Prefer the 'server identifier' attribute address to send DHCP requests to

[strongswan.git] / src / libcharon / plugins / dhcp / dhcp_socket.c

diff --git a/src/libcharon/plugins/dhcp/dhcp_socket.c b/src/libcharon/plugins/dhcp/dhcp_socket.c
index 36678f0..e1e83d6 100644 (file)
--- a/src/libcharon/plugins/dhcp/dhcp_socket.c
+++ b/src/libcharon/plugins/dhcp/dhcp_socket.c
@@ -463,8 +463,6 @@ static void handle_offer(private_dhcp_socket_t *this, dhcp_t *dhcp, int optlen)
 
        offer = host_create_from_chunk(AF_INET,
                                        chunk_from_thing(dhcp->your_address), 0);
-       server = host_create_from_chunk(AF_INET,
-                                       chunk_from_thing(dhcp->server_address), DHCP_SERVER_PORT);
 
        this->mutex->lock(this->mutex);
        enumerator = this->discover->create_enumerator(this->discover);
@@ -472,11 +470,8 @@ static void handle_offer(private_dhcp_socket_t *this, dhcp_t *dhcp, int optlen)
        {
                if (transaction->get_id(transaction) == dhcp->transaction_id)
                {
-                       DBG1(DBG_CFG, "received DHCP OFFER %H from %H", offer, server);
                        this->discover->remove_at(this->discover, enumerator);
                        this->request->insert_last(this->request, transaction);
-                       transaction->set_address(transaction, offer->clone(offer));
-                       transaction->set_server(transaction, server->clone(server));
                        break;
                }
        }
@@ -505,9 +500,22 @@ static void handle_offer(private_dhcp_socket_t *this, dhcp_t *dhcp, int optlen)
                                                chunk_create((char*)&option->data[pos], 4));
                                }
                        }
+                       if (option->type == DHCP_SERVER_ID && option->len == 4)
+                       {
+                               server = host_create_from_chunk(AF_INET,
+                                                       chunk_create(option->data, 4), DHCP_SERVER_PORT);
+                       }
                        optlen -= optsize;
                        optpos += optsize;
                }
+               if (!server)
+               {
+                       server = host_create_from_chunk(AF_INET,
+                               chunk_from_thing(dhcp->server_address), DHCP_SERVER_PORT);
+               }
+               DBG1(DBG_CFG, "received DHCP OFFER %H from %H", offer, server);
+               transaction->set_address(transaction, offer->clone(offer));
+               transaction->set_server(transaction, server->clone(server));
        }
        this->mutex->unlock(this->mutex);
        this->condvar->broadcast(this->condvar);