4 files changed, 54 insertions, 8 deletions

diff --git a/toxcore/LAN_discovery.c b/toxcore/LAN_discovery.c
index dbce762e..5ab5b0e1 100644
--- a/toxcore/LAN_discovery.c
+++ b/toxcore/LAN_discovery.c
@@ -227,18 +227,43 @@ static IP broadcast_ip(sa_family_t family_socket, sa_family_t family_broadcast)
     return ip;
 }
 
+/* Is IP a local ip or not. */
+_Bool Local_ip(IP ip)
+{
+    if (ip.family == AF_INET) {
+        IP4 ip4 = ip.ip4;
+
+        /* Loopback. */
+        if (ip4.uint8[0] == 127)
+            return 1;
+    } else {
+        /* embedded IPv4-in-IPv6 */
+        if (IPV6_IPV4_IN_V6(ip.ip6)) {
+            IP ip4;
+            ip4.family = AF_INET;
+            ip4.ip4.uint32 = ip.ip6.uint32[3];
+            return Local_ip(ip4);
+        }
+
+        /* localhost in IPv6 (::1) */
+        if (ip.ip6.uint64[0] == 0 && ip.ip6.uint32[2] == 0 && ip.ip6.uint32[3] == htonl(1))
+            return 1;
+    }
+
+    return 0;
+}
+
 /*  return 0 if ip is a LAN ip.
  *  return -1 if it is not.
  */
 int LAN_ip(IP ip)
 {
+    if (Local_ip(ip))
+        return 0;
+
     if (ip.family == AF_INET) {
         IP4 ip4 = ip.ip4;
 
-        /* Loopback. */
-        if (ip4.uint8[0] == 127)
-            return 0;
-
         /* 10.0.0.0 to 10.255.255.255 range. */
         if (ip4.uint8[0] == 10)
             return 0;
@@ -276,10 +301,6 @@ int LAN_ip(IP ip)
             ip4.ip4.uint32 = ip.ip6.uint32[3];
             return LAN_ip(ip4);
         }
-
-        /* localhost in IPv6 (::1) */
-        if (ip.ip6.uint64[0] == 0 && ip.ip6.uint32[2] == 0 && ip.ip6.uint32[3] == htonl(1))
-            return 0;
     }
 
     return -1;
diff --git a/toxcore/LAN_discovery.h b/toxcore/LAN_discovery.h
index 5243bd93..358bea2f 100644
--- a/toxcore/LAN_discovery.h
+++ b/toxcore/LAN_discovery.h
@@ -40,6 +40,9 @@ void LANdiscovery_init(DHT *dht);
 /* Clear packet handlers. */
 void LANdiscovery_kill(DHT *dht);
 
+/* Is IP a local ip or not. */
+_Bool Local_ip(IP ip);
+
 /* checks if a given IP isn't routable
  *
  *  return 0 if ip is a LAN ip.
diff --git a/toxcore/friend_connection.c b/toxcore/friend_connection.c
index de34e570..7dd8e3e3 100644
--- a/toxcore/friend_connection.c
+++ b/toxcore/friend_connection.c
@@ -158,6 +158,20 @@ int friend_add_tcp_relay(Friend_Connections *fr_c, int friendcon_id, IP_Port ip_
     if (!friend_con)
         return -1;
 
+    /* Local ip means that they are hosting a TCP relay. */
+    if (Local_ip(ip_port.ip)) {
+        if (friend_con->dht_ip_port.ip.family != 0) {
+            ip_port.ip = friend_con->dht_ip_port.ip;
+        } else {
+            if (memcmp(friend_con->dht_temp_pk, public_key, crypto_box_PUBLICKEYBYTES) == 0) {
+                friend_con->hosting_tcp_relay = 0;
+                return 0;
+            } else {
+                return -1;
+            }
+        }
+    }
+
     unsigned int i;
 
     uint16_t index = friend_con->tcp_relay_counter % FRIEND_MAX_STORED_TCP_RELAYS;
@@ -268,6 +282,11 @@ static void dht_ip_callback(void *object, int32_t number, IP_Port ip_port)
     set_direct_ip_port(fr_c->net_crypto, friend_con->crypt_connection_id, ip_port, 1);
     friend_con->dht_ip_port = ip_port;
     friend_con->dht_ip_port_lastrecv = unix_time();
+
+    if (friend_con->hosting_tcp_relay) {
+        friend_add_tcp_relay(fr_c, number, ip_port, friend_con->dht_temp_pk);
+        friend_con->hosting_tcp_relay = 0;
+    }
 }
 
 static void change_dht_pk(Friend_Connections *fr_c, int friendcon_id, const uint8_t *dht_public_key)
@@ -317,6 +336,7 @@ static int handle_status(void *object, int number, uint8_t status)
 
         friend_con->status = FRIENDCONN_STATUS_CONNECTING;
         friend_con->crypt_connection_id = -1;
+        friend_con->hosting_tcp_relay = 0;
     }
 
     if (call_cb) {
diff --git a/toxcore/friend_connection.h b/toxcore/friend_connection.h
index baca4b76..32e947ac 100644
--- a/toxcore/friend_connection.h
+++ b/toxcore/friend_connection.h
@@ -96,6 +96,8 @@ typedef struct {
 
     Node_format tcp_relays[FRIEND_MAX_STORED_TCP_RELAYS];
     uint16_t tcp_relay_counter;
+
+    _Bool hosting_tcp_relay;
 } Friend_Conn;