xref: /freebsd/sys/rpc/clnt_bck.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc) 
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("$FreeBSD$");
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 
589