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