summaryrefslogtreecommitdiffstats
path: root/extensions/libebt_log.c
blob: dc2357c022bf03229d8722fb4062cf3956f4c205 (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
/*
 * Bart De Schuymer <bdschuym@pandora.be>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Giuseppe Longo <giuseppelng@gmail.com> adapted the original code to the
 * xtables-compat environment in 2015.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <string.h>
#include <xtables.h>
#include <linux/netfilter_bridge/ebt_log.h>

#define LOG_DEFAULT_LEVEL LOG_INFO

struct code {
	char *c_name;
	int c_val;
};

static struct code eight_priority[] = {
	{ "emerg", LOG_EMERG },
	{ "alert", LOG_ALERT },
	{ "crit", LOG_CRIT },
	{ "error", LOG_ERR },
	{ "warning", LOG_WARNING },
	{ "notice", LOG_NOTICE },
	{ "info", LOG_INFO },
	{ "debug", LOG_DEBUG }
};

enum {
	/* first three must correspond with bit pos in respective EBT_LOG_* */
	O_LOG_IP = 0,
	O_LOG_ARP = 1,
	O_LOG_IP6 = 3,
	O_LOG_PREFIX,
	O_LOG_LEVEL,
	O_LOG_LOG,
};

static const struct xt_option_entry brlog_opts[] = {
	{ .name = "log-prefix", .id = O_LOG_PREFIX, .type = XTTYPE_STRING,
	  .flags = XTOPT_PUT, XTOPT_POINTER(struct ebt_log_info, prefix) },
	{ .name = "log-level", .id = O_LOG_LEVEL, .type = XTTYPE_SYSLOGLEVEL,
	  .flags = XTOPT_PUT, XTOPT_POINTER(struct ebt_log_info, loglevel) },
	{ .name = "log-arp",	.id = O_LOG_ARP,	.type = XTTYPE_NONE },
	{ .name = "log-ip",	.id = O_LOG_IP,		.type = XTTYPE_NONE },
	{ .name = "log",	.id = O_LOG_LOG,	.type = XTTYPE_NONE },
	{ .name = "log-ip6",	.id = O_LOG_IP6,	.type = XTTYPE_NONE },
	XTOPT_TABLEEND,
};

static void brlog_help(void)
{
	int i;

	printf(
"log options:\n"
"--log               : use this if you're not specifying anything\n"
"--log-level level   : level = [1-8] or a string\n"
"--log-prefix prefix : max. %d chars.\n"
"--log-ip            : put ip info. in the log for ip packets\n"
"--log-arp           : put (r)arp info. in the log for (r)arp packets\n"
"--log-ip6           : put ip6 info. in the log for ip6 packets\n"
	, EBT_LOG_PREFIX_SIZE - 1);
	for (i = 0; i < 8; i++)
		printf("%d = %s\n", eight_priority[i].c_val,
				    eight_priority[i].c_name);
}

static void brlog_init(struct xt_entry_target *t)
{
	struct ebt_log_info *loginfo = (struct ebt_log_info *)t->data;

	loginfo->loglevel = LOG_NOTICE;
}

static void brlog_parse(struct xt_option_call *cb)
{
	struct ebt_log_info *loginfo = cb->data;

	xtables_option_parse(cb);
	switch (cb->entry->id) {
	case O_LOG_IP:
	case O_LOG_ARP:
	case O_LOG_IP6:
		loginfo->bitmask |= 1 << cb->entry->id;
		break;
	}
}

static void brlog_print(const void *ip, const struct xt_entry_target *target,
			int numeric)
{
	struct ebt_log_info *loginfo = (struct ebt_log_info *)target->data;

	printf("--log-level %s", eight_priority[loginfo->loglevel].c_name);

	if (loginfo->prefix[0])
		printf(" --log-prefix \"%s\"", loginfo->prefix);

	if (loginfo->bitmask & EBT_LOG_IP)
		printf(" --log-ip");
	if (loginfo->bitmask & EBT_LOG_ARP)
		printf(" --log-arp");
	if (loginfo->bitmask & EBT_LOG_IP6)
		printf(" --log-ip6");
	printf(" ");
}

static int brlog_xlate(struct xt_xlate *xl,
		       const struct xt_xlate_tg_params *params)
{
	const struct ebt_log_info *loginfo = (const void *)params->target->data;

	xt_xlate_add(xl, "log");
	if (loginfo->prefix[0])
		xt_xlate_add(xl, " prefix \"%s\"", loginfo->prefix);

	if (loginfo->loglevel != LOG_DEFAULT_LEVEL)
		xt_xlate_add(xl, " level %s", eight_priority[loginfo->loglevel].c_name);

	/* ebt_log always decodes MAC header, nft_log always decodes upper header -
	 * so set flags ether and ignore EBT_LOG_IP, EBT_LOG_ARP and EBT_LOG_IP6 */
	xt_xlate_add(xl, " flags ether ");

	return 1;
}

static struct xtables_target brlog_target = {
	.name		= "log",
	.revision	= 0,
	.ext_flags	= XTABLES_EXT_WATCHER,
	.version	= XTABLES_VERSION,
	.family		= NFPROTO_BRIDGE,
	.size		= XT_ALIGN(sizeof(struct ebt_log_info)),
	.userspacesize	= XT_ALIGN(sizeof(struct ebt_log_info)),
	.init		= brlog_init,
	.help		= brlog_help,
	.x6_parse	= brlog_parse,
	.print		= brlog_print,
	.xlate		= brlog_xlate,
	.x6_options	= brlog_opts,
};

void _init(void)
{
	xtables_register_target(&brlog_target);
}