file_cmds/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 #if __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 140000
  79 #include "rpmatch.c"
  80 #endif
  81
  82 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  83 uid_t uid;
  84
  85 int     check __P((char *, char *, struct stat *));
  86 int checkdir __P((char *));
  87 int             yes_or_no __P((void));
  88 void    checkdot __P((char **));
  89 void    rm_file __P((char **));
  90 void    rm_overwrite __P((char *, struct stat *));
  91 void    rm_tree __P((char **));
  92 void    usage __P((void));
  93
  94 /*
  95  * rm --
  96  *      This rm is different from historic rm's, but is expected to match
  97  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  98  *      has two specific effects now, ignore non-existent files and force
  99  *      file removal.
 100  */
 101 int
 102 main(argc, argv)
 103         int argc;
 104         char *argv[];
 105 {
 106         int ch, rflag;
 107         char *p;
 108
 109         if (argc < 1)
 110                 usage();
 111
 112         /*
 113          * Test for the special case where the utility is called as
 114          * "unlink", for which the functionality provided is greatly
 115          * simplified.
 116          */
 117         if ((p = rindex(argv[0], '/')) == NULL)
 118                 p = argv[0];
 119         else
 120                 ++p;
 121         uid = geteuid();
 122         if (strcmp(p, "unlink") == 0) {
 123                 if (argc == 2) {
 124                         rm_file(&argv[1]);
 125                         exit(eval);
 126                 } else
 127                         usage();
 128         }
 129
 130         Pflag = rflag = 0;
 131         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 132                 switch(ch) {
 133                 case 'd':
 134                         dflag = 1;
 135                         break;
 136                 case 'f':
 137                         fflag = 1;
 138                         iflag = 0;
 139                         break;
 140                 case 'i':
 141                         fflag = 0;
 142                         iflag = 1;
 143                         break;
 144                 case 'P':
 145                         Pflag = 1;
 146                         break;
 147                 case 'R':
 148                 case 'r':                       /* Compatibility. */
 149                         rflag = 1;
 150                         break;
 151                 case 'v':
 152                         vflag = 1;
 153                         break;
 154                 case 'W':
 155                         Wflag = 1;
 156                         break;
 157                 default:
 158                         usage();
 159                 }
 160         argc -= optind;
 161         argv += optind;
 162
 163         if (argc < 1) {
 164                 if (fflag)
 165                         return 0;
 166                 usage();
 167         }
 168
 169         checkdot(argv);
 170
 171         if (*argv) {
 172                 stdin_ok = isatty(STDIN_FILENO);
 173
 174                 if (rflag)
 175                         rm_tree(argv);
 176                 else
 177                         rm_file(argv);
 178         }
 179
 180         exit (eval);
 181 }
 182
 183 void
 184 rm_tree(argv)
 185         char **argv;
 186 {
 187         FTS *fts;
 188         FTSENT *p;
 189         int needstat;
 190         int flags;
 191         int rval;
 192         int wantConformance = COMPAT_MODE("bin/rm", "unix2003");
 193         /*
 194          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 195          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 196          */
 197         needstat = !uid || (!fflag && !iflag && stdin_ok);
 198
 199         /*
 200          * If the -i option is specified, the user can skip on the pre-order
 201          * visit.  The fts_number field flags skipped directories.
 202          */
 203 #define SKIPPED 1
 204
 205         flags = FTS_PHYSICAL;
 206         if (!needstat)
 207                 flags |= FTS_NOSTAT;
 208         if (Wflag)
 209                 flags |= FTS_WHITEOUT;
 210         if (!(fts = fts_open(argv, flags, NULL))) {
 211                 if (fflag && errno == ENOENT)
 212                         return;
 213                 err(1, NULL);
 214         }
 215         while ((p = fts_read(fts)) != NULL) {
 216                 switch (p->fts_info) {
 217                 case FTS_DNR:
 218                         if (!fflag || p->fts_errno != ENOENT) {
 219                                 warnx("%s: %s",
 220                                     p->fts_path, strerror(p->fts_errno));
 221                                 eval = 1;
 222                         }
 223                         continue;
 224                 case FTS_ERR:
 225                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 226                 case FTS_NS:
 227                         /*
 228                          * FTS_NS: assume that if can't stat the file, it
 229                          * can't be unlinked.
 230                          */
 231                         if (!needstat)
 232                                 break;
 233                         if (!fflag || p->fts_errno != ENOENT) {
 234                                 warnx("%s: %s",
 235                                     p->fts_path, strerror(p->fts_errno));
 236                                 eval = 1;
 237                         }
 238                         continue;
 239                 case FTS_D:
 240                         /* Pre-order: give user chance to skip. */
 241                         /* In conformance mode the user is prompted to skip processing the contents.
 242                          * Then the option to delete the dir is presented post-order */
 243                         if (!fflag &&
 244                                         ( (wantConformance && !checkdir(p->fts_path)) ||
 245                                           (!wantConformance && !check(p->fts_path, p->fts_accpath, p->fts_statp))
 246                                         )
 247                            ){
 248                                 (void)fts_set(fts, p, FTS_SKIP);
 249                                 p->fts_number = SKIPPED;
 250                         }
 251                         else if (!uid &&
 252                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 253                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 254                                  chflags(p->fts_accpath,
 255                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 256                                 goto err;
 257                         continue;
 258                 case FTS_DP:
 259                         /* Post-order: see if user skipped. */
 260                         if(p->fts_number == SKIPPED)/*in legacy mode, the user was prompted pre-order */
 261                                 continue;
 262                         else if(wantConformance)
 263                         {
 264                                 /* delete directory if force is on, or if user answers Y to prompt */
 265                                 if(fflag || check(p->fts_path, p->fts_accpath, p->fts_statp))
 266                                         break;
 267                                 else
 268                                         continue;
 269                         }
 270                         break;
 271                 default:
 272                         if (!fflag &&
 273                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 274                                 continue;
 275                 }
 276
 277                 rval = 0;
 278                 if (!uid &&
 279                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 280                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 281                         rval = chflags(p->fts_accpath,
 282                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 283                 if (rval == 0) {
 284                         /*
 285                          * If we can't read or search the directory, may still be
 286                          * able to remove it.  Don't print out the un{read,search}able
 287                          * message unless the remove fails.
 288                          */
 289                         switch (p->fts_info) {
 290                         case FTS_DP:
 291                         case FTS_DNR:
 292 #if __APPLE__
 293                                 rval = unlinkat(AT_FDCWD, p->fts_accpath, AT_REMOVEDIR_DATALESS);
 294                                 if (rval == -1 && errno == EINVAL) {
 295                                         /*
 296                                          * Kernel rejected AT_REMOVEDIR_DATALESS?
 297                                          * I guess we fall back on the painful
 298                                          * route (but it's better than failing).
 299                                          */
 300                                         rval = rmdir(p->fts_accpath);
 301                                 }
 302 #else
 303                                 rval = rmdir(p->fts_accpath);
 304 #endif
 305                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 306                                         if (rval == 0 && vflag)
 307                                                 (void)printf("%s\n",
 308                                                     p->fts_path);
 309                                         continue;
 310                                 }
 311                                 break;
 312
 313                         case FTS_W:
 314                                 rval = undelete(p->fts_accpath);
 315                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 316                                         if (vflag)
 317                                                 (void)printf("%s\n",
 318                                                     p->fts_path);
 319                                         continue;
 320                                 }
 321                                 break;
 322
 323                         default:
 324 #ifdef __APPLE__
 325                                 if (Pflag) {
 326                                         if (removefile(p->fts_accpath, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 327                                                 eval = rval = 1;
 328                                 } else
 329                                         rval = unlink(p->fts_accpath);
 330 #else  /* !__APPLE_ */
 331                                 if (Pflag)
 332                                         rm_overwrite(p->fts_accpath, NULL);
 333                                 rval = unlink(p->fts_accpath);
 334 #endif  /* __APPLE__ */
 335                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 336                                         if (rval == 0 && vflag)
 337                                                 (void)printf("%s\n",
 338                                                     p->fts_path);
 339                                         continue;
 340                                 }
 341                         }
 342                 }
 343 err:
 344                 warn("%s", p->fts_path);
 345                 eval = 1;
 346         }
 347         if (errno)
 348                 err(1, "fts_read");
 349         fts_close(fts);
 350 }
 351
 352 void
 353 rm_file(argv)
 354         char **argv;
 355 {
 356         struct stat sb;
 357         int rval;
 358         char *f;
 359
 360         /*
 361          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 362          * to remove a directory is an error, so must always stat the file.
 363          */
 364         while ((f = *argv++) != NULL) {
 365                 /* Assume if can't stat the file, can't unlink it. */
 366                 if (lstat(f, &sb)) {
 367                         if (Wflag) {
 368                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 369                         } else {
 370                                 if (!fflag || errno != ENOENT) {
 371                                         warn("%s", f);
 372                                         eval = 1;
 373                                 }
 374                                 continue;
 375                         }
 376                 } else if (Wflag) {
 377                         warnx("%s: %s", f, strerror(EEXIST));
 378                         eval = 1;
 379                         continue;
 380                 }
 381
 382                 if (S_ISDIR(sb.st_mode) && !dflag) {
 383                         warnx("%s: is a directory", f);
 384                         eval = 1;
 385                         continue;
 386                 }
 387                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 388                         continue;
 389                 rval = 0;
 390                 if (!uid &&
 391                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 392                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 393                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 394                 if (rval == 0) {
 395                         if (S_ISWHT(sb.st_mode))
 396                                 rval = undelete(f);
 397                         else if (S_ISDIR(sb.st_mode))
 398                                 rval = rmdir(f);
 399                         else {
 400 #ifdef __APPLE__
 401                                 if (Pflag) {
 402                                         if (removefile(f, NULL, REMOVEFILE_SECURE_7_PASS)) /* overwrites and unlinks */
 403                                                 eval = rval = 1;
 404                                 } else
 405                                         rval = unlink(f);
 406 #else  /* !__APPLE__ */
 407                                 if (Pflag)
 408                                         rm_overwrite(f, &sb);
 409                                 rval = unlink(f);
 410 #endif  /* __APPLE__ */
 411                         }
 412                 }
 413                 if (rval && (!fflag || errno != ENOENT)) {
 414                         warn("%s", f);
 415                         eval = 1;
 416                 }
 417                 if (vflag && rval == 0)
 418                         (void)printf("%s\n", f);
 419         }
 420 }
 421
 422 /*
 423  * rm_overwrite --
 424  *      Overwrite the file 3 times with varying bit patterns.
 425  *
 426  * XXX
 427  * This is a cheap way to *really* delete files.  Note that only regular
 428  * files are deleted, directories (and therefore names) will remain.
 429  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 430  * System V file system).  In a logging file system, you'll have to have
 431  * kernel support.
 432  */
 433 void
 434 rm_overwrite(file, sbp)
 435         char *file;
 436         struct stat *sbp;
 437 {
 438         struct stat sb;
 439         struct statfs fsb;
 440         off_t len;
 441         int bsize, fd, wlen;
 442         char *buf = NULL;
 443
 444         if (sbp == NULL) {
 445                 if (lstat(file, &sb))
 446                         goto err;
 447                 sbp = &sb;
 448         }
 449         if (!S_ISREG(sbp->st_mode))
 450                 return;
 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, "malloc");
 458
 459 #define PASS(byte) {                                                    \
 460         memset(buf, byte, bsize);                                       \
 461         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 462                 wlen = len < bsize ? (int)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;
 477         }
 478
 479 err:    eval = 1;
 480         if (buf)
 481                 free(buf);
 482         warn("%s", file);
 483 }
 484
 485 int
 486 yes_or_no()
 487 {
 488         int ch, first;
 489         char resp[] = {'\0', '\0'};
 490
 491         (void)fflush(stderr);
 492
 493         /* Load user specified locale */
 494         setlocale(LC_MESSAGES, "");
 495
 496         first = ch = getchar();
 497         while (ch != '\n' && ch != EOF)
 498                 ch = getchar();
 499
 500         /* only care about the first character */
 501         resp[0] = first;
 502
 503         return (rpmatch(resp) == 1);
 504 }
 505
 506 int
 507 checkdir(path)
 508         char *path;
 509 {
 510         if(!iflag)
 511                 return 1;       //if not interactive, process directory's contents
 512         (void)fprintf(stderr, "examine files in directory %s? ", path);
 513         return yes_or_no();
 514 }
 515
 516 int
 517 check(path, name, sp)
 518         char *path, *name;
 519         struct stat *sp;
 520 {
 521         char modep[15], *flagsp;
 522
 523         /* Check -i first. */
 524         if (iflag)
 525                 (void)fprintf(stderr, "remove %s? ", path);
 526         else {
 527                 /*
 528                  * If it's not a symbolic link and it's unwritable and we're
 529                  * talking to a terminal, ask.  Symbolic links are excluded
 530                  * because their permissions are meaningless.  Check stdin_ok
 531                  * first because we may not have stat'ed the file.
 532                  */
 533                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 534                     (!access(name, W_OK) &&
 535                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 536                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 537                         return (1);
 538                 strmode(sp->st_mode, modep);
 539                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 540                         err(1, NULL);
 541                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 542                     modep + 1, modep[9] == ' ' ? "" : " ",
 543                     user_from_uid(sp->st_uid, 0),
 544                     group_from_gid(sp->st_gid, 0),
 545                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 546                     path);
 547                 free(flagsp);
 548         }
 549         return yes_or_no();
 550 }
 551
 552
 553 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 554 void
 555 checkdot(argv)
 556         char **argv;
 557 {
 558         char *p, **save, **t;
 559         int complained;
 560
 561         complained = 0;
 562         for (t = argv; *t;) {
 563                 size_t len = strlen(*t);
 564                 char truncated[len];
 565
 566                 if ((p = strrchr(*t, '/')) != NULL) {
 567                         if (p[1] == '\0') { // one or more trailing / -- treat as if not present
 568                                 for (; (p > *t) && (p[-1] == '/');) {
 569                                         len--;
 570                                         p--;
 571                                 }
 572                                 strlcpy(truncated, *t, len);
 573                                 p = strrchr(truncated, '/');
 574                                 if (p) {
 575                                         ++p;
 576                                 } else {
 577                                         p = truncated;
 578                                 }
 579                         } else {
 580                                 ++p;
 581                         }
 582                 } else {
 583                         p = *t;
 584                 }
 585                 if (ISDOT(p)) {
 586                         if (!complained++)
 587                                 warnx("\".\" and \"..\" may not be removed");
 588                         eval = 1;
 589                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 590                                 continue;
 591                         t = save;
 592                 } else
 593                         ++t;
 594         }
 595 }
 596
 597 void
 598 usage()
 599 {
 600
 601         (void)fprintf(stderr, "%s\n%s\n",
 602             "usage: rm [-f | -i] [-dPRrvW] file ...",
 603             "       unlink file");
 604         exit(EX_USAGE);
 605 }