123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302 |
- /****************************************************************************
- * net/tcp/tcp_callback.c
- *
- * Copyright (C) 2007-2009, 2014, 2017 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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>
- #include <stdint.h>
- #include <string.h>
- #include <debug.h>
- #include <nuttx/mm/iob.h>
- #include <nuttx/net/netconfig.h>
- #include <nuttx/net/netdev.h>
- #include <nuttx/net/netstats.h>
- #include "devif/devif.h"
- #include "tcp/tcp.h"
- #ifdef NET_TCP_HAVE_STACK
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: tcp_data_event
- *
- * Description:
- * Handle data that is not accepted by the application because there is no
- * listener in place ready to receive the data.
- *
- * Assumptions:
- * - The caller has checked that TCP_NEWDATA is set in flags and that is no
- * other handler available to process the incoming data.
- * - This function must be called with the network locked.
- *
- ****************************************************************************/
- static inline uint16_t
- tcp_data_event(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn,
- uint16_t flags)
- {
- uint16_t ret;
- /* Assume that we will ACK the data. The data will be ACKed if it is
- * placed in the read-ahead buffer -OR- if it zero length
- */
- ret = (flags & ~TCP_NEWDATA) | TCP_SNDACK;
- /* Is there new data? With non-zero length? (Certain connection events
- * can have zero-length with TCP_NEWDATA set just to cause an ACK).
- */
- if (dev->d_len > 0)
- {
- #ifdef CONFIG_NET_TCP_READAHEAD
- uint8_t *buffer = dev->d_appdata;
- int buflen = dev->d_len;
- uint16_t recvlen;
- #endif
- ninfo("No listener on connection\n");
- #ifdef CONFIG_NET_TCP_READAHEAD
- /* Save as the packet data as in the read-ahead buffer. NOTE that
- * partial packets will not be buffered.
- */
- recvlen = tcp_datahandler(conn, buffer, buflen);
- if (recvlen < buflen)
- #endif
- {
- /* There is no handler to receive new data and there are no free
- * read-ahead buffers to retain the data -- drop the packet.
- */
- ninfo("Dropped %d bytes\n", dev->d_len);
- #ifdef CONFIG_NET_STATISTICS
- g_netstats.tcp.drop++;
- #endif
- /* Clear the TCP_SNDACK bit so that no ACK will be sent */
- ret &= ~TCP_SNDACK;
- }
- }
- /* In any event, the new data has now been handled */
- dev->d_len = 0;
- return ret;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: tcp_callback
- *
- * Description:
- * Inform the application holding the TCP socket of a change in state.
- *
- * Assumptions:
- * This function must be called with the network locked.
- *
- ****************************************************************************/
- uint16_t tcp_callback(FAR struct net_driver_s *dev,
- FAR struct tcp_conn_s *conn, uint16_t flags)
- {
- #ifdef CONFIG_TCP_NOTIFIER
- uint16_t orig = flags;
- #endif
- /* Preserve the TCP_ACKDATA, TCP_CLOSE, and TCP_ABORT in the response.
- * These is needed by the network to handle responses and buffer state. The
- * TCP_NEWDATA indication will trigger the ACK response, but must be
- * explicitly set in the callback.
- */
- ninfo("flags: %04x\n", flags);
- /* Perform the data callback. When a data callback is executed from 'list',
- * the input flags are normally returned, however, the implementation
- * may set one of the following:
- *
- * TCP_CLOSE - Gracefully close the current connection
- * TCP_ABORT - Abort (reset) the current connection on an error that
- * prevents TCP_CLOSE from working.
- *
- * And/Or set/clear the following:
- *
- * TCP_NEWDATA - May be cleared to indicate that the data was consumed
- * and that no further process of the new data should be
- * attempted.
- * TCP_SNDACK - If TCP_NEWDATA is cleared, then TCP_SNDACK may be set
- * to indicate that an ACK should be included in the
- * response. (In TCP_NEWDATA is cleared but TCP_SNDACK is
- * not set, then dev->d_len should also be cleared).
- */
- flags = devif_conn_event(dev, conn, flags, conn->list);
- /* There may be no new data handler in place at them moment that the new
- * incoming data is received. If the new incoming data was not handled, then
- * either (1) put the unhandled incoming data in the read-ahead buffer (if
- * enabled) or (2) suppress the ACK to the data in the hope that it will
- * be re-transmitted at a better time.
- */
- if ((flags & TCP_NEWDATA) != 0)
- {
- /* Data was not handled.. dispose of it appropriately */
- flags = tcp_data_event(dev, conn, flags);
- }
- /* Check if there is a connection-related event and a connection
- * callback.
- */
- if ((flags & TCP_CONN_EVENTS) != 0)
- {
- /* Perform the callback disconnect callbacks */
- flags = devif_conn_event(dev, conn, flags, conn->connevents);
- }
- #ifdef CONFIG_TCP_NOTIFIER
- /* Provide notification(s) if the TCP connection has been lost. */
- if ((orig & TCP_DISCONN_EVENTS) != 0)
- {
- tcp_disconnect_signal(conn);
- }
- #endif
- return flags;
- }
- /****************************************************************************
- * Name: tcp_datahandler
- *
- * Description:
- * Handle data that is not accepted by the application. This may be called
- * either (1) from the data receive logic if it cannot buffer the data, or
- * (2) from the TCP event logic is there is no listener in place ready to
- * receive the data.
- *
- * Input Parameters:
- * conn - A pointer to the TCP connection structure
- * buffer - A pointer to the buffer to be copied to the read-ahead
- * buffers
- * buflen - The number of bytes to copy to the read-ahead buffer.
- *
- * Returned Value:
- * The number of bytes actually buffered is returned. This will be either
- * zero or equal to buflen; partial packets are not buffered.
- *
- * Assumptions:
- * - The caller has checked that TCP_NEWDATA is set in flags and that is no
- * other handler available to process the incoming data.
- * - This function must be called with the network locked.
- *
- ****************************************************************************/
- #ifdef CONFIG_NET_TCP_READAHEAD
- uint16_t tcp_datahandler(FAR struct tcp_conn_s *conn, FAR uint8_t *buffer,
- uint16_t buflen)
- {
- FAR struct iob_s *iob;
- int ret;
- /* Try to allocate on I/O buffer to start the chain without waiting (and
- * throttling as necessary). If we would have to wait, then drop the
- * packet.
- */
- iob = iob_tryalloc(true);
- if (iob == NULL)
- {
- nerr("ERROR: Failed to create new I/O buffer chain\n");
- return 0;
- }
- /* Copy the new appdata into the I/O buffer chain (without waiting) */
- ret = iob_trycopyin(iob, buffer, buflen, 0, true);
- if (ret < 0)
- {
- /* On a failure, iob_copyin 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 (again
- * without waiting).
- */
- 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_TCP_NOTIFIER
- /* Provide notification(s) that additional TCP read-ahead data is
- * available.
- */
- tcp_readahead_signal(conn);
- #endif
- ninfo("Buffered %d bytes\n", buflen);
- return buflen;
- }
- #endif /* CONFIG_NET_TCP_READAHEAD */
- #endif /* NET_TCP_HAVE_STACK */
|