root/webserver/example/freeRTOS/Demo/Common/ethernet/uIP/uip-1.0/uip/uip-split.c

Revision 14, 4.7 kB (checked in by phil, 15 years ago)

added unmodified FreeRTOS package V5.4.1 with only web srv demo source for LPC2368 for CrossWorks?

Line 
1 /*
2  * Copyright (c) 2004, Swedish Institute of Computer Science.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the Institute nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * This file is part of the uIP TCP/IP stack
30  *
31  * Author: Adam Dunkels <adam@sics.se>
32  *
33  * $Id: uip-split.c,v 1.2 2006/06/12 08:00:30 adam Exp $
34  */
35
36 #include <string.h>
37
38 #include "uip-split.h"
39 #include "uip.h"
40 #include "uip-fw.h"
41 #include "uip_arch.h"
42
43
44
45 #define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
46
47 /*-----------------------------------------------------------------------------*/
48 void
49 uip_split_output(void)
50 {
51   u16_t tcplen, len1, len2;
52
53   /* We only try to split maximum sized TCP segments. */
54   if(BUF->proto == UIP_PROTO_TCP &&
55      uip_len == UIP_BUFSIZE - UIP_LLH_LEN) {
56
57     tcplen = uip_len - UIP_TCPIP_HLEN;
58     /* Split the segment in two. If the original packet length was
59        odd, we make the second packet one byte larger. */
60     len1 = len2 = tcplen / 2;
61     if(len1 + len2 < tcplen) {
62       ++len2;
63     }
64
65     /* Create the first packet. This is done by altering the length
66        field of the IP header and updating the checksums. */
67     uip_len = len1 + UIP_TCPIP_HLEN;
68 #if UIP_CONF_IPV6
69     /* For IPv6, the IP length field does not include the IPv6 IP header
70        length. */
71     BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
72     BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
73 #else /* UIP_CONF_IPV6 */
74     BUF->len[0] = uip_len >> 8;
75     BUF->len[1] = uip_len & 0xff;
76 #endif /* UIP_CONF_IPV6 */
77    
78     /* Recalculate the TCP checksum. */
79     BUF->tcpchksum = 0;
80     BUF->tcpchksum = ~(uip_tcpchksum());
81
82 #if !UIP_CONF_IPV6
83     /* Recalculate the IP checksum. */
84     BUF->ipchksum = 0;
85     BUF->ipchksum = ~(uip_ipchksum());
86 #endif /* UIP_CONF_IPV6 */
87    
88     /* Transmit the first packet. */
89     /*    uip_fw_output();*/
90     tcpip_output();
91
92     /* Now, create the second packet. To do this, it is not enough to
93        just alter the length field, but we must also update the TCP
94        sequence number and point the uip_appdata to a new place in
95        memory. This place is detemined by the length of the first
96        packet (len1). */
97     uip_len = len2 + UIP_TCPIP_HLEN;
98 #if UIP_CONF_IPV6
99     /* For IPv6, the IP length field does not include the IPv6 IP header
100        length. */
101     BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
102     BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
103 #else /* UIP_CONF_IPV6 */
104     BUF->len[0] = uip_len >> 8;
105     BUF->len[1] = uip_len & 0xff;
106 #endif /* UIP_CONF_IPV6 */
107    
108     /*    uip_appdata += len1;*/
109     memcpy(uip_appdata, (u8_t *)uip_appdata + len1, len2);
110
111     uip_add32(BUF->seqno, len1);
112     BUF->seqno[0] = uip_acc32[0];
113     BUF->seqno[1] = uip_acc32[1];
114     BUF->seqno[2] = uip_acc32[2];
115     BUF->seqno[3] = uip_acc32[3];
116    
117     /* Recalculate the TCP checksum. */
118     BUF->tcpchksum = 0;
119     BUF->tcpchksum = ~(uip_tcpchksum());
120
121 #if !UIP_CONF_IPV6
122     /* Recalculate the IP checksum. */
123     BUF->ipchksum = 0;
124     BUF->ipchksum = ~(uip_ipchksum());
125 #endif /* UIP_CONF_IPV6 */
126
127     /* Transmit the second packet. */
128     /*    uip_fw_output();*/
129     tcpip_output();
130   } else {
131     /*    uip_fw_output();*/
132     tcpip_output();
133   }
134      
135 }
136 /*-----------------------------------------------------------------------------*/
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