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