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
|
/*
* eth.c
*
* Copyright (c) 2001 Dug Song <dugsong@monkey.org>
*
* $Id$
*/
#include "config.h"
#include <sys/types.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dumbnet.h"
#include "aton.h"
#include "mod.h"
void
eth_usage(void)
{
fprintf(stderr, "Usage: dnet eth [type|src|dst <value>] ... \n");
exit(1);
}
int
eth_main(int argc, char *argv[])
{
struct eth_hdr *eth;
struct addr addr;
u_char *p, buf[ETH_LEN_MAX]; /* XXX */
char *name, *value;
int c, len;
eth = (struct eth_hdr *)buf;
memset(eth, 0, sizeof(*eth));
eth->eth_type = htons(ETH_TYPE_IP);
for (c = 1; c + 1 < argc; c += 2) {
name = argv[c];
value = argv[c + 1];
if (strcmp(name, "type") == 0) {
if (type_aton(value, ð->eth_type) < 0)
eth_usage();
} else if (strcmp(name, "src") == 0) {
if (addr_aton(value, &addr) < 0)
eth_usage();
memcpy(ð->eth_src, &addr.addr_eth, ETH_ADDR_LEN);
} else if (strcmp(name, "dst") == 0) {
if (addr_aton(value, &addr) < 0)
eth_usage();
memcpy(ð->eth_dst, &addr.addr_eth, ETH_ADDR_LEN);
} else
eth_usage();
}
argc -= c;
argv += c;
if (argc != 0)
eth_usage();
if (isatty(STDIN_FILENO))
errx(1, "can't read Ethernet payload from tty");
p = buf + ETH_HDR_LEN;
len = sizeof(buf) - (p - buf);
while ((c = read(STDIN_FILENO, p, len)) > 0) {
p += c;
len -= c;
}
len = p - buf;
if (write(STDOUT_FILENO, buf, len) != len)
err(1, "write");
return (0);
}
struct mod mod_eth = {
"eth",
MOD_TYPE_ENCAP,
eth_main
};
|