| /* |
| * IPv6 Hop Limit Target module |
| * Maciej Soltysiak <solt@dns.toxicfilms.tv> |
| * Based on HW's ttl target |
| * This program is distributed under the terms of GNU GPL |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <ip6tables.h> |
| |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| #include <linux/netfilter_ipv6/ip6t_HL.h> |
| |
| #define IP6T_HL_USED 1 |
| |
| static void init(struct ip6t_entry_target *t, unsigned int *nfcache) |
| { |
| } |
| |
| static void help(void) |
| { |
| printf( |
| "HL target v%s options\n" |
| " --hl-set value Set HL to <value>\n" |
| " --hl-dec value Decrement HL by <value>\n" |
| " --hl-inc value Increment HL by <value>\n" |
| , IPTABLES_VERSION); |
| } |
| |
| static int parse(int c, char **argv, int invert, unsigned int *flags, |
| const struct ip6t_entry *entry, |
| struct ip6t_entry_target **target) |
| { |
| struct ip6t_HL_info *info = (struct ip6t_HL_info *) (*target)->data; |
| u_int8_t value; |
| |
| if (*flags & IP6T_HL_USED) { |
| exit_error(PARAMETER_PROBLEM, |
| "Can't specify HL option twice"); |
| } |
| |
| if (!optarg) |
| exit_error(PARAMETER_PROBLEM, |
| "HL: You must specify a value"); |
| |
| if (check_inverse(optarg, &invert, NULL, 0)) |
| exit_error(PARAMETER_PROBLEM, |
| "HL: unexpected `!'"); |
| |
| value = atoi(optarg); |
| |
| switch (c) { |
| |
| case '1': |
| info->mode = IP6T_HL_SET; |
| break; |
| |
| case '2': |
| if (value == 0) { |
| exit_error(PARAMETER_PROBLEM, |
| "HL: decreasing by 0?"); |
| } |
| |
| info->mode = IP6T_HL_DEC; |
| break; |
| |
| case '3': |
| if (value == 0) { |
| exit_error(PARAMETER_PROBLEM, |
| "HL: increasing by 0?"); |
| } |
| |
| info->mode = IP6T_HL_INC; |
| break; |
| |
| default: |
| return 0; |
| |
| } |
| |
| info->hop_limit = value; |
| *flags |= IP6T_HL_USED; |
| |
| return 1; |
| } |
| |
| static void final_check(unsigned int flags) |
| { |
| if (!(flags & IP6T_HL_USED)) |
| exit_error(PARAMETER_PROBLEM, |
| "HL: You must specify an action"); |
| } |
| |
| static void save(const struct ip6t_ip6 *ip, |
| const struct ip6t_entry_target *target) |
| { |
| const struct ip6t_HL_info *info = |
| (struct ip6t_HL_info *) target->data; |
| |
| switch (info->mode) { |
| case IP6T_HL_SET: |
| printf("--hl-set "); |
| break; |
| case IP6T_HL_DEC: |
| printf("--hl-dec "); |
| break; |
| |
| case IP6T_HL_INC: |
| printf("--hl-inc "); |
| break; |
| } |
| printf("%u ", info->hop_limit); |
| } |
| |
| static void print(const struct ip6t_ip6 *ip, |
| const struct ip6t_entry_target *target, int numeric) |
| { |
| const struct ip6t_HL_info *info = |
| (struct ip6t_HL_info *) target->data; |
| |
| printf("HL "); |
| switch (info->mode) { |
| case IP6T_HL_SET: |
| printf("set to "); |
| break; |
| case IP6T_HL_DEC: |
| printf("decrement by "); |
| break; |
| case IP6T_HL_INC: |
| printf("increment by "); |
| break; |
| } |
| printf("%u ", info->hop_limit); |
| } |
| |
| static struct option opts[] = { |
| { "hl-set", 1, 0, '1' }, |
| { "hl-dec", 1, 0, '2' }, |
| { "hl-inc", 1, 0, '3' }, |
| { 0 } |
| }; |
| |
| static |
| struct ip6tables_target 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_target6(&HL); |
| } |