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         rc->rc_tlscertname = NULL;
 114
 115         cl->cl_refs = 1;
 116         cl->cl_ops = &clnt_reconnect_ops;
 117         cl->cl_private = (caddr_t)(void *)rc;
 118         cl->cl_auth = authnone_create();
 119         cl->cl_tp = NULL;
 120         cl->cl_netid = NULL;
 121         return (cl);
 122 }
 123
 124 static enum clnt_stat
 125 clnt_reconnect_connect(CLIENT *cl)
 126 {
 127         struct thread *td = curthread;
 128         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 129         struct socket *so;
 130         enum clnt_stat stat;
 131         int error;
 132         int one = 1;
 133         struct ucred *oldcred;
 134         CLIENT *newclient = NULL;
 135         uint64_t ssl[3];
 136         uint32_t reterr;
 137
 138         mtx_lock(&rc->rc_lock);
 139         while (rc->rc_connecting) {
 140                 error = msleep(rc, &rc->rc_lock,
 141                     rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
 142                 if (error) {
 143                         mtx_unlock(&rc->rc_lock);
 144                         return (RPC_INTR);
 145                 }
 146         }
 147         if (rc->rc_closed) {
 148                 mtx_unlock(&rc->rc_lock);
 149                 return (RPC_CANTSEND);
 150         }
 151         if (rc->rc_client) {
 152                 mtx_unlock(&rc->rc_lock);
 153                 return (RPC_SUCCESS);
 154         }
 155
 156         /*
 157          * My turn to attempt a connect. The rc_connecting variable
 158          * serializes the following code sequence, so it is guaranteed
 159          * that rc_client will still be NULL after it is re-locked below,
 160          * since that is the only place it is set non-NULL.
 161          */
 162         rc->rc_connecting = TRUE;
 163         mtx_unlock(&rc->rc_lock);
 164
 165         oldcred = td->td_ucred;
 166         td->td_ucred = rc->rc_ucred;
 167         so = __rpc_nconf2socket(rc->rc_nconf);
 168         if (!so) {
 169                 stat = rpc_createerr.cf_stat = RPC_TLIERROR;
 170                 rpc_createerr.cf_error.re_errno = 0;
 171                 td->td_ucred = oldcred;
 172                 goto out;
 173         }
 174
 175         if (rc->rc_privport)
 176                 bindresvport(so, NULL);
 177
 178         if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
 179                 newclient = clnt_dg_create(so,
 180                     (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 181                     rc->rc_sendsz, rc->rc_recvsz);
 182         else {
 183                 /*
 184                  * I do not believe a timeout of less than 1sec would make
 185                  * sense here since short delays can occur when a server is
 186                  * temporarily overloaded.
 187                  */
 188                 if (rc->rc_timeout.tv_sec > 0 && rc->rc_timeout.tv_usec >= 0) {
 189                         error = so_setsockopt(so, SOL_SOCKET, SO_SNDTIMEO,
 190                             &rc->rc_timeout, sizeof(struct timeval));
 191                         if (error != 0) {
 192                                 stat = rpc_createerr.cf_stat = RPC_CANTSEND;
 193                                 rpc_createerr.cf_error.re_errno = error;
 194                                 td->td_ucred = oldcred;
 195                                 goto out;
 196                         }
 197                 }
 198                 newclient = clnt_vc_create(so,
 199                     (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 200                     rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
 201                 if (rc->rc_tls && newclient != NULL) {
 202                         stat = rpctls_connect(newclient, rc->rc_tlscertname, so,
 203                             ssl, &reterr);
 204                         if (stat != RPC_SUCCESS || reterr != RPCTLSERR_OK) {
 205                                 if (stat == RPC_SUCCESS)
 206                                         stat = RPC_FAILED;
 207                                 stat = rpc_createerr.cf_stat = stat;
 208                                 rpc_createerr.cf_error.re_errno = 0;
 209                                 CLNT_CLOSE(newclient);
 210                                 CLNT_RELEASE(newclient);
 211                                 newclient = NULL;
 212                                 td->td_ucred = oldcred;
 213                                 goto out;
 214                         }
 215                 }
 216         }
 217         td->td_ucred = oldcred;
 218
 219         if (!newclient) {
 220                 soclose(so);
 221                 rc->rc_err = rpc_createerr.cf_error;
 222                 stat = rpc_createerr.cf_stat;
 223                 goto out;
 224         }
 225
 226         CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0);
 227         CLNT_CONTROL(newclient, CLSET_CONNECT, &one);
 228         CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout);
 229         CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
 230         CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan);
 231         CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr);
 232         if (rc->rc_tls)
 233                 CLNT_CONTROL(newclient, CLSET_TLS, ssl);
 234         if (rc->rc_backchannel != NULL)
 235                 CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel);
 236         stat = RPC_SUCCESS;
 237
 238 out:
 239         mtx_lock(&rc->rc_lock);
 240         KASSERT(rc->rc_client == NULL, ("rc_client not null"));
 241         if (!rc->rc_closed) {
 242                 rc->rc_client = newclient;
 243                 newclient = NULL;
 244         }
 245         rc->rc_connecting = FALSE;
 246         wakeup(rc);
 247         mtx_unlock(&rc->rc_lock);
 248
 249         if (newclient) {
 250                 /*
 251                  * It has been closed, so discard the new client.
 252                  * nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot
 253                  * be called with the rc_lock mutex held, since they may
 254                  * msleep() while holding a different mutex.
 255                  */
 256                 CLNT_CLOSE(newclient);
 257                 CLNT_RELEASE(newclient);
 258         }
 259
 260         return (stat);
 261 }
 262
 263 static enum clnt_stat
 264 clnt_reconnect_call(
 265         CLIENT          *cl,            /* client handle */
 266         struct rpc_callextra *ext,      /* call metadata */
 267         rpcproc_t       proc,           /* procedure number */
 268         struct mbuf     *args,          /* pointer to args */
 269         struct mbuf     **resultsp,     /* pointer to results */
 270         struct timeval  utimeout)
 271 {
 272         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 273         CLIENT *client;
 274         enum clnt_stat stat;
 275         int tries, error;
 276
 277         tries = 0;
 278         do {
 279                 mtx_lock(&rc->rc_lock);
 280                 if (rc->rc_closed) {
 281                         mtx_unlock(&rc->rc_lock);
 282                         return (RPC_CANTSEND);
 283                 }
 284
 285                 if (!rc->rc_client) {
 286                         mtx_unlock(&rc->rc_lock);
 287                         stat = clnt_reconnect_connect(cl);
 288                         if (stat == RPC_SYSTEMERROR) {
 289                                 error = tsleep(&fake_wchan,
 290                                     rc->rc_intr ? PCATCH : 0, "rpccon", hz);
 291                                 if (error == EINTR || error == ERESTART)
 292                                         return (RPC_INTR);
 293                                 tries++;
 294                                 if (tries >= rc->rc_retries)
 295                                         return (stat);
 296                                 continue;
 297                         }
 298                         if (stat != RPC_SUCCESS)
 299                                 return (stat);
 300                         mtx_lock(&rc->rc_lock);
 301                 }
 302
 303                 if (!rc->rc_client) {
 304                         mtx_unlock(&rc->rc_lock);
 305                         stat = RPC_FAILED;
 306                         continue;
 307                 }
 308                 CLNT_ACQUIRE(rc->rc_client);
 309                 client = rc->rc_client;
 310                 mtx_unlock(&rc->rc_lock);
 311                 stat = CLNT_CALL_MBUF(client, ext, proc, args,
 312                     resultsp, utimeout);
 313
 314                 if (stat != RPC_SUCCESS) {
 315                         if (!ext)
 316                                 CLNT_GETERR(client, &rc->rc_err);
 317                 }
 318
 319                 if (stat == RPC_TIMEDOUT) {
 320                         /*
 321                          * Check for async send misfeature for NLM
 322                          * protocol.
 323                          */
 324                         if ((rc->rc_timeout.tv_sec == 0
 325                                 && rc->rc_timeout.tv_usec == 0)
 326                             || (rc->rc_timeout.tv_sec == -1
 327                                 && utimeout.tv_sec == 0
 328                                 && utimeout.tv_usec == 0)) {
 329                                 CLNT_RELEASE(client);
 330                                 break;
 331                         }
 332                 }
 333
 334                 if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
 335                     || stat == RPC_CANTRECV) {
 336                         tries++;
 337                         if (tries >= rc->rc_retries) {
 338                                 CLNT_RELEASE(client);
 339                                 break;
 340                         }
 341
 342                         if (ext && ext->rc_feedback)
 343                                 ext->rc_feedback(FEEDBACK_RECONNECT, proc,
 344                                     ext->rc_feedback_arg);
 345
 346                         mtx_lock(&rc->rc_lock);
 347                         /*
 348                          * Make sure that someone else hasn't already
 349                          * reconnected by checking if rc_client has changed.
 350                          * If not, we are done with the client and must
 351                          * do CLNT_RELEASE(client) twice to dispose of it,
 352                          * because there is both an initial refcnt and one
 353                          * acquired by CLNT_ACQUIRE() above.
 354                          */
 355                         if (rc->rc_client == client) {
 356                                 rc->rc_client = NULL;
 357                                 mtx_unlock(&rc->rc_lock);
 358                                 CLNT_RELEASE(client);
 359                         } else {
 360                                 mtx_unlock(&rc->rc_lock);
 361                         }
 362                         CLNT_RELEASE(client);
 363                 } else {
 364                         CLNT_RELEASE(client);
 365                         break;
 366                 }
 367         } while (stat != RPC_SUCCESS);
 368
 369         KASSERT(stat != RPC_SUCCESS || *resultsp,
 370             ("RPC_SUCCESS without reply"));
 371
 372         return (stat);
 373 }
 374
 375 static void
 376 clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp)
 377 {
 378         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 379
 380         *errp = rc->rc_err;
 381 }
 382
 383 /*
 384  * Since this function requires that rc_client be valid, it can
 385  * only be called when that is guaranteed to be the case.
 386  */
 387 static bool_t
 388 clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
 389 {
 390         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 391
 392         return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr));
 393 }
 394
 395 /*ARGSUSED*/
 396 static void
 397 clnt_reconnect_abort(CLIENT *h)
 398 {
 399 }
 400
 401 /*
 402  * CLNT_CONTROL() on the client returned by clnt_reconnect_create() must
 403  * always be called before CLNT_CALL_MBUF() by a single thread only.
 404  */
 405 static bool_t
 406 clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
 407 {
 408         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 409         SVCXPRT *xprt;
 410         size_t slen;
 411
 412         if (info == NULL) {
 413                 return (FALSE);
 414         }
 415         switch (request) {
 416         case CLSET_TIMEOUT:
 417                 rc->rc_timeout = *(struct timeval *)info;
 418                 if (rc->rc_client)
 419                         CLNT_CONTROL(rc->rc_client, request, info);
 420                 break;
 421
 422         case CLGET_TIMEOUT:
 423                 *(struct timeval *)info = rc->rc_timeout;
 424                 break;
 425
 426         case CLSET_RETRY_TIMEOUT:
 427                 rc->rc_retry = *(struct timeval *)info;
 428                 if (rc->rc_client)
 429                         CLNT_CONTROL(rc->rc_client, request, info);
 430                 break;
 431
 432         case CLGET_RETRY_TIMEOUT:
 433                 *(struct timeval *)info = rc->rc_retry;
 434                 break;
 435
 436         case CLGET_VERS:
 437                 *(uint32_t *)info = rc->rc_vers;
 438                 break;
 439
 440         case CLSET_VERS:
 441                 rc->rc_vers = *(uint32_t *) info;
 442                 if (rc->rc_client)
 443                         CLNT_CONTROL(rc->rc_client, CLSET_VERS, info);
 444                 break;
 445
 446         case CLGET_PROG:
 447                 *(uint32_t *)info = rc->rc_prog;
 448                 break;
 449
 450         case CLSET_PROG:
 451                 rc->rc_prog = *(uint32_t *) info;
 452                 if (rc->rc_client)
 453                         CLNT_CONTROL(rc->rc_client, request, info);
 454                 break;
 455
 456         case CLSET_WAITCHAN:
 457                 rc->rc_waitchan = (char *)info;
 458                 if (rc->rc_client)
 459                         CLNT_CONTROL(rc->rc_client, request, info);
 460                 break;
 461
 462         case CLGET_WAITCHAN:
 463                 *(const char **) info = rc->rc_waitchan;
 464                 break;
 465
 466         case CLSET_INTERRUPTIBLE:
 467                 rc->rc_intr = *(int *) info;
 468                 if (rc->rc_client)
 469                         CLNT_CONTROL(rc->rc_client, request, info);
 470                 break;
 471
 472         case CLGET_INTERRUPTIBLE:
 473                 *(int *) info = rc->rc_intr;
 474                 break;
 475
 476         case CLSET_RETRIES:
 477                 rc->rc_retries = *(int *) info;
 478                 break;
 479
 480         case CLGET_RETRIES:
 481                 *(int *) info = rc->rc_retries;
 482                 break;
 483
 484         case CLSET_PRIVPORT:
 485                 rc->rc_privport = *(int *) info;
 486                 break;
 487
 488         case CLGET_PRIVPORT:
 489                 *(int *) info = rc->rc_privport;
 490                 break;
 491
 492         case CLSET_BACKCHANNEL:
 493                 xprt = (SVCXPRT *)info;
 494                 xprt_register(xprt);
 495                 rc->rc_backchannel = info;
 496                 break;
 497
 498         case CLSET_TLS:
 499                 rc->rc_tls = true;
 500                 break;
 501
 502         case CLSET_TLSCERTNAME:
 503                 slen = strlen(info) + 1;
 504                 /*
 505                  * tlscertname with "key.pem" appended to it forms a file
 506                  * name.  As such, the maximum allowable strlen(info) is
 507                  * NAME_MAX - 7. However, "slen" includes the nul termination
 508                  * byte so it can be up to NAME_MAX - 6.
 509                  */
 510                 if (slen <= 1 || slen > NAME_MAX - 6)
 511                         return (FALSE);
 512                 rc->rc_tlscertname = mem_alloc(slen);
 513                 strlcpy(rc->rc_tlscertname, info, slen);
 514                 break;
 515
 516         default:
 517                 return (FALSE);
 518         }
 519
 520         return (TRUE);
 521 }
 522
 523 static void
 524 clnt_reconnect_close(CLIENT *cl)
 525 {
 526         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 527         CLIENT *client;
 528
 529         mtx_lock(&rc->rc_lock);
 530
 531         if (rc->rc_closed) {
 532                 mtx_unlock(&rc->rc_lock);
 533                 return;
 534         }
 535
 536         rc->rc_closed = TRUE;
 537         client = rc->rc_client;
 538         rc->rc_client = NULL;
 539
 540         mtx_unlock(&rc->rc_lock);
 541
 542         if (client) {
 543                 CLNT_CLOSE(client);
 544                 CLNT_RELEASE(client);
 545         }
 546 }
 547
 548 static void
 549 clnt_reconnect_destroy(CLIENT *cl)
 550 {
 551         struct rc_data *rc = (struct rc_data *)cl->cl_private;
 552         SVCXPRT *xprt;
 553
 554         if (rc->rc_client)
 555                 CLNT_DESTROY(rc->rc_client);
 556         if (rc->rc_backchannel) {
 557                 xprt = (SVCXPRT *)rc->rc_backchannel;
 558                 xprt_unregister(xprt);
 559                 SVC_RELEASE(xprt);
 560         }
 561         crfree(rc->rc_ucred);
 562         mtx_destroy(&rc->rc_lock);
 563         mem_free(rc->rc_tlscertname, 0);        /* 0 ok, since arg. ignored. */
 564         mem_free(rc, sizeof(*rc));
 565         mem_free(cl, sizeof (CLIENT));
 566 }