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gems-kernel/source/THIRDPARTY/xnu/bsd/kern/kern_newsysctl.c

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add darwin/xnu functionality
2024-06-03 11:29:39 -05:00
/*
* Copyright (c) 2000-2019 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
* 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
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* 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@
*
*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Karels at Berkeley Software Design, Inc.
*
* Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
* project, to make these variables more userfriendly.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94
*/
#include <kern/counter.h>
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/kernel.h>
#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 <os/atomic_private.h>
#include <security/audit/audit.h>
#include <pexpert/pexpert.h>
#include <IOKit/IOBSD.h>
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif
#if defined(HAS_APPLE_PAC)
#include <os/hash.h>
#include <ptrauth.h>
#endif /* defined(HAS_APPLE_PAC) */
#include <libkern/coreanalytics/coreanalytics.h>
#if DEBUG || DEVELOPMENT
#include <os/system_event_log.h>
#endif /* DEBUG || DEVELOPMENT */
static LCK_GRP_DECLARE(sysctl_lock_group, "sysctl");
static LCK_RW_DECLARE(sysctl_geometry_lock, &sysctl_lock_group);
static LCK_MTX_DECLARE(sysctl_unlocked_node_lock, &sysctl_lock_group);
/*
* Conditionally allow dtrace to see these functions for debugging purposes.
*/
#ifdef STATIC
#undef STATIC
#endif
#if 0
#define STATIC
#else
#define STATIC static
#endif
/* 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, size_t *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, size_t namelen, struct sysctl_req *req);
int kernel_sysctl(struct proc *p, int *name, size_t 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);
SECURITY_READ_ONLY_LATE(struct sysctl_oid_list) sysctl__children; /* root list */
__SYSCTL_EXTENSION_NODE();
/*
* Initialization of the MIB tree.
*
* Order by number in each list.
*/
static void
sysctl_register_oid_locked(struct sysctl_oid *new_oidp,
struct sysctl_oid *oidp)
{
struct sysctl_oid_list *parent = new_oidp->oid_parent;
struct sysctl_oid_list *parent_rw = NULL;
struct sysctl_oid *p, **prevp;
p = SLIST_FIRST(parent);
if (p && p->oid_number == OID_MUTABLE_ANCHOR) {
parent_rw = p->oid_arg1;
}
if (oidp->oid_number == OID_AUTO) {
int n = OID_AUTO_START;
/*
* If this oid has a number OID_AUTO, give it a number which
* is greater than any current oid. Make sure it is at least
* OID_AUTO_START to leave space for pre-assigned oid numbers.
*/
SLIST_FOREACH_PREVPTR(p, prevp, parent, oid_link) {
if (p->oid_number >= n) {
n = p->oid_number + 1;
}
}
if (parent_rw) {
SLIST_FOREACH_PREVPTR(p, prevp, parent_rw, oid_link) {
if (p->oid_number >= n) {
n = p->oid_number + 1;
}
}
}
/*
* Reflect the number in an allocated OID into the template
* of the caller for sysctl_unregister_oid() compares.
*/
oidp->oid_number = new_oidp->oid_number = n;
} else {
/*
* Insert the oid into the parent's list in order.
*/
SLIST_FOREACH_PREVPTR(p, prevp, parent, oid_link) {
if (oidp->oid_number == p->oid_number) {
panic("attempting to register a sysctl at previously registered slot : %d",
oidp->oid_number);
} else if (oidp->oid_number < p->oid_number) {
break;
}
}
if (parent_rw) {
SLIST_FOREACH_PREVPTR(p, prevp, parent_rw, oid_link) {
if (oidp->oid_number == p->oid_number) {
panic("attempting to register a sysctl at previously registered slot : %d",
oidp->oid_number);
} else if (oidp->oid_number < p->oid_number) {
break;
}
}
}
}
#if defined(HAS_APPLE_PAC)
if (oidp->oid_handler) {
/*
* Sign oid_handler address-discriminated upon installation to make it
* harder to replace with an arbitrary function pointer. Blend with
* a hash of oid_arg1 for robustness against memory corruption.
*/
oidp->oid_handler = ptrauth_auth_and_resign(oidp->oid_handler,
ptrauth_key_function_pointer,
ptrauth_function_pointer_type_discriminator(typeof(oidp->oid_handler)),
ptrauth_key_function_pointer,
ptrauth_blend_discriminator(&oidp->oid_handler,
os_hash_kernel_pointer(oidp->oid_arg1)));
}
#endif /* defined(HAS_APPLE_PAC) */
SLIST_NEXT(oidp, oid_link) = *prevp;
*prevp = oidp;
}
void
sysctl_register_oid(struct sysctl_oid *new_oidp)
{
struct sysctl_oid *oidp;
if (new_oidp->oid_number < OID_AUTO) {
panic("trying to register a node %p with an invalid oid_number: %d",
new_oidp, new_oidp->oid_number);
}
if (new_oidp->oid_kind & CTLFLAG_PERMANENT) {
panic("Use sysctl_register_oid_early to register permanent nodes");
}
/*
* 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)) {
#if __x86_64__
oidp = kalloc_type(struct sysctl_oid, Z_WAITOK | Z_ZERO | Z_NOFAIL);
/*
* 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
panic("Old style sysctl without a version number isn't supported");
#endif
} 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 */
}
}
lck_rw_lock_exclusive(&sysctl_geometry_lock);
sysctl_register_oid_locked(new_oidp, oidp);
lck_rw_unlock_exclusive(&sysctl_geometry_lock);
}
__startup_func
void
sysctl_register_oid_early(struct sysctl_oid *oidp)
{
assert((oidp->oid_kind & CTLFLAG_OID2) &&
(oidp->oid_kind & CTLFLAG_PERMANENT) &&
oidp->oid_version == SYSCTL_OID_VERSION);
assert(startup_phase < STARTUP_SUB_SYSCTL);
/*
* Clear the flag so that callers can use sysctl_register_oid_early
* again if they wish to register their node.
*/
if (oidp->oid_kind & CTLFLAG_NOAUTO) {
oidp->oid_kind &= ~CTLFLAG_NOAUTO;
return;
}
sysctl_register_oid_locked(oidp, oidp);
}
void
sysctl_unregister_oid(struct sysctl_oid *oidp)
{
struct sysctl_oid *removed_oidp = NULL; /* OID removed from tree */
#if __x86_64__
struct sysctl_oid *old_oidp = NULL; /* OID compatibility copy */
#endif
struct sysctl_oid_list *lsp;
/* Get the write lock to modify the geometry */
lck_rw_lock_exclusive(&sysctl_geometry_lock);
lsp = oidp->oid_parent;
if (SLIST_FIRST(lsp) && SLIST_FIRST(lsp)->oid_number == OID_MUTABLE_ANCHOR) {
lsp = SLIST_FIRST(lsp)->oid_arg1;
}
if (oidp->oid_kind & CTLFLAG_PERMANENT) {
panic("Trying to unregister permanent sysctl %p", oidp);
}
if (!(oidp->oid_kind & CTLFLAG_OID2)) {
#if __x86_64__
/*
* 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, lsp, 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(lsp, old_oidp, sysctl_oid, oid_link);
removed_oidp = old_oidp;
}
#else
panic("Old style sysctl without a version number isn't supported");
#endif
} 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(lsp, oidp, sysctl_oid, oid_link);
removed_oidp = oidp;
break;
default:
/* XXX: Can't happen; probably tree coruption.*/
break; /* rejects unknown version */
}
}
#if defined(HAS_APPLE_PAC)
if (removed_oidp && removed_oidp->oid_handler) {
/*
* Revert address-discriminated signing performed by
* sysctl_register_oid() (in case this oid is registered again).
*/
removed_oidp->oid_handler = ptrauth_auth_and_resign(removed_oidp->oid_handler,
ptrauth_key_function_pointer,
ptrauth_blend_discriminator(&removed_oidp->oid_handler,
os_hash_kernel_pointer(removed_oidp->oid_arg1)),
ptrauth_key_function_pointer,
ptrauth_function_pointer_type_discriminator(typeof(removed_oidp->oid_handler)));
}
#endif /* defined(HAS_APPLE_PAC) */
/*
* 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);
#if __x86_64__
/* If it was allocated, free it after dropping the lock */
kfree_type(struct sysctl_oid, old_oidp);
#endif
}
/*
* Exported in BSDKernel.exports, kept for binary compatibility
*/
#if defined(__x86_64__)
void
sysctl_register_fixed(void)
{
}
#endif
/*
* New handler interface
* If the sysctl caller (user mode or kernel mode) is interested in the
* value (req->oldptr != NULL), we copy the data (bigValue etc.) out,
* if the caller wants to set the value (req->newptr), we copy
* the data in (*pValue etc.).
*/
int
sysctl_io_number(struct sysctl_req *req, long long bigValue, size_t valueSize, void *pValue, int *changed)
{
int smallValue;
int error;
if (changed) {
*changed = 0;
}
/*
* Handle the various combinations of caller buffer size and
* data value size. We are generous in the case where the
* caller has specified a 32-bit buffer but the value is 64-bit
* sized.
*/
/* 32 bit value expected or 32 bit buffer offered */
if (((valueSize == sizeof(int)) ||
((req->oldlen == sizeof(int)) && (valueSize == sizeof(long long))))
&& (req->oldptr)) {
smallValue = (int)bigValue;
if ((long long)smallValue != bigValue) {
return ERANGE;
}
error = SYSCTL_OUT(req, &smallValue, sizeof(smallValue));
} else {
/* any other case is either size-equal or a bug */
error = SYSCTL_OUT(req, &bigValue, valueSize);
}
/* error or nothing to set */
if (error || !req->newptr) {
return error;
}
/* set request for constant */
if (pValue == NULL) {
return EPERM;
}
/* set request needs to convert? */
if ((req->newlen == sizeof(int)) && (valueSize == sizeof(long long))) {
/* new value is 32 bits, upconvert to 64 bits */
error = SYSCTL_IN(req, &smallValue, sizeof(smallValue));
if (!error) {
*(long long *)pValue = (long long)smallValue;
}
} else if ((req->newlen == sizeof(long long)) && (valueSize == sizeof(int))) {
/* new value is 64 bits, downconvert to 32 bits and range check */
error = SYSCTL_IN(req, &bigValue, sizeof(bigValue));
if (!error) {
smallValue = (int)bigValue;
if ((long long)smallValue != bigValue) {
return ERANGE;
}
*(int *)pValue = smallValue;
}
} else {
/* sizes match, just copy in */
error = SYSCTL_IN(req, pValue, valueSize);
}
if (!error && changed) {
*changed = 1;
}
return error;
}
int
sysctl_io_string(struct sysctl_req *req, char *pValue, size_t valueSize, int trunc, int *changed)
{
int error;
size_t len = strlen(pValue) + 1;
if (changed) {
*changed = 0;
}
if (trunc && req->oldptr && req->oldlen && (req->oldlen < len)) {
/* If trunc != 0, if you give it a too small (but larger than
* 0 bytes) buffer, instead of returning ENOMEM, it truncates the
* returned string to the buffer size. This preserves the semantics
* of some library routines implemented via sysctl, which truncate
* their returned data, rather than simply returning an error. The
* returned string is always nul (ascii '\0') terminated. */
error = SYSCTL_OUT(req, pValue, req->oldlen - 1);
if (!error) {
char c = '\0';
error = SYSCTL_OUT(req, &c, 1);
}
} else {
/* Copy string out */
error = SYSCTL_OUT(req, pValue, len);
}
/* error or no new value */
if (error || !req->newptr) {
return error;
}
/* attempt to set read-only value */
if (valueSize == 0) {
return EPERM;
}
/* make sure there's room for the new string */
if (req->newlen >= valueSize) {
return EINVAL;
}
/* copy the string in and force nul termination */
error = SYSCTL_IN(req, pValue, req->newlen);
pValue[req->newlen] = '\0';
if (!error && changed) {
*changed = 1;
}
return error;
}
int
sysctl_io_opaque(struct sysctl_req *req, void *pValue, size_t valueSize, int *changed)
{
int error;
if (changed) {
*changed = 0;
}
/* Copy blob out */
error = SYSCTL_OUT(req, pValue, valueSize);
/* error or nothing to set */
if (error || !req->newptr) {
return error;
}
error = SYSCTL_IN(req, pValue, valueSize);
if (!error && changed) {
*changed = 1;
}
return error;
}
/*
* SYSCTL_OID enumerators
*
* Because system OIDs are immutable, they are composed of 2 lists hanging from
* a first dummy OID_MUTABLE_ANCHOR node that has an immutable list hanging from
* its `oid_parent` field and a mutable list hanging from its oid_arg1 one.
*
* Those enumerators abstract away the implicit merging of those two lists in
* two possible order:
* - oid_number order (which will interleave both sorted lists)
* - system order which will list the immutable list first,
* and the mutable list second.
*/
struct sysctl_oid_iterator {
struct sysctl_oid *a;
struct sysctl_oid *b;
};
static struct sysctl_oid_iterator
sysctl_oid_iterator_begin(struct sysctl_oid_list *l)
{
struct sysctl_oid_iterator it = { };
struct sysctl_oid *a = SLIST_FIRST(l);
if (a == NULL) {
return it;
}
if (a->oid_number == OID_MUTABLE_ANCHOR) {
it.a = SLIST_NEXT(a, oid_link);
it.b = SLIST_FIRST((struct sysctl_oid_list *)a->oid_arg1);
} else {
it.a = a;
}
return it;
}
static struct sysctl_oid *
sysctl_oid_iterator_next_num_order(struct sysctl_oid_iterator *it)
{
struct sysctl_oid *a = it->a;
struct sysctl_oid *b = it->b;
if (a == NULL && b == NULL) {
return NULL;
}
if (a == NULL) {
it->b = SLIST_NEXT(b, oid_link);
return b;
}
if (b == NULL || a->oid_number <= b->oid_number) {
it->a = SLIST_NEXT(a, oid_link);
return a;
}
it->b = SLIST_NEXT(b, oid_link);
return b;
}
#define SYSCTL_OID_FOREACH_NUM_ORDER(oidp, l) \
for (struct sysctl_oid_iterator it = sysctl_oid_iterator_begin(l); \
((oidp) = sysctl_oid_iterator_next_num_order(&it)); )
static struct sysctl_oid *
sysctl_oid_iterator_next_system_order(struct sysctl_oid_iterator *it)
{
struct sysctl_oid *a = it->a;
struct sysctl_oid *b = it->b;
if (a) {
it->a = SLIST_NEXT(a, oid_link);
return a;
}
if (b) {
it->b = SLIST_NEXT(b, oid_link);
return b;
}
return NULL;
}
#define SYSCTL_OID_FOREACH_SYS_ORDER(oidp, l) \
for (struct sysctl_oid_iterator it = sysctl_oid_iterator_begin(l); \
((oidp) = sysctl_oid_iterator_next_system_order(&it)); )
/*
* "Staff-functions"
*
* These functions implement a presently undocumented interface
* used by the sysctl program to walk the tree, and get the type
* so it can print the value.
* This interface is under work and consideration, and should probably
* be killed with a big axe by the first person who can find the time.
* (be aware though, that the proper interface isn't as obvious as it
* may seem, there are various conflicting requirements.
*
* {0,0} printf the entire MIB-tree.
* {0,1,...} return the name of the "..." OID.
* {0,2,...} return the next OID.
* {0,3} return the OID of the name in "new"
* {0,4,...} return the kind & format info for the "..." OID.
*/
/*
* 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)
{
struct sysctl_oid *oidp;
struct sysctl_oid_list *lp;
const char *what;
SYSCTL_OID_FOREACH_SYS_ORDER(oidp, l) {
switch (oidp->oid_kind & CTLTYPE) {
case CTLTYPE_NODE:
lp = oidp->oid_arg1;
what = "Node ";
if (lp && SLIST_FIRST(lp) &&
SLIST_FIRST(lp)->oid_number == OID_MUTABLE_ANCHOR) {
what = "NodeExt";
} else {
}
break;
case CTLTYPE_INT:
what = "Int ";
break;
case CTLTYPE_STRING:
what = "String ";
break;
case CTLTYPE_QUAD:
what = "Quad ";
break;
case CTLTYPE_OPAQUE:
what = "Opaque ";
break;
default:
what = "Unknown";
break;
}
printf("%*s%-3d[%c%c%c%c%c] %s %s\n", i, "", oidp->oid_number,
oidp->oid_kind & CTLFLAG_LOCKED ? 'L':' ',
oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
oidp->oid_kind & CTLFLAG_WR ? 'W':' ',
oidp->oid_kind & CTLFLAG_PERMANENT ? ' ':'*',
oidp->oid_handler ? 'h' : ' ',
what, oidp->oid_name);
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (!oidp->oid_handler) {
sysctl_sysctl_debug_dump_node(lp, i + 2);
}
}
}
}
/*
* 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 | CTLFLAG_LOCKED,
0, 0, sysctl_sysctl_debug, "-", "");
/*
* 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)
{
int *name = (int *) arg1;
u_int namelen = arg2;
int error = 0;
struct sysctl_oid *oid;
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);
if (req->oldidx) {
error = SYSCTL_OUT(req, ".", 1);
}
if (!error) {
error = SYSCTL_OUT(req, tempbuf, strlen(tempbuf));
}
if (error) {
lck_rw_done(&sysctl_geometry_lock);
return error;
}
namelen--;
name++;
continue;
}
lsp2 = 0;
SYSCTL_OID_FOREACH_NUM_ORDER(oid, lsp) {
if (oid->oid_number != *name) {
continue;
}
if (req->oldidx) {
error = SYSCTL_OUT(req, ".", 1);
}
if (!error) {
error = SYSCTL_OUT(req, oid->oid_name,
strlen(oid->oid_name));
}
if (error) {
lck_rw_done(&sysctl_geometry_lock);
return error;
}
namelen--;
name++;
if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) {
break;
}
if (oid->oid_handler) {
break;
}
lsp2 = (struct sysctl_oid_list *)oid->oid_arg1;
break;
}
lsp = lsp2;
}
lck_rw_done(&sysctl_geometry_lock);
return SYSCTL_OUT(req, "", 1);
}
SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_LOCKED, sysctl_sysctl_name, "");
/*
* 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)
{
struct sysctl_oid *oidp;
*len = level;
SYSCTL_OID_FOREACH_NUM_ORDER(oidp, lsp) {
*next = oidp->oid_number;
*oidpp = oidp;
if (!namelen) {
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) {
return 0;
}
if (oidp->oid_handler) {
/* We really should call the handler here...*/
return 0;
}
lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
if (!SLIST_FIRST(lsp)) {
/* This node had no children - skip it! */
continue;
}
if (!sysctl_sysctl_next_ls(lsp, 0, 0, next + 1,
len, level + 1, oidpp)) {
return 0;
}
goto next;
}
if (oidp->oid_number < *name) {
continue;
}
if (oidp->oid_number > *name) {
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) {
return 0;
}
if (oidp->oid_handler) {
return 0;
}
lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
if (!sysctl_sysctl_next_ls(lsp, name + 1, namelen - 1,
next + 1, len, level + 1, oidpp)) {
return 0;
}
goto next;
}
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) {
continue;
}
if (oidp->oid_handler) {
continue;
}
lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
if (!sysctl_sysctl_next_ls(lsp, name + 1, namelen - 1, next + 1,
len, level + 1, oidpp)) {
return 0;
}
next:
namelen = 1;
*len = level;
}
return 1;
}
/*
* 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)
{
int *name = (int *) arg1;
u_int namelen = arg2;
int i, j, error;
struct sysctl_oid *oid;
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 | CTLFLAG_LOCKED, sysctl_sysctl_next, "");
/*
* 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, size_t *len)
{
struct sysctl_oid_iterator it;
struct sysctl_oid *oidp;
char *p;
char i;
if (!*name) {
return ENOENT;
}
p = name + strlen(name) - 1;
if (*p == '.') {
*p = '\0';
}
*len = 0;
for (p = name; *p && *p != '.'; p++) {
;
}
i = *p;
if (i == '.') {
*p = '\0';
}
it = sysctl_oid_iterator_begin(&sysctl__children);
oidp = sysctl_oid_iterator_next_system_order(&it);
while (oidp && *len < CTL_MAXNAME) {
if (strcmp(name, oidp->oid_name)) {
oidp = sysctl_oid_iterator_next_system_order(&it);
continue;
}
*oid++ = oidp->oid_number;
(*len)++;
if (i == '\0') {
return 0;
}
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) {
break;
}
if (oidp->oid_handler) {
break;
}
it = sysctl_oid_iterator_begin(oidp->oid_arg1);
oidp = sysctl_oid_iterator_next_system_order(&it);
*p = i; /* restore */
name = p + 1;
for (p = name; *p && *p != '.'; p++) {
;
}
i = *p;
if (i == '.') {
*p = '\0';
}
}
return ENOENT;
}
/*
* 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] = {};
size_t len = 0; /* set by name2oid() */
if (req->newlen < 1) {
return ENOENT;
}
if (req->newlen >= MAXPATHLEN) { /* XXX arbitrary, undocumented */
return ENAMETOOLONG;
}
p = (char *)kalloc_data(req->newlen + 1, Z_WAITOK);
if (!p) {
return ENOMEM;
}
error = SYSCTL_IN(req, p, req->newlen);
if (error) {
kfree_data(p, req->newlen + 1);
return error;
}
p[req->newlen] = '\0';
/*
* 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);
kfree_data(p, req->newlen + 1);
if (error) {
return error;
}
error = SYSCTL_OUT(req, oid, len * sizeof *oid);
return error;
}
SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_KERN | CTLFLAG_LOCKED, 0, 0,
sysctl_sysctl_name2oid, "I", "");
/*
* 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;
int error = ENOENT; /* default error: not found */
u_int namelen = arg2;
u_int indx;
struct sysctl_oid_iterator it;
struct sysctl_oid *oid;
lck_rw_lock_shared(&sysctl_geometry_lock);
it = sysctl_oid_iterator_begin(&sysctl__children);
oid = sysctl_oid_iterator_next_system_order(&it);
indx = 0;
while (oid && indx < CTL_MAXNAME) {
if (oid->oid_number == name[indx]) {
indx++;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (oid->oid_handler) {
goto found;
}
if (indx == namelen) {
goto found;
}
it = sysctl_oid_iterator_begin(oid->oid_arg1);
oid = sysctl_oid_iterator_next_system_order(&it);
} else {
if (indx != namelen) {
error = EISDIR;
goto err;
}
goto found;
}
} else {
oid = sysctl_oid_iterator_next_system_order(&it);
}
}
/* Not found */
goto err;
found:
if (!oid->oid_fmt) {
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, "");
/*
* Default "handler" functions.
*/
/*
* Handle an int, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_int(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
return sysctl_io_number(req, arg1? *(int*)arg1: arg2, sizeof(int), arg1, NULL);
}
/*
* Handle a long, signed or unsigned. arg1 points to it.
*/
int
sysctl_handle_long(__unused struct sysctl_oid *oidp, void *arg1,
__unused int arg2, struct sysctl_req *req)
{
if (!arg1) {
return EINVAL;
}
return sysctl_io_number(req, *(long*)arg1, sizeof(long), arg1, NULL);
}
/*
* Handle a quad, signed or unsigned. arg1 points to it.
*/
int
sysctl_handle_quad(__unused struct sysctl_oid *oidp, void *arg1,
__unused int arg2, struct sysctl_req *req)
{
if (!arg1) {
return EINVAL;
}
return sysctl_io_number(req, *(long long*)arg1, sizeof(long long), arg1, NULL);
}
/*
* Expose an int value as a quad.
*
* This interface allows us to support interfaces defined
* as using quad values while the implementation is still
* using ints.
*/
int
sysctl_handle_int2quad(__unused struct sysctl_oid *oidp, void *arg1,
__unused int arg2, struct sysctl_req *req)
{
int error = 0;
long long val;
int newval;
if (!arg1) {
return EINVAL;
}
val = (long long)*(int *)arg1;
error = SYSCTL_OUT(req, &val, sizeof(long long));
if (error || !req->newptr) {
return error;
}
error = SYSCTL_IN(req, &val, sizeof(long long));
if (!error) {
/*
* Value must be representable; check by
* casting and then casting back.
*/
newval = (int)val;
if ((long long)newval != val) {
error = ERANGE;
} else {
*(int *)arg1 = newval;
}
}
return error;
}
/*
* Handle our generic '\0' terminated 'C' string.
* Two cases:
* a variable string: point arg1 at it, arg2 is max length.
* a constant string: point arg1 at it, arg2 is zero.
*/
int
sysctl_handle_string( __unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
return sysctl_io_string(req, arg1, arg2, 0, NULL);
}
/*
* Handle any kind of opaque data.
* arg1 points to it, arg2 is the size.
*/
int
sysctl_handle_opaque(__unused struct sysctl_oid *oidp, void *arg1, int arg2,
struct sysctl_req *req)
{
return sysctl_io_opaque(req, arg1, arg2, NULL);
}
/*
* Transfer functions to/from kernel space.
*/
STATIC int
sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
{
size_t i = 0;
if (req->oldptr) {
i = l;
if (i > req->oldlen - req->oldidx) {
i = req->oldlen - req->oldidx;
}
if (i > 0) {
bcopy((const void*)p, CAST_DOWN(char *, (req->oldptr + req->oldidx)), i);
}
}
req->oldidx += l;
if (req->oldptr && i != l) {
return ENOMEM;
}
return 0;
}
STATIC int
sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
{
if (!req->newptr) {
return 0;
}
if (req->newlen - req->newidx < l) {
return EINVAL;
}
bcopy(CAST_DOWN(char *, (req->newptr + req->newidx)), p, l);
req->newidx += l;
return 0;
}
int
kernel_sysctl(struct proc *p, int *name, size_t namelen, void *old, size_t *oldlenp, void *new, size_t newlen)
{
int error = 0;
struct sysctl_req req;
/*
* Construct request.
*/
bzero(&req, sizeof req);
req.p = p;
if (oldlenp) {
req.oldlen = *oldlenp;
}
if (old) {
req.oldptr = CAST_USER_ADDR_T(old);
}
if (newlen) {
req.newlen = newlen;
req.newptr = CAST_USER_ADDR_T(new);
}
req.oldfunc = sysctl_old_kernel;
req.newfunc = sysctl_new_kernel;
req.lock = 1;
/* make the request */
error = sysctl_root(TRUE, FALSE, NULL, 0, name, namelen, &req);
if (error && error != ENOMEM) {
return error;
}
if (oldlenp) {
*oldlenp = req.oldidx;
}
return error;
}
/*
* Transfer function to/from user space.
*/
STATIC int
sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
{
int error = 0;
size_t i = 0;
if (req->oldptr) {
if (req->oldlen - req->oldidx < l) {
return ENOMEM;
}
i = l;
if (i > req->oldlen - req->oldidx) {
i = req->oldlen - req->oldidx;
}
if (i > 0) {
error = copyout((const void*)p, (req->oldptr + req->oldidx), i);
}
}
req->oldidx += l;
if (error) {
return error;
}
if (req->oldptr && i < l) {
return ENOMEM;
}
return 0;
}
STATIC int
sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
{
int error;
if (!req->newptr) {
return 0;
}
if (req->newlen - req->newidx < l) {
return EINVAL;
}
error = copyin((req->newptr + req->newidx), p, l);
req->newidx += l;
return error;
}
#define WRITE_EXPERIMENT_FACTORS_ENTITLEMENT "com.apple.private.write-kr-experiment-factors"
/*
* Is the current task allowed to write to experiment factors?
* tasks with the WRITE_EXPERIMENT_FACTORS_ENTITLEMENT are always allowed to write these.
* In the development / debug kernel we also allow root to write them.
*/
STATIC bool
can_write_experiment_factors(__unused struct sysctl_req *req)
{
if (IOCurrentTaskHasEntitlement(WRITE_EXPERIMENT_FACTORS_ENTITLEMENT)) {
return true;
}
#if DEBUG || DEVELOPMENT
return !proc_suser(req->p);
#else
return false;
#endif /* DEBUG || DEVELOPMENT */
}
/*
* Traverse our tree, and find the right node, execute whatever it points
* at, and return the resulting error code.
*/
int
sysctl_root(boolean_t from_kernel, boolean_t string_is_canonical,
char *namestring, size_t namestringlen,
int *name, size_t namelen, struct sysctl_req *req)
{
u_int indx;
int i;
struct sysctl_oid_iterator it;
struct sysctl_oid *oid;
sysctl_handler_t oid_handler = NULL;
int error;
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;
}
}
it = sysctl_oid_iterator_begin(&sysctl__children);
oid = sysctl_oid_iterator_next_system_order(&it);
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)) {
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;
}
if (indx == namelen) {
error = ENOENT;
goto err;
}
it = sysctl_oid_iterator_begin(oid->oid_arg1);
oid = sysctl_oid_iterator_next_system_order(&it);
} else {
if (indx != namelen) {
error = EISDIR;
goto err;
}
goto found;
}
} else {
oid = sysctl_oid_iterator_next_system_order(&it);
}
}
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))) {
error = (EPERM);
goto err;
}
/*
* If we're inside the kernel, the OID must be marked as kernel-valid.
*/
if (from_kernel && !(oid->oid_kind & CTLFLAG_KERN)) {
error = (EPERM);
goto err;
}
if (req->newptr && req->p) {
if (oid->oid_kind & CTLFLAG_EXPERIMENT) {
/*
* Experiment factors have different permissions since they need to be
* writable by procs with WRITE_EXPERIMENT_FACTORS_ENTITLEMENT.
*/
if (!can_write_experiment_factors(req)) {
error = (EPERM);
goto err;
}
} else {
/*
* 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) &&
(error = proc_suser(req->p))) {
goto err;
}
}
}
/*
* sysctl_unregister_oid() may change the handler value, so grab it
* under the lock.
*/
oid_handler = oid->oid_handler;
if (!oid_handler) {
error = EINVAL;
goto err;
}
/*
* 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...
*/
if ((oid->oid_kind & CTLFLAG_PERMANENT) == 0) {
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) {
lck_mtx_lock(&sysctl_unlocked_node_lock);
}
#if defined(HAS_APPLE_PAC)
/*
* oid_handler is signed address-discriminated by sysctl_register_oid().
*/
oid_handler = ptrauth_auth_and_resign(oid_handler,
ptrauth_key_function_pointer,
ptrauth_blend_discriminator(&oid->oid_handler,
os_hash_kernel_pointer(oid->oid_arg1)),
ptrauth_key_function_pointer,
ptrauth_function_pointer_type_discriminator(typeof(oid_handler)));
#endif /* defined(HAS_APPLE_PAC) */
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
i = oid_handler(oid, name + indx, (int)(namelen - indx), req);
} else {
i = oid_handler(oid, oid->oid_arg1, oid->oid_arg2, req);
}
error = i;
if (unlocked_node_found) {
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 ((oid->oid_kind & CTLFLAG_PERMANENT) == 0) {
if (OSAddAtomic(-1, &oid->oid_refcnt) == 1) {
wakeup(&oid->oid_refcnt);
}
}
err:
lck_rw_done(&sysctl_geometry_lock);
return error;
}
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(proc_t p, struct sysctl_args *uap, __unused int32_t *retval)
{
int error, new_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" */
}
}
namestring = (char *)kalloc_data(namestringlen, Z_WAITOK);
if (!namestring) {
oldlen = 0;
goto err;
}
error = userland_sysctl(FALSE, namestring, namestringlen, name, uap->namelen, &req, &oldlen);
kfree_data(namestring, namestringlen);
if ((error) && (error != ENOMEM)) {
return error;
}
err:
if (uap->oldlenp != USER_ADDR_NULL) {
/*
* Only overwrite the old error value on a new error
*/
new_error = suulong(uap->oldlenp, oldlen);
if (new_error) {
error = new_error;
}
}
return error;
}
// sysctlbyname is also exported as KPI to kexts
// and the syscall name cannot conflict with it
int
sys_sysctlbyname(proc_t p, struct sysctlbyname_args *uap, __unused int32_t *retval)
{
int error, new_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;
name = (char *)kalloc_data(namelen + 1, Z_WAITOK);
if (!name) {
return ENOMEM;
}
error = copyin(uap->name, name, namelen);
if (error) {
kfree_data(name, namelen + 1);
return error;
}
name[namelen] = '\0';
/* XXX
* AUDIT_ARG(ctlname, name, uap->namelen);
*/
if (uap->newlen > SIZE_T_MAX) {
kfree_data(name, namelen + 1);
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);
kfree_data(name, namelen + 1);
if ((error) && (error != ENOMEM)) {
return error;
}
if (uap->oldlenp != USER_ADDR_NULL) {
/*
* Only overwrite the old error value on a new error
*/
new_error = suulong(uap->oldlenp, oldlen);
if (new_error) {
error = new_error;
}
}
return error;
}
/*
* This is used from various compatibility syscalls too. That's why name
* must be in kernel space.
*/
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)
{
int error = 0;
struct sysctl_req req2;
do {
/* if EAGAIN, reset output cursor */
req2 = *req;
if (!string_is_canonical) {
namestring[0] = '\0';
}
error = sysctl_root(FALSE, string_is_canonical, namestring, namestringlen, name, namelen, &req2);
} while (error == EAGAIN);
if (error && error != ENOMEM) {
return error;
}
if (retval) {
if (req2.oldptr && req2.oldidx > req2.oldlen) {
*retval = req2.oldlen;
} else {
*retval = req2.oldidx;
}
}
return error;
}
/*
* Kernel versions of the userland sysctl helper functions.
*
* These allow sysctl to be used in the same fashion in both
* userland and the kernel.
*
* 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.
*/
int
kernel_sysctlbyname(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
{
int oid[CTL_MAXNAME];
int name2mib_oid[2];
int error;
size_t 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);
if (oidlen > UINT_MAX) {
error = EDOM;
}
/* now use the OID */
if (error == 0) {
error = kernel_sysctl(current_proc(), oid, (u_int)oidlen, oldp, oldlenp, newp, newlen);
}
return error;
}
int
scalable_counter_sysctl_handler SYSCTL_HANDLER_ARGS
{
#pragma unused(arg2, oidp)
scalable_counter_t counter = *(scalable_counter_t*) arg1;
uint64_t value = counter_load(&counter);
return SYSCTL_OUT(req, &value, sizeof(value));
}
#define X(name, T) \
int \
experiment_factor_##name##_handler SYSCTL_HANDLER_ARGS \
{ \
int error, changed = 0; \
T *ptr; \
T new_value, current_value; \
struct experiment_spec *spec = (struct experiment_spec *) arg1; \
if (!arg1) { \
return EINVAL; \
} \
ptr = (T *)(spec->ptr); \
current_value = *ptr; \
error = sysctl_io_number(req, current_value, sizeof(T), &new_value, &changed); \
if (error != 0) { \
return error; \
} \
if (changed) { \
if (new_value < (T) spec->min_value || new_value > (T) spec->max_value) { \
return EINVAL; \
} \
if (os_atomic_cmpxchg(&spec->modified, false, true, acq_rel)) { \
spec->original_value = current_value; \
} \
os_atomic_store_wide(ptr, new_value, relaxed); \
} \
return 0; \
}
experiment_factor_numeric_types
#undef X
#if DEBUG || DEVELOPMENT
static int
sysctl_test_handler SYSCTL_HANDLER_ARGS
{
int error;
int64_t value, out = 0;
error = SYSCTL_IN(req, &value, sizeof(value));
/* Only run test when new value was provided to prevent just reading or
* querying from triggering the test, but still allow for sysctl
* presence tests via read requests with NULL oldptr */
if (error == 0 && req->newptr) {
/* call the test that was specified in SYSCTL_TEST_REGISTER */
error = ((int (*)(int64_t, int64_t *))(uintptr_t)arg1)(value, &out);
}
if (error == 0) {
error = SYSCTL_OUT(req, &out, sizeof(out));
}
return error;
}
void
sysctl_register_test_startup(struct sysctl_test_setup_spec *spec)
{
struct sysctl_oid *oid = zalloc_permanent_type(struct sysctl_oid);
*oid = (struct sysctl_oid){
.oid_parent = &sysctl__debug_test_children,
.oid_number = OID_AUTO,
.oid_kind = CTLTYPE_QUAD | CTLFLAG_OID2 | CTLFLAG_WR |
CTLFLAG_PERMANENT | CTLFLAG_LOCKED | CTLFLAG_MASKED,
.oid_arg1 = (void *)(uintptr_t)spec->st_func,
.oid_name = spec->st_name,
.oid_handler = sysctl_test_handler,
.oid_fmt = "Q",
.oid_version = SYSCTL_OID_VERSION,
.oid_descr = "",
};
sysctl_register_oid_early(oid);
}
extern void vm_analytics_tick(void *arg0, void *arg1);
/* Manual trigger of vm_analytics_tick for testing on dev/debug kernel. */
static int
sysctl_vm_analytics_tick SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int error, val = 0;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr) {
return error;
}
vm_analytics_tick(NULL, NULL);
return 0;
}
SYSCTL_PROC(_vm, OID_AUTO, analytics_report, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED, 0, 0, &sysctl_vm_analytics_tick, "I", "");
/* Manual trigger of record_system_event for testing on dev/debug kernel */
static int
sysctl_test_record_system_event SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int error, val = 0;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr) {
return error;
}
record_system_event(SYSTEM_EVENT_TYPE_INFO, SYSTEM_EVENT_SUBSYSTEM_TEST, "sysctl test", "this is a test %s", "message");
return 0;
}
SYSCTL_PROC(_kern, OID_AUTO, test_record_system_event, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED, 0, 0, &sysctl_test_record_system_event, "-", "");
#endif /* DEBUG || DEVELOPMENT */
CA_EVENT(ca_test_event,
CA_INT, TestKey,
CA_BOOL, TestBool,
CA_STATIC_STRING(CA_UUID_LEN), TestString);
/*
* Manual testing of sending a CoreAnalytics event
*/
static int
sysctl_test_ca_event SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int error, val = 0;
/*
* Only send on write
*/
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr) {
return error;
}
ca_event_t event = CA_EVENT_ALLOCATE(ca_test_event);
CA_EVENT_TYPE(ca_test_event) * event_data = event->data;
event_data->TestKey = val;
event_data->TestBool = true;
uuid_string_t test_str = "sysctl_test_ca_event";
strlcpy(event_data->TestString, test_str, CA_UUID_LEN);
CA_EVENT_SEND(event);
return 0;
}
SYSCTL_PROC(_kern, OID_AUTO, test_ca_event, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED, 0, 0, &sysctl_test_ca_event, "I", "");
#if DEVELOPMENT || DEBUG
kern_return_t
run_compressor_perf_test(
user_addr_t buf,
size_t buffer_size,
uint64_t *time,
uint64_t *bytes_compressed,
uint64_t *compressor_growth);
struct perf_compressor_data {
user_addr_t buffer;
size_t buffer_size;
uint64_t benchmark_time;
uint64_t bytes_processed;
uint64_t compressor_growth;
};
static int
sysctl_perf_compressor SYSCTL_HANDLER_ARGS
{
int error = EINVAL;
size_t len = sizeof(struct perf_compressor_data);
struct perf_compressor_data benchmark_data = {0};
if (req->oldptr == USER_ADDR_NULL || req->oldlen != len ||
req->newptr == USER_ADDR_NULL || req->newlen != len) {
return EINVAL;
}
error = SYSCTL_IN(req, &benchmark_data, len);
if (error) {
return error;
}
kern_return_t ret = run_compressor_perf_test(benchmark_data.buffer, benchmark_data.buffer_size,
&benchmark_data.benchmark_time, &benchmark_data.bytes_processed, &benchmark_data.compressor_growth);
switch (ret) {
case KERN_SUCCESS:
error = 0;
break;
case KERN_NOT_SUPPORTED:
error = ENOTSUP;
break;
case KERN_INVALID_ARGUMENT:
error = EINVAL;
break;
case KERN_RESOURCE_SHORTAGE:
error = EAGAIN;
break;
default:
error = ret;
break;
}
if (error != 0) {
return error;
}
return SYSCTL_OUT(req, &benchmark_data, len);
}
/*
* Compressor & swap performance test
*/
SYSCTL_PROC(_kern, OID_AUTO, perf_compressor, CTLFLAG_WR | CTLFLAG_MASKED | CTLTYPE_STRUCT,
0, 0, sysctl_perf_compressor, "S", "Compressor & swap benchmark");
#endif /* DEVELOPMENT || DEBUG */
#if CONFIG_JETSAM
extern uint32_t swapout_sleep_threshold;
#if DEVELOPMENT || DEBUG
SYSCTL_UINT(_vm, OID_AUTO, swapout_sleep_threshold, CTLFLAG_RW | CTLFLAG_LOCKED, &swapout_sleep_threshold, 0, "");
#else /* DEVELOPMENT || DEBUG */
SYSCTL_UINT(_vm, OID_AUTO, swapout_sleep_threshold, CTLFLAG_RD | CTLFLAG_LOCKED, &swapout_sleep_threshold, 0, "");
#endif /* DEVELOPMENT || DEBUG */
#endif /* CONFIG_JETSAM */
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