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, 1351 insertions, 0 deletions

diff --git a/src/VBox/Runtime/common/fuzz/fuzzmastercmd.cpp b/src/VBox/Runtime/common/fuzz/fuzzmastercmd.cpp
new file mode 100644
index 00000000..b73ac07d
--- /dev/null
+++ b/src/VBox/Runtime/common/fuzz/fuzzmastercmd.cpp
@@ -0,0 +1,1351 @@
+/* $Id: fuzzmastercmd.cpp $ */
+/** @file
+ * IPRT - Fuzzing framework API, master command.
+ */
+
+/*
+ * Copyright (C) 2018-2019 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                                                                                                                 *
+*********************************************************************************************************************************/
+#include <iprt/fuzz.h>
+#include "internal/iprt.h"
+
+#include <iprt/asm.h>
+#include <iprt/assert.h>
+#include <iprt/base64.h>
+#include <iprt/buildconfig.h>
+#include <iprt/ctype.h>
+#include <iprt/err.h>
+#include <iprt/file.h>
+#include <iprt/getopt.h>
+#include <iprt/json.h>
+#include <iprt/list.h>
+#include <iprt/mem.h>
+#include <iprt/message.h>
+#include <iprt/path.h>
+#include <iprt/process.h>
+#include <iprt/stream.h>
+#include <iprt/string.h>
+#include <iprt/tcp.h>
+#include <iprt/thread.h>
+#include <iprt/vfs.h>
+#include <iprt/zip.h>
+
+
+/**
+ * A running fuzzer state.
+ */
+typedef struct RTFUZZRUN
+{
+    /** List node. */
+    RTLISTNODE                  NdFuzzed;
+    /** Identifier. */
+    char                        *pszId;
+    /** Number of processes. */
+    uint32_t                    cProcs;
+    /** The fuzzing observer state handle. */
+    RTFUZZOBS                   hFuzzObs;
+    /** Flag whether fuzzing was started. */
+    bool                        fStarted;
+} RTFUZZRUN;
+/** Pointer to a running fuzzer state. */
+typedef RTFUZZRUN *PRTFUZZRUN;
+
+
+/**
+ * Fuzzing master command state.
+ */
+typedef struct RTFUZZCMDMASTER
+{
+    /** List of running fuzzers. */
+    RTLISTANCHOR                LstFuzzed;
+    /** The port to listen on. */
+    uint16_t                    uPort;
+    /** The TCP server for requests. */
+    PRTTCPSERVER                hTcpSrv;
+    /** The root temp directory. */
+    const char                  *pszTmpDir;
+    /** The root results directory. */
+    const char                  *pszResultsDir;
+    /** Flag whether to shutdown. */
+    bool                        fShutdown;
+    /** The response message. */
+    char                        *pszResponse;
+} RTFUZZCMDMASTER;
+/** Pointer to a fuzzing master command state. */
+typedef RTFUZZCMDMASTER *PRTFUZZCMDMASTER;
+
+
+/**
+ * Wrapper around RTErrInfoSetV / RTMsgErrorV.
+ *
+ * @returns @a rc
+ * @param   pErrInfo            Extended error info.
+ * @param   rc                  The return code.
+ * @param   pszFormat           The message format.
+ * @param   ...                 The message format arguments.
+ */
+static int rtFuzzCmdMasterErrorRc(PRTERRINFO pErrInfo, int rc, const char *pszFormat, ...)
+{
+    va_list va;
+    va_start(va, pszFormat);
+    if (pErrInfo)
+        RTErrInfoSetV(pErrInfo, rc, pszFormat, va);
+    else
+        RTMsgErrorV(pszFormat, va);
+    va_end(va);
+    return rc;
+}
+
+
+/**
+ * Returns a running fuzzer state by the given ID.
+ *
+ * @returns Pointer to the running fuzzer state or NULL if not found.
+ * @param   pThis               The fuzzing master command state.
+ * @param   pszId               The ID to look for.
+ */
+static PRTFUZZRUN rtFuzzCmdMasterGetFuzzerById(PRTFUZZCMDMASTER pThis, const char *pszId)
+{
+    PRTFUZZRUN pIt = NULL;
+    RTListForEach(&pThis->LstFuzzed, pIt, RTFUZZRUN, NdFuzzed)
+    {
+        if (!RTStrCmp(pIt->pszId, pszId))
+            return pIt;
+    }
+
+    return NULL;
+}
+
+
+#if 0 /* unused */
+/**
+ * Processes and returns the value of the given config item in the JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   ppszStr             Where to store the pointer to the string on success.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessCfgString(char **ppszStr, const char *pszCfgItem, RTJSONVAL hJsonCfg, PRTERRINFO pErrInfo)
+{
+    int rc = RTJsonValueQueryStringByName(hJsonCfg, pszCfgItem, ppszStr);
+    if (RT_FAILURE(rc))
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query string value of \"%s\"", pszCfgItem);
+
+    return rc;
+}
+
+
+/**
+ * Processes and returns the value of the given config item in the JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pfVal               Where to store the config value on success.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessCfgBool(bool *pfVal, const char *pszCfgItem, RTJSONVAL hJsonCfg, PRTERRINFO pErrInfo)
+{
+    int rc = RTJsonValueQueryBooleanByName(hJsonCfg, pszCfgItem, pfVal);
+    if (RT_FAILURE(rc))
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query boolean value of \"%s\"", pszCfgItem);
+
+    return rc;
+}
+
+
+/**
+ * Processes and returns the value of the given config item in the JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pfVal               Where to store the config value on success.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   fDef                Default value if the item wasn't found.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessCfgBoolDef(bool *pfVal, const char *pszCfgItem, RTJSONVAL hJsonCfg, bool fDef, PRTERRINFO pErrInfo)
+{
+    int rc = RTJsonValueQueryBooleanByName(hJsonCfg, pszCfgItem, pfVal);
+    if (rc == VERR_NOT_FOUND)
+    {
+        *pfVal = fDef;
+        rc = VINF_SUCCESS;
+    }
+    else if (RT_FAILURE(rc))
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query boolean value of \"%s\"", pszCfgItem);
+
+    return rc;
+}
+#endif
+
+
+/**
+ * Processes and returns the value of the given config item in the JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pcbVal              Where to store the config value on success.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   cbDef               Default value if the item wasn't found.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessCfgSizeDef(size_t *pcbVal, const char *pszCfgItem, RTJSONVAL hJsonCfg, size_t cbDef, PRTERRINFO pErrInfo)
+{
+    *pcbVal = cbDef; /* Make GCC 6.3.0 happy. */
+
+    int64_t i64Val = 0;
+    int rc = RTJsonValueQueryIntegerByName(hJsonCfg, pszCfgItem, &i64Val);
+    if (rc == VERR_NOT_FOUND)
+        rc = VINF_SUCCESS;
+    else if (RT_FAILURE(rc))
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query size_t value of \"%s\"", pszCfgItem);
+    else if (i64Val < 0 || (size_t)i64Val != (uint64_t)i64Val)
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_OUT_OF_RANGE, "JSON request malformed: Integer \"%s\" is out of range", pszCfgItem);
+    else
+        *pcbVal = (size_t)i64Val;
+
+    return rc;
+}
+
+
+/**
+ * Processes and returns the value of the given config item in the JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pcbVal              Where to store the config value on success.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   cbDef               Default value if the item wasn't found.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessCfgU32Def(uint32_t *pu32Val, const char *pszCfgItem, RTJSONVAL hJsonCfg, uint32_t u32Def, PRTERRINFO pErrInfo)
+{
+    int64_t i64Val = 0;
+    int rc = RTJsonValueQueryIntegerByName(hJsonCfg, pszCfgItem, &i64Val);
+    if (rc == VERR_NOT_FOUND)
+    {
+        *pu32Val = u32Def;
+        rc = VINF_SUCCESS;
+    }
+    else if (RT_FAILURE(rc))
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query uint32_t value of \"%s\"", pszCfgItem);
+    else if (i64Val < 0 || (uint32_t)i64Val != (uint64_t)i64Val)
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_OUT_OF_RANGE, "JSON request malformed: Integer \"%s\" is out of range", pszCfgItem);
+    else
+        *pu32Val = (uint32_t)i64Val;
+
+    return rc;
+}
+
+
+/**
+ * Returns the configured input channel for the binary under test.
+ *
+ * @returns Selected input channel or RTFUZZOBSINPUTCHAN_INVALID if an error occurred.
+ * @param   pszCfgItem          The config item to resolve.
+ * @param   hJsonCfg            The JSON object containing the item.
+ * @param   enmChanDef          Default value if the item wasn't found.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static RTFUZZOBSINPUTCHAN rtFuzzCmdMasterFuzzRunProcessCfgGetInputChan(const char *pszCfgItem, RTJSONVAL hJsonCfg, RTFUZZOBSINPUTCHAN enmChanDef, PRTERRINFO pErrInfo)
+{
+    RTFUZZOBSINPUTCHAN enmInputChan = RTFUZZOBSINPUTCHAN_INVALID;
+
+    RTJSONVAL hJsonVal;
+    int rc = RTJsonValueQueryByName(hJsonCfg, pszCfgItem, &hJsonVal);
+    if (rc == VERR_NOT_FOUND)
+        enmInputChan = enmChanDef;
+    else if (RT_SUCCESS(rc))
+    {
+        const char *pszBinary = RTJsonValueGetString(hJsonVal);
+        if (pszBinary)
+        {
+            if (!RTStrCmp(pszBinary, "File"))
+                enmInputChan = RTFUZZOBSINPUTCHAN_FILE;
+            else if (!RTStrCmp(pszBinary, "Stdin"))
+                enmInputChan = RTFUZZOBSINPUTCHAN_STDIN;
+            else if (!RTStrCmp(pszBinary, "FuzzingAware"))
+                enmInputChan = RTFUZZOBSINPUTCHAN_FUZZING_AWARE_CLIENT;
+            else
+                rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_PARAMETER, "JSON request malformed: \"%s\" for \"%s\" is not known", pszCfgItem, pszBinary);
+        }
+        else
+            rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "JSON request malformed: \"%s\" is not a string", pszCfgItem);
+
+        RTJsonValueRelease(hJsonVal);
+    }
+    else
+        rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query \"%s\"", pszCfgItem);
+
+    return enmInputChan;
+}
+
+
+/**
+ * Processes binary related configs for the given fuzzing run.
+ *
+ * @returns IPRT status code.
+ * @param   pFuzzRun            The fuzzing run.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessBinaryCfg(PRTFUZZRUN pFuzzRun, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    RTJSONVAL hJsonVal;
+    int rc = RTJsonValueQueryByName(hJsonRoot, "BinaryPath", &hJsonVal);
+    if (RT_SUCCESS(rc))
+    {
+        const char *pszBinary = RTJsonValueGetString(hJsonVal);
+        if (RT_LIKELY(pszBinary))
+        {
+            RTFUZZOBSINPUTCHAN enmInputChan = rtFuzzCmdMasterFuzzRunProcessCfgGetInputChan("InputChannel", hJsonRoot, RTFUZZOBSINPUTCHAN_STDIN, pErrInfo);
+            if (enmInputChan != RTFUZZOBSINPUTCHAN_INVALID)
+            {
+                rc = RTFuzzObsSetTestBinary(pFuzzRun->hFuzzObs, pszBinary, enmInputChan);
+                if (RT_FAILURE(rc))
+                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Failed to add the binary path for the fuzzing run");
+            }
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "JSON request malformed: \"BinaryPath\" is not a string");
+        RTJsonValueRelease(hJsonVal);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to query value of \"BinaryPath\"");
+
+    return rc;
+}
+
+
+/**
+ * Processes argument related configs for the given fuzzing run.
+ *
+ * @returns IPRT status code.
+ * @param   pFuzzRun            The fuzzing run.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessArgCfg(PRTFUZZRUN pFuzzRun, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    RTJSONVAL hJsonValArgArray;
+    int rc = RTJsonValueQueryByName(hJsonRoot, "Arguments", &hJsonValArgArray);
+    if (RT_SUCCESS(rc))
+    {
+        unsigned cArgs = 0;
+        rc = RTJsonValueQueryArraySize(hJsonValArgArray, &cArgs);
+        if (RT_SUCCESS(rc))
+        {
+            if (cArgs > 0)
+            {
+                const char **papszArgs = (const char **)RTMemAllocZ(cArgs * sizeof(const char *));
+                RTJSONVAL *pahJsonVal = (RTJSONVAL *)RTMemAllocZ(cArgs * sizeof(RTJSONVAL));
+                if (RT_LIKELY(papszArgs && pahJsonVal))
+                {
+                    unsigned idx = 0;
+
+                    for (idx = 0; idx < cArgs && RT_SUCCESS(rc); idx++)
+                    {
+                        rc = RTJsonValueQueryByIndex(hJsonValArgArray, idx, &pahJsonVal[idx]);
+                        if (RT_SUCCESS(rc))
+                        {
+                            papszArgs[idx] = RTJsonValueGetString(pahJsonVal[idx]);
+                            if (RT_UNLIKELY(!papszArgs[idx]))
+                                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "Argument %u is not a string", idx);
+                        }
+                    }
+
+                    if (RT_SUCCESS(rc))
+                    {
+                        rc = RTFuzzObsSetTestBinaryArgs(pFuzzRun->hFuzzObs, papszArgs, cArgs);
+                        if (RT_FAILURE(rc))
+                            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Failed to set arguments for the fuzzing run");
+                    }
+
+                    /* Release queried values. */
+                    while (idx > 0)
+                    {
+                        RTJsonValueRelease(pahJsonVal[idx - 1]);
+                        idx--;
+                    }
+                }
+                else
+                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_NO_MEMORY, "Out of memory allocating memory for the argument vector");
+
+                if (papszArgs)
+                    RTMemFree(papszArgs);
+                if (pahJsonVal)
+                    RTMemFree(pahJsonVal);
+            }
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: \"Arguments\" is not an array");
+        RTJsonValueRelease(hJsonValArgArray);
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes the given seed and adds it to the input corpus.
+ *
+ * @returns IPRT status code.
+ * @param   hFuzzCtx            The fuzzing context handle.
+ * @param   pszCompression      Compression used for the seed.
+ * @param   pszSeed             The seed as a base64 encoded string.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessSeed(RTFUZZCTX hFuzzCtx, const char *pszCompression, const char *pszSeed, PRTERRINFO pErrInfo)
+{
+    int rc = VINF_SUCCESS;
+    ssize_t cbSeedDecoded = RTBase64DecodedSize(pszSeed, NULL);
+    if (cbSeedDecoded > 0)
+    {
+        uint8_t *pbSeedDecoded = (uint8_t *)RTMemAllocZ(cbSeedDecoded);
+        if (RT_LIKELY(pbSeedDecoded))
+        {
+            rc = RTBase64Decode(pszSeed, pbSeedDecoded, cbSeedDecoded, NULL, NULL);
+            if (RT_SUCCESS(rc))
+            {
+                /* Decompress if applicable. */
+                if (!RTStrICmp(pszCompression, "None"))
+                    rc = RTFuzzCtxCorpusInputAdd(hFuzzCtx, pbSeedDecoded, cbSeedDecoded);
+                else
+                {
+                    RTVFSIOSTREAM hVfsIosSeed;
+                    rc = RTVfsIoStrmFromBuffer(RTFILE_O_READ, pbSeedDecoded, cbSeedDecoded, &hVfsIosSeed);
+                    if (RT_SUCCESS(rc))
+                    {
+                        RTVFSIOSTREAM hVfsDecomp = NIL_RTVFSIOSTREAM;
+
+                        if (!RTStrICmp(pszCompression, "Gzip"))
+                            rc = RTZipGzipDecompressIoStream(hVfsIosSeed, RTZIPGZIPDECOMP_F_ALLOW_ZLIB_HDR, &hVfsDecomp);
+                        else
+                            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "Request error: Compression \"%s\" is not known", pszCompression);
+
+                        if (RT_SUCCESS(rc))
+                        {
+                            RTVFSFILE hVfsFile;
+                            rc = RTVfsMemFileCreate(hVfsDecomp, 2 * _1M, &hVfsFile);
+                            if (RT_SUCCESS(rc))
+                            {
+                                rc = RTVfsFileSeek(hVfsFile, 0, RTFILE_SEEK_BEGIN, NULL);
+                                if (RT_SUCCESS(rc))
+                                {
+                                    /* The VFS file contains the buffer for the seed now. */
+                                    rc = RTFuzzCtxCorpusInputAddFromVfsFile(hFuzzCtx, hVfsFile);
+                                    if (RT_FAILURE(rc))
+                                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to add input seed");
+                                    RTVfsFileRelease(hVfsFile);
+                                }
+                                else
+                                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "Request error: Failed to seek to the beginning of the seed");
+                            }
+                            else
+                                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "Request error: Failed to decompress input seed");
+
+                            RTVfsIoStrmRelease(hVfsDecomp);
+                        }
+
+                        RTVfsIoStrmRelease(hVfsIosSeed);
+                    }
+                    else
+                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to create I/O stream from seed buffer");
+                }
+            }
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to decode the seed string");
+
+            RTMemFree(pbSeedDecoded);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_NO_MEMORY, "Request error: Failed to allocate %zd bytes of memory for the seed", cbSeedDecoded);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "JSON request malformed: Couldn't find \"Seed\" doesn't contain a base64 encoded value");
+
+    return rc;
+}
+
+
+/**
+ * Processes a signle input seed for the given fuzzing run.
+ *
+ * @returns IPRT status code.
+ * @param   pFuzzRun            The fuzzing run.
+ * @param   hJsonSeed           The seed node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessInputSeedSingle(PRTFUZZRUN pFuzzRun, RTJSONVAL hJsonSeed, PRTERRINFO pErrInfo)
+{
+    RTFUZZCTX hFuzzCtx;
+    int rc = RTFuzzObsQueryCtx(pFuzzRun->hFuzzObs, &hFuzzCtx);
+    if (RT_SUCCESS(rc))
+    {
+        RTJSONVAL hJsonValComp;
+        rc = RTJsonValueQueryByName(hJsonSeed, "Compression", &hJsonValComp);
+        if (RT_SUCCESS(rc))
+        {
+            const char *pszCompression = RTJsonValueGetString(hJsonValComp);
+            if (RT_LIKELY(pszCompression))
+            {
+                RTJSONVAL hJsonValSeed;
+                rc = RTJsonValueQueryByName(hJsonSeed, "Seed", &hJsonValSeed);
+                if (RT_SUCCESS(rc))
+                {
+                    const char *pszSeed = RTJsonValueGetString(hJsonValSeed);
+                    if (RT_LIKELY(pszSeed))
+                        rc = rtFuzzCmdMasterFuzzRunProcessSeed(hFuzzCtx, pszCompression, pszSeed, pErrInfo);
+                    else
+                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "JSON request malformed: \"Seed\" value is not a string");
+
+                    RTJsonValueRelease(hJsonValSeed);
+                }
+                else
+                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Couldn't find \"Seed\" value");
+            }
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_INVALID_STATE, "JSON request malformed: \"Compression\" value is not a string");
+
+            RTJsonValueRelease(hJsonValComp);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Couldn't find \"Compression\" value");
+
+        RTFuzzCtxRelease(hFuzzCtx);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Failed to query fuzzing context from observer");
+
+    return rc;
+}
+
+
+/**
+ * Processes input seed related configs for the given fuzzing run.
+ *
+ * @returns IPRT status code.
+ * @param   pFuzzRun            The fuzzing run.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessInputSeeds(PRTFUZZRUN pFuzzRun, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    RTJSONVAL hJsonValSeedArray;
+    int rc = RTJsonValueQueryByName(hJsonRoot, "InputSeeds", &hJsonValSeedArray);
+    if (RT_SUCCESS(rc))
+    {
+        RTJSONIT hIt;
+        rc = RTJsonIteratorBegin(hJsonValSeedArray, &hIt);
+        if (RT_SUCCESS(rc))
+        {
+            RTJSONVAL hJsonInpSeed;
+            while (   RT_SUCCESS(rc)
+                   && RTJsonIteratorQueryValue(hIt, &hJsonInpSeed, NULL) != VERR_JSON_ITERATOR_END)
+            {
+                rc = rtFuzzCmdMasterFuzzRunProcessInputSeedSingle(pFuzzRun, hJsonInpSeed, pErrInfo);
+                RTJsonValueRelease(hJsonInpSeed);
+                if (RT_FAILURE(rc))
+                    break;
+                rc = RTJsonIteratorNext(hIt);
+            }
+
+            if (rc == VERR_JSON_ITERATOR_END)
+                rc = VINF_SUCCESS;
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Failed to create array iterator");
+
+        RTJsonValueRelease(hJsonValSeedArray);
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes miscellaneous config items.
+ *
+ * @returns IPRT status code.
+ * @param   pFuzzRun            The fuzzing run.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterFuzzRunProcessMiscCfg(PRTFUZZRUN pFuzzRun, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    size_t cbTmp;
+    int rc = rtFuzzCmdMasterFuzzRunProcessCfgSizeDef(&cbTmp, "InputSeedMax", hJsonRoot, 0, pErrInfo);
+    if (RT_SUCCESS(rc))
+    {
+        RTFUZZCTX hFuzzCtx;
+        rc = RTFuzzObsQueryCtx(pFuzzRun->hFuzzObs, &hFuzzCtx);
+        AssertRC(rc);
+
+        rc = RTFuzzCtxCfgSetInputSeedMaximum(hFuzzCtx, cbTmp);
+        if (RT_FAILURE(rc))
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to set maximum input seed size to %zu", cbTmp);
+    }
+
+    if (RT_SUCCESS(rc))
+        rc = rtFuzzCmdMasterFuzzRunProcessCfgU32Def(&pFuzzRun->cProcs, "FuzzingProcs", hJsonRoot, 0, pErrInfo);
+
+    return rc;
+}
+
+
+/**
+ * Creates a new fuzzing run with the given ID.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   pszId               The ID to use.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterCreateFuzzRunWithId(PRTFUZZCMDMASTER pThis, const char *pszId, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    int rc = VINF_SUCCESS;
+    PRTFUZZRUN pFuzzRun = (PRTFUZZRUN)RTMemAllocZ(sizeof(*pFuzzRun));
+    if (RT_LIKELY(pFuzzRun))
+    {
+        pFuzzRun->pszId = RTStrDup(pszId);
+        if (RT_LIKELY(pFuzzRun->pszId))
+        {
+            rc = RTFuzzObsCreate(&pFuzzRun->hFuzzObs);
+            if (RT_SUCCESS(rc))
+            {
+                rc = rtFuzzCmdMasterFuzzRunProcessBinaryCfg(pFuzzRun, hJsonRoot, pErrInfo);
+                if (RT_SUCCESS(rc))
+                    rc = rtFuzzCmdMasterFuzzRunProcessArgCfg(pFuzzRun, hJsonRoot, pErrInfo);
+                if (RT_SUCCESS(rc))
+                    rc = rtFuzzCmdMasterFuzzRunProcessInputSeeds(pFuzzRun, hJsonRoot, pErrInfo);
+                if (RT_SUCCESS(rc))
+                    rc = rtFuzzCmdMasterFuzzRunProcessMiscCfg(pFuzzRun, hJsonRoot, pErrInfo);
+                if (RT_SUCCESS(rc))
+                {
+                    /* Create temp directories. */
+                    char szTmpDir[RTPATH_MAX];
+                    rc = RTPathJoin(&szTmpDir[0], sizeof(szTmpDir), pThis->pszTmpDir, pFuzzRun->pszId);
+                    AssertRC(rc);
+                    rc = RTDirCreate(szTmpDir, 0700,   RTDIRCREATE_FLAGS_NOT_CONTENT_INDEXED_SET
+                                                     | RTDIRCREATE_FLAGS_NOT_CONTENT_INDEXED_NOT_CRITICAL);
+                    if (RT_SUCCESS(rc))
+                    {
+                        rc = RTFuzzObsSetTmpDirectory(pFuzzRun->hFuzzObs, szTmpDir);
+                        if (RT_SUCCESS(rc))
+                        {
+                            rc = RTPathJoin(&szTmpDir[0], sizeof(szTmpDir), pThis->pszResultsDir, pFuzzRun->pszId);
+                            AssertRC(rc);
+                            rc = RTDirCreate(szTmpDir, 0700,   RTDIRCREATE_FLAGS_NOT_CONTENT_INDEXED_SET
+                                                             | RTDIRCREATE_FLAGS_NOT_CONTENT_INDEXED_NOT_CRITICAL);
+                            if (RT_SUCCESS(rc))
+                            {
+                                rc = RTFuzzObsSetResultDirectory(pFuzzRun->hFuzzObs, szTmpDir);
+                                if (RT_SUCCESS(rc))
+                                {
+                                    /* Start fuzzing. */
+                                    RTListAppend(&pThis->LstFuzzed, &pFuzzRun->NdFuzzed);
+                                    rc = RTFuzzObsExecStart(pFuzzRun->hFuzzObs, pFuzzRun->cProcs);
+                                    if (RT_SUCCESS(rc))
+                                        pFuzzRun->fStarted = true;
+                                    else
+                                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to start fuzzing with %Rrc", rc);
+                                }
+                                else
+                                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to set results directory to %s", szTmpDir);
+                            }
+                            else
+                                rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to create results directory %s", szTmpDir);
+                        }
+                        else
+                            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to set temporary directory to %s", szTmpDir);
+                    }
+                    else
+                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to create temporary directory %s", szTmpDir);
+                }
+            }
+        }
+        else
+            rc = VERR_NO_STR_MEMORY;
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_NO_MEMORY, "Request error: Out of memory allocating the fuzzer state");
+
+    return rc;
+}
+
+
+/**
+ * Resolves the fuzzing run from the given ID config item and the given JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pszIdItem           The JSON item which contains the ID of the fuzzing run.
+ * @param   ppFuzzRun           Where to store the pointer to the fuzzing run on success.
+ */
+static int rtFuzzCmdMasterQueryFuzzRunFromJson(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, const char *pszIdItem, PRTERRINFO pErrInfo,
+                                               PRTFUZZRUN *ppFuzzRun)
+{
+    RTJSONVAL hJsonValId;
+    int rc = RTJsonValueQueryByName(hJsonRoot, pszIdItem, &hJsonValId);
+    if (RT_SUCCESS(rc))
+    {
+        const char *pszId = RTJsonValueGetString(hJsonValId);
+        if (pszId)
+        {
+            PRTFUZZRUN pFuzzRun = rtFuzzCmdMasterGetFuzzerById(pThis, pszId);
+            if (pFuzzRun)
+                *ppFuzzRun = pFuzzRun;
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_NOT_FOUND, "Request error: The ID \"%s\" wasn't found", pszId);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_JSON_VALUE_INVALID_TYPE, "JSON request malformed: \"Id\" is not a string value");
+
+        RTJsonValueRelease(hJsonValId);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Couldn't find \"Id\" value");
+    return rc;
+}
+
+
+/**
+ * Processes the "StartFuzzing" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonRoot           The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqStart(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    RTJSONVAL hJsonValId;
+    int rc = RTJsonValueQueryByName(hJsonRoot, "Id", &hJsonValId);
+    if (RT_SUCCESS(rc))
+    {
+        const char *pszId = RTJsonValueGetString(hJsonValId);
+        if (pszId)
+        {
+            PRTFUZZRUN pFuzzRun = rtFuzzCmdMasterGetFuzzerById(pThis, pszId);
+            if (!pFuzzRun)
+                rc = rtFuzzCmdMasterCreateFuzzRunWithId(pThis, pszId, hJsonRoot, pErrInfo);
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_ALREADY_EXISTS, "Request error: The ID \"%s\" is already registered", pszId);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_JSON_VALUE_INVALID_TYPE, "JSON request malformed: \"Id\" is not a string value");
+
+        RTJsonValueRelease(hJsonValId);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Couldn't find \"Id\" value");
+    return rc;
+}
+
+
+/**
+ * Processes the "StopFuzzing" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqStop(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    PRTFUZZRUN pFuzzRun;
+    int rc = rtFuzzCmdMasterQueryFuzzRunFromJson(pThis, hJsonRoot, "Id", pErrInfo, &pFuzzRun);
+    if (RT_SUCCESS(rc))
+    {
+        RTListNodeRemove(&pFuzzRun->NdFuzzed);
+        RTFuzzObsExecStop(pFuzzRun->hFuzzObs);
+        RTFuzzObsDestroy(pFuzzRun->hFuzzObs);
+        RTStrFree(pFuzzRun->pszId);
+        RTMemFree(pFuzzRun);
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes the "SuspendFuzzing" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqSuspend(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    PRTFUZZRUN pFuzzRun;
+    int rc = rtFuzzCmdMasterQueryFuzzRunFromJson(pThis, hJsonRoot, "Id", pErrInfo, &pFuzzRun);
+    if (RT_SUCCESS(rc))
+    {
+        if (pFuzzRun->fStarted)
+        {
+            rc = RTFuzzObsExecStop(pFuzzRun->hFuzzObs);
+            if (RT_SUCCESS(rc))
+                pFuzzRun->fStarted = false;
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Suspending the fuzzing process failed");
+        }
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes the "ResumeFuzzing" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqResume(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    PRTFUZZRUN pFuzzRun;
+    int rc = rtFuzzCmdMasterQueryFuzzRunFromJson(pThis, hJsonRoot, "Id", pErrInfo, &pFuzzRun);
+    if (RT_SUCCESS(rc))
+    {
+        if (!pFuzzRun->fStarted)
+        {
+            rc = rtFuzzCmdMasterFuzzRunProcessCfgU32Def(&pFuzzRun->cProcs, "FuzzingProcs", hJsonRoot, pFuzzRun->cProcs, pErrInfo);
+            if (RT_SUCCESS(rc))
+            {
+                rc = RTFuzzObsExecStart(pFuzzRun->hFuzzObs, pFuzzRun->cProcs);
+                if (RT_SUCCESS(rc))
+                    pFuzzRun->fStarted = true;
+                else
+                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Resuming the fuzzing process failed");
+            }
+        }
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes the "SaveFuzzingState" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqSaveState(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    PRTFUZZRUN pFuzzRun;
+    int rc = rtFuzzCmdMasterQueryFuzzRunFromJson(pThis, hJsonRoot, "Id", pErrInfo, &pFuzzRun);
+    if (RT_SUCCESS(rc))
+    {
+        /* Suspend fuzzing, save and resume if not stopped. */
+        if (pFuzzRun->fStarted)
+        {
+            rc = RTFuzzObsExecStop(pFuzzRun->hFuzzObs);
+            if (RT_FAILURE(rc))
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Suspending the fuzzing process failed");
+        }
+
+        if (RT_SUCCESS(rc))
+        {
+            RTFUZZCTX hFuzzCtx;
+            rc = RTFuzzObsQueryCtx(pFuzzRun->hFuzzObs, &hFuzzCtx);
+            AssertRC(rc);
+
+            void *pvState = NULL;
+            size_t cbState = 0;
+            rc = RTFuzzCtxStateExport(hFuzzCtx, &pvState, &cbState);
+            if (RT_SUCCESS(rc))
+            {
+                /* Encode to base64. */
+                size_t cbStateStr = RTBase64EncodedLength(cbState) + 1;
+                char *pszState = (char *)RTMemAllocZ(cbStateStr);
+                if (pszState)
+                {
+                    rc = RTBase64Encode(pvState, cbState, pszState, cbStateStr, &cbStateStr);
+                    if (RT_SUCCESS(rc))
+                    {
+                        /* Strip all new lines from the srting. */
+                        size_t offStr = 0;
+                        while (offStr < cbStateStr)
+                        {
+#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
+                            char *pszEol = strchr(&pszState[offStr], '\r');
+#else
+                            char *pszEol = strchr(&pszState[offStr], '\n');
+#endif
+                            if (pszEol)
+                            {
+                                offStr += pszEol - &pszState[offStr];
+                                memmove(pszEol, &pszEol[RTBASE64_EOL_SIZE], cbStateStr - offStr - RTBASE64_EOL_SIZE);
+                                cbStateStr -= RTBASE64_EOL_SIZE;
+                            }
+                            else
+                                break;
+                        }
+
+                        const char s_szState[] = "{ \"State\": %s }";
+                        pThis->pszResponse = RTStrAPrintf2(s_szState, pszState);
+                        if (RT_UNLIKELY(!pThis->pszResponse))
+                            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_BUFFER_OVERFLOW, "Request error: Response data buffer overflow", rc);
+                    }
+                    else
+                        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to encode the state as a base64 string");
+                    RTMemFree(pszState);
+                }
+                else
+                    rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_NO_STR_MEMORY, "Request error: Failed to allocate a state string for the response");
+                RTMemFree(pvState);
+            }
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Exporting the state failed");
+        }
+
+        if (pFuzzRun->fStarted)
+        {
+            int rc2 = RTFuzzObsExecStart(pFuzzRun->hFuzzObs, pFuzzRun->cProcs);
+            if (RT_FAILURE(rc2))
+                rtFuzzCmdMasterErrorRc(pErrInfo, rc2, "Request error: Resuming the fuzzing process failed");
+        }
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes the "QueryStats" request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReqQueryStats(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    PRTFUZZRUN pFuzzRun;
+    int rc = rtFuzzCmdMasterQueryFuzzRunFromJson(pThis, hJsonRoot, "Id", pErrInfo, &pFuzzRun);
+    if (RT_SUCCESS(rc))
+    {
+        RTFUZZOBSSTATS Stats;
+        rc = RTFuzzObsQueryStats(pFuzzRun->hFuzzObs, &Stats);
+        if (RT_SUCCESS(rc))
+        {
+            const char s_szStats[] = "{ \"FuzzedInputsPerSec\": %u\n"
+                                     "  \"FuzzedInputs\":       %u\n"
+                                     "  \"FuzzedInputsHang\":   %u\n"
+                                     "  \"FuzzedInputsCrash\":   %u\n}";
+            pThis->pszResponse = RTStrAPrintf2(s_szStats, Stats.cFuzzedInputsPerSec,
+                                               Stats.cFuzzedInputs, Stats.cFuzzedInputsHang, Stats.cFuzzedInputsCrash);
+            if (RT_UNLIKELY(!pThis->pszResponse))
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_BUFFER_OVERFLOW, "Request error: Response data buffer overflow", rc);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "Request error: Failed to query fuzzing statistics with %Rrc", rc);
+    }
+
+    return rc;
+}
+
+
+/**
+ * Processes a JSON request.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   hJsonValRoot        The root node of the JSON request.
+ * @param   pErrInfo            Where to store the error information on failure, optional.
+ */
+static int rtFuzzCmdMasterProcessJsonReq(PRTFUZZCMDMASTER pThis, RTJSONVAL hJsonRoot, PRTERRINFO pErrInfo)
+{
+    RTJSONVAL hJsonValReq;
+    int rc = RTJsonValueQueryByName(hJsonRoot, "Request", &hJsonValReq);
+    if (RT_SUCCESS(rc))
+    {
+        const char *pszReq = RTJsonValueGetString(hJsonValReq);
+        if (pszReq)
+        {
+            if (!RTStrCmp(pszReq, "StartFuzzing"))
+                rc = rtFuzzCmdMasterProcessJsonReqStart(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "StopFuzzing"))
+                rc = rtFuzzCmdMasterProcessJsonReqStop(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "SuspendFuzzing"))
+                rc = rtFuzzCmdMasterProcessJsonReqSuspend(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "ResumeFuzzing"))
+                rc = rtFuzzCmdMasterProcessJsonReqResume(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "SaveFuzzingState"))
+                rc = rtFuzzCmdMasterProcessJsonReqSaveState(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "QueryStats"))
+                rc = rtFuzzCmdMasterProcessJsonReqQueryStats(pThis, hJsonRoot, pErrInfo);
+            else if (!RTStrCmp(pszReq, "Shutdown"))
+                pThis->fShutdown = true;
+            else
+                rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_JSON_VALUE_INVALID_TYPE, "JSON request malformed: \"Request\" contains unknown value \"%s\"", pszReq);
+        }
+        else
+            rc = rtFuzzCmdMasterErrorRc(pErrInfo, VERR_JSON_VALUE_INVALID_TYPE, "JSON request malformed: \"Request\" is not a string value");
+
+        RTJsonValueRelease(hJsonValReq);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(pErrInfo, rc, "JSON request malformed: Couldn't find \"Request\" value");
+
+    return rc;
+}
+
+
+/**
+ * Loads a fuzzing configuration for immediate startup from the given file.
+ *
+ * @returns IPRT status code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   pszFuzzCfg          The fuzzing config to load.
+ */
+static int rtFuzzCmdMasterFuzzCfgLoadFromFile(PRTFUZZCMDMASTER pThis, const char *pszFuzzCfg)
+{
+    RTJSONVAL hJsonRoot;
+    int rc = RTJsonParseFromFile(&hJsonRoot, pszFuzzCfg, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        rc = rtFuzzCmdMasterProcessJsonReqStart(pThis, hJsonRoot, NULL);
+        RTJsonValueRelease(hJsonRoot);
+    }
+    else
+        rc = rtFuzzCmdMasterErrorRc(NULL, rc, "JSON request malformed: Couldn't load file \"%s\"", pszFuzzCfg);
+
+    return rc;
+}
+
+
+/**
+ * Destroys all running fuzzers for the given master state.
+ *
+ * @returns nothing.
+ * @param   pThis               The fuzzing master command state.
+ */
+static void rtFuzzCmdMasterDestroy(PRTFUZZCMDMASTER pThis)
+{
+    RT_NOREF(pThis);
+}
+
+
+/**
+ * Sends an ACK response to the client.
+ *
+ * @returns nothing.
+ * @param   hSocket             The socket handle to send the ACK to.
+ * @param   pszResponse         Additional response data.
+ */
+static void rtFuzzCmdMasterTcpSendAck(RTSOCKET hSocket, const char *pszResponse)
+{
+    const char s_szSucc[] = "{ \"Status\": \"ACK\" }\n";
+    const char s_szSuccResp[] = "{ \"Status\": \"ACK\"\n  \"Response\":\n";
+    const char s_szSuccRespClose[] = "\n }\n";
+    if (pszResponse)
+    {
+        RTSGSEG aSegs[3];
+        RTSGBUF SgBuf;
+        aSegs[0].pvSeg = (void *)s_szSuccResp;
+        aSegs[0].cbSeg = sizeof(s_szSuccResp) - 1;
+        aSegs[1].pvSeg = (void *)pszResponse;
+        aSegs[1].cbSeg = strlen(pszResponse);
+        aSegs[2].pvSeg = (void *)s_szSuccRespClose;
+        aSegs[2].cbSeg = sizeof(s_szSuccRespClose) - 1;
+
+        RTSgBufInit(&SgBuf, &aSegs[0], RT_ELEMENTS(aSegs));
+        RTTcpSgWrite(hSocket, &SgBuf);
+    }
+    else
+        RTTcpWrite(hSocket, s_szSucc, sizeof(s_szSucc));
+}
+
+
+/**
+ * Sends an NACK response to the client.
+ *
+ * @returns nothing.
+ * @param   hSocket             The socket handle to send the ACK to.
+ * @param   pErrInfo            Optional error information to send along.
+ */
+static void rtFuzzCmdMasterTcpSendNAck(RTSOCKET hSocket, PRTERRINFO pErrInfo)
+{
+    const char s_szFail[] = "{ \"Status\": \"NACK\" }\n";
+    const char s_szFailInfo[] = "{ \"Status\": \"NACK\"\n \"Information\": \"%s\" }\n";
+
+    if (pErrInfo)
+    {
+        char szTmp[_1K];
+        ssize_t cchResp = RTStrPrintf2(szTmp, sizeof(szTmp), s_szFailInfo, pErrInfo->pszMsg);
+        if (cchResp > 0)
+            RTTcpWrite(hSocket, szTmp, cchResp);
+        else
+            RTTcpWrite(hSocket, s_szFail, strlen(s_szFail));
+    }
+    else
+        RTTcpWrite(hSocket, s_szFail, strlen(s_szFail));
+}
+
+
+/**
+ * TCP server serving callback for a single connection.
+ *
+ * @returns IPRT status code.
+ * @param   hSocket             The socket handle of the connection.
+ * @param   pvUser              Opaque user data.
+ */
+static DECLCALLBACK(int) rtFuzzCmdMasterTcpServe(RTSOCKET hSocket, void *pvUser)
+{
+    PRTFUZZCMDMASTER pThis = (PRTFUZZCMDMASTER)pvUser;
+    size_t cbReqMax = _32K;
+    size_t cbReq = 0;
+    uint8_t *pbReq = (uint8_t *)RTMemAllocZ(cbReqMax);
+
+    if (RT_LIKELY(pbReq))
+    {
+        uint8_t *pbCur = pbReq;
+
+        for (;;)
+        {
+            size_t cbThisRead = cbReqMax - cbReq;
+            int rc = RTTcpRead(hSocket, pbCur, cbThisRead, &cbThisRead);
+            if (RT_SUCCESS(rc))
+            {
+                cbReq += cbThisRead;
+
+                /* Check for a zero terminator marking the end of the request. */
+                uint8_t *pbEnd = (uint8_t *)memchr(pbCur, 0, cbThisRead);
+                if (pbEnd)
+                {
+                    /* Adjust request size, data coming after the zero terminiator is ignored right now. */
+                    cbReq -= cbThisRead - (pbEnd - pbCur) + 1;
+
+                    RTJSONVAL hJsonReq;
+                    RTERRINFOSTATIC ErrInfo;
+                    RTErrInfoInitStatic(&ErrInfo);
+
+                    rc = RTJsonParseFromBuf(&hJsonReq, pbReq, cbReq, &ErrInfo.Core);
+                    if (RT_SUCCESS(rc))
+                    {
+                        rc = rtFuzzCmdMasterProcessJsonReq(pThis, hJsonReq, &ErrInfo.Core);
+                        if (RT_SUCCESS(rc))
+                            rtFuzzCmdMasterTcpSendAck(hSocket, pThis->pszResponse);
+                        else
+                            rtFuzzCmdMasterTcpSendNAck(hSocket, &ErrInfo.Core);
+                        RTJsonValueRelease(hJsonReq);
+                    }
+                    else
+                        rtFuzzCmdMasterTcpSendNAck(hSocket, &ErrInfo.Core);
+
+                    if (pThis->pszResponse)
+                    {
+                        RTStrFree(pThis->pszResponse);
+                        pThis->pszResponse = NULL;
+                    }
+                    break;
+                }
+                else if (cbReq == cbReqMax)
+                {
+                    /* Try to increase the buffer. */
+                    uint8_t *pbReqNew = (uint8_t *)RTMemRealloc(pbReq, cbReqMax + _32K);
+                    if (RT_LIKELY(pbReqNew))
+                    {
+                        cbReqMax += _32K;
+                        pbReq = pbReqNew;
+                        pbCur = pbReq + cbReq;
+                    }
+                    else
+                        rtFuzzCmdMasterTcpSendNAck(hSocket, NULL);
+                }
+                else
+                    pbCur += cbThisRead;
+            }
+            else
+                break;
+        }
+    }
+    else
+        rtFuzzCmdMasterTcpSendNAck(hSocket, NULL);
+
+    if (pbReq)
+        RTMemFree(pbReq);
+
+    return pThis->fShutdown ? VERR_TCP_SERVER_STOP : VINF_SUCCESS;
+}
+
+
+/**
+ * Mainloop for the fuzzing master.
+ *
+ * @returns Process exit code.
+ * @param   pThis               The fuzzing master command state.
+ * @param   pszLoadCfg          Initial config to load.
+ */
+static RTEXITCODE rtFuzzCmdMasterRun(PRTFUZZCMDMASTER pThis, const char *pszLoadCfg)
+{
+    if (pszLoadCfg)
+    {
+        int rc = rtFuzzCmdMasterFuzzCfgLoadFromFile(pThis, pszLoadCfg);
+        if (RT_FAILURE(rc))
+            return RTEXITCODE_FAILURE;
+    }
+
+    /* Start up the control server. */
+    int rc = RTTcpServerCreateEx(NULL, pThis->uPort, &pThis->hTcpSrv);
+    if (RT_SUCCESS(rc))
+    {
+        do
+        {
+            rc = RTTcpServerListen(pThis->hTcpSrv, rtFuzzCmdMasterTcpServe, pThis);
+        } while (rc != VERR_TCP_SERVER_STOP);
+    }
+
+    RTTcpServerDestroy(pThis->hTcpSrv);
+    rtFuzzCmdMasterDestroy(pThis);
+    return RTEXITCODE_SUCCESS;
+}
+
+
+RTR3DECL(RTEXITCODE) RTFuzzCmdMaster(unsigned cArgs, char **papszArgs)
+{
+    /*
+     * Parse the command line.
+     */
+    static const RTGETOPTDEF s_aOptions[] =
+    {
+        { "--fuzz-config",                     'c', RTGETOPT_REQ_STRING  },
+        { "--temp-dir",                        't', RTGETOPT_REQ_STRING  },
+        { "--results-dir",                     'r', RTGETOPT_REQ_STRING  },
+        { "--listen-port",                     'p', RTGETOPT_REQ_UINT16  },
+        { "--daemonize",                       'd', RTGETOPT_REQ_NOTHING },
+        { "--daemonized",                      'Z', RTGETOPT_REQ_NOTHING },
+        { "--help",                            'h', RTGETOPT_REQ_NOTHING },
+        { "--version",                         'V', RTGETOPT_REQ_NOTHING },
+    };
+
+    RTEXITCODE rcExit = RTEXITCODE_SUCCESS;
+    RTGETOPTSTATE GetState;
+    int rc = RTGetOptInit(&GetState, cArgs, papszArgs, s_aOptions, RT_ELEMENTS(s_aOptions), 1,
+                          RTGETOPTINIT_FLAGS_OPTS_FIRST);
+    if (RT_SUCCESS(rc))
+    {
+        /* Option variables:  */
+        bool fDaemonize = false;
+        bool fDaemonized = false;
+        const char *pszLoadCfg = NULL;
+        RTFUZZCMDMASTER This;
+
+        RTListInit(&This.LstFuzzed);
+        This.hTcpSrv       = NIL_RTTCPSERVER;
+        This.uPort         = 4242;
+        This.pszTmpDir     = NULL;
+        This.pszResultsDir = NULL;
+        This.fShutdown     = false;
+        This.pszResponse   = NULL;
+
+        /* Argument parsing loop. */
+        bool fContinue = true;
+        do
+        {
+            RTGETOPTUNION ValueUnion;
+            int chOpt = RTGetOpt(&GetState, &ValueUnion);
+            switch (chOpt)
+            {
+                case 0:
+                    fContinue = false;
+                    break;
+
+                case 'c':
+                    pszLoadCfg = ValueUnion.psz;
+                    break;
+
+                case 'p':
+                    This.uPort = ValueUnion.u16;
+                    break;
+
+                case 't':
+                    This.pszTmpDir = ValueUnion.psz;
+                    break;
+
+                case 'r':
+                    This.pszResultsDir = ValueUnion.psz;
+                    break;
+
+                case 'd':
+                    fDaemonize = true;
+                    break;
+
+                case 'Z':
+                    fDaemonized = true;
+                    fDaemonize = false;
+                    break;
+
+                case 'h':
+                    RTPrintf("Usage: to be written\nOption dump:\n");
+                    for (unsigned i = 0; i < RT_ELEMENTS(s_aOptions); i++)
+                        RTPrintf(" -%c,%s\n", s_aOptions[i].iShort, s_aOptions[i].pszLong);
+                    fContinue = false;
+                    break;
+
+                case 'V':
+                    RTPrintf("%sr%d\n", RTBldCfgVersion(), RTBldCfgRevision());
+                    fContinue = false;
+                    break;
+
+                default:
+                    rcExit = RTGetOptPrintError(chOpt, &ValueUnion);
+                    fContinue = false;
+                    break;
+            }
+        } while (fContinue);
+
+        if (rcExit == RTEXITCODE_SUCCESS)
+        {
+            /*
+             * Daemonize ourselves if asked to.
+             */
+            if (fDaemonize)
+            {
+                rc = RTProcDaemonize(papszArgs, "--daemonized");
+                if (RT_FAILURE(rc))
+                    return RTMsgErrorExit(RTEXITCODE_FAILURE, "RTProcDaemonize: %Rrc\n", rc);
+            }
+            else
+                rcExit = rtFuzzCmdMasterRun(&This, pszLoadCfg);
+        }
+    }
+    else
+        rcExit = RTMsgErrorExit(RTEXITCODE_SYNTAX, "RTGetOptInit: %Rrc", rc);
+    return rcExit;
+}
+