/**
* Attach meta information to supplied message block, returning a possibly
* new message block to use.
*/
static pmsg_t *
mq_udp_attach_metadata(pmsg_t *mb, const gnet_host_t *to)
{
pmsg_t *result;
if (pmsg_is_extended(mb)) {
struct mq_udp_info_extended *mi;
WALLOC(mi);
gnet_host_copy(&mi->to, to);
result = mb;
/*
* Replace original free routine with the new one, saving the original
* metadata and its free routine in the new metadata for later
* transparent dispatching at free time.
*/
mi->orig_free = pmsg_replace_ext(mb,
mq_udp_pmsg_free_extended, mi, &mi->orig_arg);
} else {
struct mq_udp_info *mi;
WALLOC(mi);
gnet_host_copy(&mi->to, to);
result = pmsg_clone_extend(mb, mq_udp_pmsg_free, mi);
pmsg_free(mb);
}
g_assert(pmsg_is_extended(result));
return result;
}
/**
* Mutate the message so that we can be notified about its freeing by
* the mq to which it will be sent to.
*/
static void
smsg_mutate(smsg_t *sb, struct gnutella_node *n)
{
struct smsg_info *smi;
pmsg_t *omb;
WALLOC(smi);
smi->shandle = sb->shandle;
smi->node_id = nid_ref(NODE_ID(n));
omb = sb->mb;
sb->mb = pmsg_clone_extend(omb, sq_pmsg_free, smi);
pmsg_free(omb);
}
/**
* Route query hits from one node to the other.
*/
void
dh_route(gnutella_node_t *src, gnutella_node_t *dest, int count)
{
pmsg_t *mb;
struct dh_pmsg_info *pmi;
const struct guid *muid;
dqhit_t *dh;
mqueue_t *mq;
g_assert(
gnutella_header_get_function(&src->header) == GTA_MSG_SEARCH_RESULTS);
g_assert(count >= 0);
if (!NODE_IS_WRITABLE(dest))
goto drop_shutdown;
muid = gnutella_header_get_muid(&src->header);
dh = dh_locate(muid);
g_assert(dh != NULL); /* Must have called dh_got_results() first! */
if (GNET_PROPERTY(dh_debug) > 19) {
g_debug("DH #%s got %d hit%s: "
"msg=%u, hits_recv=%u, hits_sent=%u, hits_queued=%u",
guid_hex_str(muid), count, plural(count),
dh->msg_recv, dh->hits_recv, dh->hits_sent,
dh->hits_queued);
}
mq = dest->outq;
/*
* Can we forward the message?
*/
switch (dh_can_forward(dh, mq, FALSE)) {
case DH_DROP_FC:
goto drop_flow_control;
case DH_DROP_THROTTLE:
goto drop_throttle;
case DH_DROP_TRANSIENT:
goto drop_transient;
case DH_FORWARD:
default:
break;
}
/*
* Allow message through.
*/
WALLOC(pmi);
pmi->hits = count;
dh->hits_queued += count;
dh->msg_queued++;
g_assert(dh->hits_queued >= UNSIGNED(count));
/*
* Magic: we create an extended version of a pmsg_t that contains a
* free routine, which will be invoked when the message queue frees
* the message.
*
* This enables us to track how much results we already queued/sent.
*/
if (NODE_IS_UDP(dest)) {
gnet_host_t to;
pmsg_t *mbe;
gnet_host_set(&to, dest->addr, dest->port);
/*
* With GUESS we may route back a query hit to an UDP node.
*/
if (GNET_PROPERTY(guess_server_debug) > 19) {
g_debug("GUESS sending %d hit%s (%s) for #%s to %s",
count, plural(count),
NODE_CAN_SR_UDP(dest) ? "reliably" :
NODE_CAN_INFLATE(dest) ? "possibly deflated" : "uncompressed",
guid_hex_str(muid), node_infostr(dest));
}
/*
* Attempt to compress query hit if the destination supports it.
*
* If we're going to send the hit using semi-reliable UDP, there's
* no need to compress beforehand, since the transport layer will
* attempt its own compression anyway.
*/
if (!NODE_CAN_SR_UDP(dest) && NODE_CAN_INFLATE(dest)) {
mb = gmsg_split_to_deflated_pmsg(&src->header, src->data,
src->size + GTA_HEADER_SIZE);
if (gnutella_header_get_ttl(pmsg_start(mb)) & GTA_UDP_DEFLATED)
gnet_stats_inc_general(GNR_UDP_TX_COMPRESSED);
} else {
mb = gmsg_split_to_pmsg(&src->header, src->data,
src->size + GTA_HEADER_SIZE);
}
mbe = pmsg_clone_extend(mb, dh_pmsg_free, pmi);
pmsg_free(mb);
if (NODE_CAN_SR_UDP(dest))
pmsg_mark_reliable(mbe);
mq_udp_putq(mq, mbe, &to);
} else {
mb = gmsg_split_to_pmsg_extend(&src->header, src->data,
src->size + GTA_HEADER_SIZE, dh_pmsg_free, pmi);
mq_tcp_putq(mq, mb, src);
if (GNET_PROPERTY(dh_debug) > 19) {
g_debug("DH enqueued %d hit%s for #%s to %s",
count, plural(count), guid_hex_str(muid),
node_infostr(dest));
}
}
return;
drop_shutdown:
gnet_stats_count_dropped(src, MSG_DROP_SHUTDOWN);
return;
drop_flow_control:
gnet_stats_count_dropped(src, MSG_DROP_FLOW_CONTROL);
gnet_stats_count_flowc(&src->header, TRUE);
return;
drop_throttle:
gnet_stats_count_dropped(src, MSG_DROP_THROTTLE);
return;
drop_transient:
gnet_stats_count_dropped(src, MSG_DROP_TRANSIENT);
return;
}
