/** * 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; }