extensions/tos_values.c

   1 #include <stdbool.h>
   2 #include <stdint.h>
   3 #include <stdio.h>
   4 #include <linux/ip.h>
   5
   6 struct tos_value_mask {
   7         uint8_t value, mask;
   8 };
   9
  10 static const struct tos_symbol_info {
  11         unsigned char value;
  12         const char *name;
  13 } tos_symbol_names[] = {
  14         {IPTOS_LOWDELAY,    "Minimize-Delay"},
  15         {IPTOS_THROUGHPUT,  "Maximize-Throughput"},
  16         {IPTOS_RELIABILITY, "Maximize-Reliability"},
  17         {IPTOS_MINCOST,     "Minimize-Cost"},
  18         {IPTOS_NORMALSVC,   "Normal-Service"},
  19         { .name = NULL }
  20 };
  21
  22 /*
  23  * tos_parse_numeric - parse sth. like "15/255"
  24  *
  25  * @s:          input string
  26  * @info:       accompanying structure
  27  * @bits:       number of bits that are allowed
  28  *              (8 for IPv4 TOS field, 4 for IPv6 Priority Field)
  29  */
  30 static bool tos_parse_numeric(const char *str, struct tos_value_mask *tvm,
  31                               unsigned int bits)
  32 {
  33         const unsigned int max = (1 << bits) - 1;
  34         unsigned int value;
  35         char *end;
  36
  37         xtables_strtoui(str, &end, &value, 0, max);
  38         tvm->value = value;
  39         tvm->mask  = max;
  40
  41         if (*end == '/') {
  42                 const char *p = end + 1;
  43
  44                 if (!xtables_strtoui(p, &end, &value, 0, max))
  45                         xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"",
  46                                    str);
  47                 tvm->mask = value;
  48         }
  49
  50         if (*end != '\0')
  51                 xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"", str);
  52         return true;
  53 }
  54
  55 static bool tos_parse_symbolic(const char *str, struct tos_value_mask *tvm,
  56     unsigned int def_mask)
  57 {
  58         const unsigned int max = UINT8_MAX;
  59         const struct tos_symbol_info *symbol;
  60         char *tmp;
  61
  62         if (xtables_strtoui(str, &tmp, NULL, 0, max))
  63                 return tos_parse_numeric(str, tvm, max);
  64
  65         /* Do not consider ECN bits */
  66         tvm->mask = def_mask;
  67         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  68                 if (strcasecmp(str, symbol->name) == 0) {
  69                         tvm->value = symbol->value;
  70                         return true;
  71                 }
  72
  73         xtables_error(PARAMETER_PROBLEM, "Symbolic name \"%s\" is unknown", str);
  74         return false;
  75 }
  76
  77 static bool tos_try_print_symbolic(const char *prefix,
  78     u_int8_t value, u_int8_t mask)
  79 {
  80         const struct tos_symbol_info *symbol;
  81
  82         if (mask != 0x3F)
  83                 return false;
  84
  85         for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
  86                 if (value == symbol->value) {
  87                         printf("%s%s ", prefix, symbol->name);
  88                         return true;
  89                 }
  90
  91         return false;
  92 }