// 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; 	/* 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)		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; 		/* memrsv block must be 8 byte aligned */		if (fdt_off_mem_rsvmap(fdt) % sizeof(uint64_t))			return -FDT_ERR_ALIGNMENT; 		/* Structure block must be 4 byte aligned */		if (fdt_off_dt_struct(fdt) % FDT_TAGSIZE)			return -FDT_ERR_ALIGNMENT; 		/* Bounds check memrsv block */		if (!check_off_(hdrsize, fdt_totalsize(fdt),				fdt_off_mem_rsvmap(fdt)))			return -FDT_ERR_TRUNCATED; 		/* 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, len, sum;	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 */ 		len = fdt32_to_cpu(*lenp);		sum = len + offset;		if (!can_assume(VALID_DTB) &&		    (INT_MAX <= sum || sum < (uint32_t) offset))			return FDT_END; /* premature end */ 		/* skip-name offset, length and value */		offset += sizeof(struct fdt_property) - FDT_TAGSIZE + len; 		if (!can_assume(LATEST) &&		    fdt_version(fdt) < 0x10 && len >= 8 &&		    ((offset - len) % 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_len_(const char *strtab, int tabsize, const char *s,				 int slen){	const char *last = strtab + tabsize - (slen + 1);	const char *p; 	for (p = strtab; p <= last; p++)		if (memcmp(p, s, slen) == 0 && p[slen] == '\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;}