1 files changed, 440 insertions, 0 deletions
diff --git a/src/VBox/Main/src-server/HostDnsService.cpp b/src/VBox/Main/src-server/HostDnsService.cpp
new file mode 100644
index 00000000..bd91ca41
--- /dev/null
+++ b/src/VBox/Main/src-server/HostDnsService.cpp
@@ -0,0 +1,440 @@
+/* $Id: HostDnsService.cpp $ */
+/** @file
+ * Base class for Host DNS & Co services.
+ */
+
+/*
+ * Copyright (C) 2013-2022 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_HOST
+#include <VBox/com/array.h>
+#include <VBox/com/ptr.h>
+#include <VBox/com/string.h>
+
+#include <iprt/cpp/utils.h>
+
+#include "LoggingNew.h"
+#include "VirtualBoxImpl.h"
+#include <iprt/time.h>
+#include <iprt/thread.h>
+#include <iprt/semaphore.h>
+#include <iprt/critsect.h>
+
+#include <algorithm>
+#include <set>
+#include <iprt/sanitized/string>
+#include "HostDnsService.h"
+
+
+
+static void dumpHostDnsStrVector(const std::string &prefix, const std::vector<std::string> &v)
+{
+    int i = 1;
+    for (std::vector<std::string>::const_iterator it = v.begin();
+         it != v.end();
+         ++it, ++i)
+        LogRel(("  %s %d: %s\n", prefix.c_str(), i, it->c_str()));
+    if (v.empty())
+        LogRel(("  no %s entries\n", prefix.c_str()));
+}
+
+static void dumpHostDnsInformation(const HostDnsInformation &info)
+{
+    dumpHostDnsStrVector("server", info.servers);
+
+    if (!info.domain.empty())
+        LogRel(("  domain: %s\n", info.domain.c_str()));
+    else
+        LogRel(("  no domain set\n"));
+
+    dumpHostDnsStrVector("search string", info.searchList);
+}
+
+bool HostDnsInformation::equals(const HostDnsInformation &info, uint32_t fLaxComparison) const
+{
+    bool fSameServers;
+    if ((fLaxComparison & IGNORE_SERVER_ORDER) == 0)
+        fSameServers = (servers == info.servers);
+    else
+    {
+        std::set<std::string> l(servers.begin(), servers.end());
+        std::set<std::string> r(info.servers.begin(), info.servers.end());
+
+        fSameServers = (l == r);
+    }
+
+    bool fSameDomain, fSameSearchList;
+    if ((fLaxComparison & IGNORE_SUFFIXES) == 0)
+    {
+        fSameDomain = (domain == info.domain);
+        fSameSearchList = (searchList == info.searchList);
+    }
+    else
+        fSameDomain = fSameSearchList = true;
+
+    return fSameServers && fSameDomain && fSameSearchList;
+}
+
+DECLINLINE(void) detachVectorOfString(const std::vector<std::string>& v, std::vector<com::Utf8Str> &aArray)
+{
+    aArray.resize(v.size());
+    size_t i = 0;
+    for (std::vector<std::string>::const_iterator it = v.begin(); it != v.end(); ++it, ++i)
+        aArray[i] = Utf8Str(it->c_str()); /** @todo r=bird: *it isn't necessarily UTF-8 clean!!
+                                           * On darwin we do silly shit like using CFStringGetSystemEncoding()
+                                           * that may be UTF-8 but doesn't need to be.
+                                           *
+                                           * Why on earth are we using std::string here anyway?
+                                           */
+}
+
+struct HostDnsServiceBase::Data
+{
+    Data(bool aThreaded)
+        : pProxy(NULL)
+        , fThreaded(aThreaded)
+        , hMonitorThreadEvent(NIL_RTSEMEVENT)
+        , hMonitorThread(NIL_RTTHREAD)
+    {}
+
+    /** Weak pointer to parent proxy object. */
+    HostDnsMonitorProxy *pProxy;
+    /** Whether the DNS monitor implementation has a dedicated monitoring thread. Optional. */
+    const bool           fThreaded;
+    /** Event for the monitor thread, if any. */
+    RTSEMEVENT           hMonitorThreadEvent;
+    /** Handle of the monitor thread, if any. */
+    RTTHREAD             hMonitorThread;
+    /** Generic host DNS information. */
+    HostDnsInformation   info;
+};
+
+struct HostDnsMonitorProxy::Data
+{
+    Data(HostDnsServiceBase *aMonitor, VirtualBox *aParent)
+        : pVirtualBox(aParent)
+        , pMonitorImpl(aMonitor)
+        , uLastExtraDataPoll(0)
+        , fLaxComparison(0)
+        , info()
+    {}
+
+    VirtualBox *pVirtualBox;
+    HostDnsServiceBase *pMonitorImpl;
+
+    uint64_t uLastExtraDataPoll;
+    uint32_t fLaxComparison;
+    HostDnsInformation info;
+};
+
+
+HostDnsServiceBase::HostDnsServiceBase(bool fThreaded)
+    : m(NULL)
+{
+    m = new HostDnsServiceBase::Data(fThreaded);
+}
+
+HostDnsServiceBase::~HostDnsServiceBase()
+{
+    if (m)
+    {
+        delete m;
+        m = NULL;
+    }
+}
+
+/* static */
+HostDnsServiceBase *HostDnsServiceBase::createHostDnsMonitor(void)
+{
+    HostDnsServiceBase *pMonitor = NULL;
+
+#if defined (RT_OS_DARWIN)
+    pMonitor = new HostDnsServiceDarwin();
+#elif defined(RT_OS_WINDOWS)
+    pMonitor = new HostDnsServiceWin();
+#elif defined(RT_OS_LINUX)
+    pMonitor = new HostDnsServiceLinux();
+#elif defined(RT_OS_SOLARIS)
+    pMonitor =  new HostDnsServiceSolaris();
+#elif defined(RT_OS_FREEBSD)
+    pMonitor = new HostDnsServiceFreebsd();
+#elif defined(RT_OS_OS2)
+    pMonitor = new HostDnsServiceOs2();
+#else
+    pMonitor = new HostDnsServiceBase();
+#endif
+
+    return pMonitor;
+}
+
+HRESULT HostDnsServiceBase::init(HostDnsMonitorProxy *pProxy)
+{
+    LogRel(("HostDnsMonitor: initializing\n"));
+
+    AssertPtrReturn(pProxy, E_POINTER);
+    m->pProxy = pProxy;
+
+    if (m->fThreaded)
+    {
+        LogRel2(("HostDnsMonitor: starting thread ...\n"));
+
+        int rc = RTSemEventCreate(&m->hMonitorThreadEvent);
+        AssertRCReturn(rc, E_FAIL);
+
+        rc = RTThreadCreate(&m->hMonitorThread,
+                            HostDnsServiceBase::threadMonitorProc,
+                            this, 128 * _1K, RTTHREADTYPE_IO,
+                            RTTHREADFLAGS_WAITABLE, "dns-monitor");
+        AssertRCReturn(rc, E_FAIL);
+
+        RTSemEventWait(m->hMonitorThreadEvent, RT_INDEFINITE_WAIT);
+
+        LogRel2(("HostDnsMonitor: thread started\n"));
+    }
+
+    return S_OK;
+}
+
+void HostDnsServiceBase::uninit(void)
+{
+    LogRel(("HostDnsMonitor: shutting down ...\n"));
+
+    if (m->fThreaded)
+    {
+        LogRel2(("HostDnsMonitor: waiting for thread ...\n"));
+
+        const RTMSINTERVAL uTimeoutMs = 30 * 1000; /* 30s */
+
+        monitorThreadShutdown(uTimeoutMs);
+
+        int rc = RTThreadWait(m->hMonitorThread, uTimeoutMs, NULL);
+        if (RT_FAILURE(rc))
+            LogRel(("HostDnsMonitor: waiting for thread failed with rc=%Rrc\n", rc));
+
+        if (m->hMonitorThreadEvent != NIL_RTSEMEVENT)
+        {
+            RTSemEventDestroy(m->hMonitorThreadEvent);
+            m->hMonitorThreadEvent = NIL_RTSEMEVENT;
+        }
+    }
+
+    LogRel(("HostDnsMonitor: shut down\n"));
+}
+
+void HostDnsServiceBase::setInfo(const HostDnsInformation &info)
+{
+    if (m->pProxy != NULL)
+        m->pProxy->notify(info);
+}
+
+void HostDnsMonitorProxy::pollGlobalExtraData(void)
+{
+    VirtualBox *pVirtualBox = m->pVirtualBox;
+    if (RT_UNLIKELY(pVirtualBox == NULL))
+        return;
+
+    uint64_t uNow = RTTimeNanoTS();
+    if (uNow - m->uLastExtraDataPoll >= RT_NS_30SEC || m->uLastExtraDataPoll == 0)
+    {
+        m->uLastExtraDataPoll = uNow;
+
+        /*
+         * Should we ignore the order of DNS servers?
+         */
+        const com::Bstr bstrHostDNSOrderIgnoreKey("VBoxInternal2/HostDNSOrderIgnore");
+        com::Bstr bstrHostDNSOrderIgnore;
+        pVirtualBox->GetExtraData(bstrHostDNSOrderIgnoreKey.raw(),
+                                 bstrHostDNSOrderIgnore.asOutParam());
+        uint32_t fDNSOrderIgnore = 0;
+        if (bstrHostDNSOrderIgnore.isNotEmpty())
+        {
+            if (bstrHostDNSOrderIgnore != "0")
+                fDNSOrderIgnore = HostDnsInformation::IGNORE_SERVER_ORDER;
+        }
+
+        if (fDNSOrderIgnore != (m->fLaxComparison & HostDnsInformation::IGNORE_SERVER_ORDER))
+        {
+
+            m->fLaxComparison ^= HostDnsInformation::IGNORE_SERVER_ORDER;
+            LogRel(("HostDnsMonitor: %ls=%ls\n",
+                    bstrHostDNSOrderIgnoreKey.raw(),
+                    bstrHostDNSOrderIgnore.raw()));
+        }
+
+        /*
+         * Should we ignore changes to the domain name or the search list?
+         */
+        const com::Bstr bstrHostDNSSuffixesIgnoreKey("VBoxInternal2/HostDNSSuffixesIgnore");
+        com::Bstr bstrHostDNSSuffixesIgnore;
+        pVirtualBox->GetExtraData(bstrHostDNSSuffixesIgnoreKey.raw(),
+                                 bstrHostDNSSuffixesIgnore.asOutParam());
+        uint32_t fDNSSuffixesIgnore = 0;
+        if (bstrHostDNSSuffixesIgnore.isNotEmpty())
+        {
+            if (bstrHostDNSSuffixesIgnore != "0")
+                fDNSSuffixesIgnore = HostDnsInformation::IGNORE_SUFFIXES;
+        }
+
+        if (fDNSSuffixesIgnore != (m->fLaxComparison & HostDnsInformation::IGNORE_SUFFIXES))
+        {
+
+            m->fLaxComparison ^= HostDnsInformation::IGNORE_SUFFIXES;
+            LogRel(("HostDnsMonitor: %ls=%ls\n",
+                    bstrHostDNSSuffixesIgnoreKey.raw(),
+                    bstrHostDNSSuffixesIgnore.raw()));
+        }
+    }
+}
+
+void HostDnsServiceBase::onMonitorThreadInitDone(void)
+{
+    if (!m->fThreaded) /* If non-threaded, bail out, nothing to do here. */
+        return;
+
+    RTSemEventSignal(m->hMonitorThreadEvent);
+}
+
+DECLCALLBACK(int) HostDnsServiceBase::threadMonitorProc(RTTHREAD, void *pvUser)
+{
+    HostDnsServiceBase *pThis = static_cast<HostDnsServiceBase *>(pvUser);
+    AssertPtrReturn(pThis, VERR_INVALID_POINTER);
+    return pThis->monitorThreadProc();
+}
+
+/* HostDnsMonitorProxy */
+HostDnsMonitorProxy::HostDnsMonitorProxy()
+    : m(NULL)
+{
+}
+
+HostDnsMonitorProxy::~HostDnsMonitorProxy()
+{
+    uninit();
+}
+
+HRESULT HostDnsMonitorProxy::init(VirtualBox* aParent)
+{
+    AssertMsgReturn(m == NULL, ("DNS monitor proxy already initialized\n"), E_FAIL);
+
+    HostDnsServiceBase *pMonitorImpl = HostDnsServiceBase::createHostDnsMonitor();
+    AssertPtrReturn(pMonitorImpl, E_OUTOFMEMORY);
+
+    Assert(m == NULL); /* Paranoia. */
+    m = new HostDnsMonitorProxy::Data(pMonitorImpl, aParent);
+    AssertPtrReturn(m, E_OUTOFMEMORY);
+
+    return m->pMonitorImpl->init(this);
+}
+
+void HostDnsMonitorProxy::uninit(void)
+{
+    if (m)
+    {
+        if (m->pMonitorImpl)
+        {
+            m->pMonitorImpl->uninit();
+
+            delete m->pMonitorImpl;
+            m->pMonitorImpl = NULL;
+        }
+
+        delete m;
+        m = NULL;
+    }
+}
+
+void HostDnsMonitorProxy::notify(const HostDnsInformation &info)
+{
+    const bool fNotify = updateInfo(info);
+    if (fNotify)
+        m->pVirtualBox->i_onHostNameResolutionConfigurationChange();
+}
+
+HRESULT HostDnsMonitorProxy::GetNameServers(std::vector<com::Utf8Str> &aNameServers)
+{
+    AssertReturn(m != NULL, E_FAIL);
+    RTCLock grab(m_LockMtx);
+
+    LogRel(("HostDnsMonitorProxy::GetNameServers:\n"));
+    dumpHostDnsStrVector("name server", m->info.servers);
+
+    detachVectorOfString(m->info.servers, aNameServers);
+
+    return S_OK;
+}
+
+HRESULT HostDnsMonitorProxy::GetDomainName(com::Utf8Str *pDomainName)
+{
+    AssertReturn(m != NULL, E_FAIL);
+    RTCLock grab(m_LockMtx);
+
+    LogRel(("HostDnsMonitorProxy::GetDomainName: %s\n",
+            m->info.domain.empty() ? "no domain set" : m->info.domain.c_str()));
+
+    *pDomainName = m->info.domain.c_str();
+
+    return S_OK;
+}
+
+HRESULT HostDnsMonitorProxy::GetSearchStrings(std::vector<com::Utf8Str> &aSearchStrings)
+{
+    AssertReturn(m != NULL, E_FAIL);
+    RTCLock grab(m_LockMtx);
+
+    LogRel(("HostDnsMonitorProxy::GetSearchStrings:\n"));
+    dumpHostDnsStrVector("search string", m->info.searchList);
+
+    detachVectorOfString(m->info.searchList, aSearchStrings);
+
+    return S_OK;
+}
+
+bool HostDnsMonitorProxy::updateInfo(const HostDnsInformation &info)
+{
+    LogRel(("HostDnsMonitor: updating information\n"));
+    RTCLock grab(m_LockMtx);
+
+    if (info.equals(m->info))
+    {
+        LogRel(("HostDnsMonitor: unchanged\n"));
+        return false;
+    }
+
+    pollGlobalExtraData();
+
+    LogRel(("HostDnsMonitor: old information\n"));
+    dumpHostDnsInformation(m->info);
+    LogRel(("HostDnsMonitor: new information\n"));
+    dumpHostDnsInformation(info);
+
+    bool fIgnore = m->fLaxComparison != 0 && info.equals(m->info, m->fLaxComparison);
+    m->info = info;
+
+    if (fIgnore)
+    {
+        LogRel(("HostDnsMonitor: lax comparison %#x, not notifying\n", m->fLaxComparison));
+        return false;
+    }
+
+    return true;
+}
+