1 // Copyright 2024 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 15 #pragma once 16 17 #include "pw_bluetooth/l2cap_frames.emb.h" 18 #include "pw_bluetooth_proxy/basic_l2cap_channel.h" 19 20 namespace pw::bluetooth::proxy { 21 22 // Interface for L2CAP signaling channels, which can be either ACL-U signaling 23 // channels or LE-U signaling channels. 24 class L2capSignalingChannel : public BasicL2capChannel { 25 public: 26 explicit L2capSignalingChannel(L2capChannelManager& l2cap_channel_manager, 27 uint16_t connection_handle, 28 uint16_t fixed_cid); 29 30 L2capSignalingChannel& operator=(L2capSignalingChannel&& other); 31 32 // Process the payload of a CFrame. Implementations should return true if the 33 // CFrame was consumed by the channel. Otherwise, return false and the PDU 34 // containing this CFrame will be forwarded by `ProxyHost` on to the Bluetooth 35 // host. 36 virtual bool OnCFramePayload(pw::span<const uint8_t> cframe_payload) = 0; 37 38 // Process an individual signaling command. 39 // 40 // Returns false if the command is not processed, either because it is not 41 // directed to a channel managed by `L2capChannelManager` or because we do 42 // not listen for that type of command. 43 bool HandleL2capSignalingCommand(emboss::L2capSignalingCommandView cmd); 44 45 // Handle L2CAP_FLOW_CONTROL_CREDIT_IND. 46 // 47 // Returns false if the packet is invalid or not directed to a channel managed 48 // by `L2capChannelManager`. 49 bool HandleFlowControlCreditInd(emboss::L2capFlowControlCreditIndView cmd); 50 51 // Send L2CAP_FLOW_CONTROL_CREDIT_IND to indicate local endpoint `cid` is 52 // capable of receiving a number of additional K-frames (`credits`). 53 // 54 // Returns PW_STATUS_INVALID_ARGUMENT if CID is invalid. 55 // Returns PW_STATUS_UNAVAILABLE if send could not be queued. 56 Status SendFlowControlCreditInd(uint16_t cid, uint16_t credits); 57 58 protected: 59 // Process a C-frame. 60 // 61 // Returns false if the C-frame is to be forwarded on to the Bluetooth host, 62 // either because the command is not directed towards a channel managed by 63 // `L2capChannelManager` or because the C-frame is invalid and should be 64 // handled by the Bluetooth host. 65 bool HandlePduFromController(pw::span<uint8_t> cframe) override; 66 67 bool HandlePduFromHost(pw::span<uint8_t> cframe) override; 68 69 L2capChannelManager& l2cap_channel_manager_; 70 }; 71 72 } // namespace pw::bluetooth::proxy 73