libxt_connmark.c revision 73866357e4a7a0fdc1b293bf8863fee2bd56da9e 
1/* Shared library add-on to iptables to add connmark matching support.
2 *
3 * (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
4 * by Henrik Nordstrom <hno@marasystems.com>
5 *
6 * Version 1.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 */
22#include <stdbool.h>
23#include <stdio.h>
24#include <netdb.h>
25#include <string.h>
26#include <stdlib.h>
27#include <getopt.h>
28
29#include <xtables.h>
30#include <linux/netfilter/xt_connmark.h>
31
32struct xt_connmark_info {
33	unsigned long mark, mask;
34	uint8_t invert;
35};
36
37enum {
38	F_MARK = 1 << 0,
39};
40
41static void connmark_mt_help(void)
42{
43	printf(
44"connmark match options:\n"
45"[!] --mark value[/mask]    Match ctmark value with optional mask\n");
46}
47
48static const struct option connmark_mt_opts[] = {
49	{.name = "mark", .has_arg = true, .val = '1'},
50	XT_GETOPT_TABLEEND,
51};
52
53static int
54connmark_mt_parse(int c, char **argv, int invert, unsigned int *flags,
55                  const void *entry, struct xt_entry_match **match)
56{
57	struct xt_connmark_mtinfo1 *info = (void *)(*match)->data;
58	unsigned int mark, mask = UINT32_MAX;
59	char *end;
60
61	switch (c) {
62	case '1': /* --mark */
63		xtables_param_act(XTF_ONLY_ONCE, "connmark", "--mark", *flags & F_MARK);
64		if (!xtables_strtoui(optarg, &end, &mark, 0, UINT32_MAX))
65			xtables_param_act(XTF_BAD_VALUE, "connmark", "--mark", optarg);
66		if (*end == '/')
67			if (!xtables_strtoui(end + 1, &end, &mask, 0, UINT32_MAX))
68				xtables_param_act(XTF_BAD_VALUE, "connmark", "--mark", optarg);
69		if (*end != '\0')
70			xtables_param_act(XTF_BAD_VALUE, "connmark", "--mark", optarg);
71
72		if (invert)
73			info->invert = true;
74		info->mark = mark;
75		info->mask = mask;
76		*flags    |= F_MARK;
77		return true;
78	}
79	return false;
80}
81
82static int
83connmark_parse(int c, char **argv, int invert, unsigned int *flags,
84               const void *entry, struct xt_entry_match **match)
85{
86	struct xt_connmark_info *markinfo = (struct xt_connmark_info *)(*match)->data;
87
88	switch (c) {
89		char *end;
90	case '1':
91		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
92
93		markinfo->mark = strtoul(optarg, &end, 0);
94		markinfo->mask = 0xffffffffUL;
95
96		if (*end == '/')
97			markinfo->mask = strtoul(end+1, &end, 0);
98
99		if (*end != '\0' || end == optarg)
100			xtables_error(PARAMETER_PROBLEM, "Bad MARK value \"%s\"", optarg);
101		if (invert)
102			markinfo->invert = 1;
103		*flags = 1;
104		break;
105	}
106	return 1;
107}
108
109static void print_mark(unsigned int mark, unsigned int mask)
110{
111	if (mask != 0xffffffffU)
112		printf(" 0x%x/0x%x", mark, mask);
113	else
114		printf(" 0x%x", mark);
115}
116
117static void connmark_mt_check(unsigned int flags)
118{
119	if (flags == 0)
120		xtables_error(PARAMETER_PROBLEM,
121		           "connmark: The --mark option is required");
122}
123
124static void
125connmark_print(const void *ip, const struct xt_entry_match *match, int numeric)
126{
127	const struct xt_connmark_info *info = (const void *)match->data;
128
129	printf(" CONNMARK match ");
130	if (info->invert)
131		printf("!");
132	print_mark(info->mark, info->mask);
133}
134
135static void
136connmark_mt_print(const void *ip, const struct xt_entry_match *match, int numeric)
137{
138	const struct xt_connmark_mtinfo1 *info = (const void *)match->data;
139
140	printf(" connmark match ");
141	if (info->invert)
142		printf("!");
143	print_mark(info->mark, info->mask);
144}
145
146static void connmark_save(const void *ip, const struct xt_entry_match *match)
147{
148	const struct xt_connmark_info *info = (const void *)match->data;
149
150	if (info->invert)
151		printf(" !");
152
153	printf(" --mark");
154	print_mark(info->mark, info->mask);
155}
156
157static void
158connmark_mt_save(const void *ip, const struct xt_entry_match *match)
159{
160	const struct xt_connmark_mtinfo1 *info = (const void *)match->data;
161
162	if (info->invert)
163		printf(" !");
164
165	printf(" --mark");
166	print_mark(info->mark, info->mask);
167}
168
169static struct xtables_match connmark_mt_reg[] = {
170	{
171		.family        = NFPROTO_UNSPEC,
172		.name          = "connmark",
173		.revision      = 0,
174		.version       = XTABLES_VERSION,
175		.size          = XT_ALIGN(sizeof(struct xt_connmark_info)),
176		.userspacesize = XT_ALIGN(sizeof(struct xt_connmark_info)),
177		.help          = connmark_mt_help,
178		.parse         = connmark_parse,
179		.final_check   = connmark_mt_check,
180		.print         = connmark_print,
181		.save          = connmark_save,
182		.extra_opts    = connmark_mt_opts,
183	},
184	{
185		.version       = XTABLES_VERSION,
186		.name          = "connmark",
187		.revision      = 1,
188		.family        = NFPROTO_UNSPEC,
189		.size          = XT_ALIGN(sizeof(struct xt_connmark_mtinfo1)),
190		.userspacesize = XT_ALIGN(sizeof(struct xt_connmark_mtinfo1)),
191		.help          = connmark_mt_help,
192		.parse         = connmark_mt_parse,
193		.final_check   = connmark_mt_check,
194		.print         = connmark_mt_print,
195		.save          = connmark_mt_save,
196		.extra_opts    = connmark_mt_opts,
197	},
198};
199
200void _init(void)
201{
202	xtables_register_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg));
203}
204