📄 ip.lst
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C51 COMPILER V6.21 IP 03/08/2002 13:07:31 PAGE 1
C51 COMPILER V6.21, COMPILATION OF MODULE IP
OBJECT MODULE PLACED IN ip.OBJ
COMPILER INVOKED BY: C:\KEIL\C51\BIN\C51.EXE ip.c LARGE OPTIMIZE(SIZE) BROWSE DEBUG OBJECTEXTEND
stmt level source
1 #include <stdio.h>
2 #include <string.h>
3 #include "ethernet.h"
4 #include "ip.h"
5 #define IP_TTL 128 /* Time To Live for an outgoing IP datagram */
6 extern NODE locnode; //本机的节点信息结构(mac,ip,mask,port)
7 /* Check ARP packet, swap bytes, return -1, 0 if not ARP */
8 int is_arp(ETHERFRAME *efp, int len)
9 {
10 1 ARPKT *arp;
11 1 int dlen=0;
12 1 if (efp->e.ptype==PCOL_ARP && len>=sizeof(ARPKT))
13 1 { /* If protocol OK.. */
14 2 arp = (ARPKT *)(efp->edata);
15 2 if (arp->hrd==HTYPE && arp->pro==ARPPRO)
16 2 dlen = -1; /* Return non-zero if OK */
17 2 else
18 2 dlen = 0;
19 2 }
20 1 return(dlen);
21 1 }
22 /* Make an ARP packet, return its total length */
23 int make_arp(ETHERFRAME *efp, NODE *srcep, NODE *destp, WORD codetype)
24 {
25 1 ARPKT *arp;
26 1 arp = (ARPKT *)(efp->edata);
27 1 memcpy(arp->smac, srcep->mac, MACLEN); /* Srce ARP ether addr */
28 1 memcpy(arp->dmac, destp->mac, MACLEN); /* Dest ARP ether addr */
29 1 arp->hrd = HTYPE; /* Hware & protocol types */
30 1 arp->pro = ARPPRO;
31 1 arp->hln = MACLEN; /* Hardware addr len */
32 1 arp->pln = sizeof(LWORD); /* IP addr len */
33 1 arp->op = codetype; /* ARP opcode */
34 1 arp->dip = gate_ip(destp, srcep); /* Dest ip addr (maybe gateway) */
35 1 arp->sip = srcep->ip; /* Source IP addr */
36 1 return(make_frame(efp,srcep->mac,destp->mac, PCOL_ARP, sizeof(ARPKT)));
37 1 }
38
39 /* Check frame is IP, checksum & byte-swap, return data len */
40 int is_ip(ETHERFRAME *efp, int len)
41 {
42 1 int ver, dlen=0, hlen;
43 1 WORD sum;
44 1 IPKT *ip;
45 1 if (efp->e.ptype==PCOL_IP && len>=sizeof(IPHDR))
46 1 {
47 2 ip = (IPKT *)(efp->edata); /* Get pointer to IP frame */
48 2 ver = ip->i.vhl >> 4; /* Get IP version & hdr len */
49 2 hlen = (ip->i.vhl & 0xf) << 2;
50 2 sum = ~csum(&ip->i, (WORD)hlen); /* Do checksum */
51 2 if (ver==4 && len>=hlen && sum==0) /* If OK.. */
52 2 {
53 3 dlen = min(ip->i.len,len);
54 3 dlen-=hlen;
55 3 if (hlen > sizeof(IPHDR)) /* If IP options present.. */
C51 COMPILER V6.21 IP 03/08/2002 13:07:31 PAGE 2
56 3 { /* ..delete them, move data down */
57 4 memmove(ip->ipdata, &ip->ipdata[hlen-sizeof(IPHDR)], len);
58 4 dlen -= hlen-sizeof(IPHDR);
59 4 }
60 3 }
61 2 }
62 1 return(dlen);
63 1 }
64
65 /* Make an IP packet, if greater than the MTU, also make fragment (subframe) in
66 ** this frame. Return total length of frame and subframes (if any) */
67 int make_ip(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE pcol, WORD dlen)
68 {
69 1 IPKT *ip;
70 1 static WORD ident=1;
71 1 ip = (IPKT *)(efp->edata); /* Get pointer to IP datagram */
72 1 ip->i.ident = ident; /* Set datagram ident */
73 1 ip->i.frags = 0; /* Frag offset in units of 8 bytes */
74 1 ip->i.vhl = 0x40+(sizeof(IPHDR)>>2); /* Version 4, header len 5 LWORDs */
75 1 ip->i.service = 0; /* Routine message */
76 1 ip->i.ttl = IP_TTL; /* Time To Live */
77 1 ip->i.pcol = pcol; /* Set IP protocol */
78 1 ip->i.sip = srcep->ip; /* Srce, dest IP addrs */
79 1 ip->i.dip = destp->ip;
80 1 ip->i.len = dlen + sizeof(IPHDR); /* Data length */
81 1 ip->i.check = 0; /* Clear checksum */
82 1 ip->i.check = ~csum(ip, sizeof(IPHDR)); /* ..then set to calc value */
83 1 ident++; /* Increment datagram ident */
84 1 return(make_frame(efp, srcep->mac,destp->mac, PCOL_IP, (WORD)dlen+sizeof(IPHDR)));
85 1 }
86
87 /* Get the frame driver type, source IP and Ethernet addresses
88 ** Returned data does not include port number, netmask or gateway addr */
89 void getip_srce(ETHERFRAME *efp, NODE *np)
90 {
91 1 IPHDR *iph;
92 1 memcpy(np->mac,efp->e.srce,6);
93 1 iph = (IPHDR *)(efp->edata);
94 1 np->ip = iph->sip;
95 1 }
96 /* Get local node data corresponding to a frame destination IP address
97 ** Data does not include port number. Return 0 if no matching local node */
98 int getip_locdest(ETHERFRAME *efp,NODE *np)
99 {
100 1 IPHDR *iph;
101 1 int ok=0;
102 1
103 1 iph =(IPHDR *)(efp->edata);
104 1 if (iph->dip==locnode.ip)
105 1 {
106 2 *np=locnode;
107 2 ok=1;
108 2 }
109 1 return (ok);
110 1 }
111
112 /* Check a remote address to see if it is on the local subnet.
113 ** If so (or no gateway), return it. If not, return the gateway IP address */
114 LWORD gate_ip(NODE *remp, NODE *locp)
115 {
116 1 return((locp->gate==0||on_subnet(remp->ip, locp)) ? remp->ip : locp->gate);
117 1 }
C51 COMPILER V6.21 IP 03/08/2002 13:07:31 PAGE 3
118
119 /* Check an IP address to see if it is on a subnet, return 0 if not */
120 int on_subnet(LWORD remip, NODE *locp)
121 {
122 1 return(((remip ^ locp->ip) & locp->mask) == 0);
123 1 }
124
125
126 /* Return ICMP data length (-1 if no data), 0 if not ICMP */
127 int is_icmp(IPKT *ip, int len)
128 {
129 1 ICMPKT *icmp;
130 1 WORD sum;
131 1 int dlen=0;
132 1
133 1 if (ip->i.pcol==PICMP && len>=sizeof(ICMPHDR))
134 1 {
135 2 icmp = (ICMPKT *)ip;
136 2 if ((sum=csum(&icmp->c, (WORD)len)) == 0xffff)
137 2 dlen = len>sizeof(ICMPHDR) ? len-sizeof(ICMPHDR) : -1;
138 2 // else
139 2 // printf("\r\nICMP checksum error: %04X\r\n", sum);
140 2 }
141 1 return(dlen);
142 1 }
143
144 /* Make an ICMP packet */
145 int make_icmp(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE type, BYTE codetype,WORD dlen)
146 {
147 1 ICMPKT *icmp;
148 1 WORD len;
149 1 icmp = (ICMPKT *)(efp->edata);
150 1 icmp->c.type = type;
151 1 icmp->c.codetype = codetype;
152 1 icmp->c.check = 0;
153 1 len = (WORD)(dlen + sizeof(ICMPHDR));
154 1 icmp->c.check = ~csum(&icmp->c, len);
155 1 return(make_ip(efp, srcep, destp, PICMP, len));
156 1 }
157
158 /* Make ICMP 'destination unreachable' for incoming frame */
159
160 /*
161 int icmp_unreach(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE codetype)
162 {
163 int len;
164 ICMPKT *icmp;
165 icmp = (ICMPKT *)(efp->edata);
166 len = ((icmp->i.vhl & 0xf) << 2) + 8;
167 memmove(icmp->icmpdata, icmp, len);
168 return(make_icmp(efp, srcep, destp, ICUNREACH, codetype, (WORD)len));
169 }
170 */
171
172
MODULE INFORMATION: STATIC OVERLAYABLE
CODE SIZE = 1513 ----
CONSTANT SIZE = ---- ----
XDATA SIZE = 2 93
PDATA SIZE = ---- ----
C51 COMPILER V6.21 IP 03/08/2002 13:07:31 PAGE 4
DATA SIZE = ---- ----
IDATA SIZE = ---- ----
BIT SIZE = ---- ----
END OF MODULE INFORMATION.
C51 COMPILATION COMPLETE. 0 WARNING(S), 0 ERROR(S)
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