/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @(#) Copyright (c) 1989, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)nfsiod.c 8.4 (Berkeley) 5/3/95
 * $FreeBSD: src/sbin/nfsiod/nfsiod.c,v 1.9 1999/08/28 00:13:55 peter Exp $
 */

#include <sys/param.h>
#include <sys/syslog.h>
#include <sys/wait.h>
#include <sys/mount.h>

#include <vfs/nfs/rpcv2.h>
#include <vfs/nfs/nfs.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/* Global defs */
#ifdef DEBUG
int debug = 1;
#else
int debug = 0;
#endif

static void     nonfs(int);
static void     reapchild(int);
static void     usage(void);

/*
 * Nfsiod does asynchronous buffered I/O on behalf of the NFS client.
 * It does not have to be running for correct operation, but will
 * improve throughput.
 */
int
main(int argc, char **argv)
{
        int ch, num_servers;
        struct vfsconf vfc;
        int error;

        error = getvfsbyname("nfs", &vfc);
        if (error && vfsisloadable("nfs")) {
                if (vfsload("nfs"))
                        err(1, "vfsload(nfs)");
                endvfsent();    /* flush cache */
                error = getvfsbyname("nfs", &vfc);
        }
        if(error)
                errx(1, "NFS support is not available in the running kernel");

#define MAXNFSDCNT      20
#define DEFNFSDCNT       1
        num_servers = DEFNFSDCNT;
        while ((ch = getopt(argc, argv, "n:")) != -1)
                switch (ch) {
                case 'n':
                        num_servers = atoi(optarg);
                        if (num_servers < 1 || num_servers > MAXNFSDCNT) {
                                warnx("nfsiod count %d; reset to %d",
                                    num_servers, DEFNFSDCNT);
                                num_servers = DEFNFSDCNT;
                        }
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /*
         * XXX
         * Backward compatibility, trailing number is the count of daemons.
         */
        if (argc > 1)
                usage();
        if (argc == 1) {
                num_servers = atoi(argv[0]);
                if (num_servers < 1 || num_servers > MAXNFSDCNT) {
                        warnx("nfsiod count %d; reset to %d", num_servers,
                            DEFNFSDCNT);
                        num_servers = DEFNFSDCNT;
                }
        }

        if (debug == 0) {
                daemon(0, 0);
                signal(SIGHUP, SIG_IGN);
                signal(SIGINT, SIG_IGN);
                signal(SIGQUIT, SIG_IGN);
                signal(SIGSYS, nonfs);
        }
        signal(SIGCHLD, reapchild);

        openlog("nfsiod:", LOG_PID, LOG_DAEMON);

        while (num_servers--)
                switch (fork()) {
                case -1:
                        syslog(LOG_ERR, "fork: %m");
                        exit (1);
                case 0:
                        if (nfssvc(NFSSVC_BIOD, NULL) < 0) {
                                syslog(LOG_ERR, "nfssvc: %m");
                                exit (1);
                        }
                        exit(0);
                }
        exit (0);
}

static void
nonfs(int signo __unused)
{
        syslog(LOG_ERR, "missing system call: NFS not available");
}

static void
reapchild(int signo __unused)
{

        while (wait3(NULL, WNOHANG, NULL) > 0)
                ;
}

static void
usage(void)
{
        fprintf(stderr, "usage: nfsiod [-n num_servers]\n");
        exit(1);
}