diff options
Diffstat (limited to 'src/vendorcode/google/chromeos/vpd_decode.c')
-rw-r--r-- | src/vendorcode/google/chromeos/vpd_decode.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/vendorcode/google/chromeos/vpd_decode.c b/src/vendorcode/google/chromeos/vpd_decode.c new file mode 100644 index 0000000000..545fd8106f --- /dev/null +++ b/src/vendorcode/google/chromeos/vpd_decode.c @@ -0,0 +1,89 @@ +/* + * Copyright (c) 2014 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + * + */ +#include <assert.h> +#include "lib_vpd.h" + +int decodeLen( + const int32_t max_len, + const uint8_t *in, + int32_t *length, + int32_t *decoded_len) { + uint8_t more; + int i = 0; + + assert(length); + assert(decoded_len); + + *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; +} + +/* Sequentially decodes type, key, and value. + */ +int decodeVpdString( + const int32_t max_len, + const uint8_t *input_buf, + int32_t *consumed, + VpdDecodeCallback callback, + void *callback_arg) { + int type; + int32_t key_len, value_len; + int32_t decoded_len; + const uint8_t *key, *value; + + /* type */ + if (*consumed >= max_len) + return VPD_FAIL; + + type = input_buf[*consumed]; + switch (type) { + case VPD_TYPE_INFO: + case VPD_TYPE_STRING: + (*consumed)++; + + /* key */ + if (VPD_OK != decodeLen(max_len - *consumed, &input_buf[*consumed], + &key_len, &decoded_len) || + *consumed + decoded_len >= max_len) { + return VPD_FAIL; + } + + *consumed += decoded_len; + key = &input_buf[*consumed]; + *consumed += key_len; + + /* value */ + if (VPD_OK != decodeLen(max_len - *consumed, &input_buf[*consumed], + &value_len, &decoded_len) || + *consumed + decoded_len > max_len) { + return VPD_FAIL; + } + *consumed += decoded_len; + value = &input_buf[*consumed]; + *consumed += value_len; + + if (type == VPD_TYPE_STRING) + return callback(key, key_len, value, value_len, callback_arg); + + return VPD_OK; + + default: + return VPD_FAIL; + break; + } + return VPD_OK; +} |