process-creation-posix.cpp@ 77235

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1	/* $Id: process-creation-posix.cpp 76553 2019-01-01 01:45:53Z vboxsync $ */
2	/** @file
3	* IPRT - Process Creation, POSIX.
4	*/
5
6	/*
7	* Copyright (C) 2006-2019 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 <iprt/cdefs.h>
33
34	#include <unistd.h>
35	#include <stdlib.h>
36	#include <errno.h>
37	#include <sys/types.h>
38	#include <sys/stat.h>
39	#include <sys/wait.h>
40	#include <fcntl.h>
41	#include <signal.h>
42	#include <grp.h>
43	#include <pwd.h>
44	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_SOLARIS)
45	# include <crypt.h>
46	# include <shadow.h>
47	#endif
48
49	#if defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2)
50	/* While Solaris has posix_spawn() of course we don't want to use it as
51	* we need to have the child in a different process contract, no matter
52	* whether it is started detached or not. */
53	# define HAVE_POSIX_SPAWN 1
54	#endif
55	#if defined(RT_OS_DARWIN) && defined(MAC_OS_X_VERSION_MIN_REQUIRED)
56	# if MAC_OS_X_VERSION_MIN_REQUIRED >= 1050
57	# define HAVE_POSIX_SPAWN 1
58	# endif
59	#endif
60	#ifdef HAVE_POSIX_SPAWN
61	# include <spawn.h>
62	#endif
63
64	#ifdef RT_OS_DARWIN
65	# include <mach-o/dyld.h>
66	# include <security/pam_appl.h>
67	# include <stdlib.h>
68	# include <dlfcn.h>
69	# include <iprt/asm.h>
70	#endif
71
72	#ifdef RT_OS_SOLARIS
73	# include <limits.h>
74	# include <sys/ctfs.h>
75	# include <sys/contract/process.h>
76	# include <libcontract.h>
77	#endif
78
79	#ifndef RT_OS_SOLARIS
80	# include <paths.h>
81	#else
82	# define _PATH_MAILDIR "/var/mail"
83	# define _PATH_DEFPATH "/usr/bin:/bin"
84	# define _PATH_STDPATH "/sbin:/usr/sbin:/bin:/usr/bin"
85	#endif
86
87
88	#include <iprt/process.h>
89	#include "internal/iprt.h"
90
91	#include <iprt/assert.h>
92	#include <iprt/env.h>
93	#include <iprt/err.h>
94	#include <iprt/file.h>
95	#include <iprt/log.h>
96	#include <iprt/path.h>
97	#include <iprt/pipe.h>
98	#include <iprt/socket.h>
99	#include <iprt/string.h>
100	#include <iprt/mem.h>
101	#include "internal/process.h"
102
103
104	/*********************************************************************************************************************************
105	* Structures and Typedefs *
106	*********************************************************************************************************************************/
107	#ifdef RT_OS_DARWIN
108	/** For passing info between rtCheckCredentials and rtPamConv. */
109	typedef struct RTPROCPAMARGS
110	{
111	const char *pszUser;
112	const char *pszPassword;
113	} RTPROCPAMARGS;
114	/** Pointer to rtPamConv argument package. */
115	typedef RTPROCPAMARGS *PRTPROCPAMARGS;
116	#endif
117
118
119	#ifdef RT_OS_DARWIN
120	/**
121	* Worker for rtCheckCredentials that feeds password and maybe username to PAM.
122	*
123	* @returns PAM status.
124	* @param cMessages Number of messages.
125	* @param papMessages Message vector.
126	* @param ppaResponses Where to put our responses.
127	* @param pvAppData Pointer to RTPROCPAMARGS.
128	*/
129	static int rtPamConv(int cMessages, const struct pam_message papMessages, struct pam_response ppaResponses, void *pvAppData)
130	{
131	LogFlow(("rtPamConv: cMessages=%d\n", cMessages));
132	PRTPROCPAMARGS pArgs = (PRTPROCPAMARGS)pvAppData;
133	AssertPtrReturn(pArgs, PAM_CONV_ERR);
134
135	struct pam_response paResponses = (struct pam_response )calloc(cMessages, sizeof(paResponses[0]));
136	AssertReturn(paResponses, PAM_CONV_ERR);
137	for (int i = 0; i < cMessages; i++)
138	{
139	LogFlow(("rtPamConv: #%d: msg_style=%d msg=%s\n", i, papMessages[i]->msg_style, papMessages[i]->msg));
140
141	paResponses[i].resp_retcode = 0;
142	if (papMessages[i]->msg_style == PAM_PROMPT_ECHO_OFF)
143	paResponses[i].resp = strdup(pArgs->pszPassword);
144	else if (papMessages[i]->msg_style == PAM_PROMPT_ECHO_ON)
145	paResponses[i].resp = strdup(pArgs->pszUser);
146	else
147	{
148	paResponses[i].resp = NULL;
149	continue;
150	}
151	if (paResponses[i].resp == NULL)
152	{
153	while (i-- > 0)
154	free(paResponses[i].resp);
155	free(paResponses);
156	LogFlow(("rtPamConv: out of memory\n"));
157	return PAM_CONV_ERR;
158	}
159	}
160
161	*ppaResponses = paResponses;
162	return PAM_SUCCESS;
163	}
164	#endif /* RT_OS_DARWIN */
165
166
167	/**
168	* Check the credentials and return the gid/uid of user.
169	*
170	* @param pszUser username
171	* @param pszPasswd password
172	* @param gid where to store the GID of the user
173	* @param uid where to store the UID of the user
174	* @returns IPRT status code
175	*/
176	static int rtCheckCredentials(const char pszUser, const char pszPasswd, gid_t pGid, uid_t pUid)
177	{
178	#if defined(RT_OS_DARWIN)
179	RTLogPrintf("rtCheckCredentials\n");
180
181	/*
182	* Resolve user to UID and GID.
183	*/
184	char szBuf[_4K];
185	struct passwd Pw;
186	struct passwd *pPw;
187	if (getpwnam_r(pszUser, &Pw, szBuf, sizeof(szBuf), &pPw) != 0)
188	return VERR_AUTHENTICATION_FAILURE;
189	if (!pPw)
190	return VERR_AUTHENTICATION_FAILURE;
191
192	*pUid = pPw->pw_uid;
193	*pGid = pPw->pw_gid;
194
195	/*
196	* Use PAM for the authentication.
197	* Note! libpam.2.dylib was introduced with 10.6.x (OpenPAM).
198	*/
199	void *hModPam = dlopen("libpam.dylib", RTLD_LAZY \| RTLD_GLOBAL);
200	if (hModPam)
201	{
202	int (pfnPamStart)(const char , const char , struct pam_conv , pam_handle_t **);
203	int (pfnPamAuthenticate)(pam_handle_t , int);
204	int (pfnPamAcctMgmt)(pam_handle_t , int);
205	int (pfnPamSetItem)(pam_handle_t , int, const void *);
206	int (pfnPamEnd)(pam_handle_t , int);
207	(void *)&pfnPamStart = dlsym(hModPam, "pam_start");
208	(void *)&pfnPamAuthenticate = dlsym(hModPam, "pam_authenticate");
209	(void *)&pfnPamAcctMgmt = dlsym(hModPam, "pam_acct_mgmt");
210	(void *)&pfnPamSetItem = dlsym(hModPam, "pam_set_item");
211	(void *)&pfnPamEnd = dlsym(hModPam, "pam_end");
212	ASMCompilerBarrier();
213	if ( pfnPamStart
214	&& pfnPamAuthenticate
215	&& pfnPamAcctMgmt
216	&& pfnPamSetItem
217	&& pfnPamEnd)
218	{
219	#define pam_start pfnPamStart
220	#define pam_authenticate pfnPamAuthenticate
221	#define pam_acct_mgmt pfnPamAcctMgmt
222	#define pam_set_item pfnPamSetItem
223	#define pam_end pfnPamEnd
224
225	/* Do the PAM stuff.
226	Note! Abusing 'login' here for now... */
227	pam_handle_t *hPam = NULL;
228	RTPROCPAMARGS PamConvArgs = { pszUser, pszPasswd };
229	struct pam_conv PamConversation;
230	RT_ZERO(PamConversation);
231	PamConversation.appdata_ptr = &PamConvArgs;
232	PamConversation.conv = rtPamConv;
233	int rc = pam_start("login", pszUser, &PamConversation, &hPam);
234	if (rc == PAM_SUCCESS)
235	{
236	rc = pam_set_item(hPam, PAM_RUSER, pszUser);
237	if (rc == PAM_SUCCESS)
238	rc = pam_authenticate(hPam, 0);
239	if (rc == PAM_SUCCESS)
240	{
241	rc = pam_acct_mgmt(hPam, 0);
242	if ( rc == PAM_SUCCESS
243	\|\| rc == PAM_AUTHINFO_UNAVAIL /??/)
244	{
245	pam_end(hPam, PAM_SUCCESS);
246	dlclose(hModPam);
247	return VINF_SUCCESS;
248	}
249	Log(("rtCheckCredentials: pam_acct_mgmt -> %d\n", rc));
250	}
251	else
252	Log(("rtCheckCredentials: pam_authenticate -> %d\n", rc));
253	pam_end(hPam, rc);
254	}
255	else
256	Log(("rtCheckCredentials: pam_start -> %d\n", rc));
257	}
258	else
259	Log(("rtCheckCredentials: failed to resolve symbols: %p %p %p %p %p\n",
260	pfnPamStart, pfnPamAuthenticate, pfnPamAcctMgmt, pfnPamSetItem, pfnPamEnd));
261	dlclose(hModPam);
262	}
263	else
264	Log(("rtCheckCredentials: Loading libpam.dylib failed\n"));
265	return VERR_AUTHENTICATION_FAILURE;
266
267	#elif defined(RT_OS_LINUX)
268	struct passwd *pw;
269
270	pw = getpwnam(pszUser);
271	if (!pw)
272	return VERR_AUTHENTICATION_FAILURE;
273
274	if (!pszPasswd)
275	pszPasswd = "";
276
277	struct spwd *spwd;
278	/* works only if /etc/shadow is accessible */
279	spwd = getspnam(pszUser);
280	if (spwd)
281	pw->pw_passwd = spwd->sp_pwdp;
282
283	/* Default fCorrect=true if no password specified. In that case, pw->pw_passwd
284	* must be NULL (no password set for this user). Fail if a password is specified
285	* but the user does not have one assigned. */
286	int fCorrect = !pszPasswd \|\| !*pszPasswd;
287	if (pw->pw_passwd && *pw->pw_passwd)
288	{
289	struct crypt_data data = (struct crypt_data)RTMemTmpAllocZ(sizeof(*data));
290	/* be reentrant */
291	char *pszEncPasswd = crypt_r(pszPasswd, pw->pw_passwd, data);
292	fCorrect = pszEncPasswd && !strcmp(pszEncPasswd, pw->pw_passwd);
293	RTMemTmpFree(data);
294	}
295	if (!fCorrect)
296	return VERR_AUTHENTICATION_FAILURE;
297
298	*pGid = pw->pw_gid;
299	*pUid = pw->pw_uid;
300	return VINF_SUCCESS;
301
302	#elif defined(RT_OS_SOLARIS)
303	struct passwd *ppw, pw;
304	char szBuf[1024];
305
306	if (getpwnam_r(pszUser, &pw, szBuf, sizeof(szBuf), &ppw) != 0 \|\| ppw == NULL)
307	return VERR_AUTHENTICATION_FAILURE;
308
309	if (!pszPasswd)
310	pszPasswd = "";
311
312	struct spwd spwd;
313	char szPwdBuf[1024];
314	/* works only if /etc/shadow is accessible */
315	if (getspnam_r(pszUser, &spwd, szPwdBuf, sizeof(szPwdBuf)) != NULL)
316	ppw->pw_passwd = spwd.sp_pwdp;
317
318	char *pszEncPasswd = crypt(pszPasswd, ppw->pw_passwd);
319	if (strcmp(pszEncPasswd, ppw->pw_passwd))
320	return VERR_AUTHENTICATION_FAILURE;
321
322	*pGid = ppw->pw_gid;
323	*pUid = ppw->pw_uid;
324	return VINF_SUCCESS;
325
326	#else
327	NOREF(pszUser); NOREF(pszPasswd); NOREF(pGid); NOREF(pUid);
328	return VERR_AUTHENTICATION_FAILURE;
329	#endif
330	}
331
332	#ifdef RT_OS_SOLARIS
333
334	/** @todo the error reporting of the Solaris process contract code could be
335	* a lot better, but essentially it is not meant to run into errors after
336	* the debugging phase. */
337	static int rtSolarisContractPreFork(void)
338	{
339	int templateFd = open64(CTFS_ROOT "/process/template", O_RDWR);
340	if (templateFd < 0)
341	return -1;
342
343	/* Set template parameters and event sets. */
344	if (ct_pr_tmpl_set_param(templateFd, CT_PR_PGRPONLY))
345	{
346	close(templateFd);
347	return -1;
348	}
349	if (ct_pr_tmpl_set_fatal(templateFd, CT_PR_EV_HWERR))
350	{
351	close(templateFd);
352	return -1;
353	}
354	if (ct_tmpl_set_critical(templateFd, 0))
355	{
356	close(templateFd);
357	return -1;
358	}
359	if (ct_tmpl_set_informative(templateFd, CT_PR_EV_HWERR))
360	{
361	close(templateFd);
362	return -1;
363	}
364
365	/* Make this the active template for the process. */
366	if (ct_tmpl_activate(templateFd))
367	{
368	close(templateFd);
369	return -1;
370	}
371
372	return templateFd;
373	}
374
375	static void rtSolarisContractPostForkChild(int templateFd)
376	{
377	if (templateFd == -1)
378	return;
379
380	/* Clear the active template. */
381	ct_tmpl_clear(templateFd);
382	close(templateFd);
383	}
384
385	static void rtSolarisContractPostForkParent(int templateFd, pid_t pid)
386	{
387	if (templateFd == -1)
388	return;
389
390	/* Clear the active template. */
391	int cleared = ct_tmpl_clear(templateFd);
392	close(templateFd);
393
394	/* If the clearing failed or the fork failed there's nothing more to do. */
395	if (cleared \|\| pid <= 0)
396	return;
397
398	/* Look up the contract which was created by this thread. */
399	int statFd = open64(CTFS_ROOT "/process/latest", O_RDONLY);
400	if (statFd == -1)
401	return;
402	ct_stathdl_t statHdl;
403	if (ct_status_read(statFd, CTD_COMMON, &statHdl))
404	{
405	close(statFd);
406	return;
407	}
408	ctid_t ctId = ct_status_get_id(statHdl);
409	ct_status_free(statHdl);
410	close(statFd);
411	if (ctId < 0)
412	return;
413
414	/* Abandon this contract we just created. */
415	char ctlPath[PATH_MAX];
416	size_t len = snprintf(ctlPath, sizeof(ctlPath),
417	CTFS_ROOT "/process/%ld/ctl", (long)ctId);
418	if (len >= sizeof(ctlPath))
419	return;
420	int ctlFd = open64(ctlPath, O_WRONLY);
421	if (statFd == -1)
422	return;
423	if (ct_ctl_abandon(ctlFd) < 0)
424	{
425	close(ctlFd);
426	return;
427	}
428	close(ctlFd);
429	}
430
431	#endif /* RT_OS_SOLARIS */
432
433
434	RTR3DECL(int) RTProcCreate(const char pszExec, const char const *papszArgs, RTENV Env, unsigned fFlags, PRTPROCESS pProcess)
435	{
436	return RTProcCreateEx(pszExec, papszArgs, Env, fFlags,
437	NULL, NULL, NULL, /* standard handles */
438	NULL /pszAsUser/, NULL /* pszPassword*/,
439	pProcess);
440	}
441
442
443	/**
444	* Adjust the profile environment after forking the child process and changing
445	* the UID.
446	*
447	* @returns IRPT status code.
448	* @param hEnvToUse The environment we're going to use with execve.
449	* @param fFlags The process creation flags.
450	* @param hEnv The environment passed in by the user.
451	*/
452	static int rtProcPosixAdjustProfileEnvFromChild(RTENV hEnvToUse, uint32_t fFlags, RTENV hEnv)
453	{
454	int rc = VINF_SUCCESS;
455	#ifdef RT_OS_DARWIN
456	if ( RT_SUCCESS(rc)
457	&& (!(fFlags & RTPROC_FLAGS_ENV_CHANGE_RECORD) \|\| RTEnvExistEx(hEnv, "TMPDIR")) )
458	{
459	char szValue[_4K];
460	size_t cbNeeded = confstr(_CS_DARWIN_USER_TEMP_DIR, szValue, sizeof(szValue));
461	if (cbNeeded > 0 && cbNeeded < sizeof(szValue))
462	{
463	char *pszTmp;
464	rc = RTStrCurrentCPToUtf8(&pszTmp, szValue);
465	if (RT_SUCCESS(rc))
466	{
467	rc = RTEnvSetEx(hEnvToUse, "TMPDIR", pszTmp);
468	RTStrFree(pszTmp);
469	}
470	}
471	else
472	rc = VERR_BUFFER_OVERFLOW;
473	}
474	#else
475	RT_NOREF_PV(hEnvToUse); RT_NOREF_PV(fFlags); RT_NOREF_PV(hEnv);
476	#endif
477	return rc;
478	}
479
480
481	/**
482	* Create a very very basic environment for a user.
483	*
484	* @returns IPRT status code.
485	* @param phEnvToUse Where to return the created environment.
486	* @param pszUser The user name for the profile.
487	*/
488	static int rtProcPosixCreateProfileEnv(PRTENV phEnvToUse, const char *pszUser)
489	{
490	struct passwd Pwd;
491	struct passwd *pPwd = NULL;
492	char achBuf[_4K];
493	int rc;
494	errno = 0;
495	if (pszUser)
496	rc = getpwnam_r(pszUser, &Pwd, achBuf, sizeof(achBuf), &pPwd);
497	else
498	rc = getpwuid_r(getuid(), &Pwd, achBuf, sizeof(achBuf), &pPwd);
499	if (rc == 0 && pPwd)
500	{
501	char *pszDir;
502	rc = RTStrCurrentCPToUtf8(&pszDir, pPwd->pw_dir);
503	if (RT_SUCCESS(rc))
504	{
505	char *pszShell;
506	rc = RTStrCurrentCPToUtf8(&pszShell, pPwd->pw_shell);
507	if (RT_SUCCESS(rc))
508	{
509	char *pszUserFree = NULL;
510	if (!pszUser)
511	{
512	rc = RTStrCurrentCPToUtf8(&pszUserFree, pPwd->pw_name);
513	if (RT_SUCCESS(rc))
514	pszUser = pszUserFree;
515	}
516	if (RT_SUCCESS(rc))
517	{
518	rc = RTEnvCreate(phEnvToUse);
519	if (RT_SUCCESS(rc))
520	{
521	RTENV hEnvToUse = *phEnvToUse;
522
523	rc = RTEnvSetEx(hEnvToUse, "HOME", pszDir);
524	if (RT_SUCCESS(rc))
525	rc = RTEnvSetEx(hEnvToUse, "SHELL", pszShell);
526	if (RT_SUCCESS(rc))
527	rc = RTEnvSetEx(hEnvToUse, "USER", pszUser);
528	if (RT_SUCCESS(rc))
529	rc = RTEnvSetEx(hEnvToUse, "LOGNAME", pszUser);
530
531	if (RT_SUCCESS(rc))
532	rc = RTEnvSetEx(hEnvToUse, "PATH", pPwd->pw_uid == 0 ? _PATH_STDPATH : _PATH_DEFPATH);
533
534	if (RT_SUCCESS(rc))
535	{
536	RTStrPrintf(achBuf, sizeof(achBuf), "%s/%s", _PATH_MAILDIR, pszUser);
537	rc = RTEnvSetEx(hEnvToUse, "MAIL", achBuf);
538	}
539
540	#ifdef RT_OS_DARWIN
541	if (RT_SUCCESS(rc) && !pszUserFree)
542	{
543	size_t cbNeeded = confstr(_CS_DARWIN_USER_TEMP_DIR, achBuf, sizeof(achBuf));
544	if (cbNeeded > 0 && cbNeeded < sizeof(achBuf))
545	{
546	char *pszTmp;
547	rc = RTStrCurrentCPToUtf8(&pszTmp, achBuf);
548	if (RT_SUCCESS(rc))
549	{
550	rc = RTEnvSetEx(hEnvToUse, "TMPDIR", pszTmp);
551	RTStrFree(pszTmp);
552	}
553	}
554	else
555	rc = VERR_BUFFER_OVERFLOW;
556	}
557	#endif
558
559	/** @todo load /etc/environment, /etc/profile.env and ~/.pam_environment? */
560
561	if (RT_FAILURE(rc))
562	RTEnvDestroy(hEnvToUse);
563	}
564	RTStrFree(pszUserFree);
565	}
566	RTStrFree(pszShell);
567	}
568	RTStrFree(pszDir);
569	}
570	}
571	else
572	rc = errno ? RTErrConvertFromErrno(errno) : VERR_ACCESS_DENIED;
573	return rc;
574	}
575
576
577	/**
578	* RTPathTraverseList callback used by RTProcCreateEx to locate the executable.
579	*/
580	static DECLCALLBACK(int) rtPathFindExec(char const pchPath, size_t cchPath, void pvUser1, void *pvUser2)
581	{
582	const char pszExec = (const char )pvUser1;
583	char pszRealExec = (char )pvUser2;
584	int rc = RTPathJoinEx(pszRealExec, RTPATH_MAX, pchPath, cchPath, pszExec, RTSTR_MAX);
585	if (RT_FAILURE(rc))
586	return rc;
587	if (!access(pszRealExec, X_OK))
588	return VINF_SUCCESS;
589	if ( errno == EACCES
590	\|\| errno == EPERM)
591	return RTErrConvertFromErrno(errno);
592	return VERR_TRY_AGAIN;
593	}
594
595	/**
596	* Cleans up the environment on the way out.
597	*/
598	static int rtProcPosixCreateReturn(int rc, RTENV hEnvToUse, RTENV hEnv)
599	{
600	if (hEnvToUse != hEnv)
601	RTEnvDestroy(hEnvToUse);
602	return rc;
603	}
604
605
606	RTR3DECL(int) RTProcCreateEx(const char pszExec, const char const *papszArgs, RTENV hEnv, uint32_t fFlags,
607	PCRTHANDLE phStdIn, PCRTHANDLE phStdOut, PCRTHANDLE phStdErr, const char *pszAsUser,
608	const char *pszPassword, PRTPROCESS phProcess)
609	{
610	int rc;
611	LogFlow(("RTProcCreateEx: pszExec=%s pszAsUser=%s\n", pszExec, pszAsUser));
612
613	/*
614	* Input validation
615	*/
616	AssertPtrReturn(pszExec, VERR_INVALID_POINTER);
617	AssertReturn(*pszExec, VERR_INVALID_PARAMETER);
618	AssertReturn(!(fFlags & ~RTPROC_FLAGS_VALID_MASK), VERR_INVALID_PARAMETER);
619	AssertReturn(!(fFlags & RTPROC_FLAGS_DETACHED) \|\| !phProcess, VERR_INVALID_PARAMETER);
620	AssertReturn(hEnv != NIL_RTENV, VERR_INVALID_PARAMETER);
621	AssertPtrReturn(papszArgs, VERR_INVALID_PARAMETER);
622	AssertPtrNullReturn(pszAsUser, VERR_INVALID_POINTER);
623	AssertReturn(!pszAsUser \|\| *pszAsUser, VERR_INVALID_PARAMETER);
624	AssertReturn(!pszPassword \|\| pszAsUser, VERR_INVALID_PARAMETER);
625	AssertPtrNullReturn(pszPassword, VERR_INVALID_POINTER);
626	#if defined(RT_OS_OS2)
627	if (fFlags & RTPROC_FLAGS_DETACHED)
628	return VERR_PROC_DETACH_NOT_SUPPORTED;
629	#endif
630
631	/*
632	* Get the file descriptors for the handles we've been passed.
633	*/
634	PCRTHANDLE paHandles[3] = { phStdIn, phStdOut, phStdErr };
635	int aStdFds[3] = { -1, -1, -1 };
636	for (int i = 0; i < 3; i++)
637	{
638	if (paHandles[i])
639	{
640	AssertPtrReturn(paHandles[i], VERR_INVALID_POINTER);
641	switch (paHandles[i]->enmType)
642	{
643	case RTHANDLETYPE_FILE:
644	aStdFds[i] = paHandles[i]->u.hFile != NIL_RTFILE
645	? (int)RTFileToNative(paHandles[i]->u.hFile)
646	: -2 /* close it */;
647	break;
648
649	case RTHANDLETYPE_PIPE:
650	aStdFds[i] = paHandles[i]->u.hPipe != NIL_RTPIPE
651	? (int)RTPipeToNative(paHandles[i]->u.hPipe)
652	: -2 /* close it */;
653	break;
654
655	case RTHANDLETYPE_SOCKET:
656	aStdFds[i] = paHandles[i]->u.hSocket != NIL_RTSOCKET
657	? (int)RTSocketToNative(paHandles[i]->u.hSocket)
658	: -2 /* close it */;
659	break;
660
661	default:
662	AssertMsgFailedReturn(("%d: %d\n", i, paHandles[i]->enmType), VERR_INVALID_PARAMETER);
663	}
664	/** @todo check the close-on-execness of these handles? */
665	}
666	}
667
668	for (int i = 0; i < 3; i++)
669	if (aStdFds[i] == i)
670	aStdFds[i] = -1;
671
672	for (int i = 0; i < 3; i++)
673	AssertMsgReturn(aStdFds[i] < 0 \|\| aStdFds[i] > i,
674	("%i := %i not possible because we're lazy\n", i, aStdFds[i]),
675	VERR_NOT_SUPPORTED);
676
677	/*
678	* Resolve the user id if specified.
679	*/
680	uid_t uid = ~(uid_t)0;
681	gid_t gid = ~(gid_t)0;
682	if (pszAsUser)
683	{
684	rc = rtCheckCredentials(pszAsUser, pszPassword, &gid, &uid);
685	if (RT_FAILURE(rc))
686	return rc;
687	}
688
689	/*
690	* Create the child environment if either RTPROC_FLAGS_PROFILE or
691	* RTPROC_FLAGS_ENV_CHANGE_RECORD are in effect.
692	*/
693	RTENV hEnvToUse = hEnv;
694	if ( (fFlags & (RTPROC_FLAGS_ENV_CHANGE_RECORD \| RTPROC_FLAGS_PROFILE))
695	&& ( (fFlags & RTPROC_FLAGS_ENV_CHANGE_RECORD)
696	\|\| hEnv == RTENV_DEFAULT) )
697	{
698	if (fFlags & RTPROC_FLAGS_PROFILE)
699	rc = rtProcPosixCreateProfileEnv(&hEnvToUse, pszAsUser);
700	else
701	rc = RTEnvClone(&hEnvToUse, RTENV_DEFAULT);
702	if (RT_SUCCESS(rc))
703	{
704	if ((fFlags & RTPROC_FLAGS_ENV_CHANGE_RECORD) && hEnv != RTENV_DEFAULT)
705	rc = RTEnvApplyChanges(hEnvToUse, hEnv);
706	if (RT_FAILURE(rc))
707	RTEnvDestroy(hEnvToUse);
708	}
709	if (RT_FAILURE(rc))
710	return rc;
711	}
712
713	/*
714	* Check for execute access to the file.
715	*/
716	char szRealExec[RTPATH_MAX];
717	if (access(pszExec, X_OK))
718	{
719	rc = errno;
720	if ( !(fFlags & RTPROC_FLAGS_SEARCH_PATH)
721	\|\| rc != ENOENT
722	\|\| RTPathHavePath(pszExec) )
723	rc = RTErrConvertFromErrno(rc);
724	else
725	{
726	/* search */
727	char *pszPath = RTEnvDupEx(hEnvToUse, "PATH");
728	rc = RTPathTraverseList(pszPath, ':', rtPathFindExec, (void *)pszExec, &szRealExec[0]);
729	RTStrFree(pszPath);
730	if (RT_SUCCESS(rc))
731	pszExec = szRealExec;
732	else
733	rc = rc == VERR_END_OF_STRING ? VERR_FILE_NOT_FOUND : rc;
734	}
735
736	if (RT_FAILURE(rc))
737	return rtProcPosixCreateReturn(rc, hEnvToUse, hEnv);
738	}
739
740	pid_t pid = -1;
741	const char * const *papszEnv = RTEnvGetExecEnvP(hEnvToUse);
742	AssertPtrReturn(papszEnv, rtProcPosixCreateReturn(VERR_INVALID_HANDLE, hEnvToUse, hEnv));
743
744
745	/*
746	* Take care of detaching the process.
747	*
748	* HACK ALERT! Put the process into a new process group with pgid = pid
749	* to make sure it differs from that of the parent process to ensure that
750	* the IPRT waitpid call doesn't race anyone (read XPCOM) doing group wide
751	* waits. setsid() includes the setpgid() functionality.
752	* 2010-10-11 XPCOM no longer waits for anything, but it cannot hurt.
753	*/
754	#ifndef RT_OS_OS2
755	if (fFlags & RTPROC_FLAGS_DETACHED)
756	{
757	# ifdef RT_OS_SOLARIS
758	int templateFd = -1;
759	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
760	{
761	templateFd = rtSolarisContractPreFork();
762	if (templateFd == -1)
763	return rtProcPosixCreateReturn(VERR_OPEN_FAILED, hEnvToUse, hEnv);
764	}
765	# endif /* RT_OS_SOLARIS */
766	pid = fork();
767	if (!pid)
768	{
769	# ifdef RT_OS_SOLARIS
770	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
771	rtSolarisContractPostForkChild(templateFd);
772	# endif
773	setsid(); /* see comment above */
774
775	pid = -1;
776	/* Child falls through to the actual spawn code below. */
777	}
778	else
779	{
780	# ifdef RT_OS_SOLARIS
781	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
782	rtSolarisContractPostForkParent(templateFd, pid);
783	# endif
784	if (pid > 0)
785	{
786	/* Must wait for the temporary process to avoid a zombie. */
787	int status = 0;
788	pid_t pidChild = 0;
789
790	/* Restart if we get interrupted. */
791	do
792	{
793	pidChild = waitpid(pid, &status, 0);
794	} while ( pidChild == -1
795	&& errno == EINTR);
796
797	/* Assume that something wasn't found. No detailed info. */
798	if (status)
799	return rtProcPosixCreateReturn(VERR_PROCESS_NOT_FOUND, hEnvToUse, hEnv);
800	if (phProcess)
801	*phProcess = 0;
802	return rtProcPosixCreateReturn(VINF_SUCCESS, hEnvToUse, hEnv);
803	}
804	return rtProcPosixCreateReturn(RTErrConvertFromErrno(errno), hEnvToUse, hEnv);
805	}
806	}
807	#endif
808
809	/*
810	* Spawn the child.
811	*
812	* Any spawn code MUST not execute any atexit functions if it is for a
813	* detached process. It would lead to running the atexit functions which
814	* make only sense for the parent. libORBit e.g. gets confused by multiple
815	* execution. Remember, there was only a fork() so far, and until exec()
816	* is successfully run there is nothing which would prevent doing anything
817	* silly with the (duplicated) file descriptors.
818	*/
819	#ifdef HAVE_POSIX_SPAWN
820	/** @todo OS/2: implement DETACHED (BACKGROUND stuff), see VbglR3Daemonize. */
821	if ( uid == ~(uid_t)0
822	&& gid == ~(gid_t)0)
823	{
824	/* Spawn attributes. */
825	posix_spawnattr_t Attr;
826	rc = posix_spawnattr_init(&Attr);
827	if (!rc)
828	{
829	/* Indicate that process group and signal mask are to be changed,
830	and that the child should use default signal actions. */
831	rc = posix_spawnattr_setflags(&Attr, POSIX_SPAWN_SETPGROUP \| POSIX_SPAWN_SETSIGMASK \| POSIX_SPAWN_SETSIGDEF);
832	Assert(rc == 0);
833
834	/* The child starts in its own process group. */
835	if (!rc)
836	{
837	rc = posix_spawnattr_setpgroup(&Attr, 0 /* pg == child pid */);
838	Assert(rc == 0);
839	}
840
841	/* Unmask all signals. */
842	if (!rc)
843	{
844	sigset_t SigMask;
845	sigemptyset(&SigMask);
846	rc = posix_spawnattr_setsigmask(&Attr, &SigMask); Assert(rc == 0);
847	}
848
849	/* File changes. */
850	posix_spawn_file_actions_t FileActions;
851	posix_spawn_file_actions_t *pFileActions = NULL;
852	if ((aStdFds[0] != -1 \|\| aStdFds[1] != -1 \|\| aStdFds[2] != -1) && !rc)
853	{
854	rc = posix_spawn_file_actions_init(&FileActions);
855	if (!rc)
856	{
857	pFileActions = &FileActions;
858	for (int i = 0; i < 3; i++)
859	{
860	int fd = aStdFds[i];
861	if (fd == -2)
862	rc = posix_spawn_file_actions_addclose(&FileActions, i);
863	else if (fd >= 0 && fd != i)
864	{
865	rc = posix_spawn_file_actions_adddup2(&FileActions, fd, i);
866	if (!rc)
867	{
868	for (int j = i + 1; j < 3; j++)
869	if (aStdFds[j] == fd)
870	{
871	fd = -1;
872	break;
873	}
874	if (fd >= 0)
875	rc = posix_spawn_file_actions_addclose(&FileActions, fd);
876	}
877	}
878	if (rc)
879	break;
880	}
881	}
882	}
883
884	if (!rc)
885	rc = posix_spawn(&pid, pszExec, pFileActions, &Attr, (char * const *)papszArgs,
886	(char * const *)papszEnv);
887
888	/* cleanup */
889	int rc2 = posix_spawnattr_destroy(&Attr); Assert(rc2 == 0); NOREF(rc2);
890	if (pFileActions)
891	{
892	rc2 = posix_spawn_file_actions_destroy(pFileActions);
893	Assert(rc2 == 0);
894	}
895
896	/* return on success.*/
897	if (!rc)
898	{
899	/* For a detached process this happens in the temp process, so
900	* it's not worth doing anything as this process must exit. */
901	if (fFlags & RTPROC_FLAGS_DETACHED)
902	_Exit(0);
903	if (phProcess)
904	*phProcess = pid;
905	return rtProcPosixCreateReturn(VINF_SUCCESS, hEnvToUse, hEnv);
906	}
907	}
908	/* For a detached process this happens in the temp process, so
909	* it's not worth doing anything as this process must exit. */
910	if (fFlags & RTPROC_FLAGS_DETACHED)
911	_Exit(124);
912	}
913	else
914	#endif
915	{
916	#ifdef RT_OS_SOLARIS
917	int templateFd = -1;
918	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
919	{
920	templateFd = rtSolarisContractPreFork();
921	if (templateFd == -1)
922	return rtProcPosixCreateReturn(VERR_OPEN_FAILED, hEnvToUse, hEnv);
923	}
924	#endif /* RT_OS_SOLARIS */
925	pid = fork();
926	if (!pid)
927	{
928	#ifdef RT_OS_SOLARIS
929	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
930	rtSolarisContractPostForkChild(templateFd);
931	#endif /* RT_OS_SOLARIS */
932	if (!(fFlags & RTPROC_FLAGS_DETACHED))
933	setpgid(0, 0); /* see comment above */
934
935	/*
936	* Change group and user if requested.
937	*/
938	#if 1 /** @todo This needs more work, see suplib/hardening. */
939	if (pszAsUser)
940	{
941	int ret = initgroups(pszAsUser, gid);
942	if (ret)
943	{
944	if (fFlags & RTPROC_FLAGS_DETACHED)
945	_Exit(126);
946	else
947	exit(126);
948	}
949	}
950	if (gid != ~(gid_t)0)
951	{
952	if (setgid(gid))
953	{
954	if (fFlags & RTPROC_FLAGS_DETACHED)
955	_Exit(126);
956	else
957	exit(126);
958	}
959	}
960
961	if (uid != ~(uid_t)0)
962	{
963	if (setuid(uid))
964	{
965	if (fFlags & RTPROC_FLAGS_DETACHED)
966	_Exit(126);
967	else
968	exit(126);
969	}
970	}
971	#endif
972
973	/*
974	* Some final profile environment tweaks, if running as user.
975	*/
976	if ( (fFlags & RTPROC_FLAGS_PROFILE)
977	&& pszAsUser
978	&& ( (fFlags & RTPROC_FLAGS_ENV_CHANGE_RECORD)
979	\|\| hEnv == RTENV_DEFAULT) )
980	{
981	rc = rtProcPosixAdjustProfileEnvFromChild(hEnvToUse, fFlags, hEnv);
982	papszEnv = RTEnvGetExecEnvP(hEnvToUse);
983	if (RT_FAILURE(rc) \|\| !papszEnv)
984	{
985	if (fFlags & RTPROC_FLAGS_DETACHED)
986	_Exit(126);
987	else
988	exit(126);
989	}
990	}
991
992	/*
993	* Unset the signal mask.
994	*/
995	sigset_t SigMask;
996	sigemptyset(&SigMask);
997	rc = sigprocmask(SIG_SETMASK, &SigMask, NULL);
998	Assert(rc == 0);
999
1000	/*
1001	* Apply changes to the standard file descriptor and stuff.
1002	*/
1003	for (int i = 0; i < 3; i++)
1004	{
1005	int fd = aStdFds[i];
1006	if (fd == -2)
1007	close(i);
1008	else if (fd >= 0)
1009	{
1010	int rc2 = dup2(fd, i);
1011	if (rc2 != i)
1012	{
1013	if (fFlags & RTPROC_FLAGS_DETACHED)
1014	_Exit(125);
1015	else
1016	exit(125);
1017	}
1018	for (int j = i + 1; j < 3; j++)
1019	if (aStdFds[j] == fd)
1020	{
1021	fd = -1;
1022	break;
1023	}
1024	if (fd >= 0)
1025	close(fd);
1026	}
1027	}
1028
1029	/*
1030	* Finally, execute the requested program.
1031	*/
1032	rc = execve(pszExec, (char * const )papszArgs, (char const *)papszEnv);
1033	if (errno == ENOEXEC)
1034	{
1035	/* This can happen when trying to start a shell script without the magic #!/bin/sh */
1036	RTAssertMsg2Weak("Cannot execute this binary format!\n");
1037	}
1038	else
1039	RTAssertMsg2Weak("execve returns %d errno=%d\n", rc, errno);
1040	RTAssertReleasePanic();
1041	if (fFlags & RTPROC_FLAGS_DETACHED)
1042	_Exit(127);
1043	else
1044	exit(127);
1045	}
1046	#ifdef RT_OS_SOLARIS
1047	if (!(fFlags & RTPROC_FLAGS_SAME_CONTRACT))
1048	rtSolarisContractPostForkParent(templateFd, pid);
1049	#endif /* RT_OS_SOLARIS */
1050	if (pid > 0)
1051	{
1052	/* For a detached process this happens in the temp process, so
1053	* it's not worth doing anything as this process must exit. */
1054	if (fFlags & RTPROC_FLAGS_DETACHED)
1055	_Exit(0);
1056	if (phProcess)
1057	*phProcess = pid;
1058	return rtProcPosixCreateReturn(VINF_SUCCESS, hEnvToUse, hEnv);
1059	}
1060	/* For a detached process this happens in the temp process, so
1061	* it's not worth doing anything as this process must exit. */
1062	if (fFlags & RTPROC_FLAGS_DETACHED)
1063	_Exit(124);
1064	return rtProcPosixCreateReturn(RTErrConvertFromErrno(errno), hEnvToUse, hEnv);
1065	}
1066
1067	return rtProcPosixCreateReturn(VERR_NOT_IMPLEMENTED, hEnvToUse, hEnv);
1068	}
1069
1070
1071	RTR3DECL(int) RTProcDaemonizeUsingFork(bool fNoChDir, bool fNoClose, const char *pszPidfile)
1072	{
1073	/*
1074	* Fork the child process in a new session and quit the parent.
1075	*
1076	* - fork once and create a new session (setsid). This will detach us
1077	* from the controlling tty meaning that we won't receive the SIGHUP
1078	* (or any other signal) sent to that session.
1079	* - The SIGHUP signal is ignored because the session/parent may throw
1080	* us one before we get to the setsid.
1081	* - When the parent exit(0) we will become an orphan and re-parented to
1082	* the init process.
1083	* - Because of the sometimes unexpected semantics of assigning the
1084	* controlling tty automagically when a session leader first opens a tty,
1085	* we will fork() once more to get rid of the session leadership role.
1086	*/
1087
1088	/* We start off by opening the pidfile, so that we can fail straight away
1089	* if it already exists. */
1090	int fdPidfile = -1;
1091	if (pszPidfile != NULL)
1092	{
1093	/* @note the exclusive create is not guaranteed on all file
1094	* systems (e.g. NFSv2) */
1095	if ((fdPidfile = open(pszPidfile, O_RDWR \| O_CREAT \| O_EXCL, 0644)) == -1)
1096	return RTErrConvertFromErrno(errno);
1097	}
1098
1099	/* Ignore SIGHUP straight away. */
1100	struct sigaction OldSigAct;
1101	struct sigaction SigAct;
1102	memset(&SigAct, 0, sizeof(SigAct));
1103	SigAct.sa_handler = SIG_IGN;
1104	int rcSigAct = sigaction(SIGHUP, &SigAct, &OldSigAct);
1105
1106	/* First fork, to become independent process. */
1107	pid_t pid = fork();
1108	if (pid == -1)
1109	{
1110	if (fdPidfile != -1)
1111	close(fdPidfile);
1112	return RTErrConvertFromErrno(errno);
1113	}
1114	if (pid != 0)
1115	{
1116	/* Parent exits, no longer necessary. The child gets reparented
1117	* to the init process. */
1118	exit(0);
1119	}
1120
1121	/* Create new session, fix up the standard file descriptors and the
1122	* current working directory. */
1123	/** @todo r=klaus the webservice uses this function and assumes that the
1124	* contract id of the daemon is the same as that of the original process.
1125	* Whenever this code is changed this must still remain possible. */
1126	pid_t newpgid = setsid();
1127	int SavedErrno = errno;
1128	if (rcSigAct != -1)
1129	sigaction(SIGHUP, &OldSigAct, NULL);
1130	if (newpgid == -1)
1131	{
1132	if (fdPidfile != -1)
1133	close(fdPidfile);
1134	return RTErrConvertFromErrno(SavedErrno);
1135	}
1136
1137	if (!fNoClose)
1138	{
1139	/* Open stdin(0), stdout(1) and stderr(2) as /dev/null. */
1140	int fd = open("/dev/null", O_RDWR);
1141	if (fd == -1) /* paranoia */
1142	{
1143	close(STDIN_FILENO);
1144	close(STDOUT_FILENO);
1145	close(STDERR_FILENO);
1146	fd = open("/dev/null", O_RDWR);
1147	}
1148	if (fd != -1)
1149	{
1150	dup2(fd, STDIN_FILENO);
1151	dup2(fd, STDOUT_FILENO);
1152	dup2(fd, STDERR_FILENO);
1153	if (fd > 2)
1154	close(fd);
1155	}
1156	}
1157
1158	if (!fNoChDir)
1159	{
1160	int rcIgnored = chdir("/");
1161	NOREF(rcIgnored);
1162	}
1163
1164	/* Second fork to lose session leader status. */
1165	pid = fork();
1166	if (pid == -1)
1167	{
1168	if (fdPidfile != -1)
1169	close(fdPidfile);
1170	return RTErrConvertFromErrno(errno);
1171	}
1172
1173	if (pid != 0)
1174	{
1175	/* Write the pid file, this is done in the parent, before exiting. */
1176	if (fdPidfile != -1)
1177	{
1178	char szBuf[256];
1179	size_t cbPid = RTStrPrintf(szBuf, sizeof(szBuf), "%d\n", pid);
1180	ssize_t cbIgnored = write(fdPidfile, szBuf, cbPid); NOREF(cbIgnored);
1181	close(fdPidfile);
1182	}
1183	exit(0);
1184	}
1185
1186	if (fdPidfile != -1)
1187	close(fdPidfile);
1188
1189	return VINF_SUCCESS;
1190	}
1191

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source: vbox/trunk/src/VBox/Runtime/r3/posix/process-creation-posix.cpp@ 77235

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