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