The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/rpc/clnt_dg.c

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    1 /*      $NetBSD: clnt_dg.c,v 1.4 2000/07/14 08:40:41 fvdl Exp $ */
    2 
    3 /*-
    4  * SPDX-License-Identifier: BSD-3-Clause
    5  *
    6  * Copyright (c) 2009, Sun Microsystems, Inc.
    7  * All rights reserved.
    8  *
    9  * Redistribution and use in source and binary forms, with or without 
   10  * modification, are permitted provided that the following conditions are met:
   11  * - Redistributions of source code must retain the above copyright notice, 
   12  *   this list of conditions and the following disclaimer.
   13  * - Redistributions in binary form must reproduce the above copyright notice, 
   14  *   this list of conditions and the following disclaimer in the documentation 
   15  *   and/or other materials provided with the distribution.
   16  * - Neither the name of Sun Microsystems, Inc. nor the names of its 
   17  *   contributors may be used to endorse or promote products derived 
   18  *   from this software without specific prior written permission.
   19  * 
   20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
   21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
   23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
   24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
   25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
   26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
   27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
   28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
   29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
   30  * POSSIBILITY OF SUCH DAMAGE.
   31  */
   32 /*
   33  * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
   34  */
   35 
   36 #if defined(LIBC_SCCS) && !defined(lint)
   37 #ident  "@(#)clnt_dg.c  1.23    94/04/22 SMI"
   38 static char sccsid[] = "@(#)clnt_dg.c 1.19 89/03/16 Copyr 1988 Sun Micro";
   39 #endif
   40 #include <sys/cdefs.h>
   41 __FBSDID("$FreeBSD$");
   42 
   43 /*
   44  * Implements a connectionless client side RPC.
   45  */
   46 
   47 #include <sys/param.h>
   48 #include <sys/systm.h>
   49 #include <sys/kernel.h>
   50 #include <sys/lock.h>
   51 #include <sys/malloc.h>
   52 #include <sys/mbuf.h>
   53 #include <sys/mutex.h>
   54 #include <sys/pcpu.h>
   55 #include <sys/proc.h>
   56 #include <sys/socket.h>
   57 #include <sys/socketvar.h>
   58 #include <sys/time.h>
   59 #include <sys/uio.h>
   60 
   61 #include <net/vnet.h>
   62 
   63 #include <rpc/rpc.h>
   64 #include <rpc/rpc_com.h>
   65 
   66 
   67 #ifdef _FREEFALL_CONFIG
   68 /*
   69  * Disable RPC exponential back-off for FreeBSD.org systems.
   70  */
   71 #define RPC_MAX_BACKOFF         1 /* second */
   72 #else
   73 #define RPC_MAX_BACKOFF         30 /* seconds */
   74 #endif
   75 
   76 static bool_t time_not_ok(struct timeval *);
   77 static enum clnt_stat clnt_dg_call(CLIENT *, struct rpc_callextra *,
   78     rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
   79 static void clnt_dg_geterr(CLIENT *, struct rpc_err *);
   80 static bool_t clnt_dg_freeres(CLIENT *, xdrproc_t, void *);
   81 static void clnt_dg_abort(CLIENT *);
   82 static bool_t clnt_dg_control(CLIENT *, u_int, void *);
   83 static void clnt_dg_close(CLIENT *);
   84 static void clnt_dg_destroy(CLIENT *);
   85 static int clnt_dg_soupcall(struct socket *so, void *arg, int waitflag);
   86 
   87 static const struct clnt_ops clnt_dg_ops = {
   88         .cl_call =      clnt_dg_call,
   89         .cl_abort =     clnt_dg_abort,
   90         .cl_geterr =    clnt_dg_geterr,
   91         .cl_freeres =   clnt_dg_freeres,
   92         .cl_close =     clnt_dg_close,
   93         .cl_destroy =   clnt_dg_destroy,
   94         .cl_control =   clnt_dg_control
   95 };
   96 
   97 static volatile uint32_t rpc_xid = 0;
   98 
   99 /*
  100  * A pending RPC request which awaits a reply. Requests which have
  101  * received their reply will have cr_xid set to zero and cr_mrep to
  102  * the mbuf chain of the reply.
  103  */
  104 struct cu_request {
  105         TAILQ_ENTRY(cu_request) cr_link;
  106         CLIENT                  *cr_client;     /* owner */
  107         uint32_t                cr_xid;         /* XID of request */
  108         struct mbuf             *cr_mrep;       /* reply received by upcall */
  109         int                     cr_error;       /* any error from upcall */
  110         char                    cr_verf[MAX_AUTH_BYTES]; /* reply verf */
  111 };
  112 
  113 TAILQ_HEAD(cu_request_list, cu_request);
  114 
  115 #define MCALL_MSG_SIZE 24
  116 
  117 /*
  118  * This structure is pointed to by the socket buffer's sb_upcallarg
  119  * member. It is separate from the client private data to facilitate
  120  * multiple clients sharing the same socket. The cs_lock mutex is used
  121  * to protect all fields of this structure, the socket's receive
  122  * buffer SOCKBUF_LOCK is used to ensure that exactly one of these
  123  * structures is installed on the socket.
  124  */
  125 struct cu_socket {
  126         struct mtx              cs_lock;
  127         int                     cs_refs;        /* Count of clients */
  128         struct cu_request_list  cs_pending;     /* Requests awaiting replies */
  129         int                     cs_upcallrefs;  /* Refcnt of upcalls in prog.*/
  130 };
  131 
  132 static void clnt_dg_upcallsdone(struct socket *, struct cu_socket *);
  133 
  134 /*
  135  * Private data kept per client handle
  136  */
  137 struct cu_data {
  138         int                     cu_threads;     /* # threads in clnt_vc_call */
  139         bool_t                  cu_closing;     /* TRUE if we are closing */
  140         bool_t                  cu_closed;      /* TRUE if we are closed */
  141         struct socket           *cu_socket;     /* connection socket */
  142         bool_t                  cu_closeit;     /* opened by library */
  143         struct sockaddr_storage cu_raddr;       /* remote address */
  144         int                     cu_rlen;
  145         struct timeval          cu_wait;        /* retransmit interval */
  146         struct timeval          cu_total;       /* total time for the call */
  147         struct rpc_err          cu_error;
  148         uint32_t                cu_xid;
  149         char                    cu_mcallc[MCALL_MSG_SIZE]; /* marshalled callmsg */
  150         size_t                  cu_mcalllen;
  151         size_t                  cu_sendsz;      /* send size */
  152         size_t                  cu_recvsz;      /* recv size */
  153         int                     cu_async;
  154         int                     cu_connect;     /* Use connect(). */
  155         int                     cu_connected;   /* Have done connect(). */
  156         const char              *cu_waitchan;
  157         int                     cu_waitflag;
  158         int                     cu_cwnd;        /* congestion window */
  159         int                     cu_sent;        /* number of in-flight RPCs */
  160         bool_t                  cu_cwnd_wait;
  161 };
  162 
  163 #define CWNDSCALE       256
  164 #define MAXCWND         (32 * CWNDSCALE)
  165 
  166 /*
  167  * Connection less client creation returns with client handle parameters.
  168  * Default options are set, which the user can change using clnt_control().
  169  * fd should be open and bound.
  170  * NB: The rpch->cl_auth is initialized to null authentication.
  171  *      Caller may wish to set this something more useful.
  172  *
  173  * sendsz and recvsz are the maximum allowable packet sizes that can be
  174  * sent and received. Normally they are the same, but they can be
  175  * changed to improve the program efficiency and buffer allocation.
  176  * If they are 0, use the transport default.
  177  *
  178  * If svcaddr is NULL, returns NULL.
  179  */
  180 CLIENT *
  181 clnt_dg_create(
  182         struct socket *so,
  183         struct sockaddr *svcaddr,       /* servers address */
  184         rpcprog_t program,              /* program number */
  185         rpcvers_t version,              /* version number */
  186         size_t sendsz,                  /* buffer recv size */
  187         size_t recvsz)                  /* buffer send size */
  188 {
  189         CLIENT *cl = NULL;              /* client handle */
  190         struct cu_data *cu = NULL;      /* private data */
  191         struct cu_socket *cs = NULL;
  192         struct sockbuf *sb;
  193         struct timeval now;
  194         struct rpc_msg call_msg;
  195         struct __rpc_sockinfo si;
  196         XDR xdrs;
  197         int error;
  198         uint32_t newxid;
  199 
  200         if (svcaddr == NULL) {
  201                 rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
  202                 return (NULL);
  203         }
  204 
  205         if (!__rpc_socket2sockinfo(so, &si)) {
  206                 rpc_createerr.cf_stat = RPC_TLIERROR;
  207                 rpc_createerr.cf_error.re_errno = 0;
  208                 return (NULL);
  209         }
  210 
  211         /*
  212          * Find the receive and the send size
  213          */
  214         sendsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsz);
  215         recvsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsz);
  216         if ((sendsz == 0) || (recvsz == 0)) {
  217                 rpc_createerr.cf_stat = RPC_TLIERROR; /* XXX */
  218                 rpc_createerr.cf_error.re_errno = 0;
  219                 return (NULL);
  220         }
  221 
  222         cl = mem_alloc(sizeof (CLIENT));
  223 
  224         /*
  225          * Should be multiple of 4 for XDR.
  226          */
  227         sendsz = rounddown(sendsz + 3, 4);
  228         recvsz = rounddown(recvsz + 3, 4);
  229         cu = mem_alloc(sizeof (*cu));
  230         cu->cu_threads = 0;
  231         cu->cu_closing = FALSE;
  232         cu->cu_closed = FALSE;
  233         (void) memcpy(&cu->cu_raddr, svcaddr, (size_t)svcaddr->sa_len);
  234         cu->cu_rlen = svcaddr->sa_len;
  235         /* Other values can also be set through clnt_control() */
  236         cu->cu_wait.tv_sec = 3; /* heuristically chosen */
  237         cu->cu_wait.tv_usec = 0;
  238         cu->cu_total.tv_sec = -1;
  239         cu->cu_total.tv_usec = -1;
  240         cu->cu_sendsz = sendsz;
  241         cu->cu_recvsz = recvsz;
  242         cu->cu_async = FALSE;
  243         cu->cu_connect = FALSE;
  244         cu->cu_connected = FALSE;
  245         cu->cu_waitchan = "rpcrecv";
  246         cu->cu_waitflag = 0;
  247         cu->cu_cwnd = MAXCWND / 2;
  248         cu->cu_sent = 0;
  249         cu->cu_cwnd_wait = FALSE;
  250         (void) getmicrotime(&now);
  251         /* Clip at 28bits so that it will not wrap around. */
  252         newxid = __RPC_GETXID(&now) & 0xfffffff;
  253         atomic_cmpset_32(&rpc_xid, 0, newxid);
  254         call_msg.rm_xid = atomic_fetchadd_32(&rpc_xid, 1);
  255         call_msg.rm_call.cb_prog = program;
  256         call_msg.rm_call.cb_vers = version;
  257         xdrmem_create(&xdrs, cu->cu_mcallc, MCALL_MSG_SIZE, XDR_ENCODE);
  258         if (! xdr_callhdr(&xdrs, &call_msg)) {
  259                 rpc_createerr.cf_stat = RPC_CANTENCODEARGS;  /* XXX */
  260                 rpc_createerr.cf_error.re_errno = 0;
  261                 goto err2;
  262         }
  263         cu->cu_mcalllen = XDR_GETPOS(&xdrs);
  264 
  265         /*
  266          * By default, closeit is always FALSE. It is users responsibility
  267          * to do a close on it, else the user may use clnt_control
  268          * to let clnt_destroy do it for him/her.
  269          */
  270         cu->cu_closeit = FALSE;
  271         cu->cu_socket = so;
  272         error = soreserve(so, (u_long)sendsz, (u_long)recvsz);
  273         if (error != 0) {
  274                 rpc_createerr.cf_stat = RPC_FAILED;
  275                 rpc_createerr.cf_error.re_errno = error;
  276                 goto err2;
  277         }
  278 
  279         sb = &so->so_rcv;
  280         SOCKBUF_LOCK(&so->so_rcv);
  281 recheck_socket:
  282         if (sb->sb_upcall) {
  283                 if (sb->sb_upcall != clnt_dg_soupcall) {
  284                         SOCKBUF_UNLOCK(&so->so_rcv);
  285                         printf("clnt_dg_create(): socket already has an incompatible upcall\n");
  286                         goto err2;
  287                 }
  288                 cs = (struct cu_socket *) sb->sb_upcallarg;
  289                 mtx_lock(&cs->cs_lock);
  290                 cs->cs_refs++;
  291                 mtx_unlock(&cs->cs_lock);
  292         } else {
  293                 /*
  294                  * We are the first on this socket - allocate the
  295                  * structure and install it in the socket.
  296                  */
  297                 SOCKBUF_UNLOCK(&so->so_rcv);
  298                 cs = mem_alloc(sizeof(*cs));
  299                 SOCKBUF_LOCK(&so->so_rcv);
  300                 if (sb->sb_upcall) {
  301                         /*
  302                          * We have lost a race with some other client.
  303                          */
  304                         mem_free(cs, sizeof(*cs));
  305                         goto recheck_socket;
  306                 }
  307                 mtx_init(&cs->cs_lock, "cs->cs_lock", NULL, MTX_DEF);
  308                 cs->cs_refs = 1;
  309                 cs->cs_upcallrefs = 0;
  310                 TAILQ_INIT(&cs->cs_pending);
  311                 soupcall_set(so, SO_RCV, clnt_dg_soupcall, cs);
  312         }
  313         SOCKBUF_UNLOCK(&so->so_rcv);
  314 
  315         cl->cl_refs = 1;
  316         cl->cl_ops = &clnt_dg_ops;
  317         cl->cl_private = (caddr_t)(void *)cu;
  318         cl->cl_auth = authnone_create();
  319         cl->cl_tp = NULL;
  320         cl->cl_netid = NULL;
  321         return (cl);
  322 err2:
  323         mem_free(cl, sizeof (CLIENT));
  324         mem_free(cu, sizeof (*cu));
  325 
  326         return (NULL);
  327 }
  328 
  329 static enum clnt_stat
  330 clnt_dg_call(
  331         CLIENT          *cl,            /* client handle */
  332         struct rpc_callextra *ext,      /* call metadata */
  333         rpcproc_t       proc,           /* procedure number */
  334         struct mbuf     *args,          /* pointer to args */
  335         struct mbuf     **resultsp,     /* pointer to results */
  336         struct timeval  utimeout)       /* seconds to wait before giving up */
  337 {
  338         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  339         struct cu_socket *cs;
  340         struct rpc_timers *rt;
  341         AUTH *auth;
  342         struct rpc_err *errp;
  343         enum clnt_stat stat;
  344         XDR xdrs;
  345         struct rpc_msg reply_msg;
  346         bool_t ok;
  347         int retrans;                    /* number of re-transmits so far */
  348         int nrefreshes = 2;             /* number of times to refresh cred */
  349         struct timeval *tvp;
  350         int timeout;
  351         int retransmit_time;
  352         int next_sendtime, starttime, rtt, time_waited, tv = 0;
  353         struct sockaddr *sa;
  354         uint32_t xid = 0;
  355         struct mbuf *mreq = NULL, *results;
  356         struct cu_request *cr;
  357         int error;
  358 
  359         cs = cu->cu_socket->so_rcv.sb_upcallarg;
  360         cr = malloc(sizeof(struct cu_request), M_RPC, M_WAITOK);
  361 
  362         mtx_lock(&cs->cs_lock);
  363 
  364         if (cu->cu_closing || cu->cu_closed) {
  365                 mtx_unlock(&cs->cs_lock);
  366                 free(cr, M_RPC);
  367                 return (RPC_CANTSEND);
  368         }
  369         cu->cu_threads++;
  370 
  371         if (ext) {
  372                 auth = ext->rc_auth;
  373                 errp = &ext->rc_err;
  374         } else {
  375                 auth = cl->cl_auth;
  376                 errp = &cu->cu_error;
  377         }
  378 
  379         cr->cr_client = cl;
  380         cr->cr_mrep = NULL;
  381         cr->cr_error = 0;
  382 
  383         if (cu->cu_total.tv_usec == -1) {
  384                 tvp = &utimeout; /* use supplied timeout */
  385         } else {
  386                 tvp = &cu->cu_total; /* use default timeout */
  387         }
  388         if (tvp->tv_sec || tvp->tv_usec)
  389                 timeout = tvtohz(tvp);
  390         else
  391                 timeout = 0;
  392 
  393         if (cu->cu_connect && !cu->cu_connected) {
  394                 mtx_unlock(&cs->cs_lock);
  395                 error = soconnect(cu->cu_socket,
  396                     (struct sockaddr *)&cu->cu_raddr, curthread);
  397                 mtx_lock(&cs->cs_lock);
  398                 if (error) {
  399                         errp->re_errno = error;
  400                         errp->re_status = stat = RPC_CANTSEND;
  401                         goto out;
  402                 }
  403                 cu->cu_connected = 1;
  404         }
  405         if (cu->cu_connected)
  406                 sa = NULL;
  407         else
  408                 sa = (struct sockaddr *)&cu->cu_raddr;
  409         time_waited = 0;
  410         retrans = 0;
  411         if (ext && ext->rc_timers) {
  412                 rt = ext->rc_timers;
  413                 if (!rt->rt_rtxcur)
  414                         rt->rt_rtxcur = tvtohz(&cu->cu_wait);
  415                 retransmit_time = next_sendtime = rt->rt_rtxcur;
  416         } else {
  417                 rt = NULL;
  418                 retransmit_time = next_sendtime = tvtohz(&cu->cu_wait);
  419         }
  420 
  421         starttime = ticks;
  422 
  423 call_again:
  424         mtx_assert(&cs->cs_lock, MA_OWNED);
  425 
  426         xid = atomic_fetchadd_32(&rpc_xid, 1);
  427 
  428 send_again:
  429         mtx_unlock(&cs->cs_lock);
  430 
  431         mreq = m_gethdr(M_WAITOK, MT_DATA);
  432         KASSERT(cu->cu_mcalllen <= MHLEN, ("RPC header too big"));
  433         bcopy(cu->cu_mcallc, mreq->m_data, cu->cu_mcalllen);
  434         mreq->m_len = cu->cu_mcalllen;
  435 
  436         /*
  437          * The XID is the first thing in the request.
  438          */
  439         *mtod(mreq, uint32_t *) = htonl(xid);
  440 
  441         xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
  442 
  443         if (cu->cu_async == TRUE && args == NULL)
  444                 goto get_reply;
  445 
  446         if ((! XDR_PUTINT32(&xdrs, &proc)) ||
  447             (! AUTH_MARSHALL(auth, xid, &xdrs,
  448                 m_copym(args, 0, M_COPYALL, M_WAITOK)))) {
  449                 errp->re_status = stat = RPC_CANTENCODEARGS;
  450                 mtx_lock(&cs->cs_lock);
  451                 goto out;
  452         }
  453         mreq->m_pkthdr.len = m_length(mreq, NULL);
  454 
  455         cr->cr_xid = xid;
  456         mtx_lock(&cs->cs_lock);
  457 
  458         /*
  459          * Try to get a place in the congestion window.
  460          */
  461         while (cu->cu_sent >= cu->cu_cwnd) {
  462                 cu->cu_cwnd_wait = TRUE;
  463                 error = msleep(&cu->cu_cwnd_wait, &cs->cs_lock,
  464                     cu->cu_waitflag, "rpccwnd", 0);
  465                 if (error) {
  466                         errp->re_errno = error;
  467                         if (error == EINTR || error == ERESTART)
  468                                 errp->re_status = stat = RPC_INTR;
  469                         else
  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 || error == ERESTART)
  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                 cu->cu_sent += CWNDSCALE;
  683                 TAILQ_INSERT_TAIL(&cs->cs_pending, cr, cr_link);
  684         }
  685 
  686 got_reply:
  687         /*
  688          * Now decode and validate the response. We need to drop the
  689          * lock since xdr_replymsg may end up sleeping in malloc.
  690          */
  691         mtx_unlock(&cs->cs_lock);
  692 
  693         if (ext && ext->rc_feedback)
  694                 ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
  695 
  696         xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
  697         ok = xdr_replymsg(&xdrs, &reply_msg);
  698         cr->cr_mrep = NULL;
  699 
  700         if (ok) {
  701                 if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
  702                     (reply_msg.acpted_rply.ar_stat == SUCCESS))
  703                         errp->re_status = stat = RPC_SUCCESS;
  704                 else
  705                         stat = _seterr_reply(&reply_msg, &(cu->cu_error));
  706 
  707                 if (errp->re_status == RPC_SUCCESS) {
  708                         results = xdrmbuf_getall(&xdrs);
  709                         if (! AUTH_VALIDATE(auth, xid,
  710                                 &reply_msg.acpted_rply.ar_verf,
  711                                 &results)) {
  712                                 errp->re_status = stat = RPC_AUTHERROR;
  713                                 errp->re_why = AUTH_INVALIDRESP;
  714                                 if (retrans &&
  715                                     auth->ah_cred.oa_flavor == RPCSEC_GSS) {
  716                                         /*
  717                                          * If we retransmitted, its
  718                                          * possible that we will
  719                                          * receive a reply for one of
  720                                          * the earlier transmissions
  721                                          * (which will use an older
  722                                          * RPCSEC_GSS sequence
  723                                          * number). In this case, just
  724                                          * go back and listen for a
  725                                          * new reply. We could keep a
  726                                          * record of all the seq
  727                                          * numbers we have transmitted
  728                                          * so far so that we could
  729                                          * accept a reply for any of
  730                                          * them here.
  731                                          */
  732                                         XDR_DESTROY(&xdrs);
  733                                         mtx_lock(&cs->cs_lock);
  734                                         cu->cu_sent += CWNDSCALE;
  735                                         TAILQ_INSERT_TAIL(&cs->cs_pending,
  736                                             cr, cr_link);
  737                                         cr->cr_mrep = NULL;
  738                                         goto get_reply;
  739                                 }
  740                         } else {
  741                                 *resultsp = results;
  742                         }
  743                 }               /* end successful completion */
  744                 /*
  745                  * If unsuccessful AND error is an authentication error
  746                  * then refresh credentials and try again, else break
  747                  */
  748                 else if (stat == RPC_AUTHERROR)
  749                         /* maybe our credentials need to be refreshed ... */
  750                         if (nrefreshes > 0 &&
  751                             AUTH_REFRESH(auth, &reply_msg)) {
  752                                 nrefreshes--;
  753                                 XDR_DESTROY(&xdrs);
  754                                 mtx_lock(&cs->cs_lock);
  755                                 goto call_again;
  756                         }
  757                 /* end of unsuccessful completion */
  758         }       /* end of valid reply message */
  759         else {
  760                 errp->re_status = stat = RPC_CANTDECODERES;
  761 
  762         }
  763         XDR_DESTROY(&xdrs);
  764         mtx_lock(&cs->cs_lock);
  765 out:
  766         mtx_assert(&cs->cs_lock, MA_OWNED);
  767 
  768         if (mreq)
  769                 m_freem(mreq);
  770         if (cr->cr_mrep)
  771                 m_freem(cr->cr_mrep);
  772 
  773         cu->cu_threads--;
  774         if (cu->cu_closing)
  775                 wakeup(cu);
  776                 
  777         mtx_unlock(&cs->cs_lock);
  778 
  779         if (auth && stat != RPC_SUCCESS)
  780                 AUTH_VALIDATE(auth, xid, NULL, NULL);
  781 
  782         free(cr, M_RPC);
  783 
  784         return (stat);
  785 }
  786 
  787 static void
  788 clnt_dg_geterr(CLIENT *cl, struct rpc_err *errp)
  789 {
  790         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  791 
  792         *errp = cu->cu_error;
  793 }
  794 
  795 static bool_t
  796 clnt_dg_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
  797 {
  798         XDR xdrs;
  799         bool_t dummy;
  800 
  801         xdrs.x_op = XDR_FREE;
  802         dummy = (*xdr_res)(&xdrs, res_ptr);
  803 
  804         return (dummy);
  805 }
  806 
  807 /*ARGSUSED*/
  808 static void
  809 clnt_dg_abort(CLIENT *h)
  810 {
  811 }
  812 
  813 static bool_t
  814 clnt_dg_control(CLIENT *cl, u_int request, void *info)
  815 {
  816         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  817         struct cu_socket *cs;
  818         struct sockaddr *addr;
  819 
  820         cs = cu->cu_socket->so_rcv.sb_upcallarg;
  821         mtx_lock(&cs->cs_lock);
  822 
  823         switch (request) {
  824         case CLSET_FD_CLOSE:
  825                 cu->cu_closeit = TRUE;
  826                 mtx_unlock(&cs->cs_lock);
  827                 return (TRUE);
  828         case CLSET_FD_NCLOSE:
  829                 cu->cu_closeit = FALSE;
  830                 mtx_unlock(&cs->cs_lock);
  831                 return (TRUE);
  832         }
  833 
  834         /* for other requests which use info */
  835         if (info == NULL) {
  836                 mtx_unlock(&cs->cs_lock);
  837                 return (FALSE);
  838         }
  839         switch (request) {
  840         case CLSET_TIMEOUT:
  841                 if (time_not_ok((struct timeval *)info)) {
  842                         mtx_unlock(&cs->cs_lock);
  843                         return (FALSE);
  844                 }
  845                 cu->cu_total = *(struct timeval *)info;
  846                 break;
  847         case CLGET_TIMEOUT:
  848                 *(struct timeval *)info = cu->cu_total;
  849                 break;
  850         case CLSET_RETRY_TIMEOUT:
  851                 if (time_not_ok((struct timeval *)info)) {
  852                         mtx_unlock(&cs->cs_lock);
  853                         return (FALSE);
  854                 }
  855                 cu->cu_wait = *(struct timeval *)info;
  856                 break;
  857         case CLGET_RETRY_TIMEOUT:
  858                 *(struct timeval *)info = cu->cu_wait;
  859                 break;
  860         case CLGET_SVC_ADDR:
  861                 /*
  862                  * Slightly different semantics to userland - we use
  863                  * sockaddr instead of netbuf.
  864                  */
  865                 memcpy(info, &cu->cu_raddr, cu->cu_raddr.ss_len);
  866                 break;
  867         case CLSET_SVC_ADDR:            /* set to new address */
  868                 addr = (struct sockaddr *)info;
  869                 (void) memcpy(&cu->cu_raddr, addr, addr->sa_len);
  870                 break;
  871         case CLGET_XID:
  872                 *(uint32_t *)info = atomic_load_32(&rpc_xid);
  873                 break;
  874 
  875         case CLSET_XID:
  876                 /* This will set the xid of the NEXT call */
  877                 /* decrement by 1 as clnt_dg_call() increments once */
  878                 atomic_store_32(&rpc_xid, *(uint32_t *)info - 1);
  879                 break;
  880 
  881         case CLGET_VERS:
  882                 /*
  883                  * This RELIES on the information that, in the call body,
  884                  * the version number field is the fifth field from the
  885                  * beginning of the RPC header. MUST be changed if the
  886                  * call_struct is changed
  887                  */
  888                 *(uint32_t *)info =
  889                     ntohl(*(uint32_t *)(void *)(cu->cu_mcallc +
  890                     4 * BYTES_PER_XDR_UNIT));
  891                 break;
  892 
  893         case CLSET_VERS:
  894                 *(uint32_t *)(void *)(cu->cu_mcallc + 4 * BYTES_PER_XDR_UNIT)
  895                         = htonl(*(uint32_t *)info);
  896                 break;
  897 
  898         case CLGET_PROG:
  899                 /*
  900                  * This RELIES on the information that, in the call body,
  901                  * the program number field is the fourth field from the
  902                  * beginning of the RPC header. MUST be changed if the
  903                  * call_struct is changed
  904                  */
  905                 *(uint32_t *)info =
  906                     ntohl(*(uint32_t *)(void *)(cu->cu_mcallc +
  907                     3 * BYTES_PER_XDR_UNIT));
  908                 break;
  909 
  910         case CLSET_PROG:
  911                 *(uint32_t *)(void *)(cu->cu_mcallc + 3 * BYTES_PER_XDR_UNIT)
  912                         = htonl(*(uint32_t *)info);
  913                 break;
  914         case CLSET_ASYNC:
  915                 cu->cu_async = *(int *)info;
  916                 break;
  917         case CLSET_CONNECT:
  918                 cu->cu_connect = *(int *)info;
  919                 break;
  920         case CLSET_WAITCHAN:
  921                 cu->cu_waitchan = (const char *)info;
  922                 break;
  923         case CLGET_WAITCHAN:
  924                 *(const char **) info = cu->cu_waitchan;
  925                 break;
  926         case CLSET_INTERRUPTIBLE:
  927                 if (*(int *) info)
  928                         cu->cu_waitflag = PCATCH;
  929                 else
  930                         cu->cu_waitflag = 0;
  931                 break;
  932         case CLGET_INTERRUPTIBLE:
  933                 if (cu->cu_waitflag)
  934                         *(int *) info = TRUE;
  935                 else
  936                         *(int *) info = FALSE;
  937                 break;
  938         default:
  939                 mtx_unlock(&cs->cs_lock);
  940                 return (FALSE);
  941         }
  942         mtx_unlock(&cs->cs_lock);
  943         return (TRUE);
  944 }
  945 
  946 static void
  947 clnt_dg_close(CLIENT *cl)
  948 {
  949         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  950         struct cu_socket *cs;
  951         struct cu_request *cr;
  952 
  953         cs = cu->cu_socket->so_rcv.sb_upcallarg;
  954         mtx_lock(&cs->cs_lock);
  955 
  956         if (cu->cu_closed) {
  957                 mtx_unlock(&cs->cs_lock);
  958                 return;
  959         }
  960 
  961         if (cu->cu_closing) {
  962                 while (cu->cu_closing)
  963                         msleep(cu, &cs->cs_lock, 0, "rpcclose", 0);
  964                 KASSERT(cu->cu_closed, ("client should be closed"));
  965                 mtx_unlock(&cs->cs_lock);
  966                 return;
  967         }
  968 
  969         /*
  970          * Abort any pending requests and wait until everyone
  971          * has finished with clnt_vc_call.
  972          */
  973         cu->cu_closing = TRUE;
  974         TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
  975                 if (cr->cr_client == cl) {
  976                         cr->cr_xid = 0;
  977                         cr->cr_error = ESHUTDOWN;
  978                         wakeup(cr);
  979                 }
  980         }
  981 
  982         while (cu->cu_threads)
  983                 msleep(cu, &cs->cs_lock, 0, "rpcclose", 0);
  984 
  985         cu->cu_closing = FALSE;
  986         cu->cu_closed = TRUE;
  987 
  988         mtx_unlock(&cs->cs_lock);
  989         wakeup(cu);
  990 }
  991 
  992 static void
  993 clnt_dg_destroy(CLIENT *cl)
  994 {
  995         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  996         struct cu_socket *cs;
  997         struct socket *so = NULL;
  998         bool_t lastsocketref;
  999 
 1000         cs = cu->cu_socket->so_rcv.sb_upcallarg;
 1001         clnt_dg_close(cl);
 1002 
 1003         SOCKBUF_LOCK(&cu->cu_socket->so_rcv);
 1004         mtx_lock(&cs->cs_lock);
 1005 
 1006         cs->cs_refs--;
 1007         if (cs->cs_refs == 0) {
 1008                 mtx_unlock(&cs->cs_lock);
 1009                 soupcall_clear(cu->cu_socket, SO_RCV);
 1010                 clnt_dg_upcallsdone(cu->cu_socket, cs);
 1011                 SOCKBUF_UNLOCK(&cu->cu_socket->so_rcv);
 1012                 mtx_destroy(&cs->cs_lock);
 1013                 mem_free(cs, sizeof(*cs));
 1014                 lastsocketref = TRUE;
 1015         } else {
 1016                 mtx_unlock(&cs->cs_lock);
 1017                 SOCKBUF_UNLOCK(&cu->cu_socket->so_rcv);
 1018                 lastsocketref = FALSE;
 1019         }
 1020 
 1021         if (cu->cu_closeit && lastsocketref) {
 1022                 so = cu->cu_socket;
 1023                 cu->cu_socket = NULL;
 1024         }
 1025 
 1026         if (so)
 1027                 soclose(so);
 1028 
 1029         if (cl->cl_netid && cl->cl_netid[0])
 1030                 mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
 1031         if (cl->cl_tp && cl->cl_tp[0])
 1032                 mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
 1033         mem_free(cu, sizeof (*cu));
 1034         mem_free(cl, sizeof (CLIENT));
 1035 }
 1036 
 1037 /*
 1038  * Make sure that the time is not garbage.  -1 value is allowed.
 1039  */
 1040 static bool_t
 1041 time_not_ok(struct timeval *t)
 1042 {
 1043         return (t->tv_sec < -1 || t->tv_sec > 100000000 ||
 1044                 t->tv_usec < -1 || t->tv_usec > 1000000);
 1045 }
 1046 
 1047 int
 1048 clnt_dg_soupcall(struct socket *so, void *arg, int waitflag)
 1049 {
 1050         struct cu_socket *cs = (struct cu_socket *) arg;
 1051         struct uio uio;
 1052         struct mbuf *m;
 1053         struct mbuf *control;
 1054         struct cu_request *cr;
 1055         int error, rcvflag, foundreq;
 1056         uint32_t xid;
 1057 
 1058         cs->cs_upcallrefs++;
 1059         uio.uio_resid = 1000000000;
 1060         uio.uio_td = curthread;
 1061         do {
 1062                 SOCKBUF_UNLOCK(&so->so_rcv);
 1063                 m = NULL;
 1064                 control = NULL;
 1065                 rcvflag = MSG_DONTWAIT;
 1066                 error = soreceive(so, NULL, &uio, &m, &control, &rcvflag);
 1067                 if (control)
 1068                         m_freem(control);
 1069                 SOCKBUF_LOCK(&so->so_rcv);
 1070 
 1071                 if (error == EWOULDBLOCK)
 1072                         break;
 1073 
 1074                 /*
 1075                  * If there was an error, wake up all pending
 1076                  * requests.
 1077                  */
 1078                 if (error) {
 1079                         mtx_lock(&cs->cs_lock);
 1080                         TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
 1081                                 cr->cr_xid = 0;
 1082                                 cr->cr_error = error;
 1083                                 wakeup(cr);
 1084                         }
 1085                         mtx_unlock(&cs->cs_lock);
 1086                         break;
 1087                 }
 1088 
 1089                 /*
 1090                  * The XID is in the first uint32_t of the reply.
 1091                  */
 1092                 if (m->m_len < sizeof(xid) && m_length(m, NULL) < sizeof(xid)) {
 1093                         /*
 1094                          * Should never happen.
 1095                          */
 1096                         m_freem(m);
 1097                         continue;
 1098                 }
 1099 
 1100                 m_copydata(m, 0, sizeof(xid), (char *)&xid);
 1101                 xid = ntohl(xid);
 1102 
 1103                 /*
 1104                  * Attempt to match this reply with a pending request.
 1105                  */
 1106                 mtx_lock(&cs->cs_lock);
 1107                 foundreq = 0;
 1108                 TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
 1109                         if (cr->cr_xid == xid) {
 1110                                 /*
 1111                                  * This one matches. We leave the
 1112                                  * reply mbuf in cr->cr_mrep. Set the
 1113                                  * XID to zero so that we will ignore
 1114                                  * any duplicated replies that arrive
 1115                                  * before clnt_dg_call removes it from
 1116                                  * the queue.
 1117                                  */
 1118                                 cr->cr_xid = 0;
 1119                                 cr->cr_mrep = m;
 1120                                 cr->cr_error = 0;
 1121                                 foundreq = 1;
 1122                                 wakeup(cr);
 1123                                 break;
 1124                         }
 1125                 }
 1126                 mtx_unlock(&cs->cs_lock);
 1127 
 1128                 /*
 1129                  * If we didn't find the matching request, just drop
 1130                  * it - its probably a repeated reply.
 1131                  */
 1132                 if (!foundreq)
 1133                         m_freem(m);
 1134         } while (m);
 1135         cs->cs_upcallrefs--;
 1136         if (cs->cs_upcallrefs < 0)
 1137                 panic("rpcdg upcall refcnt");
 1138         if (cs->cs_upcallrefs == 0)
 1139                 wakeup(&cs->cs_upcallrefs);
 1140         return (SU_OK);
 1141 }
 1142 
 1143 /*
 1144  * Wait for all upcalls in progress to complete.
 1145  */
 1146 static void
 1147 clnt_dg_upcallsdone(struct socket *so, struct cu_socket *cs)
 1148 {
 1149 
 1150         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1151 
 1152         while (cs->cs_upcallrefs > 0)
 1153                 (void) msleep(&cs->cs_upcallrefs, SOCKBUF_MTX(&so->so_rcv), 0,
 1154                     "rpcdgup", 0);
 1155 }

Cache object: 76ca04c297d486c2e5b923c0aee54fbf


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