or- the new
+ * group membership UID
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * Note: gmuid is different in that a KAUTH_UID_NONE is a valid
+ * setting, so if you don't want it to change, pass it the
+ * previous value, explicitly.
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
kauth_cred_t
-kauth_cred_seteuid(kauth_cred_t cred, uid_t euid)
+kauth_cred_setresuid(kauth_cred_t cred, uid_t ruid, uid_t euid, uid_t svuid, uid_t gmuid)
{
struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred = posix_cred_get(cred);
NULLCRED_CHECK(cred);
- /* don't need to do anything if the given effective user ID is already the
- * same as the effective user ID in the credential.
+ /*
+ * We don't need to do anything if the UIDs we are changing are
+ * already the same as the UIDs passed in
*/
- if (cred->cr_uid == euid) {
+ if ((euid == KAUTH_UID_NONE || pcred->cr_uid == euid) &&
+ (ruid == KAUTH_UID_NONE || pcred->cr_ruid == ruid) &&
+ (svuid == KAUTH_UID_NONE || pcred->cr_svuid == svuid) &&
+ (pcred->cr_gmuid == gmuid)) {
/* no change needed */
- return(cred);
+ return cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * Look up in cred hash table to see if we have a matching credential
+ * with the new values; this is done by calling kauth_cred_update().
*/
bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_uid = euid;
-
- return(kauth_cred_update(cred, &temp_cred, TRUE));
-}
-
-/*
- * Update the given credential using the gid argument. The given gid is used
- * set the effective group ID, real group ID, and saved group ID. We only
- * allocate a new credential when the given gid actually results in changes to
- * the existing credential.
- */
-kauth_cred_t
-kauth_cred_setgid(kauth_cred_t cred, gid_t gid)
-{
- struct ucred temp_cred;
-
- NULLCRED_CHECK(cred);
-
- /* don't need to do anything if the given group ID is already the
- * same as the group ID in the credential.
- */
- if (cred->cr_groups[0] == gid && cred->cr_rgid == gid && cred->cr_svgid == gid) {
- /* no change needed */
- return(cred);
+ if (euid != KAUTH_UID_NONE) {
+ temp_pcred->cr_uid = euid;
+ }
+ if (ruid != KAUTH_UID_NONE) {
+ temp_pcred->cr_ruid = ruid;
+ }
+ if (svuid != KAUTH_UID_NONE) {
+ temp_pcred->cr_svuid = svuid;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * If we are setting the gmuid to KAUTH_UID_NONE, then we want to
+ * opt out of participation in external group resolution, unless we
+ * unless we explicitly opt back in later.
*/
- bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_groups[0] = gid;
- temp_cred.cr_rgid = gid;
- temp_cred.cr_svgid = gid;
+ if ((temp_pcred->cr_gmuid = gmuid) == KAUTH_UID_NONE) {
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ }
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ return kauth_cred_update(cred, &temp_cred, TRUE);
}
/*
- * Update the given credential using the egid argument. The given gid is used
- * set the effective user ID. We only allocate a new credential when the given
- * gid actually results in changes to the existing credential.
+ * kauth_cred_setresgid
+ *
+ * Description: Update the given credential using the GID arguments. The given
+ * GIDs are used to set the effective GID, real GID, and saved
+ * GID.
+ *
+ * Parameters: cred The original credential
+ * rgid The new real GID
+ * egid The new effective GID
+ * svgid The new saved GID
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
kauth_cred_t
-kauth_cred_setegid(kauth_cred_t cred, gid_t egid)
+kauth_cred_setresgid(kauth_cred_t cred, gid_t rgid, gid_t egid, gid_t svgid)
{
- struct ucred temp_cred;
+ struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred = posix_cred_get(cred);
NULLCRED_CHECK(cred);
+ DEBUG_CRED_ENTER("kauth_cred_setresgid %p %d %d %d\n", cred, rgid, egid, svgid);
- /* don't need to do anything if the given group ID is already the
- * same as the group Id in the credential.
+ /*
+ * We don't need to do anything if the given GID are already the
+ * same as the GIDs in the credential.
*/
- if (cred->cr_groups[0] == egid) {
+ if (pcred->cr_groups[0] == egid &&
+ pcred->cr_rgid == rgid &&
+ pcred->cr_svgid == svgid) {
/* no change needed */
- return(cred);
+ return cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * Look up in cred hash table to see if we have a matching credential
+ * with the new values; this is done by calling kauth_cred_update().
*/
bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_groups[0] = egid;
+ if (egid != KAUTH_GID_NONE) {
+ /* displacing a supplementary group opts us out of memberd */
+ if (kauth_cred_change_egid(&temp_cred, egid)) {
+ DEBUG_CRED_CHANGE("displaced!\n");
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ temp_pcred->cr_gmuid = KAUTH_UID_NONE;
+ } else {
+ DEBUG_CRED_CHANGE("not displaced\n");
+ }
+ }
+ if (rgid != KAUTH_GID_NONE) {
+ temp_pcred->cr_rgid = rgid;
+ }
+ if (svgid != KAUTH_GID_NONE) {
+ temp_pcred->cr_svgid = svgid;
+ }
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ return kauth_cred_update(cred, &temp_cred, TRUE);
}
+
/*
- * Update the given credential with the given groups. We only allocate a new
- * credential when the given gid actually results in changes to the existing
+ * Update the given credential with the given groups. We only allocate a new
+ * credential when the given gid actually results in changes to the existing
* credential.
* The gmuid argument supplies a new uid (or KAUTH_UID_NONE to opt out)
* which will be used for group membership checking.
*/
+/*
+ * kauth_cred_setgroups
+ *
+ * Description: Update the given credential using the provide supplementary
+ * group list and group membership UID
+ *
+ * Parameters: cred The original credential
+ * groups Pointer to gid_t array which
+ * contains the new group list
+ * groupcount The count of valid groups which
+ * are contained in 'groups'
+ * gmuid KAUTH_UID_NONE -or- the new
+ * group membership UID
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * Note: gmuid is different in that a KAUTH_UID_NONE is a valid
+ * setting, so if you don't want it to change, pass it the
+ * previous value, explicitly.
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
+ *
+ * XXX: Changes are determined in ordinal order - if the caller passes
+ * in the same groups list that is already present in the
+ * credential, but the members are in a different order, even if
+ * the EGID is not modified (i.e. cr_groups[0] is the same), it
+ * is considered a modification to the credential, and a new
+ * credential is created.
+ *
+ * This should perhaps be better optimized, but it is considered
+ * to be the caller's problem.
+ */
kauth_cred_t
kauth_cred_setgroups(kauth_cred_t cred, gid_t *groups, int groupcount, uid_t gmuid)
{
- int i;
+ int i;
struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred;
NULLCRED_CHECK(cred);
- /* don't need to do anything if the given list of groups does not change.
+ pcred = posix_cred_get(cred);
+
+ /*
+ * We don't need to do anything if the given list of groups does not
+ * change.
*/
- if ((cred->cr_gmuid == gmuid) && (cred->cr_ngroups == groupcount)) {
+ if ((pcred->cr_gmuid == gmuid) && (pcred->cr_ngroups == groupcount)) {
for (i = 0; i < groupcount; i++) {
- if (cred->cr_groups[i] != groups[i])
+ if (pcred->cr_groups[i] != groups[i]) {
break;
+ }
}
if (i == groupcount) {
/* no change needed */
- return(cred);
+ return cred;
}
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * Look up in cred hash table to see if we have a matching credential
+ * with new values. If we are setting or clearing the gmuid, then
+ * update the cr_flags, since clearing it is sticky. This permits an
+ * opt-out of memberd processing using setgroups(), and an opt-in
+ * using initgroups(). This is required for POSIX conformance.
*/
bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_ngroups = groupcount;
- bcopy(groups, temp_cred.cr_groups, sizeof(temp_cred.cr_groups));
- temp_cred.cr_gmuid = gmuid;
+ temp_pcred->cr_ngroups = groupcount;
+ bcopy(groups, temp_pcred->cr_groups, sizeof(temp_pcred->cr_groups));
+ temp_pcred->cr_gmuid = gmuid;
+ if (gmuid == KAUTH_UID_NONE) {
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ } else {
+ temp_pcred->cr_flags &= ~CRF_NOMEMBERD;
+ }
+
+ return kauth_cred_update(cred, &temp_cred, TRUE);
+}
+
+/*
+ * Notes: The return value exists to account for the possibility of a
+ * kauth_cred_t without a POSIX label. This will be the case in
+ * the future (see posix_cred_get() below, for more details).
+ */
+#if CONFIG_EXT_RESOLVER
+int kauth_external_supplementary_groups_supported = 1;
+
+SYSCTL_INT(_kern, OID_AUTO, ds_supgroups_supported, CTLFLAG_RW | CTLFLAG_LOCKED, &kauth_external_supplementary_groups_supported, 0, "");
+#endif
+
+int
+kauth_cred_getgroups(kauth_cred_t cred, gid_t *grouplist, int *countp)
+{
+ int limit = NGROUPS;
+ posix_cred_t pcred;
+
+ pcred = posix_cred_get(cred);
+
+#if CONFIG_EXT_RESOLVER
+ /*
+ * If we've not opted out of using the resolver, then convert the cred to a list
+ * of supplemental groups. We do this only if there has been a resolver to talk to,
+ * since we may be too early in boot, or in an environment that isn't using DS.
+ */
+ if (kauth_identitysvc_has_registered && kauth_external_supplementary_groups_supported && (pcred->cr_flags & CRF_NOMEMBERD) == 0) {
+ uid_t uid = kauth_cred_getuid(cred);
+ int err;
+
+ err = kauth_cred_uid2groups(&uid, grouplist, countp);
+ if (!err) {
+ return 0;
+ }
+
+ /* On error just fall through */
+ KAUTH_DEBUG("kauth_cred_getgroups failed %d\n", err);
+ }
+#endif /* CONFIG_EXT_RESOLVER */
+
+ /*
+ * If they just want a copy of the groups list, they may not care
+ * about the actual count. If they specify an input count, however,
+ * treat it as an indicator of the buffer size available in grouplist,
+ * and limit the returned list to that size.
+ */
+ if (countp) {
+ limit = MIN(*countp, pcred->cr_ngroups);
+ *countp = limit;
+ }
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ memcpy(grouplist, pcred->cr_groups, sizeof(gid_t) * limit);
+
+ return 0;
}
+
/*
- * Update the given credential using the uid and gid arguments. The given uid
- * is used set the effective user ID, real user ID, and saved user ID.
- * The given gid is used set the effective group ID, real group ID, and saved
- * group ID.
- * We only allocate a new credential when the given uid and gid actually results
- * in changes to the existing credential.
+ * kauth_cred_setuidgid
+ *
+ * Description: Update the given credential using the UID and GID arguments.
+ * The given UID is used to set the effective UID, real UID, and
+ * saved UID. The given GID is used to set the effective GID,
+ * real GID, and saved GID.
+ *
+ * Parameters: cred The original credential
+ * uid The new UID to use
+ * gid The new GID to use
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * Notes: We set the gmuid to uid if the credential we are inheriting
+ * from has not opted out of memberd participation; otherwise
+ * we set it to KAUTH_UID_NONE
+ *
+ * This code is only ever called from the per-thread credential
+ * code path in the "set per thread credential" case; and in
+ * posix_spawn() in the case that the POSIX_SPAWN_RESETIDS
+ * flag is set.
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
kauth_cred_t
kauth_cred_setuidgid(kauth_cred_t cred, uid_t uid, gid_t gid)
{
struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred;
NULLCRED_CHECK(cred);
- /* don't need to do anything if the effective, real and saved user IDs are
- * already the same as the user ID passed in
+ pcred = posix_cred_get(cred);
+
+ /*
+ * We don't need to do anything if the effective, real and saved
+ * user IDs are already the same as the user ID passed into us.
*/
- if (cred->cr_uid == uid && cred->cr_ruid == uid && cred->cr_svuid == uid &&
- cred->cr_groups[0] == gid && cred->cr_rgid == gid && cred->cr_svgid == gid) {
+ if (pcred->cr_uid == uid && pcred->cr_ruid == uid && pcred->cr_svuid == uid &&
+ pcred->cr_gid == gid && pcred->cr_rgid == gid && pcred->cr_svgid == gid) {
/* no change needed */
- return(cred);
+ return cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * Look up in cred hash table to see if we have a matching credential
+ * with the new values.
*/
bzero(&temp_cred, sizeof(temp_cred));
- temp_cred.cr_uid = uid;
- temp_cred.cr_ruid = uid;
- temp_cred.cr_svuid = uid;
- temp_cred.cr_gmuid = uid;
- temp_cred.cr_ngroups = 1;
- temp_cred.cr_groups[0] = gid;
- temp_cred.cr_rgid = gid;
- temp_cred.cr_svgid = gid;
+ temp_pcred->cr_uid = uid;
+ temp_pcred->cr_ruid = uid;
+ temp_pcred->cr_svuid = uid;
+ temp_pcred->cr_flags = pcred->cr_flags;
+ /* inherit the opt-out of memberd */
+ if (pcred->cr_flags & CRF_NOMEMBERD) {
+ temp_pcred->cr_gmuid = KAUTH_UID_NONE;
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ } else {
+ temp_pcred->cr_gmuid = uid;
+ temp_pcred->cr_flags &= ~CRF_NOMEMBERD;
+ }
+ temp_pcred->cr_ngroups = 1;
+ /* displacing a supplementary group opts us out of memberd */
+ if (kauth_cred_change_egid(&temp_cred, gid)) {
+ temp_pcred->cr_gmuid = KAUTH_UID_NONE;
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ }
+ temp_pcred->cr_rgid = gid;
+ temp_pcred->cr_svgid = gid;
+#if CONFIG_MACF
+ temp_cred.cr_label = cred->cr_label;
+#endif
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ return kauth_cred_update(cred, &temp_cred, TRUE);
}
+
/*
- * Update the given credential using the uid and gid arguments. The given uid
- * is used to set the saved user ID. The given gid is used to set the
- * saved group ID.
- * We only allocate a new credential when the given uid and gid actually results
- * in changes to the existing credential.
+ * kauth_cred_setsvuidgid
+ *
+ * Description: Function used by execve to set the saved uid and gid values
+ * for suid/sgid programs
+ *
+ * Parameters: cred The credential to update
+ * uid The saved uid to set
+ * gid The saved gid to set
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
kauth_cred_t
kauth_cred_setsvuidgid(kauth_cred_t cred, uid_t uid, gid_t gid)
{
struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred;
NULLCRED_CHECK(cred);
- /* don't need to do anything if the effective, real and saved user IDs are
- * already the same as the user ID passed in
+ pcred = posix_cred_get(cred);
+
+ DEBUG_CRED_ENTER("kauth_cred_setsvuidgid: %p u%d->%d g%d->%d\n", cred, cred->cr_svuid, uid, cred->cr_svgid, gid);
+
+ /*
+ * We don't need to do anything if the effective, real and saved
+ * uids are already the same as the uid provided. This check is
+ * likely insufficient.
*/
- if (cred->cr_svuid == uid && cred->cr_svgid == gid) {
+ if (pcred->cr_svuid == uid && pcred->cr_svgid == gid) {
/* no change needed */
- return(cred);
+ return cred;
}
+ DEBUG_CRED_CHANGE("kauth_cred_setsvuidgid: cred change\n");
/* look up in cred hash table to see if we have a matching credential
* with new values.
*/
bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_svuid = uid;
- temp_cred.cr_svgid = gid;
+ temp_pcred->cr_svuid = uid;
+ temp_pcred->cr_svgid = gid;
- return(kauth_cred_update(cred, &temp_cred, TRUE));
+ return kauth_cred_update(cred, &temp_cred, TRUE);
}
+
/*
- * Update the given credential using the given auditinfo_t.
- * We only allocate a new credential when the given auditinfo_t actually results
- * in changes to the existing credential.
+ * kauth_cred_setauditinfo
+ *
+ * Description: Update the given credential using the given au_session_t.
+ *
+ * Parameters: cred The original credential
+ * auditinfo_p Pointer to ne audit information
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
kauth_cred_t
-kauth_cred_setauditinfo(kauth_cred_t cred, auditinfo_t *auditinfo_p)
+kauth_cred_setauditinfo(kauth_cred_t cred, au_session_t *auditinfo_p)
{
struct ucred temp_cred;
NULLCRED_CHECK(cred);
- /* don't need to do anything if the audit info is already the same as the
- * audit info in the credential passed in
+ /*
+ * We don't need to do anything if the audit info is already the
+ * same as the audit info in the credential provided.
*/
- if (bcmp(&cred->cr_au, auditinfo_p, sizeof(cred->cr_au)) == 0) {
+ if (bcmp(&cred->cr_audit, auditinfo_p, sizeof(cred->cr_audit)) == 0) {
/* no change needed */
- return(cred);
+ return cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
- */
bcopy(cred, &temp_cred, sizeof(temp_cred));
- bcopy(auditinfo_p, &temp_cred.cr_au, sizeof(temp_cred.cr_au));
+ bcopy(auditinfo_p, &temp_cred.cr_audit, sizeof(temp_cred.cr_audit));
- return(kauth_cred_update(cred, &temp_cred, FALSE));
+ return kauth_cred_update(cred, &temp_cred, FALSE);
}
+#if CONFIG_MACF
/*
- * Add a reference to the passed credential.
+ * kauth_cred_label_update
+ *
+ * Description: Update the MAC label associated with a credential
+ *
+ * Parameters: cred The original credential
+ * label The MAC label to set
+ *
+ * Returns: (kauth_cred_t) The updated credential
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
-void
-kauth_cred_ref(kauth_cred_t cred)
+kauth_cred_t
+kauth_cred_label_update(kauth_cred_t cred, struct label *label)
{
- int old_value;
-
- NULLCRED_CHECK(cred);
+ kauth_cred_t newcred;
+ struct ucred temp_cred;
- old_value = OSAddAtomic(1, &cred->cr_ref);
+ bcopy(cred, &temp_cred, sizeof(temp_cred));
- if (old_value < 1)
- panic("kauth_cred_ref: trying to take a reference on a cred with no references");
-
- return;
+ mac_cred_label_init(&temp_cred);
+ mac_cred_label_associate(cred, &temp_cred);
+ mac_cred_label_update(&temp_cred, label);
+
+ newcred = kauth_cred_update(cred, &temp_cred, TRUE);
+ mac_cred_label_destroy(&temp_cred);
+ return newcred;
}
/*
- * Drop a reference from the passed credential, potentially destroying it.
+ * kauth_cred_label_update_execve
+ *
+ * Description: Update the MAC label associated with a credential as
+ * part of exec
+ *
+ * Parameters: cred The original credential
+ * vp The exec vnode
+ * scriptl The script MAC label
+ * execl The executable MAC label
+ * disjointp Pointer to flag to set if old
+ * and returned credentials are
+ * disjoint
+ *
+ * Returns: (kauth_cred_t) The updated credential
*
- * Note: Assumes credential hash is NOT locked
+ * Implicit returns:
+ * *disjointp Set to 1 for disjoint creds
+ *
+ * IMPORTANT: This function is implemented via kauth_cred_update(), which,
+ * if it returns a credential other than the one it is passed,
+ * will have dropped the reference on the passed credential. All
+ * callers should be aware of this, and treat this function as an
+ * unref + ref, potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
-void
-kauth_cred_unref(kauth_cred_t *credp)
+
+static
+kauth_cred_t
+kauth_cred_label_update_execve(kauth_cred_t cred, vfs_context_t ctx,
+ struct vnode *vp, off_t offset, struct vnode *scriptvp, struct label *scriptl,
+ struct label *execl, unsigned int *csflags, void *macextensions, int *disjointp, int *labelupdateerror)
{
- KAUTH_CRED_HASH_LOCK();
- kauth_cred_unref_hashlocked(credp);
- KAUTH_CRED_HASH_UNLOCK();
+ kauth_cred_t newcred;
+ struct ucred temp_cred;
+
+ bcopy(cred, &temp_cred, sizeof(temp_cred));
+
+ mac_cred_label_init(&temp_cred);
+ mac_cred_label_associate(cred, &temp_cred);
+ mac_cred_label_update_execve(ctx, &temp_cred,
+ vp, offset, scriptvp, scriptl, execl, csflags,
+ macextensions, disjointp, labelupdateerror);
+
+ newcred = kauth_cred_update(cred, &temp_cred, TRUE);
+ mac_cred_label_destroy(&temp_cred);
+ return newcred;
}
/*
- * Drop a reference from the passed credential, potentially destroying it.
+ * kauth_proc_label_update
+ *
+ * Description: Update the label inside the credential associated with the process.
+ *
+ * Parameters: p The process to modify
+ * label The label to place in the process credential
*
- * Note: Assumes credential hash IS locked
+ * Notes: The credential associated with the process may change as a result
+ * of this call. The caller should not assume the process reference to
+ * the old credential still exists.
*/
+int
+kauth_proc_label_update(struct proc *p, struct label *label)
+{
+ kauth_cred_t my_cred, my_new_cred;
+
+ my_cred = kauth_cred_proc_ref(p);
+
+ DEBUG_CRED_ENTER("kauth_proc_label_update: %p\n", my_cred);
+
+ /* get current credential and take a reference while we muck with it */
+ for (;;) {
+ /*
+ * Set the credential with new info. If there is no change,
+ * we get back the same credential we passed in; if there is
+ * a change, we drop the reference on the credential we
+ * passed in. The subsequent compare is safe, because it is
+ * a pointer compare rather than a contents compare.
+ */
+ my_new_cred = kauth_cred_label_update(my_cred, label);
+ if (my_cred != my_new_cred) {
+ DEBUG_CRED_CHANGE("kauth_proc_setlabel_unlocked CH(%d): %p/0x%08x -> %p/0x%08x\n", p->p_pid, my_cred, my_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
+ proc_ucred_lock(p);
+ /*
+ * We need to protect for a race where another thread
+ * also changed the credential after we took our
+ * reference. If p_ucred has changed then we should
+ * restart this again with the new cred.
+ */
+ if (p->p_ucred != my_cred) {
+ proc_ucred_unlock(p);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
+ /* try again */
+ continue;
+ }
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+
+ proc_ucred_unlock(p);
+ }
+ break;
+ }
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+
+ return 0;
+}
+
+/*
+ * kauth_proc_label_update_execve
+ *
+ * Description: Update the label inside the credential associated with the
+ * process as part of a transitioning execve. The label will
+ * be updated by the policies as part of this processing, not
+ * provided up front.
+ *
+ * Parameters: p The process to modify
+ * ctx The context of the exec
+ * vp The vnode being exec'ed
+ * scriptl The script MAC label
+ * execl The executable MAC label
+ * lupdateerror The error place holder for MAC label authority
+ * to update about possible termination
+ *
+ * Returns: 0 Label update did not make credential
+ * disjoint
+ * 1 Label update caused credential to be
+ * disjoint
+ *
+ * Notes: The credential associated with the process WILL change as a
+ * result of this call. The caller should not assume the process
+ * reference to the old credential still exists.
+ */
+
+void
+kauth_proc_label_update_execve(struct proc *p, vfs_context_t ctx,
+ struct vnode *vp, off_t offset, struct vnode *scriptvp, struct label *scriptl,
+ struct label *execl, unsigned int *csflags, void *macextensions, int *disjoint, int *update_return)
+{
+ kauth_cred_t my_cred, my_new_cred;
+ my_cred = kauth_cred_proc_ref(p);
+
+ DEBUG_CRED_ENTER("kauth_proc_label_update_execve: %p\n", my_cred);
+
+ /* get current credential and take a reference while we muck with it */
+ for (;;) {
+ /*
+ * Set the credential with new info. If there is no change,
+ * we get back the same credential we passed in; if there is
+ * a change, we drop the reference on the credential we
+ * passed in. The subsequent compare is safe, because it is
+ * a pointer compare rather than a contents compare.
+ */
+ my_new_cred = kauth_cred_label_update_execve(my_cred, ctx, vp, offset, scriptvp, scriptl, execl, csflags, macextensions, disjoint, update_return);
+ if (my_cred != my_new_cred) {
+ DEBUG_CRED_CHANGE("kauth_proc_label_update_execve_unlocked CH(%d): %p/0x%08x -> %p/0x%08x\n", p->p_pid, my_cred, my_cred->cr_flags, my_new_cred, my_new_cred->cr_flags);
+
+ proc_ucred_lock(p);
+ /*
+ * We need to protect for a race where another thread
+ * also changed the credential after we took our
+ * reference. If p_ucred has changed then we should
+ * restart this again with the new cred.
+ */
+ if (p->p_ucred != my_cred) {
+ proc_ucred_unlock(p);
+ kauth_cred_unref(&my_new_cred);
+ my_cred = kauth_cred_proc_ref(p);
+ /* try again */
+ continue;
+ }
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+ proc_ucred_unlock(p);
+ }
+ break;
+ }
+ /* Drop old proc reference or our extra reference */
+ kauth_cred_unref(&my_cred);
+}
+
+#if 1
+/*
+ * for temporary binary compatibility
+ */
+kauth_cred_t kauth_cred_setlabel(kauth_cred_t cred, struct label *label);
+kauth_cred_t
+kauth_cred_setlabel(kauth_cred_t cred, struct label *label)
+{
+ return kauth_cred_label_update(cred, label);
+}
+
+int kauth_proc_setlabel(struct proc *p, struct label *label);
+int
+kauth_proc_setlabel(struct proc *p, struct label *label)
+{
+ return kauth_proc_label_update(p, label);
+}
+#endif
+
+#else
+
+/* this is a temp hack to cover us when MACF is not built in a kernel configuration.
+ * Since we cannot build our export lists based on the kernel configuration we need
+ * to define a stub.
+ */
+kauth_cred_t
+kauth_cred_label_update(__unused kauth_cred_t cred, __unused void *label)
+{
+ return NULL;
+}
+
+int
+kauth_proc_label_update(__unused struct proc *p, __unused void *label)
+{
+ return 0;
+}
+
+#if 1
+/*
+ * for temporary binary compatibility
+ */
+kauth_cred_t kauth_cred_setlabel(kauth_cred_t cred, void *label);
+kauth_cred_t
+kauth_cred_setlabel(__unused kauth_cred_t cred, __unused void *label)
+{
+ return NULL;
+}
+
+int kauth_proc_setlabel(struct proc *p, void *label);
+int
+kauth_proc_setlabel(__unused struct proc *p, __unused void *label)
+{
+ return 0;
+}
+#endif
+#endif
+
+// TODO: move to os_refcnt once the ABI issue is resolved
+
+#define KAUTH_CRED_REF_MAX 0x0ffffffful
+
+__attribute__((noinline, cold, noreturn))
static void
-kauth_cred_unref_hashlocked(kauth_cred_t *credp)
+kauth_cred_panic_resurrection(kauth_cred_t cred)
{
- int old_value;
+ panic("kauth_cred_unref: cred %p resurrected", cred);
+ __builtin_unreachable();
+}
- KAUTH_CRED_HASH_LOCK_ASSERT();
- NULLCRED_CHECK(*credp);
- old_value = OSAddAtomic(-1, &(*credp)->cr_ref);
-
-#if DIAGNOSTIC
- if (old_value == 0)
- panic("%s:0x%08x kauth_cred_rele: dropping a reference on a cred with no references", current_proc()->p_comm, *credp);
- if (old_value == 1)
- panic("%s:0x%08x kauth_cred_rele: dropping a reference on a cred with no hash entry", current_proc()->p_comm, *credp);
+__attribute__((noinline, cold, noreturn))
+static void
+kauth_cred_panic_over_released(kauth_cred_t cred)
+{
+ panic("kauth_cred_unref: cred %p over-released", cred);
+ __builtin_unreachable();
+}
+
+__attribute__((noinline, cold, noreturn))
+static void
+kauth_cred_panic_over_retain(kauth_cred_t cred)
+{
+ panic("kauth_cred_ref: cred %p over-retained", cred);
+ __builtin_unreachable();
+}
+
+/*
+ * kauth_cred_tryref
+ *
+ * Description: Tries to take a reference, used from kauth_cred_find_and_ref
+ * to debounce the race with kauth_cred_unref.
+ *
+ * Parameters: cred The credential to reference
+ *
+ * Returns: (bool) Whether the reference was taken
+ */
+static inline bool
+kauth_cred_tryref(kauth_cred_t cred)
+{
+ u_long old_ref, new_ref;
+ os_atomic_rmw_loop(&cred->cr_ref, old_ref, new_ref, relaxed, {
+ if (old_ref == 0) {
+ os_atomic_rmw_loop_give_up(return false);
+ }
+ new_ref = old_ref + 1;
+ });
+ if (__improbable(old_ref >= KAUTH_CRED_REF_MAX)) {
+ kauth_cred_panic_over_retain(cred);
+ }
+
+#if 0 // use this to watch a specific credential
+ if (is_target_cred( *credp ) != 0) {
+ get_backtrace();
+ }
+#endif
+
+ return true;
+}
+
+/*
+ * kauth_cred_ref
+ *
+ * Description: Add a reference to the passed credential
+ *
+ * Parameters: cred The credential to reference
+ *
+ * Returns: (void)
+ */
+void
+kauth_cred_ref(kauth_cred_t cred)
+{
+ u_long old_ref = os_atomic_inc_orig(&cred->cr_ref, relaxed);
+
+ if (__improbable(old_ref < 1)) {
+ kauth_cred_panic_resurrection(cred);
+ }
+ if (__improbable(old_ref >= KAUTH_CRED_REF_MAX)) {
+ kauth_cred_panic_over_retain(cred);
+ }
+
+#if 0 // use this to watch a specific credential
+ if (is_target_cred( cred ) != 0) {
+ get_backtrace();
+ }
+#endif
+}
+
+/*
+ * kauth_cred_unref_fast
+ *
+ * Description: Release a credential reference.
+ *
+ * Parameters: credp Pointer to address containing
+ * credential to be freed
+ *
+ * Returns: true This was the last reference.
+ * false The object has more refs.
+ *
+ */
+static inline bool
+kauth_cred_unref_fast(kauth_cred_t cred)
+{
+ u_long old_ref = os_atomic_dec_orig(&cred->cr_ref, relaxed);
+
+#if 0 // use this to watch a specific credential
+ if (is_target_cred( *credp ) != 0) {
+ get_backtrace();
+ }
#endif
- if (old_value < 3) {
- /* the last reference is our credential hash table */
- kauth_cred_remove(*credp);
+ if (__improbable(old_ref <= 0)) {
+ kauth_cred_panic_over_released(cred);
}
+ return old_ref == 1;
+}
+
+/*
+ * kauth_cred_unref
+ *
+ * Description: Release a credential reference.
+ * Frees the credential if it is the last ref.
+ *
+ * Parameters: credp Pointer to address containing
+ * credential to be freed
+ *
+ * Returns: (void)
+ *
+ * Implicit returns:
+ * *credp Set to NOCRED
+ *
+ */
+void
+kauth_cred_unref(kauth_cred_t *credp)
+{
+ if (kauth_cred_unref_fast(*credp)) {
+ KAUTH_CRED_HASH_LOCK();
+ kauth_cred_remove_locked(*credp);
+ KAUTH_CRED_HASH_UNLOCK();
+ kauth_cred_free(*credp);
+ }
+
*credp = NOCRED;
}
+
+#ifndef __LP64__
+/*
+ * kauth_cred_rele
+ *
+ * Description: release a credential reference; when the last reference is
+ * released, the credential will be freed
+ *
+ * Parameters: cred Credential to release
+ *
+ * Returns: (void)
+ *
+ * DEPRECATED: This interface is obsolete due to a failure to clear out the
+ * clear the pointer in the caller to avoid multiple releases of
+ * the same credential. The currently recommended interface is
+ * kauth_cred_unref().
+ */
void
kauth_cred_rele(kauth_cred_t cred)
{
kauth_cred_unref(&cred);
}
+#endif /* !__LP64__ */
+
/*
- * Duplicate a credential.
- * NOTE - caller should call kauth_cred_add after any credential changes are made.
+ * kauth_cred_dup
+ *
+ * Description: Duplicate a credential via alloc and copy; the new credential
+ * has only it's own
+ *
+ * Parameters: cred The credential to duplicate
+ *
+ * Returns: (kauth_cred_t) The duplicate credential
+ *
+ * Notes: The typical value to calling this routine is if you are going
+ * to modify an existing credential, and expect to need a new one
+ * from the hash cache.
+ *
+ * This should probably not be used in the majority of cases;
+ * if you are using it instead of kauth_cred_create(), you are
+ * likely making a mistake.
+ *
+ * The newly allocated credential is copied as part of the
+ * allocation process, with the exception of the reference
+ * count, which is set to 0 to indicate the caller still has
+ * to call kauth_cred_add().
+ *
+ * Since newly allocated credentials have no external pointers
+ * referencing them, prior to making them visible in an externally
+ * visible pointer (e.g. by adding them to the credential hash
+ * cache) is the only legal time in which an existing credential
+ * can be safely initialized or modified directly.
+ *
+ * After initialization, the caller is expected to call the
+ * function kauth_cred_add() to add the credential to the hash
+ * cache, after which time it's frozen and becomes publicly
+ * visible.
+ *
+ * The release protocol depends on kauth_hash_add() being called
+ * before kauth_cred_rele() (there is a diagnostic panic which
+ * will trigger if this protocol is not observed).
+ *
*/
-kauth_cred_t
+static kauth_cred_t
kauth_cred_dup(kauth_cred_t cred)
{
kauth_cred_t newcred;
-
-#if CRED_DIAGNOSTIC
- if (cred == NOCRED || cred == FSCRED)
- panic("kauth_cred_dup: bad credential");
-#endif
+
+ assert(cred != NOCRED && cred != FSCRED);
newcred = kauth_cred_alloc();
if (newcred != NULL) {
- bcopy(cred, newcred, sizeof(*newcred));
- newcred->cr_ref = 1;
+ newcred->cr_posix = cred->cr_posix;
+#if CONFIG_AUDIT
+ newcred->cr_audit = cred->cr_audit;
+#endif
+#if CONFIG_MACF
+ mac_cred_label_associate(cred, newcred);
+#endif
+ AUDIT_SESSION_REF(cred);
}
- return(newcred);
+ return newcred;
}
/*
- * Returns a credential based on the passed credential but which
- * reflects the real rather than effective UID and GID.
- * NOTE - we do NOT decrement cred reference count on passed in credential
+ * kauth_cred_copy_real
+ *
+ * Description: Returns a credential based on the passed credential but which
+ * reflects the real rather than effective UID and GID.
+ *
+ * Parameters: cred The credential from which to
+ * derive the new credential
+ *
+ * Returns: (kauth_cred_t) The copied credential
+ *
+ * IMPORTANT: This function DOES NOT utilize kauth_cred_update(); as a
+ * result, the caller is responsible for dropping BOTH the
+ * additional reference on the passed cred (if any), and the
+ * credential returned by this function. The drop should be
+ * via the kauth_cred_unref() KPI.
*/
kauth_cred_t
kauth_cred_copy_real(kauth_cred_t cred)
{
kauth_cred_t newcred = NULL, found_cred;
struct ucred temp_cred;
+ posix_cred_t temp_pcred = posix_cred_get(&temp_cred);
+ posix_cred_t pcred = posix_cred_get(cred);
/* if the credential is already 'real', just take a reference */
- if ((cred->cr_ruid == cred->cr_uid) &&
- (cred->cr_rgid == cred->cr_gid)) {
+ if ((pcred->cr_ruid == pcred->cr_uid) &&
+ (pcred->cr_rgid == pcred->cr_gid)) {
kauth_cred_ref(cred);
- return(cred);
+ return cred;
}
- /* look up in cred hash table to see if we have a matching credential
- * with new values.
+ /*
+ * Look up in cred hash table to see if we have a matching credential
+ * with the new values.
*/
bcopy(cred, &temp_cred, sizeof(temp_cred));
- temp_cred.cr_uid = cred->cr_ruid;
- temp_cred.cr_groups[0] = cred->cr_rgid;
+ temp_pcred->cr_uid = pcred->cr_ruid;
+ /* displacing a supplementary group opts us out of memberd */
+ if (kauth_cred_change_egid(&temp_cred, pcred->cr_rgid)) {
+ temp_pcred->cr_flags |= CRF_NOMEMBERD;
+ temp_pcred->cr_gmuid = KAUTH_UID_NONE;
+ }
/*
- * if the cred is not opted out, make sure we are using the r/euid
+ * If the cred is not opted out, make sure we are using the r/euid
* for group checks
*/
- if (temp_cred.cr_gmuid != KAUTH_UID_NONE)
- temp_cred.cr_gmuid = cred->cr_ruid;
+ if (temp_pcred->cr_gmuid != KAUTH_UID_NONE) {
+ temp_pcred->cr_gmuid = pcred->cr_ruid;
+ }
- for (;;) {
- int err;
-
- KAUTH_CRED_HASH_LOCK();
- found_cred = kauth_cred_find(&temp_cred);
- if (found_cred == cred) {
- /* same cred so just bail */
- KAUTH_CRED_HASH_UNLOCK();
- return(cred);
- }
- if (found_cred != NULL) {
- /*
- * found a match so we bump reference count on new one.
- * we leave the old one alone.
- */
- kauth_cred_ref(found_cred);
- KAUTH_CRED_HASH_UNLOCK();
- return(found_cred);
- }
-
- /* must allocate a new credential, copy in old credential data and update
- * with real user and group IDs.
- */
- newcred = kauth_cred_dup(&temp_cred);
- err = kauth_cred_add(newcred);
- KAUTH_CRED_HASH_UNLOCK();
+ struct kauth_cred_entry_head *bucket = kauth_cred_get_bucket(cred);
- /* retry if kauth_cred_add returns non zero value */
- if (err == 0)
- break;
- FREE(newcred, M_CRED);
- newcred = NULL;
+ KAUTH_CRED_HASH_LOCK();
+ found_cred = kauth_cred_find_and_ref(&temp_cred, bucket);
+ KAUTH_CRED_HASH_UNLOCK();
+
+ if (found_cred) {
+ return found_cred;
}
-
- return(newcred);
+
+ /*
+ * Must allocate a new credential, copy in old credential
+ * data and update the real user and group IDs.
+ */
+ newcred = kauth_cred_dup(&temp_cred);
+ return kauth_cred_add(newcred, bucket);
}
-
+
+
/*
- * Common code to update a credential. model_cred is a temporary, non
- * reference counted credential used only for comparison and modeling
- * purposes. old_cred is a live reference counted credential that we
- * intend to update using model_cred as our model.
+ * kauth_cred_update
+ *
+ * Description: Common code to update a credential
+ *
+ * Parameters: old_cred Reference counted credential
+ * to update
+ * model_cred Non-reference counted model
+ * credential to apply to the
+ * credential to be updated
+ * retain_auditinfo Flag as to whether or not the
+ * audit information should be
+ * copied from the old_cred into
+ * the model_cred
+ *
+ * Returns: (kauth_cred_t) The updated credential
*
- * IMPORTANT: If the old_cred ends up updated by this process, we will, as
- * a side effect, drop the reference we held on it going in.
+ * IMPORTANT: This function will potentially return a credential other than
+ * the one it is passed, and if so, it will have dropped the
+ * reference on the passed credential. All callers should be
+ * aware of this, and treat this function as an unref + ref,
+ * potentially on different credentials.
+ *
+ * Because of this, the caller is expected to take its own
+ * reference on the credential passed as the first parameter,
+ * and be prepared to release the reference on the credential
+ * that is returned to them, if it is not intended to be a
+ * persistent reference.
*/
static kauth_cred_t
-kauth_cred_update(kauth_cred_t old_cred, kauth_cred_t model_cred, boolean_t retain_auditinfo)
-{
- kauth_cred_t found_cred, new_cred = NULL;
-
- /* make sure we carry the auditinfo forward to the new credential unless
- * we are actually updating the auditinfo.
+kauth_cred_update(kauth_cred_t old_cred, kauth_cred_t model_cred,
+ boolean_t retain_auditinfo)
+{
+ kauth_cred_t cred;
+
+ /*
+ * Make sure we carry the auditinfo forward to the new credential
+ * unless we are actually updating the auditinfo.
*/
- if (retain_auditinfo)
- bcopy(&old_cred->cr_au, &model_cred->cr_au, sizeof(model_cred->cr_au));
-
- for (;;) {
- int err;
+ if (retain_auditinfo) {
+ model_cred->cr_audit = old_cred->cr_audit;
+ }
- KAUTH_CRED_HASH_LOCK();
- found_cred = kauth_cred_find(model_cred);
- if (found_cred == old_cred) {
- /* same cred so just bail */
- KAUTH_CRED_HASH_UNLOCK();
- return(old_cred);
- }
- if (found_cred != NULL) {
- /*
- * found a match so we bump reference count on new
- * one and decrement reference count on the old one.
- */
- kauth_cred_ref(found_cred);
- kauth_cred_unref_hashlocked(&old_cred);
- KAUTH_CRED_HASH_UNLOCK();
- return(found_cred);
- }
-
- /* must allocate a new credential using the model. also
- * adds the new credential to the credential hash table.
+ if (kauth_cred_is_equal(old_cred, model_cred)) {
+ return old_cred;
+ }
+
+ struct kauth_cred_entry_head *bucket = kauth_cred_get_bucket(model_cred);
+
+ KAUTH_CRED_HASH_LOCK();
+ cred = kauth_cred_find_and_ref(model_cred, bucket);
+ if (cred != NULL) {
+ /*
+ * We found a hit, so we can get rid of the old_cred.
+ * If we didn't, then we need to keep the old_cred around,
+ * because `model_cred` has copies of things such as the cr_label
+ * or audit session that it has not refcounts for.
*/
- new_cred = kauth_cred_dup(model_cred);
- err = kauth_cred_add(new_cred);
+ bool needs_free = kauth_cred_unref_fast(old_cred);
+ if (needs_free) {
+ kauth_cred_remove_locked(old_cred);
+ }
KAUTH_CRED_HASH_UNLOCK();
- /* retry if kauth_cred_add returns non zero value */
- if (err == 0)
- break;
- FREE(new_cred, M_CRED);
- new_cred = NULL;
+ DEBUG_CRED_CHANGE("kauth_cred_update(cache hit): %p -> %p\n",
+ old_cred, cred);
+ if (needs_free) {
+ kauth_cred_free(old_cred);
+ }
+ return cred;
}
+ KAUTH_CRED_HASH_UNLOCK();
+
+ /*
+ * Must allocate a new credential using the model. also
+ * adds the new credential to the credential hash table.
+ */
+ cred = kauth_cred_dup(model_cred);
+ cred = kauth_cred_add(cred, bucket);
+ DEBUG_CRED_CHANGE("kauth_cred_update(cache miss): %p -> %p\n",
+ old_cred, cred);
+
+
+ /*
+ * This can't be done before the kauth_cred_dup() as the model_cred
+ * has pointers that old_cred owns references for.
+ */
kauth_cred_unref(&old_cred);
- return(new_cred);
+ return cred;
}
-/*
- * Add the given credential to our credential hash table and take an additional
- * reference to account for our use of the credential in the hash table.
- * NOTE - expects caller to hold KAUTH_CRED_HASH_LOCK!
+
+/*
+ * kauth_cred_add
+ *
+ * Description: Add the given credential to our credential hash table and
+ * take an initial reference to account for the object being
+ * now valid.
+ *
+ * Parameters: new_cred Credential to insert into cred
+ * hash cache, or to destroy when
+ * a collision is detected.
+ *
+ * Returns: (kauth_thread_t) The inserted cred, or the
+ * collision that was found.
+ *
+ * Notes: The 'new_cred' MUST NOT already be in the cred hash cache
*/
-static int
-kauth_cred_add(kauth_cred_t new_cred)
+static kauth_cred_t
+kauth_cred_add(kauth_cred_t new_cred, struct kauth_cred_entry_head *bucket)
{
- u_long hash_key;
+ kauth_cred_t found_cred;
+ u_long old_ref;
- KAUTH_CRED_HASH_LOCK_ASSERT();
-
- hash_key = kauth_cred_get_hashkey(new_cred);
- hash_key %= kauth_cred_table_size;
+ KAUTH_CRED_HASH_LOCK();
+ found_cred = kauth_cred_find_and_ref(new_cred, bucket);
+ if (found_cred) {
+ KAUTH_CRED_HASH_UNLOCK();
+ kauth_cred_free(new_cred);
+ return found_cred;
+ }
- /* race fix - there is a window where another matching credential
- * could have been inserted between the time this one was created and we
- * got the hash lock. If we find a match return an error and have the
- * the caller retry.
- */
- if (kauth_cred_find(new_cred) != NULL) {
- return(-1);
+ old_ref = os_atomic_xchg(&new_cred->cr_ref, 1, relaxed);
+ if (old_ref != 0) {
+ panic("kauth_cred_add: invalid cred %p", new_cred);
}
-
- /* take a reference for our use in credential hash table */
- kauth_cred_ref(new_cred);
/* insert the credential into the hash table */
- TAILQ_INSERT_HEAD(&kauth_cred_table_anchor[hash_key], new_cred, cr_link);
-
- return(0);
-}
+ LIST_INSERT_HEAD(bucket, new_cred, cr_link);
+ KAUTH_CRED_HASH_UNLOCK();
+ return new_cred;
+}
-/*
- * Remove the given credential from our credential hash table.
- * NOTE - expects caller to hold KAUTH_CRED_HASH_LOCK!
+/*
+ * kauth_cred_remove_locked
+ *
+ * Description: Remove the given credential from our credential hash table.
+ *
+ * Parameters: cred Credential to remove.
+ *
+ * Locks: Caller is expected to hold KAUTH_CRED_HASH_LOCK
*/
static void
-kauth_cred_remove(kauth_cred_t cred)
+kauth_cred_remove_locked(kauth_cred_t cred)
{
- u_long hash_key;
- kauth_cred_t found_cred;
-
KAUTH_CRED_HASH_LOCK_ASSERT();
- hash_key = kauth_cred_get_hashkey(cred);
- hash_key %= kauth_cred_table_size;
-
- /* avoid race */
- if (cred->cr_ref < 1)
- panic("cred reference underflow");
- if (cred->cr_ref > 1) {
- return; /* someone else got a ref */
+ if (cred->cr_link.le_prev == NULL) {
+ panic("kauth_cred_unref: cred %p never added", cred);
}
- /* find cred in the credential hash table */
- TAILQ_FOREACH(found_cred, &kauth_cred_table_anchor[hash_key], cr_link) {
- if (found_cred == cred) {
- /* found a match, remove it from the hash table */
- TAILQ_REMOVE(&kauth_cred_table_anchor[hash_key], found_cred, cr_link);
- FREE(cred, M_CRED);
-#if KAUTH_CRED_HASH_DEBUG
- kauth_cred_count--;
-#endif
- return;
- }
- }
-
- /* did not find a match. this should not happen! */
- printf("%s:%s - %d - %s - did not find a match for 0x%08x\n", __FILE__, __LINE__, __FUNCTION__, current_proc()->p_comm, cred);
- return;
+ LIST_REMOVE(cred, cr_link);
}
-/*
- * Using the given credential data, look for a match in our credential hash
- * table.
- * NOTE - expects caller to hold KAUTH_CRED_HASH_LOCK!
+/*
+ * kauth_cred_is_equal
+ *
+ * Description: Returns whether two credentions are identical.
+ *
+ * Parameters: cred1 Credential to compare
+ * cred2 Credential to compare
+ *
+ * Returns: true Credentials are equal
+ * false Credentials are different
*/
-kauth_cred_t
-kauth_cred_find(kauth_cred_t cred)
+static bool
+kauth_cred_is_equal(kauth_cred_t cred1, kauth_cred_t cred2)
{
- u_long hash_key;
- kauth_cred_t found_cred;
-
- KAUTH_CRED_HASH_LOCK_ASSERT();
+ posix_cred_t pcred1 = posix_cred_get(cred1);
+ posix_cred_t pcred2 = posix_cred_get(cred2);
-#if KAUTH_CRED_HASH_DEBUG
- static int test_count = 0;
-
- test_count++;
- if ((test_count % 200) == 0) {
- kauth_cred_hash_print();
+ /*
+ * don't worry about the label unless the flags in
+ * either credential tell us to.
+ */
+ if (memcmp(pcred1, pcred2, sizeof(*pcred1))) {
+ return false;
+ }
+ if (memcmp(&cred1->cr_audit, &cred2->cr_audit, sizeof(cred1->cr_audit))) {
+ return false;
+ }
+#if CONFIG_MACF
+ /* Note: we know the flags are equal, so we only need to test one */
+ if (pcred1->cr_flags & CRF_MAC_ENFORCE) {
+ if (!mac_cred_label_compare(cred1->cr_label, cred2->cr_label)) {
+ return false;
+ }
}
#endif
+ return true;
+}
- hash_key = kauth_cred_get_hashkey(cred);
- hash_key %= kauth_cred_table_size;
+/*
+ * kauth_cred_find_and_ref
+ *
+ * Description: Using the given credential data, look for a match in our
+ * credential hash table
+ *
+ * Parameters: cred Credential to lookup in cred
+ * hash cache
+ *
+ * Returns: NULL Not found
+ * !NULL Matching credential already in
+ * cred hash cache, with a +1 ref
+ *
+ * Locks: Caller is expected to hold KAUTH_CRED_HASH_LOCK
+ */
+static kauth_cred_t
+kauth_cred_find_and_ref(kauth_cred_t cred, struct kauth_cred_entry_head *bucket)
+{
+ kauth_cred_t found_cred;
- /* find cred in the credential hash table */
- TAILQ_FOREACH(found_cred, &kauth_cred_table_anchor[hash_key], cr_link) {
- if (bcmp(&found_cred->cr_uid, &cred->cr_uid, (sizeof(struct ucred) - offsetof(struct ucred, cr_uid))) == 0) {
- /* found a match */
- return(found_cred);
+ KAUTH_CRED_HASH_LOCK_ASSERT();
+
+ /* Find cred in the credential hash table */
+ LIST_FOREACH(found_cred, bucket, cr_link) {
+ if (kauth_cred_is_equal(found_cred, cred)) {
+ /*
+ * newer entries are inserted at the head,
+ * no hit further in the chain can possibly
+ * be successfully retained.
+ */
+ if (!kauth_cred_tryref(found_cred)) {
+ found_cred = NULL;
+ }
+ break;
}
}
- /* no match found */
- return(NULL);
+
+ return found_cred;
}
/*
- * Generates a hash key using data that makes up a credential. Based on ElfHash.
+ * kauth_cred_find
+ *
+ * Description: This interface is sadly KPI but people can't possibly use it,
+ * as they need to hold a lock that isn't exposed.
+ *
+ * Parameters: cred Credential to lookup in cred
+ * hash cache
+ *
+ * Returns: NULL Not found
+ * !NULL Matching credential already in
+ * cred hash cache
+ *
+ * Locks: Caller is expected to hold KAUTH_CRED_HASH_LOCK
*/
-static u_long
-kauth_cred_get_hashkey(kauth_cred_t cred)
+kauth_cred_t
+kauth_cred_find(kauth_cred_t cred)
{
- u_long hash_key = 0;
-
- hash_key = kauth_cred_hash((uint8_t *)&cred->cr_uid,
- (sizeof(struct ucred) - offsetof(struct ucred, cr_uid)),
- hash_key);
- return(hash_key);
+ struct kauth_cred_entry_head *bucket = kauth_cred_get_bucket(cred);
+ kauth_cred_t found_cred;
+
+ KAUTH_CRED_HASH_LOCK_ASSERT();
+
+ /* Find cred in the credential hash table */
+ LIST_FOREACH(found_cred, bucket, cr_link) {
+ if (kauth_cred_is_equal(found_cred, cred)) {
+ break;
+ }
+ }
+
+ return found_cred;
}
+
/*
- * Generates a hash key using data that makes up a credential. Based on ElfHash.
+ * kauth_cred_hash
+ *
+ * Description: Generates a hash key using data that makes up a credential;
+ * based on ElfHash
+ *
+ * Parameters: datap Pointer to data to hash
+ * data_len Count of bytes to hash
+ * start_key Start key value
+ *
+ * Returns: (u_long) Returned hash key
*/
-static inline u_long kauth_cred_hash(const uint8_t *datap, int data_len, u_long start_key)
+static inline u_long
+kauth_cred_hash(const uint8_t *datap, int data_len, u_long start_key)
{
- u_long hash_key = start_key;
- u_long temp;
+ u_long hash_key = start_key;
+ u_long temp;
while (data_len > 0) {
hash_key = (hash_key << 4) + *datap++;
hash_key &= ~temp;
data_len--;
}
- return(hash_key);
+ return hash_key;
+}
+
+
+/*
+ * kauth_cred_get_bucket
+ *
+ * Description: Generate a hash key using data that makes up a credential;
+ * based on ElfHash. We hash on the entire credential data,
+ * not including the ref count or the TAILQ, which are mutable;
+ * everything else isn't.
+ *
+ * Returns the bucket correspondong to this hash key.
+ *
+ * Parameters: cred Credential for which hash is
+ * desired
+ *
+ * Returns: (kauth_cred_entry_head *) Returned bucket.
+ *
+ * Notes: When actually moving the POSIX credential into a real label,
+ * remember to update this hash computation.
+ */
+static struct kauth_cred_entry_head *
+kauth_cred_get_bucket(kauth_cred_t cred)
+{
+#if CONFIG_MACF
+ posix_cred_t pcred = posix_cred_get(cred);
+#endif
+ u_long hash_key = 0;
+
+ hash_key = kauth_cred_hash((uint8_t *)&cred->cr_posix,
+ sizeof(struct posix_cred),
+ hash_key);
+ hash_key = kauth_cred_hash((uint8_t *)&cred->cr_audit,
+ sizeof(struct au_session),
+ hash_key);
+#if CONFIG_MACF
+ if (pcred->cr_flags & CRF_MAC_ENFORCE) {
+ hash_key = kauth_cred_hash((uint8_t *)cred->cr_label,
+ sizeof(struct label),
+ hash_key);
+ }
+#endif
+
+ hash_key %= KAUTH_CRED_TABLE_SIZE;
+ return &kauth_cred_table_anchor[hash_key];
}
-#if KAUTH_CRED_HASH_DEBUG
-static void kauth_cred_hash_print(void)
+
+#ifdef DEBUG_CRED
+/*
+ * kauth_cred_print
+ *
+ * Description: Print out an individual credential's contents for debugging
+ * purposes
+ *
+ * Parameters: cred The credential to print out
+ *
+ * Returns: (void)
+ *
+ * Implicit returns: Results in console output
+ */
+void
+kauth_cred_print(kauth_cred_t cred)
{
- int i, j;
- kauth_cred_t found_cred;
-
- printf("\n\t kauth credential hash table statistics - current cred count %d \n", kauth_cred_count);
- /* count slot hits, misses, collisions, and max depth */
- for (i = 0; i < kauth_cred_table_size; i++) {
- printf("[%02d] ", i);
- j = 0;
+ int i;
+
+ printf("%p - refs %lu flags 0x%08x uids e%d r%d sv%d gm%d ", cred, cred->cr_ref, cred->cr_flags, cred->cr_uid, cred->cr_ruid, cred->cr_svuid, cred->cr_gmuid);
+ printf("group count %d gids ", cred->cr_ngroups);
+ for (i = 0; i < NGROUPS; i++) {
+ if (i == 0) {
+ printf("e");
+ }
+ printf("%d ", cred->cr_groups[i]);
+ }
+ printf("r%d sv%d ", cred->cr_rgid, cred->cr_svgid);
+ printf("auditinfo_addr %d %d %d %d %d %d\n",
+ cred->cr_audit.s_aia_p->ai_auid,
+ cred->cr_audit.as_mask.am_success,
+ cred->cr_audit.as_mask.am_failure,
+ cred->cr_audit.as_aia_p->ai_termid.at_port,
+ cred->cr_audit.as_aia_p->ai_termid.at_addr[0],
+ cred->cr_audit.as_aia_p->ai_asid);
+}
+
+int
+is_target_cred( kauth_cred_t the_cred )
+{
+ if (the_cred->cr_uid != 0) {
+ return 0;
+ }
+ if (the_cred->cr_ruid != 0) {
+ return 0;
+ }
+ if (the_cred->cr_svuid != 0) {
+ return 0;
+ }
+ if (the_cred->cr_ngroups != 11) {
+ return 0;
+ }
+ if (the_cred->cr_groups[0] != 11) {
+ return 0;
+ }
+ if (the_cred->cr_groups[1] != 81) {
+ return 0;
+ }
+ if (the_cred->cr_groups[2] != 63947) {
+ return 0;
+ }
+ if (the_cred->cr_groups[3] != 80288) {
+ return 0;
+ }
+ if (the_cred->cr_groups[4] != 89006) {
+ return 0;
+ }
+ if (the_cred->cr_groups[5] != 52173) {
+ return 0;
+ }
+ if (the_cred->cr_groups[6] != 84524) {
+ return 0;
+ }
+ if (the_cred->cr_groups[7] != 79) {
+ return 0;
+ }
+ if (the_cred->cr_groups[8] != 80292) {
+ return 0;
+ }
+ if (the_cred->cr_groups[9] != 80) {
+ return 0;
+ }
+ if (the_cred->cr_groups[10] != 90824) {
+ return 0;
+ }
+ if (the_cred->cr_rgid != 11) {
+ return 0;
+ }
+ if (the_cred->cr_svgid != 11) {
+ return 0;
+ }
+ if (the_cred->cr_gmuid != 3475) {
+ return 0;
+ }
+ if (the_cred->cr_audit.as_aia_p->ai_auid != 3475) {
+ return 0;
+ }
+/*
+ * if ( the_cred->cr_audit.as_mask.am_success != 0 )
+ * return( 0 );
+ * if ( the_cred->cr_audit.as_mask.am_failure != 0 )
+ * return( 0 );
+ * if ( the_cred->cr_audit.as_aia_p->ai_termid.at_port != 0 )
+ * return( 0 );
+ * if ( the_cred->cr_audit.as_aia_p->ai_termid.at_addr[0] != 0 )
+ * return( 0 );
+ * if ( the_cred->cr_audit.as_aia_p->ai_asid != 0 )
+ * return( 0 );
+ * if ( the_cred->cr_flags != 0 )
+ * return( 0 );
+ */
+ return -1; // found target cred
+}
+
+void
+get_backtrace( void )
+{
+ int my_slot;
+ void * my_stack[MAX_STACK_DEPTH];
+ int i, my_depth;
+
+ if (cred_debug_buf_p == NULL) {
+ MALLOC(cred_debug_buf_p, cred_debug_buffer *, sizeof(*cred_debug_buf_p), M_KAUTH, M_WAITOK);
+ bzero(cred_debug_buf_p, sizeof(*cred_debug_buf_p));
+ }
+
+ if (cred_debug_buf_p->next_slot > (MAX_CRED_BUFFER_SLOTS - 1)) {
+ /* buffer is full */
+ return;
+ }
+
+ my_depth = OSBacktrace(&my_stack[0], MAX_STACK_DEPTH);
+ if (my_depth == 0) {
+ printf("%s - OSBacktrace failed \n", __FUNCTION__);
+ return;
+ }
+
+ /* fill new backtrace */
+ my_slot = cred_debug_buf_p->next_slot;
+ cred_debug_buf_p->next_slot++;
+ cred_debug_buf_p->stack_buffer[my_slot].depth = my_depth;
+ for (i = 0; i < my_depth; i++) {
+ cred_debug_buf_p->stack_buffer[my_slot].stack[i] = my_stack[i];
+ }
+
+ return;
+}
+
+
+/* subset of struct ucred for use in sysctl_dump_creds */
+struct debug_ucred {
+ void *credp;
+ u_long cr_ref; /* reference count */
+ uid_t cr_uid; /* effective user id */
+ uid_t cr_ruid; /* real user id */
+ uid_t cr_svuid; /* saved user id */
+ short cr_ngroups; /* number of groups in advisory list */
+ gid_t cr_groups[NGROUPS]; /* advisory group list */
+ gid_t cr_rgid; /* real group id */
+ gid_t cr_svgid; /* saved group id */
+ uid_t cr_gmuid; /* UID for group membership purposes */
+ struct auditinfo_addr cr_audit; /* user auditing data. */
+ void *cr_label; /* MACF label */
+ int cr_flags; /* flags on credential */
+};
+typedef struct debug_ucred debug_ucred;
+
+SYSCTL_PROC(_kern, OID_AUTO, dump_creds, CTLFLAG_RD,
+ NULL, 0, sysctl_dump_creds, "S,debug_ucred", "List of credentials in the cred hash");
+
+/* accessed by:
+ * err = sysctlbyname( "kern.dump_creds", bufp, &len, NULL, 0 );
+ */
+
+static int
+sysctl_dump_creds( __unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req )
+{
+ int i, j, counter = 0;
+ int error;
+ size_t space;
+ kauth_cred_t found_cred;
+ debug_ucred * cred_listp;
+ debug_ucred * nextp;
+
+ /* This is a readonly node. */
+ if (req->newptr != USER_ADDR_NULL) {
+ return EPERM;
+ }
+
+ /* calculate space needed */
+ for (i = 0; i < KAUTH_CRED_TABLE_SIZE; i++) {
TAILQ_FOREACH(found_cred, &kauth_cred_table_anchor[i], cr_link) {
- if (j > 0) {
- printf("---- ");
+ counter++;
+ }
+ }
+
+ /* they are querying us so just return the space required. */
+ if (req->oldptr == USER_ADDR_NULL) {
+ counter += 10; // add in some padding;
+ req->oldidx = counter * sizeof(debug_ucred);
+ return 0;
+ }
+
+ MALLOC( cred_listp, debug_ucred *, req->oldlen, M_TEMP, M_WAITOK | M_ZERO);
+ if (cred_listp == NULL) {
+ return ENOMEM;
+ }
+
+ /* fill in creds to send back */
+ nextp = cred_listp;
+ space = 0;
+ for (i = 0; i < KAUTH_CRED_TABLE_SIZE; i++) {
+ TAILQ_FOREACH(found_cred, &kauth_cred_table_anchor[i], cr_link) {
+ nextp->credp = found_cred;
+ nextp->cr_ref = found_cred->cr_ref;
+ nextp->cr_uid = found_cred->cr_uid;
+ nextp->cr_ruid = found_cred->cr_ruid;
+ nextp->cr_svuid = found_cred->cr_svuid;
+ nextp->cr_ngroups = found_cred->cr_ngroups;
+ for (j = 0; j < nextp->cr_ngroups; j++) {
+ nextp->cr_groups[j] = found_cred->cr_groups[j];
+ }
+ nextp->cr_rgid = found_cred->cr_rgid;
+ nextp->cr_svgid = found_cred->cr_svgid;
+ nextp->cr_gmuid = found_cred->cr_gmuid;
+ nextp->cr_audit.ai_auid =
+ found_cred->cr_audit.as_aia_p->ai_auid;
+ nextp->cr_audit.ai_mask.am_success =
+ found_cred->cr_audit.as_mask.am_success;
+ nextp->cr_audit.ai_mask.am_failure =
+ found_cred->cr_audit.as_mask.am_failure;
+ nextp->cr_audit.ai_termid.at_port =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_port;
+ nextp->cr_audit.ai_termid.at_type =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_type;
+ nextp->cr_audit.ai_termid.at_addr[0] =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_addr[0];
+ nextp->cr_audit.ai_termid.at_addr[1] =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_addr[1];
+ nextp->cr_audit.ai_termid.at_addr[2] =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_addr[2];
+ nextp->cr_audit.ai_termid.at_addr[3] =
+ found_cred->cr_audit.as_aia_p->ai_termid.at_addr[3];
+ nextp->cr_audit.ai_asid =
+ found_cred->cr_audit.as_aia_p->ai_asid;
+ nextp->cr_audit.ai_flags =
+ found_cred->cr_audit.as_aia_p->ai_flags;
+ nextp->cr_label = found_cred->cr_label;
+ nextp->cr_flags = found_cred->cr_flags;
+ nextp++;
+ space += sizeof(debug_ucred);
+ if (space > req->oldlen) {
+ FREE(cred_listp, M_TEMP);
+ return ENOMEM;
}
- j++;
- kauth_cred_print(found_cred);
- printf("\n");
}
- if (j == 0) {
- printf("NOCRED \n");
+ }
+ req->oldlen = space;
+ error = SYSCTL_OUT(req, cred_listp, req->oldlen);
+ FREE(cred_listp, M_TEMP);
+ return error;
+}
+
+
+SYSCTL_PROC(_kern, OID_AUTO, cred_bt, CTLFLAG_RD,
+ NULL, 0, sysctl_dump_cred_backtraces, "S,cred_debug_buffer", "dump credential backtrace");
+
+/* accessed by:
+ * err = sysctlbyname( "kern.cred_bt", bufp, &len, NULL, 0 );
+ */
+
+static int
+sysctl_dump_cred_backtraces( __unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req )
+{
+ int i, j;
+ int error;
+ size_t space;
+ cred_debug_buffer * bt_bufp;
+ cred_backtrace * nextp;
+
+ /* This is a readonly node. */
+ if (req->newptr != USER_ADDR_NULL) {
+ return EPERM;
+ }
+
+ if (cred_debug_buf_p == NULL) {
+ return EAGAIN;
+ }
+
+ /* calculate space needed */
+ space = sizeof(cred_debug_buf_p->next_slot);
+ space += (sizeof(cred_backtrace) * cred_debug_buf_p->next_slot);
+
+ /* they are querying us so just return the space required. */
+ if (req->oldptr == USER_ADDR_NULL) {
+ req->oldidx = space;
+ return 0;
+ }
+
+ if (space > req->oldlen) {
+ return ENOMEM;
+ }
+
+ MALLOC( bt_bufp, cred_debug_buffer *, req->oldlen, M_TEMP, M_WAITOK | M_ZERO);
+ if (bt_bufp == NULL) {
+ return ENOMEM;
+ }
+
+ /* fill in backtrace info to send back */
+ bt_bufp->next_slot = cred_debug_buf_p->next_slot;
+ space = sizeof(bt_bufp->next_slot);
+
+ nextp = &bt_bufp->stack_buffer[0];
+ for (i = 0; i < cred_debug_buf_p->next_slot; i++) {
+ nextp->depth = cred_debug_buf_p->stack_buffer[i].depth;
+ for (j = 0; j < nextp->depth; j++) {
+ nextp->stack[j] = cred_debug_buf_p->stack_buffer[i].stack[j];
}
+ space += sizeof(*nextp);
+ nextp++;
}
+ req->oldlen = space;
+ error = SYSCTL_OUT(req, bt_bufp, req->oldlen);
+ FREE(bt_bufp, M_TEMP);
+ return error;
}
+#endif /* DEBUG_CRED */
-static void kauth_cred_print(kauth_cred_t cred)
+
+/*
+ **********************************************************************
+ * The following routines will be moved to a policy_posix.c module at
+ * some future point.
+ **********************************************************************
+ */
+
+/*
+ * posix_cred_create
+ *
+ * Description: Helper function to create a kauth_cred_t credential that is
+ * initally labelled with a specific POSIX credential label
+ *
+ * Parameters: pcred The posix_cred_t to use as the initial
+ * label value
+ *
+ * Returns: (kauth_cred_t) The credential that was found in the
+ * hash or creates
+ * NULL kauth_cred_add() failed, or there was
+ * no egid specified, or we failed to
+ * attach a label to the new credential
+ *
+ * Notes: This function currently wraps kauth_cred_create(), and is the
+ * only consumer of that ill-fated function, apart from bsd_init().
+ * It exists solely to support the NFS server code creation of
+ * credentials based on the over-the-wire RPC calls containing
+ * traditional POSIX credential information being tunneled to
+ * the server host from the client machine.
+ *
+ * In the future, we hope this function goes away.
+ *
+ * In the short term, it creates a temporary credential, puts
+ * the POSIX information from NFS into it, and then calls
+ * kauth_cred_create(), as an internal implementation detail.
+ *
+ * If we have to keep it around in the medium term, it will
+ * create a new kauth_cred_t, then label it with a POSIX label
+ * corresponding to the contents of the kauth_cred_t. If the
+ * policy_posix MACF module is not loaded, it will instead
+ * substitute a posix_cred_t which GRANTS all access (effectively
+ * a "root" credential) in order to not prevent NFS from working
+ * in the case that we are not supporting POSIX credentials.
+ */
+kauth_cred_t
+posix_cred_create(posix_cred_t pcred)
{
- int i;
-
- printf("0x%02X - refs %d uids %d %d %d ", cred, cred->cr_ref, cred->cr_uid, cred->cr_ruid, cred->cr_svuid);
- printf("group count %d gids ", cred->cr_ngroups);
- for (i = 0; i < NGROUPS; i++) {
- printf("%d ", cred->cr_groups[i]);
+ struct ucred temp_cred;
+
+ bzero(&temp_cred, sizeof(temp_cred));
+ temp_cred.cr_posix = *pcred;
+
+ return kauth_cred_create(&temp_cred);
+}
+
+
+/*
+ * posix_cred_get
+ *
+ * Description: Given a kauth_cred_t, return the POSIX credential label, if
+ * any, which is associated with it.
+ *
+ * Parameters: cred The credential to obtain the label from
+ *
+ * Returns: posix_cred_t The POSIX credential label
+ *
+ * Notes: In the event that the policy_posix MACF module IS NOT loaded,
+ * this function will return a pointer to a posix_cred_t which
+ * GRANTS all access (effectively, a "root" credential). This is
+ * necessary to support legacy code which insists on tightly
+ * integrating POSIX credentials into its APIs, including, but
+ * not limited to, System V IPC mechanisms, POSIX IPC mechanisms,
+ * NFSv3, signals, dtrace, and a large number of kauth routines
+ * used to implement POSIX permissions related system calls.
+ *
+ * In the event that the policy_posix MACF module IS loaded, and
+ * there is no POSIX label on the kauth_cred_t credential, this
+ * function will return a pointer to a posix_cred_t which DENIES
+ * all access (effectively, a "deny rights granted by POSIX"
+ * credential). This is necessary to support the concept of a
+ * transiently loaded POSIX policy, or kauth_cred_t credentials
+ * which can not be used in conjunctions with POSIX permissions
+ * checks.
+ *
+ * This function currently returns the address of the cr_posix
+ * field of the supplied kauth_cred_t credential, and as such
+ * currently can not fail. In the future, this will not be the
+ * case.
+ */
+posix_cred_t
+posix_cred_get(kauth_cred_t cred)
+{
+ return &cred->cr_posix;
+}
+
+
+/*
+ * posix_cred_label
+ *
+ * Description: Label a kauth_cred_t with a POSIX credential label
+ *
+ * Parameters: cred The credential to label
+ * pcred The POSIX credential t label it with
+ *
+ * Returns: (void)
+ *
+ * Notes: This function is currently void in order to permit it to fit
+ * in with the current MACF framework label methods which allow
+ * labeling to fail silently. This is like acceptable for
+ * mandatory access controls, but not for POSIX, since those
+ * access controls are advisory. We will need to consider a
+ * return value in a future version of the MACF API.
+ *
+ * This operation currently cannot fail, as currently the POSIX
+ * credential is a subfield of the kauth_cred_t (ucred), which
+ * MUST be valid. In the future, this will not be the case.
+ */
+void
+posix_cred_label(kauth_cred_t cred, posix_cred_t pcred)
+{
+ cred->cr_posix = *pcred; /* structure assign for now */
+}
+
+
+/*
+ * posix_cred_access
+ *
+ * Description: Perform a POSIX access check for a protected object
+ *
+ * Parameters: cred The credential to check
+ * object_uid The POSIX UID of the protected object
+ * object_gid The POSIX GID of the protected object
+ * object_mode The POSIX mode of the protected object
+ * mode_req The requested POSIX access rights
+ *
+ * Returns 0 Access is granted
+ * EACCES Access is denied
+ *
+ * Notes: This code optimizes the case where the world and group rights
+ * would both grant the requested rights to avoid making a group
+ * membership query. This is a big performance win in the case
+ * where this is true.
+ */
+int
+posix_cred_access(kauth_cred_t cred, id_t object_uid, id_t object_gid, mode_t object_mode, mode_t mode_req)
+{
+ int is_member;
+ mode_t mode_owner = (object_mode & S_IRWXU);
+ mode_t mode_group = (object_mode & S_IRWXG) << 3;
+ mode_t mode_world = (object_mode & S_IRWXO) << 6;
+
+ /*
+ * Check first for owner rights
+ */
+ if (kauth_cred_getuid(cred) == object_uid && (mode_req & mode_owner) == mode_req) {
+ return 0;
+ }
+
+ /*
+ * Combined group and world rights check, if we don't have owner rights
+ *
+ * OPTIMIZED: If group and world rights would grant the same bits, and
+ * they set of requested bits is in both, then we can simply check the
+ * world rights, avoiding a group membership check, which is expensive.
+ */
+ if ((mode_req & mode_group & mode_world) == mode_req) {
+ return 0;
+ } else {
+ /*
+ * NON-OPTIMIZED: requires group membership check.
+ */
+ if ((mode_req & mode_group) != mode_req) {
+ /*
+ * exclusion group : treat errors as "is a member"
+ *
+ * NON-OPTIMIZED: +group would deny; must check group
+ */
+ if (!kauth_cred_ismember_gid(cred, object_gid, &is_member) && is_member) {
+ /*
+ * DENY: +group denies
+ */
+ return EACCES;
+ } else {
+ if ((mode_req & mode_world) != mode_req) {
+ /*
+ * DENY: both -group & world would deny
+ */
+ return EACCES;
+ } else {
+ /*
+ * ALLOW: allowed by -group and +world
+ */
+ return 0;
+ }
+ }
+ } else {
+ /*
+ * inclusion group; treat errors as "not a member"
+ *
+ * NON-OPTIMIZED: +group allows, world denies; must
+ * check group
+ */
+ if (!kauth_cred_ismember_gid(cred, object_gid, &is_member) && is_member) {
+ /*
+ * ALLOW: allowed by +group
+ */
+ return 0;
+ } else {
+ if ((mode_req & mode_world) != mode_req) {
+ /*
+ * DENY: both -group & world would deny
+ */
+ return EACCES;
+ } else {
+ /*
+ * ALLOW: allowed by -group and +world
+ */
+ return 0;
+ }
+ }
+ }
}
- printf("%d %d %d ", cred->cr_rgid, cred->cr_svgid, cred->cr_gmuid);
- printf("auditinfo %d %d %d %d %d %d ",
- cred->cr_au.ai_auid, cred->cr_au.ai_mask.am_success, cred->cr_au.ai_mask.am_failure,
- cred->cr_au.ai_termid.port, cred->cr_au.ai_termid.machine, cred->cr_au.ai_asid);
-
}
-#endif
projects / apple / xnu.git / blobdiff