FreeBSD/Linux Kernel Cross Reference
sys/rpc/clnt_rc.c
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 #include <rpc/krpc.h>
49
50 static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *,
51 rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
52 static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *);
53 static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *);
54 static void clnt_reconnect_abort(CLIENT *);
55 static bool_t clnt_reconnect_control(CLIENT *, u_int, void *);
56 static void clnt_reconnect_close(CLIENT *);
57 static void clnt_reconnect_destroy(CLIENT *);
58
59 static struct clnt_ops clnt_reconnect_ops = {
60 .cl_call = clnt_reconnect_call,
61 .cl_abort = clnt_reconnect_abort,
62 .cl_geterr = clnt_reconnect_geterr,
63 .cl_freeres = clnt_reconnect_freeres,
64 .cl_close = clnt_reconnect_close,
65 .cl_destroy = clnt_reconnect_destroy,
66 .cl_control = clnt_reconnect_control
67 };
68
69 static int fake_wchan;
70
71 CLIENT *
72 clnt_reconnect_create(
73 struct netconfig *nconf, /* network type */
74 struct sockaddr *svcaddr, /* servers address */
75 rpcprog_t program, /* program number */
76 rpcvers_t version, /* version number */
77 size_t sendsz, /* buffer recv size */
78 size_t recvsz) /* buffer send size */
79 {
80 CLIENT *cl = NULL; /* client handle */
81 struct rc_data *rc = NULL; /* private data */
82
83 if (svcaddr == NULL) {
84 rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
85 return (NULL);
86 }
87
88 cl = mem_alloc(sizeof (CLIENT));
89 rc = mem_alloc(sizeof (*rc));
90 mtx_init(&rc->rc_lock, "rc->rc_lock", NULL, MTX_DEF);
91 (void) memcpy(&rc->rc_addr, svcaddr, (size_t)svcaddr->sa_len);
92 rc->rc_nconf = nconf;
93 rc->rc_prog = program;
94 rc->rc_vers = version;
95 rc->rc_sendsz = sendsz;
96 rc->rc_recvsz = recvsz;
97 rc->rc_timeout.tv_sec = -1;
98 rc->rc_timeout.tv_usec = -1;
99 rc->rc_retry.tv_sec = 3;
100 rc->rc_retry.tv_usec = 0;
101 rc->rc_retries = INT_MAX;
102 rc->rc_privport = FALSE;
103 rc->rc_waitchan = "rpcrecv";
104 rc->rc_intr = 0;
105 rc->rc_connecting = FALSE;
106 rc->rc_closed = FALSE;
107 rc->rc_ucred = crdup(curthread->td_ucred);
108 rc->rc_client = NULL;
109
110 cl->cl_refs = 1;
111 cl->cl_ops = &clnt_reconnect_ops;
112 cl->cl_private = (caddr_t)(void *)rc;
113 cl->cl_auth = authnone_create();
114 cl->cl_tp = NULL;
115 cl->cl_netid = NULL;
116 return (cl);
117 }
118
119 static enum clnt_stat
120 clnt_reconnect_connect(CLIENT *cl)
121 {
122 struct thread *td = curthread;
123 struct rc_data *rc = (struct rc_data *)cl->cl_private;
124 struct socket *so;
125 enum clnt_stat stat;
126 int error;
127 int one = 1;
128 struct ucred *oldcred;
129 CLIENT *newclient = NULL;
130
131 mtx_lock(&rc->rc_lock);
132 while (rc->rc_connecting) {
133 error = msleep(rc, &rc->rc_lock,
134 rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
135 if (error) {
136 mtx_unlock(&rc->rc_lock);
137 return (RPC_INTR);
138 }
139 }
140 if (rc->rc_closed) {
141 mtx_unlock(&rc->rc_lock);
142 return (RPC_CANTSEND);
143 }
144 if (rc->rc_client) {
145 mtx_unlock(&rc->rc_lock);
146 return (RPC_SUCCESS);
147 }
148
149 /*
150 * My turn to attempt a connect. The rc_connecting variable
151 * serializes the following code sequence, so it is guaranteed
152 * that rc_client will still be NULL after it is re-locked below,
153 * since that is the only place it is set non-NULL.
154 */
155 rc->rc_connecting = TRUE;
156 mtx_unlock(&rc->rc_lock);
157
158 oldcred = td->td_ucred;
159 td->td_ucred = rc->rc_ucred;
160 so = __rpc_nconf2socket(rc->rc_nconf);
161 if (!so) {
162 stat = rpc_createerr.cf_stat = RPC_TLIERROR;
163 rpc_createerr.cf_error.re_errno = 0;
164 td->td_ucred = oldcred;
165 goto out;
166 }
167
168 if (rc->rc_privport)
169 bindresvport(so, NULL);
170
171 if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
172 newclient = clnt_dg_create(so,
173 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
174 rc->rc_sendsz, rc->rc_recvsz);
175 else
176 newclient = clnt_vc_create(so,
177 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
178 rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
179 td->td_ucred = oldcred;
180
181 if (!newclient) {
182 soclose(so);
183 rc->rc_err = rpc_createerr.cf_error;
184 stat = rpc_createerr.cf_stat;
185 goto out;
186 }
187
188 CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0);
189 CLNT_CONTROL(newclient, CLSET_CONNECT, &one);
190 CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout);
191 CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
192 CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan);
193 CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr);
194 if (rc->rc_backchannel != NULL)
195 CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel);
196 stat = RPC_SUCCESS;
197
198 out:
199 mtx_lock(&rc->rc_lock);
200 KASSERT(rc->rc_client == NULL, ("rc_client not null"));
201 if (!rc->rc_closed) {
202 rc->rc_client = newclient;
203 newclient = NULL;
204 }
205 rc->rc_connecting = FALSE;
206 wakeup(rc);
207 mtx_unlock(&rc->rc_lock);
208
209 if (newclient) {
210 /*
211 * It has been closed, so discard the new client.
212 * nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot
213 * be called with the rc_lock mutex held, since they may
214 * msleep() while holding a different mutex.
215 */
216 CLNT_CLOSE(newclient);
217 CLNT_RELEASE(newclient);
218 }
219
220 return (stat);
221 }
222
223 static enum clnt_stat
224 clnt_reconnect_call(
225 CLIENT *cl, /* client handle */
226 struct rpc_callextra *ext, /* call metadata */
227 rpcproc_t proc, /* procedure number */
228 struct mbuf *args, /* pointer to args */
229 struct mbuf **resultsp, /* pointer to results */
230 struct timeval utimeout)
231 {
232 struct rc_data *rc = (struct rc_data *)cl->cl_private;
233 CLIENT *client;
234 enum clnt_stat stat;
235 int tries, error;
236
237 tries = 0;
238 do {
239 mtx_lock(&rc->rc_lock);
240 if (rc->rc_closed) {
241 mtx_unlock(&rc->rc_lock);
242 return (RPC_CANTSEND);
243 }
244
245 if (!rc->rc_client) {
246 mtx_unlock(&rc->rc_lock);
247 stat = clnt_reconnect_connect(cl);
248 if (stat == RPC_SYSTEMERROR) {
249 error = tsleep(&fake_wchan,
250 rc->rc_intr ? PCATCH | PBDRY : 0, "rpccon",
251 hz);
252 if (error == EINTR || error == ERESTART)
253 return (RPC_INTR);
254 tries++;
255 if (tries >= rc->rc_retries)
256 return (stat);
257 continue;
258 }
259 if (stat != RPC_SUCCESS)
260 return (stat);
261 mtx_lock(&rc->rc_lock);
262 }
263
264 if (!rc->rc_client) {
265 mtx_unlock(&rc->rc_lock);
266 stat = RPC_FAILED;
267 continue;
268 }
269 CLNT_ACQUIRE(rc->rc_client);
270 client = rc->rc_client;
271 mtx_unlock(&rc->rc_lock);
272 stat = CLNT_CALL_MBUF(client, ext, proc, args,
273 resultsp, utimeout);
274
275 if (stat != RPC_SUCCESS) {
276 if (!ext)
277 CLNT_GETERR(client, &rc->rc_err);
278 }
279
280 if (stat == RPC_TIMEDOUT) {
281 /*
282 * Check for async send misfeature for NLM
283 * protocol.
284 */
285 if ((rc->rc_timeout.tv_sec == 0
286 && rc->rc_timeout.tv_usec == 0)
287 || (rc->rc_timeout.tv_sec == -1
288 && utimeout.tv_sec == 0
289 && utimeout.tv_usec == 0)) {
290 CLNT_RELEASE(client);
291 break;
292 }
293 }
294
295 if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
296 || stat == RPC_CANTRECV) {
297 tries++;
298 if (tries >= rc->rc_retries) {
299 CLNT_RELEASE(client);
300 break;
301 }
302
303 if (ext && ext->rc_feedback)
304 ext->rc_feedback(FEEDBACK_RECONNECT, proc,
305 ext->rc_feedback_arg);
306
307 mtx_lock(&rc->rc_lock);
308 /*
309 * Make sure that someone else hasn't already
310 * reconnected by checking if rc_client has changed.
311 * If not, we are done with the client and must
312 * do CLNT_RELEASE(client) twice to dispose of it,
313 * because there is both an initial refcnt and one
314 * acquired by CLNT_ACQUIRE() above.
315 */
316 if (rc->rc_client == client) {
317 rc->rc_client = NULL;
318 mtx_unlock(&rc->rc_lock);
319 CLNT_RELEASE(client);
320 } else {
321 mtx_unlock(&rc->rc_lock);
322 }
323 CLNT_RELEASE(client);
324 } else {
325 CLNT_RELEASE(client);
326 break;
327 }
328 } while (stat != RPC_SUCCESS);
329
330 KASSERT(stat != RPC_SUCCESS || *resultsp,
331 ("RPC_SUCCESS without reply"));
332
333 return (stat);
334 }
335
336 static void
337 clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp)
338 {
339 struct rc_data *rc = (struct rc_data *)cl->cl_private;
340
341 *errp = rc->rc_err;
342 }
343
344 /*
345 * Since this function requires that rc_client be valid, it can
346 * only be called when that is guaranteed to be the case.
347 */
348 static bool_t
349 clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
350 {
351 struct rc_data *rc = (struct rc_data *)cl->cl_private;
352
353 return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr));
354 }
355
356 /*ARGSUSED*/
357 static void
358 clnt_reconnect_abort(CLIENT *h)
359 {
360 }
361
362 /*
363 * CLNT_CONTROL() on the client returned by clnt_reconnect_create() must
364 * always be called before CLNT_CALL_MBUF() by a single thread only.
365 */
366 static bool_t
367 clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
368 {
369 struct rc_data *rc = (struct rc_data *)cl->cl_private;
370 SVCXPRT *xprt;
371
372 if (info == NULL) {
373 return (FALSE);
374 }
375 switch (request) {
376 case CLSET_TIMEOUT:
377 rc->rc_timeout = *(struct timeval *)info;
378 if (rc->rc_client)
379 CLNT_CONTROL(rc->rc_client, request, info);
380 break;
381
382 case CLGET_TIMEOUT:
383 *(struct timeval *)info = rc->rc_timeout;
384 break;
385
386 case CLSET_RETRY_TIMEOUT:
387 rc->rc_retry = *(struct timeval *)info;
388 if (rc->rc_client)
389 CLNT_CONTROL(rc->rc_client, request, info);
390 break;
391
392 case CLGET_RETRY_TIMEOUT:
393 *(struct timeval *)info = rc->rc_retry;
394 break;
395
396 case CLGET_VERS:
397 *(uint32_t *)info = rc->rc_vers;
398 break;
399
400 case CLSET_VERS:
401 rc->rc_vers = *(uint32_t *) info;
402 if (rc->rc_client)
403 CLNT_CONTROL(rc->rc_client, CLSET_VERS, info);
404 break;
405
406 case CLGET_PROG:
407 *(uint32_t *)info = rc->rc_prog;
408 break;
409
410 case CLSET_PROG:
411 rc->rc_prog = *(uint32_t *) info;
412 if (rc->rc_client)
413 CLNT_CONTROL(rc->rc_client, request, info);
414 break;
415
416 case CLSET_WAITCHAN:
417 rc->rc_waitchan = (char *)info;
418 if (rc->rc_client)
419 CLNT_CONTROL(rc->rc_client, request, info);
420 break;
421
422 case CLGET_WAITCHAN:
423 *(const char **) info = rc->rc_waitchan;
424 break;
425
426 case CLSET_INTERRUPTIBLE:
427 rc->rc_intr = *(int *) info;
428 if (rc->rc_client)
429 CLNT_CONTROL(rc->rc_client, request, info);
430 break;
431
432 case CLGET_INTERRUPTIBLE:
433 *(int *) info = rc->rc_intr;
434 break;
435
436 case CLSET_RETRIES:
437 rc->rc_retries = *(int *) info;
438 break;
439
440 case CLGET_RETRIES:
441 *(int *) info = rc->rc_retries;
442 break;
443
444 case CLSET_PRIVPORT:
445 rc->rc_privport = *(int *) info;
446 break;
447
448 case CLGET_PRIVPORT:
449 *(int *) info = rc->rc_privport;
450 break;
451
452 case CLSET_BACKCHANNEL:
453 xprt = (SVCXPRT *)info;
454 SVC_ACQUIRE(xprt);
455 xprt_register(xprt);
456 rc->rc_backchannel = info;
457 break;
458
459 default:
460 return (FALSE);
461 }
462
463 return (TRUE);
464 }
465
466 static void
467 clnt_reconnect_close(CLIENT *cl)
468 {
469 struct rc_data *rc = (struct rc_data *)cl->cl_private;
470 CLIENT *client;
471
472 mtx_lock(&rc->rc_lock);
473
474 if (rc->rc_closed) {
475 mtx_unlock(&rc->rc_lock);
476 return;
477 }
478
479 rc->rc_closed = TRUE;
480 client = rc->rc_client;
481 rc->rc_client = NULL;
482
483 mtx_unlock(&rc->rc_lock);
484
485 if (client) {
486 CLNT_CLOSE(client);
487 CLNT_RELEASE(client);
488 }
489 }
490
491 static void
492 clnt_reconnect_destroy(CLIENT *cl)
493 {
494 struct rc_data *rc = (struct rc_data *)cl->cl_private;
495 SVCXPRT *xprt;
496
497 if (rc->rc_client)
498 CLNT_DESTROY(rc->rc_client);
499 if (rc->rc_backchannel) {
500 xprt = (SVCXPRT *)rc->rc_backchannel;
501 xprt_unregister(xprt);
502 SVC_RELEASE(xprt);
503 }
504 crfree(rc->rc_ucred);
505 mtx_destroy(&rc->rc_lock);
506 mem_free(rc, sizeof(*rc));
507 mem_free(cl, sizeof (CLIENT));
508 }
Cache object: 821454db1a4eac2f5d1dcf9d4ab8a6c7
|