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 */
53 static const struct rpc_program nsm_program;
54 static LIST_HEAD(nsm_handles);
55 static DEFINE_SPINLOCK(nsm_lock);
60 u32 __read_mostly nsm_local_state;
61 bool __read_mostly nsm_use_hostnames;
63 static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
65 return (struct sockaddr *)&nsm->sm_addr;
68 static struct rpc_clnt *nsm_create(struct net *net)
70 struct sockaddr_in sin = {
71 .sin_family = AF_INET,
72 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
74 struct rpc_create_args args = {
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,
86 return rpc_create(&args);
89 __maybe_unused static struct rpc_clnt *nsm_client_get(struct net *net)
91 static DEFINE_MUTEX(nsm_create_mutex);
92 struct rpc_clnt *clnt;
93 struct lockd_net *ln = net_generic(net, lockd_net_id);
95 spin_lock(&ln->nsm_clnt_lock);
99 spin_unlock(&ln->nsm_clnt_lock);
102 spin_unlock(&ln->nsm_clnt_lock);
104 mutex_lock(&nsm_create_mutex);
105 clnt = nsm_create(net);
111 mutex_unlock(&nsm_create_mutex);
116 __maybe_unused static void nsm_client_put(struct net *net)
118 struct lockd_net *ln = net_generic(net, lockd_net_id);
119 struct rpc_clnt *clnt = ln->nsm_clnt;
122 spin_lock(&ln->nsm_clnt_lock);
126 shutdown = !ln->nsm_users;
128 spin_unlock(&ln->nsm_clnt_lock);
131 rpc_shutdown_client(clnt);
134 static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
137 struct rpc_clnt *clnt;
139 struct nsm_args args = {
140 .priv = &nsm->sm_priv,
143 .proc = NLMPROC_NSM_NOTIFY,
144 .mon_name = nsm->sm_mon_name,
145 .nodename = utsname()->nodename,
147 struct rpc_message msg = {
152 clnt = nsm_create(net);
154 status = PTR_ERR(clnt);
155 dprintk("lockd: failed to create NSM upcall transport, "
156 "status=%d\n", status);
160 memset(res, 0, sizeof(*res));
162 msg.rpc_proc = &clnt->cl_procinfo[proc];
163 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
165 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
169 rpc_shutdown_client(clnt);
175 * nsm_monitor - Notify a peer in case we reboot
176 * @host: pointer to nlm_host of peer to notify
178 * If this peer is not already monitored, this function sends an
179 * upcall to the local rpc.statd to record the name/address of
180 * the peer to notify in case we reboot.
182 * Returns zero if the peer is monitored by the local rpc.statd;
183 * otherwise a negative errno value is returned.
185 int nsm_monitor(const struct nlm_host *host)
187 struct nsm_handle *nsm = host->h_nsmhandle;
191 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
193 if (nsm->sm_monitored)
197 * Choose whether to record the caller_name or IP address of
198 * this peer in the local rpc.statd's database.
200 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
202 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host->net);
203 if (unlikely(res.status != 0))
205 if (unlikely(status < 0)) {
206 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
210 nsm->sm_monitored = 1;
211 if (unlikely(nsm_local_state != res.state)) {
212 nsm_local_state = res.state;
213 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
219 * nsm_unmonitor - Unregister peer notification
220 * @host: pointer to nlm_host of peer to stop monitoring
222 * If this peer is monitored, this function sends an upcall to
223 * tell the local rpc.statd not to send this peer a notification
226 void nsm_unmonitor(const struct nlm_host *host)
228 struct nsm_handle *nsm = host->h_nsmhandle;
232 if (atomic_read(&nsm->sm_count) == 1
233 && nsm->sm_monitored && !nsm->sm_sticky) {
234 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
236 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host->net);
240 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
243 nsm->sm_monitored = 0;
247 static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
250 struct nsm_handle *nsm;
252 list_for_each_entry(nsm, &nsm_handles, sm_link)
253 if (strlen(nsm->sm_name) == len &&
254 memcmp(nsm->sm_name, hostname, len) == 0)
259 static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
261 struct nsm_handle *nsm;
263 list_for_each_entry(nsm, &nsm_handles, sm_link)
264 if (rpc_cmp_addr(nsm_addr(nsm), sap))
269 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
271 struct nsm_handle *nsm;
273 list_for_each_entry(nsm, &nsm_handles, sm_link)
274 if (memcmp(nsm->sm_priv.data, priv->data,
275 sizeof(priv->data)) == 0)
281 * Construct a unique cookie to match this nsm_handle to this monitored
282 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
283 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
286 * The NSM protocol requires that these cookies be unique while the
287 * system is running. We prefer a stronger requirement of making them
288 * unique across reboots. If user space bugs cause a stale cookie to
289 * be sent to the kernel, it could cause the wrong host to lose its
290 * lock state if cookies were not unique across reboots.
292 * The cookies are exposed only to local user space via loopback. They
293 * do not appear on the physical network. If we want greater security
294 * for some reason, nsm_init_private() could perform a one-way hash to
295 * obscure the contents of the cookie.
297 static void nsm_init_private(struct nsm_handle *nsm)
299 u64 *p = (u64 *)&nsm->sm_priv.data;
304 ns = timespec_to_ns(&ts);
305 put_unaligned(ns, p);
306 put_unaligned((unsigned long)nsm, p + 1);
309 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
311 const char *hostname,
312 const size_t hostname_len)
314 struct nsm_handle *new;
316 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
317 if (unlikely(new == NULL))
320 atomic_set(&new->sm_count, 1);
321 new->sm_name = (char *)(new + 1);
322 memcpy(nsm_addr(new), sap, salen);
323 new->sm_addrlen = salen;
324 nsm_init_private(new);
326 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
327 sizeof(new->sm_addrbuf)) == 0)
328 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
329 "unsupported address family");
330 memcpy(new->sm_name, hostname, hostname_len);
331 new->sm_name[hostname_len] = '\0';
337 * nsm_get_handle - Find or create a cached nsm_handle
338 * @sap: pointer to socket address of handle to find
339 * @salen: length of socket address
340 * @hostname: pointer to C string containing hostname to find
341 * @hostname_len: length of C string
343 * Behavior is modulated by the global nsm_use_hostnames variable.
345 * Returns a cached nsm_handle after bumping its ref count, or
346 * returns a fresh nsm_handle if a handle that matches @sap and/or
347 * @hostname cannot be found in the handle cache. Returns NULL if
350 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
351 const size_t salen, const char *hostname,
352 const size_t hostname_len)
354 struct nsm_handle *cached, *new = NULL;
356 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
357 if (printk_ratelimit()) {
358 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
359 "in NFS lock request\n",
360 (int)hostname_len, hostname);
366 spin_lock(&nsm_lock);
368 if (nsm_use_hostnames && hostname != NULL)
369 cached = nsm_lookup_hostname(hostname, hostname_len);
371 cached = nsm_lookup_addr(sap);
373 if (cached != NULL) {
374 atomic_inc(&cached->sm_count);
375 spin_unlock(&nsm_lock);
377 dprintk("lockd: found nsm_handle for %s (%s), "
378 "cnt %d\n", cached->sm_name,
380 atomic_read(&cached->sm_count));
385 list_add(&new->sm_link, &nsm_handles);
386 spin_unlock(&nsm_lock);
387 dprintk("lockd: created nsm_handle for %s (%s)\n",
388 new->sm_name, new->sm_addrbuf);
392 spin_unlock(&nsm_lock);
394 new = nsm_create_handle(sap, salen, hostname, hostname_len);
395 if (unlikely(new == NULL))
401 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
402 * @info: pointer to NLMPROC_SM_NOTIFY arguments
404 * Returns a matching nsm_handle if found in the nsm cache. The returned
405 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
408 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
410 struct nsm_handle *cached;
412 spin_lock(&nsm_lock);
414 cached = nsm_lookup_priv(&info->priv);
415 if (unlikely(cached == NULL)) {
416 spin_unlock(&nsm_lock);
417 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
418 info->len, info->mon);
422 atomic_inc(&cached->sm_count);
423 spin_unlock(&nsm_lock);
425 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
426 cached->sm_name, cached->sm_addrbuf,
427 atomic_read(&cached->sm_count));
432 * nsm_release - Release an NSM handle
433 * @nsm: pointer to handle to be released
436 void nsm_release(struct nsm_handle *nsm)
438 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
439 list_del(&nsm->sm_link);
440 spin_unlock(&nsm_lock);
441 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
442 nsm->sm_name, nsm->sm_addrbuf);
448 * XDR functions for NSM.
450 * See http://www.opengroup.org/ for details on the Network
451 * Status Monitor wire protocol.
454 static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
456 const u32 len = strlen(string);
459 BUG_ON(len > SM_MAXSTRLEN);
460 p = xdr_reserve_space(xdr, 4 + len);
461 xdr_encode_opaque(p, string, len);
465 * "mon_name" specifies the host to be monitored.
467 static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
469 encode_nsm_string(xdr, argp->mon_name);
473 * The "my_id" argument specifies the hostname and RPC procedure
474 * to be called when the status manager receives notification
475 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
478 static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
482 encode_nsm_string(xdr, argp->nodename);
483 p = xdr_reserve_space(xdr, 4 + 4 + 4);
484 *p++ = cpu_to_be32(argp->prog);
485 *p++ = cpu_to_be32(argp->vers);
486 *p = cpu_to_be32(argp->proc);
490 * The "mon_id" argument specifies the non-private arguments
491 * of an NSMPROC_MON or NSMPROC_UNMON call.
493 static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
495 encode_mon_name(xdr, argp);
496 encode_my_id(xdr, argp);
500 * The "priv" argument may contain private information required
501 * by the NSMPROC_MON call. This information will be supplied in the
502 * NLMPROC_SM_NOTIFY call.
504 static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
508 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
509 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
512 static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
513 const struct nsm_args *argp)
515 encode_mon_id(xdr, argp);
516 encode_priv(xdr, argp);
519 static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
520 const struct nsm_args *argp)
522 encode_mon_id(xdr, argp);
525 static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
526 struct xdr_stream *xdr,
527 struct nsm_res *resp)
531 p = xdr_inline_decode(xdr, 4 + 4);
532 if (unlikely(p == NULL))
534 resp->status = be32_to_cpup(p++);
535 resp->state = be32_to_cpup(p);
537 dprintk("lockd: %s status %d state %d\n",
538 __func__, resp->status, resp->state);
542 static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
543 struct xdr_stream *xdr,
544 struct nsm_res *resp)
548 p = xdr_inline_decode(xdr, 4);
549 if (unlikely(p == NULL))
551 resp->state = be32_to_cpup(p);
553 dprintk("lockd: %s state %d\n", __func__, resp->state);
557 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
558 #define SM_my_id_sz (SM_my_name_sz+3)
559 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
560 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
561 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
562 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
563 #define SM_monres_sz 2
564 #define SM_unmonres_sz 1
566 static struct rpc_procinfo nsm_procedures[] = {
568 .p_proc = NSMPROC_MON,
569 .p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
570 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
571 .p_arglen = SM_mon_sz,
572 .p_replen = SM_monres_sz,
573 .p_statidx = NSMPROC_MON,
577 .p_proc = NSMPROC_UNMON,
578 .p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
579 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
580 .p_arglen = SM_mon_id_sz,
581 .p_replen = SM_unmonres_sz,
582 .p_statidx = NSMPROC_UNMON,
583 .p_name = "UNMONITOR",
587 static const struct rpc_version nsm_version1 = {
589 .nrprocs = ARRAY_SIZE(nsm_procedures),
590 .procs = nsm_procedures
593 static const struct rpc_version *nsm_version[] = {
597 static struct rpc_stat nsm_stats;
599 static const struct rpc_program nsm_program = {
601 .number = NSM_PROGRAM,
602 .nrvers = ARRAY_SIZE(nsm_version),
603 .version = nsm_version,