1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* LINTLIBRARY */ 27 /* PROTOLIB1 */ 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 /* NFS server */ 32 33 #include <sys/param.h> 34 #include <sys/types.h> 35 #include <errno.h> 36 #include <stdio.h> 37 #include <stdio_ext.h> 38 #include <stdlib.h> 39 #include <signal.h> 40 #include <unistd.h> 41 #include <sys/wait.h> 42 #include <sys/stat.h> 43 #include <fcntl.h> 44 #include <libscf.h> 45 46 /* 47 * The parent never returns from this function. It sits 48 * and waits for the child to send status on whether it 49 * loaded or not. 50 * 51 * We do not close down the standard file descriptors until 52 * we know the child is going to run. 53 */ 54 int 55 daemonize_init(void) 56 { 57 int status, pfds[2]; 58 sigset_t set, oset; 59 pid_t pid; 60 61 /* 62 * Block all signals prior to the fork and leave them blocked in the 63 * parent so we don't get in a situation where the parent gets SIGINT 64 * and returns non-zero exit status and the child is actually running. 65 * In the child, restore the signal mask once we've done our setsid(). 66 */ 67 (void) sigfillset(&set); 68 (void) sigdelset(&set, SIGABRT); 69 (void) sigprocmask(SIG_BLOCK, &set, &oset); 70 71 /* 72 * We need to do this before we open the pipe - it makes things 73 * easier in the long run. 74 */ 75 closefrom(STDERR_FILENO + 1); 76 77 if (pipe(pfds) == -1) { 78 fprintf(stderr, "failed to create pipe for daemonize"); 79 exit(SMF_EXIT_ERR_FATAL); 80 } 81 82 if ((pid = fork()) == -1) { 83 fprintf(stderr, "failed to fork into background"); 84 exit(SMF_EXIT_ERR_FATAL); 85 } 86 87 if (pid != 0) { 88 (void) close(pfds[1]); 89 90 if (read(pfds[0], &status, sizeof (status)) == sizeof (status)) 91 exit(status); 92 93 if (waitpid(pid, &status, 0) == pid && WIFEXITED(status)) 94 exit(WEXITSTATUS(status)); 95 96 exit(SMF_EXIT_ERR_FATAL); 97 } 98 99 /* 100 * All child from here on... 101 */ 102 (void) setsid(); 103 (void) sigprocmask(SIG_SETMASK, &oset, NULL); 104 (void) close(pfds[0]); 105 106 return (pfds[1]); 107 } 108 109 /* 110 * We are only a daemon if the file descriptor is valid. 111 */ 112 void 113 daemonize_fini(int fd) 114 { 115 int status = 0; 116 117 if (fd != -1) { 118 (void) write(fd, &status, sizeof (status)); 119 120 (void) close(fd); 121 122 if ((fd = open("/dev/null", O_RDWR)) >= 0) { 123 (void) fcntl(fd, F_DUP2FD, STDIN_FILENO); 124 (void) fcntl(fd, F_DUP2FD, STDOUT_FILENO); 125 (void) fcntl(fd, F_DUP2FD, STDERR_FILENO); 126 (void) close(fd); 127 } 128 } 129 } 130