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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/host.c
4 *
5 * Management for NLM peer hosts. The nlm_host struct is shared
6 * between client and server implementation. The only reason to
7 * do so is to reduce code bloat.
8 *
9 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
10 */
11
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/in.h>
15#include <linux/in6.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/addr.h>
18#include <linux/sunrpc/svc.h>
19#include <linux/lockd/lockd.h>
20#include <linux/mutex.h>
21
22#include <linux/sunrpc/svc_xprt.h>
23
24#include <net/ipv6.h>
25
26#include "netns.h"
27
28#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
29#define NLM_HOST_NRHASH 32
30#define NLM_HOST_REBIND (60 * HZ)
31#define NLM_HOST_EXPIRE (300 * HZ)
32#define NLM_HOST_COLLECT (120 * HZ)
33
34static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
35static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
36
37#define for_each_host(host, chain, table) \
38 for ((chain) = (table); \
39 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
40 hlist_for_each_entry((host), (chain), h_hash)
41
42#define for_each_host_safe(host, next, chain, table) \
43 for ((chain) = (table); \
44 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
45 hlist_for_each_entry_safe((host), (next), \
46 (chain), h_hash)
47
48static unsigned long nrhosts;
49static DEFINE_MUTEX(nlm_host_mutex);
50
51static void nlm_gc_hosts(struct net *net);
52
53struct nlm_lookup_host_info {
54 const int server; /* search for server|client */
55 const struct sockaddr *sap; /* address to search for */
56 const size_t salen; /* it's length */
57 const unsigned short protocol; /* transport to search for*/
58 const u32 version; /* NLM version to search for */
59 const char *hostname; /* remote's hostname */
60 const size_t hostname_len; /* it's length */
61 const int noresvport; /* use non-priv port */
62 struct net *net; /* network namespace to bind */
63 const struct cred *cred;
64};
65
66/*
67 * Hash function must work well on big- and little-endian platforms
68 */
69static unsigned int __nlm_hash32(const __be32 n)
70{
71 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
72 return hash ^ (hash >> 8);
73}
74
75static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
76{
77 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
78 return __nlm_hash32(sin->sin_addr.s_addr);
79}
80
81static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
82{
83 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
84 const struct in6_addr addr = sin6->sin6_addr;
85 return __nlm_hash32(addr.s6_addr32[0]) ^
86 __nlm_hash32(addr.s6_addr32[1]) ^
87 __nlm_hash32(addr.s6_addr32[2]) ^
88 __nlm_hash32(addr.s6_addr32[3]);
89}
90
91static unsigned int nlm_hash_address(const struct sockaddr *sap)
92{
93 unsigned int hash;
94
95 switch (sap->sa_family) {
96 case AF_INET:
97 hash = __nlm_hash_addr4(sap);
98 break;
99 case AF_INET6:
100 hash = __nlm_hash_addr6(sap);
101 break;
102 default:
103 hash = 0;
104 }
105 return hash & (NLM_HOST_NRHASH - 1);
106}
107
108/*
109 * Allocate and initialize an nlm_host. Common to both client and server.
110 */
111static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
112 struct nsm_handle *nsm)
113{
114 struct nlm_host *host = NULL;
115 unsigned long now = jiffies;
116
117 if (nsm != NULL)
118 refcount_inc(&nsm->sm_count);
119 else {
120 host = NULL;
121 nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
122 ni->hostname, ni->hostname_len);
123 if (unlikely(nsm == NULL)) {
124 dprintk("lockd: %s failed; no nsm handle\n",
125 __func__);
126 goto out;
127 }
128 }
129
130 host = kmalloc(sizeof(*host), GFP_KERNEL);
131 if (unlikely(host == NULL)) {
132 dprintk("lockd: %s failed; no memory\n", __func__);
133 nsm_release(nsm);
134 goto out;
135 }
136
137 memcpy(nlm_addr(host), ni->sap, ni->salen);
138 host->h_addrlen = ni->salen;
139 rpc_set_port(nlm_addr(host), 0);
140 host->h_srcaddrlen = 0;
141
142 host->h_rpcclnt = NULL;
143 host->h_name = nsm->sm_name;
144 host->h_version = ni->version;
145 host->h_proto = ni->protocol;
146 host->h_reclaiming = 0;
147 host->h_server = ni->server;
148 host->h_noresvport = ni->noresvport;
149 host->h_inuse = 0;
150 init_waitqueue_head(&host->h_gracewait);
151 init_rwsem(&host->h_rwsem);
152 host->h_state = 0;
153 host->h_nsmstate = 0;
154 host->h_pidcount = 0;
155 refcount_set(&host->h_count, 1);
156 mutex_init(&host->h_mutex);
157 host->h_nextrebind = now + NLM_HOST_REBIND;
158 host->h_expires = now + NLM_HOST_EXPIRE;
159 INIT_LIST_HEAD(&host->h_lockowners);
160 spin_lock_init(&host->h_lock);
161 INIT_LIST_HEAD(&host->h_granted);
162 INIT_LIST_HEAD(&host->h_reclaim);
163 host->h_nsmhandle = nsm;
164 host->h_addrbuf = nsm->sm_addrbuf;
165 host->net = ni->net;
166 host->h_cred = get_cred(ni->cred);
167 strscpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
168
169out:
170 return host;
171}
172
173/*
174 * Destroy an nlm_host and free associated resources
175 *
176 * Caller must hold nlm_host_mutex.
177 */
178static void nlm_destroy_host_locked(struct nlm_host *host)
179{
180 struct rpc_clnt *clnt;
181 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
182
183 dprintk("lockd: destroy host %s\n", host->h_name);
184
185 hlist_del_init(&host->h_hash);
186
187 nsm_unmonitor(host);
188 nsm_release(host->h_nsmhandle);
189
190 clnt = host->h_rpcclnt;
191 if (clnt != NULL)
192 rpc_shutdown_client(clnt);
193 put_cred(host->h_cred);
194 kfree(host);
195
196 ln->nrhosts--;
197 nrhosts--;
198}
199
200/**
201 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
202 * @sap: network address of server
203 * @salen: length of server address
204 * @protocol: transport protocol to use
205 * @version: NLM protocol version
206 * @hostname: '\0'-terminated hostname of server
207 * @noresvport: 1 if non-privileged port should be used
208 * @net: pointer to net namespace
209 * @cred: pointer to cred
210 *
211 * Returns an nlm_host structure that matches the passed-in
212 * [server address, transport protocol, NLM version, server hostname].
213 * If one doesn't already exist in the host cache, a new handle is
214 * created and returned.
215 */
216struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
217 const size_t salen,
218 const unsigned short protocol,
219 const u32 version,
220 const char *hostname,
221 int noresvport,
222 struct net *net,
223 const struct cred *cred)
224{
225 struct nlm_lookup_host_info ni = {
226 .server = 0,
227 .sap = sap,
228 .salen = salen,
229 .protocol = protocol,
230 .version = version,
231 .hostname = hostname,
232 .hostname_len = strlen(hostname),
233 .noresvport = noresvport,
234 .net = net,
235 .cred = cred,
236 };
237 struct hlist_head *chain;
238 struct nlm_host *host;
239 struct nsm_handle *nsm = NULL;
240 struct lockd_net *ln = net_generic(net, lockd_net_id);
241
242 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
243 (hostname ? hostname : "<none>"), version,
244 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
245
246 mutex_lock(&nlm_host_mutex);
247
248 chain = &nlm_client_hosts[nlm_hash_address(sap)];
249 hlist_for_each_entry(host, chain, h_hash) {
250 if (host->net != net)
251 continue;
252 if (!rpc_cmp_addr(nlm_addr(host), sap))
253 continue;
254
255 /* Same address. Share an NSM handle if we already have one */
256 if (nsm == NULL)
257 nsm = host->h_nsmhandle;
258
259 if (host->h_proto != protocol)
260 continue;
261 if (host->h_version != version)
262 continue;
263
264 nlm_get_host(host);
265 dprintk("lockd: %s found host %s (%s)\n", __func__,
266 host->h_name, host->h_addrbuf);
267 goto out;
268 }
269
270 host = nlm_alloc_host(&ni, nsm);
271 if (unlikely(host == NULL))
272 goto out;
273
274 hlist_add_head(&host->h_hash, chain);
275 ln->nrhosts++;
276 nrhosts++;
277
278 dprintk("lockd: %s created host %s (%s)\n", __func__,
279 host->h_name, host->h_addrbuf);
280
281out:
282 mutex_unlock(&nlm_host_mutex);
283 return host;
284}
285
286/**
287 * nlmclnt_release_host - release client nlm_host
288 * @host: nlm_host to release
289 *
290 */
291void nlmclnt_release_host(struct nlm_host *host)
292{
293 if (host == NULL)
294 return;
295
296 dprintk("lockd: release client host %s\n", host->h_name);
297
298 WARN_ON_ONCE(host->h_server);
299
300 if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
301 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
302 WARN_ON_ONCE(!list_empty(&host->h_granted));
303 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
304
305 nlm_destroy_host_locked(host);
306 mutex_unlock(&nlm_host_mutex);
307 }
308}
309
310/**
311 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
312 * @rqstp: incoming NLM request
313 * @hostname: name of client host
314 * @hostname_len: length of client hostname
315 *
316 * Returns an nlm_host structure that matches the [client address,
317 * transport protocol, NLM version, client hostname] of the passed-in
318 * NLM request. If one doesn't already exist in the host cache, a
319 * new handle is created and returned.
320 *
321 * Before possibly creating a new nlm_host, construct a sockaddr
322 * for a specific source address in case the local system has
323 * multiple network addresses. The family of the address in
324 * rq_daddr is guaranteed to be the same as the family of the
325 * address in rq_addr, so it's safe to use the same family for
326 * the source address.
327 */
328struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
329 const char *hostname,
330 const size_t hostname_len)
331{
332 struct hlist_head *chain;
333 struct nlm_host *host = NULL;
334 struct nsm_handle *nsm = NULL;
335 struct sockaddr *src_sap = svc_daddr(rqstp);
336 size_t src_len = rqstp->rq_daddrlen;
337 struct net *net = SVC_NET(rqstp);
338 struct nlm_lookup_host_info ni = {
339 .server = 1,
340 .sap = svc_addr(rqstp),
341 .salen = rqstp->rq_addrlen,
342 .protocol = rqstp->rq_prot,
343 .version = rqstp->rq_vers,
344 .hostname = hostname,
345 .hostname_len = hostname_len,
346 .net = net,
347 };
348 struct lockd_net *ln = net_generic(net, lockd_net_id);
349
350 dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
351 (int)hostname_len, hostname, rqstp->rq_vers,
352 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
353
354 mutex_lock(&nlm_host_mutex);
355
356 if (time_after_eq(jiffies, ln->next_gc))
357 nlm_gc_hosts(net);
358
359 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
360 hlist_for_each_entry(host, chain, h_hash) {
361 if (host->net != net)
362 continue;
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 ln->nrhosts++;
395 nrhosts++;
396
397 refcount_inc(&host->h_count);
398
399 dprintk("lockd: %s created host %s (%s)\n",
400 __func__, host->h_name, host->h_addrbuf);
401
402out:
403 mutex_unlock(&nlm_host_mutex);
404 return host;
405}
406
407/**
408 * nlmsvc_release_host - release server nlm_host
409 * @host: nlm_host to release
410 *
411 * Host is destroyed later in nlm_gc_host().
412 */
413void nlmsvc_release_host(struct nlm_host *host)
414{
415 if (host == NULL)
416 return;
417
418 dprintk("lockd: release server host %s\n", host->h_name);
419
420 WARN_ON_ONCE(!host->h_server);
421 refcount_dec(&host->h_count);
422}
423
424/*
425 * Create the NLM RPC client for an NLM peer
426 */
427struct rpc_clnt *
428nlm_bind_host(struct nlm_host *host)
429{
430 struct rpc_clnt *clnt;
431
432 dprintk("lockd: nlm_bind_host %s (%s)\n",
433 host->h_name, host->h_addrbuf);
434
435 /* Lock host handle */
436 mutex_lock(&host->h_mutex);
437
438 /* If we've already created an RPC client, check whether
439 * RPC rebind is required
440 */
441 if ((clnt = host->h_rpcclnt) != NULL) {
442 nlm_rebind_host(host);
443 } else {
444 unsigned long increment = nlmsvc_timeout;
445 struct rpc_timeout timeparms = {
446 .to_initval = increment,
447 .to_increment = increment,
448 .to_maxval = increment * 6UL,
449 .to_retries = 5U,
450 };
451 struct rpc_create_args args = {
452 .net = host->net,
453 .protocol = host->h_proto,
454 .address = nlm_addr(host),
455 .addrsize = host->h_addrlen,
456 .timeout = &timeparms,
457 .servername = host->h_name,
458 .program = &nlm_program,
459 .version = host->h_version,
460 .authflavor = RPC_AUTH_UNIX,
461 .flags = (RPC_CLNT_CREATE_NOPING |
462 RPC_CLNT_CREATE_AUTOBIND |
463 RPC_CLNT_CREATE_REUSEPORT),
464 .cred = host->h_cred,
465 };
466
467 /*
468 * lockd retries server side blocks automatically so we want
469 * those to be soft RPC calls. Client side calls need to be
470 * hard RPC tasks.
471 */
472 if (!host->h_server)
473 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
474 if (host->h_noresvport)
475 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
476 if (host->h_srcaddrlen)
477 args.saddress = nlm_srcaddr(host);
478
479 clnt = rpc_create(&args);
480 if (!IS_ERR(clnt))
481 host->h_rpcclnt = clnt;
482 else {
483 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
484 clnt = NULL;
485 }
486 }
487
488 mutex_unlock(&host->h_mutex);
489 return clnt;
490}
491
492/**
493 * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port
494 * @host: NLM host handle for peer
495 *
496 * This is not needed when using a connection-oriented protocol, such as TCP.
497 * The existing autobind mechanism is sufficient to force a rebind when
498 * required, e.g. on connection state transitions.
499 */
500void
501nlm_rebind_host(struct nlm_host *host)
502{
503 if (host->h_proto != IPPROTO_UDP)
504 return;
505
506 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
507 rpc_force_rebind(host->h_rpcclnt);
508 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
509 }
510}
511
512/*
513 * Increment NLM host count
514 */
515struct nlm_host * nlm_get_host(struct nlm_host *host)
516{
517 if (host) {
518 dprintk("lockd: get host %s\n", host->h_name);
519 refcount_inc(&host->h_count);
520 host->h_expires = jiffies + NLM_HOST_EXPIRE;
521 }
522 return host;
523}
524
525static struct nlm_host *next_host_state(struct hlist_head *cache,
526 struct nsm_handle *nsm,
527 const struct nlm_reboot *info)
528{
529 struct nlm_host *host;
530 struct hlist_head *chain;
531
532 mutex_lock(&nlm_host_mutex);
533 for_each_host(host, chain, cache) {
534 if (host->h_nsmhandle == nsm
535 && host->h_nsmstate != info->state) {
536 host->h_nsmstate = info->state;
537 host->h_state++;
538
539 nlm_get_host(host);
540 mutex_unlock(&nlm_host_mutex);
541 return host;
542 }
543 }
544
545 mutex_unlock(&nlm_host_mutex);
546 return NULL;
547}
548
549/**
550 * nlm_host_rebooted - Release all resources held by rebooted host
551 * @net: network namespace
552 * @info: pointer to decoded results of NLM_SM_NOTIFY call
553 *
554 * We were notified that the specified host has rebooted. Release
555 * all resources held by that peer.
556 */
557void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info)
558{
559 struct nsm_handle *nsm;
560 struct nlm_host *host;
561
562 nsm = nsm_reboot_lookup(net, info);
563 if (unlikely(nsm == NULL))
564 return;
565
566 /* Mark all hosts tied to this NSM state as having rebooted.
567 * We run the loop repeatedly, because we drop the host table
568 * lock for this.
569 * To avoid processing a host several times, we match the nsmstate.
570 */
571 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
572 nlmsvc_free_host_resources(host);
573 nlmsvc_release_host(host);
574 }
575 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
576 nlmclnt_recovery(host);
577 nlmclnt_release_host(host);
578 }
579
580 nsm_release(nsm);
581}
582
583static void nlm_complain_hosts(struct net *net)
584{
585 struct hlist_head *chain;
586 struct nlm_host *host;
587
588 if (net) {
589 struct lockd_net *ln = net_generic(net, lockd_net_id);
590
591 if (ln->nrhosts == 0)
592 return;
593 pr_warn("lockd: couldn't shutdown host module for net %x!\n",
594 net->ns.inum);
595 dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
596 net->ns.inum);
597 } else {
598 if (nrhosts == 0)
599 return;
600 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
601 dprintk("lockd: %lu hosts left:\n", nrhosts);
602 }
603
604 for_each_host(host, chain, nlm_server_hosts) {
605 if (net && host->net != net)
606 continue;
607 dprintk(" %s (cnt %d use %d exp %ld net %x)\n",
608 host->h_name, refcount_read(&host->h_count),
609 host->h_inuse, host->h_expires, host->net->ns.inum);
610 }
611}
612
613void
614nlm_shutdown_hosts_net(struct net *net)
615{
616 struct hlist_head *chain;
617 struct nlm_host *host;
618
619 mutex_lock(&nlm_host_mutex);
620
621 /* First, make all hosts eligible for gc */
622 dprintk("lockd: nuking all hosts in net %x...\n",
623 net ? net->ns.inum : 0);
624 for_each_host(host, chain, nlm_server_hosts) {
625 if (net && host->net != net)
626 continue;
627 host->h_expires = jiffies - 1;
628 if (host->h_rpcclnt) {
629 rpc_shutdown_client(host->h_rpcclnt);
630 host->h_rpcclnt = NULL;
631 }
632 }
633
634 /* Then, perform a garbage collection pass */
635 nlm_gc_hosts(net);
636 nlm_complain_hosts(net);
637 mutex_unlock(&nlm_host_mutex);
638}
639
640/*
641 * Shut down the hosts module.
642 * Note that this routine is called only at server shutdown time.
643 */
644void
645nlm_shutdown_hosts(void)
646{
647 dprintk("lockd: shutting down host module\n");
648 nlm_shutdown_hosts_net(NULL);
649}
650
651/*
652 * Garbage collect any unused NLM hosts.
653 * This GC combines reference counting for async operations with
654 * mark & sweep for resources held by remote clients.
655 */
656static void
657nlm_gc_hosts(struct net *net)
658{
659 struct hlist_head *chain;
660 struct hlist_node *next;
661 struct nlm_host *host;
662
663 dprintk("lockd: host garbage collection for net %x\n",
664 net ? net->ns.inum : 0);
665 for_each_host(host, chain, nlm_server_hosts) {
666 if (net && host->net != net)
667 continue;
668 host->h_inuse = 0;
669 }
670
671 /* Mark all hosts that hold locks, blocks or shares */
672 nlmsvc_mark_resources(net);
673
674 for_each_host_safe(host, next, chain, nlm_server_hosts) {
675 if (net && host->net != net)
676 continue;
677 if (host->h_inuse || time_before(jiffies, host->h_expires)) {
678 dprintk("nlm_gc_hosts skipping %s "
679 "(cnt %d use %d exp %ld net %x)\n",
680 host->h_name, refcount_read(&host->h_count),
681 host->h_inuse, host->h_expires,
682 host->net->ns.inum);
683 continue;
684 }
685 if (refcount_dec_if_one(&host->h_count))
686 nlm_destroy_host_locked(host);
687 }
688
689 if (net) {
690 struct lockd_net *ln = net_generic(net, lockd_net_id);
691
692 ln->next_gc = jiffies + NLM_HOST_COLLECT;
693 }
694}
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->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
165out:
166 return host;
167}
168
169/*
170 * Destroy an nlm_host and free associated resources
171 *
172 * Caller must hold nlm_host_mutex.
173 */
174static void nlm_destroy_host_locked(struct nlm_host *host)
175{
176 struct rpc_clnt *clnt;
177 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
178
179 dprintk("lockd: destroy host %s\n", host->h_name);
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 ln->nrhosts--;
192 nrhosts--;
193}
194
195/**
196 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
197 * @sap: network address of server
198 * @salen: length of server address
199 * @protocol: transport protocol to use
200 * @version: NLM protocol version
201 * @hostname: '\0'-terminated hostname of server
202 * @noresvport: 1 if non-privileged port should be used
203 *
204 * Returns an nlm_host structure that matches the passed-in
205 * [server address, transport protocol, NLM version, server hostname].
206 * If one doesn't already exist in the host cache, a new handle is
207 * created and returned.
208 */
209struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
210 const size_t salen,
211 const unsigned short protocol,
212 const u32 version,
213 const char *hostname,
214 int noresvport,
215 struct net *net)
216{
217 struct nlm_lookup_host_info ni = {
218 .server = 0,
219 .sap = sap,
220 .salen = salen,
221 .protocol = protocol,
222 .version = version,
223 .hostname = hostname,
224 .hostname_len = strlen(hostname),
225 .noresvport = noresvport,
226 .net = net,
227 };
228 struct hlist_head *chain;
229 struct nlm_host *host;
230 struct nsm_handle *nsm = NULL;
231 struct lockd_net *ln = net_generic(net, lockd_net_id);
232
233 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
234 (hostname ? hostname : "<none>"), version,
235 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
236
237 mutex_lock(&nlm_host_mutex);
238
239 chain = &nlm_client_hosts[nlm_hash_address(sap)];
240 hlist_for_each_entry(host, chain, h_hash) {
241 if (host->net != net)
242 continue;
243 if (!rpc_cmp_addr(nlm_addr(host), sap))
244 continue;
245
246 /* Same address. Share an NSM handle if we already have one */
247 if (nsm == NULL)
248 nsm = host->h_nsmhandle;
249
250 if (host->h_proto != protocol)
251 continue;
252 if (host->h_version != version)
253 continue;
254
255 nlm_get_host(host);
256 dprintk("lockd: %s found host %s (%s)\n", __func__,
257 host->h_name, host->h_addrbuf);
258 goto out;
259 }
260
261 host = nlm_alloc_host(&ni, nsm);
262 if (unlikely(host == NULL))
263 goto out;
264
265 hlist_add_head(&host->h_hash, chain);
266 ln->nrhosts++;
267 nrhosts++;
268
269 dprintk("lockd: %s created host %s (%s)\n", __func__,
270 host->h_name, host->h_addrbuf);
271
272out:
273 mutex_unlock(&nlm_host_mutex);
274 return host;
275}
276
277/**
278 * nlmclnt_release_host - release client nlm_host
279 * @host: nlm_host to release
280 *
281 */
282void nlmclnt_release_host(struct nlm_host *host)
283{
284 if (host == NULL)
285 return;
286
287 dprintk("lockd: release client host %s\n", host->h_name);
288
289 WARN_ON_ONCE(host->h_server);
290
291 if (atomic_dec_and_test(&host->h_count)) {
292 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
293 WARN_ON_ONCE(!list_empty(&host->h_granted));
294 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
295
296 mutex_lock(&nlm_host_mutex);
297 nlm_destroy_host_locked(host);
298 mutex_unlock(&nlm_host_mutex);
299 }
300}
301
302/**
303 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
304 * @rqstp: incoming NLM request
305 * @hostname: name of client host
306 * @hostname_len: length of client hostname
307 *
308 * Returns an nlm_host structure that matches the [client address,
309 * transport protocol, NLM version, client hostname] of the passed-in
310 * NLM request. If one doesn't already exist in the host cache, a
311 * new handle is created and returned.
312 *
313 * Before possibly creating a new nlm_host, construct a sockaddr
314 * for a specific source address in case the local system has
315 * multiple network addresses. The family of the address in
316 * rq_daddr is guaranteed to be the same as the family of the
317 * address in rq_addr, so it's safe to use the same family for
318 * the source address.
319 */
320struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
321 const char *hostname,
322 const size_t hostname_len)
323{
324 struct hlist_head *chain;
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 = SVC_NET(rqstp);
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 struct lockd_net *ln = net_generic(net, lockd_net_id);
341
342 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
343 (int)hostname_len, hostname, rqstp->rq_vers,
344 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
345
346 mutex_lock(&nlm_host_mutex);
347
348 if (time_after_eq(jiffies, ln->next_gc))
349 nlm_gc_hosts(net);
350
351 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
352 hlist_for_each_entry(host, chain, h_hash) {
353 if (host->net != net)
354 continue;
355 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
356 continue;
357
358 /* Same address. Share an NSM handle if we already have one */
359 if (nsm == NULL)
360 nsm = host->h_nsmhandle;
361
362 if (host->h_proto != ni.protocol)
363 continue;
364 if (host->h_version != ni.version)
365 continue;
366 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
367 continue;
368
369 /* Move to head of hash chain. */
370 hlist_del(&host->h_hash);
371 hlist_add_head(&host->h_hash, chain);
372
373 nlm_get_host(host);
374 dprintk("lockd: %s found host %s (%s)\n",
375 __func__, host->h_name, host->h_addrbuf);
376 goto out;
377 }
378
379 host = nlm_alloc_host(&ni, nsm);
380 if (unlikely(host == NULL))
381 goto out;
382
383 memcpy(nlm_srcaddr(host), src_sap, src_len);
384 host->h_srcaddrlen = src_len;
385 hlist_add_head(&host->h_hash, chain);
386 ln->nrhosts++;
387 nrhosts++;
388
389 dprintk("lockd: %s created host %s (%s)\n",
390 __func__, host->h_name, host->h_addrbuf);
391
392out:
393 mutex_unlock(&nlm_host_mutex);
394 return host;
395}
396
397/**
398 * nlmsvc_release_host - release server nlm_host
399 * @host: nlm_host to release
400 *
401 * Host is destroyed later in nlm_gc_host().
402 */
403void nlmsvc_release_host(struct nlm_host *host)
404{
405 if (host == NULL)
406 return;
407
408 dprintk("lockd: release server host %s\n", host->h_name);
409
410 WARN_ON_ONCE(!host->h_server);
411 atomic_dec(&host->h_count);
412}
413
414/*
415 * Create the NLM RPC client for an NLM peer
416 */
417struct rpc_clnt *
418nlm_bind_host(struct nlm_host *host)
419{
420 struct rpc_clnt *clnt;
421
422 dprintk("lockd: nlm_bind_host %s (%s)\n",
423 host->h_name, host->h_addrbuf);
424
425 /* Lock host handle */
426 mutex_lock(&host->h_mutex);
427
428 /* If we've already created an RPC client, check whether
429 * RPC rebind is required
430 */
431 if ((clnt = host->h_rpcclnt) != NULL) {
432 if (time_after_eq(jiffies, host->h_nextrebind)) {
433 rpc_force_rebind(clnt);
434 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
435 dprintk("lockd: next rebind in %lu jiffies\n",
436 host->h_nextrebind - jiffies);
437 }
438 } else {
439 unsigned long increment = nlmsvc_timeout;
440 struct rpc_timeout timeparms = {
441 .to_initval = increment,
442 .to_increment = increment,
443 .to_maxval = increment * 6UL,
444 .to_retries = 5U,
445 };
446 struct rpc_create_args args = {
447 .net = host->net,
448 .protocol = host->h_proto,
449 .address = nlm_addr(host),
450 .addrsize = host->h_addrlen,
451 .timeout = &timeparms,
452 .servername = host->h_name,
453 .program = &nlm_program,
454 .version = host->h_version,
455 .authflavor = RPC_AUTH_UNIX,
456 .flags = (RPC_CLNT_CREATE_NOPING |
457 RPC_CLNT_CREATE_AUTOBIND),
458 };
459
460 /*
461 * lockd retries server side blocks automatically so we want
462 * those to be soft RPC calls. Client side calls need to be
463 * hard RPC tasks.
464 */
465 if (!host->h_server)
466 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
467 if (host->h_noresvport)
468 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
469 if (host->h_srcaddrlen)
470 args.saddress = nlm_srcaddr(host);
471
472 clnt = rpc_create(&args);
473 if (!IS_ERR(clnt))
474 host->h_rpcclnt = clnt;
475 else {
476 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
477 clnt = NULL;
478 }
479 }
480
481 mutex_unlock(&host->h_mutex);
482 return clnt;
483}
484
485/*
486 * Force a portmap lookup of the remote lockd port
487 */
488void
489nlm_rebind_host(struct nlm_host *host)
490{
491 dprintk("lockd: rebind host %s\n", host->h_name);
492 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
493 rpc_force_rebind(host->h_rpcclnt);
494 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
495 }
496}
497
498/*
499 * Increment NLM host count
500 */
501struct nlm_host * nlm_get_host(struct nlm_host *host)
502{
503 if (host) {
504 dprintk("lockd: get host %s\n", host->h_name);
505 atomic_inc(&host->h_count);
506 host->h_expires = jiffies + NLM_HOST_EXPIRE;
507 }
508 return host;
509}
510
511static struct nlm_host *next_host_state(struct hlist_head *cache,
512 struct nsm_handle *nsm,
513 const struct nlm_reboot *info)
514{
515 struct nlm_host *host;
516 struct hlist_head *chain;
517
518 mutex_lock(&nlm_host_mutex);
519 for_each_host(host, 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
568static void nlm_complain_hosts(struct net *net)
569{
570 struct hlist_head *chain;
571 struct nlm_host *host;
572
573 if (net) {
574 struct lockd_net *ln = net_generic(net, lockd_net_id);
575
576 if (ln->nrhosts == 0)
577 return;
578 printk(KERN_WARNING "lockd: couldn't shutdown host module for net %p!\n", net);
579 dprintk("lockd: %lu hosts left in net %p:\n", ln->nrhosts, net);
580 } else {
581 if (nrhosts == 0)
582 return;
583 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
584 dprintk("lockd: %lu hosts left:\n", nrhosts);
585 }
586
587 for_each_host(host, chain, nlm_server_hosts) {
588 if (net && host->net != net)
589 continue;
590 dprintk(" %s (cnt %d use %d exp %ld net %p)\n",
591 host->h_name, atomic_read(&host->h_count),
592 host->h_inuse, host->h_expires, host->net);
593 }
594}
595
596void
597nlm_shutdown_hosts_net(struct net *net)
598{
599 struct hlist_head *chain;
600 struct nlm_host *host;
601
602 mutex_lock(&nlm_host_mutex);
603
604 /* First, make all hosts eligible for gc */
605 dprintk("lockd: nuking all hosts in net %p...\n", net);
606 for_each_host(host, chain, nlm_server_hosts) {
607 if (net && host->net != net)
608 continue;
609 host->h_expires = jiffies - 1;
610 if (host->h_rpcclnt) {
611 rpc_shutdown_client(host->h_rpcclnt);
612 host->h_rpcclnt = NULL;
613 }
614 }
615
616 /* Then, perform a garbage collection pass */
617 nlm_gc_hosts(net);
618 mutex_unlock(&nlm_host_mutex);
619
620 nlm_complain_hosts(net);
621}
622
623/*
624 * Shut down the hosts module.
625 * Note that this routine is called only at server shutdown time.
626 */
627void
628nlm_shutdown_hosts(void)
629{
630 dprintk("lockd: shutting down host module\n");
631 nlm_shutdown_hosts_net(NULL);
632}
633
634/*
635 * Garbage collect any unused NLM hosts.
636 * This GC combines reference counting for async operations with
637 * mark & sweep for resources held by remote clients.
638 */
639static void
640nlm_gc_hosts(struct net *net)
641{
642 struct hlist_head *chain;
643 struct hlist_node *next;
644 struct nlm_host *host;
645
646 dprintk("lockd: host garbage collection for net %p\n", net);
647 for_each_host(host, chain, nlm_server_hosts) {
648 if (net && host->net != net)
649 continue;
650 host->h_inuse = 0;
651 }
652
653 /* Mark all hosts that hold locks, blocks or shares */
654 nlmsvc_mark_resources(net);
655
656 for_each_host_safe(host, next, chain, nlm_server_hosts) {
657 if (net && host->net != net)
658 continue;
659 if (atomic_read(&host->h_count) || host->h_inuse
660 || time_before(jiffies, host->h_expires)) {
661 dprintk("nlm_gc_hosts skipping %s "
662 "(cnt %d use %d exp %ld net %p)\n",
663 host->h_name, atomic_read(&host->h_count),
664 host->h_inuse, host->h_expires, host->net);
665 continue;
666 }
667 nlm_destroy_host_locked(host);
668 }
669
670 if (net) {
671 struct lockd_net *ln = net_generic(net, lockd_net_id);
672
673 ln->next_gc = jiffies + NLM_HOST_COLLECT;
674 }
675}