1 /*
2 * $FreeBSD$
3 */
4
5 #include <sys/types.h>
6 #include <sys/param.h>
7 #include <sys/fcntl.h>
8 #include <sys/mman.h>
9 #include <sys/queue.h>
10 #include <sys/stat.h>
11 #include <dirent.h>
12 #include <errno.h>
13 #include <stdlib.h>
14 #include <string.h>
15
16 #include "debug.h"
17 #include "rtld.h"
18 #include "libmap.h"
19 #include "paths.h"
20
21 TAILQ_HEAD(lm_list, lm);
22 struct lm {
23 char *f;
24 char *t;
25 TAILQ_ENTRY(lm) lm_link;
26 };
27
28 static TAILQ_HEAD(lmp_list, lmp) lmp_head = TAILQ_HEAD_INITIALIZER(lmp_head);
29 struct lmp {
30 char *p;
31 enum { T_EXACT=0, T_BASENAME, T_DIRECTORY } type;
32 struct lm_list lml;
33 TAILQ_ENTRY(lmp) lmp_link;
34 };
35
36 static TAILQ_HEAD(lmc_list, lmc) lmc_head = TAILQ_HEAD_INITIALIZER(lmc_head);
37 struct lmc {
38 char *path;
39 dev_t dev;
40 ino_t ino;
41 TAILQ_ENTRY(lmc) next;
42 };
43
44 static int lm_count;
45
46 static void lmc_parse(char *, size_t);
47 static void lmc_parse_file(const char *);
48 static void lmc_parse_dir(const char *);
49 static void lm_add(const char *, const char *, const char *);
50 static void lm_free(struct lm_list *);
51 static char *lml_find(struct lm_list *, const char *);
52 static struct lm_list *lmp_find(const char *);
53 static struct lm_list *lmp_init(char *);
54 static const char *quickbasename(const char *);
55
56 #define iseol(c) (((c) == '#') || ((c) == '\0') || \
57 ((c) == '\n') || ((c) == '\r'))
58
59 /*
60 * Do not use ctype.h macros, which rely on working TLS. It is
61 * too early to have thread-local variables functional.
62 */
63 #define rtld_isspace(c) ((c) == ' ' || (c) == '\t')
64
65 int
lm_init(char * libmap_override)66 lm_init(char *libmap_override)
67 {
68 char *p;
69
70 dbg("lm_init(\"%s\")", libmap_override);
71 TAILQ_INIT(&lmp_head);
72
73 lmc_parse_file(ld_path_libmap_conf);
74
75 if (libmap_override) {
76 /*
77 * Do some character replacement to make $LDLIBMAP look
78 * like a text file, then parse it.
79 */
80 libmap_override = xstrdup(libmap_override);
81 for (p = libmap_override; *p; p++) {
82 switch (*p) {
83 case '=':
84 *p = ' ';
85 break;
86 case ',':
87 *p = '\n';
88 break;
89 }
90 }
91 lmc_parse(libmap_override, p - libmap_override);
92 free(libmap_override);
93 }
94
95 return (lm_count == 0);
96 }
97
98 static void
lmc_parse_file(const char * path)99 lmc_parse_file(const char *path)
100 {
101 struct lmc *p;
102 char *lm_map;
103 struct stat st;
104 ssize_t retval;
105 int fd;
106
107 TAILQ_FOREACH(p, &lmc_head, next) {
108 if (strcmp(p->path, path) == 0)
109 return;
110 }
111
112 fd = open(path, O_RDONLY | O_CLOEXEC);
113 if (fd == -1) {
114 dbg("lm_parse_file: open(\"%s\") failed, %s", path,
115 rtld_strerror(errno));
116 return;
117 }
118 if (fstat(fd, &st) == -1) {
119 close(fd);
120 dbg("lm_parse_file: fstat(\"%s\") failed, %s", path,
121 rtld_strerror(errno));
122 return;
123 }
124
125 TAILQ_FOREACH(p, &lmc_head, next) {
126 if (p->dev == st.st_dev && p->ino == st.st_ino) {
127 close(fd);
128 return;
129 }
130 }
131
132 lm_map = xmalloc(st.st_size);
133 retval = read(fd, lm_map, st.st_size);
134 if (retval != st.st_size) {
135 close(fd);
136 free(lm_map);
137 dbg("lm_parse_file: read(\"%s\") failed, %s", path,
138 rtld_strerror(errno));
139 return;
140 }
141 close(fd);
142 p = xmalloc(sizeof(struct lmc));
143 p->path = xstrdup(path);
144 p->dev = st.st_dev;
145 p->ino = st.st_ino;
146 TAILQ_INSERT_HEAD(&lmc_head, p, next);
147 lmc_parse(lm_map, st.st_size);
148 free(lm_map);
149 }
150
151 static void
lmc_parse_dir(const char * idir)152 lmc_parse_dir(const char *idir)
153 {
154 DIR *d;
155 struct dirent *dp;
156 struct lmc *p;
157 char conffile[MAXPATHLEN];
158 char *ext;
159
160 TAILQ_FOREACH(p, &lmc_head, next) {
161 if (strcmp(p->path, idir) == 0)
162 return;
163 }
164 d = opendir(idir);
165 if (d == NULL)
166 return;
167
168 p = xmalloc(sizeof(struct lmc));
169 p->path = xstrdup(idir);
170 p->dev = NODEV;
171 p->ino = 0;
172 TAILQ_INSERT_HEAD(&lmc_head, p, next);
173
174 while ((dp = readdir(d)) != NULL) {
175 if (dp->d_ino == 0)
176 continue;
177 if (dp->d_type != DT_REG)
178 continue;
179 ext = strrchr(dp->d_name, '.');
180 if (ext == NULL)
181 continue;
182 if (strcmp(ext, ".conf") != 0)
183 continue;
184 if (strlcpy(conffile, idir, MAXPATHLEN) >= MAXPATHLEN)
185 continue; /* too long */
186 if (strlcat(conffile, "/", MAXPATHLEN) >= MAXPATHLEN)
187 continue; /* too long */
188 if (strlcat(conffile, dp->d_name, MAXPATHLEN) >= MAXPATHLEN)
189 continue; /* too long */
190 lmc_parse_file(conffile);
191 }
192 closedir(d);
193 }
194
195 static void
lmc_parse(char * lm_p,size_t lm_len)196 lmc_parse(char *lm_p, size_t lm_len)
197 {
198 char *cp, *f, *t, *c, *p;
199 char prog[MAXPATHLEN];
200 /* allow includedir + full length path */
201 char line[MAXPATHLEN + 13];
202 size_t cnt, i;
203
204 cnt = 0;
205 p = NULL;
206 while (cnt < lm_len) {
207 i = 0;
208 while (cnt < lm_len && lm_p[cnt] != '\n' &&
209 i < sizeof(line) - 1) {
210 line[i] = lm_p[cnt];
211 cnt++;
212 i++;
213 }
214 line[i] = '\0';
215 while (cnt < lm_len && lm_p[cnt] != '\n')
216 cnt++;
217 /* skip over nl */
218 cnt++;
219
220 cp = &line[0];
221 t = f = c = NULL;
222
223 /* Skip over leading space */
224 while (rtld_isspace(*cp))
225 cp++;
226
227 /* Found a comment or EOL */
228 if (iseol(*cp))
229 continue;
230
231 /* Found a constraint selector */
232 if (*cp == '[') {
233 cp++;
234
235 /* Skip leading space */
236 while (rtld_isspace(*cp))
237 cp++;
238
239 /* Found comment, EOL or end of selector */
240 if (iseol(*cp) || *cp == ']')
241 continue;
242
243 c = cp++;
244 /* Skip to end of word */
245 while (!rtld_isspace(*cp) && !iseol(*cp) && *cp != ']')
246 cp++;
247
248 /* Skip and zero out trailing space */
249 while (rtld_isspace(*cp))
250 *cp++ = '\0';
251
252 /* Check if there is a closing brace */
253 if (*cp != ']')
254 continue;
255
256 /* Terminate string if there was no trailing space */
257 *cp++ = '\0';
258
259 /*
260 * There should be nothing except whitespace or comment
261 from this point to the end of the line.
262 */
263 while (rtld_isspace(*cp))
264 cp++;
265 if (!iseol(*cp))
266 continue;
267
268 if (strlcpy(prog, c, sizeof prog) >= sizeof prog)
269 continue;
270 p = prog;
271 continue;
272 }
273
274 /* Parse the 'from' candidate. */
275 f = cp++;
276 while (!rtld_isspace(*cp) && !iseol(*cp))
277 cp++;
278
279 /* Skip and zero out the trailing whitespace */
280 while (rtld_isspace(*cp))
281 *cp++ = '\0';
282
283 /* Found a comment or EOL */
284 if (iseol(*cp))
285 continue;
286
287 /* Parse 'to' mapping */
288 t = cp++;
289 while (!rtld_isspace(*cp) && !iseol(*cp))
290 cp++;
291
292 /* Skip and zero out the trailing whitespace */
293 while (rtld_isspace(*cp))
294 *cp++ = '\0';
295
296 /* Should be no extra tokens at this point */
297 if (!iseol(*cp))
298 continue;
299
300 *cp = '\0';
301 if (strcmp(f, "includedir") == 0)
302 lmc_parse_dir(t);
303 else if (strcmp(f, "include") == 0)
304 lmc_parse_file(t);
305 else
306 lm_add(p, f, t);
307 }
308 }
309
310 static void
lm_free(struct lm_list * lml)311 lm_free(struct lm_list *lml)
312 {
313 struct lm *lm;
314
315 dbg("%s(%p)", __func__, lml);
316
317 while (!TAILQ_EMPTY(lml)) {
318 lm = TAILQ_FIRST(lml);
319 TAILQ_REMOVE(lml, lm, lm_link);
320 free(lm->f);
321 free(lm->t);
322 free(lm);
323 }
324 }
325
326 void
lm_fini(void)327 lm_fini(void)
328 {
329 struct lmp *lmp;
330 struct lmc *p;
331
332 dbg("%s()", __func__);
333
334 while (!TAILQ_EMPTY(&lmc_head)) {
335 p = TAILQ_FIRST(&lmc_head);
336 TAILQ_REMOVE(&lmc_head, p, next);
337 free(p->path);
338 free(p);
339 }
340
341 while (!TAILQ_EMPTY(&lmp_head)) {
342 lmp = TAILQ_FIRST(&lmp_head);
343 TAILQ_REMOVE(&lmp_head, lmp, lmp_link);
344 free(lmp->p);
345 lm_free(&lmp->lml);
346 free(lmp);
347 }
348 }
349
350 static void
lm_add(const char * p,const char * f,const char * t)351 lm_add(const char *p, const char *f, const char *t)
352 {
353 struct lm_list *lml;
354 struct lm *lm;
355 const char *t1;
356
357 if (p == NULL)
358 p = "$DEFAULT$";
359
360 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t);
361
362 if ((lml = lmp_find(p)) == NULL)
363 lml = lmp_init(xstrdup(p));
364
365 t1 = lml_find(lml, f);
366 if (t1 == NULL || strcmp(t1, t) != 0) {
367 lm = xmalloc(sizeof(struct lm));
368 lm->f = xstrdup(f);
369 lm->t = xstrdup(t);
370 TAILQ_INSERT_HEAD(lml, lm, lm_link);
371 lm_count++;
372 }
373 }
374
375 char *
lm_find(const char * p,const char * f)376 lm_find(const char *p, const char *f)
377 {
378 struct lm_list *lml;
379 char *t;
380
381 dbg("%s(\"%s\", \"%s\")", __func__, p, f);
382
383 if (p != NULL && (lml = lmp_find(p)) != NULL) {
384 t = lml_find(lml, f);
385 if (t != NULL) {
386 /*
387 * Add a global mapping if we have
388 * a successful constrained match.
389 */
390 lm_add(NULL, f, t);
391 return (t);
392 }
393 }
394 lml = lmp_find("$DEFAULT$");
395 if (lml != NULL)
396 return (lml_find(lml, f));
397 return (NULL);
398 }
399
400 /*
401 * Given a libmap translation list and a library name, return the
402 * replacement library, or NULL.
403 */
404 char *
lm_findn(const char * p,const char * f,const size_t n)405 lm_findn(const char *p, const char *f, const size_t n)
406 {
407 char pathbuf[64], *s, *t;
408
409 if (n < sizeof(pathbuf) - 1)
410 s = pathbuf;
411 else
412 s = xmalloc(n + 1);
413 memcpy(s, f, n);
414 s[n] = '\0';
415 t = lm_find(p, s);
416 if (s != pathbuf)
417 free(s);
418 return (t);
419 }
420
421 static char *
lml_find(struct lm_list * lmh,const char * f)422 lml_find(struct lm_list *lmh, const char *f)
423 {
424 struct lm *lm;
425
426 dbg("%s(%p, \"%s\")", __func__, lmh, f);
427
428 TAILQ_FOREACH(lm, lmh, lm_link) {
429 if (strcmp(f, lm->f) == 0)
430 return (lm->t);
431 }
432 return (NULL);
433 }
434
435 /*
436 * Given an executable name, return a pointer to the translation list or
437 * NULL if no matches.
438 */
439 static struct lm_list *
lmp_find(const char * n)440 lmp_find(const char *n)
441 {
442 struct lmp *lmp;
443
444 dbg("%s(\"%s\")", __func__, n);
445
446 TAILQ_FOREACH(lmp, &lmp_head, lmp_link) {
447 if ((lmp->type == T_EXACT && strcmp(n, lmp->p) == 0) ||
448 (lmp->type == T_DIRECTORY && strncmp(n, lmp->p,
449 strlen(lmp->p)) == 0) ||
450 (lmp->type == T_BASENAME && strcmp(quickbasename(n),
451 lmp->p) == 0))
452 return (&lmp->lml);
453 }
454 return (NULL);
455 }
456
457 static struct lm_list *
lmp_init(char * n)458 lmp_init(char *n)
459 {
460 struct lmp *lmp;
461
462 dbg("%s(\"%s\")", __func__, n);
463
464 lmp = xmalloc(sizeof(struct lmp));
465 lmp->p = n;
466 if (n[strlen(n) - 1] == '/')
467 lmp->type = T_DIRECTORY;
468 else if (strchr(n,'/') == NULL)
469 lmp->type = T_BASENAME;
470 else
471 lmp->type = T_EXACT;
472 TAILQ_INIT(&lmp->lml);
473 TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link);
474
475 return (&lmp->lml);
476 }
477
478 /*
479 * libc basename is overkill. Return a pointer to the character after
480 * the last /, or the original string if there are no slashes.
481 */
482 static const char *
quickbasename(const char * path)483 quickbasename(const char *path)
484 {
485 const char *p;
486
487 for (p = path; *path != '\0'; path++) {
488 if (*path == '/')
489 p = path + 1;
490 }
491 return (p);
492 }
493