sys/rpc/clnt_rc.c

   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 #include <rpc/rpcsec_tls.h>
  52
  53 static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *,
  54     rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
  55 static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *);
  56 static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *);
  57 static void clnt_reconnect_abort(CLIENT *);
  58 static bool_t clnt_reconnect_control(CLIENT *, u_int, void *);
  59 static void clnt_reconnect_close(CLIENT *);
  60 static void clnt_reconnect_destroy(CLIENT *);
  61
  62 static struct clnt_ops clnt_reconnect_ops = {
  63         .cl_call =      clnt_reconnect_call,
  64         .cl_abort =     clnt_reconnect_abort,
  65         .cl_geterr =    clnt_reconnect_geterr,
  66         .cl_freeres =   clnt_reconnect_freeres,
  67         .cl_close =     clnt_reconnect_close,
  68         .cl_destroy =   clnt_reconnect_destroy,
  69         .cl_control =   clnt_reconnect_control
  70 };
  71
  72 static int      fake_wchan;
  73
  74 CLIENT *
  75 clnt_reconnect_create(
  76         struct netconfig *nconf,        /* network type */
  77         struct sockaddr *svcaddr,       /* servers address */
  78         rpcprog_t program,              /* program number */
  79         rpcvers_t version,              /* version number */
  80         size_t sendsz,                  /* buffer recv size */
  81         size_t recvsz)                  /* buffer send size */
  82 {
  83         CLIENT *cl = NULL;              /* client handle */
  84         struct rc_data *rc = NULL;      /* private data */
  85
  86         if (svcaddr == NULL) {
  87                 rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
  88                 return (NULL);
  89         }
  90
  91         cl = mem_alloc(sizeof (CLIENT));
  92         rc = mem_alloc(sizeof (*rc));
  93         mtx_init(&rc->rc_lock, "rc->rc_lock", NULL, MTX_DEF);
  94         (void) memcpy(&rc->rc_addr, svcaddr, (size_t)svcaddr->sa_len);
  95         rc->rc_nconf = nconf;
  96         rc->rc_prog = program;
  97         rc->rc_vers = version;
  98         rc->rc_sendsz = sendsz;
  99         rc->rc_recvsz = recvsz;
 100         rc->rc_timeout.tv_sec = -1;
 101         rc->rc_timeout.tv_usec = -1;
 102         rc->rc_retry.tv_sec = 3;
 103         rc->rc_retry.tv_usec = 0;
 104         rc->rc_retries = INT_MAX;
 105         rc->rc_privport = FALSE;
 106         rc->rc_waitchan = "rpcrecv";
 107         rc->rc_intr = 0;
 108         rc->rc_connecting = FALSE;
 109         rc->rc_closed = FALSE;
 110         rc->rc_ucred = crdup(curthread->td_ucred);
 111         rc->rc_client = NULL;
 112         rc->rc_tls = false;
 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
 123 static enum clnt_stat
 124 clnt_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         uint64_t ssl[3];
 135         uint32_t reterr;
 136
 137         mtx_lock(&rc->rc_lock);
 138         while (rc->rc_connecting) {
 139                 error = msleep(rc, &rc->rc_lock,
 140                     rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
 141                 if (error) {
 142                         mtx_unlock(&rc->rc_lock);
 143                         return (RPC_INTR);
 144                 }
 145         }
 146         if (rc->rc_closed) {
 147                 mtx_unlock(&rc->rc_lock);
 148                 return (RPC_CANTSEND);
 149         }
 150         if (rc->rc_client) {
 151                 mtx_unlock(&rc->rc_lock);
 152                 return (RPC_SUCCESS);
 153         }
 154
 155         /*
 156          * My turn to attempt a connect. The rc_connecting variable
 157          * serializes the following code sequence, so it is guaranteed
 158          * that rc_client will still be NULL after it is re-locked below,
 159          * since that is the only place it is set non-NULL.
 160          */
 161         rc->rc_connecting = TRUE;
 162         mtx_unlock(&rc->rc_lock);
 163
 164         oldcred = td->td_ucred;
 165         td->td_ucred = rc->rc_ucred;
 166         so = __rpc_nconf2socket(rc->rc_nconf);
 167         if (!so) {
 168                 stat = rpc_createerr.cf_stat = RPC_TLIERROR;
 169                 rpc_createerr.cf_error.re_errno = 0;
 170                 td->td_ucred = oldcred;
 171                 goto out;
 172         }
 173
 174         if (rc->rc_privport)
 175                 bindresvport(so, NULL);
 176
 177         if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
 178                 newclient = clnt_dg_create(so,
 179                     (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 180                     rc->rc_sendsz, rc->rc_recvsz);
 181         else {
 182                 /*
 183                  * I do not believe a timeout of less than 1sec would make
 184                  * sense here since short delays can occur when a server is
 185                  * temporarily overloaded.
 186                  */
 187                 if (rc->rc_timeout.tv_sec > 0 && rc->rc_timeout.tv_usec >= 0) {
 188                         error = so_setsockopt(so, SOL_SOCKET, SO_SNDTIMEO,
 189                             &rc->rc_timeout, sizeof(struct timeval));
 190                         if (error != 0) {
 191                                 stat = rpc_createerr.cf_stat = RPC_CANTSEND;
 192                                 rpc_createerr.cf_error.re_errno = error;
 193                                 td->td_ucred = oldcred;
 194                                 goto out;
 195                         }
 196                 }
 197                 newclient = clnt_vc_create(so,
 198                     (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 199                     rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
 200                 if (rc->rc_tls && newclient != NULL) {
 201                         stat = rpctls_connect(newclient, so, ssl, &reterr);
 202                         if (stat != RPC_SUCCESS || reterr != RPCTLSERR_OK) {
 203                                 if (stat == RPC_SUCCESS)
 204                                         stat = RPC_FAILED;
 205                                 stat = rpc_createerr.cf_stat = stat;
 206                                 rpc_createerr.cf_error.re_errno = 0;
 207                                 CLNT_CLOSE(newclient);
 208                                 CLNT_RELEASE(newclient);
 209                                 newclient = NULL;
 210                                 td->td_ucred = oldcred;
 211                                 goto out;
 212                         }
 213                 }
 214         }
 215         td->td_ucred = oldcred;
 216
 217         if (!newclient) {
 218                 soclose(so);
 219                 rc->rc_err = rpc_createerr.cf_error;
 220                 stat = rpc_createerr.cf_stat;
 221                 goto out;
 222         }
 223
 224         CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0);
 225         CLNT_CONTROL(newclient, CLSET_CONNECT, &one);
 226         CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout);
 227         CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
 228         CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan);
 229         CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr);
 230         if (rc->rc_tls)
 231                 CLNT_CONTROL(newclient, CLSET_TLS, ssl);
 232         if (rc->rc_backchannel != NULL)
 233                 CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel);
 234         stat = RPC_SUCCESS;
 235
 236 out:
 237         mtx_lock(&rc->rc_lock);
 238         KASSERT(rc->rc_client == NULL, ("rc_client not null"));
 239         if (!rc->rc_closed) {
 240                 rc->rc_client = newclient;
 241                 newclient = NULL;
 242         }
 243         rc->rc_connecting = FALSE;
 244         wakeup(rc);
 245         mtx_unlock(&rc->rc_lock);
 246
 247         if (newclient) {
 248                 /*
 249                  * It has been closed, so discard the new client.
 250                  * nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot
 251                  * be called with the rc_lock mutex held, since they may
 252                  * msleep() while holding a different mutex.
 253                  */
 254                 CLNT_CLOSE(newclient);
 255                 CLNT_RELEASE(newclient);
 256         }
 257
 258         return (stat);
 259 }
 260
 261 static enum clnt_stat
 262 clnt_reconnect_call(
 263         CLIENT          *cl,            /* client handle */
 264         struct rpc_callextra *ext,      /* call metadata */
 265         rpcproc_t       proc,           /* procedure number */
 266         struct mbuf     *args,          /* pointer to args */
 267         struct mbuf     **resultsp,     /* pointer to results */
 268         struct timeval  utimeout)
 269 {
 270         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 271         CLIENT *client;
 272         enum clnt_stat stat;
 273         int tries, error;
 274
 275         tries = 0;
 276         do {
 277                 mtx_lock(&rc->rc_lock);
 278                 if (rc->rc_closed) {
 279                         mtx_unlock(&rc->rc_lock);
 280                         return (RPC_CANTSEND);
 281                 }
 282
 283                 if (!rc->rc_client) {
 284                         mtx_unlock(&rc->rc_lock);
 285                         stat = clnt_reconnect_connect(cl);
 286                         if (stat == RPC_SYSTEMERROR) {
 287                                 error = tsleep(&fake_wchan,
 288                                     rc->rc_intr ? PCATCH : 0, "rpccon", hz);
 289                                 if (error == EINTR || error == ERESTART)
 290                                         return (RPC_INTR);
 291                                 tries++;
 292                                 if (tries >= rc->rc_retries)
 293                                         return (stat);
 294                                 continue;
 295                         }
 296                         if (stat != RPC_SUCCESS)
 297                                 return (stat);
 298                         mtx_lock(&rc->rc_lock);
 299                 }
 300
 301                 if (!rc->rc_client) {
 302                         mtx_unlock(&rc->rc_lock);
 303                         stat = RPC_FAILED;
 304                         continue;
 305                 }
 306                 CLNT_ACQUIRE(rc->rc_client);
 307                 client = rc->rc_client;
 308                 mtx_unlock(&rc->rc_lock);
 309                 stat = CLNT_CALL_MBUF(client, ext, proc, args,
 310                     resultsp, utimeout);
 311
 312                 if (stat != RPC_SUCCESS) {
 313                         if (!ext)
 314                                 CLNT_GETERR(client, &rc->rc_err);
 315                 }
 316
 317                 if (stat == RPC_TIMEDOUT) {
 318                         /*
 319                          * Check for async send misfeature for NLM
 320                          * protocol.
 321                          */
 322                         if ((rc->rc_timeout.tv_sec == 0
 323                                 && rc->rc_timeout.tv_usec == 0)
 324                             || (rc->rc_timeout.tv_sec == -1
 325                                 && utimeout.tv_sec == 0
 326                                 && utimeout.tv_usec == 0)) {
 327                                 CLNT_RELEASE(client);
 328                                 break;
 329                         }
 330                 }
 331
 332                 if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
 333                     || stat == RPC_CANTRECV) {
 334                         tries++;
 335                         if (tries >= rc->rc_retries) {
 336                                 CLNT_RELEASE(client);
 337                                 break;
 338                         }
 339
 340                         if (ext && ext->rc_feedback)
 341                                 ext->rc_feedback(FEEDBACK_RECONNECT, proc,
 342                                     ext->rc_feedback_arg);
 343
 344                         mtx_lock(&rc->rc_lock);
 345                         /*
 346                          * Make sure that someone else hasn't already
 347                          * reconnected by checking if rc_client has changed.
 348                          * If not, we are done with the client and must
 349                          * do CLNT_RELEASE(client) twice to dispose of it,
 350                          * because there is both an initial refcnt and one
 351                          * acquired by CLNT_ACQUIRE() above.
 352                          */
 353                         if (rc->rc_client == client) {
 354                                 rc->rc_client = NULL;
 355                                 mtx_unlock(&rc->rc_lock);
 356                                 CLNT_RELEASE(client);
 357                         } else {
 358                                 mtx_unlock(&rc->rc_lock);
 359                         }
 360                         CLNT_RELEASE(client);
 361                 } else {
 362                         CLNT_RELEASE(client);
 363                         break;
 364                 }
 365         } while (stat != RPC_SUCCESS);
 366
 367         KASSERT(stat != RPC_SUCCESS || *resultsp,
 368             ("RPC_SUCCESS without reply"));
 369
 370         return (stat);
 371 }
 372
 373 static void
 374 clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp)
 375 {
 376         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 377
 378         *errp = rc->rc_err;
 379 }
 380
 381 /*
 382  * Since this function requires that rc_client be valid, it can
 383  * only be called when that is guaranteed to be the case.
 384  */
 385 static bool_t
 386 clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
 387 {
 388         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 389
 390         return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr));
 391 }
 392
 393 /*ARGSUSED*/
 394 static void
 395 clnt_reconnect_abort(CLIENT *h)
 396 {
 397 }
 398
 399 /*
 400  * CLNT_CONTROL() on the client returned by clnt_reconnect_create() must
 401  * always be called before CLNT_CALL_MBUF() by a single thread only.
 402  */
 403 static bool_t
 404 clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
 405 {
 406         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 407         SVCXPRT *xprt;
 408
 409         if (info == NULL) {
 410                 return (FALSE);
 411         }
 412         switch (request) {
 413         case CLSET_TIMEOUT:
 414                 rc->rc_timeout = *(struct timeval *)info;
 415                 if (rc->rc_client)
 416                         CLNT_CONTROL(rc->rc_client, request, info);
 417                 break;
 418
 419         case CLGET_TIMEOUT:
 420                 *(struct timeval *)info = rc->rc_timeout;
 421                 break;
 422
 423         case CLSET_RETRY_TIMEOUT:
 424                 rc->rc_retry = *(struct timeval *)info;
 425                 if (rc->rc_client)
 426                         CLNT_CONTROL(rc->rc_client, request, info);
 427                 break;
 428
 429         case CLGET_RETRY_TIMEOUT:
 430                 *(struct timeval *)info = rc->rc_retry;
 431                 break;
 432
 433         case CLGET_VERS:
 434                 *(uint32_t *)info = rc->rc_vers;
 435                 break;
 436
 437         case CLSET_VERS:
 438                 rc->rc_vers = *(uint32_t *) info;
 439                 if (rc->rc_client)
 440                         CLNT_CONTROL(rc->rc_client, CLSET_VERS, info);
 441                 break;
 442
 443         case CLGET_PROG:
 444                 *(uint32_t *)info = rc->rc_prog;
 445                 break;
 446
 447         case CLSET_PROG:
 448                 rc->rc_prog = *(uint32_t *) info;
 449                 if (rc->rc_client)
 450                         CLNT_CONTROL(rc->rc_client, request, info);
 451                 break;
 452
 453         case CLSET_WAITCHAN:
 454                 rc->rc_waitchan = (char *)info;
 455                 if (rc->rc_client)
 456                         CLNT_CONTROL(rc->rc_client, request, info);
 457                 break;
 458
 459         case CLGET_WAITCHAN:
 460                 *(const char **) info = rc->rc_waitchan;
 461                 break;
 462
 463         case CLSET_INTERRUPTIBLE:
 464                 rc->rc_intr = *(int *) info;
 465                 if (rc->rc_client)
 466                         CLNT_CONTROL(rc->rc_client, request, info);
 467                 break;
 468
 469         case CLGET_INTERRUPTIBLE:
 470                 *(int *) info = rc->rc_intr;
 471                 break;
 472
 473         case CLSET_RETRIES:
 474                 rc->rc_retries = *(int *) info;
 475                 break;
 476
 477         case CLGET_RETRIES:
 478                 *(int *) info = rc->rc_retries;
 479                 break;
 480
 481         case CLSET_PRIVPORT:
 482                 rc->rc_privport = *(int *) info;
 483                 break;
 484
 485         case CLGET_PRIVPORT:
 486                 *(int *) info = rc->rc_privport;
 487                 break;
 488
 489         case CLSET_BACKCHANNEL:
 490                 xprt = (SVCXPRT *)info;
 491                 xprt_register(xprt);
 492                 rc->rc_backchannel = info;
 493                 break;
 494
 495         case CLSET_TLS:
 496                 rc->rc_tls = true;
 497                 break;
 498
 499         default:
 500                 return (FALSE);
 501         }
 502
 503         return (TRUE);
 504 }
 505
 506 static void
 507 clnt_reconnect_close(CLIENT *cl)
 508 {
 509         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 510         CLIENT *client;
 511
 512         mtx_lock(&rc->rc_lock);
 513
 514         if (rc->rc_closed) {
 515                 mtx_unlock(&rc->rc_lock);
 516                 return;
 517         }
 518
 519         rc->rc_closed = TRUE;
 520         client = rc->rc_client;
 521         rc->rc_client = NULL;
 522
 523         mtx_unlock(&rc->rc_lock);
 524
 525         if (client) {
 526                 CLNT_CLOSE(client);
 527                 CLNT_RELEASE(client);
 528         }
 529 }
 530
 531 static void
 532 clnt_reconnect_destroy(CLIENT *cl)
 533 {
 534         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 535         SVCXPRT *xprt;
 536
 537         if (rc->rc_client)
 538                 CLNT_DESTROY(rc->rc_client);
 539         if (rc->rc_backchannel) {
 540                 xprt = (SVCXPRT *)rc->rc_backchannel;
 541                 xprt_unregister(xprt);
 542                 SVC_RELEASE(xprt);
 543         }
 544         crfree(rc->rc_ucred);
 545         mtx_destroy(&rc->rc_lock);
 546         mem_free(rc, sizeof(*rc));
 547         mem_free(cl, sizeof (CLIENT));
 548 }