AuroraRuntime/Source/IO/Net/AuNetSocketServer.Unix.cpp

/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: AuNetSocketServer.Linux.cpp
    Date: 2022-8-26
    Author: Reece
***/
#include "Networking.hpp"
#include "AuNetSocketServer.hpp"
#include "AuNetError.hpp"
#include "AuNetEndpoint.hpp"

#if !defined(SOCK_CLOEXEC)
    #define SOCK_CLOEXEC 0
#endif

namespace Aurora::IO::Net
{
    SocketServerImpl::SocketServerImpl(NetInterface *pInterface,
                                       NetWorker *pWorker,
                                       const AuSPtr<ISocketServerDriver> &pDriver,
                                       const AuSPtr<ISocketDriverFactory> &pSocketDriverFactory,
                                       AuUInt32 uMaxConnections,
                                       AuUInt32 uDefaultInputStreamSize,
                                       bool bMultiThreaded) :
        SocketServer(pInterface,
                     pWorker,
                     pDriver,
                     pSocketDriverFactory,
                     uMaxConnections,
                     uDefaultInputStreamSize,
                     bMultiThreaded),
        Socket(pInterface,
               pWorker,
               AuSPtr<ISocketDriver>{},
               -1),
        acceptOperation_(pInterface, this),
        pSocketDriverFactory_(pSocketDriverFactory)
    {
    }

    void SocketServerImpl::DoNonblockingReadTick()
    {
        if (!this->acceptOperation_.DoTick())
        {
            SysPushErrorIO("Accept tick failed");
            this->SendFinalize();
        }
    }

    bool SocketServerImpl::InitSocket(const NetEndpoint &localAddress)
    {
        this->pSocketDriver_ = AuDynamicCast<SocketServerImpl>(this->SharedFromThis());
        this->localEndpoint_ = localAddress;

        if (!this->SendPreestablish())
        {
            SysPushErrorIO("Preestablish drop");
            return false;
        }

        bool bMakeCloseExec { !bool(SOCK_CLOEXEC) };
        this->osHandle_ = ::socket(
            IPToDomain(localAddress),
            TransportToPlatformType(localAddress) | SOCK_CLOEXEC,
            0
        );

        if (this->osHandle_ == -1)
        {
            this->osHandle_ = ::socket(
                IPToDomain(localAddress),
                TransportToPlatformType(localAddress),
                0
            );
            
            bMakeCloseExec = true;
        }

        if (this->osHandle_ == -1)
        {
            NetError error;
            NetError_SetCurrent(error);
            this->SendErrorNoStream(error);
            return false;
        }

        if (bMakeCloseExec)
        {
            this->MakeCloseonexec();
        }

        return this->MakeNonblocking();
    }

    bool SocketServerImpl::ImplBind()
    {
        if (::bind(this->osHandle_,
            (sockaddr *)this->localEndpoint_.hint, this->endpointSize_) != 0)
        {
            NetError error;
            NetError_SetCurrent(error);
            this->SendErrorNoStream(error);
            return false;
        }
        return true;
    }

    bool SocketServerImpl::ImplListen()
    {
        /*
            Picking 512 because....

            "The maximum length of the queue of pending connections. If set to SOMAXCONN, the underlying service provider responsible for socket s
             will set the backlog to a maximum reasonable value. If set to SOMAXCONN_HINT(N) (where N is a number), the backlog value will be N,
             adjusted to be within the range (200, 65535). Note that SOMAXCONN_HINT can be used to set the backlog to a larger value than possible
             with SOMAXCONN." - MSDN
             "the backlog value will be N, adjusted to be within the range (200, 65535)." - MSDN

             "If the backlog argument is greater than the value in /proc/sys/net/core/somaxconn, then it is silently capped to that value.
              Since Linux 5.4, the default in this file is 4096" - da man pages

             We need a sane number between the two. 512 seems reasonable
        */
        if (::listen(this->osHandle_, this->uBacklog) != 0)
        {
            NetError error;
            NetError_SetCurrent(error);
            this->SendErrorNoStream(error);
            return false;
        }

        return true;
    }

    bool SocketServerImpl::BeginAcceptLoop()
    {
        return this->acceptOperation_.InitOnce();
    }

    void SocketServerImpl::DetroyServer()
    {
        this->acceptOperation_.Destroy();
    }
}