scripts/dtc/libfdt/fdt.c - third_party/linux - Git at Google

 // 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;
 }
	// 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;
	}