1/*-
2 * Copyright (c) 1998 John D. Polstra
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include <sys/param.h>
30#include <sys/mman.h>
31#include <sys/stat.h>
32
33#include <ctype.h>
34#include <dirent.h>
35#include <elf-hints.h>
36#include <err.h>
37#include <errno.h>
38#include <fcntl.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#include "ldconfig.h"
45
46#define MAXDIRS		1024		/* Maximum directories in path */
47#define MAXFILESIZE	(16*1024)	/* Maximum hints file size */
48
49static void	add_dir(const char *, const char *, int);
50static void	read_dirs_from_file(const char *, const char *);
51static void	read_elf_hints(const char *, int);
52static void	write_elf_hints(const char *);
53
54static const char	*dirs[MAXDIRS];
55static int		 ndirs;
56int			 insecure;
57
58static void
59add_dir(const char *hintsfile, const char *name, int trusted)
60{
61	struct stat 	stbuf;
62	int		i;
63
64	/* Do some security checks */
65	if (!trusted && !insecure) {
66		if (stat(name, &stbuf) == -1) {
67			warn("%s", name);
68			return;
69		}
70		if (stbuf.st_uid != 0) {
71			warnx("%s: ignoring directory not owned by root", name);
72			return;
73		}
74		if ((stbuf.st_mode & S_IWOTH) != 0) {
75			warnx("%s: ignoring world-writable directory", name);
76			return;
77		}
78		if ((stbuf.st_mode & S_IWGRP) != 0) {
79			warnx("%s: ignoring group-writable directory", name);
80			return;
81		}
82	}
83
84	for (i = 0;  i < ndirs;  i++)
85		if (strcmp(dirs[i], name) == 0)
86			return;
87	if (ndirs >= MAXDIRS)
88		errx(1, "\"%s\": Too many directories in path", hintsfile);
89	dirs[ndirs++] = name;
90}
91
92void
93list_elf_hints(const char *hintsfile)
94{
95	int	i;
96	int	nlibs;
97
98	read_elf_hints(hintsfile, 1);
99	printf("%s:\n", hintsfile);
100	printf("\tsearch directories:");
101	for (i = 0;  i < ndirs;  i++)
102		printf("%c%s", i == 0 ? ' ' : ':', dirs[i]);
103	printf("\n");
104
105	nlibs = 0;
106	for (i = 0;  i < ndirs;  i++) {
107		DIR		*dirp;
108		struct dirent	*dp;
109
110		if ((dirp = opendir(dirs[i])) == NULL)
111			continue;
112		while ((dp = readdir(dirp)) != NULL) {
113			int		 len;
114			int		 namelen;
115			const char	*name;
116			const char	*vers;
117
118			/* Name can't be shorter than "libx.so.0" */
119			if ((len = strlen(dp->d_name)) < 9 ||
120			    strncmp(dp->d_name, "lib", 3) != 0)
121				continue;
122			name = dp->d_name + 3;
123			vers = dp->d_name + len;
124			while (vers > dp->d_name && isdigit(*(vers-1)))
125				vers--;
126			if (vers == dp->d_name + len)
127				continue;
128			if (vers < dp->d_name + 4 ||
129			    strncmp(vers - 4, ".so.", 4) != 0)
130				continue;
131
132			/* We have a valid shared library name. */
133			namelen = (vers - 4) - name;
134			printf("\t%d:-l%.*s.%s => %s/%s\n", nlibs,
135			    namelen, name, vers, dirs[i], dp->d_name);
136			nlibs++;
137		}
138		closedir(dirp);
139	}
140}
141
142static void
143read_dirs_from_file(const char *hintsfile, const char *listfile)
144{
145	FILE	*fp;
146	char	 buf[MAXPATHLEN];
147	int	 linenum;
148
149	if ((fp = fopen(listfile, "r")) == NULL)
150		err(1, "%s", listfile);
151
152	linenum = 0;
153	while (fgets(buf, sizeof buf, fp) != NULL) {
154		char	*cp, *sp;
155
156		linenum++;
157		cp = buf;
158		/* Skip leading white space. */
159		while (isspace(*cp))
160			cp++;
161		if (*cp == '#' || *cp == '\0')
162			continue;
163		sp = cp;
164		/* Advance over the directory name. */
165		while (!isspace(*cp) && *cp != '\0')
166			cp++;
167		/* Terminate the string and skip trailing white space. */
168		if (*cp != '\0') {
169			*cp++ = '\0';
170			while (isspace(*cp))
171				cp++;
172		}
173		/* Now we had better be at the end of the line. */
174		if (*cp != '\0')
175			warnx("%s:%d: trailing characters ignored",
176			    listfile, linenum);
177
178		if ((sp = strdup(sp)) == NULL)
179			errx(1, "Out of memory");
180		add_dir(hintsfile, sp, 0);
181	}
182
183	fclose(fp);
184}
185
186static void
187read_elf_hints(const char *hintsfile, int must_exist)
188{
189	int	 		 fd;
190	struct stat		 s;
191	void			*mapbase;
192	struct elfhints_hdr	*hdr;
193	char			*strtab;
194	char			*dirlist;
195	char			*p;
196
197	if ((fd = open(hintsfile, O_RDONLY)) == -1) {
198		if (errno == ENOENT && !must_exist)
199			return;
200		err(1, "Cannot open \"%s\"", hintsfile);
201	}
202	if (fstat(fd, &s) == -1)
203		err(1, "Cannot stat \"%s\"", hintsfile);
204	if (s.st_size > MAXFILESIZE)
205		errx(1, "\"%s\" is unreasonably large", hintsfile);
206	/*
207	 * We use a read-write, private mapping so that we can null-terminate
208	 * some strings in it without affecting the underlying file.
209	 */
210	mapbase = mmap(NULL, s.st_size, PROT_READ|PROT_WRITE,
211	    MAP_PRIVATE, fd, 0);
212	if (mapbase == MAP_FAILED)
213		err(1, "Cannot mmap \"%s\"", hintsfile);
214	close(fd);
215
216	hdr = (struct elfhints_hdr *)mapbase;
217	if (hdr->magic != ELFHINTS_MAGIC)
218		errx(1, "\"%s\": invalid file format", hintsfile);
219	if (hdr->version != 1)
220		errx(1, "\"%s\": unrecognized file version (%d)", hintsfile,
221		    hdr->version);
222
223	strtab = (char *)mapbase + hdr->strtab;
224	dirlist = strtab + hdr->dirlist;
225
226	if (*dirlist != '\0')
227		while ((p = strsep(&dirlist, ":")) != NULL)
228			add_dir(hintsfile, p, 1);
229}
230
231void
232update_elf_hints(const char *hintsfile, int argc, char **argv, int merge)
233{
234	int	i;
235
236	if (merge)
237		read_elf_hints(hintsfile, 0);
238	for (i = 0;  i < argc;  i++) {
239		struct stat	s;
240
241		if (stat(argv[i], &s) == -1)
242			warn("warning: %s", argv[i]);
243		else if (S_ISREG(s.st_mode))
244			read_dirs_from_file(hintsfile, argv[i]);
245		else
246			add_dir(hintsfile, argv[i], 0);
247	}
248	write_elf_hints(hintsfile);
249}
250
251static void
252write_elf_hints(const char *hintsfile)
253{
254	struct elfhints_hdr	 hdr;
255	char			*tempname;
256	int			 fd;
257	FILE			*fp;
258	int			 i;
259
260	if (asprintf(&tempname, "%s.XXXXXX", hintsfile) == -1)
261		errx(1, "Out of memory");
262	if ((fd = mkstemp(tempname)) ==  -1)
263		err(1, "mkstemp(%s)", tempname);
264	if (fchmod(fd, 0444) == -1)
265		err(1, "fchmod(%s)", tempname);
266	if ((fp = fdopen(fd, "wb")) == NULL)
267		err(1, "fdopen(%s)", tempname);
268
269	hdr.magic = ELFHINTS_MAGIC;
270	hdr.version = 1;
271	hdr.strtab = sizeof hdr;
272	hdr.strsize = 0;
273	hdr.dirlist = 0;
274	memset(hdr.spare, 0, sizeof hdr.spare);
275
276	/* Count up the size of the string table. */
277	if (ndirs > 0) {
278		hdr.strsize += strlen(dirs[0]);
279		for (i = 1;  i < ndirs;  i++)
280			hdr.strsize += 1 + strlen(dirs[i]);
281	}
282	hdr.dirlistlen = hdr.strsize;
283	hdr.strsize++;	/* For the null terminator */
284
285	/* Write the header. */
286	if (fwrite(&hdr, 1, sizeof hdr, fp) != sizeof hdr)
287		err(1, "%s: write error", tempname);
288	/* Write the strings. */
289	if (ndirs > 0) {
290		if (fputs(dirs[0], fp) == EOF)
291			err(1, "%s: write error", tempname);
292		for (i = 1;  i < ndirs;  i++)
293			if (fprintf(fp, ":%s", dirs[i]) < 0)
294				err(1, "%s: write error", tempname);
295	}
296	if (putc('\0', fp) == EOF || fclose(fp) == EOF)
297		err(1, "%s: write error", tempname);
298
299	if (rename(tempname, hintsfile) == -1)
300		err(1, "rename %s to %s", tempname, hintsfile);
301	free(tempname);
302}
303