1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include <errno.h>
24#include "curl_setup.h"
25
26#include "strtoofft.h"
27
28/*
29 * NOTE:
30 *
31 * In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
32 * could use in case strtoll() doesn't exist... See
33 * https://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
34 */
35
36#if (SIZEOF_CURL_OFF_T > SIZEOF_LONG)
37# ifdef HAVE_STRTOLL
38# define strtooff strtoll
39# else
40# if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_INTEGRAL_MAX_BITS >= 64)
41# if defined(_SAL_VERSION)
42 _Check_return_ _CRTIMP __int64 __cdecl _strtoi64(
43 _In_z_ const char *_String,
44 _Out_opt_ _Deref_post_z_ char **_EndPtr, _In_ int _Radix);
45# else
46 _CRTIMP __int64 __cdecl _strtoi64(const char *_String,
47 char **_EndPtr, int _Radix);
48# endif
49# define strtooff _strtoi64
50# else
51# define PRIVATE_STRTOOFF 1
52# endif
53# endif
54#else
55# define strtooff strtol
56#endif
57
58#ifdef PRIVATE_STRTOOFF
59
60/* Range tests can be used for alphanum decoding if characters are consecutive,
61 like in ASCII. Else an array is scanned. Determine this condition now. */
62
63#if('9' - '0') != 9 || ('Z' - 'A') != 25 || ('z' - 'a') != 25
64
65#define NO_RANGE_TEST
66
67static const char valchars[] =
68 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
69#endif
70
71static int get_char(char c, int base);
72
73/**
74 * Custom version of the strtooff function. This extracts a curl_off_t
75 * value from the given input string and returns it.
76 */
77static curl_off_t strtooff(const char *nptr, char **endptr, int base)
78{
79 char *end;
80 int is_negative = 0;
81 int overflow;
82 int i;
83 curl_off_t value = 0;
84 curl_off_t newval;
85
86 /* Skip leading whitespace. */
87 end = (char *)nptr;
88 while(ISSPACE(end[0])) {
89 end++;
90 }
91
92 /* Handle the sign, if any. */
93 if(end[0] == '-') {
94 is_negative = 1;
95 end++;
96 }
97 else if(end[0] == '+') {
98 end++;
99 }
100 else if(end[0] == '\0') {
101 /* We had nothing but perhaps some whitespace -- there was no number. */
102 if(endptr) {
103 *endptr = end;
104 }
105 return 0;
106 }
107
108 /* Handle special beginnings, if present and allowed. */
109 if(end[0] == '0' && end[1] == 'x') {
110 if(base == 16 || base == 0) {
111 end += 2;
112 base = 16;
113 }
114 }
115 else if(end[0] == '0') {
116 if(base == 8 || base == 0) {
117 end++;
118 base = 8;
119 }
120 }
121
122 /* Matching strtol, if the base is 0 and it doesn't look like
123 * the number is octal or hex, we assume it's base 10.
124 */
125 if(base == 0) {
126 base = 10;
127 }
128
129 /* Loop handling digits. */
130 value = 0;
131 overflow = 0;
132 for(i = get_char(end[0], base);
133 i != -1;
134 end++, i = get_char(end[0], base)) {
135 newval = base * value + i;
136 if(newval < value) {
137 /* We've overflowed. */
138 overflow = 1;
139 break;
140 }
141 else
142 value = newval;
143 }
144
145 if(!overflow) {
146 if(is_negative) {
147 /* Fix the sign. */
148 value *= -1;
149 }
150 }
151 else {
152 if(is_negative)
153 value = CURL_OFF_T_MIN;
154 else
155 value = CURL_OFF_T_MAX;
156
157 errno = ERANGE;
158 }
159
160 if(endptr)
161 *endptr = end;
162
163 return value;
164}
165
166/**
167 * Returns the value of c in the given base, or -1 if c cannot
168 * be interpreted properly in that base (i.e., is out of range,
169 * is a null, etc.).
170 *
171 * @param c the character to interpret according to base
172 * @param base the base in which to interpret c
173 *
174 * @return the value of c in base, or -1 if c isn't in range
175 */
176static int get_char(char c, int base)
177{
178#ifndef NO_RANGE_TEST
179 int value = -1;
180 if(c <= '9' && c >= '0') {
181 value = c - '0';
182 }
183 else if(c <= 'Z' && c >= 'A') {
184 value = c - 'A' + 10;
185 }
186 else if(c <= 'z' && c >= 'a') {
187 value = c - 'a' + 10;
188 }
189#else
190 const char *cp;
191 int value;
192
193 cp = memchr(valchars, c, 10 + 26 + 26);
194
195 if(!cp)
196 return -1;
197
198 value = cp - valchars;
199
200 if(value >= 10 + 26)
201 value -= 26; /* Lowercase. */
202#endif
203
204 if(value >= base) {
205 value = -1;
206 }
207
208 return value;
209}
210#endif /* Only present if we need strtoll, but don't have it. */
211
212/*
213 * Parse a *positive* up to 64 bit number written in ascii.
214 */
215CURLofft curlx_strtoofft(const char *str, char **endp, int base,
216 curl_off_t *num)
217{
218 char *end;
219 curl_off_t number;
220 errno = 0;
221 *num = 0; /* clear by default */
222
223 while(*str && ISSPACE(*str))
224 str++;
225 if('-' == *str) {
226 if(endp)
227 *endp = (char *)str; /* didn't actually move */
228 return CURL_OFFT_INVAL; /* nothing parsed */
229 }
230 number = strtooff(str, &end, base);
231 if(endp)
232 *endp = end;
233 if(errno == ERANGE)
234 /* overflow/underflow */
235 return CURL_OFFT_FLOW;
236 else if(str == end)
237 /* nothing parsed */
238 return CURL_OFFT_INVAL;
239
240 *num = number;
241 return CURL_OFFT_OK;
242}
243