/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999 Martin Blapp
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/param.h>
#include <sys/ucred.h>
#include <sys/mount.h>

#include <rpc/rpc.h>
#include <rpcsvc/mount.h>

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

#include "mounttab.h"

int verbose;

static int do_umount (char *, char *);
static int do_umntall (char *);
static int is_mounted (char *, char *);
static void usage (void);
int     xdr_dir (XDR *, char *);

int
main(int argc, char **argv) {
        int ch, keep, success, pathlen;
        time_t expire, now;
        char *host, *path;
        struct mtablist *mtab;

        expire = 0;
        host = path = NULL;
        success = keep = verbose = 0;
        while ((ch = getopt(argc, argv, "h:kp:ve:")) != -1)
                switch (ch) {
                case 'h':
                        host = optarg;
                        break;
                case 'e':
                        expire = atoi(optarg);
                        break;
                case 'k':
                        keep = 1;
                        break;
                case 'p':
                        path = optarg;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                case '?':
                        usage();
                default:
                        break;
                }
        argc -= optind;
        argv += optind;

        /* Default expiretime is one day */
        if (expire == 0)
                expire = 86400;
        time(&now);

        /* Read PATH_MOUNTTAB. */
        if (!read_mtab()) {
                if (verbose)
                        warnx("no mounttab entries (%s does not exist)",
                            PATH_MOUNTTAB);
                mtabhead = NULL;
        }

        if (host == NULL && path == NULL) {
                /* Check each entry and do any necessary unmount RPCs. */
                for (mtab = mtabhead; mtab != NULL; mtab = mtab->mtab_next) {
                        if (*mtab->mtab_host == '\0')
                                continue;
                        if (mtab->mtab_time + expire < now) {
                                /* Clear expired entry. */
                                if (verbose)
                                        warnx("remove expired entry %s:%s",
                                            mtab->mtab_host, mtab->mtab_dirp);
                                bzero(mtab->mtab_host,
                                    sizeof(mtab->mtab_host));
                                continue;
                        }
                        if (keep && is_mounted(mtab->mtab_host,
                            mtab->mtab_dirp)) {
                                if (verbose)
                                        warnx("skip entry %s:%s",
                                            mtab->mtab_host, mtab->mtab_dirp);
                                continue;
                        }
                        if (do_umount(mtab->mtab_host, mtab->mtab_dirp)) {
                                if (verbose)
                                        warnx("umount RPC for %s:%s succeeded",
                                            mtab->mtab_host, mtab->mtab_dirp);
                                /* Remove all entries for this host + path. */
                                clean_mtab(mtab->mtab_host, mtab->mtab_dirp,
                                    verbose);
                        }
                }
                success = 1;
        } else {
                if (host == NULL && path != NULL)
                        /* Missing hostname. */
                        usage();
                if (path == NULL) {
                        /* Do a RPC UMNTALL for this specific host */
                        success = do_umntall(host);
                        if (verbose && success)
                                warnx("umntall RPC for %s succeeded", host);
                } else {
                        /* Do a RPC UMNTALL for this specific mount */
                        for (pathlen = strlen(path);
                            pathlen > 1 && path[pathlen - 1] == '/'; pathlen--)
                                path[pathlen - 1] = '\0';
                        success = do_umount(host, path);
                        if (verbose && success)
                                warnx("umount RPC for %s:%s succeeded", host,
                                    path);
                }
                /* If successful, remove any corresponding mounttab entries. */
                if (success)
                        clean_mtab(host, path, verbose);
        }
        /* Write and unlink PATH_MOUNTTAB if necessary */
        if (success)
                success = write_mtab(verbose);
        free_mtab();
        exit (success ? 0 : 1);
}

/*
 * Send a RPC_MNT UMNTALL request to hostname.
 * XXX This works for all mountd implementations,
 * but produces a RPC IOERR on non FreeBSD systems.
 */
int
do_umntall(char *hostname) {
        enum clnt_stat clnt_stat;
        struct timeval try;
        CLIENT *clp;

        try.tv_sec = 3;
        try.tv_usec = 0;
        clp = clnt_create_timed(hostname, MOUNTPROG, MOUNTVERS, "udp",
            &try);
        if (clp == NULL) {
                warnx("%s: %s", hostname, clnt_spcreateerror("MOUNTPROG"));
                return (0);
        }
        clp->cl_auth = authunix_create_default();
        clnt_stat = clnt_call(clp, MOUNTPROC_UMNTALL,
            (xdrproc_t)xdr_void, (caddr_t)0,
            (xdrproc_t)xdr_void, (caddr_t)0, try);
        if (clnt_stat != RPC_SUCCESS)
                warnx("%s: %s", hostname, clnt_sperror(clp, "MOUNTPROC_UMNTALL"));
        auth_destroy(clp->cl_auth);
        clnt_destroy(clp);
        return (clnt_stat == RPC_SUCCESS);
}

/*
 * Send a RPC_MNT UMOUNT request for dirp to hostname.
 */
int
do_umount(char *hostname, char *dirp) {
        enum clnt_stat clnt_stat;
        struct timeval try;
        CLIENT *clp;

        try.tv_sec = 3;
        try.tv_usec = 0;
        clp = clnt_create_timed(hostname, MOUNTPROG, MOUNTVERS, "udp",
            &try);
        if (clp  == NULL) {
                warnx("%s: %s", hostname, clnt_spcreateerror("MOUNTPROG"));
                return (0);
        }
        clp->cl_auth = authsys_create_default();
        clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir, dirp,
            (xdrproc_t)xdr_void, (caddr_t)0, try);
        if (clnt_stat != RPC_SUCCESS)
                warnx("%s: %s", hostname, clnt_sperror(clp, "MOUNTPROC_UMNT"));
        auth_destroy(clp->cl_auth);
        clnt_destroy(clp);
        return (clnt_stat == RPC_SUCCESS);
}

/*
 * Check if the entry is still/already mounted.
 */
int
is_mounted(char *hostname, char *dirp) {
        struct statfs *mntbuf;
        char name[MNAMELEN + 1];
        size_t bufsize;
        int mntsize, i;

        if (strlen(hostname) + strlen(dirp) >= MNAMELEN)
                return (0);
        snprintf(name, sizeof(name), "%s:%s", hostname, dirp);
        mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
        if (mntsize <= 0)
                return (0);
        bufsize = (mntsize + 1) * sizeof(struct statfs);
        if ((mntbuf = malloc(bufsize)) == NULL)
                err(1, "malloc");
        mntsize = getfsstat(mntbuf, (long)bufsize, MNT_NOWAIT);
        for (i = mntsize - 1; i >= 0; i--) {
                if (strcmp(mntbuf[i].f_mntfromname, name) == 0) {
                        free(mntbuf);
                        return (1);
                }
        }
        free(mntbuf);
        return (0);
}

/*
 * xdr routines for mount rpc's
 */
int
xdr_dir(XDR *xdrsp, char *dirp) {
        return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
}

static void
usage(void)
{
        (void)fprintf(stderr, "%s\n",
            "usage: rpc.umntall [-kv] [-e expire] [-h host] [-p path]");
        exit(1);
}