xref: /linux/net/sunrpc/rpcb_clnt.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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 <net/ipv6.h>
24 
25 #include <linux/sunrpc/clnt.h>
26 #include <linux/sunrpc/sched.h>
27 #include <linux/sunrpc/xprtsock.h>
28 
29 #ifdef RPC_DEBUG
30 # define RPCDBG_FACILITY	RPCDBG_BIND
31 #endif
32 
33 #define RPCBIND_PROGRAM		(100000u)
34 #define RPCBIND_PORT		(111u)
35 
36 #define RPCBVERS_2		(2u)
37 #define RPCBVERS_3		(3u)
38 #define RPCBVERS_4		(4u)
39 
40 enum {
41 	RPCBPROC_NULL,
42 	RPCBPROC_SET,
43 	RPCBPROC_UNSET,
44 	RPCBPROC_GETPORT,
45 	RPCBPROC_GETADDR = 3,		/* alias for GETPORT */
46 	RPCBPROC_DUMP,
47 	RPCBPROC_CALLIT,
48 	RPCBPROC_BCAST = 5,		/* alias for CALLIT */
49 	RPCBPROC_GETTIME,
50 	RPCBPROC_UADDR2TADDR,
51 	RPCBPROC_TADDR2UADDR,
52 	RPCBPROC_GETVERSADDR,
53 	RPCBPROC_INDIRECT,
54 	RPCBPROC_GETADDRLIST,
55 	RPCBPROC_GETSTAT,
56 };
57 
58 #define RPCB_HIGHPROC_2		RPCBPROC_CALLIT
59 #define RPCB_HIGHPROC_3		RPCBPROC_TADDR2UADDR
60 #define RPCB_HIGHPROC_4		RPCBPROC_GETSTAT
61 
62 /*
63  * r_owner
64  *
65  * The "owner" is allowed to unset a service in the rpcbind database.
66  * We always use the following (arbitrary) fixed string.
67  */
68 #define RPCB_OWNER_STRING	"rpcb"
69 #define RPCB_MAXOWNERLEN	sizeof(RPCB_OWNER_STRING)
70 
71 static void			rpcb_getport_done(struct rpc_task *, void *);
72 static void			rpcb_map_release(void *data);
73 static struct rpc_program	rpcb_program;
74 
75 struct rpcbind_args {
76 	struct rpc_xprt *	r_xprt;
77 
78 	u32			r_prog;
79 	u32			r_vers;
80 	u32			r_prot;
81 	unsigned short		r_port;
82 	const char *		r_netid;
83 	const char *		r_addr;
84 	const char *		r_owner;
85 
86 	int			r_status;
87 };
88 
89 static struct rpc_procinfo rpcb_procedures2[];
90 static struct rpc_procinfo rpcb_procedures3[];
91 static struct rpc_procinfo rpcb_procedures4[];
92 
93 struct rpcb_info {
94 	u32			rpc_vers;
95 	struct rpc_procinfo *	rpc_proc;
96 };
97 
98 static struct rpcb_info rpcb_next_version[];
99 static struct rpcb_info rpcb_next_version6[];
100 
101 static const struct rpc_call_ops rpcb_getport_ops = {
102 	.rpc_call_done		= rpcb_getport_done,
103 	.rpc_release		= rpcb_map_release,
104 };
105 
106 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
107 {
108 	xprt_clear_binding(xprt);
109 	rpc_wake_up_status(&xprt->binding, status);
110 }
111 
112 static void rpcb_map_release(void *data)
113 {
114 	struct rpcbind_args *map = data;
115 
116 	rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
117 	xprt_put(map->r_xprt);
118 	kfree(map);
119 }
120 
121 static const struct sockaddr_in rpcb_inaddr_loopback = {
122 	.sin_family		= AF_INET,
123 	.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
124 	.sin_port		= htons(RPCBIND_PORT),
125 };
126 
127 static const struct sockaddr_in6 rpcb_in6addr_loopback = {
128 	.sin6_family		= AF_INET6,
129 	.sin6_addr		= IN6ADDR_LOOPBACK_INIT,
130 	.sin6_port		= htons(RPCBIND_PORT),
131 };
132 
133 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
134 					  size_t addrlen, u32 version)
135 {
136 	struct rpc_create_args args = {
137 		.protocol	= XPRT_TRANSPORT_UDP,
138 		.address	= addr,
139 		.addrsize	= addrlen,
140 		.servername	= "localhost",
141 		.program	= &rpcb_program,
142 		.version	= version,
143 		.authflavor	= RPC_AUTH_UNIX,
144 		.flags		= RPC_CLNT_CREATE_NOPING,
145 	};
146 
147 	return rpc_create(&args);
148 }
149 
150 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
151 				    size_t salen, int proto, u32 version)
152 {
153 	struct rpc_create_args args = {
154 		.protocol	= proto,
155 		.address	= srvaddr,
156 		.addrsize	= salen,
157 		.servername	= hostname,
158 		.program	= &rpcb_program,
159 		.version	= version,
160 		.authflavor	= RPC_AUTH_UNIX,
161 		.flags		= (RPC_CLNT_CREATE_NOPING |
162 					RPC_CLNT_CREATE_NONPRIVPORT),
163 	};
164 
165 	switch (srvaddr->sa_family) {
166 	case AF_INET:
167 		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
168 		break;
169 	case AF_INET6:
170 		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
171 		break;
172 	default:
173 		return NULL;
174 	}
175 
176 	return rpc_create(&args);
177 }
178 
179 static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
180 			      u32 version, struct rpc_message *msg)
181 {
182 	struct rpc_clnt *rpcb_clnt;
183 	int result, error = 0;
184 
185 	msg->rpc_resp = &result;
186 
187 	rpcb_clnt = rpcb_create_local(addr, addrlen, version);
188 	if (!IS_ERR(rpcb_clnt)) {
189 		error = rpc_call_sync(rpcb_clnt, msg, 0);
190 		rpc_shutdown_client(rpcb_clnt);
191 	} else
192 		error = PTR_ERR(rpcb_clnt);
193 
194 	if (error < 0) {
195 		printk(KERN_WARNING "RPC: failed to contact local rpcbind "
196 				"server (errno %d).\n", -error);
197 		return error;
198 	}
199 
200 	if (!result)
201 		return -EACCES;
202 	return 0;
203 }
204 
205 /**
206  * rpcb_register - set or unset a port registration with the local rpcbind svc
207  * @prog: RPC program number to bind
208  * @vers: RPC version number to bind
209  * @prot: transport protocol to register
210  * @port: port value to register
211  *
212  * Returns zero if the registration request was dispatched successfully
213  * and the rpcbind daemon returned success.  Otherwise, returns an errno
214  * value that reflects the nature of the error (request could not be
215  * dispatched, timed out, or rpcbind returned an error).
216  *
217  * RPC services invoke this function to advertise their contact
218  * information via the system's rpcbind daemon.  RPC services
219  * invoke this function once for each [program, version, transport]
220  * tuple they wish to advertise.
221  *
222  * Callers may also unregister RPC services that are no longer
223  * available by setting the passed-in port to zero.  This removes
224  * all registered transports for [program, version] from the local
225  * rpcbind database.
226  *
227  * This function uses rpcbind protocol version 2 to contact the
228  * local rpcbind daemon.
229  *
230  * Registration works over both AF_INET and AF_INET6, and services
231  * registered via this function are advertised as available for any
232  * address.  If the local rpcbind daemon is listening on AF_INET6,
233  * services registered via this function will be advertised on
234  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
235  * addresses).
236  */
237 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
238 {
239 	struct rpcbind_args map = {
240 		.r_prog		= prog,
241 		.r_vers		= vers,
242 		.r_prot		= prot,
243 		.r_port		= port,
244 	};
245 	struct rpc_message msg = {
246 		.rpc_argp	= &map,
247 	};
248 
249 	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
250 			"rpcbind\n", (port ? "" : "un"),
251 			prog, vers, prot, port);
252 
253 	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
254 	if (port)
255 		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
256 
257 	return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
258 					sizeof(rpcb_inaddr_loopback),
259 					RPCBVERS_2, &msg);
260 }
261 
262 /*
263  * Fill in AF_INET family-specific arguments to register
264  */
265 static int rpcb_register_netid4(struct sockaddr_in *address_to_register,
266 				struct rpc_message *msg)
267 {
268 	struct rpcbind_args *map = msg->rpc_argp;
269 	unsigned short port = ntohs(address_to_register->sin_port);
270 	char buf[32];
271 
272 	/* Construct AF_INET universal address */
273 	snprintf(buf, sizeof(buf), "%pI4.%u.%u",
274 		 &address_to_register->sin_addr.s_addr,
275 		 port >> 8, port & 0xff);
276 	map->r_addr = buf;
277 
278 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
279 		"local rpcbind\n", (port ? "" : "un"),
280 			map->r_prog, map->r_vers,
281 			map->r_addr, map->r_netid);
282 
283 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
284 	if (port)
285 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
286 
287 	return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
288 					sizeof(rpcb_inaddr_loopback),
289 					RPCBVERS_4, msg);
290 }
291 
292 /*
293  * Fill in AF_INET6 family-specific arguments to register
294  */
295 static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
296 				struct rpc_message *msg)
297 {
298 	struct rpcbind_args *map = msg->rpc_argp;
299 	unsigned short port = ntohs(address_to_register->sin6_port);
300 	char buf[64];
301 
302 	/* Construct AF_INET6 universal address */
303 	if (ipv6_addr_any(&address_to_register->sin6_addr))
304 		snprintf(buf, sizeof(buf), "::.%u.%u",
305 				port >> 8, port & 0xff);
306 	else
307 		snprintf(buf, sizeof(buf), "%pI6.%u.%u",
308 			 &address_to_register->sin6_addr,
309 			 port >> 8, port & 0xff);
310 	map->r_addr = buf;
311 
312 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
313 		"local rpcbind\n", (port ? "" : "un"),
314 			map->r_prog, map->r_vers,
315 			map->r_addr, map->r_netid);
316 
317 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
318 	if (port)
319 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
320 
321 	return rpcb_register_call((struct sockaddr *)&rpcb_in6addr_loopback,
322 					sizeof(rpcb_in6addr_loopback),
323 					RPCBVERS_4, msg);
324 }
325 
326 /**
327  * rpcb_v4_register - set or unset a port registration with the local rpcbind
328  * @program: RPC program number of service to (un)register
329  * @version: RPC version number of service to (un)register
330  * @address: address family, IP address, and port to (un)register
331  * @netid: netid of transport protocol to (un)register
332  *
333  * Returns zero if the registration request was dispatched successfully
334  * and the rpcbind daemon returned success.  Otherwise, returns an errno
335  * value that reflects the nature of the error (request could not be
336  * dispatched, timed out, or rpcbind returned an error).
337  *
338  * RPC services invoke this function to advertise their contact
339  * information via the system's rpcbind daemon.  RPC services
340  * invoke this function once for each [program, version, address,
341  * netid] tuple they wish to advertise.
342  *
343  * Callers may also unregister RPC services that are no longer
344  * available by setting the port number in the passed-in address
345  * to zero.  Callers pass a netid of "" to unregister all
346  * transport netids associated with [program, version, address].
347  *
348  * This function uses rpcbind protocol version 4 to contact the
349  * local rpcbind daemon.  The local rpcbind daemon must support
350  * version 4 of the rpcbind protocol in order for these functions
351  * to register a service successfully.
352  *
353  * Supported netids include "udp" and "tcp" for UDP and TCP over
354  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
355  * respectively.
356  *
357  * The contents of @address determine the address family and the
358  * port to be registered.  The usual practice is to pass INADDR_ANY
359  * as the raw address, but specifying a non-zero address is also
360  * supported by this API if the caller wishes to advertise an RPC
361  * service on a specific network interface.
362  *
363  * Note that passing in INADDR_ANY does not create the same service
364  * registration as IN6ADDR_ANY.  The former advertises an RPC
365  * service on any IPv4 address, but not on IPv6.  The latter
366  * advertises the service on all IPv4 and IPv6 addresses.
367  */
368 int rpcb_v4_register(const u32 program, const u32 version,
369 		     const struct sockaddr *address, const char *netid)
370 {
371 	struct rpcbind_args map = {
372 		.r_prog		= program,
373 		.r_vers		= version,
374 		.r_netid	= netid,
375 		.r_owner	= RPCB_OWNER_STRING,
376 	};
377 	struct rpc_message msg = {
378 		.rpc_argp	= &map,
379 	};
380 
381 	switch (address->sa_family) {
382 	case AF_INET:
383 		return rpcb_register_netid4((struct sockaddr_in *)address,
384 					    &msg);
385 	case AF_INET6:
386 		return rpcb_register_netid6((struct sockaddr_in6 *)address,
387 					    &msg);
388 	}
389 
390 	return -EAFNOSUPPORT;
391 }
392 
393 /**
394  * rpcb_getport_sync - obtain the port for an RPC service on a given host
395  * @sin: address of remote peer
396  * @prog: RPC program number to bind
397  * @vers: RPC version number to bind
398  * @prot: transport protocol to use to make this request
399  *
400  * Return value is the requested advertised port number,
401  * or a negative errno value.
402  *
403  * Called from outside the RPC client in a synchronous task context.
404  * Uses default timeout parameters specified by underlying transport.
405  *
406  * XXX: Needs to support IPv6
407  */
408 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
409 {
410 	struct rpcbind_args map = {
411 		.r_prog		= prog,
412 		.r_vers		= vers,
413 		.r_prot		= prot,
414 		.r_port		= 0,
415 	};
416 	struct rpc_message msg = {
417 		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
418 		.rpc_argp	= &map,
419 		.rpc_resp	= &map.r_port,
420 	};
421 	struct rpc_clnt	*rpcb_clnt;
422 	int status;
423 
424 	dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
425 		__func__, &sin->sin_addr.s_addr, prog, vers, prot);
426 
427 	rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
428 				sizeof(*sin), prot, RPCBVERS_2);
429 	if (IS_ERR(rpcb_clnt))
430 		return PTR_ERR(rpcb_clnt);
431 
432 	status = rpc_call_sync(rpcb_clnt, &msg, 0);
433 	rpc_shutdown_client(rpcb_clnt);
434 
435 	if (status >= 0) {
436 		if (map.r_port != 0)
437 			return map.r_port;
438 		status = -EACCES;
439 	}
440 	return status;
441 }
442 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
443 
444 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
445 {
446 	struct rpc_message msg = {
447 		.rpc_proc = proc,
448 		.rpc_argp = map,
449 		.rpc_resp = &map->r_port,
450 	};
451 	struct rpc_task_setup task_setup_data = {
452 		.rpc_client = rpcb_clnt,
453 		.rpc_message = &msg,
454 		.callback_ops = &rpcb_getport_ops,
455 		.callback_data = map,
456 		.flags = RPC_TASK_ASYNC,
457 	};
458 
459 	return rpc_run_task(&task_setup_data);
460 }
461 
462 /*
463  * In the case where rpc clients have been cloned, we want to make
464  * sure that we use the program number/version etc of the actual
465  * owner of the xprt. To do so, we walk back up the tree of parents
466  * to find whoever created the transport and/or whoever has the
467  * autobind flag set.
468  */
469 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
470 {
471 	struct rpc_clnt *parent = clnt->cl_parent;
472 
473 	while (parent != clnt) {
474 		if (parent->cl_xprt != clnt->cl_xprt)
475 			break;
476 		if (clnt->cl_autobind)
477 			break;
478 		clnt = parent;
479 		parent = parent->cl_parent;
480 	}
481 	return clnt;
482 }
483 
484 /**
485  * rpcb_getport_async - obtain the port for a given RPC service on a given host
486  * @task: task that is waiting for portmapper request
487  *
488  * This one can be called for an ongoing RPC request, and can be used in
489  * an async (rpciod) context.
490  */
491 void rpcb_getport_async(struct rpc_task *task)
492 {
493 	struct rpc_clnt *clnt;
494 	struct rpc_procinfo *proc;
495 	u32 bind_version;
496 	struct rpc_xprt *xprt;
497 	struct rpc_clnt	*rpcb_clnt;
498 	static struct rpcbind_args *map;
499 	struct rpc_task	*child;
500 	struct sockaddr_storage addr;
501 	struct sockaddr *sap = (struct sockaddr *)&addr;
502 	size_t salen;
503 	int status;
504 
505 	clnt = rpcb_find_transport_owner(task->tk_client);
506 	xprt = clnt->cl_xprt;
507 
508 	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
509 		task->tk_pid, __func__,
510 		clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
511 
512 	/* Put self on the wait queue to ensure we get notified if
513 	 * some other task is already attempting to bind the port */
514 	rpc_sleep_on(&xprt->binding, task, NULL);
515 
516 	if (xprt_test_and_set_binding(xprt)) {
517 		dprintk("RPC: %5u %s: waiting for another binder\n",
518 			task->tk_pid, __func__);
519 		return;
520 	}
521 
522 	/* Someone else may have bound if we slept */
523 	if (xprt_bound(xprt)) {
524 		status = 0;
525 		dprintk("RPC: %5u %s: already bound\n",
526 			task->tk_pid, __func__);
527 		goto bailout_nofree;
528 	}
529 
530 	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
531 
532 	/* Don't ever use rpcbind v2 for AF_INET6 requests */
533 	switch (sap->sa_family) {
534 	case AF_INET:
535 		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
536 		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
537 		break;
538 	case AF_INET6:
539 		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
540 		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
541 		break;
542 	default:
543 		status = -EAFNOSUPPORT;
544 		dprintk("RPC: %5u %s: bad address family\n",
545 				task->tk_pid, __func__);
546 		goto bailout_nofree;
547 	}
548 	if (proc == NULL) {
549 		xprt->bind_index = 0;
550 		status = -EPFNOSUPPORT;
551 		dprintk("RPC: %5u %s: no more getport versions available\n",
552 			task->tk_pid, __func__);
553 		goto bailout_nofree;
554 	}
555 
556 	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
557 		task->tk_pid, __func__, bind_version);
558 
559 	rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
560 				bind_version);
561 	if (IS_ERR(rpcb_clnt)) {
562 		status = PTR_ERR(rpcb_clnt);
563 		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
564 			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
565 		goto bailout_nofree;
566 	}
567 
568 	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
569 	if (!map) {
570 		status = -ENOMEM;
571 		dprintk("RPC: %5u %s: no memory available\n",
572 			task->tk_pid, __func__);
573 		goto bailout_release_client;
574 	}
575 	map->r_prog = clnt->cl_prog;
576 	map->r_vers = clnt->cl_vers;
577 	map->r_prot = xprt->prot;
578 	map->r_port = 0;
579 	map->r_xprt = xprt_get(xprt);
580 	map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
581 	map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
582 	map->r_owner = RPCB_OWNER_STRING;	/* ignored for GETADDR */
583 	map->r_status = -EIO;
584 
585 	child = rpcb_call_async(rpcb_clnt, map, proc);
586 	rpc_release_client(rpcb_clnt);
587 	if (IS_ERR(child)) {
588 		/* rpcb_map_release() has freed the arguments */
589 		dprintk("RPC: %5u %s: rpc_run_task failed\n",
590 			task->tk_pid, __func__);
591 		return;
592 	}
593 
594 	xprt->stat.bind_count++;
595 	rpc_put_task(child);
596 	return;
597 
598 bailout_release_client:
599 	rpc_release_client(rpcb_clnt);
600 bailout_nofree:
601 	rpcb_wake_rpcbind_waiters(xprt, status);
602 	task->tk_status = status;
603 }
604 EXPORT_SYMBOL_GPL(rpcb_getport_async);
605 
606 /*
607  * Rpcbind child task calls this callback via tk_exit.
608  */
609 static void rpcb_getport_done(struct rpc_task *child, void *data)
610 {
611 	struct rpcbind_args *map = data;
612 	struct rpc_xprt *xprt = map->r_xprt;
613 	int status = child->tk_status;
614 
615 	/* Garbage reply: retry with a lesser rpcbind version */
616 	if (status == -EIO)
617 		status = -EPROTONOSUPPORT;
618 
619 	/* rpcbind server doesn't support this rpcbind protocol version */
620 	if (status == -EPROTONOSUPPORT)
621 		xprt->bind_index++;
622 
623 	if (status < 0) {
624 		/* rpcbind server not available on remote host? */
625 		xprt->ops->set_port(xprt, 0);
626 	} else if (map->r_port == 0) {
627 		/* Requested RPC service wasn't registered on remote host */
628 		xprt->ops->set_port(xprt, 0);
629 		status = -EACCES;
630 	} else {
631 		/* Succeeded */
632 		xprt->ops->set_port(xprt, map->r_port);
633 		xprt_set_bound(xprt);
634 		status = 0;
635 	}
636 
637 	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
638 			child->tk_pid, status, map->r_port);
639 
640 	map->r_status = status;
641 }
642 
643 /*
644  * XDR functions for rpcbind
645  */
646 
647 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
648 			       struct rpcbind_args *rpcb)
649 {
650 	dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
651 			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
652 	*p++ = htonl(rpcb->r_prog);
653 	*p++ = htonl(rpcb->r_vers);
654 	*p++ = htonl(rpcb->r_prot);
655 	*p++ = htonl(rpcb->r_port);
656 
657 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
658 	return 0;
659 }
660 
661 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
662 			       unsigned short *portp)
663 {
664 	*portp = (unsigned short) ntohl(*p++);
665 	dprintk("RPC:       rpcb getport result: %u\n",
666 			*portp);
667 	return 0;
668 }
669 
670 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
671 			   unsigned int *boolp)
672 {
673 	*boolp = (unsigned int) ntohl(*p++);
674 	dprintk("RPC:       rpcb set/unset call %s\n",
675 			(*boolp ? "succeeded" : "failed"));
676 	return 0;
677 }
678 
679 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
680 			       struct rpcbind_args *rpcb)
681 {
682 	dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
683 			rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
684 	*p++ = htonl(rpcb->r_prog);
685 	*p++ = htonl(rpcb->r_vers);
686 
687 	p = xdr_encode_string(p, rpcb->r_netid);
688 	p = xdr_encode_string(p, rpcb->r_addr);
689 	p = xdr_encode_string(p, rpcb->r_owner);
690 
691 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
692 
693 	return 0;
694 }
695 
696 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
697 			       unsigned short *portp)
698 {
699 	char *addr;
700 	u32 addr_len;
701 	int c, i, f, first, val;
702 
703 	*portp = 0;
704 	addr_len = ntohl(*p++);
705 
706 	/*
707 	 * Simple sanity check.  The smallest possible universal
708 	 * address is an IPv4 address string containing 11 bytes.
709 	 */
710 	if (addr_len < 11 || addr_len > RPCBIND_MAXUADDRLEN)
711 		goto out_err;
712 
713 	/*
714 	 * Start at the end and walk backwards until the first dot
715 	 * is encountered.  When the second dot is found, we have
716 	 * both parts of the port number.
717 	 */
718 	addr = (char *)p;
719 	val = 0;
720 	first = 1;
721 	f = 1;
722 	for (i = addr_len - 1; i > 0; i--) {
723 		c = addr[i];
724 		if (c >= '0' && c <= '9') {
725 			val += (c - '0') * f;
726 			f *= 10;
727 		} else if (c == '.') {
728 			if (first) {
729 				*portp = val;
730 				val = first = 0;
731 				f = 1;
732 			} else {
733 				*portp |= (val << 8);
734 				break;
735 			}
736 		}
737 	}
738 
739 	/*
740 	 * Simple sanity check.  If we never saw a dot in the reply,
741 	 * then this was probably just garbage.
742 	 */
743 	if (first)
744 		goto out_err;
745 
746 	dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
747 	return 0;
748 
749 out_err:
750 	dprintk("RPC:       rpcbind server returned malformed reply\n");
751 	return -EIO;
752 }
753 
754 #define RPCB_program_sz		(1u)
755 #define RPCB_version_sz		(1u)
756 #define RPCB_protocol_sz	(1u)
757 #define RPCB_port_sz		(1u)
758 #define RPCB_boolean_sz		(1u)
759 
760 #define RPCB_netid_sz		(1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
761 #define RPCB_addr_sz		(1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
762 #define RPCB_ownerstring_sz	(1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
763 
764 #define RPCB_mappingargs_sz	RPCB_program_sz+RPCB_version_sz+	\
765 				RPCB_protocol_sz+RPCB_port_sz
766 #define RPCB_getaddrargs_sz	RPCB_program_sz+RPCB_version_sz+	\
767 				RPCB_netid_sz+RPCB_addr_sz+		\
768 				RPCB_ownerstring_sz
769 
770 #define RPCB_setres_sz		RPCB_boolean_sz
771 #define RPCB_getportres_sz	RPCB_port_sz
772 
773 /*
774  * Note that RFC 1833 does not put any size restrictions on the
775  * address string returned by the remote rpcbind database.
776  */
777 #define RPCB_getaddrres_sz	RPCB_addr_sz
778 
779 #define PROC(proc, argtype, restype)					\
780 	[RPCBPROC_##proc] = {						\
781 		.p_proc		= RPCBPROC_##proc,			\
782 		.p_encode	= (kxdrproc_t) rpcb_encode_##argtype,	\
783 		.p_decode	= (kxdrproc_t) rpcb_decode_##restype,	\
784 		.p_arglen	= RPCB_##argtype##args_sz,		\
785 		.p_replen	= RPCB_##restype##res_sz,		\
786 		.p_statidx	= RPCBPROC_##proc,			\
787 		.p_timer	= 0,					\
788 		.p_name		= #proc,				\
789 	}
790 
791 /*
792  * Not all rpcbind procedures described in RFC 1833 are implemented
793  * since the Linux kernel RPC code requires only these.
794  */
795 static struct rpc_procinfo rpcb_procedures2[] = {
796 	PROC(SET,		mapping,	set),
797 	PROC(UNSET,		mapping,	set),
798 	PROC(GETPORT,		mapping,	getport),
799 };
800 
801 static struct rpc_procinfo rpcb_procedures3[] = {
802 	PROC(SET,		getaddr,	set),
803 	PROC(UNSET,		getaddr,	set),
804 	PROC(GETADDR,		getaddr,	getaddr),
805 };
806 
807 static struct rpc_procinfo rpcb_procedures4[] = {
808 	PROC(SET,		getaddr,	set),
809 	PROC(UNSET,		getaddr,	set),
810 	PROC(GETADDR,		getaddr,	getaddr),
811 	PROC(GETVERSADDR,	getaddr,	getaddr),
812 };
813 
814 static struct rpcb_info rpcb_next_version[] = {
815 	{
816 		.rpc_vers	= RPCBVERS_2,
817 		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
818 	},
819 	{
820 		.rpc_proc	= NULL,
821 	},
822 };
823 
824 static struct rpcb_info rpcb_next_version6[] = {
825 	{
826 		.rpc_vers	= RPCBVERS_4,
827 		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
828 	},
829 	{
830 		.rpc_vers	= RPCBVERS_3,
831 		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
832 	},
833 	{
834 		.rpc_proc	= NULL,
835 	},
836 };
837 
838 static struct rpc_version rpcb_version2 = {
839 	.number		= RPCBVERS_2,
840 	.nrprocs	= RPCB_HIGHPROC_2,
841 	.procs		= rpcb_procedures2
842 };
843 
844 static struct rpc_version rpcb_version3 = {
845 	.number		= RPCBVERS_3,
846 	.nrprocs	= RPCB_HIGHPROC_3,
847 	.procs		= rpcb_procedures3
848 };
849 
850 static struct rpc_version rpcb_version4 = {
851 	.number		= RPCBVERS_4,
852 	.nrprocs	= RPCB_HIGHPROC_4,
853 	.procs		= rpcb_procedures4
854 };
855 
856 static struct rpc_version *rpcb_version[] = {
857 	NULL,
858 	NULL,
859 	&rpcb_version2,
860 	&rpcb_version3,
861 	&rpcb_version4
862 };
863 
864 static struct rpc_stat rpcb_stats;
865 
866 static struct rpc_program rpcb_program = {
867 	.name		= "rpcbind",
868 	.number		= RPCBIND_PROGRAM,
869 	.nrvers		= ARRAY_SIZE(rpcb_version),
870 	.version	= rpcb_version,
871 	.stats		= &rpcb_stats,
872 };
873