ldd.c 19 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * A small little ldd implementation for uClibc
  4. *
  5. * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
  6. *
  7. * Several functions in this file (specifically, elf_find_section_type(),
  8. * elf_find_phdr_type(), and elf_find_dynamic(), were stolen from elflib.c from
  9. * elfvector (http://www.BitWagon.com/elfvector.html) by John F. Reiser
  10. * <jreiser@BitWagon.com>, which is copyright 2000 BitWagon Software LLC
  11. * (GPL2).
  12. *
  13. * Licensed under GPLv2 or later
  14. */
  15. #include "porting.h"
  16. #if defined(__alpha__)
  17. #define MATCH_MACHINE(x) (x == EM_ALPHA)
  18. #define ELFCLASSM ELFCLASS64
  19. #endif
  20. #if defined(__arm__) || defined(__thumb__)
  21. #define MATCH_MACHINE(x) (x == EM_ARM)
  22. #define ELFCLASSM ELFCLASS32
  23. #endif
  24. #if defined(__avr32__)
  25. #define MATCH_MACHINE(x) (x == EM_AVR32)
  26. #define ELFCLASSM ELFCLASS32
  27. #endif
  28. #if defined(__s390__)
  29. #define MATCH_MACHINE(x) (x == EM_S390)
  30. #define ELFCLASSM ELFCLASS32
  31. #endif
  32. #if defined(__hppa__)
  33. #define MATCH_MACHINE(x) (x == EM_PARISC)
  34. #if defined(__LP64__)
  35. #define ELFCLASSM ELFCLASS64
  36. #else
  37. #define ELFCLASSM ELFCLASS32
  38. #endif
  39. #endif
  40. #if defined(__i386__)
  41. #ifndef EM_486
  42. #define MATCH_MACHINE(x) (x == EM_386)
  43. #else
  44. #define MATCH_MACHINE(x) (x == EM_386 || x == EM_486)
  45. #endif
  46. #define ELFCLASSM ELFCLASS32
  47. #endif
  48. #if defined(__ia64__)
  49. #define MATCH_MACHINE(x) (x == EM_IA_64)
  50. #define ELFCLASSM ELFCLASS64
  51. #endif
  52. #if defined(__mc68000__)
  53. #define MATCH_MACHINE(x) (x == EM_68K)
  54. #define ELFCLASSM ELFCLASS32
  55. #endif
  56. #if defined(__mips__)
  57. #define MATCH_MACHINE(x) (x == EM_MIPS || x == EM_MIPS_RS3_LE)
  58. #define ELFCLASSM ELFCLASS32
  59. #endif
  60. #if defined(__powerpc64__)
  61. #define MATCH_MACHINE(x) (x == EM_PPC64)
  62. #define ELFCLASSM ELFCLASS64
  63. #elif defined(__powerpc__)
  64. #define MATCH_MACHINE(x) (x == EM_PPC)
  65. #define ELFCLASSM ELFCLASS32
  66. #endif
  67. #if defined(__sh__)
  68. #define MATCH_MACHINE(x) (x == EM_SH)
  69. #define ELFCLASSM ELFCLASS32
  70. #endif
  71. #if defined(__v850e__)
  72. #define MATCH_MACHINE(x) ((x) == EM_V850 || (x) == EM_CYGNUS_V850)
  73. #define ELFCLASSM ELFCLASS32
  74. #endif
  75. #if defined(__sparc__)
  76. #define MATCH_MACHINE(x) ((x) == EM_SPARC || (x) == EM_SPARC32PLUS)
  77. #define ELFCLASSM ELFCLASS32
  78. #endif
  79. #if defined(__cris__)
  80. #define MATCH_MACHINE(x) (x == EM_CRIS)
  81. #define ELFCLASSM ELFCLASS32
  82. #endif
  83. #if defined(__x86_64__)
  84. #define MATCH_MACHINE(x) (x == EM_X86_64)
  85. #define ELFCLASSM ELFCLASS64
  86. #endif
  87. #ifndef MATCH_MACHINE
  88. # ifdef __linux__
  89. # include <asm/elf.h>
  90. # endif
  91. # ifdef ELF_ARCH
  92. # define MATCH_MACHINE(x) (x == ELF_ARCH)
  93. # endif
  94. # ifdef ELF_CLASS
  95. # define ELFCLASSM ELF_CLASS
  96. # endif
  97. #endif
  98. #ifndef MATCH_MACHINE
  99. # warning "You really should add a MATCH_MACHINE() macro for your architecture"
  100. #endif
  101. #if UCLIBC_ENDIAN_HOST == UCLIBC_ENDIAN_LITTLE
  102. #define ELFDATAM ELFDATA2LSB
  103. #elif UCLIBC_ENDIAN_HOST == UCLIBC_ENDIAN_BIG
  104. #define ELFDATAM ELFDATA2MSB
  105. #endif
  106. struct library {
  107. char *name;
  108. int resolved;
  109. char *path;
  110. struct library *next;
  111. };
  112. static struct library *lib_list = NULL;
  113. static char not_found[] = "not found";
  114. static char *interp_name = NULL;
  115. static char *interp_dir = NULL;
  116. static int byteswap;
  117. static int interpreter_already_found = 0;
  118. static __inline__ uint32_t byteswap32_to_host(uint32_t value)
  119. {
  120. if (byteswap == 1) {
  121. return (bswap_32(value));
  122. } else {
  123. return (value);
  124. }
  125. }
  126. static __inline__ uint64_t byteswap64_to_host(uint64_t value)
  127. {
  128. if (byteswap == 1) {
  129. return (bswap_64(value));
  130. } else {
  131. return (value);
  132. }
  133. }
  134. #if ELFCLASSM == ELFCLASS32
  135. # define byteswap_to_host(x) byteswap32_to_host(x)
  136. #else
  137. # define byteswap_to_host(x) byteswap64_to_host(x)
  138. #endif
  139. static ElfW(Shdr) *elf_find_section_type(uint32_t key, ElfW(Ehdr) *ehdr)
  140. {
  141. int j;
  142. ElfW(Shdr) *shdr;
  143. shdr = (ElfW(Shdr) *) (ehdr->e_shoff + (char *)ehdr);
  144. for (j = ehdr->e_shnum; --j >= 0; ++shdr) {
  145. if (key == byteswap32_to_host(shdr->sh_type)) {
  146. return shdr;
  147. }
  148. }
  149. return NULL;
  150. }
  151. static ElfW(Phdr) *elf_find_phdr_type(uint32_t type, ElfW(Ehdr) *ehdr)
  152. {
  153. int j;
  154. ElfW(Phdr) *phdr = (ElfW(Phdr) *) (ehdr->e_phoff + (char *)ehdr);
  155. for (j = ehdr->e_phnum; --j >= 0; ++phdr) {
  156. if (type == byteswap32_to_host(phdr->p_type)) {
  157. return phdr;
  158. }
  159. }
  160. return NULL;
  161. }
  162. /* Returns value if return_val==1, ptr otherwise */
  163. static void *elf_find_dynamic(int64_t const key, ElfW(Dyn) *dynp,
  164. ElfW(Ehdr) *ehdr, int return_val)
  165. {
  166. ElfW(Phdr) *pt_text = elf_find_phdr_type(PT_LOAD, ehdr);
  167. unsigned tx_reloc = byteswap_to_host(pt_text->p_vaddr) - byteswap_to_host(pt_text->p_offset);
  168. for (; DT_NULL != byteswap_to_host(dynp->d_tag); ++dynp) {
  169. if (key == byteswap_to_host(dynp->d_tag)) {
  170. if (return_val == 1)
  171. return (void *)byteswap_to_host(dynp->d_un.d_val);
  172. else
  173. return (void *)(byteswap_to_host(dynp->d_un.d_val) - tx_reloc + (char *)ehdr);
  174. }
  175. }
  176. return NULL;
  177. }
  178. static char *elf_find_rpath(ElfW(Ehdr) *ehdr, ElfW(Dyn) *dynamic)
  179. {
  180. ElfW(Dyn) *dyns;
  181. for (dyns = dynamic; byteswap_to_host(dyns->d_tag) != DT_NULL; ++dyns) {
  182. if (DT_RPATH == byteswap_to_host(dyns->d_tag)) {
  183. char *strtab;
  184. strtab = (char *)elf_find_dynamic(DT_STRTAB, dynamic, ehdr, 0);
  185. return ((char *)strtab + byteswap_to_host(dyns->d_un.d_val));
  186. }
  187. }
  188. return NULL;
  189. }
  190. static int check_elf_header(ElfW(Ehdr) *const ehdr)
  191. {
  192. if (!ehdr || *(uint32_t*)ehdr != ELFMAG_U32
  193. || ehdr->e_ident[EI_CLASS] != ELFCLASSM
  194. || ehdr->e_ident[EI_VERSION] != EV_CURRENT
  195. ) {
  196. return 1;
  197. }
  198. /* Check if the target endianness matches the host's endianness */
  199. byteswap = 0;
  200. if (UCLIBC_ENDIAN_HOST == UCLIBC_ENDIAN_LITTLE) {
  201. if (ehdr->e_ident[5] == ELFDATA2MSB)
  202. byteswap = 1;
  203. } else if (UCLIBC_ENDIAN_HOST == UCLIBC_ENDIAN_BIG) {
  204. if (ehdr->e_ident[5] == ELFDATA2LSB)
  205. byteswap = 1;
  206. }
  207. /* Be very lazy, and only byteswap the stuff we use */
  208. if (byteswap) {
  209. ehdr->e_type = bswap_16(ehdr->e_type);
  210. ehdr->e_phoff = byteswap_to_host(ehdr->e_phoff);
  211. ehdr->e_shoff = byteswap_to_host(ehdr->e_shoff);
  212. ehdr->e_phnum = bswap_16(ehdr->e_phnum);
  213. ehdr->e_shnum = bswap_16(ehdr->e_shnum);
  214. }
  215. return 0;
  216. }
  217. #ifdef __LDSO_CACHE_SUPPORT__
  218. static caddr_t cache_addr = NULL;
  219. static size_t cache_size = 0;
  220. static int map_cache(void)
  221. {
  222. int fd;
  223. struct stat st;
  224. header_t *header;
  225. libentry_t *libent;
  226. int i, strtabsize;
  227. if (cache_addr == (caddr_t) - 1)
  228. return -1;
  229. else if (cache_addr != NULL)
  230. return 0;
  231. if (stat(LDSO_CACHE, &st) || (fd = open(LDSO_CACHE, O_RDONLY)) < 0) {
  232. fprintf(stderr, "ldd: can't open cache '%s'\n", LDSO_CACHE);
  233. cache_addr = (caddr_t) - 1; /* so we won't try again */
  234. return -1;
  235. }
  236. cache_size = st.st_size;
  237. cache_addr = mmap(0, cache_size, PROT_READ, MAP_SHARED, fd, 0);
  238. close(fd);
  239. if (cache_addr == MAP_FAILED) {
  240. fprintf(stderr, "ldd: can't map cache '%s'\n", LDSO_CACHE);
  241. return -1;
  242. }
  243. header = (header_t *) cache_addr;
  244. if (cache_size < sizeof(header_t)
  245. || memcmp(header->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN)
  246. || memcmp(header->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN)
  247. || cache_size < (sizeof(header_t) + header->nlibs * sizeof(libentry_t))
  248. || cache_addr[cache_size - 1] != '\0')
  249. {
  250. fprintf(stderr, "ldd: cache '%s' is corrupt\n", LDSO_CACHE);
  251. goto fail;
  252. }
  253. strtabsize = cache_size - sizeof(header_t) - header->nlibs * sizeof(libentry_t);
  254. libent = (libentry_t *) & header[1];
  255. for (i = 0; i < header->nlibs; i++) {
  256. if (libent[i].sooffset >= strtabsize || libent[i].liboffset >= strtabsize) {
  257. fprintf(stderr, "ldd: cache '%s' is corrupt\n", LDSO_CACHE);
  258. goto fail;
  259. }
  260. }
  261. return 0;
  262. fail:
  263. munmap(cache_addr, cache_size);
  264. cache_addr = (caddr_t) - 1;
  265. return -1;
  266. }
  267. static int unmap_cache(void)
  268. {
  269. if (cache_addr == NULL || cache_addr == (caddr_t) - 1)
  270. return -1;
  271. #if 1
  272. munmap(cache_addr, cache_size);
  273. cache_addr = NULL;
  274. #endif
  275. return 0;
  276. }
  277. #else
  278. static __inline__ void map_cache(void)
  279. {
  280. }
  281. static __inline__ void unmap_cache(void)
  282. {
  283. }
  284. #endif
  285. /* This function's behavior must exactly match that
  286. * in uClibc/ldso/ldso/dl-elf.c */
  287. static void search_for_named_library(char *name, char *result,
  288. const char *path_list)
  289. {
  290. int i, count = 1;
  291. char *path, *path_n;
  292. struct stat filestat;
  293. /* We need a writable copy of this string */
  294. path = strdup(path_list);
  295. if (!path) {
  296. fprintf(stderr, "%s: Out of memory!\n", __func__);
  297. exit(EXIT_FAILURE);
  298. }
  299. /* Eliminate all double //s */
  300. path_n = path;
  301. while ((path_n = strstr(path_n, "//"))) {
  302. i = strlen(path_n);
  303. memmove(path_n, path_n + 1, i - 1);
  304. *(path_n + i - 1) = '\0';
  305. }
  306. /* Replace colons with zeros in path_list and count them */
  307. for (i = strlen(path); i > 0; i--) {
  308. if (path[i] == ':') {
  309. path[i] = 0;
  310. count++;
  311. }
  312. }
  313. path_n = path;
  314. for (i = 0; i < count; i++) {
  315. strcpy(result, path_n);
  316. strcat(result, "/");
  317. strcat(result, name);
  318. if (stat(result, &filestat) == 0 && filestat.st_mode & S_IRUSR) {
  319. free(path);
  320. return;
  321. }
  322. path_n += (strlen(path_n) + 1);
  323. }
  324. free(path);
  325. *result = '\0';
  326. }
  327. static void locate_library_file(ElfW(Ehdr) *ehdr, ElfW(Dyn) *dynamic,
  328. int is_suid, struct library *lib)
  329. {
  330. char *buf;
  331. char *path;
  332. struct stat filestat;
  333. /* If this is a fully resolved name, our job is easy */
  334. if (stat(lib->name, &filestat) == 0) {
  335. lib->path = strdup(lib->name);
  336. return;
  337. }
  338. /* We need some elbow room here. Make some room... */
  339. buf = malloc(1024);
  340. if (!buf) {
  341. fprintf(stderr, "%s: Out of memory!\n", __func__);
  342. exit(EXIT_FAILURE);
  343. }
  344. /* This function must match the behavior of _dl_load_shared_library
  345. * in readelflib1.c or things won't work out as expected... */
  346. /* The ABI specifies that RPATH is searched first, so do that now. */
  347. path = elf_find_rpath(ehdr, dynamic);
  348. if (path) {
  349. search_for_named_library(lib->name, buf, path);
  350. if (*buf != '\0') {
  351. lib->path = buf;
  352. return;
  353. }
  354. }
  355. /* Next check LD_{ELF_}LIBRARY_PATH if specified and allowed.
  356. * Since this app doesn't actually run an executable I will skip
  357. * the suid check, and just use LD_{ELF_}LIBRARY_PATH if set */
  358. if (is_suid == 1)
  359. path = NULL;
  360. else
  361. path = getenv("LD_LIBRARY_PATH");
  362. if (path) {
  363. search_for_named_library(lib->name, buf, path);
  364. if (*buf != '\0') {
  365. lib->path = buf;
  366. return;
  367. }
  368. }
  369. #ifdef __LDSO_CACHE_SUPPORT__
  370. if (cache_addr != NULL && cache_addr != (caddr_t) - 1) {
  371. int i;
  372. header_t *header = (header_t *) cache_addr;
  373. libentry_t *libent = (libentry_t *) & header[1];
  374. char *strs = (char *)&libent[header->nlibs];
  375. for (i = 0; i < header->nlibs; i++) {
  376. if ((libent[i].flags == LIB_ELF ||
  377. libent[i].flags == LIB_ELF_LIBC0 ||
  378. libent[i].flags == LIB_ELF_LIBC5) &&
  379. strcmp(lib->name, strs + libent[i].sooffset) == 0)
  380. {
  381. lib->path = strdup(strs + libent[i].liboffset);
  382. return;
  383. }
  384. }
  385. }
  386. #endif
  387. /* Next look for libraries wherever the shared library
  388. * loader was installed -- this is usually where we
  389. * should find things... */
  390. if (interp_dir) {
  391. search_for_named_library(lib->name, buf, interp_dir);
  392. if (*buf != '\0') {
  393. lib->path = buf;
  394. return;
  395. }
  396. }
  397. /* Lastly, search the standard list of paths for the library.
  398. This list must exactly match the list in uClibc/ldso/ldso/dl-elf.c */
  399. path = UCLIBC_RUNTIME_PREFIX "lib:" UCLIBC_RUNTIME_PREFIX "usr/lib"
  400. #ifndef __LDSO_CACHE_SUPPORT__
  401. ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
  402. #endif
  403. ;
  404. search_for_named_library(lib->name, buf, path);
  405. if (*buf != '\0') {
  406. lib->path = buf;
  407. } else {
  408. free(buf);
  409. lib->path = not_found;
  410. }
  411. }
  412. static int add_library(ElfW(Ehdr) *ehdr, ElfW(Dyn) *dynamic, int is_setuid, char *s)
  413. {
  414. char *tmp, *tmp1, *tmp2;
  415. struct library *cur, *newlib = lib_list;
  416. if (!s || !strlen(s))
  417. return 1;
  418. tmp = s;
  419. while (*tmp) {
  420. if (*tmp == '/')
  421. s = tmp + 1;
  422. tmp++;
  423. }
  424. /* We add ldso elsewhere */
  425. if (interpreter_already_found && (tmp = strrchr(interp_name, '/')) != NULL) {
  426. int len = strlen(interp_dir);
  427. if (strcmp(s, interp_name + 1 + len) == 0)
  428. return 1;
  429. }
  430. for (cur = lib_list; cur; cur = cur->next) {
  431. /* Check if this library is already in the list */
  432. tmp1 = tmp2 = cur->name;
  433. while (*tmp1) {
  434. if (*tmp1 == '/')
  435. tmp2 = tmp1 + 1;
  436. tmp1++;
  437. }
  438. if (strcmp(tmp2, s) == 0) {
  439. /*printf("find_elf_interpreter is skipping '%s' (already in list)\n", cur->name); */
  440. return 0;
  441. }
  442. }
  443. /* Ok, this lib needs to be added to the list */
  444. newlib = malloc(sizeof(struct library));
  445. if (!newlib)
  446. return 1;
  447. newlib->name = malloc(strlen(s) + 1);
  448. strcpy(newlib->name, s);
  449. newlib->resolved = 0;
  450. newlib->path = NULL;
  451. newlib->next = NULL;
  452. /* Now try and locate where this library might be living... */
  453. locate_library_file(ehdr, dynamic, is_setuid, newlib);
  454. /*printf("add_library is adding '%s' to '%s'\n", newlib->name, newlib->path); */
  455. if (!lib_list) {
  456. lib_list = newlib;
  457. } else {
  458. for (cur = lib_list; cur->next; cur = cur->next) ; /* nothing */
  459. cur->next = newlib;
  460. }
  461. return 0;
  462. }
  463. static void find_needed_libraries(ElfW(Ehdr) *ehdr, ElfW(Dyn) *dynamic, int is_setuid)
  464. {
  465. ElfW(Dyn) *dyns;
  466. for (dyns = dynamic; byteswap_to_host(dyns->d_tag) != DT_NULL; ++dyns) {
  467. if (DT_NEEDED == byteswap_to_host(dyns->d_tag)) {
  468. char *strtab;
  469. strtab = (char *)elf_find_dynamic(DT_STRTAB, dynamic, ehdr, 0);
  470. add_library(ehdr, dynamic, is_setuid, (char *)strtab + byteswap_to_host(dyns->d_un.d_val));
  471. }
  472. }
  473. }
  474. static struct library *find_elf_interpreter(ElfW(Ehdr) *ehdr)
  475. {
  476. ElfW(Phdr) *phdr;
  477. if (interpreter_already_found == 1)
  478. return NULL;
  479. phdr = elf_find_phdr_type(PT_INTERP, ehdr);
  480. if (phdr) {
  481. struct library *cur, *newlib = NULL;
  482. char *s = (char *)ehdr + byteswap_to_host(phdr->p_offset);
  483. char *tmp, *tmp1;
  484. interp_name = strdup(s);
  485. interp_dir = strdup(s);
  486. tmp = strrchr(interp_dir, '/');
  487. if (tmp)
  488. *tmp = '\0';
  489. else {
  490. free(interp_dir);
  491. interp_dir = interp_name;
  492. }
  493. tmp1 = tmp = s;
  494. while (*tmp) {
  495. if (*tmp == '/')
  496. tmp1 = tmp + 1;
  497. tmp++;
  498. }
  499. for (cur = lib_list; cur; cur = cur->next) {
  500. /* Check if this library is already in the list */
  501. if (strcmp(cur->name, tmp1) == 0) {
  502. /*printf("find_elf_interpreter is replacing '%s' (already in list)\n", cur->name); */
  503. newlib = cur;
  504. free(newlib->name);
  505. if (newlib->path != not_found) {
  506. free(newlib->path);
  507. }
  508. newlib->name = NULL;
  509. newlib->path = NULL;
  510. break;
  511. }
  512. }
  513. if (newlib == NULL)
  514. newlib = malloc(sizeof(struct library));
  515. if (!newlib)
  516. return NULL;
  517. newlib->name = malloc(strlen(s) + 1);
  518. strcpy(newlib->name, s);
  519. newlib->path = strdup(newlib->name);
  520. newlib->resolved = 1;
  521. newlib->next = NULL;
  522. #if 0
  523. /*printf("find_elf_interpreter is adding '%s' to '%s'\n", newlib->name, newlib->path); */
  524. if (!lib_list) {
  525. lib_list = newlib;
  526. } else {
  527. for (cur = lib_list; cur->next; cur = cur->next) ; /* nothing */
  528. cur->next = newlib;
  529. }
  530. #endif
  531. interpreter_already_found = 1;
  532. return newlib;
  533. }
  534. return NULL;
  535. }
  536. /* map the .so, and locate interesting pieces */
  537. /*
  538. #warning "There may be two warnings here about vfork() clobbering, ignore them"
  539. */
  540. static int find_dependencies(char *filename)
  541. {
  542. int is_suid = 0;
  543. FILE *thefile;
  544. struct library *interp;
  545. struct stat statbuf;
  546. ElfW(Ehdr) *ehdr = NULL;
  547. ElfW(Shdr) *dynsec = NULL;
  548. ElfW(Dyn) *dynamic = NULL;
  549. if (filename == not_found)
  550. return 0;
  551. if (!filename) {
  552. fprintf(stderr, "No filename specified.\n");
  553. return -1;
  554. }
  555. if (!(thefile = fopen(filename, "r"))) {
  556. perror(filename);
  557. return -1;
  558. }
  559. if (fstat(fileno(thefile), &statbuf) < 0) {
  560. perror(filename);
  561. fclose(thefile);
  562. return -1;
  563. }
  564. if ((size_t) statbuf.st_size < sizeof(ElfW(Ehdr)))
  565. goto foo;
  566. if (!S_ISREG(statbuf.st_mode))
  567. goto foo;
  568. /* mmap the file to make reading stuff from it effortless */
  569. ehdr = mmap(0, statbuf.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fileno(thefile), 0);
  570. if (ehdr == MAP_FAILED) {
  571. fclose(thefile);
  572. fprintf(stderr, "mmap(%s) failed: %s\n", filename, strerror(errno));
  573. return -1;
  574. }
  575. foo:
  576. fclose(thefile);
  577. /* Check if this looks like a legit ELF file */
  578. if (check_elf_header(ehdr)) {
  579. fprintf(stderr, "%s: not an ELF file.\n", filename);
  580. return -1;
  581. }
  582. /* Check if this is the right kind of ELF file */
  583. if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
  584. fprintf(stderr, "%s: not a dynamic executable\n", filename);
  585. return -1;
  586. }
  587. if (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN) {
  588. if (statbuf.st_mode & S_ISUID)
  589. is_suid = 1;
  590. if ((statbuf.st_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
  591. is_suid = 1;
  592. /* FIXME */
  593. if (is_suid)
  594. fprintf(stderr, "%s: is setuid\n", filename);
  595. }
  596. interpreter_already_found = 0;
  597. interp = find_elf_interpreter(ehdr);
  598. #ifdef __LDSO_LDD_SUPPORT__
  599. if (interp
  600. && (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN)
  601. && ehdr->e_ident[EI_CLASS] == ELFCLASSM
  602. && ehdr->e_ident[EI_DATA] == ELFDATAM
  603. && ehdr->e_ident[EI_VERSION] == EV_CURRENT
  604. && MATCH_MACHINE(ehdr->e_machine))
  605. {
  606. struct stat st;
  607. if (stat(interp->path, &st) == 0 && S_ISREG(st.st_mode)) {
  608. pid_t pid;
  609. int status;
  610. static const char *const environment[] = {
  611. "PATH=/usr/bin:/bin:/usr/sbin:/sbin",
  612. "SHELL=/bin/sh",
  613. "LD_TRACE_LOADED_OBJECTS=1",
  614. NULL
  615. };
  616. if ((pid = vfork()) == 0) {
  617. /* Cool, it looks like we should be able to actually
  618. * run this puppy. Do so now... */
  619. execle(filename, filename, NULL, environment);
  620. _exit(0xdead);
  621. }
  622. /* Wait till it returns */
  623. waitpid(pid, &status, 0);
  624. if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
  625. return 1;
  626. }
  627. /* If the exec failed, we fall through to trying to find
  628. * all the needed libraries ourselves by rummaging about
  629. * in the ELF headers... */
  630. }
  631. }
  632. #endif
  633. dynsec = elf_find_section_type(SHT_DYNAMIC, ehdr);
  634. if (dynsec) {
  635. dynamic = (ElfW(Dyn) *) (byteswap_to_host(dynsec->sh_offset) + (char *)ehdr);
  636. find_needed_libraries(ehdr, dynamic, is_suid);
  637. }
  638. return 0;
  639. }
  640. int main(int argc, char **argv)
  641. {
  642. int multi = 0;
  643. int got_em_all = 1;
  644. char *filename = NULL;
  645. struct library *cur;
  646. if (argc < 2) {
  647. fprintf(stderr, "ldd: missing file arguments\n"
  648. "Try `ldd --help' for more information.\n");
  649. exit(EXIT_FAILURE);
  650. }
  651. if (argc > 2)
  652. multi++;
  653. while (--argc > 0) {
  654. ++argv;
  655. if (strcmp(*argv, "--") == 0) {
  656. /* Ignore "--" */
  657. continue;
  658. }
  659. if (strcmp(*argv, "--help") == 0 || strcmp(*argv, "-h") == 0) {
  660. fprintf(stderr, "Usage: ldd [OPTION]... FILE...\n"
  661. "\t--help\t\tprint this help and exit\n");
  662. exit(EXIT_SUCCESS);
  663. }
  664. filename = *argv;
  665. if (!filename) {
  666. fprintf(stderr, "No filename specified.\n");
  667. exit(EXIT_FAILURE);
  668. }
  669. if (multi) {
  670. printf("%s:\n", *argv);
  671. }
  672. map_cache();
  673. if (find_dependencies(filename) != 0)
  674. continue;
  675. while (got_em_all) {
  676. got_em_all = 0;
  677. /* Keep walking the list till everybody is resolved */
  678. for (cur = lib_list; cur; cur = cur->next) {
  679. if (cur->resolved == 0 && cur->path) {
  680. got_em_all = 1;
  681. printf("checking sub-depends for '%s'\n", cur->path);
  682. find_dependencies(cur->path);
  683. cur->resolved = 1;
  684. }
  685. }
  686. }
  687. unmap_cache();
  688. /* Print the list */
  689. got_em_all = 0;
  690. for (cur = lib_list; cur; cur = cur->next) {
  691. got_em_all = 1;
  692. printf("\t%s => %s (0x00000000)\n", cur->name, cur->path);
  693. }
  694. if (interp_name && interpreter_already_found == 1)
  695. printf("\t%s => %s (0x00000000)\n", interp_name, interp_name);
  696. else
  697. printf("\tnot a dynamic executable\n");
  698. for (cur = lib_list; cur; cur = cur->next) {
  699. free(cur->name);
  700. cur->name = NULL;
  701. if (cur->path && cur->path != not_found) {
  702. free(cur->path);
  703. cur->path = NULL;
  704. }
  705. }
  706. lib_list = NULL;
  707. }
  708. return 0;
  709. }