Trying to implement TCP echo server in C - linux

Question

Was trying to implement a TCP echo server with C, and came across this code while searching the web and was trying to compile it. It shows some error related to socket.h
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <error.h>
#include <strings.h>
#include <unistd.h>
#define ERROR -1
#define MAX_CLIENTS 2
#define MAX_DATA 1024
int main(int argc, char **argv)
{
struct sockaddr_in server;
struct sockaddr_in client;
int sock;
int new;
int sockaddr_len = sizeof(struct sockaddr_in);
int data_len;
char data[MAX_DATA];
if((sock = socket(AF_INET, SOCK_STREAM, 0)) == ERROR)
{
perror("server socket: ");
exit(-1);
}
server.sin_family=AF_INET;
server.sin_port=htons(atoi(argv[1]));
server.sin_addr.s_addr=INADDR_ANY;
bzero(&server.sin_zero, 0);
if((bind(sock, (struct sockaddr *)&server, sockaddr_len)) == ERROR)
{
perror("bind: ");
exit(-1);
}
if((listen(sock, MAX_CLIENTS)) == ERROR)
{
perror("listen");
exit(-1);
}
while(1)
{
if((new = accept(sock, (struct sockaddr *)&client, sockaddr_len)) == ERROR)
{
perror("accept");
exit(-1);
}
printf("New Client connected from port no %d and IP %s\n", ntohs(client.sin_port), inet_ntoa(client.sin_addr));
data_len = 1;
while(data_len)
{
data_len = recv(new, data, MAX_DATA, 0);
if(data_len)
{
send(new, data, data_len, 0);
data[data_len] = '\0';
printf("Sent mesg: %s", data);
}
}
printf("Client disconnected\n");
close(new);
}
close(sock);
}
While compiling in Linux using gcc (Debian 8.3.0-6) 8.3.0 following warnings/errors are thrown,
tcp_srv.c: In function ‘main’:
tcp_srv.c:50:54: warning: passing argument 3 of ‘accept’ makes pointer from integer without a cast [-Wint-conversion]
if((new = accept(sock, (struct sockaddr *)&client, sockaddr_len)) == ERROR)
^~~~~~~~~~~~
In file included from tcp_srv.c:4:
/usr/include/x86_64-linux-gnu/sys/socket.h:233:28: note: expected ‘socklen_t * restrict’ {aka ‘unsigned int * restrict’} but argument is of type ‘int’
socklen_t *__restrict __addr_len);
The binary upon execution is giving a Segmentation fault which I assume due to this error. Tried googling this error but couldn't get any solutions as such.

Answer 1

accept prototype is:
int accept(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len);
and manual says:
The address_len is a value-result parameter; it should initially
contain the
amount of space pointed to by address; on return it will contain the actual length
(in bytes) of the address returned.
Third argument must be pointer to a socklen_t thus:
if((new = accept(sock, (struct sockaddr *)&client, &sockaddr_len)) == ERROR)