extensions/libxt_tos.c

   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@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 }