/*
 * Copyright (c) 2011-2015 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@dragonflybsd.org>
 * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
 *
 * 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 DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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/mount.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <vfs/hammer2/hammer2_mount.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <dmsg.h>
#include <mntopts.h>

static int cluster_connect(const char *volume);
static void usage(const char *ctl, ...);

static struct mntopt mopts[] = {
        MOPT_STDOPTS,
        MOPT_UPDATE,
        { "local", 0, HMNT2_LOCAL, 1 },
        MOPT_NULL
};

/*
 * Usage: mount_hammer2 [volume] [mtpt]
 */
int
main(int ac, char *av[])
{
        struct hammer2_mount_info info;
        struct vfsconf vfc;
        char *mountpt;
        char *devpath;
        int error;
        int ch;
        int mount_flags;
        int init_flags;

        bzero(&info, sizeof(info));
        mount_flags = 0;
        init_flags = 0;

        while ((ch = getopt(ac, av, "o:u")) != -1) {
                switch(ch) {
                case 'o':
                        getmntopts(optarg, mopts, &mount_flags, &info.hflags);
                        break;
                case 'u':
                        init_flags |= MNT_UPDATE;
                        break;
                default:
                        usage("unknown option: -%c", ch);
                        /* not reached */
                }
        }
        ac -= optind;
        av += optind;
        mount_flags |= init_flags;

        error = getvfsbyname("hammer2", &vfc);
        if (error) {
                fprintf(stderr, "hammer2 vfs not loaded\n");
                exit(1);
        }

        /*
         * Only the mount point need be specified in update mode.
         */
        if (init_flags & MNT_UPDATE) {
                if (ac != 1) {
                        usage("missing parameter (node)");
                        /* not reached */
                }
                mountpt = av[0];
                if (mount(vfc.vfc_name, mountpt, mount_flags, &info))
                        usage("mount %s: %s", mountpt, strerror(errno));
                exit(0);
        }

        /*
         * New mount
         */
        if (ac != 2) {
                usage("missing parameter(s) (special[@label] node)");
                /* not reached */
        }

        devpath = strdup(av[0]);
        mountpt = av[1];

        if (devpath[0] == 0) {
                fprintf(stderr, "mount_hammer2: empty device path\n");
                exit(1);
        }

        /*
         * Automatically add @BOOT, @ROOT, or @DATA if no label specified,
         * based on the slice.
         */
        if (strchr(devpath, '@') == NULL) {
                char slice = devpath[strlen(devpath)-1];
                switch(slice) {
                case 'a':
                        asprintf(&devpath, "%s@BOOT", devpath);
                        break;
                case 'd':
                        asprintf(&devpath, "%s@ROOT", devpath);
                        break;
                default:
                        asprintf(&devpath, "%s@DATA", devpath);
                        break;
                }
        }

        /*
         * Connect to the cluster controller.  This handles both remote
         * mounts and device cache/master/slave mounts.
         *
         * When doing remote mounts that are allowed to run in the background
         * the mount program will fork, detach, print a message, and exit(0)
         * the originator while retrying in the background.
         *
         * Don't exit on failure, this isn't likely going to work for
         * the root [re]mount in early boot.
         */
        info.cluster_fd = cluster_connect(devpath);
        if (info.cluster_fd < 0) {
                fprintf(stderr,
                        "mount_hammer2: cluster_connect(%s) failed\n",
                        devpath);
        }

        /*
         * Try to mount it, prefix if necessary.
         */
        if (!strchr(devpath, ':') && devpath[0] != '/' && devpath[0] != '@') {
                char *p2;
                asprintf(&p2, "/dev/%s", devpath);
                free(devpath);
                devpath = p2;
        }
        info.volume = devpath;

        error = mount(vfc.vfc_name, mountpt, mount_flags, &info);
        if (error < 0) {
                if (errno == ERANGE) {
                        fprintf(stderr,
                                "mount_hammer2: %s integrated with %s\n",
                                info.volume, mountpt);
                } else if (errno == ENOENT) {
                        fprintf(stderr, "mount_hammer2: %s not found\n",
                                info.volume);
                } else if (errno == ENXIO) {
                        fprintf(stderr, "mount_hammer2: incorrect volume "
                                "specification %s\n",
                                info.volume);
                } else {
                        perror("mount");
                }
                exit(1);
        }
        free(devpath);

        /*
         * XXX fork a backgrounded reconnector process to handle connection
         *     failures.
         */

        return (0);
}

/*
 * Connect to the cluster controller.  We can connect to a local or remote
 * cluster controller, depending.  For a multi-node cluster we always want
 * to connect to the local controller and let it maintain the connections
 * to the multiple remote nodes.
 */
static
int
cluster_connect(const char *volume __unused)
{
        struct sockaddr_in lsin;
        int fd;

        /*
         * This starts the hammer2 service if it isn't already running,
         * so we can connect to it.
         */
        system("/sbin/hammer2 -q service");

        /*
         * Connect us to the service but leave the rest to the kernel.
         * If the connection is lost during the mount
         */
        if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
                perror("socket");
                return(-1);
        }
        bzero(&lsin, sizeof(lsin));
        lsin.sin_family = AF_INET;
        lsin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        lsin.sin_port = htons(DMSG_LISTEN_PORT);

        if (connect(fd, (struct sockaddr *)&lsin, sizeof(lsin)) < 0) {
                close(fd);
                fprintf(stderr, "mount_hammer2: unable to connect to "
                                "cluster controller\n");
                return(-1);
        }

        return(fd);
}

static
void
usage(const char *ctl, ...)
{
        va_list va;

        va_start(va, ctl);
        fprintf(stderr, "mount_hammer2: ");
        vfprintf(stderr, ctl, va);
        va_end(va);
        fprintf(stderr, "\n");
        fprintf(stderr, " mount_hammer2 [-o options] special[@label] node\n");
        fprintf(stderr, " mount_hammer2 [-o options] @label node\n");
        fprintf(stderr, " mount_hammer2 -u [-o options] node\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "options:\n"
                        " <standard_mount_options>\n"
                        " local\t- disable PFS clustering for whole device\n"
        );
        exit(1);
}