// SPDX-License-Identifier: GPL-2.0-only/* * vpd_decode.c * * Google VPD decoding routines. * * Copyright 2017 Google Inc. */ #include "vpd_decode.h" static int vpd_decode_len(const u32 max_len, const u8 *in,			  u32 *length, u32 *decoded_len){	u8 more;	int i = 0; 	if (!length || !decoded_len)		return VPD_FAIL; 	*length = 0;	do {		if (i >= max_len)			return VPD_FAIL; 		more = in[i] & 0x80;		*length <<= 7;		*length |= in[i] & 0x7f;		++i;	} while (more); 	*decoded_len = i;	return VPD_OK;} static int vpd_decode_entry(const u32 max_len, const u8 *input_buf,			    u32 *_consumed, const u8 **entry, u32 *entry_len){	u32 decoded_len;	u32 consumed = *_consumed; 	if (vpd_decode_len(max_len - consumed, &input_buf[consumed],			   entry_len, &decoded_len) != VPD_OK)		return VPD_FAIL;	if (max_len - consumed < decoded_len)		return VPD_FAIL; 	consumed += decoded_len;	*entry = input_buf + consumed; 	/* entry_len is untrusted data and must be checked again. */	if (max_len - consumed < *entry_len)		return VPD_FAIL; 	consumed += *entry_len;	*_consumed = consumed;	return VPD_OK;} int vpd_decode_string(const u32 max_len, const u8 *input_buf, u32 *consumed,		      vpd_decode_callback callback, void *callback_arg){	int type;	u32 key_len;	u32 value_len;	const u8 *key;	const u8 *value; 	/* type */	if (*consumed >= max_len)		return VPD_FAIL; 	type = input_buf[*consumed]; 	switch (type) {	case VPD_TYPE_INFO:	case VPD_TYPE_STRING:		(*consumed)++; 		if (vpd_decode_entry(max_len, input_buf, consumed, &key,				     &key_len) != VPD_OK)			return VPD_FAIL; 		if (vpd_decode_entry(max_len, input_buf, consumed, &value,				     &value_len) != VPD_OK)			return VPD_FAIL; 		if (type == VPD_TYPE_STRING)			return callback(key, key_len, value, value_len,					callback_arg);		break; 	default:		return VPD_FAIL;	} 	return VPD_OK;}