1
2/*
3 * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <stdbool.h>
11#include <stdio.h>
12#include <xtables.h>
13#include <linux/netfilter/xt_SYNPROXY.h>
14
15enum {
16	O_SACK_PERM = 0,
17	O_TIMESTAMP,
18	O_WSCALE,
19	O_MSS,
20	O_ECN,
21};
22
23static void SYNPROXY_help(void)
24{
25	printf(
26"SYNPROXY target options:\n"
27"  --sack-perm                        Set SACK_PERM\n"
28"  --timestamp                        Set TIMESTAMP\n"
29"  --wscale value                     Set window scaling factor\n"
30"  --mss value                        Set MSS value\n"
31"  --ecn                              Set ECN\n");
32}
33
34static const struct xt_option_entry SYNPROXY_opts[] = {
35	{.name = "sack-perm", .id = O_SACK_PERM, .type = XTTYPE_NONE, },
36	{.name = "timestamp", .id = O_TIMESTAMP, .type = XTTYPE_NONE, },
37	{.name = "wscale",    .id = O_WSCALE,    .type = XTTYPE_UINT32, },
38	{.name = "mss",       .id = O_MSS,       .type = XTTYPE_UINT32, },
39	{.name = "ecn",       .id = O_ECN,	 .type = XTTYPE_NONE, },
40	XTOPT_TABLEEND,
41};
42
43static void SYNPROXY_parse(struct xt_option_call *cb)
44{
45	struct xt_synproxy_info *info = cb->data;
46
47	xtables_option_parse(cb);
48	switch (cb->entry->id) {
49	case O_SACK_PERM:
50		info->options |= XT_SYNPROXY_OPT_SACK_PERM;
51		break;
52	case O_TIMESTAMP:
53		info->options |= XT_SYNPROXY_OPT_TIMESTAMP;
54		break;
55	case O_WSCALE:
56		info->options |= XT_SYNPROXY_OPT_WSCALE;
57		info->wscale = cb->val.u32;
58		break;
59	case O_MSS:
60		info->options |= XT_SYNPROXY_OPT_MSS;
61		info->mss = cb->val.u32;
62		break;
63	case O_ECN:
64		info->options |= XT_SYNPROXY_OPT_ECN;
65		break;
66	}
67}
68
69static void SYNPROXY_check(struct xt_fcheck_call *cb)
70{
71}
72
73static void SYNPROXY_print(const void *ip, const struct xt_entry_target *target,
74                           int numeric)
75{
76	const struct xt_synproxy_info *info =
77		(const struct xt_synproxy_info *)target->data;
78
79	printf(" SYNPROXY ");
80	if (info->options & XT_SYNPROXY_OPT_SACK_PERM)
81		printf("sack-perm ");
82	if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)
83		printf("timestamp ");
84	if (info->options & XT_SYNPROXY_OPT_WSCALE)
85		printf("wscale %u ", info->wscale);
86	if (info->options & XT_SYNPROXY_OPT_MSS)
87		printf("mss %u ", info->mss);
88	if (info->options & XT_SYNPROXY_OPT_ECN)
89		printf("ecn ");
90}
91
92static void SYNPROXY_save(const void *ip, const struct xt_entry_target *target)
93{
94	const struct xt_synproxy_info *info =
95		(const struct xt_synproxy_info *)target->data;
96
97	if (info->options & XT_SYNPROXY_OPT_SACK_PERM)
98		printf(" --sack-perm");
99	if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)
100		printf(" --timestamp");
101	if (info->options & XT_SYNPROXY_OPT_WSCALE)
102		printf(" --wscale %u", info->wscale);
103	if (info->options & XT_SYNPROXY_OPT_MSS)
104		printf(" --mss %u", info->mss);
105	if (info->options & XT_SYNPROXY_OPT_ECN)
106		printf(" --ecn");
107}
108
109static struct xtables_target synproxy_tg_reg = {
110	.family        = NFPROTO_UNSPEC,
111	.name          = "SYNPROXY",
112	.version       = XTABLES_VERSION,
113	.revision      = 0,
114	.size          = XT_ALIGN(sizeof(struct xt_synproxy_info)),
115	.userspacesize = XT_ALIGN(sizeof(struct xt_synproxy_info)),
116	.help          = SYNPROXY_help,
117	.print         = SYNPROXY_print,
118	.save          = SYNPROXY_save,
119	.x6_parse      = SYNPROXY_parse,
120	.x6_fcheck     = SYNPROXY_check,
121	.x6_options    = SYNPROXY_opts,
122};
123
124void _init(void)
125{
126	xtables_register_target(&synproxy_tg_reg);
127}
128