xref: /titanic_41/usr/src/lib/lvm/libmeta/common/metarpcopen.c (revision 18c2aff776a775d34a4c9893a4c72e0434d68e36)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Just in case we're not in a build environment, make sure that
31  * TEXT_DOMAIN gets set to something.
32  */
33 #if !defined(TEXT_DOMAIN)
34 #define	TEXT_DOMAIN "SYS_TEST"
35 #endif
36 
37 #include <meta.h>
38 #include <metad.h>
39 
40 #define	CC_TTL_MAX	20
41 
42 typedef struct {
43 	char		*cc_node;
44 	struct timeval	cc_ttl;
45 	CLIENT		*cc_clp;
46 } client_cache_t;
47 
48 typedef struct client_header {
49 	client_cache_t	**ch_cache;	/* array of clients. */
50 	mutex_t		ch_mutex;	/* lock access to ch_cache */
51 } client_header_t;
52 
53 /*
54  * This structure is used to pass data from meta_client_create to
55  * client_create_helper via meta_client_create_retry.
56  */
57 typedef struct clnt_data {
58 	rpcprog_t	cd_prognum;	/* RPC program number */
59 	rpcvers_t	cd_version;	/* Desired interface version */
60 	char		*cd_nettype;	/* Type of network to use */
61 } clnt_data_t;
62 
63 #define	MALLOC_BLK_SIZE	10
64 static client_header_t	client_header = {(client_cache_t **)NULL, DEFAULTMUTEX};
65 
66 static void
67 cc_add(
68 	client_header_t *header,
69 	char *node,
70 	CLIENT *clntp,
71 	md_error_t *ep
72 )
73 {
74 	client_cache_t ***cachep = &header->ch_cache;
75 	struct timeval	now;
76 	int		i;
77 	int		j = 0;
78 
79 	if (gettimeofday(&now, NULL) == -1) {
80 		(void) mdsyserror(ep, errno, "gettimeofday()");
81 		return;
82 	}
83 
84 	(void) mutex_lock(&header->ch_mutex);
85 	if (*cachep) {
86 		for (i = 0; (*cachep)[i] != NULL; i++)
87 			if (strcmp((*cachep)[i]->cc_node, node) == 0 &&
88 			    (*cachep)[i]->cc_clp == NULL) {
89 				(*cachep)[i]->cc_clp = clntp;
90 				(*cachep)[i]->cc_ttl = now;
91 				(void) mutex_unlock(&header->ch_mutex);
92 				return;
93 			}
94 	} else {
95 		*cachep = Calloc(MALLOC_BLK_SIZE, sizeof (**cachep));
96 		i = 0;
97 	}
98 
99 	(*cachep)[i] = Zalloc(sizeof (***cachep));
100 	(*cachep)[i]->cc_node = Strdup(node);
101 	(*cachep)[i]->cc_clp = clntp;
102 	(*cachep)[i]->cc_ttl = now;
103 
104 	if ((++i % MALLOC_BLK_SIZE) == 0) {
105 		*cachep = Realloc(*cachep,
106 		    (i + MALLOC_BLK_SIZE) * sizeof (**cachep));
107 		for (j = i; j < (i + MALLOC_BLK_SIZE); j++)
108 			(*cachep)[j] = NULL;
109 	}
110 	(void) mutex_unlock(&header->ch_mutex);
111 }
112 
113 static void
114 rel_clntp(client_cache_t *cachep)
115 {
116 	CLIENT		*clntp = cachep->cc_clp;
117 
118 	if (clntp != NULL) {
119 		auth_destroy(clntp->cl_auth);
120 		clnt_destroy(clntp);
121 	}
122 	cachep->cc_clp = NULL;
123 }
124 
125 static void
126 cc_destroy(client_header_t *header)
127 {
128 	client_cache_t ***cachep = &header->ch_cache;
129 	int	i;
130 
131 	(void) mutex_lock(&header->ch_mutex);
132 	if (*cachep) {
133 		for (i = 0; ((*cachep)[i] != NULL); i++) {
134 			client_cache_t	*p = (*cachep)[i];
135 
136 			Free(p->cc_node);
137 			rel_clntp(p);
138 			Free(p);
139 		}
140 		Free(*cachep);
141 		*cachep = NULL;
142 	}
143 	(void) mutex_unlock(&header->ch_mutex);
144 }
145 
146 /*
147  * Set the timeout value for this client handle.
148  */
149 static int
150 cl_sto(
151 	CLIENT		*clntp,
152 	char		*hostname,
153 	long		time_out,
154 	md_error_t	*ep
155 )
156 {
157 	struct timeval	nto;
158 
159 	(void) memset(&nto, '\0', sizeof (nto));
160 
161 	nto.tv_sec = time_out;
162 
163 	if (clnt_control(clntp, CLSET_TIMEOUT, (char *)&nto) != TRUE)
164 		return (mdrpcerror(ep, clntp, hostname,
165 		    dgettext(TEXT_DOMAIN, "metad client set timeout")));
166 
167 	return (0);
168 }
169 
170 /*
171  * client_create_vers_retry is the helper function to be passed to
172  * meta_client_create_retry to do the actual work of creating the client
173  * when version selection is necessary.
174  */
175 
176 /* ARGSUSED */
177 static CLIENT *
178 client_create_vers_retry(char *hostname,
179 	void *ignore,
180 	struct timeval *tout
181 )
182 {
183 	rpcvers_t	vers;		/* Version # not needed. */
184 
185 	return (clnt_create_vers_timed(hostname, METAD, &vers,
186 		METAD_VERSION, METAD_VERSION_DEVID, "tcp", tout));
187 }
188 
189 /*
190  * client_create_helper is the helper function to be passed to
191  * meta_client_create_retry when plain vanilla client create is desired.
192  */
193 static CLIENT *
194 client_create_helper(char *hostname, void *private, struct timeval *time_out)
195 {
196 	clnt_data_t	*cd = (clnt_data_t *)private;
197 
198 	return (clnt_create_timed(hostname, cd->cd_prognum, cd->cd_version,
199 		cd->cd_nettype, time_out));
200 }
201 
202 /*
203  * meta_client_create_retry is a general function to assist in creating RPC
204  * clients.  This function handles retrying if the attempt to create a
205  * client fails.  meta_client_create_retry itself does not actually create
206  * the client.  Instead it calls the helper function, func, to do that job.
207  *
208  * With the help of func, meta_client_create_retry will create an RPC
209  * connection allowing up to tout seconds to complete the task.  If the
210  * connection creation fails for RPC_RPCBFAILURE, RPC_CANTRECV or
211  * RPC_PROGNOTREGISTERED and tout seconds have not passed,
212  * meta_client_create_retry will try again.  The reason retries are
213  * important is that when the inet daemon is being refreshed, it can take
214  * 15-20 seconds for it to start responding again.
215  *
216  * Arguments:
217  *
218  *	hostname	- Name of remote host
219  *
220  *	func		- Pointer to the helper function, that will
221  *			  actually try to create the client.
222  *
223  *	data		- Private data to be passed on to func.
224  *			  meta_client_create_retry treats this as an opaque
225  *			  pointer.
226  *
227  *	tout		- Number of seconds to allow for the connection
228  *			  attempt.
229  *
230  *	ep		- Standard SVM error pointer.  May be NULL.
231  */
232 CLIENT *
233 meta_client_create_retry(
234 	char			*hostname,
235 	clnt_create_func_t	func,
236 	void			*data,
237 	time_t			tout,
238 	md_error_t		*ep
239 )
240 {
241 	static int		debug;		/* print debugging info */
242 	static int		debug_set = 0;
243 
244 	CLIENT			*clnt = (CLIENT *) NULL;
245 	struct timeval		curtime;
246 	char			*d;
247 	struct timeval		start;
248 	struct timeval		timeout;
249 
250 	if (debug_set == 0) {
251 		d = getenv("MD_DEBUG");
252 		if (d == NULL) {
253 			debug = 0;
254 		} else {
255 			debug = (strstr(d, "RPC") == NULL) ? 0 : 1;
256 		}
257 		debug_set = 1;
258 	}
259 	timeout.tv_usec = 0;
260 	if (gettimeofday(&start, NULL) == -1) {
261 		if (ep != (md_error_t *)NULL) {
262 			(void) mdsyserror(ep, errno, "gettimeofday()");
263 		}
264 		return (clnt);
265 	}
266 	curtime = start;
267 	while ((curtime.tv_sec - start.tv_sec) < tout) {
268 		/* Use remaining time as the timeout value. */
269 		timeout.tv_sec = tout - (curtime.tv_sec - start.tv_sec);
270 		clnt = (*func)(hostname, data, &timeout);
271 		if (clnt != (CLIENT *) NULL)
272 			break;
273 		if ((rpc_createerr.cf_stat == RPC_RPCBFAILURE) ||
274 			(rpc_createerr.cf_stat == RPC_PROGNOTREGISTERED) ||
275 			(rpc_createerr.cf_stat == RPC_CANTRECV)) {
276 			if (debug) {
277 				clnt_pcreateerror("meta_client_create_retry");
278 			}
279 			/* If error might be fixed in time, sleep & try again */
280 			(void) sleep(2);
281 			if (gettimeofday(&curtime, NULL) == -1) {
282 				if (ep != (md_error_t *)NULL) {
283 					(void) mdsyserror(ep, errno,
284 						"gettimeofday()");
285 				}
286 				return (clnt);
287 			}
288 		} else {
289 			/* Not a recoverable error. */
290 			break;
291 		}
292 	}
293 	if ((clnt == (CLIENT *) NULL) && (ep != (md_error_t *)NULL)) {
294 		(void) mdrpccreateerror(ep, hostname,
295 			"meta_client_create_retry");
296 	}
297 	return (clnt);
298 }
299 
300 /*
301  * meta_client_create is intended to be used within SVM as a replacement
302  * for calls to clnt_create.  meta_client_create invokes the retry
303  * mechanism of meta_client_create_retry.
304  */
305 CLIENT *
306 meta_client_create(char *host, rpcprog_t prognum, rpcvers_t version,
307 	char *nettype)
308 {
309 	clnt_data_t		cd;
310 
311 	cd.cd_prognum = prognum;
312 	cd.cd_version = version;
313 	cd.cd_nettype = nettype;
314 	return (meta_client_create_retry(host, client_create_helper,
315 		(void *)&cd, MD_CLNT_CREATE_TOUT, (md_error_t *)NULL));
316 }
317 
318 /*
319  * create and return RPC connection
320  */
321 CLIENT *
322 metarpcopen(
323 	char		*hostname,
324 	long		time_out,
325 	md_error_t	*ep
326 )
327 {
328 	CLIENT		*clntp = NULL;
329 	client_cache_t	***cachep = &client_header.ch_cache;
330 	int		i;
331 	long		delta;
332 	struct timeval	now;
333 
334 	if (gettimeofday(&now, NULL) == -1) {
335 		(void) mdsyserror(ep, errno, "gettimeofday()");
336 		return (NULL);
337 	}
338 
339 	/*
340 	 * Before trying to create the client, make sure that the core SVM
341 	 * services are enabled by the Service Management Facility.  We
342 	 * don't want to suffer the 60 second timeout if the services are
343 	 * not even enabled.  This call actually only verifies that they
344 	 * are enabled on this host no matter which host the caller wants
345 	 * to connect to.  Nonetheless, if the services are not enabled on
346 	 * the local host, our RPC stuff is not going to work as expected.
347 	 */
348 	if (meta_smf_isonline(META_SMF_CORE, ep) == 0) {
349 		return (NULL);
350 	}
351 
352 	(void) mutex_lock(&client_header.ch_mutex);
353 	if (client_header.ch_cache) {
354 		for (i = 0; (*cachep)[i] != NULL; i++) {
355 			if (strcmp((*cachep)[i]->cc_node, hostname) == 0) {
356 				clntp = (*cachep)[i]->cc_clp;
357 				if (clntp == NULL)
358 					continue;
359 				delta = now.tv_sec -
360 				    (*cachep)[i]->cc_ttl.tv_sec;
361 				if (delta > CC_TTL_MAX) {
362 					rel_clntp((*cachep)[i]);
363 					continue;
364 				}
365 				if (cl_sto(clntp, hostname, time_out,
366 					ep) != 0) {
367 					(void) mutex_unlock(
368 						&client_header.ch_mutex);
369 					return (NULL);
370 				}
371 				(void) mutex_unlock(&client_header.ch_mutex);
372 				return (clntp);
373 			}
374 		}
375 	}
376 	(void) mutex_unlock(&client_header.ch_mutex);
377 
378 	/*
379 	 * Try to create a version 2 client handle by default.
380 	 * If this fails (i.e. client is version 1), try to
381 	 * create a version 1 client handle.
382 	 */
383 	clntp = meta_client_create_retry(hostname, client_create_vers_retry,
384 		(void *)NULL, MD_CLNT_CREATE_TOUT, ep);
385 
386 	/* open connection */
387 	if (clntp == NULL) {
388 		(void) mdrpccreateerror(ep, hostname,
389 		    dgettext(TEXT_DOMAIN, "metad client create"));
390 		cc_add(&client_header, hostname, NULL, ep);
391 		return (NULL);
392 	} else {
393 		auth_destroy(clntp->cl_auth);
394 		clntp->cl_auth = authsys_create_default();
395 		assert(clntp->cl_auth != NULL);
396 	}
397 
398 	cc_add(&client_header, hostname, clntp, ep);
399 
400 	if (cl_sto(clntp, hostname, time_out, ep) != 0)
401 		return (NULL);
402 
403 	return (clntp);
404 }
405 
406 /*
407  * metarpcclose - is a place holder so that when using
408  *		  metarpcopen, it does not appear that
409  *		  we have dangling opens.  We can at some
410  *		  later decrement open counts here too, if needed.
411  */
412 /*ARGSUSED*/
413 void
414 metarpcclose(CLIENT *clntp)
415 {
416 }
417 
418 void
419 metarpccloseall(void)
420 {
421 	cc_destroy(&client_header);
422 }
423