/****************************************************************************
* net/net_send_buffered.c
*
* Copyright (C) 2007-2014 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)
#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/uip/uip-arp.h>
#include <nuttx/net/uip/uip-arch.h>
#ifdef CONFIG_NET_ARP_IPIN
# include <nuttx/net/uip/uip-arp.h>
#endif
#include "net_internal.h"
#include "uip/uip_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define TCPBUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Function: send_insert_seqment
*
* Description:
* Insert a new segment in a write buffer queue, keep the segment queue in
* ascending order of sequence number.
*
* Parameters:
* segment The segment to be inserted
* q The write buffer queue in which to insert the segment
*
* Returned Value:
* None
*
* Assumptions:
* Running at the interrupt level
*
****************************************************************************/
static void send_insert_seqment(FAR struct uip_wrbuffer_s *segment,
FAR sq_queue_t *q)
{
sq_entry_t *entry = (sq_entry_t*)segment;
sq_entry_t *insert = NULL;
sq_entry_t *itr;
for (itr = sq_peek(q); itr; itr = sq_next(itr))
{
FAR struct uip_wrbuffer_s *segment0 = (FAR struct uip_wrbuffer_s*)itr;
if (segment0->wb_seqno < segment->wb_seqno)
{
insert = itr;
}
else
{
break;
}
}
if (insert)
{
sq_addafter(insert, entry, q);
}
else
{
sq_addfirst(entry, q);
}
}
/****************************************************************************
* Function: send_interrupt
*
* Description:
* This function is called from the interrupt level to perform the actual
* send operation when polled by the uIP layer.
*
* Parameters:
* dev The structure of the network driver that caused the interrupt
* conn The connection structure associated with the socket
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* Running at the interrupt level
*
****************************************************************************/
static uint16_t send_interrupt(FAR struct uip_driver_s *dev, FAR void *pvconn,
FAR void *pvpriv, uint16_t flags)
{
FAR struct uip_conn *conn = (FAR struct uip_conn*)pvconn;
FAR struct socket *psock = (FAR struct socket *)pvpriv;
nllvdbg("flags: %04x\n", flags);
/* If this packet contains an acknowledgement, then update the count of
* acknowledged bytes.
*/
if ((flags & UIP_ACKDATA) != 0)
{
FAR sq_entry_t *entry, *next;
FAR struct uip_wrbuffer_s *segment;
uint32_t ackno;
ackno = uip_tcpgetsequence(TCPBUF->ackno);
for (entry = sq_peek(&conn->unacked_q); entry; entry = next)
{
next = sq_next(entry);
segment = (FAR struct uip_wrbuffer_s*)entry;
if (segment->wb_seqno < ackno)
{
nllvdbg("ACK: acked=%d buflen=%d ackno=%d\n",
segment->wb_seqno, segment->wb_nbytes, ackno);
/* Segment was ACKed. Remove from ACK waiting queue */
sq_rem(entry, &conn->unacked_q);
/* Return the write buffer to the pool of free buffers */
uip_tcpwrbuffer_release(segment);
}
}
}
/* Check for a loss of connection */
else if ((flags & (UIP_CLOSE | UIP_ABORT | UIP_TIMEDOUT)) != 0)
{
/* Report not connected */
nllvdbg("Lost connection\n");
net_lostconnection(psock, flags);
goto end_wait;
}
/* Check if we are being asked to retransmit data */
else if ((flags & UIP_REXMIT) != 0)
{
sq_entry_t *entry;
/* Put all segments that have been sent but not ACKed to write queue
* again note, the un-ACKed segment is put at the first of the write_q,
* so it can be sent as soon as possible.
*/
while ((entry = sq_remlast(&conn->unacked_q)))
{
struct uip_wrbuffer_s *segment = (struct uip_wrbuffer_s*)entry;
if (segment->wb_nrtx >= UIP_MAXRTX)
{
//conn->unacked -= segment->wb_nbytes;
/* Return the write buffer */
uip_tcpwrbuffer_release(segment);
/* NOTE expired is different from un-ACKed, it is designed to
* represent the number of segments that have been sent,
* retransmitted, and un-ACKed, if expired is not zero, the
* connection will be closed.
*
* field expired can only be updated at UIP_ESTABLISHED state
*/
conn->expired++;
continue;
}
send_insert_seqment(segment, &conn->write_q);
}
}
/* Check if the outgoing packet is available (it may have been claimed
* by a sendto interrupt serving a different thread).
*/
if (dev->d_sndlen > 0)
{
/* Another thread has beat us sending data, wait for the next poll */
return flags;
}
/* We get here if (1) not all of the data has been ACKed, (2) we have been
* asked to retransmit data, (3) the connection is still healthy, and (4)
* the outgoing packet is available for our use. In this case, we are
* now free to send more data to receiver -- UNLESS the buffer contains
* unprocesed incoming data. In that event, we will have to wait for the
* next polling cycle.
*/
if ((conn->tcpstateflags & UIP_ESTABLISHED) &&
(flags & (UIP_POLL | UIP_REXMIT)) &&
!(sq_empty(&conn->write_q)))
{
/* Check if the destination IP address is in the ARP table. If not,
* then the send won't actually make it out... it will be replaced with
* an ARP request.
*
* NOTE 1: This could be an expensive check if there are a lot of
* entries in the ARP table.
*
* NOTE 2: If we are actually harvesting IP addresses on incoming IP
* packets, then this check should not be necessary; the MAC mapping
* should already be in the ARP table.
*/
#if defined(CONFIG_NET_ETHERNET) && !defined(CONFIG_NET_ARP_IPIN)
if (uip_arp_find(conn->ripaddr) != NULL)
#endif
{
FAR struct uip_wrbuffer_s *segment;
FAR void *sndbuf;
size_t sndlen;
/* Get the amount of data that we can send in the next packet */
segment = (FAR struct uip_wrbuffer_s *)sq_remfirst(&conn->write_q);
if (segment)
{
sndbuf = segment->wb_buffer;
sndlen = segment->wb_nbytes;
DEBUGASSERT(sndlen <= uip_mss(conn));
/* REVISIT: There should be a check here to assure that we do
* not excced the window (conn->winsize).
*/
/* Set the sequence number for this segment. NOTE: uIP
* updates sndseq on receipt of ACK *before* this function
* is called. In that case sndseq will point to the next
* unacknowledged byte (which might have already been
* sent). We will overwrite the value of sndseq here
* before the packet is sent.
*/
if (segment->wb_nrtx == 0 && segment->wb_seqno == (unsigned)-1)
{
segment->wb_seqno = conn->isn + conn->sent;
}
uip_tcpsetsequence(conn->sndseq, segment->wb_seqno);
/* Then set-up to send that amount of data. (this won't
* actually happen until the polling cycle completes).
*/
uip_send(dev, sndbuf, sndlen);
/* Remember how much data we send out now so that we know
* when everything has been acknowledged. Just increment
* the amount of data sent. This will be needed in
* sequence* number calculations and we know that this is
* not a re-transmission. Re-transmissions do not go through
* this path.
*/
if (segment->wb_nrtx == 0)
{
conn->unacked += sndlen;
conn->sent += sndlen;
}
/* Increment the retransmission counter before expiration.
* NOTE we will not calculate the retransmission timer
* (RTT) to save cpu cycles, each send_insert_seqment
* segment will be retransmitted UIP_MAXRTX times in halt-
* second interval before expiration.
*/
segment->wb_nrtx++;
/* The segment is waiting for ACK again */
send_insert_seqment(segment, &conn->unacked_q);
/* Only one data can be sent by low level driver at once,
* tell the caller stop polling the other connection.
*/
flags &= ~UIP_POLL;
}
}
}
/* Continue waiting */
return flags;
end_wait:
/* Do not allow any further callbacks */
psock->s_sndcb->flags = 0;
psock->s_sndcb->event = NULL;
return flags;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: psock_send
*
* Description:
* The send() call may be used only when the socket is in a connected state
* (so that the intended recipient is known). The only difference between
* send() and write() is the presence of flags. With zero flags parameter,
* send() is equivalent to write(). Also, send(sockfd,buf,len,flags) is
* equivalent to sendto(sockfd,buf,len,flags,NULL,0).
*
* Parameters:
* psock An instance of the internal socket structure.
* buf Data to send
* len Length of data to send
* flags Send flags
*
* 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.
* EOPNOTSUPP
* Some bit in the flags argument is inappropriate for the socket
* type.
* 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.
*
* Assumptions:
*
****************************************************************************/
ssize_t psock_send(FAR struct socket *psock, FAR const void *buf, size_t len,
int flags)
{
uip_lock_t save;
size_t completed = 0;
int err;
int ret = OK;
if (!psock || psock->s_crefs <= 0)
{
err = EBADF;
goto errout;
}
if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
{
err = ENOTCONN;
goto errout;
}
/* Set the socket state to sending */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND);
save = uip_lock();
if (len > 0)
{
struct uip_conn *conn = (struct uip_conn*)psock->s_conn;
if (!psock->s_sndcb)
{
psock->s_sndcb = uip_tcpcallbackalloc(conn);
/* Set up the callback in the connection */
psock->s_sndcb->flags = (UIP_ACKDATA | UIP_REXMIT |UIP_POLL | \
UIP_CLOSE | UIP_ABORT | UIP_TIMEDOUT);
psock->s_sndcb->priv = (void*)psock;
psock->s_sndcb->event = send_interrupt;
}
/* Allocate resources to receive a callback */
while (completed < len)
{
FAR struct uip_wrbuffer_s *segment = uip_tcpwrbuffer_alloc(NULL);
if (segment)
{
size_t cnt;
segment->wb_seqno = (unsigned)-1;
segment->wb_nrtx = 0;
if (len - completed > CONFIG_NET_TCP_WRITE_BUFSIZE)
{
cnt = CONFIG_NET_TCP_WRITE_BUFSIZE;
}
else
{
cnt = len - completed;
}
segment->wb_nbytes = cnt;
memcpy(segment->wb_buffer, (char*)buf + completed, cnt);
completed += cnt;
/* send_interrupt() will refer to all the write buffer by
* conn->writebuff
*/
sq_addlast(&segment->wb_node, &conn->write_q);
/* Notify the device driver of the availability of TX data */
netdev_txnotify(conn->ripaddr);
}
}
}
uip_unlock(save);
/* Set the socket state to idle */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);
/* Check for a errors. Errors are signaled by negative errno values
* for the send length
*/
if (completed < 0)
{
err = completed;
goto errout;
}
/* If uip_lockedwait failed, then we were probably reawakened by a signal.
* In this case, uip_lockedwait will have set errno appropriately.
*/
if (ret < 0)
{
err = -ret;
goto errout;
}
/* Return the number of bytes actually sent */
return completed;
errout:
set_errno(err);
return ERROR;
}
#endif /* CONFIG_NET && CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */