aboutsummaryrefslogtreecommitdiff
path: root/lib/strtoofft.c
blob: 546a3ff75d6207efa11ebd48a7d0d072a501e353 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include <errno.h>
#include "curl_setup.h"

#include "strtoofft.h"

/*
 * NOTE:
 *
 * In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
 * could use in case strtoll() doesn't exist...  See
 * https://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
 */

#if (SIZEOF_CURL_OFF_T > SIZEOF_LONG)
#  ifdef HAVE_STRTOLL
#    define strtooff strtoll
#  else
#    if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_INTEGRAL_MAX_BITS >= 64)
#      if defined(_SAL_VERSION)
         _Check_return_ _CRTIMP __int64 __cdecl _strtoi64(
             _In_z_ const char *_String,
             _Out_opt_ _Deref_post_z_ char **_EndPtr, _In_ int _Radix);
#      else
         _CRTIMP __int64 __cdecl _strtoi64(const char *_String,
                                           char **_EndPtr, int _Radix);
#      endif
#      define strtooff _strtoi64
#    else
#      define PRIVATE_STRTOOFF 1
#    endif
#  endif
#else
#  define strtooff strtol
#endif

#ifdef PRIVATE_STRTOOFF

/* Range tests can be used for alphanum decoding if characters are consecutive,
   like in ASCII. Else an array is scanned. Determine this condition now. */

#if('9' - '0') != 9 || ('Z' - 'A') != 25 || ('z' - 'a') != 25

#define NO_RANGE_TEST

static const char valchars[] =
            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
#endif

static int get_char(char c, int base);

/**
 * Custom version of the strtooff function.  This extracts a curl_off_t
 * value from the given input string and returns it.
 */
static curl_off_t strtooff(const char *nptr, char **endptr, int base)
{
  char *end;
  int is_negative = 0;
  int overflow;
  int i;
  curl_off_t value = 0;
  curl_off_t newval;

  /* Skip leading whitespace. */
  end = (char *)nptr;
  while(ISSPACE(end[0])) {
    end++;
  }

  /* Handle the sign, if any. */
  if(end[0] == '-') {
    is_negative = 1;
    end++;
  }
  else if(end[0] == '+') {
    end++;
  }
  else if(end[0] == '\0') {
    /* We had nothing but perhaps some whitespace -- there was no number. */
    if(endptr) {
      *endptr = end;
    }
    return 0;
  }

  /* Handle special beginnings, if present and allowed. */
  if(end[0] == '0' && end[1] == 'x') {
    if(base == 16 || base == 0) {
      end += 2;
      base = 16;
    }
  }
  else if(end[0] == '0') {
    if(base == 8 || base == 0) {
      end++;
      base = 8;
    }
  }

  /* Matching strtol, if the base is 0 and it doesn't look like
   * the number is octal or hex, we assume it's base 10.
   */
  if(base == 0) {
    base = 10;
  }

  /* Loop handling digits. */
  value = 0;
  overflow = 0;
  for(i = get_char(end[0], base);
      i != -1;
      end++, i = get_char(end[0], base)) {
    newval = base * value + i;
    if(newval < value) {
      /* We've overflowed. */
      overflow = 1;
      break;
    }
    else
      value = newval;
  }

  if(!overflow) {
    if(is_negative) {
      /* Fix the sign. */
      value *= -1;
    }
  }
  else {
    if(is_negative)
      value = CURL_OFF_T_MIN;
    else
      value = CURL_OFF_T_MAX;

    errno = ERANGE;
  }

  if(endptr)
    *endptr = end;

  return value;
}

/**
 * Returns the value of c in the given base, or -1 if c cannot
 * be interpreted properly in that base (i.e., is out of range,
 * is a null, etc.).
 *
 * @param c     the character to interpret according to base
 * @param base  the base in which to interpret c
 *
 * @return  the value of c in base, or -1 if c isn't in range
 */
static int get_char(char c, int base)
{
#ifndef NO_RANGE_TEST
  int value = -1;
  if(c <= '9' && c >= '0') {
    value = c - '0';
  }
  else if(c <= 'Z' && c >= 'A') {
    value = c - 'A' + 10;
  }
  else if(c <= 'z' && c >= 'a') {
    value = c - 'a' + 10;
  }
#else
  const char *cp;
  int value;

  cp = memchr(valchars, c, 10 + 26 + 26);

  if(!cp)
    return -1;

  value = cp - valchars;

  if(value >= 10 + 26)
    value -= 26;                /* Lowercase. */
#endif

  if(value >= base) {
    value = -1;
  }

  return value;
}
#endif  /* Only present if we need strtoll, but don't have it. */

/*
 * Parse a *positive* up to 64 bit number written in ascii.
 */
CURLofft curlx_strtoofft(const char *str, char **endp, int base,
                         curl_off_t *num)
{
  char *end;
  curl_off_t number;
  errno = 0;
  *num = 0; /* clear by default */

  while(*str && ISSPACE(*str))
    str++;
  if('-' == *str) {
    if(endp)
      *endp = (char *)str; /* didn't actually move */
    return CURL_OFFT_INVAL; /* nothing parsed */
  }
  number = strtooff(str, &end, base);
  if(endp)
    *endp = end;
  if(errno == ERANGE)
    /* overflow/underflow */
    return CURL_OFFT_FLOW;
  else if(str == end)
    /* nothing parsed */
    return CURL_OFFT_INVAL;

  *num = number;
  return CURL_OFFT_OK;
}