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 <locale.h>
  54 #include <pwd.h>
  55 #include <stdint.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <sysexits.h>
  60 #include <unistd.h>
  61
  62 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  63 static int rflag, Iflag, xflag;
  64 static uid_t uid;
  65 static volatile sig_atomic_t info;
  66
  67 static int      check(const char *, const char *, struct stat *);
  68 static int      check2(char **);
  69 static void     checkdot(char **);
  70 static void     checkslash(char **);
  71 static void     rm_file(char **);
  72 static int      rm_overwrite(const char *, struct stat *);
  73 static void     rm_tree(char **);
  74 static void siginfo(int __unused);
  75 static void     usage(void);
  76
  77 /*
  78  * rm --
  79  *      This rm is different from historic rm's, but is expected to match
  80  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  81  *      has two specific effects now, ignore non-existent files and force
  82  *      file removal.
  83  */
  84 int
  85 main(int argc, char *argv[])
  86 {
  87         int ch;
  88         char *p;
  89
  90         (void)setlocale(LC_ALL, "");
  91
  92         /*
  93          * Test for the special case where the utility is called as
  94          * "unlink", for which the functionality provided is greatly
  95          * simplified.
  96          */
  97         if ((p = strrchr(argv[0], '/')) == NULL)
  98                 p = argv[0];
  99         else
 100                 ++p;
 101         if (strcmp(p, "unlink") == 0) {
 102                 while (getopt(argc, argv, "") != -1)
 103                         usage();
 104                 argc -= optind;
 105                 argv += optind;
 106                 if (argc != 1)
 107                         usage();
 108                 rm_file(&argv[0]);
 109                 exit(eval);
 110         }
 111
 112         Pflag = rflag = xflag = 0;
 113         while ((ch = getopt(argc, argv, "dfiIPRrvWx")) != -1)
 114                 switch(ch) {
 115                 case 'd':
 116                         dflag = 1;
 117                         break;
 118                 case 'f':
 119                         fflag = 1;
 120                         iflag = 0;
 121                         break;
 122                 case 'i':
 123                         fflag = 0;
 124                         iflag = 1;
 125                         break;
 126                 case 'I':
 127                         Iflag = 1;
 128                         break;
 129                 case 'P':
 130                         Pflag = 1;
 131                         break;
 132                 case 'R':
 133                 case 'r':                       /* Compatibility. */
 134                         rflag = 1;
 135                         break;
 136                 case 'v':
 137                         vflag = 1;
 138                         break;
 139                 case 'W':
 140                         Wflag = 1;
 141                         break;
 142                 case 'x':
 143                         xflag = 1;
 144                         break;
 145                 default:
 146                         usage();
 147                 }
 148         argc -= optind;
 149         argv += optind;
 150
 151         if (argc < 1) {
 152                 if (fflag)
 153                         return (0);
 154                 usage();
 155         }
 156
 157         checkdot(argv);
 158         checkslash(argv);
 159         uid = geteuid();
 160
 161         (void)signal(SIGINFO, siginfo);
 162         if (*argv) {
 163                 stdin_ok = isatty(STDIN_FILENO);
 164
 165                 if (Iflag) {
 166                         if (check2(argv) == 0)
 167                                 exit (1);
 168                 }
 169                 if (rflag)
 170                         rm_tree(argv);
 171                 else
 172                         rm_file(argv);
 173         }
 174
 175         exit (eval);
 176 }
 177
 178 static void
 179 rm_tree(char **argv)
 180 {
 181         FTS *fts;
 182         FTSENT *p;
 183         int needstat;
 184         int flags;
 185         int rval;
 186
 187         /*
 188          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 189          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 190          */
 191         needstat = !uid || (!fflag && !iflag && stdin_ok);
 192
 193         /*
 194          * If the -i option is specified, the user can skip on the pre-order
 195          * visit.  The fts_number field flags skipped directories.
 196          */
 197 #define SKIPPED 1
 198
 199         flags = FTS_PHYSICAL;
 200         if (!needstat)
 201                 flags |= FTS_NOSTAT;
 202         if (Wflag)
 203                 flags |= FTS_WHITEOUT;
 204         if (xflag)
 205                 flags |= FTS_XDEV;
 206         if (!(fts = fts_open(argv, flags, NULL))) {
 207                 if (fflag && errno == ENOENT)
 208                         return;
 209                 err(1, "fts_open");
 210         }
 211         while ((p = fts_read(fts)) != NULL) {
 212                 switch (p->fts_info) {
 213                 case FTS_DNR:
 214                         if (!fflag || p->fts_errno != ENOENT) {
 215                                 warnx("%s: %s",
 216                                     p->fts_path, strerror(p->fts_errno));
 217                                 eval = 1;
 218                         }
 219                         continue;
 220                 case FTS_ERR:
 221                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 222                 case FTS_NS:
 223                         /*
 224                          * Assume that since fts_read() couldn't stat the
 225                          * file, it can't be unlinked.
 226                          */
 227                         if (!needstat)
 228                                 break;
 229                         if (!fflag || p->fts_errno != ENOENT) {
 230                                 warnx("%s: %s",
 231                                     p->fts_path, strerror(p->fts_errno));
 232                                 eval = 1;
 233                         }
 234                         continue;
 235                 case FTS_D:
 236                         /* Pre-order: give user chance to skip. */
 237                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 238                             p->fts_statp)) {
 239                                 (void)fts_set(fts, p, FTS_SKIP);
 240                                 p->fts_number = SKIPPED;
 241                         }
 242                         else if (!uid &&
 243                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 244                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 245                                  lchflags(p->fts_accpath,
 246                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 247                                 goto err;
 248                         continue;
 249                 case FTS_DP:
 250                         /* Post-order: see if user skipped. */
 251                         if (p->fts_number == SKIPPED)
 252                                 continue;
 253                         break;
 254                 default:
 255                         if (!fflag &&
 256                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 257                                 continue;
 258                 }
 259
 260                 rval = 0;
 261                 if (!uid &&
 262                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 263                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 264                         rval = lchflags(p->fts_accpath,
 265                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 266                 if (rval == 0) {
 267                         /*
 268                          * If we can't read or search the directory, may still be
 269                          * able to remove it.  Don't print out the un{read,search}able
 270                          * message unless the remove fails.
 271                          */
 272                         switch (p->fts_info) {
 273                         case FTS_DP:
 274                         case FTS_DNR:
 275                                 rval = rmdir(p->fts_accpath);
 276                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 277                                         if (rval == 0 && vflag)
 278                                                 (void)printf("%s\n",
 279                                                     p->fts_path);
 280                                         if (rval == 0 && info) {
 281                                                 info = 0;
 282                                                 (void)printf("%s\n",
 283                                                     p->fts_path);
 284                                         }
 285                                         continue;
 286                                 }
 287                                 break;
 288
 289                         case FTS_W:
 290                                 rval = undelete(p->fts_accpath);
 291                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 292                                         if (vflag)
 293                                                 (void)printf("%s\n",
 294                                                     p->fts_path);
 295                                         if (info) {
 296                                                 info = 0;
 297                                                 (void)printf("%s\n",
 298                                                     p->fts_path);
 299                                         }
 300                                         continue;
 301                                 }
 302                                 break;
 303
 304                         case FTS_NS:
 305                                 /*
 306                                  * Assume that since fts_read() couldn't stat
 307                                  * the file, it can't be unlinked.
 308                                  */
 309                                 if (fflag)
 310                                         continue;
 311                                 /* FALLTHROUGH */
 312
 313                         case FTS_F:
 314                         case FTS_NSOK:
 315                                 if (Pflag)
 316                                         if (!rm_overwrite(p->fts_accpath, p->fts_info ==
 317                                             FTS_NSOK ? NULL : p->fts_statp))
 318                                                 continue;
 319                                 /* FALLTHROUGH */
 320
 321                         default:
 322                                 rval = unlink(p->fts_accpath);
 323                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 324                                         if (rval == 0 && vflag)
 325                                                 (void)printf("%s\n",
 326                                                     p->fts_path);
 327                                         if (rval == 0 && info) {
 328                                                 info = 0;
 329                                                 (void)printf("%s\n",
 330                                                     p->fts_path);
 331                                         }
 332                                         continue;
 333                                 }
 334                         }
 335                 }
 336 err:
 337                 warn("%s", p->fts_path);
 338                 eval = 1;
 339         }
 340         if (!fflag && errno)
 341                 err(1, "fts_read");
 342         fts_close(fts);
 343 }
 344
 345 static void
 346 rm_file(char **argv)
 347 {
 348         struct stat sb;
 349         int rval;
 350         char *f;
 351
 352         /*
 353          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 354          * to remove a directory is an error, so must always stat the file.
 355          */
 356         while ((f = *argv++) != NULL) {
 357                 /* Assume if can't stat the file, can't unlink it. */
 358                 if (lstat(f, &sb)) {
 359                         if (Wflag) {
 360                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 361                         } else {
 362                                 if (!fflag || errno != ENOENT) {
 363                                         warn("%s", f);
 364                                         eval = 1;
 365                                 }
 366                                 continue;
 367                         }
 368                 } else if (Wflag) {
 369                         warnx("%s: %s", f, strerror(EEXIST));
 370                         eval = 1;
 371                         continue;
 372                 }
 373
 374                 if (S_ISDIR(sb.st_mode) && !dflag) {
 375                         warnx("%s: is a directory", f);
 376                         eval = 1;
 377                         continue;
 378                 }
 379                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 380                         continue;
 381                 rval = 0;
 382                 if (!uid && !S_ISWHT(sb.st_mode) &&
 383                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 384                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 385                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 386                 if (rval == 0) {
 387                         if (S_ISWHT(sb.st_mode))
 388                                 rval = undelete(f);
 389                         else if (S_ISDIR(sb.st_mode))
 390                                 rval = rmdir(f);
 391                         else {
 392                                 if (Pflag)
 393                                         if (!rm_overwrite(f, &sb))
 394                                                 continue;
 395                                 rval = unlink(f);
 396                         }
 397                 }
 398                 if (rval && (!fflag || errno != ENOENT)) {
 399                         warn("%s", f);
 400                         eval = 1;
 401                 }
 402                 if (vflag && rval == 0)
 403                         (void)printf("%s\n", f);
 404                 if (info && rval == 0) {
 405                         info = 0;
 406                         (void)printf("%s\n", f);
 407                 }
 408         }
 409 }
 410
 411 /*
 412  * rm_overwrite --
 413  *      Overwrite the file 3 times with varying bit patterns.
 414  *
 415  * XXX
 416  * This is a cheap way to *really* delete files.  Note that only regular
 417  * files are deleted, directories (and therefore names) will remain.
 418  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 419  * System V file system).  In a logging or COW file system, you'll have to
 420  * have kernel support.
 421  */
 422 static int
 423 rm_overwrite(const char *file, struct stat *sbp)
 424 {
 425         struct stat sb, sb2;
 426         struct statfs fsb;
 427         off_t len;
 428         int bsize, fd, wlen;
 429         char *buf = NULL;
 430
 431         fd = -1;
 432         if (sbp == NULL) {
 433                 if (lstat(file, &sb))
 434                         goto err;
 435                 sbp = &sb;
 436         }
 437         if (!S_ISREG(sbp->st_mode))
 438                 return (1);
 439         if (sbp->st_nlink > 1 && !fflag) {
 440                 warnx("%s (inode %ju): not overwritten due to multiple links",
 441                     file, (uintmax_t)sbp->st_ino);
 442                 return (0);
 443         }
 444         if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
 445                 goto err;
 446         if (fstat(fd, &sb2))
 447                 goto err;
 448         if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
 449             !S_ISREG(sb2.st_mode)) {
 450                 errno = EPERM;
 451                 goto err;
 452         }
 453         if (fstatfs(fd, &fsb) == -1)
 454                 goto err;
 455         bsize = MAX(fsb.f_iosize, 1024);
 456         if ((buf = malloc(bsize)) == NULL)
 457                 err(1, "%s: malloc", file);
 458
 459 #define PASS(byte) {                                                    \
 460         memset(buf, byte, bsize);                                       \
 461         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 462                 wlen = len < bsize ? len : bsize;                       \
 463                 if (write(fd, buf, wlen) != wlen)                       \
 464                         goto err;                                       \
 465         }                                                               \
 466 }
 467         PASS(0xff);
 468         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 469                 goto err;
 470         PASS(0x00);
 471         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 472                 goto err;
 473         PASS(0xff);
 474         if (!fsync(fd) && !close(fd)) {
 475                 free(buf);
 476                 return (1);
 477         }
 478
 479 err:    eval = 1;
 480         if (buf)
 481                 free(buf);
 482         if (fd != -1)
 483                 close(fd);
 484         warn("%s", file);
 485         return (0);
 486 }
 487
 488
 489 static int
 490 check(const char *path, const char *name, struct stat *sp)
 491 {
 492         int ch, first;
 493         char modep[15], *flagsp;
 494
 495         /* Check -i first. */
 496         if (iflag)
 497                 (void)fprintf(stderr, "remove %s? ", path);
 498         else {
 499                 /*
 500                  * If it's not a symbolic link and it's unwritable and we're
 501                  * talking to a terminal, ask.  Symbolic links are excluded
 502                  * because their permissions are meaningless.  Check stdin_ok
 503                  * first because we may not have stat'ed the file.
 504                  */
 505                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 506                     (!access(name, W_OK) &&
 507                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 508                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 509                         return (1);
 510                 strmode(sp->st_mode, modep);
 511                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 512                         err(1, "fflagstostr");
 513                 if (Pflag)
 514                         errx(1,
 515                             "%s: -P was specified, but file is not writable",
 516                             path);
 517                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 518                     modep + 1, modep[9] == ' ' ? "" : " ",
 519                     user_from_uid(sp->st_uid, 0),
 520                     group_from_gid(sp->st_gid, 0),
 521                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 522                     path);
 523                 free(flagsp);
 524         }
 525         (void)fflush(stderr);
 526
 527         first = ch = getchar();
 528         while (ch != '\n' && ch != EOF)
 529                 ch = getchar();
 530         return (first == 'y' || first == 'Y');
 531 }
 532
 533 #define ISSLASH(a)      ((a)[0] == '/' && (a)[1] == '\0')
 534 static void
 535 checkslash(char **argv)
 536 {
 537         char **t, **u;
 538         int complained;
 539
 540         complained = 0;
 541         for (t = argv; *t;) {
 542                 if (ISSLASH(*t)) {
 543                         if (!complained++)
 544                                 warnx("\"/\" may not be removed");
 545                         eval = 1;
 546                         for (u = t; u[0] != NULL; ++u)
 547                                 u[0] = u[1];
 548                 } else {
 549                         ++t;
 550                 }
 551         }
 552 }
 553
 554 static int
 555 check2(char **argv)
 556 {
 557         struct stat st;
 558         int first;
 559         int ch;
 560         int fcount = 0;
 561         int dcount = 0;
 562         int i;
 563         const char *dname = NULL;
 564
 565         for (i = 0; argv[i]; ++i) {
 566                 if (lstat(argv[i], &st) == 0) {
 567                         if (S_ISDIR(st.st_mode)) {
 568                                 ++dcount;
 569                                 dname = argv[i];    /* only used if 1 dir */
 570                         } else {
 571                                 ++fcount;
 572                         }
 573                 }
 574         }
 575         first = 0;
 576         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 577                 if (dcount && rflag) {
 578                         fprintf(stderr, "recursively remove");
 579                         if (dcount == 1)
 580                                 fprintf(stderr, " %s", dname);
 581                         else
 582                                 fprintf(stderr, " %d dirs", dcount);
 583                         if (fcount == 1)
 584                                 fprintf(stderr, " and 1 file");
 585                         else if (fcount > 1)
 586                                 fprintf(stderr, " and %d files", fcount);
 587                 } else if (dcount + fcount > 3) {
 588                         fprintf(stderr, "remove %d files", dcount + fcount);
 589                 } else {
 590                         return(1);
 591                 }
 592                 fprintf(stderr, "? ");
 593                 fflush(stderr);
 594
 595                 first = ch = getchar();
 596                 while (ch != '\n' && ch != EOF)
 597                         ch = getchar();
 598                 if (ch == EOF)
 599                         break;
 600         }
 601         return (first == 'y' || first == 'Y');
 602 }
 603
 604 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 605 static void
 606 checkdot(char **argv)
 607 {
 608         char *p, **save, **t;
 609         int complained;
 610
 611         complained = 0;
 612         for (t = argv; *t;) {
 613                 if ((p = strrchr(*t, '/')) != NULL)
 614                         ++p;
 615                 else
 616                         p = *t;
 617                 if (ISDOT(p)) {
 618                         if (!complained++)
 619                                 warnx("\".\" and \"..\" may not be removed");
 620                         eval = 1;
 621                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 622                                 continue;
 623                         t = save;
 624                 } else
 625                         ++t;
 626         }
 627 }
 628
 629 static void
 630 usage(void)
 631 {
 632
 633         (void)fprintf(stderr, "%s\n%s\n",
 634             "usage: rm [-f | -i] [-dIPRrvWx] file ...",
 635             "       unlink file");
 636         exit(EX_USAGE);
 637 }
 638
 639 static void
 640 siginfo(int sig __unused)
 641 {
 642
 643         info = 1;
 644 }