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