clnt_rc.c revision 184588 
1/*-
2 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
3 * Authors: Doug Rabson <dfr@rabson.org>
4 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/sys/rpc/clnt_rc.c 184588 2008-11-03 10:38:00Z dfr $");
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/kernel.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/malloc.h>
37#include <sys/mbuf.h>
38#include <sys/mutex.h>
39#include <sys/pcpu.h>
40#include <sys/proc.h>
41#include <sys/socket.h>
42#include <sys/socketvar.h>
43#include <sys/time.h>
44#include <sys/uio.h>
45
46#include <rpc/rpc.h>
47#include <rpc/rpc_com.h>
48
49static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *,
50    rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
51static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *);
52static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *);
53static void clnt_reconnect_abort(CLIENT *);
54static bool_t clnt_reconnect_control(CLIENT *, u_int, void *);
55static void clnt_reconnect_close(CLIENT *);
56static void clnt_reconnect_destroy(CLIENT *);
57
58static struct clnt_ops clnt_reconnect_ops = {
59	.cl_call =	clnt_reconnect_call,
60	.cl_abort =	clnt_reconnect_abort,
61	.cl_geterr =	clnt_reconnect_geterr,
62	.cl_freeres =	clnt_reconnect_freeres,
63	.cl_close =	clnt_reconnect_close,
64	.cl_destroy =	clnt_reconnect_destroy,
65	.cl_control =	clnt_reconnect_control
66};
67
68static int	fake_wchan;
69
70struct rc_data {
71	struct mtx		rc_lock;
72	struct sockaddr_storage	rc_addr; /* server address */
73	struct netconfig*	rc_nconf; /* network type */
74	rpcprog_t		rc_prog;  /* program number */
75	rpcvers_t		rc_vers;  /* version number */
76	size_t			rc_sendsz;
77	size_t			rc_recvsz;
78	struct timeval		rc_timeout;
79	struct timeval		rc_retry;
80	int			rc_retries;
81	int			rc_privport;
82	char			*rc_waitchan;
83	int			rc_intr;
84	int			rc_connecting;
85	int			rc_closed;
86	struct ucred		*rc_ucred;
87	CLIENT*			rc_client; /* underlying RPC client */
88	struct rpc_err		rc_err;
89};
90
91CLIENT *
92clnt_reconnect_create(
93	struct netconfig *nconf,	/* network type */
94	struct sockaddr *svcaddr,	/* servers address */
95	rpcprog_t program,		/* program number */
96	rpcvers_t version,		/* version number */
97	size_t sendsz,			/* buffer recv size */
98	size_t recvsz)			/* buffer send size */
99{
100	CLIENT *cl = NULL;		/* client handle */
101	struct rc_data *rc = NULL;	/* private data */
102
103	if (svcaddr == NULL) {
104		rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
105		return (NULL);
106	}
107
108	cl = mem_alloc(sizeof (CLIENT));
109	rc = mem_alloc(sizeof (*rc));
110	mtx_init(&rc->rc_lock, "rc->rc_lock", NULL, MTX_DEF);
111	(void) memcpy(&rc->rc_addr, svcaddr, (size_t)svcaddr->sa_len);
112	rc->rc_nconf = nconf;
113	rc->rc_prog = program;
114	rc->rc_vers = version;
115	rc->rc_sendsz = sendsz;
116	rc->rc_recvsz = recvsz;
117	rc->rc_timeout.tv_sec = -1;
118	rc->rc_timeout.tv_usec = -1;
119	rc->rc_retry.tv_sec = 3;
120	rc->rc_retry.tv_usec = 0;
121	rc->rc_retries = INT_MAX;
122	rc->rc_privport = FALSE;
123	rc->rc_waitchan = "rpcrecv";
124	rc->rc_intr = 0;
125	rc->rc_connecting = FALSE;
126	rc->rc_closed = FALSE;
127	rc->rc_ucred = crdup(curthread->td_ucred);
128	rc->rc_client = NULL;
129
130	cl->cl_refs = 1;
131	cl->cl_ops = &clnt_reconnect_ops;
132	cl->cl_private = (caddr_t)(void *)rc;
133	cl->cl_auth = authnone_create();
134	cl->cl_tp = NULL;
135	cl->cl_netid = NULL;
136	return (cl);
137}
138
139static enum clnt_stat
140clnt_reconnect_connect(CLIENT *cl)
141{
142	struct thread *td = curthread;
143	struct rc_data *rc = (struct rc_data *)cl->cl_private;
144	struct socket *so;
145	enum clnt_stat stat;
146	int error;
147	int one = 1;
148	struct ucred *oldcred;
149
150	mtx_lock(&rc->rc_lock);
151again:
152	if (rc->rc_closed) {
153		mtx_unlock(&rc->rc_lock);
154		return (RPC_CANTSEND);
155	}
156	if (rc->rc_connecting) {
157		while (!rc->rc_closed && !rc->rc_client) {
158			error = msleep(rc, &rc->rc_lock,
159			    rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
160			if (error) {
161				mtx_unlock(&rc->rc_lock);
162				return (RPC_INTR);
163			}
164		}
165		/*
166		 * If the other guy failed to connect, we might as
167		 * well have another go.
168		 */
169		if (!rc->rc_client && !rc->rc_connecting)
170			goto again;
171		mtx_unlock(&rc->rc_lock);
172		return (RPC_SUCCESS);
173	} else {
174		rc->rc_connecting = TRUE;
175	}
176	mtx_unlock(&rc->rc_lock);
177
178	so = __rpc_nconf2socket(rc->rc_nconf);
179	if (!so) {
180		stat = rpc_createerr.cf_stat = RPC_TLIERROR;
181		rpc_createerr.cf_error.re_errno = 0;
182		goto out;
183	}
184	if (rc->rc_privport)
185		bindresvport(so, NULL);
186
187	oldcred = td->td_ucred;
188	td->td_ucred = rc->rc_ucred;
189	if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
190		rc->rc_client = clnt_dg_create(so,
191		    (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
192		    rc->rc_sendsz, rc->rc_recvsz);
193	else
194		rc->rc_client = clnt_vc_create(so,
195		    (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
196		    rc->rc_sendsz, rc->rc_recvsz);
197	td->td_ucred = oldcred;
198
199	if (!rc->rc_client) {
200		soclose(so);
201		rc->rc_err = rpc_createerr.cf_error;
202		stat = rpc_createerr.cf_stat;
203		goto out;
204	}
205
206	CLNT_CONTROL(rc->rc_client, CLSET_FD_CLOSE, 0);
207	CLNT_CONTROL(rc->rc_client, CLSET_CONNECT, &one);
208	CLNT_CONTROL(rc->rc_client, CLSET_TIMEOUT, &rc->rc_timeout);
209	CLNT_CONTROL(rc->rc_client, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
210	CLNT_CONTROL(rc->rc_client, CLSET_WAITCHAN, rc->rc_waitchan);
211	CLNT_CONTROL(rc->rc_client, CLSET_INTERRUPTIBLE, &rc->rc_intr);
212	stat = RPC_SUCCESS;
213
214out:
215	mtx_lock(&rc->rc_lock);
216	if (rc->rc_closed) {
217		if (rc->rc_client) {
218			CLNT_CLOSE(rc->rc_client);
219			CLNT_RELEASE(rc->rc_client);
220			rc->rc_client = NULL;
221		}
222	}
223	rc->rc_connecting = FALSE;
224	wakeup(rc);
225	mtx_unlock(&rc->rc_lock);
226
227	return (stat);
228}
229
230static enum clnt_stat
231clnt_reconnect_call(
232	CLIENT		*cl,		/* client handle */
233	struct rpc_callextra *ext,	/* call metadata */
234	rpcproc_t	proc,		/* procedure number */
235	struct mbuf	*args,		/* pointer to args */
236	struct mbuf	**resultsp,	/* pointer to results */
237	struct timeval	utimeout)
238{
239	struct rc_data *rc = (struct rc_data *)cl->cl_private;
240	CLIENT *client;
241	enum clnt_stat stat;
242	int tries;
243
244	tries = 0;
245	do {
246		if (rc->rc_closed) {
247			return (RPC_CANTSEND);
248		}
249
250		if (!rc->rc_client) {
251			stat = clnt_reconnect_connect(cl);
252			if (stat == RPC_SYSTEMERROR) {
253				(void) tsleep(&fake_wchan, 0,
254				    "rpccon", hz);
255				tries++;
256				if (tries >= rc->rc_retries)
257					return (stat);
258				continue;
259			}
260			if (stat != RPC_SUCCESS)
261				return (stat);
262		}
263
264		mtx_lock(&rc->rc_lock);
265		if (!rc->rc_client) {
266			mtx_unlock(&rc->rc_lock);
267			stat = RPC_FAILED;
268			continue;
269		}
270		CLNT_ACQUIRE(rc->rc_client);
271		client = rc->rc_client;
272		mtx_unlock(&rc->rc_lock);
273		stat = CLNT_CALL_MBUF(client, ext, proc, args,
274		    resultsp, utimeout);
275
276		if (stat != RPC_SUCCESS) {
277			if (!ext)
278				CLNT_GETERR(client, &rc->rc_err);
279		}
280
281		CLNT_RELEASE(client);
282		if (stat == RPC_TIMEDOUT) {
283			/*
284			 * Check for async send misfeature for NLM
285			 * protocol.
286			 */
287			if ((rc->rc_timeout.tv_sec == 0
288				&& rc->rc_timeout.tv_usec == 0)
289			    || (rc->rc_timeout.tv_sec == -1
290				&& utimeout.tv_sec == 0
291				&& utimeout.tv_usec == 0)) {
292				break;
293			}
294		}
295
296		if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
297		    || stat == RPC_CANTRECV) {
298			tries++;
299			if (tries >= rc->rc_retries)
300				break;
301
302			if (ext && ext->rc_feedback)
303				ext->rc_feedback(FEEDBACK_RECONNECT, proc,
304				    ext->rc_feedback_arg);
305
306			mtx_lock(&rc->rc_lock);
307			/*
308			 * Make sure that someone else hasn't already
309			 * reconnected.
310			 */
311			if (rc->rc_client == client) {
312				CLNT_RELEASE(rc->rc_client);
313				rc->rc_client = NULL;
314			}
315			mtx_unlock(&rc->rc_lock);
316		} else {
317			break;
318		}
319	} while (stat != RPC_SUCCESS);
320
321	KASSERT(stat != RPC_SUCCESS || *resultsp,
322	    ("RPC_SUCCESS without reply"));
323
324	return (stat);
325}
326
327static void
328clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp)
329{
330	struct rc_data *rc = (struct rc_data *)cl->cl_private;
331
332	*errp = rc->rc_err;
333}
334
335static bool_t
336clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
337{
338	struct rc_data *rc = (struct rc_data *)cl->cl_private;
339
340	return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr));
341}
342
343/*ARGSUSED*/
344static void
345clnt_reconnect_abort(CLIENT *h)
346{
347}
348
349static bool_t
350clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
351{
352	struct rc_data *rc = (struct rc_data *)cl->cl_private;
353
354	if (info == NULL) {
355		return (FALSE);
356	}
357	switch (request) {
358	case CLSET_TIMEOUT:
359		rc->rc_timeout = *(struct timeval *)info;
360		if (rc->rc_client)
361			CLNT_CONTROL(rc->rc_client, request, info);
362		break;
363
364	case CLGET_TIMEOUT:
365		*(struct timeval *)info = rc->rc_timeout;
366		break;
367
368	case CLSET_RETRY_TIMEOUT:
369		rc->rc_retry = *(struct timeval *)info;
370		if (rc->rc_client)
371			CLNT_CONTROL(rc->rc_client, request, info);
372		break;
373
374	case CLGET_RETRY_TIMEOUT:
375		*(struct timeval *)info = rc->rc_retry;
376		break;
377
378	case CLGET_VERS:
379		*(uint32_t *)info = rc->rc_vers;
380		break;
381
382	case CLSET_VERS:
383		rc->rc_vers = *(uint32_t *) info;
384		if (rc->rc_client)
385			CLNT_CONTROL(rc->rc_client, CLSET_VERS, info);
386		break;
387
388	case CLGET_PROG:
389		*(uint32_t *)info = rc->rc_prog;
390		break;
391
392	case CLSET_PROG:
393		rc->rc_prog = *(uint32_t *) info;
394		if (rc->rc_client)
395			CLNT_CONTROL(rc->rc_client, request, info);
396		break;
397
398	case CLSET_WAITCHAN:
399		rc->rc_waitchan = (char *)info;
400		if (rc->rc_client)
401			CLNT_CONTROL(rc->rc_client, request, info);
402		break;
403
404	case CLGET_WAITCHAN:
405		*(const char **) info = rc->rc_waitchan;
406		break;
407
408	case CLSET_INTERRUPTIBLE:
409		rc->rc_intr = *(int *) info;
410		if (rc->rc_client)
411			CLNT_CONTROL(rc->rc_client, request, info);
412		break;
413
414	case CLGET_INTERRUPTIBLE:
415		*(int *) info = rc->rc_intr;
416		break;
417
418	case CLSET_RETRIES:
419		rc->rc_retries = *(int *) info;
420		break;
421
422	case CLGET_RETRIES:
423		*(int *) info = rc->rc_retries;
424		break;
425
426	case CLSET_PRIVPORT:
427		rc->rc_privport = *(int *) info;
428		break;
429
430	case CLGET_PRIVPORT:
431		*(int *) info = rc->rc_privport;
432		break;
433
434	default:
435		return (FALSE);
436	}
437
438	return (TRUE);
439}
440
441static void
442clnt_reconnect_close(CLIENT *cl)
443{
444	struct rc_data *rc = (struct rc_data *)cl->cl_private;
445	CLIENT *client;
446
447	mtx_lock(&rc->rc_lock);
448
449	if (rc->rc_closed) {
450		mtx_unlock(&rc->rc_lock);
451		return;
452	}
453
454	rc->rc_closed = TRUE;
455	client = rc->rc_client;
456	rc->rc_client = NULL;
457
458	mtx_unlock(&rc->rc_lock);
459
460	if (client) {
461		CLNT_CLOSE(client);
462		CLNT_RELEASE(client);
463	}
464}
465
466static void
467clnt_reconnect_destroy(CLIENT *cl)
468{
469	struct rc_data *rc = (struct rc_data *)cl->cl_private;
470
471	if (rc->rc_client)
472		CLNT_DESTROY(rc->rc_client);
473	crfree(rc->rc_ucred);
474	mtx_destroy(&rc->rc_lock);
475	mem_free(rc, sizeof(*rc));
476	mem_free(cl, sizeof (CLIENT));
477}
478