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 | |
58 | /* |
59 | * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks |
60 | * that the given buffer contains what appears to be a flattened |
61 | * device tree with sane information in its header. |
62 | */ |
63 | int fdt_ro_probe_(const void *fdt) |
64 | { |
65 | if (fdt_magic(fdt) == FDT_MAGIC) { |
66 | /* Complete tree */ |
67 | if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) |
68 | return -FDT_ERR_BADVERSION; |
69 | if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION) |
70 | return -FDT_ERR_BADVERSION; |
71 | } else if (fdt_magic(fdt) == FDT_SW_MAGIC) { |
72 | /* Unfinished sequential-write blob */ |
73 | if (fdt_size_dt_struct(fdt) == 0) |
74 | return -FDT_ERR_BADSTATE; |
75 | } else { |
76 | return -FDT_ERR_BADMAGIC; |
77 | } |
78 | |
79 | return 0; |
80 | } |
81 | |
82 | static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off) |
83 | { |
84 | return (off >= hdrsize) && (off <= totalsize); |
85 | } |
86 | |
87 | static int check_block_(uint32_t hdrsize, uint32_t totalsize, |
88 | uint32_t base, uint32_t size) |
89 | { |
90 | if (!check_off_(hdrsize, totalsize, base)) |
91 | return 0; /* block start out of bounds */ |
92 | if ((base + size) < base) |
93 | return 0; /* overflow */ |
94 | if (!check_off_(hdrsize, totalsize, base + size)) |
95 | return 0; /* block end out of bounds */ |
96 | return 1; |
97 | } |
98 | |
99 | size_t (uint32_t version) |
100 | { |
101 | if (version <= 1) |
102 | return FDT_V1_SIZE; |
103 | else if (version <= 2) |
104 | return FDT_V2_SIZE; |
105 | else if (version <= 3) |
106 | return FDT_V3_SIZE; |
107 | else if (version <= 16) |
108 | return FDT_V16_SIZE; |
109 | else |
110 | return FDT_V17_SIZE; |
111 | } |
112 | |
113 | int (const void *fdt) |
114 | { |
115 | size_t hdrsize; |
116 | |
117 | if (fdt_magic(fdt) != FDT_MAGIC) |
118 | return -FDT_ERR_BADMAGIC; |
119 | hdrsize = fdt_header_size(fdt); |
120 | if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) |
121 | || (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)) |
122 | return -FDT_ERR_BADVERSION; |
123 | if (fdt_version(fdt) < fdt_last_comp_version(fdt)) |
124 | return -FDT_ERR_BADVERSION; |
125 | |
126 | if ((fdt_totalsize(fdt) < hdrsize) |
127 | || (fdt_totalsize(fdt) > INT_MAX)) |
128 | return -FDT_ERR_TRUNCATED; |
129 | |
130 | /* Bounds check memrsv block */ |
131 | if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt))) |
132 | return -FDT_ERR_TRUNCATED; |
133 | |
134 | /* Bounds check structure block */ |
135 | if (fdt_version(fdt) < 17) { |
136 | if (!check_off_(hdrsize, fdt_totalsize(fdt), |
137 | fdt_off_dt_struct(fdt))) |
138 | return -FDT_ERR_TRUNCATED; |
139 | } else { |
140 | if (!check_block_(hdrsize, fdt_totalsize(fdt), |
141 | fdt_off_dt_struct(fdt), |
142 | fdt_size_dt_struct(fdt))) |
143 | return -FDT_ERR_TRUNCATED; |
144 | } |
145 | |
146 | /* Bounds check strings block */ |
147 | if (!check_block_(hdrsize, fdt_totalsize(fdt), |
148 | fdt_off_dt_strings(fdt), fdt_size_dt_strings(fdt))) |
149 | return -FDT_ERR_TRUNCATED; |
150 | |
151 | return 0; |
152 | } |
153 | |
154 | const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len) |
155 | { |
156 | unsigned absoffset = offset + fdt_off_dt_struct(fdt); |
157 | |
158 | if ((absoffset < offset) |
159 | || ((absoffset + len) < absoffset) |
160 | || (absoffset + len) > fdt_totalsize(fdt)) |
161 | return NULL; |
162 | |
163 | if (fdt_version(fdt) >= 0x11) |
164 | if (((offset + len) < offset) |
165 | || ((offset + len) > fdt_size_dt_struct(fdt))) |
166 | return NULL; |
167 | |
168 | return fdt_offset_ptr_(fdt, offset); |
169 | } |
170 | |
171 | uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) |
172 | { |
173 | const fdt32_t *tagp, *lenp; |
174 | uint32_t tag; |
175 | int offset = startoffset; |
176 | const char *p; |
177 | |
178 | *nextoffset = -FDT_ERR_TRUNCATED; |
179 | tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE); |
180 | if (!tagp) |
181 | return FDT_END; /* premature end */ |
182 | tag = fdt32_to_cpu(*tagp); |
183 | offset += FDT_TAGSIZE; |
184 | |
185 | *nextoffset = -FDT_ERR_BADSTRUCTURE; |
186 | switch (tag) { |
187 | case FDT_BEGIN_NODE: |
188 | /* skip name */ |
189 | do { |
190 | p = fdt_offset_ptr(fdt, offset++, 1); |
191 | } while (p && (*p != '\0')); |
192 | if (!p) |
193 | return FDT_END; /* premature end */ |
194 | break; |
195 | |
196 | case FDT_PROP: |
197 | lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp)); |
198 | if (!lenp) |
199 | return FDT_END; /* premature end */ |
200 | /* skip-name offset, length and value */ |
201 | offset += sizeof(struct fdt_property) - FDT_TAGSIZE |
202 | + fdt32_to_cpu(*lenp); |
203 | if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 && |
204 | ((offset - fdt32_to_cpu(*lenp)) % 8) != 0) |
205 | offset += 4; |
206 | break; |
207 | |
208 | case FDT_END: |
209 | case FDT_END_NODE: |
210 | case FDT_NOP: |
211 | break; |
212 | |
213 | default: |
214 | return FDT_END; |
215 | } |
216 | |
217 | if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset)) |
218 | return FDT_END; /* premature end */ |
219 | |
220 | *nextoffset = FDT_TAGALIGN(offset); |
221 | return tag; |
222 | } |
223 | |
224 | int fdt_check_node_offset_(const void *fdt, int offset) |
225 | { |
226 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
227 | || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)) |
228 | return -FDT_ERR_BADOFFSET; |
229 | |
230 | return offset; |
231 | } |
232 | |
233 | int fdt_check_prop_offset_(const void *fdt, int offset) |
234 | { |
235 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
236 | || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)) |
237 | return -FDT_ERR_BADOFFSET; |
238 | |
239 | return offset; |
240 | } |
241 | |
242 | int fdt_next_node(const void *fdt, int offset, int *depth) |
243 | { |
244 | int nextoffset = 0; |
245 | uint32_t tag; |
246 | |
247 | if (offset >= 0) |
248 | if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0) |
249 | return nextoffset; |
250 | |
251 | do { |
252 | offset = nextoffset; |
253 | tag = fdt_next_tag(fdt, offset, &nextoffset); |
254 | |
255 | switch (tag) { |
256 | case FDT_PROP: |
257 | case FDT_NOP: |
258 | break; |
259 | |
260 | case FDT_BEGIN_NODE: |
261 | if (depth) |
262 | (*depth)++; |
263 | break; |
264 | |
265 | case FDT_END_NODE: |
266 | if (depth && ((--(*depth)) < 0)) |
267 | return nextoffset; |
268 | break; |
269 | |
270 | case FDT_END: |
271 | if ((nextoffset >= 0) |
272 | || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth)) |
273 | return -FDT_ERR_NOTFOUND; |
274 | else |
275 | return nextoffset; |
276 | } |
277 | } while (tag != FDT_BEGIN_NODE); |
278 | |
279 | return offset; |
280 | } |
281 | |
282 | int fdt_first_subnode(const void *fdt, int offset) |
283 | { |
284 | int depth = 0; |
285 | |
286 | offset = fdt_next_node(fdt, offset, &depth); |
287 | if (offset < 0 || depth != 1) |
288 | return -FDT_ERR_NOTFOUND; |
289 | |
290 | return offset; |
291 | } |
292 | |
293 | int fdt_next_subnode(const void *fdt, int offset) |
294 | { |
295 | int depth = 1; |
296 | |
297 | /* |
298 | * With respect to the parent, the depth of the next subnode will be |
299 | * the same as the last. |
300 | */ |
301 | do { |
302 | offset = fdt_next_node(fdt, offset, &depth); |
303 | if (offset < 0 || depth < 1) |
304 | return -FDT_ERR_NOTFOUND; |
305 | } while (depth > 1); |
306 | |
307 | return offset; |
308 | } |
309 | |
310 | const char *fdt_find_string_(const char *strtab, int tabsize, const char *s) |
311 | { |
312 | int len = strlen(s) + 1; |
313 | const char *last = strtab + tabsize - len; |
314 | const char *p; |
315 | |
316 | for (p = strtab; p <= last; p++) |
317 | if (memcmp(p, s, len) == 0) |
318 | return p; |
319 | return NULL; |
320 | } |
321 | |
322 | int fdt_move(const void *fdt, void *buf, int bufsize) |
323 | { |
324 | FDT_RO_PROBE(fdt); |
325 | |
326 | if (fdt_totalsize(fdt) > bufsize) |
327 | return -FDT_ERR_NOSPACE; |
328 | |
329 | memmove(buf, fdt, fdt_totalsize(fdt)); |
330 | return 0; |
331 | } |
332 | |