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 (5.5 kb)" 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-$(CONFIG_CHMOD) += chmod.o 21 22/* BB_AUDIT SUSv3 compliant */ 23/* BB_AUDIT GNU defects - unsupported long options. */ 24/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */ 25 26//usage:#define chmod_trivial_usage 27//usage: "[-R"IF_DESKTOP("cvf")"] MODE[,MODE]... FILE..." 28//usage:#define chmod_full_usage "\n\n" 29//usage: "MODE is octal number (bit pattern sstrwxrwxrwx) or [ugoa]{+|-|=}[rwxXst]" 30//usage: "\n" 31//next 4 options are the same for chmod/chown/chgrp: 32//usage: "\n -R Recurse" 33//usage: IF_DESKTOP( 34//usage: "\n -c List changed files" 35//usage: "\n -v Verbose" 36//usage: "\n -f Hide errors" 37//usage: ) 38//usage: 39//usage:#define chmod_example_usage 40//usage: "$ ls -l /tmp/foo\n" 41//usage: "-rw-rw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n" 42//usage: "$ chmod u+x /tmp/foo\n" 43//usage: "$ ls -l /tmp/foo\n" 44//usage: "-rwxrw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo*\n" 45//usage: "$ chmod 444 /tmp/foo\n" 46//usage: "$ ls -l /tmp/foo\n" 47//usage: "-r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n" 48 49#include "libbb.h" 50 51/* This is a NOEXEC applet. Be very careful! */ 52 53 54#define OPT_RECURSE (option_mask32 & 1) 55#define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0)) 56#define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0)) 57#define OPT_QUIET (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0)) 58#define OPT_STR "R" IF_DESKTOP("vcf") 59 60/* coreutils: 61 * chmod never changes the permissions of symbolic links; the chmod 62 * system call cannot change their permissions. This is not a problem 63 * since the permissions of symbolic links are never used. 64 * However, for each symbolic link listed on the command line, chmod changes 65 * the permissions of the pointed-to file. In contrast, chmod ignores 66 * symbolic links encountered during recursive directory traversals. 67 */ 68 69static int FAST_FUNC fileAction(struct recursive_state *state, 70 const char *fileName, 71 struct stat *statbuf) 72{ 73 mode_t newmode; 74 75 /* match coreutils behavior */ 76 if (state->depth == 0) { 77 /* statbuf holds lstat result, but we need stat (follow link) */ 78 if (stat(fileName, statbuf)) 79 goto err; 80 } else { /* depth > 0: skip links */ 81 if (S_ISLNK(statbuf->st_mode)) 82 return TRUE; 83 } 84 85 newmode = bb_parse_mode((char *)state->userData, statbuf->st_mode); 86 if (newmode == (mode_t)-1) 87 bb_error_msg_and_die("invalid mode '%s'", (char *)state->userData); 88 89 if (chmod(fileName, newmode) == 0) { 90 if (OPT_VERBOSE 91 || (OPT_CHANGED && statbuf->st_mode != newmode) 92 ) { 93 printf("mode of '%s' changed to %04o (%s)\n", fileName, 94 newmode & 07777, bb_mode_string(newmode)+1); 95 } 96 return TRUE; 97 } 98 err: 99 if (!OPT_QUIET) 100 bb_simple_perror_msg(fileName); 101 return FALSE; 102} 103 104int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 105int chmod_main(int argc UNUSED_PARAM, char **argv) 106{ 107 int retval = EXIT_SUCCESS; 108 char *arg, **argp; 109 char *smode; 110 111 /* Convert first encountered -r into ar, -w into aw etc 112 * so that getopt would not eat it */ 113 argp = argv; 114 while ((arg = *++argp)) { 115 /* Mode spec must be the first arg (sans -R etc) */ 116 /* (protect against mishandling e.g. "chmod 644 -r") */ 117 if (arg[0] != '-') { 118 arg = NULL; 119 break; 120 } 121 /* An option. Not a -- or valid option? */ 122 if (arg[1] && !strchr("-"OPT_STR, arg[1])) { 123 arg[0] = 'a'; 124 break; 125 } 126 } 127 128 /* Parse options */ 129 getopt32(argv, "^" OPT_STR "\0" "-2"); 130 argv += optind; 131 132 /* Restore option-like mode if needed */ 133 if (arg) arg[0] = '-'; 134 135 /* Ok, ready to do the deed now */ 136 smode = *argv++; 137 do { 138 if (!recursive_action(*argv, 139 OPT_RECURSE, // recurse 140 fileAction, // file action 141 fileAction, // dir action 142 smode) // user data 143 ) { 144 retval = EXIT_FAILURE; 145 } 146 } while (*++argv); 147 148 return retval; 149} 150 151/* 152Security: chmod is too important and too subtle. 153This is a test script (busybox chmod versus coreutils). 154Run it in empty directory. 155 156#!/bin/sh 157t1="/tmp/busybox chmod" 158t2="/usr/bin/chmod" 159create() { 160 rm -rf $1; mkdir $1 161 ( 162 cd $1 || exit 1 163 mkdir dir 164 >up 165 >file 166 >dir/file 167 ln -s dir linkdir 168 ln -s file linkfile 169 ln -s ../up dir/up 170 ) 171} 172tst() { 173 (cd test1; $t1 $1) 174 (cd test2; $t2 $1) 175 (cd test1; ls -lR) >out1 176 (cd test2; ls -lR) >out2 177 echo "chmod $1" >out.diff 178 if ! diff -u out1 out2 >>out.diff; then exit 1; fi 179 rm out.diff 180} 181echo "If script produced 'out.diff' file, then at least one testcase failed" 182create test1; create test2 183tst "a+w file" 184tst "a-w dir" 185tst "a+w linkfile" 186tst "a-w linkdir" 187tst "-R a+w file" 188tst "-R a-w dir" 189tst "-R a+w linkfile" 190tst "-R a-w linkdir" 191tst "a-r,a+x linkfile" 192*/ 193