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 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 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 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 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 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 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 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$"; 365 366 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t); 367 368 if ((lml = lmp_find(p)) == NULL) 369 lml = lmp_init(xstrdup(p)); 370 371 t1 = lml_find(lml, f); 372 if (t1 == NULL || strcmp(t1, t) != 0) { 373 lm = xmalloc(sizeof(struct lm)); 374 lm->f = xstrdup(f); 375 lm->t = xstrdup(t); 376 TAILQ_INSERT_HEAD(lml, lm, lm_link); 377 lm_count++; 378 } 379 } 380 381 char * 382 lm_find(const char *p, const char *f) 383 { 384 struct lm_list *lml; 385 char *t; 386 387 dbg("%s(\"%s\", \"%s\")", __func__, p, f); 388 389 if (p != NULL && (lml = lmp_find(p)) != NULL) { 390 t = lml_find(lml, f); 391 if (t != NULL) { 392 /* 393 * Add a global mapping if we have 394 * a successful constrained match. 395 */ 396 lm_add(NULL, f, t); 397 return (t); 398 } 399 } 400 lml = lmp_find("$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 * 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 * 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 * 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 * 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 * 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