libipt_ttl.c revision d09b6d591ca7d7d7575cb6aa20384c9830f777ab
1ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project/* Shared library add-on to iptables to add TTL matching support 2ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project * (C) 2000 by Harald Welte <laforge@gnumonks.org> 3ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project * 4df143a5041f03a22808b59c76698770b74692815Selim Gurun * $Id$ 5ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project * 6ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project * This program is released under the terms of GNU GPL */ 7ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <stdbool.h> 8ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <stdio.h> 9ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <stdlib.h> 10ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <string.h> 11ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <getopt.h> 12ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <xtables.h> 13ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 14ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project#include <linux/netfilter_ipv4/ipt_ttl.h> 15ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 16ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Projectstatic void ttl_help(void) 17ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project{ 18ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project printf( 19ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project"ttl match options:\n" 20ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project" --ttl-eq value Match time to live value\n" 21ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project" --ttl-lt value Match TTL < value\n" 22ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project" --ttl-gt value Match TTL > value\n"); 23ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project} 24ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 25ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Projectstatic int ttl_parse(int c, char **argv, int invert, unsigned int *flags, 26ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project const void *entry, struct xt_entry_match **match) 2794442ad4107000e6d49f9b85a46a591495a57632Selim Gurun{ 28ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project struct ipt_ttl_info *info = (struct ipt_ttl_info *) (*match)->data; 29ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project unsigned int value; 30ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 31ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_check_inverse(optarg, &invert, &optind, 0, argv); 32ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 33ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project switch (c) { 34ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case '2': 35ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (!xtables_strtoui(optarg, NULL, &value, 0, UINT8_MAX)) 36ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_error(PARAMETER_PROBLEM, 37ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "ttl: Expected value between 0 and 255"); 38ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 39ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (invert) 40ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->mode = IPT_TTL_NE; 41ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project else 42ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->mode = IPT_TTL_EQ; 43ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 44ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project /* is 0 allowed? */ 45ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->ttl = value; 46ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project break; 47ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case '3': 4894442ad4107000e6d49f9b85a46a591495a57632Selim Gurun if (!xtables_strtoui(optarg, NULL, &value, 0, UINT8_MAX)) 4994442ad4107000e6d49f9b85a46a591495a57632Selim Gurun xtables_error(PARAMETER_PROBLEM, 5094442ad4107000e6d49f9b85a46a591495a57632Selim Gurun "ttl: Expected value between 0 and 255"); 51ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 52ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (invert) 53ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_error(PARAMETER_PROBLEM, 54ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "ttl: unexpected `!'"); 55ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 56ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->mode = IPT_TTL_LT; 57ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->ttl = value; 58ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project break; 59ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case '4': 60ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (!xtables_strtoui(optarg, NULL, &value, 0, UINT8_MAX)) 61ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_error(PARAMETER_PROBLEM, 62ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "ttl: Expected value between 0 and 255"); 63ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 64ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (invert) 65218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang xtables_error(PARAMETER_PROBLEM, 66ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "ttl: unexpected `!'"); 67ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 68ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->mode = IPT_TTL_GT; 69ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project info->ttl = value; 70ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project break; 71ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project } 72ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 73ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (*flags) 74ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_error(PARAMETER_PROBLEM, 75ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "Can't specify TTL option twice"); 76ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project *flags = 1; 77ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 78ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project return 1; 79ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project} 80ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 81ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Projectstatic void ttl_check(unsigned int flags) 82ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project{ 83ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project if (!flags) 84ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_error(PARAMETER_PROBLEM, 85ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "TTL match: You must specify one of " 86ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project "`--ttl-eq', `--ttl-lt', `--ttl-gt"); 87ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project} 88ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 89ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Projectstatic void ttl_print(const void *ip, const struct xt_entry_match *match, 90ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project int numeric) 91ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project{ 92ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project const struct ipt_ttl_info *info = 93ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project (struct ipt_ttl_info *) match->data; 94ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 95ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project printf("TTL match "); 96ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project switch (info->mode) { 97ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case IPT_TTL_EQ: 98ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project printf("TTL == "); 99ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project break; 100ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case IPT_TTL_NE: 101ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project printf("TTL != "); 102ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project break; 103ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project case IPT_TTL_LT: 104218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("TTL < "); 105df143a5041f03a22808b59c76698770b74692815Selim Gurun break; 106218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang case IPT_TTL_GT: 107218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("TTL > "); 108218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 109218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang } 110218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("%u ", info->ttl); 111218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang} 112218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang 113218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wangstatic void ttl_save(const void *ip, const struct xt_entry_match *match) 114218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang{ 115218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang const struct ipt_ttl_info *info = 116218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang (struct ipt_ttl_info *) match->data; 117218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang 118218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang switch (info->mode) { 119df143a5041f03a22808b59c76698770b74692815Selim Gurun case IPT_TTL_EQ: 120218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("--ttl-eq "); 121218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 122218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang case IPT_TTL_NE: 123df143a5041f03a22808b59c76698770b74692815Selim Gurun printf("! --ttl-eq "); 124218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 125218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang case IPT_TTL_LT: 126218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("--ttl-lt "); 127218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 128218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang case IPT_TTL_GT: 129218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang printf("--ttl-gt "); 130218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 131218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang default: 132218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang /* error */ 133218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang break; 134218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang } 135df143a5041f03a22808b59c76698770b74692815Selim Gurun printf("%u ", info->ttl); 136218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang} 137218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang 138218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wangstatic const struct option ttl_opts[] = { 139218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang {.name = "ttl", .has_arg = true, .val = '2'}, 140218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang {.name = "ttl-eq", .has_arg = true, .val = '2'}, 141218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang {.name = "ttl-lt", .has_arg = true, .val = '3'}, 142218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang {.name = "ttl-gt", .has_arg = true, .val = '4'}, 143218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang XT_GETOPT_TABLEEND, 144218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang}; 145218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang 146218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wangstatic struct xtables_match ttl_mt_reg = { 147218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang .name = "ttl", 148218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang .version = XTABLES_VERSION, 149218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang .family = NFPROTO_IPV4, 150218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang .size = XT_ALIGN(sizeof(struct ipt_ttl_info)), 151218647ebd721a259319b28f5719e89a4d0d1aaefShimeng (Simon) Wang .userspacesize = XT_ALIGN(sizeof(struct ipt_ttl_info)), 152ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .help = ttl_help, 153ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .parse = ttl_parse, 154ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .final_check = ttl_check, 155ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .print = ttl_print, 156ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .save = ttl_save, 157ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project .extra_opts = ttl_opts, 158ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project}; 159ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 160ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project 161ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Projectvoid _init(void) 162ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project{ 163ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project xtables_register_match(&ttl_mt_reg); 164ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project} 165ab4e2e90f63db6b1cd8bb2e453cac899ef43d42bThe Android Open Source Project