/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
 * Authors: Doug Rabson <dfr@rabson.org>
 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 "opt_inet6.h"

#include <sys/param.h>
#include <sys/fail.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/jail.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/syslog.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/taskqueue.h>
#include <sys/unistd.h>
#include <sys/vnode.h>

#include <nfs/nfsproto.h>
#include <nfs/nfs_lock.h>

#include <nlm/nlm_prot.h>
#include <nlm/sm_inter.h>
#include <nlm/nlm.h>
#include <rpc/rpc_com.h>
#include <rpc/rpcb_prot.h>

MALLOC_DEFINE(M_NLM, "NLM", "Network Lock Manager");

/*
 * If a host is inactive (and holds no locks) for this amount of
 * seconds, we consider it idle and stop tracking it.
 */
#define NLM_IDLE_TIMEOUT        30

/*
 * We check the host list for idle every few seconds.
 */
#define NLM_IDLE_PERIOD         5

/*
 * We only look for GRANTED_RES messages for a little while.
 */
#define NLM_EXPIRE_TIMEOUT      10

/*
 * Support for sysctl vfs.nlm.sysid
 */
static SYSCTL_NODE(_vfs, OID_AUTO, nlm, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
    "Network Lock Manager");
static SYSCTL_NODE(_vfs_nlm, OID_AUTO, sysid,
    CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
    "");

/*
 * Syscall hooks
 */
static struct syscall_helper_data nlm_syscalls[] = {
        SYSCALL_INIT_HELPER(nlm_syscall),
        SYSCALL_INIT_LAST
};

/*
 * Debug level passed in from userland. We also support a sysctl hook
 * so that it can be changed on a live system.
 */
static int nlm_debug_level;
SYSCTL_INT(_debug, OID_AUTO, nlm_debug, CTLFLAG_RW, &nlm_debug_level, 0, "");

#define NLM_DEBUG(_level, args...)                      \
        do {                                            \
                if (nlm_debug_level >= (_level))        \
                        log(LOG_DEBUG, args);           \
        } while(0)
#define NLM_ERR(args...)                        \
        do {                                    \
                log(LOG_ERR, args);             \
        } while(0)

/*
 * Grace period handling. The value of nlm_grace_threshold is the
 * value of time_uptime after which we are serving requests normally.
 */
static time_t nlm_grace_threshold;

/*
 * We check for idle hosts if time_uptime is greater than
 * nlm_next_idle_check,
 */
static time_t nlm_next_idle_check;

/*
 * A flag to indicate the server is already running.
 */
static int nlm_is_running;

/*
 * A socket to use for RPC - shared by all IPv4 RPC clients.
 */
static struct socket *nlm_socket;

#ifdef INET6

/*
 * A socket to use for RPC - shared by all IPv6 RPC clients.
 */
static struct socket *nlm_socket6;

#endif

/*
 * An RPC client handle that can be used to communicate with the local
 * NSM.
 */
static CLIENT *nlm_nsm;

/*
 * An AUTH handle for the server's creds.
 */
static AUTH *nlm_auth;

/*
 * A zero timeval for sending async RPC messages.
 */
struct timeval nlm_zero_tv = { 0, 0 };

/*
 * The local NSM state number
 */
int nlm_nsm_state;

/*
 * A lock to protect the host list and waiting lock list.
 */
static struct mtx nlm_global_lock;

/*
 * Locks:
 * (l)          locked by nh_lock
 * (s)          only accessed via server RPC which is single threaded
 * (g)          locked by nlm_global_lock
 * (c)          const until freeing
 * (a)          modified using atomic ops
 */

/*
 * A pending client-side lock request, stored on the nlm_waiting_locks
 * list.
 */
struct nlm_waiting_lock {
        TAILQ_ENTRY(nlm_waiting_lock) nw_link; /* (g) */
        bool_t          nw_waiting;            /* (g) */
        nlm4_lock       nw_lock;               /* (c) */
        union nfsfh     nw_fh;                 /* (c) */
        struct vnode    *nw_vp;                /* (c) */
};
TAILQ_HEAD(nlm_waiting_lock_list, nlm_waiting_lock);

struct nlm_waiting_lock_list nlm_waiting_locks; /* (g) */

/*
 * A pending server-side asynchronous lock request, stored on the
 * nh_pending list of the NLM host.
 */
struct nlm_async_lock {
        TAILQ_ENTRY(nlm_async_lock) af_link; /* (l) host's list of locks */
        struct task     af_task;        /* (c) async callback details */
        void            *af_cookie;     /* (l) lock manager cancel token */
        struct vnode    *af_vp;         /* (l) vnode to lock */
        struct flock    af_fl;          /* (c) lock details */
        struct nlm_host *af_host;       /* (c) host which is locking */
        CLIENT          *af_rpc;        /* (c) rpc client to send message */
        nlm4_testargs   af_granted;     /* (c) notification details */
        time_t          af_expiretime;  /* (c) notification time */
};
TAILQ_HEAD(nlm_async_lock_list, nlm_async_lock);

/*
 * NLM host.
 */
enum nlm_host_state {
        NLM_UNMONITORED,
        NLM_MONITORED,
        NLM_MONITOR_FAILED,
        NLM_RECOVERING
};

struct nlm_rpc {
        CLIENT          *nr_client;    /* (l) RPC client handle */
        time_t          nr_create_time; /* (l) when client was created */
};

struct nlm_host {
        struct mtx      nh_lock;
        volatile u_int  nh_refs;       /* (a) reference count */
        TAILQ_ENTRY(nlm_host) nh_link; /* (g) global list of hosts */
        char            nh_caller_name[MAXNAMELEN]; /* (c) printable name of host */
        uint32_t        nh_sysid;        /* (c) our allocaed system ID */
        char            nh_sysid_string[10]; /* (c) string rep. of sysid */
        struct sockaddr_storage nh_addr; /* (s) remote address of host */
        struct nlm_rpc  nh_srvrpc;       /* (l) RPC for server replies */
        struct nlm_rpc  nh_clntrpc;      /* (l) RPC for client requests */
        rpcvers_t       nh_vers;         /* (s) NLM version of host */
        int             nh_state;        /* (s) last seen NSM state of host */
        enum nlm_host_state nh_monstate; /* (l) local NSM monitoring state */
        time_t          nh_idle_timeout; /* (s) Time at which host is idle */
        struct sysctl_ctx_list nh_sysctl; /* (c) vfs.nlm.sysid nodes */
        uint32_t        nh_grantcookie;  /* (l) grant cookie counter */
        struct nlm_async_lock_list nh_pending; /* (l) pending async locks */
        struct nlm_async_lock_list nh_granted; /* (l) granted locks */
        struct nlm_async_lock_list nh_finished; /* (l) finished async locks */
};
TAILQ_HEAD(nlm_host_list, nlm_host);

static struct nlm_host_list nlm_hosts; /* (g) */
static uint32_t nlm_next_sysid = 1;    /* (g) */

static void     nlm_host_unmonitor(struct nlm_host *);

struct nlm_grantcookie {
        uint32_t        ng_sysid;
        uint32_t        ng_cookie;
};

static inline uint32_t
ng_sysid(struct netobj *src)
{

        return ((struct nlm_grantcookie *)src->n_bytes)->ng_sysid;
}

static inline uint32_t
ng_cookie(struct netobj *src)
{

        return ((struct nlm_grantcookie *)src->n_bytes)->ng_cookie;
}

/**********************************************************************/

/*
 * Initialise NLM globals.
 */
static int
nlm_init(void)
{
        int error;

        mtx_init(&nlm_global_lock, "nlm_global_lock", NULL, MTX_DEF);
        TAILQ_INIT(&nlm_waiting_locks);
        TAILQ_INIT(&nlm_hosts);

        error = syscall_helper_register(nlm_syscalls, SY_THR_STATIC_KLD);
        if (error != 0)
                NLM_ERR("Can't register NLM syscall\n");
        return (error);
}

static void
nlm_uninit(void)
{

        syscall_helper_unregister(nlm_syscalls);
}

/*
 * Create a netobj from an arbitrary source.
 */
void
nlm_make_netobj(struct netobj *dst, caddr_t src, size_t srcsize,
    struct malloc_type *type)
{

        dst->n_len = srcsize;
        dst->n_bytes = malloc(srcsize, type, M_WAITOK);
        memcpy(dst->n_bytes, src, srcsize);
}

/*
 * Copy a struct netobj.
 */ 
void
nlm_copy_netobj(struct netobj *dst, struct netobj *src,
    struct malloc_type *type)
{

        nlm_make_netobj(dst, src->n_bytes, src->n_len, type);
}

/*
 * Create an RPC client handle for the given (address,prog,vers)
 * triple using UDP.
 */
static CLIENT *
nlm_get_rpc(struct sockaddr *sa, rpcprog_t prog, rpcvers_t vers)
{
        char *wchan = "nlmrcv";
        struct sockaddr_storage ss;
        struct socket *so;
        CLIENT *rpcb;
        struct timeval timo;
        RPCB parms;
        char *uaddr;
        enum clnt_stat stat = RPC_SUCCESS;
        int rpcvers = RPCBVERS4;
        bool_t do_tcp = FALSE;
        bool_t tryagain = FALSE;
        struct portmap mapping;
        u_short port = 0;
        struct sockaddr_in *sin4;
        char namebuf[INET_ADDRSTRLEN];
#ifdef INET6
        struct sockaddr_in6 *sin6;
        char namebuf6[INET6_ADDRSTRLEN];
#endif

        /*
         * First we need to contact the remote RPCBIND service to find
         * the right port.
         */
        memcpy(&ss, sa, sa->sa_len);
        switch (ss.ss_family) {
        case AF_INET:
                ((struct sockaddr_in *)&ss)->sin_port = htons(111);
                so = nlm_socket;
                break;
#ifdef INET6
        case AF_INET6:
                ((struct sockaddr_in6 *)&ss)->sin6_port = htons(111);
                so = nlm_socket6;
                break;
#endif

        default:
                /*
                 * Unsupported address family - fail.
                 */
                return (NULL);
        }

        rpcb = clnt_dg_create(so, (struct sockaddr *)&ss,
            RPCBPROG, rpcvers, 0, 0);
        if (!rpcb)
                return (NULL);

try_tcp:
        parms.r_prog = prog;
        parms.r_vers = vers;
        if (do_tcp)
                parms.r_netid = "tcp";
        else
                parms.r_netid = "udp";
        parms.r_addr = "";
        parms.r_owner = "";

        /*
         * Use the default timeout.
         */
        timo.tv_sec = 25;
        timo.tv_usec = 0;
again:
        switch (rpcvers) {
        case RPCBVERS4:
        case RPCBVERS:
                /*
                 * Try RPCBIND 4 then 3.
                 */
                uaddr = NULL;
                stat = CLNT_CALL(rpcb, (rpcprog_t) RPCBPROC_GETADDR,
                    (xdrproc_t) xdr_rpcb, &parms,
                    (xdrproc_t) xdr_wrapstring, &uaddr, timo);
                if (stat == RPC_SUCCESS) {
                        /*
                         * We have a reply from the remote RPCBIND - turn it
                         * into an appropriate address and make a new client
                         * that can talk to the remote NLM.
                         *
                         * XXX fixup IPv6 scope ID.
                         */
                        struct netbuf *a;
                        a = __rpc_uaddr2taddr_af(ss.ss_family, uaddr);
                        if (!a) {
                                tryagain = TRUE;
                        } else {
                                tryagain = FALSE;
                                memcpy(&ss, a->buf, a->len);
                                free(a->buf, M_RPC);
                                free(a, M_RPC);
                                xdr_free((xdrproc_t) xdr_wrapstring, &uaddr);
                        }
                }
                if (tryagain || stat == RPC_PROGVERSMISMATCH) {
                        if (rpcvers == RPCBVERS4)
                                rpcvers = RPCBVERS;
                        else if (rpcvers == RPCBVERS)
                                rpcvers = PMAPVERS;
                        CLNT_CONTROL(rpcb, CLSET_VERS, &rpcvers);
                        goto again;
                }
                break;
        case PMAPVERS:
                /*
                 * Try portmap.
                 */
                mapping.pm_prog = parms.r_prog;
                mapping.pm_vers = parms.r_vers;
                mapping.pm_prot = do_tcp ? IPPROTO_TCP : IPPROTO_UDP;
                mapping.pm_port = 0;

                stat = CLNT_CALL(rpcb, (rpcprog_t) PMAPPROC_GETPORT,
                    (xdrproc_t) xdr_portmap, &mapping,
                    (xdrproc_t) xdr_u_short, &port, timo);

                if (stat == RPC_SUCCESS) {
                        switch (ss.ss_family) {
                        case AF_INET:
                                ((struct sockaddr_in *)&ss)->sin_port =
                                        htons(port);
                                break;
                
#ifdef INET6
                        case AF_INET6:
                                ((struct sockaddr_in6 *)&ss)->sin6_port =
                                        htons(port);
                                break;
#endif
                        }
                }
                break;
        default:
                panic("invalid rpcvers %d", rpcvers);
        }
        /*
         * We may have a positive response from the portmapper, but the NLM
         * service was not found. Make sure we received a valid port.
         */
        switch (ss.ss_family) {
        case AF_INET:
                port = ((struct sockaddr_in *)&ss)->sin_port;
                break;
#ifdef INET6
        case AF_INET6:
                port = ((struct sockaddr_in6 *)&ss)->sin6_port;
                break;
#endif
        }
        if (stat != RPC_SUCCESS || !port) {
                /*
                 * If we were able to talk to rpcbind or portmap, but the udp
                 * variant wasn't available, ask about tcp.
                 *
                 * XXX - We could also check for a TCP portmapper, but
                 * if the host is running a portmapper at all, we should be able
                 * to hail it over UDP.
                 */
                if (stat == RPC_SUCCESS && !do_tcp) {
                        do_tcp = TRUE;
                        goto try_tcp;
                }

                /* Otherwise, bad news. */
                switch (ss.ss_family) {
                        case AF_INET:
                                sin4 = (struct sockaddr_in *)&ss;
                                inet_ntop(ss.ss_family, &sin4->sin_addr,
                                    namebuf, sizeof namebuf);
                                NLM_ERR("NLM: failed to contact remote rpcbind, "
                                    "stat = %d, host = %s, port = %d\n",
                                    (int) stat, namebuf, htons(port));
                                break;
#ifdef INET6
                        case AF_INET6:
                                sin6 = (struct sockaddr_in6 *)&ss;
                                inet_ntop(ss.ss_family, &sin6->sin6_addr,
                                    namebuf6, sizeof namebuf6);
                                NLM_ERR("NLM: failed to contact remote rpcbind, "
                                    "stat = %d, host = %s, port = %d\n",
                                    (int) stat, namebuf6, htons(port));
                                break;
#endif
                }
                CLNT_DESTROY(rpcb);
                return (NULL);
        }

        if (do_tcp) {
                /*
                 * Destroy the UDP client we used to speak to rpcbind and
                 * recreate as a TCP client.
                 */
                struct netconfig *nconf = NULL;

                CLNT_DESTROY(rpcb);

                switch (ss.ss_family) {
                case AF_INET:
                        nconf = getnetconfigent("tcp");
                        break;
#ifdef INET6
                case AF_INET6:
                        nconf = getnetconfigent("tcp6");
                        break;
#endif
                }

                rpcb = clnt_reconnect_create(nconf, (struct sockaddr *)&ss,
                    prog, vers, 0, 0);
                CLNT_CONTROL(rpcb, CLSET_WAITCHAN, wchan);
                rpcb->cl_auth = nlm_auth;
                
        } else {
                /*
                 * Re-use the client we used to speak to rpcbind.
                 */
                CLNT_CONTROL(rpcb, CLSET_SVC_ADDR, &ss);
                CLNT_CONTROL(rpcb, CLSET_PROG, &prog);
                CLNT_CONTROL(rpcb, CLSET_VERS, &vers);
                CLNT_CONTROL(rpcb, CLSET_WAITCHAN, wchan);
                rpcb->cl_auth = nlm_auth;
        }

        return (rpcb);
}

/*
 * This async callback after when an async lock request has been
 * granted. We notify the host which initiated the request.
 */
static void
nlm_lock_callback(void *arg, int pending)
{
        struct nlm_async_lock *af = (struct nlm_async_lock *) arg;
        struct rpc_callextra ext;

        NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) granted,"
            " cookie %d:%d\n", af, af->af_host->nh_caller_name,
            af->af_host->nh_sysid, ng_sysid(&af->af_granted.cookie),
            ng_cookie(&af->af_granted.cookie));

        /*
         * Send the results back to the host.
         *
         * Note: there is a possible race here with nlm_host_notify
         * destroying the RPC client. To avoid problems, the first
         * thing nlm_host_notify does is to cancel pending async lock
         * requests.
         */
        memset(&ext, 0, sizeof(ext));
        ext.rc_auth = nlm_auth;
        if (af->af_host->nh_vers == NLM_VERS4) {
                nlm4_granted_msg_4(&af->af_granted,
                    NULL, af->af_rpc, &ext, nlm_zero_tv);
        } else {
                /*
                 * Back-convert to legacy protocol
                 */
                nlm_testargs granted;
                granted.cookie = af->af_granted.cookie;
                granted.exclusive = af->af_granted.exclusive;
                granted.alock.caller_name =
                        af->af_granted.alock.caller_name;
                granted.alock.fh = af->af_granted.alock.fh;
                granted.alock.oh = af->af_granted.alock.oh;
                granted.alock.svid = af->af_granted.alock.svid;
                granted.alock.l_offset =
                        af->af_granted.alock.l_offset;
                granted.alock.l_len =
                        af->af_granted.alock.l_len;

                nlm_granted_msg_1(&granted,
                    NULL, af->af_rpc, &ext, nlm_zero_tv);
        }

        /*
         * Move this entry to the nh_granted list.
         */
        af->af_expiretime = time_uptime + NLM_EXPIRE_TIMEOUT;
        mtx_lock(&af->af_host->nh_lock);
        TAILQ_REMOVE(&af->af_host->nh_pending, af, af_link);
        TAILQ_INSERT_TAIL(&af->af_host->nh_granted, af, af_link);
        mtx_unlock(&af->af_host->nh_lock);
}

/*
 * Free an async lock request. The request must have been removed from
 * any list.
 */
static void
nlm_free_async_lock(struct nlm_async_lock *af)
{
        /*
         * Free an async lock.
         */
        if (af->af_rpc)
                CLNT_RELEASE(af->af_rpc);
        xdr_free((xdrproc_t) xdr_nlm4_testargs, &af->af_granted);
        if (af->af_vp)
                vrele(af->af_vp);
        free(af, M_NLM);
}

/*
 * Cancel our async request - this must be called with
 * af->nh_host->nh_lock held. This is slightly complicated by a
 * potential race with our own callback. If we fail to cancel the
 * lock, it must already have been granted - we make sure our async
 * task has completed by calling taskqueue_drain in this case.
 */
static int
nlm_cancel_async_lock(struct nlm_async_lock *af)
{
        struct nlm_host *host = af->af_host;
        int error;

        mtx_assert(&host->nh_lock, MA_OWNED);

        mtx_unlock(&host->nh_lock);

        error = VOP_ADVLOCKASYNC(af->af_vp, NULL, F_CANCEL, &af->af_fl,
            F_REMOTE, NULL, &af->af_cookie);

        if (error) {
                /*
                 * We failed to cancel - make sure our callback has
                 * completed before we continue.
                 */
                taskqueue_drain(taskqueue_thread, &af->af_task);
        }

        mtx_lock(&host->nh_lock);

        if (!error) {
                NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) "
                    "cancelled\n", af, host->nh_caller_name, host->nh_sysid);

                /*
                 * Remove from the nh_pending list and free now that
                 * we are safe from the callback.
                 */
                TAILQ_REMOVE(&host->nh_pending, af, af_link);
                mtx_unlock(&host->nh_lock);
                nlm_free_async_lock(af);
                mtx_lock(&host->nh_lock);
        }

        return (error);
}

static void
nlm_check_expired_locks(struct nlm_host *host)
{
        struct nlm_async_lock *af;
        time_t uptime = time_uptime;

        mtx_lock(&host->nh_lock);
        while ((af = TAILQ_FIRST(&host->nh_granted)) != NULL
            && uptime >= af->af_expiretime) {
                NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) expired,"
                    " cookie %d:%d\n", af, af->af_host->nh_caller_name,
                    af->af_host->nh_sysid, ng_sysid(&af->af_granted.cookie),
                    ng_cookie(&af->af_granted.cookie));
                TAILQ_REMOVE(&host->nh_granted, af, af_link);
                mtx_unlock(&host->nh_lock);
                nlm_free_async_lock(af);
                mtx_lock(&host->nh_lock);
        }
        while ((af = TAILQ_FIRST(&host->nh_finished)) != NULL) {
                TAILQ_REMOVE(&host->nh_finished, af, af_link);
                mtx_unlock(&host->nh_lock);
                nlm_free_async_lock(af);
                mtx_lock(&host->nh_lock);
        }
        mtx_unlock(&host->nh_lock);
}

/*
 * Free resources used by a host. This is called after the reference
 * count has reached zero so it doesn't need to worry about locks.
 */
static void
nlm_host_destroy(struct nlm_host *host)
{

        mtx_lock(&nlm_global_lock);
        TAILQ_REMOVE(&nlm_hosts, host, nh_link);
        mtx_unlock(&nlm_global_lock);

        if (host->nh_srvrpc.nr_client)
                CLNT_RELEASE(host->nh_srvrpc.nr_client);
        if (host->nh_clntrpc.nr_client)
                CLNT_RELEASE(host->nh_clntrpc.nr_client);
        mtx_destroy(&host->nh_lock);
        sysctl_ctx_free(&host->nh_sysctl);
        free(host, M_NLM);
}

/*
 * Thread start callback for client lock recovery
 */
static void
nlm_client_recovery_start(void *arg)
{
        struct nlm_host *host = (struct nlm_host *) arg;

        NLM_DEBUG(1, "NLM: client lock recovery for %s started\n",
            host->nh_caller_name);

        nlm_client_recovery(host);

        NLM_DEBUG(1, "NLM: client lock recovery for %s completed\n",
            host->nh_caller_name);

        host->nh_monstate = NLM_MONITORED;
        nlm_host_release(host);

        kthread_exit();
}

/*
 * This is called when we receive a host state change notification. We
 * unlock any active locks owned by the host. When rpc.lockd is
 * shutting down, this function is called with newstate set to zero
 * which allows us to cancel any pending async locks and clear the
 * locking state.
 */
static void
nlm_host_notify(struct nlm_host *host, int newstate)
{
        struct nlm_async_lock *af;

        if (newstate) {
                NLM_DEBUG(1, "NLM: host %s (sysid %d) rebooted, new "
                    "state is %d\n", host->nh_caller_name,
                    host->nh_sysid, newstate);
        }

        /*
         * Cancel any pending async locks for this host.
         */
        mtx_lock(&host->nh_lock);
        while ((af = TAILQ_FIRST(&host->nh_pending)) != NULL) {
                /*
                 * nlm_cancel_async_lock will remove the entry from
                 * nh_pending and free it.
                 */
                nlm_cancel_async_lock(af);
        }
        mtx_unlock(&host->nh_lock);
        nlm_check_expired_locks(host);

        /*
         * The host just rebooted - trash its locks.
         */
        lf_clearremotesys(host->nh_sysid);
        host->nh_state = newstate;

        /*
         * If we have any remote locks for this host (i.e. it
         * represents a remote NFS server that our local NFS client
         * has locks for), start a recovery thread.
         */
        if (newstate != 0
            && host->nh_monstate != NLM_RECOVERING
            && lf_countlocks(NLM_SYSID_CLIENT | host->nh_sysid) > 0) {
                struct thread *td;
                host->nh_monstate = NLM_RECOVERING;
                refcount_acquire(&host->nh_refs);
                kthread_add(nlm_client_recovery_start, host, curproc, &td, 0, 0,
                    "NFS lock recovery for %s", host->nh_caller_name);
        }
}

/*
 * Sysctl handler to count the number of locks for a sysid.
 */
static int
nlm_host_lock_count_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct nlm_host *host;
        int count;

        host = oidp->oid_arg1;
        count = lf_countlocks(host->nh_sysid);
        return sysctl_handle_int(oidp, &count, 0, req);
}

/*
 * Sysctl handler to count the number of client locks for a sysid.
 */
static int
nlm_host_client_lock_count_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct nlm_host *host;
        int count;

        host = oidp->oid_arg1;
        count = lf_countlocks(NLM_SYSID_CLIENT | host->nh_sysid);
        return sysctl_handle_int(oidp, &count, 0, req);
}

/*
 * Create a new NLM host.
 */
static struct nlm_host *
nlm_create_host(const char* caller_name)
{
        struct nlm_host *host;
        struct sysctl_oid *oid;

        mtx_assert(&nlm_global_lock, MA_OWNED);

        NLM_DEBUG(1, "NLM: new host %s (sysid %d)\n",
            caller_name, nlm_next_sysid);
        host = malloc(sizeof(struct nlm_host), M_NLM, M_NOWAIT|M_ZERO);
        if (!host)
                return (NULL);
        mtx_init(&host->nh_lock, "nh_lock", NULL, MTX_DEF);
        refcount_init(&host->nh_refs, 1);
        strlcpy(host->nh_caller_name, caller_name, MAXNAMELEN);
        host->nh_sysid = nlm_next_sysid++;
        snprintf(host->nh_sysid_string, sizeof(host->nh_sysid_string),
                "%d", host->nh_sysid);
        host->nh_vers = 0;
        host->nh_state = 0;
        host->nh_monstate = NLM_UNMONITORED;
        host->nh_grantcookie = 1;
        TAILQ_INIT(&host->nh_pending);
        TAILQ_INIT(&host->nh_granted);
        TAILQ_INIT(&host->nh_finished);
        TAILQ_INSERT_TAIL(&nlm_hosts, host, nh_link);

        mtx_unlock(&nlm_global_lock);

        sysctl_ctx_init(&host->nh_sysctl);
        oid = SYSCTL_ADD_NODE(&host->nh_sysctl,
            SYSCTL_STATIC_CHILDREN(_vfs_nlm_sysid),
            OID_AUTO, host->nh_sysid_string, CTLFLAG_RD | CTLFLAG_MPSAFE,
            NULL, "");
        SYSCTL_ADD_STRING(&host->nh_sysctl, SYSCTL_CHILDREN(oid), OID_AUTO,
            "hostname", CTLFLAG_RD, host->nh_caller_name, 0, "");
        SYSCTL_ADD_UINT(&host->nh_sysctl, SYSCTL_CHILDREN(oid), OID_AUTO,
            "version", CTLFLAG_RD, &host->nh_vers, 0, "");
        SYSCTL_ADD_UINT(&host->nh_sysctl, SYSCTL_CHILDREN(oid), OID_AUTO,
            "monitored", CTLFLAG_RD, &host->nh_monstate, 0, "");
        SYSCTL_ADD_PROC(&host->nh_sysctl, SYSCTL_CHILDREN(oid), OID_AUTO,
            "lock_count", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, host,
            0, nlm_host_lock_count_sysctl, "I", "");
        SYSCTL_ADD_PROC(&host->nh_sysctl, SYSCTL_CHILDREN(oid), OID_AUTO,
            "client_lock_count", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
            host, 0, nlm_host_client_lock_count_sysctl, "I", "");

        mtx_lock(&nlm_global_lock);

        return (host);
}

/*
 * Acquire the next sysid for remote locks not handled by the NLM.
 */
uint32_t
nlm_acquire_next_sysid(void)
{
        uint32_t next_sysid;

        mtx_lock(&nlm_global_lock);
        next_sysid = nlm_next_sysid++;
        mtx_unlock(&nlm_global_lock);
        return (next_sysid);
}

/*
 * Return non-zero if the address parts of the two sockaddrs are the
 * same.
 */
static int
nlm_compare_addr(const struct sockaddr *a, const struct sockaddr *b)
{
        const struct sockaddr_in *a4, *b4;
#ifdef INET6
        const struct sockaddr_in6 *a6, *b6;
#endif

        if (a->sa_family != b->sa_family)
                return (FALSE);

        switch (a->sa_family) {
        case AF_INET:
                a4 = (const struct sockaddr_in *) a;
                b4 = (const struct sockaddr_in *) b;
                return !memcmp(&a4->sin_addr, &b4->sin_addr,
                    sizeof(a4->sin_addr));
#ifdef INET6
        case AF_INET6:
                a6 = (const struct sockaddr_in6 *) a;
                b6 = (const struct sockaddr_in6 *) b;
                return !memcmp(&a6->sin6_addr, &b6->sin6_addr,
                    sizeof(a6->sin6_addr));
#endif
        }

        return (0);
}

/*
 * Check for idle hosts and stop monitoring them. We could also free
 * the host structure here, possibly after a larger timeout but that
 * would require some care to avoid races with
 * e.g. nlm_host_lock_count_sysctl.
 */
static void
nlm_check_idle(void)
{
        struct nlm_host *host;

        mtx_assert(&nlm_global_lock, MA_OWNED);

        if (time_uptime <= nlm_next_idle_check)
                return;

        nlm_next_idle_check = time_uptime + NLM_IDLE_PERIOD;

        TAILQ_FOREACH(host, &nlm_hosts, nh_link) {
                if (host->nh_monstate == NLM_MONITORED
                    && time_uptime > host->nh_idle_timeout) {
                        mtx_unlock(&nlm_global_lock);
                        if (lf_countlocks(host->nh_sysid) > 0
                            || lf_countlocks(NLM_SYSID_CLIENT
                                + host->nh_sysid)) {
                                host->nh_idle_timeout =
                                        time_uptime + NLM_IDLE_TIMEOUT;
                                mtx_lock(&nlm_global_lock);
                                continue;
                        }
                        nlm_host_unmonitor(host);
                        mtx_lock(&nlm_global_lock);
                } 
        }
}

/*
 * Search for an existing NLM host that matches the given name
 * (typically the caller_name element of an nlm4_lock).  If none is
 * found, create a new host. If 'addr' is non-NULL, record the remote
 * address of the host so that we can call it back for async
 * responses. If 'vers' is greater than zero then record the NLM
 * program version to use to communicate with this client.
 */
struct nlm_host *
nlm_find_host_by_name(const char *name, const struct sockaddr *addr,
    rpcvers_t vers)
{
        struct nlm_host *host;

        mtx_lock(&nlm_global_lock);

        /*
         * The remote host is determined by caller_name.
         */
        TAILQ_FOREACH(host, &nlm_hosts, nh_link) {
                if (!strcmp(host->nh_caller_name, name))
                        break;
        }

        if (!host) {
                host = nlm_create_host(name);
                if (!host) {
                        mtx_unlock(&nlm_global_lock);
                        return (NULL);
                }
        }
        refcount_acquire(&host->nh_refs);

        host->nh_idle_timeout = time_uptime + NLM_IDLE_TIMEOUT;

        /*
         * If we have an address for the host, record it so that we
         * can send async replies etc.
         */
        if (addr) {
                
                KASSERT(addr->sa_len < sizeof(struct sockaddr_storage),
                    ("Strange remote transport address length"));

                /*
                 * If we have seen an address before and we currently
                 * have an RPC client handle, make sure the address is
                 * the same, otherwise discard the client handle.
                 */
                if (host->nh_addr.ss_len && host->nh_srvrpc.nr_client) {
                        if (!nlm_compare_addr(
                                    (struct sockaddr *) &host->nh_addr,
                                    addr)
                            || host->nh_vers != vers) {
                                CLIENT *client;
                                mtx_lock(&host->nh_lock);
                                client = host->nh_srvrpc.nr_client;
                                host->nh_srvrpc.nr_client = NULL;
                                mtx_unlock(&host->nh_lock);
                                if (client) {
                                        CLNT_RELEASE(client);
                                }
                        }
                }
                memcpy(&host->nh_addr, addr, addr->sa_len);
                host->nh_vers = vers;
        }

        nlm_check_idle();

        mtx_unlock(&nlm_global_lock);

        return (host);
}

/*
 * Search for an existing NLM host that matches the given remote
 * address. If none is found, create a new host with the requested
 * address and remember 'vers' as the NLM protocol version to use for
 * that host.
 */
struct nlm_host *
nlm_find_host_by_addr(const struct sockaddr *addr, int vers)
{
        /*
         * Fake up a name using inet_ntop. This buffer is
         * large enough for an IPv6 address.
         */
        char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];
        struct nlm_host *host;

        switch (addr->sa_family) {
        case AF_INET:
                inet_ntop(AF_INET,
                    &((const struct sockaddr_in *) addr)->sin_addr,
                    tmp, sizeof tmp);
                break;
#ifdef INET6
        case AF_INET6:
                inet_ntop(AF_INET6,
                    &((const struct sockaddr_in6 *) addr)->sin6_addr,
                    tmp, sizeof tmp);
                break;
#endif
        default:
                strlcpy(tmp, "<unknown>", sizeof(tmp));
        }

        mtx_lock(&nlm_global_lock);

        /*
         * The remote host is determined by caller_name.
         */
        TAILQ_FOREACH(host, &nlm_hosts, nh_link) {
                if (nlm_compare_addr(addr,
                        (const struct sockaddr *) &host->nh_addr))
                        break;
        }

        if (!host) {
                host = nlm_create_host(tmp);
                if (!host) {
                        mtx_unlock(&nlm_global_lock);
                        return (NULL);
                }
                memcpy(&host->nh_addr, addr, addr->sa_len);
                host->nh_vers = vers;
        }
        refcount_acquire(&host->nh_refs);

        host->nh_idle_timeout = time_uptime + NLM_IDLE_TIMEOUT;

        nlm_check_idle();

        mtx_unlock(&nlm_global_lock);

        return (host);
}

/*
 * Find the NLM host that matches the value of 'sysid'. If none
 * exists, return NULL.
 */
static struct nlm_host *
nlm_find_host_by_sysid(int sysid)
{
        struct nlm_host *host;

        TAILQ_FOREACH(host, &nlm_hosts, nh_link) {
                if (host->nh_sysid == sysid) {
                        refcount_acquire(&host->nh_refs);
                        return (host);
                }
        }

        return (NULL);
}

void nlm_host_release(struct nlm_host *host)
{
        if (refcount_release(&host->nh_refs)) {
                /*
                 * Free the host
                 */
                nlm_host_destroy(host);
        }
}

/*
 * Unregister this NLM host with the local NSM due to idleness.
 */
static void
nlm_host_unmonitor(struct nlm_host *host)
{
        mon_id smmonid;
        sm_stat_res smstat;
        struct timeval timo;
        enum clnt_stat stat;

        NLM_DEBUG(1, "NLM: unmonitoring %s (sysid %d)\n",
            host->nh_caller_name, host->nh_sysid);

        /*
         * We put our assigned system ID value in the priv field to
         * make it simpler to find the host if we are notified of a
         * host restart.
         */
        smmonid.mon_name = host->nh_caller_name;
        smmonid.my_id.my_name = "localhost";
        smmonid.my_id.my_prog = NLM_PROG;
        smmonid.my_id.my_vers = NLM_SM;
        smmonid.my_id.my_proc = NLM_SM_NOTIFY;

        timo.tv_sec = 25;
        timo.tv_usec = 0;
        stat = CLNT_CALL(nlm_nsm, SM_UNMON,
            (xdrproc_t) xdr_mon, &smmonid,
            (xdrproc_t) xdr_sm_stat, &smstat, timo);

        if (stat != RPC_SUCCESS) {
                NLM_ERR("Failed to contact local NSM - rpc error %d\n", stat);
                return;
        }
        if (smstat.res_stat == stat_fail) {
                NLM_ERR("Local NSM refuses to unmonitor %s\n",
                    host->nh_caller_name);
                return;
        }

        host->nh_monstate = NLM_UNMONITORED;
}

/*
 * Register this NLM host with the local NSM so that we can be
 * notified if it reboots.
 */
void
nlm_host_monitor(struct nlm_host *host, int state)
{
        mon smmon;
        sm_stat_res smstat;
        struct timeval timo;
        enum clnt_stat stat;

        if (state && !host->nh_state) {
                /*
                 * This is the first time we have seen an NSM state
                 * value for this host. We record it here to help
                 * detect host reboots.
                 */
                host->nh_state = state;
                NLM_DEBUG(1, "NLM: host %s (sysid %d) has NSM state %d\n",
                    host->nh_caller_name, host->nh_sysid, state);
        }

        mtx_lock(&host->nh_lock);
        if (host->nh_monstate != NLM_UNMONITORED) {
                mtx_unlock(&host->nh_lock);
                return;
        }
        host->nh_monstate = NLM_MONITORED;
        mtx_unlock(&host->nh_lock);

        NLM_DEBUG(1, "NLM: monitoring %s (sysid %d)\n",
            host->nh_caller_name, host->nh_sysid);

        /*
         * We put our assigned system ID value in the priv field to
         * make it simpler to find the host if we are notified of a
         * host restart.
         */
        smmon.mon_id.mon_name = host->nh_caller_name;
        smmon.mon_id.my_id.my_name = "localhost";
        smmon.mon_id.my_id.my_prog = NLM_PROG;
        smmon.mon_id.my_id.my_vers = NLM_SM;
        smmon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;
        memcpy(smmon.priv, &host->nh_sysid, sizeof(host->nh_sysid));

        timo.tv_sec = 25;
        timo.tv_usec = 0;
        stat = CLNT_CALL(nlm_nsm, SM_MON,
            (xdrproc_t) xdr_mon, &smmon,
            (xdrproc_t) xdr_sm_stat, &smstat, timo);

        if (stat != RPC_SUCCESS) {
                NLM_ERR("Failed to contact local NSM - rpc error %d\n", stat);
                return;
        }
        if (smstat.res_stat == stat_fail) {
                NLM_ERR("Local NSM refuses to monitor %s\n",
                    host->nh_caller_name);
                mtx_lock(&host->nh_lock);
                host->nh_monstate = NLM_MONITOR_FAILED;
                mtx_unlock(&host->nh_lock);
                return;
        }

        host->nh_monstate = NLM_MONITORED;
}

/*
 * Return an RPC client handle that can be used to talk to the NLM
 * running on the given host.
 */
CLIENT *
nlm_host_get_rpc(struct nlm_host *host, bool_t isserver)
{
        struct nlm_rpc *rpc;
        CLIENT *client;

        mtx_lock(&host->nh_lock);

        if (isserver)
                rpc = &host->nh_srvrpc;
        else
                rpc = &host->nh_clntrpc;

        /*
         * We can't hold onto RPC handles for too long - the async
         * call/reply protocol used by some NLM clients makes it hard
         * to tell when they change port numbers (e.g. after a
         * reboot). Note that if a client reboots while it isn't
         * holding any locks, it won't bother to notify us. We
         * expire the RPC handles after two minutes.
         */
        if (rpc->nr_client && time_uptime > rpc->nr_create_time + 2*60) {
                client = rpc->nr_client;
                rpc->nr_client = NULL;
                mtx_unlock(&host->nh_lock);
                CLNT_RELEASE(client);
                mtx_lock(&host->nh_lock);
        }

        if (!rpc->nr_client) {
                mtx_unlock(&host->nh_lock);
                client = nlm_get_rpc((struct sockaddr *)&host->nh_addr,
                    NLM_PROG, host->nh_vers);
                mtx_lock(&host->nh_lock);

                if (client) {
                        if (rpc->nr_client) {
                                mtx_unlock(&host->nh_lock);
                                CLNT_DESTROY(client);
                                mtx_lock(&host->nh_lock);
                        } else {
                                rpc->nr_client = client;
                                rpc->nr_create_time = time_uptime;
                        }
                }
        }

        client = rpc->nr_client;
        if (client)
                CLNT_ACQUIRE(client);
        mtx_unlock(&host->nh_lock);

        return (client);

}

int nlm_host_get_sysid(struct nlm_host *host)
{

        return (host->nh_sysid);
}

int
nlm_host_get_state(struct nlm_host *host)
{

        return (host->nh_state);
}

void *
nlm_register_wait_lock(struct nlm4_lock *lock, struct vnode *vp)
{
        struct nlm_waiting_lock *nw;

        nw = malloc(sizeof(struct nlm_waiting_lock), M_NLM, M_WAITOK);
        nw->nw_lock = *lock;
        memcpy(&nw->nw_fh.fh_bytes, nw->nw_lock.fh.n_bytes,
            nw->nw_lock.fh.n_len);
        nw->nw_lock.fh.n_bytes = nw->nw_fh.fh_bytes;
        nw->nw_waiting = TRUE;
        nw->nw_vp = vp;
        mtx_lock(&nlm_global_lock);
        TAILQ_INSERT_TAIL(&nlm_waiting_locks, nw, nw_link);
        mtx_unlock(&nlm_global_lock);

        return nw;
}

void
nlm_deregister_wait_lock(void *handle)
{
        struct nlm_waiting_lock *nw = handle;

        mtx_lock(&nlm_global_lock);
        TAILQ_REMOVE(&nlm_waiting_locks, nw, nw_link);
        mtx_unlock(&nlm_global_lock);

        free(nw, M_NLM);
}

int
nlm_wait_lock(void *handle, int timo)
{
        struct nlm_waiting_lock *nw = handle;
        int error, stops_deferred;

        /*
         * If the granted message arrived before we got here,
         * nw->nw_waiting will be FALSE - in that case, don't sleep.
         */
        mtx_lock(&nlm_global_lock);
        error = 0;
        if (nw->nw_waiting) {
                stops_deferred = sigdeferstop(SIGDEFERSTOP_ERESTART);
                error = msleep(nw, &nlm_global_lock, PCATCH, "nlmlock", timo);
                sigallowstop(stops_deferred);
        }
        TAILQ_REMOVE(&nlm_waiting_locks, nw, nw_link);
        if (error) {
                /*
                 * The granted message may arrive after the
                 * interrupt/timeout but before we manage to lock the
                 * mutex. Detect this by examining nw_lock.
                 */
                if (!nw->nw_waiting)
                        error = 0;
        } else {
                /*
                 * If nlm_cancel_wait is called, then error will be
                 * zero but nw_waiting will still be TRUE. We
                 * translate this into EINTR.
                 */
                if (nw->nw_waiting)
                        error = EINTR;
        }
        mtx_unlock(&nlm_global_lock);

        free(nw, M_NLM);

        return (error);
}

void
nlm_cancel_wait(struct vnode *vp)
{
        struct nlm_waiting_lock *nw;

        mtx_lock(&nlm_global_lock);
        TAILQ_FOREACH(nw, &nlm_waiting_locks, nw_link) {
                if (nw->nw_vp == vp) {
                        wakeup(nw);
                }
        }
        mtx_unlock(&nlm_global_lock);
}

/**********************************************************************/

/*
 * Syscall interface with userland.
 */

extern void nlm_prog_0(struct svc_req *rqstp, SVCXPRT *transp);
extern void nlm_prog_1(struct svc_req *rqstp, SVCXPRT *transp);
extern void nlm_prog_3(struct svc_req *rqstp, SVCXPRT *transp);
extern void nlm_prog_4(struct svc_req *rqstp, SVCXPRT *transp);

static int
nlm_register_services(SVCPOOL *pool, int addr_count, char **addrs)
{
        static rpcvers_t versions[] = {
                NLM_SM, NLM_VERS, NLM_VERSX, NLM_VERS4
        };
        static void (*dispatchers[])(struct svc_req *, SVCXPRT *) = {
                nlm_prog_0, nlm_prog_1, nlm_prog_3, nlm_prog_4
        };

        SVCXPRT **xprts;
        char netid[16];
        char uaddr[128];
        struct netconfig *nconf;
        int i, j, error;

        if (!addr_count) {
                NLM_ERR("NLM: no service addresses given - can't start server");
                return (EINVAL);
        }

        if (addr_count < 0 || addr_count > 256 ) {
                NLM_ERR("NLM:  too many service addresses (%d) given, "
                    "max 256 - can't start server\n", addr_count);
                return (EINVAL);
        }

        xprts = malloc(addr_count * sizeof(SVCXPRT *), M_NLM, M_WAITOK|M_ZERO);
        for (i = 0; i < nitems(versions); i++) {
                for (j = 0; j < addr_count; j++) {
                        /*
                         * Create transports for the first version and
                         * then just register everything else to the
                         * same transports.
                         */
                        if (i == 0) {
                                char *up;

                                error = copyin(&addrs[2*j], &up,
                                    sizeof(char*));
                                if (error)
                                        goto out;
                                error = copyinstr(up, netid, sizeof(netid),
                                    NULL);
                                if (error)
                                        goto out;
                                error = copyin(&addrs[2*j+1], &up,
                                    sizeof(char*));
                                if (error)
                                        goto out;
                                error = copyinstr(up, uaddr, sizeof(uaddr),
                                    NULL);
                                if (error)
                                        goto out;
                                nconf = getnetconfigent(netid);
                                if (!nconf) {
                                        NLM_ERR("Can't lookup netid %s\n",
                                            netid);
                                        error = EINVAL;
                                        goto out;
                                }
                                xprts[j] = svc_tp_create(pool, dispatchers[i],
                                    NLM_PROG, versions[i], uaddr, nconf);
                                if (!xprts[j]) {
                                        NLM_ERR("NLM: unable to create "
                                            "(NLM_PROG, %d).\n", versions[i]);
                                        error = EINVAL;
                                        goto out;
                                }
                                freenetconfigent(nconf);
                        } else {
                                nconf = getnetconfigent(xprts[j]->xp_netid);
                                rpcb_unset(NLM_PROG, versions[i], nconf);
                                if (!svc_reg(xprts[j], NLM_PROG, versions[i],
                                        dispatchers[i], nconf)) {
                                        NLM_ERR("NLM: can't register "
                                            "(NLM_PROG, %d)\n", versions[i]);
                                        error = EINVAL;
                                        goto out;
                                }
                        }
                }
        }
        error = 0;
out:
        for (j = 0; j < addr_count; j++) {
                if (xprts[j])
                        SVC_RELEASE(xprts[j]);
        }
        free(xprts, M_NLM);
        return (error);
}

/*
 * Main server entry point. Contacts the local NSM to get its current
 * state and send SM_UNMON_ALL. Registers the NLM services and then
 * services requests. Does not return until the server is interrupted
 * by a signal.
 */
static int
nlm_server_main(int addr_count, char **addrs)
{
        struct thread *td = curthread;
        int error;
        SVCPOOL *pool = NULL;
        struct sockopt opt;
        int portlow;
#ifdef INET6
        struct sockaddr_in6 sin6;
#endif
        struct sockaddr_in sin;
        my_id id;
        sm_stat smstat;
        struct timeval timo;
        enum clnt_stat stat;
        struct nlm_host *host, *nhost;
        struct nlm_waiting_lock *nw;
        vop_advlock_t *old_nfs_advlock;
        vop_reclaim_t *old_nfs_reclaim;

        if (nlm_is_running != 0) {
                NLM_ERR("NLM: can't start server - "
                    "it appears to be running already\n");
                return (EPERM);
        }

        if (nlm_socket == NULL) {
                memset(&opt, 0, sizeof(opt));

                error = socreate(AF_INET, &nlm_socket, SOCK_DGRAM, 0,
                    td->td_ucred, td);
                if (error) {
                        NLM_ERR("NLM: can't create IPv4 socket - error %d\n",
                            error);
                        return (error);
                }
                opt.sopt_dir = SOPT_SET;
                opt.sopt_level = IPPROTO_IP;
                opt.sopt_name = IP_PORTRANGE;
                portlow = IP_PORTRANGE_LOW;
                opt.sopt_val = &portlow;
                opt.sopt_valsize = sizeof(portlow);
                sosetopt(nlm_socket, &opt);

#ifdef INET6
                nlm_socket6 = NULL;
                error = socreate(AF_INET6, &nlm_socket6, SOCK_DGRAM, 0,
                    td->td_ucred, td);
                if (error) {
                        NLM_ERR("NLM: can't create IPv6 socket - error %d\n",
                            error);
                        soclose(nlm_socket);
                        nlm_socket = NULL;
                        return (error);
                }
                opt.sopt_dir = SOPT_SET;
                opt.sopt_level = IPPROTO_IPV6;
                opt.sopt_name = IPV6_PORTRANGE;
                portlow = IPV6_PORTRANGE_LOW;
                opt.sopt_val = &portlow;
                opt.sopt_valsize = sizeof(portlow);
                sosetopt(nlm_socket6, &opt);
#endif
        }

        nlm_auth = authunix_create(curthread->td_ucred);

#ifdef INET6
        memset(&sin6, 0, sizeof(sin6));
        sin6.sin6_len = sizeof(sin6);
        sin6.sin6_family = AF_INET6;
        sin6.sin6_addr = in6addr_loopback;
        nlm_nsm = nlm_get_rpc((struct sockaddr *) &sin6, SM_PROG, SM_VERS);
        if (!nlm_nsm) {
#endif
                memset(&sin, 0, sizeof(sin));
                sin.sin_len = sizeof(sin);
                sin.sin_family = AF_INET;
                sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
                nlm_nsm = nlm_get_rpc((struct sockaddr *) &sin, SM_PROG,
                    SM_VERS);
#ifdef INET6
        }
#endif

        if (!nlm_nsm) {
                NLM_ERR("Can't start NLM - unable to contact NSM\n");
                error = EINVAL;
                goto out;
        }

        pool = svcpool_create("NLM", NULL);

        error = nlm_register_services(pool, addr_count, addrs);
        if (error)
                goto out;

        memset(&id, 0, sizeof(id));
        id.my_name = "NFS NLM";

        timo.tv_sec = 25;
        timo.tv_usec = 0;
        stat = CLNT_CALL(nlm_nsm, SM_UNMON_ALL,
            (xdrproc_t) xdr_my_id, &id,
            (xdrproc_t) xdr_sm_stat, &smstat, timo);

        if (stat != RPC_SUCCESS) {
                struct rpc_err err;

                CLNT_GETERR(nlm_nsm, &err);
                NLM_ERR("NLM: unexpected error contacting NSM, "
                    "stat=%d, errno=%d\n", stat, err.re_errno);
                error = EINVAL;
                goto out;
        }
        nlm_is_running = 1;

        NLM_DEBUG(1, "NLM: local NSM state is %d\n", smstat.state);
        nlm_nsm_state = smstat.state;

        old_nfs_advlock = nfs_advlock_p;
        nfs_advlock_p = nlm_advlock;
        old_nfs_reclaim = nfs_reclaim_p;
        nfs_reclaim_p = nlm_reclaim;

        svc_run(pool);
        error = 0;

        nfs_advlock_p = old_nfs_advlock;
        nfs_reclaim_p = old_nfs_reclaim;

out:
        nlm_is_running = 0;
        if (pool)
                svcpool_destroy(pool);

        /*
         * We are finished communicating with the NSM.
         */
        if (nlm_nsm) {
                CLNT_RELEASE(nlm_nsm);
                nlm_nsm = NULL;
        }

        /*
         * Trash all the existing state so that if the server
         * restarts, it gets a clean slate. This is complicated by the
         * possibility that there may be other threads trying to make
         * client locking requests.
         *
         * First we fake a client reboot notification which will
         * cancel any pending async locks and purge remote lock state
         * from the local lock manager. We release the reference from
         * nlm_hosts to the host (which may remove it from the list
         * and free it). After this phase, the only entries in the
         * nlm_host list should be from other threads performing
         * client lock requests.
         */
        mtx_lock(&nlm_global_lock);
        TAILQ_FOREACH(nw, &nlm_waiting_locks, nw_link) {
                wakeup(nw);
        }
        TAILQ_FOREACH_SAFE(host, &nlm_hosts, nh_link, nhost) {
                mtx_unlock(&nlm_global_lock);
                nlm_host_notify(host, 0);
                nlm_host_release(host);
                mtx_lock(&nlm_global_lock);
        }
        mtx_unlock(&nlm_global_lock);

        AUTH_DESTROY(nlm_auth);

        return (error);
}

int
sys_nlm_syscall(struct thread *td, struct nlm_syscall_args *uap)
{
        int error;

        error = priv_check(td, PRIV_NFS_LOCKD);
        if (error)
                return (error);

        nlm_debug_level = uap->debug_level;
        nlm_grace_threshold = time_uptime + uap->grace_period;
        nlm_next_idle_check = time_uptime + NLM_IDLE_PERIOD;

        CURVNET_SET(TD_TO_VNET(td));
        error = nlm_server_main(uap->addr_count, uap->addrs);
        CURVNET_RESTORE();

        return (error);
}

/**********************************************************************/

/*
 * NLM implementation details, called from the RPC stubs.
 */

void
nlm_sm_notify(struct nlm_sm_status *argp)
{
        uint32_t sysid;
        struct nlm_host *host;

        NLM_DEBUG(3, "nlm_sm_notify(): mon_name = %s\n", argp->mon_name);
        memcpy(&sysid, &argp->priv, sizeof(sysid));
        host = nlm_find_host_by_sysid(sysid);
        if (host) {
                nlm_host_notify(host, argp->state);
                nlm_host_release(host);
        }
}

static void
nlm_convert_to_fhandle_t(fhandle_t *fhp, struct netobj *p)
{
        memcpy(fhp, p->n_bytes, sizeof(fhandle_t));
}

struct vfs_state {
        struct mount    *vs_mp;
        struct vnode    *vs_vp;
        int             vs_vnlocked;
};

static int
nlm_get_vfs_state(struct nlm_host *host, struct svc_req *rqstp,
    fhandle_t *fhp, struct vfs_state *vs, accmode_t accmode)
{
        int error;
        uint64_t exflags;
        struct ucred *cred = NULL, *credanon = NULL;

        memset(vs, 0, sizeof(*vs));

        vs->vs_mp = vfs_getvfs(&fhp->fh_fsid);
        if (!vs->vs_mp) {
                return (ESTALE);
        }

        /* accmode == 0 means don't check, since it is an unlock. */
        if (accmode != 0) {
                error = VFS_CHECKEXP(vs->vs_mp,
                    (struct sockaddr *)&host->nh_addr, &exflags, &credanon,
                    NULL, NULL);
                if (error)
                        goto out;

                if (exflags & MNT_EXRDONLY ||
                    (vs->vs_mp->mnt_flag & MNT_RDONLY)) {
                        error = EROFS;
                        goto out;
                }
        }

        error = VFS_FHTOVP(vs->vs_mp, &fhp->fh_fid, LK_EXCLUSIVE, &vs->vs_vp);
        if (error)
                goto out;
        vs->vs_vnlocked = TRUE;

        if (accmode != 0) {
                if (!svc_getcred(rqstp, &cred, NULL)) {
                        error = EINVAL;
                        goto out;
                }
                if (cred->cr_uid == 0 || (exflags & MNT_EXPORTANON)) {
                        crfree(cred);
                        cred = credanon;
                        credanon = NULL;
                }

                /*
                 * Check cred.
                 */
                error = VOP_ACCESS(vs->vs_vp, accmode, cred, curthread);
                /*
                 * If this failed and accmode != VWRITE, try again with
                 * VWRITE to maintain backwards compatibility with the
                 * old code that always used VWRITE.
                 */
                if (error != 0 && accmode != VWRITE)
                        error = VOP_ACCESS(vs->vs_vp, VWRITE, cred, curthread);
                if (error)
                        goto out;
        }

        VOP_UNLOCK(vs->vs_vp);
        vs->vs_vnlocked = FALSE;

out:
        if (cred)
                crfree(cred);
        if (credanon)
                crfree(credanon);

        return (error);
}

static void
nlm_release_vfs_state(struct vfs_state *vs)
{

        if (vs->vs_vp) {
                if (vs->vs_vnlocked)
                        vput(vs->vs_vp);
                else
                        vrele(vs->vs_vp);
        }
        if (vs->vs_mp)
                vfs_rel(vs->vs_mp);
}

static nlm4_stats
nlm_convert_error(int error)
{

        if (error == ESTALE)
                return nlm4_stale_fh;
        else if (error == EROFS)
                return nlm4_rofs;
        else
                return nlm4_failed;
}

int
nlm_do_test(nlm4_testargs *argp, nlm4_testres *result, struct svc_req *rqstp,
        CLIENT **rpcp)
{
        fhandle_t fh;
        struct vfs_state vs;
        struct nlm_host *host, *bhost;
        int error, sysid;
        struct flock fl;
        accmode_t accmode;

        memset(result, 0, sizeof(*result));
        memset(&vs, 0, sizeof(vs));

        host = nlm_find_host_by_name(argp->alock.caller_name,
            svc_getrpccaller(rqstp), rqstp->rq_vers);
        if (!host) {
                result->stat.stat = nlm4_denied_nolocks;
                return (ENOMEM);
        }

        NLM_DEBUG(3, "nlm_do_test(): caller_name = %s (sysid = %d)\n",
            host->nh_caller_name, host->nh_sysid);

        nlm_check_expired_locks(host);
        sysid = host->nh_sysid;

        nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
        nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);

        if (time_uptime < nlm_grace_threshold) {
                result->stat.stat = nlm4_denied_grace_period;
                goto out;
        }

        accmode = argp->exclusive ? VWRITE : VREAD;
        error = nlm_get_vfs_state(host, rqstp, &fh, &vs, accmode);
        if (error) {
                result->stat.stat = nlm_convert_error(error);
                goto out;
        }

        fl.l_start = argp->alock.l_offset;
        fl.l_len = argp->alock.l_len;
        fl.l_pid = argp->alock.svid;
        fl.l_sysid = sysid;
        fl.l_whence = SEEK_SET;
        if (argp->exclusive)
                fl.l_type = F_WRLCK;
        else
                fl.l_type = F_RDLCK;
        error = VOP_ADVLOCK(vs.vs_vp, NULL, F_GETLK, &fl, F_REMOTE);
        if (error) {
                result->stat.stat = nlm4_failed;
                goto out;
        }

        if (fl.l_type == F_UNLCK) {
                result->stat.stat = nlm4_granted;
        } else {
                result->stat.stat = nlm4_denied;
                result->stat.nlm4_testrply_u.holder.exclusive =
                        (fl.l_type == F_WRLCK);
                result->stat.nlm4_testrply_u.holder.svid = fl.l_pid;
                bhost = nlm_find_host_by_sysid(fl.l_sysid);
                if (bhost) {
                        /*
                         * We don't have any useful way of recording
                         * the value of oh used in the original lock
                         * request. Ideally, the test reply would have
                         * a space for the owning host's name allowing
                         * our caller's NLM to keep track.
                         *
                         * As far as I can see, Solaris uses an eight
                         * byte structure for oh which contains a four
                         * byte pid encoded in local byte order and
                         * the first four bytes of the host
                         * name. Linux uses a variable length string
                         * 'pid@hostname' in ascii but doesn't even
                         * return that in test replies.
                         *
                         * For the moment, return nothing in oh
                         * (already zero'ed above).
                         */
                        nlm_host_release(bhost);
                }
                result->stat.nlm4_testrply_u.holder.l_offset = fl.l_start;
                result->stat.nlm4_testrply_u.holder.l_len = fl.l_len;
        }

out:
        nlm_release_vfs_state(&vs);
        if (rpcp)
                *rpcp = nlm_host_get_rpc(host, TRUE);
        nlm_host_release(host);
        return (0);
}

int
nlm_do_lock(nlm4_lockargs *argp, nlm4_res *result, struct svc_req *rqstp,
    bool_t monitor, CLIENT **rpcp)
{
        fhandle_t fh;
        struct vfs_state vs;
        struct nlm_host *host;
        int error, sysid;
        struct flock fl;
        accmode_t accmode;

        memset(result, 0, sizeof(*result));
        memset(&vs, 0, sizeof(vs));

        host = nlm_find_host_by_name(argp->alock.caller_name,
            svc_getrpccaller(rqstp), rqstp->rq_vers);
        if (!host) {
                result->stat.stat = nlm4_denied_nolocks;
                return (ENOMEM);
        }

        NLM_DEBUG(3, "nlm_do_lock(): caller_name = %s (sysid = %d)\n",
            host->nh_caller_name, host->nh_sysid);

        if (monitor && host->nh_state && argp->state
            && host->nh_state != argp->state) {
                /*
                 * The host rebooted without telling us. Trash its
                 * locks.
                 */
                nlm_host_notify(host, argp->state);
        }

        nlm_check_expired_locks(host);
        sysid = host->nh_sysid;

        nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
        nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);

        if (time_uptime < nlm_grace_threshold && !argp->reclaim) {
                result->stat.stat = nlm4_denied_grace_period;
                goto out;
        }

        accmode = argp->exclusive ? VWRITE : VREAD;
        error = nlm_get_vfs_state(host, rqstp, &fh, &vs, accmode);
        if (error) {
                result->stat.stat = nlm_convert_error(error);
                goto out;
        }

        fl.l_start = argp->alock.l_offset;
        fl.l_len = argp->alock.l_len;
        fl.l_pid = argp->alock.svid;
        fl.l_sysid = sysid;
        fl.l_whence = SEEK_SET;
        if (argp->exclusive)
                fl.l_type = F_WRLCK;
        else
                fl.l_type = F_RDLCK;
        if (argp->block) {
                struct nlm_async_lock *af;
                CLIENT *client;
                struct nlm_grantcookie cookie;

                /*
                 * First, make sure we can contact the host's NLM.
                 */
                client = nlm_host_get_rpc(host, TRUE);
                if (!client) {
                        result->stat.stat = nlm4_failed;
                        goto out;
                }

                /*
                 * First we need to check and see if there is an
                 * existing blocked lock that matches. This could be a
                 * badly behaved client or an RPC re-send. If we find
                 * one, just return nlm4_blocked.
                 */
                mtx_lock(&host->nh_lock);
                TAILQ_FOREACH(af, &host->nh_pending, af_link) {
                        if (af->af_fl.l_start == fl.l_start
                            && af->af_fl.l_len == fl.l_len
                            && af->af_fl.l_pid == fl.l_pid
                            && af->af_fl.l_type == fl.l_type) {
                                break;
                        }
                }
                if (!af) {
                        cookie.ng_sysid = host->nh_sysid;
                        cookie.ng_cookie = host->nh_grantcookie++;
                }
                mtx_unlock(&host->nh_lock);
                if (af) {
                        CLNT_RELEASE(client);
                        result->stat.stat = nlm4_blocked;
                        goto out;
                }

                af = malloc(sizeof(struct nlm_async_lock), M_NLM,
                    M_WAITOK|M_ZERO);
                TASK_INIT(&af->af_task, 0, nlm_lock_callback, af);
                af->af_vp = vs.vs_vp;
                af->af_fl = fl;
                af->af_host = host;
                af->af_rpc = client;
                /*
                 * We use M_RPC here so that we can xdr_free the thing
                 * later.
                 */
                nlm_make_netobj(&af->af_granted.cookie,
                    (caddr_t)&cookie, sizeof(cookie), M_RPC);
                af->af_granted.exclusive = argp->exclusive;
                af->af_granted.alock.caller_name =
                        strdup(argp->alock.caller_name, M_RPC);
                nlm_copy_netobj(&af->af_granted.alock.fh,
                    &argp->alock.fh, M_RPC);
                nlm_copy_netobj(&af->af_granted.alock.oh,
                    &argp->alock.oh, M_RPC);
                af->af_granted.alock.svid = argp->alock.svid;
                af->af_granted.alock.l_offset = argp->alock.l_offset;
                af->af_granted.alock.l_len = argp->alock.l_len;

                /*
                 * Put the entry on the pending list before calling
                 * VOP_ADVLOCKASYNC. We do this in case the lock
                 * request was blocked (returning EINPROGRESS) but
                 * then granted before we manage to run again. The
                 * client may receive the granted message before we
                 * send our blocked reply but thats their problem.
                 */
                mtx_lock(&host->nh_lock);
                TAILQ_INSERT_TAIL(&host->nh_pending, af, af_link);
                mtx_unlock(&host->nh_lock);

                error = VOP_ADVLOCKASYNC(vs.vs_vp, NULL, F_SETLK, &fl, F_REMOTE,
                    &af->af_task, &af->af_cookie);

                /*
                 * If the lock completed synchronously, just free the
                 * tracking structure now.
                 */
                if (error != EINPROGRESS) {
                        CLNT_RELEASE(af->af_rpc);
                        mtx_lock(&host->nh_lock);
                        TAILQ_REMOVE(&host->nh_pending, af, af_link);
                        mtx_unlock(&host->nh_lock);
                        xdr_free((xdrproc_t) xdr_nlm4_testargs,
                            &af->af_granted);
                        free(af, M_NLM);
                } else {
                        NLM_DEBUG(2, "NLM: pending async lock %p for %s "
                            "(sysid %d)\n", af, host->nh_caller_name, sysid);
                        /*
                         * Don't vrele the vnode just yet - this must
                         * wait until either the async callback
                         * happens or the lock is cancelled.
                         */
                        vs.vs_vp = NULL;
                }
        } else {
                error = VOP_ADVLOCK(vs.vs_vp, NULL, F_SETLK, &fl, F_REMOTE);
        }

        if (error) {
                if (error == EINPROGRESS) {
                        result->stat.stat = nlm4_blocked;
                } else if (error == EDEADLK) {
                        result->stat.stat = nlm4_deadlck;
                } else if (error == EAGAIN) {
                        result->stat.stat = nlm4_denied;
                } else {
                        result->stat.stat = nlm4_failed;
                }
        } else {
                if (monitor)
                        nlm_host_monitor(host, argp->state);
                result->stat.stat = nlm4_granted;
        }       

out:
        nlm_release_vfs_state(&vs);
        if (rpcp)
                *rpcp = nlm_host_get_rpc(host, TRUE);
        nlm_host_release(host);
        return (0);
}

int
nlm_do_cancel(nlm4_cancargs *argp, nlm4_res *result, struct svc_req *rqstp,
    CLIENT **rpcp)
{
        fhandle_t fh;
        struct vfs_state vs;
        struct nlm_host *host;
        int error, sysid;
        struct flock fl;
        struct nlm_async_lock *af;

        memset(result, 0, sizeof(*result));
        memset(&vs, 0, sizeof(vs));

        host = nlm_find_host_by_name(argp->alock.caller_name,
            svc_getrpccaller(rqstp), rqstp->rq_vers);
        if (!host) {
                result->stat.stat = nlm4_denied_nolocks;
                return (ENOMEM);
        }

        NLM_DEBUG(3, "nlm_do_cancel(): caller_name = %s (sysid = %d)\n",
            host->nh_caller_name, host->nh_sysid);

        nlm_check_expired_locks(host);
        sysid = host->nh_sysid;

        nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
        nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);

        if (time_uptime < nlm_grace_threshold) {
                result->stat.stat = nlm4_denied_grace_period;
                goto out;
        }

        error = nlm_get_vfs_state(host, rqstp, &fh, &vs, (accmode_t)0);
        if (error) {
                result->stat.stat = nlm_convert_error(error);
                goto out;
        }

        fl.l_start = argp->alock.l_offset;
        fl.l_len = argp->alock.l_len;
        fl.l_pid = argp->alock.svid;
        fl.l_sysid = sysid;
        fl.l_whence = SEEK_SET;
        if (argp->exclusive)
                fl.l_type = F_WRLCK;
        else
                fl.l_type = F_RDLCK;

        /*
         * First we need to try and find the async lock request - if
         * there isn't one, we give up and return nlm4_denied.
         */
        mtx_lock(&host->nh_lock);

        TAILQ_FOREACH(af, &host->nh_pending, af_link) {
                if (af->af_fl.l_start == fl.l_start
                    && af->af_fl.l_len == fl.l_len
                    && af->af_fl.l_pid == fl.l_pid
                    && af->af_fl.l_type == fl.l_type) {
                        break;
                }
        }

        if (!af) {
                mtx_unlock(&host->nh_lock);
                result->stat.stat = nlm4_denied;
                goto out;
        }

        error = nlm_cancel_async_lock(af);

        if (error) {
                result->stat.stat = nlm4_denied;
        } else {
                result->stat.stat = nlm4_granted;
        }

        mtx_unlock(&host->nh_lock);

out:
        nlm_release_vfs_state(&vs);
        if (rpcp)
                *rpcp = nlm_host_get_rpc(host, TRUE);
        nlm_host_release(host);
        return (0);
}

int
nlm_do_unlock(nlm4_unlockargs *argp, nlm4_res *result, struct svc_req *rqstp,
    CLIENT **rpcp)
{
        fhandle_t fh;
        struct vfs_state vs;
        struct nlm_host *host;
        int error, sysid;
        struct flock fl;

        memset(result, 0, sizeof(*result));
        memset(&vs, 0, sizeof(vs));

        host = nlm_find_host_by_name(argp->alock.caller_name,
            svc_getrpccaller(rqstp), rqstp->rq_vers);
        if (!host) {
                result->stat.stat = nlm4_denied_nolocks;
                return (ENOMEM);
        }

        NLM_DEBUG(3, "nlm_do_unlock(): caller_name = %s (sysid = %d)\n",
            host->nh_caller_name, host->nh_sysid);

        nlm_check_expired_locks(host);
        sysid = host->nh_sysid;

        nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
        nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);

        if (time_uptime < nlm_grace_threshold) {
                result->stat.stat = nlm4_denied_grace_period;
                goto out;
        }

        error = nlm_get_vfs_state(host, rqstp, &fh, &vs, (accmode_t)0);
        if (error) {
                result->stat.stat = nlm_convert_error(error);
                goto out;
        }

        fl.l_start = argp->alock.l_offset;
        fl.l_len = argp->alock.l_len;
        fl.l_pid = argp->alock.svid;
        fl.l_sysid = sysid;
        fl.l_whence = SEEK_SET;
        fl.l_type = F_UNLCK;
        error = VOP_ADVLOCK(vs.vs_vp, NULL, F_UNLCK, &fl, F_REMOTE);

        /*
         * Ignore the error - there is no result code for failure,
         * only for grace period.
         */
        result->stat.stat = nlm4_granted;

out:
        nlm_release_vfs_state(&vs);
        if (rpcp)
                *rpcp = nlm_host_get_rpc(host, TRUE);
        nlm_host_release(host);
        return (0);
}

int
nlm_do_granted(nlm4_testargs *argp, nlm4_res *result, struct svc_req *rqstp,

    CLIENT **rpcp)
{
        struct nlm_host *host;
        struct nlm_waiting_lock *nw;

        memset(result, 0, sizeof(*result));

        host = nlm_find_host_by_addr(svc_getrpccaller(rqstp), rqstp->rq_vers);
        if (!host) {
                result->stat.stat = nlm4_denied_nolocks;
                return (ENOMEM);
        }

        nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);
        result->stat.stat = nlm4_denied;
        KFAIL_POINT_CODE(DEBUG_FP, nlm_deny_grant, goto out);

        mtx_lock(&nlm_global_lock);
        TAILQ_FOREACH(nw, &nlm_waiting_locks, nw_link) {
                if (!nw->nw_waiting)
                        continue;
                if (argp->alock.svid == nw->nw_lock.svid
                    && argp->alock.l_offset == nw->nw_lock.l_offset
                    && argp->alock.l_len == nw->nw_lock.l_len
                    && argp->alock.fh.n_len == nw->nw_lock.fh.n_len
                    && !memcmp(argp->alock.fh.n_bytes, nw->nw_lock.fh.n_bytes,
                        nw->nw_lock.fh.n_len)) {
                        nw->nw_waiting = FALSE;
                        wakeup(nw);
                        result->stat.stat = nlm4_granted;
                        break;
                }
        }
        mtx_unlock(&nlm_global_lock);

out:
        if (rpcp)
                *rpcp = nlm_host_get_rpc(host, TRUE);
        nlm_host_release(host);
        return (0);
}

void
nlm_do_granted_res(nlm4_res *argp, struct svc_req *rqstp)
{
        struct nlm_host *host = NULL;
        struct nlm_async_lock *af = NULL;
        int error;

        if (argp->cookie.n_len != sizeof(struct nlm_grantcookie)) {
                NLM_DEBUG(1, "NLM: bogus grant cookie");
                goto out;
        }

        host = nlm_find_host_by_sysid(ng_sysid(&argp->cookie));
        if (!host) {
                NLM_DEBUG(1, "NLM: Unknown host rejected our grant");
                goto out;
        }

        mtx_lock(&host->nh_lock);
        TAILQ_FOREACH(af, &host->nh_granted, af_link)
            if (ng_cookie(&argp->cookie) ==
                ng_cookie(&af->af_granted.cookie))
                    break;
        if (af)
                TAILQ_REMOVE(&host->nh_granted, af, af_link);
        mtx_unlock(&host->nh_lock);

        if (!af) {
                NLM_DEBUG(1, "NLM: host %s (sysid %d) replied to our grant "
                    "with unrecognized cookie %d:%d", host->nh_caller_name,
                    host->nh_sysid, ng_sysid(&argp->cookie),
                    ng_cookie(&argp->cookie));
                goto out;
        }

        if (argp->stat.stat != nlm4_granted) {
                af->af_fl.l_type = F_UNLCK;
                error = VOP_ADVLOCK(af->af_vp, NULL, F_UNLCK, &af->af_fl, F_REMOTE);
                if (error) {
                        NLM_DEBUG(1, "NLM: host %s (sysid %d) rejected our grant "
                            "and we failed to unlock (%d)", host->nh_caller_name,
                            host->nh_sysid, error);
                        goto out;
                }

                NLM_DEBUG(5, "NLM: async lock %p rejected by host %s (sysid %d)",
                    af, host->nh_caller_name, host->nh_sysid);
        } else {
                NLM_DEBUG(5, "NLM: async lock %p accepted by host %s (sysid %d)",
                    af, host->nh_caller_name, host->nh_sysid);
        }

 out:
        if (af)
                nlm_free_async_lock(af);
        if (host)
                nlm_host_release(host);
}

void
nlm_do_free_all(nlm4_notify *argp)
{
        struct nlm_host *host, *thost;

        TAILQ_FOREACH_SAFE(host, &nlm_hosts, nh_link, thost) {
                if (!strcmp(host->nh_caller_name, argp->name))
                        nlm_host_notify(host, argp->state);
        }
}

/*
 * Kernel module glue
 */
static int
nfslockd_modevent(module_t mod, int type, void *data)
{

        switch (type) {
        case MOD_LOAD:
                return (nlm_init());

        case MOD_UNLOAD:
                nlm_uninit();
                /* The NLM module cannot be safely unloaded. */
                /* FALLTHROUGH */
        default:
                return (EOPNOTSUPP);
        }
}
static moduledata_t nfslockd_mod = {
        "nfslockd",
        nfslockd_modevent,
        NULL,
};
DECLARE_MODULE(nfslockd, nfslockd_mod, SI_SUB_VFS, SI_ORDER_ANY);

/* So that loader and kldload(2) can find us, wherever we are.. */
MODULE_DEPEND(nfslockd, xdr, 1, 1, 1);
MODULE_DEPEND(nfslockd, krpc, 1, 1, 1);
MODULE_DEPEND(nfslockd, nfscommon, 1, 1, 1);
MODULE_VERSION(nfslockd, 1);