NetBSD/libexec/ld.elf_so/paths.c

/*	$NetBSD: paths.c,v 1.6 1999/08/20 21:10:27 christos Exp $	 */

/*
 * Copyright 1996 Matt Thomas <matt@3am-software.com>
 * All rights reserved.
 *
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <dirent.h>

#include "debug.h"
#include "rtld.h"

static Search_Path *_rtld_find_path __P((Search_Path *, const char *, size_t));
static Search_Path **_rtld_append_path __P((Search_Path **, Search_Path **,
    const char *, const char *, bool));

static Search_Path *
_rtld_find_path(path, pathstr, pathlen)
	Search_Path *path;
	const char *pathstr;
	size_t pathlen;
{
	for (; path != NULL; path = path->sp_next) {
		if (pathlen == path->sp_pathlen &&
		    memcmp(path->sp_path, pathstr, pathlen) == 0)
			return path;
	}
	return NULL;
}

static Search_Path **
_rtld_append_path(head_p, path_p, bp, ep, dodebug)
	Search_Path **head_p, **path_p;
	const char *bp;
	const char *ep;
	bool dodebug;
{
	char *cp;
	Search_Path *path;

	if (bp == NULL || bp == ep || *bp == '\0')
		return path_p;

	if (_rtld_find_path(*head_p, bp, ep - bp) != NULL)
		return path_p;

	path = CNEW(Search_Path);
	path->sp_pathlen = ep - bp;
	cp = xmalloc(path->sp_pathlen + 1);
	strncpy(cp, bp, path->sp_pathlen);
	cp[path->sp_pathlen] = '\0';
	path->sp_path = cp;
	path->sp_next = (*path_p);
	(*path_p) = path;
	path_p = &path->sp_next;

	if (dodebug)
		dbg((" added path \"%s\"", path->sp_path));
	return path_p;
}

void
_rtld_add_paths(path_p, pathstr, dodebug)
	Search_Path **path_p;
	const char *pathstr;
	bool dodebug;
{
	Search_Path **head_p = path_p;

	if (pathstr == NULL)
		return;

	if (pathstr[0] == ':') {
		/*
		 * Leading colon means append to current path
		 */
		while ((*path_p) != NULL)
			path_p = &(*path_p)->sp_next;
		pathstr++;
	}

	for (;;) {
		const char *bp = pathstr;
		const char *ep = strchr(bp, ':');
		if (ep == NULL)
			ep = &pathstr[strlen(pathstr)];

		path_p = _rtld_append_path(head_p, path_p, bp, ep, dodebug);

		if (ep[0] == '\0')
			break;
		pathstr = ep + 1;
	}
}

void
_rtld_process_hints(path_p, fname, dodebug)
	Search_Path **path_p;
	const char *fname;
	bool dodebug;
{
	int fd;
	char *p, *buf, *b, *ebuf;
	struct stat st;
	size_t sz;
	Search_Path **head_p = path_p;

	if ((fd = open(fname, O_RDONLY)) == -1) {
		/* Don't complain */
		return;
	}

	if (fstat(fd, &st) == -1) {
		/* Complain */
		xwarn("fstat: %s", fname);
		return;
	}

	sz = (size_t) st.st_size;

	buf = mmap(0, sz, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FILE, fd, 0);
	if (buf == MAP_FAILED) {
		xwarn("fstat: %s", fname);
		(void)close(fd);
		return;
	}
	(void)close(fd);

	while ((*path_p) != NULL)
		path_p = &(*path_p)->sp_next;

	for (b = NULL, p = buf, ebuf = buf + sz; p < ebuf; p++) {

		if ((p == buf || p[-1] == '\0') && b == NULL)
			b = p;

		switch (*p) {
		case ' ': case '\t':
			if (b == p)
				b++;
			break;

		case '\n':
			*p = '\0';
			path_p = _rtld_append_path(head_p, path_p, b, p,
			    dodebug);
			b = NULL;
			break;

		case '#':
			if (b != p) {
				char *sp;
				for  (sp = p - 1; *sp == ' ' ||
				    *sp == '\t'; --sp)
					continue;
				*++sp = '\0';
				path_p = _rtld_append_path(head_p, path_p, b,
				    sp, dodebug);
				*sp = ' ';
			}
			b = NULL;
			break;

		default:
			break;
		}
	}

	path_p = _rtld_append_path(head_p, path_p, b, ebuf, dodebug);

	(void)munmap(buf, sz);
}