1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998 John D. Polstra
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/param.h>
32 #include <sys/mman.h>
33 #include <sys/stat.h>
34
35 #include <ctype.h>
36 #include <dirent.h>
37 #include <elf-hints.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45
46 #include "ldconfig.h"
47
48 #define MAXDIRS 1024 /* Maximum directories in path */
49 #define MAXFILESIZE (16*1024) /* Maximum hints file size */
50
51 static void add_dir(const char *, const char *, bool);
52 static void read_dirs_from_file(const char *, const char *);
53 static void read_elf_hints(const char *, bool);
54 static void write_elf_hints(const char *);
55
56 static const char *dirs[MAXDIRS];
57 static int ndirs;
58 bool insecure;
59
60 static void
add_dir(const char * hintsfile,const char * name,bool trusted)61 add_dir(const char *hintsfile, const char *name, bool trusted)
62 {
63 struct stat stbuf;
64 int i;
65
66 /* Do some security checks */
67 if (!trusted && !insecure) {
68 if (stat(name, &stbuf) == -1) {
69 warn("%s", name);
70 return;
71 }
72 if (stbuf.st_uid != 0) {
73 warnx("%s: ignoring directory not owned by root", name);
74 return;
75 }
76 if ((stbuf.st_mode & S_IWOTH) != 0) {
77 warnx("%s: ignoring world-writable directory", name);
78 return;
79 }
80 if ((stbuf.st_mode & S_IWGRP) != 0) {
81 warnx("%s: ignoring group-writable directory", name);
82 return;
83 }
84 }
85
86 for (i = 0; i < ndirs; i++)
87 if (strcmp(dirs[i], name) == 0)
88 return;
89 if (ndirs >= MAXDIRS)
90 errx(1, "\"%s\": Too many directories in path", hintsfile);
91 dirs[ndirs++] = name;
92 }
93
94 void
list_elf_hints(const char * hintsfile)95 list_elf_hints(const char *hintsfile)
96 {
97 int i;
98 int nlibs;
99
100 read_elf_hints(hintsfile, 1);
101 printf("%s:\n", hintsfile);
102 printf("\tsearch directories:");
103 for (i = 0; i < ndirs; i++)
104 printf("%c%s", i == 0 ? ' ' : ':', dirs[i]);
105 printf("\n");
106
107 nlibs = 0;
108 for (i = 0; i < ndirs; i++) {
109 DIR *dirp;
110 struct dirent *dp;
111
112 if ((dirp = opendir(dirs[i])) == NULL)
113 continue;
114 while ((dp = readdir(dirp)) != NULL) {
115 int len;
116 int namelen;
117 const char *name;
118 const char *vers;
119
120 /* Name can't be shorter than "libx.so.0" */
121 if ((len = strlen(dp->d_name)) < 9 ||
122 strncmp(dp->d_name, "lib", 3) != 0)
123 continue;
124 name = dp->d_name + 3;
125 vers = dp->d_name + len;
126 while (vers > dp->d_name && isdigit(*(vers-1)))
127 vers--;
128 if (vers == dp->d_name + len)
129 continue;
130 if (vers < dp->d_name + 4 ||
131 strncmp(vers - 4, ".so.", 4) != 0)
132 continue;
133
134 /* We have a valid shared library name. */
135 namelen = (vers - 4) - name;
136 printf("\t%d:-l%.*s.%s => %s/%s\n", nlibs,
137 namelen, name, vers, dirs[i], dp->d_name);
138 nlibs++;
139 }
140 closedir(dirp);
141 }
142 }
143
144 static void
read_dirs_from_file(const char * hintsfile,const char * listfile)145 read_dirs_from_file(const char *hintsfile, const char *listfile)
146 {
147 FILE *fp;
148 char buf[MAXPATHLEN];
149 int linenum;
150
151 if ((fp = fopen(listfile, "r")) == NULL)
152 err(1, "%s", listfile);
153
154 linenum = 0;
155 while (fgets(buf, sizeof buf, fp) != NULL) {
156 char *cp, *sp;
157
158 linenum++;
159 cp = buf;
160 /* Skip leading white space. */
161 while (isspace(*cp))
162 cp++;
163 if (*cp == '#' || *cp == '\0')
164 continue;
165 sp = cp;
166 /* Advance over the directory name. */
167 while (!isspace(*cp) && *cp != '\0')
168 cp++;
169 /* Terminate the string and skip trailing white space. */
170 if (*cp != '\0') {
171 *cp++ = '\0';
172 while (isspace(*cp))
173 cp++;
174 }
175 /* Now we had better be at the end of the line. */
176 if (*cp != '\0')
177 warnx("%s:%d: trailing characters ignored",
178 listfile, linenum);
179
180 if ((sp = strdup(sp)) == NULL)
181 errx(1, "Out of memory");
182 add_dir(hintsfile, sp, 0);
183 }
184
185 fclose(fp);
186 }
187
188 static void
read_elf_hints(const char * hintsfile,bool must_exist)189 read_elf_hints(const char *hintsfile, bool must_exist)
190 {
191 int fd;
192 struct stat s;
193 void *mapbase;
194 struct elfhints_hdr *hdr;
195 char *strtab;
196 char *dirlist;
197 char *p;
198
199 if ((fd = open(hintsfile, O_RDONLY)) == -1) {
200 if (errno == ENOENT && !must_exist)
201 return;
202 err(1, "Cannot open \"%s\"", hintsfile);
203 }
204 if (fstat(fd, &s) == -1)
205 err(1, "Cannot stat \"%s\"", hintsfile);
206 if (s.st_size > MAXFILESIZE)
207 errx(1, "\"%s\" is unreasonably large", hintsfile);
208 /*
209 * We use a read-write, private mapping so that we can null-terminate
210 * some strings in it without affecting the underlying file.
211 */
212 mapbase = mmap(NULL, s.st_size, PROT_READ|PROT_WRITE,
213 MAP_PRIVATE, fd, 0);
214 if (mapbase == MAP_FAILED)
215 err(1, "Cannot mmap \"%s\"", hintsfile);
216 close(fd);
217
218 hdr = (struct elfhints_hdr *)mapbase;
219 if (hdr->magic != ELFHINTS_MAGIC)
220 errx(1, "\"%s\": invalid file format", hintsfile);
221 if (hdr->version != 1)
222 errx(1, "\"%s\": unrecognized file version (%d)", hintsfile,
223 hdr->version);
224
225 strtab = (char *)mapbase + hdr->strtab;
226 dirlist = strtab + hdr->dirlist;
227
228 if (*dirlist != '\0')
229 while ((p = strsep(&dirlist, ":")) != NULL)
230 add_dir(hintsfile, p, 1);
231 }
232
233 void
update_elf_hints(const char * hintsfile,int argc,char ** argv,bool merge)234 update_elf_hints(const char *hintsfile, int argc, char **argv, bool merge)
235 {
236 struct stat s;
237 int i;
238
239 if (merge)
240 read_elf_hints(hintsfile, false);
241 for (i = 0; i < argc; i++) {
242 if (stat(argv[i], &s) == -1)
243 warn("warning: %s", argv[i]);
244 else if (S_ISREG(s.st_mode))
245 read_dirs_from_file(hintsfile, argv[i]);
246 else
247 add_dir(hintsfile, argv[i], 0);
248 }
249 write_elf_hints(hintsfile);
250 }
251
252 static void
write_elf_hints(const char * hintsfile)253 write_elf_hints(const char *hintsfile)
254 {
255 struct elfhints_hdr hdr;
256 char *tempname;
257 int fd;
258 FILE *fp;
259 int i;
260
261 if (asprintf(&tempname, "%s.XXXXXX", hintsfile) == -1)
262 errx(1, "Out of memory");
263 if ((fd = mkstemp(tempname)) == -1)
264 err(1, "mkstemp(%s)", tempname);
265 if (fchmod(fd, 0444) == -1)
266 err(1, "fchmod(%s)", tempname);
267 if ((fp = fdopen(fd, "wb")) == NULL)
268 err(1, "fdopen(%s)", tempname);
269
270 hdr.magic = ELFHINTS_MAGIC;
271 hdr.version = 1;
272 hdr.strtab = sizeof hdr;
273 hdr.strsize = 0;
274 hdr.dirlist = 0;
275 memset(hdr.spare, 0, sizeof hdr.spare);
276
277 /* Count up the size of the string table. */
278 if (ndirs > 0) {
279 hdr.strsize += strlen(dirs[0]);
280 for (i = 1; i < ndirs; i++)
281 hdr.strsize += 1 + strlen(dirs[i]);
282 }
283 hdr.dirlistlen = hdr.strsize;
284 hdr.strsize++; /* For the null terminator */
285
286 /* Write the header. */
287 if (fwrite(&hdr, 1, sizeof hdr, fp) != sizeof hdr)
288 err(1, "%s: write error", tempname);
289 /* Write the strings. */
290 if (ndirs > 0) {
291 if (fputs(dirs[0], fp) == EOF)
292 err(1, "%s: write error", tempname);
293 for (i = 1; i < ndirs; i++)
294 if (fprintf(fp, ":%s", dirs[i]) < 0)
295 err(1, "%s: write error", tempname);
296 }
297 if (putc('\0', fp) == EOF || fclose(fp) == EOF)
298 err(1, "%s: write error", tempname);
299
300 if (rename(tempname, hintsfile) == -1)
301 err(1, "rename %s to %s", tempname, hintsfile);
302 free(tempname);
303 }
304