compat/strtoll.c

   1 /*
   2  * Copyright (C) 1996-2021 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 /*-
  10  * Copyright (c) 1990 The Regents of the University of California.
  11  * All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *  This product includes software developed by the University of
  24  *  California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  */
  41
  42 /* modified for long long <mgd@swarm.org> 1999-08-12 */
  43
  44 #include "squid.h"
  45 #include "compat/strtoll.h"
  46
  47 #if HAVE_CTYPE_H
  48 #include <ctype.h>
  49 #endif
  50 #if HAVE_ERRNO_H
  51 #include <errno.h>
  52 #endif
  53
  54 #ifndef INT64_MIN
  55 /* Native 64 bit system without strtoll() */
  56 #if defined(LONG_MIN) && (SIZEOF_LONG == 8)
  57 #define INT64_MIN LONG_MIN
  58 #else
  59 /* 32 bit system */
  60 #define INT64_MIN       (-9223372036854775807LL-1LL)
  61 #endif
  62 #endif
  63
  64 #ifndef INT64_MAX
  65 /* Native 64 bit system without strtoll() */
  66 #if defined(LONG_MAX) && (SIZEOF_LONG == 8)
  67 #define INT64_MAX LONG_MAX
  68 #else
  69 /* 32 bit system */
  70 #define INT64_MAX       9223372036854775807LL
  71 #endif
  72 #endif
  73
  74 /*
  75  * Convert a string to a int64 integer.
  76  *
  77  * Ignores `locale' stuff.  Assumes that the upper and lower case
  78  * alphabets and digits are each contiguous.
  79  */
  80 int64_t
  81 strtoll (const char *nptr, char **endptr, int base)
  82 {
  83     register const char *s = nptr;
  84     register uint64_t acc;
  85     register int c;
  86     register uint64_t cutoff;
  87     register int neg = 0, any, cutlim;
  88
  89     /*
  90      * Skip white space and pick up leading +/- sign if any.
  91      * If base is 0, allow 0x for hex and 0 for octal, else
  92      * assume decimal; if base is already 16, allow 0x.
  93      */
  94     do {
  95         c = *s++;
  96     } while (xisspace(c));
  97     if (c == '-') {
  98         neg = 1;
  99         c = *s++;
 100     } else if (c == '+')
 101         c = *s++;
 102     if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
 103         c = s[1];
 104         s += 2;
 105         base = 16;
 106     }
 107     if (base == 0)
 108         base = c == '0' ? 8 : 10;
 109
 110     /*
 111      * Compute the cutoff value between legal numbers and illegal
 112      * numbers.  That is the largest legal value, divided by the
 113      * base.  An input number that is greater than this value, if
 114      * followed by a legal input character, is too big.  One that
 115      * is equal to this value may be valid or not; the limit
 116      * between valid and invalid numbers is then based on the last
 117      * digit.  For instance, if the range for longs is
 118      * [-2147483648..2147483647] and the input base is 10,
 119      * cutoff will be set to 214748364 and cutlim to either
 120      * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 121      * a value > 214748364, or equal but the next digit is > 7 (or 8),
 122      * the number is too big, and we will return a range error.
 123      *
 124      * Set any if any `digits' consumed; make it negative to indicate
 125      * overflow.
 126      */
 127     cutoff = neg ? -(uint64_t) INT64_MIN : INT64_MAX;
 128     cutlim = cutoff % (uint64_t) base;
 129     cutoff /= (uint64_t) base;
 130     for (acc = 0, any = 0;; c = *s++) {
 131         if (xisdigit(c))
 132             c -= '0';
 133         else if (xisalpha(c))
 134             c -= xisupper(c) ? 'A' - 10 : 'a' - 10;
 135         else
 136             break;
 137         if (c >= base)
 138             break;
 139         if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 140             any = -1;
 141         else {
 142             any = 1;
 143             acc *= base;
 144             acc += c;
 145         }
 146     }
 147     if (any < 0) {
 148         acc = neg ? INT64_MIN : INT64_MAX;
 149         errno = ERANGE;
 150     } else if (neg)
 151         acc = -acc;
 152     if (endptr != 0)
 153         *endptr = (char *) (any ? s - 1 : nptr);
 154     return acc;
 155 }
 156