xref: /openbmc/linux/scripts/dtc/libfdt/fdt_ro.c (revision b830f94f)
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 static int fdt_nodename_eq_(const void *fdt, int offset,
14 			    const char *s, int len)
15 {
16 	int olen;
17 	const char *p = fdt_get_name(fdt, offset, &olen);
18 
19 	if (!p || olen < len)
20 		/* short match */
21 		return 0;
22 
23 	if (memcmp(p, s, len) != 0)
24 		return 0;
25 
26 	if (p[len] == '\0')
27 		return 1;
28 	else if (!memchr(s, '@', len) && (p[len] == '@'))
29 		return 1;
30 	else
31 		return 0;
32 }
33 
34 const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
35 {
36 	uint32_t absoffset = stroffset + fdt_off_dt_strings(fdt);
37 	size_t len;
38 	int err;
39 	const char *s, *n;
40 
41 	err = fdt_ro_probe_(fdt);
42 	if (err != 0)
43 		goto fail;
44 
45 	err = -FDT_ERR_BADOFFSET;
46 	if (absoffset >= fdt_totalsize(fdt))
47 		goto fail;
48 	len = fdt_totalsize(fdt) - absoffset;
49 
50 	if (fdt_magic(fdt) == FDT_MAGIC) {
51 		if (stroffset < 0)
52 			goto fail;
53 		if (fdt_version(fdt) >= 17) {
54 			if (stroffset >= fdt_size_dt_strings(fdt))
55 				goto fail;
56 			if ((fdt_size_dt_strings(fdt) - stroffset) < len)
57 				len = fdt_size_dt_strings(fdt) - stroffset;
58 		}
59 	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
60 		if ((stroffset >= 0)
61 		    || (stroffset < -fdt_size_dt_strings(fdt)))
62 			goto fail;
63 		if ((-stroffset) < len)
64 			len = -stroffset;
65 	} else {
66 		err = -FDT_ERR_INTERNAL;
67 		goto fail;
68 	}
69 
70 	s = (const char *)fdt + absoffset;
71 	n = memchr(s, '\0', len);
72 	if (!n) {
73 		/* missing terminating NULL */
74 		err = -FDT_ERR_TRUNCATED;
75 		goto fail;
76 	}
77 
78 	if (lenp)
79 		*lenp = n - s;
80 	return s;
81 
82 fail:
83 	if (lenp)
84 		*lenp = err;
85 	return NULL;
86 }
87 
88 const char *fdt_string(const void *fdt, int stroffset)
89 {
90 	return fdt_get_string(fdt, stroffset, NULL);
91 }
92 
93 static int fdt_string_eq_(const void *fdt, int stroffset,
94 			  const char *s, int len)
95 {
96 	int slen;
97 	const char *p = fdt_get_string(fdt, stroffset, &slen);
98 
99 	return p && (slen == len) && (memcmp(p, s, len) == 0);
100 }
101 
102 int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
103 {
104 	uint32_t max = 0;
105 	int offset = -1;
106 
107 	while (true) {
108 		uint32_t value;
109 
110 		offset = fdt_next_node(fdt, offset, NULL);
111 		if (offset < 0) {
112 			if (offset == -FDT_ERR_NOTFOUND)
113 				break;
114 
115 			return offset;
116 		}
117 
118 		value = fdt_get_phandle(fdt, offset);
119 
120 		if (value > max)
121 			max = value;
122 	}
123 
124 	if (phandle)
125 		*phandle = max;
126 
127 	return 0;
128 }
129 
130 int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
131 {
132 	uint32_t max;
133 	int err;
134 
135 	err = fdt_find_max_phandle(fdt, &max);
136 	if (err < 0)
137 		return err;
138 
139 	if (max == FDT_MAX_PHANDLE)
140 		return -FDT_ERR_NOPHANDLES;
141 
142 	if (phandle)
143 		*phandle = max + 1;
144 
145 	return 0;
146 }
147 
148 static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
149 {
150 	int offset = n * sizeof(struct fdt_reserve_entry);
151 	int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
152 
153 	if (absoffset < fdt_off_mem_rsvmap(fdt))
154 		return NULL;
155 	if (absoffset > fdt_totalsize(fdt) - sizeof(struct fdt_reserve_entry))
156 		return NULL;
157 	return fdt_mem_rsv_(fdt, n);
158 }
159 
160 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
161 {
162 	const struct fdt_reserve_entry *re;
163 
164 	FDT_RO_PROBE(fdt);
165 	re = fdt_mem_rsv(fdt, n);
166 	if (!re)
167 		return -FDT_ERR_BADOFFSET;
168 
169 	*address = fdt64_ld(&re->address);
170 	*size = fdt64_ld(&re->size);
171 	return 0;
172 }
173 
174 int fdt_num_mem_rsv(const void *fdt)
175 {
176 	int i;
177 	const struct fdt_reserve_entry *re;
178 
179 	for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
180 		if (fdt64_ld(&re->size) == 0)
181 			return i;
182 	}
183 	return -FDT_ERR_TRUNCATED;
184 }
185 
186 static int nextprop_(const void *fdt, int offset)
187 {
188 	uint32_t tag;
189 	int nextoffset;
190 
191 	do {
192 		tag = fdt_next_tag(fdt, offset, &nextoffset);
193 
194 		switch (tag) {
195 		case FDT_END:
196 			if (nextoffset >= 0)
197 				return -FDT_ERR_BADSTRUCTURE;
198 			else
199 				return nextoffset;
200 
201 		case FDT_PROP:
202 			return offset;
203 		}
204 		offset = nextoffset;
205 	} while (tag == FDT_NOP);
206 
207 	return -FDT_ERR_NOTFOUND;
208 }
209 
210 int fdt_subnode_offset_namelen(const void *fdt, int offset,
211 			       const char *name, int namelen)
212 {
213 	int depth;
214 
215 	FDT_RO_PROBE(fdt);
216 
217 	for (depth = 0;
218 	     (offset >= 0) && (depth >= 0);
219 	     offset = fdt_next_node(fdt, offset, &depth))
220 		if ((depth == 1)
221 		    && fdt_nodename_eq_(fdt, offset, name, namelen))
222 			return offset;
223 
224 	if (depth < 0)
225 		return -FDT_ERR_NOTFOUND;
226 	return offset; /* error */
227 }
228 
229 int fdt_subnode_offset(const void *fdt, int parentoffset,
230 		       const char *name)
231 {
232 	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
233 }
234 
235 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
236 {
237 	const char *end = path + namelen;
238 	const char *p = path;
239 	int offset = 0;
240 
241 	FDT_RO_PROBE(fdt);
242 
243 	/* see if we have an alias */
244 	if (*path != '/') {
245 		const char *q = memchr(path, '/', end - p);
246 
247 		if (!q)
248 			q = end;
249 
250 		p = fdt_get_alias_namelen(fdt, p, q - p);
251 		if (!p)
252 			return -FDT_ERR_BADPATH;
253 		offset = fdt_path_offset(fdt, p);
254 
255 		p = q;
256 	}
257 
258 	while (p < end) {
259 		const char *q;
260 
261 		while (*p == '/') {
262 			p++;
263 			if (p == end)
264 				return offset;
265 		}
266 		q = memchr(p, '/', end - p);
267 		if (! q)
268 			q = end;
269 
270 		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
271 		if (offset < 0)
272 			return offset;
273 
274 		p = q;
275 	}
276 
277 	return offset;
278 }
279 
280 int fdt_path_offset(const void *fdt, const char *path)
281 {
282 	return fdt_path_offset_namelen(fdt, path, strlen(path));
283 }
284 
285 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
286 {
287 	const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
288 	const char *nameptr;
289 	int err;
290 
291 	if (((err = fdt_ro_probe_(fdt)) != 0)
292 	    || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
293 			goto fail;
294 
295 	nameptr = nh->name;
296 
297 	if (fdt_version(fdt) < 0x10) {
298 		/*
299 		 * For old FDT versions, match the naming conventions of V16:
300 		 * give only the leaf name (after all /). The actual tree
301 		 * contents are loosely checked.
302 		 */
303 		const char *leaf;
304 		leaf = strrchr(nameptr, '/');
305 		if (leaf == NULL) {
306 			err = -FDT_ERR_BADSTRUCTURE;
307 			goto fail;
308 		}
309 		nameptr = leaf+1;
310 	}
311 
312 	if (len)
313 		*len = strlen(nameptr);
314 
315 	return nameptr;
316 
317  fail:
318 	if (len)
319 		*len = err;
320 	return NULL;
321 }
322 
323 int fdt_first_property_offset(const void *fdt, int nodeoffset)
324 {
325 	int offset;
326 
327 	if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
328 		return offset;
329 
330 	return nextprop_(fdt, offset);
331 }
332 
333 int fdt_next_property_offset(const void *fdt, int offset)
334 {
335 	if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
336 		return offset;
337 
338 	return nextprop_(fdt, offset);
339 }
340 
341 static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
342 						              int offset,
343 						              int *lenp)
344 {
345 	int err;
346 	const struct fdt_property *prop;
347 
348 	if ((err = fdt_check_prop_offset_(fdt, offset)) < 0) {
349 		if (lenp)
350 			*lenp = err;
351 		return NULL;
352 	}
353 
354 	prop = fdt_offset_ptr_(fdt, offset);
355 
356 	if (lenp)
357 		*lenp = fdt32_ld(&prop->len);
358 
359 	return prop;
360 }
361 
362 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
363 						      int offset,
364 						      int *lenp)
365 {
366 	/* Prior to version 16, properties may need realignment
367 	 * and this API does not work. fdt_getprop_*() will, however. */
368 
369 	if (fdt_version(fdt) < 0x10) {
370 		if (lenp)
371 			*lenp = -FDT_ERR_BADVERSION;
372 		return NULL;
373 	}
374 
375 	return fdt_get_property_by_offset_(fdt, offset, lenp);
376 }
377 
378 static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
379 						            int offset,
380 						            const char *name,
381 						            int namelen,
382 							    int *lenp,
383 							    int *poffset)
384 {
385 	for (offset = fdt_first_property_offset(fdt, offset);
386 	     (offset >= 0);
387 	     (offset = fdt_next_property_offset(fdt, offset))) {
388 		const struct fdt_property *prop;
389 
390 		if (!(prop = fdt_get_property_by_offset_(fdt, offset, lenp))) {
391 			offset = -FDT_ERR_INTERNAL;
392 			break;
393 		}
394 		if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
395 				   name, namelen)) {
396 			if (poffset)
397 				*poffset = offset;
398 			return prop;
399 		}
400 	}
401 
402 	if (lenp)
403 		*lenp = offset;
404 	return NULL;
405 }
406 
407 
408 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
409 						    int offset,
410 						    const char *name,
411 						    int namelen, int *lenp)
412 {
413 	/* Prior to version 16, properties may need realignment
414 	 * and this API does not work. fdt_getprop_*() will, however. */
415 	if (fdt_version(fdt) < 0x10) {
416 		if (lenp)
417 			*lenp = -FDT_ERR_BADVERSION;
418 		return NULL;
419 	}
420 
421 	return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
422 					 NULL);
423 }
424 
425 
426 const struct fdt_property *fdt_get_property(const void *fdt,
427 					    int nodeoffset,
428 					    const char *name, int *lenp)
429 {
430 	return fdt_get_property_namelen(fdt, nodeoffset, name,
431 					strlen(name), lenp);
432 }
433 
434 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
435 				const char *name, int namelen, int *lenp)
436 {
437 	int poffset;
438 	const struct fdt_property *prop;
439 
440 	prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
441 					 &poffset);
442 	if (!prop)
443 		return NULL;
444 
445 	/* Handle realignment */
446 	if (fdt_version(fdt) < 0x10 && (poffset + sizeof(*prop)) % 8 &&
447 	    fdt32_ld(&prop->len) >= 8)
448 		return prop->data + 4;
449 	return prop->data;
450 }
451 
452 const void *fdt_getprop_by_offset(const void *fdt, int offset,
453 				  const char **namep, int *lenp)
454 {
455 	const struct fdt_property *prop;
456 
457 	prop = fdt_get_property_by_offset_(fdt, offset, lenp);
458 	if (!prop)
459 		return NULL;
460 	if (namep) {
461 		const char *name;
462 		int namelen;
463 		name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
464 				      &namelen);
465 		if (!name) {
466 			if (lenp)
467 				*lenp = namelen;
468 			return NULL;
469 		}
470 		*namep = name;
471 	}
472 
473 	/* Handle realignment */
474 	if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
475 	    fdt32_ld(&prop->len) >= 8)
476 		return prop->data + 4;
477 	return prop->data;
478 }
479 
480 const void *fdt_getprop(const void *fdt, int nodeoffset,
481 			const char *name, int *lenp)
482 {
483 	return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
484 }
485 
486 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
487 {
488 	const fdt32_t *php;
489 	int len;
490 
491 	/* FIXME: This is a bit sub-optimal, since we potentially scan
492 	 * over all the properties twice. */
493 	php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
494 	if (!php || (len != sizeof(*php))) {
495 		php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
496 		if (!php || (len != sizeof(*php)))
497 			return 0;
498 	}
499 
500 	return fdt32_ld(php);
501 }
502 
503 const char *fdt_get_alias_namelen(const void *fdt,
504 				  const char *name, int namelen)
505 {
506 	int aliasoffset;
507 
508 	aliasoffset = fdt_path_offset(fdt, "/aliases");
509 	if (aliasoffset < 0)
510 		return NULL;
511 
512 	return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
513 }
514 
515 const char *fdt_get_alias(const void *fdt, const char *name)
516 {
517 	return fdt_get_alias_namelen(fdt, name, strlen(name));
518 }
519 
520 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
521 {
522 	int pdepth = 0, p = 0;
523 	int offset, depth, namelen;
524 	const char *name;
525 
526 	FDT_RO_PROBE(fdt);
527 
528 	if (buflen < 2)
529 		return -FDT_ERR_NOSPACE;
530 
531 	for (offset = 0, depth = 0;
532 	     (offset >= 0) && (offset <= nodeoffset);
533 	     offset = fdt_next_node(fdt, offset, &depth)) {
534 		while (pdepth > depth) {
535 			do {
536 				p--;
537 			} while (buf[p-1] != '/');
538 			pdepth--;
539 		}
540 
541 		if (pdepth >= depth) {
542 			name = fdt_get_name(fdt, offset, &namelen);
543 			if (!name)
544 				return namelen;
545 			if ((p + namelen + 1) <= buflen) {
546 				memcpy(buf + p, name, namelen);
547 				p += namelen;
548 				buf[p++] = '/';
549 				pdepth++;
550 			}
551 		}
552 
553 		if (offset == nodeoffset) {
554 			if (pdepth < (depth + 1))
555 				return -FDT_ERR_NOSPACE;
556 
557 			if (p > 1) /* special case so that root path is "/", not "" */
558 				p--;
559 			buf[p] = '\0';
560 			return 0;
561 		}
562 	}
563 
564 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
565 		return -FDT_ERR_BADOFFSET;
566 	else if (offset == -FDT_ERR_BADOFFSET)
567 		return -FDT_ERR_BADSTRUCTURE;
568 
569 	return offset; /* error from fdt_next_node() */
570 }
571 
572 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
573 				 int supernodedepth, int *nodedepth)
574 {
575 	int offset, depth;
576 	int supernodeoffset = -FDT_ERR_INTERNAL;
577 
578 	FDT_RO_PROBE(fdt);
579 
580 	if (supernodedepth < 0)
581 		return -FDT_ERR_NOTFOUND;
582 
583 	for (offset = 0, depth = 0;
584 	     (offset >= 0) && (offset <= nodeoffset);
585 	     offset = fdt_next_node(fdt, offset, &depth)) {
586 		if (depth == supernodedepth)
587 			supernodeoffset = offset;
588 
589 		if (offset == nodeoffset) {
590 			if (nodedepth)
591 				*nodedepth = depth;
592 
593 			if (supernodedepth > depth)
594 				return -FDT_ERR_NOTFOUND;
595 			else
596 				return supernodeoffset;
597 		}
598 	}
599 
600 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
601 		return -FDT_ERR_BADOFFSET;
602 	else if (offset == -FDT_ERR_BADOFFSET)
603 		return -FDT_ERR_BADSTRUCTURE;
604 
605 	return offset; /* error from fdt_next_node() */
606 }
607 
608 int fdt_node_depth(const void *fdt, int nodeoffset)
609 {
610 	int nodedepth;
611 	int err;
612 
613 	err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
614 	if (err)
615 		return (err < 0) ? err : -FDT_ERR_INTERNAL;
616 	return nodedepth;
617 }
618 
619 int fdt_parent_offset(const void *fdt, int nodeoffset)
620 {
621 	int nodedepth = fdt_node_depth(fdt, nodeoffset);
622 
623 	if (nodedepth < 0)
624 		return nodedepth;
625 	return fdt_supernode_atdepth_offset(fdt, nodeoffset,
626 					    nodedepth - 1, NULL);
627 }
628 
629 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
630 				  const char *propname,
631 				  const void *propval, int proplen)
632 {
633 	int offset;
634 	const void *val;
635 	int len;
636 
637 	FDT_RO_PROBE(fdt);
638 
639 	/* FIXME: The algorithm here is pretty horrible: we scan each
640 	 * property of a node in fdt_getprop(), then if that didn't
641 	 * find what we want, we scan over them again making our way
642 	 * to the next node.  Still it's the easiest to implement
643 	 * approach; performance can come later. */
644 	for (offset = fdt_next_node(fdt, startoffset, NULL);
645 	     offset >= 0;
646 	     offset = fdt_next_node(fdt, offset, NULL)) {
647 		val = fdt_getprop(fdt, offset, propname, &len);
648 		if (val && (len == proplen)
649 		    && (memcmp(val, propval, len) == 0))
650 			return offset;
651 	}
652 
653 	return offset; /* error from fdt_next_node() */
654 }
655 
656 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
657 {
658 	int offset;
659 
660 	if ((phandle == 0) || (phandle == -1))
661 		return -FDT_ERR_BADPHANDLE;
662 
663 	FDT_RO_PROBE(fdt);
664 
665 	/* FIXME: The algorithm here is pretty horrible: we
666 	 * potentially scan each property of a node in
667 	 * fdt_get_phandle(), then if that didn't find what
668 	 * we want, we scan over them again making our way to the next
669 	 * node.  Still it's the easiest to implement approach;
670 	 * performance can come later. */
671 	for (offset = fdt_next_node(fdt, -1, NULL);
672 	     offset >= 0;
673 	     offset = fdt_next_node(fdt, offset, NULL)) {
674 		if (fdt_get_phandle(fdt, offset) == phandle)
675 			return offset;
676 	}
677 
678 	return offset; /* error from fdt_next_node() */
679 }
680 
681 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
682 {
683 	int len = strlen(str);
684 	const char *p;
685 
686 	while (listlen >= len) {
687 		if (memcmp(str, strlist, len+1) == 0)
688 			return 1;
689 		p = memchr(strlist, '\0', listlen);
690 		if (!p)
691 			return 0; /* malformed strlist.. */
692 		listlen -= (p-strlist) + 1;
693 		strlist = p + 1;
694 	}
695 	return 0;
696 }
697 
698 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
699 {
700 	const char *list, *end;
701 	int length, count = 0;
702 
703 	list = fdt_getprop(fdt, nodeoffset, property, &length);
704 	if (!list)
705 		return length;
706 
707 	end = list + length;
708 
709 	while (list < end) {
710 		length = strnlen(list, end - list) + 1;
711 
712 		/* Abort if the last string isn't properly NUL-terminated. */
713 		if (list + length > end)
714 			return -FDT_ERR_BADVALUE;
715 
716 		list += length;
717 		count++;
718 	}
719 
720 	return count;
721 }
722 
723 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
724 			  const char *string)
725 {
726 	int length, len, idx = 0;
727 	const char *list, *end;
728 
729 	list = fdt_getprop(fdt, nodeoffset, property, &length);
730 	if (!list)
731 		return length;
732 
733 	len = strlen(string) + 1;
734 	end = list + length;
735 
736 	while (list < end) {
737 		length = strnlen(list, end - list) + 1;
738 
739 		/* Abort if the last string isn't properly NUL-terminated. */
740 		if (list + length > end)
741 			return -FDT_ERR_BADVALUE;
742 
743 		if (length == len && memcmp(list, string, length) == 0)
744 			return idx;
745 
746 		list += length;
747 		idx++;
748 	}
749 
750 	return -FDT_ERR_NOTFOUND;
751 }
752 
753 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
754 			       const char *property, int idx,
755 			       int *lenp)
756 {
757 	const char *list, *end;
758 	int length;
759 
760 	list = fdt_getprop(fdt, nodeoffset, property, &length);
761 	if (!list) {
762 		if (lenp)
763 			*lenp = length;
764 
765 		return NULL;
766 	}
767 
768 	end = list + length;
769 
770 	while (list < end) {
771 		length = strnlen(list, end - list) + 1;
772 
773 		/* Abort if the last string isn't properly NUL-terminated. */
774 		if (list + length > end) {
775 			if (lenp)
776 				*lenp = -FDT_ERR_BADVALUE;
777 
778 			return NULL;
779 		}
780 
781 		if (idx == 0) {
782 			if (lenp)
783 				*lenp = length - 1;
784 
785 			return list;
786 		}
787 
788 		list += length;
789 		idx--;
790 	}
791 
792 	if (lenp)
793 		*lenp = -FDT_ERR_NOTFOUND;
794 
795 	return NULL;
796 }
797 
798 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
799 			      const char *compatible)
800 {
801 	const void *prop;
802 	int len;
803 
804 	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
805 	if (!prop)
806 		return len;
807 
808 	return !fdt_stringlist_contains(prop, len, compatible);
809 }
810 
811 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
812 				  const char *compatible)
813 {
814 	int offset, err;
815 
816 	FDT_RO_PROBE(fdt);
817 
818 	/* FIXME: The algorithm here is pretty horrible: we scan each
819 	 * property of a node in fdt_node_check_compatible(), then if
820 	 * that didn't find what we want, we scan over them again
821 	 * making our way to the next node.  Still it's the easiest to
822 	 * implement approach; performance can come later. */
823 	for (offset = fdt_next_node(fdt, startoffset, NULL);
824 	     offset >= 0;
825 	     offset = fdt_next_node(fdt, offset, NULL)) {
826 		err = fdt_node_check_compatible(fdt, offset, compatible);
827 		if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
828 			return err;
829 		else if (err == 0)
830 			return offset;
831 	}
832 
833 	return offset; /* error from fdt_next_node() */
834 }
835 
836 int fdt_check_full(const void *fdt, size_t bufsize)
837 {
838 	int err;
839 	int num_memrsv;
840 	int offset, nextoffset = 0;
841 	uint32_t tag;
842 	unsigned depth = 0;
843 	const void *prop;
844 	const char *propname;
845 
846 	if (bufsize < FDT_V1_SIZE)
847 		return -FDT_ERR_TRUNCATED;
848 	err = fdt_check_header(fdt);
849 	if (err != 0)
850 		return err;
851 	if (bufsize < fdt_totalsize(fdt))
852 		return -FDT_ERR_TRUNCATED;
853 
854 	num_memrsv = fdt_num_mem_rsv(fdt);
855 	if (num_memrsv < 0)
856 		return num_memrsv;
857 
858 	while (1) {
859 		offset = nextoffset;
860 		tag = fdt_next_tag(fdt, offset, &nextoffset);
861 
862 		if (nextoffset < 0)
863 			return nextoffset;
864 
865 		switch (tag) {
866 		case FDT_NOP:
867 			break;
868 
869 		case FDT_END:
870 			if (depth != 0)
871 				return -FDT_ERR_BADSTRUCTURE;
872 			return 0;
873 
874 		case FDT_BEGIN_NODE:
875 			depth++;
876 			if (depth > INT_MAX)
877 				return -FDT_ERR_BADSTRUCTURE;
878 			break;
879 
880 		case FDT_END_NODE:
881 			if (depth == 0)
882 				return -FDT_ERR_BADSTRUCTURE;
883 			depth--;
884 			break;
885 
886 		case FDT_PROP:
887 			prop = fdt_getprop_by_offset(fdt, offset, &propname,
888 						     &err);
889 			if (!prop)
890 				return err;
891 			break;
892 
893 		default:
894 			return -FDT_ERR_INTERNAL;
895 		}
896 	}
897 }
898