sdl-audio/net.c

#include "net.h"
#include "log.h"
#include <stdio.h>

typedef struct {
	struct sockaddr_in addr;
	int socket;
	socklen_t addr_len;
} net_info;

static net_info broadcast_info;
static net_info listen_info;
static net_info peer_info;
static int PORT;

static int init = 0;

int net_init(unsigned int port)
{
	PORT = port;
	// broadcast socket init
	broadcast_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
	if (broadcast_info.socket < 0) {
		log_message(LOG_ERROR, "Error creating broadcast socket");
		close(broadcast_info.socket);
		return 0;
	}

	int broadcast_enable = 1;
	if (setsockopt(broadcast_info.socket, SOL_SOCKET, SO_BROADCAST, &broadcast_enable, sizeof(broadcast_enable)) < 0) return 0;

	memset(&broadcast_info.addr, 0, sizeof(broadcast_info.addr));
	broadcast_info.addr.sin_family = AF_INET;
	broadcast_info.addr.sin_addr.s_addr = inet_addr("255.255.255.255");
	broadcast_info.addr.sin_port = htons(port);

	broadcast_info.addr_len = sizeof(broadcast_info.addr);

	// listen socket init
	listen_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
	if (listen_info.socket < 0) {
		log_message(LOG_ERROR, "Error creating listen socket", strerror(errno));
		close(listen_info.socket);
		return 0;
	}

	int reuse_enable = 1;
	if (setsockopt(listen_info.socket, SOL_SOCKET, SO_REUSEADDR, &reuse_enable, sizeof(reuse_enable)) < 0) return 0;

	memset(&listen_info.addr, 0, sizeof(listen_info.addr));
	listen_info.addr.sin_family = AF_INET;
	listen_info.addr.sin_addr.s_addr = INADDR_BROADCAST;
	listen_info.addr.sin_port = htons(port);

	listen_info.addr_len =sizeof(listen_info.addr);

	struct timeval tv;
	tv.tv_sec = 0;
	tv.tv_usec = 100000;
	setsockopt(listen_info.socket, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));

	if (bind(listen_info.socket, (const struct sockaddr*)&listen_info.addr, sizeof(listen_info.addr)) < 0) {
		log_message(LOG_ERROR, "Socket bind failed: %s", strerror(errno));
		close(listen_info.socket);
		return 0;
	}

	peer_info.socket = -1;

	init = 1;
	return 1;
}

int net_broadcast()
{
	if (!init) return 0;;
	const char* message = "broadcast message";
	int retv = sendto(broadcast_info.socket, message,
	                  strlen(message), 0,
	                  (struct sockaddr*)&broadcast_info.addr,
	                  broadcast_info.addr_len);
	if (retv < 0) {
		log_message(LOG_ERROR, "Failed to send broadcast message: %s", strerror(errno));
		log_message(LOG_ERROR, "retv: %i", retv);
		return 0;
	}
	log_message(LOG_INFO, "Broadcast message sent");
	return 1;
}

int net_listen_clients()
{
	if (!init) return 0;

	if (peer_info.socket >= 0) {
		log_message(LOG_WARNING, "Peer socket already created");
		log_message(LOG_INFO,
		            "Peer socket address:\n%s:%d",
		            inet_ntoa(peer_info.addr.sin_addr),
		            ntohs(peer_info.addr.sin_port));
		return 1;
	}

	peer_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
	if (peer_info.socket < 0) {
		log_message(LOG_ERROR, "Error creating listen socket", strerror(errno));
		close(peer_info.socket);
		return 0;
	}

	char buffer[64];

	memset(&peer_info.addr, 0, sizeof(peer_info.addr));
	peer_info.addr.sin_family = AF_INET;
	peer_info.addr.sin_addr.s_addr = INADDR_ANY;
	peer_info.addr.sin_port = htons(PORT);

	peer_info.addr_len = sizeof(peer_info.addr);

	int retv = recvfrom(listen_info.socket, buffer, sizeof(buffer), 0,
	                    (struct sockaddr*)&peer_info.addr,
	                    &peer_info.addr_len);

	if (retv < 0) {
		log_message(LOG_ERROR, "Failed to receive broadcast message: %s", strerror(errno));
		close(peer_info.socket);
		peer_info.socket = -1;
		return 0;
	}

	buffer[retv] = '\0';
	log_message(LOG_INFO,
	            "Broadcast message received from:\n%s:%d",
	            inet_ntoa(peer_info.addr.sin_addr),
	            ntohs(peer_info.addr.sin_port));
	log_message(LOG_INFO, "%s", buffer);

	return 1;
}

int net_send()
{
	if (!init) return 0;
	return 1;
}

int net_receive()
{
	if (!init) return 0;
	return 1;
}