VBoxServiceControl.cpp@ 66891

Last change on this file since 66891 was 62882, checked in by vboxsync, 8 years ago
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1	/* $Id: VBoxServiceControl.cpp 62882 2016-08-02 15:31:02Z vboxsync $ */
2	/** @file
3	* VBoxServiceControl - Host-driven Guest Control.
4	*/
5
6	/*
7	* Copyright (C) 2012-2016 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	/** @page pg_vgsvc_gstctrl VBoxService - Guest Control
19	*
20	* The Guest Control subservice helps implementing the IGuest APIs.
21	*
22	* The communication between this service (and its children) and IGuest goes
23	* over the HGCM GuestControl service.
24	*
25	* The IGuest APIs provides means to manipulate (control) files, directories,
26	* symbolic links and processes within the guest. Most of these means requires
27	* credentials of a guest OS user to operate, though some restricted ones
28	* operates directly as the VBoxService user (root / system service account).
29	*
30	* The current design is that a subprocess is spawned for handling operations as
31	* a given user. This process is represented as IGuestSession in the API. The
32	* subprocess will be spawned as the given use, giving up the privileges the
33	* parent subservice had.
34	*
35	* It will try handle as many of the operations directly from within the
36	* subprocess, but for more complicated things (or things that haven't yet been
37	* converted), it will spawn a helper process that does the actual work.
38	*
39	* These helpers are the typically modeled on similar unix core utilities, like
40	* mkdir, rm, rmdir, cat and so on. The helper tools can also be launched
41	* directly from VBoxManage by the user by prepending the 'vbox_' prefix to the
42	* unix command.
43	*
44	*/
45
46
47	/*********************************************************************************************************************************
48	* Header Files *
49	*********************************************************************************************************************************/
50	#include <iprt/asm.h>
51	#include <iprt/assert.h>
52	#include <iprt/env.h>
53	#include <iprt/file.h>
54	#include <iprt/getopt.h>
55	#include <iprt/mem.h>
56	#include <iprt/path.h>
57	#include <iprt/process.h>
58	#include <iprt/semaphore.h>
59	#include <iprt/thread.h>
60	#include <VBox/VBoxGuestLib.h>
61	#include <VBox/HostServices/GuestControlSvc.h>
62	#include "VBoxServiceInternal.h"
63	#include "VBoxServiceControl.h"
64	#include "VBoxServiceUtils.h"
65
66	using namespace guestControl;
67
68
69	/*********************************************************************************************************************************
70	* Global Variables *
71	*********************************************************************************************************************************/
72	/** The control interval (milliseconds). */
73	static uint32_t g_msControlInterval = 0;
74	/** The semaphore we're blocking our main control thread on. */
75	static RTSEMEVENTMULTI g_hControlEvent = NIL_RTSEMEVENTMULTI;
76	/** The VM session ID. Changes whenever the VM is restored or reset. */
77	static uint64_t g_idControlSession;
78	/** The guest control service client ID. */
79	static uint32_t g_uControlSvcClientID = 0;
80	#if 0 /** @todo process limit */
81	/** How many started guest processes are kept into memory for supplying
82	* information to the host. Default is 256 processes. If 0 is specified,
83	* the maximum number of processes is unlimited. */
84	static uint32_t g_uControlProcsMaxKept = 256;
85	#endif
86	/** List of guest control session threads (VBOXSERVICECTRLSESSIONTHREAD).
87	* A guest session thread represents a forked guest session process
88	* of VBoxService. */
89	RTLISTANCHOR g_lstControlSessionThreads;
90	/** The local session object used for handling all session-related stuff.
91	* When using the legacy guest control protocol (< 2), this session runs
92	* under behalf of the VBoxService main process. On newer protocol versions
93	* each session is a forked version of VBoxService using the appropriate
94	* user credentials for opening a guest session. These forked sessions then
95	* are kept in VBOXSERVICECTRLSESSIONTHREAD structures. */
96	VBOXSERVICECTRLSESSION g_Session;
97
98
99	/*********************************************************************************************************************************
100	* Internal Functions *
101	*********************************************************************************************************************************/
102	static int vgsvcGstCtrlHandleSessionOpen(PVBGLR3GUESTCTRLCMDCTX pHostCtx);
103	static int vgsvcGstCtrlHandleSessionClose(PVBGLR3GUESTCTRLCMDCTX pHostCtx);
104	static void vgsvcGstCtrlShutdown(void);
105
106
107	/**
108	* @interface_method_impl{VBOXSERVICE,pfnPreInit}
109	*/
110	static DECLCALLBACK(int) vgsvcGstCtrlPreInit(void)
111	{
112	int rc;
113	#ifdef VBOX_WITH_GUEST_PROPS
114	/*
115	* Read the service options from the VM's guest properties.
116	* Note that these options can be overridden by the command line options later.
117	*/
118	uint32_t uGuestPropSvcClientID;
119	rc = VbglR3GuestPropConnect(&uGuestPropSvcClientID);
120	if (RT_FAILURE(rc))
121	{
122	if (rc == VERR_HGCM_SERVICE_NOT_FOUND) /* Host service is not available. */
123	{
124	VGSvcVerbose(0, "Guest property service is not available, skipping\n");
125	rc = VINF_SUCCESS;
126	}
127	else
128	VGSvcError("Failed to connect to the guest property service, rc=%Rrc\n", rc);
129	}
130	else
131	VbglR3GuestPropDisconnect(uGuestPropSvcClientID);
132
133	if (rc == VERR_NOT_FOUND) /* If a value is not found, don't be sad! */
134	rc = VINF_SUCCESS;
135	#else
136	/* Nothing to do here yet. */
137	rc = VINF_SUCCESS;
138	#endif
139
140	if (RT_SUCCESS(rc))
141	{
142	/* Init session object. */
143	rc = VGSvcGstCtrlSessionInit(&g_Session, 0 /* Flags */);
144	}
145
146	return rc;
147	}
148
149
150	/**
151	* @interface_method_impl{VBOXSERVICE,pfnOption}
152	*/
153	static DECLCALLBACK(int) vgsvcGstCtrlOption(const char ppszShort, int argc, char argv, int *pi)
154	{
155	int rc = -1;
156	if (ppszShort)
157	/* no short options */;
158	else if (!strcmp(argv[*pi], "--control-interval"))
159	rc = VGSvcArgUInt32(argc, argv, "", pi,
160	&g_msControlInterval, 1, UINT32_MAX - 1);
161	#ifdef DEBUG
162	else if (!strcmp(argv[*pi], "--control-dump-stdout"))
163	{
164	g_Session.fFlags \|= VBOXSERVICECTRLSESSION_FLAG_DUMPSTDOUT;
165	rc = 0; /* Flag this command as parsed. */
166	}
167	else if (!strcmp(argv[*pi], "--control-dump-stderr"))
168	{
169	g_Session.fFlags \|= VBOXSERVICECTRLSESSION_FLAG_DUMPSTDERR;
170	rc = 0; /* Flag this command as parsed. */
171	}
172	#endif
173	return rc;
174	}
175
176
177	/**
178	* @interface_method_impl{VBOXSERVICE,pfnInit}
179	*/
180	static DECLCALLBACK(int) vgsvcGstCtrlInit(void)
181	{
182	/*
183	* If not specified, find the right interval default.
184	* Then create the event sem to block on.
185	*/
186	if (!g_msControlInterval)
187	g_msControlInterval = 1000;
188
189	int rc = RTSemEventMultiCreate(&g_hControlEvent);
190	AssertRCReturn(rc, rc);
191
192	VbglR3GetSessionId(&g_idControlSession);
193	/* The status code is ignored as this information is not available with VBox < 3.2.10. */
194
195	if (RT_SUCCESS(rc))
196	rc = VbglR3GuestCtrlConnect(&g_uControlSvcClientID);
197	if (RT_SUCCESS(rc))
198	{
199	VGSvcVerbose(3, "Guest control service client ID=%RU32\n", g_uControlSvcClientID);
200
201	/* Init session thread list. */
202	RTListInit(&g_lstControlSessionThreads);
203	}
204	else
205	{
206	/* If the service was not found, we disable this service without
207	causing VBoxService to fail. */
208	if (rc == VERR_HGCM_SERVICE_NOT_FOUND) /* Host service is not available. */
209	{
210	VGSvcVerbose(0, "Guest control service is not available\n");
211	rc = VERR_SERVICE_DISABLED;
212	}
213	else
214	VGSvcError("Failed to connect to the guest control service! Error: %Rrc\n", rc);
215	RTSemEventMultiDestroy(g_hControlEvent);
216	g_hControlEvent = NIL_RTSEMEVENTMULTI;
217	}
218	return rc;
219	}
220
221
222	/**
223	* @interface_method_impl{VBOXSERVICE,pfnWorker}
224	*/
225	static DECLCALLBACK(int) vgsvcGstCtrlWorker(bool volatile *pfShutdown)
226	{
227	/*
228	* Tell the control thread that it can continue
229	* spawning services.
230	*/
231	RTThreadUserSignal(RTThreadSelf());
232	Assert(g_uControlSvcClientID > 0);
233
234	int rc = VINF_SUCCESS;
235
236	/* Allocate a scratch buffer for commands which also send
237	* payload data with them. */
238	uint32_t cbScratchBuf = _64K; /** @todo Make buffer size configurable via guest properties/argv! */
239	AssertReturn(RT_IS_POWER_OF_TWO(cbScratchBuf), VERR_INVALID_PARAMETER);
240	uint8_t pvScratchBuf = (uint8_t)RTMemAlloc(cbScratchBuf);
241	AssertReturn(pvScratchBuf, VERR_NO_MEMORY);
242
243	VBGLR3GUESTCTRLCMDCTX ctxHost = { g_uControlSvcClientID };
244	/* Set default protocol version to 1. */
245	ctxHost.uProtocol = 1;
246
247	int cRetrievalFailed = 0; /* Number of failed message retrievals in a row. */
248	for (;;)
249	{
250	VGSvcVerbose(3, "Waiting for host msg ...\n");
251	uint32_t uMsg = 0;
252	uint32_t cParms = 0;
253	rc = VbglR3GuestCtrlMsgWaitFor(g_uControlSvcClientID, &uMsg, &cParms);
254	if (rc == VERR_TOO_MUCH_DATA)
255	{
256	#ifdef DEBUG
257	VGSvcVerbose(4, "Message requires %ld parameters, but only 2 supplied -- retrying request (no error!)...\n",
258	cParms);
259	#endif
260	rc = VINF_SUCCESS; /* Try to get "real" message in next block below. */
261	}
262	else if (RT_FAILURE(rc))
263	{
264	/* Note: VERR_GEN_IO_FAILURE seems to be normal if ran into timeout. */
265	VGSvcError("Getting host message failed with %Rrc\n", rc);
266
267	/* Check for VM session change. */
268	uint64_t idNewSession = g_idControlSession;
269	int rc2 = VbglR3GetSessionId(&idNewSession);
270	if ( RT_SUCCESS(rc2)
271	&& (idNewSession != g_idControlSession))
272	{
273	VGSvcVerbose(1, "The VM session ID changed\n");
274	g_idControlSession = idNewSession;
275
276	/* Close all opened guest sessions -- all context IDs, sessions etc.
277	* are now invalid. */
278	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
279	AssertRC(rc2);
280
281	/* Do a reconnect. */
282	VGSvcVerbose(1, "Reconnecting to HGCM service ...\n");
283	rc2 = VbglR3GuestCtrlConnect(&g_uControlSvcClientID);
284	if (RT_SUCCESS(rc2))
285	{
286	VGSvcVerbose(3, "Guest control service client ID=%RU32\n", g_uControlSvcClientID);
287	cRetrievalFailed = 0;
288	continue; /* Skip waiting. */
289	}
290	else
291	{
292	VGSvcError("Unable to re-connect to HGCM service, rc=%Rrc, bailing out\n", rc);
293	break;
294	}
295	}
296
297	if (++cRetrievalFailed > 16) /** @todo Make this configurable? */
298	{
299	VGSvcError("Too many failed attempts in a row to get next message, bailing out\n");
300	break;
301	}
302
303	RTThreadSleep(1000); /* Wait a bit before retrying. */
304	}
305
306	if (RT_SUCCESS(rc))
307	{
308	VGSvcVerbose(4, "Msg=%RU32 (%RU32 parms) retrieved\n", uMsg, cParms);
309	cRetrievalFailed = 0; /* Reset failed retrieval count. */
310
311	/* Set number of parameters for current host context. */
312	ctxHost.uNumParms = cParms;
313
314	/* Check for VM session change. */
315	uint64_t idNewSession = g_idControlSession;
316	int rc2 = VbglR3GetSessionId(&idNewSession);
317	if ( RT_SUCCESS(rc2)
318	&& (idNewSession != g_idControlSession))
319	{
320	VGSvcVerbose(1, "The VM session ID changed\n");
321	g_idControlSession = idNewSession;
322
323	/* Close all opened guest sessions -- all context IDs, sessions etc.
324	* are now invalid. */
325	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
326	AssertRC(rc2);
327	}
328
329	switch (uMsg)
330	{
331	case HOST_CANCEL_PENDING_WAITS:
332	VGSvcVerbose(1, "We were asked to quit ...\n");
333	break;
334
335	case HOST_SESSION_CREATE:
336	rc = vgsvcGstCtrlHandleSessionOpen(&ctxHost);
337	break;
338
339	case HOST_SESSION_CLOSE:
340	rc = vgsvcGstCtrlHandleSessionClose(&ctxHost);
341	break;
342
343	default:
344	{
345	/*
346	* Protocol v1 did not have support for (dedicated)
347	* guest sessions, so all actions need to be performed
348	* under behalf of VBoxService's main executable.
349	*
350	* The global session object then acts as a host for all
351	* started guest processes which bring all their
352	* credentials with them with the actual guest process
353	* execution call.
354	*/
355	if (ctxHost.uProtocol == 1)
356	rc = VGSvcGstCtrlSessionHandler(&g_Session, uMsg, &ctxHost, pvScratchBuf, cbScratchBuf, pfShutdown);
357	else
358	{
359	/*
360	* ... on newer protocols handling all other commands is
361	* up to the guest session fork of VBoxService, so just
362	* skip all not wanted messages here.
363	*/
364	rc = VbglR3GuestCtrlMsgSkip(g_uControlSvcClientID);
365	VGSvcVerbose(3, "Skipping uMsg=%RU32, cParms=%RU32, rc=%Rrc\n", uMsg, cParms, rc);
366	}
367	break;
368	}
369	}
370	}
371
372	/* Do we need to shutdown? */
373	if ( *pfShutdown
374	\|\| (RT_SUCCESS(rc) && uMsg == HOST_CANCEL_PENDING_WAITS))
375	{
376	break;
377	}
378
379	/* Let's sleep for a bit and let others run ... */
380	RTThreadYield();
381	}
382
383	VGSvcVerbose(0, "Guest control service stopped\n");
384
385	/* Delete scratch buffer. */
386	if (pvScratchBuf)
387	RTMemFree(pvScratchBuf);
388
389	VGSvcVerbose(0, "Guest control worker returned with rc=%Rrc\n", rc);
390	return rc;
391	}
392
393
394	static int vgsvcGstCtrlHandleSessionOpen(PVBGLR3GUESTCTRLCMDCTX pHostCtx)
395	{
396	AssertPtrReturn(pHostCtx, VERR_INVALID_POINTER);
397
398	VBOXSERVICECTRLSESSIONSTARTUPINFO ssInfo = { 0 };
399	int rc = VbglR3GuestCtrlSessionGetOpen(pHostCtx,
400	&ssInfo.uProtocol,
401	ssInfo.szUser, sizeof(ssInfo.szUser),
402	ssInfo.szPassword, sizeof(ssInfo.szPassword),
403	ssInfo.szDomain, sizeof(ssInfo.szDomain),
404	&ssInfo.fFlags, &ssInfo.uSessionID);
405	if (RT_SUCCESS(rc))
406	{
407	/* The session open call has the protocol version the host
408	* wants to use. So update the current protocol version with the one the
409	* host wants to use in subsequent calls. */
410	pHostCtx->uProtocol = ssInfo.uProtocol;
411	VGSvcVerbose(3, "Client ID=%RU32 now is using protocol %RU32\n", pHostCtx->uClientID, pHostCtx->uProtocol);
412
413	rc = VGSvcGstCtrlSessionThreadCreate(&g_lstControlSessionThreads, &ssInfo, NULL /* ppSessionThread */);
414	}
415
416	if (RT_FAILURE(rc))
417	{
418	/* Report back on failure. On success this will be done
419	* by the forked session thread. */
420	int rc2 = VbglR3GuestCtrlSessionNotify(pHostCtx, GUEST_SESSION_NOTIFYTYPE_ERROR, rc /* uint32_t vs. int */);
421	if (RT_FAILURE(rc2))
422	VGSvcError("Reporting session error status on open failed with rc=%Rrc\n", rc2);
423	}
424
425	VGSvcVerbose(3, "Opening a new guest session returned rc=%Rrc\n", rc);
426	return rc;
427	}
428
429
430	static int vgsvcGstCtrlHandleSessionClose(PVBGLR3GUESTCTRLCMDCTX pHostCtx)
431	{
432	AssertPtrReturn(pHostCtx, VERR_INVALID_POINTER);
433
434	uint32_t uSessionID;
435	uint32_t fFlags;
436	int rc = VbglR3GuestCtrlSessionGetClose(pHostCtx, &fFlags, &uSessionID);
437	if (RT_SUCCESS(rc))
438	{
439	rc = VERR_NOT_FOUND;
440
441	PVBOXSERVICECTRLSESSIONTHREAD pThread;
442	RTListForEach(&g_lstControlSessionThreads, pThread, VBOXSERVICECTRLSESSIONTHREAD, Node)
443	{
444	if (pThread->StartupInfo.uSessionID == uSessionID)
445	{
446	rc = VGSvcGstCtrlSessionThreadDestroy(pThread, fFlags);
447	break;
448	}
449	}
450	#if 0
451	if (RT_FAILURE(rc))
452	{
453	/* Report back on failure. On success this will be done
454	* by the forked session thread. */
455	int rc2 = VbglR3GuestCtrlSessionNotify(pHostCtx,
456	GUEST_SESSION_NOTIFYTYPE_ERROR, rc);
457	if (RT_FAILURE(rc2))
458	{
459	VGSvcError("Reporting session error status on close failed with rc=%Rrc\n", rc2);
460	if (RT_SUCCESS(rc))
461	rc = rc2;
462	}
463	}
464	#endif
465	VGSvcVerbose(2, "Closing guest session %RU32 returned rc=%Rrc\n", uSessionID, rc);
466	}
467	else
468	VGSvcError("Closing guest session %RU32 failed with rc=%Rrc\n", uSessionID, rc);
469	return rc;
470	}
471
472
473	/**
474	* @interface_method_impl{VBOXSERVICE,pfnStop}
475	*/
476	static DECLCALLBACK(void) vgsvcGstCtrlStop(void)
477	{
478	VGSvcVerbose(3, "Stopping ...\n");
479
480	/** @todo Later, figure what to do if we're in RTProcWait(). It's a very
481	* annoying call since doesn't support timeouts in the posix world. */
482	if (g_hControlEvent != NIL_RTSEMEVENTMULTI)
483	RTSemEventMultiSignal(g_hControlEvent);
484
485	/*
486	* Ask the host service to cancel all pending requests for the main
487	* control thread so that we can shutdown properly here.
488	*/
489	if (g_uControlSvcClientID)
490	{
491	VGSvcVerbose(3, "Cancelling pending waits (client ID=%u) ...\n",
492	g_uControlSvcClientID);
493
494	int rc = VbglR3GuestCtrlCancelPendingWaits(g_uControlSvcClientID);
495	if (RT_FAILURE(rc))
496	VGSvcError("Cancelling pending waits failed; rc=%Rrc\n", rc);
497	}
498	}
499
500
501	/**
502	* Destroys all guest process threads which are still active.
503	*/
504	static void vgsvcGstCtrlShutdown(void)
505	{
506	VGSvcVerbose(2, "Shutting down ...\n");
507
508	int rc2 = VGSvcGstCtrlSessionThreadDestroyAll(&g_lstControlSessionThreads, 0 /* Flags */);
509	if (RT_FAILURE(rc2))
510	VGSvcError("Closing session threads failed with rc=%Rrc\n", rc2);
511
512	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
513	if (RT_FAILURE(rc2))
514	VGSvcError("Closing session failed with rc=%Rrc\n", rc2);
515
516	VGSvcVerbose(2, "Shutting down complete\n");
517	}
518
519
520	/**
521	* @interface_method_impl{VBOXSERVICE,pfnTerm}
522	*/
523	static DECLCALLBACK(void) vgsvcGstCtrlTerm(void)
524	{
525	VGSvcVerbose(3, "Terminating ...\n");
526
527	vgsvcGstCtrlShutdown();
528
529	VGSvcVerbose(3, "Disconnecting client ID=%u ...\n", g_uControlSvcClientID);
530	VbglR3GuestCtrlDisconnect(g_uControlSvcClientID);
531	g_uControlSvcClientID = 0;
532
533	if (g_hControlEvent != NIL_RTSEMEVENTMULTI)
534	{
535	RTSemEventMultiDestroy(g_hControlEvent);
536	g_hControlEvent = NIL_RTSEMEVENTMULTI;
537	}
538	}
539
540
541	/**
542	* The 'vminfo' service description.
543	*/
544	VBOXSERVICE g_Control =
545	{
546	/* pszName. */
547	"control",
548	/* pszDescription. */
549	"Host-driven Guest Control",
550	/* pszUsage. */
551	#ifdef DEBUG
552	" [--control-dump-stderr] [--control-dump-stdout]\n"
553	#endif
554	" [--control-interval <ms>]"
555	,
556	/* pszOptions. */
557	#ifdef DEBUG
558	" --control-dump-stderr Dumps all guest proccesses stderr data to the\n"
559	" temporary directory.\n"
560	" --control-dump-stdout Dumps all guest proccesses stdout data to the\n"
561	" temporary directory.\n"
562	#endif
563	" --control-interval Specifies the interval at which to check for\n"
564	" new control commands. The default is 1000 ms.\n"
565	,
566	/* methods */
567	vgsvcGstCtrlPreInit,
568	vgsvcGstCtrlOption,
569	vgsvcGstCtrlInit,
570	vgsvcGstCtrlWorker,
571	vgsvcGstCtrlStop,
572	vgsvcGstCtrlTerm
573	};
574

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source: vbox/trunk/src/VBox/Additions/common/VBoxService/VBoxServiceControl.cpp@ 66891

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