TCP Client Server Communication

How do you communicate through internet ? what protocol do you use ? How the connection is established ?


Well , today we are going to see about establishing a simple tcp connection between client and the server .

In the client side , we are gonna to establish a connection with server (send a request )

For that we need to do 3 things ,
1.socket() -- create a socket .
2.connect() -- make a connection with the server .
3.recv() -- for receving data from server .  

below picture tells the needs for tcp client .

	#include<stdio.h>
	#include<stdlib.h>
	#include<sys/types.h> // to use many data types
	#include<sys/socket.h> // to create a socket connection
	#include<netinet/in.h> // to address internet protocol
	int main()
	{
	int client_socket ;
	client_socket = socket(AF_INET , SOCK_STREAM , 0);
	// AF_INET - AF_INET is the address family that is used for the socket you're creating (in this case an Internet Protocol address).
	struct sockaddr_in server_address;
	// Creating a socket
	server_address.sin_family = AF_INET;
	server_address.sin_port = htons(9003);
	server_address.sin_addr.s_addr = INADDR_ANY;
	//connecting with socket
	connect(client_socket , (struct sockaddr*) &server_address , sizeof(server_address));
	//reciving data
	char server_response[256];
	//reciving data from server
	recv(client_socket , &server_response , sizeof(server_response) , 0) ;
	printf("[+] Connection Established\n");
	printf("[+] Message from server : %s\n",server_response);
	close(client_socket);
	return 0;
	}

view raw tcp_client.c hosted with ❤ by GitHub

In tcp server , we are going get the response from the client and response to it .
For establishing a tcp server connection we need to do 4 things ,
1: socket() -- create a socket connection .
2: bind() -- bind with ip , server_address , port .
3: listen() -- listen for any connections that are active .
4: accept() -- for accepting the client request .

	#include<stdio.h>
	#include<stdlib.h>
	#include<sys/types.h> // For supporting many data types
	#include<sys/socket.h> // For creation of socket
	#include<netinet/in.h> // For addressing Internet protocol
	int main()
	{
	int server_socket ;
	char server_message[256]="Hi buddy , This is Lazy Swapper" ;
	// creating a SOCKET
	server_socket = socket(AF_INET , SOCK_STREAM , 0);
	struct sockaddr_in server_address;
	server_address.sin_family = AF_INET;
	server_address.sin_port = htons(9003);
	server_address.sin_addr.s_addr = INADDR_ANY ;
	//binding the socket
	bind(server_socket , (struct sockaddr*) &server_address , sizeof(server_address));
	//listening for connection
	listen(server_socket , 5 );
	// 5 denotes no of connection
	//accepting the request
	int client_socket ;
	client_socket = accept(server_socket , NULL , NULL);
	//sending the message
	send(client_socket , server_message , sizeof(server_message) ,0 );
	printf("[+] successfully message has been sent ");
	close(server_socket);
	return 0;
	}

view raw tcp_server.c hosted with ❤ by GitHub

For video reference : tcp client
tcp server