xref: /freebsd/lib/libveriexec/veriexec_check.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011, 2012, 2013, 2015, Juniper Networks, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/types.h>
30 #include <sys/errno.h>
31 #include <sys/mac.h>
32 #include <sys/stat.h>
33 
34 #include <stdio.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <paths.h>
39 
40 #include <security/mac_veriexec/mac_veriexec.h>
41 
42 #include "libveriexec.h"
43 
44 
45 static int
46 check_fd_mode(int fd, unsigned int mask)
47 {
48 	struct stat st;
49 
50 	if (fstat(fd, &st) < 0)
51 		return errno;
52 
53 	if ((st.st_mode & mask) == 0)
54 		return EAUTH;
55 
56 	return 0;
57 }
58 
59 int
60 veriexec_check_fd_mode(int fd, unsigned int mask)
61 {
62 	int error;
63 
64 	if (fd < 0) {
65 		errno = EINVAL;
66 		return -1;
67 	}
68 
69 	error = mac_syscall(MAC_VERIEXEC_NAME, MAC_VERIEXEC_CHECK_FD_SYSCALL,
70 	    (void *)(intptr_t)fd);
71 	if (error == -1) {
72 		switch (errno) {
73 		case ENOSYS:	/* veriexec not loaded */
74 			error = 0;	/* ignore */
75 			break;
76 		}
77 	}
78 	if (mask && error == 0)
79 	    error = check_fd_mode(fd, mask);
80 
81 	return (error);
82 }
83 
84 int
85 veriexec_check_path_mode(const char *file, unsigned int mask)
86 {
87 	int error;
88 
89 	if (!file) {
90 		errno = EINVAL;
91 		return -1;
92 	}
93 
94 	if (mask) {
95 		int fd;
96 
97 		if ((fd = open(file, O_RDONLY)) < 0)
98 			return errno;
99 
100 		error = veriexec_check_fd_mode(fd, mask);
101 		close(fd);
102 		return error;
103 	}
104 
105 	error = mac_syscall(MAC_VERIEXEC_NAME, MAC_VERIEXEC_CHECK_PATH_SYSCALL,
106 	    __DECONST(void *, file));
107 	if (error == -1) {
108 		switch (errno) {
109 		case ENOSYS:	/* veriexec not loaded */
110 			error = 0;	/* ignore */
111 			break;
112 		}
113 	}
114 	return (error);
115 }
116 
117 int
118 veriexec_check_fd(int fd)
119 {
120 	return veriexec_check_fd_mode(fd, 0);
121 }
122 
123 int
124 veriexec_check_path(const char *file)
125 {
126 	return veriexec_check_path_mode(file, 0);
127 }
128 
129 #if defined(MAIN) || defined(UNIT_TEST)
130 int
131 main(int argc __unused, char *argv[] __unused)
132 {
133 	int error;
134 	int rc = 0;
135 
136 	while (*++argv) {
137 		error = veriexec_check_path(*argv);
138 		if (error == -1) {
139 			rc = 1;
140 			warn("%s", *argv);
141 		}
142 	}
143 	exit(rc);
144 }
145 #endif
146