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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 nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
121 ni->hostname, ni->hostname_len);
122 if (unlikely(nsm == NULL)) {
123 dprintk("lockd: %s failed; no nsm handle\n",
124 __func__);
125 goto out;
126 }
127 }
128
129 host = kmalloc(sizeof(*host), GFP_KERNEL);
130 if (unlikely(host == NULL)) {
131 dprintk("lockd: %s failed; no memory\n", __func__);
132 nsm_release(nsm);
133 goto out;
134 }
135
136 memcpy(nlm_addr(host), ni->sap, ni->salen);
137 host->h_addrlen = ni->salen;
138 rpc_set_port(nlm_addr(host), 0);
139 host->h_srcaddrlen = 0;
140
141 host->h_rpcclnt = NULL;
142 host->h_name = nsm->sm_name;
143 host->h_version = ni->version;
144 host->h_proto = ni->protocol;
145 host->h_reclaiming = 0;
146 host->h_server = ni->server;
147 host->h_noresvport = ni->noresvport;
148 host->h_inuse = 0;
149 init_waitqueue_head(&host->h_gracewait);
150 init_rwsem(&host->h_rwsem);
151 host->h_state = 0;
152 host->h_nsmstate = 0;
153 host->h_pidcount = 0;
154 refcount_set(&host->h_count, 1);
155 mutex_init(&host->h_mutex);
156 host->h_nextrebind = now + NLM_HOST_REBIND;
157 host->h_expires = now + NLM_HOST_EXPIRE;
158 INIT_LIST_HEAD(&host->h_lockowners);
159 spin_lock_init(&host->h_lock);
160 INIT_LIST_HEAD(&host->h_granted);
161 INIT_LIST_HEAD(&host->h_reclaim);
162 host->h_nsmhandle = nsm;
163 host->h_addrbuf = nsm->sm_addrbuf;
164 host->net = ni->net;
165 host->h_cred = get_cred(ni->cred);
166 strscpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
167
168out:
169 return host;
170}
171
172/*
173 * Destroy an nlm_host and free associated resources
174 *
175 * Caller must hold nlm_host_mutex.
176 */
177static void nlm_destroy_host_locked(struct nlm_host *host)
178{
179 struct rpc_clnt *clnt;
180 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
181
182 dprintk("lockd: destroy host %s\n", host->h_name);
183
184 hlist_del_init(&host->h_hash);
185
186 nsm_unmonitor(host);
187 nsm_release(host->h_nsmhandle);
188
189 clnt = host->h_rpcclnt;
190 if (clnt != NULL)
191 rpc_shutdown_client(clnt);
192 put_cred(host->h_cred);
193 kfree(host);
194
195 ln->nrhosts--;
196 nrhosts--;
197}
198
199/**
200 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
201 * @sap: network address of server
202 * @salen: length of server address
203 * @protocol: transport protocol to use
204 * @version: NLM protocol version
205 * @hostname: '\0'-terminated hostname of server
206 * @noresvport: 1 if non-privileged port should be used
207 * @net: pointer to net namespace
208 * @cred: pointer to cred
209 *
210 * Returns an nlm_host structure that matches the passed-in
211 * [server address, transport protocol, NLM version, server hostname].
212 * If one doesn't already exist in the host cache, a new handle is
213 * created and returned.
214 */
215struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
216 const size_t salen,
217 const unsigned short protocol,
218 const u32 version,
219 const char *hostname,
220 int noresvport,
221 struct net *net,
222 const struct cred *cred)
223{
224 struct nlm_lookup_host_info ni = {
225 .server = 0,
226 .sap = sap,
227 .salen = salen,
228 .protocol = protocol,
229 .version = version,
230 .hostname = hostname,
231 .hostname_len = strlen(hostname),
232 .noresvport = noresvport,
233 .net = net,
234 .cred = cred,
235 };
236 struct hlist_head *chain;
237 struct nlm_host *host;
238 struct nsm_handle *nsm = NULL;
239 struct lockd_net *ln = net_generic(net, lockd_net_id);
240
241 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
242 (hostname ? hostname : "<none>"), version,
243 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
244
245 mutex_lock(&nlm_host_mutex);
246
247 chain = &nlm_client_hosts[nlm_hash_address(sap)];
248 hlist_for_each_entry(host, chain, h_hash) {
249 if (host->net != net)
250 continue;
251 if (!rpc_cmp_addr(nlm_addr(host), sap))
252 continue;
253
254 /* Same address. Share an NSM handle if we already have one */
255 if (nsm == NULL)
256 nsm = host->h_nsmhandle;
257
258 if (host->h_proto != protocol)
259 continue;
260 if (host->h_version != version)
261 continue;
262
263 nlm_get_host(host);
264 dprintk("lockd: %s found host %s (%s)\n", __func__,
265 host->h_name, host->h_addrbuf);
266 goto out;
267 }
268
269 host = nlm_alloc_host(&ni, nsm);
270 if (unlikely(host == NULL))
271 goto out;
272
273 hlist_add_head(&host->h_hash, chain);
274 ln->nrhosts++;
275 nrhosts++;
276
277 dprintk("lockd: %s created host %s (%s)\n", __func__,
278 host->h_name, host->h_addrbuf);
279
280out:
281 mutex_unlock(&nlm_host_mutex);
282 return host;
283}
284
285/**
286 * nlmclnt_release_host - release client nlm_host
287 * @host: nlm_host to release
288 *
289 */
290void nlmclnt_release_host(struct nlm_host *host)
291{
292 if (host == NULL)
293 return;
294
295 dprintk("lockd: release client host %s\n", host->h_name);
296
297 WARN_ON_ONCE(host->h_server);
298
299 if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
300 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
301 WARN_ON_ONCE(!list_empty(&host->h_granted));
302 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
303
304 nlm_destroy_host_locked(host);
305 mutex_unlock(&nlm_host_mutex);
306 }
307}
308
309/**
310 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
311 * @rqstp: incoming NLM request
312 * @hostname: name of client host
313 * @hostname_len: length of client hostname
314 *
315 * Returns an nlm_host structure that matches the [client address,
316 * transport protocol, NLM version, client hostname] of the passed-in
317 * NLM request. If one doesn't already exist in the host cache, a
318 * new handle is created and returned.
319 *
320 * Before possibly creating a new nlm_host, construct a sockaddr
321 * for a specific source address in case the local system has
322 * multiple network addresses. The family of the address in
323 * rq_daddr is guaranteed to be the same as the family of the
324 * address in rq_addr, so it's safe to use the same family for
325 * the source address.
326 */
327struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
328 const char *hostname,
329 const size_t hostname_len)
330{
331 struct hlist_head *chain;
332 struct nlm_host *host = NULL;
333 struct nsm_handle *nsm = NULL;
334 struct sockaddr *src_sap = svc_daddr(rqstp);
335 size_t src_len = rqstp->rq_daddrlen;
336 struct net *net = SVC_NET(rqstp);
337 struct nlm_lookup_host_info ni = {
338 .server = 1,
339 .sap = svc_addr(rqstp),
340 .salen = rqstp->rq_addrlen,
341 .protocol = rqstp->rq_prot,
342 .version = rqstp->rq_vers,
343 .hostname = hostname,
344 .hostname_len = hostname_len,
345 .net = net,
346 };
347 struct lockd_net *ln = net_generic(net, lockd_net_id);
348
349 dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
350 (int)hostname_len, hostname, rqstp->rq_vers,
351 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
352
353 mutex_lock(&nlm_host_mutex);
354
355 if (time_after_eq(jiffies, ln->next_gc))
356 nlm_gc_hosts(net);
357
358 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
359 hlist_for_each_entry(host, chain, h_hash) {
360 if (host->net != net)
361 continue;
362 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
363 continue;
364
365 /* Same address. Share an NSM handle if we already have one */
366 if (nsm == NULL)
367 nsm = host->h_nsmhandle;
368
369 if (host->h_proto != ni.protocol)
370 continue;
371 if (host->h_version != ni.version)
372 continue;
373 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
374 continue;
375
376 /* Move to head of hash chain. */
377 hlist_del(&host->h_hash);
378 hlist_add_head(&host->h_hash, chain);
379
380 nlm_get_host(host);
381 dprintk("lockd: %s found host %s (%s)\n",
382 __func__, host->h_name, host->h_addrbuf);
383 goto out;
384 }
385
386 host = nlm_alloc_host(&ni, nsm);
387 if (unlikely(host == NULL))
388 goto out;
389
390 memcpy(nlm_srcaddr(host), src_sap, src_len);
391 host->h_srcaddrlen = src_len;
392 hlist_add_head(&host->h_hash, chain);
393 ln->nrhosts++;
394 nrhosts++;
395
396 refcount_inc(&host->h_count);
397
398 dprintk("lockd: %s created host %s (%s)\n",
399 __func__, host->h_name, host->h_addrbuf);
400
401out:
402 mutex_unlock(&nlm_host_mutex);
403 return host;
404}
405
406/**
407 * nlmsvc_release_host - release server nlm_host
408 * @host: nlm_host to release
409 *
410 * Host is destroyed later in nlm_gc_host().
411 */
412void nlmsvc_release_host(struct nlm_host *host)
413{
414 if (host == NULL)
415 return;
416
417 dprintk("lockd: release server host %s\n", host->h_name);
418
419 WARN_ON_ONCE(!host->h_server);
420 refcount_dec(&host->h_count);
421}
422
423/*
424 * Create the NLM RPC client for an NLM peer
425 */
426struct rpc_clnt *
427nlm_bind_host(struct nlm_host *host)
428{
429 struct rpc_clnt *clnt;
430
431 dprintk("lockd: nlm_bind_host %s (%s)\n",
432 host->h_name, host->h_addrbuf);
433
434 /* Lock host handle */
435 mutex_lock(&host->h_mutex);
436
437 /* If we've already created an RPC client, check whether
438 * RPC rebind is required
439 */
440 if ((clnt = host->h_rpcclnt) != NULL) {
441 nlm_rebind_host(host);
442 } else {
443 unsigned long increment = nlm_timeout * HZ;
444 struct rpc_timeout timeparms = {
445 .to_initval = increment,
446 .to_increment = increment,
447 .to_maxval = increment * 6UL,
448 .to_retries = 5U,
449 };
450 struct rpc_create_args args = {
451 .net = host->net,
452 .protocol = host->h_proto,
453 .address = nlm_addr(host),
454 .addrsize = host->h_addrlen,
455 .timeout = &timeparms,
456 .servername = host->h_name,
457 .program = &nlm_program,
458 .version = host->h_version,
459 .authflavor = RPC_AUTH_UNIX,
460 .flags = (RPC_CLNT_CREATE_NOPING |
461 RPC_CLNT_CREATE_AUTOBIND |
462 RPC_CLNT_CREATE_REUSEPORT),
463 .cred = host->h_cred,
464 };
465
466 /*
467 * lockd retries server side blocks automatically so we want
468 * those to be soft RPC calls. Client side calls need to be
469 * hard RPC tasks.
470 */
471 if (!host->h_server)
472 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
473 if (host->h_noresvport)
474 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
475 if (host->h_srcaddrlen)
476 args.saddress = nlm_srcaddr(host);
477
478 clnt = rpc_create(&args);
479 if (!IS_ERR(clnt))
480 host->h_rpcclnt = clnt;
481 else {
482 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
483 clnt = NULL;
484 }
485 }
486
487 mutex_unlock(&host->h_mutex);
488 return clnt;
489}
490
491/**
492 * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port
493 * @host: NLM host handle for peer
494 *
495 * This is not needed when using a connection-oriented protocol, such as TCP.
496 * The existing autobind mechanism is sufficient to force a rebind when
497 * required, e.g. on connection state transitions.
498 */
499void
500nlm_rebind_host(struct nlm_host *host)
501{
502 if (host->h_proto != IPPROTO_UDP)
503 return;
504
505 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
506 rpc_force_rebind(host->h_rpcclnt);
507 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
508 }
509}
510
511/*
512 * Increment NLM host count
513 */
514struct nlm_host * nlm_get_host(struct nlm_host *host)
515{
516 if (host) {
517 dprintk("lockd: get host %s\n", host->h_name);
518 refcount_inc(&host->h_count);
519 host->h_expires = jiffies + NLM_HOST_EXPIRE;
520 }
521 return host;
522}
523
524static struct nlm_host *next_host_state(struct hlist_head *cache,
525 struct nsm_handle *nsm,
526 const struct nlm_reboot *info)
527{
528 struct nlm_host *host;
529 struct hlist_head *chain;
530
531 mutex_lock(&nlm_host_mutex);
532 for_each_host(host, chain, cache) {
533 if (host->h_nsmhandle == nsm
534 && host->h_nsmstate != info->state) {
535 host->h_nsmstate = info->state;
536 host->h_state++;
537
538 nlm_get_host(host);
539 mutex_unlock(&nlm_host_mutex);
540 return host;
541 }
542 }
543
544 mutex_unlock(&nlm_host_mutex);
545 return NULL;
546}
547
548/**
549 * nlm_host_rebooted - Release all resources held by rebooted host
550 * @net: network namespace
551 * @info: pointer to decoded results of NLM_SM_NOTIFY call
552 *
553 * We were notified that the specified host has rebooted. Release
554 * all resources held by that peer.
555 */
556void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info)
557{
558 struct nsm_handle *nsm;
559 struct nlm_host *host;
560
561 nsm = nsm_reboot_lookup(net, info);
562 if (unlikely(nsm == NULL))
563 return;
564
565 /* Mark all hosts tied to this NSM state as having rebooted.
566 * We run the loop repeatedly, because we drop the host table
567 * lock for this.
568 * To avoid processing a host several times, we match the nsmstate.
569 */
570 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
571 nlmsvc_free_host_resources(host);
572 nlmsvc_release_host(host);
573 }
574 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
575 nlmclnt_recovery(host);
576 nlmclnt_release_host(host);
577 }
578
579 nsm_release(nsm);
580}
581
582static void nlm_complain_hosts(struct net *net)
583{
584 struct hlist_head *chain;
585 struct nlm_host *host;
586
587 if (net) {
588 struct lockd_net *ln = net_generic(net, lockd_net_id);
589
590 if (ln->nrhosts == 0)
591 return;
592 pr_warn("lockd: couldn't shutdown host module for net %x!\n",
593 net->ns.inum);
594 dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
595 net->ns.inum);
596 } else {
597 if (nrhosts == 0)
598 return;
599 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
600 dprintk("lockd: %lu hosts left:\n", nrhosts);
601 }
602
603 for_each_host(host, chain, nlm_server_hosts) {
604 if (net && host->net != net)
605 continue;
606 dprintk(" %s (cnt %d use %d exp %ld net %x)\n",
607 host->h_name, refcount_read(&host->h_count),
608 host->h_inuse, host->h_expires, host->net->ns.inum);
609 }
610}
611
612void
613nlm_shutdown_hosts_net(struct net *net)
614{
615 struct hlist_head *chain;
616 struct nlm_host *host;
617
618 mutex_lock(&nlm_host_mutex);
619
620 /* First, make all hosts eligible for gc */
621 dprintk("lockd: nuking all hosts in net %x...\n",
622 net ? net->ns.inum : 0);
623 for_each_host(host, chain, nlm_server_hosts) {
624 if (net && host->net != net)
625 continue;
626 host->h_expires = jiffies - 1;
627 if (host->h_rpcclnt) {
628 rpc_shutdown_client(host->h_rpcclnt);
629 host->h_rpcclnt = NULL;
630 }
631 nlmsvc_free_host_resources(host);
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->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}