comparison udp-test-sink.c @ 9:c00510e1ae8b

new program udp-test-sink
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 10 Mar 2024 02:27:37 +0000
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8:d180987db615 9:c00510e1ae8b
1 /*
2 * This program is a simple sink for UDP: it binds to a UDP port and sinks
3 * (reads and discards) all packets that arrive at it. Upon receiving a
4 * burst or stream of packets followed by a prolonged pause, it prints
5 * the number of packets that were received.
6 */
7
8 #include <sys/types.h>
9 #include <sys/socket.h>
10 #include <sys/time.h>
11 #include <sys/errno.h>
12 #include <netinet/in.h>
13 #include <arpa/inet.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <strings.h>
18 #include <unistd.h>
19
20 static void
21 parse_ip_port(arg, sin)
22 char *arg;
23 struct sockaddr_in *sin;
24 {
25 char *cp;
26 int rc;
27
28 cp = index(arg, ':');
29 if (!cp) {
30 fprintf(stderr, "error: missing ':' in IP:port argument\n");
31 exit(1);
32 }
33 *cp++ = '\0';
34 sin->sin_family = AF_INET;
35 rc = inet_aton(arg, &sin->sin_addr);
36 if (!rc) {
37 fprintf(stderr, "error: invalid IP address argument\n");
38 exit(1);
39 }
40 sin->sin_port = htons(atoi(cp));
41 }
42
43 main(argc, argv)
44 char **argv;
45 {
46 struct sockaddr_in bindsin;
47 int udp_fd, rc;
48 unsigned idle_sec, rx_count;
49 fd_set fds;
50 struct timeval tv;
51 u_char dummybuf[256];
52
53 if (argc < 2 || argc > 3) {
54 fprintf(stderr, "usage: bind-IP:port [idle-sec]\n", argv[0]);
55 exit(1);
56 }
57 parse_ip_port(argv[1], &bindsin);
58 if (argc >= 3)
59 idle_sec = atoi(argv[2]);
60 else
61 idle_sec = 0;
62 udp_fd = socket(AF_INET, SOCK_DGRAM, 0);
63 if (udp_fd < 0) {
64 perror("socket(AF_INET, SOCK_DGRAM, 0)");
65 exit(1);
66 }
67 rc = bind(udp_fd, (struct sockaddr *) &bindsin, sizeof bindsin);
68 if (rc < 0) {
69 perror("bind");
70 exit(1);
71 }
72 for (rx_count = 0; ; ) {
73 FD_ZERO(&fds);
74 FD_SET(udp_fd, &fds);
75 if (rx_count && idle_sec) {
76 tv.tv_sec = idle_sec;
77 tv.tv_usec = 0;
78 rc = select(udp_fd+1, &fds, 0, 0, &tv);
79 } else
80 rc = select(udp_fd+1, &fds, 0, 0, 0);
81 if (rc < 0) {
82 if (errno == EINTR)
83 continue;
84 perror("select");
85 exit(1);
86 }
87 if (FD_ISSET(udp_fd, &fds)) {
88 recv(udp_fd, dummybuf, sizeof dummybuf, 0);
89 rx_count++;
90 } else {
91 printf("Received %u packet%s\n", rx_count,
92 rx_count != 1 ? "s" : "");
93 rx_count = 0;
94 }
95 }
96 }