server.c

/*
 * Title : Remote command execution using UDP
 * Name : Aditya Pratap Singh Rajput
 * Subject : Network Protocols And Programming using C
 * 
Note : please consider the TYPOS in comments.
Thanks.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <string.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <unistd.h>
#define MAX 1000
int main()
{

    int serverDescriptor = socket(AF_INET, SOCK_DGRAM, 0);
    int size;
    char buffer[MAX], message[] = "Command Successfully executed !";
    struct sockaddr_in clientAddress, serverAddress;

    socklen_t clientLength = sizeof(clientAddress);

    bzero(&serverAddress, sizeof(serverAddress));
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
    serverAddress.sin_port = htons(9976);

    bind(serverDescriptor, (struct sockaddr *)&serverAddress, sizeof(serverAddress));
    while (1)
    {
        bzero(buffer, sizeof(buffer));
        recvfrom(serverDescriptor, buffer, sizeof(buffer), 0, (struct sockaddr *)&clientAddress, &clientLength);
        system(buffer);
        printf("Command Executed ... %s ", buffer);
        sendto(serverDescriptor, message, sizeof(message), 0, (struct sockaddr *)&clientAddress, clientLength);
    }
    close(serverDescriptor);
    return 0;
}