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 "rtld_paths.h"
20 #include "rtld_libc.h"
21
22 TAILQ_HEAD(lm_list, lm);
23 struct lm {
24 char *f;
25 char *t;
26 TAILQ_ENTRY(lm) lm_link;
27 };
28
29 static TAILQ_HEAD(lmp_list, lmp) lmp_head = TAILQ_HEAD_INITIALIZER(lmp_head);
30 struct lmp {
31 char *p;
32 enum { T_EXACT=0, T_BASENAME, T_DIRECTORY } type;
33 struct lm_list lml;
34 TAILQ_ENTRY(lmp) lmp_link;
35 };
36
37 static TAILQ_HEAD(lmc_list, lmc) lmc_head = TAILQ_HEAD_INITIALIZER(lmc_head);
38 struct lmc {
39 char *path;
40 dev_t dev;
41 ino_t ino;
42 TAILQ_ENTRY(lmc) next;
43 };
44
45 static int lm_count;
46
47 static void lmc_parse(char *, size_t);
48 static void lmc_parse_file(const char *);
49 static void lmc_parse_dir(const char *);
50 static void lm_add(const char *, const char *, const char *);
51 static void lm_free(struct lm_list *);
52 static char *lml_find(struct lm_list *, const char *);
53 static struct lm_list *lmp_find(const char *);
54 static struct lm_list *lmp_init(char *);
55 static const char *quickbasename(const char *);
56
57 #define iseol(c) (((c) == '#') || ((c) == '\0') || \
58 ((c) == '\n') || ((c) == '\r'))
59
60 /*
61 * Do not use ctype.h macros, which rely on working TLS. It is
62 * too early to have thread-local variables functional.
63 */
64 #define rtld_isspace(c) ((c) == ' ' || (c) == '\t')
65
66 int
lm_init(const char * libmap_override)67 lm_init(const char *libmap_override)
68 {
69 char *l, *p;
70
71 dbg("lm_init(\"%s\")", libmap_override);
72 TAILQ_INIT(&lmp_head);
73
74 lmc_parse_file(ld_path_libmap_conf);
75
76 if (libmap_override != NULL) {
77 /*
78 * Do some character replacement to make $LDLIBMAP look
79 * like a text file, then parse it.
80 */
81 l = xstrdup(libmap_override);
82 for (p = l; *p != 0; p++) {
83 switch (*p) {
84 case '=':
85 *p = ' ';
86 break;
87 case ',':
88 *p = '\n';
89 break;
90 }
91 }
92 lmc_parse(l, p - l);
93 free(l);
94 }
95
96 return (lm_count == 0);
97 }
98
99 static void
lmc_parse_file(const char * path)100 lmc_parse_file(const char *path)
101 {
102 struct lmc *p;
103 char *lm_map;
104 struct stat st;
105 ssize_t retval;
106 int fd, saved_errno;
107
108 TAILQ_FOREACH(p, &lmc_head, next) {
109 if (strcmp(p->path, path) == 0)
110 return;
111 }
112
113 fd = open(path, O_RDONLY | O_CLOEXEC);
114 if (fd == -1) {
115 dbg("lm_parse_file: open(\"%s\") failed, %s", path,
116 rtld_strerror(errno));
117 return;
118 }
119 if (fstat(fd, &st) == -1) {
120 dbg("lm_parse_file: fstat(\"%s\") failed, %s", path,
121 rtld_strerror(errno));
122 close(fd);
123 return;
124 }
125
126 TAILQ_FOREACH(p, &lmc_head, next) {
127 if (p->dev == st.st_dev && p->ino == st.st_ino) {
128 close(fd);
129 return;
130 }
131 }
132
133 lm_map = xmalloc(st.st_size);
134 retval = read(fd, lm_map, st.st_size);
135 saved_errno = errno;
136 close(fd);
137 if (retval != st.st_size) {
138 if (retval == -1) {
139 dbg("lm_parse_file: read(\"%s\") failed, %s", path,
140 rtld_strerror(saved_errno));
141 } else {
142 dbg("lm_parse_file: short read(\"%s\"), %zd vs %jd",
143 path, retval, (uintmax_t)st.st_size);
144 }
145 free(lm_map);
146 return;
147 }
148 p = xmalloc(sizeof(struct lmc));
149 p->path = xstrdup(path);
150 p->dev = st.st_dev;
151 p->ino = st.st_ino;
152 TAILQ_INSERT_HEAD(&lmc_head, p, next);
153 lmc_parse(lm_map, st.st_size);
154 free(lm_map);
155 }
156
157 static void
lmc_parse_dir(const char * idir)158 lmc_parse_dir(const char *idir)
159 {
160 DIR *d;
161 struct dirent *dp;
162 struct lmc *p;
163 char conffile[MAXPATHLEN];
164 char *ext;
165
166 TAILQ_FOREACH(p, &lmc_head, next) {
167 if (strcmp(p->path, idir) == 0)
168 return;
169 }
170 d = opendir(idir);
171 if (d == NULL)
172 return;
173
174 p = xmalloc(sizeof(struct lmc));
175 p->path = xstrdup(idir);
176 p->dev = NODEV;
177 p->ino = 0;
178 TAILQ_INSERT_HEAD(&lmc_head, p, next);
179
180 while ((dp = readdir(d)) != NULL) {
181 if (dp->d_ino == 0)
182 continue;
183 if (dp->d_type != DT_REG)
184 continue;
185 ext = strrchr(dp->d_name, '.');
186 if (ext == NULL)
187 continue;
188 if (strcmp(ext, ".conf") != 0)
189 continue;
190 if (strlcpy(conffile, idir, MAXPATHLEN) >= MAXPATHLEN)
191 continue; /* too long */
192 if (strlcat(conffile, "/", MAXPATHLEN) >= MAXPATHLEN)
193 continue; /* too long */
194 if (strlcat(conffile, dp->d_name, MAXPATHLEN) >= MAXPATHLEN)
195 continue; /* too long */
196 lmc_parse_file(conffile);
197 }
198 closedir(d);
199 }
200
201 static void
lmc_parse(char * lm_p,size_t lm_len)202 lmc_parse(char *lm_p, size_t lm_len)
203 {
204 char *cp, *f, *t, *c, *p;
205 char prog[MAXPATHLEN];
206 /* allow includedir + full length path */
207 char line[MAXPATHLEN + 13];
208 size_t cnt, i;
209
210 cnt = 0;
211 p = NULL;
212 while (cnt < lm_len) {
213 i = 0;
214 while (cnt < lm_len && lm_p[cnt] != '\n' &&
215 i < sizeof(line) - 1) {
216 line[i] = lm_p[cnt];
217 cnt++;
218 i++;
219 }
220 line[i] = '\0';
221 while (cnt < lm_len && lm_p[cnt] != '\n')
222 cnt++;
223 /* skip over nl */
224 cnt++;
225
226 cp = &line[0];
227 t = f = c = NULL;
228
229 /* Skip over leading space */
230 while (rtld_isspace(*cp))
231 cp++;
232
233 /* Found a comment or EOL */
234 if (iseol(*cp))
235 continue;
236
237 /* Found a constraint selector */
238 if (*cp == '[') {
239 cp++;
240
241 /* Skip leading space */
242 while (rtld_isspace(*cp))
243 cp++;
244
245 /* Found comment, EOL or end of selector */
246 if (iseol(*cp) || *cp == ']')
247 continue;
248
249 c = cp++;
250 /* Skip to end of word */
251 while (!rtld_isspace(*cp) && !iseol(*cp) && *cp != ']')
252 cp++;
253
254 /* Skip and zero out trailing space */
255 while (rtld_isspace(*cp))
256 *cp++ = '\0';
257
258 /* Check if there is a closing brace */
259 if (*cp != ']')
260 continue;
261
262 /* Terminate string if there was no trailing space */
263 *cp++ = '\0';
264
265 /*
266 * There should be nothing except whitespace or comment
267 from this point to the end of the line.
268 */
269 while (rtld_isspace(*cp))
270 cp++;
271 if (!iseol(*cp))
272 continue;
273
274 if (strlcpy(prog, c, sizeof prog) >= sizeof prog)
275 continue;
276 p = prog;
277 continue;
278 }
279
280 /* Parse the 'from' candidate. */
281 f = cp++;
282 while (!rtld_isspace(*cp) && !iseol(*cp))
283 cp++;
284
285 /* Skip and zero out the trailing whitespace */
286 while (rtld_isspace(*cp))
287 *cp++ = '\0';
288
289 /* Found a comment or EOL */
290 if (iseol(*cp))
291 continue;
292
293 /* Parse 'to' mapping */
294 t = cp++;
295 while (!rtld_isspace(*cp) && !iseol(*cp))
296 cp++;
297
298 /* Skip and zero out the trailing whitespace */
299 while (rtld_isspace(*cp))
300 *cp++ = '\0';
301
302 /* Should be no extra tokens at this point */
303 if (!iseol(*cp))
304 continue;
305
306 *cp = '\0';
307 if (strcmp(f, "includedir") == 0)
308 lmc_parse_dir(t);
309 else if (strcmp(f, "include") == 0)
310 lmc_parse_file(t);
311 else
312 lm_add(p, f, t);
313 }
314 }
315
316 static void
lm_free(struct lm_list * lml)317 lm_free(struct lm_list *lml)
318 {
319 struct lm *lm;
320
321 dbg("%s(%p)", __func__, lml);
322
323 while (!TAILQ_EMPTY(lml)) {
324 lm = TAILQ_FIRST(lml);
325 TAILQ_REMOVE(lml, lm, lm_link);
326 free(lm->f);
327 free(lm->t);
328 free(lm);
329 }
330 }
331
332 void
lm_fini(void)333 lm_fini(void)
334 {
335 struct lmp *lmp;
336 struct lmc *p;
337
338 dbg("%s()", __func__);
339
340 while (!TAILQ_EMPTY(&lmc_head)) {
341 p = TAILQ_FIRST(&lmc_head);
342 TAILQ_REMOVE(&lmc_head, p, next);
343 free(p->path);
344 free(p);
345 }
346
347 while (!TAILQ_EMPTY(&lmp_head)) {
348 lmp = TAILQ_FIRST(&lmp_head);
349 TAILQ_REMOVE(&lmp_head, lmp, lmp_link);
350 free(lmp->p);
351 lm_free(&lmp->lml);
352 free(lmp);
353 }
354 }
355
356 static void
lm_add(const char * p,const char * f,const char * t)357 lm_add(const char *p, const char *f, const char *t)
358 {
359 struct lm_list *lml;
360 struct lm *lm;
361 const char *t1;
362
363 if (p == NULL)
364 p = "$DEFAULT$";
365
366 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t);
367
368 if ((lml = lmp_find(p)) == NULL)
369 lml = lmp_init(xstrdup(p));
370
371 t1 = lml_find(lml, f);
372 if (t1 == NULL || strcmp(t1, t) != 0) {
373 lm = xmalloc(sizeof(struct lm));
374 lm->f = xstrdup(f);
375 lm->t = xstrdup(t);
376 TAILQ_INSERT_HEAD(lml, lm, lm_link);
377 lm_count++;
378 }
379 }
380
381 char *
lm_find(const char * p,const char * f)382 lm_find(const char *p, const char *f)
383 {
384 struct lm_list *lml;
385 char *t;
386
387 dbg("%s(\"%s\", \"%s\")", __func__, p, f);
388
389 if (p != NULL && (lml = lmp_find(p)) != NULL) {
390 t = lml_find(lml, f);
391 if (t != NULL) {
392 /*
393 * Add a global mapping if we have
394 * a successful constrained match.
395 */
396 lm_add(NULL, f, t);
397 return (t);
398 }
399 }
400 lml = lmp_find("$DEFAULT$");
401 if (lml != NULL)
402 return (lml_find(lml, f));
403 return (NULL);
404 }
405
406 /*
407 * Given a libmap translation list and a library name, return the
408 * replacement library, or NULL.
409 */
410 char *
lm_findn(const char * p,const char * f,const size_t n)411 lm_findn(const char *p, const char *f, const size_t n)
412 {
413 char pathbuf[64], *s, *t;
414
415 if (n < sizeof(pathbuf) - 1)
416 s = pathbuf;
417 else
418 s = xmalloc(n + 1);
419 memcpy(s, f, n);
420 s[n] = '\0';
421 t = lm_find(p, s);
422 if (s != pathbuf)
423 free(s);
424 return (t);
425 }
426
427 static char *
lml_find(struct lm_list * lmh,const char * f)428 lml_find(struct lm_list *lmh, const char *f)
429 {
430 struct lm *lm;
431
432 dbg("%s(%p, \"%s\")", __func__, lmh, f);
433
434 TAILQ_FOREACH(lm, lmh, lm_link) {
435 if (strcmp(f, lm->f) == 0)
436 return (lm->t);
437 }
438 return (NULL);
439 }
440
441 /*
442 * Given an executable name, return a pointer to the translation list or
443 * NULL if no matches.
444 */
445 static struct lm_list *
lmp_find(const char * n)446 lmp_find(const char *n)
447 {
448 struct lmp *lmp;
449
450 dbg("%s(\"%s\")", __func__, n);
451
452 TAILQ_FOREACH(lmp, &lmp_head, lmp_link) {
453 if ((lmp->type == T_EXACT && strcmp(n, lmp->p) == 0) ||
454 (lmp->type == T_DIRECTORY && strncmp(n, lmp->p,
455 strlen(lmp->p)) == 0) ||
456 (lmp->type == T_BASENAME && strcmp(quickbasename(n),
457 lmp->p) == 0))
458 return (&lmp->lml);
459 }
460 return (NULL);
461 }
462
463 static struct lm_list *
lmp_init(char * n)464 lmp_init(char *n)
465 {
466 struct lmp *lmp;
467
468 dbg("%s(\"%s\")", __func__, n);
469
470 lmp = xmalloc(sizeof(struct lmp));
471 lmp->p = n;
472 if (n[strlen(n) - 1] == '/')
473 lmp->type = T_DIRECTORY;
474 else if (strchr(n,'/') == NULL)
475 lmp->type = T_BASENAME;
476 else
477 lmp->type = T_EXACT;
478 TAILQ_INIT(&lmp->lml);
479 TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link);
480
481 return (&lmp->lml);
482 }
483
484 /*
485 * libc basename is overkill. Return a pointer to the character after
486 * the last /, or the original string if there are no slashes.
487 */
488 static const char *
quickbasename(const char * path)489 quickbasename(const char *path)
490 {
491 const char *p;
492
493 for (p = path; *path != '\0'; path++) {
494 if (*path == '/')
495 p = path + 1;
496 }
497 return (p);
498 }
499