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1/*
2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
4 *
5 * libfdt is dual licensed: you can use it either under the terms of
6 * the GPL, or the BSD license, at your option.
7 *
8 * a) This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public
19 * License along with this library; if not, write to the Free
20 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21 * MA 02110-1301 USA
22 *
23 * Alternatively,
24 *
25 * b) Redistribution and use in source and binary forms, with or
26 * without modification, are permitted provided that the following
27 * conditions are met:
28 *
29 * 1. Redistributions of source code must retain the above
30 * copyright notice, this list of conditions and the following
31 * disclaimer.
32 * 2. Redistributions in binary form must reproduce the above
33 * copyright notice, this list of conditions and the following
34 * disclaimer in the documentation and/or other materials
35 * provided with the distribution.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50 */
51#include "libfdt_env.h"
52
53#include <fdt.h>
54#include <libfdt.h>
55
56#include "libfdt_internal.h"
57
58int fdt_check_header(const void *fdt)
59{
60 if (fdt_magic(fdt) == FDT_MAGIC) {
61 /* Complete tree */
62 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
63 return -FDT_ERR_BADVERSION;
64 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
65 return -FDT_ERR_BADVERSION;
66 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
67 /* Unfinished sequential-write blob */
68 if (fdt_size_dt_struct(fdt) == 0)
69 return -FDT_ERR_BADSTATE;
70 } else {
71 return -FDT_ERR_BADMAGIC;
72 }
73
74 return 0;
75}
76
77const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
78{
79 unsigned absoffset = offset + fdt_off_dt_struct(fdt);
80
81 if ((absoffset < offset)
82 || ((absoffset + len) < absoffset)
83 || (absoffset + len) > fdt_totalsize(fdt))
84 return NULL;
85
86 if (fdt_version(fdt) >= 0x11)
87 if (((offset + len) < offset)
88 || ((offset + len) > fdt_size_dt_struct(fdt)))
89 return NULL;
90
91 return _fdt_offset_ptr(fdt, offset);
92}
93
94uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
95{
96 const fdt32_t *tagp, *lenp;
97 uint32_t tag;
98 int offset = startoffset;
99 const char *p;
100
101 *nextoffset = -FDT_ERR_TRUNCATED;
102 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
103 if (!tagp)
104 return FDT_END; /* premature end */
105 tag = fdt32_to_cpu(*tagp);
106 offset += FDT_TAGSIZE;
107
108 *nextoffset = -FDT_ERR_BADSTRUCTURE;
109 switch (tag) {
110 case FDT_BEGIN_NODE:
111 /* skip name */
112 do {
113 p = fdt_offset_ptr(fdt, offset++, 1);
114 } while (p && (*p != '\0'));
115 if (!p)
116 return FDT_END; /* premature end */
117 break;
118
119 case FDT_PROP:
120 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
121 if (!lenp)
122 return FDT_END; /* premature end */
123 /* skip-name offset, length and value */
124 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
125 + fdt32_to_cpu(*lenp);
126 break;
127
128 case FDT_END:
129 case FDT_END_NODE:
130 case FDT_NOP:
131 break;
132
133 default:
134 return FDT_END;
135 }
136
137 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
138 return FDT_END; /* premature end */
139
140 *nextoffset = FDT_TAGALIGN(offset);
141 return tag;
142}
143
144int _fdt_check_node_offset(const void *fdt, int offset)
145{
146 if ((offset < 0) || (offset % FDT_TAGSIZE)
147 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
148 return -FDT_ERR_BADOFFSET;
149
150 return offset;
151}
152
153int _fdt_check_prop_offset(const void *fdt, int offset)
154{
155 if ((offset < 0) || (offset % FDT_TAGSIZE)
156 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
157 return -FDT_ERR_BADOFFSET;
158
159 return offset;
160}
161
162int fdt_next_node(const void *fdt, int offset, int *depth)
163{
164 int nextoffset = 0;
165 uint32_t tag;
166
167 if (offset >= 0)
168 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
169 return nextoffset;
170
171 do {
172 offset = nextoffset;
173 tag = fdt_next_tag(fdt, offset, &nextoffset);
174
175 switch (tag) {
176 case FDT_PROP:
177 case FDT_NOP:
178 break;
179
180 case FDT_BEGIN_NODE:
181 if (depth)
182 (*depth)++;
183 break;
184
185 case FDT_END_NODE:
186 if (depth && ((--(*depth)) < 0))
187 return nextoffset;
188 break;
189
190 case FDT_END:
191 if ((nextoffset >= 0)
192 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
193 return -FDT_ERR_NOTFOUND;
194 else
195 return nextoffset;
196 }
197 } while (tag != FDT_BEGIN_NODE);
198
199 return offset;
200}
201
202int fdt_first_subnode(const void *fdt, int offset)
203{
204 int depth = 0;
205
206 offset = fdt_next_node(fdt, offset, &depth);
207 if (offset < 0 || depth != 1)
208 return -FDT_ERR_NOTFOUND;
209
210 return offset;
211}
212
213int fdt_next_subnode(const void *fdt, int offset)
214{
215 int depth = 1;
216
217 /*
218 * With respect to the parent, the depth of the next subnode will be
219 * the same as the last.
220 */
221 do {
222 offset = fdt_next_node(fdt, offset, &depth);
223 if (offset < 0 || depth < 1)
224 return -FDT_ERR_NOTFOUND;
225 } while (depth > 1);
226
227 return offset;
228}
229
230const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
231{
232 int len = strlen(s) + 1;
233 const char *last = strtab + tabsize - len;
234 const char *p;
235
236 for (p = strtab; p <= last; p++)
237 if (memcmp(p, s, len) == 0)
238 return p;
239 return NULL;
240}
241
242int fdt_move(const void *fdt, void *buf, int bufsize)
243{
244 FDT_CHECK_HEADER(fdt);
245
246 if (fdt_totalsize(fdt) > bufsize)
247 return -FDT_ERR_NOSPACE;
248
249 memmove(buf, fdt, fdt_totalsize(fdt));
250 return 0;
251}
1// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2/*
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 */
6#include "libfdt_env.h"
7
8#include <fdt.h>
9#include <libfdt.h>
10
11#include "libfdt_internal.h"
12
13/*
14 * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
15 * that the given buffer contains what appears to be a flattened
16 * device tree with sane information in its header.
17 */
18int32_t fdt_ro_probe_(const void *fdt)
19{
20 uint32_t totalsize = fdt_totalsize(fdt);
21
22 if (can_assume(VALID_DTB))
23 return totalsize;
24
25 /* The device tree must be at an 8-byte aligned address */
26 if ((uintptr_t)fdt & 7)
27 return -FDT_ERR_ALIGNMENT;
28
29 if (fdt_magic(fdt) == FDT_MAGIC) {
30 /* Complete tree */
31 if (!can_assume(LATEST)) {
32 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
33 return -FDT_ERR_BADVERSION;
34 if (fdt_last_comp_version(fdt) >
35 FDT_LAST_SUPPORTED_VERSION)
36 return -FDT_ERR_BADVERSION;
37 }
38 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
39 /* Unfinished sequential-write blob */
40 if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0)
41 return -FDT_ERR_BADSTATE;
42 } else {
43 return -FDT_ERR_BADMAGIC;
44 }
45
46 if (totalsize < INT32_MAX)
47 return totalsize;
48 else
49 return -FDT_ERR_TRUNCATED;
50}
51
52static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
53{
54 return (off >= hdrsize) && (off <= totalsize);
55}
56
57static int check_block_(uint32_t hdrsize, uint32_t totalsize,
58 uint32_t base, uint32_t size)
59{
60 if (!check_off_(hdrsize, totalsize, base))
61 return 0; /* block start out of bounds */
62 if ((base + size) < base)
63 return 0; /* overflow */
64 if (!check_off_(hdrsize, totalsize, base + size))
65 return 0; /* block end out of bounds */
66 return 1;
67}
68
69size_t fdt_header_size_(uint32_t version)
70{
71 if (version <= 1)
72 return FDT_V1_SIZE;
73 else if (version <= 2)
74 return FDT_V2_SIZE;
75 else if (version <= 3)
76 return FDT_V3_SIZE;
77 else if (version <= 16)
78 return FDT_V16_SIZE;
79 else
80 return FDT_V17_SIZE;
81}
82
83size_t fdt_header_size(const void *fdt)
84{
85 return can_assume(LATEST) ? FDT_V17_SIZE :
86 fdt_header_size_(fdt_version(fdt));
87}
88
89int fdt_check_header(const void *fdt)
90{
91 size_t hdrsize;
92
93 if (fdt_magic(fdt) != FDT_MAGIC)
94 return -FDT_ERR_BADMAGIC;
95 if (!can_assume(LATEST)) {
96 if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
97 || (fdt_last_comp_version(fdt) >
98 FDT_LAST_SUPPORTED_VERSION))
99 return -FDT_ERR_BADVERSION;
100 if (fdt_version(fdt) < fdt_last_comp_version(fdt))
101 return -FDT_ERR_BADVERSION;
102 }
103 hdrsize = fdt_header_size(fdt);
104 if (!can_assume(VALID_DTB)) {
105
106 if ((fdt_totalsize(fdt) < hdrsize)
107 || (fdt_totalsize(fdt) > INT_MAX))
108 return -FDT_ERR_TRUNCATED;
109
110 /* Bounds check memrsv block */
111 if (!check_off_(hdrsize, fdt_totalsize(fdt),
112 fdt_off_mem_rsvmap(fdt)))
113 return -FDT_ERR_TRUNCATED;
114 }
115
116 if (!can_assume(VALID_DTB)) {
117 /* Bounds check structure block */
118 if (!can_assume(LATEST) && fdt_version(fdt) < 17) {
119 if (!check_off_(hdrsize, fdt_totalsize(fdt),
120 fdt_off_dt_struct(fdt)))
121 return -FDT_ERR_TRUNCATED;
122 } else {
123 if (!check_block_(hdrsize, fdt_totalsize(fdt),
124 fdt_off_dt_struct(fdt),
125 fdt_size_dt_struct(fdt)))
126 return -FDT_ERR_TRUNCATED;
127 }
128
129 /* Bounds check strings block */
130 if (!check_block_(hdrsize, fdt_totalsize(fdt),
131 fdt_off_dt_strings(fdt),
132 fdt_size_dt_strings(fdt)))
133 return -FDT_ERR_TRUNCATED;
134 }
135
136 return 0;
137}
138
139const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
140{
141 unsigned int uoffset = offset;
142 unsigned int absoffset = offset + fdt_off_dt_struct(fdt);
143
144 if (offset < 0)
145 return NULL;
146
147 if (!can_assume(VALID_INPUT))
148 if ((absoffset < uoffset)
149 || ((absoffset + len) < absoffset)
150 || (absoffset + len) > fdt_totalsize(fdt))
151 return NULL;
152
153 if (can_assume(LATEST) || fdt_version(fdt) >= 0x11)
154 if (((uoffset + len) < uoffset)
155 || ((offset + len) > fdt_size_dt_struct(fdt)))
156 return NULL;
157
158 return fdt_offset_ptr_(fdt, offset);
159}
160
161uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
162{
163 const fdt32_t *tagp, *lenp;
164 uint32_t tag;
165 int offset = startoffset;
166 const char *p;
167
168 *nextoffset = -FDT_ERR_TRUNCATED;
169 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
170 if (!can_assume(VALID_DTB) && !tagp)
171 return FDT_END; /* premature end */
172 tag = fdt32_to_cpu(*tagp);
173 offset += FDT_TAGSIZE;
174
175 *nextoffset = -FDT_ERR_BADSTRUCTURE;
176 switch (tag) {
177 case FDT_BEGIN_NODE:
178 /* skip name */
179 do {
180 p = fdt_offset_ptr(fdt, offset++, 1);
181 } while (p && (*p != '\0'));
182 if (!can_assume(VALID_DTB) && !p)
183 return FDT_END; /* premature end */
184 break;
185
186 case FDT_PROP:
187 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
188 if (!can_assume(VALID_DTB) && !lenp)
189 return FDT_END; /* premature end */
190 /* skip-name offset, length and value */
191 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
192 + fdt32_to_cpu(*lenp);
193 if (!can_assume(LATEST) &&
194 fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
195 ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
196 offset += 4;
197 break;
198
199 case FDT_END:
200 case FDT_END_NODE:
201 case FDT_NOP:
202 break;
203
204 default:
205 return FDT_END;
206 }
207
208 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
209 return FDT_END; /* premature end */
210
211 *nextoffset = FDT_TAGALIGN(offset);
212 return tag;
213}
214
215int fdt_check_node_offset_(const void *fdt, int offset)
216{
217 if (!can_assume(VALID_INPUT)
218 && ((offset < 0) || (offset % FDT_TAGSIZE)))
219 return -FDT_ERR_BADOFFSET;
220
221 if (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)
222 return -FDT_ERR_BADOFFSET;
223
224 return offset;
225}
226
227int fdt_check_prop_offset_(const void *fdt, int offset)
228{
229 if (!can_assume(VALID_INPUT)
230 && ((offset < 0) || (offset % FDT_TAGSIZE)))
231 return -FDT_ERR_BADOFFSET;
232
233 if (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)
234 return -FDT_ERR_BADOFFSET;
235
236 return offset;
237}
238
239int fdt_next_node(const void *fdt, int offset, int *depth)
240{
241 int nextoffset = 0;
242 uint32_t tag;
243
244 if (offset >= 0)
245 if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
246 return nextoffset;
247
248 do {
249 offset = nextoffset;
250 tag = fdt_next_tag(fdt, offset, &nextoffset);
251
252 switch (tag) {
253 case FDT_PROP:
254 case FDT_NOP:
255 break;
256
257 case FDT_BEGIN_NODE:
258 if (depth)
259 (*depth)++;
260 break;
261
262 case FDT_END_NODE:
263 if (depth && ((--(*depth)) < 0))
264 return nextoffset;
265 break;
266
267 case FDT_END:
268 if ((nextoffset >= 0)
269 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
270 return -FDT_ERR_NOTFOUND;
271 else
272 return nextoffset;
273 }
274 } while (tag != FDT_BEGIN_NODE);
275
276 return offset;
277}
278
279int fdt_first_subnode(const void *fdt, int offset)
280{
281 int depth = 0;
282
283 offset = fdt_next_node(fdt, offset, &depth);
284 if (offset < 0 || depth != 1)
285 return -FDT_ERR_NOTFOUND;
286
287 return offset;
288}
289
290int fdt_next_subnode(const void *fdt, int offset)
291{
292 int depth = 1;
293
294 /*
295 * With respect to the parent, the depth of the next subnode will be
296 * the same as the last.
297 */
298 do {
299 offset = fdt_next_node(fdt, offset, &depth);
300 if (offset < 0 || depth < 1)
301 return -FDT_ERR_NOTFOUND;
302 } while (depth > 1);
303
304 return offset;
305}
306
307const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
308{
309 int len = strlen(s) + 1;
310 const char *last = strtab + tabsize - len;
311 const char *p;
312
313 for (p = strtab; p <= last; p++)
314 if (memcmp(p, s, len) == 0)
315 return p;
316 return NULL;
317}
318
319int fdt_move(const void *fdt, void *buf, int bufsize)
320{
321 if (!can_assume(VALID_INPUT) && bufsize < 0)
322 return -FDT_ERR_NOSPACE;
323
324 FDT_RO_PROBE(fdt);
325
326 if (fdt_totalsize(fdt) > (unsigned int)bufsize)
327 return -FDT_ERR_NOSPACE;
328
329 memmove(buf, fdt, fdt_totalsize(fdt));
330 return 0;
331}