bin/rm/rm.c

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