ip.lst
来自「用c8051f340基于51单片机上网」· LST 代码 · 共 199 行
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199 行
C51 COMPILER V8.08 IP 11/04/2008 18:45:34 PAGE 1
C51 COMPILER V8.08, COMPILATION OF MODULE IP
OBJECT MODULE PLACED IN Ip.OBJ
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.exe Ip.c DB OE
line level source
1 //-----------------------------------------------------------------------------
2 // Copyright (c) 2002 Jim Brady
3 // Do not use commercially without author's permission
4 // Last revised August 2002
5 // Net IP.C
6 //
7 // This module is the IP layer
8 // Refer to RFC 791, 1122, and RFC 815 (fragmentation)
9 //-----------------------------------------------------------------------------
10 #include <string.h>
11 #include "C8051f340.h"
12 #include "global.h"
13 ///#include "net.h"
14 #include "cksum.h"
15 #include "arp.h"
16 #include "icmp.h"
17 #include "udp.h"
18 #include "tcp.h"
19 #include "ip.h"
20
21
22 extern UCHAR idata debug;
23 extern ULONG code my_ipaddr;
24 WAIT xdata wait;
25
26 //-----------------------------------------------------------------------------
27 // Exported Function Definitions
28 //-----------------------------------------------------------------------------
29 extern void CP220x_Send(MACADDRESS* pDestAddr, unsigned char* buffer, unsigned int buffer_length, unsigned
- int packet_type);
30 extern unsigned int CP220x_Receive(unsigned char* buffer, unsigned int buffer_length);
31
32 //------------------------------------------------------------------------
33 // This handles outgoing IP datagrams. It adds the 20 byte IP header
34 // and checksum then forwards the IP datagram to the Ethernet layer
35 // for sending. See "TCP/IP Illustrated, Volume 1" Sect 3.2
36 //------------------------------------------------------------------------
37 void ip_send(UCHAR xdata * outbuf, ULONG ipaddr, UCHAR proto_id, UINT len)
38 {
39 1 IP_HEADER xdata * ip;
40 1 UCHAR xdata * hwaddr;
41 1 static UINT ip_ident = 0;
42 1
43 1 ip = (IP_HEADER xdata *)(outbuf + 14);
44 1 ip->ver_len = 0x45; // IPv4 with 20 byte header
45 1 ip->type_of_service = 0;
46 1 ip->total_length = 20 + len;
47 1 ip->identifier = ip_ident++; // sequential identifier
48 1 ip->fragment_info = 0; // not fragmented
49 1 ip->time_to_live = 32; // max hops
50 1 ip->protocol_id = proto_id; // type of payload
51 1 ip->header_cksum = 0;
52 1 ip->source_ipaddr = my_ipaddr;
53 1
54 1 // Outgoing IP address
C51 COMPILER V8.08 IP 11/04/2008 18:45:34 PAGE 2
55 1 ip->dest_ipaddr = ipaddr;
56 1
57 1 // Compute and insert complement of checksum of ip header
58 1 // Outgoing ip header length is always 20 bytes
59 1 ip->header_cksum = ~cksum(outbuf + 14, 20);
60 1
61 1 // Use ARP to get hardware address to send this to
62 1 hwaddr = arp_resolve(ip->dest_ipaddr);
63 1
64 1 // Null means that the ARP resolver did not find the IP address
65 1 // in its cache so had to send an ARP request
66 1 if (hwaddr == NULL)
67 1 {
68 2 // Fill in the destination information so ehrn the ARP response
69 2 // arrives we can identify it and know what to do when we get it
70 2 wait.buf = outbuf;
71 2 wait.ipaddr = ip->dest_ipaddr;
72 2 wait.proto_id = proto_id;
73 2 wait.len = len;
74 2 wait.timer = ARP_TIMEOUT;
75 2 return;
76 2 }
77 1
78 1 ///eth_send(outbuf, hwaddr, IP_PACKET, 20 + len);
79 1 CP220x_Send(hwaddr , outbuf, 20 + len, IP_PACKET);
*** WARNING C182 IN LINE 79 OF IP.C: pointer to different objects
80 1 }
81
82
83
84 //------------------------------------------------------------------------
85 // This handles incoming IP datagrams from the Ethernet layer
86 // See "TCP/IP Illustrated, Volume 1" Sect 3.2
87 //------------------------------------------------------------------------
88 void ip_rcve(UCHAR xdata * inbuf)
89 {
90 1 IP_HEADER xdata * ip;
91 1 UINT idata header_len, payload_len;
92 1
93 1 ip = (IP_HEADER xdata *)(inbuf + 14);
94 1
95 1 // Make sure it is addressed to my IP address
96 1 if (ip->dest_ipaddr != my_ipaddr) return;
97 1
98 1 // Validate checksum of ip header
99 1 header_len = 4 * (0x0F & ip->ver_len);
100 1 payload_len = ip->total_length - header_len;
101 1 if (cksum(inbuf + 14, header_len) != 0xFFFF)
102 1 {
103 2 return;
104 2 }
105 1
106 1 // Make sure incoming message is IP version 4
107 1 if ((ip->ver_len >> 4) != 0x04)
108 1 {
109 2 return;
110 2 }
111 1
112 1 // Make sure incoming message is not fragmented because
113 1 // we cannot handle fragmented messages
114 1 if ((ip->fragment_info & 0x3FFF) != 0)
115 1 {
C51 COMPILER V8.08 IP 11/04/2008 18:45:34 PAGE 3
116 2 return;
117 2 }
118 1
119 1 // At this point we have received a valid IP datagram addressed
120 1 // to me. We do not use header options, and do not forward
121 1 // messages, so in the unlikely event there are header options,
122 1 // delete them and shift the data down. The advantage is that
123 1 // layers such as UDP and TCP know where their data starts
124 1 if (header_len > 20)
125 1 {
126 2
127 2 // Use memmove because of overlap
128 2 memmove(inbuf + 34, inbuf + 14 + header_len, payload_len);
129 2
130 2 // Adjust info to reflect the move
131 2 header_len = 20;
132 2 ip->ver_len = 0x45;
133 2 ip->total_length = 20 + payload_len;
134 2 }
135 1
136 1
137 1 // Look at protocol ID byte and call the appropriate
138 1 // function to handle the received message. See
139 1 // "TCP/IP Illustrated, Volume 1" Sect 1.7 and RFC 791
140 1 // for values for various protocols
141 1 switch (ip->protocol_id)
142 1 {
143 2 case ICMP_TYPE:
144 2 icmp_rcve(inbuf, payload_len);
145 2 break;
146 2
147 2 case IGMP_TYPE:
148 2 ;
149 2 // We cannot handle IGMP messages
150 2 break;
151 2
152 2 case UDP_TYPE:
153 2 udp_rcve(inbuf, payload_len);
154 2 break;
155 2
156 2 case TCP_TYPE:
157 2 tcp_rcve(inbuf, payload_len);
158 2 break;
159 2
160 2 default:
161 2 ;
162 2 break;
163 2 }
164 1 }
165
166
167
MODULE INFORMATION: STATIC OVERLAYABLE
CODE SIZE = 657 ----
CONSTANT SIZE = ---- ----
XDATA SIZE = 10 ----
PDATA SIZE = ---- ----
DATA SIZE = 2 15
IDATA SIZE = ---- 4
BIT SIZE = ---- ----
C51 COMPILER V8.08 IP 11/04/2008 18:45:34 PAGE 4
END OF MODULE INFORMATION.
C51 COMPILATION COMPLETE. 1 WARNING(S), 0 ERROR(S)
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