source/lib/data_blob.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Easy management of byte-length data
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Andrew Bartlett 2001
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 const DATA_BLOB data_blob_null = { NULL, 0, NULL };
  24
  25 /*******************************************************************
  26  Free() a data blob.
  27 *******************************************************************/
  28
  29 static void free_data_blob(DATA_BLOB *d)
  30 {
  31         if ((d) && (d->free)) {
  32                 SAFE_FREE(d->data);
  33         }
  34 }
  35
  36 /*******************************************************************
  37  Construct a data blob, must be freed with data_blob_free().
  38  You can pass NULL for p and get a blank data blob
  39 *******************************************************************/
  40
  41 DATA_BLOB data_blob(const void *p, size_t length)
  42 {
  43         DATA_BLOB ret;
  44
  45         if (!length) {
  46                 ZERO_STRUCT(ret);
  47                 return ret;
  48         }
  49
  50         if (p) {
  51                 ret.data = (uint8 *)smb_xmemdup(p, length);
  52         } else {
  53                 ret.data = SMB_XMALLOC_ARRAY(uint8, length);
  54         }
  55         ret.length = length;
  56         ret.free = free_data_blob;
  57         return ret;
  58 }
  59
  60 /*******************************************************************
  61  Construct a data blob, using supplied TALLOC_CTX.
  62 *******************************************************************/
  63
  64 DATA_BLOB data_blob_talloc(TALLOC_CTX *mem_ctx, const void *p, size_t length)
  65 {
  66         DATA_BLOB ret;
  67
  68         if (!length) {
  69                 ZERO_STRUCT(ret);
  70                 return ret;
  71         }
  72
  73         if (p) {
  74                 ret.data = (uint8 *)TALLOC_MEMDUP(mem_ctx, p, length);
  75                 if (ret.data == NULL)
  76                         smb_panic("data_blob_talloc: TALLOC_MEMDUP failed");
  77         } else {
  78                 ret.data = (uint8 *)TALLOC(mem_ctx, length);
  79                 if (ret.data == NULL)
  80                         smb_panic("data_blob_talloc: TALLOC failed");
  81         }
  82
  83         ret.length = length;
  84         ret.free = NULL;
  85         return ret;
  86 }
  87
  88 /*******************************************************************
  89  Free a data blob.
  90 *******************************************************************/
  91
  92 void data_blob_free(DATA_BLOB *d)
  93 {
  94         if (d) {
  95                 if (d->free) {
  96                         (d->free)(d);
  97                 }
  98                 d->length = 0;
  99         }
 100 }
 101
 102 /*******************************************************************
 103  Clear a DATA_BLOB's contents
 104 *******************************************************************/
 105
 106 void data_blob_clear(DATA_BLOB *d)
 107 {
 108         if (d->data) {
 109                 memset(d->data, 0, d->length);
 110         }
 111 }
 112
 113 /*******************************************************************
 114  Free a data blob and clear its contents
 115 *******************************************************************/
 116
 117 void data_blob_clear_free(DATA_BLOB *d)
 118 {
 119         data_blob_clear(d);
 120         data_blob_free(d);
 121 }
 122
 123 /**
 124   useful for constructing data blobs in test suites, while
 125   avoiding const warnings
 126 **/
 127 DATA_BLOB data_blob_string_const(const char *str)
 128 {
 129         DATA_BLOB blob;
 130         blob.data = CONST_DISCARD(uint8 *, str);
 131         blob.length = strlen(str) + 1;
 132         blob.free = NULL;
 133         return blob;
 134 }
 135
 136 /**
 137  * Create a new data blob from const data
 138  */
 139 DATA_BLOB data_blob_const(const void *p, size_t length)
 140 {
 141         DATA_BLOB blob;
 142         blob.data = CONST_DISCARD(uint8 *, p);
 143         blob.length = length;
 144         blob.free = NULL;
 145         return blob;
 146 }
 147
 148 /**
 149  construct a zero data blob, using supplied TALLOC_CTX.
 150  use this sparingly as it initialises data - better to initialise
 151  yourself if you want specific data in the blob
 152 **/
 153 DATA_BLOB data_blob_talloc_zero(TALLOC_CTX *mem_ctx, size_t length)
 154 {
 155         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, length);
 156         data_blob_clear(&blob);
 157         return blob;
 158 }