/* * 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 Contiki operating system. * * Author: Adam Dunkels * * $Id: uip-split.c,v 1.2 2008/10/14 13:39:12 julienabeille Exp $ */ #include "uip-split.h" #define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN]) /*-----------------------------------------------------------------------------*/ void uip_split_output(void) { #if UIP_TCP u16_t tcplen, len1, len2; /* We only try to split maximum sized TCP segments. */ if(BUF->proto == UIP_PROTO_TCP && uip_len == UIP_BUFSIZE) { tcplen = uip_len - UIP_TCPIP_HLEN - UIP_LLH_LEN; /* 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 + UIP_LLH_LEN; #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 - UIP_LLH_LEN) >> 8; BUF->len[1] = (uip_len - UIP_LLH_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. */ #if UIP_CONF_IPV6 tcpip_ipv6_output(); #else if (USB_CurrentMode == USB_MODE_Device) RNDIS_Device_SendPacket(&Ethernet_RNDIS_Interface_Device, uip_buf, uip_len); else RNDIS_Host_SendPacket(&Ethernet_RNDIS_Interface_Host, uip_buf, uip_len); #endif /* UIP_CONF_IPV6 */ /* 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 determined by the length of the first packet (len1). */ uip_len = len2 + UIP_TCPIP_HLEN + UIP_LLH_LEN; #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 - UIP_LLH_LEN) >> 8; BUF->len[1] = (uip_len - UIP_LLH_LEN) & 0xff; #endif /* UIP_CONF_IPV6 */ 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. */ #if UIP_CONF_IPV6 tcpip_ipv6_output(); #else if (USB_CurrentMode == USB_MODE_Device) RNDIS_Device_SendPacket(&Ethernet_RNDIS_Interface_Device, uip_buf, uip_len); else RNDIS_Host_SendPacket(&Ethernet_RNDIS_Interface_Host, uip_buf, uip_len); #endif /* UIP_CONF_IPV6 */ return; } #endif /* UIP_TCP */ /* uip_fw_output();*/ #if UIP_CONF_IPV6 tcpip_ipv6_output(); #else if (USB_CurrentMode == USB_MODE_Device) RNDIS_Device_SendPacket(&Ethernet_RNDIS_Interface_Device, uip_buf, uip_len); else RNDIS_Host_SendPacket(&Ethernet_RNDIS_Interface_Host, uip_buf, uip_len); #endif /* UIP_CONF_IPV6 */ } /*-----------------------------------------------------------------------------*/ ='n57' href='#n57'>57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167