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 68static 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 101int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 102int 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/* 151Security: chmod is too important and too subtle. 152This is a test script (busybox chmod versus coreutils). 153Run it in empty directory. 154 155#!/bin/sh 156t1="/tmp/busybox chmod" 157t2="/usr/bin/chmod" 158create() { 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} 171tst() { 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} 180echo "If script produced 'out.diff' file, then at least one testcase failed" 181create test1; create test2 182tst "a+w file" 183tst "a-w dir" 184tst "a+w linkfile" 185tst "a-w linkdir" 186tst "-R a+w file" 187tst "-R a-w dir" 188tst "-R a+w linkfile" 189tst "-R a-w linkdir" 190tst "a-r,a+x linkfile" 191*/ 192