[u-boot.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 (fdt_magic(fdt) == FDT_MAGIC) {
		/* Complete tree */
		if (fdt_chk_version()) {
			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 (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 fdt_chk_version() ? fdt_header_size_(fdt_version(fdt)) :
		FDT_V17_SIZE;
}

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

	if (fdt_magic(fdt) != FDT_MAGIC)
		return -FDT_ERR_BADMAGIC;
	if (fdt_chk_version()) {
		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 (fdt_chk_basic()) {

		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 (fdt_chk_extra()) {
		/* Bounds check structure block */
		if (fdt_chk_version() && 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 absoffset = offset + fdt_off_dt_struct(fdt);

	if (fdt_chk_basic())
		if ((absoffset < offset)
		    || ((absoffset + len) < absoffset)
		    || (absoffset + len) > fdt_totalsize(fdt))
			return NULL;

	if (!fdt_chk_version() || fdt_version(fdt) >= 0x11)
		if (((offset + len) < offset)
		    || ((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 (fdt_chk_basic() && !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 (fdt_chk_basic() && !p)
			return FDT_END; /* premature end */
		break;

	case FDT_PROP:
		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
		if (fdt_chk_basic() && !lenp)
			return FDT_END; /* premature end */
		/* skip-name offset, length and value */
		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
			+ fdt32_to_cpu(*lenp);
		if (fdt_chk_version() &&
		    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_chk_basic() &&
	    !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 ((offset < 0) || (offset % FDT_TAGSIZE)
	    || (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 ((offset < 0) || (offset % FDT_TAGSIZE)
	    || (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)
{
	FDT_RO_PROBE(fdt);

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

	memmove(buf, fdt, fdt_totalsize(fdt));
	return 0;
}
Commit	Line	Data
f0921f50	1	// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
c0e032e0 TR	2	/*
	3	* libfdt - Flat Device Tree manipulation
	4	* Copyright (C) 2006 David Gibson, IBM Corporation.
c0e032e0 TR	5	*/
	6	#include "libfdt_env.h"
	7
	8	#include <fdt.h>
	9	#include <libfdt.h>
	10
	11	#include "libfdt_internal.h"
	12
f0921f50 SG	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	*/
	18	int32_t fdt_ro_probe_(const void *fdt)
c0e032e0	19	{
f0921f50 SG	20	uint32_t totalsize = fdt_totalsize(fdt);
f0921f50 SG	21
c0e032e0 TR	22	if (fdt_magic(fdt) == FDT_MAGIC) {
c0e032e0 TR	23	/* Complete tree */
f0921f50 SG	24	if (fdt_chk_version()) {
	25	if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
	26	return -FDT_ERR_BADVERSION;
	27	if (fdt_last_comp_version(fdt) >
	28	FDT_LAST_SUPPORTED_VERSION)
	29	return -FDT_ERR_BADVERSION;
	30	}
c0e032e0 TR	31	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
	32	/* Unfinished sequential-write blob */
	33	if (fdt_size_dt_struct(fdt) == 0)
	34	return -FDT_ERR_BADSTATE;
	35	} else {
	36	return -FDT_ERR_BADMAGIC;
	37	}
	38
f0921f50 SG	39	if (totalsize < INT32_MAX)
	40	return totalsize;
	41	else
	42	return -FDT_ERR_TRUNCATED;
	43	}
	44
	45	static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
	46	{
	47	return (off >= hdrsize) && (off <= totalsize);
	48	}
	49
	50	static int check_block_(uint32_t hdrsize, uint32_t totalsize,
	51	uint32_t base, uint32_t size)
	52	{
	53	if (!check_off_(hdrsize, totalsize, base))
	54	return 0; /* block start out of bounds */
	55	if ((base + size) < base)
	56	return 0; /* overflow */
	57	if (!check_off_(hdrsize, totalsize, base + size))
	58	return 0; /* block end out of bounds */
	59	return 1;
	60	}
	61
	62	size_t fdt_header_size_(uint32_t version)
	63	{
	64	if (version <= 1)
	65	return FDT_V1_SIZE;
	66	else if (version <= 2)
	67	return FDT_V2_SIZE;
	68	else if (version <= 3)
	69	return FDT_V3_SIZE;
	70	else if (version <= 16)
	71	return FDT_V16_SIZE;
	72	else
	73	return FDT_V17_SIZE;
	74	}
	75
	76	size_t fdt_header_size(const void *fdt)
	77	{
	78	return fdt_chk_version() ? fdt_header_size_(fdt_version(fdt)) :
	79	FDT_V17_SIZE;
	80	}
	81
	82	int fdt_check_header(const void *fdt)
	83	{
	84	size_t hdrsize;
	85
	86	if (fdt_magic(fdt) != FDT_MAGIC)
	87	return -FDT_ERR_BADMAGIC;
	88	if (fdt_chk_version()) {
	89	if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
	90	\|\| (fdt_last_comp_version(fdt) >
	91	FDT_LAST_SUPPORTED_VERSION))
	92	return -FDT_ERR_BADVERSION;
	93	if (fdt_version(fdt) < fdt_last_comp_version(fdt))
	94	return -FDT_ERR_BADVERSION;
	95	}
	96	hdrsize = fdt_header_size(fdt);
	97	if (fdt_chk_basic()) {
	98
	99	if ((fdt_totalsize(fdt) < hdrsize)
	100	\|\| (fdt_totalsize(fdt) > INT_MAX))
	101	return -FDT_ERR_TRUNCATED;
	102
103	/* Bounds check memrsv block */
104	if (!check_off_(hdrsize, fdt_totalsize(fdt),
105	fdt_off_mem_rsvmap(fdt)))
106	return -FDT_ERR_TRUNCATED;
107	}
108
109	if (fdt_chk_extra()) {
110	/* Bounds check structure block */
111	if (fdt_chk_version() && fdt_version(fdt) < 17) {
112	if (!check_off_(hdrsize, fdt_totalsize(fdt),
113	fdt_off_dt_struct(fdt)))
114	return -FDT_ERR_TRUNCATED;
115	} else {
116	if (!check_block_(hdrsize, fdt_totalsize(fdt),
117	fdt_off_dt_struct(fdt),
118	fdt_size_dt_struct(fdt)))
119	return -FDT_ERR_TRUNCATED;
120	}
121
122	/* Bounds check strings block */
123	if (!check_block_(hdrsize, fdt_totalsize(fdt),
124	fdt_off_dt_strings(fdt),
125	fdt_size_dt_strings(fdt)))
126	return -FDT_ERR_TRUNCATED;
127	}
128
c0e032e0 TR	129	return 0;
	130	}
	131
	132	const void fdt_offset_ptr(const void fdt, int offset, unsigned int len)
	133	{
	134	unsigned absoffset = offset + fdt_off_dt_struct(fdt);
	135
f0921f50 SG	136	if (fdt_chk_basic())
	137	if ((absoffset < offset)
	138	\|\| ((absoffset + len) < absoffset)
	139	\|\| (absoffset + len) > fdt_totalsize(fdt))
	140	return NULL;
c0e032e0	141
f0921f50	142	if (!fdt_chk_version() \|\| fdt_version(fdt) >= 0x11)
c0e032e0 TR	143	if (((offset + len) < offset)
	144	\|\| ((offset + len) > fdt_size_dt_struct(fdt)))
	145	return NULL;
	146
db405d19	147	return fdt_offset_ptr_(fdt, offset);
c0e032e0 TR	148	}
	149
	150	uint32_t fdt_next_tag(const void fdt, int startoffset, int nextoffset)
	151	{
	152	const fdt32_t tagp, lenp;
	153	uint32_t tag;
	154	int offset = startoffset;
	155	const char *p;
	156
	157	*nextoffset = -FDT_ERR_TRUNCATED;
	158	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
f0921f50	159	if (fdt_chk_basic() && !tagp)
c0e032e0 TR	160	return FDT_END; /* premature end */
	161	tag = fdt32_to_cpu(*tagp);
	162	offset += FDT_TAGSIZE;
	163
	164	*nextoffset = -FDT_ERR_BADSTRUCTURE;
	165	switch (tag) {
	166	case FDT_BEGIN_NODE:
	167	/* skip name */
	168	do {
	169	p = fdt_offset_ptr(fdt, offset++, 1);
	170	} while (p && (*p != '\0'));
f0921f50	171	if (fdt_chk_basic() && !p)
c0e032e0 TR	172	return FDT_END; /* premature end */
	173	break;
	174
	175	case FDT_PROP:
	176	lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
f0921f50	177	if (fdt_chk_basic() && !lenp)
c0e032e0 TR	178	return FDT_END; /* premature end */
	179	/* skip-name offset, length and value */
	180	offset += sizeof(struct fdt_property) - FDT_TAGSIZE
	181	+ fdt32_to_cpu(*lenp);
f0921f50 SG	182	if (fdt_chk_version() &&
f0921f50 SG	183	fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
db405d19 RH	184	((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
db405d19 RH	185	offset += 4;
c0e032e0 TR	186	break;
	187
	188	case FDT_END:
	189	case FDT_END_NODE:
	190	case FDT_NOP:
	191	break;
	192
	193	default:
	194	return FDT_END;
	195	}
	196
f0921f50 SG	197	if (fdt_chk_basic() &&
f0921f50 SG	198	!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
c0e032e0 TR	199	return FDT_END; /* premature end */
	200
	201	*nextoffset = FDT_TAGALIGN(offset);
	202	return tag;
	203	}
	204
db405d19	205	int fdt_check_node_offset_(const void *fdt, int offset)
c0e032e0 TR	206	{
	207	if ((offset < 0) \|\| (offset % FDT_TAGSIZE)
	208	\|\| (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
	209	return -FDT_ERR_BADOFFSET;
	210
	211	return offset;
	212	}
	213
db405d19	214	int fdt_check_prop_offset_(const void *fdt, int offset)
c0e032e0 TR	215	{
	216	if ((offset < 0) \|\| (offset % FDT_TAGSIZE)
	217	\|\| (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
	218	return -FDT_ERR_BADOFFSET;
	219
	220	return offset;
	221	}
	222
	223	int fdt_next_node(const void fdt, int offset, int depth)
	224	{
	225	int nextoffset = 0;
	226	uint32_t tag;
	227
	228	if (offset >= 0)
db405d19	229	if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
c0e032e0 TR	230	return nextoffset;
	231
	232	do {
	233	offset = nextoffset;
	234	tag = fdt_next_tag(fdt, offset, &nextoffset);
	235
	236	switch (tag) {
	237	case FDT_PROP:
	238	case FDT_NOP:
	239	break;
	240
	241	case FDT_BEGIN_NODE:
	242	if (depth)
	243	(*depth)++;
	244	break;
	245
	246	case FDT_END_NODE:
	247	if (depth && ((--(*depth)) < 0))
	248	return nextoffset;
	249	break;
	250
	251	case FDT_END:
	252	if ((nextoffset >= 0)
	253	\|\| ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
	254	return -FDT_ERR_NOTFOUND;
	255	else
	256	return nextoffset;
	257	}
	258	} while (tag != FDT_BEGIN_NODE);
	259
	260	return offset;
	261	}
	262
	263	int fdt_first_subnode(const void *fdt, int offset)
	264	{
	265	int depth = 0;
	266
	267	offset = fdt_next_node(fdt, offset, &depth);
	268	if (offset < 0 \|\| depth != 1)
	269	return -FDT_ERR_NOTFOUND;
	270
	271	return offset;
	272	}
	273
	274	int fdt_next_subnode(const void *fdt, int offset)
	275	{
	276	int depth = 1;
	277
	278	/*
	279	* With respect to the parent, the depth of the next subnode will be
	280	* the same as the last.
	281	*/
	282	do {
	283	offset = fdt_next_node(fdt, offset, &depth);
	284	if (offset < 0 \|\| depth < 1)
	285	return -FDT_ERR_NOTFOUND;
	286	} while (depth > 1);
	287
	288	return offset;
	289	}
	290
db405d19	291	const char fdt_find_string_(const char strtab, int tabsize, const char *s)
c0e032e0 TR	292	{
	293	int len = strlen(s) + 1;
	294	const char *last = strtab + tabsize - len;
	295	const char *p;
	296
	297	for (p = strtab; p <= last; p++)
	298	if (memcmp(p, s, len) == 0)
	299	return p;
	300	return NULL;
	301	}
	302
	303	int fdt_move(const void fdt, void buf, int bufsize)
	304	{
f0921f50	305	FDT_RO_PROBE(fdt);
c0e032e0 TR	306
	307	if (fdt_totalsize(fdt) > bufsize)
	308	return -FDT_ERR_NOSPACE;
	309
	310	memmove(buf, fdt, fdt_totalsize(fdt));
	311	return 0;
	312	}