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         if (getenv("POSIXLY_CORRECT") == NULL)
 159                 checkslash(argv);
 160         uid = geteuid();
 161
 162         (void)signal(SIGINFO, siginfo);
 163         if (*argv) {
 164                 stdin_ok = isatty(STDIN_FILENO);
 165
 166                 if (Iflag) {
 167                         if (check2(argv) == 0)
 168                                 exit (1);
 169                 }
 170                 if (rflag)
 171                         rm_tree(argv);
 172                 else
 173                         rm_file(argv);
 174         }
 175
 176         exit (eval);
 177 }
 178
 179 static void
 180 rm_tree(char **argv)
 181 {
 182         FTS *fts;
 183         FTSENT *p;
 184         int needstat;
 185         int flags;
 186         int rval;
 187
 188         /*
 189          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 190          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 191          */
 192         needstat = !uid || (!fflag && !iflag && stdin_ok);
 193
 194         /*
 195          * If the -i option is specified, the user can skip on the pre-order
 196          * visit.  The fts_number field flags skipped directories.
 197          */
 198 #define SKIPPED 1
 199
 200         flags = FTS_PHYSICAL;
 201         if (!needstat)
 202                 flags |= FTS_NOSTAT;
 203         if (Wflag)
 204                 flags |= FTS_WHITEOUT;
 205         if (xflag)
 206                 flags |= FTS_XDEV;
 207         if (!(fts = fts_open(argv, flags, NULL))) {
 208                 if (fflag && errno == ENOENT)
 209                         return;
 210                 err(1, "fts_open");
 211         }
 212         while ((p = fts_read(fts)) != NULL) {
 213                 switch (p->fts_info) {
 214                 case FTS_DNR:
 215                         if (!fflag || p->fts_errno != ENOENT) {
 216                                 warnx("%s: %s",
 217                                     p->fts_path, strerror(p->fts_errno));
 218                                 eval = 1;
 219                         }
 220                         continue;
 221                 case FTS_ERR:
 222                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 223                 case FTS_NS:
 224                         /*
 225                          * Assume that since fts_read() couldn't stat the
 226                          * file, it can't be unlinked.
 227                          */
 228                         if (!needstat)
 229                                 break;
 230                         if (!fflag || p->fts_errno != ENOENT) {
 231                                 warnx("%s: %s",
 232                                     p->fts_path, strerror(p->fts_errno));
 233                                 eval = 1;
 234                         }
 235                         continue;
 236                 case FTS_D:
 237                         /* Pre-order: give user chance to skip. */
 238                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 239                             p->fts_statp)) {
 240                                 (void)fts_set(fts, p, FTS_SKIP);
 241                                 p->fts_number = SKIPPED;
 242                         }
 243                         else if (!uid &&
 244                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 245                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 246                                  lchflags(p->fts_accpath,
 247                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 248                                 goto err;
 249                         continue;
 250                 case FTS_DP:
 251                         /* Post-order: see if user skipped. */
 252                         if (p->fts_number == SKIPPED)
 253                                 continue;
 254                         break;
 255                 default:
 256                         if (!fflag &&
 257                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 258                                 continue;
 259                 }
 260
 261                 rval = 0;
 262                 if (!uid &&
 263                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 264                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 265                         rval = lchflags(p->fts_accpath,
 266                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 267                 if (rval == 0) {
 268                         /*
 269                          * If we can't read or search the directory, may still be
 270                          * able to remove it.  Don't print out the un{read,search}able
 271                          * message unless the remove fails.
 272                          */
 273                         switch (p->fts_info) {
 274                         case FTS_DP:
 275                         case FTS_DNR:
 276                                 rval = rmdir(p->fts_accpath);
 277                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 278                                         if (rval == 0 && vflag)
 279                                                 (void)printf("%s\n",
 280                                                     p->fts_path);
 281                                         if (rval == 0 && info) {
 282                                                 info = 0;
 283                                                 (void)printf("%s\n",
 284                                                     p->fts_path);
 285                                         }
 286                                         continue;
 287                                 }
 288                                 break;
 289
 290                         case FTS_W:
 291                                 rval = undelete(p->fts_accpath);
 292                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 293                                         if (vflag)
 294                                                 (void)printf("%s\n",
 295                                                     p->fts_path);
 296                                         if (info) {
 297                                                 info = 0;
 298                                                 (void)printf("%s\n",
 299                                                     p->fts_path);
 300                                         }
 301                                         continue;
 302                                 }
 303                                 break;
 304
 305                         case FTS_NS:
 306                                 /*
 307                                  * Assume that since fts_read() couldn't stat
 308                                  * the file, it can't be unlinked.
 309                                  */
 310                                 if (fflag)
 311                                         continue;
 312                                 /* FALLTHROUGH */
 313
 314                         case FTS_F:
 315                         case FTS_NSOK:
 316                                 if (Pflag)
 317                                         if (!rm_overwrite(p->fts_accpath, p->fts_info ==
 318                                             FTS_NSOK ? NULL : p->fts_statp))
 319                                                 continue;
 320                                 /* FALLTHROUGH */
 321
 322                         default:
 323                                 rval = unlink(p->fts_accpath);
 324                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 325                                         if (rval == 0 && vflag)
 326                                                 (void)printf("%s\n",
 327                                                     p->fts_path);
 328                                         if (rval == 0 && info) {
 329                                                 info = 0;
 330                                                 (void)printf("%s\n",
 331                                                     p->fts_path);
 332                                         }
 333                                         continue;
 334                                 }
 335                         }
 336                 }
 337 err:
 338                 warn("%s", p->fts_path);
 339                 eval = 1;
 340         }
 341         if (!fflag && errno)
 342                 err(1, "fts_read");
 343         fts_close(fts);
 344 }
 345
 346 static void
 347 rm_file(char **argv)
 348 {
 349         struct stat sb;
 350         int rval;
 351         char *f;
 352
 353         /*
 354          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 355          * to remove a directory is an error, so must always stat the file.
 356          */
 357         while ((f = *argv++) != NULL) {
 358                 /* Assume if can't stat the file, can't unlink it. */
 359                 if (lstat(f, &sb)) {
 360                         if (Wflag) {
 361                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 362                         } else {
 363                                 if (!fflag || errno != ENOENT) {
 364                                         warn("%s", f);
 365                                         eval = 1;
 366                                 }
 367                                 continue;
 368                         }
 369                 } else if (Wflag) {
 370                         warnx("%s: %s", f, strerror(EEXIST));
 371                         eval = 1;
 372                         continue;
 373                 }
 374
 375                 if (S_ISDIR(sb.st_mode) && !dflag) {
 376                         warnx("%s: is a directory", f);
 377                         eval = 1;
 378                         continue;
 379                 }
 380                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 381                         continue;
 382                 rval = 0;
 383                 if (!uid && !S_ISWHT(sb.st_mode) &&
 384                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 385                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 386                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 387                 if (rval == 0) {
 388                         if (S_ISWHT(sb.st_mode))
 389                                 rval = undelete(f);
 390                         else if (S_ISDIR(sb.st_mode))
 391                                 rval = rmdir(f);
 392                         else {
 393                                 if (Pflag)
 394                                         if (!rm_overwrite(f, &sb))
 395                                                 continue;
 396                                 rval = unlink(f);
 397                         }
 398                 }
 399                 if (rval && (!fflag || errno != ENOENT)) {
 400                         warn("%s", f);
 401                         eval = 1;
 402                 }
 403                 if (vflag && rval == 0)
 404                         (void)printf("%s\n", f);
 405                 if (info && rval == 0) {
 406                         info = 0;
 407                         (void)printf("%s\n", f);
 408                 }
 409         }
 410 }
 411
 412 /*
 413  * rm_overwrite --
 414  *      Overwrite the file 3 times with varying bit patterns.
 415  *
 416  * XXX
 417  * This is a cheap way to *really* delete files.  Note that only regular
 418  * files are deleted, directories (and therefore names) will remain.
 419  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 420  * System V file system).  In a logging or COW file system, you'll have to
 421  * have kernel support.
 422  */
 423 static int
 424 rm_overwrite(const char *file, struct stat *sbp)
 425 {
 426         struct stat sb, sb2;
 427         struct statfs fsb;
 428         off_t len;
 429         int bsize, fd, wlen;
 430         char *buf = NULL;
 431
 432         fd = -1;
 433         if (sbp == NULL) {
 434                 if (lstat(file, &sb))
 435                         goto err;
 436                 sbp = &sb;
 437         }
 438         if (!S_ISREG(sbp->st_mode))
 439                 return (1);
 440         if (sbp->st_nlink > 1 && !fflag) {
 441                 warnx("%s (inode %ju): not overwritten due to multiple links",
 442                     file, (uintmax_t)sbp->st_ino);
 443                 return (0);
 444         }
 445         if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
 446                 goto err;
 447         if (fstat(fd, &sb2))
 448                 goto err;
 449         if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
 450             !S_ISREG(sb2.st_mode)) {
 451                 errno = EPERM;
 452                 goto err;
 453         }
 454         if (fstatfs(fd, &fsb) == -1)
 455                 goto err;
 456         bsize = MAX(fsb.f_iosize, 1024);
 457         if ((buf = malloc(bsize)) == NULL)
 458                 err(1, "%s: malloc", file);
 459
 460 #define PASS(byte) {                                                    \
 461         memset(buf, byte, bsize);                                       \
 462         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 463                 wlen = len < bsize ? len : bsize;                       \
 464                 if (write(fd, buf, wlen) != wlen)                       \
 465                         goto err;                                       \
 466         }                                                               \
 467 }
 468         PASS(0xff);
 469         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 470                 goto err;
 471         PASS(0x00);
 472         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 473                 goto err;
 474         PASS(0xff);
 475         if (!fsync(fd) && !close(fd)) {
 476                 free(buf);
 477                 return (1);
 478         }
 479
 480 err:    eval = 1;
 481         if (buf)
 482                 free(buf);
 483         if (fd != -1)
 484                 close(fd);
 485         warn("%s", file);
 486         return (0);
 487 }
 488
 489
 490 static int
 491 check(const char *path, const char *name, struct stat *sp)
 492 {
 493         int ch, first;
 494         char modep[15], *flagsp;
 495
 496         /* Check -i first. */
 497         if (iflag)
 498                 (void)fprintf(stderr, "remove %s? ", path);
 499         else {
 500                 /*
 501                  * If it's not a symbolic link and it's unwritable and we're
 502                  * talking to a terminal, ask.  Symbolic links are excluded
 503                  * because their permissions are meaningless.  Check stdin_ok
 504                  * first because we may not have stat'ed the file.
 505                  */
 506                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 507                     (!access(name, W_OK) &&
 508                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 509                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 510                         return (1);
 511                 strmode(sp->st_mode, modep);
 512                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 513                         err(1, "fflagstostr");
 514                 if (Pflag)
 515                         errx(1,
 516                             "%s: -P was specified, but file is not writable",
 517                             path);
 518                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 519                     modep + 1, modep[9] == ' ' ? "" : " ",
 520                     user_from_uid(sp->st_uid, 0),
 521                     group_from_gid(sp->st_gid, 0),
 522                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 523                     path);
 524                 free(flagsp);
 525         }
 526         (void)fflush(stderr);
 527
 528         first = ch = getchar();
 529         while (ch != '\n' && ch != EOF)
 530                 ch = getchar();
 531         return (first == 'y' || first == 'Y');
 532 }
 533
 534 #define ISSLASH(a)      ((a)[0] == '/' && (a)[1] == '\0')
 535 static void
 536 checkslash(char **argv)
 537 {
 538         char **t, **u;
 539         int complained;
 540
 541         complained = 0;
 542         for (t = argv; *t;) {
 543                 if (ISSLASH(*t)) {
 544                         if (!complained++)
 545                                 warnx("\"/\" may not be removed");
 546                         eval = 1;
 547                         for (u = t; u[0] != NULL; ++u)
 548                                 u[0] = u[1];
 549                 } else {
 550                         ++t;
 551                 }
 552         }
 553 }
 554
 555 static int
 556 check2(char **argv)
 557 {
 558         struct stat st;
 559         int first;
 560         int ch;
 561         int fcount = 0;
 562         int dcount = 0;
 563         int i;
 564         const char *dname = NULL;
 565
 566         for (i = 0; argv[i]; ++i) {
 567                 if (lstat(argv[i], &st) == 0) {
 568                         if (S_ISDIR(st.st_mode)) {
 569                                 ++dcount;
 570                                 dname = argv[i];    /* only used if 1 dir */
 571                         } else {
 572                                 ++fcount;
 573                         }
 574                 }
 575         }
 576         first = 0;
 577         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 578                 if (dcount && rflag) {
 579                         fprintf(stderr, "recursively remove");
 580                         if (dcount == 1)
 581                                 fprintf(stderr, " %s", dname);
 582                         else
 583                                 fprintf(stderr, " %d dirs", dcount);
 584                         if (fcount == 1)
 585                                 fprintf(stderr, " and 1 file");
 586                         else if (fcount > 1)
 587                                 fprintf(stderr, " and %d files", fcount);
 588                 } else if (dcount + fcount > 3) {
 589                         fprintf(stderr, "remove %d files", dcount + fcount);
 590                 } else {
 591                         return(1);
 592                 }
 593                 fprintf(stderr, "? ");
 594                 fflush(stderr);
 595
 596                 first = ch = getchar();
 597                 while (ch != '\n' && ch != EOF)
 598                         ch = getchar();
 599                 if (ch == EOF)
 600                         break;
 601         }
 602         return (first == 'y' || first == 'Y');
 603 }
 604
 605 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 606 static void
 607 checkdot(char **argv)
 608 {
 609         char *p, **save, **t;
 610         int complained;
 611
 612         complained = 0;
 613         for (t = argv; *t;) {
 614                 if ((p = strrchr(*t, '/')) != NULL)
 615                         ++p;
 616                 else
 617                         p = *t;
 618                 if (ISDOT(p)) {
 619                         if (!complained++)
 620                                 warnx("\".\" and \"..\" may not be removed");
 621                         eval = 1;
 622                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 623                                 continue;
 624                         t = save;
 625                 } else
 626                         ++t;
 627         }
 628 }
 629
 630 static void
 631 usage(void)
 632 {
 633
 634         (void)fprintf(stderr, "%s\n%s\n",
 635             "usage: rm [-f | -i] [-dIPRrvWx] file ...",
 636             "       unlink file");
 637         exit(EX_USAGE);
 638 }
 639
 640 static void
 641 siginfo(int sig __unused)
 642 {
 643
 644         info = 1;
 645 }