X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/ff6e181ae92fc6f1e89841290f461d1f2f9badd9..e2fac8b15b12a7979f72090454d850e612fc5b13:/bsd/kern/kern_authorization.c diff --git a/bsd/kern/kern_authorization.c b/bsd/kern/kern_authorization.c index e7410c57b..b65a828c2 100644 --- a/bsd/kern/kern_authorization.c +++ b/bsd/kern/kern_authorization.c @@ -1,14 +1,19 @@ /* - * Copyright (c) 2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2004-2007 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @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 - * compliance with the License. Please obtain a copy of the License at - * http://www.opensource.apple.com/apsl/ and read it before using this - * file. + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * 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 @@ -18,7 +23,7 @@ * Please see the License for the specific language governing rights and * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -112,7 +117,7 @@ struct kauth_scope { static TAILQ_HEAD(,kauth_scope) kauth_scopes; static int kauth_add_callback_to_scope(kauth_scope_t sp, kauth_listener_t klp); -static void kauth_scope_init(void); +static void kauth_scope_init(void) __attribute__((section("__TEXT, initcode"))); static kauth_scope_t kauth_alloc_scope(const char *identifier, kauth_scope_callback_t callback, void *idata); static kauth_listener_t kauth_alloc_listener(const char *identifier, kauth_scope_callback_t callback, void *idata); #if 0 @@ -127,7 +132,7 @@ static int kauth_authorize_generic_callback(kauth_cred_t _credential, void *_ida uintptr_t arg0, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3); kauth_scope_t kauth_scope_fileop; -extern int cansignal(struct proc *, kauth_cred_t, struct proc *, int); +extern int cansignal(struct proc *, kauth_cred_t, struct proc *, int, int); extern char * get_pathbuff(void); extern void release_pathbuff(char *path); @@ -223,7 +228,8 @@ kauth_register_scope(const char *identifier, kauth_scope_callback_t callback, vo KAUTH_SCOPELOCK(); TAILQ_FOREACH(tsp, &kauth_scopes, ks_link) { /* duplicate! */ - if (strcmp(tsp->ks_identifier, identifier) == 0) { + if (strncmp(tsp->ks_identifier, identifier, + strlen(tsp->ks_identifier) + 1) == 0) { KAUTH_SCOPEUNLOCK(); FREE(sp, M_KAUTH); return(NULL); @@ -239,7 +245,8 @@ kauth_register_scope(const char *identifier, kauth_scope_callback_t callback, vo */ restart: TAILQ_FOREACH(klp, &kauth_dangling_listeners, kl_link) { - if (strcmp(klp->kl_identifier, sp->ks_identifier) == 0) { + if (strncmp(klp->kl_identifier, sp->ks_identifier, + strlen(klp->kl_identifier) + 1) == 0) { /* found a match on the dangling listener list. add it to the * the active scope. */ @@ -302,7 +309,8 @@ kauth_listen_scope(const char *identifier, kauth_scope_callback_t callback, void */ KAUTH_SCOPELOCK(); TAILQ_FOREACH(sp, &kauth_scopes, ks_link) { - if (strcmp(sp->ks_identifier, identifier) == 0) { + if (strncmp(sp->ks_identifier, identifier, + strlen(sp->ks_identifier) + 1) == 0) { /* scope exists, add it to scope listener table */ if (kauth_add_callback_to_scope(sp, klp) == 0) { KAUTH_SCOPEUNLOCK(); @@ -377,6 +385,12 @@ kauth_unlisten_scope(kauth_listener_t listener) /* * Authorization requests. + * + * Returns: 0 Success + * EPERM Operation not permitted + * + * Imputed: *arg3, modified Callback return - depends on callback + * modification of *arg3, if any */ int kauth_authorize_action(kauth_scope_t scope, kauth_cred_t credential, kauth_action_t action, @@ -468,7 +482,7 @@ kauth_authorize_process_callback(kauth_cred_t credential, __unused void *idata, /* arg0 - process to signal * arg1 - signal to send the process */ - if (cansignal(current_proc(), credential, (struct proc *)arg0, (int)arg1)) + if (cansignal(current_proc(), credential, (struct proc *)arg0, (int)arg1, 0)) return(KAUTH_RESULT_ALLOW); break; case KAUTH_PROCESS_CANTRACE: @@ -612,6 +626,7 @@ kauth_acl_evaluate(kauth_cred_t cred, kauth_acl_eval_t eval) } eval->ae_residual = eval->ae_requested; + eval->ae_found_deny = FALSE; /* * Get our guid for comparison purposes. @@ -657,6 +672,7 @@ kauth_acl_evaluate(kauth_cred_t cred, kauth_acl_eval_t eval) case KAUTH_ACE_DENY: if (!(eval->ae_requested & rights)) continue; + eval->ae_found_deny = TRUE; break; default: /* we don't recognise this ACE, skip it */ @@ -766,9 +782,13 @@ kauth_acl_inherit(vnode_t dvp, kauth_acl_t initial, kauth_acl_t *product, int is kauth_acl_t inherit, result; /* - * Fetch the ACL from the directory. This should never fail. Note that we don't - * manage inheritance when the remote server is doing authorization; we just - * want to compose the umask-ACL and any initial ACL. + * Fetch the ACL from the directory. This should never fail. + * Note that we don't manage inheritance when the remote server is + * doing authorization, since this means server enforcement of + * inheritance semantics; we just want to compose the initial + * ACL and any inherited ACE entries from the container object. + * + * XXX TODO: wants a "umask ACL" from the process. */ inherit = NULL; if ((dvp != NULL) && !vfs_authopaque(vnode_mount(dvp))) { @@ -783,7 +803,8 @@ kauth_acl_inherit(vnode_t dvp, kauth_acl_t initial, kauth_acl_t *product, int is } /* - * Compute the number of entries in the result ACL by scanning the input lists. + * Compute the number of entries in the result ACL by scanning the + * input lists. */ entries = 0; if (inherit != NULL) { @@ -794,16 +815,23 @@ kauth_acl_inherit(vnode_t dvp, kauth_acl_t initial, kauth_acl_t *product, int is } if (initial == NULL) { - /* XXX 3634665 TODO: fetch umask ACL from the process, set in initial */ + /* + * XXX 3634665 TODO: if the initial ACL is not specfied by + * XXX the caller, fetch the umask ACL from the process, + * and use it in place of "initial". + */ } if (initial != NULL) { - entries += initial->acl_entrycount; + if (initial->acl_entrycount != KAUTH_FILESEC_NOACL) + entries += initial->acl_entrycount; + else + initial = NULL; } /* * If there is no initial ACL, and no inheritable entries, the - * object should have no ACL at all. + * object should be created with no ACL at all. * Note that this differs from the case where the initial ACL * is empty, in which case the object must also have an empty ACL. */ @@ -817,7 +845,7 @@ kauth_acl_inherit(vnode_t dvp, kauth_acl_t initial, kauth_acl_t *product, int is * Allocate the result buffer. */ if ((result = kauth_acl_alloc(entries)) == NULL) { - KAUTH_DEBUG(" ERROR - could not allocate %d-entry result buffer for inherited ACL"); + KAUTH_DEBUG(" ERROR - could not allocate %d-entry result buffer for inherited ACL", entries); error = ENOMEM; goto out; } @@ -835,14 +863,27 @@ kauth_acl_inherit(vnode_t dvp, kauth_acl_t initial, kauth_acl_t *product, int is } if (inherit != NULL) { for (i = 0; i < inherit->acl_entrycount; i++) { - /* inherit onto this object? */ + /* + * Inherit onto this object? We inherit only if + * the target object is a container object and the + * KAUTH_ACE_DIRECTORY_INHERIT bit is set, OR if + * if the target object is not a container, and + * the KAUTH_ACE_FILE_INHERIT bit is set. + */ if (inherit->acl_ace[i].ace_flags & (isdir ? KAUTH_ACE_DIRECTORY_INHERIT : KAUTH_ACE_FILE_INHERIT)) { result->acl_ace[index] = inherit->acl_ace[i]; result->acl_ace[index].ace_flags |= KAUTH_ACE_INHERITED; - /* don't re-inherit? */ - if (result->acl_ace[index].ace_flags & KAUTH_ACE_LIMIT_INHERIT) + /* + * We do not re-inherit inheritance flags + * if the ACE from the container has a + * KAUTH_ACE_LIMIT_INHERIT, OR if the new + * object is not itself a container (since + * inheritance is always container-based). + */ + if ((result->acl_ace[index].ace_flags & KAUTH_ACE_LIMIT_INHERIT) || !isdir) { result->acl_ace[index].ace_flags &= - ~(KAUTH_ACE_DIRECTORY_INHERIT | KAUTH_ACE_FILE_INHERIT | KAUTH_ACE_LIMIT_INHERIT); + ~(KAUTH_ACE_INHERIT_CONTROL_FLAGS); + } index++; } } @@ -859,14 +900,32 @@ out: /* * Optimistically copy in a kauth_filesec structure + * * Parameters: xsecurity user space kauth_filesec_t - * xsecdstpp pointer to kauth_filesec_t + * xsecdstpp pointer to kauth_filesec_t to be + * modified to contain the contain a + * pointer to an allocated copy of the + * user space argument + * + * Returns: 0 Success + * ENOMEM Insufficient memory for the copy. + * EINVAL The user space data was invalid, or + * there were too many ACE entries. + * EFAULT The user space address was invalid; + * this may mean 'fsec_entrycount' in + * the user copy is corrupt/incorrect. * - * Returns: 0 on success, EINVAL or EFAULT depending on failure mode. - * Modifies: xsecdestpp, which contains a pointer to an allocated - * and copied-in kauth_filesec_t + * Implicit returns: xsecdestpp, modified (only if successful!) + * + * Notes: The returned kauth_filesec_t is in host byte order + * + * The caller is responsible for freeing the returned + * kauth_filesec_t in the success case using the function + * kauth_filesec_free() + * + * Our largest initial guess is 32; this needs to move to + * a manifest constant in . */ - int kauth_copyinfilesec(user_addr_t xsecurity, kauth_filesec_t *xsecdestpp) { @@ -914,6 +973,7 @@ restart: if ((fsec->fsec_entrycount != KAUTH_FILESEC_NOACL) && (fsec->fsec_entrycount > count)) { if (fsec->fsec_entrycount > KAUTH_ACL_MAX_ENTRIES) { + /* XXX This should be E2BIG */ error = EINVAL; goto out; } @@ -933,7 +993,23 @@ out: } /* - * Allocate a filesec structure. + * Allocate a block of memory containing a filesec structure, immediately + * followed by 'count' kauth_ace structures. + * + * Parameters: count Number of kauth_ace structures needed + * + * Returns: !NULL A pointer to the allocated block + * NULL Invalid 'count' or insufficient memory + * + * Notes: Returned memory area assumes that the structures are packed + * densely, so this function may only be used by code that also + * assumes no padding following structures. + * + * The returned structure must be freed by the caller using the + * function kauth_filesec_free(), in case we decide to use an + * allocation mechanism that is aware of the object size at some + * point, since the object size is only available by introspecting + * the object itself. */ kauth_filesec_t kauth_filesec_alloc(int count) @@ -955,6 +1031,18 @@ kauth_filesec_alloc(int count) return(fsp); } +/* + * Free a kauth_filesec_t that was previous allocated, either by a direct + * call to kauth_filesec_alloc() or by calling a function that calls it. + * + * Parameters: fsp kauth_filesec_t to free + * + * Returns: (void) + * + * Notes: The kauth_filesec_t to be freed is assumed to be in host + * byte order so that this function can introspect it in the + * future to determine its size, if necesssary. + */ void kauth_filesec_free(kauth_filesec_t fsp) { @@ -967,6 +1055,73 @@ kauth_filesec_free(kauth_filesec_t fsp) FREE(fsp, M_KAUTH); } +/* + * Set the endianness of a filesec and an ACL; if 'acl' is NULL, use the + * ACL interior to 'fsec' instead. If the endianness doesn't change, then + * this function will have no effect. + * + * Parameters: kendian The endianness to set; this is either + * KAUTH_ENDIAN_HOST or KAUTH_ENDIAN_DISK. + * fsec The filesec to convert. + * acl The ACL to convert (optional) + * + * Returns: (void) + * + * Notes: We use ntohl() because it has a transitive property on Intel + * machines and no effect on PPC mancines. This guarantees us + * that the swapping only occurs if the endiannes is wrong. + */ +void +kauth_filesec_acl_setendian(int kendian, kauth_filesec_t fsec, kauth_acl_t acl) +{ + uint32_t compare_magic = KAUTH_FILESEC_MAGIC; + uint32_t invert_magic = ntohl(KAUTH_FILESEC_MAGIC); + uint32_t compare_acl_entrycount; + uint32_t i; + + if (compare_magic == invert_magic) + return; + + /* If no ACL, use ACL interior to 'fsec' instead */ + if (acl == NULL) + acl = &fsec->fsec_acl; + + compare_acl_entrycount = acl->acl_entrycount; + + /* + * Only convert what needs to be converted, and only if the arguments + * are valid. The following switch and tests effectively reject + * conversions on invalid magic numbers as a desirable side effect. + */ + switch(kendian) { + case KAUTH_ENDIAN_HOST: /* not in host, convert to host */ + if (fsec->fsec_magic != invert_magic) + return; + /* acl_entrycount is byteswapped */ + compare_acl_entrycount = ntohl(acl->acl_entrycount); + break; + case KAUTH_ENDIAN_DISK: /* not in disk, convert to disk */ + if (fsec->fsec_magic != compare_magic) + return; + break; + default: /* bad argument */ + return; + } + + /* We are go for conversion */ + fsec->fsec_magic = ntohl(fsec->fsec_magic); + acl->acl_entrycount = ntohl(acl->acl_entrycount); + if (compare_acl_entrycount != KAUTH_FILESEC_NOACL) { + acl->acl_flags = ntohl(acl->acl_flags); + + /* swap ACE rights and flags */ + for (i = 0; i < compare_acl_entrycount; i++) { + acl->acl_ace[i].ace_flags = ntohl(acl->acl_ace[i].ace_flags); + acl->acl_ace[i].ace_rights = ntohl(acl->acl_ace[i].ace_rights); + } + } + } + /* * Allocate an ACL buffer.