extensions/libxt_TOS.c

   1 /*
   2  * Shared library add-on to iptables to add TOS target support
   3  *
   4  * Copyright © CC Computer Consultants GmbH, 2007
   5  * Contact: Jan Engelhardt <jengelh@computergmbh.de>
   6  */
   7 #include <getopt.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 #include <xtables.h>
  13 #include <linux/netfilter/xt_DSCP.h>
  14 #include <linux/netfilter_ipv4/ipt_TOS.h>
  15 #include "tos_values.c"
  16
  17 enum {
  18         FLAG_TOS = 1 << 0,
  19 };
  20
  21 static const struct option tos_tg_opts_v0[] = {
  22         {.name = "set-tos", .has_arg = true, .val = '='},
  23         { .name = NULL }
  24 };
  25
  26 static const struct option tos_tg_opts[] = {
  27         {.name = "set-tos", .has_arg = true, .val = '='},
  28         {.name = "and-tos", .has_arg = true, .val = '&'},
  29         {.name = "or-tos",  .has_arg = true, .val = '|'},
  30         {.name = "xor-tos", .has_arg = true, .val = '^'},
  31         { .name = NULL }
  32 };
  33
  34 static void tos_tg_help_v0(void)
  35 {
  36         const struct tos_symbol_info *symbol;
  37
  38         printf(
  39 "TOS target options:\n"
  40 "  --set-tos value     Set Type of Service/Priority field to value\n"
  41 "  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
  42 "                      Accepted symbolic names for value are:\n");
  43
  44         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  45                 printf("                        (0x%02x) %2u %s\n",
  46                        symbol->value, symbol->value, symbol->name);
  47
  48         printf("\n");
  49 }
  50
  51 static void tos_tg_help(void)
  52 {
  53         const struct tos_symbol_info *symbol;
  54
  55         printf(
  56 "TOS target v%s options:\n"
  57 "  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
  58 "                          (Zero out bits in mask and XOR value into TOS)\n"
  59 "  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
  60 "                          (this zeroes the 4-bit Precedence part!)\n"
  61 "                          Accepted symbolic names for value are:\n",
  62 XTABLES_VERSION);
  63
  64         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  65                 printf("                            (0x%02x) %2u %s\n",
  66                        symbol->value, symbol->value, symbol->name);
  67
  68         printf(
  69 "\n"
  70 "  --and-tos bits          Binary AND the TOS value with bits\n"
  71 "  --or-tos  bits          Binary OR the TOS value with bits\n"
  72 "  --xor-tos bits          Binary XOR the TOS value with bits\n"
  73 );
  74 }
  75
  76 static int tos_tg_parse_v0(int c, char **argv, int invert, unsigned int *flags,
  77                            const void *entry, struct xt_entry_target **target)
  78 {
  79         struct ipt_tos_target_info *info = (void *)(*target)->data;
  80         struct tos_value_mask tvm;
  81
  82         switch (c) {
  83         case '=':
  84                 param_act(P_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
  85                 param_act(P_NO_INVERT, "TOS", "--set-tos", invert);
  86                 if (!tos_parse_symbolic(optarg, &tvm, 0xFF))
  87                         param_act(P_BAD_VALUE, "TOS", "--set-tos", optarg);
  88                 if (tvm.mask != 0xFF)
  89                         exit_error(PARAMETER_PROBLEM, "tos match: Your kernel "
  90                                    "is too old to support anything besides "
  91                                    "/0xFF as a mask.");
  92                 info->tos = tvm.value;
  93                 *flags |= FLAG_TOS;
  94                 return true;
  95         }
  96
  97         return false;
  98 }
  99
 100 static int tos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
 101                          const void *entry, struct xt_entry_target **target)
 102 {
 103         struct xt_tos_target_info *info = (void *)(*target)->data;
 104         struct tos_value_mask tvm;
 105         unsigned int bits;
 106
 107         switch (c) {
 108         case '=': /* --set-tos */
 109                 param_act(P_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
 110                 param_act(P_NO_INVERT, "TOS", "--set-tos", invert);
 111                 if (!tos_parse_symbolic(optarg, &tvm, 0x3F))
 112                         param_act(P_BAD_VALUE, "TOS", "--set-tos", optarg);
 113                 info->tos_value = tvm.value;
 114                 info->tos_mask  = tvm.mask;
 115                 break;
 116
 117         case '&': /* --and-tos */
 118                 param_act(P_ONLY_ONCE, "TOS", "--and-tos", *flags & FLAG_TOS);
 119                 param_act(P_NO_INVERT, "TOS", "--and-tos", invert);
 120                 if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
 121                         param_act(P_BAD_VALUE, "TOS", "--and-tos", optarg);
 122                 info->tos_value = 0;
 123                 info->tos_mask  = ~bits;
 124                 break;
 125
 126         case '|': /* --or-tos */
 127                 param_act(P_ONLY_ONCE, "TOS", "--or-tos", *flags & FLAG_TOS);
 128                 param_act(P_NO_INVERT, "TOS", "--or-tos", invert);
 129                 if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
 130                         param_act(P_BAD_VALUE, "TOS", "--or-tos", optarg);
 131                 info->tos_value = bits;
 132                 info->tos_mask  = bits;
 133                 break;
 134
 135         case '^': /* --xor-tos */
 136                 param_act(P_ONLY_ONCE, "TOS", "--xor-tos", *flags & FLAG_TOS);
 137                 param_act(P_NO_INVERT, "TOS", "--xor-tos", invert);
 138                 if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
 139                         param_act(P_BAD_VALUE, "TOS", "--xor-tos", optarg);
 140                 info->tos_value = bits;
 141                 info->tos_mask  = 0;
 142                 break;
 143
 144         default:
 145                 return false;
 146         }
 147
 148         *flags |= FLAG_TOS;
 149         return true;
 150 }
 151
 152 static void tos_tg_check(unsigned int flags)
 153 {
 154         if (flags == 0)
 155                 exit_error(PARAMETER_PROBLEM,
 156                            "TOS: The --set-tos parameter is required");
 157 }
 158
 159 static void tos_tg_print_v0(const void *ip,
 160                             const struct xt_entry_target *target, int numeric)
 161 {
 162         const struct ipt_tos_target_info *info = (const void *)target->data;
 163
 164         printf("TOS set ");
 165         if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
 166                 printf("0x%02x ", info->tos);
 167 }
 168
 169 static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
 170                          int numeric)
 171 {
 172         const struct xt_tos_target_info *info = (const void *)target->data;
 173
 174         if (numeric)
 175                 printf("TOS set 0x%02x/0x%02x ",
 176                        info->tos_value, info->tos_mask);
 177         else if (tos_try_print_symbolic("TOS set ",
 178             info->tos_value, info->tos_mask))
 179                 /* already printed by call */
 180                 return;
 181         else if (info->tos_value == 0)
 182                 printf("TOS and 0x%02x ",
 183                        (unsigned int)(u_int8_t)~info->tos_mask);
 184         else if (info->tos_value == info->tos_mask)
 185                 printf("TOS or 0x%02x ", info->tos_value);
 186         else if (info->tos_mask == 0)
 187                 printf("TOS xor 0x%02x ", info->tos_value);
 188         else
 189                 printf("TOS set 0x%02x/0x%02x ",
 190                        info->tos_value, info->tos_mask);
 191 }
 192
 193 static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
 194 {
 195         const struct ipt_tos_target_info *info = (const void *)target->data;
 196
 197         printf("--set-tos 0x%02x ", info->tos);
 198 }
 199
 200 static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
 201 {
 202         const struct xt_tos_target_info *info = (const void *)target->data;
 203
 204         printf("--set-tos 0x%02x/0x%02x ", info->tos_value, info->tos_mask);
 205 }
 206
 207 static struct xtables_target tos_tg_reg_v0 = {
 208         .version       = XTABLES_VERSION,
 209         .name          = "TOS",
 210         .revision      = 0,
 211         .family        = AF_INET,
 212         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 213         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 214         .help          = tos_tg_help_v0,
 215         .parse         = tos_tg_parse_v0,
 216         .final_check   = tos_tg_check,
 217         .print         = tos_tg_print_v0,
 218         .save          = tos_tg_save_v0,
 219         .extra_opts    = tos_tg_opts_v0,
 220 };
 221
 222 static struct xtables_target tos_tg_reg = {
 223         .version       = XTABLES_VERSION,
 224         .name          = "TOS",
 225         .revision      = 1,
 226         .family        = AF_INET,
 227         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 228         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 229         .help          = tos_tg_help,
 230         .parse         = tos_tg_parse,
 231         .final_check   = tos_tg_check,
 232         .print         = tos_tg_print,
 233         .save          = tos_tg_save,
 234         .extra_opts    = tos_tg_opts,
 235 };
 236
 237 static struct xtables_target tos_tg6_reg = {
 238         .version       = XTABLES_VERSION,
 239         .name          = "TOS",
 240         .family        = AF_INET6,
 241         .revision      = 1,
 242         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 243         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 244         .help          = tos_tg_help,
 245         .parse         = tos_tg_parse,
 246         .final_check   = tos_tg_check,
 247         .print         = tos_tg_print,
 248         .save          = tos_tg_save,
 249         .extra_opts    = tos_tg_opts,
 250 };
 251
 252 void _init(void)
 253 {
 254         xtables_register_target(&tos_tg_reg_v0);
 255         xtables_register_target(&tos_tg_reg);
 256         xtables_register_target(&tos_tg6_reg);
 257 }