1 files changed, 16 insertions, 42 deletions

diff --git a/src/vpn/gnunet-service-vpn.c b/src/vpn/gnunet-service-vpn.c
index 0d236975e..153327b9b 100644
--- a/src/vpn/gnunet-service-vpn.c
+++ b/src/vpn/gnunet-service-vpn.c
@@ -32,10 +32,6 @@
  *
  * Features:
  * - add back ICMP support (especially needed for IPv6)
- *
- * Code cleanup:
- * - consider moving IP-header building / checksumming code into shared library
- *   with dns/exit/vpn (libgnunettun_tcpip?)
  */
 #include "platform.h"
 #include "gnunet_util_lib.h"
@@ -1436,7 +1432,10 @@ receive_udp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
         else
           udp->dpt = reply->destination_port;
         udp->len = htons (mlen + sizeof (struct GNUNET_TUN_UdpHeader));
-        udp->crc = 0; // FIXME: optional, but we might want to calculate this one anyway
+        GNUNET_TUN_calculate_udp4_checksum (ipv4,
+                                            udp,
+                                            &reply[1],
+                                            mlen);
         memcpy (&udp[1],
                 &reply[1],
                 mlen);
@@ -1464,15 +1463,11 @@ receive_udp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
         msg->size = htons (size);
         tun->flags = htons (0);
         tun->proto = htons (ETH_P_IPV6);
-        ipv6->traffic_class_h = 0;
-        ipv6->version = 6;
-        ipv6->traffic_class_l = 0;
-        ipv6->flow_label = 0;
-        ipv6->payload_length = htons (sizeof (struct GNUNET_TUN_UdpHeader) + sizeof (struct GNUNET_TUN_IPv6Header) + mlen);
-        ipv6->next_header = IPPROTO_UDP;
-        ipv6->hop_limit = 255;
-        ipv6->source_address = ts->destination_ip.v6;
-        ipv6->destination_address = ts->source_ip.v6;
+        GNUNET_TUN_initialize_ipv6_header (ipv6,
+                                           IPPROTO_UDP,
+                                           sizeof (struct GNUNET_TUN_UdpHeader) + mlen,
+                                           &ts->destination_ip.v6,
+                                           &ts->source_ip.v6);
         if (0 == ntohs (reply->source_port))
           udp->spt = htons (ts->destination_port);
         else
@@ -1482,24 +1477,12 @@ receive_udp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
         else
           udp->dpt = reply->destination_port;
         udp->len = htons (mlen + sizeof (struct GNUNET_TUN_UdpHeader));
-        udp->crc = 0;
+        GNUNET_TUN_calculate_udp6_checksum (ipv6,
+                                            udp,
+                                            &reply[1], mlen);
         memcpy (&udp[1],
                 &reply[1],
                 mlen);
-        {
-          uint32_t sum = 0;
-          sum =
-            GNUNET_CRYPTO_crc16_step (sum, &ipv6->source_address, 
-                                      sizeof (struct in6_addr) * 2);
-          uint32_t tmp = udp->len;
-          sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
-          tmp = htons (IPPROTO_UDP);
-          sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
-          sum = GNUNET_CRYPTO_crc16_step (sum, 
-                                          udp,
-                                          ntohs (udp->len));
-          udp->crc = GNUNET_CRYPTO_crc16_finish (sum);
-        }
         (void) GNUNET_HELPER_send (helper_handle,
                                    msg,
                                    GNUNET_YES,
@@ -1596,22 +1579,13 @@ receive_tcp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
         *tcp = data->tcp_header;
         tcp->spt = htons (ts->destination_port);
         tcp->dpt = htons (ts->source_port);
-        tcp->crc = 0;
+        GNUNET_TUN_calculate_tcp4_checksum (ipv4,
+                                            tcp,
+                                            &data[1],
+                                            mlen);
         memcpy (&tcp[1],
                 &data[1],
                 mlen);
-        {
-          uint32_t sum = 0;
-          uint32_t tmp;
-          
-          sum = GNUNET_CRYPTO_crc16_step (sum, 
-                                          &ipv4->source_address,
-                                          2 * sizeof (struct in_addr));   
-          tmp = htonl ((IPPROTO_TCP << 16) | (mlen + sizeof (struct GNUNET_TUN_TcpHeader)));
-          sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
-          sum = GNUNET_CRYPTO_crc16_step (sum, tcp, mlen + sizeof (struct GNUNET_TUN_TcpHeader));
-          tcp->crc = GNUNET_CRYPTO_crc16_finish (sum);
-        }
         (void) GNUNET_HELPER_send (helper_handle,
                                    msg,
                                    GNUNET_YES,