WiFlasher/libESTA/acn/sdt.h

/*
  sdt.h

  Copyright (c) 2020 Kevin Matz (kevin.matz@gmail.com)

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
#pragma once

#include <cstdint>
#include <list>
#include <memory>
#include <unordered_map>
#include "component.h"
#include "pdu.h"
#include "sdt-udp.h"  // EPI 18

// ANSI E1.17- 2015, Architecture for Control Networks–
//  Session Data Transport Protocol
namespace ACN {
namespace SDT {

// 3.1 Session Identity
struct SessionId {
  UUID::uuid  cid;      // the component ID (CID) of the session leader
  uint16_t    number;   // the session number the leader has assigned
  uint32_t    protocol; // the ID of the protocol carried by the session
  bool operator== (const SessionId &) const;
};

// 3.3 Sequenced Channels
// Sequenced channels transport three categories of traffic:
enum Direction {
  internal,   // SDT internal traffic
  downstream, // Session downstream traffic
  upstream    // Session upstream traffic
};

// 3.5.1.1 Member Identifiers
using MID = uint16_t;

// 4.4.1.2 Channel Parameter Block
struct params_t {
  uint8_t Expiry;       // number of seconds without traffic before leaving
  struct {
    uint8_t NAK_Outbound : 1;  // NAK to channel (1) or destination address (0)
    uint8_t zero : 7;
  };
  uint16_t NAKholdoff;  // calculation of a standoff time for sending NAKs
  uint16_t NAKmodulus;  // calculation of a standoff time for sending NAKs
  uint16_t NAKmaxwait;  // maximum milliseconds to wait before sending a NAK.
};

// 4.4.1 Join
struct join_data_t : PDU::pdu_data {
  MID      mid;
  uint16_t number;
  uint16_t reciprocal;
  uint32_t sequence;
  uint32_t reliable;
  UDP::address_t destination;
  params_t parameters;
  uint32_t expiry;
};

// 4.4.2 Join Accept
struct join_accept_data_t : PDU::pdu_data {
  UUID::uuid leader;
  uint16_t   number;
  MID        mid;
  uint32_t   reliable;
  uint16_t   reciprocal;
};

// 4.4.3 Join Refuse
struct join_refuse_data_t : PDU::pdu_data {
  UUID::uuid leader;
  uint16_t   number;
  MID        mid;
  uint32_t   reliable;
  uint8_t    code;
};

// 4.4.4 Leaving
struct leaving_data_t : PDU::pdu_data {
  UUID::uuid leader;
  uint16_t   number;
  MID        mid;
  uint32_t   reliable;
  uint8_t    code;
};

// 4.4.5 NAK
struct nak_data_t : PDU::pdu_data {
  UUID::uuid leader;
  uint16_t   number;
  MID        mid;
  uint32_t   reliable;
  uint32_t   missed_first;
  uint32_t   missed_last;
};

// 4.4.6 Reliable Wrapper and Unreliable Wrapper
struct wrapper_data_t : PDU::pdu_data {
  uint16_t number;
  uint32_t sequence;
  uint32_t reliable;
  uint32_t oldest;
  MID      ack_range_begin;
  MID      ack_range_end;
  uint16_t MAK_threshold;
  // SDT client block
};

// 4.4.7 SDT Client Block
struct client_pdu_header_t : PDU::pdu_header {
  uint32_t protocol;
  uint16_t association;
  client_pdu_header_t(PDU::Stream);
};

// Client Block PDU
class ClientPdu
  : public PDU::Pdu
{
public:
  ClientPdu(PDU::Stream);
};

// 4.4.8 Get Sessions
struct get_sessions_data_t : PDU::pdu_data {
  UUID::uuid cid;
};


// 4.4.9.1 Channel Owner Info Block
struct channel_info_block_t {
  MID        mid;
  UUID::uuid owner;
  uint16_t   number;
  UDP::address_t destination;
  UDP::address_t source;
  uint16_t   reciprocal;
  uint16_t   count;
  std::list<uint32_t> protocols;
};

// 4.4.9 Sessions
struct sessions_data_t : PDU::pdu_data {
  std::list<channel_info_block_t> list;
};

// 4.5.1 ACK
struct ack_data_t : PDU::pdu_data {
  uint32_t reliable;
};

// 4.5.2 Channel Params
struct channel_params_data_t : PDU::pdu_data {
  params_t parameters;
  UDP::address_t address;
  uint8_t  expiry;
};

// 4.5.3 Connect
// 4.5.4 Connect Accept
// 4.5.6 Disconnect
struct connect_data_t : PDU::pdu_data {
  uint32_t protocol;
};

// 4.5.5 Connect Refuse
// 4.5.7 Disconnecting
struct connect_refuse_data_t : PDU::pdu_data {
  uint32_t protocol;
  uint8_t  code;
};


// 7.1 Protocol Code
static const uint32_t SDT_PROTOCOL_ID = 1; // PDU protocol value

// 7.2 PDU Vector Codes
enum sdt_vector_t {
  REL_WRAP       =  1,
  UNREL_WRAP     =  2,
  CHANNEL_PARAMS =  3,
  JOIN           =  4,
  JOIN_REFUSE    =  5,
  JOIN_ACCEPT    =  6,
  LEAVE          =  7,
  LEAVING        =  8,
  CONNECT        =  9,
  CONNECT_ACCEPT = 10,
  CONNECT_REFUSE = 11,
  DISCONNECT     = 12,
  DISCONNECTING  = 13,
  ACK            = 14,
  NAK            = 15,
  GET_SESSIONS   = 16,
  SESSIONS       = 17,
};

// 7.4 Other Symbolic Parameters

// Table 6: Reason Codes
enum reason_code_t {
  NONSPECIFIC                 = 1,  // Non-specific, non-SDT reason.
  ILLEGAL_PARAMETERS          = 2,  // Illegal channel parameters.
  LOW_RESOURCES               = 3,  // Insufficient resources.
  ALREADY_MEMBER              = 4,  // Multiple MIDs for single component.
  BAD_ADDRESS_TYPE            = 5,  // Unrecognized transport address type.
  NO_RECIPROCAL_CHANNEL       = 6,  // No upstream channel and can’t create one
  CHANNEL_EXPIRED             = 7,  // Channel has expired.
  LOST_SEQUENCE               = 8,  // Unrecoverable packets missed.
  SATURATED                   = 9,  // Can’t keep up, processor saturation.
  TRANSPORT_ADDRESS_CHANGING  = 10, // (e.g., IP number lease expired).
  ASKED_TO_LEAVE              = 11, // Asked to leave the channel.
  NO_RECIPIENT                = 12, // Component does not support protocol ID.
  ONLY_UNICAST_SUPPORTED      = 13  // Only unicast channels are supported
};

// Table 7: Address Specification Types
enum ip_addr_spec_t {
  SDT_ADDR_NULL = 0,  // Address is not present (0 octets).
  SDT_ADDR_IPV4 = 1,  // Address specified is in IP v4 format
  SDT_ADDR_IPV6 = 2   // Address specified is in IP v6 format
};

// PDU type for this protocol
class Pdu
  : public PDU::Pdu
{
public:
  Pdu(PDU::Stream);
};


// Sequenced channels are unidirectional communication channels (unicast or
// multicast) from an owner component to one or more member components.
class Channel {
public:
  Channel(std::shared_ptr<Component>, Direction);
  ~Channel();

private:
  std::shared_ptr<Component> owner_;
  Direction direction_ = internal;
};


// A session has a single leader and zero or more session members. The leader
// communicates to members using the downstream address. Members respond to the
// leader on the upstream address. A unique session identifier identifies a
// session.
class Session {
public:
  Session();
  ~Session();

  SessionId id();

  // 4.4 SDT Base Layer Messages (non ad-hoc)
  void join_accept() {};
  void join_refuse() {};
  void leaving() {};
  void nak() {};
  void reliable_wrapper() {};
  void unreliable_wrapper() {};

  // 4.5 SDT Wrapped Messages
  void ack();
  void channel_params();
  void leave();
  void connect();
  void connect_accept();
  void connect_refuse();
  void disconnect();
  void disconnecting();

protected:
  std::shared_ptr<ACN::Component> leader;
  std::shared_ptr<Channel>        downstream;
  std::unordered_map<MID, std::shared_ptr<Channel>> upstream;

private:
  uint16_t number_;
  uint32_t protocol_;
  MID next_id_ = 1;
};

} // SDT
} // ACN