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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/kernel.h>
20 #include <linux/errno.h>
21
22 #include <linux/sunrpc/clnt.h>
23 #include <linux/sunrpc/sched.h>
24
25 #ifdef RPC_DEBUG
26 # define RPCDBG_FACILITY RPCDBG_BIND
27 #endif
28
29 #define RPCBIND_PROGRAM (100000u)
30 #define RPCBIND_PORT (111u)
31
32 enum {
33 RPCBPROC_NULL,
34 RPCBPROC_SET,
35 RPCBPROC_UNSET,
36 RPCBPROC_GETPORT,
37 RPCBPROC_GETADDR = 3, /* alias for GETPORT */
38 RPCBPROC_DUMP,
39 RPCBPROC_CALLIT,
40 RPCBPROC_BCAST = 5, /* alias for CALLIT */
41 RPCBPROC_GETTIME,
42 RPCBPROC_UADDR2TADDR,
43 RPCBPROC_TADDR2UADDR,
44 RPCBPROC_GETVERSADDR,
45 RPCBPROC_INDIRECT,
46 RPCBPROC_GETADDRLIST,
47 RPCBPROC_GETSTAT,
48 };
49
50 #define RPCB_HIGHPROC_2 RPCBPROC_CALLIT
51 #define RPCB_HIGHPROC_3 RPCBPROC_TADDR2UADDR
52 #define RPCB_HIGHPROC_4 RPCBPROC_GETSTAT
53
54 /*
55 * r_addr
56 *
57 * Quoting RFC 3530, section 2.2:
58 *
59 * For TCP over IPv4 and for UDP over IPv4, the format of r_addr is the
60 * US-ASCII string:
61 *
62 * h1.h2.h3.h4.p1.p2
63 *
64 * The prefix, "h1.h2.h3.h4", is the standard textual form for
65 * representing an IPv4 address, which is always four octets long.
66 * Assuming big-endian ordering, h1, h2, h3, and h4, are respectively,
67 * the first through fourth octets each converted to ASCII-decimal.
68 * Assuming big-endian ordering, p1 and p2 are, respectively, the first
69 * and second octets each converted to ASCII-decimal. For example, if a
70 * host, in big-endian order, has an address of 0x0A010307 and there is
71 * a service listening on, in big endian order, port 0x020F (decimal
72 * 527), then the complete universal address is "10.1.3.7.2.15".
73 *
74 * ...
75 *
76 * For TCP over IPv6 and for UDP over IPv6, the format of r_addr is the
77 * US-ASCII string:
78 *
79 * x1:x2:x3:x4:x5:x6:x7:x8.p1.p2
80 *
81 * The suffix "p1.p2" is the service port, and is computed the same way
82 * as with universal addresses for TCP and UDP over IPv4. The prefix,
83 * "x1:x2:x3:x4:x5:x6:x7:x8", is the standard textual form for
84 * representing an IPv6 address as defined in Section 2.2 of [RFC2373].
85 * Additionally, the two alternative forms specified in Section 2.2 of
86 * [RFC2373] are also acceptable.
87 *
88 * XXX: Currently this implementation does not explicitly convert the
89 * stored address to US-ASCII on non-ASCII systems.
90 */
91 #define RPCB_MAXADDRLEN (128u)
92
93 /*
94 * r_netid
95 *
96 * Quoting RFC 3530, section 2.2:
97 *
98 * For TCP over IPv4 the value of r_netid is the string "tcp". For UDP
99 * over IPv4 the value of r_netid is the string "udp".
100 *
101 * ...
102 *
103 * For TCP over IPv6 the value of r_netid is the string "tcp6". For UDP
104 * over IPv6 the value of r_netid is the string "udp6".
105 */
106 #define RPCB_NETID_UDP "\165\144\160" /* "udp" */
107 #define RPCB_NETID_TCP "\164\143\160" /* "tcp" */
108 #define RPCB_NETID_UDP6 "\165\144\160\066" /* "udp6" */
109 #define RPCB_NETID_TCP6 "\164\143\160\066" /* "tcp6" */
110
111 #define RPCB_MAXNETIDLEN (4u)
112
113 /*
114 * r_owner
115 *
116 * The "owner" is allowed to unset a service in the rpcbind database.
117 * We always use the following (arbitrary) fixed string.
118 */
119 #define RPCB_OWNER_STRING "rpcb"
120 #define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING)
121
122 static void rpcb_getport_done(struct rpc_task *, void *);
123 extern struct rpc_program rpcb_program;
124
125 struct rpcbind_args {
126 struct rpc_xprt * r_xprt;
127
128 u32 r_prog;
129 u32 r_vers;
130 u32 r_prot;
131 unsigned short r_port;
132 char * r_netid;
133 char r_addr[RPCB_MAXADDRLEN];
134 char * r_owner;
135 };
136
137 static struct rpc_procinfo rpcb_procedures2[];
138 static struct rpc_procinfo rpcb_procedures3[];
139
140 static struct rpcb_info {
141 int rpc_vers;
142 struct rpc_procinfo * rpc_proc;
143 } rpcb_next_version[];
144
145 static void rpcb_getport_prepare(struct rpc_task *task, void *calldata)
146 {
147 struct rpcbind_args *map = calldata;
148 struct rpc_xprt *xprt = map->r_xprt;
149 struct rpc_message msg = {
150 .rpc_proc = rpcb_next_version[xprt->bind_index].rpc_proc,
151 .rpc_argp = map,
152 .rpc_resp = &map->r_port,
153 };
154
155 rpc_call_setup(task, &msg, 0);
156 }
157
158 static void rpcb_map_release(void *data)
159 {
160 struct rpcbind_args *map = data;
161
162 xprt_put(map->r_xprt);
163 kfree(map);
164 }
165
166 static const struct rpc_call_ops rpcb_getport_ops = {
167 .rpc_call_prepare = rpcb_getport_prepare,
168 .rpc_call_done = rpcb_getport_done,
169 .rpc_release = rpcb_map_release,
170 };
171
172 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
173 {
174 xprt_clear_binding(xprt);
175 rpc_wake_up_status(&xprt->binding, status);
176 }
177
178 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
179 int proto, int version, int privileged)
180 {
181 struct rpc_create_args args = {
182 .protocol = proto,
183 .address = srvaddr,
184 .addrsize = sizeof(struct sockaddr_in),
185 .servername = hostname,
186 .program = &rpcb_program,
187 .version = version,
188 .authflavor = RPC_AUTH_UNIX,
189 .flags = (RPC_CLNT_CREATE_NOPING |
190 RPC_CLNT_CREATE_INTR),
191 };
192
193 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
194 if (!privileged)
195 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
196 return rpc_create(&args);
197 }
198
199 /**
200 * rpcb_register - set or unset a port registration with the local rpcbind svc
201 * @prog: RPC program number to bind
202 * @vers: RPC version number to bind
203 * @prot: transport protocol to use to make this request
204 * @port: port value to register
205 * @okay: result code
206 *
207 * port == 0 means unregister, port != 0 means register.
208 *
209 * This routine supports only rpcbind version 2.
210 */
211 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
212 {
213 struct sockaddr_in sin = {
214 .sin_family = AF_INET,
215 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
216 };
217 struct rpcbind_args map = {
218 .r_prog = prog,
219 .r_vers = vers,
220 .r_prot = prot,
221 .r_port = port,
222 };
223 struct rpc_message msg = {
224 .rpc_proc = &rpcb_procedures2[port ?
225 RPCBPROC_SET : RPCBPROC_UNSET],
226 .rpc_argp = &map,
227 .rpc_resp = okay,
228 };
229 struct rpc_clnt *rpcb_clnt;
230 int error = 0;
231
232 dprintk("RPC: %sregistering (%u, %u, %d, %u) with local "
233 "rpcbind\n", (port ? "" : "un"),
234 prog, vers, prot, port);
235
236 rpcb_clnt = rpcb_create("localhost", (struct sockaddr *) &sin,
237 IPPROTO_UDP, 2, 1);
238 if (IS_ERR(rpcb_clnt))
239 return PTR_ERR(rpcb_clnt);
240
241 error = rpc_call_sync(rpcb_clnt, &msg, 0);
242
243 rpc_shutdown_client(rpcb_clnt);
244 if (error < 0)
245 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
246 "server (errno %d).\n", -error);
247 dprintk("RPC: registration status %d/%d\n", error, *okay);
248
249 return error;
250 }
251
252 /**
253 * rpcb_getport_sync - obtain the port for an RPC service on a given host
254 * @sin: address of remote peer
255 * @prog: RPC program number to bind
256 * @vers: RPC version number to bind
257 * @prot: transport protocol to use to make this request
258 *
259 * Called from outside the RPC client in a synchronous task context.
260 * Uses default timeout parameters specified by underlying transport.
261 *
262 * XXX: Needs to support IPv6, and rpcbind versions 3 and 4
263 */
264 int rpcb_getport_sync(struct sockaddr_in *sin, __u32 prog,
265 __u32 vers, int prot)
266 {
267 struct rpcbind_args map = {
268 .r_prog = prog,
269 .r_vers = vers,
270 .r_prot = prot,
271 .r_port = 0,
272 };
273 struct rpc_message msg = {
274 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT],
275 .rpc_argp = &map,
276 .rpc_resp = &map.r_port,
277 };
278 struct rpc_clnt *rpcb_clnt;
279 char hostname[40];
280 int status;
281
282 dprintk("RPC: %s(" NIPQUAD_FMT ", %u, %u, %d)\n",
283 __FUNCTION__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
284
285 sprintf(hostname, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
286 rpcb_clnt = rpcb_create(hostname, (struct sockaddr *)sin, prot, 2, 0);
287 if (IS_ERR(rpcb_clnt))
288 return PTR_ERR(rpcb_clnt);
289
290 status = rpc_call_sync(rpcb_clnt, &msg, 0);
291 rpc_shutdown_client(rpcb_clnt);
292
293 if (status >= 0) {
294 if (map.r_port != 0)
295 return map.r_port;
296 status = -EACCES;
297 }
298 return status;
299 }
300 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
301
302 /**
303 * rpcb_getport_async - obtain the port for a given RPC service on a given host
304 * @task: task that is waiting for portmapper request
305 *
306 * This one can be called for an ongoing RPC request, and can be used in
307 * an async (rpciod) context.
308 */
309 void rpcb_getport_async(struct rpc_task *task)
310 {
311 struct rpc_clnt *clnt = task->tk_client;
312 int bind_version;
313 struct rpc_xprt *xprt = task->tk_xprt;
314 struct rpc_clnt *rpcb_clnt;
315 static struct rpcbind_args *map;
316 struct rpc_task *child;
317 struct sockaddr addr;
318 int status;
319
320 dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
321 task->tk_pid, __FUNCTION__,
322 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
323
324 /* Autobind on cloned rpc clients is discouraged */
325 BUG_ON(clnt->cl_parent != clnt);
326
327 if (xprt_test_and_set_binding(xprt)) {
328 status = -EACCES; /* tell caller to check again */
329 dprintk("RPC: %5u %s: waiting for another binder\n",
330 task->tk_pid, __FUNCTION__);
331 goto bailout_nowake;
332 }
333
334 /* Put self on queue before sending rpcbind request, in case
335 * rpcb_getport_done completes before we return from rpc_run_task */
336 rpc_sleep_on(&xprt->binding, task, NULL, NULL);
337
338 /* Someone else may have bound if we slept */
339 if (xprt_bound(xprt)) {
340 status = 0;
341 dprintk("RPC: %5u %s: already bound\n",
342 task->tk_pid, __FUNCTION__);
343 goto bailout_nofree;
344 }
345
346 if (rpcb_next_version[xprt->bind_index].rpc_proc == NULL) {
347 xprt->bind_index = 0;
348 status = -EACCES; /* tell caller to try again later */
349 dprintk("RPC: %5u %s: no more getport versions available\n",
350 task->tk_pid, __FUNCTION__);
351 goto bailout_nofree;
352 }
353 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
354
355 dprintk("RPC: %5u %s: trying rpcbind version %u\n",
356 task->tk_pid, __FUNCTION__, bind_version);
357
358 map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
359 if (!map) {
360 status = -ENOMEM;
361 dprintk("RPC: %5u %s: no memory available\n",
362 task->tk_pid, __FUNCTION__);
363 goto bailout_nofree;
364 }
365 map->r_prog = clnt->cl_prog;
366 map->r_vers = clnt->cl_vers;
367 map->r_prot = xprt->prot;
368 map->r_port = 0;
369 map->r_xprt = xprt_get(xprt);
370 map->r_netid = (xprt->prot == IPPROTO_TCP) ? RPCB_NETID_TCP :
371 RPCB_NETID_UDP;
372 memcpy(&map->r_addr, rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR),
373 sizeof(map->r_addr));
374 map->r_owner = RPCB_OWNER_STRING; /* ignored for GETADDR */
375
376 rpc_peeraddr(clnt, (void *)&addr, sizeof(addr));
377 rpcb_clnt = rpcb_create(clnt->cl_server, &addr, xprt->prot, bind_version, 0);
378 if (IS_ERR(rpcb_clnt)) {
379 status = PTR_ERR(rpcb_clnt);
380 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
381 task->tk_pid, __FUNCTION__, PTR_ERR(rpcb_clnt));
382 goto bailout;
383 }
384
385 child = rpc_run_task(rpcb_clnt, RPC_TASK_ASYNC, &rpcb_getport_ops, map);
386 rpc_release_client(rpcb_clnt);
387 if (IS_ERR(child)) {
388 status = -EIO;
389 dprintk("RPC: %5u %s: rpc_run_task failed\n",
390 task->tk_pid, __FUNCTION__);
391 goto bailout_nofree;
392 }
393 rpc_put_task(child);
394
395 task->tk_xprt->stat.bind_count++;
396 return;
397
398 bailout:
399 kfree(map);
400 xprt_put(xprt);
401 bailout_nofree:
402 rpcb_wake_rpcbind_waiters(xprt, status);
403 bailout_nowake:
404 task->tk_status = status;
405 }
406
407 /*
408 * Rpcbind child task calls this callback via tk_exit.
409 */
410 static void rpcb_getport_done(struct rpc_task *child, void *data)
411 {
412 struct rpcbind_args *map = data;
413 struct rpc_xprt *xprt = map->r_xprt;
414 int status = child->tk_status;
415
416 /* rpcbind server doesn't support this rpcbind protocol version */
417 if (status == -EPROTONOSUPPORT)
418 xprt->bind_index++;
419
420 if (status < 0) {
421 /* rpcbind server not available on remote host? */
422 xprt->ops->set_port(xprt, 0);
423 } else if (map->r_port == 0) {
424 /* Requested RPC service wasn't registered on remote host */
425 xprt->ops->set_port(xprt, 0);
426 status = -EACCES;
427 } else {
428 /* Succeeded */
429 xprt->ops->set_port(xprt, map->r_port);
430 xprt_set_bound(xprt);
431 status = 0;
432 }
433
434 dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
435 child->tk_pid, status, map->r_port);
436
437 rpcb_wake_rpcbind_waiters(xprt, status);
438 }
439
440 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
441 struct rpcbind_args *rpcb)
442 {
443 dprintk("RPC: rpcb_encode_mapping(%u, %u, %d, %u)\n",
444 rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
445 *p++ = htonl(rpcb->r_prog);
446 *p++ = htonl(rpcb->r_vers);
447 *p++ = htonl(rpcb->r_prot);
448 *p++ = htonl(rpcb->r_port);
449
450 req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
451 return 0;
452 }
453
454 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
455 unsigned short *portp)
456 {
457 *portp = (unsigned short) ntohl(*p++);
458 dprintk("RPC: rpcb_decode_getport result %u\n",
459 *portp);
460 return 0;
461 }
462
463 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
464 unsigned int *boolp)
465 {
466 *boolp = (unsigned int) ntohl(*p++);
467 dprintk("RPC: rpcb_decode_set result %u\n",
468 *boolp);
469 return 0;
470 }
471
472 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
473 struct rpcbind_args *rpcb)
474 {
475 dprintk("RPC: rpcb_encode_getaddr(%u, %u, %s)\n",
476 rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
477 *p++ = htonl(rpcb->r_prog);
478 *p++ = htonl(rpcb->r_vers);
479
480 p = xdr_encode_string(p, rpcb->r_netid);
481 p = xdr_encode_string(p, rpcb->r_addr);
482 p = xdr_encode_string(p, rpcb->r_owner);
483
484 req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
485
486 return 0;
487 }
488
489 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
490 unsigned short *portp)
491 {
492 char *addr;
493 int addr_len, c, i, f, first, val;
494
495 *portp = 0;
496 addr_len = (unsigned int) ntohl(*p++);
497 if (addr_len > RPCB_MAXADDRLEN) /* sanity */
498 return -EINVAL;
499
500 dprintk("RPC: rpcb_decode_getaddr returned string: '%s'\n",
501 (char *) p);
502
503 addr = (char *)p;
504 val = 0;
505 first = 1;
506 f = 1;
507 for (i = addr_len - 1; i > 0; i--) {
508 c = addr[i];
509 if (c >= '0' && c <= '9') {
510 val += (c - '0') * f;
511 f *= 10;
512 } else if (c == '.') {
513 if (first) {
514 *portp = val;
515 val = first = 0;
516 f = 1;
517 } else {
518 *portp |= (val << 8);
519 break;
520 }
521 }
522 }
523
524 dprintk("RPC: rpcb_decode_getaddr port=%u\n", *portp);
525 return 0;
526 }
527
528 #define RPCB_program_sz (1u)
529 #define RPCB_version_sz (1u)
530 #define RPCB_protocol_sz (1u)
531 #define RPCB_port_sz (1u)
532 #define RPCB_boolean_sz (1u)
533
534 #define RPCB_netid_sz (1+XDR_QUADLEN(RPCB_MAXNETIDLEN))
535 #define RPCB_addr_sz (1+XDR_QUADLEN(RPCB_MAXADDRLEN))
536 #define RPCB_ownerstring_sz (1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
537
538 #define RPCB_mappingargs_sz RPCB_program_sz+RPCB_version_sz+ \
539 RPCB_protocol_sz+RPCB_port_sz
540 #define RPCB_getaddrargs_sz RPCB_program_sz+RPCB_version_sz+ \
541 RPCB_netid_sz+RPCB_addr_sz+ \
542 RPCB_ownerstring_sz
543
544 #define RPCB_setres_sz RPCB_boolean_sz
545 #define RPCB_getportres_sz RPCB_port_sz
546
547 /*
548 * Note that RFC 1833 does not put any size restrictions on the
549 * address string returned by the remote rpcbind database.
550 */
551 #define RPCB_getaddrres_sz RPCB_addr_sz
552
553 #define PROC(proc, argtype, restype) \
554 [RPCBPROC_##proc] = { \
555 .p_proc = RPCBPROC_##proc, \
556 .p_encode = (kxdrproc_t) rpcb_encode_##argtype, \
557 .p_decode = (kxdrproc_t) rpcb_decode_##restype, \
558 .p_arglen = RPCB_##argtype##args_sz, \
559 .p_replen = RPCB_##restype##res_sz, \
560 .p_statidx = RPCBPROC_##proc, \
561 .p_timer = 0, \
562 .p_name = #proc, \
563 }
564
565 /*
566 * Not all rpcbind procedures described in RFC 1833 are implemented
567 * since the Linux kernel RPC code requires only these.
568 */
569 static struct rpc_procinfo rpcb_procedures2[] = {
570 PROC(SET, mapping, set),
571 PROC(UNSET, mapping, set),
572 PROC(GETADDR, mapping, getport),
573 };
574
575 static struct rpc_procinfo rpcb_procedures3[] = {
576 PROC(SET, mapping, set),
577 PROC(UNSET, mapping, set),
578 PROC(GETADDR, getaddr, getaddr),
579 };
580
581 static struct rpc_procinfo rpcb_procedures4[] = {
582 PROC(SET, mapping, set),
583 PROC(UNSET, mapping, set),
584 PROC(GETVERSADDR, getaddr, getaddr),
585 };
586
587 static struct rpcb_info rpcb_next_version[] = {
588 #ifdef CONFIG_SUNRPC_BIND34
589 { 4, &rpcb_procedures4[RPCBPROC_GETVERSADDR] },
590 { 3, &rpcb_procedures3[RPCBPROC_GETADDR] },
591 #endif
592 { 2, &rpcb_procedures2[RPCBPROC_GETPORT] },
593 { 0, NULL },
594 };
595
596 static struct rpc_version rpcb_version2 = {
597 .number = 2,
598 .nrprocs = RPCB_HIGHPROC_2,
599 .procs = rpcb_procedures2
600 };
601
602 static struct rpc_version rpcb_version3 = {
603 .number = 3,
604 .nrprocs = RPCB_HIGHPROC_3,
605 .procs = rpcb_procedures3
606 };
607
608 static struct rpc_version rpcb_version4 = {
609 .number = 4,
610 .nrprocs = RPCB_HIGHPROC_4,
611 .procs = rpcb_procedures4
612 };
613
614 static struct rpc_version *rpcb_version[] = {
615 NULL,
616 NULL,
617 &rpcb_version2,
618 &rpcb_version3,
619 &rpcb_version4
620 };
621
622 static struct rpc_stat rpcb_stats;
623
624 struct rpc_program rpcb_program = {
625 .name = "rpcbind",
626 .number = RPCBIND_PROGRAM,
627 .nrvers = ARRAY_SIZE(rpcb_version),
628 .version = rpcb_version,
629 .stats = &rpcb_stats,
630 };