1 /*-
2 * Copyright (c) 2008-2009 Robert N. M. Watson
3 * Copyright (c) 2011 Jonathan Anderson
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 /*
29 * Test routines to make sure a variety of system calls are or are not
30 * available in capability mode. The goal is not to see if they work, just
31 * whether or not they return the expected ECAPMODE.
32 */
33
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/capsicum.h>
37 #include <sys/errno.h>
38 #include <sys/mman.h>
39 #include <sys/mount.h>
40 #include <sys/socket.h>
41 #include <sys/stat.h>
42 #include <sys/wait.h>
43
44 #include <machine/sysarch.h>
45
46 #include <err.h>
47 #include <fcntl.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51
52 #include "cap_test.h"
53
54 #define CHECK_SYSCALL_VOID_NOT_ECAPMODE(syscall, ...) do { \
55 errno = 0; \
56 (void)syscall(__VA_ARGS__); \
57 if (errno == ECAPMODE) \
58 FAIL("capmode: %s failed with ECAPMODE", #syscall); \
59 } while (0)
60
61 int
test_capmode(void)62 test_capmode(void)
63 {
64 struct statfs statfs;
65 struct stat sb;
66 long sysarch_arg = 0;
67 int fd_close, fd_dir, fd_file, fd_socket, fd2[2];
68 int success = PASSED;
69 pid_t pid, wpid;
70 char ch;
71
72 /* Open some files to play with. */
73 REQUIRE(fd_file = open("/tmp/cap_capmode", O_RDWR|O_CREAT, 0644));
74 REQUIRE(fd_close = open("/dev/null", O_RDWR));
75 REQUIRE(fd_dir = open("/tmp", O_RDONLY));
76 REQUIRE(fd_socket = socket(PF_INET, SOCK_DGRAM, 0));
77
78 /* Enter capability mode. */
79 REQUIRE(cap_enter());
80
81 /*
82 * System calls that are not permitted in capability mode.
83 */
84 CHECK_CAPMODE(access, "/tmp/cap_capmode_access", F_OK);
85 CHECK_CAPMODE(acct, "/tmp/cap_capmode_acct");
86 CHECK_CAPMODE(bind, PF_INET, NULL, 0);
87 CHECK_CAPMODE(chdir, "/tmp/cap_capmode_chdir");
88 CHECK_CAPMODE(chflags, "/tmp/cap_capmode_chflags", UF_NODUMP);
89 CHECK_CAPMODE(chmod, "/tmp/cap_capmode_chmod", 0644);
90 CHECK_CAPMODE(chown, "/tmp/cap_capmode_chown", -1, -1);
91 CHECK_CAPMODE(chroot, "/tmp/cap_capmode_chroot");
92 CHECK_CAPMODE(connect, PF_INET, NULL, 0);
93 CHECK_CAPMODE(creat, "/tmp/cap_capmode_creat", 0644);
94 CHECK_CAPMODE(fchdir, fd_dir);
95 CHECK_CAPMODE(getfsstat, &statfs, sizeof(statfs), MNT_NOWAIT);
96 CHECK_CAPMODE(link, "/tmp/foo", "/tmp/bar");
97 CHECK_CAPMODE(lstat, "/tmp/cap_capmode_lstat", &sb);
98 CHECK_CAPMODE(mknod, "/tmp/capmode_mknod", 06440, 0);
99 CHECK_CAPMODE(mount, "procfs", "/not_mounted", 0, NULL);
100 CHECK_CAPMODE(open, "/dev/null", O_RDWR);
101 CHECK_CAPMODE(readlink, "/tmp/cap_capmode_readlink", NULL, 0);
102 CHECK_CAPMODE(revoke, "/tmp/cap_capmode_revoke");
103 CHECK_CAPMODE(stat, "/tmp/cap_capmode_stat", &sb);
104 CHECK_CAPMODE(symlink,
105 "/tmp/cap_capmode_symlink_from",
106 "/tmp/cap_capmode_symlink_to");
107 CHECK_CAPMODE(unlink, "/tmp/cap_capmode_unlink");
108 CHECK_CAPMODE(unmount, "/not_mounted", 0);
109
110 /*
111 * System calls that are permitted in capability mode.
112 */
113 CHECK_SYSCALL_SUCCEEDS(close, fd_close);
114 CHECK_SYSCALL_SUCCEEDS(dup, fd_file);
115 CHECK_SYSCALL_SUCCEEDS(fstat, fd_file, &sb);
116 CHECK_SYSCALL_SUCCEEDS(lseek, fd_file, 0, SEEK_SET);
117 CHECK_SYSCALL_SUCCEEDS(msync, &fd_file, 8192, MS_ASYNC);
118 CHECK_SYSCALL_SUCCEEDS(profil, NULL, 0, 0, 0);
119 CHECK_SYSCALL_SUCCEEDS(read, fd_file, &ch, sizeof(ch));
120 CHECK_SYSCALL_SUCCEEDS(recvfrom, fd_socket, NULL, 0, 0, NULL, NULL);
121 CHECK_SYSCALL_SUCCEEDS(setuid, getuid());
122 CHECK_SYSCALL_SUCCEEDS(write, fd_file, &ch, sizeof(ch));
123
124 /*
125 * These calls will fail for lack of e.g. a proper name to send to,
126 * but they are allowed in capability mode, so errno != ECAPMODE.
127 */
128 CHECK_NOT_CAPMODE(accept, fd_socket, NULL, NULL);
129 CHECK_NOT_CAPMODE(getpeername, fd_socket, NULL, NULL);
130 CHECK_NOT_CAPMODE(getsockname, fd_socket, NULL, NULL);
131 CHECK_NOT_CAPMODE(fchflags, fd_file, UF_NODUMP);
132 CHECK_NOT_CAPMODE(recvmsg, fd_socket, NULL, 0);
133 CHECK_NOT_CAPMODE(sendmsg, fd_socket, NULL, 0);
134 CHECK_NOT_CAPMODE(sendto, fd_socket, NULL, 0, 0, NULL, 0);
135
136 /*
137 * System calls which should be allowed in capability mode, but which
138 * don't return errors, and are thus difficult to check.
139 *
140 * We will try anyway, by checking errno.
141 */
142 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getegid);
143 CHECK_SYSCALL_VOID_NOT_ECAPMODE(geteuid);
144 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getgid);
145 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getpid);
146 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getppid);
147 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getuid);
148
149 /*
150 * Finally, tests for system calls that don't fit the pattern very well.
151 */
152 pid = fork();
153 if (pid >= 0) {
154 if (pid == 0) {
155 exit(0);
156 } else if (pid > 0) {
157 wpid = waitpid(pid, NULL, 0);
158 if (wpid < 0) {
159 if (errno != ECAPMODE)
160 FAIL("capmode:waitpid");
161 } else
162 FAIL("capmode:waitpid succeeded");
163 }
164 } else
165 FAIL("capmode:fork");
166
167 if (getlogin() == NULL)
168 FAIL("test_sycalls:getlogin %d", errno);
169
170 if (getsockname(fd_socket, NULL, NULL) < 0) {
171 if (errno == ECAPMODE)
172 FAIL("capmode:getsockname");
173 }
174
175 /* XXXRW: ktrace */
176
177 if (pipe(fd2) == 0) {
178 close(fd2[0]);
179 close(fd2[1]);
180 } else if (errno == ECAPMODE)
181 FAIL("capmode:pipe");
182
183 /* XXXRW: ptrace. */
184
185 /* sysarch() is, by definition, architecture-dependent */
186 #if defined (__amd64__) || defined (__i386__)
187 CHECK_CAPMODE(sysarch, I386_SET_IOPERM, &sysarch_arg);
188 #else
189 /* XXXJA: write a test for arm */
190 FAIL("capmode:no sysarch() test for current architecture");
191 #endif
192
193 /* XXXRW: No error return from sync(2) to test. */
194
195 return (success);
196 }
197