blob: 3971864bb7e06e259817fa16106fba8c848e77ee [file] [log] [blame]
/*
*
* Copyright (c) 2020-2021 Project CHIP Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* This file implements the ExchangeManager class.
*
*/
#include <cstring>
#include <inttypes.h>
#include <stddef.h>
#include <crypto/RandUtils.h>
#include <lib/core/CHIPCore.h>
#include <lib/core/CHIPEncoding.h>
#include <lib/support/CHIPFaultInjection.h>
#include <lib/support/CodeUtils.h>
#include <lib/support/logging/CHIPLogging.h>
#include <messaging/ExchangeContext.h>
#include <messaging/ExchangeMgr.h>
#include <protocols/Protocols.h>
using namespace chip::Encoding;
using namespace chip::Inet;
using namespace chip::System;
namespace chip {
namespace Messaging {
/**
* Constructor for the ExchangeManager class.
* It sets the state to kState_NotInitialized.
*
* @note
* The class must be initialized via ExchangeManager::Init()
* prior to use.
*
*/
ExchangeManager::ExchangeManager() : mReliableMessageMgr(mContextPool)
{
mState = State::kState_NotInitialized;
}
CHIP_ERROR ExchangeManager::Init(SessionManager * sessionManager)
{
CHIP_ERROR err = CHIP_NO_ERROR;
VerifyOrReturnError(mState == State::kState_NotInitialized, err = CHIP_ERROR_INCORRECT_STATE);
mSessionManager = sessionManager;
mNextExchangeId = chip::Crypto::GetRandU16();
mNextKeyId = 0;
for (auto & handler : UMHandlerPool)
{
// Mark all handlers as unallocated. This handles both initial
// initialization and the case when the consumer shuts us down and
// then re-initializes without removing registered handlers.
handler.Reset();
}
sessionManager->SetMessageDelegate(this);
mReliableMessageMgr.Init(sessionManager->SystemLayer());
mState = State::kState_Initialized;
return err;
}
void ExchangeManager::Shutdown()
{
VerifyOrReturn(mState != State::kState_NotInitialized);
mReliableMessageMgr.Shutdown();
if (mSessionManager != nullptr)
{
mSessionManager->SetMessageDelegate(nullptr);
mSessionManager = nullptr;
}
mState = State::kState_NotInitialized;
}
ExchangeContext * ExchangeManager::NewContext(const SessionHandle & session, ExchangeDelegate * delegate, bool isInitiator)
{
if (!session->IsActiveSession())
{
// Disallow creating exchange on an inactive session
ChipLogError(ExchangeManager, "NewContext failed: session inactive");
return nullptr;
}
return mContextPool.CreateObject(this, mNextExchangeId++, session, isInitiator, delegate);
}
CHIP_ERROR ExchangeManager::RegisterUnsolicitedMessageHandlerForProtocol(Protocols::Id protocolId,
UnsolicitedMessageHandler * handler)
{
return RegisterUMH(protocolId, kAnyMessageType, handler);
}
CHIP_ERROR ExchangeManager::RegisterUnsolicitedMessageHandlerForType(Protocols::Id protocolId, uint8_t msgType,
UnsolicitedMessageHandler * handler)
{
return RegisterUMH(protocolId, static_cast<int16_t>(msgType), handler);
}
CHIP_ERROR ExchangeManager::UnregisterUnsolicitedMessageHandlerForProtocol(Protocols::Id protocolId)
{
return UnregisterUMH(protocolId, kAnyMessageType);
}
CHIP_ERROR ExchangeManager::UnregisterUnsolicitedMessageHandlerForType(Protocols::Id protocolId, uint8_t msgType)
{
return UnregisterUMH(protocolId, static_cast<int16_t>(msgType));
}
CHIP_ERROR ExchangeManager::RegisterUMH(Protocols::Id protocolId, int16_t msgType, UnsolicitedMessageHandler * handler)
{
UnsolicitedMessageHandlerSlot * selected = nullptr;
for (auto & umh : UMHandlerPool)
{
if (!umh.IsInUse())
{
if (selected == nullptr)
selected = &umh;
}
else if (umh.Matches(protocolId, msgType))
{
umh.Handler = handler;
return CHIP_NO_ERROR;
}
}
if (selected == nullptr)
return CHIP_ERROR_TOO_MANY_UNSOLICITED_MESSAGE_HANDLERS;
selected->Handler = handler;
selected->ProtocolId = protocolId;
selected->MessageType = msgType;
SYSTEM_STATS_INCREMENT(chip::System::Stats::kExchangeMgr_NumUMHandlers);
return CHIP_NO_ERROR;
}
CHIP_ERROR ExchangeManager::UnregisterUMH(Protocols::Id protocolId, int16_t msgType)
{
for (auto & umh : UMHandlerPool)
{
if (umh.IsInUse() && umh.Matches(protocolId, msgType))
{
umh.Reset();
SYSTEM_STATS_DECREMENT(chip::System::Stats::kExchangeMgr_NumUMHandlers);
return CHIP_NO_ERROR;
}
}
return CHIP_ERROR_NO_UNSOLICITED_MESSAGE_HANDLER;
}
void ExchangeManager::OnMessageReceived(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader,
const SessionHandle & session, DuplicateMessage isDuplicate,
System::PacketBufferHandle && msgBuf)
{
UnsolicitedMessageHandlerSlot * matchingUMH = nullptr;
#if CHIP_PROGRESS_LOGGING
auto * protocolName = Protocols::GetProtocolName(payloadHeader.GetProtocolID());
auto * msgTypeName = Protocols::GetMessageTypeName(payloadHeader.GetProtocolID(), payloadHeader.GetMessageType());
//
// 32-bit value maximum = 10 chars + text preamble (6) + trailer (1) + null (1) + 2 buffer = 20
//
char ackBuf[20];
ackBuf[0] = '\0';
if (payloadHeader.GetAckMessageCounter().HasValue())
{
snprintf(ackBuf, sizeof(ackBuf), " (Ack:" ChipLogFormatMessageCounter ")", payloadHeader.GetAckMessageCounter().Value());
}
CompressedFabricId compressedFabricId = 0;
if (session->IsSecureSession() && mSessionManager->GetFabricTable() != nullptr)
{
auto fabricInfo = mSessionManager->GetFabricTable()->FindFabricWithIndex(session->AsSecureSession()->GetFabricIndex());
if (fabricInfo)
{
compressedFabricId = fabricInfo->GetCompressedFabricId();
}
}
//
// Legend that can be used to decode this log line can be found in README.md
//
ChipLogProgress(ExchangeManager,
">>> [E:" ChipLogFormatExchangeId " S:%u M:" ChipLogFormatMessageCounter
"%s] (%s) Msg RX from %u:" ChipLogFormatX64 " [%04X] --- Type %04x:%02x (%s:%s)",
ChipLogValueExchangeIdFromReceivedHeader(payloadHeader), session->SessionIdForLogging(),
packetHeader.GetMessageCounter(), ackBuf, Transport::GetSessionTypeString(session), session->GetFabricIndex(),
ChipLogValueX64(session->GetPeer().GetNodeId()), static_cast<uint16_t>(compressedFabricId),
payloadHeader.GetProtocolID().GetProtocolId(), payloadHeader.GetMessageType(), protocolName, msgTypeName);
#endif
MessageFlags msgFlags;
if (isDuplicate == DuplicateMessage::Yes)
{
msgFlags.Set(MessageFlagValues::kDuplicateMessage);
}
// Skip retrieval of exchange for group message since no exchange is stored
// for group msg (optimization)
if (!packetHeader.IsGroupSession())
{
// Search for an existing exchange that the message applies to. If a match is found...
bool found = false;
mContextPool.ForEachActiveObject([&](auto * ec) {
if (ec->MatchExchange(session, packetHeader, payloadHeader))
{
ChipLogDetail(ExchangeManager, "Found matching exchange: " ChipLogFormatExchange ", Delegate: %p",
ChipLogValueExchange(ec), ec->GetDelegate());
// Matched ExchangeContext; send to message handler.
ec->HandleMessage(packetHeader.GetMessageCounter(), payloadHeader, msgFlags, std::move(msgBuf));
found = true;
return Loop::Break;
}
return Loop::Continue;
});
if (found)
{
return;
}
}
else
{
ChipLogProgress(ExchangeManager, "Received Groupcast Message with GroupId 0x%04X (%d)",
packetHeader.GetDestinationGroupId().Value(), packetHeader.GetDestinationGroupId().Value());
}
// Do not handle messages that don't match an existing exchange on an
// inactive session, since we should not be creating new exchanges there.
if (!session->IsActiveSession())
{
ChipLogProgress(ExchangeManager, "Dropping message on inactive session that does not match an existing exchange");
return;
}
// If it's not a duplicate message, search for an unsolicited message handler if it is marked as being sent by an initiator.
// Since we didn't find an existing exchange that matches the message, it must be an unsolicited message. However all
// unsolicited messages must be marked as being from an initiator.
if (!msgFlags.Has(MessageFlagValues::kDuplicateMessage) && payloadHeader.IsInitiator())
{
// Search for an unsolicited message handler that can handle the message. Prefer handlers that can explicitly
// handle the message type over handlers that handle all messages for a profile.
matchingUMH = nullptr;
for (auto & umh : UMHandlerPool)
{
if (umh.IsInUse() && payloadHeader.HasProtocol(umh.ProtocolId))
{
if (umh.MessageType == payloadHeader.GetMessageType())
{
matchingUMH = &umh;
break;
}
if (umh.MessageType == kAnyMessageType)
matchingUMH = &umh;
}
}
}
// Discard the message if it isn't marked as being sent by an initiator and the message does not need to send
// an ack to the peer.
else if (!payloadHeader.NeedsAck())
{
// We can easily get standalone acks here: any time we fail to get a
// timely ack for the last message in an exchange and retransmit it,
// then get acks for both the message and the retransmit, the second ack
// will end up in this block. That's not really an error condition, so
// there is no need to log an error in that case.
if (!payloadHeader.HasMessageType(Protocols::SecureChannel::MsgType::StandaloneAck))
{
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT,
CHIP_ERROR_UNSOLICITED_MSG_NO_ORIGINATOR.Format());
}
return;
}
// If we found a handler, create an exchange to handle the message.
if (matchingUMH != nullptr)
{
ExchangeDelegate * delegate = nullptr;
// Fetch delegate from the handler
CHIP_ERROR err = matchingUMH->Handler->OnUnsolicitedMessageReceived(payloadHeader, delegate);
if (err != CHIP_NO_ERROR)
{
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT, err.Format());
SendStandaloneAckIfNeeded(packetHeader, payloadHeader, session, msgFlags, std::move(msgBuf));
return;
}
ExchangeContext * ec = mContextPool.CreateObject(this, payloadHeader.GetExchangeID(), session, false, delegate);
if (ec == nullptr)
{
if (delegate != nullptr)
{
matchingUMH->Handler->OnExchangeCreationFailed(delegate);
}
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT, CHIP_ERROR_NO_MEMORY.Format());
// No resource for creating new exchange, SendStandaloneAckIfNeeded probably also fails, so do not try it here
return;
}
ChipLogDetail(ExchangeManager, "Handling via exchange: " ChipLogFormatExchange ", Delegate: %p", ChipLogValueExchange(ec),
ec->GetDelegate());
if (ec->IsEncryptionRequired() != packetHeader.IsEncrypted())
{
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT,
CHIP_ERROR_INVALID_MESSAGE_TYPE.Format());
ec->Close();
SendStandaloneAckIfNeeded(packetHeader, payloadHeader, session, msgFlags, std::move(msgBuf));
return;
}
err = ec->HandleMessage(packetHeader.GetMessageCounter(), payloadHeader, msgFlags, std::move(msgBuf));
if (err != CHIP_NO_ERROR)
{
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT, err.Format());
}
return;
}
SendStandaloneAckIfNeeded(packetHeader, payloadHeader, session, msgFlags, std::move(msgBuf));
}
void ExchangeManager::SendStandaloneAckIfNeeded(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader,
const SessionHandle & session, MessageFlags msgFlags,
System::PacketBufferHandle && msgBuf)
{
// If using the MRP protocol and we need to send a StandaloneAck, create an EphemeralExchange to send
// the StandaloneAck.
if (!session->AllowsMRP() || !payloadHeader.NeedsAck())
return;
// If rcvd msg is from initiator then this exchange is created as not Initiator.
// If rcvd msg is not from initiator then this exchange is created as Initiator.
// Create a EphemeralExchange to generate a StandaloneAck
ExchangeContext * ec = mContextPool.CreateObject(this, payloadHeader.GetExchangeID(), session, !payloadHeader.IsInitiator(),
nullptr, true /* IsEphemeralExchange */);
if (ec == nullptr)
{
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT, CHIP_ERROR_NO_MEMORY.Format());
return;
}
ChipLogDetail(ExchangeManager, "Generating StandaloneAck via exchange: " ChipLogFormatExchange, ChipLogValueExchange(ec));
// No need to verify packet encryption type, the EphemeralExchange can handle both secure and insecure messages.
CHIP_ERROR err = ec->HandleMessage(packetHeader.GetMessageCounter(), payloadHeader, msgFlags, std::move(msgBuf));
if (err != CHIP_NO_ERROR)
{
// Using same error message for all errors to reduce code size.
ChipLogError(ExchangeManager, "OnMessageReceived failed, err = %" CHIP_ERROR_FORMAT, err.Format());
}
// The exchange should be closed inside HandleMessage function. So don't bother close it here.
}
void ExchangeManager::CloseAllContextsForDelegate(const ExchangeDelegate * delegate)
{
mContextPool.ForEachActiveObject([&](auto * ec) {
if (ec->GetDelegate() == delegate)
{
// Make sure to null out the delegate before closing the context, so
// we don't notify the delegate that the context is closing. We
// have to do this, because the delegate might be partially
// destroyed by this point.
ec->SetDelegate(nullptr);
ec->Close();
}
return Loop::Continue;
});
}
} // namespace Messaging
} // namespace chip