blob: 80913f542a4e19c257e9bb6de705e8b2c7713676
| 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 | //config:config CHMOD |
| 13 | //config: bool "chmod" |
| 14 | //config: default y |
| 15 | //config: help |
| 16 | //config: chmod is used to change the access permission of files. |
| 17 | |
| 18 | //applet:IF_CHMOD(APPLET_NOEXEC(chmod, chmod, BB_DIR_BIN, BB_SUID_DROP, chmod)) |
| 19 | |
| 20 | //kbuild:lib-$(CONFIG_CHMOD) += chmod.o |
| 21 | |
| 22 | /* BB_AUDIT SUSv3 compliant */ |
| 23 | /* BB_AUDIT GNU defects - unsupported long options. */ |
| 24 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */ |
| 25 | |
| 26 | //usage:#define chmod_trivial_usage |
| 27 | //usage: "[-R"IF_DESKTOP("cvf")"] MODE[,MODE]... FILE..." |
| 28 | //usage:#define chmod_full_usage "\n\n" |
| 29 | //usage: "Each MODE is one or more of the letters ugoa, one of the\n" |
| 30 | //usage: "symbols +-= and one or more of the letters rwxst\n" |
| 31 | //usage: "\n -R Recurse" |
| 32 | //usage: IF_DESKTOP( |
| 33 | //usage: "\n -c List changed files" |
| 34 | //usage: "\n -v List all files" |
| 35 | //usage: "\n -f Hide errors" |
| 36 | //usage: ) |
| 37 | //usage: |
| 38 | //usage:#define chmod_example_usage |
| 39 | //usage: "$ ls -l /tmp/foo\n" |
| 40 | //usage: "-rw-rw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n" |
| 41 | //usage: "$ chmod u+x /tmp/foo\n" |
| 42 | //usage: "$ ls -l /tmp/foo\n" |
| 43 | //usage: "-rwxrw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo*\n" |
| 44 | //usage: "$ chmod 444 /tmp/foo\n" |
| 45 | //usage: "$ ls -l /tmp/foo\n" |
| 46 | //usage: "-r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n" |
| 47 | |
| 48 | #include "libbb.h" |
| 49 | |
| 50 | /* This is a NOEXEC applet. Be very careful! */ |
| 51 | |
| 52 | |
| 53 | #define OPT_RECURSE (option_mask32 & 1) |
| 54 | #define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0)) |
| 55 | #define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0)) |
| 56 | #define OPT_QUIET (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0)) |
| 57 | #define OPT_STR "R" IF_DESKTOP("vcf") |
| 58 | |
| 59 | /* coreutils: |
| 60 | * chmod never changes the permissions of symbolic links; the chmod |
| 61 | * system call cannot change their permissions. This is not a problem |
| 62 | * since the permissions of symbolic links are never used. |
| 63 | * However, for each symbolic link listed on the command line, chmod changes |
| 64 | * the permissions of the pointed-to file. In contrast, chmod ignores |
| 65 | * symbolic links encountered during recursive directory traversals. |
| 66 | */ |
| 67 | |
| 68 | static int FAST_FUNC fileAction(const char *fileName, struct stat *statbuf, void* param, int depth) |
| 69 | { |
| 70 | mode_t newmode; |
| 71 | |
| 72 | /* match coreutils behavior */ |
| 73 | if (depth == 0) { |
| 74 | /* statbuf holds lstat result, but we need stat (follow link) */ |
| 75 | if (stat(fileName, statbuf)) |
| 76 | goto err; |
| 77 | } else { /* depth > 0: skip links */ |
| 78 | if (S_ISLNK(statbuf->st_mode)) |
| 79 | return TRUE; |
| 80 | } |
| 81 | |
| 82 | newmode = bb_parse_mode((char *)param, statbuf->st_mode); |
| 83 | if (newmode == (mode_t)-1) |
| 84 | bb_error_msg_and_die("invalid mode '%s'", (char *)param); |
| 85 | |
| 86 | if (chmod(fileName, newmode) == 0) { |
| 87 | if (OPT_VERBOSE |
| 88 | || (OPT_CHANGED && statbuf->st_mode != newmode) |
| 89 | ) { |
| 90 | printf("mode of '%s' changed to %04o (%s)\n", fileName, |
| 91 | newmode & 07777, bb_mode_string(newmode)+1); |
| 92 | } |
| 93 | return TRUE; |
| 94 | } |
| 95 | err: |
| 96 | if (!OPT_QUIET) |
| 97 | bb_simple_perror_msg(fileName); |
| 98 | return FALSE; |
| 99 | } |
| 100 | |
| 101 | int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 102 | int chmod_main(int argc UNUSED_PARAM, char **argv) |
| 103 | { |
| 104 | int retval = EXIT_SUCCESS; |
| 105 | char *arg, **argp; |
| 106 | char *smode; |
| 107 | |
| 108 | /* Convert first encountered -r into ar, -w into aw etc |
| 109 | * so that getopt would not eat it */ |
| 110 | argp = argv; |
| 111 | while ((arg = *++argp)) { |
| 112 | /* Mode spec must be the first arg (sans -R etc) */ |
| 113 | /* (protect against mishandling e.g. "chmod 644 -r") */ |
| 114 | if (arg[0] != '-') { |
| 115 | arg = NULL; |
| 116 | break; |
| 117 | } |
| 118 | /* An option. Not a -- or valid option? */ |
| 119 | if (arg[1] && !strchr("-"OPT_STR, arg[1])) { |
| 120 | arg[0] = 'a'; |
| 121 | break; |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | /* Parse options */ |
| 126 | opt_complementary = "-2"; |
| 127 | getopt32(argv, ("-"OPT_STR) + 1); /* Reuse string */ |
| 128 | argv += optind; |
| 129 | |
| 130 | /* Restore option-like mode if needed */ |
| 131 | if (arg) arg[0] = '-'; |
| 132 | |
| 133 | /* Ok, ready to do the deed now */ |
| 134 | smode = *argv++; |
| 135 | do { |
| 136 | if (!recursive_action(*argv, |
| 137 | OPT_RECURSE, // recurse |
| 138 | fileAction, // file action |
| 139 | fileAction, // dir action |
| 140 | smode, // user data |
| 141 | 0) // depth |
| 142 | ) { |
| 143 | retval = EXIT_FAILURE; |
| 144 | } |
| 145 | } while (*++argv); |
| 146 | |
| 147 | return retval; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | Security: chmod is too important and too subtle. |
| 152 | This is a test script (busybox chmod versus coreutils). |
| 153 | Run it in empty directory. |
| 154 | |
| 155 | #!/bin/sh |
| 156 | t1="/tmp/busybox chmod" |
| 157 | t2="/usr/bin/chmod" |
| 158 | create() { |
| 159 | rm -rf $1; mkdir $1 |
| 160 | ( |
| 161 | cd $1 || exit 1 |
| 162 | mkdir dir |
| 163 | >up |
| 164 | >file |
| 165 | >dir/file |
| 166 | ln -s dir linkdir |
| 167 | ln -s file linkfile |
| 168 | ln -s ../up dir/up |
| 169 | ) |
| 170 | } |
| 171 | tst() { |
| 172 | (cd test1; $t1 $1) |
| 173 | (cd test2; $t2 $1) |
| 174 | (cd test1; ls -lR) >out1 |
| 175 | (cd test2; ls -lR) >out2 |
| 176 | echo "chmod $1" >out.diff |
| 177 | if ! diff -u out1 out2 >>out.diff; then exit 1; fi |
| 178 | rm out.diff |
| 179 | } |
| 180 | echo "If script produced 'out.diff' file, then at least one testcase failed" |
| 181 | create test1; create test2 |
| 182 | tst "a+w file" |
| 183 | tst "a-w dir" |
| 184 | tst "a+w linkfile" |
| 185 | tst "a-w linkdir" |
| 186 | tst "-R a+w file" |
| 187 | tst "-R a-w dir" |
| 188 | tst "-R a+w linkfile" |
| 189 | tst "-R a-w linkdir" |
| 190 | tst "a-r,a+x linkfile" |
| 191 | */ |
| 192 |