📄 ip.lst
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C51 COMPILER V7.07 IP 06/30/2006 16:21:48 PAGE 1
C51 COMPILER V7.07, 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
stmt level source
1 #include <stdio.h>
2 #include <string.h>
3 #include "ethernet.h"
4 #include "ip.h"
5
6 #define IP_TTL 128 /* Time To Live for an outgoing IP datagram */
7 extern NODE locnode; //本机的节点信息结构(mac,ip,mask,port)
8
9 /* Check ARP packet, swap bytes, return -1, 0 if not ARP */
10 int is_arp(ETHERFRAME *efp, int len)
11 {
12 1 ARPKT *arp;
13 1 int dlen=0;
14 1 if (efp->e.ptype==PCOL_ARP && len>=sizeof(ARPKT))
15 1 { /* If protocol OK.. */
16 2 arp = (ARPKT *)(efp->edata);
17 2 if (arp->hrd==HTYPE && arp->pro==ARPPRO)
18 2 dlen = -1; /* Return non-zero if OK */
19 2 else
20 2 dlen = 0;
21 2 }
22 1 return(dlen);
23 1 }
24
25 /* Make an ARP packet, return its total length */
26 int make_arp(ETHERFRAME *efp, NODE *srcep, NODE *destp, WORD codetype)
27 {
28 1 ARPKT *arp;
29 1 arp = (ARPKT *)(efp->edata);
30 1 memcpy(arp->smac, srcep->mac, MACLEN); /* Srce ARP ether addr */
31 1 memcpy(arp->dmac, destp->mac, MACLEN); /* Dest ARP ether addr */
32 1 arp->hrd = HTYPE; /* Hware & protocol types */
33 1 arp->pro = ARPPRO;
34 1 arp->hln = MACLEN; /* Hardware addr len */
35 1 arp->pln = sizeof(LWORD); /* IP addr len */
36 1 arp->op = codetype; /* ARP opcode */
37 1 arp->dip = gate_ip(destp, srcep); /* Dest ip addr (maybe gateway) */
38 1 arp->sip = srcep->ip; /* Source IP addr */
39 1 return(make_frame(efp,srcep->mac,destp->mac, PCOL_ARP, sizeof(ARPKT)));
40 1 }
41
42 /* Check frame is IP, checksum & byte-swap, return data len */
43 int is_ip(ETHERFRAME *efp, int len)
44 {
45 1 int ver, dlen=0, hlen;
46 1 WORD sum;
47 1 IPKT *ip;
48 1 if (efp->e.ptype==PCOL_IP && len>=sizeof(IPHDR))
49 1 {
50 2 ip = (IPKT *)(efp->edata); /* Get pointer to IP frame */
51 2 ver = ip->i.vhl >> 4; /* Get IP version & hdr len */
52 2 hlen = (ip->i.vhl & 0xf) << 2;
53 2 sum = ~csum(&ip->i, (WORD)hlen); /* Do checksum */
54 2 if (ver==4 && len>=hlen && sum==0) /* If OK.. */
55 2 {
C51 COMPILER V7.07 IP 06/30/2006 16:21:48 PAGE 2
56 3 dlen = min(ip->i.len,len);
57 3 dlen-=hlen;
58 3 if (hlen > sizeof(IPHDR)) /* If IP options present.. */
59 3 { /* ..delete them, move data down */
60 4 memmove(ip->ipdata, &ip->ipdata[hlen-sizeof(IPHDR)], len);
61 4 dlen -= hlen-sizeof(IPHDR);
62 4 }
63 3 }
64 2 }
65 1 return(dlen);
66 1 }
67
68 /* Make an IP packet, if greater than the MTU, also make fragment (subframe) in
69 ** this frame. Return total length of frame and subframes (if any) */
70 int make_ip(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE pcol, WORD dlen)
71 {
72 1 IPKT *ip;
73 1 static WORD ident=1;
74 1 ip = (IPKT *)(efp->edata); /* Get pointer to IP datagram */
75 1 ip->i.ident = ident; /* Set datagram ident */
76 1 ip->i.frags = 0; /* Frag offset in units of 8 bytes */
77 1 ip->i.vhl = 0x40+(sizeof(IPHDR)>>2); /* Version 4, header len 5 LWORDs */
78 1 ip->i.service = 0; /* Routine message */
79 1 ip->i.ttl = IP_TTL; /* Time To Live */
80 1 ip->i.pcol = pcol; /* Set IP protocol */
81 1 ip->i.sip = srcep->ip; /* Srce, dest IP addrs */
82 1 ip->i.dip = destp->ip;
83 1 ip->i.len = dlen + sizeof(IPHDR); /* Data length */
84 1 ip->i.check = 0; /* Clear checksum */
85 1 ip->i.check = ~csum(ip, sizeof(IPHDR)); /* ..then set to calc value */
86 1 ident++; /* Increment datagram ident */
87 1 return(make_frame(efp, srcep->mac,destp->mac, PCOL_IP, (WORD)dlen+sizeof(IPHDR)));
88 1 }
89
90 /* Get the frame driver type, source IP and Ethernet addresses
91 ** Returned data does not include port number, netmask or gateway addr */
92 void getip_srce(ETHERFRAME *efp, NODE *np)
93 {
94 1 IPHDR *iph;
95 1 memcpy(np->mac,efp->e.srce,6);
96 1 iph = (IPHDR *)(efp->edata);
97 1 np->ip = iph->sip;
98 1 }
99
100 /* Get local node data corresponding to a frame destination IP address
101 ** Data does not include port number. Return 0 if no matching local node */
102 int getip_locdest(ETHERFRAME *efp,NODE *np)
103 {
104 1 IPHDR *iph;
105 1 int ok=0;
106 1
107 1 iph =(IPHDR *)(efp->edata);
108 1 if (iph->dip==locnode.ip)
109 1 {
110 2 *np=locnode;
111 2 ok=1;
112 2 }
113 1 return (ok);
114 1 }
115
116 /* Check a remote address to see if it is on the local subnet.
117 ** If so (or no gateway), return it. If not, return the gateway IP address */
C51 COMPILER V7.07 IP 06/30/2006 16:21:48 PAGE 3
118 LWORD gate_ip(NODE *remp, NODE *locp)
119 {
120 1 return((locp->gate==0||on_subnet(remp->ip, locp)) ? remp->ip : locp->gate);
121 1 }
122
123 /* Check an IP address to see if it is on a subnet, return 0 if not */
124 int on_subnet(LWORD remip, NODE *locp)
125 {
126 1 return(((remip ^ locp->ip) & locp->mask) == 0);
127 1 }
128
129
130 /* Return ICMP data length (-1 if no data), 0 if not ICMP */
131 int is_icmp(IPKT *ip, int len)
132 {
133 1 ICMPKT *icmp;
134 1 WORD sum;
135 1 int dlen=0;
136 1
137 1 if (ip->i.pcol==PICMP && len>=sizeof(ICMPHDR))
138 1 {
139 2 icmp = (ICMPKT *)ip;
140 2 if ((sum=csum(&icmp->c, (WORD)len)) == 0xffff)
141 2 dlen = len>sizeof(ICMPHDR) ? len-sizeof(ICMPHDR) : -1;
142 2 // else
143 2 // printf("\r\nICMP checksum error: %04X\r\n", sum);
144 2 }
145 1 return(dlen);
146 1 }
147
148 /* Make an ICMP packet */
149 int make_icmp(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE type, BYTE codetype,WORD dlen)
150 {
151 1 ICMPKT *icmp;
152 1 WORD len;
153 1 icmp = (ICMPKT *)(efp->edata);
154 1 icmp->c.type = type;
155 1 icmp->c.codetype = codetype;
156 1 icmp->c.check = 0;
157 1 len = (WORD)(dlen + sizeof(ICMPHDR));
158 1 icmp->c.check = ~csum(&icmp->c, len);
159 1 return(make_ip(efp, srcep, destp, PICMP, len));
160 1 }
161
162 /* Make ICMP 'destination unreachable' for incoming frame */
163
164 /*
165 int icmp_unreach(ETHERFRAME *efp, NODE *srcep, NODE *destp, BYTE codetype)
166 {
167 int len;
168 ICMPKT *icmp;
169 icmp = (ICMPKT *)(efp->edata);
170 len = ((icmp->i.vhl & 0xf) << 2) + 8;
171 memmove(icmp->icmpdata, icmp, len);
172 return(make_icmp(efp, srcep, destp, ICUNREACH, codetype, (WORD)len));
173 }
174 */
175
176
MODULE INFORMATION: STATIC OVERLAYABLE
C51 COMPILER V7.07 IP 06/30/2006 16:21:48 PAGE 4
CODE SIZE = 1519 ----
CONSTANT SIZE = ---- ----
XDATA SIZE = 2 93
PDATA SIZE = ---- ----
DATA SIZE = ---- ----
IDATA SIZE = ---- ----
BIT SIZE = ---- ----
END OF MODULE INFORMATION.
C51 COMPILATION COMPLETE. 0 WARNING(S), 0 ERROR(S)
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