1 /*
2 */
3
4 #include <sys/types.h>
5 #include <sys/param.h>
6 #include <sys/fcntl.h>
7 #include <sys/mman.h>
8 #include <sys/queue.h>
9 #include <sys/stat.h>
10 #include <dirent.h>
11 #include <errno.h>
12 #include <stdlib.h>
13 #include <string.h>
14
15 #include "debug.h"
16 #include "rtld.h"
17 #include "libmap.h"
18 #include "rtld_paths.h"
19 #include "rtld_libc.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. Rtld does
61 * not support TLS for itself.
62 */
63 #define rtld_isspace(c) ((c) == ' ' || (c) == '\t')
64
65 int
lm_init(const char * libmap_override)66 lm_init(const char *libmap_override)
67 {
68 char *l, *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 != NULL) {
76 /*
77 * Do some character replacement to make $LD_LIBMAP look
78 * like a text file, then parse it.
79 */
80 l = xstrdup(libmap_override);
81 for (p = l; *p != 0; p++) {
82 switch (*p) {
83 case '=':
84 *p = ' ';
85 break;
86 case ',':
87 *p = '\n';
88 break;
89 }
90 }
91 lmc_parse(l, p - l);
92 free(l);
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, saved_errno;
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 dbg("lm_parse_file: fstat(\"%s\") failed, %s", path,
120 rtld_strerror(errno));
121 close(fd);
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 saved_errno = errno;
135 close(fd);
136 if (retval != st.st_size) {
137 if (retval == -1) {
138 dbg("lm_parse_file: read(\"%s\") failed, %s", path,
139 rtld_strerror(saved_errno));
140 } else {
141 dbg("lm_parse_file: short read(\"%s\"), %zd vs %jd",
142 path, retval, (uintmax_t)st.st_size);
143 }
144 free(lm_map);
145 return;
146 }
147 p = xmalloc(sizeof(struct lmc));
148 p->path = xstrdup(path);
149 p->dev = st.st_dev;
150 p->ino = st.st_ino;
151 TAILQ_INSERT_HEAD(&lmc_head, p, next);
152 lmc_parse(lm_map, st.st_size);
153 free(lm_map);
154 }
155
156 static void
lmc_parse_dir(const char * idir)157 lmc_parse_dir(const char *idir)
158 {
159 DIR *d;
160 struct dirent *dp;
161 struct lmc *p;
162 char conffile[MAXPATHLEN];
163 char *ext;
164
165 TAILQ_FOREACH(p, &lmc_head, next) {
166 if (strcmp(p->path, idir) == 0)
167 return;
168 }
169 d = opendir(idir);
170 if (d == NULL)
171 return;
172
173 p = xmalloc(sizeof(struct lmc));
174 p->path = xstrdup(idir);
175 p->dev = NODEV;
176 p->ino = 0;
177 TAILQ_INSERT_HEAD(&lmc_head, p, next);
178
179 while ((dp = readdir(d)) != NULL) {
180 if (dp->d_ino == 0)
181 continue;
182 if (dp->d_type != DT_REG)
183 continue;
184 ext = strrchr(dp->d_name, '.');
185 if (ext == NULL)
186 continue;
187 if (strcmp(ext, ".conf") != 0)
188 continue;
189 if (strlcpy(conffile, idir, MAXPATHLEN) >= MAXPATHLEN)
190 continue; /* too long */
191 if (strlcat(conffile, "/", MAXPATHLEN) >= MAXPATHLEN)
192 continue; /* too long */
193 if (strlcat(conffile, dp->d_name, MAXPATHLEN) >= MAXPATHLEN)
194 continue; /* too long */
195 lmc_parse_file(conffile);
196 }
197 closedir(d);
198 }
199
200 static void
lmc_parse(char * lm_p,size_t lm_len)201 lmc_parse(char *lm_p, size_t lm_len)
202 {
203 char *cp, *f, *t, *c, *p;
204 char prog[MAXPATHLEN];
205 /* allow includedir + full length path */
206 char line[MAXPATHLEN + 13];
207 size_t cnt, i;
208
209 cnt = 0;
210 p = NULL;
211 while (cnt < lm_len) {
212 i = 0;
213 while (cnt < lm_len && lm_p[cnt] != '\n' &&
214 i < sizeof(line) - 1) {
215 line[i] = lm_p[cnt];
216 cnt++;
217 i++;
218 }
219 line[i] = '\0';
220 while (cnt < lm_len && lm_p[cnt] != '\n')
221 cnt++;
222 /* skip over nl */
223 cnt++;
224
225 cp = &line[0];
226 t = f = c = NULL;
227
228 /* Skip over leading space */
229 while (rtld_isspace(*cp))
230 cp++;
231
232 /* Found a comment or EOL */
233 if (iseol(*cp))
234 continue;
235
236 /* Found a constraint selector */
237 if (*cp == '[') {
238 cp++;
239
240 /* Skip leading space */
241 while (rtld_isspace(*cp))
242 cp++;
243
244 /* Found comment, EOL or end of selector */
245 if (iseol(*cp) || *cp == ']')
246 continue;
247
248 c = cp++;
249 /* Skip to end of word */
250 while (!rtld_isspace(*cp) && !iseol(*cp) && *cp != ']')
251 cp++;
252
253 /* Skip and zero out trailing space */
254 while (rtld_isspace(*cp))
255 *cp++ = '\0';
256
257 /* Check if there is a closing brace */
258 if (*cp != ']')
259 continue;
260
261 /* Terminate string if there was no trailing space */
262 *cp++ = '\0';
263
264 /*
265 * There should be nothing except whitespace or comment
266 from this point to the end of the line.
267 */
268 while (rtld_isspace(*cp))
269 cp++;
270 if (!iseol(*cp))
271 continue;
272
273 if (strlcpy(prog, c, sizeof prog) >= sizeof prog)
274 continue;
275 p = prog;
276 continue;
277 }
278
279 /* Parse the 'from' candidate. */
280 f = cp++;
281 while (!rtld_isspace(*cp) && !iseol(*cp))
282 cp++;
283
284 /* Skip and zero out the trailing whitespace */
285 while (rtld_isspace(*cp))
286 *cp++ = '\0';
287
288 /* Found a comment or EOL */
289 if (iseol(*cp))
290 continue;
291
292 /* Parse 'to' mapping */
293 t = cp++;
294 while (!rtld_isspace(*cp) && !iseol(*cp))
295 cp++;
296
297 /* Skip and zero out the trailing whitespace */
298 while (rtld_isspace(*cp))
299 *cp++ = '\0';
300
301 /* Should be no extra tokens at this point */
302 if (!iseol(*cp))
303 continue;
304
305 *cp = '\0';
306 if (strcmp(f, "includedir") == 0)
307 lmc_parse_dir(t);
308 else if (strcmp(f, "include") == 0)
309 lmc_parse_file(t);
310 else
311 lm_add(p, f, t);
312 }
313 }
314
315 static void
lm_free(struct lm_list * lml)316 lm_free(struct lm_list *lml)
317 {
318 struct lm *lm;
319
320 dbg("%s(%p)", __func__, lml);
321
322 while (!TAILQ_EMPTY(lml)) {
323 lm = TAILQ_FIRST(lml);
324 TAILQ_REMOVE(lml, lm, lm_link);
325 free(lm->f);
326 free(lm->t);
327 free(lm);
328 }
329 }
330
331 void
lm_fini(void)332 lm_fini(void)
333 {
334 struct lmp *lmp;
335 struct lmc *p;
336
337 dbg("%s()", __func__);
338
339 while (!TAILQ_EMPTY(&lmc_head)) {
340 p = TAILQ_FIRST(&lmc_head);
341 TAILQ_REMOVE(&lmc_head, p, next);
342 free(p->path);
343 free(p);
344 }
345
346 while (!TAILQ_EMPTY(&lmp_head)) {
347 lmp = TAILQ_FIRST(&lmp_head);
348 TAILQ_REMOVE(&lmp_head, lmp, lmp_link);
349 free(lmp->p);
350 lm_free(&lmp->lml);
351 free(lmp);
352 }
353 }
354
355 static void
lm_add(const char * p,const char * f,const char * t)356 lm_add(const char *p, const char *f, const char *t)
357 {
358 struct lm_list *lml;
359 struct lm *lm;
360 const char *t1;
361
362 if (p == NULL)
363 p = "$DEFAULT$";
364
365 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t);
366
367 if ((lml = lmp_find(p)) == NULL)
368 lml = lmp_init(xstrdup(p));
369
370 t1 = lml_find(lml, f);
371 if (t1 == NULL || strcmp(t1, t) != 0) {
372 lm = xmalloc(sizeof(struct lm));
373 lm->f = xstrdup(f);
374 lm->t = xstrdup(t);
375 TAILQ_INSERT_HEAD(lml, lm, lm_link);
376 lm_count++;
377 }
378 }
379
380 char *
lm_find(const char * p,const char * f)381 lm_find(const char *p, const char *f)
382 {
383 struct lm_list *lml;
384 char *t;
385
386 dbg("%s(\"%s\", \"%s\")", __func__, p, f);
387
388 if (p != NULL && (lml = lmp_find(p)) != NULL) {
389 t = lml_find(lml, f);
390 if (t != NULL) {
391 /*
392 * Add a global mapping if we have
393 * a successful constrained match.
394 */
395 lm_add(NULL, f, t);
396 return (t);
397 }
398 }
399 lml = lmp_find("$DEFAULT$");
400 if (lml != NULL)
401 return (lml_find(lml, f));
402 return (NULL);
403 }
404
405 /*
406 * Given a libmap translation list and a library name, return the
407 * replacement library, or NULL.
408 */
409 char *
lm_findn(const char * p,const char * f,const size_t n)410 lm_findn(const char *p, const char *f, const size_t n)
411 {
412 char pathbuf[64], *s, *t;
413
414 if (n < sizeof(pathbuf) - 1)
415 s = pathbuf;
416 else
417 s = xmalloc(n + 1);
418 memcpy(s, f, n);
419 s[n] = '\0';
420 t = lm_find(p, s);
421 if (s != pathbuf)
422 free(s);
423 return (t);
424 }
425
426 static char *
lml_find(struct lm_list * lmh,const char * f)427 lml_find(struct lm_list *lmh, const char *f)
428 {
429 struct lm *lm;
430
431 dbg("%s(%p, \"%s\")", __func__, lmh, f);
432
433 TAILQ_FOREACH(lm, lmh, lm_link) {
434 if (strcmp(f, lm->f) == 0)
435 return (lm->t);
436 }
437 return (NULL);
438 }
439
440 /*
441 * Given an executable name, return a pointer to the translation list or
442 * NULL if no matches.
443 */
444 static struct lm_list *
lmp_find(const char * n)445 lmp_find(const char *n)
446 {
447 struct lmp *lmp;
448
449 dbg("%s(\"%s\")", __func__, n);
450
451 TAILQ_FOREACH(lmp, &lmp_head, lmp_link) {
452 if ((lmp->type == T_EXACT && strcmp(n, lmp->p) == 0) ||
453 (lmp->type == T_DIRECTORY && strncmp(n, lmp->p,
454 strlen(lmp->p)) == 0) ||
455 (lmp->type == T_BASENAME && strcmp(quickbasename(n),
456 lmp->p) == 0))
457 return (&lmp->lml);
458 }
459 return (NULL);
460 }
461
462 static struct lm_list *
lmp_init(char * n)463 lmp_init(char *n)
464 {
465 struct lmp *lmp;
466
467 dbg("%s(\"%s\")", __func__, n);
468
469 lmp = xmalloc(sizeof(struct lmp));
470 lmp->p = n;
471 if (n[strlen(n) - 1] == '/')
472 lmp->type = T_DIRECTORY;
473 else if (strchr(n,'/') == NULL)
474 lmp->type = T_BASENAME;
475 else
476 lmp->type = T_EXACT;
477 TAILQ_INIT(&lmp->lml);
478 TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link);
479
480 return (&lmp->lml);
481 }
482
483 /*
484 * libc basename is overkill. Return a pointer to the character after
485 * the last /, or the original string if there are no slashes.
486 */
487 static const char *
quickbasename(const char * path)488 quickbasename(const char *path)
489 {
490 const char *p;
491
492 for (p = path; *path != '\0'; path++) {
493 if (*path == '/')
494 p = path + 1;
495 }
496 return (p);
497 }
498