/*      $NetBSD: rpcb_clnt.c,v 1.6 2000/07/16 06:41:43 itojun 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.
 */

/*
 * rpcb_clnt.c
 * interface to rpcbind rpc service.
 */

#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/utsname.h>
#include <rpc/rpc.h>
#include <rpc/rpcb_prot.h>
#include <rpc/nettype.h>
#include <netconfig.h>
#ifdef PORTMAP
#include <netinet/in.h>         /* FOR IPPROTO_TCP/UDP definitions */
#include <rpc/pmap_prot.h>
#endif                          /* PORTMAP */
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#include <syslog.h>
#include "un-namespace.h"

#include "rpc_com.h"
#include "mt_misc.h"

static struct timeval tottimeout = { 60, 0 };
static const struct timeval rmttimeout = { 3, 0 };
static struct timeval rpcbrmttime = { 15, 0 };

extern bool_t xdr_wrapstring(XDR *, char **);

static const char nullstring[] = "\000";

#define CACHESIZE 6

struct address_cache {
        char *ac_host;
        char *ac_netid;
        char *ac_uaddr;
        struct netbuf *ac_taddr;
        struct address_cache *ac_next;
};

static struct address_cache *front;
static int cachesize;

#define CLCR_GET_RPCB_TIMEOUT   1
#define CLCR_SET_RPCB_TIMEOUT   2


extern int __rpc_lowvers;

static struct address_cache *check_cache(const char *, const char *);
static void delete_cache(struct netbuf *);
static void add_cache(const char *, const char *, struct netbuf *, char *);
static CLIENT *getclnthandle(const char *, const struct netconfig *, char **);
static CLIENT *local_rpcb(void);
static struct netbuf *got_entry(rpcb_entry_list_ptr, const struct netconfig *);

/*
 * This routine adjusts the timeout used for calls to the remote rpcbind.
 * Also, this routine can be used to set the use of portmapper version 2
 * only when doing rpc_broadcasts
 * These are private routines that may not be provided in future releases.
 */
bool_t
__rpc_control(int request, void *info)
{
        switch (request) {
        case CLCR_GET_RPCB_TIMEOUT:
                *(struct timeval *)info = tottimeout;
                break;
        case CLCR_SET_RPCB_TIMEOUT:
                tottimeout = *(struct timeval *)info;
                break;
        case CLCR_SET_LOWVERS:
                __rpc_lowvers = *(int *)info;
                break;
        case CLCR_GET_LOWVERS:
                *(int *)info = __rpc_lowvers;
                break;
        default:
                return (FALSE);
        }
        return (TRUE);
}

/*
 *      It might seem that a reader/writer lock would be more reasonable here.
 *      However because getclnthandle(), the only user of the cache functions,
 *      may do a delete_cache() operation if a check_cache() fails to return an
 *      address useful to clnt_tli_create(), we may as well use a mutex.
 */
/*
 * As it turns out, if the cache lock is *not* a reader/writer lock, we will
 * block all clnt_create's if we are trying to connect to a host that's down,
 * since the lock will be held all during that time.
 */

/*
 * The routines check_cache(), add_cache(), delete_cache() manage the
 * cache of rpcbind addresses for (host, netid).
 */

static struct address_cache *
check_cache(const char *host, const char *netid)
{
        struct address_cache *cptr;

        /* READ LOCK HELD ON ENTRY: rpcbaddr_cache_lock */

        for (cptr = front; cptr != NULL; cptr = cptr->ac_next) {
                if (!strcmp(cptr->ac_host, host) &&
                    !strcmp(cptr->ac_netid, netid)) {
#ifdef ND_DEBUG
                        fprintf(stderr, "Found cache entry for %s: %s\n",
                                host, netid);
#endif
                        return (cptr);
                }
        }
        return ((struct address_cache *) NULL);
}

static void
delete_cache(struct netbuf *addr)
{
        struct address_cache *cptr, *prevptr = NULL;

        /* WRITE LOCK HELD ON ENTRY: rpcbaddr_cache_lock */
        for (cptr = front; cptr != NULL; cptr = cptr->ac_next) {
                if (!memcmp(cptr->ac_taddr->buf, addr->buf, addr->len)) {
                        free(cptr->ac_host);
                        free(cptr->ac_netid);
                        free(cptr->ac_taddr->buf);
                        free(cptr->ac_taddr);
                        free(cptr->ac_uaddr);
                        if (prevptr)
                                prevptr->ac_next = cptr->ac_next;
                        else
                                front = cptr->ac_next;
                        free(cptr);
                        cachesize--;
                        break;
                }
                prevptr = cptr;
        }
}

static void
add_cache(const char *host, const char *netid, struct netbuf *taddr,
    char *uaddr)
{
        struct address_cache  *ad_cache, *cptr, *prevptr;

        ad_cache = (struct address_cache *)
                        malloc(sizeof (struct address_cache));
        if (!ad_cache) {
                return;
        }
        ad_cache->ac_host = strdup(host);
        ad_cache->ac_netid = strdup(netid);
        ad_cache->ac_uaddr = uaddr ? strdup(uaddr) : NULL;
        ad_cache->ac_taddr = (struct netbuf *)malloc(sizeof (struct netbuf));
        if (!ad_cache->ac_host || !ad_cache->ac_netid || !ad_cache->ac_taddr ||
                (uaddr && !ad_cache->ac_uaddr)) {
                goto out;
        }
        ad_cache->ac_taddr->len = ad_cache->ac_taddr->maxlen = taddr->len;
        ad_cache->ac_taddr->buf = (char *) malloc(taddr->len);
        if (ad_cache->ac_taddr->buf == NULL) {
out:
                free(ad_cache->ac_host);
                free(ad_cache->ac_netid);
                free(ad_cache->ac_uaddr);
                free(ad_cache->ac_taddr);
                free(ad_cache);
                return;
        }
        memcpy(ad_cache->ac_taddr->buf, taddr->buf, taddr->len);
#ifdef ND_DEBUG
        fprintf(stderr, "Added to cache: %s : %s\n", host, netid);
#endif

/* VARIABLES PROTECTED BY rpcbaddr_cache_lock:  cptr */

        rwlock_wrlock(&rpcbaddr_cache_lock);
        if (cachesize < CACHESIZE) {
                ad_cache->ac_next = front;
                front = ad_cache;
                cachesize++;
        } else {
                /* Free the last entry */
                cptr = front;
                prevptr = NULL;
                while (cptr->ac_next) {
                        prevptr = cptr;
                        cptr = cptr->ac_next;
                }

#ifdef ND_DEBUG
                fprintf(stderr, "Deleted from cache: %s : %s\n",
                        cptr->ac_host, cptr->ac_netid);
#endif
                free(cptr->ac_host);
                free(cptr->ac_netid);
                free(cptr->ac_taddr->buf);
                free(cptr->ac_taddr);
                free(cptr->ac_uaddr);

                if (prevptr) {
                        prevptr->ac_next = NULL;
                        ad_cache->ac_next = front;
                        front = ad_cache;
                } else {
                        front = ad_cache;
                        ad_cache->ac_next = NULL;
                }
                free(cptr);
        }
        rwlock_unlock(&rpcbaddr_cache_lock);
}

/*
 * This routine will return a client handle that is connected to the
 * rpcbind. If targaddr is non-NULL, the "universal address" of the
 * host will be stored in *targaddr; the caller is responsible for
 * freeing this string.
 * On error, returns NULL and free's everything.
 */
static CLIENT *
getclnthandle(const char *host, const struct netconfig *nconf, char **targaddr)
{
        CLIENT *client;
        struct netbuf *addr, taddr;
        struct netbuf addr_to_delete;
        struct __rpc_sockinfo si;
        struct addrinfo hints, *res, *tres;
        struct address_cache *ad_cache;
        char *tmpaddr;

/* VARIABLES PROTECTED BY rpcbaddr_cache_lock:  ad_cache */

        /* Get the address of the rpcbind.  Check cache first */
        client = NULL;
        addr_to_delete.len = 0;
        rwlock_rdlock(&rpcbaddr_cache_lock);
        ad_cache = NULL;
        if (host != NULL)
                ad_cache = check_cache(host, nconf->nc_netid);
        if (ad_cache != NULL) {
                addr = ad_cache->ac_taddr;
                client = clnt_tli_create(RPC_ANYFD, nconf, addr,
                    (rpcprog_t)RPCBPROG, (rpcvers_t)RPCBVERS4, 0, 0);
                if (client != NULL) {
                        if (targaddr)
                                *targaddr = strdup(ad_cache->ac_uaddr);
                        rwlock_unlock(&rpcbaddr_cache_lock);
                        return (client);
                }
                addr_to_delete.len = addr->len;
                addr_to_delete.buf = (char *)malloc(addr->len);
                if (addr_to_delete.buf == NULL) {
                        addr_to_delete.len = 0;
                } else {
                        memcpy(addr_to_delete.buf, addr->buf, addr->len);
                }
        }
        rwlock_unlock(&rpcbaddr_cache_lock);
        if (addr_to_delete.len != 0) {
                /*
                 * Assume this may be due to cache data being
                 *  outdated
                 */
                rwlock_wrlock(&rpcbaddr_cache_lock);
                delete_cache(&addr_to_delete);
                rwlock_unlock(&rpcbaddr_cache_lock);
                free(addr_to_delete.buf);
        }
        if (!__rpc_nconf2sockinfo(nconf, &si)) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return NULL;
        }

        memset(&hints, 0, sizeof hints);
        hints.ai_family = si.si_af;
        hints.ai_socktype = si.si_socktype;
        hints.ai_protocol = si.si_proto;

#ifdef CLNT_DEBUG
        printf("trying netid %s family %d proto %d socktype %d\n",
            nconf->nc_netid, si.si_af, si.si_proto, si.si_socktype);
#endif

        if (nconf->nc_protofmly != NULL && strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
                client = local_rpcb();
                if (! client) {
#ifdef ND_DEBUG
                        clnt_pcreateerror("rpcbind clnt interface");
#endif
                        return (NULL);
                } else {
                        struct sockaddr_un sun;
                        if (targaddr) {
                            *targaddr = malloc(sizeof(sun.sun_path));
                            if (*targaddr == NULL) {
                                CLNT_DESTROY(client);
                                return (NULL);
                            }
                            strncpy(*targaddr, _PATH_RPCBINDSOCK,
                                sizeof(sun.sun_path));
                        }
                        return (client);
                }
        } else {
                if (getaddrinfo(host, "sunrpc", &hints, &res) != 0) {
                        rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
                        return NULL;
                }
        }

        for (tres = res; tres != NULL; tres = tres->ai_next) {
                taddr.buf = tres->ai_addr;
                taddr.len = taddr.maxlen = tres->ai_addrlen;

#ifdef ND_DEBUG
                {
                        char *ua;

                        ua = taddr2uaddr(nconf, &taddr);
                        fprintf(stderr, "Got it [%s]\n", ua);
                        free(ua);
                }
#endif

#ifdef ND_DEBUG
                {
                        int i;

                        fprintf(stderr, "\tnetbuf len = %d, maxlen = %d\n",
                                taddr.len, taddr.maxlen);
                        fprintf(stderr, "\tAddress is ");
                        for (i = 0; i < taddr.len; i++)
                                fprintf(stderr, "%u.", ((char *)(taddr.buf))[i]);
                        fprintf(stderr, "\n");
                }
#endif
                client = clnt_tli_create(RPC_ANYFD, nconf, &taddr,
                    (rpcprog_t)RPCBPROG, (rpcvers_t)RPCBVERS4, 0, 0);
#ifdef ND_DEBUG
                if (! client) {
                        clnt_pcreateerror("rpcbind clnt interface");
                }
#endif

                if (client) {
                        tmpaddr = targaddr ? taddr2uaddr(nconf, &taddr) : NULL;
                        add_cache(host, nconf->nc_netid, &taddr, tmpaddr);
                        if (targaddr)
                                *targaddr = tmpaddr;
                        break;
                }
        }
        if (res)
                freeaddrinfo(res);
        return (client);
}

/* XXX */
#define IN4_LOCALHOST_STRING    "127.0.0.1"
#define IN6_LOCALHOST_STRING    "::1"

/*
 * This routine will return a client handle that is connected to the local
 * rpcbind. Returns NULL on error and free's everything.
 */
static CLIENT *
local_rpcb(void)
{
        CLIENT *client;
        static struct netconfig *loopnconf;
        static char *hostname;
        int sock;
        size_t tsize;
        struct netbuf nbuf;
        struct sockaddr_un sun;

        /*
         * Try connecting to the local rpcbind through a local socket
         * first. If this doesn't work, try all transports defined in
         * the netconfig file.
         */
        memset(&sun, 0, sizeof sun);
        sock = _socket(AF_LOCAL, SOCK_STREAM, 0);
        if (sock < 0)
                goto try_nconf;
        sun.sun_family = AF_LOCAL;
        strcpy(sun.sun_path, _PATH_RPCBINDSOCK);
        nbuf.len = sun.sun_len = SUN_LEN(&sun);
        nbuf.maxlen = sizeof (struct sockaddr_un);
        nbuf.buf = &sun;

        tsize = __rpc_get_t_size(AF_LOCAL, 0, 0);
        client = clnt_vc_create(sock, &nbuf, (rpcprog_t)RPCBPROG,
            (rpcvers_t)RPCBVERS, tsize, tsize);

        if (client != NULL) {
                /* Mark the socket to be closed in destructor */
                (void) CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
                return client;
        }

        /* Nobody needs this socket anymore; free the descriptor. */
        _close(sock);

try_nconf:

/* VARIABLES PROTECTED BY loopnconf_lock: loopnconf */
        mutex_lock(&loopnconf_lock);
        if (loopnconf == NULL) {
                struct netconfig *nconf, *tmpnconf = NULL;
                void *nc_handle;
                int fd;

                nc_handle = setnetconfig();
                if (nc_handle == NULL) {
                        /* fails to open netconfig file */
                        syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
                        rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        mutex_unlock(&loopnconf_lock);
                        return (NULL);
                }
                while ((nconf = getnetconfig(nc_handle)) != NULL) {
#ifdef INET6
                        if ((strcmp(nconf->nc_protofmly, NC_INET6) == 0 ||
#else
                        if ((
#endif
                             strcmp(nconf->nc_protofmly, NC_INET) == 0) &&
                            (nconf->nc_semantics == NC_TPI_COTS ||
                             nconf->nc_semantics == NC_TPI_COTS_ORD)) {
                                fd = __rpc_nconf2fd(nconf);
                                /*
                                 * Can't create a socket, assume that
                                 * this family isn't configured in the kernel.
                                 */
                                if (fd < 0)
                                        continue;
                                _close(fd);
                                tmpnconf = nconf;
                                if (!strcmp(nconf->nc_protofmly, NC_INET))
                                        hostname = IN4_LOCALHOST_STRING;
                                else
                                        hostname = IN6_LOCALHOST_STRING;
                        }
                }
                if (tmpnconf == NULL) {
                        endnetconfig(nc_handle);
                        rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        mutex_unlock(&loopnconf_lock);
                        return (NULL);
                }
                loopnconf = getnetconfigent(tmpnconf->nc_netid);
                /* loopnconf is never freed */
                endnetconfig(nc_handle);
        }
        mutex_unlock(&loopnconf_lock);
        client = getclnthandle(hostname, loopnconf, NULL);
        return (client);
}

/*
 * Set a mapping between program, version and address.
 * Calls the rpcbind service to do the mapping.
 *
 * nconf   - Network structure of transport
 * address - Services netconfig address
 */
bool_t
rpcb_set(rpcprog_t program, rpcvers_t version, const struct netconfig *nconf,
    const struct netbuf *address)
{
        CLIENT *client;
        bool_t rslt = FALSE;
        RPCB parms;
        char uidbuf[32];

        /* parameter checking */
        if (nconf == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (FALSE);
        }
        if (address == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
                return (FALSE);
        }
        client = local_rpcb();
        if (! client) {
                return (FALSE);
        }

        /* convert to universal */
        /*LINTED const castaway*/
        parms.r_addr = taddr2uaddr((struct netconfig *) nconf,
                                   (struct netbuf *)address);
        if (!parms.r_addr) {
                CLNT_DESTROY(client);
                rpc_createerr.cf_stat = RPC_N2AXLATEFAILURE;
                return (FALSE); /* no universal address */
        }
        parms.r_prog = program;
        parms.r_vers = version;
        parms.r_netid = nconf->nc_netid;
        /*
         * Though uid is not being used directly, we still send it for
         * completeness.  For non-unix platforms, perhaps some other
         * string or an empty string can be sent.
         */
        (void) snprintf(uidbuf, sizeof uidbuf, "%d", geteuid());
        parms.r_owner = uidbuf;

        CLNT_CALL(client, (rpcproc_t)RPCBPROC_SET, (xdrproc_t) xdr_rpcb,
            (char *)(void *)&parms, (xdrproc_t) xdr_bool,
            (char *)(void *)&rslt, tottimeout);

        CLNT_DESTROY(client);
        free(parms.r_addr);
        return (rslt);
}

/*
 * Remove the mapping between program, version and netbuf address.
 * Calls the rpcbind service to do the un-mapping.
 * If netbuf is NULL, unset for all the transports, otherwise unset
 * only for the given transport.
 */
bool_t
rpcb_unset(rpcprog_t program, rpcvers_t version, const struct netconfig *nconf)
{
        CLIENT *client;
        bool_t rslt = FALSE;
        RPCB parms;
        char uidbuf[32];

        client = local_rpcb();
        if (! client) {
                return (FALSE);
        }

        parms.r_prog = program;
        parms.r_vers = version;
        if (nconf)
                parms.r_netid = nconf->nc_netid;
        else {
                /*LINTED const castaway*/
                parms.r_netid = (char *) &nullstring[0]; /* unsets  all */
        }
        /*LINTED const castaway*/
        parms.r_addr = (char *) &nullstring[0];
        (void) snprintf(uidbuf, sizeof uidbuf, "%d", geteuid());
        parms.r_owner = uidbuf;

        CLNT_CALL(client, (rpcproc_t)RPCBPROC_UNSET, (xdrproc_t) xdr_rpcb,
            (char *)(void *)&parms, (xdrproc_t) xdr_bool,
            (char *)(void *)&rslt, tottimeout);

        CLNT_DESTROY(client);
        return (rslt);
}

/*
 * From the merged list, find the appropriate entry
 */
static struct netbuf *
got_entry(rpcb_entry_list_ptr relp, const struct netconfig *nconf)
{
        struct netbuf *na = NULL;
        rpcb_entry_list_ptr sp;
        rpcb_entry *rmap;

        for (sp = relp; sp != NULL; sp = sp->rpcb_entry_next) {
                rmap = &sp->rpcb_entry_map;
                if ((strcmp(nconf->nc_proto, rmap->r_nc_proto) == 0) &&
                    (strcmp(nconf->nc_protofmly, rmap->r_nc_protofmly) == 0) &&
                    (nconf->nc_semantics == rmap->r_nc_semantics) &&
                    (rmap->r_maddr != NULL) && (rmap->r_maddr[0] != 0)) {
                        na = uaddr2taddr(nconf, rmap->r_maddr);
#ifdef ND_DEBUG
                        fprintf(stderr, "\tRemote address is [%s].\n",
                                rmap->r_maddr);
                        if (!na)
                                fprintf(stderr,
                                    "\tCouldn't resolve remote address!\n");
#endif
                        break;
                }
        }
        return (na);
}

/*
 * Quick check to see if rpcbind is up.  Tries to connect over
 * local transport.
 */
static bool_t
__rpcbind_is_up(void)
{
        struct netconfig *nconf;
        struct sockaddr_un sun;
        void *localhandle;
        int sock;

        nconf = NULL;
        localhandle = setnetconfig();
        while ((nconf = getnetconfig(localhandle)) != NULL) {
                if (nconf->nc_protofmly != NULL &&
                    strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0)
                         break;
        }
        endnetconfig(localhandle);

        if (nconf == NULL)
                return (FALSE);

        memset(&sun, 0, sizeof sun);
        sock = _socket(AF_LOCAL, SOCK_STREAM, 0);
        if (sock < 0)
                return (FALSE);
        sun.sun_family = AF_LOCAL;
        strncpy(sun.sun_path, _PATH_RPCBINDSOCK, sizeof(sun.sun_path));
        sun.sun_len = SUN_LEN(&sun);

        if (_connect(sock, (struct sockaddr *)&sun, sun.sun_len) < 0) {
                _close(sock);
                return (FALSE);
        }

        _close(sock);
        return (TRUE);
}

/*
 * An internal function which optimizes rpcb_getaddr function.  It also
 * returns the client handle that it uses to contact the remote rpcbind.
 *
 * The algorithm used: If the transports is TCP or UDP, it first tries
 * version 2 (portmap), 4 and then 3 (svr4).  This order should be
 * changed in the next OS release to 4, 2 and 3.  We are assuming that by
 * that time, version 4 would be available on many machines on the network.
 * With this algorithm, we get performance as well as a plan for
 * obsoleting version 2.
 *
 * For all other transports, the algorithm remains as 4 and then 3.
 *
 * XXX: Due to some problems with t_connect(), we do not reuse the same client
 * handle for COTS cases and hence in these cases we do not return the
 * client handle.  This code will change if t_connect() ever
 * starts working properly.  Also look under clnt_vc.c.
 */
struct netbuf *
__rpcb_findaddr_timed(rpcprog_t program, rpcvers_t version,
    const struct netconfig *nconf, const char *host,
    CLIENT **clpp, struct timeval *tp)
{
        static bool_t check_rpcbind = TRUE;
        CLIENT *client = NULL;
        RPCB parms;
        enum clnt_stat clnt_st;
        char *ua = NULL;
        rpcvers_t vers;
        struct netbuf *address = NULL;
        rpcvers_t start_vers = RPCBVERS4;
        struct netbuf servaddr;

        /* parameter checking */
        if (nconf == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (NULL);
        }

        parms.r_addr = NULL;

        /*
         * Use default total timeout if no timeout is specified.
         */
        if (tp == NULL)
                tp = &tottimeout;

#ifdef PORTMAP
        /* Try version 2 for TCP or UDP */
        if (strcmp(nconf->nc_protofmly, NC_INET) == 0) {
                u_short port = 0;
                struct netbuf remote;
                rpcvers_t pmapvers = 2;
                struct pmap pmapparms;

                /*
                 * The comment below is now very old, having
                 * been committed to FreeBSD during an import
                 * from NetBSD in 2001.  I do not believe there
                 * will still be any rpcbind servers that do
                 * UDP only and, since Azure requires use of
                 * TCP for NFSv3 mounts, comment this out
                 * so that NFSv3 mounts on Azure can work.
                 */
#ifdef notnow
                /*
                 * Try UDP only - there are some portmappers out
                 * there that use UDP only.
                 */
                if (strcmp(nconf->nc_proto, NC_TCP) == 0) {
                        struct netconfig *newnconf;

                        if ((newnconf = getnetconfigent("udp")) == NULL) {
                                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                                return (NULL);
                        }
                        client = getclnthandle(host, newnconf, &parms.r_addr);
                        freenetconfigent(newnconf);
                } else
#endif
                        client = getclnthandle(host, nconf, &parms.r_addr);
                if (client == NULL)
                        return (NULL);

                /*
                 * Set version and retry timeout.
                 */
                CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)&rpcbrmttime);
                CLNT_CONTROL(client, CLSET_VERS, (char *)&pmapvers);

                pmapparms.pm_prog = program;
                pmapparms.pm_vers = version;
                pmapparms.pm_prot = strcmp(nconf->nc_proto, NC_TCP) ?
                                        IPPROTO_UDP : IPPROTO_TCP;
                pmapparms.pm_port = 0;  /* not needed */
                clnt_st = CLNT_CALL(client, (rpcproc_t)PMAPPROC_GETPORT,
                    (xdrproc_t) xdr_pmap, (caddr_t)(void *)&pmapparms,
                    (xdrproc_t) xdr_u_short, (caddr_t)(void *)&port,
                    *tp);
                if (clnt_st != RPC_SUCCESS) {
                        if ((clnt_st == RPC_PROGVERSMISMATCH) ||
                                (clnt_st == RPC_PROGUNAVAIL))
                                goto try_rpcbind; /* Try different versions */
                        rpc_createerr.cf_stat = RPC_PMAPFAILURE;
                        clnt_geterr(client, &rpc_createerr.cf_error);
                        goto error;
                } else if (port == 0) {
                        address = NULL;
                        rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
                        goto error;
                }
                port = htons(port);
                CLNT_CONTROL(client, CLGET_SVC_ADDR, (char *)&remote);
                if (((address = (struct netbuf *)
                        malloc(sizeof (struct netbuf))) == NULL) ||
                    ((address->buf = (char *)
                        malloc(remote.len)) == NULL)) {
                        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                        clnt_geterr(client, &rpc_createerr.cf_error);
                        free(address);
                        address = NULL;
                        goto error;
                }
                memcpy(address->buf, remote.buf, remote.len);
                memcpy(&((char *)address->buf)[sizeof (short)],
                                (char *)(void *)&port, sizeof (short));
                address->len = address->maxlen = remote.len;
                goto done;
        }
#endif                          /* PORTMAP */

try_rpcbind:
        /*
         * Check if rpcbind is up.  This prevents needless delays when
         * accessing applications such as the keyserver while booting
         * disklessly.
         */
        if (check_rpcbind && strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
                if (!__rpcbind_is_up()) {
                        rpc_createerr.cf_stat = RPC_PMAPFAILURE;
                        rpc_createerr.cf_error.re_errno = 0;
                        goto error;
                }
                check_rpcbind = FALSE;
        }

        /*
         * Now we try version 4 and then 3.
         * We also send the remote system the address we used to
         * contact it in case it can help to connect back with us
         */
        parms.r_prog = program;
        parms.r_vers = version;
        /*LINTED const castaway*/
        parms.r_owner = (char *) &nullstring[0];        /* not needed; */
                                                        /* just for xdring */
        parms.r_netid = nconf->nc_netid; /* not really needed */

        /*
         * If a COTS transport is being used, try getting address via CLTS
         * transport.  This works only with version 4.
         */
        if (nconf->nc_semantics == NC_TPI_COTS_ORD ||
                        nconf->nc_semantics == NC_TPI_COTS) {

                void *handle;
                struct netconfig *nconf_clts;
                rpcb_entry_list_ptr relp = NULL;

                if (client == NULL) {
                        /* This did not go through the above PORTMAP/TCP code */
                        if ((handle = __rpc_setconf("datagram_v")) != NULL) {
                                while ((nconf_clts = __rpc_getconf(handle))
                                        != NULL) {
                                        if (strcmp(nconf_clts->nc_protofmly,
                                                nconf->nc_protofmly) != 0) {
                                                continue;
                                        }
                                        client = getclnthandle(host, nconf_clts,
                                                        &parms.r_addr);
                                        break;
                                }
                                __rpc_endconf(handle);
                        }
                        if (client == NULL)
                                goto regular_rpcbind;   /* Go the regular way */
                } else {
                        /* This is a UDP PORTMAP handle.  Change to version 4 */
                        vers = RPCBVERS4;
                        CLNT_CONTROL(client, CLSET_VERS, (char *)(void *)&vers);
                }
                /*
                 * We also send the remote system the address we used to
                 * contact it in case it can help it connect back with us
                 */
                if (parms.r_addr == NULL) {
                        /*LINTED const castaway*/
                        parms.r_addr = (char *) &nullstring[0]; /* for XDRing */
                }

                CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)&rpcbrmttime);

                clnt_st = CLNT_CALL(client, (rpcproc_t)RPCBPROC_GETADDRLIST,
                    (xdrproc_t) xdr_rpcb, (char *)(void *)&parms,
                    (xdrproc_t) xdr_rpcb_entry_list_ptr,
                    (char *)(void *)&relp, *tp);
                if (clnt_st == RPC_SUCCESS) {
                        if ((address = got_entry(relp, nconf)) != NULL) {
                                xdr_free((xdrproc_t) xdr_rpcb_entry_list_ptr,
                                    (char *)(void *)&relp);
                                CLNT_CONTROL(client, CLGET_SVC_ADDR,
                                        (char *)(void *)&servaddr);
                                __rpc_fixup_addr(address, &servaddr);
                                goto done;
                        }
                        /* Entry not found for this transport */
                        xdr_free((xdrproc_t) xdr_rpcb_entry_list_ptr,
                            (char *)(void *)&relp);
                        /*
                         * XXX: should have perhaps returned with error but
                         * since the remote machine might not always be able
                         * to send the address on all transports, we try the
                         * regular way with regular_rpcbind
                         */
                        goto regular_rpcbind;
                } else if ((clnt_st == RPC_PROGVERSMISMATCH) ||
                        (clnt_st == RPC_PROGUNAVAIL)) {
                        start_vers = RPCBVERS;  /* Try version 3 now */
                        goto regular_rpcbind; /* Try different versions */
                } else {
                        rpc_createerr.cf_stat = RPC_PMAPFAILURE;
                        clnt_geterr(client, &rpc_createerr.cf_error);
                        goto error;
                }
        }

regular_rpcbind:

        /* Now the same transport is to be used to get the address */
        if (client && ((nconf->nc_semantics == NC_TPI_COTS_ORD) ||
                        (nconf->nc_semantics == NC_TPI_COTS))) {
                /* A CLTS type of client - destroy it */
                CLNT_DESTROY(client);
                client = NULL;
        }

        if (client == NULL) {
                client = getclnthandle(host, nconf, &parms.r_addr);
                if (client == NULL) {
                        goto error;
                }
        }
        if (parms.r_addr == NULL) {
                /*LINTED const castaway*/
                parms.r_addr = (char *) &nullstring[0];
        }

        /* First try from start_vers and then version 3 (RPCBVERS) */

        CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *) &rpcbrmttime);
        for (vers = start_vers;  vers >= RPCBVERS; vers--) {
                /* Set the version */
                CLNT_CONTROL(client, CLSET_VERS, (char *)(void *)&vers);
                clnt_st = CLNT_CALL(client, (rpcproc_t)RPCBPROC_GETADDR,
                    (xdrproc_t) xdr_rpcb, (char *)(void *)&parms,
                    (xdrproc_t) xdr_wrapstring, (char *)(void *) &ua, *tp);
                if (clnt_st == RPC_SUCCESS) {
                        if ((ua == NULL) || (ua[0] == 0)) {
                                /* address unknown */
                                rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
                                goto error;
                        }
                        address = uaddr2taddr(nconf, ua);
#ifdef ND_DEBUG
                        fprintf(stderr, "\tRemote address is [%s]\n", ua);
                        if (!address)
                                fprintf(stderr,
                                        "\tCouldn't resolve remote address!\n");
#endif
                        xdr_free((xdrproc_t)xdr_wrapstring,
                            (char *)(void *)&ua);

                        if (! address) {
                                /* We don't know about your universal address */
                                rpc_createerr.cf_stat = RPC_N2AXLATEFAILURE;
                                goto error;
                        }
                        CLNT_CONTROL(client, CLGET_SVC_ADDR,
                            (char *)(void *)&servaddr);
                        __rpc_fixup_addr(address, &servaddr);
                        goto done;
                } else if (clnt_st == RPC_PROGVERSMISMATCH) {
                        struct rpc_err rpcerr;

                        clnt_geterr(client, &rpcerr);
                        if (rpcerr.re_vers.low > RPCBVERS4)
                                goto error;  /* a new version, can't handle */
                } else if (clnt_st != RPC_PROGUNAVAIL) {
                        /* Cant handle this error */
                        rpc_createerr.cf_stat = clnt_st;
                        clnt_geterr(client, &rpc_createerr.cf_error);
                        goto error;
                }
        }

error:
        if (client) {
                CLNT_DESTROY(client);
                client = NULL;
        }
done:
        if (nconf->nc_semantics != NC_TPI_CLTS) {
                /* This client is the connectionless one */
                if (client) {
                        CLNT_DESTROY(client);
                        client = NULL;
                }
        }
        if (clpp) {
                *clpp = client;
        } else if (client) {
                CLNT_DESTROY(client);
        }
        if (parms.r_addr != NULL && parms.r_addr != nullstring)
                free(parms.r_addr);
        return (address);
}


/*
 * Find the mapped address for program, version.
 * Calls the rpcbind service remotely to do the lookup.
 * Uses the transport specified in nconf.
 * Returns FALSE (0) if no map exists, else returns 1.
 *
 * Assuming that the address is all properly allocated
 */
bool_t
rpcb_getaddr(rpcprog_t program, rpcvers_t version, const struct netconfig *nconf,
    struct netbuf *address, const char *host)
{
        struct netbuf *na;

        if ((na = __rpcb_findaddr_timed(program, version,
            (struct netconfig *) nconf, (char *) host,
            (CLIENT **) NULL, (struct timeval *) NULL)) == NULL)
                return (FALSE);

        if (na->len > address->maxlen) {
                /* Too long address */
                free(na->buf);
                free(na);
                rpc_createerr.cf_stat = RPC_FAILED;
                return (FALSE);
        }
        memcpy(address->buf, na->buf, (size_t)na->len);
        address->len = na->len;
        free(na->buf);
        free(na);
        return (TRUE);
}

/*
 * Get a copy of the current maps.
 * Calls the rpcbind service remotely to get the maps.
 *
 * It returns only a list of the services
 * It returns NULL on failure.
 */
rpcblist *
rpcb_getmaps(const struct netconfig *nconf, const char *host)
{
        rpcblist_ptr head = NULL;
        CLIENT *client;
        enum clnt_stat clnt_st;
        rpcvers_t vers = 0;

        client = getclnthandle(host, nconf, NULL);
        if (client == NULL) {
                return (head);
        }
        clnt_st = CLNT_CALL(client, (rpcproc_t)RPCBPROC_DUMP,
            (xdrproc_t) xdr_void, NULL, (xdrproc_t) xdr_rpcblist_ptr,
            (char *)(void *)&head, tottimeout);
        if (clnt_st == RPC_SUCCESS)
                goto done;

        if ((clnt_st != RPC_PROGVERSMISMATCH) &&
            (clnt_st != RPC_PROGUNAVAIL)) {
                rpc_createerr.cf_stat = RPC_RPCBFAILURE;
                clnt_geterr(client, &rpc_createerr.cf_error);
                goto done;
        }

        /* fall back to earlier version */
        CLNT_CONTROL(client, CLGET_VERS, (char *)(void *)&vers);
        if (vers == RPCBVERS4) {
                vers = RPCBVERS;
                CLNT_CONTROL(client, CLSET_VERS, (char *)(void *)&vers);
                if (CLNT_CALL(client, (rpcproc_t)RPCBPROC_DUMP,
                    (xdrproc_t) xdr_void, NULL, (xdrproc_t) xdr_rpcblist_ptr,
                    (char *)(void *)&head, tottimeout) == RPC_SUCCESS)
                        goto done;
        }
        rpc_createerr.cf_stat = RPC_RPCBFAILURE;
        clnt_geterr(client, &rpc_createerr.cf_error);

done:
        CLNT_DESTROY(client);
        return (head);
}

/*
 * rpcbinder remote-call-service interface.
 * This routine is used to call the rpcbind remote call service
 * which will look up a service program in the address maps, and then
 * remotely call that routine with the given parameters. This allows
 * programs to do a lookup and call in one step.
 *
 * nconf    -Netconfig structure
 * host     - Remote host name
 * proc     - Remote proc identifiers
 * xdrargs, xdrres;  XDR routines
 * argsp, resp - Argument and Result
 * tout     - Timeout value for this call
 * addr_ptr - Preallocated netbuf address
 */
enum clnt_stat
rpcb_rmtcall(const struct netconfig *nconf, const char *host, rpcprog_t prog,
    rpcvers_t vers, rpcproc_t proc, xdrproc_t xdrargs, caddr_t argsp,
    xdrproc_t xdrres, caddr_t resp, struct timeval tout,
    const struct netbuf *addr_ptr)
{
        CLIENT *client;
        enum clnt_stat stat;
        struct r_rpcb_rmtcallargs a;
        struct r_rpcb_rmtcallres r;
        rpcvers_t rpcb_vers;

        stat = 0;
        client = getclnthandle(host, nconf, NULL);
        if (client == NULL) {
                return (RPC_FAILED);
        }
        /*LINTED const castaway*/
        CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)(void *)&rmttimeout);
        a.prog = prog;
        a.vers = vers;
        a.proc = proc;
        a.args.args_val = argsp;
        a.xdr_args = xdrargs;
        r.addr = NULL;
        r.results.results_val = resp;
        r.xdr_res = xdrres;

        for (rpcb_vers = RPCBVERS4; rpcb_vers >= RPCBVERS; rpcb_vers--) {
                CLNT_CONTROL(client, CLSET_VERS, (char *)(void *)&rpcb_vers);
                stat = CLNT_CALL(client, (rpcproc_t)RPCBPROC_CALLIT,
                    (xdrproc_t) xdr_rpcb_rmtcallargs, (char *)(void *)&a,
                    (xdrproc_t) xdr_rpcb_rmtcallres, (char *)(void *)&r, tout);
                if ((stat == RPC_SUCCESS) && (addr_ptr != NULL)) {
                        struct netbuf *na;
                        /*LINTED const castaway*/
                        na = uaddr2taddr((struct netconfig *) nconf, r.addr);
                        if (!na) {
                                stat = RPC_N2AXLATEFAILURE;
                                /*LINTED const castaway*/
                                ((struct netbuf *) addr_ptr)->len = 0;
                                goto error;
                        }
                        if (na->len > addr_ptr->maxlen) {
                                /* Too long address */
                                stat = RPC_FAILED; /* XXX A better error no */
                                free(na->buf);
                                free(na);
                                /*LINTED const castaway*/
                                ((struct netbuf *) addr_ptr)->len = 0;
                                goto error;
                        }
                        memcpy(addr_ptr->buf, na->buf, (size_t)na->len);
                        /*LINTED const castaway*/
                        ((struct netbuf *)addr_ptr)->len = na->len;
                        free(na->buf);
                        free(na);
                        break;
                } else if ((stat != RPC_PROGVERSMISMATCH) &&
                            (stat != RPC_PROGUNAVAIL)) {
                        goto error;
                }
        }
error:
        CLNT_DESTROY(client);
        if (r.addr)
                xdr_free((xdrproc_t) xdr_wrapstring, (char *)(void *)&r.addr);
        return (stat);
}

/*
 * Gets the time on the remote host.
 * Returns 1 if succeeds else 0.
 */
bool_t
rpcb_gettime(const char *host, time_t *timep)
{
        CLIENT *client = NULL;
        void *handle;
        struct netconfig *nconf;
        rpcvers_t vers;
        enum clnt_stat st;


        if ((host == NULL) || (host[0] == 0)) {
                time(timep);
                return (TRUE);
        }

        if ((handle = __rpc_setconf("netpath")) == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (FALSE);
        }
        rpc_createerr.cf_stat = RPC_SUCCESS;
        while (client == NULL) {
                if ((nconf = __rpc_getconf(handle)) == NULL) {
                        if (rpc_createerr.cf_stat == RPC_SUCCESS)
                                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                        break;
                }
                client = getclnthandle(host, nconf, NULL);
                if (client)
                        break;
        }
        __rpc_endconf(handle);
        if (client == (CLIENT *) NULL) {
                return (FALSE);
        }

        st = CLNT_CALL(client, (rpcproc_t)RPCBPROC_GETTIME,
                (xdrproc_t) xdr_void, NULL,
                (xdrproc_t) xdr_int, (char *)(void *)timep, tottimeout);

        if ((st == RPC_PROGVERSMISMATCH) || (st == RPC_PROGUNAVAIL)) {
                CLNT_CONTROL(client, CLGET_VERS, (char *)(void *)&vers);
                if (vers == RPCBVERS4) {
                        /* fall back to earlier version */
                        vers = RPCBVERS;
                        CLNT_CONTROL(client, CLSET_VERS, (char *)(void *)&vers);
                        st = CLNT_CALL(client, (rpcproc_t)RPCBPROC_GETTIME,
                                (xdrproc_t) xdr_void, NULL,
                                (xdrproc_t) xdr_int, (char *)(void *)timep,
                                tottimeout);
                }
        }
        CLNT_DESTROY(client);
        return (st == RPC_SUCCESS? TRUE: FALSE);
}

/*
 * Converts taddr to universal address.  This routine should never
 * really be called because local n2a libraries are always provided.
 */
char *
rpcb_taddr2uaddr(struct netconfig *nconf, struct netbuf *taddr)
{
        CLIENT *client;
        char *uaddr = NULL;


        /* parameter checking */
        if (nconf == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (NULL);
        }
        if (taddr == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
                return (NULL);
        }
        client = local_rpcb();
        if (! client) {
                return (NULL);
        }

        CLNT_CALL(client, (rpcproc_t)RPCBPROC_TADDR2UADDR,
            (xdrproc_t) xdr_netbuf, (char *)(void *)taddr,
            (xdrproc_t) xdr_wrapstring, (char *)(void *)&uaddr, tottimeout);
        CLNT_DESTROY(client);
        return (uaddr);
}

/*
 * Converts universal address to netbuf.  This routine should never
 * really be called because local n2a libraries are always provided.
 */
struct netbuf *
rpcb_uaddr2taddr(struct netconfig *nconf, char *uaddr)
{
        CLIENT *client;
        struct netbuf *taddr;


        /* parameter checking */
        if (nconf == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
                return (NULL);
        }
        if (uaddr == NULL) {
                rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
                return (NULL);
        }
        client = local_rpcb();
        if (! client) {
                return (NULL);
        }

        taddr = (struct netbuf *)calloc(1, sizeof (struct netbuf));
        if (taddr == NULL) {
                CLNT_DESTROY(client);
                return (NULL);
        }
        if (CLNT_CALL(client, (rpcproc_t)RPCBPROC_UADDR2TADDR,
            (xdrproc_t) xdr_wrapstring, (char *)(void *)&uaddr,
            (xdrproc_t) xdr_netbuf, (char *)(void *)taddr,
            tottimeout) != RPC_SUCCESS) {
                free(taddr);
                taddr = NULL;
        }
        CLNT_DESTROY(client);
        return (taddr);
}