xref: /openbmc/linux/net/sunrpc/rpcb_clnt.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
3  * protocol
4  *
5  * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
6  * RFC 3530: "Network File System (NFS) version 4 Protocol"
7  *
8  * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
9  * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
10  *
11  * Descended from net/sunrpc/pmap_clnt.c,
12  *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
13  */
14 
15 #include <linux/module.h>
16 
17 #include <linux/types.h>
18 #include <linux/socket.h>
19 #include <linux/in.h>
20 #include <linux/in6.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/mutex.h>
24 #include <linux/slab.h>
25 #include <net/ipv6.h>
26 
27 #include <linux/sunrpc/clnt.h>
28 #include <linux/sunrpc/sched.h>
29 #include <linux/sunrpc/xprtsock.h>
30 
31 #ifdef RPC_DEBUG
32 # define RPCDBG_FACILITY	RPCDBG_BIND
33 #endif
34 
35 #define RPCBIND_PROGRAM		(100000u)
36 #define RPCBIND_PORT		(111u)
37 
38 #define RPCBVERS_2		(2u)
39 #define RPCBVERS_3		(3u)
40 #define RPCBVERS_4		(4u)
41 
42 enum {
43 	RPCBPROC_NULL,
44 	RPCBPROC_SET,
45 	RPCBPROC_UNSET,
46 	RPCBPROC_GETPORT,
47 	RPCBPROC_GETADDR = 3,		/* alias for GETPORT */
48 	RPCBPROC_DUMP,
49 	RPCBPROC_CALLIT,
50 	RPCBPROC_BCAST = 5,		/* alias for CALLIT */
51 	RPCBPROC_GETTIME,
52 	RPCBPROC_UADDR2TADDR,
53 	RPCBPROC_TADDR2UADDR,
54 	RPCBPROC_GETVERSADDR,
55 	RPCBPROC_INDIRECT,
56 	RPCBPROC_GETADDRLIST,
57 	RPCBPROC_GETSTAT,
58 };
59 
60 #define RPCB_HIGHPROC_2		RPCBPROC_CALLIT
61 #define RPCB_HIGHPROC_3		RPCBPROC_TADDR2UADDR
62 #define RPCB_HIGHPROC_4		RPCBPROC_GETSTAT
63 
64 /*
65  * r_owner
66  *
67  * The "owner" is allowed to unset a service in the rpcbind database.
68  *
69  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
70  * UID which it maps to a local user name via a password lookup.
71  * In all other cases it is ignored.
72  *
73  * For SET/UNSET requests, user space provides a value, even for
74  * network requests, and GETADDR uses an empty string.  We follow
75  * those precedents here.
76  */
77 #define RPCB_OWNER_STRING	"0"
78 #define RPCB_MAXOWNERLEN	sizeof(RPCB_OWNER_STRING)
79 
80 /*
81  * XDR data type sizes
82  */
83 #define RPCB_program_sz		(1)
84 #define RPCB_version_sz		(1)
85 #define RPCB_protocol_sz	(1)
86 #define RPCB_port_sz		(1)
87 #define RPCB_boolean_sz		(1)
88 
89 #define RPCB_netid_sz		(1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
90 #define RPCB_addr_sz		(1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
91 #define RPCB_ownerstring_sz	(1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
92 
93 /*
94  * XDR argument and result sizes
95  */
96 #define RPCB_mappingargs_sz	(RPCB_program_sz + RPCB_version_sz + \
97 				RPCB_protocol_sz + RPCB_port_sz)
98 #define RPCB_getaddrargs_sz	(RPCB_program_sz + RPCB_version_sz + \
99 				RPCB_netid_sz + RPCB_addr_sz + \
100 				RPCB_ownerstring_sz)
101 
102 #define RPCB_getportres_sz	RPCB_port_sz
103 #define RPCB_setres_sz		RPCB_boolean_sz
104 
105 /*
106  * Note that RFC 1833 does not put any size restrictions on the
107  * address string returned by the remote rpcbind database.
108  */
109 #define RPCB_getaddrres_sz	RPCB_addr_sz
110 
111 static void			rpcb_getport_done(struct rpc_task *, void *);
112 static void			rpcb_map_release(void *data);
113 static struct rpc_program	rpcb_program;
114 
115 static struct rpc_clnt *	rpcb_local_clnt;
116 static struct rpc_clnt *	rpcb_local_clnt4;
117 
118 struct rpcbind_args {
119 	struct rpc_xprt *	r_xprt;
120 
121 	u32			r_prog;
122 	u32			r_vers;
123 	u32			r_prot;
124 	unsigned short		r_port;
125 	const char *		r_netid;
126 	const char *		r_addr;
127 	const char *		r_owner;
128 
129 	int			r_status;
130 };
131 
132 static struct rpc_procinfo rpcb_procedures2[];
133 static struct rpc_procinfo rpcb_procedures3[];
134 static struct rpc_procinfo rpcb_procedures4[];
135 
136 struct rpcb_info {
137 	u32			rpc_vers;
138 	struct rpc_procinfo *	rpc_proc;
139 };
140 
141 static struct rpcb_info rpcb_next_version[];
142 static struct rpcb_info rpcb_next_version6[];
143 
144 static const struct rpc_call_ops rpcb_getport_ops = {
145 	.rpc_call_done		= rpcb_getport_done,
146 	.rpc_release		= rpcb_map_release,
147 };
148 
149 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
150 {
151 	xprt_clear_binding(xprt);
152 	rpc_wake_up_status(&xprt->binding, status);
153 }
154 
155 static void rpcb_map_release(void *data)
156 {
157 	struct rpcbind_args *map = data;
158 
159 	rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
160 	xprt_put(map->r_xprt);
161 	kfree(map->r_addr);
162 	kfree(map);
163 }
164 
165 static const struct sockaddr_in rpcb_inaddr_loopback = {
166 	.sin_family		= AF_INET,
167 	.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
168 	.sin_port		= htons(RPCBIND_PORT),
169 };
170 
171 static DEFINE_MUTEX(rpcb_create_local_mutex);
172 
173 /*
174  * Returns zero on success, otherwise a negative errno value
175  * is returned.
176  */
177 static int rpcb_create_local(void)
178 {
179 	struct rpc_create_args args = {
180 		.net		= &init_net,
181 		.protocol	= XPRT_TRANSPORT_TCP,
182 		.address	= (struct sockaddr *)&rpcb_inaddr_loopback,
183 		.addrsize	= sizeof(rpcb_inaddr_loopback),
184 		.servername	= "localhost",
185 		.program	= &rpcb_program,
186 		.version	= RPCBVERS_2,
187 		.authflavor	= RPC_AUTH_UNIX,
188 		.flags		= RPC_CLNT_CREATE_NOPING,
189 	};
190 	struct rpc_clnt *clnt, *clnt4;
191 	int result = 0;
192 
193 	if (rpcb_local_clnt)
194 		return result;
195 
196 	mutex_lock(&rpcb_create_local_mutex);
197 	if (rpcb_local_clnt)
198 		goto out;
199 
200 	clnt = rpc_create(&args);
201 	if (IS_ERR(clnt)) {
202 		dprintk("RPC:       failed to create local rpcbind "
203 				"client (errno %ld).\n", PTR_ERR(clnt));
204 		result = -PTR_ERR(clnt);
205 		goto out;
206 	}
207 
208 	/*
209 	 * This results in an RPC ping.  On systems running portmapper,
210 	 * the v4 ping will fail.  Proceed anyway, but disallow rpcb
211 	 * v4 upcalls.
212 	 */
213 	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
214 	if (IS_ERR(clnt4)) {
215 		dprintk("RPC:       failed to bind second program to "
216 				"rpcbind v4 client (errno %ld).\n",
217 				PTR_ERR(clnt4));
218 		clnt4 = NULL;
219 	}
220 
221 	rpcb_local_clnt = clnt;
222 	rpcb_local_clnt4 = clnt4;
223 
224 out:
225 	mutex_unlock(&rpcb_create_local_mutex);
226 	return result;
227 }
228 
229 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
230 				    size_t salen, int proto, u32 version)
231 {
232 	struct rpc_create_args args = {
233 		.net		= &init_net,
234 		.protocol	= proto,
235 		.address	= srvaddr,
236 		.addrsize	= salen,
237 		.servername	= hostname,
238 		.program	= &rpcb_program,
239 		.version	= version,
240 		.authflavor	= RPC_AUTH_UNIX,
241 		.flags		= (RPC_CLNT_CREATE_NOPING |
242 					RPC_CLNT_CREATE_NONPRIVPORT),
243 	};
244 
245 	switch (srvaddr->sa_family) {
246 	case AF_INET:
247 		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
248 		break;
249 	case AF_INET6:
250 		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
251 		break;
252 	default:
253 		return ERR_PTR(-EAFNOSUPPORT);
254 	}
255 
256 	return rpc_create(&args);
257 }
258 
259 static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
260 {
261 	int result, error = 0;
262 
263 	msg->rpc_resp = &result;
264 
265 	error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
266 	if (error < 0) {
267 		dprintk("RPC:       failed to contact local rpcbind "
268 				"server (errno %d).\n", -error);
269 		return error;
270 	}
271 
272 	if (!result)
273 		return -EACCES;
274 	return 0;
275 }
276 
277 /**
278  * rpcb_register - set or unset a port registration with the local rpcbind svc
279  * @prog: RPC program number to bind
280  * @vers: RPC version number to bind
281  * @prot: transport protocol to register
282  * @port: port value to register
283  *
284  * Returns zero if the registration request was dispatched successfully
285  * and the rpcbind daemon returned success.  Otherwise, returns an errno
286  * value that reflects the nature of the error (request could not be
287  * dispatched, timed out, or rpcbind returned an error).
288  *
289  * RPC services invoke this function to advertise their contact
290  * information via the system's rpcbind daemon.  RPC services
291  * invoke this function once for each [program, version, transport]
292  * tuple they wish to advertise.
293  *
294  * Callers may also unregister RPC services that are no longer
295  * available by setting the passed-in port to zero.  This removes
296  * all registered transports for [program, version] from the local
297  * rpcbind database.
298  *
299  * This function uses rpcbind protocol version 2 to contact the
300  * local rpcbind daemon.
301  *
302  * Registration works over both AF_INET and AF_INET6, and services
303  * registered via this function are advertised as available for any
304  * address.  If the local rpcbind daemon is listening on AF_INET6,
305  * services registered via this function will be advertised on
306  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
307  * addresses).
308  */
309 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
310 {
311 	struct rpcbind_args map = {
312 		.r_prog		= prog,
313 		.r_vers		= vers,
314 		.r_prot		= prot,
315 		.r_port		= port,
316 	};
317 	struct rpc_message msg = {
318 		.rpc_argp	= &map,
319 	};
320 	int error;
321 
322 	error = rpcb_create_local();
323 	if (error)
324 		return error;
325 
326 	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
327 			"rpcbind\n", (port ? "" : "un"),
328 			prog, vers, prot, port);
329 
330 	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
331 	if (port)
332 		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
333 
334 	return rpcb_register_call(rpcb_local_clnt, &msg);
335 }
336 
337 /*
338  * Fill in AF_INET family-specific arguments to register
339  */
340 static int rpcb_register_inet4(const struct sockaddr *sap,
341 			       struct rpc_message *msg)
342 {
343 	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
344 	struct rpcbind_args *map = msg->rpc_argp;
345 	unsigned short port = ntohs(sin->sin_port);
346 	int result;
347 
348 	map->r_addr = rpc_sockaddr2uaddr(sap);
349 
350 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
351 		"local rpcbind\n", (port ? "" : "un"),
352 			map->r_prog, map->r_vers,
353 			map->r_addr, map->r_netid);
354 
355 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
356 	if (port)
357 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
358 
359 	result = rpcb_register_call(rpcb_local_clnt4, msg);
360 	kfree(map->r_addr);
361 	return result;
362 }
363 
364 /*
365  * Fill in AF_INET6 family-specific arguments to register
366  */
367 static int rpcb_register_inet6(const struct sockaddr *sap,
368 			       struct rpc_message *msg)
369 {
370 	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
371 	struct rpcbind_args *map = msg->rpc_argp;
372 	unsigned short port = ntohs(sin6->sin6_port);
373 	int result;
374 
375 	map->r_addr = rpc_sockaddr2uaddr(sap);
376 
377 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
378 		"local rpcbind\n", (port ? "" : "un"),
379 			map->r_prog, map->r_vers,
380 			map->r_addr, map->r_netid);
381 
382 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
383 	if (port)
384 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
385 
386 	result = rpcb_register_call(rpcb_local_clnt4, msg);
387 	kfree(map->r_addr);
388 	return result;
389 }
390 
391 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
392 {
393 	struct rpcbind_args *map = msg->rpc_argp;
394 
395 	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
396 		"local rpcbind\n",
397 			map->r_prog, map->r_vers, map->r_netid);
398 
399 	map->r_addr = "";
400 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
401 
402 	return rpcb_register_call(rpcb_local_clnt4, msg);
403 }
404 
405 /**
406  * rpcb_v4_register - set or unset a port registration with the local rpcbind
407  * @program: RPC program number of service to (un)register
408  * @version: RPC version number of service to (un)register
409  * @address: address family, IP address, and port to (un)register
410  * @netid: netid of transport protocol to (un)register
411  *
412  * Returns zero if the registration request was dispatched successfully
413  * and the rpcbind daemon returned success.  Otherwise, returns an errno
414  * value that reflects the nature of the error (request could not be
415  * dispatched, timed out, or rpcbind returned an error).
416  *
417  * RPC services invoke this function to advertise their contact
418  * information via the system's rpcbind daemon.  RPC services
419  * invoke this function once for each [program, version, address,
420  * netid] tuple they wish to advertise.
421  *
422  * Callers may also unregister RPC services that are registered at a
423  * specific address by setting the port number in @address to zero.
424  * They may unregister all registered protocol families at once for
425  * a service by passing a NULL @address argument.  If @netid is ""
426  * then all netids for [program, version, address] are unregistered.
427  *
428  * This function uses rpcbind protocol version 4 to contact the
429  * local rpcbind daemon.  The local rpcbind daemon must support
430  * version 4 of the rpcbind protocol in order for these functions
431  * to register a service successfully.
432  *
433  * Supported netids include "udp" and "tcp" for UDP and TCP over
434  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
435  * respectively.
436  *
437  * The contents of @address determine the address family and the
438  * port to be registered.  The usual practice is to pass INADDR_ANY
439  * as the raw address, but specifying a non-zero address is also
440  * supported by this API if the caller wishes to advertise an RPC
441  * service on a specific network interface.
442  *
443  * Note that passing in INADDR_ANY does not create the same service
444  * registration as IN6ADDR_ANY.  The former advertises an RPC
445  * service on any IPv4 address, but not on IPv6.  The latter
446  * advertises the service on all IPv4 and IPv6 addresses.
447  */
448 int rpcb_v4_register(const u32 program, const u32 version,
449 		     const struct sockaddr *address, const char *netid)
450 {
451 	struct rpcbind_args map = {
452 		.r_prog		= program,
453 		.r_vers		= version,
454 		.r_netid	= netid,
455 		.r_owner	= RPCB_OWNER_STRING,
456 	};
457 	struct rpc_message msg = {
458 		.rpc_argp	= &map,
459 	};
460 	int error;
461 
462 	error = rpcb_create_local();
463 	if (error)
464 		return error;
465 	if (rpcb_local_clnt4 == NULL)
466 		return -EPROTONOSUPPORT;
467 
468 	if (address == NULL)
469 		return rpcb_unregister_all_protofamilies(&msg);
470 
471 	switch (address->sa_family) {
472 	case AF_INET:
473 		return rpcb_register_inet4(address, &msg);
474 	case AF_INET6:
475 		return rpcb_register_inet6(address, &msg);
476 	}
477 
478 	return -EAFNOSUPPORT;
479 }
480 
481 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
482 {
483 	struct rpc_message msg = {
484 		.rpc_proc = proc,
485 		.rpc_argp = map,
486 		.rpc_resp = map,
487 	};
488 	struct rpc_task_setup task_setup_data = {
489 		.rpc_client = rpcb_clnt,
490 		.rpc_message = &msg,
491 		.callback_ops = &rpcb_getport_ops,
492 		.callback_data = map,
493 		.flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
494 	};
495 
496 	return rpc_run_task(&task_setup_data);
497 }
498 
499 /*
500  * In the case where rpc clients have been cloned, we want to make
501  * sure that we use the program number/version etc of the actual
502  * owner of the xprt. To do so, we walk back up the tree of parents
503  * to find whoever created the transport and/or whoever has the
504  * autobind flag set.
505  */
506 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
507 {
508 	struct rpc_clnt *parent = clnt->cl_parent;
509 
510 	while (parent != clnt) {
511 		if (parent->cl_xprt != clnt->cl_xprt)
512 			break;
513 		if (clnt->cl_autobind)
514 			break;
515 		clnt = parent;
516 		parent = parent->cl_parent;
517 	}
518 	return clnt;
519 }
520 
521 /**
522  * rpcb_getport_async - obtain the port for a given RPC service on a given host
523  * @task: task that is waiting for portmapper request
524  *
525  * This one can be called for an ongoing RPC request, and can be used in
526  * an async (rpciod) context.
527  */
528 void rpcb_getport_async(struct rpc_task *task)
529 {
530 	struct rpc_clnt *clnt;
531 	struct rpc_procinfo *proc;
532 	u32 bind_version;
533 	struct rpc_xprt *xprt;
534 	struct rpc_clnt	*rpcb_clnt;
535 	static struct rpcbind_args *map;
536 	struct rpc_task	*child;
537 	struct sockaddr_storage addr;
538 	struct sockaddr *sap = (struct sockaddr *)&addr;
539 	size_t salen;
540 	int status;
541 
542 	clnt = rpcb_find_transport_owner(task->tk_client);
543 	xprt = clnt->cl_xprt;
544 
545 	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
546 		task->tk_pid, __func__,
547 		clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
548 
549 	/* Put self on the wait queue to ensure we get notified if
550 	 * some other task is already attempting to bind the port */
551 	rpc_sleep_on(&xprt->binding, task, NULL);
552 
553 	if (xprt_test_and_set_binding(xprt)) {
554 		dprintk("RPC: %5u %s: waiting for another binder\n",
555 			task->tk_pid, __func__);
556 		return;
557 	}
558 
559 	/* Someone else may have bound if we slept */
560 	if (xprt_bound(xprt)) {
561 		status = 0;
562 		dprintk("RPC: %5u %s: already bound\n",
563 			task->tk_pid, __func__);
564 		goto bailout_nofree;
565 	}
566 
567 	/* Parent transport's destination address */
568 	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
569 
570 	/* Don't ever use rpcbind v2 for AF_INET6 requests */
571 	switch (sap->sa_family) {
572 	case AF_INET:
573 		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
574 		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
575 		break;
576 	case AF_INET6:
577 		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
578 		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
579 		break;
580 	default:
581 		status = -EAFNOSUPPORT;
582 		dprintk("RPC: %5u %s: bad address family\n",
583 				task->tk_pid, __func__);
584 		goto bailout_nofree;
585 	}
586 	if (proc == NULL) {
587 		xprt->bind_index = 0;
588 		status = -EPFNOSUPPORT;
589 		dprintk("RPC: %5u %s: no more getport versions available\n",
590 			task->tk_pid, __func__);
591 		goto bailout_nofree;
592 	}
593 
594 	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
595 		task->tk_pid, __func__, bind_version);
596 
597 	rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
598 				bind_version);
599 	if (IS_ERR(rpcb_clnt)) {
600 		status = PTR_ERR(rpcb_clnt);
601 		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
602 			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
603 		goto bailout_nofree;
604 	}
605 
606 	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
607 	if (!map) {
608 		status = -ENOMEM;
609 		dprintk("RPC: %5u %s: no memory available\n",
610 			task->tk_pid, __func__);
611 		goto bailout_release_client;
612 	}
613 	map->r_prog = clnt->cl_prog;
614 	map->r_vers = clnt->cl_vers;
615 	map->r_prot = xprt->prot;
616 	map->r_port = 0;
617 	map->r_xprt = xprt_get(xprt);
618 	map->r_status = -EIO;
619 
620 	switch (bind_version) {
621 	case RPCBVERS_4:
622 	case RPCBVERS_3:
623 		map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
624 		map->r_addr = rpc_sockaddr2uaddr(sap);
625 		map->r_owner = "";
626 		break;
627 	case RPCBVERS_2:
628 		map->r_addr = NULL;
629 		break;
630 	default:
631 		BUG();
632 	}
633 
634 	child = rpcb_call_async(rpcb_clnt, map, proc);
635 	rpc_release_client(rpcb_clnt);
636 	if (IS_ERR(child)) {
637 		/* rpcb_map_release() has freed the arguments */
638 		dprintk("RPC: %5u %s: rpc_run_task failed\n",
639 			task->tk_pid, __func__);
640 		return;
641 	}
642 
643 	xprt->stat.bind_count++;
644 	rpc_put_task(child);
645 	return;
646 
647 bailout_release_client:
648 	rpc_release_client(rpcb_clnt);
649 bailout_nofree:
650 	rpcb_wake_rpcbind_waiters(xprt, status);
651 	task->tk_status = status;
652 }
653 EXPORT_SYMBOL_GPL(rpcb_getport_async);
654 
655 /*
656  * Rpcbind child task calls this callback via tk_exit.
657  */
658 static void rpcb_getport_done(struct rpc_task *child, void *data)
659 {
660 	struct rpcbind_args *map = data;
661 	struct rpc_xprt *xprt = map->r_xprt;
662 	int status = child->tk_status;
663 
664 	/* Garbage reply: retry with a lesser rpcbind version */
665 	if (status == -EIO)
666 		status = -EPROTONOSUPPORT;
667 
668 	/* rpcbind server doesn't support this rpcbind protocol version */
669 	if (status == -EPROTONOSUPPORT)
670 		xprt->bind_index++;
671 
672 	if (status < 0) {
673 		/* rpcbind server not available on remote host? */
674 		xprt->ops->set_port(xprt, 0);
675 	} else if (map->r_port == 0) {
676 		/* Requested RPC service wasn't registered on remote host */
677 		xprt->ops->set_port(xprt, 0);
678 		status = -EACCES;
679 	} else {
680 		/* Succeeded */
681 		xprt->ops->set_port(xprt, map->r_port);
682 		xprt_set_bound(xprt);
683 		status = 0;
684 	}
685 
686 	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
687 			child->tk_pid, status, map->r_port);
688 
689 	map->r_status = status;
690 }
691 
692 /*
693  * XDR functions for rpcbind
694  */
695 
696 static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
697 			    const struct rpcbind_args *rpcb)
698 {
699 	struct rpc_task *task = req->rq_task;
700 	struct xdr_stream xdr;
701 
702 	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
703 			task->tk_pid, task->tk_msg.rpc_proc->p_name,
704 			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
705 
706 	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
707 
708 	p = xdr_reserve_space(&xdr, sizeof(__be32) * RPCB_mappingargs_sz);
709 	if (unlikely(p == NULL))
710 		return -EIO;
711 
712 	*p++ = htonl(rpcb->r_prog);
713 	*p++ = htonl(rpcb->r_vers);
714 	*p++ = htonl(rpcb->r_prot);
715 	*p   = htonl(rpcb->r_port);
716 
717 	return 0;
718 }
719 
720 static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
721 			    struct rpcbind_args *rpcb)
722 {
723 	struct rpc_task *task = req->rq_task;
724 	struct xdr_stream xdr;
725 	unsigned long port;
726 
727 	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
728 
729 	rpcb->r_port = 0;
730 
731 	p = xdr_inline_decode(&xdr, sizeof(__be32));
732 	if (unlikely(p == NULL))
733 		return -EIO;
734 
735 	port = ntohl(*p);
736 	dprintk("RPC: %5u PMAP_%s result: %lu\n", task->tk_pid,
737 			task->tk_msg.rpc_proc->p_name, port);
738 	if (unlikely(port > USHRT_MAX))
739 		return -EIO;
740 
741 	rpcb->r_port = port;
742 	return 0;
743 }
744 
745 static int rpcb_dec_set(struct rpc_rqst *req, __be32 *p,
746 			unsigned int *boolp)
747 {
748 	struct rpc_task *task = req->rq_task;
749 	struct xdr_stream xdr;
750 
751 	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
752 
753 	p = xdr_inline_decode(&xdr, sizeof(__be32));
754 	if (unlikely(p == NULL))
755 		return -EIO;
756 
757 	*boolp = 0;
758 	if (*p)
759 		*boolp = 1;
760 
761 	dprintk("RPC: %5u RPCB_%s call %s\n",
762 			task->tk_pid, task->tk_msg.rpc_proc->p_name,
763 			(*boolp ? "succeeded" : "failed"));
764 	return 0;
765 }
766 
767 static int encode_rpcb_string(struct xdr_stream *xdr, const char *string,
768 				const u32 maxstrlen)
769 {
770 	u32 len;
771 	__be32 *p;
772 
773 	if (unlikely(string == NULL))
774 		return -EIO;
775 	len = strlen(string);
776 	if (unlikely(len > maxstrlen))
777 		return -EIO;
778 
779 	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
780 	if (unlikely(p == NULL))
781 		return -EIO;
782 	xdr_encode_opaque(p, string, len);
783 
784 	return 0;
785 }
786 
787 static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
788 			    const struct rpcbind_args *rpcb)
789 {
790 	struct rpc_task *task = req->rq_task;
791 	struct xdr_stream xdr;
792 
793 	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
794 			task->tk_pid, task->tk_msg.rpc_proc->p_name,
795 			rpcb->r_prog, rpcb->r_vers,
796 			rpcb->r_netid, rpcb->r_addr);
797 
798 	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
799 
800 	p = xdr_reserve_space(&xdr,
801 			sizeof(__be32) * (RPCB_program_sz + RPCB_version_sz));
802 	if (unlikely(p == NULL))
803 		return -EIO;
804 	*p++ = htonl(rpcb->r_prog);
805 	*p = htonl(rpcb->r_vers);
806 
807 	if (encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN))
808 		return -EIO;
809 	if (encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN))
810 		return -EIO;
811 	if (encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN))
812 		return -EIO;
813 
814 	return 0;
815 }
816 
817 static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
818 			    struct rpcbind_args *rpcb)
819 {
820 	struct sockaddr_storage address;
821 	struct sockaddr *sap = (struct sockaddr *)&address;
822 	struct rpc_task *task = req->rq_task;
823 	struct xdr_stream xdr;
824 	u32 len;
825 
826 	rpcb->r_port = 0;
827 
828 	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
829 
830 	p = xdr_inline_decode(&xdr, sizeof(__be32));
831 	if (unlikely(p == NULL))
832 		goto out_fail;
833 	len = ntohl(*p);
834 
835 	/*
836 	 * If the returned universal address is a null string,
837 	 * the requested RPC service was not registered.
838 	 */
839 	if (len == 0) {
840 		dprintk("RPC: %5u RPCB reply: program not registered\n",
841 				task->tk_pid);
842 		return 0;
843 	}
844 
845 	if (unlikely(len > RPCBIND_MAXUADDRLEN))
846 		goto out_fail;
847 
848 	p = xdr_inline_decode(&xdr, len);
849 	if (unlikely(p == NULL))
850 		goto out_fail;
851 	dprintk("RPC: %5u RPCB_%s reply: %s\n", task->tk_pid,
852 			task->tk_msg.rpc_proc->p_name, (char *)p);
853 
854 	if (rpc_uaddr2sockaddr((char *)p, len, sap, sizeof(address)) == 0)
855 		goto out_fail;
856 	rpcb->r_port = rpc_get_port(sap);
857 
858 	return 0;
859 
860 out_fail:
861 	dprintk("RPC: %5u malformed RPCB_%s reply\n",
862 			task->tk_pid, task->tk_msg.rpc_proc->p_name);
863 	return -EIO;
864 }
865 
866 /*
867  * Not all rpcbind procedures described in RFC 1833 are implemented
868  * since the Linux kernel RPC code requires only these.
869  */
870 
871 static struct rpc_procinfo rpcb_procedures2[] = {
872 	[RPCBPROC_SET] = {
873 		.p_proc		= RPCBPROC_SET,
874 		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
875 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
876 		.p_arglen	= RPCB_mappingargs_sz,
877 		.p_replen	= RPCB_setres_sz,
878 		.p_statidx	= RPCBPROC_SET,
879 		.p_timer	= 0,
880 		.p_name		= "SET",
881 	},
882 	[RPCBPROC_UNSET] = {
883 		.p_proc		= RPCBPROC_UNSET,
884 		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
885 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
886 		.p_arglen	= RPCB_mappingargs_sz,
887 		.p_replen	= RPCB_setres_sz,
888 		.p_statidx	= RPCBPROC_UNSET,
889 		.p_timer	= 0,
890 		.p_name		= "UNSET",
891 	},
892 	[RPCBPROC_GETPORT] = {
893 		.p_proc		= RPCBPROC_GETPORT,
894 		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
895 		.p_decode	= (kxdrproc_t)rpcb_dec_getport,
896 		.p_arglen	= RPCB_mappingargs_sz,
897 		.p_replen	= RPCB_getportres_sz,
898 		.p_statidx	= RPCBPROC_GETPORT,
899 		.p_timer	= 0,
900 		.p_name		= "GETPORT",
901 	},
902 };
903 
904 static struct rpc_procinfo rpcb_procedures3[] = {
905 	[RPCBPROC_SET] = {
906 		.p_proc		= RPCBPROC_SET,
907 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
908 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
909 		.p_arglen	= RPCB_getaddrargs_sz,
910 		.p_replen	= RPCB_setres_sz,
911 		.p_statidx	= RPCBPROC_SET,
912 		.p_timer	= 0,
913 		.p_name		= "SET",
914 	},
915 	[RPCBPROC_UNSET] = {
916 		.p_proc		= RPCBPROC_UNSET,
917 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
918 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
919 		.p_arglen	= RPCB_getaddrargs_sz,
920 		.p_replen	= RPCB_setres_sz,
921 		.p_statidx	= RPCBPROC_UNSET,
922 		.p_timer	= 0,
923 		.p_name		= "UNSET",
924 	},
925 	[RPCBPROC_GETADDR] = {
926 		.p_proc		= RPCBPROC_GETADDR,
927 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
928 		.p_decode	= (kxdrproc_t)rpcb_dec_getaddr,
929 		.p_arglen	= RPCB_getaddrargs_sz,
930 		.p_replen	= RPCB_getaddrres_sz,
931 		.p_statidx	= RPCBPROC_GETADDR,
932 		.p_timer	= 0,
933 		.p_name		= "GETADDR",
934 	},
935 };
936 
937 static struct rpc_procinfo rpcb_procedures4[] = {
938 	[RPCBPROC_SET] = {
939 		.p_proc		= RPCBPROC_SET,
940 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
941 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
942 		.p_arglen	= RPCB_getaddrargs_sz,
943 		.p_replen	= RPCB_setres_sz,
944 		.p_statidx	= RPCBPROC_SET,
945 		.p_timer	= 0,
946 		.p_name		= "SET",
947 	},
948 	[RPCBPROC_UNSET] = {
949 		.p_proc		= RPCBPROC_UNSET,
950 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
951 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
952 		.p_arglen	= RPCB_getaddrargs_sz,
953 		.p_replen	= RPCB_setres_sz,
954 		.p_statidx	= RPCBPROC_UNSET,
955 		.p_timer	= 0,
956 		.p_name		= "UNSET",
957 	},
958 	[RPCBPROC_GETADDR] = {
959 		.p_proc		= RPCBPROC_GETADDR,
960 		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
961 		.p_decode	= (kxdrproc_t)rpcb_dec_getaddr,
962 		.p_arglen	= RPCB_getaddrargs_sz,
963 		.p_replen	= RPCB_getaddrres_sz,
964 		.p_statidx	= RPCBPROC_GETADDR,
965 		.p_timer	= 0,
966 		.p_name		= "GETADDR",
967 	},
968 };
969 
970 static struct rpcb_info rpcb_next_version[] = {
971 	{
972 		.rpc_vers	= RPCBVERS_2,
973 		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
974 	},
975 	{
976 		.rpc_proc	= NULL,
977 	},
978 };
979 
980 static struct rpcb_info rpcb_next_version6[] = {
981 	{
982 		.rpc_vers	= RPCBVERS_4,
983 		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
984 	},
985 	{
986 		.rpc_vers	= RPCBVERS_3,
987 		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
988 	},
989 	{
990 		.rpc_proc	= NULL,
991 	},
992 };
993 
994 static struct rpc_version rpcb_version2 = {
995 	.number		= RPCBVERS_2,
996 	.nrprocs	= RPCB_HIGHPROC_2,
997 	.procs		= rpcb_procedures2
998 };
999 
1000 static struct rpc_version rpcb_version3 = {
1001 	.number		= RPCBVERS_3,
1002 	.nrprocs	= RPCB_HIGHPROC_3,
1003 	.procs		= rpcb_procedures3
1004 };
1005 
1006 static struct rpc_version rpcb_version4 = {
1007 	.number		= RPCBVERS_4,
1008 	.nrprocs	= RPCB_HIGHPROC_4,
1009 	.procs		= rpcb_procedures4
1010 };
1011 
1012 static struct rpc_version *rpcb_version[] = {
1013 	NULL,
1014 	NULL,
1015 	&rpcb_version2,
1016 	&rpcb_version3,
1017 	&rpcb_version4
1018 };
1019 
1020 static struct rpc_stat rpcb_stats;
1021 
1022 static struct rpc_program rpcb_program = {
1023 	.name		= "rpcbind",
1024 	.number		= RPCBIND_PROGRAM,
1025 	.nrvers		= ARRAY_SIZE(rpcb_version),
1026 	.version	= rpcb_version,
1027 	.stats		= &rpcb_stats,
1028 };
1029 
1030 /**
1031  * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
1032  *
1033  */
1034 void cleanup_rpcb_clnt(void)
1035 {
1036 	if (rpcb_local_clnt4)
1037 		rpc_shutdown_client(rpcb_local_clnt4);
1038 	if (rpcb_local_clnt)
1039 		rpc_shutdown_client(rpcb_local_clnt);
1040 }
1041