release/src/router/iptables/extensions/libipt_tos.c

   1 /* Shared library add-on to iptables to add TOS matching support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <getopt.h>
   7
   8 #include <iptables.h>
   9 #include <linux/netfilter_ipv4/ipt_tos.h>
  10
  11 /* TOS names and values. */
  12 static
  13 struct TOS_value
  14 {
  15         unsigned char TOS;
  16         const char *name;
  17 } TOS_values[] = {
  18         { IPTOS_LOWDELAY,    "Minimize-Delay" },
  19         { IPTOS_THROUGHPUT,  "Maximize-Throughput" },
  20         { IPTOS_RELIABILITY, "Maximize-Reliability" },
  21         { IPTOS_MINCOST,     "Minimize-Cost" },
  22         { IPTOS_NORMALSVC,   "Normal-Service" },
  23 };
  24
  25 /* Function which prints out usage message. */
  26 static void
  27 help(void)
  28 {
  29         unsigned int i;
  30
  31         printf(
  32 "TOS match v%s options:\n"
  33 "[!] --tos value                 Match Type of Service field from one of the\n"
  34 "                                following numeric or descriptive values:\n",
  35 IPTABLES_VERSION);
  36
  37         for (i = 0; i < sizeof(TOS_values)/sizeof(struct TOS_value);i++)
  38                 printf("                                     %s %u (0x%02x)\n",
  39                        TOS_values[i].name,
  40                        TOS_values[i].TOS,
  41                        TOS_values[i].TOS);
  42         fputc('\n', stdout);
  43 }
  44
  45 static struct option opts[] = {
  46         { "tos", 1, 0, '1' },
  47         {0}
  48 };
  49
  50 static void
  51 parse_tos(const char *s, struct ipt_tos_info *info)
  52 {
  53         unsigned int i;
  54         unsigned int tos;
  55
  56         if (string_to_number(s, 0, 255, &tos) != -1) {
  57                 if (tos == IPTOS_LOWDELAY
  58                     || tos == IPTOS_THROUGHPUT
  59                     || tos == IPTOS_RELIABILITY
  60                     || tos == IPTOS_MINCOST
  61                     || tos == IPTOS_NORMALSVC) {
  62                         info->tos = (u_int8_t )tos;
  63                         return;
  64                 }
  65         } else {
  66                 for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
  67                         if (strcasecmp(s,TOS_values[i].name) == 0) {
  68                                 info->tos = TOS_values[i].TOS;
  69                                 return;
  70                         }
  71         }
  72         exit_error(PARAMETER_PROBLEM, "Bad TOS value `%s'", s);
  73 }
  74
  75 /* Function which parses command options; returns true if it
  76    ate an option */
  77 static int
  78 parse(int c, char **argv, int invert, unsigned int *flags,
  79       const struct ipt_entry *entry,
  80       unsigned int *nfcache,
  81       struct ipt_entry_match **match)
  82 {
  83         struct ipt_tos_info *tosinfo = (struct ipt_tos_info *)(*match)->data;
  84
  85         switch (c) {
  86         case '1':
  87                 /* Ensure that `--tos' haven't been used yet. */
  88                 if (*flags == 1)
  89                         exit_error(PARAMETER_PROBLEM,
  90                                         "tos match: only use --tos once!");
  91
  92                 check_inverse(optarg, &invert, &optind, 0);
  93                 parse_tos(argv[optind-1], tosinfo);
  94                 if (invert)
  95                         tosinfo->invert = 1;
  96                 *flags = 1;
  97                 break;
  98
  99         default:
 100                 return 0;
 101         }
 102         return 1;
 103 }
 104
 105 static void
 106 print_tos(u_int8_t tos, int numeric)
 107 {
 108         unsigned int i;
 109
 110         if (!numeric) {
 111                 for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
 112                         if (TOS_values[i].TOS == tos) {
 113                                 printf("%s ", TOS_values[i].name);
 114                                 return;
 115                         }
 116         }
 117         printf("0x%02x ", tos);
 118 }
 119
 120 /* Final check; must have specified --tos. */
 121 static void
 122 final_check(unsigned int flags)
 123 {
 124         if (!flags)
 125                 exit_error(PARAMETER_PROBLEM,
 126                            "TOS match: You must specify `--tos'");
 127 }
 128
 129 /* Prints out the matchinfo. */
 130 static void
 131 print(const struct ipt_ip *ip,
 132       const struct ipt_entry_match *match,
 133       int numeric)
 134 {
 135         const struct ipt_tos_info *info = (const struct ipt_tos_info *)match->data;
 136
 137         printf("TOS match ");
 138         if (info->invert)
 139                 printf("!");
 140         print_tos(info->tos, numeric);
 141 }
 142
 143 /* Saves the union ipt_matchinfo in parsable form to stdout. */
 144 static void
 145 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 146 {
 147         const struct ipt_tos_info *info = (const struct ipt_tos_info *)match->data;
 148
 149         if (info->invert)
 150                 printf("! ");
 151         printf("--tos ");
 152         print_tos(info->tos, 0);
 153 }
 154
 155 static struct iptables_match tos = {
 156         .next           = NULL,
 157         .name           = "tos",
 158         .version        = IPTABLES_VERSION,
 159         .size           = IPT_ALIGN(sizeof(struct ipt_tos_info)),
 160         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_tos_info)),
 161         .help           = &help,
 162         .parse          = &parse,
 163         .final_check    = &final_check,
 164         .print          = &print,
 165         .save           = &save,
 166         .extra_opts     = opts
 167 };
 168
 169 void _init(void)
 170 {
 171         register_match(&tos);
 172 }