1
2 /*
3 * Copyright (c) 2013 Patrick McHardy <[email protected]>
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
15 enum {
16 O_SACK_PERM = 0,
17 O_TIMESTAMP,
18 O_WSCALE,
19 O_MSS,
20 O_ECN,
21 };
22
SYNPROXY_help(void)23 static 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
34 static 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
SYNPROXY_parse(struct xt_option_call * cb)43 static 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
SYNPROXY_check(struct xt_fcheck_call * cb)69 static void SYNPROXY_check(struct xt_fcheck_call *cb)
70 {
71 }
72
SYNPROXY_print(const void * ip,const struct xt_entry_target * target,int numeric)73 static 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
SYNPROXY_save(const void * ip,const struct xt_entry_target * target)92 static 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
SYNPROXY_xlate(struct xt_xlate * xl,const struct xt_xlate_tg_params * params)109 static int SYNPROXY_xlate(struct xt_xlate *xl,
110 const struct xt_xlate_tg_params *params)
111 {
112 const struct xt_synproxy_info *info =
113 (const struct xt_synproxy_info *)params->target->data;
114
115 xt_xlate_add(xl, "synproxy ");
116
117 if (info->options & XT_SYNPROXY_OPT_SACK_PERM)
118 xt_xlate_add(xl, "sack-perm ");
119 if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)
120 xt_xlate_add(xl, "timestamp ");
121 if (info->options & XT_SYNPROXY_OPT_WSCALE)
122 xt_xlate_add(xl, "wscale %u ", info->wscale);
123 if (info->options & XT_SYNPROXY_OPT_MSS)
124 xt_xlate_add(xl, "mss %u ", info->mss);
125 if (info->options & XT_SYNPROXY_OPT_ECN)
126 xt_xlate_add(xl, "ecn ");
127
128 return 1;
129 }
130
131 static struct xtables_target synproxy_tg_reg = {
132 .family = NFPROTO_UNSPEC,
133 .name = "SYNPROXY",
134 .version = XTABLES_VERSION,
135 .revision = 0,
136 .size = XT_ALIGN(sizeof(struct xt_synproxy_info)),
137 .userspacesize = XT_ALIGN(sizeof(struct xt_synproxy_info)),
138 .help = SYNPROXY_help,
139 .print = SYNPROXY_print,
140 .save = SYNPROXY_save,
141 .x6_parse = SYNPROXY_parse,
142 .x6_fcheck = SYNPROXY_check,
143 .x6_options = SYNPROXY_opts,
144 .xlate = SYNPROXY_xlate,
145 };
146
_init(void)147 void _init(void)
148 {
149 xtables_register_target(&synproxy_tg_reg);
150 }
151