ask for peers

src/node.c

@@ -12,7 +12,6 @@
 #include <fcntl.h>
 #include <poll.h>
 #include <unistd.h>
-
 #include "node.h"
 
 // Static variables
@@ -21,6 +20,39 @@ static list *neighbour_list;
 
 /* ----  Fonctions utilitaires  ---- */
 
+// Looks for more peers
+int ask_for_peers(int socket_num) {
+    // Only ask for more peers if the neighbour list is small enough
+    if(len_list(neighbour_list) >= 5)
+        return 0;
+
+    // Get random peer
+    neighbour_peer *peer = get_random_neighbour();
+    struct in6_addr ip = peer->ip;
+    int16_t port = peer->port;
+
+    int ifindex = if_nametoindex("eth0");
+
+    if(ifindex == 0) {
+        perror("if_nametoindex failed");
+        return -1;
+    }
+
+    // Initialize sockaddr
+    struct sockaddr_in6 dest;
+    memset(&dest, 0, sizeof(struct sockaddr_in6));
+    dest.sin6_family = AF_INET6;
+    memcpy(&dest.sin6_addr, &ip, 16);
+    dest.sin6_port = htons(port);
+    dest.sin6_scope_id = ifindex;
+
+    // Send neighbour request TLV
+    tlv neighbour_req;
+    build_neighbour_req(&neighbour_req);
+    
+    return send_single_tlv(&neighbour_req, &dest, socket_num);
+}
+
 // Get list length
 int len_list(list *l) {
 	int len = 0;
@@ -834,19 +866,19 @@ int listen_for_packets(char * received_data_buffer, int received_data_len, struc
 
 }
 
-int t_ask_for_more_peers(list * neighbourhood, int sock_fd){
+int t_ask_for_more_peers(int sock_fd){
+	return ask_for_peers(sock_fd);
+}
+
+int t_get_network_state(int sock_fd){
 	return 0;
 }
 
-int t_get_network_state(list * neighbourhood, int sock_fd){
-	return 0;
-}
-
-int t_update_neighbours(list * neighbourhood){
+int t_update_neighbours(){
 	return update_neighbours();
 }
 
-int run_node(int sock_fd, list * neighbourhood){
+int run_node(int sock_fd){
 	printf(">> Running node...\n");
 
 	int ret;
@@ -872,11 +904,11 @@ int run_node(int sock_fd, list * neighbourhood){
 
 		if(time(NULL) >= delay) {
 			printf(">> Asking for more peers...\n");
-			t_ask_for_more_peers(neighbourhood, sock_fd);
+			t_ask_for_more_peers(sock_fd);
 			printf(">> Updating neighbours...\n");
-			t_update_neighbours(neighbourhood);
+			t_update_neighbours();
 			printf(">> Getting network state...\n");
-			t_get_network_state(neighbourhood, sock_fd);
+			t_get_network_state(sock_fd);
 	        delay = time(NULL) + 20 + (rand() % 10);
 		}
 
@@ -966,7 +998,7 @@ int run_node(int sock_fd, list * neighbourhood){
 
 
 // This function runs once, and sets the sock_fd as well as the neighbourhood
-int bootstrap_node(int * sock_fd, list * neighbourhood){
+int bootstrap_node(int * sock_fd){
 	printf(">> Boostraping node...\n");
 
 	struct sockaddr_in6 server_addr;
@@ -1012,11 +1044,9 @@ int bootstrap_node(int * sock_fd, list * neighbourhood){
 int main(int argc, const char *argv[]) {
 	printf(">> Starting node\n");
 
-	list neighbourhood;
-
 	int sock_fd;
-	bootstrap_node(&sock_fd, &neighbourhood);
-	run_node(sock_fd, &neighbourhood);
+	bootstrap_node(&sock_fd);
+	run_node(sock_fd);
 	close(sock_fd);
 
     return 0;

src/node.h

@@ -73,6 +73,8 @@ int validate_tlv(char *data, int pos, int16_t packet_len);
 
 int update_neighbours();
 
+int ask_for_peers(int socket_num);
+
 int work_with_tlvs(char * data, int16_t packet_len, struct sockaddr_in6 *sender, int socket_num);
 
 int add_tlv(packet *pack, tlv *tlv, struct sockaddr_in6 *dest, int socket_num);
@@ -82,7 +84,7 @@ int send_packet(char *packet_buff, int16_t length, struct sockaddr_in6 *dest, in
 int send_single_tlv(tlv *tlv, struct sockaddr_in6 *dest, int socket_num);
 
 // This function is in charge of saying how and what goes where.
-int run_node(int sock_fd, list * neighbourhood);
+int run_node(int sock_fd);
 
 /* Takes a TLV and sends it over to everyone in the list of addresses.
  * Returns -1 in case of error, 0 otherwise.
@@ -97,24 +99,24 @@ int send_tlvs(struct list * tlv_list, int16_t length, struct sockaddr_in6 * dest
 /* Check our peer list. If we have less than 5 peers, send out a
     TLV NEIGHBOUR_REQUEST to a random peer
 */
-int t_ask_for_more_peers(list * neighbourhood, int sock_fd);
+int t_ask_for_more_peers(int sock_fd);
 
 /* We look at every peer, if he is marked as is_temporary, AND we didn't get a
     packet from him in the last 70 sec, we remove him from the list.
 */
-int t_update_neighbours(list * neighbourhood);
+int t_update_neighbours();
 
 /* We send out a TLV Network Hash to every peer, and we expect getting a TLV
     Network state from each of them.
 */
-int t_get_network_state(list * neighbourhoodn, int sock_fd);
+int t_get_network_state(int sock_fd);
 
 // This function adds a message to the message table.
 int add_message(char * message, int message_len);
 
 // This functions creates the structures needed for the rest of the project,
 // creates the socket, and returns all of it.
-int bootstrap_node(int * sock_fd, list * neighbourhood);
+int bootstrap_node(int * sock_fd);
 
 // Helper functions
 int len_list(list *l);