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/* This example code is placed in the public domain. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>
/* udp.c */
int udp_connect(void);
void udp_close(int sd);
/* Connects to the peer and returns a socket
* descriptor.
*/
extern int udp_connect(void)
{
const char *PORT = "5557";
const char *SERVER = "127.0.0.1";
int err, sd;
#if defined(IP_DONTFRAG) || defined(IP_MTU_DISCOVER)
int optval;
#endif
struct sockaddr_in sa;
/* connects to server
*/
sd = socket(AF_INET, SOCK_DGRAM, 0);
memset(&sa, '\0', sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_port = htons(atoi(PORT));
inet_pton(AF_INET, SERVER, &sa.sin_addr);
#if defined(IP_DONTFRAG)
optval = 1;
setsockopt(sd, IPPROTO_IP, IP_DONTFRAG, (const void *)&optval,
sizeof(optval));
#elif defined(IP_MTU_DISCOVER)
optval = IP_PMTUDISC_DO;
setsockopt(sd, IPPROTO_IP, IP_MTU_DISCOVER, (const void *)&optval,
sizeof(optval));
#endif
err = connect(sd, (struct sockaddr *)&sa, sizeof(sa));
if (err < 0) {
fprintf(stderr, "Connect error\n");
exit(1);
}
return sd;
}
/* closes the given socket descriptor.
*/
extern void udp_close(int sd)
{
close(sd);
}
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