Home | History | Annotate | Download | only in extensions 
      1 
      2 /*
      3  * Copyright (c) 2013 Patrick McHardy <kaber (at) 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 
     15 enum {
     16 	O_SACK_PERM = 0,
     17 	O_TIMESTAMP,
     18 	O_WSCALE,
     19 	O_MSS,
     20 	O_ECN,
     21 };
     22 
     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 
     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 
     69 static void SYNPROXY_check(struct xt_fcheck_call *cb)
     70 {
     71 }
     72 
     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 
     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 
    109 static 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 
    124 void _init(void)
    125 {
    126 	xtables_register_target(&synproxy_tg_reg);
    127 }
    128