/*      $NetBSD: clnt_dg.c,v 1.33 2024/01/23 17:24:38 christos Exp $    */

/*
* Copyright (c) 2010, Oracle America, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
*     * Redistributions of source code must retain the above copyright
*       notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above
*       copyright notice, this list of conditions and the following
*       disclaimer in the documentation and/or other materials
*       provided with the distribution.
*     * Neither the name of the "Oracle America, Inc." nor the names of its
*       contributors may be used to endorse or promote products derived
*       from this software without specific prior written permission.
*
*   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
*   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
*   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
*   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
*   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
*   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
*   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
*   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
*   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
*   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
*   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1986-1991 by Sun Microsystems Inc.
*/

/* #ident       "@(#)clnt_dg.c  1.23    94/04/22 SMI" */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)clnt_dg.c 1.19 89/03/16 Copyr 1988 Sun Micro";
#else
__RCSID("$NetBSD: clnt_dg.c,v 1.33 2024/01/23 17:24:38 christos Exp $");
#endif
#endif

/*
* Implements a connectionless client side RPC.
*/

#include "namespace.h"
#include "reentrant.h"
#include <sys/poll.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <rpc/rpc.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <err.h>

#include "svc_fdset.h"
#include "rpc_internal.h"

#ifdef __weak_alias
__weak_alias(clnt_dg_create,_clnt_dg_create)
#endif

#define RPC_MAX_BACKOFF         30 /* seconds */


static struct clnt_ops *clnt_dg_ops(void);
static bool_t time_not_ok(struct timeval *);
static enum clnt_stat clnt_dg_call(CLIENT *, rpcproc_t, xdrproc_t,
   const char *, xdrproc_t, caddr_t, struct timeval);
static void clnt_dg_geterr(CLIENT *, struct rpc_err *);
static bool_t clnt_dg_freeres(CLIENT *, xdrproc_t, caddr_t);
static void clnt_dg_abort(CLIENT *);
static bool_t clnt_dg_control(CLIENT *, u_int, char *);
static void clnt_dg_destroy(CLIENT *);




/*
*      This machinery implements per-fd locks for MT-safety.  It is not
*      sufficient to do per-CLIENT handle locks for MT-safety because a
*      user may create more than one CLIENT handle with the same fd behind
*      it.  Therefore, we allocate an array of flags (dg_fd_locks), protected
*      by the clnt_fd_lock mutex, and an array (dg_cv) of condition variables
*      similarly protected.  Dg_fd_lock[fd] == 1 => a call is active on some
*      CLIENT handle created for that fd.
*      The current implementation holds locks across the entire RPC and reply,
*      including retransmissions.  Yes, this is silly, and as soon as this
*      code is proven to work, this should be the first thing fixed.  One step
*      at a time.
*/
static int      *dg_fd_locks;
#ifdef _REENTRANT
#define __rpc_lock_value __isthreaded;
static cond_t   *dg_cv;
#define release_fd_lock(fd, mask) {             \
       mutex_lock(&clnt_fd_lock);      \
       dg_fd_locks[fd] = 0;            \
       mutex_unlock(&clnt_fd_lock);    \
       thr_sigsetmask(SIG_SETMASK, &(mask), NULL);     \
       cond_signal(&dg_cv[fd]);        \
}
#else
#define release_fd_lock(fd,mask)
#define __rpc_lock_value 0
#endif

static const char mem_err_clnt_dg[] = "clnt_dg_create: out of memory";

/* VARIABLES PROTECTED BY clnt_fd_lock: dg_fd_locks, dg_cv */

/*
* Private data kept per client handle
*/
struct cu_data {
       int                     cu_fd;          /* connections fd */
       bool_t                  cu_closeit;     /* opened by library */
       struct sockaddr_storage cu_raddr;       /* remote address */
       int                     cu_rlen;
       struct timeval          cu_wait;        /* retransmit interval */
       struct timeval          cu_total;       /* total time for the call */
       struct rpc_err          cu_error;
       XDR                     cu_outxdrs;
       u_int                   cu_xdrpos;
       u_int                   cu_sendsz;      /* send size */
       char                    *cu_outbuf;
       u_int                   cu_recvsz;      /* recv size */
       struct pollfd           cu_pfdp;
       char                    cu_inbuf[1];
};

/*
* Connection less client creation returns with client handle parameters.
* Default options are set, which the user can change using clnt_control().
* fd should be open and bound.
* NB: The rpch->cl_auth is initialized to null authentication.
*      Caller may wish to set this something more useful.
*
* sendsz and recvsz are the maximum allowable packet sizes that can be
* sent and received. Normally they are the same, but they can be
* changed to improve the program efficiency and buffer allocation.
* If they are 0, use the transport default.
*
* If svcaddr is NULL, returns NULL.
*/
CLIENT *
clnt_dg_create(
       int fd,                         /* open file descriptor */
       const struct netbuf *svcaddr,   /* servers address */
       rpcprog_t program,              /* program number */
       rpcvers_t version,              /* version number */
       u_int sendsz,                   /* buffer recv size */
       u_int recvsz)                   /* buffer send size */
{
       CLIENT *cl = NULL;              /* client handle */
       struct cu_data *cu = NULL;      /* private data */
       struct rpc_msg call_msg;
#ifdef _REENTRANT
       sigset_t mask;
#endif
       sigset_t newmask;
       struct __rpc_sockinfo si;
       int one = 1;

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&clnt_fd_lock);
       if (dg_fd_locks == NULL) {
#ifdef _REENTRANT
               size_t cv_allocsz;
#endif
               size_t fd_allocsz;
               int dtbsize = __rpc_dtbsize();

               fd_allocsz = dtbsize * sizeof (int);
               dg_fd_locks = mem_alloc(fd_allocsz);
               if (dg_fd_locks == NULL) {
                       goto err0;
               } else
                       memset(dg_fd_locks, '\0', fd_allocsz);

#ifdef _REENTRANT
               cv_allocsz = dtbsize * sizeof (cond_t);
               dg_cv = mem_alloc(cv_allocsz);
               if (dg_cv == NULL) {
                       mem_free(dg_fd_locks, fd_allocsz);
                       dg_fd_locks = NULL;
                       goto err0;
               } else {
                       int i;

                       for (i = 0; i < dtbsize; i++)
                               cond_init(&dg_cv[i], 0, (void *) 0);
               }
#endif
       }

       mutex_unlock(&clnt_fd_lock);
       thr_sigsetmask(SIG_SETMASK, &(mask), NULL);

       if (svcaddr == NULL) {
               rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
               return (NULL);
       }

       if (!__rpc_fd2sockinfo(fd, &si)) {
               rpc_createerr.cf_stat = RPC_TLIERROR;
               rpc_createerr.cf_error.re_errno = 0;
               return (NULL);
       }
       /*
        * Find the receive and the send size
        */
       sendsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsz);
       recvsz = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsz);
       if ((sendsz == 0) || (recvsz == 0)) {
               rpc_createerr.cf_stat = RPC_TLIERROR; /* XXX */
               rpc_createerr.cf_error.re_errno = 0;
               return (NULL);
       }

       if ((cl = mem_alloc(sizeof (CLIENT))) == NULL)
               goto err1;
       /*
        * Should be multiple of 4 for XDR.
        */
       sendsz = ((sendsz + 3) / 4) * 4;
       recvsz = ((recvsz + 3) / 4) * 4;
       cu = malloc(sizeof (*cu) + sendsz + recvsz);
       if (cu == NULL)
               goto err1;
       memset(cu, 0, sizeof(*cu));
       (void) memcpy(&cu->cu_raddr, svcaddr->buf, (size_t)svcaddr->len);
       cu->cu_rlen = svcaddr->len;
       cu->cu_outbuf = &cu->cu_inbuf[recvsz];
       /* Other values can also be set through clnt_control() */
#ifdef RUMP_RPC
       cu->cu_wait.tv_sec = 15;        /* heuristically chosen */
       cu->cu_wait.tv_usec = 0;
#else
       cu->cu_wait.tv_sec = 0;         /* for testing, 10x / second */
       cu->cu_wait.tv_usec = 100000;
#endif
       cu->cu_total.tv_sec = -1;
       cu->cu_total.tv_usec = -1;
       cu->cu_sendsz = sendsz;
       cu->cu_recvsz = recvsz;
       call_msg.rm_xid = __RPC_GETXID();
       call_msg.rm_call.cb_prog = program;
       call_msg.rm_call.cb_vers = version;
       xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf, sendsz, XDR_ENCODE);
       if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
               rpc_createerr.cf_stat = RPC_CANTENCODEARGS;  /* XXX */
               rpc_createerr.cf_error.re_errno = 0;
               goto err2;
       }
       cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));

       /* XXX fvdl - do we still want this? */
#if 0
       (void)bindresvport_sa(fd, (struct sockaddr *)svcaddr->buf);
#endif
       ioctl(fd, FIONBIO, (char *)(void *)&one);

       /*
        * By default, closeit is always FALSE. It is users responsibility
        * to do a close on it, else the user may use clnt_control
        * to let clnt_destroy do it for him/her.
        */
       cu->cu_closeit = FALSE;
       cu->cu_fd = fd;
       cu->cu_pfdp.fd = cu->cu_fd;
       cu->cu_pfdp.events = POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND;
       cl->cl_ops = clnt_dg_ops();
       cl->cl_private = (caddr_t)(void *)cu;
       cl->cl_auth = authnone_create();
       cl->cl_tp = NULL;
       cl->cl_netid = NULL;
       return (cl);
err0:
       mutex_unlock(&clnt_fd_lock);
       thr_sigsetmask(SIG_SETMASK, &(mask), NULL);
err1:
       warnx(mem_err_clnt_dg);
       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
       rpc_createerr.cf_error.re_errno = errno;
err2:
       if (cl) {
               mem_free(cl, sizeof (CLIENT));
               if (cu)
                       mem_free(cu, sizeof (*cu) + sendsz + recvsz);
       }
       return (NULL);
}

static enum clnt_stat
clnt_dg_call(
       CLIENT *        cl,             /* client handle */
       rpcproc_t       proc,           /* procedure number */
       xdrproc_t       xargs,          /* xdr routine for args */
       const char *    argsp,          /* pointer to args */
       xdrproc_t       xresults,       /* xdr routine for results */
       caddr_t         resultsp,       /* pointer to results */
       struct timeval  utimeout)       /* seconds to wait before giving up */
{
       struct cu_data *cu;
       XDR *xdrs;
       size_t outlen;
       struct rpc_msg reply_msg;
       XDR reply_xdrs;
       bool_t ok;
       int nrefreshes = 2;             /* number of times to refresh cred */
       struct timeval timeout;
       struct timeval retransmit_time;
       struct timeval next_sendtime, starttime, time_waited, tv;
#ifdef _REENTRANT
       sigset_t mask, *maskp = &mask;
#else
       sigset_t *maskp = NULL;
#endif
       sigset_t newmask;
       ssize_t recvlen = 0;
       struct timespec ts;
       int n;

       _DIAGASSERT(cl != NULL);

       cu = (struct cu_data *)cl->cl_private;

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&clnt_fd_lock);
       while (dg_fd_locks[cu->cu_fd])
               cond_wait(&dg_cv[cu->cu_fd], &clnt_fd_lock);
       dg_fd_locks[cu->cu_fd] = __rpc_lock_value;
       mutex_unlock(&clnt_fd_lock);
       if (cu->cu_total.tv_usec == -1) {
               timeout = utimeout;     /* use supplied timeout */
       } else {
               timeout = cu->cu_total; /* use default timeout */
       }

       time_waited.tv_sec = 0;
       time_waited.tv_usec = 0;
       retransmit_time = next_sendtime = cu->cu_wait;
       gettimeofday(&starttime, NULL);

call_again:
       xdrs = &(cu->cu_outxdrs);
       xdrs->x_op = XDR_ENCODE;
       XDR_SETPOS(xdrs, cu->cu_xdrpos);
       /*
        * the transaction is the first thing in the out buffer
        */
       (*(u_int32_t *)(void *)(cu->cu_outbuf))++;
       if ((! XDR_PUTINT32(xdrs, (int32_t *)&proc)) ||
           (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
           (! (*xargs)(xdrs, __UNCONST(argsp)))) {
               cu->cu_error.re_status = RPC_CANTENCODEARGS;
               goto out;
       }
       outlen = (size_t)XDR_GETPOS(xdrs);

send_again:
       if ((size_t)sendto(cu->cu_fd, cu->cu_outbuf, outlen, 0,
           (struct sockaddr *)(void *)&cu->cu_raddr, (socklen_t)cu->cu_rlen)
           != outlen) {
               cu->cu_error.re_errno = errno;
               cu->cu_error.re_status = RPC_CANTSEND;
               goto out;
       }

       /*
        * Hack to provide rpc-based message passing
        */
       if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
               cu->cu_error.re_status = RPC_TIMEDOUT;
               goto out;
       }
       /*
        * sub-optimal code appears here because we have
        * some clock time to spare while the packets are in flight.
        * (We assume that this is actually only executed once.)
        */
       reply_msg.acpted_rply.ar_verf = _null_auth;
       reply_msg.acpted_rply.ar_results.where = resultsp;
       reply_msg.acpted_rply.ar_results.proc = xresults;


       for (;;) {
               /* Decide how long to wait. */
               if (timercmp(&next_sendtime, &timeout, <))
                       timersub(&next_sendtime, &time_waited, &tv);
               else
                       timersub(&timeout, &time_waited, &tv);
               if (tv.tv_sec < 0 || tv.tv_usec < 0)
                       tv.tv_sec = tv.tv_usec = 0;
               TIMEVAL_TO_TIMESPEC(&tv, &ts);

               n = pollts(&cu->cu_pfdp, 1, &ts, maskp);
               if (n == 1) {
                       /* We have some data now */
                       do {
                               recvlen = recvfrom(cu->cu_fd, cu->cu_inbuf,
                                   cu->cu_recvsz, 0, NULL, NULL);
                       } while (recvlen < 0 && errno == EINTR);

                       if (recvlen < 0 && errno != EWOULDBLOCK) {
                               cu->cu_error.re_errno = errno;
                               cu->cu_error.re_status = RPC_CANTRECV;
                               goto out;
                       }
                       if (recvlen >= (ssize_t)sizeof(uint32_t)) {
                               if (memcmp(cu->cu_inbuf, cu->cu_outbuf,
                                   sizeof(uint32_t)) == 0)
                                       /* Assume we have the proper reply. */
                                       break;
                       }
               }
               if (n == -1) {
                       cu->cu_error.re_errno = errno;
                       cu->cu_error.re_status = RPC_CANTRECV;
                       goto out;
               }

               gettimeofday(&tv, NULL);
               timersub(&tv, &starttime, &time_waited);

               /* Check for timeout. */
               if (timercmp(&time_waited, &timeout, >)) {
                       cu->cu_error.re_status = RPC_TIMEDOUT;
                       goto out;
               }

               /* Retransmit if necessary. */
               if (timercmp(&time_waited, &next_sendtime, >)) {
                       /* update retransmit_time */
                       if (retransmit_time.tv_sec < RPC_MAX_BACKOFF)
                               timeradd(&retransmit_time, &retransmit_time,
                                   &retransmit_time);
                       timeradd(&next_sendtime, &retransmit_time,
                           &next_sendtime);
                       goto send_again;
               }
       }

       /*
        * now decode and validate the response
        */

       xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)recvlen, XDR_DECODE);
       ok = xdr_replymsg(&reply_xdrs, &reply_msg);
       /* XDR_DESTROY(&reply_xdrs);    save a few cycles on noop destroy */
       if (ok) {
               if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
                       (reply_msg.acpted_rply.ar_stat == SUCCESS))
                       cu->cu_error.re_status = RPC_SUCCESS;
               else
                       _seterr_reply(&reply_msg, &(cu->cu_error));

               if (cu->cu_error.re_status == RPC_SUCCESS) {
                       if (! AUTH_VALIDATE(cl->cl_auth,
                                           &reply_msg.acpted_rply.ar_verf)) {
                               cu->cu_error.re_status = RPC_AUTHERROR;
                               cu->cu_error.re_why = AUTH_INVALIDRESP;
                       }
                       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
                               xdrs->x_op = XDR_FREE;
                               (void) xdr_opaque_auth(xdrs,
                                       &(reply_msg.acpted_rply.ar_verf));
                       }
               }               /* end successful completion */
               /*
                * If unsuccessful AND error is an authentication error
                * then refresh credentials and try again, else break
                */
               else if (cu->cu_error.re_status == RPC_AUTHERROR)
                       /* maybe our credentials need to be refreshed ... */
                       if (nrefreshes > 0 && AUTH_REFRESH(cl->cl_auth)) {
                               nrefreshes--;
                               goto call_again;
                       }
               /* end of unsuccessful completion */
       }       /* end of valid reply message */
       else {
               cu->cu_error.re_status = RPC_CANTDECODERES;

       }
out:
       release_fd_lock(cu->cu_fd, mask);
       return (cu->cu_error.re_status);
}

static void
clnt_dg_geterr(CLIENT *cl, struct rpc_err *errp)
{
       struct cu_data *cu;

       _DIAGASSERT(cl != NULL);
       _DIAGASSERT(errp != NULL);

       cu = (struct cu_data *)cl->cl_private;
       *errp = cu->cu_error;
}

static bool_t
clnt_dg_freeres(CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
{
       struct cu_data *cu;
       XDR *xdrs;
       bool_t dummy;
#ifdef _REENTRANT
       sigset_t mask;
#endif
       sigset_t newmask;

       _DIAGASSERT(cl != NULL);
       cu = (struct cu_data *)cl->cl_private;
       xdrs = &(cu->cu_outxdrs);

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&clnt_fd_lock);
       while (dg_fd_locks[cu->cu_fd])
               cond_wait(&dg_cv[cu->cu_fd], &clnt_fd_lock);
       xdrs->x_op = XDR_FREE;
       dummy = (*xdr_res)(xdrs, res_ptr);
       mutex_unlock(&clnt_fd_lock);
       thr_sigsetmask(SIG_SETMASK, &mask, NULL);
       cond_signal(&dg_cv[cu->cu_fd]);
       return (dummy);
}

/*ARGSUSED*/
static void
clnt_dg_abort(CLIENT *h)
{
}

static bool_t
clnt_dg_control(CLIENT *cl, u_int request, char *info)
{
       struct cu_data *cu;
       struct netbuf *addr;
#ifdef _REENTRANT
       sigset_t mask;
#endif
       sigset_t newmask;

       _DIAGASSERT(cl != NULL);
       /* info is handled below */

       cu = (struct cu_data *)cl->cl_private;

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&clnt_fd_lock);
       while (dg_fd_locks[cu->cu_fd])
               cond_wait(&dg_cv[cu->cu_fd], &clnt_fd_lock);
       dg_fd_locks[cu->cu_fd] = __rpc_lock_value;
       mutex_unlock(&clnt_fd_lock);
       switch (request) {
       case CLSET_FD_CLOSE:
               cu->cu_closeit = TRUE;
               release_fd_lock(cu->cu_fd, mask);
               return (TRUE);
       case CLSET_FD_NCLOSE:
               cu->cu_closeit = FALSE;
               release_fd_lock(cu->cu_fd, mask);
               return (TRUE);
       }

       /* for other requests which use info */
       if (info == NULL) {
               release_fd_lock(cu->cu_fd, mask);
               return (FALSE);
       }
       switch (request) {
       case CLSET_TIMEOUT:
               if (time_not_ok((struct timeval *)(void *)info)) {
                       release_fd_lock(cu->cu_fd, mask);
                       return (FALSE);
               }
               cu->cu_total = *(struct timeval *)(void *)info;
               break;
       case CLGET_TIMEOUT:
               *(struct timeval *)(void *)info = cu->cu_total;
               break;
       case CLGET_SERVER_ADDR:         /* Give him the fd address */
               /* Now obsolete. Only for backward compatibility */
               (void) memcpy(info, &cu->cu_raddr, (size_t)cu->cu_rlen);
               break;
       case CLSET_RETRY_TIMEOUT:
               if (time_not_ok((struct timeval *)(void *)info)) {
                       release_fd_lock(cu->cu_fd, mask);
                       return (FALSE);
               }
               cu->cu_wait = *(struct timeval *)(void *)info;
               break;
       case CLGET_RETRY_TIMEOUT:
               *(struct timeval *)(void *)info = cu->cu_wait;
               break;
       case CLGET_FD:
               *(int *)(void *)info = cu->cu_fd;
               break;
       case CLGET_SVC_ADDR:
               addr = (struct netbuf *)(void *)info;
               addr->buf = &cu->cu_raddr;
               addr->len = cu->cu_rlen;
               addr->maxlen = sizeof cu->cu_raddr;
               break;
       case CLSET_SVC_ADDR:            /* set to new address */
               addr = (struct netbuf *)(void *)info;
               if (addr->len < sizeof cu->cu_raddr) {
                       release_fd_lock(cu->cu_fd, mask);
                       return (FALSE);
               }
               (void) memcpy(&cu->cu_raddr, addr->buf, (size_t)addr->len);
               cu->cu_rlen = addr->len;
               break;
       case CLGET_XID:
               /*
                * use the knowledge that xid is the
                * first element in the call structure *.
                * This will get the xid of the PREVIOUS call
                */
               *(u_int32_t *)(void *)info =
                   ntohl(*(u_int32_t *)(void *)cu->cu_outbuf);
               break;

       case CLSET_XID:
               /* This will set the xid of the NEXT call */
               *(u_int32_t *)(void *)cu->cu_outbuf =
                   htonl(*(u_int32_t *)(void *)info - 1);
               /* decrement by 1 as clnt_dg_call() increments once */
               break;

       case CLGET_VERS:
               /*
                * This RELIES on the information that, in the call body,
                * the version number field is the fifth field from the
                * beginning of the RPC header. MUST be changed if the
                * call_struct is changed
                */
               *(u_int32_t *)(void *)info =
                   ntohl(*(u_int32_t *)(void *)(cu->cu_outbuf +
                   4 * BYTES_PER_XDR_UNIT));
               break;

       case CLSET_VERS:
               *(u_int32_t *)(void *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
                       = htonl(*(u_int32_t *)(void *)info);
               break;

       case CLGET_PROG:
               /*
                * This RELIES on the information that, in the call body,
                * the program number field is the fourth field from the
                * beginning of the RPC header. MUST be changed if the
                * call_struct is changed
                */
               *(u_int32_t *)(void *)info =
                   ntohl(*(u_int32_t *)(void *)(cu->cu_outbuf +
                   3 * BYTES_PER_XDR_UNIT));
               break;

       case CLSET_PROG:
               *(u_int32_t *)(void *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
                       = htonl(*(u_int32_t *)(void *)info);
               break;

       default:
               release_fd_lock(cu->cu_fd, mask);
               return (FALSE);
       }
       release_fd_lock(cu->cu_fd, mask);
       return (TRUE);
}

static void
clnt_dg_destroy(CLIENT *cl)
{
       struct cu_data *cu;
       int cu_fd;
#ifdef _REENTRANT
       sigset_t mask;
#endif
       sigset_t newmask;

       _DIAGASSERT(cl != NULL);

       cu = (struct cu_data *)cl->cl_private;
       cu_fd = cu->cu_fd;

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&clnt_fd_lock);
       while (dg_fd_locks[cu_fd])
               cond_wait(&dg_cv[cu_fd], &clnt_fd_lock);
       if (cu->cu_closeit)
               (void) close(cu_fd);
       XDR_DESTROY(&(cu->cu_outxdrs));
       mem_free(cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
       if (cl->cl_netid && cl->cl_netid[0])
               mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
       if (cl->cl_tp && cl->cl_tp[0])
               mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
       mem_free(cl, sizeof (CLIENT));
       mutex_unlock(&clnt_fd_lock);
       thr_sigsetmask(SIG_SETMASK, &mask, NULL);
       cond_signal(&dg_cv[cu_fd]);
}

static struct clnt_ops *
clnt_dg_ops(void)
{
       static struct clnt_ops ops;
#ifdef _REENTRANT
       sigset_t mask;
#endif
       sigset_t newmask;

/* VARIABLES PROTECTED BY ops_lock: ops */

       __clnt_sigfillset(&newmask);
       thr_sigsetmask(SIG_SETMASK, &newmask, &mask);
       mutex_lock(&ops_lock);
       if (ops.cl_call == NULL) {
               ops.cl_call = clnt_dg_call;
               ops.cl_abort = clnt_dg_abort;
               ops.cl_geterr = clnt_dg_geterr;
               ops.cl_freeres = clnt_dg_freeres;
               ops.cl_destroy = clnt_dg_destroy;
               ops.cl_control = clnt_dg_control;
       }
       mutex_unlock(&ops_lock);
       thr_sigsetmask(SIG_SETMASK, &mask, NULL);
       return (&ops);
}

/*
* Make sure that the time is not garbage.  -1 value is allowed.
*/
static bool_t
time_not_ok(struct timeval *t)
{

       _DIAGASSERT(t != NULL);

       return (t->tv_sec < -1 || t->tv_sec > 100000000 ||
               t->tv_usec < -1 || t->tv_usec > 1000000);
}