1/*-
2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. Berkeley Software Design Inc's name may not be used to endorse or
13 *    promote products derived from this software without specific prior
14 *    written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *      from BSDI kern.c,v 1.2 1998/11/25 22:38:27 don Exp
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD$");
33
34#include <sys/param.h>
35#include <sys/mount.h>
36#include <sys/queue.h>
37#include <sys/socket.h>
38#include <sys/stat.h>
39
40#include <netinet/in.h>
41#include <arpa/inet.h>
42
43#include <err.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <paths.h>
47#include <pwd.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <syslog.h>
52#include <unistd.h>
53#include <netdb.h>
54
55#include "nlm_prot.h"
56#include <nfs/nfsproto.h>
57#include <nfs/nfs_lock.h>
58
59#include "lockd.h"
60#include "lockd_lock.h"
61#include <nfsclient/nfs.h>
62
63#define DAEMON_USERNAME	"daemon"
64
65/* Lock request owner. */
66typedef struct __owner {
67	pid_t	 pid;				/* Process ID. */
68	time_t	 tod;				/* Time-of-day. */
69} OWNER;
70static OWNER owner;
71
72static char hostname[MAXHOSTNAMELEN + 1];	/* Hostname. */
73static int devfd;
74
75static void	client_cleanup(void);
76static const char *from_addr(struct sockaddr *);
77int	lock_request(LOCKD_MSG *);
78static void	set_auth(CLIENT *cl, struct xucred *ucred);
79void	show(LOCKD_MSG *);
80int	test_request(LOCKD_MSG *);
81int	unlock_request(LOCKD_MSG *);
82
83static int
84nfslockdans(int vers, struct lockd_ans *ansp)
85{
86
87	ansp->la_vers = vers;
88	return (write(devfd, ansp, sizeof *ansp) <= 0);
89}
90
91/*
92 * will break because fifo needs to be repopened when EOF'd
93 */
94#define lockd_seteuid(uid)	seteuid(uid)
95
96#define d_calls (debug_level > 1)
97#define d_args (debug_level > 2)
98
99static const char *
100from_addr(saddr)
101	struct sockaddr *saddr;
102{
103	static char inet_buf[INET6_ADDRSTRLEN];
104
105	if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf),
106			NULL, 0, NI_NUMERICHOST) == 0)
107		return inet_buf;
108	return "???";
109}
110
111void
112client_cleanup(void)
113{
114	(void)lockd_seteuid(0);
115	exit(-1);
116}
117
118/*
119 * client_request --
120 *	Loop around messages from the kernel, forwarding them off to
121 *	NLM servers.
122 */
123pid_t
124client_request(void)
125{
126	LOCKD_MSG msg;
127	int nr, ret;
128	pid_t child;
129	uid_t daemon_uid;
130	struct passwd *pw;
131
132	/* Open the dev . */
133	devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK);
134	if (devfd < 0) {
135		syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV);
136		goto err;
137	}
138
139	signal(SIGPIPE, SIG_IGN);
140
141	/*
142	 * Create a separate process, the client code is really a separate
143	 * daemon that shares a lot of code.
144	 */
145	switch (child = fork()) {
146	case -1:
147		err(1, "fork");
148	case 0:
149		setproctitle("client");
150		break;
151	default:
152		setproctitle("server");
153		return (child);
154	}
155
156	signal(SIGHUP, (sig_t)client_cleanup);
157	signal(SIGTERM, (sig_t)client_cleanup);
158
159	/* Setup. */
160	(void)time(&owner.tod);
161	owner.pid = getpid();
162	(void)gethostname(hostname, sizeof(hostname) - 1);
163
164	pw = getpwnam(DAEMON_USERNAME);
165	if (pw == NULL) {
166		syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME);
167		goto err;
168	}
169	daemon_uid = pw->pw_uid;
170	/* drop our root priviledges */
171	(void)lockd_seteuid(daemon_uid);
172
173	for (;;) {
174		/* Read the fixed length message. */
175		if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) {
176			if (d_args)
177				show(&msg);
178
179			if (msg.lm_version != LOCKD_MSG_VERSION) {
180				syslog(LOG_ERR,
181				    "unknown msg type: %d", msg.lm_version);
182			}
183			/*
184			 * Send it to the NLM server and don't grant the lock
185			 * if we fail for any reason.
186			 */
187			switch (msg.lm_fl.l_type) {
188			case F_RDLCK:
189			case F_WRLCK:
190				if (msg.lm_getlk)
191					ret = test_request(&msg);
192				else
193					ret = lock_request(&msg);
194				break;
195			case F_UNLCK:
196				ret = unlock_request(&msg);
197				break;
198			default:
199				ret = 1;
200				syslog(LOG_ERR,
201				    "unknown lock type: %d", msg.lm_fl.l_type);
202				break;
203			}
204			if (ret) {
205				struct lockd_ans ans;
206
207				ans.la_msg_ident = msg.lm_msg_ident;
208				ans.la_errno = EHOSTUNREACH;
209
210				if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
211					syslog((errno == EPIPE ? LOG_INFO :
212						LOG_ERR), "process %lu: %m",
213						(u_long)msg.lm_msg_ident.pid);
214				}
215			}
216		} else if (nr == -1) {
217			if (errno != EAGAIN) {
218				syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV);
219				goto err;
220			}
221		} else if (nr != 0) {
222			syslog(LOG_ERR,
223			    "%s: discard %d bytes", _PATH_NFSLCKDEV, nr);
224		}
225	}
226
227	/* Reached only on error. */
228err:
229	(void)lockd_seteuid(0);
230	_exit (1);
231}
232
233void
234set_auth(cl, xucred)
235	CLIENT *cl;
236	struct xucred *xucred;
237{
238	int ngroups;
239
240	ngroups = xucred->cr_ngroups - 1;
241	if (ngroups > NGRPS)
242		ngroups = NGRPS;
243        if (cl->cl_auth != NULL)
244                cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth);
245        cl->cl_auth = authunix_create(hostname,
246                        xucred->cr_uid,
247                        xucred->cr_groups[0],
248                        ngroups,
249                        &xucred->cr_groups[1]);
250}
251
252
253/*
254 * test_request --
255 *	Convert a lock LOCKD_MSG into an NLM request, and send it off.
256 */
257int
258test_request(LOCKD_MSG *msg)
259{
260	CLIENT *cli;
261	struct timeval timeout = {0, 0};	/* No timeout, no response. */
262	char dummy;
263
264	if (d_calls)
265		syslog(LOG_DEBUG, "test request: %s: %s to %s",
266		    msg->lm_nfsv3 ? "V4" : "V1/3",
267		    msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
268		    from_addr((struct sockaddr *)&msg->lm_addr));
269
270	if (msg->lm_nfsv3) {
271		struct nlm4_testargs arg4;
272
273		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
274		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
275		arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
276		arg4.alock.caller_name = hostname;
277		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
278		arg4.alock.fh.n_len = msg->lm_fh_len;
279		arg4.alock.oh.n_bytes = (char *)&owner;
280		arg4.alock.oh.n_len = sizeof(owner);
281		arg4.alock.svid = msg->lm_msg_ident.pid;
282		arg4.alock.l_offset = msg->lm_fl.l_start;
283		arg4.alock.l_len = msg->lm_fl.l_len;
284
285		if ((cli = get_client(
286		    (struct sockaddr *)&msg->lm_addr,
287		    NLM_VERS4)) == NULL)
288			return (1);
289
290		set_auth(cli, &msg->lm_cred);
291		(void)clnt_call(cli, NLM_TEST_MSG,
292		    (xdrproc_t)xdr_nlm4_testargs, &arg4,
293		    (xdrproc_t)xdr_void, &dummy, timeout);
294	} else {
295		struct nlm_testargs arg;
296
297		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
298		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
299		arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
300		arg.alock.caller_name = hostname;
301		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
302		arg.alock.fh.n_len = msg->lm_fh_len;
303		arg.alock.oh.n_bytes = (char *)&owner;
304		arg.alock.oh.n_len = sizeof(owner);
305		arg.alock.svid = msg->lm_msg_ident.pid;
306		arg.alock.l_offset = msg->lm_fl.l_start;
307		arg.alock.l_len = msg->lm_fl.l_len;
308
309		if ((cli = get_client(
310		    (struct sockaddr *)&msg->lm_addr,
311		    NLM_VERS)) == NULL)
312			return (1);
313
314		set_auth(cli, &msg->lm_cred);
315		(void)clnt_call(cli, NLM_TEST_MSG,
316		    (xdrproc_t)xdr_nlm_testargs, &arg,
317		    (xdrproc_t)xdr_void, &dummy, timeout);
318	}
319	return (0);
320}
321
322/*
323 * lock_request --
324 *	Convert a lock LOCKD_MSG into an NLM request, and send it off.
325 */
326int
327lock_request(LOCKD_MSG *msg)
328{
329	CLIENT *cli;
330	struct nlm4_lockargs arg4;
331	struct nlm_lockargs arg;
332	struct timeval timeout = {0, 0};	/* No timeout, no response. */
333	char dummy;
334
335	if (d_calls)
336		syslog(LOG_DEBUG, "lock request: %s: %s to %s",
337		    msg->lm_nfsv3 ? "V4" : "V1/3",
338		    msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
339		    from_addr((struct sockaddr *)&msg->lm_addr));
340
341	if (msg->lm_nfsv3) {
342		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
343		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
344		arg4.block = msg->lm_wait ? 1 : 0;
345		arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
346		arg4.alock.caller_name = hostname;
347		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
348		arg4.alock.fh.n_len = msg->lm_fh_len;
349		arg4.alock.oh.n_bytes = (char *)&owner;
350		arg4.alock.oh.n_len = sizeof(owner);
351		arg4.alock.svid = msg->lm_msg_ident.pid;
352		arg4.alock.l_offset = msg->lm_fl.l_start;
353		arg4.alock.l_len = msg->lm_fl.l_len;
354		arg4.reclaim = 0;
355		arg4.state = nsm_state;
356
357		if ((cli = get_client(
358		    (struct sockaddr *)&msg->lm_addr,
359		    NLM_VERS4)) == NULL)
360			return (1);
361
362		set_auth(cli, &msg->lm_cred);
363		(void)clnt_call(cli, NLM_LOCK_MSG,
364		    (xdrproc_t)xdr_nlm4_lockargs, &arg4,
365		    (xdrproc_t)xdr_void, &dummy, timeout);
366	} else {
367		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
368		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
369		arg.block = msg->lm_wait ? 1 : 0;
370		arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
371		arg.alock.caller_name = hostname;
372		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
373		arg.alock.fh.n_len = msg->lm_fh_len;
374		arg.alock.oh.n_bytes = (char *)&owner;
375		arg.alock.oh.n_len = sizeof(owner);
376		arg.alock.svid = msg->lm_msg_ident.pid;
377		arg.alock.l_offset = msg->lm_fl.l_start;
378		arg.alock.l_len = msg->lm_fl.l_len;
379		arg.reclaim = 0;
380		arg.state = nsm_state;
381
382		if ((cli = get_client(
383		    (struct sockaddr *)&msg->lm_addr,
384		    NLM_VERS)) == NULL)
385			return (1);
386
387		set_auth(cli, &msg->lm_cred);
388		(void)clnt_call(cli, NLM_LOCK_MSG,
389		    (xdrproc_t)xdr_nlm_lockargs, &arg,
390		    (xdrproc_t)xdr_void, &dummy, timeout);
391	}
392	return (0);
393}
394
395/*
396 * unlock_request --
397 *	Convert an unlock LOCKD_MSG into an NLM request, and send it off.
398 */
399int
400unlock_request(LOCKD_MSG *msg)
401{
402	CLIENT *cli;
403	struct nlm4_unlockargs arg4;
404	struct nlm_unlockargs arg;
405	struct timeval timeout = {0, 0};	/* No timeout, no response. */
406	char dummy;
407
408	if (d_calls)
409		syslog(LOG_DEBUG, "unlock request: %s: to %s",
410		    msg->lm_nfsv3 ? "V4" : "V1/3",
411		    from_addr((struct sockaddr *)&msg->lm_addr));
412
413	if (msg->lm_nfsv3) {
414		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
415		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
416		arg4.alock.caller_name = hostname;
417		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
418		arg4.alock.fh.n_len = msg->lm_fh_len;
419		arg4.alock.oh.n_bytes = (char *)&owner;
420		arg4.alock.oh.n_len = sizeof(owner);
421		arg4.alock.svid = msg->lm_msg_ident.pid;
422		arg4.alock.l_offset = msg->lm_fl.l_start;
423		arg4.alock.l_len = msg->lm_fl.l_len;
424
425		if ((cli = get_client(
426		    (struct sockaddr *)&msg->lm_addr,
427		    NLM_VERS4)) == NULL)
428			return (1);
429
430		set_auth(cli, &msg->lm_cred);
431		(void)clnt_call(cli, NLM_UNLOCK_MSG,
432		    (xdrproc_t)xdr_nlm4_unlockargs, &arg4,
433		    (xdrproc_t)xdr_void, &dummy, timeout);
434	} else {
435		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
436		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
437		arg.alock.caller_name = hostname;
438		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
439		arg.alock.fh.n_len = msg->lm_fh_len;
440		arg.alock.oh.n_bytes = (char *)&owner;
441		arg.alock.oh.n_len = sizeof(owner);
442		arg.alock.svid = msg->lm_msg_ident.pid;
443		arg.alock.l_offset = msg->lm_fl.l_start;
444		arg.alock.l_len = msg->lm_fl.l_len;
445
446		if ((cli = get_client(
447		    (struct sockaddr *)&msg->lm_addr,
448		    NLM_VERS)) == NULL)
449			return (1);
450
451		set_auth(cli, &msg->lm_cred);
452		(void)clnt_call(cli, NLM_UNLOCK_MSG,
453		    (xdrproc_t)xdr_nlm_unlockargs, &arg,
454		    (xdrproc_t)xdr_void, &dummy, timeout);
455	}
456
457	return (0);
458}
459
460int
461lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version)
462{
463	struct lockd_ans ans;
464
465	if (netcookie->n_len != sizeof(ans.la_msg_ident)) {
466		if (pid == -1) {	/* we're screwed */
467			syslog(LOG_ERR, "inedible nlm cookie");
468			return -1;
469		}
470		ans.la_msg_ident.pid = pid;
471		ans.la_msg_ident.msg_seq = -1;
472	} else {
473		memcpy(&ans.la_msg_ident, netcookie->n_bytes,
474		    sizeof(ans.la_msg_ident));
475	}
476
477	if (d_calls)
478		syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d",
479		    (unsigned long)ans.la_msg_ident.pid,
480		    version == NLM_VERS4 ? "nlmv4" : "nlmv3",
481		    result);
482
483	ans.la_set_getlk_pid = 0;
484	if (version == NLM_VERS4)
485		switch (result) {
486		case nlm4_granted:
487			ans.la_errno = 0;
488			break;
489		default:
490			ans.la_errno = EACCES;
491			break;
492		case nlm4_denied:
493			if (pid_p == NULL)
494				ans.la_errno = EAGAIN;
495			else {
496				/* this is an answer to a nlm_test msg */
497				ans.la_set_getlk_pid = 1;
498				ans.la_getlk_pid = *pid_p;
499				ans.la_errno = 0;
500			}
501			break;
502		case nlm4_denied_nolocks:
503			ans.la_errno = EAGAIN;
504			break;
505		case nlm4_blocked:
506			return -1;
507			/* NOTREACHED */
508		case nlm4_denied_grace_period:
509			ans.la_errno = EAGAIN;
510			break;
511		case nlm4_deadlck:
512			ans.la_errno = EDEADLK;
513			break;
514		case nlm4_rofs:
515			ans.la_errno = EROFS;
516			break;
517		case nlm4_stale_fh:
518			ans.la_errno = ESTALE;
519			break;
520		case nlm4_fbig:
521			ans.la_errno = EFBIG;
522			break;
523		case nlm4_failed:
524			ans.la_errno = EACCES;
525			break;
526		}
527	else
528		switch (result) {
529		case nlm_granted:
530			ans.la_errno = 0;
531			break;
532		default:
533			ans.la_errno = EACCES;
534			break;
535		case nlm_denied:
536			if (pid_p == NULL)
537				ans.la_errno = EAGAIN;
538			else {
539				/* this is an answer to a nlm_test msg */
540				ans.la_set_getlk_pid = 1;
541				ans.la_getlk_pid = *pid_p;
542				ans.la_errno = 0;
543			}
544			break;
545		case nlm_denied_nolocks:
546			ans.la_errno = EAGAIN;
547			break;
548		case nlm_blocked:
549			return -1;
550			/* NOTREACHED */
551		case nlm_denied_grace_period:
552			ans.la_errno = EAGAIN;
553			break;
554		case nlm_deadlck:
555			ans.la_errno = EDEADLK;
556			break;
557		}
558
559	if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
560		syslog(((errno == EPIPE || errno == ESRCH) ?
561			LOG_INFO : LOG_ERR),
562			"process %lu: %m", (u_long)ans.la_msg_ident.pid);
563		return -1;
564	}
565	return 0;
566}
567
568/*
569 * show --
570 *	Display the contents of a kernel LOCKD_MSG structure.
571 */
572void
573show(LOCKD_MSG *mp)
574{
575	static char hex[] = "0123456789abcdef";
576	struct fid *fidp;
577	fsid_t *fsidp;
578	size_t len;
579	u_int8_t *p, *t, buf[NFS_SMALLFH*3+1];
580
581	syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid);
582
583	fsidp = (fsid_t *)&mp->lm_fh;
584	fidp = (struct fid *)((u_int8_t *)&mp->lm_fh + sizeof(fsid_t));
585
586	for (t = buf, p = (u_int8_t *)mp->lm_fh,
587	    len = mp->lm_fh_len;
588	    len > 0; ++p, --len) {
589		*t++ = '\\';
590		*t++ = hex[(*p & 0xf0) >> 4];
591		*t++ = hex[*p & 0x0f];
592	}
593	*t = '\0';
594
595	syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf);
596
597	/* Show flock structure. */
598	syslog(LOG_DEBUG, "start %qu; len %qu; pid %lu; type %d; whence %d\n",
599	    (unsigned long long)mp->lm_fl.l_start,
600	    (unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid,
601	    mp->lm_fl.l_type, mp->lm_fl.l_whence);
602
603	/* Show wait flag. */
604	syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set");
605}
606