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
  34 #include <sys/cdefs.h>
  35 #ifndef lint
  36 __used static const char copyright[] =
  37 "@(#) Copyright (c) 1990, 1993, 1994\n\
  38         The Regents of the University of California.  All rights reserved.\n";
  39 #endif /* not lint */
  40
  41 #ifndef lint
  42 #if 0
  43 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  44 #else
  45 __used static const char rcsid[] =
  46   "$FreeBSD: src/bin/rm/rm.c,v 1.33 2001/06/13 15:01:25 ru Exp $";
  47 #endif
  48 #endif /* not lint */
  49
  50 #include <sys/stat.h>
  51 #include <sys/param.h>
  52 #include <sys/mount.h>
  53
  54 #include <err.h>
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <fts.h>
  58 #include <stdio.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include <sysexits.h>
  62 #include <unistd.h>
  63
  64 #ifdef __APPLE__
  65 #include <removefile.h>
  66 #include <pwd.h>
  67 #include <grp.h>
  68 #include "get_compat.h"
  69 #else
  70 #define COMPAT_MODE(func, mode) 1
  71 #endif
  72
  73 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  74 uid_t uid;
  75
  76 int     check __P((char *, char *, struct stat *));
  77 int checkdir __P((char *));
  78 int             yes_or_no __P((void));
  79 void    checkdot __P((char **));
  80 void    rm_file __P((char **));
  81 void    rm_overwrite __P((char *, struct stat *));
  82 void    rm_tree __P((char **));
  83 void    usage __P((void));
  84
  85 /*
  86  * rm --
  87  *      This rm is different from historic rm's, but is expected to match
  88  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  89  *      has two specific effects now, ignore non-existent files and force
  90  *      file removal.
  91  */
  92 int
  93 main(argc, argv)
  94         int argc;
  95         char *argv[];
  96 {
  97         int ch, rflag;
  98         char *p;
  99
 100         if (argc < 1)
 101                 usage();
 102
 103         /*
 104          * Test for the special case where the utility is called as
 105          * "unlink", for which the functionality provided is greatly
 106          * simplified.
 107          */
 108         if ((p = rindex(argv[0], '/')) == NULL)
 109                 p = argv[0];
 110         else
 111                 ++p;
 112         uid = geteuid();
 113         if (strcmp(p, "unlink") == 0) {
 114                 if (argc == 2) {
 115                         rm_file(&argv[1]);
 116                         exit(eval);
 117                 } else
 118                         usage();
 119         }
 120
 121         Pflag = rflag = 0;
 122         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 123                 switch(ch) {
 124                 case 'd':
 125                         dflag = 1;
 126                         break;
 127                 case 'f':
 128                         fflag = 1;
 129                         iflag = 0;
 130                         break;
 131                 case 'i':
 132                         fflag = 0;
 133                         iflag = 1;
 134                         break;
 135                 case 'P':
 136                         Pflag = 1;
 137                         break;
 138                 case 'R':
 139                 case 'r':                       /* Compatibility. */
 140                         rflag = 1;
 141                         break;
 142                 case 'v':
 143                         vflag = 1;
 144                         break;
 145                 case 'W':
 146                         Wflag = 1;
 147                         break;
 148                 default:
 149                         usage();
 150                 }
 151         argc -= optind;
 152         argv += optind;
 153
 154         if (argc < 1) {
 155                 if (fflag)
 156                         return 0;
 157                 usage();
 158         }
 159
 160         checkdot(argv);
 161
 162         if (*argv) {
 163                 stdin_ok = isatty(STDIN_FILENO);
 164
 165                 if (rflag)
 166                         rm_tree(argv);
 167                 else
 168                         rm_file(argv);
 169         }
 170
 171         exit (eval);
 172 }
 173
 174 void
 175 rm_tree(argv)
 176         char **argv;
 177 {
 178         FTS *fts;
 179         FTSENT *p;
 180         int needstat;
 181         int flags;
 182         int rval;
 183         int wantConformance = COMPAT_MODE("bin/rm", "unix2003");
 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))) {
 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                          * FTS_NS: assume that if can't stat the file, it
 220                          * 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                         /* In conformance mode the user is prompted to skip processing the contents.
 233                          * Then the option to delete the dir is presented post-order */
 234                         if (!fflag &&
 235                                         ( (wantConformance && !checkdir(p->fts_path)) ||
 236                                           (!wantConformance && !check(p->fts_path, p->fts_accpath, p->fts_statp))
 237                                         )
 238                            ){
 239                                 (void)fts_set(fts, p, FTS_SKIP);
 240                                 p->fts_number = SKIPPED;
 241                         }
 242                         else if (!uid &&
 243                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 244                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 245                                  chflags(p->fts_accpath,
 246                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 247                                 goto err;
 248                         continue;
 249                 case FTS_DP:
 250                         /* Post-order: see if user skipped. */
 251                         if(p->fts_number == SKIPPED)/*in legacy mode, the user was prompted pre-order */
 252                                 continue;
 253                         else if(wantConformance)
 254                         {
 255                                 /* delete directory if force is on, or if user answers Y to prompt */
 256                                 if(fflag || check(p->fts_path, p->fts_accpath, p->fts_statp))
 257                                         break;
 258                                 else
 259                                         continue;
 260                         }
 261                         break;
 262                 default:
 263                         if (!fflag &&
 264                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 265                                 continue;
 266                 }
 267
 268                 rval = 0;
 269                 if (!uid &&
 270                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 271                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 272                         rval = chflags(p->fts_accpath,
 273                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 274                 if (rval == 0) {
 275                         /*
 276                          * If we can't read or search the directory, may still be
 277                          * able to remove it.  Don't print out the un{read,search}able
 278                          * message unless the remove fails.
 279                          */
 280                         switch (p->fts_info) {
 281                         case FTS_DP:
 282                         case FTS_DNR:
 283                                 rval = rmdir(p->fts_accpath);
 284                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 285                                         if (rval == 0 && vflag)
 286                                                 (void)printf("%s\n",
 287                                                     p->fts_path);
 288                                         continue;
 289                                 }
 290                                 break;
 291
 292                         case FTS_W:
 293                                 rval = undelete(p->fts_accpath);
 294                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 295                                         if (vflag)
 296                                                 (void)printf("%s\n",
 297                                                     p->fts_path);
 298                                         continue;
 299                                 }
 300                                 break;
 301
 302                         default:
 303 #ifdef __APPLE__
 304                                 if (Pflag) {
 305                                         if (removefile(p->fts_accpath, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 306                                                 eval = rval = 1;
 307                                 } else
 308                                         rval = unlink(p->fts_accpath);
 309 #else  /* !__APPLE_ */
 310                                 if (Pflag)
 311                                         rm_overwrite(p->fts_accpath, NULL);
 312                                 rval = unlink(p->fts_accpath);
 313 #endif  /* __APPLE__ */
 314                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 315                                         if (rval == 0 && vflag)
 316                                                 (void)printf("%s\n",
 317                                                     p->fts_path);
 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(argv)
 333         char **argv;
 334 {
 335         struct stat sb;
 336         int rval;
 337         char *f;
 338
 339         /*
 340          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 341          * to remove a directory is an error, so must always stat the file.
 342          */
 343         while ((f = *argv++) != NULL) {
 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 &&
 370                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 371                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 372                         rval = chflags(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 #ifdef __APPLE__
 380                                 if (Pflag) {
 381                                         if (removefile(f, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 382                                                 eval = rval = 1;
 383                                 } else
 384                                         rval = unlink(f);
 385 #else  /* !__APPLE__ */
 386                                 if (Pflag)
 387                                         rm_overwrite(f, &sb);
 388                                 rval = unlink(f);
 389 #endif  /* __APPLE__ */
 390                         }
 391                 }
 392                 if (rval && (!fflag || errno != ENOENT)) {
 393                         warn("%s", f);
 394                         eval = 1;
 395                 }
 396                 if (vflag && rval == 0)
 397                         (void)printf("%s\n", f);
 398         }
 399 }
 400
 401 /*
 402  * rm_overwrite --
 403  *      Overwrite the file 3 times with varying bit patterns.
 404  *
 405  * XXX
 406  * This is a cheap way to *really* delete files.  Note that only regular
 407  * files are deleted, directories (and therefore names) will remain.
 408  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 409  * System V file system).  In a logging file system, you'll have to have
 410  * kernel support.
 411  */
 412 void
 413 rm_overwrite(file, sbp)
 414         char *file;
 415         struct stat *sbp;
 416 {
 417         struct stat sb;
 418         struct statfs fsb;
 419         off_t len;
 420         int bsize, fd, wlen;
 421         char *buf = NULL;
 422
 423         if (sbp == NULL) {
 424                 if (lstat(file, &sb))
 425                         goto err;
 426                 sbp = &sb;
 427         }
 428         if (!S_ISREG(sbp->st_mode))
 429                 return;
 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, "malloc");
 437
 438 #define PASS(byte) {                                                    \
 439         memset(buf, byte, bsize);                                       \
 440         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 441                 wlen = len < bsize ? (int)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;
 456         }
 457
 458 err:    eval = 1;
 459         if (buf)
 460                 free(buf);
 461         warn("%s", file);
 462 }
 463
 464 int
 465 yes_or_no()
 466 {
 467         int ch, first;
 468         (void)fflush(stderr);
 469
 470         first = ch = getchar();
 471         while (ch != '\n' && ch != EOF)
 472                 ch = getchar();
 473         return (first == 'y' || first == 'Y');
 474 }
 475
 476 int
 477 checkdir(path)
 478         char *path;
 479 {
 480         if(!iflag)
 481                 return 1;       //if not interactive, process directory's contents
 482         (void)fprintf(stderr, "examine files in directory %s? ", path);
 483         return yes_or_no();
 484 }
 485
 486 int
 487 check(path, name, sp)
 488         char *path, *name;
 489         struct stat *sp;
 490 {
 491         char modep[15], *flagsp;
 492
 493         /* Check -i first. */
 494         if (iflag)
 495                 (void)fprintf(stderr, "remove %s? ", path);
 496         else {
 497                 /*
 498                  * If it's not a symbolic link and it's unwritable and we're
 499                  * talking to a terminal, ask.  Symbolic links are excluded
 500                  * because their permissions are meaningless.  Check stdin_ok
 501                  * first because we may not have stat'ed the file.
 502                  */
 503                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 504                     (!access(name, W_OK) &&
 505                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 506                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 507                         return (1);
 508                 strmode(sp->st_mode, modep);
 509                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 510                         err(1, NULL);
 511                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 512                     modep + 1, modep[9] == ' ' ? "" : " ",
 513                     user_from_uid(sp->st_uid, 0),
 514                     group_from_gid(sp->st_gid, 0),
 515                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 516                     path);
 517                 free(flagsp);
 518         }
 519         return yes_or_no();
 520 }
 521
 522
 523 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 524 void
 525 checkdot(argv)
 526         char **argv;
 527 {
 528         char *p, **save, **t;
 529         int complained;
 530
 531         complained = 0;
 532         for (t = argv; *t;) {
 533                 size_t len = strlen(*t);
 534                 char truncated[len];
 535
 536                 if ((p = strrchr(*t, '/')) != NULL) {
 537                         if (p[1] == '\0') { // trailing / -- treat as if not present
 538                                 strlcpy(truncated, *t, len);
 539                                 p = strrchr(truncated, '/');
 540                                 if (p) {
 541                                         ++p;
 542                                 } else {
 543                                         p = truncated;
 544                                 }
 545                         } else {
 546                                 ++p;
 547                         }
 548                 } else {
 549                         p = *t;
 550                 }
 551                 if (ISDOT(p)) {
 552                         if (!complained++)
 553                                 warnx("\".\" and \"..\" may not be removed");
 554                         eval = 1;
 555                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 556                                 continue;
 557                         t = save;
 558                 } else
 559                         ++t;
 560         }
 561 }
 562
 563 void
 564 usage()
 565 {
 566
 567         (void)fprintf(stderr, "%s\n%s\n",
 568             "usage: rm [-f | -i] [-dPRrvW] file ...",
 569             "       unlink file");
 570         exit(EX_USAGE);
 571 }