xref: /linux/net/sunrpc/rpcb_clnt.c (revision 5f4123be3cdb1dbd77fa9d6d2bb96bb9689a0a19)
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),
274 			NIPQUAD_FMT".%u.%u",
275 			NIPQUAD(address_to_register->sin_addr.s_addr),
276 			port >> 8, port & 0xff);
277 	map->r_addr = buf;
278 
279 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
280 		"local rpcbind\n", (port ? "" : "un"),
281 			map->r_prog, map->r_vers,
282 			map->r_addr, map->r_netid);
283 
284 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
285 	if (port)
286 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
287 
288 	return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
289 					sizeof(rpcb_inaddr_loopback),
290 					RPCBVERS_4, msg);
291 }
292 
293 /*
294  * Fill in AF_INET6 family-specific arguments to register
295  */
296 static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
297 				struct rpc_message *msg)
298 {
299 	struct rpcbind_args *map = msg->rpc_argp;
300 	unsigned short port = ntohs(address_to_register->sin6_port);
301 	char buf[64];
302 
303 	/* Construct AF_INET6 universal address */
304 	if (ipv6_addr_any(&address_to_register->sin6_addr))
305 		snprintf(buf, sizeof(buf), "::.%u.%u",
306 				port >> 8, port & 0xff);
307 	else
308 		snprintf(buf, sizeof(buf), NIP6_FMT".%u.%u",
309 				NIP6(address_to_register->sin6_addr),
310 				port >> 8, port & 0xff);
311 	map->r_addr = buf;
312 
313 	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
314 		"local rpcbind\n", (port ? "" : "un"),
315 			map->r_prog, map->r_vers,
316 			map->r_addr, map->r_netid);
317 
318 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
319 	if (port)
320 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
321 
322 	return rpcb_register_call((struct sockaddr *)&rpcb_in6addr_loopback,
323 					sizeof(rpcb_in6addr_loopback),
324 					RPCBVERS_4, msg);
325 }
326 
327 /**
328  * rpcb_v4_register - set or unset a port registration with the local rpcbind
329  * @program: RPC program number of service to (un)register
330  * @version: RPC version number of service to (un)register
331  * @address: address family, IP address, and port to (un)register
332  * @netid: netid of transport protocol to (un)register
333  *
334  * Returns zero if the registration request was dispatched successfully
335  * and the rpcbind daemon returned success.  Otherwise, returns an errno
336  * value that reflects the nature of the error (request could not be
337  * dispatched, timed out, or rpcbind returned an error).
338  *
339  * RPC services invoke this function to advertise their contact
340  * information via the system's rpcbind daemon.  RPC services
341  * invoke this function once for each [program, version, address,
342  * netid] tuple they wish to advertise.
343  *
344  * Callers may also unregister RPC services that are no longer
345  * available by setting the port number in the passed-in address
346  * to zero.  Callers pass a netid of "" to unregister all
347  * transport netids associated with [program, version, address].
348  *
349  * This function uses rpcbind protocol version 4 to contact the
350  * local rpcbind daemon.  The local rpcbind daemon must support
351  * version 4 of the rpcbind protocol in order for these functions
352  * to register a service successfully.
353  *
354  * Supported netids include "udp" and "tcp" for UDP and TCP over
355  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
356  * respectively.
357  *
358  * The contents of @address determine the address family and the
359  * port to be registered.  The usual practice is to pass INADDR_ANY
360  * as the raw address, but specifying a non-zero address is also
361  * supported by this API if the caller wishes to advertise an RPC
362  * service on a specific network interface.
363  *
364  * Note that passing in INADDR_ANY does not create the same service
365  * registration as IN6ADDR_ANY.  The former advertises an RPC
366  * service on any IPv4 address, but not on IPv6.  The latter
367  * advertises the service on all IPv4 and IPv6 addresses.
368  */
369 int rpcb_v4_register(const u32 program, const u32 version,
370 		     const struct sockaddr *address, const char *netid)
371 {
372 	struct rpcbind_args map = {
373 		.r_prog		= program,
374 		.r_vers		= version,
375 		.r_netid	= netid,
376 		.r_owner	= RPCB_OWNER_STRING,
377 	};
378 	struct rpc_message msg = {
379 		.rpc_argp	= &map,
380 	};
381 
382 	switch (address->sa_family) {
383 	case AF_INET:
384 		return rpcb_register_netid4((struct sockaddr_in *)address,
385 					    &msg);
386 	case AF_INET6:
387 		return rpcb_register_netid6((struct sockaddr_in6 *)address,
388 					    &msg);
389 	}
390 
391 	return -EAFNOSUPPORT;
392 }
393 
394 /**
395  * rpcb_getport_sync - obtain the port for an RPC service on a given host
396  * @sin: address of remote peer
397  * @prog: RPC program number to bind
398  * @vers: RPC version number to bind
399  * @prot: transport protocol to use to make this request
400  *
401  * Return value is the requested advertised port number,
402  * or a negative errno value.
403  *
404  * Called from outside the RPC client in a synchronous task context.
405  * Uses default timeout parameters specified by underlying transport.
406  *
407  * XXX: Needs to support IPv6
408  */
409 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
410 {
411 	struct rpcbind_args map = {
412 		.r_prog		= prog,
413 		.r_vers		= vers,
414 		.r_prot		= prot,
415 		.r_port		= 0,
416 	};
417 	struct rpc_message msg = {
418 		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
419 		.rpc_argp	= &map,
420 		.rpc_resp	= &map.r_port,
421 	};
422 	struct rpc_clnt	*rpcb_clnt;
423 	int status;
424 
425 	dprintk("RPC:       %s(" NIPQUAD_FMT ", %u, %u, %d)\n",
426 		__func__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
427 
428 	rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
429 				sizeof(*sin), prot, RPCBVERS_2);
430 	if (IS_ERR(rpcb_clnt))
431 		return PTR_ERR(rpcb_clnt);
432 
433 	status = rpc_call_sync(rpcb_clnt, &msg, 0);
434 	rpc_shutdown_client(rpcb_clnt);
435 
436 	if (status >= 0) {
437 		if (map.r_port != 0)
438 			return map.r_port;
439 		status = -EACCES;
440 	}
441 	return status;
442 }
443 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
444 
445 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
446 {
447 	struct rpc_message msg = {
448 		.rpc_proc = proc,
449 		.rpc_argp = map,
450 		.rpc_resp = &map->r_port,
451 	};
452 	struct rpc_task_setup task_setup_data = {
453 		.rpc_client = rpcb_clnt,
454 		.rpc_message = &msg,
455 		.callback_ops = &rpcb_getport_ops,
456 		.callback_data = map,
457 		.flags = RPC_TASK_ASYNC,
458 	};
459 
460 	return rpc_run_task(&task_setup_data);
461 }
462 
463 /**
464  * rpcb_getport_async - obtain the port for a given RPC service on a given host
465  * @task: task that is waiting for portmapper request
466  *
467  * This one can be called for an ongoing RPC request, and can be used in
468  * an async (rpciod) context.
469  */
470 void rpcb_getport_async(struct rpc_task *task)
471 {
472 	struct rpc_clnt *clnt = task->tk_client;
473 	struct rpc_procinfo *proc;
474 	u32 bind_version;
475 	struct rpc_xprt *xprt = task->tk_xprt;
476 	struct rpc_clnt	*rpcb_clnt;
477 	static struct rpcbind_args *map;
478 	struct rpc_task	*child;
479 	struct sockaddr_storage addr;
480 	struct sockaddr *sap = (struct sockaddr *)&addr;
481 	size_t salen;
482 	int status;
483 
484 	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
485 		task->tk_pid, __func__,
486 		clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
487 
488 	/* Autobind on cloned rpc clients is discouraged */
489 	BUG_ON(clnt->cl_parent != clnt);
490 
491 	/* Put self on the wait queue to ensure we get notified if
492 	 * some other task is already attempting to bind the port */
493 	rpc_sleep_on(&xprt->binding, task, NULL);
494 
495 	if (xprt_test_and_set_binding(xprt)) {
496 		dprintk("RPC: %5u %s: waiting for another binder\n",
497 			task->tk_pid, __func__);
498 		return;
499 	}
500 
501 	/* Someone else may have bound if we slept */
502 	if (xprt_bound(xprt)) {
503 		status = 0;
504 		dprintk("RPC: %5u %s: already bound\n",
505 			task->tk_pid, __func__);
506 		goto bailout_nofree;
507 	}
508 
509 	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
510 
511 	/* Don't ever use rpcbind v2 for AF_INET6 requests */
512 	switch (sap->sa_family) {
513 	case AF_INET:
514 		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
515 		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
516 		break;
517 	case AF_INET6:
518 		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
519 		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
520 		break;
521 	default:
522 		status = -EAFNOSUPPORT;
523 		dprintk("RPC: %5u %s: bad address family\n",
524 				task->tk_pid, __func__);
525 		goto bailout_nofree;
526 	}
527 	if (proc == NULL) {
528 		xprt->bind_index = 0;
529 		status = -EPFNOSUPPORT;
530 		dprintk("RPC: %5u %s: no more getport versions available\n",
531 			task->tk_pid, __func__);
532 		goto bailout_nofree;
533 	}
534 
535 	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
536 		task->tk_pid, __func__, bind_version);
537 
538 	rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
539 				bind_version);
540 	if (IS_ERR(rpcb_clnt)) {
541 		status = PTR_ERR(rpcb_clnt);
542 		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
543 			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
544 		goto bailout_nofree;
545 	}
546 
547 	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
548 	if (!map) {
549 		status = -ENOMEM;
550 		dprintk("RPC: %5u %s: no memory available\n",
551 			task->tk_pid, __func__);
552 		goto bailout_nofree;
553 	}
554 	map->r_prog = clnt->cl_prog;
555 	map->r_vers = clnt->cl_vers;
556 	map->r_prot = xprt->prot;
557 	map->r_port = 0;
558 	map->r_xprt = xprt_get(xprt);
559 	map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
560 	map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
561 	map->r_owner = RPCB_OWNER_STRING;	/* ignored for GETADDR */
562 	map->r_status = -EIO;
563 
564 	child = rpcb_call_async(rpcb_clnt, map, proc);
565 	rpc_release_client(rpcb_clnt);
566 	if (IS_ERR(child)) {
567 		/* rpcb_map_release() has freed the arguments */
568 		dprintk("RPC: %5u %s: rpc_run_task failed\n",
569 			task->tk_pid, __func__);
570 		return;
571 	}
572 	rpc_put_task(child);
573 
574 	task->tk_xprt->stat.bind_count++;
575 	return;
576 
577 bailout_nofree:
578 	rpcb_wake_rpcbind_waiters(xprt, status);
579 	task->tk_status = status;
580 }
581 EXPORT_SYMBOL_GPL(rpcb_getport_async);
582 
583 /*
584  * Rpcbind child task calls this callback via tk_exit.
585  */
586 static void rpcb_getport_done(struct rpc_task *child, void *data)
587 {
588 	struct rpcbind_args *map = data;
589 	struct rpc_xprt *xprt = map->r_xprt;
590 	int status = child->tk_status;
591 
592 	/* Garbage reply: retry with a lesser rpcbind version */
593 	if (status == -EIO)
594 		status = -EPROTONOSUPPORT;
595 
596 	/* rpcbind server doesn't support this rpcbind protocol version */
597 	if (status == -EPROTONOSUPPORT)
598 		xprt->bind_index++;
599 
600 	if (status < 0) {
601 		/* rpcbind server not available on remote host? */
602 		xprt->ops->set_port(xprt, 0);
603 	} else if (map->r_port == 0) {
604 		/* Requested RPC service wasn't registered on remote host */
605 		xprt->ops->set_port(xprt, 0);
606 		status = -EACCES;
607 	} else {
608 		/* Succeeded */
609 		xprt->ops->set_port(xprt, map->r_port);
610 		xprt_set_bound(xprt);
611 		status = 0;
612 	}
613 
614 	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
615 			child->tk_pid, status, map->r_port);
616 
617 	map->r_status = status;
618 }
619 
620 /*
621  * XDR functions for rpcbind
622  */
623 
624 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
625 			       struct rpcbind_args *rpcb)
626 {
627 	dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
628 			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
629 	*p++ = htonl(rpcb->r_prog);
630 	*p++ = htonl(rpcb->r_vers);
631 	*p++ = htonl(rpcb->r_prot);
632 	*p++ = htonl(rpcb->r_port);
633 
634 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
635 	return 0;
636 }
637 
638 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
639 			       unsigned short *portp)
640 {
641 	*portp = (unsigned short) ntohl(*p++);
642 	dprintk("RPC:       rpcb getport result: %u\n",
643 			*portp);
644 	return 0;
645 }
646 
647 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
648 			   unsigned int *boolp)
649 {
650 	*boolp = (unsigned int) ntohl(*p++);
651 	dprintk("RPC:       rpcb set/unset call %s\n",
652 			(*boolp ? "succeeded" : "failed"));
653 	return 0;
654 }
655 
656 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
657 			       struct rpcbind_args *rpcb)
658 {
659 	dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
660 			rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
661 	*p++ = htonl(rpcb->r_prog);
662 	*p++ = htonl(rpcb->r_vers);
663 
664 	p = xdr_encode_string(p, rpcb->r_netid);
665 	p = xdr_encode_string(p, rpcb->r_addr);
666 	p = xdr_encode_string(p, rpcb->r_owner);
667 
668 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
669 
670 	return 0;
671 }
672 
673 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
674 			       unsigned short *portp)
675 {
676 	char *addr;
677 	u32 addr_len;
678 	int c, i, f, first, val;
679 
680 	*portp = 0;
681 	addr_len = ntohl(*p++);
682 
683 	/*
684 	 * Simple sanity check.  The smallest possible universal
685 	 * address is an IPv4 address string containing 11 bytes.
686 	 */
687 	if (addr_len < 11 || addr_len > RPCBIND_MAXUADDRLEN)
688 		goto out_err;
689 
690 	/*
691 	 * Start at the end and walk backwards until the first dot
692 	 * is encountered.  When the second dot is found, we have
693 	 * both parts of the port number.
694 	 */
695 	addr = (char *)p;
696 	val = 0;
697 	first = 1;
698 	f = 1;
699 	for (i = addr_len - 1; i > 0; i--) {
700 		c = addr[i];
701 		if (c >= '0' && c <= '9') {
702 			val += (c - '0') * f;
703 			f *= 10;
704 		} else if (c == '.') {
705 			if (first) {
706 				*portp = val;
707 				val = first = 0;
708 				f = 1;
709 			} else {
710 				*portp |= (val << 8);
711 				break;
712 			}
713 		}
714 	}
715 
716 	/*
717 	 * Simple sanity check.  If we never saw a dot in the reply,
718 	 * then this was probably just garbage.
719 	 */
720 	if (first)
721 		goto out_err;
722 
723 	dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
724 	return 0;
725 
726 out_err:
727 	dprintk("RPC:       rpcbind server returned malformed reply\n");
728 	return -EIO;
729 }
730 
731 #define RPCB_program_sz		(1u)
732 #define RPCB_version_sz		(1u)
733 #define RPCB_protocol_sz	(1u)
734 #define RPCB_port_sz		(1u)
735 #define RPCB_boolean_sz		(1u)
736 
737 #define RPCB_netid_sz		(1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
738 #define RPCB_addr_sz		(1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
739 #define RPCB_ownerstring_sz	(1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
740 
741 #define RPCB_mappingargs_sz	RPCB_program_sz+RPCB_version_sz+	\
742 				RPCB_protocol_sz+RPCB_port_sz
743 #define RPCB_getaddrargs_sz	RPCB_program_sz+RPCB_version_sz+	\
744 				RPCB_netid_sz+RPCB_addr_sz+		\
745 				RPCB_ownerstring_sz
746 
747 #define RPCB_setres_sz		RPCB_boolean_sz
748 #define RPCB_getportres_sz	RPCB_port_sz
749 
750 /*
751  * Note that RFC 1833 does not put any size restrictions on the
752  * address string returned by the remote rpcbind database.
753  */
754 #define RPCB_getaddrres_sz	RPCB_addr_sz
755 
756 #define PROC(proc, argtype, restype)					\
757 	[RPCBPROC_##proc] = {						\
758 		.p_proc		= RPCBPROC_##proc,			\
759 		.p_encode	= (kxdrproc_t) rpcb_encode_##argtype,	\
760 		.p_decode	= (kxdrproc_t) rpcb_decode_##restype,	\
761 		.p_arglen	= RPCB_##argtype##args_sz,		\
762 		.p_replen	= RPCB_##restype##res_sz,		\
763 		.p_statidx	= RPCBPROC_##proc,			\
764 		.p_timer	= 0,					\
765 		.p_name		= #proc,				\
766 	}
767 
768 /*
769  * Not all rpcbind procedures described in RFC 1833 are implemented
770  * since the Linux kernel RPC code requires only these.
771  */
772 static struct rpc_procinfo rpcb_procedures2[] = {
773 	PROC(SET,		mapping,	set),
774 	PROC(UNSET,		mapping,	set),
775 	PROC(GETPORT,		mapping,	getport),
776 };
777 
778 static struct rpc_procinfo rpcb_procedures3[] = {
779 	PROC(SET,		getaddr,	set),
780 	PROC(UNSET,		getaddr,	set),
781 	PROC(GETADDR,		getaddr,	getaddr),
782 };
783 
784 static struct rpc_procinfo rpcb_procedures4[] = {
785 	PROC(SET,		getaddr,	set),
786 	PROC(UNSET,		getaddr,	set),
787 	PROC(GETADDR,		getaddr,	getaddr),
788 	PROC(GETVERSADDR,	getaddr,	getaddr),
789 };
790 
791 static struct rpcb_info rpcb_next_version[] = {
792 	{
793 		.rpc_vers	= RPCBVERS_2,
794 		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
795 	},
796 	{
797 		.rpc_proc	= NULL,
798 	},
799 };
800 
801 static struct rpcb_info rpcb_next_version6[] = {
802 	{
803 		.rpc_vers	= RPCBVERS_4,
804 		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
805 	},
806 	{
807 		.rpc_vers	= RPCBVERS_3,
808 		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
809 	},
810 	{
811 		.rpc_proc	= NULL,
812 	},
813 };
814 
815 static struct rpc_version rpcb_version2 = {
816 	.number		= RPCBVERS_2,
817 	.nrprocs	= RPCB_HIGHPROC_2,
818 	.procs		= rpcb_procedures2
819 };
820 
821 static struct rpc_version rpcb_version3 = {
822 	.number		= RPCBVERS_3,
823 	.nrprocs	= RPCB_HIGHPROC_3,
824 	.procs		= rpcb_procedures3
825 };
826 
827 static struct rpc_version rpcb_version4 = {
828 	.number		= RPCBVERS_4,
829 	.nrprocs	= RPCB_HIGHPROC_4,
830 	.procs		= rpcb_procedures4
831 };
832 
833 static struct rpc_version *rpcb_version[] = {
834 	NULL,
835 	NULL,
836 	&rpcb_version2,
837 	&rpcb_version3,
838 	&rpcb_version4
839 };
840 
841 static struct rpc_stat rpcb_stats;
842 
843 static struct rpc_program rpcb_program = {
844 	.name		= "rpcbind",
845 	.number		= RPCBIND_PROGRAM,
846 	.nrvers		= ARRAY_SIZE(rpcb_version),
847 	.version	= rpcb_version,
848 	.stats		= &rpcb_stats,
849 };
850