xref: /freebsd/sys/rpc/clnt_rc.c (revision 9162f64b58d01ec01481d60b6cdc06ffd8e8c7fc)
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("$FreeBSD$");
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 
49 static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *,
50     rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
51 static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *);
52 static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *);
53 static void clnt_reconnect_abort(CLIENT *);
54 static bool_t clnt_reconnect_control(CLIENT *, u_int, void *);
55 static void clnt_reconnect_close(CLIENT *);
56 static void clnt_reconnect_destroy(CLIENT *);
57 
58 static 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 
68 static int	fake_wchan;
69 
70 struct 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 
91 CLIENT *
92 clnt_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 
139 static enum clnt_stat
140 clnt_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);
151 again:
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 
214 out:
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 
230 static enum clnt_stat
231 clnt_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 
327 static void
328 clnt_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 
335 static bool_t
336 clnt_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*/
344 static void
345 clnt_reconnect_abort(CLIENT *h)
346 {
347 }
348 
349 static bool_t
350 clnt_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 
441 static void
442 clnt_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 
466 static void
467 clnt_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