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1 /*
2  * Check decoding of netlink protocol.
3  *
4  * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org>
5  * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "tests.h"
32 
33 #ifdef HAVE_SYS_XATTR_H
34 
35 # include <stdio.h>
36 # include <stdlib.h>
37 # include <string.h>
38 # include <unistd.h>
39 # include <sys/xattr.h>
40 # include <netinet/in.h>
41 # include <linux/netlink.h>
42 # include <linux/sock_diag.h>
43 # include <linux/netlink_diag.h>
44 
45 # if !defined NETLINK_SOCK_DIAG && defined NETLINK_INET_DIAG
46 #  define NETLINK_SOCK_DIAG NETLINK_INET_DIAG
47 # endif
48 
49 static void
send_query(const int fd)50 send_query(const int fd)
51 {
52 	static const struct req {
53 		struct nlmsghdr nlh;
54 		const char magic[4];
55 	} c_req = {
56 		.nlh = {
57 			.nlmsg_len = sizeof(struct req),
58 			.nlmsg_type = NLMSG_NOOP,
59 			.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST
60 		},
61 		.magic = "abcd"
62 	};
63 	struct req *const req = tail_memdup(&c_req, sizeof(c_req));
64 	long rc;
65 	const char *errstr;
66 
67 	/* zero address */
68 	rc = sendto(fd, NULL, sizeof(*req), MSG_DONTWAIT, NULL, 0);
69 	printf("sendto(%d, NULL, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
70 	       fd, (unsigned) sizeof(*req), sprintrc(rc));
71 
72 	/* zero length */
73 	rc = sendto(fd, req, 0, MSG_DONTWAIT, NULL, 0);
74 	printf("sendto(%d, \"\", 0, MSG_DONTWAIT, NULL, 0) = %s\n",
75 	       fd, sprintrc(rc));
76 
77 	/* zero address and length */
78 	rc = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
79 	printf("sendto(%d, NULL, 0, MSG_DONTWAIT, NULL, 0) = %s\n",
80 	       fd, sprintrc(rc));
81 
82 	/* unfetchable struct nlmsghdr */
83 	const void *const efault = tail_alloc(sizeof(struct nlmsghdr) - 1);
84 	rc = sendto(fd, efault, sizeof(struct nlmsghdr), MSG_DONTWAIT, NULL, 0);
85 	printf("sendto(%d, %p, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
86 	       fd, efault, (unsigned) sizeof(struct nlmsghdr), sprintrc(rc));
87 
88 	/* whole message length < sizeof(struct nlmsghdr) */
89 	rc = sendto(fd, req->magic, sizeof(req->magic), MSG_DONTWAIT, NULL, 0);
90 	printf("sendto(%d, \"abcd\", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
91 	       fd, (unsigned) sizeof(req->magic), sprintrc(rc));
92 
93 	/* a single message with some data */
94 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
95 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
96 	       ", seq=0, pid=0}, \"abcd\"}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
97 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
98 	       (unsigned) sizeof(*req), sprintrc(rc));
99 
100 	/* a single message without data */
101 	req->nlh.nlmsg_len = sizeof(req->nlh);
102 	rc = sendto(fd, &req->nlh, sizeof(req->nlh), MSG_DONTWAIT, NULL, 0);
103 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
104 	       ", seq=0, pid=0}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
105 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
106 	       (unsigned) sizeof(req->nlh), sprintrc(rc));
107 
108 	/* nlmsg_len > whole message length */
109 	req->nlh.nlmsg_len = sizeof(*req) + 8;
110 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
111 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
112 	       ", seq=0, pid=0}, \"abcd\"}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
113 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
114 	       (unsigned) sizeof(*req), sprintrc(rc));
115 
116 	/* nlmsg_len < sizeof(struct nlmsghdr) */
117 	req->nlh.nlmsg_len = 8;
118 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
119 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
120 	       ", seq=0, pid=0}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
121 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
122 	       (unsigned) sizeof(*req), sprintrc(rc));
123 
124 	/* a sequence of two nlmsg objects */
125 	struct reqs {
126 		struct req req1;
127 		char padding[NLMSG_ALIGN(sizeof(struct req)) - sizeof(struct req)];
128 		struct req req2;
129 	} *const reqs = tail_alloc(sizeof(*reqs));
130 	memcpy(&reqs->req1, &c_req, sizeof(c_req));
131 	memcpy(&reqs->req2, &c_req, sizeof(c_req));
132 
133 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
134 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
135 	       ", seq=0, pid=0}, \"abcd\"}, {{len=%u, type=NLMSG_NOOP"
136 	       ", flags=NLM_F_REQUEST|0x%x, seq=0, pid=0}, \"abcd\"}]"
137 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
138 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
139 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
140 	       (unsigned) sizeof(*reqs), sprintrc(rc));
141 
142 	/* unfetchable second struct nlmsghdr */
143 	void *const efault2 = tail_memdup(&reqs->req1, sizeof(reqs->req1));
144 	rc = sendto(fd, efault2, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
145 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
146 	       ", seq=0, pid=0}, \"abcd\"}, %p], %u, MSG_DONTWAIT, NULL, 0)"
147 	       " = %s\n",
148 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
149 	       &((struct reqs *) efault2)->req2, (unsigned) sizeof(*reqs),
150 	       sprintrc(rc));
151 
152 	/* message length is not enough for the second struct nlmsghdr */
153 	rc = sendto(fd, reqs, sizeof(*reqs) - sizeof(req->nlh), MSG_DONTWAIT,
154 		    NULL, 0);
155 	errstr = sprintrc(rc);
156 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
157 	       ", seq=0, pid=0}, \"abcd\"}, \"",
158 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP);
159 	print_quoted_memory((void *) &reqs->req2.nlh,
160 			    sizeof(reqs->req2) - sizeof(req->nlh));
161 	printf("\"], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
162 	       (unsigned) (sizeof(*reqs) - sizeof(req->nlh)), errstr);
163 
164 	/* second nlmsg_len < sizeof(struct nlmsghdr) */
165 	reqs->req2.nlh.nlmsg_len = 4;
166 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
167 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
168 	       ", seq=0, pid=0}, \"abcd\"}, {{len=%u, type=NLMSG_NOOP"
169 	       ", flags=NLM_F_REQUEST|0x%x, seq=0, pid=0}}], %u"
170 	       ", MSG_DONTWAIT, NULL, 0) = %s\n",
171 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
172 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
173 	       (unsigned) sizeof(*reqs), sprintrc(rc));
174 
175 	/* abbreviated output */
176 # define DEFAULT_STRLEN 32
177 # define ABBREV_LEN (DEFAULT_STRLEN + 1)
178 	const unsigned int msg_len = sizeof(struct nlmsghdr) * ABBREV_LEN;
179 	struct nlmsghdr *const msgs = tail_alloc(msg_len);
180 	unsigned int i;
181 	for (i = 0; i < ABBREV_LEN; ++i) {
182 		msgs[i].nlmsg_len = sizeof(*msgs);
183 		msgs[i].nlmsg_type = NLMSG_NOOP;
184 		msgs[i].nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
185 		msgs[i].nlmsg_seq = i;
186 		msgs[i].nlmsg_pid = 0;
187 	}
188 
189 	rc = sendto(fd, msgs, msg_len, MSG_DONTWAIT, NULL, 0);
190 	errstr = sprintrc(rc);
191 	printf("sendto(%d, [", fd);
192 	for (i = 0; i < DEFAULT_STRLEN; ++i) {
193 		if (i)
194 			printf(", ");
195 		printf("{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
196 		       ", seq=%u, pid=0}}",
197 		       msgs[i].nlmsg_len, NLM_F_DUMP, msgs[i].nlmsg_seq);
198 	}
199 	printf(", ...], %u, MSG_DONTWAIT, NULL, 0) = %s\n", msg_len, errstr);
200 }
201 
main(void)202 int main(void)
203 {
204 	struct sockaddr_nl addr;
205 	socklen_t len = sizeof(addr);
206 	int fd;
207 
208 	memset(&addr, 0, sizeof(addr));
209 	addr.nl_family = AF_NETLINK;
210 
211 	if ((fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG)) == -1)
212 		perror_msg_and_skip("socket AF_NETLINK");
213 
214 	printf("socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG) = %d\n",
215 	       fd);
216 	if (bind(fd, (struct sockaddr *) &addr, len))
217 		perror_msg_and_skip("bind");
218 	printf("bind(%d, {sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}"
219 	       ", %u) = 0\n", fd, len);
220 
221 	char *path;
222 	if (asprintf(&path, "/proc/self/fd/%u", fd) < 0)
223 		perror_msg_and_fail("asprintf");
224 	char buf[256];
225 	if (getxattr(path, "system.sockprotoname", buf, sizeof(buf) - 1) < 0)
226 		perror_msg_and_skip("getxattr");
227 	free(path);
228 
229 	send_query(fd);
230 
231 	printf("+++ exited with 0 +++\n");
232 
233 	return 0;
234 }
235 
236 #else
237 
238 SKIP_MAIN_UNDEFINED("HAVE_SYS_XATTR_H")
239 
240 #endif
241