lib/tc.c

   1 /*
   2  * Traffic Control (TC) main library
   3  * Copyright (C) 2022  Shichu Yang
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; either version 2 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; see the file COPYING; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include "tc.h"
  21
  22 int tc_getrate(const char *str, uint64_t *rate)
  23 {
  24         char *endp;
  25         uint64_t raw = strtoull(str, &endp, 10);
  26
  27         if (endp == str)
  28                 return -1;
  29
  30         /* if the string only contains a number, it must be valid rate (bps) */
  31         bool valid = (*endp == '\0');
  32
  33         const char *p = endp;
  34         bool bytes = false, binary_base = false;
  35         int power = 0;
  36
  37         while (*p) {
  38                 if (strcmp(p, "Bps") == 0) {
  39                         bytes = true;
  40                         valid = true;
  41                         break;
  42                 } else if (strcmp(p, "bit") == 0) {
  43                         valid = true;
  44                         break;
  45                 }
  46                 switch (*p) {
  47                 case 'k':
  48                 case 'K':
  49                         power = 1;
  50                         break;
  51                 case 'm':
  52                 case 'M':
  53                         power = 2;
  54                         break;
  55                 case 'g':
  56                 case 'G':
  57                         power = 3;
  58                         break;
  59                 case 't':
  60                 case 'T':
  61                         power = 4;
  62                         break;
  63                 case 'i':
  64                 case 'I':
  65                         if (power != 0)
  66                                 binary_base = true;
  67                         else
  68                                 return -1;
  69                         break;
  70                 default:
  71                         return -1;
  72                 }
  73                 p++;
  74         }
  75
  76         if (!valid)
  77                 return -1;
  78
  79         for (int i = 0; i < power; i++)
  80                 raw *= binary_base ? 1024ULL : 1000ULL;
  81
  82         if (bytes)
  83                 *rate = raw;
  84         else
  85                 *rate = raw / 8ULL;
  86
  87         return 0;
  88 }