check/add/update neighbours

src/node.c

@@ -51,6 +51,63 @@ neighbour_peer *get_random_neighbour() {
     return (neighbour_peer*) tmp->data;
 }
 
+// Search for this peer in the neighbour table
+neighbour_peer *get_neighbour(struct in6_addr *ip) {
+    // Look for neighbour
+    list *tmp = neighbour_list;
+    neighbour_peer *peer;
+
+    while(tmp != NULL) {
+        // check for same ip and same port
+        peer = (neighbour_peer*) tmp->data;
+
+        if(memcmp(&peer->ip, ip, sizeof(struct in6_addr)) == 0)
+            return peer;
+
+        // if they differ, get next peer
+        tmp = tmp->next;
+    }
+
+    return NULL;
+}
+
+// Return -1 if the peer could not be added, 0 if it could or if it was already in the table
+int add_n_update_neighbour(struct in6_addr *ip) {
+    neighbour_peer *peer = get_neighbour(ip);
+    struct timeval curtime;
+
+    // peer is not in the neighbour list so we try to add it
+    if(ip == NULL) {
+        // check if there are less than 15 neighbours
+        if(len_list(neighbour_list) == 15)
+            return -1;
+
+        // if there are less, initialize the new peer to add to the list
+        peer = (neighbour_peer*) malloc(sizeof(neighbour_peer));
+        memcpy(&peer->ip, ip, sizeof(struct in6_addr));
+        peer->port = LISTEN_PORT;
+        peer->is_temporary = 1;
+
+        // set last_seen time
+        gettimeofday(&curtime, NULL);
+        memcpy(&peer->last_seen, &curtime, sizeof(struct timeval));
+
+        // set new peer as head of list
+        list *node = (list*) malloc(sizeof(list));
+        node->data = (void*) peer;
+        node->next = neighbour_list;
+        neighbour_list = node;
+
+        return 0;
+    }
+
+    // if the peer was already in the list, update it
+    gettimeofday(&curtime, NULL);
+    memcpy(&peer->last_seen, &curtime, sizeof(struct timeval));
+
+    return 0;
+}
+
 // get data associated with id, if it doesn't exist return NULL
 pub_data *get_data(int64_t id) {
 	list *tmp = data_list;
@@ -702,7 +759,11 @@ int listen_for_packets(char * received_data_buffer, int received_data_len, struc
 		return -1;
     }
 
-    // TODO : Add the neighbour check here.
+    // Neighbour check
+    if(add_n_update_neighbour(sender) == -1) {
+        fprintf(stderr, ">> Maximum number of neighbour peers reached, aborting this packet.\n");
+        return -1;
+    }
 
     // struct tlv_list received_tlvs;
     // if (validate_tlvs(formated_rec_datagram) < 0)

src/node.h

@@ -10,6 +10,7 @@
 #include <netinet/in.h>
 #include <string.h>
 #include <time.h>
+#include <sys/time.h>
 #include <stdint.h>
 #include <net/if.h>
 
@@ -121,6 +122,12 @@ int len_list(list *l);
 
 neighbour_peer *get_random_neighbour();
 
+// Search for this peer in the neighbour table
+neighbour_peer *get_neighbour(struct in6_addr *ip);
+
+// Return -1 if the peer could not be added, 0 if it could or if it was already in the table
+int add_n_update_neighbour(struct in6_addr *ip);
+
 // get data associated with id, if it doesn't exist return NULL
 pub_data *get_data(int64_t id);