xref: /freebsd/sys/rpc/clnt_bck.c (revision e043f37205ffbde5627ff299ad25cd532f2956f0)
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  #include <sys/cdefs.h>
32  /*
33   * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
34   *
35   * Copyright (C) 1984, Sun Microsystems, Inc.
36   *
37   * TCP based RPC supports 'batched calls'.
38   * A sequence of calls may be batched-up in a send buffer.  The rpc call
39   * return immediately to the client even though the call was not necessarily
40   * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
41   * the rpc timeout value is zero (see clnt.h, rpc).
42   *
43   * Clients should NOT casually batch calls that in fact return results; that is,
44   * the server side should be aware that a call is batched and not produce any
45   * return message.  Batched calls that produce many result messages can
46   * deadlock (netlock) the client and the server....
47   *
48   * Now go hang yourself.
49   */
50  
51  /*
52   * This code handles the special case of a NFSv4.n backchannel for
53   * callback RPCs. It is similar to clnt_vc.c, but uses the TCP
54   * connection provided by the client to the server.
55   */
56  
57  #include "opt_kern_tls.h"
58  
59  #include <sys/param.h>
60  #include <sys/systm.h>
61  #include <sys/ktls.h>
62  #include <sys/lock.h>
63  #include <sys/malloc.h>
64  #include <sys/mbuf.h>
65  #include <sys/mutex.h>
66  #include <sys/pcpu.h>
67  #include <sys/proc.h>
68  #include <sys/protosw.h>
69  #include <sys/socket.h>
70  #include <sys/socketvar.h>
71  #include <sys/sx.h>
72  #include <sys/syslog.h>
73  #include <sys/time.h>
74  #include <sys/uio.h>
75  
76  #include <net/vnet.h>
77  
78  #include <netinet/tcp.h>
79  
80  #include <rpc/rpc.h>
81  #include <rpc/rpc_com.h>
82  #include <rpc/krpc.h>
83  #include <rpc/rpcsec_tls.h>
84  
85  struct cmessage {
86          struct cmsghdr cmsg;
87          struct cmsgcred cmcred;
88  };
89  
90  static void clnt_bck_geterr(CLIENT *, struct rpc_err *);
91  static bool_t clnt_bck_freeres(CLIENT *, xdrproc_t, void *);
92  static void clnt_bck_abort(CLIENT *);
93  static bool_t clnt_bck_control(CLIENT *, u_int, void *);
94  static void clnt_bck_close(CLIENT *);
95  static void clnt_bck_destroy(CLIENT *);
96  
97  static const struct clnt_ops clnt_bck_ops = {
98  	.cl_abort =	clnt_bck_abort,
99  	.cl_geterr =	clnt_bck_geterr,
100  	.cl_freeres =	clnt_bck_freeres,
101  	.cl_close =	clnt_bck_close,
102  	.cl_destroy =	clnt_bck_destroy,
103  	.cl_control =	clnt_bck_control
104  };
105  
106  /*
107   * Create a client handle for a connection.
108   * Default options are set, which the user can change using clnt_control()'s.
109   * This code handles the special case of an NFSv4.1 session backchannel
110   * call, which is sent on a TCP connection created against the server
111   * by a client.
112   */
113  void *
114  clnt_bck_create(
115  	struct socket *so,		/* Server transport socket. */
116  	const rpcprog_t prog,		/* program number */
117  	const rpcvers_t vers)		/* version number */
118  {
119  	CLIENT *cl;			/* client handle */
120  	struct ct_data *ct = NULL;	/* client handle */
121  	struct timeval now;
122  	struct rpc_msg call_msg;
123  	static uint32_t disrupt;
124  	XDR xdrs;
125  
126  	if (disrupt == 0)
127  		disrupt = (uint32_t)(long)so;
128  
129  	cl = (CLIENT *)mem_alloc(sizeof (*cl));
130  	ct = (struct ct_data *)mem_alloc(sizeof (*ct));
131  
132  	mtx_init(&ct->ct_lock, "ct->ct_lock", NULL, MTX_DEF);
133  	ct->ct_threads = 0;
134  	ct->ct_closing = FALSE;
135  	ct->ct_closed = FALSE;
136  	ct->ct_upcallrefs = 0;
137  	ct->ct_closeit = FALSE;
138  
139  	/*
140  	 * Set up private data struct
141  	 */
142  	ct->ct_wait.tv_sec = -1;
143  	ct->ct_wait.tv_usec = -1;
144  
145  	/*
146  	 * Initialize call message
147  	 */
148  	getmicrotime(&now);
149  	ct->ct_xid = ((uint32_t)++disrupt) ^ __RPC_GETXID(&now);
150  	call_msg.rm_xid = ct->ct_xid;
151  	call_msg.rm_direction = CALL;
152  	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
153  	call_msg.rm_call.cb_prog = (uint32_t)prog;
154  	call_msg.rm_call.cb_vers = (uint32_t)vers;
155  
156  	/*
157  	 * pre-serialize the static part of the call msg and stash it away
158  	 */
159  	xdrmem_create(&xdrs, ct->ct_mcallc, MCALL_MSG_SIZE,
160  	    XDR_ENCODE);
161  	if (!xdr_callhdr(&xdrs, &call_msg))
162  		goto err;
163  	ct->ct_mpos = XDR_GETPOS(&xdrs);
164  	XDR_DESTROY(&xdrs);
165  	ct->ct_waitchan = "rpcbck";
166  	ct->ct_waitflag = 0;
167  	cl->cl_refs = 1;
168  	cl->cl_ops = &clnt_bck_ops;
169  	cl->cl_private = ct;
170  	cl->cl_auth = authnone_create();
171  	TAILQ_INIT(&ct->ct_pending);
172  	return (cl);
173  
174  err:
175  	mtx_destroy(&ct->ct_lock);
176  	mem_free(ct, sizeof (struct ct_data));
177  	mem_free(cl, sizeof (CLIENT));
178  	return (NULL);
179  }
180  
181  enum clnt_stat
182  clnt_bck_call(
183  	CLIENT		*cl,		/* client handle */
184  	struct rpc_callextra *ext,	/* call metadata */
185  	rpcproc_t	proc,		/* procedure number */
186  	struct mbuf	*args,		/* pointer to args */
187  	struct mbuf	**resultsp,	/* pointer to results */
188  	struct timeval	utimeout,
189  	SVCXPRT		*xprt)
190  {
191  	struct ct_data *ct = (struct ct_data *) cl->cl_private;
192  	AUTH *auth;
193  	struct rpc_err *errp;
194  	enum clnt_stat stat;
195  	XDR xdrs;
196  	struct rpc_msg reply_msg;
197  	bool_t ok;
198  	int nrefreshes = 2;		/* number of times to refresh cred */
199  	struct timeval timeout;
200  	uint32_t xid;
201  	struct mbuf *mreq = NULL, *results;
202  	struct ct_request *cr;
203  	int error, maxextsiz;
204  #ifdef KERN_TLS
205  	u_int maxlen;
206  #endif
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  	/* For RPC-over-TLS, copy mrep to a chain of ext_pgs. */
300  	if ((xprt->xp_tls & RPCTLS_FLAGS_HANDSHAKE) != 0) {
301  		/*
302  		 * Copy the mbuf chain to a chain of
303  		 * ext_pgs mbuf(s) as required by KERN_TLS.
304  		 */
305  		maxextsiz = TLS_MAX_MSG_SIZE_V10_2;
306  #ifdef KERN_TLS
307  		if (rpctls_getinfo(&maxlen, false, false))
308  			maxextsiz = min(maxextsiz, maxlen);
309  #endif
310  		mreq = _rpc_copym_into_ext_pgs(mreq, maxextsiz);
311  	}
312  	/*
313  	 * sosend consumes mreq.
314  	 */
315  	sx_xlock(&xprt->xp_lock);
316  	error = sosend(xprt->xp_socket, NULL, NULL, mreq, NULL, 0, curthread);
317  if (error != 0) printf("sosend=%d\n", error);
318  	mreq = NULL;
319  	if (error == EMSGSIZE) {
320  printf("emsgsize\n");
321  		SOCKBUF_LOCK(&xprt->xp_socket->so_snd);
322  		sbwait(xprt->xp_socket, SO_SND);
323  		SOCKBUF_UNLOCK(&xprt->xp_socket->so_snd);
324  		sx_xunlock(&xprt->xp_lock);
325  		AUTH_VALIDATE(auth, xid, NULL, NULL);
326  		mtx_lock(&ct->ct_lock);
327  		TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
328  		goto call_again;
329  	}
330  	sx_xunlock(&xprt->xp_lock);
331  
332  	reply_msg.acpted_rply.ar_verf.oa_flavor = AUTH_NULL;
333  	reply_msg.acpted_rply.ar_verf.oa_base = cr->cr_verf;
334  	reply_msg.acpted_rply.ar_verf.oa_length = 0;
335  	reply_msg.acpted_rply.ar_results.where = NULL;
336  	reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
337  
338  	mtx_lock(&ct->ct_lock);
339  	if (error) {
340  		TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
341  		errp->re_errno = error;
342  		errp->re_status = stat = RPC_CANTSEND;
343  		goto out;
344  	}
345  
346  	/*
347  	 * Check to see if we got an upcall while waiting for the
348  	 * lock. In both these cases, the request has been removed
349  	 * from ct->ct_pending.
350  	 */
351  	if (cr->cr_error) {
352  		TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
353  		errp->re_errno = cr->cr_error;
354  		errp->re_status = stat = RPC_CANTRECV;
355  		goto out;
356  	}
357  	if (cr->cr_mrep) {
358  		TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
359  		goto got_reply;
360  	}
361  
362  	/*
363  	 * Hack to provide rpc-based message passing
364  	 */
365  	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
366  		TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
367  		errp->re_status = stat = RPC_TIMEDOUT;
368  		goto out;
369  	}
370  
371  	error = msleep(cr, &ct->ct_lock, ct->ct_waitflag, ct->ct_waitchan,
372  	    tvtohz(&timeout));
373  
374  	TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
375  
376  	if (error) {
377  		/*
378  		 * The sleep returned an error so our request is still
379  		 * on the list. Turn the error code into an
380  		 * appropriate client status.
381  		 */
382  		errp->re_errno = error;
383  		switch (error) {
384  		case EINTR:
385  			stat = RPC_INTR;
386  			break;
387  		case EWOULDBLOCK:
388  			stat = RPC_TIMEDOUT;
389  			break;
390  		default:
391  			stat = RPC_CANTRECV;
392  		}
393  		errp->re_status = stat;
394  		goto out;
395  	} else {
396  		/*
397  		 * We were woken up by the svc thread.  If the
398  		 * upcall had a receive error, report that,
399  		 * otherwise we have a reply.
400  		 */
401  		if (cr->cr_error) {
402  			errp->re_errno = cr->cr_error;
403  			errp->re_status = stat = RPC_CANTRECV;
404  			goto out;
405  		}
406  	}
407  
408  got_reply:
409  	/*
410  	 * Now decode and validate the response. We need to drop the
411  	 * lock since xdr_replymsg may end up sleeping in malloc.
412  	 */
413  	mtx_unlock(&ct->ct_lock);
414  
415  	if (ext && ext->rc_feedback)
416  		ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
417  
418  	xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
419  	ok = xdr_replymsg(&xdrs, &reply_msg);
420  	cr->cr_mrep = NULL;
421  
422  	if (ok) {
423  		if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
424  		    (reply_msg.acpted_rply.ar_stat == SUCCESS))
425  			errp->re_status = stat = RPC_SUCCESS;
426  		else
427  			stat = _seterr_reply(&reply_msg, errp);
428  
429  		if (stat == RPC_SUCCESS) {
430  			results = xdrmbuf_getall(&xdrs);
431  			if (!AUTH_VALIDATE(auth, xid,
432  			    &reply_msg.acpted_rply.ar_verf, &results)) {
433  				errp->re_status = stat = RPC_AUTHERROR;
434  				errp->re_why = AUTH_INVALIDRESP;
435  			} else {
436  				KASSERT(results,
437  				    ("auth validated but no result"));
438  				*resultsp = results;
439  			}
440  		}		/* end successful completion */
441  		/*
442  		 * If unsuccessful AND error is an authentication error
443  		 * then refresh credentials and try again, else break
444  		 */
445  		else if (stat == RPC_AUTHERROR)
446  			/* maybe our credentials need to be refreshed ... */
447  			if (nrefreshes > 0 && AUTH_REFRESH(auth, &reply_msg)) {
448  				nrefreshes--;
449  				XDR_DESTROY(&xdrs);
450  				mtx_lock(&ct->ct_lock);
451  				goto call_again;
452  			}
453  			/* end of unsuccessful completion */
454  		/* end of valid reply message */
455  	} else
456  		errp->re_status = stat = RPC_CANTDECODERES;
457  	XDR_DESTROY(&xdrs);
458  	mtx_lock(&ct->ct_lock);
459  out:
460  	mtx_assert(&ct->ct_lock, MA_OWNED);
461  
462  	KASSERT(stat != RPC_SUCCESS || *resultsp,
463  	    ("RPC_SUCCESS without reply"));
464  
465  	if (mreq != NULL)
466  		m_freem(mreq);
467  	if (cr->cr_mrep != NULL)
468  		m_freem(cr->cr_mrep);
469  
470  	ct->ct_threads--;
471  	if (ct->ct_closing)
472  		wakeup(ct);
473  
474  	mtx_unlock(&ct->ct_lock);
475  
476  	if (auth && stat != RPC_SUCCESS)
477  		AUTH_VALIDATE(auth, xid, NULL, NULL);
478  
479  	free(cr, M_RPC);
480  
481  	return (stat);
482  }
483  
484  static void
485  clnt_bck_geterr(CLIENT *cl, struct rpc_err *errp)
486  {
487  	struct ct_data *ct = (struct ct_data *) cl->cl_private;
488  
489  	*errp = ct->ct_error;
490  }
491  
492  static bool_t
493  clnt_bck_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
494  {
495  	XDR xdrs;
496  	bool_t dummy;
497  
498  	xdrs.x_op = XDR_FREE;
499  	dummy = (*xdr_res)(&xdrs, res_ptr);
500  
501  	return (dummy);
502  }
503  
504  /*ARGSUSED*/
505  static void
506  clnt_bck_abort(CLIENT *cl)
507  {
508  }
509  
510  static bool_t
511  clnt_bck_control(CLIENT *cl, u_int request, void *info)
512  {
513  
514  	return (TRUE);
515  }
516  
517  static void
518  clnt_bck_close(CLIENT *cl)
519  {
520  	struct ct_data *ct = (struct ct_data *) cl->cl_private;
521  
522  	mtx_lock(&ct->ct_lock);
523  
524  	if (ct->ct_closed) {
525  		mtx_unlock(&ct->ct_lock);
526  		return;
527  	}
528  
529  	if (ct->ct_closing) {
530  		while (ct->ct_closing)
531  			msleep(ct, &ct->ct_lock, 0, "rpcclose", 0);
532  		KASSERT(ct->ct_closed, ("client should be closed"));
533  		mtx_unlock(&ct->ct_lock);
534  		return;
535  	}
536  
537  	ct->ct_closing = FALSE;
538  	ct->ct_closed = TRUE;
539  	mtx_unlock(&ct->ct_lock);
540  	wakeup(ct);
541  }
542  
543  static void
544  clnt_bck_destroy(CLIENT *cl)
545  {
546  	struct ct_data *ct = (struct ct_data *) cl->cl_private;
547  
548  	clnt_bck_close(cl);
549  
550  	mtx_destroy(&ct->ct_lock);
551  	mem_free(ct, sizeof(struct ct_data));
552  	if (cl->cl_netid && cl->cl_netid[0])
553  		mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
554  	if (cl->cl_tp && cl->cl_tp[0])
555  		mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
556  	mem_free(cl, sizeof(CLIENT));
557  }
558  
559  /*
560   * This call is done by the svc code when a backchannel RPC reply is
561   * received.
562   * For the server end, where callback RPCs to the client are performed,
563   * xp_p2 points to the "CLIENT" and not the associated "struct ct_data"
564   * so that svc_vc_destroy() can CLNT_RELEASE() the reference count on it.
565   */
566  void
567  clnt_bck_svccall(void *arg, struct mbuf *mrep, uint32_t xid)
568  {
569  	CLIENT *cl = (CLIENT *)arg;
570  	struct ct_data *ct;
571  	struct ct_request *cr;
572  	int foundreq;
573  
574  	ct = (struct ct_data *)cl->cl_private;
575  	mtx_lock(&ct->ct_lock);
576  	if (ct->ct_closing || ct->ct_closed) {
577  		mtx_unlock(&ct->ct_lock);
578  		m_freem(mrep);
579  		return;
580  	}
581  
582  	ct->ct_upcallrefs++;
583  	/*
584  	 * See if we can match this reply to a request.
585  	 */
586  	foundreq = 0;
587  	TAILQ_FOREACH(cr, &ct->ct_pending, cr_link) {
588  		if (cr->cr_xid == xid) {
589  			/*
590  			 * This one matches. We leave the reply mbuf list in
591  			 * cr->cr_mrep. Set the XID to zero so that we will
592  			 * ignore any duplicated replies.
593  			 */
594  			cr->cr_xid = 0;
595  			cr->cr_mrep = mrep;
596  			cr->cr_error = 0;
597  			foundreq = 1;
598  			wakeup(cr);
599  			break;
600  		}
601  	}
602  
603  	ct->ct_upcallrefs--;
604  	if (ct->ct_upcallrefs < 0)
605  		panic("rpcvc svccall refcnt");
606  	if (ct->ct_upcallrefs == 0)
607  		wakeup(&ct->ct_upcallrefs);
608  	mtx_unlock(&ct->ct_lock);
609  	if (foundreq == 0)
610  		m_freem(mrep);
611  }
612  
613