1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
4 * protocol
5 *
6 * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
7 * RFC 3530: "Network File System (NFS) version 4 Protocol"
8 *
9 * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
10 * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
11 *
12 * Descended from net/sunrpc/pmap_clnt.c,
13 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
14 */
15
16 #include <linux/module.h>
17
18 #include <linux/types.h>
19 #include <linux/socket.h>
20 #include <linux/un.h>
21 #include <linux/in.h>
22 #include <linux/in6.h>
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/mutex.h>
26 #include <linux/slab.h>
27 #include <net/ipv6.h>
28
29 #include <linux/sunrpc/clnt.h>
30 #include <linux/sunrpc/addr.h>
31 #include <linux/sunrpc/sched.h>
32 #include <linux/sunrpc/xprtsock.h>
33
34 #include <trace/events/sunrpc.h>
35
36 #include "netns.h"
37
38 #define RPCBIND_SOCK_PATHNAME "/var/run/rpcbind.sock"
39 #define RPCBIND_SOCK_ABSTRACT_NAME "\0/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 const struct rpc_procinfo rpcb_procedures2[];
132 static const struct rpc_procinfo rpcb_procedures3[];
133 static const struct rpc_procinfo rpcb_procedures4[];
134
135 struct rpcb_info {
136 u32 rpc_vers;
137 const 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,bool is_af_local)206 static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
207 struct rpc_clnt *clnt4,
208 bool is_af_local)
209 {
210 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
211
212 /* Protected by rpcb_create_local_mutex */
213 sn->rpcb_local_clnt = clnt;
214 sn->rpcb_local_clnt4 = clnt4;
215 sn->rpcb_is_af_local = is_af_local ? 1 : 0;
216 smp_wmb();
217 sn->rpcb_users = 1;
218 }
219
220 /* Evaluate to actual length of the `sockaddr_un' structure. */
221 # define SUN_LEN(ptr) (offsetof(struct sockaddr_un, sun_path) \
222 + 1 + strlen((ptr)->sun_path + 1))
223
224 /*
225 * Returns zero on success, otherwise a negative errno value
226 * is returned.
227 */
rpcb_create_af_local(struct net * net,const struct sockaddr_un * addr)228 static int rpcb_create_af_local(struct net *net,
229 const struct sockaddr_un *addr)
230 {
231 struct rpc_create_args args = {
232 .net = net,
233 .protocol = XPRT_TRANSPORT_LOCAL,
234 .address = (struct sockaddr *)addr,
235 .addrsize = SUN_LEN(addr),
236 .servername = "localhost",
237 .program = &rpcb_program,
238 .version = RPCBVERS_2,
239 .authflavor = RPC_AUTH_NULL,
240 .cred = current_cred(),
241 /*
242 * We turn off the idle timeout to prevent the kernel
243 * from automatically disconnecting the socket.
244 * Otherwise, we'd have to cache the mount namespace
245 * of the caller and somehow pass that to the socket
246 * reconnect code.
247 */
248 .flags = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
249 };
250 struct rpc_clnt *clnt, *clnt4;
251 int result = 0;
252
253 /*
254 * Because we requested an RPC PING at transport creation time,
255 * this works only if the user space portmapper is rpcbind, and
256 * it's listening on AF_LOCAL on the named socket.
257 */
258 clnt = rpc_create(&args);
259 if (IS_ERR(clnt)) {
260 result = PTR_ERR(clnt);
261 goto out;
262 }
263
264 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
265 if (IS_ERR(clnt4))
266 clnt4 = NULL;
267
268 rpcb_set_local(net, clnt, clnt4, true);
269
270 out:
271 return result;
272 }
273
rpcb_create_local_abstract(struct net * net)274 static int rpcb_create_local_abstract(struct net *net)
275 {
276 static const struct sockaddr_un rpcb_localaddr_abstract = {
277 .sun_family = AF_LOCAL,
278 .sun_path = RPCBIND_SOCK_ABSTRACT_NAME,
279 };
280
281 return rpcb_create_af_local(net, &rpcb_localaddr_abstract);
282 }
283
rpcb_create_local_unix(struct net * net)284 static int rpcb_create_local_unix(struct net *net)
285 {
286 static const struct sockaddr_un rpcb_localaddr_unix = {
287 .sun_family = AF_LOCAL,
288 .sun_path = RPCBIND_SOCK_PATHNAME,
289 };
290
291 return rpcb_create_af_local(net, &rpcb_localaddr_unix);
292 }
293
294 /*
295 * Returns zero on success, otherwise a negative errno value
296 * is returned.
297 */
rpcb_create_local_net(struct net * net)298 static int rpcb_create_local_net(struct net *net)
299 {
300 static const struct sockaddr_in rpcb_inaddr_loopback = {
301 .sin_family = AF_INET,
302 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
303 .sin_port = htons(RPCBIND_PORT),
304 };
305 struct rpc_create_args args = {
306 .net = net,
307 .protocol = XPRT_TRANSPORT_TCP,
308 .address = (struct sockaddr *)&rpcb_inaddr_loopback,
309 .addrsize = sizeof(rpcb_inaddr_loopback),
310 .servername = "localhost",
311 .program = &rpcb_program,
312 .version = RPCBVERS_2,
313 .authflavor = RPC_AUTH_UNIX,
314 .cred = current_cred(),
315 .flags = RPC_CLNT_CREATE_NOPING,
316 };
317 struct rpc_clnt *clnt, *clnt4;
318 int result = 0;
319
320 clnt = rpc_create(&args);
321 if (IS_ERR(clnt)) {
322 result = PTR_ERR(clnt);
323 goto out;
324 }
325
326 /*
327 * This results in an RPC ping. On systems running portmapper,
328 * the v4 ping will fail. Proceed anyway, but disallow rpcb
329 * v4 upcalls.
330 */
331 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
332 if (IS_ERR(clnt4))
333 clnt4 = NULL;
334
335 rpcb_set_local(net, clnt, clnt4, false);
336
337 out:
338 return result;
339 }
340
341 /*
342 * Returns zero on success, otherwise a negative errno value
343 * is returned.
344 */
rpcb_create_local(struct net * net)345 int rpcb_create_local(struct net *net)
346 {
347 static DEFINE_MUTEX(rpcb_create_local_mutex);
348 int result = 0;
349
350 if (rpcb_get_local(net))
351 return result;
352
353 mutex_lock(&rpcb_create_local_mutex);
354 if (rpcb_get_local(net))
355 goto out;
356
357 if (rpcb_create_local_abstract(net) != 0 &&
358 rpcb_create_local_unix(net) != 0)
359 result = rpcb_create_local_net(net);
360
361 out:
362 mutex_unlock(&rpcb_create_local_mutex);
363 return result;
364 }
365
rpcb_create(struct net * net,const char * nodename,const char * hostname,struct sockaddr * srvaddr,size_t salen,int proto,u32 version,const struct cred * cred,const struct rpc_timeout * timeo)366 static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
367 const char *hostname,
368 struct sockaddr *srvaddr, size_t salen,
369 int proto, u32 version,
370 const struct cred *cred,
371 const struct rpc_timeout *timeo)
372 {
373 struct rpc_create_args args = {
374 .net = net,
375 .protocol = proto,
376 .address = srvaddr,
377 .addrsize = salen,
378 .timeout = timeo,
379 .servername = hostname,
380 .nodename = nodename,
381 .program = &rpcb_program,
382 .version = version,
383 .authflavor = RPC_AUTH_UNIX,
384 .cred = cred,
385 .flags = (RPC_CLNT_CREATE_NOPING |
386 RPC_CLNT_CREATE_NONPRIVPORT),
387 };
388
389 switch (srvaddr->sa_family) {
390 case AF_INET:
391 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
392 break;
393 case AF_INET6:
394 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
395 break;
396 default:
397 return ERR_PTR(-EAFNOSUPPORT);
398 }
399
400 return rpc_create(&args);
401 }
402
rpcb_register_call(struct sunrpc_net * sn,struct rpc_clnt * clnt,struct rpc_message * msg,bool is_set)403 static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
404 {
405 int flags = RPC_TASK_NOCONNECT;
406 int error, result = 0;
407
408 if (is_set || !sn->rpcb_is_af_local)
409 flags = RPC_TASK_SOFTCONN;
410 msg->rpc_resp = &result;
411
412 error = rpc_call_sync(clnt, msg, flags);
413 if (error < 0)
414 return error;
415
416 if (!result)
417 return -EACCES;
418 return 0;
419 }
420
421 /**
422 * rpcb_register - set or unset a port registration with the local rpcbind svc
423 * @net: target network namespace
424 * @prog: RPC program number to bind
425 * @vers: RPC version number to bind
426 * @prot: transport protocol to register
427 * @port: port value to register
428 *
429 * Returns zero if the registration request was dispatched successfully
430 * and the rpcbind daemon returned success. Otherwise, returns an errno
431 * value that reflects the nature of the error (request could not be
432 * dispatched, timed out, or rpcbind returned an error).
433 *
434 * RPC services invoke this function to advertise their contact
435 * information via the system's rpcbind daemon. RPC services
436 * invoke this function once for each [program, version, transport]
437 * tuple they wish to advertise.
438 *
439 * Callers may also unregister RPC services that are no longer
440 * available by setting the passed-in port to zero. This removes
441 * all registered transports for [program, version] from the local
442 * rpcbind database.
443 *
444 * This function uses rpcbind protocol version 2 to contact the
445 * local rpcbind daemon.
446 *
447 * Registration works over both AF_INET and AF_INET6, and services
448 * registered via this function are advertised as available for any
449 * address. If the local rpcbind daemon is listening on AF_INET6,
450 * services registered via this function will be advertised on
451 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
452 * addresses).
453 */
rpcb_register(struct net * net,u32 prog,u32 vers,int prot,unsigned short port)454 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
455 {
456 struct rpcbind_args map = {
457 .r_prog = prog,
458 .r_vers = vers,
459 .r_prot = prot,
460 .r_port = port,
461 };
462 struct rpc_message msg = {
463 .rpc_argp = &map,
464 };
465 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
466 bool is_set = false;
467
468 trace_pmap_register(prog, vers, prot, port);
469
470 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
471 if (port != 0) {
472 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
473 is_set = true;
474 }
475
476 return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
477 }
478
479 /*
480 * Fill in AF_INET family-specific arguments to register
481 */
rpcb_register_inet4(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)482 static int rpcb_register_inet4(struct sunrpc_net *sn,
483 const struct sockaddr *sap,
484 struct rpc_message *msg)
485 {
486 const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
487 struct rpcbind_args *map = msg->rpc_argp;
488 unsigned short port = ntohs(sin->sin_port);
489 bool is_set = false;
490 int result;
491
492 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
493
494 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
495 if (port != 0) {
496 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
497 is_set = true;
498 }
499
500 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
501 kfree(map->r_addr);
502 return result;
503 }
504
505 /*
506 * Fill in AF_INET6 family-specific arguments to register
507 */
rpcb_register_inet6(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)508 static int rpcb_register_inet6(struct sunrpc_net *sn,
509 const struct sockaddr *sap,
510 struct rpc_message *msg)
511 {
512 const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
513 struct rpcbind_args *map = msg->rpc_argp;
514 unsigned short port = ntohs(sin6->sin6_port);
515 bool is_set = false;
516 int result;
517
518 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
519
520 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
521 if (port != 0) {
522 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
523 is_set = true;
524 }
525
526 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
527 kfree(map->r_addr);
528 return result;
529 }
530
rpcb_unregister_all_protofamilies(struct sunrpc_net * sn,struct rpc_message * msg)531 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
532 struct rpc_message *msg)
533 {
534 struct rpcbind_args *map = msg->rpc_argp;
535
536 trace_rpcb_unregister(map->r_prog, map->r_vers, map->r_netid);
537
538 map->r_addr = "";
539 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
540
541 return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
542 }
543
544 /**
545 * rpcb_v4_register - set or unset a port registration with the local rpcbind
546 * @net: target network namespace
547 * @program: RPC program number of service to (un)register
548 * @version: RPC version number of service to (un)register
549 * @address: address family, IP address, and port to (un)register
550 * @netid: netid of transport protocol to (un)register
551 *
552 * Returns zero if the registration request was dispatched successfully
553 * and the rpcbind daemon returned success. Otherwise, returns an errno
554 * value that reflects the nature of the error (request could not be
555 * dispatched, timed out, or rpcbind returned an error).
556 *
557 * RPC services invoke this function to advertise their contact
558 * information via the system's rpcbind daemon. RPC services
559 * invoke this function once for each [program, version, address,
560 * netid] tuple they wish to advertise.
561 *
562 * Callers may also unregister RPC services that are registered at a
563 * specific address by setting the port number in @address to zero.
564 * They may unregister all registered protocol families at once for
565 * a service by passing a NULL @address argument. If @netid is ""
566 * then all netids for [program, version, address] are unregistered.
567 *
568 * This function uses rpcbind protocol version 4 to contact the
569 * local rpcbind daemon. The local rpcbind daemon must support
570 * version 4 of the rpcbind protocol in order for these functions
571 * to register a service successfully.
572 *
573 * Supported netids include "udp" and "tcp" for UDP and TCP over
574 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
575 * respectively.
576 *
577 * The contents of @address determine the address family and the
578 * port to be registered. The usual practice is to pass INADDR_ANY
579 * as the raw address, but specifying a non-zero address is also
580 * supported by this API if the caller wishes to advertise an RPC
581 * service on a specific network interface.
582 *
583 * Note that passing in INADDR_ANY does not create the same service
584 * registration as IN6ADDR_ANY. The former advertises an RPC
585 * service on any IPv4 address, but not on IPv6. The latter
586 * advertises the service on all IPv4 and IPv6 addresses.
587 */
rpcb_v4_register(struct net * net,const u32 program,const u32 version,const struct sockaddr * address,const char * netid)588 int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
589 const struct sockaddr *address, const char *netid)
590 {
591 struct rpcbind_args map = {
592 .r_prog = program,
593 .r_vers = version,
594 .r_netid = netid,
595 .r_owner = RPCB_OWNER_STRING,
596 };
597 struct rpc_message msg = {
598 .rpc_argp = &map,
599 };
600 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
601
602 if (sn->rpcb_local_clnt4 == NULL)
603 return -EPROTONOSUPPORT;
604
605 if (address == NULL)
606 return rpcb_unregister_all_protofamilies(sn, &msg);
607
608 trace_rpcb_register(map.r_prog, map.r_vers, map.r_addr, map.r_netid);
609
610 switch (address->sa_family) {
611 case AF_INET:
612 return rpcb_register_inet4(sn, address, &msg);
613 case AF_INET6:
614 return rpcb_register_inet6(sn, address, &msg);
615 }
616
617 return -EAFNOSUPPORT;
618 }
619
rpcb_call_async(struct rpc_clnt * rpcb_clnt,struct rpcbind_args * map,const struct rpc_procinfo * proc)620 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt,
621 struct rpcbind_args *map, const struct rpc_procinfo *proc)
622 {
623 struct rpc_message msg = {
624 .rpc_proc = proc,
625 .rpc_argp = map,
626 .rpc_resp = map,
627 };
628 struct rpc_task_setup task_setup_data = {
629 .rpc_client = rpcb_clnt,
630 .rpc_message = &msg,
631 .callback_ops = &rpcb_getport_ops,
632 .callback_data = map,
633 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
634 };
635
636 return rpc_run_task(&task_setup_data);
637 }
638
639 /*
640 * In the case where rpc clients have been cloned, we want to make
641 * sure that we use the program number/version etc of the actual
642 * owner of the xprt. To do so, we walk back up the tree of parents
643 * to find whoever created the transport and/or whoever has the
644 * autobind flag set.
645 */
rpcb_find_transport_owner(struct rpc_clnt * clnt)646 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
647 {
648 struct rpc_clnt *parent = clnt->cl_parent;
649 struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
650
651 while (parent != clnt) {
652 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
653 break;
654 if (clnt->cl_autobind)
655 break;
656 clnt = parent;
657 parent = parent->cl_parent;
658 }
659 return clnt;
660 }
661
662 /**
663 * rpcb_getport_async - obtain the port for a given RPC service on a given host
664 * @task: task that is waiting for portmapper request
665 *
666 * This one can be called for an ongoing RPC request, and can be used in
667 * an async (rpciod) context.
668 */
rpcb_getport_async(struct rpc_task * task)669 void rpcb_getport_async(struct rpc_task *task)
670 {
671 struct rpc_clnt *clnt;
672 const struct rpc_procinfo *proc;
673 u32 bind_version;
674 struct rpc_xprt *xprt;
675 struct rpc_clnt *rpcb_clnt;
676 struct rpcbind_args *map;
677 struct rpc_task *child;
678 struct sockaddr_storage addr;
679 struct sockaddr *sap = (struct sockaddr *)&addr;
680 size_t salen;
681 int status;
682
683 rcu_read_lock();
684 clnt = rpcb_find_transport_owner(task->tk_client);
685 rcu_read_unlock();
686 xprt = xprt_get(task->tk_xprt);
687
688 /* Put self on the wait queue to ensure we get notified if
689 * some other task is already attempting to bind the port */
690 rpc_sleep_on_timeout(&xprt->binding, task,
691 NULL, jiffies + xprt->bind_timeout);
692
693 if (xprt_test_and_set_binding(xprt)) {
694 xprt_put(xprt);
695 return;
696 }
697
698 /* Someone else may have bound if we slept */
699 if (xprt_bound(xprt)) {
700 status = 0;
701 goto bailout_nofree;
702 }
703
704 /* Parent transport's destination address */
705 salen = rpc_peeraddr(clnt, sap, sizeof(addr));
706
707 /* Don't ever use rpcbind v2 for AF_INET6 requests */
708 switch (sap->sa_family) {
709 case AF_INET:
710 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
711 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
712 break;
713 case AF_INET6:
714 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
715 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
716 break;
717 default:
718 status = -EAFNOSUPPORT;
719 goto bailout_nofree;
720 }
721 if (proc == NULL) {
722 xprt->bind_index = 0;
723 status = -EPFNOSUPPORT;
724 goto bailout_nofree;
725 }
726
727 trace_rpcb_getport(clnt, task, bind_version);
728
729 rpcb_clnt = rpcb_create(xprt->xprt_net,
730 clnt->cl_nodename,
731 xprt->servername, sap, salen,
732 xprt->prot, bind_version,
733 clnt->cl_cred,
734 task->tk_client->cl_timeout);
735 if (IS_ERR(rpcb_clnt)) {
736 status = PTR_ERR(rpcb_clnt);
737 goto bailout_nofree;
738 }
739
740 map = kzalloc(sizeof(struct rpcbind_args), rpc_task_gfp_mask());
741 if (!map) {
742 status = -ENOMEM;
743 goto bailout_release_client;
744 }
745 map->r_prog = clnt->cl_prog;
746 map->r_vers = clnt->cl_vers;
747 map->r_prot = xprt->prot;
748 map->r_port = 0;
749 map->r_xprt = xprt;
750 map->r_status = -EIO;
751
752 switch (bind_version) {
753 case RPCBVERS_4:
754 case RPCBVERS_3:
755 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
756 map->r_addr = rpc_sockaddr2uaddr(sap, rpc_task_gfp_mask());
757 if (!map->r_addr) {
758 status = -ENOMEM;
759 goto bailout_free_args;
760 }
761 map->r_owner = "";
762 break;
763 case RPCBVERS_2:
764 map->r_addr = NULL;
765 break;
766 default:
767 BUG();
768 }
769
770 child = rpcb_call_async(rpcb_clnt, map, proc);
771 rpc_release_client(rpcb_clnt);
772 if (IS_ERR(child)) {
773 /* rpcb_map_release() has freed the arguments */
774 return;
775 }
776
777 xprt->stat.bind_count++;
778 rpc_put_task(child);
779 return;
780
781 bailout_free_args:
782 kfree(map);
783 bailout_release_client:
784 rpc_release_client(rpcb_clnt);
785 bailout_nofree:
786 rpcb_wake_rpcbind_waiters(xprt, status);
787 task->tk_status = status;
788 xprt_put(xprt);
789 }
790 EXPORT_SYMBOL_GPL(rpcb_getport_async);
791
792 /*
793 * Rpcbind child task calls this callback via tk_exit.
794 */
rpcb_getport_done(struct rpc_task * child,void * data)795 static void rpcb_getport_done(struct rpc_task *child, void *data)
796 {
797 struct rpcbind_args *map = data;
798 struct rpc_xprt *xprt = map->r_xprt;
799
800 map->r_status = child->tk_status;
801
802 /* Garbage reply: retry with a lesser rpcbind version */
803 if (map->r_status == -EIO)
804 map->r_status = -EPROTONOSUPPORT;
805
806 /* rpcbind server doesn't support this rpcbind protocol version */
807 if (map->r_status == -EPROTONOSUPPORT)
808 xprt->bind_index++;
809
810 if (map->r_status < 0) {
811 /* rpcbind server not available on remote host? */
812 map->r_port = 0;
813
814 } else if (map->r_port == 0) {
815 /* Requested RPC service wasn't registered on remote host */
816 map->r_status = -EACCES;
817 } else {
818 /* Succeeded */
819 map->r_status = 0;
820 }
821
822 trace_rpcb_setport(child, map->r_status, map->r_port);
823 if (map->r_port) {
824 xprt->ops->set_port(xprt, map->r_port);
825 xprt_set_bound(xprt);
826 }
827 }
828
829 /*
830 * XDR functions for rpcbind
831 */
832
rpcb_enc_mapping(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)833 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
834 const void *data)
835 {
836 const struct rpcbind_args *rpcb = data;
837 __be32 *p;
838
839 p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
840 *p++ = cpu_to_be32(rpcb->r_prog);
841 *p++ = cpu_to_be32(rpcb->r_vers);
842 *p++ = cpu_to_be32(rpcb->r_prot);
843 *p = cpu_to_be32(rpcb->r_port);
844 }
845
rpcb_dec_getport(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)846 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
847 void *data)
848 {
849 struct rpcbind_args *rpcb = data;
850 unsigned long port;
851 __be32 *p;
852
853 rpcb->r_port = 0;
854
855 p = xdr_inline_decode(xdr, 4);
856 if (unlikely(p == NULL))
857 return -EIO;
858
859 port = be32_to_cpup(p);
860 if (unlikely(port > USHRT_MAX))
861 return -EIO;
862
863 rpcb->r_port = port;
864 return 0;
865 }
866
rpcb_dec_set(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)867 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
868 void *data)
869 {
870 unsigned int *boolp = data;
871 __be32 *p;
872
873 p = xdr_inline_decode(xdr, 4);
874 if (unlikely(p == NULL))
875 return -EIO;
876
877 *boolp = 0;
878 if (*p != xdr_zero)
879 *boolp = 1;
880 return 0;
881 }
882
encode_rpcb_string(struct xdr_stream * xdr,const char * string,const u32 maxstrlen)883 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
884 const u32 maxstrlen)
885 {
886 __be32 *p;
887 u32 len;
888
889 len = strlen(string);
890 WARN_ON_ONCE(len > maxstrlen);
891 if (len > maxstrlen)
892 /* truncate and hope for the best */
893 len = maxstrlen;
894 p = xdr_reserve_space(xdr, 4 + len);
895 xdr_encode_opaque(p, string, len);
896 }
897
rpcb_enc_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)898 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
899 const void *data)
900 {
901 const struct rpcbind_args *rpcb = data;
902 __be32 *p;
903
904 p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
905 *p++ = cpu_to_be32(rpcb->r_prog);
906 *p = cpu_to_be32(rpcb->r_vers);
907
908 encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
909 encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
910 encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
911 }
912
rpcb_dec_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)913 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
914 void *data)
915 {
916 struct rpcbind_args *rpcb = data;
917 struct sockaddr_storage address;
918 struct sockaddr *sap = (struct sockaddr *)&address;
919 __be32 *p;
920 u32 len;
921
922 rpcb->r_port = 0;
923
924 p = xdr_inline_decode(xdr, 4);
925 if (unlikely(p == NULL))
926 goto out_fail;
927 len = be32_to_cpup(p);
928
929 /*
930 * If the returned universal address is a null string,
931 * the requested RPC service was not registered.
932 */
933 if (len == 0)
934 return 0;
935
936 if (unlikely(len > RPCBIND_MAXUADDRLEN))
937 goto out_fail;
938
939 p = xdr_inline_decode(xdr, len);
940 if (unlikely(p == NULL))
941 goto out_fail;
942
943 if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
944 sap, sizeof(address)) == 0)
945 goto out_fail;
946 rpcb->r_port = rpc_get_port(sap);
947
948 return 0;
949
950 out_fail:
951 return -EIO;
952 }
953
954 /*
955 * Not all rpcbind procedures described in RFC 1833 are implemented
956 * since the Linux kernel RPC code requires only these.
957 */
958
959 static const struct rpc_procinfo rpcb_procedures2[] = {
960 [RPCBPROC_SET] = {
961 .p_proc = RPCBPROC_SET,
962 .p_encode = rpcb_enc_mapping,
963 .p_decode = rpcb_dec_set,
964 .p_arglen = RPCB_mappingargs_sz,
965 .p_replen = RPCB_setres_sz,
966 .p_statidx = RPCBPROC_SET,
967 .p_timer = 0,
968 .p_name = "SET",
969 },
970 [RPCBPROC_UNSET] = {
971 .p_proc = RPCBPROC_UNSET,
972 .p_encode = rpcb_enc_mapping,
973 .p_decode = rpcb_dec_set,
974 .p_arglen = RPCB_mappingargs_sz,
975 .p_replen = RPCB_setres_sz,
976 .p_statidx = RPCBPROC_UNSET,
977 .p_timer = 0,
978 .p_name = "UNSET",
979 },
980 [RPCBPROC_GETPORT] = {
981 .p_proc = RPCBPROC_GETPORT,
982 .p_encode = rpcb_enc_mapping,
983 .p_decode = rpcb_dec_getport,
984 .p_arglen = RPCB_mappingargs_sz,
985 .p_replen = RPCB_getportres_sz,
986 .p_statidx = RPCBPROC_GETPORT,
987 .p_timer = 0,
988 .p_name = "GETPORT",
989 },
990 };
991
992 static const struct rpc_procinfo rpcb_procedures3[] = {
993 [RPCBPROC_SET] = {
994 .p_proc = RPCBPROC_SET,
995 .p_encode = rpcb_enc_getaddr,
996 .p_decode = rpcb_dec_set,
997 .p_arglen = RPCB_getaddrargs_sz,
998 .p_replen = RPCB_setres_sz,
999 .p_statidx = RPCBPROC_SET,
1000 .p_timer = 0,
1001 .p_name = "SET",
1002 },
1003 [RPCBPROC_UNSET] = {
1004 .p_proc = RPCBPROC_UNSET,
1005 .p_encode = rpcb_enc_getaddr,
1006 .p_decode = rpcb_dec_set,
1007 .p_arglen = RPCB_getaddrargs_sz,
1008 .p_replen = RPCB_setres_sz,
1009 .p_statidx = RPCBPROC_UNSET,
1010 .p_timer = 0,
1011 .p_name = "UNSET",
1012 },
1013 [RPCBPROC_GETADDR] = {
1014 .p_proc = RPCBPROC_GETADDR,
1015 .p_encode = rpcb_enc_getaddr,
1016 .p_decode = rpcb_dec_getaddr,
1017 .p_arglen = RPCB_getaddrargs_sz,
1018 .p_replen = RPCB_getaddrres_sz,
1019 .p_statidx = RPCBPROC_GETADDR,
1020 .p_timer = 0,
1021 .p_name = "GETADDR",
1022 },
1023 };
1024
1025 static const struct rpc_procinfo rpcb_procedures4[] = {
1026 [RPCBPROC_SET] = {
1027 .p_proc = RPCBPROC_SET,
1028 .p_encode = rpcb_enc_getaddr,
1029 .p_decode = rpcb_dec_set,
1030 .p_arglen = RPCB_getaddrargs_sz,
1031 .p_replen = RPCB_setres_sz,
1032 .p_statidx = RPCBPROC_SET,
1033 .p_timer = 0,
1034 .p_name = "SET",
1035 },
1036 [RPCBPROC_UNSET] = {
1037 .p_proc = RPCBPROC_UNSET,
1038 .p_encode = rpcb_enc_getaddr,
1039 .p_decode = rpcb_dec_set,
1040 .p_arglen = RPCB_getaddrargs_sz,
1041 .p_replen = RPCB_setres_sz,
1042 .p_statidx = RPCBPROC_UNSET,
1043 .p_timer = 0,
1044 .p_name = "UNSET",
1045 },
1046 [RPCBPROC_GETADDR] = {
1047 .p_proc = RPCBPROC_GETADDR,
1048 .p_encode = rpcb_enc_getaddr,
1049 .p_decode = rpcb_dec_getaddr,
1050 .p_arglen = RPCB_getaddrargs_sz,
1051 .p_replen = RPCB_getaddrres_sz,
1052 .p_statidx = RPCBPROC_GETADDR,
1053 .p_timer = 0,
1054 .p_name = "GETADDR",
1055 },
1056 };
1057
1058 static const struct rpcb_info rpcb_next_version[] = {
1059 {
1060 .rpc_vers = RPCBVERS_2,
1061 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT],
1062 },
1063 {
1064 .rpc_proc = NULL,
1065 },
1066 };
1067
1068 static const struct rpcb_info rpcb_next_version6[] = {
1069 {
1070 .rpc_vers = RPCBVERS_4,
1071 .rpc_proc = &rpcb_procedures4[RPCBPROC_GETADDR],
1072 },
1073 {
1074 .rpc_vers = RPCBVERS_3,
1075 .rpc_proc = &rpcb_procedures3[RPCBPROC_GETADDR],
1076 },
1077 {
1078 .rpc_proc = NULL,
1079 },
1080 };
1081
1082 static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)];
1083 static const struct rpc_version rpcb_version2 = {
1084 .number = RPCBVERS_2,
1085 .nrprocs = ARRAY_SIZE(rpcb_procedures2),
1086 .procs = rpcb_procedures2,
1087 .counts = rpcb_version2_counts,
1088 };
1089
1090 static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)];
1091 static const struct rpc_version rpcb_version3 = {
1092 .number = RPCBVERS_3,
1093 .nrprocs = ARRAY_SIZE(rpcb_procedures3),
1094 .procs = rpcb_procedures3,
1095 .counts = rpcb_version3_counts,
1096 };
1097
1098 static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)];
1099 static const struct rpc_version rpcb_version4 = {
1100 .number = RPCBVERS_4,
1101 .nrprocs = ARRAY_SIZE(rpcb_procedures4),
1102 .procs = rpcb_procedures4,
1103 .counts = rpcb_version4_counts,
1104 };
1105
1106 static const struct rpc_version *rpcb_version[] = {
1107 NULL,
1108 NULL,
1109 &rpcb_version2,
1110 &rpcb_version3,
1111 &rpcb_version4
1112 };
1113
1114 static struct rpc_stat rpcb_stats;
1115
1116 static const struct rpc_program rpcb_program = {
1117 .name = "rpcbind",
1118 .number = RPCBIND_PROGRAM,
1119 .nrvers = ARRAY_SIZE(rpcb_version),
1120 .version = rpcb_version,
1121 .stats = &rpcb_stats,
1122 };
1123