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