[linux.git] / scripts / dtc / libfdt / fdt.c

// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 */
#include "libfdt_env.h"

#include <fdt.h>
#include <libfdt.h>

#include "libfdt_internal.h"

/*
 * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
 * that the given buffer contains what appears to be a flattened
 * device tree with sane information in its header.
 */
int32_t fdt_ro_probe_(const void *fdt)
{
	uint32_t totalsize = fdt_totalsize(fdt);

	if (can_assume(VALID_DTB))
		return totalsize;

	/* The device tree must be at an 8-byte aligned address */
	if ((uintptr_t)fdt & 7)
		return -FDT_ERR_ALIGNMENT;

	if (fdt_magic(fdt) == FDT_MAGIC) {
		/* Complete tree */
		if (!can_assume(LATEST)) {
			if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
				return -FDT_ERR_BADVERSION;
			if (fdt_last_comp_version(fdt) >
					FDT_LAST_SUPPORTED_VERSION)
				return -FDT_ERR_BADVERSION;
		}
	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
		/* Unfinished sequential-write blob */
		if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0)
			return -FDT_ERR_BADSTATE;
	} else {
		return -FDT_ERR_BADMAGIC;
	}

	if (totalsize < INT32_MAX)
		return totalsize;
	else
		return -FDT_ERR_TRUNCATED;
}

static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
{
	return (off >= hdrsize) && (off <= totalsize);
}

static int check_block_(uint32_t hdrsize, uint32_t totalsize,
			uint32_t base, uint32_t size)
{
	if (!check_off_(hdrsize, totalsize, base))
		return 0; /* block start out of bounds */
	if ((base + size) < base)
		return 0; /* overflow */
	if (!check_off_(hdrsize, totalsize, base + size))
		return 0; /* block end out of bounds */
	return 1;
}

size_t fdt_header_size_(uint32_t version)
{
	if (version <= 1)
		return FDT_V1_SIZE;
	else if (version <= 2)
		return FDT_V2_SIZE;
	else if (version <= 3)
		return FDT_V3_SIZE;
	else if (version <= 16)
		return FDT_V16_SIZE;
	else
		return FDT_V17_SIZE;
}

size_t fdt_header_size(const void *fdt)
{
	return can_assume(LATEST) ? FDT_V17_SIZE :
		fdt_header_size_(fdt_version(fdt));
}

int fdt_check_header(const void *fdt)
{
	size_t hdrsize;

	if (fdt_magic(fdt) != FDT_MAGIC)
		return -FDT_ERR_BADMAGIC;
	if (!can_assume(LATEST)) {
		if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
		    || (fdt_last_comp_version(fdt) >
			FDT_LAST_SUPPORTED_VERSION))
			return -FDT_ERR_BADVERSION;
		if (fdt_version(fdt) < fdt_last_comp_version(fdt))
			return -FDT_ERR_BADVERSION;
	}
	hdrsize = fdt_header_size(fdt);
	if (!can_assume(VALID_DTB)) {

		if ((fdt_totalsize(fdt) < hdrsize)
		    || (fdt_totalsize(fdt) > INT_MAX))
			return -FDT_ERR_TRUNCATED;

		/* Bounds check memrsv block */
		if (!check_off_(hdrsize, fdt_totalsize(fdt),
				fdt_off_mem_rsvmap(fdt)))
			return -FDT_ERR_TRUNCATED;
	}

	if (!can_assume(VALID_DTB)) {
		/* Bounds check structure block */
		if (!can_assume(LATEST) && fdt_version(fdt) < 17) {
			if (!check_off_(hdrsize, fdt_totalsize(fdt),
					fdt_off_dt_struct(fdt)))
				return -FDT_ERR_TRUNCATED;
		} else {
			if (!check_block_(hdrsize, fdt_totalsize(fdt),
					  fdt_off_dt_struct(fdt),
					  fdt_size_dt_struct(fdt)))
				return -FDT_ERR_TRUNCATED;
		}

		/* Bounds check strings block */
		if (!check_block_(hdrsize, fdt_totalsize(fdt),
				  fdt_off_dt_strings(fdt),
				  fdt_size_dt_strings(fdt)))
			return -FDT_ERR_TRUNCATED;
	}

	return 0;
}

const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
{
	unsigned int uoffset = offset;
	unsigned int absoffset = offset + fdt_off_dt_struct(fdt);

	if (offset < 0)
		return NULL;

	if (!can_assume(VALID_INPUT))
		if ((absoffset < uoffset)
		    || ((absoffset + len) < absoffset)
		    || (absoffset + len) > fdt_totalsize(fdt))
			return NULL;

	if (can_assume(LATEST) || fdt_version(fdt) >= 0x11)
		if (((uoffset + len) < uoffset)
		    || ((offset + len) > fdt_size_dt_struct(fdt)))
			return NULL;

	return fdt_offset_ptr_(fdt, offset);
}

uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
{
	const fdt32_t *tagp, *lenp;
	uint32_t tag;
	int offset = startoffset;
	const char *p;

	*nextoffset = -FDT_ERR_TRUNCATED;
	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
	if (!can_assume(VALID_DTB) && !tagp)
		return FDT_END; /* premature end */
	tag = fdt32_to_cpu(*tagp);
	offset += FDT_TAGSIZE;

	*nextoffset = -FDT_ERR_BADSTRUCTURE;
	switch (tag) {
	case FDT_BEGIN_NODE:
		/* skip name */
		do {
			p = fdt_offset_ptr(fdt, offset++, 1);
		} while (p && (*p != '\0'));
		if (!can_assume(VALID_DTB) && !p)
			return FDT_END; /* premature end */
		break;

	case FDT_PROP:
		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
		if (!can_assume(VALID_DTB) && !lenp)
			return FDT_END; /* premature end */
		/* skip-name offset, length and value */
		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
			+ fdt32_to_cpu(*lenp);
		if (!can_assume(LATEST) &&
		    fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
		    ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
			offset += 4;
		break;

	case FDT_END:
	case FDT_END_NODE:
	case FDT_NOP:
		break;

	default:
		return FDT_END;
	}

	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
		return FDT_END; /* premature end */

	*nextoffset = FDT_TAGALIGN(offset);
	return tag;
}

int fdt_check_node_offset_(const void *fdt, int offset)
{
	if (!can_assume(VALID_INPUT)
	    && ((offset < 0) || (offset % FDT_TAGSIZE)))
		return -FDT_ERR_BADOFFSET;

	if (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)
		return -FDT_ERR_BADOFFSET;

	return offset;
}

int fdt_check_prop_offset_(const void *fdt, int offset)
{
	if (!can_assume(VALID_INPUT)
	    && ((offset < 0) || (offset % FDT_TAGSIZE)))
		return -FDT_ERR_BADOFFSET;

	if (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)
		return -FDT_ERR_BADOFFSET;

	return offset;
}

int fdt_next_node(const void *fdt, int offset, int *depth)
{
	int nextoffset = 0;
	uint32_t tag;

	if (offset >= 0)
		if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
			return nextoffset;

	do {
		offset = nextoffset;
		tag = fdt_next_tag(fdt, offset, &nextoffset);

		switch (tag) {
		case FDT_PROP:
		case FDT_NOP:
			break;

		case FDT_BEGIN_NODE:
			if (depth)
				(*depth)++;
			break;

		case FDT_END_NODE:
			if (depth && ((--(*depth)) < 0))
				return nextoffset;
			break;

		case FDT_END:
			if ((nextoffset >= 0)
			    || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
				return -FDT_ERR_NOTFOUND;
			else
				return nextoffset;
		}
	} while (tag != FDT_BEGIN_NODE);

	return offset;
}

int fdt_first_subnode(const void *fdt, int offset)
{
	int depth = 0;

	offset = fdt_next_node(fdt, offset, &depth);
	if (offset < 0 || depth != 1)
		return -FDT_ERR_NOTFOUND;

	return offset;
}

int fdt_next_subnode(const void *fdt, int offset)
{
	int depth = 1;

	/*
	 * With respect to the parent, the depth of the next subnode will be
	 * the same as the last.
	 */
	do {
		offset = fdt_next_node(fdt, offset, &depth);
		if (offset < 0 || depth < 1)
			return -FDT_ERR_NOTFOUND;
	} while (depth > 1);

	return offset;
}

const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
{
	int len = strlen(s) + 1;
	const char *last = strtab + tabsize - len;
	const char *p;

	for (p = strtab; p <= last; p++)
		if (memcmp(p, s, len) == 0)
			return p;
	return NULL;
}

int fdt_move(const void *fdt, void *buf, int bufsize)
{
	if (!can_assume(VALID_INPUT) && bufsize < 0)
		return -FDT_ERR_NOSPACE;

	FDT_RO_PROBE(fdt);

	if (fdt_totalsize(fdt) > (unsigned int)bufsize)
		return -FDT_ERR_NOSPACE;

	memmove(buf, fdt, fdt_totalsize(fdt));
	return 0;
}
Commit	Line	Data
12869ecd	1	// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
1cade994 DG	2	/*
	3	* libfdt - Flat Device Tree manipulation
	4	* Copyright (C) 2006 David Gibson, IBM Corporation.
1cade994 DG	5	*/
	6	#include "libfdt_env.h"
	7
	8	#include <fdt.h>
	9	#include <libfdt.h>
	10
	11	#include "libfdt_internal.h"
	12
f858927f RH	13	/*
	14	* Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
	15	* that the given buffer contains what appears to be a flattened
	16	* device tree with sane information in its header.
	17	*/
0cec114e	18	int32_t fdt_ro_probe_(const void *fdt)
1cade994	19	{
0cec114e RH	20	uint32_t totalsize = fdt_totalsize(fdt);
0cec114e RH	21
d047cd8a RH	22	if (can_assume(VALID_DTB))
	23	return totalsize;
	24
79edff12 RH	25	/* The device tree must be at an 8-byte aligned address */
	26	if ((uintptr_t)fdt & 7)
	27	return -FDT_ERR_ALIGNMENT;
	28
1cade994 DG	29	if (fdt_magic(fdt) == FDT_MAGIC) {
1cade994 DG	30	/* Complete tree */
d047cd8a RH	31	if (!can_assume(LATEST)) {
	32	if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
	33	return -FDT_ERR_BADVERSION;
	34	if (fdt_last_comp_version(fdt) >
	35	FDT_LAST_SUPPORTED_VERSION)
	36	return -FDT_ERR_BADVERSION;
	37	}
ed95d745	38	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
1cade994	39	/* Unfinished sequential-write blob */
d047cd8a	40	if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0)
1cade994 DG	41	return -FDT_ERR_BADSTATE;
	42	} else {
	43	return -FDT_ERR_BADMAGIC;
	44	}
	45
0cec114e RH	46	if (totalsize < INT32_MAX)
	47	return totalsize;
	48	else
	49	return -FDT_ERR_TRUNCATED;
1cade994 DG	50	}
1cade994 DG	51
f858927f RH	52	static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
	53	{
	54	return (off >= hdrsize) && (off <= totalsize);
	55	}
	56
	57	static int check_block_(uint32_t hdrsize, uint32_t totalsize,
	58	uint32_t base, uint32_t size)
	59	{
	60	if (!check_off_(hdrsize, totalsize, base))
	61	return 0; /* block start out of bounds */
	62	if ((base + size) < base)
	63	return 0; /* overflow */
	64	if (!check_off_(hdrsize, totalsize, base + size))
	65	return 0; /* block end out of bounds */
	66	return 1;
	67	}
	68
	69	size_t fdt_header_size_(uint32_t version)
	70	{
	71	if (version <= 1)
	72	return FDT_V1_SIZE;
	73	else if (version <= 2)
	74	return FDT_V2_SIZE;
	75	else if (version <= 3)
	76	return FDT_V3_SIZE;
	77	else if (version <= 16)
	78	return FDT_V16_SIZE;
	79	else
	80	return FDT_V17_SIZE;
	81	}
	82
d047cd8a RH	83	size_t fdt_header_size(const void *fdt)
	84	{
	85	return can_assume(LATEST) ? FDT_V17_SIZE :
	86	fdt_header_size_(fdt_version(fdt));
	87	}
	88
f858927f RH	89	int fdt_check_header(const void *fdt)
	90	{
	91	size_t hdrsize;
	92
	93	if (fdt_magic(fdt) != FDT_MAGIC)
	94	return -FDT_ERR_BADMAGIC;
d047cd8a RH	95	if (!can_assume(LATEST)) {
	96	if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
	97	\|\| (fdt_last_comp_version(fdt) >
	98	FDT_LAST_SUPPORTED_VERSION))
	99	return -FDT_ERR_BADVERSION;
	100	if (fdt_version(fdt) < fdt_last_comp_version(fdt))
	101	return -FDT_ERR_BADVERSION;
	102	}
f858927f	103	hdrsize = fdt_header_size(fdt);
d047cd8a	104	if (!can_assume(VALID_DTB)) {
f858927f	105
d047cd8a RH	106	if ((fdt_totalsize(fdt) < hdrsize)
	107	\|\| (fdt_totalsize(fdt) > INT_MAX))
	108	return -FDT_ERR_TRUNCATED;
f858927f	109
d047cd8a	110	/* Bounds check memrsv block */
f858927f	111	if (!check_off_(hdrsize, fdt_totalsize(fdt),
d047cd8a	112	fdt_off_mem_rsvmap(fdt)))
f858927f	113	return -FDT_ERR_TRUNCATED;
d047cd8a RH	114	}
	115
	116	if (!can_assume(VALID_DTB)) {
	117	/* Bounds check structure block */
	118	if (!can_assume(LATEST) && fdt_version(fdt) < 17) {
	119	if (!check_off_(hdrsize, fdt_totalsize(fdt),
	120	fdt_off_dt_struct(fdt)))
	121	return -FDT_ERR_TRUNCATED;
	122	} else {
	123	if (!check_block_(hdrsize, fdt_totalsize(fdt),
	124	fdt_off_dt_struct(fdt),
	125	fdt_size_dt_struct(fdt)))
	126	return -FDT_ERR_TRUNCATED;
	127	}
	128
	129	/* Bounds check strings block */
f858927f	130	if (!check_block_(hdrsize, fdt_totalsize(fdt),
d047cd8a RH	131	fdt_off_dt_strings(fdt),
d047cd8a RH	132	fdt_size_dt_strings(fdt)))
f858927f RH	133	return -FDT_ERR_TRUNCATED;
	134	}
	135
f858927f RH	136	return 0;
	137	}
	138
cd296721	139	const void fdt_offset_ptr(const void fdt, int offset, unsigned int len)
1cade994	140	{
6e9c9686 RH	141	unsigned int uoffset = offset;
	142	unsigned int absoffset = offset + fdt_off_dt_struct(fdt);
	143
	144	if (offset < 0)
	145	return NULL;
91feabc2	146
d047cd8a	147	if (!can_assume(VALID_INPUT))
6e9c9686	148	if ((absoffset < uoffset)
d047cd8a RH	149	\|\| ((absoffset + len) < absoffset)
	150	\|\| (absoffset + len) > fdt_totalsize(fdt))
	151	return NULL;
1cade994	152
d047cd8a	153	if (can_assume(LATEST) \|\| fdt_version(fdt) >= 0x11)
6e9c9686	154	if (((uoffset + len) < uoffset)
1cade994 DG	155	\|\| ((offset + len) > fdt_size_dt_struct(fdt)))
	156	return NULL;
	157
9130ba88	158	return fdt_offset_ptr_(fdt, offset);
1cade994 DG	159	}
1cade994 DG	160
cd296721	161	uint32_t fdt_next_tag(const void fdt, int startoffset, int nextoffset)
1cade994	162	{
47605971	163	const fdt32_t tagp, lenp;
1cade994	164	uint32_t tag;
cd296721	165	int offset = startoffset;
1cade994 DG	166	const char *p;
1cade994 DG	167
cd296721	168	*nextoffset = -FDT_ERR_TRUNCATED;
1cade994	169	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
d047cd8a	170	if (!can_assume(VALID_DTB) && !tagp)
1cade994 DG	171	return FDT_END; /* premature end */
	172	tag = fdt32_to_cpu(*tagp);
	173	offset += FDT_TAGSIZE;
	174
cd296721	175	*nextoffset = -FDT_ERR_BADSTRUCTURE;
1cade994 DG	176	switch (tag) {
	177	case FDT_BEGIN_NODE:
	178	/* skip name */
	179	do {
	180	p = fdt_offset_ptr(fdt, offset++, 1);
	181	} while (p && (*p != '\0'));
d047cd8a	182	if (!can_assume(VALID_DTB) && !p)
cd296721	183	return FDT_END; /* premature end */
1cade994	184	break;
cd296721	185
1cade994 DG	186	case FDT_PROP:
1cade994 DG	187	lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
d047cd8a	188	if (!can_assume(VALID_DTB) && !lenp)
cd296721 SW	189	return FDT_END; /* premature end */
	190	/* skip-name offset, length and value */
	191	offset += sizeof(struct fdt_property) - FDT_TAGSIZE
	192	+ fdt32_to_cpu(*lenp);
d047cd8a RH	193	if (!can_assume(LATEST) &&
d047cd8a RH	194	fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
9130ba88 RH	195	((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
9130ba88 RH	196	offset += 4;
cd296721 SW	197	break;
	198
	199	case FDT_END:
	200	case FDT_END_NODE:
	201	case FDT_NOP:
1cade994	202	break;
cd296721 SW	203
	204	default:
	205	return FDT_END;
1cade994 DG	206	}
1cade994 DG	207
cd296721 SW	208	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
cd296721 SW	209	return FDT_END; /* premature end */
1cade994	210
cd296721	211	*nextoffset = FDT_TAGALIGN(offset);
1cade994 DG	212	return tag;
	213	}
	214
9130ba88	215	int fdt_check_node_offset_(const void *fdt, int offset)
ed95d745	216	{
6e9c9686 RH	217	if (!can_assume(VALID_INPUT)
	218	&& ((offset < 0) \|\| (offset % FDT_TAGSIZE)))
	219	return -FDT_ERR_BADOFFSET;
	220
	221	if (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)
ed95d745 DG	222	return -FDT_ERR_BADOFFSET;
	223
	224	return offset;
	225	}
	226
9130ba88	227	int fdt_check_prop_offset_(const void *fdt, int offset)
cd296721	228	{
6e9c9686 RH	229	if (!can_assume(VALID_INPUT)
	230	&& ((offset < 0) \|\| (offset % FDT_TAGSIZE)))
	231	return -FDT_ERR_BADOFFSET;
	232
	233	if (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)
cd296721 SW	234	return -FDT_ERR_BADOFFSET;
	235
	236	return offset;
	237	}
	238
ed95d745 DG	239	int fdt_next_node(const void fdt, int offset, int depth)
	240	{
	241	int nextoffset = 0;
	242	uint32_t tag;
	243
	244	if (offset >= 0)
9130ba88	245	if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
ed95d745 DG	246	return nextoffset;
	247
	248	do {
	249	offset = nextoffset;
	250	tag = fdt_next_tag(fdt, offset, &nextoffset);
	251
	252	switch (tag) {
	253	case FDT_PROP:
	254	case FDT_NOP:
	255	break;
	256
	257	case FDT_BEGIN_NODE:
	258	if (depth)
	259	(*depth)++;
	260	break;
	261
	262	case FDT_END_NODE:
cd296721 SW	263	if (depth && ((--(*depth)) < 0))
cd296721 SW	264	return nextoffset;
ed95d745 DG	265	break;
	266
	267	case FDT_END:
cd296721 SW	268	if ((nextoffset >= 0)
	269	\|\| ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
	270	return -FDT_ERR_NOTFOUND;
	271	else
	272	return nextoffset;
ed95d745 DG	273	}
	274	} while (tag != FDT_BEGIN_NODE);
	275
	276	return offset;
	277	}
	278
47605971 RH	279	int fdt_first_subnode(const void *fdt, int offset)
	280	{
	281	int depth = 0;
	282
	283	offset = fdt_next_node(fdt, offset, &depth);
	284	if (offset < 0 \|\| depth != 1)
	285	return -FDT_ERR_NOTFOUND;
	286
	287	return offset;
	288	}
	289
	290	int fdt_next_subnode(const void *fdt, int offset)
	291	{
	292	int depth = 1;
	293
	294	/*
	295	* With respect to the parent, the depth of the next subnode will be
	296	* the same as the last.
	297	*/
	298	do {
	299	offset = fdt_next_node(fdt, offset, &depth);
	300	if (offset < 0 \|\| depth < 1)
	301	return -FDT_ERR_NOTFOUND;
	302	} while (depth > 1);
	303
	304	return offset;
	305	}
	306
9130ba88	307	const char fdt_find_string_(const char strtab, int tabsize, const char *s)
1cade994 DG	308	{
	309	int len = strlen(s) + 1;
	310	const char *last = strtab + tabsize - len;
	311	const char *p;
	312
	313	for (p = strtab; p <= last; p++)
ed95d745	314	if (memcmp(p, s, len) == 0)
1cade994 DG	315	return p;
	316	return NULL;
	317	}
	318
	319	int fdt_move(const void fdt, void buf, int bufsize)
	320	{
6e9c9686 RH	321	if (!can_assume(VALID_INPUT) && bufsize < 0)
	322	return -FDT_ERR_NOSPACE;
	323
f858927f	324	FDT_RO_PROBE(fdt);
1cade994	325
6e9c9686	326	if (fdt_totalsize(fdt) > (unsigned int)bufsize)
1cade994 DG	327	return -FDT_ERR_NOSPACE;
	328
	329	memmove(buf, fdt, fdt_totalsize(fdt));
	330	return 0;
	331	}