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 52static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *, 53 rpcproc_t, struct mbuf *, struct mbuf **, struct timeval); 54static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *); 55static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *); 56static void clnt_reconnect_abort(CLIENT *); 57static bool_t clnt_reconnect_control(CLIENT *, u_int, void *); 58static void clnt_reconnect_close(CLIENT *); 59static void clnt_reconnect_destroy(CLIENT *); 60 61static 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 71static int fake_wchan; 72 73CLIENT * 74clnt_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 rc->rc_reconcall = NULL; 112 rc->rc_reconarg = NULL; 113 114 cl->cl_refs = 1; 115 cl->cl_ops = &clnt_reconnect_ops; 116 cl->cl_private = (caddr_t)(void *)rc; 117 cl->cl_auth = authnone_create(); 118 cl->cl_tp = NULL; 119 cl->cl_netid = NULL; 120 return (cl); 121} 122 123static enum clnt_stat 124clnt_reconnect_connect(CLIENT *cl) 125{ 126 struct thread *td = curthread; 127 struct rc_data *rc = (struct rc_data *)cl->cl_private; 128 struct socket *so; 129 enum clnt_stat stat; 130 int error; 131 int one = 1; 132 struct ucred *oldcred; 133 CLIENT *newclient = NULL; 134 135 mtx_lock(&rc->rc_lock); 136 while (rc->rc_connecting) { 137 error = msleep(rc, &rc->rc_lock, 138 rc->rc_intr ? PCATCH : 0, "rpcrecon", 0); 139 if (error) { 140 mtx_unlock(&rc->rc_lock); 141 return (RPC_INTR); 142 } 143 } 144 if (rc->rc_closed) { 145 mtx_unlock(&rc->rc_lock); 146 return (RPC_CANTSEND); 147 } 148 if (rc->rc_client) { 149 mtx_unlock(&rc->rc_lock); 150 return (RPC_SUCCESS); 151 } 152 153 /* 154 * My turn to attempt a connect. The rc_connecting variable 155 * serializes the following code sequence, so it is guaranteed 156 * that rc_client will still be NULL after it is re-locked below, 157 * since that is the only place it is set non-NULL. 158 */ 159 rc->rc_connecting = TRUE; 160 mtx_unlock(&rc->rc_lock); 161 162 oldcred = td->td_ucred; 163 td->td_ucred = rc->rc_ucred; 164 so = __rpc_nconf2socket(rc->rc_nconf); 165 if (!so) { 166 stat = rpc_createerr.cf_stat = RPC_TLIERROR; 167 rpc_createerr.cf_error.re_errno = 0; 168 td->td_ucred = oldcred; 169 goto out; 170 } 171 172 if (rc->rc_privport) 173 bindresvport(so, NULL); 174 175 if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS) 176 newclient = clnt_dg_create(so, 177 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers, 178 rc->rc_sendsz, rc->rc_recvsz); 179 else { 180 /* 181 * I do not believe a timeout of less than 1sec would make 182 * sense here since short delays can occur when a server is 183 * temporarily overloaded. 184 */ 185 if (rc->rc_timeout.tv_sec > 0 && rc->rc_timeout.tv_usec >= 0) { 186 error = so_setsockopt(so, SOL_SOCKET, SO_SNDTIMEO, 187 &rc->rc_timeout, sizeof(struct timeval)); 188 if (error != 0) { 189 stat = rpc_createerr.cf_stat = RPC_CANTSEND; 190 rpc_createerr.cf_error.re_errno = error; 191 td->td_ucred = oldcred; 192 goto out; 193 } 194 } 195 newclient = clnt_vc_create(so, 196 (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers, 197 rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr); 198 if (newclient != NULL && rc->rc_reconcall != NULL) 199 (*rc->rc_reconcall)(newclient, rc->rc_reconarg, 200 rc->rc_ucred); 201 } 202 td->td_ucred = oldcred; 203 204 if (!newclient) { 205 soclose(so); 206 rc->rc_err = rpc_createerr.cf_error; 207 stat = rpc_createerr.cf_stat; 208 goto out; 209 } 210 211 CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0); 212 CLNT_CONTROL(newclient, CLSET_CONNECT, &one); 213 CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout); 214 CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry); 215 CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan); 216 CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr); 217 if (rc->rc_backchannel != NULL) 218 CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel); 219 stat = RPC_SUCCESS; 220 221out: 222 mtx_lock(&rc->rc_lock); 223 KASSERT(rc->rc_client == NULL, ("rc_client not null")); 224 if (!rc->rc_closed) { 225 rc->rc_client = newclient; 226 newclient = NULL; 227 } 228 rc->rc_connecting = FALSE; 229 wakeup(rc); 230 mtx_unlock(&rc->rc_lock); 231 232 if (newclient) { 233 /* 234 * It has been closed, so discard the new client. 235 * nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot 236 * be called with the rc_lock mutex held, since they may 237 * msleep() while holding a different mutex. 238 */ 239 CLNT_CLOSE(newclient); 240 CLNT_RELEASE(newclient); 241 } 242 243 return (stat); 244} 245 246static enum clnt_stat 247clnt_reconnect_call( 248 CLIENT *cl, /* client handle */ 249 struct rpc_callextra *ext, /* call metadata */ 250 rpcproc_t proc, /* procedure number */ 251 struct mbuf *args, /* pointer to args */ 252 struct mbuf **resultsp, /* pointer to results */ 253 struct timeval utimeout) 254{ 255 struct rc_data *rc = (struct rc_data *)cl->cl_private; 256 CLIENT *client; 257 enum clnt_stat stat; 258 int tries, error; 259 260 tries = 0; 261 do { 262 mtx_lock(&rc->rc_lock); 263 if (rc->rc_closed) { 264 mtx_unlock(&rc->rc_lock); 265 return (RPC_CANTSEND); 266 } 267 268 if (!rc->rc_client) { 269 mtx_unlock(&rc->rc_lock); 270 stat = clnt_reconnect_connect(cl); 271 if (stat == RPC_SYSTEMERROR) { 272 error = tsleep(&fake_wchan, 273 rc->rc_intr ? PCATCH : 0, "rpccon", hz); 274 if (error == EINTR || error == ERESTART) 275 return (RPC_INTR); 276 tries++; 277 if (tries >= rc->rc_retries) 278 return (stat); 279 continue; 280 } 281 if (stat != RPC_SUCCESS) 282 return (stat); 283 mtx_lock(&rc->rc_lock); 284 } 285 286 if (!rc->rc_client) { 287 mtx_unlock(&rc->rc_lock); 288 stat = RPC_FAILED; 289 continue; 290 } 291 CLNT_ACQUIRE(rc->rc_client); 292 client = rc->rc_client; 293 mtx_unlock(&rc->rc_lock); 294 stat = CLNT_CALL_MBUF(client, ext, proc, args, 295 resultsp, utimeout); 296 297 if (stat != RPC_SUCCESS) { 298 if (!ext) 299 CLNT_GETERR(client, &rc->rc_err); 300 } 301 302 if (stat == RPC_TIMEDOUT) { 303 /* 304 * Check for async send misfeature for NLM 305 * protocol. 306 */ 307 if ((rc->rc_timeout.tv_sec == 0 308 && rc->rc_timeout.tv_usec == 0) 309 || (rc->rc_timeout.tv_sec == -1 310 && utimeout.tv_sec == 0 311 && utimeout.tv_usec == 0)) { 312 CLNT_RELEASE(client); 313 break; 314 } 315 } 316 317 if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND 318 || stat == RPC_CANTRECV) { 319 tries++; 320 if (tries >= rc->rc_retries) { 321 CLNT_RELEASE(client); 322 break; 323 } 324 325 if (ext && ext->rc_feedback) 326 ext->rc_feedback(FEEDBACK_RECONNECT, proc, 327 ext->rc_feedback_arg); 328 329 mtx_lock(&rc->rc_lock); 330 /* 331 * Make sure that someone else hasn't already 332 * reconnected by checking if rc_client has changed. 333 * If not, we are done with the client and must 334 * do CLNT_RELEASE(client) twice to dispose of it, 335 * because there is both an initial refcnt and one 336 * acquired by CLNT_ACQUIRE() above. 337 */ 338 if (rc->rc_client == client) { 339 rc->rc_client = NULL; 340 mtx_unlock(&rc->rc_lock); 341 CLNT_RELEASE(client); 342 } else { 343 mtx_unlock(&rc->rc_lock); 344 } 345 CLNT_RELEASE(client); 346 } else { 347 CLNT_RELEASE(client); 348 break; 349 } 350 } while (stat != RPC_SUCCESS); 351 352 KASSERT(stat != RPC_SUCCESS || *resultsp, 353 ("RPC_SUCCESS without reply")); 354 355 return (stat); 356} 357 358static void 359clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp) 360{ 361 struct rc_data *rc = (struct rc_data *)cl->cl_private; 362 363 *errp = rc->rc_err; 364} 365 366/* 367 * Since this function requires that rc_client be valid, it can 368 * only be called when that is guaranteed to be the case. 369 */ 370static bool_t 371clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr) 372{ 373 struct rc_data *rc = (struct rc_data *)cl->cl_private; 374 375 return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr)); 376} 377 378/*ARGSUSED*/ 379static void 380clnt_reconnect_abort(CLIENT *h) 381{ 382} 383 384/* 385 * CLNT_CONTROL() on the client returned by clnt_reconnect_create() must 386 * always be called before CLNT_CALL_MBUF() by a single thread only. 387 */ 388static bool_t 389clnt_reconnect_control(CLIENT *cl, u_int request, void *info) 390{ 391 struct rc_data *rc = (struct rc_data *)cl->cl_private; 392 SVCXPRT *xprt; 393 struct rpc_reconupcall *upcp; 394 395 if (info == NULL) { 396 return (FALSE); 397 } 398 switch (request) { 399 case CLSET_TIMEOUT: 400 rc->rc_timeout = *(struct timeval *)info; 401 if (rc->rc_client) 402 CLNT_CONTROL(rc->rc_client, request, info); 403 break; 404 405 case CLGET_TIMEOUT: 406 *(struct timeval *)info = rc->rc_timeout; 407 break; 408 409 case CLSET_RETRY_TIMEOUT: 410 rc->rc_retry = *(struct timeval *)info; 411 if (rc->rc_client) 412 CLNT_CONTROL(rc->rc_client, request, info); 413 break; 414 415 case CLGET_RETRY_TIMEOUT: 416 *(struct timeval *)info = rc->rc_retry; 417 break; 418 419 case CLGET_VERS: 420 *(uint32_t *)info = rc->rc_vers; 421 break; 422 423 case CLSET_VERS: 424 rc->rc_vers = *(uint32_t *) info; 425 if (rc->rc_client) 426 CLNT_CONTROL(rc->rc_client, CLSET_VERS, info); 427 break; 428 429 case CLGET_PROG: 430 *(uint32_t *)info = rc->rc_prog; 431 break; 432 433 case CLSET_PROG: 434 rc->rc_prog = *(uint32_t *) info; 435 if (rc->rc_client) 436 CLNT_CONTROL(rc->rc_client, request, info); 437 break; 438 439 case CLSET_WAITCHAN: 440 rc->rc_waitchan = (char *)info; 441 if (rc->rc_client) 442 CLNT_CONTROL(rc->rc_client, request, info); 443 break; 444 445 case CLGET_WAITCHAN: 446 *(const char **) info = rc->rc_waitchan; 447 break; 448 449 case CLSET_INTERRUPTIBLE: 450 rc->rc_intr = *(int *) info; 451 if (rc->rc_client) 452 CLNT_CONTROL(rc->rc_client, request, info); 453 break; 454 455 case CLGET_INTERRUPTIBLE: 456 *(int *) info = rc->rc_intr; 457 break; 458 459 case CLSET_RETRIES: 460 rc->rc_retries = *(int *) info; 461 break; 462 463 case CLGET_RETRIES: 464 *(int *) info = rc->rc_retries; 465 break; 466 467 case CLSET_PRIVPORT: 468 rc->rc_privport = *(int *) info; 469 break; 470 471 case CLGET_PRIVPORT: 472 *(int *) info = rc->rc_privport; 473 break; 474 475 case CLSET_BACKCHANNEL: 476 xprt = (SVCXPRT *)info; 477 xprt_register(xprt); 478 rc->rc_backchannel = info; 479 break; 480 481 case CLSET_RECONUPCALL: 482 upcp = (struct rpc_reconupcall *)info; 483 rc->rc_reconcall = upcp->call; 484 rc->rc_reconarg = upcp->arg; 485 break; 486 487 default: 488 return (FALSE); 489 } 490 491 return (TRUE); 492} 493 494static void 495clnt_reconnect_close(CLIENT *cl) 496{ 497 struct rc_data *rc = (struct rc_data *)cl->cl_private; 498 CLIENT *client; 499 500 mtx_lock(&rc->rc_lock); 501 502 if (rc->rc_closed) { 503 mtx_unlock(&rc->rc_lock); 504 return; 505 } 506 507 rc->rc_closed = TRUE; 508 client = rc->rc_client; 509 rc->rc_client = NULL; 510 511 mtx_unlock(&rc->rc_lock); 512 513 if (client) { 514 CLNT_CLOSE(client); 515 CLNT_RELEASE(client); 516 } 517} 518 519static void 520clnt_reconnect_destroy(CLIENT *cl) 521{ 522 struct rc_data *rc = (struct rc_data *)cl->cl_private; 523 SVCXPRT *xprt; 524 525 if (rc->rc_client) 526 CLNT_DESTROY(rc->rc_client); 527 if (rc->rc_backchannel) { 528 xprt = (SVCXPRT *)rc->rc_backchannel; 529 KASSERT(xprt->xp_socket == NULL, 530 ("clnt_reconnect_destroy: xp_socket not NULL")); 531 xprt_unregister(xprt); 532 SVC_RELEASE(xprt); 533 } 534 crfree(rc->rc_ucred); 535 mtx_destroy(&rc->rc_lock); 536 mem_free(rc->rc_reconarg, 0); 537 mem_free(rc, sizeof(*rc)); 538 mem_free(cl, sizeof (CLIENT)); 539} 540