1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ 5 * Authors: Doug Rabson <dfr@rabson.org> 6 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/mbuf.h> 40 #include <sys/mutex.h> 41 #include <sys/pcpu.h> 42 #include <sys/proc.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/time.h> 46 #include <sys/uio.h> 47 48 #include <rpc/rpc.h> 49 #include <rpc/rpc_com.h> 50 #include <rpc/krpc.h> 51 52 static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *, 53 rpcproc_t, struct mbuf *, struct mbuf **, struct timeval); 54 static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *); 55 static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *); 56 static void clnt_reconnect_abort(CLIENT *); 57 static bool_t clnt_reconnect_control(CLIENT *, u_int, void *); 58 static void clnt_reconnect_close(CLIENT *); 59 static void clnt_reconnect_destroy(CLIENT *); 60 61 static struct clnt_ops clnt_reconnect_ops = { 62 .cl_call = clnt_reconnect_call, 63 .cl_abort = clnt_reconnect_abort, 64 .cl_geterr = clnt_reconnect_geterr, 65 .cl_freeres = clnt_reconnect_freeres, 66 .cl_close = clnt_reconnect_close, 67 .cl_destroy = clnt_reconnect_destroy, 68 .cl_control = clnt_reconnect_control 69 }; 70 71 static int fake_wchan; 72 73 CLIENT * 74 clnt_reconnect_create( 75 struct netconfig *nconf, /* network type */ 76 struct sockaddr *svcaddr, /* servers address */ 77 rpcprog_t program, /* program number */ 78 rpcvers_t version, /* version number */ 79 size_t sendsz, /* buffer recv size */ 80 size_t recvsz) /* buffer send size */ 81 { 82 CLIENT *cl = NULL; /* client handle */ 83 struct rc_data *rc = NULL; /* private data */ 84 85 if (svcaddr == NULL) { 86 rpc_createerr.cf_stat = RPC_UNKNOWNADDR; 87 return (NULL); 88 } 89 90 cl = mem_alloc(sizeof (CLIENT)); 91 rc = mem_alloc(sizeof (*rc)); 92 mtx_init(&rc->rc_lock, "rc->rc_lock", NULL, MTX_DEF); 93 (void) memcpy(&rc->rc_addr, svcaddr, (size_t)svcaddr->sa_len); 94 rc->rc_nconf = nconf; 95 rc->rc_prog = program; 96 rc->rc_vers = version; 97 rc->rc_sendsz = sendsz; 98 rc->rc_recvsz = recvsz; 99 rc->rc_timeout.tv_sec = -1; 100 rc->rc_timeout.tv_usec = -1; 101 rc->rc_retry.tv_sec = 3; 102 rc->rc_retry.tv_usec = 0; 103 rc->rc_retries = INT_MAX; 104 rc->rc_privport = FALSE; 105 rc->rc_waitchan = "rpcrecv"; 106 rc->rc_intr = 0; 107 rc->rc_connecting = FALSE; 108 rc->rc_closed = FALSE; 109 rc->rc_ucred = crdup(curthread->td_ucred); 110 rc->rc_client = NULL; 111 112 cl->cl_refs = 1; 113 cl->cl_ops = &clnt_reconnect_ops; 114 cl->cl_private = (caddr_t)(void *)rc; 115 cl->cl_auth = authnone_create(); 116 cl->cl_tp = NULL; 117 cl->cl_netid = NULL; 118 return (cl); 119 } 120 121 static enum clnt_stat 122 clnt_reconnect_connect(CLIENT *cl) 123 { 124 struct thread *td = curthread; 125 struct rc_data *rc = (struct rc_data *)cl->cl_private; 126 struct socket *so; 127 enum clnt_stat stat; 128 int error; 129 int one = 1; 130 struct ucred *oldcred; 131 CLIENT *newclient = NULL; 132 133 mtx_lock(&rc->rc_lock); 134 while (rc->rc_connecting) { 135 error = msleep(rc, &rc->rc_lock, 136 rc->rc_intr ? PCATCH : 0, "rpcrecon", 0); 137 if (error) { 138 mtx_unlock(&rc->rc_lock); 139 return (RPC_INTR); 140 } 141 } 142 if (rc->rc_closed) { 143 mtx_unlock(&rc->rc_lock); 144 return (RPC_CANTSEND); 145 } 146 if (rc->rc_client) { 147 mtx_unlock(&rc->rc_lock); 148 return (RPC_SUCCESS); 149 } 150 151 /* 152 * My turn to attempt a connect. The rc_connecting variable 153 * serializes the following code sequence, so it is guaranteed 154 * that rc_client will still be NULL after it is re-locked below, 155 * since that is the only place it is set non-NULL. 156 */ 157 rc->rc_connecting = TRUE; 158 mtx_unlock(&rc->rc_lock); 159 160 oldcred = td->td_ucred; 161 td->td_ucred = rc->rc_ucred; 162 so = __rpc_nconf2socket(rc->rc_nconf); 163 if (!so) { 164 stat = rpc_createerr.cf_stat = RPC_TLIERROR; 165 rpc_createerr.cf_error.re_errno = 0; 166 td->td_ucred = oldcred; 167 goto out; 168 } 169 170 if (rc->rc_privport) 171 bindresvport(so, NULL); 172 173 if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS) 174 newclient = clnt_dg_create(so, 175 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers, 176 rc->rc_sendsz, rc->rc_recvsz); 177 else 178 newclient = clnt_vc_create(so, 179 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers, 180 rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr); 181 td->td_ucred = oldcred; 182 183 if (!newclient) { 184 soclose(so); 185 rc->rc_err = rpc_createerr.cf_error; 186 stat = rpc_createerr.cf_stat; 187 goto out; 188 } 189 190 CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0); 191 CLNT_CONTROL(newclient, CLSET_CONNECT, &one); 192 CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout); 193 CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry); 194 CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan); 195 CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr); 196 if (rc->rc_backchannel != NULL) 197 CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel); 198 stat = RPC_SUCCESS; 199 200 out: 201 mtx_lock(&rc->rc_lock); 202 KASSERT(rc->rc_client == NULL, ("rc_client not null")); 203 if (!rc->rc_closed) { 204 rc->rc_client = newclient; 205 newclient = NULL; 206 } 207 rc->rc_connecting = FALSE; 208 wakeup(rc); 209 mtx_unlock(&rc->rc_lock); 210 211 if (newclient) { 212 /* 213 * It has been closed, so discard the new client. 214 * nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot 215 * be called with the rc_lock mutex held, since they may 216 * msleep() while holding a different mutex. 217 */ 218 CLNT_CLOSE(newclient); 219 CLNT_RELEASE(newclient); 220 } 221 222 return (stat); 223 } 224 225 static enum clnt_stat 226 clnt_reconnect_call( 227 CLIENT *cl, /* client handle */ 228 struct rpc_callextra *ext, /* call metadata */ 229 rpcproc_t proc, /* procedure number */ 230 struct mbuf *args, /* pointer to args */ 231 struct mbuf **resultsp, /* pointer to results */ 232 struct timeval utimeout) 233 { 234 struct rc_data *rc = (struct rc_data *)cl->cl_private; 235 CLIENT *client; 236 enum clnt_stat stat; 237 int tries, error; 238 239 tries = 0; 240 do { 241 mtx_lock(&rc->rc_lock); 242 if (rc->rc_closed) { 243 mtx_unlock(&rc->rc_lock); 244 return (RPC_CANTSEND); 245 } 246 247 if (!rc->rc_client) { 248 mtx_unlock(&rc->rc_lock); 249 stat = clnt_reconnect_connect(cl); 250 if (stat == RPC_SYSTEMERROR) { 251 error = tsleep(&fake_wchan, 252 rc->rc_intr ? PCATCH : 0, "rpccon", hz); 253 if (error == EINTR || error == ERESTART) 254 return (RPC_INTR); 255 tries++; 256 if (tries >= rc->rc_retries) 257 return (stat); 258 continue; 259 } 260 if (stat != RPC_SUCCESS) 261 return (stat); 262 mtx_lock(&rc->rc_lock); 263 } 264 265 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 if (stat == RPC_TIMEDOUT) { 282 /* 283 * Check for async send misfeature for NLM 284 * protocol. 285 */ 286 if ((rc->rc_timeout.tv_sec == 0 287 && rc->rc_timeout.tv_usec == 0) 288 || (rc->rc_timeout.tv_sec == -1 289 && utimeout.tv_sec == 0 290 && utimeout.tv_usec == 0)) { 291 CLNT_RELEASE(client); 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 CLNT_RELEASE(client); 301 break; 302 } 303 304 if (ext && ext->rc_feedback) 305 ext->rc_feedback(FEEDBACK_RECONNECT, proc, 306 ext->rc_feedback_arg); 307 308 mtx_lock(&rc->rc_lock); 309 /* 310 * Make sure that someone else hasn't already 311 * reconnected by checking if rc_client has changed. 312 * If not, we are done with the client and must 313 * do CLNT_RELEASE(client) twice to dispose of it, 314 * because there is both an initial refcnt and one 315 * acquired by CLNT_ACQUIRE() above. 316 */ 317 if (rc->rc_client == client) { 318 rc->rc_client = NULL; 319 mtx_unlock(&rc->rc_lock); 320 CLNT_RELEASE(client); 321 } else { 322 mtx_unlock(&rc->rc_lock); 323 } 324 CLNT_RELEASE(client); 325 } else { 326 CLNT_RELEASE(client); 327 break; 328 } 329 } while (stat != RPC_SUCCESS); 330 331 KASSERT(stat != RPC_SUCCESS || *resultsp, 332 ("RPC_SUCCESS without reply")); 333 334 return (stat); 335 } 336 337 static void 338 clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp) 339 { 340 struct rc_data *rc = (struct rc_data *)cl->cl_private; 341 342 *errp = rc->rc_err; 343 } 344 345 /* 346 * Since this function requires that rc_client be valid, it can 347 * only be called when that is guaranteed to be the case. 348 */ 349 static bool_t 350 clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr) 351 { 352 struct rc_data *rc = (struct rc_data *)cl->cl_private; 353 354 return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr)); 355 } 356 357 /*ARGSUSED*/ 358 static void 359 clnt_reconnect_abort(CLIENT *h) 360 { 361 } 362 363 /* 364 * CLNT_CONTROL() on the client returned by clnt_reconnect_create() must 365 * always be called before CLNT_CALL_MBUF() by a single thread only. 366 */ 367 static bool_t 368 clnt_reconnect_control(CLIENT *cl, u_int request, void *info) 369 { 370 struct rc_data *rc = (struct rc_data *)cl->cl_private; 371 SVCXPRT *xprt; 372 373 if (info == NULL) { 374 return (FALSE); 375 } 376 switch (request) { 377 case CLSET_TIMEOUT: 378 rc->rc_timeout = *(struct timeval *)info; 379 if (rc->rc_client) 380 CLNT_CONTROL(rc->rc_client, request, info); 381 break; 382 383 case CLGET_TIMEOUT: 384 *(struct timeval *)info = rc->rc_timeout; 385 break; 386 387 case CLSET_RETRY_TIMEOUT: 388 rc->rc_retry = *(struct timeval *)info; 389 if (rc->rc_client) 390 CLNT_CONTROL(rc->rc_client, request, info); 391 break; 392 393 case CLGET_RETRY_TIMEOUT: 394 *(struct timeval *)info = rc->rc_retry; 395 break; 396 397 case CLGET_VERS: 398 *(uint32_t *)info = rc->rc_vers; 399 break; 400 401 case CLSET_VERS: 402 rc->rc_vers = *(uint32_t *) info; 403 if (rc->rc_client) 404 CLNT_CONTROL(rc->rc_client, CLSET_VERS, info); 405 break; 406 407 case CLGET_PROG: 408 *(uint32_t *)info = rc->rc_prog; 409 break; 410 411 case CLSET_PROG: 412 rc->rc_prog = *(uint32_t *) info; 413 if (rc->rc_client) 414 CLNT_CONTROL(rc->rc_client, request, info); 415 break; 416 417 case CLSET_WAITCHAN: 418 rc->rc_waitchan = (char *)info; 419 if (rc->rc_client) 420 CLNT_CONTROL(rc->rc_client, request, info); 421 break; 422 423 case CLGET_WAITCHAN: 424 *(const char **) info = rc->rc_waitchan; 425 break; 426 427 case CLSET_INTERRUPTIBLE: 428 rc->rc_intr = *(int *) info; 429 if (rc->rc_client) 430 CLNT_CONTROL(rc->rc_client, request, info); 431 break; 432 433 case CLGET_INTERRUPTIBLE: 434 *(int *) info = rc->rc_intr; 435 break; 436 437 case CLSET_RETRIES: 438 rc->rc_retries = *(int *) info; 439 break; 440 441 case CLGET_RETRIES: 442 *(int *) info = rc->rc_retries; 443 break; 444 445 case CLSET_PRIVPORT: 446 rc->rc_privport = *(int *) info; 447 break; 448 449 case CLGET_PRIVPORT: 450 *(int *) info = rc->rc_privport; 451 break; 452 453 case CLSET_BACKCHANNEL: 454 xprt = (SVCXPRT *)info; 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 } 509