source: mainline/uspace/srv/net/tcp/rqueue.c@ fc3d4fd5

/*
 * Copyright (c) 2015 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup tcp
 * @{
 */

/**
 * @file Global segment receive queue
 */

#include <adt/prodcons.h>
#include <errno.h>
#include <io/log.h>
#include <stdbool.h>
#include <stdlib.h>
#include <fibril.h>
#include <fibril_synch.h>
#include "conn.h"
#include "pdu.h"
#include "rqueue.h"
#include "segment.h"
#include "tcp_type.h"
#include "ucall.h"

/** Transcode bounced segments.
 *
 * If defined, segments bounced via the internal debugging loopback will
 * be encoded to a PDU and the decoded. Otherwise they will be bounced back
 * directly without passing the encoder-decoder.
 */
#define BOUNCE_TRANSCODE

static prodcons_t rqueue;
static bool fibril_active;
static fibril_mutex_t lock;
static fibril_condvar_t cv;
static tcp_rqueue_cb_t *rqueue_cb;

/** Initialize segment receive queue. */
void tcp_rqueue_init(tcp_rqueue_cb_t *rcb)
{
        prodcons_initialize(&rqueue);
        fibril_mutex_initialize(&lock);
        fibril_condvar_initialize(&cv);
        fibril_active = false;
        rqueue_cb = rcb;
}

/** Finalize segment receive queue. */
void tcp_rqueue_fini(void)
{
        inet_ep2_t epp;

        inet_ep2_init(&epp);
        tcp_rqueue_insert_seg(&epp, NULL);

        fibril_mutex_lock(&lock);
        while (fibril_active)
                fibril_condvar_wait(&cv, &lock);
        fibril_mutex_unlock(&lock);
}

/** Bounce segment directy into receive queue without constructing the PDU.
 *
 * This is for testing purposes only.
 *
 * @param sp    Endpoint pair, oriented for transmission
 * @param seg   Segment
 */
void tcp_rqueue_bounce_seg(inet_ep2_t *epp, tcp_segment_t *seg)
{
        inet_ep2_t rident;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_rqueue_bounce_seg()");

#ifdef BOUNCE_TRANSCODE
        tcp_pdu_t *pdu;
        tcp_segment_t *dseg;

        if (tcp_pdu_encode(epp, seg, &pdu) != EOK) {
                log_msg(LOG_DEFAULT, LVL_WARN, "Not enough memory. Segment dropped.");
                return;
        }

        if (tcp_pdu_decode(pdu, &rident, &dseg) != EOK) {
                log_msg(LOG_DEFAULT, LVL_WARN, "Not enough memory. Segment dropped.");
                return;
        }

        tcp_pdu_delete(pdu);

        /** Insert decoded segment into rqueue */
        tcp_rqueue_insert_seg(&rident, dseg);
        tcp_segment_delete(seg);
#else
        /* Reverse the identification */
        tcp_ep2_flipped(epp, &rident);

        /* Insert segment back into rqueue */
        tcp_rqueue_insert_seg(&rident, seg);
#endif
}

/** Insert segment into receive queue.
 *
 * @param epp   Endpoint pair, oriented for reception
 * @param seg   Segment
 */
void tcp_rqueue_insert_seg(inet_ep2_t *epp, tcp_segment_t *seg)
{
        tcp_rqueue_entry_t *rqe;

        log_msg(LOG_DEFAULT, LVL_DEBUG2, "tcp_rqueue_insert_seg()");

        if (seg != NULL)
                tcp_segment_dump(seg);

        rqe = calloc(1, sizeof(tcp_rqueue_entry_t));
        if (rqe == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed allocating RQE.");
                return;
        }

        rqe->epp = *epp;
        rqe->seg = seg;

        prodcons_produce(&rqueue, &rqe->link);
}

/** Receive queue handler fibril. */
static int tcp_rqueue_fibril(void *arg)
{
        link_t *link;
        tcp_rqueue_entry_t *rqe;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_rqueue_fibril()");

        while (true) {
                link = prodcons_consume(&rqueue);
                rqe = list_get_instance(link, tcp_rqueue_entry_t, link);

                if (rqe->seg == NULL) {
                        free(rqe);
                        break;
                }

                rqueue_cb->seg_received(&rqe->epp, rqe->seg);
                free(rqe);
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG2, "tcp_rqueue_fibril() exiting");

        /* Finished */
        fibril_mutex_lock(&lock);
        fibril_active = false;
        fibril_mutex_unlock(&lock);
        fibril_condvar_broadcast(&cv);

        return 0;
}

/** Start receive queue handler fibril. */
void tcp_rqueue_fibril_start(void)
{
        fid_t fid;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_rqueue_fibril_start()");

        fid = fibril_create(tcp_rqueue_fibril, NULL);
        if (fid == 0) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed creating rqueue fibril.");
                return;
        }

        fibril_add_ready(fid);
        fibril_active = true;
}

/**
 * @}
 */