4 * The kernel statd client.
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/xprtsock.h>
17 #include <linux/sunrpc/svc.h>
18 #include <linux/lockd/lockd.h>
20 #include <asm/unaligned.h>
24 #define NLMDBG_FACILITY NLMDBG_MONITOR
25 #define NSM_PROGRAM 100024
39 struct nsm_private *priv;
40 u32 prog; /* RPC callback info */
52 static const struct rpc_program nsm_program;
53 static LIST_HEAD(nsm_handles);
54 static DEFINE_SPINLOCK(nsm_lock);
59 u32 __read_mostly nsm_local_state;
60 bool __read_mostly nsm_use_hostnames;
62 static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
64 return (struct sockaddr *)&nsm->sm_addr;
67 static struct rpc_clnt *nsm_create(struct net *net)
69 struct sockaddr_in sin = {
70 .sin_family = AF_INET,
71 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
73 struct rpc_create_args args = {
75 .protocol = XPRT_TRANSPORT_TCP,
76 .address = (struct sockaddr *)&sin,
77 .addrsize = sizeof(sin),
78 .servername = "rpc.statd",
79 .program = &nsm_program,
80 .version = NSM_VERSION,
81 .authflavor = RPC_AUTH_NULL,
82 .flags = RPC_CLNT_CREATE_NOPING,
85 return rpc_create(&args);
88 __maybe_unused static struct rpc_clnt *nsm_client_get(struct net *net)
90 static DEFINE_MUTEX(nsm_create_mutex);
91 struct rpc_clnt *clnt;
92 struct lockd_net *ln = net_generic(net, lockd_net_id);
94 spin_lock(&ln->nsm_clnt_lock);
98 spin_unlock(&ln->nsm_clnt_lock);
101 spin_unlock(&ln->nsm_clnt_lock);
103 mutex_lock(&nsm_create_mutex);
104 clnt = nsm_create(net);
110 mutex_unlock(&nsm_create_mutex);
115 __maybe_unused static void nsm_client_put(struct net *net)
117 struct lockd_net *ln = net_generic(net, lockd_net_id);
118 struct rpc_clnt *clnt = ln->nsm_clnt;
121 spin_lock(&ln->nsm_clnt_lock);
125 shutdown = !ln->nsm_users;
127 spin_unlock(&ln->nsm_clnt_lock);
130 rpc_shutdown_client(clnt);
133 static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
136 struct rpc_clnt *clnt;
138 struct nsm_args args = {
139 .priv = &nsm->sm_priv,
142 .proc = NLMPROC_NSM_NOTIFY,
143 .mon_name = nsm->sm_mon_name,
145 struct rpc_message msg = {
150 clnt = nsm_create(net);
152 status = PTR_ERR(clnt);
153 dprintk("lockd: failed to create NSM upcall transport, "
154 "status=%d\n", status);
158 memset(res, 0, sizeof(*res));
160 msg.rpc_proc = &clnt->cl_procinfo[proc];
161 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
163 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
167 rpc_shutdown_client(clnt);
173 * nsm_monitor - Notify a peer in case we reboot
174 * @host: pointer to nlm_host of peer to notify
176 * If this peer is not already monitored, this function sends an
177 * upcall to the local rpc.statd to record the name/address of
178 * the peer to notify in case we reboot.
180 * Returns zero if the peer is monitored by the local rpc.statd;
181 * otherwise a negative errno value is returned.
183 int nsm_monitor(const struct nlm_host *host)
185 struct nsm_handle *nsm = host->h_nsmhandle;
189 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
191 if (nsm->sm_monitored)
195 * Choose whether to record the caller_name or IP address of
196 * this peer in the local rpc.statd's database.
198 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
200 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host->net);
201 if (unlikely(res.status != 0))
203 if (unlikely(status < 0)) {
204 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
208 nsm->sm_monitored = 1;
209 if (unlikely(nsm_local_state != res.state)) {
210 nsm_local_state = res.state;
211 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
217 * nsm_unmonitor - Unregister peer notification
218 * @host: pointer to nlm_host of peer to stop monitoring
220 * If this peer is monitored, this function sends an upcall to
221 * tell the local rpc.statd not to send this peer a notification
224 void nsm_unmonitor(const struct nlm_host *host)
226 struct nsm_handle *nsm = host->h_nsmhandle;
230 if (atomic_read(&nsm->sm_count) == 1
231 && nsm->sm_monitored && !nsm->sm_sticky) {
232 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
234 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host->net);
238 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
241 nsm->sm_monitored = 0;
245 static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
248 struct nsm_handle *nsm;
250 list_for_each_entry(nsm, &nsm_handles, sm_link)
251 if (strlen(nsm->sm_name) == len &&
252 memcmp(nsm->sm_name, hostname, len) == 0)
257 static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
259 struct nsm_handle *nsm;
261 list_for_each_entry(nsm, &nsm_handles, sm_link)
262 if (rpc_cmp_addr(nsm_addr(nsm), sap))
267 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
269 struct nsm_handle *nsm;
271 list_for_each_entry(nsm, &nsm_handles, sm_link)
272 if (memcmp(nsm->sm_priv.data, priv->data,
273 sizeof(priv->data)) == 0)
279 * Construct a unique cookie to match this nsm_handle to this monitored
280 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
281 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
284 * The NSM protocol requires that these cookies be unique while the
285 * system is running. We prefer a stronger requirement of making them
286 * unique across reboots. If user space bugs cause a stale cookie to
287 * be sent to the kernel, it could cause the wrong host to lose its
288 * lock state if cookies were not unique across reboots.
290 * The cookies are exposed only to local user space via loopback. They
291 * do not appear on the physical network. If we want greater security
292 * for some reason, nsm_init_private() could perform a one-way hash to
293 * obscure the contents of the cookie.
295 static void nsm_init_private(struct nsm_handle *nsm)
297 u64 *p = (u64 *)&nsm->sm_priv.data;
302 ns = timespec_to_ns(&ts);
303 put_unaligned(ns, p);
304 put_unaligned((unsigned long)nsm, p + 1);
307 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
309 const char *hostname,
310 const size_t hostname_len)
312 struct nsm_handle *new;
314 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
315 if (unlikely(new == NULL))
318 atomic_set(&new->sm_count, 1);
319 new->sm_name = (char *)(new + 1);
320 memcpy(nsm_addr(new), sap, salen);
321 new->sm_addrlen = salen;
322 nsm_init_private(new);
324 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
325 sizeof(new->sm_addrbuf)) == 0)
326 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
327 "unsupported address family");
328 memcpy(new->sm_name, hostname, hostname_len);
329 new->sm_name[hostname_len] = '\0';
335 * nsm_get_handle - Find or create a cached nsm_handle
336 * @sap: pointer to socket address of handle to find
337 * @salen: length of socket address
338 * @hostname: pointer to C string containing hostname to find
339 * @hostname_len: length of C string
341 * Behavior is modulated by the global nsm_use_hostnames variable.
343 * Returns a cached nsm_handle after bumping its ref count, or
344 * returns a fresh nsm_handle if a handle that matches @sap and/or
345 * @hostname cannot be found in the handle cache. Returns NULL if
348 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
349 const size_t salen, const char *hostname,
350 const size_t hostname_len)
352 struct nsm_handle *cached, *new = NULL;
354 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
355 if (printk_ratelimit()) {
356 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
357 "in NFS lock request\n",
358 (int)hostname_len, hostname);
364 spin_lock(&nsm_lock);
366 if (nsm_use_hostnames && hostname != NULL)
367 cached = nsm_lookup_hostname(hostname, hostname_len);
369 cached = nsm_lookup_addr(sap);
371 if (cached != NULL) {
372 atomic_inc(&cached->sm_count);
373 spin_unlock(&nsm_lock);
375 dprintk("lockd: found nsm_handle for %s (%s), "
376 "cnt %d\n", cached->sm_name,
378 atomic_read(&cached->sm_count));
383 list_add(&new->sm_link, &nsm_handles);
384 spin_unlock(&nsm_lock);
385 dprintk("lockd: created nsm_handle for %s (%s)\n",
386 new->sm_name, new->sm_addrbuf);
390 spin_unlock(&nsm_lock);
392 new = nsm_create_handle(sap, salen, hostname, hostname_len);
393 if (unlikely(new == NULL))
399 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
400 * @info: pointer to NLMPROC_SM_NOTIFY arguments
402 * Returns a matching nsm_handle if found in the nsm cache. The returned
403 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
406 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
408 struct nsm_handle *cached;
410 spin_lock(&nsm_lock);
412 cached = nsm_lookup_priv(&info->priv);
413 if (unlikely(cached == NULL)) {
414 spin_unlock(&nsm_lock);
415 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
416 info->len, info->mon);
420 atomic_inc(&cached->sm_count);
421 spin_unlock(&nsm_lock);
423 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
424 cached->sm_name, cached->sm_addrbuf,
425 atomic_read(&cached->sm_count));
430 * nsm_release - Release an NSM handle
431 * @nsm: pointer to handle to be released
434 void nsm_release(struct nsm_handle *nsm)
436 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
437 list_del(&nsm->sm_link);
438 spin_unlock(&nsm_lock);
439 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
440 nsm->sm_name, nsm->sm_addrbuf);
446 * XDR functions for NSM.
448 * See http://www.opengroup.org/ for details on the Network
449 * Status Monitor wire protocol.
452 static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
454 const u32 len = strlen(string);
457 BUG_ON(len > SM_MAXSTRLEN);
458 p = xdr_reserve_space(xdr, 4 + len);
459 xdr_encode_opaque(p, string, len);
463 * "mon_name" specifies the host to be monitored.
465 static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
467 encode_nsm_string(xdr, argp->mon_name);
471 * The "my_id" argument specifies the hostname and RPC procedure
472 * to be called when the status manager receives notification
473 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
476 static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
480 encode_nsm_string(xdr, utsname()->nodename);
481 p = xdr_reserve_space(xdr, 4 + 4 + 4);
482 *p++ = cpu_to_be32(argp->prog);
483 *p++ = cpu_to_be32(argp->vers);
484 *p = cpu_to_be32(argp->proc);
488 * The "mon_id" argument specifies the non-private arguments
489 * of an NSMPROC_MON or NSMPROC_UNMON call.
491 static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
493 encode_mon_name(xdr, argp);
494 encode_my_id(xdr, argp);
498 * The "priv" argument may contain private information required
499 * by the NSMPROC_MON call. This information will be supplied in the
500 * NLMPROC_SM_NOTIFY call.
502 static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
506 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
507 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
510 static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
511 const struct nsm_args *argp)
513 encode_mon_id(xdr, argp);
514 encode_priv(xdr, argp);
517 static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
518 const struct nsm_args *argp)
520 encode_mon_id(xdr, argp);
523 static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
524 struct xdr_stream *xdr,
525 struct nsm_res *resp)
529 p = xdr_inline_decode(xdr, 4 + 4);
530 if (unlikely(p == NULL))
532 resp->status = be32_to_cpup(p++);
533 resp->state = be32_to_cpup(p);
535 dprintk("lockd: %s status %d state %d\n",
536 __func__, resp->status, resp->state);
540 static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
541 struct xdr_stream *xdr,
542 struct nsm_res *resp)
546 p = xdr_inline_decode(xdr, 4);
547 if (unlikely(p == NULL))
549 resp->state = be32_to_cpup(p);
551 dprintk("lockd: %s state %d\n", __func__, resp->state);
555 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
556 #define SM_my_id_sz (SM_my_name_sz+3)
557 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
558 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
559 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
560 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
561 #define SM_monres_sz 2
562 #define SM_unmonres_sz 1
564 static struct rpc_procinfo nsm_procedures[] = {
566 .p_proc = NSMPROC_MON,
567 .p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
568 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
569 .p_arglen = SM_mon_sz,
570 .p_replen = SM_monres_sz,
571 .p_statidx = NSMPROC_MON,
575 .p_proc = NSMPROC_UNMON,
576 .p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
577 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
578 .p_arglen = SM_mon_id_sz,
579 .p_replen = SM_unmonres_sz,
580 .p_statidx = NSMPROC_UNMON,
581 .p_name = "UNMONITOR",
585 static const struct rpc_version nsm_version1 = {
587 .nrprocs = ARRAY_SIZE(nsm_procedures),
588 .procs = nsm_procedures
591 static const struct rpc_version *nsm_version[] = {
595 static struct rpc_stat nsm_stats;
597 static const struct rpc_program nsm_program = {
599 .number = NSM_PROGRAM,
600 .nrvers = ARRAY_SIZE(nsm_version),
601 .version = nsm_version,