summaryrefslogtreecommitdiffstats
path: root/source3/registry/reg_parse_prs.c
blob: 14aa3fac0181653e939732de513f721fa65f9d7a (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
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
/*
   Unix SMB/CIFS implementation.
   Samba memory buffer functions
   Copyright (C) Andrew Tridgell              1992-1997
   Copyright (C) Luke Kenneth Casson Leighton 1996-1997
   Copyright (C) Jeremy Allison               1999
   Copyright (C) Andrew Bartlett              2003.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "reg_parse_prs.h"
#include "rpc_dce.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_RPC_PARSE

/*******************************************************************
 Debug output for parsing info

 XXXX side-effect of this function is to increase the debug depth XXXX.

********************************************************************/

void prs_debug(prs_struct *ps, int depth, const char *desc, const char *fn_name)
{
	DEBUG(5+depth, ("%s%06x %s %s\n", tab_depth(5+depth,depth), ps->data_offset, fn_name, desc));
}

/**
 * Initialise an expandable parse structure.
 *
 * @param size Initial buffer size.  If >0, a new buffer will be
 * created with talloc().
 *
 * @return False if allocation fails, otherwise True.
 **/

bool prs_init(prs_struct *ps, uint32 size, TALLOC_CTX *ctx, bool io)
{
	ZERO_STRUCTP(ps);
	ps->io = io;
	ps->bigendian_data = RPC_LITTLE_ENDIAN;
	ps->align = RPC_PARSE_ALIGN;
	ps->is_dynamic = False;
	ps->data_offset = 0;
	ps->buffer_size = 0;
	ps->data_p = NULL;
	ps->mem_ctx = ctx;

	if (size != 0) {
		ps->buffer_size = size;
		ps->data_p = (char *)talloc_zero_size(ps->mem_ctx, size);
		if(ps->data_p == NULL) {
			DEBUG(0,("prs_init: talloc fail for %u bytes.\n", (unsigned int)size));
			return False;
		}
		ps->is_dynamic = True; /* We own this memory. */
	} else if (MARSHALLING(ps)) {
		/* If size is zero and we're marshalling we should allocate memory on demand. */
		ps->is_dynamic = True;
	}

	return True;
}

/*******************************************************************
 Delete the memory in a parse structure - if we own it.

 NOTE: Contrary to the somewhat confusing naming, this function is not
       intended for freeing memory allocated by prs_alloc_mem().
       That memory is also attached to the talloc context given by
       ps->mem_ctx, but is only freed when that talloc context is
       freed. prs_mem_free() is used to delete "dynamic" memory
       allocated in marshalling/unmarshalling.
 ********************************************************************/

void prs_mem_free(prs_struct *ps)
{
	if(ps->is_dynamic) {
		TALLOC_FREE(ps->data_p);
	}
	ps->is_dynamic = False;
	ps->buffer_size = 0;
	ps->data_offset = 0;
}

/*******************************************************************
 Allocate memory when unmarshalling... Always zero clears.
 ********************************************************************/

#if defined(PARANOID_MALLOC_CHECKER)
char *prs_alloc_mem_(prs_struct *ps, size_t size, unsigned int count)
#else
char *prs_alloc_mem(prs_struct *ps, size_t size, unsigned int count)
#endif
{
	char *ret = NULL;

	if (size && count) {
		/* We can't call the type-safe version here. */
		ret = (char *)_talloc_zero_array(ps->mem_ctx, size, count,
						 "parse_prs");
	}
	return ret;
}

/*******************************************************************
 Return the current talloc context we're using.
 ********************************************************************/

TALLOC_CTX *prs_get_mem_context(prs_struct *ps)
{
	return ps->mem_ctx;
}

/*******************************************************************
 Attempt, if needed, to grow a data buffer.
 Also depends on the data stream mode (io).
 ********************************************************************/

bool prs_grow(prs_struct *ps, uint32 extra_space)
{
	uint32 new_size;

	ps->grow_size = MAX(ps->grow_size, ps->data_offset + extra_space);

	if(ps->data_offset + extra_space <= ps->buffer_size)
		return True;

	/*
	 * We cannot grow the buffer if we're not reading
	 * into the prs_struct, or if we don't own the memory.
	 */

	if(UNMARSHALLING(ps) || !ps->is_dynamic) {
		DEBUG(0,("prs_grow: Buffer overflow - unable to expand buffer by %u bytes.\n",
				(unsigned int)extra_space));
		return False;
	}

	/*
	 * Decide how much extra space we really need.
	 */

	extra_space -= (ps->buffer_size - ps->data_offset);
	if(ps->buffer_size == 0) {

		/*
		 * Start with 128 bytes (arbitrary value), enough for small rpc
		 * requests
		 */
		new_size = MAX(128, extra_space);

		ps->data_p = (char *)talloc_zero_size(ps->mem_ctx, new_size);
		if(ps->data_p == NULL) {
			DEBUG(0,("prs_grow: talloc failure for size %u.\n", (unsigned int)new_size));
			return False;
		}
	} else {
		/*
		 * If the current buffer size is bigger than the space needed,
		 * just double it, else add extra_space. Always keep 64 bytes
		 * more, so that after we added a large blob we don't have to
		 * realloc immediately again.
		 */
		new_size = MAX(ps->buffer_size*2,
			       ps->buffer_size + extra_space + 64);

		ps->data_p = talloc_realloc(ps->mem_ctx,
						ps->data_p,
						char,
						new_size);
		if (ps->data_p == NULL) {
			DEBUG(0,("prs_grow: Realloc failure for size %u.\n",
				(unsigned int)new_size));
			return False;
		}

		memset(&ps->data_p[ps->buffer_size], '\0', (size_t)(new_size - ps->buffer_size));
	}
	ps->buffer_size = new_size;

	return True;
}

/*******************************************************************
 Get the data pointer (external interface).
********************************************************************/

char *prs_data_p(prs_struct *ps)
{
	return ps->data_p;
}

/*******************************************************************
 Get the current data size (external interface).
 ********************************************************************/

uint32 prs_data_size(prs_struct *ps)
{
	return ps->buffer_size;
}

/*******************************************************************
 Fetch the current offset (external interface).
 ********************************************************************/

uint32 prs_offset(prs_struct *ps)
{
	return ps->data_offset;
}

/*******************************************************************
 Set the current offset (external interface).
 ********************************************************************/

bool prs_set_offset(prs_struct *ps, uint32 offset)
{
	if ((offset > ps->data_offset)
	    && !prs_grow(ps, offset - ps->data_offset)) {
		return False;
	}

	ps->data_offset = offset;
	return True;
}

/*******************************************************************
 Append the data from a buffer into a parse_struct.
 ********************************************************************/

bool prs_copy_data_in(prs_struct *dst, const char *src, uint32 len)
{
	if (len == 0)
		return True;

	if(!prs_grow(dst, len))
		return False;

	memcpy(&dst->data_p[dst->data_offset], src, (size_t)len);
	dst->data_offset += len;

	return True;
}

/*******************************************************************
 Align a the data_len to a multiple of align bytes - filling with
 zeros.
 ********************************************************************/

bool prs_align(prs_struct *ps)
{
	uint32 mod = ps->data_offset & (ps->align-1);

	if (ps->align != 0 && mod != 0) {
		uint32 extra_space = (ps->align - mod);
		if(!prs_grow(ps, extra_space))
			return False;
		memset(&ps->data_p[ps->data_offset], '\0', (size_t)extra_space);
		ps->data_offset += extra_space;
	}

	return True;
}

/******************************************************************
 Align on a 8 byte boundary
 *****************************************************************/

bool prs_align_uint64(prs_struct *ps)
{
	bool ret;
	uint8 old_align = ps->align;

	ps->align = 8;
	ret = prs_align(ps);
	ps->align = old_align;

	return ret;
}

/*******************************************************************
 Ensure we can read/write to a given offset.
 ********************************************************************/

char *prs_mem_get(prs_struct *ps, uint32 extra_size)
{
	if(UNMARSHALLING(ps)) {
		/*
		 * If reading, ensure that we can read the requested size item.
		 */
		if (ps->data_offset + extra_size > ps->buffer_size) {
			DEBUG(0,("prs_mem_get: reading data of size %u would overrun "
				"buffer by %u bytes.\n",
				(unsigned int)extra_size,
				(unsigned int)(ps->data_offset + extra_size - ps->buffer_size) ));
			return NULL;
		}
	} else {
		/*
		 * Writing - grow the buffer if needed.
		 */
		if(!prs_grow(ps, extra_size))
			return NULL;
	}
	return &ps->data_p[ps->data_offset];
}

/*******************************************************************
 Change the struct type.
 ********************************************************************/

void prs_switch_type(prs_struct *ps, bool io)
{
	if ((ps->io ^ io) == True)
		ps->io=io;
}

/*******************************************************************
 Stream a uint16.
 ********************************************************************/

bool prs_uint16(const char *name, prs_struct *ps, int depth, uint16 *data16)
{
	char *q = prs_mem_get(ps, sizeof(uint16));
	if (q == NULL)
		return False;

	if (UNMARSHALLING(ps)) {
		if (ps->bigendian_data)
			*data16 = RSVAL(q,0);
		else
			*data16 = SVAL(q,0);
	} else {
		if (ps->bigendian_data)
			RSSVAL(q,0,*data16);
		else
			SSVAL(q,0,*data16);
	}

	DEBUGADD(5,("%s%04x %s: %04x\n", tab_depth(5,depth), ps->data_offset, name, *data16));

	ps->data_offset += sizeof(uint16);

	return True;
}

/*******************************************************************
 Stream a uint32.
 ********************************************************************/

bool prs_uint32(const char *name, prs_struct *ps, int depth, uint32 *data32)
{
	char *q = prs_mem_get(ps, sizeof(uint32));
	if (q == NULL)
		return False;

	if (UNMARSHALLING(ps)) {
		if (ps->bigendian_data)
			*data32 = RIVAL(q,0);
		else
			*data32 = IVAL(q,0);
	} else {
		if (ps->bigendian_data)
			RSIVAL(q,0,*data32);
		else
			SIVAL(q,0,*data32);
	}

	DEBUGADD(5,("%s%04x %s: %08x\n", tab_depth(5,depth), ps->data_offset, name, *data32));

	ps->data_offset += sizeof(uint32);

	return True;
}

/*******************************************************************
 Stream a uint64_struct
 ********************************************************************/
bool prs_uint64(const char *name, prs_struct *ps, int depth, uint64 *data64)
{
	if (UNMARSHALLING(ps)) {
		uint32 high, low;

		if (!prs_uint32(name, ps, depth+1, &low))
			return False;

		if (!prs_uint32(name, ps, depth+1, &high))
			return False;

		*data64 = ((uint64_t)high << 32) + low;

		return True;
	} else {
		uint32 high = (*data64) >> 32, low = (*data64) & 0xFFFFFFFF;
		return prs_uint32(name, ps, depth+1, &low) &&
			   prs_uint32(name, ps, depth+1, &high);
	}
}

/******************************************************************
 Stream an array of uint8s. Length is number of uint8s.
 ********************************************************************/

bool prs_uint8s(bool charmode, const char *name, prs_struct *ps, int depth, uint8 *data8s, int len)
{
	int i;
	char *q = prs_mem_get(ps, len);
	if (q == NULL)
		return False;

	if (UNMARSHALLING(ps)) {
		for (i = 0; i < len; i++)
			data8s[i] = CVAL(q,i);
	} else {
		for (i = 0; i < len; i++)
			SCVAL(q, i, data8s[i]);
	}

	DEBUGADD(5,("%s%04x %s: ", tab_depth(5,depth), ps->data_offset ,name));
	if (charmode)
		print_asc(5, (unsigned char*)data8s, len);
	else {
		for (i = 0; i < len; i++)
			DEBUGADD(5,("%02x ", data8s[i]));
	}
	DEBUGADD(5,("\n"));

	ps->data_offset += len;

	return True;
}