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. 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  * @(#) Copyright (c) 1990, 1993, 1994 The Regents of the University of California.  All rights reserved.
  30  * @(#)rm.c     8.5 (Berkeley) 4/18/94
  31  * $FreeBSD: src/bin/rm/rm.c,v 1.29.2.5 2002/07/12 07:25:48 tjr Exp $
  32  */
  33
  34 #include <sys/stat.h>
  35 #include <sys/param.h>
  36 #include <sys/mount.h>
  37 #include <sys/ioctl.h>
  38
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <fts.h>
  43 #include <grp.h>
  44 #include <pwd.h>
  45 #include <signal.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <sysexits.h>
  50 #include <unistd.h>
  51
  52 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  53 static int rflag, Iflag, xflag;
  54 static uid_t uid;
  55 static volatile sig_atomic_t info;
  56
  57 static int      check(const char *, const char *, struct stat *);
  58 static int      check2(char **);
  59 static void     checkdot(char **);
  60 static void     rm_file(char **);
  61 static int      rm_overwrite(const char *, struct stat *);
  62 static void     rm_tree(char **);
  63 static void     siginfo(int);
  64 static void     usage(void);
  65
  66 /*
  67  * rm --
  68  *      This rm is different from historic rm's, but is expected to match
  69  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  70  *      has two specific effects now, ignore non-existent files and force
  71  *      file removal.
  72  */
  73 int
  74 main(int argc, char *argv[])
  75 {
  76         int ch;
  77         const char *p;
  78         pid_t tty_pgrp;
  79
  80         /*
  81          * Test for the special case where the utility is called as
  82          * "unlink", for which the functionality provided is greatly
  83          * simplified.
  84          */
  85         if ((p = strrchr(argv[0], '/')) == NULL)
  86                 p = argv[0];
  87         else
  88                 ++p;
  89         if (strcmp(p, "unlink") == 0) {
  90                 while (getopt(argc, argv, "") != -1)
  91                         usage();
  92                 argc -= optind;
  93                 argv += optind;
  94                 if (argc != 1)
  95                         usage();
  96                 rm_file(&argv[0]);
  97                 exit(eval);
  98         }
  99
 100         Pflag = rflag = xflag = 0;
 101         while ((ch = getopt(argc, argv, "dfiIPRrvWx")) != -1) {
 102                 switch(ch) {
 103                 case 'd':
 104                         dflag = 1;
 105                         break;
 106                 case 'f':
 107                         fflag = 1;
 108                         iflag = 0;
 109                         break;
 110                 case 'i':
 111                         fflag = 0;
 112                         iflag = 1;
 113                         break;
 114                 case 'I':
 115                         /*
 116                          * The -I flag is intended to be generally aliasable
 117                          * in /etc/csh.cshrc.  We apply it only to foreground
 118                          * processes.
 119                          */
 120                         if (ioctl(0, TIOCGPGRP, &tty_pgrp) == 0) {
 121                                 if (tty_pgrp == getpgrp())
 122                                         Iflag = 1;
 123                         }
 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                 case 'x':
 139                         xflag = 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 (xflag)
 202                 flags |= FTS_XDEV;
 203         if ((fts = fts_open(argv, flags, NULL)) == NULL) {
 204                 if (fflag && errno == ENOENT)
 205                         return;
 206                 err(1, "fts_open");
 207         }
 208         while ((p = fts_read(fts)) != NULL) {
 209                 switch (p->fts_info) {
 210                 case FTS_DNR:
 211                         if (!fflag || p->fts_errno != ENOENT) {
 212                                 warnx("%s: %s",
 213                                     p->fts_path, strerror(p->fts_errno));
 214                                 eval = 1;
 215                         }
 216                         continue;
 217                 case FTS_ERR:
 218                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 219                 case FTS_NS:
 220                        /*
 221                         * Assume that since fts_read() couldn't stat
 222                         * the file, it can't be unlinked.
 223                         */
 224                         if (!needstat)
 225                                 break;
 226                         if (!fflag || p->fts_errno != ENOENT) {
 227                                 warnx("%s: %s",
 228                                     p->fts_path, strerror(p->fts_errno));
 229                                 eval = 1;
 230                         }
 231                         continue;
 232                 case FTS_D:
 233                         /* Pre-order: give user chance to skip. */
 234                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 235                             p->fts_statp)) {
 236                                 fts_set(fts, p, FTS_SKIP);
 237                                 p->fts_number = SKIPPED;
 238                         }
 239                         else if (!uid &&
 240                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 241                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 242                                  lchflags(p->fts_accpath,
 243                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 244                                 goto err;
 245                         continue;
 246                 case FTS_DP:
 247                         /* Post-order: see if user skipped. */
 248                         if (p->fts_number == SKIPPED)
 249                                 continue;
 250                         break;
 251                 default:
 252                         if (!fflag &&
 253                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 254                                 continue;
 255                 }
 256
 257                 if (info) {
 258                         info = 0;
 259                         fprintf(stderr, "Currently removing: %s\n", p->fts_path);
 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
 269                 if (rval == 0) {
 270                         /*
 271                          * If we can't read or search the directory, may still be
 272                          * able to remove it.  Don't print out the un{read,search}able
 273                          * message unless the remove fails.
 274                          */
 275                         switch (p->fts_info) {
 276                         case FTS_DP:
 277                         case FTS_DNR:
 278                                 rval = rmdir(p->fts_accpath);
 279                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 280                                         if (rval == 0 && vflag)
 281                                                 printf("%s\n",
 282                                                     p->fts_path);
 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                                                 printf("%s\n",
 292                                                     p->fts_path);
 293                                         continue;
 294                                 }
 295                                 break;
 296
 297                         case FTS_NS:
 298                         /*
 299                          * Assume that since fts_read() couldn't stat
 300                          * the file, it can't be unlinked.
 301                          */
 302                                 if (fflag)
 303                                         continue;
 304                                 /* FALLTHROUGH */
 305                         default:
 306                                 if (Pflag)
 307                                         if (!rm_overwrite(p->fts_accpath, NULL))
 308                                                 continue;
 309                                 rval = unlink(p->fts_accpath);
 310                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 311                                         if (rval == 0 && vflag)
 312                                                 printf("%s\n",
 313                                                     p->fts_path);
 314                                         continue;
 315                                 }
 316                         }
 317                 }
 318 err:
 319                 warn("%s", p->fts_path);
 320                 eval = 1;
 321         }
 322         if (errno)
 323                 err(1, "fts_read");
 324         fts_close(fts);
 325 }
 326
 327 static void
 328 rm_file(char **argv)
 329 {
 330         struct stat sb;
 331         int rval;
 332         const char *f;
 333
 334         /*
 335          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 336          * to remove a directory is an error, so must always stat the file.
 337          */
 338         while ((f = *argv++) != NULL) {
 339                 if (info) {
 340                         info = 0;
 341                         fprintf(stderr, "Currently removing: %s\n", f);
 342                 }
 343
 344                 /* Assume if can't stat the file, can't unlink it. */
 345                 if (lstat(f, &sb)) {
 346                         if (Wflag) {
 347                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 348                         } else {
 349                                 if (!fflag || errno != ENOENT) {
 350                                         warn("%s", f);
 351                                         eval = 1;
 352                                 }
 353                                 continue;
 354                         }
 355                 } else if (Wflag) {
 356                         warnx("%s: %s", f, strerror(EEXIST));
 357                         eval = 1;
 358                         continue;
 359                 }
 360
 361                 if (S_ISDIR(sb.st_mode) && !dflag) {
 362                         warnx("%s: is a directory", f);
 363                         eval = 1;
 364                         continue;
 365                 }
 366                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 367                         continue;
 368                 rval = 0;
 369                 if (!uid && !S_ISWHT(sb.st_mode) &&
 370                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 371                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 372                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 373                 if (rval == 0) {
 374                         if (S_ISWHT(sb.st_mode))
 375                                 rval = undelete(f);
 376                         else if (S_ISDIR(sb.st_mode))
 377                                 rval = rmdir(f);
 378                         else {
 379                                 if (Pflag)
 380                                         if (!rm_overwrite(f, &sb))
 381                                                 continue;
 382                                 rval = unlink(f);
 383                         }
 384                 }
 385                 if (rval && (!fflag || errno != ENOENT)) {
 386                         warn("%s", f);
 387                         eval = 1;
 388                 }
 389                 if (vflag && rval == 0)
 390                         printf("%s\n", f);
 391         }
 392 }
 393
 394 /*
 395  * rm_overwrite --
 396  *      Overwrite the file 3 times with varying bit patterns.
 397  *
 398  * XXX
 399  * This is a cheap way to *really* delete files.  Note that only regular
 400  * files are deleted, directories (and therefore names) will remain.
 401  * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
 402  * System V filesystem).  In a logging filesystem, you'll have to have
 403  * kernel support.
 404  */
 405 static int
 406 rm_overwrite(const char *file, struct stat *sbp)
 407 {
 408         struct stat sb;
 409         struct statfs fsb;
 410         off_t len;
 411         int bsize, fd, wlen;
 412         char *buf = NULL;
 413
 414         fd = -1;
 415         if (sbp == NULL) {
 416                 if (lstat(file, &sb))
 417                         goto err;
 418                 sbp = &sb;
 419         }
 420         if (!S_ISREG(sbp->st_mode)) {
 421                 warnx("%s: cannot overwrite a non-regular file", file);
 422                 return (1);
 423         }
 424         if (sbp->st_nlink > 1) {
 425                 warnx("%s (inode %ju): not overwritten due to multiple links",
 426                       file, (uintmax_t)sbp->st_ino);
 427                 return (0);
 428         }
 429         if ((fd = open(file, O_WRONLY, 0)) == -1)
 430                 goto err;
 431         if (fstatfs(fd, &fsb) == -1)
 432                 goto err;
 433         bsize = MAX(fsb.f_iosize, 1024);
 434         if ((buf = malloc(bsize)) == NULL)
 435                 err(1, "%s malloc failed", file);
 436
 437 #define PASS(byte) {                                                    \
 438         memset(buf, byte, bsize);                                       \
 439         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 440                 wlen = len < bsize ? len : bsize;                       \
 441                 if (write(fd, buf, wlen) != wlen)                       \
 442                         goto err;                                       \
 443         }                                                               \
 444 }
 445         PASS(0xff);
 446         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 447                 goto err;
 448         PASS(0x00);
 449         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 450                 goto err;
 451         PASS(0xff);
 452         if (!fsync(fd) && !close(fd)) {
 453                 free(buf);
 454                 return (1);
 455         }
 456
 457 err:    eval = 1;
 458         if (buf)
 459                 free(buf);
 460         if (fd != -1)
 461                 close(fd);
 462         warn("%s", file);
 463         return (0);
 464 }
 465
 466
 467 static int
 468 check(const char *path, const char *name, struct stat *sp)
 469 {
 470         static int perm_answer = -1;
 471         struct choice {
 472                 int ch;
 473                 const char *str;
 474                 int res;
 475                 int perm;
 476         } *choice, choices[] = {
 477                 { 'y', "yes"   , 1, 0 },
 478                 { 'n', "no"    , 0, 0 },
 479                 { 'a', "always", 1, 1 },
 480                 { 'v', "never" , 0, 1 },
 481                 { 0, NULL, 0, 0 }
 482         };
 483         char modep[15], *flagsp;
 484
 485         if (perm_answer != -1)
 486                 return (perm_answer);
 487
 488         /* Check -i first. */
 489         if (iflag)
 490                 fprintf(stderr, "remove %s? ", path);
 491         else {
 492                 /*
 493                  * If it's not a symbolic link and it's unwritable and we're
 494                  * talking to a terminal, ask.  Symbolic links are excluded
 495                  * because their permissions are meaningless.  Check stdin_ok
 496                  * first because we may not have stat'ed the file.
 497                  * Also skip this check if the -P option was specified because
 498                  * we will not be able to overwrite file contents and will
 499                  * barf later.
 500                  */
 501                 if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
 502                     (!access(name, W_OK) &&
 503                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 504                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 505                         return (1);
 506                 strmode(sp->st_mode, modep);
 507                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 508                         err(1, NULL);
 509                 fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 510                     modep + 1, modep[9] == ' ' ? "" : " ",
 511                     user_from_uid(sp->st_uid, 0),
 512                     group_from_gid(sp->st_gid, 0),
 513                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 514                     path);
 515                 free(flagsp);
 516         }
 517         fflush(stderr);
 518
 519         for (;;) {
 520                 size_t len;
 521                 char *answer;
 522
 523                 answer = fgetln(stdin, &len);
 524                 /* clearerr(stdin); */
 525                 if (answer == NULL)
 526                         return (0);
 527                 if (answer[len - 1] == '\n')
 528                         len--;
 529                 if (len == 0)
 530                         continue;
 531
 532                 for (choice = choices; choice->str != NULL; choice++) {
 533                         if (len == 1 && choice->ch == answer[0])
 534                                 goto valid_choice;
 535                         if (strncasecmp(answer, choice->str, len) == 0)
 536                                 goto valid_choice;
 537                 }
 538
 539                 fprintf(stderr, "invalid answer, try again (y/n/a/v): ");
 540         }
 541
 542 valid_choice:
 543         if (choice->perm)
 544                 perm_answer = choice->res;
 545         return (choice->res);
 546 }
 547
 548 static int
 549 check2(char **argv)
 550 {
 551         struct stat st;
 552         int first;
 553         int ch;
 554         int fcount = 0;
 555         int dcount = 0;
 556         int i;
 557         const char *dname = NULL;
 558
 559         for (i = 0; argv[i]; ++i) {
 560                 if (lstat(argv[i], &st) == 0) {
 561                         if (S_ISDIR(st.st_mode)) {
 562                                 ++dcount;
 563                                 dname = argv[i];    /* only used if 1 dir */
 564                         } else {
 565                                 ++fcount;
 566                         }
 567                 }
 568         }
 569         first = 0;
 570         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 571                 if (dcount && rflag) {
 572                         fprintf(stderr, "recursively remove");
 573                         if (dcount == 1)
 574                                 fprintf(stderr, " %s", dname);
 575                         else
 576                                 fprintf(stderr, " %d dirs", dcount);
 577                         if (fcount == 1)
 578                                 fprintf(stderr, " and 1 file");
 579                         else if (fcount > 1)
 580                                 fprintf(stderr, " and %d files", fcount);
 581                 } else if (dcount + fcount > 3) {
 582                         fprintf(stderr, "remove %d files", dcount + fcount);
 583                 } else {
 584                         return(1);
 585                 }
 586                 fprintf(stderr, "? ");
 587                 fflush(stderr);
 588
 589                 first = ch = getchar();
 590                 while (ch != '\n' && ch != EOF)
 591                         ch = getchar();
 592                 if (ch == EOF)
 593                         break;
 594         }
 595         return (first == 'y' || first == 'Y');
 596 }
 597
 598 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 599 static void
 600 checkdot(char **argv)
 601 {
 602         char *p, **save, **t;
 603         int complained;
 604
 605         complained = 0;
 606         for (t = argv; *t;) {
 607                 if ((p = strrchr(*t, '/')) != NULL)
 608                         ++p;
 609                 else
 610                         p = *t;
 611                 if (ISDOT(p)) {
 612                         if (!complained++)
 613                                 warnx("\".\" and \"..\" may not be removed");
 614                         eval = 1;
 615                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 616                                 continue;
 617                         t = save;
 618                 } else
 619                         ++t;
 620         }
 621 }
 622
 623 static void
 624 usage(void)
 625 {
 626
 627         fprintf(stderr, "%s\n%s\n",
 628             "usage: rm [-f | -i] [-dIPRrvWx] file ...",
 629             "       unlink file");
 630         exit(EX_USAGE);
 631 }
 632
 633 static void
 634 siginfo(int notused __unused)
 635 {
 636         info = 1;
 637 }