CRC Server code in C

#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_gen_fn.c"

#define RESET(buff) for(i=0;i<100;i++) buff[i]='\0';

void error(const char *msg)

{

perror(msg);

exit(1);

}

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

{

int sockfd,newsockfd,i;

struct sockaddr_in serv_addr,cli_addr;

char buff[100],key[100],data[100];

char *res=malloc(30);

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 Socket");

//Binding

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

error("Error in binding");

//Listen

listen(sockfd,5);

while(1)

{

clilen = sizeof(cli_addr);

newsockfd = accept(sockfd , (struct sockaddr *)&cli_addr, &clilen);

if(newsockfd < 0)

error("Error in Accept");

RESET(buff)

strcpy(buff," Enter the data : ");

send(newsockfd , buff, 100, 0);

RESET(data)

recv(newsockfd , data, 100, 0);

RESET(buff);

strcpy(buff,"Enter the key : ");

send(newsockfd, buff, 100, 0);

RESET(buff);

recv(newsockfd, buff, 100, 0);

printf("\n From Client : %s \n",data);

res = crc(data , buff);

strcpy(buff,res);

send(newsockfd , buff, 100 , 0);

RESET(buff)

recv(newsockfd , buff, 100, 0);

printf("\n Message from Client : %s \n",buff);

close(newsockfd);

}

return 0;

}