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>
22 #define NLMDBG_FACILITY NLMDBG_MONITOR
23 #define NSM_PROGRAM 100024
37 struct nsm_private *priv;
38 u32 prog; /* RPC callback info */
50 static struct rpc_program nsm_program;
51 static LIST_HEAD(nsm_handles);
52 static DEFINE_SPINLOCK(nsm_lock);
57 u32 __read_mostly nsm_local_state;
58 int __read_mostly nsm_use_hostnames;
60 static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
62 return (struct sockaddr *)&nsm->sm_addr;
65 static struct rpc_clnt *nsm_create(void)
67 struct sockaddr_in sin = {
68 .sin_family = AF_INET,
69 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
71 struct rpc_create_args args = {
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,
83 return rpc_create(&args);
86 static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
88 struct rpc_clnt *clnt;
90 struct nsm_args args = {
91 .priv = &nsm->sm_priv,
94 .proc = NLMPROC_NSM_NOTIFY,
95 .mon_name = nsm->sm_mon_name,
97 struct rpc_message msg = {
104 status = PTR_ERR(clnt);
105 dprintk("lockd: failed to create NSM upcall transport, "
106 "status=%d\n", status);
110 memset(res, 0, sizeof(*res));
112 msg.rpc_proc = &clnt->cl_procinfo[proc];
113 status = rpc_call_sync(clnt, &msg, 0);
114 if (status == -ECONNREFUSED) {
115 dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
117 rpc_force_rebind(clnt);
118 status = rpc_call_sync(clnt, &msg, 0);
121 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
125 rpc_shutdown_client(clnt);
131 * nsm_monitor - Notify a peer in case we reboot
132 * @host: pointer to nlm_host of peer to notify
134 * If this peer is not already monitored, this function sends an
135 * upcall to the local rpc.statd to record the name/address of
136 * the peer to notify in case we reboot.
138 * Returns zero if the peer is monitored by the local rpc.statd;
139 * otherwise a negative errno value is returned.
141 int nsm_monitor(const struct nlm_host *host)
143 struct nsm_handle *nsm = host->h_nsmhandle;
147 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
149 if (nsm->sm_monitored)
153 * Choose whether to record the caller_name or IP address of
154 * this peer in the local rpc.statd's database.
156 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
158 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
159 if (unlikely(res.status != 0))
161 if (unlikely(status < 0)) {
162 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
166 nsm->sm_monitored = 1;
167 if (unlikely(nsm_local_state != res.state)) {
168 nsm_local_state = res.state;
169 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
175 * nsm_unmonitor - Unregister peer notification
176 * @host: pointer to nlm_host of peer to stop monitoring
178 * If this peer is monitored, this function sends an upcall to
179 * tell the local rpc.statd not to send this peer a notification
182 void nsm_unmonitor(const struct nlm_host *host)
184 struct nsm_handle *nsm = host->h_nsmhandle;
188 if (atomic_read(&nsm->sm_count) == 1
189 && nsm->sm_monitored && !nsm->sm_sticky) {
190 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
192 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
196 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
199 nsm->sm_monitored = 0;
203 static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
206 struct nsm_handle *nsm;
208 list_for_each_entry(nsm, &nsm_handles, sm_link)
209 if (strlen(nsm->sm_name) == len &&
210 memcmp(nsm->sm_name, hostname, len) == 0)
215 static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
217 struct nsm_handle *nsm;
219 list_for_each_entry(nsm, &nsm_handles, sm_link)
220 if (rpc_cmp_addr(nsm_addr(nsm), sap))
225 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
227 struct nsm_handle *nsm;
229 list_for_each_entry(nsm, &nsm_handles, sm_link)
230 if (memcmp(nsm->sm_priv.data, priv->data,
231 sizeof(priv->data)) == 0)
237 * Construct a unique cookie to match this nsm_handle to this monitored
238 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
239 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
242 * The NSM protocol requires that these cookies be unique while the
243 * system is running. We prefer a stronger requirement of making them
244 * unique across reboots. If user space bugs cause a stale cookie to
245 * be sent to the kernel, it could cause the wrong host to lose its
246 * lock state if cookies were not unique across reboots.
248 * The cookies are exposed only to local user space via loopback. They
249 * do not appear on the physical network. If we want greater security
250 * for some reason, nsm_init_private() could perform a one-way hash to
251 * obscure the contents of the cookie.
253 static void nsm_init_private(struct nsm_handle *nsm)
255 u64 *p = (u64 *)&nsm->sm_priv.data;
260 ns = timespec_to_ns(&ts);
261 put_unaligned(ns, p);
262 put_unaligned((unsigned long)nsm, p + 1);
265 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
267 const char *hostname,
268 const size_t hostname_len)
270 struct nsm_handle *new;
272 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
273 if (unlikely(new == NULL))
276 atomic_set(&new->sm_count, 1);
277 new->sm_name = (char *)(new + 1);
278 memcpy(nsm_addr(new), sap, salen);
279 new->sm_addrlen = salen;
280 nsm_init_private(new);
282 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
283 sizeof(new->sm_addrbuf)) == 0)
284 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
285 "unsupported address family");
286 memcpy(new->sm_name, hostname, hostname_len);
287 new->sm_name[hostname_len] = '\0';
293 * nsm_get_handle - Find or create a cached nsm_handle
294 * @sap: pointer to socket address of handle to find
295 * @salen: length of socket address
296 * @hostname: pointer to C string containing hostname to find
297 * @hostname_len: length of C string
299 * Behavior is modulated by the global nsm_use_hostnames variable.
301 * Returns a cached nsm_handle after bumping its ref count, or
302 * returns a fresh nsm_handle if a handle that matches @sap and/or
303 * @hostname cannot be found in the handle cache. Returns NULL if
306 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
307 const size_t salen, const char *hostname,
308 const size_t hostname_len)
310 struct nsm_handle *cached, *new = NULL;
312 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
313 if (printk_ratelimit()) {
314 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
315 "in NFS lock request\n",
316 (int)hostname_len, hostname);
322 spin_lock(&nsm_lock);
324 if (nsm_use_hostnames && hostname != NULL)
325 cached = nsm_lookup_hostname(hostname, hostname_len);
327 cached = nsm_lookup_addr(sap);
329 if (cached != NULL) {
330 atomic_inc(&cached->sm_count);
331 spin_unlock(&nsm_lock);
333 dprintk("lockd: found nsm_handle for %s (%s), "
334 "cnt %d\n", cached->sm_name,
336 atomic_read(&cached->sm_count));
341 list_add(&new->sm_link, &nsm_handles);
342 spin_unlock(&nsm_lock);
343 dprintk("lockd: created nsm_handle for %s (%s)\n",
344 new->sm_name, new->sm_addrbuf);
348 spin_unlock(&nsm_lock);
350 new = nsm_create_handle(sap, salen, hostname, hostname_len);
351 if (unlikely(new == NULL))
357 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
358 * @info: pointer to NLMPROC_SM_NOTIFY arguments
360 * Returns a matching nsm_handle if found in the nsm cache. The returned
361 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
364 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
366 struct nsm_handle *cached;
368 spin_lock(&nsm_lock);
370 cached = nsm_lookup_priv(&info->priv);
371 if (unlikely(cached == NULL)) {
372 spin_unlock(&nsm_lock);
373 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
374 info->len, info->mon);
378 atomic_inc(&cached->sm_count);
379 spin_unlock(&nsm_lock);
381 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
382 cached->sm_name, cached->sm_addrbuf,
383 atomic_read(&cached->sm_count));
388 * nsm_release - Release an NSM handle
389 * @nsm: pointer to handle to be released
392 void nsm_release(struct nsm_handle *nsm)
394 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
395 list_del(&nsm->sm_link);
396 spin_unlock(&nsm_lock);
397 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
398 nsm->sm_name, nsm->sm_addrbuf);
404 * XDR functions for NSM.
406 * See http://www.opengroup.org/ for details on the Network
407 * Status Monitor wire protocol.
410 static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
412 const u32 len = strlen(string);
415 BUG_ON(len > SM_MAXSTRLEN);
416 p = xdr_reserve_space(xdr, 4 + len);
417 xdr_encode_opaque(p, string, len);
421 * "mon_name" specifies the host to be monitored.
423 static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
425 encode_nsm_string(xdr, argp->mon_name);
429 * The "my_id" argument specifies the hostname and RPC procedure
430 * to be called when the status manager receives notification
431 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
434 static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
438 encode_nsm_string(xdr, utsname()->nodename);
439 p = xdr_reserve_space(xdr, 4 + 4 + 4);
440 *p++ = cpu_to_be32(argp->prog);
441 *p++ = cpu_to_be32(argp->vers);
442 *p = cpu_to_be32(argp->proc);
446 * The "mon_id" argument specifies the non-private arguments
447 * of an NSMPROC_MON or NSMPROC_UNMON call.
449 static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
451 encode_mon_name(xdr, argp);
452 encode_my_id(xdr, argp);
456 * The "priv" argument may contain private information required
457 * by the NSMPROC_MON call. This information will be supplied in the
458 * NLMPROC_SM_NOTIFY call.
460 static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
464 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
465 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
468 static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
469 const struct nsm_args *argp)
471 encode_mon_id(xdr, argp);
472 encode_priv(xdr, argp);
475 static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
476 const struct nsm_args *argp)
478 encode_mon_id(xdr, argp);
481 static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
482 struct xdr_stream *xdr,
483 struct nsm_res *resp)
487 p = xdr_inline_decode(xdr, 4 + 4);
488 if (unlikely(p == NULL))
490 resp->status = be32_to_cpup(p++);
491 resp->state = be32_to_cpup(p);
493 dprintk("lockd: %s status %d state %d\n",
494 __func__, resp->status, resp->state);
498 static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
499 struct xdr_stream *xdr,
500 struct nsm_res *resp)
504 p = xdr_inline_decode(xdr, 4);
505 if (unlikely(p == NULL))
507 resp->state = be32_to_cpup(p);
509 dprintk("lockd: %s state %d\n", __func__, resp->state);
513 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
514 #define SM_my_id_sz (SM_my_name_sz+3)
515 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
516 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
517 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
518 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
519 #define SM_monres_sz 2
520 #define SM_unmonres_sz 1
522 static struct rpc_procinfo nsm_procedures[] = {
524 .p_proc = NSMPROC_MON,
525 .p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
526 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
527 .p_arglen = SM_mon_sz,
528 .p_replen = SM_monres_sz,
529 .p_statidx = NSMPROC_MON,
533 .p_proc = NSMPROC_UNMON,
534 .p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
535 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
536 .p_arglen = SM_mon_id_sz,
537 .p_replen = SM_unmonres_sz,
538 .p_statidx = NSMPROC_UNMON,
539 .p_name = "UNMONITOR",
543 static struct rpc_version nsm_version1 = {
545 .nrprocs = ARRAY_SIZE(nsm_procedures),
546 .procs = nsm_procedures
549 static struct rpc_version * nsm_version[] = {
553 static struct rpc_stat nsm_stats;
555 static struct rpc_program nsm_program = {
557 .number = NSM_PROGRAM,
558 .nrvers = ARRAY_SIZE(nsm_version),
559 .version = nsm_version,