bin/rm/rm.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if 0
  31 #ifndef lint
  32 static const char copyright[] =
  33 "@(#) Copyright (c) 1990, 1993, 1994\n\
  34         The Regents of the University of California.  All rights reserved.\n";
  35 #endif /* not lint */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  39 #endif /* not lint */
  40 #endif
  41 #include <sys/cdefs.h>
  42 __FBSDID("$FreeBSD$");
  43
  44 #include <sys/stat.h>
  45 #include <sys/param.h>
  46 #include <sys/mount.h>
  47
  48 #include <err.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <fts.h>
  52 #include <grp.h>
  53 #include <pwd.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <sysexits.h>
  58 #include <unistd.h>
  59
  60 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  61 int rflag, Iflag;
  62 uid_t uid;
  63 volatile sig_atomic_t info;
  64
  65 static int      check(const char *, const char *, struct stat *);
  66 static int      check2(char **);
  67 static void     checkdot(char **);
  68 static void     checkslash(char **);
  69 static void     rm_file(char **);
  70 static int      rm_overwrite(const char *, struct stat *);
  71 static void     rm_tree(char **);
  72 static void siginfo(int __unused);
  73 static void     usage(void);
  74
  75 /*
  76  * rm --
  77  *      This rm is different from historic rm's, but is expected to match
  78  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  79  *      has two specific effects now, ignore non-existent files and force
  80  *      file removal.
  81  */
  82 int
  83 main(int argc, char *argv[])
  84 {
  85         int ch;
  86         char *p;
  87
  88         /*
  89          * Test for the special case where the utility is called as
  90          * "unlink", for which the functionality provided is greatly
  91          * simplified.
  92          */
  93         if ((p = strrchr(argv[0], '/')) == NULL)
  94                 p = argv[0];
  95         else
  96                 ++p;
  97         if (strcmp(p, "unlink") == 0) {
  98                 while (getopt(argc, argv, "") != -1)
  99                         usage();
 100                 argc -= optind;
 101                 argv += optind;
 102                 if (argc != 1)
 103                         usage();
 104                 rm_file(&argv[0]);
 105                 exit(eval);
 106         }
 107
 108         Pflag = rflag = 0;
 109         while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1)
 110                 switch(ch) {
 111                 case 'd':
 112                         dflag = 1;
 113                         break;
 114                 case 'f':
 115                         fflag = 1;
 116                         iflag = 0;
 117                         break;
 118                 case 'i':
 119                         fflag = 0;
 120                         iflag = 1;
 121                         break;
 122                 case 'I':
 123                         Iflag = 1;
 124                         break;
 125                 case 'P':
 126                         Pflag = 1;
 127                         break;
 128                 case 'R':
 129                 case 'r':                       /* Compatibility. */
 130                         rflag = 1;
 131                         break;
 132                 case 'v':
 133                         vflag = 1;
 134                         break;
 135                 case 'W':
 136                         Wflag = 1;
 137                         break;
 138                 default:
 139                         usage();
 140                 }
 141         argc -= optind;
 142         argv += optind;
 143
 144         if (argc < 1) {
 145                 if (fflag)
 146                         return (0);
 147                 usage();
 148         }
 149
 150         checkdot(argv);
 151         if (getenv("POSIXLY_CORRECT") == NULL)
 152                 checkslash(argv);
 153         uid = geteuid();
 154
 155         (void)signal(SIGINFO, siginfo);
 156         if (*argv) {
 157                 stdin_ok = isatty(STDIN_FILENO);
 158
 159                 if (Iflag) {
 160                         if (check2(argv) == 0)
 161                                 exit (1);
 162                 }
 163                 if (rflag)
 164                         rm_tree(argv);
 165                 else
 166                         rm_file(argv);
 167         }
 168
 169         exit (eval);
 170 }
 171
 172 static void
 173 rm_tree(char **argv)
 174 {
 175         FTS *fts;
 176         FTSENT *p;
 177         int needstat;
 178         int flags;
 179         int rval;
 180
 181         /*
 182          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 183          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 184          */
 185         needstat = !uid || (!fflag && !iflag && stdin_ok);
 186
 187         /*
 188          * If the -i option is specified, the user can skip on the pre-order
 189          * visit.  The fts_number field flags skipped directories.
 190          */
 191 #define SKIPPED 1
 192
 193         flags = FTS_PHYSICAL;
 194         if (!needstat)
 195                 flags |= FTS_NOSTAT;
 196         if (Wflag)
 197                 flags |= FTS_WHITEOUT;
 198         if (!(fts = fts_open(argv, flags, NULL))) {
 199                 if (fflag && errno == ENOENT)
 200                         return;
 201                 err(1, "fts_open");
 202         }
 203         while ((p = fts_read(fts)) != NULL) {
 204                 switch (p->fts_info) {
 205                 case FTS_DNR:
 206                         if (!fflag || p->fts_errno != ENOENT) {
 207                                 warnx("%s: %s",
 208                                     p->fts_path, strerror(p->fts_errno));
 209                                 eval = 1;
 210                         }
 211                         continue;
 212                 case FTS_ERR:
 213                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 214                 case FTS_NS:
 215                         /*
 216                          * Assume that since fts_read() couldn't stat the
 217                          * file, it can't be unlinked.
 218                          */
 219                         if (!needstat)
 220                                 break;
 221                         if (!fflag || p->fts_errno != ENOENT) {
 222                                 warnx("%s: %s",
 223                                     p->fts_path, strerror(p->fts_errno));
 224                                 eval = 1;
 225                         }
 226                         continue;
 227                 case FTS_D:
 228                         /* Pre-order: give user chance to skip. */
 229                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 230                             p->fts_statp)) {
 231                                 (void)fts_set(fts, p, FTS_SKIP);
 232                                 p->fts_number = SKIPPED;
 233                         }
 234                         else if (!uid &&
 235                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 236                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 237                                  lchflags(p->fts_accpath,
 238                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 239                                 goto err;
 240                         continue;
 241                 case FTS_DP:
 242                         /* Post-order: see if user skipped. */
 243                         if (p->fts_number == SKIPPED)
 244                                 continue;
 245                         break;
 246                 default:
 247                         if (!fflag &&
 248                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 249                                 continue;
 250                 }
 251
 252                 rval = 0;
 253                 if (!uid &&
 254                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 255                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 256                         rval = lchflags(p->fts_accpath,
 257                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 258                 if (rval == 0) {
 259                         /*
 260                          * If we can't read or search the directory, may still be
 261                          * able to remove it.  Don't print out the un{read,search}able
 262                          * message unless the remove fails.
 263                          */
 264                         switch (p->fts_info) {
 265                         case FTS_DP:
 266                         case FTS_DNR:
 267                                 rval = rmdir(p->fts_accpath);
 268                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 269                                         if (rval == 0 && vflag)
 270                                                 (void)printf("%s\n",
 271                                                     p->fts_path);
 272                                         if (rval == 0 && info) {
 273                                                 info = 0;
 274                                                 (void)printf("%s\n",
 275                                                     p->fts_path);
 276                                         }
 277                                         continue;
 278                                 }
 279                                 break;
 280
 281                         case FTS_W:
 282                                 rval = undelete(p->fts_accpath);
 283                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 284                                         if (vflag)
 285                                                 (void)printf("%s\n",
 286                                                     p->fts_path);
 287                                         if (info) {
 288                                                 info = 0;
 289                                                 (void)printf("%s\n",
 290                                                     p->fts_path);
 291                                         }
 292                                         continue;
 293                                 }
 294                                 break;
 295
 296                         case FTS_NS:
 297                                 /*
 298                                  * Assume that since fts_read() couldn't stat
 299                                  * the file, it can't be unlinked.
 300                                  */
 301                                 if (fflag)
 302                                         continue;
 303                                 /* FALLTHROUGH */
 304
 305                         case FTS_F:
 306                         case FTS_NSOK:
 307                                 if (Pflag)
 308                                         if (!rm_overwrite(p->fts_accpath, p->fts_info ==
 309                                             FTS_NSOK ? NULL : p->fts_statp))
 310                                                 continue;
 311                                 /* FALLTHROUGH */
 312
 313                         default:
 314                                 rval = unlink(p->fts_accpath);
 315                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 316                                         if (rval == 0 && vflag)
 317                                                 (void)printf("%s\n",
 318                                                     p->fts_path);
 319                                         if (rval == 0 && info) {
 320                                                 info = 0;
 321                                                 (void)printf("%s\n",
 322                                                     p->fts_path);
 323                                         }
 324                                         continue;
 325                                 }
 326                         }
 327                 }
 328 err:
 329                 warn("%s", p->fts_path);
 330                 eval = 1;
 331         }
 332         if (errno)
 333                 err(1, "fts_read");
 334         fts_close(fts);
 335 }
 336
 337 void
 338 rm_file(char **argv)
 339 {
 340         struct stat sb;
 341         int rval;
 342         char *f;
 343
 344         /*
 345          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 346          * to remove a directory is an error, so must always stat the file.
 347          */
 348         while ((f = *argv++) != NULL) {
 349                 /* Assume if can't stat the file, can't unlink it. */
 350                 if (lstat(f, &sb)) {
 351                         if (Wflag) {
 352                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 353                         } else {
 354                                 if (!fflag || errno != ENOENT) {
 355                                         warn("%s", f);
 356                                         eval = 1;
 357                                 }
 358                                 continue;
 359                         }
 360                 } else if (Wflag) {
 361                         warnx("%s: %s", f, strerror(EEXIST));
 362                         eval = 1;
 363                         continue;
 364                 }
 365
 366                 if (S_ISDIR(sb.st_mode) && !dflag) {
 367                         warnx("%s: is a directory", f);
 368                         eval = 1;
 369                         continue;
 370                 }
 371                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 372                         continue;
 373                 rval = 0;
 374                 if (!uid && !S_ISWHT(sb.st_mode) &&
 375                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 376                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 377                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 378                 if (rval == 0) {
 379                         if (S_ISWHT(sb.st_mode))
 380                                 rval = undelete(f);
 381                         else if (S_ISDIR(sb.st_mode))
 382                                 rval = rmdir(f);
 383                         else {
 384                                 if (Pflag)
 385                                         if (!rm_overwrite(f, &sb))
 386                                                 continue;
 387                                 rval = unlink(f);
 388                         }
 389                 }
 390                 if (rval && (!fflag || errno != ENOENT)) {
 391                         warn("%s", f);
 392                         eval = 1;
 393                 }
 394                 if (vflag && rval == 0)
 395                         (void)printf("%s\n", f);
 396                 if (info && rval == 0) {
 397                         info = 0;
 398                         (void)printf("%s\n", f);
 399                 }
 400         }
 401 }
 402
 403 /*
 404  * rm_overwrite --
 405  *      Overwrite the file 3 times with varying bit patterns.
 406  *
 407  * XXX
 408  * This is a cheap way to *really* delete files.  Note that only regular
 409  * files are deleted, directories (and therefore names) will remain.
 410  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 411  * System V file system).  In a logging or COW file system, you'll have to
 412  * have kernel support.
 413  */
 414 int
 415 rm_overwrite(const char *file, struct stat *sbp)
 416 {
 417         struct stat sb, sb2;
 418         struct statfs fsb;
 419         off_t len;
 420         int bsize, fd, wlen;
 421         char *buf = NULL;
 422
 423         fd = -1;
 424         if (sbp == NULL) {
 425                 if (lstat(file, &sb))
 426                         goto err;
 427                 sbp = &sb;
 428         }
 429         if (!S_ISREG(sbp->st_mode))
 430                 return (1);
 431         if (sbp->st_nlink > 1 && !fflag) {
 432                 warnx("%s (inode %u): not overwritten due to multiple links",
 433                     file, sbp->st_ino);
 434                 return (0);
 435         }
 436         if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
 437                 goto err;
 438         if (fstat(fd, &sb2))
 439                 goto err;
 440         if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
 441             !S_ISREG(sb2.st_mode)) {
 442                 errno = EPERM;
 443                 goto err;
 444         }
 445         if (fstatfs(fd, &fsb) == -1)
 446                 goto err;
 447         bsize = MAX(fsb.f_iosize, 1024);
 448         if ((buf = malloc(bsize)) == NULL)
 449                 err(1, "%s: malloc", file);
 450
 451 #define PASS(byte) {                                                    \
 452         memset(buf, byte, bsize);                                       \
 453         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 454                 wlen = len < bsize ? len : bsize;                       \
 455                 if (write(fd, buf, wlen) != wlen)                       \
 456                         goto err;                                       \
 457         }                                                               \
 458 }
 459         PASS(0xff);
 460         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 461                 goto err;
 462         PASS(0x00);
 463         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 464                 goto err;
 465         PASS(0xff);
 466         if (!fsync(fd) && !close(fd)) {
 467                 free(buf);
 468                 return (1);
 469         }
 470
 471 err:    eval = 1;
 472         if (buf)
 473                 free(buf);
 474         if (fd != -1)
 475                 close(fd);
 476         warn("%s", file);
 477         return (0);
 478 }
 479
 480
 481 static int
 482 check(const char *path, const char *name, struct stat *sp)
 483 {
 484         int ch, first;
 485         char modep[15], *flagsp;
 486
 487         /* Check -i first. */
 488         if (iflag)
 489                 (void)fprintf(stderr, "remove %s? ", path);
 490         else {
 491                 /*
 492                  * If it's not a symbolic link and it's unwritable and we're
 493                  * talking to a terminal, ask.  Symbolic links are excluded
 494                  * because their permissions are meaningless.  Check stdin_ok
 495                  * first because we may not have stat'ed the file.
 496                  */
 497                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 498                     (!access(name, W_OK) &&
 499                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 500                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 501                         return (1);
 502                 strmode(sp->st_mode, modep);
 503                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 504                         err(1, "fflagstostr");
 505                 if (Pflag)
 506                         errx(1,
 507                             "%s: -P was specified, but file is not writable",
 508                             path);
 509                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 510                     modep + 1, modep[9] == ' ' ? "" : " ",
 511                     user_from_uid(sp->st_uid, 0),
 512                     group_from_gid(sp->st_gid, 0),
 513                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 514                     path);
 515                 free(flagsp);
 516         }
 517         (void)fflush(stderr);
 518
 519         first = ch = getchar();
 520         while (ch != '\n' && ch != EOF)
 521                 ch = getchar();
 522         return (first == 'y' || first == 'Y');
 523 }
 524
 525 #define ISSLASH(a)      ((a)[0] == '/' && (a)[1] == '\0')
 526 static void
 527 checkslash(char **argv)
 528 {
 529         char **t, **u;
 530         int complained;
 531
 532         complained = 0;
 533         for (t = argv; *t;) {
 534                 if (ISSLASH(*t)) {
 535                         if (!complained++)
 536                                 warnx("\"/\" may not be removed");
 537                         eval = 1;
 538                         for (u = t; u[0] != NULL; ++u)
 539                                 u[0] = u[1];
 540                 } else {
 541                         ++t;
 542                 }
 543         }
 544 }
 545
 546 static int
 547 check2(char **argv)
 548 {
 549         struct stat st;
 550         int first;
 551         int ch;
 552         int fcount = 0;
 553         int dcount = 0;
 554         int i;
 555         const char *dname = NULL;
 556
 557         for (i = 0; argv[i]; ++i) {
 558                 if (lstat(argv[i], &st) == 0) {
 559                         if (S_ISDIR(st.st_mode)) {
 560                                 ++dcount;
 561                                 dname = argv[i];    /* only used if 1 dir */
 562                         } else {
 563                                 ++fcount;
 564                         }
 565                 }
 566         }
 567         first = 0;
 568         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 569                 if (dcount && rflag) {
 570                         fprintf(stderr, "recursively remove");
 571                         if (dcount == 1)
 572                                 fprintf(stderr, " %s", dname);
 573                         else
 574                                 fprintf(stderr, " %d dirs", dcount);
 575                         if (fcount == 1)
 576                                 fprintf(stderr, " and 1 file");
 577                         else if (fcount > 1)
 578                                 fprintf(stderr, " and %d files", fcount);
 579                 } else if (dcount + fcount > 3) {
 580                         fprintf(stderr, "remove %d files", dcount + fcount);
 581                 } else {
 582                         return(1);
 583                 }
 584                 fprintf(stderr, "? ");
 585                 fflush(stderr);
 586
 587                 first = ch = getchar();
 588                 while (ch != '\n' && ch != EOF)
 589                         ch = getchar();
 590                 if (ch == EOF)
 591                         break;
 592         }
 593         return (first == 'y' || first == 'Y');
 594 }
 595
 596 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 597 static void
 598 checkdot(char **argv)
 599 {
 600         char *p, **save, **t;
 601         int complained;
 602
 603         complained = 0;
 604         for (t = argv; *t;) {
 605                 if ((p = strrchr(*t, '/')) != NULL)
 606                         ++p;
 607                 else
 608                         p = *t;
 609                 if (ISDOT(p)) {
 610                         if (!complained++)
 611                                 warnx("\".\" and \"..\" may not be removed");
 612                         eval = 1;
 613                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 614                                 continue;
 615                         t = save;
 616                 } else
 617                         ++t;
 618         }
 619 }
 620
 621 static void
 622 usage(void)
 623 {
 624
 625         (void)fprintf(stderr, "%s\n%s\n",
 626             "usage: rm [-f | -i] [-dIPRrvW] file ...",
 627             "       unlink file");
 628         exit(EX_USAGE);
 629 }
 630
 631 static void
 632 siginfo(int sig __unused)
 633 {
 634
 635         info = 1;
 636 }