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 #include <netinet/in.h>
  12
  13 #include <xtables.h>
  14 #include <linux/netfilter/xt_DSCP.h>
  15 #include <linux/netfilter_ipv4/ipt_TOS.h>
  16 #include "tos_values.c"
  17
  18 enum {
  19         FLAG_TOS = 1 << 0,
  20 };
  21
  22 static const struct option tos_tg_opts_v0[] = {
  23         {.name = "set-tos", .has_arg = true, .val = '='},
  24         { .name = NULL }
  25 };
  26
  27 static const struct option tos_tg_opts[] = {
  28         {.name = "set-tos", .has_arg = true, .val = '='},
  29         {.name = "and-tos", .has_arg = true, .val = '&'},
  30         {.name = "or-tos",  .has_arg = true, .val = '|'},
  31         {.name = "xor-tos", .has_arg = true, .val = '^'},
  32         { .name = NULL }
  33 };
  34
  35 static void tos_tg_help_v0(void)
  36 {
  37         const struct tos_symbol_info *symbol;
  38
  39         printf(
  40 "TOS target options:\n"
  41 "  --set-tos value     Set Type of Service/Priority field to value\n"
  42 "  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
  43 "                      Accepted symbolic names for value are:\n");
  44
  45         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  46                 printf("                        (0x%02x) %2u %s\n",
  47                        symbol->value, symbol->value, symbol->name);
  48
  49         printf("\n");
  50 }
  51
  52 static void tos_tg_help(void)
  53 {
  54         const struct tos_symbol_info *symbol;
  55
  56         printf(
  57 "TOS target v%s options:\n"
  58 "  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
  59 "                          (Zero out bits in mask and XOR value into TOS)\n"
  60 "  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
  61 "                          (this zeroes the 4-bit Precedence part!)\n"
  62 "                          Accepted symbolic names for value are:\n",
  63 XTABLES_VERSION);
  64
  65         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  66                 printf("                            (0x%02x) %2u %s\n",
  67                        symbol->value, symbol->value, symbol->name);
  68
  69         printf(
  70 "\n"
  71 "  --and-tos bits          Binary AND the TOS value with bits\n"
  72 "  --or-tos  bits          Binary OR the TOS value with bits\n"
  73 "  --xor-tos bits          Binary XOR the TOS value with bits\n"
  74 );
  75 }
  76
  77 static int tos_tg_parse_v0(int c, char **argv, int invert, unsigned int *flags,
  78                            const void *entry, struct xt_entry_target **target)
  79 {
  80         struct ipt_tos_target_info *info = (void *)(*target)->data;
  81         struct tos_value_mask tvm;
  82
  83         switch (c) {
  84         case '=':
  85                 xtables_param_act(XTF_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
  86                 xtables_param_act(XTF_NO_INVERT, "TOS", "--set-tos", invert);
  87                 if (!tos_parse_symbolic(optarg, &tvm, 0xFF))
  88                         xtables_param_act(XTF_BAD_VALUE, "TOS", "--set-tos", optarg);
  89                 if (tvm.mask != 0xFF)
  90                         xtables_error(PARAMETER_PROBLEM, "tos match: Your kernel "
  91                                    "is too old to support anything besides "
  92                                    "/0xFF as a mask.");
  93                 info->tos = tvm.value;
  94                 *flags |= FLAG_TOS;
  95                 return true;
  96         }
  97
  98         return false;
  99 }
 100
 101 static int tos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
 102                          const void *entry, struct xt_entry_target **target)
 103 {
 104         struct xt_tos_target_info *info = (void *)(*target)->data;
 105         struct tos_value_mask tvm;
 106         unsigned int bits;
 107
 108         switch (c) {
 109         case '=': /* --set-tos */
 110                 xtables_param_act(XTF_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
 111                 xtables_param_act(XTF_NO_INVERT, "TOS", "--set-tos", invert);
 112                 if (!tos_parse_symbolic(optarg, &tvm, 0x3F))
 113                         xtables_param_act(XTF_BAD_VALUE, "TOS", "--set-tos", optarg);
 114                 info->tos_value = tvm.value;
 115                 info->tos_mask  = tvm.mask;
 116                 break;
 117
 118         case '&': /* --and-tos */
 119                 xtables_param_act(XTF_ONLY_ONCE, "TOS", "--and-tos", *flags & FLAG_TOS);
 120                 xtables_param_act(XTF_NO_INVERT, "TOS", "--and-tos", invert);
 121                 if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
 122                         xtables_param_act(XTF_BAD_VALUE, "TOS", "--and-tos", optarg);
 123                 info->tos_value = 0;
 124                 info->tos_mask  = ~bits;
 125                 break;
 126
 127         case '|': /* --or-tos */
 128                 xtables_param_act(XTF_ONLY_ONCE, "TOS", "--or-tos", *flags & FLAG_TOS);
 129                 xtables_param_act(XTF_NO_INVERT, "TOS", "--or-tos", invert);
 130                 if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
 131                         xtables_param_act(XTF_BAD_VALUE, "TOS", "--or-tos", optarg);
 132                 info->tos_value = bits;
 133                 info->tos_mask  = bits;
 134                 break;
 135
 136         case '^': /* --xor-tos */
 137                 xtables_param_act(XTF_ONLY_ONCE, "TOS", "--xor-tos", *flags & FLAG_TOS);
 138                 xtables_param_act(XTF_NO_INVERT, "TOS", "--xor-tos", invert);
 139                 if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
 140                         xtables_param_act(XTF_BAD_VALUE, "TOS", "--xor-tos", optarg);
 141                 info->tos_value = bits;
 142                 info->tos_mask  = 0;
 143                 break;
 144
 145         default:
 146                 return false;
 147         }
 148
 149         *flags |= FLAG_TOS;
 150         return true;
 151 }
 152
 153 static void tos_tg_check(unsigned int flags)
 154 {
 155         if (flags == 0)
 156                 xtables_error(PARAMETER_PROBLEM,
 157                            "TOS: The --set-tos parameter is required");
 158 }
 159
 160 static void tos_tg_print_v0(const void *ip,
 161                             const struct xt_entry_target *target, int numeric)
 162 {
 163         const struct ipt_tos_target_info *info = (const void *)target->data;
 164
 165         printf("TOS set ");
 166         if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
 167                 printf("0x%02x ", info->tos);
 168 }
 169
 170 static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
 171                          int numeric)
 172 {
 173         const struct xt_tos_target_info *info = (const void *)target->data;
 174
 175         if (numeric)
 176                 printf("TOS set 0x%02x/0x%02x ",
 177                        info->tos_value, info->tos_mask);
 178         else if (tos_try_print_symbolic("TOS set ",
 179             info->tos_value, info->tos_mask))
 180                 /* already printed by call */
 181                 return;
 182         else if (info->tos_value == 0)
 183                 printf("TOS and 0x%02x ",
 184                        (unsigned int)(u_int8_t)~info->tos_mask);
 185         else if (info->tos_value == info->tos_mask)
 186                 printf("TOS or 0x%02x ", info->tos_value);
 187         else if (info->tos_mask == 0)
 188                 printf("TOS xor 0x%02x ", info->tos_value);
 189         else
 190                 printf("TOS set 0x%02x/0x%02x ",
 191                        info->tos_value, info->tos_mask);
 192 }
 193
 194 static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
 195 {
 196         const struct ipt_tos_target_info *info = (const void *)target->data;
 197
 198         printf("--set-tos 0x%02x ", info->tos);
 199 }
 200
 201 static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
 202 {
 203         const struct xt_tos_target_info *info = (const void *)target->data;
 204
 205         printf("--set-tos 0x%02x/0x%02x ", info->tos_value, info->tos_mask);
 206 }
 207
 208 static struct xtables_target tos_tg_reg_v0 = {
 209         .version       = XTABLES_VERSION,
 210         .name          = "TOS",
 211         .revision      = 0,
 212         .family        = NFPROTO_IPV4,
 213         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 214         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 215         .help          = tos_tg_help_v0,
 216         .parse         = tos_tg_parse_v0,
 217         .final_check   = tos_tg_check,
 218         .print         = tos_tg_print_v0,
 219         .save          = tos_tg_save_v0,
 220         .extra_opts    = tos_tg_opts_v0,
 221 };
 222
 223 static struct xtables_target tos_tg_reg = {
 224         .version       = XTABLES_VERSION,
 225         .name          = "TOS",
 226         .revision      = 1,
 227         .family        = NFPROTO_IPV4,
 228         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 229         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 230         .help          = tos_tg_help,
 231         .parse         = tos_tg_parse,
 232         .final_check   = tos_tg_check,
 233         .print         = tos_tg_print,
 234         .save          = tos_tg_save,
 235         .extra_opts    = tos_tg_opts,
 236 };
 237
 238 static struct xtables_target tos_tg6_reg = {
 239         .version       = XTABLES_VERSION,
 240         .name          = "TOS",
 241         .family        = NFPROTO_IPV6,
 242         .revision      = 1,
 243         .size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 244         .userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
 245         .help          = tos_tg_help,
 246         .parse         = tos_tg_parse,
 247         .final_check   = tos_tg_check,
 248         .print         = tos_tg_print,
 249         .save          = tos_tg_save,
 250         .extra_opts    = tos_tg_opts,
 251 };
 252
 253 void _init(void)
 254 {
 255         xtables_register_target(&tos_tg_reg_v0);
 256         xtables_register_target(&tos_tg_reg);
 257         xtables_register_target(&tos_tg6_reg);
 258 }