1 /*
2 Copyright 2004 Michiel Boland.  All rights reserved.
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 
8 1. Redistributions of source code must retain the above copyright
9 notice, this list of conditions and the following disclaimer.
10 
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 
15 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
20 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
21 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
24 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
25 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 
27 $FreeBSD$
28 
29 */
30 
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <fcntl.h>
35 #include <poll.h>
36 #include <unistd.h>
37 #include <signal.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 /*
42  * The following code sets up two connected TCP sockets that send data to each
43  * other until the window is closed. Then one of the sockets is closed, which
44  * will generate a RST once the TCP at the other socket does a window probe.
45  *
46  * All versions of FreeBSD prior to 11/26/2004 will ignore this RST into a 0
47  * window, causing the connection (and application) to hang indefinitely.
48  * On patched versions of FreeBSD (and other operating systems), the RST
49  * will be accepted and the program will exit in a few seconds.
50  */
51 
52 /*
53  * If the alarm fired then we've hung and the test failed.
54  */
55 void
56 do_alrm(int s)
57 {
58 	printf("not ok 1 - tcpfullwindowrst\n");
59 	exit(0);
60 }
61 
62 int
63 main(void)
64 {
65 	int o, s, t, u, do_t, do_u;
66 	struct pollfd pfd[2];
67 	struct sockaddr_in sa;
68 	char buf[4096];
69 
70 	printf("1..1\n");
71 	signal(SIGALRM, do_alrm);
72 	alarm(20);
73 
74 	s = socket(AF_INET, SOCK_STREAM, 0);
75 	if (s == -1)
76 		return 1;
77 	o = 1;
78 	setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &o, sizeof o);
79 	memset(&sa, 0, sizeof sa);
80 	sa.sin_family = AF_INET;
81 	sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
82 	sa.sin_port = htons(3737);
83 	if (bind(s, (struct sockaddr *) &sa, sizeof sa) == -1)
84 		return 1;
85 	if (listen(s, 1) == -1)
86 		return 1;
87 	t = socket(AF_INET, SOCK_STREAM, 0);
88 	if (t == -1)
89 		return 1;
90 	if (connect(t, (struct sockaddr *) &sa, sizeof sa) == -1)
91 		return 1;
92 	u = accept(s, 0, 0);
93 	if (u == -1)
94 		return 1;
95 	close(s);
96 	fcntl(t, F_SETFL, fcntl(t, F_GETFL) | O_NONBLOCK);
97 	fcntl(u, F_SETFL, fcntl(t, F_GETFL) | O_NONBLOCK);
98 	do_t = 1;
99 	do_u = 1;
100 	pfd[0].fd = t;
101 	pfd[0].events = POLLOUT;
102 	pfd[1].fd = u;
103 	pfd[1].events = POLLOUT;
104 	while (do_t || do_u) {
105 		if (poll(pfd, 2, 1000) == 0) {
106 			if (do_t) {
107 				close(t);
108 				pfd[0].fd = -1;
109 				do_t = 0;
110 			}
111 			continue;
112 		}
113 		if (pfd[0].revents & POLLOUT) {
114 			if (write(t, buf, sizeof buf) == -1) {
115 				close(t);
116 				pfd[0].fd = -1;
117 				do_t = 0;
118 			}
119 		}
120 		if (pfd[1].revents & POLLOUT) {
121 			if (write(u, buf, sizeof buf) == -1) {
122 				close(u);
123 				pfd[1].fd = -1;
124 				do_u = 0;
125 			}
126 		}
127 	}
128 
129 	printf("ok 1 - tcpfullwindowrst\n");
130 	return 0;
131 }
132