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
|
/*
* resend.c (C) 1995-1998 Darren Reed
*
* See the IPFILTER.LICENCE file for details on licencing.
*
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
# include <netinet/ip_var.h>
# include <netinet/if_ether.h>
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "ipsend.h"
extern int opts;
void dumppacket(ip_t *);
void
dumppacket(ip_t *ip)
{
tcphdr_t *t;
int i, j;
t = (tcphdr_t *)((char *)ip + (IP_HL(ip) << 2));
if (ip->ip_tos)
printf("tos %#x ", ip->ip_tos);
if (ip->ip_off & 0x3fff)
printf("frag @%#x ", (ip->ip_off & 0x1fff) << 3);
printf("len %d id %d ", ip->ip_len, ip->ip_id);
printf("ttl %d p %d src %s", ip->ip_ttl, ip->ip_p,
inet_ntoa(ip->ip_src));
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
printf(",%d", t->th_sport);
printf(" dst %s", inet_ntoa(ip->ip_dst));
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
printf(",%d", t->th_dport);
if (ip->ip_p == IPPROTO_TCP) {
printf(" seq %lu:%lu flags ",
(u_long)t->th_seq, (u_long)t->th_ack);
for (j = 0, i = 1; i < TH_FLAGS; i <<= 1, j++)
if (__tcp_get_flags(t) & i)
printf("%c", "FSRPAUEWe"[j]);
}
putchar('\n');
}
int
ip_resend(char *dev, int mtu, struct ipread *r, struct in_addr gwip,
char *datain)
{
ether_header_t *eh;
char dhost[6];
ip_t *ip;
int fd, wfd = initdevice(dev, 5), len, i;
mb_t mb;
if (wfd == -1)
return (-1);
if (datain)
fd = (*r->r_open)(datain);
else
fd = (*r->r_open)("-");
if (fd < 0)
exit(-1);
ip = (struct ip *)mb.mb_buf;
eh = (ether_header_t *)malloc(sizeof(*eh));
if(!eh)
{
perror("malloc failed");
return (-2);
}
bzero((char *) &eh->ether_shost, sizeof(eh->ether_shost));
if (gwip.s_addr && (arp((char *)&gwip, dhost) == -1))
{
perror("arp");
free(eh);
return (-2);
}
while ((i = (*r->r_readip)(&mb, NULL, NULL)) > 0)
{
if (!(opts & OPT_RAW)) {
len = ntohs(ip->ip_len);
eh = (ether_header_t *)realloc((char *)eh, sizeof(*eh) + len);
eh->ether_type = htons((u_short)ETHERTYPE_IP);
if (!gwip.s_addr) {
if (arp((char *)&gwip,
(char *) &eh->ether_dhost) == -1) {
perror("arp");
continue;
}
} else
bcopy(dhost, (char *) &eh->ether_dhost,
sizeof(dhost));
if (!ip->ip_sum)
ip->ip_sum = chksum((u_short *)ip,
IP_HL(ip) << 2);
bcopy(ip, (char *)(eh + 1), len);
len += sizeof(*eh);
dumppacket(ip);
} else {
eh = (ether_header_t *)mb.mb_buf;
len = i;
}
if (sendip(wfd, (char *)eh, len) == -1)
{
perror("send_packet");
break;
}
}
(*r->r_close)();
free(eh);
return (0);
}
|
