ar.c 8.4 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Mini ar implementation for busybox
  4. *
  5. * Copyright (C) 2000 by Glenn McGrath
  6. *
  7. * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
  8. *
  9. * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10. *
  11. * Archive creation support:
  12. * Copyright (C) 2010 Nokia Corporation. All rights reserved.
  13. * Written by Alexander Shishkin.
  14. *
  15. * There is no single standard to adhere to so ar may not portable
  16. * between different systems
  17. * http://www.unix-systems.org/single_unix_specification_v2/xcu/ar.html
  18. */
  19. //config:config AR
  20. //config: bool "ar (9.5 kb)"
  21. //config: default n # needs to be improved to be able to replace binutils ar
  22. //config: help
  23. //config: ar is an archival utility program used to create, modify, and
  24. //config: extract contents from archives. In practice, it is used exclusively
  25. //config: for object module archives used by compilers.
  26. //config:
  27. //config: Unless you have a specific application which requires ar, you should
  28. //config: probably say N here: most compilers come with their own ar utility.
  29. //config:
  30. //config:config FEATURE_AR_LONG_FILENAMES
  31. //config: bool "Support long filenames (not needed for debs)"
  32. //config: default y
  33. //config: depends on AR
  34. //config: help
  35. //config: By default the ar format can only store the first 15 characters
  36. //config: of the filename, this option removes that limitation.
  37. //config: It supports the GNU ar long filename method which moves multiple long
  38. //config: filenames into a the data section of a new ar entry.
  39. //config:
  40. //config:config FEATURE_AR_CREATE
  41. //config: bool "Support archive creation"
  42. //config: default y
  43. //config: depends on AR
  44. //config: help
  45. //config: This enables archive creation (-c and -r) with busybox ar.
  46. //applet:IF_AR(APPLET(ar, BB_DIR_USR_BIN, BB_SUID_DROP))
  47. //kbuild:lib-$(CONFIG_AR) += ar.o
  48. //usage:#define ar_trivial_usage
  49. //usage: "[-o] [-v] [-p] [-t] [-x] ARCHIVE FILES"
  50. //usage:#define ar_full_usage "\n\n"
  51. //usage: "Extract or list FILES from an ar archive\n"
  52. //usage: "\n -o Preserve original dates"
  53. //usage: "\n -p Extract to stdout"
  54. //usage: "\n -t List"
  55. //usage: "\n -x Extract"
  56. //usage: "\n -v Verbose"
  57. #include "libbb.h"
  58. #include "bb_archive.h"
  59. #include "ar.h"
  60. #if ENABLE_FEATURE_AR_CREATE
  61. /* filter out entries with same names as specified on the command line */
  62. static char FAST_FUNC filter_replaceable(archive_handle_t *handle)
  63. {
  64. if (find_list_entry(handle->accept, handle->file_header->name))
  65. return EXIT_FAILURE;
  66. return EXIT_SUCCESS;
  67. }
  68. static void output_ar_header(archive_handle_t *handle)
  69. {
  70. /* GNU ar 2.19.51.0.14 creates malformed archives
  71. * if input files are >10G. It also truncates files >4GB
  72. * (uses "size mod 4G"). We abort in this case:
  73. * We could add support for up to 10G files, but this is unlikely to be useful.
  74. * Note that unpacking side limits all fields to "unsigned int" data type,
  75. * and treats "all ones" as an error indicator. Thus max we allow here is UINT_MAX-1.
  76. */
  77. enum {
  78. /* for 2nd field: mtime */
  79. MAX11CHARS = UINT_MAX > 0xffffffff ? (unsigned)99999999999 : UINT_MAX-1,
  80. /* for last field: filesize */
  81. MAX10CHARS = UINT_MAX > 0xffffffff ? (unsigned)9999999999 : UINT_MAX-1,
  82. };
  83. struct file_header_t *fh = handle->file_header;
  84. if (handle->offset & 1) {
  85. xwrite(handle->src_fd, "\n", 1);
  86. handle->offset++;
  87. }
  88. /* Careful! The widths should be exact. Fields must be separated */
  89. if (sizeof(off_t) > 4 && fh->size > (off_t)MAX10CHARS) {
  90. bb_error_msg_and_die("'%s' is bigger than ar can handle", fh->name);
  91. }
  92. fdprintf(handle->src_fd, "%-16.16s%-12lu%-6u%-6u%-8o%-10"OFF_FMT"u`\n",
  93. fh->name,
  94. (sizeof(time_t) > 4 && fh->mtime > MAX11CHARS) ? (long)0 : (long)fh->mtime,
  95. fh->uid > 99999 ? 0 : (int)fh->uid,
  96. fh->gid > 99999 ? 0 : (int)fh->gid,
  97. (int)fh->mode & 07777777,
  98. fh->size
  99. );
  100. handle->offset += AR_HEADER_LEN;
  101. }
  102. /*
  103. * when replacing files in an existing archive, copy from the
  104. * original archive those files that are to be left intact
  105. */
  106. static void FAST_FUNC copy_data(archive_handle_t *handle)
  107. {
  108. archive_handle_t *out_handle = handle->ar__out;
  109. struct file_header_t *fh = handle->file_header;
  110. out_handle->file_header = fh;
  111. output_ar_header(out_handle);
  112. bb_copyfd_exact_size(handle->src_fd, out_handle->src_fd, fh->size);
  113. out_handle->offset += fh->size;
  114. }
  115. static int write_ar_header(archive_handle_t *handle)
  116. {
  117. char *fn;
  118. char fn_h[17]; /* 15 + "/" + NUL */
  119. struct stat st;
  120. int fd;
  121. fn = llist_pop(&handle->accept);
  122. if (!fn)
  123. return -1;
  124. xstat(fn, &st);
  125. handle->file_header->mtime = st.st_mtime;
  126. handle->file_header->uid = st.st_uid;
  127. handle->file_header->gid = st.st_gid;
  128. handle->file_header->mode = st.st_mode;
  129. handle->file_header->size = st.st_size;
  130. handle->file_header->name = fn_h;
  131. //TODO: if ENABLE_FEATURE_AR_LONG_FILENAMES...
  132. sprintf(fn_h, "%.15s/", bb_basename(fn));
  133. output_ar_header(handle);
  134. fd = xopen(fn, O_RDONLY);
  135. bb_copyfd_exact_size(fd, handle->src_fd, st.st_size);
  136. close(fd);
  137. handle->offset += st.st_size;
  138. return 0;
  139. }
  140. static int write_ar_archive(archive_handle_t *handle)
  141. {
  142. struct stat st;
  143. archive_handle_t *out_handle;
  144. xfstat(handle->src_fd, &st, handle->ar__name);
  145. /* if archive exists, create a new handle for output.
  146. * we create it in place of the old one.
  147. */
  148. if (st.st_size != 0) {
  149. out_handle = init_handle();
  150. xunlink(handle->ar__name);
  151. out_handle->src_fd = xopen(handle->ar__name, O_WRONLY | O_CREAT | O_TRUNC);
  152. out_handle->accept = handle->accept;
  153. } else {
  154. out_handle = handle;
  155. }
  156. handle->ar__out = out_handle;
  157. xwrite(out_handle->src_fd, AR_MAGIC "\n", AR_MAGIC_LEN + 1);
  158. out_handle->offset += AR_MAGIC_LEN + 1;
  159. /* skip to the end of the archive if we have to append stuff */
  160. if (st.st_size != 0) {
  161. handle->filter = filter_replaceable;
  162. handle->action_data = copy_data;
  163. unpack_ar_archive(handle);
  164. }
  165. while (write_ar_header(out_handle) == 0)
  166. continue;
  167. /* optional, since we exit right after we return */
  168. if (ENABLE_FEATURE_CLEAN_UP) {
  169. close(handle->src_fd);
  170. if (out_handle->src_fd != handle->src_fd)
  171. close(out_handle->src_fd);
  172. }
  173. return EXIT_SUCCESS;
  174. }
  175. #endif /* FEATURE_AR_CREATE */
  176. static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
  177. {
  178. const char *mode = bb_mode_string(file_header->mode);
  179. char *mtime;
  180. mtime = ctime(&file_header->mtime);
  181. mtime[16] = ' ';
  182. memmove(&mtime[17], &mtime[20], 4);
  183. mtime[21] = '\0';
  184. printf("%s %u/%u%7"OFF_FMT"u %s %s\n", &mode[1],
  185. (int)file_header->uid, (int)file_header->gid,
  186. file_header->size,
  187. &mtime[4], file_header->name
  188. );
  189. }
  190. #define AR_OPT_VERBOSE (1 << 0)
  191. #define AR_OPT_PRESERVE_DATE (1 << 1)
  192. /* "ar r" implies create, but warns about it. c suppresses warning.
  193. * bbox accepts but ignores it: */
  194. #define AR_OPT_CREATE (1 << 2)
  195. #define AR_CMD_PRINT (1 << 3)
  196. #define FIRST_CMD AR_CMD_PRINT
  197. #define AR_CMD_LIST (1 << 4)
  198. #define AR_CMD_EXTRACT (1 << 5)
  199. #define AR_CMD_INSERT (1 << 6)
  200. int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  201. int ar_main(int argc UNUSED_PARAM, char **argv)
  202. {
  203. archive_handle_t *archive_handle;
  204. unsigned opt, t;
  205. archive_handle = init_handle();
  206. /* prepend '-' to the first argument if required */
  207. if (argv[1] && argv[1][0] != '-' && argv[1][0] != '\0')
  208. argv[1] = xasprintf("-%s", argv[1]);
  209. opt = getopt32(argv, "^"
  210. "voc""ptx"IF_FEATURE_AR_CREATE("r")
  211. "\0"
  212. /* -1: at least one arg is reqd */
  213. /* one of p,t,x[,r] is required */
  214. "-1:p:t:x"IF_FEATURE_AR_CREATE(":r")
  215. );
  216. argv += optind;
  217. t = opt / FIRST_CMD;
  218. if (t & (t-1)) /* more than one of p,t,x[,r] are specified */
  219. bb_show_usage();
  220. if (opt & AR_CMD_PRINT) {
  221. archive_handle->action_data = data_extract_to_stdout;
  222. }
  223. if (opt & AR_CMD_LIST) {
  224. archive_handle->action_header = header_list;
  225. }
  226. if (opt & AR_CMD_EXTRACT) {
  227. archive_handle->action_data = data_extract_all;
  228. }
  229. if (opt & AR_OPT_PRESERVE_DATE) {
  230. archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
  231. }
  232. if (opt & AR_OPT_VERBOSE) {
  233. archive_handle->action_header = header_verbose_list_ar;
  234. }
  235. #if ENABLE_FEATURE_AR_CREATE
  236. archive_handle->ar__name = *argv;
  237. #endif
  238. archive_handle->src_fd = xopen(*argv++,
  239. (opt & AR_CMD_INSERT)
  240. ? O_RDWR | O_CREAT
  241. : O_RDONLY
  242. );
  243. if (*argv)
  244. archive_handle->filter = filter_accept_list;
  245. while (*argv) {
  246. llist_add_to_end(&archive_handle->accept, *argv++);
  247. }
  248. #if ENABLE_FEATURE_AR_CREATE
  249. if (opt & AR_CMD_INSERT)
  250. return write_ar_archive(archive_handle);
  251. #endif
  252. unpack_ar_archive(archive_handle);
  253. return EXIT_SUCCESS;
  254. }