1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
|
#include "libping.h"
/* From Stevens, UNP2ev1 */
unsigned short
in_cksum(unsigned short *addr, int len)
{
int nleft = len;
int sum = 0;
unsigned short *w = addr;
unsigned short answer = 0;
while (nleft > 1)
{
sum += *w++;
nleft -= 2;
}
if (nleft == 1)
{
*(unsigned char *)(&answer) = *(unsigned char *)w;
sum += answer;
}
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16);
answer = ~sum;
return (answer);
}
// Computing the internet checksum (RFC 1071).
// Note that the internet checksum does not preclude collisions.
uint16_t
ip_checksum (uint16_t *addr, int len)
{
int count = len;
register uint32_t sum = 0;
uint16_t answer = 0;
// Sum up 2-byte values until none or only one byte left.
while (count > 1) {
sum += *(addr++);
count -= 2;
}
// Add left-over byte, if any.
if (count > 0) {
sum += *(uint8_t *) addr;
}
// Fold 32-bit sum into 16 bits; we lose information by doing this,
// increasing the chances of a collision.
// sum = (lower 16 bits) + (upper 16 bits shifted right 16 bits)
while (sum >> 16) {
sum = (sum & 0xffff) + (sum >> 16);
}
// Checksum is one's compliment of sum.
answer = ~sum;
return (answer);
}
int icmp_eth_init( icmp_pckt_t *icmp )
{
uint8_t dest[] = {0x00,0x22,0x43,0x68,0xe5,0xab};
uint8_t src[] = {0x6c,0x88,0x14,0x0a,0x89,0x58};
memcpy( icmp->eth_dest, dest, 6 );
memcpy( icmp->eth_src, src, 6 );
icmp->eth_type = 0x0008;
return 0;
}
int icmp_eth_dest( icmp_pckt_t *icmp, uint8_t *mac )
{
memcpy( icmp->eth_dest, mac, 6 );
return 0;
}
int icmp_eth_src( icmp_pckt_t *icmp, uint8_t *mac )
{
memcpy( icmp->eth_src, mac, 6 );
return 0;
}
int icmp_eth_len( icmp_pckt_t *icmp )
{
return 14;
}
int icmp_ip_init( icmp_pckt_t *icmp )
{
icmp->head_hlength = 0x45; //ip4,header size 20 byte
icmp->tos = 0x00;
icmp->ip_length = htons(20+8+ICMP_MAX_DATA); //ip4 header + icmp message
icmp->ip_ident = htons(0xfbea);
icmp->flags_fragment_off = 0x0040;
icmp->ttl = 64;
icmp->protocol = 1; //ICMP
icmp->source_addr = inet_addr("127.0.0.1");
icmp->dest_addr = inet_addr("127.0.0.1");
return 0;
}
int icmp_ip_chksum( icmp_pckt_t *icmp )
{
uint16_t chk;
icmp->ip_chksum = 0;
chk = ip_checksum( (uint16_t *)icmp+7, 20 );
icmp->ip_chksum = chk;
return 0;
}
int icmp_ip_dest( icmp_pckt_t *icmp, uint32_t dest )
{
uint32_t s = dest;
uint8_t a,b,c,d;
a = s;
b = s>>8;
c = s>>16;
d = s>>24;
uint32_t aa = a;
uint32_t bb = b;
uint32_t cc = c;
uint32_t dd = d;
printf("%d.%d.%d.%d\n",a,b,c,d);
s = 0x0;
s = aa + (bb<<8) + (cc<<16) + (dd<<24);
icmp->dest_addr = s;
return 0;
}
int icmp_ip_src( icmp_pckt_t *icmp, uint32_t src )
{
uint32_t s = src;
uint8_t a,b,c,d;
a = s;
b = s>>8;
c = s>>16;
d = s>>24;
uint32_t aa = a;
uint32_t bb = b;
uint32_t cc = c;
uint32_t dd = d;
printf("%d.%d.%d.%d\n",a,b,c,d);
s = 0x0;
s = aa + (bb<<8) + (cc<<16) + (dd<<24);
icmp->source_addr = s;
return 0;
}
int icmp_ip_ident( icmp_pckt_t *icmp, uint16_t ident )
{
icmp->ip_ident = htons(ident);
//icmp->ip_ident = ident;
return 0;
}
int icmp_ip_ttl( icmp_pckt_t *icmp, uint8_t ttl )
{
icmp->ttl = ttl;
return 0;
}
int icmp_ip_len( icmp_pckt_t *icmp )
{
return 20;
}
int icmp_icmp_init( icmp_pckt_t *icmp )
{
int i = 0;
icmp->type = ICMP_TREQUEST;
icmp->code = 0;
icmp->icmp_ident = 0x4062;
icmp->seq_num = 0x0001;
//icmp->timestamp = 0x5749aae7;//0xe7aa4957;
for (i=0;i<ICMP_MAX_DATA;i++)
{
icmp->data[i] = 0;
}
return 0;
}
int icmp_icmp_set_chks( icmp_pckt_t *icmp )
{
uint16_t chk=0x0;
uint16_t offset=0x0;
icmp->icmp_check_sum = 0x0000;
//fot ICMP header
offset = icmp_eth_len(icmp) + icmp_ip_len(icmp);
printf("offset %d len %d\n", offset, icmp_icmp_len(icmp));
chk = ip_checksum( ((uint16_t *)icmp)+offset/2,
icmp_icmp_len(icmp) );
icmp->icmp_check_sum = chk;
return 0;
}
int icmp_icmp_set_code( icmp_pckt_t *icmp, uint8_t code )
{
return 0;
}
int icmp_icmp_set_type( icmp_pckt_t *icmp, uint8_t type )
{
icmp->type = type;
return 0;
}
int icmp_icmp_len( icmp_pckt_t *icmp )
{
return 8+ICMP_MAX_DATA;
}
int icmp_icmp_ident( icmp_pckt_t *icmp, uint16_t ident )
{
icmp->icmp_ident = htons(ident);
return 0;
}
int icmp_icmp_seq( icmp_pckt_t *icmp, uint16_t seq)
{
icmp->seq_num = htons(seq);
return 0;
}
int icmp_total_len( icmp_pckt_t *icmp )
{
int ret=0;
ret = icmp_eth_len(icmp)
+icmp_ip_len(icmp)
+icmp_icmp_len(icmp);
return ret;
}
int icmp_icmp_ts( icmp_pckt_t *icmp, uint64_t timestamp )
{
//icmp->timestamp = timestamp;
return 0;
}
int icmp_dump( icmp_pckt_t *icmp )
{
int i=0,j=0,m=0;
printf("Etherenet header\n");
for (i=0;i<j+14;i++)
{
printf("%02X ", ((unsigned char *)icmp)[i]);
if (i%16==15) printf("\n");
}
printf("\n");
j = i;
printf("IP header\n");
for (i=j,m=0;i<j+20;i++,m++)
{
printf("%02X ", ((unsigned char *)icmp)[i]);
if (m%16==15) printf("\n");
}
printf("\n");
j = i;
printf("ICMP header\n");
for (i=j,m=0;i<sizeof(icmp_pckt_t);i++,m++)
{
printf("%02X ", ((unsigned char *)icmp)[i]);
if (m%16==15) printf("\n");
}
printf("\n");
return 0;
}
int icmp_data( icmp_pckt_t *icmp, uint8_t *data, size_t size )
{
memcpy( icmp->data, data, size );
return 0;
}
|
