/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * This module provides the user level support for the NFSv4
 * callback program.  It is modeled after nfsd.  When a nfsv4
 * mount occurs, the mount command forks and the child runs
 * start_nfs4_callback.  If this is the first mount, then the
 * process will hang around listening for incoming connection
 * requests from the nfsv4 server.
 *
 * For connection-less protocols, the krpc is started immediately.
 * For connection oriented protocols, the kernel module is informed
 * of netid and universal address that it can give this
 * information to the server during setclientid.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <syslog.h>
#include <tiuser.h>
#include <rpc/rpc.h>
#include <errno.h>
#include <thread.h>
#include <sys/resource.h>
#include <sys/file.h>
#include <nfs/nfs.h>
#include <nfs/nfssys.h>
#include <stdio.h>
#include <stdlib.h>
#include <netconfig.h>
#include <netdir.h>
#include <string.h>
#include <unistd.h>
#include <stropts.h>
#include <sys/tihdr.h>
#include <netinet/tcp.h>
#include "nfs_tbind.h"
#include "thrpool.h"
#include <rpcsvc/nfs4_prot.h>
#include <netdb.h>
#include <signal.h>
#include <strings.h>
#include <priv_utils.h>
#include <rpcsvc/daemon_utils.h>

static  int     nfs4svc(int, struct netbuf *, struct netconfig *, int,
                struct netbuf *);
extern  int     _nfssys(int, void *);

static  char    *MyName;

/*
 * The following are all globals used by routines in nfs_tbind.c.
 */
size_t  end_listen_fds;         /* used by conn_close_oldest() */
size_t  num_fds = 0;            /* used by multiple routines */
int     listen_backlog = 32;    /* used by bind_to_{provider,proto}() */
int     num_servers;            /* used by cots_listen_event() */
int     (*Mysvc)(int, struct netbuf, struct netconfig *) = NULL;
                                /* used by cots_listen_event() */
int     max_conns_allowed = -1; /* used by cots_listen_event() */

int
main(int argc, char *argv[])
{
        int pid;
        int i;
        struct protob *protobp;
        struct flock f;
        pid_t pi;
        struct svcpool_args cb_svcpool;

        MyName = "nfs4cbd";
        Mysvc4 = nfs4svc;

#ifndef DEBUG
        /*
         * Close existing file descriptors, open "/dev/null" as
         * standard input, output, and error, and detach from
         * controlling terminal.
         */
        closefrom(0);
        (void) open("/dev/null", O_RDONLY);
        (void) open("/dev/null", O_WRONLY);
        (void) dup(1);
        (void) setsid();
#endif

        /*
         * create a child to continue our work
         * Parent's exit will tell mount command we're ready to go
         */
        if ((pi = fork()) > 0) {
                exit(0);
        }

        if (pi == -1) {
                (void) syslog(LOG_ERR,
                        "Could not start NFS4_CALLBACK service");
                exit(1);
        }

        (void) _create_daemon_lock(NFS4CBD, DAEMON_UID, DAEMON_GID);

        svcsetprio();

        if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
            DAEMON_UID, DAEMON_GID, PRIV_SYS_NFS, (char *)NULL) == -1) {
                (void) fprintf(stderr, "%s must be run with sufficient"
                        " privileges\n", argv[0]);
                exit(1);
        }
        /* Basic privileges we don't need, remove from E/P. */
        __fini_daemon_priv(PRIV_PROC_EXEC, PRIV_PROC_FORK, PRIV_FILE_LINK_ANY,
            PRIV_PROC_SESSION, PRIV_PROC_INFO, (char *)NULL);

        /*
         * establish our lock on the lock file and write our pid to it.
         * exit if some other process holds the lock, or if there's any
         * error in writing/locking the file.
         */
        pid = _enter_daemon_lock(NFS4CBD);
        switch (pid) {
        case 0:
                break;
        case -1:
                syslog(LOG_ERR, "error locking for %s: %s", NFS4CBD,
                    strerror(errno));
                exit(2);
        default:
                /* daemon was already running */
                exit(0);
        }

        openlog(MyName, LOG_PID | LOG_NDELAY, LOG_DAEMON);

        cb_svcpool.id = NFS_CB_SVCPOOL_ID;
        cb_svcpool.maxthreads = 0;
        cb_svcpool.redline = 0;
        cb_svcpool.qsize = 0;
        cb_svcpool.timeout = 0;
        cb_svcpool.stksize = 0;
        cb_svcpool.max_same_xprt = 0;

        /* create a SVC_POOL for the nfsv4 callback deamon */
        if (_nfssys(SVCPOOL_CREATE, &cb_svcpool)) {
                (void) syslog(LOG_ERR, "can't setup NFS_CB SVCPOOL: Exiting");
                exit(1);
        }

        /*
         * Set up blocked thread to do LWP creation on behalf of the kernel.
         */
        if (svcwait(NFS_CB_SVCPOOL_ID)) {
                (void) syslog(LOG_ERR,
                    "Can't set up NFS_CB LWP creator: Exiting");
                exit(1);
        }


        /*
         * Build a protocol block list for registration.
         */
        protobp = (struct protob *)malloc(sizeof (struct protob));
        protobp->serv = "NFS4_CALLBACK";
        protobp->versmin = NFS_CB;
        protobp->versmax = NFS_CB;
        protobp->program = NFS4_CALLBACK;
        protobp->next = NULL;

        if (do_all(protobp, NULL) == -1) {
                exit(1);
        }

        free(protobp);

        if (num_fds == 0) {
                (void) syslog(LOG_ERR,
                "Could not start NFS4_CALLBACK service for any protocol");
                exit(1);
        }

        end_listen_fds = num_fds;
        /*
         * Poll for non-data control events on the transport descriptors.
         */
        poll_for_action();

        /*
         * If we get here, something failed in poll_for_action().
         */
        return (1);
}

char *
get_uaddr(int fd, struct netconfig *nconf, struct netbuf *nb)
{
        struct nfs_svc_args nsa;
        char *ua, *ua2, *mua = NULL;
        char me[MAXHOSTNAMELEN];
        struct nd_addrlist *nas;
        struct nd_hostserv hs;
        struct nd_mergearg ma;

        ua = taddr2uaddr(nconf, nb);

        if (ua == NULL) {
#ifdef  DEBUG
                fprintf(stderr, "taddr2uaddr failed for netid %s\n",
                        nconf->nc_netid);
#endif
                return (NULL);
        }

        gethostname(me, MAXHOSTNAMELEN);

        hs.h_host = me;
        hs.h_serv = "nfs";
        if (netdir_getbyname(nconf, &hs, &nas)) {
#ifdef DEBUG
                netdir_perror("netdir_getbyname");
#endif
                return (NULL);
        }

        ua2 = taddr2uaddr(nconf, nas->n_addrs);

        if (ua2 == NULL) {
#ifdef  DEBUG
                fprintf(stderr, "taddr2uaddr failed for netid %s.\n",
                        nconf->nc_netid);
#endif
                return (NULL);
        }

        ma.s_uaddr = ua;
        ma.c_uaddr = ua2;
        ma.m_uaddr = NULL;

        if (netdir_options(nconf, ND_MERGEADDR, 0, (char *)&ma)) {
#ifdef DEBUG
                netdir_perror("netdir_options");
#endif
                return (NULL);
        }

        mua = ma.m_uaddr;
        return (mua);
}

/*
 * Establish NFS4 callback service thread.
 */
static int
nfs4svc(int fd, struct netbuf *addrmask, struct netconfig *nconf,
        int cmd, struct netbuf *addr)
{
        struct nfs4_svc_args nsa;
        char *ua;
        int error;

        ua = get_uaddr(fd, nconf, addr);

        if (ua == NULL) {
                syslog(LOG_NOTICE, "nfsv4 cannot determine local hostname "
                        "binding for transport %s - delegations will not be "
                        "available on this transport\n", nconf->nc_netid);
                return (0);
        }

#ifdef  DEBUG
        if (cmd & NFS4_KRPC_START)
                fprintf(stderr, "nfs4cbd: starting callback rpc on %s %s\n",
                        nconf->nc_netid, ua);
        else
                fprintf(stderr, "nfs4cbd: listening on %s %s\n",
                        nconf->nc_netid, ua);
#endif

        nsa.fd = fd;
        nsa.cmd = cmd;
        nsa.netid = nconf->nc_netid;
        if (addrmask)
                nsa.addrmask = *addrmask;
        else
                bzero(&nsa.addrmask, sizeof (struct netbuf));
        nsa.addr = ua;
        nsa.protofmly = nconf->nc_protofmly;
        nsa.proto = nconf->nc_proto;
        if ((error = _nfssys(NFS4_SVC, &nsa)) != 0)
                syslog(LOG_ERR, "nfssys NFS4_SVC failed\n");

        return (error);
}