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 || 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 (can_assume(VALID_INPUT)) {
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 (can_assume(LATEST) || 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 (!can_assume(VALID_INPUT)) {
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 (!can_assume(VALID_INPUT) && !re)
182 return -FDT_ERR_BADOFFSET;
183
184 *address = fdt64_ld(&re->address);
185 *size = fdt64_ld(&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_ld(&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 (((err = fdt_ro_probe_(fdt)) < 0)
307 || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
308 goto fail;
309
310 nameptr = nh->name;
311
312 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
313 /*
314 * For old FDT versions, match the naming conventions of V16:
315 * give only the leaf name (after all /). The actual tree
316 * contents are loosely checked.
317 */
318 const char *leaf;
319 leaf = strrchr(nameptr, '/');
320 if (leaf == NULL) {
321 err = -FDT_ERR_BADSTRUCTURE;
322 goto fail;
323 }
324 nameptr = leaf+1;
325 }
326
327 if (len)
328 *len = strlen(nameptr);
329
330 return nameptr;
331
332 fail:
333 if (len)
334 *len = err;
335 return NULL;
336 }
337
fdt_first_property_offset(const void * fdt,int nodeoffset)338 int fdt_first_property_offset(const void *fdt, int nodeoffset)
339 {
340 int offset;
341
342 if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
343 return offset;
344
345 return nextprop_(fdt, offset);
346 }
347
fdt_next_property_offset(const void * fdt,int offset)348 int fdt_next_property_offset(const void *fdt, int offset)
349 {
350 if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
351 return offset;
352
353 return nextprop_(fdt, offset);
354 }
355
fdt_get_property_by_offset_(const void * fdt,int offset,int * lenp)356 static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
357 int offset,
358 int *lenp)
359 {
360 int err;
361 const struct fdt_property *prop;
362
363 if (!can_assume(VALID_INPUT) &&
364 (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_ld(&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 (!can_assume(LATEST) && 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 (!can_assume(LIBFDT_FLAWLESS) && !prop) {
408 offset = -FDT_ERR_INTERNAL;
409 break;
410 }
411 if (fdt_string_eq_(fdt, fdt32_ld(&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
424
fdt_get_property_namelen(const void * fdt,int offset,const char * name,int namelen,int * lenp)425 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
426 int offset,
427 const char *name,
428 int namelen, int *lenp)
429 {
430 /* Prior to version 16, properties may need realignment
431 * and this API does not work. fdt_getprop_*() will, however. */
432 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
433 if (lenp)
434 *lenp = -FDT_ERR_BADVERSION;
435 return NULL;
436 }
437
438 return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
439 NULL);
440 }
441
442
fdt_get_property(const void * fdt,int nodeoffset,const char * name,int * lenp)443 const struct fdt_property *fdt_get_property(const void *fdt,
444 int nodeoffset,
445 const char *name, int *lenp)
446 {
447 return fdt_get_property_namelen(fdt, nodeoffset, name,
448 strlen(name), lenp);
449 }
450
fdt_getprop_namelen(const void * fdt,int nodeoffset,const char * name,int namelen,int * lenp)451 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
452 const char *name, int namelen, int *lenp)
453 {
454 int poffset;
455 const struct fdt_property *prop;
456
457 prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
458 &poffset);
459 if (!prop)
460 return NULL;
461
462 /* Handle realignment */
463 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
464 (poffset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
465 return prop->data + 4;
466 return prop->data;
467 }
468
fdt_getprop_by_offset(const void * fdt,int offset,const char ** namep,int * lenp)469 const void *fdt_getprop_by_offset(const void *fdt, int offset,
470 const char **namep, int *lenp)
471 {
472 const struct fdt_property *prop;
473
474 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
475 if (!prop)
476 return NULL;
477 if (namep) {
478 const char *name;
479 int namelen;
480
481 if (!can_assume(VALID_INPUT)) {
482 name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
483 &namelen);
484 if (!name) {
485 if (lenp)
486 *lenp = namelen;
487 return NULL;
488 }
489 *namep = name;
490 } else {
491 *namep = fdt_string(fdt, fdt32_ld(&prop->nameoff));
492 }
493 }
494
495 /* Handle realignment */
496 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
497 (offset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
498 return prop->data + 4;
499 return prop->data;
500 }
501
fdt_getprop(const void * fdt,int nodeoffset,const char * name,int * lenp)502 const void *fdt_getprop(const void *fdt, int nodeoffset,
503 const char *name, int *lenp)
504 {
505 return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
506 }
507
fdt_get_phandle(const void * fdt,int nodeoffset)508 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
509 {
510 const fdt32_t *php;
511 int len;
512
513 /* FIXME: This is a bit sub-optimal, since we potentially scan
514 * over all the properties twice. */
515 php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
516 if (!php || (len != sizeof(*php))) {
517 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
518 if (!php || (len != sizeof(*php)))
519 return 0;
520 }
521
522 return fdt32_ld(php);
523 }
524
fdt_get_alias_namelen(const void * fdt,const char * name,int namelen)525 const char *fdt_get_alias_namelen(const void *fdt,
526 const char *name, int namelen)
527 {
528 int aliasoffset;
529
530 aliasoffset = fdt_path_offset(fdt, "/aliases");
531 if (aliasoffset < 0)
532 return NULL;
533
534 return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
535 }
536
fdt_get_alias(const void * fdt,const char * name)537 const char *fdt_get_alias(const void *fdt, const char *name)
538 {
539 return fdt_get_alias_namelen(fdt, name, strlen(name));
540 }
541
fdt_get_path(const void * fdt,int nodeoffset,char * buf,int buflen)542 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
543 {
544 int pdepth = 0, p = 0;
545 int offset, depth, namelen;
546 const char *name;
547
548 FDT_RO_PROBE(fdt);
549
550 if (buflen < 2)
551 return -FDT_ERR_NOSPACE;
552
553 for (offset = 0, depth = 0;
554 (offset >= 0) && (offset <= nodeoffset);
555 offset = fdt_next_node(fdt, offset, &depth)) {
556 while (pdepth > depth) {
557 do {
558 p--;
559 } while (buf[p-1] != '/');
560 pdepth--;
561 }
562
563 if (pdepth >= depth) {
564 name = fdt_get_name(fdt, offset, &namelen);
565 if (!name)
566 return namelen;
567 if ((p + namelen + 1) <= buflen) {
568 memcpy(buf + p, name, namelen);
569 p += namelen;
570 buf[p++] = '/';
571 pdepth++;
572 }
573 }
574
575 if (offset == nodeoffset) {
576 if (pdepth < (depth + 1))
577 return -FDT_ERR_NOSPACE;
578
579 if (p > 1) /* special case so that root path is "/", not "" */
580 p--;
581 buf[p] = '\0';
582 return 0;
583 }
584 }
585
586 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
587 return -FDT_ERR_BADOFFSET;
588 else if (offset == -FDT_ERR_BADOFFSET)
589 return -FDT_ERR_BADSTRUCTURE;
590
591 return offset; /* error from fdt_next_node() */
592 }
593
fdt_supernode_atdepth_offset(const void * fdt,int nodeoffset,int supernodedepth,int * nodedepth)594 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
595 int supernodedepth, int *nodedepth)
596 {
597 int offset, depth;
598 int supernodeoffset = -FDT_ERR_INTERNAL;
599
600 FDT_RO_PROBE(fdt);
601
602 if (supernodedepth < 0)
603 return -FDT_ERR_NOTFOUND;
604
605 for (offset = 0, depth = 0;
606 (offset >= 0) && (offset <= nodeoffset);
607 offset = fdt_next_node(fdt, offset, &depth)) {
608 if (depth == supernodedepth)
609 supernodeoffset = offset;
610
611 if (offset == nodeoffset) {
612 if (nodedepth)
613 *nodedepth = depth;
614
615 if (supernodedepth > depth)
616 return -FDT_ERR_NOTFOUND;
617 else
618 return supernodeoffset;
619 }
620 }
621
622 if (!can_assume(VALID_INPUT)) {
623 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
624 return -FDT_ERR_BADOFFSET;
625 else if (offset == -FDT_ERR_BADOFFSET)
626 return -FDT_ERR_BADSTRUCTURE;
627 }
628
629 return offset; /* error from fdt_next_node() */
630 }
631
fdt_node_depth(const void * fdt,int nodeoffset)632 int fdt_node_depth(const void *fdt, int nodeoffset)
633 {
634 int nodedepth;
635 int err;
636
637 err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
638 if (err)
639 return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err :
640 -FDT_ERR_INTERNAL;
641 return nodedepth;
642 }
643
fdt_parent_offset(const void * fdt,int nodeoffset)644 int fdt_parent_offset(const void *fdt, int nodeoffset)
645 {
646 int nodedepth = fdt_node_depth(fdt, nodeoffset);
647
648 if (nodedepth < 0)
649 return nodedepth;
650 return fdt_supernode_atdepth_offset(fdt, nodeoffset,
651 nodedepth - 1, NULL);
652 }
653
fdt_node_offset_by_prop_value(const void * fdt,int startoffset,const char * propname,const void * propval,int proplen)654 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
655 const char *propname,
656 const void *propval, int proplen)
657 {
658 int offset;
659 const void *val;
660 int len;
661
662 FDT_RO_PROBE(fdt);
663
664 /* FIXME: The algorithm here is pretty horrible: we scan each
665 * property of a node in fdt_getprop(), then if that didn't
666 * find what we want, we scan over them again making our way
667 * to the next node. Still it's the easiest to implement
668 * approach; performance can come later. */
669 for (offset = fdt_next_node(fdt, startoffset, NULL);
670 offset >= 0;
671 offset = fdt_next_node(fdt, offset, NULL)) {
672 val = fdt_getprop(fdt, offset, propname, &len);
673 if (val && (len == proplen)
674 && (memcmp(val, propval, len) == 0))
675 return offset;
676 }
677
678 return offset; /* error from fdt_next_node() */
679 }
680
fdt_node_offset_by_phandle(const void * fdt,uint32_t phandle)681 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
682 {
683 int offset;
684
685 if ((phandle == 0) || (phandle == ~0U))
686 return -FDT_ERR_BADPHANDLE;
687
688 FDT_RO_PROBE(fdt);
689
690 /* FIXME: The algorithm here is pretty horrible: we
691 * potentially scan each property of a node in
692 * fdt_get_phandle(), then if that didn't find what
693 * we want, we scan over them again making our way to the next
694 * node. Still it's the easiest to implement approach;
695 * performance can come later. */
696 for (offset = fdt_next_node(fdt, -1, NULL);
697 offset >= 0;
698 offset = fdt_next_node(fdt, offset, NULL)) {
699 if (fdt_get_phandle(fdt, offset) == phandle)
700 return offset;
701 }
702
703 return offset; /* error from fdt_next_node() */
704 }
705
fdt_stringlist_contains(const char * strlist,int listlen,const char * str)706 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
707 {
708 int len = strlen(str);
709 const char *p;
710
711 while (listlen >= len) {
712 if (memcmp(str, strlist, len+1) == 0)
713 return 1;
714 p = memchr(strlist, '\0', listlen);
715 if (!p)
716 return 0; /* malformed strlist.. */
717 listlen -= (p-strlist) + 1;
718 strlist = p + 1;
719 }
720 return 0;
721 }
722
fdt_stringlist_count(const void * fdt,int nodeoffset,const char * property)723 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
724 {
725 const char *list, *end;
726 int length, count = 0;
727
728 list = fdt_getprop(fdt, nodeoffset, property, &length);
729 if (!list)
730 return length;
731
732 end = list + length;
733
734 while (list < end) {
735 length = strnlen(list, end - list) + 1;
736
737 /* Abort if the last string isn't properly NUL-terminated. */
738 if (list + length > end)
739 return -FDT_ERR_BADVALUE;
740
741 list += length;
742 count++;
743 }
744
745 return count;
746 }
747
fdt_stringlist_search(const void * fdt,int nodeoffset,const char * property,const char * string)748 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
749 const char *string)
750 {
751 int length, len, idx = 0;
752 const char *list, *end;
753
754 list = fdt_getprop(fdt, nodeoffset, property, &length);
755 if (!list)
756 return length;
757
758 len = strlen(string) + 1;
759 end = list + length;
760
761 while (list < end) {
762 length = strnlen(list, end - list) + 1;
763
764 /* Abort if the last string isn't properly NUL-terminated. */
765 if (list + length > end)
766 return -FDT_ERR_BADVALUE;
767
768 if (length == len && memcmp(list, string, length) == 0)
769 return idx;
770
771 list += length;
772 idx++;
773 }
774
775 return -FDT_ERR_NOTFOUND;
776 }
777
fdt_stringlist_get(const void * fdt,int nodeoffset,const char * property,int idx,int * lenp)778 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
779 const char *property, int idx,
780 int *lenp)
781 {
782 const char *list, *end;
783 int length;
784
785 list = fdt_getprop(fdt, nodeoffset, property, &length);
786 if (!list) {
787 if (lenp)
788 *lenp = length;
789
790 return NULL;
791 }
792
793 end = list + length;
794
795 while (list < end) {
796 length = strnlen(list, end - list) + 1;
797
798 /* Abort if the last string isn't properly NUL-terminated. */
799 if (list + length > end) {
800 if (lenp)
801 *lenp = -FDT_ERR_BADVALUE;
802
803 return NULL;
804 }
805
806 if (idx == 0) {
807 if (lenp)
808 *lenp = length - 1;
809
810 return list;
811 }
812
813 list += length;
814 idx--;
815 }
816
817 if (lenp)
818 *lenp = -FDT_ERR_NOTFOUND;
819
820 return NULL;
821 }
822
fdt_node_check_compatible(const void * fdt,int nodeoffset,const char * compatible)823 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
824 const char *compatible)
825 {
826 const void *prop;
827 int len;
828
829 prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
830 if (!prop)
831 return len;
832
833 return !fdt_stringlist_contains(prop, len, compatible);
834 }
835
fdt_node_offset_by_compatible(const void * fdt,int startoffset,const char * compatible)836 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
837 const char *compatible)
838 {
839 int offset, err;
840
841 FDT_RO_PROBE(fdt);
842
843 /* FIXME: The algorithm here is pretty horrible: we scan each
844 * property of a node in fdt_node_check_compatible(), then if
845 * that didn't find what we want, we scan over them again
846 * making our way to the next node. Still it's the easiest to
847 * implement approach; performance can come later. */
848 for (offset = fdt_next_node(fdt, startoffset, NULL);
849 offset >= 0;
850 offset = fdt_next_node(fdt, offset, NULL)) {
851 err = fdt_node_check_compatible(fdt, offset, compatible);
852 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
853 return err;
854 else if (err == 0)
855 return offset;
856 }
857
858 return offset; /* error from fdt_next_node() */
859 }
860