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kern_sysctl.c
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kern_sysctl.c
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/* $NetBSD: kern_sysctl.c,v 1.269 2023/04/09 09:18:09 riastradh Exp $ */
/*-
* Copyright (c) 2003, 2007, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Brown.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* 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.
*
* 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.
*
* @(#)kern_sysctl.c 8.9 (Berkeley) 5/20/95
*/
/*
* sysctl system call.
*/
#define __COMPAT_SYSCTL
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.269 2023/04/09 09:18:09 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_defcorename.h"
#endif
#include "ksyms.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/buf.h>
#include <sys/cprng.h>
#include <sys/kauth.h>
#include <sys/ksyms.h>
#include <sys/ktrace.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/once.h>
#include <sys/rndsource.h>
#include <sys/syscallargs.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <crypto/blake2/blake2s.h>
#define MAXDESCLEN 1024
MALLOC_DEFINE(M_SYSCTLNODE, "sysctlnode", "sysctl node structures");
MALLOC_DEFINE(M_SYSCTLDATA, "sysctldata", "misc sysctl data");
static int sysctl_mmap(SYSCTLFN_PROTO);
static int sysctl_alloc(struct sysctlnode *, int);
static int sysctl_realloc(struct sysctlnode *);
static int sysctl_cvt_in(struct lwp *, int *, const void *, size_t,
struct sysctlnode *);
static int sysctl_cvt_out(struct lwp *, int, const struct sysctlnode *,
void *, size_t, size_t *);
static int sysctl_log_add(struct sysctllog **, const struct sysctlnode *);
static int sysctl_log_realloc(struct sysctllog *);
typedef void sysctl_setup_func(struct sysctllog **);
#ifdef SYSCTL_DEBUG
#define DPRINTF(a) printf a
#else
#define DPRINTF(a)
#endif
struct sysctllog {
const struct sysctlnode *log_root;
int *log_num;
int log_size, log_left;
};
/*
* the "root" of the new sysctl tree
*/
struct sysctlnode sysctl_root = {
.sysctl_flags = SYSCTL_VERSION|
CTLFLAG_ROOT|CTLFLAG_READWRITE|
CTLTYPE_NODE,
.sysctl_num = 0,
.sysctl_size = sizeof(struct sysctlnode),
.sysctl_name = "(root)",
};
/*
* link set of functions that add nodes at boot time (see also
* sysctl_buildtree())
*/
__link_set_decl(sysctl_funcs, sysctl_setup_func);
/*
* The `sysctl_treelock' is intended to serialize access to the sysctl
* tree. XXX This has serious problems; allocating memory and
* copying data out with the lock held is insane.
*/
krwlock_t sysctl_treelock;
kmutex_t sysctl_file_marker_lock;
/*
* Attributes stored in the kernel.
*/
char hostname[MAXHOSTNAMELEN];
int hostnamelen;
char domainname[MAXHOSTNAMELEN];
int domainnamelen;
long hostid;
#ifndef DEFCORENAME
#define DEFCORENAME "%n.core"
#endif
char defcorename[MAXPATHLEN] = DEFCORENAME;
/*
* ********************************************************************
* Section 0: Some simple glue
* ********************************************************************
* By wrapping copyin(), copyout(), and copyinstr() like this, we can
* stop caring about who's calling us and simplify some code a bunch.
* ********************************************************************
*/
int
sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
{
int error;
if (l != NULL) {
error = copyin(uaddr, kaddr, len);
ktrmibio(-1, UIO_WRITE, uaddr, len, error);
} else {
error = kcopy(uaddr, kaddr, len);
}
return error;
}
int
sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
{
int error;
if (l != NULL) {
error = copyout(kaddr, uaddr, len);
ktrmibio(-1, UIO_READ, uaddr, len, error);
} else {
error = kcopy(kaddr, uaddr, len);
}
return error;
}
int
sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
size_t len, size_t *done)
{
int error;
if (l != NULL) {
error = copyinstr(uaddr, kaddr, len, done);
ktrmibio(-1, UIO_WRITE, uaddr, len, error);
} else {
error = copystr(uaddr, kaddr, len, done);
}
return error;
}
/*
* ********************************************************************
* Initialize sysctl subsystem.
* ********************************************************************
*/
void
sysctl_init(void)
{
sysctl_setup_func *const *sysctl_setup;
rw_init(&sysctl_treelock);
/*
* dynamic mib numbers start here
*/
sysctl_root.sysctl_num = CREATE_BASE;
sysctl_basenode_init();
__link_set_foreach(sysctl_setup, sysctl_funcs) {
(**sysctl_setup)(NULL);
}
mutex_init(&sysctl_file_marker_lock, MUTEX_DEFAULT, IPL_NONE);
}
/*
* Setting this means no more permanent nodes can be added,
* trees that claim to be readonly at the root now are, and if
* the main tree is readonly, *everything* is.
*
* Also starts up the PRNG used for the "random" sysctl: it's
* better to start it later than sooner.
*
* Call this at the end of kernel init.
*/
void
sysctl_finalize(void)
{
sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
}
/*
* ********************************************************************
* The main native sysctl system call itself.
* ********************************************************************
*/
int
sys___sysctl(struct lwp *l, const struct sys___sysctl_args *uap, register_t *retval)
{
/* {
syscallarg(const int *) name;
syscallarg(u_int) namelen;
syscallarg(void *) old;
syscallarg(size_t *) oldlenp;
syscallarg(const void *) new;
syscallarg(size_t) newlen;
} */
int error, nerror, name[CTL_MAXNAME];
size_t oldlen, savelen, *oldlenp;
/*
* get oldlen
*/
oldlen = 0;
oldlenp = SCARG(uap, oldlenp);
if (oldlenp != NULL) {
error = copyin(oldlenp, &oldlen, sizeof(oldlen));
if (error)
return (error);
}
savelen = oldlen;
/*
* top-level sysctl names may or may not be non-terminal, but
* we don't care
*/
if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
return (EINVAL);
error = copyin(SCARG(uap, name), &name,
SCARG(uap, namelen) * sizeof(int));
if (error)
return (error);
ktrmib(name, SCARG(uap, namelen));
sysctl_lock(SCARG(uap, newv) != NULL);
/*
* do sysctl work (NULL means main built-in default tree)
*/
error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
SCARG(uap, oldv), &oldlen,
SCARG(uap, newv), SCARG(uap, newlen),
&name[0], l, NULL);
/*
* release the sysctl lock
*/
sysctl_unlock();
/*
* set caller's oldlen to new value even in the face of an
* error (if this gets an error and they didn't have one, they
* get this one)
*/
if (oldlenp) {
nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
if (error == 0)
error = nerror;
}
/*
* if the only problem is that we weren't given enough space,
* that's an ENOMEM error
*/
if (error == 0 && SCARG(uap, oldv) != NULL && savelen < oldlen)
error = ENOMEM;
return (error);
}
/*
* ********************************************************************
* Section 1: How the tree is used
* ********************************************************************
* Implementations of sysctl for emulations should typically need only
* these three functions in this order: lock the tree, dispatch
* request into it, unlock the tree.
* ********************************************************************
*/
void
sysctl_lock(bool write)
{
if (write) {
rw_enter(&sysctl_treelock, RW_WRITER);
curlwp->l_pflag |= LP_SYSCTLWRITE;
} else {
rw_enter(&sysctl_treelock, RW_READER);
curlwp->l_pflag &= ~LP_SYSCTLWRITE;
}
}
void
sysctl_relock(void)
{
if ((curlwp->l_pflag & LP_SYSCTLWRITE) != 0) {
rw_enter(&sysctl_treelock, RW_WRITER);
} else {
rw_enter(&sysctl_treelock, RW_READER);
}
}
/*
* ********************************************************************
* the main sysctl dispatch routine. scans the given tree and picks a
* function to call based on what it finds.
* ********************************************************************
*/
int
sysctl_dispatch(SYSCTLFN_ARGS)
{
int error;
sysctlfn fn;
int ni;
KASSERT(rw_lock_held(&sysctl_treelock));
if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
error = EINVAL;
goto out;
}
fn = NULL;
error = sysctl_locate(l, name, namelen, &rnode, &ni);
if (rnode->sysctl_func != NULL) {
/*
* the node we ended up at has a function, so call it. it can
* hand off to query or create if it wants to.
*/
fn = rnode->sysctl_func;
} else if (error == 0) {
/*
* we found the node they were looking for, so do a lookup.
*/
fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
/*
* prospective parent node found, but the terminal node was
* not. generic operations associate with the parent.
*/
switch (name[ni]) {
case CTL_QUERY:
fn = sysctl_query;
break;
case CTL_CREATE:
#if NKSYMS > 0
case CTL_CREATESYM:
#endif /* NKSYMS > 0 */
if (newp == NULL) {
error = EINVAL;
break;
}
KASSERT(rw_write_held(&sysctl_treelock));
fn = (sysctlfn)sysctl_create; /* we own the rnode */
break;
case CTL_DESTROY:
if (newp == NULL) {
error = EINVAL;
break;
}
KASSERT(rw_write_held(&sysctl_treelock));
fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
break;
case CTL_MMAP:
fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
break;
case CTL_DESCRIBE:
fn = sysctl_describe;
break;
default:
error = EOPNOTSUPP;
break;
}
}
/*
* after all of that, maybe we found someone who knows how to
* get us what we want?
*/
if (fn != NULL)
error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
newp, newlen, name, l, rnode);
else if (error == 0)
error = EOPNOTSUPP;
out:
return (error);
}
/*
* ********************************************************************
* Releases the tree lock.
* ********************************************************************
*/
void
sysctl_unlock(void)
{
rw_exit(&sysctl_treelock);
}
/*
* ********************************************************************
* Section 2: The main tree interfaces
* ********************************************************************
* This is how sysctl_dispatch() does its work, and you can too, by
* calling these routines from helpers (though typically only
* sysctl_lookup() will be used). The tree MUST BE LOCKED when these
* are called.
* ********************************************************************
*/
/*
* sysctl_locate -- Finds the node matching the given mib under the
* given tree (via rv). If no tree is given, we fall back to the
* native tree. The current process (via l) is used for access
* control on the tree (some nodes may be traversable only by root) and
* on return, nip will show how many numbers in the mib were consumed.
*/
int
sysctl_locate(struct lwp *l, const int *name, u_int namelen,
const struct sysctlnode **rnode, int *nip)
{
const struct sysctlnode *node, *pnode;
int tn, si, ni, error, alias;
KASSERT(rw_lock_held(&sysctl_treelock));
/*
* basic checks and setup
*/
if (*rnode == NULL)
*rnode = &sysctl_root;
if (nip)
*nip = 0;
if (namelen == 0)
return (0);
/*
* search starts from "root"
*/
pnode = *rnode;
if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
printf("sysctl_locate: pnode %p wrong version\n", pnode);
return (EINVAL);
}
node = pnode->sysctl_child;
error = 0;
/*
* scan for node to which new node should be attached
*/
for (ni = 0; ni < namelen; ni++) {
/*
* walked off bottom of tree
*/
if (node == NULL) {
if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
error = ENOENT;
else
error = ENOTDIR;
break;
}
/*
* can anyone traverse this node or only root?
*/
if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
(error = kauth_authorize_system(l->l_cred,
KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
NULL, NULL, NULL)) != 0)
return (error);
/*
* find a child node with the right number
*/
tn = name[ni];
alias = 0;
si = 0;
/*
* Note: ANYNUMBER only matches positive integers.
* Since ANYNUMBER is only permitted on single-node
* sub-trees (eg proc), check before the loop and skip
* it if we can.
*/
if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
goto foundit;
for (; si < pnode->sysctl_clen; si++) {
if (node[si].sysctl_num == tn) {
if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
if (alias++ == 4)
break;
else {
tn = node[si].sysctl_alias;
si = -1;
}
} else
goto foundit;
}
}
/*
* if we ran off the end, it obviously doesn't exist
*/
error = ENOENT;
break;
/*
* so far so good, move on down the line
*/
foundit:
pnode = &node[si];
if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
node = node[si].sysctl_child;
else
node = NULL;
}
*rnode = pnode;
if (nip)
*nip = ni;
return (error);
}
/*
* sysctl_query -- The auto-discovery engine. Copies out the structs
* describing nodes under the given node and handles overlay trees.
*/
int
sysctl_query(SYSCTLFN_ARGS)
{
int error, ni, elim, v;
size_t out, left, t;
const struct sysctlnode *enode, *onode;
struct sysctlnode qnode;
KASSERT(rw_lock_held(&sysctl_treelock));
if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
printf("sysctl_query: rnode %p wrong version\n", rnode);
return (EINVAL);
}
if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
return (ENOTDIR);
if (namelen != 1 || name[0] != CTL_QUERY)
return (EINVAL);
error = 0;
out = 0;
left = *oldlenp;
elim = 0;
enode = NULL;
/*
* translate the given request to a current node
*/
error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
if (error)
return (error);
/*
* if the request specifies a version, check it
*/
if (qnode.sysctl_ver != 0) {
enode = rnode;
if (qnode.sysctl_ver != enode->sysctl_ver &&
qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
return (EINVAL);
}
/*
* process has overlay tree
*/
if (l && l->l_proc->p_emul->e_sysctlovly) {
enode = l->l_proc->p_emul->e_sysctlovly;
elim = (name - oname);
error = sysctl_locate(l, oname, elim, &enode, NULL);
if (error == 0) {
/* ah, found parent in overlay */
elim = enode->sysctl_clen;
enode = enode->sysctl_child;
} else {
error = 0;
elim = 0;
enode = NULL;
}
}
for (ni = 0; ni < rnode->sysctl_clen; ni++) {
onode = &rnode->sysctl_child[ni];
if (enode && enode->sysctl_num == onode->sysctl_num) {
if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
onode = enode;
if (--elim > 0)
enode++;
else
enode = NULL;
}
error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
if (error)
return (error);
if (oldp != NULL)
oldp = (char*)oldp + t;
out += t;
left -= MIN(left, t);
}
/*
* overlay trees *MUST* be entirely consumed
*/
KASSERT(enode == NULL);
*oldlenp = out;
return (error);
}
/*
* sysctl_create -- Adds a node (the description of which is taken
* from newp) to the tree, returning a copy of it in the space pointed
* to by oldp. In the event that the requested slot is already taken
* (either by name or by number), the offending node is returned
* instead. Yes, this is complex, but we want to make sure everything
* is proper.
*/
#ifdef SYSCTL_DEBUG_CREATE
int _sysctl_create(SYSCTLFN_ARGS);
int
_sysctl_create(SYSCTLFN_ARGS)
#else
int
sysctl_create(SYSCTLFN_ARGS)
#endif
{
struct sysctlnode nnode, *node, *pnode;
int error, ni, at, nm, type, nsz, sz, flags, anum, v;
void *own;
KASSERT(rw_write_held(&sysctl_treelock));
error = 0;
own = NULL;
anum = -1;
if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
printf("sysctl_create: rnode %p wrong version\n", rnode);
return (EINVAL);
}
if (namelen != 1 || (name[namelen - 1] != CTL_CREATE
#if NKSYMS > 0
&& name[namelen - 1] != CTL_CREATESYM
#endif /* NKSYMS > 0 */
))
return (EINVAL);
/*
* processes can only add nodes at securelevel 0, must be
* root, and can't add nodes to a parent that's not writeable
*/
if (l != NULL) {
#ifndef SYSCTL_DISALLOW_CREATE
error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
KAUTH_REQ_SYSTEM_SYSCTL_ADD, NULL, NULL, NULL);
if (error)
return (error);
if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
#endif /* SYSCTL_DISALLOW_CREATE */
return (EPERM);
}
/*
* nothing can add a node if:
* we've finished initial set up of this tree and
* (the tree itself is not writeable or
* the entire sysctl system is not writeable)
*/
if ((sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_PERMANENT) &&
(!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
!(sysctl_root.sysctl_flags & CTLFLAG_READWRITE)))
return (EPERM);
/*
* it must be a "node", not a "int" or something
*/
if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
return (ENOTDIR);
if (rnode->sysctl_flags & CTLFLAG_ALIAS) {
printf("sysctl_create: attempt to add node to aliased "
"node %p\n", rnode);
return (EINVAL);
}
pnode = __UNCONST(rnode); /* we are adding children to this node */
if (newp == NULL)
return (EINVAL);
error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
if (error)
return (error);
/*
* nodes passed in don't *have* parents
*/
if (nnode.sysctl_parent != NULL)
return (EINVAL);
/*
* if we are indeed adding it, it should be a "good" name and
* number
*/
nm = nnode.sysctl_num;
#if NKSYMS > 0
if (nm == CTL_CREATESYM)
nm = CTL_CREATE;
#endif /* NKSYMS > 0 */
if (nm < 0 && nm != CTL_CREATE)
return (EINVAL);
/*
* the name can't start with a digit
*/
if (nnode.sysctl_name[0] >= '0' &&
nnode.sysctl_name[0] <= '9')
return (EINVAL);
/*
* the name must be only alphanumerics or - or _, longer than
* 0 bytes and less than SYSCTL_NAMELEN
*/
nsz = 0;
while (nsz < SYSCTL_NAMELEN && nnode.sysctl_name[nsz] != '\0') {
if ((nnode.sysctl_name[nsz] >= '0' &&
nnode.sysctl_name[nsz] <= '9') ||
(nnode.sysctl_name[nsz] >= 'A' &&
nnode.sysctl_name[nsz] <= 'Z') ||
(nnode.sysctl_name[nsz] >= 'a' &&
nnode.sysctl_name[nsz] <= 'z') ||
nnode.sysctl_name[nsz] == '-' ||
nnode.sysctl_name[nsz] == '_')
nsz++;
else
return (EINVAL);
}
if (nsz == 0 || nsz == SYSCTL_NAMELEN)
return (EINVAL);
/*
* various checks revolve around size vs type, etc
*/
type = SYSCTL_TYPE(nnode.sysctl_flags);
flags = SYSCTL_FLAGS(nnode.sysctl_flags);
sz = nnode.sysctl_size;
/*
* find out if there's a collision, and if so, let the caller
* know what they collided with
*/
node = pnode->sysctl_child;
at = 0;
if (node) {
if ((flags | node->sysctl_flags) & CTLFLAG_ANYNUMBER)
/* No siblings for a CTLFLAG_ANYNUMBER node */
return EINVAL;
for (ni = 0; ni < pnode->sysctl_clen; ni++) {
if (nm == node[ni].sysctl_num ||
strcmp(nnode.sysctl_name, node[ni].sysctl_name) == 0) {
/*
* ignore error here, since we
* are already fixed on EEXIST
*/
(void)sysctl_cvt_out(l, v, &node[ni], oldp,
*oldlenp, oldlenp);
return (EEXIST);
}
if (nm > node[ni].sysctl_num)
at++;
}
}
/*
* use sysctl_ver to add to the tree iff it hasn't changed
*/
if (nnode.sysctl_ver != 0) {
/*
* a specified value must match either the parent
* node's version or the root node's version
*/
if (nnode.sysctl_ver != sysctl_rootof(rnode)->sysctl_ver &&
nnode.sysctl_ver != rnode->sysctl_ver) {
return (EINVAL);
}
}
/*
* only the kernel can assign functions to entries
*/
if (l != NULL && nnode.sysctl_func != NULL)
return (EPERM);
/*
* only the kernel can create permanent entries, and only then
* before the kernel is finished setting itself up
*/
if (l != NULL && (flags & ~SYSCTL_USERFLAGS))
return (EPERM);
if ((flags & CTLFLAG_PERMANENT) &
(sysctl_root.sysctl_flags & CTLFLAG_PERMANENT))
return (EPERM);
if ((flags & (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE)) ==
(CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE))
return (EINVAL);
if ((flags & CTLFLAG_IMMEDIATE) &&
type != CTLTYPE_INT && type != CTLTYPE_QUAD && type != CTLTYPE_BOOL)
return (EINVAL);
/*
* check size, or set it if unset and we can figure it out.
* kernel created nodes are allowed to have a function instead
* of a size (or a data pointer).
*/
switch (type) {
case CTLTYPE_NODE:
/*
* only *i* can assert the size of a node
*/
if (flags & CTLFLAG_ALIAS) {
anum = nnode.sysctl_alias;
if (anum < 0)
return (EINVAL);
nnode.sysctl_alias = 0;
}
if (sz != 0 || nnode.sysctl_data != NULL)
return (EINVAL);
if (nnode.sysctl_csize != 0 ||
nnode.sysctl_clen != 0 ||
nnode.sysctl_child != 0)
return (EINVAL);
if (flags & CTLFLAG_OWNDATA)
return (EINVAL);
sz = sizeof(struct sysctlnode);
break;
case CTLTYPE_INT:
/*
* since an int is an int, if the size is not given or
* is wrong, we can "int-uit" it.
*/
if (sz != 0 && sz != sizeof(int))
return (EINVAL);
sz = sizeof(int);
break;
case CTLTYPE_STRING:
/*
* strings are a little more tricky
*/
if (sz == 0) {
if (l == NULL) {
if (nnode.sysctl_func == NULL) {
if (nnode.sysctl_data == NULL)
return (EINVAL);
else
sz = strlen(nnode.sysctl_data) +
1;
}
} else if (nnode.sysctl_data == NULL &&
flags & CTLFLAG_OWNDATA) {
return (EINVAL);
} else {
char *vp, *e;
size_t s;
/*
* we want a rough idea of what the
* size is now
*/
vp = malloc(PAGE_SIZE, M_SYSCTLDATA, M_WAITOK);
if (vp == NULL)
return (ENOMEM);
e = nnode.sysctl_data;
do {
error = copyinstr(e, vp, PAGE_SIZE, &s);
if (error) {
if (error != ENAMETOOLONG) {
free(vp, M_SYSCTLDATA);
return (error);
}
e += PAGE_SIZE;
if ((e - 32 * PAGE_SIZE) >
(char*)nnode.sysctl_data) {
free(vp, M_SYSCTLDATA);
return (ERANGE);
}
}
} while (error != 0);
sz = s + (e - (char*)nnode.sysctl_data);
free(vp, M_SYSCTLDATA);
}
}
break;
case CTLTYPE_QUAD:
if (sz != 0 && sz != sizeof(u_quad_t))
return (EINVAL);
sz = sizeof(u_quad_t);
break;
case CTLTYPE_BOOL:
/*
* since an bool is an bool, if the size is not given or
* is wrong, we can "intuit" it.
*/
if (sz != 0 && sz != sizeof(bool))
return (EINVAL);
sz = sizeof(bool);
break;
case CTLTYPE_STRUCT:
if (sz == 0) {
if (l != NULL || nnode.sysctl_func == NULL)
return (EINVAL);
if (flags & CTLFLAG_OWNDATA)
return (EINVAL);
}
break;