+/**
+ * Forward the given payload message along the trail.
+ *
+ * @param next_target which direction along the trail should we forward
+ * @param trail_id which trail should we forward along
+ * @param have_path do we track the forwarding path?
+ * @param predecessor which peer do we tack on to the path?
+ * @param path path the message has taken so far along the trail
+ * @param path_length number of entries in @a path
+ * @param payload payload of the message
+ */
+static void
+forward_message_on_trail (struct FriendInfo *next_target,
+ const struct GNUNET_HashCode *trail_id,
+ int have_path,
+ const struct GNUNET_PeerIdentity *predecessor,
+ const struct GNUNET_PeerIdentity *path,
+ uint16_t path_length,
+ const struct GNUNET_MessageHeader *payload)
+{
+ struct GNUNET_MQ_Envelope *env;
+ struct TrailRouteMessage *trm;
+ struct GNUNET_PeerIdentity *new_path;
+ unsigned int plen;
+ uint16_t payload_len;
+
+ payload_len = ntohs (payload->size);
+ if (have_path)
+ {
+ plen = path_length + 1;
+ if (plen >= (GNUNET_SERVER_MAX_MESSAGE_SIZE
+ - payload_len
+ - sizeof (struct TrailRouteMessage))
+ / sizeof (struct GNUNET_PeerIdentity))
+ {
+ /* Should really not have paths this long... */
+ GNUNET_break_op (0);
+ plen = 0;
+ have_path = 0;
+ }
+ }
+ else
+ {
+ GNUNET_break_op (0 == path_length);
+ path_length = 0;
+ plen = 0;
+ }
+ env = GNUNET_MQ_msg_extra (trm,
+ payload_len +
+ plen * sizeof (struct GNUNET_PeerIdentity),
+ GNUNET_MESSAGE_TYPE_WDHT_TRAIL_ROUTE);
+ trm->record_path = htons (have_path);
+ trm->path_length = htons (plen);
+ trm->trail_id = *trail_id;
+ new_path = (struct GNUNET_PeerIdentity *) &trm[1];
+ if (have_path)
+ {
+ GNUNET_memcpy (new_path,
+ path,
+ path_length * sizeof (struct GNUNET_PeerIdentity));
+ new_path[path_length] = *predecessor;
+ }
+ GNUNET_memcpy (&new_path[plen],
+ payload,
+ payload_len);
+ GNUNET_MQ_send (next_target->mq,
+ env);
+}
+
+