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1/*
2 * linux/fs/lockd/host.c
3 *
4 * Management for NLM peer hosts. The nlm_host struct is shared
5 * between client and server implementation. The only reason to
6 * do so is to reduce code bloat.
7 *
8 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
9 */
10
11#include <linux/types.h>
12#include <linux/slab.h>
13#include <linux/in.h>
14#include <linux/in6.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/svc.h>
17#include <linux/lockd/lockd.h>
18#include <linux/mutex.h>
19
20#include <net/ipv6.h>
21
22#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
23#define NLM_HOST_NRHASH 32
24#define NLM_HOST_REBIND (60 * HZ)
25#define NLM_HOST_EXPIRE (300 * HZ)
26#define NLM_HOST_COLLECT (120 * HZ)
27
28static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
29static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
30
31#define for_each_host(host, pos, chain, table) \
32 for ((chain) = (table); \
33 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
34 hlist_for_each_entry((host), (pos), (chain), h_hash)
35
36#define for_each_host_safe(host, pos, next, chain, table) \
37 for ((chain) = (table); \
38 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
39 hlist_for_each_entry_safe((host), (pos), (next), \
40 (chain), h_hash)
41
42static unsigned long next_gc;
43static unsigned long nrhosts;
44static DEFINE_MUTEX(nlm_host_mutex);
45
46static void nlm_gc_hosts(void);
47
48struct nlm_lookup_host_info {
49 const int server; /* search for server|client */
50 const struct sockaddr *sap; /* address to search for */
51 const size_t salen; /* it's length */
52 const unsigned short protocol; /* transport to search for*/
53 const u32 version; /* NLM version to search for */
54 const char *hostname; /* remote's hostname */
55 const size_t hostname_len; /* it's length */
56 const int noresvport; /* use non-priv port */
57};
58
59/*
60 * Hash function must work well on big- and little-endian platforms
61 */
62static unsigned int __nlm_hash32(const __be32 n)
63{
64 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
65 return hash ^ (hash >> 8);
66}
67
68static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
69{
70 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
71 return __nlm_hash32(sin->sin_addr.s_addr);
72}
73
74static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
75{
76 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
77 const struct in6_addr addr = sin6->sin6_addr;
78 return __nlm_hash32(addr.s6_addr32[0]) ^
79 __nlm_hash32(addr.s6_addr32[1]) ^
80 __nlm_hash32(addr.s6_addr32[2]) ^
81 __nlm_hash32(addr.s6_addr32[3]);
82}
83
84static unsigned int nlm_hash_address(const struct sockaddr *sap)
85{
86 unsigned int hash;
87
88 switch (sap->sa_family) {
89 case AF_INET:
90 hash = __nlm_hash_addr4(sap);
91 break;
92 case AF_INET6:
93 hash = __nlm_hash_addr6(sap);
94 break;
95 default:
96 hash = 0;
97 }
98 return hash & (NLM_HOST_NRHASH - 1);
99}
100
101/*
102 * Allocate and initialize an nlm_host. Common to both client and server.
103 */
104static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
105 struct nsm_handle *nsm)
106{
107 struct nlm_host *host = NULL;
108 unsigned long now = jiffies;
109
110 if (nsm != NULL)
111 atomic_inc(&nsm->sm_count);
112 else {
113 host = NULL;
114 nsm = nsm_get_handle(ni->sap, ni->salen,
115 ni->hostname, ni->hostname_len);
116 if (unlikely(nsm == NULL)) {
117 dprintk("lockd: %s failed; no nsm handle\n",
118 __func__);
119 goto out;
120 }
121 }
122
123 host = kmalloc(sizeof(*host), GFP_KERNEL);
124 if (unlikely(host == NULL)) {
125 dprintk("lockd: %s failed; no memory\n", __func__);
126 nsm_release(nsm);
127 goto out;
128 }
129
130 memcpy(nlm_addr(host), ni->sap, ni->salen);
131 host->h_addrlen = ni->salen;
132 rpc_set_port(nlm_addr(host), 0);
133 host->h_srcaddrlen = 0;
134
135 host->h_rpcclnt = NULL;
136 host->h_name = nsm->sm_name;
137 host->h_version = ni->version;
138 host->h_proto = ni->protocol;
139 host->h_reclaiming = 0;
140 host->h_server = ni->server;
141 host->h_noresvport = ni->noresvport;
142 host->h_inuse = 0;
143 init_waitqueue_head(&host->h_gracewait);
144 init_rwsem(&host->h_rwsem);
145 host->h_state = 0;
146 host->h_nsmstate = 0;
147 host->h_pidcount = 0;
148 atomic_set(&host->h_count, 1);
149 mutex_init(&host->h_mutex);
150 host->h_nextrebind = now + NLM_HOST_REBIND;
151 host->h_expires = now + NLM_HOST_EXPIRE;
152 INIT_LIST_HEAD(&host->h_lockowners);
153 spin_lock_init(&host->h_lock);
154 INIT_LIST_HEAD(&host->h_granted);
155 INIT_LIST_HEAD(&host->h_reclaim);
156 host->h_nsmhandle = nsm;
157 host->h_addrbuf = nsm->sm_addrbuf;
158
159out:
160 return host;
161}
162
163/*
164 * Destroy an nlm_host and free associated resources
165 *
166 * Caller must hold nlm_host_mutex.
167 */
168static void nlm_destroy_host_locked(struct nlm_host *host)
169{
170 struct rpc_clnt *clnt;
171
172 dprintk("lockd: destroy host %s\n", host->h_name);
173
174 BUG_ON(!list_empty(&host->h_lockowners));
175 BUG_ON(atomic_read(&host->h_count));
176
177 hlist_del_init(&host->h_hash);
178
179 nsm_unmonitor(host);
180 nsm_release(host->h_nsmhandle);
181
182 clnt = host->h_rpcclnt;
183 if (clnt != NULL)
184 rpc_shutdown_client(clnt);
185 kfree(host);
186
187 nrhosts--;
188}
189
190/**
191 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
192 * @sap: network address of server
193 * @salen: length of server address
194 * @protocol: transport protocol to use
195 * @version: NLM protocol version
196 * @hostname: '\0'-terminated hostname of server
197 * @noresvport: 1 if non-privileged port should be used
198 *
199 * Returns an nlm_host structure that matches the passed-in
200 * [server address, transport protocol, NLM version, server hostname].
201 * If one doesn't already exist in the host cache, a new handle is
202 * created and returned.
203 */
204struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
205 const size_t salen,
206 const unsigned short protocol,
207 const u32 version,
208 const char *hostname,
209 int noresvport)
210{
211 struct nlm_lookup_host_info ni = {
212 .server = 0,
213 .sap = sap,
214 .salen = salen,
215 .protocol = protocol,
216 .version = version,
217 .hostname = hostname,
218 .hostname_len = strlen(hostname),
219 .noresvport = noresvport,
220 };
221 struct hlist_head *chain;
222 struct hlist_node *pos;
223 struct nlm_host *host;
224 struct nsm_handle *nsm = NULL;
225
226 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
227 (hostname ? hostname : "<none>"), version,
228 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
229
230 mutex_lock(&nlm_host_mutex);
231
232 chain = &nlm_client_hosts[nlm_hash_address(sap)];
233 hlist_for_each_entry(host, pos, chain, h_hash) {
234 if (!rpc_cmp_addr(nlm_addr(host), sap))
235 continue;
236
237 /* Same address. Share an NSM handle if we already have one */
238 if (nsm == NULL)
239 nsm = host->h_nsmhandle;
240
241 if (host->h_proto != protocol)
242 continue;
243 if (host->h_version != version)
244 continue;
245
246 nlm_get_host(host);
247 dprintk("lockd: %s found host %s (%s)\n", __func__,
248 host->h_name, host->h_addrbuf);
249 goto out;
250 }
251
252 host = nlm_alloc_host(&ni, nsm);
253 if (unlikely(host == NULL))
254 goto out;
255
256 hlist_add_head(&host->h_hash, chain);
257 nrhosts++;
258
259 dprintk("lockd: %s created host %s (%s)\n", __func__,
260 host->h_name, host->h_addrbuf);
261
262out:
263 mutex_unlock(&nlm_host_mutex);
264 return host;
265}
266
267/**
268 * nlmclnt_release_host - release client nlm_host
269 * @host: nlm_host to release
270 *
271 */
272void nlmclnt_release_host(struct nlm_host *host)
273{
274 if (host == NULL)
275 return;
276
277 dprintk("lockd: release client host %s\n", host->h_name);
278
279 BUG_ON(atomic_read(&host->h_count) < 0);
280 BUG_ON(host->h_server);
281
282 if (atomic_dec_and_test(&host->h_count)) {
283 BUG_ON(!list_empty(&host->h_lockowners));
284 BUG_ON(!list_empty(&host->h_granted));
285 BUG_ON(!list_empty(&host->h_reclaim));
286
287 mutex_lock(&nlm_host_mutex);
288 nlm_destroy_host_locked(host);
289 mutex_unlock(&nlm_host_mutex);
290 }
291}
292
293/**
294 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
295 * @rqstp: incoming NLM request
296 * @hostname: name of client host
297 * @hostname_len: length of client hostname
298 *
299 * Returns an nlm_host structure that matches the [client address,
300 * transport protocol, NLM version, client hostname] of the passed-in
301 * NLM request. If one doesn't already exist in the host cache, a
302 * new handle is created and returned.
303 *
304 * Before possibly creating a new nlm_host, construct a sockaddr
305 * for a specific source address in case the local system has
306 * multiple network addresses. The family of the address in
307 * rq_daddr is guaranteed to be the same as the family of the
308 * address in rq_addr, so it's safe to use the same family for
309 * the source address.
310 */
311struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
312 const char *hostname,
313 const size_t hostname_len)
314{
315 struct hlist_head *chain;
316 struct hlist_node *pos;
317 struct nlm_host *host = NULL;
318 struct nsm_handle *nsm = NULL;
319 struct sockaddr_in sin = {
320 .sin_family = AF_INET,
321 };
322 struct sockaddr_in6 sin6 = {
323 .sin6_family = AF_INET6,
324 };
325 struct sockaddr *src_sap;
326 size_t src_len = rqstp->rq_addrlen;
327 struct nlm_lookup_host_info ni = {
328 .server = 1,
329 .sap = svc_addr(rqstp),
330 .salen = rqstp->rq_addrlen,
331 .protocol = rqstp->rq_prot,
332 .version = rqstp->rq_vers,
333 .hostname = hostname,
334 .hostname_len = hostname_len,
335 };
336
337 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
338 (int)hostname_len, hostname, rqstp->rq_vers,
339 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
340
341 mutex_lock(&nlm_host_mutex);
342
343 switch (ni.sap->sa_family) {
344 case AF_INET:
345 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
346 src_sap = (struct sockaddr *)&sin;
347 break;
348 case AF_INET6:
349 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
350 src_sap = (struct sockaddr *)&sin6;
351 break;
352 default:
353 dprintk("lockd: %s failed; unrecognized address family\n",
354 __func__);
355 goto out;
356 }
357
358 if (time_after_eq(jiffies, next_gc))
359 nlm_gc_hosts();
360
361 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
362 hlist_for_each_entry(host, pos, chain, h_hash) {
363 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
364 continue;
365
366 /* Same address. Share an NSM handle if we already have one */
367 if (nsm == NULL)
368 nsm = host->h_nsmhandle;
369
370 if (host->h_proto != ni.protocol)
371 continue;
372 if (host->h_version != ni.version)
373 continue;
374 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
375 continue;
376
377 /* Move to head of hash chain. */
378 hlist_del(&host->h_hash);
379 hlist_add_head(&host->h_hash, chain);
380
381 nlm_get_host(host);
382 dprintk("lockd: %s found host %s (%s)\n",
383 __func__, host->h_name, host->h_addrbuf);
384 goto out;
385 }
386
387 host = nlm_alloc_host(&ni, nsm);
388 if (unlikely(host == NULL))
389 goto out;
390
391 memcpy(nlm_srcaddr(host), src_sap, src_len);
392 host->h_srcaddrlen = src_len;
393 hlist_add_head(&host->h_hash, chain);
394 nrhosts++;
395
396 dprintk("lockd: %s created host %s (%s)\n",
397 __func__, host->h_name, host->h_addrbuf);
398
399out:
400 mutex_unlock(&nlm_host_mutex);
401 return host;
402}
403
404/**
405 * nlmsvc_release_host - release server nlm_host
406 * @host: nlm_host to release
407 *
408 * Host is destroyed later in nlm_gc_host().
409 */
410void nlmsvc_release_host(struct nlm_host *host)
411{
412 if (host == NULL)
413 return;
414
415 dprintk("lockd: release server host %s\n", host->h_name);
416
417 BUG_ON(atomic_read(&host->h_count) < 0);
418 BUG_ON(!host->h_server);
419 atomic_dec(&host->h_count);
420}
421
422/*
423 * Create the NLM RPC client for an NLM peer
424 */
425struct rpc_clnt *
426nlm_bind_host(struct nlm_host *host)
427{
428 struct rpc_clnt *clnt;
429
430 dprintk("lockd: nlm_bind_host %s (%s)\n",
431 host->h_name, host->h_addrbuf);
432
433 /* Lock host handle */
434 mutex_lock(&host->h_mutex);
435
436 /* If we've already created an RPC client, check whether
437 * RPC rebind is required
438 */
439 if ((clnt = host->h_rpcclnt) != NULL) {
440 if (time_after_eq(jiffies, host->h_nextrebind)) {
441 rpc_force_rebind(clnt);
442 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
443 dprintk("lockd: next rebind in %lu jiffies\n",
444 host->h_nextrebind - jiffies);
445 }
446 } else {
447 unsigned long increment = nlmsvc_timeout;
448 struct rpc_timeout timeparms = {
449 .to_initval = increment,
450 .to_increment = increment,
451 .to_maxval = increment * 6UL,
452 .to_retries = 5U,
453 };
454 struct rpc_create_args args = {
455 .net = &init_net,
456 .protocol = host->h_proto,
457 .address = nlm_addr(host),
458 .addrsize = host->h_addrlen,
459 .timeout = &timeparms,
460 .servername = host->h_name,
461 .program = &nlm_program,
462 .version = host->h_version,
463 .authflavor = RPC_AUTH_UNIX,
464 .flags = (RPC_CLNT_CREATE_NOPING |
465 RPC_CLNT_CREATE_AUTOBIND),
466 };
467
468 /*
469 * lockd retries server side blocks automatically so we want
470 * those to be soft RPC calls. Client side calls need to be
471 * hard RPC tasks.
472 */
473 if (!host->h_server)
474 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
475 if (host->h_noresvport)
476 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
477 if (host->h_srcaddrlen)
478 args.saddress = nlm_srcaddr(host);
479
480 clnt = rpc_create(&args);
481 if (!IS_ERR(clnt))
482 host->h_rpcclnt = clnt;
483 else {
484 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
485 clnt = NULL;
486 }
487 }
488
489 mutex_unlock(&host->h_mutex);
490 return clnt;
491}
492
493/*
494 * Force a portmap lookup of the remote lockd port
495 */
496void
497nlm_rebind_host(struct nlm_host *host)
498{
499 dprintk("lockd: rebind host %s\n", host->h_name);
500 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
501 rpc_force_rebind(host->h_rpcclnt);
502 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
503 }
504}
505
506/*
507 * Increment NLM host count
508 */
509struct nlm_host * nlm_get_host(struct nlm_host *host)
510{
511 if (host) {
512 dprintk("lockd: get host %s\n", host->h_name);
513 atomic_inc(&host->h_count);
514 host->h_expires = jiffies + NLM_HOST_EXPIRE;
515 }
516 return host;
517}
518
519static struct nlm_host *next_host_state(struct hlist_head *cache,
520 struct nsm_handle *nsm,
521 const struct nlm_reboot *info)
522{
523 struct nlm_host *host;
524 struct hlist_head *chain;
525 struct hlist_node *pos;
526
527 mutex_lock(&nlm_host_mutex);
528 for_each_host(host, pos, chain, cache) {
529 if (host->h_nsmhandle == nsm
530 && host->h_nsmstate != info->state) {
531 host->h_nsmstate = info->state;
532 host->h_state++;
533
534 nlm_get_host(host);
535 mutex_unlock(&nlm_host_mutex);
536 return host;
537 }
538 }
539
540 mutex_unlock(&nlm_host_mutex);
541 return NULL;
542}
543
544/**
545 * nlm_host_rebooted - Release all resources held by rebooted host
546 * @info: pointer to decoded results of NLM_SM_NOTIFY call
547 *
548 * We were notified that the specified host has rebooted. Release
549 * all resources held by that peer.
550 */
551void nlm_host_rebooted(const struct nlm_reboot *info)
552{
553 struct nsm_handle *nsm;
554 struct nlm_host *host;
555
556 nsm = nsm_reboot_lookup(info);
557 if (unlikely(nsm == NULL))
558 return;
559
560 /* Mark all hosts tied to this NSM state as having rebooted.
561 * We run the loop repeatedly, because we drop the host table
562 * lock for this.
563 * To avoid processing a host several times, we match the nsmstate.
564 */
565 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
566 nlmsvc_free_host_resources(host);
567 nlmsvc_release_host(host);
568 }
569 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
570 nlmclnt_recovery(host);
571 nlmclnt_release_host(host);
572 }
573
574 nsm_release(nsm);
575}
576
577/*
578 * Shut down the hosts module.
579 * Note that this routine is called only at server shutdown time.
580 */
581void
582nlm_shutdown_hosts(void)
583{
584 struct hlist_head *chain;
585 struct hlist_node *pos;
586 struct nlm_host *host;
587
588 dprintk("lockd: shutting down host module\n");
589 mutex_lock(&nlm_host_mutex);
590
591 /* First, make all hosts eligible for gc */
592 dprintk("lockd: nuking all hosts...\n");
593 for_each_host(host, pos, chain, nlm_server_hosts) {
594 host->h_expires = jiffies - 1;
595 if (host->h_rpcclnt) {
596 rpc_shutdown_client(host->h_rpcclnt);
597 host->h_rpcclnt = NULL;
598 }
599 }
600
601 /* Then, perform a garbage collection pass */
602 nlm_gc_hosts();
603 mutex_unlock(&nlm_host_mutex);
604
605 /* complain if any hosts are left */
606 if (nrhosts != 0) {
607 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
608 dprintk("lockd: %lu hosts left:\n", nrhosts);
609 for_each_host(host, pos, chain, nlm_server_hosts) {
610 dprintk(" %s (cnt %d use %d exp %ld)\n",
611 host->h_name, atomic_read(&host->h_count),
612 host->h_inuse, host->h_expires);
613 }
614 }
615}
616
617/*
618 * Garbage collect any unused NLM hosts.
619 * This GC combines reference counting for async operations with
620 * mark & sweep for resources held by remote clients.
621 */
622static void
623nlm_gc_hosts(void)
624{
625 struct hlist_head *chain;
626 struct hlist_node *pos, *next;
627 struct nlm_host *host;
628
629 dprintk("lockd: host garbage collection\n");
630 for_each_host(host, pos, chain, nlm_server_hosts)
631 host->h_inuse = 0;
632
633 /* Mark all hosts that hold locks, blocks or shares */
634 nlmsvc_mark_resources();
635
636 for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
637 if (atomic_read(&host->h_count) || host->h_inuse
638 || time_before(jiffies, host->h_expires)) {
639 dprintk("nlm_gc_hosts skipping %s "
640 "(cnt %d use %d exp %ld)\n",
641 host->h_name, atomic_read(&host->h_count),
642 host->h_inuse, host->h_expires);
643 continue;
644 }
645 nlm_destroy_host_locked(host);
646 }
647
648 next_gc = jiffies + NLM_HOST_COLLECT;
649}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/host.c
4 *
5 * Management for NLM peer hosts. The nlm_host struct is shared
6 * between client and server implementation. The only reason to
7 * do so is to reduce code bloat.
8 *
9 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
10 */
11
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/in.h>
15#include <linux/in6.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/addr.h>
18#include <linux/sunrpc/svc.h>
19#include <linux/lockd/lockd.h>
20#include <linux/mutex.h>
21
22#include <linux/sunrpc/svc_xprt.h>
23
24#include <net/ipv6.h>
25
26#include "netns.h"
27
28#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
29#define NLM_HOST_NRHASH 32
30#define NLM_HOST_REBIND (60 * HZ)
31#define NLM_HOST_EXPIRE (300 * HZ)
32#define NLM_HOST_COLLECT (120 * HZ)
33
34static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
35static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
36
37#define for_each_host(host, chain, table) \
38 for ((chain) = (table); \
39 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
40 hlist_for_each_entry((host), (chain), h_hash)
41
42#define for_each_host_safe(host, next, chain, table) \
43 for ((chain) = (table); \
44 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
45 hlist_for_each_entry_safe((host), (next), \
46 (chain), h_hash)
47
48static unsigned long nrhosts;
49static DEFINE_MUTEX(nlm_host_mutex);
50
51static void nlm_gc_hosts(struct net *net);
52
53struct nlm_lookup_host_info {
54 const int server; /* search for server|client */
55 const struct sockaddr *sap; /* address to search for */
56 const size_t salen; /* it's length */
57 const unsigned short protocol; /* transport to search for*/
58 const u32 version; /* NLM version to search for */
59 const char *hostname; /* remote's hostname */
60 const size_t hostname_len; /* it's length */
61 const int noresvport; /* use non-priv port */
62 struct net *net; /* network namespace to bind */
63 const struct cred *cred;
64};
65
66/*
67 * Hash function must work well on big- and little-endian platforms
68 */
69static unsigned int __nlm_hash32(const __be32 n)
70{
71 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
72 return hash ^ (hash >> 8);
73}
74
75static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
76{
77 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
78 return __nlm_hash32(sin->sin_addr.s_addr);
79}
80
81static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
82{
83 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
84 const struct in6_addr addr = sin6->sin6_addr;
85 return __nlm_hash32(addr.s6_addr32[0]) ^
86 __nlm_hash32(addr.s6_addr32[1]) ^
87 __nlm_hash32(addr.s6_addr32[2]) ^
88 __nlm_hash32(addr.s6_addr32[3]);
89}
90
91static unsigned int nlm_hash_address(const struct sockaddr *sap)
92{
93 unsigned int hash;
94
95 switch (sap->sa_family) {
96 case AF_INET:
97 hash = __nlm_hash_addr4(sap);
98 break;
99 case AF_INET6:
100 hash = __nlm_hash_addr6(sap);
101 break;
102 default:
103 hash = 0;
104 }
105 return hash & (NLM_HOST_NRHASH - 1);
106}
107
108/*
109 * Allocate and initialize an nlm_host. Common to both client and server.
110 */
111static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
112 struct nsm_handle *nsm)
113{
114 struct nlm_host *host = NULL;
115 unsigned long now = jiffies;
116
117 if (nsm != NULL)
118 refcount_inc(&nsm->sm_count);
119 else {
120 host = NULL;
121 nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
122 ni->hostname, ni->hostname_len);
123 if (unlikely(nsm == NULL)) {
124 dprintk("lockd: %s failed; no nsm handle\n",
125 __func__);
126 goto out;
127 }
128 }
129
130 host = kmalloc(sizeof(*host), GFP_KERNEL);
131 if (unlikely(host == NULL)) {
132 dprintk("lockd: %s failed; no memory\n", __func__);
133 nsm_release(nsm);
134 goto out;
135 }
136
137 memcpy(nlm_addr(host), ni->sap, ni->salen);
138 host->h_addrlen = ni->salen;
139 rpc_set_port(nlm_addr(host), 0);
140 host->h_srcaddrlen = 0;
141
142 host->h_rpcclnt = NULL;
143 host->h_name = nsm->sm_name;
144 host->h_version = ni->version;
145 host->h_proto = ni->protocol;
146 host->h_reclaiming = 0;
147 host->h_server = ni->server;
148 host->h_noresvport = ni->noresvport;
149 host->h_inuse = 0;
150 init_waitqueue_head(&host->h_gracewait);
151 init_rwsem(&host->h_rwsem);
152 host->h_state = 0;
153 host->h_nsmstate = 0;
154 host->h_pidcount = 0;
155 refcount_set(&host->h_count, 1);
156 mutex_init(&host->h_mutex);
157 host->h_nextrebind = now + NLM_HOST_REBIND;
158 host->h_expires = now + NLM_HOST_EXPIRE;
159 INIT_LIST_HEAD(&host->h_lockowners);
160 spin_lock_init(&host->h_lock);
161 INIT_LIST_HEAD(&host->h_granted);
162 INIT_LIST_HEAD(&host->h_reclaim);
163 host->h_nsmhandle = nsm;
164 host->h_addrbuf = nsm->sm_addrbuf;
165 host->net = ni->net;
166 host->h_cred = get_cred(ni->cred);
167 strscpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
168
169out:
170 return host;
171}
172
173/*
174 * Destroy an nlm_host and free associated resources
175 *
176 * Caller must hold nlm_host_mutex.
177 */
178static void nlm_destroy_host_locked(struct nlm_host *host)
179{
180 struct rpc_clnt *clnt;
181 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
182
183 dprintk("lockd: destroy host %s\n", host->h_name);
184
185 hlist_del_init(&host->h_hash);
186
187 nsm_unmonitor(host);
188 nsm_release(host->h_nsmhandle);
189
190 clnt = host->h_rpcclnt;
191 if (clnt != NULL)
192 rpc_shutdown_client(clnt);
193 put_cred(host->h_cred);
194 kfree(host);
195
196 ln->nrhosts--;
197 nrhosts--;
198}
199
200/**
201 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
202 * @sap: network address of server
203 * @salen: length of server address
204 * @protocol: transport protocol to use
205 * @version: NLM protocol version
206 * @hostname: '\0'-terminated hostname of server
207 * @noresvport: 1 if non-privileged port should be used
208 * @net: pointer to net namespace
209 * @cred: pointer to cred
210 *
211 * Returns an nlm_host structure that matches the passed-in
212 * [server address, transport protocol, NLM version, server hostname].
213 * If one doesn't already exist in the host cache, a new handle is
214 * created and returned.
215 */
216struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
217 const size_t salen,
218 const unsigned short protocol,
219 const u32 version,
220 const char *hostname,
221 int noresvport,
222 struct net *net,
223 const struct cred *cred)
224{
225 struct nlm_lookup_host_info ni = {
226 .server = 0,
227 .sap = sap,
228 .salen = salen,
229 .protocol = protocol,
230 .version = version,
231 .hostname = hostname,
232 .hostname_len = strlen(hostname),
233 .noresvport = noresvport,
234 .net = net,
235 .cred = cred,
236 };
237 struct hlist_head *chain;
238 struct nlm_host *host;
239 struct nsm_handle *nsm = NULL;
240 struct lockd_net *ln = net_generic(net, lockd_net_id);
241
242 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
243 (hostname ? hostname : "<none>"), version,
244 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
245
246 mutex_lock(&nlm_host_mutex);
247
248 chain = &nlm_client_hosts[nlm_hash_address(sap)];
249 hlist_for_each_entry(host, chain, h_hash) {
250 if (host->net != net)
251 continue;
252 if (!rpc_cmp_addr(nlm_addr(host), sap))
253 continue;
254
255 /* Same address. Share an NSM handle if we already have one */
256 if (nsm == NULL)
257 nsm = host->h_nsmhandle;
258
259 if (host->h_proto != protocol)
260 continue;
261 if (host->h_version != version)
262 continue;
263
264 nlm_get_host(host);
265 dprintk("lockd: %s found host %s (%s)\n", __func__,
266 host->h_name, host->h_addrbuf);
267 goto out;
268 }
269
270 host = nlm_alloc_host(&ni, nsm);
271 if (unlikely(host == NULL))
272 goto out;
273
274 hlist_add_head(&host->h_hash, chain);
275 ln->nrhosts++;
276 nrhosts++;
277
278 dprintk("lockd: %s created host %s (%s)\n", __func__,
279 host->h_name, host->h_addrbuf);
280
281out:
282 mutex_unlock(&nlm_host_mutex);
283 return host;
284}
285
286/**
287 * nlmclnt_release_host - release client nlm_host
288 * @host: nlm_host to release
289 *
290 */
291void nlmclnt_release_host(struct nlm_host *host)
292{
293 if (host == NULL)
294 return;
295
296 dprintk("lockd: release client host %s\n", host->h_name);
297
298 WARN_ON_ONCE(host->h_server);
299
300 if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
301 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
302 WARN_ON_ONCE(!list_empty(&host->h_granted));
303 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
304
305 nlm_destroy_host_locked(host);
306 mutex_unlock(&nlm_host_mutex);
307 }
308}
309
310/**
311 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
312 * @rqstp: incoming NLM request
313 * @hostname: name of client host
314 * @hostname_len: length of client hostname
315 *
316 * Returns an nlm_host structure that matches the [client address,
317 * transport protocol, NLM version, client hostname] of the passed-in
318 * NLM request. If one doesn't already exist in the host cache, a
319 * new handle is created and returned.
320 *
321 * Before possibly creating a new nlm_host, construct a sockaddr
322 * for a specific source address in case the local system has
323 * multiple network addresses. The family of the address in
324 * rq_daddr is guaranteed to be the same as the family of the
325 * address in rq_addr, so it's safe to use the same family for
326 * the source address.
327 */
328struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
329 const char *hostname,
330 const size_t hostname_len)
331{
332 struct hlist_head *chain;
333 struct nlm_host *host = NULL;
334 struct nsm_handle *nsm = NULL;
335 struct sockaddr *src_sap = svc_daddr(rqstp);
336 size_t src_len = rqstp->rq_daddrlen;
337 struct net *net = SVC_NET(rqstp);
338 struct nlm_lookup_host_info ni = {
339 .server = 1,
340 .sap = svc_addr(rqstp),
341 .salen = rqstp->rq_addrlen,
342 .protocol = rqstp->rq_prot,
343 .version = rqstp->rq_vers,
344 .hostname = hostname,
345 .hostname_len = hostname_len,
346 .net = net,
347 };
348 struct lockd_net *ln = net_generic(net, lockd_net_id);
349
350 dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
351 (int)hostname_len, hostname, rqstp->rq_vers,
352 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
353
354 mutex_lock(&nlm_host_mutex);
355
356 if (time_after_eq(jiffies, ln->next_gc))
357 nlm_gc_hosts(net);
358
359 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
360 hlist_for_each_entry(host, chain, h_hash) {
361 if (host->net != net)
362 continue;
363 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
364 continue;
365
366 /* Same address. Share an NSM handle if we already have one */
367 if (nsm == NULL)
368 nsm = host->h_nsmhandle;
369
370 if (host->h_proto != ni.protocol)
371 continue;
372 if (host->h_version != ni.version)
373 continue;
374 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
375 continue;
376
377 /* Move to head of hash chain. */
378 hlist_del(&host->h_hash);
379 hlist_add_head(&host->h_hash, chain);
380
381 nlm_get_host(host);
382 dprintk("lockd: %s found host %s (%s)\n",
383 __func__, host->h_name, host->h_addrbuf);
384 goto out;
385 }
386
387 host = nlm_alloc_host(&ni, nsm);
388 if (unlikely(host == NULL))
389 goto out;
390
391 memcpy(nlm_srcaddr(host), src_sap, src_len);
392 host->h_srcaddrlen = src_len;
393 hlist_add_head(&host->h_hash, chain);
394 ln->nrhosts++;
395 nrhosts++;
396
397 refcount_inc(&host->h_count);
398
399 dprintk("lockd: %s created host %s (%s)\n",
400 __func__, host->h_name, host->h_addrbuf);
401
402out:
403 mutex_unlock(&nlm_host_mutex);
404 return host;
405}
406
407/**
408 * nlmsvc_release_host - release server nlm_host
409 * @host: nlm_host to release
410 *
411 * Host is destroyed later in nlm_gc_host().
412 */
413void nlmsvc_release_host(struct nlm_host *host)
414{
415 if (host == NULL)
416 return;
417
418 dprintk("lockd: release server host %s\n", host->h_name);
419
420 WARN_ON_ONCE(!host->h_server);
421 refcount_dec(&host->h_count);
422}
423
424/*
425 * Create the NLM RPC client for an NLM peer
426 */
427struct rpc_clnt *
428nlm_bind_host(struct nlm_host *host)
429{
430 struct rpc_clnt *clnt;
431
432 dprintk("lockd: nlm_bind_host %s (%s)\n",
433 host->h_name, host->h_addrbuf);
434
435 /* Lock host handle */
436 mutex_lock(&host->h_mutex);
437
438 /* If we've already created an RPC client, check whether
439 * RPC rebind is required
440 */
441 if ((clnt = host->h_rpcclnt) != NULL) {
442 nlm_rebind_host(host);
443 } else {
444 unsigned long increment = nlmsvc_timeout;
445 struct rpc_timeout timeparms = {
446 .to_initval = increment,
447 .to_increment = increment,
448 .to_maxval = increment * 6UL,
449 .to_retries = 5U,
450 };
451 struct rpc_create_args args = {
452 .net = host->net,
453 .protocol = host->h_proto,
454 .address = nlm_addr(host),
455 .addrsize = host->h_addrlen,
456 .timeout = &timeparms,
457 .servername = host->h_name,
458 .program = &nlm_program,
459 .version = host->h_version,
460 .authflavor = RPC_AUTH_UNIX,
461 .flags = (RPC_CLNT_CREATE_NOPING |
462 RPC_CLNT_CREATE_AUTOBIND |
463 RPC_CLNT_CREATE_REUSEPORT),
464 .cred = host->h_cred,
465 };
466
467 /*
468 * lockd retries server side blocks automatically so we want
469 * those to be soft RPC calls. Client side calls need to be
470 * hard RPC tasks.
471 */
472 if (!host->h_server)
473 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
474 if (host->h_noresvport)
475 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
476 if (host->h_srcaddrlen)
477 args.saddress = nlm_srcaddr(host);
478
479 clnt = rpc_create(&args);
480 if (!IS_ERR(clnt))
481 host->h_rpcclnt = clnt;
482 else {
483 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
484 clnt = NULL;
485 }
486 }
487
488 mutex_unlock(&host->h_mutex);
489 return clnt;
490}
491
492/**
493 * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port
494 * @host: NLM host handle for peer
495 *
496 * This is not needed when using a connection-oriented protocol, such as TCP.
497 * The existing autobind mechanism is sufficient to force a rebind when
498 * required, e.g. on connection state transitions.
499 */
500void
501nlm_rebind_host(struct nlm_host *host)
502{
503 if (host->h_proto != IPPROTO_UDP)
504 return;
505
506 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
507 rpc_force_rebind(host->h_rpcclnt);
508 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
509 }
510}
511
512/*
513 * Increment NLM host count
514 */
515struct nlm_host * nlm_get_host(struct nlm_host *host)
516{
517 if (host) {
518 dprintk("lockd: get host %s\n", host->h_name);
519 refcount_inc(&host->h_count);
520 host->h_expires = jiffies + NLM_HOST_EXPIRE;
521 }
522 return host;
523}
524
525static struct nlm_host *next_host_state(struct hlist_head *cache,
526 struct nsm_handle *nsm,
527 const struct nlm_reboot *info)
528{
529 struct nlm_host *host;
530 struct hlist_head *chain;
531
532 mutex_lock(&nlm_host_mutex);
533 for_each_host(host, chain, cache) {
534 if (host->h_nsmhandle == nsm
535 && host->h_nsmstate != info->state) {
536 host->h_nsmstate = info->state;
537 host->h_state++;
538
539 nlm_get_host(host);
540 mutex_unlock(&nlm_host_mutex);
541 return host;
542 }
543 }
544
545 mutex_unlock(&nlm_host_mutex);
546 return NULL;
547}
548
549/**
550 * nlm_host_rebooted - Release all resources held by rebooted host
551 * @net: network namespace
552 * @info: pointer to decoded results of NLM_SM_NOTIFY call
553 *
554 * We were notified that the specified host has rebooted. Release
555 * all resources held by that peer.
556 */
557void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info)
558{
559 struct nsm_handle *nsm;
560 struct nlm_host *host;
561
562 nsm = nsm_reboot_lookup(net, info);
563 if (unlikely(nsm == NULL))
564 return;
565
566 /* Mark all hosts tied to this NSM state as having rebooted.
567 * We run the loop repeatedly, because we drop the host table
568 * lock for this.
569 * To avoid processing a host several times, we match the nsmstate.
570 */
571 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
572 nlmsvc_free_host_resources(host);
573 nlmsvc_release_host(host);
574 }
575 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
576 nlmclnt_recovery(host);
577 nlmclnt_release_host(host);
578 }
579
580 nsm_release(nsm);
581}
582
583static void nlm_complain_hosts(struct net *net)
584{
585 struct hlist_head *chain;
586 struct nlm_host *host;
587
588 if (net) {
589 struct lockd_net *ln = net_generic(net, lockd_net_id);
590
591 if (ln->nrhosts == 0)
592 return;
593 pr_warn("lockd: couldn't shutdown host module for net %x!\n",
594 net->ns.inum);
595 dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
596 net->ns.inum);
597 } else {
598 if (nrhosts == 0)
599 return;
600 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
601 dprintk("lockd: %lu hosts left:\n", nrhosts);
602 }
603
604 for_each_host(host, chain, nlm_server_hosts) {
605 if (net && host->net != net)
606 continue;
607 dprintk(" %s (cnt %d use %d exp %ld net %x)\n",
608 host->h_name, refcount_read(&host->h_count),
609 host->h_inuse, host->h_expires, host->net->ns.inum);
610 }
611}
612
613void
614nlm_shutdown_hosts_net(struct net *net)
615{
616 struct hlist_head *chain;
617 struct nlm_host *host;
618
619 mutex_lock(&nlm_host_mutex);
620
621 /* First, make all hosts eligible for gc */
622 dprintk("lockd: nuking all hosts in net %x...\n",
623 net ? net->ns.inum : 0);
624 for_each_host(host, chain, nlm_server_hosts) {
625 if (net && host->net != net)
626 continue;
627 host->h_expires = jiffies - 1;
628 if (host->h_rpcclnt) {
629 rpc_shutdown_client(host->h_rpcclnt);
630 host->h_rpcclnt = NULL;
631 }
632 }
633
634 /* Then, perform a garbage collection pass */
635 nlm_gc_hosts(net);
636 nlm_complain_hosts(net);
637 mutex_unlock(&nlm_host_mutex);
638}
639
640/*
641 * Shut down the hosts module.
642 * Note that this routine is called only at server shutdown time.
643 */
644void
645nlm_shutdown_hosts(void)
646{
647 dprintk("lockd: shutting down host module\n");
648 nlm_shutdown_hosts_net(NULL);
649}
650
651/*
652 * Garbage collect any unused NLM hosts.
653 * This GC combines reference counting for async operations with
654 * mark & sweep for resources held by remote clients.
655 */
656static void
657nlm_gc_hosts(struct net *net)
658{
659 struct hlist_head *chain;
660 struct hlist_node *next;
661 struct nlm_host *host;
662
663 dprintk("lockd: host garbage collection for net %x\n",
664 net ? net->ns.inum : 0);
665 for_each_host(host, chain, nlm_server_hosts) {
666 if (net && host->net != net)
667 continue;
668 host->h_inuse = 0;
669 }
670
671 /* Mark all hosts that hold locks, blocks or shares */
672 nlmsvc_mark_resources(net);
673
674 for_each_host_safe(host, next, chain, nlm_server_hosts) {
675 if (net && host->net != net)
676 continue;
677 if (host->h_inuse || time_before(jiffies, host->h_expires)) {
678 dprintk("nlm_gc_hosts skipping %s "
679 "(cnt %d use %d exp %ld net %x)\n",
680 host->h_name, refcount_read(&host->h_count),
681 host->h_inuse, host->h_expires,
682 host->net->ns.inum);
683 continue;
684 }
685 if (refcount_dec_if_one(&host->h_count))
686 nlm_destroy_host_locked(host);
687 }
688
689 if (net) {
690 struct lockd_net *ln = net_generic(net, lockd_net_id);
691
692 ln->next_gc = jiffies + NLM_HOST_COLLECT;
693 }
694}