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 /* NFS server */ 30 31 #include <sys/param.h> 32 #include <sys/types.h> 33 #include <errno.h> 34 #include <stdio.h> 35 #include <stdio_ext.h> 36 #include <stdlib.h> 37 #include <signal.h> 38 #include <unistd.h> 39 #include <sys/wait.h> 40 #include <sys/stat.h> 41 #include <fcntl.h> 42 #include <libscf.h> 43 44 /* 45 * The parent never returns from this function. It sits 46 * and waits for the child to send status on whether it 47 * loaded or not. 48 * 49 * We do not close down the standard file descriptors until 50 * we know the child is going to run. 51 */ 52 int 53 daemonize_init(void) 54 { 55 int status, pfds[2]; 56 sigset_t set, oset; 57 pid_t pid; 58 59 /* 60 * Block all signals prior to the fork and leave them blocked in the 61 * parent so we don't get in a situation where the parent gets SIGINT 62 * and returns non-zero exit status and the child is actually running. 63 * In the child, restore the signal mask once we've done our setsid(). 64 */ 65 (void) sigfillset(&set); 66 (void) sigdelset(&set, SIGABRT); 67 (void) sigprocmask(SIG_BLOCK, &set, &oset); 68 69 /* 70 * We need to do this before we open the pipe - it makes things 71 * easier in the long run. 72 */ 73 closefrom(STDERR_FILENO + 1); 74 75 if (pipe(pfds) == -1) { 76 fprintf(stderr, "failed to create pipe for daemonize"); 77 exit(SMF_EXIT_ERR_FATAL); 78 } 79 80 if ((pid = fork()) == -1) { 81 fprintf(stderr, "failed to fork into background"); 82 exit(SMF_EXIT_ERR_FATAL); 83 } 84 85 if (pid != 0) { 86 (void) close(pfds[1]); 87 88 if (read(pfds[0], &status, sizeof (status)) == sizeof (status)) 89 exit(status); 90 91 if (waitpid(pid, &status, 0) == pid && WIFEXITED(status)) 92 exit(WEXITSTATUS(status)); 93 94 exit(SMF_EXIT_ERR_FATAL); 95 } 96 97 /* 98 * All child from here on... 99 */ 100 (void) setsid(); 101 (void) sigprocmask(SIG_SETMASK, &oset, NULL); 102 (void) close(pfds[0]); 103 104 return (pfds[1]); 105 } 106 107 /* 108 * We are only a daemon if the file descriptor is valid. 109 */ 110 void 111 daemonize_fini(int fd) 112 { 113 int status = 0; 114 115 if (fd != -1) { 116 (void) write(fd, &status, sizeof (status)); 117 118 (void) close(fd); 119 120 if ((fd = open("/dev/null", O_RDWR)) >= 0) { 121 (void) fcntl(fd, F_DUP2FD, STDIN_FILENO); 122 (void) fcntl(fd, F_DUP2FD, STDOUT_FILENO); 123 (void) fcntl(fd, F_DUP2FD, STDERR_FILENO); 124 (void) close(fd); 125 } 126 } 127 } 128