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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/mutex.h>
19
20#include <net/ipv6.h>
21
22#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
23#define NLM_HOST_NRHASH 32
24#define NLM_HOST_REBIND (60 * HZ)
25#define NLM_HOST_EXPIRE (300 * HZ)
26#define NLM_HOST_COLLECT (120 * HZ)
27
28static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
29static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
30
31#define for_each_host(host, pos, chain, table) \
32 for ((chain) = (table); \
33 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
34 hlist_for_each_entry((host), (pos), (chain), h_hash)
35
36#define for_each_host_safe(host, pos, next, chain, table) \
37 for ((chain) = (table); \
38 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
39 hlist_for_each_entry_safe((host), (pos), (next), \
40 (chain), h_hash)
41
42static unsigned long next_gc;
43static unsigned long nrhosts;
44static DEFINE_MUTEX(nlm_host_mutex);
45
46static void nlm_gc_hosts(void);
47
48struct nlm_lookup_host_info {
49 const int server; /* search for server|client */
50 const struct sockaddr *sap; /* address to search for */
51 const size_t salen; /* it's length */
52 const unsigned short protocol; /* transport to search for*/
53 const u32 version; /* NLM version to search for */
54 const char *hostname; /* remote's hostname */
55 const size_t hostname_len; /* it's length */
56 const int noresvport; /* use non-priv port */
57};
58
59/*
60 * Hash function must work well on big- and little-endian platforms
61 */
62static unsigned int __nlm_hash32(const __be32 n)
63{
64 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
65 return hash ^ (hash >> 8);
66}
67
68static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
69{
70 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
71 return __nlm_hash32(sin->sin_addr.s_addr);
72}
73
74static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
75{
76 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
77 const struct in6_addr addr = sin6->sin6_addr;
78 return __nlm_hash32(addr.s6_addr32[0]) ^
79 __nlm_hash32(addr.s6_addr32[1]) ^
80 __nlm_hash32(addr.s6_addr32[2]) ^
81 __nlm_hash32(addr.s6_addr32[3]);
82}
83
84static unsigned int nlm_hash_address(const struct sockaddr *sap)
85{
86 unsigned int hash;
87
88 switch (sap->sa_family) {
89 case AF_INET:
90 hash = __nlm_hash_addr4(sap);
91 break;
92 case AF_INET6:
93 hash = __nlm_hash_addr6(sap);
94 break;
95 default:
96 hash = 0;
97 }
98 return hash & (NLM_HOST_NRHASH - 1);
99}
100
101/*
102 * Allocate and initialize an nlm_host. Common to both client and server.
103 */
104static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
105 struct nsm_handle *nsm)
106{
107 struct nlm_host *host = NULL;
108 unsigned long now = jiffies;
109
110 if (nsm != NULL)
111 atomic_inc(&nsm->sm_count);
112 else {
113 host = NULL;
114 nsm = nsm_get_handle(ni->sap, ni->salen,
115 ni->hostname, ni->hostname_len);
116 if (unlikely(nsm == NULL)) {
117 dprintk("lockd: %s failed; no nsm handle\n",
118 __func__);
119 goto out;
120 }
121 }
122
123 host = kmalloc(sizeof(*host), GFP_KERNEL);
124 if (unlikely(host == NULL)) {
125 dprintk("lockd: %s failed; no memory\n", __func__);
126 nsm_release(nsm);
127 goto out;
128 }
129
130 memcpy(nlm_addr(host), ni->sap, ni->salen);
131 host->h_addrlen = ni->salen;
132 rpc_set_port(nlm_addr(host), 0);
133 host->h_srcaddrlen = 0;
134
135 host->h_rpcclnt = NULL;
136 host->h_name = nsm->sm_name;
137 host->h_version = ni->version;
138 host->h_proto = ni->protocol;
139 host->h_reclaiming = 0;
140 host->h_server = ni->server;
141 host->h_noresvport = ni->noresvport;
142 host->h_inuse = 0;
143 init_waitqueue_head(&host->h_gracewait);
144 init_rwsem(&host->h_rwsem);
145 host->h_state = 0;
146 host->h_nsmstate = 0;
147 host->h_pidcount = 0;
148 atomic_set(&host->h_count, 1);
149 mutex_init(&host->h_mutex);
150 host->h_nextrebind = now + NLM_HOST_REBIND;
151 host->h_expires = now + NLM_HOST_EXPIRE;
152 INIT_LIST_HEAD(&host->h_lockowners);
153 spin_lock_init(&host->h_lock);
154 INIT_LIST_HEAD(&host->h_granted);
155 INIT_LIST_HEAD(&host->h_reclaim);
156 host->h_nsmhandle = nsm;
157 host->h_addrbuf = nsm->sm_addrbuf;
158
159out:
160 return host;
161}
162
163/*
164 * Destroy an nlm_host and free associated resources
165 *
166 * Caller must hold nlm_host_mutex.
167 */
168static void nlm_destroy_host_locked(struct nlm_host *host)
169{
170 struct rpc_clnt *clnt;
171
172 dprintk("lockd: destroy host %s\n", host->h_name);
173
174 BUG_ON(!list_empty(&host->h_lockowners));
175 BUG_ON(atomic_read(&host->h_count));
176
177 hlist_del_init(&host->h_hash);
178
179 nsm_unmonitor(host);
180 nsm_release(host->h_nsmhandle);
181
182 clnt = host->h_rpcclnt;
183 if (clnt != NULL)
184 rpc_shutdown_client(clnt);
185 kfree(host);
186
187 nrhosts--;
188}
189
190/**
191 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
192 * @sap: network address of server
193 * @salen: length of server address
194 * @protocol: transport protocol to use
195 * @version: NLM protocol version
196 * @hostname: '\0'-terminated hostname of server
197 * @noresvport: 1 if non-privileged port should be used
198 *
199 * Returns an nlm_host structure that matches the passed-in
200 * [server address, transport protocol, NLM version, server hostname].
201 * If one doesn't already exist in the host cache, a new handle is
202 * created and returned.
203 */
204struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
205 const size_t salen,
206 const unsigned short protocol,
207 const u32 version,
208 const char *hostname,
209 int noresvport)
210{
211 struct nlm_lookup_host_info ni = {
212 .server = 0,
213 .sap = sap,
214 .salen = salen,
215 .protocol = protocol,
216 .version = version,
217 .hostname = hostname,
218 .hostname_len = strlen(hostname),
219 .noresvport = noresvport,
220 };
221 struct hlist_head *chain;
222 struct hlist_node *pos;
223 struct nlm_host *host;
224 struct nsm_handle *nsm = NULL;
225
226 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
227 (hostname ? hostname : "<none>"), version,
228 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
229
230 mutex_lock(&nlm_host_mutex);
231
232 chain = &nlm_client_hosts[nlm_hash_address(sap)];
233 hlist_for_each_entry(host, pos, chain, h_hash) {
234 if (!rpc_cmp_addr(nlm_addr(host), sap))
235 continue;
236
237 /* Same address. Share an NSM handle if we already have one */
238 if (nsm == NULL)
239 nsm = host->h_nsmhandle;
240
241 if (host->h_proto != protocol)
242 continue;
243 if (host->h_version != version)
244 continue;
245
246 nlm_get_host(host);
247 dprintk("lockd: %s found host %s (%s)\n", __func__,
248 host->h_name, host->h_addrbuf);
249 goto out;
250 }
251
252 host = nlm_alloc_host(&ni, nsm);
253 if (unlikely(host == NULL))
254 goto out;
255
256 hlist_add_head(&host->h_hash, chain);
257 nrhosts++;
258
259 dprintk("lockd: %s created host %s (%s)\n", __func__,
260 host->h_name, host->h_addrbuf);
261
262out:
263 mutex_unlock(&nlm_host_mutex);
264 return host;
265}
266
267/**
268 * nlmclnt_release_host - release client nlm_host
269 * @host: nlm_host to release
270 *
271 */
272void nlmclnt_release_host(struct nlm_host *host)
273{
274 if (host == NULL)
275 return;
276
277 dprintk("lockd: release client host %s\n", host->h_name);
278
279 BUG_ON(atomic_read(&host->h_count) < 0);
280 BUG_ON(host->h_server);
281
282 if (atomic_dec_and_test(&host->h_count)) {
283 BUG_ON(!list_empty(&host->h_lockowners));
284 BUG_ON(!list_empty(&host->h_granted));
285 BUG_ON(!list_empty(&host->h_reclaim));
286
287 mutex_lock(&nlm_host_mutex);
288 nlm_destroy_host_locked(host);
289 mutex_unlock(&nlm_host_mutex);
290 }
291}
292
293/**
294 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
295 * @rqstp: incoming NLM request
296 * @hostname: name of client host
297 * @hostname_len: length of client hostname
298 *
299 * Returns an nlm_host structure that matches the [client address,
300 * transport protocol, NLM version, client hostname] of the passed-in
301 * NLM request. If one doesn't already exist in the host cache, a
302 * new handle is created and returned.
303 *
304 * Before possibly creating a new nlm_host, construct a sockaddr
305 * for a specific source address in case the local system has
306 * multiple network addresses. The family of the address in
307 * rq_daddr is guaranteed to be the same as the family of the
308 * address in rq_addr, so it's safe to use the same family for
309 * the source address.
310 */
311struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
312 const char *hostname,
313 const size_t hostname_len)
314{
315 struct hlist_head *chain;
316 struct hlist_node *pos;
317 struct nlm_host *host = NULL;
318 struct nsm_handle *nsm = NULL;
319 struct sockaddr_in sin = {
320 .sin_family = AF_INET,
321 };
322 struct sockaddr_in6 sin6 = {
323 .sin6_family = AF_INET6,
324 };
325 struct sockaddr *src_sap;
326 size_t src_len = rqstp->rq_addrlen;
327 struct nlm_lookup_host_info ni = {
328 .server = 1,
329 .sap = svc_addr(rqstp),
330 .salen = rqstp->rq_addrlen,
331 .protocol = rqstp->rq_prot,
332 .version = rqstp->rq_vers,
333 .hostname = hostname,
334 .hostname_len = hostname_len,
335 };
336
337 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
338 (int)hostname_len, hostname, rqstp->rq_vers,
339 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
340
341 mutex_lock(&nlm_host_mutex);
342
343 switch (ni.sap->sa_family) {
344 case AF_INET:
345 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
346 src_sap = (struct sockaddr *)&sin;
347 break;
348 case AF_INET6:
349 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
350 src_sap = (struct sockaddr *)&sin6;
351 break;
352 default:
353 dprintk("lockd: %s failed; unrecognized address family\n",
354 __func__);
355 goto out;
356 }
357
358 if (time_after_eq(jiffies, next_gc))
359 nlm_gc_hosts();
360
361 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
362 hlist_for_each_entry(host, pos, chain, h_hash) {
363 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
364 continue;
365
366 /* Same address. Share an NSM handle if we already have one */
367 if (nsm == NULL)
368 nsm = host->h_nsmhandle;
369
370 if (host->h_proto != ni.protocol)
371 continue;
372 if (host->h_version != ni.version)
373 continue;
374 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
375 continue;
376
377 /* Move to head of hash chain. */
378 hlist_del(&host->h_hash);
379 hlist_add_head(&host->h_hash, chain);
380
381 nlm_get_host(host);
382 dprintk("lockd: %s found host %s (%s)\n",
383 __func__, host->h_name, host->h_addrbuf);
384 goto out;
385 }
386
387 host = nlm_alloc_host(&ni, nsm);
388 if (unlikely(host == NULL))
389 goto out;
390
391 memcpy(nlm_srcaddr(host), src_sap, src_len);
392 host->h_srcaddrlen = src_len;
393 hlist_add_head(&host->h_hash, chain);
394 nrhosts++;
395
396 dprintk("lockd: %s created host %s (%s)\n",
397 __func__, host->h_name, host->h_addrbuf);
398
399out:
400 mutex_unlock(&nlm_host_mutex);
401 return host;
402}
403
404/**
405 * nlmsvc_release_host - release server nlm_host
406 * @host: nlm_host to release
407 *
408 * Host is destroyed later in nlm_gc_host().
409 */
410void nlmsvc_release_host(struct nlm_host *host)
411{
412 if (host == NULL)
413 return;
414
415 dprintk("lockd: release server host %s\n", host->h_name);
416
417 BUG_ON(atomic_read(&host->h_count) < 0);
418 BUG_ON(!host->h_server);
419 atomic_dec(&host->h_count);
420}
421
422/*
423 * Create the NLM RPC client for an NLM peer
424 */
425struct rpc_clnt *
426nlm_bind_host(struct nlm_host *host)
427{
428 struct rpc_clnt *clnt;
429
430 dprintk("lockd: nlm_bind_host %s (%s)\n",
431 host->h_name, host->h_addrbuf);
432
433 /* Lock host handle */
434 mutex_lock(&host->h_mutex);
435
436 /* If we've already created an RPC client, check whether
437 * RPC rebind is required
438 */
439 if ((clnt = host->h_rpcclnt) != NULL) {
440 if (time_after_eq(jiffies, host->h_nextrebind)) {
441 rpc_force_rebind(clnt);
442 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
443 dprintk("lockd: next rebind in %lu jiffies\n",
444 host->h_nextrebind - jiffies);
445 }
446 } else {
447 unsigned long increment = nlmsvc_timeout;
448 struct rpc_timeout timeparms = {
449 .to_initval = increment,
450 .to_increment = increment,
451 .to_maxval = increment * 6UL,
452 .to_retries = 5U,
453 };
454 struct rpc_create_args args = {
455 .net = &init_net,
456 .protocol = host->h_proto,
457 .address = nlm_addr(host),
458 .addrsize = host->h_addrlen,
459 .timeout = &timeparms,
460 .servername = host->h_name,
461 .program = &nlm_program,
462 .version = host->h_version,
463 .authflavor = RPC_AUTH_UNIX,
464 .flags = (RPC_CLNT_CREATE_NOPING |
465 RPC_CLNT_CREATE_AUTOBIND),
466 };
467
468 /*
469 * lockd retries server side blocks automatically so we want
470 * those to be soft RPC calls. Client side calls need to be
471 * hard RPC tasks.
472 */
473 if (!host->h_server)
474 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
475 if (host->h_noresvport)
476 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
477 if (host->h_srcaddrlen)
478 args.saddress = nlm_srcaddr(host);
479
480 clnt = rpc_create(&args);
481 if (!IS_ERR(clnt))
482 host->h_rpcclnt = clnt;
483 else {
484 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
485 clnt = NULL;
486 }
487 }
488
489 mutex_unlock(&host->h_mutex);
490 return clnt;
491}
492
493/*
494 * Force a portmap lookup of the remote lockd port
495 */
496void
497nlm_rebind_host(struct nlm_host *host)
498{
499 dprintk("lockd: rebind host %s\n", host->h_name);
500 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
501 rpc_force_rebind(host->h_rpcclnt);
502 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
503 }
504}
505
506/*
507 * Increment NLM host count
508 */
509struct nlm_host * nlm_get_host(struct nlm_host *host)
510{
511 if (host) {
512 dprintk("lockd: get host %s\n", host->h_name);
513 atomic_inc(&host->h_count);
514 host->h_expires = jiffies + NLM_HOST_EXPIRE;
515 }
516 return host;
517}
518
519static struct nlm_host *next_host_state(struct hlist_head *cache,
520 struct nsm_handle *nsm,
521 const struct nlm_reboot *info)
522{
523 struct nlm_host *host;
524 struct hlist_head *chain;
525 struct hlist_node *pos;
526
527 mutex_lock(&nlm_host_mutex);
528 for_each_host(host, pos, chain, cache) {
529 if (host->h_nsmhandle == nsm
530 && host->h_nsmstate != info->state) {
531 host->h_nsmstate = info->state;
532 host->h_state++;
533
534 nlm_get_host(host);
535 mutex_unlock(&nlm_host_mutex);
536 return host;
537 }
538 }
539
540 mutex_unlock(&nlm_host_mutex);
541 return NULL;
542}
543
544/**
545 * nlm_host_rebooted - Release all resources held by rebooted host
546 * @info: pointer to decoded results of NLM_SM_NOTIFY call
547 *
548 * We were notified that the specified host has rebooted. Release
549 * all resources held by that peer.
550 */
551void nlm_host_rebooted(const struct nlm_reboot *info)
552{
553 struct nsm_handle *nsm;
554 struct nlm_host *host;
555
556 nsm = nsm_reboot_lookup(info);
557 if (unlikely(nsm == NULL))
558 return;
559
560 /* Mark all hosts tied to this NSM state as having rebooted.
561 * We run the loop repeatedly, because we drop the host table
562 * lock for this.
563 * To avoid processing a host several times, we match the nsmstate.
564 */
565 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
566 nlmsvc_free_host_resources(host);
567 nlmsvc_release_host(host);
568 }
569 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
570 nlmclnt_recovery(host);
571 nlmclnt_release_host(host);
572 }
573
574 nsm_release(nsm);
575}
576
577/*
578 * Shut down the hosts module.
579 * Note that this routine is called only at server shutdown time.
580 */
581void
582nlm_shutdown_hosts(void)
583{
584 struct hlist_head *chain;
585 struct hlist_node *pos;
586 struct nlm_host *host;
587
588 dprintk("lockd: shutting down host module\n");
589 mutex_lock(&nlm_host_mutex);
590
591 /* First, make all hosts eligible for gc */
592 dprintk("lockd: nuking all hosts...\n");
593 for_each_host(host, pos, chain, nlm_server_hosts) {
594 host->h_expires = jiffies - 1;
595 if (host->h_rpcclnt) {
596 rpc_shutdown_client(host->h_rpcclnt);
597 host->h_rpcclnt = NULL;
598 }
599 }
600
601 /* Then, perform a garbage collection pass */
602 nlm_gc_hosts();
603 mutex_unlock(&nlm_host_mutex);
604
605 /* complain if any hosts are left */
606 if (nrhosts != 0) {
607 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
608 dprintk("lockd: %lu hosts left:\n", nrhosts);
609 for_each_host(host, pos, chain, nlm_server_hosts) {
610 dprintk(" %s (cnt %d use %d exp %ld)\n",
611 host->h_name, atomic_read(&host->h_count),
612 host->h_inuse, host->h_expires);
613 }
614 }
615}
616
617/*
618 * Garbage collect any unused NLM hosts.
619 * This GC combines reference counting for async operations with
620 * mark & sweep for resources held by remote clients.
621 */
622static void
623nlm_gc_hosts(void)
624{
625 struct hlist_head *chain;
626 struct hlist_node *pos, *next;
627 struct nlm_host *host;
628
629 dprintk("lockd: host garbage collection\n");
630 for_each_host(host, pos, chain, nlm_server_hosts)
631 host->h_inuse = 0;
632
633 /* Mark all hosts that hold locks, blocks or shares */
634 nlmsvc_mark_resources();
635
636 for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
637 if (atomic_read(&host->h_count) || host->h_inuse
638 || time_before(jiffies, host->h_expires)) {
639 dprintk("nlm_gc_hosts skipping %s "
640 "(cnt %d use %d exp %ld)\n",
641 host->h_name, atomic_read(&host->h_count),
642 host->h_inuse, host->h_expires);
643 continue;
644 }
645 nlm_destroy_host_locked(host);
646 }
647
648 next_gc = jiffies + NLM_HOST_COLLECT;
649}
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/mutex.h>
19
20#include <linux/sunrpc/svc_xprt.h>
21
22#include <net/ipv6.h>
23
24#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
25#define NLM_HOST_NRHASH 32
26#define NLM_HOST_REBIND (60 * HZ)
27#define NLM_HOST_EXPIRE (300 * HZ)
28#define NLM_HOST_COLLECT (120 * HZ)
29
30static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
31static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
32
33#define for_each_host(host, pos, chain, table) \
34 for ((chain) = (table); \
35 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
36 hlist_for_each_entry((host), (pos), (chain), h_hash)
37
38#define for_each_host_safe(host, pos, next, chain, table) \
39 for ((chain) = (table); \
40 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
41 hlist_for_each_entry_safe((host), (pos), (next), \
42 (chain), h_hash)
43
44static unsigned long next_gc;
45static unsigned long nrhosts;
46static DEFINE_MUTEX(nlm_host_mutex);
47
48static void nlm_gc_hosts(void);
49
50struct nlm_lookup_host_info {
51 const int server; /* search for server|client */
52 const struct sockaddr *sap; /* address to search for */
53 const size_t salen; /* it's length */
54 const unsigned short protocol; /* transport to search for*/
55 const u32 version; /* NLM version to search for */
56 const char *hostname; /* remote's hostname */
57 const size_t hostname_len; /* it's length */
58 const int noresvport; /* use non-priv port */
59 struct net *net; /* network namespace to bind */
60};
61
62/*
63 * Hash function must work well on big- and little-endian platforms
64 */
65static unsigned int __nlm_hash32(const __be32 n)
66{
67 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
68 return hash ^ (hash >> 8);
69}
70
71static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
72{
73 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
74 return __nlm_hash32(sin->sin_addr.s_addr);
75}
76
77static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
78{
79 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
80 const struct in6_addr addr = sin6->sin6_addr;
81 return __nlm_hash32(addr.s6_addr32[0]) ^
82 __nlm_hash32(addr.s6_addr32[1]) ^
83 __nlm_hash32(addr.s6_addr32[2]) ^
84 __nlm_hash32(addr.s6_addr32[3]);
85}
86
87static unsigned int nlm_hash_address(const struct sockaddr *sap)
88{
89 unsigned int hash;
90
91 switch (sap->sa_family) {
92 case AF_INET:
93 hash = __nlm_hash_addr4(sap);
94 break;
95 case AF_INET6:
96 hash = __nlm_hash_addr6(sap);
97 break;
98 default:
99 hash = 0;
100 }
101 return hash & (NLM_HOST_NRHASH - 1);
102}
103
104/*
105 * Allocate and initialize an nlm_host. Common to both client and server.
106 */
107static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
108 struct nsm_handle *nsm)
109{
110 struct nlm_host *host = NULL;
111 unsigned long now = jiffies;
112
113 if (nsm != NULL)
114 atomic_inc(&nsm->sm_count);
115 else {
116 host = NULL;
117 nsm = nsm_get_handle(ni->sap, ni->salen,
118 ni->hostname, ni->hostname_len);
119 if (unlikely(nsm == NULL)) {
120 dprintk("lockd: %s failed; no nsm handle\n",
121 __func__);
122 goto out;
123 }
124 }
125
126 host = kmalloc(sizeof(*host), GFP_KERNEL);
127 if (unlikely(host == NULL)) {
128 dprintk("lockd: %s failed; no memory\n", __func__);
129 nsm_release(nsm);
130 goto out;
131 }
132
133 memcpy(nlm_addr(host), ni->sap, ni->salen);
134 host->h_addrlen = ni->salen;
135 rpc_set_port(nlm_addr(host), 0);
136 host->h_srcaddrlen = 0;
137
138 host->h_rpcclnt = NULL;
139 host->h_name = nsm->sm_name;
140 host->h_version = ni->version;
141 host->h_proto = ni->protocol;
142 host->h_reclaiming = 0;
143 host->h_server = ni->server;
144 host->h_noresvport = ni->noresvport;
145 host->h_inuse = 0;
146 init_waitqueue_head(&host->h_gracewait);
147 init_rwsem(&host->h_rwsem);
148 host->h_state = 0;
149 host->h_nsmstate = 0;
150 host->h_pidcount = 0;
151 atomic_set(&host->h_count, 1);
152 mutex_init(&host->h_mutex);
153 host->h_nextrebind = now + NLM_HOST_REBIND;
154 host->h_expires = now + NLM_HOST_EXPIRE;
155 INIT_LIST_HEAD(&host->h_lockowners);
156 spin_lock_init(&host->h_lock);
157 INIT_LIST_HEAD(&host->h_granted);
158 INIT_LIST_HEAD(&host->h_reclaim);
159 host->h_nsmhandle = nsm;
160 host->h_addrbuf = nsm->sm_addrbuf;
161 host->net = ni->net;
162
163out:
164 return host;
165}
166
167/*
168 * Destroy an nlm_host and free associated resources
169 *
170 * Caller must hold nlm_host_mutex.
171 */
172static void nlm_destroy_host_locked(struct nlm_host *host)
173{
174 struct rpc_clnt *clnt;
175
176 dprintk("lockd: destroy host %s\n", host->h_name);
177
178 BUG_ON(!list_empty(&host->h_lockowners));
179 BUG_ON(atomic_read(&host->h_count));
180
181 hlist_del_init(&host->h_hash);
182
183 nsm_unmonitor(host);
184 nsm_release(host->h_nsmhandle);
185
186 clnt = host->h_rpcclnt;
187 if (clnt != NULL)
188 rpc_shutdown_client(clnt);
189 kfree(host);
190
191 nrhosts--;
192}
193
194/**
195 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
196 * @sap: network address of server
197 * @salen: length of server address
198 * @protocol: transport protocol to use
199 * @version: NLM protocol version
200 * @hostname: '\0'-terminated hostname of server
201 * @noresvport: 1 if non-privileged port should be used
202 *
203 * Returns an nlm_host structure that matches the passed-in
204 * [server address, transport protocol, NLM version, server hostname].
205 * If one doesn't already exist in the host cache, a new handle is
206 * created and returned.
207 */
208struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
209 const size_t salen,
210 const unsigned short protocol,
211 const u32 version,
212 const char *hostname,
213 int noresvport,
214 struct net *net)
215{
216 struct nlm_lookup_host_info ni = {
217 .server = 0,
218 .sap = sap,
219 .salen = salen,
220 .protocol = protocol,
221 .version = version,
222 .hostname = hostname,
223 .hostname_len = strlen(hostname),
224 .noresvport = noresvport,
225 .net = net,
226 };
227 struct hlist_head *chain;
228 struct hlist_node *pos;
229 struct nlm_host *host;
230 struct nsm_handle *nsm = NULL;
231
232 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
233 (hostname ? hostname : "<none>"), version,
234 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
235
236 mutex_lock(&nlm_host_mutex);
237
238 chain = &nlm_client_hosts[nlm_hash_address(sap)];
239 hlist_for_each_entry(host, pos, chain, h_hash) {
240 if (host->net != net)
241 continue;
242 if (!rpc_cmp_addr(nlm_addr(host), sap))
243 continue;
244
245 /* Same address. Share an NSM handle if we already have one */
246 if (nsm == NULL)
247 nsm = host->h_nsmhandle;
248
249 if (host->h_proto != protocol)
250 continue;
251 if (host->h_version != version)
252 continue;
253
254 nlm_get_host(host);
255 dprintk("lockd: %s found host %s (%s)\n", __func__,
256 host->h_name, host->h_addrbuf);
257 goto out;
258 }
259
260 host = nlm_alloc_host(&ni, nsm);
261 if (unlikely(host == NULL))
262 goto out;
263
264 hlist_add_head(&host->h_hash, chain);
265 nrhosts++;
266
267 dprintk("lockd: %s created host %s (%s)\n", __func__,
268 host->h_name, host->h_addrbuf);
269
270out:
271 mutex_unlock(&nlm_host_mutex);
272 return host;
273}
274
275/**
276 * nlmclnt_release_host - release client nlm_host
277 * @host: nlm_host to release
278 *
279 */
280void nlmclnt_release_host(struct nlm_host *host)
281{
282 if (host == NULL)
283 return;
284
285 dprintk("lockd: release client host %s\n", host->h_name);
286
287 BUG_ON(atomic_read(&host->h_count) < 0);
288 BUG_ON(host->h_server);
289
290 if (atomic_dec_and_test(&host->h_count)) {
291 BUG_ON(!list_empty(&host->h_lockowners));
292 BUG_ON(!list_empty(&host->h_granted));
293 BUG_ON(!list_empty(&host->h_reclaim));
294
295 mutex_lock(&nlm_host_mutex);
296 nlm_destroy_host_locked(host);
297 mutex_unlock(&nlm_host_mutex);
298 }
299}
300
301/**
302 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
303 * @rqstp: incoming NLM request
304 * @hostname: name of client host
305 * @hostname_len: length of client hostname
306 *
307 * Returns an nlm_host structure that matches the [client address,
308 * transport protocol, NLM version, client hostname] of the passed-in
309 * NLM request. If one doesn't already exist in the host cache, a
310 * new handle is created and returned.
311 *
312 * Before possibly creating a new nlm_host, construct a sockaddr
313 * for a specific source address in case the local system has
314 * multiple network addresses. The family of the address in
315 * rq_daddr is guaranteed to be the same as the family of the
316 * address in rq_addr, so it's safe to use the same family for
317 * the source address.
318 */
319struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
320 const char *hostname,
321 const size_t hostname_len)
322{
323 struct hlist_head *chain;
324 struct hlist_node *pos;
325 struct nlm_host *host = NULL;
326 struct nsm_handle *nsm = NULL;
327 struct sockaddr *src_sap = svc_daddr(rqstp);
328 size_t src_len = rqstp->rq_daddrlen;
329 struct net *net = rqstp->rq_xprt->xpt_net;
330 struct nlm_lookup_host_info ni = {
331 .server = 1,
332 .sap = svc_addr(rqstp),
333 .salen = rqstp->rq_addrlen,
334 .protocol = rqstp->rq_prot,
335 .version = rqstp->rq_vers,
336 .hostname = hostname,
337 .hostname_len = hostname_len,
338 .net = net,
339 };
340
341 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
342 (int)hostname_len, hostname, rqstp->rq_vers,
343 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
344
345 mutex_lock(&nlm_host_mutex);
346
347 if (time_after_eq(jiffies, next_gc))
348 nlm_gc_hosts();
349
350 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
351 hlist_for_each_entry(host, pos, chain, h_hash) {
352 if (host->net != net)
353 continue;
354 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
355 continue;
356
357 /* Same address. Share an NSM handle if we already have one */
358 if (nsm == NULL)
359 nsm = host->h_nsmhandle;
360
361 if (host->h_proto != ni.protocol)
362 continue;
363 if (host->h_version != ni.version)
364 continue;
365 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
366 continue;
367
368 /* Move to head of hash chain. */
369 hlist_del(&host->h_hash);
370 hlist_add_head(&host->h_hash, chain);
371
372 nlm_get_host(host);
373 dprintk("lockd: %s found host %s (%s)\n",
374 __func__, host->h_name, host->h_addrbuf);
375 goto out;
376 }
377
378 host = nlm_alloc_host(&ni, nsm);
379 if (unlikely(host == NULL))
380 goto out;
381
382 memcpy(nlm_srcaddr(host), src_sap, src_len);
383 host->h_srcaddrlen = src_len;
384 hlist_add_head(&host->h_hash, chain);
385 nrhosts++;
386
387 dprintk("lockd: %s created host %s (%s)\n",
388 __func__, host->h_name, host->h_addrbuf);
389
390out:
391 mutex_unlock(&nlm_host_mutex);
392 return host;
393}
394
395/**
396 * nlmsvc_release_host - release server nlm_host
397 * @host: nlm_host to release
398 *
399 * Host is destroyed later in nlm_gc_host().
400 */
401void nlmsvc_release_host(struct nlm_host *host)
402{
403 if (host == NULL)
404 return;
405
406 dprintk("lockd: release server host %s\n", host->h_name);
407
408 BUG_ON(atomic_read(&host->h_count) < 0);
409 BUG_ON(!host->h_server);
410 atomic_dec(&host->h_count);
411}
412
413/*
414 * Create the NLM RPC client for an NLM peer
415 */
416struct rpc_clnt *
417nlm_bind_host(struct nlm_host *host)
418{
419 struct rpc_clnt *clnt;
420
421 dprintk("lockd: nlm_bind_host %s (%s)\n",
422 host->h_name, host->h_addrbuf);
423
424 /* Lock host handle */
425 mutex_lock(&host->h_mutex);
426
427 /* If we've already created an RPC client, check whether
428 * RPC rebind is required
429 */
430 if ((clnt = host->h_rpcclnt) != NULL) {
431 if (time_after_eq(jiffies, host->h_nextrebind)) {
432 rpc_force_rebind(clnt);
433 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
434 dprintk("lockd: next rebind in %lu jiffies\n",
435 host->h_nextrebind - jiffies);
436 }
437 } else {
438 unsigned long increment = nlmsvc_timeout;
439 struct rpc_timeout timeparms = {
440 .to_initval = increment,
441 .to_increment = increment,
442 .to_maxval = increment * 6UL,
443 .to_retries = 5U,
444 };
445 struct rpc_create_args args = {
446 .net = host->net,
447 .protocol = host->h_proto,
448 .address = nlm_addr(host),
449 .addrsize = host->h_addrlen,
450 .timeout = &timeparms,
451 .servername = host->h_name,
452 .program = &nlm_program,
453 .version = host->h_version,
454 .authflavor = RPC_AUTH_UNIX,
455 .flags = (RPC_CLNT_CREATE_NOPING |
456 RPC_CLNT_CREATE_AUTOBIND),
457 };
458
459 /*
460 * lockd retries server side blocks automatically so we want
461 * those to be soft RPC calls. Client side calls need to be
462 * hard RPC tasks.
463 */
464 if (!host->h_server)
465 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
466 if (host->h_noresvport)
467 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
468 if (host->h_srcaddrlen)
469 args.saddress = nlm_srcaddr(host);
470
471 clnt = rpc_create(&args);
472 if (!IS_ERR(clnt))
473 host->h_rpcclnt = clnt;
474 else {
475 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
476 clnt = NULL;
477 }
478 }
479
480 mutex_unlock(&host->h_mutex);
481 return clnt;
482}
483
484/*
485 * Force a portmap lookup of the remote lockd port
486 */
487void
488nlm_rebind_host(struct nlm_host *host)
489{
490 dprintk("lockd: rebind host %s\n", host->h_name);
491 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
492 rpc_force_rebind(host->h_rpcclnt);
493 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
494 }
495}
496
497/*
498 * Increment NLM host count
499 */
500struct nlm_host * nlm_get_host(struct nlm_host *host)
501{
502 if (host) {
503 dprintk("lockd: get host %s\n", host->h_name);
504 atomic_inc(&host->h_count);
505 host->h_expires = jiffies + NLM_HOST_EXPIRE;
506 }
507 return host;
508}
509
510static struct nlm_host *next_host_state(struct hlist_head *cache,
511 struct nsm_handle *nsm,
512 const struct nlm_reboot *info)
513{
514 struct nlm_host *host;
515 struct hlist_head *chain;
516 struct hlist_node *pos;
517
518 mutex_lock(&nlm_host_mutex);
519 for_each_host(host, pos, chain, cache) {
520 if (host->h_nsmhandle == nsm
521 && host->h_nsmstate != info->state) {
522 host->h_nsmstate = info->state;
523 host->h_state++;
524
525 nlm_get_host(host);
526 mutex_unlock(&nlm_host_mutex);
527 return host;
528 }
529 }
530
531 mutex_unlock(&nlm_host_mutex);
532 return NULL;
533}
534
535/**
536 * nlm_host_rebooted - Release all resources held by rebooted host
537 * @info: pointer to decoded results of NLM_SM_NOTIFY call
538 *
539 * We were notified that the specified host has rebooted. Release
540 * all resources held by that peer.
541 */
542void nlm_host_rebooted(const struct nlm_reboot *info)
543{
544 struct nsm_handle *nsm;
545 struct nlm_host *host;
546
547 nsm = nsm_reboot_lookup(info);
548 if (unlikely(nsm == NULL))
549 return;
550
551 /* Mark all hosts tied to this NSM state as having rebooted.
552 * We run the loop repeatedly, because we drop the host table
553 * lock for this.
554 * To avoid processing a host several times, we match the nsmstate.
555 */
556 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
557 nlmsvc_free_host_resources(host);
558 nlmsvc_release_host(host);
559 }
560 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
561 nlmclnt_recovery(host);
562 nlmclnt_release_host(host);
563 }
564
565 nsm_release(nsm);
566}
567
568void
569nlm_shutdown_hosts_net(struct net *net)
570{
571 struct hlist_head *chain;
572 struct hlist_node *pos;
573 struct nlm_host *host;
574
575 dprintk("lockd: shutting down host module\n");
576 mutex_lock(&nlm_host_mutex);
577
578 /* First, make all hosts eligible for gc */
579 dprintk("lockd: nuking all hosts...\n");
580 for_each_host(host, pos, chain, nlm_server_hosts) {
581 if (net && host->net != net)
582 continue;
583 host->h_expires = jiffies - 1;
584 if (host->h_rpcclnt) {
585 rpc_shutdown_client(host->h_rpcclnt);
586 host->h_rpcclnt = NULL;
587 }
588 }
589
590 /* Then, perform a garbage collection pass */
591 nlm_gc_hosts();
592 mutex_unlock(&nlm_host_mutex);
593}
594
595/*
596 * Shut down the hosts module.
597 * Note that this routine is called only at server shutdown time.
598 */
599void
600nlm_shutdown_hosts(void)
601{
602 struct hlist_head *chain;
603 struct hlist_node *pos;
604 struct nlm_host *host;
605
606 nlm_shutdown_hosts_net(NULL);
607
608 /* complain if any hosts are left */
609 if (nrhosts != 0) {
610 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
611 dprintk("lockd: %lu hosts left:\n", nrhosts);
612 for_each_host(host, pos, chain, nlm_server_hosts) {
613 dprintk(" %s (cnt %d use %d exp %ld net %p)\n",
614 host->h_name, atomic_read(&host->h_count),
615 host->h_inuse, host->h_expires, host->net);
616 }
617 }
618}
619
620/*
621 * Garbage collect any unused NLM hosts.
622 * This GC combines reference counting for async operations with
623 * mark & sweep for resources held by remote clients.
624 */
625static void
626nlm_gc_hosts(void)
627{
628 struct hlist_head *chain;
629 struct hlist_node *pos, *next;
630 struct nlm_host *host;
631
632 dprintk("lockd: host garbage collection\n");
633 for_each_host(host, pos, chain, nlm_server_hosts)
634 host->h_inuse = 0;
635
636 /* Mark all hosts that hold locks, blocks or shares */
637 nlmsvc_mark_resources();
638
639 for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
640 if (atomic_read(&host->h_count) || host->h_inuse
641 || time_before(jiffies, host->h_expires)) {
642 dprintk("nlm_gc_hosts skipping %s "
643 "(cnt %d use %d exp %ld)\n",
644 host->h_name, atomic_read(&host->h_count),
645 host->h_inuse, host->h_expires);
646 continue;
647 }
648 nlm_destroy_host_locked(host);
649 }
650
651 next_gc = jiffies + NLM_HOST_COLLECT;
652}