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authorChristian Grothoff <christian@grothoff.org>2019-04-16 22:18:14 +0200
committerChristian Grothoff <christian@grothoff.org>2019-04-16 22:18:14 +0200
commit4e1322ed06444b96d28860fd5909db6af1bf848e (patch)
treee52d9d2b8475ae3021bb698dba9849912d8fa2d6 /src/transport/gnunet-service-tng.c
parent3266ea560ea1b243810dce4d46ee2889da7b4f6c (diff)
handle forwarding of DVBox messages
Diffstat (limited to 'src/transport/gnunet-service-tng.c')
-rw-r--r--src/transport/gnunet-service-tng.c102
1 files changed, 94 insertions, 8 deletions
diff --git a/src/transport/gnunet-service-tng.c b/src/transport/gnunet-service-tng.c
index 53b9ba0c8..9c4672609 100644
--- a/src/transport/gnunet-service-tng.c
+++ b/src/transport/gnunet-service-tng.c
@@ -35,7 +35,6 @@
* Implement next:
* - DV data structures:
* + using DV routes!
- * - handling of DV-boxed messages that need to be forwarded
* - route_message implementation, including using DV data structures
* (but not when routing certain message types, like DV learn,
* MUST pay attention to content here -- or pass extra flags?)
@@ -4763,7 +4762,8 @@ handle_dv_learn (void *cls,
/* continue communicator here, everything else can happen asynchronous! */
finish_cmc_handling (cmc);
- // FIXME: should we bother to verify _every_ DV initiator signature?
+ /* OPTIMIZE-FIXME: Technically, we only need to bother checking
+ the initiator signature if we send the message back to the initiator... */
if (GNUNET_OK !=
validate_dv_initiator_signature (&dvl->initiator,
&dvl->challenge,
@@ -4773,7 +4773,7 @@ handle_dv_learn (void *cls,
return;
}
// FIXME: asynchronously (!) verify hop-by-hop signatures!
- // => if signature verification load too high, implement random drop strategy!
+ // => if signature verification load too high, implement random drop strategy!?
do_fwd = GNUNET_YES;
if (0 == GNUNET_memcmp (&GST_my_identity,
@@ -4953,11 +4953,68 @@ check_dv_box (void *cls,
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
+ if (0 ==
+ GNUNET_memcmp (&dvb->origin,
+ &GST_my_identity))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
return GNUNET_YES;
}
/**
+ * Create a DV Box message and queue it for transmission to
+ * @ea next_hop.
+ *
+ * @param next_hop peer to receive the message next
+ * @param total_hops how many hops did the message take so far
+ * @param num_hops length of the @a hops array
+ * @param origin origin of the message
+ * @param hops next peer(s) to the destination, including destination
+ * @param payload payload of the box
+ * @param payload_size number of bytes in @a payload
+ */
+static void
+forward_dv_box (struct Neighbour *next_hop,
+ uint16_t total_hops,
+ uint16_t num_hops,
+ const struct GNUNET_PeerIdentity *origin,
+ const struct GNUNET_PeerIdentity *hops,
+ const void *payload,
+ uint16_t payload_size)
+{
+ struct TransportDVBox *dvb;
+ struct GNUNET_PeerIdentity *dhops;
+
+ GNUNET_assert (UINT16_MAX <
+ sizeof (struct TransportDVBox) +
+ sizeof (struct GNUNET_PeerIdentity) * num_hops +
+ payload_size);
+ dvb = GNUNET_malloc (sizeof (struct TransportDVBox) +
+ sizeof (struct GNUNET_PeerIdentity) * num_hops +
+ payload_size);
+ dvb->header.size = htons (sizeof (struct TransportDVBox) +
+ sizeof (struct GNUNET_PeerIdentity) * num_hops +
+ payload_size);
+ dvb->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_DV_BOX);
+ dvb->total_hops = htons (total_hops);
+ dvb->num_hops = htons (num_hops);
+ dvb->origin = *origin;
+ dhops = (struct GNUNET_PeerIdentity *) &dvb[1];
+ memcpy (dhops,
+ hops,
+ num_hops * sizeof (struct GNUNET_PeerIdentity));
+ memcpy (&dhops[num_hops],
+ payload,
+ payload_size);
+ route_message (&next_hop->pid,
+ &dvb->header);
+}
+
+
+/**
* Communicator gave us a DV box. Process the request.
*
* @param cls a `struct CommunicatorMessageContext` (must call #finish_cmc_handling() when done)
@@ -4975,10 +5032,39 @@ handle_dv_box (void *cls,
if (num_hops > 0)
{
- // FIXME: if we are not the target, shorten path and forward along.
- // Try from the _end_ of hops array if we know the given
- // neighbour (shortening the path!).
- // NOTE: increment total_hops!
+ /* We're trying from the end of the hops array, as we may be
+ able to find a shortcut unknown to the origin that way */
+ for (int i=num_hops-1;i>=0;i--)
+ {
+ struct Neighbour *n;
+
+ if (0 ==
+ GNUNET_memcmp (&hops[i],
+ &GST_my_identity))
+ {
+ GNUNET_break_op (0);
+ finish_cmc_handling (cmc);
+ return;
+ }
+ n = GNUNET_CONTAINER_multipeermap_get (neighbours,
+ &hops[i]);
+ if (NULL == n)
+ continue;
+ forward_dv_box (n,
+ ntohs (dvb->total_hops) + 1,
+ num_hops - i - 1, /* number of hops left */
+ &dvb->origin,
+ &hops[i+1], /* remaining hops */
+ (const void *) &dvb[1],
+ size);
+ finish_cmc_handling (cmc);
+ return;
+ }
+ /* Woopsie, next hop not in neighbours, drop! */
+ GNUNET_STATISTICS_update (GST_stats,
+ "# DV Boxes dropped: next hop unknown",
+ 1,
+ GNUNET_NO);
finish_cmc_handling (cmc);
return;
}
@@ -5399,7 +5485,7 @@ tracker_update_in_cb (void *cls)
rsize = (0 == queue->mtu) ? IN_PACKET_SIZE_WITHOUT_MTU : queue->mtu;
in_delay = GNUNET_BANDWIDTH_tracker_get_delay (&queue->tracker_in,
- rsize);
+ rsize);
// FIXME: how exactly do we do inbound flow control?
}