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Diffstat (limited to 'nuttx/net/uip/uip_tcpcallback.c')
| -rw-r--r-- | nuttx/net/uip/uip_tcpcallback.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/nuttx/net/uip/uip_tcpcallback.c b/nuttx/net/uip/uip_tcpcallback.c new file mode 100644 index 000000000..9ce8eb132 --- /dev/null +++ b/nuttx/net/uip/uip_tcpcallback.c @@ -0,0 +1,339 @@ +/**************************************************************************** + * net/uip/uip_tcpcallback.c + * + * Copyright (C) 2007-2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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) + +#include <stdint.h> +#include <string.h> +#include <debug.h> + +#include <nuttx/net/uip/uipopt.h> +#include <nuttx/net/uip/uip.h> +#include <nuttx/net/uip/uip-arch.h> + +#include "uip_internal.h" + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Function: uip_readahead + * + * Description: + * Copy as much received data as possible into the readahead buffer + * + * Assumptions: + * This function is called at the interrupt level with interrupts disabled. + * + ****************************************************************************/ + +#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 +static int uip_readahead(struct uip_readahead_s *readahead, uint8_t *buf, + int len) +{ + int available = CONFIG_NET_TCP_READAHEAD_BUFSIZE - readahead->rh_nbytes; + int recvlen = 0; + + if (len > 0 && available > 0) + { + /* Get the length of the data to buffer. */ + + if (len > available) + { + recvlen = available; + } + else + { + recvlen = len; + } + + /* Copy the new appdata into the read-ahead buffer */ + + memcpy(&readahead->rh_buffer[readahead->rh_nbytes], buf, recvlen); + readahead->rh_nbytes += recvlen; + } + return recvlen; +} +#endif + +/**************************************************************************** + * Function: uip_dataevent + * + * 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 UIP_NEWDATA is set in flags and that is no + * other handler available to process the incoming data. + * - This function is called at the interrupt level with interrupts disabled. + * + ****************************************************************************/ + +static inline uint16_t +uip_dataevent(FAR struct uip_driver_s *dev, FAR struct uip_conn *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 & ~UIP_NEWDATA) | UIP_SNDACK; + + /* Is there new data? With non-zero length? (Certain connection events + * can have zero-length with UIP_NEWDATA set just to cause an ACK). + */ + + if (dev->d_len > 0) + { +#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 + uint8_t *buffer = dev->d_appdata; + int buflen = dev->d_len; + uint16_t recvlen; +#endif + + nllvdbg("No listener on connection\n"); + +#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 + /* Save as much data as possible in the read-ahead buffers */ + + recvlen = uip_datahandler(conn, buffer, buflen); + + /* There are several complicated buffering issues that are not addressed + * properly here. For example, what if we cannot buffer the entire + * packet? In that case, some data will be accepted but not ACKed. + * Therefore it will be resent and duplicated. Fixing this could be tricky. + */ + + 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. + */ + + nllvdbg("Dropped %d bytes\n", dev->d_len); + + #ifdef CONFIG_NET_STATISTICS + uip_stat.tcp.syndrop++; + uip_stat.tcp.drop++; +#endif + /* Clear the UIP_SNDACK bit so that no ACK will be sent */ + + ret &= ~UIP_SNDACK; + } + } + + /* In any event, the new data has now been handled */ + + dev->d_len = 0; + return ret; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Function: uip_tcpcallback + * + * Description: + * Inform the application holding the TCP socket of a change in state. + * + * Assumptions: + * This function is called at the interrupt level with interrupts disabled. + * + ****************************************************************************/ + +uint16_t uip_tcpcallback(struct uip_driver_s *dev, struct uip_conn *conn, + uint16_t flags) +{ + /* Preserve the UIP_ACKDATA, UIP_CLOSE, and UIP_ABORT in the response. + * These is needed by uIP to handle responses and buffer state. The + * UIP_NEWDATA indication will trigger the ACK response, but must be + * explicitly set in the callback. + */ + + uint16_t ret = flags; + + nllvdbg("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: + * + * UIP_CLOSE - Gracefully close the current connection + * UIP_ABORT - Abort (reset) the current connection on an error that + * prevents UIP_CLOSE from working. + * + * And/Or set/clear the following: + * + * UIP_NEWDATA - May be cleared to indicate that the data was consumed + * and that no further process of the new data should be + * attempted. + * UIP_SNDACK - If UIP_NEWDATA is cleared, then UIP_SNDACK may be set + * to indicate that an ACK should be included in the response. + * (In UIP_NEWDATA is cleared bu UIP_SNDACK is not set, then + * dev->d_len should also be cleared). + */ + + ret = uip_callbackexecute(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 ((ret & UIP_NEWDATA) != 0) + { + /* Data was not handled.. dispose of it appropriately */ + + ret = uip_dataevent(dev, conn, ret); + } + + /* Check if there is a connection-related event and a connection + * callback. + */ + + if (((flags & UIP_CONN_EVENTS) != 0) && conn->connection_event) + { + /* Perform the callback */ + + conn->connection_event(conn, flags); + } + + return ret; +} + +/**************************************************************************** + * Function: uip_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 Parmeters: + * 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. This could be less than 'nbytes' + * if there is insufficient buffering available. + * + * Assumptions: + * - The caller has checked that UIP_NEWDATA is set in flags and that is no + * other handler available to process the incoming data. + * - This function is called at the interrupt level with interrupts disabled. + * + ****************************************************************************/ + +#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 +uint16_t uip_datahandler(FAR struct uip_conn *conn, FAR uint8_t *buffer, + uint16_t buflen) +{ + FAR struct uip_readahead_s *readahead1; + FAR struct uip_readahead_s *readahead2 = NULL; + uint16_t remaining; + uint16_t recvlen = 0; + + /* First, we need to determine if we have space to buffer the data. This + * needs to be verified before we actually begin buffering the data. We + * will use any remaining space in the last allocated readahead buffer + * plus as much one additional buffer. It is expected that the size of + * readahead buffers are tuned so that one full packet will always fit + * into one readahead buffer (for example if the buffer size is 420, then + * a readahead buffer of 366 will hold a full packet of TCP data). + */ + + readahead1 = (FAR struct uip_readahead_s*)conn->readahead.tail; + if ((readahead1 && + (CONFIG_NET_TCP_READAHEAD_BUFSIZE - readahead1->rh_nbytes) > buflen) || + (readahead2 = uip_tcpreadaheadalloc()) != NULL) + { + /* We have buffer space. Now try to append add as much data as possible + * to the last readahead buffer attached to this connection. + */ + + remaining = buflen; + if (readahead1) + { + recvlen = uip_readahead(readahead1, buffer, remaining); + if (recvlen > 0) + { + buffer += recvlen; + remaining -= recvlen; + } + } + + /* Do we need to buffer into the newly allocated buffer as well? */ + + if (readahead2) + { + readahead2->rh_nbytes = 0; + recvlen += uip_readahead(readahead2, buffer, remaining); + + /* Save the readahead buffer in the connection structure where + * it can be found with recv() is called. + */ + + sq_addlast(&readahead2->rh_node, &conn->readahead); + } + } + + nllvdbg("Buffered %d bytes (of %d)\n", recvlen, buflen); + return recvlen; +} +#endif /* CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 */ + +#endif /* CONFIG_NET && CONFIG_NET_TCP */ |