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nfsd.c revision 1.67 
      1 /*	$NetBSD: nfsd.c,v 1.67 2016/08/22 16:08:51 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 1.67 2016/08/22 16:08:51 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 static int	debug = 1;
    104 #else
    105 static int	debug = 0;
    106 #endif
    107 
    108 #define	logit(e, s, args...)						\
    109 do {									\
    110 	if (debug) {							\
    111 		fprintf(stderr,(s), ## args);				\
    112 		fprintf(stderr, "\n");					\
    113 	} else {							\
    114 		syslog(e, s, ## args);					\
    115 	}								\
    116 } while (/*CONSTCOND*/0)
    117 
    118 static void	nonfs(int);
    119 __dead static void	usage(void);
    120 
    121 static void *
    122 worker(void *dummy)
    123 {
    124 	struct	nfsd_srvargs nsd;
    125 	int nfssvc_flag;
    126 
    127 	pthread_setname_np(pthread_self(), "slave", NULL);
    128 	nfssvc_flag = NFSSVC_NFSD;
    129 	memset(&nsd, 0, sizeof(nsd));
    130 	while (nfssvc(nfssvc_flag, &nsd) < 0) {
    131 		if (errno != ENEEDAUTH) {
    132 			logit(LOG_ERR, "nfssvc: %s", strerror(errno));
    133 			exit(1);
    134 		}
    135 		nfssvc_flag = NFSSVC_NFSD | NFSSVC_AUTHINFAIL;
    136 	}
    137 
    138 	return NULL;
    139 }
    140 
    141 struct conf {
    142 	struct addrinfo *ai;
    143 	struct netconfig *nc;
    144 	struct netbuf nb;
    145 	struct pollfd pfd;
    146 };
    147 
    148 #define NFS_UDP4	0
    149 #define NFS_TCP4	1
    150 #define NFS_UDP6	2
    151 #define NFS_TCP6	3
    152 
    153 static int cfg_family[] = { PF_INET, PF_INET, PF_INET6, PF_INET6 };
    154 static const char *cfg_netconf[] = { "udp", "tcp", "udp6", "tcp6" };
    155 static int cfg_socktype[] = {
    156     SOCK_DGRAM, SOCK_STREAM, SOCK_DGRAM, SOCK_STREAM };
    157 static int cfg_protocol[] = {
    158     IPPROTO_UDP, IPPROTO_TCP, IPPROTO_UDP, IPPROTO_TCP };
    159 
    160 static int
    161 tryconf(struct conf *cfg, int t, int reregister)
    162 {
    163 	struct addrinfo hints;
    164 	int ecode;
    165 
    166 	memset(&hints, 0, sizeof hints);
    167 	hints.ai_flags = AI_PASSIVE;
    168 	hints.ai_family = cfg_family[t];
    169 	hints.ai_socktype = cfg_socktype[t];
    170 	hints.ai_protocol = cfg_protocol[t];
    171 
    172 	ecode = getaddrinfo(NULL, "nfs", &hints, &cfg->ai);
    173 	if (ecode != 0) {
    174 		logit(LOG_ERR, "getaddrinfo %s: %s", cfg_netconf[t],
    175 		    gai_strerror(ecode));
    176 		return -1;
    177 	}
    178 
    179 	cfg->nc = getnetconfigent(cfg_netconf[t]);
    180 
    181 	if (cfg->nc == NULL) {
    182 		logit(LOG_ERR, "getnetconfigent %s failed: %s",
    183 		    cfg_netconf[t], strerror(errno));
    184 		goto out;
    185 	}
    186 
    187 	cfg->nb.buf = cfg->ai->ai_addr;
    188 	cfg->nb.len = cfg->nb.maxlen = cfg->ai->ai_addrlen;
    189 	if (reregister)
    190 		if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb)) {
    191 			logit(LOG_ERR, "rpcb_set %s failed", cfg_netconf[t]);
    192 			goto out1;
    193 		}
    194 	return 0;
    195 out1:
    196 	freenetconfigent(cfg->nc);
    197 	cfg->nc = NULL;
    198 out:
    199 	freeaddrinfo(cfg->ai);
    200 	cfg->ai = NULL;
    201 	return -1;
    202 }
    203 
    204 static int
    205 setupsock(struct conf *cfg, struct pollfd *set, int p)
    206 {
    207 	int sock;
    208 	struct nfsd_args nfsdargs;
    209 	struct addrinfo *ai = cfg->ai;
    210 	int on = 1;
    211 
    212 	sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    213 
    214 	if (sock == -1) {
    215 		logit(LOG_ERR, "can't create %s socket: %s", cfg_netconf[p],
    216 		    strerror(errno));
    217 		return -1;
    218 	}
    219 	if (cfg_family[p] == PF_INET6) {
    220 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on,
    221 		    sizeof(on)) == -1) {
    222 			logit(LOG_ERR, "can't set v6-only binding for %s "
    223 			    "socket: %s", cfg_netconf[p], strerror(errno));
    224 			goto out;
    225 		}
    226 	}
    227 
    228 	if (cfg_protocol[p] == IPPROTO_TCP) {
    229 		if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
    230 		    sizeof(on)) == -1) {
    231 			logit(LOG_ERR, "setsockopt SO_REUSEADDR for %s: %s",
    232 			    cfg_netconf[p], strerror(errno));
    233 			goto out;
    234 		}
    235 	}
    236 
    237 	if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
    238 		logit(LOG_ERR, "can't bind %s addr: %s", cfg_netconf[p],
    239 		    strerror(errno));
    240 		goto out;
    241 	}
    242 
    243 	if (cfg_protocol[p] == IPPROTO_TCP) {
    244 		if (listen(sock, 5) == -1) {
    245 			logit(LOG_ERR, "listen failed");
    246 			goto out;
    247 		}
    248 	}
    249 
    250 	if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb) ||
    251 	    !rpcb_set(RPCPROG_NFS, 3, cfg->nc, &cfg->nb)) {
    252 		logit(LOG_ERR, "can't register with %s portmap",
    253 		    cfg_netconf[p]);
    254 		goto out;
    255 	}
    256 
    257 
    258 	if (cfg_protocol[p] == IPPROTO_TCP)
    259 		set->fd = sock;
    260 	else {
    261 		nfsdargs.sock = sock;
    262 		nfsdargs.name = NULL;
    263 		nfsdargs.namelen = 0;
    264 		if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
    265 			logit(LOG_ERR, "can't add %s socket: %s",
    266 			    cfg_netconf[p], strerror(errno));
    267 			goto out;
    268 		}
    269 		(void)close(sock);
    270 	}
    271 	return 0;
    272 out:
    273 	(void)close(sock);
    274 	return -1;
    275 }
    276 
    277 /*
    278  * The functions daemon2_fork() and daemon2_detach() below provide
    279  * functionality similar to daemon(3) but split into two phases.
    280  * daemon2_fork() is called early, before creating resources that
    281  * cannot be inherited across a fork, such as threads or kqueues.
    282  * When the daemon is ready to provide service, daemon2_detach()
    283  * is called to complete the daemonization and signal the parent
    284  * process to exit.
    285  *
    286  * These functions could potentially be moved to a library and
    287  * shared by other daemons.
    288  *
    289  * The return value from daemon2_fork() is a file descriptor to
    290  * be passed as the first argument to daemon2_detach().
    291  */
    292 
    293 static int
    294 daemon2_fork(void)
    295 {
    296 	 int i;
    297 	 int fd;
    298 	 int r;
    299 	 pid_t pid;
    300 	 int detach_msg_pipe[2];
    301 
    302 	 /*
    303 	  * Set up a pipe for signalling the parent, making sure the
    304 	  * write end does not get allocated one of the file
    305 	  * descriptors that may be closed in daemon2_detach().  The
    306 	  * read end does not need such protection.
    307 	  */
    308 	 for (i = 0; i < 3; i++) {
    309 		 r = pipe2(detach_msg_pipe, O_CLOEXEC|O_NOSIGPIPE);
    310 		 if (r < 0)
    311 			 return -1;
    312 		 if (detach_msg_pipe[1] <= STDERR_FILENO &&
    313 		     (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    314 			 (void)dup2(fd, detach_msg_pipe[0]);
    315 			 (void)dup2(fd, detach_msg_pipe[1]);
    316 			 if (fd > STDERR_FILENO)
    317 				 (void)close(fd);
    318 			 continue;
    319 		 }
    320 		 break;
    321 	 }
    322 
    323 	 pid = fork();
    324 	 switch (pid) {
    325 	 case -1:
    326 		return -1;
    327 	 case 0:
    328 		/* child */
    329 		(void)close(detach_msg_pipe[0]);
    330 		(void)write(detach_msg_pipe[1], "", 1);
    331 		 return detach_msg_pipe[1];
    332 	 default:
    333 		break;
    334 	}
    335 
    336 	/* Parent */
    337 	(void)close(detach_msg_pipe[1]);
    338 
    339 	for (;;) {
    340 		ssize_t nread;
    341 		char dummy;
    342 		nread = read(detach_msg_pipe[0], &dummy, 1);
    343 		if (nread < 0) {
    344 			if (errno == EINTR)
    345 				continue;
    346 			_exit(1);
    347 		} else if (nread == 0) {
    348 			_exit(1);
    349 		} else { /* nread > 0 */
    350 			_exit(0);
    351 		}
    352 	}
    353 }
    354 
    355 static int
    356 daemon2_detach(int parentfd, int nochdir, int noclose)
    357 {
    358 	int fd;
    359 
    360 	if (setsid() == -1)
    361 		return -1;
    362 
    363 	if (!nochdir)
    364 		(void)chdir("/");
    365 
    366 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    367 		(void)dup2(fd, STDIN_FILENO);
    368 		(void)dup2(fd, STDOUT_FILENO);
    369 		(void)dup2(fd, STDERR_FILENO);
    370 		if (fd > STDERR_FILENO)
    371 			(void)close(fd);
    372 	}
    373 
    374 	while (1) {
    375 		ssize_t r = write(parentfd, "", 1);
    376 		if (r < 0) {
    377 			if (errno == EINTR)
    378 				continue;
    379 			else if (errno == EPIPE)
    380 				break;
    381 			else
    382 				return -1;
    383 		} else if (r == 0) {
    384 			/* Should not happen */
    385 			return -1;
    386 		} else {
    387 			break;
    388 		}
    389 	}
    390 
    391 	(void)close(parentfd);
    392 
    393 	return 0;
    394 }
    395 
    396 /*
    397  * Nfs server daemon mostly just a user context for nfssvc()
    398  *
    399  * 1 - do file descriptor and signal cleanup
    400  * 2 - create the nfsd thread(s)
    401  * 3 - create server socket(s)
    402  * 4 - register socket with portmap
    403  *
    404  * For connectionless protocols, just pass the socket into the kernel via
    405  * nfssvc().
    406  * For connection based sockets, loop doing accepts. When you get a new
    407  * socket from accept, pass the msgsock into the kernel via nfssvc().
    408  * The arguments are:
    409  *	-r - reregister with portmapper
    410  *	-t - support only tcp nfs clients
    411  *	-u - support only udp nfs clients
    412  *	-n num how many threads to create.
    413  *	-4 - use only ipv4
    414  *	-6 - use only ipv6
    415  */
    416 int
    417 main(int argc, char *argv[])
    418 {
    419 	struct conf cfg[4];
    420 	struct pollfd set[__arraycount(cfg)];
    421 	int ch, connect_type_cnt;
    422 	size_t i, nfsdcnt;
    423 	int reregister;
    424 	int tcpflag, udpflag;
    425 	int ip6flag, ip4flag;
    426 	int s, compat;
    427 	int parent_fd = -1;
    428 
    429 #define	DEFNFSDCNT	 4
    430 	nfsdcnt = DEFNFSDCNT;
    431 	compat = reregister = 0;
    432 	tcpflag = udpflag = 1;
    433 	ip6flag = ip4flag = 1;
    434 #define	GETOPT	"46dn:rtu"
    435 #define	USAGE	"[-46drtu] [-n num_servers]"
    436 	while ((ch = getopt(argc, argv, GETOPT)) != -1) {
    437 		switch (ch) {
    438 		case '6':
    439 			ip6flag = 1;
    440 			ip4flag = 0;
    441 			s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    442 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    443 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    444 				ip6flag = 0;
    445 			else
    446 				close(s);
    447 			break;
    448 		case '4':
    449 			ip6flag = 0;
    450 			ip4flag = 1;
    451 			s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    452 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    453 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    454 				ip4flag = 0;
    455 			else
    456 				close(s);
    457 			break;
    458 		case 'd':
    459 			debug++;
    460 			break;
    461 		case 'n':
    462 			nfsdcnt = atoi(optarg);
    463 			if (nfsdcnt < 1) {
    464 				warnx("nfsd count %zu; reset to %d", nfsdcnt,
    465 				    DEFNFSDCNT);
    466 				nfsdcnt = DEFNFSDCNT;
    467 			}
    468 			break;
    469 		case 'r':
    470 			reregister = 1;
    471 			break;
    472 		case 't':
    473 			compat |= 2;
    474 			tcpflag = 1;
    475 			udpflag = 0;
    476 			break;
    477 		case 'u':
    478 			compat |= 1;
    479 			tcpflag = 0;
    480 			udpflag = 1;
    481 			break;
    482 		default:
    483 		case '?':
    484 			usage();
    485 		}
    486 	}
    487 	argv += optind;
    488 	argc -= optind;
    489 
    490 	if (compat == 3) {
    491 		warnx("Old -tu options detected; enabling both udp and tcp.");
    492 		warnx("This is the default behavior now and you can remove");
    493 		warnx("all options.");
    494 		tcpflag = udpflag = 1;
    495 		if (ip6flag == 1 && ip4flag == 0)
    496 			ip4flag = 1;
    497 	}
    498 
    499 	if (debug == 0) {
    500 		parent_fd = daemon2_fork();
    501 		if (parent_fd == -1)
    502 			logit(LOG_ERR, "daemon2_fork failed");
    503 		openlog("nfsd", LOG_PID, LOG_DAEMON);
    504 	}
    505 
    506 
    507 	memset(cfg, 0, sizeof(cfg));
    508 	for (i = 0; i < __arraycount(cfg); i++) {
    509 		if (ip4flag == 0 && cfg_family[i] == PF_INET)
    510 			continue;
    511 		if (ip6flag == 0 && cfg_family[i] == PF_INET6)
    512 			continue;
    513 		if (tcpflag == 0 && cfg_protocol[i] == IPPROTO_TCP)
    514 			continue;
    515 		if (udpflag == 0 && cfg_protocol[i] == IPPROTO_UDP)
    516 			continue;
    517 		tryconf(&cfg[i], i, reregister);
    518 	}
    519 
    520 	for (i = 0; i < nfsdcnt; i++) {
    521 		pthread_t t;
    522 		int error;
    523 
    524 		error = pthread_create(&t, NULL, worker, NULL);
    525 		if (error) {
    526 			errno = error;
    527 			logit(LOG_ERR, "pthread_create: %s", strerror(errno));
    528 			exit(1);
    529 		}
    530 	}
    531 
    532 	connect_type_cnt = 0;
    533 	for (i = 0; i < __arraycount(cfg); i++) {
    534 		set[i].fd = -1;
    535 		set[i].events = POLLIN;
    536 		set[i].revents = 0;
    537 
    538 		if (cfg[i].nc == NULL)
    539 			continue;
    540 
    541 		setupsock(&cfg[i], &set[i], i);
    542 		if (set[i].fd != -1)
    543 			connect_type_cnt++;
    544 
    545 	}
    546 
    547 	if (connect_type_cnt == 0)
    548 		exit(0);
    549 
    550 	pthread_setname_np(pthread_self(), "master", NULL);
    551 
    552 	if (debug == 0) {
    553 		daemon2_detach(parent_fd, 0, 0);
    554 		(void)signal(SIGHUP, SIG_IGN);
    555 		(void)signal(SIGINT, SIG_IGN);
    556 		(void)signal(SIGQUIT, SIG_IGN);
    557 		(void)signal(SIGSYS, nonfs);
    558 	}
    559 
    560 	/*
    561 	 * Loop forever accepting connections and passing the sockets
    562 	 * into the kernel for the mounts.
    563 	 */
    564 	for (;;) {
    565 		if (poll(set, __arraycount(set), INFTIM) == -1) {
    566 			logit(LOG_ERR, "poll failed: %s", strerror(errno));
    567 			exit(1);
    568 		}
    569 
    570 		for (i = 0; i < __arraycount(set); i++) {
    571 			struct nfsd_args nfsdargs;
    572 			struct sockaddr_storage ss;
    573 			socklen_t len;
    574 			int msgsock;
    575 			int on = 1;
    576 
    577 			if ((set[i].revents & POLLIN) == 0)
    578 				continue;
    579 			len = sizeof(ss);
    580 			if ((msgsock = accept(set[i].fd,
    581 			    (struct sockaddr *)&ss, &len)) == -1) {
    582 				int serrno = errno;
    583 				logit(LOG_ERR, "accept failed: %s",
    584 				    strerror(errno));
    585 				if (serrno == EINTR || serrno == ECONNABORTED)
    586 					continue;
    587 				exit(1);
    588 			}
    589 			if (setsockopt(msgsock, SOL_SOCKET, SO_KEEPALIVE, &on,
    590 			    sizeof(on)) == -1)
    591 				logit(LOG_ERR, "setsockopt SO_KEEPALIVE: %s",
    592 				    strerror(errno));
    593 			nfsdargs.sock = msgsock;
    594 			nfsdargs.name = (void *)&ss;
    595 			nfsdargs.namelen = len;
    596 			nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
    597 			(void)close(msgsock);
    598 		}
    599 	}
    600 }
    601 
    602 static void
    603 usage(void)
    604 {
    605 	(void)fprintf(stderr, "Usage: %s %s\n", getprogname(), USAGE);
    606 	exit(1);
    607 }
    608 
    609 static void
    610 nonfs(int signo)
    611 {
    612 	logit(LOG_ERR, "missing system call: NFS not available.");
    613 }
    614