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137 lines
3.3 KiB
137 lines
3.3 KiB
/* |
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* IPv6 Hop Limit matching module |
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* Maciej Soltysiak <solt@dns.toxicfilms.tv> |
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* Based on HW's ttl match |
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* This program is released under the terms of GNU GPL |
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* Cleanups by Stephane Ouellette <ouellettes@videotron.ca> |
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*/ |
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#include <stdio.h> |
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#include <xtables.h> |
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#include <linux/netfilter_ipv6/ip6t_hl.h> |
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enum { |
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O_HL_EQ = 0, |
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O_HL_LT, |
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O_HL_GT, |
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F_HL_EQ = 1 << O_HL_EQ, |
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F_HL_LT = 1 << O_HL_LT, |
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F_HL_GT = 1 << O_HL_GT, |
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F_ANY = F_HL_EQ | F_HL_LT | F_HL_GT, |
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}; |
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static void hl_help(void) |
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{ |
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printf( |
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"hl match options:\n" |
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"[!] --hl-eq value Match hop limit value\n" |
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" --hl-lt value Match HL < value\n" |
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" --hl-gt value Match HL > value\n"); |
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} |
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static void hl_parse(struct xt_option_call *cb) |
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{ |
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struct ip6t_hl_info *info = cb->data; |
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xtables_option_parse(cb); |
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switch (cb->entry->id) { |
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case O_HL_EQ: |
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info->mode = cb->invert ? IP6T_HL_NE : IP6T_HL_EQ; |
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break; |
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case O_HL_LT: |
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info->mode = IP6T_HL_LT; |
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break; |
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case O_HL_GT: |
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info->mode = IP6T_HL_GT; |
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break; |
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} |
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} |
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static void hl_check(struct xt_fcheck_call *cb) |
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{ |
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if (!(cb->xflags & F_ANY)) |
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xtables_error(PARAMETER_PROBLEM, |
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"HL match: You must specify one of " |
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"`--hl-eq', `--hl-lt', `--hl-gt'"); |
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} |
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static void hl_print(const void *ip, const struct xt_entry_match *match, |
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int numeric) |
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{ |
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static const char *const op[] = { |
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[IP6T_HL_EQ] = "==", |
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[IP6T_HL_NE] = "!=", |
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[IP6T_HL_LT] = "<", |
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[IP6T_HL_GT] = ">" }; |
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const struct ip6t_hl_info *info = |
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(struct ip6t_hl_info *) match->data; |
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printf(" HL match HL %s %u", op[info->mode], info->hop_limit); |
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} |
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static void hl_save(const void *ip, const struct xt_entry_match *match) |
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{ |
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static const char *const op[] = { |
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[IP6T_HL_EQ] = "--hl-eq", |
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[IP6T_HL_NE] = "! --hl-eq", |
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[IP6T_HL_LT] = "--hl-lt", |
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[IP6T_HL_GT] = "--hl-gt" }; |
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const struct ip6t_hl_info *info = |
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(struct ip6t_hl_info *) match->data; |
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printf(" %s %u", op[info->mode], info->hop_limit); |
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} |
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static const char *const op[] = { |
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[IP6T_HL_EQ] = "", |
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[IP6T_HL_NE] = "!= ", |
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[IP6T_HL_LT] = "lt ", |
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[IP6T_HL_GT] = "gt " |
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}; |
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static int hl_xlate(struct xt_xlate *xl, |
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const struct xt_xlate_mt_params *params) |
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{ |
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const struct ip6t_hl_info *info = |
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(struct ip6t_hl_info *) params->match->data; |
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xt_xlate_add(xl, "ip6 hoplimit %s%u", op[info->mode], info->hop_limit); |
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return 1; |
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} |
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#define s struct ip6t_hl_info |
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static const struct xt_option_entry hl_opts[] = { |
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{.name = "hl-lt", .id = O_HL_LT, .excl = F_ANY, .type = XTTYPE_UINT8, |
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.flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit)}, |
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{.name = "hl-gt", .id = O_HL_GT, .excl = F_ANY, .type = XTTYPE_UINT8, |
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.flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit)}, |
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{.name = "hl-eq", .id = O_HL_EQ, .excl = F_ANY, .type = XTTYPE_UINT8, |
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.flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hop_limit)}, |
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{.name = "hl", .id = O_HL_EQ, .excl = F_ANY, .type = XTTYPE_UINT8, |
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.flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit)}, |
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XTOPT_TABLEEND, |
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}; |
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#undef s |
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static struct xtables_match hl_mt6_reg = { |
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.name = "hl", |
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.version = XTABLES_VERSION, |
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.family = NFPROTO_IPV6, |
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.size = XT_ALIGN(sizeof(struct ip6t_hl_info)), |
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.userspacesize = XT_ALIGN(sizeof(struct ip6t_hl_info)), |
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.help = hl_help, |
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.print = hl_print, |
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.save = hl_save, |
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.x6_parse = hl_parse, |
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.x6_fcheck = hl_check, |
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.x6_options = hl_opts, |
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.xlate = hl_xlate, |
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}; |
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void _init(void) |
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{ |
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xtables_register_match(&hl_mt6_reg); |
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}
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