/**
* Send message block to IP:port.
*
* @param us the UDP scheduler
* @param mb the message to send
* @param to the IP:port destination of the message
* @param tx the TX stack sending the message
* @param cb callback actions on the datagram
*
* @return TRUE if message was sent or dropped, FALSE if there is no more
* bandwidth to send anything.
*/
static bool
udp_sched_mb_sendto(udp_sched_t *us, pmsg_t *mb, const gnet_host_t *to,
const txdrv_t *tx, const struct tx_dgram_cb *cb)
{
ssize_t r;
int len = pmsg_size(mb);
bio_source_t *bio = NULL;
if (0 == gnet_host_get_port(to))
return TRUE;
/*
* Check whether message still needs to be sent.
*/
if (!pmsg_hook_check(mb))
return TRUE; /* Dropped */
/*
* Select the proper I/O source depending on the network address type.
*/
switch (gnet_host_get_net(to)) {
case NET_TYPE_IPV4:
bio = us->bio[UDP_SCHED_IPv4];
break;
case NET_TYPE_IPV6:
bio = us->bio[UDP_SCHED_IPv6];
break;
case NET_TYPE_NONE:
case NET_TYPE_LOCAL:
g_assert_not_reached();
}
/*
* If there is no I/O source, then the socket to send that type of traffic
* was cleared, hence we simply need to discard the message.
*/
if (NULL == bio) {
udp_sched_log(4, "%p: discarding mb=%p (%d bytes) to %s",
us, mb, pmsg_size(mb), gnet_host_to_string(to));
return udp_tx_drop(tx, cb); /* TRUE, for "sent" */
}
/*
* OK, proceed if we have bandwidth.
*/
r = bio_sendto(bio, to, pmsg_start(mb), len);
if (r < 0) { /* Error, or no bandwidth */
if (udp_sched_write_error(us, to, mb, G_STRFUNC)) {
udp_sched_log(4, "%p: dropped mb=%p (%d bytes): %m",
us, mb, pmsg_size(mb));
return udp_tx_drop(tx, cb); /* TRUE, for "sent" */
}
udp_sched_log(3, "%p: no bandwidth for mb=%p (%d bytes)",
us, mb, pmsg_size(mb));
us->used_all = TRUE;
return FALSE;
}
if (r != len) {
g_warning("%s: partial UDP write (%zd bytes) to %s "
"for %d-byte datagram",
G_STRFUNC, r, gnet_host_to_string(to), len);
} else {
udp_sched_log(5, "%p: sent mb=%p (%d bytes) prio=%u",
us, mb, pmsg_size(mb), pmsg_prio(mb));
pmsg_mark_sent(mb);
if (cb->msg_account != NULL)
(*cb->msg_account)(tx->owner, mb);
inet_udp_record_sent(gnet_host_get_addr(to));
}
return TRUE; /* Message sent */
}
/**
* Enqueue message, which becomes owned by the queue.
*
* The data held in `to' is copied, so the structure can be reclaimed
* immediately by the caller.
*/
void
mq_udp_putq(mqueue_t *q, pmsg_t *mb, const gnet_host_t *to)
{
size_t size;
char *mbs;
uint8 function;
pmsg_t *mbe = NULL; /* Extended message with destination info */
bool error = FALSE;
mq_check_consistency(q);
dump_tx_udp_packet(to, mb);
again:
mq_check_consistency(q);
g_assert(mb);
g_assert(!pmsg_was_sent(mb));
g_assert(pmsg_is_unread(mb));
g_assert(q->ops == &mq_udp_ops); /* Is an UDP queue */
/*
* Trap messages enqueued whilst in the middle of an mq_clear() operation
* by marking them as sent and dropping them. Idem if queue was
* put in "discard" mode.
*/
if (q->flags & (MQ_CLEAR | MQ_DISCARD)) {
pmsg_mark_sent(mb); /* Let them think it was sent */
pmsg_free(mb); /* Drop message */
return;
}
mq_check(q, 0);
size = pmsg_size(mb);
if (size == 0) {
g_carp("%s: called with empty message", G_STRFUNC);
goto cleanup;
}
/*
* Protect against recursion: we must not invoke puthere() whilst in
* the middle of another putq() or we would corrupt the qlink array:
* Messages received during recursion are inserted into the qwait list
* and will be stuffed back into the queue when the initial putq() ends.
* --RAM, 2006-12-29
*/
if (q->putq_entered > 0) {
pmsg_t *extended;
if (debugging(20))
g_warning("%s: %s recursion detected (%u already pending)",
G_STRFUNC, mq_info(q), slist_length(q->qwait));
/*
* We insert extended messages into the waiting queue since we need
* the destination information as well.
*/
extended = mq_udp_attach_metadata(mb, to);
slist_append(q->qwait, extended);
return;
}
q->putq_entered++;
mbs = pmsg_start(mb);
function = gmsg_function(mbs);
gnet_stats_count_queued(q->node, function, mbs, size);
/*
* If queue is empty, attempt a write immediatly.
*/
if (q->qhead == NULL) {
ssize_t written;
if (pmsg_check(mb, q)) {
written = tx_sendto(q->tx_drv, mb, to);
} else {
gnet_stats_count_flowc(mbs, FALSE);
node_inc_txdrop(q->node); /* Dropped during TX */
written = (ssize_t) -1;
}
if ((ssize_t) -1 == written)
goto cleanup;
node_add_tx_given(q->node, written);
if ((size_t) written == size) {
if (GNET_PROPERTY(mq_udp_debug) > 5)
g_debug("MQ UDP sent %s",
gmsg_infostr_full(pmsg_start(mb), pmsg_written_size(mb)));
goto cleanup;
}
/*
* Since UDP respects write boundaries, the following can never
* happen in practice: either we write the whole datagram, or none
* of it.
*/
if (written > 0) {
g_warning(
"partial UDP write (%zu bytes) to %s for %zu-byte datagram",
written, gnet_host_to_string(to), size);
goto cleanup;
}
/* FALL THROUGH */
}
if (GNET_PROPERTY(mq_udp_debug) > 5)
g_debug("MQ UDP queued %s",
gmsg_infostr_full(pmsg_start(mb), pmsg_written_size(mb)));
/*
* Attach the destination information as metadata to the message, unless
* it is already known (possible only during unfolding of the queued data
* during re-entrant calls).
*
* This is later extracted via pmsg_get_metadata() on the extended
* message by the message queue to get the destination information.
*
* Then enqueue the extended message.
*/
if (NULL == mbe)
mbe = mq_udp_attach_metadata(mb, to);
q->cops->puthere(q, mbe, size);
mb = NULL;
/* FALL THROUGH */
cleanup:
if (mb) {
pmsg_free(mb);
mb = NULL;
}
/*
* When reaching that point with a zero putq_entered counter, it means
* we triggered an early error condition. Bail out.
*/
g_assert(q->putq_entered >= 0);
if (q->putq_entered == 0)
error = TRUE;
else
q->putq_entered--;
mq_check(q, 0);
/*
* If we're exiting here with no other putq() registered, then we must
* pop an item off the head of the list and iterate again.
*/
if (0 == q->putq_entered && !error) {
mbe = slist_shift(q->qwait);
if (mbe) {
struct mq_udp_info *mi = pmsg_get_metadata(mbe);
mb = mbe; /* An extended message "is-a" message */
to = &mi->to;
if (debugging(20))
g_warning(
"%s: %s flushing waiting to %s (%u still pending)",
G_STRFUNC, mq_info(q), gnet_host_to_string(to),
slist_length(q->qwait));
goto again;
}
}
return;
}