/*
    Simple udp server
*/
#include<stdio.h> //printf
#include<string.h> //memset
#include<stdlib.h> //exit(0);
#include<arpa/inet.h>
#include<sys/socket.h>
 
#define BUFLEN 512  //Max length of buffer
#define PORT 8888   //The port on which to listen for incoming data
 
void die(char *s)
{
    perror(s);
    exit(1);
}
 
int main(void)
{
    struct sockaddr_in si_me, si_other;
     
    int s, i, slen = sizeof(si_other) , recv_len;
   // char buf[BUFLEN];
     
    //create a UDP socket
    if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    {
        die("socket");
    }
     
    // zero out the structure
    memset((char *) &si_me, 0, sizeof(si_me));
     
    si_me.sin_family = AF_INET;
    si_me.sin_port = htons(PORT);
    si_me.sin_addr.s_addr = htonl(INADDR_ANY);
     
    //bind socket to port
    if( bind(s , (struct sockaddr*)&si_me, sizeof(si_me) ) == -1)
    {
        die("bind");
    }
     
    //keep listening for data
    while(1)
    {
		char buf[BUFLEN];
        printf("Waiting for data...");
        fflush(stdout);
        memset(buf,'\0', BUFLEN);
        //try to receive some data, this is a blocking call
        if ((recv_len = recvfrom(s, buf, BUFLEN, 0, (struct sockaddr *) &si_other, &slen)) == -1)
        {
            die("recvfrom()");
        }
         
        //print details of the client/peer and the data received
        printf("Received packet from %s:%d\n", inet_ntoa(si_other.sin_addr), ntohs(si_other.sin_port));
        printf("Data: %s\n" , buf);
         /*
        //now reply the client with the same data
        if (sendto(s, buf, recv_len, 0, (struct sockaddr*) &si_other, slen) == -1)
        {
            die("sendto()");
        }*/
    }
 
    close(s);
    return 0;
}





/* CLIENT ############################################################################################################*/





/*
    Simple udp client
*/
#include<stdio.h> //printf
#include<string.h> //memset
#include<stdlib.h> //exit(0);
#include<arpa/inet.h>
#include<sys/socket.h>
 
#define SERVER "127.0.0.1"
#define BUFLEN 512  //Max length of buffer
#define PORT 8888   //The port on which to send data
 
void die(char *s)
{
    perror(s);
    exit(1);
}
 
int main(void)
{
    struct sockaddr_in si_other;
    int s, i, slen=sizeof(si_other);
    char buf[BUFLEN];
    char text[BUFLEN];
    char *message;
    int ppc;
 
    if ( (s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    {
        die("socket");
    }
 
    memset((char *) &si_other, 0, sizeof(si_other));
    si_other.sin_family = AF_INET;
    si_other.sin_port = htons(PORT);
     
    if (inet_aton(SERVER , &si_other.sin_addr) == 0) 
    {
        fprintf(stderr, "inet_aton() failed\n");
        exit(1);
    }
    while(1)
    {	
		/*
		memset(buf,'\0', BUFLEN);
        
        if (recvfrom(s, buf, BUFLEN, 0, (struct sockaddr *) &si_other, &slen) != -1)
        {
          //  die("recvfrom()");
          puts(buf);
          
        }	
        */
        printf("Enter message : ");
        gets(text);
        i = strlen(text) + 1;
		message = (char*)malloc(i * sizeof(char));
        strcpy(message, text);
        //send the message
        if (sendto(s, message, strlen(message) , 0 , (struct sockaddr *) &si_other, slen)==-1)
        {
            die("sendto()");
        }
    }
 
    close(s);
    return 0;
}