/*      $OpenBSD: rstatd.c,v 1.31 2023/03/08 04:43:05 guenther Exp $    */

/*-
 * Copyright (c) 1993, John Brezak
 * All rights reserved.
 *
 * 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. The name of the author may not 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/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <signal.h>
#include <pwd.h>
#include <syslog.h>
#include <errno.h>
#include <rpc/rpc.h>
#include <rpcsvc/rstat.h>

extern void rstat_service(struct svc_req *, SVCXPRT *);

void my_svc_run(void);

int from_inetd = 1;     /* started from inetd ? */
int closedown = 20;     /* how long to wait before going dormant */

volatile sig_atomic_t gotsig;

static void
getsig(int signo)
{
        gotsig = 1;
}


int
main(int argc, char *argv[])
{
        int sock = 0, proto = 0;
        socklen_t fromlen;
        struct passwd *pw;
        struct sockaddr_storage from;
        SVCXPRT *transp;

        openlog("rpc.rstatd", LOG_NDELAY|LOG_CONS|LOG_PID, LOG_DAEMON);

        if ((pw = getpwnam("_rstatd")) == NULL) {
                syslog(LOG_ERR, "no such user _rstatd");
                exit(1);
        }
        if (chroot("/var/empty") == -1) {
                syslog(LOG_ERR, "cannot chdir to /var/empty.");
                exit(1);
        }
        chdir("/");

        setgroups(1, &pw->pw_gid);
        setegid(pw->pw_gid);
        setgid(pw->pw_gid);
        seteuid(pw->pw_uid);
        setuid(pw->pw_uid);

        if (argc == 2)
                closedown = strtonum(argv[1], 1, INT_MAX, NULL);
        if (closedown == 0)
                closedown = 20;

        /*
         * See if inetd started us
         */
        fromlen = sizeof(from);
        if (getsockname(0, (struct sockaddr *)&from, &fromlen) == -1) {
                from_inetd = 0;
                sock = RPC_ANYSOCK;
                proto = IPPROTO_UDP;
        }

        if (!from_inetd) {
                daemon(0, 0);

                (void)pmap_unset(RSTATPROG, RSTATVERS_TIME);
                (void)pmap_unset(RSTATPROG, RSTATVERS_SWTCH);
                (void)pmap_unset(RSTATPROG, RSTATVERS_ORIG);

                (void) signal(SIGINT, getsig);
                (void) signal(SIGTERM, getsig);
                (void) signal(SIGHUP, getsig);
        }

        transp = svcudp_create(sock);
        if (transp == NULL) {
                syslog(LOG_ERR, "cannot create udp service.");
                exit(1);
        }
        if (!svc_register(transp, RSTATPROG, RSTATVERS_TIME, rstat_service, proto)) {
                syslog(LOG_ERR, "unable to register (RSTATPROG, RSTATVERS_TIME, udp).");
                exit(1);
        }
        if (!svc_register(transp, RSTATPROG, RSTATVERS_SWTCH, rstat_service, proto)) {
                syslog(LOG_ERR, "unable to register (RSTATPROG, RSTATVERS_SWTCH, udp).");
                exit(1);
        }
        if (!svc_register(transp, RSTATPROG, RSTATVERS_ORIG, rstat_service, proto)) {
                syslog(LOG_ERR, "unable to register (RSTATPROG, RSTATVERS_ORIG, udp).");
                exit(1);
        }

        my_svc_run();
        syslog(LOG_ERR, "svc_run returned");
        exit(1);
}

void
my_svc_run(void)
{
        extern volatile sig_atomic_t wantupdatestat;
        extern void updatestat(void);
        struct pollfd *pfd = NULL, *newp;
        int nready, saved_max_pollfd = 0;

        for (;;) {
                if (wantupdatestat) {
                        wantupdatestat = 0;
                        updatestat();
                }
                if (gotsig) {
                        (void) pmap_unset(RSTATPROG, RSTATVERS_TIME);
                        (void) pmap_unset(RSTATPROG, RSTATVERS_SWTCH);
                        (void) pmap_unset(RSTATPROG, RSTATVERS_ORIG);
                        exit(0);
                }
                if (svc_max_pollfd > saved_max_pollfd) {
                        newp = reallocarray(pfd, svc_max_pollfd, sizeof(*pfd));
                        if (newp == NULL) {
                                free(pfd);
                                perror("svc_run: - realloc failed");
                                return;
                        }
                        pfd = newp;
                        saved_max_pollfd = svc_max_pollfd;
                }
                memcpy(pfd, svc_pollfd, svc_max_pollfd * sizeof(*pfd));

                nready = poll(pfd, svc_max_pollfd, INFTIM);
                switch (nready) {
                case -1:
                        if (errno == EINTR)
                                continue;
                        perror("svc_run: - poll failed");
                        free(pfd);
                        return;
                case 0:
                        continue;
                default:
                        svc_getreq_poll(pfd, nready);
                }
        }
}