1 /* $OpenBSD: rm.c,v 1.29 2014/05/21 06:23:02 guenther Exp $ */ 2 /* $NetBSD: rm.c,v 1.19 1995/09/07 06:48:50 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1990, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 #include <sys/param.h> 36 #include <sys/mount.h> 37 38 #include <locale.h> 39 #include <err.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <fts.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include <pwd.h> 48 #include <grp.h> 49 50 extern char *__progname; 51 52 int dflag, eval, fflag, iflag, Pflag, stdin_ok; 53 54 int check(char *, char *, struct stat *); 55 void checkdot(char **); 56 void rm_file(char **); 57 int rm_overwrite(char *, struct stat *); 58 int pass(int, off_t, char *, size_t); 59 void rm_tree(char **); 60 void usage(void); 61 62 /* 63 * rm -- 64 * This rm is different from historic rm's, but is expected to match 65 * POSIX 1003.2 behavior. The most visible difference is that -f 66 * has two specific effects now, ignore non-existent files and force 67 * file removal. 68 */ 69 int 70 main(int argc, char *argv[]) 71 { 72 int ch, rflag; 73 74 setlocale(LC_ALL, ""); 75 76 Pflag = rflag = 0; 77 while ((ch = getopt(argc, argv, "dfiPRr")) != -1) 78 switch(ch) { 79 case 'd': 80 dflag = 1; 81 break; 82 case 'f': 83 fflag = 1; 84 iflag = 0; 85 break; 86 case 'i': 87 fflag = 0; 88 iflag = 1; 89 break; 90 case 'P': 91 Pflag = 1; 92 break; 93 case 'R': 94 case 'r': /* Compatibility. */ 95 rflag = 1; 96 break; 97 default: 98 usage(); 99 } 100 argc -= optind; 101 argv += optind; 102 103 if (argc < 1 && fflag == 0) 104 usage(); 105 106 checkdot(argv); 107 108 if (*argv) { 109 stdin_ok = isatty(STDIN_FILENO); 110 111 if (rflag) 112 rm_tree(argv); 113 else 114 rm_file(argv); 115 } 116 117 exit (eval); 118 } 119 120 void 121 rm_tree(char **argv) 122 { 123 FTS *fts; 124 FTSENT *p; 125 int needstat; 126 int flags; 127 128 /* 129 * Remove a file hierarchy. If forcing removal (-f), or interactive 130 * (-i) or can't ask anyway (stdin_ok), don't stat the file. 131 */ 132 needstat = !fflag && !iflag && stdin_ok; 133 134 /* 135 * If the -i option is specified, the user can skip on the pre-order 136 * visit. The fts_number field flags skipped directories. 137 */ 138 #define SKIPPED 1 139 140 flags = FTS_PHYSICAL; 141 if (!needstat) 142 flags |= FTS_NOSTAT; 143 if (!(fts = fts_open(argv, flags, NULL))) 144 err(1, NULL); 145 while ((p = fts_read(fts)) != NULL) { 146 switch (p->fts_info) { 147 case FTS_DNR: 148 if (!fflag || p->fts_errno != ENOENT) { 149 warnx("%s: %s", 150 p->fts_path, strerror(p->fts_errno)); 151 eval = 1; 152 } 153 continue; 154 case FTS_ERR: 155 errc(1, p->fts_errno, "%s", p->fts_path); 156 case FTS_NS: 157 /* 158 * FTS_NS: assume that if can't stat the file, it 159 * can't be unlinked. 160 */ 161 if (!needstat) 162 break; 163 if (!fflag || p->fts_errno != ENOENT) { 164 warnx("%s: %s", 165 p->fts_path, strerror(p->fts_errno)); 166 eval = 1; 167 } 168 continue; 169 case FTS_D: 170 /* Pre-order: give user chance to skip. */ 171 if (!fflag && !check(p->fts_path, p->fts_accpath, 172 p->fts_statp)) { 173 (void)fts_set(fts, p, FTS_SKIP); 174 p->fts_number = SKIPPED; 175 } 176 continue; 177 case FTS_DP: 178 /* Post-order: see if user skipped. */ 179 if (p->fts_number == SKIPPED) 180 continue; 181 break; 182 default: 183 if (!fflag && 184 !check(p->fts_path, p->fts_accpath, p->fts_statp)) 185 continue; 186 } 187 188 /* 189 * If we can't read or search the directory, may still be 190 * able to remove it. Don't print out the un{read,search}able 191 * message unless the remove fails. 192 */ 193 switch (p->fts_info) { 194 case FTS_DP: 195 case FTS_DNR: 196 if (!rmdir(p->fts_accpath) || 197 (fflag && errno == ENOENT)) 198 continue; 199 break; 200 201 case FTS_F: 202 case FTS_NSOK: 203 if (Pflag) 204 rm_overwrite(p->fts_accpath, p->fts_info == 205 FTS_NSOK ? NULL : p->fts_statp); 206 /* FALLTHROUGH */ 207 default: 208 if (!unlink(p->fts_accpath) || 209 (fflag && errno == ENOENT)) 210 continue; 211 } 212 warn("%s", p->fts_path); 213 eval = 1; 214 } 215 if (errno) 216 err(1, "fts_read"); 217 fts_close(fts); 218 } 219 220 void 221 rm_file(char **argv) 222 { 223 struct stat sb; 224 int rval; 225 char *f; 226 227 /* 228 * Remove a file. POSIX 1003.2 states that, by default, attempting 229 * to remove a directory is an error, so must always stat the file. 230 */ 231 while ((f = *argv++) != NULL) { 232 /* Assume if can't stat the file, can't unlink it. */ 233 if (lstat(f, &sb)) { 234 if (!fflag || errno != ENOENT) { 235 warn("%s", f); 236 eval = 1; 237 } 238 continue; 239 } 240 241 if (S_ISDIR(sb.st_mode) && !dflag) { 242 warnx("%s: is a directory", f); 243 eval = 1; 244 continue; 245 } 246 if (!fflag && !check(f, f, &sb)) 247 continue; 248 else if (S_ISDIR(sb.st_mode)) 249 rval = rmdir(f); 250 else { 251 if (Pflag) 252 rm_overwrite(f, &sb); 253 rval = unlink(f); 254 } 255 if (rval && (!fflag || errno != ENOENT)) { 256 warn("%s", f); 257 eval = 1; 258 } 259 } 260 } 261 262 /* 263 * rm_overwrite -- 264 * Overwrite the file with varying bit patterns. 265 * 266 * XXX 267 * This is a cheap way to *really* delete files. Note that only regular 268 * files are deleted, directories (and therefore names) will remain. 269 * Also, this assumes a fixed-block file system (like FFS, or a V7 or a 270 * System V file system). In a logging file system, you'll have to have 271 * kernel support. 272 * Returns 1 for success. 273 */ 274 int 275 rm_overwrite(char *file, struct stat *sbp) 276 { 277 struct stat sb, sb2; 278 struct statfs fsb; 279 size_t bsize; 280 int fd; 281 char *buf = NULL; 282 283 fd = -1; 284 if (sbp == NULL) { 285 if (lstat(file, &sb)) 286 goto err; 287 sbp = &sb; 288 } 289 if (!S_ISREG(sbp->st_mode)) 290 return (1); 291 if (sbp->st_nlink > 1) { 292 warnx("%s (inode %llu): not overwritten due to multiple links", 293 file, (unsigned long long)sbp->st_ino); 294 return (0); 295 } 296 if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1) 297 goto err; 298 if (fstat(fd, &sb2)) 299 goto err; 300 if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino || 301 !S_ISREG(sb2.st_mode)) { 302 errno = EPERM; 303 goto err; 304 } 305 if (fstatfs(fd, &fsb) == -1) 306 goto err; 307 bsize = MAX(fsb.f_iosize, 1024U); 308 if ((buf = malloc(bsize)) == NULL) 309 err(1, "%s: malloc", file); 310 311 if (!pass(fd, sbp->st_size, buf, bsize)) 312 goto err; 313 if (fsync(fd)) 314 goto err; 315 close(fd); 316 free(buf); 317 return (1); 318 319 err: 320 warn("%s", file); 321 close(fd); 322 eval = 1; 323 free(buf); 324 return (0); 325 } 326 327 int 328 pass(int fd, off_t len, char *buf, size_t bsize) 329 { 330 size_t wlen; 331 332 for (; len > 0; len -= wlen) { 333 wlen = len < bsize ? len : bsize; 334 arc4random_buf(buf, wlen); 335 if (write(fd, buf, wlen) != wlen) 336 return (0); 337 } 338 return (1); 339 } 340 341 int 342 check(char *path, char *name, struct stat *sp) 343 { 344 int ch, first; 345 char modep[15]; 346 347 /* Check -i first. */ 348 if (iflag) 349 (void)fprintf(stderr, "remove %s? ", path); 350 else { 351 /* 352 * If it's not a symbolic link and it's unwritable and we're 353 * talking to a terminal, ask. Symbolic links are excluded 354 * because their permissions are meaningless. Check stdin_ok 355 * first because we may not have stat'ed the file. 356 */ 357 if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK) || 358 errno != EACCES) 359 return (1); 360 strmode(sp->st_mode, modep); 361 (void)fprintf(stderr, "override %s%s%s/%s for %s? ", 362 modep + 1, modep[9] == ' ' ? "" : " ", 363 user_from_uid(sp->st_uid, 0), 364 group_from_gid(sp->st_gid, 0), path); 365 } 366 (void)fflush(stderr); 367 368 first = ch = getchar(); 369 while (ch != '\n' && ch != EOF) 370 ch = getchar(); 371 return (first == 'y' || first == 'Y'); 372 } 373 374 /* 375 * POSIX.2 requires that if "." or ".." are specified as the basename 376 * portion of an operand, a diagnostic message be written to standard 377 * error and nothing more be done with such operands. 378 * 379 * Since POSIX.2 defines basename as the final portion of a path after 380 * trailing slashes have been removed, we'll remove them here. 381 */ 382 #define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2]))) 383 void 384 checkdot(char **argv) 385 { 386 char *p, **save, **t; 387 int complained; 388 389 complained = 0; 390 for (t = argv; *t;) { 391 /* strip trailing slashes */ 392 p = strrchr (*t, '\0'); 393 while (--p > *t && *p == '/') 394 *p = '\0'; 395 396 /* extract basename */ 397 if ((p = strrchr(*t, '/')) != NULL) 398 ++p; 399 else 400 p = *t; 401 402 if (ISDOT(p)) { 403 if (!complained++) 404 warnx("\".\" and \"..\" may not be removed"); 405 eval = 1; 406 for (save = t; (t[0] = t[1]) != NULL; ++t) 407 continue; 408 t = save; 409 } else 410 ++t; 411 } 412 } 413 414 void 415 usage(void) 416 { 417 (void)fprintf(stderr, "usage: %s [-dfiPRr] file ...\n", __progname); 418 exit(1); 419 } 420