sys/rpc/clnt_dg.c

   1 /*      $NetBSD: clnt_dg.c,v 1.4 2000/07/14 08:40:41 fvdl Exp $ */
   2
   3 /*
   4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   5  * unrestricted use provided that this legend is included on all tape
   6  * media and as a part of the software program in whole or part.  Users
   7  * may copy or modify Sun RPC without charge, but are not authorized
   8  * to license or distribute it to anyone else except as part of a product or
   9  * program developed by the user.
  10  *
  11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  14  *
  15  * Sun RPC is provided with no support and without any obligation on the
  16  * part of Sun Microsystems, Inc. to assist in its use, correction,
  17  * modification or enhancement.
  18  *
  19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  21  * OR ANY PART THEREOF.
  22  *
  23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  24  * or profits or other special, indirect and consequential damages, even if
  25  * Sun has been advised of the possibility of such damages.
  26  *
  27  * Sun Microsystems, Inc.
  28  * 2550 Garcia Avenue
  29  * Mountain View, California  94043
  30  */
  31 /*
  32  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
  33  */
  34
  35 #if defined(LIBC_SCCS) && !defined(lint)
  36 #ident  "@(#)clnt_dg.c  1.23    94/04/22 SMI"
  37 static char sccsid[] = "@(#)clnt_dg.c 1.19 89/03/16 Copyr 1988 Sun Micro";
  38 #endif
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41
  42 /*
  43  * Implements a connectionless client side RPC.
  44  */
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/kernel.h>
  49 #include <sys/lock.h>
  50 #include <sys/malloc.h>
  51 #include <sys/mbuf.h>
  52 #include <sys/mutex.h>
  53 #include <sys/pcpu.h>
  54 #include <sys/proc.h>
  55 #include <sys/socket.h>
  56 #include <sys/socketvar.h>
  57 #include <sys/time.h>
  58 #include <sys/uio.h>
  59
  60 #include <net/vnet.h>
  61
  62 #include <rpc/rpc.h>
  63 #include <rpc/rpc_com.h>
  64
  65
  66 #ifdef _FREEFALL_CONFIG
  67 /*
  68  * Disable RPC exponential back-off for FreeBSD.org systems.
  69  */
  70 #define RPC_MAX_BACKOFF         1 /* second */
  71 #else
  72 #define RPC_MAX_BACKOFF         30 /* seconds */
  73 #endif
  74
  75 static bool_t time_not_ok(struct timeval *);
  76 static enum clnt_stat clnt_dg_call(CLIENT *, struct rpc_callextra *,
  77     rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
  78 static void clnt_dg_geterr(CLIENT *, struct rpc_err *);
  79 static bool_t clnt_dg_freeres(CLIENT *, xdrproc_t, void *);
  80 static void clnt_dg_abort(CLIENT *);
  81 static bool_t clnt_dg_control(CLIENT *, u_int, void *);
  82 static void clnt_dg_close(CLIENT *);
  83 static void clnt_dg_destroy(CLIENT *);
  84 static int clnt_dg_soupcall(struct socket *so, void *arg, int waitflag);
  85
  86 static struct clnt_ops clnt_dg_ops = {
  87         .cl_call =      clnt_dg_call,
  88         .cl_abort =     clnt_dg_abort,
  89         .cl_geterr =    clnt_dg_geterr,
  90         .cl_freeres =   clnt_dg_freeres,
  91         .cl_close =     clnt_dg_close,
  92         .cl_destroy =   clnt_dg_destroy,
  93         .cl_control =   clnt_dg_control
  94 };
  95
  96 static const char mem_err_clnt_dg[] = "clnt_dg_create: out of memory";
  97
  98 /*
  99  * A pending RPC request which awaits a reply. Requests which have
 100  * received their reply will have cr_xid set to zero and cr_mrep to
 101  * the mbuf chain of the reply.
 102  */
 103 struct cu_request {
 104         TAILQ_ENTRY(cu_request) cr_link;
 105         CLIENT                  *cr_client;     /* owner */
 106         uint32_t                cr_xid;         /* XID of request */
 107         struct mbuf             *cr_mrep;       /* reply received by upcall */
 108         int                     cr_error;       /* any error from upcall */
 109         char                    cr_verf[MAX_AUTH_BYTES]; /* reply verf */
 110 };
 111
 112 TAILQ_HEAD(cu_request_list, cu_request);
 113
 114 #define MCALL_MSG_SIZE 24
 115
 116 /*
 117  * This structure is pointed to by the socket buffer's sb_upcallarg
 118  * member. It is separate from the client private data to facilitate
 119  * multiple clients sharing the same socket. The cs_lock mutex is used
 120  * to protect all fields of this structure, the socket's receive
 121  * buffer SOCKBUF_LOCK is used to ensure that exactly one of these
 122  * structures is installed on the socket.
 123  */
 124 struct cu_socket {
 125         struct mtx              cs_lock;
 126         int                     cs_refs;        /* Count of clients */
 127         struct cu_request_list  cs_pending;     /* Requests awaiting replies */
 128         int                     cs_upcallrefs;  /* Refcnt of upcalls in prog.*/
 129 };
 130
 131 static void clnt_dg_upcallsdone(struct socket *, struct cu_socket *);
 132
 133 /*
 134  * Private data kept per client handle
 135  */
 136 struct cu_data {
 137         int                     cu_threads;     /* # threads in clnt_vc_call */
 138         bool_t                  cu_closing;     /* TRUE if we are closing */
 139         bool_t                  cu_closed;      /* TRUE if we are closed */
 140         struct socket           *cu_socket;     /* connection socket */
 141         bool_t                  cu_closeit;     /* opened by library */
 142         struct sockaddr_storage cu_raddr;       /* remote address */
 143         int                     cu_rlen;
 144         struct timeval          cu_wait;        /* retransmit interval */
 145         struct timeval          cu_total;       /* total time for the call */
 146         struct rpc_err          cu_error;
 147         uint32_t                cu_xid;
 148         char                    cu_mcallc[MCALL_MSG_SIZE]; /* marshalled callmsg */
 149         size_t                  cu_mcalllen;
 150         size_t                  cu_sendsz;      /* send size */
 151         size_t                  cu_recvsz;      /* recv size */
 152         int                     cu_async;
 153         int                     cu_connect;     /* Use connect(). */
 154         int                     cu_connected;   /* Have done connect(). */
 155         const char              *cu_waitchan;
 156         int                     cu_waitflag;
 157         int                     cu_cwnd;        /* congestion window */
 158         int                     cu_sent;        /* number of in-flight RPCs */
 159         bool_t                  cu_cwnd_wait;
 160 };
 161
 162 #define CWNDSCALE       256
 163 #define MAXCWND         (32 * CWNDSCALE)
 164
 165 /*
 166  * Connection less client creation returns with client handle parameters.
 167  * Default options are set, which the user can change using clnt_control().
 168  * fd should be open and bound.
 169  * NB: The rpch->cl_auth is initialized to null authentication.
 170  *      Caller may wish to set this something more useful.
 171  *
 172  * sendsz and recvsz are the maximum allowable packet sizes that can be
 173  * sent and received. Normally they are the same, but they can be
 174  * changed to improve the program efficiency and buffer allocation.
 175  * If they are 0, use the transport default.
 176  *
 177  * If svcaddr is NULL, returns NULL.
 178  */
 179 CLIENT *
 180 clnt_dg_create(
 181         struct socket *so,
 182         struct sockaddr *svcaddr,       /* servers address */
 183         rpcprog_t program,              /* program number */
 184         rpcvers_t version,              /* version number */
 185         size_t sendsz,                  /* buffer recv size */
 186         size_t recvsz)                  /* buffer send size */
 187 {
 188         CLIENT *cl = NULL;              /* client handle */
 189         struct cu_data *cu = NULL;      /* private data */
 190         struct cu_socket *cs = NULL;
 191         struct sockbuf *sb;
 192         struct timeval now;
 193         struct rpc_msg call_msg;
 194         struct __rpc_sockinfo si;
 195         XDR xdrs;
 196         int error;
 197
 198         if (svcaddr == NULL) {
 199                 rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
 200                 return (NULL);
 201         }
 202
 203         if (!__rpc_socket2sockinfo(so, &si)) {
 204                 rpc_createerr.cf_stat = RPC_TLIERROR;
 205                 rpc_createerr.cf_error.re_errno = 0;
 206                 return (NULL);
 207         }
 208
 209         /*
 210          * Find the receive and the send size
 211          */
 212         sendsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsz);
 213         recvsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsz);
 214         if ((sendsz == 0) || (recvsz == 0)) {
 215                 rpc_createerr.cf_stat = RPC_TLIERROR; /* XXX */
 216                 rpc_createerr.cf_error.re_errno = 0;
 217                 return (NULL);
 218         }
 219
 220         cl = mem_alloc(sizeof (CLIENT));
 221
 222         /*
 223          * Should be multiple of 4 for XDR.
 224          */
 225         sendsz = ((sendsz + 3) / 4) * 4;
 226         recvsz = ((recvsz + 3) / 4) * 4;
 227         cu = mem_alloc(sizeof (*cu));
 228         cu->cu_threads = 0;
 229         cu->cu_closing = FALSE;
 230         cu->cu_closed = FALSE;
 231         (void) memcpy(&cu->cu_raddr, svcaddr, (size_t)svcaddr->sa_len);
 232         cu->cu_rlen = svcaddr->sa_len;
 233         /* Other values can also be set through clnt_control() */
 234         cu->cu_wait.tv_sec = 3; /* heuristically chosen */
 235         cu->cu_wait.tv_usec = 0;
 236         cu->cu_total.tv_sec = -1;
 237         cu->cu_total.tv_usec = -1;
 238         cu->cu_sendsz = sendsz;
 239         cu->cu_recvsz = recvsz;
 240         cu->cu_async = FALSE;
 241         cu->cu_connect = FALSE;
 242         cu->cu_connected = FALSE;
 243         cu->cu_waitchan = "rpcrecv";
 244         cu->cu_waitflag = 0;
 245         cu->cu_cwnd = MAXCWND / 2;
 246         cu->cu_sent = 0;
 247         cu->cu_cwnd_wait = FALSE;
 248         (void) getmicrotime(&now);
 249         cu->cu_xid = __RPC_GETXID(&now);
 250         call_msg.rm_xid = cu->cu_xid;
 251         call_msg.rm_call.cb_prog = program;
 252         call_msg.rm_call.cb_vers = version;
 253         xdrmem_create(&xdrs, cu->cu_mcallc, MCALL_MSG_SIZE, XDR_ENCODE);
 254         if (! xdr_callhdr(&xdrs, &call_msg)) {
 255                 rpc_createerr.cf_stat = RPC_CANTENCODEARGS;  /* XXX */
 256                 rpc_createerr.cf_error.re_errno = 0;
 257                 goto err2;
 258         }
 259         cu->cu_mcalllen = XDR_GETPOS(&xdrs);
 260
 261         /*
 262          * By default, closeit is always FALSE. It is users responsibility
 263          * to do a close on it, else the user may use clnt_control
 264          * to let clnt_destroy do it for him/her.
 265          */
 266         cu->cu_closeit = FALSE;
 267         cu->cu_socket = so;
 268         error = soreserve(so, (u_long)sendsz, (u_long)recvsz);
 269         if (error != 0) {
 270                 rpc_createerr.cf_stat = RPC_FAILED;
 271                 rpc_createerr.cf_error.re_errno = error;
 272                 goto err2;
 273         }
 274
 275         sb = &so->so_rcv;
 276         SOCKBUF_LOCK(&so->so_rcv);
 277 recheck_socket:
 278         if (sb->sb_upcall) {
 279                 if (sb->sb_upcall != clnt_dg_soupcall) {
 280                         SOCKBUF_UNLOCK(&so->so_rcv);
 281                         printf("clnt_dg_create(): socket already has an incompatible upcall\n");
 282                         goto err2;
 283                 }
 284                 cs = (struct cu_socket *) sb->sb_upcallarg;
 285                 mtx_lock(&cs->cs_lock);
 286                 cs->cs_refs++;
 287                 mtx_unlock(&cs->cs_lock);
 288         } else {
 289                 /*
 290                  * We are the first on this socket - allocate the
 291                  * structure and install it in the socket.
 292                  */
 293                 SOCKBUF_UNLOCK(&so->so_rcv);
 294                 cs = mem_alloc(sizeof(*cs));
 295                 SOCKBUF_LOCK(&so->so_rcv);
 296                 if (sb->sb_upcall) {
 297                         /*
 298                          * We have lost a race with some other client.
 299                          */
 300                         mem_free(cs, sizeof(*cs));
 301                         goto recheck_socket;
 302                 }
 303                 mtx_init(&cs->cs_lock, "cs->cs_lock", NULL, MTX_DEF);
 304                 cs->cs_refs = 1;
 305                 cs->cs_upcallrefs = 0;
 306                 TAILQ_INIT(&cs->cs_pending);
 307                 soupcall_set(so, SO_RCV, clnt_dg_soupcall, cs);
 308         }
 309         SOCKBUF_UNLOCK(&so->so_rcv);
 310
 311         cl->cl_refs = 1;
 312         cl->cl_ops = &clnt_dg_ops;
 313         cl->cl_private = (caddr_t)(void *)cu;
 314         cl->cl_auth = authnone_create();
 315         cl->cl_tp = NULL;
 316         cl->cl_netid = NULL;
 317         return (cl);
 318 err2:
 319         if (cl) {
 320                 mem_free(cl, sizeof (CLIENT));
 321                 if (cu)
 322                         mem_free(cu, sizeof (*cu));
 323         }
 324         return (NULL);
 325 }
 326
 327 static enum clnt_stat
 328 clnt_dg_call(
 329         CLIENT          *cl,            /* client handle */
 330         struct rpc_callextra *ext,      /* call metadata */
 331         rpcproc_t       proc,           /* procedure number */
 332         struct mbuf     *args,          /* pointer to args */
 333         struct mbuf     **resultsp,     /* pointer to results */
 334         struct timeval  utimeout)       /* seconds to wait before giving up */
 335 {
 336         struct cu_data *cu = (struct cu_data *)cl->cl_private;
 337         struct cu_socket *cs;
 338         struct rpc_timers *rt;
 339         AUTH *auth;
 340         struct rpc_err *errp;
 341         enum clnt_stat stat;
 342         XDR xdrs;
 343         struct rpc_msg reply_msg;
 344         bool_t ok;
 345         int retrans;                    /* number of re-transmits so far */
 346         int nrefreshes = 2;             /* number of times to refresh cred */
 347         struct timeval *tvp;
 348         int timeout;
 349         int retransmit_time;
 350         int next_sendtime, starttime, rtt, time_waited, tv = 0;
 351         struct sockaddr *sa;
 352         socklen_t salen;
 353         uint32_t xid = 0;
 354         struct mbuf *mreq = NULL, *results;
 355         struct cu_request *cr;
 356         int error;
 357
 358         cs = cu->cu_socket->so_rcv.sb_upcallarg;
 359         cr = malloc(sizeof(struct cu_request), M_RPC, M_WAITOK);
 360
 361         mtx_lock(&cs->cs_lock);
 362
 363         if (cu->cu_closing || cu->cu_closed) {
 364                 mtx_unlock(&cs->cs_lock);
 365                 free(cr, M_RPC);
 366                 return (RPC_CANTSEND);
 367         }
 368         cu->cu_threads++;
 369
 370         if (ext) {
 371                 auth = ext->rc_auth;
 372                 errp = &ext->rc_err;
 373         } else {
 374                 auth = cl->cl_auth;
 375                 errp = &cu->cu_error;
 376         }
 377
 378         cr->cr_client = cl;
 379         cr->cr_mrep = NULL;
 380         cr->cr_error = 0;
 381
 382         if (cu->cu_total.tv_usec == -1) {
 383                 tvp = &utimeout; /* use supplied timeout */
 384         } else {
 385                 tvp = &cu->cu_total; /* use default timeout */
 386         }
 387         if (tvp->tv_sec || tvp->tv_usec)
 388                 timeout = tvtohz(tvp);
 389         else
 390                 timeout = 0;
 391
 392         if (cu->cu_connect && !cu->cu_connected) {
 393                 mtx_unlock(&cs->cs_lock);
 394                 error = soconnect(cu->cu_socket,
 395                     (struct sockaddr *)&cu->cu_raddr, curthread);
 396                 mtx_lock(&cs->cs_lock);
 397                 if (error) {
 398                         errp->re_errno = error;
 399                         errp->re_status = stat = RPC_CANTSEND;
 400                         goto out;
 401                 }
 402                 cu->cu_connected = 1;
 403         }
 404         if (cu->cu_connected) {
 405                 sa = NULL;
 406                 salen = 0;
 407         } else {
 408                 sa = (struct sockaddr *)&cu->cu_raddr;
 409                 salen = cu->cu_rlen;
 410         }
 411         time_waited = 0;
 412         retrans = 0;
 413         if (ext && ext->rc_timers) {
 414                 rt = ext->rc_timers;
 415                 if (!rt->rt_rtxcur)
 416                         rt->rt_rtxcur = tvtohz(&cu->cu_wait);
 417                 retransmit_time = next_sendtime = rt->rt_rtxcur;
 418         } else {
 419                 rt = NULL;
 420                 retransmit_time = next_sendtime = tvtohz(&cu->cu_wait);
 421         }
 422
 423         starttime = ticks;
 424
 425 call_again:
 426         mtx_assert(&cs->cs_lock, MA_OWNED);
 427
 428         cu->cu_xid++;
 429         xid = cu->cu_xid;
 430
 431 send_again:
 432         mtx_unlock(&cs->cs_lock);
 433
 434         MGETHDR(mreq, M_WAIT, MT_DATA);
 435         KASSERT(cu->cu_mcalllen <= MHLEN, ("RPC header too big"));
 436         bcopy(cu->cu_mcallc, mreq->m_data, cu->cu_mcalllen);
 437         mreq->m_len = cu->cu_mcalllen;
 438
 439         /*
 440          * The XID is the first thing in the request.
 441          */
 442         *mtod(mreq, uint32_t *) = htonl(xid);
 443
 444         xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
 445
 446         if (cu->cu_async == TRUE && args == NULL)
 447                 goto get_reply;
 448
 449         if ((! XDR_PUTINT32(&xdrs, &proc)) ||
 450             (! AUTH_MARSHALL(auth, xid, &xdrs,
 451                 m_copym(args, 0, M_COPYALL, M_WAITOK)))) {
 452                 errp->re_status = stat = RPC_CANTENCODEARGS;
 453                 mtx_lock(&cs->cs_lock);
 454                 goto out;
 455         }
 456         mreq->m_pkthdr.len = m_length(mreq, NULL);
 457
 458         cr->cr_xid = xid;
 459         mtx_lock(&cs->cs_lock);
 460
 461         /*
 462          * Try to get a place in the congestion window.
 463          */
 464         while (cu->cu_sent >= cu->cu_cwnd) {
 465                 cu->cu_cwnd_wait = TRUE;
 466                 error = msleep(&cu->cu_cwnd_wait, &cs->cs_lock,
 467                     cu->cu_waitflag, "rpccwnd", 0);
 468                 if (error) {
 469                         errp->re_errno = error;
 470                         errp->re_status = stat = RPC_CANTSEND;
 471                         goto out;
 472                 }
 473         }
 474         cu->cu_sent += CWNDSCALE;
 475
 476         TAILQ_INSERT_TAIL(&cs->cs_pending, cr, cr_link);
 477         mtx_unlock(&cs->cs_lock);
 478
 479         /*
 480          * sosend consumes mreq.
 481          */
 482         error = sosend(cu->cu_socket, sa, NULL, mreq, NULL, 0, curthread);
 483         mreq = NULL;
 484
 485         /*
 486          * sub-optimal code appears here because we have
 487          * some clock time to spare while the packets are in flight.
 488          * (We assume that this is actually only executed once.)
 489          */
 490         reply_msg.acpted_rply.ar_verf.oa_flavor = AUTH_NULL;
 491         reply_msg.acpted_rply.ar_verf.oa_base = cr->cr_verf;
 492         reply_msg.acpted_rply.ar_verf.oa_length = 0;
 493         reply_msg.acpted_rply.ar_results.where = NULL;
 494         reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
 495
 496         mtx_lock(&cs->cs_lock);
 497         if (error) {
 498                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
 499                 errp->re_errno = error;
 500                 errp->re_status = stat = RPC_CANTSEND;
 501                 cu->cu_sent -= CWNDSCALE;
 502                 if (cu->cu_cwnd_wait) {
 503                         cu->cu_cwnd_wait = FALSE;
 504                         wakeup(&cu->cu_cwnd_wait);
 505                 }
 506                 goto out;
 507         }
 508
 509         /*
 510          * Check to see if we got an upcall while waiting for the
 511          * lock.
 512          */
 513         if (cr->cr_error) {
 514                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
 515                 errp->re_errno = cr->cr_error;
 516                 errp->re_status = stat = RPC_CANTRECV;
 517                 cu->cu_sent -= CWNDSCALE;
 518                 if (cu->cu_cwnd_wait) {
 519                         cu->cu_cwnd_wait = FALSE;
 520                         wakeup(&cu->cu_cwnd_wait);
 521                 }
 522                 goto out;
 523         }
 524         if (cr->cr_mrep) {
 525                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
 526                 cu->cu_sent -= CWNDSCALE;
 527                 if (cu->cu_cwnd_wait) {
 528                         cu->cu_cwnd_wait = FALSE;
 529                         wakeup(&cu->cu_cwnd_wait);
 530                 }
 531                 goto got_reply;
 532         }
 533
 534         /*
 535          * Hack to provide rpc-based message passing
 536          */
 537         if (timeout == 0) {
 538                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
 539                 errp->re_status = stat = RPC_TIMEDOUT;
 540                 cu->cu_sent -= CWNDSCALE;
 541                 if (cu->cu_cwnd_wait) {
 542                         cu->cu_cwnd_wait = FALSE;
 543                         wakeup(&cu->cu_cwnd_wait);
 544                 }
 545                 goto out;
 546         }
 547
 548 get_reply:
 549         for (;;) {
 550                 /* Decide how long to wait. */
 551                 if (next_sendtime < timeout)
 552                         tv = next_sendtime;
 553                 else
 554                         tv = timeout;
 555                 tv -= time_waited;
 556
 557                 if (tv > 0) {
 558                         if (cu->cu_closing || cu->cu_closed) {
 559                                 error = 0;
 560                                 cr->cr_error = ESHUTDOWN;
 561                         } else {
 562                                 error = msleep(cr, &cs->cs_lock,
 563                                     cu->cu_waitflag, cu->cu_waitchan, tv);
 564                         }
 565                 } else {
 566                         error = EWOULDBLOCK;
 567                 }
 568
 569                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
 570                 cu->cu_sent -= CWNDSCALE;
 571                 if (cu->cu_cwnd_wait) {
 572                         cu->cu_cwnd_wait = FALSE;
 573                         wakeup(&cu->cu_cwnd_wait);
 574                 }
 575
 576                 if (!error) {
 577                         /*
 578                          * We were woken up by the upcall.  If the
 579                          * upcall had a receive error, report that,
 580                          * otherwise we have a reply.
 581                          */
 582                         if (cr->cr_error) {
 583                                 errp->re_errno = cr->cr_error;
 584                                 errp->re_status = stat = RPC_CANTRECV;
 585                                 goto out;
 586                         }
 587
 588                         cu->cu_cwnd += (CWNDSCALE * CWNDSCALE
 589                             + cu->cu_cwnd / 2) / cu->cu_cwnd;
 590                         if (cu->cu_cwnd > MAXCWND)
 591                                 cu->cu_cwnd = MAXCWND;
 592
 593                         if (rt) {
 594                                 /*
 595                                  * Add one to the time since a tick
 596                                  * count of N means that the actual
 597                                  * time taken was somewhere between N
 598                                  * and N+1.
 599                                  */
 600                                 rtt = ticks - starttime + 1;
 601
 602                                 /*
 603                                  * Update our estimate of the round
 604                                  * trip time using roughly the
 605                                  * algorithm described in RFC
 606                                  * 2988. Given an RTT sample R:
 607                                  *
 608                                  * RTTVAR = (1-beta) * RTTVAR + beta * |SRTT-R|
 609                                  * SRTT = (1-alpha) * SRTT + alpha * R
 610                                  *
 611                                  * where alpha = 0.125 and beta = 0.25.
 612                                  *
 613                                  * The initial retransmit timeout is
 614                                  * SRTT + 4*RTTVAR and doubles on each
 615                                  * retransmision.
 616                                  */
 617                                 if (rt->rt_srtt == 0) {
 618                                         rt->rt_srtt = rtt;
 619                                         rt->rt_deviate = rtt / 2;
 620                                 } else {
 621                                         int32_t error = rtt - rt->rt_srtt;
 622                                         rt->rt_srtt += error / 8;
 623                                         error = abs(error) - rt->rt_deviate;
 624                                         rt->rt_deviate += error / 4;
 625                                 }
 626                                 rt->rt_rtxcur = rt->rt_srtt + 4*rt->rt_deviate;
 627                         }
 628
 629                         break;
 630                 }
 631
 632                 /*
 633                  * The sleep returned an error so our request is still
 634                  * on the list. If we got EWOULDBLOCK, we may want to
 635                  * re-send the request.
 636                  */
 637                 if (error != EWOULDBLOCK) {
 638                         errp->re_errno = error;
 639                         if (error == EINTR)
 640                                 errp->re_status = stat = RPC_INTR;
 641                         else
 642                                 errp->re_status = stat = RPC_CANTRECV;
 643                         goto out;
 644                 }
 645
 646                 time_waited = ticks - starttime;
 647
 648                 /* Check for timeout. */
 649                 if (time_waited > timeout) {
 650                         errp->re_errno = EWOULDBLOCK;
 651                         errp->re_status = stat = RPC_TIMEDOUT;
 652                         goto out;
 653                 }
 654
 655                 /* Retransmit if necessary. */
 656                 if (time_waited >= next_sendtime) {
 657                         cu->cu_cwnd /= 2;
 658                         if (cu->cu_cwnd < CWNDSCALE)
 659                                 cu->cu_cwnd = CWNDSCALE;
 660                         if (ext && ext->rc_feedback) {
 661                                 mtx_unlock(&cs->cs_lock);
 662                                 if (retrans == 0)
 663                                         ext->rc_feedback(FEEDBACK_REXMIT1,
 664                                             proc, ext->rc_feedback_arg);
 665                                 else
 666                                         ext->rc_feedback(FEEDBACK_REXMIT2,
 667                                             proc, ext->rc_feedback_arg);
 668                                 mtx_lock(&cs->cs_lock);
 669                         }
 670                         if (cu->cu_closing || cu->cu_closed) {
 671                                 errp->re_errno = ESHUTDOWN;
 672                                 errp->re_status = stat = RPC_CANTRECV;
 673                                 goto out;
 674                         }
 675                         retrans++;
 676                         /* update retransmit_time */
 677                         if (retransmit_time < RPC_MAX_BACKOFF * hz)
 678                                 retransmit_time = 2 * retransmit_time;
 679                         next_sendtime += retransmit_time;
 680                         goto send_again;
 681                 }
 682                 TAILQ_INSERT_TAIL(&cs->cs_pending, cr, cr_link);
 683         }
 684
 685 got_reply:
 686         /*
 687          * Now decode and validate the response. We need to drop the
 688          * lock since xdr_replymsg may end up sleeping in malloc.
 689          */
 690         mtx_unlock(&cs->cs_lock);
 691
 692         if (ext && ext->rc_feedback)
 693                 ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
 694
 695         xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
 696         ok = xdr_replymsg(&xdrs, &reply_msg);
 697         cr->cr_mrep = NULL;
 698
 699         if (ok) {
 700                 if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
 701                     (reply_msg.acpted_rply.ar_stat == SUCCESS))
 702                         errp->re_status = stat = RPC_SUCCESS;
 703                 else
 704                         stat = _seterr_reply(&reply_msg, &(cu->cu_error));
 705
 706                 if (errp->re_status == RPC_SUCCESS) {
 707                         results = xdrmbuf_getall(&xdrs);
 708                         if (! AUTH_VALIDATE(auth, xid,
 709                                 &reply_msg.acpted_rply.ar_verf,
 710                                 &results)) {
 711                                 errp->re_status = stat = RPC_AUTHERROR;
 712                                 errp->re_why = AUTH_INVALIDRESP;
 713                                 if (retrans &&
 714                                     auth->ah_cred.oa_flavor == RPCSEC_GSS) {
 715                                         /*
 716                                          * If we retransmitted, its
 717                                          * possible that we will
 718                                          * receive a reply for one of
 719                                          * the earlier transmissions
 720                                          * (which will use an older
 721                                          * RPCSEC_GSS sequence
 722                                          * number). In this case, just
 723                                          * go back and listen for a
 724                                          * new reply. We could keep a
 725                                          * record of all the seq
 726                                          * numbers we have transmitted
 727                                          * so far so that we could
 728                                          * accept a reply for any of
 729                                          * them here.
 730                                          */
 731                                         XDR_DESTROY(&xdrs);
 732                                         mtx_lock(&cs->cs_lock);
 733                                         TAILQ_INSERT_TAIL(&cs->cs_pending,
 734                                             cr, cr_link);
 735                                         cr->cr_mrep = NULL;
 736                                         goto get_reply;
 737                                 }
 738                         } else {
 739                                 *resultsp = results;
 740                         }
 741                 }               /* end successful completion */
 742                 /*
 743                  * If unsuccesful AND error is an authentication error
 744                  * then refresh credentials and try again, else break
 745                  */
 746                 else if (stat == RPC_AUTHERROR)
 747                         /* maybe our credentials need to be refreshed ... */
 748                         if (nrefreshes > 0 &&
 749                             AUTH_REFRESH(auth, &reply_msg)) {
 750                                 nrefreshes--;
 751                                 XDR_DESTROY(&xdrs);
 752                                 mtx_lock(&cs->cs_lock);
 753                                 goto call_again;
 754                         }
 755                 /* end of unsuccessful completion */
 756         }       /* end of valid reply message */
 757         else {
 758                 errp->re_status = stat = RPC_CANTDECODERES;
 759
 760         }
 761         XDR_DESTROY(&xdrs);
 762         mtx_lock(&cs->cs_lock);
 763 out:
 764         mtx_assert(&cs->cs_lock, MA_OWNED);
 765
 766         if (mreq)
 767                 m_freem(mreq);
 768         if (cr->cr_mrep)
 769                 m_freem(cr->cr_mrep);
 770
 771         cu->cu_threads--;
 772         if (cu->cu_closing)
 773                 wakeup(cu);
 774
 775         mtx_unlock(&cs->cs_lock);
 776
 777         if (auth && stat != RPC_SUCCESS)
 778                 AUTH_VALIDATE(auth, xid, NULL, NULL);
 779
 780         free(cr, M_RPC);
 781
 782         return (stat);
 783 }
 784
 785 static void
 786 clnt_dg_geterr(CLIENT *cl, struct rpc_err *errp)
 787 {
 788         struct cu_data *cu = (struct cu_data *)cl->cl_private;
 789
 790         *errp = cu->cu_error;
 791 }
 792
 793 static bool_t
 794 clnt_dg_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
 795 {
 796         XDR xdrs;
 797         bool_t dummy;
 798
 799         xdrs.x_op = XDR_FREE;
 800         dummy = (*xdr_res)(&xdrs, res_ptr);
 801
 802         return (dummy);
 803 }
 804
 805 /*ARGSUSED*/
 806 static void
 807 clnt_dg_abort(CLIENT *h)
 808 {
 809 }
 810
 811 static bool_t
 812 clnt_dg_control(CLIENT *cl, u_int request, void *info)
 813 {
 814         struct cu_data *cu = (struct cu_data *)cl->cl_private;
 815         struct cu_socket *cs;
 816         struct sockaddr *addr;
 817
 818         cs = cu->cu_socket->so_rcv.sb_upcallarg;
 819         mtx_lock(&cs->cs_lock);
 820
 821         switch (request) {
 822         case CLSET_FD_CLOSE:
 823                 cu->cu_closeit = TRUE;
 824                 mtx_unlock(&cs->cs_lock);
 825                 return (TRUE);
 826         case CLSET_FD_NCLOSE:
 827                 cu->cu_closeit = FALSE;
 828                 mtx_unlock(&cs->cs_lock);
 829                 return (TRUE);
 830         }
 831
 832         /* for other requests which use info */
 833         if (info == NULL) {
 834                 mtx_unlock(&cs->cs_lock);
 835                 return (FALSE);
 836         }
 837         switch (request) {
 838         case CLSET_TIMEOUT:
 839                 if (time_not_ok((struct timeval *)info)) {
 840                         mtx_unlock(&cs->cs_lock);
 841                         return (FALSE);
 842                 }
 843                 cu->cu_total = *(struct timeval *)info;
 844                 break;
 845         case CLGET_TIMEOUT:
 846                 *(struct timeval *)info = cu->cu_total;
 847                 break;
 848         case CLSET_RETRY_TIMEOUT:
 849                 if (time_not_ok((struct timeval *)info)) {
 850                         mtx_unlock(&cs->cs_lock);
 851                         return (FALSE);
 852                 }
 853                 cu->cu_wait = *(struct timeval *)info;
 854                 break;
 855         case CLGET_RETRY_TIMEOUT:
 856                 *(struct timeval *)info = cu->cu_wait;
 857                 break;
 858         case CLGET_SVC_ADDR:
 859                 /*
 860                  * Slightly different semantics to userland - we use
 861                  * sockaddr instead of netbuf.
 862                  */
 863                 memcpy(info, &cu->cu_raddr, cu->cu_raddr.ss_len);
 864                 break;
 865         case CLSET_SVC_ADDR:            /* set to new address */
 866                 addr = (struct sockaddr *)info;
 867                 (void) memcpy(&cu->cu_raddr, addr, addr->sa_len);
 868                 break;
 869         case CLGET_XID:
 870                 *(uint32_t *)info = cu->cu_xid;
 871                 break;
 872
 873         case CLSET_XID:
 874                 /* This will set the xid of the NEXT call */
 875                 /* decrement by 1 as clnt_dg_call() increments once */
 876                 cu->cu_xid = *(uint32_t *)info - 1;
 877                 break;
 878
 879         case CLGET_VERS:
 880                 /*
 881                  * This RELIES on the information that, in the call body,
 882                  * the version number field is the fifth field from the
 883                  * begining of the RPC header. MUST be changed if the
 884                  * call_struct is changed
 885                  */
 886                 *(uint32_t *)info =
 887                     ntohl(*(uint32_t *)(void *)(cu->cu_mcallc +
 888                     4 * BYTES_PER_XDR_UNIT));
 889                 break;
 890
 891         case CLSET_VERS:
 892                 *(uint32_t *)(void *)(cu->cu_mcallc + 4 * BYTES_PER_XDR_UNIT)
 893                         = htonl(*(uint32_t *)info);
 894                 break;
 895
 896         case CLGET_PROG:
 897                 /*
 898                  * This RELIES on the information that, in the call body,
 899                  * the program number field is the fourth field from the
 900                  * begining of the RPC header. MUST be changed if the
 901                  * call_struct is changed
 902                  */
 903                 *(uint32_t *)info =
 904                     ntohl(*(uint32_t *)(void *)(cu->cu_mcallc +
 905                     3 * BYTES_PER_XDR_UNIT));
 906                 break;
 907
 908         case CLSET_PROG:
 909                 *(uint32_t *)(void *)(cu->cu_mcallc + 3 * BYTES_PER_XDR_UNIT)
 910                         = htonl(*(uint32_t *)info);
 911                 break;
 912         case CLSET_ASYNC:
 913                 cu->cu_async = *(int *)info;
 914                 break;
 915         case CLSET_CONNECT:
 916                 cu->cu_connect = *(int *)info;
 917                 break;
 918         case CLSET_WAITCHAN:
 919                 cu->cu_waitchan = (const char *)info;
 920                 break;
 921         case CLGET_WAITCHAN:
 922                 *(const char **) info = cu->cu_waitchan;
 923                 break;
 924         case CLSET_INTERRUPTIBLE:
 925                 if (*(int *) info)
 926                         cu->cu_waitflag = PCATCH;
 927                 else
 928                         cu->cu_waitflag = 0;
 929                 break;
 930         case CLGET_INTERRUPTIBLE:
 931                 if (cu->cu_waitflag)
 932                         *(int *) info = TRUE;
 933                 else
 934                         *(int *) info = FALSE;
 935                 break;
 936         default:
 937                 mtx_unlock(&cs->cs_lock);
 938                 return (FALSE);
 939         }
 940         mtx_unlock(&cs->cs_lock);
 941         return (TRUE);
 942 }
 943
 944 static void
 945 clnt_dg_close(CLIENT *cl)
 946 {
 947         struct cu_data *cu = (struct cu_data *)cl->cl_private;
 948         struct cu_socket *cs;
 949         struct cu_request *cr;
 950
 951         cs = cu->cu_socket->so_rcv.sb_upcallarg;
 952         mtx_lock(&cs->cs_lock);
 953
 954         if (cu->cu_closed) {
 955                 mtx_unlock(&cs->cs_lock);
 956                 return;
 957         }
 958
 959         if (cu->cu_closing) {
 960                 while (cu->cu_closing)
 961                         msleep(cu, &cs->cs_lock, 0, "rpcclose", 0);
 962                 KASSERT(cu->cu_closed, ("client should be closed"));
 963                 mtx_unlock(&cs->cs_lock);
 964                 return;
 965         }
 966
 967         /*
 968          * Abort any pending requests and wait until everyone
 969          * has finished with clnt_vc_call.
 970          */
 971         cu->cu_closing = TRUE;
 972         TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
 973                 if (cr->cr_client == cl) {
 974                         cr->cr_xid = 0;
 975                         cr->cr_error = ESHUTDOWN;
 976                         wakeup(cr);
 977                 }
 978         }
 979
 980         while (cu->cu_threads)
 981                 msleep(cu, &cs->cs_lock, 0, "rpcclose", 0);
 982
 983         cu->cu_closing = FALSE;
 984         cu->cu_closed = TRUE;
 985
 986         mtx_unlock(&cs->cs_lock);
 987         wakeup(cu);
 988 }
 989
 990 static void
 991 clnt_dg_destroy(CLIENT *cl)
 992 {
 993         struct cu_data *cu = (struct cu_data *)cl->cl_private;
 994         struct cu_socket *cs;
 995         struct socket *so = NULL;
 996         bool_t lastsocketref;
 997
 998         cs = cu->cu_socket->so_rcv.sb_upcallarg;
 999         clnt_dg_close(cl);
1000
1001         mtx_lock(&cs->cs_lock);
1002
1003         cs->cs_refs--;
1004         if (cs->cs_refs == 0) {
1005                 mtx_unlock(&cs->cs_lock);
1006                 SOCKBUF_LOCK(&cu->cu_socket->so_rcv);
1007                 soupcall_clear(cu->cu_socket, SO_RCV);
1008                 clnt_dg_upcallsdone(cu->cu_socket, cs);
1009                 SOCKBUF_UNLOCK(&cu->cu_socket->so_rcv);
1010                 mtx_destroy(&cs->cs_lock);
1011                 mem_free(cs, sizeof(*cs));
1012                 lastsocketref = TRUE;
1013         } else {
1014                 mtx_unlock(&cs->cs_lock);
1015                 lastsocketref = FALSE;
1016         }
1017
1018         if (cu->cu_closeit && lastsocketref) {
1019                 so = cu->cu_socket;
1020                 cu->cu_socket = NULL;
1021         }
1022
1023         if (so)
1024                 soclose(so);
1025
1026         if (cl->cl_netid && cl->cl_netid[0])
1027                 mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
1028         if (cl->cl_tp && cl->cl_tp[0])
1029                 mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
1030         mem_free(cu, sizeof (*cu));
1031         mem_free(cl, sizeof (CLIENT));
1032 }
1033
1034 /*
1035  * Make sure that the time is not garbage.  -1 value is allowed.
1036  */
1037 static bool_t
1038 time_not_ok(struct timeval *t)
1039 {
1040         return (t->tv_sec < -1 || t->tv_sec > 100000000 ||
1041                 t->tv_usec < -1 || t->tv_usec > 1000000);
1042 }
1043
1044 int
1045 clnt_dg_soupcall(struct socket *so, void *arg, int waitflag)
1046 {
1047         struct cu_socket *cs = (struct cu_socket *) arg;
1048         struct uio uio;
1049         struct mbuf *m;
1050         struct mbuf *control;
1051         struct cu_request *cr;
1052         int error, rcvflag, foundreq;
1053         uint32_t xid;
1054
1055         cs->cs_upcallrefs++;
1056         uio.uio_resid = 1000000000;
1057         uio.uio_td = curthread;
1058         do {
1059                 SOCKBUF_UNLOCK(&so->so_rcv);
1060                 m = NULL;
1061                 control = NULL;
1062                 rcvflag = MSG_DONTWAIT;
1063                 error = soreceive(so, NULL, &uio, &m, &control, &rcvflag);
1064                 if (control)
1065                         m_freem(control);
1066                 SOCKBUF_LOCK(&so->so_rcv);
1067
1068                 if (error == EWOULDBLOCK)
1069                         break;
1070
1071                 /*
1072                  * If there was an error, wake up all pending
1073                  * requests.
1074                  */
1075                 if (error) {
1076                         mtx_lock(&cs->cs_lock);
1077                         TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
1078                                 cr->cr_xid = 0;
1079                                 cr->cr_error = error;
1080                                 wakeup(cr);
1081                         }
1082                         mtx_unlock(&cs->cs_lock);
1083                         break;
1084                 }
1085
1086                 /*
1087                  * The XID is in the first uint32_t of the reply.
1088                  */
1089                 if (m->m_len < sizeof(xid) && m_length(m, NULL) < sizeof(xid)) {
1090                         /*
1091                          * Should never happen.
1092                          */
1093                         m_freem(m);
1094                         continue;
1095                 }
1096
1097                 m_copydata(m, 0, sizeof(xid), (char *)&xid);
1098                 xid = ntohl(xid);
1099
1100                 /*
1101                  * Attempt to match this reply with a pending request.
1102                  */
1103                 mtx_lock(&cs->cs_lock);
1104                 foundreq = 0;
1105                 TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
1106                         if (cr->cr_xid == xid) {
1107                                 /*
1108                                  * This one matches. We leave the
1109                                  * reply mbuf in cr->cr_mrep. Set the
1110                                  * XID to zero so that we will ignore
1111                                  * any duplicated replies that arrive
1112                                  * before clnt_dg_call removes it from
1113                                  * the queue.
1114                                  */
1115                                 cr->cr_xid = 0;
1116                                 cr->cr_mrep = m;
1117                                 cr->cr_error = 0;
1118                                 foundreq = 1;
1119                                 wakeup(cr);
1120                                 break;
1121                         }
1122                 }
1123                 mtx_unlock(&cs->cs_lock);
1124
1125                 /*
1126                  * If we didn't find the matching request, just drop
1127                  * it - its probably a repeated reply.
1128                  */
1129                 if (!foundreq)
1130                         m_freem(m);
1131         } while (m);
1132         cs->cs_upcallrefs--;
1133         if (cs->cs_upcallrefs < 0)
1134                 panic("rpcdg upcall refcnt");
1135         if (cs->cs_upcallrefs == 0)
1136                 wakeup(&cs->cs_upcallrefs);
1137         return (SU_OK);
1138 }
1139
1140 /*
1141  * Wait for all upcalls in progress to complete.
1142  */
1143 static void
1144 clnt_dg_upcallsdone(struct socket *so, struct cu_socket *cs)
1145 {
1146
1147         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1148
1149         while (cs->cs_upcallrefs > 0)
1150                 (void) msleep(&cs->cs_upcallrefs, SOCKBUF_MTX(&so->so_rcv), 0,
1151                     "rpcdgup", 0);
1152 }