| // Copyright 2018 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. |
| |
| #ifndef SRC_DEVICES_BIN_DRIVER_HOST_FIDL_TXN_H_ |
| #define SRC_DEVICES_BIN_DRIVER_HOST_FIDL_TXN_H_ |
| |
| #include <lib/fidl/epitaph.h> |
| #include <lib/fidl/llcpp/transaction.h> |
| #include <lib/zx/channel.h> |
| #include <zircon/fidl.h> |
| |
| // Manages state of a FIDL transaction for the DevMgr so we can reply to the correct message. |
| // DevmgrFidlTxn must not outlive the channel it is given |
| class DevmgrFidlTxn : public fidl::Transaction { |
| public: |
| DevmgrFidlTxn(zx::unowned_channel channel, uint32_t txid) |
| : channel_(channel), txid_(txid), status_called_(false) {} |
| DevmgrFidlTxn(const zx::channel& channel, uint32_t txid) |
| : channel_(channel), txid_(txid), status_called_(false) {} |
| |
| ~DevmgrFidlTxn() { |
| ZX_ASSERT_MSG(status_called_, |
| "DevmgrFidlTxn must have it's Status() method used. \ |
| This provides Devmgr with the correct status value.\n"); |
| } |
| |
| void Reply(fidl::Message message) override { |
| ZX_ASSERT_MSG(txid_, "DevmgrFidlTxn must have its transaction id set.\n"); |
| const fidl_msg_t msg{ |
| .bytes = message.bytes().data(), |
| .handles = message.handles().data(), |
| .num_bytes = static_cast<uint32_t>(message.bytes().size()), |
| .num_handles = static_cast<uint32_t>(message.handles().size()), |
| }; |
| |
| auto hdr = static_cast<fidl_message_header_t*>(msg.bytes); |
| hdr->txid = txid_; |
| status_ = channel_->write(0, msg.bytes, msg.num_bytes, msg.handles, msg.num_handles); |
| |
| // We have now transferred ownership of the message's handles over the channel. |
| message.ClearHandlesUnsafe(); |
| } |
| |
| void Close(zx_status_t close_status) override { |
| // no-op for devmgr |
| } |
| |
| std::unique_ptr<Transaction> TakeOwnership() override { |
| // status isn't called, but not relevant in a Async context |
| status_called_ = true; |
| return std::make_unique<DevmgrFidlTxn>(std::move(*this)); |
| } |
| |
| zx_status_t Status() __WARN_UNUSED_RESULT { |
| status_called_ = true; |
| return status_; |
| } |
| |
| private: |
| // Reply channel |
| const zx::unowned_channel channel_; |
| |
| // Transaction id of the message we're replying to |
| const uint32_t txid_; |
| |
| // Has the Status method been called? |
| bool status_called_; |
| |
| // Status is OK by default since not all functions call Reply |
| zx_status_t status_ = ZX_OK; |
| }; |
| |
| // Manages state of a FIDL transaction so we can reply to the correct message. |
| // FidlTxn must not outlive the channel it is given |
| class FidlTxn { |
| public: |
| FidlTxn(zx::unowned_channel channel, uint32_t txid) : channel_(channel), txid_(txid) {} |
| FidlTxn(const zx::channel& channel, uint32_t txid) : channel_(channel), txid_(txid) {} |
| |
| FidlTxn& operator=(const FidlTxn&) = delete; |
| FidlTxn(const FidlTxn&) = delete; |
| |
| FidlTxn& operator=(FidlTxn&&) = delete; |
| FidlTxn(FidlTxn&&) = delete; |
| |
| zx_status_t Reply(const fidl_msg_t* msg) { |
| auto hdr = static_cast<fidl_message_header_t*>(msg->bytes); |
| hdr->txid = txid_; |
| return channel_->write(0, msg->bytes, msg->num_bytes, msg->handles, msg->num_handles); |
| } |
| |
| static zx_status_t FidlReply(fidl_txn_t* reply, const fidl_msg_t* msg) { |
| static_assert(offsetof(FidlTxn, txn_) == 0); |
| return reinterpret_cast<FidlTxn*>(reply)->Reply(msg); |
| } |
| |
| fidl_txn_t* fidl_txn() { return &txn_; } |
| |
| private: |
| // Due to the implementation of FidlReply, it is important that this be the |
| // first member variable. |
| fidl_txn_t txn_ = {.reply = FidlTxn::FidlReply}; |
| |
| // Reply channel |
| const zx::unowned_channel channel_; |
| |
| // Transaction id of the message we're replying to |
| const uint32_t txid_; |
| }; |
| |
| #endif // SRC_DEVICES_BIN_DRIVER_HOST_FIDL_TXN_H_ |