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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/utsname.h>
29 #include <linux/workqueue.h>
30 #include <linux/in.h>
31 #include <linux/in6.h>
32 #include <linux/un.h>
33 #include <linux/rcupdate.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 #ifdef RPC_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 
rpc_register_client(struct rpc_clnt * clnt)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 
rpc_unregister_client(struct rpc_clnt * clnt)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 
__rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105 	if (clnt->cl_dentry) {
106 		if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
107 			clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
108 		rpc_remove_client_dir(clnt->cl_dentry);
109 	}
110 	clnt->cl_dentry = NULL;
111 }
112 
rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)113 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
114 {
115 	struct net *net = rpc_net_ns(clnt);
116 	struct super_block *pipefs_sb;
117 
118 	pipefs_sb = rpc_get_sb_net(net);
119 	if (pipefs_sb) {
120 		__rpc_clnt_remove_pipedir(clnt);
121 		rpc_put_sb_net(net);
122 	}
123 }
124 
rpc_setup_pipedir_sb(struct super_block * sb,struct rpc_clnt * clnt,const char * dir_name)125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
126 				    struct rpc_clnt *clnt,
127 				    const char *dir_name)
128 {
129 	static uint32_t clntid;
130 	char name[15];
131 	struct qstr q = { .name = name };
132 	struct dentry *dir, *dentry;
133 	int error;
134 
135 	dir = rpc_d_lookup_sb(sb, dir_name);
136 	if (dir == NULL) {
137 		pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
138 		return dir;
139 	}
140 	for (;;) {
141 		q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
142 		name[sizeof(name) - 1] = '\0';
143 		q.hash = full_name_hash(q.name, q.len);
144 		dentry = rpc_create_client_dir(dir, &q, clnt);
145 		if (!IS_ERR(dentry))
146 			break;
147 		error = PTR_ERR(dentry);
148 		if (error != -EEXIST) {
149 			printk(KERN_INFO "RPC: Couldn't create pipefs entry"
150 					" %s/%s, error %d\n",
151 					dir_name, name, error);
152 			break;
153 		}
154 	}
155 	dput(dir);
156 	return dentry;
157 }
158 
159 static int
rpc_setup_pipedir(struct rpc_clnt * clnt,const char * dir_name)160 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
161 {
162 	struct net *net = rpc_net_ns(clnt);
163 	struct super_block *pipefs_sb;
164 	struct dentry *dentry;
165 
166 	clnt->cl_dentry = NULL;
167 	if (dir_name == NULL)
168 		return 0;
169 	pipefs_sb = rpc_get_sb_net(net);
170 	if (!pipefs_sb)
171 		return 0;
172 	dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
173 	rpc_put_sb_net(net);
174 	if (IS_ERR(dentry))
175 		return PTR_ERR(dentry);
176 	clnt->cl_dentry = dentry;
177 	return 0;
178 }
179 
rpc_clnt_skip_event(struct rpc_clnt * clnt,unsigned long event)180 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
181 {
182 	if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
183 	    ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
184 		return 1;
185 	return 0;
186 }
187 
__rpc_clnt_handle_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)188 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
189 				   struct super_block *sb)
190 {
191 	struct dentry *dentry;
192 	int err = 0;
193 
194 	switch (event) {
195 	case RPC_PIPEFS_MOUNT:
196 		dentry = rpc_setup_pipedir_sb(sb, clnt,
197 					      clnt->cl_program->pipe_dir_name);
198 		if (!dentry)
199 			return -ENOENT;
200 		if (IS_ERR(dentry))
201 			return PTR_ERR(dentry);
202 		clnt->cl_dentry = dentry;
203 		if (clnt->cl_auth->au_ops->pipes_create) {
204 			err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
205 			if (err)
206 				__rpc_clnt_remove_pipedir(clnt);
207 		}
208 		break;
209 	case RPC_PIPEFS_UMOUNT:
210 		__rpc_clnt_remove_pipedir(clnt);
211 		break;
212 	default:
213 		printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
214 		return -ENOTSUPP;
215 	}
216 	return err;
217 }
218 
__rpc_pipefs_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)219 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
220 				struct super_block *sb)
221 {
222 	int error = 0;
223 
224 	for (;; clnt = clnt->cl_parent) {
225 		if (!rpc_clnt_skip_event(clnt, event))
226 			error = __rpc_clnt_handle_event(clnt, event, sb);
227 		if (error || clnt == clnt->cl_parent)
228 			break;
229 	}
230 	return error;
231 }
232 
rpc_get_client_for_event(struct net * net,int event)233 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
234 {
235 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
236 	struct rpc_clnt *clnt;
237 
238 	spin_lock(&sn->rpc_client_lock);
239 	list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
240 		if (clnt->cl_program->pipe_dir_name == NULL)
241 			continue;
242 		if (rpc_clnt_skip_event(clnt, event))
243 			continue;
244 		if (atomic_inc_not_zero(&clnt->cl_count) == 0)
245 			continue;
246 		spin_unlock(&sn->rpc_client_lock);
247 		return clnt;
248 	}
249 	spin_unlock(&sn->rpc_client_lock);
250 	return NULL;
251 }
252 
rpc_pipefs_event(struct notifier_block * nb,unsigned long event,void * ptr)253 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
254 			    void *ptr)
255 {
256 	struct super_block *sb = ptr;
257 	struct rpc_clnt *clnt;
258 	int error = 0;
259 
260 	while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
261 		error = __rpc_pipefs_event(clnt, event, sb);
262 		rpc_release_client(clnt);
263 		if (error)
264 			break;
265 	}
266 	return error;
267 }
268 
269 static struct notifier_block rpc_clients_block = {
270 	.notifier_call	= rpc_pipefs_event,
271 	.priority	= SUNRPC_PIPEFS_RPC_PRIO,
272 };
273 
rpc_clients_notifier_register(void)274 int rpc_clients_notifier_register(void)
275 {
276 	return rpc_pipefs_notifier_register(&rpc_clients_block);
277 }
278 
rpc_clients_notifier_unregister(void)279 void rpc_clients_notifier_unregister(void)
280 {
281 	return rpc_pipefs_notifier_unregister(&rpc_clients_block);
282 }
283 
rpc_clnt_set_nodename(struct rpc_clnt * clnt,const char * nodename)284 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
285 {
286 	clnt->cl_nodelen = strlen(nodename);
287 	if (clnt->cl_nodelen > UNX_MAXNODENAME)
288 		clnt->cl_nodelen = UNX_MAXNODENAME;
289 	memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
290 }
291 
rpc_new_client(const struct rpc_create_args * args,struct rpc_xprt * xprt)292 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
293 {
294 	const struct rpc_program *program = args->program;
295 	const struct rpc_version *version;
296 	struct rpc_clnt		*clnt = NULL;
297 	struct rpc_auth		*auth;
298 	int err;
299 
300 	/* sanity check the name before trying to print it */
301 	dprintk("RPC:       creating %s client for %s (xprt %p)\n",
302 			program->name, args->servername, xprt);
303 
304 	err = rpciod_up();
305 	if (err)
306 		goto out_no_rpciod;
307 
308 	err = -EINVAL;
309 	if (args->version >= program->nrvers)
310 		goto out_err;
311 	version = program->version[args->version];
312 	if (version == NULL)
313 		goto out_err;
314 
315 	err = -ENOMEM;
316 	clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
317 	if (!clnt)
318 		goto out_err;
319 	clnt->cl_parent = clnt;
320 
321 	rcu_assign_pointer(clnt->cl_xprt, xprt);
322 	clnt->cl_procinfo = version->procs;
323 	clnt->cl_maxproc  = version->nrprocs;
324 	clnt->cl_protname = program->name;
325 	clnt->cl_prog     = args->prognumber ? : program->number;
326 	clnt->cl_vers     = version->number;
327 	clnt->cl_stats    = program->stats;
328 	clnt->cl_metrics  = rpc_alloc_iostats(clnt);
329 	err = -ENOMEM;
330 	if (clnt->cl_metrics == NULL)
331 		goto out_no_stats;
332 	clnt->cl_program  = program;
333 	INIT_LIST_HEAD(&clnt->cl_tasks);
334 	spin_lock_init(&clnt->cl_lock);
335 
336 	if (!xprt_bound(xprt))
337 		clnt->cl_autobind = 1;
338 
339 	clnt->cl_timeout = xprt->timeout;
340 	if (args->timeout != NULL) {
341 		memcpy(&clnt->cl_timeout_default, args->timeout,
342 				sizeof(clnt->cl_timeout_default));
343 		clnt->cl_timeout = &clnt->cl_timeout_default;
344 	}
345 
346 	clnt->cl_rtt = &clnt->cl_rtt_default;
347 	rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
348 	clnt->cl_principal = NULL;
349 	if (args->client_name) {
350 		clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
351 		if (!clnt->cl_principal)
352 			goto out_no_principal;
353 	}
354 
355 	atomic_set(&clnt->cl_count, 1);
356 
357 	err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
358 	if (err < 0)
359 		goto out_no_path;
360 
361 	auth = rpcauth_create(args->authflavor, clnt);
362 	if (IS_ERR(auth)) {
363 		dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
364 				args->authflavor);
365 		err = PTR_ERR(auth);
366 		goto out_no_auth;
367 	}
368 
369 	/* save the nodename */
370 	rpc_clnt_set_nodename(clnt, utsname()->nodename);
371 	rpc_register_client(clnt);
372 	return clnt;
373 
374 out_no_auth:
375 	rpc_clnt_remove_pipedir(clnt);
376 out_no_path:
377 	kfree(clnt->cl_principal);
378 out_no_principal:
379 	rpc_free_iostats(clnt->cl_metrics);
380 out_no_stats:
381 	kfree(clnt);
382 out_err:
383 	rpciod_down();
384 out_no_rpciod:
385 	xprt_put(xprt);
386 	return ERR_PTR(err);
387 }
388 
389 /**
390  * rpc_create - create an RPC client and transport with one call
391  * @args: rpc_clnt create argument structure
392  *
393  * Creates and initializes an RPC transport and an RPC client.
394  *
395  * It can ping the server in order to determine if it is up, and to see if
396  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
397  * this behavior so asynchronous tasks can also use rpc_create.
398  */
rpc_create(struct rpc_create_args * args)399 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
400 {
401 	struct rpc_xprt *xprt;
402 	struct rpc_clnt *clnt;
403 	struct xprt_create xprtargs = {
404 		.net = args->net,
405 		.ident = args->protocol,
406 		.srcaddr = args->saddress,
407 		.dstaddr = args->address,
408 		.addrlen = args->addrsize,
409 		.servername = args->servername,
410 		.bc_xprt = args->bc_xprt,
411 	};
412 	char servername[48];
413 
414 	if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
415 		xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
416 	if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
417 		xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
418 	/*
419 	 * If the caller chooses not to specify a hostname, whip
420 	 * up a string representation of the passed-in address.
421 	 */
422 	if (xprtargs.servername == NULL) {
423 		struct sockaddr_un *sun =
424 				(struct sockaddr_un *)args->address;
425 		struct sockaddr_in *sin =
426 				(struct sockaddr_in *)args->address;
427 		struct sockaddr_in6 *sin6 =
428 				(struct sockaddr_in6 *)args->address;
429 
430 		servername[0] = '\0';
431 		switch (args->address->sa_family) {
432 		case AF_LOCAL:
433 			snprintf(servername, sizeof(servername), "%s",
434 				 sun->sun_path);
435 			break;
436 		case AF_INET:
437 			snprintf(servername, sizeof(servername), "%pI4",
438 				 &sin->sin_addr.s_addr);
439 			break;
440 		case AF_INET6:
441 			snprintf(servername, sizeof(servername), "%pI6",
442 				 &sin6->sin6_addr);
443 			break;
444 		default:
445 			/* caller wants default server name, but
446 			 * address family isn't recognized. */
447 			return ERR_PTR(-EINVAL);
448 		}
449 		xprtargs.servername = servername;
450 	}
451 
452 	xprt = xprt_create_transport(&xprtargs);
453 	if (IS_ERR(xprt))
454 		return (struct rpc_clnt *)xprt;
455 
456 	/*
457 	 * By default, kernel RPC client connects from a reserved port.
458 	 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
459 	 * but it is always enabled for rpciod, which handles the connect
460 	 * operation.
461 	 */
462 	xprt->resvport = 1;
463 	if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
464 		xprt->resvport = 0;
465 
466 	clnt = rpc_new_client(args, xprt);
467 	if (IS_ERR(clnt))
468 		return clnt;
469 
470 	if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
471 		int err = rpc_ping(clnt);
472 		if (err != 0) {
473 			rpc_shutdown_client(clnt);
474 			return ERR_PTR(err);
475 		}
476 	}
477 
478 	clnt->cl_softrtry = 1;
479 	if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
480 		clnt->cl_softrtry = 0;
481 
482 	if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
483 		clnt->cl_autobind = 1;
484 	if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
485 		clnt->cl_discrtry = 1;
486 	if (!(args->flags & RPC_CLNT_CREATE_QUIET))
487 		clnt->cl_chatty = 1;
488 
489 	return clnt;
490 }
491 EXPORT_SYMBOL_GPL(rpc_create);
492 
493 /*
494  * This function clones the RPC client structure. It allows us to share the
495  * same transport while varying parameters such as the authentication
496  * flavour.
497  */
__rpc_clone_client(struct rpc_create_args * args,struct rpc_clnt * clnt)498 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
499 					   struct rpc_clnt *clnt)
500 {
501 	struct rpc_xprt *xprt;
502 	struct rpc_clnt *new;
503 	int err;
504 
505 	err = -ENOMEM;
506 	rcu_read_lock();
507 	xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
508 	rcu_read_unlock();
509 	if (xprt == NULL)
510 		goto out_err;
511 	args->servername = xprt->servername;
512 
513 	new = rpc_new_client(args, xprt);
514 	if (IS_ERR(new)) {
515 		err = PTR_ERR(new);
516 		goto out_err;
517 	}
518 
519 	atomic_inc(&clnt->cl_count);
520 	new->cl_parent = clnt;
521 
522 	/* Turn off autobind on clones */
523 	new->cl_autobind = 0;
524 	new->cl_softrtry = clnt->cl_softrtry;
525 	new->cl_discrtry = clnt->cl_discrtry;
526 	new->cl_chatty = clnt->cl_chatty;
527 	return new;
528 
529 out_err:
530 	dprintk("RPC:       %s: returned error %d\n", __func__, err);
531 	return ERR_PTR(err);
532 }
533 
534 /**
535  * rpc_clone_client - Clone an RPC client structure
536  *
537  * @clnt: RPC client whose parameters are copied
538  *
539  * Returns a fresh RPC client or an ERR_PTR.
540  */
rpc_clone_client(struct rpc_clnt * clnt)541 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
542 {
543 	struct rpc_create_args args = {
544 		.program	= clnt->cl_program,
545 		.prognumber	= clnt->cl_prog,
546 		.version	= clnt->cl_vers,
547 		.authflavor	= clnt->cl_auth->au_flavor,
548 		.client_name	= clnt->cl_principal,
549 	};
550 	return __rpc_clone_client(&args, clnt);
551 }
552 EXPORT_SYMBOL_GPL(rpc_clone_client);
553 
554 /**
555  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
556  *
557  * @clnt: RPC client whose parameters are copied
558  * @flavor: security flavor for new client
559  *
560  * Returns a fresh RPC client or an ERR_PTR.
561  */
562 struct rpc_clnt *
rpc_clone_client_set_auth(struct rpc_clnt * clnt,rpc_authflavor_t flavor)563 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
564 {
565 	struct rpc_create_args args = {
566 		.program	= clnt->cl_program,
567 		.prognumber	= clnt->cl_prog,
568 		.version	= clnt->cl_vers,
569 		.authflavor	= flavor,
570 		.client_name	= clnt->cl_principal,
571 	};
572 	return __rpc_clone_client(&args, clnt);
573 }
574 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
575 
576 /*
577  * Kill all tasks for the given client.
578  * XXX: kill their descendants as well?
579  */
rpc_killall_tasks(struct rpc_clnt * clnt)580 void rpc_killall_tasks(struct rpc_clnt *clnt)
581 {
582 	struct rpc_task	*rovr;
583 
584 
585 	if (list_empty(&clnt->cl_tasks))
586 		return;
587 	dprintk("RPC:       killing all tasks for client %p\n", clnt);
588 	/*
589 	 * Spin lock all_tasks to prevent changes...
590 	 */
591 	spin_lock(&clnt->cl_lock);
592 	list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
593 		if (!RPC_IS_ACTIVATED(rovr))
594 			continue;
595 		if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
596 			rovr->tk_flags |= RPC_TASK_KILLED;
597 			rpc_exit(rovr, -EIO);
598 			if (RPC_IS_QUEUED(rovr))
599 				rpc_wake_up_queued_task(rovr->tk_waitqueue,
600 							rovr);
601 		}
602 	}
603 	spin_unlock(&clnt->cl_lock);
604 }
605 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
606 
607 /*
608  * Properly shut down an RPC client, terminating all outstanding
609  * requests.
610  */
rpc_shutdown_client(struct rpc_clnt * clnt)611 void rpc_shutdown_client(struct rpc_clnt *clnt)
612 {
613 	might_sleep();
614 
615 	dprintk_rcu("RPC:       shutting down %s client for %s\n",
616 			clnt->cl_protname,
617 			rcu_dereference(clnt->cl_xprt)->servername);
618 
619 	while (!list_empty(&clnt->cl_tasks)) {
620 		rpc_killall_tasks(clnt);
621 		wait_event_timeout(destroy_wait,
622 			list_empty(&clnt->cl_tasks), 1*HZ);
623 	}
624 
625 	rpc_release_client(clnt);
626 }
627 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
628 
629 /*
630  * Free an RPC client
631  */
632 static void
rpc_free_client(struct rpc_clnt * clnt)633 rpc_free_client(struct rpc_clnt *clnt)
634 {
635 	dprintk_rcu("RPC:       destroying %s client for %s\n",
636 			clnt->cl_protname,
637 			rcu_dereference(clnt->cl_xprt)->servername);
638 	if (clnt->cl_parent != clnt)
639 		rpc_release_client(clnt->cl_parent);
640 	rpc_unregister_client(clnt);
641 	rpc_clnt_remove_pipedir(clnt);
642 	rpc_free_iostats(clnt->cl_metrics);
643 	kfree(clnt->cl_principal);
644 	clnt->cl_metrics = NULL;
645 	xprt_put(rcu_dereference_raw(clnt->cl_xprt));
646 	rpciod_down();
647 	kfree(clnt);
648 }
649 
650 /*
651  * Free an RPC client
652  */
653 static void
rpc_free_auth(struct rpc_clnt * clnt)654 rpc_free_auth(struct rpc_clnt *clnt)
655 {
656 	if (clnt->cl_auth == NULL) {
657 		rpc_free_client(clnt);
658 		return;
659 	}
660 
661 	/*
662 	 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
663 	 *       release remaining GSS contexts. This mechanism ensures
664 	 *       that it can do so safely.
665 	 */
666 	atomic_inc(&clnt->cl_count);
667 	rpcauth_release(clnt->cl_auth);
668 	clnt->cl_auth = NULL;
669 	if (atomic_dec_and_test(&clnt->cl_count))
670 		rpc_free_client(clnt);
671 }
672 
673 /*
674  * Release reference to the RPC client
675  */
676 void
rpc_release_client(struct rpc_clnt * clnt)677 rpc_release_client(struct rpc_clnt *clnt)
678 {
679 	dprintk("RPC:       rpc_release_client(%p)\n", clnt);
680 
681 	if (list_empty(&clnt->cl_tasks))
682 		wake_up(&destroy_wait);
683 	if (atomic_dec_and_test(&clnt->cl_count))
684 		rpc_free_auth(clnt);
685 }
686 EXPORT_SYMBOL_GPL(rpc_release_client);
687 
688 /**
689  * rpc_bind_new_program - bind a new RPC program to an existing client
690  * @old: old rpc_client
691  * @program: rpc program to set
692  * @vers: rpc program version
693  *
694  * Clones the rpc client and sets up a new RPC program. This is mainly
695  * of use for enabling different RPC programs to share the same transport.
696  * The Sun NFSv2/v3 ACL protocol can do this.
697  */
rpc_bind_new_program(struct rpc_clnt * old,const struct rpc_program * program,u32 vers)698 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
699 				      const struct rpc_program *program,
700 				      u32 vers)
701 {
702 	struct rpc_create_args args = {
703 		.program	= program,
704 		.prognumber	= program->number,
705 		.version	= vers,
706 		.authflavor	= old->cl_auth->au_flavor,
707 		.client_name	= old->cl_principal,
708 	};
709 	struct rpc_clnt *clnt;
710 	int err;
711 
712 	clnt = __rpc_clone_client(&args, old);
713 	if (IS_ERR(clnt))
714 		goto out;
715 	err = rpc_ping(clnt);
716 	if (err != 0) {
717 		rpc_shutdown_client(clnt);
718 		clnt = ERR_PTR(err);
719 	}
720 out:
721 	return clnt;
722 }
723 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
724 
rpc_task_release_client(struct rpc_task * task)725 void rpc_task_release_client(struct rpc_task *task)
726 {
727 	struct rpc_clnt *clnt = task->tk_client;
728 
729 	if (clnt != NULL) {
730 		/* Remove from client task list */
731 		spin_lock(&clnt->cl_lock);
732 		list_del(&task->tk_task);
733 		spin_unlock(&clnt->cl_lock);
734 		task->tk_client = NULL;
735 
736 		rpc_release_client(clnt);
737 	}
738 }
739 
740 static
rpc_task_set_client(struct rpc_task * task,struct rpc_clnt * clnt)741 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
742 {
743 	if (clnt != NULL) {
744 		rpc_task_release_client(task);
745 		task->tk_client = clnt;
746 		atomic_inc(&clnt->cl_count);
747 		if (clnt->cl_softrtry)
748 			task->tk_flags |= RPC_TASK_SOFT;
749 		if (sk_memalloc_socks()) {
750 			struct rpc_xprt *xprt;
751 
752 			rcu_read_lock();
753 			xprt = rcu_dereference(clnt->cl_xprt);
754 			if (xprt->swapper)
755 				task->tk_flags |= RPC_TASK_SWAPPER;
756 			rcu_read_unlock();
757 		}
758 		/* Add to the client's list of all tasks */
759 		spin_lock(&clnt->cl_lock);
760 		list_add_tail(&task->tk_task, &clnt->cl_tasks);
761 		spin_unlock(&clnt->cl_lock);
762 	}
763 }
764 
rpc_task_reset_client(struct rpc_task * task,struct rpc_clnt * clnt)765 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
766 {
767 	rpc_task_release_client(task);
768 	rpc_task_set_client(task, clnt);
769 }
770 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
771 
772 
773 static void
rpc_task_set_rpc_message(struct rpc_task * task,const struct rpc_message * msg)774 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
775 {
776 	if (msg != NULL) {
777 		task->tk_msg.rpc_proc = msg->rpc_proc;
778 		task->tk_msg.rpc_argp = msg->rpc_argp;
779 		task->tk_msg.rpc_resp = msg->rpc_resp;
780 		if (msg->rpc_cred != NULL)
781 			task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
782 	}
783 }
784 
785 /*
786  * Default callback for async RPC calls
787  */
788 static void
rpc_default_callback(struct rpc_task * task,void * data)789 rpc_default_callback(struct rpc_task *task, void *data)
790 {
791 }
792 
793 static const struct rpc_call_ops rpc_default_ops = {
794 	.rpc_call_done = rpc_default_callback,
795 };
796 
797 /**
798  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
799  * @task_setup_data: pointer to task initialisation data
800  */
rpc_run_task(const struct rpc_task_setup * task_setup_data)801 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
802 {
803 	struct rpc_task *task;
804 
805 	task = rpc_new_task(task_setup_data);
806 	if (IS_ERR(task))
807 		goto out;
808 
809 	rpc_task_set_client(task, task_setup_data->rpc_client);
810 	rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
811 
812 	if (task->tk_action == NULL)
813 		rpc_call_start(task);
814 
815 	atomic_inc(&task->tk_count);
816 	rpc_execute(task);
817 out:
818 	return task;
819 }
820 EXPORT_SYMBOL_GPL(rpc_run_task);
821 
822 /**
823  * rpc_call_sync - Perform a synchronous RPC call
824  * @clnt: pointer to RPC client
825  * @msg: RPC call parameters
826  * @flags: RPC call flags
827  */
rpc_call_sync(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags)828 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
829 {
830 	struct rpc_task	*task;
831 	struct rpc_task_setup task_setup_data = {
832 		.rpc_client = clnt,
833 		.rpc_message = msg,
834 		.callback_ops = &rpc_default_ops,
835 		.flags = flags,
836 	};
837 	int status;
838 
839 	WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
840 	if (flags & RPC_TASK_ASYNC) {
841 		rpc_release_calldata(task_setup_data.callback_ops,
842 			task_setup_data.callback_data);
843 		return -EINVAL;
844 	}
845 
846 	task = rpc_run_task(&task_setup_data);
847 	if (IS_ERR(task))
848 		return PTR_ERR(task);
849 	status = task->tk_status;
850 	rpc_put_task(task);
851 	return status;
852 }
853 EXPORT_SYMBOL_GPL(rpc_call_sync);
854 
855 /**
856  * rpc_call_async - Perform an asynchronous RPC call
857  * @clnt: pointer to RPC client
858  * @msg: RPC call parameters
859  * @flags: RPC call flags
860  * @tk_ops: RPC call ops
861  * @data: user call data
862  */
863 int
rpc_call_async(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags,const struct rpc_call_ops * tk_ops,void * data)864 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
865 	       const struct rpc_call_ops *tk_ops, void *data)
866 {
867 	struct rpc_task	*task;
868 	struct rpc_task_setup task_setup_data = {
869 		.rpc_client = clnt,
870 		.rpc_message = msg,
871 		.callback_ops = tk_ops,
872 		.callback_data = data,
873 		.flags = flags|RPC_TASK_ASYNC,
874 	};
875 
876 	task = rpc_run_task(&task_setup_data);
877 	if (IS_ERR(task))
878 		return PTR_ERR(task);
879 	rpc_put_task(task);
880 	return 0;
881 }
882 EXPORT_SYMBOL_GPL(rpc_call_async);
883 
884 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
885 /**
886  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
887  * rpc_execute against it
888  * @req: RPC request
889  * @tk_ops: RPC call ops
890  */
rpc_run_bc_task(struct rpc_rqst * req,const struct rpc_call_ops * tk_ops)891 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
892 				const struct rpc_call_ops *tk_ops)
893 {
894 	struct rpc_task *task;
895 	struct xdr_buf *xbufp = &req->rq_snd_buf;
896 	struct rpc_task_setup task_setup_data = {
897 		.callback_ops = tk_ops,
898 	};
899 
900 	dprintk("RPC: rpc_run_bc_task req= %p\n", req);
901 	/*
902 	 * Create an rpc_task to send the data
903 	 */
904 	task = rpc_new_task(&task_setup_data);
905 	if (IS_ERR(task)) {
906 		xprt_free_bc_request(req);
907 		goto out;
908 	}
909 	task->tk_rqstp = req;
910 
911 	/*
912 	 * Set up the xdr_buf length.
913 	 * This also indicates that the buffer is XDR encoded already.
914 	 */
915 	xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
916 			xbufp->tail[0].iov_len;
917 
918 	task->tk_action = call_bc_transmit;
919 	atomic_inc(&task->tk_count);
920 	WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
921 	rpc_execute(task);
922 
923 out:
924 	dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
925 	return task;
926 }
927 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
928 
929 void
rpc_call_start(struct rpc_task * task)930 rpc_call_start(struct rpc_task *task)
931 {
932 	task->tk_action = call_start;
933 }
934 EXPORT_SYMBOL_GPL(rpc_call_start);
935 
936 /**
937  * rpc_peeraddr - extract remote peer address from clnt's xprt
938  * @clnt: RPC client structure
939  * @buf: target buffer
940  * @bufsize: length of target buffer
941  *
942  * Returns the number of bytes that are actually in the stored address.
943  */
rpc_peeraddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t bufsize)944 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
945 {
946 	size_t bytes;
947 	struct rpc_xprt *xprt;
948 
949 	rcu_read_lock();
950 	xprt = rcu_dereference(clnt->cl_xprt);
951 
952 	bytes = xprt->addrlen;
953 	if (bytes > bufsize)
954 		bytes = bufsize;
955 	memcpy(buf, &xprt->addr, bytes);
956 	rcu_read_unlock();
957 
958 	return bytes;
959 }
960 EXPORT_SYMBOL_GPL(rpc_peeraddr);
961 
962 /**
963  * rpc_peeraddr2str - return remote peer address in printable format
964  * @clnt: RPC client structure
965  * @format: address format
966  *
967  * NB: the lifetime of the memory referenced by the returned pointer is
968  * the same as the rpc_xprt itself.  As long as the caller uses this
969  * pointer, it must hold the RCU read lock.
970  */
rpc_peeraddr2str(struct rpc_clnt * clnt,enum rpc_display_format_t format)971 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
972 			     enum rpc_display_format_t format)
973 {
974 	struct rpc_xprt *xprt;
975 
976 	xprt = rcu_dereference(clnt->cl_xprt);
977 
978 	if (xprt->address_strings[format] != NULL)
979 		return xprt->address_strings[format];
980 	else
981 		return "unprintable";
982 }
983 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
984 
985 static const struct sockaddr_in rpc_inaddr_loopback = {
986 	.sin_family		= AF_INET,
987 	.sin_addr.s_addr	= htonl(INADDR_ANY),
988 };
989 
990 static const struct sockaddr_in6 rpc_in6addr_loopback = {
991 	.sin6_family		= AF_INET6,
992 	.sin6_addr		= IN6ADDR_ANY_INIT,
993 };
994 
995 /*
996  * Try a getsockname() on a connected datagram socket.  Using a
997  * connected datagram socket prevents leaving a socket in TIME_WAIT.
998  * This conserves the ephemeral port number space.
999  *
1000  * Returns zero and fills in "buf" if successful; otherwise, a
1001  * negative errno is returned.
1002  */
rpc_sockname(struct net * net,struct sockaddr * sap,size_t salen,struct sockaddr * buf,int buflen)1003 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1004 			struct sockaddr *buf, int buflen)
1005 {
1006 	struct socket *sock;
1007 	int err;
1008 
1009 	err = __sock_create(net, sap->sa_family,
1010 				SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1011 	if (err < 0) {
1012 		dprintk("RPC:       can't create UDP socket (%d)\n", err);
1013 		goto out;
1014 	}
1015 
1016 	switch (sap->sa_family) {
1017 	case AF_INET:
1018 		err = kernel_bind(sock,
1019 				(struct sockaddr *)&rpc_inaddr_loopback,
1020 				sizeof(rpc_inaddr_loopback));
1021 		break;
1022 	case AF_INET6:
1023 		err = kernel_bind(sock,
1024 				(struct sockaddr *)&rpc_in6addr_loopback,
1025 				sizeof(rpc_in6addr_loopback));
1026 		break;
1027 	default:
1028 		err = -EAFNOSUPPORT;
1029 		goto out;
1030 	}
1031 	if (err < 0) {
1032 		dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1033 		goto out_release;
1034 	}
1035 
1036 	err = kernel_connect(sock, sap, salen, 0);
1037 	if (err < 0) {
1038 		dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1039 		goto out_release;
1040 	}
1041 
1042 	err = kernel_getsockname(sock, buf, &buflen);
1043 	if (err < 0) {
1044 		dprintk("RPC:       getsockname failed (%d)\n", err);
1045 		goto out_release;
1046 	}
1047 
1048 	err = 0;
1049 	if (buf->sa_family == AF_INET6) {
1050 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1051 		sin6->sin6_scope_id = 0;
1052 	}
1053 	dprintk("RPC:       %s succeeded\n", __func__);
1054 
1055 out_release:
1056 	sock_release(sock);
1057 out:
1058 	return err;
1059 }
1060 
1061 /*
1062  * Scraping a connected socket failed, so we don't have a useable
1063  * local address.  Fallback: generate an address that will prevent
1064  * the server from calling us back.
1065  *
1066  * Returns zero and fills in "buf" if successful; otherwise, a
1067  * negative errno is returned.
1068  */
rpc_anyaddr(int family,struct sockaddr * buf,size_t buflen)1069 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1070 {
1071 	switch (family) {
1072 	case AF_INET:
1073 		if (buflen < sizeof(rpc_inaddr_loopback))
1074 			return -EINVAL;
1075 		memcpy(buf, &rpc_inaddr_loopback,
1076 				sizeof(rpc_inaddr_loopback));
1077 		break;
1078 	case AF_INET6:
1079 		if (buflen < sizeof(rpc_in6addr_loopback))
1080 			return -EINVAL;
1081 		memcpy(buf, &rpc_in6addr_loopback,
1082 				sizeof(rpc_in6addr_loopback));
1083 	default:
1084 		dprintk("RPC:       %s: address family not supported\n",
1085 			__func__);
1086 		return -EAFNOSUPPORT;
1087 	}
1088 	dprintk("RPC:       %s: succeeded\n", __func__);
1089 	return 0;
1090 }
1091 
1092 /**
1093  * rpc_localaddr - discover local endpoint address for an RPC client
1094  * @clnt: RPC client structure
1095  * @buf: target buffer
1096  * @buflen: size of target buffer, in bytes
1097  *
1098  * Returns zero and fills in "buf" and "buflen" if successful;
1099  * otherwise, a negative errno is returned.
1100  *
1101  * This works even if the underlying transport is not currently connected,
1102  * or if the upper layer never previously provided a source address.
1103  *
1104  * The result of this function call is transient: multiple calls in
1105  * succession may give different results, depending on how local
1106  * networking configuration changes over time.
1107  */
rpc_localaddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t buflen)1108 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1109 {
1110 	struct sockaddr_storage address;
1111 	struct sockaddr *sap = (struct sockaddr *)&address;
1112 	struct rpc_xprt *xprt;
1113 	struct net *net;
1114 	size_t salen;
1115 	int err;
1116 
1117 	rcu_read_lock();
1118 	xprt = rcu_dereference(clnt->cl_xprt);
1119 	salen = xprt->addrlen;
1120 	memcpy(sap, &xprt->addr, salen);
1121 	net = get_net(xprt->xprt_net);
1122 	rcu_read_unlock();
1123 
1124 	rpc_set_port(sap, 0);
1125 	err = rpc_sockname(net, sap, salen, buf, buflen);
1126 	put_net(net);
1127 	if (err != 0)
1128 		/* Couldn't discover local address, return ANYADDR */
1129 		return rpc_anyaddr(sap->sa_family, buf, buflen);
1130 	return 0;
1131 }
1132 EXPORT_SYMBOL_GPL(rpc_localaddr);
1133 
1134 void
rpc_setbufsize(struct rpc_clnt * clnt,unsigned int sndsize,unsigned int rcvsize)1135 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1136 {
1137 	struct rpc_xprt *xprt;
1138 
1139 	rcu_read_lock();
1140 	xprt = rcu_dereference(clnt->cl_xprt);
1141 	if (xprt->ops->set_buffer_size)
1142 		xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1143 	rcu_read_unlock();
1144 }
1145 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1146 
1147 /**
1148  * rpc_protocol - Get transport protocol number for an RPC client
1149  * @clnt: RPC client to query
1150  *
1151  */
rpc_protocol(struct rpc_clnt * clnt)1152 int rpc_protocol(struct rpc_clnt *clnt)
1153 {
1154 	int protocol;
1155 
1156 	rcu_read_lock();
1157 	protocol = rcu_dereference(clnt->cl_xprt)->prot;
1158 	rcu_read_unlock();
1159 	return protocol;
1160 }
1161 EXPORT_SYMBOL_GPL(rpc_protocol);
1162 
1163 /**
1164  * rpc_net_ns - Get the network namespace for this RPC client
1165  * @clnt: RPC client to query
1166  *
1167  */
rpc_net_ns(struct rpc_clnt * clnt)1168 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1169 {
1170 	struct net *ret;
1171 
1172 	rcu_read_lock();
1173 	ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1174 	rcu_read_unlock();
1175 	return ret;
1176 }
1177 EXPORT_SYMBOL_GPL(rpc_net_ns);
1178 
1179 /**
1180  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1181  * @clnt: RPC client to query
1182  *
1183  * For stream transports, this is one RPC record fragment (see RFC
1184  * 1831), as we don't support multi-record requests yet.  For datagram
1185  * transports, this is the size of an IP packet minus the IP, UDP, and
1186  * RPC header sizes.
1187  */
rpc_max_payload(struct rpc_clnt * clnt)1188 size_t rpc_max_payload(struct rpc_clnt *clnt)
1189 {
1190 	size_t ret;
1191 
1192 	rcu_read_lock();
1193 	ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1194 	rcu_read_unlock();
1195 	return ret;
1196 }
1197 EXPORT_SYMBOL_GPL(rpc_max_payload);
1198 
1199 /**
1200  * rpc_get_timeout - Get timeout for transport in units of HZ
1201  * @clnt: RPC client to query
1202  */
rpc_get_timeout(struct rpc_clnt * clnt)1203 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1204 {
1205 	unsigned long ret;
1206 
1207 	rcu_read_lock();
1208 	ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1209 	rcu_read_unlock();
1210 	return ret;
1211 }
1212 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1213 
1214 /**
1215  * rpc_force_rebind - force transport to check that remote port is unchanged
1216  * @clnt: client to rebind
1217  *
1218  */
rpc_force_rebind(struct rpc_clnt * clnt)1219 void rpc_force_rebind(struct rpc_clnt *clnt)
1220 {
1221 	if (clnt->cl_autobind) {
1222 		rcu_read_lock();
1223 		xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1224 		rcu_read_unlock();
1225 	}
1226 }
1227 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1228 
1229 /*
1230  * Restart an (async) RPC call from the call_prepare state.
1231  * Usually called from within the exit handler.
1232  */
1233 int
rpc_restart_call_prepare(struct rpc_task * task)1234 rpc_restart_call_prepare(struct rpc_task *task)
1235 {
1236 	if (RPC_ASSASSINATED(task))
1237 		return 0;
1238 	task->tk_action = call_start;
1239 	if (task->tk_ops->rpc_call_prepare != NULL)
1240 		task->tk_action = rpc_prepare_task;
1241 	return 1;
1242 }
1243 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1244 
1245 /*
1246  * Restart an (async) RPC call. Usually called from within the
1247  * exit handler.
1248  */
1249 int
rpc_restart_call(struct rpc_task * task)1250 rpc_restart_call(struct rpc_task *task)
1251 {
1252 	if (RPC_ASSASSINATED(task))
1253 		return 0;
1254 	task->tk_action = call_start;
1255 	return 1;
1256 }
1257 EXPORT_SYMBOL_GPL(rpc_restart_call);
1258 
1259 #ifdef RPC_DEBUG
rpc_proc_name(const struct rpc_task * task)1260 static const char *rpc_proc_name(const struct rpc_task *task)
1261 {
1262 	const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1263 
1264 	if (proc) {
1265 		if (proc->p_name)
1266 			return proc->p_name;
1267 		else
1268 			return "NULL";
1269 	} else
1270 		return "no proc";
1271 }
1272 #endif
1273 
1274 /*
1275  * 0.  Initial state
1276  *
1277  *     Other FSM states can be visited zero or more times, but
1278  *     this state is visited exactly once for each RPC.
1279  */
1280 static void
call_start(struct rpc_task * task)1281 call_start(struct rpc_task *task)
1282 {
1283 	struct rpc_clnt	*clnt = task->tk_client;
1284 
1285 	dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1286 			clnt->cl_protname, clnt->cl_vers,
1287 			rpc_proc_name(task),
1288 			(RPC_IS_ASYNC(task) ? "async" : "sync"));
1289 
1290 	/* Increment call count */
1291 	task->tk_msg.rpc_proc->p_count++;
1292 	clnt->cl_stats->rpccnt++;
1293 	task->tk_action = call_reserve;
1294 }
1295 
1296 /*
1297  * 1.	Reserve an RPC call slot
1298  */
1299 static void
call_reserve(struct rpc_task * task)1300 call_reserve(struct rpc_task *task)
1301 {
1302 	dprint_status(task);
1303 
1304 	task->tk_status  = 0;
1305 	task->tk_action  = call_reserveresult;
1306 	xprt_reserve(task);
1307 }
1308 
1309 static void call_retry_reserve(struct rpc_task *task);
1310 
1311 /*
1312  * 1b.	Grok the result of xprt_reserve()
1313  */
1314 static void
call_reserveresult(struct rpc_task * task)1315 call_reserveresult(struct rpc_task *task)
1316 {
1317 	int status = task->tk_status;
1318 
1319 	dprint_status(task);
1320 
1321 	/*
1322 	 * After a call to xprt_reserve(), we must have either
1323 	 * a request slot or else an error status.
1324 	 */
1325 	task->tk_status = 0;
1326 	if (status >= 0) {
1327 		if (task->tk_rqstp) {
1328 			task->tk_action = call_refresh;
1329 			return;
1330 		}
1331 
1332 		printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1333 				__func__, status);
1334 		rpc_exit(task, -EIO);
1335 		return;
1336 	}
1337 
1338 	/*
1339 	 * Even though there was an error, we may have acquired
1340 	 * a request slot somehow.  Make sure not to leak it.
1341 	 */
1342 	if (task->tk_rqstp) {
1343 		printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1344 				__func__, status);
1345 		xprt_release(task);
1346 	}
1347 
1348 	switch (status) {
1349 	case -ENOMEM:
1350 		rpc_delay(task, HZ >> 2);
1351 	case -EAGAIN:	/* woken up; retry */
1352 		task->tk_action = call_retry_reserve;
1353 		return;
1354 	case -EIO:	/* probably a shutdown */
1355 		break;
1356 	default:
1357 		printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1358 				__func__, status);
1359 		break;
1360 	}
1361 	rpc_exit(task, status);
1362 }
1363 
1364 /*
1365  * 1c.	Retry reserving an RPC call slot
1366  */
1367 static void
call_retry_reserve(struct rpc_task * task)1368 call_retry_reserve(struct rpc_task *task)
1369 {
1370 	dprint_status(task);
1371 
1372 	task->tk_status  = 0;
1373 	task->tk_action  = call_reserveresult;
1374 	xprt_retry_reserve(task);
1375 }
1376 
1377 /*
1378  * 2.	Bind and/or refresh the credentials
1379  */
1380 static void
call_refresh(struct rpc_task * task)1381 call_refresh(struct rpc_task *task)
1382 {
1383 	dprint_status(task);
1384 
1385 	task->tk_action = call_refreshresult;
1386 	task->tk_status = 0;
1387 	task->tk_client->cl_stats->rpcauthrefresh++;
1388 	rpcauth_refreshcred(task);
1389 }
1390 
1391 /*
1392  * 2a.	Process the results of a credential refresh
1393  */
1394 static void
call_refreshresult(struct rpc_task * task)1395 call_refreshresult(struct rpc_task *task)
1396 {
1397 	int status = task->tk_status;
1398 
1399 	dprint_status(task);
1400 
1401 	task->tk_status = 0;
1402 	task->tk_action = call_refresh;
1403 	switch (status) {
1404 	case 0:
1405 		if (rpcauth_uptodatecred(task))
1406 			task->tk_action = call_allocate;
1407 		return;
1408 	case -ETIMEDOUT:
1409 		rpc_delay(task, 3*HZ);
1410 	case -EKEYEXPIRED:
1411 	case -EAGAIN:
1412 		status = -EACCES;
1413 		if (!task->tk_cred_retry)
1414 			break;
1415 		task->tk_cred_retry--;
1416 		dprintk("RPC: %5u %s: retry refresh creds\n",
1417 				task->tk_pid, __func__);
1418 		return;
1419 	}
1420 	dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1421 				task->tk_pid, __func__, status);
1422 	rpc_exit(task, status);
1423 }
1424 
1425 /*
1426  * 2b.	Allocate the buffer. For details, see sched.c:rpc_malloc.
1427  *	(Note: buffer memory is freed in xprt_release).
1428  */
1429 static void
call_allocate(struct rpc_task * task)1430 call_allocate(struct rpc_task *task)
1431 {
1432 	unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1433 	struct rpc_rqst *req = task->tk_rqstp;
1434 	struct rpc_xprt *xprt = req->rq_xprt;
1435 	struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1436 
1437 	dprint_status(task);
1438 
1439 	task->tk_status = 0;
1440 	task->tk_action = call_bind;
1441 
1442 	if (req->rq_buffer)
1443 		return;
1444 
1445 	if (proc->p_proc != 0) {
1446 		BUG_ON(proc->p_arglen == 0);
1447 		if (proc->p_decode != NULL)
1448 			BUG_ON(proc->p_replen == 0);
1449 	}
1450 
1451 	/*
1452 	 * Calculate the size (in quads) of the RPC call
1453 	 * and reply headers, and convert both values
1454 	 * to byte sizes.
1455 	 */
1456 	req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1457 	req->rq_callsize <<= 2;
1458 	req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1459 	req->rq_rcvsize <<= 2;
1460 
1461 	req->rq_buffer = xprt->ops->buf_alloc(task,
1462 					req->rq_callsize + req->rq_rcvsize);
1463 	if (req->rq_buffer != NULL)
1464 		return;
1465 
1466 	dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1467 
1468 	if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1469 		task->tk_action = call_allocate;
1470 		rpc_delay(task, HZ>>4);
1471 		return;
1472 	}
1473 
1474 	rpc_exit(task, -ERESTARTSYS);
1475 }
1476 
1477 static inline int
rpc_task_need_encode(struct rpc_task * task)1478 rpc_task_need_encode(struct rpc_task *task)
1479 {
1480 	return task->tk_rqstp->rq_snd_buf.len == 0;
1481 }
1482 
1483 static inline void
rpc_task_force_reencode(struct rpc_task * task)1484 rpc_task_force_reencode(struct rpc_task *task)
1485 {
1486 	task->tk_rqstp->rq_snd_buf.len = 0;
1487 	task->tk_rqstp->rq_bytes_sent = 0;
1488 }
1489 
1490 static inline void
rpc_xdr_buf_init(struct xdr_buf * buf,void * start,size_t len)1491 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1492 {
1493 	buf->head[0].iov_base = start;
1494 	buf->head[0].iov_len = len;
1495 	buf->tail[0].iov_len = 0;
1496 	buf->page_len = 0;
1497 	buf->flags = 0;
1498 	buf->len = 0;
1499 	buf->buflen = len;
1500 }
1501 
1502 /*
1503  * 3.	Encode arguments of an RPC call
1504  */
1505 static void
rpc_xdr_encode(struct rpc_task * task)1506 rpc_xdr_encode(struct rpc_task *task)
1507 {
1508 	struct rpc_rqst	*req = task->tk_rqstp;
1509 	kxdreproc_t	encode;
1510 	__be32		*p;
1511 
1512 	dprint_status(task);
1513 
1514 	rpc_xdr_buf_init(&req->rq_snd_buf,
1515 			 req->rq_buffer,
1516 			 req->rq_callsize);
1517 	rpc_xdr_buf_init(&req->rq_rcv_buf,
1518 			 (char *)req->rq_buffer + req->rq_callsize,
1519 			 req->rq_rcvsize);
1520 
1521 	p = rpc_encode_header(task);
1522 	if (p == NULL) {
1523 		printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1524 		rpc_exit(task, -EIO);
1525 		return;
1526 	}
1527 
1528 	encode = task->tk_msg.rpc_proc->p_encode;
1529 	if (encode == NULL)
1530 		return;
1531 
1532 	task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1533 			task->tk_msg.rpc_argp);
1534 }
1535 
1536 /*
1537  * 4.	Get the server port number if not yet set
1538  */
1539 static void
call_bind(struct rpc_task * task)1540 call_bind(struct rpc_task *task)
1541 {
1542 	struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1543 
1544 	dprint_status(task);
1545 
1546 	task->tk_action = call_connect;
1547 	if (!xprt_bound(xprt)) {
1548 		task->tk_action = call_bind_status;
1549 		task->tk_timeout = xprt->bind_timeout;
1550 		xprt->ops->rpcbind(task);
1551 	}
1552 }
1553 
1554 /*
1555  * 4a.	Sort out bind result
1556  */
1557 static void
call_bind_status(struct rpc_task * task)1558 call_bind_status(struct rpc_task *task)
1559 {
1560 	int status = -EIO;
1561 
1562 	if (task->tk_status >= 0) {
1563 		dprint_status(task);
1564 		task->tk_status = 0;
1565 		task->tk_action = call_connect;
1566 		return;
1567 	}
1568 
1569 	trace_rpc_bind_status(task);
1570 	switch (task->tk_status) {
1571 	case -ENOMEM:
1572 		dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1573 		rpc_delay(task, HZ >> 2);
1574 		goto retry_timeout;
1575 	case -EACCES:
1576 		dprintk("RPC: %5u remote rpcbind: RPC program/version "
1577 				"unavailable\n", task->tk_pid);
1578 		/* fail immediately if this is an RPC ping */
1579 		if (task->tk_msg.rpc_proc->p_proc == 0) {
1580 			status = -EOPNOTSUPP;
1581 			break;
1582 		}
1583 		if (task->tk_rebind_retry == 0)
1584 			break;
1585 		task->tk_rebind_retry--;
1586 		rpc_delay(task, 3*HZ);
1587 		goto retry_timeout;
1588 	case -ETIMEDOUT:
1589 		dprintk("RPC: %5u rpcbind request timed out\n",
1590 				task->tk_pid);
1591 		goto retry_timeout;
1592 	case -EPFNOSUPPORT:
1593 		/* server doesn't support any rpcbind version we know of */
1594 		dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1595 				task->tk_pid);
1596 		break;
1597 	case -EPROTONOSUPPORT:
1598 		dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1599 				task->tk_pid);
1600 		task->tk_status = 0;
1601 		task->tk_action = call_bind;
1602 		return;
1603 	case -ECONNREFUSED:		/* connection problems */
1604 	case -ECONNRESET:
1605 	case -ENOTCONN:
1606 	case -EHOSTDOWN:
1607 	case -EHOSTUNREACH:
1608 	case -ENETUNREACH:
1609 	case -EPIPE:
1610 		dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1611 				task->tk_pid, task->tk_status);
1612 		if (!RPC_IS_SOFTCONN(task)) {
1613 			rpc_delay(task, 5*HZ);
1614 			goto retry_timeout;
1615 		}
1616 		status = task->tk_status;
1617 		break;
1618 	default:
1619 		dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1620 				task->tk_pid, -task->tk_status);
1621 	}
1622 
1623 	rpc_exit(task, status);
1624 	return;
1625 
1626 retry_timeout:
1627 	task->tk_action = call_timeout;
1628 }
1629 
1630 /*
1631  * 4b.	Connect to the RPC server
1632  */
1633 static void
call_connect(struct rpc_task * task)1634 call_connect(struct rpc_task *task)
1635 {
1636 	struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1637 
1638 	dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1639 			task->tk_pid, xprt,
1640 			(xprt_connected(xprt) ? "is" : "is not"));
1641 
1642 	task->tk_action = call_transmit;
1643 	if (!xprt_connected(xprt)) {
1644 		task->tk_action = call_connect_status;
1645 		if (task->tk_status < 0)
1646 			return;
1647 		xprt_connect(task);
1648 	}
1649 }
1650 
1651 /*
1652  * 4c.	Sort out connect result
1653  */
1654 static void
call_connect_status(struct rpc_task * task)1655 call_connect_status(struct rpc_task *task)
1656 {
1657 	struct rpc_clnt *clnt = task->tk_client;
1658 	int status = task->tk_status;
1659 
1660 	dprint_status(task);
1661 
1662 	trace_rpc_connect_status(task, status);
1663 	switch (status) {
1664 		/* if soft mounted, test if we've timed out */
1665 	case -ETIMEDOUT:
1666 		task->tk_action = call_timeout;
1667 		return;
1668 	case -ECONNREFUSED:
1669 	case -ECONNRESET:
1670 	case -ENETUNREACH:
1671 		if (RPC_IS_SOFTCONN(task))
1672 			break;
1673 		/* retry with existing socket, after a delay */
1674 	case 0:
1675 	case -EAGAIN:
1676 		task->tk_status = 0;
1677 		clnt->cl_stats->netreconn++;
1678 		task->tk_action = call_transmit;
1679 		return;
1680 	}
1681 	rpc_exit(task, status);
1682 }
1683 
1684 /*
1685  * 5.	Transmit the RPC request, and wait for reply
1686  */
1687 static void
call_transmit(struct rpc_task * task)1688 call_transmit(struct rpc_task *task)
1689 {
1690 	dprint_status(task);
1691 
1692 	task->tk_action = call_status;
1693 	if (task->tk_status < 0)
1694 		return;
1695 	task->tk_status = xprt_prepare_transmit(task);
1696 	if (task->tk_status != 0)
1697 		return;
1698 	task->tk_action = call_transmit_status;
1699 	/* Encode here so that rpcsec_gss can use correct sequence number. */
1700 	if (rpc_task_need_encode(task)) {
1701 		rpc_xdr_encode(task);
1702 		/* Did the encode result in an error condition? */
1703 		if (task->tk_status != 0) {
1704 			/* Was the error nonfatal? */
1705 			if (task->tk_status == -EAGAIN)
1706 				rpc_delay(task, HZ >> 4);
1707 			else
1708 				rpc_exit(task, task->tk_status);
1709 			return;
1710 		}
1711 	}
1712 	xprt_transmit(task);
1713 	if (task->tk_status < 0)
1714 		return;
1715 	/*
1716 	 * On success, ensure that we call xprt_end_transmit() before sleeping
1717 	 * in order to allow access to the socket to other RPC requests.
1718 	 */
1719 	call_transmit_status(task);
1720 	if (rpc_reply_expected(task))
1721 		return;
1722 	task->tk_action = rpc_exit_task;
1723 	rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1724 }
1725 
1726 /*
1727  * 5a.	Handle cleanup after a transmission
1728  */
1729 static void
call_transmit_status(struct rpc_task * task)1730 call_transmit_status(struct rpc_task *task)
1731 {
1732 	task->tk_action = call_status;
1733 
1734 	/*
1735 	 * Common case: success.  Force the compiler to put this
1736 	 * test first.
1737 	 */
1738 	if (task->tk_status == 0) {
1739 		xprt_end_transmit(task);
1740 		rpc_task_force_reencode(task);
1741 		return;
1742 	}
1743 
1744 	switch (task->tk_status) {
1745 	case -EAGAIN:
1746 		break;
1747 	default:
1748 		dprint_status(task);
1749 		xprt_end_transmit(task);
1750 		rpc_task_force_reencode(task);
1751 		break;
1752 		/*
1753 		 * Special cases: if we've been waiting on the
1754 		 * socket's write_space() callback, or if the
1755 		 * socket just returned a connection error,
1756 		 * then hold onto the transport lock.
1757 		 */
1758 	case -ECONNREFUSED:
1759 	case -EHOSTDOWN:
1760 	case -EHOSTUNREACH:
1761 	case -ENETUNREACH:
1762 		if (RPC_IS_SOFTCONN(task)) {
1763 			xprt_end_transmit(task);
1764 			rpc_exit(task, task->tk_status);
1765 			break;
1766 		}
1767 	case -ECONNRESET:
1768 	case -ENOTCONN:
1769 	case -EPIPE:
1770 		rpc_task_force_reencode(task);
1771 	}
1772 }
1773 
1774 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1775 /*
1776  * 5b.	Send the backchannel RPC reply.  On error, drop the reply.  In
1777  * addition, disconnect on connectivity errors.
1778  */
1779 static void
call_bc_transmit(struct rpc_task * task)1780 call_bc_transmit(struct rpc_task *task)
1781 {
1782 	struct rpc_rqst *req = task->tk_rqstp;
1783 
1784 	task->tk_status = xprt_prepare_transmit(task);
1785 	if (task->tk_status == -EAGAIN) {
1786 		/*
1787 		 * Could not reserve the transport. Try again after the
1788 		 * transport is released.
1789 		 */
1790 		task->tk_status = 0;
1791 		task->tk_action = call_bc_transmit;
1792 		return;
1793 	}
1794 
1795 	task->tk_action = rpc_exit_task;
1796 	if (task->tk_status < 0) {
1797 		printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1798 			"error: %d\n", task->tk_status);
1799 		return;
1800 	}
1801 
1802 	xprt_transmit(task);
1803 	xprt_end_transmit(task);
1804 	dprint_status(task);
1805 	switch (task->tk_status) {
1806 	case 0:
1807 		/* Success */
1808 		break;
1809 	case -EHOSTDOWN:
1810 	case -EHOSTUNREACH:
1811 	case -ENETUNREACH:
1812 	case -ETIMEDOUT:
1813 		/*
1814 		 * Problem reaching the server.  Disconnect and let the
1815 		 * forechannel reestablish the connection.  The server will
1816 		 * have to retransmit the backchannel request and we'll
1817 		 * reprocess it.  Since these ops are idempotent, there's no
1818 		 * need to cache our reply at this time.
1819 		 */
1820 		printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1821 			"error: %d\n", task->tk_status);
1822 		xprt_conditional_disconnect(req->rq_xprt,
1823 			req->rq_connect_cookie);
1824 		break;
1825 	default:
1826 		/*
1827 		 * We were unable to reply and will have to drop the
1828 		 * request.  The server should reconnect and retransmit.
1829 		 */
1830 		WARN_ON_ONCE(task->tk_status == -EAGAIN);
1831 		printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1832 			"error: %d\n", task->tk_status);
1833 		break;
1834 	}
1835 	rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1836 }
1837 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1838 
1839 /*
1840  * 6.	Sort out the RPC call status
1841  */
1842 static void
call_status(struct rpc_task * task)1843 call_status(struct rpc_task *task)
1844 {
1845 	struct rpc_clnt	*clnt = task->tk_client;
1846 	struct rpc_rqst	*req = task->tk_rqstp;
1847 	int		status;
1848 
1849 	if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1850 		task->tk_status = req->rq_reply_bytes_recvd;
1851 
1852 	dprint_status(task);
1853 
1854 	status = task->tk_status;
1855 	if (status >= 0) {
1856 		task->tk_action = call_decode;
1857 		return;
1858 	}
1859 
1860 	trace_rpc_call_status(task);
1861 	task->tk_status = 0;
1862 	switch(status) {
1863 	case -EHOSTDOWN:
1864 	case -EHOSTUNREACH:
1865 	case -ENETUNREACH:
1866 		/*
1867 		 * Delay any retries for 3 seconds, then handle as if it
1868 		 * were a timeout.
1869 		 */
1870 		rpc_delay(task, 3*HZ);
1871 	case -ETIMEDOUT:
1872 		task->tk_action = call_timeout;
1873 		if (task->tk_client->cl_discrtry)
1874 			xprt_conditional_disconnect(req->rq_xprt,
1875 					req->rq_connect_cookie);
1876 		break;
1877 	case -ECONNRESET:
1878 	case -ECONNREFUSED:
1879 		rpc_force_rebind(clnt);
1880 		rpc_delay(task, 3*HZ);
1881 	case -EPIPE:
1882 	case -ENOTCONN:
1883 		task->tk_action = call_bind;
1884 		break;
1885 	case -EAGAIN:
1886 		task->tk_action = call_transmit;
1887 		break;
1888 	case -EIO:
1889 		/* shutdown or soft timeout */
1890 		rpc_exit(task, status);
1891 		break;
1892 	default:
1893 		if (clnt->cl_chatty)
1894 			printk("%s: RPC call returned error %d\n",
1895 			       clnt->cl_protname, -status);
1896 		rpc_exit(task, status);
1897 	}
1898 }
1899 
1900 /*
1901  * 6a.	Handle RPC timeout
1902  * 	We do not release the request slot, so we keep using the
1903  *	same XID for all retransmits.
1904  */
1905 static void
call_timeout(struct rpc_task * task)1906 call_timeout(struct rpc_task *task)
1907 {
1908 	struct rpc_clnt	*clnt = task->tk_client;
1909 
1910 	if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1911 		dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1912 		goto retry;
1913 	}
1914 
1915 	dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1916 	task->tk_timeouts++;
1917 
1918 	if (RPC_IS_SOFTCONN(task)) {
1919 		rpc_exit(task, -ETIMEDOUT);
1920 		return;
1921 	}
1922 	if (RPC_IS_SOFT(task)) {
1923 		if (clnt->cl_chatty) {
1924 			rcu_read_lock();
1925 			printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1926 				clnt->cl_protname,
1927 				rcu_dereference(clnt->cl_xprt)->servername);
1928 			rcu_read_unlock();
1929 		}
1930 		if (task->tk_flags & RPC_TASK_TIMEOUT)
1931 			rpc_exit(task, -ETIMEDOUT);
1932 		else
1933 			rpc_exit(task, -EIO);
1934 		return;
1935 	}
1936 
1937 	if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1938 		task->tk_flags |= RPC_CALL_MAJORSEEN;
1939 		if (clnt->cl_chatty) {
1940 			rcu_read_lock();
1941 			printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1942 			clnt->cl_protname,
1943 			rcu_dereference(clnt->cl_xprt)->servername);
1944 			rcu_read_unlock();
1945 		}
1946 	}
1947 	rpc_force_rebind(clnt);
1948 	/*
1949 	 * Did our request time out due to an RPCSEC_GSS out-of-sequence
1950 	 * event? RFC2203 requires the server to drop all such requests.
1951 	 */
1952 	rpcauth_invalcred(task);
1953 
1954 retry:
1955 	clnt->cl_stats->rpcretrans++;
1956 	task->tk_action = call_bind;
1957 	task->tk_status = 0;
1958 }
1959 
1960 /*
1961  * 7.	Decode the RPC reply
1962  */
1963 static void
call_decode(struct rpc_task * task)1964 call_decode(struct rpc_task *task)
1965 {
1966 	struct rpc_clnt	*clnt = task->tk_client;
1967 	struct rpc_rqst	*req = task->tk_rqstp;
1968 	kxdrdproc_t	decode = task->tk_msg.rpc_proc->p_decode;
1969 	__be32		*p;
1970 
1971 	dprint_status(task);
1972 
1973 	if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1974 		if (clnt->cl_chatty) {
1975 			rcu_read_lock();
1976 			printk(KERN_NOTICE "%s: server %s OK\n",
1977 				clnt->cl_protname,
1978 				rcu_dereference(clnt->cl_xprt)->servername);
1979 			rcu_read_unlock();
1980 		}
1981 		task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1982 	}
1983 
1984 	/*
1985 	 * Ensure that we see all writes made by xprt_complete_rqst()
1986 	 * before it changed req->rq_reply_bytes_recvd.
1987 	 */
1988 	smp_rmb();
1989 	req->rq_rcv_buf.len = req->rq_private_buf.len;
1990 
1991 	/* Check that the softirq receive buffer is valid */
1992 	WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1993 				sizeof(req->rq_rcv_buf)) != 0);
1994 
1995 	if (req->rq_rcv_buf.len < 12) {
1996 		if (!RPC_IS_SOFT(task)) {
1997 			task->tk_action = call_bind;
1998 			clnt->cl_stats->rpcretrans++;
1999 			goto out_retry;
2000 		}
2001 		dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2002 				clnt->cl_protname, task->tk_status);
2003 		task->tk_action = call_timeout;
2004 		goto out_retry;
2005 	}
2006 
2007 	p = rpc_verify_header(task);
2008 	if (IS_ERR(p)) {
2009 		if (p == ERR_PTR(-EAGAIN))
2010 			goto out_retry;
2011 		return;
2012 	}
2013 
2014 	task->tk_action = rpc_exit_task;
2015 
2016 	if (decode) {
2017 		task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2018 						      task->tk_msg.rpc_resp);
2019 	}
2020 	dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2021 			task->tk_status);
2022 	return;
2023 out_retry:
2024 	task->tk_status = 0;
2025 	/* Note: rpc_verify_header() may have freed the RPC slot */
2026 	if (task->tk_rqstp == req) {
2027 		req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2028 		if (task->tk_client->cl_discrtry)
2029 			xprt_conditional_disconnect(req->rq_xprt,
2030 					req->rq_connect_cookie);
2031 	}
2032 }
2033 
2034 static __be32 *
rpc_encode_header(struct rpc_task * task)2035 rpc_encode_header(struct rpc_task *task)
2036 {
2037 	struct rpc_clnt *clnt = task->tk_client;
2038 	struct rpc_rqst	*req = task->tk_rqstp;
2039 	__be32		*p = req->rq_svec[0].iov_base;
2040 
2041 	/* FIXME: check buffer size? */
2042 
2043 	p = xprt_skip_transport_header(req->rq_xprt, p);
2044 	*p++ = req->rq_xid;		/* XID */
2045 	*p++ = htonl(RPC_CALL);		/* CALL */
2046 	*p++ = htonl(RPC_VERSION);	/* RPC version */
2047 	*p++ = htonl(clnt->cl_prog);	/* program number */
2048 	*p++ = htonl(clnt->cl_vers);	/* program version */
2049 	*p++ = htonl(task->tk_msg.rpc_proc->p_proc);	/* procedure */
2050 	p = rpcauth_marshcred(task, p);
2051 	req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2052 	return p;
2053 }
2054 
2055 static __be32 *
rpc_verify_header(struct rpc_task * task)2056 rpc_verify_header(struct rpc_task *task)
2057 {
2058 	struct rpc_clnt *clnt = task->tk_client;
2059 	struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2060 	int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2061 	__be32	*p = iov->iov_base;
2062 	u32 n;
2063 	int error = -EACCES;
2064 
2065 	if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2066 		/* RFC-1014 says that the representation of XDR data must be a
2067 		 * multiple of four bytes
2068 		 * - if it isn't pointer subtraction in the NFS client may give
2069 		 *   undefined results
2070 		 */
2071 		dprintk("RPC: %5u %s: XDR representation not a multiple of"
2072 		       " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2073 		       task->tk_rqstp->rq_rcv_buf.len);
2074 		goto out_eio;
2075 	}
2076 	if ((len -= 3) < 0)
2077 		goto out_overflow;
2078 
2079 	p += 1; /* skip XID */
2080 	if ((n = ntohl(*p++)) != RPC_REPLY) {
2081 		dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2082 			task->tk_pid, __func__, n);
2083 		goto out_garbage;
2084 	}
2085 
2086 	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2087 		if (--len < 0)
2088 			goto out_overflow;
2089 		switch ((n = ntohl(*p++))) {
2090 		case RPC_AUTH_ERROR:
2091 			break;
2092 		case RPC_MISMATCH:
2093 			dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2094 				task->tk_pid, __func__);
2095 			error = -EPROTONOSUPPORT;
2096 			goto out_err;
2097 		default:
2098 			dprintk("RPC: %5u %s: RPC call rejected, "
2099 				"unknown error: %x\n",
2100 				task->tk_pid, __func__, n);
2101 			goto out_eio;
2102 		}
2103 		if (--len < 0)
2104 			goto out_overflow;
2105 		switch ((n = ntohl(*p++))) {
2106 		case RPC_AUTH_REJECTEDCRED:
2107 		case RPC_AUTH_REJECTEDVERF:
2108 		case RPCSEC_GSS_CREDPROBLEM:
2109 		case RPCSEC_GSS_CTXPROBLEM:
2110 			if (!task->tk_cred_retry)
2111 				break;
2112 			task->tk_cred_retry--;
2113 			dprintk("RPC: %5u %s: retry stale creds\n",
2114 					task->tk_pid, __func__);
2115 			rpcauth_invalcred(task);
2116 			/* Ensure we obtain a new XID! */
2117 			xprt_release(task);
2118 			task->tk_action = call_reserve;
2119 			goto out_retry;
2120 		case RPC_AUTH_BADCRED:
2121 		case RPC_AUTH_BADVERF:
2122 			/* possibly garbled cred/verf? */
2123 			if (!task->tk_garb_retry)
2124 				break;
2125 			task->tk_garb_retry--;
2126 			dprintk("RPC: %5u %s: retry garbled creds\n",
2127 					task->tk_pid, __func__);
2128 			task->tk_action = call_bind;
2129 			goto out_retry;
2130 		case RPC_AUTH_TOOWEAK:
2131 			rcu_read_lock();
2132 			printk(KERN_NOTICE "RPC: server %s requires stronger "
2133 			       "authentication.\n",
2134 			       rcu_dereference(clnt->cl_xprt)->servername);
2135 			rcu_read_unlock();
2136 			break;
2137 		default:
2138 			dprintk("RPC: %5u %s: unknown auth error: %x\n",
2139 					task->tk_pid, __func__, n);
2140 			error = -EIO;
2141 		}
2142 		dprintk("RPC: %5u %s: call rejected %d\n",
2143 				task->tk_pid, __func__, n);
2144 		goto out_err;
2145 	}
2146 	if (!(p = rpcauth_checkverf(task, p))) {
2147 		dprintk("RPC: %5u %s: auth check failed\n",
2148 				task->tk_pid, __func__);
2149 		goto out_garbage;		/* bad verifier, retry */
2150 	}
2151 	len = p - (__be32 *)iov->iov_base - 1;
2152 	if (len < 0)
2153 		goto out_overflow;
2154 	switch ((n = ntohl(*p++))) {
2155 	case RPC_SUCCESS:
2156 		return p;
2157 	case RPC_PROG_UNAVAIL:
2158 		dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2159 				"by server %s\n", task->tk_pid, __func__,
2160 				(unsigned int)clnt->cl_prog,
2161 				rcu_dereference(clnt->cl_xprt)->servername);
2162 		error = -EPFNOSUPPORT;
2163 		goto out_err;
2164 	case RPC_PROG_MISMATCH:
2165 		dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2166 				"by server %s\n", task->tk_pid, __func__,
2167 				(unsigned int)clnt->cl_prog,
2168 				(unsigned int)clnt->cl_vers,
2169 				rcu_dereference(clnt->cl_xprt)->servername);
2170 		error = -EPROTONOSUPPORT;
2171 		goto out_err;
2172 	case RPC_PROC_UNAVAIL:
2173 		dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2174 				"version %u on server %s\n",
2175 				task->tk_pid, __func__,
2176 				rpc_proc_name(task),
2177 				clnt->cl_prog, clnt->cl_vers,
2178 				rcu_dereference(clnt->cl_xprt)->servername);
2179 		error = -EOPNOTSUPP;
2180 		goto out_err;
2181 	case RPC_GARBAGE_ARGS:
2182 		dprintk("RPC: %5u %s: server saw garbage\n",
2183 				task->tk_pid, __func__);
2184 		break;			/* retry */
2185 	default:
2186 		dprintk("RPC: %5u %s: server accept status: %x\n",
2187 				task->tk_pid, __func__, n);
2188 		/* Also retry */
2189 	}
2190 
2191 out_garbage:
2192 	clnt->cl_stats->rpcgarbage++;
2193 	if (task->tk_garb_retry) {
2194 		task->tk_garb_retry--;
2195 		dprintk("RPC: %5u %s: retrying\n",
2196 				task->tk_pid, __func__);
2197 		task->tk_action = call_bind;
2198 out_retry:
2199 		return ERR_PTR(-EAGAIN);
2200 	}
2201 out_eio:
2202 	error = -EIO;
2203 out_err:
2204 	rpc_exit(task, error);
2205 	dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2206 			__func__, error);
2207 	return ERR_PTR(error);
2208 out_overflow:
2209 	dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2210 			__func__);
2211 	goto out_garbage;
2212 }
2213 
rpcproc_encode_null(void * rqstp,struct xdr_stream * xdr,void * obj)2214 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2215 {
2216 }
2217 
rpcproc_decode_null(void * rqstp,struct xdr_stream * xdr,void * obj)2218 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2219 {
2220 	return 0;
2221 }
2222 
2223 static struct rpc_procinfo rpcproc_null = {
2224 	.p_encode = rpcproc_encode_null,
2225 	.p_decode = rpcproc_decode_null,
2226 };
2227 
rpc_ping(struct rpc_clnt * clnt)2228 static int rpc_ping(struct rpc_clnt *clnt)
2229 {
2230 	struct rpc_message msg = {
2231 		.rpc_proc = &rpcproc_null,
2232 	};
2233 	int err;
2234 	msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2235 	err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2236 	put_rpccred(msg.rpc_cred);
2237 	return err;
2238 }
2239 
rpc_call_null(struct rpc_clnt * clnt,struct rpc_cred * cred,int flags)2240 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2241 {
2242 	struct rpc_message msg = {
2243 		.rpc_proc = &rpcproc_null,
2244 		.rpc_cred = cred,
2245 	};
2246 	struct rpc_task_setup task_setup_data = {
2247 		.rpc_client = clnt,
2248 		.rpc_message = &msg,
2249 		.callback_ops = &rpc_default_ops,
2250 		.flags = flags,
2251 	};
2252 	return rpc_run_task(&task_setup_data);
2253 }
2254 EXPORT_SYMBOL_GPL(rpc_call_null);
2255 
2256 #ifdef RPC_DEBUG
rpc_show_header(void)2257 static void rpc_show_header(void)
2258 {
2259 	printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2260 		"-timeout ---ops--\n");
2261 }
2262 
rpc_show_task(const struct rpc_clnt * clnt,const struct rpc_task * task)2263 static void rpc_show_task(const struct rpc_clnt *clnt,
2264 			  const struct rpc_task *task)
2265 {
2266 	const char *rpc_waitq = "none";
2267 
2268 	if (RPC_IS_QUEUED(task))
2269 		rpc_waitq = rpc_qname(task->tk_waitqueue);
2270 
2271 	printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2272 		task->tk_pid, task->tk_flags, task->tk_status,
2273 		clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2274 		clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2275 		task->tk_action, rpc_waitq);
2276 }
2277 
rpc_show_tasks(struct net * net)2278 void rpc_show_tasks(struct net *net)
2279 {
2280 	struct rpc_clnt *clnt;
2281 	struct rpc_task *task;
2282 	int header = 0;
2283 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2284 
2285 	spin_lock(&sn->rpc_client_lock);
2286 	list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2287 		spin_lock(&clnt->cl_lock);
2288 		list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2289 			if (!header) {
2290 				rpc_show_header();
2291 				header++;
2292 			}
2293 			rpc_show_task(clnt, task);
2294 		}
2295 		spin_unlock(&clnt->cl_lock);
2296 	}
2297 	spin_unlock(&sn->rpc_client_lock);
2298 }
2299 #endif
2300