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1/*
2 * linux/fs/lockd/mon.c
3 *
4 * The kernel statd client.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/kernel.h>
11#include <linux/ktime.h>
12#include <linux/slab.h>
13
14#include <linux/sunrpc/clnt.h>
15#include <linux/sunrpc/addr.h>
16#include <linux/sunrpc/xprtsock.h>
17#include <linux/sunrpc/svc.h>
18#include <linux/lockd/lockd.h>
19
20#include <asm/unaligned.h>
21
22#include "netns.h"
23
24#define NLMDBG_FACILITY NLMDBG_MONITOR
25#define NSM_PROGRAM 100024
26#define NSM_VERSION 1
27
28enum {
29 NSMPROC_NULL,
30 NSMPROC_STAT,
31 NSMPROC_MON,
32 NSMPROC_UNMON,
33 NSMPROC_UNMON_ALL,
34 NSMPROC_SIMU_CRASH,
35 NSMPROC_NOTIFY,
36};
37
38struct nsm_args {
39 struct nsm_private *priv;
40 u32 prog; /* RPC callback info */
41 u32 vers;
42 u32 proc;
43
44 char *mon_name;
45 char *nodename;
46};
47
48struct nsm_res {
49 u32 status;
50 u32 state;
51};
52
53static const struct rpc_program nsm_program;
54static LIST_HEAD(nsm_handles);
55static DEFINE_SPINLOCK(nsm_lock);
56
57/*
58 * Local NSM state
59 */
60u32 __read_mostly nsm_local_state;
61bool __read_mostly nsm_use_hostnames;
62
63static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
64{
65 return (struct sockaddr *)&nsm->sm_addr;
66}
67
68static struct rpc_clnt *nsm_create(struct net *net)
69{
70 struct sockaddr_in sin = {
71 .sin_family = AF_INET,
72 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
73 };
74 struct rpc_create_args args = {
75 .net = net,
76 .protocol = XPRT_TRANSPORT_TCP,
77 .address = (struct sockaddr *)&sin,
78 .addrsize = sizeof(sin),
79 .servername = "rpc.statd",
80 .program = &nsm_program,
81 .version = NSM_VERSION,
82 .authflavor = RPC_AUTH_NULL,
83 .flags = RPC_CLNT_CREATE_NOPING,
84 };
85
86 return rpc_create(&args);
87}
88
89static struct rpc_clnt *nsm_client_set(struct lockd_net *ln,
90 struct rpc_clnt *clnt)
91{
92 spin_lock(&ln->nsm_clnt_lock);
93 if (ln->nsm_users == 0) {
94 if (clnt == NULL)
95 goto out;
96 ln->nsm_clnt = clnt;
97 }
98 clnt = ln->nsm_clnt;
99 ln->nsm_users++;
100out:
101 spin_unlock(&ln->nsm_clnt_lock);
102 return clnt;
103}
104
105static struct rpc_clnt *nsm_client_get(struct net *net)
106{
107 struct rpc_clnt *clnt, *new;
108 struct lockd_net *ln = net_generic(net, lockd_net_id);
109
110 clnt = nsm_client_set(ln, NULL);
111 if (clnt != NULL)
112 goto out;
113
114 clnt = new = nsm_create(net);
115 if (IS_ERR(clnt))
116 goto out;
117
118 clnt = nsm_client_set(ln, new);
119 if (clnt != new)
120 rpc_shutdown_client(new);
121out:
122 return clnt;
123}
124
125static void nsm_client_put(struct net *net)
126{
127 struct lockd_net *ln = net_generic(net, lockd_net_id);
128 struct rpc_clnt *clnt = NULL;
129
130 spin_lock(&ln->nsm_clnt_lock);
131 ln->nsm_users--;
132 if (ln->nsm_users == 0) {
133 clnt = ln->nsm_clnt;
134 ln->nsm_clnt = NULL;
135 }
136 spin_unlock(&ln->nsm_clnt_lock);
137 if (clnt != NULL)
138 rpc_shutdown_client(clnt);
139}
140
141static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
142 struct rpc_clnt *clnt)
143{
144 int status;
145 struct nsm_args args = {
146 .priv = &nsm->sm_priv,
147 .prog = NLM_PROGRAM,
148 .vers = 3,
149 .proc = NLMPROC_NSM_NOTIFY,
150 .mon_name = nsm->sm_mon_name,
151 .nodename = clnt->cl_nodename,
152 };
153 struct rpc_message msg = {
154 .rpc_argp = &args,
155 .rpc_resp = res,
156 };
157
158 memset(res, 0, sizeof(*res));
159
160 msg.rpc_proc = &clnt->cl_procinfo[proc];
161 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
162 if (status < 0)
163 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
164 status);
165 else
166 status = 0;
167 return status;
168}
169
170/**
171 * nsm_monitor - Notify a peer in case we reboot
172 * @host: pointer to nlm_host of peer to notify
173 *
174 * If this peer is not already monitored, this function sends an
175 * upcall to the local rpc.statd to record the name/address of
176 * the peer to notify in case we reboot.
177 *
178 * Returns zero if the peer is monitored by the local rpc.statd;
179 * otherwise a negative errno value is returned.
180 */
181int nsm_monitor(const struct nlm_host *host)
182{
183 struct nsm_handle *nsm = host->h_nsmhandle;
184 struct nsm_res res;
185 int status;
186 struct rpc_clnt *clnt;
187
188 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
189
190 if (nsm->sm_monitored)
191 return 0;
192
193 /*
194 * Choose whether to record the caller_name or IP address of
195 * this peer in the local rpc.statd's database.
196 */
197 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
198
199 clnt = nsm_client_get(host->net);
200 if (IS_ERR(clnt)) {
201 status = PTR_ERR(clnt);
202 dprintk("lockd: failed to create NSM upcall transport, "
203 "status=%d, net=%p\n", status, host->net);
204 return status;
205 }
206
207 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, clnt);
208 if (unlikely(res.status != 0))
209 status = -EIO;
210 if (unlikely(status < 0)) {
211 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
212 return status;
213 }
214
215 nsm->sm_monitored = 1;
216 if (unlikely(nsm_local_state != res.state)) {
217 nsm_local_state = res.state;
218 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
219 }
220 return 0;
221}
222
223/**
224 * nsm_unmonitor - Unregister peer notification
225 * @host: pointer to nlm_host of peer to stop monitoring
226 *
227 * If this peer is monitored, this function sends an upcall to
228 * tell the local rpc.statd not to send this peer a notification
229 * when we reboot.
230 */
231void nsm_unmonitor(const struct nlm_host *host)
232{
233 struct nsm_handle *nsm = host->h_nsmhandle;
234 struct nsm_res res;
235 int status;
236
237 if (atomic_read(&nsm->sm_count) == 1
238 && nsm->sm_monitored && !nsm->sm_sticky) {
239 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
240
241 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
242
243 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, ln->nsm_clnt);
244 if (res.status != 0)
245 status = -EIO;
246 if (status < 0)
247 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
248 nsm->sm_name);
249 else
250 nsm->sm_monitored = 0;
251
252 nsm_client_put(host->net);
253 }
254}
255
256static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
257 const size_t len)
258{
259 struct nsm_handle *nsm;
260
261 list_for_each_entry(nsm, &nsm_handles, sm_link)
262 if (strlen(nsm->sm_name) == len &&
263 memcmp(nsm->sm_name, hostname, len) == 0)
264 return nsm;
265 return NULL;
266}
267
268static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
269{
270 struct nsm_handle *nsm;
271
272 list_for_each_entry(nsm, &nsm_handles, sm_link)
273 if (rpc_cmp_addr(nsm_addr(nsm), sap))
274 return nsm;
275 return NULL;
276}
277
278static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
279{
280 struct nsm_handle *nsm;
281
282 list_for_each_entry(nsm, &nsm_handles, sm_link)
283 if (memcmp(nsm->sm_priv.data, priv->data,
284 sizeof(priv->data)) == 0)
285 return nsm;
286 return NULL;
287}
288
289/*
290 * Construct a unique cookie to match this nsm_handle to this monitored
291 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
292 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
293 * requests.
294 *
295 * The NSM protocol requires that these cookies be unique while the
296 * system is running. We prefer a stronger requirement of making them
297 * unique across reboots. If user space bugs cause a stale cookie to
298 * be sent to the kernel, it could cause the wrong host to lose its
299 * lock state if cookies were not unique across reboots.
300 *
301 * The cookies are exposed only to local user space via loopback. They
302 * do not appear on the physical network. If we want greater security
303 * for some reason, nsm_init_private() could perform a one-way hash to
304 * obscure the contents of the cookie.
305 */
306static void nsm_init_private(struct nsm_handle *nsm)
307{
308 u64 *p = (u64 *)&nsm->sm_priv.data;
309 struct timespec ts;
310 s64 ns;
311
312 ktime_get_ts(&ts);
313 ns = timespec_to_ns(&ts);
314 put_unaligned(ns, p);
315 put_unaligned((unsigned long)nsm, p + 1);
316}
317
318static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
319 const size_t salen,
320 const char *hostname,
321 const size_t hostname_len)
322{
323 struct nsm_handle *new;
324
325 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
326 if (unlikely(new == NULL))
327 return NULL;
328
329 atomic_set(&new->sm_count, 1);
330 new->sm_name = (char *)(new + 1);
331 memcpy(nsm_addr(new), sap, salen);
332 new->sm_addrlen = salen;
333 nsm_init_private(new);
334
335 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
336 sizeof(new->sm_addrbuf)) == 0)
337 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
338 "unsupported address family");
339 memcpy(new->sm_name, hostname, hostname_len);
340 new->sm_name[hostname_len] = '\0';
341
342 return new;
343}
344
345/**
346 * nsm_get_handle - Find or create a cached nsm_handle
347 * @sap: pointer to socket address of handle to find
348 * @salen: length of socket address
349 * @hostname: pointer to C string containing hostname to find
350 * @hostname_len: length of C string
351 *
352 * Behavior is modulated by the global nsm_use_hostnames variable.
353 *
354 * Returns a cached nsm_handle after bumping its ref count, or
355 * returns a fresh nsm_handle if a handle that matches @sap and/or
356 * @hostname cannot be found in the handle cache. Returns NULL if
357 * an error occurs.
358 */
359struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
360 const size_t salen, const char *hostname,
361 const size_t hostname_len)
362{
363 struct nsm_handle *cached, *new = NULL;
364
365 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
366 if (printk_ratelimit()) {
367 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
368 "in NFS lock request\n",
369 (int)hostname_len, hostname);
370 }
371 return NULL;
372 }
373
374retry:
375 spin_lock(&nsm_lock);
376
377 if (nsm_use_hostnames && hostname != NULL)
378 cached = nsm_lookup_hostname(hostname, hostname_len);
379 else
380 cached = nsm_lookup_addr(sap);
381
382 if (cached != NULL) {
383 atomic_inc(&cached->sm_count);
384 spin_unlock(&nsm_lock);
385 kfree(new);
386 dprintk("lockd: found nsm_handle for %s (%s), "
387 "cnt %d\n", cached->sm_name,
388 cached->sm_addrbuf,
389 atomic_read(&cached->sm_count));
390 return cached;
391 }
392
393 if (new != NULL) {
394 list_add(&new->sm_link, &nsm_handles);
395 spin_unlock(&nsm_lock);
396 dprintk("lockd: created nsm_handle for %s (%s)\n",
397 new->sm_name, new->sm_addrbuf);
398 return new;
399 }
400
401 spin_unlock(&nsm_lock);
402
403 new = nsm_create_handle(sap, salen, hostname, hostname_len);
404 if (unlikely(new == NULL))
405 return NULL;
406 goto retry;
407}
408
409/**
410 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
411 * @info: pointer to NLMPROC_SM_NOTIFY arguments
412 *
413 * Returns a matching nsm_handle if found in the nsm cache. The returned
414 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
415 * error occurred.
416 */
417struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
418{
419 struct nsm_handle *cached;
420
421 spin_lock(&nsm_lock);
422
423 cached = nsm_lookup_priv(&info->priv);
424 if (unlikely(cached == NULL)) {
425 spin_unlock(&nsm_lock);
426 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
427 info->len, info->mon);
428 return cached;
429 }
430
431 atomic_inc(&cached->sm_count);
432 spin_unlock(&nsm_lock);
433
434 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
435 cached->sm_name, cached->sm_addrbuf,
436 atomic_read(&cached->sm_count));
437 return cached;
438}
439
440/**
441 * nsm_release - Release an NSM handle
442 * @nsm: pointer to handle to be released
443 *
444 */
445void nsm_release(struct nsm_handle *nsm)
446{
447 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
448 list_del(&nsm->sm_link);
449 spin_unlock(&nsm_lock);
450 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
451 nsm->sm_name, nsm->sm_addrbuf);
452 kfree(nsm);
453 }
454}
455
456/*
457 * XDR functions for NSM.
458 *
459 * See http://www.opengroup.org/ for details on the Network
460 * Status Monitor wire protocol.
461 */
462
463static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
464{
465 const u32 len = strlen(string);
466 __be32 *p;
467
468 p = xdr_reserve_space(xdr, 4 + len);
469 xdr_encode_opaque(p, string, len);
470}
471
472/*
473 * "mon_name" specifies the host to be monitored.
474 */
475static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
476{
477 encode_nsm_string(xdr, argp->mon_name);
478}
479
480/*
481 * The "my_id" argument specifies the hostname and RPC procedure
482 * to be called when the status manager receives notification
483 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
484 * has changed.
485 */
486static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
487{
488 __be32 *p;
489
490 encode_nsm_string(xdr, argp->nodename);
491 p = xdr_reserve_space(xdr, 4 + 4 + 4);
492 *p++ = cpu_to_be32(argp->prog);
493 *p++ = cpu_to_be32(argp->vers);
494 *p = cpu_to_be32(argp->proc);
495}
496
497/*
498 * The "mon_id" argument specifies the non-private arguments
499 * of an NSMPROC_MON or NSMPROC_UNMON call.
500 */
501static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
502{
503 encode_mon_name(xdr, argp);
504 encode_my_id(xdr, argp);
505}
506
507/*
508 * The "priv" argument may contain private information required
509 * by the NSMPROC_MON call. This information will be supplied in the
510 * NLMPROC_SM_NOTIFY call.
511 */
512static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
513{
514 __be32 *p;
515
516 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
517 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
518}
519
520static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
521 const struct nsm_args *argp)
522{
523 encode_mon_id(xdr, argp);
524 encode_priv(xdr, argp);
525}
526
527static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
528 const struct nsm_args *argp)
529{
530 encode_mon_id(xdr, argp);
531}
532
533static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
534 struct xdr_stream *xdr,
535 struct nsm_res *resp)
536{
537 __be32 *p;
538
539 p = xdr_inline_decode(xdr, 4 + 4);
540 if (unlikely(p == NULL))
541 return -EIO;
542 resp->status = be32_to_cpup(p++);
543 resp->state = be32_to_cpup(p);
544
545 dprintk("lockd: %s status %d state %d\n",
546 __func__, resp->status, resp->state);
547 return 0;
548}
549
550static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
551 struct xdr_stream *xdr,
552 struct nsm_res *resp)
553{
554 __be32 *p;
555
556 p = xdr_inline_decode(xdr, 4);
557 if (unlikely(p == NULL))
558 return -EIO;
559 resp->state = be32_to_cpup(p);
560
561 dprintk("lockd: %s state %d\n", __func__, resp->state);
562 return 0;
563}
564
565#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
566#define SM_my_id_sz (SM_my_name_sz+3)
567#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
568#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
569#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
570#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
571#define SM_monres_sz 2
572#define SM_unmonres_sz 1
573
574static struct rpc_procinfo nsm_procedures[] = {
575[NSMPROC_MON] = {
576 .p_proc = NSMPROC_MON,
577 .p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
578 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
579 .p_arglen = SM_mon_sz,
580 .p_replen = SM_monres_sz,
581 .p_statidx = NSMPROC_MON,
582 .p_name = "MONITOR",
583 },
584[NSMPROC_UNMON] = {
585 .p_proc = NSMPROC_UNMON,
586 .p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
587 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
588 .p_arglen = SM_mon_id_sz,
589 .p_replen = SM_unmonres_sz,
590 .p_statidx = NSMPROC_UNMON,
591 .p_name = "UNMONITOR",
592 },
593};
594
595static const struct rpc_version nsm_version1 = {
596 .number = 1,
597 .nrprocs = ARRAY_SIZE(nsm_procedures),
598 .procs = nsm_procedures
599};
600
601static const struct rpc_version *nsm_version[] = {
602 [1] = &nsm_version1,
603};
604
605static struct rpc_stat nsm_stats;
606
607static const struct rpc_program nsm_program = {
608 .name = "statd",
609 .number = NSM_PROGRAM,
610 .nrvers = ARRAY_SIZE(nsm_version),
611 .version = nsm_version,
612 .stats = &nsm_stats
613};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/mon.c
4 *
5 * The kernel statd client.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/ktime.h>
13#include <linux/slab.h>
14
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/addr.h>
17#include <linux/sunrpc/xprtsock.h>
18#include <linux/sunrpc/svc.h>
19#include <linux/lockd/lockd.h>
20
21#include <asm/unaligned.h>
22
23#include "netns.h"
24
25#define NLMDBG_FACILITY NLMDBG_MONITOR
26#define NSM_PROGRAM 100024
27#define NSM_VERSION 1
28
29enum {
30 NSMPROC_NULL,
31 NSMPROC_STAT,
32 NSMPROC_MON,
33 NSMPROC_UNMON,
34 NSMPROC_UNMON_ALL,
35 NSMPROC_SIMU_CRASH,
36 NSMPROC_NOTIFY,
37};
38
39struct nsm_args {
40 struct nsm_private *priv;
41 u32 prog; /* RPC callback info */
42 u32 vers;
43 u32 proc;
44
45 char *mon_name;
46 const char *nodename;
47};
48
49struct nsm_res {
50 u32 status;
51 u32 state;
52};
53
54static const struct rpc_program nsm_program;
55static DEFINE_SPINLOCK(nsm_lock);
56
57/*
58 * Local NSM state
59 */
60u32 __read_mostly nsm_local_state;
61bool __read_mostly nsm_use_hostnames;
62
63static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
64{
65 return (struct sockaddr *)&nsm->sm_addr;
66}
67
68static struct rpc_clnt *nsm_create(struct net *net, const char *nodename)
69{
70 struct sockaddr_in sin = {
71 .sin_family = AF_INET,
72 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
73 };
74 struct rpc_create_args args = {
75 .net = net,
76 .protocol = XPRT_TRANSPORT_TCP,
77 .address = (struct sockaddr *)&sin,
78 .addrsize = sizeof(sin),
79 .servername = "rpc.statd",
80 .nodename = nodename,
81 .program = &nsm_program,
82 .version = NSM_VERSION,
83 .authflavor = RPC_AUTH_NULL,
84 .flags = RPC_CLNT_CREATE_NOPING,
85 };
86
87 return rpc_create(&args);
88}
89
90static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
91 const struct nlm_host *host)
92{
93 int status;
94 struct rpc_clnt *clnt;
95 struct nsm_args args = {
96 .priv = &nsm->sm_priv,
97 .prog = NLM_PROGRAM,
98 .vers = 3,
99 .proc = NLMPROC_NSM_NOTIFY,
100 .mon_name = nsm->sm_mon_name,
101 .nodename = host->nodename,
102 };
103 struct rpc_message msg = {
104 .rpc_argp = &args,
105 .rpc_resp = res,
106 };
107
108 memset(res, 0, sizeof(*res));
109
110 clnt = nsm_create(host->net, host->nodename);
111 if (IS_ERR(clnt)) {
112 dprintk("lockd: failed to create NSM upcall transport, "
113 "status=%ld, net=%x\n", PTR_ERR(clnt),
114 host->net->ns.inum);
115 return PTR_ERR(clnt);
116 }
117
118 msg.rpc_proc = &clnt->cl_procinfo[proc];
119 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
120 if (status == -ECONNREFUSED) {
121 dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
122 status);
123 rpc_force_rebind(clnt);
124 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
125 }
126 if (status < 0)
127 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
128 status);
129 else
130 status = 0;
131
132 rpc_shutdown_client(clnt);
133 return status;
134}
135
136/**
137 * nsm_monitor - Notify a peer in case we reboot
138 * @host: pointer to nlm_host of peer to notify
139 *
140 * If this peer is not already monitored, this function sends an
141 * upcall to the local rpc.statd to record the name/address of
142 * the peer to notify in case we reboot.
143 *
144 * Returns zero if the peer is monitored by the local rpc.statd;
145 * otherwise a negative errno value is returned.
146 */
147int nsm_monitor(const struct nlm_host *host)
148{
149 struct nsm_handle *nsm = host->h_nsmhandle;
150 struct nsm_res res;
151 int status;
152
153 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
154
155 if (nsm->sm_monitored)
156 return 0;
157
158 /*
159 * Choose whether to record the caller_name or IP address of
160 * this peer in the local rpc.statd's database.
161 */
162 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
163
164 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);
165 if (unlikely(res.status != 0))
166 status = -EIO;
167 if (unlikely(status < 0)) {
168 pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
169 return status;
170 }
171
172 nsm->sm_monitored = 1;
173 if (unlikely(nsm_local_state != res.state)) {
174 nsm_local_state = res.state;
175 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
176 }
177 return 0;
178}
179
180/**
181 * nsm_unmonitor - Unregister peer notification
182 * @host: pointer to nlm_host of peer to stop monitoring
183 *
184 * If this peer is monitored, this function sends an upcall to
185 * tell the local rpc.statd not to send this peer a notification
186 * when we reboot.
187 */
188void nsm_unmonitor(const struct nlm_host *host)
189{
190 struct nsm_handle *nsm = host->h_nsmhandle;
191 struct nsm_res res;
192 int status;
193
194 if (refcount_read(&nsm->sm_count) == 1
195 && nsm->sm_monitored && !nsm->sm_sticky) {
196 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
197
198 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);
199 if (res.status != 0)
200 status = -EIO;
201 if (status < 0)
202 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
203 nsm->sm_name);
204 else
205 nsm->sm_monitored = 0;
206 }
207}
208
209static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles,
210 const char *hostname, const size_t len)
211{
212 struct nsm_handle *nsm;
213
214 list_for_each_entry(nsm, nsm_handles, sm_link)
215 if (strlen(nsm->sm_name) == len &&
216 memcmp(nsm->sm_name, hostname, len) == 0)
217 return nsm;
218 return NULL;
219}
220
221static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles,
222 const struct sockaddr *sap)
223{
224 struct nsm_handle *nsm;
225
226 list_for_each_entry(nsm, nsm_handles, sm_link)
227 if (rpc_cmp_addr(nsm_addr(nsm), sap))
228 return nsm;
229 return NULL;
230}
231
232static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles,
233 const struct nsm_private *priv)
234{
235 struct nsm_handle *nsm;
236
237 list_for_each_entry(nsm, nsm_handles, sm_link)
238 if (memcmp(nsm->sm_priv.data, priv->data,
239 sizeof(priv->data)) == 0)
240 return nsm;
241 return NULL;
242}
243
244/*
245 * Construct a unique cookie to match this nsm_handle to this monitored
246 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
247 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
248 * requests.
249 *
250 * The NSM protocol requires that these cookies be unique while the
251 * system is running. We prefer a stronger requirement of making them
252 * unique across reboots. If user space bugs cause a stale cookie to
253 * be sent to the kernel, it could cause the wrong host to lose its
254 * lock state if cookies were not unique across reboots.
255 *
256 * The cookies are exposed only to local user space via loopback. They
257 * do not appear on the physical network. If we want greater security
258 * for some reason, nsm_init_private() could perform a one-way hash to
259 * obscure the contents of the cookie.
260 */
261static void nsm_init_private(struct nsm_handle *nsm)
262{
263 u64 *p = (u64 *)&nsm->sm_priv.data;
264 s64 ns;
265
266 ns = ktime_get_ns();
267 put_unaligned(ns, p);
268 put_unaligned((unsigned long)nsm, p + 1);
269}
270
271static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
272 const size_t salen,
273 const char *hostname,
274 const size_t hostname_len)
275{
276 struct nsm_handle *new;
277
278 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
279 if (unlikely(new == NULL))
280 return NULL;
281
282 refcount_set(&new->sm_count, 1);
283 new->sm_name = (char *)(new + 1);
284 memcpy(nsm_addr(new), sap, salen);
285 new->sm_addrlen = salen;
286 nsm_init_private(new);
287
288 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
289 sizeof(new->sm_addrbuf)) == 0)
290 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
291 "unsupported address family");
292 memcpy(new->sm_name, hostname, hostname_len);
293 new->sm_name[hostname_len] = '\0';
294
295 return new;
296}
297
298/**
299 * nsm_get_handle - Find or create a cached nsm_handle
300 * @net: network namespace
301 * @sap: pointer to socket address of handle to find
302 * @salen: length of socket address
303 * @hostname: pointer to C string containing hostname to find
304 * @hostname_len: length of C string
305 *
306 * Behavior is modulated by the global nsm_use_hostnames variable.
307 *
308 * Returns a cached nsm_handle after bumping its ref count, or
309 * returns a fresh nsm_handle if a handle that matches @sap and/or
310 * @hostname cannot be found in the handle cache. Returns NULL if
311 * an error occurs.
312 */
313struct nsm_handle *nsm_get_handle(const struct net *net,
314 const struct sockaddr *sap,
315 const size_t salen, const char *hostname,
316 const size_t hostname_len)
317{
318 struct nsm_handle *cached, *new = NULL;
319 struct lockd_net *ln = net_generic(net, lockd_net_id);
320
321 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
322 if (printk_ratelimit()) {
323 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
324 "in NFS lock request\n",
325 (int)hostname_len, hostname);
326 }
327 return NULL;
328 }
329
330retry:
331 spin_lock(&nsm_lock);
332
333 if (nsm_use_hostnames && hostname != NULL)
334 cached = nsm_lookup_hostname(&ln->nsm_handles,
335 hostname, hostname_len);
336 else
337 cached = nsm_lookup_addr(&ln->nsm_handles, sap);
338
339 if (cached != NULL) {
340 refcount_inc(&cached->sm_count);
341 spin_unlock(&nsm_lock);
342 kfree(new);
343 dprintk("lockd: found nsm_handle for %s (%s), "
344 "cnt %d\n", cached->sm_name,
345 cached->sm_addrbuf,
346 refcount_read(&cached->sm_count));
347 return cached;
348 }
349
350 if (new != NULL) {
351 list_add(&new->sm_link, &ln->nsm_handles);
352 spin_unlock(&nsm_lock);
353 dprintk("lockd: created nsm_handle for %s (%s)\n",
354 new->sm_name, new->sm_addrbuf);
355 return new;
356 }
357
358 spin_unlock(&nsm_lock);
359
360 new = nsm_create_handle(sap, salen, hostname, hostname_len);
361 if (unlikely(new == NULL))
362 return NULL;
363 goto retry;
364}
365
366/**
367 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
368 * @net: network namespace
369 * @info: pointer to NLMPROC_SM_NOTIFY arguments
370 *
371 * Returns a matching nsm_handle if found in the nsm cache. The returned
372 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
373 * error occurred.
374 */
375struct nsm_handle *nsm_reboot_lookup(const struct net *net,
376 const struct nlm_reboot *info)
377{
378 struct nsm_handle *cached;
379 struct lockd_net *ln = net_generic(net, lockd_net_id);
380
381 spin_lock(&nsm_lock);
382
383 cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv);
384 if (unlikely(cached == NULL)) {
385 spin_unlock(&nsm_lock);
386 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
387 info->len, info->mon);
388 return cached;
389 }
390
391 refcount_inc(&cached->sm_count);
392 spin_unlock(&nsm_lock);
393
394 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
395 cached->sm_name, cached->sm_addrbuf,
396 refcount_read(&cached->sm_count));
397 return cached;
398}
399
400/**
401 * nsm_release - Release an NSM handle
402 * @nsm: pointer to handle to be released
403 *
404 */
405void nsm_release(struct nsm_handle *nsm)
406{
407 if (refcount_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
408 list_del(&nsm->sm_link);
409 spin_unlock(&nsm_lock);
410 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
411 nsm->sm_name, nsm->sm_addrbuf);
412 kfree(nsm);
413 }
414}
415
416/*
417 * XDR functions for NSM.
418 *
419 * See http://www.opengroup.org/ for details on the Network
420 * Status Monitor wire protocol.
421 */
422
423static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
424{
425 const u32 len = strlen(string);
426 __be32 *p;
427
428 p = xdr_reserve_space(xdr, 4 + len);
429 xdr_encode_opaque(p, string, len);
430}
431
432/*
433 * "mon_name" specifies the host to be monitored.
434 */
435static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
436{
437 encode_nsm_string(xdr, argp->mon_name);
438}
439
440/*
441 * The "my_id" argument specifies the hostname and RPC procedure
442 * to be called when the status manager receives notification
443 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
444 * has changed.
445 */
446static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
447{
448 __be32 *p;
449
450 encode_nsm_string(xdr, argp->nodename);
451 p = xdr_reserve_space(xdr, 4 + 4 + 4);
452 *p++ = cpu_to_be32(argp->prog);
453 *p++ = cpu_to_be32(argp->vers);
454 *p = cpu_to_be32(argp->proc);
455}
456
457/*
458 * The "mon_id" argument specifies the non-private arguments
459 * of an NSMPROC_MON or NSMPROC_UNMON call.
460 */
461static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
462{
463 encode_mon_name(xdr, argp);
464 encode_my_id(xdr, argp);
465}
466
467/*
468 * The "priv" argument may contain private information required
469 * by the NSMPROC_MON call. This information will be supplied in the
470 * NLMPROC_SM_NOTIFY call.
471 */
472static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
473{
474 __be32 *p;
475
476 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
477 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
478}
479
480static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
481 const void *argp)
482{
483 encode_mon_id(xdr, argp);
484 encode_priv(xdr, argp);
485}
486
487static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
488 const void *argp)
489{
490 encode_mon_id(xdr, argp);
491}
492
493static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
494 struct xdr_stream *xdr,
495 void *data)
496{
497 struct nsm_res *resp = data;
498 __be32 *p;
499
500 p = xdr_inline_decode(xdr, 4 + 4);
501 if (unlikely(p == NULL))
502 return -EIO;
503 resp->status = be32_to_cpup(p++);
504 resp->state = be32_to_cpup(p);
505
506 dprintk("lockd: %s status %d state %d\n",
507 __func__, resp->status, resp->state);
508 return 0;
509}
510
511static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
512 struct xdr_stream *xdr,
513 void *data)
514{
515 struct nsm_res *resp = data;
516 __be32 *p;
517
518 p = xdr_inline_decode(xdr, 4);
519 if (unlikely(p == NULL))
520 return -EIO;
521 resp->state = be32_to_cpup(p);
522
523 dprintk("lockd: %s state %d\n", __func__, resp->state);
524 return 0;
525}
526
527#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
528#define SM_my_id_sz (SM_my_name_sz+3)
529#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
530#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
531#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
532#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
533#define SM_monres_sz 2
534#define SM_unmonres_sz 1
535
536static const struct rpc_procinfo nsm_procedures[] = {
537[NSMPROC_MON] = {
538 .p_proc = NSMPROC_MON,
539 .p_encode = nsm_xdr_enc_mon,
540 .p_decode = nsm_xdr_dec_stat_res,
541 .p_arglen = SM_mon_sz,
542 .p_replen = SM_monres_sz,
543 .p_statidx = NSMPROC_MON,
544 .p_name = "MONITOR",
545 },
546[NSMPROC_UNMON] = {
547 .p_proc = NSMPROC_UNMON,
548 .p_encode = nsm_xdr_enc_unmon,
549 .p_decode = nsm_xdr_dec_stat,
550 .p_arglen = SM_mon_id_sz,
551 .p_replen = SM_unmonres_sz,
552 .p_statidx = NSMPROC_UNMON,
553 .p_name = "UNMONITOR",
554 },
555};
556
557static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)];
558static const struct rpc_version nsm_version1 = {
559 .number = 1,
560 .nrprocs = ARRAY_SIZE(nsm_procedures),
561 .procs = nsm_procedures,
562 .counts = nsm_version1_counts,
563};
564
565static const struct rpc_version *nsm_version[] = {
566 [1] = &nsm_version1,
567};
568
569static struct rpc_stat nsm_stats;
570
571static const struct rpc_program nsm_program = {
572 .name = "statd",
573 .number = NSM_PROGRAM,
574 .nrvers = ARRAY_SIZE(nsm_version),
575 .version = nsm_version,
576 .stats = &nsm_stats
577};