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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 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 startoffset, int *nextoffset)
94{
95 const uint32_t *tagp, *lenp;
96 uint32_t tag;
97 int offset = startoffset;
98 const char *p;
99
100 *nextoffset = -FDT_ERR_TRUNCATED;
101 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
102 if (!tagp)
103 return FDT_END; /* premature end */
104 tag = fdt32_to_cpu(*tagp);
105 offset += FDT_TAGSIZE;
106
107 *nextoffset = -FDT_ERR_BADSTRUCTURE;
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; /* premature end */
116 break;
117
118 case FDT_PROP:
119 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
120 if (!lenp)
121 return FDT_END; /* premature end */
122 /* skip-name offset, length and value */
123 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
124 + fdt32_to_cpu(*lenp);
125 break;
126
127 case FDT_END:
128 case FDT_END_NODE:
129 case FDT_NOP:
130 break;
131
132 default:
133 return FDT_END;
134 }
135
136 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
137 return FDT_END; /* premature end */
138
139 *nextoffset = FDT_TAGALIGN(offset);
140 return tag;
141}
142
143int _fdt_check_node_offset(const void *fdt, int offset)
144{
145 if ((offset < 0) || (offset % FDT_TAGSIZE)
146 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
147 return -FDT_ERR_BADOFFSET;
148
149 return offset;
150}
151
152int _fdt_check_prop_offset(const void *fdt, int offset)
153{
154 if ((offset < 0) || (offset % FDT_TAGSIZE)
155 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
156 return -FDT_ERR_BADOFFSET;
157
158 return offset;
159}
160
161int fdt_next_node(const void *fdt, int offset, int *depth)
162{
163 int nextoffset = 0;
164 uint32_t tag;
165
166 if (offset >= 0)
167 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
168 return nextoffset;
169
170 do {
171 offset = nextoffset;
172 tag = fdt_next_tag(fdt, offset, &nextoffset);
173
174 switch (tag) {
175 case FDT_PROP:
176 case FDT_NOP:
177 break;
178
179 case FDT_BEGIN_NODE:
180 if (depth)
181 (*depth)++;
182 break;
183
184 case FDT_END_NODE:
185 if (depth && ((--(*depth)) < 0))
186 return nextoffset;
187 break;
188
189 case FDT_END:
190 if ((nextoffset >= 0)
191 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
192 return -FDT_ERR_NOTFOUND;
193 else
194 return nextoffset;
195 }
196 } while (tag != FDT_BEGIN_NODE);
197
198 return offset;
199}
200
201const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
202{
203 int len = strlen(s) + 1;
204 const char *last = strtab + tabsize - len;
205 const char *p;
206
207 for (p = strtab; p <= last; p++)
208 if (memcmp(p, s, len) == 0)
209 return p;
210 return NULL;
211}
212
213int fdt_move(const void *fdt, void *buf, int bufsize)
214{
215 FDT_CHECK_HEADER(fdt);
216
217 if (fdt_totalsize(fdt) > bufsize)
218 return -FDT_ERR_NOSPACE;
219
220 memmove(buf, fdt, fdt_totalsize(fdt));
221 return 0;
222}
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 */
18int fdt_ro_probe_(const void *fdt)
19{
20 if (fdt_magic(fdt) == FDT_MAGIC) {
21 /* Complete tree */
22 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
23 return -FDT_ERR_BADVERSION;
24 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
25 return -FDT_ERR_BADVERSION;
26 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
27 /* Unfinished sequential-write blob */
28 if (fdt_size_dt_struct(fdt) == 0)
29 return -FDT_ERR_BADSTATE;
30 } else {
31 return -FDT_ERR_BADMAGIC;
32 }
33
34 return 0;
35}
36
37static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
38{
39 return (off >= hdrsize) && (off <= totalsize);
40}
41
42static int check_block_(uint32_t hdrsize, uint32_t totalsize,
43 uint32_t base, uint32_t size)
44{
45 if (!check_off_(hdrsize, totalsize, base))
46 return 0; /* block start out of bounds */
47 if ((base + size) < base)
48 return 0; /* overflow */
49 if (!check_off_(hdrsize, totalsize, base + size))
50 return 0; /* block end out of bounds */
51 return 1;
52}
53
54size_t fdt_header_size_(uint32_t version)
55{
56 if (version <= 1)
57 return FDT_V1_SIZE;
58 else if (version <= 2)
59 return FDT_V2_SIZE;
60 else if (version <= 3)
61 return FDT_V3_SIZE;
62 else if (version <= 16)
63 return FDT_V16_SIZE;
64 else
65 return FDT_V17_SIZE;
66}
67
68int fdt_check_header(const void *fdt)
69{
70 size_t hdrsize;
71
72 if (fdt_magic(fdt) != FDT_MAGIC)
73 return -FDT_ERR_BADMAGIC;
74 hdrsize = fdt_header_size(fdt);
75 if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
76 || (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION))
77 return -FDT_ERR_BADVERSION;
78 if (fdt_version(fdt) < fdt_last_comp_version(fdt))
79 return -FDT_ERR_BADVERSION;
80
81 if ((fdt_totalsize(fdt) < hdrsize)
82 || (fdt_totalsize(fdt) > INT_MAX))
83 return -FDT_ERR_TRUNCATED;
84
85 /* Bounds check memrsv block */
86 if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt)))
87 return -FDT_ERR_TRUNCATED;
88
89 /* Bounds check structure block */
90 if (fdt_version(fdt) < 17) {
91 if (!check_off_(hdrsize, fdt_totalsize(fdt),
92 fdt_off_dt_struct(fdt)))
93 return -FDT_ERR_TRUNCATED;
94 } else {
95 if (!check_block_(hdrsize, fdt_totalsize(fdt),
96 fdt_off_dt_struct(fdt),
97 fdt_size_dt_struct(fdt)))
98 return -FDT_ERR_TRUNCATED;
99 }
100
101 /* Bounds check strings block */
102 if (!check_block_(hdrsize, fdt_totalsize(fdt),
103 fdt_off_dt_strings(fdt), fdt_size_dt_strings(fdt)))
104 return -FDT_ERR_TRUNCATED;
105
106 return 0;
107}
108
109const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
110{
111 unsigned absoffset = offset + fdt_off_dt_struct(fdt);
112
113 if ((absoffset < offset)
114 || ((absoffset + len) < absoffset)
115 || (absoffset + len) > fdt_totalsize(fdt))
116 return NULL;
117
118 if (fdt_version(fdt) >= 0x11)
119 if (((offset + len) < offset)
120 || ((offset + len) > fdt_size_dt_struct(fdt)))
121 return NULL;
122
123 return fdt_offset_ptr_(fdt, offset);
124}
125
126uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
127{
128 const fdt32_t *tagp, *lenp;
129 uint32_t tag;
130 int offset = startoffset;
131 const char *p;
132
133 *nextoffset = -FDT_ERR_TRUNCATED;
134 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
135 if (!tagp)
136 return FDT_END; /* premature end */
137 tag = fdt32_to_cpu(*tagp);
138 offset += FDT_TAGSIZE;
139
140 *nextoffset = -FDT_ERR_BADSTRUCTURE;
141 switch (tag) {
142 case FDT_BEGIN_NODE:
143 /* skip name */
144 do {
145 p = fdt_offset_ptr(fdt, offset++, 1);
146 } while (p && (*p != '\0'));
147 if (!p)
148 return FDT_END; /* premature end */
149 break;
150
151 case FDT_PROP:
152 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
153 if (!lenp)
154 return FDT_END; /* premature end */
155 /* skip-name offset, length and value */
156 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
157 + fdt32_to_cpu(*lenp);
158 if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
159 ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
160 offset += 4;
161 break;
162
163 case FDT_END:
164 case FDT_END_NODE:
165 case FDT_NOP:
166 break;
167
168 default:
169 return FDT_END;
170 }
171
172 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
173 return FDT_END; /* premature end */
174
175 *nextoffset = FDT_TAGALIGN(offset);
176 return tag;
177}
178
179int fdt_check_node_offset_(const void *fdt, int offset)
180{
181 if ((offset < 0) || (offset % FDT_TAGSIZE)
182 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
183 return -FDT_ERR_BADOFFSET;
184
185 return offset;
186}
187
188int fdt_check_prop_offset_(const void *fdt, int offset)
189{
190 if ((offset < 0) || (offset % FDT_TAGSIZE)
191 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
192 return -FDT_ERR_BADOFFSET;
193
194 return offset;
195}
196
197int fdt_next_node(const void *fdt, int offset, int *depth)
198{
199 int nextoffset = 0;
200 uint32_t tag;
201
202 if (offset >= 0)
203 if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
204 return nextoffset;
205
206 do {
207 offset = nextoffset;
208 tag = fdt_next_tag(fdt, offset, &nextoffset);
209
210 switch (tag) {
211 case FDT_PROP:
212 case FDT_NOP:
213 break;
214
215 case FDT_BEGIN_NODE:
216 if (depth)
217 (*depth)++;
218 break;
219
220 case FDT_END_NODE:
221 if (depth && ((--(*depth)) < 0))
222 return nextoffset;
223 break;
224
225 case FDT_END:
226 if ((nextoffset >= 0)
227 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
228 return -FDT_ERR_NOTFOUND;
229 else
230 return nextoffset;
231 }
232 } while (tag != FDT_BEGIN_NODE);
233
234 return offset;
235}
236
237int fdt_first_subnode(const void *fdt, int offset)
238{
239 int depth = 0;
240
241 offset = fdt_next_node(fdt, offset, &depth);
242 if (offset < 0 || depth != 1)
243 return -FDT_ERR_NOTFOUND;
244
245 return offset;
246}
247
248int fdt_next_subnode(const void *fdt, int offset)
249{
250 int depth = 1;
251
252 /*
253 * With respect to the parent, the depth of the next subnode will be
254 * the same as the last.
255 */
256 do {
257 offset = fdt_next_node(fdt, offset, &depth);
258 if (offset < 0 || depth < 1)
259 return -FDT_ERR_NOTFOUND;
260 } while (depth > 1);
261
262 return offset;
263}
264
265const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
266{
267 int len = strlen(s) + 1;
268 const char *last = strtab + tabsize - len;
269 const char *p;
270
271 for (p = strtab; p <= last; p++)
272 if (memcmp(p, s, len) == 0)
273 return p;
274 return NULL;
275}
276
277int fdt_move(const void *fdt, void *buf, int bufsize)
278{
279 FDT_RO_PROBE(fdt);
280
281 if (fdt_totalsize(fdt) > bufsize)
282 return -FDT_ERR_NOSPACE;
283
284 memmove(buf, fdt, fdt_totalsize(fdt));
285 return 0;
286}