xref: /freebsd/tests/sys/capsicum/bindat_connectat.c (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
1 /*
2  * Copyright (c) 2017 Jan Kokemüller
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/capsicum.h>
31 #include <sys/socket.h>
32 #include <sys/sysctl.h>
33 #include <sys/stat.h>
34 
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
37 
38 #include <atf-c.h>
39 #include <dlfcn.h>
40 #include <errno.h>
41 #include <stdarg.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "freebsd_test_suite/macros.h"
46 
47 static int rootfd = -1;
48 
49 /* circumvent bug 215690 */
50 int
51 open(const char *path, int flags, ...)
52 {
53 	mode_t mode = 0;
54 
55 	if (flags & O_CREAT) {
56 		va_list ap;
57 		va_start(ap, flags);
58 		mode = (mode_t) va_arg(ap, int);
59 		va_end(ap);
60 	}
61 
62 	if (path && path[0] == '/' && rootfd >= 0) {
63 		return (openat(rootfd, path + 1, flags, mode));
64 	} else {
65 		return (openat(AT_FDCWD, path, flags, mode));
66 	}
67 }
68 
69 static void
70 check_capsicum(void)
71 {
72 	ATF_REQUIRE_FEATURE("security_capabilities");
73 	ATF_REQUIRE_FEATURE("security_capability_mode");
74 
75 	ATF_REQUIRE((rootfd = open("/", O_EXEC | O_CLOEXEC)) >= 0);
76 }
77 
78 typedef int (*socket_fun)(int, const struct sockaddr *, socklen_t);
79 
80 static int
81 connectat_fdcwd(int s, const struct sockaddr *name, socklen_t namelen)
82 {
83 
84 	return (connectat(AT_FDCWD, s, name, namelen));
85 }
86 
87 static int
88 bindat_fdcwd(int s, const struct sockaddr *name, socklen_t namelen)
89 {
90 
91 	return (bindat(AT_FDCWD, s, name, namelen));
92 }
93 
94 
95 ATF_TC(bindat_connectat_1);
96 ATF_TC_HEAD(bindat_connectat_1, tc)
97 {
98 	atf_tc_set_md_var(tc, "descr",
99 	    "Verify that connect/bind work in normal case");
100 }
101 
102 static void
103 check_1(socket_fun f, int s, const struct sockaddr_in *name)
104 {
105 
106 	ATF_REQUIRE((s = socket(AF_INET, SOCK_STREAM, 0)) >= 0);
107 	ATF_REQUIRE_ERRNO(EAFNOSUPPORT,
108 	    f(s, (const struct sockaddr *)(name),
109 	        sizeof(struct sockaddr_in)) < 0);
110 }
111 
112 ATF_TC_BODY(bindat_connectat_1, tc)
113 {
114 	struct sockaddr_in sin;
115 
116 	memset(&sin, 0, sizeof(sin));
117 	sin.sin_family = AF_INET;
118 	sin.sin_port = htons(0);
119 	sin.sin_addr.s_addr = htonl(0xE0000000);
120 
121 	check_1(bindat_fdcwd, 0, &sin);
122 	check_1(bind, 0, &sin);
123 	check_1(connectat_fdcwd, 0, &sin);
124 	check_1(connect, 0, &sin);
125 }
126 
127 
128 ATF_TC(bindat_connectat_2);
129 ATF_TC_HEAD(bindat_connectat_2, tc)
130 {
131 	atf_tc_set_md_var(tc, "descr",
132 	    "Verify that connect/bind are disabled in cap-mode");
133 }
134 
135 static void
136 check_2(socket_fun f, int s, const struct sockaddr_in *name)
137 {
138 
139 	ATF_REQUIRE_ERRNO(ECAPMODE,
140 	    f(s, (const struct sockaddr *)name,
141 	        sizeof(struct sockaddr_in)) < 0);
142 }
143 
144 ATF_TC_BODY(bindat_connectat_2, tc)
145 {
146 	int sock;
147 	struct sockaddr_in sin;
148 
149 	check_capsicum();
150 
151 	ATF_REQUIRE(cap_enter() >= 0);
152 
153 	/* note: sock is created _after_ cap_enter() and contains all rights */
154 	ATF_REQUIRE((sock = socket(AF_INET, SOCK_STREAM, 0)) >= 0);
155 
156 	memset(&sin, 0, sizeof(sin));
157 	sin.sin_family = AF_INET;
158 	/* dummy port and multicast address (224.0.0.0) to distinguish two
159 	 * cases:
160 	 *  - ECAPMODE/ENOTCAPABLE --> call blocked by capsicum
161 	 *  - EAFNOSUPPORT --> call went through to protocol layer
162 	 */
163 	sin.sin_port = htons(0);
164 	sin.sin_addr.s_addr = htonl(0xE0000000);
165 
166 	check_2(bindat_fdcwd, sock, &sin);
167 	check_2(bind, sock, &sin);
168 	check_2(connectat_fdcwd, sock, &sin);
169 	check_2(connect, sock, &sin);
170 }
171 
172 
173 ATF_TC(bindat_connectat_3);
174 ATF_TC_HEAD(bindat_connectat_3, tc)
175 {
176 	atf_tc_set_md_var(tc, "descr",
177 	    "Check that taking away CAP_BIND/CAP_CONNECT "
178 	    "sabotages bind/connect");
179 }
180 
181 static void
182 check_3(socket_fun f, int s, const struct sockaddr_in *name,
183     cap_rights_t *rights, cap_rights_t *sub_rights)
184 {
185 
186 	ATF_REQUIRE((s = socket(AF_INET, SOCK_STREAM, 0)) >= 0);
187 	ATF_REQUIRE(cap_rights_limit(s, rights) >= 0);
188 	ATF_REQUIRE_ERRNO(EAFNOSUPPORT,
189 	    f(s, (const struct sockaddr *)name,
190 	        sizeof(struct sockaddr_in)) < 0);
191 	ATF_REQUIRE(cap_rights_limit(s,
192 	                cap_rights_remove(rights, sub_rights)) >= 0);
193 	ATF_REQUIRE_ERRNO(ENOTCAPABLE,
194 	    f(s, (const struct sockaddr *)name,
195 	        sizeof(struct sockaddr_in)) < 0);
196 }
197 
198 ATF_TC_BODY(bindat_connectat_3, tc)
199 {
200 	struct sockaddr_in sin;
201 	cap_rights_t rights, sub_rights;
202 
203 	check_capsicum();
204 
205 	memset(&sin, 0, sizeof(sin));
206 	sin.sin_family = AF_INET;
207 	sin.sin_port = htons(0);
208 	sin.sin_addr.s_addr = htonl(0xE0000000);
209 
210 	check_3(bindat_fdcwd, 0, &sin,
211 	    cap_rights_init(&rights, CAP_SOCK_SERVER),
212 	    cap_rights_init(&sub_rights, CAP_BIND));
213 	check_3(bind, 0, &sin,
214 	    cap_rights_init(&rights, CAP_SOCK_SERVER),
215 	    cap_rights_init(&sub_rights, CAP_BIND));
216 	check_3(connectat_fdcwd, 0, &sin,
217 	    cap_rights_init(&rights, CAP_SOCK_CLIENT),
218 	    cap_rights_init(&sub_rights, CAP_CONNECT));
219 	check_3(connect, 0, &sin,
220 	    cap_rights_init(&rights, CAP_SOCK_CLIENT),
221 	    cap_rights_init(&sub_rights, CAP_CONNECT));
222 }
223 
224 
225 ATF_TP_ADD_TCS(tp)
226 {
227 
228 	ATF_TP_ADD_TC(tp, bindat_connectat_1);
229 	ATF_TP_ADD_TC(tp, bindat_connectat_2);
230 	ATF_TP_ADD_TC(tp, bindat_connectat_3);
231 
232 	return (atf_no_error());
233 }
234