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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. */
66 typedef struct __owner {
67         pid_t    pid;                           /* Process ID. */
68         time_t   tod;                           /* Time-of-day. */
69 } OWNER;
70 static OWNER owner;
71
72 static char hostname[MAXHOSTNAMELEN + 1];       /* Hostname. */
73 static int devfd;
74
75 static void     client_cleanup(void);
76 static const char *from_addr(struct sockaddr *);
77 int     lock_request(LOCKD_MSG *);
78 static void     set_auth(CLIENT *cl, struct xucred *ucred);
79 void    show(LOCKD_MSG *);
80 int     test_request(LOCKD_MSG *);
81 int     unlock_request(LOCKD_MSG *);
82
83 static int
84 nfslockdans(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
99 static const char *
100 from_addr(struct sockaddr *saddr)
101 {
102         static char inet_buf[INET6_ADDRSTRLEN];
103
104         if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf),
105                         NULL, 0, NI_NUMERICHOST) == 0)
106                 return inet_buf;
107         return "???";
108 }
109
110 void
111 client_cleanup(void)
112 {
113         (void)lockd_seteuid(0);
114         exit(-1);
115 }
116
117 /*
118  * client_request --
119  *      Loop around messages from the kernel, forwarding them off to
120  *      NLM servers.
121  */
122 pid_t
123 client_request(void)
124 {
125         LOCKD_MSG msg;
126         int nr, ret;
127         pid_t child;
128         uid_t daemon_uid;
129         struct passwd *pw;
130
131         /* Open the dev . */
132         devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK);
133         if (devfd < 0) {
134                 syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV);
135                 goto err;
136         }
137
138         signal(SIGPIPE, SIG_IGN);
139
140         /*
141          * Create a separate process, the client code is really a separate
142          * daemon that shares a lot of code.
143          */
144         switch (child = fork()) {
145         case -1:
146                 err(1, "fork");
147         case 0:
148                 setproctitle("client");
149                 break;
150         default:
151                 setproctitle("server");
152                 return (child);
153         }
154
155         signal(SIGHUP, (sig_t)client_cleanup);
156         signal(SIGTERM, (sig_t)client_cleanup);
157
158         /* Setup. */
159         (void)time(&owner.tod);
160         owner.pid = getpid();
161         (void)gethostname(hostname, sizeof(hostname) - 1);
162
163         pw = getpwnam(DAEMON_USERNAME);
164         if (pw == NULL) {
165                 syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME);
166                 goto err;
167         }
168         daemon_uid = pw->pw_uid;
169         /* drop our root privileges */
170         (void)lockd_seteuid(daemon_uid);
171
172         for (;;) {
173                 /* Read the fixed length message. */
174                 if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) {
175                         if (d_args)
176                                 show(&msg);
177
178                         if (msg.lm_version != LOCKD_MSG_VERSION) {
179                                 syslog(LOG_ERR,
180                                     "unknown msg type: %d", msg.lm_version);
181                         }
182                         /*
183                          * Send it to the NLM server and don't grant the lock
184                          * if we fail for any reason.
185                          */
186                         switch (msg.lm_fl.l_type) {
187                         case F_RDLCK:
188                         case F_WRLCK:
189                                 if (msg.lm_getlk)
190                                         ret = test_request(&msg);
191                                 else
192                                         ret = lock_request(&msg);
193                                 break;
194                         case F_UNLCK:
195                                 ret = unlock_request(&msg);
196                                 break;
197                         default:
198                                 ret = 1;
199                                 syslog(LOG_ERR,
200                                     "unknown lock type: %d", msg.lm_fl.l_type);
201                                 break;
202                         }
203                         if (ret) {
204                                 struct lockd_ans ans;
205
206                                 ans.la_msg_ident = msg.lm_msg_ident;
207                                 ans.la_errno = EHOSTUNREACH;
208
209                                 if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
210                                         syslog((errno == EPIPE ? LOG_INFO : 
211                                                 LOG_ERR), "process %lu: %m",
212                                                 (u_long)msg.lm_msg_ident.pid);
213                                 }
214                         }
215                 } else if (nr == -1) {
216                         if (errno != EAGAIN) {
217                                 syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV);
218                                 goto err;
219                         }
220                 } else if (nr != 0) {
221                         syslog(LOG_ERR,
222                             "%s: discard %d bytes", _PATH_NFSLCKDEV, nr);
223                 }
224         }
225
226         /* Reached only on error. */
227 err:
228         (void)lockd_seteuid(0);
229         _exit (1);
230 }
231
232 void
233 set_auth(CLIENT *cl, struct xucred *xucred)
234 {
235         int ngroups;
236
237         ngroups = xucred->cr_ngroups - 1;
238         if (ngroups > NGRPS)
239                 ngroups = NGRPS;
240         if (cl->cl_auth != NULL)
241                 cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth);
242         cl->cl_auth = authunix_create(hostname,
243                         xucred->cr_uid,
244                         xucred->cr_groups[0],
245                         ngroups,
246                         &xucred->cr_groups[1]);
247 }
248
249
250 /*
251  * test_request --
252  *      Convert a lock LOCKD_MSG into an NLM request, and send it off.
253  */
254 int
255 test_request(LOCKD_MSG *msg)
256 {
257         CLIENT *cli;
258         struct timeval timeout = {0, 0};        /* No timeout, no response. */
259         char dummy;
260
261         if (d_calls)
262                 syslog(LOG_DEBUG, "test request: %s: %s to %s",
263                     msg->lm_nfsv3 ? "V4" : "V1/3",
264                     msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
265                     from_addr((struct sockaddr *)&msg->lm_addr));
266
267         if (msg->lm_nfsv3) {
268                 struct nlm4_testargs arg4;
269
270                 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
271                 arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
272                 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
273                 arg4.alock.caller_name = hostname;
274                 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
275                 arg4.alock.fh.n_len = msg->lm_fh_len;
276                 arg4.alock.oh.n_bytes = (char *)&owner;
277                 arg4.alock.oh.n_len = sizeof(owner);
278                 arg4.alock.svid = msg->lm_msg_ident.pid;
279                 arg4.alock.l_offset = msg->lm_fl.l_start;
280                 arg4.alock.l_len = msg->lm_fl.l_len;
281
282                 if ((cli = get_client(
283                     (struct sockaddr *)&msg->lm_addr,
284                     NLM_VERS4)) == NULL)
285                         return (1);
286
287                 set_auth(cli, &msg->lm_cred);
288                 (void)clnt_call(cli, NLM_TEST_MSG,
289                     (xdrproc_t)xdr_nlm4_testargs, &arg4,
290                     (xdrproc_t)xdr_void, &dummy, timeout);
291         } else {
292                 struct nlm_testargs arg;
293
294                 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
295                 arg.cookie.n_len = sizeof(msg->lm_msg_ident);
296                 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
297                 arg.alock.caller_name = hostname;
298                 arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
299                 arg.alock.fh.n_len = msg->lm_fh_len;
300                 arg.alock.oh.n_bytes = (char *)&owner;
301                 arg.alock.oh.n_len = sizeof(owner);
302                 arg.alock.svid = msg->lm_msg_ident.pid;
303                 arg.alock.l_offset = msg->lm_fl.l_start;
304                 arg.alock.l_len = msg->lm_fl.l_len;
305
306                 if ((cli = get_client(
307                     (struct sockaddr *)&msg->lm_addr,
308                     NLM_VERS)) == NULL)
309                         return (1);
310
311                 set_auth(cli, &msg->lm_cred);
312                 (void)clnt_call(cli, NLM_TEST_MSG,
313                     (xdrproc_t)xdr_nlm_testargs, &arg,
314                     (xdrproc_t)xdr_void, &dummy, timeout);
315         }
316         return (0);
317 }
318
319 /*
320  * lock_request --
321  *      Convert a lock LOCKD_MSG into an NLM request, and send it off.
322  */
323 int
324 lock_request(LOCKD_MSG *msg)
325 {
326         CLIENT *cli;
327         struct nlm4_lockargs arg4;
328         struct nlm_lockargs arg;
329         struct timeval timeout = {0, 0};        /* No timeout, no response. */
330         char dummy;
331
332         if (d_calls)
333                 syslog(LOG_DEBUG, "lock request: %s: %s to %s",
334                     msg->lm_nfsv3 ? "V4" : "V1/3",
335                     msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
336                     from_addr((struct sockaddr *)&msg->lm_addr));
337
338         if (msg->lm_nfsv3) {
339                 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
340                 arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
341                 arg4.block = msg->lm_wait ? 1 : 0;
342                 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
343                 arg4.alock.caller_name = hostname;
344                 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
345                 arg4.alock.fh.n_len = msg->lm_fh_len;
346                 arg4.alock.oh.n_bytes = (char *)&owner;
347                 arg4.alock.oh.n_len = sizeof(owner);
348                 arg4.alock.svid = msg->lm_msg_ident.pid;
349                 arg4.alock.l_offset = msg->lm_fl.l_start;
350                 arg4.alock.l_len = msg->lm_fl.l_len;
351                 arg4.reclaim = 0;
352                 arg4.state = nsm_state;
353
354                 if ((cli = get_client(
355                     (struct sockaddr *)&msg->lm_addr,
356                     NLM_VERS4)) == NULL)
357                         return (1);
358
359                 set_auth(cli, &msg->lm_cred);
360                 (void)clnt_call(cli, NLM_LOCK_MSG,
361                     (xdrproc_t)xdr_nlm4_lockargs, &arg4,
362                     (xdrproc_t)xdr_void, &dummy, timeout);
363         } else {
364                 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
365                 arg.cookie.n_len = sizeof(msg->lm_msg_ident);
366                 arg.block = msg->lm_wait ? 1 : 0;
367                 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
368                 arg.alock.caller_name = hostname;
369                 arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
370                 arg.alock.fh.n_len = msg->lm_fh_len;
371                 arg.alock.oh.n_bytes = (char *)&owner;
372                 arg.alock.oh.n_len = sizeof(owner);
373                 arg.alock.svid = msg->lm_msg_ident.pid;
374                 arg.alock.l_offset = msg->lm_fl.l_start;
375                 arg.alock.l_len = msg->lm_fl.l_len;
376                 arg.reclaim = 0;
377                 arg.state = nsm_state;
378
379                 if ((cli = get_client(
380                     (struct sockaddr *)&msg->lm_addr,
381                     NLM_VERS)) == NULL)
382                         return (1);
383
384                 set_auth(cli, &msg->lm_cred);
385                 (void)clnt_call(cli, NLM_LOCK_MSG,
386                     (xdrproc_t)xdr_nlm_lockargs, &arg,
387                     (xdrproc_t)xdr_void, &dummy, timeout);
388         }
389         return (0);
390 }
391
392 /*
393  * unlock_request --
394  *      Convert an unlock LOCKD_MSG into an NLM request, and send it off.
395  */
396 int
397 unlock_request(LOCKD_MSG *msg)
398 {
399         CLIENT *cli;
400         struct nlm4_unlockargs arg4;
401         struct nlm_unlockargs arg;
402         struct timeval timeout = {0, 0};        /* No timeout, no response. */
403         char dummy;
404
405         if (d_calls)
406                 syslog(LOG_DEBUG, "unlock request: %s: to %s",
407                     msg->lm_nfsv3 ? "V4" : "V1/3",
408                     from_addr((struct sockaddr *)&msg->lm_addr));
409
410         if (msg->lm_nfsv3) {
411                 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
412                 arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
413                 arg4.alock.caller_name = hostname;
414                 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
415                 arg4.alock.fh.n_len = msg->lm_fh_len;
416                 arg4.alock.oh.n_bytes = (char *)&owner;
417                 arg4.alock.oh.n_len = sizeof(owner);
418                 arg4.alock.svid = msg->lm_msg_ident.pid;
419                 arg4.alock.l_offset = msg->lm_fl.l_start;
420                 arg4.alock.l_len = msg->lm_fl.l_len;
421
422                 if ((cli = get_client(
423                     (struct sockaddr *)&msg->lm_addr,
424                     NLM_VERS4)) == NULL)
425                         return (1);
426
427                 set_auth(cli, &msg->lm_cred);
428                 (void)clnt_call(cli, NLM_UNLOCK_MSG,
429                     (xdrproc_t)xdr_nlm4_unlockargs, &arg4,
430                     (xdrproc_t)xdr_void, &dummy, timeout);
431         } else {
432                 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
433                 arg.cookie.n_len = sizeof(msg->lm_msg_ident);
434                 arg.alock.caller_name = hostname;
435                 arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
436                 arg.alock.fh.n_len = msg->lm_fh_len;
437                 arg.alock.oh.n_bytes = (char *)&owner;
438                 arg.alock.oh.n_len = sizeof(owner);
439                 arg.alock.svid = msg->lm_msg_ident.pid;
440                 arg.alock.l_offset = msg->lm_fl.l_start;
441                 arg.alock.l_len = msg->lm_fl.l_len;
442
443                 if ((cli = get_client(
444                     (struct sockaddr *)&msg->lm_addr,
445                     NLM_VERS)) == NULL)
446                         return (1);
447
448                 set_auth(cli, &msg->lm_cred);
449                 (void)clnt_call(cli, NLM_UNLOCK_MSG,
450                     (xdrproc_t)xdr_nlm_unlockargs, &arg,
451                     (xdrproc_t)xdr_void, &dummy, timeout);
452         }
453
454         return (0);
455 }
456
457 int
458 lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version)
459 {
460         struct lockd_ans ans;
461
462         if (netcookie->n_len != sizeof(ans.la_msg_ident)) {
463                 if (pid == -1) {        /* we're screwed */
464                         syslog(LOG_ERR, "inedible nlm cookie");
465                         return -1;
466                 }
467                 ans.la_msg_ident.pid = pid;
468                 ans.la_msg_ident.msg_seq = -1;
469         } else {
470                 memcpy(&ans.la_msg_ident, netcookie->n_bytes,
471                     sizeof(ans.la_msg_ident));
472         }
473
474         if (d_calls)
475                 syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d",
476                     (unsigned long)ans.la_msg_ident.pid,
477                     version == NLM_VERS4 ? "nlmv4" : "nlmv3",
478                     result);
479
480         ans.la_set_getlk_pid = 0;
481         if (version == NLM_VERS4)
482                 switch (result) {
483                 case nlm4_granted:
484                         ans.la_errno = 0;
485                         break;
486                 default:
487                         ans.la_errno = EACCES;
488                         break;
489                 case nlm4_denied:
490                         if (pid_p == NULL)
491                                 ans.la_errno = EAGAIN;
492                         else {
493                                 /* this is an answer to a nlm_test msg */
494                                 ans.la_set_getlk_pid = 1;
495                                 ans.la_getlk_pid = *pid_p;
496                                 ans.la_errno = 0;
497                         }
498                         break;
499                 case nlm4_denied_nolocks:
500                         ans.la_errno = EAGAIN;
501                         break;
502                 case nlm4_blocked:
503                         return -1;
504                         /* NOTREACHED */
505                 case nlm4_denied_grace_period:
506                         ans.la_errno = EAGAIN;
507                         break;
508                 case nlm4_deadlck:
509                         ans.la_errno = EDEADLK;
510                         break;
511                 case nlm4_rofs:
512                         ans.la_errno = EROFS;
513                         break;
514                 case nlm4_stale_fh:
515                         ans.la_errno = ESTALE;
516                         break;
517                 case nlm4_fbig:
518                         ans.la_errno = EFBIG;
519                         break;
520                 case nlm4_failed:
521                         ans.la_errno = EACCES;
522                         break;
523                 }
524         else
525                 switch (result) {
526                 case nlm_granted:
527                         ans.la_errno = 0;
528                         break;
529                 default:
530                         ans.la_errno = EACCES;
531                         break;
532                 case nlm_denied:
533                         if (pid_p == NULL)
534                                 ans.la_errno = EAGAIN;
535                         else {
536                                 /* this is an answer to a nlm_test msg */
537                                 ans.la_set_getlk_pid = 1;
538                                 ans.la_getlk_pid = *pid_p;
539                                 ans.la_errno = 0;
540                         }
541                         break;
542                 case nlm_denied_nolocks:
543                         ans.la_errno = EAGAIN;
544                         break;
545                 case nlm_blocked:
546                         return -1;
547                         /* NOTREACHED */
548                 case nlm_denied_grace_period:
549                         ans.la_errno = EAGAIN;
550                         break;
551                 case nlm_deadlck:
552                         ans.la_errno = EDEADLK;
553                         break;
554                 }
555
556         if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
557                 syslog(((errno == EPIPE || errno == ESRCH) ? 
558                         LOG_INFO : LOG_ERR), 
559                         "process %lu: %m", (u_long)ans.la_msg_ident.pid);
560                 return -1;
561         }
562         return 0;
563 }
564
565 /*
566  * show --
567  *      Display the contents of a kernel LOCKD_MSG structure.
568  */
569 void
570 show(LOCKD_MSG *mp)
571 {
572         static char hex[] = "0123456789abcdef";
573         struct fid *fidp;
574         fsid_t *fsidp;
575         size_t len;
576         u_int8_t *p, *t, buf[NFS_SMALLFH*3+1];
577
578         syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid);
579
580         fsidp = (fsid_t *)&mp->lm_fh;
581         fidp = (struct fid *)((u_int8_t *)&mp->lm_fh + sizeof(fsid_t));
582
583         for (t = buf, p = (u_int8_t *)mp->lm_fh,
584             len = mp->lm_fh_len;
585             len > 0; ++p, --len) {
586                 *t++ = '\\';
587                 *t++ = hex[(*p & 0xf0) >> 4];
588                 *t++ = hex[*p & 0x0f];
589         }
590         *t = '\0';
591
592         syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf);
593
594         /* Show flock structure. */
595         syslog(LOG_DEBUG, "start %llu; len %llu; pid %lu; type %d; whence %d\n",
596             (unsigned long long)mp->lm_fl.l_start,
597             (unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid,
598             mp->lm_fl.l_type, mp->lm_fl.l_whence);
599
600         /* Show wait flag. */
601         syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set");
602 }