release/src/router/busybox/coreutils/chmod.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini chmod implementation for busybox
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Reworked by (C) 2002 Vladimir Oleynik <dzo@simtreas.ru>
   8  *  to correctly parse '-rwxgoa'
   9  *
  10  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  11  */
  12
  13 /* BB_AUDIT SUSv3 compliant */
  14 /* BB_AUDIT GNU defects - unsupported long options. */
  15 /* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
  16
  17 //usage:#define chmod_trivial_usage
  18 //usage:       "[-R"IF_DESKTOP("cvf")"] MODE[,MODE]... FILE..."
  19 //usage:#define chmod_full_usage "\n\n"
  20 //usage:       "Each MODE is one or more of the letters ugoa, one of the\n"
  21 //usage:       "symbols +-= and one or more of the letters rwxst\n"
  22 //usage:     "\n        -R      Recurse"
  23 //usage:        IF_DESKTOP(
  24 //usage:     "\n        -c      List changed files"
  25 //usage:     "\n        -v      List all files"
  26 //usage:     "\n        -f      Hide errors"
  27 //usage:        )
  28 //usage:
  29 //usage:#define chmod_example_usage
  30 //usage:       "$ ls -l /tmp/foo\n"
  31 //usage:       "-rw-rw-r--    1 root     root            0 Apr 12 18:25 /tmp/foo\n"
  32 //usage:       "$ chmod u+x /tmp/foo\n"
  33 //usage:       "$ ls -l /tmp/foo\n"
  34 //usage:       "-rwxrw-r--    1 root     root            0 Apr 12 18:25 /tmp/foo*\n"
  35 //usage:       "$ chmod 444 /tmp/foo\n"
  36 //usage:       "$ ls -l /tmp/foo\n"
  37 //usage:       "-r--r--r--    1 root     root            0 Apr 12 18:25 /tmp/foo\n"
  38
  39 #include "libbb.h"
  40
  41 /* This is a NOEXEC applet. Be very careful! */
  42
  43
  44 #define OPT_RECURSE (option_mask32 & 1)
  45 #define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0))
  46 #define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0))
  47 #define OPT_QUIET   (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0))
  48 #define OPT_STR     "R" IF_DESKTOP("vcf")
  49
  50 /* coreutils:
  51  * chmod never changes the permissions of symbolic links; the chmod
  52  * system call cannot change their permissions. This is not a problem
  53  * since the permissions of symbolic links are never used.
  54  * However, for each symbolic link listed on the command line, chmod changes
  55  * the permissions of the pointed-to file. In contrast, chmod ignores
  56  * symbolic links encountered during recursive directory traversals.
  57  */
  58
  59 static int FAST_FUNC fileAction(const char *fileName, struct stat *statbuf, void* param, int depth)
  60 {
  61         mode_t newmode;
  62
  63         /* match coreutils behavior */
  64         if (depth == 0) {
  65                 /* statbuf holds lstat result, but we need stat (follow link) */
  66                 if (stat(fileName, statbuf))
  67                         goto err;
  68         } else { /* depth > 0: skip links */
  69                 if (S_ISLNK(statbuf->st_mode))
  70                         return TRUE;
  71         }
  72         newmode = statbuf->st_mode;
  73
  74         if (!bb_parse_mode((char *)param, &newmode))
  75                 bb_error_msg_and_die("invalid mode '%s'", (char *)param);
  76
  77         if (chmod(fileName, newmode) == 0) {
  78                 if (OPT_VERBOSE
  79                  || (OPT_CHANGED && statbuf->st_mode != newmode)
  80                 ) {
  81                         printf("mode of '%s' changed to %04o (%s)\n", fileName,
  82                                 newmode & 07777, bb_mode_string(newmode)+1);
  83                 }
  84                 return TRUE;
  85         }
  86  err:
  87         if (!OPT_QUIET)
  88                 bb_simple_perror_msg(fileName);
  89         return FALSE;
  90 }
  91
  92 int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  93 int chmod_main(int argc UNUSED_PARAM, char **argv)
  94 {
  95         int retval = EXIT_SUCCESS;
  96         char *arg, **argp;
  97         char *smode;
  98
  99         /* Convert first encountered -r into ar, -w into aw etc
 100          * so that getopt would not eat it */
 101         argp = argv;
 102         while ((arg = *++argp)) {
 103                 /* Mode spec must be the first arg (sans -R etc) */
 104                 /* (protect against mishandling e.g. "chmod 644 -r") */
 105                 if (arg[0] != '-') {
 106                         arg = NULL;
 107                         break;
 108                 }
 109                 /* An option. Not a -- or valid option? */
 110                 if (arg[1] && !strchr("-"OPT_STR, arg[1])) {
 111                         arg[0] = 'a';
 112                         break;
 113                 }
 114         }
 115
 116         /* Parse options */
 117         opt_complementary = "-2";
 118         getopt32(argv, ("-"OPT_STR) + 1); /* Reuse string */
 119         argv += optind;
 120
 121         /* Restore option-like mode if needed */
 122         if (arg) arg[0] = '-';
 123
 124         /* Ok, ready to do the deed now */
 125         smode = *argv++;
 126         do {
 127                 if (!recursive_action(*argv,
 128                         OPT_RECURSE,    // recurse
 129                         fileAction,     // file action
 130                         fileAction,     // dir action
 131                         smode,          // user data
 132                         0)              // depth
 133                 ) {
 134                         retval = EXIT_FAILURE;
 135                 }
 136         } while (*++argv);
 137
 138         return retval;
 139 }
 140
 141 /*
 142 Security: chmod is too important and too subtle.
 143 This is a test script (busybox chmod versus coreutils).
 144 Run it in empty directory.
 145
 146 #!/bin/sh
 147 t1="/tmp/busybox chmod"
 148 t2="/usr/bin/chmod"
 149 create() {
 150     rm -rf $1; mkdir $1
 151     (
 152     cd $1 || exit 1
 153     mkdir dir
 154     >up
 155     >file
 156     >dir/file
 157     ln -s dir linkdir
 158     ln -s file linkfile
 159     ln -s ../up dir/up
 160     )
 161 }
 162 tst() {
 163     (cd test1; $t1 $1)
 164     (cd test2; $t2 $1)
 165     (cd test1; ls -lR) >out1
 166     (cd test2; ls -lR) >out2
 167     echo "chmod $1" >out.diff
 168     if ! diff -u out1 out2 >>out.diff; then exit 1; fi
 169     rm out.diff
 170 }
 171 echo "If script produced 'out.diff' file, then at least one testcase failed"
 172 create test1; create test2
 173 tst "a+w file"
 174 tst "a-w dir"
 175 tst "a+w linkfile"
 176 tst "a-w linkdir"
 177 tst "-R a+w file"
 178 tst "-R a-w dir"
 179 tst "-R a+w linkfile"
 180 tst "-R a-w linkdir"
 181 tst "a-r,a+x linkfile"
 182 */