xref: /freebsd/usr.sbin/nfsd/nfsd.c (revision 145992504973bd16cf3518af9ba5ce185fefa82a)
1 /*
2  * Copyright (c) 1989, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1989, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)nfsd.c	8.9 (Berkeley) 3/29/95";
42 #endif
43 static const char rcsid[] =
44   "$FreeBSD$";
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/syslog.h>
49 #include <sys/wait.h>
50 #include <sys/mount.h>
51 #include <sys/fcntl.h>
52 #include <sys/linker.h>
53 #include <sys/module.h>
54 #include <sys/types.h>
55 #include <sys/stat.h>
56 #include <sys/ucred.h>
57 
58 #include <rpc/rpc.h>
59 #include <rpc/pmap_clnt.h>
60 #include <rpcsvc/nfs_prot.h>
61 
62 #include <netdb.h>
63 #include <arpa/inet.h>
64 #include <nfsserver/nfs.h>
65 #include <nfs/nfssvc.h>
66 
67 #include <err.h>
68 #include <errno.h>
69 #include <signal.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73 #include <unistd.h>
74 
75 /* Global defs */
76 #ifdef DEBUG
77 #define	syslog(e, s...)	fprintf(stderr,s)
78 static int	debug = 1;
79 #else
80 static int	debug = 0;
81 #endif
82 
83 #define	NFSD_STABLERESTART	"/var/db/nfs-stablerestart"
84 #define	NFSD_STABLEBACKUP	"/var/db/nfs-stablerestart.bak"
85 #define	MAXNFSDCNT	256
86 #define	DEFNFSDCNT	 4
87 static pid_t children[MAXNFSDCNT]; /* PIDs of children */
88 static int nfsdcnt;		/* number of children */
89 static int new_syscall;
90 static int run_v4server = 1;	/* Force running of nfsv4 server */
91 static int nfssvc_nfsd;		/* Set to correct NFSSVC_xxx flag */
92 static int stablefd = -1;	/* Fd for the stable restart file */
93 static int backupfd;		/* Fd for the backup stable restart file */
94 
95 void	cleanup(int);
96 void	child_cleanup(int);
97 void	killchildren(void);
98 void	nfsd_exit(int);
99 void	nonfs(int);
100 void	reapchild(int);
101 int	setbindhost(struct addrinfo **ia, const char *bindhost,
102 	    struct addrinfo hints);
103 void	start_server(int);
104 void	unregistration(void);
105 void	usage(void);
106 void	open_stable(int *, int *);
107 void	copy_stable(int, int);
108 void	backup_stable(int);
109 
110 /*
111  * Nfs server daemon mostly just a user context for nfssvc()
112  *
113  * 1 - do file descriptor and signal cleanup
114  * 2 - fork the nfsd(s)
115  * 3 - create server socket(s)
116  * 4 - register socket with rpcbind
117  *
118  * For connectionless protocols, just pass the socket into the kernel via.
119  * nfssvc().
120  * For connection based sockets, loop doing accepts. When you get a new
121  * socket from accept, pass the msgsock into the kernel via. nfssvc().
122  * The arguments are:
123  *	-r - reregister with rpcbind
124  *	-d - unregister with rpcbind
125  *	-t - support tcp nfs clients
126  *	-u - support udp nfs clients
127  *	-e - forces it to run a server that supports nfsv4
128  * followed by "n" which is the number of nfsds' to fork off
129  */
130 int
131 main(int argc, char **argv)
132 {
133 	struct nfsd_addsock_args addsockargs;
134 	struct addrinfo *ai_udp, *ai_tcp, *ai_udp6, *ai_tcp6, hints;
135 	struct netconfig *nconf_udp, *nconf_tcp, *nconf_udp6, *nconf_tcp6;
136 	struct netbuf nb_udp, nb_tcp, nb_udp6, nb_tcp6;
137 	struct sockaddr_in inetpeer;
138 	struct sockaddr_in6 inet6peer;
139 	fd_set ready, sockbits;
140 	fd_set v4bits, v6bits;
141 	int ch, connect_type_cnt, i, maxsock, msgsock;
142 	socklen_t len;
143 	int on = 1, unregister, reregister, sock;
144 	int tcp6sock, ip6flag, tcpflag, tcpsock;
145 	int udpflag, ecode, error, s, srvcnt;
146 	int bindhostc, bindanyflag, rpcbreg, rpcbregcnt;
147 	int nfssvc_addsock;
148 	char **bindhost = NULL;
149 	pid_t pid;
150 
151 	nfsdcnt = DEFNFSDCNT;
152 	unregister = reregister = tcpflag = maxsock = 0;
153 	bindanyflag = udpflag = connect_type_cnt = bindhostc = 0;
154 #define	GETOPT	"ah:n:rdtueo"
155 #define	USAGE	"[-ardtueo] [-n num_servers] [-h bindip]"
156 	while ((ch = getopt(argc, argv, GETOPT)) != -1)
157 		switch (ch) {
158 		case 'a':
159 			bindanyflag = 1;
160 			break;
161 		case 'n':
162 			nfsdcnt = atoi(optarg);
163 			if (nfsdcnt < 1 || nfsdcnt > MAXNFSDCNT) {
164 				warnx("nfsd count %d; reset to %d", nfsdcnt,
165 				    DEFNFSDCNT);
166 				nfsdcnt = DEFNFSDCNT;
167 			}
168 			break;
169 		case 'h':
170 			bindhostc++;
171 			bindhost = realloc(bindhost,sizeof(char *)*bindhostc);
172 			if (bindhost == NULL)
173 				errx(1, "Out of memory");
174 			bindhost[bindhostc-1] = strdup(optarg);
175 			if (bindhost[bindhostc-1] == NULL)
176 				errx(1, "Out of memory");
177 			break;
178 		case 'r':
179 			reregister = 1;
180 			break;
181 		case 'd':
182 			unregister = 1;
183 			break;
184 		case 't':
185 			tcpflag = 1;
186 			break;
187 		case 'u':
188 			udpflag = 1;
189 			break;
190 		case 'e':
191 			/* now a no-op, since this is the default */
192 			break;
193 		case 'o':
194 			run_v4server = 0;
195 			break;
196 		default:
197 		case '?':
198 			usage();
199 		};
200 	if (!tcpflag && !udpflag)
201 		udpflag = 1;
202 	argv += optind;
203 	argc -= optind;
204 
205 	/*
206 	 * XXX
207 	 * Backward compatibility, trailing number is the count of daemons.
208 	 */
209 	if (argc > 1)
210 		usage();
211 	if (argc == 1) {
212 		nfsdcnt = atoi(argv[0]);
213 		if (nfsdcnt < 1 || nfsdcnt > MAXNFSDCNT) {
214 			warnx("nfsd count %d; reset to %d", nfsdcnt,
215 			    DEFNFSDCNT);
216 			nfsdcnt = DEFNFSDCNT;
217 		}
218 	}
219 
220 	/*
221 	 * Unless the "-o" option was specified, try and run "nfsd".
222 	 * If "-o" was specified, try and run "nfsserver".
223 	 */
224 	if (run_v4server > 0) {
225 		if (modfind("nfsd") < 0) {
226 			/* Not present in kernel, try loading it */
227 			if (kldload("nfsd") < 0 || modfind("nfsd") < 0)
228 				errx(1, "NFS server is not available");
229 		}
230 	} else if (modfind("nfsserver") < 0) {
231 		/* Not present in kernel, try loading it */
232 		if (kldload("nfsserver") < 0 || modfind("nfsserver") < 0)
233 			errx(1, "NFS server is not available");
234 	}
235 
236 	ip6flag = 1;
237 	s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
238 	if (s == -1) {
239 		if (errno != EPROTONOSUPPORT)
240 			err(1, "socket");
241 		ip6flag = 0;
242 	} else if (getnetconfigent("udp6") == NULL ||
243 		getnetconfigent("tcp6") == NULL) {
244 		ip6flag = 0;
245 	}
246 	if (s != -1)
247 		close(s);
248 
249 	if (bindhostc == 0 || bindanyflag) {
250 		bindhostc++;
251 		bindhost = realloc(bindhost,sizeof(char *)*bindhostc);
252 		if (bindhost == NULL)
253 			errx(1, "Out of memory");
254 		bindhost[bindhostc-1] = strdup("*");
255 		if (bindhost[bindhostc-1] == NULL)
256 			errx(1, "Out of memory");
257 	}
258 
259 	if (unregister) {
260 		unregistration();
261 		exit (0);
262 	}
263 	if (reregister) {
264 		if (udpflag) {
265 			memset(&hints, 0, sizeof hints);
266 			hints.ai_flags = AI_PASSIVE;
267 			hints.ai_family = AF_INET;
268 			hints.ai_socktype = SOCK_DGRAM;
269 			hints.ai_protocol = IPPROTO_UDP;
270 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp);
271 			if (ecode != 0)
272 				err(1, "getaddrinfo udp: %s", gai_strerror(ecode));
273 			nconf_udp = getnetconfigent("udp");
274 			if (nconf_udp == NULL)
275 				err(1, "getnetconfigent udp failed");
276 			nb_udp.buf = ai_udp->ai_addr;
277 			nb_udp.len = nb_udp.maxlen = ai_udp->ai_addrlen;
278 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_udp, &nb_udp)) ||
279 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_udp, &nb_udp)))
280 				err(1, "rpcb_set udp failed");
281 			freeaddrinfo(ai_udp);
282 		}
283 		if (udpflag && ip6flag) {
284 			memset(&hints, 0, sizeof hints);
285 			hints.ai_flags = AI_PASSIVE;
286 			hints.ai_family = AF_INET6;
287 			hints.ai_socktype = SOCK_DGRAM;
288 			hints.ai_protocol = IPPROTO_UDP;
289 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp6);
290 			if (ecode != 0)
291 				err(1, "getaddrinfo udp6: %s", gai_strerror(ecode));
292 			nconf_udp6 = getnetconfigent("udp6");
293 			if (nconf_udp6 == NULL)
294 				err(1, "getnetconfigent udp6 failed");
295 			nb_udp6.buf = ai_udp6->ai_addr;
296 			nb_udp6.len = nb_udp6.maxlen = ai_udp6->ai_addrlen;
297 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_udp6, &nb_udp6)) ||
298 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_udp6, &nb_udp6)))
299 				err(1, "rpcb_set udp6 failed");
300 			freeaddrinfo(ai_udp6);
301 		}
302 		if (tcpflag) {
303 			memset(&hints, 0, sizeof hints);
304 			hints.ai_flags = AI_PASSIVE;
305 			hints.ai_family = AF_INET;
306 			hints.ai_socktype = SOCK_STREAM;
307 			hints.ai_protocol = IPPROTO_TCP;
308 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp);
309 			if (ecode != 0)
310 				err(1, "getaddrinfo tcp: %s", gai_strerror(ecode));
311 			nconf_tcp = getnetconfigent("tcp");
312 			if (nconf_tcp == NULL)
313 				err(1, "getnetconfigent tcp failed");
314 			nb_tcp.buf = ai_tcp->ai_addr;
315 			nb_tcp.len = nb_tcp.maxlen = ai_tcp->ai_addrlen;
316 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_tcp, &nb_tcp)) ||
317 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_tcp, &nb_tcp)))
318 				err(1, "rpcb_set tcp failed");
319 			freeaddrinfo(ai_tcp);
320 		}
321 		if (tcpflag && ip6flag) {
322 			memset(&hints, 0, sizeof hints);
323 			hints.ai_flags = AI_PASSIVE;
324 			hints.ai_family = AF_INET6;
325 			hints.ai_socktype = SOCK_STREAM;
326 			hints.ai_protocol = IPPROTO_TCP;
327 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp6);
328 			if (ecode != 0)
329 				err(1, "getaddrinfo tcp6: %s", gai_strerror(ecode));
330 			nconf_tcp6 = getnetconfigent("tcp6");
331 			if (nconf_tcp6 == NULL)
332 				err(1, "getnetconfigent tcp6 failed");
333 			nb_tcp6.buf = ai_tcp6->ai_addr;
334 			nb_tcp6.len = nb_tcp6.maxlen = ai_tcp6->ai_addrlen;
335 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_tcp6, &nb_tcp6)) ||
336 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_tcp6, &nb_tcp6)))
337 				err(1, "rpcb_set tcp6 failed");
338 			freeaddrinfo(ai_tcp6);
339 		}
340 		exit (0);
341 	}
342 	if (debug == 0) {
343 		daemon(0, 0);
344 		(void)signal(SIGHUP, SIG_IGN);
345 		(void)signal(SIGINT, SIG_IGN);
346 		/*
347 		 * nfsd sits in the kernel most of the time.  It needs
348 		 * to ignore SIGTERM/SIGQUIT in order to stay alive as long
349 		 * as possible during a shutdown, otherwise loopback
350 		 * mounts will not be able to unmount.
351 		 */
352 		(void)signal(SIGTERM, SIG_IGN);
353 		(void)signal(SIGQUIT, SIG_IGN);
354 	}
355 	(void)signal(SIGSYS, nonfs);
356 	(void)signal(SIGCHLD, reapchild);
357 	(void)signal(SIGUSR2, backup_stable);
358 
359 	openlog("nfsd", LOG_PID, LOG_DAEMON);
360 
361 	/*
362 	 * For V4, we open the stablerestart file and call nfssvc()
363 	 * to get it loaded. This is done before the daemons do the
364 	 * regular nfssvc() call to service NFS requests.
365 	 * (This way the file remains open until the last nfsd is killed
366 	 *  off.)
367 	 * It and the backup copy will be created as empty files
368 	 * the first time this nfsd is started and should never be
369 	 * deleted/replaced if at all possible. It should live on a
370 	 * local, non-volatile storage device that does not do hardware
371 	 * level write-back caching. (See SCSI doc for more information
372 	 * on how to prevent write-back caching on SCSI disks.)
373 	 */
374 	if (run_v4server > 0) {
375 		open_stable(&stablefd, &backupfd);
376 		if (stablefd < 0) {
377 			syslog(LOG_ERR, "Can't open %s\n", NFSD_STABLERESTART);
378 			exit(1);
379 		}
380 		/* This system call will fail for old kernels, but that's ok. */
381 		nfssvc(NFSSVC_BACKUPSTABLE, NULL);
382 		if (nfssvc(NFSSVC_STABLERESTART, (caddr_t)&stablefd) < 0) {
383 			syslog(LOG_ERR, "Can't read stable storage file\n");
384 			exit(1);
385 		}
386 		nfssvc_addsock = NFSSVC_NFSDADDSOCK;
387 		nfssvc_nfsd = NFSSVC_NFSDNFSD;
388 		new_syscall = TRUE;
389 	} else {
390 		nfssvc_addsock = NFSSVC_ADDSOCK;
391 		nfssvc_nfsd = NFSSVC_NFSD;
392 		/*
393 		 * Figure out if the kernel supports the new-style
394 		 * NFSSVC_NFSD. Old kernels will return ENXIO because they
395 		 * don't recognise the flag value, new ones will return EINVAL
396 		 * because argp is NULL.
397 		 */
398 		new_syscall = FALSE;
399 		if (nfssvc(NFSSVC_NFSD, NULL) < 0 && errno == EINVAL)
400 			new_syscall = TRUE;
401 	}
402 
403 	if (!new_syscall) {
404 		/* If we use UDP only, we start the last server below. */
405 		srvcnt = tcpflag ? nfsdcnt : nfsdcnt - 1;
406 		for (i = 0; i < srvcnt; i++) {
407 			switch ((pid = fork())) {
408 			case -1:
409 				syslog(LOG_ERR, "fork: %m");
410 				nfsd_exit(1);
411 			case 0:
412 				break;
413 			default:
414 				children[i] = pid;
415 				continue;
416 			}
417 			(void)signal(SIGUSR1, child_cleanup);
418 			setproctitle("server");
419 
420 			start_server(0);
421 		}
422 	} else if (tcpflag) {
423 		/*
424 		 * For TCP mode, we fork once to start the first
425 		 * kernel nfsd thread. The kernel will add more
426 		 * threads as needed.
427 		 */
428 		pid = fork();
429 		if (pid == -1) {
430 			syslog(LOG_ERR, "fork: %m");
431 			nfsd_exit(1);
432 		}
433 		if (pid) {
434 			children[0] = pid;
435 		} else {
436 			(void)signal(SIGUSR1, child_cleanup);
437 			setproctitle("server");
438 			start_server(0);
439 		}
440 	}
441 
442 	(void)signal(SIGUSR1, cleanup);
443 	FD_ZERO(&v4bits);
444 	FD_ZERO(&v6bits);
445 	FD_ZERO(&sockbits);
446 
447 	rpcbregcnt = 0;
448 	/* Set up the socket for udp and rpcb register it. */
449 	if (udpflag) {
450 		rpcbreg = 0;
451 		for (i = 0; i < bindhostc; i++) {
452 			memset(&hints, 0, sizeof hints);
453 			hints.ai_flags = AI_PASSIVE;
454 			hints.ai_family = AF_INET;
455 			hints.ai_socktype = SOCK_DGRAM;
456 			hints.ai_protocol = IPPROTO_UDP;
457 			if (setbindhost(&ai_udp, bindhost[i], hints) == 0) {
458 				rpcbreg = 1;
459 				rpcbregcnt++;
460 				if ((sock = socket(ai_udp->ai_family,
461 				    ai_udp->ai_socktype,
462 				    ai_udp->ai_protocol)) < 0) {
463 					syslog(LOG_ERR,
464 					    "can't create udp socket");
465 					nfsd_exit(1);
466 				}
467 				if (bind(sock, ai_udp->ai_addr,
468 				    ai_udp->ai_addrlen) < 0) {
469 					syslog(LOG_ERR,
470 					    "can't bind udp addr %s: %m",
471 					    bindhost[i]);
472 					nfsd_exit(1);
473 				}
474 				freeaddrinfo(ai_udp);
475 				addsockargs.sock = sock;
476 				addsockargs.name = NULL;
477 				addsockargs.namelen = 0;
478 				if (nfssvc(nfssvc_addsock, &addsockargs) < 0) {
479 					syslog(LOG_ERR, "can't Add UDP socket");
480 					nfsd_exit(1);
481 				}
482 				(void)close(sock);
483 			}
484 		}
485 		if (rpcbreg == 1) {
486 			memset(&hints, 0, sizeof hints);
487 			hints.ai_flags = AI_PASSIVE;
488 			hints.ai_family = AF_INET;
489 			hints.ai_socktype = SOCK_DGRAM;
490 			hints.ai_protocol = IPPROTO_UDP;
491 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp);
492 			if (ecode != 0) {
493 				syslog(LOG_ERR, "getaddrinfo udp: %s",
494 				   gai_strerror(ecode));
495 				nfsd_exit(1);
496 			}
497 			nconf_udp = getnetconfigent("udp");
498 			if (nconf_udp == NULL)
499 				err(1, "getnetconfigent udp failed");
500 			nb_udp.buf = ai_udp->ai_addr;
501 			nb_udp.len = nb_udp.maxlen = ai_udp->ai_addrlen;
502 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_udp, &nb_udp)) ||
503 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_udp, &nb_udp)))
504 				err(1, "rpcb_set udp failed");
505 			freeaddrinfo(ai_udp);
506 		}
507 	}
508 
509 	/* Set up the socket for udp6 and rpcb register it. */
510 	if (udpflag && ip6flag) {
511 		rpcbreg = 0;
512 		for (i = 0; i < bindhostc; i++) {
513 			memset(&hints, 0, sizeof hints);
514 			hints.ai_flags = AI_PASSIVE;
515 			hints.ai_family = AF_INET6;
516 			hints.ai_socktype = SOCK_DGRAM;
517 			hints.ai_protocol = IPPROTO_UDP;
518 			if (setbindhost(&ai_udp6, bindhost[i], hints) == 0) {
519 				rpcbreg = 1;
520 				rpcbregcnt++;
521 				if ((sock = socket(ai_udp6->ai_family,
522 				    ai_udp6->ai_socktype,
523 				    ai_udp6->ai_protocol)) < 0) {
524 					syslog(LOG_ERR,
525 						"can't create udp6 socket");
526 					nfsd_exit(1);
527 				}
528 				if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
529 				    &on, sizeof on) < 0) {
530 					syslog(LOG_ERR,
531 					    "can't set v6-only binding for "
532 					    "udp6 socket: %m");
533 					nfsd_exit(1);
534 				}
535 				if (bind(sock, ai_udp6->ai_addr,
536 				    ai_udp6->ai_addrlen) < 0) {
537 					syslog(LOG_ERR,
538 					    "can't bind udp6 addr %s: %m",
539 					    bindhost[i]);
540 					nfsd_exit(1);
541 				}
542 				freeaddrinfo(ai_udp6);
543 				addsockargs.sock = sock;
544 				addsockargs.name = NULL;
545 				addsockargs.namelen = 0;
546 				if (nfssvc(nfssvc_addsock, &addsockargs) < 0) {
547 					syslog(LOG_ERR,
548 					    "can't add UDP6 socket");
549 					nfsd_exit(1);
550 				}
551 				(void)close(sock);
552 			}
553 		}
554 		if (rpcbreg == 1) {
555 			memset(&hints, 0, sizeof hints);
556 			hints.ai_flags = AI_PASSIVE;
557 			hints.ai_family = AF_INET6;
558 			hints.ai_socktype = SOCK_DGRAM;
559 			hints.ai_protocol = IPPROTO_UDP;
560 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp6);
561 			if (ecode != 0) {
562 				syslog(LOG_ERR, "getaddrinfo udp6: %s",
563 				   gai_strerror(ecode));
564 				nfsd_exit(1);
565 			}
566 			nconf_udp6 = getnetconfigent("udp6");
567 			if (nconf_udp6 == NULL)
568 				err(1, "getnetconfigent udp6 failed");
569 			nb_udp6.buf = ai_udp6->ai_addr;
570 			nb_udp6.len = nb_udp6.maxlen = ai_udp6->ai_addrlen;
571 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_udp6, &nb_udp6)) ||
572 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_udp6, &nb_udp6)))
573 				err(1, "rpcb_set udp6 failed");
574 			freeaddrinfo(ai_udp6);
575 		}
576 	}
577 
578 	/* Set up the socket for tcp and rpcb register it. */
579 	if (tcpflag) {
580 		rpcbreg = 0;
581 		for (i = 0; i < bindhostc; i++) {
582 			memset(&hints, 0, sizeof hints);
583 			hints.ai_flags = AI_PASSIVE;
584 			hints.ai_family = AF_INET;
585 			hints.ai_socktype = SOCK_STREAM;
586 			hints.ai_protocol = IPPROTO_TCP;
587 			if (setbindhost(&ai_tcp, bindhost[i], hints) == 0) {
588 				rpcbreg = 1;
589 				rpcbregcnt++;
590 				if ((tcpsock = socket(AF_INET, SOCK_STREAM,
591 				    0)) < 0) {
592 					syslog(LOG_ERR,
593 					    "can't create tcp socket");
594 					nfsd_exit(1);
595 				}
596 				if (setsockopt(tcpsock, SOL_SOCKET,
597 				    SO_REUSEADDR,
598 				    (char *)&on, sizeof(on)) < 0)
599 					syslog(LOG_ERR,
600 					     "setsockopt SO_REUSEADDR: %m");
601 				if (bind(tcpsock, ai_tcp->ai_addr,
602 				    ai_tcp->ai_addrlen) < 0) {
603 					syslog(LOG_ERR,
604 					    "can't bind tcp addr %s: %m",
605 					    bindhost[i]);
606 					nfsd_exit(1);
607 				}
608 				if (listen(tcpsock, 5) < 0) {
609 					syslog(LOG_ERR, "listen failed");
610 					nfsd_exit(1);
611 				}
612 				freeaddrinfo(ai_tcp);
613 				FD_SET(tcpsock, &sockbits);
614 				FD_SET(tcpsock, &v4bits);
615 				maxsock = tcpsock;
616 				connect_type_cnt++;
617 			}
618 		}
619 		if (rpcbreg == 1) {
620 			memset(&hints, 0, sizeof hints);
621 			hints.ai_flags = AI_PASSIVE;
622 			hints.ai_family = AF_INET;
623 			hints.ai_socktype = SOCK_STREAM;
624 			hints.ai_protocol = IPPROTO_TCP;
625 			ecode = getaddrinfo(NULL, "nfs", &hints,
626 			     &ai_tcp);
627 			if (ecode != 0) {
628 				syslog(LOG_ERR, "getaddrinfo tcp: %s",
629 				   gai_strerror(ecode));
630 				nfsd_exit(1);
631 			}
632 			nconf_tcp = getnetconfigent("tcp");
633 			if (nconf_tcp == NULL)
634 				err(1, "getnetconfigent tcp failed");
635 			nb_tcp.buf = ai_tcp->ai_addr;
636 			nb_tcp.len = nb_tcp.maxlen = ai_tcp->ai_addrlen;
637 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_tcp,
638 			    &nb_tcp)) || (!rpcb_set(NFS_PROGRAM, 3,
639 			    nconf_tcp, &nb_tcp)))
640 				err(1, "rpcb_set tcp failed");
641 			freeaddrinfo(ai_tcp);
642 		}
643 	}
644 
645 	/* Set up the socket for tcp6 and rpcb register it. */
646 	if (tcpflag && ip6flag) {
647 		rpcbreg = 0;
648 		for (i = 0; i < bindhostc; i++) {
649 			memset(&hints, 0, sizeof hints);
650 			hints.ai_flags = AI_PASSIVE;
651 			hints.ai_family = AF_INET6;
652 			hints.ai_socktype = SOCK_STREAM;
653 			hints.ai_protocol = IPPROTO_TCP;
654 			if (setbindhost(&ai_tcp6, bindhost[i], hints) == 0) {
655 				rpcbreg = 1;
656 				rpcbregcnt++;
657 				if ((tcp6sock = socket(ai_tcp6->ai_family,
658 				    ai_tcp6->ai_socktype,
659 				    ai_tcp6->ai_protocol)) < 0) {
660 					syslog(LOG_ERR,
661 					    "can't create tcp6 socket");
662 					nfsd_exit(1);
663 				}
664 				if (setsockopt(tcp6sock, SOL_SOCKET,
665 				    SO_REUSEADDR,
666 				    (char *)&on, sizeof(on)) < 0)
667 					syslog(LOG_ERR,
668 					    "setsockopt SO_REUSEADDR: %m");
669 				if (setsockopt(tcp6sock, IPPROTO_IPV6,
670 				    IPV6_V6ONLY, &on, sizeof on) < 0) {
671 					syslog(LOG_ERR,
672 					"can't set v6-only binding for tcp6 "
673 					    "socket: %m");
674 					nfsd_exit(1);
675 				}
676 				if (bind(tcp6sock, ai_tcp6->ai_addr,
677 				    ai_tcp6->ai_addrlen) < 0) {
678 					syslog(LOG_ERR,
679 					    "can't bind tcp6 addr %s: %m",
680 					    bindhost[i]);
681 					nfsd_exit(1);
682 				}
683 				if (listen(tcp6sock, 5) < 0) {
684 					syslog(LOG_ERR, "listen failed");
685 					nfsd_exit(1);
686 				}
687 				freeaddrinfo(ai_tcp6);
688 				FD_SET(tcp6sock, &sockbits);
689 				FD_SET(tcp6sock, &v6bits);
690 				if (maxsock < tcp6sock)
691 					maxsock = tcp6sock;
692 				connect_type_cnt++;
693 			}
694 		}
695 		if (rpcbreg == 1) {
696 			memset(&hints, 0, sizeof hints);
697 			hints.ai_flags = AI_PASSIVE;
698 			hints.ai_family = AF_INET6;
699 			hints.ai_socktype = SOCK_STREAM;
700 			hints.ai_protocol = IPPROTO_TCP;
701 			ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp6);
702 			if (ecode != 0) {
703 				syslog(LOG_ERR, "getaddrinfo tcp6: %s",
704 				   gai_strerror(ecode));
705 				nfsd_exit(1);
706 			}
707 			nconf_tcp6 = getnetconfigent("tcp6");
708 			if (nconf_tcp6 == NULL)
709 				err(1, "getnetconfigent tcp6 failed");
710 			nb_tcp6.buf = ai_tcp6->ai_addr;
711 			nb_tcp6.len = nb_tcp6.maxlen = ai_tcp6->ai_addrlen;
712 			if ((!rpcb_set(NFS_PROGRAM, 2, nconf_tcp6, &nb_tcp6)) ||
713 			    (!rpcb_set(NFS_PROGRAM, 3, nconf_tcp6, &nb_tcp6)))
714 				err(1, "rpcb_set tcp6 failed");
715 			freeaddrinfo(ai_tcp6);
716 		}
717 	}
718 
719 	if (rpcbregcnt == 0) {
720 		syslog(LOG_ERR, "rpcb_set() failed, nothing to do: %m");
721 		nfsd_exit(1);
722 	}
723 
724 	if (tcpflag && connect_type_cnt == 0) {
725 		syslog(LOG_ERR, "tcp connects == 0, nothing to do: %m");
726 		nfsd_exit(1);
727 	}
728 
729 	setproctitle("master");
730 	/*
731 	 * We always want a master to have a clean way to to shut nfsd down
732 	 * (with unregistration): if the master is killed, it unregisters and
733 	 * kills all children. If we run for UDP only (and so do not have to
734 	 * loop waiting waiting for accept), we instead make the parent
735 	 * a "server" too. start_server will not return.
736 	 */
737 	if (!tcpflag)
738 		start_server(1);
739 
740 	/*
741 	 * Loop forever accepting connections and passing the sockets
742 	 * into the kernel for the mounts.
743 	 */
744 	for (;;) {
745 		ready = sockbits;
746 		if (connect_type_cnt > 1) {
747 			if (select(maxsock + 1,
748 			    &ready, NULL, NULL, NULL) < 1) {
749 				error = errno;
750 				if (error == EINTR)
751 					continue;
752 				syslog(LOG_ERR, "select failed: %m");
753 				nfsd_exit(1);
754 			}
755 		}
756 		for (tcpsock = 0; tcpsock <= maxsock; tcpsock++) {
757 			if (FD_ISSET(tcpsock, &ready)) {
758 				if (FD_ISSET(tcpsock, &v4bits)) {
759 					len = sizeof(inetpeer);
760 					if ((msgsock = accept(tcpsock,
761 					    (struct sockaddr *)&inetpeer, &len)) < 0) {
762 						error = errno;
763 						syslog(LOG_ERR, "accept failed: %m");
764 						if (error == ECONNABORTED ||
765 						    error == EINTR)
766 							continue;
767 						nfsd_exit(1);
768 					}
769 					memset(inetpeer.sin_zero, 0,
770 						sizeof(inetpeer.sin_zero));
771 					if (setsockopt(msgsock, SOL_SOCKET,
772 					    SO_KEEPALIVE, (char *)&on, sizeof(on)) < 0)
773 						syslog(LOG_ERR,
774 						    "setsockopt SO_KEEPALIVE: %m");
775 					addsockargs.sock = msgsock;
776 					addsockargs.name = (caddr_t)&inetpeer;
777 					addsockargs.namelen = len;
778 					nfssvc(nfssvc_addsock, &addsockargs);
779 					(void)close(msgsock);
780 				} else if (FD_ISSET(tcpsock, &v6bits)) {
781 					len = sizeof(inet6peer);
782 					if ((msgsock = accept(tcpsock,
783 					    (struct sockaddr *)&inet6peer,
784 					    &len)) < 0) {
785 						error = errno;
786 						syslog(LOG_ERR,
787 						     "accept failed: %m");
788 						if (error == ECONNABORTED ||
789 						    error == EINTR)
790 							continue;
791 						nfsd_exit(1);
792 					}
793 					if (setsockopt(msgsock, SOL_SOCKET,
794 					    SO_KEEPALIVE, (char *)&on,
795 					    sizeof(on)) < 0)
796 						syslog(LOG_ERR, "setsockopt "
797 						    "SO_KEEPALIVE: %m");
798 					addsockargs.sock = msgsock;
799 					addsockargs.name = (caddr_t)&inet6peer;
800 					addsockargs.namelen = len;
801 					nfssvc(nfssvc_addsock, &addsockargs);
802 					(void)close(msgsock);
803 				}
804 			}
805 		}
806 	}
807 }
808 
809 int
810 setbindhost(struct addrinfo **ai, const char *bindhost, struct addrinfo hints)
811 {
812 	int ecode;
813 	u_int32_t host_addr[4];  /* IPv4 or IPv6 */
814 	const char *hostptr;
815 
816 	if (bindhost == NULL || strcmp("*", bindhost) == 0)
817 		hostptr = NULL;
818 	else
819 		hostptr = bindhost;
820 
821 	if (hostptr != NULL) {
822 		switch (hints.ai_family) {
823 		case AF_INET:
824 			if (inet_pton(AF_INET, hostptr, host_addr) == 1) {
825 				hints.ai_flags = AI_NUMERICHOST;
826 			} else {
827 				if (inet_pton(AF_INET6, hostptr,
828 				    host_addr) == 1)
829 					return (1);
830 			}
831 			break;
832 		case AF_INET6:
833 			if (inet_pton(AF_INET6, hostptr, host_addr) == 1) {
834 				hints.ai_flags = AI_NUMERICHOST;
835 			} else {
836 				if (inet_pton(AF_INET, hostptr,
837 				    host_addr) == 1)
838 					return (1);
839 			}
840 			break;
841 		default:
842 			break;
843 		}
844 	}
845 
846 	ecode = getaddrinfo(hostptr, "nfs", &hints, ai);
847 	if (ecode != 0) {
848 		syslog(LOG_ERR, "getaddrinfo %s: %s", bindhost,
849 		    gai_strerror(ecode));
850 		return (1);
851 	}
852 	return (0);
853 }
854 
855 void
856 usage(void)
857 {
858 	(void)fprintf(stderr, "usage: nfsd %s\n", USAGE);
859 	exit(1);
860 }
861 
862 void
863 nonfs(__unused int signo)
864 {
865 	syslog(LOG_ERR, "missing system call: NFS not available");
866 }
867 
868 void
869 reapchild(__unused int signo)
870 {
871 	pid_t pid;
872 	int i;
873 
874 	while ((pid = wait3(NULL, WNOHANG, NULL)) > 0) {
875 		for (i = 0; i < nfsdcnt; i++)
876 			if (pid == children[i])
877 				children[i] = -1;
878 	}
879 }
880 
881 void
882 unregistration(void)
883 {
884 	if ((!rpcb_unset(NFS_PROGRAM, 2, NULL)) ||
885 	    (!rpcb_unset(NFS_PROGRAM, 3, NULL)))
886 		syslog(LOG_ERR, "rpcb_unset failed");
887 }
888 
889 void
890 killchildren(void)
891 {
892 	int i;
893 
894 	for (i = 0; i < nfsdcnt; i++) {
895 		if (children[i] > 0)
896 			kill(children[i], SIGKILL);
897 	}
898 }
899 
900 /*
901  * Cleanup master after SIGUSR1.
902  */
903 void
904 cleanup(__unused int signo)
905 {
906 	nfsd_exit(0);
907 }
908 
909 /*
910  * Cleanup child after SIGUSR1.
911  */
912 void
913 child_cleanup(__unused int signo)
914 {
915 	exit(0);
916 }
917 
918 void
919 nfsd_exit(int status)
920 {
921 	killchildren();
922 	unregistration();
923 	exit(status);
924 }
925 
926 void
927 start_server(int master)
928 {
929 	char principal[MAXHOSTNAMELEN + 5];
930 	struct nfsd_nfsd_args nfsdargs;
931 	int status, error;
932 	char hostname[MAXHOSTNAMELEN + 1], *cp;
933 	struct addrinfo *aip, hints;
934 
935 	status = 0;
936 	if (new_syscall) {
937 		gethostname(hostname, sizeof (hostname));
938 		snprintf(principal, sizeof (principal), "nfs@%s", hostname);
939 		if ((cp = strchr(hostname, '.')) == NULL ||
940 		    *(cp + 1) == '\0') {
941 			/* If not fully qualified, try getaddrinfo() */
942 			memset((void *)&hints, 0, sizeof (hints));
943 			hints.ai_flags = AI_CANONNAME;
944 			error = getaddrinfo(hostname, NULL, &hints, &aip);
945 			if (error == 0) {
946 				if (aip->ai_canonname != NULL &&
947 				    (cp = strchr(aip->ai_canonname, '.')) !=
948 				    NULL && *(cp + 1) != '\0')
949 					snprintf(principal, sizeof (principal),
950 					    "nfs@%s", aip->ai_canonname);
951 				freeaddrinfo(aip);
952 			}
953 		}
954 		nfsdargs.principal = principal;
955 		nfsdargs.minthreads = nfsdcnt;
956 		nfsdargs.maxthreads = nfsdcnt;
957 		error = nfssvc(nfssvc_nfsd, &nfsdargs);
958 		if (error < 0 && errno == EAUTH) {
959 			/*
960 			 * This indicates that it could not register the
961 			 * rpcsec_gss credentials, usually because the
962 			 * gssd daemon isn't running.
963 			 * (only the experimental server with nfsv4)
964 			 */
965 			syslog(LOG_ERR, "No gssd, using AUTH_SYS only");
966 			principal[0] = '\0';
967 			error = nfssvc(nfssvc_nfsd, &nfsdargs);
968 		}
969 		if (error < 0) {
970 			syslog(LOG_ERR, "nfssvc: %m");
971 			status = 1;
972 		}
973 	} else {
974 		if (nfssvc(NFSSVC_OLDNFSD, NULL) < 0) {
975 			syslog(LOG_ERR, "nfssvc: %m");
976 			status = 1;
977 		}
978 	}
979 	if (master)
980 		nfsd_exit(status);
981 	else
982 		exit(status);
983 }
984 
985 /*
986  * Open the stable restart file and return the file descriptor for it.
987  */
988 void
989 open_stable(int *stable_fdp, int *backup_fdp)
990 {
991 	int stable_fd, backup_fd = -1, ret;
992 	struct stat st, backup_st;
993 
994 	/* Open and stat the stable restart file. */
995 	stable_fd = open(NFSD_STABLERESTART, O_RDWR, 0);
996 	if (stable_fd < 0)
997 		stable_fd = open(NFSD_STABLERESTART, O_RDWR | O_CREAT, 0600);
998 	if (stable_fd >= 0) {
999 		ret = fstat(stable_fd, &st);
1000 		if (ret < 0) {
1001 			close(stable_fd);
1002 			stable_fd = -1;
1003 		}
1004 	}
1005 
1006 	/* Open and stat the backup stable restart file. */
1007 	if (stable_fd >= 0) {
1008 		backup_fd = open(NFSD_STABLEBACKUP, O_RDWR, 0);
1009 		if (backup_fd < 0)
1010 			backup_fd = open(NFSD_STABLEBACKUP, O_RDWR | O_CREAT,
1011 			    0600);
1012 		if (backup_fd >= 0) {
1013 			ret = fstat(backup_fd, &backup_st);
1014 			if (ret < 0) {
1015 				close(backup_fd);
1016 				backup_fd = -1;
1017 			}
1018 		}
1019 		if (backup_fd < 0) {
1020 			close(stable_fd);
1021 			stable_fd = -1;
1022 		}
1023 	}
1024 
1025 	*stable_fdp = stable_fd;
1026 	*backup_fdp = backup_fd;
1027 	if (stable_fd < 0)
1028 		return;
1029 
1030 	/* Sync up the 2 files, as required. */
1031 	if (st.st_size > 0)
1032 		copy_stable(stable_fd, backup_fd);
1033 	else if (backup_st.st_size > 0)
1034 		copy_stable(backup_fd, stable_fd);
1035 }
1036 
1037 /*
1038  * Copy the stable restart file to the backup or vice versa.
1039  */
1040 void
1041 copy_stable(int from_fd, int to_fd)
1042 {
1043 	int cnt, ret;
1044 	static char buf[1024];
1045 
1046 	ret = lseek(from_fd, (off_t)0, SEEK_SET);
1047 	if (ret >= 0)
1048 		ret = lseek(to_fd, (off_t)0, SEEK_SET);
1049 	if (ret >= 0)
1050 		ret = ftruncate(to_fd, (off_t)0);
1051 	if (ret >= 0)
1052 		do {
1053 			cnt = read(from_fd, buf, 1024);
1054 			if (cnt > 0)
1055 				ret = write(to_fd, buf, cnt);
1056 			else if (cnt < 0)
1057 				ret = cnt;
1058 		} while (cnt > 0 && ret >= 0);
1059 	if (ret >= 0)
1060 		ret = fsync(to_fd);
1061 	if (ret < 0)
1062 		syslog(LOG_ERR, "stable restart copy failure: %m");
1063 }
1064 
1065 /*
1066  * Back up the stable restart file when indicated by the kernel.
1067  */
1068 void
1069 backup_stable(__unused int signo)
1070 {
1071 
1072 	if (stablefd >= 0)
1073 		copy_stable(stablefd, backupfd);
1074 }
1075 
1076