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