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1 /*
2  * Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org>
3  * Copyright (c) 2015-2017 The strace developers.
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  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "tests.h"
30 #include <assert.h>
31 #include <fcntl.h>
32 #include <stdio.h>
33 #include <stdint.h>
34 #include <unistd.h>
35 #include <sys/socket.h>
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
38 
39 static void
print_pktinfo(const struct cmsghdr * c)40 print_pktinfo(const struct cmsghdr *c)
41 {
42 	printf("IP_PKTINFO, cmsg_data={ipi_ifindex=%s"
43 	       ", ipi_spec_dst=inet_addr(\"%s\")"
44 	       ", ipi_addr=inet_addr(\"%s\")}",
45 	       IFINDEX_LO_STR, "127.0.0.1", "127.0.0.1");
46 }
47 
48 static void
print_ttl(const struct cmsghdr * c)49 print_ttl(const struct cmsghdr *c)
50 {
51 	const unsigned int *ttl = (const unsigned int *) CMSG_DATA(c);
52 
53 	printf("IP_TTL, cmsg_data=[%u]", *ttl);
54 }
55 
56 static void
print_tos(const struct cmsghdr * c)57 print_tos(const struct cmsghdr *c)
58 {
59 	const uint8_t *tos = (const uint8_t *) CMSG_DATA(c);
60 
61 	printf("IP_TOS, cmsg_data=[%#x]", *tos);
62 }
63 
64 static void
print_opts(const char * name,const struct cmsghdr * c)65 print_opts(const char *name, const struct cmsghdr *c)
66 {
67 	const unsigned char *opts = (const unsigned char *) CMSG_DATA(c);
68 	const size_t len = c->cmsg_len - CMSG_ALIGN(sizeof(*c));
69 
70 	printf("%s", name);
71 	if (len) {
72 		printf(", cmsg_data=[");
73 		size_t i;
74 		for (i = 0; i < len; ++i)
75 			printf("%s0x%02x", i ? ", " : "", opts[i]);
76 		printf("]");
77 	}
78 }
79 
80 #ifdef IP_ORIGDSTADDR
81 static void
print_origdstaddr(const struct cmsghdr * c)82 print_origdstaddr(const struct cmsghdr *c)
83 {
84 	const struct sockaddr_in *sin =
85 		(const struct sockaddr_in *) CMSG_DATA(c);
86 
87 	printf("IP_ORIGDSTADDR, cmsg_data={sa_family=AF_INET, sin_port=htons(%u)"
88 	       ", sin_addr=inet_addr(\"127.0.0.1\")}", ntohs(sin->sin_port));
89 }
90 #endif
91 
92 int
main(void)93 main(void)
94 {
95 	int i;
96 	while ((i = open("/dev/null", O_RDWR)) < 3)
97 		assert(i >= 0);
98 	assert(!close(0));
99 	assert(!close(3));
100 
101 	if (socket(AF_INET, SOCK_DGRAM, 0))
102 		perror_msg_and_skip("socket");
103 	struct sockaddr_in addr = {
104 		.sin_family = AF_INET,
105 		.sin_addr.s_addr = htonl(INADDR_LOOPBACK)
106 	};
107 	socklen_t len = sizeof(addr);
108 	if (bind(0, (struct sockaddr *) &addr, len))
109 		perror_msg_and_skip("bind");
110 	assert(!getsockname(0, (struct sockaddr *) &addr, &len));
111 
112 	assert(socket(AF_INET, SOCK_DGRAM, 0) == 3);
113 	assert(!connect(3, (struct sockaddr *) &addr, len));
114 
115 	const int opt_1 = htonl(0x01000000);
116 #define SETSOCKOPT(fd, name) assert(!setsockopt(fd, IPPROTO_IP, (name), &opt_1, sizeof(opt_1)))
117 	SETSOCKOPT(3, IP_OPTIONS);
118 	SETSOCKOPT(0, IP_PKTINFO);
119 	SETSOCKOPT(0, IP_RECVTTL);
120 	SETSOCKOPT(0, IP_RECVTOS);
121 	SETSOCKOPT(0, IP_RECVOPTS);
122 	SETSOCKOPT(0, IP_RETOPTS);
123 #ifdef IP_RECVORIGDSTADDR
124 	SETSOCKOPT(0, IP_RECVORIGDSTADDR);
125 #endif
126 
127 	static const char data[] = "data";
128 	const size_t size = sizeof(data) - 1;
129 	assert(send(3, data, size, 0) == (int) size);
130 	assert(!close(3));
131 
132 	char buf[size];
133 	struct iovec iov = {
134 		.iov_base = buf,
135 		.iov_len = sizeof(buf)
136 	};
137 	struct cmsghdr control[16];
138 	struct msghdr mh = {
139 		.msg_name = &addr,
140 		.msg_namelen = len,
141 		.msg_iov = &iov,
142 		.msg_iovlen = 1,
143 		.msg_control = control,
144 		.msg_controllen = sizeof(control)
145 	};
146 
147 	assert(recvmsg(0, &mh, 0) == (int) size);
148 	assert(!close(0));
149 
150 	printf("recvmsg(0, {msg_name={sa_family=AF_INET, sin_port=htons(%u)"
151 	       ", sin_addr=inet_addr(\"127.0.0.1\")}, msg_namelen=%u"
152 	       ", msg_iov=[{iov_base=\"%s\", iov_len=%u}], msg_iovlen=1"
153 	       ", msg_control=[",
154 	       ntohs(addr.sin_port), (unsigned) mh.msg_namelen,
155 	       data, (unsigned) size);
156 
157 	struct cmsghdr *c;
158 	for (c = CMSG_FIRSTHDR(&mh); c; c = CMSG_NXTHDR(&mh, c)) {
159 		if (IPPROTO_IP != c->cmsg_level)
160 			continue;
161 		if (c != control)
162 			printf(", ");
163 		printf("{cmsg_len=%lu, cmsg_level=SOL_IP, cmsg_type=",
164 		       (unsigned long) c->cmsg_len);
165 		switch (c->cmsg_type) {
166 			case IP_PKTINFO:
167 				print_pktinfo(c);
168 				break;
169 			case IP_TTL:
170 				print_ttl(c);
171 				break;
172 			case IP_TOS:
173 				print_tos(c);
174 				break;
175 			case IP_RECVOPTS:
176 				print_opts("IP_RECVOPTS", c);
177 				break;
178 			case IP_RETOPTS:
179 				print_opts("IP_RETOPTS", c);
180 				break;
181 #ifdef IP_ORIGDSTADDR
182 			case IP_ORIGDSTADDR:
183 				print_origdstaddr(c);
184 				break;
185 #endif
186 			default:
187 				printf("%d", c->cmsg_type);
188 				break;
189 		}
190 		printf("}");
191 	}
192 	printf("], msg_controllen=%lu, msg_flags=0}, 0) = %u\n",
193 	       (unsigned long) mh.msg_controllen, (unsigned) size);
194 	puts("+++ exited with 0 +++");
195 
196 	return 0;
197 }
198