lib/tc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Traffic Control (TC) main library
   4  * Copyright (C) 2022  Shichu Yang
   5  */
   6
   7 #include "tc.h"
   8
   9 int tc_getrate(const char *str, uint64_t *rate)
  10 {
  11         char *endp;
  12         uint64_t raw = strtoull(str, &endp, 10);
  13
  14         if (endp == str)
  15                 return -1;
  16
  17         /* if the string only contains a number, it must be valid rate (bps) */
  18         bool valid = (*endp == '\0');
  19
  20         const char *p = endp;
  21         bool bytes = false, binary_base = false;
  22         int power = 0;
  23
  24         while (*p) {
  25                 if (strcmp(p, "Bps") == 0) {
  26                         bytes = true;
  27                         valid = true;
  28                         break;
  29                 } else if (strcmp(p, "bit") == 0) {
  30                         valid = true;
  31                         break;
  32                 }
  33                 switch (*p) {
  34                 case 'k':
  35                 case 'K':
  36                         power = 1;
  37                         break;
  38                 case 'm':
  39                 case 'M':
  40                         power = 2;
  41                         break;
  42                 case 'g':
  43                 case 'G':
  44                         power = 3;
  45                         break;
  46                 case 't':
  47                 case 'T':
  48                         power = 4;
  49                         break;
  50                 case 'i':
  51                 case 'I':
  52                         if (power != 0)
  53                                 binary_base = true;
  54                         else
  55                                 return -1;
  56                         break;
  57                 default:
  58                         return -1;
  59                 }
  60                 p++;
  61         }
  62
  63         if (!valid)
  64                 return -1;
  65
  66         for (int i = 0; i < power; i++)
  67                 raw *= binary_base ? 1024ULL : 1000ULL;
  68
  69         if (bytes)
  70                 *rate = raw;
  71         else
  72                 *rate = raw / 8ULL;
  73
  74         return 0;
  75 }