Network

About

It is simple internet interface for easier working with networking in c/c++. The library is written in c. Useful and lightweight. Core idea was assignment at university with networking. All functions operate in non-blocking mode. Includes a simple chat example with a server, allowing many users to chat with each other.

_{Built with C · CMake · Docker · GitHub Actions · Cross-Platform}

TOC

• About
• TOC
• Screenshots
• Supported Platforms
• Installation
• Usage
• Code Snippets
• Full Example
• Features
• License
• Prerequisites

Screenshots

Supported Platforms

Platform	support
Linux	✅ Yes
Windows	✅ Yes
macOS	❌ No
Android	❌ No
iOS	❌ No

Installation

As Library

1. clone repository

 git clone https://github.com/Daynlight/Network.git

2. add subdirectory

add_subdirectory(Network)

3. add to your project

target_link_libraries(AppNetwork)

Chat App

1. clone repository

 git clone https://github.com/Daynlight/Network.git

2. compile via cmake

# you need to change address in Example/Chat/Macro.h# in default it uses my google cloud server so many # users can access it
mkdir build
cd build/
cmake ..

3. run server

 ./../bin/Server

4. run client

 ./../bin/Client

Usage

Info and Recommend Usage

• Server and Client works on non-blocking sockets. You need loop for receiving data.

• For Video/Music etc. data are send as char buffer and on client side are used in proper way.

• Best way to use it is making some custom format. for example make first byte 255 or more are always operations register,login etc. then you check this first byte and make operation based on this.

• Good practice is to optimize buffer before sending it, SIGINT handling. Also good idea is compression and encryptionCCrypt.

• After client connect it sets his socket to non-blocking

SIGINT handling

voidsigint_handler(intsig){
network_client_destroy(&network);
printf("Network destroyed!\n");
running=0;
exit(EXIT_FAILURE);
};

Server

Functions

• network_server_init - initialize server
• network_server_destroy - destroy server
• network_server_listen - tcp listen for users connections
• network_server_read - tcp read data from client
• network_server_send - tcp send data to client
• network_get_client_ip - get ip from socket
• network_server_read_from - udp read data from client
• network_server_send_to - tcp send data to client

Client

Functions

• network_client_init - initialize client
• network_client_destroy - destroy client
• network_client_connect - tcp connect client to server
• network_client_read - tcp read data from server
• network_client_send - tcp send data to server
• network_client_read_from - udp read data from server
• network_client_send_to - udp send data to server
• network_client_send_request - udp combination of send and read

Server/Client

• network_check_if_empty_message - check if message is not empty

NetworkModes

• TCP - tcp protocol
• UDP - udp protocol

TCP Mode

• In tcp mode client and server creates connection via listen and connect
• listen returns user socket you should implement your own client manager
• Data are exchanged via send and read functions for client and server
• You need specify maximal message size
• If message is to long then send up to max size

UDP Mode

• In udp mode client and server don't create connection so you don't use listen and connect
• You also don't need to create client manager
• Data are exchanged via send_to and read_from
• For client You can run request that is combination of send_to and read_from
• For server when read_from You add reference to client and then when send_to use it
• You need specify maximal message size
• If message is to long then send up to max size

Network Provider

• sock - socket id
• serv_addr - sockaddr_in for server
• mode - contains TCP/UDP mode used in socket

NetworkCodes

• NODATA - send or read no data
• DISCONNECT - server or client is disconnecting
• NOCLIENT - no client to connect
• DNSERROR - can't find domain
• SOCKETERROR - can't create socket
• CONNECTERROR can't connect to server
• ERRORCODE - error when function called
• SUCCESS - function end up with success

Code Snippets

Server

network_server_init

switch (network_server_init(&network, UDP, PORT)){
caseERRORCODE:
printf("Can't Initialize Server\n");
network_server_destroy(&network);
exit(EXIT_FAILURE);
break;
default: printf("Server Initialized\n");
printf("Server is running\n");
break;
};

network_server_destroy

network_server_destroy(&network);

network_server_listen

intsocket=network_server_listen(network); 

network_server_read

charbuffer[BUFFER_SIZE+NAMESIZE] = {0};
intvalread=network_server_read(&clients.clientData[i].socket_id, buffer, BUFFER_SIZE+NAMESIZE);

network_server_send

charmessage[NAMESIZE+BUFFER_SIZE] ="message";
network_server_send(&(clients->clientData[j].socket_id), message, BUFFER_SIZE+NAMESIZE);

network_get_client_ip

charip[INET_ADDRSTRLEN];
network_get_client_ip(&socket, ip);

network_server_read_from

structsockaddrclient_socket= {0};
charrequest[BUFFER_SIZE] = {0};
intval=network_server_read_from(&network, &client_socket, request, BUFFER_SIZE);

network_server_send_to

charrespond[BUFFER_SIZE] ="respond";
network_server_send_to(&network, &client_socket, respond, BUFFER_SIZE);

Client

network_client_init

switch (network_client_init(&network, UDP, ADDR, PORT)){
caseCONNECTERROR:
printf("Can't init network\n");
exit(EXIT_FAILURE);
break;
caseDNSERROR:
printf("Can't find ip from dns!\n");
exit(EXIT_FAILURE);
break;
default: printf("Client initalized!\n");
break;
};

network_client_destroy

network_client_destroy(&network);

network_client_connect

switch (network_client_connect(&network)){
caseCONNECTERROR:
printf("Can't connect to network!\n");
network_client_destroy(&network);
printf("Network destroyed!\n");
exit(EXIT_FAILURE);
break;
default:
printf("Connected to server!\n"); break;
};

network_client_read

charrespond[BUFFER_SIZE+NAMESIZE] = {0};
network_client_read(&network, respond, BUFFER_SIZE+NAMESIZE)

network_client_send

charsend_request[NAMESIZE+BUFFER_SIZE] ="request";
network_client_send(network, send_request, NAMESIZE+BUFFER_SIZE);

network_client_read_from

charrespond[NAMESIZE+BUFFER_SIZE] = {0};
intval=network_client_read_from(network_provider, respond, NAMESIZE+BUFFER_SIZE);
for(unsigned inti=0; i<100; i++) {
if(val==NODATA) {
sleep(1/20);
val=network_client_read_from(network_provider, respond, NAMESIZE+BUFFER_SIZE);
};
};
printf("%s\n", respond);

network_client_send_to

charrequest[NAMESIZE+BUFFER_SIZE] ="request";
network_client_send_to(network_provider, request, NAMESIZE+BUFFER_SIZE)

network_client_send_request

charrespond[BUFFER_SIZE] = {0};
network_client_send_request(&network, request, BUFFER_SIZE, respond, 20, 100);
printf("%s\n", respond);

Server/Client

network_check_if_empty_message

if(network_check_if_empty_message(request) ==NODATA){
printf("Can't send empty message\n");
};

Small Example

• TCP Example
• UDP Example

Full Example

• Chat Example

Features

• Non-blocking I/O: No need to wait for data to be read or sent; the program can continue executing while awaiting network events.
• Multiple Client Handling: The server can handle multiple client connections simultaneously.
• Protocols: TCP and UDP protocol
• Cross-Platform: Windows and Linux supported.
• Working Example: Ran server in cloud. So many users can connect and chat with each other.

License

GNU GENERAL PUBLIC LICENSE Version 2, June 1991

Prerequisites

• CMake 3.15 or higher
• Git (for cloning with submodules)