File content as of revision 0:580aba13d1a1:

/*
The MIT License
Copyright (c) 2019 Lehrstuhl Informatik 11 - RWTH Aachen University
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

This file is part of embeddedRTPS.

Author: i11 - Embedded Software, RWTH Aachen University
*/

#ifndef RTPS_UDP_UTILS_H
#define RTPS_UDP_UTILS_H

#include "rtps/config.h"

namespace rtps {
namespace {
const uint16_t PB = 7400; // Port Base Number
const uint16_t DG = 250;  // DomainId Gain
const uint16_t PG = 2;    // ParticipantId Gain
// Additional Offsets
const uint16_t D0 = 0;  // Builtin multicast
const uint16_t D1 = 10; // Builtin unicast
const uint16_t D2 = 1;  // User multicast
const uint16_t D3 = 11; // User unicast
} // namespace

constexpr ip4_addr transformIP4ToU32(uint8_t MSB, uint8_t p2, uint8_t p1,
                                     uint8_t LSB) {
  return {((uint32_t)(LSB << 24)) | ((uint32_t)(p1 << 16)) |
          ((uint32_t)(p2 << 8)) | MSB};
}

constexpr Ip4Port_t getBuiltInUnicastPort(ParticipantId_t participantId) {
  return PB + DG * Config::DOMAIN_ID + D1 + PG * participantId;
}

constexpr Ip4Port_t getBuiltInMulticastPort() {
  return PB + DG * Config::DOMAIN_ID + D0;
}

constexpr Ip4Port_t getUserUnicastPort(ParticipantId_t participantId) {
  return PB + DG * Config::DOMAIN_ID + D3 + PG * participantId;
}

constexpr Ip4Port_t getUserMulticastPort() {
  return PB + DG * Config::DOMAIN_ID + D2;
}

constexpr bool isUserPort(Ip4Port_t port) { return (port & 1) == 1; }

inline bool isMultiCastPort(Ip4Port_t port) {
  const auto idWithoutBase = port - PB - DG * Config::DOMAIN_ID;
  return idWithoutBase == D0 || idWithoutBase == D2;
}

inline ParticipantId_t getParticipantIdFromUnicastPort(Ip4Port_t port,
                                                       bool isUserPort) {
  // if(isMultiCastPort(port)){ // TODO remove?
  //    return PARTICIPANT_ID_INVALID;
  //}

  const auto basePart = PB + DG * Config::DOMAIN_ID;
  ParticipantId_t participantPart = port - basePart;

  uint16_t offset = 0;
  if (isUserPort) {
    offset = D3;
  } else {
    offset = D1;
  }

  participantPart -= offset;

  auto id = static_cast<ParticipantId_t>(participantPart / PG);
  if (id * PG + basePart + offset == port) {
    return id;
  } else {
    return PARTICIPANT_ID_INVALID;
  }
}

} // namespace rtps

#endif // RTPS_UDP_H