/*      $OpenBSD: nfsd.c,v 1.48 2026/03/27 19:19:41 bluhm Exp $ */
/*      $NetBSD: nfsd.c,v 1.19 1996/02/18 23:18:56 mycroft Exp $        */

/*
 * 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.
 */

#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/uio.h>
#include <sys/ucred.h>
#include <sys/mount.h>
#include <sys/socket.h>

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

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

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

/* Global defs */
#ifdef DEBUG
#define syslog(e, s, ...)                       \
do {                                            \
        fprintf(stderr, (s), ##__VA_ARGS__);    \
        fprintf(stderr, "\n");                  \
} while (0)
int     debug = 1;
#else
int     debug = 0;
#endif

struct  nfsd_srvargs nsd;

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

#define MAXNFSDCNT      20
#define DEFNFSDCNT       4

/*
 * 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 portmap
 *
 * 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 portmapper
 *      -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 sockaddr_in inetaddr;
        int ch, i;
        int nfsdcnt = DEFNFSDCNT, on, reregister = 0, sock;
        int udpflag = 0, tcpflag = 0, tcpsock;
        const char *errstr = NULL;

        /* Start by writing to both console and log. */
        openlog("nfsd", LOG_PID | LOG_PERROR, LOG_DAEMON);

        while ((ch = getopt(argc, argv, "n:rtu")) != -1)
                switch (ch) {
                case 'n':
                        nfsdcnt = strtonum(optarg, 1, MAXNFSDCNT, &errstr);
                        if (errstr) {
                                syslog(LOG_ERR, "nfsd count is %s: %s", errstr, optarg);
                                return(1);
                        }
                        break;
                case 'r':
                        reregister = 1;
                        break;
                case 't':
                        tcpflag = 1;
                        break;
                case 'u':
                        udpflag = 1;
                        break;
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;

        if (!(tcpflag || udpflag))
                udpflag = 1;

        /*
         * XXX
         * Backward compatibility, trailing number is the count of daemons.
         */
        if (argc > 1)
                usage();
        if (argc == 1) {
                nfsdcnt = strtonum(argv[0], 1, MAXNFSDCNT, &errstr);
                if (errstr) {
                        syslog(LOG_ERR, "nfsd count is %s: %s", errstr, optarg);
                        return(1);
                }
        }

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

        if (unveil("/", "") == -1) {
                syslog(LOG_ERR, "unveil /: %s", strerror(errno));
                return (1);
        }
        if (unveil(NULL, NULL) == -1) {
                syslog(LOG_ERR, "unveil: %s", strerror(errno));
                return (1);
        }

        if (reregister) {
                if (udpflag &&
                    (!pmap_set(RPCPROG_NFS, 2, IPPROTO_UDP, NFS_PORT) ||
                     !pmap_set(RPCPROG_NFS, 3, IPPROTO_UDP, NFS_PORT))) {
                        syslog(LOG_ERR, "can't register with portmap for UDP (%s).",
                            strerror(errno));
                        return (1);
                }
                if (tcpflag &&
                    (!pmap_set(RPCPROG_NFS, 2, IPPROTO_TCP, NFS_PORT) ||
                     !pmap_set(RPCPROG_NFS, 3, IPPROTO_TCP, NFS_PORT))) {
                        syslog(LOG_ERR, "can't register with portmap for TCP (%s).",
                            strerror(errno));
                        return (1);
                }
                return (0);
        }

        /* Cut back to writing to log only. */
        closelog();
        openlog("nfsd", LOG_PID, LOG_DAEMON);

        for (i = 0; i < nfsdcnt; i++) {
                switch (fork()) {
                case -1:
                        syslog(LOG_ERR, "fork: %s", strerror(errno));
                        return (1);
                case 0:
                        break;
                default:
                        continue;
                }

                setproctitle("server");
                nsd.nsd_nfsd = NULL;
                if (nfssvc(NFSSVC_NFSD, &nsd) == -1) {
                        syslog(LOG_ERR, "nfssvc: %s", strerror(errno));
                        return (1);
                }
                return (0);
        }

        /* If we are serving udp, set up the socket. */
        if (udpflag) {
                if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
                        syslog(LOG_ERR, "can't create udp socket");
                        return (1);
                }
                memset(&inetaddr, 0, sizeof inetaddr);
                inetaddr.sin_family = AF_INET;
                inetaddr.sin_addr.s_addr = INADDR_ANY;
                inetaddr.sin_port = htons(NFS_PORT);
                inetaddr.sin_len = sizeof(inetaddr);
                if (bind(sock, (struct sockaddr *)&inetaddr,
                    sizeof(inetaddr)) == -1) {
                        syslog(LOG_ERR, "can't bind udp addr");
                        return (1);
                }
                if (!pmap_set(RPCPROG_NFS, 2, IPPROTO_UDP, NFS_PORT) ||
                    !pmap_set(RPCPROG_NFS, 3, IPPROTO_UDP, NFS_PORT)) {
                        syslog(LOG_ERR, "can't register with udp portmap");
                        return (1);
                }
                nfsdargs.sock = sock;
                nfsdargs.name = NULL;
                nfsdargs.namelen = 0;
                if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) == -1) {
                        syslog(LOG_ERR, "can't Add UDP socket");
                        return (1);
                }
                (void)close(sock);
        }

        /* Now set up the master server socket waiting for tcp connections. */
        on = 1;
        if (!tcpflag)
                return (0);

        if ((tcpsock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                syslog(LOG_ERR, "can't create tcp socket");
                return (1);
        }
        if (setsockopt(tcpsock,
            SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
                syslog(LOG_ERR, "setsockopt SO_REUSEADDR: %s", strerror(errno));
        memset(&inetaddr, 0, sizeof inetaddr);
        inetaddr.sin_family = AF_INET;
        inetaddr.sin_addr.s_addr = INADDR_ANY;
        inetaddr.sin_port = htons(NFS_PORT);
        inetaddr.sin_len = sizeof(inetaddr);
        if (bind(tcpsock, (struct sockaddr *)&inetaddr,
            sizeof (inetaddr)) == -1) {
                syslog(LOG_ERR, "can't bind tcp addr");
                return (1);
        }
        if (listen(tcpsock, 5) == -1) {
                syslog(LOG_ERR, "listen failed");
                return (1);
        }
        if (!pmap_set(RPCPROG_NFS, 2, IPPROTO_TCP, NFS_PORT) ||
            !pmap_set(RPCPROG_NFS, 3, IPPROTO_TCP, NFS_PORT)) {
                syslog(LOG_ERR, "can't register tcp with portmap");
                return (1);
        }

        setproctitle("master");

        /*
         * Loop forever accepting connections and passing the sockets
         * into the kernel for the mounts.
         */
        for (;;) {
                struct sockaddr_in      inetpeer;
                int msgsock;
                socklen_t len = sizeof(inetpeer);

                if ((msgsock = accept(tcpsock,
                    (struct sockaddr *)&inetpeer, &len)) == -1) {
                        if (errno == EWOULDBLOCK || errno == EINTR ||
                            errno == ECONNABORTED)
                                continue;
                        syslog(LOG_ERR, "accept failed: %s", strerror(errno));
                        return (1);
                }
                memset(inetpeer.sin_zero, 0, sizeof(inetpeer.sin_zero));
                if (setsockopt(msgsock, SOL_SOCKET,
                    SO_KEEPALIVE, &on, sizeof(on)) == -1)
                        syslog(LOG_ERR,
                            "setsockopt SO_KEEPALIVE: %s", strerror(errno));
                nfsdargs.sock = msgsock;
                nfsdargs.name = (caddr_t)&inetpeer;
                nfsdargs.namelen = len;
                if (nfssvc(NFSSVC_ADDSOCK, &nfsdargs) == -1) {
                        syslog(LOG_ERR, "can't Add TCP socket");
                }
                (void)close(msgsock);
        }
}

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

void
nonfs(int signo)
{
        int save_errno = errno;
        struct syslog_data sdata = SYSLOG_DATA_INIT;

        syslog_r(LOG_ERR, &sdata, "missing system call: NFS not available.");
        errno = save_errno;
}

void
reapchild(int signo)
{
        int save_errno = errno;

        while (wait3(NULL, WNOHANG, NULL) > 0)
                continue;
        errno = save_errno;
}