/****************************************************************************
* net/tcp/tcp_send_buffered.c
*
* Copyright (C) 2007-2014, 2016-2018 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
* Jason Jiang <jasonj@live.cn>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) && \
defined(CONFIG_NET_TCP_WRITE_BUFFERS)
#if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_NET_TCP_WRBUFFER_DEBUG)
/* Force debug output (from this file only) */
# undef CONFIG_DEBUG_NET
# define CONFIG_DEBUG_NET 1
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <debug.h>
#include <arch/irq.h>
#include <nuttx/clock.h>
#include <nuttx/net/net.h>
#include <nuttx/mm/iob.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/arp.h>
#include <nuttx/net/tcp.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "socket/socket.h"
#include "inet/inet.h"
#include "arp/arp.h"
#include "icmpv6/icmpv6.h"
#include "neighbor/neighbor.h"
#include "route/route.h"
#include "tcp/tcp.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* If both IPv4 and IPv6 support are both enabled, then we will need to build
* in some additional domain selection support.
*/
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
# define NEED_IPDOMAIN_SUPPORT 1
#endif
#define TCPIPv4BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN])
#define TCPIPv6BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
/* Debug */
#ifdef CONFIG_NET_TCP_WRBUFFER_DUMP
# define BUF_DUMP(msg,buf,len) lib_dumpbuffer(msg,buf,len)
#else
# define BUF_DUMP(msg,buf,len)
# undef TCP_WBDUMP
# define TCP_WBDUMP(msg,wrb,len,offset)
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: psock_insert_segment
*
* Description:
* Insert a new segment in a write buffer queue, keep the segment queue in
* ascending order of sequence number.
*
* Input Parameters:
* wrb The segment to be inserted
* q The write buffer queue in which to insert the segment
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
static void psock_insert_segment(FAR struct tcp_wrbuffer_s *wrb,
FAR sq_queue_t *q)
{
FAR sq_entry_t *entry = (FAR sq_entry_t *)wrb;
FAR sq_entry_t *insert = NULL;
FAR sq_entry_t *itr;
for (itr = sq_peek(q); itr; itr = sq_next(itr))
{
FAR struct tcp_wrbuffer_s *wrb0 = (FAR struct tcp_wrbuffer_s *)itr;
if (TCP_WBSEQNO(wrb0) < TCP_WBSEQNO(wrb))
{
insert = itr;
}
else
{
break;
}
}
if (insert)
{
sq_addafter(insert, entry, q);
}
else
{
sq_addfirst(entry, q);
}
}
/****************************************************************************
* Name: psock_lost_connection
*
* Description:
* The TCP connection has been lost. Free all write buffers.
*
* Input Parameters:
* psock The socket structure
* conn The connection structure associated with the socket
*
* Returned Value:
* None
*
****************************************************************************/
static inline void psock_lost_connection(FAR struct socket *psock,
FAR struct tcp_conn_s *conn)
{
FAR sq_entry_t *entry;
FAR sq_entry_t *next;
/* Do not allow any further callbacks */
if (psock->s_sndcb != NULL)
{
psock->s_sndcb->flags = 0;
psock->s_sndcb->event = NULL;
}
if (conn != NULL)
{
/* Free all queued write buffers */
for (entry = sq_peek(&conn->unacked_q); entry; entry = next)
{
next = sq_next(entry);
tcp_wrbuffer_release((FAR struct tcp_wrbuffer_s *)entry);
}
for (entry = sq_peek(&conn->write_q); entry; entry = next)
{
next = sq_next(entry);
tcp_wrbuffer_release((FAR struct tcp_wrbuffer_s *)entry);
}
/* Reset write buffering variables */
sq_init(&conn->unacked_q);
sq_init(&conn->write_q);
conn->sent = 0;
conn->sndseq_max = 0;
}
}
/****************************************************************************
* Name: send_ipselect
*
* Description:
* 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.
*
* Input Parameters:
* dev - The structure of the network driver that caused the event
* psock - Socket state structure
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
#ifdef NEED_IPDOMAIN_SUPPORT
static inline void send_ipselect(FAR struct net_driver_s *dev,
FAR struct tcp_conn_s *conn)
{
/* Which domain the socket support */
if (conn->domain == PF_INET)
{
/* Select the IPv4 domain */
tcp_ipv4_select(dev);
}
else /* if (conn->domain == PF_INET6) */
{
/* Select the IPv6 domain */
DEBUGASSERT(conn->domain == PF_INET6);
tcp_ipv6_select(dev);
}
}
#endif
/****************************************************************************
* Name: psock_send_addrchck
*
* Description:
* Check if the destination IP address is in the IPv4 ARP or IPv6 Neighbor
* tables. If not, then the send won't actually make it out... it will be
* replaced with an ARP request (IPv4) or a Neighbor Solicitation (IPv6).
*
* NOTE 1: This could be an expensive check if there are a lot of
* entries in the ARP or Neighbor tables.
*
* 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 (IPv4 only).
*
* NOTE 3: If CONFIG_NET_ARP_SEND then we can be assured that the IP
* address mapping is already in the ARP table.
*
* Input Parameters:
* conn - The TCP connection structure
*
* Returned Value:
* true - The Ethernet MAC address is in the ARP or Neighbor table (OR
* the network device is not Ethernet).
*
* Assumptions:
* The network is locked
*
****************************************************************************/
#ifdef CONFIG_NET_ETHERNET
static inline bool psock_send_addrchck(FAR struct tcp_conn_s *conn)
{
/* Only Ethernet drivers are supported by this function */
/* REVISIT: Could the MAC address not also be in a routing table? */
if (conn->dev->d_lltype != NET_LL_ETHERNET)
{
return true;
}
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
/* For historical reasons, we will return true if both the ARP and the
* routing table are disabled.
*/
bool ret = true;
#ifdef CONFIG_NET_ROUTE
in_addr_t router;
#endif
#if !defined(CONFIG_NET_ARP_IPIN) && !defined(CONFIG_NET_ARP_SEND)
if (arp_find(conn->u.ipv4.raddr, NULL) >= 0)
{
/* Return true if the address was found in the ARP table */
return true;
}
/* Otherwise, return false */
ret = false;
#endif
#ifdef CONFIG_NET_ROUTE
if (net_ipv4_router(conn->u.ipv4.raddr, &router) == OK)
{
/* Return true if the address was found in the routing table */
return true;
}
/* Otherwise, return false */
ret = false;
#endif
return ret;
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
/* For historical reasons, we will return true if both the ICMPv6
* neighbor support and the routing table are disabled.
*/
bool ret = true;
#ifdef CONFIG_NET_ROUTE
net_ipv6addr_t router;
#endif
#if !defined(CONFIG_NET_ICMPv6_NEIGHBOR)
if (neighbor_findentry(conn->u.ipv6.raddr) != NULL)
{
/* Return true if the address was found in the ARP table */
return true;
}
/* Otherwise, return false */
ret = false;
#endif
#ifdef CONFIG_NET_ROUTE
if (net_ipv6_router(conn->u.ipv6.raddr, router) == OK)
{
/* Return true if the address was found in the routing table */
return true;
}
/* Otherwise, return false */
ret = false;
#endif
return ret;
}
#endif /* CONFIG_NET_IPv6 */
}
#else /* CONFIG_NET_ETHERNET */
# define psock_send_addrchck(r) (true)
#endif /* CONFIG_NET_ETHERNET */
/****************************************************************************
* Name: psock_send_eventhandler
*
* Description:
* This function is called to perform the actual send operation when
* polled by the lower, device interfacing layer.
*
* Input Parameters:
* dev The structure of the network driver that caused the event
* conn The connection structure associated with the socket
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
static uint16_t psock_send_eventhandler(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;
/* 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;
}
ninfo("flags: %04x\n", flags);
/* If this packet contains an acknowledgment, 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 > TCP_WBSEQNO(wrb))
{
/* Get the sequence number at the end of the data */
lastseq = TCP_WBSEQNO(wrb) + TCP_WBPKTLEN(wrb);
ninfo("ACK: wrb=%p seqno=%u lastseq=%u pktlen=%u ackno=%u\n",
wrb, TCP_WBSEQNO(wrb), lastseq, TCP_WBPKTLEN(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 - TCP_WBSEQNO(wrb);
if (trimlen > TCP_WBSENT(wrb))
{
/* More data has been ACKed then we have sent? */
trimlen = TCP_WBSENT(wrb);
}
ninfo("ACK: wrb=%p trim %u bytes\n", wrb, trimlen);
TCP_WBTRIM(wrb, trimlen);
TCP_WBSEQNO(wrb) = ackno;
TCP_WBSENT(wrb) -= trimlen;
/* Set the new sequence number for what remains */
ninfo("ACK: wrb=%p seqno=%u pktlen=%u\n",
wrb, TCP_WBSEQNO(wrb), TCP_WBPKTLEN(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 && TCP_WBSENT(wrb) > 0 && ackno > TCP_WBSEQNO(wrb))
{
uint32_t nacked;
/* Number of bytes that were ACKed */
nacked = ackno - TCP_WBSEQNO(wrb);
if (nacked > TCP_WBSENT(wrb))
{
/* More data has been ACKed then we have sent? ASSERT? */
nacked = TCP_WBSENT(wrb);
}
ninfo("ACK: wrb=%p seqno=%u nacked=%u sent=%u ackno=%u\n",
wrb, TCP_WBSEQNO(wrb), nacked, TCP_WBSENT(wrb), ackno);
/* Trim the ACKed bytes from the beginning of the write buffer. */
TCP_WBTRIM(wrb, nacked);
TCP_WBSEQNO(wrb) = ackno;
TCP_WBSENT(wrb) -= nacked;
ninfo("ACK: wrb=%p seqno=%u pktlen=%u sent=%u\n",
wrb, TCP_WBSEQNO(wrb), TCP_WBPKTLEN(wrb), TCP_WBSENT(wrb));
}
}
/* Check for a loss of connection */
else if ((flags & TCP_DISCONN_EVENTS) != 0)
{
ninfo("Lost connection: %04x\n", flags);
/* We could get here recursively through the callback actions of
* tcp_lost_connection(). So don't repeat that action if we have
* already been disconnected.
*/
if (psock->s_conn != NULL && _SS_ISCONNECTED(psock->s_flags))
{
/* Report not connected */
tcp_lost_connection(psock, psock->s_sndcb, 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 ? TCP_WBSENT(wrb) : 0);
if (wrb != NULL && TCP_WBSENT(wrb) > 0)
{
FAR struct tcp_wrbuffer_s *tmp;
uint16_t sent;
/* Yes.. Reset the number of bytes sent sent from the write buffer */
sent = TCP_WBSENT(wrb);
if (conn->unacked > sent)
{
conn->unacked -= sent;
}
else
{
conn->unacked = 0;
}
if (conn->sent > sent)
{
conn->sent -= sent;
}
else
{
conn->sent = 0;
}
TCP_WBSENT(wrb) = 0;
ninfo("REXMIT: wrb=%p sent=%u, conn unacked=%d sent=%d\n",
wrb, TCP_WBSENT(wrb), conn->unacked, conn->sent);
/* Increment the retransmit count on this write buffer. */
if (++TCP_WBNRTX(wrb) >= TCP_MAXRTX)
{
nwarn("WARNING: Expiring wrb=%p nrtx=%u\n",
wrb, TCP_WBNRTX(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 = TCP_WBSENT(wrb);
if (conn->unacked > sent)
{
conn->unacked -= sent;
}
else
{
conn->unacked = 0;
}
if (conn->sent > sent)
{
conn->sent -= sent;
}
else
{
conn->sent = 0;
}
TCP_WBSENT(wrb) = 0;
ninfo("REXMIT: wrb=%p sent=%u, conn unacked=%d sent=%d\n",
wrb, TCP_WBSENT(wrb), conn->unacked, conn->sent);
/* Free any write buffers that have exceed the retry count */
if (++TCP_WBNRTX(wrb) >= TCP_MAXRTX)
{
nwarn("WARNING: Expiring wrb=%p nrtx=%u\n",
wrb, TCP_WBNRTX(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, TCP_WBNRTX(wrb));
psock_insert_segment(wrb, &conn->write_q);
}
}
}
/* Check if the outgoing packet is available (it may have been claimed
* by a sendto event 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 = TCP_WBPKTLEN(wrb) - TCP_WBSENT(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, TCP_WBPKTLEN(wrb), TCP_WBSENT(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 (TCP_WBSEQNO(wrb) == (unsigned)-1)
{
TCP_WBSEQNO(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, TCP_WBSEQNO(wrb) + TCP_WBSENT(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, conn);
#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, TCP_WBIOB(wrb), sndlen, TCP_WBSENT(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, TCP_WBNRTX(wrb), conn->unacked, conn->sent);
/* Increment the count of bytes sent from this write buffer */
TCP_WBSENT(wrb) += sndlen;
ninfo("SEND: wrb=%p sent=%u pktlen=%u\n",
wrb, TCP_WBSENT(wrb), TCP_WBPKTLEN(wrb));
/* Remove the write buffer from the write queue if the
* last of the data has been sent from the buffer.
*/
DEBUGASSERT(TCP_WBSENT(wrb) <= TCP_WBPKTLEN(wrb));
if (TCP_WBSENT(wrb) >= TCP_WBPKTLEN(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;
}
/****************************************************************************
* Name: send_txnotify
*
* Description:
* Notify the appropriate device driver that we are have data ready to
* be send (TCP)
*
* Input Parameters:
* psock - Socket state structure
* conn - The TCP connection structure
*
* Returned Value:
* None
*
****************************************************************************/
static inline void send_txnotify(FAR struct socket *psock,
FAR struct tcp_conn_s *conn)
{
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
/* If both IPv4 and IPv6 support are enabled, then we will need to select
* the device driver using the appropriate IP domain.
*/
if (psock->s_domain == PF_INET)
#endif
{
/* Notify the device driver that send data is available */
netdev_ipv4_txnotify(conn->u.ipv4.laddr, conn->u.ipv4.raddr);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else /* if (psock->s_domain == PF_INET6) */
#endif /* CONFIG_NET_IPv4 */
{
/* Notify the device driver that send data is available */
DEBUGASSERT(psock->s_domain == PF_INET6);
netdev_ipv6_txnotify(conn->u.ipv6.laddr, conn->u.ipv6.raddr);
}
#endif /* CONFIG_NET_IPv6 */
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_tcp_send
*
* Description:
* psock_tcp_send() call may be used only when the TCP socket is in a
* connected state (so that the intended recipient is known).
*
* Input Parameters:
* psock An instance of the internal socket structure.
* buf Data to send
* len Length of data to send
*
* Returned Value:
* On success, returns the number of characters sent. On error,
* -1 is returned, and errno is set appropriately:
*
* EAGAIN or EWOULDBLOCK
* The socket is marked non-blocking and the requested operation
* would block.
* EBADF
* An invalid descriptor was specified.
* ECONNRESET
* Connection reset by peer.
* EDESTADDRREQ
* The socket is not connection-mode, and no peer address is set.
* EFAULT
* An invalid user space address was specified for a parameter.
* EINTR
* A signal occurred before any data was transmitted.
* EINVAL
* Invalid argument passed.
* EISCONN
* The connection-mode socket was connected already but a recipient
* was specified. (Now either this error is returned, or the recipient
* specification is ignored.)
* EMSGSIZE
* The socket type requires that message be sent atomically, and the
* size of the message to be sent made this impossible.
* ENOBUFS
* The output queue for a network interface was full. This generally
* indicates that the interface has stopped sending, but may be
* caused by transient congestion.
* ENOMEM
* No memory available.
* ENOTCONN
* The socket is not connected, and no target has been given.
* ENOTSOCK
* The argument s is not a socket.
* EPIPE
* The local end has been shut down on a connection oriented socket.
* In this case the process will also receive a SIGPIPE unless
* MSG_NOSIGNAL is set.
*
****************************************************************************/
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_wrbuffer_s *wrb;
ssize_t result = 0;
int ret = OK;
if (psock == NULL || psock->s_crefs <= 0)
{
nerr("ERROR: Invalid socket\n");
ret = -EBADF;
goto errout;
}
if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
{
nerr("ERROR: Not connected\n");
ret = -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)
{
nerr("ERROR: Not reachable\n");
ret = -ENETUNREACH;
goto errout;
}
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */
/* Dump the incoming buffer */
BUF_DUMP("psock_tcp_send", buf, len);
/* Set the socket state to sending */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND);
if (len > 0)
{
/* Allocate a write buffer. Careful, the network will be momentarily
* unlocked here.
*/
net_lock();
if (_SS_ISNONBLOCK(psock->s_flags))
{
wrb = tcp_wrbuffer_tryalloc();
}
else
{
wrb = tcp_wrbuffer_alloc();
}
if (wrb == NULL)
{
/* A buffer allocation error occurred */
nerr("ERROR: Failed to allocate write buffer\n");
ret = _SS_ISNONBLOCK(psock->s_flags) ? -EAGAIN : -ENOMEM;
goto errout_with_lock;
}
/* Allocate resources to receive a callback */
if (psock->s_sndcb == NULL)
{
psock->s_sndcb = tcp_callback_alloc(conn);
}
/* Test if the callback has been allocated */
if (psock->s_sndcb == NULL)
{
/* A buffer allocation error occurred */
nerr("ERROR: Failed to allocate callback\n");
ret = _SS_ISNONBLOCK(psock->s_flags) ? -EAGAIN : -ENOMEM;
goto errout_with_wrb;
}
/* Set up the callback in the connection */
psock->s_sndcb->flags = (TCP_ACKDATA | TCP_REXMIT | TCP_POLL |
TCP_DISCONN_EVENTS);
psock->s_sndcb->priv = (FAR void *)psock;
psock->s_sndcb->event = psock_send_eventhandler;
/* Initialize the write buffer */
TCP_WBSEQNO(wrb) = (unsigned)-1;
TCP_WBNRTX(wrb) = 0;
/* Copy the user data into the write buffer. We cannot wait for
* buffer space if the socket was opened non-blocking.
*/
if (_SS_ISNONBLOCK(psock->s_flags))
{
/* The return value from TCP_WBTRYCOPYIN is either OK or
* -ENOMEM if less than the entire data chunk could be allocated.
* If -ENOMEM is returned, check if at least a part of the data
* chunk was allocated. If more than zero bytes were sent
* we return that number and let the caller deal with sending the
* remaining data.
*/
result = TCP_WBTRYCOPYIN(wrb, (FAR uint8_t *)buf, len);
if (result == -ENOMEM)
{
if (TCP_WBPKTLEN(wrb) > 0)
{
ninfo("INFO: Allocated part of the requested data\n");
result = TCP_WBPKTLEN(wrb);
}
else
{
nerr("ERROR: Failed to add data to the I/O buffer chain\n");
ret = -EWOULDBLOCK;
goto errout_with_wrb;
}
}
else
{
result = len;
}
}
else
{
result = TCP_WBCOPYIN(wrb, (FAR uint8_t *)buf, len);
}
/* Dump I/O buffer chain */
TCP_WBDUMP("I/O buffer chain", wrb, TCP_WBPKTLEN(wrb), 0);
/* psock_send_eventhandler() will send data in FIFO order from the
* conn->write_q
*/
sq_addlast(&wrb->wb_node, &conn->write_q);
ninfo("Queued WRB=%p pktlen=%u write_q(%p,%p)\n",
wrb, TCP_WBPKTLEN(wrb),
conn->write_q.head, conn->write_q.tail);
/* Notify the device driver of the availability of TX data */
send_txnotify(psock, conn);
net_unlock();
}
/* Set the socket state to idle */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);
/* Check for errors. Errors are signaled by negative errno values
* for the send length
*/
if (result < 0)
{
ret = result;
goto errout;
}
if (ret < 0)
{
goto errout;
}
/* Return the number of bytes actually sent */
return result;
errout_with_wrb:
tcp_wrbuffer_release(wrb);
errout_with_lock:
net_unlock();
errout:
return ret;
}
/****************************************************************************
* Name: psock_tcp_cansend
*
* Description:
* psock_tcp_cansend() returns a value indicating if a write to the socket
* would block. No space in the buffer is actually reserved, so it is
* possible that the write may still block if the buffer is filled by
* another means.
*
* Input Parameters:
* psock An instance of the internal socket structure.
*
* Returned Value:
* OK
* At least one byte of data could be succesfully written.
* -EWOULDBLOCK
* There is no room in the output buffer.
* -EBADF
* An invalid descriptor was specified.
* -ENOTCONN
* The socket is not connected.
*
****************************************************************************/
int psock_tcp_cansend(FAR struct socket *psock)
{
if (!psock || psock->s_crefs <= 0)
{
nerr("ERROR: Invalid socket\n");
return -EBADF;
}
if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
{
nerr("ERROR: Not connected\n");
return -ENOTCONN;
}
if (tcp_wrbuffer_test() < 0)
{
return -EWOULDBLOCK;
}
return OK;
}
#endif /* CONFIG_NET && CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */