Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * vpd_decode.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Google VPD decoding routines.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * Copyright 2017 Google Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "vpd_decode.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) static int vpd_decode_len(const u32 max_len, const u8 *in,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 			  u32 *length, u32 *decoded_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	u8 more;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	int i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	if (!length || !decoded_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	*length = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		if (i >= max_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 			return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		more = in[i] & 0x80;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		*length <<= 7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		*length |= in[i] & 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 		++i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	} while (more);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	*decoded_len = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	return VPD_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static int vpd_decode_entry(const u32 max_len, const u8 *input_buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 			    u32 *_consumed, const u8 **entry, u32 *entry_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	u32 decoded_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	u32 consumed = *_consumed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	if (vpd_decode_len(max_len - consumed, &input_buf[consumed],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 			   entry_len, &decoded_len) != VPD_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	if (max_len - consumed < decoded_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	consumed += decoded_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	*entry = input_buf + consumed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	/* entry_len is untrusted data and must be checked again. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	if (max_len - consumed < *entry_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	consumed += *entry_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	*_consumed = consumed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	return VPD_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) int vpd_decode_string(const u32 max_len, const u8 *input_buf, u32 *consumed,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 		      vpd_decode_callback callback, void *callback_arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 	int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	u32 key_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	u32 value_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	const u8 *key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	const u8 *value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	/* type */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 	if (*consumed >= max_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	type = input_buf[*consumed];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	switch (type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 	case VPD_TYPE_INFO:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 	case VPD_TYPE_STRING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 		(*consumed)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 		if (vpd_decode_entry(max_len, input_buf, consumed, &key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 				     &key_len) != VPD_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 			return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 		if (vpd_decode_entry(max_len, input_buf, consumed, &value,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 				     &value_len) != VPD_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 			return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) 		if (type == VPD_TYPE_STRING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) 			return callback(key, key_len, value, value_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) 					callback_arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) 		return VPD_FAIL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) 	return VPD_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }