lockd: Adjust nlmclnt_lookup_host() signature to accomodate non-AF_INET
[linux-2.6] / fs / lockd / host.c
1 /*
2  * linux/fs/lockd/host.c
3  *
4  * Management for NLM peer hosts. The nlm_host struct is shared
5  * between client and server implementation. The only reason to
6  * do so is to reduce code bloat.
7  *
8  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
9  */
10
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/in.h>
14 #include <linux/in6.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/svc.h>
17 #include <linux/lockd/lockd.h>
18 #include <linux/lockd/sm_inter.h>
19 #include <linux/mutex.h>
20
21 #include <net/ipv6.h>
22
23 #define NLMDBG_FACILITY         NLMDBG_HOSTCACHE
24 #define NLM_HOST_NRHASH         32
25 #define NLM_HOST_REBIND         (60 * HZ)
26 #define NLM_HOST_EXPIRE         (300 * HZ)
27 #define NLM_HOST_COLLECT        (120 * HZ)
28
29 static struct hlist_head        nlm_hosts[NLM_HOST_NRHASH];
30 static unsigned long            next_gc;
31 static int                      nrhosts;
32 static DEFINE_MUTEX(nlm_host_mutex);
33
34 static void                     nlm_gc_hosts(void);
35 static struct nsm_handle        *nsm_find(const struct sockaddr *sap,
36                                                 const size_t salen,
37                                                 const char *hostname,
38                                                 const size_t hostname_len,
39                                                 const int create);
40
41 struct nlm_lookup_host_info {
42         const int               server;         /* search for server|client */
43         const struct sockaddr   *sap;           /* address to search for */
44         const size_t            salen;          /* it's length */
45         const unsigned short    protocol;       /* transport to search for*/
46         const u32               version;        /* NLM version to search for */
47         const char              *hostname;      /* remote's hostname */
48         const size_t            hostname_len;   /* it's length */
49         const struct sockaddr   *src_sap;       /* our address (optional) */
50         const size_t            src_len;        /* it's length */
51 };
52
53 /*
54  * Hash function must work well on big- and little-endian platforms
55  */
56 static unsigned int __nlm_hash32(const __be32 n)
57 {
58         unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
59         return hash ^ (hash >> 8);
60 }
61
62 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
63 {
64         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
65         return __nlm_hash32(sin->sin_addr.s_addr);
66 }
67
68 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
69 {
70         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
71         const struct in6_addr addr = sin6->sin6_addr;
72         return __nlm_hash32(addr.s6_addr32[0]) ^
73                __nlm_hash32(addr.s6_addr32[1]) ^
74                __nlm_hash32(addr.s6_addr32[2]) ^
75                __nlm_hash32(addr.s6_addr32[3]);
76 }
77
78 static unsigned int nlm_hash_address(const struct sockaddr *sap)
79 {
80         unsigned int hash;
81
82         switch (sap->sa_family) {
83         case AF_INET:
84                 hash = __nlm_hash_addr4(sap);
85                 break;
86         case AF_INET6:
87                 hash = __nlm_hash_addr6(sap);
88                 break;
89         default:
90                 hash = 0;
91         }
92         return hash & (NLM_HOST_NRHASH - 1);
93 }
94
95 static void nlm_clear_port(struct sockaddr *sap)
96 {
97         switch (sap->sa_family) {
98         case AF_INET:
99                 ((struct sockaddr_in *)sap)->sin_port = 0;
100                 break;
101         case AF_INET6:
102                 ((struct sockaddr_in6 *)sap)->sin6_port = 0;
103                 break;
104         }
105 }
106
107 static void nlm_display_address(const struct sockaddr *sap,
108                                 char *buf, const size_t len)
109 {
110         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
111         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
112
113         switch (sap->sa_family) {
114         case AF_UNSPEC:
115                 snprintf(buf, len, "unspecified");
116                 break;
117         case AF_INET:
118                 snprintf(buf, len, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
119                 break;
120         case AF_INET6:
121                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
122                         snprintf(buf, len, NIPQUAD_FMT,
123                                  NIPQUAD(sin6->sin6_addr.s6_addr32[3]));
124                 else
125                         snprintf(buf, len, NIP6_FMT, NIP6(sin6->sin6_addr));
126                 break;
127         default:
128                 snprintf(buf, len, "unsupported address family");
129                 break;
130         }
131 }
132
133 /*
134  * Common host lookup routine for server & client
135  */
136 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
137 {
138         struct hlist_head *chain;
139         struct hlist_node *pos;
140         struct nlm_host *host;
141         struct nsm_handle *nsm = NULL;
142
143         mutex_lock(&nlm_host_mutex);
144
145         if (time_after_eq(jiffies, next_gc))
146                 nlm_gc_hosts();
147
148         /* We may keep several nlm_host objects for a peer, because each
149          * nlm_host is identified by
150          * (address, protocol, version, server/client)
151          * We could probably simplify this a little by putting all those
152          * different NLM rpc_clients into one single nlm_host object.
153          * This would allow us to have one nlm_host per address.
154          */
155         chain = &nlm_hosts[nlm_hash_address(ni->sap)];
156         hlist_for_each_entry(host, pos, chain, h_hash) {
157                 if (!nlm_cmp_addr(nlm_addr(host), ni->sap))
158                         continue;
159
160                 /* See if we have an NSM handle for this client */
161                 if (!nsm)
162                         nsm = host->h_nsmhandle;
163
164                 if (host->h_proto != ni->protocol)
165                         continue;
166                 if (host->h_version != ni->version)
167                         continue;
168                 if (host->h_server != ni->server)
169                         continue;
170                 if (!nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap))
171                         continue;
172
173                 /* Move to head of hash chain. */
174                 hlist_del(&host->h_hash);
175                 hlist_add_head(&host->h_hash, chain);
176
177                 nlm_get_host(host);
178                 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
179                                 host->h_name, host->h_addrbuf);
180                 goto out;
181         }
182
183         /*
184          * The host wasn't in our hash table.  If we don't
185          * have an NSM handle for it yet, create one.
186          */
187         if (nsm)
188                 atomic_inc(&nsm->sm_count);
189         else {
190                 host = NULL;
191                 nsm = nsm_find(ni->sap, ni->salen,
192                                 ni->hostname, ni->hostname_len, 1);
193                 if (!nsm) {
194                         dprintk("lockd: nlm_lookup_host failed; "
195                                 "no nsm handle\n");
196                         goto out;
197                 }
198         }
199
200         host = kzalloc(sizeof(*host), GFP_KERNEL);
201         if (!host) {
202                 nsm_release(nsm);
203                 dprintk("lockd: nlm_lookup_host failed; no memory\n");
204                 goto out;
205         }
206         host->h_name       = nsm->sm_name;
207         memcpy(nlm_addr(host), ni->sap, ni->salen);
208         host->h_addrlen = ni->salen;
209         nlm_clear_port(nlm_addr(host));
210         memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
211         host->h_version    = ni->version;
212         host->h_proto      = ni->protocol;
213         host->h_rpcclnt    = NULL;
214         mutex_init(&host->h_mutex);
215         host->h_nextrebind = jiffies + NLM_HOST_REBIND;
216         host->h_expires    = jiffies + NLM_HOST_EXPIRE;
217         atomic_set(&host->h_count, 1);
218         init_waitqueue_head(&host->h_gracewait);
219         init_rwsem(&host->h_rwsem);
220         host->h_state      = 0;                 /* pseudo NSM state */
221         host->h_nsmstate   = 0;                 /* real NSM state */
222         host->h_nsmhandle  = nsm;
223         host->h_server     = ni->server;
224         hlist_add_head(&host->h_hash, chain);
225         INIT_LIST_HEAD(&host->h_lockowners);
226         spin_lock_init(&host->h_lock);
227         INIT_LIST_HEAD(&host->h_granted);
228         INIT_LIST_HEAD(&host->h_reclaim);
229
230         nrhosts++;
231
232         nlm_display_address((struct sockaddr *)&host->h_addr,
233                                 host->h_addrbuf, sizeof(host->h_addrbuf));
234         nlm_display_address((struct sockaddr *)&host->h_srcaddr,
235                                 host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
236
237         dprintk("lockd: nlm_lookup_host created host %s\n",
238                         host->h_name);
239
240 out:
241         mutex_unlock(&nlm_host_mutex);
242         return host;
243 }
244
245 /*
246  * Destroy a host
247  */
248 static void
249 nlm_destroy_host(struct nlm_host *host)
250 {
251         struct rpc_clnt *clnt;
252
253         BUG_ON(!list_empty(&host->h_lockowners));
254         BUG_ON(atomic_read(&host->h_count));
255
256         /*
257          * Release NSM handle and unmonitor host.
258          */
259         nsm_unmonitor(host);
260
261         clnt = host->h_rpcclnt;
262         if (clnt != NULL)
263                 rpc_shutdown_client(clnt);
264         kfree(host);
265 }
266
267 /**
268  * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
269  * @sap: network address of server
270  * @salen: length of server address
271  * @protocol: transport protocol to use
272  * @version: NLM protocol version
273  * @hostname: '\0'-terminated hostname of server
274  *
275  * Returns an nlm_host structure that matches the passed-in
276  * [server address, transport protocol, NLM version, server hostname].
277  * If one doesn't already exist in the host cache, a new handle is
278  * created and returned.
279  */
280 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
281                                      const size_t salen,
282                                      const unsigned short protocol,
283                                      const u32 version, const char *hostname)
284 {
285         const struct sockaddr source = {
286                 .sa_family      = AF_UNSPEC,
287         };
288         struct nlm_lookup_host_info ni = {
289                 .server         = 0,
290                 .sap            = sap,
291                 .salen          = salen,
292                 .protocol       = protocol,
293                 .version        = version,
294                 .hostname       = hostname,
295                 .hostname_len   = strlen(hostname),
296                 .src_sap        = &source,
297                 .src_len        = sizeof(source),
298         };
299
300         dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
301                         (hostname ? hostname : "<none>"), version,
302                         (protocol == IPPROTO_UDP ? "udp" : "tcp"));
303
304         return nlm_lookup_host(&ni);
305 }
306
307 /*
308  * Find an NLM client handle in the cache. If there is none, create it.
309  */
310 struct nlm_host *
311 nlmsvc_lookup_host(struct svc_rqst *rqstp,
312                         const char *hostname, unsigned int hostname_len)
313 {
314         const struct sockaddr_in source = {
315                 .sin_family     = AF_INET,
316                 .sin_addr       = rqstp->rq_daddr.addr,
317         };
318         struct nlm_lookup_host_info ni = {
319                 .server         = 1,
320                 .sap            = svc_addr(rqstp),
321                 .salen          = rqstp->rq_addrlen,
322                 .protocol       = rqstp->rq_prot,
323                 .version        = rqstp->rq_vers,
324                 .hostname       = hostname,
325                 .hostname_len   = hostname_len,
326                 .src_sap        = (struct sockaddr *)&source,
327                 .src_len        = sizeof(source),
328         };
329
330         dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
331                         (int)hostname_len, hostname, rqstp->rq_vers,
332                         (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
333
334         return nlm_lookup_host(&ni);
335 }
336
337 /*
338  * Create the NLM RPC client for an NLM peer
339  */
340 struct rpc_clnt *
341 nlm_bind_host(struct nlm_host *host)
342 {
343         struct rpc_clnt *clnt;
344
345         dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
346                         host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
347
348         /* Lock host handle */
349         mutex_lock(&host->h_mutex);
350
351         /* If we've already created an RPC client, check whether
352          * RPC rebind is required
353          */
354         if ((clnt = host->h_rpcclnt) != NULL) {
355                 if (time_after_eq(jiffies, host->h_nextrebind)) {
356                         rpc_force_rebind(clnt);
357                         host->h_nextrebind = jiffies + NLM_HOST_REBIND;
358                         dprintk("lockd: next rebind in %lu jiffies\n",
359                                         host->h_nextrebind - jiffies);
360                 }
361         } else {
362                 unsigned long increment = nlmsvc_timeout;
363                 struct rpc_timeout timeparms = {
364                         .to_initval     = increment,
365                         .to_increment   = increment,
366                         .to_maxval      = increment * 6UL,
367                         .to_retries     = 5U,
368                 };
369                 struct rpc_create_args args = {
370                         .protocol       = host->h_proto,
371                         .address        = nlm_addr(host),
372                         .addrsize       = host->h_addrlen,
373                         .saddress       = nlm_srcaddr(host),
374                         .timeout        = &timeparms,
375                         .servername     = host->h_name,
376                         .program        = &nlm_program,
377                         .version        = host->h_version,
378                         .authflavor     = RPC_AUTH_UNIX,
379                         .flags          = (RPC_CLNT_CREATE_NOPING |
380                                            RPC_CLNT_CREATE_AUTOBIND),
381                 };
382
383                 /*
384                  * lockd retries server side blocks automatically so we want
385                  * those to be soft RPC calls. Client side calls need to be
386                  * hard RPC tasks.
387                  */
388                 if (!host->h_server)
389                         args.flags |= RPC_CLNT_CREATE_HARDRTRY;
390
391                 clnt = rpc_create(&args);
392                 if (!IS_ERR(clnt))
393                         host->h_rpcclnt = clnt;
394                 else {
395                         printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
396                         clnt = NULL;
397                 }
398         }
399
400         mutex_unlock(&host->h_mutex);
401         return clnt;
402 }
403
404 /*
405  * Force a portmap lookup of the remote lockd port
406  */
407 void
408 nlm_rebind_host(struct nlm_host *host)
409 {
410         dprintk("lockd: rebind host %s\n", host->h_name);
411         if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
412                 rpc_force_rebind(host->h_rpcclnt);
413                 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
414         }
415 }
416
417 /*
418  * Increment NLM host count
419  */
420 struct nlm_host * nlm_get_host(struct nlm_host *host)
421 {
422         if (host) {
423                 dprintk("lockd: get host %s\n", host->h_name);
424                 atomic_inc(&host->h_count);
425                 host->h_expires = jiffies + NLM_HOST_EXPIRE;
426         }
427         return host;
428 }
429
430 /*
431  * Release NLM host after use
432  */
433 void nlm_release_host(struct nlm_host *host)
434 {
435         if (host != NULL) {
436                 dprintk("lockd: release host %s\n", host->h_name);
437                 BUG_ON(atomic_read(&host->h_count) < 0);
438                 if (atomic_dec_and_test(&host->h_count)) {
439                         BUG_ON(!list_empty(&host->h_lockowners));
440                         BUG_ON(!list_empty(&host->h_granted));
441                         BUG_ON(!list_empty(&host->h_reclaim));
442                 }
443         }
444 }
445
446 /*
447  * We were notified that the host indicated by address &sin
448  * has rebooted.
449  * Release all resources held by that peer.
450  */
451 void nlm_host_rebooted(const struct sockaddr_in *sin,
452                                 const char *hostname,
453                                 unsigned int hostname_len,
454                                 u32 new_state)
455 {
456         struct hlist_head *chain;
457         struct hlist_node *pos;
458         struct nsm_handle *nsm;
459         struct nlm_host *host;
460
461         nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
462                         hostname, hostname_len, 0);
463         if (nsm == NULL) {
464                 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
465                                 hostname_len, hostname);
466                 return;
467         }
468
469         dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
470                         hostname_len, hostname, nsm->sm_addrbuf);
471
472         /* When reclaiming locks on this peer, make sure that
473          * we set up a new notification */
474         nsm->sm_monitored = 0;
475
476         /* Mark all hosts tied to this NSM state as having rebooted.
477          * We run the loop repeatedly, because we drop the host table
478          * lock for this.
479          * To avoid processing a host several times, we match the nsmstate.
480          */
481 again:  mutex_lock(&nlm_host_mutex);
482         for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
483                 hlist_for_each_entry(host, pos, chain, h_hash) {
484                         if (host->h_nsmhandle == nsm
485                          && host->h_nsmstate != new_state) {
486                                 host->h_nsmstate = new_state;
487                                 host->h_state++;
488
489                                 nlm_get_host(host);
490                                 mutex_unlock(&nlm_host_mutex);
491
492                                 if (host->h_server) {
493                                         /* We're server for this guy, just ditch
494                                          * all the locks he held. */
495                                         nlmsvc_free_host_resources(host);
496                                 } else {
497                                         /* He's the server, initiate lock recovery. */
498                                         nlmclnt_recovery(host);
499                                 }
500
501                                 nlm_release_host(host);
502                                 goto again;
503                         }
504                 }
505         }
506
507         mutex_unlock(&nlm_host_mutex);
508 }
509
510 /*
511  * Shut down the hosts module.
512  * Note that this routine is called only at server shutdown time.
513  */
514 void
515 nlm_shutdown_hosts(void)
516 {
517         struct hlist_head *chain;
518         struct hlist_node *pos;
519         struct nlm_host *host;
520
521         dprintk("lockd: shutting down host module\n");
522         mutex_lock(&nlm_host_mutex);
523
524         /* First, make all hosts eligible for gc */
525         dprintk("lockd: nuking all hosts...\n");
526         for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
527                 hlist_for_each_entry(host, pos, chain, h_hash) {
528                         host->h_expires = jiffies - 1;
529                         if (host->h_rpcclnt) {
530                                 rpc_shutdown_client(host->h_rpcclnt);
531                                 host->h_rpcclnt = NULL;
532                         }
533                 }
534         }
535
536         /* Then, perform a garbage collection pass */
537         nlm_gc_hosts();
538         mutex_unlock(&nlm_host_mutex);
539
540         /* complain if any hosts are left */
541         if (nrhosts) {
542                 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
543                 dprintk("lockd: %d hosts left:\n", nrhosts);
544                 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
545                         hlist_for_each_entry(host, pos, chain, h_hash) {
546                                 dprintk("       %s (cnt %d use %d exp %ld)\n",
547                                         host->h_name, atomic_read(&host->h_count),
548                                         host->h_inuse, host->h_expires);
549                         }
550                 }
551         }
552 }
553
554 /*
555  * Garbage collect any unused NLM hosts.
556  * This GC combines reference counting for async operations with
557  * mark & sweep for resources held by remote clients.
558  */
559 static void
560 nlm_gc_hosts(void)
561 {
562         struct hlist_head *chain;
563         struct hlist_node *pos, *next;
564         struct nlm_host *host;
565
566         dprintk("lockd: host garbage collection\n");
567         for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
568                 hlist_for_each_entry(host, pos, chain, h_hash)
569                         host->h_inuse = 0;
570         }
571
572         /* Mark all hosts that hold locks, blocks or shares */
573         nlmsvc_mark_resources();
574
575         for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
576                 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
577                         if (atomic_read(&host->h_count) || host->h_inuse
578                          || time_before(jiffies, host->h_expires)) {
579                                 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
580                                         host->h_name, atomic_read(&host->h_count),
581                                         host->h_inuse, host->h_expires);
582                                 continue;
583                         }
584                         dprintk("lockd: delete host %s\n", host->h_name);
585                         hlist_del_init(&host->h_hash);
586
587                         nlm_destroy_host(host);
588                         nrhosts--;
589                 }
590         }
591
592         next_gc = jiffies + NLM_HOST_COLLECT;
593 }
594
595
596 /*
597  * Manage NSM handles
598  */
599 static LIST_HEAD(nsm_handles);
600 static DEFINE_SPINLOCK(nsm_lock);
601
602 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
603                                    const size_t salen,
604                                    const char *hostname,
605                                    const size_t hostname_len,
606                                    const int create)
607 {
608         struct nsm_handle *nsm = NULL;
609         struct nsm_handle *pos;
610
611         if (!sap)
612                 return NULL;
613
614         if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
615                 if (printk_ratelimit()) {
616                         printk(KERN_WARNING "Invalid hostname \"%.*s\" "
617                                             "in NFS lock request\n",
618                                 (int)hostname_len, hostname);
619                 }
620                 return NULL;
621         }
622
623 retry:
624         spin_lock(&nsm_lock);
625         list_for_each_entry(pos, &nsm_handles, sm_link) {
626
627                 if (hostname && nsm_use_hostnames) {
628                         if (strlen(pos->sm_name) != hostname_len
629                          || memcmp(pos->sm_name, hostname, hostname_len))
630                                 continue;
631                 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
632                         continue;
633                 atomic_inc(&pos->sm_count);
634                 kfree(nsm);
635                 nsm = pos;
636                 goto found;
637         }
638         if (nsm) {
639                 list_add(&nsm->sm_link, &nsm_handles);
640                 goto found;
641         }
642         spin_unlock(&nsm_lock);
643
644         if (!create)
645                 return NULL;
646
647         nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
648         if (nsm == NULL)
649                 return NULL;
650
651         memcpy(nsm_addr(nsm), sap, salen);
652         nsm->sm_addrlen = salen;
653         nsm->sm_name = (char *) (nsm + 1);
654         memcpy(nsm->sm_name, hostname, hostname_len);
655         nsm->sm_name[hostname_len] = '\0';
656         nlm_display_address((struct sockaddr *)&nsm->sm_addr,
657                                 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
658         atomic_set(&nsm->sm_count, 1);
659         goto retry;
660
661 found:
662         spin_unlock(&nsm_lock);
663         return nsm;
664 }
665
666 /*
667  * Release an NSM handle
668  */
669 void
670 nsm_release(struct nsm_handle *nsm)
671 {
672         if (!nsm)
673                 return;
674         if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
675                 list_del(&nsm->sm_link);
676                 spin_unlock(&nsm_lock);
677                 kfree(nsm);
678         }
679 }