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