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/param.h>
35 #include <sys/capsicum.h>
36 #include <sys/errno.h>
37 #include <sys/mman.h>
38 #include <sys/mount.h>
39 #include <sys/socket.h>
40 #include <sys/stat.h>
41 #include <sys/wait.h>
42
43 #include <machine/sysarch.h>
44
45 #include <err.h>
46 #include <fcntl.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50
51 #include "cap_test.h"
52
53 #define CHECK_SYSCALL_VOID_NOT_ECAPMODE(syscall, ...) do { \
54 errno = 0; \
55 (void)syscall(__VA_ARGS__); \
56 if (errno == ECAPMODE) \
57 FAIL("capmode: %s failed with ECAPMODE", #syscall); \
58 } while (0)
59
60 int
test_capmode(void)61 test_capmode(void)
62 {
63 struct statfs statfs;
64 struct stat sb;
65 long sysarch_arg = 0;
66 int fd_close, fd_dir, fd_file, fd_socket, fd2[2];
67 int success = PASSED;
68 pid_t pid, wpid;
69 char ch;
70
71 /* Open some files to play with. */
72 REQUIRE(fd_file = open("/tmp/cap_capmode", O_RDWR|O_CREAT, 0644));
73 REQUIRE(fd_close = open("/dev/null", O_RDWR));
74 REQUIRE(fd_dir = open("/tmp", O_RDONLY));
75 REQUIRE(fd_socket = socket(PF_INET, SOCK_DGRAM, 0));
76
77 /* Enter capability mode. */
78 REQUIRE(cap_enter());
79
80 /*
81 * System calls that are not permitted in capability mode.
82 */
83 CHECK_CAPMODE(access, "/tmp/cap_capmode_access", F_OK);
84 CHECK_CAPMODE(acct, "/tmp/cap_capmode_acct");
85 CHECK_CAPMODE(bind, PF_INET, NULL, 0);
86 CHECK_CAPMODE(chdir, "/tmp/cap_capmode_chdir");
87 CHECK_CAPMODE(chflags, "/tmp/cap_capmode_chflags", UF_NODUMP);
88 CHECK_CAPMODE(chmod, "/tmp/cap_capmode_chmod", 0644);
89 CHECK_CAPMODE(chown, "/tmp/cap_capmode_chown", -1, -1);
90 CHECK_CAPMODE(chroot, "/tmp/cap_capmode_chroot");
91 CHECK_CAPMODE(connect, PF_INET, NULL, 0);
92 CHECK_CAPMODE(creat, "/tmp/cap_capmode_creat", 0644);
93 CHECK_CAPMODE(fchdir, fd_dir);
94 CHECK_CAPMODE(getfsstat, &statfs, sizeof(statfs), MNT_NOWAIT);
95 CHECK_CAPMODE(link, "/tmp/foo", "/tmp/bar");
96 CHECK_CAPMODE(lstat, "/tmp/cap_capmode_lstat", &sb);
97 CHECK_CAPMODE(mknod, "/tmp/capmode_mknod", 06440, 0);
98 CHECK_CAPMODE(mount, "procfs", "/not_mounted", 0, NULL);
99 CHECK_CAPMODE(open, "/dev/null", O_RDWR);
100 CHECK_CAPMODE(readlink, "/tmp/cap_capmode_readlink", NULL, 0);
101 CHECK_CAPMODE(revoke, "/tmp/cap_capmode_revoke");
102 CHECK_CAPMODE(stat, "/tmp/cap_capmode_stat", &sb);
103 CHECK_CAPMODE(symlink,
104 "/tmp/cap_capmode_symlink_from",
105 "/tmp/cap_capmode_symlink_to");
106 CHECK_CAPMODE(unlink, "/tmp/cap_capmode_unlink");
107 CHECK_CAPMODE(unmount, "/not_mounted", 0);
108
109 /*
110 * System calls that are permitted in capability mode.
111 */
112 CHECK_SYSCALL_SUCCEEDS(close, fd_close);
113 CHECK_SYSCALL_SUCCEEDS(dup, fd_file);
114 CHECK_SYSCALL_SUCCEEDS(fstat, fd_file, &sb);
115 CHECK_SYSCALL_SUCCEEDS(lseek, fd_file, 0, SEEK_SET);
116 CHECK_SYSCALL_SUCCEEDS(msync, &fd_file, 8192, MS_ASYNC);
117 CHECK_SYSCALL_SUCCEEDS(profil, NULL, 0, 0, 0);
118 CHECK_SYSCALL_SUCCEEDS(read, fd_file, &ch, sizeof(ch));
119 CHECK_SYSCALL_SUCCEEDS(recvfrom, fd_socket, NULL, 0, 0, NULL, NULL);
120 CHECK_SYSCALL_SUCCEEDS(setuid, getuid());
121 CHECK_SYSCALL_SUCCEEDS(write, fd_file, &ch, sizeof(ch));
122
123 /*
124 * These calls will fail for lack of e.g. a proper name to send to,
125 * but they are allowed in capability mode, so errno != ECAPMODE.
126 */
127 CHECK_NOT_CAPMODE(accept, fd_socket, NULL, NULL);
128 CHECK_NOT_CAPMODE(getpeername, fd_socket, NULL, NULL);
129 CHECK_NOT_CAPMODE(getsockname, fd_socket, NULL, NULL);
130 CHECK_NOT_CAPMODE(fchflags, fd_file, UF_NODUMP);
131 CHECK_NOT_CAPMODE(recvmsg, fd_socket, NULL, 0);
132 CHECK_NOT_CAPMODE(sendmsg, fd_socket, NULL, 0);
133 CHECK_NOT_CAPMODE(sendto, fd_socket, NULL, 0, 0, NULL, 0);
134
135 /*
136 * System calls which should be allowed in capability mode, but which
137 * don't return errors, and are thus difficult to check.
138 *
139 * We will try anyway, by checking errno.
140 */
141 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getegid);
142 CHECK_SYSCALL_VOID_NOT_ECAPMODE(geteuid);
143 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getgid);
144 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getpid);
145 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getppid);
146 CHECK_SYSCALL_VOID_NOT_ECAPMODE(getuid);
147
148 /*
149 * Finally, tests for system calls that don't fit the pattern very well.
150 */
151 pid = fork();
152 if (pid >= 0) {
153 if (pid == 0) {
154 exit(0);
155 } else if (pid > 0) {
156 wpid = waitpid(pid, NULL, 0);
157 if (wpid < 0) {
158 if (errno != ECAPMODE)
159 FAIL("capmode:waitpid");
160 } else
161 FAIL("capmode:waitpid succeeded");
162 }
163 } else
164 FAIL("capmode:fork");
165
166 if (getlogin() == NULL)
167 FAIL("test_sycalls:getlogin %d", errno);
168
169 if (getsockname(fd_socket, NULL, NULL) < 0) {
170 if (errno == ECAPMODE)
171 FAIL("capmode:getsockname");
172 }
173
174 /* XXXRW: ktrace */
175
176 if (pipe(fd2) == 0) {
177 close(fd2[0]);
178 close(fd2[1]);
179 } else if (errno == ECAPMODE)
180 FAIL("capmode:pipe");
181
182 /* XXXRW: ptrace. */
183
184 /* sysarch() is, by definition, architecture-dependent */
185 #if defined (__amd64__) || defined (__i386__)
186 CHECK_CAPMODE(sysarch, I386_SET_IOPERM, &sysarch_arg);
187 #else
188 /* XXXJA: write a test for arm */
189 FAIL("capmode:no sysarch() test for current architecture");
190 #endif
191
192 /* XXXRW: No error return from sync(2) to test. */
193
194 return (success);
195 }
196