ostinato/common/emulation.h

56 lines
1.8 KiB
C

/*
Copyright (C) 2016 Srivats P.
This file is part of "Ostinato"
This is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
*/
#ifndef _EMULATION_H
#define _EMULATION_H
#include "emulproto.pb.h"
#include <QtGlobal>
static inline OstProto::DeviceGroup* newDeviceGroup(uint portId)
{
OstProto::DeviceGroup *devGrp = new OstProto::DeviceGroup;
// To ensure that DeviceGroup have a unique key, we assign
// a random mac address upon creation; ideally, it would
// have been good to inherit OstProto::DeviceGroup and define
// a new constructor, but ProtoBuf forbids against inheriting
// generated classes, so we use this helper function instead
//
// Create a mac address as per RFC 4814 Sec 4.2
// (RR & 0xFC):PP:PP:RR:RR:RR
// where RR is a random number, PP:PP is 1-indexed port index
// NOTE: although qrand() return type is a int, the max value
// is RAND_MAX (stdlib.h) which is often 16-bit only, so we
// use two random numbers
quint32 r1 = qrand(), r2 = qrand();
quint64 mac;
mac = quint64(r1 & 0xfc00) << 32
| quint64(portId + 1) << 24
| quint64((r1 & 0xff) << 16 | (r2 & 0xffff));
devGrp->MutableExtension(OstEmul::mac)->set_address(mac);
return devGrp;
}
#endif