xref: /freebsd/tools/regression/netinet/tcpdrop/tcpdrop.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*-
2  * Copyright (c) 2006 Robert N. M. Watson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * TCP regression test for the tcpdrop sysctl; build a loopback TCP
31  * connection, drop it, and make sure both endpoints return that the
32  * connection has been reset.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <sys/sysctl.h>
38 
39 #include <netinet/in.h>
40 
41 #include <err.h>
42 #include <errno.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #define	TCP_PORT	9001
50 
51 static int
52 tcp_drop(struct sockaddr_in *sin_local, struct sockaddr_in *sin_remote)
53 {
54 	struct sockaddr_storage addrs[2];
55 
56 	/*
57 	 * Sysctl accepts an array of two sockaddr's, the first being the
58 	 * 'foreign' sockaddr, the second being the 'local' sockaddr.
59 	 */
60 
61 	bcopy(sin_remote, &addrs[0], sizeof(*sin_remote));
62 	bcopy(sin_local, &addrs[1], sizeof(*sin_local));
63 
64 	return (sysctlbyname("net.inet.tcp.drop", NULL, 0, addrs,
65 	    sizeof(addrs)));
66 }
67 
68 static void
69 tcp_server(pid_t partner)
70 {
71 	int error, listen_fd, accept_fd;
72 	struct sockaddr_in sin;
73 	ssize_t len;
74 	char ch;
75 
76 	listen_fd = socket(PF_INET, SOCK_STREAM, 0);
77 	if (listen_fd < 0) {
78 		error = errno;
79 		(void)kill(partner, SIGTERM);
80 		errno = error;
81 		err(-1, "tcp_server: socket");
82 	}
83 
84 	bzero(&sin, sizeof(sin));
85 	sin.sin_family = AF_INET;
86 	sin.sin_len = sizeof(sin);
87 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
88 	sin.sin_port = htons(TCP_PORT);
89 
90 	if (bind(listen_fd, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
91 		error = errno;
92 		(void)kill(partner, SIGTERM);
93 		errno = error;
94 		err(-1, "tcp_server: bind");
95 	}
96 
97 	if (listen(listen_fd, -1) < 0) {
98 		error = errno;
99 		(void)kill(partner, SIGTERM);
100 		errno = error;
101 		err(-1, "tcp_server: listen");
102 	}
103 
104 	accept_fd = accept(listen_fd, NULL, NULL);
105 	if (accept_fd < 0) {
106 		error = errno;
107 		(void)kill(partner, SIGTERM);
108 		errno = error;
109 		err(-1, "tcp_server: accept");
110 	}
111 
112 	/*
113 	 * Send one byte, make sure that worked, wait for the drop, and try
114 	 * sending another.  By sending small amounts, we avoid blocking
115 	 * waiting on the remote buffer to be drained.
116 	 */
117 	ch = 'A';
118 	len = send(accept_fd, &ch, sizeof(ch), MSG_NOSIGNAL);
119 	if (len < 0) {
120 		error = errno;
121 		(void)kill(partner, SIGTERM);
122 		errno = error;
123 		err(-1, "tcp_server: send (1)");
124 	}
125 	if (len != sizeof(ch)) {
126 		(void)kill(partner, SIGTERM);
127 		errx(-1, "tcp_server: send (1) len");
128 	}
129 
130 	sleep (10);
131 
132 	ch = 'A';
133 	len = send(accept_fd, &ch, sizeof(ch), MSG_NOSIGNAL);
134 	if (len >= 0) {
135 		(void)kill(partner, SIGTERM);
136 		errx(-1, "tcp_server: send (2): success");
137 	} else if (errno != EPIPE) {
138 		error = errno;
139 		(void)kill(partner, SIGTERM);
140 		errno = error;
141 		err(-1, "tcp_server: send (2)");
142 	}
143 
144 	close(accept_fd);
145 	close(listen_fd);
146 }
147 
148 static void
149 tcp_client(pid_t partner)
150 {
151 	struct sockaddr_in sin, sin_local;
152 	int error, sock;
153 	socklen_t slen;
154 	ssize_t len;
155 	char ch;
156 
157 	sleep(1);
158 
159 	sock = socket(PF_INET, SOCK_STREAM, 0);
160 	if (sock < 0) {
161 		error = errno;
162 		(void)kill(partner, SIGTERM);
163 		errno = error;
164 		err(-1, "socket");
165 	}
166 
167 	bzero(&sin, sizeof(sin));
168 	sin.sin_family = AF_INET;
169 	sin.sin_len = sizeof(sin);
170 	sin.sin_addr.s_addr = ntohl(INADDR_LOOPBACK);
171 	sin.sin_port = htons(TCP_PORT);
172 
173 	if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
174 		error = errno;
175 		(void)kill(partner, SIGTERM);
176 		errno = error;
177 		err(-1, "connect");
178 	}
179 
180 	slen = sizeof(sin_local);
181 	if (getsockname(sock, (struct sockaddr *)&sin_local, &slen) < 0) {
182 		error = errno;
183 		(void)kill(partner, SIGTERM);
184 		errno = error;
185 		err(-1, "getsockname");
186 	}
187 
188 	/*
189 	 * Send one byte, make sure that worked, wait for the drop, and try
190 	 * sending another.  By sending small amounts, we avoid blocking
191 	 * waiting on the remote buffer to be drained.
192 	 */
193 	ch = 'A';
194 	len = send(sock, &ch, sizeof(ch), MSG_NOSIGNAL);
195 	if (len < 0) {
196 		error = errno;
197 		(void)kill(partner, SIGTERM);
198 		errno = error;
199 		err(-1, "tcp_client: send (1)");
200 	}
201 	if (len != sizeof(ch)) {
202 		(void)kill(partner, SIGTERM);
203 		errx(-1, "tcp_client: send (1) len");
204 	}
205 
206 	sleep(5);
207 	if (tcp_drop(&sin_local, &sin) < 0) {
208 		error = errno;
209 		(void)kill(partner, SIGTERM);
210 		errno = error;
211 		err(-1, "tcp_client: tcp_drop");
212 	}
213 	sleep(5);
214 
215 	ch = 'A';
216 	len = send(sock, &ch, sizeof(ch), MSG_NOSIGNAL);
217 	if (len >= 0) {
218 		(void)kill(partner, SIGTERM);
219 		errx(-1, "tcp_client: send (2): success");
220 	} else if (errno != EPIPE) {
221 		error = errno;
222 		(void)kill(partner, SIGTERM);
223 		errno = error;
224 		err(-1, "tcp_client: send (2)");
225 	}
226 	close(sock);
227 }
228 
229 int
230 main(int argc, char *argv[])
231 {
232 	pid_t child_pid, parent_pid;
233 
234 	if (signal(SIGCHLD, SIG_IGN) == SIG_ERR)
235 		err(-1, "signal");
236 
237 	parent_pid = getpid();
238 	child_pid = fork();
239 	if (child_pid < 0)
240 		err(-1, "fork");
241 	if (child_pid == 0) {
242 		child_pid = getpid();
243 		tcp_server(parent_pid);
244 	} else
245 		tcp_client(child_pid);
246 
247 	return (0);
248 }
249