SChat/server.cpp

#include "server.h"

void *get_client_addr(struct sockaddr *sa) {
    if (sa->sa_family == AF_INET) {
        return &(((struct sockaddr_in *) sa)->sin_addr);
    }

    return &(((struct sockaddr_in6 *) sa)->sin6_addr);
}

int Server::exec() {
	if (!createSocket()) {
		return -1;
	}

    std::cout << "Server: server created and listening on port " << port << std::endl;

    while (true) {
    	std::cout << "Server: awaiting connection...\n";
        ClientData *data = new ClientData(); // would be deleted in thread after its finishing
        data->sockd = accept(sock, (struct sockaddr *) &data->client_sockaddr, &data->client_sockaddr_size);
        std::cout << "Server: got new connection, creating worker thread." << std::endl;
        clients_threads.emplace_back(std::thread(&Server::handleRequest, this, data));
        std::cout << "Server: created worker thread " << clients_threads.back().get_id();
    }
}

bool Server::createSocket() {
	std::cout << "Server: creating socket..." << std::endl;
    sock = socket(AF_INET, SOCK_STREAM, 0);

    int on = 1;
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &on, sizeof(on));

    /* initialize the server's sockaddr */
    struct sockaddr_in server_sockaddr;
    memset(&server_sockaddr, 0, sizeof(server_sockaddr));
    server_sockaddr.sin_family = AF_INET;
    server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_sockaddr.sin_port = htons(port);

    printf("Server: Binding socket %d to sockaddr %p with size %d\n", sock, (struct sockaddr *) &server_sockaddr, sizeof(server_sockaddr));
    int bind_result = bind(sock, (struct sockaddr *) &server_sockaddr, sizeof(server_sockaddr));
    if (bind_result < 0) {
        std::cout << "Server: Error: socket bind failed!" << std::endl;
        return false;
    }    

    listen(sock, max_connections);

    if (sock < 0) {
    	std::cout << "Server: Error, cannot create socket" << std::endl;
    	return false;
    }
    return true;
}

void Server::handleRequest(ClientData* client_data) {
    char ip[17];
    inet_ntop(AF_INET, get_client_addr((struct sockaddr *)&client_data->client_sockaddr), ip, sizeof(ip));

    printf("Worker %u: Established connection with %s beginning work.\n", std::this_thread::get_id(), ip);

    const int request_buffer_size = 65536;
    char request[request_buffer_size];

	// Receiving client type: reader or writer
    int bytes_recvd = recv(client_data->sockd, request, request_buffer_size - 1, 0);

    if (bytes_recvd < 0) {
        fprintf(stderr, "Worker %u: error recv: %s\n", std::this_thread::get_id(), strerror(errno));
        delete client_data;
        return;
    }
    request[bytes_recvd] = '\0';

    if (strcmp(request, "reader") == 0) {
	    printf("Worker %u: Client %s is READER.\n", std::this_thread::get_id(), ip);
	    client_readers_lock.lock();
	    clients_readers.push_back(*client_data);
	    client_readers_lock.unlock();
    } else if (strcmp(request, "writer") == 0) {
	    printf("Worker %u: Client %s is WRITER.\n", std::this_thread::get_id(), ip);
	    while (true) {
	    	    int bytes_recvd = recv(client_data->sockd, request, request_buffer_size - 1, 0);

			    if (bytes_recvd <= 0) {
			        fprintf(stderr, "Worker %u: error recv: %s\n", std::this_thread::get_id(), strerror(errno));
			        delete client_data;
			        return;
			    }
			    request[bytes_recvd] = '\0';

			    printf("Worker %u: received message: %s\n", std::this_thread::get_id(), request);
	    	    client_readers_lock.lock();
	    		for (int i = 0; i < clients_readers.size(); ++i) {
				    send(clients_readers[i].sockd, request, bytes_recvd, 0);
	    		}
	    		client_readers_lock.unlock();
	    }	
    } else {
	    printf("Worker %u: Client %s is UNRECOGNIZED. Error!\n", std::this_thread::get_id(), ip);
    }
}