process-posix.cpp@ 33009

Last change on this file since 33009 was 33009, checked in by vboxsync, 14 years ago
Runtime/Process: avoid a hanging around zombie process when creating a detached process on posix platforms
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1	/* $Id: process-posix.cpp 33009 2010-10-08 12:37:24Z vboxsync $ */
2	/** @file
3	* IPRT - Process, 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	/*******************************************************************************
30	* Header Files *
31	*******************************************************************************/
32	#define LOG_GROUP RTLOGGROUP_PROCESS
33	#include <unistd.h>
34	#include <stdlib.h>
35	#include <errno.h>
36	#include <sys/types.h>
37	#include <sys/stat.h>
38	#include <sys/wait.h>
39	#include <fcntl.h>
40	#include <signal.h>
41	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_SOLARIS)
42	# include <crypt.h>
43	# include <pwd.h>
44	# include <shadow.h>
45	#endif
46	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2)
47	/* While Solaris has posix_spawn() of course we don't want to use it as
48	* we need to have the child in a different process contract, no matter
49	* whether it is started detached or not. */
50	# define HAVE_POSIX_SPAWN 1
51	#endif
52	#ifdef HAVE_POSIX_SPAWN
53	# include <spawn.h>
54	#endif
55	#ifdef RT_OS_DARWIN
56	# include <mach-o/dyld.h>
57	#endif
58	#ifdef RT_OS_SOLARIS
59	# include <limits.h>
60	# include <sys/ctfs.h>
61	# include <sys/contract/process.h>
62	# include <libcontract.h>
63	#endif
64
65	#include <iprt/process.h>
66	#include "internal/iprt.h"
67
68	#include <iprt/assert.h>
69	#include <iprt/env.h>
70	#include <iprt/err.h>
71	#include <iprt/file.h>
72	#include <iprt/pipe.h>
73	#include <iprt/socket.h>
74	#include <iprt/string.h>
75	#include <iprt/mem.h>
76	#include "internal/process.h"
77
78
79	/**
80	* Check the credentials and return the gid/uid of user.
81	*
82	* @param pszUser username
83	* @param pszPasswd password
84	* @param gid where to store the GID of the user
85	* @param uid where to store the UID of the user
86	* @returns IPRT status code
87	*/
88	static int rtCheckCredentials(const char pszUser, const char pszPasswd, gid_t gid, uid_t uid)
89	{
90	#if defined(RT_OS_LINUX)
91	struct passwd *pw;
92
93	pw = getpwnam(pszUser);
94	if (!pw)
95	return VERR_PERMISSION_DENIED;
96
97	if (!pszPasswd)
98	pszPasswd = "";
99
100	struct spwd *spwd;
101	/* works only if /etc/shadow is accessible */
102	spwd = getspnam(pszUser);
103	if (spwd)
104	pw->pw_passwd = spwd->sp_pwdp;
105
106	/* be reentrant */
107	struct crypt_data data = (struct crypt_data)RTMemTmpAllocZ(sizeof(*data));
108	char *pszEncPasswd = crypt_r(pszPasswd, pw->pw_passwd, data);
109	if (strcmp(pszEncPasswd, pw->pw_passwd))
110	return VERR_PERMISSION_DENIED;
111	RTMemTmpFree(data);
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_DAEMONIZE_DEPRECATED \| RTPROC_FLAGS_DETACHED \| RTPROC_FLAGS_SERVICE)), 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	{
343	rc = RTErrConvertFromErrno(errno);
344	AssertMsgFailed(("'%s' %Rrc!\n", pszExec, rc));
345	return rc;
346	}
347
348	/*
349	* Spawn the child.
350	*
351	* HACK ALERT! Put the process into a new process group with pgid = pid
352	* to make sure it differs from that of the parent process to ensure that
353	* the IPRT waipit call doesn't race anyone (read XPCOM) doing group wide
354	* waits.
355	*/
356	pid_t pid = -1;
357	#ifdef HAVE_POSIX_SPAWN
358	/** @todo OS/2: implement DETACHED (BACKGROUND stuff), see VbglR3Daemonize. */
359	/** @todo Try do the detach thing with posix spawn. */
360	if ( !(fFlags & (RTPROC_FLAGS_DAEMONIZE_DEPRECATED \| RTPROC_FLAGS_DETACHED))
361	&& uid == ~(uid_t)0
362	&& gid == ~(gid_t)0
363	)
364	{
365	/* Spawn attributes. */
366	posix_spawnattr_t Attr;
367	rc = posix_spawnattr_init(&Attr);
368	if (!rc)
369	{
370	# ifndef RT_OS_OS2 /* We don't need this on OS/2 and I don't recall if it's actually implemented. */
371	rc = posix_spawnattr_setflags(&Attr, POSIX_SPAWN_SETPGROUP);
372	Assert(rc == 0);
373	if (!rc)
374	{
375	rc = posix_spawnattr_setpgroup(&Attr, 0 /* pg == child pid */);
376	Assert(rc == 0);
377	}
378	# endif
379
380	/* File changes. */
381	posix_spawn_file_actions_t FileActions;
382	posix_spawn_file_actions_t *pFileActions = NULL;
383	if (aStdFds[0] != -1 \|\| aStdFds[1] != -1 \|\| aStdFds[2] != -1)
384	{
385	rc = posix_spawn_file_actions_init(&FileActions);
386	if (!rc)
387	{
388	pFileActions = &FileActions;
389	for (int i = 0; i < 3; i++)
390	{
391	int fd = aStdFds[i];
392	if (fd == -2)
393	rc = posix_spawn_file_actions_addclose(&FileActions, i);
394	else if (fd >= 0 && fd != i)
395	{
396	rc = posix_spawn_file_actions_adddup2(&FileActions, fd, i);
397	if (!rc)
398	{
399	for (int j = i + 1; j < 3; j++)
400	if (aStdFds[j] == fd)
401	{
402	fd = -1;
403	break;
404	}
405	if (fd >= 0)
406	rc = posix_spawn_file_actions_addclose(&FileActions, fd);
407	}
408	}
409	if (rc)
410	break;
411	}
412	}
413	}
414
415	if (!rc)
416	rc = posix_spawn(&pid, pszExec, pFileActions, &Attr, (char * const *)papszArgs,
417	(char * const *)papszEnv);
418
419	/* cleanup */
420	int rc2 = posix_spawnattr_destroy(&Attr); Assert(rc2 == 0); NOREF(rc2);
421	if (pFileActions)
422	{
423	rc2 = posix_spawn_file_actions_destroy(pFileActions);
424	Assert(rc2 == 0);
425	}
426
427	/* return on success.*/
428	if (!rc)
429	{
430	if (phProcess)
431	*phProcess = pid;
432	return VINF_SUCCESS;
433	}
434	}
435	}
436	else
437	#endif
438	{
439	#ifdef RT_OS_SOLARIS
440	int templateFd = rtSolarisContractPreFork();
441	if (templateFd == -1)
442	return VERR_OPEN_FAILED;
443	#endif /* RT_OS_SOLARIS */
444	pid = fork();
445	if (!pid)
446	{
447	#ifdef RT_OS_SOLARIS
448	rtSolarisContractPostForkChild(templateFd);
449	#endif /* RT_OS_SOLARIS */
450	setpgid(0, 0); /* see comment above */
451
452	/*
453	* Change group and user if requested.
454	*/
455	#if 1 /** @todo This needs more work, see suplib/hardening. */
456	if (gid != ~(gid_t)0)
457	{
458	if (setgid(gid))
459	exit(126);
460	}
461
462	if (uid != ~(uid_t)0)
463	{
464	if (setuid(uid))
465	exit(126);
466	}
467	#endif
468
469	/*
470	* Apply changes to the standard file descriptor and stuff.
471	*/
472	for (int i = 0; i < 3; i++)
473	{
474	int fd = aStdFds[i];
475	if (fd == -2)
476	close(i);
477	else if (fd >= 0)
478	{
479	int rc2 = dup2(fd, i);
480	if (rc2 != i)
481	exit(125);
482	for (int j = i + 1; j < 3; j++)
483	if (aStdFds[j] == fd)
484	{
485	fd = -1;
486	break;
487	}
488	if (fd >= 0)
489	close(fd);
490	}
491	}
492
493	/*
494	* Daemonize the process if requested.
495	*/
496	if (fFlags & (RTPROC_FLAGS_DAEMONIZE_DEPRECATED \| RTPROC_FLAGS_DETACHED))
497	{
498	rc = RTProcDaemonizeUsingFork(true /fNoChDir/,
499	!(fFlags & RTPROC_FLAGS_DAEMONIZE_DEPRECATED) /fNoClose/,
500	NULL /* pszPidFile */);
501	if (RT_FAILURE(rc))
502	{
503	/* parent */
504	AssertReleaseMsgFailed(("RTProcDaemonize returns %Rrc errno=%d\n", rc, errno));
505	exit(127);
506	}
507	/* daemonized child */
508	}
509
510	/*
511	* Finally, execute the requested program.
512	*/
513	rc = execve(pszExec, (char * const )papszArgs, (char const *)papszEnv);
514	if (errno == ENOEXEC)
515	{
516	/* This can happen when trying to start a shell script without the magic #!/bin/sh */
517	RTAssertMsg2Weak("Cannot execute this binary format!\n");
518	}
519	else
520	RTAssertMsg2Weak("execve returns %d errno=%d\n", rc, errno);
521	RTAssertReleasePanic();
522	exit(127);
523	}
524	#ifdef RT_OS_SOLARIS
525	rtSolarisContractPostForkParent(templateFd, pid);
526	#endif /* RT_OS_SOLARIS */
527	if (pid > 0)
528	{
529	if (phProcess)
530	*phProcess = pid;
531	else if (fFlags & (RTPROC_FLAGS_DAEMONIZE_DEPRECATED \| RTPROC_FLAGS_DETACHED))
532	{
533	/* If the process is detached straight away wait for the
534	* intermediate process to exit (it should do that quickly)
535	* if the caller didn't want to know the PID. If it wants the
536	* PID it's his job to wait for it or he gets a zombie. */
537	waitpid(pid, NULL, 0);
538	}
539	return VINF_SUCCESS;
540	}
541	rc = errno;
542	}
543
544
545	return VERR_NOT_IMPLEMENTED;
546	}
547
548
549	RTR3DECL(int) RTProcWait(RTPROCESS Process, unsigned fFlags, PRTPROCSTATUS pProcStatus)
550	{
551	int rc;
552	do rc = RTProcWaitNoResume(Process, fFlags, pProcStatus);
553	while (rc == VERR_INTERRUPTED);
554	return rc;
555	}
556
557	RTR3DECL(int) RTProcWaitNoResume(RTPROCESS Process, unsigned fFlags, PRTPROCSTATUS pProcStatus)
558	{
559	/*
560	* Validate input.
561	*/
562	if (Process <= 0)
563	{
564	AssertMsgFailed(("Invalid Process=%d\n", Process));
565	return VERR_INVALID_PARAMETER;
566	}
567	if (fFlags & ~(RTPROCWAIT_FLAGS_NOBLOCK \| RTPROCWAIT_FLAGS_BLOCK))
568	{
569	AssertMsgFailed(("Invalid flags %#x\n", fFlags));
570	return VERR_INVALID_PARAMETER;
571	}
572
573	/*
574	* Perform the wait.
575	*/
576	int iStatus = 0;
577	int rc = waitpid(Process, &iStatus, fFlags & RTPROCWAIT_FLAGS_NOBLOCK ? WNOHANG : 0);
578	if (rc > 0)
579	{
580	/*
581	* Fill in the status structure.
582	*/
583	if (pProcStatus)
584	{
585	if (WIFEXITED(iStatus))
586	{
587	pProcStatus->enmReason = RTPROCEXITREASON_NORMAL;
588	pProcStatus->iStatus = WEXITSTATUS(iStatus);
589	}
590	else if (WIFSIGNALED(iStatus))
591	{
592	pProcStatus->enmReason = RTPROCEXITREASON_SIGNAL;
593	pProcStatus->iStatus = WTERMSIG(iStatus);
594	}
595	else
596	{
597	Assert(!WIFSTOPPED(iStatus));
598	pProcStatus->enmReason = RTPROCEXITREASON_ABEND;
599	pProcStatus->iStatus = iStatus;
600	}
601	}
602	return VINF_SUCCESS;
603	}
604
605	/*
606	* Child running?
607	*/
608	if (!rc)
609	{
610	Assert(fFlags & RTPROCWAIT_FLAGS_NOBLOCK);
611	return VERR_PROCESS_RUNNING;
612	}
613
614	/*
615	* Figure out which error to return.
616	*/
617	int iErr = errno;
618	if (iErr == ECHILD)
619	return VERR_PROCESS_NOT_FOUND;
620	return RTErrConvertFromErrno(iErr);
621	}
622
623
624	RTR3DECL(int) RTProcTerminate(RTPROCESS Process)
625	{
626	if (!kill(Process, SIGKILL))
627	return VINF_SUCCESS;
628	return RTErrConvertFromErrno(errno);
629	}
630
631
632	RTR3DECL(uint64_t) RTProcGetAffinityMask()
633	{
634	// @todo
635	return 1;
636	}
637
638
639	RTR3DECL(int) RTProcDaemonizeUsingFork(bool fNoChDir, bool fNoClose, const char *pszPidfile)
640	{
641	/*
642	* Fork the child process in a new session and quit the parent.
643	*
644	* - fork once and create a new session (setsid). This will detach us
645	* from the controlling tty meaning that we won't receive the SIGHUP
646	* (or any other signal) sent to that session.
647	* - The SIGHUP signal is ignored because the session/parent may throw
648	* us one before we get to the setsid.
649	* - When the parent exit(0) we will become an orphan and re-parented to
650	* the init process.
651	* - Because of the sometimes unexpected semantics of assigning the
652	* controlling tty automagically when a session leader first opens a tty,
653	* we will fork() once more to get rid of the session leadership role.
654	*/
655
656	/* We start off by opening the pidfile, so that we can fail straight away
657	* if it already exists. */
658	int fdPidfile = -1;
659	if (pszPidfile != NULL)
660	{
661	/* @note the exclusive create is not guaranteed on all file
662	* systems (e.g. NFSv2) */
663	if ((fdPidfile = open(pszPidfile, O_RDWR \| O_CREAT \| O_EXCL, 0644)) == -1)
664	return RTErrConvertFromErrno(errno);
665	}
666
667	/* Ignore SIGHUP straight away. */
668	struct sigaction OldSigAct;
669	struct sigaction SigAct;
670	memset(&SigAct, 0, sizeof(SigAct));
671	SigAct.sa_handler = SIG_IGN;
672	int rcSigAct = sigaction(SIGHUP, &SigAct, &OldSigAct);
673
674	/* First fork, to become independent process. */
675	pid_t pid = fork();
676	if (pid == -1)
677	return RTErrConvertFromErrno(errno);
678	if (pid != 0)
679	{
680	/* Parent exits, no longer necessary. The child gets reparented
681	* to the init process. */
682	exit(0);
683	}
684
685	/* Create new session, fix up the standard file descriptors and the
686	* current working directory. */
687	pid_t newpgid = setsid();
688	int SavedErrno = errno;
689	if (rcSigAct != -1)
690	sigaction(SIGHUP, &OldSigAct, NULL);
691	if (newpgid == -1)
692	return RTErrConvertFromErrno(SavedErrno);
693
694	if (!fNoClose)
695	{
696	/* Open stdin(0), stdout(1) and stderr(2) as /dev/null. */
697	int fd = open("/dev/null", O_RDWR);
698	if (fd == -1) /* paranoia */
699	{
700	close(STDIN_FILENO);
701	close(STDOUT_FILENO);
702	close(STDERR_FILENO);
703	fd = open("/dev/null", O_RDWR);
704	}
705	if (fd != -1)
706	{
707	dup2(fd, STDIN_FILENO);
708	dup2(fd, STDOUT_FILENO);
709	dup2(fd, STDERR_FILENO);
710	if (fd > 2)
711	close(fd);
712	}
713	}
714
715	if (!fNoChDir)
716	{
717	int rcChdir = chdir("/");
718	}
719
720	/* Second fork to lose session leader status. */
721	pid = fork();
722	if (pid == -1)
723	return RTErrConvertFromErrno(errno);
724
725	if (pid != 0)
726	{
727	/* Write the pid file, this is done in the parent, before exiting. */
728	if (fdPidfile != -1)
729	{
730	char szBuf[256];
731	size_t cbPid = RTStrPrintf(szBuf, sizeof(szBuf), "%d\n", pid);
732	int rcWrite = write(fdPidfile, szBuf, cbPid);
733	close(fdPidfile);
734	}
735	exit(0);
736	}
737
738	return VINF_SUCCESS;
739	}
740

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source: vbox/trunk/src/VBox/Runtime/r3/posix/process-posix.cpp@ 33009

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