summaryrefslogtreecommitdiffstats
path: root/extensions/ebt_nflog.c
blob: 259bdb292cea6ae13db43247ef652ced955fcd24 (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
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
/* ebt_nflog
 *
 * Authors:
 * Peter Warasin <peter@endian.com>
 *
 *  February, 2008
 *
 * Based on:
 *  ebt_ulog.c, (C) 2004, Bart De Schuymer <bdschuym@pandora.be>
 *  libxt_NFLOG.c
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include "../include/ebtables_u.h"
#include <linux/netfilter_bridge/ebt_nflog.h>

enum {
	NFLOG_GROUP = 0x1,
	NFLOG_PREFIX = 0x2,
	NFLOG_RANGE = 0x4,
	NFLOG_THRESHOLD = 0x8,
	NFLOG_NFLOG = 0x16,
};

static struct option nflog_opts[] = {
	{"nflog-group", required_argument, NULL, NFLOG_GROUP},
	{"nflog-prefix", required_argument, NULL, NFLOG_PREFIX},
	{"nflog-range", required_argument, NULL, NFLOG_RANGE},
	{"nflog-threshold", required_argument, NULL, NFLOG_THRESHOLD},
	{"nflog", no_argument, NULL, NFLOG_NFLOG},
	{.name = NULL}
};

static void nflog_help()
{
	printf("nflog options:\n"
	       "--nflog               : use the default nflog parameters\n"
	       "--nflog-prefix prefix : Prefix string for log message\n"
	       "--nflog-group group   : NETLINK group used for logging\n"
	       "--nflog-range range   : Number of byte to copy\n"
	       "--nflog-threshold     : Message threshold of"
	       "in-kernel queue\n");
}

static void init(struct ebt_entry_watcher *watcher)
{
	struct ebt_nflog_info *info = (struct ebt_nflog_info *)watcher->data;

	info->prefix[0] = '\0';
	info->group = EBT_NFLOG_DEFAULT_GROUP;
	info->threshold = EBT_NFLOG_DEFAULT_THRESHOLD;
}

static int nflog_parse(int c, char **argv, int argc,
		       const struct ebt_u_entry *entry, unsigned int *flags,
		       struct ebt_entry_watcher **watcher)
{
	struct ebt_nflog_info *info;
	unsigned int i;
	char *end;

	info = (struct ebt_nflog_info *)(*watcher)->data;
	switch (c) {
	case NFLOG_PREFIX:
		if (ebt_check_inverse2(optarg))
			goto inverse_invalid;
		ebt_check_option2(flags, NFLOG_PREFIX);
		if (strlen(optarg) > EBT_NFLOG_PREFIX_SIZE - 1)
			ebt_print_error("Prefix too long for nflog-prefix");
		strcpy(info->prefix, optarg);
		break;

	case NFLOG_GROUP:
		if (ebt_check_inverse2(optarg))
			goto inverse_invalid;
		ebt_check_option2(flags, NFLOG_GROUP);
		i = strtoul(optarg, &end, 10);
		if (*end != '\0')
			ebt_print_error2("--nflog-group must be a number!");
		if (i < 0)
			ebt_print_error2("--nflog-group can not be negative");
		info->group = i;
		break;

	case NFLOG_RANGE:
		if (ebt_check_inverse2(optarg))
			goto inverse_invalid;
		ebt_check_option2(flags, NFLOG_RANGE);
		i = strtoul(optarg, &end, 10);
		if (*end != '\0')
			ebt_print_error2("--nflog-range must be a number!");
		if (i < 0)
			ebt_print_error2("--nflog-range can not be negative");
		info->len = i;
		break;

	case NFLOG_THRESHOLD:
		if (ebt_check_inverse2(optarg))
			goto inverse_invalid;
		ebt_check_option2(flags, NFLOG_THRESHOLD);
		i = strtoul(optarg, &end, 10);
		if (*end != '\0')
			ebt_print_error2("--nflog-threshold must be a number!");
		if (i < 0)
			ebt_print_error2
			    ("--nflog-threshold can not be negative");
		info->threshold = i;
		break;
	case NFLOG_NFLOG:
		if (ebt_check_inverse(optarg))
			goto inverse_invalid;
		ebt_check_option2(flags, NFLOG_NFLOG);
		break;

	default:
		return 0;
	}
	return 1;

 inverse_invalid:
	ebt_print_error("The use of '!' makes no sense for the nflog watcher");
	return 1;
}

static void nflog_final_check(const struct ebt_u_entry *entry,
			      const struct ebt_entry_watcher *watcher,
			      const char *name, unsigned int hookmask,
			      unsigned int time)
{
}

static void nflog_print(const struct ebt_u_entry *entry,
			const struct ebt_entry_watcher *watcher)
{
	struct ebt_nflog_info *info = (struct ebt_nflog_info *)watcher->data;

	if (info->prefix[0] != '\0')
		printf("--nflog-prefix \"%s\"", info->prefix);
	if (info->group)
		printf("--nflog-group %d ", info->group);
	if (info->len)
		printf("--nflog-range %d", info->len);
	if (info->threshold != EBT_NFLOG_DEFAULT_THRESHOLD)
		printf(" --nflog-threshold %d ", info->threshold);
}

static int nflog_compare(const struct ebt_entry_watcher *w1,
			 const struct ebt_entry_watcher *w2)
{
	struct ebt_nflog_info *info1 = (struct ebt_nflog_info *)w1->data;
	struct ebt_nflog_info *info2 = (struct ebt_nflog_info *)w2->data;

	if (info1->group != info2->group ||
	    info1->len != info2->len ||
	    info1->threshold != info2->threshold ||
	    strcmp(info1->prefix, info2->prefix))
		return 0;
	return 1;
}

static struct ebt_u_watcher nflog_watcher = {
	.name = "nflog",
	.size = sizeof(struct ebt_nflog_info),
	.help = nflog_help,
	.init = init,
	.parse = nflog_parse,
	.final_check = nflog_final_check,
	.print = nflog_print,
	.compare = nflog_compare,
	.extra_ops = nflog_opts,
};

void _init(void)
{
	ebt_register_watcher(&nflog_watcher);
}