VBoxServiceControl.cpp@ 60641

Last change on this file since 60641 was 58052, checked in by vboxsync, 9 years ago
VBoxService: More service introduction pages. A few more cleanups.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
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1	/* $Id: VBoxServiceControl.cpp 58052 2015-10-06 13:45:20Z vboxsync $ */
2	/** @file
3	* VBoxServiceControl - Host-driven Guest Control.
4	*/
5
6	/*
7	* Copyright (C) 2012-2015 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	/** How many started guest processes are kept into memory for supplying
81	* information to the host. Default is 256 processes. If 0 is specified,
82	* the maximum number of processes is unlimited. */
83	static uint32_t g_uControlProcsMaxKept = 256;
84	/** List of guest control session threads (VBOXSERVICECTRLSESSIONTHREAD).
85	* A guest session thread represents a forked guest session process
86	* of VBoxService. */
87	RTLISTANCHOR g_lstControlSessionThreads;
88	/** The local session object used for handling all session-related stuff.
89	* When using the legacy guest control protocol (< 2), this session runs
90	* under behalf of the VBoxService main process. On newer protocol versions
91	* each session is a forked version of VBoxService using the appropriate
92	* user credentials for opening a guest session. These forked sessions then
93	* are kept in VBOXSERVICECTRLSESSIONTHREAD structures. */
94	VBOXSERVICECTRLSESSION g_Session;
95
96
97	/*********************************************************************************************************************************
98	* Internal Functions *
99	*********************************************************************************************************************************/
100	static int vgsvcGstCtrlHandleSessionOpen(PVBGLR3GUESTCTRLCMDCTX pHostCtx);
101	static int vgsvcGstCtrlHandleSessionClose(PVBGLR3GUESTCTRLCMDCTX pHostCtx);
102	static void vgsvcGstCtrlShutdown(void);
103
104
105	/**
106	* @interface_method_impl{VBOXSERVICE,pfnPreInit}
107	*/
108	static DECLCALLBACK(int) vgsvcGstCtrlPreInit(void)
109	{
110	int rc;
111	#ifdef VBOX_WITH_GUEST_PROPS
112	/*
113	* Read the service options from the VM's guest properties.
114	* Note that these options can be overridden by the command line options later.
115	*/
116	uint32_t uGuestPropSvcClientID;
117	rc = VbglR3GuestPropConnect(&uGuestPropSvcClientID);
118	if (RT_FAILURE(rc))
119	{
120	if (rc == VERR_HGCM_SERVICE_NOT_FOUND) /* Host service is not available. */
121	{
122	VGSvcVerbose(0, "Guest property service is not available, skipping\n");
123	rc = VINF_SUCCESS;
124	}
125	else
126	VGSvcError("Failed to connect to the guest property service, rc=%Rrc\n", rc);
127	}
128	else
129	VbglR3GuestPropDisconnect(uGuestPropSvcClientID);
130
131	if (rc == VERR_NOT_FOUND) /* If a value is not found, don't be sad! */
132	rc = VINF_SUCCESS;
133	#else
134	/* Nothing to do here yet. */
135	rc = VINF_SUCCESS;
136	#endif
137
138	if (RT_SUCCESS(rc))
139	{
140	/* Init session object. */
141	rc = VGSvcGstCtrlSessionInit(&g_Session, 0 /* Flags */);
142	}
143
144	return rc;
145	}
146
147
148	/**
149	* @interface_method_impl{VBOXSERVICE,pfnOption}
150	*/
151	static DECLCALLBACK(int) vgsvcGstCtrlOption(const char ppszShort, int argc, char argv, int *pi)
152	{
153	int rc = -1;
154	if (ppszShort)
155	/* no short options */;
156	else if (!strcmp(argv[*pi], "--control-interval"))
157	rc = VGSvcArgUInt32(argc, argv, "", pi,
158	&g_msControlInterval, 1, UINT32_MAX - 1);
159	#ifdef DEBUG
160	else if (!strcmp(argv[*pi], "--control-dump-stdout"))
161	{
162	g_Session.fFlags \|= VBOXSERVICECTRLSESSION_FLAG_DUMPSTDOUT;
163	rc = 0; /* Flag this command as parsed. */
164	}
165	else if (!strcmp(argv[*pi], "--control-dump-stderr"))
166	{
167	g_Session.fFlags \|= VBOXSERVICECTRLSESSION_FLAG_DUMPSTDERR;
168	rc = 0; /* Flag this command as parsed. */
169	}
170	#endif
171	return rc;
172	}
173
174
175	/**
176	* @interface_method_impl{VBOXSERVICE,pfnInit}
177	*/
178	static DECLCALLBACK(int) vgsvcGstCtrlInit(void)
179	{
180	/*
181	* If not specified, find the right interval default.
182	* Then create the event sem to block on.
183	*/
184	if (!g_msControlInterval)
185	g_msControlInterval = 1000;
186
187	int rc = RTSemEventMultiCreate(&g_hControlEvent);
188	AssertRCReturn(rc, rc);
189
190	VbglR3GetSessionId(&g_idControlSession);
191	/* The status code is ignored as this information is not available with VBox < 3.2.10. */
192
193	if (RT_SUCCESS(rc))
194	rc = VbglR3GuestCtrlConnect(&g_uControlSvcClientID);
195	if (RT_SUCCESS(rc))
196	{
197	VGSvcVerbose(3, "Guest control service client ID=%RU32\n", g_uControlSvcClientID);
198
199	/* Init session thread list. */
200	RTListInit(&g_lstControlSessionThreads);
201	}
202	else
203	{
204	/* If the service was not found, we disable this service without
205	causing VBoxService to fail. */
206	if (rc == VERR_HGCM_SERVICE_NOT_FOUND) /* Host service is not available. */
207	{
208	VGSvcVerbose(0, "Guest control service is not available\n");
209	rc = VERR_SERVICE_DISABLED;
210	}
211	else
212	VGSvcError("Failed to connect to the guest control service! Error: %Rrc\n", rc);
213	RTSemEventMultiDestroy(g_hControlEvent);
214	g_hControlEvent = NIL_RTSEMEVENTMULTI;
215	}
216	return rc;
217	}
218
219
220	/**
221	* @interface_method_impl{VBOXSERVICE,pfnWorker}
222	*/
223	static DECLCALLBACK(int) vgsvcGstCtrlWorker(bool volatile *pfShutdown)
224	{
225	/*
226	* Tell the control thread that it can continue
227	* spawning services.
228	*/
229	RTThreadUserSignal(RTThreadSelf());
230	Assert(g_uControlSvcClientID > 0);
231
232	int rc = VINF_SUCCESS;
233
234	/* Allocate a scratch buffer for commands which also send
235	* payload data with them. */
236	uint32_t cbScratchBuf = _64K; /** @todo Make buffer size configurable via guest properties/argv! */
237	AssertReturn(RT_IS_POWER_OF_TWO(cbScratchBuf), VERR_INVALID_PARAMETER);
238	uint8_t pvScratchBuf = (uint8_t)RTMemAlloc(cbScratchBuf);
239	AssertReturn(pvScratchBuf, VERR_NO_MEMORY);
240
241	VBGLR3GUESTCTRLCMDCTX ctxHost = { g_uControlSvcClientID };
242	/* Set default protocol version to 1. */
243	ctxHost.uProtocol = 1;
244
245	int cRetrievalFailed = 0; /* Number of failed message retrievals in a row. */
246	for (;;)
247	{
248	VGSvcVerbose(3, "Waiting for host msg ...\n");
249	uint32_t uMsg = 0;
250	uint32_t cParms = 0;
251	rc = VbglR3GuestCtrlMsgWaitFor(g_uControlSvcClientID, &uMsg, &cParms);
252	if (rc == VERR_TOO_MUCH_DATA)
253	{
254	#ifdef DEBUG
255	VGSvcVerbose(4, "Message requires %ld parameters, but only 2 supplied -- retrying request (no error!)...\n",
256	cParms);
257	#endif
258	rc = VINF_SUCCESS; /* Try to get "real" message in next block below. */
259	}
260	else if (RT_FAILURE(rc))
261	{
262	/* Note: VERR_GEN_IO_FAILURE seems to be normal if ran into timeout. */
263	VGSvcError("Getting host message failed with %Rrc\n", rc);
264
265	/* Check for VM session change. */
266	uint64_t idNewSession = g_idControlSession;
267	int rc2 = VbglR3GetSessionId(&idNewSession);
268	if ( RT_SUCCESS(rc2)
269	&& (idNewSession != g_idControlSession))
270	{
271	VGSvcVerbose(1, "The VM session ID changed\n");
272	g_idControlSession = idNewSession;
273
274	/* Close all opened guest sessions -- all context IDs, sessions etc.
275	* are now invalid. */
276	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
277	AssertRC(rc2);
278
279	/* Do a reconnect. */
280	VGSvcVerbose(1, "Reconnecting to HGCM service ...\n");
281	rc2 = VbglR3GuestCtrlConnect(&g_uControlSvcClientID);
282	if (RT_SUCCESS(rc2))
283	{
284	VGSvcVerbose(3, "Guest control service client ID=%RU32\n", g_uControlSvcClientID);
285	cRetrievalFailed = 0;
286	continue; /* Skip waiting. */
287	}
288	else
289	{
290	VGSvcError("Unable to re-connect to HGCM service, rc=%Rrc, bailing out\n", rc);
291	break;
292	}
293	}
294
295	if (++cRetrievalFailed > 16) /** @todo Make this configurable? */
296	{
297	VGSvcError("Too many failed attempts in a row to get next message, bailing out\n");
298	break;
299	}
300
301	RTThreadSleep(1000); /* Wait a bit before retrying. */
302	}
303
304	if (RT_SUCCESS(rc))
305	{
306	VGSvcVerbose(4, "Msg=%RU32 (%RU32 parms) retrieved\n", uMsg, cParms);
307	cRetrievalFailed = 0; /* Reset failed retrieval count. */
308
309	/* Set number of parameters for current host context. */
310	ctxHost.uNumParms = cParms;
311
312	/* Check for VM session change. */
313	uint64_t idNewSession = g_idControlSession;
314	int rc2 = VbglR3GetSessionId(&idNewSession);
315	if ( RT_SUCCESS(rc2)
316	&& (idNewSession != g_idControlSession))
317	{
318	VGSvcVerbose(1, "The VM session ID changed\n");
319	g_idControlSession = idNewSession;
320
321	/* Close all opened guest sessions -- all context IDs, sessions etc.
322	* are now invalid. */
323	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
324	AssertRC(rc2);
325	}
326
327	switch (uMsg)
328	{
329	case HOST_CANCEL_PENDING_WAITS:
330	VGSvcVerbose(1, "We were asked to quit ...\n");
331	break;
332
333	case HOST_SESSION_CREATE:
334	rc = vgsvcGstCtrlHandleSessionOpen(&ctxHost);
335	break;
336
337	case HOST_SESSION_CLOSE:
338	rc = vgsvcGstCtrlHandleSessionClose(&ctxHost);
339	break;
340
341	default:
342	{
343	/*
344	* Protocol v1 did not have support for (dedicated)
345	* guest sessions, so all actions need to be performed
346	* under behalf of VBoxService's main executable.
347	*
348	* The global session object then acts as a host for all
349	* started guest processes which bring all their
350	* credentials with them with the actual guest process
351	* execution call.
352	*/
353	if (ctxHost.uProtocol == 1)
354	rc = VGSvcGstCtrlSessionHandler(&g_Session, uMsg, &ctxHost, pvScratchBuf, cbScratchBuf, pfShutdown);
355	else
356	{
357	/*
358	* ... on newer protocols handling all other commands is
359	* up to the guest session fork of VBoxService, so just
360	* skip all not wanted messages here.
361	*/
362	rc = VbglR3GuestCtrlMsgSkip(g_uControlSvcClientID);
363	VGSvcVerbose(3, "Skipping uMsg=%RU32, cParms=%RU32, rc=%Rrc\n", uMsg, cParms, rc);
364	}
365	break;
366	}
367	}
368	}
369
370	/* Do we need to shutdown? */
371	if ( *pfShutdown
372	\|\| (RT_SUCCESS(rc) && uMsg == HOST_CANCEL_PENDING_WAITS))
373	{
374	break;
375	}
376
377	/* Let's sleep for a bit and let others run ... */
378	RTThreadYield();
379	}
380
381	VGSvcVerbose(0, "Guest control service stopped\n");
382
383	/* Delete scratch buffer. */
384	if (pvScratchBuf)
385	RTMemFree(pvScratchBuf);
386
387	VGSvcVerbose(0, "Guest control worker returned with rc=%Rrc\n", rc);
388	return rc;
389	}
390
391
392	static int vgsvcGstCtrlHandleSessionOpen(PVBGLR3GUESTCTRLCMDCTX pHostCtx)
393	{
394	AssertPtrReturn(pHostCtx, VERR_INVALID_POINTER);
395
396	VBOXSERVICECTRLSESSIONSTARTUPINFO ssInfo = { 0 };
397	int rc = VbglR3GuestCtrlSessionGetOpen(pHostCtx,
398	&ssInfo.uProtocol,
399	ssInfo.szUser, sizeof(ssInfo.szUser),
400	ssInfo.szPassword, sizeof(ssInfo.szPassword),
401	ssInfo.szDomain, sizeof(ssInfo.szDomain),
402	&ssInfo.fFlags, &ssInfo.uSessionID);
403	if (RT_SUCCESS(rc))
404	{
405	/* The session open call has the protocol version the host
406	* wants to use. So update the current protocol version with the one the
407	* host wants to use in subsequent calls. */
408	pHostCtx->uProtocol = ssInfo.uProtocol;
409	VGSvcVerbose(3, "Client ID=%RU32 now is using protocol %RU32\n", pHostCtx->uClientID, pHostCtx->uProtocol);
410
411	rc = VGSvcGstCtrlSessionThreadCreate(&g_lstControlSessionThreads, &ssInfo, NULL /* ppSessionThread */);
412	}
413
414	if (RT_FAILURE(rc))
415	{
416	/* Report back on failure. On success this will be done
417	* by the forked session thread. */
418	int rc2 = VbglR3GuestCtrlSessionNotify(pHostCtx, GUEST_SESSION_NOTIFYTYPE_ERROR, rc /* uint32_t vs. int */);
419	if (RT_FAILURE(rc2))
420	VGSvcError("Reporting session error status on open failed with rc=%Rrc\n", rc2);
421	}
422
423	VGSvcVerbose(3, "Opening a new guest session returned rc=%Rrc\n", rc);
424	return rc;
425	}
426
427
428	static int vgsvcGstCtrlHandleSessionClose(PVBGLR3GUESTCTRLCMDCTX pHostCtx)
429	{
430	AssertPtrReturn(pHostCtx, VERR_INVALID_POINTER);
431
432	uint32_t uSessionID;
433	uint32_t fFlags;
434	int rc = VbglR3GuestCtrlSessionGetClose(pHostCtx, &fFlags, &uSessionID);
435	if (RT_SUCCESS(rc))
436	{
437	rc = VERR_NOT_FOUND;
438
439	PVBOXSERVICECTRLSESSIONTHREAD pThread;
440	RTListForEach(&g_lstControlSessionThreads, pThread, VBOXSERVICECTRLSESSIONTHREAD, Node)
441	{
442	if (pThread->StartupInfo.uSessionID == uSessionID)
443	{
444	rc = VGSvcGstCtrlSessionThreadDestroy(pThread, fFlags);
445	break;
446	}
447	}
448	#if 0
449	if (RT_FAILURE(rc))
450	{
451	/* Report back on failure. On success this will be done
452	* by the forked session thread. */
453	int rc2 = VbglR3GuestCtrlSessionNotify(pHostCtx,
454	GUEST_SESSION_NOTIFYTYPE_ERROR, rc);
455	if (RT_FAILURE(rc2))
456	{
457	VGSvcError("Reporting session error status on close failed with rc=%Rrc\n", rc2);
458	if (RT_SUCCESS(rc))
459	rc = rc2;
460	}
461	}
462	#endif
463	VGSvcVerbose(2, "Closing guest session %RU32 returned rc=%Rrc\n", uSessionID, rc);
464	}
465	else
466	VGSvcError("Closing guest session %RU32 failed with rc=%Rrc\n", uSessionID, rc);
467	return rc;
468	}
469
470
471	/**
472	* @interface_method_impl{VBOXSERVICE,pfnStop}
473	*/
474	static DECLCALLBACK(void) vgsvcGstCtrlStop(void)
475	{
476	VGSvcVerbose(3, "Stopping ...\n");
477
478	/** @todo Later, figure what to do if we're in RTProcWait(). It's a very
479	* annoying call since doesn't support timeouts in the posix world. */
480	if (g_hControlEvent != NIL_RTSEMEVENTMULTI)
481	RTSemEventMultiSignal(g_hControlEvent);
482
483	/*
484	* Ask the host service to cancel all pending requests for the main
485	* control thread so that we can shutdown properly here.
486	*/
487	if (g_uControlSvcClientID)
488	{
489	VGSvcVerbose(3, "Cancelling pending waits (client ID=%u) ...\n",
490	g_uControlSvcClientID);
491
492	int rc = VbglR3GuestCtrlCancelPendingWaits(g_uControlSvcClientID);
493	if (RT_FAILURE(rc))
494	VGSvcError("Cancelling pending waits failed; rc=%Rrc\n", rc);
495	}
496	}
497
498
499	/**
500	* Destroys all guest process threads which are still active.
501	*/
502	static void vgsvcGstCtrlShutdown(void)
503	{
504	VGSvcVerbose(2, "Shutting down ...\n");
505
506	int rc2 = VGSvcGstCtrlSessionThreadDestroyAll(&g_lstControlSessionThreads, 0 /* Flags */);
507	if (RT_FAILURE(rc2))
508	VGSvcError("Closing session threads failed with rc=%Rrc\n", rc2);
509
510	rc2 = VGSvcGstCtrlSessionClose(&g_Session);
511	if (RT_FAILURE(rc2))
512	VGSvcError("Closing session failed with rc=%Rrc\n", rc2);
513
514	VGSvcVerbose(2, "Shutting down complete\n");
515	}
516
517
518	/**
519	* @interface_method_impl{VBOXSERVICE,pfnTerm}
520	*/
521	static DECLCALLBACK(void) vgsvcGstCtrlTerm(void)
522	{
523	VGSvcVerbose(3, "Terminating ...\n");
524
525	vgsvcGstCtrlShutdown();
526
527	VGSvcVerbose(3, "Disconnecting client ID=%u ...\n", g_uControlSvcClientID);
528	VbglR3GuestCtrlDisconnect(g_uControlSvcClientID);
529	g_uControlSvcClientID = 0;
530
531	if (g_hControlEvent != NIL_RTSEMEVENTMULTI)
532	{
533	RTSemEventMultiDestroy(g_hControlEvent);
534	g_hControlEvent = NIL_RTSEMEVENTMULTI;
535	}
536	}
537
538
539	/**
540	* The 'vminfo' service description.
541	*/
542	VBOXSERVICE g_Control =
543	{
544	/* pszName. */
545	"control",
546	/* pszDescription. */
547	"Host-driven Guest Control",
548	/* pszUsage. */
549	#ifdef DEBUG
550	" [--control-dump-stderr] [--control-dump-stdout]\n"
551	#endif
552	" [--control-interval <ms>]"
553	,
554	/* pszOptions. */
555	#ifdef DEBUG
556	" --control-dump-stderr Dumps all guest proccesses stderr data to the\n"
557	" temporary directory.\n"
558	" --control-dump-stdout Dumps all guest proccesses stdout data to the\n"
559	" temporary directory.\n"
560	#endif
561	" --control-interval Specifies the interval at which to check for\n"
562	" new control commands. The default is 1000 ms.\n"
563	,
564	/* methods */
565	vgsvcGstCtrlPreInit,
566	vgsvcGstCtrlOption,
567	vgsvcGstCtrlInit,
568	vgsvcGstCtrlWorker,
569	vgsvcGstCtrlStop,
570	vgsvcGstCtrlTerm
571	};
572

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source: vbox/trunk/src/VBox/Additions/common/VBoxService/VBoxServiceControl.cpp@ 60641

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