Exemple #1
0
/**
 * @brief Get a node from the queue.
 *
 * @param queue The target queue.
 * @return A pointer to the node or NULL for no node to get.
 */
static struct buf_node *get_node_from(sq_queue_t *queue)
{
    struct buf_node *node = NULL;
    irqstate_t flags = irqsave();

    if (sq_empty(queue)) {
        irqrestore(flags);
        return NULL;
    }

    node = (struct buf_node *)sq_remfirst(queue);
    irqrestore(flags);

    return node;
}
Exemple #2
0
static void usbmsc_unbind(FAR struct usbdevclass_driver_s *driver, FAR struct usbdev_s *dev)
{
	FAR struct usbmsc_dev_s *priv;
	FAR struct usbmsc_req_s *reqcontainer;
	irqstate_t flags;
	int i;

	usbtrace(TRACE_CLASSUNBIND, 0);

#ifdef CONFIG_DEBUG
	if (!driver || !dev || !dev->ep0) {
		usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_UNBINDINVALIDARGS), 0);
		return;
	}
#endif

	/* Extract reference to private data */

	priv = ((FAR struct usbmsc_driver_s *)driver)->dev;

#ifdef CONFIG_DEBUG
	if (!priv) {
		usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_EP0NOTBOUND1), 0);
		return;
	}
#endif

	/* The worker thread should have already been stopped by the
	 * driver un-initialize logic.
	 */

	DEBUGASSERT(priv->thstate == USBMSC_STATE_TERMINATED || priv->thstate == USBMSC_STATE_NOTSTARTED);

	/* Make sure that we are not already unbound */

	if (priv != NULL) {
		/* Make sure that the endpoints have been unconfigured.  If
		 * we were terminated gracefully, then the configuration should
		 * already have been reset.  If not, then calling usbmsc_resetconfig
		 * should cause the endpoints to immediately terminate all
		 * transfers and return the requests to us (with result == -ESHUTDOWN)
		 */

		usbmsc_resetconfig(priv);
		up_mdelay(50);

		/* Free the pre-allocated control request */

		if (priv->ctrlreq != NULL) {
			usbmsc_freereq(dev->ep0, priv->ctrlreq);
			priv->ctrlreq = NULL;
		}

		/* Free pre-allocated read requests (which should all have
		 * been returned to the free list at this time -- we don't check)
		 */

		for (i = 0; i < CONFIG_USBMSC_NRDREQS; i++) {
			reqcontainer = &priv->rdreqs[i];
			if (reqcontainer->req) {
				usbmsc_freereq(priv->epbulkout, reqcontainer->req);
				reqcontainer->req = NULL;
			}
		}

		/* Free the bulk OUT endpoint */

		if (priv->epbulkout) {
			DEV_FREEEP(dev, priv->epbulkout);
			priv->epbulkout = NULL;
		}

		/* Free write requests that are not in use (which should be all
		 * of them
		 */

		flags = irqsave();
		while (!sq_empty(&priv->wrreqlist)) {
			reqcontainer = (struct usbmsc_req_s *)sq_remfirst(&priv->wrreqlist);
			if (reqcontainer->req != NULL) {
				usbmsc_freereq(priv->epbulkin, reqcontainer->req);
			}
		}

		/* Free the bulk IN endpoint */

		if (priv->epbulkin) {
			DEV_FREEEP(dev, priv->epbulkin);
			priv->epbulkin = NULL;
		}

		irqrestore(flags);
	}
}
Exemple #3
0
static inline int net_pollsetup(FAR struct socket *psock,
                                FAR struct pollfd *fds)
{
  FAR struct uip_conn *conn = psock->s_conn;
  FAR struct net_poll_s *info;
  FAR struct uip_callback_s *cb;
  uip_lock_t flags;
  int ret;

  /* Sanity check */

#ifdef CONFIG_DEBUG
  if (!conn || !fds)
    {
      return -EINVAL;
    }
#endif

  /* Allocate a container to hold the poll information */

  info = (FAR struct net_poll_s *)kmalloc(sizeof(struct net_poll_s));
  if (!info)
    {
      return -ENOMEM;
    }
  
  /* Some of the  following must be atomic */

  flags = uip_lock();

  /* Allocate a TCP/IP callback structure */

  cb = uip_tcpcallbackalloc(conn);
  if (!cb)
    {
      ret = -EBUSY;
      goto errout_with_lock;
    }

  /* Initialize the poll info container */

  info->psock  = psock;
  info->fds    = fds;
  info->cb     = cb;

  /* Initialize the callback structure.  Save the reference to the info
   * structure as callback private data so that it will be available during
   * callback processing.
   */

  cb->flags    = (UIP_NEWDATA|UIP_BACKLOG|UIP_POLL|UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT);
  cb->priv     = (FAR void *)info;
  cb->event    = poll_interrupt;

  /* Save the reference in the poll info structure as fds private as well
   * for use durring poll teardown as well.
   */

  fds->priv    = (FAR void *)info;

#ifdef CONFIG_NET_TCPBACKLOG
  /* Check for read data or backlogged connection availability now */

  if (!sq_empty(&conn->readahead) || uip_backlogavailable(conn))
#else
  /* Check for read data availability now */

  if (!sq_empty(&conn->readahead))
#endif
    {
      fds->revents |= (POLLOUT & fds->events);
    }

  /* Check for a loss of connection events */

  if (!_SS_ISCONNECTED(psock->s_flags))
    {
      fds->revents |= (POLLERR | POLLHUP);
    }

  /* Check if any requested events are already in effect */

  if (fds->revents != 0)
    {
      /* Yes.. then signal the poll logic */

      sem_post(fds->sem);
    }

  uip_unlock(flags);
  return OK;

errout_with_lock:
  kfree(info);
  uip_unlock(flags);
  return ret;
}
static uint16_t psock_send_interrupt(FAR struct net_driver_s *dev,
                                     FAR void *pvconn, FAR void *pvpriv,
                                     uint16_t flags)
{
    FAR struct tcp_conn_s *conn = (FAR struct tcp_conn_s *)pvconn;
    FAR struct socket *psock = (FAR struct socket *)pvpriv;

    nllvdbg("flags: %04x\n", flags);

    /* If this packet contains an acknowledgement, then update the count of
     * acknowledged bytes.
     */

    if ((flags & TCP_ACKDATA) != 0)
    {
        FAR struct tcp_wrbuffer_s *wrb;
        FAR sq_entry_t *entry;
        FAR sq_entry_t *next;
        uint32_t ackno;

        ackno = tcp_getsequence(TCPBUF->ackno);
        nllvdbg("ACK: ackno=%u flags=%04x\n", ackno, flags);

        /* Look at every write buffer in the unacked_q.  The unacked_q
         * holds write buffers that have been entirely sent, but which
         * have not yet been ACKed.
         */

        for (entry = sq_peek(&conn->unacked_q); entry; entry = next)
        {
            uint32_t lastseq;

            /* Check of some or all of this write buffer has been ACKed. */

            next = sq_next(entry);
            wrb = (FAR struct tcp_wrbuffer_s*)entry;

            /* If the ACKed sequence number is greater than the start
             * sequence number of the write buffer, then some or all of
             * the write buffer has been ACKed.
             */

            if (ackno > WRB_SEQNO(wrb))
            {
                /* Get the sequence number at the end of the data */

                lastseq = WRB_SEQNO(wrb) + WRB_PKTLEN(wrb);
                nllvdbg("ACK: wrb=%p seqno=%u lastseq=%u pktlen=%u ackno=%u\n",
                        wrb, WRB_SEQNO(wrb), lastseq, WRB_PKTLEN(wrb), ackno);

                /* Has the entire buffer been ACKed? */

                if (ackno >= lastseq)
                {
                    nllvdbg("ACK: wrb=%p Freeing write buffer\n", wrb);

                    /* Yes... Remove the write buffer from ACK waiting queue */

                    sq_rem(entry, &conn->unacked_q);

                    /* And return the write buffer to the pool of free buffers */

                    tcp_wrbuffer_release(wrb);
                }
                else
                {
                    unsigned int trimlen;

                    /* No, then just trim the ACKed bytes from the beginning
                     * of the write buffer.  This will free up some I/O buffers
                     * that can be reused while are still sending the last
                     * buffers in the chain.
                     */

                    trimlen = ackno - WRB_SEQNO(wrb);
                    if (trimlen > WRB_SENT(wrb))
                    {
                        /* More data has been ACKed then we have sent? */

                        trimlen = WRB_SENT(wrb);
                    }

                    nllvdbg("ACK: wrb=%p trim %u bytes\n", wrb, trimlen);

                    WRB_TRIM(wrb, trimlen);
                    WRB_SEQNO(wrb) = ackno;
                    WRB_SENT(wrb) -= trimlen;

                    /* Set the new sequence number for what remains */

                    nllvdbg("ACK: wrb=%p seqno=%u pktlen=%u\n",
                            wrb, WRB_SEQNO(wrb), WRB_PKTLEN(wrb));
                }
            }
        }

        /* A special case is the head of the write_q which may be partially
         * sent and so can still have un-ACKed bytes that could get ACKed
         * before the entire write buffer has even been sent.
         */

        wrb = (FAR struct tcp_wrbuffer_s*)sq_peek(&conn->write_q);
        if (wrb && WRB_SENT(wrb) > 0 && ackno > WRB_SEQNO(wrb))
        {
            uint32_t nacked;

            /* Number of bytes that were ACKed */

            nacked = ackno - WRB_SEQNO(wrb);
            if (nacked > WRB_SENT(wrb))
            {
                /* More data has been ACKed then we have sent? ASSERT? */

                nacked = WRB_SENT(wrb);
            }

            nllvdbg("ACK: wrb=%p seqno=%u nacked=%u sent=%u ackno=%u\n",
                    wrb, WRB_SEQNO(wrb), nacked, WRB_SENT(wrb), ackno);

            /* Trim the ACKed bytes from the beginning of the write buffer. */

            WRB_TRIM(wrb, nacked);
            WRB_SEQNO(wrb) = ackno;
            WRB_SENT(wrb) -= nacked;

            nllvdbg("ACK: wrb=%p seqno=%u pktlen=%u sent=%u\n",
                    wrb, WRB_SEQNO(wrb), WRB_PKTLEN(wrb), WRB_SENT(wrb));
        }
    }

    /* Check for a loss of connection */

    else if ((flags & (TCP_CLOSE | TCP_ABORT | TCP_TIMEDOUT)) != 0)
    {
        nllvdbg("Lost connection: %04x\n", flags);

        /* Report not connected */

        net_lostconnection(psock, flags);

        /* Free write buffers and terminate polling */

        psock_lost_connection(psock, conn);
        return flags;
    }

    /* Check if we are being asked to retransmit data */

    else if ((flags & TCP_REXMIT) != 0)
    {
        FAR struct tcp_wrbuffer_s *wrb;
        FAR sq_entry_t *entry;

        nllvdbg("REXMIT: %04x\n", flags);

        /* If there is a partially sent write buffer at the head of the
         * write_q?  Has anything been sent from that write buffer?
         */

        wrb = (FAR struct tcp_wrbuffer_s *)sq_peek(&conn->write_q);
        nllvdbg("REXMIT: wrb=%p sent=%u\n", wrb, wrb ? WRB_SENT(wrb) : 0);

        if (wrb != NULL && WRB_SENT(wrb) > 0)
        {
            FAR struct tcp_wrbuffer_s *tmp;
            uint16_t sent;

            /* Yes.. Reset the number of bytes sent sent from the write buffer */

            sent = WRB_SENT(wrb);
            if (conn->unacked > sent)
            {
                conn->unacked -= sent;
            }
            else
            {
                conn->unacked = 0;
            }

            if (conn->sent > sent)
            {
                conn->sent -= sent;
            }
            else
            {
                conn->sent = 0;
            }

            WRB_SENT(wrb) = 0;
            nllvdbg("REXMIT: wrb=%p sent=%u, conn unacked=%d sent=%d\n",
                    wrb, WRB_SENT(wrb), conn->unacked, conn->sent);

            /* Increment the retransmit count on this write buffer. */

            if (++WRB_NRTX(wrb) >= TCP_MAXRTX)
            {
                nlldbg("Expiring wrb=%p nrtx=%u\n", wrb, WRB_NRTX(wrb));

                /* The maximum retry count as been exhausted. Remove the write
                 * buffer at the head of the queue.
                 */

                tmp = (FAR struct tcp_wrbuffer_s *)sq_remfirst(&conn->write_q);
                DEBUGASSERT(tmp == wrb);
                UNUSED(tmp);

                /* And return the write buffer to the free list */

                tcp_wrbuffer_release(wrb);

                /* NOTE expired is different from un-ACKed, it is designed to
                 * represent the number of segments that have been sent,
                 * retransmitted, and un-ACKed, if expired is not zero, the
                 * connection will be closed.
                 *
                 * field expired can only be updated at TCP_ESTABLISHED state
                 */

                conn->expired++;
            }
        }

        /* Move all segments that have been sent but not ACKed to the write
         * queue again note, the un-ACKed segments are put at the head of the
         * write_q so they can be resent as soon as possible.
         */

        while ((entry = sq_remlast(&conn->unacked_q)) != NULL)
        {
            wrb = (FAR struct tcp_wrbuffer_s*)entry;
            uint16_t sent;

            /* Reset the number of bytes sent sent from the write buffer */

            sent = WRB_SENT(wrb);
            if (conn->unacked > sent)
            {
                conn->unacked -= sent;
            }
            else
            {
                conn->unacked = 0;
            }

            if (conn->sent > sent)
            {
                conn->sent -= sent;
            }
            else
            {
                conn->sent = 0;
            }

            WRB_SENT(wrb) = 0;
            nllvdbg("REXMIT: wrb=%p sent=%u, conn unacked=%d sent=%d\n",
                    wrb, WRB_SENT(wrb), conn->unacked, conn->sent);

            /* Free any write buffers that have exceed the retry count */

            if (++WRB_NRTX(wrb) >= TCP_MAXRTX)
            {
                nlldbg("Expiring wrb=%p nrtx=%u\n", wrb, WRB_NRTX(wrb));

                /* Return the write buffer to the free list */

                tcp_wrbuffer_release(wrb);

                /* NOTE expired is different from un-ACKed, it is designed to
                 * represent the number of segments that have been sent,
                 * retransmitted, and un-ACKed, if expired is not zero, the
                 * connection will be closed.
                 *
                 * field expired can only be updated at TCP_ESTABLISHED state
                 */

                conn->expired++;
                continue;
            }
            else
            {
                /* Insert the write buffer into the write_q (in sequence
                 * number order).  The retransmission will occur below
                 * when the write buffer with the lowest sequenc number
                 * is pulled from the write_q again.
                 */

                nllvdbg("REXMIT: Moving wrb=%p nrtx=%u\n", wrb, WRB_NRTX(wrb));

                psock_insert_segment(wrb, &conn->write_q);
            }
        }
    }

    /* Check if the outgoing packet is available (it may have been claimed
     * by a sendto interrupt serving a different thread).
     */

    if (dev->d_sndlen > 0)
    {
        /* Another thread has beat us sending data, wait for the next poll */

        return flags;
    }

    /* We get here if (1) not all of the data has been ACKed, (2) we have been
     * asked to retransmit data, (3) the connection is still healthy, and (4)
     * the outgoing packet is available for our use.  In this case, we are
     * now free to send more data to receiver -- UNLESS the buffer contains
     * unprocessed incoming data.  In that event, we will have to wait for the
     * next polling cycle.
     */

    if ((conn->tcpstateflags & TCP_ESTABLISHED) &&
            (flags & (TCP_POLL | TCP_REXMIT)) &&
            !(sq_empty(&conn->write_q)))
    {
        /* Check if the destination IP address is in the ARP table.  If not,
         * then the send won't actually make it out... it will be replaced with
         * an ARP request.
         *
         * NOTE 1: This could be an expensive check if there are a lot of
         * entries in the ARP table.
         *
         * NOTE 2: If we are actually harvesting IP addresses on incoming IP
         * packets, then this check should not be necessary; the MAC mapping
         * should already be in the ARP table in many cases.
         *
         * NOTE 3: If CONFIG_NET_ARP_SEND then we can be assured that the IP
         * address mapping is already in the ARP table.
         */

#if defined(CONFIG_NET_ETHERNET) && !defined(CONFIG_NET_ARP_IPIN) && \
    !defined(CONFIG_NET_ARP_SEND)
        if (arp_find(conn->ripaddr) != NULL)
#endif
        {
            FAR struct tcp_wrbuffer_s *wrb;
            size_t sndlen;

            /* Peek at the head of the write queue (but don't remove anything
             * from the write queue yet).  We know from the above test that
             * the write_q is not empty.
             */

            wrb = (FAR struct tcp_wrbuffer_s *)sq_peek(&conn->write_q);
            DEBUGASSERT(wrb);

            /* Get the amount of data that we can send in the next packet.
             * We will send either the remaining data in the buffer I/O
             * buffer chain, or as much as will fit given the MSS and current
             * window size.
             */

            sndlen = WRB_PKTLEN(wrb) - WRB_SENT(wrb);
            if (sndlen > tcp_mss(conn))
            {
                sndlen = tcp_mss(conn);
            }

            if (sndlen > conn->winsize)
            {
                sndlen = conn->winsize;
            }

            nllvdbg("SEND: wrb=%p pktlen=%u sent=%u sndlen=%u\n",
                    wrb, WRB_PKTLEN(wrb), WRB_SENT(wrb), sndlen);

            /* Set the sequence number for this segment.  If we are
             * retransmitting, then the sequence number will already
             * be set for this write buffer.
             */

            if (WRB_SEQNO(wrb) == (unsigned)-1)
            {
                WRB_SEQNO(wrb) = conn->isn + conn->sent;
            }

            /* The TCP stack updates sndseq on receipt of ACK *before*
             * this function is called. In that case sndseq will point
             * to the next unacknowledged byte (which might have already
             * been sent). We will overwrite the value of sndseq here
             * before the packet is sent.
             */

            tcp_setsequence(conn->sndseq, WRB_SEQNO(wrb) + WRB_SENT(wrb));

            /* Then set-up to send that amount of data with the offset
             * corresponding to the amount of data already sent. (this
             * won't actually happen until the polling cycle completes).
             */

            devif_iob_send(dev, WRB_IOB(wrb), sndlen, WRB_SENT(wrb));

            /* Remember how much data we send out now so that we know
             * when everything has been acknowledged.  Just increment
             * the amount of data sent. This will be needed in sequence
             * number calculations.
             */

            conn->unacked += sndlen;
            conn->sent    += sndlen;

            nllvdbg("SEND: wrb=%p nrtx=%u unacked=%u sent=%u\n",
                    wrb, WRB_NRTX(wrb), conn->unacked, conn->sent);

            /* Increment the count of bytes sent from this write buffer */

            WRB_SENT(wrb) += sndlen;

            nllvdbg("SEND: wrb=%p sent=%u pktlen=%u\n",
                    wrb, WRB_SENT(wrb), WRB_PKTLEN(wrb));

            /* Remove the write buffer from the write queue if the
             * last of the data has been sent from the buffer.
             */

            DEBUGASSERT(WRB_SENT(wrb) <= WRB_PKTLEN(wrb));
            if (WRB_SENT(wrb) >= WRB_PKTLEN(wrb))
            {
                FAR struct tcp_wrbuffer_s *tmp;

                nllvdbg("SEND: wrb=%p Move to unacked_q\n", wrb);

                tmp = (FAR struct tcp_wrbuffer_s *)sq_remfirst(&conn->write_q);
                DEBUGASSERT(tmp == wrb);
                UNUSED(tmp);

                /* Put the I/O buffer chain in the un-acked queue; the
                 * segment is waiting for ACK again
                 */

                psock_insert_segment(wrb, &conn->unacked_q);
            }

            /* Only one data can be sent by low level driver at once,
             * tell the caller stop polling the other connection.
             */

            flags &= ~TCP_POLL;
        }
    }

    /* Continue waiting */

    return flags;
}
Exemple #5
0
static inline int net_pollsetup(FAR struct socket *psock, struct pollfd *fds)
{
  FAR struct uip_conn *conn = psock->s_conn;
  FAR struct uip_callback_s *cb;
  uip_lock_t flags;
  int ret;

  /* Sanity check */

#ifdef CONFIG_DEBUG
  if (!conn || !fds)
    {
      return -EINVAL;
    }
#endif

  /* Some of the  following must be atomic */

  flags = uip_lock();

  /* Allocate a TCP/IP callback structure */

  cb = uip_tcpcallbackalloc(conn);
  if (!cb)
    {
      ret = -EBUSY;
      goto errout_with_irq;
    }

  /* Initialize the callbcack structure */

  cb->flags    = UIP_NEWDATA|UIP_BACKLOG|UIP_POLL|UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT;
  cb->priv     = (FAR void *)fds;
  cb->event    = poll_interrupt;

  /* Save the nps reference in the poll structure for use at teardown as well */

  fds->priv    = (FAR void *)cb;

#ifdef CONFIG_NET_TCPBACKLOG
  /* Check for read data or backlogged connection availability now */

  if (!sq_empty(&conn->readahead) || uip_backlogavailable(conn))
#else
  /* Check for read data availability now */

  if (!sq_empty(&conn->readahead))
#endif
    {
      fds->revents = fds->events & POLLIN;
      if (fds->revents != 0)
        {
          /* If data is available now, the signal the poll logic */

          sem_post(fds->sem);
        }
    }
  uip_unlock(flags);
  return OK;

errout_with_irq:
  uip_unlock(flags);
  return ret;
}
Exemple #6
0
bool uip_backlogavailable(FAR struct uip_conn *conn)
{
  return (conn && conn->backlog && !sq_empty(&conn->backlog->bl_pending));
}
static uint16_t send_interrupt(FAR struct uip_driver_s *dev, FAR void *pvconn,
                               FAR void *pvpriv, uint16_t flags)
{
  FAR struct uip_conn *conn = (FAR struct uip_conn*)pvconn;
  FAR struct socket *psock = (FAR struct socket *)pvpriv;

  nllvdbg("flags: %04x\n", flags);

  /* If this packet contains an acknowledgement, then update the count of
   * acknowledged bytes.
   */

  if ((flags & UIP_ACKDATA) != 0)
    {
      FAR sq_entry_t *entry, *next;
      FAR struct uip_wrbuffer_s *segment;
      uint32_t ackno;

      ackno = uip_tcpgetsequence(TCPBUF->ackno);
      for (entry = sq_peek(&conn->unacked_q); entry; entry = next)
        {
          next    = sq_next(entry);
          segment = (FAR struct uip_wrbuffer_s*)entry;

          if (segment->wb_seqno < ackno)
            {
              nllvdbg("ACK: acked=%d buflen=%d ackno=%d\n",
                      segment->wb_seqno, segment->wb_nbytes, ackno);

              /* Segment was ACKed. Remove from ACK waiting queue */

              sq_rem(entry, &conn->unacked_q);

              /* Return the write buffer to the pool of free buffers */

              uip_tcpwrbuffer_release(segment);
            }
        }
    }

  /* Check for a loss of connection */

  else if ((flags & (UIP_CLOSE | UIP_ABORT | UIP_TIMEDOUT)) != 0)
    {
      /* Report not connected */

       nllvdbg("Lost connection\n");
       net_lostconnection(psock, flags);
       goto end_wait;
     }

   /* Check if we are being asked to retransmit data */

   else if ((flags & UIP_REXMIT) != 0)
    {
      sq_entry_t *entry;

      /* Put all segments that have been sent but not ACKed to write queue
       * again note, the un-ACKed segment is put at the first of the write_q,
       * so it can be sent as soon as possible.
       */

      while ((entry = sq_remlast(&conn->unacked_q)))
        {
          struct uip_wrbuffer_s *segment = (struct uip_wrbuffer_s*)entry;

          if (segment->wb_nrtx >= UIP_MAXRTX)
            {
              //conn->unacked -= segment->wb_nbytes;

              /* Return the write buffer */

              uip_tcpwrbuffer_release(segment);

              /* NOTE expired is different from un-ACKed, it is designed to
               * represent the number of segments that have been sent,
               * retransmitted, and un-ACKed, if expired is not zero, the
               * connection will be closed.
               *
               * field expired can only be updated at UIP_ESTABLISHED state
               */

              conn->expired++;
              continue;
            }

          send_insert_seqment(segment, &conn->write_q);
        }
    }

  /* Check if the outgoing packet is available (it may have been claimed
   * by a sendto interrupt serving a different thread).
   */

  if (dev->d_sndlen > 0)
    {
      /* Another thread has beat us sending data, wait for the next poll */

      return flags;
    }

  /* We get here if (1) not all of the data has been ACKed, (2) we have been
   * asked to retransmit data, (3) the connection is still healthy, and (4)
   * the outgoing packet is available for our use.  In this case, we are
   * now free to send more data to receiver -- UNLESS the buffer contains
   * unprocesed incoming data.  In that event, we will have to wait for the
   * next polling cycle.
   */

  if ((conn->tcpstateflags & UIP_ESTABLISHED) &&
      (flags & (UIP_POLL | UIP_REXMIT)) &&
      !(sq_empty(&conn->write_q)))
    {
      /* Check if the destination IP address is in the ARP table.  If not,
       * then the send won't actually make it out... it will be replaced with
       * an ARP request.
       *
       * NOTE 1: This could be an expensive check if there are a lot of
       * entries in the ARP table.
       *
       * NOTE 2: If we are actually harvesting IP addresses on incomming IP
       * packets, then this check should not be necessary; the MAC mapping
       * should already be in the ARP table.
       */

#if defined(CONFIG_NET_ETHERNET) && !defined(CONFIG_NET_ARP_IPIN)
      if (uip_arp_find(conn->ripaddr) != NULL)
#endif
        {
          FAR struct uip_wrbuffer_s *segment;
          FAR void *sndbuf;
          size_t sndlen;

          /* Get the amount of data that we can send in the next packet */

          segment = (FAR struct uip_wrbuffer_s *)sq_remfirst(&conn->write_q);
          if (segment)
            {
              sndbuf = segment->wb_buffer;
              sndlen = segment->wb_nbytes;

              DEBUGASSERT(sndlen <= uip_mss(conn));

              /* REVISIT:  There should be a check here to assure that we do
               * not excced the window (conn->winsize).
               */

              /* Set the sequence number for this segment.  NOTE: uIP
               * updates sndseq on receipt of ACK *before* this function
               * is called. In that case sndseq will point to the next
               * unacknowledged byte (which might have already been
               * sent). We will overwrite the value of sndseq here
               * before the packet is sent.
               */

              if (segment->wb_nrtx == 0 && segment->wb_seqno == (unsigned)-1)
                {
                  segment->wb_seqno = conn->isn + conn->sent;
                }

              uip_tcpsetsequence(conn->sndseq, segment->wb_seqno);

              /* Then set-up to send that amount of data. (this won't
               * actually happen until the polling cycle completes).
               */

              uip_send(dev, sndbuf, sndlen);

              /* Remember how much data we send out now so that we know
               * when everything has been acknowledged.  Just increment
               * the amount of data sent. This will be needed in
               * sequence* number calculations and we know that this is
               * not a re-transmission. Re-transmissions do not go through
               * this path.
               */

              if (segment->wb_nrtx == 0)
                {
                  conn->unacked += sndlen;
                  conn->sent    += sndlen;
                }

              /* Increment the retransmission counter before expiration.
               * NOTE we will not calculate the retransmission timer
               * (RTT) to save cpu cycles, each send_insert_seqment
               * segment will be retransmitted UIP_MAXRTX times in halt-
               * second interval before expiration.
               */

              segment->wb_nrtx++;

              /* The segment is waiting for ACK again */

              send_insert_seqment(segment, &conn->unacked_q);

              /* Only one data can be sent by low level driver at once,
               * tell the caller stop polling the other connection.
               */

              flags &= ~UIP_POLL;
            }
        }
    }

  /* Continue waiting */

  return flags;

end_wait:

  /* Do not allow any further callbacks */

  psock->s_sndcb->flags = 0;
  psock->s_sndcb->event = NULL;

  return flags;
}
Exemple #8
0
static uint16_t netclose_interrupt(FAR struct net_driver_s *dev,
                                   FAR void *pvconn, FAR void *pvpriv,
                                   uint16_t flags)
{
#ifdef CONFIG_NET_SOLINGER
  FAR struct tcp_close_s *pstate = (FAR struct tcp_close_s *)pvpriv;
#endif
  FAR struct tcp_conn_s *conn = (FAR struct tcp_conn_s *)pvconn;

  DEBUGASSERT(conn != NULL);

  nllvdbg("conn: %p flags: %04x\n", conn, flags);

  /* TCP_DISCONN_EVENTS:
   *   TCP_CLOSE:    The remote host has closed the connection
   *   TCP_ABORT:    The remote host has aborted the connection
   *   TCP_TIMEDOUT: The remote did not respond, the connection timed out
   *   NETDEV_DOWN:  The network device went down
   */

  if ((flags & TCP_DISCONN_EVENTS) != 0)
    {
      /* The disconnection is complete */

#ifdef CONFIG_NET_SOLINGER
      /* pstate non-NULL means that we are performing a LINGERing close. */

      if (pstate)
        {
          /* Wake up the waiting thread with a successful result */

          pstate->cl_result = OK;
          goto end_wait;
        }

      /* Otherwise, nothing is waiting on the close event and we can perform
       * the completion actions here.
       */

      else
#endif
        {
          /* Free connection resources */

          tcp_free(conn);

          /* Stop further callbacks */

          flags = 0;
        }
    }

#ifdef CONFIG_NET_SOLINGER
  /* Check for a timeout. */

  else if (pstate && close_timeout(pstate))
    {
      /* Yes.. Wake up the waiting thread and report the timeout */

      nlldbg("CLOSE timeout\n");
      pstate->cl_result = -ETIMEDOUT;
      goto end_wait;
    }

#endif /* CONFIG_NET_SOLINGER */

#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
  /* Check if all outstanding bytes have been ACKed */

  else if (conn->unacked != 0 || !sq_empty(&conn->write_q))
    {
      /* No... we are still waiting for ACKs.  Drop any received data, but
       * do not yet report TCP_CLOSE in the response.
       */

      dev->d_len = 0;
      flags = (flags & ~TCP_NEWDATA);
    }

#endif /* CONFIG_NET_TCP_WRITE_BUFFERS */

  else
    {
      /* Drop data received in this state and make sure that TCP_CLOSE
       * is set in the response
       */

      dev->d_len = 0;
      flags = (flags & ~TCP_NEWDATA) | TCP_CLOSE;
    }

  return flags;

#ifdef CONFIG_NET_SOLINGER
end_wait:
  pstate->cl_cb->flags = 0;
  pstate->cl_cb->priv  = NULL;
  pstate->cl_cb->event = NULL;
  sem_post(&pstate->cl_sem);

  nllvdbg("Resuming\n");
  return 0;
#endif
}