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 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 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 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 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 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 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 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$"; 364 365 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t); 366 367 if ((lml = lmp_find(p)) == NULL) 368 lml = lmp_init(xstrdup(p)); 369 370 t1 = lml_find(lml, f); 371 if (t1 == NULL || strcmp(t1, t) != 0) { 372 lm = xmalloc(sizeof(struct lm)); 373 lm->f = xstrdup(f); 374 lm->t = xstrdup(t); 375 TAILQ_INSERT_HEAD(lml, lm, lm_link); 376 lm_count++; 377 } 378 } 379 380 char * 381 lm_find(const char *p, const char *f) 382 { 383 struct lm_list *lml; 384 char *t; 385 386 dbg("%s(\"%s\", \"%s\")", __func__, p, f); 387 388 if (p != NULL && (lml = lmp_find(p)) != NULL) { 389 t = lml_find(lml, f); 390 if (t != NULL) { 391 /* 392 * Add a global mapping if we have 393 * a successful constrained match. 394 */ 395 lm_add(NULL, f, t); 396 return (t); 397 } 398 } 399 lml = lmp_find("$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 * 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 * 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 * 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 * 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 * 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