| /* |
| * IPv6 Hop Limit matching module |
| * Maciej Soltysiak <solt@dns.toxicfilms.tv> |
| * Based on HW's ttl match |
| * This program is released under the terms of GNU GPL |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <getopt.h> |
| #include <ip6tables.h> |
| |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| #include <linux/netfilter_ipv6/ip6t_hl.h> |
| |
| static void help(void) |
| { |
| printf( |
| "HL match v%s options:\n" |
| " --hl-eq value Match hop limit value\n" |
| " --hl-lt value Match HL < value\n" |
| " --hl-gt value Match HL > value\n" |
| , IPTABLES_VERSION); |
| } |
| |
| static void init(struct ip6t_entry_match *m, unsigned int *nfcache) |
| { |
| /* caching not yet implemented */ |
| *nfcache |= NFC_UNKNOWN; |
| } |
| |
| static int parse(int c, char **argv, int invert, unsigned int *flags, |
| const struct ip6t_entry *entry, unsigned int *nfcache, |
| struct ip6t_entry_match **match) |
| { |
| struct ip6t_hl_info *info = (struct ip6t_hl_info *) (*match)->data; |
| u_int8_t value; |
| |
| check_inverse(optarg, &invert, &optind, 0); |
| value = atoi(argv[optind-1]); |
| |
| if (*flags) |
| exit_error(PARAMETER_PROBLEM, |
| "Can't specify HL option twice"); |
| |
| if (!optarg) |
| exit_error(PARAMETER_PROBLEM, |
| "hl: You must specify a value"); |
| switch (c) { |
| case '2': |
| if (invert) |
| info->mode = IP6T_HL_NE; |
| else |
| info->mode = IP6T_HL_EQ; |
| |
| /* is 0 allowed? */ |
| info->hop_limit = value; |
| *flags = 1; |
| |
| break; |
| case '3': |
| if (invert) |
| exit_error(PARAMETER_PROBLEM, |
| "hl: unexpected `!'"); |
| |
| info->mode = IP6T_HL_LT; |
| info->hop_limit = value; |
| *flags = 1; |
| |
| break; |
| case '4': |
| if (invert) |
| exit_error(PARAMETER_PROBLEM, |
| "hl: unexpected `!'"); |
| |
| info->mode = IP6T_HL_GT; |
| info->hop_limit = value; |
| *flags = 1; |
| |
| break; |
| default: |
| return 0; |
| |
| } |
| |
| return 1; |
| } |
| |
| static void final_check(unsigned int flags) |
| { |
| if (!flags) |
| exit_error(PARAMETER_PROBLEM, |
| "HL match: You must specify one of " |
| "`--hl-eq', `--hl-lt', `--hl-gt"); |
| } |
| |
| static void print(const struct ip6t_ip6 *ip, |
| const struct ip6t_entry_match *match, |
| int numeric) |
| { |
| const struct ip6t_hl_info *info = |
| (struct ip6t_hl_info *) match->data; |
| |
| printf("HL match "); |
| switch (info->mode) { |
| case IP6T_HL_EQ: |
| printf("HL == "); |
| break; |
| case IP6T_HL_NE: |
| printf("HL != "); |
| break; |
| case IP6T_HL_LT: |
| printf("HL < "); |
| break; |
| case IP6T_HL_GT: |
| printf("HL > "); |
| break; |
| } |
| printf("%u ", info->hop_limit); |
| } |
| |
| static void save(const struct ip6t_ip6 *ip, |
| const struct ip6t_entry_match *match) |
| { |
| const struct ip6t_hl_info *info = |
| (struct ip6t_hl_info *) match->data; |
| |
| switch (info->mode) { |
| case IP6T_HL_EQ: |
| printf("--hl-eq "); |
| break; |
| case IP6T_HL_NE: |
| printf("! --hl-eq "); |
| break; |
| case IP6T_HL_LT: |
| printf("--hl-lt "); |
| break; |
| case IP6T_HL_GT: |
| printf("--hl-gt "); |
| break; |
| default: |
| /* error */ |
| break; |
| } |
| printf("%u ", info->hop_limit); |
| } |
| |
| static struct option opts[] = { |
| { "hl", 1, 0, '2' }, |
| { "hl-eq", 1, 0, '2'}, |
| { "hl-lt", 1, 0, '3'}, |
| { "hl-gt", 1, 0, '4'}, |
| { 0 } |
| }; |
| |
| static |
| struct ip6tables_match hl = { |
| NULL, |
| "hl", |
| IPTABLES_VERSION, |
| IP6T_ALIGN(sizeof(struct ip6t_hl_info)), |
| IP6T_ALIGN(sizeof(struct ip6t_hl_info)), |
| &help, |
| &init, |
| &parse, |
| &final_check, |
| &print, |
| &save, |
| opts |
| }; |
| |
| |
| void _init(void) |
| { |
| register_match6(&hl); |
| } |