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 which opens a loopback TCP session, and closes it
31  * before the remote endpoint (server) can accept it.  Run the test twice,
32  * once using an explicit close() from the client, a second using a tcp drop.
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	9005
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 
69 static void
70 tcp_server(pid_t partner)
71 {
72 	int error, listen_fd, accept_fd;
73 	struct sockaddr_in sin;
74 
75 	listen_fd = socket(PF_INET, SOCK_STREAM, 0);
76 	if (listen_fd < 0) {
77 		error = errno;
78 		(void)kill(partner, SIGKILL);
79 		errno = error;
80 		err(-1, "tcp_server: socket");
81 	}
82 
83 	bzero(&sin, sizeof(sin));
84 	sin.sin_family = AF_INET;
85 	sin.sin_len = sizeof(sin);
86 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
87 	sin.sin_port = htons(TCP_PORT);
88 
89 	if (bind(listen_fd, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
90 		error = errno;
91 		(void)kill(partner, SIGKILL);
92 		errno = error;
93 		err(-1, "tcp_server: bind");
94 	}
95 
96 	if (listen(listen_fd, -1) < 0) {
97 		error = errno;
98 		(void)kill(partner, SIGKILL);
99 		errno = error;
100 		err(-1, "tcp_server: listen");
101 	}
102 
103 	sleep(10);
104 
105 	accept_fd = accept(listen_fd, NULL, NULL);
106 	if (accept_fd < 0) {
107 		error = errno;
108 		(void)kill(partner, SIGKILL);
109 		errno = error;
110 		err(-1, "tcp_server: accept");
111 	}
112 	close(accept_fd);
113 	close(listen_fd);
114 }
115 
116 static void
117 tcp_client(pid_t partner, int dropflag)
118 {
119 	struct sockaddr_in sin, sin_local;
120 	int error, sock;
121 	socklen_t slen;
122 
123 	sleep(1);
124 
125 	sock = socket(PF_INET, SOCK_STREAM, 0);
126 	if (sock < 0) {
127 		error = errno;
128 		(void)kill(partner, SIGKILL);
129 		errno = error;
130 		err(-1, "socket");
131 	}
132 
133 	bzero(&sin, sizeof(sin));
134 	sin.sin_family = AF_INET;
135 	sin.sin_len = sizeof(sin);
136 	sin.sin_addr.s_addr = ntohl(INADDR_LOOPBACK);
137 	sin.sin_port = htons(TCP_PORT);
138 
139 	if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
140 		error = errno;
141 		(void)kill(partner, SIGKILL);
142 		errno = error;
143 		err(-1, "connect");
144 	}
145 
146 	slen = sizeof(sin_local);
147 	if (getsockname(sock, (struct sockaddr *)&sin_local, &slen) < 0) {
148 		error = errno;
149 		(void)kill(partner, SIGKILL);
150 		errno = error;
151 		err(-1, "getsockname");
152 	}
153 
154 	if (dropflag) {
155 		if (tcp_drop(&sin_local, &sin) < 0) {
156 			error = errno;
157 			(void)kill(partner, SIGKILL);
158 			errno = error;
159 			err(-1, "tcp_drop");
160 		}
161 		sleep(2);
162 	}
163 	close(sock);
164 }
165 
166 int
167 main(int argc, char *argv[])
168 {
169 	pid_t child_pid, parent_pid;
170 
171 	if (signal(SIGCHLD, SIG_IGN) == SIG_ERR)
172 		err(-1, "signal");
173 
174 	parent_pid = getpid();
175 	child_pid = fork();
176 	if (child_pid < 0)
177 		err(-1, "fork");
178 	if (child_pid == 0) {
179 		child_pid = getpid();
180 		tcp_server(parent_pid);
181 		return (0);
182 	} else
183 		tcp_client(child_pid, 0);
184 	(void)kill(child_pid, SIGTERM);
185 
186 	sleep(5);
187 
188 	parent_pid = getpid();
189 	child_pid = fork();
190 	if (child_pid < 0)
191 		err(-1, "fork");
192 	if (child_pid == 0) {
193 		child_pid = getpid();
194 		tcp_server(parent_pid);
195 		return (0);
196 	} else
197 		tcp_client(child_pid, 1);
198 	(void)kill(child_pid, SIGTERM);
199 
200 	return (0);
201 }
202