CRC Implementation with Socket - Server

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <unistd.h>

#include <arpa/inet.h>

#include "crc_generator.c"

#define MAX_BUFF 80

#define MAX_KEY 20

#define SA struct sockaddr

#define RESET(buff) \

for (int i = 0; i < MAX_BUFF; i++) \

buff[i] = '\0';

void error(const char *msg)

{

perror(msg);

exit(1);

}

void readIndefinitely(int connfd)

{

char buffer[MAX_BUFF], key[MAX_KEY], RESPONSE_OK[] = "200", RESPONSE_ERROR[] = "300";

int n;

// Indefinite loop for chat

// Clear the buffer

RESET(buffer)

RESET(key)

// Request input data

read(connfd, buffer, sizeof(buffer));

printf("Buffer : %s \n", buffer);

write(connfd, "data recieved", sizeof(buffer));

read(connfd, key, sizeof(key));

printf("Key : %s \n", key);

write(connfd, "key received", sizeof(buffer));

if(verifycrc(buffer, key)<0){

write(connfd, "Checksum Failed", sizeof(buffer));

}else{

write(connfd, "Checksum Success", sizeof(buffer));

}

}

int main(int argc, char const *argv[])

{

int MAX_CLIENT = 5;

int sockfd, newsockfd, i;

struct sockaddr_in serv_addr, cli_addr;

int clilen;

// Checking the provided port no

if (argc < 2)

error("Port No not provided");

serv_addr.sin_family = AF_INET;

serv_addr.sin_addr.s_addr = INADDR_ANY;

serv_addr.sin_port = htons(atoi(argv[1]));

// Socket

if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)

error("Error in Creating Socket");

else

printf("Socket created successfully ...\n");

// Binding

if (bind(sockfd, (SA *)&serv_addr, sizeof(serv_addr)) < 0)

error("Error in binding");

else

printf("Binding to Port : %s \n", argv[1]);

// Listen

if (listen(sockfd, MAX_CLIENT) != 0)

{

error("Error in Listening ...");

}

else

printf("Started listening MAX client : %d\n", MAX_CLIENT);

while (1)

{

// Accept

clilen = sizeof(cli_addr);

newsockfd = accept(sockfd, (SA *)&cli_addr, (socklen_t *)&clilen);

if (newsockfd < 0)

error("Error in Accept");

else

printf("\nAccepted the client : %d\n", newsockfd);

// Start Chatting

readIndefinitely(newsockfd);

}

close(newsockfd);

return 0;

}