/**
* Flush current /QH2.
*
* Depending how the QH2 builder is configured, this either sends the message
* to the target node or invokes a processing callback.
*/
static void
g2_build_qh2_flush(struct g2_qh2_builder *ctx)
{
pmsg_t *mb;
g_assert(ctx != NULL);
g_assert(ctx->t != NULL);
g_assert((ctx->n != NULL) ^ (ctx->cb != NULL));
/*
* Restore the order of children in the root packet to be the order we
* used when we added the nodes, since we prepend new children.
*/
g2_tree_reverse_children(ctx->t);
/*
* If sending over UDP, ask for reliable delivery of the query hit.
* To be able to monitor the fate of the message, we asssociate a free
* routine to it.
*/
if (ctx->to_udp) {
struct g2_qh2_pmsg_info *pmi;
WALLOC0(pmi);
pmi->magic = G2_QH2_PMI_MAGIC;
pmi->hub_id = nid_ref(NODE_ID(ctx->hub));
mb = g2_build_pmsg_extended(ctx->t, g2_qh2_pmsg_free, pmi);
pmsg_mark_reliable(mb);
} else {
mb = g2_build_pmsg(ctx->t);
}
if (GNET_PROPERTY(g2_debug) > 3) {
g_debug("%s(): flushing the following hit for "
"Q2 #%s to %s%s (%d bytes):",
G_STRFUNC, guid_hex_str(ctx->muid),
NULL == ctx->n ?
stacktrace_function_name(ctx->cb) : node_infostr(ctx->n),
NULL == ctx->n ? "()" : "", pmsg_size(mb));
g2_tfmt_tree_dump(ctx->t, stderr, G2FMT_O_PAYLOAD | G2FMT_O_PAYLEN);
}
if (ctx->n != NULL)
g2_node_send(ctx->n, mb);
else
(*ctx->cb)(mb, ctx->arg);
ctx->messages++;
ctx->current_size = 0;
g2_tree_free_null(&ctx->t);
}
/**
* Send a datagram to the specified node, made of `len' bytes from `buf',
* forming a valid Gnutella message, with a "control" priority.
*/
void
udp_ctrl_send_msg(const gnutella_node_t *n, const void *buf, int len)
{
pmsg_t *mb;
g_assert(NODE_IS_UDP(n));
g_return_if_fail(n->outq);
mb = gmsg_to_ctrl_pmsg(buf, len);
if (NODE_CAN_SR_UDP(n))
pmsg_mark_reliable(mb); /* Send reliably if node supports it */
mq_udp_node_putq(n->outq, mb, n);
}
/**
* Send a message to specified UDP node.
*
* It is up to the caller to clone the message if needed, otherwise the
* node's queue becomes the sole owner of the message and will pmsg_free() it.
*/
void
udp_send_mb(const gnutella_node_t *n, pmsg_t *mb)
{
if (NULL == n || NULL == n->outq) {
pmsg_free(mb);
/* emit warnings */
g_return_if_fail(n);
g_return_if_fail(n->outq);
g_assert_not_reached();
}
g_assert(NODE_IS_UDP(n));
if (NODE_CAN_SR_UDP(n))
pmsg_mark_reliable(mb); /* Send reliably if node supports it */
mq_udp_node_putq(n->outq, mb, n);
}
/**
* Send a datagram to the specified node, made of `len' bytes from `buf',
* forming a valid Gnutella message.
*/
void
udp_send_msg(const gnutella_node_t *n, const void *buf, int len)
{
pmsg_t *mb;
g_assert(NODE_IS_UDP(n));
g_return_if_fail(n->outq);
/*
* If message is directed to a UDP node that can do semi-reliable UDP,
* then turn on reliability on the message.
*/
mb = gmsg_to_pmsg(buf, len);
if (NODE_CAN_SR_UDP(n))
pmsg_mark_reliable(mb);
mq_udp_node_putq(n->outq, mb, n);
}
/**
* 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;
}
