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 92 && (statbuf->st_mode & 07777) != (newmode & 07777)) 93 ) { 94 char modestr[12]; 95 printf("mode of '%s' changed to %04o (%s)\n", fileName, 96 newmode & 07777, bb_mode_string(modestr, newmode)+1); 97 } 98 return TRUE; 99 } 100 err: 101 if (!OPT_QUIET) 102 bb_simple_perror_msg(fileName); 103 return FALSE; 104} 105 106int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 107int chmod_main(int argc UNUSED_PARAM, char **argv) 108{ 109 int retval = EXIT_SUCCESS; 110 char *arg, **argp; 111 char *smode; 112 113 /* Convert first encountered -r into ar, -w into aw etc 114 * so that getopt would not eat it */ 115 argp = argv; 116 while ((arg = *++argp)) { 117 /* Mode spec must be the first arg (sans -R etc) */ 118 /* (protect against mishandling e.g. "chmod 644 -r") */ 119 if (arg[0] != '-') { 120 arg = NULL; 121 break; 122 } 123 /* An option. Not a -- or valid option? */ 124 if (arg[1] && !strchr("-"OPT_STR, arg[1])) { 125 arg[0] = 'a'; 126 break; 127 } 128 } 129 130 /* Parse options */ 131 getopt32(argv, "^" OPT_STR "\0" "-2"); 132 argv += optind; 133 134 /* Restore option-like mode if needed */ 135 if (arg) arg[0] = '-'; 136 137 /* Ok, ready to do the deed now */ 138 smode = *argv++; 139 do { 140 if (!recursive_action(*argv, 141 OPT_RECURSE, // recurse 142 fileAction, // file action 143 fileAction, // dir action 144 smode) // user data 145 ) { 146 retval = EXIT_FAILURE; 147 } 148 } while (*++argv); 149 150 return retval; 151} 152 153/* 154Security: chmod is too important and too subtle. 155This is a test script (busybox chmod versus coreutils). 156Run it in empty directory. 157 158#!/bin/sh 159t1="/tmp/busybox chmod" 160t2="/usr/bin/chmod" 161create() { 162 rm -rf $1; mkdir $1 163 ( 164 cd $1 || exit 1 165 mkdir dir 166 >up 167 >file 168 >dir/file 169 ln -s dir linkdir 170 ln -s file linkfile 171 ln -s ../up dir/up 172 ) 173} 174tst() { 175 (cd test1; $t1 $1) 176 (cd test2; $t2 $1) 177 (cd test1; ls -lR) >out1 178 (cd test2; ls -lR) >out2 179 echo "chmod $1" >out.diff 180 if ! diff -u out1 out2 >>out.diff; then exit 1; fi 181 rm out.diff 182} 183echo "If script produced 'out.diff' file, then at least one testcase failed" 184create test1; create test2 185tst "a+w file" 186tst "a-w dir" 187tst "a+w linkfile" 188tst "a-w linkdir" 189tst "-R a+w file" 190tst "-R a-w dir" 191tst "-R a+w linkfile" 192tst "-R a-w linkdir" 193tst "a-r,a+x linkfile" 194*/ 195