Authorize to change the source IP of the tunnels l2tp

[l2tpns.git] / l2tpns.c

diff --git a/l2tpns.c b/l2tpns.c
index 5f3b865..9db5bc3 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -182,6 +182,7 @@ config_descriptt config_values[] = {
        CONFIG("tundevicename", tundevicename, STRING),
 #ifdef LAC
        CONFIG("disable_lac_func", disable_lac_func, BOOL),
+       CONFIG("auth_tunnel_change_addr_src", auth_tunnel_change_addr_src, BOOL),
        CONFIG("bind_address_remotelns", bind_address_remotelns, IPv4),
        CONFIG("bind_portremotelns", bind_portremotelns, SHORT),
 #endif
@@ -3229,10 +3230,22 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                if (session[s].forwardtosession)
                {
                        LOG(5, s, t, "Forwarding data session to session %u\n", session[s].forwardtosession);
-                       // Forward to LAC or Remote LNS session
+                       // Forward to LAC/BAS or Remote LNS session
                        lac_session_forward(buf, len, s, proto, addr->sin_addr.s_addr, addr->sin_port);
                        return;
                }
+               else if (config->auth_tunnel_change_addr_src)
+               {
+                       if (tunnel[t].ip != ntohl(addr->sin_addr.s_addr) &&
+                               tunnel[t].port == ntohs(addr->sin_port))
+                       {
+                               // The remotes BAS are a clustered l2tpns server and the source IP has changed
+                               LOG(5, s, t, "The tunnel IP source (%s) has changed by new IP (%s)\n",
+                                       fmtaddr(htonl(tunnel[t].ip), 0), fmtaddr(addr->sin_addr.s_addr, 0));
+
+                               tunnel[t].ip = ntohl(addr->sin_addr.s_addr);
+                       }
+               }
 #endif /* LAC */
 
                if (s && !session[s].opened)    // Is something wrong??