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      1 /*
      2  * Shared library add-on to iptables to add tos match support
      3  *
      4  * Copyright  CC Computer Consultants GmbH, 2007
      5  * Contact: Jan Engelhardt <jengelh (at) computergmbh.de>
      6  */
      7 #include <getopt.h>
      8 #include <netdb.h>
      9 #include <stdbool.h>
     10 #include <stdio.h>
     11 #include <stdlib.h>
     12 #include <string.h>
     13 
     14 #include <xtables.h>
     15 #include <linux/netfilter/xt_dscp.h>
     16 #include "tos_values.c"
     17 
     18 struct ipt_tos_info {
     19 	uint8_t tos;
     20 	uint8_t invert;
     21 };
     22 
     23 enum {
     24 	O_TOS = 1 << 0,
     25 };
     26 
     27 static const struct xt_option_entry tos_mt_opts_v0[] = {
     28 	{.name = "tos", .id = O_TOS, .type = XTTYPE_TOSMASK,
     29 	 .flags = XTOPT_INVERT | XTOPT_MAND, .max = 0xFF},
     30 	XTOPT_TABLEEND,
     31 };
     32 
     33 static const struct xt_option_entry tos_mt_opts[] = {
     34 	{.name = "tos", .id = O_TOS, .type = XTTYPE_TOSMASK,
     35 	 .flags = XTOPT_INVERT | XTOPT_MAND, .max = 0x3F},
     36 	XTOPT_TABLEEND,
     37 };
     38 
     39 static void tos_mt_help(void)
     40 {
     41 	const struct tos_symbol_info *symbol;
     42 
     43 	printf(
     44 "tos match options:\n"
     45 "[!] --tos value[/mask]    Match Type of Service/Priority field value\n"
     46 "[!] --tos symbol          Match TOS field (IPv4 only) by symbol\n"
     47 "                          Accepted symbolic names for value are:\n");
     48 
     49 	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
     50 		printf("                          (0x%02x) %2u %s\n",
     51 		       symbol->value, symbol->value, symbol->name);
     52 
     53 	printf("\n");
     54 }
     55 
     56 static void tos_mt_parse_v0(struct xt_option_call *cb)
     57 {
     58 	struct ipt_tos_info *info = cb->data;
     59 
     60 	xtables_option_parse(cb);
     61 	if (cb->val.tos_mask != 0xFF)
     62 		xtables_error(PARAMETER_PROBLEM, "tos: Your kernel is "
     63 		           "too old to support anything besides /0xFF "
     64 			   "as a mask.");
     65 	info->tos = cb->val.tos_value;
     66 	if (cb->invert)
     67 		info->invert = true;
     68 }
     69 
     70 static void tos_mt_parse(struct xt_option_call *cb)
     71 {
     72 	struct xt_tos_match_info *info = cb->data;
     73 
     74 	xtables_option_parse(cb);
     75 	info->tos_value = cb->val.tos_value;
     76 	info->tos_mask  = cb->val.tos_mask;
     77 	if (cb->invert)
     78 		info->invert = true;
     79 }
     80 
     81 static void tos_mt_print_v0(const void *ip, const struct xt_entry_match *match,
     82                             int numeric)
     83 {
     84 	const struct ipt_tos_info *info = (const void *)match->data;
     85 
     86 	printf(" tos match ");
     87 	if (info->invert)
     88 		printf("!");
     89 	if (numeric || !tos_try_print_symbolic("", info->tos, 0x3F))
     90 		printf("0x%02x", info->tos);
     91 }
     92 
     93 static void tos_mt_print(const void *ip, const struct xt_entry_match *match,
     94                          int numeric)
     95 {
     96 	const struct xt_tos_match_info *info = (const void *)match->data;
     97 
     98 	printf(" tos match");
     99 	if (info->invert)
    100 		printf("!");
    101 	if (numeric ||
    102 	    !tos_try_print_symbolic("", info->tos_value, info->tos_mask))
    103 		printf("0x%02x/0x%02x", info->tos_value, info->tos_mask);
    104 }
    105 
    106 static void tos_mt_save_v0(const void *ip, const struct xt_entry_match *match)
    107 {
    108 	const struct ipt_tos_info *info = (const void *)match->data;
    109 
    110 	if (info->invert)
    111 		printf(" !");
    112 	printf(" --tos 0x%02x", info->tos);
    113 }
    114 
    115 static void tos_mt_save(const void *ip, const struct xt_entry_match *match)
    116 {
    117 	const struct xt_tos_match_info *info = (const void *)match->data;
    118 
    119 	if (info->invert)
    120 		printf(" !");
    121 	printf(" --tos 0x%02x/0x%02x", info->tos_value, info->tos_mask);
    122 }
    123 
    124 static struct xtables_match tos_mt_reg[] = {
    125 	{
    126 		.version       = XTABLES_VERSION,
    127 		.name          = "tos",
    128 		.family        = NFPROTO_IPV4,
    129 		.revision      = 0,
    130 		.size          = XT_ALIGN(sizeof(struct ipt_tos_info)),
    131 		.userspacesize = XT_ALIGN(sizeof(struct ipt_tos_info)),
    132 		.help          = tos_mt_help,
    133 		.print         = tos_mt_print_v0,
    134 		.save          = tos_mt_save_v0,
    135 		.x6_parse      = tos_mt_parse_v0,
    136 		.x6_options    = tos_mt_opts_v0,
    137 	},
    138 	{
    139 		.version       = XTABLES_VERSION,
    140 		.name          = "tos",
    141 		.family        = NFPROTO_UNSPEC,
    142 		.revision      = 1,
    143 		.size          = XT_ALIGN(sizeof(struct xt_tos_match_info)),
    144 		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_match_info)),
    145 		.help          = tos_mt_help,
    146 		.print         = tos_mt_print,
    147 		.save          = tos_mt_save,
    148 		.x6_parse      = tos_mt_parse,
    149 		.x6_options    = tos_mt_opts,
    150 	},
    151 };
    152 
    153 void _init(void)
    154 {
    155 	xtables_register_matches(tos_mt_reg, ARRAY_SIZE(tos_mt_reg));
    156 }
    157