/* | |
* 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,v 1.2 2006/06/12 08:00:30 adam Exp $ | |
*/ | |
#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(); | |
} | |
} | |
/*-----------------------------------------------------------------------------*/ |