busybox/coreutils/chmod.c

/* vi: set sw=4 ts=4: */
/*
 * Mini chmod implementation for busybox
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Reworked by (C) 2002 Vladimir Oleynik <dzo@simtreas.ru>
 *  to correctly parse '-rwxgoa'
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 compliant */
/* BB_AUDIT GNU defects - unsupported long options. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */

#include "libbb.h"

/* This is a NOEXEC applet. Be very careful! */


#define OPT_RECURSE (option_mask32 & 1)
#define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0))
#define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0))
#define OPT_QUIET   (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0))
#define OPT_STR     "R" IF_DESKTOP("vcf")

/* coreutils:
 * chmod never changes the permissions of symbolic links; the chmod
 * system call cannot change their permissions. This is not a problem
 * since the permissions of symbolic links are never used.
 * However, for each symbolic link listed on the command line, chmod changes
 * the permissions of the pointed-to file. In contrast, chmod ignores
 * symbolic links encountered during recursive directory traversals.
 */

static int FAST_FUNC fileAction(const char *fileName, struct stat *statbuf, void* param, int depth)
{
	mode_t newmode;

	/* match coreutils behavior */
	if (depth == 0) {
		/* statbuf holds lstat result, but we need stat (follow link) */
		if (stat(fileName, statbuf))
			goto err;
	} else { /* depth > 0: skip links */
		if (S_ISLNK(statbuf->st_mode))
			return TRUE;
	}
	newmode = statbuf->st_mode;

	if (!bb_parse_mode((char *)param, &newmode))
		bb_error_msg_and_die("invalid mode '%s'", (char *)param);

	if (chmod(fileName, newmode) == 0) {
		if (OPT_VERBOSE
		 || (OPT_CHANGED && statbuf->st_mode != newmode)
		) {
			printf("mode of '%s' changed to %04o (%s)\n", fileName,
				newmode & 07777, bb_mode_string(newmode)+1);
		}
		return TRUE;
	}
 err:
	if (!OPT_QUIET)
		bb_simple_perror_msg(fileName);
	return FALSE;
}

int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int chmod_main(int argc UNUSED_PARAM, char **argv)
{
	int retval = EXIT_SUCCESS;
	char *arg, **argp;
	char *smode;

	/* Convert first encountered -r into ar, -w into aw etc
	 * so that getopt would not eat it */
	argp = argv;
	while ((arg = *++argp)) {
		/* Mode spec must be the first arg (sans -R etc) */
		/* (protect against mishandling e.g. "chmod 644 -r") */
		if (arg[0] != '-') {
			arg = NULL;
			break;
		}
		/* An option. Not a -- or valid option? */
		if (arg[1] && !strchr("-"OPT_STR, arg[1])) {
			arg[0] = 'a';
			break;
		}
	}

	/* Parse options */
	opt_complementary = "-2";
	getopt32(argv, ("-"OPT_STR) + 1); /* Reuse string */
	argv += optind;

	/* Restore option-like mode if needed */
	if (arg) arg[0] = '-';

	/* Ok, ready to do the deed now */
	smode = *argv++;
	do {
		if (!recursive_action(*argv,
			OPT_RECURSE,    // recurse
			fileAction,     // file action
			fileAction,     // dir action
			smode,          // user data
			0)              // depth
		) {
			retval = EXIT_FAILURE;
		}
	} while (*++argv);

	return retval;
}

/*
Security: chmod is too important and too subtle.
This is a test script (busybox chmod versus coreutils).
Run it in empty directory.

#!/bin/sh
t1="/tmp/busybox chmod"
t2="/usr/bin/chmod"
create() {
    rm -rf $1; mkdir $1
    (
    cd $1 || exit 1
    mkdir dir
    >up
    >file
    >dir/file
    ln -s dir linkdir
    ln -s file linkfile
    ln -s ../up dir/up
    )
}
tst() {
    (cd test1; $t1 $1)
    (cd test2; $t2 $1)
    (cd test1; ls -lR) >out1
    (cd test2; ls -lR) >out2
    echo "chmod $1" >out.diff
    if ! diff -u out1 out2 >>out.diff; then exit 1; fi
    rm out.diff
}
echo "If script produced 'out.diff' file, then at least one testcase failed"
create test1; create test2
tst "a+w file"
tst "a-w dir"
tst "a+w linkfile"
tst "a-w linkdir"
tst "-R a+w file"
tst "-R a-w dir"
tst "-R a+w linkfile"
tst "-R a-w linkdir"
tst "a-r,a+x linkfile"
*/
1	niro	532	/* 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 tarball for details.
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	niro	816	#include "libbb.h"
18	niro	532
19	niro	816	/* This is a NOEXEC applet. Be very careful! */
20
21
22	niro	532	#define OPT_RECURSE (option_mask32 & 1)
23	niro	984	#define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0))
24			#define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0))
25			#define OPT_QUIET (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0))
26			#define OPT_STR "R" IF_DESKTOP("vcf")
27	niro	532
28			/* coreutils:
29			* chmod never changes the permissions of symbolic links; the chmod
30			* system call cannot change their permissions. This is not a problem
31			* since the permissions of symbolic links are never used.
32			* However, for each symbolic link listed on the command line, chmod changes
33			* the permissions of the pointed-to file. In contrast, chmod ignores
34			* symbolic links encountered during recursive directory traversals.
35			*/
36
37	niro	816	static int FAST_FUNC fileAction(const char fileName, struct stat statbuf, void* param, int depth)
38	niro	532	{
39			mode_t newmode;
40
41			/* match coreutils behavior */
42			if (depth == 0) {
43			/* statbuf holds lstat result, but we need stat (follow link) */
44			if (stat(fileName, statbuf))
45			goto err;
46			} else { /* depth > 0: skip links */
47			if (S_ISLNK(statbuf->st_mode))
48			return TRUE;
49			}
50			newmode = statbuf->st_mode;
51
52	niro	816	if (!bb_parse_mode((char *)param, &newmode))
53	niro	1123	bb_error_msg_and_die("invalid mode '%s'", (char *)param);
54	niro	532
55			if (chmod(fileName, newmode) == 0) {
56			if (OPT_VERBOSE
57			\|\| (OPT_CHANGED && statbuf->st_mode != newmode)
58			) {
59			printf("mode of '%s' changed to %04o (%s)\n", fileName,
60			newmode & 07777, bb_mode_string(newmode)+1);
61			}
62			return TRUE;
63			}
64			err:
65			if (!OPT_QUIET)
66	niro	816	bb_simple_perror_msg(fileName);
67	niro	532	return FALSE;
68			}
69
70	niro	816	int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
71			int chmod_main(int argc UNUSED_PARAM, char **argv)
72	niro	532	{
73			int retval = EXIT_SUCCESS;
74			char arg, *argp;
75			char *smode;
76
77			/* Convert first encountered -r into ar, -w into aw etc
78			* so that getopt would not eat it */
79			argp = argv;
80			while ((arg = *++argp)) {
81			/* Mode spec must be the first arg (sans -R etc) */
82			/* (protect against mishandling e.g. "chmod 644 -r") */
83			if (arg[0] != '-') {
84			arg = NULL;
85			break;
86			}
87			/* An option. Not a -- or valid option? */
88			if (arg[1] && !strchr("-"OPT_STR, arg[1])) {
89			arg[0] = 'a';
90			break;
91			}
92			}
93
94			/* Parse options */
95			opt_complementary = "-2";
96	niro	816	getopt32(argv, ("-"OPT_STR) + 1); /* Reuse string */
97	niro	532	argv += optind;
98
99			/* Restore option-like mode if needed */
100			if (arg) arg[0] = '-';
101
102			/* Ok, ready to do the deed now */
103			smode = *argv++;
104			do {
105			if (!recursive_action(*argv,
106			OPT_RECURSE, // recurse
107			fileAction, // file action
108			fileAction, // dir action
109			smode, // user data
110			0) // depth
111			) {
112			retval = EXIT_FAILURE;
113			}
114			} while (*++argv);
115
116			return retval;
117			}
118
119			/*
120			Security: chmod is too important and too subtle.
121			This is a test script (busybox chmod versus coreutils).
122	niro	816	Run it in empty directory.
123	niro	532
124			#!/bin/sh
125	niro	816	t1="/tmp/busybox chmod"
126			t2="/usr/bin/chmod"
127			create() {
128	niro	532	rm -rf $1; mkdir $1
129			(
130			cd $1 \|\| exit 1
131			mkdir dir
132			>up
133			>file
134			>dir/file
135			ln -s dir linkdir
136			ln -s file linkfile
137			ln -s ../up dir/up
138			)
139			}
140	niro	816	tst() {
141	niro	532	(cd test1; $t1 $1)
142			(cd test2; $t2 $1)
143			(cd test1; ls -lR) >out1
144			(cd test2; ls -lR) >out2
145			echo "chmod $1" >out.diff
146			if ! diff -u out1 out2 >>out.diff; then exit 1; fi
147	niro	816	rm out.diff
148	niro	532	}
149	niro	816	echo "If script produced 'out.diff' file, then at least one testcase failed"
150	niro	532	create test1; create test2
151			tst "a+w file"
152			tst "a-w dir"
153			tst "a+w linkfile"
154			tst "a-w linkdir"
155			tst "-R a+w file"
156			tst "-R a-w dir"
157			tst "-R a+w linkfile"
158			tst "-R a-w linkdir"
159			tst "a-r,a+x linkfile"
160			*/