/*
 * Copyright (c) 1989, 1993, 1994
 *      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, 1994 The Regents of the University of California.  All rights reserved.
 * @(#)nfsd.c   8.9 (Berkeley) 3/29/95
 * $FreeBSD: src/usr.sbin/nfsd/nfsd.c,v 1.34 2005/12/21 10:12:05 delphij Exp $
 */

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

#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>

#include <netdb.h>
#include <arpa/inet.h>
#include <vfs/nfs/rpcv2.h>
#include <vfs/nfs/nfsproto.h>
#include <vfs/nfs/nfs.h>

#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/* Global defs */
#ifdef DEBUG
#define syslog(e, s...) fprintf(stderr,s)
int     debug = 1;
#else
int     debug = 0;
#endif

struct nfsd_srvargs nsd;

#define MAXNFSDCNT      256
#define DEFNFSDCNT       4
pid_t   children[MAXNFSDCNT];   /* PIDs of children */
int     nfsdcnt;                /* number of children */

void    cleanup(int) __dead2;
void    child_cleanup(int) __dead2;
void    killchildren(void);
void    nfsd_exit(int) __dead2;
void    nonfs(int);
void    reapchild(int);
int     setbindhost(struct addrinfo **ia, const char *bindhost,
            struct addrinfo hints);
void    start_server(int) __dead2;
void    unregistration(void);
void    usage(void) __dead2;

/*
 * Nfs server daemon mostly just a user context for nfssvc()
 *
 * 1 - do file descriptor and signal cleanup
 * 2 - fork the nfsd(s)
 * 3 - create server socket(s)
 * 4 - register socket with rpcbind
 *
 * For connectionless protocols, just pass the socket into the kernel via.
 * nfssvc().
 * For connection based sockets, loop doing accepts. When you get a new
 * socket from accept, pass the msgsock into the kernel via. nfssvc().
 * The arguments are:
 *      -r - reregister with rpcbind
 *      -d - unregister with rpcbind
 *      -t - support tcp nfs clients
 *      -u - support udp nfs clients
 * followed by "n" which is the number of nfsds' to fork off
 */
int
main(int argc, char **argv)
{
        struct nfsd_args nfsdargs;
        struct addrinfo *ai_udp, *ai_tcp, *ai_udp6, *ai_tcp6, hints;
        struct netconfig *nconf_udp, *nconf_tcp, *nconf_udp6, *nconf_tcp6;
        struct netbuf nb_udp, nb_tcp, nb_udp6, nb_tcp6;
        struct sockaddr_in inetpeer;
        struct sockaddr_in6 inet6peer;
        fd_set ready, sockbits;
        fd_set v4bits, v6bits;
        int ch, connect_type_cnt, i, maxsock, msgsock;
        socklen_t len;
        int on = 1, unregister, reregister, sock;
        int tcp6sock, ip6flag, tcpflag, tcpsock;
        int udpflag, ecode, s, srvcnt;
        int bindhostc, bindanyflag, rpcbreg, rpcbregcnt;
        char **bindhost = NULL;
        pid_t pid;
        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 is not available in the running kernel");

        nfsdcnt = DEFNFSDCNT;
        unregister = reregister = tcpflag = maxsock = 0;
        bindanyflag = udpflag = connect_type_cnt = bindhostc = 0;
#define GETOPT  "ah:n:rdtu"
#define USAGE   "[-ardtu] [-n num_servers] [-h bindip]"
        while ((ch = getopt(argc, argv, GETOPT)) != -1)
                switch (ch) {
                case 'a':
                        bindanyflag = 1;
                        break;
                case 'n':
                        nfsdcnt = atoi(optarg);
                        if (nfsdcnt < 1 || nfsdcnt > MAXNFSDCNT) {
                                warnx("nfsd count %d; reset to %d", nfsdcnt,
                                    DEFNFSDCNT);
                                nfsdcnt = DEFNFSDCNT;
                        }
                        break;
                case 'h':
                        bindhostc++;
                        bindhost = realloc(bindhost,sizeof(char *)*bindhostc);
                        if (bindhost == NULL)
                                errx(1, "Out of memory");
                        bindhost[bindhostc-1] = strdup(optarg);
                        if (bindhost[bindhostc-1] == NULL)
                                errx(1, "Out of memory");
                        break;
                case 'r':
                        reregister = 1;
                        break;
                case 'd':
                        unregister = 1;
                        break;
                case 't':
                        tcpflag = 1;
                        break;
                case 'u':
                        udpflag = 1;
                        break;
                default:
                case '?':
                        usage();
                }
        if (!tcpflag && !udpflag)
                udpflag = 1;
        argv += optind;
        argc -= optind;

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

        ip6flag = 1;
        s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
        if (s == -1) {
                if (errno != EPROTONOSUPPORT)
                        err(1, "socket");
                ip6flag = 0;
        } else if (getnetconfigent("udp6") == NULL ||
                getnetconfigent("tcp6") == NULL) {
                ip6flag = 0;
        }
        if (s != -1)
                close(s);

        if (bindhostc == 0 || bindanyflag) {
                bindhostc++;
                bindhost = realloc(bindhost,sizeof(char *)*bindhostc);
                if (bindhost == NULL)
                        errx(1, "Out of memory");
                bindhost[bindhostc-1] = strdup("*");
                if (bindhost[bindhostc-1] == NULL)
                        errx(1, "Out of memory");
        }

        if (unregister) {
                unregistration();
                exit (0);
        }
        if (debug == 0) {
                daemon(0, 0);
                signal(SIGHUP, SIG_IGN);
                signal(SIGINT, SIG_IGN);
                /*
                 * nfsd sits in the kernel most of the time.  It needs
                 * to ignore SIGTERM/SIGQUIT in order to stay alive as long
                 * as possible during a shutdown, otherwise loopback
                 * mounts will not be able to unmount.
                 */
                signal(SIGTERM, SIG_IGN);
                signal(SIGQUIT, SIG_IGN);
        }
        if (reregister) {
                if (udpflag) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp);
                        if (ecode != 0)
                                err(1, "getaddrinfo udp: %s", gai_strerror(ecode));
                        nconf_udp = getnetconfigent("udp");
                        if (nconf_udp == NULL)
                                err(1, "getnetconfigent udp failed");
                        nb_udp.buf = ai_udp->ai_addr;
                        nb_udp.len = nb_udp.maxlen = ai_udp->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_udp, &nb_udp)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_udp, &nb_udp)))
                                err(1, "rpcb_set udp failed");
                        freeaddrinfo(ai_udp);
                }
                if (udpflag && ip6flag) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp6);
                        if (ecode != 0)
                                err(1, "getaddrinfo udp6: %s", gai_strerror(ecode));
                        nconf_udp6 = getnetconfigent("udp6");
                        if (nconf_udp6 == NULL)
                                err(1, "getnetconfigent udp6 failed");
                        nb_udp6.buf = ai_udp6->ai_addr;
                        nb_udp6.len = nb_udp6.maxlen = ai_udp6->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_udp6, &nb_udp6)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_udp6, &nb_udp6)))
                                err(1, "rpcb_set udp6 failed");
                        freeaddrinfo(ai_udp6);
                }
                if (tcpflag) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp);
                        if (ecode != 0)
                                err(1, "getaddrinfo tcp: %s", gai_strerror(ecode));
                        nconf_tcp = getnetconfigent("tcp");
                        if (nconf_tcp == NULL)
                                err(1, "getnetconfigent tcp failed");
                        nb_tcp.buf = ai_tcp->ai_addr;
                        nb_tcp.len = nb_tcp.maxlen = ai_tcp->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_tcp, &nb_tcp)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_tcp, &nb_tcp)))
                                err(1, "rpcb_set tcp failed");
                        freeaddrinfo(ai_tcp);
                }
                if (tcpflag && ip6flag) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp6);
                        if (ecode != 0)
                                err(1, "getaddrinfo tcp6: %s", gai_strerror(ecode));
                        nconf_tcp6 = getnetconfigent("tcp6");
                        if (nconf_tcp6 == NULL)
                                err(1, "getnetconfigent tcp6 failed");
                        nb_tcp6.buf = ai_tcp6->ai_addr;
                        nb_tcp6.len = nb_tcp6.maxlen = ai_tcp6->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_tcp6, &nb_tcp6)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_tcp6, &nb_tcp6)))
                                err(1, "rpcb_set tcp6 failed");
                        freeaddrinfo(ai_tcp6);
                }
                exit (0);
        }
        signal(SIGSYS, nonfs);
        signal(SIGCHLD, reapchild);

        openlog("nfsd", LOG_PID, LOG_DAEMON);

        /* If we use UDP only, we start the last server below. */
        srvcnt = tcpflag ? nfsdcnt : nfsdcnt - 1;
        for (i = 0; i < srvcnt; i++) {
                switch ((pid = fork())) {
                case -1:
                        syslog(LOG_ERR, "fork: %m");
                        nfsd_exit(1);
                case 0:
                        break;
                default:
                        children[i] = pid;
                        continue;
                }
                signal(SIGUSR1, child_cleanup);
                setproctitle("server");

                start_server(0);
        }

        signal(SIGUSR1, cleanup);
        FD_ZERO(&v4bits);
        FD_ZERO(&v6bits);
        FD_ZERO(&sockbits);

        rpcbregcnt = 0;
        /* Set up the socket for udp and rpcb register it. */
        if (udpflag) {
                rpcbreg = 0;
                for (i = 0; i < bindhostc; i++) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        if (setbindhost(&ai_udp, bindhost[i], hints) == 0) {
                                rpcbreg = 1;
                                rpcbregcnt++;
                                if ((sock = socket(ai_udp->ai_family,
                                    ai_udp->ai_socktype,
                                    ai_udp->ai_protocol)) < 0) {
                                        syslog(LOG_ERR,
                                            "can't create udp socket");
                                        nfsd_exit(1);
                                }
                                if (bind(sock, ai_udp->ai_addr,
                                    ai_udp->ai_addrlen) < 0) {
                                        syslog(LOG_ERR,
                                            "can't bind udp addr %s: %m",
                                            bindhost[i]);
                                        nfsd_exit(1);
                                }
                                freeaddrinfo(ai_udp);
                                nfsdargs.sock = sock;
                                nfsdargs.name = NULL;
                                nfsdargs.namelen = 0;
                                if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
                                        syslog(LOG_ERR, "can't Add UDP socket");
                                        nfsd_exit(1);
                                }
                                close(sock);
                        }
                }
                if (rpcbreg == 1) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp);
                        if (ecode != 0) {
                                syslog(LOG_ERR, "getaddrinfo udp: %s",
                                   gai_strerror(ecode));
                                nfsd_exit(1);
                        }
                        nconf_udp = getnetconfigent("udp");
                        if (nconf_udp == NULL)
                                err(1, "getnetconfigent udp failed");
                        nb_udp.buf = ai_udp->ai_addr;
                        nb_udp.len = nb_udp.maxlen = ai_udp->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_udp, &nb_udp)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_udp, &nb_udp)))
                                err(1, "rpcb_set udp failed");
                        freeaddrinfo(ai_udp);
                }
        }

        /* Set up the socket for udp6 and rpcb register it. */
        if (udpflag && ip6flag) {
                rpcbreg = 0;
                for (i = 0; i < bindhostc; i++) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        if (setbindhost(&ai_udp6, bindhost[i], hints) == 0) {
                                rpcbreg = 1;
                                rpcbregcnt++;
                                if ((sock = socket(ai_udp6->ai_family,
                                    ai_udp6->ai_socktype,
                                    ai_udp6->ai_protocol)) < 0) {
                                        syslog(LOG_ERR,
                                                "can't create udp6 socket");
                                        nfsd_exit(1);
                                }
                                if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
                                    &on, sizeof on) < 0) {
                                        syslog(LOG_ERR,
                                            "can't set v6-only binding for "
                                            "udp6 socket: %m");
                                        nfsd_exit(1);
                                }
                                if (bind(sock, ai_udp6->ai_addr,
                                    ai_udp6->ai_addrlen) < 0) {
                                        syslog(LOG_ERR,
                                            "can't bind udp6 addr %s: %m",
                                            bindhost[i]);
                                        nfsd_exit(1);
                                }
                                freeaddrinfo(ai_udp6);
                                nfsdargs.sock = sock;
                                nfsdargs.name = NULL;
                                nfsdargs.namelen = 0;
                                if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) < 0) {
                                        syslog(LOG_ERR,
                                            "can't add UDP6 socket");
                                        nfsd_exit(1);
                                }
                                close(sock);
                        }
                }
                if (rpcbreg == 1) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_DGRAM;
                        hints.ai_protocol = IPPROTO_UDP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_udp6);
                        if (ecode != 0) {
                                syslog(LOG_ERR, "getaddrinfo udp6: %s",
                                   gai_strerror(ecode));
                                nfsd_exit(1);
                        }
                        nconf_udp6 = getnetconfigent("udp6");
                        if (nconf_udp6 == NULL)
                                err(1, "getnetconfigent udp6 failed");
                        nb_udp6.buf = ai_udp6->ai_addr;
                        nb_udp6.len = nb_udp6.maxlen = ai_udp6->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_udp6, &nb_udp6)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_udp6, &nb_udp6)))
                                err(1, "rpcb_set udp6 failed");
                        freeaddrinfo(ai_udp6);
                }
        }

        /* Set up the socket for tcp and rpcb register it. */
        if (tcpflag) {
                rpcbreg = 0;
                for (i = 0; i < bindhostc; i++) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        if (setbindhost(&ai_tcp, bindhost[i], hints) == 0) {
                                rpcbreg = 1;
                                rpcbregcnt++;
                                if ((tcpsock = socket(AF_INET, SOCK_STREAM,
                                    0)) < 0) {
                                        syslog(LOG_ERR,
                                            "can't create tpc socket");
                                        nfsd_exit(1);
                                }
                                if (setsockopt(tcpsock, SOL_SOCKET,
                                    SO_REUSEADDR,
                                    (char *)&on, sizeof(on)) < 0)
                                        syslog(LOG_ERR,
                                             "setsockopt SO_REUSEADDR: %m");
                                if (bind(tcpsock, ai_tcp->ai_addr,
                                    ai_tcp->ai_addrlen) < 0) {
                                        syslog(LOG_ERR,
                                            "can't bind tcp addr %s: %m",
                                            bindhost[i]);
                                        nfsd_exit(1);
                                }
                                if (listen(tcpsock, 64) < 0) {
                                        syslog(LOG_ERR, "listen failed");
                                        nfsd_exit(1);
                                }
                                freeaddrinfo(ai_tcp);
                                FD_SET(tcpsock, &sockbits);
                                FD_SET(tcpsock, &v4bits);
                                maxsock = tcpsock;
                                connect_type_cnt++;
                        }
                }
                if (rpcbreg == 1) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        ecode = getaddrinfo(NULL, "nfs", &hints,
                             &ai_tcp);
                        if (ecode != 0) {
                                syslog(LOG_ERR, "getaddrinfo tcp: %s",
                                   gai_strerror(ecode));
                                nfsd_exit(1);
                        }
                        nconf_tcp = getnetconfigent("tcp");
                        if (nconf_tcp == NULL)
                                err(1, "getnetconfigent tcp failed");
                        nb_tcp.buf = ai_tcp->ai_addr;
                        nb_tcp.len = nb_tcp.maxlen = ai_tcp->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_tcp,
                            &nb_tcp)) || (!rpcb_set(RPCPROG_NFS, 3,
                            nconf_tcp, &nb_tcp)))
                                err(1, "rpcb_set tcp failed");
                        freeaddrinfo(ai_tcp);
                }
        }

        /* Set up the socket for tcp6 and rpcb register it. */
        if (tcpflag && ip6flag) {
                rpcbreg = 0;
                for (i = 0; i < bindhostc; i++) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        if (setbindhost(&ai_tcp6, bindhost[i], hints) == 0) {
                                rpcbreg = 1;
                                rpcbregcnt++;
                                if ((tcp6sock = socket(ai_tcp6->ai_family,
                                    ai_tcp6->ai_socktype,
                                    ai_tcp6->ai_protocol)) < 0) {
                                        syslog(LOG_ERR,
                                            "can't create tcp6 socket");
                                        nfsd_exit(1);
                                }
                                if (setsockopt(tcp6sock, SOL_SOCKET,
                                    SO_REUSEADDR,
                                    (char *)&on, sizeof(on)) < 0)
                                        syslog(LOG_ERR,
                                            "setsockopt SO_REUSEADDR: %m");
                                if (setsockopt(tcp6sock, IPPROTO_IPV6,
                                    IPV6_V6ONLY, &on, sizeof on) < 0) {
                                        syslog(LOG_ERR,
                                        "can't set v6-only binding for tcp6 "
                                            "socket: %m");
                                        nfsd_exit(1);
                                }
                                if (bind(tcp6sock, ai_tcp6->ai_addr,
                                    ai_tcp6->ai_addrlen) < 0) {
                                        syslog(LOG_ERR,
                                            "can't bind tcp6 addr %s: %m",
                                            bindhost[i]);
                                        nfsd_exit(1);
                                }
                                if (listen(tcp6sock, 64) < 0) {
                                        syslog(LOG_ERR, "listen failed");
                                        nfsd_exit(1);
                                }
                                freeaddrinfo(ai_tcp6);
                                FD_SET(tcp6sock, &sockbits);
                                FD_SET(tcp6sock, &v6bits);
                                if (maxsock < tcp6sock)
                                        maxsock = tcp6sock;
                                connect_type_cnt++;
                        }
                }
                if (rpcbreg == 1) {
                        memset(&hints, 0, sizeof hints);
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_protocol = IPPROTO_TCP;
                        ecode = getaddrinfo(NULL, "nfs", &hints, &ai_tcp6);
                        if (ecode != 0) {
                                syslog(LOG_ERR, "getaddrinfo tcp6: %s",
                                   gai_strerror(ecode));
                                nfsd_exit(1);
                        }
                        nconf_tcp6 = getnetconfigent("tcp6");
                        if (nconf_tcp6 == NULL)
                                err(1, "getnetconfigent tcp6 failed");
                        nb_tcp6.buf = ai_tcp6->ai_addr;
                        nb_tcp6.len = nb_tcp6.maxlen = ai_tcp6->ai_addrlen;
                        if ((!rpcb_set(RPCPROG_NFS, 2, nconf_tcp6, &nb_tcp6)) ||
                            (!rpcb_set(RPCPROG_NFS, 3, nconf_tcp6, &nb_tcp6)))
                                err(1, "rpcb_set tcp6 failed");
                        freeaddrinfo(ai_tcp6);
                }
        }

        if (rpcbregcnt == 0) {
                syslog(LOG_ERR, "rpcb_set() failed, nothing to do: %m");
                nfsd_exit(1);
        }

        if (tcpflag && connect_type_cnt == 0) {
                syslog(LOG_ERR, "tcp connects == 0, nothing to do: %m");
                nfsd_exit(1);
        }

        setproctitle("master");
        /*
         * We always want a master to have a clean way to to shut nfsd down
         * (with unregistration): if the master is killed, it unregisters and
         * kills all children. If we run for UDP only (and so do not have to
         * loop waiting waiting for accept), we instead make the parent
         * a "server" too. start_server will not return.
         */
        if (!tcpflag)
                start_server(1);

        /*
         * Loop forever accepting connections and passing the sockets
         * into the kernel for the mounts.
         */
        for (;;) {
                ready = sockbits;
                if (connect_type_cnt > 1) {
                        if (select(maxsock + 1,
                            &ready, NULL, NULL, NULL) < 1) {
                                syslog(LOG_ERR, "select failed: %m");
                                if (errno == EINTR)
                                        continue;
                                nfsd_exit(1);
                        }
                }
                for (tcpsock = 0; tcpsock <= maxsock; tcpsock++) {
                        if (FD_ISSET(tcpsock, &ready)) {
                                if (FD_ISSET(tcpsock, &v4bits)) {
                                        len = sizeof(inetpeer);
                                        if ((msgsock = accept(tcpsock,
                                            (struct sockaddr *)&inetpeer, &len)) < 0) {
                                                syslog(LOG_ERR, "accept failed: %m");
                                                if (errno == ECONNABORTED ||
                                                    errno == EINTR)
                                                        continue;
                                                nfsd_exit(1);
                                        }
                                        memset(inetpeer.sin_zero, 0,
                                                sizeof(inetpeer.sin_zero));
                                        if (setsockopt(msgsock, SOL_SOCKET,
                                            SO_KEEPALIVE, (char *)&on, sizeof(on)) < 0)
                                                syslog(LOG_ERR,
                                                    "setsockopt SO_KEEPALIVE: %m");
                                        nfsdargs.sock = msgsock;
                                        nfsdargs.name = (caddr_t)&inetpeer;
                                        nfsdargs.namelen = len;
                                        nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
                                        close(msgsock);
                                } else if (FD_ISSET(tcpsock, &v6bits)) {
                                        len = sizeof(inet6peer);
                                        if ((msgsock = accept(tcpsock,
                                            (struct sockaddr *)&inet6peer,
                                            &len)) < 0) {
                                                syslog(LOG_ERR,
                                                     "accept failed: %m");
                                                if (errno == ECONNABORTED ||
                                                    errno == EINTR)
                                                        continue;
                                                nfsd_exit(1);
                                        }
                                        if (setsockopt(msgsock, SOL_SOCKET,
                                            SO_KEEPALIVE, (char *)&on,
                                            sizeof(on)) < 0)
                                                syslog(LOG_ERR, "setsockopt "
                                                    "SO_KEEPALIVE: %m");
                                        nfsdargs.sock = msgsock;
                                        nfsdargs.name = (caddr_t)&inet6peer;
                                        nfsdargs.namelen = len;
                                        nfssvc(NFSSVC_ADDSOCK, &nfsdargs);
                                        close(msgsock);
                                }
                        }
                }
        }
}

int
setbindhost(struct addrinfo **ai, const char *bindhost, struct addrinfo hints)
{
        int ecode;
        u_int32_t host_addr[4];  /* IPv4 or IPv6 */
        const char *hostptr;

        if (bindhost == NULL || strcmp("*", bindhost) == 0)
                hostptr = NULL;
        else
                hostptr = bindhost;

        if (hostptr != NULL) {
                switch (hints.ai_family) {
                case AF_INET:
                        if (inet_pton(AF_INET, hostptr, host_addr) == 1) {
                                hints.ai_flags = AI_NUMERICHOST;
                        } else {
                                if (inet_pton(AF_INET6, hostptr,
                                    host_addr) == 1)
                                        return (1);
                        }
                        break;
                case AF_INET6:
                        if (inet_pton(AF_INET6, hostptr, host_addr) == 1) {
                                hints.ai_flags = AI_NUMERICHOST;
                        } else {
                                if (inet_pton(AF_INET, hostptr,
                                    host_addr) == 1)
                                        return (1);
                        }
                        break;
                default:
                        break;
                }
        }

        ecode = getaddrinfo(hostptr, "nfs", &hints, ai);
        if (ecode != 0) {
                syslog(LOG_ERR, "getaddrinfo %s: %s", bindhost,
                    gai_strerror(ecode));
                return (1);
        }
        return (0);
}

void
usage(void)
{
        fprintf(stderr, "usage: nfsd %s\n", USAGE);
        exit(1);
}

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

void
reapchild(int signo __unused)
{
        pid_t pid;
        int i;

        while ((pid = wait3(NULL, WNOHANG, NULL)) > 0) {
                for (i = 0; i < nfsdcnt; i++)
                        if (pid == children[i])
                                children[i] = -1;
        }
}

void
unregistration(void)
{
        if ((!rpcb_unset(RPCPROG_NFS, 2, NULL)) ||
            (!rpcb_unset(RPCPROG_NFS, 3, NULL)))
                syslog(LOG_ERR, "rpcb_unset failed");
}

void
killchildren(void)
{
        int i;

        for (i = 0; i < nfsdcnt; i++) {
                if (children[i] > 0)
                        kill(children[i], SIGKILL);
        }
}

/*
 * Cleanup master after SIGUSR1.
 */
void
cleanup(__unused int signo)
{
        nfsd_exit(0);
}

/*
 * Cleanup child after SIGUSR1.
 */
void
child_cleanup(__unused int signo)
{
        exit(0);
}

void
nfsd_exit(int status)
{
        killchildren();
        unregistration();
        exit(status);
}

void
start_server(int master)
{
        int status;

        status = 0;
        nsd.nsd_nfsd = NULL;
        if (nfssvc(NFSSVC_NFSD, &nsd) < 0) {
                syslog(LOG_ERR, "nfssvc: %m");
                status = 1;
        }
        if (master)
                nfsd_exit(status);
        else
                exit(status);
}