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/un.h>
20 #include <linux/in.h>
21 #include <linux/in6.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <linux/nsproxy.h>
27 #include <net/ipv6.h>
28
29 #include <linux/sunrpc/clnt.h>
30 #include <linux/sunrpc/sched.h>
31 #include <linux/sunrpc/xprtsock.h>
32
33 #include "netns.h"
34
35 #ifdef RPC_DEBUG
36 # define RPCDBG_FACILITY RPCDBG_BIND
37 #endif
38
39 #define RPCBIND_SOCK_PATHNAME "/var/run/rpcbind.sock"
40
41 #define RPCBIND_PROGRAM (100000u)
42 #define RPCBIND_PORT (111u)
43
44 #define RPCBVERS_2 (2u)
45 #define RPCBVERS_3 (3u)
46 #define RPCBVERS_4 (4u)
47
48 enum {
49 RPCBPROC_NULL,
50 RPCBPROC_SET,
51 RPCBPROC_UNSET,
52 RPCBPROC_GETPORT,
53 RPCBPROC_GETADDR = 3, /* alias for GETPORT */
54 RPCBPROC_DUMP,
55 RPCBPROC_CALLIT,
56 RPCBPROC_BCAST = 5, /* alias for CALLIT */
57 RPCBPROC_GETTIME,
58 RPCBPROC_UADDR2TADDR,
59 RPCBPROC_TADDR2UADDR,
60 RPCBPROC_GETVERSADDR,
61 RPCBPROC_INDIRECT,
62 RPCBPROC_GETADDRLIST,
63 RPCBPROC_GETSTAT,
64 };
65
66 /*
67 * r_owner
68 *
69 * The "owner" is allowed to unset a service in the rpcbind database.
70 *
71 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
72 * UID which it maps to a local user name via a password lookup.
73 * In all other cases it is ignored.
74 *
75 * For SET/UNSET requests, user space provides a value, even for
76 * network requests, and GETADDR uses an empty string. We follow
77 * those precedents here.
78 */
79 #define RPCB_OWNER_STRING "0"
80 #define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING)
81
82 /*
83 * XDR data type sizes
84 */
85 #define RPCB_program_sz (1)
86 #define RPCB_version_sz (1)
87 #define RPCB_protocol_sz (1)
88 #define RPCB_port_sz (1)
89 #define RPCB_boolean_sz (1)
90
91 #define RPCB_netid_sz (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
92 #define RPCB_addr_sz (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
93 #define RPCB_ownerstring_sz (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
94
95 /*
96 * XDR argument and result sizes
97 */
98 #define RPCB_mappingargs_sz (RPCB_program_sz + RPCB_version_sz + \
99 RPCB_protocol_sz + RPCB_port_sz)
100 #define RPCB_getaddrargs_sz (RPCB_program_sz + RPCB_version_sz + \
101 RPCB_netid_sz + RPCB_addr_sz + \
102 RPCB_ownerstring_sz)
103
104 #define RPCB_getportres_sz RPCB_port_sz
105 #define RPCB_setres_sz RPCB_boolean_sz
106
107 /*
108 * Note that RFC 1833 does not put any size restrictions on the
109 * address string returned by the remote rpcbind database.
110 */
111 #define RPCB_getaddrres_sz RPCB_addr_sz
112
113 static void rpcb_getport_done(struct rpc_task *, void *);
114 static void rpcb_map_release(void *data);
115 static const struct rpc_program rpcb_program;
116
117 struct rpcbind_args {
118 struct rpc_xprt * r_xprt;
119
120 u32 r_prog;
121 u32 r_vers;
122 u32 r_prot;
123 unsigned short r_port;
124 const char * r_netid;
125 const char * r_addr;
126 const char * r_owner;
127
128 int r_status;
129 };
130
131 static struct rpc_procinfo rpcb_procedures2[];
132 static struct rpc_procinfo rpcb_procedures3[];
133 static struct rpc_procinfo rpcb_procedures4[];
134
135 struct rpcb_info {
136 u32 rpc_vers;
137 struct rpc_procinfo * rpc_proc;
138 };
139
140 static const struct rpcb_info rpcb_next_version[];
141 static const struct rpcb_info rpcb_next_version6[];
142
143 static const struct rpc_call_ops rpcb_getport_ops = {
144 .rpc_call_done = rpcb_getport_done,
145 .rpc_release = rpcb_map_release,
146 };
147
rpcb_wake_rpcbind_waiters(struct rpc_xprt * xprt,int status)148 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
149 {
150 xprt_clear_binding(xprt);
151 rpc_wake_up_status(&xprt->binding, status);
152 }
153
rpcb_map_release(void * data)154 static void rpcb_map_release(void *data)
155 {
156 struct rpcbind_args *map = data;
157
158 rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
159 xprt_put(map->r_xprt);
160 kfree(map->r_addr);
161 kfree(map);
162 }
163
rpcb_get_local(struct net * net)164 static int rpcb_get_local(struct net *net)
165 {
166 int cnt;
167 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
168
169 spin_lock(&sn->rpcb_clnt_lock);
170 if (sn->rpcb_users)
171 sn->rpcb_users++;
172 cnt = sn->rpcb_users;
173 spin_unlock(&sn->rpcb_clnt_lock);
174
175 return cnt;
176 }
177
rpcb_put_local(struct net * net)178 void rpcb_put_local(struct net *net)
179 {
180 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
181 struct rpc_clnt *clnt = sn->rpcb_local_clnt;
182 struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
183 int shutdown = 0;
184
185 spin_lock(&sn->rpcb_clnt_lock);
186 if (sn->rpcb_users) {
187 if (--sn->rpcb_users == 0) {
188 sn->rpcb_local_clnt = NULL;
189 sn->rpcb_local_clnt4 = NULL;
190 }
191 shutdown = !sn->rpcb_users;
192 }
193 spin_unlock(&sn->rpcb_clnt_lock);
194
195 if (shutdown) {
196 /*
197 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
198 */
199 if (clnt4)
200 rpc_shutdown_client(clnt4);
201 if (clnt)
202 rpc_shutdown_client(clnt);
203 }
204 }
205
rpcb_set_local(struct net * net,struct rpc_clnt * clnt,struct rpc_clnt * clnt4)206 static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
207 struct rpc_clnt *clnt4)
208 {
209 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
210
211 /* Protected by rpcb_create_local_mutex */
212 sn->rpcb_local_clnt = clnt;
213 sn->rpcb_local_clnt4 = clnt4;
214 smp_wmb();
215 sn->rpcb_users = 1;
216 dprintk("RPC: created new rpcb local clients (rpcb_local_clnt: "
217 "%p, rpcb_local_clnt4: %p) for net %p%s\n",
218 sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
219 net, (net == &init_net) ? " (init_net)" : "");
220 }
221
222 /*
223 * Returns zero on success, otherwise a negative errno value
224 * is returned.
225 */
rpcb_create_local_unix(struct net * net)226 static int rpcb_create_local_unix(struct net *net)
227 {
228 static const struct sockaddr_un rpcb_localaddr_rpcbind = {
229 .sun_family = AF_LOCAL,
230 .sun_path = RPCBIND_SOCK_PATHNAME,
231 };
232 struct rpc_create_args args = {
233 .net = net,
234 .protocol = XPRT_TRANSPORT_LOCAL,
235 .address = (struct sockaddr *)&rpcb_localaddr_rpcbind,
236 .addrsize = sizeof(rpcb_localaddr_rpcbind),
237 .servername = "localhost",
238 .program = &rpcb_program,
239 .version = RPCBVERS_2,
240 .authflavor = RPC_AUTH_NULL,
241 };
242 struct rpc_clnt *clnt, *clnt4;
243 int result = 0;
244
245 /*
246 * Because we requested an RPC PING at transport creation time,
247 * this works only if the user space portmapper is rpcbind, and
248 * it's listening on AF_LOCAL on the named socket.
249 */
250 clnt = rpc_create(&args);
251 if (IS_ERR(clnt)) {
252 dprintk("RPC: failed to create AF_LOCAL rpcbind "
253 "client (errno %ld).\n", PTR_ERR(clnt));
254 result = PTR_ERR(clnt);
255 goto out;
256 }
257
258 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
259 if (IS_ERR(clnt4)) {
260 dprintk("RPC: failed to bind second program to "
261 "rpcbind v4 client (errno %ld).\n",
262 PTR_ERR(clnt4));
263 clnt4 = NULL;
264 }
265
266 rpcb_set_local(net, clnt, clnt4);
267
268 out:
269 return result;
270 }
271
272 /*
273 * Returns zero on success, otherwise a negative errno value
274 * is returned.
275 */
rpcb_create_local_net(struct net * net)276 static int rpcb_create_local_net(struct net *net)
277 {
278 static const struct sockaddr_in rpcb_inaddr_loopback = {
279 .sin_family = AF_INET,
280 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
281 .sin_port = htons(RPCBIND_PORT),
282 };
283 struct rpc_create_args args = {
284 .net = net,
285 .protocol = XPRT_TRANSPORT_TCP,
286 .address = (struct sockaddr *)&rpcb_inaddr_loopback,
287 .addrsize = sizeof(rpcb_inaddr_loopback),
288 .servername = "localhost",
289 .program = &rpcb_program,
290 .version = RPCBVERS_2,
291 .authflavor = RPC_AUTH_UNIX,
292 .flags = RPC_CLNT_CREATE_NOPING,
293 };
294 struct rpc_clnt *clnt, *clnt4;
295 int result = 0;
296
297 clnt = rpc_create(&args);
298 if (IS_ERR(clnt)) {
299 dprintk("RPC: failed to create local rpcbind "
300 "client (errno %ld).\n", PTR_ERR(clnt));
301 result = PTR_ERR(clnt);
302 goto out;
303 }
304
305 /*
306 * This results in an RPC ping. On systems running portmapper,
307 * the v4 ping will fail. Proceed anyway, but disallow rpcb
308 * v4 upcalls.
309 */
310 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
311 if (IS_ERR(clnt4)) {
312 dprintk("RPC: failed to bind second program to "
313 "rpcbind v4 client (errno %ld).\n",
314 PTR_ERR(clnt4));
315 clnt4 = NULL;
316 }
317
318 rpcb_set_local(net, clnt, clnt4);
319
320 out:
321 return result;
322 }
323
324 /*
325 * Returns zero on success, otherwise a negative errno value
326 * is returned.
327 */
rpcb_create_local(struct net * net)328 int rpcb_create_local(struct net *net)
329 {
330 static DEFINE_MUTEX(rpcb_create_local_mutex);
331 int result = 0;
332
333 if (rpcb_get_local(net))
334 return result;
335
336 mutex_lock(&rpcb_create_local_mutex);
337 if (rpcb_get_local(net))
338 goto out;
339
340 if (rpcb_create_local_unix(net) != 0)
341 result = rpcb_create_local_net(net);
342
343 out:
344 mutex_unlock(&rpcb_create_local_mutex);
345 return result;
346 }
347
rpcb_create(struct net * net,const char * hostname,struct sockaddr * srvaddr,size_t salen,int proto,u32 version)348 static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname,
349 struct sockaddr *srvaddr, size_t salen,
350 int proto, u32 version)
351 {
352 struct rpc_create_args args = {
353 .net = net,
354 .protocol = proto,
355 .address = srvaddr,
356 .addrsize = salen,
357 .servername = hostname,
358 .program = &rpcb_program,
359 .version = version,
360 .authflavor = RPC_AUTH_UNIX,
361 .flags = (RPC_CLNT_CREATE_NOPING |
362 RPC_CLNT_CREATE_NONPRIVPORT),
363 };
364
365 switch (srvaddr->sa_family) {
366 case AF_INET:
367 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
368 break;
369 case AF_INET6:
370 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
371 break;
372 default:
373 return ERR_PTR(-EAFNOSUPPORT);
374 }
375
376 return rpc_create(&args);
377 }
378
rpcb_register_call(struct rpc_clnt * clnt,struct rpc_message * msg)379 static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
380 {
381 int result, error = 0;
382
383 msg->rpc_resp = &result;
384
385 error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
386 if (error < 0) {
387 dprintk("RPC: failed to contact local rpcbind "
388 "server (errno %d).\n", -error);
389 return error;
390 }
391
392 if (!result)
393 return -EACCES;
394 return 0;
395 }
396
397 /**
398 * rpcb_register - set or unset a port registration with the local rpcbind svc
399 * @prog: RPC program number to bind
400 * @vers: RPC version number to bind
401 * @prot: transport protocol to register
402 * @port: port value to register
403 *
404 * Returns zero if the registration request was dispatched successfully
405 * and the rpcbind daemon returned success. Otherwise, returns an errno
406 * value that reflects the nature of the error (request could not be
407 * dispatched, timed out, or rpcbind returned an error).
408 *
409 * RPC services invoke this function to advertise their contact
410 * information via the system's rpcbind daemon. RPC services
411 * invoke this function once for each [program, version, transport]
412 * tuple they wish to advertise.
413 *
414 * Callers may also unregister RPC services that are no longer
415 * available by setting the passed-in port to zero. This removes
416 * all registered transports for [program, version] from the local
417 * rpcbind database.
418 *
419 * This function uses rpcbind protocol version 2 to contact the
420 * local rpcbind daemon.
421 *
422 * Registration works over both AF_INET and AF_INET6, and services
423 * registered via this function are advertised as available for any
424 * address. If the local rpcbind daemon is listening on AF_INET6,
425 * services registered via this function will be advertised on
426 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
427 * addresses).
428 */
rpcb_register(struct net * net,u32 prog,u32 vers,int prot,unsigned short port)429 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
430 {
431 struct rpcbind_args map = {
432 .r_prog = prog,
433 .r_vers = vers,
434 .r_prot = prot,
435 .r_port = port,
436 };
437 struct rpc_message msg = {
438 .rpc_argp = &map,
439 };
440 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
441
442 dprintk("RPC: %sregistering (%u, %u, %d, %u) with local "
443 "rpcbind\n", (port ? "" : "un"),
444 prog, vers, prot, port);
445
446 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
447 if (port)
448 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
449
450 return rpcb_register_call(sn->rpcb_local_clnt, &msg);
451 }
452
453 /*
454 * Fill in AF_INET family-specific arguments to register
455 */
rpcb_register_inet4(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)456 static int rpcb_register_inet4(struct sunrpc_net *sn,
457 const struct sockaddr *sap,
458 struct rpc_message *msg)
459 {
460 const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
461 struct rpcbind_args *map = msg->rpc_argp;
462 unsigned short port = ntohs(sin->sin_port);
463 int result;
464
465 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
466
467 dprintk("RPC: %sregistering [%u, %u, %s, '%s'] with "
468 "local rpcbind\n", (port ? "" : "un"),
469 map->r_prog, map->r_vers,
470 map->r_addr, map->r_netid);
471
472 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
473 if (port)
474 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
475
476 result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
477 kfree(map->r_addr);
478 return result;
479 }
480
481 /*
482 * Fill in AF_INET6 family-specific arguments to register
483 */
rpcb_register_inet6(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)484 static int rpcb_register_inet6(struct sunrpc_net *sn,
485 const struct sockaddr *sap,
486 struct rpc_message *msg)
487 {
488 const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
489 struct rpcbind_args *map = msg->rpc_argp;
490 unsigned short port = ntohs(sin6->sin6_port);
491 int result;
492
493 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
494
495 dprintk("RPC: %sregistering [%u, %u, %s, '%s'] with "
496 "local rpcbind\n", (port ? "" : "un"),
497 map->r_prog, map->r_vers,
498 map->r_addr, map->r_netid);
499
500 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
501 if (port)
502 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
503
504 result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
505 kfree(map->r_addr);
506 return result;
507 }
508
rpcb_unregister_all_protofamilies(struct sunrpc_net * sn,struct rpc_message * msg)509 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
510 struct rpc_message *msg)
511 {
512 struct rpcbind_args *map = msg->rpc_argp;
513
514 dprintk("RPC: unregistering [%u, %u, '%s'] with "
515 "local rpcbind\n",
516 map->r_prog, map->r_vers, map->r_netid);
517
518 map->r_addr = "";
519 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
520
521 return rpcb_register_call(sn->rpcb_local_clnt4, msg);
522 }
523
524 /**
525 * rpcb_v4_register - set or unset a port registration with the local rpcbind
526 * @program: RPC program number of service to (un)register
527 * @version: RPC version number of service to (un)register
528 * @address: address family, IP address, and port to (un)register
529 * @netid: netid of transport protocol to (un)register
530 *
531 * Returns zero if the registration request was dispatched successfully
532 * and the rpcbind daemon returned success. Otherwise, returns an errno
533 * value that reflects the nature of the error (request could not be
534 * dispatched, timed out, or rpcbind returned an error).
535 *
536 * RPC services invoke this function to advertise their contact
537 * information via the system's rpcbind daemon. RPC services
538 * invoke this function once for each [program, version, address,
539 * netid] tuple they wish to advertise.
540 *
541 * Callers may also unregister RPC services that are registered at a
542 * specific address by setting the port number in @address to zero.
543 * They may unregister all registered protocol families at once for
544 * a service by passing a NULL @address argument. If @netid is ""
545 * then all netids for [program, version, address] are unregistered.
546 *
547 * This function uses rpcbind protocol version 4 to contact the
548 * local rpcbind daemon. The local rpcbind daemon must support
549 * version 4 of the rpcbind protocol in order for these functions
550 * to register a service successfully.
551 *
552 * Supported netids include "udp" and "tcp" for UDP and TCP over
553 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
554 * respectively.
555 *
556 * The contents of @address determine the address family and the
557 * port to be registered. The usual practice is to pass INADDR_ANY
558 * as the raw address, but specifying a non-zero address is also
559 * supported by this API if the caller wishes to advertise an RPC
560 * service on a specific network interface.
561 *
562 * Note that passing in INADDR_ANY does not create the same service
563 * registration as IN6ADDR_ANY. The former advertises an RPC
564 * service on any IPv4 address, but not on IPv6. The latter
565 * advertises the service on all IPv4 and IPv6 addresses.
566 */
rpcb_v4_register(struct net * net,const u32 program,const u32 version,const struct sockaddr * address,const char * netid)567 int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
568 const struct sockaddr *address, const char *netid)
569 {
570 struct rpcbind_args map = {
571 .r_prog = program,
572 .r_vers = version,
573 .r_netid = netid,
574 .r_owner = RPCB_OWNER_STRING,
575 };
576 struct rpc_message msg = {
577 .rpc_argp = &map,
578 };
579 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
580
581 if (sn->rpcb_local_clnt4 == NULL)
582 return -EPROTONOSUPPORT;
583
584 if (address == NULL)
585 return rpcb_unregister_all_protofamilies(sn, &msg);
586
587 switch (address->sa_family) {
588 case AF_INET:
589 return rpcb_register_inet4(sn, address, &msg);
590 case AF_INET6:
591 return rpcb_register_inet6(sn, address, &msg);
592 }
593
594 return -EAFNOSUPPORT;
595 }
596
rpcb_call_async(struct rpc_clnt * rpcb_clnt,struct rpcbind_args * map,struct rpc_procinfo * proc)597 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
598 {
599 struct rpc_message msg = {
600 .rpc_proc = proc,
601 .rpc_argp = map,
602 .rpc_resp = map,
603 };
604 struct rpc_task_setup task_setup_data = {
605 .rpc_client = rpcb_clnt,
606 .rpc_message = &msg,
607 .callback_ops = &rpcb_getport_ops,
608 .callback_data = map,
609 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
610 };
611
612 return rpc_run_task(&task_setup_data);
613 }
614
615 /*
616 * In the case where rpc clients have been cloned, we want to make
617 * sure that we use the program number/version etc of the actual
618 * owner of the xprt. To do so, we walk back up the tree of parents
619 * to find whoever created the transport and/or whoever has the
620 * autobind flag set.
621 */
rpcb_find_transport_owner(struct rpc_clnt * clnt)622 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
623 {
624 struct rpc_clnt *parent = clnt->cl_parent;
625 struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
626
627 while (parent != clnt) {
628 if (rcu_dereference(parent->cl_xprt) != xprt)
629 break;
630 if (clnt->cl_autobind)
631 break;
632 clnt = parent;
633 parent = parent->cl_parent;
634 }
635 return clnt;
636 }
637
638 /**
639 * rpcb_getport_async - obtain the port for a given RPC service on a given host
640 * @task: task that is waiting for portmapper request
641 *
642 * This one can be called for an ongoing RPC request, and can be used in
643 * an async (rpciod) context.
644 */
rpcb_getport_async(struct rpc_task * task)645 void rpcb_getport_async(struct rpc_task *task)
646 {
647 struct rpc_clnt *clnt;
648 struct rpc_procinfo *proc;
649 u32 bind_version;
650 struct rpc_xprt *xprt;
651 struct rpc_clnt *rpcb_clnt;
652 struct rpcbind_args *map;
653 struct rpc_task *child;
654 struct sockaddr_storage addr;
655 struct sockaddr *sap = (struct sockaddr *)&addr;
656 size_t salen;
657 int status;
658
659 rcu_read_lock();
660 do {
661 clnt = rpcb_find_transport_owner(task->tk_client);
662 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
663 } while (xprt == NULL);
664 rcu_read_unlock();
665
666 dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
667 task->tk_pid, __func__,
668 xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
669
670 /* Put self on the wait queue to ensure we get notified if
671 * some other task is already attempting to bind the port */
672 rpc_sleep_on(&xprt->binding, task, NULL);
673
674 if (xprt_test_and_set_binding(xprt)) {
675 dprintk("RPC: %5u %s: waiting for another binder\n",
676 task->tk_pid, __func__);
677 xprt_put(xprt);
678 return;
679 }
680
681 /* Someone else may have bound if we slept */
682 if (xprt_bound(xprt)) {
683 status = 0;
684 dprintk("RPC: %5u %s: already bound\n",
685 task->tk_pid, __func__);
686 goto bailout_nofree;
687 }
688
689 /* Parent transport's destination address */
690 salen = rpc_peeraddr(clnt, sap, sizeof(addr));
691
692 /* Don't ever use rpcbind v2 for AF_INET6 requests */
693 switch (sap->sa_family) {
694 case AF_INET:
695 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
696 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
697 break;
698 case AF_INET6:
699 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
700 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
701 break;
702 default:
703 status = -EAFNOSUPPORT;
704 dprintk("RPC: %5u %s: bad address family\n",
705 task->tk_pid, __func__);
706 goto bailout_nofree;
707 }
708 if (proc == NULL) {
709 xprt->bind_index = 0;
710 status = -EPFNOSUPPORT;
711 dprintk("RPC: %5u %s: no more getport versions available\n",
712 task->tk_pid, __func__);
713 goto bailout_nofree;
714 }
715
716 dprintk("RPC: %5u %s: trying rpcbind version %u\n",
717 task->tk_pid, __func__, bind_version);
718
719 rpcb_clnt = rpcb_create(xprt->xprt_net, xprt->servername, sap, salen,
720 xprt->prot, bind_version);
721 if (IS_ERR(rpcb_clnt)) {
722 status = PTR_ERR(rpcb_clnt);
723 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
724 task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
725 goto bailout_nofree;
726 }
727
728 map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
729 if (!map) {
730 status = -ENOMEM;
731 dprintk("RPC: %5u %s: no memory available\n",
732 task->tk_pid, __func__);
733 goto bailout_release_client;
734 }
735 map->r_prog = clnt->cl_prog;
736 map->r_vers = clnt->cl_vers;
737 map->r_prot = xprt->prot;
738 map->r_port = 0;
739 map->r_xprt = xprt;
740 map->r_status = -EIO;
741
742 switch (bind_version) {
743 case RPCBVERS_4:
744 case RPCBVERS_3:
745 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
746 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
747 map->r_owner = "";
748 break;
749 case RPCBVERS_2:
750 map->r_addr = NULL;
751 break;
752 default:
753 BUG();
754 }
755
756 child = rpcb_call_async(rpcb_clnt, map, proc);
757 rpc_release_client(rpcb_clnt);
758 if (IS_ERR(child)) {
759 /* rpcb_map_release() has freed the arguments */
760 dprintk("RPC: %5u %s: rpc_run_task failed\n",
761 task->tk_pid, __func__);
762 return;
763 }
764
765 xprt->stat.bind_count++;
766 rpc_put_task(child);
767 return;
768
769 bailout_release_client:
770 rpc_release_client(rpcb_clnt);
771 bailout_nofree:
772 rpcb_wake_rpcbind_waiters(xprt, status);
773 task->tk_status = status;
774 xprt_put(xprt);
775 }
776 EXPORT_SYMBOL_GPL(rpcb_getport_async);
777
778 /*
779 * Rpcbind child task calls this callback via tk_exit.
780 */
rpcb_getport_done(struct rpc_task * child,void * data)781 static void rpcb_getport_done(struct rpc_task *child, void *data)
782 {
783 struct rpcbind_args *map = data;
784 struct rpc_xprt *xprt = map->r_xprt;
785 int status = child->tk_status;
786
787 /* Garbage reply: retry with a lesser rpcbind version */
788 if (status == -EIO)
789 status = -EPROTONOSUPPORT;
790
791 /* rpcbind server doesn't support this rpcbind protocol version */
792 if (status == -EPROTONOSUPPORT)
793 xprt->bind_index++;
794
795 if (status < 0) {
796 /* rpcbind server not available on remote host? */
797 xprt->ops->set_port(xprt, 0);
798 } else if (map->r_port == 0) {
799 /* Requested RPC service wasn't registered on remote host */
800 xprt->ops->set_port(xprt, 0);
801 status = -EACCES;
802 } else {
803 /* Succeeded */
804 xprt->ops->set_port(xprt, map->r_port);
805 xprt_set_bound(xprt);
806 status = 0;
807 }
808
809 dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
810 child->tk_pid, status, map->r_port);
811
812 map->r_status = status;
813 }
814
815 /*
816 * XDR functions for rpcbind
817 */
818
rpcb_enc_mapping(struct rpc_rqst * req,struct xdr_stream * xdr,const struct rpcbind_args * rpcb)819 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
820 const struct rpcbind_args *rpcb)
821 {
822 __be32 *p;
823
824 dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
825 req->rq_task->tk_pid,
826 req->rq_task->tk_msg.rpc_proc->p_name,
827 rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
828
829 p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
830 *p++ = cpu_to_be32(rpcb->r_prog);
831 *p++ = cpu_to_be32(rpcb->r_vers);
832 *p++ = cpu_to_be32(rpcb->r_prot);
833 *p = cpu_to_be32(rpcb->r_port);
834 }
835
rpcb_dec_getport(struct rpc_rqst * req,struct xdr_stream * xdr,struct rpcbind_args * rpcb)836 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
837 struct rpcbind_args *rpcb)
838 {
839 unsigned long port;
840 __be32 *p;
841
842 rpcb->r_port = 0;
843
844 p = xdr_inline_decode(xdr, 4);
845 if (unlikely(p == NULL))
846 return -EIO;
847
848 port = be32_to_cpup(p);
849 dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
850 req->rq_task->tk_msg.rpc_proc->p_name, port);
851 if (unlikely(port > USHRT_MAX))
852 return -EIO;
853
854 rpcb->r_port = port;
855 return 0;
856 }
857
rpcb_dec_set(struct rpc_rqst * req,struct xdr_stream * xdr,unsigned int * boolp)858 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
859 unsigned int *boolp)
860 {
861 __be32 *p;
862
863 p = xdr_inline_decode(xdr, 4);
864 if (unlikely(p == NULL))
865 return -EIO;
866
867 *boolp = 0;
868 if (*p != xdr_zero)
869 *boolp = 1;
870
871 dprintk("RPC: %5u RPCB_%s call %s\n",
872 req->rq_task->tk_pid,
873 req->rq_task->tk_msg.rpc_proc->p_name,
874 (*boolp ? "succeeded" : "failed"));
875 return 0;
876 }
877
encode_rpcb_string(struct xdr_stream * xdr,const char * string,const u32 maxstrlen)878 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
879 const u32 maxstrlen)
880 {
881 __be32 *p;
882 u32 len;
883
884 len = strlen(string);
885 BUG_ON(len > maxstrlen);
886 p = xdr_reserve_space(xdr, 4 + len);
887 xdr_encode_opaque(p, string, len);
888 }
889
rpcb_enc_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,const struct rpcbind_args * rpcb)890 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
891 const struct rpcbind_args *rpcb)
892 {
893 __be32 *p;
894
895 dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
896 req->rq_task->tk_pid,
897 req->rq_task->tk_msg.rpc_proc->p_name,
898 rpcb->r_prog, rpcb->r_vers,
899 rpcb->r_netid, rpcb->r_addr);
900
901 p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
902 *p++ = cpu_to_be32(rpcb->r_prog);
903 *p = cpu_to_be32(rpcb->r_vers);
904
905 encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
906 encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
907 encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
908 }
909
rpcb_dec_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,struct rpcbind_args * rpcb)910 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
911 struct rpcbind_args *rpcb)
912 {
913 struct sockaddr_storage address;
914 struct sockaddr *sap = (struct sockaddr *)&address;
915 __be32 *p;
916 u32 len;
917
918 rpcb->r_port = 0;
919
920 p = xdr_inline_decode(xdr, 4);
921 if (unlikely(p == NULL))
922 goto out_fail;
923 len = be32_to_cpup(p);
924
925 /*
926 * If the returned universal address is a null string,
927 * the requested RPC service was not registered.
928 */
929 if (len == 0) {
930 dprintk("RPC: %5u RPCB reply: program not registered\n",
931 req->rq_task->tk_pid);
932 return 0;
933 }
934
935 if (unlikely(len > RPCBIND_MAXUADDRLEN))
936 goto out_fail;
937
938 p = xdr_inline_decode(xdr, len);
939 if (unlikely(p == NULL))
940 goto out_fail;
941 dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
942 req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
943
944 if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
945 sap, sizeof(address)) == 0)
946 goto out_fail;
947 rpcb->r_port = rpc_get_port(sap);
948
949 return 0;
950
951 out_fail:
952 dprintk("RPC: %5u malformed RPCB_%s reply\n",
953 req->rq_task->tk_pid,
954 req->rq_task->tk_msg.rpc_proc->p_name);
955 return -EIO;
956 }
957
958 /*
959 * Not all rpcbind procedures described in RFC 1833 are implemented
960 * since the Linux kernel RPC code requires only these.
961 */
962
963 static struct rpc_procinfo rpcb_procedures2[] = {
964 [RPCBPROC_SET] = {
965 .p_proc = RPCBPROC_SET,
966 .p_encode = (kxdreproc_t)rpcb_enc_mapping,
967 .p_decode = (kxdrdproc_t)rpcb_dec_set,
968 .p_arglen = RPCB_mappingargs_sz,
969 .p_replen = RPCB_setres_sz,
970 .p_statidx = RPCBPROC_SET,
971 .p_timer = 0,
972 .p_name = "SET",
973 },
974 [RPCBPROC_UNSET] = {
975 .p_proc = RPCBPROC_UNSET,
976 .p_encode = (kxdreproc_t)rpcb_enc_mapping,
977 .p_decode = (kxdrdproc_t)rpcb_dec_set,
978 .p_arglen = RPCB_mappingargs_sz,
979 .p_replen = RPCB_setres_sz,
980 .p_statidx = RPCBPROC_UNSET,
981 .p_timer = 0,
982 .p_name = "UNSET",
983 },
984 [RPCBPROC_GETPORT] = {
985 .p_proc = RPCBPROC_GETPORT,
986 .p_encode = (kxdreproc_t)rpcb_enc_mapping,
987 .p_decode = (kxdrdproc_t)rpcb_dec_getport,
988 .p_arglen = RPCB_mappingargs_sz,
989 .p_replen = RPCB_getportres_sz,
990 .p_statidx = RPCBPROC_GETPORT,
991 .p_timer = 0,
992 .p_name = "GETPORT",
993 },
994 };
995
996 static struct rpc_procinfo rpcb_procedures3[] = {
997 [RPCBPROC_SET] = {
998 .p_proc = RPCBPROC_SET,
999 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1000 .p_decode = (kxdrdproc_t)rpcb_dec_set,
1001 .p_arglen = RPCB_getaddrargs_sz,
1002 .p_replen = RPCB_setres_sz,
1003 .p_statidx = RPCBPROC_SET,
1004 .p_timer = 0,
1005 .p_name = "SET",
1006 },
1007 [RPCBPROC_UNSET] = {
1008 .p_proc = RPCBPROC_UNSET,
1009 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1010 .p_decode = (kxdrdproc_t)rpcb_dec_set,
1011 .p_arglen = RPCB_getaddrargs_sz,
1012 .p_replen = RPCB_setres_sz,
1013 .p_statidx = RPCBPROC_UNSET,
1014 .p_timer = 0,
1015 .p_name = "UNSET",
1016 },
1017 [RPCBPROC_GETADDR] = {
1018 .p_proc = RPCBPROC_GETADDR,
1019 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1020 .p_decode = (kxdrdproc_t)rpcb_dec_getaddr,
1021 .p_arglen = RPCB_getaddrargs_sz,
1022 .p_replen = RPCB_getaddrres_sz,
1023 .p_statidx = RPCBPROC_GETADDR,
1024 .p_timer = 0,
1025 .p_name = "GETADDR",
1026 },
1027 };
1028
1029 static struct rpc_procinfo rpcb_procedures4[] = {
1030 [RPCBPROC_SET] = {
1031 .p_proc = RPCBPROC_SET,
1032 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1033 .p_decode = (kxdrdproc_t)rpcb_dec_set,
1034 .p_arglen = RPCB_getaddrargs_sz,
1035 .p_replen = RPCB_setres_sz,
1036 .p_statidx = RPCBPROC_SET,
1037 .p_timer = 0,
1038 .p_name = "SET",
1039 },
1040 [RPCBPROC_UNSET] = {
1041 .p_proc = RPCBPROC_UNSET,
1042 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1043 .p_decode = (kxdrdproc_t)rpcb_dec_set,
1044 .p_arglen = RPCB_getaddrargs_sz,
1045 .p_replen = RPCB_setres_sz,
1046 .p_statidx = RPCBPROC_UNSET,
1047 .p_timer = 0,
1048 .p_name = "UNSET",
1049 },
1050 [RPCBPROC_GETADDR] = {
1051 .p_proc = RPCBPROC_GETADDR,
1052 .p_encode = (kxdreproc_t)rpcb_enc_getaddr,
1053 .p_decode = (kxdrdproc_t)rpcb_dec_getaddr,
1054 .p_arglen = RPCB_getaddrargs_sz,
1055 .p_replen = RPCB_getaddrres_sz,
1056 .p_statidx = RPCBPROC_GETADDR,
1057 .p_timer = 0,
1058 .p_name = "GETADDR",
1059 },
1060 };
1061
1062 static const struct rpcb_info rpcb_next_version[] = {
1063 {
1064 .rpc_vers = RPCBVERS_2,
1065 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT],
1066 },
1067 {
1068 .rpc_proc = NULL,
1069 },
1070 };
1071
1072 static const struct rpcb_info rpcb_next_version6[] = {
1073 {
1074 .rpc_vers = RPCBVERS_4,
1075 .rpc_proc = &rpcb_procedures4[RPCBPROC_GETADDR],
1076 },
1077 {
1078 .rpc_vers = RPCBVERS_3,
1079 .rpc_proc = &rpcb_procedures3[RPCBPROC_GETADDR],
1080 },
1081 {
1082 .rpc_proc = NULL,
1083 },
1084 };
1085
1086 static const struct rpc_version rpcb_version2 = {
1087 .number = RPCBVERS_2,
1088 .nrprocs = ARRAY_SIZE(rpcb_procedures2),
1089 .procs = rpcb_procedures2
1090 };
1091
1092 static const struct rpc_version rpcb_version3 = {
1093 .number = RPCBVERS_3,
1094 .nrprocs = ARRAY_SIZE(rpcb_procedures3),
1095 .procs = rpcb_procedures3
1096 };
1097
1098 static const struct rpc_version rpcb_version4 = {
1099 .number = RPCBVERS_4,
1100 .nrprocs = ARRAY_SIZE(rpcb_procedures4),
1101 .procs = rpcb_procedures4
1102 };
1103
1104 static const struct rpc_version *rpcb_version[] = {
1105 NULL,
1106 NULL,
1107 &rpcb_version2,
1108 &rpcb_version3,
1109 &rpcb_version4
1110 };
1111
1112 static struct rpc_stat rpcb_stats;
1113
1114 static const struct rpc_program rpcb_program = {
1115 .name = "rpcbind",
1116 .number = RPCBIND_PROGRAM,
1117 .nrvers = ARRAY_SIZE(rpcb_version),
1118 .version = rpcb_version,
1119 .stats = &rpcb_stats,
1120 };
1121