src/connectivity/bluetooth/core/bt-host/l2cap/channel_manager.cc - fuchsia - Git at Google

 // Copyright 2017 The Fuchsia 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 "channel_manager.h"

 #include <zircon/assert.h>

 #include "logical_link.h"
 #include "src/connectivity/bluetooth/core/bt-host/common/log.h"
 #include "src/lib/fxl/strings/string_printf.h"

 namespace bt {
 namespace l2cap {

 ChannelManager::ChannelManager(fxl::RefPtr<hci::Transport> hci,
                                async_dispatcher_t* l2cap_dispatcher)
     : hci_(hci), l2cap_dispatcher_(l2cap_dispatcher), weak_ptr_factory_(this) {
   ZX_DEBUG_ASSERT(hci_);
   ZX_DEBUG_ASSERT(l2cap_dispatcher_);

   // TODO(armansito): NET-353
   auto self = weak_ptr_factory_.GetWeakPtr();
   auto acl_handler = [self](auto pkt) {
     if (self) {
       self->OnACLDataReceived(std::move(pkt));
     }
   };

   hci_->acl_data_channel()->SetDataRxHandler(std::move(acl_handler),
                                              l2cap_dispatcher_);
 }

 ChannelManager::~ChannelManager() {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
   hci_->acl_data_channel()->SetDataRxHandler(nullptr, nullptr);

   // Explicitly shut down all links to force associated L2CAP channels to
   // release their strong references.
   for (auto& [handle, link] : ll_map_) {
     link->Close();
   }
 }

 void ChannelManager::RegisterACL(hci::ConnectionHandle handle,
                                  hci::Connection::Role role,
                                  LinkErrorCallback link_error_cb,
                                  SecurityUpgradeCallback security_cb,
                                  async_dispatcher_t* dispatcher) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
   bt_log(TRACE, "l2cap", "register ACL link (handle: %#.4x)", handle);

   auto* ll = RegisterInternal(handle, hci::Connection::LinkType::kACL, role);
   ll->set_error_callback(std::move(link_error_cb), dispatcher);
   ll->set_security_upgrade_callback(std::move(security_cb), dispatcher);
 }

 void ChannelManager::RegisterLE(
     hci::ConnectionHandle handle, hci::Connection::Role role,
     LEConnectionParameterUpdateCallback conn_param_cb,
     LinkErrorCallback link_error_cb, SecurityUpgradeCallback security_cb,
     async_dispatcher_t* dispatcher) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
   bt_log(TRACE, "l2cap", "register LE link (handle: %#.4x)", handle);

   auto* ll = RegisterInternal(handle, hci::Connection::LinkType::kLE, role);
   ll->set_error_callback(std::move(link_error_cb), dispatcher);
   ll->set_security_upgrade_callback(std::move(security_cb), dispatcher);
   ll->le_signaling_channel()->set_conn_param_update_callback(
       std::move(conn_param_cb), dispatcher);
 }

 void ChannelManager::Unregister(hci::ConnectionHandle handle) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   bt_log(TRACE, "l2cap", "unregister link (handle: %#.4x)", handle);

   pending_packets_.erase(handle);
   auto iter = ll_map_.find(handle);
   ZX_DEBUG_ASSERT_MSG(iter != ll_map_.end(),
                       "attempted to remove unknown connection handle: %#.4x",
                       handle);

   // Explicitly shut down the link to force associated L2CAP channels to release
   // their strong references.
   iter->second->Close();
   ll_map_.erase(iter);
 }

 void ChannelManager::AssignLinkSecurityProperties(
     hci::ConnectionHandle handle, sm::SecurityProperties security) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   bt_log(TRACE, "l2cap", "received new security properties (handle: %#.4x)",
          handle);

   auto iter = ll_map_.find(handle);
   if (iter == ll_map_.end()) {
     bt_log(TRACE, "l2cap", "ignoring new security properties on unknown link");
     return;
   }

   iter->second->AssignSecurityProperties(security);
 }

 fbl::RefPtr<Channel> ChannelManager::OpenFixedChannel(
     hci::ConnectionHandle handle, ChannelId channel_id) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   auto iter = ll_map_.find(handle);
   if (iter == ll_map_.end()) {
     bt_log(ERROR, "l2cap",
            "cannot open fixed channel on unknown connection handle: %#.4x",
            handle);
     return nullptr;
   }

   return iter->second->OpenFixedChannel(channel_id);
 }

 void ChannelManager::OpenChannel(hci::ConnectionHandle handle, PSM psm,
                                  ChannelCallback cb,
                                  async_dispatcher_t* dispatcher) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   auto iter = ll_map_.find(handle);
   if (iter == ll_map_.end()) {
     bt_log(ERROR, "l2cap",
            "Cannot open channel on unknown connection handle: %#.4x", handle);
     async::PostTask(dispatcher, [cb = std::move(cb)] { cb(nullptr); });
     return;
   }

   iter->second->OpenChannel(psm, std::move(cb), dispatcher);
 }

 bool ChannelManager::RegisterService(PSM psm, ChannelCallback cb,
                                      async_dispatcher_t* dispatcher) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   // v5.0 Vol 3, Part A, Sec 4.2: PSMs shall be odd and the least significant
   // bit of the most significant byte shall be zero
   if (((psm & 0x0001) != 0x0001) || ((psm & 0x0100) != 0x0000)) {
     return false;
   }

   auto iter = services_.find(psm);
   if (iter != services_.end()) {
     return false;
   }

   // Bind |dispatcher| in callback that forwards the created channel to the
   // service provider.
   ChannelCallback pass_channel =
       [dispatcher, cb = std::move(cb)](fbl::RefPtr<Channel> chan) mutable {
         // Do not transfer ownership of |cb| when passing a channel to L2CAP.
         // |chan| is safe to move because its lifetime spans each invocation.
         async::PostTask(dispatcher, [cb = cb.share(), chan = std::move(chan)] {
           cb(std::move(chan));
         });
       };

   services_[psm] = std::move(pass_channel);
   return true;
 }

 void ChannelManager::UnregisterService(PSM psm) {
   FXL_DCHECK(thread_checker_.IsCreationThreadCurrent());

   services_.erase(psm);
 }

 void ChannelManager::OnACLDataReceived(hci::ACLDataPacketPtr packet) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   // TODO(armansito): Route packets based on channel priority, prioritizing
   // Guaranteed channels over Best Effort. Right now all channels are Best
   // Effort.

   auto handle = packet->connection_handle();

   auto iter = ll_map_.find(handle);
   PendingPacketMap::iterator pp_iter;

   // If a LogicalLink does not exist, we set up a queue for its packets to be
   // delivered when the LogicalLink gets created.
   if (iter == ll_map_.end()) {
     pp_iter = pending_packets_.emplace(handle, LinkedList<hci::ACLDataPacket>())
                   .first;
   } else {
     // A logical link exists. |pp_iter| will be valid only if the drain task has
     // not run yet (see ChannelManager::RegisterInternal()).
     pp_iter = pending_packets_.find(handle);
   }

   if (pp_iter != pending_packets_.end()) {
     pp_iter->second.push_back(std::move(packet));
     bt_log(SPEW, "l2cap", "queued rx packet on handle: %#.4x", handle);
     return;
   }

   iter->second->HandleRxPacket(std::move(packet));
 }

 internal::LogicalLink* ChannelManager::RegisterInternal(
     hci::ConnectionHandle handle, hci::Connection::LinkType ll_type,
     hci::Connection::Role role) {
   ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

   // TODO(armansito): Return nullptr instead of asserting. Callers shouldn't
   // assume this will succeed.
   auto iter = ll_map_.find(handle);
   ZX_DEBUG_ASSERT_MSG(iter == ll_map_.end(),
                       "connection handle re-used! (handle=%#.4x)", handle);

   auto ll = internal::LogicalLink::New(
       handle, ll_type, role, l2cap_dispatcher_, hci_,
       fit::bind_member(this, &ChannelManager::QueryService));

   // Route all pending packets to the link.
   auto pp_iter = pending_packets_.find(handle);
   if (pp_iter != pending_packets_.end()) {
     auto& packets = pp_iter->second;
     while (!packets.is_empty()) {
       ll->HandleRxPacket(packets.pop_front());
     }
     pending_packets_.erase(pp_iter);
   }

   auto* ll_raw = ll.get();
   ll_map_[handle] = std::move(ll);

   return ll_raw;
 }

 ChannelCallback ChannelManager::QueryService(hci::ConnectionHandle handle,
                                              PSM psm) {
   auto iter = services_.find(psm);
   if (iter == services_.end()) {
     return nullptr;
   }

   return iter->second.share();
 }

 }  // namespace l2cap
 }  // namespace bt
	// Copyright 2017 The Fuchsia 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 "channel_manager.h"

	#include <zircon/assert.h>

	#include "logical_link.h"
	#include "src/connectivity/bluetooth/core/bt-host/common/log.h"
	#include "src/lib/fxl/strings/string_printf.h"

	namespace bt {
	namespace l2cap {

	ChannelManager::ChannelManager(fxl::RefPtr<hci::Transport> hci,
	async_dispatcher_t* l2cap_dispatcher)
	: hci_(hci), l2cap_dispatcher_(l2cap_dispatcher), weak_ptr_factory_(this) {
	ZX_DEBUG_ASSERT(hci_);
	ZX_DEBUG_ASSERT(l2cap_dispatcher_);

	// TODO(armansito): NET-353
	auto self = weak_ptr_factory_.GetWeakPtr();
	auto acl_handler = [self](auto pkt) {
	if (self) {
	self->OnACLDataReceived(std::move(pkt));
	}
	};

	hci_->acl_data_channel()->SetDataRxHandler(std::move(acl_handler),
	l2cap_dispatcher_);
	}

	ChannelManager::~ChannelManager() {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
	hci_->acl_data_channel()->SetDataRxHandler(nullptr, nullptr);

	// Explicitly shut down all links to force associated L2CAP channels to
	// release their strong references.
	for (auto& [handle, link] : ll_map_) {
	link->Close();
	}
	}

	void ChannelManager::RegisterACL(hci::ConnectionHandle handle,
	hci::Connection::Role role,
	LinkErrorCallback link_error_cb,
	SecurityUpgradeCallback security_cb,
	async_dispatcher_t* dispatcher) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
	bt_log(TRACE, "l2cap", "register ACL link (handle: %#.4x)", handle);

	auto* ll = RegisterInternal(handle, hci::Connection::LinkType::kACL, role);
	ll->set_error_callback(std::move(link_error_cb), dispatcher);
	ll->set_security_upgrade_callback(std::move(security_cb), dispatcher);
	}

	void ChannelManager::RegisterLE(
	hci::ConnectionHandle handle, hci::Connection::Role role,
	LEConnectionParameterUpdateCallback conn_param_cb,
	LinkErrorCallback link_error_cb, SecurityUpgradeCallback security_cb,
	async_dispatcher_t* dispatcher) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());
	bt_log(TRACE, "l2cap", "register LE link (handle: %#.4x)", handle);

	auto* ll = RegisterInternal(handle, hci::Connection::LinkType::kLE, role);
	ll->set_error_callback(std::move(link_error_cb), dispatcher);
	ll->set_security_upgrade_callback(std::move(security_cb), dispatcher);
	ll->le_signaling_channel()->set_conn_param_update_callback(
	std::move(conn_param_cb), dispatcher);
	}

	void ChannelManager::Unregister(hci::ConnectionHandle handle) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	bt_log(TRACE, "l2cap", "unregister link (handle: %#.4x)", handle);

	pending_packets_.erase(handle);
	auto iter = ll_map_.find(handle);
	ZX_DEBUG_ASSERT_MSG(iter != ll_map_.end(),
	"attempted to remove unknown connection handle: %#.4x",
	handle);

	// Explicitly shut down the link to force associated L2CAP channels to release
	// their strong references.
	iter->second->Close();
	ll_map_.erase(iter);
	}

	void ChannelManager::AssignLinkSecurityProperties(
	hci::ConnectionHandle handle, sm::SecurityProperties security) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	bt_log(TRACE, "l2cap", "received new security properties (handle: %#.4x)",
	handle);

	auto iter = ll_map_.find(handle);
	if (iter == ll_map_.end()) {
	bt_log(TRACE, "l2cap", "ignoring new security properties on unknown link");
	return;
	}

	iter->second->AssignSecurityProperties(security);
	}

	fbl::RefPtr<Channel> ChannelManager::OpenFixedChannel(
	hci::ConnectionHandle handle, ChannelId channel_id) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	auto iter = ll_map_.find(handle);
	if (iter == ll_map_.end()) {
	bt_log(ERROR, "l2cap",
	"cannot open fixed channel on unknown connection handle: %#.4x",
	handle);
	return nullptr;
	}

	return iter->second->OpenFixedChannel(channel_id);
	}

	void ChannelManager::OpenChannel(hci::ConnectionHandle handle, PSM psm,
	ChannelCallback cb,
	async_dispatcher_t* dispatcher) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	auto iter = ll_map_.find(handle);
	if (iter == ll_map_.end()) {
	bt_log(ERROR, "l2cap",
	"Cannot open channel on unknown connection handle: %#.4x", handle);
	async::PostTask(dispatcher, [cb = std::move(cb)] { cb(nullptr); });
	return;
	}

	iter->second->OpenChannel(psm, std::move(cb), dispatcher);
	}

	bool ChannelManager::RegisterService(PSM psm, ChannelCallback cb,
	async_dispatcher_t* dispatcher) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	// v5.0 Vol 3, Part A, Sec 4.2: PSMs shall be odd and the least significant
	// bit of the most significant byte shall be zero
	if (((psm & 0x0001) != 0x0001) \|\| ((psm & 0x0100) != 0x0000)) {
	return false;
	}

	auto iter = services_.find(psm);
	if (iter != services_.end()) {
	return false;
	}

	// Bind \|dispatcher\| in callback that forwards the created channel to the
	// service provider.
	ChannelCallback pass_channel =
	[dispatcher, cb = std::move(cb)](fbl::RefPtr<Channel> chan) mutable {
	// Do not transfer ownership of \|cb\| when passing a channel to L2CAP.
	// \|chan\| is safe to move because its lifetime spans each invocation.
	async::PostTask(dispatcher, [cb = cb.share(), chan = std::move(chan)] {
	cb(std::move(chan));
	});
	};

	services_[psm] = std::move(pass_channel);
	return true;
	}

	void ChannelManager::UnregisterService(PSM psm) {
	FXL_DCHECK(thread_checker_.IsCreationThreadCurrent());

	services_.erase(psm);
	}

	void ChannelManager::OnACLDataReceived(hci::ACLDataPacketPtr packet) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	// TODO(armansito): Route packets based on channel priority, prioritizing
	// Guaranteed channels over Best Effort. Right now all channels are Best
	// Effort.

	auto handle = packet->connection_handle();

	auto iter = ll_map_.find(handle);
	PendingPacketMap::iterator pp_iter;

	// If a LogicalLink does not exist, we set up a queue for its packets to be
	// delivered when the LogicalLink gets created.
	if (iter == ll_map_.end()) {
	pp_iter = pending_packets_.emplace(handle, LinkedList<hci::ACLDataPacket>())
	.first;
	} else {
	// A logical link exists. \|pp_iter\| will be valid only if the drain task has
	// not run yet (see ChannelManager::RegisterInternal()).
	pp_iter = pending_packets_.find(handle);
	}

	if (pp_iter != pending_packets_.end()) {
	pp_iter->second.push_back(std::move(packet));
	bt_log(SPEW, "l2cap", "queued rx packet on handle: %#.4x", handle);
	return;
	}

	iter->second->HandleRxPacket(std::move(packet));
	}

	internal::LogicalLink* ChannelManager::RegisterInternal(
	hci::ConnectionHandle handle, hci::Connection::LinkType ll_type,
	hci::Connection::Role role) {
	ZX_DEBUG_ASSERT(thread_checker_.IsCreationThreadCurrent());

	// TODO(armansito): Return nullptr instead of asserting. Callers shouldn't
	// assume this will succeed.
	auto iter = ll_map_.find(handle);
	ZX_DEBUG_ASSERT_MSG(iter == ll_map_.end(),
	"connection handle re-used! (handle=%#.4x)", handle);

	auto ll = internal::LogicalLink::New(
	handle, ll_type, role, l2cap_dispatcher_, hci_,
	fit::bind_member(this, &ChannelManager::QueryService));

	// Route all pending packets to the link.
	auto pp_iter = pending_packets_.find(handle);
	if (pp_iter != pending_packets_.end()) {
	auto& packets = pp_iter->second;
	while (!packets.is_empty()) {
	ll->HandleRxPacket(packets.pop_front());
	}
	pending_packets_.erase(pp_iter);
	}

	auto* ll_raw = ll.get();
	ll_map_[handle] = std::move(ll);

	return ll_raw;
	}

	ChannelCallback ChannelManager::QueryService(hci::ConnectionHandle handle,
	PSM psm) {
	auto iter = services_.find(psm);
	if (iter == services_.end()) {
	return nullptr;
	}

	return iter->second.share();
	}

	} // namespace l2cap
	} // namespace bt