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 <net/ipv6.h>
27
28 #include <linux/sunrpc/clnt.h>
29 #include <linux/sunrpc/addr.h>
30 #include <linux/sunrpc/sched.h>
31 #include <linux/sunrpc/xprtsock.h>
32
33 #include "netns.h"
34
35 #if IS_ENABLED(CONFIG_SUNRPC_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 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 dprintk("RPC: created new rpcb local clients (rpcb_local_clnt: "
219 "%p, rpcb_local_clnt4: %p) for net %x%s\n",
220 sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
221 net->ns.inum, (net == &init_net) ? " (init_net)" : "");
222 }
223
224 /*
225 * Returns zero on success, otherwise a negative errno value
226 * is returned.
227 */
rpcb_create_local_unix(struct net * net)228 static int rpcb_create_local_unix(struct net *net)
229 {
230 static const struct sockaddr_un rpcb_localaddr_rpcbind = {
231 .sun_family = AF_LOCAL,
232 .sun_path = RPCBIND_SOCK_PATHNAME,
233 };
234 struct rpc_create_args args = {
235 .net = net,
236 .protocol = XPRT_TRANSPORT_LOCAL,
237 .address = (struct sockaddr *)&rpcb_localaddr_rpcbind,
238 .addrsize = sizeof(rpcb_localaddr_rpcbind),
239 .servername = "localhost",
240 .program = &rpcb_program,
241 .version = RPCBVERS_2,
242 .authflavor = RPC_AUTH_NULL,
243 /*
244 * We turn off the idle timeout to prevent the kernel
245 * from automatically disconnecting the socket.
246 * Otherwise, we'd have to cache the mount namespace
247 * of the caller and somehow pass that to the socket
248 * reconnect code.
249 */
250 .flags = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
251 };
252 struct rpc_clnt *clnt, *clnt4;
253 int result = 0;
254
255 /*
256 * Because we requested an RPC PING at transport creation time,
257 * this works only if the user space portmapper is rpcbind, and
258 * it's listening on AF_LOCAL on the named socket.
259 */
260 clnt = rpc_create(&args);
261 if (IS_ERR(clnt)) {
262 dprintk("RPC: failed to create AF_LOCAL rpcbind "
263 "client (errno %ld).\n", PTR_ERR(clnt));
264 result = PTR_ERR(clnt);
265 goto out;
266 }
267
268 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
269 if (IS_ERR(clnt4)) {
270 dprintk("RPC: failed to bind second program to "
271 "rpcbind v4 client (errno %ld).\n",
272 PTR_ERR(clnt4));
273 clnt4 = NULL;
274 }
275
276 rpcb_set_local(net, clnt, clnt4, true);
277
278 out:
279 return result;
280 }
281
282 /*
283 * Returns zero on success, otherwise a negative errno value
284 * is returned.
285 */
rpcb_create_local_net(struct net * net)286 static int rpcb_create_local_net(struct net *net)
287 {
288 static const struct sockaddr_in rpcb_inaddr_loopback = {
289 .sin_family = AF_INET,
290 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
291 .sin_port = htons(RPCBIND_PORT),
292 };
293 struct rpc_create_args args = {
294 .net = net,
295 .protocol = XPRT_TRANSPORT_TCP,
296 .address = (struct sockaddr *)&rpcb_inaddr_loopback,
297 .addrsize = sizeof(rpcb_inaddr_loopback),
298 .servername = "localhost",
299 .program = &rpcb_program,
300 .version = RPCBVERS_2,
301 .authflavor = RPC_AUTH_UNIX,
302 .flags = RPC_CLNT_CREATE_NOPING,
303 };
304 struct rpc_clnt *clnt, *clnt4;
305 int result = 0;
306
307 clnt = rpc_create(&args);
308 if (IS_ERR(clnt)) {
309 dprintk("RPC: failed to create local rpcbind "
310 "client (errno %ld).\n", PTR_ERR(clnt));
311 result = PTR_ERR(clnt);
312 goto out;
313 }
314
315 /*
316 * This results in an RPC ping. On systems running portmapper,
317 * the v4 ping will fail. Proceed anyway, but disallow rpcb
318 * v4 upcalls.
319 */
320 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
321 if (IS_ERR(clnt4)) {
322 dprintk("RPC: failed to bind second program to "
323 "rpcbind v4 client (errno %ld).\n",
324 PTR_ERR(clnt4));
325 clnt4 = NULL;
326 }
327
328 rpcb_set_local(net, clnt, clnt4, false);
329
330 out:
331 return result;
332 }
333
334 /*
335 * Returns zero on success, otherwise a negative errno value
336 * is returned.
337 */
rpcb_create_local(struct net * net)338 int rpcb_create_local(struct net *net)
339 {
340 static DEFINE_MUTEX(rpcb_create_local_mutex);
341 int result = 0;
342
343 if (rpcb_get_local(net))
344 return result;
345
346 mutex_lock(&rpcb_create_local_mutex);
347 if (rpcb_get_local(net))
348 goto out;
349
350 if (rpcb_create_local_unix(net) != 0)
351 result = rpcb_create_local_net(net);
352
353 out:
354 mutex_unlock(&rpcb_create_local_mutex);
355 return result;
356 }
357
rpcb_create(struct net * net,const char * nodename,const char * hostname,struct sockaddr * srvaddr,size_t salen,int proto,u32 version)358 static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
359 const char *hostname,
360 struct sockaddr *srvaddr, size_t salen,
361 int proto, u32 version)
362 {
363 struct rpc_create_args args = {
364 .net = net,
365 .protocol = proto,
366 .address = srvaddr,
367 .addrsize = salen,
368 .servername = hostname,
369 .nodename = nodename,
370 .program = &rpcb_program,
371 .version = version,
372 .authflavor = RPC_AUTH_UNIX,
373 .flags = (RPC_CLNT_CREATE_NOPING |
374 RPC_CLNT_CREATE_NONPRIVPORT),
375 };
376
377 switch (srvaddr->sa_family) {
378 case AF_INET:
379 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
380 break;
381 case AF_INET6:
382 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
383 break;
384 default:
385 return ERR_PTR(-EAFNOSUPPORT);
386 }
387
388 return rpc_create(&args);
389 }
390
rpcb_register_call(struct sunrpc_net * sn,struct rpc_clnt * clnt,struct rpc_message * msg,bool is_set)391 static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
392 {
393 int flags = RPC_TASK_NOCONNECT;
394 int error, result = 0;
395
396 if (is_set || !sn->rpcb_is_af_local)
397 flags = RPC_TASK_SOFTCONN;
398 msg->rpc_resp = &result;
399
400 error = rpc_call_sync(clnt, msg, flags);
401 if (error < 0) {
402 dprintk("RPC: failed to contact local rpcbind "
403 "server (errno %d).\n", -error);
404 return error;
405 }
406
407 if (!result)
408 return -EACCES;
409 return 0;
410 }
411
412 /**
413 * rpcb_register - set or unset a port registration with the local rpcbind svc
414 * @net: target network namespace
415 * @prog: RPC program number to bind
416 * @vers: RPC version number to bind
417 * @prot: transport protocol to register
418 * @port: port value to register
419 *
420 * Returns zero if the registration request was dispatched successfully
421 * and the rpcbind daemon returned success. Otherwise, returns an errno
422 * value that reflects the nature of the error (request could not be
423 * dispatched, timed out, or rpcbind returned an error).
424 *
425 * RPC services invoke this function to advertise their contact
426 * information via the system's rpcbind daemon. RPC services
427 * invoke this function once for each [program, version, transport]
428 * tuple they wish to advertise.
429 *
430 * Callers may also unregister RPC services that are no longer
431 * available by setting the passed-in port to zero. This removes
432 * all registered transports for [program, version] from the local
433 * rpcbind database.
434 *
435 * This function uses rpcbind protocol version 2 to contact the
436 * local rpcbind daemon.
437 *
438 * Registration works over both AF_INET and AF_INET6, and services
439 * registered via this function are advertised as available for any
440 * address. If the local rpcbind daemon is listening on AF_INET6,
441 * services registered via this function will be advertised on
442 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
443 * addresses).
444 */
rpcb_register(struct net * net,u32 prog,u32 vers,int prot,unsigned short port)445 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
446 {
447 struct rpcbind_args map = {
448 .r_prog = prog,
449 .r_vers = vers,
450 .r_prot = prot,
451 .r_port = port,
452 };
453 struct rpc_message msg = {
454 .rpc_argp = &map,
455 };
456 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
457 bool is_set = false;
458
459 dprintk("RPC: %sregistering (%u, %u, %d, %u) with local "
460 "rpcbind\n", (port ? "" : "un"),
461 prog, vers, prot, port);
462
463 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
464 if (port != 0) {
465 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
466 is_set = true;
467 }
468
469 return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
470 }
471
472 /*
473 * Fill in AF_INET family-specific arguments to register
474 */
rpcb_register_inet4(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)475 static int rpcb_register_inet4(struct sunrpc_net *sn,
476 const struct sockaddr *sap,
477 struct rpc_message *msg)
478 {
479 const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
480 struct rpcbind_args *map = msg->rpc_argp;
481 unsigned short port = ntohs(sin->sin_port);
482 bool is_set = false;
483 int result;
484
485 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
486
487 dprintk("RPC: %sregistering [%u, %u, %s, '%s'] with "
488 "local rpcbind\n", (port ? "" : "un"),
489 map->r_prog, map->r_vers,
490 map->r_addr, map->r_netid);
491
492 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
493 if (port != 0) {
494 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
495 is_set = true;
496 }
497
498 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
499 kfree(map->r_addr);
500 return result;
501 }
502
503 /*
504 * Fill in AF_INET6 family-specific arguments to register
505 */
rpcb_register_inet6(struct sunrpc_net * sn,const struct sockaddr * sap,struct rpc_message * msg)506 static int rpcb_register_inet6(struct sunrpc_net *sn,
507 const struct sockaddr *sap,
508 struct rpc_message *msg)
509 {
510 const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
511 struct rpcbind_args *map = msg->rpc_argp;
512 unsigned short port = ntohs(sin6->sin6_port);
513 bool is_set = false;
514 int result;
515
516 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
517
518 dprintk("RPC: %sregistering [%u, %u, %s, '%s'] with "
519 "local rpcbind\n", (port ? "" : "un"),
520 map->r_prog, map->r_vers,
521 map->r_addr, map->r_netid);
522
523 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
524 if (port != 0) {
525 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
526 is_set = true;
527 }
528
529 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
530 kfree(map->r_addr);
531 return result;
532 }
533
rpcb_unregister_all_protofamilies(struct sunrpc_net * sn,struct rpc_message * msg)534 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
535 struct rpc_message *msg)
536 {
537 struct rpcbind_args *map = msg->rpc_argp;
538
539 dprintk("RPC: unregistering [%u, %u, '%s'] with "
540 "local rpcbind\n",
541 map->r_prog, map->r_vers, map->r_netid);
542
543 map->r_addr = "";
544 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
545
546 return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
547 }
548
549 /**
550 * rpcb_v4_register - set or unset a port registration with the local rpcbind
551 * @net: target network namespace
552 * @program: RPC program number of service to (un)register
553 * @version: RPC version number of service to (un)register
554 * @address: address family, IP address, and port to (un)register
555 * @netid: netid of transport protocol to (un)register
556 *
557 * Returns zero if the registration request was dispatched successfully
558 * and the rpcbind daemon returned success. Otherwise, returns an errno
559 * value that reflects the nature of the error (request could not be
560 * dispatched, timed out, or rpcbind returned an error).
561 *
562 * RPC services invoke this function to advertise their contact
563 * information via the system's rpcbind daemon. RPC services
564 * invoke this function once for each [program, version, address,
565 * netid] tuple they wish to advertise.
566 *
567 * Callers may also unregister RPC services that are registered at a
568 * specific address by setting the port number in @address to zero.
569 * They may unregister all registered protocol families at once for
570 * a service by passing a NULL @address argument. If @netid is ""
571 * then all netids for [program, version, address] are unregistered.
572 *
573 * This function uses rpcbind protocol version 4 to contact the
574 * local rpcbind daemon. The local rpcbind daemon must support
575 * version 4 of the rpcbind protocol in order for these functions
576 * to register a service successfully.
577 *
578 * Supported netids include "udp" and "tcp" for UDP and TCP over
579 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
580 * respectively.
581 *
582 * The contents of @address determine the address family and the
583 * port to be registered. The usual practice is to pass INADDR_ANY
584 * as the raw address, but specifying a non-zero address is also
585 * supported by this API if the caller wishes to advertise an RPC
586 * service on a specific network interface.
587 *
588 * Note that passing in INADDR_ANY does not create the same service
589 * registration as IN6ADDR_ANY. The former advertises an RPC
590 * service on any IPv4 address, but not on IPv6. The latter
591 * advertises the service on all IPv4 and IPv6 addresses.
592 */
rpcb_v4_register(struct net * net,const u32 program,const u32 version,const struct sockaddr * address,const char * netid)593 int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
594 const struct sockaddr *address, const char *netid)
595 {
596 struct rpcbind_args map = {
597 .r_prog = program,
598 .r_vers = version,
599 .r_netid = netid,
600 .r_owner = RPCB_OWNER_STRING,
601 };
602 struct rpc_message msg = {
603 .rpc_argp = &map,
604 };
605 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
606
607 if (sn->rpcb_local_clnt4 == NULL)
608 return -EPROTONOSUPPORT;
609
610 if (address == NULL)
611 return rpcb_unregister_all_protofamilies(sn, &msg);
612
613 switch (address->sa_family) {
614 case AF_INET:
615 return rpcb_register_inet4(sn, address, &msg);
616 case AF_INET6:
617 return rpcb_register_inet6(sn, address, &msg);
618 }
619
620 return -EAFNOSUPPORT;
621 }
622
rpcb_call_async(struct rpc_clnt * rpcb_clnt,struct rpcbind_args * map,const struct rpc_procinfo * proc)623 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt,
624 struct rpcbind_args *map, const struct rpc_procinfo *proc)
625 {
626 struct rpc_message msg = {
627 .rpc_proc = proc,
628 .rpc_argp = map,
629 .rpc_resp = map,
630 };
631 struct rpc_task_setup task_setup_data = {
632 .rpc_client = rpcb_clnt,
633 .rpc_message = &msg,
634 .callback_ops = &rpcb_getport_ops,
635 .callback_data = map,
636 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
637 };
638
639 return rpc_run_task(&task_setup_data);
640 }
641
642 /*
643 * In the case where rpc clients have been cloned, we want to make
644 * sure that we use the program number/version etc of the actual
645 * owner of the xprt. To do so, we walk back up the tree of parents
646 * to find whoever created the transport and/or whoever has the
647 * autobind flag set.
648 */
rpcb_find_transport_owner(struct rpc_clnt * clnt)649 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
650 {
651 struct rpc_clnt *parent = clnt->cl_parent;
652 struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
653
654 while (parent != clnt) {
655 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
656 break;
657 if (clnt->cl_autobind)
658 break;
659 clnt = parent;
660 parent = parent->cl_parent;
661 }
662 return clnt;
663 }
664
665 /**
666 * rpcb_getport_async - obtain the port for a given RPC service on a given host
667 * @task: task that is waiting for portmapper request
668 *
669 * This one can be called for an ongoing RPC request, and can be used in
670 * an async (rpciod) context.
671 */
rpcb_getport_async(struct rpc_task * task)672 void rpcb_getport_async(struct rpc_task *task)
673 {
674 struct rpc_clnt *clnt;
675 const struct rpc_procinfo *proc;
676 u32 bind_version;
677 struct rpc_xprt *xprt;
678 struct rpc_clnt *rpcb_clnt;
679 struct rpcbind_args *map;
680 struct rpc_task *child;
681 struct sockaddr_storage addr;
682 struct sockaddr *sap = (struct sockaddr *)&addr;
683 size_t salen;
684 int status;
685
686 rcu_read_lock();
687 clnt = rpcb_find_transport_owner(task->tk_client);
688 rcu_read_unlock();
689 xprt = xprt_get(task->tk_xprt);
690
691 dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
692 task->tk_pid, __func__,
693 xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
694
695 /* Put self on the wait queue to ensure we get notified if
696 * some other task is already attempting to bind the port */
697 rpc_sleep_on(&xprt->binding, task, NULL);
698
699 if (xprt_test_and_set_binding(xprt)) {
700 dprintk("RPC: %5u %s: waiting for another binder\n",
701 task->tk_pid, __func__);
702 xprt_put(xprt);
703 return;
704 }
705
706 /* Someone else may have bound if we slept */
707 if (xprt_bound(xprt)) {
708 status = 0;
709 dprintk("RPC: %5u %s: already bound\n",
710 task->tk_pid, __func__);
711 goto bailout_nofree;
712 }
713
714 /* Parent transport's destination address */
715 salen = rpc_peeraddr(clnt, sap, sizeof(addr));
716
717 /* Don't ever use rpcbind v2 for AF_INET6 requests */
718 switch (sap->sa_family) {
719 case AF_INET:
720 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
721 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
722 break;
723 case AF_INET6:
724 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
725 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
726 break;
727 default:
728 status = -EAFNOSUPPORT;
729 dprintk("RPC: %5u %s: bad address family\n",
730 task->tk_pid, __func__);
731 goto bailout_nofree;
732 }
733 if (proc == NULL) {
734 xprt->bind_index = 0;
735 status = -EPFNOSUPPORT;
736 dprintk("RPC: %5u %s: no more getport versions available\n",
737 task->tk_pid, __func__);
738 goto bailout_nofree;
739 }
740
741 dprintk("RPC: %5u %s: trying rpcbind version %u\n",
742 task->tk_pid, __func__, bind_version);
743
744 rpcb_clnt = rpcb_create(xprt->xprt_net,
745 clnt->cl_nodename,
746 xprt->servername, sap, salen,
747 xprt->prot, bind_version);
748 if (IS_ERR(rpcb_clnt)) {
749 status = PTR_ERR(rpcb_clnt);
750 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
751 task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
752 goto bailout_nofree;
753 }
754
755 map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
756 if (!map) {
757 status = -ENOMEM;
758 dprintk("RPC: %5u %s: no memory available\n",
759 task->tk_pid, __func__);
760 goto bailout_release_client;
761 }
762 map->r_prog = clnt->cl_prog;
763 map->r_vers = clnt->cl_vers;
764 map->r_prot = xprt->prot;
765 map->r_port = 0;
766 map->r_xprt = xprt;
767 map->r_status = -EIO;
768
769 switch (bind_version) {
770 case RPCBVERS_4:
771 case RPCBVERS_3:
772 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
773 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
774 map->r_owner = "";
775 break;
776 case RPCBVERS_2:
777 map->r_addr = NULL;
778 break;
779 default:
780 BUG();
781 }
782
783 child = rpcb_call_async(rpcb_clnt, map, proc);
784 rpc_release_client(rpcb_clnt);
785 if (IS_ERR(child)) {
786 /* rpcb_map_release() has freed the arguments */
787 dprintk("RPC: %5u %s: rpc_run_task failed\n",
788 task->tk_pid, __func__);
789 return;
790 }
791
792 xprt->stat.bind_count++;
793 rpc_put_task(child);
794 return;
795
796 bailout_release_client:
797 rpc_release_client(rpcb_clnt);
798 bailout_nofree:
799 rpcb_wake_rpcbind_waiters(xprt, status);
800 task->tk_status = status;
801 xprt_put(xprt);
802 }
803 EXPORT_SYMBOL_GPL(rpcb_getport_async);
804
805 /*
806 * Rpcbind child task calls this callback via tk_exit.
807 */
rpcb_getport_done(struct rpc_task * child,void * data)808 static void rpcb_getport_done(struct rpc_task *child, void *data)
809 {
810 struct rpcbind_args *map = data;
811 struct rpc_xprt *xprt = map->r_xprt;
812 int status = child->tk_status;
813
814 /* Garbage reply: retry with a lesser rpcbind version */
815 if (status == -EIO)
816 status = -EPROTONOSUPPORT;
817
818 /* rpcbind server doesn't support this rpcbind protocol version */
819 if (status == -EPROTONOSUPPORT)
820 xprt->bind_index++;
821
822 if (status < 0) {
823 /* rpcbind server not available on remote host? */
824 xprt->ops->set_port(xprt, 0);
825 } else if (map->r_port == 0) {
826 /* Requested RPC service wasn't registered on remote host */
827 xprt->ops->set_port(xprt, 0);
828 status = -EACCES;
829 } else {
830 /* Succeeded */
831 xprt->ops->set_port(xprt, map->r_port);
832 xprt_set_bound(xprt);
833 status = 0;
834 }
835
836 dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
837 child->tk_pid, status, map->r_port);
838
839 map->r_status = status;
840 }
841
842 /*
843 * XDR functions for rpcbind
844 */
845
rpcb_enc_mapping(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)846 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
847 const void *data)
848 {
849 const struct rpcbind_args *rpcb = data;
850 __be32 *p;
851
852 dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
853 req->rq_task->tk_pid,
854 req->rq_task->tk_msg.rpc_proc->p_name,
855 rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
856
857 p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
858 *p++ = cpu_to_be32(rpcb->r_prog);
859 *p++ = cpu_to_be32(rpcb->r_vers);
860 *p++ = cpu_to_be32(rpcb->r_prot);
861 *p = cpu_to_be32(rpcb->r_port);
862 }
863
rpcb_dec_getport(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)864 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
865 void *data)
866 {
867 struct rpcbind_args *rpcb = data;
868 unsigned long port;
869 __be32 *p;
870
871 rpcb->r_port = 0;
872
873 p = xdr_inline_decode(xdr, 4);
874 if (unlikely(p == NULL))
875 return -EIO;
876
877 port = be32_to_cpup(p);
878 dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
879 req->rq_task->tk_msg.rpc_proc->p_name, port);
880 if (unlikely(port > USHRT_MAX))
881 return -EIO;
882
883 rpcb->r_port = port;
884 return 0;
885 }
886
rpcb_dec_set(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)887 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
888 void *data)
889 {
890 unsigned int *boolp = data;
891 __be32 *p;
892
893 p = xdr_inline_decode(xdr, 4);
894 if (unlikely(p == NULL))
895 return -EIO;
896
897 *boolp = 0;
898 if (*p != xdr_zero)
899 *boolp = 1;
900
901 dprintk("RPC: %5u RPCB_%s call %s\n",
902 req->rq_task->tk_pid,
903 req->rq_task->tk_msg.rpc_proc->p_name,
904 (*boolp ? "succeeded" : "failed"));
905 return 0;
906 }
907
encode_rpcb_string(struct xdr_stream * xdr,const char * string,const u32 maxstrlen)908 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
909 const u32 maxstrlen)
910 {
911 __be32 *p;
912 u32 len;
913
914 len = strlen(string);
915 WARN_ON_ONCE(len > maxstrlen);
916 if (len > maxstrlen)
917 /* truncate and hope for the best */
918 len = maxstrlen;
919 p = xdr_reserve_space(xdr, 4 + len);
920 xdr_encode_opaque(p, string, len);
921 }
922
rpcb_enc_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)923 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
924 const void *data)
925 {
926 const struct rpcbind_args *rpcb = data;
927 __be32 *p;
928
929 dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
930 req->rq_task->tk_pid,
931 req->rq_task->tk_msg.rpc_proc->p_name,
932 rpcb->r_prog, rpcb->r_vers,
933 rpcb->r_netid, rpcb->r_addr);
934
935 p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
936 *p++ = cpu_to_be32(rpcb->r_prog);
937 *p = cpu_to_be32(rpcb->r_vers);
938
939 encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
940 encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
941 encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
942 }
943
rpcb_dec_getaddr(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)944 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
945 void *data)
946 {
947 struct rpcbind_args *rpcb = data;
948 struct sockaddr_storage address;
949 struct sockaddr *sap = (struct sockaddr *)&address;
950 __be32 *p;
951 u32 len;
952
953 rpcb->r_port = 0;
954
955 p = xdr_inline_decode(xdr, 4);
956 if (unlikely(p == NULL))
957 goto out_fail;
958 len = be32_to_cpup(p);
959
960 /*
961 * If the returned universal address is a null string,
962 * the requested RPC service was not registered.
963 */
964 if (len == 0) {
965 dprintk("RPC: %5u RPCB reply: program not registered\n",
966 req->rq_task->tk_pid);
967 return 0;
968 }
969
970 if (unlikely(len > RPCBIND_MAXUADDRLEN))
971 goto out_fail;
972
973 p = xdr_inline_decode(xdr, len);
974 if (unlikely(p == NULL))
975 goto out_fail;
976 dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
977 req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
978
979 if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
980 sap, sizeof(address)) == 0)
981 goto out_fail;
982 rpcb->r_port = rpc_get_port(sap);
983
984 return 0;
985
986 out_fail:
987 dprintk("RPC: %5u malformed RPCB_%s reply\n",
988 req->rq_task->tk_pid,
989 req->rq_task->tk_msg.rpc_proc->p_name);
990 return -EIO;
991 }
992
993 /*
994 * Not all rpcbind procedures described in RFC 1833 are implemented
995 * since the Linux kernel RPC code requires only these.
996 */
997
998 static const struct rpc_procinfo rpcb_procedures2[] = {
999 [RPCBPROC_SET] = {
1000 .p_proc = RPCBPROC_SET,
1001 .p_encode = rpcb_enc_mapping,
1002 .p_decode = rpcb_dec_set,
1003 .p_arglen = RPCB_mappingargs_sz,
1004 .p_replen = RPCB_setres_sz,
1005 .p_statidx = RPCBPROC_SET,
1006 .p_timer = 0,
1007 .p_name = "SET",
1008 },
1009 [RPCBPROC_UNSET] = {
1010 .p_proc = RPCBPROC_UNSET,
1011 .p_encode = rpcb_enc_mapping,
1012 .p_decode = rpcb_dec_set,
1013 .p_arglen = RPCB_mappingargs_sz,
1014 .p_replen = RPCB_setres_sz,
1015 .p_statidx = RPCBPROC_UNSET,
1016 .p_timer = 0,
1017 .p_name = "UNSET",
1018 },
1019 [RPCBPROC_GETPORT] = {
1020 .p_proc = RPCBPROC_GETPORT,
1021 .p_encode = rpcb_enc_mapping,
1022 .p_decode = rpcb_dec_getport,
1023 .p_arglen = RPCB_mappingargs_sz,
1024 .p_replen = RPCB_getportres_sz,
1025 .p_statidx = RPCBPROC_GETPORT,
1026 .p_timer = 0,
1027 .p_name = "GETPORT",
1028 },
1029 };
1030
1031 static const struct rpc_procinfo rpcb_procedures3[] = {
1032 [RPCBPROC_SET] = {
1033 .p_proc = RPCBPROC_SET,
1034 .p_encode = rpcb_enc_getaddr,
1035 .p_decode = rpcb_dec_set,
1036 .p_arglen = RPCB_getaddrargs_sz,
1037 .p_replen = RPCB_setres_sz,
1038 .p_statidx = RPCBPROC_SET,
1039 .p_timer = 0,
1040 .p_name = "SET",
1041 },
1042 [RPCBPROC_UNSET] = {
1043 .p_proc = RPCBPROC_UNSET,
1044 .p_encode = rpcb_enc_getaddr,
1045 .p_decode = rpcb_dec_set,
1046 .p_arglen = RPCB_getaddrargs_sz,
1047 .p_replen = RPCB_setres_sz,
1048 .p_statidx = RPCBPROC_UNSET,
1049 .p_timer = 0,
1050 .p_name = "UNSET",
1051 },
1052 [RPCBPROC_GETADDR] = {
1053 .p_proc = RPCBPROC_GETADDR,
1054 .p_encode = rpcb_enc_getaddr,
1055 .p_decode = rpcb_dec_getaddr,
1056 .p_arglen = RPCB_getaddrargs_sz,
1057 .p_replen = RPCB_getaddrres_sz,
1058 .p_statidx = RPCBPROC_GETADDR,
1059 .p_timer = 0,
1060 .p_name = "GETADDR",
1061 },
1062 };
1063
1064 static const struct rpc_procinfo rpcb_procedures4[] = {
1065 [RPCBPROC_SET] = {
1066 .p_proc = RPCBPROC_SET,
1067 .p_encode = rpcb_enc_getaddr,
1068 .p_decode = rpcb_dec_set,
1069 .p_arglen = RPCB_getaddrargs_sz,
1070 .p_replen = RPCB_setres_sz,
1071 .p_statidx = RPCBPROC_SET,
1072 .p_timer = 0,
1073 .p_name = "SET",
1074 },
1075 [RPCBPROC_UNSET] = {
1076 .p_proc = RPCBPROC_UNSET,
1077 .p_encode = rpcb_enc_getaddr,
1078 .p_decode = rpcb_dec_set,
1079 .p_arglen = RPCB_getaddrargs_sz,
1080 .p_replen = RPCB_setres_sz,
1081 .p_statidx = RPCBPROC_UNSET,
1082 .p_timer = 0,
1083 .p_name = "UNSET",
1084 },
1085 [RPCBPROC_GETADDR] = {
1086 .p_proc = RPCBPROC_GETADDR,
1087 .p_encode = rpcb_enc_getaddr,
1088 .p_decode = rpcb_dec_getaddr,
1089 .p_arglen = RPCB_getaddrargs_sz,
1090 .p_replen = RPCB_getaddrres_sz,
1091 .p_statidx = RPCBPROC_GETADDR,
1092 .p_timer = 0,
1093 .p_name = "GETADDR",
1094 },
1095 };
1096
1097 static const struct rpcb_info rpcb_next_version[] = {
1098 {
1099 .rpc_vers = RPCBVERS_2,
1100 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT],
1101 },
1102 {
1103 .rpc_proc = NULL,
1104 },
1105 };
1106
1107 static const struct rpcb_info rpcb_next_version6[] = {
1108 {
1109 .rpc_vers = RPCBVERS_4,
1110 .rpc_proc = &rpcb_procedures4[RPCBPROC_GETADDR],
1111 },
1112 {
1113 .rpc_vers = RPCBVERS_3,
1114 .rpc_proc = &rpcb_procedures3[RPCBPROC_GETADDR],
1115 },
1116 {
1117 .rpc_proc = NULL,
1118 },
1119 };
1120
1121 static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)];
1122 static const struct rpc_version rpcb_version2 = {
1123 .number = RPCBVERS_2,
1124 .nrprocs = ARRAY_SIZE(rpcb_procedures2),
1125 .procs = rpcb_procedures2,
1126 .counts = rpcb_version2_counts,
1127 };
1128
1129 static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)];
1130 static const struct rpc_version rpcb_version3 = {
1131 .number = RPCBVERS_3,
1132 .nrprocs = ARRAY_SIZE(rpcb_procedures3),
1133 .procs = rpcb_procedures3,
1134 .counts = rpcb_version3_counts,
1135 };
1136
1137 static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)];
1138 static const struct rpc_version rpcb_version4 = {
1139 .number = RPCBVERS_4,
1140 .nrprocs = ARRAY_SIZE(rpcb_procedures4),
1141 .procs = rpcb_procedures4,
1142 .counts = rpcb_version4_counts,
1143 };
1144
1145 static const struct rpc_version *rpcb_version[] = {
1146 NULL,
1147 NULL,
1148 &rpcb_version2,
1149 &rpcb_version3,
1150 &rpcb_version4
1151 };
1152
1153 static struct rpc_stat rpcb_stats;
1154
1155 static const struct rpc_program rpcb_program = {
1156 .name = "rpcbind",
1157 .number = RPCBIND_PROGRAM,
1158 .nrvers = ARRAY_SIZE(rpcb_version),
1159 .version = rpcb_version,
1160 .stats = &rpcb_stats,
1161 };
1162
