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