/*
- * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/proc_internal.h>
+#include <sys/kauth.h>
#include <sys/systm.h>
+#include <sys/sysproto.h>
#include <security/audit/audit.h>
+#include <pexpert/pexpert.h>
-/*
-struct sysctl_oid_list sysctl__debug_children;
-struct sysctl_oid_list sysctl__kern_children;
-struct sysctl_oid_list sysctl__net_children;
-struct sysctl_oid_list sysctl__sysctl_children;
-*/
-
+lck_grp_t * sysctl_lock_group = NULL;
lck_rw_t * sysctl_geometry_lock = NULL;
-
-static void
-sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i);
-
-
+lck_mtx_t * sysctl_unlocked_node_lock = NULL;
/*
- * Locking and stats
+ * Conditionally allow dtrace to see these functions for debugging purposes.
*/
-static struct sysctl_lock memlock;
-
-/*
- * XXX this does not belong here
- */
-static funnel_t *
-spl_kernel_funnel(void)
-{
- funnel_t *cfunnel;
-
- cfunnel = thread_funnel_get();
- if (cfunnel != kernel_flock) {
- if (cfunnel != NULL)
- thread_funnel_set(cfunnel, FALSE);
- thread_funnel_set(kernel_flock, TRUE);
- }
- return(cfunnel);
-}
-
-static void
-splx_kernel_funnel(funnel_t *saved)
-{
- if (saved != kernel_flock) {
- thread_funnel_set(kernel_flock, FALSE);
- if (saved != NULL)
- thread_funnel_set(saved, TRUE);
- }
-}
+#ifdef STATIC
+#undef STATIC
+#endif
+#if 0
+#define STATIC
+#else
+#define STATIC static
+#endif
-static int sysctl_root SYSCTL_HANDLER_ARGS;
+/* forward declarations of static functions */
+STATIC void sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i);
+STATIC int sysctl_sysctl_debug(struct sysctl_oid *oidp, void *arg1,
+ int arg2, struct sysctl_req *req);
+STATIC int sysctl_sysctl_name(struct sysctl_oid *oidp, void *arg1,
+ int arg2, struct sysctl_req *req);
+STATIC int sysctl_sysctl_next_ls (struct sysctl_oid_list *lsp,
+ int *name, u_int namelen, int *next, int *len, int level,
+ struct sysctl_oid **oidpp);
+STATIC int sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l);
+STATIC int sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l);
+STATIC int name2oid (char *name, int *oid, u_int *len);
+STATIC int sysctl_sysctl_name2oid(struct sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req);
+STATIC int sysctl_sysctl_next(struct sysctl_oid *oidp, void *arg1, int arg2,
+ struct sysctl_req *req);
+STATIC int sysctl_sysctl_oidfmt(struct sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req);
+STATIC int sysctl_old_user(struct sysctl_req *req, const void *p, size_t l);
+STATIC int sysctl_new_user(struct sysctl_req *req, void *p, size_t l);
+
+STATIC void sysctl_create_user_req(struct sysctl_req *req, struct proc *p, user_addr_t oldp,
+ size_t oldlen, user_addr_t newp, size_t newlen);
+STATIC int sysctl_root(boolean_t from_kernel, boolean_t string_is_canonical, char *namestring, size_t namestringlen, int *name, u_int namelen, struct sysctl_req *req);
+
+int kernel_sysctl(struct proc *p, int *name, u_int namelen, void *old, size_t *oldlenp, void *new, size_t newlen);
+int kernel_sysctlbyname(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen);
+int userland_sysctl(boolean_t string_is_canonical,
+ char *namestring, size_t namestringlen,
+ int *name, u_int namelen, struct sysctl_req *req,
+ size_t *retval);
struct sysctl_oid_list sysctl__children; /* root list */
* Order by number in each list.
*/
-void sysctl_register_oid(struct sysctl_oid *oidp)
+void
+sysctl_register_oid(struct sysctl_oid *new_oidp)
{
- struct sysctl_oid_list *parent = oidp->oid_parent;
+ struct sysctl_oid *oidp = NULL;
+ struct sysctl_oid_list *parent = new_oidp->oid_parent;
struct sysctl_oid *p;
struct sysctl_oid *q;
int n;
- funnel_t *fnl;
-
- fnl = spl_kernel_funnel();
- if(sysctl_geometry_lock == NULL)
- {
- /* Initialise the geometry lock for reading/modifying the sysctl tree
- * This is done here because IOKit registers some sysctls before bsd_init()
- * calls sysctl_register_fixed().
+ /*
+ * The OID can be old-style (needs copy), new style without an earlier
+ * version (also needs copy), or new style with a matching version (no
+ * copy needed). Later versions are rejected (presumably, the OID
+ * structure was changed for a necessary reason).
+ */
+ if (!(new_oidp->oid_kind & CTLFLAG_OID2)) {
+ /*
+ * XXX: M_TEMP is perhaps not the most apropriate zone, as it
+ * XXX: will subject us to use-after-free by other consumers.
*/
+ MALLOC(oidp, struct sysctl_oid *, sizeof(*oidp), M_TEMP, M_WAITOK | M_ZERO);
+ if (oidp == NULL)
+ return; /* reject: no memory */
- lck_grp_t* lck_grp = lck_grp_alloc_init("sysctl", NULL);
- sysctl_geometry_lock = lck_rw_alloc_init(lck_grp, NULL);
+ /*
+ * Copy the structure only through the oid_fmt field, which
+ * is the last field in a non-OID2 OID structure.
+ *
+ * Note: We may want to set the oid_descr to the
+ * oid_name (or "") at some future date.
+ */
+ memcpy(oidp, new_oidp, offsetof(struct sysctl_oid, oid_descr));
+ } else {
+ /* It's a later version; handle the versions we know about */
+ switch (new_oidp->oid_version) {
+ case SYSCTL_OID_VERSION:
+ /* current version */
+ oidp = new_oidp;
+ break;
+ default:
+ return; /* rejects unknown version */
+ }
}
+
/* Get the write lock to modify the geometry */
lck_rw_lock_exclusive(sysctl_geometry_lock);
n = p->oid_number;
}
oidp->oid_number = n + 1;
+ /*
+ * Reflect the number in an llocated OID into the template
+ * of the caller for sysctl_unregister_oid() compares.
+ */
+ if (oidp != new_oidp)
+ new_oidp->oid_number = oidp->oid_number;
}
/*
/* Release the write lock */
lck_rw_unlock_exclusive(sysctl_geometry_lock);
-
- splx_kernel_funnel(fnl);
}
-void sysctl_unregister_oid(struct sysctl_oid *oidp)
+void
+sysctl_unregister_oid(struct sysctl_oid *oidp)
{
- funnel_t *fnl;
-
- fnl = spl_kernel_funnel();
+ struct sysctl_oid *removed_oidp = NULL; /* OID removed from tree */
+ struct sysctl_oid *old_oidp = NULL; /* OID compatibility copy */
/* Get the write lock to modify the geometry */
lck_rw_lock_exclusive(sysctl_geometry_lock);
- SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link);
+ if (!(oidp->oid_kind & CTLFLAG_OID2)) {
+ /*
+ * We're using a copy so we can get the new fields in an
+ * old structure, so we have to iterate to compare the
+ * partial structure; when we find a match, we remove it
+ * normally and free the memory.
+ */
+ SLIST_FOREACH(old_oidp, oidp->oid_parent, oid_link) {
+ if (!memcmp(&oidp->oid_number, &old_oidp->oid_number, (offsetof(struct sysctl_oid, oid_descr)-offsetof(struct sysctl_oid, oid_number)))) {
+ break;
+ }
+ }
+ if (old_oidp != NULL) {
+ SLIST_REMOVE(old_oidp->oid_parent, old_oidp, sysctl_oid, oid_link);
+ removed_oidp = old_oidp;
+ }
+ } else {
+ /* It's a later version; handle the versions we know about */
+ switch (oidp->oid_version) {
+ case SYSCTL_OID_VERSION:
+ /* We can just remove the OID directly... */
+ SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link);
+ removed_oidp = oidp;
+ break;
+ default:
+ /* XXX: Can't happen; probably tree coruption.*/
+ break; /* rejects unknown version */
+ }
+ }
+
+ /*
+ * We've removed it from the list at this point, but we don't want
+ * to return to the caller until all handler references have drained
+ * out. Doing things in this order prevent other people coming in
+ * and starting new operations against the OID node we want removed.
+ *
+ * Note: oidp could be NULL if it wasn't found.
+ */
+ while(removed_oidp && removed_oidp->oid_refcnt) {
+ lck_rw_sleep(sysctl_geometry_lock, LCK_SLEEP_EXCLUSIVE, &removed_oidp->oid_refcnt, THREAD_UNINT);
+ }
/* Release the write lock */
lck_rw_unlock_exclusive(sysctl_geometry_lock);
- splx_kernel_funnel(fnl);
+ /* If it was allocated, free it after dropping the lock */
+ if (old_oidp != NULL) {
+ FREE(old_oidp, M_TEMP);
+ }
}
/*
* Bulk-register all the oids in a linker_set.
*/
-void sysctl_register_set(const char *set)
+void
+sysctl_register_set(const char *set)
{
struct sysctl_oid **oidpp, *oidp;
}
}
-void sysctl_unregister_set(const char *set)
+void
+sysctl_unregister_set(const char *set)
{
struct sysctl_oid **oidpp, *oidp;
}
}
-
/*
- * Register the kernel's oids on startup.
+ * Exported in BSDKernel.exports, kept for binary compatibility
*/
-
+#if defined(__x86_64__)
void
-sysctl_register_all()
+sysctl_register_fixed(void)
{
- sysctl_register_set("__sysctl_set");
}
+#endif
+
+/*
+ * Register the kernel's oids on startup.
+ */
void
-sysctl_register_fixed(void)
+sysctl_early_init(void)
{
- sysctl_register_all();
+ /*
+ * Initialize the geometry lock for reading/modifying the
+ * sysctl tree. This is done here because IOKit registers
+ * some sysctl's before bsd_init() would otherwise perform
+ * subsystem initialization.
+ */
+
+ sysctl_lock_group = lck_grp_alloc_init("sysctl", NULL);
+ sysctl_geometry_lock = lck_rw_alloc_init(sysctl_lock_group, NULL);
+ sysctl_unlocked_node_lock = lck_mtx_alloc_init(sysctl_lock_group, NULL);
+
+ sysctl_register_set("__sysctl_set");
}
/*
* {0,4,...} return the kind & format info for the "..." OID.
*/
-static void
+/*
+ * sysctl_sysctl_debug_dump_node
+ *
+ * Description: Dump debug information for a given sysctl_oid_list at the
+ * given oid depth out to the kernel log, via printf
+ *
+ * Parameters: l sysctl_oid_list pointer
+ * i current node depth
+ *
+ * Returns: (void)
+ *
+ * Implicit: kernel log, modified
+ *
+ * Locks: Assumes sysctl_geometry_lock is held prior to calling
+ *
+ * Notes: This function may call itself recursively to resolve Node
+ * values, which potentially have an inferioer sysctl_oid_list
+ *
+ * This function is only callable indirectly via the function
+ * sysctl_sysctl_debug()
+ *
+ * Bugs: The node depth indentation does not work; this may be an
+ * artifact of leading space removal by the log daemon itself
+ * or some intermediate routine.
+ */
+STATIC void
sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
{
int k;
printf("%d %s ", oidp->oid_number, oidp->oid_name);
- printf("%c%c",
+ printf("%c%c%c",
+ oidp->oid_kind & CTLFLAG_LOCKED ? 'L':' ',
oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
}
}
-static int
+/*
+ * sysctl_sysctl_debug
+ *
+ * Description: This function implements the "sysctl.debug" portion of the
+ * OID space for sysctl.
+ *
+ * OID: 0, 0
+ *
+ * Parameters: __unused
+ *
+ * Returns: ENOENT
+ *
+ * Implicit: kernel log, modified
+ *
+ * Locks: Acquires and then releases a read lock on the
+ * sysctl_geometry_lock
+ */
+STATIC int
sysctl_sysctl_debug(__unused struct sysctl_oid *oidp, __unused void *arg1,
__unused int arg2, __unused struct sysctl_req *req)
{
+ lck_rw_lock_shared(sysctl_geometry_lock);
sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
+ lck_rw_done(sysctl_geometry_lock);
return ENOENT;
}
-SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
+SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD | CTLFLAG_LOCKED,
0, 0, sysctl_sysctl_debug, "-", "");
-static int
+/*
+ * sysctl_sysctl_name
+ *
+ * Description: Convert an OID into a string name; this is used by the user
+ * space sysctl() command line utility; this is done in a purely
+ * advisory capacity (e.g. to provide node names for "sysctl -A"
+ * output).
+ *
+ * OID: 0, 1
+ *
+ * Parameters: oidp __unused
+ * arg1 A pointer to the OID name list
+ * integer array, beginning at
+ * adjusted option base 2
+ * arg2 The number of elements which
+ * remain in the name array
+ *
+ * Returns: 0 Success
+ * SYSCTL_OUT:EPERM Permission denied
+ * SYSCTL_OUT:EFAULT Bad user supplied buffer
+ * SYSCTL_OUT:??? Return value from user function
+ * for SYSCTL_PROC leaf node
+ *
+ * Implict: Contents of user request buffer, modified
+ *
+ * Locks: Acquires and then releases a read lock on the
+ * sysctl_geometry_lock
+ *
+ * Notes: SPI (System Programming Interface); this is subject to change
+ * and may not be relied upon by third party applications; use
+ * a subprocess to communicate with the "sysctl" command line
+ * command instead, if you believe you need this functionality.
+ * Preferrably, use sysctlbyname() instead.
+ *
+ * Setting of the NULL termination of the output string is
+ * delayed until after the geometry lock is dropped. If there
+ * are no Entries remaining in the OID name list when this
+ * function is called, it will still write out the termination
+ * byte.
+ *
+ * This function differs from other sysctl functions in that
+ * it can not take an output buffer length of 0 to determine the
+ * space which will be required. It is suggested that the buffer
+ * length be PATH_MAX, and that authors of new sysctl's refrain
+ * from exceeding this string length.
+ */
+STATIC int
sysctl_sysctl_name(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
char tempbuf[10];
+ lck_rw_lock_shared(sysctl_geometry_lock);
while (namelen) {
if (!lsp) {
snprintf(tempbuf,sizeof(tempbuf),"%d",*name);
error = SYSCTL_OUT(req, ".", 1);
if (!error)
error = SYSCTL_OUT(req, tempbuf, strlen(tempbuf));
- if (error)
+ if (error) {
+ lck_rw_done(sysctl_geometry_lock);
return (error);
+ }
namelen--;
name++;
continue;
if (!error)
error = SYSCTL_OUT(req, oid->oid_name,
strlen(oid->oid_name));
- if (error)
+ if (error) {
+ lck_rw_done(sysctl_geometry_lock);
return (error);
+ }
namelen--;
name++;
}
lsp = lsp2;
}
+ lck_rw_done(sysctl_geometry_lock);
return (SYSCTL_OUT(req, "", 1));
}
-SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
+SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_LOCKED, sysctl_sysctl_name, "");
-static int
+/*
+ * sysctl_sysctl_next_ls
+ *
+ * Description: For a given OID name value, return the next consecutive OID
+ * name value within the geometry tree
+ *
+ * Parameters: lsp The OID list to look in
+ * name The OID name to start from
+ * namelen The length of the OID name
+ * next Pointer to new oid storage to
+ * fill in
+ * len Pointer to receive new OID
+ * length value of storage written
+ * level OID tree depth (used to compute
+ * len value)
+ * oidpp Pointer to OID list entry
+ * pointer; used to walk the list
+ * forward across recursion
+ *
+ * Returns: 0 Returning a new entry
+ * 1 End of geometry list reached
+ *
+ * Implicit: *next Modified to contain the new OID
+ * *len Modified to contain new length
+ *
+ * Locks: Assumes sysctl_geometry_lock is held prior to calling
+ *
+ * Notes: This function will not return OID values that have special
+ * handlers, since we can not tell wheter these handlers consume
+ * elements from the OID space as parameters. For this reason,
+ * we STRONGLY discourage these types of handlers
+ */
+STATIC int
sysctl_sysctl_next_ls (struct sysctl_oid_list *lsp, int *name, u_int namelen,
int *next, int *len, int level, struct sysctl_oid **oidpp)
{
return 1;
}
-static int
+/*
+ * sysctl_sysctl_next
+ *
+ * Description: This is an iterator function designed to iterate the oid tree
+ * and provide a list of OIDs for use by the user space "sysctl"
+ * command line tool
+ *
+ * OID: 0, 2
+ *
+ * Parameters: oidp __unused
+ * arg1 Pointer to start OID name
+ * arg2 Start OID name length
+ * req Pointer to user request buffer
+ *
+ * Returns: 0 Success
+ * ENOENT Reached end of OID space
+ * SYSCTL_OUT:EPERM Permission denied
+ * SYSCTL_OUT:EFAULT Bad user supplied buffer
+ * SYSCTL_OUT:??? Return value from user function
+ * for SYSCTL_PROC leaf node
+ *
+ * Implict: Contents of user request buffer, modified
+ *
+ * Locks: Acquires and then releases a read lock on the
+ * sysctl_geometry_lock
+ *
+ * Notes: SPI (System Programming Interface); this is subject to change
+ * and may not be relied upon by third party applications; use
+ * a subprocess to communicate with the "sysctl" command line
+ * command instead, if you believe you need this functionality.
+ * Preferrably, use sysctlbyname() instead.
+ *
+ * This function differs from other sysctl functions in that
+ * it can not take an output buffer length of 0 to determine the
+ * space which will be required. It is suggested that the buffer
+ * length be PATH_MAX, and that authors of new sysctl's refrain
+ * from exceeding this string length.
+ */
+STATIC int
sysctl_sysctl_next(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
struct sysctl_oid_list *lsp = &sysctl__children;
int newoid[CTL_MAXNAME];
+ lck_rw_lock_shared(sysctl_geometry_lock);
i = sysctl_sysctl_next_ls (lsp, name, namelen, newoid, &j, 1, &oid);
+ lck_rw_done(sysctl_geometry_lock);
if (i)
return ENOENT;
error = SYSCTL_OUT(req, newoid, j * sizeof (int));
return (error);
}
-SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
+SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_LOCKED, sysctl_sysctl_next, "");
-static int
-name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
+/*
+ * name2oid
+ *
+ * Description: Support function for use by sysctl_sysctl_name2oid(); looks
+ * up an OID name given a string name.
+ *
+ * Parameters: name NULL terminated string name
+ * oid Pointer to receive OID name
+ * len Pointer to receive OID length
+ * pointer value (see "Notes")
+ *
+ * Returns: 0 Success
+ * ENOENT Entry not found
+ *
+ * Implicit: *oid Modified to contain OID value
+ * *len Modified to contain OID length
+ *
+ * Locks: Assumes sysctl_geometry_lock is held prior to calling
+ */
+STATIC int
+name2oid (char *name, int *oid, u_int *len)
{
int i;
struct sysctl_oid *oidp;
(*len)++;
if (!i) {
- if (oidpp)
- *oidpp = oidp;
return (0);
}
lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
oidp = SLIST_FIRST(lsp);
+ *p = i; /* restore */
name = p+1;
for (p = name; *p && *p != '.'; p++)
;
return ENOENT;
}
-static int
+/*
+ * sysctl_sysctl_name2oid
+ *
+ * Description: Translate a string name to an OID name value; this is used by
+ * the sysctlbyname() function as well as by the "sysctl" command
+ * line command.
+ *
+ * OID: 0, 3
+ *
+ * Parameters: oidp __unused
+ * arg1 __unused
+ * arg2 __unused
+ * req Request structure
+ *
+ * Returns: ENOENT Input length too short
+ * ENAMETOOLONG Input length too long
+ * ENOMEM Could not allocate work area
+ * SYSCTL_IN/OUT:EPERM Permission denied
+ * SYSCTL_IN/OUT:EFAULT Bad user supplied buffer
+ * SYSCTL_IN/OUT:??? Return value from user function
+ * name2oid:ENOENT Not found
+ *
+ * Implicit: *req Contents of request, modified
+ *
+ * Locks: Acquires and then releases a read lock on the
+ * sysctl_geometry_lock
+ *
+ * Notes: SPI (System Programming Interface); this is subject to change
+ * and may not be relied upon by third party applications; use
+ * a subprocess to communicate with the "sysctl" command line
+ * command instead, if you believe you need this functionality.
+ * Preferrably, use sysctlbyname() instead.
+ *
+ * This function differs from other sysctl functions in that
+ * it can not take an output buffer length of 0 to determine the
+ * space which will be required. It is suggested that the buffer
+ * length be PATH_MAX, and that authors of new sysctl's refrain
+ * from exceeding this string length.
+ */
+STATIC int
sysctl_sysctl_name2oid(__unused struct sysctl_oid *oidp, __unused void *arg1,
__unused int arg2, struct sysctl_req *req)
{
char *p;
int error, oid[CTL_MAXNAME];
- int len = 0; /* set by name2oid() */
- struct sysctl_oid *op = 0;
+ u_int len = 0; /* set by name2oid() */
- if (!req->newlen)
+ if (req->newlen < 1)
return ENOENT;
if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
return (ENAMETOOLONG);
p [req->newlen] = '\0';
- error = name2oid(p, oid, &len, &op);
+ /*
+ * Note: We acquire and release the geometry lock here to
+ * avoid making name2oid needlessly complex.
+ */
+ lck_rw_lock_shared(sysctl_geometry_lock);
+ error = name2oid(p, oid, &len);
+ lck_rw_done(sysctl_geometry_lock);
FREE(p, M_TEMP);
return (error);
}
-SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_KERN, 0, 0,
+SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_KERN | CTLFLAG_LOCKED, 0, 0,
sysctl_sysctl_name2oid, "I", "");
-static int
+/*
+ * sysctl_sysctl_oidfmt
+ *
+ * Description: For a given OID name, determine the format of the data which
+ * is associated with it. This is used by the "sysctl" command
+ * line command.
+ *
+ * OID: 0, 4
+ *
+ * Parameters: oidp __unused
+ * arg1 The OID name to look up
+ * arg2 The length of the OID name
+ * req Pointer to user request buffer
+ *
+ * Returns: 0 Success
+ * EISDIR Malformed request
+ * ENOENT No such OID name
+ * SYSCTL_OUT:EPERM Permission denied
+ * SYSCTL_OUT:EFAULT Bad user supplied buffer
+ * SYSCTL_OUT:??? Return value from user function
+ *
+ * Implict: Contents of user request buffer, modified
+ *
+ * Locks: Acquires and then releases a read lock on the
+ * sysctl_geometry_lock
+ *
+ * Notes: SPI (System Programming Interface); this is subject to change
+ * and may not be relied upon by third party applications; use
+ * a subprocess to communicate with the "sysctl" command line
+ * command instead, if you believe you need this functionality.
+ *
+ * This function differs from other sysctl functions in that
+ * it can not take an output buffer length of 0 to determine the
+ * space which will be required. It is suggested that the buffer
+ * length be PATH_MAX, and that authors of new sysctl's refrain
+ * from exceeding this string length.
+ */
+STATIC int
sysctl_sysctl_oidfmt(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
- int *name = (int *) arg1, error;
+ int *name = (int *) arg1;
+ int error = ENOENT; /* default error: not found */
u_int namelen = arg2;
u_int indx;
struct sysctl_oid *oid;
struct sysctl_oid_list *lsp = &sysctl__children;
+ lck_rw_lock_shared(sysctl_geometry_lock);
oid = SLIST_FIRST(lsp);
indx = 0;
lsp = (struct sysctl_oid_list *)oid->oid_arg1;
oid = SLIST_FIRST(lsp);
} else {
- if (indx != namelen)
- return EISDIR;
+ if (indx != namelen) {
+ error = EISDIR;
+ goto err;
+ }
goto found;
}
} else {
oid = SLIST_NEXT(oid, oid_link);
}
}
- return ENOENT;
+ /* Not found */
+ goto err;
+
found:
if (!oid->oid_fmt)
- return ENOENT;
+ goto err;
error = SYSCTL_OUT(req,
&oid->oid_kind, sizeof(oid->oid_kind));
if (!error)
error = SYSCTL_OUT(req, oid->oid_fmt,
strlen(oid->oid_fmt)+1);
+err:
+ lck_rw_done(sysctl_geometry_lock);
return (error);
}
+SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD | CTLFLAG_LOCKED, sysctl_sysctl_oidfmt, "");
-SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
/*
* Default "handler" functions.
/*
* Transfer functions to/from kernel space.
*/
-static int
+STATIC int
sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
{
size_t i = 0;
return (0);
}
-static int
+STATIC int
sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
{
if (!req->newptr)
req.lock = 1;
/* make the request */
- error = sysctl_root(0, name, namelen, &req);
-
- /* unlock memory if required */
- if (req.lock == 2)
- vsunlock(req.oldptr, (user_size_t)req.oldlen, B_WRITE);
+ error = sysctl_root(TRUE, FALSE, NULL, 0, name, namelen, &req);
if (error && error != ENOMEM)
return (error);
/*
* Transfer function to/from user space.
*/
-static int
+STATIC int
sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
{
int error = 0;
return (0);
}
-static int
+STATIC int
sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
{
int error;
*/
int
-sysctl_root(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
- struct sysctl_req *req)
+sysctl_root(boolean_t from_kernel, boolean_t string_is_canonical, char *namestring, size_t namestringlen, int *name, u_int namelen, struct sysctl_req *req)
{
- int *name = (int *) arg1;
- u_int namelen = arg2;
u_int indx;
int i;
struct sysctl_oid *oid;
struct sysctl_oid_list *lsp = &sysctl__children;
int error;
- funnel_t *fnl = NULL;
- boolean_t funnel_held = FALSE;
+ boolean_t unlocked_node_found = FALSE;
+ boolean_t namestring_started = FALSE;
/* Get the read lock on the geometry */
lck_rw_lock_shared(sysctl_geometry_lock);
+ if (string_is_canonical) {
+ /* namestring is actually canonical, name/namelen needs to be populated */
+ error = name2oid(namestring, name, &namelen);
+ if (error) {
+ goto err;
+ }
+ }
+
oid = SLIST_FIRST(lsp);
indx = 0;
while (oid && indx < CTL_MAXNAME) {
if (oid->oid_number == name[indx]) {
+
+ if (!from_kernel && !string_is_canonical) {
+ if (namestring_started) {
+ if (strlcat(namestring, ".", namestringlen) >= namestringlen) {
+ error = ENAMETOOLONG;
+ goto err;
+ }
+ }
+
+ if (strlcat(namestring, oid->oid_name, namestringlen) >= namestringlen) {
+ error = ENAMETOOLONG;
+ goto err;
+ }
+ namestring_started = TRUE;
+ }
+
indx++;
if (!(oid->oid_kind & CTLFLAG_LOCKED))
{
- funnel_held = TRUE;
+ unlocked_node_found = TRUE;
}
if (oid->oid_kind & CTLFLAG_NOLOCK)
req->lock = 0;
+ /*
+ * For SYSCTL_PROC() functions which are for sysctl's
+ * which have parameters at the end of their OID
+ * space, you need to OR CTLTYPE_NODE into their
+ * access value.
+ *
+ * NOTE: For binary backward compatibility ONLY! Do
+ * NOT add new sysctl's that do this! Existing
+ * sysctl's which do this will eventually have
+ * compatibility code in user space, and this method
+ * will become unsupported.
+ */
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (oid->oid_handler)
goto found;
error = ENOENT;
goto err;
found:
+
+ /*
+ * indx is the index of the first remaining OID name,
+ * for sysctls that take them as arguments
+ */
+ if (!from_kernel && !string_is_canonical && (indx < namelen)) {
+ char tempbuf[10];
+ u_int indx2;
+
+ for (indx2 = indx; indx2 < namelen; indx2++) {
+ snprintf(tempbuf, sizeof(tempbuf), "%d",name[indx2]);
+
+ if (namestring_started) {
+ if (strlcat(namestring, ".", namestringlen) >= namestringlen) {
+ error = ENAMETOOLONG;
+ goto err;
+ }
+ }
+
+ if (strlcat(namestring, tempbuf, namestringlen) >= namestringlen) {
+ error = ENAMETOOLONG;
+ goto err;
+ }
+ namestring_started = TRUE;
+ }
+ }
+
/* If writing isn't allowed */
if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) ||
((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0))) {
/*
* If we're inside the kernel, the OID must be marked as kernel-valid.
- * XXX This mechanism for testing is bad.
*/
- if ((req->oldfunc == sysctl_old_kernel) && !(oid->oid_kind & CTLFLAG_KERN))
+ if (from_kernel && !(oid->oid_kind & CTLFLAG_KERN))
{
error = (EPERM);
goto err;
}
- /* Most likely only root can write */
+ /*
+ * This is where legacy enforcement of permissions occurs. If the
+ * flag does not say CTLFLAG_ANYBODY, then we prohibit anyone but
+ * root from writing new values down. If local enforcement happens
+ * at the leaf node, then it needs to be set as CTLFLAG_ANYBODY. In
+ * addition, if the leaf node is set this way, then in order to do
+ * specific enforcement, it has to be of type SYSCTL_PROC.
+ */
if (!(oid->oid_kind & CTLFLAG_ANYBODY) &&
req->newptr && req->p &&
(error = proc_suser(req->p)))
goto err;
}
- if (funnel_held)
+ /*
+ * Reference the OID and drop the geometry lock; this prevents the
+ * OID from being deleted out from under the handler call, but does
+ * not prevent other calls into handlers or calls to manage the
+ * geometry elsewhere from blocking...
+ */
+ OSAddAtomic(1, &oid->oid_refcnt);
+
+ lck_rw_done(sysctl_geometry_lock);
+
+#if CONFIG_MACF
+ if (!from_kernel) {
+ error = mac_system_check_sysctlbyname(kauth_cred_get(),
+ namestring,
+ name,
+ namelen,
+ req->oldptr,
+ req->oldlen,
+ req->newptr,
+ req->newlen);
+ if (error)
+ goto dropref;
+ }
+#endif
+
+ /*
+ * ...however, we still have to grab the mutex for those calls which
+ * may be into code whose reentrancy is protected by it.
+ */
+ if (unlocked_node_found)
{
- fnl = spl_kernel_funnel();
- MEMLOCK_LOCK();
+ lck_mtx_lock(sysctl_unlocked_node_lock);
}
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
}
error = i;
- if (funnel_held)
+ if (unlocked_node_found)
{
- MEMLOCK_UNLOCK();
- splx_kernel_funnel(fnl);
+ lck_mtx_unlock(sysctl_unlocked_node_lock);
}
+#if CONFIG_MACF
+ /* only used from another CONFIG_MACF block */
+dropref:
+#endif
+
+ /*
+ * This is tricky... we re-grab the geometry lock in order to drop
+ * the reference and wake on the address; since the geometry
+ * lock is a reader/writer lock rather than a mutex, we have to
+ * wake on all apparent 1->0 transitions. This abuses the drop
+ * after the reference decrement in order to wake any lck_rw_sleep()
+ * in progress in sysctl_unregister_oid() that slept because of a
+ * non-zero reference count.
+ *
+ * Note: OSAddAtomic() is defined to return the previous value;
+ * we use this and the fact that the lock itself is a
+ * barrier to avoid waking every time through on "hot"
+ * OIDs.
+ */
+ lck_rw_lock_shared(sysctl_geometry_lock);
+ if (OSAddAtomic(-1, &oid->oid_refcnt) == 1)
+ wakeup(&oid->oid_refcnt);
+
err:
lck_rw_done(sysctl_geometry_lock);
return (error);
}
-#ifndef _SYS_SYSPROTO_H_
-struct sysctl_args {
- int *name;
- u_int namelen;
- void *old;
- size_t *oldlenp;
- void *new;
- size_t newlen;
-};
-#endif
+void sysctl_create_user_req(struct sysctl_req *req, struct proc *p, user_addr_t oldp,
+ size_t oldlen, user_addr_t newp, size_t newlen)
+{
+ bzero(req, sizeof(*req));
+
+ req->p = p;
+
+ req->oldlen = oldlen;
+ req->oldptr = oldp;
+
+ if (newlen) {
+ req->newlen = newlen;
+ req->newptr = newp;
+ }
+
+ req->oldfunc = sysctl_old_user;
+ req->newfunc = sysctl_new_user;
+ req->lock = 1;
+
+ return;
+}
int
-/* __sysctl(struct proc *p, struct sysctl_args *uap) */
-new_sysctl(struct proc *p, struct sysctl_args *uap)
+sysctl(proc_t p, struct sysctl_args *uap, __unused int32_t *retval)
{
- int error, i, name[CTL_MAXNAME];
- size_t j;
-
+ int error;
+ size_t oldlen = 0, newlen;
+ int name[CTL_MAXNAME];
+ struct sysctl_req req;
+ char *namestring;
+ size_t namestringlen = MAXPATHLEN;
+
+ /*
+ * all top-level sysctl names are non-terminal
+ */
if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
return (EINVAL);
+ error = copyin(uap->name, &name[0], uap->namelen * sizeof(int));
+ if (error)
+ return (error);
+
+ AUDIT_ARG(ctlname, name, uap->namelen);
+
+ if (uap->newlen > SIZE_T_MAX)
+ return (EINVAL);
+ newlen = (size_t)uap->newlen;
+
+ if (uap->oldlenp != USER_ADDR_NULL) {
+ uint64_t oldlen64 = fuulong(uap->oldlenp);
+
+ /*
+ * If more than 4G, clamp to 4G
+ */
+ if (oldlen64 > SIZE_T_MAX)
+ oldlen = SIZE_T_MAX;
+ else
+ oldlen = (size_t)oldlen64;
+ }
+
+ sysctl_create_user_req(&req, p, uap->old, oldlen, uap->new, newlen);
+
+ /* Guess that longest length for the passed-in MIB, if we can be more aggressive than MAXPATHLEN */
+ if (uap->namelen == 2) {
+ if (name[0] == CTL_KERN && name[1] < KERN_MAXID) {
+ namestringlen = 32; /* "kern.speculative_reads_disabled" */
+ } else if (name[0] == CTL_HW && name[1] < HW_MAXID) {
+ namestringlen = 32; /* "hw.cachelinesize_compat" */
+ }
+ }
+
+ MALLOC(namestring, char *, namestringlen, M_TEMP, M_WAITOK);
+ if (!namestring) {
+ oldlen = 0;
+ goto err;
+ }
- error = copyin(CAST_USER_ADDR_T(uap->name), &name, uap->namelen * sizeof(int));
- if (error)
+ error = userland_sysctl(FALSE, namestring, namestringlen, name, uap->namelen, &req, &oldlen);
+
+ FREE(namestring, M_TEMP);
+
+ if ((error) && (error != ENOMEM))
return (error);
+
+err:
+ if (uap->oldlenp != USER_ADDR_NULL)
+ error = suulong(uap->oldlenp, oldlen);
+
+ return (error);
+}
- error = userland_sysctl(p, name, uap->namelen,
- CAST_USER_ADDR_T(uap->old), uap->oldlenp,
- CAST_USER_ADDR_T(uap->new), uap->newlen, &j);
- if (error && error != ENOMEM)
+int
+sysctlbyname(proc_t p, struct sysctlbyname_args *uap, __unused int32_t *retval)
+{
+ int error;
+ size_t oldlen = 0, newlen;
+ char *name;
+ size_t namelen = 0;
+ struct sysctl_req req;
+ int oid[CTL_MAXNAME];
+
+ if (uap->namelen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
+ return (ENAMETOOLONG);
+ namelen = (size_t)uap->namelen;
+
+ MALLOC(name, char *, namelen+1, M_TEMP, M_WAITOK);
+ if (!name)
+ return ENOMEM;
+
+ error = copyin(uap->name, name, namelen);
+ if (error) {
+ FREE(name, M_TEMP);
return (error);
- if (uap->oldlenp) {
- i = copyout(&j, CAST_USER_ADDR_T(uap->oldlenp), sizeof(j));
- if (i)
- return (i);
}
+ name[namelen] = '\0';
+
+ /* XXX
+ * AUDIT_ARG(ctlname, name, uap->namelen);
+ */
+
+ if (uap->newlen > SIZE_T_MAX) {
+ FREE(name, M_TEMP);
+ return (EINVAL);
+ }
+ newlen = (size_t)uap->newlen;
+
+ if (uap->oldlenp != USER_ADDR_NULL) {
+ uint64_t oldlen64 = fuulong(uap->oldlenp);
+
+ /*
+ * If more than 4G, clamp to 4G
+ */
+ if (oldlen64 > SIZE_T_MAX)
+ oldlen = SIZE_T_MAX;
+ else
+ oldlen = (size_t)oldlen64;
+ }
+
+ sysctl_create_user_req(&req, p, uap->old, oldlen, uap->new, newlen);
+
+ error = userland_sysctl(TRUE, name, namelen+1, oid, CTL_MAXNAME, &req, &oldlen);
+
+ FREE(name, M_TEMP);
+
+ if ((error) && (error != ENOMEM))
+ return (error);
+
+ if (uap->oldlenp != USER_ADDR_NULL)
+ error = suulong(uap->oldlenp, oldlen);
+
return (error);
}
* must be in kernel space.
*/
int
-userland_sysctl(struct proc *p, int *name, u_int namelen, user_addr_t oldp,
- size_t *oldlenp, user_addr_t newp, size_t newlen,
+userland_sysctl(boolean_t string_is_canonical,
+ char *namestring, size_t namestringlen,
+ int *name, u_int namelen, struct sysctl_req *req,
size_t *retval)
{
int error = 0;
- struct sysctl_req req, req2;
-
- bzero(&req, sizeof req);
-
- req.p = p;
-
- if (oldlenp) {
- req.oldlen = *oldlenp;
- }
-
- if (oldp) {
- req.oldptr = oldp;
- }
-
- if (newlen) {
- req.newlen = newlen;
- req.newptr = newp;
- }
-
- req.oldfunc = sysctl_old_user;
- req.newfunc = sysctl_new_user;
- req.lock = 1;
+ struct sysctl_req req2;
do {
- req2 = req;
- error = sysctl_root(0, name, namelen, &req2);
- } while (error == EAGAIN);
+ /* if EAGAIN, reset output cursor */
+ req2 = *req;
+ if (!string_is_canonical)
+ namestring[0] = '\0';
- req = req2;
+ error = sysctl_root(FALSE, string_is_canonical, namestring, namestringlen, name, namelen, &req2);
+ } while (error == EAGAIN);
if (error && error != ENOMEM)
return (error);
if (retval) {
- if (req.oldptr && req.oldidx > req.oldlen)
- *retval = req.oldlen;
+ if (req2.oldptr && req2.oldidx > req2.oldlen)
+ *retval = req2.oldlen;
else
- *retval = req.oldidx;
+ *retval = req2.oldidx;
}
return (error);
}
-/* Non-standard BSDI extension - only present on their 4.3 net-2 releases */
-#define KINFO_BSDI_SYSINFO (101<<8)
-
/*
* Kernel versions of the userland sysctl helper functions.
*
*
* Note that some sysctl handlers use copyin/copyout, which
* may not work correctly.
+ *
+ * The "sysctlbyname" KPI for use by kexts is aliased to this function.
*/
-static int
-sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
-{
-
- return(kernel_sysctl(current_proc(), name, namelen, oldp, oldlenp, newp, newlen));
-}
-
-static int
-sysctlnametomib(const char *name, int *mibp, size_t *sizep)
-{
- int oid[2];
- int error;
- char *non_const_name;
-
- /*
- * NOTE: This cast is safe because the service node does not modify
- * the contents of the string as part of its operation.
- */
- non_const_name = __CAST_AWAY_QUALIFIER(name, const, char *);
-
- /* magic service node */
- oid[0] = 0;
- oid[1] = 3;
-
- /* look up OID for name */
- *sizep *= sizeof(int);
- error = sysctl(oid, 2, mibp, sizep, non_const_name, strlen(name));
- *sizep /= sizeof(int);
-
- return(error);
-}
-
int
-sysctlbyname(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
+kernel_sysctlbyname(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
{
- int oid[CTL_MAXNAME + 2];
+ int oid[CTL_MAXNAME];
+ int name2mib_oid[2];
int error;
size_t oidlen;
- /* look up the OID */
- oidlen = CTL_MAXNAME;
- error = sysctlnametomib(name, oid, &oidlen);
+ /* look up the OID with magic service node */
+ name2mib_oid[0] = 0;
+ name2mib_oid[1] = 3;
+ oidlen = sizeof(oid);
+ error = kernel_sysctl(current_proc(), name2mib_oid, 2, oid, &oidlen, __DECONST(void *, name), strlen(name));
+ oidlen /= sizeof(int);
+
/* now use the OID */
if (error == 0)
- error = sysctl(oid, oidlen, oldp, oldlenp, newp, newlen);
+ error = kernel_sysctl(current_proc(), oid, oidlen, oldp, oldlenp, newp, newlen);
return(error);
}
projects / apple / xnu.git / blobdiff