process-creation-posix.cpp@ 39032

Last change on this file since 39032 was 39032, checked in by vboxsync, 13 years ago
IPRT: Fixed unused variable warnings.
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1	/* $Id: process-creation-posix.cpp 39032 2011-10-19 11:08:50Z vboxsync $ */
2	/** @file
3	* IPRT - Process Creation, POSIX.
4	*/
5
6	/*
7	* Copyright (C) 2006-2010 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	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*******************************************************************************
29	* Header Files *
30	*******************************************************************************/
31	#define LOG_GROUP RTLOGGROUP_PROCESS
32	#include <unistd.h>
33	#include <stdlib.h>
34	#include <errno.h>
35	#include <sys/types.h>
36	#include <sys/stat.h>
37	#include <sys/wait.h>
38	#include <fcntl.h>
39	#include <signal.h>
40	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_SOLARIS)
41	# include <crypt.h>
42	# include <pwd.h>
43	# include <shadow.h>
44	#endif
45	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2)
46	/* While Solaris has posix_spawn() of course we don't want to use it as
47	* we need to have the child in a different process contract, no matter
48	* whether it is started detached or not. */
49	# define HAVE_POSIX_SPAWN 1
50	#endif
51	#ifdef HAVE_POSIX_SPAWN
52	# include <spawn.h>
53	#endif
54	#ifdef RT_OS_DARWIN
55	# include <mach-o/dyld.h>
56	#endif
57	#ifdef RT_OS_SOLARIS
58	# include <limits.h>
59	# include <sys/ctfs.h>
60	# include <sys/contract/process.h>
61	# include <libcontract.h>
62	#endif
63
64	#include <iprt/process.h>
65	#include "internal/iprt.h"
66
67	#include <iprt/assert.h>
68	#include <iprt/env.h>
69	#include <iprt/err.h>
70	#include <iprt/file.h>
71	#include <iprt/pipe.h>
72	#include <iprt/socket.h>
73	#include <iprt/string.h>
74	#include <iprt/mem.h>
75	#include "internal/process.h"
76
77
78	/**
79	* Check the credentials and return the gid/uid of user.
80	*
81	* @param pszUser username
82	* @param pszPasswd password
83	* @param gid where to store the GID of the user
84	* @param uid where to store the UID of the user
85	* @returns IPRT status code
86	*/
87	static int rtCheckCredentials(const char pszUser, const char pszPasswd, gid_t gid, uid_t uid)
88	{
89	#if defined(RT_OS_LINUX)
90	struct passwd *pw;
91
92	pw = getpwnam(pszUser);
93	if (!pw)
94	return VERR_PERMISSION_DENIED;
95
96	if (!pszPasswd)
97	pszPasswd = "";
98
99	struct spwd *spwd;
100	/* works only if /etc/shadow is accessible */
101	spwd = getspnam(pszUser);
102	if (spwd)
103	pw->pw_passwd = spwd->sp_pwdp;
104
105	/* be reentrant */
106	struct crypt_data data = (struct crypt_data)RTMemTmpAllocZ(sizeof(*data));
107	char *pszEncPasswd = crypt_r(pszPasswd, pw->pw_passwd, data);
108	int fCorrect = !strcmp(pszEncPasswd, pw->pw_passwd);
109	RTMemTmpFree(data);
110	if (!fCorrect)
111	return VERR_PERMISSION_DENIED;
112
113	*gid = pw->pw_gid;
114	*uid = pw->pw_uid;
115	return VINF_SUCCESS;
116
117	#elif defined(RT_OS_SOLARIS)
118	struct passwd *ppw, pw;
119	char szBuf[1024];
120
121	if (getpwnam_r(pszUser, &pw, szBuf, sizeof(szBuf), &ppw) != 0 \|\| ppw == NULL)
122	return VERR_PERMISSION_DENIED;
123
124	if (!pszPasswd)
125	pszPasswd = "";
126
127	struct spwd spwd;
128	char szPwdBuf[1024];
129	/* works only if /etc/shadow is accessible */
130	if (getspnam_r(pszUser, &spwd, szPwdBuf, sizeof(szPwdBuf)) != NULL)
131	ppw->pw_passwd = spwd.sp_pwdp;
132
133	char *pszEncPasswd = crypt(pszPasswd, ppw->pw_passwd);
134	if (strcmp(pszEncPasswd, ppw->pw_passwd))
135	return VERR_PERMISSION_DENIED;
136
137	*gid = ppw->pw_gid;
138	*uid = ppw->pw_uid;
139	return VINF_SUCCESS;
140
141	#else
142	return VERR_PERMISSION_DENIED;
143	#endif
144	}
145
146
147	#ifdef RT_OS_SOLARIS
148	/** @todo the error reporting of the Solaris process contract code could be
149	* a lot better, but essentially it is not meant to run into errors after
150	* the debugging phase. */
151	static int rtSolarisContractPreFork(void)
152	{
153	int templateFd = open64(CTFS_ROOT "/process/template", O_RDWR);
154	if (templateFd < 0)
155	return -1;
156
157	/* Set template parameters and event sets. */
158	if (ct_pr_tmpl_set_param(templateFd, CT_PR_PGRPONLY))
159	{
160	close(templateFd);
161	return -1;
162	}
163	if (ct_pr_tmpl_set_fatal(templateFd, CT_PR_EV_HWERR))
164	{
165	close(templateFd);
166	return -1;
167	}
168	if (ct_tmpl_set_critical(templateFd, 0))
169	{
170	close(templateFd);
171	return -1;
172	}
173	if (ct_tmpl_set_informative(templateFd, CT_PR_EV_HWERR))
174	{
175	close(templateFd);
176	return -1;
177	}
178
179	/* Make this the active template for the process. */
180	if (ct_tmpl_activate(templateFd))
181	{
182	close(templateFd);
183	return -1;
184	}
185
186	return templateFd;
187	}
188
189	static void rtSolarisContractPostForkChild(int templateFd)
190	{
191	if (templateFd == -1)
192	return;
193
194	/* Clear the active template. */
195	ct_tmpl_clear(templateFd);
196	close(templateFd);
197	}
198
199	static void rtSolarisContractPostForkParent(int templateFd, pid_t pid)
200	{
201	if (templateFd == -1)
202	return;
203
204	/* Clear the active template. */
205	int cleared = ct_tmpl_clear(templateFd);
206	close(templateFd);
207
208	/* If the clearing failed or the fork failed there's nothing more to do. */
209	if (cleared \|\| pid <= 0)
210	return;
211
212	/* Look up the contract which was created by this thread. */
213	int statFd = open64(CTFS_ROOT "/process/latest", O_RDONLY);
214	if (statFd == -1)
215	return;
216	ct_stathdl_t statHdl;
217	if (ct_status_read(statFd, CTD_COMMON, &statHdl))
218	{
219	close(statFd);
220	return;
221	}
222	ctid_t ctId = ct_status_get_id(statHdl);
223	ct_status_free(statHdl);
224	close(statFd);
225	if (ctId < 0)
226	return;
227
228	/* Abandon this contract we just created. */
229	char ctlPath[PATH_MAX];
230	size_t len = snprintf(ctlPath, sizeof(ctlPath),
231	CTFS_ROOT "/process/%d/ctl", ctId);
232	if (len >= sizeof(ctlPath))
233	return;
234	int ctlFd = open64(ctlPath, O_WRONLY);
235	if (statFd == -1)
236	return;
237	if (ct_ctl_abandon(ctlFd) < 0)
238	{
239	close(ctlFd);
240	return;
241	}
242	close(ctlFd);
243	}
244
245	#endif /* RT_OS_SOLARIS */
246
247
248	RTR3DECL(int) RTProcCreate(const char pszExec, const char const *papszArgs, RTENV Env, unsigned fFlags, PRTPROCESS pProcess)
249	{
250	return RTProcCreateEx(pszExec, papszArgs, Env, fFlags,
251	NULL, NULL, NULL, /* standard handles */
252	NULL /pszAsUser/, NULL /* pszPassword*/,
253	pProcess);
254	}
255
256
257	RTR3DECL(int) RTProcCreateEx(const char pszExec, const char const *papszArgs, RTENV hEnv, uint32_t fFlags,
258	PCRTHANDLE phStdIn, PCRTHANDLE phStdOut, PCRTHANDLE phStdErr, const char *pszAsUser,
259	const char *pszPassword, PRTPROCESS phProcess)
260	{
261	int rc;
262
263	/*
264	* Input validation
265	*/
266	AssertPtrReturn(pszExec, VERR_INVALID_POINTER);
267	AssertReturn(*pszExec, VERR_INVALID_PARAMETER);
268	AssertReturn(!(fFlags & ~(RTPROC_FLAGS_DETACHED \| RTPROC_FLAGS_HIDDEN \| RTPROC_FLAGS_SERVICE \| RTPROC_FLAGS_SAME_CONTRACT \| RTPROC_FLAGS_NO_PROFILE)), VERR_INVALID_PARAMETER);
269	AssertReturn(!(fFlags & RTPROC_FLAGS_DETACHED) \|\| !phProcess, VERR_INVALID_PARAMETER);
270	AssertReturn(hEnv != NIL_RTENV, VERR_INVALID_PARAMETER);
271	const char * const *papszEnv = RTEnvGetExecEnvP(hEnv);
272	AssertPtrReturn(papszEnv, VERR_INVALID_HANDLE);
273	AssertPtrReturn(papszArgs, VERR_INVALID_PARAMETER);
274	/** @todo search the PATH (add flag for this). */
275	AssertPtrNullReturn(pszAsUser, VERR_INVALID_POINTER);
276	AssertReturn(!pszAsUser \|\| *pszAsUser, VERR_INVALID_PARAMETER);
277	AssertReturn(!pszPassword \|\| pszAsUser, VERR_INVALID_PARAMETER);
278	AssertPtrNullReturn(pszPassword, VERR_INVALID_POINTER);
279
280	/*
281	* Get the file descriptors for the handles we've been passed.
282	*/
283	PCRTHANDLE paHandles[3] = { phStdIn, phStdOut, phStdErr };
284	int aStdFds[3] = { -1, -1, -1 };
285	for (int i = 0; i < 3; i++)
286	{
287	if (paHandles[i])
288	{
289	AssertPtrReturn(paHandles[i], VERR_INVALID_POINTER);
290	switch (paHandles[i]->enmType)
291	{
292	case RTHANDLETYPE_FILE:
293	aStdFds[i] = paHandles[i]->u.hFile != NIL_RTFILE
294	? (int)RTFileToNative(paHandles[i]->u.hFile)
295	: -2 /* close it */;
296	break;
297
298	case RTHANDLETYPE_PIPE:
299	aStdFds[i] = paHandles[i]->u.hPipe != NIL_RTPIPE
300	? (int)RTPipeToNative(paHandles[i]->u.hPipe)
301	: -2 /* close it */;
302	break;
303
304	case RTHANDLETYPE_SOCKET:
305	aStdFds[i] = paHandles[i]->u.hSocket != NIL_RTSOCKET
306	? (int)RTSocketToNative(paHandles[i]->u.hSocket)
307	: -2 /* close it */;
308	break;
309
310	default:
311	AssertMsgFailedReturn(("%d: %d\n", i, paHandles[i]->enmType), VERR_INVALID_PARAMETER);
312	}
313	/** @todo check the close-on-execness of these handles? */
314	}
315	}
316
317	for (int i = 0; i < 3; i++)
318	if (aStdFds[i] == i)
319	aStdFds[i] = -1;
320
321	for (int i = 0; i < 3; i++)
322	AssertMsgReturn(aStdFds[i] < 0 \|\| aStdFds[i] > i,
323	("%i := %i not possible because we're lazy\n", i, aStdFds[i]),
324	VERR_NOT_SUPPORTED);
325
326	/*
327	* Resolve the user id if specified.
328	*/
329	uid_t uid = ~(uid_t)0;
330	gid_t gid = ~(gid_t)0;
331	if (pszAsUser)
332	{
333	rc = rtCheckCredentials(pszAsUser, pszPassword, &gid, &uid);
334	if (RT_FAILURE(rc))
335	return rc;
336	}
337
338	/*
339	* Check for execute access to the file.
340	*/
341	if (access(pszExec, X_OK))
342	return RTErrConvertFromErrno(errno);
343
344	pid_t pid = -1;
345
346	/*
347	* Take care of detaching the process.
348	*
349	* HACK ALERT! Put the process into a new process group with pgid = pid
350	* to make sure it differs from that of the parent process to ensure that
351	* the IPRT waitpid call doesn't race anyone (read XPCOM) doing group wide
352	* waits. setsid() includes the setpgid() functionality.
353	* 2010-10-11 XPCOM no longer waits for anything, but it cannot hurt.
354	*/
355	#ifndef RT_OS_OS2
356	if (fFlags & RTPROC_FLAGS_DETACHED)
357	{
358	# ifdef RT_OS_SOLARIS
359	int templateFd = -1;
360	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
361	{
362	templateFd = rtSolarisContractPreFork();
363	if (templateFd == -1)
364	return VERR_OPEN_FAILED;
365	}
366	# endif /* RT_OS_SOLARIS */
367	pid = fork();
368	if (!pid)
369	{
370	# ifdef RT_OS_SOLARIS
371	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
372	rtSolarisContractPostForkChild(templateFd);
373	# endif /* RT_OS_SOLARIS */
374	setsid(); /* see comment above */
375
376	pid = -1;
377	/* Child falls through to the actual spawn code below. */
378	}
379	else
380	{
381	#ifdef RT_OS_SOLARIS
382	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
383	rtSolarisContractPostForkParent(templateFd, pid);
384	#endif /* RT_OS_SOLARIS */
385	if (pid > 0)
386	{
387	/* Must wait for the temporary process to avoid a zombie. */
388	int status = 0;
389	pid_t pidChild = 0;
390
391	/* Restart if we get interrupted. */
392	do
393	{
394	pidChild = waitpid(pid, &status, 0);
395	} while ( pidChild == -1
396	&& errno == EINTR);
397
398	/* Assume that something wasn't found. No detailed info. */
399	if (status)
400	return VERR_PROCESS_NOT_FOUND;
401	if (phProcess)
402	*phProcess = 0;
403	return VINF_SUCCESS;
404	}
405	return RTErrConvertFromErrno(errno);
406	}
407	}
408	#endif
409
410	/*
411	* Spawn the child.
412	*
413	* Any spawn code MUST not execute any atexit functions if it is for a
414	* detached process. It would lead to running the atexit functions which
415	* make only sense for the parent. libORBit e.g. gets confused by multiple
416	* execution. Remember, there was only a fork() so far, and until exec()
417	* is successfully run there is nothing which would prevent doing anything
418	* silly with the (duplicated) file descriptors.
419	*/
420	#ifdef HAVE_POSIX_SPAWN
421	/** @todo OS/2: implement DETACHED (BACKGROUND stuff), see VbglR3Daemonize. */
422	if ( uid == ~(uid_t)0
423	&& gid == ~(gid_t)0)
424	{
425	/* Spawn attributes. */
426	posix_spawnattr_t Attr;
427	rc = posix_spawnattr_init(&Attr);
428	if (!rc)
429	{
430	# ifndef RT_OS_OS2 /* We don't need this on OS/2 and I don't recall if it's actually implemented. */
431	rc = posix_spawnattr_setflags(&Attr, POSIX_SPAWN_SETPGROUP);
432	Assert(rc == 0);
433	if (!rc)
434	{
435	rc = posix_spawnattr_setpgroup(&Attr, 0 /* pg == child pid */);
436	Assert(rc == 0);
437	}
438	# endif
439
440	/* File changes. */
441	posix_spawn_file_actions_t FileActions;
442	posix_spawn_file_actions_t *pFileActions = NULL;
443	if (aStdFds[0] != -1 \|\| aStdFds[1] != -1 \|\| aStdFds[2] != -1)
444	{
445	rc = posix_spawn_file_actions_init(&FileActions);
446	if (!rc)
447	{
448	pFileActions = &FileActions;
449	for (int i = 0; i < 3; i++)
450	{
451	int fd = aStdFds[i];
452	if (fd == -2)
453	rc = posix_spawn_file_actions_addclose(&FileActions, i);
454	else if (fd >= 0 && fd != i)
455	{
456	rc = posix_spawn_file_actions_adddup2(&FileActions, fd, i);
457	if (!rc)
458	{
459	for (int j = i + 1; j < 3; j++)
460	if (aStdFds[j] == fd)
461	{
462	fd = -1;
463	break;
464	}
465	if (fd >= 0)
466	rc = posix_spawn_file_actions_addclose(&FileActions, fd);
467	}
468	}
469	if (rc)
470	break;
471	}
472	}
473	}
474
475	if (!rc)
476	rc = posix_spawn(&pid, pszExec, pFileActions, &Attr, (char * const *)papszArgs,
477	(char * const *)papszEnv);
478
479	/* cleanup */
480	int rc2 = posix_spawnattr_destroy(&Attr); Assert(rc2 == 0); NOREF(rc2);
481	if (pFileActions)
482	{
483	rc2 = posix_spawn_file_actions_destroy(pFileActions);
484	Assert(rc2 == 0);
485	}
486
487	/* return on success.*/
488	if (!rc)
489	{
490	/* For a detached process this happens in the temp process, so
491	* it's not worth doing anything as this process must exit. */
492	if (fFlags & RTPROC_FLAGS_DETACHED)
493	_Exit(0);
494	if (phProcess)
495	*phProcess = pid;
496	return VINF_SUCCESS;
497	}
498	}
499	/* For a detached process this happens in the temp process, so
500	* it's not worth doing anything as this process must exit. */
501	if (fFlags & RTPROC_FLAGS_DETACHED)
502	_Exit(124);
503	}
504	else
505	#endif
506	{
507	#ifdef RT_OS_SOLARIS
508	int templateFd = rtSolarisContractPreFork();
509	if (templateFd == -1)
510	return VERR_OPEN_FAILED;
511	#endif /* RT_OS_SOLARIS */
512	pid = fork();
513	if (!pid)
514	{
515	#ifdef RT_OS_SOLARIS
516	rtSolarisContractPostForkChild(templateFd);
517	#endif /* RT_OS_SOLARIS */
518	if (!(fFlags & RTPROC_FLAGS_DETACHED))
519	setpgid(0, 0); /* see comment above */
520
521	/*
522	* Change group and user if requested.
523	*/
524	#if 1 /** @todo This needs more work, see suplib/hardening. */
525	if (gid != ~(gid_t)0)
526	{
527	if (setgid(gid))
528	{
529	if (fFlags & RTPROC_FLAGS_DETACHED)
530	_Exit(126);
531	else
532	exit(126);
533	}
534	}
535
536	if (uid != ~(uid_t)0)
537	{
538	if (setuid(uid))
539	{
540	if (fFlags & RTPROC_FLAGS_DETACHED)
541	_Exit(126);
542	else
543	exit(126);
544	}
545	}
546	#endif
547
548	/*
549	* Apply changes to the standard file descriptor and stuff.
550	*/
551	for (int i = 0; i < 3; i++)
552	{
553	int fd = aStdFds[i];
554	if (fd == -2)
555	close(i);
556	else if (fd >= 0)
557	{
558	int rc2 = dup2(fd, i);
559	if (rc2 != i)
560	{
561	if (fFlags & RTPROC_FLAGS_DETACHED)
562	_Exit(125);
563	else
564	exit(125);
565	}
566	for (int j = i + 1; j < 3; j++)
567	if (aStdFds[j] == fd)
568	{
569	fd = -1;
570	break;
571	}
572	if (fd >= 0)
573	close(fd);
574	}
575	}
576
577	/*
578	* Finally, execute the requested program.
579	*/
580	rc = execve(pszExec, (char * const )papszArgs, (char const *)papszEnv);
581	if (errno == ENOEXEC)
582	{
583	/* This can happen when trying to start a shell script without the magic #!/bin/sh */
584	RTAssertMsg2Weak("Cannot execute this binary format!\n");
585	}
586	else
587	RTAssertMsg2Weak("execve returns %d errno=%d\n", rc, errno);
588	RTAssertReleasePanic();
589	if (fFlags & RTPROC_FLAGS_DETACHED)
590	_Exit(127);
591	else
592	exit(127);
593	}
594	#ifdef RT_OS_SOLARIS
595	rtSolarisContractPostForkParent(templateFd, pid);
596	#endif /* RT_OS_SOLARIS */
597	if (pid > 0)
598	{
599	/* For a detached process this happens in the temp process, so
600	* it's not worth doing anything as this process must exit. */
601	if (fFlags & RTPROC_FLAGS_DETACHED)
602	_Exit(0);
603	if (phProcess)
604	*phProcess = pid;
605	return VINF_SUCCESS;
606	}
607	/* For a detached process this happens in the temp process, so
608	* it's not worth doing anything as this process must exit. */
609	if (fFlags & RTPROC_FLAGS_DETACHED)
610	_Exit(124);
611	return RTErrConvertFromErrno(errno);
612	}
613
614	return VERR_NOT_IMPLEMENTED;
615	}
616
617
618	RTR3DECL(int) RTProcDaemonizeUsingFork(bool fNoChDir, bool fNoClose, const char *pszPidfile)
619	{
620	/*
621	* Fork the child process in a new session and quit the parent.
622	*
623	* - fork once and create a new session (setsid). This will detach us
624	* from the controlling tty meaning that we won't receive the SIGHUP
625	* (or any other signal) sent to that session.
626	* - The SIGHUP signal is ignored because the session/parent may throw
627	* us one before we get to the setsid.
628	* - When the parent exit(0) we will become an orphan and re-parented to
629	* the init process.
630	* - Because of the sometimes unexpected semantics of assigning the
631	* controlling tty automagically when a session leader first opens a tty,
632	* we will fork() once more to get rid of the session leadership role.
633	*/
634
635	/* We start off by opening the pidfile, so that we can fail straight away
636	* if it already exists. */
637	int fdPidfile = -1;
638	if (pszPidfile != NULL)
639	{
640	/* @note the exclusive create is not guaranteed on all file
641	* systems (e.g. NFSv2) */
642	if ((fdPidfile = open(pszPidfile, O_RDWR \| O_CREAT \| O_EXCL, 0644)) == -1)
643	return RTErrConvertFromErrno(errno);
644	}
645
646	/* Ignore SIGHUP straight away. */
647	struct sigaction OldSigAct;
648	struct sigaction SigAct;
649	memset(&SigAct, 0, sizeof(SigAct));
650	SigAct.sa_handler = SIG_IGN;
651	int rcSigAct = sigaction(SIGHUP, &SigAct, &OldSigAct);
652
653	/* First fork, to become independent process. */
654	pid_t pid = fork();
655	if (pid == -1)
656	return RTErrConvertFromErrno(errno);
657	if (pid != 0)
658	{
659	/* Parent exits, no longer necessary. The child gets reparented
660	* to the init process. */
661	exit(0);
662	}
663
664	/* Create new session, fix up the standard file descriptors and the
665	* current working directory. */
666	/** @todo r=klaus the webservice uses this function and assumes that the
667	* contract id of the daemon is the same as that of the original process.
668	* Whenever this code is changed this must still remain possible. */
669	pid_t newpgid = setsid();
670	int SavedErrno = errno;
671	if (rcSigAct != -1)
672	sigaction(SIGHUP, &OldSigAct, NULL);
673	if (newpgid == -1)
674	return RTErrConvertFromErrno(SavedErrno);
675
676	if (!fNoClose)
677	{
678	/* Open stdin(0), stdout(1) and stderr(2) as /dev/null. */
679	int fd = open("/dev/null", O_RDWR);
680	if (fd == -1) /* paranoia */
681	{
682	close(STDIN_FILENO);
683	close(STDOUT_FILENO);
684	close(STDERR_FILENO);
685	fd = open("/dev/null", O_RDWR);
686	}
687	if (fd != -1)
688	{
689	dup2(fd, STDIN_FILENO);
690	dup2(fd, STDOUT_FILENO);
691	dup2(fd, STDERR_FILENO);
692	if (fd > 2)
693	close(fd);
694	}
695	}
696
697	if (!fNoChDir)
698	{
699	int rcIgnored = chdir("/");
700	NOREF(rcIgnored);
701	}
702
703	/* Second fork to lose session leader status. */
704	pid = fork();
705	if (pid == -1)
706	return RTErrConvertFromErrno(errno);
707
708	if (pid != 0)
709	{
710	/* Write the pid file, this is done in the parent, before exiting. */
711	if (fdPidfile != -1)
712	{
713	char szBuf[256];
714	size_t cbPid = RTStrPrintf(szBuf, sizeof(szBuf), "%d\n", pid);
715	ssize_t cbIgnored = write(fdPidfile, szBuf, cbPid); NOREF(cbIgnored);
716	close(fdPidfile);
717	}
718	exit(0);
719	}
720
721	return VINF_SUCCESS;
722	}
723

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source: vbox/trunk/src/VBox/Runtime/r3/posix/process-creation-posix.cpp@ 39032

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