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>
14 #include <linux/sunrpc/clnt.h>
15 #include <linux/sunrpc/xprtsock.h>
16 #include <linux/sunrpc/svc.h>
17 #include <linux/lockd/lockd.h>
19 #define NLMDBG_FACILITY NLMDBG_MONITOR
20 #define NSM_PROGRAM 100024
34 struct nsm_private *priv;
35 u32 prog; /* RPC callback info */
47 static struct rpc_clnt * nsm_create(void);
49 static struct rpc_program nsm_program;
50 static LIST_HEAD(nsm_handles);
51 static DEFINE_SPINLOCK(nsm_lock);
56 int __read_mostly nsm_local_state;
57 int __read_mostly nsm_use_hostnames;
59 static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
61 return (struct sockaddr *)&nsm->sm_addr;
64 static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
67 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
68 snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
71 static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf,
74 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
76 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
77 snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
78 else if (sin6->sin6_scope_id != 0)
79 snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
82 snprintf(buf, len, "%pI6", &sin6->sin6_addr);
85 static void nsm_display_address(const struct sockaddr *sap,
86 char *buf, const size_t len)
88 switch (sap->sa_family) {
90 nsm_display_ipv4_address(sap, buf, len);
93 nsm_display_ipv6_address(sap, buf, len);
96 snprintf(buf, len, "unsupported address family");
102 * Common procedure for NSMPROC_MON/NSMPROC_UNMON calls
105 nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
107 struct rpc_clnt *clnt;
109 struct nsm_args args = {
110 .priv = &nsm->sm_priv,
113 .proc = NLMPROC_NSM_NOTIFY,
114 .mon_name = nsm->sm_mon_name,
116 struct rpc_message msg = {
123 status = PTR_ERR(clnt);
124 dprintk("lockd: failed to create NSM upcall transport, "
125 "status=%d\n", status);
129 memset(res, 0, sizeof(*res));
131 msg.rpc_proc = &clnt->cl_procinfo[proc];
132 status = rpc_call_sync(clnt, &msg, 0);
134 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
138 rpc_shutdown_client(clnt);
144 * nsm_monitor - Notify a peer in case we reboot
145 * @host: pointer to nlm_host of peer to notify
147 * If this peer is not already monitored, this function sends an
148 * upcall to the local rpc.statd to record the name/address of
149 * the peer to notify in case we reboot.
151 * Returns zero if the peer is monitored by the local rpc.statd;
152 * otherwise a negative errno value is returned.
154 int nsm_monitor(const struct nlm_host *host)
156 struct nsm_handle *nsm = host->h_nsmhandle;
160 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
162 if (nsm->sm_monitored)
166 * Choose whether to record the caller_name or IP address of
167 * this peer in the local rpc.statd's database.
169 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
171 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
175 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
177 nsm->sm_monitored = 1;
182 * nsm_unmonitor - Unregister peer notification
183 * @host: pointer to nlm_host of peer to stop monitoring
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
189 void nsm_unmonitor(const struct nlm_host *host)
191 struct nsm_handle *nsm = host->h_nsmhandle;
195 if (atomic_read(&nsm->sm_count) == 1
196 && nsm->sm_monitored && !nsm->sm_sticky) {
197 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
199 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
203 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
206 nsm->sm_monitored = 0;
210 static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
213 struct nsm_handle *nsm;
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)
222 static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
224 struct nsm_handle *nsm;
226 list_for_each_entry(nsm, &nsm_handles, sm_link)
227 if (nlm_cmp_addr(nsm_addr(nsm), sap))
232 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
234 struct nsm_handle *nsm;
236 list_for_each_entry(nsm, &nsm_handles, sm_link)
237 if (memcmp(nsm->sm_priv.data, priv->data,
238 sizeof(priv->data)) == 0)
244 * Construct a unique cookie to match this nsm_handle to this monitored
245 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
246 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
249 * The NSM protocol requires that these cookies be unique while the
250 * system is running. We prefer a stronger requirement of making them
251 * unique across reboots. If user space bugs cause a stale cookie to
252 * be sent to the kernel, it could cause the wrong host to lose its
253 * lock state if cookies were not unique across reboots.
255 * The cookies are exposed only to local user space via loopback. They
256 * do not appear on the physical network. If we want greater security
257 * for some reason, nsm_init_private() could perform a one-way hash to
258 * obscure the contents of the cookie.
260 static void nsm_init_private(struct nsm_handle *nsm)
262 u64 *p = (u64 *)&nsm->sm_priv.data;
266 *p++ = timespec_to_ns(&ts);
267 *p = (unsigned long)nsm;
270 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
272 const char *hostname,
273 const size_t hostname_len)
275 struct nsm_handle *new;
277 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
278 if (unlikely(new == NULL))
281 atomic_set(&new->sm_count, 1);
282 new->sm_name = (char *)(new + 1);
283 memcpy(nsm_addr(new), sap, salen);
284 new->sm_addrlen = salen;
285 nsm_init_private(new);
286 nsm_display_address((const struct sockaddr *)&new->sm_addr,
287 new->sm_addrbuf, sizeof(new->sm_addrbuf));
288 memcpy(new->sm_name, hostname, hostname_len);
289 new->sm_name[hostname_len] = '\0';
295 * nsm_get_handle - Find or create a cached nsm_handle
296 * @sap: pointer to socket address of handle to find
297 * @salen: length of socket address
298 * @hostname: pointer to C string containing hostname to find
299 * @hostname_len: length of C string
301 * Behavior is modulated by the global nsm_use_hostnames variable.
303 * Returns a cached nsm_handle after bumping its ref count, or
304 * returns a fresh nsm_handle if a handle that matches @sap and/or
305 * @hostname cannot be found in the handle cache. Returns NULL if
308 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
309 const size_t salen, const char *hostname,
310 const size_t hostname_len)
312 struct nsm_handle *cached, *new = NULL;
314 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
315 if (printk_ratelimit()) {
316 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
317 "in NFS lock request\n",
318 (int)hostname_len, hostname);
324 spin_lock(&nsm_lock);
326 if (nsm_use_hostnames && hostname != NULL)
327 cached = nsm_lookup_hostname(hostname, hostname_len);
329 cached = nsm_lookup_addr(sap);
331 if (cached != NULL) {
332 atomic_inc(&cached->sm_count);
333 spin_unlock(&nsm_lock);
335 dprintk("lockd: found nsm_handle for %s (%s), "
336 "cnt %d\n", cached->sm_name,
338 atomic_read(&cached->sm_count));
343 list_add(&new->sm_link, &nsm_handles);
344 spin_unlock(&nsm_lock);
345 dprintk("lockd: created nsm_handle for %s (%s)\n",
346 new->sm_name, new->sm_addrbuf);
350 spin_unlock(&nsm_lock);
352 new = nsm_create_handle(sap, salen, hostname, hostname_len);
353 if (unlikely(new == NULL))
359 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
360 * @info: pointer to NLMPROC_SM_NOTIFY arguments
362 * Returns a matching nsm_handle if found in the nsm cache; the returned
363 * nsm_handle's reference count is bumped and sm_monitored is cleared.
364 * Otherwise returns NULL if some error occurred.
366 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
368 struct nsm_handle *cached;
370 spin_lock(&nsm_lock);
372 cached = nsm_lookup_priv(&info->priv);
373 if (unlikely(cached == NULL)) {
374 spin_unlock(&nsm_lock);
375 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
376 info->len, info->mon);
380 atomic_inc(&cached->sm_count);
381 spin_unlock(&nsm_lock);
384 * During subsequent lock activity, force a fresh
385 * notification to be set up for this host.
387 cached->sm_monitored = 0;
389 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
390 cached->sm_name, cached->sm_addrbuf,
391 atomic_read(&cached->sm_count));
396 * nsm_release - Release an NSM handle
397 * @nsm: pointer to handle to be released
400 void nsm_release(struct nsm_handle *nsm)
402 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
403 list_del(&nsm->sm_link);
404 spin_unlock(&nsm_lock);
405 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
406 nsm->sm_name, nsm->sm_addrbuf);
412 * Create NSM client for the local host
414 static struct rpc_clnt *
417 struct sockaddr_in sin = {
418 .sin_family = AF_INET,
419 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
422 struct rpc_create_args args = {
423 .protocol = XPRT_TRANSPORT_UDP,
424 .address = (struct sockaddr *)&sin,
425 .addrsize = sizeof(sin),
426 .servername = "localhost",
427 .program = &nsm_program,
428 .version = NSM_VERSION,
429 .authflavor = RPC_AUTH_NULL,
432 return rpc_create(&args);
436 * XDR functions for NSM.
438 * See http://www.opengroup.org/ for details on the Network
439 * Status Monitor wire protocol.
442 static int encode_nsm_string(struct xdr_stream *xdr, const char *string)
444 const u32 len = strlen(string);
447 if (unlikely(len > SM_MAXSTRLEN))
449 p = xdr_reserve_space(xdr, sizeof(u32) + len);
450 if (unlikely(p == NULL))
452 xdr_encode_opaque(p, string, len);
457 * "mon_name" specifies the host to be monitored.
459 static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
461 return encode_nsm_string(xdr, argp->mon_name);
465 * The "my_id" argument specifies the hostname and RPC procedure
466 * to be called when the status manager receives notification
467 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
470 static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
475 status = encode_nsm_string(xdr, utsname()->nodename);
476 if (unlikely(status != 0))
478 p = xdr_reserve_space(xdr, 3 * sizeof(u32));
479 if (unlikely(p == NULL))
481 *p++ = htonl(argp->prog);
482 *p++ = htonl(argp->vers);
483 *p++ = htonl(argp->proc);
488 * The "mon_id" argument specifies the non-private arguments
489 * of an NSMPROC_MON or NSMPROC_UNMON call.
491 static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
495 status = encode_mon_name(xdr, argp);
496 if (unlikely(status != 0))
498 return encode_my_id(xdr, argp);
502 * The "priv" argument may contain private information required
503 * by the NSMPROC_MON call. This information will be supplied in the
504 * NLMPROC_SM_NOTIFY call.
506 static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
510 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
511 if (unlikely(p == NULL))
513 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
517 static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
518 const struct nsm_args *argp)
520 struct xdr_stream xdr;
523 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
524 status = encode_mon_id(&xdr, argp);
525 if (unlikely(status))
527 return encode_priv(&xdr, argp);
530 static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
531 const struct nsm_args *argp)
533 struct xdr_stream xdr;
535 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
536 return encode_mon_id(&xdr, argp);
539 static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
540 struct nsm_res *resp)
542 struct xdr_stream xdr;
544 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
545 p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
546 if (unlikely(p == NULL))
548 resp->status = ntohl(*p++);
549 resp->state = ntohl(*p);
551 dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
552 resp->status, resp->state);
556 static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
557 struct nsm_res *resp)
559 struct xdr_stream xdr;
561 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
562 p = xdr_inline_decode(&xdr, sizeof(u32));
563 if (unlikely(p == NULL))
565 resp->state = ntohl(*p);
567 dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
571 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
572 #define SM_my_id_sz (SM_my_name_sz+3)
573 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
574 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
575 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
576 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
577 #define SM_monres_sz 2
578 #define SM_unmonres_sz 1
580 static struct rpc_procinfo nsm_procedures[] = {
582 .p_proc = NSMPROC_MON,
583 .p_encode = (kxdrproc_t)xdr_enc_mon,
584 .p_decode = (kxdrproc_t)xdr_dec_stat_res,
585 .p_arglen = SM_mon_sz,
586 .p_replen = SM_monres_sz,
587 .p_statidx = NSMPROC_MON,
591 .p_proc = NSMPROC_UNMON,
592 .p_encode = (kxdrproc_t)xdr_enc_unmon,
593 .p_decode = (kxdrproc_t)xdr_dec_stat,
594 .p_arglen = SM_mon_id_sz,
595 .p_replen = SM_unmonres_sz,
596 .p_statidx = NSMPROC_UNMON,
597 .p_name = "UNMONITOR",
601 static struct rpc_version nsm_version1 = {
603 .nrprocs = ARRAY_SIZE(nsm_procedures),
604 .procs = nsm_procedures
607 static struct rpc_version * nsm_version[] = {
611 static struct rpc_stat nsm_stats;
613 static struct rpc_program nsm_program = {
615 .number = NSM_PROGRAM,
616 .nrvers = ARRAY_SIZE(nsm_version),
617 .version = nsm_version,