FreeBSD/Linux Kernel Cross Reference
sys/rpc/clnt_bck.c
1 /* $NetBSD: clnt_vc.c,v 1.4 2000/07/14 08:40:42 fvdl Exp $ */
2
3 /*-
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char *sccsid2 = "@(#)clnt_tcp.c 1.37 87/10/05 Copyr 1984 Sun Micro";
33 static char *sccsid = "@(#)clnt_tcp.c 2.2 88/08/01 4.0 RPCSRC";
34 static char sccsid3[] = "@(#)clnt_vc.c 1.19 89/03/16 Copyr 1988 Sun Micro";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD: releng/11.2/sys/rpc/clnt_bck.c 301800 2016-06-10 17:53:28Z ngie $");
38
39 /*
40 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
41 *
42 * Copyright (C) 1984, Sun Microsystems, Inc.
43 *
44 * TCP based RPC supports 'batched calls'.
45 * A sequence of calls may be batched-up in a send buffer. The rpc call
46 * return immediately to the client even though the call was not necessarily
47 * sent. The batching occurs if the results' xdr routine is NULL (0) AND
48 * the rpc timeout value is zero (see clnt.h, rpc).
49 *
50 * Clients should NOT casually batch calls that in fact return results; that is,
51 * the server side should be aware that a call is batched and not produce any
52 * return message. Batched calls that produce many result messages can
53 * deadlock (netlock) the client and the server....
54 *
55 * Now go hang yourself.
56 */
57
58 /*
59 * This code handles the special case of a NFSv4.n backchannel for
60 * callback RPCs. It is similar to clnt_vc.c, but uses the TCP
61 * connection provided by the client to the server.
62 */
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/lock.h>
67 #include <sys/malloc.h>
68 #include <sys/mbuf.h>
69 #include <sys/mutex.h>
70 #include <sys/pcpu.h>
71 #include <sys/proc.h>
72 #include <sys/protosw.h>
73 #include <sys/socket.h>
74 #include <sys/socketvar.h>
75 #include <sys/sx.h>
76 #include <sys/syslog.h>
77 #include <sys/time.h>
78 #include <sys/uio.h>
79
80 #include <net/vnet.h>
81
82 #include <netinet/tcp.h>
83
84 #include <rpc/rpc.h>
85 #include <rpc/rpc_com.h>
86 #include <rpc/krpc.h>
87
88 struct cmessage {
89 struct cmsghdr cmsg;
90 struct cmsgcred cmcred;
91 };
92
93 static void clnt_bck_geterr(CLIENT *, struct rpc_err *);
94 static bool_t clnt_bck_freeres(CLIENT *, xdrproc_t, void *);
95 static void clnt_bck_abort(CLIENT *);
96 static bool_t clnt_bck_control(CLIENT *, u_int, void *);
97 static void clnt_bck_close(CLIENT *);
98 static void clnt_bck_destroy(CLIENT *);
99
100 static struct clnt_ops clnt_bck_ops = {
101 .cl_abort = clnt_bck_abort,
102 .cl_geterr = clnt_bck_geterr,
103 .cl_freeres = clnt_bck_freeres,
104 .cl_close = clnt_bck_close,
105 .cl_destroy = clnt_bck_destroy,
106 .cl_control = clnt_bck_control
107 };
108
109 /*
110 * Create a client handle for a connection.
111 * Default options are set, which the user can change using clnt_control()'s.
112 * This code handles the special case of an NFSv4.1 session backchannel
113 * call, which is sent on a TCP connection created against the server
114 * by a client.
115 */
116 void *
117 clnt_bck_create(
118 struct socket *so, /* Server transport socket. */
119 const rpcprog_t prog, /* program number */
120 const rpcvers_t vers) /* version number */
121 {
122 CLIENT *cl; /* client handle */
123 struct ct_data *ct = NULL; /* client handle */
124 struct timeval now;
125 struct rpc_msg call_msg;
126 static uint32_t disrupt;
127 XDR xdrs;
128
129 if (disrupt == 0)
130 disrupt = (uint32_t)(long)so;
131
132 cl = (CLIENT *)mem_alloc(sizeof (*cl));
133 ct = (struct ct_data *)mem_alloc(sizeof (*ct));
134
135 mtx_init(&ct->ct_lock, "ct->ct_lock", NULL, MTX_DEF);
136 ct->ct_threads = 0;
137 ct->ct_closing = FALSE;
138 ct->ct_closed = FALSE;
139 ct->ct_upcallrefs = 0;
140 ct->ct_closeit = FALSE;
141
142 /*
143 * Set up private data struct
144 */
145 ct->ct_wait.tv_sec = -1;
146 ct->ct_wait.tv_usec = -1;
147
148 /*
149 * Initialize call message
150 */
151 getmicrotime(&now);
152 ct->ct_xid = ((uint32_t)++disrupt) ^ __RPC_GETXID(&now);
153 call_msg.rm_xid = ct->ct_xid;
154 call_msg.rm_direction = CALL;
155 call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
156 call_msg.rm_call.cb_prog = (uint32_t)prog;
157 call_msg.rm_call.cb_vers = (uint32_t)vers;
158
159 /*
160 * pre-serialize the static part of the call msg and stash it away
161 */
162 xdrmem_create(&xdrs, ct->ct_mcallc, MCALL_MSG_SIZE,
163 XDR_ENCODE);
164 if (!xdr_callhdr(&xdrs, &call_msg))
165 goto err;
166 ct->ct_mpos = XDR_GETPOS(&xdrs);
167 XDR_DESTROY(&xdrs);
168 ct->ct_waitchan = "rpcbck";
169 ct->ct_waitflag = 0;
170 cl->cl_refs = 1;
171 cl->cl_ops = &clnt_bck_ops;
172 cl->cl_private = ct;
173 cl->cl_auth = authnone_create();
174 TAILQ_INIT(&ct->ct_pending);
175 return (cl);
176
177 err:
178 mtx_destroy(&ct->ct_lock);
179 mem_free(ct, sizeof (struct ct_data));
180 mem_free(cl, sizeof (CLIENT));
181 return (NULL);
182 }
183
184 enum clnt_stat
185 clnt_bck_call(
186 CLIENT *cl, /* client handle */
187 struct rpc_callextra *ext, /* call metadata */
188 rpcproc_t proc, /* procedure number */
189 struct mbuf *args, /* pointer to args */
190 struct mbuf **resultsp, /* pointer to results */
191 struct timeval utimeout,
192 SVCXPRT *xprt)
193 {
194 struct ct_data *ct = (struct ct_data *) cl->cl_private;
195 AUTH *auth;
196 struct rpc_err *errp;
197 enum clnt_stat stat;
198 XDR xdrs;
199 struct rpc_msg reply_msg;
200 bool_t ok;
201 int nrefreshes = 2; /* number of times to refresh cred */
202 struct timeval timeout;
203 uint32_t xid;
204 struct mbuf *mreq = NULL, *results;
205 struct ct_request *cr;
206 int error;
207
208 cr = malloc(sizeof(struct ct_request), M_RPC, M_WAITOK);
209
210 mtx_lock(&ct->ct_lock);
211
212 if (ct->ct_closing || ct->ct_closed) {
213 mtx_unlock(&ct->ct_lock);
214 free(cr, M_RPC);
215 return (RPC_CANTSEND);
216 }
217 ct->ct_threads++;
218
219 if (ext) {
220 auth = ext->rc_auth;
221 errp = &ext->rc_err;
222 } else {
223 auth = cl->cl_auth;
224 errp = &ct->ct_error;
225 }
226
227 cr->cr_mrep = NULL;
228 cr->cr_error = 0;
229
230 if (ct->ct_wait.tv_usec == -1)
231 timeout = utimeout; /* use supplied timeout */
232 else
233 timeout = ct->ct_wait; /* use default timeout */
234
235 call_again:
236 mtx_assert(&ct->ct_lock, MA_OWNED);
237
238 ct->ct_xid++;
239 xid = ct->ct_xid;
240
241 mtx_unlock(&ct->ct_lock);
242
243 /*
244 * Leave space to pre-pend the record mark.
245 */
246 mreq = m_gethdr(M_WAITOK, MT_DATA);
247 mreq->m_data += sizeof(uint32_t);
248 KASSERT(ct->ct_mpos + sizeof(uint32_t) <= MHLEN,
249 ("RPC header too big"));
250 bcopy(ct->ct_mcallc, mreq->m_data, ct->ct_mpos);
251 mreq->m_len = ct->ct_mpos;
252
253 /*
254 * The XID is the first thing in the request.
255 */
256 *mtod(mreq, uint32_t *) = htonl(xid);
257
258 xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
259
260 errp->re_status = stat = RPC_SUCCESS;
261
262 if ((!XDR_PUTINT32(&xdrs, &proc)) ||
263 (!AUTH_MARSHALL(auth, xid, &xdrs,
264 m_copym(args, 0, M_COPYALL, M_WAITOK)))) {
265 errp->re_status = stat = RPC_CANTENCODEARGS;
266 mtx_lock(&ct->ct_lock);
267 goto out;
268 }
269 mreq->m_pkthdr.len = m_length(mreq, NULL);
270
271 /*
272 * Prepend a record marker containing the packet length.
273 */
274 M_PREPEND(mreq, sizeof(uint32_t), M_WAITOK);
275 *mtod(mreq, uint32_t *) =
276 htonl(0x80000000 | (mreq->m_pkthdr.len - sizeof(uint32_t)));
277
278 cr->cr_xid = xid;
279 mtx_lock(&ct->ct_lock);
280 /*
281 * Check to see if the client end has already started to close down
282 * the connection. The svc code will have set ct_error.re_status
283 * to RPC_CANTRECV if this is the case.
284 * If the client starts to close down the connection after this
285 * point, it will be detected later when cr_error is checked,
286 * since the request is in the ct_pending queue.
287 */
288 if (ct->ct_error.re_status == RPC_CANTRECV) {
289 if (errp != &ct->ct_error) {
290 errp->re_errno = ct->ct_error.re_errno;
291 errp->re_status = RPC_CANTRECV;
292 }
293 stat = RPC_CANTRECV;
294 goto out;
295 }
296 TAILQ_INSERT_TAIL(&ct->ct_pending, cr, cr_link);
297 mtx_unlock(&ct->ct_lock);
298
299 /*
300 * sosend consumes mreq.
301 */
302 sx_xlock(&xprt->xp_lock);
303 error = sosend(xprt->xp_socket, NULL, NULL, mreq, NULL, 0, curthread);
304 if (error != 0) printf("sosend=%d\n", error);
305 mreq = NULL;
306 if (error == EMSGSIZE) {
307 printf("emsgsize\n");
308 SOCKBUF_LOCK(&xprt->xp_socket->so_snd);
309 sbwait(&xprt->xp_socket->so_snd);
310 SOCKBUF_UNLOCK(&xprt->xp_socket->so_snd);
311 sx_xunlock(&xprt->xp_lock);
312 AUTH_VALIDATE(auth, xid, NULL, NULL);
313 mtx_lock(&ct->ct_lock);
314 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
315 goto call_again;
316 }
317 sx_xunlock(&xprt->xp_lock);
318
319 reply_msg.acpted_rply.ar_verf.oa_flavor = AUTH_NULL;
320 reply_msg.acpted_rply.ar_verf.oa_base = cr->cr_verf;
321 reply_msg.acpted_rply.ar_verf.oa_length = 0;
322 reply_msg.acpted_rply.ar_results.where = NULL;
323 reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
324
325 mtx_lock(&ct->ct_lock);
326 if (error) {
327 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
328 errp->re_errno = error;
329 errp->re_status = stat = RPC_CANTSEND;
330 goto out;
331 }
332
333 /*
334 * Check to see if we got an upcall while waiting for the
335 * lock. In both these cases, the request has been removed
336 * from ct->ct_pending.
337 */
338 if (cr->cr_error) {
339 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
340 errp->re_errno = cr->cr_error;
341 errp->re_status = stat = RPC_CANTRECV;
342 goto out;
343 }
344 if (cr->cr_mrep) {
345 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
346 goto got_reply;
347 }
348
349 /*
350 * Hack to provide rpc-based message passing
351 */
352 if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
353 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
354 errp->re_status = stat = RPC_TIMEDOUT;
355 goto out;
356 }
357
358 error = msleep(cr, &ct->ct_lock, ct->ct_waitflag, ct->ct_waitchan,
359 tvtohz(&timeout));
360
361 TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
362
363 if (error) {
364 /*
365 * The sleep returned an error so our request is still
366 * on the list. Turn the error code into an
367 * appropriate client status.
368 */
369 errp->re_errno = error;
370 switch (error) {
371 case EINTR:
372 stat = RPC_INTR;
373 break;
374 case EWOULDBLOCK:
375 stat = RPC_TIMEDOUT;
376 break;
377 default:
378 stat = RPC_CANTRECV;
379 }
380 errp->re_status = stat;
381 goto out;
382 } else {
383 /*
384 * We were woken up by the svc thread. If the
385 * upcall had a receive error, report that,
386 * otherwise we have a reply.
387 */
388 if (cr->cr_error) {
389 errp->re_errno = cr->cr_error;
390 errp->re_status = stat = RPC_CANTRECV;
391 goto out;
392 }
393 }
394
395 got_reply:
396 /*
397 * Now decode and validate the response. We need to drop the
398 * lock since xdr_replymsg may end up sleeping in malloc.
399 */
400 mtx_unlock(&ct->ct_lock);
401
402 if (ext && ext->rc_feedback)
403 ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
404
405 xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
406 ok = xdr_replymsg(&xdrs, &reply_msg);
407 cr->cr_mrep = NULL;
408
409 if (ok) {
410 if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
411 (reply_msg.acpted_rply.ar_stat == SUCCESS))
412 errp->re_status = stat = RPC_SUCCESS;
413 else
414 stat = _seterr_reply(&reply_msg, errp);
415
416 if (stat == RPC_SUCCESS) {
417 results = xdrmbuf_getall(&xdrs);
418 if (!AUTH_VALIDATE(auth, xid,
419 &reply_msg.acpted_rply.ar_verf, &results)) {
420 errp->re_status = stat = RPC_AUTHERROR;
421 errp->re_why = AUTH_INVALIDRESP;
422 } else {
423 KASSERT(results,
424 ("auth validated but no result"));
425 *resultsp = results;
426 }
427 } /* end successful completion */
428 /*
429 * If unsuccessful AND error is an authentication error
430 * then refresh credentials and try again, else break
431 */
432 else if (stat == RPC_AUTHERROR)
433 /* maybe our credentials need to be refreshed ... */
434 if (nrefreshes > 0 && AUTH_REFRESH(auth, &reply_msg)) {
435 nrefreshes--;
436 XDR_DESTROY(&xdrs);
437 mtx_lock(&ct->ct_lock);
438 goto call_again;
439 }
440 /* end of unsuccessful completion */
441 /* end of valid reply message */
442 } else
443 errp->re_status = stat = RPC_CANTDECODERES;
444 XDR_DESTROY(&xdrs);
445 mtx_lock(&ct->ct_lock);
446 out:
447 mtx_assert(&ct->ct_lock, MA_OWNED);
448
449 KASSERT(stat != RPC_SUCCESS || *resultsp,
450 ("RPC_SUCCESS without reply"));
451
452 if (mreq != NULL)
453 m_freem(mreq);
454 if (cr->cr_mrep != NULL)
455 m_freem(cr->cr_mrep);
456
457 ct->ct_threads--;
458 if (ct->ct_closing)
459 wakeup(ct);
460
461 mtx_unlock(&ct->ct_lock);
462
463 if (auth && stat != RPC_SUCCESS)
464 AUTH_VALIDATE(auth, xid, NULL, NULL);
465
466 free(cr, M_RPC);
467
468 return (stat);
469 }
470
471 static void
472 clnt_bck_geterr(CLIENT *cl, struct rpc_err *errp)
473 {
474 struct ct_data *ct = (struct ct_data *) cl->cl_private;
475
476 *errp = ct->ct_error;
477 }
478
479 static bool_t
480 clnt_bck_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
481 {
482 XDR xdrs;
483 bool_t dummy;
484
485 xdrs.x_op = XDR_FREE;
486 dummy = (*xdr_res)(&xdrs, res_ptr);
487
488 return (dummy);
489 }
490
491 /*ARGSUSED*/
492 static void
493 clnt_bck_abort(CLIENT *cl)
494 {
495 }
496
497 static bool_t
498 clnt_bck_control(CLIENT *cl, u_int request, void *info)
499 {
500
501 return (TRUE);
502 }
503
504 static void
505 clnt_bck_close(CLIENT *cl)
506 {
507 struct ct_data *ct = (struct ct_data *) cl->cl_private;
508
509 mtx_lock(&ct->ct_lock);
510
511 if (ct->ct_closed) {
512 mtx_unlock(&ct->ct_lock);
513 return;
514 }
515
516 if (ct->ct_closing) {
517 while (ct->ct_closing)
518 msleep(ct, &ct->ct_lock, 0, "rpcclose", 0);
519 KASSERT(ct->ct_closed, ("client should be closed"));
520 mtx_unlock(&ct->ct_lock);
521 return;
522 }
523
524 ct->ct_closing = FALSE;
525 ct->ct_closed = TRUE;
526 mtx_unlock(&ct->ct_lock);
527 wakeup(ct);
528 }
529
530 static void
531 clnt_bck_destroy(CLIENT *cl)
532 {
533 struct ct_data *ct = (struct ct_data *) cl->cl_private;
534
535 clnt_bck_close(cl);
536
537 mtx_destroy(&ct->ct_lock);
538 mem_free(ct, sizeof(struct ct_data));
539 if (cl->cl_netid && cl->cl_netid[0])
540 mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
541 if (cl->cl_tp && cl->cl_tp[0])
542 mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
543 mem_free(cl, sizeof(CLIENT));
544 }
545
546 /*
547 * This call is done by the svc code when a backchannel RPC reply is
548 * received.
549 */
550 void
551 clnt_bck_svccall(void *arg, struct mbuf *mrep, uint32_t xid)
552 {
553 struct ct_data *ct = (struct ct_data *)arg;
554 struct ct_request *cr;
555 int foundreq;
556
557 mtx_lock(&ct->ct_lock);
558 ct->ct_upcallrefs++;
559 /*
560 * See if we can match this reply to a request.
561 */
562 foundreq = 0;
563 TAILQ_FOREACH(cr, &ct->ct_pending, cr_link) {
564 if (cr->cr_xid == xid) {
565 /*
566 * This one matches. We leave the reply mbuf list in
567 * cr->cr_mrep. Set the XID to zero so that we will
568 * ignore any duplicated replies.
569 */
570 cr->cr_xid = 0;
571 cr->cr_mrep = mrep;
572 cr->cr_error = 0;
573 foundreq = 1;
574 wakeup(cr);
575 break;
576 }
577 }
578
579 ct->ct_upcallrefs--;
580 if (ct->ct_upcallrefs < 0)
581 panic("rpcvc svccall refcnt");
582 if (ct->ct_upcallrefs == 0)
583 wakeup(&ct->ct_upcallrefs);
584 mtx_unlock(&ct->ct_lock);
585 if (foundreq == 0)
586 m_freem(mrep);
587 }
588
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