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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: clnt_dg.c,v 1.4 2000/07/14 08:40:41 fvdl Exp $ */
    2 
    3 /*-
    4  * Copyright (c) 2009, Sun Microsystems, Inc.
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without 
    8  * modification, are permitted provided that the following conditions are met:
    9  * - Redistributions of source code must retain the above copyright notice, 
   10  *   this list of conditions and the following disclaimer.
   11  * - Redistributions in binary form must reproduce the above copyright notice, 
   12  *   this list of conditions and the following disclaimer in the documentation 
   13  *   and/or other materials provided with the distribution.
   14  * - Neither the name of Sun Microsystems, Inc. nor the names of its 
   15  *   contributors may be used to endorse or promote products derived 
   16  *   from this software without specific prior written permission.
   17  * 
   18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
   19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
   20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
   21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
   22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
   23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
   24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
   25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
   26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
   27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
   28  * POSSIBILITY OF SUCH DAMAGE.
   29  */
   30 /*
   31  * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
   32  */
   33 
   34 #if defined(LIBC_SCCS) && !defined(lint)
   35 #ident  "@(#)clnt_dg.c  1.23    94/04/22 SMI"
   36 static char sccsid[] = "@(#)clnt_dg.c 1.19 89/03/16 Copyr 1988 Sun Micro";
   37 #endif
   38 #include <sys/cdefs.h>
   39 __FBSDID("$FreeBSD: releng/11.2/sys/rpc/clnt_dg.c 331722 2018-03-29 02:50:57Z eadler $");
   40 
   41 /*
   42  * Implements a connectionless client side RPC.
   43  */
   44 
   45 #include <sys/param.h>
   46 #include <sys/systm.h>
   47 #include <sys/kernel.h>
   48 #include <sys/lock.h>
   49 #include <sys/malloc.h>
   50 #include <sys/mbuf.h>
   51 #include <sys/mutex.h>
   52 #include <sys/pcpu.h>
   53 #include <sys/proc.h>
   54 #include <sys/socket.h>
   55 #include <sys/socketvar.h>
   56 #include <sys/time.h>
   57 #include <sys/uio.h>
   58 
   59 #include <net/vnet.h>
   60 
   61 #include <rpc/rpc.h>
   62 #include <rpc/rpc_com.h>
   63 
   64 
   65 #ifdef _FREEFALL_CONFIG
   66 /*
   67  * Disable RPC exponential back-off for FreeBSD.org systems.
   68  */
   69 #define RPC_MAX_BACKOFF         1 /* second */
   70 #else
   71 #define RPC_MAX_BACKOFF         30 /* seconds */
   72 #endif
   73 
   74 static bool_t time_not_ok(struct timeval *);
   75 static enum clnt_stat clnt_dg_call(CLIENT *, struct rpc_callextra *,
   76     rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
   77 static void clnt_dg_geterr(CLIENT *, struct rpc_err *);
   78 static bool_t clnt_dg_freeres(CLIENT *, xdrproc_t, void *);
   79 static void clnt_dg_abort(CLIENT *);
   80 static bool_t clnt_dg_control(CLIENT *, u_int, void *);
   81 static void clnt_dg_close(CLIENT *);
   82 static void clnt_dg_destroy(CLIENT *);
   83 static int clnt_dg_soupcall(struct socket *so, void *arg, int waitflag);
   84 
   85 static struct clnt_ops clnt_dg_ops = {
   86         .cl_call =      clnt_dg_call,
   87         .cl_abort =     clnt_dg_abort,
   88         .cl_geterr =    clnt_dg_geterr,
   89         .cl_freeres =   clnt_dg_freeres,
   90         .cl_close =     clnt_dg_close,
   91         .cl_destroy =   clnt_dg_destroy,
   92         .cl_control =   clnt_dg_control
   93 };
   94 
   95 /*
   96  * A pending RPC request which awaits a reply. Requests which have
   97  * received their reply will have cr_xid set to zero and cr_mrep to
   98  * the mbuf chain of the reply.
   99  */
  100 struct cu_request {
  101         TAILQ_ENTRY(cu_request) cr_link;
  102         CLIENT                  *cr_client;     /* owner */
  103         uint32_t                cr_xid;         /* XID of request */
  104         struct mbuf             *cr_mrep;       /* reply received by upcall */
  105         int                     cr_error;       /* any error from upcall */
  106         char                    cr_verf[MAX_AUTH_BYTES]; /* reply verf */
  107 };
  108 
  109 TAILQ_HEAD(cu_request_list, cu_request);
  110 
  111 #define MCALL_MSG_SIZE 24
  112 
  113 /*
  114  * This structure is pointed to by the socket buffer's sb_upcallarg
  115  * member. It is separate from the client private data to facilitate
  116  * multiple clients sharing the same socket. The cs_lock mutex is used
  117  * to protect all fields of this structure, the socket's receive
  118  * buffer SOCKBUF_LOCK is used to ensure that exactly one of these
  119  * structures is installed on the socket.
  120  */
  121 struct cu_socket {
  122         struct mtx              cs_lock;
  123         int                     cs_refs;        /* Count of clients */
  124         struct cu_request_list  cs_pending;     /* Requests awaiting replies */
  125         int                     cs_upcallrefs;  /* Refcnt of upcalls in prog.*/
  126 };
  127 
  128 static void clnt_dg_upcallsdone(struct socket *, struct cu_socket *);
  129 
  130 /*
  131  * Private data kept per client handle
  132  */
  133 struct cu_data {
  134         int                     cu_threads;     /* # threads in clnt_vc_call */
  135         bool_t                  cu_closing;     /* TRUE if we are closing */
  136         bool_t                  cu_closed;      /* TRUE if we are closed */
  137         struct socket           *cu_socket;     /* connection socket */
  138         bool_t                  cu_closeit;     /* opened by library */
  139         struct sockaddr_storage cu_raddr;       /* remote address */
  140         int                     cu_rlen;
  141         struct timeval          cu_wait;        /* retransmit interval */
  142         struct timeval          cu_total;       /* total time for the call */
  143         struct rpc_err          cu_error;
  144         uint32_t                cu_xid;
  145         char                    cu_mcallc[MCALL_MSG_SIZE]; /* marshalled callmsg */
  146         size_t                  cu_mcalllen;
  147         size_t                  cu_sendsz;      /* send size */
  148         size_t                  cu_recvsz;      /* recv size */
  149         int                     cu_async;
  150         int                     cu_connect;     /* Use connect(). */
  151         int                     cu_connected;   /* Have done connect(). */
  152         const char              *cu_waitchan;
  153         int                     cu_waitflag;
  154         int                     cu_cwnd;        /* congestion window */
  155         int                     cu_sent;        /* number of in-flight RPCs */
  156         bool_t                  cu_cwnd_wait;
  157 };
  158 
  159 #define CWNDSCALE       256
  160 #define MAXCWND         (32 * CWNDSCALE)
  161 
  162 /*
  163  * Connection less client creation returns with client handle parameters.
  164  * Default options are set, which the user can change using clnt_control().
  165  * fd should be open and bound.
  166  * NB: The rpch->cl_auth is initialized to null authentication.
  167  *      Caller may wish to set this something more useful.
  168  *
  169  * sendsz and recvsz are the maximum allowable packet sizes that can be
  170  * sent and received. Normally they are the same, but they can be
  171  * changed to improve the program efficiency and buffer allocation.
  172  * If they are 0, use the transport default.
  173  *
  174  * If svcaddr is NULL, returns NULL.
  175  */
  176 CLIENT *
  177 clnt_dg_create(
  178         struct socket *so,
  179         struct sockaddr *svcaddr,       /* servers address */
  180         rpcprog_t program,              /* program number */
  181         rpcvers_t version,              /* version number */
  182         size_t sendsz,                  /* buffer recv size */
  183         size_t recvsz)                  /* buffer send size */
  184 {
  185         CLIENT *cl = NULL;              /* client handle */
  186         struct cu_data *cu = NULL;      /* private data */
  187         struct cu_socket *cs = NULL;
  188         struct sockbuf *sb;
  189         struct timeval now;
  190         struct rpc_msg call_msg;
  191         struct __rpc_sockinfo si;
  192         XDR xdrs;
  193         int error;
  194 
  195         if (svcaddr == NULL) {
  196                 rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
  197                 return (NULL);
  198         }
  199 
  200         if (!__rpc_socket2sockinfo(so, &si)) {
  201                 rpc_createerr.cf_stat = RPC_TLIERROR;
  202                 rpc_createerr.cf_error.re_errno = 0;
  203                 return (NULL);
  204         }
  205 
  206         /*
  207          * Find the receive and the send size
  208          */
  209         sendsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsz);
  210         recvsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsz);
  211         if ((sendsz == 0) || (recvsz == 0)) {
  212                 rpc_createerr.cf_stat = RPC_TLIERROR; /* XXX */
  213                 rpc_createerr.cf_error.re_errno = 0;
  214                 return (NULL);
  215         }
  216 
  217         cl = mem_alloc(sizeof (CLIENT));
  218 
  219         /*
  220          * Should be multiple of 4 for XDR.
  221          */
  222         sendsz = rounddown(sendsz + 3, 4);
  223         recvsz = rounddown(recvsz + 3, 4);
  224         cu = mem_alloc(sizeof (*cu));
  225         cu->cu_threads = 0;
  226         cu->cu_closing = FALSE;
  227         cu->cu_closed = FALSE;
  228         (void) memcpy(&cu->cu_raddr, svcaddr, (size_t)svcaddr->sa_len);
  229         cu->cu_rlen = svcaddr->sa_len;
  230         /* Other values can also be set through clnt_control() */
  231         cu->cu_wait.tv_sec = 3; /* heuristically chosen */
  232         cu->cu_wait.tv_usec = 0;
  233         cu->cu_total.tv_sec = -1;
  234         cu->cu_total.tv_usec = -1;
  235         cu->cu_sendsz = sendsz;
  236         cu->cu_recvsz = recvsz;
  237         cu->cu_async = FALSE;
  238         cu->cu_connect = FALSE;
  239         cu->cu_connected = FALSE;
  240         cu->cu_waitchan = "rpcrecv";
  241         cu->cu_waitflag = 0;
  242         cu->cu_cwnd = MAXCWND / 2;
  243         cu->cu_sent = 0;
  244         cu->cu_cwnd_wait = FALSE;
  245         (void) getmicrotime(&now);
  246         cu->cu_xid = __RPC_GETXID(&now);
  247         call_msg.rm_xid = cu->cu_xid;
  248         call_msg.rm_call.cb_prog = program;
  249         call_msg.rm_call.cb_vers = version;
  250         xdrmem_create(&xdrs, cu->cu_mcallc, MCALL_MSG_SIZE, XDR_ENCODE);
  251         if (! xdr_callhdr(&xdrs, &call_msg)) {
  252                 rpc_createerr.cf_stat = RPC_CANTENCODEARGS;  /* XXX */
  253                 rpc_createerr.cf_error.re_errno = 0;
  254                 goto err2;
  255         }
  256         cu->cu_mcalllen = XDR_GETPOS(&xdrs);
  257 
  258         /*
  259          * By default, closeit is always FALSE. It is users responsibility
  260          * to do a close on it, else the user may use clnt_control
  261          * to let clnt_destroy do it for him/her.
  262          */
  263         cu->cu_closeit = FALSE;
  264         cu->cu_socket = so;
  265         error = soreserve(so, (u_long)sendsz, (u_long)recvsz);
  266         if (error != 0) {
  267                 rpc_createerr.cf_stat = RPC_FAILED;
  268                 rpc_createerr.cf_error.re_errno = error;
  269                 goto err2;
  270         }
  271 
  272         sb = &so->so_rcv;
  273         SOCKBUF_LOCK(&so->so_rcv);
  274 recheck_socket:
  275         if (sb->sb_upcall) {
  276                 if (sb->sb_upcall != clnt_dg_soupcall) {
  277                         SOCKBUF_UNLOCK(&so->so_rcv);
  278                         printf("clnt_dg_create(): socket already has an incompatible upcall\n");
  279                         goto err2;
  280                 }
  281                 cs = (struct cu_socket *) sb->sb_upcallarg;
  282                 mtx_lock(&cs->cs_lock);
  283                 cs->cs_refs++;
  284                 mtx_unlock(&cs->cs_lock);
  285         } else {
  286                 /*
  287                  * We are the first on this socket - allocate the
  288                  * structure and install it in the socket.
  289                  */
  290                 SOCKBUF_UNLOCK(&so->so_rcv);
  291                 cs = mem_alloc(sizeof(*cs));
  292                 SOCKBUF_LOCK(&so->so_rcv);
  293                 if (sb->sb_upcall) {
  294                         /*
  295                          * We have lost a race with some other client.
  296                          */
  297                         mem_free(cs, sizeof(*cs));
  298                         goto recheck_socket;
  299                 }
  300                 mtx_init(&cs->cs_lock, "cs->cs_lock", NULL, MTX_DEF);
  301                 cs->cs_refs = 1;
  302                 cs->cs_upcallrefs = 0;
  303                 TAILQ_INIT(&cs->cs_pending);
  304                 soupcall_set(so, SO_RCV, clnt_dg_soupcall, cs);
  305         }
  306         SOCKBUF_UNLOCK(&so->so_rcv);
  307 
  308         cl->cl_refs = 1;
  309         cl->cl_ops = &clnt_dg_ops;
  310         cl->cl_private = (caddr_t)(void *)cu;
  311         cl->cl_auth = authnone_create();
  312         cl->cl_tp = NULL;
  313         cl->cl_netid = NULL;
  314         return (cl);
  315 err2:
  316         mem_free(cl, sizeof (CLIENT));
  317         mem_free(cu, sizeof (*cu));
  318 
  319         return (NULL);
  320 }
  321 
  322 static enum clnt_stat
  323 clnt_dg_call(
  324         CLIENT          *cl,            /* client handle */
  325         struct rpc_callextra *ext,      /* call metadata */
  326         rpcproc_t       proc,           /* procedure number */
  327         struct mbuf     *args,          /* pointer to args */
  328         struct mbuf     **resultsp,     /* pointer to results */
  329         struct timeval  utimeout)       /* seconds to wait before giving up */
  330 {
  331         struct cu_data *cu = (struct cu_data *)cl->cl_private;
  332         struct cu_socket *cs;
  333         struct rpc_timers *rt;
  334         AUTH *auth;
  335         struct rpc_err *errp;
  336         enum clnt_stat stat;
  337         XDR xdrs;
  338         struct rpc_msg reply_msg;
  339         bool_t ok;
  340         int retrans;                    /* number of re-transmits so far */
  341         int nrefreshes = 2;             /* number of times to refresh cred */
  342         struct timeval *tvp;
  343         int timeout;
  344         int retransmit_time;
  345         int next_sendtime, starttime, rtt, time_waited, tv = 0;
  346         struct sockaddr *sa;
  347         socklen_t salen;
  348         uint32_t xid = 0;
  349         struct mbuf *mreq = NULL, *results;
  350         struct cu_request *cr;
  351         int error;
  352 
  353         cs = cu->cu_socket->so_rcv.sb_upcallarg;
  354         cr = malloc(sizeof(struct cu_request), M_RPC, M_WAITOK);
  355 
  356         mtx_lock(&cs->cs_lock);
  357 
  358         if (cu->cu_closing || cu->cu_closed) {
  359                 mtx_unlock(&cs->cs_lock);
  360                 free(cr, M_RPC);
  361                 return (RPC_CANTSEND);
  362         }
  363         cu->cu_threads++;
  364 
  365         if (ext) {
  366                 auth = ext->rc_auth;
  367                 errp = &ext->rc_err;
  368         } else {
  369                 auth = cl->cl_auth;
  370                 errp = &cu->cu_error;
  371         }
  372 
  373         cr->cr_client = cl;
  374         cr->cr_mrep = NULL;
  375         cr->cr_error = 0;
  376 
  377         if (cu->cu_total.tv_usec == -1) {
  378                 tvp = &utimeout; /* use supplied timeout */
  379         } else {
  380                 tvp = &cu->cu_total; /* use default timeout */
  381         }
  382         if (tvp->tv_sec || tvp->tv_usec)
  383                 timeout = tvtohz(tvp);
  384         else
  385                 timeout = 0;
  386 
  387         if (cu->cu_connect && !cu->cu_connected) {
  388                 mtx_unlock(&cs->cs_lock);
  389                 error = soconnect(cu->cu_socket,
  390                     (struct sockaddr *)&cu->cu_raddr, curthread);
  391                 mtx_lock(&cs->cs_lock);
  392                 if (error) {
  393                         errp->re_errno = error;
  394                         errp->re_status = stat = RPC_CANTSEND;
  395                         goto out;
  396                 }
  397                 cu->cu_connected = 1;
  398         }
  399         if (cu->cu_connected) {
  400                 sa = NULL;
  401                 salen = 0;
  402         } else {
  403                 sa = (struct sockaddr *)&cu->cu_raddr;
  404                 salen = cu->cu_rlen;
  405         }
  406         time_waited = 0;
  407         retrans = 0;
  408         if (ext && ext->rc_timers) {
  409                 rt = ext->rc_timers;
  410                 if (!rt->rt_rtxcur)
  411                         rt->rt_rtxcur = tvtohz(&cu->cu_wait);
  412                 retransmit_time = next_sendtime = rt->rt_rtxcur;
  413         } else {
  414                 rt = NULL;
  415                 retransmit_time = next_sendtime = tvtohz(&cu->cu_wait);
  416         }
  417 
  418         starttime = ticks;
  419 
  420 call_again:
  421         mtx_assert(&cs->cs_lock, MA_OWNED);
  422 
  423         cu->cu_xid++;
  424         xid = cu->cu_xid;
  425 
  426 send_again:
  427         mtx_unlock(&cs->cs_lock);
  428 
  429         mreq = m_gethdr(M_WAITOK, MT_DATA);
  430         KASSERT(cu->cu_mcalllen <= MHLEN, ("RPC header too big"));
  431         bcopy(cu->cu_mcallc, mreq->m_data, cu->cu_mcalllen);
  432         mreq->m_len = cu->cu_mcalllen;
  433 
  434         /*
  435          * The XID is the first thing in the request.
  436          */
  437         *mtod(mreq, uint32_t *) = htonl(xid);
  438 
  439         xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
  440 
  441         if (cu->cu_async == TRUE && args == NULL)
  442                 goto get_reply;
  443 
  444         if ((! XDR_PUTINT32(&xdrs, &proc)) ||
  445             (! AUTH_MARSHALL(auth, xid, &xdrs,
  446                 m_copym(args, 0, M_COPYALL, M_WAITOK)))) {
  447                 errp->re_status = stat = RPC_CANTENCODEARGS;
  448                 mtx_lock(&cs->cs_lock);
  449                 goto out;
  450         }
  451         mreq->m_pkthdr.len = m_length(mreq, NULL);
  452 
  453         cr->cr_xid = xid;
  454         mtx_lock(&cs->cs_lock);
  455 
  456         /*
  457          * Try to get a place in the congestion window.
  458          */
  459         while (cu->cu_sent >= cu->cu_cwnd) {
  460                 cu->cu_cwnd_wait = TRUE;
  461                 error = msleep(&cu->cu_cwnd_wait, &cs->cs_lock,
  462                     cu->cu_waitflag, "rpccwnd", 0);
  463                 if (error) {
  464                         errp->re_errno = error;
  465                         if (error == EINTR || error == ERESTART)
  466                                 errp->re_status = stat = RPC_INTR;
  467                         else
  468                                 errp->re_status = stat = RPC_CANTSEND;
  469                         goto out;
  470                 }
  471         }
  472         cu->cu_sent += CWNDSCALE;
  473 
  474         TAILQ_INSERT_TAIL(&cs->cs_pending, cr, cr_link);
  475         mtx_unlock(&cs->cs_lock);
  476 
  477         /*
  478          * sosend consumes mreq.
  479          */
  480         error = sosend(cu->cu_socket, sa, NULL, mreq, NULL, 0, curthread);
  481         mreq = NULL;
  482 
  483         /*
  484          * sub-optimal code appears here because we have
  485          * some clock time to spare while the packets are in flight.
  486          * (We assume that this is actually only executed once.)
  487          */
  488         reply_msg.acpted_rply.ar_verf.oa_flavor = AUTH_NULL;
  489         reply_msg.acpted_rply.ar_verf.oa_base = cr->cr_verf;
  490         reply_msg.acpted_rply.ar_verf.oa_length = 0;
  491         reply_msg.acpted_rply.ar_results.where = NULL;
  492         reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
  493 
  494         mtx_lock(&cs->cs_lock);
  495         if (error) {
  496                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
  497                 errp->re_errno = error;
  498                 errp->re_status = stat = RPC_CANTSEND;
  499                 cu->cu_sent -= CWNDSCALE;
  500                 if (cu->cu_cwnd_wait) {
  501                         cu->cu_cwnd_wait = FALSE;
  502                         wakeup(&cu->cu_cwnd_wait);
  503                 }
  504                 goto out;
  505         }
  506 
  507         /*
  508          * Check to see if we got an upcall while waiting for the
  509          * lock.
  510          */
  511         if (cr->cr_error) {
  512                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
  513                 errp->re_errno = cr->cr_error;
  514                 errp->re_status = stat = RPC_CANTRECV;
  515                 cu->cu_sent -= CWNDSCALE;
  516                 if (cu->cu_cwnd_wait) {
  517                         cu->cu_cwnd_wait = FALSE;
  518                         wakeup(&cu->cu_cwnd_wait);
  519                 }
  520                 goto out;
  521         }
  522         if (cr->cr_mrep) {
  523                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
  524                 cu->cu_sent -= CWNDSCALE;
  525                 if (cu->cu_cwnd_wait) {
  526                         cu->cu_cwnd_wait = FALSE;
  527                         wakeup(&cu->cu_cwnd_wait);
  528                 }
  529                 goto got_reply;
  530         }
  531 
  532         /*
  533          * Hack to provide rpc-based message passing
  534          */
  535         if (timeout == 0) {
  536                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
  537                 errp->re_status = stat = RPC_TIMEDOUT;
  538                 cu->cu_sent -= CWNDSCALE;
  539                 if (cu->cu_cwnd_wait) {
  540                         cu->cu_cwnd_wait = FALSE;
  541                         wakeup(&cu->cu_cwnd_wait);
  542                 }
  543                 goto out;
  544         }
  545 
  546 get_reply:
  547         for (;;) {
  548                 /* Decide how long to wait. */
  549                 if (next_sendtime < timeout)
  550                         tv = next_sendtime;
  551                 else
  552                         tv = timeout;
  553                 tv -= time_waited;
  554 
  555                 if (tv > 0) {
  556                         if (cu->cu_closing || cu->cu_closed) {
  557                                 error = 0;
  558                                 cr->cr_error = ESHUTDOWN;
  559                         } else {
  560                                 error = msleep(cr, &cs->cs_lock,
  561                                     cu->cu_waitflag, cu->cu_waitchan, tv);
  562                         }
  563                 } else {
  564                         error = EWOULDBLOCK;
  565                 }
  566 
  567                 TAILQ_REMOVE(&cs->cs_pending, cr, cr_link);
  568                 cu->cu_sent -= CWNDSCALE;
  569                 if (cu->cu_cwnd_wait) {
  570                         cu->cu_cwnd_wait = FALSE;
  571                         wakeup(&cu->cu_cwnd_wait);
  572                 }
  573 
  574                 if (!error) {
  575                         /*
  576                          * We were woken up by the upcall.  If the
  577                          * upcall had a receive error, report that,
  578                          * otherwise we have a reply.
  579                          */
  580                         if (cr->cr_error) {
  581                                 errp->re_errno = cr->cr_error;
  582                                 errp->re_status = stat = RPC_CANTRECV;
  583                                 goto out;
  584                         }
  585 
  586                         cu->cu_cwnd += (CWNDSCALE * CWNDSCALE
  587                             + cu->cu_cwnd / 2) / cu->cu_cwnd;
  588                         if (cu->cu_cwnd > MAXCWND)
  589                                 cu->cu_cwnd = MAXCWND;
  590 
  591                         if (rt) {
  592                                 /*
  593                                  * Add one to the time since a tick
  594                                  * count of N means that the actual
  595                                  * time taken was somewhere between N
  596                                  * and N+1.
  597                                  */
  598                                 rtt = ticks - starttime + 1;
  599 
  600                                 /*
  601                                  * Update our estimate of the round
  602                                  * trip time using roughly the
  603                                  * algorithm described in RFC
  604                                  * 2988. Given an RTT sample R:
  605                                  *
  606                                  * RTTVAR = (1-beta) * RTTVAR + beta * |SRTT-R|
  607                                  * SRTT = (1-alpha) * SRTT + alpha * R
  608                                  *
  609                                  * where alpha = 0.125 and beta = 0.25.
  610                                  *
  611                                  * The initial retransmit timeout is
  612                                  * SRTT + 4*RTTVAR and doubles on each
  613                                  * retransmision.
  614                                  */
  615                                 if (rt->rt_srtt == 0) {
  616                                         rt->rt_srtt = rtt;
  617                                         rt->rt_deviate = rtt / 2;
  618                                 } else {
  619                                         int32_t error = rtt - rt->rt_srtt;
  620                                         rt->rt_srtt += error / 8;
  621                                         error = abs(error) - rt->rt_deviate;
  622                                         rt->rt_deviate += error / 4;
  623                                 }
  624                                 rt->rt_rtxcur = rt->rt_srtt + 4*rt->rt_deviate;
  625                         }
  626 
  627                         break;
  628                 }
  629 
  630                 /*
  631                  * The sleep returned an error so our request is still
  632                  * on the list. If we got EWOULDBLOCK, we may want to
  633                  * re-send the request.
  634                  */
  635                 if (error != EWOULDBLOCK) {
  636                         errp->re_errno = error;
  637                         if (error == EINTR || error == ERESTART)
  638                                 errp->re_status = stat = RPC_INTR;
  639                         else
  640                                 errp->re_status = stat = RPC_CANTRECV;
  641                         goto out;
  642                 }
  643 
  644                 time_waited = ticks - starttime;
  645 
  646                 /* Check for timeout. */
  647                 if (time_waited > timeout) {
  648                         errp->re_errno = EWOULDBLOCK;
  649                         errp->re_status = stat = RPC_TIMEDOUT;
  650                         goto out;
  651                 }
  652 
  653                 /* Retransmit if necessary. */          
  654                 if (time_waited >= next_sendtime) {
  655                         cu->cu_cwnd /= 2;
  656                         if (cu->cu_cwnd < CWNDSCALE)
  657                                 cu->cu_cwnd = CWNDSCALE;
  658                         if (ext && ext->rc_feedback) {
  659                                 mtx_unlock(&cs->cs_lock);
  660                                 if (retrans == 0)
  661                                         ext->rc_feedback(FEEDBACK_REXMIT1,
  662                                             proc, ext->rc_feedback_arg);
  663                                 else
  664                                         ext->rc_feedback(FEEDBACK_REXMIT2,
  665                                             proc, ext->rc_feedback_arg);
  666                                 mtx_lock(&cs->cs_lock);
  667                         }
  668                         if (cu->cu_closing || cu->cu_closed) {
  669                                 errp->re_errno = ESHUTDOWN;
  670                                 errp->re_status = stat = RPC_CANTRECV;
  671                                 goto out;
  672                         }
  673                         retrans++;
  674                         /* update retransmit_time */
  675                         if (retransmit_time < RPC_MAX_BACKOFF * hz)
  676                                 retransmit_time = 2 * retransmit_time;
  677                         next_sendtime += retransmit_time;
  678                         goto send_again;
  679                 }
  680                 cu->cu_sent += CWNDSCALE;
  681                 TAILQ_INSERT_TAIL(&cs->cs_pending, cr, cr_link);
  682         }
  683 
  684 got_reply:
  685         /*
  686          * Now decode and validate the response. We need to drop the
  687          * lock since xdr_replymsg may end up sleeping in malloc.
  688          */
  689         mtx_unlock(&cs->cs_lock);
  690 
  691         if (ext && ext->rc_feedback)
  692                 ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
  693 
  694         xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
  695         ok = xdr_replymsg(&xdrs, &reply_msg);
  696         cr->cr_mrep = NULL;
  697 
  698         if (ok) {
  699                 if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
  700                     (reply_msg.acpted_rply.ar_stat == SUCCESS))
  701                         errp->re_status = stat = RPC_SUCCESS;
  702                 else
  703                         stat = _seterr_reply(&reply_msg, &(cu->cu_error));
  704 
  705                 if (errp->re_status == RPC_SUCCESS) {
  706                         results = xdrmbuf_getall(&xdrs);
  707                         if (! AUTH_VALIDATE(auth, xid,
  708                                 &reply_msg.acpted_rply.ar_verf,
  709                                 &results)) {
  710                                 errp->re_status = stat = RPC_AUTHERROR;
  711                                 errp->re_why = AUTH_INVALIDRESP;
  712                                 if (retrans &&
  713                                     auth->ah_cred.oa_flavor == RPCSEC_GSS) {
  714                                         /*
  715                                          * If we retransmitted, its
  716                                          * possible that we will
  717                                          * receive a reply for one of
  718                                          * the earlier transmissions
  719                                          * (which will use an older
  720                                          * RPCSEC_GSS sequence
  721                                          * number). In this case, just
  722                                          * go back and listen for a
  723                                          * new reply. We could keep a
  724                                          * record of all the seq
  725                                          * numbers we have transmitted
  726                                          * so far so that we could
  727                                          * accept a reply for any of
  728                                          * them here.
  729                                          */
  730                                         XDR_DESTROY(&xdrs);
  731                                         mtx_lock(&cs->cs_lock);
  732                                         cu->cu_sent += CWNDSCALE;
  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 unsuccessful 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                  * beginning 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                  * beginning 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         SOCKBUF_LOCK(&cu->cu_socket->so_rcv);
 1002         mtx_lock(&cs->cs_lock);
 1003 
 1004         cs->cs_refs--;
 1005         if (cs->cs_refs == 0) {
 1006                 mtx_unlock(&cs->cs_lock);
 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                 SOCKBUF_UNLOCK(&cu->cu_socket->so_rcv);
 1016                 lastsocketref = FALSE;
 1017         }
 1018 
 1019         if (cu->cu_closeit && lastsocketref) {
 1020                 so = cu->cu_socket;
 1021                 cu->cu_socket = NULL;
 1022         }
 1023 
 1024         if (so)
 1025                 soclose(so);
 1026 
 1027         if (cl->cl_netid && cl->cl_netid[0])
 1028                 mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
 1029         if (cl->cl_tp && cl->cl_tp[0])
 1030                 mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
 1031         mem_free(cu, sizeof (*cu));
 1032         mem_free(cl, sizeof (CLIENT));
 1033 }
 1034 
 1035 /*
 1036  * Make sure that the time is not garbage.  -1 value is allowed.
 1037  */
 1038 static bool_t
 1039 time_not_ok(struct timeval *t)
 1040 {
 1041         return (t->tv_sec < -1 || t->tv_sec > 100000000 ||
 1042                 t->tv_usec < -1 || t->tv_usec > 1000000);
 1043 }
 1044 
 1045 int
 1046 clnt_dg_soupcall(struct socket *so, void *arg, int waitflag)
 1047 {
 1048         struct cu_socket *cs = (struct cu_socket *) arg;
 1049         struct uio uio;
 1050         struct mbuf *m;
 1051         struct mbuf *control;
 1052         struct cu_request *cr;
 1053         int error, rcvflag, foundreq;
 1054         uint32_t xid;
 1055 
 1056         cs->cs_upcallrefs++;
 1057         uio.uio_resid = 1000000000;
 1058         uio.uio_td = curthread;
 1059         do {
 1060                 SOCKBUF_UNLOCK(&so->so_rcv);
 1061                 m = NULL;
 1062                 control = NULL;
 1063                 rcvflag = MSG_DONTWAIT;
 1064                 error = soreceive(so, NULL, &uio, &m, &control, &rcvflag);
 1065                 if (control)
 1066                         m_freem(control);
 1067                 SOCKBUF_LOCK(&so->so_rcv);
 1068 
 1069                 if (error == EWOULDBLOCK)
 1070                         break;
 1071 
 1072                 /*
 1073                  * If there was an error, wake up all pending
 1074                  * requests.
 1075                  */
 1076                 if (error) {
 1077                         mtx_lock(&cs->cs_lock);
 1078                         TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
 1079                                 cr->cr_xid = 0;
 1080                                 cr->cr_error = error;
 1081                                 wakeup(cr);
 1082                         }
 1083                         mtx_unlock(&cs->cs_lock);
 1084                         break;
 1085                 }
 1086 
 1087                 /*
 1088                  * The XID is in the first uint32_t of the reply.
 1089                  */
 1090                 if (m->m_len < sizeof(xid) && m_length(m, NULL) < sizeof(xid)) {
 1091                         /*
 1092                          * Should never happen.
 1093                          */
 1094                         m_freem(m);
 1095                         continue;
 1096                 }
 1097 
 1098                 m_copydata(m, 0, sizeof(xid), (char *)&xid);
 1099                 xid = ntohl(xid);
 1100 
 1101                 /*
 1102                  * Attempt to match this reply with a pending request.
 1103                  */
 1104                 mtx_lock(&cs->cs_lock);
 1105                 foundreq = 0;
 1106                 TAILQ_FOREACH(cr, &cs->cs_pending, cr_link) {
 1107                         if (cr->cr_xid == xid) {
 1108                                 /*
 1109                                  * This one matches. We leave the
 1110                                  * reply mbuf in cr->cr_mrep. Set the
 1111                                  * XID to zero so that we will ignore
 1112                                  * any duplicated replies that arrive
 1113                                  * before clnt_dg_call removes it from
 1114                                  * the queue.
 1115                                  */
 1116                                 cr->cr_xid = 0;
 1117                                 cr->cr_mrep = m;
 1118                                 cr->cr_error = 0;
 1119                                 foundreq = 1;
 1120                                 wakeup(cr);
 1121                                 break;
 1122                         }
 1123                 }
 1124                 mtx_unlock(&cs->cs_lock);
 1125 
 1126                 /*
 1127                  * If we didn't find the matching request, just drop
 1128                  * it - its probably a repeated reply.
 1129                  */
 1130                 if (!foundreq)
 1131                         m_freem(m);
 1132         } while (m);
 1133         cs->cs_upcallrefs--;
 1134         if (cs->cs_upcallrefs < 0)
 1135                 panic("rpcdg upcall refcnt");
 1136         if (cs->cs_upcallrefs == 0)
 1137                 wakeup(&cs->cs_upcallrefs);
 1138         return (SU_OK);
 1139 }
 1140 
 1141 /*
 1142  * Wait for all upcalls in progress to complete.
 1143  */
 1144 static void
 1145 clnt_dg_upcallsdone(struct socket *so, struct cu_socket *cs)
 1146 {
 1147 
 1148         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1149 
 1150         while (cs->cs_upcallrefs > 0)
 1151                 (void) msleep(&cs->cs_upcallrefs, SOCKBUF_MTX(&so->so_rcv), 0,
 1152                     "rpcdgup", 0);
 1153 }

Cache object: b2dd248e3833cc64db83da7362731781


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.