3 files changed, 32 insertions, 1 deletions

diff --git a/toxcore/Messenger.c b/toxcore/Messenger.c
index 1a7fc230..5e9758dd 100644
--- a/toxcore/Messenger.c
+++ b/toxcore/Messenger.c
@@ -1454,6 +1454,17 @@ int m_msi_packet(Messenger *m, int friendnumber, uint8_t *data, uint16_t length)
     return write_cryptpacket_id(m, friendnumber, PACKET_ID_MSI, data, length);
 }
 
+/* Function to filter out some friend requests*/
+static int friend_already_added(uint8_t * client_id, void * data)
+{
+    Messenger *m = data;
+
+    if (getfriend_id(m, client_id) == -1)
+        return 0;
+
+    return -1;
+}
+
 /* Send a LAN discovery packet every LAN_DISCOVERY_INTERVAL seconds. */
 static void LANdiscovery(Messenger *m)
 {
@@ -1503,6 +1514,8 @@ Messenger *new_messenger(uint8_t ipv6enabled)
     friendreq_init(&(m->fr), m->net_crypto);
     LANdiscovery_init(m->dht);
     set_nospam(&(m->fr), random_int());
+    set_filter_function(&(m->fr), &friend_already_added, m);
+
     networking_registerhandler(m->net, NET_PACKET_GROUP_CHATS, &handle_group, m);
 
     return m;
diff --git a/toxcore/friend_requests.c b/toxcore/friend_requests.c
index 67977c23..589bd315 100644
--- a/toxcore/friend_requests.c
+++ b/toxcore/friend_requests.c
@@ -96,6 +96,12 @@ void callback_friendrequest(Friend_Requests *fr, void (*function)(uint8_t *, uin
     fr->handle_friendrequest_isset = 1;
     fr->handle_friendrequest_userdata = userdata;
 }
+/* Set the function used to check if a friend request should be displayed to the user or not. */
+void set_filter_function(Friend_Requests *fr, int (*function)(uint8_t *, void *), void *userdata)
+{
+    fr->filter_function = function;
+    fr->filter_function_userdata = userdata;
+}
 
 /* Add to list of received friend requests. */
 static void addto_receivedlist(Friend_Requests *fr, uint8_t *client_id)
@@ -141,6 +147,10 @@ static int friendreq_handlepacket(void *object, IP_Port source, uint8_t *source_
     if (memcmp(packet, &fr->nospam, sizeof(fr->nospam)) != 0)
         return 1;
 
+    if (fr->filter_function)
+        if ((*fr->filter_function)(source_pubkey, fr->filter_function_userdata) != 0)
+            return 1;
+
     addto_receivedlist(fr, source_pubkey);
     (*fr->handle_friendrequest)(source_pubkey, packet + 4, length - 4, fr->handle_friendrequest_userdata);
     return 0;
diff --git a/toxcore/friend_requests.h b/toxcore/friend_requests.h
index b5c46056..c655669d 100644
--- a/toxcore/friend_requests.h
+++ b/toxcore/friend_requests.h
@@ -34,6 +34,8 @@ typedef struct {
     uint8_t handle_friendrequest_isset;
     void *handle_friendrequest_userdata;
 
+    int (*filter_function)(uint8_t *, void *);
+    void *filter_function_userdata;
     /* NOTE: The following is just a temporary fix for the multiple friend requests received at the same time problem.
      *  TODO: Make this better (This will most likely tie in with the way we will handle spam.)
      */
@@ -53,11 +55,17 @@ void set_nospam(Friend_Requests *fr, uint32_t num);
 uint32_t get_nospam(Friend_Requests *fr);
 
 /* Set the function that will be executed when a friend request for us is received.
- *  Function format is function(uint8_t * public_key, uint8_t * data, uint16_t length)
+ *  Function format is function(uint8_t * public_key, uint8_t * data, uint16_t length, void * userdata)
  */
 void callback_friendrequest(Friend_Requests *fr, void (*function)(uint8_t *, uint8_t *, uint16_t, void *),
                             void *userdata);
 
+/* Set the function used to check if a friend request should be displayed to the user or not.
+ * Function format is int function(uint8_t * public_key, void * userdata)
+ * It must return 0 if the request is ok (anything else if it is bad.)
+ */
+void set_filter_function(Friend_Requests *fr, int (*function)(uint8_t *, void *), void *userdata);
+
 /* Sets up friendreq packet handlers. */
 void friendreq_init(Friend_Requests *fr, Net_Crypto *c);