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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1990, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)rm.c     8.5 (Berkeley) 4/18/94
  35  * $FreeBSD: src/bin/rm/rm.c,v 1.29.2.5 2002/07/12 07:25:48 tjr Exp $
  36  * $DragonFly: src/bin/rm/rm.c,v 1.19 2006/11/12 00:51:47 swildner Exp $
  37  */
  38
  39 #include <sys/stat.h>
  40 #include <sys/param.h>
  41 #include <sys/mount.h>
  42 #include <sys/ioctl.h>
  43
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <fts.h>
  48 #include <signal.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <sysexits.h>
  53 #include <unistd.h>
  54
  55 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  56 static int rflag, Iflag;
  57 static uid_t uid;
  58 volatile sig_atomic_t info;
  59
  60 static int      check(const char *, const char *, struct stat *);
  61 static int      check2(char **);
  62 static void     checkdot(char **);
  63 static void     rm_file(char **);
  64 static int      rm_overwrite(const char *, struct stat *);
  65 static void     rm_tree(char **);
  66 static void     siginfo(int);
  67 static void     usage(void);
  68
  69 /*
  70  * rm --
  71  *      This rm is different from historic rm's, but is expected to match
  72  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  73  *      has two specific effects now, ignore non-existent files and force
  74  *      file removal.
  75  */
  76 int
  77 main(int argc, char *argv[])
  78 {
  79         int ch;
  80         const char *p;
  81         pid_t tty_pgrp;
  82
  83         /*
  84          * Test for the special case where the utility is called as
  85          * "unlink", for which the functionality provided is greatly
  86          * simplified.
  87          */
  88         if ((p = strrchr(argv[0], '/')) == NULL)
  89                 p = argv[0];
  90         else
  91                 ++p;
  92         if (strcmp(p, "unlink") == 0) {
  93                 while (getopt(argc, argv, "") != -1)
  94                         usage();
  95                 argc -= optind;
  96                 argv += optind;
  97                 if (argc != 1)
  98                         usage();
  99                 rm_file(&argv[0]);
 100                 exit(eval);
 101         }
 102
 103         Pflag = rflag = 0;
 104         while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1) {
 105                 switch(ch) {
 106                 case 'd':
 107                         dflag = 1;
 108                         break;
 109                 case 'f':
 110                         fflag = 1;
 111                         iflag = 0;
 112                         break;
 113                 case 'i':
 114                         fflag = 0;
 115                         iflag = 1;
 116                         break;
 117                 case 'I':
 118                         /*
 119                          * The -I flag is intended to be generally aliasable
 120                          * in /etc/csh.cshrc.  We apply it only to foreground
 121                          * processes.
 122                          */
 123                         if (ioctl(0, TIOCGPGRP, &tty_pgrp) == 0) {
 124                                 if (tty_pgrp == getpgrp())
 125                                         Iflag = 1;
 126                         }
 127                         break;
 128                 case 'P':
 129                         Pflag = 1;
 130                         break;
 131                 case 'R':
 132                 case 'r':                       /* Compatibility. */
 133                         rflag = 1;
 134                         break;
 135                 case 'v':
 136                         vflag = 1;
 137                         break;
 138                 case 'W':
 139                         Wflag = 1;
 140                         break;
 141                 default:
 142                         usage();
 143                 }
 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         uid = geteuid();
 156
 157         signal(SIGINFO, siginfo);
 158
 159         if (*argv) {
 160                 stdin_ok = isatty(STDIN_FILENO);
 161
 162                 if (Iflag && !iflag) {
 163                         if (check2(argv) == 0)
 164                                 exit (1);
 165                 }
 166                 if (rflag)
 167                         rm_tree(argv);
 168                 else
 169                         rm_file(argv);
 170         }
 171
 172         exit (eval);
 173 }
 174
 175 static void
 176 rm_tree(char **argv)
 177 {
 178         FTS *fts;
 179         FTSENT *p;
 180         int needstat;
 181         int flags;
 182         int rval;
 183
 184         /*
 185          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 186          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 187          */
 188         needstat = !uid || (!fflag && !iflag && stdin_ok);
 189
 190         /*
 191          * If the -i option is specified, the user can skip on the pre-order
 192          * visit.  The fts_number field flags skipped directories.
 193          */
 194 #define SKIPPED 1
 195
 196         flags = FTS_PHYSICAL;
 197         if (!needstat)
 198                 flags |= FTS_NOSTAT;
 199         if (Wflag)
 200                 flags |= FTS_WHITEOUT;
 201         if ((fts = fts_open(argv, flags, NULL)) == NULL) {
 202                 if (fflag && errno == ENOENT)
 203                         return;
 204                 err(1, NULL);
 205         }
 206         while ((p = fts_read(fts)) != NULL) {
 207                 switch (p->fts_info) {
 208                 case FTS_DNR:
 209                         if (!fflag || p->fts_errno != ENOENT) {
 210                                 warnx("%s: %s",
 211                                     p->fts_path, strerror(p->fts_errno));
 212                                 eval = 1;
 213                         }
 214                         continue;
 215                 case FTS_ERR:
 216                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 217                 case FTS_NS:
 218                        /*
 219                         * Assume that since fts_read() couldn't stat
 220                         * the file, it can't be unlinked.
 221                         */
 222                         if (!needstat)
 223                                 break;
 224                         if (!fflag || p->fts_errno != ENOENT) {
 225                                 warnx("%s: %s",
 226                                     p->fts_path, strerror(p->fts_errno));
 227                                 eval = 1;
 228                         }
 229                         continue;
 230                 case FTS_D:
 231                         /* Pre-order: give user chance to skip. */
 232                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 233                             p->fts_statp)) {
 234                                 fts_set(fts, p, FTS_SKIP);
 235                                 p->fts_number = SKIPPED;
 236                         }
 237                         else if (!uid &&
 238                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 239                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 240                                  chflags(p->fts_accpath,
 241                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 242                                 goto err;
 243                         continue;
 244                 case FTS_DP:
 245                         /* Post-order: see if user skipped. */
 246                         if (p->fts_number == SKIPPED)
 247                                 continue;
 248                         break;
 249                 default:
 250                         if (!fflag &&
 251                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 252                                 continue;
 253                 }
 254
 255                 if (info) {
 256                         info = 0;
 257                         fprintf(stderr, "Currently removing: %s\n", p->fts_path);
 258                 }
 259
 260                 rval = 0;
 261                 if (!uid &&
 262                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 263                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 264                         rval = chflags(p->fts_accpath,
 265                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 266
 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                                                 printf("%s\n",
 280                                                     p->fts_path);
 281                                         continue;
 282                                 }
 283                                 break;
 284
 285                         case FTS_W:
 286                                 rval = undelete(p->fts_accpath);
 287                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 288                                         if (vflag)
 289                                                 printf("%s\n",
 290                                                     p->fts_path);
 291                                         continue;
 292                                 }
 293                                 break;
 294
 295                         case FTS_NS:
 296                         /*
 297                          * Assume that since fts_read() couldn't stat
 298                          * the file, it can't be unlinked.
 299                          */
 300                                 if (fflag)
 301                                         continue;
 302                                 /* FALLTHROUGH */
 303                         default:
 304                                 if (Pflag)
 305                                         if (!rm_overwrite(p->fts_accpath, NULL))
 306                                                 continue;
 307                                 rval = unlink(p->fts_accpath);
 308                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 309                                         if (rval == 0 && vflag)
 310                                                 printf("%s\n",
 311                                                     p->fts_path);
 312                                         continue;
 313                                 }
 314                         }
 315                 }
 316 err:
 317                 warn("%s", p->fts_path);
 318                 eval = 1;
 319         }
 320         if (errno)
 321                 err(1, "fts_read");
 322         fts_close(fts);
 323 }
 324
 325 static void
 326 rm_file(char **argv)
 327 {
 328         struct stat sb;
 329         int rval;
 330         const char *f;
 331
 332         /*
 333          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 334          * to remove a directory is an error, so must always stat the file.
 335          */
 336         while ((f = *argv++) != NULL) {
 337                 if (info) {
 338                         info = 0;
 339                         fprintf(stderr, "Currently removing: %s\n", f);
 340                 }
 341
 342                 /* Assume if can't stat the file, can't unlink it. */
 343                 if (lstat(f, &sb)) {
 344                         if (Wflag) {
 345                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 346                         } else {
 347                                 if (!fflag || errno != ENOENT) {
 348                                         warn("%s", f);
 349                                         eval = 1;
 350                                 }
 351                                 continue;
 352                         }
 353                 } else if (Wflag) {
 354                         warnx("%s: %s", f, strerror(EEXIST));
 355                         eval = 1;
 356                         continue;
 357                 }
 358
 359                 if (S_ISDIR(sb.st_mode) && !dflag) {
 360                         warnx("%s: is a directory", f);
 361                         eval = 1;
 362                         continue;
 363                 }
 364                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 365                         continue;
 366                 rval = 0;
 367                 if (!uid &&
 368                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 369                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 370                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 371                 if (rval == 0) {
 372                         if (S_ISWHT(sb.st_mode))
 373                                 rval = undelete(f);
 374                         else if (S_ISDIR(sb.st_mode))
 375                                 rval = rmdir(f);
 376                         else {
 377                                 if (Pflag)
 378                                         if (!rm_overwrite(f, &sb))
 379                                                 continue;
 380                                 rval = unlink(f);
 381                         }
 382                 }
 383                 if (rval && (!fflag || errno != ENOENT)) {
 384                         warn("%s", f);
 385                         eval = 1;
 386                 }
 387                 if (vflag && rval == 0)
 388                         printf("%s\n", f);
 389         }
 390 }
 391
 392 /*
 393  * rm_overwrite --
 394  *      Overwrite the file 3 times with varying bit patterns.
 395  *
 396  * XXX
 397  * This is a cheap way to *really* delete files.  Note that only regular
 398  * files are deleted, directories (and therefore names) will remain.
 399  * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
 400  * System V filesystem).  In a logging filesystem, you'll have to have
 401  * kernel support.
 402  */
 403 static int
 404 rm_overwrite(const char *file, struct stat *sbp)
 405 {
 406         struct stat sb;
 407         struct statfs fsb;
 408         off_t len;
 409         int bsize, fd, wlen;
 410         char *buf = NULL;
 411
 412         fd = -1;
 413         if (sbp == NULL) {
 414                 if (lstat(file, &sb))
 415                         goto err;
 416                 sbp = &sb;
 417         }
 418         if (!S_ISREG(sbp->st_mode)) {
 419                 warnx("%s: cannot overwrite a non-regular file", file);
 420                 return (1);
 421         }
 422         if (sbp->st_nlink > 1) {
 423                 warnx("%s (inode %ju): not overwritten due to multiple links",
 424                       file, (uintmax_t)sbp->st_ino);
 425                 return (0);
 426         }
 427         if ((fd = open(file, O_WRONLY, 0)) == -1)
 428                 goto err;
 429         if (fstatfs(fd, &fsb) == -1)
 430                 goto err;
 431         bsize = MAX(fsb.f_iosize, 1024);
 432         if ((buf = malloc(bsize)) == NULL)
 433                 err(1, "%s malloc failed", file);
 434
 435 #define PASS(byte) {                                                    \
 436         memset(buf, byte, bsize);                                       \
 437         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 438                 wlen = len < bsize ? len : bsize;                       \
 439                 if (write(fd, buf, wlen) != wlen)                       \
 440                         goto err;                                       \
 441         }                                                               \
 442 }
 443         PASS(0xff);
 444         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 445                 goto err;
 446         PASS(0x00);
 447         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 448                 goto err;
 449         PASS(0xff);
 450         if (!fsync(fd) && !close(fd)) {
 451                 free(buf);
 452                 return (1);
 453         }
 454
 455 err:    eval = 1;
 456         if (buf)
 457                 free(buf);
 458         if (fd != -1)
 459                 close(fd);
 460         warn("%s", file);
 461         return (0);
 462 }
 463
 464
 465 static int
 466 check(const char *path, const char *name, struct stat *sp)
 467 {
 468         static int perm_answer = -1;
 469         struct choice {
 470                 int ch;
 471                 const char *str;
 472                 int res;
 473                 int perm;
 474         } *choice, choices[] = {
 475                 { 'y', "yes"   , 1, 0 },
 476                 { 'n', "no"    , 0, 0 },
 477                 { 'a', "always", 1, 1 },
 478                 { 'v', "never" , 0, 1 },
 479                 { 0, NULL, 0, 0 }
 480         };
 481         char modep[15], *flagsp;
 482
 483         if (perm_answer != -1)
 484                 return (perm_answer);
 485
 486         /* Check -i first. */
 487         if (iflag)
 488                 fprintf(stderr, "remove %s? ", path);
 489         else {
 490                 /*
 491                  * If it's not a symbolic link and it's unwritable and we're
 492                  * talking to a terminal, ask.  Symbolic links are excluded
 493                  * because their permissions are meaningless.  Check stdin_ok
 494                  * first because we may not have stat'ed the file.
 495                  * Also skip this check if the -P option was specified because
 496                  * we will not be able to overwrite file contents and will
 497                  * barf later.
 498                  */
 499                 if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
 500                     (!access(name, W_OK) &&
 501                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 502                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 503                         return (1);
 504                 strmode(sp->st_mode, modep);
 505                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 506                         err(1, NULL);
 507                 fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 508                     modep + 1, modep[9] == ' ' ? "" : " ",
 509                     user_from_uid(sp->st_uid, 0),
 510                     group_from_gid(sp->st_gid, 0),
 511                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 512                     path);
 513                 free(flagsp);
 514         }
 515         fflush(stderr);
 516
 517         for (;;) {
 518                 size_t len;
 519                 char *answer;
 520
 521                 answer = fgetln(stdin, &len);
 522                 /* clearerr(stdin); */
 523                 if (answer == NULL)
 524                         return (0);
 525                 if (answer[len - 1] == '\n')
 526                         len--;
 527                 if (len == 0)
 528                         continue;
 529
 530                 for (choice = choices; choice->str != NULL; choice++) {
 531                         if (len == 1 && choice->ch == answer[0])
 532                                 goto valid_choice;
 533                         if (strncasecmp(answer, choice->str, len) == 0)
 534                                 goto valid_choice;
 535                 }
 536
 537                 fprintf(stderr, "invalid answer, try again (y/n/a/v): ");
 538         }
 539
 540 valid_choice:
 541         if (choice->perm)
 542                 perm_answer = choice->res;
 543         return (choice->res);
 544 }
 545
 546 static int
 547 check2(char **argv)
 548 {
 549         struct stat st;
 550         int first;
 551         int ch;
 552         int fcount = 0;
 553         int dcount = 0;
 554         int i;
 555         const char *dname = NULL;
 556
 557         for (i = 0; argv[i]; ++i) {
 558                 if (lstat(argv[i], &st) == 0) {
 559                         if (S_ISDIR(st.st_mode)) {
 560                                 ++dcount;
 561                                 dname = argv[i];    /* only used if 1 dir */
 562                         } else {
 563                                 ++fcount;
 564                         }
 565                 }
 566         }
 567         first = 0;
 568         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 569                 if (dcount && rflag) {
 570                         fprintf(stderr, "recursively remove");
 571                         if (dcount == 1)
 572                                 fprintf(stderr, " %s", dname);
 573                         else
 574                                 fprintf(stderr, " %d dirs", dcount);
 575                         if (fcount == 1)
 576                                 fprintf(stderr, " and 1 file");
 577                         else if (fcount > 1)
 578                                 fprintf(stderr, " and %d files", fcount);
 579                 } else if (dcount + fcount > 3) {
 580                         fprintf(stderr, "remove %d files", dcount + fcount);
 581                 } else {
 582                         return(1);
 583                 }
 584                 fprintf(stderr, "? ");
 585                 fflush(stderr);
 586
 587                 first = ch = getchar();
 588                 while (ch != '\n' && ch != EOF)
 589                         ch = getchar();
 590                 if (ch == EOF)
 591                         break;
 592         }
 593         return (first == 'y' || first == 'Y');
 594 }
 595
 596 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 597 static void
 598 checkdot(char **argv)
 599 {
 600         char *p, **save, **t;
 601         int complained;
 602
 603         complained = 0;
 604         for (t = argv; *t;) {
 605                 if ((p = strrchr(*t, '/')) != NULL)
 606                         ++p;
 607                 else
 608                         p = *t;
 609                 if (ISDOT(p)) {
 610                         if (!complained++)
 611                                 warnx("\".\" and \"..\" may not be removed");
 612                         eval = 1;
 613                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 614                                 continue;
 615                         t = save;
 616                 } else
 617                         ++t;
 618         }
 619 }
 620
 621 static void
 622 usage(void)
 623 {
 624
 625         fprintf(stderr, "%s\n%s\n",
 626             "usage: rm [-f | -i] [-dIPRrvW] file ...",
 627             "       unlink file");
 628         exit(EX_USAGE);
 629 }
 630
 631 static void
 632 siginfo(int notused __unused)
 633 {
 634         info = 1;
 635 }