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
|
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#ifdef _SOLARIS_
#include "solaris.h"
#else
#include <sys/cdefs.h>
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <pcap.h>
#ifdef _BPF_
#include <errno.h>
#include <fcntl.h>
#endif
#ifndef DLT_RAW
#define DLT_RAW 12
#endif
#ifndef DLT_SLIP_BSDOS
#define DLT_SLIP_BSDOS 13
#endif
#ifndef DLT_PPP_BSDOS
#define DLT_PPP_BSDOS 14
#endif
#include "ip.h"
unsigned short ip_in_cksum(struct iphdr *iph, unsigned short *ptr, int nbytes)
{
register long sum = 0; /* assumes long == 32 bits */
u_short oddbyte;
register u_short answer; /* assumes u_short == 16 bits */
int pheader_len;
unsigned short *pheader_ptr;
struct pseudo_header {
unsigned long saddr;
unsigned long daddr;
unsigned char null;
unsigned char proto;
unsigned short tlen;
} pheader;
pheader.saddr = iph->saddr;
pheader.daddr = iph->daddr;
pheader.null = 0;
pheader.proto = iph->protocol;
pheader.tlen = htons(nbytes);
pheader_ptr = (unsigned short *)&pheader;
for (pheader_len = sizeof(pheader); pheader_len; pheader_len -= 2) {
sum += *pheader_ptr++;
}
while (nbytes > 1) {
sum += *ptr++;
nbytes -= 2;
}
if (nbytes == 1) { /* mop up an odd byte, if necessary */
oddbyte = 0; /* make sure top half is zero */
*((u_char *) & oddbyte) = *(u_char *) ptr; /* one byte only */
sum += oddbyte;
}
sum += (sum >> 16); /* add carry */
answer = ~sum; /* ones-complement, then truncate to 16 bits */
return (answer);
}
unsigned short in_cksum(unsigned short *ptr, int nbytes)
{
register long sum=0; /* assumes long == 32 bits */
u_short oddbyte;
register u_short answer; /* assumes u_short == 16 bits */
while(nbytes>1){
sum+=*ptr++;
nbytes-=2;
}
if(nbytes==1){ /* mop up an odd byte, if necessary */
oddbyte=0; /* make sure top half is zero */
*((u_char *)&oddbyte)=*(u_char *)ptr; /* one byte only */
sum+=oddbyte;
}
sum+=(sum>>16); /* add carry */
answer=~sum; /* ones-complement, then truncate to 16 bits */
return(answer);
}
int rawsock(void)
{
int fd,val=1;
if ((fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
croak("(rawsock) socket problems [fatal]");
}
if (setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &val, sizeof(val)) < 0) {
croak("Cannot set IP_HDRINCL socket option");
}
return fd;
}
u_long
host_to_ip (char *host_name)
{
struct hostent *target;
u_long *resolved_ip;
u_long host_resolved_ip;
resolved_ip = (u_long *) malloc (sizeof (u_long));
if ((target = gethostbyname (host_name)) == NULL)
{
croak("host_to_ip: failed");
}
else
{
bcopy (target->h_addr, resolved_ip, sizeof (struct in_addr));
host_resolved_ip = ntohl ((u_long) * resolved_ip);
free(resolved_ip);
return host_resolved_ip;
}
}
void
pkt_send (int fd, unsigned char * sock,u_char *pkt,int size)
{
if (sendto (fd, (const void *)pkt,size, 0, (const struct sockaddr *) sock, sizeof (struct sockaddr)) < 0)
{
close (fd);
croak("sendto()");
}
}
int
linkoffset(int type)
{
switch (type) {
case DLT_EN10MB:
return 14;
case DLT_SLIP:
return 16;
case DLT_SLIP_BSDOS:
return 24;
case DLT_NULL:
return 4;
case DLT_PPP:
return 4;
case DLT_PPP_BSDOS:
return 24;
case DLT_FDDI:
return 21;
case DLT_IEEE802:
return 22;
case DLT_ATM_RFC1483:
return 8;
case DLT_RAW:
return 0;
}
}
#ifdef _BPF_
int
bpf_open(void)
{
int fd;
int n = 0;
char device[sizeof "/dev/bpf000"];
do {
(void)sprintf(device, "/dev/bpf%d", n++);
fd = open(device, O_WRONLY);
} while (fd < 0 && errno == EBUSY);
if (fd < 0)
printf("%s: %s", device, pcap_strerror(errno));
return (fd);
}
#endif
|
