1 /*-
2  * Copyright (c) 2004 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 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <sys/time.h>
32 
33 #include <netinet/in.h>
34 
35 #include <arpa/inet.h>
36 
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 static void
42 usage(void)
43 {
44 
45 	fprintf(stderr, "netreceive [port]\n");
46 	exit(-1);
47 }
48 
49 int
50 main(int argc, char *argv[])
51 {
52 	struct sockaddr_in sin;
53 	char *dummy, *packet;
54 	long port;
55 	int s, v;
56 
57 	if (argc != 2)
58 		usage();
59 
60 	bzero(&sin, sizeof(sin));
61 	sin.sin_len = sizeof(sin);
62 	sin.sin_family = AF_INET;
63 	sin.sin_addr.s_addr = htonl(INADDR_ANY);
64 
65 	port = strtoul(argv[1], &dummy, 10);
66 	if (port < 1 || port > 65535 || *dummy != '\0')
67 		usage();
68 	sin.sin_port = htons(port);
69 
70 	packet = malloc(65536);
71 	if (packet == NULL) {
72 		perror("malloc");
73 		return (-1);
74 	}
75 	bzero(packet, 65536);
76 
77 	s = socket(PF_INET, SOCK_DGRAM, 0);
78 	if (s == -1) {
79 		perror("socket");
80 		return (-1);
81 	}
82 
83 	v = 128 * 1024;
84 	if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &v, sizeof(v)) < 0) {
85 		perror("SO_RCVBUF");
86 		return (-1);
87 	}
88 
89 	if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
90 		perror("bind");
91 		return (-1);
92 	}
93 
94 	printf("netreceive listening on UDP port %d\n", (u_short)port);
95 
96 	while (1) {
97 		if (recv(s, packet, 65536, 0) < 0)
98 			perror("recv");
99 	}
100 }
101