Return to sysctlgetmibinfo.c CVS log

Up to [cvs.NetBSD.org] / src / lib / libc / gen

Enhance the support of LLVM sanitizers

Define _REENTRANT for MKSANITIZER build. This is needed for at least stdio
code. This caused new build issued with duplicated symbols in few places
and rump kernel code picking different code paths borrowed from libc.
Handle all this in one go.

Add bsd.sanitizer.mk to share common code used by programs and libraries.

Switch from realall to beforeinstall target in .syms files. This is more
reliable in MKSANITIZER.

/*	$NetBSD: sysctlgetmibinfo.c,v 1.14 2019/08/27 22:48:53 kamil 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 1.14 2019/08/27 22:48:53 kamil Exp $");
#endif /* LIBC_SCCS and not lint */

#ifndef RUMP_ACTION
#include "namespace.h"
#ifdef _REENTRANT
#include "reentrant.h"
#endif /* _REENTRANT */
#endif /* RUMP_ACTION */
#include <sys/param.h>
#include <sys/sysctl.h>

#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>

#ifdef RUMP_ACTION
#include <rump/rump_syscalls.h>
#define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f)
#else
#ifdef __weak_alias
__weak_alias(__learn_tree,___learn_tree)
__weak_alias(sysctlgetmibinfo,_sysctlgetmibinfo)
#endif
#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,
	.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;
	size_t nlen, olen, ni, oi;
	uint32_t 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, 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
	 */
	_DIAGASSERT(__type_fit(uint32_t, nlen));
	sysctl_mibroot.sysctl_csize =
	    sysctl_mibroot.sysctl_clen = (uint32_t)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;
	uint32_t rc;
	size_t sz;
	int serrno;

	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) {
		serrno = errno;
		free(pnode->sysctl_child);
		errno = serrno;
		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) {
			serrno = errno;
			free(pnode->sysctl_child);
			errno = serrno;
			pnode->sysctl_child = NULL;
			return (rc);
		}
	}

	/*
	 * how many did we get?
	 */
	sz /= sizeof(struct sysctlnode);
	pnode->sysctl_csize = pnode->sysctl_clen = (uint32_t)sz;
	if (pnode->sysctl_clen != 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.
 */
#if defined(_REENTRANT) && !defined(RUMP_ACTION)
static mutex_t sysctl_mutex = MUTEX_INITIALIZER;
static int sysctlgetmibinfo_unlocked(const char *, int *, u_int *, char *,
				     size_t *, struct sysctlnode **, int);
#endif /* __REENTRANT && !RUMP_ACTION */

int
sysctlgetmibinfo(const char *gname, int *iname, u_int *namelenp,
		 char *cname, size_t *csz, struct sysctlnode **rnode, int v)
#if defined(_REENTRANT) && !defined(RUMP_ACTION)
{
	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 && !RUMP_ACTION */
{
	struct sysctlnode *pnode, *node;
	int name[CTL_MAXNAME], n, haven;
	u_int ni, 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) {
				errno = EINVAL;
				return -1;
			}

			pnode = &sysctl_mibroot;
		}
		else {
			/* this is just someone being silly */
			if (SYSCTL_VERS((*rnode)->sysctl_flags)
			    != (uint32_t)v) {
				errno = EINVAL;
				return -1;
			}

			/* XXX later deal with other people's trees */
			if (SYSCTL_VERS((*rnode)->sysctl_flags) !=
			    SYSCTL_VERSION) {
				errno = EINVAL;
				return -1;
			}

			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 > (intptr_t)(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);
}