compat/xstrto.cc

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