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TOMOYO Linux Cross Reference
Linux/net/sunrpc/clnt.c

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  1 /*
  2  *  linux/net/sunrpc/clnt.c
  3  *
  4  *  This file contains the high-level RPC interface.
  5  *  It is modeled as a finite state machine to support both synchronous
  6  *  and asynchronous requests.
  7  *
  8  *  -   RPC header generation and argument serialization.
  9  *  -   Credential refresh.
 10  *  -   TCP connect handling.
 11  *  -   Retry of operation when it is suspected the operation failed because
 12  *      of uid squashing on the server, or when the credentials were stale
 13  *      and need to be refreshed, or when a packet was damaged in transit.
 14  *      This may be have to be moved to the VFS layer.
 15  *
 16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
 17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
 18  */
 19 
 20 
 21 #include <linux/module.h>
 22 #include <linux/types.h>
 23 #include <linux/kallsyms.h>
 24 #include <linux/mm.h>
 25 #include <linux/namei.h>
 26 #include <linux/mount.h>
 27 #include <linux/slab.h>
 28 #include <linux/rcupdate.h>
 29 #include <linux/utsname.h>
 30 #include <linux/workqueue.h>
 31 #include <linux/in.h>
 32 #include <linux/in6.h>
 33 #include <linux/un.h>
 34 
 35 #include <linux/sunrpc/clnt.h>
 36 #include <linux/sunrpc/addr.h>
 37 #include <linux/sunrpc/rpc_pipe_fs.h>
 38 #include <linux/sunrpc/metrics.h>
 39 #include <linux/sunrpc/bc_xprt.h>
 40 #include <trace/events/sunrpc.h>
 41 
 42 #include "sunrpc.h"
 43 #include "netns.h"
 44 
 45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 46 # define RPCDBG_FACILITY        RPCDBG_CALL
 47 #endif
 48 
 49 #define dprint_status(t)                                        \
 50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
 51                         __func__, t->tk_status)
 52 
 53 /*
 54  * All RPC clients are linked into this list
 55  */
 56 
 57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
 58 
 59 
 60 static void     call_start(struct rpc_task *task);
 61 static void     call_reserve(struct rpc_task *task);
 62 static void     call_reserveresult(struct rpc_task *task);
 63 static void     call_allocate(struct rpc_task *task);
 64 static void     call_decode(struct rpc_task *task);
 65 static void     call_bind(struct rpc_task *task);
 66 static void     call_bind_status(struct rpc_task *task);
 67 static void     call_transmit(struct rpc_task *task);
 68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 69 static void     call_bc_transmit(struct rpc_task *task);
 70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 71 static void     call_status(struct rpc_task *task);
 72 static void     call_transmit_status(struct rpc_task *task);
 73 static void     call_refresh(struct rpc_task *task);
 74 static void     call_refreshresult(struct rpc_task *task);
 75 static void     call_timeout(struct rpc_task *task);
 76 static void     call_connect(struct rpc_task *task);
 77 static void     call_connect_status(struct rpc_task *task);
 78 
 79 static __be32   *rpc_encode_header(struct rpc_task *task);
 80 static __be32   *rpc_verify_header(struct rpc_task *task);
 81 static int      rpc_ping(struct rpc_clnt *clnt);
 82 
 83 static void rpc_register_client(struct rpc_clnt *clnt)
 84 {
 85         struct net *net = rpc_net_ns(clnt);
 86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 87 
 88         spin_lock(&sn->rpc_client_lock);
 89         list_add(&clnt->cl_clients, &sn->all_clients);
 90         spin_unlock(&sn->rpc_client_lock);
 91 }
 92 
 93 static void rpc_unregister_client(struct rpc_clnt *clnt)
 94 {
 95         struct net *net = rpc_net_ns(clnt);
 96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 97 
 98         spin_lock(&sn->rpc_client_lock);
 99         list_del(&clnt->cl_clients);
100         spin_unlock(&sn->rpc_client_lock);
101 }
102 
103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105         rpc_remove_client_dir(clnt);
106 }
107 
108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
109 {
110         struct net *net = rpc_net_ns(clnt);
111         struct super_block *pipefs_sb;
112 
113         pipefs_sb = rpc_get_sb_net(net);
114         if (pipefs_sb) {
115                 __rpc_clnt_remove_pipedir(clnt);
116                 rpc_put_sb_net(net);
117         }
118 }
119 
120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
121                                     struct rpc_clnt *clnt)
122 {
123         static uint32_t clntid;
124         const char *dir_name = clnt->cl_program->pipe_dir_name;
125         char name[15];
126         struct dentry *dir, *dentry;
127 
128         dir = rpc_d_lookup_sb(sb, dir_name);
129         if (dir == NULL) {
130                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
131                 return dir;
132         }
133         for (;;) {
134                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
135                 name[sizeof(name) - 1] = '\0';
136                 dentry = rpc_create_client_dir(dir, name, clnt);
137                 if (!IS_ERR(dentry))
138                         break;
139                 if (dentry == ERR_PTR(-EEXIST))
140                         continue;
141                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
142                                 " %s/%s, error %ld\n",
143                                 dir_name, name, PTR_ERR(dentry));
144                 break;
145         }
146         dput(dir);
147         return dentry;
148 }
149 
150 static int
151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
152 {
153         struct dentry *dentry;
154 
155         if (clnt->cl_program->pipe_dir_name != NULL) {
156                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
157                 if (IS_ERR(dentry))
158                         return PTR_ERR(dentry);
159         }
160         return 0;
161 }
162 
163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
164 {
165         if (clnt->cl_program->pipe_dir_name == NULL)
166                 return 1;
167 
168         switch (event) {
169         case RPC_PIPEFS_MOUNT:
170                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
171                         return 1;
172                 if (atomic_read(&clnt->cl_count) == 0)
173                         return 1;
174                 break;
175         case RPC_PIPEFS_UMOUNT:
176                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
177                         return 1;
178                 break;
179         }
180         return 0;
181 }
182 
183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
184                                    struct super_block *sb)
185 {
186         struct dentry *dentry;
187 
188         switch (event) {
189         case RPC_PIPEFS_MOUNT:
190                 dentry = rpc_setup_pipedir_sb(sb, clnt);
191                 if (!dentry)
192                         return -ENOENT;
193                 if (IS_ERR(dentry))
194                         return PTR_ERR(dentry);
195                 break;
196         case RPC_PIPEFS_UMOUNT:
197                 __rpc_clnt_remove_pipedir(clnt);
198                 break;
199         default:
200                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
201                 return -ENOTSUPP;
202         }
203         return 0;
204 }
205 
206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
207                                 struct super_block *sb)
208 {
209         int error = 0;
210 
211         for (;; clnt = clnt->cl_parent) {
212                 if (!rpc_clnt_skip_event(clnt, event))
213                         error = __rpc_clnt_handle_event(clnt, event, sb);
214                 if (error || clnt == clnt->cl_parent)
215                         break;
216         }
217         return error;
218 }
219 
220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
221 {
222         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
223         struct rpc_clnt *clnt;
224 
225         spin_lock(&sn->rpc_client_lock);
226         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
227                 if (rpc_clnt_skip_event(clnt, event))
228                         continue;
229                 spin_unlock(&sn->rpc_client_lock);
230                 return clnt;
231         }
232         spin_unlock(&sn->rpc_client_lock);
233         return NULL;
234 }
235 
236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
237                             void *ptr)
238 {
239         struct super_block *sb = ptr;
240         struct rpc_clnt *clnt;
241         int error = 0;
242 
243         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
244                 error = __rpc_pipefs_event(clnt, event, sb);
245                 if (error)
246                         break;
247         }
248         return error;
249 }
250 
251 static struct notifier_block rpc_clients_block = {
252         .notifier_call  = rpc_pipefs_event,
253         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
254 };
255 
256 int rpc_clients_notifier_register(void)
257 {
258         return rpc_pipefs_notifier_register(&rpc_clients_block);
259 }
260 
261 void rpc_clients_notifier_unregister(void)
262 {
263         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
264 }
265 
266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
267                 struct rpc_xprt *xprt,
268                 const struct rpc_timeout *timeout)
269 {
270         struct rpc_xprt *old;
271 
272         spin_lock(&clnt->cl_lock);
273         old = rcu_dereference_protected(clnt->cl_xprt,
274                         lockdep_is_held(&clnt->cl_lock));
275 
276         if (!xprt_bound(xprt))
277                 clnt->cl_autobind = 1;
278 
279         clnt->cl_timeout = timeout;
280         rcu_assign_pointer(clnt->cl_xprt, xprt);
281         spin_unlock(&clnt->cl_lock);
282 
283         return old;
284 }
285 
286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
287 {
288         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
289                         nodename, sizeof(clnt->cl_nodename));
290 }
291 
292 static int rpc_client_register(struct rpc_clnt *clnt,
293                                rpc_authflavor_t pseudoflavor,
294                                const char *client_name)
295 {
296         struct rpc_auth_create_args auth_args = {
297                 .pseudoflavor = pseudoflavor,
298                 .target_name = client_name,
299         };
300         struct rpc_auth *auth;
301         struct net *net = rpc_net_ns(clnt);
302         struct super_block *pipefs_sb;
303         int err;
304 
305         rpc_clnt_debugfs_register(clnt);
306 
307         pipefs_sb = rpc_get_sb_net(net);
308         if (pipefs_sb) {
309                 err = rpc_setup_pipedir(pipefs_sb, clnt);
310                 if (err)
311                         goto out;
312         }
313 
314         rpc_register_client(clnt);
315         if (pipefs_sb)
316                 rpc_put_sb_net(net);
317 
318         auth = rpcauth_create(&auth_args, clnt);
319         if (IS_ERR(auth)) {
320                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
321                                 pseudoflavor);
322                 err = PTR_ERR(auth);
323                 goto err_auth;
324         }
325         return 0;
326 err_auth:
327         pipefs_sb = rpc_get_sb_net(net);
328         rpc_unregister_client(clnt);
329         __rpc_clnt_remove_pipedir(clnt);
330 out:
331         if (pipefs_sb)
332                 rpc_put_sb_net(net);
333         rpc_clnt_debugfs_unregister(clnt);
334         return err;
335 }
336 
337 static DEFINE_IDA(rpc_clids);
338 
339 void rpc_cleanup_clids(void)
340 {
341         ida_destroy(&rpc_clids);
342 }
343 
344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
345 {
346         int clid;
347 
348         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
349         if (clid < 0)
350                 return clid;
351         clnt->cl_clid = clid;
352         return 0;
353 }
354 
355 static void rpc_free_clid(struct rpc_clnt *clnt)
356 {
357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
358 }
359 
360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
361                 struct rpc_xprt_switch *xps,
362                 struct rpc_xprt *xprt,
363                 struct rpc_clnt *parent)
364 {
365         const struct rpc_program *program = args->program;
366         const struct rpc_version *version;
367         struct rpc_clnt *clnt = NULL;
368         const struct rpc_timeout *timeout;
369         const char *nodename = args->nodename;
370         int err;
371 
372         /* sanity check the name before trying to print it */
373         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
374                         program->name, args->servername, xprt);
375 
376         err = rpciod_up();
377         if (err)
378                 goto out_no_rpciod;
379 
380         err = -EINVAL;
381         if (args->version >= program->nrvers)
382                 goto out_err;
383         version = program->version[args->version];
384         if (version == NULL)
385                 goto out_err;
386 
387         err = -ENOMEM;
388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
389         if (!clnt)
390                 goto out_err;
391         clnt->cl_parent = parent ? : clnt;
392 
393         err = rpc_alloc_clid(clnt);
394         if (err)
395                 goto out_no_clid;
396 
397         clnt->cl_procinfo = version->procs;
398         clnt->cl_maxproc  = version->nrprocs;
399         clnt->cl_prog     = args->prognumber ? : program->number;
400         clnt->cl_vers     = version->number;
401         clnt->cl_stats    = program->stats;
402         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
403         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
404         err = -ENOMEM;
405         if (clnt->cl_metrics == NULL)
406                 goto out_no_stats;
407         clnt->cl_program  = program;
408         INIT_LIST_HEAD(&clnt->cl_tasks);
409         spin_lock_init(&clnt->cl_lock);
410 
411         timeout = xprt->timeout;
412         if (args->timeout != NULL) {
413                 memcpy(&clnt->cl_timeout_default, args->timeout,
414                                 sizeof(clnt->cl_timeout_default));
415                 timeout = &clnt->cl_timeout_default;
416         }
417 
418         rpc_clnt_set_transport(clnt, xprt, timeout);
419         xprt_iter_init(&clnt->cl_xpi, xps);
420         xprt_switch_put(xps);
421 
422         clnt->cl_rtt = &clnt->cl_rtt_default;
423         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
424 
425         atomic_set(&clnt->cl_count, 1);
426 
427         if (nodename == NULL)
428                 nodename = utsname()->nodename;
429         /* save the nodename */
430         rpc_clnt_set_nodename(clnt, nodename);
431 
432         err = rpc_client_register(clnt, args->authflavor, args->client_name);
433         if (err)
434                 goto out_no_path;
435         if (parent)
436                 atomic_inc(&parent->cl_count);
437         return clnt;
438 
439 out_no_path:
440         rpc_free_iostats(clnt->cl_metrics);
441 out_no_stats:
442         rpc_free_clid(clnt);
443 out_no_clid:
444         kfree(clnt);
445 out_err:
446         rpciod_down();
447 out_no_rpciod:
448         xprt_switch_put(xps);
449         xprt_put(xprt);
450         return ERR_PTR(err);
451 }
452 
453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
454                                         struct rpc_xprt *xprt)
455 {
456         struct rpc_clnt *clnt = NULL;
457         struct rpc_xprt_switch *xps;
458 
459         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
460                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
461                 xps = args->bc_xprt->xpt_bc_xps;
462                 xprt_switch_get(xps);
463         } else {
464                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
465                 if (xps == NULL) {
466                         xprt_put(xprt);
467                         return ERR_PTR(-ENOMEM);
468                 }
469                 if (xprt->bc_xprt) {
470                         xprt_switch_get(xps);
471                         xprt->bc_xprt->xpt_bc_xps = xps;
472                 }
473         }
474         clnt = rpc_new_client(args, xps, xprt, NULL);
475         if (IS_ERR(clnt))
476                 return clnt;
477 
478         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
479                 int err = rpc_ping(clnt);
480                 if (err != 0) {
481                         rpc_shutdown_client(clnt);
482                         return ERR_PTR(err);
483                 }
484         }
485 
486         clnt->cl_softrtry = 1;
487         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
488                 clnt->cl_softrtry = 0;
489 
490         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
491                 clnt->cl_autobind = 1;
492         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
493                 clnt->cl_noretranstimeo = 1;
494         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
495                 clnt->cl_discrtry = 1;
496         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
497                 clnt->cl_chatty = 1;
498 
499         return clnt;
500 }
501 
502 /**
503  * rpc_create - create an RPC client and transport with one call
504  * @args: rpc_clnt create argument structure
505  *
506  * Creates and initializes an RPC transport and an RPC client.
507  *
508  * It can ping the server in order to determine if it is up, and to see if
509  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
510  * this behavior so asynchronous tasks can also use rpc_create.
511  */
512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
513 {
514         struct rpc_xprt *xprt;
515         struct xprt_create xprtargs = {
516                 .net = args->net,
517                 .ident = args->protocol,
518                 .srcaddr = args->saddress,
519                 .dstaddr = args->address,
520                 .addrlen = args->addrsize,
521                 .servername = args->servername,
522                 .bc_xprt = args->bc_xprt,
523         };
524         char servername[48];
525 
526         if (args->bc_xprt) {
527                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
528                 xprt = args->bc_xprt->xpt_bc_xprt;
529                 if (xprt) {
530                         xprt_get(xprt);
531                         return rpc_create_xprt(args, xprt);
532                 }
533         }
534 
535         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
536                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
537         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
538                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
539         /*
540          * If the caller chooses not to specify a hostname, whip
541          * up a string representation of the passed-in address.
542          */
543         if (xprtargs.servername == NULL) {
544                 struct sockaddr_un *sun =
545                                 (struct sockaddr_un *)args->address;
546                 struct sockaddr_in *sin =
547                                 (struct sockaddr_in *)args->address;
548                 struct sockaddr_in6 *sin6 =
549                                 (struct sockaddr_in6 *)args->address;
550 
551                 servername[0] = '\0';
552                 switch (args->address->sa_family) {
553                 case AF_LOCAL:
554                         snprintf(servername, sizeof(servername), "%s",
555                                  sun->sun_path);
556                         break;
557                 case AF_INET:
558                         snprintf(servername, sizeof(servername), "%pI4",
559                                  &sin->sin_addr.s_addr);
560                         break;
561                 case AF_INET6:
562                         snprintf(servername, sizeof(servername), "%pI6",
563                                  &sin6->sin6_addr);
564                         break;
565                 default:
566                         /* caller wants default server name, but
567                          * address family isn't recognized. */
568                         return ERR_PTR(-EINVAL);
569                 }
570                 xprtargs.servername = servername;
571         }
572 
573         xprt = xprt_create_transport(&xprtargs);
574         if (IS_ERR(xprt))
575                 return (struct rpc_clnt *)xprt;
576 
577         /*
578          * By default, kernel RPC client connects from a reserved port.
579          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
580          * but it is always enabled for rpciod, which handles the connect
581          * operation.
582          */
583         xprt->resvport = 1;
584         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
585                 xprt->resvport = 0;
586 
587         return rpc_create_xprt(args, xprt);
588 }
589 EXPORT_SYMBOL_GPL(rpc_create);
590 
591 /*
592  * This function clones the RPC client structure. It allows us to share the
593  * same transport while varying parameters such as the authentication
594  * flavour.
595  */
596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
597                                            struct rpc_clnt *clnt)
598 {
599         struct rpc_xprt_switch *xps;
600         struct rpc_xprt *xprt;
601         struct rpc_clnt *new;
602         int err;
603 
604         err = -ENOMEM;
605         rcu_read_lock();
606         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
607         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
608         rcu_read_unlock();
609         if (xprt == NULL || xps == NULL) {
610                 xprt_put(xprt);
611                 xprt_switch_put(xps);
612                 goto out_err;
613         }
614         args->servername = xprt->servername;
615         args->nodename = clnt->cl_nodename;
616 
617         new = rpc_new_client(args, xps, xprt, clnt);
618         if (IS_ERR(new)) {
619                 err = PTR_ERR(new);
620                 goto out_err;
621         }
622 
623         /* Turn off autobind on clones */
624         new->cl_autobind = 0;
625         new->cl_softrtry = clnt->cl_softrtry;
626         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
627         new->cl_discrtry = clnt->cl_discrtry;
628         new->cl_chatty = clnt->cl_chatty;
629         return new;
630 
631 out_err:
632         dprintk("RPC:       %s: returned error %d\n", __func__, err);
633         return ERR_PTR(err);
634 }
635 
636 /**
637  * rpc_clone_client - Clone an RPC client structure
638  *
639  * @clnt: RPC client whose parameters are copied
640  *
641  * Returns a fresh RPC client or an ERR_PTR.
642  */
643 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
644 {
645         struct rpc_create_args args = {
646                 .program        = clnt->cl_program,
647                 .prognumber     = clnt->cl_prog,
648                 .version        = clnt->cl_vers,
649                 .authflavor     = clnt->cl_auth->au_flavor,
650         };
651         return __rpc_clone_client(&args, clnt);
652 }
653 EXPORT_SYMBOL_GPL(rpc_clone_client);
654 
655 /**
656  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
657  *
658  * @clnt: RPC client whose parameters are copied
659  * @flavor: security flavor for new client
660  *
661  * Returns a fresh RPC client or an ERR_PTR.
662  */
663 struct rpc_clnt *
664 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
665 {
666         struct rpc_create_args args = {
667                 .program        = clnt->cl_program,
668                 .prognumber     = clnt->cl_prog,
669                 .version        = clnt->cl_vers,
670                 .authflavor     = flavor,
671         };
672         return __rpc_clone_client(&args, clnt);
673 }
674 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
675 
676 /**
677  * rpc_switch_client_transport: switch the RPC transport on the fly
678  * @clnt: pointer to a struct rpc_clnt
679  * @args: pointer to the new transport arguments
680  * @timeout: pointer to the new timeout parameters
681  *
682  * This function allows the caller to switch the RPC transport for the
683  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
684  * server, for instance.  It assumes that the caller has ensured that
685  * there are no active RPC tasks by using some form of locking.
686  *
687  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
688  * negative errno is returned, and "clnt" continues to use the old
689  * xprt.
690  */
691 int rpc_switch_client_transport(struct rpc_clnt *clnt,
692                 struct xprt_create *args,
693                 const struct rpc_timeout *timeout)
694 {
695         const struct rpc_timeout *old_timeo;
696         rpc_authflavor_t pseudoflavor;
697         struct rpc_xprt_switch *xps, *oldxps;
698         struct rpc_xprt *xprt, *old;
699         struct rpc_clnt *parent;
700         int err;
701 
702         xprt = xprt_create_transport(args);
703         if (IS_ERR(xprt)) {
704                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
705                         clnt);
706                 return PTR_ERR(xprt);
707         }
708 
709         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
710         if (xps == NULL) {
711                 xprt_put(xprt);
712                 return -ENOMEM;
713         }
714 
715         pseudoflavor = clnt->cl_auth->au_flavor;
716 
717         old_timeo = clnt->cl_timeout;
718         old = rpc_clnt_set_transport(clnt, xprt, timeout);
719         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
720 
721         rpc_unregister_client(clnt);
722         __rpc_clnt_remove_pipedir(clnt);
723         rpc_clnt_debugfs_unregister(clnt);
724 
725         /*
726          * A new transport was created.  "clnt" therefore
727          * becomes the root of a new cl_parent tree.  clnt's
728          * children, if it has any, still point to the old xprt.
729          */
730         parent = clnt->cl_parent;
731         clnt->cl_parent = clnt;
732 
733         /*
734          * The old rpc_auth cache cannot be re-used.  GSS
735          * contexts in particular are between a single
736          * client and server.
737          */
738         err = rpc_client_register(clnt, pseudoflavor, NULL);
739         if (err)
740                 goto out_revert;
741 
742         synchronize_rcu();
743         if (parent != clnt)
744                 rpc_release_client(parent);
745         xprt_switch_put(oldxps);
746         xprt_put(old);
747         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
748         return 0;
749 
750 out_revert:
751         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
752         rpc_clnt_set_transport(clnt, old, old_timeo);
753         clnt->cl_parent = parent;
754         rpc_client_register(clnt, pseudoflavor, NULL);
755         xprt_switch_put(xps);
756         xprt_put(xprt);
757         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
758         return err;
759 }
760 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
761 
762 static
763 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
764 {
765         struct rpc_xprt_switch *xps;
766 
767         rcu_read_lock();
768         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
769         rcu_read_unlock();
770         if (xps == NULL)
771                 return -EAGAIN;
772         xprt_iter_init_listall(xpi, xps);
773         xprt_switch_put(xps);
774         return 0;
775 }
776 
777 /**
778  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
779  * @clnt: pointer to client
780  * @fn: function to apply
781  * @data: void pointer to function data
782  *
783  * Iterates through the list of RPC transports currently attached to the
784  * client and applies the function fn(clnt, xprt, data).
785  *
786  * On error, the iteration stops, and the function returns the error value.
787  */
788 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
789                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
790                 void *data)
791 {
792         struct rpc_xprt_iter xpi;
793         int ret;
794 
795         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
796         if (ret)
797                 return ret;
798         for (;;) {
799                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
800 
801                 if (!xprt)
802                         break;
803                 ret = fn(clnt, xprt, data);
804                 xprt_put(xprt);
805                 if (ret < 0)
806                         break;
807         }
808         xprt_iter_destroy(&xpi);
809         return ret;
810 }
811 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
812 
813 /*
814  * Kill all tasks for the given client.
815  * XXX: kill their descendants as well?
816  */
817 void rpc_killall_tasks(struct rpc_clnt *clnt)
818 {
819         struct rpc_task *rovr;
820 
821 
822         if (list_empty(&clnt->cl_tasks))
823                 return;
824         dprintk("RPC:       killing all tasks for client %p\n", clnt);
825         /*
826          * Spin lock all_tasks to prevent changes...
827          */
828         spin_lock(&clnt->cl_lock);
829         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
830                 if (!RPC_IS_ACTIVATED(rovr))
831                         continue;
832                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
833                         rovr->tk_flags |= RPC_TASK_KILLED;
834                         rpc_exit(rovr, -EIO);
835                         if (RPC_IS_QUEUED(rovr))
836                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
837                                                         rovr);
838                 }
839         }
840         spin_unlock(&clnt->cl_lock);
841 }
842 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
843 
844 /*
845  * Properly shut down an RPC client, terminating all outstanding
846  * requests.
847  */
848 void rpc_shutdown_client(struct rpc_clnt *clnt)
849 {
850         might_sleep();
851 
852         dprintk_rcu("RPC:       shutting down %s client for %s\n",
853                         clnt->cl_program->name,
854                         rcu_dereference(clnt->cl_xprt)->servername);
855 
856         while (!list_empty(&clnt->cl_tasks)) {
857                 rpc_killall_tasks(clnt);
858                 wait_event_timeout(destroy_wait,
859                         list_empty(&clnt->cl_tasks), 1*HZ);
860         }
861 
862         rpc_release_client(clnt);
863 }
864 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
865 
866 /*
867  * Free an RPC client
868  */
869 static struct rpc_clnt *
870 rpc_free_client(struct rpc_clnt *clnt)
871 {
872         struct rpc_clnt *parent = NULL;
873 
874         dprintk_rcu("RPC:       destroying %s client for %s\n",
875                         clnt->cl_program->name,
876                         rcu_dereference(clnt->cl_xprt)->servername);
877         if (clnt->cl_parent != clnt)
878                 parent = clnt->cl_parent;
879         rpc_clnt_debugfs_unregister(clnt);
880         rpc_clnt_remove_pipedir(clnt);
881         rpc_unregister_client(clnt);
882         rpc_free_iostats(clnt->cl_metrics);
883         clnt->cl_metrics = NULL;
884         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
885         xprt_iter_destroy(&clnt->cl_xpi);
886         rpciod_down();
887         rpc_free_clid(clnt);
888         kfree(clnt);
889         return parent;
890 }
891 
892 /*
893  * Free an RPC client
894  */
895 static struct rpc_clnt * 
896 rpc_free_auth(struct rpc_clnt *clnt)
897 {
898         if (clnt->cl_auth == NULL)
899                 return rpc_free_client(clnt);
900 
901         /*
902          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
903          *       release remaining GSS contexts. This mechanism ensures
904          *       that it can do so safely.
905          */
906         atomic_inc(&clnt->cl_count);
907         rpcauth_release(clnt->cl_auth);
908         clnt->cl_auth = NULL;
909         if (atomic_dec_and_test(&clnt->cl_count))
910                 return rpc_free_client(clnt);
911         return NULL;
912 }
913 
914 /*
915  * Release reference to the RPC client
916  */
917 void
918 rpc_release_client(struct rpc_clnt *clnt)
919 {
920         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
921 
922         do {
923                 if (list_empty(&clnt->cl_tasks))
924                         wake_up(&destroy_wait);
925                 if (!atomic_dec_and_test(&clnt->cl_count))
926                         break;
927                 clnt = rpc_free_auth(clnt);
928         } while (clnt != NULL);
929 }
930 EXPORT_SYMBOL_GPL(rpc_release_client);
931 
932 /**
933  * rpc_bind_new_program - bind a new RPC program to an existing client
934  * @old: old rpc_client
935  * @program: rpc program to set
936  * @vers: rpc program version
937  *
938  * Clones the rpc client and sets up a new RPC program. This is mainly
939  * of use for enabling different RPC programs to share the same transport.
940  * The Sun NFSv2/v3 ACL protocol can do this.
941  */
942 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
943                                       const struct rpc_program *program,
944                                       u32 vers)
945 {
946         struct rpc_create_args args = {
947                 .program        = program,
948                 .prognumber     = program->number,
949                 .version        = vers,
950                 .authflavor     = old->cl_auth->au_flavor,
951         };
952         struct rpc_clnt *clnt;
953         int err;
954 
955         clnt = __rpc_clone_client(&args, old);
956         if (IS_ERR(clnt))
957                 goto out;
958         err = rpc_ping(clnt);
959         if (err != 0) {
960                 rpc_shutdown_client(clnt);
961                 clnt = ERR_PTR(err);
962         }
963 out:
964         return clnt;
965 }
966 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
967 
968 void rpc_task_release_client(struct rpc_task *task)
969 {
970         struct rpc_clnt *clnt = task->tk_client;
971         struct rpc_xprt *xprt = task->tk_xprt;
972 
973         if (clnt != NULL) {
974                 /* Remove from client task list */
975                 spin_lock(&clnt->cl_lock);
976                 list_del(&task->tk_task);
977                 spin_unlock(&clnt->cl_lock);
978                 task->tk_client = NULL;
979 
980                 rpc_release_client(clnt);
981         }
982 
983         if (xprt != NULL) {
984                 task->tk_xprt = NULL;
985 
986                 xprt_put(xprt);
987         }
988 }
989 
990 static
991 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
992 {
993 
994         if (clnt != NULL) {
995                 if (task->tk_xprt == NULL)
996                         task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
997                 task->tk_client = clnt;
998                 atomic_inc(&clnt->cl_count);
999                 if (clnt->cl_softrtry)
1000                         task->tk_flags |= RPC_TASK_SOFT;
1001                 if (clnt->cl_noretranstimeo)
1002                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1003                 if (atomic_read(&clnt->cl_swapper))
1004                         task->tk_flags |= RPC_TASK_SWAPPER;
1005                 /* Add to the client's list of all tasks */
1006                 spin_lock(&clnt->cl_lock);
1007                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1008                 spin_unlock(&clnt->cl_lock);
1009         }
1010 }
1011 
1012 static void
1013 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1014 {
1015         if (msg != NULL) {
1016                 task->tk_msg.rpc_proc = msg->rpc_proc;
1017                 task->tk_msg.rpc_argp = msg->rpc_argp;
1018                 task->tk_msg.rpc_resp = msg->rpc_resp;
1019                 if (msg->rpc_cred != NULL)
1020                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1021         }
1022 }
1023 
1024 /*
1025  * Default callback for async RPC calls
1026  */
1027 static void
1028 rpc_default_callback(struct rpc_task *task, void *data)
1029 {
1030 }
1031 
1032 static const struct rpc_call_ops rpc_default_ops = {
1033         .rpc_call_done = rpc_default_callback,
1034 };
1035 
1036 /**
1037  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1038  * @task_setup_data: pointer to task initialisation data
1039  */
1040 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1041 {
1042         struct rpc_task *task;
1043 
1044         task = rpc_new_task(task_setup_data);
1045 
1046         rpc_task_set_client(task, task_setup_data->rpc_client);
1047         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1048 
1049         if (task->tk_action == NULL)
1050                 rpc_call_start(task);
1051 
1052         atomic_inc(&task->tk_count);
1053         rpc_execute(task);
1054         return task;
1055 }
1056 EXPORT_SYMBOL_GPL(rpc_run_task);
1057 
1058 /**
1059  * rpc_call_sync - Perform a synchronous RPC call
1060  * @clnt: pointer to RPC client
1061  * @msg: RPC call parameters
1062  * @flags: RPC call flags
1063  */
1064 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1065 {
1066         struct rpc_task *task;
1067         struct rpc_task_setup task_setup_data = {
1068                 .rpc_client = clnt,
1069                 .rpc_message = msg,
1070                 .callback_ops = &rpc_default_ops,
1071                 .flags = flags,
1072         };
1073         int status;
1074 
1075         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1076         if (flags & RPC_TASK_ASYNC) {
1077                 rpc_release_calldata(task_setup_data.callback_ops,
1078                         task_setup_data.callback_data);
1079                 return -EINVAL;
1080         }
1081 
1082         task = rpc_run_task(&task_setup_data);
1083         if (IS_ERR(task))
1084                 return PTR_ERR(task);
1085         status = task->tk_status;
1086         rpc_put_task(task);
1087         return status;
1088 }
1089 EXPORT_SYMBOL_GPL(rpc_call_sync);
1090 
1091 /**
1092  * rpc_call_async - Perform an asynchronous RPC call
1093  * @clnt: pointer to RPC client
1094  * @msg: RPC call parameters
1095  * @flags: RPC call flags
1096  * @tk_ops: RPC call ops
1097  * @data: user call data
1098  */
1099 int
1100 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1101                const struct rpc_call_ops *tk_ops, void *data)
1102 {
1103         struct rpc_task *task;
1104         struct rpc_task_setup task_setup_data = {
1105                 .rpc_client = clnt,
1106                 .rpc_message = msg,
1107                 .callback_ops = tk_ops,
1108                 .callback_data = data,
1109                 .flags = flags|RPC_TASK_ASYNC,
1110         };
1111 
1112         task = rpc_run_task(&task_setup_data);
1113         if (IS_ERR(task))
1114                 return PTR_ERR(task);
1115         rpc_put_task(task);
1116         return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(rpc_call_async);
1119 
1120 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1121 /**
1122  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1123  * rpc_execute against it
1124  * @req: RPC request
1125  */
1126 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1127 {
1128         struct rpc_task *task;
1129         struct xdr_buf *xbufp = &req->rq_snd_buf;
1130         struct rpc_task_setup task_setup_data = {
1131                 .callback_ops = &rpc_default_ops,
1132                 .flags = RPC_TASK_SOFTCONN,
1133         };
1134 
1135         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1136         /*
1137          * Create an rpc_task to send the data
1138          */
1139         task = rpc_new_task(&task_setup_data);
1140         task->tk_rqstp = req;
1141 
1142         /*
1143          * Set up the xdr_buf length.
1144          * This also indicates that the buffer is XDR encoded already.
1145          */
1146         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1147                         xbufp->tail[0].iov_len;
1148 
1149         task->tk_action = call_bc_transmit;
1150         atomic_inc(&task->tk_count);
1151         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1152         rpc_execute(task);
1153 
1154         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1155         return task;
1156 }
1157 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1158 
1159 void
1160 rpc_call_start(struct rpc_task *task)
1161 {
1162         task->tk_action = call_start;
1163 }
1164 EXPORT_SYMBOL_GPL(rpc_call_start);
1165 
1166 /**
1167  * rpc_peeraddr - extract remote peer address from clnt's xprt
1168  * @clnt: RPC client structure
1169  * @buf: target buffer
1170  * @bufsize: length of target buffer
1171  *
1172  * Returns the number of bytes that are actually in the stored address.
1173  */
1174 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1175 {
1176         size_t bytes;
1177         struct rpc_xprt *xprt;
1178 
1179         rcu_read_lock();
1180         xprt = rcu_dereference(clnt->cl_xprt);
1181 
1182         bytes = xprt->addrlen;
1183         if (bytes > bufsize)
1184                 bytes = bufsize;
1185         memcpy(buf, &xprt->addr, bytes);
1186         rcu_read_unlock();
1187 
1188         return bytes;
1189 }
1190 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1191 
1192 /**
1193  * rpc_peeraddr2str - return remote peer address in printable format
1194  * @clnt: RPC client structure
1195  * @format: address format
1196  *
1197  * NB: the lifetime of the memory referenced by the returned pointer is
1198  * the same as the rpc_xprt itself.  As long as the caller uses this
1199  * pointer, it must hold the RCU read lock.
1200  */
1201 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1202                              enum rpc_display_format_t format)
1203 {
1204         struct rpc_xprt *xprt;
1205 
1206         xprt = rcu_dereference(clnt->cl_xprt);
1207 
1208         if (xprt->address_strings[format] != NULL)
1209                 return xprt->address_strings[format];
1210         else
1211                 return "unprintable";
1212 }
1213 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1214 
1215 static const struct sockaddr_in rpc_inaddr_loopback = {
1216         .sin_family             = AF_INET,
1217         .sin_addr.s_addr        = htonl(INADDR_ANY),
1218 };
1219 
1220 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1221         .sin6_family            = AF_INET6,
1222         .sin6_addr              = IN6ADDR_ANY_INIT,
1223 };
1224 
1225 /*
1226  * Try a getsockname() on a connected datagram socket.  Using a
1227  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1228  * This conserves the ephemeral port number space.
1229  *
1230  * Returns zero and fills in "buf" if successful; otherwise, a
1231  * negative errno is returned.
1232  */
1233 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1234                         struct sockaddr *buf)
1235 {
1236         struct socket *sock;
1237         int err;
1238 
1239         err = __sock_create(net, sap->sa_family,
1240                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1241         if (err < 0) {
1242                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1243                 goto out;
1244         }
1245 
1246         switch (sap->sa_family) {
1247         case AF_INET:
1248                 err = kernel_bind(sock,
1249                                 (struct sockaddr *)&rpc_inaddr_loopback,
1250                                 sizeof(rpc_inaddr_loopback));
1251                 break;
1252         case AF_INET6:
1253                 err = kernel_bind(sock,
1254                                 (struct sockaddr *)&rpc_in6addr_loopback,
1255                                 sizeof(rpc_in6addr_loopback));
1256                 break;
1257         default:
1258                 err = -EAFNOSUPPORT;
1259                 goto out;
1260         }
1261         if (err < 0) {
1262                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1263                 goto out_release;
1264         }
1265 
1266         err = kernel_connect(sock, sap, salen, 0);
1267         if (err < 0) {
1268                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1269                 goto out_release;
1270         }
1271 
1272         err = kernel_getsockname(sock, buf);
1273         if (err < 0) {
1274                 dprintk("RPC:       getsockname failed (%d)\n", err);
1275                 goto out_release;
1276         }
1277 
1278         err = 0;
1279         if (buf->sa_family == AF_INET6) {
1280                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1281                 sin6->sin6_scope_id = 0;
1282         }
1283         dprintk("RPC:       %s succeeded\n", __func__);
1284 
1285 out_release:
1286         sock_release(sock);
1287 out:
1288         return err;
1289 }
1290 
1291 /*
1292  * Scraping a connected socket failed, so we don't have a useable
1293  * local address.  Fallback: generate an address that will prevent
1294  * the server from calling us back.
1295  *
1296  * Returns zero and fills in "buf" if successful; otherwise, a
1297  * negative errno is returned.
1298  */
1299 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1300 {
1301         switch (family) {
1302         case AF_INET:
1303                 if (buflen < sizeof(rpc_inaddr_loopback))
1304                         return -EINVAL;
1305                 memcpy(buf, &rpc_inaddr_loopback,
1306                                 sizeof(rpc_inaddr_loopback));
1307                 break;
1308         case AF_INET6:
1309                 if (buflen < sizeof(rpc_in6addr_loopback))
1310                         return -EINVAL;
1311                 memcpy(buf, &rpc_in6addr_loopback,
1312                                 sizeof(rpc_in6addr_loopback));
1313                 break;
1314         default:
1315                 dprintk("RPC:       %s: address family not supported\n",
1316                         __func__);
1317                 return -EAFNOSUPPORT;
1318         }
1319         dprintk("RPC:       %s: succeeded\n", __func__);
1320         return 0;
1321 }
1322 
1323 /**
1324  * rpc_localaddr - discover local endpoint address for an RPC client
1325  * @clnt: RPC client structure
1326  * @buf: target buffer
1327  * @buflen: size of target buffer, in bytes
1328  *
1329  * Returns zero and fills in "buf" and "buflen" if successful;
1330  * otherwise, a negative errno is returned.
1331  *
1332  * This works even if the underlying transport is not currently connected,
1333  * or if the upper layer never previously provided a source address.
1334  *
1335  * The result of this function call is transient: multiple calls in
1336  * succession may give different results, depending on how local
1337  * networking configuration changes over time.
1338  */
1339 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1340 {
1341         struct sockaddr_storage address;
1342         struct sockaddr *sap = (struct sockaddr *)&address;
1343         struct rpc_xprt *xprt;
1344         struct net *net;
1345         size_t salen;
1346         int err;
1347 
1348         rcu_read_lock();
1349         xprt = rcu_dereference(clnt->cl_xprt);
1350         salen = xprt->addrlen;
1351         memcpy(sap, &xprt->addr, salen);
1352         net = get_net(xprt->xprt_net);
1353         rcu_read_unlock();
1354 
1355         rpc_set_port(sap, 0);
1356         err = rpc_sockname(net, sap, salen, buf);
1357         put_net(net);
1358         if (err != 0)
1359                 /* Couldn't discover local address, return ANYADDR */
1360                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1361         return 0;
1362 }
1363 EXPORT_SYMBOL_GPL(rpc_localaddr);
1364 
1365 void
1366 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1367 {
1368         struct rpc_xprt *xprt;
1369 
1370         rcu_read_lock();
1371         xprt = rcu_dereference(clnt->cl_xprt);
1372         if (xprt->ops->set_buffer_size)
1373                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1374         rcu_read_unlock();
1375 }
1376 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1377 
1378 /**
1379  * rpc_net_ns - Get the network namespace for this RPC client
1380  * @clnt: RPC client to query
1381  *
1382  */
1383 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1384 {
1385         struct net *ret;
1386 
1387         rcu_read_lock();
1388         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1389         rcu_read_unlock();
1390         return ret;
1391 }
1392 EXPORT_SYMBOL_GPL(rpc_net_ns);
1393 
1394 /**
1395  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1396  * @clnt: RPC client to query
1397  *
1398  * For stream transports, this is one RPC record fragment (see RFC
1399  * 1831), as we don't support multi-record requests yet.  For datagram
1400  * transports, this is the size of an IP packet minus the IP, UDP, and
1401  * RPC header sizes.
1402  */
1403 size_t rpc_max_payload(struct rpc_clnt *clnt)
1404 {
1405         size_t ret;
1406 
1407         rcu_read_lock();
1408         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1409         rcu_read_unlock();
1410         return ret;
1411 }
1412 EXPORT_SYMBOL_GPL(rpc_max_payload);
1413 
1414 /**
1415  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1416  * @clnt: RPC client to query
1417  */
1418 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1419 {
1420         struct rpc_xprt *xprt;
1421         size_t ret;
1422 
1423         rcu_read_lock();
1424         xprt = rcu_dereference(clnt->cl_xprt);
1425         ret = xprt->ops->bc_maxpayload(xprt);
1426         rcu_read_unlock();
1427         return ret;
1428 }
1429 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1430 
1431 /**
1432  * rpc_force_rebind - force transport to check that remote port is unchanged
1433  * @clnt: client to rebind
1434  *
1435  */
1436 void rpc_force_rebind(struct rpc_clnt *clnt)
1437 {
1438         if (clnt->cl_autobind) {
1439                 rcu_read_lock();
1440                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1441                 rcu_read_unlock();
1442         }
1443 }
1444 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1445 
1446 /*
1447  * Restart an (async) RPC call from the call_prepare state.
1448  * Usually called from within the exit handler.
1449  */
1450 int
1451 rpc_restart_call_prepare(struct rpc_task *task)
1452 {
1453         if (RPC_ASSASSINATED(task))
1454                 return 0;
1455         task->tk_action = call_start;
1456         task->tk_status = 0;
1457         if (task->tk_ops->rpc_call_prepare != NULL)
1458                 task->tk_action = rpc_prepare_task;
1459         return 1;
1460 }
1461 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1462 
1463 /*
1464  * Restart an (async) RPC call. Usually called from within the
1465  * exit handler.
1466  */
1467 int
1468 rpc_restart_call(struct rpc_task *task)
1469 {
1470         if (RPC_ASSASSINATED(task))
1471                 return 0;
1472         task->tk_action = call_start;
1473         task->tk_status = 0;
1474         return 1;
1475 }
1476 EXPORT_SYMBOL_GPL(rpc_restart_call);
1477 
1478 const char
1479 *rpc_proc_name(const struct rpc_task *task)
1480 {
1481         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1482 
1483         if (proc) {
1484                 if (proc->p_name)
1485                         return proc->p_name;
1486                 else
1487                         return "NULL";
1488         } else
1489                 return "no proc";
1490 }
1491 
1492 /*
1493  * 0.  Initial state
1494  *
1495  *     Other FSM states can be visited zero or more times, but
1496  *     this state is visited exactly once for each RPC.
1497  */
1498 static void
1499 call_start(struct rpc_task *task)
1500 {
1501         struct rpc_clnt *clnt = task->tk_client;
1502         int idx = task->tk_msg.rpc_proc->p_statidx;
1503 
1504         trace_rpc_request(task);
1505         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1506                         clnt->cl_program->name, clnt->cl_vers,
1507                         rpc_proc_name(task),
1508                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1509 
1510         /* Increment call count (version might not be valid for ping) */
1511         if (clnt->cl_program->version[clnt->cl_vers])
1512                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1513         clnt->cl_stats->rpccnt++;
1514         task->tk_action = call_reserve;
1515 }
1516 
1517 /*
1518  * 1.   Reserve an RPC call slot
1519  */
1520 static void
1521 call_reserve(struct rpc_task *task)
1522 {
1523         dprint_status(task);
1524 
1525         task->tk_status  = 0;
1526         task->tk_action  = call_reserveresult;
1527         xprt_reserve(task);
1528 }
1529 
1530 static void call_retry_reserve(struct rpc_task *task);
1531 
1532 /*
1533  * 1b.  Grok the result of xprt_reserve()
1534  */
1535 static void
1536 call_reserveresult(struct rpc_task *task)
1537 {
1538         int status = task->tk_status;
1539 
1540         dprint_status(task);
1541 
1542         /*
1543          * After a call to xprt_reserve(), we must have either
1544          * a request slot or else an error status.
1545          */
1546         task->tk_status = 0;
1547         if (status >= 0) {
1548                 if (task->tk_rqstp) {
1549                         task->tk_action = call_refresh;
1550                         return;
1551                 }
1552 
1553                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1554                                 __func__, status);
1555                 rpc_exit(task, -EIO);
1556                 return;
1557         }
1558 
1559         /*
1560          * Even though there was an error, we may have acquired
1561          * a request slot somehow.  Make sure not to leak it.
1562          */
1563         if (task->tk_rqstp) {
1564                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1565                                 __func__, status);
1566                 xprt_release(task);
1567         }
1568 
1569         switch (status) {
1570         case -ENOMEM:
1571                 rpc_delay(task, HZ >> 2);
1572                 /* fall through */
1573         case -EAGAIN:   /* woken up; retry */
1574                 task->tk_action = call_retry_reserve;
1575                 return;
1576         case -EIO:      /* probably a shutdown */
1577                 break;
1578         default:
1579                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1580                                 __func__, status);
1581                 break;
1582         }
1583         rpc_exit(task, status);
1584 }
1585 
1586 /*
1587  * 1c.  Retry reserving an RPC call slot
1588  */
1589 static void
1590 call_retry_reserve(struct rpc_task *task)
1591 {
1592         dprint_status(task);
1593 
1594         task->tk_status  = 0;
1595         task->tk_action  = call_reserveresult;
1596         xprt_retry_reserve(task);
1597 }
1598 
1599 /*
1600  * 2.   Bind and/or refresh the credentials
1601  */
1602 static void
1603 call_refresh(struct rpc_task *task)
1604 {
1605         dprint_status(task);
1606 
1607         task->tk_action = call_refreshresult;
1608         task->tk_status = 0;
1609         task->tk_client->cl_stats->rpcauthrefresh++;
1610         rpcauth_refreshcred(task);
1611 }
1612 
1613 /*
1614  * 2a.  Process the results of a credential refresh
1615  */
1616 static void
1617 call_refreshresult(struct rpc_task *task)
1618 {
1619         int status = task->tk_status;
1620 
1621         dprint_status(task);
1622 
1623         task->tk_status = 0;
1624         task->tk_action = call_refresh;
1625         switch (status) {
1626         case 0:
1627                 if (rpcauth_uptodatecred(task)) {
1628                         task->tk_action = call_allocate;
1629                         return;
1630                 }
1631                 /* Use rate-limiting and a max number of retries if refresh
1632                  * had status 0 but failed to update the cred.
1633                  */
1634                 /* fall through */
1635         case -ETIMEDOUT:
1636                 rpc_delay(task, 3*HZ);
1637                 /* fall through */
1638         case -EAGAIN:
1639                 status = -EACCES;
1640                 /* fall through */
1641         case -EKEYEXPIRED:
1642                 if (!task->tk_cred_retry)
1643                         break;
1644                 task->tk_cred_retry--;
1645                 dprintk("RPC: %5u %s: retry refresh creds\n",
1646                                 task->tk_pid, __func__);
1647                 return;
1648         }
1649         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1650                                 task->tk_pid, __func__, status);
1651         rpc_exit(task, status);
1652 }
1653 
1654 /*
1655  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1656  *      (Note: buffer memory is freed in xprt_release).
1657  */
1658 static void
1659 call_allocate(struct rpc_task *task)
1660 {
1661         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1662         struct rpc_rqst *req = task->tk_rqstp;
1663         struct rpc_xprt *xprt = req->rq_xprt;
1664         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1665         int status;
1666 
1667         dprint_status(task);
1668 
1669         task->tk_status = 0;
1670         task->tk_action = call_bind;
1671 
1672         if (req->rq_buffer)
1673                 return;
1674 
1675         if (proc->p_proc != 0) {
1676                 BUG_ON(proc->p_arglen == 0);
1677                 if (proc->p_decode != NULL)
1678                         BUG_ON(proc->p_replen == 0);
1679         }
1680 
1681         /*
1682          * Calculate the size (in quads) of the RPC call
1683          * and reply headers, and convert both values
1684          * to byte sizes.
1685          */
1686         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1687         req->rq_callsize <<= 2;
1688         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1689         req->rq_rcvsize <<= 2;
1690 
1691         status = xprt->ops->buf_alloc(task);
1692         xprt_inject_disconnect(xprt);
1693         if (status == 0)
1694                 return;
1695         if (status != -ENOMEM) {
1696                 rpc_exit(task, status);
1697                 return;
1698         }
1699 
1700         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1701 
1702         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1703                 task->tk_action = call_allocate;
1704                 rpc_delay(task, HZ>>4);
1705                 return;
1706         }
1707 
1708         rpc_exit(task, -ERESTARTSYS);
1709 }
1710 
1711 static inline int
1712 rpc_task_need_encode(struct rpc_task *task)
1713 {
1714         return task->tk_rqstp->rq_snd_buf.len == 0;
1715 }
1716 
1717 static inline void
1718 rpc_task_force_reencode(struct rpc_task *task)
1719 {
1720         task->tk_rqstp->rq_snd_buf.len = 0;
1721         task->tk_rqstp->rq_bytes_sent = 0;
1722 }
1723 
1724 /*
1725  * 3.   Encode arguments of an RPC call
1726  */
1727 static void
1728 rpc_xdr_encode(struct rpc_task *task)
1729 {
1730         struct rpc_rqst *req = task->tk_rqstp;
1731         kxdreproc_t     encode;
1732         __be32          *p;
1733 
1734         dprint_status(task);
1735 
1736         xdr_buf_init(&req->rq_snd_buf,
1737                      req->rq_buffer,
1738                      req->rq_callsize);
1739         xdr_buf_init(&req->rq_rcv_buf,
1740                      req->rq_rbuffer,
1741                      req->rq_rcvsize);
1742 
1743         p = rpc_encode_header(task);
1744         if (p == NULL) {
1745                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1746                 rpc_exit(task, -EIO);
1747                 return;
1748         }
1749 
1750         encode = task->tk_msg.rpc_proc->p_encode;
1751         if (encode == NULL)
1752                 return;
1753 
1754         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1755                         task->tk_msg.rpc_argp);
1756 }
1757 
1758 /*
1759  * 4.   Get the server port number if not yet set
1760  */
1761 static void
1762 call_bind(struct rpc_task *task)
1763 {
1764         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1765 
1766         dprint_status(task);
1767 
1768         task->tk_action = call_connect;
1769         if (!xprt_bound(xprt)) {
1770                 task->tk_action = call_bind_status;
1771                 task->tk_timeout = xprt->bind_timeout;
1772                 xprt->ops->rpcbind(task);
1773         }
1774 }
1775 
1776 /*
1777  * 4a.  Sort out bind result
1778  */
1779 static void
1780 call_bind_status(struct rpc_task *task)
1781 {
1782         int status = -EIO;
1783 
1784         if (task->tk_status >= 0) {
1785                 dprint_status(task);
1786                 task->tk_status = 0;
1787                 task->tk_action = call_connect;
1788                 return;
1789         }
1790 
1791         trace_rpc_bind_status(task);
1792         switch (task->tk_status) {
1793         case -ENOMEM:
1794                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1795                 rpc_delay(task, HZ >> 2);
1796                 goto retry_timeout;
1797         case -EACCES:
1798                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1799                                 "unavailable\n", task->tk_pid);
1800                 /* fail immediately if this is an RPC ping */
1801                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1802                         status = -EOPNOTSUPP;
1803                         break;
1804                 }
1805                 if (task->tk_rebind_retry == 0)
1806                         break;
1807                 task->tk_rebind_retry--;
1808                 rpc_delay(task, 3*HZ);
1809                 goto retry_timeout;
1810         case -ETIMEDOUT:
1811                 dprintk("RPC: %5u rpcbind request timed out\n",
1812                                 task->tk_pid);
1813                 goto retry_timeout;
1814         case -EPFNOSUPPORT:
1815                 /* server doesn't support any rpcbind version we know of */
1816                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1817                                 task->tk_pid);
1818                 break;
1819         case -EPROTONOSUPPORT:
1820                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1821                                 task->tk_pid);
1822                 goto retry_timeout;
1823         case -ECONNREFUSED:             /* connection problems */
1824         case -ECONNRESET:
1825         case -ECONNABORTED:
1826         case -ENOTCONN:
1827         case -EHOSTDOWN:
1828         case -ENETDOWN:
1829         case -EHOSTUNREACH:
1830         case -ENETUNREACH:
1831         case -ENOBUFS:
1832         case -EPIPE:
1833                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1834                                 task->tk_pid, task->tk_status);
1835                 if (!RPC_IS_SOFTCONN(task)) {
1836                         rpc_delay(task, 5*HZ);
1837                         goto retry_timeout;
1838                 }
1839                 status = task->tk_status;
1840                 break;
1841         default:
1842                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1843                                 task->tk_pid, -task->tk_status);
1844         }
1845 
1846         rpc_exit(task, status);
1847         return;
1848 
1849 retry_timeout:
1850         task->tk_status = 0;
1851         task->tk_action = call_timeout;
1852 }
1853 
1854 /*
1855  * 4b.  Connect to the RPC server
1856  */
1857 static void
1858 call_connect(struct rpc_task *task)
1859 {
1860         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1861 
1862         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1863                         task->tk_pid, xprt,
1864                         (xprt_connected(xprt) ? "is" : "is not"));
1865 
1866         task->tk_action = call_transmit;
1867         if (!xprt_connected(xprt)) {
1868                 task->tk_action = call_connect_status;
1869                 if (task->tk_status < 0)
1870                         return;
1871                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1872                         rpc_exit(task, -ENOTCONN);
1873                         return;
1874                 }
1875                 xprt_connect(task);
1876         }
1877 }
1878 
1879 /*
1880  * 4c.  Sort out connect result
1881  */
1882 static void
1883 call_connect_status(struct rpc_task *task)
1884 {
1885         struct rpc_clnt *clnt = task->tk_client;
1886         int status = task->tk_status;
1887 
1888         dprint_status(task);
1889 
1890         trace_rpc_connect_status(task);
1891         task->tk_status = 0;
1892         switch (status) {
1893         case -ECONNREFUSED:
1894                 /* A positive refusal suggests a rebind is needed. */
1895                 if (RPC_IS_SOFTCONN(task))
1896                         break;
1897                 if (clnt->cl_autobind) {
1898                         rpc_force_rebind(clnt);
1899                         task->tk_action = call_bind;
1900                         return;
1901                 }
1902                 /* fall through */
1903         case -ECONNRESET:
1904         case -ECONNABORTED:
1905         case -ENETDOWN:
1906         case -ENETUNREACH:
1907         case -EHOSTUNREACH:
1908         case -EADDRINUSE:
1909         case -ENOBUFS:
1910         case -EPIPE:
1911                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1912                                             task->tk_rqstp->rq_connect_cookie);
1913                 if (RPC_IS_SOFTCONN(task))
1914                         break;
1915                 /* retry with existing socket, after a delay */
1916                 rpc_delay(task, 3*HZ);
1917                 /* fall through */
1918         case -EAGAIN:
1919                 /* Check for timeouts before looping back to call_bind */
1920         case -ETIMEDOUT:
1921                 task->tk_action = call_timeout;
1922                 return;
1923         case 0:
1924                 clnt->cl_stats->netreconn++;
1925                 task->tk_action = call_transmit;
1926                 return;
1927         }
1928         rpc_exit(task, status);
1929 }
1930 
1931 /*
1932  * 5.   Transmit the RPC request, and wait for reply
1933  */
1934 static void
1935 call_transmit(struct rpc_task *task)
1936 {
1937         int is_retrans = RPC_WAS_SENT(task);
1938 
1939         dprint_status(task);
1940 
1941         task->tk_action = call_status;
1942         if (task->tk_status < 0)
1943                 return;
1944         if (!xprt_prepare_transmit(task))
1945                 return;
1946         task->tk_action = call_transmit_status;
1947         /* Encode here so that rpcsec_gss can use correct sequence number. */
1948         if (rpc_task_need_encode(task)) {
1949                 rpc_xdr_encode(task);
1950                 /* Did the encode result in an error condition? */
1951                 if (task->tk_status != 0) {
1952                         /* Was the error nonfatal? */
1953                         if (task->tk_status == -EAGAIN)
1954                                 rpc_delay(task, HZ >> 4);
1955                         else
1956                                 rpc_exit(task, task->tk_status);
1957                         return;
1958                 }
1959         }
1960         xprt_transmit(task);
1961         if (task->tk_status < 0)
1962                 return;
1963         if (is_retrans)
1964                 task->tk_client->cl_stats->rpcretrans++;
1965         /*
1966          * On success, ensure that we call xprt_end_transmit() before sleeping
1967          * in order to allow access to the socket to other RPC requests.
1968          */
1969         call_transmit_status(task);
1970         if (rpc_reply_expected(task))
1971                 return;
1972         task->tk_action = rpc_exit_task;
1973         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1974 }
1975 
1976 /*
1977  * 5a.  Handle cleanup after a transmission
1978  */
1979 static void
1980 call_transmit_status(struct rpc_task *task)
1981 {
1982         task->tk_action = call_status;
1983 
1984         /*
1985          * Common case: success.  Force the compiler to put this
1986          * test first.
1987          */
1988         if (task->tk_status == 0) {
1989                 xprt_end_transmit(task);
1990                 rpc_task_force_reencode(task);
1991                 return;
1992         }
1993 
1994         switch (task->tk_status) {
1995         case -EAGAIN:
1996         case -ENOBUFS:
1997                 break;
1998         default:
1999                 dprint_status(task);
2000                 xprt_end_transmit(task);
2001                 rpc_task_force_reencode(task);
2002                 break;
2003                 /*
2004                  * Special cases: if we've been waiting on the
2005                  * socket's write_space() callback, or if the
2006                  * socket just returned a connection error,
2007                  * then hold onto the transport lock.
2008                  */
2009         case -ECONNREFUSED:
2010         case -EHOSTDOWN:
2011         case -ENETDOWN:
2012         case -EHOSTUNREACH:
2013         case -ENETUNREACH:
2014         case -EPERM:
2015                 if (RPC_IS_SOFTCONN(task)) {
2016                         xprt_end_transmit(task);
2017                         if (!task->tk_msg.rpc_proc->p_proc)
2018                                 trace_xprt_ping(task->tk_xprt,
2019                                                 task->tk_status);
2020                         rpc_exit(task, task->tk_status);
2021                         break;
2022                 }
2023                 /* fall through */
2024         case -ECONNRESET:
2025         case -ECONNABORTED:
2026         case -EADDRINUSE:
2027         case -ENOTCONN:
2028         case -EPIPE:
2029                 rpc_task_force_reencode(task);
2030         }
2031 }
2032 
2033 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2034 /*
2035  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2036  * addition, disconnect on connectivity errors.
2037  */
2038 static void
2039 call_bc_transmit(struct rpc_task *task)
2040 {
2041         struct rpc_rqst *req = task->tk_rqstp;
2042 
2043         if (!xprt_prepare_transmit(task))
2044                 goto out_retry;
2045 
2046         if (task->tk_status < 0) {
2047                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2048                         "error: %d\n", task->tk_status);
2049                 goto out_done;
2050         }
2051         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2052                 req->rq_bytes_sent = 0;
2053 
2054         xprt_transmit(task);
2055 
2056         if (task->tk_status == -EAGAIN)
2057                 goto out_nospace;
2058 
2059         xprt_end_transmit(task);
2060         dprint_status(task);
2061         switch (task->tk_status) {
2062         case 0:
2063                 /* Success */
2064         case -ENETDOWN:
2065         case -EHOSTDOWN:
2066         case -EHOSTUNREACH:
2067         case -ENETUNREACH:
2068         case -ECONNRESET:
2069         case -ECONNREFUSED:
2070         case -EADDRINUSE:
2071         case -ENOTCONN:
2072         case -EPIPE:
2073                 break;
2074         case -ETIMEDOUT:
2075                 /*
2076                  * Problem reaching the server.  Disconnect and let the
2077                  * forechannel reestablish the connection.  The server will
2078                  * have to retransmit the backchannel request and we'll
2079                  * reprocess it.  Since these ops are idempotent, there's no
2080                  * need to cache our reply at this time.
2081                  */
2082                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2083                         "error: %d\n", task->tk_status);
2084                 xprt_conditional_disconnect(req->rq_xprt,
2085                         req->rq_connect_cookie);
2086                 break;
2087         default:
2088                 /*
2089                  * We were unable to reply and will have to drop the
2090                  * request.  The server should reconnect and retransmit.
2091                  */
2092                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2093                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2094                         "error: %d\n", task->tk_status);
2095                 break;
2096         }
2097         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2098 out_done:
2099         task->tk_action = rpc_exit_task;
2100         return;
2101 out_nospace:
2102         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2103 out_retry:
2104         task->tk_status = 0;
2105 }
2106 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2107 
2108 /*
2109  * 6.   Sort out the RPC call status
2110  */
2111 static void
2112 call_status(struct rpc_task *task)
2113 {
2114         struct rpc_clnt *clnt = task->tk_client;
2115         struct rpc_rqst *req = task->tk_rqstp;
2116         int             status;
2117 
2118         if (!task->tk_msg.rpc_proc->p_proc)
2119                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2120 
2121         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2122                 task->tk_status = req->rq_reply_bytes_recvd;
2123 
2124         dprint_status(task);
2125 
2126         status = task->tk_status;
2127         if (status >= 0) {
2128                 task->tk_action = call_decode;
2129                 return;
2130         }
2131 
2132         trace_rpc_call_status(task);
2133         task->tk_status = 0;
2134         switch(status) {
2135         case -EHOSTDOWN:
2136         case -ENETDOWN:
2137         case -EHOSTUNREACH:
2138         case -ENETUNREACH:
2139         case -EPERM:
2140                 if (RPC_IS_SOFTCONN(task)) {
2141                         rpc_exit(task, status);
2142                         break;
2143                 }
2144                 /*
2145                  * Delay any retries for 3 seconds, then handle as if it
2146                  * were a timeout.
2147                  */
2148                 rpc_delay(task, 3*HZ);
2149                 /* fall through */
2150         case -ETIMEDOUT:
2151                 task->tk_action = call_timeout;
2152                 break;
2153         case -ECONNREFUSED:
2154         case -ECONNRESET:
2155         case -ECONNABORTED:
2156                 rpc_force_rebind(clnt);
2157                 /* fall through */
2158         case -EADDRINUSE:
2159                 rpc_delay(task, 3*HZ);
2160                 /* fall through */
2161         case -EPIPE:
2162         case -ENOTCONN:
2163                 task->tk_action = call_bind;
2164                 break;
2165         case -ENOBUFS:
2166                 rpc_delay(task, HZ>>2);
2167                 /* fall through */
2168         case -EAGAIN:
2169                 task->tk_action = call_transmit;
2170                 break;
2171         case -EIO:
2172                 /* shutdown or soft timeout */
2173                 rpc_exit(task, status);
2174                 break;
2175         default:
2176                 if (clnt->cl_chatty)
2177                         printk("%s: RPC call returned error %d\n",
2178                                clnt->cl_program->name, -status);
2179                 rpc_exit(task, status);
2180         }
2181 }
2182 
2183 /*
2184  * 6a.  Handle RPC timeout
2185  *      We do not release the request slot, so we keep using the
2186  *      same XID for all retransmits.
2187  */
2188 static void
2189 call_timeout(struct rpc_task *task)
2190 {
2191         struct rpc_clnt *clnt = task->tk_client;
2192 
2193         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2194                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2195                 goto retry;
2196         }
2197 
2198         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2199         task->tk_timeouts++;
2200 
2201         if (RPC_IS_SOFTCONN(task)) {
2202                 rpc_exit(task, -ETIMEDOUT);
2203                 return;
2204         }
2205         if (RPC_IS_SOFT(task)) {
2206                 if (clnt->cl_chatty) {
2207                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2208                                 clnt->cl_program->name,
2209                                 task->tk_xprt->servername);
2210                 }
2211                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2212                         rpc_exit(task, -ETIMEDOUT);
2213                 else
2214                         rpc_exit(task, -EIO);
2215                 return;
2216         }
2217 
2218         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2219                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2220                 if (clnt->cl_chatty) {
2221                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2222                         clnt->cl_program->name,
2223                         task->tk_xprt->servername);
2224                 }
2225         }
2226         rpc_force_rebind(clnt);
2227         /*
2228          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2229          * event? RFC2203 requires the server to drop all such requests.
2230          */
2231         rpcauth_invalcred(task);
2232 
2233 retry:
2234         task->tk_action = call_bind;
2235         task->tk_status = 0;
2236 }
2237 
2238 /*
2239  * 7.   Decode the RPC reply
2240  */
2241 static void
2242 call_decode(struct rpc_task *task)
2243 {
2244         struct rpc_clnt *clnt = task->tk_client;
2245         struct rpc_rqst *req = task->tk_rqstp;
2246         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2247         __be32          *p;
2248 
2249         dprint_status(task);
2250 
2251         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2252                 if (clnt->cl_chatty) {
2253                         printk(KERN_NOTICE "%s: server %s OK\n",
2254                                 clnt->cl_program->name,
2255                                 task->tk_xprt->servername);
2256                 }
2257                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2258         }
2259 
2260         /*
2261          * Ensure that we see all writes made by xprt_complete_rqst()
2262          * before it changed req->rq_reply_bytes_recvd.
2263          */
2264         smp_rmb();
2265         req->rq_rcv_buf.len = req->rq_private_buf.len;
2266 
2267         /* Check that the softirq receive buffer is valid */
2268         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2269                                 sizeof(req->rq_rcv_buf)) != 0);
2270 
2271         if (req->rq_rcv_buf.len < 12) {
2272                 if (!RPC_IS_SOFT(task)) {
2273                         task->tk_action = call_bind;
2274                         goto out_retry;
2275                 }
2276                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2277                                 clnt->cl_program->name, task->tk_status);
2278                 task->tk_action = call_timeout;
2279                 goto out_retry;
2280         }
2281 
2282         p = rpc_verify_header(task);
2283         if (IS_ERR(p)) {
2284                 if (p == ERR_PTR(-EAGAIN))
2285                         goto out_retry;
2286                 return;
2287         }
2288 
2289         task->tk_action = rpc_exit_task;
2290 
2291         if (decode) {
2292                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2293                                                       task->tk_msg.rpc_resp);
2294         }
2295         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2296                         task->tk_status);
2297         return;
2298 out_retry:
2299         task->tk_status = 0;
2300         /* Note: rpc_verify_header() may have freed the RPC slot */
2301         if (task->tk_rqstp == req) {
2302                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2303                 if (task->tk_client->cl_discrtry)
2304                         xprt_conditional_disconnect(req->rq_xprt,
2305                                         req->rq_connect_cookie);
2306         }
2307 }
2308 
2309 static __be32 *
2310 rpc_encode_header(struct rpc_task *task)
2311 {
2312         struct rpc_clnt *clnt = task->tk_client;
2313         struct rpc_rqst *req = task->tk_rqstp;
2314         __be32          *p = req->rq_svec[0].iov_base;
2315 
2316         /* FIXME: check buffer size? */
2317 
2318         p = xprt_skip_transport_header(req->rq_xprt, p);
2319         *p++ = req->rq_xid;             /* XID */
2320         *p++ = htonl(RPC_CALL);         /* CALL */
2321         *p++ = htonl(RPC_VERSION);      /* RPC version */
2322         *p++ = htonl(clnt->cl_prog);    /* program number */
2323         *p++ = htonl(clnt->cl_vers);    /* program version */
2324         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2325         p = rpcauth_marshcred(task, p);
2326         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2327         return p;
2328 }
2329 
2330 static __be32 *
2331 rpc_verify_header(struct rpc_task *task)
2332 {
2333         struct rpc_clnt *clnt = task->tk_client;
2334         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2335         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2336         __be32  *p = iov->iov_base;
2337         u32 n;
2338         int error = -EACCES;
2339 
2340         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2341                 /* RFC-1014 says that the representation of XDR data must be a
2342                  * multiple of four bytes
2343                  * - if it isn't pointer subtraction in the NFS client may give
2344                  *   undefined results
2345                  */
2346                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2347                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2348                        task->tk_rqstp->rq_rcv_buf.len);
2349                 error = -EIO;
2350                 goto out_err;
2351         }
2352         if ((len -= 3) < 0)
2353                 goto out_overflow;
2354 
2355         p += 1; /* skip XID */
2356         if ((n = ntohl(*p++)) != RPC_REPLY) {
2357                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2358                         task->tk_pid, __func__, n);
2359                 error = -EIO;
2360                 goto out_garbage;
2361         }
2362 
2363         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2364                 if (--len < 0)
2365                         goto out_overflow;
2366                 switch ((n = ntohl(*p++))) {
2367                 case RPC_AUTH_ERROR:
2368                         break;
2369                 case RPC_MISMATCH:
2370                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2371                                 task->tk_pid, __func__);
2372                         error = -EPROTONOSUPPORT;
2373                         goto out_err;
2374                 default:
2375                         dprintk("RPC: %5u %s: RPC call rejected, "
2376                                 "unknown error: %x\n",
2377                                 task->tk_pid, __func__, n);
2378                         error = -EIO;
2379                         goto out_err;
2380                 }
2381                 if (--len < 0)
2382                         goto out_overflow;
2383                 switch ((n = ntohl(*p++))) {
2384                 case RPC_AUTH_REJECTEDCRED:
2385                 case RPC_AUTH_REJECTEDVERF:
2386                 case RPCSEC_GSS_CREDPROBLEM:
2387                 case RPCSEC_GSS_CTXPROBLEM:
2388                         if (!task->tk_cred_retry)
2389                                 break;
2390                         task->tk_cred_retry--;
2391                         dprintk("RPC: %5u %s: retry stale creds\n",
2392                                         task->tk_pid, __func__);
2393                         rpcauth_invalcred(task);
2394                         /* Ensure we obtain a new XID! */
2395                         xprt_release(task);
2396                         task->tk_action = call_reserve;
2397                         goto out_retry;
2398                 case RPC_AUTH_BADCRED:
2399                 case RPC_AUTH_BADVERF:
2400                         /* possibly garbled cred/verf? */
2401                         if (!task->tk_garb_retry)
2402                                 break;
2403                         task->tk_garb_retry--;
2404                         dprintk("RPC: %5u %s: retry garbled creds\n",
2405                                         task->tk_pid, __func__);
2406                         task->tk_action = call_bind;
2407                         goto out_retry;
2408                 case RPC_AUTH_TOOWEAK:
2409                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2410                                "authentication.\n",
2411                                task->tk_xprt->servername);
2412                         break;
2413                 default:
2414                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2415                                         task->tk_pid, __func__, n);
2416                         error = -EIO;
2417                 }
2418                 dprintk("RPC: %5u %s: call rejected %d\n",
2419                                 task->tk_pid, __func__, n);
2420                 goto out_err;
2421         }
2422         p = rpcauth_checkverf(task, p);
2423         if (IS_ERR(p)) {
2424                 error = PTR_ERR(p);
2425                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2426                                 task->tk_pid, __func__, error);
2427                 goto out_garbage;               /* bad verifier, retry */
2428         }
2429         len = p - (__be32 *)iov->iov_base - 1;
2430         if (len < 0)
2431                 goto out_overflow;
2432         switch ((n = ntohl(*p++))) {
2433         case RPC_SUCCESS:
2434                 return p;
2435         case RPC_PROG_UNAVAIL:
2436                 dprintk("RPC: %5u %s: program %u is unsupported "
2437                                 "by server %s\n", task->tk_pid, __func__,
2438                                 (unsigned int)clnt->cl_prog,
2439                                 task->tk_xprt->servername);
2440                 error = -EPFNOSUPPORT;
2441                 goto out_err;
2442         case RPC_PROG_MISMATCH:
2443                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2444                                 "by server %s\n", task->tk_pid, __func__,
2445                                 (unsigned int)clnt->cl_prog,
2446                                 (unsigned int)clnt->cl_vers,
2447                                 task->tk_xprt->servername);
2448                 error = -EPROTONOSUPPORT;
2449                 goto out_err;
2450         case RPC_PROC_UNAVAIL:
2451                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2452                                 "version %u on server %s\n",
2453                                 task->tk_pid, __func__,
2454                                 rpc_proc_name(task),
2455                                 clnt->cl_prog, clnt->cl_vers,
2456                                 task->tk_xprt->servername);
2457                 error = -EOPNOTSUPP;
2458                 goto out_err;
2459         case RPC_GARBAGE_ARGS:
2460                 dprintk("RPC: %5u %s: server saw garbage\n",
2461                                 task->tk_pid, __func__);
2462                 break;                  /* retry */
2463         default:
2464                 dprintk("RPC: %5u %s: server accept status: %x\n",
2465                                 task->tk_pid, __func__, n);
2466                 /* Also retry */
2467         }
2468 
2469 out_garbage:
2470         clnt->cl_stats->rpcgarbage++;
2471         if (task->tk_garb_retry) {
2472                 task->tk_garb_retry--;
2473                 dprintk("RPC: %5u %s: retrying\n",
2474                                 task->tk_pid, __func__);
2475                 task->tk_action = call_bind;
2476 out_retry:
2477                 return ERR_PTR(-EAGAIN);
2478         }
2479 out_err:
2480         rpc_exit(task, error);
2481         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2482                         __func__, error);
2483         return ERR_PTR(error);
2484 out_overflow:
2485         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2486                         __func__);
2487         goto out_garbage;
2488 }
2489 
2490 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2491                 const void *obj)
2492 {
2493 }
2494 
2495 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2496                 void *obj)
2497 {
2498         return 0;
2499 }
2500 
2501 static const struct rpc_procinfo rpcproc_null = {
2502         .p_encode = rpcproc_encode_null,
2503         .p_decode = rpcproc_decode_null,
2504 };
2505 
2506 static int rpc_ping(struct rpc_clnt *clnt)
2507 {
2508         struct rpc_message msg = {
2509                 .rpc_proc = &rpcproc_null,
2510         };
2511         int err;
2512         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2513         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2514         put_rpccred(msg.rpc_cred);
2515         return err;
2516 }
2517 
2518 static
2519 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2520                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2521                 const struct rpc_call_ops *ops, void *data)
2522 {
2523         struct rpc_message msg = {
2524                 .rpc_proc = &rpcproc_null,
2525                 .rpc_cred = cred,
2526         };
2527         struct rpc_task_setup task_setup_data = {
2528                 .rpc_client = clnt,
2529                 .rpc_xprt = xprt,
2530                 .rpc_message = &msg,
2531                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2532                 .callback_data = data,
2533                 .flags = flags,
2534         };
2535 
2536         return rpc_run_task(&task_setup_data);
2537 }
2538 
2539 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2540 {
2541         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2542 }
2543 EXPORT_SYMBOL_GPL(rpc_call_null);
2544 
2545 struct rpc_cb_add_xprt_calldata {
2546         struct rpc_xprt_switch *xps;
2547         struct rpc_xprt *xprt;
2548 };
2549 
2550 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2551 {
2552         struct rpc_cb_add_xprt_calldata *data = calldata;
2553 
2554         if (task->tk_status == 0)
2555                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2556 }
2557 
2558 static void rpc_cb_add_xprt_release(void *calldata)
2559 {
2560         struct rpc_cb_add_xprt_calldata *data = calldata;
2561 
2562         xprt_put(data->xprt);
2563         xprt_switch_put(data->xps);
2564         kfree(data);
2565 }
2566 
2567 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2568         .rpc_call_done = rpc_cb_add_xprt_done,
2569         .rpc_release = rpc_cb_add_xprt_release,
2570 };
2571 
2572 /**
2573  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2574  * @clnt: pointer to struct rpc_clnt
2575  * @xps: pointer to struct rpc_xprt_switch,
2576  * @xprt: pointer struct rpc_xprt
2577  * @dummy: unused
2578  */
2579 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2580                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2581                 void *dummy)
2582 {
2583         struct rpc_cb_add_xprt_calldata *data;
2584         struct rpc_cred *cred;
2585         struct rpc_task *task;
2586 
2587         data = kmalloc(sizeof(*data), GFP_NOFS);
2588         if (!data)
2589                 return -ENOMEM;
2590         data->xps = xprt_switch_get(xps);
2591         data->xprt = xprt_get(xprt);
2592 
2593         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2594         task = rpc_call_null_helper(clnt, xprt, cred,
2595                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2596                         &rpc_cb_add_xprt_call_ops, data);
2597         put_rpccred(cred);
2598         if (IS_ERR(task))
2599                 return PTR_ERR(task);
2600         rpc_put_task(task);
2601         return 1;
2602 }
2603 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2604 
2605 /**
2606  * rpc_clnt_setup_test_and_add_xprt()
2607  *
2608  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2609  *   1) caller of the test function must dereference the rpc_xprt_switch
2610  *   and the rpc_xprt.
2611  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2612  *   the rpc_call_done routine.
2613  *
2614  * Upon success (return of 1), the test function adds the new
2615  * transport to the rpc_clnt xprt switch
2616  *
2617  * @clnt: struct rpc_clnt to get the new transport
2618  * @xps:  the rpc_xprt_switch to hold the new transport
2619  * @xprt: the rpc_xprt to test
2620  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2621  *        and test function call data
2622  */
2623 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2624                                      struct rpc_xprt_switch *xps,
2625                                      struct rpc_xprt *xprt,
2626                                      void *data)
2627 {
2628         struct rpc_cred *cred;
2629         struct rpc_task *task;
2630         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2631         int status = -EADDRINUSE;
2632 
2633         xprt = xprt_get(xprt);
2634         xprt_switch_get(xps);
2635 
2636         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2637                 goto out_err;
2638 
2639         /* Test the connection */
2640         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2641         task = rpc_call_null_helper(clnt, xprt, cred,
2642                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2643                                     NULL, NULL);
2644         put_rpccred(cred);
2645         if (IS_ERR(task)) {
2646                 status = PTR_ERR(task);
2647                 goto out_err;
2648         }
2649         status = task->tk_status;
2650         rpc_put_task(task);
2651 
2652         if (status < 0)
2653                 goto out_err;
2654 
2655         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2656         xtest->add_xprt_test(clnt, xprt, xtest->data);
2657 
2658         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2659         return 1;
2660 out_err:
2661         xprt_put(xprt);
2662         xprt_switch_put(xps);
2663         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2664                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2665         return status;
2666 }
2667 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2668 
2669 /**
2670  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2671  * @clnt: pointer to struct rpc_clnt
2672  * @xprtargs: pointer to struct xprt_create
2673  * @setup: callback to test and/or set up the connection
2674  * @data: pointer to setup function data
2675  *
2676  * Creates a new transport using the parameters set in args and
2677  * adds it to clnt.
2678  * If ping is set, then test that connectivity succeeds before
2679  * adding the new transport.
2680  *
2681  */
2682 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2683                 struct xprt_create *xprtargs,
2684                 int (*setup)(struct rpc_clnt *,
2685                         struct rpc_xprt_switch *,
2686                         struct rpc_xprt *,
2687                         void *),
2688                 void *data)
2689 {
2690         struct rpc_xprt_switch *xps;
2691         struct rpc_xprt *xprt;
2692         unsigned long connect_timeout;
2693         unsigned long reconnect_timeout;
2694         unsigned char resvport;
2695         int ret = 0;
2696 
2697         rcu_read_lock();
2698         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2699         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2700         if (xps == NULL || xprt == NULL) {
2701                 rcu_read_unlock();
2702                 return -EAGAIN;
2703         }
2704         resvport = xprt->resvport;
2705         connect_timeout = xprt->connect_timeout;
2706         reconnect_timeout = xprt->max_reconnect_timeout;
2707         rcu_read_unlock();
2708 
2709         xprt = xprt_create_transport(xprtargs);
2710         if (IS_ERR(xprt)) {
2711                 ret = PTR_ERR(xprt);
2712                 goto out_put_switch;
2713         }
2714         xprt->resvport = resvport;
2715         if (xprt->ops->set_connect_timeout != NULL)
2716                 xprt->ops->set_connect_timeout(xprt,
2717                                 connect_timeout,
2718                                 reconnect_timeout);
2719 
2720         rpc_xprt_switch_set_roundrobin(xps);
2721         if (setup) {
2722                 ret = setup(clnt, xps, xprt, data);
2723                 if (ret != 0)
2724                         goto out_put_xprt;
2725         }
2726         rpc_xprt_switch_add_xprt(xps, xprt);
2727 out_put_xprt:
2728         xprt_put(xprt);
2729 out_put_switch:
2730         xprt_switch_put(xps);
2731         return ret;
2732 }
2733 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2734 
2735 struct connect_timeout_data {
2736         unsigned long connect_timeout;
2737         unsigned long reconnect_timeout;
2738 };
2739 
2740 static int
2741 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2742                 struct rpc_xprt *xprt,
2743                 void *data)
2744 {
2745         struct connect_timeout_data *timeo = data;
2746 
2747         if (xprt->ops->set_connect_timeout)
2748                 xprt->ops->set_connect_timeout(xprt,
2749                                 timeo->connect_timeout,
2750                                 timeo->reconnect_timeout);
2751         return 0;
2752 }
2753 
2754 void
2755 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2756                 unsigned long connect_timeout,
2757                 unsigned long reconnect_timeout)
2758 {
2759         struct connect_timeout_data timeout = {
2760                 .connect_timeout = connect_timeout,
2761                 .reconnect_timeout = reconnect_timeout,
2762         };
2763         rpc_clnt_iterate_for_each_xprt(clnt,
2764                         rpc_xprt_set_connect_timeout,
2765                         &timeout);
2766 }
2767 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2768 
2769 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2770 {
2771         rcu_read_lock();
2772         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2773         rcu_read_unlock();
2774 }
2775 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2776 
2777 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2778 {
2779         rcu_read_lock();
2780         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2781                                  xprt);
2782         rcu_read_unlock();
2783 }
2784 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2785 
2786 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2787                                    const struct sockaddr *sap)
2788 {
2789         struct rpc_xprt_switch *xps;
2790         bool ret;
2791 
2792         rcu_read_lock();
2793         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2794         ret = rpc_xprt_switch_has_addr(xps, sap);
2795         rcu_read_unlock();
2796         return ret;
2797 }
2798 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2799 
2800 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2801 static void rpc_show_header(void)
2802 {
2803         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2804                 "-timeout ---ops--\n");
2805 }
2806 
2807 static void rpc_show_task(const struct rpc_clnt *clnt,
2808                           const struct rpc_task *task)
2809 {
2810         const char *rpc_waitq = "none";
2811 
2812         if (RPC_IS_QUEUED(task))
2813                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2814 
2815         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2816                 task->tk_pid, task->tk_flags, task->tk_status,
2817                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2818                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2819                 task->tk_action, rpc_waitq);
2820 }
2821 
2822 void rpc_show_tasks(struct net *net)
2823 {
2824         struct rpc_clnt *clnt;
2825         struct rpc_task *task;
2826         int header = 0;
2827         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2828 
2829         spin_lock(&sn->rpc_client_lock);
2830         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2831                 spin_lock(&clnt->cl_lock);
2832                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2833                         if (!header) {
2834                                 rpc_show_header();
2835                                 header++;
2836                         }
2837                         rpc_show_task(clnt, task);
2838                 }
2839                 spin_unlock(&clnt->cl_lock);
2840         }
2841         spin_unlock(&sn->rpc_client_lock);
2842 }
2843 #endif
2844 
2845 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2846 static int
2847 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2848                 struct rpc_xprt *xprt,
2849                 void *dummy)
2850 {
2851         return xprt_enable_swap(xprt);
2852 }
2853 
2854 int
2855 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2856 {
2857         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2858                 return rpc_clnt_iterate_for_each_xprt(clnt,
2859                                 rpc_clnt_swap_activate_callback, NULL);
2860         return 0;
2861 }
2862 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2863 
2864 static int
2865 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2866                 struct rpc_xprt *xprt,
2867                 void *dummy)
2868 {
2869         xprt_disable_swap(xprt);
2870         return 0;
2871 }
2872 
2873 void
2874 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2875 {
2876         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2877                 rpc_clnt_iterate_for_each_xprt(clnt,
2878                                 rpc_clnt_swap_deactivate_callback, NULL);
2879 }
2880 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2881 #endif /* CONFIG_SUNRPC_SWAP */
2882 

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