lib/util/smb_strtox.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  *
   4  * Copyright (C) Swen Schillig 2019
   5  *
   6  *   ** NOTE! The following LGPL license applies to this file.
   7  *   ** This does NOT imply that all of Samba is released
   8  *   ** under the LGPL
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 3 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "replace.h"
  25 #include "smb_strtox.h"
  26
  27 /**
  28  * Convert a string to an unsigned long integer
  29  *
  30  * @param nptr          pointer to string which is to be converted
  31  * @param endptr        [optional] reference to remainder of the string
  32  * @param base          base of the numbering scheme
  33  * @param err           error occurred during conversion
  34  * @flags               controlling conversion feature
  35  * @result              result of the conversion as provided by strtoul
  36  *
  37  * The following flags are supported
  38  *      SMB_STR_STANDARD # raise error if negative or non-numeric
  39  *      SMB_STR_ALLOW_NEGATIVE # allow strings with a leading "-"
  40  *      SMB_STR_FULL_STR_CONV # entire string must be converted
  41  *      SMB_STR_ALLOW_NO_CONVERSION # allow empty strings or non-numeric
  42  *      SMB_STR_GLIBC_STANDARD # act exactly as the standard glibc strtoul
  43  *
  44  * The following errors are detected
  45  * - wrong base
  46  * - value overflow
  47  * - string with a leading "-" indicating a negative number
  48  * - no conversion due to empty string or not representing a number
  49  */
  50 unsigned long int
  51 smb_strtoul(const char *nptr, char **endptr, int base, int *err, int flags)
  52 {
  53         unsigned long int val;
  54         int saved_errno = errno;
  55         char *needle = NULL;
  56         char *tmp_endptr = NULL;
  57
  58         errno = 0;
  59         *err = 0;
  60
  61         val = strtoul(nptr, &tmp_endptr, base);
  62
  63         if (endptr != NULL) {
  64                 *endptr = tmp_endptr;
  65         }
  66
  67         if (errno != 0) {
  68                 *err = errno;
  69                 errno = saved_errno;
  70                 return val;
  71         }
  72
  73         if ((flags & SMB_STR_ALLOW_NO_CONVERSION) == 0) {
  74                 /* got an invalid number-string resulting in no conversion */
  75                 if (nptr == tmp_endptr) {
  76                         *err = EINVAL;
  77                         goto out;
  78                 }
  79         }
  80
  81         if ((flags & SMB_STR_ALLOW_NEGATIVE ) == 0) {
  82                 /* did we convert a negative "number" ? */
  83                 needle = strchr(nptr, '-');
  84                 if (needle != NULL && needle < tmp_endptr) {
  85                         *err = EINVAL;
  86                         goto out;
  87                 }
  88         }
  89
  90         if ((flags & SMB_STR_FULL_STR_CONV) != 0) {
  91                 /* did we convert the entire string ? */
  92                 if (tmp_endptr[0] != '\0') {
  93                         *err = EINVAL;
  94                         goto out;
  95                 }
  96         }
  97
  98 out:
  99         errno = saved_errno;
 100         return val;
 101 }
 102
 103 /**
 104  * Convert a string to an unsigned long long integer
 105  *
 106  * @param nptr          pointer to string which is to be converted
 107  * @param endptr        [optional] reference to remainder of the string
 108  * @param base          base of the numbering scheme
 109  * @param err           error occurred during conversion
 110  * @flags               controlling conversion feature
 111  * @result              result of the conversion as provided by strtoull
 112  *
 113  * The following flags are supported
 114  *      SMB_STR_STANDARD # raise error if negative or non-numeric
 115  *      SMB_STR_ALLOW_NEGATIVE # allow strings with a leading "-"
 116  *      SMB_STR_FULL_STR_CONV # entire string must be converted
 117  *      SMB_STR_ALLOW_NO_CONVERSION # allow empty strings or non-numeric
 118  *      SMB_STR_GLIBC_STANDARD # act exactly as the standard glibc strtoul
 119  *
 120  * The following errors are detected
 121  * - wrong base
 122  * - value overflow
 123  * - string with a leading "-" indicating a negative number
 124  * - no conversion due to empty string or not representing a number
 125  */
 126 unsigned long long int
 127 smb_strtoull(const char *nptr, char **endptr, int base, int *err, int flags)
 128 {
 129         unsigned long long int val;
 130         int saved_errno = errno;
 131         char *needle = NULL;
 132         char *tmp_endptr = NULL;
 133
 134         errno = 0;
 135         *err = 0;
 136
 137         val = strtoull(nptr, &tmp_endptr, base);
 138
 139         if (endptr != NULL) {
 140                 *endptr = tmp_endptr;
 141         }
 142
 143         if (errno != 0) {
 144                 *err = errno;
 145                 errno = saved_errno;
 146                 return val;
 147         }
 148
 149         if ((flags & SMB_STR_ALLOW_NO_CONVERSION) == 0) {
 150                 /* got an invalid number-string resulting in no conversion */
 151                 if (nptr == tmp_endptr) {
 152                         *err = EINVAL;
 153                         goto out;
 154                 }
 155         }
 156
 157         if ((flags & SMB_STR_ALLOW_NEGATIVE ) == 0) {
 158                 /* did we convert a negative "number" ? */
 159                 needle = strchr(nptr, '-');
 160                 if (needle != NULL && needle < tmp_endptr) {
 161                         *err = EINVAL;
 162                         goto out;
 163                 }
 164         }
 165
 166         if ((flags & SMB_STR_FULL_STR_CONV) != 0) {
 167                 /* did we convert the entire string ? */
 168                 if (tmp_endptr[0] != '\0') {
 169                         *err = EINVAL;
 170                         goto out;
 171                 }
 172         }
 173
 174 out:
 175         errno = saved_errno;
 176         return val;
 177 }