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
|
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include "tsg_entry.h"
#include "tsg_protocol_common.h"
#define IPV4_TYPE 1 //ADDR_TYPE_IPV4 ==1 , 取的enum 0x0800
#define IPV6_TYPE 2 //ADDR_TYPE_IPV6 ==2 0x86dd
#define TCP_TYPE 0x06
#define UDP_TYPE 0x11
#define ICMP_PROTOCOL_TYPE 0x01 //ipv4 icmp proctocol
#define ICMPV6_PROTOCAL_TYPE 0x3a //ipv6 icmpv6 protocl
#define ICMPV4_UNREACHABLE 0x03
#define ICMPV4_PORT_UNREACHABLE 0x03
#define ICMPV6_UNREACHABLE 0x01
#define ICMPV6_PORT_UNREACHABLE 0X04
#define MAC_LEN 6
#define MAC_LEN_2 ((MAC_LEN)+(MAC_LEN))
#define ETH_IP_TYPE_LEN 2
#define ETH_LEN ((MAC_LEN_2)+(ETH_IP_TYPE_LEN))
#define TCP_MAX_LEN 60
#define ICMP_IPV4_TCP_MAX_LEN 44 //64-20 = 44
#define IPV4_SHAM_FIXED_LEN 12
#define IPV4_LEN 20
#define IPV4_IP_LEN 4
#define IPV4_IP_LEN_INDEX 2 //eth_len(14)+ ip_len_index(2)
#define IPV6_LEN 40
#define IPV6_IP_LEN 16
#define IPV6_IP_PAYLOAD_INDEX 4 // ipv6_payload_index(4)
#define ICMP_IPV4_PROTOCOL_TYPE_LEN 24
#define ICMP_HEAD_LEN 8
#define ICMPV4_SOURCE_MAX_LEN 64
#define ICMPV4_MAX_LEN ((ICMPV4_SOURCE_MAX_LEN)+(ICMP_HEAD_LEN))
#define IPV6_PESUDO_HEAD_LEN 40
//icmpv6的srcPacket len需要再确认
#define ICMP_MAX_LEN 65535 //eth_len(14) + ipv6_len(40) + ICMP_MAX_LEN(8+128)
#define ICMP_SRCPACKET_MAX_LEN 548 // 548 == ipv4(max_len 576)-ip_len(20)-icmp_head_len(8)
#define ICMPV6_SRCPACKET_MAX_LEN 1232 // 1232 == ipv6(max_len 1280)-ipv6_len(40)-icmp_head_len(8)
typedef struct icmpv4{
char type;
char code;
short checksum;
char un_user[4];
char srcPacket[ICMPV6_SRCPACKET_MAX_LEN];
}icmpv4_st, icmpv6_st;
short in_checksum(void *pkg, int size)
{
int nleft = size;
int sum = 0;
unsigned short *w = (unsigned short *)pkg;
unsigned short answer = 0;
while (nleft > 1)
{
sum += *w++;
nleft -= 2;
}
if (nleft == 1)
{
* (unsigned char *) (&answer) = *(unsigned char *)w;
sum += answer;
}
while (sum >> 16){
sum = (sum & 0xFFFF) + (sum >> 16);
}
answer = ~sum &0xffff;
return answer;
}
static void format_icmpv4(const char *raw_pkt, char *buf, int *len){
char ipv4[IPV4_LEN] = {0};
icmpv4_st icmpst = {0};
short src_ipv4_total_len = 0;
short icmpv4_complete_len = 0;
short icmp_len = 0;
short icmp_srcpacket_len = 0;
short icmp_start_len = IPV4_LEN;
short ipv4_total_len = 0;
short ipv4_checksum = 0;
short sip_len = 12; //skip sip start index
short dip_len = 16; //skip dip start index
memcpy(&src_ipv4_total_len, &raw_pkt[IPV4_IP_LEN_INDEX], sizeof(short));
src_ipv4_total_len = htons(src_ipv4_total_len);
//src_packet_len = src_ipv4_total_len + ETH_LEN;
if(src_ipv4_total_len >= ICMP_SRCPACKET_MAX_LEN){
icmp_srcpacket_len = ICMP_SRCPACKET_MAX_LEN;
}else{
icmp_srcpacket_len = src_ipv4_total_len;
}
icmp_len = icmp_srcpacket_len + ICMP_HEAD_LEN;
ipv4_total_len = icmp_len + IPV4_LEN;
icmpv4_complete_len = IPV4_LEN + icmp_len;
//format icmp information
memset(&icmpst, 0, sizeof(icmpv4_st));
memcpy(icmpst.srcPacket, raw_pkt, icmp_srcpacket_len); //
icmpst.type = ICMPV4_UNREACHABLE;
icmpst.code = ICMPV4_PORT_UNREACHABLE;
icmpst.checksum = in_checksum((void*)&icmpst, icmp_len);
//format ipv4
memcpy(ipv4, raw_pkt, IPV4_LEN); //copy source data
memcpy(&ipv4[12], &raw_pkt[dip_len], IPV4_IP_LEN); //get sip
memcpy(&ipv4[16], &raw_pkt[sip_len], IPV4_IP_LEN); //get dip
ipv4[9] = ICMP_PROTOCOL_TYPE; //set ipv4 protocol type (0x01 == ICMP)
ipv4_total_len = htons(ipv4_total_len);
memcpy(&ipv4[2], &ipv4_total_len, sizeof(short)); //format ipv4 len
memset(&ipv4[10], 0, sizeof(short)); //empty checksum data
ipv4_checksum = in_checksum(ipv4, IPV4_LEN); //calc ipv4 checksum
memcpy(&ipv4[10], &ipv4_checksum, sizeof(short)); //format checksum
//format complete icmpv4 packet
memcpy(buf, ipv4, IPV4_LEN);
memcpy(&buf[icmp_start_len], &icmpst, icmp_len);
*len = icmpv4_complete_len;
return;
}
//int format_icmpv6(char *icmp, short icmp_len, char *eth, const char *data){
#if 0
static void format_icmpv6(const char *data, char *buf, int *len){
char checksum_str[ICMPV6_SRCPACKET_MAX_LEN] = {0};
char ipv6[IPV6_LEN] = {0};
icmpv6_st icmpst = {0};
short src_ipv6_total_len = 0;
short icmpv6_complete_len = 0;
short icmp_len = 0;
short icmp_srcpacket_len = 0;
short icmp_start_len = IPV6_LEN;
short checksum_len = 0;
short sip_len = 8; //skip sip start index
short dip_len = 24; //skip dip start index, 16+8 == 24
short ipv6_ip2 = IPV6_IP_LEN + IPV6_IP_LEN;
short payload_len = 0;
short fill_icmp_len = 0;
int checksum_payload_len = 0;
memcpy(&src_ipv6_total_len, &data[IPV6_IP_PAYLOAD_INDEX], sizeof(short)); //get ipv6_payload_len
src_ipv6_total_len = htons(src_ipv6_total_len) + IPV6_LEN;
if(src_ipv6_total_len >= ICMPV6_SRCPACKET_MAX_LEN){
icmp_srcpacket_len = ICMPV6_SRCPACKET_MAX_LEN;
}else{
icmp_srcpacket_len = src_ipv6_total_len;
}
icmp_len = icmp_srcpacket_len + ICMP_HEAD_LEN;
icmpv6_complete_len = IPV6_LEN + icmp_len;
checksum_len = icmp_len + IPV6_PESUDO_HEAD_LEN;
payload_len = htons(icmp_len);
//format ipv6
memcpy(ipv6, data, IPV6_LEN); //copy source ipv6 data
memcpy(&ipv6[8], &data[dip_len], IPV6_IP_LEN); //get sip
memcpy(&ipv6[24],&data[sip_len], IPV6_IP_LEN); //get dip
memcpy(&ipv6[4], &payload_len, sizeof(short)); //format ipv6 payload
ipv6[6] = ICMPV6_PROTOCAL_TYPE; //format ipv6 protocol (icmpv6 == 0X3a);
//format icmp
memset(&icmpst, 0, sizeof(icmpv6_st));
icmpst.type = ICMPV6_UNREACHABLE;
icmpst.code = ICMPV6_PORT_UNREACHABLE;
memcpy(icmpst.srcPacket, data, icmp_srcpacket_len);
//补充为4字节
checksum_payload_len = htonl((int)icmp_len);
fill_icmp_len = icmp_len % 4;
if( fill_icmp_len > 0){
icmp_len = icmp_len + (4-fill_icmp_len);
checksum_len = checksum_len + (4-fill_icmp_len);
}
//calc icmpv6 checksum
memcpy(checksum_str, &icmpst, icmp_len);
memcpy(&checksum_str[icmp_len], &ipv6[8], ipv6_ip2);
memcpy(&checksum_str[icmp_len+ipv6_ip2], &checksum_payload_len, sizeof(int));
checksum_str[icmp_len+ipv6_ip2+7] = ICMPV6_PROTOCAL_TYPE;
icmpst.checksum = in_checksum(checksum_str, checksum_len);
//format complete icmpv6 packet
memcpy(buf, ipv6, IPV6_LEN);
memcpy(&buf[icmp_start_len], &icmpst, icmp_len);
*len = icmpv6_complete_len;
return;
}
#endif
static void format_icmp(const char *raw_pkt, char *icmp_buf, int *icmp_len, int ip_type){
if(IPV4_TYPE == ip_type) {
format_icmpv4(raw_pkt, icmp_buf, icmp_len);
}
//else{ //IPV6_TYPE
// format_icmpv6(raw_pkt, icmp_buf, icmp_len);
//}
return;
}
//int send_icmp_unreach_xxx(const void *raw_pkt, xxxxx)
unsigned char send_icmp_unreachable(const struct streaminfo *a_stream, const void *raw_pkt)
{
char icmp_buf[ICMP_MAX_LEN];
unsigned char raw_route_dir = 0;
int icmp_len = 0;
if(a_stream == NULL){
return STATE_DROPPKT;
}
if((a_stream->curdir==DIR_S2C)||(raw_pkt==NULL)||(a_stream->addr.addrtype!=IPV4_TYPE)){
return STATE_DROPPKT;
}
format_icmp((char *)raw_pkt, icmp_buf, &icmp_len, a_stream->addr.addrtype);
raw_route_dir = (a_stream->curdir==DIR_C2S) ? MESA_dir_reverse(a_stream->routedir) : a_stream->routedir;
return tsg_send_inject_packet(a_stream, SIO_EXCLUDE_THIS_LAYER_HDR, icmp_buf, icmp_len, raw_route_dir);
}
|
