static void tcp_sendcomplete(FAR struct net_driver_s *dev,
FAR struct tcp_hdr_s *tcp)
{
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
tcp_ipv6_sendcomplete(dev, tcp, IPv6BUF);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
tcp_ipv4_sendcomplete(dev, tcp, IPv4BUF);
}
#endif /* CONFIG_NET_IPv4 */
nllvdbg("Outgoing TCP packet length: %d bytes\n", dev->d_len);
#ifdef CONFIG_NET_STATISTICS
g_netstats.tcp.sent++;
#endif
}
static void tcp_sendcommon(FAR struct net_driver_s *dev,
FAR struct tcp_conn_s *conn,
FAR struct tcp_hdr_s *tcp)
{
/* Copy the IP address into the IPv6 header */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
net_ipv6addr_hdrcopy(ipv6->srcipaddr, dev->d_ipv6addr);
net_ipv6addr_hdrcopy(ipv6->destipaddr, conn->u.ipv6.raddr);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
net_ipv4addr_hdrcopy(ipv4->destipaddr, &conn->u.ipv4.raddr);
}
#endif /* CONFIG_NET_IPv4 */
/* Set TCP sequence numbers and port numbers */
memcpy(tcp->ackno, conn->rcvseq, 4);
memcpy(tcp->seqno, conn->sndseq, 4);
tcp->srcport = conn->lport;
tcp->destport = conn->rport;
/* Set the TCP window */
if (conn->tcpstateflags & TCP_STOPPED)
{
/* If the connection has issued TCP_STOPPED, we advertise a zero
* window so that the remote host will stop sending data.
*/
tcp->wnd[0] = 0;
tcp->wnd[1] = 0;
}
else
{
tcp->wnd[0] = ((NET_DEV_RCVWNDO(dev)) >> 8);
tcp->wnd[1] = ((NET_DEV_RCVWNDO(dev)) & 0xff);
}
/* Finish the IP portion of the message and calculate checksums */
tcp_sendcomplete(dev, tcp);
}
void tcp_ack(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
uint8_t ack)
{
struct tcp_hdr_s *tcp;
uint16_t tcp_mss;
/* Get values that vary with the underlying IP domain */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
/* Get the MSS value and offset TCP header address for this packet */
tcp = TCPIPv6BUF;
tcp_mss = TCP_IPv6_MSS(dev);
/* Set the the packet length for the TCP Maximum Segment Size */
dev->d_len = IPv6TCP_HDRLEN + TCP_OPT_MSS_LEN;
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
/* Get the MSS value and offset TCP header address for this packet */
tcp = TCPIPv4BUF;
tcp_mss = TCP_IPv4_MSS(dev);
/* Set the the packet length for the TCP Maximum Segment Size */
dev->d_len = IPv4TCP_HDRLEN + TCP_OPT_MSS_LEN;
}
#endif /* CONFIG_NET_IPv4 */
/* Save the ACK bits */
tcp->flags = ack;
/* We send out the TCP Maximum Segment Size option with our ack. */
tcp->optdata[0] = TCP_OPT_MSS;
tcp->optdata[1] = TCP_OPT_MSS_LEN;
tcp->optdata[2] = tcp_mss >> 8;
tcp->optdata[3] = tcp_mss & 0xff;
tcp->tcpoffset = ((TCP_HDRLEN + TCP_OPT_MSS_LEN) / 4) << 4;
/* Complete the common portions of the TCP message */
tcp_sendcommon(dev, conn, tcp);
}
static inline FAR struct tcp_hdr_s *tcp_header(FAR struct net_driver_s *dev)
{
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
return TCPIPv6BUF;
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
return TCPIPv4BUF;
}
#endif /* CONFIG_NET_IPv4 */
}
FAR struct tcp_conn_s *tcp_active(FAR struct net_driver_s *dev,
FAR struct tcp_hdr_s *tcp)
{
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
return tcp_ipv6_active(dev, tcp);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
return tcp_ipv4_active(dev, tcp);
}
#endif /* CONFIG_NET_IPv4 */
}
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;
}
#ifdef CONFIG_NET_STATISTICS
g_netstats.ipv4.sent++;
#endif
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
/* Get pointers to the IPv6 header and the offset TCP header */
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
DEBUGASSERT(IFF_IS_IPv6(dev->d_flags));
udp = UDPIPv6BUF;
/* Initialize the IPv6 header. Note that the IP length field
* does not include the IPv6 IP header length.
*/
ipv6->vtc = 0x60;
ipv6->tcf = 0x00;
ipv6->flow = 0x00;
ipv6->proto = IP_PROTO_UDP;
ipv6->ttl = conn->ttl;
net_ipv6addr_copy(ipv6->srcipaddr, dev->d_ipv6addr);
net_ipv6addr_copy(ipv6->destipaddr, conn->u.ipv6.raddr);
static uint16_t udp_datahandler(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn,
FAR uint8_t *buffer, uint16_t buflen)
{
FAR struct iob_s *iob;
int ret;
#ifdef CONFIG_NET_IPv6
FAR struct sockaddr_in6 src_addr6;
#endif
#ifdef CONFIG_NET_IPv4
FAR struct sockaddr_in src_addr4;
#endif
FAR void *src_addr;
uint8_t src_addr_size;
/* Allocate on I/O buffer to start the chain (throttling as necessary).
* We will not wait for an I/O buffer to become available in this context.
*/
iob = iob_tryalloc(true);
if (iob == NULL)
{
nerr("ERROR: Failed to create new I/O buffer chain\n");
return 0;
}
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
src_addr6.sin6_family = AF_INET6;
src_addr6.sin6_port = udp->srcport;
net_ipv6addr_copy(src_addr6.sin6_addr.s6_addr, ipv6->srcipaddr);
src_addr_size = sizeof(src_addr6);
src_addr = &src_addr6;
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
#ifdef CONFIG_NET_IPv6
/* Hybrid dual-stack IPv6/IPv4 implementations recognize a special
* class of addresses, the IPv4-mapped IPv6 addresses.
*/
if (conn->domain == PF_INET6)
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
in_addr_t ipv4addr;
/* Encode the IPv4 address as an IPv-mapped IPv6 address */
src_addr6.sin6_family = AF_INET6;
src_addr6.sin6_port = udp->srcport;
ipv4addr = net_ip4addr_conv32(ipv6->srcipaddr);
ip6_map_ipv4addr(ipv4addr, src_addr6.sin6_addr.s6_addr16);
src_addr_size = sizeof(src_addr6);
src_addr = &src_addr6;
}
else
#endif
{
FAR struct udp_hdr_s *udp = UDPIPv4BUF;
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
src_addr4.sin_family = AF_INET;
src_addr4.sin_port = udp->srcport;
net_ipv4addr_copy(src_addr4.sin_addr.s_addr,
net_ip4addr_conv32(ipv4->srcipaddr));
src_addr_size = sizeof(src_addr4);
src_addr = &src_addr4;
}
}
#endif /* CONFIG_NET_IPv4 */
/* Copy the src address info into the I/O buffer chain. We will not wait
* for an I/O buffer to become available in this context. It there is
* any failure to allocated, the entire I/O buffer chain will be discarded.
*/
ret = iob_trycopyin(iob, (FAR const uint8_t *)&src_addr_size,
sizeof(uint8_t), 0, true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
ret = iob_trycopyin(iob, (FAR const uint8_t *)src_addr, src_addr_size,
sizeof(uint8_t), true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
if (buflen > 0)
{
/* Copy the new appdata into the I/O buffer chain */
ret = iob_trycopyin(iob, buffer, buflen,
src_addr_size + sizeof(uint8_t), true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but
* does not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n",
ret);
(void)iob_free_chain(iob);
return 0;
}
}
/* Add the new I/O buffer chain to the tail of the read-ahead queue */
ret = iob_tryadd_queue(iob, &conn->readahead);
if (ret < 0)
{
nerr("ERROR: Failed to queue the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
#ifdef CONFIG_UDP_READAHEAD_NOTIFIER
/* Provided notification(s) that additional UDP read-ahead data is
* available.
*/
udp_notifier_signal(conn);
#endif
ninfo("Buffered %d bytes\n", buflen);
return buflen;
}
void tcp_appsend(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
uint16_t result)
{
uint8_t hdrlen;
/* Handle the result based on the application response */
nllvdbg("result: %04x d_sndlen: %d conn->unacked: %d\n",
result, dev->d_sndlen, conn->unacked);
/* Get the IP header length associated with the IP domain configured for
* this TCP connection.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
DEBUGASSERT(IFF_IS_IPv4(dev->d_flags));
hdrlen = IPv4TCP_HDRLEN;
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
DEBUGASSERT(IFF_IS_IPv6(dev->d_flags));
hdrlen = IPv6TCP_HDRLEN;
}
#endif /* CONFIG_NET_IPv6 */
/* Check for connection aborted */
if ((result & TCP_ABORT) != 0)
{
dev->d_sndlen = 0;
conn->tcpstateflags = TCP_CLOSED;
nllvdbg("TCP state: TCP_CLOSED\n");
tcp_send(dev, conn, TCP_RST | TCP_ACK, hdrlen);
}
/* Check for connection closed */
else if ((result & TCP_CLOSE) != 0)
{
conn->tcpstateflags = TCP_FIN_WAIT_1;
conn->unacked = 1;
conn->nrtx = 0;
nllvdbg("TCP state: TCP_FIN_WAIT_1\n");
dev->d_sndlen = 0;
tcp_send(dev, conn, TCP_FIN | TCP_ACK, hdrlen);
}
/* None of the above */
else
{
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
DEBUGASSERT(dev->d_sndlen >= 0 && dev->d_sndlen <= conn->mss);
#else
/* If d_sndlen > 0, the application has data to be sent. */
if (dev->d_sndlen > 0)
{
/* 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. Retransmissions
* do not go through this path.
*/
conn->unacked += dev->d_sndlen;
/* The application cannot send more than what is allowed by the
* MSS (the minumum of the MSS and the available window).
*/
DEBUGASSERT(dev->d_sndlen <= conn->mss);
}
conn->nrtx = 0;
#endif
/* Then handle the rest of the operation just as for the rexmit case */
tcp_rexmit(dev, conn, result);
}
}
void tcp_rexmit(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
uint16_t result)
{
uint8_t hdrlen;
nllvdbg("result: %04x d_sndlen: %d conn->unacked: %d\n",
result, dev->d_sndlen, conn->unacked);
/* Get the IP header length associated with the IP domain configured for
* this TCP connection.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
DEBUGASSERT(IFF_IS_IPv4(dev->d_flags));
hdrlen = IPv4TCP_HDRLEN;
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
DEBUGASSERT(IFF_IS_IPv6(dev->d_flags));
hdrlen = IPv6TCP_HDRLEN;
}
#endif /* CONFIG_NET_IPv6 */
/* If the application has data to be sent, or if the incoming packet had
* new data in it, we must send out a packet.
*/
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
if (dev->d_sndlen > 0)
#else
if (dev->d_sndlen > 0 && conn->unacked > 0)
#endif
{
/* We always set the ACK flag in response packets adding the length of
* the IP and TCP headers.
*/
tcp_send(dev, conn, TCP_ACK | TCP_PSH, dev->d_sndlen + hdrlen);
}
/* If there is no data to send, just send out a pure ACK if one is requested`. */
else if ((result & TCP_SNDACK) != 0)
{
tcp_send(dev, conn, TCP_ACK, hdrlen);
}
/* There is nothing to do -- drop the packet */
else
{
dev->d_len = 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;
}
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;
#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
ninfo("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 struct tcp_hdr_s *tcp;
FAR sq_entry_t *entry;
FAR sq_entry_t *next;
uint32_t ackno;
/* 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 */
/* Get the ACK number from the TCP header */
ackno = tcp_getsequence(tcp->ackno);
ninfo("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);
ninfo("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)
{
ninfo("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);
}
ninfo("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 */
ninfo("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);
}
ninfo("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;
ninfo("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_DISCONN_EVENTS) != 0)
{
ninfo("Lost connection: %04x\n", flags);
if (psock->s_conn != NULL)
{
/* 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;
ninfo("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);
ninfo("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;
ninfo("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)
{
nwarn("WARNING: 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;
ninfo("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)
{
nwarn("WARNING: 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 sequence number
* is pulled from the write_q again.
*/
ninfo("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 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 (psock_send_addrchck(conn))
{
FAR struct tcp_wrbuffer_s *wrb;
uint32_t predicted_seqno;
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 > conn->mss)
{
sndlen = conn->mss;
}
if (sndlen > conn->winsize)
{
sndlen = conn->winsize;
}
ninfo("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));
#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.
*/
send_ipselect(dev, psock);
#endif
/* 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;
/* Below prediction will become true, unless retransmission occurrence */
predicted_seqno = tcp_getsequence(conn->sndseq) + sndlen;
if ((predicted_seqno > conn->sndseq_max) ||
(tcp_getsequence(conn->sndseq) > predicted_seqno)) /* overflow */
{
conn->sndseq_max = predicted_seqno;
}
ninfo("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;
ninfo("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;
ninfo("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_reset(FAR struct net_driver_s *dev)
{
FAR struct tcp_hdr_s *tcp = tcp_header(dev);
uint16_t tmp16;
uint8_t seqbyte;
#ifdef CONFIG_NET_STATISTICS
g_netstats.tcp.rst++;
#endif
/* TCP setup */
tcp->flags = TCP_RST | TCP_ACK;
tcp->tcpoffset = 5 << 4;
/* Flip the seqno and ackno fields in the TCP header. */
seqbyte = tcp->seqno[3];
tcp->seqno[3] = tcp->ackno[3];
tcp->ackno[3] = seqbyte;
seqbyte = tcp->seqno[2];
tcp->seqno[2] = tcp->ackno[2];
tcp->ackno[2] = seqbyte;
seqbyte = tcp->seqno[1];
tcp->seqno[1] = tcp->ackno[1];
tcp->ackno[1] = seqbyte;
seqbyte = tcp->seqno[0];
tcp->seqno[0] = tcp->ackno[0];
tcp->ackno[0] = seqbyte;
/* We also have to increase the sequence number we are
* acknowledging. If the least significant byte overflowed, we need
* to propagate the carry to the other bytes as well.
*/
if (++(tcp->ackno[3]) == 0)
{
if (++(tcp->ackno[2]) == 0)
{
if (++(tcp->ackno[1]) == 0)
{
++(tcp->ackno[0]);
}
}
}
/* Swap port numbers. */
tmp16 = tcp->srcport;
tcp->srcport = tcp->destport;
tcp->destport = tmp16;
/* Set the packet length and swap IP addresses. */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
/* Set the packet length to the size of the IPv6 + TCP headers */
dev->d_len = IPv6TCP_HDRLEN;
/* Swap IPv6 addresses */
net_ipv6addr_hdrcopy(ipv6->destipaddr, ipv6->srcipaddr);
net_ipv6addr_hdrcopy(ipv6->srcipaddr, dev->d_ipv6addr);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
/* Set the packet length to the size of the IPv4 + TCP headers */
dev->d_len = IPv4TCP_HDRLEN;
/* Swap IPv4 addresses */
net_ipv4addr_hdrcopy(ipv4->destipaddr, ipv4->srcipaddr);
net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
}
#endif /* CONFIG_NET_IPv4 */
/* And send out the RST packet */
tcp_sendcomplete(dev, tcp);
}
FAR struct tcp_conn_s *tcp_alloc_accept(FAR struct net_driver_s *dev,
FAR struct tcp_hdr_s *tcp)
{
FAR struct tcp_conn_s *conn;
uint8_t domain;
int ret;
/* Get the appropriate IP domain */
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv4)
bool ipv6 = IFF_IS_IPv6(dev->d_flags);
domain = ipv6 ? PF_INET6 : PF_INET;
#elif defined(CONFIG_NET_IPv4)
domain = PF_INET;
#else /* defined(CONFIG_NET_IPv6) */
domain = PF_INET6;
#endif
/* Allocate the connection structure */
conn = tcp_alloc(domain);
if (conn)
{
/* Set up the local address (laddr) and the remote address (raddr)
* that describes the TCP connection.
*/
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (ipv6)
#endif
{
FAR struct ipv6_hdr_s *ip = IPv6BUF;
/* Set the IPv6 specific MSS and the IPv6 locally bound address */
conn->mss = TCP_IPv6_INITIAL_MSS(dev);
net_ipv6addr_copy(conn->u.ipv6.raddr, ip->srcipaddr);
#ifdef CONFIG_NETDEV_MULTINIC
net_ipv6addr_copy(conn->u.ipv6.laddr, ip->destipaddr);
/* We now have to filter all outgoing transfers so that they use
* only the MSS of this device.
*/
DEBUGASSERT(conn->dev == NULL || conn->dev == dev);
conn->dev = dev;
#endif
/* Find the device that can receive packets on the network
* associated with this local address.
*/
ret = tcp_remote_ipv6_device(conn);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
FAR struct ipv4_hdr_s *ip = IPv4BUF;
/* Set the IPv6 specific MSS and the IPv4 bound remote address. */
conn->mss = TCP_IPv4_INITIAL_MSS(dev);
net_ipv4addr_copy(conn->u.ipv4.raddr,
net_ip4addr_conv32(ip->srcipaddr));
#ifdef CONFIG_NETDEV_MULTINIC
/* Set the local address as well */
net_ipv4addr_copy(conn->u.ipv4.laddr,
net_ip4addr_conv32(ip->destipaddr));
/* We now have to filter all outgoing transfers so that they use
* only the MSS of this device.
*/
DEBUGASSERT(conn->dev == NULL || conn->dev == dev);
conn->dev = dev;
#endif
/* Find the device that can receive packets on the network
* associated with this local address.
*/
ret = tcp_remote_ipv4_device(conn);
}
#endif /* CONFIG_NET_IPv4 */
/* Verify that a network device that can provide packets to this
* local address was found.
*/
if (ret < 0)
{
/* If no device is found, then the address is not reachable.
* That should be impossible in this context and we should
* probably really just assert here.
*/
nerr("ERROR: Failed to find network device: %d\n", ret);
tcp_free(conn);
return NULL;
}
/* Fill in the necessary fields for the new connection. */
conn->rto = TCP_RTO;
conn->timer = TCP_RTO;
conn->sa = 0;
conn->sv = 4;
conn->nrtx = 0;
conn->lport = tcp->destport;
conn->rport = tcp->srcport;
conn->tcpstateflags = TCP_SYN_RCVD;
tcp_initsequence(conn->sndseq);
conn->unacked = 1;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
conn->expired = 0;
conn->isn = 0;
conn->sent = 0;
conn->sndseq_max = 0;
#endif
/* rcvseq should be the seqno from the incoming packet + 1. */
memcpy(conn->rcvseq, tcp->seqno, 4);
#ifdef CONFIG_NET_TCP_READAHEAD
/* Initialize the list of TCP read-ahead buffers */
IOB_QINIT(&conn->readahead);
#endif
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
/* Initialize the write buffer lists */
sq_init(&conn->write_q);
sq_init(&conn->unacked_q);
#endif
/* And, finally, put the connection structure into the active list.
* Interrupts should already be disabled in this context.
*/
dq_addlast(&conn->node, &g_active_tcp_connections);
}
return conn;
}