UDP Data Xchange
Was working on a UDP dataXcahnge project ,thought this code fragment will be of some use to newbees.
Server Code :
#include <netinet/in.h>
#include <sys/socket.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include <arpa/inet.h>
#include <sys/types.h>
#define BUFLEN 512
#define PORT 10000
void die_err(char *s)
{
perror(s);
exit(1);
}
int main(void)
{
struct sockaddr_in *sock_server, *sock_client;
int s;
socklen_t socklen=sizeof(struct sockaddr_in);
char buf[BUFLEN];
sock_server = malloc( socklen );
sock_client = malloc( socklen );
if ( !sock_server || !sock_client )
die_err( "allocation failed" );
if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1)
die_err("socket");
sock_server->sin_family = AF_INET;
sock_server->sin_port = htons(PORT);
sock_server->sin_addr.s_addr = htonl(INADDR_ANY);
if ( bind(s, (struct sockaddr *)sock_server, socklen )==-1)
die_err("bind");
while( 1 ) {
if (recvfrom(s, buf, BUFLEN, 0,
(struct sockaddr *)sock_client, &socklen)==-1)
die_err("recvfrom()");
printf("Received packet from %s:%d\nData: %s\n",
inet_ntoa(sock_client->sin_addr),
ntohs(sock_client->sin_port), buf);
}
close(s);
return 0;
}
Client Code :
#include <netinet/in.h>
#include <sys/socket.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <sys/types.h>
#define BUFLEN 512
#define PORT 10000
#define USERVER "127.0.0.1"
void die_err(char *s)
{
perror(s);
exit(1);
}
int main(void)
{
struct sockaddr_in *sock_server;
int s, i;
socklen_t socklen=sizeof(struct sockaddr_in);
char buf[BUFLEN];
sock_server = malloc( socklen );
if ( !sock_server )
die_err( "allocation failed" );
if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1)
die_err("socket");
sock_server->sin_family = AF_INET;
sock_server->sin_port = htons(PORT);
if (inet_aton(USERVER, &(sock_server->sin_addr))==0) {
fprintf(stderr, "inet_aton() failed\n");
exit(1);
}
for (i=0; i<3; i++) {
printf("Sending packet %d\n", i);
sprintf(buf, "This is packet %d\n", i);
if (sendto(s, buf, BUFLEN, 0,
(struct sockaddr*)sock_server, socklen)==-1)
die_err("sendto()");
}
close(s);
return 0;
}
