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