libnsl/rpc/rpcb_clnt.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2014 Gary Mills
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the Regents of the University of
 * California.
 */

/*
 * interface to rpcbind rpc service.
 */

#include "mt.h"
#include "rpc_mt.h"
#include <assert.h>
#include <rpc/rpc.h>
#include <rpc/rpcb_prot.h>
#include <netconfig.h>
#include <netdir.h>
#include <netdb.h>
#include <rpc/nettype.h>
#include <syslog.h>
#ifdef PORTMAP
#include <netinet/in.h>		/* FOR IPPROTO_TCP/UDP definitions */
#include <rpc/pmap_prot.h>
#endif
#include <sys/utsname.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.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";

extern CLIENT *_clnt_tli_create_timed(int, const struct netconfig *,
			struct netbuf *, rpcprog_t, rpcvers_t, uint_t, uint_t,
			const struct timeval *);

static CLIENT *_getclnthandle_timed(char *, struct netconfig *, char **,
			struct timeval *);


/*
 * The life time of a cached entry should not exceed 5 minutes
 * since automountd attempts an unmount every 5 minutes.
 * It is arbitrarily set a little lower (3 min = 180 sec)
 * to reduce the time during which an entry is stale.
 */
#define	CACHE_TTL 180
#define	CACHESIZE 6

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

static struct address_cache *front;
static int cachesize;

extern int lowvers;
extern int authdes_cachesz;
/*
 * 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_GET_LOWVERS:
		*(int *)info = lowvers;
		break;
	case CLCR_SET_LOWVERS:
		lowvers = *(int *)info;
		break;
	case CLCR_GET_RPCB_RMTTIME:
		*(struct timeval *)info = rpcbrmttime;
		break;
	case CLCR_SET_RPCB_RMTTIME:
		rpcbrmttime = *(struct timeval *)info;
		break;
	case CLCR_GET_CRED_CACHE_SZ:
		*(int *)info = authdes_cachesz;
		break;
	case CLCR_SET_CRED_CACHE_SZ:
		authdes_cachesz = *(int *)info;
		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.
 */
extern rwlock_t	rpcbaddr_cache_lock;

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

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

	/* READ LOCK HELD ON ENTRY: rpcbaddr_cache_lock */

	assert(RW_READ_HELD(&rpcbaddr_cache_lock));
	for (cptr = front; cptr != NULL; cptr = cptr->ac_next) {
		if ((strcmp(cptr->ac_host, host) == 0) &&
		    (strcmp(cptr->ac_netid, netid) == 0) &&
		    (time(NULL) <= cptr->ac_maxtime)) {
			return (cptr);
		}
	}
	return (NULL);
}

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

	/* WRITE LOCK HELD ON ENTRY: rpcbaddr_cache_lock */
	assert(RW_WRITE_HELD(&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);
			if (cptr->ac_uaddr)
				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(char *host, char *netid, struct netbuf *taddr, char *uaddr)
{
	struct address_cache  *ad_cache, *cptr, *prevptr;

	ad_cache = malloc(sizeof (struct address_cache));
	if (!ad_cache) {
		goto memerr;
	}
	ad_cache->ac_maxtime = time(NULL) + CACHE_TTL;
	ad_cache->ac_host = strdup(host);
	ad_cache->ac_netid = strdup(netid);
	ad_cache->ac_uaddr = uaddr ? strdup(uaddr) : NULL;
	ad_cache->ac_taddr = malloc(sizeof (struct netbuf));
	if (!ad_cache->ac_host || !ad_cache->ac_netid || !ad_cache->ac_taddr ||
	    (uaddr && !ad_cache->ac_uaddr)) {
		goto memerr1;
	}

	ad_cache->ac_taddr->len = ad_cache->ac_taddr->maxlen = taddr->len;
	ad_cache->ac_taddr->buf = malloc(taddr->len);
	if (ad_cache->ac_taddr->buf == NULL) {
		goto memerr1;
	}

	(void) memcpy(ad_cache->ac_taddr->buf, taddr->buf, taddr->len);

/* VARIABLES PROTECTED BY rpcbaddr_cache_lock:  cptr */

	(void) rw_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;
		}

		free(cptr->ac_host);
		free(cptr->ac_netid);
		free(cptr->ac_taddr->buf);
		free(cptr->ac_taddr);
		if (cptr->ac_uaddr)
			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);
	}
	(void) rw_unlock(&rpcbaddr_cache_lock);
	return;
memerr1:
	if (ad_cache->ac_host)
		free(ad_cache->ac_host);
	if (ad_cache->ac_netid)
		free(ad_cache->ac_netid);
	if (ad_cache->ac_uaddr)
		free(ad_cache->ac_uaddr);
	if (ad_cache->ac_taddr)
		free(ad_cache->ac_taddr);
	free(ad_cache);
memerr:
	syslog(LOG_ERR, "add_cache : out of memory.");
}

/*
 * This routine will return a client handle that is connected to the
 * rpcbind. Returns NULL on error and free's everything.
 */
static CLIENT *
getclnthandle(char *host, struct netconfig *nconf, char **targaddr)
{
	return (_getclnthandle_timed(host, nconf, targaddr, NULL));
}

/*
 * Same as getclnthandle() except it takes an extra timeout argument.
 * This is for bug 4049792: clnt_create_timed does not timeout.
 *
 * If tp is NULL, use default timeout to get a client handle.
 */
static CLIENT *
_getclnthandle_timed(char *host, struct netconfig *nconf, char **targaddr,
							struct timeval *tp)
{
	CLIENT *client = NULL;
	struct netbuf *addr;
	struct netbuf addr_to_delete;
	struct nd_addrlist *nas;
	struct nd_hostserv rpcbind_hs;
	struct address_cache *ad_cache;
	char *tmpaddr;
	int neterr;
	int j;

/* VARIABLES PROTECTED BY rpcbaddr_cache_lock:  ad_cache */

	/* Get the address of the rpcbind.  Check cache first */
	addr_to_delete.len = 0;
	(void) rw_rdlock(&rpcbaddr_cache_lock);
	ad_cache = check_cache(host, nconf->nc_netid);
	if (ad_cache != NULL) {
		addr = ad_cache->ac_taddr;
		client = _clnt_tli_create_timed(RPC_ANYFD, nconf, addr,
		    RPCBPROG, RPCBVERS4, 0, 0, tp);
		if (client != NULL) {
			if (targaddr) {
				/*
				 * case where a client handle is created
				 * without a targaddr and the handle is
				 * requested with a targaddr
				 */
				if (ad_cache->ac_uaddr != NULL) {
					*targaddr = strdup(ad_cache->ac_uaddr);
					if (*targaddr == NULL) {
						syslog(LOG_ERR,
						"_getclnthandle_timed: strdup "
						"failed.");
						rpc_createerr.cf_stat =
						    RPC_SYSTEMERROR;
						(void) rw_unlock(
						    &rpcbaddr_cache_lock);
						return (NULL);
					}
				} else {
					*targaddr = NULL;
				}
			}
			(void) rw_unlock(&rpcbaddr_cache_lock);
			return (client);
		}
		if (rpc_createerr.cf_stat == RPC_SYSTEMERROR) {
			(void) rw_unlock(&rpcbaddr_cache_lock);
			return (NULL);
		}
		addr_to_delete.len = addr->len;
		addr_to_delete.buf = malloc(addr->len);
		if (addr_to_delete.buf == NULL) {
			addr_to_delete.len = 0;
		} else {
			(void) memcpy(addr_to_delete.buf, addr->buf, addr->len);
		}
	}
	(void) rw_unlock(&rpcbaddr_cache_lock);
	if (addr_to_delete.len != 0) {
		/*
		 * Assume this may be due to cache data being
		 *  outdated
		 */
		(void) rw_wrlock(&rpcbaddr_cache_lock);
		delete_cache(&addr_to_delete);
		(void) rw_unlock(&rpcbaddr_cache_lock);
		free(addr_to_delete.buf);
	}
	rpcbind_hs.h_host = host;
	rpcbind_hs.h_serv = "rpcbind";

	if ((neterr = netdir_getbyname(nconf, &rpcbind_hs, &nas)) != 0) {
		if (neterr == ND_NOHOST)
			rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
		else
			rpc_createerr.cf_stat = RPC_N2AXLATEFAILURE;
		return (NULL);
	}
	/* XXX nas should perhaps be cached for better performance */

	for (j = 0; j < nas->n_cnt; j++) {
		addr = &(nas->n_addrs[j]);
	client = _clnt_tli_create_timed(RPC_ANYFD, nconf, addr, RPCBPROG,
	    RPCBVERS4, 0, 0, tp);
	if (client)
		break;
	}

	if (client) {
		tmpaddr = targaddr ? taddr2uaddr(nconf, addr) : NULL;
		add_cache(host, nconf->nc_netid, addr, tmpaddr);
		if (targaddr) {
			*targaddr = tmpaddr;
		}
	}
	netdir_free((char *)nas, ND_ADDRLIST);
	return (client);
}

/*
 * This routine will return a client handle that is connected to the local
 * rpcbind. Returns NULL on error.
 */
static CLIENT *
local_rpcb(void)
{
	static struct netconfig *loopnconf;
	static char hostname[MAXHOSTNAMELEN + 1];
	extern mutex_t loopnconf_lock;

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

		if ((hostname[0] == '\0') && (gethostname(hostname,
		    sizeof (hostname)) < 0)) {
			syslog(LOG_ERR, "local_rpcb: gethostname failed.");
			rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
			(void) mutex_unlock(&loopnconf_lock);
			return (NULL);
		}
		nc_handle = setnetconfig();
		if (nc_handle == NULL) {
			/* fails to open netconfig file */
			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
			(void) mutex_unlock(&loopnconf_lock);
			return (NULL);
		}
		while (nconf = getnetconfig(nc_handle)) {
			if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
				tmpnconf = nconf;
				if (nconf->nc_semantics == NC_TPI_CLTS)
					break;
			}
		}
		if (tmpnconf == NULL) {
			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
			(void) mutex_unlock(&loopnconf_lock);
			return (NULL);
		}
		loopnconf = getnetconfigent(tmpnconf->nc_netid);
		/* loopnconf is never freed */
		(void) endnetconfig(nc_handle);
	}
	(void) mutex_unlock(&loopnconf_lock);
	return (getclnthandle(hostname, loopnconf, NULL));
}

/*
 * Set a mapping between program, version and address.
 * Calls the rpcbind service to do the mapping.
 */
bool_t
rpcb_set(const rpcprog_t program, const 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);

	parms.r_addr = taddr2uaddr((struct netconfig *)nconf,
	    (struct netbuf *)address); /* convert to universal */
	if (!parms.r_addr) {
		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) sprintf(uidbuf, "%d", (int)geteuid());
	parms.r_owner = uidbuf;

	CLNT_CALL(client, RPCBPROC_SET, (xdrproc_t)xdr_rpcb, (char *)&parms,
	    (xdrproc_t)xdr_bool, (char *)&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(const rpcprog_t program, const 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
		parms.r_netid = (char *)&nullstring[0]; /* unsets  all */
	parms.r_addr = (char *)&nullstring[0];
	(void) sprintf(uidbuf, "%d", (int)geteuid());
	parms.r_owner = uidbuf;

	CLNT_CALL(client, RPCBPROC_UNSET, (xdrproc_t)xdr_rpcb, (char *)&parms,
	    (xdrproc_t)xdr_bool, (char *)&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, 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] != NULL)) {
			na = uaddr2taddr(nconf, rmap->r_maddr);
			break;
		}
	}
	return (na);
}

/*
 * Quick check to see if rpcbind is up.  Tries to connect over
 * local transport.
 */
bool_t
__rpcbind_is_up(void)
{
	char hostname[MAXHOSTNAMELEN + 1];
	char uaddr[SYS_NMLN];
	struct netbuf *addr;
	int fd;
	struct t_call *sndcall;
	struct netconfig *netconf;
	bool_t res;

	if (gethostname(hostname, sizeof (hostname)) < 0)
		return (TRUE);

	if ((fd = t_open("/dev/ticotsord", O_RDWR, NULL)) == -1)
		return (TRUE);

	if (t_bind(fd, NULL, NULL) == -1) {
		(void) t_close(fd);
		return (TRUE);
	}

	/* LINTED pointer cast */
	if ((sndcall = (struct t_call *)t_alloc(fd, T_CALL, 0)) == NULL) {
		(void) t_close(fd);
		return (TRUE);
	}

	uaddr[0] = '\0';
	(void) strlcpy(uaddr, hostname, sizeof (uaddr) - 5);
	(void) strcat(uaddr, ".rpc");
	if ((netconf = getnetconfigent("ticotsord")) == NULL) {
		(void) t_free((char *)sndcall, T_CALL);
		(void) t_close(fd);
		return (FALSE);
	}
	addr = uaddr2taddr(netconf, uaddr);
	freenetconfigent(netconf);
	if (addr == NULL || addr->buf == NULL) {
		if (addr)
			free(addr);
		(void) t_free((char *)sndcall, T_CALL);
		(void) t_close(fd);
		return (FALSE);
	}
	sndcall->addr.maxlen = addr->maxlen;
	sndcall->addr.len = addr->len;
	sndcall->addr.buf = addr->buf;

	if (t_connect(fd, sndcall, NULL) == -1)
		res = FALSE;
	else
		res = TRUE;

	sndcall->addr.maxlen = sndcall->addr.len = 0;
	sndcall->addr.buf = NULL;
	(void) t_free((char *)sndcall, T_CALL);
	free(addr->buf);
	free(addr);
	(void) t_close(fd);

	return (res);
}


/*
 * An internal function which optimizes rpcb_getaddr function.  It returns
 * the universal address of the remote service or NULL.  It also optionally
 * returns the client handle that it uses to contact the remote rpcbind.
 * The caller will re-purpose the client handle to contact the remote service.
 *
 * The algorithm used: First try version 4.  Then try version 3 (svr4).
 * Finally, if the transport is TCP or UDP, try version 2 (portmap).
 * Version 4 is now available with all current systems on the network.
 * With this algorithm, we get performance as well as a plan for
 * obsoleting version 2.
 *
 * 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,
	struct netconfig *nconf, 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;
	uint_t vers;
	struct netbuf *address = NULL;
	void *handle;
	rpcb_entry_list_ptr relp = NULL;
	bool_t tmp_client = FALSE;

	/* parameter checking */
	if (nconf == NULL) {
		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
		/*
		 * Setting rpc_createerr.cf_stat is sufficient.
		 * No details in rpc_createerr.cf_error needed.
		 */
		return (NULL);
	}

	parms.r_addr = NULL;

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

	/*
	 * 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;
			rpc_createerr.cf_error.re_terrno = 0;
			goto error;
		}
		check_rpcbind = FALSE;
	}

	/*
	 * First try version 4.
	 */
	parms.r_prog = program;
	parms.r_vers = version;
	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) {
		tmp_client = TRUE;
		if ((handle = __rpc_setconf("datagram_v")) != NULL) {
			struct netconfig *nconf_clts;

			while ((nconf_clts = __rpc_getconf(handle)) != NULL) {
				if (strcmp(nconf_clts->nc_protofmly,
				    nconf->nc_protofmly) != 0) {
					continue;
				}
				/*
				 * Sets rpc_createerr.cf_error members
				 * on failure
				 */
				client = _getclnthandle_timed(host, nconf_clts,
				    &parms.r_addr, tp);
				break;
			}
			__rpc_endconf(handle);
		}
	} else {
		/* Sets rpc_createerr.cf_error members on failure */
		client = _getclnthandle_timed(host, nconf, &parms.r_addr, tp);
	}

	if (client != NULL) {

		/* Set rpcbind version 4 */
		vers = RPCBVERS4;
		CLNT_CONTROL(client, CLSET_VERS, (char *)&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) {
			parms.r_addr = strdup(""); /* for XDRing */
			if (parms.r_addr == NULL) {
				syslog(LOG_ERR, "__rpcb_findaddr_timed: "
				    "strdup failed.");
				/* Construct a system error */
				rpc_createerr.cf_error.re_errno = errno;
				rpc_createerr.cf_error.re_terrno = 0;
				rpc_createerr.cf_stat = RPC_SYSTEMERROR;
				goto error;
			}
		}

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

		/* Sets error structure members in client handle */
		clnt_st = CLNT_CALL(client, RPCBPROC_GETADDRLIST,
		    (xdrproc_t)xdr_rpcb, (char *)&parms,
		    (xdrproc_t)xdr_rpcb_entry_list_ptr, (char *)&relp, *tp);

		switch (clnt_st) {
		case RPC_SUCCESS: /* Call succeeded */
			address = got_entry(relp, nconf);
			xdr_free((xdrproc_t)xdr_rpcb_entry_list_ptr,
			    (char *)&relp);
			if (address != NULL) {
				/* Program number and version number matched */
				goto done;
			}
			/* Program and version not found for this transport */
			/*
			 * XXX: should have returned with RPC_PROGUNAVAIL
			 * or perhaps RPC_PROGNOTREGISTERED error but
			 * since the remote machine might not always be able
			 * to send the address on all transports, we try the
			 * regular way with version 3, then 2
			 */
			/* Try the next version */
			break;
		case RPC_PROGVERSMISMATCH: /* RPC protocol mismatch */
			clnt_geterr(client, &rpc_createerr.cf_error);
			if (rpc_createerr.cf_error.re_vers.low > vers) {
				rpc_createerr.cf_stat = clnt_st;
				goto error;  /* a new version, can't handle */
			}
			/* Try the next version */
			break;
		case RPC_PROCUNAVAIL: /* Procedure unavailable */
		case RPC_PROGUNAVAIL: /* Program not available */
		case RPC_TIMEDOUT: /* Call timed out */
			/* Try the next version */
			break;
		default:
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = RPC_PMAPFAILURE;
			goto error;
			break;
		}

	} else {

		/* No client */
		tmp_client = FALSE;

	} /* End of version 4 */

	/* Destroy a temporary client */
	if (client != NULL && tmp_client) {
		CLNT_DESTROY(client);
		client = NULL;
		free(parms.r_addr);
		parms.r_addr = NULL;
	}
	tmp_client = FALSE;

	/*
	 * Try version 3
	 */

	/* Now the same transport is to be used to get the address */
	if (client == NULL) {
		/* Sets rpc_createerr.cf_error members on failure */
		client = _getclnthandle_timed(host, nconf, &parms.r_addr, tp);
	}
	address = NULL;
	if (client != NULL) {
		if (parms.r_addr == NULL) {
			parms.r_addr = strdup("");	/* for XDRing */
			if (parms.r_addr == NULL) {
				syslog(LOG_ERR, "__rpcb_findaddr_timed: "
				    "strdup failed.");
				/* Construct a system error */
				rpc_createerr.cf_error.re_errno = errno;
				rpc_createerr.cf_error.re_terrno = 0;
				rpc_createerr.cf_stat = RPC_SYSTEMERROR;
				goto error;
			}
		}

		CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT,
		    (char *)&rpcbrmttime);
		vers = RPCBVERS; /* Set the version */
		CLNT_CONTROL(client, CLSET_VERS, (char *)&vers);

		/* Sets error structure members in client handle */
		clnt_st = CLNT_CALL(client, RPCBPROC_GETADDR,
		    (xdrproc_t)xdr_rpcb, (char *)&parms,
		    (xdrproc_t)xdr_wrapstring, (char *)&ua, *tp);

		switch (clnt_st) {
		case RPC_SUCCESS: /* Call succeeded */
			if (ua != NULL) {
				if (ua[0] != '\0') {
					address = uaddr2taddr(nconf, ua);
				}
				xdr_free((xdrproc_t)xdr_wrapstring,
				    (char *)&ua);

				if (address != NULL) {
					goto done;
				}
				/* NULL universal address */
				/* But client call was successful */
				clnt_geterr(client, &rpc_createerr.cf_error);
				rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
				goto error;
			}
#ifndef PORTMAP
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
			goto error;
#endif
			/* Try the next version */
			break;
		case RPC_PROGVERSMISMATCH: /* RPC protocol mismatch */
			clnt_geterr(client, &rpc_createerr.cf_error);
#ifdef PORTMAP
			if (rpc_createerr.cf_error.re_vers.low > vers) {
				rpc_createerr.cf_stat = clnt_st;
				goto error;  /* a new version, can't handle */
			}
#else
			rpc_createerr.cf_stat = clnt_st;
			goto error;
#endif
			/* Try the next version */
			break;
#ifdef PORTMAP
		case RPC_PROCUNAVAIL: /* Procedure unavailable */
		case RPC_PROGUNAVAIL: /* Program not available */
		case RPC_TIMEDOUT: /* Call timed out */
			/* Try the next version */
			break;
#endif
		default:
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = RPC_PMAPFAILURE;
			goto error;
			break;
		}
	} /* End of version 3 */
#ifndef PORTMAP
	/* cf_error members set by creation failure */
	rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
#endif
	/*
	 * Try version 2
	 */

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

		/*
		 * 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 (client != NULL) {
				CLNT_DESTROY(client);
				client = NULL;
				free(parms.r_addr);
				parms.r_addr = NULL;
			}
			if ((handle = __rpc_setconf("udp")) == NULL) {
				/* Construct an unknown protocol error */
				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
				goto error;
			}

			/*
			 * The following to reinforce that you can
			 * only request for remote address through
			 * the same transport you are requesting.
			 * ie. requesting unversial address
			 * of IPv4 has to be carried through IPv4.
			 * Can't use IPv6 to send out the request.
			 * The mergeaddr in rpcbind can't handle
			 * this.
			 */
			for (;;) {
				if ((newnconf = __rpc_getconf(handle))
				    == NULL) {
					__rpc_endconf(handle);
					/*
					 * Construct an unknown protocol
					 * error
					 */
					rpc_createerr.cf_stat =
					    RPC_UNKNOWNPROTO;
					goto error;
				}
				/*
				 * here check the protocol family to
				 * be consistent with the request one
				 */
				if (strcmp(newnconf->nc_protofmly,
				    nconf->nc_protofmly) == 0)
					break;
			}

			/* Sets rpc_createerr.cf_error members on failure */
			client = _getclnthandle_timed(host, newnconf,
			    &parms.r_addr, tp);
			__rpc_endconf(handle);
			tmp_client = TRUE;
		}
		if (client == NULL) {
			/*
			 * rpc_createerr. cf_error members were set by
			 * creation failure
			 */
			rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
			tmp_client = FALSE;
			goto error;
		}

		/*
		 * 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) != 0) ?
		    IPPROTO_UDP : IPPROTO_TCP;
		pmapparms.pm_port = 0;	/* not needed */

		/* Sets error structure members in client handle */
		clnt_st = CLNT_CALL(client, PMAPPROC_GETPORT,
		    (xdrproc_t)xdr_pmap, (caddr_t)&pmapparms,
		    (xdrproc_t)xdr_u_short, (caddr_t)&port, *tp);

		if (clnt_st != RPC_SUCCESS) {
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = RPC_RPCBFAILURE;
			goto error;
		} else if (port == 0) {
			/* Will be NULL universal address */
			/* But client call was successful */
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
			goto error;
		}
		port = htons(port);
		CLNT_CONTROL(client, CLGET_SVC_ADDR, (char *)&remote);
		if (((address = malloc(sizeof (struct netbuf))) == NULL) ||
		    ((address->buf = malloc(remote.len)) == NULL)) {
			/* Construct a system error */
			rpc_createerr.cf_error.re_errno = errno;
			rpc_createerr.cf_error.re_terrno = 0;
			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
			free(address);
			address = NULL;
			goto error;
		}
		(void) memcpy(address->buf, remote.buf, remote.len);
		(void) memcpy(&address->buf[sizeof (short)], &port,
		    sizeof (short));
		address->len = address->maxlen = remote.len;
		goto done;
	} else {
		/*
		 * This is not NC_INET.
		 * Always an error for version 2.
		 */
		if (client != NULL && clnt_st != RPC_SUCCESS) {
			/* There is a client that failed */
			clnt_geterr(client, &rpc_createerr.cf_error);
			rpc_createerr.cf_stat = clnt_st;
		} else {
			/* Something else */
			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
			/*
			 * Setting rpc_createerr.cf_stat is sufficient.
			 * No details in rpc_createerr.cf_error needed.
			 */
		}
	}
#endif

error:
	/* Return NULL address and NULL client */
	address = NULL;
	if (client != NULL) {
		CLNT_DESTROY(client);
		client = NULL;
	}

done:
	/* Return an address and optional client */
	if (client != NULL && tmp_client) {
		/* This client is the temporary one */
		CLNT_DESTROY(client);
		client = NULL;
	}
	if (clpp != NULL) {
		*clpp = client;
	} else if (client != NULL) {
		CLNT_DESTROY(client);
	}
	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
 */
int
rpcb_getaddr(const rpcprog_t program, const 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, NULL, NULL)) == NULL)
		return (FALSE);

	if (na->len > address->maxlen) {
		/* Too long address */
		netdir_free((char *)na, ND_ADDR);
		rpc_createerr.cf_stat = RPC_FAILED;
		return (FALSE);
	}
	(void) memcpy(address->buf, na->buf, (int)na->len);
	address->len = na->len;
	netdir_free((char *)na, ND_ADDR);
	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;
	int vers = 0;

	client = getclnthandle((char *)host,
	    (struct netconfig *)nconf, NULL);
	if (client == NULL)
		return (NULL);

	clnt_st = CLNT_CALL(client, RPCBPROC_DUMP,
	    (xdrproc_t)xdr_void, NULL,
	    (xdrproc_t)xdr_rpcblist_ptr,
	    (char *)&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 *)&vers);
	if (vers == RPCBVERS4) {
		vers = RPCBVERS;
		CLNT_CONTROL(client, CLSET_VERS, (char *)&vers);
		if (CLNT_CALL(client, RPCBPROC_DUMP,
		    (xdrproc_t)xdr_void,
		    NULL, (xdrproc_t)xdr_rpcblist_ptr,
		    (char *)&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.
 */
enum clnt_stat
rpcb_rmtcall(const struct netconfig *nconf, const char *host,
	const rpcprog_t prog, const rpcvers_t vers, const rpcproc_t proc,
	const xdrproc_t xdrargs, const caddr_t argsp, const xdrproc_t xdrres,
	const caddr_t resp, const struct timeval tout, struct netbuf *addr_ptr)
{
	CLIENT *client;
	enum clnt_stat stat;
	struct r_rpcb_rmtcallargs a;
	struct r_rpcb_rmtcallres r;
	int rpcb_vers;

	client = getclnthandle((char *)host, (struct netconfig *)nconf, NULL);
	if (client == NULL)
		return (RPC_FAILED);
	CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)&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 *)&rpcb_vers);
		stat = CLNT_CALL(client, RPCBPROC_CALLIT,
		    (xdrproc_t)xdr_rpcb_rmtcallargs, (char *)&a,
		    (xdrproc_t)xdr_rpcb_rmtcallres, (char *)&r, tout);
		if ((stat == RPC_SUCCESS) && (addr_ptr != NULL)) {
			struct netbuf *na;

			na = uaddr2taddr((struct netconfig *)nconf, r.addr);
			if (!na) {
				stat = RPC_N2AXLATEFAILURE;
				((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 */
				netdir_free((char *)na, ND_ADDR);
				((struct netbuf *)addr_ptr)->len = 0;
				goto error;
			}
			(void) memcpy(addr_ptr->buf, na->buf, (int)na->len);
			((struct netbuf *)addr_ptr)->len = na->len;
			netdir_free((char *)na, ND_ADDR);
			break;
		}
		if ((stat != RPC_PROGVERSMISMATCH) &&
		    (stat != RPC_PROGUNAVAIL))
			goto error;
	}
error:
	CLNT_DESTROY(client);
	if (r.addr)
		xdr_free((xdrproc_t)xdr_wrapstring, (char *)&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;
	int vers;
	enum clnt_stat st;

	if ((host == NULL) || (host[0] == NULL)) {
		(void) 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((char *)host, nconf, NULL);
		if (client)
			break;
	}
	__rpc_endconf(handle);
	if (client == NULL)
		return (FALSE);

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

	if ((st == RPC_PROGVERSMISMATCH) || (st == RPC_PROGUNAVAIL)) {
		CLNT_CONTROL(client, CLGET_VERS, (char *)&vers);
		if (vers == RPCBVERS4) {
			/* fall back to earlier version */
			vers = RPCBVERS;
			CLNT_CONTROL(client, CLSET_VERS, (char *)&vers);
			st = CLNT_CALL(client, RPCBPROC_GETTIME,
			    (xdrproc_t)xdr_void, NULL,
			    (xdrproc_t)xdr_time_t, (char *)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, RPCBPROC_TADDR2UADDR, (xdrproc_t)xdr_netbuf,
	    (char *)taddr, (xdrproc_t)xdr_wrapstring, (char *)&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 = calloc(1, sizeof (struct netbuf));
	if (taddr == NULL) {
		CLNT_DESTROY(client);
		return (NULL);
	}

	if (CLNT_CALL(client, RPCBPROC_UADDR2TADDR, (xdrproc_t)xdr_wrapstring,
	    (char *)&uaddr, (xdrproc_t)xdr_netbuf, (char *)taddr,
	    tottimeout) != RPC_SUCCESS) {
		free(taddr);
		taddr = NULL;
	}
	CLNT_DESTROY(client);
	return (taddr);
}