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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 
_fdt_blocks_misordered(const void * fdt,int mem_rsv_size,int struct_size)58 static int _fdt_blocks_misordered(const void *fdt,
59 			      int mem_rsv_size, int struct_size)
60 {
61 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
62 		|| (fdt_off_dt_struct(fdt) <
63 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
64 		|| (fdt_off_dt_strings(fdt) <
65 		    (fdt_off_dt_struct(fdt) + struct_size))
66 		|| (fdt_totalsize(fdt) <
67 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
68 }
69 
_fdt_rw_check_header(void * fdt)70 static int _fdt_rw_check_header(void *fdt)
71 {
72 	FDT_CHECK_HEADER(fdt);
73 
74 	if (fdt_version(fdt) < 17)
75 		return -FDT_ERR_BADVERSION;
76 	if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
77 				   fdt_size_dt_struct(fdt)))
78 		return -FDT_ERR_BADLAYOUT;
79 	if (fdt_version(fdt) > 17)
80 		fdt_set_version(fdt, 17);
81 
82 	return 0;
83 }
84 
85 #define FDT_RW_CHECK_HEADER(fdt) \
86 	{ \
87 		int __err; \
88 		if ((__err = _fdt_rw_check_header(fdt)) != 0) \
89 			return __err; \
90 	}
91 
_fdt_data_size(void * fdt)92 static inline int _fdt_data_size(void *fdt)
93 {
94 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
95 }
96 
_fdt_splice(void * fdt,void * splicepoint,int oldlen,int newlen)97 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
98 {
99 	char *p = splicepoint;
100 	char *end = (char *)fdt + _fdt_data_size(fdt);
101 
102 	if (((p + oldlen) < p) || ((p + oldlen) > end))
103 		return -FDT_ERR_BADOFFSET;
104 	if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt))
105 		return -FDT_ERR_BADOFFSET;
106 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
107 		return -FDT_ERR_NOSPACE;
108 	memmove(p + newlen, p + oldlen, end - p - oldlen);
109 	return 0;
110 }
111 
_fdt_splice_mem_rsv(void * fdt,struct fdt_reserve_entry * p,int oldn,int newn)112 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
113 			       int oldn, int newn)
114 {
115 	int delta = (newn - oldn) * sizeof(*p);
116 	int err;
117 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
118 	if (err)
119 		return err;
120 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
121 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
122 	return 0;
123 }
124 
_fdt_splice_struct(void * fdt,void * p,int oldlen,int newlen)125 static int _fdt_splice_struct(void *fdt, void *p,
126 			      int oldlen, int newlen)
127 {
128 	int delta = newlen - oldlen;
129 	int err;
130 
131 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
132 		return err;
133 
134 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
135 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
136 	return 0;
137 }
138 
_fdt_splice_string(void * fdt,int newlen)139 static int _fdt_splice_string(void *fdt, int newlen)
140 {
141 	void *p = (char *)fdt
142 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
143 	int err;
144 
145 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
146 		return err;
147 
148 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
149 	return 0;
150 }
151 
_fdt_find_add_string(void * fdt,const char * s)152 static int _fdt_find_add_string(void *fdt, const char *s)
153 {
154 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
155 	const char *p;
156 	char *new;
157 	int len = strlen(s) + 1;
158 	int err;
159 
160 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
161 	if (p)
162 		/* found it */
163 		return (p - strtab);
164 
165 	new = strtab + fdt_size_dt_strings(fdt);
166 	err = _fdt_splice_string(fdt, len);
167 	if (err)
168 		return err;
169 
170 	memcpy(new, s, len);
171 	return (new - strtab);
172 }
173 
fdt_add_mem_rsv(void * fdt,uint64_t address,uint64_t size)174 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
175 {
176 	struct fdt_reserve_entry *re;
177 	int err;
178 
179 	FDT_RW_CHECK_HEADER(fdt);
180 
181 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
182 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
183 	if (err)
184 		return err;
185 
186 	re->address = cpu_to_fdt64(address);
187 	re->size = cpu_to_fdt64(size);
188 	return 0;
189 }
190 
fdt_del_mem_rsv(void * fdt,int n)191 int fdt_del_mem_rsv(void *fdt, int n)
192 {
193 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
194 
195 	FDT_RW_CHECK_HEADER(fdt);
196 
197 	if (n >= fdt_num_mem_rsv(fdt))
198 		return -FDT_ERR_NOTFOUND;
199 
200 	return _fdt_splice_mem_rsv(fdt, re, 1, 0);
201 }
202 
_fdt_resize_property(void * fdt,int nodeoffset,const char * name,int len,struct fdt_property ** prop)203 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
204 				int len, struct fdt_property **prop)
205 {
206 	int oldlen;
207 	int err;
208 
209 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
210 	if (! (*prop))
211 		return oldlen;
212 
213 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
214 				      FDT_TAGALIGN(len))))
215 		return err;
216 
217 	(*prop)->len = cpu_to_fdt32(len);
218 	return 0;
219 }
220 
_fdt_add_property(void * fdt,int nodeoffset,const char * name,int len,struct fdt_property ** prop)221 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
222 			     int len, struct fdt_property **prop)
223 {
224 	int proplen;
225 	int nextoffset;
226 	int namestroff;
227 	int err;
228 
229 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
230 		return nextoffset;
231 
232 	namestroff = _fdt_find_add_string(fdt, name);
233 	if (namestroff < 0)
234 		return namestroff;
235 
236 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
237 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
238 
239 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
240 	if (err)
241 		return err;
242 
243 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
244 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
245 	(*prop)->len = cpu_to_fdt32(len);
246 	return 0;
247 }
248 
fdt_set_name(void * fdt,int nodeoffset,const char * name)249 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
250 {
251 	char *namep;
252 	int oldlen, newlen;
253 	int err;
254 
255 	FDT_RW_CHECK_HEADER(fdt);
256 
257 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
258 	if (!namep)
259 		return oldlen;
260 
261 	newlen = strlen(name);
262 
263 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
264 				 FDT_TAGALIGN(newlen+1));
265 	if (err)
266 		return err;
267 
268 	memcpy(namep, name, newlen+1);
269 	return 0;
270 }
271 
fdt_setprop(void * fdt,int nodeoffset,const char * name,const void * val,int len)272 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
273 		const void *val, int len)
274 {
275 	struct fdt_property *prop;
276 	int err;
277 
278 	FDT_RW_CHECK_HEADER(fdt);
279 
280 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
281 	if (err == -FDT_ERR_NOTFOUND)
282 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
283 	if (err)
284 		return err;
285 
286 	if (len)
287 		memcpy(prop->data, val, len);
288 	return 0;
289 }
290 
fdt_appendprop(void * fdt,int nodeoffset,const char * name,const void * val,int len)291 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
292 		   const void *val, int len)
293 {
294 	struct fdt_property *prop;
295 	int err, oldlen, newlen;
296 
297 	FDT_RW_CHECK_HEADER(fdt);
298 
299 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
300 	if (prop) {
301 		newlen = len + oldlen;
302 		err = _fdt_splice_struct(fdt, prop->data,
303 					 FDT_TAGALIGN(oldlen),
304 					 FDT_TAGALIGN(newlen));
305 		if (err)
306 			return err;
307 		prop->len = cpu_to_fdt32(newlen);
308 		memcpy(prop->data + oldlen, val, len);
309 	} else {
310 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
311 		if (err)
312 			return err;
313 		memcpy(prop->data, val, len);
314 	}
315 	return 0;
316 }
317 
fdt_delprop(void * fdt,int nodeoffset,const char * name)318 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
319 {
320 	struct fdt_property *prop;
321 	int len, proplen;
322 
323 	FDT_RW_CHECK_HEADER(fdt);
324 
325 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
326 	if (! prop)
327 		return len;
328 
329 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
330 	return _fdt_splice_struct(fdt, prop, proplen, 0);
331 }
332 
fdt_add_subnode_namelen(void * fdt,int parentoffset,const char * name,int namelen)333 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
334 			    const char *name, int namelen)
335 {
336 	struct fdt_node_header *nh;
337 	int offset, nextoffset;
338 	int nodelen;
339 	int err;
340 	uint32_t tag;
341 	fdt32_t *endtag;
342 
343 	FDT_RW_CHECK_HEADER(fdt);
344 
345 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
346 	if (offset >= 0)
347 		return -FDT_ERR_EXISTS;
348 	else if (offset != -FDT_ERR_NOTFOUND)
349 		return offset;
350 
351 	/* Try to place the new node after the parent's properties */
352 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
353 	do {
354 		offset = nextoffset;
355 		tag = fdt_next_tag(fdt, offset, &nextoffset);
356 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
357 
358 	nh = _fdt_offset_ptr_w(fdt, offset);
359 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
360 
361 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
362 	if (err)
363 		return err;
364 
365 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
366 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
367 	memcpy(nh->name, name, namelen);
368 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
369 	*endtag = cpu_to_fdt32(FDT_END_NODE);
370 
371 	return offset;
372 }
373 
fdt_add_subnode(void * fdt,int parentoffset,const char * name)374 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
375 {
376 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
377 }
378 
fdt_del_node(void * fdt,int nodeoffset)379 int fdt_del_node(void *fdt, int nodeoffset)
380 {
381 	int endoffset;
382 
383 	FDT_RW_CHECK_HEADER(fdt);
384 
385 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
386 	if (endoffset < 0)
387 		return endoffset;
388 
389 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
390 				  endoffset - nodeoffset, 0);
391 }
392 
_fdt_packblocks(const char * old,char * new,int mem_rsv_size,int struct_size)393 static void _fdt_packblocks(const char *old, char *new,
394 			    int mem_rsv_size, int struct_size)
395 {
396 	int mem_rsv_off, struct_off, strings_off;
397 
398 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
399 	struct_off = mem_rsv_off + mem_rsv_size;
400 	strings_off = struct_off + struct_size;
401 
402 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
403 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
404 
405 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
406 	fdt_set_off_dt_struct(new, struct_off);
407 	fdt_set_size_dt_struct(new, struct_size);
408 
409 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
410 		fdt_size_dt_strings(old));
411 	fdt_set_off_dt_strings(new, strings_off);
412 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
413 }
414 
fdt_open_into(const void * fdt,void * buf,int bufsize)415 int fdt_open_into(const void *fdt, void *buf, int bufsize)
416 {
417 	int err;
418 	int mem_rsv_size, struct_size;
419 	int newsize;
420 	const char *fdtstart = fdt;
421 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
422 	char *tmp;
423 
424 	FDT_CHECK_HEADER(fdt);
425 
426 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
427 		* sizeof(struct fdt_reserve_entry);
428 
429 	if (fdt_version(fdt) >= 17) {
430 		struct_size = fdt_size_dt_struct(fdt);
431 	} else {
432 		struct_size = 0;
433 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
434 			;
435 		if (struct_size < 0)
436 			return struct_size;
437 	}
438 
439 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
440 		/* no further work necessary */
441 		err = fdt_move(fdt, buf, bufsize);
442 		if (err)
443 			return err;
444 		fdt_set_version(buf, 17);
445 		fdt_set_size_dt_struct(buf, struct_size);
446 		fdt_set_totalsize(buf, bufsize);
447 		return 0;
448 	}
449 
450 	/* Need to reorder */
451 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
452 		+ struct_size + fdt_size_dt_strings(fdt);
453 
454 	if (bufsize < newsize)
455 		return -FDT_ERR_NOSPACE;
456 
457 	/* First attempt to build converted tree at beginning of buffer */
458 	tmp = buf;
459 	/* But if that overlaps with the old tree... */
460 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
461 		/* Try right after the old tree instead */
462 		tmp = (char *)(uintptr_t)fdtend;
463 		if ((tmp + newsize) > ((char *)buf + bufsize))
464 			return -FDT_ERR_NOSPACE;
465 	}
466 
467 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
468 	memmove(buf, tmp, newsize);
469 
470 	fdt_set_magic(buf, FDT_MAGIC);
471 	fdt_set_totalsize(buf, bufsize);
472 	fdt_set_version(buf, 17);
473 	fdt_set_last_comp_version(buf, 16);
474 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
475 
476 	return 0;
477 }
478 
fdt_pack(void * fdt)479 int fdt_pack(void *fdt)
480 {
481 	int mem_rsv_size;
482 
483 	FDT_RW_CHECK_HEADER(fdt);
484 
485 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
486 		* sizeof(struct fdt_reserve_entry);
487 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
488 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
489 
490 	return 0;
491 }
492