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126 lines
2.8 KiB
126 lines
2.8 KiB
/* Shared library add-on to iptables for the TTL target |
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* (C) 2000 by Harald Welte <laforge@gnumonks.org> |
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* |
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* This program is distributed under the terms of GNU GPL |
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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_ipv4/ipt_TTL.h> |
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enum { |
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O_TTL_SET = 0, |
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O_TTL_INC, |
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O_TTL_DEC, |
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F_TTL_SET = 1 << O_TTL_SET, |
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F_TTL_INC = 1 << O_TTL_INC, |
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F_TTL_DEC = 1 << O_TTL_DEC, |
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F_ANY = F_TTL_SET | F_TTL_INC | F_TTL_DEC, |
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}; |
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#define s struct ipt_TTL_info |
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static const struct xt_option_entry TTL_opts[] = { |
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{.name = "ttl-set", .type = XTTYPE_UINT8, .id = O_TTL_SET, |
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.excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl)}, |
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{.name = "ttl-dec", .type = XTTYPE_UINT8, .id = O_TTL_DEC, |
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.excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl), |
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.min = 1}, |
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{.name = "ttl-inc", .type = XTTYPE_UINT8, .id = O_TTL_INC, |
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.excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl), |
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.min = 1}, |
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XTOPT_TABLEEND, |
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}; |
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#undef s |
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static void TTL_help(void) |
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{ |
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printf( |
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"TTL target options\n" |
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" --ttl-set value Set TTL to <value 0-255>\n" |
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" --ttl-dec value Decrement TTL by <value 1-255>\n" |
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" --ttl-inc value Increment TTL by <value 1-255>\n"); |
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} |
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static void TTL_parse(struct xt_option_call *cb) |
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{ |
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struct ipt_TTL_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_TTL_SET: |
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info->mode = IPT_TTL_SET; |
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break; |
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case O_TTL_DEC: |
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info->mode = IPT_TTL_DEC; |
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break; |
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case O_TTL_INC: |
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info->mode = IPT_TTL_INC; |
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break; |
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} |
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} |
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static void TTL_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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"TTL: You must specify an action"); |
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} |
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static void TTL_save(const void *ip, const struct xt_entry_target *target) |
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{ |
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const struct ipt_TTL_info *info = |
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(struct ipt_TTL_info *) target->data; |
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switch (info->mode) { |
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case IPT_TTL_SET: |
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printf(" --ttl-set"); |
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break; |
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case IPT_TTL_DEC: |
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printf(" --ttl-dec"); |
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break; |
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case IPT_TTL_INC: |
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printf(" --ttl-inc"); |
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break; |
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} |
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printf(" %u", info->ttl); |
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} |
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static void TTL_print(const void *ip, const struct xt_entry_target *target, |
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int numeric) |
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{ |
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const struct ipt_TTL_info *info = |
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(struct ipt_TTL_info *) target->data; |
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printf(" TTL "); |
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switch (info->mode) { |
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case IPT_TTL_SET: |
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printf("set to"); |
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break; |
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case IPT_TTL_DEC: |
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printf("decrement by"); |
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break; |
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case IPT_TTL_INC: |
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printf("increment by"); |
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break; |
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} |
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printf(" %u", info->ttl); |
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} |
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static struct xtables_target ttl_tg_reg = { |
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.name = "TTL", |
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.version = XTABLES_VERSION, |
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.family = NFPROTO_IPV4, |
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.size = XT_ALIGN(sizeof(struct ipt_TTL_info)), |
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.userspacesize = XT_ALIGN(sizeof(struct ipt_TTL_info)), |
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.help = TTL_help, |
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.print = TTL_print, |
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.save = TTL_save, |
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.x6_parse = TTL_parse, |
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.x6_fcheck = TTL_check, |
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.x6_options = TTL_opts, |
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}; |
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void _init(void) |
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{ |
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xtables_register_target(&ttl_tg_reg); |
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}
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