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);
58 static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
61 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
62 snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
65 static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf,
68 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
70 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
71 snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
72 else if (sin6->sin6_scope_id != 0)
73 snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
76 snprintf(buf, len, "%pI6", &sin6->sin6_addr);
79 static void nsm_display_address(const struct sockaddr *sap,
80 char *buf, const size_t len)
82 switch (sap->sa_family) {
84 nsm_display_ipv4_address(sap, buf, len);
87 nsm_display_ipv6_address(sap, buf, len);
90 snprintf(buf, len, "unsupported address family");
96 * Common procedure for NSMPROC_MON/NSMPROC_UNMON calls
99 nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
101 struct rpc_clnt *clnt;
103 struct nsm_args args = {
104 .priv = &nsm->sm_priv,
107 .proc = NLMPROC_NSM_NOTIFY,
108 .mon_name = nsm->sm_mon_name,
110 struct rpc_message msg = {
117 status = PTR_ERR(clnt);
118 dprintk("lockd: failed to create NSM upcall transport, "
119 "status=%d\n", status);
123 memset(res, 0, sizeof(*res));
125 msg.rpc_proc = &clnt->cl_procinfo[proc];
126 status = rpc_call_sync(clnt, &msg, 0);
128 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
132 rpc_shutdown_client(clnt);
138 * nsm_monitor - Notify a peer in case we reboot
139 * @host: pointer to nlm_host of peer to notify
141 * If this peer is not already monitored, this function sends an
142 * upcall to the local rpc.statd to record the name/address of
143 * the peer to notify in case we reboot.
145 * Returns zero if the peer is monitored by the local rpc.statd;
146 * otherwise a negative errno value is returned.
148 int nsm_monitor(const struct nlm_host *host)
150 struct nsm_handle *nsm = host->h_nsmhandle;
154 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
156 if (nsm->sm_monitored)
160 * Choose whether to record the caller_name or IP address of
161 * this peer in the local rpc.statd's database.
163 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
165 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
169 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
171 nsm->sm_monitored = 1;
176 * nsm_unmonitor - Unregister peer notification
177 * @host: pointer to nlm_host of peer to stop monitoring
179 * If this peer is monitored, this function sends an upcall to
180 * tell the local rpc.statd not to send this peer a notification
183 void nsm_unmonitor(const struct nlm_host *host)
185 struct nsm_handle *nsm = host->h_nsmhandle;
189 if (atomic_read(&nsm->sm_count) == 1
190 && nsm->sm_monitored && !nsm->sm_sticky) {
191 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
193 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
197 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
200 nsm->sm_monitored = 0;
204 static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
207 struct nsm_handle *nsm;
209 list_for_each_entry(nsm, &nsm_handles, sm_link)
210 if (strlen(nsm->sm_name) == len &&
211 memcmp(nsm->sm_name, hostname, len) == 0)
216 static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
218 struct nsm_handle *nsm;
220 list_for_each_entry(nsm, &nsm_handles, sm_link)
221 if (nlm_cmp_addr(nsm_addr(nsm), sap))
226 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
228 struct nsm_handle *nsm;
230 list_for_each_entry(nsm, &nsm_handles, sm_link)
231 if (memcmp(nsm->sm_priv.data, priv->data,
232 sizeof(priv->data)) == 0)
238 * Construct a unique cookie to match this nsm_handle to this monitored
239 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
240 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
243 * The NSM protocol requires that these cookies be unique while the
244 * system is running. We prefer a stronger requirement of making them
245 * unique across reboots. If user space bugs cause a stale cookie to
246 * be sent to the kernel, it could cause the wrong host to lose its
247 * lock state if cookies were not unique across reboots.
249 * The cookies are exposed only to local user space via loopback. They
250 * do not appear on the physical network. If we want greater security
251 * for some reason, nsm_init_private() could perform a one-way hash to
252 * obscure the contents of the cookie.
254 static void nsm_init_private(struct nsm_handle *nsm)
256 u64 *p = (u64 *)&nsm->sm_priv.data;
260 *p++ = timespec_to_ns(&ts);
261 *p = (unsigned long)nsm;
264 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
266 const char *hostname,
267 const size_t hostname_len)
269 struct nsm_handle *new;
271 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
272 if (unlikely(new == NULL))
275 atomic_set(&new->sm_count, 1);
276 new->sm_name = (char *)(new + 1);
277 memcpy(nsm_addr(new), sap, salen);
278 new->sm_addrlen = salen;
279 nsm_init_private(new);
280 nsm_display_address((const struct sockaddr *)&new->sm_addr,
281 new->sm_addrbuf, sizeof(new->sm_addrbuf));
282 memcpy(new->sm_name, hostname, hostname_len);
283 new->sm_name[hostname_len] = '\0';
289 * nsm_get_handle - Find or create a cached nsm_handle
290 * @sap: pointer to socket address of handle to find
291 * @salen: length of socket address
292 * @hostname: pointer to C string containing hostname to find
293 * @hostname_len: length of C string
295 * Behavior is modulated by the global nsm_use_hostnames variable.
297 * Returns a cached nsm_handle after bumping its ref count, or
298 * returns a fresh nsm_handle if a handle that matches @sap and/or
299 * @hostname cannot be found in the handle cache. Returns NULL if
302 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
303 const size_t salen, const char *hostname,
304 const size_t hostname_len)
306 struct nsm_handle *cached, *new = NULL;
308 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
309 if (printk_ratelimit()) {
310 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
311 "in NFS lock request\n",
312 (int)hostname_len, hostname);
318 spin_lock(&nsm_lock);
320 if (nsm_use_hostnames && hostname != NULL)
321 cached = nsm_lookup_hostname(hostname, hostname_len);
323 cached = nsm_lookup_addr(sap);
325 if (cached != NULL) {
326 atomic_inc(&cached->sm_count);
327 spin_unlock(&nsm_lock);
329 dprintk("lockd: found nsm_handle for %s (%s), "
330 "cnt %d\n", cached->sm_name,
332 atomic_read(&cached->sm_count));
337 list_add(&new->sm_link, &nsm_handles);
338 spin_unlock(&nsm_lock);
339 dprintk("lockd: created nsm_handle for %s (%s)\n",
340 new->sm_name, new->sm_addrbuf);
344 spin_unlock(&nsm_lock);
346 new = nsm_create_handle(sap, salen, hostname, hostname_len);
347 if (unlikely(new == NULL))
353 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
354 * @info: pointer to NLMPROC_SM_NOTIFY arguments
356 * Returns a matching nsm_handle if found in the nsm cache; the returned
357 * nsm_handle's reference count is bumped and sm_monitored is cleared.
358 * Otherwise returns NULL if some error occurred.
360 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
362 struct nsm_handle *cached;
364 spin_lock(&nsm_lock);
366 cached = nsm_lookup_priv(&info->priv);
367 if (unlikely(cached == NULL)) {
368 spin_unlock(&nsm_lock);
369 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
370 info->len, info->mon);
374 atomic_inc(&cached->sm_count);
375 spin_unlock(&nsm_lock);
378 * During subsequent lock activity, force a fresh
379 * notification to be set up for this host.
381 cached->sm_monitored = 0;
383 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
384 cached->sm_name, cached->sm_addrbuf,
385 atomic_read(&cached->sm_count));
390 * nsm_release - Release an NSM handle
391 * @nsm: pointer to handle to be released
394 void nsm_release(struct nsm_handle *nsm)
396 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
397 list_del(&nsm->sm_link);
398 spin_unlock(&nsm_lock);
399 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
400 nsm->sm_name, nsm->sm_addrbuf);
406 * Create NSM client for the local host
408 static struct rpc_clnt *
411 struct sockaddr_in sin = {
412 .sin_family = AF_INET,
413 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
416 struct rpc_create_args args = {
417 .protocol = XPRT_TRANSPORT_UDP,
418 .address = (struct sockaddr *)&sin,
419 .addrsize = sizeof(sin),
420 .servername = "localhost",
421 .program = &nsm_program,
422 .version = NSM_VERSION,
423 .authflavor = RPC_AUTH_NULL,
426 return rpc_create(&args);
430 * XDR functions for NSM.
432 * See http://www.opengroup.org/ for details on the Network
433 * Status Monitor wire protocol.
436 static int encode_nsm_string(struct xdr_stream *xdr, const char *string)
438 const u32 len = strlen(string);
441 if (unlikely(len > SM_MAXSTRLEN))
443 p = xdr_reserve_space(xdr, sizeof(u32) + len);
444 if (unlikely(p == NULL))
446 xdr_encode_opaque(p, string, len);
451 * "mon_name" specifies the host to be monitored.
453 static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
455 return encode_nsm_string(xdr, argp->mon_name);
459 * The "my_id" argument specifies the hostname and RPC procedure
460 * to be called when the status manager receives notification
461 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
464 static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
469 status = encode_nsm_string(xdr, utsname()->nodename);
470 if (unlikely(status != 0))
472 p = xdr_reserve_space(xdr, 3 * sizeof(u32));
473 if (unlikely(p == NULL))
475 *p++ = htonl(argp->prog);
476 *p++ = htonl(argp->vers);
477 *p++ = htonl(argp->proc);
482 * The "mon_id" argument specifies the non-private arguments
483 * of an NSMPROC_MON or NSMPROC_UNMON call.
485 static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
489 status = encode_mon_name(xdr, argp);
490 if (unlikely(status != 0))
492 return encode_my_id(xdr, argp);
496 * The "priv" argument may contain private information required
497 * by the NSMPROC_MON call. This information will be supplied in the
498 * NLMPROC_SM_NOTIFY call.
500 static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
504 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
505 if (unlikely(p == NULL))
507 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
511 static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
512 const struct nsm_args *argp)
514 struct xdr_stream xdr;
517 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
518 status = encode_mon_id(&xdr, argp);
519 if (unlikely(status))
521 return encode_priv(&xdr, argp);
524 static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
525 const struct nsm_args *argp)
527 struct xdr_stream xdr;
529 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
530 return encode_mon_id(&xdr, argp);
533 static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
534 struct nsm_res *resp)
536 struct xdr_stream xdr;
538 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
539 p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
540 if (unlikely(p == NULL))
542 resp->status = ntohl(*p++);
543 resp->state = ntohl(*p);
545 dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
546 resp->status, resp->state);
550 static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
551 struct nsm_res *resp)
553 struct xdr_stream xdr;
555 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
556 p = xdr_inline_decode(&xdr, sizeof(u32));
557 if (unlikely(p == NULL))
559 resp->state = ntohl(*p);
561 dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
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
574 static struct rpc_procinfo nsm_procedures[] = {
576 .p_proc = NSMPROC_MON,
577 .p_encode = (kxdrproc_t)xdr_enc_mon,
578 .p_decode = (kxdrproc_t)xdr_dec_stat_res,
579 .p_arglen = SM_mon_sz,
580 .p_replen = SM_monres_sz,
581 .p_statidx = NSMPROC_MON,
585 .p_proc = NSMPROC_UNMON,
586 .p_encode = (kxdrproc_t)xdr_enc_unmon,
587 .p_decode = (kxdrproc_t)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",
595 static struct rpc_version nsm_version1 = {
597 .nrprocs = ARRAY_SIZE(nsm_procedures),
598 .procs = nsm_procedures
601 static struct rpc_version * nsm_version[] = {
605 static struct rpc_stat nsm_stats;
607 static struct rpc_program nsm_program = {
609 .number = NSM_PROGRAM,
610 .nrvers = ARRAY_SIZE(nsm_version),
611 .version = nsm_version,