[+] UNIX FD sharing (with Linux optimization and a potentially functional BSD fallback)

[+] IPCHandle
[*] Clean up IO init

Include/Aurora/IO/IO.hpp

@@ -18,3 +18,7 @@
 #include "FS/FS.hpp"
 #include "Net/Net.hpp"
 #include "Character/Character.hpp"
+
+#if defined(AURORA_IS_POSIX_DERIVED)
+    #include "UNIX/UNIX.hpp"
+#endif

Include/Aurora/IO/UNIX/UNIX.hpp

@@ -0,0 +1,17 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: UNIX.hpp
+    Date: 2022-4-14
+    Author: Reece
+***/
+#pragma once
+
+namespace Aurora::IO::UNIX
+{
+    AUKN_SYM AuString ShareFileDescriptor(int fd);
+
+    AUKN_SYM void ShareFileDescriptorStop(const AuString &handle);
+
+    AUKN_SYM int ShareFileDescriptorAccept(const AuString &handle);
+}

Source/Entrypoint.cpp

@@ -15,6 +15,7 @@
 #include "Locale/Locale.hpp"
 #include "Console/Console.hpp"
 #include "IO/FS/FS.hpp"
+#include "IO/IO.hpp"
 #include "Hashing/Hashing.hpp"
 #include "Debug/Debug.hpp"
 #include "Async/Async.hpp"
@@ -25,10 +26,6 @@
 #if defined(AURORA_PLATFORM_WIN32)
     #include "Extensions/Win32/DarkTheme.hpp"
 #endif
-#if defined(AURORA_IS_POSIX_DERIVED)
-    #include "IO/UNIX/UnixIO.hpp"
-#endif
-//#include "IO/Net/Net.hpp"
 #include "Process/ProcessMap.hpp"
 #include "Exit/Exit.hpp"
 #include "CmdLine/CmdLine.hpp"
@@ -48,13 +45,10 @@ static void Init()
     Aurora::Exit::InitExit();
     Aurora::Console::Init();
     Aurora::IO::FS::InitResources();
-#if defined(AURORA_IS_POSIX_DERIVED)
-    Aurora::IO::UNIX::InitUnixIO();
-#endif
+    Aurora::IO::Init();
     Aurora::Console::Init2();
     Aurora::HWInfo::Init();
     Aurora::Telemetry::Init();
-    //Aurora::IO::Net::InitNetworking();
     Aurora::Grug::InitGrug();
     Aurora::Debug::InitDebug();
     Aurora::Locale::Init();
@@ -77,9 +71,9 @@ static void Deinit()
     Aurora::Async::ShutdownAsync();
     Aurora::Grug::DeinitGrug();
     Aurora::Console::Exit();
-    //Aurora::IO::Net::DeinitNetworking();
     Aurora::Processes::Deinit();
     Aurora::Exit::DeinitExit();
+    Aurora::IO::Deinit();
 }
 
 namespace Aurora

Source/IO/FS/Async.Linux.cpp

@@ -142,6 +142,12 @@ namespace Aurora::IO::FS
             return false;
         }
 
+        if (!ApplyDumbAdvisoryLock(fileHandle, lock))
+        {
+            SysPushErrorIO("Couldn't open file: {}. File node (not section) is locked.", path);
+            return false;
+        }
+
         this->directIO = directIO;
         this->handle = fileHandle;
         this->readOnly = openMode == EFileOpenMode::eRead;

Source/IO/IO.cpp

@@ -0,0 +1,41 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IO.cpp
+    Date: 2022-4-14
+    Author: Reece
+***/
+#include <Source/RuntimeInternal.hpp>
+#include "IO.hpp"
+
+#if defined(AURORA_IS_POSIX_DERIVED)
+    #include "UNIX/UnixIO.hpp"
+#endif
+
+#if defined(AURORA_IS_LINUX_DERIVED)
+    #include "UNIX/IOSubmit.Linux.hpp"
+#endif
+
+namespace Aurora::IO
+{
+    void Init()
+    {
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        UNIX::InitUnixIO();
+    #endif
+    }
+    
+    void Deinit()
+    {
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        UNIX::DeinitUnixIO();
+    #endif
+    }
+
+    AUKN_SYM void SendBatched()
+    {
+    #if defined(AURORA_IS_LINUX_DERIVED)
+        UNIX::SendIOBuffers();
+    #endif
+    }
+}

Source/IO/IO.hpp

@@ -0,0 +1,14 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IO.cpp
+    Date: 2022-4-14
+    Author: Reece
+***/
+#pragma once
+
+namespace Aurora::IO
+{
+    void Init();
+    void Deinit();
+}

Source/IO/UNIX/FDIpcServer.cpp

@@ -0,0 +1,461 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: FDIpcServer.cpp
+    Date: 2022-4-12
+    Author: Reece
+***/
+#include <Source/RuntimeInternal.hpp>
+#include "UnixIO.hpp"
+#include "FDIpcServer.hpp"
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <Source/IO/FS/FS.hpp>
+#include <sys/syscall.h>
+#include <fcntl.h>
+
+#if defined(AURORA_IS_LINUX_DERIVED)
+
+static int pidfd_getfd(int pidfd, int targetfd,
+                       unsigned int flags)
+{
+    return syscall(SYS_pidfd_getfd, pidfd, targetfd, flags);
+}
+
+static int pidfd_open(pid_t pid, unsigned int flags)
+{
+    return syscall(SYS_pidfd_open, pid, flags);
+}
+
+#if !defined(PIDFD_NONBLOCK)
+    #define PIDFD_NONBLOCK O_NONBLOCK
+#endif
+
+#endif
+
+namespace Aurora::IO::UNIX
+{
+    static AuThreadPrimitives::SpinLock gSpinLock;
+    static AuThreads::ThreadUnique_t gUnixIPCHandleServeThread;
+    static AuThreadPrimitives::EventUnique_t gReadyEvent;
+    static AuBST<AuUInt32, int> gFdCookieMap; 
+    static bool gHasProcSyscall  {};
+
+    static int WriteDescripitor(int socket, AuUInt32 cookie, int fd)
+    {
+        if ((fd == -1) ||
+            (socket == -1))
+        {
+            return -1;
+        }
+
+        struct iovec iov 
+        {
+            .iov_base = &cookie,
+            .iov_len = sizeof(cookie)
+        };
+
+        struct msghdr msg
+        {
+            .msg_iov = &iov,
+            .msg_iovlen = 1,
+            .msg_name = nullptr,
+            .msg_namelen = 0
+        };
+
+    #if defined(AURORA_IS_LINUX_DERIVED) // smells
+        
+        union {
+            char buf[CMSG_SPACE(sizeof(fd))];
+            struct cmsghdr align;
+        } u;
+
+        msg.msg_control = u.buf;
+        msg.msg_controllen = sizeof(u.buf);
+
+        struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+        *cmsg = (struct cmsghdr){.cmsg_level = SOL_SOCKET,
+                                 .cmsg_type = SCM_RIGHTS,
+                                 .cmsg_len = CMSG_LEN(sizeof(fd))};
+
+        AuWriteU32(CMSG_DATA(cmsg), 0, fd);
+    #else // lain hue
+        msg.msg_accrights = (caddr_t) &fd;
+        msg.msg_accrightslen = sizeof(fd);
+    #endif
+
+        return ::sendmsg(socket, &msg, 0);
+    }
+
+    static int ReadDescriptor(int socket, AuUInt32 cookie)
+    {
+        AuUInt32 foreignCookie {};
+        int newFd {-1};
+        int ret {};
+
+        if (socket == -1)
+        {
+            return -1;
+        }
+
+        struct iovec iov 
+        {
+            .iov_base = &foreignCookie,
+            .iov_len = sizeof(foreignCookie)
+        };
+
+        struct msghdr msg
+        {
+            .msg_iov = &iov,
+            .msg_iovlen = 1,
+            .msg_name = nullptr,
+            .msg_namelen = 0
+        };
+
+    #if defined(AURORA_IS_LINUX_DERIVED)
+        union {
+            char buf[CMSG_SPACE(sizeof(newFd))];
+            struct cmsghdr align;
+        } u;
+
+        msg.msg_control = u.buf;
+        msg.msg_controllen = sizeof(u.buf);
+    #else
+        msg.msg_accrights = (caddr_t) &newFd;
+        msg.msg_accrightslen = sizeof(newFd);
+    #endif
+
+        if ((ret = ::recvmsg(socket, &msg, 0)) <= 0)
+        {
+            return ret;
+        }
+
+    #if defined(AURORA_IS_LINUX_DERIVED)
+        auto cmptr = CMSG_FIRSTHDR(&msg);
+        if (!cmptr)
+        {
+            SysPushErrorIO();
+            return -1;
+        }
+
+        if (cmptr->cmsg_len != CMSG_LEN(sizeof(int)))
+        {
+            SysPushErrorIO("IPC FD Packet interrupted");
+            return -1;
+        }
+
+        if (cmptr->cmsg_level != SOL_SOCKET)
+        {
+            SysPushErrorIO("cmsg_level expected SOL_SOCKET");
+            return -1;
+        }
+
+        if (cmptr->cmsg_type != SCM_RIGHTS)
+        {
+            SysPushErrorIO("cmsg_type expected SCM_RIGHTS");
+            return -1;
+        }
+
+        return AuReadU32(CMSG_DATA(cmptr), 0);
+
+    #else
+
+        if (msg.msg_accrightslen != sizeof(int))
+        {
+            SysPushErrorIO("IPC FD Packet interrupted");
+            return -1;
+        }
+
+        return newFd;
+
+    #endif
+    }
+
+    static bool WriteDescripitorRequest(int socket, AuUInt32 cookie)
+    {
+        return ::write(socket, &cookie, sizeof(cookie)) == sizeof(cookie);
+    }
+
+    static bool ReadDescripitorRequest(int socket, AuUInt32 &cookie)
+    {
+        timeval tv {};
+        tv.tv_usec = 5000;
+        ::setsockopt(socket, SOL_SOCKET, SO_RCVTIMEO, AuReinterpretCast<const char *>(&tv), sizeof(tv));
+        return ::read(socket, &cookie, sizeof(cookie)) == sizeof(cookie);
+    }
+
+    static AuString GetServerPath(pid_t pid)
+    {
+        AuString path;
+
+#if 0
+        if (!AuIOFS::GetUserProgramsFolder(path))
+        {
+            path = "/opt/";
+        }
+#endif
+        path += "/tmp/UNIX_IPC/";
+        path += AuToString(AuUInt32(pid));
+        return path;
+    }
+
+    static bool GetServerName(sockaddr_un &sockAddr, pid_t pid)
+    {
+        auto path = GetServerPath(pid);
+        if (path.empty())
+        {
+            return false;
+        }
+
+        if (!AuTryResize(path, AuArraySize(sockAddr.sun_path) - 1))
+        {
+            return false;
+        }
+
+        sockAddr.sun_family = AF_UNIX;
+        AuMemcpy(sockAddr.sun_path, path.c_str(), path.size());
+        return true;
+    }
+
+    static void ServerThread()
+    {
+        sockaddr_un addr {};
+
+        int fd = ::socket(AF_UNIX, SOCK_STREAM, 0);
+        if (fd <= 0)
+        {
+            SysPanic("Couldn't spawn IPC socket");
+        }
+
+        if (!GetServerName(addr, getpid()))
+        {
+            ::close(fd);
+            SysPanic("Get IPC socket server name");
+        }
+
+        AuIOFS::CreateDirectories(addr.sun_path, true);
+
+        if (::bind(fd, AuReinterpretCast<struct sockaddr *>(&addr), sizeof(addr)) == -1)
+        {
+            SysPanic("Couldn't bind IPC socket {}", errno);
+        }
+
+        if (::listen(fd, 128) == -1)
+        {
+            SysPanic("Couldn't listen to IPC socket {}", errno);
+        }
+
+        gReadyEvent->Set();
+        
+        while (AuIsThreadRunning())
+        {
+            AuUInt32 cookie;
+
+            int client = ::accept(fd, NULL, NULL);
+            if (client == -1)
+            {
+                SysPushErrorIO("IPC accept error {}", errno);
+                continue;
+            }
+
+            if (!ReadDescripitorRequest(client, cookie))
+            {
+                SysPushErrorIO("IPC request timed out {}", errno);
+                goto cont;
+            }
+
+            {
+                AU_LOCK_GUARD(gSpinLock);
+
+                auto itr = gFdCookieMap.find(cookie);
+                if (itr == gFdCookieMap.end())
+                {
+                    SysPushErrorIO("Missing IPC cookie: {}", cookie);
+                    goto cont;
+                }
+
+                if (!WriteDescripitor(client, cookie, itr->second))
+                {
+                    SysPushErrorIO("Couldn't write IPC packet");
+                    goto cont;
+                }
+            }
+
+        cont:
+            ::close(client);
+        }
+
+        ::close(fd);
+    }
+
+    static bool ReadyServer()
+    {   
+        if (gUnixIPCHandleServeThread)
+        {
+            return true;
+        }
+
+        gReadyEvent = AuThreadPrimitives::EventUnique(false, false, true);
+        if (!gReadyEvent)
+        {
+            return false;
+        } 
+
+        gUnixIPCHandleServeThread = AuThreads::ThreadUnique(AuThreads::ThreadInfo(
+            AuMakeShared<AuThreads::IThreadVectorsFunctional>(AuThreads::IThreadVectorsFunctional::OnEntry_t(std::bind(ServerThread)),
+                                                              AuThreads::IThreadVectorsFunctional::OnExit_t{}),
+            "UNIX IPC File Descriptor Server"
+        ));
+
+        if (!gUnixIPCHandleServeThread)
+        {
+            gReadyEvent.reset();
+            return false;
+        }
+
+        if (!gUnixIPCHandleServeThread->Run())
+        {
+            return bool(gUnixIPCHandleServeThread = {});
+        }
+
+        gReadyEvent->Lock();
+        gReadyEvent.reset();
+        return true;
+    }
+
+    static bool Ready()
+    {
+        AU_LOCK_GUARD(gSpinLock);
+
+        if (gHasProcSyscall)
+        {
+            return true;
+        }
+
+        return ReadyServer();
+    }
+
+    bool FDServe(bool a, bool b, bool c, bool d, int fd, IPC::IPCHandle &outHandle)
+    {
+        if (gHasProcSyscall)
+        {
+            outHandle.NewId(a, b, c, d);
+            outHandle.cookie = fd;
+            return true;
+        }
+
+        if (!Ready())
+        {
+            return false;
+        }
+
+        {
+            AU_LOCK_GUARD(gSpinLock);
+
+            do
+            {
+                outHandle.NewId(a, b, c, d);
+            } while (AuExists(gFdCookieMap, outHandle.cookie));
+
+            return AuTryInsert(gFdCookieMap, outHandle.cookie, fd);         
+        }
+    }
+
+    void FDServeEnd(const IPC::IPCHandle &handle)
+    {
+        if (gHasProcSyscall)
+        {
+            return;
+        }
+
+        AU_LOCK_GUARD(gSpinLock);
+        AuTryRemove(gFdCookieMap, handle.cookie);
+    }
+
+    bool FDAccept(const IPC::IPCHandle &handle, int &outFd)
+    {
+        sockaddr_un addr;
+        outFd = -1;
+
+        if (gHasProcSyscall)
+        {
+        #if defined(AURORA_IS_LINUX_DERIVED)
+
+            int pid = ::pidfd_open(handle.ToUnixPid(), 0);
+            if (pid <= 0)
+            {
+                SysPushErrorIO("Couldn't open IPC server pid, error: {}", pid);
+                return false;
+            }
+
+            int result = ::pidfd_getfd(pid, handle.cookie, 0);
+            if (result <= 0)
+            {
+                SysPushErrorIO("Couldn't get IPC fd, error: {} {}", result, errno);
+                ::close(pid);
+                return false;
+            }
+
+            ::close(pid);
+            outFd = result;
+            return true;
+
+        #endif
+        }
+
+        int fd = ::socket(AF_UNIX, SOCK_STREAM, 0);
+        if (fd <= -1)
+        {
+            SysPushErrorIO("No Resource?");
+            return false;
+        }
+
+        if (!GetServerName(addr, handle.ToUnixPid()))
+        {
+            ::close(fd);
+            SysPushErrorIO("Couldn't get remote IPC socket server name");
+            return false;
+        }
+
+        if (::connect(fd, AuReinterpretCast<struct sockaddr *>(&addr), sizeof(addr)) == -1)
+        {
+            ::close(fd);
+            SysPushErrorIO("Couldn't connect to remote IPC fd server");
+            return false;
+        }
+
+        if (!WriteDescripitorRequest(fd, handle.cookie))
+        {
+            SysPushErrorIO("Couldn't write FD request to IPC server");
+            return false;
+        }
+
+        outFd = ReadDescriptor(fd, handle.cookie);
+        if (outFd == -1)
+        {
+            SysPushErrorNested();
+        }
+
+        return true;
+    }
+
+    void InitIPCBackend()
+    {
+    #if defined(AURORA_IS_LINUX_DERIVED)
+        auto &platform = AuSwInfo::GetPlatformInfo();
+
+        if ((platform.uKernelMajor > 5) ||
+            ((platform.uKernelMajor == 5) && (platform.uKernelMinor >= 6)))
+        {
+            gHasProcSyscall  = true;
+        }
+    #endif
+    }
+
+    void DeinitIPCBackend()
+    {
+        gUnixIPCHandleServeThread.reset();
+        gFdCookieMap.clear();
+        gReadyEvent.reset();
+    }
+}

Source/IO/UNIX/FDIpcServer.hpp

@@ -0,0 +1,21 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: FDIpcServer.hpp
+    Date: 2022-4-12
+    Author: Reece
+***/
+#pragma once
+
+#include <Source/IPC/IPCHandle.hpp>
+
+namespace Aurora::IO::UNIX
+{
+    void InitIPCBackend();
+    void DeinitIPCBackend();
+
+    bool FDServe(bool a, bool b, bool c, bool d, int fd, IPC::IPCHandle &outHandle);
+    void FDServeEnd(const IPC::IPCHandle &handle);
+
+    bool FDAccept(const IPC::IPCHandle &handle, int &outFd);
+}

Source/IO/UNIX/UnixIO.cpp

@@ -7,27 +7,60 @@
 ***/
 #include <Source/RuntimeInternal.hpp>
 #include "UnixIO.hpp"
+#include "FDIpcServer.hpp"
 
 namespace Aurora::IO::UNIX
 {
+    AUKN_SYM AuString ShareFileDescriptor(int fd)
+    {
+        IPC::IPCHandle handle;
+
+        if (!FDServe(false, false, false, false, fd, handle))
+        {
+            return {};
+        }
+
+        return handle.ToString();
+    }
+
+    AUKN_SYM void ShareFileDescriptorStop(const AuString &handle)
+    {
+        IPC::IPCHandle handle2;
+        if (!handle2.FromString(handle))
+        {
+            SysPushErrorIO("Invalid handle string");
+            return;
+        }
+
+        FDServeEnd(handle2);
+    }
+
+    AUKN_SYM int ShareFileDescriptorAccept(const AuString &handle)
+    {
+        IPC::IPCHandle handle2;
+        if (!handle2.FromString(handle))
+        {
+            SysPushErrorIO("Invalid handle string");
+            return -1;
+        }
+
+        int fd {-1};
+        if (!FDAccept(handle2, fd))
+        {
+            SysPushErrorNested();
+            return -1;
+        }
+
+        return fd;
+    }
+
     void InitUnixIO()
     {
-
-
-	}
+        InitIPCBackend();
     }
 
-
-#if defined(AURORA_IS_LINUX_DERIVED)
-    #include "IOSubmit.Linux.hpp"
-#endif
-
-namespace Aurora::IO
+    void DeinitUnixIO()
     {
-    AUKN_SYM void SendBatched()
-    {
-    #if defined(AURORA_IS_LINUX_DERIVED)
-        UNIX::SendIOBuffers();
-    #endif
+        DeinitIPCBackend();
     }
 }

Source/IO/UNIX/UnixIO.hpp

@@ -10,4 +10,5 @@
 namespace Aurora::IO::UNIX
 {
 	void InitUnixIO();
+    void DeinitUnixIO();
 }

Source/IPC/IPC.cpp

@@ -0,0 +1,14 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IPC.cpp
+    Date: 2022-4-13
+    Author: Reece
+***/
+#include <Source/RuntimeInternal.hpp>
+#include "IPC.hpp"
+
+namespace Aurora::IPC
+{
+    
+}

Source/IPC/IPC.hpp

@@ -0,0 +1,13 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IPC.hpp
+    Date: 2022-4-13
+    Author: Reece
+***/
+#pragma once
+
+namespace Aurora::IPC
+{
+    
+}

Source/IPC/IPCHandle.cpp

@@ -0,0 +1,149 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IPCHandle.cpp
+    Date: 2022-4-13
+    Author: Reece
+***/
+#include <Source/RuntimeInternal.hpp>
+#include "IPC.hpp"
+#include "IPCHandle.hpp"
+
+namespace Aurora::IPC
+{
+    #define AURORA_IPC_BRAND "AuroraIPC_"
+
+    // A horribly inefficient parsable handle.
+    // Dead simple to implement, it's 22:07, and i wanna sleep soon.
+    // We should text serialize a bitmap later...
+
+    void IPCHandle::NewId(bool a, bool b, bool c, bool d)
+    {
+        this->flags[0] = a;
+        this->flags[1] = b;
+        this->flags[2] = c;
+        this->flags[3] = d;
+
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        this->cookie = AuRng::RngU32();
+        this->pid = getpid();
+    #else
+        auto temp = AuRng::ReadString(AuArraySize(this->path), AuRng::ERngStringCharacters::eAlphaNumericCharacters);
+        AuMemcpy(this->path, temp.data(), data.size());
+    #endif
+    }
+
+    bool IPCHandle::FromString(const AuString &in)
+    {
+        if (in.size() < 4)
+        {
+            return false;
+        }
+
+        this->flags[0] = in[0] == 'Y';
+        this->flags[1] = in[1] == 'Y';
+        this->flags[2] = in[2] == 'Y';
+        this->flags[3] = in[3] == 'Y';
+
+    #if defined(AURORA_IS_MODERNNT_DERIVED)
+        if (in.size() != 4 + 16)
+        {
+            return false;
+        }
+
+        AuMemcpy(path, &in[4], 16);
+    #endif
+
+    #if defined(AURORA_IS_POSIX_DERIVED)
+
+        char *endPtr;
+        auto word = strtoll(in.c_str() + 4, &endPtr, 10);
+        if (errno == ERANGE)
+        {
+            return false;
+        }
+
+        if (*endPtr != '_')
+        {
+            return false;
+        }
+
+        this->cookie = word;
+
+        word = strtoll(endPtr + 1, &endPtr, 10);
+        if (errno == ERANGE)
+        {
+            return false;
+        }
+
+        if (*endPtr != '\00')
+        {
+            return false;
+        }
+
+        this->pid = word;
+        
+        return true;
+    #endif
+    }
+
+    AuString IPCHandle::ToString() const
+    {
+        AuString ret;
+
+    #if defined(AURORA_IS_MODERNNT_DERIVED)
+        if (!AuTryResize(ret, 4 + 16))
+        {
+            return {};
+        }
+    #endif
+
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        if (!AuTryResize(ret, 4))
+        {
+            return {};
+        }
+    #endif
+
+        ret[0] = this->flags[0] ? 'Y' : 'N';
+        ret[1] = this->flags[1] ? 'Y' : 'N';
+        ret[2] = this->flags[2] ? 'Y' : 'N';
+        ret[3] = this->flags[3] ? 'Y' : 'N';
+
+    #if defined(AURORA_IS_MODERNNT_DERIVED)
+        AuMemcpy(&ret[4], this->path, 16);
+    #endif
+
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        ret += AuToString(this->cookie);
+        ret += '_';
+        ret += AuToString(this->pid);
+    #endif
+
+        return ret;
+    }
+
+    AuString IPCHandle::ToNTPath() const
+    {
+        if (this->flags[3])
+        {
+            return "Global\\" AURORA_IPC_BRAND + AuString(this->path, this->path + 16);
+        }
+        else
+        {
+            return "Local\\" AURORA_IPC_BRAND + AuString(this->path, this->path + 16);
+        }
+    }
+
+    AuUInt32 IPCHandle::ToUnixServerCookie() const
+    {
+        return this->cookie;
+    }
+
+#if defined(AURORA_IS_POSIX_DERIVED)
+    pid_t IPCHandle::ToUnixPid() const
+    {
+        return this->pid;
+    }
+#endif
+}

Source/IPC/IPCHandle.hpp

@@ -0,0 +1,36 @@
+/***
+    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
+
+    File: IPCHandle.hpp
+    Date: 2022-4-13
+    Author: Reece
+***/
+#pragma once
+
+namespace Aurora::IPC
+{
+    struct IPCHandle
+    {
+        bool flags[4];
+
+        union
+        {
+            char path[16];
+            struct
+            {
+                AuUInt32 cookie;
+                AuUInt32 pid;
+            };
+        };
+
+        void NewId(bool a, bool b, bool c, bool d);
+        bool FromString(const AuString &in);
+        AuString ToString() const;
+        AuString ToNTPath() const;
+        AuUInt32 ToUnixServerCookie() const;
+
+    #if defined(AURORA_IS_POSIX_DERIVED)
+        pid_t ToUnixPid() const;
+    #endif
+    };
+}