freebsd-skq/sys/kern/kern_sysctl.c
truckman dd733c95bc Make a temporary copy of the output data in the generic sysctl handlers
so that the data is less likely to be inconsistent if SYSCTL_OUT() blocks.
If the data is large, wire the output buffer instead.

This is somewhat less than optimal, since the handler could skip the copy
if it knew that the data was static.

If the data is dynamic, we are still not guaranteed to get a consistent
copy since another processor could change the data while the copy is in
progress because the data is not locked.  This problem could be solved if
the generic handlers had the ability to grab the proper lock before the
copy and release it afterwards.

This may duplicate work done in other sysctl handlers in the kernel which
also copy the data, possibly while a lock is held, before calling they call
a generic handler to output the data.  These handlers should probably call
SYSCTL_OUT() directly.
2002-07-28 21:06:14 +00:00

1478 lines
33 KiB
C

/*-
* 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
* $FreeBSD$
*/
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/sysproto.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");
/*
* Locking - this locks the sysctl tree in memory.
*/
static struct sx sysctllock;
#define SYSCTL_LOCK() sx_xlock(&sysctllock)
#define SYSCTL_UNLOCK() sx_xunlock(&sysctllock)
#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl sysctllock")
static int sysctl_root(SYSCTL_HANDLER_ARGS);
struct sysctl_oid_list sysctl__children; /* root list */
static struct sysctl_oid *
sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
{
struct sysctl_oid *oidp;
SLIST_FOREACH(oidp, list, oid_link) {
if (strcmp(oidp->oid_name, name) == 0) {
return (oidp);
}
}
return (NULL);
}
/*
* Initialization of the MIB tree.
*
* Order by number in each list.
*/
void
sysctl_register_oid(struct sysctl_oid *oidp)
{
struct sysctl_oid_list *parent = oidp->oid_parent;
struct sysctl_oid *p;
struct sysctl_oid *q;
/*
* First check if another oid with the same name already
* exists in the parent's list.
*/
p = sysctl_find_oidname(oidp->oid_name, parent);
if (p != NULL) {
if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
p->oid_refcnt++;
return;
} else {
printf("can't re-use a leaf (%s)!\n", p->oid_name);
return;
}
}
/*
* If this oid has a number OID_AUTO, give it a number which
* is greater than any current oid.
* NOTE: DO NOT change the starting value here, change it in
* <sys/sysctl.h>, and make sure it is at least 256 to
* accomodate e.g. net.inet.raw as a static sysctl node.
*/
if (oidp->oid_number == OID_AUTO) {
static int newoid = CTL_AUTO_START;
oidp->oid_number = newoid++;
if (newoid == 0x7fffffff)
panic("out of oids");
}
#if 0
else if (oidp->oid_number >= CTL_AUTO_START) {
/* do not panic; this happens when unregistering sysctl sets */
printf("static sysctl oid too high: %d", oidp->oid_number);
}
#endif
/*
* Insert the oid into the parent's list in order.
*/
q = NULL;
SLIST_FOREACH(p, parent, oid_link) {
if (oidp->oid_number < p->oid_number)
break;
q = p;
}
if (q)
SLIST_INSERT_AFTER(q, oidp, oid_link);
else
SLIST_INSERT_HEAD(parent, oidp, oid_link);
}
void
sysctl_unregister_oid(struct sysctl_oid *oidp)
{
SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link);
}
/* 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);
}
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...
*/
TAILQ_FOREACH(e, clist, link) {
error = sysctl_remove_oid(e->entry, 0, 0);
if (error)
break;
}
/*
* Restore deregistered entries, either from the end,
* or from the place where error occured.
* 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)
return(EBUSY);
/* Now really delete the entries */
e = TAILQ_FIRST(clist);
while (e != NULL) {
e1 = TAILQ_NEXT(e, link);
error = sysctl_remove_oid(e->entry, 1, 0);
if (error)
panic("sysctl_remove_oid: corrupt tree, entry: %s",
e->entry->oid_name);
free(e, M_SYSCTLOID);
e = e1;
}
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;
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;
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);
e = sysctl_ctx_entry_find(clist, oidp);
if (e != NULL) {
TAILQ_REMOVE(clist, e, link);
free(e, M_SYSCTLOID);
return (0);
} else
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)
{
struct sysctl_oid *p;
int error;
if (oidp == NULL)
return(EINVAL);
if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
printf("can't remove non-dynamic nodes!\n");
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) {
SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
if (!recurse)
return (ENOTEMPTY);
error = sysctl_remove_oid(p, del, recurse);
if (error)
return (error);
}
if (del)
free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
}
}
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) {
if (oidp->descr)
free((void *)(uintptr_t)(const void *)oidp->descr, M_SYSCTLOID);
free((void *)(uintptr_t)(const void *)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, int arg2,
int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
{
struct sysctl_oid *oidp;
ssize_t len;
char *newname;
/* You have to hook up somewhere.. */
if (parent == NULL)
return(NULL);
/* Check if the node already exists, otherwise create it */
oidp = sysctl_find_oidname(name, parent);
if (oidp != NULL) {
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
oidp->oid_refcnt++;
/* Update the context */
if (clist != NULL)
sysctl_ctx_entry_add(clist, oidp);
return (oidp);
} else {
printf("can't re-use a leaf (%s)!\n", name);
return (NULL);
}
}
oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
oidp->oid_parent = parent;
SLIST_NEXT(oidp, oid_link) = NULL;
oidp->oid_number = number;
oidp->oid_refcnt = 1;
len = strlen(name);
newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
bcopy(name, newname, len + 1);
newname[len] = '\0';
oidp->oid_name = newname;
oidp->oid_handler = handler;
oidp->oid_kind = CTLFLAG_DYN | kind;
if ((kind & CTLTYPE) == CTLTYPE_NODE) {
/* Allocate space for children */
SYSCTL_CHILDREN(oidp) = malloc(sizeof(struct sysctl_oid_list),
M_SYSCTLOID, M_WAITOK);
SLIST_INIT(SYSCTL_CHILDREN(oidp));
} else {
oidp->oid_arg1 = arg1;
oidp->oid_arg2 = arg2;
}
oidp->oid_fmt = fmt;
if (descr) {
int len = strlen(descr) + 1;
oidp->descr = malloc(len, M_SYSCTLOID, M_WAITOK);
if (oidp->descr)
strcpy((char *)(uintptr_t)(const void *)oidp->descr, descr);
}
/* Update the context, if used */
if (clist != NULL)
sysctl_ctx_entry_add(clist, oidp);
/* Register this oid */
sysctl_register_oid(oidp);
return (oidp);
}
/*
* 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;
SYSCTL_INIT();
SET_FOREACH(oidp, sysctl_set)
sysctl_register_oid(*oidp);
}
SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
/*
* "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.
* {0,5,...} return the description the "..." OID.
*/
static void
sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
{
int k;
struct sysctl_oid *oidp;
SLIST_FOREACH(oidp, l, oid_link) {
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(
oidp->oid_arg1, i+2);
}
break;
case CTLTYPE_INT: printf(" Int\n"); break;
case CTLTYPE_STRING: printf(" String\n"); break;
case CTLTYPE_QUAD: printf(" Quad\n"); break;
case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
default: printf("\n");
}
}
}
static int
sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
{
int error;
error = suser(req->td);
if (error)
return error;
sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
return ENOENT;
}
SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_sysctl_debug, "-", "");
static int
sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
{
int *name = (int *) arg1;
u_int namelen = arg2;
int error = 0;
struct sysctl_oid *oid;
struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
char buf[10];
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)
return (error);
namelen--;
name++;
continue;
}
lsp2 = 0;
SLIST_FOREACH(oid, lsp, oid_link) {
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)
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;
}
return (SYSCTL_OUT(req, "", 1));
}
SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
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;
SLIST_FOREACH(oidp, lsp, oid_link) {
*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 (!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;
}
static int
sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
{
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];
i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
if (i)
return ENOENT;
error = SYSCTL_OUT(req, newoid, j * sizeof (int));
return (error);
}
SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
static int
name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
{
int i;
struct sysctl_oid *oidp;
struct sysctl_oid_list *lsp = &sysctl__children;
char *p;
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';
oidp = SLIST_FIRST(lsp);
while (oidp && *len < CTL_MAXNAME) {
if (strcmp(name, oidp->oid_name)) {
oidp = SLIST_NEXT(oidp, oid_link);
continue;
}
*oid++ = oidp->oid_number;
(*len)++;
if (!i) {
if (oidpp)
*oidpp = oidp;
return (0);
}
if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
break;
if (oidp->oid_handler)
break;
lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
oidp = SLIST_FIRST(lsp);
name = p+1;
for (p = name; *p && *p != '.'; p++)
;
i = *p;
if (i == '.')
*p = '\0';
}
return ENOENT;
}
static int
sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
{
char *p;
int error, oid[CTL_MAXNAME], len;
struct sysctl_oid *op = 0;
if (!req->newlen)
return ENOENT;
if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
return (ENAMETOOLONG);
p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
error = SYSCTL_IN(req, p, req->newlen);
if (error) {
free(p, M_SYSCTL);
return (error);
}
p [req->newlen] = '\0';
error = name2oid(p, oid, &len, &op);
free(p, M_SYSCTL);
if (error)
return (error);
error = SYSCTL_OUT(req, oid, len * sizeof *oid);
return (error);
}
SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0,
sysctl_sysctl_name2oid, "I", "");
static int
sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
int error;
error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
if (error)
return (error);
if (!oid->oid_fmt)
return (ENOENT);
error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
if (error)
return (error);
error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
return (error);
}
SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
static int
sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
int error;
error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
if (error)
return (error);
if (!oid->descr)
return (ENOENT);
error = SYSCTL_OUT(req, oid->descr, strlen(oid->descr) + 1);
return (error);
}
SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
/*
* 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(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);
}
/*
* Handle a long, signed or unsigned. arg1 points to it.
*/
int
sysctl_handle_long(SYSCTL_HANDLER_ARGS)
{
int error = 0;
long tmpout;
/*
* Attempt to get a coherent snapshot by making a copy of the data.
*/
if (!arg1)
return (EINVAL);
tmpout = *(long *)arg1;
error = SYSCTL_OUT(req, &tmpout, sizeof(long));
if (error || !req->newptr)
return (error);
error = SYSCTL_IN(req, arg1, sizeof(long));
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)
{
int error=0;
char *tmparg;
size_t outlen;
/*
* Attempt to get a coherent snapshot by copying to a
* temporary kernel buffer.
*/
retry:
outlen = strlen((char *)arg1)+1;
tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
strncpy(tmparg, (char *)arg1, outlen);
if (tmparg[outlen-1] != '\0') {
free(tmparg, M_SYSCTLTMP);
goto retry;
}
error = SYSCTL_OUT(req, tmparg, outlen);
free(tmparg, M_SYSCTLTMP);
if (error || !req->newptr)
return (error);
if ((req->newlen - req->newidx) >= arg2) {
error = EINVAL;
} else {
arg2 = (req->newlen - req->newidx);
error = SYSCTL_IN(req, arg1, arg2);
((char *)arg1)[arg2] = '\0';
}
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;
void *tmparg;
/*
* Attempt to get a coherent snapshot, either by wiring the
* user space buffer or copying to a temporary kernel buffer
* depending on the size of the data.
*/
if (arg2 > PAGE_SIZE) {
sysctl_wire_old_buffer(req, arg2);
error = SYSCTL_OUT(req, arg1, arg2);
} else {
tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
bcopy(arg1, tmparg, arg2);
error = SYSCTL_OUT(req, tmparg, arg2);
free(tmparg, M_SYSCTLTMP);
}
if (error || !req->newptr)
return (error);
error = SYSCTL_IN(req, arg1, arg2);
return (error);
}
/*
* 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((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 error = 0;
struct sysctl_req req;
bzero(&req, sizeof req);
req.td = td;
if (oldlenp) {
req.oldlen = *oldlenp;
}
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 = 1;
SYSCTL_LOCK();
error = sysctl_root(0, name, namelen, &req);
if (req.lock == 2)
vsunlock(req.oldptr, req.oldlen);
SYSCTL_UNLOCK();
if (error && error != ENOMEM)
return (error);
if (retval) {
if (req.oldptr && req.oldidx > req.oldlen)
*retval = req.oldlen;
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 oid[CTL_MAXNAME];
size_t oidlen, plen;
int error;
oid[0] = 0; /* sysctl internal magic */
oid[1] = 3; /* name2oid */
oidlen = sizeof(oid);
error = kernel_sysctl(td, oid, 2, oid, &oidlen,
(void *)name, strlen(name), &plen);
if (error)
return (error);
error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
new, newlen, retval);
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->lock == 1 && req->oldptr) {
vslock(req->oldptr, req->oldlen);
req->lock = 2;
}
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)
error = copyout(p, (char *)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((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.
*
* XXX - The len parameter is currently ignored due to the lack of
* a place to save it in the sysctl_req structure so that the matching
* amount of memory can be unwired in the sysctl exit code.
*/
void
sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
{
if (req->lock == 1 && req->oldptr && req->oldfunc == sysctl_old_user) {
vslock(req->oldptr, req->oldlen);
req->lock = 2;
}
}
int
sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
int *nindx, struct sysctl_req *req)
{
struct sysctl_oid *oid;
int indx;
oid = SLIST_FIRST(&sysctl__children);
indx = 0;
while (oid && indx < CTL_MAXNAME) {
if (oid->oid_number == name[indx]) {
indx++;
if (oid->oid_kind & CTLFLAG_NOLOCK)
req->lock = 0;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
if (oid->oid_handler != NULL ||
indx == namelen) {
*noid = oid;
if (nindx != NULL)
*nindx = indx;
return (0);
}
oid = SLIST_FIRST(
(struct sysctl_oid_list *)oid->oid_arg1);
} else if (indx == namelen) {
*noid = oid;
if (nindx != NULL)
*nindx = indx;
return (0);
} else {
return (ENOTDIR);
}
} else {
oid = SLIST_NEXT(oid, oid_link);
}
}
return (ENOENT);
}
/*
* Traverse our tree, and find the right node, execute whatever it points
* to, and return the resulting error code.
*/
int
sysctl_root(SYSCTL_HANDLER_ARGS)
{
struct sysctl_oid *oid;
int error, indx;
error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
if (error)
return (error);
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)
return (EISDIR);
}
/* Is this sysctl writable? */
if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
return (EPERM);
KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
/* Is this sysctl sensitive to securelevels? */
if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
error = securelevel_gt(req->td->td_ucred, 0);
if (error)
return (error);
}
/* Is this sysctl writable by only privileged users? */
if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
int flags;
if (oid->oid_kind & CTLFLAG_PRISON)
flags = PRISON_ROOT;
else
flags = 0;
error = suser_cred(req->td->td_ucred, flags);
if (error)
return (error);
}
if (!oid->oid_handler)
return EINVAL;
if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE)
error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx,
req);
else
error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2,
req);
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
/*
* MPSAFE
*/
int
__sysctl(struct thread *td, struct sysctl_args *uap)
{
int error, 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);
mtx_lock(&Giant);
error = userland_sysctl(td, name, uap->namelen,
uap->old, uap->oldlenp, 0,
uap->new, uap->newlen, &j);
if (error && error != ENOMEM)
goto done2;
if (uap->oldlenp) {
int i = copyout(&j, uap->oldlenp, sizeof(j));
if (i)
error = i;
}
done2:
mtx_unlock(&Giant);
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, void *new, size_t newlen, size_t *retval)
{
int error = 0;
struct sysctl_req req, req2;
bzero(&req, sizeof req);
req.td = td;
if (oldlenp) {
if (inkernel) {
req.oldlen = *oldlenp;
} else {
error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
if (error)
return (error);
}
}
if (old) {
if (!useracc(old, req.oldlen, VM_PROT_WRITE))
return (EFAULT);
req.oldptr= old;
}
if (new != NULL) {
if (!useracc(new, req.newlen, VM_PROT_READ))
return (EFAULT);
req.newlen = newlen;
req.newptr = new;
}
req.oldfunc = sysctl_old_user;
req.newfunc = sysctl_new_user;
req.lock = 1;
SYSCTL_LOCK();
do {
req2 = req;
error = sysctl_root(0, name, namelen, &req2);
} while (error == EAGAIN);
req = req2;
if (req.lock == 2)
vsunlock(req.oldptr, req.oldlen);
SYSCTL_UNLOCK();
if (error && error != ENOMEM)
return (error);
if (retval) {
if (req.oldptr && req.oldidx > req.oldlen)
*retval = req.oldlen;
else
*retval = req.oldidx;
}
return (error);
}
#ifdef COMPAT_43
#include <sys/socket.h>
#include <vm/vm_param.h>
#define KINFO_PROC (0<<8)
#define KINFO_RT (1<<8)
#define KINFO_VNODE (2<<8)
#define KINFO_FILE (3<<8)
#define KINFO_METER (4<<8)
#define KINFO_LOADAVG (5<<8)
#define KINFO_CLOCKRATE (6<<8)
/* Non-standard BSDI extension - only present on their 4.3 net-2 releases */
#define KINFO_BSDI_SYSINFO (101<<8)
/*
* XXX this is bloat, but I hope it's better here than on the potentially
* limited kernel stack... -Peter
*/
static struct {
int bsdi_machine; /* "i386" on BSD/386 */
/* ^^^ this is an offset to the string, relative to the struct start */
char *pad0;
long pad1;
long pad2;
long pad3;
u_long pad4;
u_long pad5;
u_long pad6;
int bsdi_ostype; /* "BSD/386" on BSD/386 */
int bsdi_osrelease; /* "1.1" on BSD/386 */
long pad7;
long pad8;
char *pad9;
long pad10;
long pad11;
int pad12;
long pad13;
quad_t pad14;
long pad15;
struct timeval pad16;
/* we dont set this, because BSDI's uname used gethostname() instead */
int bsdi_hostname; /* hostname on BSD/386 */
/* the actual string data is appended here */
} bsdi_si;
/*
* this data is appended to the end of the bsdi_si structure during copyout.
* The "char *" offsets are relative to the base of the bsdi_si struct.
* This contains "FreeBSD\02.0-BUILT-nnnnnn\0i386\0", and these strings
* should not exceed the length of the buffer here... (or else!! :-)
*/
static char bsdi_strings[80]; /* It had better be less than this! */
#ifndef _SYS_SYSPROTO_H_
struct getkerninfo_args {
int op;
char *where;
size_t *size;
int arg;
};
#endif
/*
* MPSAFE
*/
int
ogetkerninfo(struct thread *td, struct getkerninfo_args *uap)
{
int error, name[6];
size_t size;
u_int needed = 0;
mtx_lock(&Giant);
switch (uap->op & 0xff00) {
case KINFO_RT:
name[0] = CTL_NET;
name[1] = PF_ROUTE;
name[2] = 0;
name[3] = (uap->op & 0xff0000) >> 16;
name[4] = uap->op & 0xff;
name[5] = uap->arg;
error = userland_sysctl(td, name, 6, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_VNODE:
name[0] = CTL_KERN;
name[1] = KERN_VNODE;
error = userland_sysctl(td, name, 2, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_PROC:
name[0] = CTL_KERN;
name[1] = KERN_PROC;
name[2] = uap->op & 0xff;
name[3] = uap->arg;
error = userland_sysctl(td, name, 4, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_FILE:
name[0] = CTL_KERN;
name[1] = KERN_FILE;
error = userland_sysctl(td, name, 2, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_METER:
name[0] = CTL_VM;
name[1] = VM_METER;
error = userland_sysctl(td, name, 2, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_LOADAVG:
name[0] = CTL_VM;
name[1] = VM_LOADAVG;
error = userland_sysctl(td, name, 2, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_CLOCKRATE:
name[0] = CTL_KERN;
name[1] = KERN_CLOCKRATE;
error = userland_sysctl(td, name, 2, uap->where, uap->size,
0, 0, 0, &size);
break;
case KINFO_BSDI_SYSINFO: {
/*
* this is pretty crude, but it's just enough for uname()
* from BSDI's 1.x libc to work.
*
* *size gives the size of the buffer before the call, and
* the amount of data copied after a successful call.
* If successful, the return value is the amount of data
* available, which can be larger than *size.
*
* BSDI's 2.x product apparently fails with ENOMEM if *size
* is too small.
*/
u_int left;
char *s;
bzero((char *)&bsdi_si, sizeof(bsdi_si));
bzero(bsdi_strings, sizeof(bsdi_strings));
s = bsdi_strings;
bsdi_si.bsdi_ostype = (s - bsdi_strings) + sizeof(bsdi_si);
strcpy(s, ostype);
s += strlen(s) + 1;
bsdi_si.bsdi_osrelease = (s - bsdi_strings) + sizeof(bsdi_si);
strcpy(s, osrelease);
s += strlen(s) + 1;
bsdi_si.bsdi_machine = (s - bsdi_strings) + sizeof(bsdi_si);
strcpy(s, machine);
s += strlen(s) + 1;
needed = sizeof(bsdi_si) + (s - bsdi_strings);
if ((uap->where == NULL) || (uap->size == NULL)) {
/* process is asking how much buffer to supply.. */
size = needed;
error = 0;
break;
}
if ((error = copyin(uap->size, &size, sizeof(size))) != 0)
break;
/* if too much buffer supplied, trim it down */
if (size > needed)
size = needed;
/* how much of the buffer is remaining */
left = size;
if ((error = copyout((char *)&bsdi_si, uap->where, left)) != 0)
break;
/* is there any point in continuing? */
if (left > sizeof(bsdi_si)) {
left -= sizeof(bsdi_si);
error = copyout(&bsdi_strings,
uap->where + sizeof(bsdi_si), left);
}
break;
}
default:
error = EOPNOTSUPP;
break;
}
if (error == 0) {
td->td_retval[0] = needed ? needed : size;
if (uap->size) {
error = copyout(&size, uap->size, sizeof(size));
}
}
mtx_unlock(&Giant);
return (error);
}
#endif /* COMPAT_43 */