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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/*
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};