Changeset 1770 in MondoRescue for branches/stable/mindi-busybox/libbb/copy_file.c
- Timestamp:
- Nov 6, 2007, 11:01:53 AM (16 years ago)
- File:
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- 1 edited
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branches/stable/mindi-busybox/libbb/copy_file.c
r821 r1770 4 4 * 5 5 * Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu> 6 * SELinux support by Yuichi Nakamura <ynakam@hitachisoft.jp> 6 7 * 7 8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. … … 10 11 11 12 #include "libbb.h" 12 #include <utime.h> 13 #include <errno.h> 14 13 14 // POSIX: if exists and -i, ask (w/o -i assume yes). 15 // Then open w/o EXCL (yes, not unlink!). 16 // If open still fails and -f, try unlink, then try open again. 17 // Result: a mess: 18 // If dest is a softlink, we overwrite softlink's destination! 19 // (or fail, if it points to dir/nonexistent location/etc). 20 // This is strange, but POSIX-correct. 21 // coreutils cp has --remove-destination to override this... 22 // 23 // NB: we have special code which still allows for "cp file /dev/node" 24 // to work POSIX-ly (the only realistic case where it makes sense) 25 26 #define DO_POSIX_CP 0 /* 1 - POSIX behavior, 0 - safe behavior */ 27 28 // errno must be set to relevant value ("why we cannot create dest?") 29 // for POSIX mode to give reasonable error message 30 static int ask_and_unlink(const char *dest, int flags) 31 { 32 #if DO_POSIX_CP 33 if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) { 34 // Either it exists, or the *path* doesnt exist 35 bb_perror_msg("cannot create '%s'", dest); 36 return -1; 37 } 38 #endif 39 // If !DO_POSIX_CP, act as if -f is always in effect - we don't want 40 // "cannot create" msg, we want unlink to be done (silently unless -i). 41 42 // TODO: maybe we should do it only if ctty is present? 43 if (flags & FILEUTILS_INTERACTIVE) { 44 // We would not do POSIX insanity. -i asks, 45 // then _unlinks_ the offender. Presto. 46 // (No "opening without O_EXCL", no "unlink only if -f") 47 // Or else we will end up having 3 open()s! 48 fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest); 49 if (!bb_ask_confirmation()) 50 return 0; // not allowed to overwrite 51 } 52 if (unlink(dest) < 0) { 53 bb_perror_msg("cannot remove '%s'", dest); 54 return -1; // error 55 } 56 return 1; // ok (to try again) 57 } 58 59 /* Return: 60 * -1 error, copy not made 61 * 0 copy is made or user answered "no" in interactive mode 62 * (failures to preserve mode/owner/times are not reported in exit code) 63 */ 15 64 int copy_file(const char *source, const char *dest, int flags) 16 65 { 66 /* This is a recursive function, try to minimize stack usage */ 67 /* NB: each struct stat is ~100 bytes */ 17 68 struct stat source_stat; 18 69 struct stat dest_stat; 19 int dest_exists = 0; 20 int status = 0; 21 22 if ((!(flags & FILEUTILS_DEREFERENCE) && 23 lstat(source, &source_stat) < 0) || 24 ((flags & FILEUTILS_DEREFERENCE) && 25 stat(source, &source_stat) < 0)) { 26 bb_perror_msg("%s", source); 70 signed char retval = 0; 71 signed char dest_exists = 0; 72 signed char ovr; 73 74 #define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE) 75 76 if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) { 77 // This may be a dangling symlink. 78 // Making [sym]links to dangling symlinks works, so... 79 if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) 80 goto make_links; 81 bb_perror_msg("cannot stat '%s'", source); 27 82 return -1; 28 83 } … … 30 85 if (lstat(dest, &dest_stat) < 0) { 31 86 if (errno != ENOENT) { 32 bb_perror_msg(" unable to stat `%s'", dest);87 bb_perror_msg("cannot stat '%s'", dest); 33 88 return -1; 34 89 } 35 90 } else { 36 if (source_stat.st_dev == dest_stat.st_dev &&37 source_stat.st_ino == dest_stat.st_ino)38 {39 bb_error_msg(" `%s' and `%s' are the same file", source, dest);91 if (source_stat.st_dev == dest_stat.st_dev 92 && source_stat.st_ino == dest_stat.st_ino 93 ) { 94 bb_error_msg("'%s' and '%s' are the same file", source, dest); 40 95 return -1; 41 96 } 42 97 dest_exists = 1; 43 98 } 99 100 #if ENABLE_SELINUX 101 if ((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) && is_selinux_enabled() > 0) { 102 security_context_t con; 103 if (lgetfilecon(source, &con) >= 0) { 104 if (setfscreatecon(con) < 0) { 105 bb_perror_msg("cannot set setfscreatecon %s", con); 106 freecon(con); 107 return -1; 108 } 109 } else if (errno == ENOTSUP || errno == ENODATA) { 110 setfscreatecon_or_die(NULL); 111 } else { 112 bb_perror_msg("cannot lgetfilecon %s", source); 113 return -1; 114 } 115 } 116 #endif 44 117 45 118 if (S_ISDIR(source_stat.st_mode)) { 46 119 DIR *dp; 120 const char *tp; 47 121 struct dirent *d; 48 122 mode_t saved_umask = 0; 49 123 50 124 if (!(flags & FILEUTILS_RECUR)) { 51 bb_error_msg("%s: omitting directory", source); 52 return -1; 53 } 54 55 /* Create DEST. */ 125 bb_error_msg("omitting directory '%s'", source); 126 return -1; 127 } 128 129 /* Did we ever create source ourself before? */ 130 tp = is_in_ino_dev_hashtable(&source_stat); 131 if (tp) { 132 /* We did! it's a recursion! man the lifeboats... */ 133 bb_error_msg("recursion detected, omitting directory '%s'", 134 source); 135 return -1; 136 } 137 138 /* Create DEST */ 56 139 if (dest_exists) { 57 140 if (!S_ISDIR(dest_stat.st_mode)) { 58 bb_error_msg("`%s' is not a directory", dest); 59 return -1; 60 } 141 bb_error_msg("target '%s' is not a directory", dest); 142 return -1; 143 } 144 /* race here: user can substitute a symlink between 145 * this check and actual creation of files inside dest */ 61 146 } else { 62 147 mode_t mode; … … 66 151 if (!(flags & FILEUTILS_PRESERVE_STATUS)) 67 152 mode = source_stat.st_mode & ~saved_umask; 153 /* Allow owner to access new dir (at least for now) */ 68 154 mode |= S_IRWXU; 69 70 155 if (mkdir(dest, mode) < 0) { 71 156 umask(saved_umask); 72 bb_perror_msg("cannot create directory `%s'", dest); 73 return -1; 74 } 75 157 bb_perror_msg("cannot create directory '%s'", dest); 158 return -1; 159 } 76 160 umask(saved_umask); 77 } 78 79 /* Recursively copy files in SOURCE. */ 80 if ((dp = bb_opendir(source)) == NULL) { 81 status = -1; 82 goto preserve_status; 161 /* need stat info for add_to_ino_dev_hashtable */ 162 if (lstat(dest, &dest_stat) < 0) { 163 bb_perror_msg("cannot stat '%s'", dest); 164 return -1; 165 } 166 } 167 /* remember (dev,inode) of each created dir. 168 * NULL: name is not remembered */ 169 add_to_ino_dev_hashtable(&dest_stat, NULL); 170 171 /* Recursively copy files in SOURCE */ 172 dp = opendir(source); 173 if (dp == NULL) { 174 retval = -1; 175 goto preserve_mode_ugid_time; 83 176 } 84 177 … … 87 180 88 181 new_source = concat_subpath_file(source, d->d_name); 89 if (new_source == NULL)182 if (new_source == NULL) 90 183 continue; 91 184 new_dest = concat_path_file(dest, d->d_name); 92 185 if (copy_file(new_source, new_dest, flags) < 0) 93 status= -1;186 retval = -1; 94 187 free(new_source); 95 188 free(new_dest); 96 189 } 97 /* closedir have only EBADF error, but "dp" not changes */98 190 closedir(dp); 99 191 100 if (!dest_exists && 101 chmod(dest, source_stat.st_mode & ~saved_umask) < 0) { 102 bb_perror_msg("unable to change permissions of `%s'", dest); 103 status = -1; 104 } 105 } else if (S_ISREG(source_stat.st_mode) || 106 (S_ISLNK(source_stat.st_mode) && (flags & FILEUTILS_DEREFERENCE))) 107 { 192 if (!dest_exists 193 && chmod(dest, source_stat.st_mode & ~saved_umask) < 0 194 ) { 195 bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest); 196 /* retval = -1; - WRONG! copy *WAS* made */ 197 } 198 goto preserve_mode_ugid_time; 199 } 200 201 if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) { 202 int (*lf)(const char *oldpath, const char *newpath); 203 make_links: 204 // Hmm... maybe 205 // if (DEREF && MAKE_SOFTLINK) source = realpath(source) ? 206 // (but realpath returns NULL on dangling symlinks...) 207 lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link; 208 if (lf(source, dest) < 0) { 209 ovr = ask_and_unlink(dest, flags); 210 if (ovr <= 0) 211 return ovr; 212 if (lf(source, dest) < 0) { 213 bb_perror_msg("cannot create link '%s'", dest); 214 return -1; 215 } 216 } 217 /* _Not_ jumping to preserve_mode_ugid_time: 218 * hard/softlinks don't have those */ 219 return 0; 220 } 221 222 if (S_ISREG(source_stat.st_mode) 223 /* DEREF uses stat, which never returns S_ISLNK() == true. */ 224 /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */ 225 ) { 108 226 int src_fd; 109 227 int dst_fd; 110 if (ENABLE_FEATURE_PRESERVE_HARDLINKS) { 111 char *link_name; 112 113 if (!(flags & FILEUTILS_DEREFERENCE) && 114 is_in_ino_dev_hashtable(&source_stat, &link_name)) { 115 if (link(link_name, dest) < 0) { 116 bb_perror_msg("unable to link `%s'", dest); 228 229 if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) { 230 const char *link_target; 231 link_target = is_in_ino_dev_hashtable(&source_stat); 232 if (link_target) { 233 if (link(link_target, dest) < 0) { 234 ovr = ask_and_unlink(dest, flags); 235 if (ovr <= 0) 236 return ovr; 237 if (link(link_target, dest) < 0) { 238 bb_perror_msg("cannot create link '%s'", dest); 239 return -1; 240 } 241 } 242 return 0; 243 } 244 add_to_ino_dev_hashtable(&source_stat, dest); 245 } 246 247 src_fd = open_or_warn(source, O_RDONLY); 248 if (src_fd < 0) 249 return -1; 250 251 /* POSIX way is a security problem versus symlink attacks, 252 * we do it only for non-symlinks, and only for non-recursive, 253 * non-interactive cp. NB: it is still racy 254 * for "cp file /home/bad_user/file" case 255 * (user can rm file and create a link to /etc/passwd) */ 256 if (DO_POSIX_CP 257 || (dest_exists && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE)) 258 && !S_ISLNK(dest_stat.st_mode)) 259 ) { 260 dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode); 261 } else /* safe way: */ 262 dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_mode); 263 if (dst_fd == -1) { 264 ovr = ask_and_unlink(dest, flags); 265 if (ovr <= 0) { 266 close(src_fd); 267 return ovr; 268 } 269 /* It shouldn't exist. If it exists, do not open (symlink attack?) */ 270 dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_mode); 271 if (dst_fd < 0) { 272 close(src_fd); 273 return -1; 274 } 275 } 276 277 #if ENABLE_SELINUX 278 if (((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) 279 || (flags & FILEUTILS_SET_SECURITY_CONTEXT)) 280 && is_selinux_enabled() > 0 281 ) { 282 security_context_t con; 283 if (getfscreatecon(&con) == -1) { 284 bb_perror_msg("getfscreatecon"); 285 return -1; 286 } 287 if (con) { 288 if (setfilecon(dest, con) == -1) { 289 bb_perror_msg("setfilecon:%s,%s", dest, con); 290 freecon(con); 117 291 return -1; 118 292 } 119 120 return 0; 121 } 122 add_to_ino_dev_hashtable(&source_stat, dest); 123 } 124 src_fd = open(source, O_RDONLY); 125 if (src_fd == -1) { 126 bb_perror_msg("unable to open `%s'", source); 127 return(-1); 128 } 129 130 if (dest_exists) { 131 if (flags & FILEUTILS_INTERACTIVE) { 132 fprintf(stderr, "%s: overwrite `%s'? ", bb_applet_name, dest); 133 if (!bb_ask_confirmation()) { 134 close (src_fd); 135 return 0; 136 } 137 } 138 139 dst_fd = open(dest, O_WRONLY|O_TRUNC); 140 if (dst_fd == -1) { 141 if (!(flags & FILEUTILS_FORCE)) { 142 bb_perror_msg("unable to open `%s'", dest); 143 close(src_fd); 144 return -1; 145 } 146 147 if (unlink(dest) < 0) { 148 bb_perror_msg("unable to remove `%s'", dest); 149 close(src_fd); 150 return -1; 151 } 152 153 goto dest_removed; 154 } 155 } else { 156 dest_removed: 157 dst_fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode); 158 if (dst_fd == -1) { 159 bb_perror_msg("unable to open `%s'", dest); 160 close(src_fd); 161 return(-1); 162 } 163 } 164 293 freecon(con); 294 } 295 } 296 #endif 165 297 if (bb_copyfd_eof(src_fd, dst_fd) == -1) 166 status= -1;167 298 retval = -1; 299 /* Ok, writing side I can understand... */ 168 300 if (close(dst_fd) < 0) { 169 bb_perror_msg("unable to close `%s'", dest); 170 status = -1; 171 } 172 173 if (close(src_fd) < 0) { 174 bb_perror_msg("unable to close `%s'", source); 175 status = -1; 176 } 177 } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) || 178 S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) || 179 S_ISLNK(source_stat.st_mode)) { 180 181 if (dest_exists) { 182 if((flags & FILEUTILS_FORCE) == 0) { 183 fprintf(stderr, "`%s' exists\n", dest); 184 return -1; 185 } 186 if(unlink(dest) < 0) { 187 bb_perror_msg("unable to remove `%s'", dest); 188 return -1; 189 } 190 } 191 if (S_ISFIFO(source_stat.st_mode)) { 192 if (mkfifo(dest, source_stat.st_mode) < 0) { 193 bb_perror_msg("cannot create fifo `%s'", dest); 194 return -1; 195 } 196 } else if (S_ISLNK(source_stat.st_mode)) { 197 char *lpath; 198 199 lpath = xreadlink(source); 200 if (symlink(lpath, dest) < 0) { 201 bb_perror_msg("cannot create symlink `%s'", dest); 202 return -1; 203 } 301 bb_perror_msg("cannot close '%s'", dest); 302 retval = -1; 303 } 304 /* ...but read size is already checked by bb_copyfd_eof */ 305 close(src_fd); 306 goto preserve_mode_ugid_time; 307 } 308 309 /* Source is a symlink or a special file */ 310 /* We are lazy here, a bit lax with races... */ 311 if (dest_exists) { 312 errno = EEXIST; 313 ovr = ask_and_unlink(dest, flags); 314 if (ovr <= 0) 315 return ovr; 316 } 317 if (S_ISLNK(source_stat.st_mode)) { 318 char *lpath = xmalloc_readlink_or_warn(source); 319 if (lpath) { 320 int r = symlink(lpath, dest); 204 321 free(lpath); 205 322 if (r < 0) { 323 bb_perror_msg("cannot create symlink '%s'", dest); 324 return -1; 325 } 206 326 if (flags & FILEUTILS_PRESERVE_STATUS) 207 327 if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0) 208 bb_perror_msg("unable to preserve ownership of `%s'", dest); 209 210 return 0; 211 212 } else { 213 if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { 214 bb_perror_msg("unable to create `%s'", dest); 215 return -1; 216 } 328 bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest); 329 } 330 /* _Not_ jumping to preserve_mode_ugid_time: 331 * symlinks don't have those */ 332 return 0; 333 } 334 if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) 335 || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) 336 ) { 337 if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { 338 bb_perror_msg("cannot create '%s'", dest); 339 return -1; 217 340 } 218 341 } else { 219 bb_error_msg(" internal error: unrecognized file type");342 bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode); 220 343 return -1; 221 344 } 222 345 223 preserve_status: 224 225 if (flags & FILEUTILS_PRESERVE_STATUS) { 346 preserve_mode_ugid_time: 347 348 if (flags & FILEUTILS_PRESERVE_STATUS 349 /* Cannot happen: */ 350 /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */ 351 ) { 226 352 struct utimbuf times; 227 char *msg="unable to preserve %s of `%s'";228 353 229 354 times.actime = source_stat.st_atime; 230 355 times.modtime = source_stat.st_mtime; 356 /* BTW, utimes sets usec-precision time - just FYI */ 231 357 if (utime(dest, ×) < 0) 232 bb_perror_msg( msg, "times", dest);358 bb_perror_msg("cannot preserve %s of '%s'", "times", dest); 233 359 if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) { 234 360 source_stat.st_mode &= ~(S_ISUID | S_ISGID); 235 bb_perror_msg( msg, "ownership", dest);361 bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest); 236 362 } 237 363 if (chmod(dest, source_stat.st_mode) < 0) 238 bb_perror_msg( msg, "permissions", dest);239 } 240 241 return status;364 bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest); 365 } 366 367 return retval; 242 368 }
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