/*      $NetBSD: lock_proc.c,v 1.10 2012/06/18 20:30:32 tron Exp $      */

/*
 * Copyright (c) 1995
 *      A.R. Gordon (andrew.gordon@net-tel.co.uk).  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the FreeBSD project
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON 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 AUTHOR 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.
 *
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: lock_proc.c,v 1.10 2012/06/18 20:30:32 tron Exp $");
#endif

#include <sys/param.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <netconfig.h>

#include <rpc/rpc.h>
#include <rpcsvc/sm_inter.h>

#include "lockd.h"
#include <rpcsvc/nlm_prot.h>
#include "lockd_lock.h"


#define CLIENT_CACHE_SIZE       64      /* No. of client sockets cached */
#define CLIENT_CACHE_LIFETIME   120     /* In seconds */

static void     log_from_addr(const char *, struct svc_req *);
static int      addrcmp(const struct sockaddr *, const struct sockaddr *);
static void     nlmtonlm4(struct nlm_lock *, struct nlm4_lock *);

/* log_from_addr ----------------------------------------------------------- */
/*
 * Purpose:     Log name of function called and source address
 * Returns:     Nothing
 * Notes:       Extracts the source address from the transport handle
 *              passed in as part of the called procedure specification
 */
static void
log_from_addr(const char *fun_name, struct svc_req *req)
{
        struct sockaddr *addr;
        char hostname_buf[NI_MAXHOST];

        addr = svc_getrpccaller(req->rq_xprt)->buf;
        if (getnameinfo(addr, (socklen_t)addr->sa_len, hostname_buf,
            sizeof(hostname_buf), NULL, 0, 0) != 0)
                return;

        syslog(LOG_DEBUG, "%s from %s", fun_name, hostname_buf);
}

/* get_client -------------------------------------------------------------- */
/*
 * Purpose:     Get a CLIENT* for making RPC calls to lockd on given host
 * Returns:     CLIENT* pointer, from clnt_udp_create, or NULL if error
 * Notes:       Creating a CLIENT* is quite expensive, involving a
 *              conversation with the remote portmapper to get the
 *              port number.  Since a given client is quite likely
 *              to make several locking requests in succession, it is
 *              desirable to cache the created CLIENT*.
 *
 *              Since we are using UDP rather than TCP, there is no cost
 *              to the remote system in keeping these cached indefinitely.
 *              Unfortunately there is a snag: if the remote system
 *              reboots, the cached portmapper results will be invalid,
 *              and we will never detect this since all of the xxx_msg()
 *              calls return no result - we just fire off a udp packet
 *              and hope for the best.
 *
 *              We solve this by discarding cached values after two
 *              minutes, regardless of whether they have been used
 *              in the meanwhile (since a bad one might have been used
 *              plenty of times, as the host keeps retrying the request
 *              and we keep sending the reply back to the wrong port).
 *
 *              Given that the entries will always expire in the order
 *              that they were created, there is no point in a LRU
 *              algorithm for when the cache gets full - entries are
 *              always re-used in sequence.
 */
static CLIENT *clnt_cache_ptr[CLIENT_CACHE_SIZE];
static long clnt_cache_time[CLIENT_CACHE_SIZE]; /* time entry created */
static struct sockaddr_storage clnt_cache_addr[CLIENT_CACHE_SIZE];
static int clnt_cache_next_to_use = 0;

static int
addrcmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
{
        size_t len;
        const void *p1, *p2;

        if (sa1->sa_family != sa2->sa_family)
                return -1;

        switch (sa1->sa_family) {
        case AF_INET:
                p1 = &((const struct sockaddr_in *)(const void *)sa1)->sin_addr;
                p2 = &((const struct sockaddr_in *)(const void *)sa2)->sin_addr;
                len = 4;
                break;
        case AF_INET6:
                p1 = &((const struct sockaddr_in6 *)(const void *)sa1)->sin6_addr;
                p2 = &((const struct sockaddr_in6 *)(const void *)sa2)->sin6_addr;
                len = 16;
                break;
        default:
                return -1;
        }

        return memcmp(p1, p2, len);
}

CLIENT *
get_client(struct sockaddr *host_addr, rpcvers_t vers)
{
        CLIENT *client;
        struct timeval retry_time, time_now;
        int i;
        const char *netid;
        struct netconfig *nconf;
        char host[NI_MAXHOST];
        int error;

        (void)gettimeofday(&time_now, NULL);

        /*
         * Search for the given client in the cache, zapping any expired
         * entries that we happen to notice in passing.
         */
        for (i = 0; i < CLIENT_CACHE_SIZE; i++) {
                client = clnt_cache_ptr[i];
                if (client && ((clnt_cache_time[i] + CLIENT_CACHE_LIFETIME)
                    < time_now.tv_sec)) {
                        /* Cache entry has expired. */
                        if (debug_level > 3)
                                syslog(LOG_DEBUG, "Expired CLIENT* in cache");
                        clnt_cache_time[i] = 0L;
                        clnt_destroy(client);
                        clnt_cache_ptr[i] = NULL;
                        client = NULL;
                }
                if (client && !addrcmp((const struct sockaddr *)(const void *)
                    &clnt_cache_addr[i], host_addr)) {
                        /* Found it! */
                        if (debug_level > 3)
                                syslog(LOG_DEBUG, "Found CLIENT* in cache");
                        return client;
                }
        }

        /* Not found in cache.  Free the next entry if it is in use. */
        if (clnt_cache_ptr[clnt_cache_next_to_use]) {
                clnt_destroy(clnt_cache_ptr[clnt_cache_next_to_use]);
                clnt_cache_ptr[clnt_cache_next_to_use] = NULL;
        }

        /*
         * Need a host string for clnt_tp_create. Use NI_NUMERICHOST
         * to avoid DNS lookups.
         */
        error = getnameinfo(host_addr, (socklen_t)host_addr->sa_len, host,
            sizeof(host), NULL, 0, NI_NUMERICHOST);
        if (error != 0) {
                syslog(LOG_ERR, "unable to get name string for caller: %s",
                    gai_strerror(error));
                return NULL;
        }

#if 1
        if (host_addr->sa_family == AF_INET6)
                netid = "udp6";
        else
                netid = "udp";
#else 
        if (host_addr->sa_family == AF_INET6)
                netid = "tcp6";
        else
                netid = "tcp";
#endif
        nconf = getnetconfigent(netid);
        if (nconf == NULL) {
                syslog(LOG_ERR, "could not get netconfig info for '%s': "
                                "no /etc/netconfig file?", netid);
                return NULL;
        }

        client = clnt_tp_create(host, NLM_PROG, vers, nconf);
        freenetconfigent(nconf);

        if (!client) {
                syslog(LOG_ERR, "%s", clnt_spcreateerror("clntudp_create"));
                syslog(LOG_ERR, "Unable to return result to %s", host);
                return NULL;
        }

        /* Success - update the cache entry */
        clnt_cache_ptr[clnt_cache_next_to_use] = client;
        (void)memcpy(&clnt_cache_addr[clnt_cache_next_to_use], host_addr,
            (size_t)host_addr->sa_len);
        clnt_cache_time[clnt_cache_next_to_use] = time_now.tv_sec;
        if (++clnt_cache_next_to_use >= CLIENT_CACHE_SIZE)
                clnt_cache_next_to_use = 0;

        /*
         * Disable the default timeout, so we can specify our own in calls
         * to clnt_call().  (Note that the timeout is a different concept
         * from the retry period set in clnt_udp_create() above.)
         */
        retry_time.tv_sec = -1;
        retry_time.tv_usec = -1;
        clnt_control(client, CLSET_TIMEOUT, (char *)(void *)&retry_time);

        if (debug_level > 3)
                syslog(LOG_DEBUG, "Created CLIENT* for %s", host);
        return client;
}


/* transmit_result --------------------------------------------------------- */
/*
 * Purpose:     Transmit result for nlm_xxx_msg pseudo-RPCs
 * Returns:     Nothing - we have no idea if the datagram got there
 * Notes:       clnt_call() will always fail (with timeout) as we are
 *              calling it with timeout 0 as a hack to just issue a datagram
 *              without expecting a result
 */
void
transmit_result(int opcode, nlm_res *result, struct sockaddr *addr)
{
        static char dummy;
        CLIENT *cli;
        struct timeval timeo;
        int success;

        if ((cli = get_client(addr, NLM_VERS)) != NULL) {
                timeo.tv_sec = 0; /* No timeout - not expecting response */
                timeo.tv_usec = 0;

                success = clnt_call(cli, (rpcproc_t)opcode, xdr_nlm_res,
                    result, xdr_void, &dummy, timeo);

                if (debug_level > 2)
                        syslog(LOG_DEBUG, "clnt_call returns %d(%s)",
                            success, clnt_sperrno(success));
        }
}
/* transmit4_result --------------------------------------------------------- */
/*
 * Purpose:     Transmit result for nlm4_xxx_msg pseudo-RPCs
 * Returns:     Nothing - we have no idea if the datagram got there
 * Notes:       clnt_call() will always fail (with timeout) as we are
 *              calling it with timeout 0 as a hack to just issue a datagram
 *              without expecting a result
 */
void
transmit4_result(int opcode, nlm4_res *result, struct sockaddr *addr)
{
        static char dummy;
        CLIENT *cli;
        struct timeval timeo;
        int success;

        if ((cli = get_client(addr, NLM_VERS4)) != NULL) {
                timeo.tv_sec = 0; /* No timeout - not expecting response */
                timeo.tv_usec = 0;

                success = clnt_call(cli, (rpcproc_t)opcode, xdr_nlm4_res,
                    result, xdr_void, &dummy, timeo);

                if (debug_level > 2)
                        syslog(LOG_DEBUG, "clnt_call returns %d(%s)",
                            success, clnt_sperrno(success));
        }
}

/*
 * converts a struct nlm_lock to struct nlm4_lock
 */
static void
nlmtonlm4(struct nlm_lock *arg, struct nlm4_lock *arg4)
{
        (void)memcpy(arg4, arg, sizeof(nlm_lock));
        arg4->l_offset = arg->l_offset;
        arg4->l_len = arg->l_len;
}

/* ------------------------------------------------------------------------- */
/*
 * Functions for Unix<->Unix locking (ie. monitored locking, with rpc.statd
 * involved to ensure reclaim of locks after a crash of the "stateless"
 * server.
 *
 * These all come in two flavours - nlm_xxx() and nlm_xxx_msg().
 * The first are standard RPCs with argument and result.
 * The nlm_xxx_msg() calls implement exactly the same functions, but
 * use two pseudo-RPCs (one in each direction).  These calls are NOT
 * standard use of the RPC protocol in that they do not return a result
 * at all (NB. this is quite different from returning a void result).
 * The effect of this is to make the nlm_xxx_msg() calls simple unacknowledged
 * datagrams, requiring higher-level code to perform retries.
 *
 * Despite the disadvantages of the nlm_xxx_msg() approach (some of which
 * are documented in the comments to get_client() above), this is the
 * interface used by all current commercial NFS implementations
 * [Solaris, SCO, AIX etc.].  This is presumed to be because these allow
 * implementations to continue using the standard RPC libraries, while
 * avoiding the block-until-result nature of the library interface.
 *
 * No client implementations have been identified so far that make use
 * of the true RPC version (early SunOS releases would be a likely candidate
 * for testing).
 */

/* nlm_test ---------------------------------------------------------------- */
/*
 * Purpose:     Test whether a specified lock would be granted if requested
 * Returns:     nlm_granted (or error code)
 * Notes:
 */
nlm_testres *
nlm_test_1_svc(nlm_testargs *arg, struct svc_req *rqstp)
{
        static nlm_testres result;
        struct nlm4_lock arg4;
        struct nlm4_holder *holder;
        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_test", rqstp);

        holder = testlock(&arg4, 0);
        /*
         * Copy the cookie from the argument into the result.  Note that this
         * is slightly hazardous, as the structure contains a pointer to a
         * malloc()ed buffer that will get freed by the caller.  However, the
         * main function transmits the result before freeing the argument
         * so it is in fact safe.
         */
        result.cookie = arg->cookie;
        if (holder == NULL) {
                result.stat.stat = nlm_granted;
        } else {
                result.stat.stat = nlm_denied;
                (void)memcpy(&result.stat.nlm_testrply_u.holder, holder,
                    sizeof(struct nlm_holder));
                result.stat.nlm_testrply_u.holder.l_offset =
                    (unsigned int)holder->l_offset;
                result.stat.nlm_testrply_u.holder.l_len =
                    (unsigned int)holder->l_len;
        }
        return &result;
}

void *
nlm_test_msg_1_svc(nlm_testargs *arg, struct svc_req *rqstp)
{
        nlm_testres result;
        static char dummy;
        struct sockaddr *addr;
        CLIENT *cli;
        int success;
        struct timeval timeo;
        struct nlm4_lock arg4;
        struct nlm4_holder *holder;

        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_test_msg", rqstp);

        holder = testlock(&arg4, 0);

        result.cookie = arg->cookie;
        if (holder == NULL) {
                result.stat.stat = nlm_granted;
        } else {
                result.stat.stat = nlm_denied;
                (void)memcpy(&result.stat.nlm_testrply_u.holder, holder,
                    sizeof(struct nlm_holder));
                result.stat.nlm_testrply_u.holder.l_offset =
                    (unsigned int)holder->l_offset;
                result.stat.nlm_testrply_u.holder.l_len =
                    (unsigned int)holder->l_len;
        }

        /*
         * nlm_test has different result type to the other operations, so
         * can't use transmit_result() in this case
         */
        addr = svc_getrpccaller(rqstp->rq_xprt)->buf;
        if ((cli = get_client(addr, NLM_VERS)) != NULL) {
                timeo.tv_sec = 0; /* No timeout - not expecting response */
                timeo.tv_usec = 0;

                success = clnt_call(cli, NLM_TEST_RES, xdr_nlm_testres,
                    &result, xdr_void, &dummy, timeo);

                if (debug_level > 2)
                        syslog(LOG_DEBUG, "clnt_call returns %d", success);
        }
        return NULL;
}

/* nlm_lock ---------------------------------------------------------------- */
/*
 * Purposes:    Establish a lock
 * Returns:     granted, denied or blocked
 * Notes:       *** grace period support missing
 */
nlm_res *
nlm_lock_1_svc(nlm_lockargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lockargs arg4;
        nlmtonlm4(&arg->alock, &arg4.alock);
        arg4.cookie = arg->cookie;
        arg4.block = arg->block;
        arg4.exclusive = arg->exclusive;
        arg4.reclaim = arg->reclaim;
        arg4.state = arg->state;

        if (debug_level)
                log_from_addr("nlm_lock", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;

        result.stat.stat = getlock(&arg4, rqstp, LOCK_MON);
        return &result;
}

void *
nlm_lock_msg_1_svc(nlm_lockargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lockargs arg4;

        nlmtonlm4(&arg->alock, &arg4.alock);
        arg4.cookie = arg->cookie;
        arg4.block = arg->block;
        arg4.exclusive = arg->exclusive;
        arg4.reclaim = arg->reclaim;
        arg4.state = arg->state;

        if (debug_level)
                log_from_addr("nlm_lock_msg", rqstp);

        result.cookie = arg->cookie;
        result.stat.stat = getlock(&arg4, rqstp, LOCK_ASYNC | LOCK_MON);
        transmit_result(NLM_LOCK_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);

        return NULL;
}

/* nlm_cancel -------------------------------------------------------------- */
/*
 * Purpose:     Cancel a blocked lock request
 * Returns:     granted or denied
 * Notes:
 */
nlm_res *
nlm_cancel_1_svc(nlm_cancargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lock arg4;

        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_cancel", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;

        /*
         * Since at present we never return 'nlm_blocked', there can never be
         * a lock to cancel, so this call always fails.
         */
        result.stat.stat = unlock(&arg4, LOCK_CANCEL);
        return &result;
}

void *
nlm_cancel_msg_1_svc(nlm_cancargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lock arg4;

        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_cancel_msg", rqstp);

        result.cookie = arg->cookie;
        /*
         * Since at present we never return 'nlm_blocked', there can never be
         * a lock to cancel, so this call always fails.
         */
        result.stat.stat = unlock(&arg4, LOCK_CANCEL);
        transmit_result(NLM_CANCEL_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* nlm_unlock -------------------------------------------------------------- */
/*
 * Purpose:     Release an existing lock
 * Returns:     Always granted, unless during grace period
 * Notes:       "no such lock" error condition is ignored, as the
 *              protocol uses unreliable UDP datagrams, and may well
 *              re-try an unlock that has already succeeded.
 */
nlm_res *
nlm_unlock_1_svc(nlm_unlockargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lock arg4;

        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_unlock", rqstp);

        result.stat.stat = unlock(&arg4, 0);
        result.cookie = arg->cookie;

        return &result;
}

void *
nlm_unlock_msg_1_svc(nlm_unlockargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;
        struct nlm4_lock arg4;

        nlmtonlm4(&arg->alock, &arg4);

        if (debug_level)
                log_from_addr("nlm_unlock_msg", rqstp);

        result.stat.stat = unlock(&arg4, 0);
        result.cookie = arg->cookie;

        transmit_result(NLM_UNLOCK_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* ------------------------------------------------------------------------- */
/*
 * Client-side pseudo-RPCs for results.  Note that for the client there
 * are only nlm_xxx_msg() versions of each call, since the 'real RPC'
 * version returns the results in the RPC result, and so the client
 * does not normally receive incoming RPCs.
 *
 * The exception to this is nlm_granted(), which is genuinely an RPC
 * call from the server to the client - a 'call-back' in normal procedure
 * call terms.
 */

/* nlm_granted ------------------------------------------------------------- */
/*
 * Purpose:     Receive notification that formerly blocked lock now granted
 * Returns:     always success ('granted')
 * Notes:
 */
nlm_res *
nlm_granted_1_svc(nlm_testargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;

        if (debug_level)
                log_from_addr("nlm_granted", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;

        result.stat.stat = nlm_granted;
        return &result;
}

void *
nlm_granted_msg_1_svc(nlm_testargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;

        if (debug_level)
                log_from_addr("nlm_granted_msg", rqstp);

        result.cookie = arg->cookie;
        result.stat.stat = nlm_granted;
        transmit_result(NLM_GRANTED_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* nlm_test_res ------------------------------------------------------------ */
/*
 * Purpose:     Accept result from earlier nlm_test_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_test_res_1_svc(nlm_testres *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm_test_res", rqstp);
        return NULL;
}

/* nlm_lock_res ------------------------------------------------------------ */
/*
 * Purpose:     Accept result from earlier nlm_lock_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_lock_res_1_svc(nlm_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm_lock_res", rqstp);

        return NULL;
}

/* nlm_cancel_res ---------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_cancel_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_cancel_res_1_svc(nlm_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm_cancel_res", rqstp);
        return NULL;
}

/* nlm_unlock_res ---------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_unlock_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_unlock_res_1_svc(nlm_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm_unlock_res", rqstp);
        return NULL;
}

/* nlm_granted_res --------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_granted_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_granted_res_1_svc(nlm_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm_granted_res", rqstp);
        return NULL;
}

/* ------------------------------------------------------------------------- */
/*
 * Calls for PCNFS locking (aka non-monitored locking, no involvement
 * of rpc.statd).
 *
 * These are all genuine RPCs - no nlm_xxx_msg() nonsense here.
 */

/* nlm_share --------------------------------------------------------------- */
/*
 * Purpose:     Establish a DOS-style lock
 * Returns:     success or failure
 * Notes:       Blocking locks are not supported - client is expected
 *              to retry if required.
 */
nlm_shareres *
nlm_share_3_svc(nlm_shareargs *arg, struct svc_req *rqstp)
{
        static nlm_shareres result;

        if (debug_level)
                log_from_addr("nlm_share", rqstp);

        result.cookie = arg->cookie;
        result.stat = nlm_granted;
        result.sequence = 1234356;      /* X/Open says this field is ignored? */
        return &result;
}

/* nlm_unshare ------------------------------------------------------------ */
/*
 * Purpose:     Release a DOS-style lock
 * Returns:     nlm_granted, unless in grace period
 * Notes:
 */
nlm_shareres *
nlm_unshare_3_svc(nlm_shareargs *arg, struct svc_req *rqstp)
{
        static nlm_shareres result;

        if (debug_level)
                log_from_addr("nlm_unshare", rqstp);

        result.cookie = arg->cookie;
        result.stat = nlm_granted;
        result.sequence = 1234356;      /* X/Open says this field is ignored? */
        return &result;
}

/* nlm_nm_lock ------------------------------------------------------------ */
/*
 * Purpose:     non-monitored version of nlm_lock()
 * Returns:     as for nlm_lock()
 * Notes:       These locks are in the same style as the standard nlm_lock,
 *              but the rpc.statd should not be called to establish a
 *              monitor for the client machine, since that machine is
 *              declared not to be running a rpc.statd, and so would not
 *              respond to the statd protocol.
 */
nlm_res *
nlm_nm_lock_3_svc(nlm_lockargs *arg, struct svc_req *rqstp)
{
        static nlm_res result;

        if (debug_level)
                log_from_addr("nlm_nm_lock", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;
        result.stat.stat = nlm_granted;
        return &result;
}

/* nlm_free_all ------------------------------------------------------------ */
/*
 * Purpose:     Release all locks held by a named client
 * Returns:     Nothing
 * Notes:       Potential denial of service security problem here - the
 *              locks to be released are specified by a host name, independent
 *              of the address from which the request has arrived.
 *              Should probably be rejected if the named host has been
 *              using monitored locks.
 */
void *
/*ARGSUSED*/
nlm_free_all_3_svc(nlm_notify *arg, struct svc_req *rqstp)
{
        static char dummy;

        if (debug_level)
                log_from_addr("nlm_free_all", rqstp);
        return &dummy;
}

/* calls for nlm version 4 (NFSv3) */
/* nlm_test ---------------------------------------------------------------- */
/*
 * Purpose:     Test whether a specified lock would be granted if requested
 * Returns:     nlm_granted (or error code)
 * Notes:
 */
nlm4_testres *
nlm4_test_4_svc(nlm4_testargs *arg, struct svc_req *rqstp)
{
        static nlm4_testres result;
        struct nlm4_holder *holder;

        if (debug_level)
                log_from_addr("nlm4_test", rqstp);

        holder = testlock(&arg->alock, LOCK_V4);

        /*
         * Copy the cookie from the argument into the result.  Note that this
         * is slightly hazardous, as the structure contains a pointer to a
         * malloc()ed buffer that will get freed by the caller.  However, the
         * main function transmits the result before freeing the argument
         * so it is in fact safe.
         */
        result.cookie = arg->cookie;
        if (holder == NULL) {
                result.stat.stat = nlm4_granted;
        } else {
                result.stat.stat = nlm4_denied;
                (void)memcpy(&result.stat.nlm4_testrply_u.holder, holder,
                    sizeof(struct nlm4_holder));
        }
        return &result;
}

void *
nlm4_test_msg_4_svc(nlm4_testargs *arg, struct svc_req *rqstp)
{
        nlm4_testres result;
        static char dummy;
        struct sockaddr *addr;
        CLIENT *cli;
        int success;
        struct timeval timeo;
        struct nlm4_holder *holder;

        if (debug_level)
                log_from_addr("nlm4_test_msg", rqstp);

        holder = testlock(&arg->alock, LOCK_V4);

        result.cookie = arg->cookie;
        if (holder == NULL) {
                result.stat.stat = nlm4_granted;
        } else {
                result.stat.stat = nlm4_denied;
                (void)memcpy(&result.stat.nlm4_testrply_u.holder, holder,
                    sizeof(struct nlm4_holder));
        }

        /*
         * nlm_test has different result type to the other operations, so
         * can't use transmit4_result() in this case
         */
        addr = svc_getrpccaller(rqstp->rq_xprt)->buf;
        if ((cli = get_client(addr, NLM_VERS4)) != NULL) {
                timeo.tv_sec = 0; /* No timeout - not expecting response */
                timeo.tv_usec = 0;

                success = clnt_call(cli, NLM4_TEST_RES, xdr_nlm4_testres,
                    &result, xdr_void, &dummy, timeo);

                if (debug_level > 2)
                        syslog(LOG_DEBUG, "clnt_call returns %d", success);
        }
        return NULL;
}

/* nlm_lock ---------------------------------------------------------------- */
/*
 * Purposes:    Establish a lock
 * Returns:     granted, denied or blocked
 * Notes:       *** grace period support missing
 */
nlm4_res *
nlm4_lock_4_svc(nlm4_lockargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_lock", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_4() */
        result.cookie = arg->cookie;

        result.stat.stat = (enum nlm4_stats)getlock(arg, rqstp,
            LOCK_MON | LOCK_V4);
        return &result;
}

void *
nlm4_lock_msg_4_svc(nlm4_lockargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_lock_msg", rqstp);

        result.cookie = arg->cookie;
        result.stat.stat = (enum nlm4_stats)getlock(arg, rqstp,
            LOCK_MON | LOCK_ASYNC | LOCK_V4);
        transmit4_result(NLM4_LOCK_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);

        return NULL;
}

/* nlm_cancel -------------------------------------------------------------- */
/*
 * Purpose:     Cancel a blocked lock request
 * Returns:     granted or denied
 * Notes:
 */
nlm4_res *
nlm4_cancel_4_svc(nlm4_cancargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_cancel", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;

        /*
         * Since at present we never return 'nlm_blocked', there can never be
         * a lock to cancel, so this call always fails.
         */
        result.stat.stat = (enum nlm4_stats)unlock(&arg->alock, LOCK_CANCEL);
        return &result;
}

void *
nlm4_cancel_msg_4_svc(nlm4_cancargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_cancel_msg", rqstp);

        result.cookie = arg->cookie;
        /*
         * Since at present we never return 'nlm_blocked', there can never be
         * a lock to cancel, so this call always fails.
         */
        result.stat.stat = (enum nlm4_stats)unlock(&arg->alock,
            LOCK_CANCEL | LOCK_V4);
        transmit4_result(NLM4_CANCEL_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* nlm_unlock -------------------------------------------------------------- */
/*
 * Purpose:     Release an existing lock
 * Returns:     Always granted, unless during grace period
 * Notes:       "no such lock" error condition is ignored, as the
 *              protocol uses unreliable UDP datagrams, and may well
 *              re-try an unlock that has already succeeded.
 */
nlm4_res *
nlm4_unlock_4_svc(nlm4_unlockargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_unlock", rqstp);

        result.stat.stat = (enum nlm4_stats)unlock(&arg->alock, LOCK_V4);
        result.cookie = arg->cookie;

        return &result;
}

void *
nlm4_unlock_msg_4_svc(nlm4_unlockargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_unlock_msg", rqstp);

        result.stat.stat = (enum nlm4_stats)unlock(&arg->alock, LOCK_V4);
        result.cookie = arg->cookie;

        transmit4_result(NLM4_UNLOCK_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* ------------------------------------------------------------------------- */
/*
 * Client-side pseudo-RPCs for results.  Note that for the client there
 * are only nlm_xxx_msg() versions of each call, since the 'real RPC'
 * version returns the results in the RPC result, and so the client
 * does not normally receive incoming RPCs.
 *
 * The exception to this is nlm_granted(), which is genuinely an RPC
 * call from the server to the client - a 'call-back' in normal procedure
 * call terms.
 */

/* nlm_granted ------------------------------------------------------------- */
/*
 * Purpose:     Receive notification that formerly blocked lock now granted
 * Returns:     always success ('granted')
 * Notes:
 */
nlm4_res *
nlm4_granted_4_svc(nlm4_testargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_granted", rqstp);

        /* copy cookie from arg to result.  See comment in nlm_test_1() */
        result.cookie = arg->cookie;

        result.stat.stat = nlm4_granted;
        return &result;
}

void *
nlm4_granted_msg_4_svc(nlm4_testargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_granted_msg", rqstp);

        result.cookie = arg->cookie;
        result.stat.stat = nlm4_granted;
        transmit4_result(NLM4_GRANTED_RES, &result,
            (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf);
        return NULL;
}

/* nlm_test_res ------------------------------------------------------------ */
/*
 * Purpose:     Accept result from earlier nlm_test_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm4_test_res_4_svc(nlm4_testres *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm4_test_res", rqstp);
        return NULL;
}

/* nlm_lock_res ------------------------------------------------------------ */
/*
 * Purpose:     Accept result from earlier nlm_lock_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm4_lock_res_4_svc(nlm4_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm4_lock_res", rqstp);

        return NULL;
}

/* nlm_cancel_res ---------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_cancel_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm4_cancel_res_4_svc(nlm4_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm4_cancel_res", rqstp);
        return NULL;
}

/* nlm_unlock_res ---------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_unlock_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm4_unlock_res_4_svc(nlm4_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm4_unlock_res", rqstp);
        return NULL;
}

/* nlm_granted_res --------------------------------------------------------- */
/*
 * Purpose:     Accept result from earlier nlm_granted_msg() call
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm4_granted_res_4_svc(nlm4_res *arg, struct svc_req *rqstp)
{
        if (debug_level)
                log_from_addr("nlm4_granted_res", rqstp);
        return NULL;
}

/* ------------------------------------------------------------------------- */
/*
 * Calls for PCNFS locking (aka non-monitored locking, no involvement
 * of rpc.statd).
 *
 * These are all genuine RPCs - no nlm_xxx_msg() nonsense here.
 */

/* nlm_share --------------------------------------------------------------- */
/*
 * Purpose:     Establish a DOS-style lock
 * Returns:     success or failure
 * Notes:       Blocking locks are not supported - client is expected
 *              to retry if required.
 */
nlm4_shareres *
nlm4_share_4_svc(nlm4_shareargs *arg, struct svc_req *rqstp)
{
        static nlm4_shareres result;

        if (debug_level)
                log_from_addr("nlm4_share", rqstp);

        result.cookie = arg->cookie;
        result.stat = nlm4_granted;
        result.sequence = 1234356;      /* X/Open says this field is ignored? */
        return &result;
}

/* nlm4_unshare ------------------------------------------------------------ */
/*
 * Purpose:     Release a DOS-style lock
 * Returns:     nlm_granted, unless in grace period
 * Notes:
 */
nlm4_shareres *
nlm4_unshare_4_svc(nlm4_shareargs *arg, struct svc_req *rqstp)
{
        static nlm4_shareres result;

        if (debug_level)
                log_from_addr("nlm_unshare", rqstp);

        result.cookie = arg->cookie;
        result.stat = nlm4_granted;
        result.sequence = 1234356;      /* X/Open says this field is ignored? */
        return &result;
}

/* nlm4_nm_lock ------------------------------------------------------------ */
/*
 * Purpose:     non-monitored version of nlm4_lock()
 * Returns:     as for nlm4_lock()
 * Notes:       These locks are in the same style as the standard nlm4_lock,
 *              but the rpc.statd should not be called to establish a
 *              monitor for the client machine, since that machine is
 *              declared not to be running a rpc.statd, and so would not
 *              respond to the statd protocol.
 */
nlm4_res *
nlm4_nm_lock_4_svc(nlm4_lockargs *arg, struct svc_req *rqstp)
{
        static nlm4_res result;

        if (debug_level)
                log_from_addr("nlm4_nm_lock", rqstp);

        /* copy cookie from arg to result.  See comment in nlm4_test_1() */
        result.cookie = arg->cookie;
        result.stat.stat = nlm4_granted;
        return &result;
}

/* nlm4_free_all ------------------------------------------------------------ */
/*
 * Purpose:     Release all locks held by a named client
 * Returns:     Nothing
 * Notes:       Potential denial of service security problem here - the
 *              locks to be released are specified by a host name, independent
 *              of the address from which the request has arrived.
 *              Should probably be rejected if the named host has been
 *              using monitored locks.
 */
void *
/*ARGSUSED*/
nlm4_free_all_4_svc(nlm_notify *arg, struct svc_req *rqstp)
{
        static char dummy;

        if (debug_level)
                log_from_addr("nlm4_free_all", rqstp);
        return &dummy;
}

/* nlm_sm_notify --------------------------------------------------------- */
/*
 * Purpose:     called by rpc.statd when a monitored host state changes.
 * Returns:     Nothing
 */
void *
/*ARGSUSED*/
nlm_sm_notify_0_svc(struct nlm_sm_status *arg, struct svc_req *rqstp)
{
        static char dummy;
        notify(arg->mon_name, arg->state);
        return &dummy;
}