bin/rm/rm.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if 0
  33 #ifndef lint
  34 static const char copyright[] =
  35 "@(#) Copyright (c) 1990, 1993, 1994\n\
  36         The Regents of the University of California.  All rights reserved.\n";
  37 #endif /* not lint */
  38
  39 #ifndef lint
  40 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  41 #endif /* not lint */
  42 #endif
  43 #include <sys/cdefs.h>
  44 __FBSDID("$FreeBSD$");
  45
  46 #include <sys/stat.h>
  47 #include <sys/param.h>
  48 #include <sys/mount.h>
  49
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <fcntl.h>
  53 #include <fts.h>
  54 #include <grp.h>
  55 #include <locale.h>
  56 #include <pwd.h>
  57 #include <stdint.h>
  58 #include <stdio.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include <sysexits.h>
  62 #include <unistd.h>
  63
  64 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  65 static int rflag, Iflag, xflag;
  66 static uid_t uid;
  67 static volatile sig_atomic_t info;
  68
  69 static int      check(const char *, const char *, struct stat *);
  70 static int      check2(char **);
  71 static void     checkdot(char **);
  72 static void     checkslash(char **);
  73 static void     rm_file(char **);
  74 static int      rm_overwrite(const char *, struct stat *);
  75 static void     rm_tree(char **);
  76 static void siginfo(int __unused);
  77 static void     usage(void);
  78
  79 /*
  80  * rm --
  81  *      This rm is different from historic rm's, but is expected to match
  82  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  83  *      has two specific effects now, ignore non-existent files and force
  84  *      file removal.
  85  */
  86 int
  87 main(int argc, char *argv[])
  88 {
  89         int ch;
  90         char *p;
  91
  92         (void)setlocale(LC_ALL, "");
  93
  94         /*
  95          * Test for the special case where the utility is called as
  96          * "unlink", for which the functionality provided is greatly
  97          * simplified.
  98          */
  99         if ((p = strrchr(argv[0], '/')) == NULL)
 100                 p = argv[0];
 101         else
 102                 ++p;
 103         if (strcmp(p, "unlink") == 0) {
 104                 while (getopt(argc, argv, "") != -1)
 105                         usage();
 106                 argc -= optind;
 107                 argv += optind;
 108                 if (argc != 1)
 109                         usage();
 110                 rm_file(&argv[0]);
 111                 exit(eval);
 112         }
 113
 114         Pflag = rflag = xflag = 0;
 115         while ((ch = getopt(argc, argv, "dfiIPRrvWx")) != -1)
 116                 switch(ch) {
 117                 case 'd':
 118                         dflag = 1;
 119                         break;
 120                 case 'f':
 121                         fflag = 1;
 122                         iflag = 0;
 123                         break;
 124                 case 'i':
 125                         fflag = 0;
 126                         iflag = 1;
 127                         break;
 128                 case 'I':
 129                         Iflag = 1;
 130                         break;
 131                 case 'P':
 132                         Pflag = 1;
 133                         break;
 134                 case 'R':
 135                 case 'r':                       /* Compatibility. */
 136                         rflag = 1;
 137                         break;
 138                 case 'v':
 139                         vflag = 1;
 140                         break;
 141                 case 'W':
 142                         Wflag = 1;
 143                         break;
 144                 case 'x':
 145                         xflag = 1;
 146                         break;
 147                 default:
 148                         usage();
 149                 }
 150         argc -= optind;
 151         argv += optind;
 152
 153         if (argc < 1) {
 154                 if (fflag)
 155                         return (0);
 156                 usage();
 157         }
 158
 159         checkdot(argv);
 160         checkslash(argv);
 161         uid = geteuid();
 162
 163         (void)signal(SIGINFO, siginfo);
 164         if (*argv) {
 165                 stdin_ok = isatty(STDIN_FILENO);
 166
 167                 if (Iflag) {
 168                         if (check2(argv) == 0)
 169                                 exit (1);
 170                 }
 171                 if (rflag)
 172                         rm_tree(argv);
 173                 else
 174                         rm_file(argv);
 175         }
 176
 177         exit (eval);
 178 }
 179
 180 static void
 181 rm_tree(char **argv)
 182 {
 183         FTS *fts;
 184         FTSENT *p;
 185         int needstat;
 186         int flags;
 187         int rval;
 188
 189         /*
 190          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 191          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 192          */
 193         needstat = !uid || (!fflag && !iflag && stdin_ok);
 194
 195         /*
 196          * If the -i option is specified, the user can skip on the pre-order
 197          * visit.  The fts_number field flags skipped directories.
 198          */
 199 #define SKIPPED 1
 200
 201         flags = FTS_PHYSICAL;
 202         if (!needstat)
 203                 flags |= FTS_NOSTAT;
 204         if (Wflag)
 205                 flags |= FTS_WHITEOUT;
 206         if (xflag)
 207                 flags |= FTS_XDEV;
 208         if (!(fts = fts_open(argv, flags, NULL))) {
 209                 if (fflag && errno == ENOENT)
 210                         return;
 211                 err(1, "fts_open");
 212         }
 213         while ((p = fts_read(fts)) != NULL) {
 214                 switch (p->fts_info) {
 215                 case FTS_DNR:
 216                         if (!fflag || p->fts_errno != ENOENT) {
 217                                 warnx("%s: %s",
 218                                     p->fts_path, strerror(p->fts_errno));
 219                                 eval = 1;
 220                         }
 221                         continue;
 222                 case FTS_ERR:
 223                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 224                 case FTS_NS:
 225                         /*
 226                          * Assume that since fts_read() couldn't stat the
 227                          * file, it can't be unlinked.
 228                          */
 229                         if (!needstat)
 230                                 break;
 231                         if (!fflag || p->fts_errno != ENOENT) {
 232                                 warnx("%s: %s",
 233                                     p->fts_path, strerror(p->fts_errno));
 234                                 eval = 1;
 235                         }
 236                         continue;
 237                 case FTS_D:
 238                         /* Pre-order: give user chance to skip. */
 239                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 240                             p->fts_statp)) {
 241                                 (void)fts_set(fts, p, FTS_SKIP);
 242                                 p->fts_number = SKIPPED;
 243                         }
 244                         else if (!uid &&
 245                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 246                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 247                                  lchflags(p->fts_accpath,
 248                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 249                                 goto err;
 250                         continue;
 251                 case FTS_DP:
 252                         /* Post-order: see if user skipped. */
 253                         if (p->fts_number == SKIPPED)
 254                                 continue;
 255                         break;
 256                 default:
 257                         if (!fflag &&
 258                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 259                                 continue;
 260                 }
 261
 262                 rval = 0;
 263                 if (!uid &&
 264                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 265                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 266                         rval = lchflags(p->fts_accpath,
 267                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 268                 if (rval == 0) {
 269                         /*
 270                          * If we can't read or search the directory, may still be
 271                          * able to remove it.  Don't print out the un{read,search}able
 272                          * message unless the remove fails.
 273                          */
 274                         switch (p->fts_info) {
 275                         case FTS_DP:
 276                         case FTS_DNR:
 277                                 rval = rmdir(p->fts_accpath);
 278                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 279                                         if (rval == 0 && vflag)
 280                                                 (void)printf("%s\n",
 281                                                     p->fts_path);
 282                                         if (rval == 0 && info) {
 283                                                 info = 0;
 284                                                 (void)printf("%s\n",
 285                                                     p->fts_path);
 286                                         }
 287                                         continue;
 288                                 }
 289                                 break;
 290
 291                         case FTS_W:
 292                                 rval = undelete(p->fts_accpath);
 293                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 294                                         if (vflag)
 295                                                 (void)printf("%s\n",
 296                                                     p->fts_path);
 297                                         if (info) {
 298                                                 info = 0;
 299                                                 (void)printf("%s\n",
 300                                                     p->fts_path);
 301                                         }
 302                                         continue;
 303                                 }
 304                                 break;
 305
 306                         case FTS_NS:
 307                                 /*
 308                                  * Assume that since fts_read() couldn't stat
 309                                  * the file, it can't be unlinked.
 310                                  */
 311                                 if (fflag)
 312                                         continue;
 313                                 /* FALLTHROUGH */
 314
 315                         case FTS_F:
 316                         case FTS_NSOK:
 317                                 if (Pflag)
 318                                         if (!rm_overwrite(p->fts_accpath, p->fts_info ==
 319                                             FTS_NSOK ? NULL : p->fts_statp))
 320                                                 continue;
 321                                 /* FALLTHROUGH */
 322
 323                         default:
 324                                 rval = unlink(p->fts_accpath);
 325                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 326                                         if (rval == 0 && vflag)
 327                                                 (void)printf("%s\n",
 328                                                     p->fts_path);
 329                                         if (rval == 0 && info) {
 330                                                 info = 0;
 331                                                 (void)printf("%s\n",
 332                                                     p->fts_path);
 333                                         }
 334                                         continue;
 335                                 }
 336                         }
 337                 }
 338 err:
 339                 warn("%s", p->fts_path);
 340                 eval = 1;
 341         }
 342         if (!fflag && errno)
 343                 err(1, "fts_read");
 344         fts_close(fts);
 345 }
 346
 347 static void
 348 rm_file(char **argv)
 349 {
 350         struct stat sb;
 351         int rval;
 352         char *f;
 353
 354         /*
 355          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 356          * to remove a directory is an error, so must always stat the file.
 357          */
 358         while ((f = *argv++) != NULL) {
 359                 /* Assume if can't stat the file, can't unlink it. */
 360                 if (lstat(f, &sb)) {
 361                         if (Wflag) {
 362                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 363                         } else {
 364                                 if (!fflag || errno != ENOENT) {
 365                                         warn("%s", f);
 366                                         eval = 1;
 367                                 }
 368                                 continue;
 369                         }
 370                 } else if (Wflag) {
 371                         warnx("%s: %s", f, strerror(EEXIST));
 372                         eval = 1;
 373                         continue;
 374                 }
 375
 376                 if (S_ISDIR(sb.st_mode) && !dflag) {
 377                         warnx("%s: is a directory", f);
 378                         eval = 1;
 379                         continue;
 380                 }
 381                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 382                         continue;
 383                 rval = 0;
 384                 if (!uid && !S_ISWHT(sb.st_mode) &&
 385                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 386                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 387                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 388                 if (rval == 0) {
 389                         if (S_ISWHT(sb.st_mode))
 390                                 rval = undelete(f);
 391                         else if (S_ISDIR(sb.st_mode))
 392                                 rval = rmdir(f);
 393                         else {
 394                                 if (Pflag)
 395                                         if (!rm_overwrite(f, &sb))
 396                                                 continue;
 397                                 rval = unlink(f);
 398                         }
 399                 }
 400                 if (rval && (!fflag || errno != ENOENT)) {
 401                         warn("%s", f);
 402                         eval = 1;
 403                 }
 404                 if (vflag && rval == 0)
 405                         (void)printf("%s\n", f);
 406                 if (info && rval == 0) {
 407                         info = 0;
 408                         (void)printf("%s\n", f);
 409                 }
 410         }
 411 }
 412
 413 /*
 414  * rm_overwrite --
 415  *      Overwrite the file 3 times with varying bit patterns.
 416  *
 417  * XXX
 418  * This is a cheap way to *really* delete files.  Note that only regular
 419  * files are deleted, directories (and therefore names) will remain.
 420  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 421  * System V file system).  In a logging or COW file system, you'll have to
 422  * have kernel support.
 423  */
 424 static int
 425 rm_overwrite(const char *file, struct stat *sbp)
 426 {
 427         struct stat sb, sb2;
 428         struct statfs fsb;
 429         off_t len;
 430         int bsize, fd, wlen;
 431         char *buf = NULL;
 432
 433         fd = -1;
 434         if (sbp == NULL) {
 435                 if (lstat(file, &sb))
 436                         goto err;
 437                 sbp = &sb;
 438         }
 439         if (!S_ISREG(sbp->st_mode))
 440                 return (1);
 441         if (sbp->st_nlink > 1 && !fflag) {
 442                 warnx("%s (inode %ju): not overwritten due to multiple links",
 443                     file, (uintmax_t)sbp->st_ino);
 444                 return (0);
 445         }
 446         if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
 447                 goto err;
 448         if (fstat(fd, &sb2))
 449                 goto err;
 450         if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
 451             !S_ISREG(sb2.st_mode)) {
 452                 errno = EPERM;
 453                 goto err;
 454         }
 455         if (fstatfs(fd, &fsb) == -1)
 456                 goto err;
 457         bsize = MAX(fsb.f_iosize, 1024);
 458         if ((buf = malloc(bsize)) == NULL)
 459                 err(1, "%s: malloc", file);
 460
 461 #define PASS(byte) {                                                    \
 462         memset(buf, byte, bsize);                                       \
 463         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 464                 wlen = len < bsize ? len : bsize;                       \
 465                 if (write(fd, buf, wlen) != wlen)                       \
 466                         goto err;                                       \
 467         }                                                               \
 468 }
 469         PASS(0xff);
 470         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 471                 goto err;
 472         PASS(0x00);
 473         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 474                 goto err;
 475         PASS(0xff);
 476         if (!fsync(fd) && !close(fd)) {
 477                 free(buf);
 478                 return (1);
 479         }
 480
 481 err:    eval = 1;
 482         if (buf)
 483                 free(buf);
 484         if (fd != -1)
 485                 close(fd);
 486         warn("%s", file);
 487         return (0);
 488 }
 489
 490
 491 static int
 492 check(const char *path, const char *name, struct stat *sp)
 493 {
 494         int ch, first;
 495         char modep[15], *flagsp;
 496
 497         /* Check -i first. */
 498         if (iflag)
 499                 (void)fprintf(stderr, "remove %s? ", path);
 500         else {
 501                 /*
 502                  * If it's not a symbolic link and it's unwritable and we're
 503                  * talking to a terminal, ask.  Symbolic links are excluded
 504                  * because their permissions are meaningless.  Check stdin_ok
 505                  * first because we may not have stat'ed the file.
 506                  */
 507                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 508                     (!access(name, W_OK) &&
 509                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 510                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 511                         return (1);
 512                 strmode(sp->st_mode, modep);
 513                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 514                         err(1, "fflagstostr");
 515                 if (Pflag)
 516                         errx(1,
 517                             "%s: -P was specified, but file is not writable",
 518                             path);
 519                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 520                     modep + 1, modep[10] == ' ' ? "" : " ",
 521                     user_from_uid(sp->st_uid, 0),
 522                     group_from_gid(sp->st_gid, 0),
 523                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 524                     path);
 525                 free(flagsp);
 526         }
 527         (void)fflush(stderr);
 528
 529         first = ch = getchar();
 530         while (ch != '\n' && ch != EOF)
 531                 ch = getchar();
 532         return (first == 'y' || first == 'Y');
 533 }
 534
 535 #define ISSLASH(a)      ((a)[0] == '/' && (a)[1] == '\0')
 536 static void
 537 checkslash(char **argv)
 538 {
 539         char **t, **u;
 540         int complained;
 541
 542         complained = 0;
 543         for (t = argv; *t;) {
 544                 if (ISSLASH(*t)) {
 545                         if (!complained++)
 546                                 warnx("\"/\" may not be removed");
 547                         eval = 1;
 548                         for (u = t; u[0] != NULL; ++u)
 549                                 u[0] = u[1];
 550                 } else {
 551                         ++t;
 552                 }
 553         }
 554 }
 555
 556 static int
 557 check2(char **argv)
 558 {
 559         struct stat st;
 560         int first;
 561         int ch;
 562         int fcount = 0;
 563         int dcount = 0;
 564         int i;
 565         const char *dname = NULL;
 566
 567         for (i = 0; argv[i]; ++i) {
 568                 if (lstat(argv[i], &st) == 0) {
 569                         if (S_ISDIR(st.st_mode)) {
 570                                 ++dcount;
 571                                 dname = argv[i];    /* only used if 1 dir */
 572                         } else {
 573                                 ++fcount;
 574                         }
 575                 }
 576         }
 577         first = 0;
 578         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 579                 if (dcount && rflag) {
 580                         fprintf(stderr, "recursively remove");
 581                         if (dcount == 1)
 582                                 fprintf(stderr, " %s", dname);
 583                         else
 584                                 fprintf(stderr, " %d dirs", dcount);
 585                         if (fcount == 1)
 586                                 fprintf(stderr, " and 1 file");
 587                         else if (fcount > 1)
 588                                 fprintf(stderr, " and %d files", fcount);
 589                 } else if (dcount + fcount > 3) {
 590                         fprintf(stderr, "remove %d files", dcount + fcount);
 591                 } else {
 592                         return(1);
 593                 }
 594                 fprintf(stderr, "? ");
 595                 fflush(stderr);
 596
 597                 first = ch = getchar();
 598                 while (ch != '\n' && ch != EOF)
 599                         ch = getchar();
 600                 if (ch == EOF)
 601                         break;
 602         }
 603         return (first == 'y' || first == 'Y');
 604 }
 605
 606 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 607 static void
 608 checkdot(char **argv)
 609 {
 610         char *p, **save, **t;
 611         int complained;
 612
 613         complained = 0;
 614         for (t = argv; *t;) {
 615                 if ((p = strrchr(*t, '/')) != NULL)
 616                         ++p;
 617                 else
 618                         p = *t;
 619                 if (ISDOT(p)) {
 620                         if (!complained++)
 621                                 warnx("\".\" and \"..\" may not be removed");
 622                         eval = 1;
 623                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 624                                 continue;
 625                         t = save;
 626                 } else
 627                         ++t;
 628         }
 629 }
 630
 631 static void
 632 usage(void)
 633 {
 634
 635         (void)fprintf(stderr, "%s\n%s\n",
 636             "usage: rm [-f | -i] [-dIPRrvWx] file ...",
 637             "       unlink file");
 638         exit(EX_USAGE);
 639 }
 640
 641 static void
 642 siginfo(int sig __unused)
 643 {
 644
 645         info = 1;
 646 }