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