Beispiel #1
0
static uint16_t ack_interrupt(FAR struct net_driver_s *dev, FAR void *pvconn,
                              FAR void *pvpriv, uint16_t flags)
{
  FAR struct sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;

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

  if ((flags & TCP_ACKDATA) != 0)
    {
#ifdef CONFIG_NET_SOCKOPTS
      /* Update the timeout */

      pstate->snd_time = clock_systimer();
#endif

      /* The current acknowledgement number number is the (relative) offset
       * of the of the next byte needed by the receiver.  The snd_isn is the
       * offset of the first byte to send to the receiver.  The difference
       * is the number of bytes to be acknowledged.
       */

      pstate->snd_acked = tcp_getsequence(TCPBUF->ackno) - pstate->snd_isn;
      nllvdbg("ACK: acked=%d sent=%d flen=%d\n",
             pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);

      dev->d_sndlen = 0;

      flags &= ~TCP_ACKDATA;
    }
  else if ((flags & TCP_REXMIT) != 0)
    {
      nlldbg("REXMIT\n");

      /* Yes.. in this case, reset the number of bytes that have been sent
       * to the number of bytes that have been ACKed.
       */

      pstate->snd_sent = pstate->snd_acked;
    }

  /* Check for a loss of connection */

  else if ((flags & (TCP_CLOSE | TCP_ABORT | TCP_TIMEDOUT)) != 0)
    {
      /* Report not connected */

      nlldbg("Lost connection\n");

      net_lostconnection(pstate->snd_sock, flags);
      pstate->snd_sent = -ENOTCONN;
    }

  /* Wake up the waiting thread */

  sem_post(&pstate->snd_sem);

  return flags;
}
ssize_t psock_tcp_send(FAR struct socket *psock,
                       FAR const void *buf, size_t len)
{
  FAR struct tcp_conn_s *conn = (FAR struct tcp_conn_s *)psock->s_conn;
  struct send_s state;
  net_lock_t save;
  int err;
  int ret = OK;

  /* Verify that the sockfd corresponds to valid, allocated socket */

  if (!psock || psock->s_crefs <= 0)
    {
      ndbg("ERROR: Invalid socket\n");
      err = EBADF;
      goto errout;
    }

  /* If this is an un-connected socket, then return ENOTCONN */

  if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
    {
      ndbg("ERROR: Not connected\n");
      err = ENOTCONN;
      goto errout;
    }

  /* Make sure that we have the IP address mapping */

  conn = (FAR struct tcp_conn_s *)psock->s_conn;
  DEBUGASSERT(conn);

#if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR)
#ifdef CONFIG_NET_ARP_SEND
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
  if (psock->s_domain == PF_INET)
#endif
    {
      /* Make sure that the IP address mapping is in the ARP table */

      ret = arp_send(conn->u.ipv4.raddr);
    }
#endif /* CONFIG_NET_ARP_SEND */


#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
#ifdef CONFIG_NET_ARP_SEND
  else
#endif
    {
      /* Make sure that the IP address mapping is in the Neighbor Table */

      ret = icmpv6_neighbor(conn->u.ipv6.raddr);
    }
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */

  /* Did we successfully get the address mapping? */

  if (ret < 0)
    {
      ndbg("ERROR: Not reachable\n");
      err = ENETUNREACH;
      goto errout;
    }
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */

  /* Set the socket state to sending */

  psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND);

  /* Perform the TCP send operation */

  /* Initialize the state structure.  This is done with interrupts
   * disabled because we don't want anything to happen until we
   * are ready.
   */

  save                = net_lock();
  memset(&state, 0, sizeof(struct send_s));
  (void)sem_init(&state.snd_sem, 0, 0);    /* Doesn't really fail */
  state.snd_sock      = psock;             /* Socket descriptor to use */
  state.snd_buflen    = len;               /* Number of bytes to send */
  state.snd_buffer    = buf;               /* Buffer to send from */

  if (len > 0)
    {
      /* Allocate resources to receive a callback */

      state.snd_cb = tcp_callback_alloc(conn);
      if (state.snd_cb)
        {
          /* Get the initial sequence number that will be used */

          state.snd_isn         = tcp_getsequence(conn->sndseq);

          /* There is no outstanding, unacknowledged data after this
           * initial sequence number.
           */

          conn->unacked         = 0;

          /* Set the initial time for calculating timeouts */

#ifdef CONFIG_NET_SOCKOPTS
          state.snd_time        = clock_systimer();
#endif
          /* Set up the callback in the connection */

          state.snd_cb->flags   = (TCP_ACKDATA | TCP_REXMIT | TCP_POLL |
                                   TCP_DISCONN_EVENTS);
          state.snd_cb->priv    = (FAR void *)&state;
          state.snd_cb->event   = tcpsend_interrupt;

          /* Notify the device driver of the availability of TX data */

          send_txnotify(psock, conn);

          /* Wait for the send to complete or an error to occur:  NOTES: (1)
           * net_lockedwait will also terminate if a signal is received, (2) interrupts
           * may be disabled!  They will be re-enabled while the task sleeps and
           * automatically re-enabled when the task restarts.
           */

          ret = net_lockedwait(&state.snd_sem);

          /* Make sure that no further interrupts are processed */

          tcp_callback_free(conn, state.snd_cb);
        }
    }

  sem_destroy(&state.snd_sem);
  net_unlock(save);

  /* Set the socket state to idle */

  psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);

  /* Check for a errors.  Errors are signalled by negative errno values
   * for the send length
   */

  if (state.snd_sent < 0)
    {
      err = state.snd_sent;
      goto errout;
    }

  /* If net_lockedwait failed, then we were probably reawakened by a signal. In
   * this case, net_lockedwait will have set errno appropriately.
   */

  if (ret < 0)
    {
      err = -ret;
      goto errout;
    }

  /* Return the number of bytes actually sent */

  return state.snd_sent;

errout:
  set_errno(err);
  return ERROR;
}
static uint16_t tcpsend_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 send_s *pstate = (FAR struct send_s *)pvpriv;

#ifdef CONFIG_NETDEV_MULTINIC
  /* The TCP socket is connected and, hence, should be bound to a device.
   * Make sure that the polling device is the one that we are bound to.
   */

  DEBUGASSERT(conn->dev != NULL);
  if (dev != conn->dev)
    {
      return flags;
    }
#endif

  nllvdbg("flags: %04x acked: %d sent: %d\n",
          flags, pstate->snd_acked, pstate->snd_sent);

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

  if ((flags & TCP_ACKDATA) != 0)
    {
      FAR struct tcp_hdr_s *tcp;

      /* Update the timeout */

#ifdef CONFIG_NET_SOCKOPTS
      pstate->snd_time = clock_systimer();
#endif

      /* Get the offset address of the TCP header */

#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
      if (conn->domain == PF_INET)
#endif
        {
          DEBUGASSERT(IFF_IS_IPv4(dev->d_flags));
          tcp = TCPIPv4BUF;
        }
#endif /* CONFIG_NET_IPv4 */

#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
      else
#endif
        {
          DEBUGASSERT(IFF_IS_IPv6(dev->d_flags));
          tcp = TCPIPv6BUF;
        }
#endif /* CONFIG_NET_IPv6 */

      /* The current acknowledgement number number is the (relative) offset
       * of the of the next byte needed by the receiver.  The snd_isn is the
       * offset of the first byte to send to the receiver.  The difference
       * is the number of bytes to be acknowledged.
       */

      pstate->snd_acked = tcp_getsequence(tcp->ackno) - pstate->snd_isn;
      nllvdbg("ACK: acked=%d sent=%d buflen=%d\n",
              pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen);

      /* Have all of the bytes in the buffer been sent and acknowledged? */

      if (pstate->snd_acked >= pstate->snd_buflen)
        {
          /* Yes.  Then pstate->snd_buflen should hold the number of bytes
           * actually sent.
           */

          goto end_wait;
        }

      /* No.. fall through to send more data if necessary */
    }

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

  else if ((flags & TCP_REXMIT) != 0)
    {
      /* Yes.. in this case, reset the number of bytes that have been sent
       * to the number of bytes that have been ACKed.
       */

      pstate->snd_sent = pstate->snd_acked;

#if defined(CONFIG_NET_TCP_SPLIT)
      /* Reset the even/odd indicator to even since we need to
       * retransmit.
       */

      pstate->snd_odd = false;
#endif

      /* Fall through to re-send data from the last that was ACKed */
    }

  /* Check for a loss of connection */

  else if ((flags & TCP_DISCONN_EVENTS) != 0)
    {
      /* Report not connected */

      nllvdbg("Lost connection\n");

      net_lostconnection(pstate->snd_sock, flags);
      pstate->snd_sent = -ENOTCONN;
      goto end_wait;
    }

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

#if 0 /* We can't really support multiple senders on the same TCP socket */
  else if (dev->d_sndlen > 0)
    {
      /* Another thread has beat us sending data, wait for the next poll */

      return flags;
    }
#endif

  /* 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 ((flags & TCP_NEWDATA) == 0 && pstate->snd_sent < pstate->snd_buflen)
    {
      uint32_t seqno;

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

      uint32_t sndlen = pstate->snd_buflen - pstate->snd_sent;

#if defined(CONFIG_NET_TCP_SPLIT)

      /* RFC 1122 states that a host may delay ACKing for up to 500ms but
       * must respond to every second  segment).  This logic here will trick
       * the RFC 1122 recipient into responding sooner.  This logic will be
       * activated if:
       *
       *   1. An even number of packets has been send (where zero is an even
       *      number),
       *   2. There is more data be sent (more than or equal to
       *      CONFIG_NET_TCP_SPLIT_SIZE), but
       *   3. Not enough data for two packets.
       *
       * Then we will split the remaining, single packet into two partial
       * packets.  This will stimulate the RFC 1122 peer to ACK sooner.
       *
       * Don't try to split very small packets (less than CONFIG_NET_TCP_SPLIT_SIZE).
       * Only the first even packet and the last odd packets could have
       * sndlen less than CONFIG_NET_TCP_SPLIT_SIZE.  The value of sndlen on
       * the last even packet is guaranteed to be at least MSS/2 by the
       * logic below.
       */

      if (sndlen >= CONFIG_NET_TCP_SPLIT_SIZE)
        {
          /* sndlen is the number of bytes remaining to be sent.
           * conn->mss will provide the number of bytes that can sent
           * in one packet.  The difference, then, is the number of bytes
           * that would be sent in the next packet after this one.
           */

          int32_t next_sndlen = sndlen - conn->mss;

          /*  Is this the even packet in the packet pair transaction? */

          if (!pstate->snd_odd)
            {
              /* next_sndlen <= 0 means that the entire remaining data
               * could fit into this single packet.  This is condition
               * in which we must do the split.
               */

              if (next_sndlen <= 0)
                {
                  /* Split so that there will be an odd packet.  Here
                   * we know that 0 < sndlen <= MSS
                   */

                  sndlen = (sndlen / 2) + 1;
                }
            }

          /* No... this is the odd packet in the packet pair transaction */

          else
            {
              /* Will there be another (even) packet afer this one?
               * (next_sndlen > 0)  Will the split condition occur on that
               * next, even packet? ((next_sndlen - conn->mss) < 0) If
               * so, then perform the split now to avoid the case where the
               * byte count is less than CONFIG_NET_TCP_SPLIT_SIZE on the
               * next pair.
               */

              if (next_sndlen > 0 && (next_sndlen - conn->mss) < 0)
                {
                  /* Here, we know that sndlen must be MSS < sndlen <= 2*MSS
                   * and so (sndlen / 2) is <= MSS.
                   */

                  sndlen /= 2;
                }
            }
        }

      /* Toggle the even/odd indicator */

      pstate->snd_odd ^= true;

#endif /* CONFIG_NET_TCP_SPLIT */

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

      /* Check if we have "space" in the window */

      if ((pstate->snd_sent - pstate->snd_acked + sndlen) < conn->winsize)
        {
          /* Set the sequence number for this packet.  NOTE:  The network 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.
           */

          seqno = pstate->snd_sent + pstate->snd_isn;
          nllvdbg("SEND: sndseq %08x->%08x\n", conn->sndseq, seqno);
          tcp_setsequence(conn->sndseq, seqno);

#ifdef NEED_IPDOMAIN_SUPPORT
          /* If both IPv4 and IPv6 support are enabled, then we will need to
           * select which one to use when generating the outgoing packet.
           * If only one domain is selected, then the setup is already in
           * place and we need do nothing.
           */

          tcpsend_ipselect(dev, pstate);
#endif
          /* Then set-up to send that amount of data. (this won't actually
           * happen until the polling cycle completes).
           */

          devif_send(dev, &pstate->snd_buffer[pstate->snd_sent], sndlen);

          /* Check if the destination IP address is in the ARP  or Neighbor
           * table.  If not, then the send won't actually make it out... it
           * will be replaced with an ARP request or Neighbor Solicitation.
           */

          if (pstate->snd_sent != 0 || psock_send_addrchck(conn))
            {
              /* Update the amount of data sent (but not necessarily ACKed) */

              pstate->snd_sent += sndlen;
              nllvdbg("SEND: acked=%d sent=%d buflen=%d\n",
                      pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen);

            }
        }
    }

#ifdef CONFIG_NET_SOCKOPTS
  /* All data has been sent and we are just waiting for ACK or re-transmit
   * indications to complete the send.  Check for a timeout.
   */

  if (send_timeout(pstate))
    {
      /* Yes.. report the timeout */

      nlldbg("SEND timeout\n");
      pstate->snd_sent = -ETIMEDOUT;
      goto end_wait;
    }
#endif /* CONFIG_NET_SOCKOPTS */

  /* Continue waiting */

  return flags;

end_wait:
  /* Do not allow any further callbacks */

  pstate->snd_cb->flags   = 0;
  pstate->snd_cb->priv    = NULL;
  pstate->snd_cb->event   = NULL;

  /* There are no outstanding, unacknowledged bytes */

  conn->unacked           = 0;

  /* Wake up the waiting thread */

  sem_post(&pstate->snd_sem);
  return flags;
}
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;
}
Beispiel #5
0
ssize_t net_sendfile(int outfd, struct file *infile, off_t *offset,
                     size_t count)
{
  FAR struct socket *psock = sockfd_socket(outfd);
  FAR struct tcp_conn_s *conn;
  struct sendfile_s state;
  net_lock_t save;
  int err;

  /* Verify that the sockfd corresponds to valid, allocated socket */

  if (!psock || psock->s_crefs <= 0)
    {
      ndbg("ERROR: Invalid socket\n");
      err = EBADF;
      goto errout;
    }

  /* If this is an un-connected socket, then return ENOTCONN */

  if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
    {
      ndbg("ERROR: Not connected\n");
      err = ENOTCONN;
      goto errout;
    }

  /* Make sure that we have the IP address mapping */

  conn = (FAR struct tcp_conn_s *)psock->s_conn;
  DEBUGASSERT(conn);

#if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR)
#ifdef CONFIG_NET_ARP_SEND
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
  if (psock->s_domain == PF_INET)
#endif
    {
      /* Make sure that the IP address mapping is in the ARP table */

      ret = arp_send(conn->u.ipv4.raddr);
    }
#endif /* CONFIG_NET_ARP_SEND */


#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
#ifdef CONFIG_NET_ARP_SEND
  else
#endif
    {
      /* Make sure that the IP address mapping is in the Neighbor Table */

      ret = icmpv6_neighbor(conn->u.ipv6.raddr);
    }
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */

  /* Did we successfully get the address mapping? */

  if (ret < 0)
    {
      ndbg("ERROR: Not reachable\n");
      err = ENETUNREACH;
      goto errout;
    }
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */

  /* Set the socket state to sending */

  psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND);

  /* Initialize the state structure.  This is done with interrupts
   * disabled because we don't want anything to happen until we
   * are ready.
   */

  save  = net_lock();

  memset(&state, 0, sizeof(struct sendfile_s));
  sem_init(&state. snd_sem, 0, 0);          /* Doesn't really fail */
  state.snd_sock    = psock;                /* Socket descriptor to use */
  state.snd_foffset = offset ? *offset : 0; /* Input file offset */
  state.snd_flen    = count;                /* Number of bytes to send */
  state.snd_file    = infile;               /* File to read from */

  /* Allocate resources to receive a callback */

  state.snd_datacb = tcp_callback_alloc(conn);

  if (state.snd_datacb == NULL)
    {
      nlldbg("Failed to allocate data callback\n");
      err = ENOMEM;
      goto errout_locked;
    }

  state.snd_ackcb = tcp_callback_alloc(conn);

  if (state.snd_ackcb == NULL)
    {
      nlldbg("Failed to allocate ack callback\n");
      err = ENOMEM;
      goto errout_datacb;
    }

  /* Get the initial sequence number that will be used */

  state.snd_isn          = tcp_getsequence(conn->sndseq);

  /* There is no outstanding, unacknowledged data after this
   * initial sequence number.
   */

  conn->unacked          = 0;

#ifdef CONFIG_NET_SOCKOPTS
  /* Set the initial time for calculating timeouts */

  state.snd_time         = clock_systimer();
#endif

  /* Set up the ACK callback in the connection */

  state.snd_ackcb->flags = (TCP_ACKDATA | TCP_REXMIT | TCP_DISCONN_EVENTS);
  state.snd_ackcb->priv  = (FAR void *)&state;
  state.snd_ackcb->event = ack_interrupt;

  /* Perform the TCP send operation */

  do
    {
      state.snd_datacb->flags = TCP_POLL;
      state.snd_datacb->priv  = (FAR void *)&state;
      state.snd_datacb->event = sendfile_interrupt;

      /* Notify the device driver of the availability of TX data */

      sendfile_txnotify(psock, conn);
      net_lockedwait(&state.snd_sem);
    }
  while (state.snd_sent >= 0 && state.snd_acked < state.snd_flen);

  /* Set the socket state to idle */

  psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);

  tcp_callback_free(conn, state.snd_ackcb);

errout_datacb:
  tcp_callback_free(conn, state.snd_datacb);

errout_locked:

  sem_destroy(&state. snd_sem);
  net_unlock(save);

errout:

  if (err)
    {
      set_errno(err);
      return ERROR;
    }
  else if (state.snd_sent < 0)
    {
      set_errno(-state.snd_sent);
      return ERROR;
    }
  else
    {
      return state.snd_sent;
    }
}
Beispiel #6
0
static uint16_t ack_interrupt(FAR struct net_driver_s *dev, FAR void *pvconn,
                              FAR void *pvpriv, uint16_t flags)
{
  FAR struct sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;

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

  if ((flags & TCP_ACKDATA) != 0)
    {
      FAR struct tcp_hdr_s *tcp;

#ifdef CONFIG_NET_SOCKOPTS
      /* Update the timeout */

      pstate->snd_time = clock_systimer();
#endif

      /* Get the offset address of the TCP header */

#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
      if (IFF_IS_IPv6(dev->d_flags))
#endif
        {
          DEBUGASSERT(pstate->snd_sock == PF_INET6);
          tcp = TCPIPv6BUF;
        }
#endif /* CONFIG_NET_IPv6 */

#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
      else
#endif
        {
          DEBUGASSERT(pstate->snd_sock == PF_INET);
          tcp = TCPIPv4BUF;
        }
#endif /* CONFIG_NET_IPv4 */

      /* The current acknowledgement number number is the (relative) offset
       * of the of the next byte needed by the receiver.  The snd_isn is the
       * offset of the first byte to send to the receiver.  The difference
       * is the number of bytes to be acknowledged.
       */

      pstate->snd_acked = tcp_getsequence(tcp->ackno) - pstate->snd_isn;
      nllvdbg("ACK: acked=%d sent=%d flen=%d\n",
             pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);

      dev->d_sndlen = 0;

      flags &= ~TCP_ACKDATA;
    }
  else if ((flags & TCP_REXMIT) != 0)
    {
      nlldbg("REXMIT\n");

      /* Yes.. in this case, reset the number of bytes that have been sent
       * to the number of bytes that have been ACKed.
       */

      pstate->snd_sent = pstate->snd_acked;
    }

  /* Check for a loss of connection */

  else if ((flags & TCP_DISCONN_EVENTS) != 0)
    {
      /* Report not connected */

      nlldbg("Lost connection\n");

      net_lostconnection(pstate->snd_sock, flags);
      pstate->snd_sent = -ENOTCONN;
    }

  /* Wake up the waiting thread */

  sem_post(&pstate->snd_sem);

  return flags;
}
Beispiel #7
0
void tcp_timer(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
               int hsec)
{
  uint16_t result;
  uint8_t hdrlen;

  /* Set up for the callback.  We can't know in advance if the application
   * is going to send a IPv4 or an IPv6 packet, so this setup may not
   * actually be used.  Furthermore, the TCP logic is required to call
   * tcp_ipv4_select() or tcp_ipv6_select() prior to sending any packets.
   * We will try to set the correct value here basic on the binding of
   * the connection.
   */

#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
  if (conn->domain == PF_INET)
#endif
    {
      hdrlen = IPv4TCP_HDRLEN;
      tcp_ipv4_select(dev);
    }
#endif /* CONFIG_NET_IPv4 */

#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
  else
#endif
    {
      hdrlen = IPv6TCP_HDRLEN;
      tcp_ipv6_select(dev);
    }
#endif /* CONFIG_NET_IPv6 */

  /* Increase the TCP sequence number */

  tcp_nextsequence();

  /* Reset the length variables. */

  dev->d_len    = 0;
  dev->d_sndlen = 0;

  /* Check if the connection is in a state in which we simply wait
   * for the connection to time out. If so, we increase the
   * connection's timer and remove the connection if it times
   * out.
   */

  if (conn->tcpstateflags == TCP_TIME_WAIT ||
      conn->tcpstateflags == TCP_FIN_WAIT_2)
    {
      unsigned int newtimer;

      /* Increment the connection timer */

      newtimer = (unsigned int)conn->timer + hsec;

      /* Check if the timer exceeds the timeout value */

      if (newtimer >= TCP_TIME_WAIT_TIMEOUT)
        {
          /* Set the timer to the maximum value */

          conn->timer = TCP_TIME_WAIT_TIMEOUT;

          /* The TCP connection was established and, hence, should be bound
           * to a device. Make sure that the polling device is the one that
           * we are bound to.
           *
           * If not, then we will catch the timeout on the next poll from
           * the correct device.
           */

          DEBUGASSERT(conn->dev != NULL);
          if (dev != conn->dev)
            {
              ninfo("TCP: TCP_CLOSED pending\n");
            }
          else
            {
              conn->tcpstateflags = TCP_CLOSED;

              /* Notify upper layers about the timeout */

              result = tcp_callback(dev, conn, TCP_TIMEDOUT);

              ninfo("TCP state: TCP_CLOSED\n");
            }
        }
      else
        {
          /* No timeout. Just update the incremented timer */

          conn->timer = newtimer;
        }
    }
  else if (conn->tcpstateflags != TCP_CLOSED)
    {
      /* If the connection has outstanding data, we increase the connection's
       * timer and see if it has reached the RTO value in which case we
       * retransmit.
       */

      if (conn->unacked > 0)
        {
          /* The connection has outstanding data */

          if (conn->timer > hsec)
            {
              /* Will not yet decrement to zero */

              conn->timer -= hsec;
            }
          else
            {
              /* Will decrement to zero */

              conn->timer = 0;

              /* The TCP is connected and, hence, should be bound to a
               * device. Make sure that the polling device is the one that
               * we are bound to.
               *
               * If not, then we will catch the timeout on the next poll
               * from the correct device.
               */

              DEBUGASSERT(conn->dev != NULL);
              if (dev != conn->dev)
                {
                  ninfo("TCP: TCP_CLOSED pending\n");
                  goto done;
                }

              /* Check for a timeout on connection in the TCP_SYN_RCVD state.
               * On such timeouts, we would normally resend the SYNACK until
               * the ACK is received, completing the 3-way handshake.  But if
               * the retry count elapsed, then we must assume that no ACK is
               * forthcoming and terminate the attempted connection.
               */

              if (conn->tcpstateflags == TCP_SYN_RCVD &&
                  conn->nrtx >= TCP_MAXSYNRTX)
                {
                  FAR struct tcp_conn_s *listener;

                  conn->tcpstateflags = TCP_CLOSED;
                  ninfo("TCP state: TCP_SYN_RCVD->TCP_CLOSED\n");

                  /* Find the listener for this connection. */

#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
                  listener = tcp_findlistener(conn->lport, conn->domain);
#else
                  listener = tcp_findlistener(conn->lport);
#endif
                  if (listener != NULL)
                    {
                      /* We call tcp_callback() for the connection with
                       * TCP_TIMEDOUT to inform the listener that the
                       * connection has timed out.
                       */

                      result = tcp_callback(dev, listener, TCP_TIMEDOUT);
                    }

                  /* We also send a reset packet to the remote host. */

                  tcp_send(dev, conn, TCP_RST | TCP_ACK, hdrlen);

                  /* Finally, we must free this TCP connection structure */

                  tcp_free(conn);
                  goto done;
                }

              /* Otherwise, check for a timeout on an established connection.
               * If the retry count is exceeded in this case, we should
               * close the connection.
               */

              else if (
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
                  conn->expired > 0 ||
#else
                  conn->nrtx >= TCP_MAXRTX ||
#endif
                  (conn->tcpstateflags == TCP_SYN_SENT &&
                   conn->nrtx >= TCP_MAXSYNRTX)
                 )
                {
                  conn->tcpstateflags = TCP_CLOSED;
                  ninfo("TCP state: TCP_CLOSED\n");

                  /* We call tcp_callback() with TCP_TIMEDOUT to
                   * inform the application that the connection has
                   * timed out.
                   */

                  result = tcp_callback(dev, conn, TCP_TIMEDOUT);

                  /* We also send a reset packet to the remote host. */

                  tcp_send(dev, conn, TCP_RST | TCP_ACK, hdrlen);
                  goto done;
                }

             /* Exponential backoff. */

              conn->timer = TCP_RTO << (conn->nrtx > 4 ? 4: conn->nrtx);
              (conn->nrtx)++;

              /* Ok, so we need to retransmit. We do this differently
               * depending on which state we are in. In ESTABLISHED, we
               * call upon the application so that it may prepare the
               * data for the retransmit. In SYN_RCVD, we resend the
               * SYNACK that we sent earlier and in LAST_ACK we have to
               * retransmit our FINACK.
               */

#ifdef CONFIG_NET_STATISTICS
              g_netstats.tcp.rexmit++;
#endif
              switch (conn->tcpstateflags & TCP_STATE_MASK)
                {
                  case TCP_SYN_RCVD:
                    /* In the SYN_RCVD state, we should retransmit our
                     * SYNACK.
                     */

                    tcp_ack(dev, conn, TCP_ACK | TCP_SYN);
                    goto done;

                  case TCP_SYN_SENT:
                    /* In the SYN_SENT state, we retransmit out SYN. */

                    tcp_ack(dev, conn, TCP_SYN);
                    goto done;

                  case TCP_ESTABLISHED:
                    /* In the ESTABLISHED state, we call upon the application
                     * to do the actual retransmit after which we jump into
                     * the code for sending out the packet.
                     */

                    result = tcp_callback(dev, conn, TCP_REXMIT);
                    tcp_rexmit(dev, conn, result);
                    goto done;

                  case TCP_FIN_WAIT_1:
                  case TCP_CLOSING:
                  case TCP_LAST_ACK:
                    /* In all these states we should retransmit a FINACK. */

                    tcp_send(dev, conn, TCP_FIN | TCP_ACK, hdrlen);
                    goto done;
                }
            }
        }

      /* The connection does not have outstanding data.  Check if the TCP
       * connection has been established.
       */

      else if ((conn->tcpstateflags & TCP_STATE_MASK) == TCP_ESTABLISHED)
        {
          /* The TCP connection is established and, hence, should be bound
           * to a device. Make sure that the polling device is the one that
           * we are bound to.
           */

          DEBUGASSERT(conn->dev != NULL);
          if (dev == conn->dev)
            {
#ifdef CONFIG_NET_TCP_KEEPALIVE
              /* Is this an established connected with KeepAlive enabled? */

              if (conn->keepalive)
                {
                  socktimeo_t timeo;
                  uint32_t saveseq;

                  /* If this is the first probe, then the keepstart time is
                   * the time that the last ACK or data was received from the
                   * remote.
                   *
                   * On subsequent retries, keepstart is the time that the
                   * last probe was sent.
                   */

                  if (conn->keepretries > 0)
                    {
                      timeo = (socktimeo_t)conn->keepintvl;
                    }
                  else
                    {
                      timeo = (socktimeo_t)conn->keepidle;
                    }

                  /* Yes... has the idle period elapsed with no data or ACK
                   * received from the remote peer?
                   */

                  if (net_timeo(conn->keeptime, timeo))
                    {
                      /* Yes.. Has the retry count expired? */

                      if (conn->keepretries >= conn->keepcnt)
                        {
                          /* Yes... stop the network monitor, closing the connection and all sockets
                           * associated with the connection.
                           */

                          tcp_stop_monitor(conn, TCP_ABORT);
                        }
                      else
                        {
                          unsigned int tcpiplen;

                          /* No.. we need to send another probe.
                           *
                           * Get the size of the IP header and the TCP header.
                           */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
                          if (conn->domain == PF_INET)
#endif
                            {
                              tcpiplen = IPv4_HDRLEN + TCP_HDRLEN;
                            }
#endif
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
                          else
#endif
                            {
                              tcpiplen = IPv6_HDRLEN + TCP_HDRLEN;
                            }
#endif

                          /* And send the probe (along with a garbage byte).
                           * The packet we sned must have these properties:
                           *
                           *   - TCP_ACK flag (only) is set.
                           *   - Sequence number is the sequence number of
                           *     previously ACKed data, i.e., the expected
                           *     sequence number minus one.
                           *   - The data payload is one or two bytes.
                           *
                           * tcp_send() will send the TCP sequence number as
                           * conn->sndseq.  Rather than creating a new
                           * interface, we spoof tcp_end() here:
                           */

                          saveseq = tcp_getsequence(conn->sndseq);
                          tcp_setsequence(conn->sndseq, saveseq - 1);

                          tcp_send(dev, conn, TCP_ACK, tcpiplen + 1);

                          tcp_setsequence(conn->sndseq, saveseq);

                          /* Increment the number of un-ACKed bytes due to the dummy
                           * byte that we just sent.
                           */

                          conn->unacked++;

#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
                          /* Increment the un-ACKed sequence number */

                          conn->sndseq_max++;
#endif
                          /* Update for the next probe */

                          conn->keeptime = clock_systimer();
                          conn->keepretries++;
                        }

                      goto done;
                    }
                }
#endif
              /* There was no need for a retransmission and there was no
               * need to probe the remote peer.  We poll the application for
               * new outgoing data.
               */

              result = tcp_callback(dev, conn, TCP_POLL);
              tcp_appsend(dev, conn, result);
              goto done;
            }
        }
    }

  /* Nothing to be done */

  dev->d_len = 0;

done:
  return;
}