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 
fdt_nodename_eq_(const void * fdt,int offset,const char * s,int len)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 || (fdt_chk_extra() && 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 
fdt_get_string(const void * fdt,int stroffset,int * lenp)34 const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
35 {
36 	int32_t totalsize;
37 	uint32_t absoffset;
38 	size_t len;
39 	int err;
40 	const char *s, *n;
41 
42 	if (!fdt_chk_extra()) {
43 		s = (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
44 
45 		if (lenp)
46 			*lenp = strlen(s);
47 		return s;
48 	}
49 	totalsize = fdt_ro_probe_(fdt);
50 	err = totalsize;
51 	if (totalsize < 0)
52 		goto fail;
53 
54 	err = -FDT_ERR_BADOFFSET;
55 	absoffset = stroffset + fdt_off_dt_strings(fdt);
56 	if (absoffset >= (unsigned)totalsize)
57 		goto fail;
58 	len = totalsize - absoffset;
59 
60 	if (fdt_magic(fdt) == FDT_MAGIC) {
61 		if (stroffset < 0)
62 			goto fail;
63 		if (!fdt_chk_version() || fdt_version(fdt) >= 17) {
64 			if ((unsigned)stroffset >= fdt_size_dt_strings(fdt))
65 				goto fail;
66 			if ((fdt_size_dt_strings(fdt) - stroffset) < len)
67 				len = fdt_size_dt_strings(fdt) - stroffset;
68 		}
69 	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
70 		unsigned int sw_stroffset = -stroffset;
71 
72 		if ((stroffset >= 0) ||
73 		    (sw_stroffset > fdt_size_dt_strings(fdt)))
74 			goto fail;
75 		if ((sw_stroffset) < len)
76 			len = sw_stroffset;
77 	} else {
78 		err = -FDT_ERR_INTERNAL;
79 		goto fail;
80 	}
81 
82 	s = (const char *)fdt + absoffset;
83 	n = memchr(s, '\0', len);
84 	if (!n) {
85 		/* missing terminating NULL */
86 		err = -FDT_ERR_TRUNCATED;
87 		goto fail;
88 	}
89 
90 	if (lenp)
91 		*lenp = n - s;
92 	return s;
93 
94 fail:
95 	if (lenp)
96 		*lenp = err;
97 	return NULL;
98 }
99 
fdt_string(const void * fdt,int stroffset)100 const char *fdt_string(const void *fdt, int stroffset)
101 {
102 	return fdt_get_string(fdt, stroffset, NULL);
103 }
104 
fdt_string_eq_(const void * fdt,int stroffset,const char * s,int len)105 static int fdt_string_eq_(const void *fdt, int stroffset,
106 			  const char *s, int len)
107 {
108 	int slen;
109 	const char *p = fdt_get_string(fdt, stroffset, &slen);
110 
111 	return p && (slen == len) && (memcmp(p, s, len) == 0);
112 }
113 
fdt_find_max_phandle(const void * fdt,uint32_t * phandle)114 int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
115 {
116 	uint32_t max = 0;
117 	int offset = -1;
118 
119 	while (true) {
120 		uint32_t value;
121 
122 		offset = fdt_next_node(fdt, offset, NULL);
123 		if (offset < 0) {
124 			if (offset == -FDT_ERR_NOTFOUND)
125 				break;
126 
127 			return offset;
128 		}
129 
130 		value = fdt_get_phandle(fdt, offset);
131 
132 		if (value > max)
133 			max = value;
134 	}
135 
136 	if (phandle)
137 		*phandle = max;
138 
139 	return 0;
140 }
141 
fdt_generate_phandle(const void * fdt,uint32_t * phandle)142 int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
143 {
144 	uint32_t max;
145 	int err;
146 
147 	err = fdt_find_max_phandle(fdt, &max);
148 	if (err < 0)
149 		return err;
150 
151 	if (max == FDT_MAX_PHANDLE)
152 		return -FDT_ERR_NOPHANDLES;
153 
154 	if (phandle)
155 		*phandle = max + 1;
156 
157 	return 0;
158 }
159 
fdt_mem_rsv(const void * fdt,int n)160 static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
161 {
162 	unsigned int offset = n * sizeof(struct fdt_reserve_entry);
163 	unsigned int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
164 
165 	if (fdt_chk_extra()) {
166 		if (absoffset < fdt_off_mem_rsvmap(fdt))
167 			return NULL;
168 		if (absoffset > fdt_totalsize(fdt) -
169 		    sizeof(struct fdt_reserve_entry))
170 			return NULL;
171 	}
172 	return fdt_mem_rsv_(fdt, n);
173 }
174 
fdt_get_mem_rsv(const void * fdt,int n,uint64_t * address,uint64_t * size)175 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
176 {
177 	const struct fdt_reserve_entry *re;
178 
179 	FDT_RO_PROBE(fdt);
180 	re = fdt_mem_rsv(fdt, n);
181 	if (fdt_chk_extra() && !re)
182 		return -FDT_ERR_BADOFFSET;
183 
184 	*address = fdt64_to_cpu(re->address);
185 	*size = fdt64_to_cpu(re->size);
186 	return 0;
187 }
188 
fdt_num_mem_rsv(const void * fdt)189 int fdt_num_mem_rsv(const void *fdt)
190 {
191 	int i;
192 	const struct fdt_reserve_entry *re;
193 
194 	for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
195 		if (fdt64_to_cpu(re->size) == 0)
196 			return i;
197 	}
198 	return -FDT_ERR_TRUNCATED;
199 }
200 
nextprop_(const void * fdt,int offset)201 static int nextprop_(const void *fdt, int offset)
202 {
203 	uint32_t tag;
204 	int nextoffset;
205 
206 	do {
207 		tag = fdt_next_tag(fdt, offset, &nextoffset);
208 
209 		switch (tag) {
210 		case FDT_END:
211 			if (nextoffset >= 0)
212 				return -FDT_ERR_BADSTRUCTURE;
213 			else
214 				return nextoffset;
215 
216 		case FDT_PROP:
217 			return offset;
218 		}
219 		offset = nextoffset;
220 	} while (tag == FDT_NOP);
221 
222 	return -FDT_ERR_NOTFOUND;
223 }
224 
fdt_subnode_offset_namelen(const void * fdt,int offset,const char * name,int namelen)225 int fdt_subnode_offset_namelen(const void *fdt, int offset,
226 			       const char *name, int namelen)
227 {
228 	int depth;
229 
230 	FDT_RO_PROBE(fdt);
231 
232 	for (depth = 0;
233 	     (offset >= 0) && (depth >= 0);
234 	     offset = fdt_next_node(fdt, offset, &depth))
235 		if ((depth == 1)
236 		    && fdt_nodename_eq_(fdt, offset, name, namelen))
237 			return offset;
238 
239 	if (depth < 0)
240 		return -FDT_ERR_NOTFOUND;
241 	return offset; /* error */
242 }
243 
fdt_subnode_offset(const void * fdt,int parentoffset,const char * name)244 int fdt_subnode_offset(const void *fdt, int parentoffset,
245 		       const char *name)
246 {
247 	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
248 }
249 
fdt_path_offset_namelen(const void * fdt,const char * path,int namelen)250 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
251 {
252 	const char *end = path + namelen;
253 	const char *p = path;
254 	int offset = 0;
255 
256 	FDT_RO_PROBE(fdt);
257 
258 	/* see if we have an alias */
259 	if (*path != '/') {
260 		const char *q = memchr(path, '/', end - p);
261 
262 		if (!q)
263 			q = end;
264 
265 		p = fdt_get_alias_namelen(fdt, p, q - p);
266 		if (!p)
267 			return -FDT_ERR_BADPATH;
268 		offset = fdt_path_offset(fdt, p);
269 
270 		p = q;
271 	}
272 
273 	while (p < end) {
274 		const char *q;
275 
276 		while (*p == '/') {
277 			p++;
278 			if (p == end)
279 				return offset;
280 		}
281 		q = memchr(p, '/', end - p);
282 		if (! q)
283 			q = end;
284 
285 		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
286 		if (offset < 0)
287 			return offset;
288 
289 		p = q;
290 	}
291 
292 	return offset;
293 }
294 
fdt_path_offset(const void * fdt,const char * path)295 int fdt_path_offset(const void *fdt, const char *path)
296 {
297 	return fdt_path_offset_namelen(fdt, path, strlen(path));
298 }
299 
fdt_get_name(const void * fdt,int nodeoffset,int * len)300 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
301 {
302 	const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
303 	const char *nameptr;
304 	int err;
305 
306 	if (fdt_chk_extra() &&
307 	    (((err = fdt_ro_probe_(fdt)) < 0)
308 	     || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0)))
309 		goto fail;
310 
311 	nameptr = nh->name;
312 
313 	if (fdt_chk_version() && fdt_version(fdt) < 0x10) {
314 		/*
315 		 * For old FDT versions, match the naming conventions of V16:
316 		 * give only the leaf name (after all /). The actual tree
317 		 * contents are loosely checked.
318 		 */
319 		const char *leaf;
320 		leaf = strrchr(nameptr, '/');
321 		if (leaf == NULL) {
322 			err = -FDT_ERR_BADSTRUCTURE;
323 			goto fail;
324 		}
325 		nameptr = leaf+1;
326 	}
327 
328 	if (len)
329 		*len = strlen(nameptr);
330 
331 	return nameptr;
332 
333  fail:
334 	if (len)
335 		*len = err;
336 	return NULL;
337 }
338 
fdt_first_property_offset(const void * fdt,int nodeoffset)339 int fdt_first_property_offset(const void *fdt, int nodeoffset)
340 {
341 	int offset;
342 
343 	if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
344 		return offset;
345 
346 	return nextprop_(fdt, offset);
347 }
348 
fdt_next_property_offset(const void * fdt,int offset)349 int fdt_next_property_offset(const void *fdt, int offset)
350 {
351 	if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
352 		return offset;
353 
354 	return nextprop_(fdt, offset);
355 }
356 
fdt_get_property_by_offset_(const void * fdt,int offset,int * lenp)357 static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
358 						              int offset,
359 						              int *lenp)
360 {
361 	int err;
362 	const struct fdt_property *prop;
363 
364 	if (fdt_chk_basic() && (err = fdt_check_prop_offset_(fdt, offset)) < 0) {
365 		if (lenp)
366 			*lenp = err;
367 		return NULL;
368 	}
369 
370 	prop = fdt_offset_ptr_(fdt, offset);
371 
372 	if (lenp)
373 		*lenp = fdt32_to_cpu(prop->len);
374 
375 	return prop;
376 }
377 
fdt_get_property_by_offset(const void * fdt,int offset,int * lenp)378 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
379 						      int offset,
380 						      int *lenp)
381 {
382 	/* Prior to version 16, properties may need realignment
383 	 * and this API does not work. fdt_getprop_*() will, however. */
384 
385 	if (fdt_chk_version() && fdt_version(fdt) < 0x10) {
386 		if (lenp)
387 			*lenp = -FDT_ERR_BADVERSION;
388 		return NULL;
389 	}
390 
391 	return fdt_get_property_by_offset_(fdt, offset, lenp);
392 }
393 
fdt_get_property_namelen_(const void * fdt,int offset,const char * name,int namelen,int * lenp,int * poffset)394 static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
395 						            int offset,
396 						            const char *name,
397 						            int namelen,
398 							    int *lenp,
399 							    int *poffset)
400 {
401 	for (offset = fdt_first_property_offset(fdt, offset);
402 	     (offset >= 0);
403 	     (offset = fdt_next_property_offset(fdt, offset))) {
404 		const struct fdt_property *prop;
405 
406 		prop = fdt_get_property_by_offset_(fdt, offset, lenp);
407 		if (fdt_chk_extra() && !prop) {
408 			offset = -FDT_ERR_INTERNAL;
409 			break;
410 		}
411 		if (fdt_string_eq_(fdt, fdt32_to_cpu(prop->nameoff),
412 				   name, namelen)) {
413 			if (poffset)
414 				*poffset = offset;
415 			return prop;
416 		}
417 	}
418 
419 	if (lenp)
420 		*lenp = offset;
421 	return NULL;
422 }
423 
fdt_get_property_namelen(const void * fdt,int offset,const char * name,int namelen,int * lenp)424 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
425 						    int offset,
426 						    const char *name,
427 						    int namelen, int *lenp)
428 {
429 	/* Prior to version 16, properties may need realignment
430 	 * and this API does not work. fdt_getprop_*() will, however. */
431 	if (fdt_chk_version() && fdt_version(fdt) < 0x10) {
432 		if (lenp)
433 			*lenp = -FDT_ERR_BADVERSION;
434 		return NULL;
435 	}
436 
437 	return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
438 					 NULL);
439 }
440 
fdt_get_property(const void * fdt,int nodeoffset,const char * name,int * lenp)441 const struct fdt_property *fdt_get_property(const void *fdt,
442 					    int nodeoffset,
443 					    const char *name, int *lenp)
444 {
445 	return fdt_get_property_namelen(fdt, nodeoffset, name,
446 					strlen(name), lenp);
447 }
448 
fdt_getprop_namelen(const void * fdt,int nodeoffset,const char * name,int namelen,int * lenp)449 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
450 				const char *name, int namelen, int *lenp)
451 {
452 	int poffset;
453 	const struct fdt_property *prop;
454 
455 	prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
456 					 &poffset);
457 	if (!prop)
458 		return NULL;
459 
460 	/* Handle realignment */
461 	if (fdt_chk_version() && fdt_version(fdt) < 0x10 &&
462 	    (poffset + sizeof(*prop)) % 8 && fdt32_to_cpu(prop->len) >= 8)
463 		return prop->data + 4;
464 	return prop->data;
465 }
466 
fdt_getprop_by_offset(const void * fdt,int offset,const char ** namep,int * lenp)467 const void *fdt_getprop_by_offset(const void *fdt, int offset,
468 				  const char **namep, int *lenp)
469 {
470 	const struct fdt_property *prop;
471 
472 	prop = fdt_get_property_by_offset_(fdt, offset, lenp);
473 	if (!prop)
474 		return NULL;
475 	if (namep) {
476 		const char *name;
477 		int namelen;
478 
479 		if (fdt_chk_extra()) {
480 			name = fdt_get_string(fdt, fdt32_to_cpu(prop->nameoff),
481 					      &namelen);
482 			if (!name) {
483 				if (lenp)
484 					*lenp = namelen;
485 				return NULL;
486 			}
487 			*namep = name;
488 		} else {
489 			*namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
490 		}
491 	}
492 
493 	/* Handle realignment */
494 	if (fdt_chk_version() && fdt_version(fdt) < 0x10 &&
495 	    (offset + sizeof(*prop)) % 8 && fdt32_to_cpu(prop->len) >= 8)
496 		return prop->data + 4;
497 	return prop->data;
498 }
499 
fdt_getprop(const void * fdt,int nodeoffset,const char * name,int * lenp)500 const void *fdt_getprop(const void *fdt, int nodeoffset,
501 			const char *name, int *lenp)
502 {
503 	return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
504 }
505 
fdt_get_phandle(const void * fdt,int nodeoffset)506 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
507 {
508 	const fdt32_t *php;
509 	int len;
510 
511 	/* FIXME: This is a bit sub-optimal, since we potentially scan
512 	 * over all the properties twice. */
513 	php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
514 	if (!php || (len != sizeof(*php))) {
515 		php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
516 		if (!php || (len != sizeof(*php)))
517 			return 0;
518 	}
519 
520 	return fdt32_to_cpu(*php);
521 }
522 
fdt_get_alias_namelen(const void * fdt,const char * name,int namelen)523 const char *fdt_get_alias_namelen(const void *fdt,
524 				  const char *name, int namelen)
525 {
526 	int aliasoffset;
527 
528 	aliasoffset = fdt_path_offset(fdt, "/aliases");
529 	if (aliasoffset < 0)
530 		return NULL;
531 
532 	return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
533 }
534 
fdt_get_alias(const void * fdt,const char * name)535 const char *fdt_get_alias(const void *fdt, const char *name)
536 {
537 	return fdt_get_alias_namelen(fdt, name, strlen(name));
538 }
539 
fdt_get_path(const void * fdt,int nodeoffset,char * buf,int buflen)540 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
541 {
542 	int pdepth = 0, p = 0;
543 	int offset, depth, namelen;
544 	const char *name;
545 
546 	FDT_RO_PROBE(fdt);
547 
548 	if (buflen < 2)
549 		return -FDT_ERR_NOSPACE;
550 
551 	for (offset = 0, depth = 0;
552 	     (offset >= 0) && (offset <= nodeoffset);
553 	     offset = fdt_next_node(fdt, offset, &depth)) {
554 		while (pdepth > depth) {
555 			do {
556 				p--;
557 			} while (buf[p-1] != '/');
558 			pdepth--;
559 		}
560 
561 		if (pdepth >= depth) {
562 			name = fdt_get_name(fdt, offset, &namelen);
563 			if (!name)
564 				return namelen;
565 			if ((p + namelen + 1) <= buflen) {
566 				memcpy(buf + p, name, namelen);
567 				p += namelen;
568 				buf[p++] = '/';
569 				pdepth++;
570 			}
571 		}
572 
573 		if (offset == nodeoffset) {
574 			if (pdepth < (depth + 1))
575 				return -FDT_ERR_NOSPACE;
576 
577 			if (p > 1) /* special case so that root path is "/", not "" */
578 				p--;
579 			buf[p] = '\0';
580 			return 0;
581 		}
582 	}
583 
584 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
585 		return -FDT_ERR_BADOFFSET;
586 	else if (offset == -FDT_ERR_BADOFFSET)
587 		return -FDT_ERR_BADSTRUCTURE;
588 
589 	return offset; /* error from fdt_next_node() */
590 }
591 
fdt_supernode_atdepth_offset(const void * fdt,int nodeoffset,int supernodedepth,int * nodedepth)592 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
593 				 int supernodedepth, int *nodedepth)
594 {
595 	int offset, depth;
596 	int supernodeoffset = -FDT_ERR_INTERNAL;
597 
598 	FDT_RO_PROBE(fdt);
599 
600 	if (supernodedepth < 0)
601 		return -FDT_ERR_NOTFOUND;
602 
603 	for (offset = 0, depth = 0;
604 	     (offset >= 0) && (offset <= nodeoffset);
605 	     offset = fdt_next_node(fdt, offset, &depth)) {
606 		if (depth == supernodedepth)
607 			supernodeoffset = offset;
608 
609 		if (offset == nodeoffset) {
610 			if (nodedepth)
611 				*nodedepth = depth;
612 
613 			if (supernodedepth > depth)
614 				return -FDT_ERR_NOTFOUND;
615 			else
616 				return supernodeoffset;
617 		}
618 	}
619 
620 	if (fdt_chk_extra()) {
621 		if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
622 			return -FDT_ERR_BADOFFSET;
623 		else if (offset == -FDT_ERR_BADOFFSET)
624 			return -FDT_ERR_BADSTRUCTURE;
625 	}
626 
627 	return offset; /* error from fdt_next_node() */
628 }
629 
fdt_node_depth(const void * fdt,int nodeoffset)630 int fdt_node_depth(const void *fdt, int nodeoffset)
631 {
632 	int nodedepth;
633 	int err;
634 
635 	err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
636 	if (err)
637 		return (!fdt_chk_extra() || err < 0) ? err : -FDT_ERR_INTERNAL;
638 	return nodedepth;
639 }
640 
fdt_parent_offset(const void * fdt,int nodeoffset)641 int fdt_parent_offset(const void *fdt, int nodeoffset)
642 {
643 	int nodedepth = fdt_node_depth(fdt, nodeoffset);
644 
645 	if (nodedepth < 0)
646 		return nodedepth;
647 	return fdt_supernode_atdepth_offset(fdt, nodeoffset,
648 					    nodedepth - 1, NULL);
649 }
650 
fdt_node_offset_by_prop_value(const void * fdt,int startoffset,const char * propname,const void * propval,int proplen)651 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
652 				  const char *propname,
653 				  const void *propval, int proplen)
654 {
655 	int offset;
656 	const void *val;
657 	int len;
658 
659 	FDT_RO_PROBE(fdt);
660 
661 	/* FIXME: The algorithm here is pretty horrible: we scan each
662 	 * property of a node in fdt_getprop(), then if that didn't
663 	 * find what we want, we scan over them again making our way
664 	 * to the next node.  Still it's the easiest to implement
665 	 * approach; performance can come later. */
666 	for (offset = fdt_next_node(fdt, startoffset, NULL);
667 	     offset >= 0;
668 	     offset = fdt_next_node(fdt, offset, NULL)) {
669 		val = fdt_getprop(fdt, offset, propname, &len);
670 		if (val && (len == proplen)
671 		    && (memcmp(val, propval, len) == 0))
672 			return offset;
673 	}
674 
675 	return offset; /* error from fdt_next_node() */
676 }
677 
fdt_node_offset_by_phandle(const void * fdt,uint32_t phandle)678 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
679 {
680 	int offset;
681 
682 	if ((phandle == 0) || (phandle == ~0U))
683 		return -FDT_ERR_BADPHANDLE;
684 
685 	FDT_RO_PROBE(fdt);
686 
687 	/* FIXME: The algorithm here is pretty horrible: we
688 	 * potentially scan each property of a node in
689 	 * fdt_get_phandle(), then if that didn't find what
690 	 * we want, we scan over them again making our way to the next
691 	 * node.  Still it's the easiest to implement approach;
692 	 * performance can come later. */
693 	for (offset = fdt_next_node(fdt, -1, NULL);
694 	     offset >= 0;
695 	     offset = fdt_next_node(fdt, offset, NULL)) {
696 		if (fdt_get_phandle(fdt, offset) == phandle)
697 			return offset;
698 	}
699 
700 	return offset; /* error from fdt_next_node() */
701 }
702 
fdt_stringlist_contains(const char * strlist,int listlen,const char * str)703 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
704 {
705 	int len = strlen(str);
706 	const char *p;
707 
708 	while (listlen >= len) {
709 		if (memcmp(str, strlist, len+1) == 0)
710 			return 1;
711 		p = memchr(strlist, '\0', listlen);
712 		if (!p)
713 			return 0; /* malformed strlist.. */
714 		listlen -= (p-strlist) + 1;
715 		strlist = p + 1;
716 	}
717 	return 0;
718 }
719 
fdt_stringlist_count(const void * fdt,int nodeoffset,const char * property)720 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
721 {
722 	const char *list, *end;
723 	int length, count = 0;
724 
725 	list = fdt_getprop(fdt, nodeoffset, property, &length);
726 	if (!list)
727 		return length;
728 
729 	end = list + length;
730 
731 	while (list < end) {
732 		length = strnlen(list, end - list) + 1;
733 
734 		/* Abort if the last string isn't properly NUL-terminated. */
735 		if (list + length > end)
736 			return -FDT_ERR_BADVALUE;
737 
738 		list += length;
739 		count++;
740 	}
741 
742 	return count;
743 }
744 
fdt_stringlist_search(const void * fdt,int nodeoffset,const char * property,const char * string)745 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
746 			  const char *string)
747 {
748 	int length, len, idx = 0;
749 	const char *list, *end;
750 
751 	list = fdt_getprop(fdt, nodeoffset, property, &length);
752 	if (!list)
753 		return length;
754 
755 	len = strlen(string) + 1;
756 	end = list + length;
757 
758 	while (list < end) {
759 		length = strnlen(list, end - list) + 1;
760 
761 		/* Abort if the last string isn't properly NUL-terminated. */
762 		if (list + length > end)
763 			return -FDT_ERR_BADVALUE;
764 
765 		if (length == len && memcmp(list, string, length) == 0)
766 			return idx;
767 
768 		list += length;
769 		idx++;
770 	}
771 
772 	return -FDT_ERR_NOTFOUND;
773 }
774 
fdt_stringlist_get(const void * fdt,int nodeoffset,const char * property,int idx,int * lenp)775 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
776 			       const char *property, int idx,
777 			       int *lenp)
778 {
779 	const char *list, *end;
780 	int length;
781 
782 	list = fdt_getprop(fdt, nodeoffset, property, &length);
783 	if (!list) {
784 		if (lenp)
785 			*lenp = length;
786 
787 		return NULL;
788 	}
789 
790 	end = list + length;
791 
792 	while (list < end) {
793 		length = strnlen(list, end - list) + 1;
794 
795 		/* Abort if the last string isn't properly NUL-terminated. */
796 		if (list + length > end) {
797 			if (lenp)
798 				*lenp = -FDT_ERR_BADVALUE;
799 
800 			return NULL;
801 		}
802 
803 		if (idx == 0) {
804 			if (lenp)
805 				*lenp = length - 1;
806 
807 			return list;
808 		}
809 
810 		list += length;
811 		idx--;
812 	}
813 
814 	if (lenp)
815 		*lenp = -FDT_ERR_NOTFOUND;
816 
817 	return NULL;
818 }
819 
fdt_node_check_compatible(const void * fdt,int nodeoffset,const char * compatible)820 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
821 			      const char *compatible)
822 {
823 	const void *prop;
824 	int len;
825 
826 	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
827 	if (!prop)
828 		return len;
829 
830 	return !fdt_stringlist_contains(prop, len, compatible);
831 }
832 
fdt_node_offset_by_compatible(const void * fdt,int startoffset,const char * compatible)833 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
834 				  const char *compatible)
835 {
836 	int offset, err;
837 
838 	FDT_RO_PROBE(fdt);
839 
840 	/* FIXME: The algorithm here is pretty horrible: we scan each
841 	 * property of a node in fdt_node_check_compatible(), then if
842 	 * that didn't find what we want, we scan over them again
843 	 * making our way to the next node.  Still it's the easiest to
844 	 * implement approach; performance can come later. */
845 	for (offset = fdt_next_node(fdt, startoffset, NULL);
846 	     offset >= 0;
847 	     offset = fdt_next_node(fdt, offset, NULL)) {
848 		err = fdt_node_check_compatible(fdt, offset, compatible);
849 		if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
850 			return err;
851 		else if (err == 0)
852 			return offset;
853 	}
854 
855 	return offset; /* error from fdt_next_node() */
856 }
857 
858 #if !defined(FDT_ASSUME_MASK) || FDT_ASSUME_MASK != 0xff
fdt_check_full(const void * fdt,size_t bufsize)859 int fdt_check_full(const void *fdt, size_t bufsize)
860 {
861 	int err;
862 	int num_memrsv;
863 	int offset, nextoffset = 0;
864 	uint32_t tag;
865 	unsigned depth = 0;
866 	const void *prop;
867 	const char *propname;
868 	bool expect_end = false;
869 
870 	if (bufsize < FDT_V1_SIZE)
871 		return -FDT_ERR_TRUNCATED;
872 	err = fdt_check_header(fdt);
873 	if (err != 0)
874 		return err;
875 	if (bufsize < fdt_totalsize(fdt))
876 		return -FDT_ERR_TRUNCATED;
877 
878 	num_memrsv = fdt_num_mem_rsv(fdt);
879 	if (num_memrsv < 0)
880 		return num_memrsv;
881 
882 	while (1) {
883 		offset = nextoffset;
884 		tag = fdt_next_tag(fdt, offset, &nextoffset);
885 
886 		if (nextoffset < 0)
887 			return nextoffset;
888 
889 		/* If we see two root nodes, something is wrong */
890 		if (expect_end && tag != FDT_END)
891 			return -FDT_ERR_BADLAYOUT;
892 
893 		switch (tag) {
894 		case FDT_NOP:
895 			break;
896 
897 		case FDT_END:
898 			if (depth != 0)
899 				return -FDT_ERR_BADSTRUCTURE;
900 			return 0;
901 
902 		case FDT_BEGIN_NODE:
903 			depth++;
904 			if (depth > INT_MAX)
905 				return -FDT_ERR_BADSTRUCTURE;
906 
907 			/* The root node must have an empty name */
908 			if (depth == 1) {
909 				const char *name;
910 				int len;
911 
912 				name = fdt_get_name(fdt, offset, &len);
913 				if (*name || len)
914 					return -FDT_ERR_BADLAYOUT;
915 			}
916 			break;
917 
918 		case FDT_END_NODE:
919 			if (depth == 0)
920 				return -FDT_ERR_BADSTRUCTURE;
921 			depth--;
922 			if (depth == 0)
923 				expect_end = true;
924 			break;
925 
926 		case FDT_PROP:
927 			prop = fdt_getprop_by_offset(fdt, offset, &propname,
928 						     &err);
929 			if (!prop)
930 				return err;
931 			break;
932 
933 		default:
934 			return -FDT_ERR_INTERNAL;
935 		}
936 	}
937 }
938 #else
fdt_check_full(const void __always_unused * fdt,size_t __always_unused bufsize)939 int fdt_check_full(const void __always_unused *fdt,
940 		   size_t __always_unused bufsize)
941 {
942 	return 0;
943 }
944 #endif /* #if !defined(FDT_ASSUME_MASK) || FDT_ASSUME_MASK != 0xff */
945