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https://opencores.org/ocsvn/openrisc_2011-10-31/openrisc_2011-10-31/trunk
Subversion Repositories openrisc_2011-10-31
[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [ethernet/] [FreeRTOS-uIP/] [uip-split.c] - Rev 649
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/* * Copyright (c) 2004, Swedish Institute of Computer Science. * All rights reserved. * * 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 of the Institute 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 INSTITUTE 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 INSTITUTE 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. * * This file is part of the uIP TCP/IP stack * * Author: Adam Dunkels <adam@sics.se> * * $Id: uip-split.c 2 2011-07-17 20:13:17Z filepang@gmail.com $ */ #include <string.h> #include "uip-split.h" #include "uip.h" #include "uip-fw.h" #include "uip_arch.h" #define BUF ( ( struct uip_tcpip_hdr * ) &uip_buf[UIP_LLH_LEN] ) /*-----------------------------------------------------------------------------*/ void uip_split_output( void ) { u16_t tcplen, len1, len2; /* We only try to split maximum sized TCP segments. */ if( BUF->proto == UIP_PROTO_TCP && uip_len == UIP_BUFSIZE - UIP_LLH_LEN ) { tcplen = uip_len - UIP_TCPIP_HLEN; /* Split the segment in two. If the original packet length was odd, we make the second packet one byte larger. */ len1 = len2 = tcplen / 2; if( len1 + len2 < tcplen ) { ++len2; } /* Create the first packet. This is done by altering the length field of the IP header and updating the checksums. */ uip_len = len1 + UIP_TCPIP_HLEN; #if UIP_CONF_IPV6 /* For IPv6, the IP length field does not include the IPv6 IP header length. */ BUF->len[0] = ( (uip_len - UIP_IPH_LEN) >> 8 ); BUF->len[1] = ( (uip_len - UIP_IPH_LEN) & 0xff ); #else /* UIP_CONF_IPV6 */ BUF->len[0] = uip_len >> 8; BUF->len[1] = uip_len & 0xff; #endif /* UIP_CONF_IPV6 */ /* Recalculate the TCP checksum. */ BUF->tcpchksum = 0; BUF->tcpchksum = ~( uip_tcpchksum() ); #if !UIP_CONF_IPV6 /* Recalculate the IP checksum. */ BUF->ipchksum = 0; BUF->ipchksum = ~( uip_ipchksum() ); #endif /* UIP_CONF_IPV6 */ /* Transmit the first packet. */ /* uip_fw_output();*/ // tcpip_output(); /* Now, create the second packet. To do this, it is not enough to just alter the length field, but we must also update the TCP sequence number and point the uip_appdata to a new place in memory. This place is detemined by the length of the first packet (len1). */ uip_len = len2 + UIP_TCPIP_HLEN; #if UIP_CONF_IPV6 /* For IPv6, the IP length field does not include the IPv6 IP header length. */ BUF->len[0] = ( (uip_len - UIP_IPH_LEN) >> 8 ); BUF->len[1] = ( (uip_len - UIP_IPH_LEN) & 0xff ); #else /* UIP_CONF_IPV6 */ BUF->len[0] = uip_len >> 8; BUF->len[1] = uip_len & 0xff; #endif /* UIP_CONF_IPV6 */ /* uip_appdata += len1;*/ memcpy( uip_appdata, ( u8_t * ) uip_appdata + len1, len2 ); uip_add32( BUF->seqno, len1 ); BUF->seqno[0] = uip_acc32[0]; BUF->seqno[1] = uip_acc32[1]; BUF->seqno[2] = uip_acc32[2]; BUF->seqno[3] = uip_acc32[3]; /* Recalculate the TCP checksum. */ BUF->tcpchksum = 0; BUF->tcpchksum = ~( uip_tcpchksum() ); #if !UIP_CONF_IPV6 /* Recalculate the IP checksum. */ BUF->ipchksum = 0; BUF->ipchksum = ~( uip_ipchksum() ); #endif /* UIP_CONF_IPV6 */ /* Transmit the second packet. */ /* uip_fw_output();*/ // tcpip_output(); } else { /* uip_fw_output();*/ // tcpip_output(); } } /*-----------------------------------------------------------------------------*/
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