compat/xstrto.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_XSTRTO_C_
  10 #define SQUID_XSTRTO_C_
  11
  12 /*
  13  *  Shamelessly duplicated from the netfilter iptables sources
  14  *  for use by the Squid Project under GNU Public License.
  15  *
  16  * Reason for use as explained by Luciano Coelho:
  17  * "I found that there is a bug in strtoul (and strtoull for
  18  * that matter) that causes the long to overflow if there are valid digits
  19  * after the maximum possible digits for the base.  For example if you try
  20  * to strtoul 0xfffffffff (with 9 f's) the strtoul will overflow and come
  21  * up with a bogus result.  I can't easily truncate the string to avoid
  22  * this problem, because with decimal or octal, the same valid value would
  23  * take more spaces.  I could do some magic here, checking whether it's a
  24  * hex, dec or oct and truncate appropriately, but that would be very ugly.
  25  * So the simplest way I came up with was to use strtoull and return
  26  * -EINVAL if the value exceeds 32 bits."
  27  *
  28  * Update/Maintenance History:
  29  *
  30  *    12-Sep-2010 : Copied from iptables xtables.c
  31  *          - xtables_strtoui renamed to xstrtoui
  32  *          - xtables_strtoul renamed to xstrtoul
  33  *
  34  *  Original License and code follows.
  35  */
  36
  37 #include "squid.h"
  38 #include "compat/xstrto.h"
  39
  40 /*
  41  * (C) 2000-2006 by the netfilter coreteam <coreteam@netfilter.org>:
  42  *
  43  *      This program is free software; you can redistribute it and/or modify
  44  *      it under the terms of the GNU General Public License as published by
  45  *      the Free Software Foundation; either version 2 of the License, or
  46  *      (at your option) any later version.
  47  *
  48  *      This program is distributed in the hope that it will be useful,
  49  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  50  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  51  *      GNU General Public License for more details.
  52  *
  53  *      You should have received a copy of the GNU General Public License
  54  *      along with this program; if not, write to the Free Software
  55  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  56  */
  57
  58 #include <cerrno>
  59
  60 bool
  61 xstrtoul(const char *s, char **end, unsigned long *value,
  62          unsigned long min, unsigned long max)
  63 {
  64     char *my_end = NULL;
  65
  66     errno = 0;
  67     unsigned long v = strtoul(s, &my_end, 0);
  68
  69     if (my_end == s)
  70         return false;
  71     if (end != NULL)
  72         *end = my_end;
  73
  74     if (errno != ERANGE && min <= v && (max == 0 || v <= max)) {
  75         if (value != NULL)
  76             *value = v;
  77         if (end == NULL)
  78             return *my_end == '\0';
  79         return true;
  80     }
  81
  82     return false;
  83 }
  84
  85 bool
  86 xstrtoui(const char *s, char **end, unsigned int *value,
  87          unsigned int min, unsigned int max)
  88 {
  89     unsigned long v = 0;
  90     bool ret = xstrtoul(s, end, &v, min, max);
  91     if (value != NULL) {
  92         *value = v;
  93
  94         if (v != static_cast<unsigned long>(*value)) {
  95             return false;
  96         }
  97     }
  98
  99     return ret;
 100 }
 101
 102 #endif /* SQUID_XSTRTO_C_ */
 103