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 #include <locale.h>
  64
  65 #ifdef __APPLE__
  66 #include <removefile.h>
  67 #include <pwd.h>
  68 #include <grp.h>
  69 #include "get_compat.h"
  70
  71 #ifndef AT_REMOVEDIR_DATALESS
  72 #define AT_REMOVEDIR_DATALESS   0x0100  /* Remove a dataless directory without materializing first */
  73 #endif
  74 #else
  75 #define COMPAT_MODE(func, mode) 1
  76 #endif
  77
  78 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  79 uid_t uid;
  80
  81 int     check __P((char *, char *, struct stat *));
  82 int checkdir __P((char *));
  83 int             yes_or_no __P((void));
  84 void    checkdot __P((char **));
  85 void    rm_file __P((char **));
  86 void    rm_overwrite __P((char *, struct stat *));
  87 void    rm_tree __P((char **));
  88 void    usage __P((void));
  89
  90 /*
  91  * rm --
  92  *      This rm is different from historic rm's, but is expected to match
  93  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  94  *      has two specific effects now, ignore non-existent files and force
  95  *      file removal.
  96  */
  97 int
  98 main(argc, argv)
  99         int argc;
 100         char *argv[];
 101 {
 102         int ch, rflag;
 103         char *p;
 104
 105         if (argc < 1)
 106                 usage();
 107
 108         /*
 109          * Test for the special case where the utility is called as
 110          * "unlink", for which the functionality provided is greatly
 111          * simplified.
 112          */
 113         if ((p = rindex(argv[0], '/')) == NULL)
 114                 p = argv[0];
 115         else
 116                 ++p;
 117         uid = geteuid();
 118         if (strcmp(p, "unlink") == 0) {
 119                 if (argc == 2) {
 120                         rm_file(&argv[1]);
 121                         exit(eval);
 122                 } else
 123                         usage();
 124         }
 125
 126         Pflag = rflag = 0;
 127         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 128                 switch(ch) {
 129                 case 'd':
 130                         dflag = 1;
 131                         break;
 132                 case 'f':
 133                         fflag = 1;
 134                         iflag = 0;
 135                         break;
 136                 case 'i':
 137                         fflag = 0;
 138                         iflag = 1;
 139                         break;
 140                 case 'P':
 141                         Pflag = 1;
 142                         break;
 143                 case 'R':
 144                 case 'r':                       /* Compatibility. */
 145                         rflag = 1;
 146                         break;
 147                 case 'v':
 148                         vflag = 1;
 149                         break;
 150                 case 'W':
 151                         Wflag = 1;
 152                         break;
 153                 default:
 154                         usage();
 155                 }
 156         argc -= optind;
 157         argv += optind;
 158
 159         if (argc < 1) {
 160                 if (fflag)
 161                         return 0;
 162                 usage();
 163         }
 164
 165         checkdot(argv);
 166
 167         if (*argv) {
 168                 stdin_ok = isatty(STDIN_FILENO);
 169
 170                 if (rflag)
 171                         rm_tree(argv);
 172                 else
 173                         rm_file(argv);
 174         }
 175
 176         exit (eval);
 177 }
 178
 179 void
 180 rm_tree(argv)
 181         char **argv;
 182 {
 183         FTS *fts;
 184         FTSENT *p;
 185         int needstat;
 186         int flags;
 187         int rval;
 188         int wantConformance = COMPAT_MODE("bin/rm", "unix2003");
 189         /*
 190          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 191          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 192          */
 193         needstat = !uid || (!fflag && !iflag && stdin_ok);
 194
 195         /*
 196          * If the -i option is specified, the user can skip on the pre-order
 197          * visit.  The fts_number field flags skipped directories.
 198          */
 199 #define SKIPPED 1
 200
 201         flags = FTS_PHYSICAL;
 202         if (!needstat)
 203                 flags |= FTS_NOSTAT;
 204         if (Wflag)
 205                 flags |= FTS_WHITEOUT;
 206         if (!(fts = fts_open(argv, flags, NULL))) {
 207                 if (fflag && errno == ENOENT)
 208                         return;
 209                 err(1, NULL);
 210         }
 211         while ((p = fts_read(fts)) != NULL) {
 212                 switch (p->fts_info) {
 213                 case FTS_DNR:
 214                         if (!fflag || p->fts_errno != ENOENT) {
 215                                 warnx("%s: %s",
 216                                     p->fts_path, strerror(p->fts_errno));
 217                                 eval = 1;
 218                         }
 219                         continue;
 220                 case FTS_ERR:
 221                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 222                 case FTS_NS:
 223                         /*
 224                          * FTS_NS: assume that if can't stat the file, it
 225                          * can't be unlinked.
 226                          */
 227                         if (!needstat)
 228                                 break;
 229                         if (!fflag || p->fts_errno != ENOENT) {
 230                                 warnx("%s: %s",
 231                                     p->fts_path, strerror(p->fts_errno));
 232                                 eval = 1;
 233                         }
 234                         continue;
 235                 case FTS_D:
 236                         /* Pre-order: give user chance to skip. */
 237                         /* In conformance mode the user is prompted to skip processing the contents.
 238                          * Then the option to delete the dir is presented post-order */
 239                         if (!fflag &&
 240                                         ( (wantConformance && !checkdir(p->fts_path)) ||
 241                                           (!wantConformance && !check(p->fts_path, p->fts_accpath, p->fts_statp))
 242                                         )
 243                            ){
 244                                 (void)fts_set(fts, p, FTS_SKIP);
 245                                 p->fts_number = SKIPPED;
 246                         }
 247                         else if (!uid &&
 248                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 249                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 250                                  chflags(p->fts_accpath,
 251                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 252                                 goto err;
 253                         continue;
 254                 case FTS_DP:
 255                         /* Post-order: see if user skipped. */
 256                         if(p->fts_number == SKIPPED)/*in legacy mode, the user was prompted pre-order */
 257                                 continue;
 258                         else if(wantConformance)
 259                         {
 260                                 /* delete directory if force is on, or if user answers Y to prompt */
 261                                 if(fflag || check(p->fts_path, p->fts_accpath, p->fts_statp))
 262                                         break;
 263                                 else
 264                                         continue;
 265                         }
 266                         break;
 267                 default:
 268                         if (!fflag &&
 269                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 270                                 continue;
 271                 }
 272
 273                 rval = 0;
 274                 if (!uid &&
 275                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 276                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 277                         rval = chflags(p->fts_accpath,
 278                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 279                 if (rval == 0) {
 280                         /*
 281                          * If we can't read or search the directory, may still be
 282                          * able to remove it.  Don't print out the un{read,search}able
 283                          * message unless the remove fails.
 284                          */
 285                         switch (p->fts_info) {
 286                         case FTS_DP:
 287                         case FTS_DNR:
 288 #if __APPLE__
 289                                 rval = unlinkat(AT_FDCWD, p->fts_accpath, AT_REMOVEDIR_DATALESS);
 290                                 if (rval == -1 && errno == EINVAL) {
 291                                         /*
 292                                          * Kernel rejected AT_REMOVEDIR_DATALESS?
 293                                          * I guess we fall back on the painful
 294                                          * route (but it's better than failing).
 295                                          */
 296                                         rval = rmdir(p->fts_accpath);
 297                                 }
 298 #else
 299                                 rval = rmdir(p->fts_accpath);
 300 #endif
 301                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 302                                         if (rval == 0 && vflag)
 303                                                 (void)printf("%s\n",
 304                                                     p->fts_path);
 305                                         continue;
 306                                 }
 307                                 break;
 308
 309                         case FTS_W:
 310                                 rval = undelete(p->fts_accpath);
 311                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 312                                         if (vflag)
 313                                                 (void)printf("%s\n",
 314                                                     p->fts_path);
 315                                         continue;
 316                                 }
 317                                 break;
 318
 319                         default:
 320 #ifdef __APPLE__
 321                                 if (Pflag) {
 322                                         if (removefile(p->fts_accpath, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 323                                                 eval = rval = 1;
 324                                 } else
 325                                         rval = unlink(p->fts_accpath);
 326 #else  /* !__APPLE_ */
 327                                 if (Pflag)
 328                                         rm_overwrite(p->fts_accpath, NULL);
 329                                 rval = unlink(p->fts_accpath);
 330 #endif  /* __APPLE__ */
 331                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 332                                         if (rval == 0 && vflag)
 333                                                 (void)printf("%s\n",
 334                                                     p->fts_path);
 335                                         continue;
 336                                 }
 337                         }
 338                 }
 339 err:
 340                 warn("%s", p->fts_path);
 341                 eval = 1;
 342         }
 343         if (errno)
 344                 err(1, "fts_read");
 345         fts_close(fts);
 346 }
 347
 348 void
 349 rm_file(argv)
 350         char **argv;
 351 {
 352         struct stat sb;
 353         int rval;
 354         char *f;
 355
 356         /*
 357          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 358          * to remove a directory is an error, so must always stat the file.
 359          */
 360         while ((f = *argv++) != NULL) {
 361                 /* Assume if can't stat the file, can't unlink it. */
 362                 if (lstat(f, &sb)) {
 363                         if (Wflag) {
 364                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 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                 if (!uid &&
 387                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 388                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 389                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 390                 if (rval == 0) {
 391                         if (S_ISWHT(sb.st_mode))
 392                                 rval = undelete(f);
 393                         else if (S_ISDIR(sb.st_mode))
 394                                 rval = rmdir(f);
 395                         else {
 396 #ifdef __APPLE__
 397                                 if (Pflag) {
 398                                         if (removefile(f, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 399                                                 eval = rval = 1;
 400                                 } else
 401                                         rval = unlink(f);
 402 #else  /* !__APPLE__ */
 403                                 if (Pflag)
 404                                         rm_overwrite(f, &sb);
 405                                 rval = unlink(f);
 406 #endif  /* __APPLE__ */
 407                         }
 408                 }
 409                 if (rval && (!fflag || errno != ENOENT)) {
 410                         warn("%s", f);
 411                         eval = 1;
 412                 }
 413                 if (vflag && rval == 0)
 414                         (void)printf("%s\n", f);
 415         }
 416 }
 417
 418 /*
 419  * rm_overwrite --
 420  *      Overwrite the file 3 times with varying bit patterns.
 421  *
 422  * XXX
 423  * This is a cheap way to *really* delete files.  Note that only regular
 424  * files are deleted, directories (and therefore names) will remain.
 425  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 426  * System V file system).  In a logging file system, you'll have to have
 427  * kernel support.
 428  */
 429 void
 430 rm_overwrite(file, sbp)
 431         char *file;
 432         struct stat *sbp;
 433 {
 434         struct stat sb;
 435         struct statfs fsb;
 436         off_t len;
 437         int bsize, fd, wlen;
 438         char *buf = NULL;
 439
 440         if (sbp == NULL) {
 441                 if (lstat(file, &sb))
 442                         goto err;
 443                 sbp = &sb;
 444         }
 445         if (!S_ISREG(sbp->st_mode))
 446                 return;
 447         if ((fd = open(file, O_WRONLY, 0)) == -1)
 448                 goto err;
 449         if (fstatfs(fd, &fsb) == -1)
 450                 goto err;
 451         bsize = MAX(fsb.f_iosize, 1024);
 452         if ((buf = malloc(bsize)) == NULL)
 453                 err(1, "malloc");
 454
 455 #define PASS(byte) {                                                    \
 456         memset(buf, byte, bsize);                                       \
 457         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 458                 wlen = len < bsize ? (int)len : bsize;                  \
 459                 if (write(fd, buf, wlen) != wlen)                       \
 460                         goto err;                                       \
 461         }                                                               \
 462 }
 463         PASS(0xff);
 464         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 465                 goto err;
 466         PASS(0x00);
 467         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 468                 goto err;
 469         PASS(0xff);
 470         if (!fsync(fd) && !close(fd)) {
 471                 free(buf);
 472                 return;
 473         }
 474
 475 err:    eval = 1;
 476         if (buf)
 477                 free(buf);
 478         warn("%s", file);
 479 }
 480
 481 int
 482 yes_or_no()
 483 {
 484         int ch, first;
 485         char resp[] = {'\0', '\0'};
 486
 487         (void)fflush(stderr);
 488
 489         /* Load user specified locale */
 490         setlocale(LC_MESSAGES, "");
 491
 492         first = ch = getchar();
 493         while (ch != '\n' && ch != EOF)
 494                 ch = getchar();
 495
 496         /* only care about the first character */
 497         resp[0] = first;
 498
 499         return (rpmatch(resp) == 1);
 500 }
 501
 502 int
 503 checkdir(path)
 504         char *path;
 505 {
 506         if(!iflag)
 507                 return 1;       //if not interactive, process directory's contents
 508         (void)fprintf(stderr, "examine files in directory %s? ", path);
 509         return yes_or_no();
 510 }
 511
 512 int
 513 check(path, name, sp)
 514         char *path, *name;
 515         struct stat *sp;
 516 {
 517         char modep[15], *flagsp;
 518
 519         /* Check -i first. */
 520         if (iflag)
 521                 (void)fprintf(stderr, "remove %s? ", path);
 522         else {
 523                 /*
 524                  * If it's not a symbolic link and it's unwritable and we're
 525                  * talking to a terminal, ask.  Symbolic links are excluded
 526                  * because their permissions are meaningless.  Check stdin_ok
 527                  * first because we may not have stat'ed the file.
 528                  */
 529                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 530                     (!access(name, W_OK) &&
 531                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 532                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 533                         return (1);
 534                 strmode(sp->st_mode, modep);
 535                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 536                         err(1, NULL);
 537                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 538                     modep + 1, modep[9] == ' ' ? "" : " ",
 539                     user_from_uid(sp->st_uid, 0),
 540                     group_from_gid(sp->st_gid, 0),
 541                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 542                     path);
 543                 free(flagsp);
 544         }
 545         return yes_or_no();
 546 }
 547
 548
 549 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 550 void
 551 checkdot(argv)
 552         char **argv;
 553 {
 554         char *p, **save, **t;
 555         int complained;
 556
 557         complained = 0;
 558         for (t = argv; *t;) {
 559                 size_t len = strlen(*t);
 560                 char truncated[len];
 561
 562                 if ((p = strrchr(*t, '/')) != NULL) {
 563                         if (p[1] == '\0') { // one or more trailing / -- treat as if not present
 564                                 for (; (p > *t) && (p[-1] == '/');) {
 565                                         len--;
 566                                         p--;
 567                                 }
 568                                 strlcpy(truncated, *t, len);
 569                                 p = strrchr(truncated, '/');
 570                                 if (p) {
 571                                         ++p;
 572                                 } else {
 573                                         p = truncated;
 574                                 }
 575                         } else {
 576                                 ++p;
 577                         }
 578                 } else {
 579                         p = *t;
 580                 }
 581                 if (ISDOT(p)) {
 582                         if (!complained++)
 583                                 warnx("\".\" and \"..\" may not be removed");
 584                         eval = 1;
 585                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 586                                 continue;
 587                         t = save;
 588                 } else
 589                         ++t;
 590         }
 591 }
 592
 593 void
 594 usage()
 595 {
 596
 597         (void)fprintf(stderr, "%s\n%s\n",
 598             "usage: rm [-f | -i] [-dPRrvW] file ...",
 599             "       unlink file");
 600         exit(EX_USAGE);
 601 }