1 /*- 2 * Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Berkeley Software Design Inc's name may not be used to endorse or 13 * promote products derived from this software without specific prior 14 * written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 36 #include <err.h> 37 #include <errno.h> 38 #include <pwd.h> 39 #include <grp.h> 40 #include <libutil.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <unistd.h> 44 45 static void restrict_process(const char *, const char *); 46 static void usage(void); 47 48 int 49 main(int argc, char *argv[]) 50 { 51 struct pidfh *pfh = NULL; 52 int ch, nochdir, noclose, errcode; 53 const char *pidfile, *user, *group; 54 pid_t otherpid; 55 56 nochdir = noclose = 1; 57 pidfile = user = group = NULL; 58 while ((ch = getopt(argc, argv, "-cfg:p:u:")) != -1) { 59 switch (ch) { 60 case 'c': 61 nochdir = 0; 62 break; 63 case 'f': 64 noclose = 0; 65 break; 66 case 'u': 67 user = optarg; 68 break; 69 case 'g': 70 group = optarg; 71 break; 72 case 'p': 73 pidfile = optarg; 74 break; 75 default: 76 usage(); 77 } 78 } 79 argc -= optind; 80 argv += optind; 81 82 if (argc == 0) 83 usage(); 84 85 if (user || group) { 86 if (getuid() != 0) 87 errx(1, "only root user is allowed to chroot " 88 "and change UID/GID"); 89 restrict_process(user, group); 90 } 91 92 /* 93 * Try to open the pidfile before calling daemon(3), 94 * to be able to report the error intelligently 95 */ 96 if (pidfile) { 97 pfh = pidfile_open(pidfile, 0600, &otherpid); 98 if (pfh == NULL) { 99 if (errno == EEXIST) { 100 errx(3, "process already running, pid: %d", 101 otherpid); 102 } 103 err(2, "pidfile ``%s''", pidfile); 104 } 105 } 106 107 if (daemon(nochdir, noclose) == -1) 108 err(1, NULL); 109 110 /* Now that we are the child, write out the pid */ 111 if (pidfile) 112 pidfile_write(pfh); 113 114 execvp(argv[0], argv); 115 116 /* 117 * execvp() failed -- unlink pidfile if any, and 118 * report the error 119 */ 120 errcode = errno; /* Preserve errcode -- unlink may reset it */ 121 if (pidfile) 122 pidfile_remove(pfh); 123 124 /* The child is now running, so the exit status doesn't matter. */ 125 errc(1, errcode, "%s", argv[0]); 126 } 127 128 static void 129 restrict_process(const char *user, const char *group) 130 { 131 struct group *gr = NULL; 132 struct passwd *pw = NULL; 133 errno = 0; 134 135 if (group != NULL) { 136 if (initgroups(user, gr->gr_gid) == -1) 137 errx(1, "User not in group list"); 138 if ((gr = getgrnam(group)) == NULL) 139 errx(1, "Group %s does not exist", group); 140 if (setgid(gr->gr_gid) == -1) 141 err(1, "%s", group); 142 } 143 144 if (user != NULL) { 145 if ((pw = getpwnam(user)) == NULL) 146 errx(1, "User %s does not exist", user); 147 if (setuid(pw->pw_uid) == -1) 148 err(1, "%s", user); 149 } 150 } 151 152 static void 153 usage(void) 154 { 155 (void)fprintf(stderr, 156 "usage: daemon [-cf] [-g group] [-p pidfile] [-u user] command " 157 "arguments ...\n"); 158 exit(1); 159 } 160