| 1 | /** $Id: VBoxGuestR3LibDaemonize.cpp 93115 2022-01-01 11:31:46Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * VBoxGuestR3Lib - Ring-3 Support Library for VirtualBox guest additions, daemonize a process.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2007-2022 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 | #if defined(RT_OS_OS2)
|
|---|
| 32 | # define INCL_BASE
|
|---|
| 33 | # define INCL_ERRORS
|
|---|
| 34 | # include <os2.h>
|
|---|
| 35 |
|
|---|
| 36 | # include <iprt/alloca.h>
|
|---|
| 37 | # include <iprt/string.h>
|
|---|
| 38 |
|
|---|
| 39 | #elif defined(RT_OS_WINDOWS)
|
|---|
| 40 | # error "PORTME"
|
|---|
| 41 |
|
|---|
| 42 | #else /* the unices */
|
|---|
| 43 | # include <sys/types.h>
|
|---|
| 44 | # include <sys/stat.h>
|
|---|
| 45 | # include <sys/wait.h>
|
|---|
| 46 | # include <stdio.h>
|
|---|
| 47 | # include <fcntl.h>
|
|---|
| 48 | # include <stdlib.h>
|
|---|
| 49 | # include <unistd.h>
|
|---|
| 50 | # include <signal.h>
|
|---|
| 51 | # include <errno.h>
|
|---|
| 52 | #endif
|
|---|
| 53 |
|
|---|
| 54 | #include <iprt/process.h>
|
|---|
| 55 | #include <iprt/string.h>
|
|---|
| 56 | #include "VBoxGuestR3LibInternal.h"
|
|---|
| 57 |
|
|---|
| 58 |
|
|---|
| 59 | /**
|
|---|
| 60 | * Daemonize the process for running in the background.
|
|---|
| 61 | *
|
|---|
| 62 | * This is supposed to do the same job as the BSD daemon() call.
|
|---|
| 63 | *
|
|---|
| 64 | * @returns 0 on success
|
|---|
| 65 | *
|
|---|
| 66 | * @param fNoChDir Pass false to change working directory to root.
|
|---|
| 67 | * @param fNoClose Pass false to redirect standard file streams to /dev/null.
|
|---|
| 68 | * @param fRespawn Restart the daemonised process after five seconds if it
|
|---|
| 69 | * terminates abnormally.
|
|---|
| 70 | * @param pcRespawn Where to store a count of how often we have respawned,
|
|---|
| 71 | * intended for avoiding error spamming. Optional.
|
|---|
| 72 | *
|
|---|
| 73 | * @todo Use RTProcDaemonize instead of this.
|
|---|
| 74 | * @todo Implement fRespawn on OS/2.
|
|---|
| 75 | * @todo Make the respawn interval configurable. But not until someone
|
|---|
| 76 | * actually needs that.
|
|---|
| 77 | */
|
|---|
| 78 | VBGLR3DECL(int) VbglR3Daemonize(bool fNoChDir, bool fNoClose, bool fRespawn, unsigned *pcRespawn)
|
|---|
| 79 | {
|
|---|
| 80 | #if defined(RT_OS_OS2)
|
|---|
| 81 | PPIB pPib;
|
|---|
| 82 | PTIB pTib;
|
|---|
| 83 | DosGetInfoBlocks(&pTib, &pPib);
|
|---|
| 84 |
|
|---|
| 85 | AssertRelease(!fRespawn);
|
|---|
| 86 | /* Get the full path to the executable. */
|
|---|
| 87 | char szExe[CCHMAXPATH];
|
|---|
| 88 | APIRET rc = DosQueryModuleName(pPib->pib_hmte, sizeof(szExe), szExe);
|
|---|
| 89 | if (rc)
|
|---|
| 90 | return RTErrConvertFromOS2(rc);
|
|---|
| 91 |
|
|---|
| 92 | /* calc the length of the command line. */
|
|---|
| 93 | char *pch = pPib->pib_pchcmd;
|
|---|
| 94 | size_t cch0 = strlen(pch);
|
|---|
| 95 | pch += cch0 + 1;
|
|---|
| 96 | size_t cch1 = strlen(pch);
|
|---|
| 97 | pch += cch1 + 1;
|
|---|
| 98 | char *pchArgs;
|
|---|
| 99 | if (cch1 && *pch)
|
|---|
| 100 | {
|
|---|
| 101 | do pch = strchr(pch, '\0') + 1;
|
|---|
| 102 | while (*pch);
|
|---|
| 103 |
|
|---|
| 104 | size_t cchTotal = pch - pPib->pib_pchcmd;
|
|---|
| 105 | pchArgs = (char *)alloca(cchTotal + sizeof("--daemonized\0\0"));
|
|---|
| 106 | memcpy(pchArgs, pPib->pib_pchcmd, cchTotal - 1);
|
|---|
| 107 | memcpy(pchArgs + cchTotal - 1, "--daemonized\0\0", sizeof("--daemonized\0\0"));
|
|---|
| 108 | }
|
|---|
| 109 | else
|
|---|
| 110 | {
|
|---|
| 111 | size_t cchTotal = pch - pPib->pib_pchcmd + 1;
|
|---|
| 112 | pchArgs = (char *)alloca(cchTotal + sizeof(" --daemonized "));
|
|---|
| 113 | memcpy(pchArgs, pPib->pib_pchcmd, cch0 + 1);
|
|---|
| 114 | pch = pchArgs + cch0 + 1;
|
|---|
| 115 | memcpy(pch, " --daemonized ", sizeof(" --daemonized ") - 1);
|
|---|
| 116 | pch += sizeof(" --daemonized ") - 1;
|
|---|
| 117 | if (cch1)
|
|---|
| 118 | memcpy(pch, pPib->pib_pchcmd + cch0 + 1, cch1 + 2);
|
|---|
| 119 | else
|
|---|
| 120 | pch[0] = pch[1] = '\0';
|
|---|
| 121 | }
|
|---|
| 122 |
|
|---|
| 123 | /* spawn a detach process */
|
|---|
| 124 | char szObj[128];
|
|---|
| 125 | RESULTCODES ResCodes = { 0, 0 };
|
|---|
| 126 | szObj[0] = '\0';
|
|---|
| 127 | rc = DosExecPgm(szObj, sizeof(szObj), EXEC_BACKGROUND, (PCSZ)pchArgs, NULL, &ResCodes, (PCSZ)szExe);
|
|---|
| 128 | if (rc)
|
|---|
| 129 | {
|
|---|
| 130 | /** @todo Change this to some standard log/print error?? */
|
|---|
| 131 | /* VBoxServiceError("DosExecPgm failed with rc=%d and szObj='%s'\n", rc, szObj); */
|
|---|
| 132 | return RTErrConvertFromOS2(rc);
|
|---|
| 133 | }
|
|---|
| 134 | DosExit(EXIT_PROCESS, 0);
|
|---|
| 135 | return VERR_GENERAL_FAILURE;
|
|---|
| 136 |
|
|---|
| 137 | #elif defined(RT_OS_WINDOWS)
|
|---|
| 138 | # error "PORTME"
|
|---|
| 139 |
|
|---|
| 140 | #else /* the unices */
|
|---|
| 141 | /*
|
|---|
| 142 | * Fork the child process in a new session and quit the parent.
|
|---|
| 143 | *
|
|---|
| 144 | * - fork once and create a new session (setsid). This will detach us
|
|---|
| 145 | * from the controlling tty meaning that we won't receive the SIGHUP
|
|---|
| 146 | * (or any other signal) sent to that session.
|
|---|
| 147 | * - The SIGHUP signal is ignored because the session/parent may throw
|
|---|
| 148 | * us one before we get to the setsid.
|
|---|
| 149 | * - When the parent exit(0) we will become an orphan and re-parented to
|
|---|
| 150 | * the init process.
|
|---|
| 151 | * - Because of the Linux / System V semantics of assigning the controlling
|
|---|
| 152 | * tty automagically when a session leader first opens a tty, we will
|
|---|
| 153 | * fork() once more on Linux to get rid of the session leadership role.
|
|---|
| 154 | */
|
|---|
| 155 |
|
|---|
| 156 | struct sigaction OldSigAct;
|
|---|
| 157 | struct sigaction SigAct;
|
|---|
| 158 | RT_ZERO(SigAct);
|
|---|
| 159 | SigAct.sa_handler = SIG_IGN;
|
|---|
| 160 | int rcSigAct = sigaction(SIGHUP, &SigAct, &OldSigAct);
|
|---|
| 161 |
|
|---|
| 162 | pid_t pid = fork();
|
|---|
| 163 | if (pid == -1)
|
|---|
| 164 | return RTErrConvertFromErrno(errno);
|
|---|
| 165 | if (pid != 0)
|
|---|
| 166 | exit(0);
|
|---|
| 167 |
|
|---|
| 168 | /*
|
|---|
| 169 | * The orphaned child becomes is reparented to the init process.
|
|---|
| 170 | * We create a new session for it (setsid), point the standard
|
|---|
| 171 | * file descriptors to /dev/null, and change to the root directory.
|
|---|
| 172 | */
|
|---|
| 173 | pid_t newpgid = setsid();
|
|---|
| 174 | int SavedErrno = errno;
|
|---|
| 175 | if (rcSigAct != -1)
|
|---|
| 176 | sigaction(SIGHUP, &OldSigAct, NULL);
|
|---|
| 177 | if (newpgid == -1)
|
|---|
| 178 | return RTErrConvertFromErrno(SavedErrno);
|
|---|
| 179 |
|
|---|
| 180 | if (!fNoClose)
|
|---|
| 181 | {
|
|---|
| 182 | /* Open stdin(0), stdout(1) and stderr(2) as /dev/null. */
|
|---|
| 183 | int fd = open("/dev/null", O_RDWR);
|
|---|
| 184 | if (fd == -1) /* paranoia */
|
|---|
| 185 | {
|
|---|
| 186 | close(STDIN_FILENO);
|
|---|
| 187 | close(STDOUT_FILENO);
|
|---|
| 188 | close(STDERR_FILENO);
|
|---|
| 189 | fd = open("/dev/null", O_RDWR);
|
|---|
| 190 | }
|
|---|
| 191 | if (fd != -1)
|
|---|
| 192 | {
|
|---|
| 193 | dup2(fd, STDIN_FILENO);
|
|---|
| 194 | dup2(fd, STDOUT_FILENO);
|
|---|
| 195 | dup2(fd, STDERR_FILENO);
|
|---|
| 196 | if (fd > 2)
|
|---|
| 197 | close(fd);
|
|---|
| 198 | }
|
|---|
| 199 | }
|
|---|
| 200 |
|
|---|
| 201 | if (!fNoChDir)
|
|---|
| 202 | {
|
|---|
| 203 | int rcShutUpGcc = chdir("/");
|
|---|
| 204 | RT_NOREF_PV(rcShutUpGcc);
|
|---|
| 205 | }
|
|---|
| 206 |
|
|---|
| 207 | /*
|
|---|
| 208 | * Change the umask - this is non-standard daemon() behavior.
|
|---|
| 209 | */
|
|---|
| 210 | umask(027);
|
|---|
| 211 |
|
|---|
| 212 | # ifdef RT_OS_LINUX
|
|---|
| 213 | /*
|
|---|
| 214 | * And fork again to lose session leader status (non-standard daemon()
|
|---|
| 215 | * behaviour).
|
|---|
| 216 | */
|
|---|
| 217 | pid = fork();
|
|---|
| 218 | if (pid == -1)
|
|---|
| 219 | return RTErrConvertFromErrno(errno);
|
|---|
| 220 | if (pid != 0)
|
|---|
| 221 | exit(0);
|
|---|
| 222 | # endif /* RT_OS_LINUX */
|
|---|
| 223 |
|
|---|
| 224 | if (fRespawn)
|
|---|
| 225 | {
|
|---|
| 226 | /* We implement re-spawning as a third fork(), with the parent process
|
|---|
| 227 | * monitoring the child and re-starting it after a delay if it exits
|
|---|
| 228 | * abnormally. */
|
|---|
| 229 | unsigned cRespawn = 0;
|
|---|
| 230 | for (;;)
|
|---|
| 231 | {
|
|---|
| 232 | int iStatus, rcWait;
|
|---|
| 233 |
|
|---|
| 234 | if (pcRespawn != NULL)
|
|---|
| 235 | *pcRespawn = cRespawn;
|
|---|
| 236 | pid = fork();
|
|---|
| 237 | if (pid == -1)
|
|---|
| 238 | return RTErrConvertFromErrno(errno);
|
|---|
| 239 | if (pid == 0)
|
|---|
| 240 | return VINF_SUCCESS;
|
|---|
| 241 | do
|
|---|
| 242 | rcWait = waitpid(pid, &iStatus, 0);
|
|---|
| 243 | while (rcWait == -1 && errno == EINTR);
|
|---|
| 244 | if (rcWait == -1)
|
|---|
| 245 | exit(1);
|
|---|
| 246 | if (WIFEXITED(iStatus) && WEXITSTATUS(iStatus) == 0)
|
|---|
| 247 | exit(0);
|
|---|
| 248 | sleep(5);
|
|---|
| 249 | ++cRespawn;
|
|---|
| 250 | }
|
|---|
| 251 | }
|
|---|
| 252 | return VINF_SUCCESS;
|
|---|
| 253 | #endif
|
|---|
| 254 | }
|
|---|
