Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg

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

1 files changed, 1175 insertions, 0 deletions

diff --git a/src/VBox/Main/src-server/UpdateAgentImpl.cpp b/src/VBox/Main/src-server/UpdateAgentImpl.cpp
new file mode 100644
index 00000000..3a89815a
--- /dev/null
+++ b/src/VBox/Main/src-server/UpdateAgentImpl.cpp
@@ -0,0 +1,1175 @@
+/* $Id: UpdateAgentImpl.cpp $ */
+/** @file
+ * IUpdateAgent COM class implementations.
+ */
+
+/*
+ * Copyright (C) 2020-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+
+#define LOG_GROUP LOG_GROUP_MAIN_UPDATEAGENT
+
+#include <iprt/cpp/utils.h>
+#include <iprt/param.h>
+#include <iprt/path.h>
+#include <iprt/http.h>
+#include <iprt/system.h>
+#include <iprt/message.h>
+#include <iprt/pipe.h>
+#include <iprt/env.h>
+#include <iprt/process.h>
+#include <iprt/assert.h>
+#include <iprt/err.h>
+#include <iprt/stream.h>
+#include <iprt/time.h>
+#include <VBox/com/defs.h>
+#include <VBox/err.h>
+#include <VBox/version.h>
+
+#include "HostImpl.h"
+#include "UpdateAgentImpl.h"
+#include "ProgressImpl.h"
+#include "AutoCaller.h"
+#include "LoggingNew.h"
+#include "VirtualBoxImpl.h"
+#include "VBoxEvents.h"
+#include "SystemPropertiesImpl.h"
+#include "ThreadTask.h"
+#include "VirtualBoxImpl.h"
+#include "VirtualBoxBase.h"
+
+
+/*********************************************************************************************************************************
+*   Update agent task implementation                                                                                             *
+*********************************************************************************************************************************/
+
+/**
+ * Base task class for asynchronous update agent tasks.
+ */
+class UpdateAgentTask : public ThreadTask
+{
+public:
+    UpdateAgentTask(UpdateAgentBase *aThat, Progress *aProgress)
+        : m_pParent(aThat)
+        , m_pProgress(aProgress)
+    {
+        m_strTaskName = "UpdateAgentTask";
+    }
+    virtual ~UpdateAgentTask(void) { }
+
+private:
+    void handler(void);
+
+    /** Weak pointer to parent (update agent). */
+    UpdateAgentBase     *m_pParent;
+    /** Smart pointer to the progress object for this job. */
+    ComObjPtr<Progress>  m_pProgress;
+
+    friend class UpdateAgent;  // allow member functions access to private data
+};
+
+void UpdateAgentTask::handler(void)
+{
+    UpdateAgentBase *pUpdateAgent = this->m_pParent;
+    AssertPtr(pUpdateAgent);
+
+    /** @todo Differentiate tasks once we have more stuff to do (downloading, installing, ++). */
+
+    HRESULT hrc = pUpdateAgent->i_checkForUpdateTask(this);
+
+    if (!m_pProgress.isNull())
+        m_pProgress->i_notifyComplete(hrc);
+
+    LogFlowFunc(("hrc=%Rhrc\n", hrc)); RT_NOREF(hrc);
+}
+
+
+/*********************************************************************************************************************************
+*   Update agent base class implementation                                                                                       *
+*********************************************************************************************************************************/
+
+/**
+ * Returns platform information as a string.
+ *
+ * @returns Platform information as string.
+ */
+/* static */
+Utf8Str UpdateAgentBase::i_getPlatformInfo(void)
+{
+    /* Prepare platform report: */
+    Utf8Str strPlatform;
+
+# if defined (RT_OS_WINDOWS)
+    strPlatform = "win";
+# elif defined (RT_OS_LINUX)
+    strPlatform = "linux";
+# elif defined (RT_OS_DARWIN)
+    strPlatform = "macosx";
+# elif defined (RT_OS_OS2)
+    strPlatform = "os2";
+# elif defined (RT_OS_FREEBSD)
+    strPlatform = "freebsd";
+# elif defined (RT_OS_SOLARIS)
+    strPlatform = "solaris";
+# else
+    strPlatform = "unknown";
+# endif
+
+    /* The format is <system>.<bitness>: */
+    strPlatform.appendPrintf(".%lu", ARCH_BITS);
+
+    /* Add more system information: */
+    int vrc;
+# ifdef RT_OS_LINUX
+    // WORKAROUND:
+    // On Linux we try to generate information using script first of all..
+
+    /* Get script path: */
+    char szAppPrivPath[RTPATH_MAX];
+    vrc = RTPathAppPrivateNoArch(szAppPrivPath, sizeof(szAppPrivPath));
+    AssertRC(vrc);
+    if (RT_SUCCESS(vrc))
+        vrc = RTPathAppend(szAppPrivPath, sizeof(szAppPrivPath), "/VBoxSysInfo.sh");
+    AssertRC(vrc);
+    if (RT_SUCCESS(vrc))
+    {
+        RTPIPE hPipeR;
+        RTHANDLE hStdOutPipe;
+        hStdOutPipe.enmType = RTHANDLETYPE_PIPE;
+        vrc = RTPipeCreate(&hPipeR, &hStdOutPipe.u.hPipe, RTPIPE_C_INHERIT_WRITE);
+        AssertLogRelRC(vrc);
+
+        char const *szAppPrivArgs[2];
+        szAppPrivArgs[0] = szAppPrivPath;
+        szAppPrivArgs[1] = NULL;
+        RTPROCESS hProc = NIL_RTPROCESS;
+
+        /* Run script: */
+        vrc = RTProcCreateEx(szAppPrivPath, szAppPrivArgs, RTENV_DEFAULT, 0 /*fFlags*/, NULL /*phStdin*/, &hStdOutPipe,
+                             NULL /*phStderr*/, NULL /*pszAsUser*/, NULL /*pszPassword*/, NULL /*pvExtraData*/, &hProc);
+
+        (void) RTPipeClose(hStdOutPipe.u.hPipe);
+        hStdOutPipe.u.hPipe = NIL_RTPIPE;
+
+        if (RT_SUCCESS(vrc))
+        {
+            RTPROCSTATUS  ProcStatus;
+            size_t        cbStdOutBuf  = 0;
+            size_t        offStdOutBuf = 0;
+            char          *pszStdOutBuf = NULL;
+            do
+            {
+                if (hPipeR != NIL_RTPIPE)
+                {
+                    char    achBuf[1024];
+                    size_t  cbRead;
+                    vrc = RTPipeReadBlocking(hPipeR, achBuf, sizeof(achBuf), &cbRead);
+                    if (RT_SUCCESS(vrc))
+                    {
+                        /* grow the buffer? */
+                        size_t cbBufReq = offStdOutBuf + cbRead + 1;
+                        if (   cbBufReq > cbStdOutBuf
+                            && cbBufReq < _256K)
+                        {
+                            size_t cbNew = RT_ALIGN_Z(cbBufReq, 16); // 1024
+                            void  *pvNew = RTMemRealloc(pszStdOutBuf, cbNew);
+                            if (pvNew)
+                            {
+                                pszStdOutBuf = (char *)pvNew;
+                                cbStdOutBuf  = cbNew;
+                            }
+                        }
+
+                        /* append if we've got room. */
+                        if (cbBufReq <= cbStdOutBuf)
+                        {
+                            (void) memcpy(&pszStdOutBuf[offStdOutBuf], achBuf, cbRead);
+                            offStdOutBuf = offStdOutBuf + cbRead;
+                            pszStdOutBuf[offStdOutBuf] = '\0';
+                        }
+                    }
+                    else
+                    {
+                        AssertLogRelMsg(vrc == VERR_BROKEN_PIPE, ("%Rrc\n", vrc));
+                        RTPipeClose(hPipeR);
+                        hPipeR = NIL_RTPIPE;
+                    }
+                }
+
+                /*
+                 * Service the process.  Block if we have no pipe.
+                 */
+                if (hProc != NIL_RTPROCESS)
+                {
+                    vrc = RTProcWait(hProc,
+                                     hPipeR == NIL_RTPIPE ? RTPROCWAIT_FLAGS_BLOCK : RTPROCWAIT_FLAGS_NOBLOCK,
+                                     &ProcStatus);
+                    if (RT_SUCCESS(vrc))
+                        hProc = NIL_RTPROCESS;
+                    else
+                        AssertLogRelMsgStmt(vrc == VERR_PROCESS_RUNNING, ("%Rrc\n", vrc), hProc = NIL_RTPROCESS);
+                }
+            } while (   hPipeR != NIL_RTPIPE
+                     || hProc != NIL_RTPROCESS);
+
+            if (   ProcStatus.enmReason == RTPROCEXITREASON_NORMAL
+                && ProcStatus.iStatus == 0) {
+                pszStdOutBuf[offStdOutBuf-1] = '\0';  // remove trailing newline
+                Utf8Str pszStdOutBufUTF8(pszStdOutBuf);
+                strPlatform.appendPrintf(" [%s]", pszStdOutBufUTF8.strip().c_str());
+                // For testing, here is some sample output:
+                //strPlatform.appendPrintf(" [Distribution: Redhat | Version: 7.6.1810 | Kernel: Linux version 3.10.0-952.27.2.el7.x86_64 (gcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC) ) #1 SMP Mon Jul 29 17:46:05 UTC 2019]");
+            }
+        }
+        else
+            vrc = VERR_TRY_AGAIN; /* (take the fallback path) */
+    }
+
+    if (RT_FAILURE(vrc))
+# endif /* RT_OS_LINUX */
+    {
+        /* Use RTSystemQueryOSInfo: */
+        char szTmp[256];
+
+        vrc = RTSystemQueryOSInfo(RTSYSOSINFO_PRODUCT, szTmp, sizeof(szTmp));
+        if ((RT_SUCCESS(vrc) || vrc == VERR_BUFFER_OVERFLOW) && szTmp[0] != '\0')
+            strPlatform.appendPrintf(" [Product: %s", szTmp);
+
+        vrc = RTSystemQueryOSInfo(RTSYSOSINFO_RELEASE, szTmp, sizeof(szTmp));
+        if ((RT_SUCCESS(vrc) || vrc == VERR_BUFFER_OVERFLOW) && szTmp[0] != '\0')
+            strPlatform.appendPrintf(" %sRelease: %s", strlen(szTmp) == 0 ? "[" : "| ", szTmp);
+
+        vrc = RTSystemQueryOSInfo(RTSYSOSINFO_VERSION, szTmp, sizeof(szTmp));
+        if ((RT_SUCCESS(vrc) || vrc == VERR_BUFFER_OVERFLOW) && szTmp[0] != '\0')
+            strPlatform.appendPrintf(" %sVersion: %s", strlen(szTmp) == 0 ? "[" : "| ", szTmp);
+
+        vrc = RTSystemQueryOSInfo(RTSYSOSINFO_SERVICE_PACK, szTmp, sizeof(szTmp));
+        if ((RT_SUCCESS(vrc) || vrc == VERR_BUFFER_OVERFLOW) && szTmp[0] != '\0')
+            strPlatform.appendPrintf(" %sSP: %s]", strlen(szTmp) == 0 ? "[" : "| ", szTmp);
+
+        if (!strPlatform.endsWith("]"))
+            strPlatform.append("]");
+    }
+
+    LogRel2(("UpdateAgent: Platform is '%s'\n", strPlatform.c_str()));
+
+    return strPlatform;
+}
+
+/**
+ * Returns the proxy mode as a string.
+ *
+ * @returns Proxy mode as string.
+ * @param   enmMode             Proxy mode to return as string.
+ */
+/* static */
+const char *UpdateAgentBase::i_proxyModeToStr(ProxyMode_T enmMode)
+{
+    switch (enmMode)
+    {
+        case ProxyMode_System:  return "System";
+        case ProxyMode_Manual:  return "Manual";
+        case ProxyMode_NoProxy: return "None";
+        default:                break;
+    }
+
+    AssertFailed();
+    return "<Invalid>";
+}
+
+/**
+ * Returns whether a given URL's scheme is supported or not.
+ *
+ * @returns \c true if scheme is supported, or \c false if not.
+ * @param   strUrl              URL to check scheme for.
+ *
+ * @note Empty URL are considered as being supported for convenience.
+ */
+bool UpdateAgentBase::i_urlSchemeIsSupported(const Utf8Str &strUrl) const
+{
+    if (strUrl.isEmpty())
+        return true;
+    return strUrl.startsWith("https://", com::Utf8Str::CaseInsensitive);
+}
+
+
+/*********************************************************************************************************************************
+*   Update agent class implementation                                                                                            *
+*********************************************************************************************************************************/
+UpdateAgent::UpdateAgent()
+{
+}
+
+UpdateAgent::~UpdateAgent()
+{
+}
+
+HRESULT UpdateAgent::FinalConstruct(void)
+{
+    return BaseFinalConstruct();
+}
+
+void UpdateAgent::FinalRelease(void)
+{
+    uninit();
+
+    BaseFinalRelease();
+}
+
+HRESULT UpdateAgent::init(VirtualBox *aVirtualBox)
+{
+    /* Weak reference to a VirtualBox object */
+    unconst(m_VirtualBox) = aVirtualBox;
+
+    HRESULT hrc = unconst(m_EventSource).createObject();
+    if (SUCCEEDED(hrc))
+        hrc = m_EventSource->init();
+
+    return hrc;
+}
+
+void UpdateAgent::uninit(void)
+{
+    // Enclose the state transition Ready->InUninit->NotReady.
+    AutoUninitSpan autoUninitSpan(this);
+    if (autoUninitSpan.uninitDone())
+        return;
+
+    unconst(m_EventSource).setNull();
+}
+
+HRESULT UpdateAgent::checkFor(ComPtr<IProgress> &aProgress)
+{
+    RT_NOREF(aProgress);
+
+    return VBOX_E_NOT_SUPPORTED;
+}
+
+HRESULT UpdateAgent::download(ComPtr<IProgress> &aProgress)
+{
+    RT_NOREF(aProgress);
+
+    return VBOX_E_NOT_SUPPORTED;
+}
+
+HRESULT UpdateAgent::install(ComPtr<IProgress> &aProgress)
+{
+    RT_NOREF(aProgress);
+
+    return VBOX_E_NOT_SUPPORTED;
+}
+
+HRESULT UpdateAgent::rollback(void)
+{
+    return VBOX_E_NOT_SUPPORTED;
+}
+
+HRESULT UpdateAgent::getName(com::Utf8Str &aName)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aName = mData.m_strName;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getEventSource(ComPtr<IEventSource> &aEventSource)
+{
+    LogFlowThisFuncEnter();
+
+    /* No need to lock - lifetime constant. */
+    m_EventSource.queryInterfaceTo(aEventSource.asOutParam());
+
+    LogFlowFuncLeaveRC(S_OK);
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getOrder(ULONG *aOrder)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aOrder = 0; /* 0 means no order / disabled. */
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getDependsOn(std::vector<com::Utf8Str> &aDeps)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aDeps.resize(0); /* No dependencies by default. */
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getVersion(com::Utf8Str &aVer)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aVer = mData.m_lastResult.strVer;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getDownloadUrl(com::Utf8Str &aUrl)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aUrl = mData.m_lastResult.strDownloadUrl;
+
+    return S_OK;
+}
+
+
+HRESULT UpdateAgent::getWebUrl(com::Utf8Str &aUrl)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aUrl = mData.m_lastResult.strWebUrl;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getReleaseNotes(com::Utf8Str &aRelNotes)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aRelNotes = mData.m_lastResult.strReleaseNotes;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getEnabled(BOOL *aEnabled)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aEnabled = m->fEnabled;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::setEnabled(const BOOL aEnabled)
+{
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->fEnabled = aEnabled;
+
+    return i_commitSettings(alock);
+}
+
+
+HRESULT UpdateAgent::getHidden(BOOL *aHidden)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aHidden = mData.m_fHidden;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getState(UpdateState_T *aState)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aState = mData.m_enmState;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getCheckFrequency(ULONG *aFreqSeconds)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aFreqSeconds = m->uCheckFreqSeconds;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::setCheckFrequency(ULONG aFreqSeconds)
+{
+    if (aFreqSeconds < RT_SEC_1DAY) /* Don't allow more frequent checks for now. */
+        return setError(E_INVALIDARG, tr("Frequency too small; one day is the minimum"));
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->uCheckFreqSeconds = aFreqSeconds;
+
+    return i_commitSettings(alock);
+}
+
+HRESULT UpdateAgent::getChannel(UpdateChannel_T *aChannel)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aChannel = m->enmChannel;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::setChannel(UpdateChannel_T aChannel)
+{
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->enmChannel = aChannel;
+
+    return i_commitSettings(alock);
+}
+
+HRESULT UpdateAgent::getCheckCount(ULONG *aCount)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    *aCount = m->uCheckCount;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getRepositoryURL(com::Utf8Str &aRepo)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aRepo = m->strRepoUrl;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::setRepositoryURL(const com::Utf8Str &aRepo)
+{
+    if (!i_urlSchemeIsSupported(aRepo))
+        return setError(E_INVALIDARG, tr("Invalid URL scheme specified!"));
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->strRepoUrl = aRepo;
+
+    return i_commitSettings(alock);
+}
+
+HRESULT UpdateAgent::getLastCheckDate(com::Utf8Str &aDate)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    aDate = m->strLastCheckDate;
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getIsCheckNeeded(BOOL *aCheckNeeded)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    /*
+     * Is update checking enabled at all?
+     */
+    if (!m->fEnabled)
+    {
+        *aCheckNeeded = FALSE;
+        return S_OK;
+    }
+
+    /*
+     * When was the last update?
+     */
+    if (m->strLastCheckDate.isEmpty()) /* No prior update check performed -- do so now. */
+    {
+        *aCheckNeeded = TRUE;
+        return S_OK;
+    }
+
+    RTTIMESPEC LastCheckTime;
+    if (!RTTimeSpecFromString(&LastCheckTime, Utf8Str(m->strLastCheckDate).c_str()))
+    {
+        *aCheckNeeded = TRUE; /* Invalid date set or error? Perform check. */
+        return S_OK;
+    }
+
+    /*
+     * Compare last update with how often we are supposed to check for updates.
+     */
+    if (   !m->uCheckFreqSeconds                /* Paranoia */
+        ||  m->uCheckFreqSeconds < RT_SEC_1DAY) /* This is the minimum we currently allow. */
+    {
+        /* Consider config (enable, 0 day interval) as checking once but never again.
+           We've already check since we've got a date. */
+        *aCheckNeeded = FALSE;
+        return S_OK;
+    }
+
+    uint64_t const cCheckFreqDays = m->uCheckFreqSeconds / RT_SEC_1DAY_64;
+
+    RTTIMESPEC TimeDiff;
+    RTTimeSpecSub(RTTimeNow(&TimeDiff), &LastCheckTime);
+
+    int64_t const diffLastCheckSecs = RTTimeSpecGetSeconds(&TimeDiff);
+    int64_t const diffLastCheckDays = diffLastCheckSecs / (int64_t)RT_SEC_1DAY_64;
+
+    /* Be as accurate as possible. */
+    *aCheckNeeded = diffLastCheckSecs >= (int64_t)m->uCheckFreqSeconds ? TRUE : FALSE;
+
+    LogRel2(("Update agent (%s): Last update %RI64 days (%RI64 seconds) ago, check frequency is every %RU64 days (%RU64 seconds) -> Check %s\n",
+             mData.m_strName.c_str(), diffLastCheckDays, diffLastCheckSecs, cCheckFreqDays, m->uCheckFreqSeconds,
+             *aCheckNeeded ? "needed" : "not needed"));
+
+    return S_OK;
+}
+
+HRESULT UpdateAgent::getSupportedChannels(std::vector<UpdateChannel_T> &aSupportedChannels)
+{
+    /* No need to take the read lock, as m_enmChannels is const. */
+
+    aSupportedChannels = mData.m_enmChannels;
+
+    return S_OK;
+}
+
+
+/*********************************************************************************************************************************
+*   Internal helper methods of update agent class                                                                                *
+*********************************************************************************************************************************/
+
+/**
+ * Loads the settings of the update agent base class.
+ *
+ * @returns HRESULT
+ * @retval  E_INVALIDARG if to-load settings are invalid / not supported.
+ * @param   data                Where to load the settings from.
+ */
+HRESULT UpdateAgent::i_loadSettings(const settings::UpdateAgent &data)
+{
+    AutoCaller autoCaller(this);
+    if (FAILED(autoCaller.hrc())) return autoCaller.hrc();
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->fEnabled          = data.fEnabled;
+    m->enmChannel        = data.enmChannel;
+    m->uCheckFreqSeconds = data.uCheckFreqSeconds;
+    if (data.strRepoUrl.isNotEmpty()) /* Prevent overwriting the agent's default URL when XML settings are empty. */
+        m->strRepoUrl    = data.strRepoUrl;
+    m->strLastCheckDate  = data.strLastCheckDate;
+    m->uCheckCount       = data.uCheckCount;
+
+    /* Sanity checks. */
+    if (!i_urlSchemeIsSupported(data.strRepoUrl))
+        return setError(E_INVALIDARG, tr("Invalid URL scheme specified!"));
+
+    return S_OK;
+}
+
+/**
+ * Saves the settings of the update agent base class.
+ *
+ * @returns HRESULT
+ * @param   data                Where to save the settings to.
+ */
+HRESULT UpdateAgent::i_saveSettings(settings::UpdateAgent &data)
+{
+    AutoCaller autoCaller(this);
+    if (FAILED(autoCaller.hrc())) return autoCaller.hrc();
+
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    data = *m;
+
+    return S_OK;
+}
+
+/**
+ * Sets the update check count.
+ *
+ * @returns HRESULT
+ * @param   aCount              Update check count to set.
+ */
+HRESULT UpdateAgent::i_setCheckCount(ULONG aCount)
+{
+    AutoCaller autoCaller(this);
+    if (FAILED(autoCaller.hrc())) return autoCaller.hrc();
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->uCheckCount = aCount;
+
+    return i_commitSettings(alock);
+}
+
+/**
+ * Sets the last update check date.
+ *
+ * @returns HRESULT
+ * @param   aDate               Last update check date to set.
+ *                              Must be in ISO 8601 format (e.g. 2020-05-11T21:13:39.348416000Z).
+ */
+HRESULT UpdateAgent::i_setLastCheckDate(const com::Utf8Str &aDate)
+{
+    AutoCaller autoCaller(this);
+    if (FAILED(autoCaller.hrc())) return autoCaller.hrc();
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->strLastCheckDate = aDate;
+
+    return i_commitSettings(alock);
+}
+
+/**
+ * Internal helper function to commit modified settings.
+ *
+ * @returns HRESULT
+ * @param   aLock               Write lock to release before committing settings.
+ */
+HRESULT UpdateAgent::i_commitSettings(AutoWriteLock &aLock)
+{
+    aLock.release();
+
+    m_VirtualBox->i_onUpdateAgentSettingsChanged(this, "" /** @todo Include attribute hints */);
+
+    AutoWriteLock vboxLock(m_VirtualBox COMMA_LOCKVAL_SRC_POS);
+    return m_VirtualBox->i_saveSettings();
+}
+
+/**
+ * Returns the proxy mode to use.
+ *
+ * @returns HRESULT
+ * @param   aMode               Where to return the proxy mode.
+ */
+HRESULT UpdateAgent::i_getProxyMode(ProxyMode_T *aMode)
+{
+    ComPtr<ISystemProperties> pSystemProperties;
+    HRESULT hrc = m_VirtualBox->COMGETTER(SystemProperties)(pSystemProperties.asOutParam());
+    if (SUCCEEDED(hrc))
+        hrc = pSystemProperties->COMGETTER(ProxyMode)(aMode);
+
+    return hrc;
+}
+
+/**
+ * Returns the proxy URL to use.
+ *
+ * @returns HRESULT
+ * @param   aUrl                Where to return the proxy URL to use.
+ */
+HRESULT UpdateAgent::i_getProxyURL(com::Utf8Str &aUrl)
+{
+    ComPtr<ISystemProperties> pSystemProperties;
+    HRESULT hrc = m_VirtualBox->COMGETTER(SystemProperties)(pSystemProperties.asOutParam());
+    if (SUCCEEDED(hrc))
+    {
+        com::Bstr bstrVal;
+        hrc = pSystemProperties->COMGETTER(ProxyURL)(bstrVal.asOutParam());
+        if (SUCCEEDED(hrc))
+            aUrl = bstrVal;
+    }
+
+    return hrc;
+}
+
+/**
+ * Configures a HTTP client's proxy.
+ *
+ * @returns HRESULT
+ * @param   hHttp               HTTP client to configure proxy for.
+ */
+HRESULT UpdateAgent::i_configureProxy(RTHTTP hHttp)
+{
+    ProxyMode_T enmProxyMode;
+    HRESULT hrc = i_getProxyMode(&enmProxyMode);
+    ComAssertComRCRetRC(hrc);
+
+    Utf8Str strProxyUrl;
+    hrc = i_getProxyURL(strProxyUrl);
+    ComAssertComRCRetRC(hrc);
+
+    if (enmProxyMode == ProxyMode_Manual)
+    {
+        int vrc = RTHttpSetProxyByUrl(hHttp, strProxyUrl.c_str());
+        if (RT_FAILURE(vrc))
+            return i_reportError(vrc, tr("RTHttpSetProxyByUrl() failed: %Rrc"), vrc);
+    }
+    else if (enmProxyMode == ProxyMode_System)
+    {
+        int vrc = RTHttpUseSystemProxySettings(hHttp);
+        if (RT_FAILURE(vrc))
+            return i_reportError(vrc, tr("RTHttpUseSystemProxySettings() failed: %Rrc"), vrc);
+    }
+    else
+        Assert(enmProxyMode == ProxyMode_NoProxy);
+
+    LogRel2(("Update agent (%s): Using proxy mode = '%s', URL = '%s'\n",
+             mData.m_strName.c_str(), UpdateAgentBase::i_proxyModeToStr(enmProxyMode), strProxyUrl.c_str()));
+
+    return S_OK;
+}
+
+/**
+ * Reports an error by setting the error info and also informs subscribed listeners.
+ *
+ * @returns HRESULT
+ * @param   vrc                 Result code (IPRT-style) to report.
+ * @param   pcszMsgFmt          Error message to report.
+ * @param   ...                 Format string for \a pcszMsgFmt.
+ */
+HRESULT UpdateAgent::i_reportError(int vrc, const char *pcszMsgFmt, ...)
+{
+    AssertReturn(pcszMsgFmt && *pcszMsgFmt != '\0', E_INVALIDARG);
+
+    va_list va;
+    va_start(va, pcszMsgFmt);
+
+    Utf8Str strMsg;
+    int const vrc2 = strMsg.printfVNoThrow(pcszMsgFmt, va);
+    if (RT_FAILURE(vrc2))
+    {
+        va_end(va);
+        return setErrorBoth(VBOX_E_IPRT_ERROR, vrc2, tr("Failed to format update agent error string (%Rrc)"), vrc2);
+    }
+
+    va_end(va);
+
+    LogRel(("Update agent (%s): %s\n", mData.m_strName.c_str(), strMsg.c_str()));
+
+    m_VirtualBox->i_onUpdateAgentError(this, strMsg.c_str(), vrc);
+
+    return setErrorBoth(VBOX_E_IPRT_ERROR, vrc, strMsg.c_str());
+}
+
+
+/*********************************************************************************************************************************
+*   Host update implementation                                                                                                   *
+*********************************************************************************************************************************/
+
+HostUpdateAgent::HostUpdateAgent(void)
+{
+}
+
+HostUpdateAgent::~HostUpdateAgent(void)
+{
+}
+
+
+HRESULT HostUpdateAgent::FinalConstruct(void)
+{
+    return BaseFinalConstruct();
+}
+
+void HostUpdateAgent::FinalRelease(void)
+{
+    uninit();
+
+    BaseFinalRelease();
+}
+
+HRESULT HostUpdateAgent::init(VirtualBox *aVirtualBox)
+{
+    // Enclose the state transition NotReady->InInit->Ready.
+    AutoInitSpan autoInitSpan(this);
+    AssertReturn(autoInitSpan.isOk(), E_FAIL);
+
+    /* Initialize the bare minimum to get things going.
+     ** @todo Add more stuff later here. */
+    mData.m_strName = "VirtualBox";
+    mData.m_fHidden = false;
+
+    const UpdateChannel_T aChannels[] =
+    {
+        UpdateChannel_Stable,
+        UpdateChannel_All,
+        UpdateChannel_WithBetas
+        /** @todo Add UpdateChannel_WithTesting once it's implemented on the backend. */
+    };
+    unconst(mData.m_enmChannels).assign(aChannels, aChannels + RT_ELEMENTS(aChannels));
+
+    /* Set default repository. */
+    m->strRepoUrl = "https://update.virtualbox.org";
+
+    HRESULT hrc = UpdateAgent::init(aVirtualBox);
+    if (SUCCEEDED(hrc))
+        autoInitSpan.setSucceeded();
+
+    return hrc;
+}
+
+void HostUpdateAgent::uninit(void)
+{
+    // Enclose the state transition Ready->InUninit->NotReady.
+    AutoUninitSpan autoUninitSpan(this);
+    if (autoUninitSpan.uninitDone())
+        return;
+}
+
+HRESULT HostUpdateAgent::checkFor(ComPtr<IProgress> &aProgress)
+{
+    AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    ComObjPtr<Progress> pProgress;
+    HRESULT hrc = pProgress.createObject();
+    if (FAILED(hrc))
+        return hrc;
+
+    hrc = pProgress->init(m_VirtualBox,
+                          static_cast<IUpdateAgent*>(this),
+                          tr("Checking for update for %s ...", this->mData.m_strName.c_str()),
+                          TRUE /* aCancelable */);
+    if (FAILED(hrc))
+        return hrc;
+
+    /* initialize the worker task */
+    UpdateAgentTask *pTask = new UpdateAgentTask(this, pProgress);
+    hrc = pTask->createThread();
+    pTask = NULL;
+    if (FAILED(hrc))
+        return hrc;
+
+    return pProgress.queryInterfaceTo(aProgress.asOutParam());
+}
+
+
+/*********************************************************************************************************************************
+*   Host update internal functions                                                                                               *
+*********************************************************************************************************************************/
+
+/**
+ * Task callback to perform an update check for the VirtualBox host (core).
+ *
+ * @returns HRESULT
+ * @param   pTask               Associated update agent task to use.
+ */
+DECLCALLBACK(HRESULT) HostUpdateAgent::i_checkForUpdateTask(UpdateAgentTask *pTask)
+{
+    RT_NOREF(pTask);
+
+    AssertReturn(m->strRepoUrl.isNotEmpty(), E_INVALIDARG);
+
+    // Following the sequence of steps in UIUpdateStepVirtualBox::sltStartStep()
+    // Build up our query URL starting with the configured repository.
+    Utf8Str strUrl;
+    strUrl.appendPrintf("%s/query.php/?", m->strRepoUrl.c_str());
+
+    // Add platform ID.
+    Bstr platform;
+    HRESULT hrc = m_VirtualBox->COMGETTER(PackageType)(platform.asOutParam());
+    AssertComRCReturn(hrc, hrc);
+    strUrl.appendPrintf("platform=%ls", platform.raw()); // e.g. SOLARIS_64BITS_GENERIC
+
+    // Get the complete current version string for the query URL
+    Bstr versionNormalized;
+    hrc = m_VirtualBox->COMGETTER(VersionNormalized)(versionNormalized.asOutParam());
+    AssertComRCReturn(hrc, hrc);
+    strUrl.appendPrintf("&version=%ls", versionNormalized.raw()); // e.g. 6.1.1
+#ifdef DEBUG // Comment out previous line and uncomment this one for testing.
+//  strUrl.appendPrintf("&version=6.0.12");
+#endif
+
+    ULONG revision = 0;
+    hrc = m_VirtualBox->COMGETTER(Revision)(&revision);
+    AssertComRCReturn(hrc, hrc);
+    strUrl.appendPrintf("_%u", revision); // e.g. 135618
+
+    // Update the last update check timestamp.
+    RTTIME Time;
+    RTTIMESPEC TimeNow;
+    char szTimeStr[RTTIME_STR_LEN];
+    RTTimeToString(RTTimeExplode(&Time, RTTimeNow(&TimeNow)), szTimeStr, sizeof(szTimeStr));
+    LogRel2(("Update agent (%s): Setting last update check timestamp to '%s'\n", mData.m_strName.c_str(), szTimeStr));
+
+    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+    m->strLastCheckDate = szTimeStr;
+    m->uCheckCount++;
+
+    hrc = i_commitSettings(alock);
+    AssertComRCReturn(hrc, hrc);
+
+    strUrl.appendPrintf("&count=%RU32", m->uCheckCount);
+
+    // Update the query URL (if necessary) with the 'channel' information.
+    switch (m->enmChannel)
+    {
+        case UpdateChannel_All:
+            strUrl.appendPrintf("&branch=allrelease"); // query.php expects 'allrelease' and not 'allreleases'
+            break;
+        case UpdateChannel_WithBetas:
+            strUrl.appendPrintf("&branch=withbetas");
+            break;
+        /** @todo Handle UpdateChannel_WithTesting once implemented on the backend. */
+        case UpdateChannel_Stable:
+            RT_FALL_THROUGH();
+        default:
+            strUrl.appendPrintf("&branch=stable");
+            break;
+    }
+
+    LogRel2(("Update agent (%s): Using URL '%s'\n", mData.m_strName.c_str(), strUrl.c_str()));
+
+    /*
+     * Compose the User-Agent header for the GET request.
+     */
+    Bstr version;
+    hrc = m_VirtualBox->COMGETTER(Version)(version.asOutParam()); // e.g. 6.1.0_RC1
+    AssertComRCReturn(hrc, hrc);
+
+    Utf8StrFmt const strUserAgent("VirtualBox %ls <%s>", version.raw(), UpdateAgent::i_getPlatformInfo().c_str());
+    LogRel2(("Update agent (%s): Using user agent '%s'\n",  mData.m_strName.c_str(), strUserAgent.c_str()));
+
+    /*
+     * Create the HTTP client instance and pass it to a inner worker method to
+     * ensure proper cleanup.
+     */
+    RTHTTP hHttp = NIL_RTHTTP;
+    int vrc = RTHttpCreate(&hHttp);
+    if (RT_SUCCESS(vrc))
+    {
+        try
+        {
+            hrc = i_checkForUpdateInner(hHttp, strUrl, strUserAgent);
+        }
+        catch (...)
+        {
+            AssertFailed();
+            hrc = E_UNEXPECTED;
+        }
+        RTHttpDestroy(hHttp);
+    }
+    else
+        hrc = i_reportError(vrc, tr("RTHttpCreate() failed: %Rrc"), vrc);
+
+    return hrc;
+}
+
+/**
+ * Inner function of the actual update checking mechanism.
+ *
+ * @returns HRESULT
+ * @param   hHttp               HTTP client instance to use for checking.
+ * @param   strUrl              URL of repository to check.
+ * @param   strUserAgent        HTTP user agent to use for checking.
+ */
+HRESULT HostUpdateAgent::i_checkForUpdateInner(RTHTTP hHttp, Utf8Str const &strUrl, Utf8Str const &strUserAgent)
+{
+    /*
+     * Configure the proxy (if any).
+     */
+    HRESULT hrc = i_configureProxy(hHttp);
+    if (FAILED(hrc))
+        return hrc;
+
+    /** @todo Are there any other headers needed to be added first via RTHttpSetHeaders()? */
+    int vrc = RTHttpAddHeader(hHttp, "User-Agent", strUserAgent.c_str(), strUserAgent.length(), RTHTTPADDHDR_F_BACK);
+    if (RT_FAILURE(vrc))
+        return i_reportError(vrc, tr("RTHttpAddHeader() failed: %Rrc (user agent)"), vrc);
+
+    /*
+     * Perform the GET request, returning raw binary stuff.
+     */
+    void *pvResponse = NULL;
+    size_t cbResponse = 0;
+    vrc = RTHttpGetBinary(hHttp, strUrl.c_str(), &pvResponse, &cbResponse);
+    if (RT_FAILURE(vrc))
+        return i_reportError(vrc, tr("RTHttpGetBinary() failed: %Rrc"), vrc);
+
+    /* Note! We can do nothing that might throw exceptions till we call RTHttpFreeResponse! */
+
+    /*
+     * If url is platform=DARWIN_64BITS_GENERIC&version=6.0.12&branch=stable for example, the reply is:
+     *      6.0.14<SPACE>https://download.virtualbox.org/virtualbox/6.0.14/VirtualBox-6.0.14-133895-OSX.dmg
+     * If no update required, 'UPTODATE' is returned.
+     */
+    /* Parse out the two first words of the response, ignoring whatever follows: */
+    const char *pchResponse = (const char *)pvResponse;
+    while (cbResponse > 0 && *pchResponse == ' ')
+        cbResponse--, pchResponse++;
+
+    char ch;
+    const char *pchWord0 = pchResponse;
+    while (cbResponse > 0 && (ch = *pchResponse) != ' ' && ch != '\0')
+        cbResponse--, pchResponse++;
+    size_t const cchWord0 = (size_t)(pchResponse - pchWord0);
+
+    while (cbResponse > 0 && *pchResponse == ' ')
+        cbResponse--, pchResponse++;
+    const char *pchWord1 = pchResponse;
+    while (cbResponse > 0 && (ch = *pchResponse) != ' ' && ch != '\0')
+        cbResponse--, pchResponse++;
+    size_t const cchWord1 = (size_t)(pchResponse - pchWord1);
+
+    /* Decode the two word: */
+    static char const s_szUpToDate[] = "UPTODATE";
+    if (   cchWord0 == sizeof(s_szUpToDate) - 1
+        && memcmp(pchWord0, s_szUpToDate, sizeof(s_szUpToDate) - 1) == 0)
+    {
+        AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+        mData.m_enmState = UpdateState_NotAvailable;
+        hrc = S_OK;
+
+        alock.release(); /* Release lock before firing off event. */
+
+        m_VirtualBox->i_onUpdateAgentStateChanged(this, UpdateState_NotAvailable);
+    }
+    else
+    {
+        mData.m_enmState = UpdateState_Error; /* Play safe by default. */
+
+        vrc = RTStrValidateEncodingEx(pchWord0, cchWord0, 0 /*fFlags*/);
+        if (RT_SUCCESS(vrc))
+            vrc = RTStrValidateEncodingEx(pchWord1, cchWord1, 0 /*fFlags*/);
+        if (RT_SUCCESS(vrc))
+        {
+            /** @todo Any additional sanity checks we could perform here? */
+            hrc = mData.m_lastResult.strVer.assignEx(pchWord0, cchWord0);
+            if (SUCCEEDED(hrc))
+                hrc = mData.m_lastResult.strDownloadUrl.assignEx(pchWord1, cchWord1);
+
+            if (SUCCEEDED(hrc))
+            {
+                AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+
+                /** @todo Implement this on the backend first.
+                 *        We also could do some guessing based on the installed version vs. reported update version? */
+                mData.m_lastResult.enmSeverity = UpdateSeverity_Invalid;
+                mData.m_enmState               = UpdateState_Available;
+
+                alock.release(); /* Release lock before firing off events. */
+
+                m_VirtualBox->i_onUpdateAgentStateChanged(this, UpdateState_Available);
+                m_VirtualBox->i_onUpdateAgentAvailable(this, mData.m_lastResult.strVer, m->enmChannel,
+                                                       mData.m_lastResult.enmSeverity, mData.m_lastResult.strDownloadUrl,
+                                                       mData.m_lastResult.strWebUrl, mData.m_lastResult.strReleaseNotes);
+            }
+            else
+                hrc = i_reportError(VERR_GENERAL_FAILURE /** @todo Use a better hrc */,
+                                    tr("Invalid server response [1]: %Rhrc (%.*Rhxs -- %.*Rhxs)"),
+                                    hrc, cchWord0, pchWord0, cchWord1, pchWord1);
+
+            LogRel2(("Update agent (%s): HTTP server replied: %.*s %.*s\n",
+                     mData.m_strName.c_str(), cchWord0, pchWord0, cchWord1, pchWord1));
+        }
+        else
+            hrc = i_reportError(vrc, tr("Invalid server response [2]: %Rrc (%.*Rhxs -- %.*Rhxs)"),
+                                vrc, cchWord0, pchWord0, cchWord1, pchWord1);
+    }
+
+    RTHttpFreeResponse(pvResponse);
+
+    return hrc;
+}
+