1 /*
2  * chcon -- change security context, based on coreutils-5.97-13
3  *
4  * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
5  *
6  * Copyright (C) 2006 - 2007 KaiGai Kohei <kaigai@kaigai.gr.jp>
7  *
8  * Licensed under GPLv2, see file LICENSE in this source tree.
9  */
10 //config:config CHCON
11 //config:	bool "chcon (8.9 kb)"
12 //config:	default n
13 //config:	depends on SELINUX
14 //config:	help
15 //config:	Enable support to change the security context of file.
16 
17 //applet:IF_CHCON(APPLET(chcon, BB_DIR_USR_BIN, BB_SUID_DROP))
18 
19 //kbuild:lib-$(CONFIG_CHCON) += chcon.o
20 
21 //usage:#define chcon_trivial_usage
22 //usage:       "[-chfRv] CONTEXT FILE..."
23 //usage:       "\n	chcon [-chfRv] [-u USER] [-r ROLE] [-l RANGE] [-t TYPE] FILE..."
24 //usage:	IF_LONG_OPTS(
25 //usage:       "\n	chcon [-chfRv] --reference=RFILE FILE..."
26 //usage:	)
27 //usage:
28 //usage:#define chcon_full_usage "\n\n"
29 //usage:       "Change the security context of FILEs to CONTEXT\n"
30 //usage:     "\n	-v	Verbose"
31 //usage:     "\n	-c	Report changes made"
32 //usage:     "\n	-h	Affect symlinks instead of their targets"
33 //usage:     "\n	-f	Suppress most error messages"
34 //usage:	IF_LONG_OPTS(
35 //usage:     "\n	--reference RFILE Use RFILE's group instead of using a CONTEXT value"
36 //usage:	)
37 //usage:     "\n	-u USER	Set user/role/type/range in the target security context"
38 //usage:     "\n	-r ROLE"
39 //usage:     "\n	-t TYPE"
40 //usage:     "\n	-l RANGE"
41 //usage:     "\n	-R	Recurse"
42 
43 #include <selinux/context.h>
44 
45 #include "libbb.h"
46 
47 #define OPT_RECURSIVE		(1<<0)	/* 'R' */
48 #define OPT_CHANHES		(1<<1)	/* 'c' */
49 #define OPT_NODEREFERENCE	(1<<2)	/* 'h' */
50 #define OPT_QUIET		(1<<3)	/* 'f' */
51 #define OPT_USER		(1<<4)	/* 'u' */
52 #define OPT_ROLE		(1<<5)	/* 'r' */
53 #define OPT_TYPE		(1<<6)	/* 't' */
54 #define OPT_RANGE		(1<<7)	/* 'l' */
55 #define OPT_VERBOSE		(1<<8)	/* 'v' */
56 #define OPT_REFERENCE		((1<<9) * ENABLE_LONG_OPTS)
57 #define OPT_COMPONENT_SPECIFIED	(OPT_USER | OPT_ROLE | OPT_TYPE | OPT_RANGE)
58 
59 static char *user = NULL;
60 static char *role = NULL;
61 static char *type = NULL;
62 static char *range = NULL;
63 static char *specified_context = NULL;
64 
change_filedir_context(struct recursive_state * state UNUSED_PARAM,const char * fname,struct stat * stbuf UNUSED_PARAM)65 static int FAST_FUNC change_filedir_context(struct recursive_state *state UNUSED_PARAM,
66 		const char *fname,
67 		struct stat *stbuf UNUSED_PARAM)
68 {
69 	context_t context = NULL;
70 	security_context_t file_context = NULL;
71 	security_context_t context_string;
72 	int rc = FALSE;
73 	int status = 0;
74 
75 	if (option_mask32 & OPT_NODEREFERENCE) {
76 		status = lgetfilecon(fname, &file_context);
77 	} else {
78 		status = getfilecon(fname, &file_context);
79 	}
80 	if (status < 0 && errno != ENODATA) {
81 		if ((option_mask32 & OPT_QUIET) == 0)
82 			bb_error_msg("can't obtain security context: %s", fname);
83 		goto skip;
84 	}
85 
86 	if (file_context == NULL && specified_context == NULL) {
87 		bb_error_msg("can't apply partial context to unlabeled file %s", fname);
88 		goto skip;
89 	}
90 
91 	if (specified_context == NULL) {
92 		context = set_security_context_component(file_context,
93 							user, role, type, range);
94 		if (!context) {
95 			bb_error_msg("can't compute security context from %s", file_context);
96 			goto skip;
97 		}
98 	} else {
99 		context = context_new(specified_context);
100 		if (!context) {
101 			bb_error_msg("invalid context: %s", specified_context);
102 			goto skip;
103 		}
104 	}
105 
106 	context_string = context_str(context);
107 	if (!context_string) {
108 		bb_simple_error_msg("can't obtain security context in text expression");
109 		goto skip;
110 	}
111 
112 	if (file_context == NULL || strcmp(context_string, file_context) != 0) {
113 		int fail;
114 
115 		if (option_mask32 & OPT_NODEREFERENCE) {
116 			fail = lsetfilecon(fname, context_string);
117 		} else {
118 			fail = setfilecon(fname, context_string);
119 		}
120 		if ((option_mask32 & OPT_VERBOSE) || ((option_mask32 & OPT_CHANHES) && !fail)) {
121 			printf(!fail
122 				? "context of %s changed to %s\n"
123 				: "can't change context of %s to %s\n",
124 				fname, context_string);
125 		}
126 		if (!fail) {
127 			rc = TRUE;
128 		} else if ((option_mask32 & OPT_QUIET) == 0) {
129 			bb_error_msg("can't change context of %s to %s",
130 					fname, context_string);
131 		}
132 	} else {
133 		if (option_mask32 & OPT_VERBOSE) {
134 			printf("context of %s retained as %s\n", fname, context_string);
135 		}
136 		rc = TRUE;
137 	}
138 skip:
139 	context_free(context);
140 	freecon(file_context);
141 
142 	return rc;
143 }
144 
145 #if ENABLE_LONG_OPTS
146 static const char chcon_longopts[] ALIGN1 =
147 	"recursive\0"      No_argument       "R"
148 	"changes\0"        No_argument       "c"
149 	"no-dereference\0" No_argument       "h"
150 	"silent\0"         No_argument       "f"
151 	"quiet\0"          No_argument       "f"
152 	"user\0"           Required_argument "u"
153 	"role\0"           Required_argument "r"
154 	"type\0"           Required_argument "t"
155 	"range\0"          Required_argument "l"
156 	"verbose\0"        No_argument       "v"
157 	"reference\0"      Required_argument "\xff" /* no short option */
158 	;
159 #endif
160 
161 int chcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
chcon_main(int argc UNUSED_PARAM,char ** argv)162 int chcon_main(int argc UNUSED_PARAM, char **argv)
163 {
164 	char *reference_file;
165 	char *fname;
166 	int i, errors = 0;
167 
168 	getopt32long(argv, "^"
169 		"Rchfu:r:t:l:v"
170 		"\0"
171 		"-1" /* at least 1 arg */
172 		":?" /* error if exclusivity constraints are violated */
173 #if ENABLE_LONG_OPTS
174 		":\xff--urtl:u--\xff:r--\xff:t--\xff:l--\xff"
175 #endif
176 		":f--v:v--f"  /* 'verbose' and 'quiet' are exclusive */
177 		, chcon_longopts,
178 		&user, &role, &type, &range, &reference_file
179 	);
180 	argv += optind;
181 
182 #if ENABLE_LONG_OPTS
183 	if (option_mask32 & OPT_REFERENCE) {
184 		/* FIXME: lgetfilecon() should be used when '-h' is specified.
185 		 * But current implementation follows the original one. */
186 		if (getfilecon(reference_file, &specified_context) < 0)
187 			bb_perror_msg_and_die("getfilecon('%s') failed", reference_file);
188 	} else
189 #endif
190 	if ((option_mask32 & OPT_COMPONENT_SPECIFIED) == 0) {
191 		specified_context = *argv++;
192 		/* specified_context is never NULL -
193 		 * "-1" in opt_complementary prevents this. */
194 		if (!argv[0])
195 			bb_simple_error_msg_and_die("too few arguments");
196 	}
197 
198 	for (i = 0; (fname = argv[i]) != NULL; i++) {
199 		int fname_len = strlen(fname);
200 		while (fname_len > 1 && fname[fname_len - 1] == '/')
201 			fname_len--;
202 		fname[fname_len] = '\0';
203 
204 		if (recursive_action(fname,
205 					((option_mask32 & OPT_RECURSIVE) ? ACTION_RECURSE : 0),
206 					change_filedir_context,
207 					change_filedir_context,
208 					NULL) != TRUE)
209 			errors = 1;
210 	}
211 	return errors;
212 }
213