summaryrefslogtreecommitdiffstats
path: root/extensions/libipt_connbytes.c
blob: abc37be033969a42b5c0de1ed9481aea0c4b63eb (plain)
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
/* Shared library add-on to iptables to add byte tracking support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <iptables.h>
#include <linux/netfilter_ipv4/ip_conntrack.h>
#include <linux/netfilter_ipv4/ipt_connbytes.h>

/* Function which prints out usage message. */
static void
help(void)
{
	printf(
"connbytes v%s options:\n"
" [!] --connbytes from:[to]\n"
"				Transfered byte range to match\n"
"\n", IPTABLES_VERSION);
}

static struct option opts[] = {
	{ "connbytes", 1, 0, '1' },
	{0}
};

/* Initialize the match. */
static void
init(struct ipt_entry_match *m, unsigned int *nfcache)
{
	/* Can't cache this */
	*nfcache |= NFC_UNKNOWN;
}

static void
parse_range(const char *arg, struct ipt_connbytes_info *si)
{
	char *colon,*p;

	si->from = strtol(arg,&colon,10);
	if (*colon != ':') 
		exit_error(PARAMETER_PROBLEM, "Bad range `%s'", arg);
	si->to = strtol(colon+1,&p,10);
	if (p == colon+1) {
		/* second number omited */
		si->to = 0xffffffff;
	}
	if (si->from > si->to)
		exit_error(PARAMETER_PROBLEM, "%lu should be less than %lu", si->from,si->to);
}

/* Function which parses command options; returns true if it
   ate an option */
static int
parse(int c, char **argv, int invert, unsigned int *flags,
      const struct ipt_entry *entry,
      unsigned int *nfcache,
      struct ipt_entry_match **match)
{
	struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)(*match)->data;
	int i;

	switch (c) {
	case '1':
		if (check_inverse(optarg, &invert, optind, 0))
			optind++;

		parse_range(argv[optind-1], sinfo);
		if (invert) {
			i = sinfo->from;
			sinfo->from = sinfo->to;
			sinfo->to = i;
		}
		*flags = 1;
		break;

	default:
		return 0;
	}

	return 1;
}

static void final_check(unsigned int flags)
{
	if (!flags)
		exit_error(PARAMETER_PROBLEM, "You must specify `--connbytes'");
}

/* Prints out the matchinfo. */
static void
print(const struct ipt_ip *ip,
      const struct ipt_entry_match *match,
      int numeric)
{
	struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)match->data;

	if (sinfo->from > sinfo->to) 
		printf("connbytes ! %lu:%lu",sinfo->to,sinfo->from);
	else
		printf("connbytes %lu:%lu",sinfo->from,sinfo->to);
}

/* Saves the matchinfo in parsable form to stdout. */
static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
{
	struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)match->data;

	if (sinfo->from > sinfo->to) 
		printf("! --connbytes %lu:%lu",sinfo->to,sinfo->from);
	else
		printf("--connbytes %lu:%lu",sinfo->from,sinfo->to);
}

static
struct iptables_match state
= { NULL,
    "connbytes",
    IPTABLES_VERSION,
    IPT_ALIGN(sizeof(struct ipt_connbytes_info)),
    IPT_ALIGN(sizeof(struct ipt_connbytes_info)),
    &help,
    &init,
    &parse,
    &final_check,
    &print,
    &save,
    opts
};

void _init(void)
{
	register_match(&state);
}