1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include "clientserver.h"
void error(const char *msg)
{
perror(msg);
exit(EXIT_FAILURE);
}
int main(int argc, char **argv)
{
struct sockaddr_in si_server;
int port, s, i, slen = sizeof(si_server);
char buf[BUFLEN];
char *srv_addr;
fd_set readfds;
struct timeval tv;
int ret;
if (argc < 3) {
printf("Usage: %s ip_add port\n", argv[0]);
exit(1);
}
port = atoi(argv[2]);
srv_addr = argv[1];
if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
error("socket");
}
memset((char *) &si_server, 0, sizeof(si_server));
si_server.sin_family = AF_INET;
si_server.sin_port = htons(port);
if (inet_aton(srv_addr, &si_server.sin_addr) == 0) {
fprintf(stderr, "inet_aton() failed\n");
exit(EXIT_FAILURE);
}
for (i = 0; i < NPACK; i++) {
sprintf(buf, "DATA PACKET # %d", i);
printf("Sending -- %s -- to %s:%d\n", buf,
inet_ntoa(si_server.sin_addr), ntohs(si_server.sin_port));
slen = sizeof(si_server);
if (sendto(s, buf, BUFLEN, 0, (struct sockaddr *) &si_server, slen)
== -1) {
error("sendto()");
}
FD_ZERO(&readfds);
FD_SET(s, &readfds);
tv.tv_sec = 1;
tv.tv_usec = 0;
if (select(s + 1, &readfds, NULL, NULL, &tv) == -1) {
error("select()");
}
if (FD_ISSET(s, &readfds)) {
ret =
recvfrom(s, buf, BUFLEN, 0, (struct sockaddr *) &si_server,
&slen);
if (ret > 0) {
printf("Received -- %s -- from %s:%d\n", buf,
inet_ntoa(si_server.sin_addr),
ntohs(si_server.sin_port));
}
}
sleep(2);
}
close(s);
return 0;
}
|
