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freebsd/sys/kern/kern_sysctl.c
Mark Johnston d5eae57088 sysctl: Make sysctl_ctx_free() a bit safer 
Clear the list before returning so that sysctl_ctx_free() can be called
more than once on the same list without side effects.  This simplifies
error handling in drivers; previously, drivers would have to be careful
to call sysctl_ctx_free() at most once to avoid a use-after-free.

While here, use TAILQ_FOREACH_SAFE in the loop which unregisters OIDs.

Reviewed by:	thj, emaste
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D45041
2024-05-02 15:42:28 -04:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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.
*/
#include <sys/cdefs.h>
#include "opt_capsicum.h"
#include "opt_ddb.h"
#include "opt_ktrace.h"
#include "opt_sysctl.h"
#include <sys/param.h>
#include <sys/fail.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/jail.h>
#include <sys/kdb.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rmlock.h>
#include <sys/sbuf.h>
#include <sys/sx.h>
#include <sys/sysproto.h>
#include <sys/uio.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#ifdef DDB
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#endif
#include <net/vnet.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
RB_GENERATE(sysctl_oid_list, sysctl_oid, oid_link, cmp_sysctl_oid);
/*
* The sysctllock protects the MIB tree. It also protects sysctl
* contexts used with dynamic sysctls. The sysctl_register_oid() and
* sysctl_unregister_oid() routines require the sysctllock to already
* be held, so the sysctl_wlock() and sysctl_wunlock() routines are
* provided for the few places in the kernel which need to use that
* API rather than using the dynamic API. Use of the dynamic API is
* strongly encouraged for most code.
*
* The sysctlmemlock is used to limit the amount of user memory wired for
* sysctl requests. This is implemented by serializing any userland
* sysctl requests larger than a single page via an exclusive lock.
*
* The sysctlstringlock is used to protect concurrent access to writable
* string nodes in sysctl_handle_string().
*/
static struct rmlock sysctllock;
static struct sx __exclusive_cache_line sysctlmemlock;
static struct sx sysctlstringlock;
#define SYSCTL_WLOCK() rm_wlock(&sysctllock)
#define SYSCTL_WUNLOCK() rm_wunlock(&sysctllock)
#define SYSCTL_RLOCK(tracker) rm_rlock(&sysctllock, (tracker))
#define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker))
#define SYSCTL_WLOCKED() rm_wowned(&sysctllock)
#define SYSCTL_ASSERT_LOCKED() rm_assert(&sysctllock, RA_LOCKED)
#define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED)
#define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED)
#define SYSCTL_INIT() rm_init_flags(&sysctllock, "sysctl lock", \
RM_SLEEPABLE)
#define SYSCTL_SLEEP(ch, wmesg, timo) \
rm_sleep(ch, &sysctllock, 0, wmesg, timo)
static int sysctl_root(SYSCTL_HANDLER_ARGS);
/* Root list */
struct sysctl_oid_list sysctl__children = RB_INITIALIZER(&sysctl__children);
static char* sysctl_escape_name(const char*);
static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
int recurse);
static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t);
static int sysctl_new_kernel(struct sysctl_req *, void *, size_t);
static int name2oid(const char *, int *, int *, struct sysctl_oid **);
static struct sysctl_oid *
sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
{
struct sysctl_oid *oidp;
SYSCTL_ASSERT_LOCKED();
SYSCTL_FOREACH(oidp, list) {
if (strcmp(oidp->oid_name, name) == 0) {
return (oidp);
}
}
return (NULL);
}
static struct sysctl_oid *
sysctl_find_oidnamelen(const char *name, size_t len,
struct sysctl_oid_list *list)
{
struct sysctl_oid *oidp;
SYSCTL_ASSERT_LOCKED();
SYSCTL_FOREACH(oidp, list) {
if (strncmp(oidp->oid_name, name, len) == 0 &&
oidp->oid_name[len] == '\0')
return (oidp);
}
return (NULL);
}
/*
* Initialization of the MIB tree.
*
* Order by number in each list.
*/
void
sysctl_wlock(void)
{
SYSCTL_WLOCK();
}
void
sysctl_wunlock(void)
{
SYSCTL_WUNLOCK();
}
static int
sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2,
struct sysctl_req *req, struct rm_priotracker *tracker)
{
int error;
if (oid->oid_kind & CTLFLAG_DYN)
atomic_add_int(&oid->oid_running, 1);
if (tracker != NULL)
SYSCTL_RUNLOCK(tracker);
else
SYSCTL_WUNLOCK();
/*
* Treat set CTLFLAG_NEEDGIANT and unset CTLFLAG_MPSAFE flags the same,
* untill we're ready to remove all traces of Giant from sysctl(9).
*/
if ((oid->oid_kind & CTLFLAG_NEEDGIANT) ||
(!(oid->oid_kind & CTLFLAG_MPSAFE)))
mtx_lock(&Giant);
error = oid->oid_handler(oid, arg1, arg2, req);
if ((oid->oid_kind & CTLFLAG_NEEDGIANT) ||
(!(oid->oid_kind & CTLFLAG_MPSAFE)))
mtx_unlock(&Giant);
KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
if (tracker != NULL)
SYSCTL_RLOCK(tracker);
else
SYSCTL_WLOCK();
if (oid->oid_kind & CTLFLAG_DYN) {
if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 &&
(oid->oid_kind & CTLFLAG_DYING) != 0)
wakeup(&oid->oid_running);
}
return (error);
}
static void
sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp)
{
struct sysctl_req req;
struct sysctl_oid *curr;
char *penv = NULL;
char path[96];
ssize_t rem = sizeof(path);
ssize_t len;
uint8_t data[512] __aligned(sizeof(uint64_t));
int size;
int error;
path[--rem] = 0;
for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) {
len = strlen(curr->oid_name);
rem -= len;
if (curr != oidp)
rem -= 1;
if (rem < 0) {
printf("OID path exceeds %d bytes\n", (int)sizeof(path));
return;
}
memcpy(path + rem, curr->oid_name, len);
if (curr != oidp)
path[rem + len] = '.';
}
memset(&req, 0, sizeof(req));
req.td = curthread;
req.oldfunc = sysctl_old_kernel;
req.newfunc = sysctl_new_kernel;
req.lock = REQ_UNWIRED;
switch (oidp->oid_kind & CTLTYPE) {
case CTLTYPE_INT:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_UINT:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_LONG:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(long), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_ULONG:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(long), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_S8:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int8_t), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_S16:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int16_t), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_S32:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int32_t), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_S64:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(int64_t), GETENV_SIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_U8:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(uint8_t), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_U16:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(uint16_t), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_U32:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(uint32_t), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_U64:
if (getenv_array(path + rem, data, sizeof(data), &size,
sizeof(uint64_t), GETENV_UNSIGNED) == 0)
return;
req.newlen = size;
req.newptr = data;
break;
case CTLTYPE_STRING:
penv = kern_getenv(path + rem);
if (penv == NULL)
return;
req.newlen = strlen(penv);
req.newptr = penv;
break;
default:
return;
}
error = sysctl_root_handler_locked(oidp, oidp->oid_arg1,
oidp->oid_arg2, &req, NULL);
if (error != 0)
printf("Setting sysctl %s failed: %d\n", path + rem, error);
if (penv != NULL)
freeenv(penv);
}
/*
* Locate the path to a given oid. Returns the length of the resulting path,
* or -1 if the oid was not found. nodes must have room for CTL_MAXNAME
* elements.
*/
static int
sysctl_search_oid(struct sysctl_oid **nodes, struct sysctl_oid *needle)
{
int indx;
SYSCTL_ASSERT_LOCKED();
indx = 0;
/*
* Do a depth-first search of the oid tree, looking for 'needle'. Start
* with the first child of the root.
*/
nodes[indx] = RB_MIN(sysctl_oid_list, &sysctl__children);
for (;;) {
if (nodes[indx] == needle)
return (indx + 1);
if (nodes[indx] == NULL) {
/* Node has no more siblings, so back up to parent. */
if (indx-- == 0) {
/* Retreat to root, so give up. */
break;
}
} else if ((nodes[indx]->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
/* Node has children. */
if (++indx == CTL_MAXNAME) {
/* Max search depth reached, so give up. */
break;
}
/* Start with the first child. */
nodes[indx] = RB_MIN(sysctl_oid_list,
&nodes[indx - 1]->oid_children);
continue;
}
/* Consider next sibling. */
nodes[indx] = RB_NEXT(sysctl_oid_list, NULL, nodes[indx]);
}
return (-1);
}
static void
sysctl_warn_reuse(const char *func, struct sysctl_oid *leaf)
{
struct sysctl_oid *nodes[CTL_MAXNAME];
char buf[128];
struct sbuf sb;
int rc, i;
(void)sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN | SBUF_INCLUDENUL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_printf(&sb, "%s: can't re-use a leaf (", __func__);
rc = sysctl_search_oid(nodes, leaf);
if (rc > 0) {
for (i = 0; i < rc; i++)
sbuf_printf(&sb, "%s%.*s", nodes[i]->oid_name,
i != (rc - 1), ".");
} else {
sbuf_cat(&sb, leaf->oid_name);
}
sbuf_cat(&sb, ")!\n");
(void)sbuf_finish(&sb);
}
#ifdef SYSCTL_DEBUG
static int
sysctl_reuse_test(SYSCTL_HANDLER_ARGS)
{
struct rm_priotracker tracker;
SYSCTL_RLOCK(&tracker);
sysctl_warn_reuse(__func__, oidp);
SYSCTL_RUNLOCK(&tracker);
return (0);
}
SYSCTL_PROC(_sysctl, OID_AUTO, reuse_test,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0, sysctl_reuse_test, "-",
"");
#endif
void
sysctl_register_oid(struct sysctl_oid *oidp)
{
struct sysctl_oid_list *parent = oidp->oid_parent;
struct sysctl_oid *p, key;
int oid_number;
int timeout = 2;
/*
* First check if another oid with the same name already
* exists in the parent's list.
*/
SYSCTL_ASSERT_WLOCKED();
p = sysctl_find_oidname(oidp->oid_name, parent);
if (p != NULL) {
if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
p->oid_refcnt++;
return;
} else {
sysctl_warn_reuse(__func__, p);
return;
}
}
/* get current OID number */
oid_number = oidp->oid_number;
#if (OID_AUTO >= 0)
#error "OID_AUTO is expected to be a negative value"
#endif
/*
* Any negative OID number qualifies as OID_AUTO. Valid OID
* numbers should always be positive.
*
* NOTE: DO NOT change the starting value here, change it in
* <sys/sysctl.h>, and make sure it is at least 256 to
* accommodate e.g. net.inet.raw as a static sysctl node.
*/
if (oid_number < 0) {
static int newoid;
/*
* By decrementing the next OID number we spend less
* time inserting the OIDs into a sorted list.
*/
if (--newoid < CTL_AUTO_START)
newoid = 0x7fffffff;
oid_number = newoid;
}
/*
* Insert the OID into the parent's list sorted by OID number.
*/
key.oid_number = oid_number;
p = RB_NFIND(sysctl_oid_list, parent, &key);
while (p != NULL && oid_number == p->oid_number) {
/* get the next valid OID number */
if (oid_number < CTL_AUTO_START ||
oid_number == 0x7fffffff) {
/* wraparound - restart */
oid_number = CTL_AUTO_START;
/* don't loop forever */
if (!timeout--)
panic("sysctl: Out of OID numbers\n");
key.oid_number = oid_number;
p = RB_NFIND(sysctl_oid_list, parent, &key);
continue;
}
p = RB_NEXT(sysctl_oid_list, NULL, p);
oid_number++;
}
/* check for non-auto OID number collision */
if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START &&
oid_number >= CTL_AUTO_START) {
printf("sysctl: OID number(%d) is already in use for '%s'\n",
oidp->oid_number, oidp->oid_name);
}
/* update the OID number, if any */
oidp->oid_number = oid_number;
RB_INSERT(sysctl_oid_list, parent, oidp);
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
(oidp->oid_kind & CTLFLAG_TUN) != 0 &&
(oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
#ifdef VIMAGE
/*
* Can fetch value multiple times for VNET loader tunables.
* Only fetch once for non-VNET loader tunables.
*/
if ((oidp->oid_kind & CTLFLAG_VNET) == 0)
#endif
oidp->oid_kind |= CTLFLAG_NOFETCH;
/* try to fetch value from kernel environment */
sysctl_load_tunable_by_oid_locked(oidp);
}
}
void
sysctl_register_disabled_oid(struct sysctl_oid *oidp)
{
/*
* Mark the leaf as dormant if it's not to be immediately enabled.
* We do not disable nodes as they can be shared between modules
* and it is always safe to access a node.
*/
KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0,
("internal flag is set in oid_kind"));
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
oidp->oid_kind |= CTLFLAG_DORMANT;
sysctl_register_oid(oidp);
}
void
sysctl_enable_oid(struct sysctl_oid *oidp)
{
SYSCTL_ASSERT_WLOCKED();
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0,
("sysctl node is marked as dormant"));
return;
}
KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) != 0,
("enabling already enabled sysctl oid"));
oidp->oid_kind &= ~CTLFLAG_DORMANT;
}
void
sysctl_unregister_oid(struct sysctl_oid *oidp)
{
int error;
SYSCTL_ASSERT_WLOCKED();
if (oidp->oid_number == OID_AUTO) {
error = EINVAL;
} else {
error = ENOENT;
if (RB_REMOVE(sysctl_oid_list, oidp->oid_parent, oidp))
error = 0;
}
/*
* This can happen when a module fails to register and is
* being unloaded afterwards. It should not be a panic()
* for normal use.
*/
if (error) {
printf("%s: failed(%d) to unregister sysctl(%s)\n",
__func__, error, oidp->oid_name);
}
}
/* Initialize a new context to keep track of dynamically added sysctls. */
int
sysctl_ctx_init(struct sysctl_ctx_list *c)
{
if (c == NULL) {
return (EINVAL);
}
/*
* No locking here, the caller is responsible for not adding
* new nodes to a context until after this function has
* returned.
*/
TAILQ_INIT(c);
return (0);
}
/* Free the context, and destroy all dynamic oids registered in this context */
int
sysctl_ctx_free(struct sysctl_ctx_list *clist)
{
struct sysctl_ctx_entry *e, *e1;
int error;
error = 0;
/*
* First perform a "dry run" to check if it's ok to remove oids.
* XXX FIXME
* XXX This algorithm is a hack. But I don't know any
* XXX better solution for now...
*/
SYSCTL_WLOCK();
TAILQ_FOREACH(e, clist, link) {
error = sysctl_remove_oid_locked(e->entry, 0, 0);
if (error)
break;
}
/*
* Restore deregistered entries, either from the end,
* or from the place where error occurred.
* e contains the entry that was not unregistered
*/
if (error)
e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
else
e1 = TAILQ_LAST(clist, sysctl_ctx_list);
while (e1 != NULL) {
sysctl_register_oid(e1->entry);
e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
}
if (error) {
SYSCTL_WUNLOCK();
return(EBUSY);
}
/* Now really delete the entries */
TAILQ_FOREACH_SAFE(e, clist, link, e1) {
error = sysctl_remove_oid_locked(e->entry, 1, 0);
if (error)
panic("sysctl_remove_oid: corrupt tree, entry: %s",
e->entry->oid_name);
free(e, M_SYSCTLOID);
}
SYSCTL_WUNLOCK();
TAILQ_INIT(clist);
return (error);
}
/* Add an entry to the context */
struct sysctl_ctx_entry *
sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
{
struct sysctl_ctx_entry *e;
SYSCTL_ASSERT_WLOCKED();
if (clist == NULL || oidp == NULL)
return(NULL);
e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
e->entry = oidp;
TAILQ_INSERT_HEAD(clist, e, link);
return (e);
}
/* Find an entry in the context */
struct sysctl_ctx_entry *
sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
{
struct sysctl_ctx_entry *e;
SYSCTL_ASSERT_WLOCKED();
if (clist == NULL || oidp == NULL)
return(NULL);
TAILQ_FOREACH(e, clist, link) {
if (e->entry == oidp)
return(e);
}
return (e);
}
/*
* Delete an entry from the context.
* NOTE: this function doesn't free oidp! You have to remove it
* with sysctl_remove_oid().
*/
int
sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
{
struct sysctl_ctx_entry *e;
if (clist == NULL || oidp == NULL)
return (EINVAL);
SYSCTL_WLOCK();
e = sysctl_ctx_entry_find(clist, oidp);
if (e != NULL) {
TAILQ_REMOVE(clist, e, link);
SYSCTL_WUNLOCK();
free(e, M_SYSCTLOID);
return (0);
} else {
SYSCTL_WUNLOCK();
return (ENOENT);
}
}
/*
* Remove dynamically created sysctl trees.
* oidp - top of the tree to be removed
* del - if 0 - just deregister, otherwise free up entries as well
* recurse - if != 0 traverse the subtree to be deleted
*/
int
sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
{
int error;
SYSCTL_WLOCK();
error = sysctl_remove_oid_locked(oidp, del, recurse);
SYSCTL_WUNLOCK();
return (error);
}
int
sysctl_remove_name(struct sysctl_oid *parent, const char *name,
int del, int recurse)
{
struct sysctl_oid *p;
int error;
error = ENOENT;
SYSCTL_WLOCK();
p = sysctl_find_oidname(name, &parent->oid_children);
if (p)
error = sysctl_remove_oid_locked(p, del, recurse);
SYSCTL_WUNLOCK();
return (error);
}
/*
* Duplicate the provided string, escaping any illegal characters. The result
* must be freed when no longer in use.
*
* The list of illegal characters is ".".
*/
static char*
sysctl_escape_name(const char* orig)
{
int i, s = 0, d = 0, nillegals = 0;
char *new;
/* First count the number of illegal characters */
for (i = 0; orig[i] != '\0'; i++) {
if (orig[i] == '.')
nillegals++;
}
/* Allocate storage for new string */
new = malloc(i + 2 * nillegals + 1, M_SYSCTLOID, M_WAITOK);
/* Copy the name, escaping characters as we go */
while (orig[s] != '\0') {
if (orig[s] == '.') {
/* %25 is the hexadecimal representation of '.' */
new[d++] = '%';
new[d++] = '2';
new[d++] = '5';
s++;
} else {
new[d++] = orig[s++];
}
}
/* Finally, nul-terminate */
new[d] = '\0';
return (new);
}
static int
sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
{
struct sysctl_oid *p, *tmp;
int error;
SYSCTL_ASSERT_WLOCKED();
if (oidp == NULL)
return(EINVAL);
if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
printf("Warning: can't remove non-dynamic nodes (%s)!\n",
oidp->oid_name);
return (EINVAL);
}
/*
* WARNING: normal method to do this should be through
* sysctl_ctx_free(). Use recursing as the last resort
* method to purge your sysctl tree of leftovers...
* However, if some other code still references these nodes,
* it will panic.
*/
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (oidp->oid_refcnt == 1) {
for(p = RB_MIN(sysctl_oid_list, &oidp->oid_children);
p != NULL; p = tmp) {
if (!recurse) {
printf("Warning: failed attempt to "
"remove oid %s with child %s\n",
oidp->oid_name, p->oid_name);
return (ENOTEMPTY);
}
tmp = RB_NEXT(sysctl_oid_list,
&oidp->oid_children, p);
error = sysctl_remove_oid_locked(p, del,
recurse);
if (error)
return (error);
}
}
}
if (oidp->oid_refcnt > 1 ) {
oidp->oid_refcnt--;
} else {
if (oidp->oid_refcnt == 0) {
printf("Warning: bad oid_refcnt=%u (%s)!\n",
oidp->oid_refcnt, oidp->oid_name);
return (EINVAL);
}
sysctl_unregister_oid(oidp);
if (del) {
/*
* Wait for all threads running the handler to drain.
* This preserves the previous behavior when the
* sysctl lock was held across a handler invocation,
* and is necessary for module unload correctness.
*/
while (oidp->oid_running > 0) {
oidp->oid_kind |= CTLFLAG_DYING;
SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
}
if (oidp->oid_descr)
free(__DECONST(char *, oidp->oid_descr),
M_SYSCTLOID);
if (oidp->oid_label)
free(__DECONST(char *, oidp->oid_label),
M_SYSCTLOID);
free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
free(oidp, M_SYSCTLOID);
}
}
return (0);
}
/*
* Create new sysctls at run time.
* clist may point to a valid context initialized with sysctl_ctx_init().
*/
struct sysctl_oid *
sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
int number, const char *name, int kind, void *arg1, intmax_t arg2,
int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr,
const char *label)
{
struct sysctl_oid *oidp;
char *escaped;
/* You have to hook up somewhere.. */
if (parent == NULL)
return(NULL);
escaped = sysctl_escape_name(name);
/* Check if the node already exists, otherwise create it */
SYSCTL_WLOCK();
oidp = sysctl_find_oidname(escaped, parent);
if (oidp != NULL) {
free(escaped, M_SYSCTLOID);
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
oidp->oid_refcnt++;
/* Update the context */
if (clist != NULL)
sysctl_ctx_entry_add(clist, oidp);
SYSCTL_WUNLOCK();
return (oidp);
} else {
sysctl_warn_reuse(__func__, oidp);
SYSCTL_WUNLOCK();
return (NULL);
}
}
oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
oidp->oid_parent = parent;
RB_INIT(&oidp->oid_children);
oidp->oid_number = number;
oidp->oid_refcnt = 1;
oidp->oid_name = escaped;
oidp->oid_handler = handler;
oidp->oid_kind = CTLFLAG_DYN | kind;
oidp->oid_arg1 = arg1;
oidp->oid_arg2 = arg2;
oidp->oid_fmt = fmt;
if (descr != NULL)
oidp->oid_descr = strdup(descr, M_SYSCTLOID);
if (label != NULL)
oidp->oid_label = strdup(label, M_SYSCTLOID);
/* Update the context, if used */
if (clist != NULL)
sysctl_ctx_entry_add(clist, oidp);
/* Register this oid */
sysctl_register_oid(oidp);
SYSCTL_WUNLOCK();
return (oidp);
}
/*
* Rename an existing oid.
*/
void
sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
{
char *newname;
char *oldname;
newname = strdup(name, M_SYSCTLOID);
SYSCTL_WLOCK();
oldname = __DECONST(char *, oidp->oid_name);
oidp->oid_name = newname;
SYSCTL_WUNLOCK();
free(oldname, M_SYSCTLOID);
}
/*
* Reparent an existing oid.
*/
int
sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
{
struct sysctl_oid *oidp;
SYSCTL_WLOCK();
if (oid->oid_parent == parent) {
SYSCTL_WUNLOCK();
return (0);
}
oidp = sysctl_find_oidname(oid->oid_name, parent);
if (oidp != NULL) {
SYSCTL_WUNLOCK();
return (EEXIST);
}
sysctl_unregister_oid(oid);
oid->oid_parent = parent;
oid->oid_number = OID_AUTO;
sysctl_register_oid(oid);
SYSCTL_WUNLOCK();
return (0);
}
/*
* Register the kernel's oids on startup.
*/
SET_DECLARE(sysctl_set, struct sysctl_oid);
static void
sysctl_register_all(void *arg)
{
struct sysctl_oid **oidp;
sx_init(&sysctlmemlock, "sysctl mem");
sx_init(&sysctlstringlock, "sysctl string handler");
SYSCTL_INIT();
SYSCTL_WLOCK();
SET_FOREACH(oidp, sysctl_set)
sysctl_register_oid(*oidp);
SYSCTL_WUNLOCK();
}
SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, NULL);
#ifdef VIMAGE
static void
sysctl_setenv_vnet(void *arg __unused, const char *name)
{
struct sysctl_oid *oidp;
int oid[CTL_MAXNAME];
int error, nlen;
SYSCTL_WLOCK();
error = name2oid(name, oid, &nlen, &oidp);
if (error)
goto out;
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
(oidp->oid_kind & CTLFLAG_VNET) != 0 &&
(oidp->oid_kind & CTLFLAG_TUN) != 0 &&
(oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
/* Update value from kernel environment */
sysctl_load_tunable_by_oid_locked(oidp);
}
out:
SYSCTL_WUNLOCK();
}
static void
sysctl_unsetenv_vnet(void *arg __unused, const char *name)
{
struct sysctl_oid *oidp;
int oid[CTL_MAXNAME];
int error, nlen;
SYSCTL_WLOCK();
/*
* The setenv / unsetenv event handlers are invoked by kern_setenv() /
* kern_unsetenv() without exclusive locks. It is rare but still possible
* that the invoke order of event handlers is different from that of
* kern_setenv() and kern_unsetenv().
* Re-check environment variable string to make sure it is unset.
*/
if (testenv(name))
goto out;
error = name2oid(name, oid, &nlen, &oidp);
if (error)
goto out;
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
(oidp->oid_kind & CTLFLAG_VNET) != 0 &&
(oidp->oid_kind & CTLFLAG_TUN) != 0 &&
(oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
size_t size;
switch (oidp->oid_kind & CTLTYPE) {
case CTLTYPE_INT:
case CTLTYPE_UINT:
size = sizeof(int);
break;
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
size = sizeof(long);
break;
case CTLTYPE_S8:
case CTLTYPE_U8:
size = sizeof(int8_t);
break;
case CTLTYPE_S16:
case CTLTYPE_U16:
size = sizeof(int16_t);
break;
case CTLTYPE_S32:
case CTLTYPE_U32:
size = sizeof(int32_t);
break;
case CTLTYPE_S64:
case CTLTYPE_U64:
size = sizeof(int64_t);
break;
case CTLTYPE_STRING:
MPASS(oidp->oid_arg2 > 0);
size = oidp->oid_arg2;
break;
default:
goto out;
}
vnet_restore_init(oidp->oid_arg1, size);
}
out:
SYSCTL_WUNLOCK();
}
/*
* Register the kernel's setenv / unsetenv events.
*/
EVENTHANDLER_DEFINE(setenv, sysctl_setenv_vnet, NULL, EVENTHANDLER_PRI_ANY);
EVENTHANDLER_DEFINE(unsetenv, sysctl_unsetenv_vnet, NULL, EVENTHANDLER_PRI_ANY);
#endif
/*
* "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.
*
* {CTL_SYSCTL, CTL_SYSCTL_DEBUG} printf the entire MIB-tree.
* {CTL_SYSCTL, CTL_SYSCTL_NAME, ...} return the name of the "..."
* OID.
* {CTL_SYSCTL, CTL_SYSCTL_NEXT, ...} return the next OID, honoring
* CTLFLAG_SKIP.
* {CTL_SYSCTL, CTL_SYSCTL_NAME2OID} return the OID of the name in
* "new"
* {CTL_SYSCTL, CTL_SYSCTL_OIDFMT, ...} return the kind & format info
* for the "..." OID.
* {CTL_SYSCTL, CTL_SYSCTL_OIDDESCR, ...} return the description of the
* "..." OID.
* {CTL_SYSCTL, CTL_SYSCTL_OIDLABEL, ...} return the aggregation label of
* the "..." OID.
* {CTL_SYSCTL, CTL_SYSCTL_NEXTNOSKIP, ...} return the next OID, ignoring
* CTLFLAG_SKIP.
*/
#ifdef SYSCTL_DEBUG
static void
sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
{
int k;
struct sysctl_oid *oidp;
SYSCTL_ASSERT_LOCKED();
SYSCTL_FOREACH(oidp, l) {
for (k=0; k<i; k++)
printf(" ");
printf("%d %s ", oidp->oid_number, oidp->oid_name);
printf("%c%c",
oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
if (oidp->oid_handler)
printf(" *Handler");
switch (oidp->oid_kind & CTLTYPE) {
case CTLTYPE_NODE:
printf(" Node\n");
if (!oidp->oid_handler) {
sysctl_sysctl_debug_dump_node(
SYSCTL_CHILDREN(oidp), i + 2);
}
break;
case CTLTYPE_INT: printf(" Int\n"); break;
case CTLTYPE_UINT: printf(" u_int\n"); break;
case CTLTYPE_LONG: printf(" Long\n"); break;
case CTLTYPE_ULONG: printf(" u_long\n"); break;
case CTLTYPE_STRING: printf(" String\n"); break;
case CTLTYPE_S8: printf(" int8_t\n"); break;
case CTLTYPE_S16: printf(" int16_t\n"); break;
case CTLTYPE_S32: printf(" int32_t\n"); break;
case CTLTYPE_S64: printf(" int64_t\n"); break;
case CTLTYPE_U8: printf(" uint8_t\n"); break;
case CTLTYPE_U16: printf(" uint16_t\n"); break;
case CTLTYPE_U32: printf(" uint32_t\n"); break;
case CTLTYPE_U64: printf(" uint64_t\n"); break;
case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
default: printf("\n");
}
}
}
static int
sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
{
struct rm_priotracker tracker;
int error;
error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
if (error)
return (error);
SYSCTL_RLOCK(&tracker);
sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
SYSCTL_RUNLOCK(&tracker);
return (ENOENT);
}
SYSCTL_PROC(_sysctl, CTL_SYSCTL_DEBUG, debug, CTLTYPE_STRING | CTLFLAG_RD |
CTLFLAG_MPSAFE, 0, 0, sysctl_sysctl_debug, "-", "");
#endif
static int
sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
{
int *name = (int *) arg1;
u_int namelen = arg2;
int error;
struct sysctl_oid *oid, key;
struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
struct rm_priotracker tracker;
char buf[10];
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
SYSCTL_RLOCK(&tracker);
while (namelen) {
if (!lsp) {
snprintf(buf,sizeof(buf),"%d",*name);
if (req->oldidx)
error = SYSCTL_OUT(req, ".", 1);
if (!error)
error = SYSCTL_OUT(req, buf, strlen(buf));
if (error)
goto out;
namelen--;
name++;
continue;
}
lsp2 = NULL;
key.oid_number = *name;
oid = RB_FIND(sysctl_oid_list, lsp, &key);
if (oid) {
if (req->oldidx)
error = SYSCTL_OUT(req, ".", 1);
if (!error)
error = SYSCTL_OUT(req, oid->oid_name,
strlen(oid->oid_name));
if (error)
goto out;
namelen--;
name++;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE &&
!oid->oid_handler)
lsp2 = SYSCTL_CHILDREN(oid);
}
lsp = lsp2;
}
error = SYSCTL_OUT(req, "", 1);
out:
SYSCTL_RUNLOCK(&tracker);
return (error);
}
/*
* XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
* capability mode.
*/
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NAME, name, CTLFLAG_RD |
CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_name, "");
enum sysctl_iter_action {
ITER_SIBLINGS, /* Not matched, continue iterating siblings */
ITER_CHILDREN, /* Node has children we need to iterate over them */
ITER_FOUND, /* Matching node was found */
};
/*
* Tries to find the next node for @name and @namelen.
*
* Returns next action to take.
*/
static enum sysctl_iter_action
sysctl_sysctl_next_node(struct sysctl_oid *oidp, int *name, unsigned int namelen,
bool honor_skip)
{
if ((oidp->oid_kind & CTLFLAG_DORMANT) != 0)
return (ITER_SIBLINGS);
if (honor_skip && (oidp->oid_kind & CTLFLAG_SKIP) != 0)
return (ITER_SIBLINGS);
if (namelen == 0) {
/*
* We have reached a node with a full name match and are
* looking for the next oid in its children.
*
* For CTL_SYSCTL_NEXTNOSKIP we are done.
*
* For CTL_SYSCTL_NEXT we skip CTLTYPE_NODE (unless it
* has a handler) and move on to the children.
*/
if (!honor_skip)
return (ITER_FOUND);
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
return (ITER_FOUND);
/* If node does not have an iterator, treat it as leaf */
if (oidp->oid_handler)
return (ITER_FOUND);
/* Report oid as a node to iterate */
return (ITER_CHILDREN);
}
/*
* No match yet. Continue seeking the given name.
*
* We are iterating in order by oid_number, so skip oids lower
* than the one we are looking for.
*
* When the current oid_number is higher than the one we seek,
* that means we have reached the next oid in the sequence and
* should return it.
*
* If the oid_number matches the name at this level then we
* have to find a node to continue searching at the next level.
*/
if (oidp->oid_number < *name)
return (ITER_SIBLINGS);
if (oidp->oid_number > *name) {
/*
* We have reached the next oid.
*
* For CTL_SYSCTL_NEXTNOSKIP we are done.
*
* For CTL_SYSCTL_NEXT we skip CTLTYPE_NODE (unless it
* has a handler) and move on to the children.
*/
if (!honor_skip)
return (ITER_FOUND);
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
return (ITER_FOUND);
/* If node does not have an iterator, treat it as leaf */
if (oidp->oid_handler)
return (ITER_FOUND);
return (ITER_CHILDREN);
}
/* match at a current level */
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
return (ITER_SIBLINGS);
if (oidp->oid_handler)
return (ITER_SIBLINGS);
return (ITER_CHILDREN);
}
/*
* Recursively walk the sysctl subtree at lsp until we find the given name.
* Returns true and fills in next oid data in @next and @len if oid is found.
*/
static bool
sysctl_sysctl_next_action(struct sysctl_oid_list *lsp, int *name, u_int namelen,
int *next, int *len, int level, bool honor_skip)
{
struct sysctl_oid_list *next_lsp;
struct sysctl_oid *oidp = NULL, key;
bool success = false;
enum sysctl_iter_action action;
SYSCTL_ASSERT_LOCKED();
/*
* Start the search at the requested oid. But if not found, then scan
* through all children.
*/
if (namelen > 0) {
key.oid_number = *name;
oidp = RB_FIND(sysctl_oid_list, lsp, &key);
}
if (!oidp)
oidp = RB_MIN(sysctl_oid_list, lsp);
for(; oidp != NULL; oidp = RB_NEXT(sysctl_oid_list, lsp, oidp)) {
action = sysctl_sysctl_next_node(oidp, name, namelen,
honor_skip);
if (action == ITER_SIBLINGS)
continue;
if (action == ITER_FOUND) {
success = true;
break;
}
KASSERT((action== ITER_CHILDREN), ("ret(%d)!=ITER_CHILDREN", action));
next_lsp = SYSCTL_CHILDREN(oidp);
if (namelen == 0) {
success = sysctl_sysctl_next_action(next_lsp, NULL, 0,
next + 1, len, level + 1, honor_skip);
} else {
success = sysctl_sysctl_next_action(next_lsp, name + 1,
namelen - 1, next + 1, len, level + 1, honor_skip);
if (!success) {
/*
* We maintain the invariant that current node oid
* is >= the oid provided in @name.
* As there are no usable children at this node,
* current node oid is strictly > than the requested
* oid.
* Hence, reduce namelen to 0 to allow for picking first
* nodes/leafs in the next node in list.
*/
namelen = 0;
}
}
if (success)
break;
}
if (success) {
*next = oidp->oid_number;
if (level > *len)
*len = level;
}
return (success);
}
static int
sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
{
int *name = (int *) arg1;
u_int namelen = arg2;
int len, error;
bool success;
struct sysctl_oid_list *lsp = &sysctl__children;
struct rm_priotracker tracker;
int next[CTL_MAXNAME];
len = 0;
SYSCTL_RLOCK(&tracker);
success = sysctl_sysctl_next_action(lsp, name, namelen, next, &len, 1,
oidp->oid_number == CTL_SYSCTL_NEXT);
SYSCTL_RUNLOCK(&tracker);
if (!success)
return (ENOENT);
error = SYSCTL_OUT(req, next, len * sizeof (int));
return (error);
}
/*
* XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
* capability mode.
*/
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NEXT, next, CTLFLAG_RD |
CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_next, "");
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NEXTNOSKIP, nextnoskip, CTLFLAG_RD |
CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_next, "");
static int
name2oid(const char *name, int *oid, int *len, struct sysctl_oid **oidpp)
{
struct sysctl_oid *oidp;
struct sysctl_oid_list *lsp = &sysctl__children;
const char *n;
SYSCTL_ASSERT_LOCKED();
for (*len = 0; *len < CTL_MAXNAME;) {
n = strchrnul(name, '.');
oidp = sysctl_find_oidnamelen(name, n - name, lsp);
if (oidp == NULL)
return (ENOENT);
*oid++ = oidp->oid_number;
(*len)++;
name = n;
if (*name == '.')
name++;
if (*name == '\0') {
if (oidpp)
*oidpp = oidp;
return (0);
}
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
break;
if (oidp->oid_handler)
break;
lsp = SYSCTL_CHILDREN(oidp);
}
return (ENOENT);
}
static int
sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
{
char *p;
int error, oid[CTL_MAXNAME], len = 0;
struct sysctl_oid *op = NULL;
struct rm_priotracker tracker;
char buf[32];
if (!req->newlen)
return (ENOENT);
if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
return (ENAMETOOLONG);
p = buf;
if (req->newlen >= sizeof(buf))
p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
error = SYSCTL_IN(req, p, req->newlen);
if (error) {
if (p != buf)
free(p, M_SYSCTL);
return (error);
}
p [req->newlen] = '\0';
SYSCTL_RLOCK(&tracker);
error = name2oid(p, oid, &len, &op);
SYSCTL_RUNLOCK(&tracker);
if (p != buf)
free(p, M_SYSCTL);
if (error)
return (error);
error = SYSCTL_OUT(req, oid, len * sizeof *oid);
return (error);
}
/*
* XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
* capability mode.
*/
SYSCTL_PROC(_sysctl, CTL_SYSCTL_NAME2OID, name2oid, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_ANYBODY | CTLFLAG_MPSAFE | CTLFLAG_CAPRW, 0, 0,
sysctl_sysctl_name2oid, "I", "");
static int
sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
struct rm_priotracker tracker;
int error;
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
SYSCTL_RLOCK(&tracker);
error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
if (error)
goto out;
if (oid->oid_fmt == NULL) {
error = ENOENT;
goto out;
}
error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
if (error)
goto out;
error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
out:
SYSCTL_RUNLOCK(&tracker);
return (error);
}
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDFMT, oidfmt, CTLFLAG_RD |
CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidfmt, "");
static int
sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
struct rm_priotracker tracker;
int error;
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
SYSCTL_RLOCK(&tracker);
error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
if (error)
goto out;
if (oid->oid_descr == NULL) {
error = ENOENT;
goto out;
}
error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
out:
SYSCTL_RUNLOCK(&tracker);
return (error);
}
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDDESCR, oiddescr, CTLFLAG_RD |
CTLFLAG_MPSAFE|CTLFLAG_CAPRD, sysctl_sysctl_oiddescr, "");
static int
sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
struct rm_priotracker tracker;
int error;
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
SYSCTL_RLOCK(&tracker);
error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
if (error)
goto out;
if (oid->oid_label == NULL) {
error = ENOENT;
goto out;
}
error = SYSCTL_OUT(req, oid->oid_label, strlen(oid->oid_label) + 1);
out:
SYSCTL_RUNLOCK(&tracker);
return (error);
}
static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDLABEL, oidlabel, CTLFLAG_RD |
CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, "");
/*
* Default "handler" functions.
*/
/*
* Handle a bool.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_bool(SYSCTL_HANDLER_ARGS)
{
uint8_t temp;
int error;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
temp = *(bool *)arg1 ? 1 : 0;
else
temp = arg2 ? 1 : 0;
error = SYSCTL_OUT(req, &temp, sizeof(temp));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else {
error = SYSCTL_IN(req, &temp, sizeof(temp));
if (!error)
*(bool *)arg1 = temp ? 1 : 0;
}
return (error);
}
/*
* Handle an int8_t, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_8(SYSCTL_HANDLER_ARGS)
{
int8_t tmpout;
int error = 0;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmpout = *(int8_t *)arg1;
else
tmpout = arg2;
error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else
error = SYSCTL_IN(req, arg1, sizeof(tmpout));
return (error);
}
/*
* Handle an int16_t, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_16(SYSCTL_HANDLER_ARGS)
{
int16_t tmpout;
int error = 0;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmpout = *(int16_t *)arg1;
else
tmpout = arg2;
error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else
error = SYSCTL_IN(req, arg1, sizeof(tmpout));
return (error);
}
/*
* Handle an int32_t, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_32(SYSCTL_HANDLER_ARGS)
{
int32_t tmpout;
int error = 0;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmpout = *(int32_t *)arg1;
else
tmpout = arg2;
error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else
error = SYSCTL_IN(req, arg1, sizeof(tmpout));
return (error);
}
/*
* Handle an int, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_int(SYSCTL_HANDLER_ARGS)
{
int tmpout, error = 0;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmpout = *(int *)arg1;
else
tmpout = arg2;
error = SYSCTL_OUT(req, &tmpout, sizeof(int));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else
error = SYSCTL_IN(req, arg1, sizeof(int));
return (error);
}
/*
* Based on sysctl_handle_int() convert milliseconds into ticks.
* Note: this is used by TCP.
*/
int
sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
{
int error, s, tt;
tt = *(int *)arg1;
s = (int)((int64_t)tt * 1000 / hz);
error = sysctl_handle_int(oidp, &s, 0, req);
if (error || !req->newptr)
return (error);
tt = (int)((int64_t)s * hz / 1000);
if (tt < 1)
return (EINVAL);
*(int *)arg1 = tt;
return (0);
}
/*
* Handle a long, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_long(SYSCTL_HANDLER_ARGS)
{
int error = 0;
long tmplong;
#ifdef SCTL_MASK32
int tmpint;
#endif
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmplong = *(long *)arg1;
else
tmplong = arg2;
#ifdef SCTL_MASK32
if (req->flags & SCTL_MASK32) {
tmpint = tmplong;
error = SYSCTL_OUT(req, &tmpint, sizeof(int));
} else
#endif
error = SYSCTL_OUT(req, &tmplong, sizeof(long));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
#ifdef SCTL_MASK32
else if (req->flags & SCTL_MASK32) {
error = SYSCTL_IN(req, &tmpint, sizeof(int));
*(long *)arg1 = (long)tmpint;
}
#endif
else
error = SYSCTL_IN(req, arg1, sizeof(long));
return (error);
}
/*
* Handle a 64 bit int, signed or unsigned.
* Two cases:
* a variable: point arg1 at it.
* a constant: pass it in arg2.
*/
int
sysctl_handle_64(SYSCTL_HANDLER_ARGS)
{
int error = 0;
uint64_t tmpout;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (arg1)
tmpout = *(uint64_t *)arg1;
else
tmpout = arg2;
error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
if (error || !req->newptr)
return (error);
if (!arg1)
error = EPERM;
else
error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
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(SYSCTL_HANDLER_ARGS)
{
char *tmparg;
size_t outlen;
int error = 0, ro_string = 0;
/*
* If the sysctl isn't writable and isn't a preallocated tunable that
* can be modified by kenv(2), microoptimise and treat it as a
* read-only string.
* A zero-length buffer indicates a fixed size read-only
* string. In ddb, don't worry about trying to make a malloced
* snapshot.
*/
if ((oidp->oid_kind & (CTLFLAG_WR | CTLFLAG_TUN)) == 0 ||
arg2 == 0 || kdb_active) {
arg2 = strlen((char *)arg1) + 1;
ro_string = 1;
}
if (req->oldptr != NULL) {
if (ro_string) {
tmparg = arg1;
outlen = strlen(tmparg) + 1;
} else {
tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
sx_slock(&sysctlstringlock);
memcpy(tmparg, arg1, arg2);
sx_sunlock(&sysctlstringlock);
outlen = strlen(tmparg) + 1;
}
error = SYSCTL_OUT(req, tmparg, outlen);
if (!ro_string)
free(tmparg, M_SYSCTLTMP);
} else {
if (!ro_string)
sx_slock(&sysctlstringlock);
outlen = strlen((char *)arg1) + 1;
if (!ro_string)
sx_sunlock(&sysctlstringlock);
error = SYSCTL_OUT(req, NULL, outlen);
}
if (error || !req->newptr)
return (error);
if (req->newlen - req->newidx >= arg2 ||
req->newlen - req->newidx < 0) {
error = EINVAL;
} else if (req->newlen - req->newidx == 0) {
sx_xlock(&sysctlstringlock);
((char *)arg1)[0] = '\0';
sx_xunlock(&sysctlstringlock);
} else if (req->newfunc == sysctl_new_kernel) {
arg2 = req->newlen - req->newidx;
sx_xlock(&sysctlstringlock);
error = SYSCTL_IN(req, arg1, arg2);
if (error == 0) {
((char *)arg1)[arg2] = '\0';
req->newidx += arg2;
}
sx_xunlock(&sysctlstringlock);
} else {
arg2 = req->newlen - req->newidx;
tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
error = SYSCTL_IN(req, tmparg, arg2);
if (error) {
free(tmparg, M_SYSCTLTMP);
return (error);
}
sx_xlock(&sysctlstringlock);
memcpy(arg1, tmparg, arg2);
((char *)arg1)[arg2] = '\0';
sx_xunlock(&sysctlstringlock);
free(tmparg, M_SYSCTLTMP);
req->newidx += arg2;
}
return (error);
}
/*
* Handle any kind of opaque data.
* arg1 points to it, arg2 is the size.
*/
int
sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
{
int error, tries;
u_int generation;
struct sysctl_req req2;
/*
* Attempt to get a coherent snapshot, by using the thread
* pre-emption counter updated from within mi_switch() to
* determine if we were pre-empted during a bcopy() or
* copyout(). Make 3 attempts at doing this before giving up.
* If we encounter an error, stop immediately.
*/
tries = 0;
req2 = *req;
retry:
generation = curthread->td_generation;
error = SYSCTL_OUT(req, arg1, arg2);
if (error)
return (error);
tries++;
if (generation != curthread->td_generation && tries < 3) {
*req = req2;
goto retry;
}
error = SYSCTL_IN(req, arg1, arg2);
return (error);
}
/*
* Based on sysctl_handle_64() convert microseconds to a sbintime.
*/
int
sysctl_usec_to_sbintime(SYSCTL_HANDLER_ARGS)
{
int error;
int64_t usec;
usec = sbttous(*(sbintime_t *)arg1);
error = sysctl_handle_64(oidp, &usec, 0, req);
if (error || !req->newptr)
return (error);
*(sbintime_t *)arg1 = ustosbt(usec);
return (0);
}
/*
* Based on sysctl_handle_64() convert milliseconds to a sbintime.
*/
int
sysctl_msec_to_sbintime(SYSCTL_HANDLER_ARGS)
{
int error;
int64_t msec;
msec = sbttoms(*(sbintime_t *)arg1);
error = sysctl_handle_64(oidp, &msec, 0, req);
if (error || !req->newptr)
return (error);
*(sbintime_t *)arg1 = mstosbt(msec);
return (0);
}
/*
* Convert seconds to a struct timeval. Intended for use with
* intervals and thus does not permit negative seconds.
*/
int
sysctl_sec_to_timeval(SYSCTL_HANDLER_ARGS)
{
struct timeval *tv;
int error, secs;
tv = arg1;
secs = tv->tv_sec;
error = sysctl_handle_int(oidp, &secs, 0, req);
if (error || req->newptr == NULL)
return (error);
if (secs < 0)
return (EINVAL);
tv->tv_sec = secs;
return (0);
}
/*
* Transfer functions to/from kernel space.
* XXX: rather untested at this point
*/
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 (req->oldlen <= req->oldidx)
i = 0;
else
if (i > req->oldlen - req->oldidx)
i = req->oldlen - req->oldidx;
if (i > 0)
bcopy(p, (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((const char *)req->newptr + req->newidx, p, l);
req->newidx += l;
return (0);
}
int
kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
{
int error = 0;
struct sysctl_req req;
bzero(&req, sizeof req);
req.td = td;
req.flags = flags;
if (oldlenp) {
req.oldlen = *oldlenp;
}
req.validlen = req.oldlen;
if (old) {
req.oldptr= old;
}
if (new != NULL) {
req.newlen = newlen;
req.newptr = new;
}
req.oldfunc = sysctl_old_kernel;
req.newfunc = sysctl_new_kernel;
req.lock = REQ_UNWIRED;
error = sysctl_root(0, name, namelen, &req);
if (req.lock == REQ_WIRED && req.validlen > 0)
vsunlock(req.oldptr, req.validlen);
if (error && error != ENOMEM)
return (error);
if (retval) {
if (req.oldptr && req.oldidx > req.validlen)
*retval = req.validlen;
else
*retval = req.oldidx;
}
return (error);
}
int
kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
void *new, size_t newlen, size_t *retval, int flags)
{
int oid[CTL_MAXNAME];
size_t oidlen, plen;
int error;
oid[0] = CTL_SYSCTL;
oid[1] = CTL_SYSCTL_NAME2OID;
oidlen = sizeof(oid);
error = kernel_sysctl(td, oid, 2, oid, &oidlen,
(void *)name, strlen(name), &plen, flags);
if (error)
return (error);
error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
new, newlen, retval, flags);
return (error);
}
/*
* Transfer function to/from user space.
*/
static int
sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
{
size_t i, len, origidx;
int error;
origidx = req->oldidx;
req->oldidx += l;
if (req->oldptr == NULL)
return (0);
/*
* If we have not wired the user supplied buffer and we are currently
* holding locks, drop a witness warning, as it's possible that
* write operations to the user page can sleep.
*/
if (req->lock != REQ_WIRED)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"sysctl_old_user()");
i = l;
len = req->validlen;
if (len <= origidx)
i = 0;
else {
if (i > len - origidx)
i = len - origidx;
if (req->lock == REQ_WIRED) {
error = copyout_nofault(p, (char *)req->oldptr +
origidx, i);
} else
error = copyout(p, (char *)req->oldptr + origidx, i);
if (error != 0)
return (error);
}
if (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);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"sysctl_new_user()");
error = copyin((const char *)req->newptr + req->newidx, p, l);
req->newidx += l;
return (error);
}
/*
* Wire the user space destination buffer. If set to a value greater than
* zero, the len parameter limits the maximum amount of wired memory.
*/
int
sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
{
int ret;
size_t wiredlen;
wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
ret = 0;
if (req->lock != REQ_WIRED && req->oldptr &&
req->oldfunc == sysctl_old_user) {
if (wiredlen != 0) {
ret = vslock(req->oldptr, wiredlen);
if (ret != 0) {
if (ret != ENOMEM)
return (ret);
wiredlen = 0;
}
}
req->lock = REQ_WIRED;
req->validlen = wiredlen;
}
return (0);
}
int
sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
int *nindx, struct sysctl_req *req)
{
struct sysctl_oid_list *lsp;
struct sysctl_oid *oid;
struct sysctl_oid key;
int indx;
SYSCTL_ASSERT_LOCKED();
lsp = &sysctl__children;
indx = 0;
while (indx < CTL_MAXNAME) {
key.oid_number = name[indx];
oid = RB_FIND(sysctl_oid_list, lsp, &key);
if (oid == NULL)
return (ENOENT);
indx++;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (oid->oid_handler != NULL || indx == namelen) {
*noid = oid;
if (nindx != NULL)
*nindx = indx;
KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
("%s found DYING node %p", __func__, oid));
return (0);
}
lsp = SYSCTL_CHILDREN(oid);
} else if (indx == namelen) {
if ((oid->oid_kind & CTLFLAG_DORMANT) != 0)
return (ENOENT);
*noid = oid;
if (nindx != NULL)
*nindx = indx;
KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
("%s found DYING node %p", __func__, oid));
return (0);
} else {
return (ENOTDIR);
}
}
return (ENOENT);
}
/*
* Traverse our tree, and find the right node, execute whatever it points
* to, and return the resulting error code.
*/
static int
sysctl_root(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
struct rm_priotracker tracker;
int error, indx, lvl;
SYSCTL_RLOCK(&tracker);
error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
if (error)
goto out;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
/*
* You can't call a sysctl when it's a node, but has
* no handler. Inform the user that it's a node.
* The indx may or may not be the same as namelen.
*/
if (oid->oid_handler == NULL) {
error = EISDIR;
goto out;
}
}
/* Is this sysctl writable? */
if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) {
error = EPERM;
goto out;
}
KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
#ifdef CAPABILITY_MODE
/*
* If the process is in capability mode, then don't permit reading or
* writing unless specifically granted for the node.
*/
if (IN_CAPABILITY_MODE(req->td)) {
if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) ||
(req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) {
error = EPERM;
goto out;
}
}
#endif
/* Is this sysctl sensitive to securelevels? */
if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
error = securelevel_gt(req->td->td_ucred, lvl);
if (error)
goto out;
}
/* Is this sysctl writable by only privileged users? */
if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
int priv;
if (oid->oid_kind & CTLFLAG_PRISON)
priv = PRIV_SYSCTL_WRITEJAIL;
#ifdef VIMAGE
else if ((oid->oid_kind & CTLFLAG_VNET) &&
prison_owns_vnet(req->td->td_ucred))
priv = PRIV_SYSCTL_WRITEJAIL;
#endif
else
priv = PRIV_SYSCTL_WRITE;
error = priv_check(req->td, priv);
if (error)
goto out;
}
if (!oid->oid_handler) {
error = EINVAL;
goto out;
}
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
arg1 = (int *)arg1 + indx;
arg2 -= indx;
} else {
arg1 = oid->oid_arg1;
arg2 = oid->oid_arg2;
}
#ifdef MAC
error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
req);
if (error != 0)
goto out;
#endif
#ifdef VIMAGE
if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL)
arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
#endif
error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker);
out:
SYSCTL_RUNLOCK(&tracker);
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
int
sys___sysctl(struct thread *td, struct __sysctl_args *uap)
{
int error, i, name[CTL_MAXNAME];
size_t j;
if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
return (EINVAL);
error = copyin(uap->name, &name, uap->namelen * sizeof(int));
if (error)
return (error);
error = userland_sysctl(td, name, uap->namelen,
uap->old, uap->oldlenp, 0,
uap->new, uap->newlen, &j, 0);
if (error && error != ENOMEM)
return (error);
if (uap->oldlenp) {
i = copyout(&j, uap->oldlenp, sizeof(j));
if (i)
return (i);
}
return (error);
}
int
kern___sysctlbyname(struct thread *td, const char *oname, size_t namelen,
void *old, size_t *oldlenp, void *new, size_t newlen, size_t *retval,
int flags, bool inkernel)
{
int oid[CTL_MAXNAME];
char namebuf[16];
char *name;
size_t oidlen;
int error;
if (namelen > MAXPATHLEN || namelen == 0)
return (EINVAL);
name = namebuf;
if (namelen > sizeof(namebuf))
name = malloc(namelen, M_SYSCTL, M_WAITOK);
error = copyin(oname, name, namelen);
if (error != 0)
goto out;
oid[0] = CTL_SYSCTL;
oid[1] = CTL_SYSCTL_NAME2OID;
oidlen = sizeof(oid);
error = kernel_sysctl(td, oid, 2, oid, &oidlen, (void *)name, namelen,
retval, flags);
if (error != 0)
goto out;
error = userland_sysctl(td, oid, *retval / sizeof(int), old, oldlenp,
inkernel, new, newlen, retval, flags);
out:
if (namelen > sizeof(namebuf))
free(name, M_SYSCTL);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct __sysctlbyname_args {
const char *name;
size_t namelen;
void *old;
size_t *oldlenp;
void *new;
size_t newlen;
};
#endif
int
sys___sysctlbyname(struct thread *td, struct __sysctlbyname_args *uap)
{
size_t rv;
int error;
error = kern___sysctlbyname(td, uap->name, uap->namelen, uap->old,
uap->oldlenp, uap->new, uap->newlen, &rv, 0, 0);
if (error != 0)
return (error);
if (uap->oldlenp != NULL)
error = copyout(&rv, uap->oldlenp, sizeof(rv));
return (error);
}
/*
* This is used from various compatibility syscalls too. That's why name
* must be in kernel space.
*/
int
userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
size_t *oldlenp, int inkernel, const void *new, size_t newlen,
size_t *retval, int flags)
{
int error = 0, memlocked;
struct sysctl_req req;
bzero(&req, sizeof req);
req.td = td;
req.flags = flags;
if (oldlenp) {
if (inkernel) {
req.oldlen = *oldlenp;
} else {
error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
if (error)
return (error);
}
}
req.validlen = req.oldlen;
req.oldptr = old;
if (new != NULL) {
req.newlen = newlen;
req.newptr = new;
}
req.oldfunc = sysctl_old_user;
req.newfunc = sysctl_new_user;
req.lock = REQ_UNWIRED;
#ifdef KTRACE
if (KTRPOINT(curthread, KTR_SYSCTL))
ktrsysctl(name, namelen);
#endif
memlocked = 0;
if (req.oldptr && req.oldlen > 4 * PAGE_SIZE) {
memlocked = 1;
sx_xlock(&sysctlmemlock);
}
CURVNET_SET(TD_TO_VNET(td));
for (;;) {
req.oldidx = 0;
req.newidx = 0;
error = sysctl_root(0, name, namelen, &req);
if (error != EAGAIN)
break;
kern_yield(PRI_USER);
}
CURVNET_RESTORE();
if (req.lock == REQ_WIRED && req.validlen > 0)
vsunlock(req.oldptr, req.validlen);
if (memlocked)
sx_xunlock(&sysctlmemlock);
if (error && error != ENOMEM)
return (error);
if (retval) {
if (req.oldptr && req.oldidx > req.validlen)
*retval = req.validlen;
else
*retval = req.oldidx;
}
return (error);
}
/*
* Drain into a sysctl struct. The user buffer should be wired if a page
* fault would cause issue.
*/
static int
sbuf_sysctl_drain(void *arg, const char *data, int len)
{
struct sysctl_req *req = arg;
int error;
error = SYSCTL_OUT(req, data, len);
KASSERT(error >= 0, ("Got unexpected negative value %d", error));
return (error == 0 ? len : -error);
}
struct sbuf *
sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
struct sysctl_req *req)
{
/* Supply a default buffer size if none given. */
if (buf == NULL && length == 0)
length = 64;
s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
sbuf_set_drain(s, sbuf_sysctl_drain, req);
return (s);
}
#ifdef DDB
/* The current OID the debugger is working with */
static struct sysctl_oid *g_ddb_oid;
/* The current flags specified by the user */
static int g_ddb_sysctl_flags;
/* Check to see if the last sysctl printed */
static int g_ddb_sysctl_printed;
static const int ctl_sign[CTLTYPE+1] = {
[CTLTYPE_INT] = 1,
[CTLTYPE_LONG] = 1,
[CTLTYPE_S8] = 1,
[CTLTYPE_S16] = 1,
[CTLTYPE_S32] = 1,
[CTLTYPE_S64] = 1,
};
static const int ctl_size[CTLTYPE+1] = {
[CTLTYPE_INT] = sizeof(int),
[CTLTYPE_UINT] = sizeof(u_int),
[CTLTYPE_LONG] = sizeof(long),
[CTLTYPE_ULONG] = sizeof(u_long),
[CTLTYPE_S8] = sizeof(int8_t),
[CTLTYPE_S16] = sizeof(int16_t),
[CTLTYPE_S32] = sizeof(int32_t),
[CTLTYPE_S64] = sizeof(int64_t),
[CTLTYPE_U8] = sizeof(uint8_t),
[CTLTYPE_U16] = sizeof(uint16_t),
[CTLTYPE_U32] = sizeof(uint32_t),
[CTLTYPE_U64] = sizeof(uint64_t),
};
#define DB_SYSCTL_NAME_ONLY 0x001 /* Compare with -N */
#define DB_SYSCTL_VALUE_ONLY 0x002 /* Compare with -n */
#define DB_SYSCTL_OPAQUE 0x004 /* Compare with -o */
#define DB_SYSCTL_HEX 0x008 /* Compare with -x */
#define DB_SYSCTL_SAFE_ONLY 0x100 /* Only simple types */
static const char db_sysctl_modifs[] = {
'N', 'n', 'o', 'x',
};
static const int db_sysctl_modif_values[] = {
DB_SYSCTL_NAME_ONLY, DB_SYSCTL_VALUE_ONLY,
DB_SYSCTL_OPAQUE, DB_SYSCTL_HEX,
};
/* Handlers considered safe to print while recursing */
static int (* const db_safe_handlers[])(SYSCTL_HANDLER_ARGS) = {
sysctl_handle_bool,
sysctl_handle_8,
sysctl_handle_16,
sysctl_handle_32,
sysctl_handle_64,
sysctl_handle_int,
sysctl_handle_long,
sysctl_handle_string,
sysctl_handle_opaque,
};
/*
* Use in place of sysctl_old_kernel to print sysctl values.
*
* Compare to the output handling in show_var from sbin/sysctl/sysctl.c
*/
static int
sysctl_old_ddb(struct sysctl_req *req, const void *ptr, size_t len)
{
const u_char *val, *p;
const char *sep1;
size_t intlen, slen;
uintmax_t umv;
intmax_t mv;
int sign, ctltype, hexlen, xflag, error;
/* Suppress false-positive GCC uninitialized variable warnings */
mv = 0;
umv = 0;
slen = len;
val = p = ptr;
if (ptr == NULL) {
error = 0;
goto out;
}
/* We are going to print */
g_ddb_sysctl_printed = 1;
xflag = g_ddb_sysctl_flags & DB_SYSCTL_HEX;
ctltype = (g_ddb_oid->oid_kind & CTLTYPE);
sign = ctl_sign[ctltype];
intlen = ctl_size[ctltype];
switch (ctltype) {
case CTLTYPE_NODE:
case CTLTYPE_STRING:
db_printf("%.*s", (int) len, (const char *) p);
error = 0;
goto out;
case CTLTYPE_INT:
case CTLTYPE_UINT:
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
case CTLTYPE_S8:
case CTLTYPE_S16:
case CTLTYPE_S32:
case CTLTYPE_S64:
case CTLTYPE_U8:
case CTLTYPE_U16:
case CTLTYPE_U32:
case CTLTYPE_U64:
hexlen = 2 + (intlen * CHAR_BIT + 3) / 4;
sep1 = "";
while (len >= intlen) {
switch (ctltype) {
case CTLTYPE_INT:
case CTLTYPE_UINT:
umv = *(const u_int *)p;
mv = *(const int *)p;
break;
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
umv = *(const u_long *)p;
mv = *(const long *)p;
break;
case CTLTYPE_S8:
case CTLTYPE_U8:
umv = *(const uint8_t *)p;
mv = *(const int8_t *)p;
break;
case CTLTYPE_S16:
case CTLTYPE_U16:
umv = *(const uint16_t *)p;
mv = *(const int16_t *)p;
break;
case CTLTYPE_S32:
case CTLTYPE_U32:
umv = *(const uint32_t *)p;
mv = *(const int32_t *)p;
break;
case CTLTYPE_S64:
case CTLTYPE_U64:
umv = *(const uint64_t *)p;
mv = *(const int64_t *)p;
break;
}
db_printf("%s", sep1);
if (xflag)
db_printf("%#0*jx", hexlen, umv);
else if (!sign)
db_printf("%ju", umv);
else if (g_ddb_oid->oid_fmt[1] == 'K') {
/* Kelvins are currently unsupported. */
error = EOPNOTSUPP;
goto out;
} else
db_printf("%jd", mv);
sep1 = " ";
len -= intlen;
p += intlen;
}
error = 0;
goto out;
case CTLTYPE_OPAQUE:
/* TODO: Support struct functions. */
/* FALLTHROUGH */
default:
db_printf("Format:%s Length:%zu Dump:0x",
g_ddb_oid->oid_fmt, len);
while (len-- && (xflag || p < val + 16))
db_printf("%02x", *p++);
if (!xflag && len > 16)
db_printf("...");
error = 0;
goto out;
}
out:
req->oldidx += slen;
return (error);
}
/*
* Avoid setting new sysctl values from the debugger
*/
static int
sysctl_new_ddb(struct sysctl_req *req, void *p, size_t l)
{
if (!req->newptr)
return (0);
/* Changing sysctls from the debugger is currently unsupported */
return (EPERM);
}
/*
* Run a sysctl handler with the DDB oldfunc and newfunc attached.
* Instead of copying any output to a buffer we'll dump it right to
* the console.
*/
static int
db_sysctl(struct sysctl_oid *oidp, int *name, u_int namelen,
void *old, size_t *oldlenp, size_t *retval, int flags)
{
struct sysctl_req req;
int error;
/* Setup the request */
bzero(&req, sizeof req);
req.td = kdb_thread;
req.oldfunc = sysctl_old_ddb;
req.newfunc = sysctl_new_ddb;
req.lock = REQ_UNWIRED;
if (oldlenp) {
req.oldlen = *oldlenp;
}
req.validlen = req.oldlen;
if (old) {
req.oldptr = old;
}
/* Setup our globals for sysctl_old_ddb */
g_ddb_oid = oidp;
g_ddb_sysctl_flags = flags;
g_ddb_sysctl_printed = 0;
error = sysctl_root(0, name, namelen, &req);
/* Reset globals */
g_ddb_oid = NULL;
g_ddb_sysctl_flags = 0;
if (retval) {
if (req.oldptr && req.oldidx > req.validlen)
*retval = req.validlen;
else
*retval = req.oldidx;
}
return (error);
}
/*
* Show a sysctl's name
*/
static void
db_show_oid_name(int *oid, size_t nlen)
{
struct sysctl_oid *oidp;
int qoid[CTL_MAXNAME + 2];
int error;
qoid[0] = CTL_SYSCTL;
qoid[1] = CTL_SYSCTL_NAME;
memcpy(qoid + 2, oid, nlen * sizeof(int));
error = sysctl_find_oid(qoid, nlen + 2, &oidp, NULL, NULL);
if (error)
db_error("sysctl name oid");
error = db_sysctl(oidp, qoid, nlen + 2, NULL, NULL, NULL, 0);
if (error)
db_error("sysctl name");
}
/*
* Check to see if an OID is safe to print from ddb.
*/
static bool
db_oid_safe(const struct sysctl_oid *oidp)
{
for (unsigned int i = 0; i < nitems(db_safe_handlers); ++i) {
if (oidp->oid_handler == db_safe_handlers[i])
return (true);
}
return (false);
}
/*
* Show a sysctl at a specific OID
* Compare to the input handling in show_var from sbin/sysctl/sysctl.c
*/
static int
db_show_oid(struct sysctl_oid *oidp, int *oid, size_t nlen, int flags)
{
int error, xflag, oflag, Nflag, nflag;
size_t len;
xflag = flags & DB_SYSCTL_HEX;
oflag = flags & DB_SYSCTL_OPAQUE;
nflag = flags & DB_SYSCTL_VALUE_ONLY;
Nflag = flags & DB_SYSCTL_NAME_ONLY;
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_OPAQUE &&
(!xflag && !oflag))
return (0);
if (Nflag) {
db_show_oid_name(oid, nlen);
error = 0;
goto out;
}
if (!nflag) {
db_show_oid_name(oid, nlen);
db_printf(": ");
}
if ((flags & DB_SYSCTL_SAFE_ONLY) && !db_oid_safe(oidp)) {
db_printf("Skipping, unsafe to print while recursing.");
error = 0;
goto out;
}
/* Try once, and ask about the size */
len = 0;
error = db_sysctl(oidp, oid, nlen,
NULL, NULL, &len, flags);
if (error)
goto out;
if (!g_ddb_sysctl_printed)
/* Lie about the size */
error = db_sysctl(oidp, oid, nlen,
(void *) 1, &len, NULL, flags);
out:
db_printf("\n");
return (error);
}
/*
* Show all sysctls under a specific OID
* Compare to sysctl_all from sbin/sysctl/sysctl.c
*/
static int
db_show_sysctl_all(int *oid, size_t len, int flags)
{
struct sysctl_oid *oidp;
int qoid[CTL_MAXNAME + 2], next[CTL_MAXNAME];
size_t nlen;
qoid[0] = CTL_SYSCTL;
qoid[1] = CTL_SYSCTL_NEXT;
if (len) {
nlen = len;
memcpy(&qoid[2], oid, nlen * sizeof(int));
} else {
nlen = 1;
qoid[2] = CTL_KERN;
}
for (;;) {
int error;
size_t nextsize = sizeof(next);
error = kernel_sysctl(kdb_thread, qoid, nlen + 2,
next, &nextsize, NULL, 0, &nlen, 0);
if (error != 0) {
if (error == ENOENT)
return (0);
else
db_error("sysctl(next)");
}
nlen /= sizeof(int);
if (nlen < (unsigned int)len)
return (0);
if (memcmp(&oid[0], &next[0], len * sizeof(int)) != 0)
return (0);
/* Find the OID in question */
error = sysctl_find_oid(next, nlen, &oidp, NULL, NULL);
if (error)
return (error);
(void)db_show_oid(oidp, next, nlen, flags | DB_SYSCTL_SAFE_ONLY);
if (db_pager_quit)
return (0);
memcpy(&qoid[2 + len], &next[len], (nlen - len) * sizeof(int));
}
}
/*
* Show a sysctl by its user facing string
*/
static int
db_sysctlbyname(const char *name, int flags)
{
struct sysctl_oid *oidp;
int oid[CTL_MAXNAME];
int error, nlen;
error = name2oid(name, oid, &nlen, &oidp);
if (error) {
return (error);
}
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
db_show_sysctl_all(oid, nlen, flags);
} else {
error = db_show_oid(oidp, oid, nlen, flags);
}
return (error);
}
static void
db_sysctl_cmd_usage(void)
{
db_printf(
" sysctl [/Nnox] <sysctl> \n"
" \n"
" <sysctl> The name of the sysctl to show. \n"
" \n"
" Show a sysctl by hooking into SYSCTL_IN and SYSCTL_OUT. \n"
" This will work for most sysctls, but should not be used \n"
" with sysctls that are known to malloc. \n"
" \n"
" While recursing any \"unsafe\" sysctls will be skipped. \n"
" Call sysctl directly on the sysctl to try printing the \n"
" skipped sysctl. This is unsafe and may make the ddb \n"
" session unusable. \n"
" \n"
" Arguments: \n"
" /N Display only the name of the sysctl. \n"
" /n Display only the value of the sysctl. \n"
" /o Display opaque values. \n"
" /x Display the sysctl in hex. \n"
" \n"
"For example: \n"
"sysctl vm.v_free_min \n"
"vn.v_free_min: 12669 \n"
);
}
/*
* Show a specific sysctl similar to sysctl (8).
*/
DB_COMMAND_FLAGS(sysctl, db_sysctl_cmd, CS_OWN)
{
char name[TOK_STRING_SIZE];
int error, i, t, flags;
/* Parse the modifiers */
t = db_read_token();
if (t == tSLASH || t == tMINUS) {
t = db_read_token();
if (t != tIDENT) {
db_printf("Bad modifier\n");
error = EINVAL;
goto out;
}
db_strcpy(modif, db_tok_string);
}
else {
db_unread_token(t);
modif[0] = '\0';
}
flags = 0;
for (i = 0; i < nitems(db_sysctl_modifs); i++) {
if (strchr(modif, db_sysctl_modifs[i])) {
flags |= db_sysctl_modif_values[i];
}
}
/* Parse the sysctl names */
t = db_read_token();
if (t != tIDENT) {
db_printf("Need sysctl name\n");
error = EINVAL;
goto out;
}
/* Copy the name into a temporary buffer */
db_strcpy(name, db_tok_string);
/* Ensure there is no trailing cruft */
t = db_read_token();
if (t != tEOL) {
db_printf("Unexpected sysctl argument\n");
error = EINVAL;
goto out;
}
error = db_sysctlbyname(name, flags);
if (error == ENOENT) {
db_printf("unknown oid: '%s'\n", db_tok_string);
goto out;
} else if (error) {
db_printf("%s: error: %d\n", db_tok_string, error);
goto out;
}
out:
/* Ensure we eat all of our text */
db_flush_lex();
if (error == EINVAL) {
db_sysctl_cmd_usage();
}
}
#endif /* DDB */
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