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 <stdint.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <sysexits.h>
  51 #include <unistd.h>
  52
  53 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  54 static int rflag, Iflag, xflag;
  55 static uid_t uid;
  56 static volatile sig_atomic_t info;
  57
  58 static int      check(const char *, const char *, struct stat *);
  59 static int      check2(char **);
  60 static void     checkdot(char **);
  61 static void     rm_file(char **);
  62 static int      rm_overwrite(const char *, struct stat *);
  63 static void     rm_tree(char **);
  64 #ifdef SIGINFO
  65 static void     siginfo(int);
  66 #endif
  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 = xflag = 0;
 104         while ((ch = getopt(argc, argv, "dfiIPRrvWx")) != -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 #ifdef S_IFWHT
 140                         Wflag = 1;
 141 #endif
 142                         break;
 143                 case 'x':
 144                         xflag = 1;
 145                         break;
 146                 default:
 147                         usage();
 148                 }
 149         }
 150         argc -= optind;
 151         argv += optind;
 152
 153         if (argc < 1) {
 154                 if (fflag)
 155                         return 0;
 156                 usage();
 157         }
 158
 159         checkdot(argv);
 160         uid = geteuid();
 161
 162 #ifdef SIGINFO
 163         signal(SIGINFO, siginfo);
 164 #endif
 165
 166         if (*argv) {
 167                 stdin_ok = isatty(STDIN_FILENO);
 168
 169                 if (Iflag && !iflag) {
 170                         if (check2(argv) == 0)
 171                                 exit (1);
 172                 }
 173                 if (rflag)
 174                         rm_tree(argv);
 175                 else
 176                         rm_file(argv);
 177         }
 178
 179         exit (eval);
 180 }
 181
 182 static void
 183 rm_tree(char **argv)
 184 {
 185         FTS *fts;
 186         FTSENT *p;
 187         int needstat;
 188         int flags;
 189         int rval;
 190
 191         /*
 192          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 193          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 194          */
 195         needstat = !uid || (!fflag && !iflag && stdin_ok);
 196
 197         /*
 198          * If the -i option is specified, the user can skip on the pre-order
 199          * visit.  The fts_number field flags skipped directories.
 200          */
 201 #define SKIPPED 1
 202
 203         flags = FTS_PHYSICAL;
 204         if (!needstat)
 205                 flags |= FTS_NOSTAT;
 206 #ifdef S_IFWHT
 207         if (Wflag)
 208                 flags |= FTS_WHITEOUT;
 209 #endif
 210         if (xflag)
 211                 flags |= FTS_XDEV;
 212         if ((fts = fts_open(argv, flags, NULL)) == NULL) {
 213                 if (fflag && errno == ENOENT)
 214                         return;
 215                 err(1, "fts_open");
 216         }
 217         while ((p = fts_read(fts)) != NULL) {
 218                 switch (p->fts_info) {
 219                 case FTS_DNR:
 220                         if (!fflag || p->fts_errno != ENOENT) {
 221                                 warnx("%s: %s",
 222                                     p->fts_path, strerror(p->fts_errno));
 223                                 eval = 1;
 224                         }
 225                         continue;
 226                 case FTS_ERR:
 227                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 228                 case FTS_NS:
 229                        /*
 230                         * Assume that since fts_read() couldn't stat
 231                         * the file, it can't be unlinked.
 232                         */
 233                         if (!needstat)
 234                                 break;
 235                         if (!fflag || p->fts_errno != ENOENT) {
 236                                 warnx("%s: %s",
 237                                     p->fts_path, strerror(p->fts_errno));
 238                                 eval = 1;
 239                         }
 240                         continue;
 241                 case FTS_D:
 242                         /* Pre-order: give user chance to skip. */
 243                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 244                             p->fts_statp)) {
 245                                 fts_set(fts, p, FTS_SKIP);
 246                                 p->fts_number = SKIPPED;
 247                         }
 248 #ifdef _ST_FLAGS_PRESENT_
 249                         else if (!uid &&
 250                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 251                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 252                                  lchflags(p->fts_accpath,
 253                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 254                                 goto err;
 255 #endif
 256                         continue;
 257                 case FTS_DP:
 258                         /* Post-order: see if user skipped. */
 259                         if (p->fts_number == SKIPPED)
 260                                 continue;
 261                         break;
 262                 default:
 263                         if (!fflag &&
 264                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 265                                 continue;
 266                 }
 267
 268                 if (info) {
 269                         info = 0;
 270                         fprintf(stderr, "Currently removing: %s\n", p->fts_path);
 271                 }
 272
 273                 rval = 0;
 274 #ifdef _ST_FLAGS_PRESENT_
 275                 if (!uid &&
 276                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 277                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 278                         rval = lchflags(p->fts_accpath,
 279                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 280 #endif
 281
 282                 if (rval == 0) {
 283                         /*
 284                          * If we can't read or search the directory, may still be
 285                          * able to remove it.  Don't print out the un{read,search}able
 286                          * message unless the remove fails.
 287                          */
 288                         switch (p->fts_info) {
 289                         case FTS_DP:
 290                         case FTS_DNR:
 291                                 rval = rmdir(p->fts_accpath);
 292                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 293                                         if (rval == 0 && vflag)
 294                                                 printf("%s\n",
 295                                                     p->fts_path);
 296                                         continue;
 297                                 }
 298                                 break;
 299 #ifdef S_IFWHT
 300                         case FTS_W:
 301                                 rval = undelete(p->fts_accpath);
 302                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 303                                         if (vflag)
 304                                                 printf("%s\n",
 305                                                     p->fts_path);
 306                                         continue;
 307                                 }
 308                                 break;
 309 #endif
 310                         case FTS_NS:
 311                         /*
 312                          * Assume that since fts_read() couldn't stat
 313                          * the file, it can't be unlinked.
 314                          */
 315                                 if (fflag)
 316                                         continue;
 317                                 /* FALLTHROUGH */
 318                         default:
 319                                 if (Pflag)
 320                                         if (!rm_overwrite(p->fts_accpath, NULL))
 321                                                 continue;
 322                                 rval = unlink(p->fts_accpath);
 323                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 324                                         if (rval == 0 && vflag)
 325                                                 printf("%s\n",
 326                                                     p->fts_path);
 327                                         continue;
 328                                 }
 329                         }
 330                 }
 331 #ifdef _ST_FLAGS_PRESENT_
 332 err:
 333 #endif
 334                 warn("%s", p->fts_path);
 335                 eval = 1;
 336         }
 337         if (errno)
 338                 err(1, "fts_read");
 339         fts_close(fts);
 340 }
 341
 342 static void
 343 rm_file(char **argv)
 344 {
 345         struct stat sb;
 346         int rval;
 347         const char *f;
 348
 349         /*
 350          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 351          * to remove a directory is an error, so must always stat the file.
 352          */
 353         while ((f = *argv++) != NULL) {
 354                 if (info) {
 355                         info = 0;
 356                         fprintf(stderr, "Currently removing: %s\n", f);
 357                 }
 358
 359                 /* Assume if can't stat the file, can't unlink it. */
 360                 if (lstat(f, &sb)) {
 361                         if (Wflag) {
 362 #ifdef S_IFWHT
 363                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 364 #endif
 365                         } else {
 366                                 if (!fflag || errno != ENOENT) {
 367                                         warn("%s", f);
 368                                         eval = 1;
 369                                 }
 370                                 continue;
 371                         }
 372                 } else if (Wflag) {
 373                         warnx("%s: %s", f, strerror(EEXIST));
 374                         eval = 1;
 375                         continue;
 376                 }
 377
 378                 if (S_ISDIR(sb.st_mode) && !dflag) {
 379                         warnx("%s: is a directory", f);
 380                         eval = 1;
 381                         continue;
 382                 }
 383                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 384                         continue;
 385                 rval = 0;
 386 #ifdef _ST_FLAGS_PRESENT_
 387                 if (!uid && !S_ISWHT(sb.st_mode) &&
 388                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 389                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 390                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 391 #endif
 392                 if (rval == 0) {
 393 #ifdef S_IFWHT
 394                         if (S_ISWHT(sb.st_mode))
 395                                 rval = undelete(f);
 396                         else
 397 #endif
 398                         if (S_ISDIR(sb.st_mode))
 399                                 rval = rmdir(f);
 400                         else {
 401                                 if (Pflag)
 402                                         if (!rm_overwrite(f, &sb))
 403                                                 continue;
 404                                 rval = unlink(f);
 405                         }
 406                 }
 407                 if (rval && (!fflag || errno != ENOENT)) {
 408                         warn("%s", f);
 409                         eval = 1;
 410                 }
 411                 if (vflag && rval == 0)
 412                         printf("%s\n", f);
 413         }
 414 }
 415
 416 /*
 417  * rm_overwrite --
 418  *      Overwrite the file 3 times with varying bit patterns.
 419  *
 420  * XXX
 421  * This is a cheap way to *really* delete files.  Note that only regular
 422  * files are deleted, directories (and therefore names) will remain.
 423  * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
 424  * System V filesystem).  In a logging filesystem, you'll have to have
 425  * kernel support.
 426  */
 427 static int
 428 rm_overwrite(const char *file, struct stat *sbp)
 429 {
 430         struct stat sb;
 431         struct statfs fsb;
 432         off_t len;
 433         int bsize, fd, wlen;
 434         char *buf = NULL;
 435
 436         fd = -1;
 437         if (sbp == NULL) {
 438                 if (lstat(file, &sb))
 439                         goto err;
 440                 sbp = &sb;
 441         }
 442         if (!S_ISREG(sbp->st_mode)) {
 443                 warnx("%s: cannot overwrite a non-regular file", file);
 444                 return (1);
 445         }
 446         if (sbp->st_nlink > 1) {
 447                 warnx("%s (inode %ju): not overwritten due to multiple links",
 448                       file, (uintmax_t)sbp->st_ino);
 449                 return (0);
 450         }
 451         if ((fd = open(file, O_WRONLY, 0)) == -1)
 452                 goto err;
 453         if (fstatfs(fd, &fsb) == -1)
 454                 goto err;
 455         bsize = MAX(fsb.f_iosize, 1024);
 456         if ((buf = malloc(bsize)) == NULL)
 457                 err(1, "%s malloc failed", file);
 458
 459 #define PASS(byte) {                                                    \
 460         memset(buf, byte, bsize);                                       \
 461         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 462                 wlen = len < bsize ? len : bsize;                       \
 463                 if (write(fd, buf, wlen) != wlen)                       \
 464                         goto err;                                       \
 465         }                                                               \
 466 }
 467         PASS(0xff);
 468         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 469                 goto err;
 470         PASS(0x00);
 471         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 472                 goto err;
 473         PASS(0xff);
 474         if (!fsync(fd) && !close(fd)) {
 475                 free(buf);
 476                 return (1);
 477         }
 478
 479 err:    eval = 1;
 480         if (buf)
 481                 free(buf);
 482         if (fd != -1)
 483                 close(fd);
 484         warn("%s", file);
 485         return (0);
 486 }
 487
 488
 489 static int
 490 check(const char *path, const char *name, struct stat *sp)
 491 {
 492         static int perm_answer = -1;
 493         struct choice {
 494                 int ch;
 495                 const char *str;
 496                 int res;
 497                 int perm;
 498         } *choice, choices[] = {
 499                 { 'y', "yes"   , 1, 0 },
 500                 { 'n', "no"    , 0, 0 },
 501                 { 'a', "always", 1, 1 },
 502                 { 'v', "never" , 0, 1 },
 503                 { 0, NULL, 0, 0 }
 504         };
 505         char modep[15], *flagsp = NULL;
 506
 507         if (perm_answer != -1)
 508                 return (perm_answer);
 509
 510         /* Check -i first. */
 511         if (iflag)
 512                 fprintf(stderr, "remove %s? ", path);
 513         else {
 514                 /*
 515                  * If it's not a symbolic link and it's unwritable and we're
 516                  * talking to a terminal, ask.  Symbolic links are excluded
 517                  * because their permissions are meaningless.  Check stdin_ok
 518                  * first because we may not have stat'ed the file.
 519                  * Also skip this check if the -P option was specified because
 520                  * we will not be able to overwrite file contents and will
 521                  * barf later.
 522                  */
 523                 if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
 524                     (!access(name, W_OK)
 525 #ifdef _ST_FLAGS_PRESENT_
 526                     && !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 527                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)
 528 #endif
 529                     ))
 530                         return (1);
 531                 strmode(sp->st_mode, modep);
 532 #ifdef _ST_FLAGS_PRESENT_
 533                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 534                         err(1, NULL);
 535 #endif
 536                 fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 537                     modep + 1, modep[9] == ' ' ? "" : " ",
 538                     user_from_uid(sp->st_uid, 0),
 539                     group_from_gid(sp->st_gid, 0),
 540                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 541                     path);
 542                 free(flagsp);
 543         }
 544         fflush(stderr);
 545
 546         for (;;) {
 547                 size_t len;
 548                 char *answer;
 549
 550                 answer = fgetln(stdin, &len);
 551                 /* clearerr(stdin); */
 552                 if (answer == NULL)
 553                         return (0);
 554                 if (answer[len - 1] == '\n')
 555                         len--;
 556                 if (len == 0)
 557                         continue;
 558
 559                 for (choice = choices; choice->str != NULL; choice++) {
 560                         if (len == 1 && choice->ch == answer[0])
 561                                 goto valid_choice;
 562                         if (strncasecmp(answer, choice->str, len) == 0)
 563                                 goto valid_choice;
 564                 }
 565
 566                 fprintf(stderr, "invalid answer, try again (y/n/a/v): ");
 567         }
 568
 569 valid_choice:
 570         if (choice->perm)
 571                 perm_answer = choice->res;
 572         return (choice->res);
 573 }
 574
 575 static int
 576 check2(char **argv)
 577 {
 578         struct stat st;
 579         int first;
 580         int ch;
 581         int fcount = 0;
 582         int dcount = 0;
 583         int i;
 584         const char *dname = NULL;
 585
 586         for (i = 0; argv[i]; ++i) {
 587                 if (lstat(argv[i], &st) == 0) {
 588                         if (S_ISDIR(st.st_mode)) {
 589                                 ++dcount;
 590                                 dname = argv[i];    /* only used if 1 dir */
 591                         } else {
 592                                 ++fcount;
 593                         }
 594                 }
 595         }
 596         first = 0;
 597         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 598                 if (dcount && rflag) {
 599                         fprintf(stderr, "recursively remove");
 600                         if (dcount == 1)
 601                                 fprintf(stderr, " %s", dname);
 602                         else
 603                                 fprintf(stderr, " %d dirs", dcount);
 604                         if (fcount == 1)
 605                                 fprintf(stderr, " and 1 file");
 606                         else if (fcount > 1)
 607                                 fprintf(stderr, " and %d files", fcount);
 608                 } else if (dcount + fcount > 3) {
 609                         fprintf(stderr, "remove %d files", dcount + fcount);
 610                 } else {
 611                         return(1);
 612                 }
 613                 fprintf(stderr, "? ");
 614                 fflush(stderr);
 615
 616                 first = ch = getchar();
 617                 while (ch != '\n' && ch != EOF)
 618                         ch = getchar();
 619                 if (ch == EOF)
 620                         break;
 621         }
 622         return (first == 'y' || first == 'Y');
 623 }
 624
 625 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 626 static void
 627 checkdot(char **argv)
 628 {
 629         char *p, **save, **t;
 630         int complained;
 631
 632         complained = 0;
 633         for (t = argv; *t;) {
 634                 if ((p = strrchr(*t, '/')) != NULL)
 635                         ++p;
 636                 else
 637                         p = *t;
 638                 if (ISDOT(p)) {
 639                         if (!complained++)
 640                                 warnx("\".\" and \"..\" may not be removed");
 641                         eval = 1;
 642                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 643                                 continue;
 644                         t = save;
 645                 } else
 646                         ++t;
 647         }
 648 }
 649
 650 static void
 651 usage(void)
 652 {
 653
 654         fprintf(stderr, "%s\n%s\n",
 655             "usage: rm [-f | -i] [-dIPRrvWx] file ...",
 656             "       unlink file");
 657         exit(EX_USAGE);
 658 }
 659
 660 #ifdef SIGINFO
 661 static void
 662 siginfo(int notused __unused)
 663 {
 664         info = 1;
 665 }
 666 #endif