/*      $NetBSD: clnt_generic.c,v 1.18 2000/07/06 03:10:34 christos Exp $       */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2010, Oracle America, Inc.
 * All rights reserved.
 *
 * 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) 1986-1996,1998 by Sun Microsystems, Inc.
 * All rights reserved.
 */
#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <stdio.h>
#include <errno.h>
#include <netdb.h>
#include <syslog.h>
#include <rpc/rpc.h>
#include <rpc/nettype.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "un-namespace.h"
#include "rpc_com.h"

extern bool_t __rpc_is_local_host(const char *);
int __rpc_raise_fd(int);

#ifndef NETIDLEN
#define NETIDLEN 32
#endif


/*
 * Generic client creation with version checking the value of
 * vers_out is set to the highest server supported value
 * vers_low <= vers_out <= vers_high  AND an error results
 * if this can not be done.
 *
 * It calls clnt_create_vers_timed() with a NULL value for the timeout
 * pointer, which indicates that the default timeout should be used.
 */
CLIENT *
clnt_create_vers(const char *hostname, rpcprog_t prog, rpcvers_t *vers_out,
        rpcvers_t vers_low, rpcvers_t vers_high, const char *nettype)
{

        return (clnt_create_vers_timed(hostname, prog, vers_out, vers_low,
                                vers_high, nettype, NULL));
}

/*
 * This the routine has the same definition as clnt_create_vers(),
 * except it takes an additional timeout parameter - a pointer to
 * a timeval structure.  A NULL value for the pointer indicates
 * that the default timeout value should be used.
 */
CLIENT *
clnt_create_vers_timed(const char *hostname, rpcprog_t prog,
    rpcvers_t *vers_out, rpcvers_t vers_low, rpcvers_t vers_high,
    const char *nettype, const struct timeval *tp)
{
        CLIENT *clnt;
        struct timeval to;
        enum clnt_stat rpc_stat;
        struct rpc_err rpcerr;

        clnt = clnt_create_timed(hostname, prog, vers_high, nettype, tp);
        if (clnt == NULL) {
                return (NULL);
        }
        to.tv_sec = 10;
        to.tv_usec = 0;
        rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
                        (char *)NULL, (xdrproc_t)xdr_void, (char *)NULL, to);
        if (rpc_stat == RPC_SUCCESS) {
                *vers_out = vers_high;
                return (clnt);
        }
        while (rpc_stat == RPC_PROGVERSMISMATCH && vers_high > vers_low) {
                unsigned int minvers, maxvers;

                clnt_geterr(clnt, &rpcerr);
                minvers = rpcerr.re_vers.low;
                maxvers = rpcerr.re_vers.high;
                if (maxvers < vers_high)
                        vers_high = maxvers;
                else
                        vers_high--;
                if (minvers > vers_low)
                        vers_low = minvers;
                if (vers_low > vers_high) {
                        goto error;
                }
                CLNT_CONTROL(clnt, CLSET_VERS, (char *)&vers_high);
                rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
                                (char *)NULL, (xdrproc_t)xdr_void,
                                (char *)NULL, to);
                if (rpc_stat == RPC_SUCCESS) {
                        *vers_out = vers_high;
                        return (clnt);
                }
        }
        clnt_geterr(clnt, &rpcerr);

error:
        rpc_createerr.cf_stat = rpc_stat;
        rpc_createerr.cf_error = rpcerr;
        clnt_destroy(clnt);
        return (NULL);
}

/*
 * Top level client creation routine.
 * Generic client creation: takes (servers name, program-number, nettype) and
 * returns client handle. Default options are set, which the user can
 * change using the rpc equivalent of _ioctl()'s.
 *
 * It tries for all the netids in that particular class of netid until
 * it succeeds.
 * XXX The error message in the case of failure will be the one
 * pertaining to the last create error.
 *
 * It calls clnt_create_timed() with the default timeout.
 */
CLIENT *
clnt_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
    const char *nettype)
{

        return (clnt_create_timed(hostname, prog, vers, nettype, NULL));
}

/*
 * This the routine has the same definition as clnt_create(),
 * except it takes an additional timeout parameter - a pointer to
 * a timeval structure.  A NULL value for the pointer indicates
 * that the default timeout value should be used.
 *
 * This function calls clnt_tp_create_timed().
 */
CLIENT *
clnt_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
    const char *netclass, const struct timeval *tp)
{
        struct netconfig *nconf;
        CLIENT *clnt = NULL;
        void *handle;
        enum clnt_stat  save_cf_stat = RPC_SUCCESS;
        struct rpc_err  save_cf_error;
        char nettype_array[NETIDLEN];
        char *nettype = &nettype_array[0];

        if (netclass == NULL)
                nettype = NULL;
        else {
                size_t len = strlen(netclass);
                if (len >= sizeof (nettype_array)) {
                        rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        return (NULL);
                }
                strcpy(nettype, netclass);
        }

        if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (NULL);
        }
        rpc_createerr.cf_stat = RPC_SUCCESS;
        while (clnt == NULL) {
                if ((nconf = __rpc_getconf(handle)) == NULL) {
                        if (rpc_createerr.cf_stat == RPC_SUCCESS)
                                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        break;
                }
#ifdef CLNT_DEBUG
                printf("trying netid %s\n", nconf->nc_netid);
#endif
                clnt = clnt_tp_create_timed(hostname, prog, vers, nconf, tp);
                if (clnt)
                        break;
                else
                        /*
                         *      Since we didn't get a name-to-address
                         *      translation failure here, we remember
                         *      this particular error.  The object of
                         *      this is to enable us to return to the
                         *      caller a more-specific error than the
                         *      unhelpful ``Name to address translation
                         *      failed'' which might well occur if we
                         *      merely returned the last error (because
                         *      the local loopbacks are typically the
                         *      last ones in /etc/netconfig and the most
                         *      likely to be unable to translate a host
                         *      name).  We also check for a more
                         *      meaningful error than ``unknown host
                         *      name'' for the same reasons.
                         */
                        if (rpc_createerr.cf_stat != RPC_N2AXLATEFAILURE &&
                            rpc_createerr.cf_stat != RPC_UNKNOWNHOST) {
                                save_cf_stat = rpc_createerr.cf_stat;
                                save_cf_error = rpc_createerr.cf_error;
                        }
        }

        /*
         *      Attempt to return an error more specific than ``Name to address
         *      translation failed'' or ``unknown host name''
         */
        if ((rpc_createerr.cf_stat == RPC_N2AXLATEFAILURE ||
                                rpc_createerr.cf_stat == RPC_UNKNOWNHOST) &&
                                        (save_cf_stat != RPC_SUCCESS)) {
                rpc_createerr.cf_stat = save_cf_stat;
                rpc_createerr.cf_error = save_cf_error;
        }
        __rpc_endconf(handle);
        return (clnt);
}

/*
 * Generic client creation: takes (servers name, program-number, netconf) and
 * returns client handle. Default options are set, which the user can
 * change using the rpc equivalent of _ioctl()'s : clnt_control()
 * It finds out the server address from rpcbind and calls clnt_tli_create().
 *
 * It calls clnt_tp_create_timed() with the default timeout.
 */
CLIENT *
clnt_tp_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
    const struct netconfig *nconf)
{

        return (clnt_tp_create_timed(hostname, prog, vers, nconf, NULL));
}

/*
 * This has the same definition as clnt_tp_create(), except it
 * takes an additional parameter - a pointer to a timeval structure.
 * A NULL value for the timeout pointer indicates that the default
 * value for the timeout should be used.
 */
CLIENT *
clnt_tp_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
    const struct netconfig *nconf, const struct timeval *tp)
{
        struct netbuf *svcaddr;                 /* servers address */
        CLIENT *cl = NULL;                      /* client handle */

        if (nconf == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (NULL);
        }

        /*
         * Get the address of the server
         */
        if ((svcaddr = __rpcb_findaddr_timed(prog, vers,
                        (struct netconfig *)nconf, (char *)hostname,
                        &cl, (struct timeval *)tp)) == NULL) {
                /* appropriate error number is set by rpcbind libraries */
                return (NULL);
        }
        if (cl == NULL) {
                cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
                                        prog, vers, 0, 0);
        } else {
                /* Reuse the CLIENT handle and change the appropriate fields */
                if (CLNT_CONTROL(cl, CLSET_SVC_ADDR, (void *)svcaddr) == TRUE) {
                        if (cl->cl_netid == NULL)
                                cl->cl_netid = strdup(nconf->nc_netid);
                        if (cl->cl_tp == NULL)
                                cl->cl_tp = strdup(nconf->nc_device);
                        (void) CLNT_CONTROL(cl, CLSET_PROG, (void *)&prog);
                        (void) CLNT_CONTROL(cl, CLSET_VERS, (void *)&vers);
                } else {
                        CLNT_DESTROY(cl);
                        cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
                                        prog, vers, 0, 0);
                }
        }
        free(svcaddr->buf);
        free(svcaddr);
        return (cl);
}

/*
 * Generic client creation:  returns client handle.
 * Default options are set, which the user can
 * change using the rpc equivalent of _ioctl()'s : clnt_control().
 * If fd is RPC_ANYFD, it will be opened using nconf.
 * It will be bound if not so.
 * If sizes are 0; appropriate defaults will be chosen.
 */
CLIENT *
clnt_tli_create(int fd, const struct netconfig *nconf,
        struct netbuf *svcaddr, rpcprog_t prog, rpcvers_t vers,
        uint sendsz, uint recvsz)
{
        CLIENT *cl;                     /* client handle */
        bool_t madefd = FALSE;          /* whether fd opened here */
        long servtype;
        int one = 1;
        struct __rpc_sockinfo si;
        extern int __rpc_minfd;

        if (fd == RPC_ANYFD) {
                if (nconf == NULL) {
                        rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        return (NULL);
                }

                fd = __rpc_nconf2fd(nconf);

                if (fd == -1)
                        goto err;
                if (fd < __rpc_minfd)
                        fd = __rpc_raise_fd(fd);
                madefd = TRUE;
                servtype = nconf->nc_semantics;
                if (!__rpc_fd2sockinfo(fd, &si))
                        goto err;
                bindresvport(fd, NULL);
        } else {
                if (!__rpc_fd2sockinfo(fd, &si))
                        goto err;
                servtype = __rpc_socktype2seman(si.si_socktype);
                if (servtype == -1) {
                        rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        return (NULL);
                }
        }

        if (si.si_af != ((struct sockaddr *)svcaddr->buf)->sa_family) {
                rpc_createerr.cf_stat = RPC_UNKNOWNHOST;        /* XXX */
                goto err1;
        }

        switch (servtype) {
        case NC_TPI_COTS:
                cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
                break;
        case NC_TPI_COTS_ORD:
                if (nconf && ((strcmp(nconf->nc_protofmly, "inet") == 0))) {
                        _setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one,
                            sizeof (one));
                }
                cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
                break;
        case NC_TPI_CLTS:
                cl = clnt_dg_create(fd, svcaddr, prog, vers, sendsz, recvsz);
                break;
        default:
                goto err;
        }

        if (cl == NULL)
                goto err1; /* borrow errors from clnt_dg/vc creates */
        if (nconf) {
                cl->cl_netid = strdup(nconf->nc_netid);
                cl->cl_tp = strdup(nconf->nc_device);
        } else {
                cl->cl_netid = "";
                cl->cl_tp = "";
        }
        if (madefd) {
                (void) CLNT_CONTROL(cl, CLSET_FD_CLOSE, NULL);
/*              (void) CLNT_CONTROL(cl, CLSET_POP_TIMOD, NULL);  */
        }

        return (cl);

err:
        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
        rpc_createerr.cf_error.re_errno = errno;
err1:   if (madefd)
                (void)_close(fd);
        return (NULL);
}

/*
 *  To avoid conflicts with the "magic" file descriptors (0, 1, and 2),
 *  we try to not use them.  The __rpc_raise_fd() routine will dup
 *  a descriptor to a higher value.  If we fail to do it, we continue
 *  to use the old one (and hope for the best).
 */
int __rpc_minfd = 3;

int
__rpc_raise_fd(int fd)
{
        int nfd;

        if (fd >= __rpc_minfd)
                return (fd);

        if ((nfd = _fcntl(fd, F_DUPFD, __rpc_minfd)) == -1)
                return (fd);

        if (_fsync(nfd) == -1) {
                _close(nfd);
                return (fd);
        }

        if (_close(fd) == -1) {
                /* this is okay, we will syslog an error, then use the new fd */
                (void) syslog(LOG_ERR,
                        "could not close() fd %d; mem & fd leak", fd);
        }

        return (nfd);
}