NetBSD/lib/libc/gen/sysctlgetmibinfo.c

601 lines
14 KiB
C

/* $NetBSD: sysctlgetmibinfo.c,v 1.6 2008/04/29 06:53:01 martin Exp $ */
/*-
* Copyright (c) 2003,2004 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: sysctlgetmibinfo.c,v 1.6 2008/04/29 06:53:01 martin Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#ifdef _REENTRANT
#include "reentrant.h"
#endif /* _REENTRANT */
#include <sys/param.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#ifdef __weak_alias
__weak_alias(__learn_tree,___learn_tree)
__weak_alias(sysctlgetmibinfo,_sysctlgetmibinfo)
#endif
/*
* the place where we attach stuff we learn on the fly, not
* necessarily used.
*/
static struct sysctlnode sysctl_mibroot = {
#if defined(lint)
/*
* lint doesn't like my initializers
*/
0
#else /* !lint */
.sysctl_flags = SYSCTL_VERSION|CTLFLAG_ROOT|CTLTYPE_NODE,
sysc_init_field(_sysctl_size, sizeof(struct sysctlnode)),
.sysctl_name = "(root)",
#endif /* !lint */
};
/*
* routines to handle learning and cleanup
*/
static int compar(const void *, const void *);
static void free_children(struct sysctlnode *);
static void relearnhead(void);
/*
* specifically not static since sysctl(8) "borrows" it.
*/
int __learn_tree(int *, u_int, struct sysctlnode *);
/*
* for ordering nodes -- a query may or may not be given them in
* numeric order
*/
static int
compar(const void *a, const void *b)
{
return (((const struct sysctlnode *)a)->sysctl_num -
((const struct sysctlnode *)b)->sysctl_num);
}
/*
* recursively nukes a branch or an entire tree from the given node
*/
static void
free_children(struct sysctlnode *rnode)
{
struct sysctlnode *node;
if (rnode == NULL ||
SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE ||
rnode->sysctl_child == NULL)
return;
for (node = rnode->sysctl_child;
node < &rnode->sysctl_child[rnode->sysctl_clen];
node++) {
free_children(node);
}
free(rnode->sysctl_child);
rnode->sysctl_child = NULL;
}
/*
* verifies that the head of the tree in the kernel is the same as the
* head of the tree we already got, integrating new stuff and removing
* old stuff, if it's not.
*/
static void
relearnhead(void)
{
struct sysctlnode *h, *i, *o, qnode;
size_t si, so;
int rc, name, nlen, olen, ni, oi, t;
/*
* if there's nothing there, there's no need to expend any
* effort
*/
if (sysctl_mibroot.sysctl_child == NULL)
return;
/*
* attempt to pull out the head of the tree, starting with the
* size we have now, and looping if we need more (or less)
* space
*/
si = 0;
so = sysctl_mibroot.sysctl_clen * sizeof(struct sysctlnode);
name = CTL_QUERY;
memset(&qnode, 0, sizeof(qnode));
qnode.sysctl_flags = SYSCTL_VERSION;
do {
si = so;
h = malloc(si);
rc = sysctl(&name, 1, h, &so, &qnode, sizeof(qnode));
if (rc == -1 && errno != ENOMEM)
return;
if (si < so)
free(h);
} while (si < so);
/*
* order the new copy of the head
*/
nlen = so / sizeof(struct sysctlnode);
qsort(h, (size_t)nlen, sizeof(struct sysctlnode), compar);
/*
* verify that everything is the same. if it is, we don't
* need to do any more work here.
*/
olen = sysctl_mibroot.sysctl_clen;
rc = (nlen == olen) ? 0 : 1;
o = sysctl_mibroot.sysctl_child;
for (ni = 0; rc == 0 && ni < nlen; ni++) {
if (h[ni].sysctl_num != o[ni].sysctl_num ||
h[ni].sysctl_ver != o[ni].sysctl_ver)
rc = 1;
}
if (rc == 0) {
free(h);
return;
}
/*
* something changed. h will become the new head, and we need
* pull over any subtrees we already have if they're the same
* version.
*/
i = h;
ni = oi = 0;
while (ni < nlen && oi < olen) {
/*
* something was inserted or deleted
*/
if (SYSCTL_TYPE(i[ni].sysctl_flags) == CTLTYPE_NODE)
i[ni].sysctl_child = NULL;
if (i[ni].sysctl_num != o[oi].sysctl_num) {
if (i[ni].sysctl_num < o[oi].sysctl_num) {
ni++;
}
else {
free_children(&o[oi]);
oi++;
}
continue;
}
/*
* same number, but different version, so throw away
* any accumulated children
*/
if (i[ni].sysctl_ver != o[oi].sysctl_ver)
free_children(&o[oi]);
/*
* this node is the same, but we only need to
* move subtrees.
*/
else if (SYSCTL_TYPE(i[ni].sysctl_flags) == CTLTYPE_NODE) {
/*
* move subtree to new parent
*/
i[ni].sysctl_clen = o[oi].sysctl_clen;
i[ni].sysctl_csize = o[oi].sysctl_csize;
i[ni].sysctl_child = o[oi].sysctl_child;
/*
* reparent inherited subtree
*/
for (t = 0;
i[ni].sysctl_child != NULL &&
t < i[ni].sysctl_clen;
t++)
i[ni].sysctl_child[t].sysctl_parent = &i[ni];
}
ni++;
oi++;
}
/*
* left over new nodes need to have empty subtrees cleared
*/
while (ni < nlen) {
if (SYSCTL_TYPE(i[ni].sysctl_flags) == CTLTYPE_NODE)
i[ni].sysctl_child = NULL;
ni++;
}
/*
* left over old nodes need to be cleaned out
*/
while (oi < olen) {
free_children(&o[oi]);
oi++;
}
/*
* pop new head in
*/
sysctl_mibroot.sysctl_clen = nlen;
sysctl_mibroot.sysctl_csize = nlen;
sysctl_mibroot.sysctl_child = h;
free(o);
}
/*
* sucks in the children at a given level and attaches it to the tree.
*/
int
__learn_tree(int *name, u_int namelen, struct sysctlnode *pnode)
{
struct sysctlnode qnode;
int rc;
size_t sz;
if (pnode == NULL)
pnode = &sysctl_mibroot;
if (SYSCTL_TYPE(pnode->sysctl_flags) != CTLTYPE_NODE) {
errno = EINVAL;
return (-1);
}
if (pnode->sysctl_child != NULL)
return (0);
if (pnode->sysctl_clen == 0)
sz = SYSCTL_DEFSIZE * sizeof(struct sysctlnode);
else
sz = pnode->sysctl_clen * sizeof(struct sysctlnode);
pnode->sysctl_child = malloc(sz);
if (pnode->sysctl_child == NULL)
return (-1);
name[namelen] = CTL_QUERY;
pnode->sysctl_clen = 0;
pnode->sysctl_csize = 0;
memset(&qnode, 0, sizeof(qnode));
qnode.sysctl_flags = SYSCTL_VERSION;
rc = sysctl(name, namelen + 1, pnode->sysctl_child, &sz,
&qnode, sizeof(qnode));
if (sz == 0) {
free(pnode->sysctl_child);
pnode->sysctl_child = NULL;
return (rc);
}
if (rc) {
free(pnode->sysctl_child);
pnode->sysctl_child = NULL;
if ((sz % sizeof(struct sysctlnode)) != 0)
errno = EINVAL;
if (errno != ENOMEM)
return (rc);
}
if (pnode->sysctl_child == NULL) {
pnode->sysctl_child = malloc(sz);
if (pnode->sysctl_child == NULL)
return (-1);
rc = sysctl(name, namelen + 1, pnode->sysctl_child, &sz,
&qnode, sizeof(qnode));
if (rc) {
free(pnode->sysctl_child);
pnode->sysctl_child = NULL;
return (rc);
}
}
/*
* how many did we get?
*/
pnode->sysctl_clen = sz / sizeof(struct sysctlnode);
pnode->sysctl_csize = sz / sizeof(struct sysctlnode);
if (pnode->sysctl_clen * sizeof(struct sysctlnode) != sz) {
free(pnode->sysctl_child);
pnode->sysctl_child = NULL;
errno = EINVAL;
return (-1);
}
/*
* you know, the kernel doesn't really keep them in any
* particular order...just like entries in a directory
*/
qsort(pnode->sysctl_child, pnode->sysctl_clen,
sizeof(struct sysctlnode), compar);
/*
* rearrange parent<->child linkage
*/
for (rc = 0; rc < pnode->sysctl_clen; rc++) {
pnode->sysctl_child[rc].sysctl_parent = pnode;
if (SYSCTL_TYPE(pnode->sysctl_child[rc].sysctl_flags) ==
CTLTYPE_NODE) {
/*
* these nodes may have children, but we
* haven't discovered that yet.
*/
pnode->sysctl_child[rc].sysctl_child = NULL;
}
pnode->sysctl_child[rc].sysctl_desc = NULL;
}
return (0);
}
/*
* that's "given name" as a string, the integer form of the name fit
* to be passed to sysctl(), "canonicalized name" (optional), and a
* pointer to the length of the integer form. oh, and then a pointer
* to the node, in case you (the caller) care. you can leave them all
* NULL except for gname, though that might be rather pointless,
* unless all you wanna do is verify that a given name is acceptable.
*
* returns either 0 (everything was fine) or -1 and sets errno
* accordingly. if errno is set to EAGAIN, we detected a change to
* the mib while parsing, and you should try again. in the case of an
* invalid node name, cname will be set to contain the offending name.
*/
#ifdef _REENTRANT
static mutex_t sysctl_mutex = MUTEX_INITIALIZER;
static int sysctlgetmibinfo_unlocked(const char *, int *, u_int *, char *,
size_t *, struct sysctlnode **, int);
#endif /* __REENTRANT */
int
sysctlgetmibinfo(const char *gname, int *iname, u_int *namelenp,
char *cname, size_t *csz, struct sysctlnode **rnode, int v)
#ifdef _REENTRANT
{
int rc;
mutex_lock(&sysctl_mutex);
rc = sysctlgetmibinfo_unlocked(gname, iname, namelenp, cname, csz,
rnode, v);
mutex_unlock(&sysctl_mutex);
return (rc);
}
static int
sysctlgetmibinfo_unlocked(const char *gname, int *iname, u_int *namelenp,
char *cname, size_t *csz, struct sysctlnode **rnode,
int v)
#endif /* _REENTRANT */
{
struct sysctlnode *pnode, *node;
int name[CTL_MAXNAME], ni, n, haven;
u_int nl;
intmax_t q;
char sep[2], token[SYSCTL_NAMELEN],
pname[SYSCTL_NAMELEN * CTL_MAXNAME + CTL_MAXNAME];
const char *piece, *dot;
char *t;
size_t l;
if (rnode != NULL) {
if (*rnode == NULL) {
/* XXX later deal with dealing back a sub version */
if (v != SYSCTL_VERSION)
return (EINVAL);
pnode = &sysctl_mibroot;
}
else {
/* this is just someone being silly */
if (SYSCTL_VERS((*rnode)->sysctl_flags) != v)
return (EINVAL);
/* XXX later deal with other people's trees */
if (SYSCTL_VERS((*rnode)->sysctl_flags) !=
SYSCTL_VERSION)
return (EINVAL);
pnode = *rnode;
}
}
else
pnode = &sysctl_mibroot;
if (pnode == &sysctl_mibroot)
relearnhead();
nl = ni = 0;
token[0] = '\0';
pname[0] = '\0';
node = NULL;
/*
* default to using '.' as the separator, but allow '/' as
* well, and then allow a leading separator
*/
if ((dot = strpbrk(gname, "./")) == NULL)
sep[0] = '.';
else
sep[0] = dot[0];
sep[1] = '\0';
if (gname[0] == sep[0]) {
strlcat(pname, sep, sizeof(pname));
gname++;
}
#define COPY_OUT_DATA(t, c, cs, nlp, l) do { \
if ((c) != NULL && (cs) != NULL) \
*(cs) = strlcpy((c), (t), *(cs)); \
else if ((cs) != NULL) \
*(cs) = strlen(t) + 1; \
if ((nlp) != NULL) \
*(nlp) = (l); \
} while (/*CONSTCOND*/0)
piece = gname;
while (piece != NULL && *piece != '\0') {
/*
* what was i looking for?
*/
dot = strchr(piece, sep[0]);
if (dot == NULL) {
l = strlcpy(token, piece, sizeof(token));
if (l > sizeof(token)) {
COPY_OUT_DATA(piece, cname, csz, namelenp, nl);
errno = ENAMETOOLONG;
return (-1);
}
}
else if (dot - piece > sizeof(token) - 1) {
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
errno = ENAMETOOLONG;
return (-1);
}
else {
strncpy(token, piece, (size_t)(dot - piece));
token[dot - piece] = '\0';
}
/*
* i wonder if this "token" is an integer?
*/
errno = 0;
q = strtoimax(token, &t, 0);
n = (int)q;
if (errno != 0 || *t != '\0')
haven = 0;
else if (q < INT_MIN || q > UINT_MAX)
haven = 0;
else
haven = 1;
/*
* make sure i have something to look at
*/
if (SYSCTL_TYPE(pnode->sysctl_flags) != CTLTYPE_NODE) {
if (haven && nl > 0) {
strlcat(pname, sep, sizeof(pname));
goto just_numbers;
}
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
errno = ENOTDIR;
return (-1);
}
if (pnode->sysctl_child == NULL) {
if (__learn_tree(name, nl, pnode) == -1) {
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
return (-1);
}
}
node = pnode->sysctl_child;
if (node == NULL) {
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
errno = ENOENT;
return (-1);
}
/*
* now...is it there?
*/
for (ni = 0; ni < pnode->sysctl_clen; ni++)
if ((haven && ((n == node[ni].sysctl_num) ||
(node[ni].sysctl_flags & CTLFLAG_ANYNUMBER))) ||
strcmp(token, node[ni].sysctl_name) == 0)
break;
if (ni >= pnode->sysctl_clen) {
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
errno = ENOENT;
return (-1);
}
/*
* ah...it is.
*/
pnode = &node[ni];
if (nl > 0)
strlcat(pname, sep, sizeof(pname));
if (haven && n != pnode->sysctl_num) {
just_numbers:
strlcat(pname, token, sizeof(pname));
name[nl] = n;
}
else {
strlcat(pname, pnode->sysctl_name, sizeof(pname));
name[nl] = pnode->sysctl_num;
}
piece = (dot != NULL) ? dot + 1 : NULL;
nl++;
if (nl == CTL_MAXNAME) {
COPY_OUT_DATA(token, cname, csz, namelenp, nl);
errno = ERANGE;
return (-1);
}
}
if (nl == 0) {
if (namelenp != NULL)
*namelenp = 0;
errno = EINVAL;
return (-1);
}
COPY_OUT_DATA(pname, cname, csz, namelenp, nl);
if (iname != NULL && namelenp != NULL)
memcpy(iname, &name[0], MIN(nl, *namelenp) * sizeof(int));
if (namelenp != NULL)
*namelenp = nl;
if (rnode != NULL) {
if (*rnode != NULL)
/*
* they gave us a private tree to work in, so
* we give back a pointer into that private
* tree
*/
*rnode = pnode;
else {
/*
* they gave us a place to put the node data,
* so give them a copy
*/
*rnode = malloc(sizeof(struct sysctlnode));
if (*rnode != NULL) {
**rnode = *pnode;
(*rnode)->sysctl_child = NULL;
(*rnode)->sysctl_parent = NULL;
}
}
}
return (0);
}