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nfsd.c revision 1.62 
      1 /*	$NetBSD: nfsd.c,v 1.62 2014/03/29 13:50:53 gson Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Rick Macklem at The University of Guelph.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #ifndef lint
     37 __COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\
     38  The Regents of the University of California.  All rights reserved.");
     39 #endif /* not lint */
     40 
     41 #ifndef lint
     42 #if 0
     43 static char sccsid[] = "@(#)nfsd.c	8.9 (Berkeley) 3/29/95";
     44 #else
     45 __RCSID("$NetBSD: nfsd.c,v 1.62 2014/03/29 13:50:53 gson Exp $");
     46 #endif
     47 #endif /* not lint */
     48 
     49 #include <sys/param.h>
     50 #include <sys/ioctl.h>
     51 #include <sys/stat.h>
     52 #include <sys/wait.h>
     53 #include <sys/uio.h>
     54 #include <sys/ucred.h>
     55 #include <sys/mount.h>
     56 #include <sys/socket.h>
     57 #include <sys/socketvar.h>
     58 #include <poll.h>
     59 
     60 #include <rpc/rpc.h>
     61 #include <rpc/pmap_clnt.h>
     62 #include <rpc/pmap_prot.h>
     63 
     64 #include <nfs/rpcv2.h>
     65 #include <nfs/nfsproto.h>
     66 #include <nfs/nfs.h>
     67 
     68 #include <err.h>
     69 #include <errno.h>
     70 #include <fcntl.h>
     71 #include <grp.h>
     72 #include <paths.h>
     73 #include <pwd.h>
     74 #include <pthread.h>
     75 #include <signal.h>
     76 #include <stdio.h>
     77 #include <stdlib.h>
     78 #include <string.h>
     79 #include <syslog.h>
     80 #include <unistd.h>
     81 #include <netdb.h>
     82 
     83 /* Global defs */
     84 #ifdef DEBUG
     85 #define	syslog(e, s, args...)						\
     86 do {									\
     87     fprintf(stderr,(s), ## args);					\
     88     fprintf(stderr, "\n");						\
     89 } while (/*CONSTCOND*/0)
     90 static int	debug = 1;
     91 #else
     92 static int	debug = 0;
     93 #endif
     94 
     95 static void	nonfs(int);
     96 __dead static void	usage(void);
     97 
     98 static void *
     99 worker(void *dummy)
    100 {
    101 	struct	nfsd_srvargs nsd;
    102 	int nfssvc_flag;
    103 
    104 	pthread_setname_np(pthread_self(), "slave", NULL);
    105 	nfssvc_flag = NFSSVC_NFSD;
    106 	memset(&nsd, 0, sizeof(nsd));
    107 	while (nfssvc(nfssvc_flag, &nsd) < 0) {
    108 		if (errno != ENEEDAUTH) {
    109 			syslog(LOG_ERR, "nfssvc: %m");
    110 			exit(1);
    111 		}
    112 		nfssvc_flag = NFSSVC_NFSD | NFSSVC_AUTHINFAIL;
    113 	}
    114 
    115 	return NULL;
    116 }
    117 
    118 struct conf {
    119 	struct addrinfo *ai;
    120 	struct netconfig *nc;
    121 	struct netbuf nb;
    122 	struct pollfd pfd;
    123 };
    124 
    125 #define NFS_UDP4	0
    126 #define NFS_TCP4	1
    127 #define NFS_UDP6	2
    128 #define NFS_TCP6	3
    129 
    130 static int cfg_family[] = { PF_INET, PF_INET, PF_INET6, PF_INET6 };
    131 static const char *cfg_netconf[] = { "udp", "tcp", "udp6", "tcp6" };
    132 static int cfg_socktype[] = {
    133     SOCK_DGRAM, SOCK_STREAM, SOCK_DGRAM, SOCK_STREAM };
    134 static int cfg_protocol[] = {
    135     IPPROTO_UDP, IPPROTO_TCP, IPPROTO_UDP, IPPROTO_TCP };
    136 
    137 static int
    138 tryconf(struct conf *cfg, int t, int reregister)
    139 {
    140 	struct addrinfo hints;
    141 	int ecode;
    142 
    143 	memset(cfg, 0, sizeof(*cfg));
    144 	memset(&hints, 0, sizeof hints);
    145 	hints.ai_flags = AI_PASSIVE;
    146 	hints.ai_family = cfg_family[t];
    147 	hints.ai_socktype = cfg_socktype[t];
    148 	hints.ai_protocol = cfg_protocol[t];
    149 
    150 	ecode = getaddrinfo(NULL, "nfs", &hints, &cfg->ai);
    151 	if (ecode != 0) {
    152 		syslog(LOG_ERR, "getaddrinfo %s: %s", cfg_netconf[t],
    153 		    gai_strerror(ecode));
    154 		return -1;
    155 	}
    156 
    157 	cfg->nc = getnetconfigent(cfg_netconf[t]);
    158 
    159 	if (cfg->nc == NULL) {
    160 		syslog(LOG_ERR, "getnetconfigent %s failed: %m",
    161 		    cfg_netconf[t]);
    162 		goto out;
    163 	}
    164 
    165 	cfg->nb.buf = cfg->ai->ai_addr;
    166 	cfg->nb.len = cfg->nb.maxlen = cfg->ai->ai_addrlen;
    167 	if (reregister)
    168 		if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb)) {
    169 			syslog(LOG_ERR, "rpcb_set %s failed", cfg_netconf[t]);
    170 			goto out1;
    171 		}
    172 	return 0;
    173 out1:
    174 	freenetconfigent(cfg->nc);
    175 	cfg->nc = NULL;
    176 out:
    177 	freeaddrinfo(cfg->ai);
    178 	cfg->ai = NULL;
    179 	return -1;
    180 }
    181 
    182 static int
    183 setupsock(struct conf *cfg, struct pollfd *set, int p)
    184 {
    185 	int sock;
    186 	struct nfsd_args nfsdargs;
    187 	struct addrinfo *ai = cfg->ai;
    188 	int on = 1;
    189 
    190 	sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    191 
    192 	if (sock == -1) {
    193 		syslog(LOG_ERR, "can't create %s socket: %m", cfg_netconf[p]);
    194 		return -1;
    195 	}
    196 	if (cfg_family[p] == PF_INET6) {
    197 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on,
    198 		    sizeof(on)) == -1) {
    199 			syslog(LOG_ERR, "can't set v6-only binding for %s "
    200 			    "socket: %m", cfg_netconf[p]);
    201 			goto out;
    202 		}
    203 	}
    204 
    205 	if (cfg_protocol[p] == IPPROTO_TCP) {
    206 		if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
    207 		    sizeof(on)) == -1) {
    208 			syslog(LOG_ERR, "setsockopt SO_REUSEADDR for %s: %m",
    209 			    cfg_netconf[p]);
    210 			goto out;
    211 		}
    212 	}
    213 
    214 	if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
    215 		syslog(LOG_ERR, "can't bind %s addr: %m", cfg_netconf[p]);
    216 		goto out;
    217 	}
    218 
    219 	if (cfg_protocol[p] == IPPROTO_TCP) {
    220 		if (listen(sock, 5) == -1) {
    221 			syslog(LOG_ERR, "listen failed");
    222 			goto out;
    223 		}
    224 	}
    225 
    226 	if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb) ||
    227 	    !rpcb_set(RPCPROG_NFS, 3, cfg->nc, &cfg->nb)) {
    228 		syslog(LOG_ERR, "can't register with %s portmap",
    229 		    cfg_netconf[p]);
    230 		goto out;
    231 	}
    232 
    233 
    234 	if (cfg_protocol[p] == IPPROTO_TCP)
    235 		set->fd = sock;
    236 	else {
    237 		nfsdargs.sock = sock;
    238 		nfsdargs.name = NULL;
    239 		nfsdargs.namelen = 0;
    240 		if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
    241 			syslog(LOG_ERR, "can't add %s socket", cfg_netconf[p]);
    242 			goto out;
    243 		}
    244 		(void)close(sock);
    245 	}
    246 	return 0;
    247 out:
    248 	(void)close(sock);
    249 	return -1;
    250 }
    251 
    252 /*
    253  * The functions daemon2_fork() and daemon2_detach() below provide
    254  * functionality similar to daemon(3) but split into two phases.
    255  * daemon2_fork() is called early, before creating resources that
    256  * cannot be inherited across a fork, such as threads or kqueues.
    257  * When the daemon is ready to provide service, daemon2_detach()
    258  * is called to complete the daemonization and signal the parent
    259  * process to exit.
    260  *
    261  * These functions could potentially be moved to a library and
    262  * shared by other daemons.
    263  *
    264  * The return value from daemon2_fork() is a file descriptor to
    265  * be passed as the first argument to daemon2_detach().
    266  */
    267 
    268 static int
    269 daemon2_fork(void)
    270 {
    271 	 int i;
    272 	 int fd;
    273 	 int r;
    274 	 pid_t pid;
    275 	 int detach_msg_pipe[2];
    276 
    277 	 /*
    278 	  * Set up a pipe for singalling the parent, making sure the
    279 	  * write end does not get allocated one of the file
    280 	  * descriptors that may be closed in daemon2_detach().  The
    281 	  * read end does not need such protection.
    282 	  */
    283 	 for (i = 0; i < 3; i++) {
    284 		 r = pipe2(detach_msg_pipe, O_CLOEXEC|O_NOSIGPIPE);
    285 		 if (r < 0)
    286 			 return -1;
    287 		 if (detach_msg_pipe[1] <= STDERR_FILENO &&
    288 		     (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    289 			 (void)dup2(fd, detach_msg_pipe[0]);
    290 			 (void)dup2(fd, detach_msg_pipe[1]);
    291 			 if (fd > STDERR_FILENO)
    292 				 (void)close(fd);
    293 			 continue;
    294 		 }
    295 		 break;
    296 	 }
    297 
    298 	 pid = fork();
    299 	 switch (pid) {
    300 	 case -1:
    301 		 return -1;
    302 	 case 0:
    303 		 /* child */
    304 		 (void)close(detach_msg_pipe[0]);
    305 		 return detach_msg_pipe[1];
    306 	 default:
    307 		 break;
    308 	}
    309 
    310 	/* Parent */
    311 	(void)close(detach_msg_pipe[1]);
    312 
    313 	for (;;) {
    314 		ssize_t nread;
    315 		char dummy;
    316 		nread = read(detach_msg_pipe[0], &dummy, 1);
    317 		if (nread < 0) {
    318 			if (errno == EINTR)
    319 				continue;
    320 			_exit(1);
    321 		} else if (nread == 0) {
    322 			_exit(1);
    323 		} else { /* nread > 0 */
    324 			_exit(0);
    325 		}
    326 	}
    327 }
    328 
    329 static int
    330 daemon2_detach(int parentfd, int nochdir, int noclose)
    331 {
    332 	int fd;
    333 
    334 	if (setsid() == -1)
    335 		return -1;
    336 
    337 	if (!nochdir)
    338 		(void)chdir("/");
    339 
    340 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    341 		(void)dup2(fd, STDIN_FILENO);
    342 		(void)dup2(fd, STDOUT_FILENO);
    343 		(void)dup2(fd, STDERR_FILENO);
    344 		if (fd > STDERR_FILENO)
    345 			(void)close(fd);
    346 	}
    347 
    348 	while (1) {
    349 		ssize_t r = write(parentfd, "", 1);
    350 		if (r < 0) {
    351 			if (errno == EINTR)
    352 				continue;
    353 			else if (errno == EPIPE)
    354 				break;
    355 			else
    356 				return -1;
    357 		} else if (r == 0) {
    358 			/* Should not happen */
    359 			return -1;
    360 		} else {
    361 			break;
    362 		}
    363 	}
    364 
    365 	(void)close(parentfd);
    366 
    367 	return 0;
    368 }
    369 
    370 /*
    371  * Nfs server daemon mostly just a user context for nfssvc()
    372  *
    373  * 1 - do file descriptor and signal cleanup
    374  * 2 - create the nfsd thread(s)
    375  * 3 - create server socket(s)
    376  * 4 - register socket with portmap
    377  *
    378  * For connectionless protocols, just pass the socket into the kernel via
    379  * nfssvc().
    380  * For connection based sockets, loop doing accepts. When you get a new
    381  * socket from accept, pass the msgsock into the kernel via nfssvc().
    382  * The arguments are:
    383  *	-r - reregister with portmapper
    384  *	-t - support only tcp nfs clients
    385  *	-u - support only udp nfs clients
    386  *	-n num how many threads to create.
    387  *	-4 - use only ipv4
    388  *	-6 - use only ipv6
    389  */
    390 int
    391 main(int argc, char *argv[])
    392 {
    393 	struct conf cfg[4];
    394 	struct pollfd set[__arraycount(cfg)];
    395 	int ch, connect_type_cnt;
    396 	size_t i, nfsdcnt;
    397 	int reregister;
    398 	int tcpflag, udpflag;
    399 	int ip6flag, ip4flag;
    400 	int s, compat;
    401 	int parent_fd = -1;
    402 
    403 #define	DEFNFSDCNT	 4
    404 	nfsdcnt = DEFNFSDCNT;
    405 	compat = reregister = 0;
    406 	tcpflag = udpflag = 1;
    407 	ip6flag = ip4flag = 1;
    408 #define	GETOPT	"46n:rtu"
    409 #define	USAGE	"[-46rtu] [-n num_servers]"
    410 	while ((ch = getopt(argc, argv, GETOPT)) != -1) {
    411 		switch (ch) {
    412 		case '6':
    413 			ip6flag = 1;
    414 			ip4flag = 0;
    415 			s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    416 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    417 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    418 				ip6flag = 0;
    419 			else
    420 				close(s);
    421 			break;
    422 		case '4':
    423 			ip6flag = 0;
    424 			ip4flag = 1;
    425 			s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    426 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    427 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    428 				ip4flag = 0;
    429 			else
    430 				close(s);
    431 			break;
    432 		case 'n':
    433 			nfsdcnt = atoi(optarg);
    434 			if (nfsdcnt < 1) {
    435 				warnx("nfsd count %zu; reset to %d", nfsdcnt,
    436 				    DEFNFSDCNT);
    437 				nfsdcnt = DEFNFSDCNT;
    438 			}
    439 			break;
    440 		case 'r':
    441 			reregister = 1;
    442 			break;
    443 		case 't':
    444 			compat |= 2;
    445 			tcpflag = 1;
    446 			udpflag = 0;
    447 			break;
    448 		case 'u':
    449 			compat |= 1;
    450 			tcpflag = 0;
    451 			udpflag = 1;
    452 			break;
    453 		default:
    454 		case '?':
    455 			usage();
    456 		}
    457 	}
    458 	argv += optind;
    459 	argc -= optind;
    460 
    461 	if (compat == 3) {
    462 		warnx("Old -tu options detected; enabling both udp and tcp.");
    463 		warnx("This is the default behavior now and you can remove");
    464 		warnx("all options.");
    465 		tcpflag = udpflag = 1;
    466 		if (ip6flag == 1 && ip4flag == 0)
    467 			ip4flag = 1;
    468 	}
    469 
    470 	if (debug == 0) {
    471 		parent_fd = daemon2_fork();
    472 	}
    473 
    474 	openlog("nfsd", LOG_PID, LOG_DAEMON);
    475 
    476 	for (i = 0; i < __arraycount(cfg); i++) {
    477 		if (ip4flag == 0 && cfg_family[i] == PF_INET)
    478 			continue;
    479 		if (ip6flag == 0 && cfg_family[i] == PF_INET6)
    480 			continue;
    481 		if (tcpflag == 0 && cfg_protocol[i] == IPPROTO_TCP)
    482 			continue;
    483 		if (udpflag == 0 && cfg_protocol[i] == IPPROTO_UDP)
    484 			continue;
    485 		tryconf(&cfg[i], i, reregister);
    486 	}
    487 
    488 	for (i = 0; i < nfsdcnt; i++) {
    489 		pthread_t t;
    490 		int error;
    491 
    492 		error = pthread_create(&t, NULL, worker, NULL);
    493 		if (error) {
    494 			errno = error;
    495 			syslog(LOG_ERR, "pthread_create: %m");
    496 			exit(1);
    497 		}
    498 	}
    499 
    500 	connect_type_cnt = 0;
    501 	for (i = 0; i < __arraycount(cfg); i++) {
    502 		set[i].fd = -1;
    503 		set[i].events = POLLIN;
    504 		set[i].revents = 0;
    505 
    506 		if (cfg[i].nc == NULL)
    507 			continue;
    508 
    509 		setupsock(&cfg[i], &set[i], i);
    510 		if (set[i].fd != -1)
    511 			connect_type_cnt++;
    512 
    513 	}
    514 
    515 	if (connect_type_cnt == 0)
    516 		exit(0);
    517 
    518 	pthread_setname_np(pthread_self(), "master", NULL);
    519 
    520 	if (debug == 0) {
    521 		daemon2_detach(parent_fd, 0, 0);
    522 		(void)signal(SIGHUP, SIG_IGN);
    523 		(void)signal(SIGINT, SIG_IGN);
    524 		(void)signal(SIGQUIT, SIG_IGN);
    525 		(void)signal(SIGSYS, nonfs);
    526 	}
    527 
    528 	/*
    529 	 * Loop forever accepting connections and passing the sockets
    530 	 * into the kernel for the mounts.
    531 	 */
    532 	for (;;) {
    533 		if (poll(set, __arraycount(set), INFTIM) == -1) {
    534 			syslog(LOG_ERR, "poll failed: %m");
    535 			exit(1);
    536 		}
    537 
    538 		for (i = 0; i < __arraycount(set); i++) {
    539 			struct nfsd_args nfsdargs;
    540 			struct sockaddr_storage ss;
    541 			socklen_t len;
    542 			int msgsock;
    543 			int on = 1;
    544 
    545 			if ((set[i].revents & POLLIN) == 0)
    546 				continue;
    547 			len = sizeof(ss);
    548 			if ((msgsock = accept(set[i].fd,
    549 			    (struct sockaddr *)&ss, &len)) == -1) {
    550 				int serrno = errno;
    551 				syslog(LOG_ERR, "accept failed: %m");
    552 				if (serrno == EINTR || serrno == ECONNABORTED)
    553 					continue;
    554 				exit(1);
    555 			}
    556 			if (setsockopt(msgsock, SOL_SOCKET, SO_KEEPALIVE, &on,
    557 			    sizeof(on)) == -1)
    558 				syslog(LOG_ERR, "setsockopt SO_KEEPALIVE: %m");
    559 			nfsdargs.sock = msgsock;
    560 			nfsdargs.name = (void *)&ss;
    561 			nfsdargs.namelen = len;
    562 			nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
    563 			(void)close(msgsock);
    564 		}
    565 	}
    566 }
    567 
    568 static void
    569 usage(void)
    570 {
    571 	(void)fprintf(stderr, "Usage: %s %s\n", getprogname(), USAGE);
    572 	exit(1);
    573 }
    574 
    575 static void
    576 nonfs(int signo)
    577 {
    578 	syslog(LOG_ERR, "missing system call: NFS not available.");
    579 }
    580