amd.c revision 310490 
1/*
2 * Copyright (c) 1997-2014 Erez Zadok
3 * Copyright (c) 1989 Jan-Simon Pendry
4 * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1989 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *
36 * $Id: amd.c,v 1.8.2.6 2004/01/06 03:15:16 ezk Exp $
37 * File: am-utils/amd/amd.c
38 *
39 */
40
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: stable/10/contrib/amd/amd/amd.c 310490 2016-12-23 22:42:14Z cy $");
43
44/*
45 * Automounter
46 */
47
48#ifdef HAVE_CONFIG_H
49# include <config.h>
50#endif /* HAVE_CONFIG_H */
51#include <am_defs.h>
52#include <amd.h>
53
54struct amu_global_options gopt;	/* where global options are stored */
55
56char pid_fsname[SIZEOF_PID_FSNAME]; /* "kiska.southseas.nz:(pid%d)" */
57char *hostdomain = "unknown.domain";
58#define SIZEOF_HOSTD (2 * MAXHOSTNAMELEN + 1)	/* Host+domain */
59char hostd[SIZEOF_HOSTD];	/* Host+domain */
60char *endian = ARCH_ENDIAN;	/* Big or Little endian */
61char *cpu = HOST_CPU;		/* CPU type */
62char *PrimNetName;		/* name of primary network */
63char *PrimNetNum;		/* number of primary network */
64
65int immediate_abort;		/* Should close-down unmounts be retried */
66int orig_umask = 022;
67int select_intr_valid;
68
69jmp_buf select_intr;
70struct amd_stats amd_stats;	/* Server statistics */
71struct in_addr myipaddr;	/* (An) IP address of this host */
72time_t do_mapc_reload = 0;	/* mapc_reload() call required? */
73
74#ifdef HAVE_FS_AUTOFS
75int amd_use_autofs = 0;
76#endif /* HAVE_FS_AUTOFS */
77
78#ifdef HAVE_SIGACTION
79sigset_t masked_sigs;
80#endif /* HAVE_SIGACTION */
81
82
83/*
84 * Signal handler:
85 * SIGINT - tells amd to do a full shutdown, including unmounting all
86 *       filesystem.
87 * SIGTERM - tells amd to shutdown now.  Just unmounts the automount nodes.
88 */
89static RETSIGTYPE
90sigterm(int sig)
91{
92#ifdef REINSTALL_SIGNAL_HANDLER
93  signal(sig, sigterm);
94#endif /* REINSTALL_SIGNAL_HANDLER */
95
96  switch (sig) {
97  case SIGINT:
98    immediate_abort = 15;
99    break;
100
101  case SIGTERM:
102    immediate_abort = -1;
103    /* fall through... */
104
105  default:
106    plog(XLOG_WARNING, "WARNING: automounter going down on signal %d", sig);
107    break;
108  }
109  if (select_intr_valid)
110    longjmp(select_intr, sig);
111}
112
113
114/*
115 * Hook for cache reload.
116 * When a SIGHUP arrives it schedules a call to mapc_reload
117 */
118static RETSIGTYPE
119sighup(int sig)
120{
121#ifdef REINSTALL_SIGNAL_HANDLER
122  signal(sig, sighup);
123#endif /* REINSTALL_SIGNAL_HANDLER */
124
125  if (sig != SIGHUP)
126    dlog("spurious call to sighup");
127  /*
128   * Force a reload by zero'ing the timer
129   */
130  if (amd_state == Run)
131    do_mapc_reload = 0;
132}
133
134
135static RETSIGTYPE
136parent_exit(int sig)
137{
138  /*
139   * This signal handler is called during Amd initialization.  The parent
140   * forks a child to do all the hard automounting work, and waits for a
141   * SIGQUIT signal from the child.  When the parent gets the signal it's
142   * supposed to call this handler and exit(3), thus completing the
143   * daemonizing process.  Alas, on some systems, especially Linux 2.4/2.6
144   * with Glibc, exit(3) doesn't always terminate the parent process.
145   * Worse, the parent process now refuses to accept any more SIGQUIT
146   * signals -- they are blocked.  What's really annoying is that this
147   * doesn't happen all the time, suggesting a race condition somewhere.
148   * (This happens even if I change the logic to use another signal.)  I
149   * traced this to something which exit(3) does in addition to exiting the
150   * process, probably some atexit() stuff or other side-effects related to
151   * signal handling.  Either way, since at this stage the parent process
152   * just needs to terminate, I'm simply calling _exit(2).  Note also that
153   * the OpenGroup doesn't list exit(3) as a recommended "Base Interface"
154   * but they do list _exit(2) as one.  This fix seems to work reliably all
155   * the time. -Erez (2/27/2005)
156   */
157  _exit(0);
158}
159
160
161static int
162daemon_mode(void)
163{
164  int bgpid;
165
166#ifdef HAVE_SIGACTION
167  struct sigaction sa, osa;
168
169  memset(&sa, 0, sizeof(sa));
170  sa.sa_handler = parent_exit;
171  sa.sa_flags = 0;
172  sigemptyset(&(sa.sa_mask));
173  sigaddset(&(sa.sa_mask), SIGQUIT);
174  sigaction(SIGQUIT, &sa, &osa);
175#else /* not HAVE_SIGACTION */
176  signal(SIGQUIT, parent_exit);
177#endif /* not HAVE_SIGACTION */
178
179  bgpid = background();
180
181  if (bgpid != 0) {
182    /*
183     * Now wait for the automount points to
184     * complete.
185     */
186    for (;;)
187      pause();
188    /* should never reach here */
189  }
190#ifdef HAVE_SIGACTION
191  sigaction(SIGQUIT, &osa, NULL);
192#else /* not HAVE_SIGACTION */
193  signal(SIGQUIT, SIG_DFL);
194#endif /* not HAVE_SIGACTION */
195
196  /*
197   * Record our pid to make it easier to kill the correct amd.
198   */
199  if (gopt.flags & CFM_PRINT_PID) {
200    if (STREQ(gopt.pid_file, "/dev/stdout")) {
201      printf("%ld\n", (long) am_mypid);
202      /* flush stdout, just in case */
203      fflush(stdout);
204    } else {
205      FILE *f;
206      mode_t prev_umask = umask(0022); /* set secure temporary umask */
207
208      f = fopen(gopt.pid_file, "w");
209      if (f) {
210	fprintf(f, "%ld\n", (long) am_mypid);
211	(void) fclose(f);
212      } else {
213	fprintf(stderr, "cannot open %s (errno=%d)\n", gopt.pid_file, errno);
214      }
215      umask(prev_umask);	/* restore umask */
216    }
217  }
218
219  /*
220   * Pretend we are in the foreground again
221   */
222  foreground = 1;
223
224  /*
225   * Dissociate from the controlling terminal
226   */
227  amu_release_controlling_tty();
228
229  return getppid();
230}
231
232
233/*
234 * Initialize global options structure.
235 */
236static void
237init_global_options(void)
238{
239#if defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME)
240  static struct utsname un;
241#endif /* defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) */
242  int i;
243
244  memset(&gopt, 0, sizeof(struct amu_global_options));
245
246  /* name of current architecture */
247  gopt.arch = HOST_ARCH;
248
249  /* automounter temp dir */
250  gopt.auto_dir = "/.amd_mnt";
251
252  /* toplevel attribute cache timeout */
253  gopt.auto_attrcache = 0;
254
255  /* cluster name */
256  gopt.cluster = NULL;
257
258  /* executable map timeout */
259  gopt.exec_map_timeout = AMFS_EXEC_MAP_TIMEOUT;
260
261  /*
262   * kernel architecture: this you must get from uname() if possible.
263   */
264#if defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME)
265  if (uname(&un) >= 0)
266    gopt.karch = un.machine;
267  else
268#endif /* defined(HAVE_SYS_UTSNAME_H) && defined(HAVE_UNAME) */
269    gopt.karch = HOST_ARCH;
270
271  /* amd log file */
272  gopt.logfile = NULL;
273
274  /* operating system name */
275  gopt.op_sys = HOST_OS_NAME;
276
277  /* OS version */
278  gopt.op_sys_ver = HOST_OS_VERSION;
279
280  /* full OS name and version */
281  gopt.op_sys_full = HOST_OS;
282
283  /* OS version */
284  gopt.op_sys_vendor = HOST_VENDOR;
285
286  /* pid file */
287  gopt.pid_file = "/dev/stdout";
288
289  /* local domain */
290  gopt.sub_domain = NULL;
291
292  /* reset NFS (and toplvl) retransmit counter and retry interval */
293  for (i=0; i<AMU_TYPE_MAX; ++i) {
294    gopt.amfs_auto_retrans[i] = -1; /* -1 means "never set before" */
295    gopt.amfs_auto_timeo[i] = -1; /* -1 means "never set before" */
296  }
297
298  /* cache duration */
299  gopt.am_timeo = AM_TTL;
300
301  /* dismount interval */
302  gopt.am_timeo_w = AM_TTL_W;
303
304  /* map reload intervl */
305  gopt.map_reload_interval = ONE_HOUR;
306
307  /*
308   * various CFM_* flags that are on by default.
309   */
310  gopt.flags = CFM_DEFAULT_FLAGS;
311
312#ifdef HAVE_MAP_HESIOD
313  /* Hesiod rhs zone */
314  gopt.hesiod_base = "automount";
315#endif /* HAVE_MAP_HESIOD */
316
317#ifdef HAVE_MAP_LDAP
318  /* LDAP base */
319  gopt.ldap_base = NULL;
320
321  /* LDAP host ports */
322  gopt.ldap_hostports = NULL;
323
324  /* LDAP cache */
325  gopt.ldap_cache_seconds = 0;
326  gopt.ldap_cache_maxmem = 131072;
327
328  /* LDAP protocol version */
329  gopt.ldap_proto_version = 2;
330#endif /* HAVE_MAP_LDAP */
331
332#ifdef HAVE_MAP_NIS
333  /* YP domain name */
334  gopt.nis_domain = NULL;
335#endif /* HAVE_MAP_NIS */
336}
337
338
339/*
340 * Lock process text and data segment in memory (after forking the daemon)
341 */
342static void
343do_memory_locking(void)
344{
345#if defined(HAVE_PLOCK) || defined(HAVE_MLOCKALL)
346  int locked_ok = 0;
347#else /* not HAVE_PLOCK and not HAVE_MLOCKALL */
348  plog(XLOG_WARNING, "Process memory locking not supported by the OS");
349#endif /* not HAVE_PLOCK and not HAVE_MLOCKALL */
350#ifdef HAVE_PLOCK
351# ifdef _AIX
352  /*
353   * On AIX you must lower the stack size using ulimit() before calling
354   * plock.  Otherwise plock will reserve a lot of memory space based on
355   * your maximum stack size limit.  Since it is not easily possible to
356   * tell what should the limit be, I print a warning before calling
357   * plock().  See the manual pages for ulimit(1,3,4) on your AIX system.
358   */
359  plog(XLOG_WARNING, "AIX: may need to lower stack size using ulimit(3) before calling plock");
360# endif /* _AIX */
361  if (!locked_ok && plock(PROCLOCK) != 0)
362    plog(XLOG_WARNING, "Couldn't lock process pages in memory using plock(): %m");
363  else
364    locked_ok = 1;
365#endif /* HAVE_PLOCK */
366#ifdef HAVE_MLOCKALL
367  if (!locked_ok && mlockall(MCL_CURRENT|MCL_FUTURE) != 0)
368    plog(XLOG_WARNING, "Couldn't lock process pages in memory using mlockall(): %m");
369  else
370    locked_ok = 1;
371#endif /* HAVE_MLOCKALL */
372#if defined(HAVE_PLOCK) || defined(HAVE_MLOCKALL)
373  if (locked_ok)
374    plog(XLOG_INFO, "Locked process pages in memory");
375#endif /* HAVE_PLOCK || HAVE_MLOCKALL */
376
377#if defined(HAVE_MADVISE) && defined(MADV_PROTECT)
378    madvise(NULL, 0, MADV_PROTECT); /* may be redundant of the above worked out */
379#endif /* defined(HAVE_MADVISE) && defined(MADV_PROTECT) */
380}
381
382
383int
384main(int argc, char *argv[])
385{
386  char *domdot, *verstr, *vertmp;
387  int ppid = 0;
388  int error;
389  char *progname = NULL;		/* "amd" */
390  char hostname[MAXHOSTNAMELEN + 1] = "localhost"; /* Hostname */
391
392  /*
393   * Make sure some built-in assumptions are true before we start
394   */
395  assert(sizeof(nfscookie) >= sizeof(u_int));
396  assert(sizeof(int) >= 4);
397
398  /*
399   * Set processing status.
400   */
401  amd_state = Start;
402
403  /*
404   * Determine program name
405   */
406  if (argv[0]) {
407    progname = strrchr(argv[0], '/');
408    if (progname && progname[1])
409      progname++;
410    else
411      progname = argv[0];
412  }
413  if (!progname)
414    progname = "amd";
415  am_set_progname(progname);
416
417  /*
418   * Initialize process id.  This is kept
419   * cached since it is used for generating
420   * and using file handles.
421   */
422  am_set_mypid();
423
424  /*
425   * Get local machine name
426   */
427  if (gethostname(hostname, sizeof(hostname)) < 0) {
428    plog(XLOG_FATAL, "gethostname: %m");
429    going_down(1);
430    return 1;
431  }
432  hostname[sizeof(hostname) - 1] = '\0';
433
434  /*
435   * Check it makes sense
436   */
437  if (!*hostname) {
438    plog(XLOG_FATAL, "host name is not set");
439    going_down(1);
440    return 1;
441  }
442
443  /*
444   * Initialize global options structure.
445   */
446  init_global_options();
447
448  /*
449   * Partially initialize hostd[].  This
450   * is completed in get_args().
451   */
452  if ((domdot = strchr(hostname, '.'))) {
453    /*
454     * Hostname already contains domainname.
455     * Split out hostname and domainname
456     * components
457     */
458    *domdot++ = '\0';
459    hostdomain = domdot;
460  }
461  xstrlcpy(hostd, hostname, sizeof(hostd));
462  am_set_hostname(hostname);
463
464  /*
465   * Setup signal handlers
466   */
467  /* SIGINT: trap interrupts for shutdowns */
468  setup_sighandler(SIGINT, sigterm);
469  /* SIGTERM: trap terminate so we can shutdown cleanly (some chance) */
470  setup_sighandler(SIGTERM, sigterm);
471  /* SIGHUP: hangups tell us to reload the cache */
472  setup_sighandler(SIGHUP, sighup);
473  /*
474   * SIGCHLD: trap Death-of-a-child.  These allow us to pick up the exit
475   * status of backgrounded mounts.  See "sched.c".
476   */
477  setup_sighandler(SIGCHLD, sigchld);
478#ifdef HAVE_SIGACTION
479  /* construct global "masked_sigs" used in nfs_start.c */
480  sigemptyset(&masked_sigs);
481  sigaddset(&masked_sigs, SIGINT);
482  sigaddset(&masked_sigs, SIGTERM);
483  sigaddset(&masked_sigs, SIGHUP);
484  sigaddset(&masked_sigs, SIGCHLD);
485#endif /* HAVE_SIGACTION */
486
487  /*
488   * Fix-up any umask problems.  Most systems default
489   * to 002 which is not too convenient for our purposes
490   */
491  orig_umask = umask(0);
492
493  /*
494   * Figure out primary network name
495   */
496  getwire(&PrimNetName, &PrimNetNum);
497
498  /*
499   * Determine command-line arguments.
500   * (Also initialize amd.conf parameters, maps, and more.)
501   */
502  get_args(argc, argv);
503
504  /*
505   * Log version information.
506   */
507  vertmp = get_version_string();
508  verstr = strtok(vertmp, "\n");
509  plog(XLOG_INFO, "AM-UTILS VERSION INFORMATION:");
510  while (verstr) {
511    plog(XLOG_INFO, "%s", verstr);
512    verstr = strtok(NULL, "\n");
513  }
514  XFREE(vertmp);
515
516  /*
517   * Get our own IP address so that we can mount the automounter.  We pass
518   * localhost_address which could be used as the default localhost
519   * name/address in amu_get_myaddress().
520   */
521  amu_get_myaddress(&myipaddr, gopt.localhost_address);
522  plog(XLOG_INFO, "My ip addr is %s", inet_ntoa(myipaddr));
523
524  /* avoid hanging on other NFS servers if started elsewhere */
525  if (chdir("/") < 0)
526    plog(XLOG_INFO, "cannot chdir to /: %m");
527
528  /*
529   * Now check we are root.
530   */
531  if (geteuid() != 0) {
532    plog(XLOG_FATAL, "Must be root to mount filesystems (euid = %ld)", (long) geteuid());
533    going_down(1);
534    return 1;
535  }
536
537#ifdef HAVE_MAP_NIS
538  /*
539   * If the domain was specified then bind it here
540   * to circumvent any default bindings that may
541   * be done in the C library.
542   */
543  if (gopt.nis_domain && yp_bind(gopt.nis_domain)) {
544    plog(XLOG_FATAL, "Can't bind to NIS domain \"%s\"", gopt.nis_domain);
545    going_down(1);
546    return 1;
547  }
548#endif /* HAVE_MAP_NIS */
549
550  if (amuDebug(D_DAEMON))
551    ppid = daemon_mode();
552
553  /*
554   * Lock process text and data segment in memory.
555   */
556  if (gopt.flags & CFM_PROCESS_LOCK) {
557    do_memory_locking();
558  }
559
560  do_mapc_reload = clocktime(NULL) + gopt.map_reload_interval;
561
562  /*
563   * Register automounter with system.
564   */
565  error = mount_automounter(ppid);
566  if (error && ppid)
567    kill(ppid, SIGALRM);
568
569#ifdef HAVE_FS_AUTOFS
570  /*
571   * XXX this should be part of going_down(), but I can't move it there
572   * because it would be calling non-library code from the library... ugh
573   */
574  if (amd_use_autofs)
575    destroy_autofs_service();
576#endif /* HAVE_FS_AUTOFS */
577
578  going_down(error);
579
580  abort();
581  return 1; /* should never get here */
582}
583