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;
}
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;
}
static uint16_t sendfile_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 sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;
int ret;
#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 own 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);
/* Check for a loss of connection */
if ((flags & TCP_DISCONN_EVENTS) != 0)
{
/* Report not connected */
nlldbg("Lost connection\n");
net_lostconnection(pstate->snd_sock, flags);
pstate->snd_sent = -ENOTCONN;
goto end_wait;
}
/* 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
* unprocessing 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_flen)
{
/* Get the amount of data that we can send in the next packet */
uint32_t sndlen = pstate->snd_flen - pstate->snd_sent;
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)
{
uint32_t seqno;
/* Then set-up to send that amount of data. (this won't actually
* happen until the polling cycle completes).
*/
ret = file_seek(pstate->snd_file,
pstate->snd_foffset + pstate->snd_sent, SEEK_SET);
if (ret < 0)
{
int errcode = get_errno();
nlldbg("failed to lseek: %d\n", errcode);
pstate->snd_sent = -errcode;
goto end_wait;
}
ret = file_read(pstate->snd_file, dev->d_appdata, sndlen);
if (ret < 0)
{
int errcode = get_errno();
nlldbg("failed to read from input file: %d\n", errcode);
pstate->snd_sent = -errcode;
goto end_wait;
}
dev->d_sndlen = sndlen;
/* Set the sequence number for this packet. NOTE: The network updates
* sndseq on recept of ACK *before* this function is called. In that
* case sndseq will point to the next unacknowledge 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 len: %d\n", conn->sndseq, seqno, ret);
tcp_setsequence(conn->sndseq, seqno);
/* 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 || sendfile_addrcheck(conn))
{
/* Update the amount of data sent (but not necessarily ACKed) */
pstate->snd_sent += sndlen;
nllvdbg("pid: %d SEND: acked=%d sent=%d flen=%d\n", getpid(),
pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);
}
}
else
{
nlldbg("Window full, wait for ack\n");
goto wait;
}
}
#ifdef CONFIG_NET_SOCKOPTS
/* All data has been send and we are just waiting for ACK or re-transmit
* indications to complete the send. Check for a timeout.
*/
if (sendfile_timeout(pstate))
{
/* Yes.. report the timeout */
nlldbg("SEND timeout\n");
pstate->snd_sent = -ETIMEDOUT;
goto end_wait;
}
#endif /* CONFIG_NET_SOCKOPTS */
if (pstate->snd_sent >= pstate->snd_flen
&& pstate->snd_acked < pstate->snd_flen)
{
/* All data has been sent, but there are outstanding ACK's */
goto wait;
}
end_wait:
/* Do not allow any further callbacks */
pstate->snd_datacb->flags = 0;
pstate->snd_datacb->priv = NULL;
pstate->snd_datacb->event = NULL;
/* Wake up the waiting thread */
sem_post(&pstate->snd_sem);
wait:
return flags;
}
static uint16_t sendfile_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 sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;
int ret;
nllvdbg("flags: %04x acked: %d sent: %d\n",
flags, pstate->snd_acked, pstate->snd_sent);
/* Check for a loss of connection */
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;
goto end_wait;
}
/* 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
* unprocessing 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_flen)
{
/* Get the amount of data that we can send in the next packet */
uint32_t sndlen = pstate->snd_flen - pstate->snd_sent;
if (sndlen > tcp_mss(conn))
{
sndlen = tcp_mss(conn);
}
/* Check if we have "space" in the window */
if ((pstate->snd_sent - pstate->snd_acked + sndlen) < conn->winsize)
{
uint32_t seqno;
/* Then set-up to send that amount of data. (this won't actually
* happen until the polling cycle completes).
*/
ret = file_seek(pstate->snd_file,
pstate->snd_foffset + pstate->snd_sent, SEEK_SET);
if (ret < 0)
{
int errcode = errno;
nlldbg("failed to lseek: %d\n", errcode);
pstate->snd_sent = -errcode;
goto end_wait;
}
ret = file_read(pstate->snd_file, dev->d_snddata, sndlen);
if (ret < 0)
{
int errcode = errno;
nlldbg("failed to read from input file: %d\n", errcode);
pstate->snd_sent = -errcode;
goto end_wait;
}
dev->d_sndlen = sndlen;
/* Set the sequence number for this packet. NOTE: uIP updates
* sndseq on recept of ACK *before* this function is called. In that
* case sndseq will point to the next unacknowledge 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 len: %d\n", conn->sndseq, seqno, ret);
tcp_setsequence(conn->sndseq, seqno);
/* 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. Hence, we only check on the first packet -- when
* snd_sent is zero.
*
* 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 (pstate->snd_sent != 0 || arp_find(conn->ripaddr) != NULL)
#endif
{
/* Update the amount of data sent (but not necessarily ACKed) */
pstate->snd_sent += sndlen;
nllvdbg("pid: %d SEND: acked=%d sent=%d flen=%d\n", getpid(),
pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);
}
}
else
{
nlldbg("Window full, wait for ack\n");
goto wait;
}
}
#ifdef CONFIG_NET_SOCKOPTS
/* All data has been send and we are just waiting for ACK or re-transmit
* indications to complete the send. Check for a timeout.
*/
if (sendfile_timeout(pstate))
{
/* Yes.. report the timeout */
nlldbg("SEND timeout\n");
pstate->snd_sent = -ETIMEDOUT;
goto end_wait;
}
#endif /* CONFIG_NET_SOCKOPTS */
if (pstate->snd_sent >= pstate->snd_flen
&& pstate->snd_acked < pstate->snd_flen)
{
/* All data has been sent, but there are outstanding ACK's */
goto wait;
}
end_wait:
/* Do not allow any further callbacks */
pstate->snd_datacb->flags = 0;
pstate->snd_datacb->priv = NULL;
pstate->snd_datacb->event = NULL;
/* Wake up the waiting thread */
sem_post(&pstate->snd_sem);
wait:
return flags;
}
