#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#define PORT 8008
#define RECIEVE_BUFFER_SIZE 1024
int main() {
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if ( sockfd < 0) {
perror("socket creation failed");
exit(EXIT_FAILURE);
}
struct sockaddr_in serverAddress;
memset(&serverAddress, 0, sizeof(serverAddress));
serverAddress.sin_family = AF_INET;
serverAddress.sin_addr.s_addr = INADDR_ANY;
serverAddress.sin_port = htons(PORT);
if(bind(sockfd, (const struct sockaddr*)&serverAddress, sizeof(serverAddress))){
perror("bind failed");
exit(EXIT_FAILURE);
}
struct sockaddr_in clientAddress; unsigned int clientAddressSize = sizeof(clientAddress);
memset(&clientAddress, 0, clientAddressSize);
char buffer[RECIEVE_BUFFER_SIZE];
while(1){
int bytesRecieved = recvfrom(sockfd, (char*)buffer, RECIEVE_BUFFER_SIZE, MSG_WAITALL, (struct sockaddr*) &clientAddress, &clientAddressSize);
buffer[bytesRecieved] = '\0';
if(bytesRecieved >= 4 && (strncmp("PING", buffer, 4) == 0)){
const char* responseMessage = "PONG";
sendto(sockfd, (const char*)responseMessage, strlen(responseMessage), MSG_CONFIRM, (const struct sockaddr*) &clientAddress, clientAddressSize);
}else{
printf("Server bytes recieved: %d\nServer message recieved: %s", bytesRecieved, buffer);
}
}
return 0;
}