summaryrefslogtreecommitdiff
path: root/source4/librpc/ndr/ndr.c
blob: 2ab78d3d091796c5bcf2bbca297695dabbb03392 (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
/* 
   Unix SMB/CIFS implementation.

   libndr interface

   Copyright (C) Andrew Tridgell 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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
  this provides the core routines for NDR parsing functions

  see http://www.opengroup.org/onlinepubs/9629399/chap14.htm for details
  of NDR encoding rules
*/

#include "includes.h"

#define NDR_BASE_MARSHALL_SIZE 1024

/*
  initialise a ndr parse structure from a data blob
*/
struct ndr_pull *ndr_pull_init_blob(DATA_BLOB *blob, TALLOC_CTX *mem_ctx)
{
	struct ndr_pull *ndr;

	ndr = talloc(mem_ctx, sizeof(*ndr));
	if (!ndr) return NULL;

	ndr->flags = 0;
	ndr->data = blob->data;
	ndr->data_size = blob->length;
	ndr->offset = 0;
	ndr->mem_ctx = mem_ctx;

	return ndr;
}


/* limit the remaining size of the current ndr parse structure to the
   given size, starting at the given offset 

   this is used when a ndr packet has an explicit size on the wire, and we
   need to make sure that we don't use more data than is indicated

   the 'ofs' parameter indicates how many bytes back from the current
   offset in the buffer the 'size' number of bytes starts
*/
NTSTATUS ndr_pull_limit_size(struct ndr_pull *ndr, uint32 size, uint32 ofs)
{
	uint32 new_size;
	new_size = ndr->offset + size - ofs;

	if (new_size > ndr->data_size) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}
	ndr->data_size = new_size;

	return NT_STATUS_OK;
}


/*
  advance by 'size' bytes
*/
NTSTATUS ndr_pull_advance(struct ndr_pull *ndr, uint32 size)
{
	ndr->offset += size;
	if (ndr->offset > ndr->data_size) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}
	return NT_STATUS_OK;
}

/*
  set the parse offset to 'ofs'
*/
NTSTATUS ndr_pull_set_offset(struct ndr_pull *ndr, uint32 ofs)
{
	ndr->offset = ofs;
	if (ndr->offset > ndr->data_size) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}
	return NT_STATUS_OK;
}

/* save the offset/size of the current ndr state */
void ndr_pull_save(struct ndr_pull *ndr, struct ndr_pull_save *save)
{
	save->offset = ndr->offset;
	save->data_size = ndr->data_size;
}

/* restore the size/offset of a ndr structure */
void ndr_pull_restore(struct ndr_pull *ndr, struct ndr_pull_save *save)
{
	ndr->offset = save->offset;
	ndr->data_size = save->data_size;
}




/* create a ndr_push structure, ready for some marshalling */
struct ndr_push *ndr_push_init(void)
{
	struct ndr_push *ndr;
	TALLOC_CTX *mem_ctx = talloc_init("ndr_push_init");
	if (!mem_ctx) return NULL;

	ndr = talloc(mem_ctx, sizeof(*ndr));
	if (!ndr) {
		talloc_destroy(mem_ctx);
		return NULL;
	}

	ndr->mem_ctx = mem_ctx;
	ndr->flags = 0;
	ndr->alloc_size = NDR_BASE_MARSHALL_SIZE;
	ndr->data = talloc(ndr->mem_ctx, ndr->alloc_size);
	if (!ndr->data) {
		ndr_push_free(ndr);
		return NULL;
	}
	ndr->offset = 0;
	
	return ndr;
}

/* free a ndr_push structure */
void ndr_push_free(struct ndr_push *ndr)
{
	talloc_destroy(ndr->mem_ctx);
}


/* return a DATA_BLOB structure for the current ndr_push marshalled data */
DATA_BLOB ndr_push_blob(struct ndr_push *ndr)
{
	DATA_BLOB blob;
	blob.data = ndr->data;
	blob.length = ndr->offset;
	return blob;
}


/*
  expand the available space in the buffer to 'size'
*/
NTSTATUS ndr_push_expand(struct ndr_push *ndr, uint32 size)
{
	if (ndr->alloc_size >= size) {
		return NT_STATUS_OK;
	}

	ndr->alloc_size = size;
	ndr->data = talloc_realloc(ndr->mem_ctx, ndr->data, ndr->alloc_size);
	if (!ndr->data) {
		return NT_STATUS_NO_MEMORY;
	}

	return NT_STATUS_OK;
}

/*
  set the push offset to 'ofs'
*/
NTSTATUS ndr_push_set_offset(struct ndr_push *ndr, uint32 ofs)
{
	NDR_CHECK(ndr_push_expand(ndr, ofs));
	ndr->offset = ofs;
	return NT_STATUS_OK;
}

/*
  push a generic array
*/
NTSTATUS ndr_push_array(struct ndr_push *ndr, int ndr_flags, void *base, 
			size_t elsize, uint32 count, 
			NTSTATUS (*push_fn)(struct ndr_push *, int, void *))
{
	int i;
	char *p = base;
	NDR_CHECK(ndr_push_uint32(ndr, count));
	if (!(ndr_flags & NDR_SCALARS)) goto buffers;
	for (i=0;i<count;i++) {
		NDR_CHECK(push_fn(ndr, NDR_SCALARS, p));
		p += elsize;
	}
	if (!(ndr_flags & NDR_BUFFERS)) goto done;
buffers:
	p = base;
	for (i=0;i<count;i++) {
		NDR_CHECK(push_fn(ndr, NDR_BUFFERS, p));
		p += elsize;
	}
done:
	return NT_STATUS_OK;
}

/*
  pull a generic array
*/
NTSTATUS ndr_pull_array(struct ndr_pull *ndr, int ndr_flags, void *base, 
			size_t elsize, uint32 count, 
			NTSTATUS (*pull_fn)(struct ndr_pull *, int, void *))
{
	int i;
	uint32 max_count;
	char *p;
	p = base;
	NDR_CHECK(ndr_pull_uint32(ndr, &max_count));
	if (max_count != count) {
		/* maybe we can cope with this? */
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (!(ndr_flags & NDR_SCALARS)) goto buffers;
	for (i=0;i<count;i++) {
		NDR_CHECK(pull_fn(ndr, NDR_SCALARS, p));
		p += elsize;
	}
	if (!(ndr_flags & NDR_BUFFERS)) goto done;
buffers:
	p = base;
	for (i=0;i<count;i++) {
		NDR_CHECK(pull_fn(ndr, NDR_BUFFERS, p));
		p += elsize;
	}
done:
	return NT_STATUS_OK;
}