/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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.
 */
#pragma once

#include <glog/logging.h>
#include <stdint.h>

#include "common/libs/fs/shared_fd.h"

// Requests and constants below are defined in kernel documentation file:
// https://www.kernel.org/doc/Documentation/usb/usbip_protocol.txt
namespace vadb {
namespace usbip {

////////////////////////////////////////////////////////////////////////////////
// COMMANDS
////////////////////////////////////////////////////////////////////////////////

// Command numbers. Commands are valid only once USB device is attached.
enum Command : uint32_t {
  kUsbIpCmdReqSubmit = 1,  // Submit request
  kUsbIpCmdReqUnlink = 2,  // Unlink request
  kUsbIpCmdRepSubmit = 3,  // Submit response
  kUsbIpCmdRepUnlink = 4,  // Unlink response
};

// Direction of data flow.
enum Direction : uint32_t {
  kUsbIpDirectionOut = 0,
  kUsbIpDirectionIn = 1,
};

// Setup structure is explained in great detail here:
// - http://www.beyondlogic.org/usbnutshell/usb6.shtml
// - http://www.usbmadesimple.co.uk/ums_4.htm
struct CmdRequest {
  uint8_t type;
  uint8_t cmd;
  uint16_t value;
  uint16_t index;
  uint16_t length;
} __attribute__((packed));

// CmdHeader precedes any command request or response body.
struct CmdHeader {
  Command command;
  uint32_t seq_num;
  uint16_t bus_num;
  uint16_t dev_num;
  Direction direction;
  uint32_t endpoint;  // valid values: 0-15
} __attribute__((packed));

// Command data for submitting an USB request.
struct CmdReqSubmit {
  uint32_t transfer_flags;
  uint32_t transfer_buffer_length;
  uint32_t start_frame;
  uint32_t number_of_packets;
  uint32_t deadline_interval;
  CmdRequest setup;
} __attribute__((packed));

// Command response for submitting an USB request.
struct CmdRepSubmit {
  uint32_t status;  // 0 = success.
  uint32_t actual_length;
  uint32_t start_frame;
  uint32_t number_of_packets;
  uint32_t error_count;
  CmdRequest setup;
} __attribute__((packed));

// Unlink USB request.
struct CmdReqUnlink {
  uint32_t seq_num;
  uint32_t reserved[6];
} __attribute__((packed));

// Unlink USB response.
struct CmdRepUnlink {
  uint32_t status;
  uint32_t reserved[6];
} __attribute__((packed));

// Diagnostics.
std::ostream& operator<<(std::ostream& out, const CmdHeader& header);
std::ostream& operator<<(std::ostream& out, const CmdReqSubmit& data);
std::ostream& operator<<(std::ostream& out, const CmdRepSubmit& data);
std::ostream& operator<<(std::ostream& out, const CmdReqUnlink& data);
std::ostream& operator<<(std::ostream& out, const CmdRepUnlink& data);

}  // namespace usbip
}  // namespace vadb