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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, int len)
78{
79 const char *p;
80
81 if (fdt_version(fdt) >= 0x11)
82 if (((offset + len) < offset)
83 || ((offset + len) > fdt_size_dt_struct(fdt)))
84 return NULL;
85
86 p = _fdt_offset_ptr(fdt, offset);
87
88 if (p + len < p)
89 return NULL;
90 return p;
91}
92
93uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
94{
95 const uint32_t *tagp, *lenp;
96 uint32_t tag;
97 const char *p;
98
99 if (offset % FDT_TAGSIZE)
100 return -1;
101
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 switch (tag) {
109 case FDT_BEGIN_NODE:
110 /* skip name */
111 do {
112 p = fdt_offset_ptr(fdt, offset++, 1);
113 } while (p && (*p != '\0'));
114 if (! p)
115 return FDT_END;
116 break;
117 case FDT_PROP:
118 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
119 if (! lenp)
120 return FDT_END;
121 /* skip name offset, length and value */
122 offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
123 break;
124 }
125
126 if (nextoffset)
127 *nextoffset = FDT_TAGALIGN(offset);
128
129 return tag;
130}
131
132int _fdt_check_node_offset(const void *fdt, int offset)
133{
134 if ((offset < 0) || (offset % FDT_TAGSIZE)
135 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
136 return -FDT_ERR_BADOFFSET;
137
138 return offset;
139}
140
141int fdt_next_node(const void *fdt, int offset, int *depth)
142{
143 int nextoffset = 0;
144 uint32_t tag;
145
146 if (offset >= 0)
147 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
148 return nextoffset;
149
150 do {
151 offset = nextoffset;
152 tag = fdt_next_tag(fdt, offset, &nextoffset);
153
154 switch (tag) {
155 case FDT_PROP:
156 case FDT_NOP:
157 break;
158
159 case FDT_BEGIN_NODE:
160 if (depth)
161 (*depth)++;
162 break;
163
164 case FDT_END_NODE:
165 if (depth)
166 (*depth)--;
167 break;
168
169 case FDT_END:
170 return -FDT_ERR_NOTFOUND;
171
172 default:
173 return -FDT_ERR_BADSTRUCTURE;
174 }
175 } while (tag != FDT_BEGIN_NODE);
176
177 return offset;
178}
179
180const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
181{
182 int len = strlen(s) + 1;
183 const char *last = strtab + tabsize - len;
184 const char *p;
185
186 for (p = strtab; p <= last; p++)
187 if (memcmp(p, s, len) == 0)
188 return p;
189 return NULL;
190}
191
192int fdt_move(const void *fdt, void *buf, int bufsize)
193{
194 FDT_CHECK_HEADER(fdt);
195
196 if (fdt_totalsize(fdt) > bufsize)
197 return -FDT_ERR_NOSPACE;
198
199 memmove(buf, fdt, fdt_totalsize(fdt));
200 return 0;
201}
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 if (fdt_magic(fdt) == FDT_MAGIC) {
26 /* Complete tree */
27 if (!can_assume(LATEST)) {
28 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
29 return -FDT_ERR_BADVERSION;
30 if (fdt_last_comp_version(fdt) >
31 FDT_LAST_SUPPORTED_VERSION)
32 return -FDT_ERR_BADVERSION;
33 }
34 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
35 /* Unfinished sequential-write blob */
36 if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0)
37 return -FDT_ERR_BADSTATE;
38 } else {
39 return -FDT_ERR_BADMAGIC;
40 }
41
42 if (totalsize < INT32_MAX)
43 return totalsize;
44 else
45 return -FDT_ERR_TRUNCATED;
46}
47
48static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
49{
50 return (off >= hdrsize) && (off <= totalsize);
51}
52
53static int check_block_(uint32_t hdrsize, uint32_t totalsize,
54 uint32_t base, uint32_t size)
55{
56 if (!check_off_(hdrsize, totalsize, base))
57 return 0; /* block start out of bounds */
58 if ((base + size) < base)
59 return 0; /* overflow */
60 if (!check_off_(hdrsize, totalsize, base + size))
61 return 0; /* block end out of bounds */
62 return 1;
63}
64
65size_t fdt_header_size_(uint32_t version)
66{
67 if (version <= 1)
68 return FDT_V1_SIZE;
69 else if (version <= 2)
70 return FDT_V2_SIZE;
71 else if (version <= 3)
72 return FDT_V3_SIZE;
73 else if (version <= 16)
74 return FDT_V16_SIZE;
75 else
76 return FDT_V17_SIZE;
77}
78
79size_t fdt_header_size(const void *fdt)
80{
81 return can_assume(LATEST) ? FDT_V17_SIZE :
82 fdt_header_size_(fdt_version(fdt));
83}
84
85int fdt_check_header(const void *fdt)
86{
87 size_t hdrsize;
88
89 if (fdt_magic(fdt) != FDT_MAGIC)
90 return -FDT_ERR_BADMAGIC;
91 if (!can_assume(LATEST)) {
92 if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
93 || (fdt_last_comp_version(fdt) >
94 FDT_LAST_SUPPORTED_VERSION))
95 return -FDT_ERR_BADVERSION;
96 if (fdt_version(fdt) < fdt_last_comp_version(fdt))
97 return -FDT_ERR_BADVERSION;
98 }
99 hdrsize = fdt_header_size(fdt);
100 if (!can_assume(VALID_DTB)) {
101
102 if ((fdt_totalsize(fdt) < hdrsize)
103 || (fdt_totalsize(fdt) > INT_MAX))
104 return -FDT_ERR_TRUNCATED;
105
106 /* Bounds check memrsv block */
107 if (!check_off_(hdrsize, fdt_totalsize(fdt),
108 fdt_off_mem_rsvmap(fdt)))
109 return -FDT_ERR_TRUNCATED;
110 }
111
112 if (!can_assume(VALID_DTB)) {
113 /* Bounds check structure block */
114 if (!can_assume(LATEST) && fdt_version(fdt) < 17) {
115 if (!check_off_(hdrsize, fdt_totalsize(fdt),
116 fdt_off_dt_struct(fdt)))
117 return -FDT_ERR_TRUNCATED;
118 } else {
119 if (!check_block_(hdrsize, fdt_totalsize(fdt),
120 fdt_off_dt_struct(fdt),
121 fdt_size_dt_struct(fdt)))
122 return -FDT_ERR_TRUNCATED;
123 }
124
125 /* Bounds check strings block */
126 if (!check_block_(hdrsize, fdt_totalsize(fdt),
127 fdt_off_dt_strings(fdt),
128 fdt_size_dt_strings(fdt)))
129 return -FDT_ERR_TRUNCATED;
130 }
131
132 return 0;
133}
134
135const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
136{
137 unsigned absoffset = offset + fdt_off_dt_struct(fdt);
138
139 if (!can_assume(VALID_INPUT))
140 if ((absoffset < offset)
141 || ((absoffset + len) < absoffset)
142 || (absoffset + len) > fdt_totalsize(fdt))
143 return NULL;
144
145 if (can_assume(LATEST) || fdt_version(fdt) >= 0x11)
146 if (((offset + len) < offset)
147 || ((offset + len) > fdt_size_dt_struct(fdt)))
148 return NULL;
149
150 return fdt_offset_ptr_(fdt, offset);
151}
152
153uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
154{
155 const fdt32_t *tagp, *lenp;
156 uint32_t tag;
157 int offset = startoffset;
158 const char *p;
159
160 *nextoffset = -FDT_ERR_TRUNCATED;
161 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
162 if (!can_assume(VALID_DTB) && !tagp)
163 return FDT_END; /* premature end */
164 tag = fdt32_to_cpu(*tagp);
165 offset += FDT_TAGSIZE;
166
167 *nextoffset = -FDT_ERR_BADSTRUCTURE;
168 switch (tag) {
169 case FDT_BEGIN_NODE:
170 /* skip name */
171 do {
172 p = fdt_offset_ptr(fdt, offset++, 1);
173 } while (p && (*p != '\0'));
174 if (!can_assume(VALID_DTB) && !p)
175 return FDT_END; /* premature end */
176 break;
177
178 case FDT_PROP:
179 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
180 if (!can_assume(VALID_DTB) && !lenp)
181 return FDT_END; /* premature end */
182 /* skip-name offset, length and value */
183 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
184 + fdt32_to_cpu(*lenp);
185 if (!can_assume(LATEST) &&
186 fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
187 ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
188 offset += 4;
189 break;
190
191 case FDT_END:
192 case FDT_END_NODE:
193 case FDT_NOP:
194 break;
195
196 default:
197 return FDT_END;
198 }
199
200 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
201 return FDT_END; /* premature end */
202
203 *nextoffset = FDT_TAGALIGN(offset);
204 return tag;
205}
206
207int fdt_check_node_offset_(const void *fdt, int offset)
208{
209 if (can_assume(VALID_INPUT))
210 return offset;
211 if ((offset < 0) || (offset % FDT_TAGSIZE)
212 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
213 return -FDT_ERR_BADOFFSET;
214
215 return offset;
216}
217
218int fdt_check_prop_offset_(const void *fdt, int offset)
219{
220 if ((offset < 0) || (offset % FDT_TAGSIZE)
221 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
222 return -FDT_ERR_BADOFFSET;
223
224 return offset;
225}
226
227int fdt_next_node(const void *fdt, int offset, int *depth)
228{
229 int nextoffset = 0;
230 uint32_t tag;
231
232 if (offset >= 0)
233 if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
234 return nextoffset;
235
236 do {
237 offset = nextoffset;
238 tag = fdt_next_tag(fdt, offset, &nextoffset);
239
240 switch (tag) {
241 case FDT_PROP:
242 case FDT_NOP:
243 break;
244
245 case FDT_BEGIN_NODE:
246 if (depth)
247 (*depth)++;
248 break;
249
250 case FDT_END_NODE:
251 if (depth && ((--(*depth)) < 0))
252 return nextoffset;
253 break;
254
255 case FDT_END:
256 if ((nextoffset >= 0)
257 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
258 return -FDT_ERR_NOTFOUND;
259 else
260 return nextoffset;
261 }
262 } while (tag != FDT_BEGIN_NODE);
263
264 return offset;
265}
266
267int fdt_first_subnode(const void *fdt, int offset)
268{
269 int depth = 0;
270
271 offset = fdt_next_node(fdt, offset, &depth);
272 if (offset < 0 || depth != 1)
273 return -FDT_ERR_NOTFOUND;
274
275 return offset;
276}
277
278int fdt_next_subnode(const void *fdt, int offset)
279{
280 int depth = 1;
281
282 /*
283 * With respect to the parent, the depth of the next subnode will be
284 * the same as the last.
285 */
286 do {
287 offset = fdt_next_node(fdt, offset, &depth);
288 if (offset < 0 || depth < 1)
289 return -FDT_ERR_NOTFOUND;
290 } while (depth > 1);
291
292 return offset;
293}
294
295const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
296{
297 int len = strlen(s) + 1;
298 const char *last = strtab + tabsize - len;
299 const char *p;
300
301 for (p = strtab; p <= last; p++)
302 if (memcmp(p, s, len) == 0)
303 return p;
304 return NULL;
305}
306
307int fdt_move(const void *fdt, void *buf, int bufsize)
308{
309 FDT_RO_PROBE(fdt);
310
311 if (fdt_totalsize(fdt) > bufsize)
312 return -FDT_ERR_NOSPACE;
313
314 memmove(buf, fdt, fdt_totalsize(fdt));
315 return 0;
316}