/* $NetBSD: amd.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $ */ /* * Copyright (c) 1997-2014 Erez Zadok * Copyright (c) 1989 Jan-Simon Pendry * Copyright (c) 1989 Imperial College of Science, Technology & Medicine * Copyright (c) 1989 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Jan-Simon Pendry at Imperial College, London. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * * File: am-utils/amd/amd.c * */ /* * Automounter */ #ifdef HAVE_CONFIG_H # include #endif /* HAVE_CONFIG_H */ #include #include struct amu_global_options gopt; /* where global options are stored */ char pid_fsname[SIZEOF_PID_FSNAME]; /* "kiska.southseas.nz:(pid%d)" */ char *hostdomain = "unknown.domain"; #define SIZEOF_HOSTD (2 * MAXHOSTNAMELEN + 1) /* Host+domain */ char hostd[SIZEOF_HOSTD]; /* Host+domain */ char *endian = ARCH_ENDIAN; /* Big or Little endian */ char *cpu = HOST_CPU; /* CPU type */ char *PrimNetName; /* name of primary network */ char *PrimNetNum; /* number of primary network */ int immediate_abort; /* Should close-down unmounts be retried */ int orig_umask = 022; int select_intr_valid; jmp_buf select_intr; struct amd_stats amd_stats; /* Server statistics */ struct in_addr myipaddr; /* (An) IP address of this host */ time_t do_mapc_reload = 0; /* mapc_reload() call required? */ #ifdef HAVE_FS_AUTOFS int amd_use_autofs = 0; #endif /* HAVE_FS_AUTOFS */ #ifdef HAVE_SIGACTION sigset_t masked_sigs; #endif /* HAVE_SIGACTION */ /* * Signal handler: * SIGINT - tells amd to do a full shutdown, including unmounting all * filesystem. * SIGTERM - tells amd to shutdown now. Just unmounts the automount nodes. */ static RETSIGTYPE sigterm(int sig) { #ifdef REINSTALL_SIGNAL_HANDLER signal(sig, sigterm); #endif /* REINSTALL_SIGNAL_HANDLER */ switch (sig) { case SIGINT: immediate_abort = 15; break; case SIGTERM: immediate_abort = -1; /* fall through... */ default: plog(XLOG_WARNING, "WARNING: automounter going down on signal %d", sig); break; } if (select_intr_valid) longjmp(select_intr, sig); } /* * Hook for cache reload. * When a SIGHUP arrives it schedules a call to mapc_reload */ static RETSIGTYPE sighup(int sig) { #ifdef REINSTALL_SIGNAL_HANDLER signal(sig, sighup); #endif /* REINSTALL_SIGNAL_HANDLER */ if (sig != SIGHUP) dlog("spurious call to sighup"); /* * Force a reload by zero'ing the timer */ if (amd_state == Run) do_mapc_reload = 0; } static RETSIGTYPE parent_exit(int sig) { /* * This signal handler is called during Amd initialization. The parent * forks a child to do all the hard automounting work, and waits for a * SIGQUIT signal from the child. When the parent gets the signal it's * supposed to call this handler and exit(3), thus completing the * daemonizing process. Alas, on some systems, especially Linux 2.4/2.6 * with Glibc, exit(3) doesn't always terminate the parent process. * Worse, the parent process now refuses to accept any more SIGQUIT * signals -- they are blocked. What's really annoying is that this * doesn't happen all the time, suggesting a race condition somewhere. * (This happens even if I change the logic to use another signal.) I * traced this to something which exit(3) does in addition to exiting the * process, probably some atexit() stuff or other side-effects related to * signal handling. Either way, since at this stage the parent process * just needs to terminate, I'm simply calling _exit(2). Note also that * the OpenGroup doesn't list exit(3) as a recommended "Base Interface" * but they do list _exit(2) as one. This fix seems to work reliably all * the time. -Erez (2/27/2005) */ _exit(0); } static int daemon_mode(void) { int bgpid; #ifdef HAVE_SIGACTION struct sigaction sa, osa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = parent_exit; sa.sa_flags = 0; sigemptyset(&(sa.sa_mask)); sigaddset(&(sa.sa_mask), SIGQUIT); sigaction(SIGQUIT, &sa, &osa); #else /* not HAVE_SIGACTION */ signal(SIGQUIT, parent_exit); #endif /* not HAVE_SIGACTION */ bgpid = background(); if (bgpid != 0) { /* * Now wait for the automount points to * complete. */ for (;;) pause(); /* should never reach here */ } #ifdef HAVE_SIGACTION sigaction(SIGQUIT, &osa, NULL); #else /* not HAVE_SIGACTION */ signal(SIGQUIT, SIG_DFL); #endif /* not HAVE_SIGACTION */ /* * Record our pid to make it easier to kill the correct amd. */ if (gopt.flags & CFM_PRINT_PID) { if (STREQ(gopt.pid_file, "/dev/stdout")) { printf("%ld\n", (long) am_mypid); /* flush stdout, just in case */ fflush(stdout); } else { FILE *f; mode_t prev_umask = umask(0022); /* set secure temporary umask */ f = fopen(gopt.pid_file, "w"); if (f) { fprintf(f, "%ld\n", (long) am_mypid); (void) fclose(f); } else { fprintf(stderr, "cannot open %s (errno=%d)\n", gopt.pid_file, errno); } umask(prev_umask); /* restore umask */ } } /* * Pretend we are in the foreground again */ foreground = 1; /* * Dissociate from the controlling terminal */ amu_release_controlling_tty(); return getppid(); } /* * Initialize global options structure. */ static void init_global_options(void) { #if defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) static struct utsname un; #endif /* defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) */ int i; memset(&gopt, 0, sizeof(struct amu_global_options)); /* name of current architecture */ gopt.arch = HOST_ARCH; /* automounter temp dir */ gopt.auto_dir = "/a"; /* toplevel attribute cache timeout */ gopt.auto_attrcache = 0; /* cluster name */ gopt.cluster = NULL; /* executable map timeout */ gopt.exec_map_timeout = AMFS_EXEC_MAP_TIMEOUT; /* * kernel architecture: this you must get from uname() if possible. */ #if defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) if (uname(&un) >= 0) gopt.karch = un.machine; else #endif /* defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) */ gopt.karch = HOST_ARCH; /* amd log file */ gopt.logfile = NULL; /* operating system name */ gopt.op_sys = HOST_OS_NAME; /* OS version */ gopt.op_sys_ver = HOST_OS_VERSION; /* full OS name and version */ gopt.op_sys_full = HOST_OS; /* OS version */ gopt.op_sys_vendor = HOST_VENDOR; /* pid file */ gopt.pid_file = "/dev/stdout"; /* local domain */ gopt.sub_domain = NULL; /* reset NFS (and toplvl) retransmit counter and retry interval */ for (i=0; i= sizeof(u_int)); assert(sizeof(int) >= 4); /* * Set processing status. */ amd_state = Start; /* * Determine program name */ if (argv[0]) { progname = strrchr(argv[0], '/'); if (progname && progname[1]) progname++; else progname = argv[0]; } if (!progname) progname = "amd"; am_set_progname(progname); /* * Initialize process id. This is kept * cached since it is used for generating * and using file handles. */ am_set_mypid(); /* * Get local machine name */ if (gethostname(hostname, sizeof(hostname)) < 0) { plog(XLOG_FATAL, "gethostname: %m"); going_down(1); return 1; } hostname[sizeof(hostname) - 1] = '\0'; /* * Check it makes sense */ if (!*hostname) { plog(XLOG_FATAL, "host name is not set"); going_down(1); return 1; } /* * Initialize global options structure. */ init_global_options(); /* * Partially initialize hostd[]. This * is completed in get_args(). */ if ((domdot = strchr(hostname, '.'))) { /* * Hostname already contains domainname. * Split out hostname and domainname * components */ *domdot++ = '\0'; hostdomain = domdot; } xstrlcpy(hostd, hostname, sizeof(hostd)); am_set_hostname(hostname); /* * Setup signal handlers */ /* SIGINT: trap interrupts for shutdowns */ setup_sighandler(SIGINT, sigterm); /* SIGTERM: trap terminate so we can shutdown cleanly (some chance) */ setup_sighandler(SIGTERM, sigterm); /* SIGHUP: hangups tell us to reload the cache */ setup_sighandler(SIGHUP, sighup); /* * SIGCHLD: trap Death-of-a-child. These allow us to pick up the exit * status of backgrounded mounts. See "sched.c". */ setup_sighandler(SIGCHLD, sigchld); #ifdef HAVE_SIGACTION /* construct global "masked_sigs" used in nfs_start.c */ sigemptyset(&masked_sigs); sigaddset(&masked_sigs, SIGINT); sigaddset(&masked_sigs, SIGTERM); sigaddset(&masked_sigs, SIGHUP); sigaddset(&masked_sigs, SIGCHLD); #endif /* HAVE_SIGACTION */ /* * Fix-up any umask problems. Most systems default * to 002 which is not too convenient for our purposes */ orig_umask = umask(0); /* * Figure out primary network name */ getwire(&PrimNetName, &PrimNetNum); /* * Determine command-line arguments. * (Also initialize amd.conf parameters, maps, and more.) */ get_args(argc, argv); /* * Log version information. */ vertmp = get_version_string(); verstr = strtok(vertmp, "\n"); plog(XLOG_INFO, "AM-UTILS VERSION INFORMATION:"); while (verstr) { plog(XLOG_INFO, "%s", verstr); verstr = strtok(NULL, "\n"); } XFREE(vertmp); /* * Get our own IP address so that we can mount the automounter. We pass * localhost_address which could be used as the default localhost * name/address in amu_get_myaddress(). */ amu_get_myaddress(&myipaddr, gopt.localhost_address); plog(XLOG_INFO, "My ip addr is %s", inet_ntoa(myipaddr)); /* avoid hanging on other NFS servers if started elsewhere */ if (chdir("/") < 0) plog(XLOG_INFO, "cannot chdir to /: %m"); /* * Now check we are root. */ if (geteuid() != 0) { plog(XLOG_FATAL, "Must be root to mount filesystems (euid = %ld)", (long) geteuid()); going_down(1); return 1; } #ifdef HAVE_MAP_NIS /* * If the domain was specified then bind it here * to circumvent any default bindings that may * be done in the C library. */ if (gopt.nis_domain && yp_bind(gopt.nis_domain)) { plog(XLOG_FATAL, "Can't bind to NIS domain \"%s\"", gopt.nis_domain); going_down(1); return 1; } #endif /* HAVE_MAP_NIS */ if (amuDebug(D_DAEMON)) ppid = daemon_mode(); /* * Lock process text and data segment in memory. */ if (gopt.flags & CFM_PROCESS_LOCK) { do_memory_locking(); } do_mapc_reload = clocktime(NULL) + gopt.map_reload_interval; /* * Register automounter with system. */ error = mount_automounter(ppid); if (error && ppid) kill(ppid, SIGALRM); #ifdef HAVE_FS_AUTOFS /* * XXX this should be part of going_down(), but I can't move it there * because it would be calling non-library code from the library... ugh */ if (amd_use_autofs) destroy_autofs_service(); #endif /* HAVE_FS_AUTOFS */ going_down(error); abort(); return 1; /* should never get here */ }