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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 const DATA_BLOB data_blob_null = { NULL, 0, NULL };
  25
  26 /*******************************************************************
  27  Free() a data blob.
  28 *******************************************************************/
  29
  30 static void free_data_blob(DATA_BLOB *d)
  31 {
  32         if ((d) && (d->free)) {
  33                 SAFE_FREE(d->data);
  34         }
  35 }
  36
  37 /*******************************************************************
  38  Construct a data blob, must be freed with data_blob_free().
  39  You can pass NULL for p and get a blank data blob
  40 *******************************************************************/
  41
  42 DATA_BLOB data_blob(const void *p, size_t length)
  43 {
  44         DATA_BLOB ret;
  45
  46         if (!length) {
  47                 ZERO_STRUCT(ret);
  48                 return ret;
  49         }
  50
  51         if (p) {
  52                 ret.data = (uint8 *)smb_xmemdup(p, length);
  53         } else {
  54                 ret.data = SMB_XMALLOC_ARRAY(uint8, length);
  55         }
  56         ret.length = length;
  57         ret.free = free_data_blob;
  58         return ret;
  59 }
  60
  61 /*******************************************************************
  62  Construct a data blob, using supplied TALLOC_CTX.
  63 *******************************************************************/
  64
  65 DATA_BLOB data_blob_talloc(TALLOC_CTX *mem_ctx, const void *p, size_t length)
  66 {
  67         DATA_BLOB ret;
  68
  69         if (!length) {
  70                 ZERO_STRUCT(ret);
  71                 return ret;
  72         }
  73
  74         if (p) {
  75                 ret.data = (uint8 *)TALLOC_MEMDUP(mem_ctx, p, length);
  76                 if (ret.data == NULL)
  77                         smb_panic("data_blob_talloc: TALLOC_MEMDUP failed");
  78         } else {
  79                 ret.data = (uint8 *)TALLOC(mem_ctx, length);
  80                 if (ret.data == NULL)
  81                         smb_panic("data_blob_talloc: TALLOC failed");
  82         }
  83
  84         ret.length = length;
  85         ret.free = NULL;
  86         return ret;
  87 }
  88
  89 /*******************************************************************
  90  Free a data blob.
  91 *******************************************************************/
  92
  93 void data_blob_free(DATA_BLOB *d)
  94 {
  95         if (d) {
  96                 if (d->free) {
  97                         (d->free)(d);
  98                 }
  99                 d->length = 0;
 100         }
 101 }
 102
 103 /*******************************************************************
 104  Clear a DATA_BLOB's contents
 105 *******************************************************************/
 106
 107 void data_blob_clear(DATA_BLOB *d)
 108 {
 109         if (d->data) {
 110                 memset(d->data, 0, d->length);
 111         }
 112 }
 113
 114 /*******************************************************************
 115  Free a data blob and clear its contents
 116 *******************************************************************/
 117
 118 void data_blob_clear_free(DATA_BLOB *d)
 119 {
 120         data_blob_clear(d);
 121         data_blob_free(d);
 122 }
 123
 124 /**
 125   useful for constructing data blobs in test suites, while
 126   avoiding const warnings
 127 **/
 128 DATA_BLOB data_blob_string_const(const char *str)
 129 {
 130         DATA_BLOB blob;
 131         blob.data = CONST_DISCARD(uint8 *, str);
 132         blob.length = strlen(str);
 133         blob.free = NULL;
 134         return blob;
 135 }
 136
 137 /**
 138  * Create a new data blob from const data
 139  */
 140 DATA_BLOB data_blob_const(const void *p, size_t length)
 141 {
 142         DATA_BLOB blob;
 143         blob.data = CONST_DISCARD(uint8 *, p);
 144         blob.length = length;
 145         blob.free = NULL;
 146         return blob;
 147 }