Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1649 insertions, 0 deletions

diff --git a/src/VBox/ValidationKit/utils/usb/UsbTestService.cpp b/src/VBox/ValidationKit/utils/usb/UsbTestService.cpp
new file mode 100644
index 00000000..dc77f2d4
--- /dev/null
+++ b/src/VBox/ValidationKit/utils/usb/UsbTestService.cpp
@@ -0,0 +1,1649 @@
+/* $Id: UsbTestService.cpp $ */
+/** @file
+ * UsbTestService - Remote USB test configuration and execution server.
+ */
+
+/*
+ * Copyright (C) 2010-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#define LOG_GROUP RTLOGGROUP_DEFAULT
+#include <iprt/alloca.h>
+#include <iprt/asm.h>
+#include <iprt/assert.h>
+#include <iprt/critsect.h>
+#include <iprt/crc.h>
+#include <iprt/ctype.h>
+#include <iprt/dir.h>
+#include <iprt/env.h>
+#include <iprt/err.h>
+#include <iprt/getopt.h>
+#include <iprt/handle.h>
+#include <iprt/initterm.h>
+#include <iprt/json.h>
+#include <iprt/list.h>
+#include <iprt/log.h>
+#include <iprt/mem.h>
+#include <iprt/message.h>
+#include <iprt/param.h>
+#include <iprt/path.h>
+#include <iprt/pipe.h>
+#include <iprt/poll.h>
+#include <iprt/process.h>
+#include <iprt/stream.h>
+#include <iprt/string.h>
+#include <iprt/thread.h>
+
+#include "UsbTestServiceInternal.h"
+#include "UsbTestServiceGadget.h"
+#include "UsbTestServicePlatform.h"
+
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+
+#define UTS_USBIP_PORT_FIRST 3240
+#define UTS_USBIP_PORT_LAST  3340
+
+/**
+ * UTS client state.
+ */
+typedef enum UTSCLIENTSTATE
+{
+    /** Invalid client state. */
+    UTSCLIENTSTATE_INVALID = 0,
+    /** Client is initialising, only the HOWDY and BYE packets are allowed. */
+    UTSCLIENTSTATE_INITIALISING,
+    /** Client is in fully cuntional state and ready to process all requests. */
+    UTSCLIENTSTATE_READY,
+    /** Client is destroying. */
+    UTSCLIENTSTATE_DESTROYING,
+    /** 32bit hack. */
+    UTSCLIENTSTATE_32BIT_HACK = 0x7fffffff
+} UTSCLIENTSTATE;
+
+/**
+ * UTS client instance.
+ */
+typedef struct UTSCLIENT
+{
+    /** List node for new clients. */
+    RTLISTNODE             NdLst;
+    /** The current client state. */
+    UTSCLIENTSTATE         enmState;
+    /** Transport backend specific data. */
+    PUTSTRANSPORTCLIENT    pTransportClient;
+    /** Client hostname. */
+    char                  *pszHostname;
+    /** Gadget host handle. */
+    UTSGADGETHOST          hGadgetHost;
+    /** Handle fo the current configured gadget. */
+    UTSGADGET              hGadget;
+} UTSCLIENT;
+/** Pointer to a UTS client instance. */
+typedef UTSCLIENT *PUTSCLIENT;
+
+
+/*********************************************************************************************************************************
+*   Global Variables                                                                                                             *
+*********************************************************************************************************************************/
+/**
+ * Transport layers.
+ */
+static const PCUTSTRANSPORT g_apTransports[] =
+{
+    &g_TcpTransport,
+    //&g_SerialTransport,
+    //&g_FileSysTransport,
+    //&g_GuestPropTransport,
+    //&g_TestDevTransport,
+};
+
+/** The select transport layer. */
+static PCUTSTRANSPORT       g_pTransport;
+/** The config path. */
+static char                 g_szCfgPath[RTPATH_MAX];
+/** The scratch path. */
+static char                 g_szScratchPath[RTPATH_MAX];
+/** The default scratch path. */
+static char                 g_szDefScratchPath[RTPATH_MAX];
+/** The CD/DVD-ROM path. */
+static char                 g_szCdRomPath[RTPATH_MAX];
+/** The default CD/DVD-ROM path. */
+static char                 g_szDefCdRomPath[RTPATH_MAX];
+/** The operating system short name. */
+static char                 g_szOsShortName[16];
+/** The CPU architecture short name. */
+static char                 g_szArchShortName[16];
+/** The combined "OS.arch" name. */
+static char                 g_szOsDotArchShortName[32];
+/** The combined "OS/arch" name. */
+static char                 g_szOsSlashArchShortName[32];
+/** The executable suffix. */
+static char                 g_szExeSuff[8];
+/** The shell script suffix. */
+static char                 g_szScriptSuff[8];
+/** Whether to display the output of the child process or not.  */
+static bool                 g_fDisplayOutput = true;
+/** Whether to terminate or not.
+ * @todo implement signals and stuff.  */
+static bool volatile        g_fTerminate = false;
+/** Configuration AST. */
+static RTJSONVAL            g_hCfgJson = NIL_RTJSONVAL;
+/** Pipe for communicating with the serving thread about new clients. - read end */
+static RTPIPE               g_hPipeR;
+/** Pipe for communicating with the serving thread about new clients. - write end */
+static RTPIPE               g_hPipeW;
+/** Thread serving connected clients. */
+static RTTHREAD             g_hThreadServing;
+/** Critical section protecting the list of new clients. */
+static RTCRITSECT           g_CritSectClients;
+/** List of new clients waiting to be picked up by the client worker thread. */
+static RTLISTANCHOR         g_LstClientsNew;
+/** First USB/IP port we can use. */
+static uint16_t             g_uUsbIpPortFirst = UTS_USBIP_PORT_FIRST;
+/** Last USB/IP port we can use. */
+static uint16_t             g_uUsbIpPortLast  = UTS_USBIP_PORT_LAST;
+/** Next free port. */
+static uint16_t             g_uUsbIpPortNext  = UTS_USBIP_PORT_FIRST;
+
+
+
+/**
+ * Returns the string represenation of the given state.
+ */
+static const char *utsClientStateStringify(UTSCLIENTSTATE enmState)
+{
+    switch (enmState)
+    {
+        case UTSCLIENTSTATE_INVALID:
+            return "INVALID";
+        case UTSCLIENTSTATE_INITIALISING:
+            return "INITIALISING";
+        case UTSCLIENTSTATE_READY:
+            return "READY";
+        case UTSCLIENTSTATE_DESTROYING:
+            return "DESTROYING";
+        case UTSCLIENTSTATE_32BIT_HACK:
+        default:
+            break;
+    }
+
+    AssertMsgFailed(("Unknown state %#x\n", enmState));
+    return "UNKNOWN";
+}
+
+/**
+ * Calculates the checksum value, zero any padding space and send the packet.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPkt                The packet to send.  Must point to a correctly
+ *                              aligned buffer.
+ */
+static int utsSendPkt(PUTSCLIENT pClient, PUTSPKTHDR pPkt)
+{
+    Assert(pPkt->cb >= sizeof(*pPkt));
+    pPkt->uCrc32 = RTCrc32(pPkt->achOpcode, pPkt->cb - RT_UOFFSETOF(UTSPKTHDR, achOpcode));
+    if (pPkt->cb != RT_ALIGN_32(pPkt->cb, UTSPKT_ALIGNMENT))
+        memset((uint8_t *)pPkt + pPkt->cb, '\0', RT_ALIGN_32(pPkt->cb, UTSPKT_ALIGNMENT) - pPkt->cb);
+
+    Log(("utsSendPkt: cb=%#x opcode=%.8s\n", pPkt->cb, pPkt->achOpcode));
+    Log2(("%.*Rhxd\n", RT_MIN(pPkt->cb, 256), pPkt));
+    int rc = g_pTransport->pfnSendPkt(pClient->pTransportClient, pPkt);
+    while (RT_UNLIKELY(rc == VERR_INTERRUPTED) && !g_fTerminate)
+        rc = g_pTransport->pfnSendPkt(pClient->pTransportClient, pPkt);
+    if (RT_FAILURE(rc))
+        Log(("utsSendPkt: rc=%Rrc\n", rc));
+
+    return rc;
+}
+
+/**
+ * Sends a babble reply and disconnects the client (if applicable).
+ *
+ * @param   pClient             The UTS client structure.
+ * @param   pszOpcode           The BABBLE opcode.
+ */
+static void utsReplyBabble(PUTSCLIENT pClient, const char *pszOpcode)
+{
+    UTSPKTHDR Reply;
+    Reply.cb     = sizeof(Reply);
+    Reply.uCrc32 = 0;
+    memcpy(Reply.achOpcode, pszOpcode, sizeof(Reply.achOpcode));
+
+    g_pTransport->pfnBabble(pClient->pTransportClient, &Reply, 20*1000);
+}
+
+/**
+ * Receive and validate a packet.
+ *
+ * Will send bable responses to malformed packets that results in a error status
+ * code.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   ppPktHdr            Where to return the packet on success.  Free
+ *                              with RTMemFree.
+ * @param   fAutoRetryOnFailure Whether to retry on error.
+ */
+static int utsRecvPkt(PUTSCLIENT pClient, PPUTSPKTHDR ppPktHdr, bool fAutoRetryOnFailure)
+{
+    for (;;)
+    {
+        PUTSPKTHDR pPktHdr;
+        int rc = g_pTransport->pfnRecvPkt(pClient->pTransportClient, &pPktHdr);
+        if (RT_SUCCESS(rc))
+        {
+            /* validate the packet. */
+            if (   pPktHdr->cb >= sizeof(UTSPKTHDR)
+                && pPktHdr->cb < UTSPKT_MAX_SIZE)
+            {
+                Log2(("utsRecvPkt: pPktHdr=%p cb=%#x crc32=%#x opcode=%.8s\n"
+                      "%.*Rhxd\n",
+                      pPktHdr, pPktHdr->cb, pPktHdr->uCrc32, pPktHdr->achOpcode, RT_MIN(pPktHdr->cb, 256), pPktHdr));
+                uint32_t uCrc32Calc = pPktHdr->uCrc32 != 0
+                                    ? RTCrc32(&pPktHdr->achOpcode[0], pPktHdr->cb - RT_UOFFSETOF(UTSPKTHDR, achOpcode))
+                                    : 0;
+                if (pPktHdr->uCrc32 == uCrc32Calc)
+                {
+                    AssertCompileMemberSize(UTSPKTHDR, achOpcode, 8);
+                    if (   RT_C_IS_UPPER(pPktHdr->achOpcode[0])
+                        && RT_C_IS_UPPER(pPktHdr->achOpcode[1])
+                        && (RT_C_IS_UPPER(pPktHdr->achOpcode[2]) || pPktHdr->achOpcode[2] == ' ')
+                        && (RT_C_IS_PRINT(pPktHdr->achOpcode[3]) || pPktHdr->achOpcode[3] == ' ')
+                        && (RT_C_IS_PRINT(pPktHdr->achOpcode[4]) || pPktHdr->achOpcode[4] == ' ')
+                        && (RT_C_IS_PRINT(pPktHdr->achOpcode[5]) || pPktHdr->achOpcode[5] == ' ')
+                        && (RT_C_IS_PRINT(pPktHdr->achOpcode[6]) || pPktHdr->achOpcode[6] == ' ')
+                        && (RT_C_IS_PRINT(pPktHdr->achOpcode[7]) || pPktHdr->achOpcode[7] == ' ')
+                       )
+                    {
+                        Log(("utsRecvPkt: cb=%#x opcode=%.8s\n", pPktHdr->cb, pPktHdr->achOpcode));
+                        *ppPktHdr = pPktHdr;
+                        return rc;
+                    }
+
+                    rc = VERR_IO_BAD_COMMAND;
+                }
+                else
+                {
+                    Log(("utsRecvPkt: cb=%#x opcode=%.8s crc32=%#x actual=%#x\n",
+                         pPktHdr->cb, pPktHdr->achOpcode, pPktHdr->uCrc32, uCrc32Calc));
+                    rc = VERR_IO_CRC;
+                }
+            }
+            else
+                rc = VERR_IO_BAD_LENGTH;
+
+            /* Send babble reply and disconnect the client if the transport is
+               connection oriented. */
+            if (rc == VERR_IO_BAD_LENGTH)
+                utsReplyBabble(pClient, "BABBLE L");
+            else if (rc == VERR_IO_CRC)
+                utsReplyBabble(pClient, "BABBLE C");
+            else if (rc == VERR_IO_BAD_COMMAND)
+                utsReplyBabble(pClient, "BABBLE O");
+            else
+                utsReplyBabble(pClient, "BABBLE  ");
+            RTMemFree(pPktHdr);
+        }
+
+        /* Try again or return failure? */
+        if (   g_fTerminate
+            || rc != VERR_INTERRUPTED
+            || !fAutoRetryOnFailure
+            )
+        {
+            Log(("utsRecvPkt: rc=%Rrc\n", rc));
+            return rc;
+        }
+    }
+}
+
+/**
+ * Make a simple reply, only status opcode.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pReply              The reply packet.
+ * @param   pszOpcode           The status opcode.  Exactly 8 chars long, padd
+ *                              with space.
+ * @param   cbExtra             Bytes in addition to the header.
+ */
+static int utsReplyInternal(PUTSCLIENT pClient, PUTSPKTSTS pReply, const char *pszOpcode, size_t cbExtra)
+{
+    /* copy the opcode, don't be too strict in case of a padding screw up. */
+    size_t cchOpcode = strlen(pszOpcode);
+    if (RT_LIKELY(cchOpcode == sizeof(pReply->Hdr.achOpcode)))
+        memcpy(pReply->Hdr.achOpcode, pszOpcode, sizeof(pReply->Hdr.achOpcode));
+    else
+    {
+        Assert(cchOpcode == sizeof(pReply->Hdr.achOpcode));
+        while (cchOpcode > 0 && pszOpcode[cchOpcode - 1] == ' ')
+            cchOpcode--;
+        AssertMsgReturn(cchOpcode < sizeof(pReply->Hdr.achOpcode), ("%d/'%.8s'\n", cchOpcode, pszOpcode), VERR_INTERNAL_ERROR_4);
+        memcpy(pReply->Hdr.achOpcode, pszOpcode, cchOpcode);
+        memset(&pReply->Hdr.achOpcode[cchOpcode], ' ', sizeof(pReply->Hdr.achOpcode) - cchOpcode);
+    }
+
+    pReply->Hdr.cb     = (uint32_t)sizeof(UTSPKTSTS) + (uint32_t)cbExtra;
+    pReply->Hdr.uCrc32 = 0;
+
+    return utsSendPkt(pClient, &pReply->Hdr);
+}
+
+/**
+ * Make a simple reply, only status opcode.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The original packet (for future use).
+ * @param   pszOpcode           The status opcode.  Exactly 8 chars long, padd
+ *                              with space.
+ */
+static int utsReplySimple(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, const char *pszOpcode)
+{
+    UTSPKTSTS Pkt;
+
+    RT_ZERO(Pkt);
+    Pkt.rcReq = VINF_SUCCESS;
+    Pkt.cchStsMsg = 0;
+    NOREF(pPktHdr);
+    return utsReplyInternal(pClient, &Pkt, pszOpcode, 0);
+}
+
+/**
+ * Acknowledges a packet with success.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The original packet (for future use).
+ */
+static int utsReplyAck(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    return utsReplySimple(pClient, pPktHdr, "ACK     ");
+}
+
+/**
+ * Replies with a failure.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The original packet (for future use).
+ * @param   rcReq               Status code.
+ * @param   pszOpcode           The status opcode.  Exactly 8 chars long, padd
+ *                              with space.
+ * @param   rcReq               The status code of the request.
+ * @param   pszDetailFmt        Longer description of the problem (format string).
+ * @param   va                  Format arguments.
+ */
+static int utsReplyFailureV(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, const char *pszOpcode, int rcReq, const char *pszDetailFmt, va_list va)
+{
+    NOREF(pPktHdr);
+    union
+    {
+        UTSPKTSTS   Hdr;
+        char        ach[256];
+    } uPkt;
+
+    RT_ZERO(uPkt);
+    size_t cchDetail = RTStrPrintfV(&uPkt.ach[sizeof(UTSPKTSTS)],
+                                    sizeof(uPkt) - sizeof(UTSPKTSTS),
+                                    pszDetailFmt, va);
+    uPkt.Hdr.rcReq = rcReq;
+    uPkt.Hdr.cchStsMsg = cchDetail;
+    return utsReplyInternal(pClient, &uPkt.Hdr, pszOpcode, cchDetail + 1);
+}
+
+/**
+ * Replies with a failure.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The original packet (for future use).
+ * @param   pszOpcode           The status opcode.  Exactly 8 chars long, padd
+ *                              with space.
+ * @param   rcReq               Status code.
+ * @param   pszDetailFmt        Longer description of the problem (format string).
+ * @param   ...                 Format arguments.
+ */
+static int utsReplyFailure(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, const char *pszOpcode, int rcReq, const char *pszDetailFmt, ...)
+{
+    va_list va;
+    va_start(va, pszDetailFmt);
+    int rc = utsReplyFailureV(pClient, pPktHdr, pszOpcode, rcReq, pszDetailFmt, va);
+    va_end(va);
+    return rc;
+}
+
+/**
+ * Replies according to the return code.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet to reply to.
+ * @param   rcOperation         The status code to report.
+ * @param   pszOperationFmt     The operation that failed.  Typically giving the
+ *                              function call with important arguments.
+ * @param   ...                 Arguments to the format string.
+ */
+static int utsReplyRC(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, int rcOperation, const char *pszOperationFmt, ...)
+{
+    if (RT_SUCCESS(rcOperation))
+        return utsReplyAck(pClient, pPktHdr);
+
+    char    szOperation[128];
+    va_list va;
+    va_start(va, pszOperationFmt);
+    RTStrPrintfV(szOperation, sizeof(szOperation), pszOperationFmt, va);
+    va_end(va);
+
+    return utsReplyFailure(pClient, pPktHdr, "FAILED  ", rcOperation, "%s failed with rc=%Rrc (opcode '%.8s')",
+                           szOperation, rcOperation, pPktHdr->achOpcode);
+}
+
+#if 0 /* unused */
+/**
+ * Signal a bad packet minum size.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet to reply to.
+ * @param   cbMin               The minimum size.
+ */
+static int utsReplyBadMinSize(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, size_t cbMin)
+{
+    return utsReplyFailure(pClient, pPktHdr, "BAD SIZE", VERR_INVALID_PARAMETER, "Expected at least %zu bytes, got %u (opcode '%.8s')",
+                           cbMin, pPktHdr->cb, pPktHdr->achOpcode);
+}
+#endif
+
+/**
+ * Signal a bad packet exact size.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet to reply to.
+ * @param   cb                  The wanted size.
+ */
+static int utsReplyBadSize(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr, size_t cb)
+{
+    return utsReplyFailure(pClient, pPktHdr, "BAD SIZE", VERR_INVALID_PARAMETER, "Expected at %zu bytes, got %u  (opcode '%.8s')",
+                           cb, pPktHdr->cb, pPktHdr->achOpcode);
+}
+
+#if 0 /* unused */
+/**
+ * Deals with a command that isn't implemented yet.
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet which opcode isn't implemented.
+ */
+static int utsReplyNotImplemented(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    return utsReplyFailure(pClient, pPktHdr, "NOT IMPL", VERR_NOT_IMPLEMENTED, "Opcode '%.8s' is not implemented", pPktHdr->achOpcode);
+}
+#endif
+
+/**
+ * Deals with a unknown command.
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet to reply to.
+ */
+static int utsReplyUnknown(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    return utsReplyFailure(pClient, pPktHdr, "UNKNOWN ", VERR_NOT_FOUND, "Opcode '%.8s' is not known", pPktHdr->achOpcode);
+}
+
+/**
+ * Deals with a command which contains an unterminated string.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet containing the unterminated string.
+ */
+static int utsReplyBadStrTermination(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    return utsReplyFailure(pClient, pPktHdr, "BAD TERM", VERR_INVALID_PARAMETER, "Opcode '%.8s' contains an unterminated string", pPktHdr->achOpcode);
+}
+
+/**
+ * Deals with a command sent in an invalid client state.
+ *
+ * @returns IPRT status code of the send.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The packet containing the unterminated string.
+ */
+static int utsReplyInvalidState(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    return utsReplyFailure(pClient, pPktHdr, "INVSTATE", VERR_INVALID_STATE, "Opcode '%.8s' is not supported at client state '%s",
+                           pPktHdr->achOpcode, utsClientStateStringify(pClient->enmState));
+}
+
+/**
+ * Parses an unsigned integer from the given value string.
+ *
+ * @returns IPRT status code.
+ * @retval  VERR_OUT_OF_RANGE if the parsed value exceeds the given maximum.
+ * @param   pszVal              The value string.
+ * @param   uMax                The maximum value.
+ * @param   pu64                Where to store the parsed number on success.
+ */
+static int utsDoGadgetCreateCfgParseUInt(const char *pszVal, uint64_t uMax, uint64_t *pu64)
+{
+    int rc = RTStrToUInt64Ex(pszVal, NULL, 0, pu64);
+    if (RT_SUCCESS(rc))
+    {
+        if (*pu64 > uMax)
+            rc = VERR_OUT_OF_RANGE;
+    }
+
+    return rc;
+}
+
+/**
+ * Parses a signed integer from the given value string.
+ *
+ * @returns IPRT status code.
+ * @retval  VERR_OUT_OF_RANGE if the parsed value exceeds the given range.
+ * @param   pszVal              The value string.
+ * @param   iMin                The minimum value.
+ * @param   iMax                The maximum value.
+ * @param   pi64                Where to store the parsed number on success.
+ */
+static int utsDoGadgetCreateCfgParseInt(const char *pszVal, int64_t iMin, int64_t iMax, int64_t *pi64)
+{
+    int rc = RTStrToInt64Ex(pszVal, NULL, 0, pi64);
+    if (RT_SUCCESS(rc))
+    {
+        if (   *pi64 < iMin
+            || *pi64 > iMax)
+            rc = VERR_OUT_OF_RANGE;
+    }
+
+    return rc;
+}
+
+/**
+ * Parses the given config item and fills in the value according to the given type.
+ *
+ * @returns IPRT status code.
+ * @param   pCfgItem            The config item to parse.
+ * @param   u32Type             The config type.
+ * @param   pszVal              The value encoded as a string.
+ */
+static int utsDoGadgetCreateCfgParseItem(PUTSGADGETCFGITEM pCfgItem, uint32_t u32Type,
+                                         const char *pszVal)
+{
+    int rc = VINF_SUCCESS;
+
+    switch (u32Type)
+    {
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_BOOLEAN:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_BOOLEAN;
+            if (   RTStrICmp(pszVal, "enabled")
+                || RTStrICmp(pszVal, "1")
+                || RTStrICmp(pszVal, "true"))
+                pCfgItem->Val.u.f = true;
+            else if (   RTStrICmp(pszVal, "disabled")
+                     || RTStrICmp(pszVal, "0")
+                     || RTStrICmp(pszVal, "false"))
+                pCfgItem->Val.u.f = false;
+            else
+                rc = VERR_INVALID_PARAMETER;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_STRING:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_STRING;
+            pCfgItem->Val.u.psz = RTStrDup(pszVal);
+            if (!pCfgItem->Val.u.psz)
+                rc = VERR_NO_STR_MEMORY;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_UINT8:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_UINT8;
+
+            uint64_t u64;
+            rc = utsDoGadgetCreateCfgParseUInt(pszVal, UINT8_MAX, &u64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.u8 = (uint8_t)u64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_UINT16:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_UINT16;
+
+            uint64_t u64;
+            rc = utsDoGadgetCreateCfgParseUInt(pszVal, UINT16_MAX, &u64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.u16 = (uint16_t)u64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_UINT32:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_UINT32;
+
+            uint64_t u64;
+            rc = utsDoGadgetCreateCfgParseUInt(pszVal, UINT32_MAX, &u64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.u32 = (uint32_t)u64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_UINT64:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_UINT64;
+            rc = utsDoGadgetCreateCfgParseUInt(pszVal, UINT64_MAX, &pCfgItem->Val.u.u64);
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_INT8:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_INT8;
+
+            int64_t i64;
+            rc = utsDoGadgetCreateCfgParseInt(pszVal, INT8_MIN, INT8_MAX, &i64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.i8 = (int8_t)i64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_INT16:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_INT16;
+
+            int64_t i64;
+            rc = utsDoGadgetCreateCfgParseInt(pszVal, INT16_MIN, INT16_MAX, &i64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.i16 = (int16_t)i64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_INT32:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_INT32;
+
+            int64_t i64;
+            rc = utsDoGadgetCreateCfgParseInt(pszVal, INT32_MIN, INT32_MAX, &i64);
+            if (RT_SUCCESS(rc))
+                pCfgItem->Val.u.i32 = (int32_t)i64;
+            break;
+        }
+        case UTSPKT_GDGT_CFG_ITEM_TYPE_INT64:
+        {
+            pCfgItem->Val.enmType = UTSGADGETCFGTYPE_INT64;
+            rc = utsDoGadgetCreateCfgParseInt(pszVal, INT64_MIN, INT64_MAX, &pCfgItem->Val.u.i64);
+            break;
+        }
+        default:
+            rc = VERR_INVALID_PARAMETER;
+    }
+
+    return rc;
+}
+
+/**
+ * Creates the configuration from the given GADGET CREATE packet.
+ *
+ * @returns IPRT status code.
+ * @param   pCfgItem            The first config item header in the request packet.
+ * @param   cCfgItems           Number of config items in the packet to parse.
+ * @param   cbPkt               Number of bytes left in the packet for the config data.
+ * @param   paCfg               The array of configuration items to fill.
+ */
+static int utsDoGadgetCreateFillCfg(PUTSPKTREQGDGTCTORCFGITEM pCfgItem, unsigned cCfgItems,
+                                    size_t cbPkt, PUTSGADGETCFGITEM paCfg)
+{
+    int rc = VINF_SUCCESS;
+    unsigned idxCfg = 0;
+
+    while (   RT_SUCCESS(rc)
+           && cCfgItems
+           && cbPkt)
+    {
+        if (cbPkt >= sizeof(UTSPKTREQGDGTCTORCFGITEM))
+        {
+            cbPkt -= sizeof(UTSPKTREQGDGTCTORCFGITEM);
+            if (pCfgItem->u32KeySize + pCfgItem->u32ValSize >= cbPkt)
+            {
+                const char *pszKey = (const char *)(pCfgItem + 1);
+                const char *pszVal = pszKey + pCfgItem->u32KeySize;
+
+                /* Validate termination. */
+                if (   *(pszKey + pCfgItem->u32KeySize - 1) != '\0'
+                    || *(pszVal + pCfgItem->u32ValSize - 1) != '\0')
+                    rc = VERR_INVALID_PARAMETER;
+                else
+                {
+                    paCfg[idxCfg].pszKey = RTStrDup(pszKey);
+
+                    rc = utsDoGadgetCreateCfgParseItem(&paCfg[idxCfg], pCfgItem->u32Type, pszVal);
+                    if (RT_SUCCESS(rc))
+                    {
+                        cbPkt -= pCfgItem->u32KeySize + pCfgItem->u32ValSize;
+                        cCfgItems--;
+                        idxCfg++;
+                        pCfgItem = (PUTSPKTREQGDGTCTORCFGITEM)(pszVal + pCfgItem->u32ValSize);
+                    }
+                }
+            }
+            else
+                rc = VERR_INVALID_PARAMETER;
+        }
+        else
+            rc = VERR_INVALID_PARAMETER;
+    }
+
+    return rc;
+}
+
+/**
+ * Verifies and acknowledges a "BYE" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The howdy packet.
+ */
+static int utsDoBye(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    int rc;
+    if (pPktHdr->cb == sizeof(UTSPKTHDR))
+        rc = utsReplyAck(pClient, pPktHdr);
+    else
+        rc = utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTHDR));
+    return rc;
+}
+
+/**
+ * Verifies and acknowledges a "HOWDY" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The howdy packet.
+ */
+static int utsDoHowdy(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    int rc = VINF_SUCCESS;
+
+    if (pPktHdr->cb != sizeof(UTSPKTREQHOWDY))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTREQHOWDY));
+
+    if (pClient->enmState != UTSCLIENTSTATE_INITIALISING)
+        return utsReplyInvalidState(pClient, pPktHdr);
+
+    PUTSPKTREQHOWDY pReq = (PUTSPKTREQHOWDY)pPktHdr;
+
+    if (pReq->uVersion != UTS_PROTOCOL_VS)
+        return utsReplyRC(pClient, pPktHdr, VERR_VERSION_MISMATCH, "The given version %#x is not supported", pReq->uVersion);
+
+    /* Verify hostname string. */
+    if (pReq->cchHostname >= sizeof(pReq->achHostname))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(pReq->achHostname) - 1);
+
+    if (pReq->achHostname[pReq->cchHostname] != '\0')
+        return utsReplyBadStrTermination(pClient, pPktHdr);
+
+    /* Extract string. */
+    pClient->pszHostname = RTStrDup(&pReq->achHostname[0]);
+    if (!pClient->pszHostname)
+        return utsReplyRC(pClient, pPktHdr, VERR_NO_MEMORY, "Failed to allocate memory for the hostname string");
+
+    if (pReq->fUsbConn & UTSPKT_HOWDY_CONN_F_PHYSICAL)
+        return utsReplyRC(pClient, pPktHdr, VERR_NOT_SUPPORTED, "Physical connections are not yet supported");
+
+    if (pReq->fUsbConn & UTSPKT_HOWDY_CONN_F_USBIP)
+    {
+        /* Set up the USB/IP server, find an unused port we can start the server on. */
+        UTSGADGETCFGITEM aCfg[2];
+
+        uint16_t uPort = g_uUsbIpPortNext;
+
+        if (g_uUsbIpPortNext == g_uUsbIpPortLast)
+            g_uUsbIpPortNext = g_uUsbIpPortFirst;
+        else
+            g_uUsbIpPortNext++;
+
+        aCfg[0].pszKey      = "UsbIp/Port";
+        aCfg[0].Val.enmType = UTSGADGETCFGTYPE_UINT16;
+        aCfg[0].Val.u.u16   = uPort;
+        aCfg[1].pszKey      = NULL;
+
+        rc = utsGadgetHostCreate(UTSGADGETHOSTTYPE_USBIP, &aCfg[0], &pClient->hGadgetHost);
+        if (RT_SUCCESS(rc))
+        {
+            /* Send the reply with the configured USB/IP port. */
+            UTSPKTREPHOWDY Rep;
+
+            RT_ZERO(Rep);
+
+            Rep.uVersion         = UTS_PROTOCOL_VS;
+            Rep.fUsbConn         = UTSPKT_HOWDY_CONN_F_USBIP;
+            Rep.uUsbIpPort       = uPort;
+            Rep.cUsbIpDevices    = 1;
+            Rep.cPhysicalDevices = 0;
+
+            rc = utsReplyInternal(pClient, &Rep.Sts, "ACK     ", sizeof(Rep) - sizeof(UTSPKTSTS));
+            if (RT_SUCCESS(rc))
+            {
+                g_pTransport->pfnNotifyHowdy(pClient->pTransportClient);
+                pClient->enmState = UTSCLIENTSTATE_READY;
+                RTDirRemoveRecursive(g_szScratchPath, RTDIRRMREC_F_CONTENT_ONLY);
+            }
+        }
+        else
+            return utsReplyRC(pClient, pPktHdr, rc, "Creating the USB/IP gadget host failed");
+    }
+    else
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_PARAMETER, "No access method requested");
+
+    return rc;
+}
+
+/**
+ * Verifies and processes a "GADGET CREATE" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The gadget create packet.
+ */
+static int utsDoGadgetCreate(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    int rc = VINF_SUCCESS;
+
+    if (pPktHdr->cb < sizeof(UTSPKTREQGDGTCTOR))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTREQGDGTCTOR));
+
+    if (   pClient->enmState != UTSCLIENTSTATE_READY
+        || pClient->hGadgetHost == NIL_UTSGADGETHOST)
+        return utsReplyInvalidState(pClient, pPktHdr);
+
+    PUTSPKTREQGDGTCTOR pReq = (PUTSPKTREQGDGTCTOR)pPktHdr;
+
+    if (pReq->u32GdgtType != UTSPKT_GDGT_CREATE_TYPE_TEST)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_PARAMETER, "The given gadget type is not supported");
+
+    if (pReq->u32GdgtAccess != UTSPKT_GDGT_CREATE_ACCESS_USBIP)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_PARAMETER, "The given gadget access method is not supported");
+
+    PUTSGADGETCFGITEM paCfg = NULL;
+    if (pReq->u32CfgItems > 0)
+    {
+        paCfg = (PUTSGADGETCFGITEM)RTMemAllocZ((pReq->u32CfgItems + 1) * sizeof(UTSGADGETCFGITEM));
+        if (RT_UNLIKELY(!paCfg))
+            return utsReplyRC(pClient, pPktHdr, VERR_NO_MEMORY, "Failed to allocate memory for configration items");
+
+        rc = utsDoGadgetCreateFillCfg((PUTSPKTREQGDGTCTORCFGITEM)(pReq + 1), pReq->u32CfgItems,
+                                      pPktHdr->cb - sizeof(UTSPKTREQGDGTCTOR), paCfg);
+        if (RT_FAILURE(rc))
+        {
+            RTMemFree(paCfg);
+            return utsReplyRC(pClient, pPktHdr, rc, "Failed to parse configuration");
+        }
+    }
+
+    rc = utsGadgetCreate(pClient->hGadgetHost, UTSGADGETCLASS_TEST, paCfg, &pClient->hGadget);
+    if (RT_SUCCESS(rc))
+    {
+        UTSPKTREPGDGTCTOR Rep;
+        RT_ZERO(Rep);
+
+        Rep.idGadget = 0;
+        Rep.u32BusId = utsGadgetGetBusId(pClient->hGadget);
+        Rep.u32DevId = utsGadgetGetDevId(pClient->hGadget);
+        rc = utsReplyInternal(pClient, &Rep.Sts, "ACK     ", sizeof(Rep) - sizeof(UTSPKTSTS));
+    }
+    else
+        rc = utsReplyRC(pClient, pPktHdr, rc, "Failed to create gadget with %Rrc\n", rc);
+
+    return rc;
+}
+
+/**
+ * Verifies and processes a "GADGET DESTROY" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The gadget destroy packet.
+ */
+static int utsDoGadgetDestroy(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    if (pPktHdr->cb != sizeof(UTSPKTREQGDGTDTOR))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTREQGDGTDTOR));
+
+    if (   pClient->enmState != UTSCLIENTSTATE_READY
+        || pClient->hGadgetHost == NIL_UTSGADGETHOST)
+        return utsReplyInvalidState(pClient, pPktHdr);
+
+    PUTSPKTREQGDGTDTOR pReq = (PUTSPKTREQGDGTDTOR)pPktHdr;
+
+    if (pReq->idGadget != 0)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_HANDLE, "The given gadget handle is invalid");
+    if (pClient->hGadget == NIL_UTSGADGET)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_STATE, "The gadget is not set up");
+
+    utsGadgetRelease(pClient->hGadget);
+    pClient->hGadget = NIL_UTSGADGET;
+
+    return utsReplyAck(pClient, pPktHdr);
+}
+
+/**
+ * Verifies and processes a "GADGET CONNECT" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The gadget connect packet.
+ */
+static int utsDoGadgetConnect(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    if (pPktHdr->cb != sizeof(UTSPKTREQGDGTCNCT))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTREQGDGTCNCT));
+
+    if (   pClient->enmState != UTSCLIENTSTATE_READY
+        || pClient->hGadgetHost == NIL_UTSGADGETHOST)
+        return utsReplyInvalidState(pClient, pPktHdr);
+
+    PUTSPKTREQGDGTCNCT pReq = (PUTSPKTREQGDGTCNCT)pPktHdr;
+
+    if (pReq->idGadget != 0)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_HANDLE, "The given gadget handle is invalid");
+    if (pClient->hGadget == NIL_UTSGADGET)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_STATE, "The gadget is not set up");
+
+    int rc = utsGadgetConnect(pClient->hGadget);
+    if (RT_SUCCESS(rc))
+        rc = utsReplyAck(pClient, pPktHdr);
+    else
+        rc = utsReplyRC(pClient, pPktHdr, rc, "Failed to connect the gadget");
+
+    return rc;
+}
+
+/**
+ * Verifies and processes a "GADGET DISCONNECT" request.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure.
+ * @param   pPktHdr             The gadget disconnect packet.
+ */
+static int utsDoGadgetDisconnect(PUTSCLIENT pClient, PCUTSPKTHDR pPktHdr)
+{
+    if (pPktHdr->cb != sizeof(UTSPKTREQGDGTDCNT))
+        return utsReplyBadSize(pClient, pPktHdr, sizeof(UTSPKTREQGDGTDCNT));
+
+    if (   pClient->enmState != UTSCLIENTSTATE_READY
+        || pClient->hGadgetHost == NIL_UTSGADGETHOST)
+        return utsReplyInvalidState(pClient, pPktHdr);
+
+    PUTSPKTREQGDGTDCNT pReq = (PUTSPKTREQGDGTDCNT)pPktHdr;
+
+    if (pReq->idGadget != 0)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_HANDLE, "The given gadget handle is invalid");
+    if (pClient->hGadget == NIL_UTSGADGET)
+        return utsReplyRC(pClient, pPktHdr, VERR_INVALID_STATE, "The gadget is not set up");
+
+    int rc = utsGadgetDisconnect(pClient->hGadget);
+    if (RT_SUCCESS(rc))
+        rc = utsReplyAck(pClient, pPktHdr);
+    else
+        rc = utsReplyRC(pClient, pPktHdr, rc, "Failed to disconnect the gadget");
+
+    return rc;
+}
+
+/**
+ * Main request processing routine for each client.
+ *
+ * @returns IPRT status code.
+ * @param   pClient             The UTS client structure sending the request.
+ */
+static int utsClientReqProcess(PUTSCLIENT pClient)
+{
+    /*
+     * Read client command packet and process it.
+     */
+    PUTSPKTHDR pPktHdr = NULL;
+    int rc = utsRecvPkt(pClient, &pPktHdr, true /*fAutoRetryOnFailure*/);
+    if (RT_FAILURE(rc))
+        return rc;
+
+    /*
+     * Do a string switch on the opcode bit.
+     */
+    /* Connection: */
+    if (     utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_HOWDY))
+        rc = utsDoHowdy(pClient, pPktHdr);
+    else if (utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_BYE))
+        rc = utsDoBye(pClient, pPktHdr);
+    /* Gadget API. */
+    else if (utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_GADGET_CREATE))
+        rc = utsDoGadgetCreate(pClient, pPktHdr);
+    else if (utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_GADGET_DESTROY))
+        rc = utsDoGadgetDestroy(pClient, pPktHdr);
+    else if (utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_GADGET_CONNECT))
+        rc = utsDoGadgetConnect(pClient, pPktHdr);
+    else if (utsIsSameOpcode(pPktHdr, UTSPKT_OPCODE_GADGET_DISCONNECT))
+        rc = utsDoGadgetDisconnect(pClient, pPktHdr);
+    /* Misc: */
+    else
+        rc = utsReplyUnknown(pClient, pPktHdr);
+
+    RTMemFree(pPktHdr);
+
+    return rc;
+}
+
+/**
+ * Destroys a client instance.
+ *
+ * @returns nothing.
+ * @param   pClient             The UTS client structure.
+ */
+static void utsClientDestroy(PUTSCLIENT pClient)
+{
+    if (pClient->pszHostname)
+        RTStrFree(pClient->pszHostname);
+    if (pClient->hGadget != NIL_UTSGADGET)
+        utsGadgetRelease(pClient->hGadget);
+    if (pClient->hGadgetHost != NIL_UTSGADGETHOST)
+        utsGadgetHostRelease(pClient->hGadgetHost);
+    RTMemFree(pClient);
+}
+
+/**
+ * The main thread worker serving the clients.
+ */
+static DECLCALLBACK(int) utsClientWorker(RTTHREAD hThread, void *pvUser)
+{
+    RT_NOREF2(hThread, pvUser);
+    unsigned    cClientsMax = 0;
+    unsigned    cClientsCur = 0;
+    PUTSCLIENT *papClients  = NULL;
+    RTPOLLSET   hPollSet;
+
+    int rc = RTPollSetCreate(&hPollSet);
+    if (RT_FAILURE(rc))
+        return rc;
+
+    /* Add the pipe to the poll set. */
+    rc = RTPollSetAddPipe(hPollSet, g_hPipeR, RTPOLL_EVT_READ | RTPOLL_EVT_ERROR, 0);
+    if (RT_SUCCESS(rc))
+    {
+        while (!g_fTerminate)
+        {
+            uint32_t fEvts;
+            uint32_t uId;
+            rc = RTPoll(hPollSet, RT_INDEFINITE_WAIT, &fEvts, &uId);
+            if (RT_SUCCESS(rc))
+            {
+                if (uId == 0)
+                {
+                    if (fEvts & RTPOLL_EVT_ERROR)
+                        break;
+
+                    /* We got woken up because of a new client. */
+                    Assert(fEvts & RTPOLL_EVT_READ);
+
+                    uint8_t bRead;
+                    size_t cbRead = 0;
+                    rc = RTPipeRead(g_hPipeR, &bRead, 1, &cbRead);
+                    AssertRC(rc);
+
+                    RTCritSectEnter(&g_CritSectClients);
+                    /* Walk the list and add all new clients. */
+                    PUTSCLIENT pIt, pItNext;
+                    RTListForEachSafe(&g_LstClientsNew, pIt, pItNext, UTSCLIENT, NdLst)
+                    {
+                        RTListNodeRemove(&pIt->NdLst);
+                        Assert(cClientsCur <= cClientsMax);
+                        if (cClientsCur == cClientsMax)
+                        {
+                            /* Realloc to accommodate for the new clients. */
+                            PUTSCLIENT *papClientsNew = (PUTSCLIENT *)RTMemRealloc(papClients, (cClientsMax + 10) * sizeof(PUTSCLIENT));
+                            if (RT_LIKELY(papClientsNew))
+                            {
+                                cClientsMax += 10;
+                                papClients = papClientsNew;
+                            }
+                        }
+
+                        if (cClientsCur < cClientsMax)
+                        {
+                            /* Find a free slot in the client array. */
+                            unsigned idxSlt = 0;
+                            while (   idxSlt < cClientsMax
+                                   && papClients[idxSlt] != NULL)
+                                idxSlt++;
+
+                            rc = g_pTransport->pfnPollSetAdd(hPollSet, pIt->pTransportClient, idxSlt + 1);
+                            if (RT_SUCCESS(rc))
+                            {
+                                cClientsCur++;
+                                papClients[idxSlt] = pIt;
+                            }
+                            else
+                            {
+                                g_pTransport->pfnNotifyBye(pIt->pTransportClient);
+                                utsClientDestroy(pIt);
+                            }
+                        }
+                        else
+                        {
+                            g_pTransport->pfnNotifyBye(pIt->pTransportClient);
+                            utsClientDestroy(pIt);
+                        }
+                    }
+                    RTCritSectLeave(&g_CritSectClients);
+                }
+                else
+                {
+                    /* Client sends a request, pick the right client and process it. */
+                    PUTSCLIENT pClient = papClients[uId - 1];
+                    AssertPtr(pClient);
+                    if (fEvts & RTPOLL_EVT_READ)
+                        rc = utsClientReqProcess(pClient);
+
+                    if (   (fEvts & RTPOLL_EVT_ERROR)
+                        || RT_FAILURE(rc))
+                    {
+                        /* Close connection and remove client from array. */
+                        rc = g_pTransport->pfnPollSetRemove(hPollSet, pClient->pTransportClient, uId);
+                        AssertRC(rc);
+
+                        g_pTransport->pfnNotifyBye(pClient->pTransportClient);
+                        papClients[uId - 1] = NULL;
+                        cClientsCur--;
+                        utsClientDestroy(pClient);
+                    }
+                }
+            }
+        }
+    }
+
+    RTPollSetDestroy(hPollSet);
+
+    return rc;
+}
+
+/**
+ * The main loop.
+ *
+ * @returns exit code.
+ */
+static RTEXITCODE utsMainLoop(void)
+{
+    RTEXITCODE enmExitCode = RTEXITCODE_SUCCESS;
+    while (!g_fTerminate)
+    {
+        /*
+         * Wait for new connection and spin off a new thread
+         * for every new client.
+         */
+        PUTSTRANSPORTCLIENT pTransportClient;
+        int rc = g_pTransport->pfnWaitForConnect(&pTransportClient);
+        if (RT_FAILURE(rc))
+            continue;
+
+        /*
+         * New connection, create new client structure and spin of
+         * the request handling thread.
+         */
+        PUTSCLIENT pClient = (PUTSCLIENT)RTMemAllocZ(sizeof(UTSCLIENT));
+        if (RT_LIKELY(pClient))
+        {
+            pClient->enmState         = UTSCLIENTSTATE_INITIALISING;
+            pClient->pTransportClient = pTransportClient;
+            pClient->pszHostname      = NULL;
+            pClient->hGadgetHost      = NIL_UTSGADGETHOST;
+            pClient->hGadget          = NIL_UTSGADGET;
+
+            /* Add client to the new list and inform the worker thread. */
+            RTCritSectEnter(&g_CritSectClients);
+            RTListAppend(&g_LstClientsNew, &pClient->NdLst);
+            RTCritSectLeave(&g_CritSectClients);
+
+            size_t cbWritten = 0;
+            rc = RTPipeWrite(g_hPipeW, "", 1, &cbWritten);
+            if (RT_FAILURE(rc))
+                RTMsgError("Failed to inform worker thread of a new client");
+        }
+        else
+        {
+            RTMsgError("Creating new client structure failed with out of memory error\n");
+            g_pTransport->pfnNotifyBye(pTransportClient);
+        }
+
+
+    }
+
+    return enmExitCode;
+}
+
+/**
+ * Initializes the global UTS state.
+ *
+ * @returns IPRT status code.
+ */
+static int utsInit(void)
+{
+    int rc = VINF_SUCCESS;
+    PRTERRINFO pErrInfo = NULL;
+
+    RTListInit(&g_LstClientsNew);
+
+    rc = RTJsonParseFromFile(&g_hCfgJson, g_szCfgPath, pErrInfo);
+    if (RT_SUCCESS(rc))
+    {
+        rc = utsPlatformInit();
+        if (RT_SUCCESS(rc))
+        {
+            rc = RTCritSectInit(&g_CritSectClients);
+            if (RT_SUCCESS(rc))
+            {
+                rc = RTPipeCreate(&g_hPipeR, &g_hPipeW, 0);
+                if (RT_SUCCESS(rc))
+                {
+                    /* Spin off the thread serving connections. */
+                    rc = RTThreadCreate(&g_hThreadServing, utsClientWorker, NULL, 0, RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE,
+                                        "USBTSTSRV");
+                    if (RT_SUCCESS(rc))
+                        return VINF_SUCCESS;
+                    else
+                        RTMsgError("Creating the client worker thread failed with %Rrc\n", rc);
+
+                    RTPipeClose(g_hPipeR);
+                    RTPipeClose(g_hPipeW);
+                }
+                else
+                    RTMsgError("Creating communications pipe failed with %Rrc\n", rc);
+
+                RTCritSectDelete(&g_CritSectClients);
+            }
+            else
+                RTMsgError("Creating global critical section failed with %Rrc\n", rc);
+
+            RTJsonValueRelease(g_hCfgJson);
+        }
+        else
+            RTMsgError("Initializing the platform failed with %Rrc\n", rc);
+    }
+    else
+    {
+        if (RTErrInfoIsSet(pErrInfo))
+        {
+            RTMsgError("Failed to parse config with detailed error: %s (%Rrc)\n",
+                       pErrInfo->pszMsg, pErrInfo->rc);
+            RTErrInfoFree(pErrInfo);
+        }
+        else
+            RTMsgError("Failed to parse config with unknown error (%Rrc)\n", rc);
+    }
+
+    return rc;
+}
+
+/**
+ * Determines the default configuration.
+ */
+static void utsSetDefaults(void)
+{
+    /*
+     * OS and ARCH.
+     */
+    AssertCompile(sizeof(KBUILD_TARGET) <= sizeof(g_szOsShortName));
+    strcpy(g_szOsShortName, KBUILD_TARGET);
+
+    AssertCompile(sizeof(KBUILD_TARGET_ARCH) <= sizeof(g_szArchShortName));
+    strcpy(g_szArchShortName, KBUILD_TARGET_ARCH);
+
+    AssertCompile(sizeof(KBUILD_TARGET) + sizeof(KBUILD_TARGET_ARCH) <= sizeof(g_szOsDotArchShortName));
+    strcpy(g_szOsDotArchShortName, KBUILD_TARGET);
+    g_szOsDotArchShortName[sizeof(KBUILD_TARGET) - 1] = '.';
+    strcpy(&g_szOsDotArchShortName[sizeof(KBUILD_TARGET)], KBUILD_TARGET_ARCH);
+
+    AssertCompile(sizeof(KBUILD_TARGET) + sizeof(KBUILD_TARGET_ARCH) <= sizeof(g_szOsSlashArchShortName));
+    strcpy(g_szOsSlashArchShortName, KBUILD_TARGET);
+    g_szOsSlashArchShortName[sizeof(KBUILD_TARGET) - 1] = '/';
+    strcpy(&g_szOsSlashArchShortName[sizeof(KBUILD_TARGET)], KBUILD_TARGET_ARCH);
+
+#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
+    strcpy(g_szExeSuff,    ".exe");
+    strcpy(g_szScriptSuff, ".cmd");
+#else
+    strcpy(g_szExeSuff,    "");
+    strcpy(g_szScriptSuff, ".sh");
+#endif
+
+    /*
+     * The CD/DVD-ROM location.
+     */
+    /** @todo do a better job here :-) */
+#ifdef RT_OS_WINDOWS
+    strcpy(g_szDefCdRomPath, "D:/");
+#elif defined(RT_OS_OS2)
+    strcpy(g_szDefCdRomPath, "D:/");
+#else
+    if (RTDirExists("/media"))
+        strcpy(g_szDefCdRomPath, "/media/cdrom");
+    else
+        strcpy(g_szDefCdRomPath, "/mnt/cdrom");
+#endif
+    strcpy(g_szCdRomPath, g_szDefCdRomPath);
+
+    /*
+     * Temporary directory.
+     */
+    int rc = RTPathTemp(g_szDefScratchPath, sizeof(g_szDefScratchPath));
+    if (RT_SUCCESS(rc))
+#if defined(RT_OS_OS2) || defined(RT_OS_WINDOWS) || defined(RT_OS_DOS)
+        rc = RTPathAppend(g_szDefScratchPath, sizeof(g_szDefScratchPath), "uts-XXXX.tmp");
+#else
+        rc = RTPathAppend(g_szDefScratchPath, sizeof(g_szDefScratchPath), "uts-XXXXXXXXX.tmp");
+#endif
+    if (RT_FAILURE(rc))
+    {
+        RTMsgError("RTPathTemp/Append failed when constructing scratch path: %Rrc\n", rc);
+        strcpy(g_szDefScratchPath, "/tmp/uts-XXXX.tmp");
+    }
+    strcpy(g_szScratchPath, g_szDefScratchPath);
+
+    /*
+     * Config file location.
+     */
+    /** @todo Improve */
+#if !defined(RT_OS_WINDOWS)
+    strcpy(g_szCfgPath, "/etc/uts.conf");
+#else
+    strcpy(g_szCfgPath, "");
+#endif
+
+    /*
+     * The default transporter is the first one.
+     */
+    g_pTransport = g_apTransports[0];
+}
+
+/**
+ * Prints the usage.
+ *
+ * @param   pStrm               Where to print it.
+ * @param   pszArgv0            The program name (argv[0]).
+ */
+static void utsUsage(PRTSTREAM pStrm, const char *pszArgv0)
+{
+    RTStrmPrintf(pStrm,
+                 "Usage: %Rbn [options]\n"
+                 "\n"
+                 "Options:\n"
+                 "  --config <path>\n"
+                 "      Where to load the config from\n"
+                 "  --cdrom <path>\n"
+                 "      Where the CD/DVD-ROM will be mounted.\n"
+                 "      Default: %s\n"
+                 "  --scratch <path>\n"
+                 "      Where to put scratch files.\n"
+                 "      Default: %s \n"
+                 ,
+                 pszArgv0,
+                 g_szDefCdRomPath,
+                 g_szDefScratchPath);
+    RTStrmPrintf(pStrm,
+                 "  --transport <name>\n"
+                 "      Use the specified transport layer, one of the following:\n");
+    for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+        RTStrmPrintf(pStrm, "          %s - %s\n", g_apTransports[i]->szName, g_apTransports[i]->pszDesc);
+    RTStrmPrintf(pStrm, "      Default: %s\n", g_pTransport->szName);
+    RTStrmPrintf(pStrm,
+                 "  --display-output, --no-display-output\n"
+                 "      Display the output and the result of all child processes.\n");
+    RTStrmPrintf(pStrm,
+                 "  --foreground\n"
+                 "      Don't daemonize, run in the foreground.\n");
+    RTStrmPrintf(pStrm,
+                 "  --help, -h, -?\n"
+                 "      Display this message and exit.\n"
+                 "  --version, -V\n"
+                 "      Display the version and exit.\n");
+
+    for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+        if (g_apTransports[i]->cOpts)
+        {
+            RTStrmPrintf(pStrm,
+                         "\n"
+                         "Options for %s:\n", g_apTransports[i]->szName);
+            g_apTransports[i]->pfnUsage(g_pStdOut);
+        }
+}
+
+/**
+ * Parses the arguments.
+ *
+ * @returns Exit code. Exit if this is non-zero or @a *pfExit is set.
+ * @param   argc                The number of arguments.
+ * @param   argv                The argument vector.
+ * @param   pfExit              For indicating exit when the exit code is zero.
+ */
+static RTEXITCODE utsParseArgv(int argc, char **argv, bool *pfExit)
+{
+    *pfExit = false;
+
+    /*
+     * Storage for locally handled options.
+     */
+    bool fDaemonize  = true;
+    bool fDaemonized = false;
+
+    /*
+     * Combine the base and transport layer option arrays.
+     */
+    static const RTGETOPTDEF s_aBaseOptions[] =
+    {
+        { "--config",           'C', RTGETOPT_REQ_STRING  },
+        { "--transport",        't', RTGETOPT_REQ_STRING  },
+        { "--cdrom",            'c', RTGETOPT_REQ_STRING  },
+        { "--scratch",          's', RTGETOPT_REQ_STRING  },
+        { "--display-output",   'd', RTGETOPT_REQ_NOTHING  },
+        { "--no-display-output",'D', RTGETOPT_REQ_NOTHING  },
+        { "--foreground",       'f', RTGETOPT_REQ_NOTHING  },
+        { "--daemonized",       'Z', RTGETOPT_REQ_NOTHING  },
+    };
+
+    size_t cOptions = RT_ELEMENTS(s_aBaseOptions);
+    for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+        cOptions += g_apTransports[i]->cOpts;
+
+    PRTGETOPTDEF paOptions = (PRTGETOPTDEF)alloca(cOptions * sizeof(RTGETOPTDEF));
+    if (!paOptions)
+        return RTMsgErrorExit(RTEXITCODE_FAILURE, "alloca failed\n");
+
+    memcpy(paOptions, s_aBaseOptions, sizeof(s_aBaseOptions));
+    cOptions = RT_ELEMENTS(s_aBaseOptions);
+    for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+    {
+        memcpy(&paOptions[cOptions], g_apTransports[i]->paOpts, g_apTransports[i]->cOpts * sizeof(RTGETOPTDEF));
+        cOptions += g_apTransports[i]->cOpts;
+    }
+
+    /*
+     * Parse the arguments.
+     */
+    RTGETOPTSTATE GetState;
+    int rc = RTGetOptInit(&GetState, argc, argv, paOptions, cOptions, 1, 0 /* fFlags */);
+    AssertRC(rc);
+
+    int ch;
+    RTGETOPTUNION Val;
+    while ((ch = RTGetOpt(&GetState, &Val)))
+    {
+        switch (ch)
+        {
+            case 'C':
+                rc = RTStrCopy(g_szCfgPath, sizeof(g_szCfgPath), Val.psz);
+                if (RT_FAILURE(rc))
+                    return RTMsgErrorExit(RTEXITCODE_FAILURE, "Config file path is path too long (%Rrc)\n", rc);
+                break;
+
+            case 'c':
+                rc = RTStrCopy(g_szCdRomPath, sizeof(g_szCdRomPath), Val.psz);
+                if (RT_FAILURE(rc))
+                    return RTMsgErrorExit(RTEXITCODE_FAILURE, "CD/DVD-ROM is path too long (%Rrc)\n", rc);
+                break;
+
+            case 'd':
+                g_fDisplayOutput = true;
+                break;
+
+            case 'D':
+                g_fDisplayOutput = false;
+                break;
+
+            case 'f':
+                fDaemonize = false;
+                break;
+
+            case 'h':
+                utsUsage(g_pStdOut, argv[0]);
+                *pfExit = true;
+                return RTEXITCODE_SUCCESS;
+
+            case 's':
+                rc = RTStrCopy(g_szScratchPath, sizeof(g_szScratchPath), Val.psz);
+                if (RT_FAILURE(rc))
+                    return RTMsgErrorExit(RTEXITCODE_FAILURE, "scratch path is too long (%Rrc)\n", rc);
+                break;
+
+            case 't':
+            {
+                PCUTSTRANSPORT pTransport = NULL;
+                for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+                    if (!strcmp(g_apTransports[i]->szName, Val.psz))
+                    {
+                        pTransport = g_apTransports[i];
+                        break;
+                    }
+                if (!pTransport)
+                    return RTMsgErrorExit(RTEXITCODE_SYNTAX, "Unknown transport layer name '%s'\n", Val.psz);
+                g_pTransport = pTransport;
+                break;
+            }
+
+            case 'V':
+                RTPrintf("$Revision: 127855 $\n");
+                *pfExit = true;
+                return RTEXITCODE_SUCCESS;
+
+            case 'Z':
+                fDaemonized = true;
+                fDaemonize = false;
+                break;
+
+            default:
+            {
+                rc = VERR_TRY_AGAIN;
+                for (size_t i = 0; i < RT_ELEMENTS(g_apTransports); i++)
+                    if (g_apTransports[i]->cOpts)
+                    {
+                        rc = g_apTransports[i]->pfnOption(ch, &Val);
+                        if (RT_SUCCESS(rc))
+                            break;
+                        if (rc != VERR_TRY_AGAIN)
+                        {
+                            *pfExit = true;
+                            return RTEXITCODE_SYNTAX;
+                        }
+                    }
+                if (rc == VERR_TRY_AGAIN)
+                {
+                    *pfExit = true;
+                    return RTGetOptPrintError(ch, &Val);
+                }
+                break;
+            }
+        }
+    }
+
+    /*
+     * Daemonize ourselves if asked to.
+     */
+    if (fDaemonize && !*pfExit)
+    {
+        rc = RTProcDaemonize(argv, "--daemonized");
+        if (RT_FAILURE(rc))
+            return RTMsgErrorExit(RTEXITCODE_FAILURE, "RTProcDaemonize: %Rrc\n", rc);
+        *pfExit = true;
+    }
+
+    return RTEXITCODE_SUCCESS;
+}
+
+
+int main(int argc, char **argv)
+{
+    /*
+     * Initialize the runtime.
+     */
+    int rc = RTR3InitExe(argc, &argv, 0);
+    if (RT_FAILURE(rc))
+        return RTMsgInitFailure(rc);
+
+    /*
+     * Determine defaults and parse the arguments.
+     */
+    utsSetDefaults();
+    bool fExit;
+    RTEXITCODE rcExit = utsParseArgv(argc, argv, &fExit);
+    if (rcExit != RTEXITCODE_SUCCESS || fExit)
+        return rcExit;
+
+    /*
+     * Initialize global state.
+     */
+    rc = utsInit();
+    if (RT_FAILURE(rc))
+        return RTEXITCODE_FAILURE;
+
+    /*
+     * Initialize the transport layer.
+     */
+    rc = g_pTransport->pfnInit();
+    if (RT_FAILURE(rc))
+        return RTEXITCODE_FAILURE;
+
+    /*
+     * Ok, start working
+     */
+    rcExit = utsMainLoop();
+
+    /*
+     * Cleanup.
+     */
+    g_pTransport->pfnTerm();
+
+    utsPlatformTerm();
+
+    return rcExit;
+}
+