Implement queue system to display peers broadcasting

net.c

@@ -1,6 +1,8 @@
 #include "net.h"
 #include "log.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
 
 typedef struct {
 	struct sockaddr_in addr;
@@ -8,6 +10,18 @@ typedef struct {
 	socklen_t addr_len;
 } net_info;
 
+typedef struct peer_addr_node {
+	struct sockaddr_in addr;
+	time_t time_last;
+	time_t time_elapsed;
+	struct peer_addr_node* next;
+} peer_addr_node;
+static peer_addr_node* peer_list = NULL;
+
+static int peer_list_add(struct sockaddr_in* addr);
+static int peer_list_exists(struct sockaddr_in* addr);
+static void peer_list_destroy();
+
 static net_info broadcast_info;
 static net_info listen_info;
 static net_info peer_info;
@@ -18,7 +32,7 @@ static int init = 0;
 int net_init(unsigned int port)
 {
 	PORT = port;
-	// broadcast socket init
+	// broadcast socket
 	broadcast_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
 	if (broadcast_info.socket < 0) {
 		log_message(LOG_ERROR, "Error creating broadcast socket");
@@ -36,7 +50,7 @@ int net_init(unsigned int port)
 
 	broadcast_info.addr_len = sizeof(broadcast_info.addr);
 
-	// listen socket init
+	// listen socket
 	listen_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
 	if (listen_info.socket < 0) {
 		log_message(LOG_ERROR, "Error creating listen socket", strerror(errno));
@@ -71,6 +85,14 @@ int net_init(unsigned int port)
 	return 1;
 }
 
+void net_destroy()
+{
+	close(broadcast_info.socket);
+	close(listen_info.socket);
+	close(peer_info.socket);
+	peer_list_destroy();
+}
+
 int net_broadcast()
 {
 	if (!init) return 0;;
@@ -88,59 +110,92 @@ int net_broadcast()
 	return 1;
 }
 
-int net_listen_clients()
+int net_listen_peers()
 {
 	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;
-	}
+	net_info broadcast_listen;
 
-	peer_info.socket = socket(AF_INET, SOCK_DGRAM, 0);
-	if (peer_info.socket < 0) {
+	broadcast_listen.socket = socket(AF_INET, SOCK_DGRAM, 0);
+	if (broadcast_listen.socket < 0) {
 		log_message(LOG_ERROR, "Error creating listen socket", strerror(errno));
-		close(peer_info.socket);
+		close(broadcast_listen.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);
+	memset(&broadcast_listen.addr, 0, sizeof(broadcast_listen.addr));
+	broadcast_listen.addr.sin_family = AF_INET;
+	broadcast_listen.addr.sin_addr.s_addr = INADDR_ANY;
+	broadcast_listen.addr.sin_port = htons(PORT);
 
-	peer_info.addr_len = sizeof(peer_info.addr);
+	broadcast_listen.addr_len = sizeof(broadcast_listen.addr);
 
 	int retv = recvfrom(listen_info.socket, buffer, sizeof(buffer), 0,
-	                    (struct sockaddr*)&peer_info.addr,
-	                    &peer_info.addr_len);
+	                    (struct sockaddr*)&broadcast_listen.addr,
+	                    &broadcast_listen.addr_len);
+
+	close(broadcast_listen.socket);
 
 	if (retv < 0) {
-		log_message(LOG_ERROR, "Failed to receive broadcast message: %s", strerror(errno));
-		close(peer_info.socket);
-		peer_info.socket = -1;
+		if (errno != EAGAIN)
+			log_message(LOG_ERROR, "Failed to receive broadcast message: %s", strerror(errno));
+		close(broadcast_listen.socket);
+		broadcast_listen.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);
+	            "Broadcast message received from:\n%s:%d\n%s",
+	            inet_ntoa(broadcast_listen.addr.sin_addr),
+	            ntohs(broadcast_listen.addr.sin_port),
+	            buffer);
+
+	retv = peer_list_exists(&broadcast_listen.addr);
+	if (retv) return 0;
+
+	peer_list_add(&broadcast_listen.addr);
 
 	return 1;
 }
 
-int net_send()
+int net_prune_peers()
 {
 	if (!init) return 0;
+	if (!peer_list) return 0;
+	int pruned = 0;
+	peer_addr_node* node = peer_list;
+	peer_addr_node* last_node = NULL;
+	while (node) {
+		peer_addr_node* next_node = node->next;
+
+		node->time_elapsed += time(NULL) - node->time_last;
+		node->time_last = time(NULL);
+
+		if (node->time_elapsed < CLIENT_MAX_TIME) {
+			last_node = node;
+			goto next;
+		}
+
+		pruned = 1;
+		free(node);
+		if (node == peer_list)
+			peer_list = next_node;
+		if (last_node != NULL)
+			last_node->next = next_node;
+next:
+		node = next_node;
+	}
+	return pruned;
+}
+
+int net_send(void* buffer, size_t size)
+{
+	if (!init) return 0;
+	if (peer_info.socket < 0) return 0;
 	return 1;
 }
 
@@ -149,3 +204,74 @@ int net_receive()
 	if (!init) return 0;
 	return 1;
 }
+
+void net_print_peers()
+{
+	if (!peer_list) return;
+	peer_addr_node* node = peer_list;
+	while (node) {
+		log_message(LOG_INFO,
+		            "Peers :\n%s:%d",
+		            inet_ntoa(node->addr.sin_addr),
+		            ntohs(node->addr.sin_port));
+		node = node->next;
+	}
+}
+
+int net_get_peers(struct sockaddr_in** peer_addr)
+{
+	if (!peer_list) return 0;
+	static peer_addr_node* node = NULL;
+	static int done = 0;
+
+	if (done) {
+		done = 0;
+		return 0;
+	}
+
+	if (!node) node = peer_list;
+	*peer_addr = &node->addr;
+
+	if (!node->next) done = 1;
+	node = node->next;
+	return 1;
+}
+
+static int peer_list_add(struct sockaddr_in* addr)
+{
+	peer_addr_node* new_node = malloc(sizeof(peer_addr_node));
+	size_t size = sizeof(struct sockaddr_in);
+	memset(&new_node->addr, 0, sizeof(size));
+	memcpy(&new_node->addr, addr, sizeof(size));
+	new_node->time_last = time(NULL);
+	new_node->time_elapsed = 0;
+	new_node->next = peer_list ? peer_list : NULL;
+	peer_list = new_node;
+	return 1;
+}
+
+static int peer_list_exists(struct sockaddr_in* addr)
+{
+	if (!peer_list) return 0;
+	peer_addr_node* node = peer_list;
+	while (node) {
+		int address_match = addr->sin_addr.s_addr == node->addr.sin_addr.s_addr;
+		int port_match = addr->sin_port == node->addr.sin_port;
+		if (address_match && port_match) {
+			node->time_elapsed = 0;
+			return 1;
+		}
+		node = node->next;
+	}
+	return 0;
+}
+
+static void peer_list_destroy()
+{
+	peer_addr_node* node = peer_list;
+	while (node) {
+		peer_addr_node* next_node = node->next;
+		free(node);
+		node = next_node;
+	}
+}