From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/firmware/google/vpd_decode.c | 98 ++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 drivers/firmware/google/vpd_decode.c (limited to 'drivers/firmware/google/vpd_decode.c') diff --git a/drivers/firmware/google/vpd_decode.c b/drivers/firmware/google/vpd_decode.c new file mode 100644 index 000000000..5c6f2a74f --- /dev/null +++ b/drivers/firmware/google/vpd_decode.c @@ -0,0 +1,98 @@ +// 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; +} -- cgit v1.2.3