HostDnsServiceWin.cpp@ 53151

Last change on this file since 53151 was 53151, checked in by vboxsync, 10 years ago
Main/HostDnsService: bring back Windows changes of r96331 but with plain std::string in HostDnsInformation and using explicit Unicode API and wchar_t when dealing with registry (we always compile with -DUNICODE, so no need for TCHAR shim). No changes to the original except minor const correctness tweaks.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 19.3 KB

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1	/* $Id: HostDnsServiceWin.cpp 53151 2014-10-27 12:34:31Z vboxsync $ */
2	/** @file
3	* Host DNS listener for Windows.
4	*/
5
6	/*
7	* Copyright (C) 2014 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18	#include <VBox/com/string.h>
19	#include <VBox/com/ptr.h>
20	#include <VBox/log.h>
21
22	#include <iprt/assert.h>
23	#include <iprt/err.h>
24
25	#include <Windows.h>
26
27	#include <string>
28	#include <sstream>
29	#include <vector>
30	#include "../HostDnsService.h"
31
32	/* In order to monitor DNS setting updates we need to receive notification about
33	* Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\* keys changes.
34	* Since it is not possible to use patterns when subscribing key changes, we need to find valid paths for all such
35	* keys manually and subscribe to changes one by one (see enumerateSubTree()). */
36	const wchar_t HostDnsServiceWin::pwcKeyRoot[] = L"SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces";
37
38
39	HostDnsServiceWin::HostDnsServiceWin()
40	: HostDnsMonitor(true),
41	m_aWarehouse(),
42	m_hostInfoCache(),
43	m_fInitialized(false)
44	{
45	/* Add monitor destroy event.
46	* This event should have index '0' at the events array in order to separate it from
47	* DNS and tree change events. When this event occurs all resources should be released. */
48	if (subscribeTo(NULL, NULL, 0))
49	{
50	/* Add registry tree change event and corresponding key.
51	* This event should have index '1' at the events array in order to separate it from DNS events.
52	* When this event occurs it means there are changes in the list of available network interfaces.
53	* Network interfaces should be re-enumerated, all DNS events and keys data should re-initialized. */
54	if (subscribeTo(pwcKeyRoot, NULL, REG_NOTIFY_CHANGE_NAME))
55	{
56	/* Enumerate all available network interfaces, create events and corresponding keys and perform subscription. */
57	if (enumerateSubTree())
58	{
59	updateInfo(NULL);
60	m_fInitialized = true;
61	return;
62	}
63	else
64	LogRel(("WARNING: cannot set up monitor properly (3); monitor now disabled.\n"));
65	}
66	else
67	/* Too bad we can't even subscribe to notifications about network interfaces changes. */
68	LogRel(("WARNING: cannot set up monitor properly (2); monitor now disabled.\n"));
69	}
70	else
71	/* Too bad we can't even subscribe to destroy event. */
72	LogRel(("WARNING: cannot set up monitor properly (1); monitor now disabled.\n"));
73
74	releaseResources();
75	}
76
77
78	HostDnsServiceWin::~HostDnsServiceWin()
79	{
80	monitorThreadShutdown();
81	releaseResources();
82	m_fInitialized = false;
83	}
84
85
86	bool HostDnsServiceWin::releaseWarehouseItem(int idxItem)
87	{
88	bool rc = true;
89	/* We do not check if idxItem is in valid range of m_aWarehouse here
90	* (a bit of performance optimization), so make sure you provided a valid value! */
91	struct Item oTmpItem = m_aWarehouse[idxItem];
92
93	/* Non-zero return code means ResetEvent() succeeded. */
94	rc = ResetEvent(oTmpItem.hEvent) != 0;
95	if (!rc) LogRel(("Failed to reset event (idxItem=%d); monitor unstable (rc=%d).\n", idxItem, GetLastError()));
96	CloseHandle(oTmpItem.hEvent);
97	oTmpItem.hEvent = NULL;
98
99	RegCloseKey(oTmpItem.hKey);
100	oTmpItem.hKey = NULL;
101
102	Log2(("Unsubscribed from %ls notifications\n", oTmpItem.wcsInterface));
103
104	m_aWarehouse.erase(m_aWarehouse.begin() + idxItem);
105
106	return rc;
107	}
108
109
110	bool HostDnsServiceWin::dropSubTreeNotifications()
111	{
112	bool rc = true;
113	/* Any sub-tree events we subscribed? */
114	if (m_aWarehouse.size() > VBOX_OFFSET_SUBTREE_EVENTS)
115	/* Going from the end to the beginning. */
116	for (int idxItem = (int)m_aWarehouse.size() - 1; idxItem >= VBOX_OFFSET_SUBTREE_EVENTS; idxItem--)
117	rc &= releaseWarehouseItem(idxItem);
118
119	size_t cElementsLeft = m_aWarehouse.size();
120	if (cElementsLeft != VBOX_OFFSET_SUBTREE_EVENTS)
121	{
122	LogRel(("DNS monitor unstable; %d events left after dropping.\n", (int)cElementsLeft - VBOX_OFFSET_SUBTREE_EVENTS));
123	return false;
124	}
125
126	return rc;
127	}
128
129
130	void HostDnsServiceWin::releaseResources()
131	{
132	/* First, drop notifications subscription for sub-tree keys. */
133	dropSubTreeNotifications();
134
135	/* Then release notification about tree structure changes. */
136	if (m_aWarehouse.size() > VBOX_OFFSET_TREE_EVENT)
137	releaseWarehouseItem(VBOX_OFFSET_TREE_EVENT);
138
139	/* Release shutdown event. */
140	if (m_aWarehouse.size() > VBOX_OFFSET_SHUTDOWN_EVENT)
141	releaseWarehouseItem(VBOX_OFFSET_SHUTDOWN_EVENT);
142
143	AssertReturnVoid(m_aWarehouse.size() == 0);
144	}
145
146
147	bool HostDnsServiceWin::subscribeTo(const wchar_t wcsPath, const wchar_t wcsInterface, DWORD fFilter)
148	{
149	HKEY hTmpKey = NULL;
150	HANDLE hTmpEvent = NULL;
151
152	/* Do not add more than MAXIMUM_WAIT_OBJECTS items to the array due to WaitForMultipleObjects() limitation. */
153	if ((m_aWarehouse.size() + 1 /* the array size if we would add an extra item */ ) > MAXIMUM_WAIT_OBJECTS)
154	{
155	LogRel(("Too many items to monitor.\n"));
156	return false;
157	}
158
159	hTmpEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
160	if (!hTmpEvent)
161	return false;
162
163	/* wcsPath might not be specified if we want to subscribe to the termination event. In this case
164	* it is assumed that this is the first issued subscription request (i.e., m_aWarehouse.size() == 0). */
165	if (wcsPath)
166	{
167	LONG rc;
168	/* Open registry key itself. */
169	rc = RegOpenKeyExW(HKEY_LOCAL_MACHINE, wcsPath, 0, KEY_READ \| KEY_NOTIFY, &hTmpKey);
170	if (rc == ERROR_SUCCESS)
171	{
172	/* Link registry key and notification event. */
173	rc = RegNotifyChangeKeyValue(hTmpKey, TRUE, fFilter, hTmpEvent, TRUE);
174	if (rc != ERROR_SUCCESS)
175	{
176	/* Don't leak! */
177	RegCloseKey(hTmpKey);
178	LogRel(("Unable to register key notification (rc=0x%X).\n", rc));
179	}
180	}
181	else
182	LogRel(("Unable to open key (rc=0x%X)\n", rc));
183
184	/* All good so far? */
185	if (rc != ERROR_SUCCESS)
186	{
187	LogRel(("WARNING: unable to set up %ls registry key notifications.\n", wcsPath));
188	CloseHandle(hTmpEvent);
189	return false;
190	}
191	}
192	else if (m_aWarehouse.size() > 0)
193	{
194	LogRel(("Subscription to termination event already established.\n"));
195	CloseHandle(hTmpEvent);
196	return false;
197	}
198
199	/* Finally, construct array item and queue it. */
200	struct Item oTmpItem = { hTmpKey, hTmpEvent, NULL };
201
202	/* Sub-tree keys should provide interface name (UUID). This is needed in order to
203	* collect all useful network settings to HostDnsInformation storage object to provide it to parent class. */
204	if (wcsInterface)
205	wcscpy(oTmpItem.wcsInterface, wcsInterface);
206
207	if (wcsPath)
208	Log2(("Subscription to %ls established.\n", wcsPath));
209
210	m_aWarehouse.push_back(oTmpItem);
211
212	return true;
213	}
214
215
216	bool HostDnsServiceWin::enumerateSubTree()
217	{
218	LONG rc = 0;
219	HKEY hTmpKey;
220	DWORD cSubKeys = 0;
221	DWORD cbSubKeyNameMax = 0;
222
223	/* Enumerate all the available interfaces. */
224	rc = RegOpenKeyExW(HKEY_LOCAL_MACHINE, pwcKeyRoot, 0, KEY_READ, &hTmpKey);
225	if (rc == ERROR_SUCCESS)
226	{
227	/* Get info about amount of available network interfaces. */
228	rc = RegQueryInfoKeyW(hTmpKey, NULL, NULL, NULL, &cSubKeys, &cbSubKeyNameMax, NULL, NULL, NULL, NULL, NULL, NULL);
229	if (rc == ERROR_SUCCESS)
230	{
231	/* Now iterate over interfaces if:
232	* 1) there are interfaces available and
233	* 2) maximum length of an interface name conforms to our buffer allocation size. */
234	if (cSubKeys > 0 && cbSubKeyNameMax <= VBOX_KEY_NAME_LEN_MAX)
235	{
236	wchar_t sSubKeyName[VBOX_KEY_NAME_LEN_MAX];
237	for (DWORD idxSubKey = 0; idxSubKey < cSubKeys; idxSubKey++)
238	{
239	rc = RegEnumKeyW(hTmpKey, idxSubKey, sSubKeyName, VBOX_KEY_NAME_LEN_MAX);
240	if (rc == ERROR_SUCCESS)
241	{
242	/* Since we already know interface name (actually UUID), construct full registry path here. */
243	wchar_t sSubKeyFullPath[VBOX_KEY_NAME_LEN_MAX];
244	RT_ZERO(sSubKeyFullPath);
245	wcscpy(sSubKeyFullPath, pwcKeyRoot);
246	rc = wcscat_s(sSubKeyFullPath, VBOX_KEY_NAME_LEN_MAX, L"\\");
247	rc \|= wcscat_s(sSubKeyFullPath, VBOX_KEY_NAME_LEN_MAX, sSubKeyName);
248	if (rc == 0)
249	subscribeTo(sSubKeyFullPath, sSubKeyName, REG_NOTIFY_CHANGE_LAST_SET);
250	}
251	else
252	LogRel(("Unable to open interfaces list (1).\n"));
253	}
254	RegCloseKey(hTmpKey);
255	return true;
256	}
257	else
258	LogRel(("Unable to open interfaces list (2).\n"));
259	}
260	else
261	LogRel(("Unable to open interfaces list (3).\n"));
262	RegCloseKey(hTmpKey);
263	}
264	else
265	LogRel(("Unable to open interfaces list (4).\n"));
266	return false;
267	}
268
269
270	HRESULT HostDnsServiceWin::init()
271	{
272	HRESULT hrc = HostDnsMonitor::init();
273	AssertComRCReturn(hrc, hrc);
274
275	return updateInfo(NULL);
276	}
277
278
279	void HostDnsServiceWin::monitorThreadShutdown()
280	{
281	AssertReturnVoid(m_aWarehouse.size() > VBOX_OFFSET_SHUTDOWN_EVENT);
282	SetEvent(m_aWarehouse[VBOX_OFFSET_SHUTDOWN_EVENT].hEvent);
283	}
284
285
286	void HostDnsServiceWin::extendVectorWithStrings(std::vector<std::string> &pVectorToExtend, const std::wstring &wcsParameter)
287	{
288	std::wstringstream wcsStream(wcsParameter);
289	std::wstring wcsSubString;
290
291	while (std::getline(wcsStream, wcsSubString, L' '))
292	{
293	std::string str = std::_Narrow_str(wcsSubString);
294	pVectorToExtend.push_back(str);
295	}
296	}
297
298	#ifdef DEBUG
299	static void hostDnsWinDumpList(const std::vector<std::string> &awcszValues)
300	{
301	for (int idxItem = 0; idxItem < awcszValues.size(); idxItem++)
302	{
303	LogRel(("%s\n", awcszValues[idxItem].c_str()));
304	}
305	}
306	#endif /* DEBUG */
307
308
309	HRESULT HostDnsServiceWin::updateInfo(uint8_t *fWhatsChanged)
310	{
311	HostDnsInformation pHostDnsInfo;
312	RT_ZERO(pHostDnsInfo);
313
314	/* Any interfaces available? */
315	if (m_aWarehouse.size() > VBOX_OFFSET_SUBTREE_EVENTS)
316	{
317	/* Walk across all the available interfaces and collect network configuration data:
318	* domain name, name servers and search list. */
319	for (int idxKey = VBOX_OFFSET_SUBTREE_EVENTS; idxKey < m_aWarehouse.size(); idxKey++)
320	{
321	LONG rc;
322
323	/* Get number of key values. */
324	DWORD cValues = 0;
325	rc = RegQueryInfoKeyW(m_aWarehouse[idxKey].hKey, NULL, NULL, NULL, NULL, NULL, NULL, &cValues, NULL, NULL, NULL, NULL);
326	if (rc == ERROR_SUCCESS)
327	{
328	for (DWORD idxValue = 0; idxValue < cValues; idxValue++)
329	{
330	wchar_t wcsValueName[VBOX_KEY_NAME_LEN_MAX];
331	DWORD cbValueName = VBOX_KEY_NAME_LEN_MAX;
332	wchar_t wcsData[VBOX_KEY_NAME_LEN_MAX];
333	DWORD cbData = VBOX_KEY_NAME_LEN_MAX;
334
335	/* Walk across all the properties of given interface. */
336	rc = RegEnumValueW(m_aWarehouse[idxKey].hKey, idxValue, wcsValueName, &cbValueName, 0, NULL, (LPBYTE)wcsData, &cbData);
337	if (rc == ERROR_SUCCESS)
338	{
339
340	if (( wcscmp(wcsValueName, L"Domain") == 0
341	\|\| wcscmp(wcsValueName, L"DhcpDomain") == 0)
342	&& wcslen(wcsData) > 0)
343	{
344	/* We rely on that fact that Windows host cannot be a member of more than one domain in the same time! */
345	if (pHostDnsInfo.domain.empty())
346	pHostDnsInfo.domain = std::_Narrow_str(std::wstring(wcsData));
347	}
348	else if (( wcscmp(wcsValueName, L"NameServer") == 0
349	\|\| wcscmp(wcsValueName, L"DhcpNameServer") == 0)
350	&& wcslen(wcsData) > 0)
351	{
352	extendVectorWithStrings(pHostDnsInfo.servers, std::wstring(wcsData));
353	}
354	else if (wcscmp(wcsValueName, L"SearchList") == 0
355	&& wcslen(wcsData) > 0)
356	{
357	extendVectorWithStrings(pHostDnsInfo.searchList, std::wstring(wcsData));
358	}
359	}
360	}
361	}
362	}
363
364	uint8_t fChanged = VBOX_EVENT_NO_CHANGES;
365	/* Compare cached network settings and newly obtained ones. */
366	if (pHostDnsInfo.servers != m_hostInfoCache.servers)
367	{
368	#ifdef DEBUG
369	LogRel(("Servers changed from:\n"));
370	hostDnsWinDumpList(m_hostInfoCache.servers);
371	LogRel(("to:\n"));
372	hostDnsWinDumpList(pHostDnsInfo.servers);
373	#endif /* DEBUG */
374	fChanged \|= VBOX_EVENT_SERVERS_CHANGED;
375	}
376
377	if (pHostDnsInfo.domain != m_hostInfoCache.domain)
378	{
379	#ifdef DEBUG
380	LogRel(("Domain changed: [%s]->[%s].\n",
381	m_hostInfoCache.domain.empty() ? "NONE" : m_hostInfoCache.domain.c_str(),
382	pHostDnsInfo.domain.c_str()));
383	#endif /* DEBUG */
384	fChanged \|= VBOX_EVENT_DOMAIN_CHANGED;
385	}
386
387	if (pHostDnsInfo.searchList != m_hostInfoCache.searchList)
388	{
389	#ifdef DEBUG
390	LogRel(("SearchList changed from:\n"));
391	hostDnsWinDumpList(m_hostInfoCache.searchList);
392	LogRel(("to:\n"));
393	hostDnsWinDumpList(pHostDnsInfo.searchList);
394	#endif /* DEBUG */
395	fChanged \|= VBOX_EVENT_SEARCHLIST_CHANGED;
396	}
397
398	/* Provide info about changes if requested. */
399	if (fWhatsChanged)
400	*fWhatsChanged = fChanged;
401
402	/* Update host network configuration cache. */
403	m_hostInfoCache.servers.clear();
404	m_hostInfoCache.servers = pHostDnsInfo.servers;
405	m_hostInfoCache.domain.clear();
406	m_hostInfoCache.domain.assign(pHostDnsInfo.domain);
407	m_hostInfoCache.searchList.clear();
408	m_hostInfoCache.searchList = pHostDnsInfo.searchList;
409
410	HostDnsMonitor::setInfo(pHostDnsInfo);
411	}
412
413	return S_OK;
414	}
415
416
417	void HostDnsServiceWin::getEventHandles(HANDLE *ahEvents)
418	{
419	AssertReturnVoid(m_aWarehouse.size() > 0);
420	for (int idxHandle = 0; idxHandle < m_aWarehouse.size(); idxHandle++)
421	ahEvents[idxHandle] = m_aWarehouse[idxHandle].hEvent;
422	}
423
424
425	int HostDnsServiceWin::monitorWorker()
426	{
427	monitorThreadInitializationDone();
428
429	uint8_t fWhatsChabged = VBOX_EVENT_NO_CHANGES;
430
431	if (!m_fInitialized)
432	{
433	LogRel(("Host DNS monitor was not initialized properly.\n"));
434	return VERR_INTERNAL_ERROR;
435	}
436
437	HANDLE ahEvents[MAXIMUM_WAIT_OBJECTS];
438
439	while (true)
440	{
441	/* Each new iteration we need to update event handles list we monitor. */
442	RT_ZERO(ahEvents);
443	getEventHandles(ahEvents);
444
445	DWORD rc = WaitForMultipleObjects((DWORD)m_aWarehouse.size(), ahEvents, FALSE, INFINITE);
446
447	AssertMsgReturn(rc != WAIT_FAILED,
448	("WaitForMultipleObjects failed (%d) to wait! Please debug",
449	GetLastError()), VERR_INTERNAL_ERROR);
450
451	/* Shutdown requested. */
452	if (rc == (WAIT_OBJECT_0 + VBOX_OFFSET_SHUTDOWN_EVENT)) break;
453	/* Interfaces amount changed. */
454	else if (rc == (WAIT_OBJECT_0 + VBOX_OFFSET_TREE_EVENT))
455	{
456	Log2(("Network interfaces amount changed.\n"));
457
458	/* Drop interface events. */
459	if (dropSubTreeNotifications())
460	{
461	/* Drop event which is corresponds to interfaces tree changes. */
462	if (releaseWarehouseItem(VBOX_OFFSET_TREE_EVENT))
463	{
464	/* Restart interface tree monitoring. */
465	if (subscribeTo(pwcKeyRoot, NULL, REG_NOTIFY_CHANGE_NAME))
466	{
467	/* Restart interface events. */
468	if (enumerateSubTree())
469	{
470	Log2(("Monitor restarted successfully.\n"));
471	fWhatsChabged = VBOX_EVENT_NO_CHANGES;
472	updateInfo(&fWhatsChabged);
473	if (fWhatsChabged & VBOX_EVENT_SERVERS_CHANGED)
474	{
475	LogRel(("Notification sent (1).\n"));
476	notifyAll();
477	}
478	continue;
479	}
480	else
481	LogRel(("Monitor unstable: failed to subscribe network configuration changes.\n"));
482	}
483	else
484	LogRel(("Monitor unstable: failed to subscribe interface changes.\n"));
485	}
486	else
487	LogRel(("Monitor unstable: failed to unsubscribe from interfaces amount changes.\n"));
488	}
489	else
490	LogRel(("Monitor unstable: failed to unsubscribe from previous notifications.\n"));
491
492	/* If something went wrong, we break monitoring. */
493	break;
494
495	}
496	/* DNS update events range. */
497	else if (rc >= (WAIT_OBJECT_0 + VBOX_OFFSET_SUBTREE_EVENTS) &&
498	rc < (WAIT_OBJECT_0 + m_aWarehouse.size()))
499	{
500	Log2(("Network setting has changed at interface %ls.\n", m_aWarehouse[rc - WAIT_OBJECT_0].wcsInterface));
501
502	/* Drop previous notifications first. */
503	if (dropSubTreeNotifications())
504	{
505	/* Re-subscribe. */
506	if (enumerateSubTree())
507	{
508	Log2(("Restart monitoring.\n"));
509	fWhatsChabged = VBOX_EVENT_NO_CHANGES;
510	updateInfo(&fWhatsChabged);
511	if (fWhatsChabged & VBOX_EVENT_SERVERS_CHANGED)
512	{
513	LogRel(("Notification sent (2).\n"));
514	notifyAll();
515	}
516	continue;
517	}
518	else
519	LogRel(("WARNING: Monitor unstable: unable to re-subscribe to notifications.\n"));
520	}
521	else
522	LogRel(("WARNING: Monitor unstable: failed to unsubscribe from previous notifications.\n"));
523
524	/* If something went wrong, we stop monitoring. */
525	break;
526	}
527	else
528	AssertMsgFailedReturn(("WaitForMultipleObjects returns out of bound (%d) index %d. Please debug!\n", m_aWarehouse.size(), rc), VERR_INTERNAL_ERROR);
529	}
530	LogRel(("Monitor thread exited.\n"));
531	return VINF_SUCCESS;
532	}

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source: vbox/trunk/src/VBox/Main/src-server/win/HostDnsServiceWin.cpp@ 53151

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