| /* |
| * Copyright (c) 2016, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * This file implements common methods for manipulating MLE TLVs. |
| */ |
| |
| #include "tlvs.hpp" |
| |
| #include "common/code_utils.hpp" |
| #include "common/debug.hpp" |
| #include "common/message.hpp" |
| |
| namespace ot { |
| |
| uint32_t Tlv::GetSize(void) const |
| { |
| return IsExtended() ? sizeof(ExtendedTlv) + As<ExtendedTlv>(this)->GetLength() : sizeof(Tlv) + GetLength(); |
| } |
| |
| uint8_t *Tlv::GetValue(void) |
| { |
| return reinterpret_cast<uint8_t *>(this) + (IsExtended() ? sizeof(ExtendedTlv) : sizeof(Tlv)); |
| } |
| |
| const uint8_t *Tlv::GetValue(void) const |
| { |
| return reinterpret_cast<const uint8_t *>(this) + (IsExtended() ? sizeof(ExtendedTlv) : sizeof(Tlv)); |
| } |
| |
| Error Tlv::AppendTo(Message &aMessage) const |
| { |
| return aMessage.AppendBytes(this, static_cast<uint16_t>(GetSize())); |
| } |
| |
| Error Tlv::FindTlv(const Message &aMessage, uint8_t aType, uint16_t aMaxSize, Tlv &aTlv) |
| { |
| Error error; |
| uint16_t offset; |
| uint16_t size; |
| |
| SuccessOrExit(error = Find(aMessage, aType, &offset, &size, nullptr)); |
| |
| if (aMaxSize > size) |
| { |
| aMaxSize = size; |
| } |
| |
| aMessage.ReadBytes(offset, &aTlv, aMaxSize); |
| |
| exit: |
| return error; |
| } |
| |
| Error Tlv::FindTlvOffset(const Message &aMessage, uint8_t aType, uint16_t &aOffset) |
| { |
| return Find(aMessage, aType, &aOffset, nullptr, nullptr); |
| } |
| |
| Error Tlv::FindTlvValueOffset(const Message &aMessage, uint8_t aType, uint16_t &aValueOffset, uint16_t &aLength) |
| { |
| Error error; |
| uint16_t offset; |
| uint16_t size; |
| bool isExtendedTlv; |
| |
| SuccessOrExit(error = Find(aMessage, aType, &offset, &size, &isExtendedTlv)); |
| |
| if (!isExtendedTlv) |
| { |
| aValueOffset = offset + sizeof(Tlv); |
| aLength = size - sizeof(Tlv); |
| } |
| else |
| { |
| aValueOffset = offset + sizeof(ExtendedTlv); |
| aLength = size - sizeof(ExtendedTlv); |
| } |
| |
| exit: |
| return error; |
| } |
| |
| Error Tlv::Find(const Message &aMessage, uint8_t aType, uint16_t *aOffset, uint16_t *aSize, bool *aIsExtendedTlv) |
| { |
| // This static method searches within a `aMessage` for a TLV type |
| // `aType` and outputs the TLV offset, size, and whether or not it |
| // is an Extended TLV. |
| // |
| // A `nullptr` pointer can be used for output parameters `aOffset`, |
| // `aSize`, or `aIsExtendedTlv` if the parameter is not required. |
| // |
| // Returns `kErrorNone` when found, otherwise `kErrorNotFound`. |
| |
| Error error = kErrorNotFound; |
| uint16_t offset = aMessage.GetOffset(); |
| uint16_t remainingLen = aMessage.GetLength(); |
| Tlv tlv; |
| uint32_t size; |
| |
| VerifyOrExit(offset <= remainingLen); |
| remainingLen -= offset; |
| |
| while (true) |
| { |
| SuccessOrExit(aMessage.Read(offset, tlv)); |
| |
| if (tlv.mLength != kExtendedLength) |
| { |
| size = tlv.GetSize(); |
| } |
| else |
| { |
| ExtendedTlv extTlv; |
| |
| SuccessOrExit(aMessage.Read(offset, extTlv)); |
| |
| VerifyOrExit(extTlv.GetLength() <= (remainingLen - sizeof(ExtendedTlv))); |
| size = extTlv.GetSize(); |
| } |
| |
| VerifyOrExit(size <= remainingLen); |
| |
| if (tlv.GetType() == aType) |
| { |
| if (aOffset != nullptr) |
| { |
| *aOffset = offset; |
| } |
| |
| if (aSize != nullptr) |
| { |
| *aSize = static_cast<uint16_t>(size); |
| } |
| |
| if (aIsExtendedTlv != nullptr) |
| { |
| *aIsExtendedTlv = (tlv.mLength == kExtendedLength); |
| } |
| |
| error = kErrorNone; |
| ExitNow(); |
| } |
| |
| offset += size; |
| remainingLen -= size; |
| } |
| |
| exit: |
| return error; |
| } |
| |
| template <typename UintType> Error Tlv::ReadUintTlv(const Message &aMessage, uint16_t aOffset, UintType &aValue) |
| { |
| Error error; |
| |
| SuccessOrExit(error = ReadTlv(aMessage, aOffset, &aValue, sizeof(aValue))); |
| aValue = Encoding::BigEndian::HostSwap<UintType>(aValue); |
| |
| exit: |
| return error; |
| } |
| |
| // Explicit instantiations of `ReadUintTlv<>()` |
| template Error Tlv::ReadUintTlv<uint8_t>(const Message &aMessage, uint16_t aOffset, uint8_t &aValue); |
| template Error Tlv::ReadUintTlv<uint16_t>(const Message &aMessage, uint16_t aOffset, uint16_t &aValue); |
| template Error Tlv::ReadUintTlv<uint32_t>(const Message &aMessage, uint16_t aOffset, uint32_t &aValue); |
| |
| Error Tlv::ReadTlv(const Message &aMessage, uint16_t aOffset, void *aValue, uint8_t aMinLength) |
| { |
| Error error = kErrorNone; |
| Tlv tlv; |
| |
| SuccessOrExit(error = aMessage.Read(aOffset, tlv)); |
| VerifyOrExit(!tlv.IsExtended() && (tlv.GetLength() >= aMinLength), error = kErrorParse); |
| VerifyOrExit(tlv.GetSize() + aOffset <= aMessage.GetLength(), error = kErrorParse); |
| |
| aMessage.ReadBytes(aOffset + sizeof(Tlv), aValue, aMinLength); |
| |
| exit: |
| return error; |
| } |
| |
| template <typename UintType> Error Tlv::FindUintTlv(const Message &aMessage, uint8_t aType, UintType &aValue) |
| { |
| Error error = kErrorNone; |
| uint16_t offset; |
| |
| SuccessOrExit(error = FindTlvOffset(aMessage, aType, offset)); |
| error = ReadUintTlv<UintType>(aMessage, offset, aValue); |
| |
| exit: |
| return error; |
| } |
| |
| // Explicit instantiations of `FindUintTlv<>()` |
| template Error Tlv::FindUintTlv<uint8_t>(const Message &aMessage, uint8_t aType, uint8_t &aValue); |
| template Error Tlv::FindUintTlv<uint16_t>(const Message &aMessage, uint8_t aType, uint16_t &aValue); |
| template Error Tlv::FindUintTlv<uint32_t>(const Message &aMessage, uint8_t aType, uint32_t &aValue); |
| |
| Error Tlv::FindTlv(const Message &aMessage, uint8_t aType, void *aValue, uint8_t aLength) |
| { |
| Error error; |
| uint16_t offset; |
| uint16_t length; |
| |
| SuccessOrExit(error = FindTlvValueOffset(aMessage, aType, offset, length)); |
| VerifyOrExit(length >= aLength, error = kErrorParse); |
| aMessage.ReadBytes(offset, aValue, aLength); |
| |
| exit: |
| return error; |
| } |
| |
| template <typename UintType> Error Tlv::AppendUintTlv(Message &aMessage, uint8_t aType, UintType aValue) |
| { |
| UintType value = Encoding::BigEndian::HostSwap<UintType>(aValue); |
| |
| return AppendTlv(aMessage, aType, &value, sizeof(UintType)); |
| } |
| |
| // Explicit instantiations of `AppendUintTlv<>()` |
| template Error Tlv::AppendUintTlv<uint8_t>(Message &aMessage, uint8_t aType, uint8_t aValue); |
| template Error Tlv::AppendUintTlv<uint16_t>(Message &aMessage, uint8_t aType, uint16_t aValue); |
| template Error Tlv::AppendUintTlv<uint32_t>(Message &aMessage, uint8_t aType, uint32_t aValue); |
| |
| Error Tlv::AppendTlv(Message &aMessage, uint8_t aType, const void *aValue, uint8_t aLength) |
| { |
| Error error = kErrorNone; |
| Tlv tlv; |
| |
| OT_ASSERT(aLength <= Tlv::kBaseTlvMaxLength); |
| |
| tlv.SetType(aType); |
| tlv.SetLength(aLength); |
| SuccessOrExit(error = aMessage.Append(tlv)); |
| |
| VerifyOrExit(aLength > 0); |
| error = aMessage.AppendBytes(aValue, aLength); |
| |
| exit: |
| return error; |
| } |
| |
| } // namespace ot |