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nfsd.c revision 1.65 
      1 /*	$NetBSD: nfsd.c,v 1.65 2015/12/23 18:41:54 christos 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 1.65 2015/12/23 18:41:54 christos 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 #ifdef NFSD_RUMP
     84 #include <rump/rump.h>
     85 #include <rump/rump_syscalls.h>
     86 
     87 #define nfssvc(a, b) rump_sys_nfssvc((a), (b))
     88 #define close(a)	rump_sys_close(a)
     89 #define poll(a, b, c) rump_sys_poll((a), (b), (c))
     90 #if 0
     91 #define socket(a, b, c) rump_sys_socket((a), (b), (c))
     92 #define setsockopt(a, b, c, d, e) rump_sys_setsockopt((a), (b), (c), (d), (e))
     93 #define bind(a, b, c) rump_sys_bind((a), (b), (c))
     94 #define listen(a, b) rump_sys_listen((a), (b))
     95 #define accept(a, b, c) rump_sys_accept((a), (b), (c))
     96 #endif
     97 #define main nfsd_main
     98 int nfsd_main(int, char *[]);
     99 #endif
    100 
    101 /* Global defs */
    102 #if defined(DEBUG) || defined(NFSD_RUMP)
    103 #define	syslog(e, s, args...)						\
    104 do {									\
    105     fprintf(stderr,(s), ## args);					\
    106     fprintf(stderr, "\n");						\
    107 } while (/*CONSTCOND*/0)
    108 static int	debug = 1;
    109 #else
    110 static int	debug = 0;
    111 #endif
    112 
    113 static void	nonfs(int);
    114 __dead static void	usage(void);
    115 
    116 static void *
    117 worker(void *dummy)
    118 {
    119 	struct	nfsd_srvargs nsd;
    120 	int nfssvc_flag;
    121 
    122 	pthread_setname_np(pthread_self(), "slave", NULL);
    123 	nfssvc_flag = NFSSVC_NFSD;
    124 	memset(&nsd, 0, sizeof(nsd));
    125 	while (nfssvc(nfssvc_flag, &nsd) < 0) {
    126 		if (errno != ENEEDAUTH) {
    127 			syslog(LOG_ERR, "nfssvc: %s", strerror(errno));
    128 			exit(1);
    129 		}
    130 		nfssvc_flag = NFSSVC_NFSD | NFSSVC_AUTHINFAIL;
    131 	}
    132 
    133 	return NULL;
    134 }
    135 
    136 struct conf {
    137 	struct addrinfo *ai;
    138 	struct netconfig *nc;
    139 	struct netbuf nb;
    140 	struct pollfd pfd;
    141 };
    142 
    143 #define NFS_UDP4	0
    144 #define NFS_TCP4	1
    145 #define NFS_UDP6	2
    146 #define NFS_TCP6	3
    147 
    148 static int cfg_family[] = { PF_INET, PF_INET, PF_INET6, PF_INET6 };
    149 static const char *cfg_netconf[] = { "udp", "tcp", "udp6", "tcp6" };
    150 static int cfg_socktype[] = {
    151     SOCK_DGRAM, SOCK_STREAM, SOCK_DGRAM, SOCK_STREAM };
    152 static int cfg_protocol[] = {
    153     IPPROTO_UDP, IPPROTO_TCP, IPPROTO_UDP, IPPROTO_TCP };
    154 
    155 static int
    156 tryconf(struct conf *cfg, int t, int reregister)
    157 {
    158 	struct addrinfo hints;
    159 	int ecode;
    160 
    161 	memset(&hints, 0, sizeof hints);
    162 	hints.ai_flags = AI_PASSIVE;
    163 	hints.ai_family = cfg_family[t];
    164 	hints.ai_socktype = cfg_socktype[t];
    165 	hints.ai_protocol = cfg_protocol[t];
    166 
    167 	ecode = getaddrinfo(NULL, "nfs", &hints, &cfg->ai);
    168 	if (ecode != 0) {
    169 		syslog(LOG_ERR, "getaddrinfo %s: %s", cfg_netconf[t],
    170 		    gai_strerror(ecode));
    171 		return -1;
    172 	}
    173 
    174 	cfg->nc = getnetconfigent(cfg_netconf[t]);
    175 
    176 	if (cfg->nc == NULL) {
    177 		syslog(LOG_ERR, "getnetconfigent %s failed: %s",
    178 		    cfg_netconf[t], strerror(errno));
    179 		goto out;
    180 	}
    181 
    182 	cfg->nb.buf = cfg->ai->ai_addr;
    183 	cfg->nb.len = cfg->nb.maxlen = cfg->ai->ai_addrlen;
    184 	if (reregister)
    185 		if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb)) {
    186 			syslog(LOG_ERR, "rpcb_set %s failed", cfg_netconf[t]);
    187 			goto out1;
    188 		}
    189 	return 0;
    190 out1:
    191 	freenetconfigent(cfg->nc);
    192 	cfg->nc = NULL;
    193 out:
    194 	freeaddrinfo(cfg->ai);
    195 	cfg->ai = NULL;
    196 	return -1;
    197 }
    198 
    199 static int
    200 setupsock(struct conf *cfg, struct pollfd *set, int p)
    201 {
    202 	int sock;
    203 	struct nfsd_args nfsdargs;
    204 	struct addrinfo *ai = cfg->ai;
    205 	int on = 1;
    206 
    207 	sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    208 
    209 	if (sock == -1) {
    210 		syslog(LOG_ERR, "can't create %s socket: %s", cfg_netconf[p],
    211 		    strerror(errno));
    212 		return -1;
    213 	}
    214 	if (cfg_family[p] == PF_INET6) {
    215 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on,
    216 		    sizeof(on)) == -1) {
    217 			syslog(LOG_ERR, "can't set v6-only binding for %s "
    218 			    "socket: %s", cfg_netconf[p], strerror(errno));
    219 			goto out;
    220 		}
    221 	}
    222 
    223 	if (cfg_protocol[p] == IPPROTO_TCP) {
    224 		if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
    225 		    sizeof(on)) == -1) {
    226 			syslog(LOG_ERR, "setsockopt SO_REUSEADDR for %s: %s",
    227 			    cfg_netconf[p], strerror(errno));
    228 			goto out;
    229 		}
    230 	}
    231 
    232 	if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
    233 		syslog(LOG_ERR, "can't bind %s addr: %s", cfg_netconf[p],
    234 		    strerror(errno));
    235 		goto out;
    236 	}
    237 
    238 	if (cfg_protocol[p] == IPPROTO_TCP) {
    239 		if (listen(sock, 5) == -1) {
    240 			syslog(LOG_ERR, "listen failed");
    241 			goto out;
    242 		}
    243 	}
    244 
    245 	if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb) ||
    246 	    !rpcb_set(RPCPROG_NFS, 3, cfg->nc, &cfg->nb)) {
    247 		syslog(LOG_ERR, "can't register with %s portmap",
    248 		    cfg_netconf[p]);
    249 		goto out;
    250 	}
    251 
    252 
    253 	if (cfg_protocol[p] == IPPROTO_TCP)
    254 		set->fd = sock;
    255 	else {
    256 		nfsdargs.sock = sock;
    257 		nfsdargs.name = NULL;
    258 		nfsdargs.namelen = 0;
    259 		if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
    260 			syslog(LOG_ERR, "can't add %s socket: %s",
    261 			    cfg_netconf[p], strerror(errno));
    262 			goto out;
    263 		}
    264 		(void)close(sock);
    265 	}
    266 	return 0;
    267 out:
    268 	(void)close(sock);
    269 	return -1;
    270 }
    271 
    272 /*
    273  * The functions daemon2_fork() and daemon2_detach() below provide
    274  * functionality similar to daemon(3) but split into two phases.
    275  * daemon2_fork() is called early, before creating resources that
    276  * cannot be inherited across a fork, such as threads or kqueues.
    277  * When the daemon is ready to provide service, daemon2_detach()
    278  * is called to complete the daemonization and signal the parent
    279  * process to exit.
    280  *
    281  * These functions could potentially be moved to a library and
    282  * shared by other daemons.
    283  *
    284  * The return value from daemon2_fork() is a file descriptor to
    285  * be passed as the first argument to daemon2_detach().
    286  */
    287 
    288 static int
    289 daemon2_fork(void)
    290 {
    291 	 int i;
    292 	 int fd;
    293 	 int r;
    294 	 pid_t pid;
    295 	 int detach_msg_pipe[2];
    296 
    297 	 /*
    298 	  * Set up a pipe for signalling the parent, making sure the
    299 	  * write end does not get allocated one of the file
    300 	  * descriptors that may be closed in daemon2_detach().  The
    301 	  * read end does not need such protection.
    302 	  */
    303 	 for (i = 0; i < 3; i++) {
    304 		 r = pipe2(detach_msg_pipe, O_CLOEXEC|O_NOSIGPIPE);
    305 		 if (r < 0)
    306 			 return -1;
    307 		 if (detach_msg_pipe[1] <= STDERR_FILENO &&
    308 		     (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    309 			 (void)dup2(fd, detach_msg_pipe[0]);
    310 			 (void)dup2(fd, detach_msg_pipe[1]);
    311 			 if (fd > STDERR_FILENO)
    312 				 (void)close(fd);
    313 			 continue;
    314 		 }
    315 		 break;
    316 	 }
    317 
    318 	 pid = fork();
    319 	 switch (pid) {
    320 	 case -1:
    321 		 return -1;
    322 	 case 0:
    323 		 /* child */
    324 		 (void)close(detach_msg_pipe[0]);
    325 		 return detach_msg_pipe[1];
    326 	 default:
    327 		 break;
    328 	}
    329 
    330 	/* Parent */
    331 	(void)close(detach_msg_pipe[1]);
    332 
    333 	for (;;) {
    334 		ssize_t nread;
    335 		char dummy;
    336 		nread = read(detach_msg_pipe[0], &dummy, 1);
    337 		if (nread < 0) {
    338 			if (errno == EINTR)
    339 				continue;
    340 			_exit(1);
    341 		} else if (nread == 0) {
    342 			_exit(1);
    343 		} else { /* nread > 0 */
    344 			_exit(0);
    345 		}
    346 	}
    347 }
    348 
    349 static int
    350 daemon2_detach(int parentfd, int nochdir, int noclose)
    351 {
    352 	int fd;
    353 
    354 	if (setsid() == -1)
    355 		return -1;
    356 
    357 	if (!nochdir)
    358 		(void)chdir("/");
    359 
    360 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    361 		(void)dup2(fd, STDIN_FILENO);
    362 		(void)dup2(fd, STDOUT_FILENO);
    363 		(void)dup2(fd, STDERR_FILENO);
    364 		if (fd > STDERR_FILENO)
    365 			(void)close(fd);
    366 	}
    367 
    368 	while (1) {
    369 		ssize_t r = write(parentfd, "", 1);
    370 		if (r < 0) {
    371 			if (errno == EINTR)
    372 				continue;
    373 			else if (errno == EPIPE)
    374 				break;
    375 			else
    376 				return -1;
    377 		} else if (r == 0) {
    378 			/* Should not happen */
    379 			return -1;
    380 		} else {
    381 			break;
    382 		}
    383 	}
    384 
    385 	(void)close(parentfd);
    386 
    387 	return 0;
    388 }
    389 
    390 /*
    391  * Nfs server daemon mostly just a user context for nfssvc()
    392  *
    393  * 1 - do file descriptor and signal cleanup
    394  * 2 - create the nfsd thread(s)
    395  * 3 - create server socket(s)
    396  * 4 - register socket with portmap
    397  *
    398  * For connectionless protocols, just pass the socket into the kernel via
    399  * nfssvc().
    400  * For connection based sockets, loop doing accepts. When you get a new
    401  * socket from accept, pass the msgsock into the kernel via nfssvc().
    402  * The arguments are:
    403  *	-r - reregister with portmapper
    404  *	-t - support only tcp nfs clients
    405  *	-u - support only udp nfs clients
    406  *	-n num how many threads to create.
    407  *	-4 - use only ipv4
    408  *	-6 - use only ipv6
    409  */
    410 int
    411 main(int argc, char *argv[])
    412 {
    413 	struct conf cfg[4];
    414 	struct pollfd set[__arraycount(cfg)];
    415 	int ch, connect_type_cnt;
    416 	size_t i, nfsdcnt;
    417 	int reregister;
    418 	int tcpflag, udpflag;
    419 	int ip6flag, ip4flag;
    420 	int s, compat;
    421 	int parent_fd = -1;
    422 
    423 #define	DEFNFSDCNT	 4
    424 	nfsdcnt = DEFNFSDCNT;
    425 	compat = reregister = 0;
    426 	tcpflag = udpflag = 1;
    427 	ip6flag = ip4flag = 1;
    428 #define	GETOPT	"46n:rtu"
    429 #define	USAGE	"[-46rtu] [-n num_servers]"
    430 	while ((ch = getopt(argc, argv, GETOPT)) != -1) {
    431 		switch (ch) {
    432 		case '6':
    433 			ip6flag = 1;
    434 			ip4flag = 0;
    435 			s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    436 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    437 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    438 				ip6flag = 0;
    439 			else
    440 				close(s);
    441 			break;
    442 		case '4':
    443 			ip6flag = 0;
    444 			ip4flag = 1;
    445 			s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    446 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    447 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    448 				ip4flag = 0;
    449 			else
    450 				close(s);
    451 			break;
    452 		case 'n':
    453 			nfsdcnt = atoi(optarg);
    454 			if (nfsdcnt < 1) {
    455 				warnx("nfsd count %zu; reset to %d", nfsdcnt,
    456 				    DEFNFSDCNT);
    457 				nfsdcnt = DEFNFSDCNT;
    458 			}
    459 			break;
    460 		case 'r':
    461 			reregister = 1;
    462 			break;
    463 		case 't':
    464 			compat |= 2;
    465 			tcpflag = 1;
    466 			udpflag = 0;
    467 			break;
    468 		case 'u':
    469 			compat |= 1;
    470 			tcpflag = 0;
    471 			udpflag = 1;
    472 			break;
    473 		default:
    474 		case '?':
    475 			usage();
    476 		}
    477 	}
    478 	argv += optind;
    479 	argc -= optind;
    480 
    481 	if (compat == 3) {
    482 		warnx("Old -tu options detected; enabling both udp and tcp.");
    483 		warnx("This is the default behavior now and you can remove");
    484 		warnx("all options.");
    485 		tcpflag = udpflag = 1;
    486 		if (ip6flag == 1 && ip4flag == 0)
    487 			ip4flag = 1;
    488 	}
    489 
    490 	if (debug == 0) {
    491 		parent_fd = daemon2_fork();
    492 	}
    493 
    494 	openlog("nfsd", LOG_PID, LOG_DAEMON);
    495 
    496 	memset(cfg, 0, sizeof(cfg));
    497 	for (i = 0; i < __arraycount(cfg); i++) {
    498 		if (ip4flag == 0 && cfg_family[i] == PF_INET)
    499 			continue;
    500 		if (ip6flag == 0 && cfg_family[i] == PF_INET6)
    501 			continue;
    502 		if (tcpflag == 0 && cfg_protocol[i] == IPPROTO_TCP)
    503 			continue;
    504 		if (udpflag == 0 && cfg_protocol[i] == IPPROTO_UDP)
    505 			continue;
    506 		tryconf(&cfg[i], i, reregister);
    507 	}
    508 
    509 	for (i = 0; i < nfsdcnt; i++) {
    510 		pthread_t t;
    511 		int error;
    512 
    513 		error = pthread_create(&t, NULL, worker, NULL);
    514 		if (error) {
    515 			errno = error;
    516 			syslog(LOG_ERR, "pthread_create: %s", strerror(errno));
    517 			exit(1);
    518 		}
    519 	}
    520 
    521 	connect_type_cnt = 0;
    522 	for (i = 0; i < __arraycount(cfg); i++) {
    523 		set[i].fd = -1;
    524 		set[i].events = POLLIN;
    525 		set[i].revents = 0;
    526 
    527 		if (cfg[i].nc == NULL)
    528 			continue;
    529 
    530 		setupsock(&cfg[i], &set[i], i);
    531 		if (set[i].fd != -1)
    532 			connect_type_cnt++;
    533 
    534 	}
    535 
    536 	if (connect_type_cnt == 0)
    537 		exit(0);
    538 
    539 	pthread_setname_np(pthread_self(), "master", NULL);
    540 
    541 	if (debug == 0) {
    542 		daemon2_detach(parent_fd, 0, 0);
    543 		(void)signal(SIGHUP, SIG_IGN);
    544 		(void)signal(SIGINT, SIG_IGN);
    545 		(void)signal(SIGQUIT, SIG_IGN);
    546 		(void)signal(SIGSYS, nonfs);
    547 	}
    548 
    549 	/*
    550 	 * Loop forever accepting connections and passing the sockets
    551 	 * into the kernel for the mounts.
    552 	 */
    553 	for (;;) {
    554 		if (poll(set, __arraycount(set), INFTIM) == -1) {
    555 			syslog(LOG_ERR, "poll failed: %s", strerror(errno));
    556 			exit(1);
    557 		}
    558 
    559 		for (i = 0; i < __arraycount(set); i++) {
    560 			struct nfsd_args nfsdargs;
    561 			struct sockaddr_storage ss;
    562 			socklen_t len;
    563 			int msgsock;
    564 			int on = 1;
    565 
    566 			if ((set[i].revents & POLLIN) == 0)
    567 				continue;
    568 			len = sizeof(ss);
    569 			if ((msgsock = accept(set[i].fd,
    570 			    (struct sockaddr *)&ss, &len)) == -1) {
    571 				int serrno = errno;
    572 				syslog(LOG_ERR, "accept failed: %s",
    573 				    strerror(errno));
    574 				if (serrno == EINTR || serrno == ECONNABORTED)
    575 					continue;
    576 				exit(1);
    577 			}
    578 			if (setsockopt(msgsock, SOL_SOCKET, SO_KEEPALIVE, &on,
    579 			    sizeof(on)) == -1)
    580 				syslog(LOG_ERR, "setsockopt SO_KEEPALIVE: %s",
    581 				    strerror(errno));
    582 			nfsdargs.sock = msgsock;
    583 			nfsdargs.name = (void *)&ss;
    584 			nfsdargs.namelen = len;
    585 			nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
    586 			(void)close(msgsock);
    587 		}
    588 	}
    589 }
    590 
    591 static void
    592 usage(void)
    593 {
    594 	(void)fprintf(stderr, "Usage: %s %s\n", getprogname(), USAGE);
    595 	exit(1);
    596 }
    597 
    598 static void
    599 nonfs(int signo)
    600 {
    601 	syslog(LOG_ERR, "missing system call: NFS not available.");
    602 }
    603