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nfsd.c revision 1.69
      1 /*	$NetBSD: nfsd.c,v 1.69 2020/06/17 00:16:22 kamil 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 1.69 2020/06/17 00:16:22 kamil 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_syscallshotgun.h>
     86 #include <rump/rump_syscalls.h>
     87 
     88 #define nfssvc(a, b) rump_sys_nfssvc((a), (b))
     89 #define close(a)	rump_sys_close(a)
     90 #define poll(a, b, c) rump_sys_poll((a), (b), (c))
     91 #if 0
     92 #define socket(a, b, c) rump_sys_socket((a), (b), (c))
     93 #define setsockopt(a, b, c, d, e) rump_sys_setsockopt((a), (b), (c), (d), (e))
     94 #define bind(a, b, c) rump_sys_bind((a), (b), (c))
     95 #define listen(a, b) rump_sys_listen((a), (b))
     96 #define accept(a, b, c) rump_sys_accept((a), (b), (c))
     97 #endif
     98 #define main nfsd_main
     99 int nfsd_main(int, char *[]);
    100 #endif
    101 
    102 /* Global defs */
    103 #if defined(DEBUG) || defined(NFSD_RUMP)
    104 static int	debug = 1;
    105 #else
    106 static int	debug = 0;
    107 #endif
    108 
    109 #define	logit(e, s, args...)						\
    110 do {									\
    111 	if (debug) {							\
    112 		fprintf(stderr,(s), ## args);				\
    113 		fprintf(stderr, "\n");					\
    114 	} else {							\
    115 		syslog(e, s, ## args);					\
    116 	}								\
    117 } while (/*CONSTCOND*/0)
    118 
    119 static void	nonfs(int);
    120 __dead static void	usage(void);
    121 
    122 static void *
    123 worker(void *dummy)
    124 {
    125 	struct	nfsd_srvargs nsd;
    126 	int nfssvc_flag;
    127 
    128 	pthread_setname_np(pthread_self(), "slave", NULL);
    129 	nfssvc_flag = NFSSVC_NFSD;
    130 	memset(&nsd, 0, sizeof(nsd));
    131 	while (nfssvc(nfssvc_flag, &nsd) < 0) {
    132 		if (errno != ENEEDAUTH) {
    133 			logit(LOG_ERR, "nfssvc: %s", strerror(errno));
    134 			exit(1);
    135 		}
    136 		nfssvc_flag = NFSSVC_NFSD | NFSSVC_AUTHINFAIL;
    137 	}
    138 
    139 	return NULL;
    140 }
    141 
    142 struct conf {
    143 	struct addrinfo *ai;
    144 	struct netconfig *nc;
    145 	struct netbuf nb;
    146 	struct pollfd pfd;
    147 };
    148 
    149 #define NFS_UDP4	0
    150 #define NFS_TCP4	1
    151 #define NFS_UDP6	2
    152 #define NFS_TCP6	3
    153 
    154 static int cfg_family[] = { PF_INET, PF_INET, PF_INET6, PF_INET6 };
    155 static const char *cfg_netconf[] = { "udp", "tcp", "udp6", "tcp6" };
    156 static int cfg_socktype[] = {
    157     SOCK_DGRAM, SOCK_STREAM, SOCK_DGRAM, SOCK_STREAM };
    158 static int cfg_protocol[] = {
    159     IPPROTO_UDP, IPPROTO_TCP, IPPROTO_UDP, IPPROTO_TCP };
    160 
    161 static int
    162 tryconf(struct conf *cfg, int t, int reregister)
    163 {
    164 	struct addrinfo hints;
    165 	int ecode;
    166 
    167 	memset(&hints, 0, sizeof hints);
    168 	hints.ai_flags = AI_PASSIVE;
    169 	hints.ai_family = cfg_family[t];
    170 	hints.ai_socktype = cfg_socktype[t];
    171 	hints.ai_protocol = cfg_protocol[t];
    172 
    173 	ecode = getaddrinfo(NULL, "nfs", &hints, &cfg->ai);
    174 	if (ecode != 0) {
    175 		logit(LOG_ERR, "getaddrinfo %s: %s", cfg_netconf[t],
    176 		    gai_strerror(ecode));
    177 		return -1;
    178 	}
    179 
    180 	cfg->nc = getnetconfigent(cfg_netconf[t]);
    181 
    182 	if (cfg->nc == NULL) {
    183 		logit(LOG_ERR, "getnetconfigent %s failed: %s",
    184 		    cfg_netconf[t], strerror(errno));
    185 		goto out;
    186 	}
    187 
    188 	cfg->nb.buf = cfg->ai->ai_addr;
    189 	cfg->nb.len = cfg->nb.maxlen = cfg->ai->ai_addrlen;
    190 	if (reregister)
    191 		if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb)) {
    192 			logit(LOG_ERR, "rpcb_set %s failed", cfg_netconf[t]);
    193 			goto out1;
    194 		}
    195 	return 0;
    196 out1:
    197 	freenetconfigent(cfg->nc);
    198 	cfg->nc = NULL;
    199 out:
    200 	freeaddrinfo(cfg->ai);
    201 	cfg->ai = NULL;
    202 	return -1;
    203 }
    204 
    205 static int
    206 setupsock(struct conf *cfg, struct pollfd *set, int p)
    207 {
    208 	int sock;
    209 	struct nfsd_args nfsdargs;
    210 	struct addrinfo *ai = cfg->ai;
    211 	int on = 1;
    212 
    213 	sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    214 
    215 	if (sock == -1) {
    216 		logit(LOG_ERR, "can't create %s socket: %s", cfg_netconf[p],
    217 		    strerror(errno));
    218 		return -1;
    219 	}
    220 	if (cfg_family[p] == PF_INET6) {
    221 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on,
    222 		    sizeof(on)) == -1) {
    223 			logit(LOG_ERR, "can't set v6-only binding for %s "
    224 			    "socket: %s", cfg_netconf[p], strerror(errno));
    225 			goto out;
    226 		}
    227 	}
    228 
    229 	if (cfg_protocol[p] == IPPROTO_TCP) {
    230 		if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
    231 		    sizeof(on)) == -1) {
    232 			logit(LOG_ERR, "setsockopt SO_REUSEADDR for %s: %s",
    233 			    cfg_netconf[p], strerror(errno));
    234 			goto out;
    235 		}
    236 	}
    237 
    238 	if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
    239 		logit(LOG_ERR, "can't bind %s addr: %s", cfg_netconf[p],
    240 		    strerror(errno));
    241 		goto out;
    242 	}
    243 
    244 	if (cfg_protocol[p] == IPPROTO_TCP) {
    245 		if (listen(sock, 5) == -1) {
    246 			logit(LOG_ERR, "listen failed");
    247 			goto out;
    248 		}
    249 	}
    250 
    251 	if (!rpcb_set(RPCPROG_NFS, 2, cfg->nc, &cfg->nb) ||
    252 	    !rpcb_set(RPCPROG_NFS, 3, cfg->nc, &cfg->nb)) {
    253 		logit(LOG_ERR, "can't register with %s portmap",
    254 		    cfg_netconf[p]);
    255 		goto out;
    256 	}
    257 
    258 
    259 	if (cfg_protocol[p] == IPPROTO_TCP)
    260 		set->fd = sock;
    261 	else {
    262 		nfsdargs.sock = sock;
    263 		nfsdargs.name = NULL;
    264 		nfsdargs.namelen = 0;
    265 		if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
    266 			logit(LOG_ERR, "can't add %s socket: %s",
    267 			    cfg_netconf[p], strerror(errno));
    268 			goto out;
    269 		}
    270 		(void)close(sock);
    271 	}
    272 	return 0;
    273 out:
    274 	(void)close(sock);
    275 	return -1;
    276 }
    277 
    278 /*
    279  * The functions daemon2_fork() and daemon2_detach() below provide
    280  * functionality similar to daemon(3) but split into two phases.
    281  * daemon2_fork() is called early, before creating resources that
    282  * cannot be inherited across a fork, such as threads or kqueues.
    283  * When the daemon is ready to provide service, daemon2_detach()
    284  * is called to complete the daemonization and signal the parent
    285  * process to exit.
    286  *
    287  * These functions could potentially be moved to a library and
    288  * shared by other daemons.
    289  *
    290  * The return value from daemon2_fork() is a file descriptor to
    291  * be passed as the first argument to daemon2_detach().
    292  */
    293 
    294 static int
    295 daemon2_fork(void)
    296 {
    297 	 int i;
    298 	 int fd;
    299 	 int r;
    300 	 pid_t pid;
    301 	 int detach_msg_pipe[2];
    302 
    303 	 /*
    304 	  * Set up a pipe for signalling the parent, making sure the
    305 	  * write end does not get allocated one of the file
    306 	  * descriptors that may be closed in daemon2_detach().  The
    307 	  * read end does not need such protection.
    308 	  */
    309 	 for (i = 0; i < 3; i++) {
    310 		 r = pipe2(detach_msg_pipe, O_CLOEXEC|O_NOSIGPIPE);
    311 		 if (r < 0)
    312 			 return -1;
    313 		 if (detach_msg_pipe[1] <= STDERR_FILENO &&
    314 		     (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    315 			 (void)dup2(fd, detach_msg_pipe[0]);
    316 			 (void)dup2(fd, detach_msg_pipe[1]);
    317 			 if (fd > STDERR_FILENO)
    318 				 (void)close(fd);
    319 			 continue;
    320 		 }
    321 		 break;
    322 	 }
    323 
    324 	 pid = fork();
    325 	 switch (pid) {
    326 	 case -1:
    327 		return -1;
    328 	 case 0:
    329 		/* child */
    330 		(void)close(detach_msg_pipe[0]);
    331 		(void)write(detach_msg_pipe[1], "", 1);
    332 		 return detach_msg_pipe[1];
    333 	 default:
    334 		break;
    335 	}
    336 
    337 	/* Parent */
    338 	(void)close(detach_msg_pipe[1]);
    339 
    340 	for (;;) {
    341 		ssize_t nread;
    342 		char dummy;
    343 		nread = read(detach_msg_pipe[0], &dummy, 1);
    344 		if (nread < 0) {
    345 			if (errno == EINTR)
    346 				continue;
    347 			_exit(1);
    348 		} else if (nread == 0) {
    349 			_exit(1);
    350 		} else { /* nread > 0 */
    351 			_exit(0);
    352 		}
    353 	}
    354 }
    355 
    356 static int
    357 daemon2_detach(int parentfd, int nochdir, int noclose)
    358 {
    359 	int fd;
    360 
    361 	if (setsid() == -1)
    362 		return -1;
    363 
    364 	if (!nochdir)
    365 		(void)chdir("/");
    366 
    367 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
    368 		(void)dup2(fd, STDIN_FILENO);
    369 		(void)dup2(fd, STDOUT_FILENO);
    370 		(void)dup2(fd, STDERR_FILENO);
    371 		if (fd > STDERR_FILENO)
    372 			(void)close(fd);
    373 	}
    374 
    375 	while (1) {
    376 		ssize_t r = write(parentfd, "", 1);
    377 		if (r < 0) {
    378 			if (errno == EINTR)
    379 				continue;
    380 			else if (errno == EPIPE)
    381 				break;
    382 			else
    383 				return -1;
    384 		} else if (r == 0) {
    385 			/* Should not happen */
    386 			return -1;
    387 		} else {
    388 			break;
    389 		}
    390 	}
    391 
    392 	(void)close(parentfd);
    393 
    394 	return 0;
    395 }
    396 
    397 /*
    398  * Nfs server daemon mostly just a user context for nfssvc()
    399  *
    400  * 1 - do file descriptor and signal cleanup
    401  * 2 - create the nfsd thread(s)
    402  * 3 - create server socket(s)
    403  * 4 - register socket with portmap
    404  *
    405  * For connectionless protocols, just pass the socket into the kernel via
    406  * nfssvc().
    407  * For connection based sockets, loop doing accepts. When you get a new
    408  * socket from accept, pass the msgsock into the kernel via nfssvc().
    409  * The arguments are:
    410  *	-r - reregister with portmapper
    411  *	-t - support only tcp nfs clients
    412  *	-u - support only udp nfs clients
    413  *	-n num how many threads to create.
    414  *	-4 - use only ipv4
    415  *	-6 - use only ipv6
    416  */
    417 int
    418 main(int argc, char *argv[])
    419 {
    420 	struct conf cfg[4];
    421 	struct pollfd set[__arraycount(cfg)];
    422 	int ch, connect_type_cnt;
    423 	size_t i, nfsdcnt;
    424 	int reregister;
    425 	int tcpflag, udpflag;
    426 	int ip6flag, ip4flag;
    427 	int s, compat;
    428 	int parent_fd = -1;
    429 	pthread_t *workers;
    430 
    431 #define	DEFNFSDCNT	 4
    432 	nfsdcnt = DEFNFSDCNT;
    433 	compat = reregister = 0;
    434 	tcpflag = udpflag = 1;
    435 	ip6flag = ip4flag = 1;
    436 #define	GETOPT	"46dn:rtu"
    437 #define	USAGE	"[-46drtu] [-n num_servers]"
    438 	while ((ch = getopt(argc, argv, GETOPT)) != -1) {
    439 		switch (ch) {
    440 		case '6':
    441 			ip6flag = 1;
    442 			ip4flag = 0;
    443 			s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    444 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    445 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    446 				ip6flag = 0;
    447 			else
    448 				close(s);
    449 			break;
    450 		case '4':
    451 			ip6flag = 0;
    452 			ip4flag = 1;
    453 			s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    454 			if (s < 0 && (errno == EPROTONOSUPPORT ||
    455 			    errno == EPFNOSUPPORT || errno == EAFNOSUPPORT))
    456 				ip4flag = 0;
    457 			else
    458 				close(s);
    459 			break;
    460 		case 'd':
    461 			debug++;
    462 			break;
    463 		case 'n':
    464 			nfsdcnt = atoi(optarg);
    465 			if (nfsdcnt < 1) {
    466 				warnx("nfsd count %zu; reset to %d", nfsdcnt,
    467 				    DEFNFSDCNT);
    468 				nfsdcnt = DEFNFSDCNT;
    469 			}
    470 			break;
    471 		case 'r':
    472 			reregister = 1;
    473 			break;
    474 		case 't':
    475 			compat |= 2;
    476 			tcpflag = 1;
    477 			udpflag = 0;
    478 			break;
    479 		case 'u':
    480 			compat |= 1;
    481 			tcpflag = 0;
    482 			udpflag = 1;
    483 			break;
    484 		default:
    485 		case '?':
    486 			usage();
    487 		}
    488 	}
    489 	argv += optind;
    490 	argc -= optind;
    491 
    492 	if (compat == 3) {
    493 		warnx("Old -tu options detected; enabling both udp and tcp.");
    494 		warnx("This is the default behavior now and you can remove");
    495 		warnx("all options.");
    496 		tcpflag = udpflag = 1;
    497 		if (ip6flag == 1 && ip4flag == 0)
    498 			ip4flag = 1;
    499 	}
    500 
    501 	if (debug == 0) {
    502 		parent_fd = daemon2_fork();
    503 		if (parent_fd == -1)
    504 			logit(LOG_ERR, "daemon2_fork failed");
    505 		openlog("nfsd", LOG_PID, LOG_DAEMON);
    506 	}
    507 
    508 
    509 	memset(cfg, 0, sizeof(cfg));
    510 	for (i = 0; i < __arraycount(cfg); i++) {
    511 		if (ip4flag == 0 && cfg_family[i] == PF_INET)
    512 			continue;
    513 		if (ip6flag == 0 && cfg_family[i] == PF_INET6)
    514 			continue;
    515 		if (tcpflag == 0 && cfg_protocol[i] == IPPROTO_TCP)
    516 			continue;
    517 		if (udpflag == 0 && cfg_protocol[i] == IPPROTO_UDP)
    518 			continue;
    519 		tryconf(&cfg[i], i, reregister);
    520 	}
    521 
    522 	workers = calloc(nfsdcnt, sizeof(*workers));
    523 	if (workers == NULL) {
    524 		logit(LOG_ERR, "thread alloc %s", strerror(errno));
    525 		exit(1);
    526 	}
    527 
    528 	for (i = 0; i < nfsdcnt; i++) {
    529 		int error;
    530 
    531 		error = pthread_create(&workers[i], NULL, worker, NULL);
    532 		if (error) {
    533 			errno = error;
    534 			logit(LOG_ERR, "pthread_create: %s", strerror(errno));
    535 			exit(1);
    536 		}
    537 	}
    538 
    539 	connect_type_cnt = 0;
    540 	for (i = 0; i < __arraycount(cfg); i++) {
    541 		set[i].fd = -1;
    542 		set[i].events = POLLIN;
    543 		set[i].revents = 0;
    544 
    545 		if (cfg[i].nc == NULL)
    546 			continue;
    547 
    548 		setupsock(&cfg[i], &set[i], i);
    549 		if (set[i].fd != -1)
    550 			connect_type_cnt++;
    551 
    552 	}
    553 
    554 	pthread_setname_np(pthread_self(), "master", NULL);
    555 
    556 	if (debug == 0) {
    557 		daemon2_detach(parent_fd, 0, 0);
    558 		(void)signal(SIGHUP, SIG_IGN);
    559 		(void)signal(SIGINT, SIG_IGN);
    560 		(void)signal(SIGQUIT, SIG_IGN);
    561 		(void)signal(SIGSYS, nonfs);
    562 	}
    563 
    564 	if (connect_type_cnt == 0) {
    565 		for (i = 0; i < nfsdcnt; i++)
    566 			    pthread_join(workers[i], NULL);
    567 		exit(0);
    568 	}
    569 
    570 	/*
    571 	 * Loop forever accepting connections and passing the sockets
    572 	 * into the kernel for the mounts.
    573 	 */
    574 	for (;;) {
    575 		if (poll(set, __arraycount(set), INFTIM) == -1) {
    576 			logit(LOG_ERR, "poll failed: %s", strerror(errno));
    577 			exit(1);
    578 		}
    579 
    580 		for (i = 0; i < __arraycount(set); i++) {
    581 			struct nfsd_args nfsdargs;
    582 			struct sockaddr_storage ss;
    583 			socklen_t len;
    584 			int msgsock;
    585 			int on = 1;
    586 
    587 			if ((set[i].revents & POLLIN) == 0)
    588 				continue;
    589 			len = sizeof(ss);
    590 			if ((msgsock = accept(set[i].fd,
    591 			    (struct sockaddr *)&ss, &len)) == -1) {
    592 				int serrno = errno;
    593 				logit(LOG_ERR, "accept failed: %s",
    594 				    strerror(errno));
    595 				if (serrno == EINTR || serrno == ECONNABORTED)
    596 					continue;
    597 				exit(1);
    598 			}
    599 			if (setsockopt(msgsock, SOL_SOCKET, SO_KEEPALIVE, &on,
    600 			    sizeof(on)) == -1)
    601 				logit(LOG_ERR, "setsockopt SO_KEEPALIVE: %s",
    602 				    strerror(errno));
    603 			nfsdargs.sock = msgsock;
    604 			nfsdargs.name = (void *)&ss;
    605 			nfsdargs.namelen = len;
    606 			nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
    607 			(void)close(msgsock);
    608 		}
    609 	}
    610 }
    611 
    612 static void
    613 usage(void)
    614 {
    615 	(void)fprintf(stderr, "Usage: %s %s\n", getprogname(), USAGE);
    616 	exit(1);
    617 }
    618 
    619 static void
    620 nonfs(int signo)
    621 {
    622 	logit(LOG_ERR, "missing system call: NFS not available.");
    623 }
    624