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utils-std

Collection of commonly available Unix tools git clone https://anongit.hacktivis.me/git/utils-std.git/

chown.c (7110B)

    

  1. // utils-std: Collection of commonly available Unix tools
  2. // SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: MPL-2.0
  5. #define _POSIX_C_SOURCE 200809L
  7. // NetBSD <10 hides fdopendir behind _NETBSD_SOURCE
  8. #if __NetBSD_Version__ < 1000000000
  9. #define _NETBSD_SOURCE
  10. #endif
  12. #include "../config.h" // HAS_*
  13. #include "../lib/fs.h"
  14. #include "../lib/getopt_nolong.h"
  15. #include "../lib/user_group_parse.h"
  17. #include <dirent.h> // fdopendir, readdir, closedir
  18. #include <errno.h>
  19. #include <fcntl.h>  // AT_FDCWD, fchownat
  20. #include <limits.h> // PATH_MAX
  21. #include <stdbool.h>
  22. #include <stdio.h>    // fprintf
  23. #include <stdlib.h>   // abort, exit
  24. #include <string.h>   // strerror, strcmp
  25. #include <sys/stat.h> // fstatat, S_ISDIR
  26. #include <unistd.h>   // getopt
  27. #ifdef HAS_GETOPT_LONG
  28. #include <getopt.h>
  29. #endif
  31. const char *argv0 = NULL;
  33. static uid_t user = (uid_t)-1;
  34. static uid_t group = (uid_t)-1;
  36. static bool opt_v = false, opt_R = false;
  38. enum chown_follow_symlinks
  39. {
  40. 	CHOWN_FOLLOW_UNK_SYMLINKS,
  41. 	CHOWN_FOLLOW_ALL_SYMLINKS,
  42. 	CHOWN_FOLLOW_NO_SYMLINK,
  43. 	CHOWN_FOLLOW_ONE_SYMLINK,
  44. };
  46. static int
  47. do_fchownat(int fd, char *name, char *acc_path, enum chown_follow_symlinks follow_symlinks)
  48. {
  49. 	struct stat stats;
  50. 	int err = 0;
  52. 	int stat_opts = (follow_symlinks == CHOWN_FOLLOW_NO_SYMLINK) ? AT_SYMLINK_NOFOLLOW : 0;
  53. 	int chown_opts = (follow_symlinks == CHOWN_FOLLOW_NO_SYMLINK) ? AT_SYMLINK_NOFOLLOW : 0;
  55. 	if(fstatat(fd, name, &stats, stat_opts) != 0)
  56. 	{
  57. 		fprintf(stderr,
  58. 		        "%s: error: Failed getting status for '%s': %s\n",
  59. 		        argv0,
  60. 		        acc_path,
  61. 		        strerror(errno));
  62. 		errno = 0;
  63. 		return 1;
  64. 	}
  66. 	bool change = false;
  67. 	if(user != (uid_t)-1 && stats.st_uid != user) change = true;
  68. 	if(group != (uid_t)-1 && stats.st_gid != group) change = true;
  70. 	if(change)
  71. 	{
  72. 		if(fchownat(fd, name, user, group, chown_opts) != 0)
  73. 		{
  74. 			fprintf(stderr,
  75. 			        "%s: error: Failed setting ownership to '%d:%d' for '%s': %s\n",
  76. 			        argv0,
  77. 			        user,
  78. 			        group,
  79. 			        acc_path,
  80. 			        strerror(errno));
  81. 			errno = 0;
  82. 			return 1;
  83. 		}
  85. 		if(opt_v)
  86. 			printf("%s: Ownership changed from %d:%d to %d:%d for '%s'\n",
  87. 			       argv0,
  88. 			       stats.st_uid,
  89. 			       stats.st_gid,
  90. 			       user,
  91. 			       group,
  92. 			       acc_path);
  93. 	}
  94. 	else
  95. 	{
  96. 		if(opt_v)
  97. 			printf("%s: Ownership already set to %d:%d for '%s'\n",
  98. 			       argv0,
  99. 			       stats.st_uid,
  100. 			       stats.st_gid,
  101. 			       acc_path);
  102. 	}
  104. 	if(opt_R && S_ISDIR(stats.st_mode))
  105. 	{
  106. 		int dir = openat(fd, name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
  107. 		if(dir == -1)
  108. 		{
  109. 			fprintf(stderr,
  110. 			        "%s: error: Couldn't open '%s' as directory: %s\n",
  111. 			        argv0,
  112. 			        acc_path,
  113. 			        strerror(errno));
  114. 			errno = 0;
  115. 			return 1;
  116. 		}
  118. 		DIR *dirp = fdopendir(dir);
  119. 		if(dirp == NULL)
  120. 		{
  121. 			fprintf(stderr,
  122. 			        "%s: error: Couldn't get DIR entry for opened '%s': %s\n",
  123. 			        argv0,
  124. 			        acc_path,
  125. 			        strerror(errno));
  126. 			errno = 0;
  127. 			return 1;
  128. 		}
  130. 		while(true)
  131. 		{
  132. 			struct dirent *dp = readdir(dirp);
  133. 			if(dp == NULL)
  134. 			{
  135. 				if(errno == 0) break;
  137. 				fprintf(stderr,
  138. 				        "%s: error: Failed reading directory '%s': %s\n",
  139. 				        argv0,
  140. 				        acc_path,
  141. 				        strerror(errno));
  142. 				closedir(dirp); // FIXME: unhandled error
  143. 				errno = 0;
  144. 				return 1;
  145. 			}
  147. 			if(strcmp(dp->d_name, ".") == 0) continue;
  148. 			if(strcmp(dp->d_name, "..") == 0) continue;
  150. 			char new_path[PATH_MAX] = "";
  151. 			if(snprintf(new_path, PATH_MAX, "%s/%s", acc_path, dp->d_name) < 0)
  152. 			{
  153. 				fprintf(stderr,
  154. 				        "%s: error: Couldn't concatenate '%s' into parent '%s', skipping to next entry: %s",
  155. 				        argv0,
  156. 				        name,
  157. 				        acc_path,
  158. 				        strerror(errno));
  159. 				err++;
  160. 				errno = 0;
  161. 				continue;
  162. 			}
  164. 			enum chown_follow_symlinks child_follow_symlinks =
  165. 			    (follow_symlinks == CHOWN_FOLLOW_ONE_SYMLINK) ? CHOWN_FOLLOW_NO_SYMLINK : follow_symlinks;
  167. 			// No depth counter for now, unlikely to be a problem as symlinks aren't followed
  168. 			int ret = do_fchownat(dir, dp->d_name, new_path, child_follow_symlinks);
  169. 			if(ret != 0) return ret;
  170. 		}
  172. 		// fdopendir allocates memory for DIR, needs closedir
  173. 		if(closedir(dirp) != 0)
  174. 		{
  175. 			fprintf(stderr,
  176. 			        "%s: error: Deallocating directory entry for '%s' failed: %s\n",
  177. 			        argv0,
  178. 			        acc_path,
  179. 			        strerror(errno));
  180. 			errno = 0;
  181. 			return 1;
  182. 		}
  183. 	}
  185. 	return err;
  186. }
  188. static void
  189. usage(void)
  190. {
  191. 	if(strcmp(argv0, "chown") == 0)
  192. 		fprintf(stderr, "Usage: %s [-h | -R [-H|-L|-P]] owner[:group] file...\n", argv0);
  193. 	else if(strcmp(argv0, "chgrp") == 0)
  194. 		fprintf(stderr, "Usage: %s [-h | -R [-H|-L|-P]] group file...\n", argv0);
  195. 	else
  196. 	{
  197. 		fprintf(
  198. 		    stderr, "%s: error: Unknown utility '%s' expected either chown or chgrp\n", argv0, argv0);
  199. 		exit(1);
  200. 	}
  201. }
  203. int
  204. main(int argc, char *argv[])
  205. {
  206. 	argv0 = static_basename(argv[0]);
  208. 	enum chown_follow_symlinks follow_symlinks = CHOWN_FOLLOW_UNK_SYMLINKS;
  210. #ifdef HAS_GETOPT_LONG
  211. 	// Strictly for GNUisms compatibility so no long-only options
  212. 	// clang-format off
  213. 	static struct option opts[] = {
  214. 		{"no-dereference", no_argument, 0, 'h'},
  215. 		{"recursive", no_argument, 0, 'R'},
  216. 		{"verbose", no_argument, 0, 'v'},
  217. 		{0, 0, 0, 0},
  218. 	};
  219. 	// clang-format on
  221. 	// Need + as first character to get POSIX-style option parsing
  222. 	for(int c = -1; (c = getopt_long(argc, argv, "+:hRHLPv", opts, NULL)) != -1;)
  223. #else
  224. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":hRHLPv")) != -1;)
  225. #endif
  226. 	{
  227. 		switch(c)
  228. 		{
  229. 		case 'h':
  230. 			follow_symlinks = CHOWN_FOLLOW_NO_SYMLINK;
  231. 			break;
  232. 		case 'R':
  233. 			opt_R = true;
  234. 			break;
  235. 		case 'H':
  236. 			follow_symlinks = CHOWN_FOLLOW_ONE_SYMLINK;
  237. 			break;
  238. 		case 'L':
  239. 			follow_symlinks = CHOWN_FOLLOW_ALL_SYMLINKS;
  240. 			break;
  241. 		case 'P':
  242. 			follow_symlinks = CHOWN_FOLLOW_NO_SYMLINK;
  243. 			break;
  244. 		case 'v':
  245. 			opt_v = true;
  246. 			break;
  247. 		case ':':
  248. 			fprintf(stderr, "%s: error: Missing operand for option: '-%c'\n", argv0, optopt);
  249. 			usage();
  250. 			return 1;
  251. 		case '?':
  252. 			if(!got_long_opt) fprintf(stderr, "%s: error: Unrecognised option: '-%c'\n", argv0, optopt);
  253. 			usage();
  254. 			return 1;
  255. 		default:
  256. 			abort();
  257. 		}
  258. 	}
  260. 	argc -= optind;
  261. 	argv += optind;
  263. 	if(follow_symlinks == CHOWN_FOLLOW_UNK_SYMLINKS)
  264. 		follow_symlinks = opt_R ? CHOWN_FOLLOW_NO_SYMLINK : CHOWN_FOLLOW_ALL_SYMLINKS;
  266. 	if(argc < 2)
  267. 	{
  268. 		fprintf(stderr, "%s: error: Expects >=2 arguments, %d given\n", argv0, argc);
  269. 		usage();
  270. 		return 1;
  271. 	}
  273. 	if(strcmp(argv0, "chown") == 0)
  274. 	{
  275. 		char *gname = strchr(argv[0], ':');
  276. 		if(gname != NULL)
  277. 		{
  278. 			gname[0] = 0;
  279. 			gname++;
  281. 			if(parse_group(gname, &group) < 0) return 1;
  282. 		}
  283. 		if(parse_user(argv[0], &user) < 0) return 1;
  284. 	}
  285. 	else if(strcmp(argv0, "chgrp") == 0)
  286. 	{
  287. 		if(parse_group(argv[0], &group) < 0) return 1;
  288. 	}
  289. 	else
  290. 	{
  291. 		fprintf(
  292. 		    stderr, "%s: error: Unknown utility '%s' expected either chown or chgrp\n", argv0, argv0);
  293. 		return 1;
  294. 	}
  296. 	for(int i = 1; i < argc; i++)
  297. 	{
  298. 		int ret = do_fchownat(AT_FDCWD, argv[i], argv[i], follow_symlinks);
  299. 		if(ret != 0) return ret;
  300. 	}
  302. 	return 0;
  303. }