/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <locale.h>
#include <stdio.h>
#include <time.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/mount.h>
#include <sys/fs/pc_fs.h>
#include <fslib.h>

extern int      daylight;

static int roflag = 0;
static char optbuf[MAX_MNTOPT_STR] = { '\0', };
static int optsize = 0;


/*
 * Since the format/value expected for the mount options listed below
 * differs between what the user mount command expects and what the
 * kernel module can grok, we transmogrify the mount option string
 * for such options. Others are copied through as-is.
 */
static char *pcfs_opts[] = { MNTOPT_PCFS_TIMEZONE, NULL };
#define ARG_PCFS_TIMEZONE       0

/*
 * While constructing the mount option string, we need to append
 * comma separators if there have been previous options copied over
 * from the input string. This takes care of it.
 */
static int
append_opt(char *str, int strsz, char *opt)
{
        if (str[0] != '\0' && strlcat(str, ",", strsz) >= strsz)
                return (0);

        return (strlcat(str, opt, strsz) < strsz);
}

int
main(int argc, char *argv[])
{
        char *mnt_special;
        char *mnt_mountp;
        int c;
        char *myname;
        char typename[64];
        char tzstr[100];
        char *tzval;
        char *savedoptbuf = NULL, *savedoptarg = NULL;
        char *in_arg, *val, *curarg;
        extern int optind;
        extern char *optarg;
        int error = 0;
        int verbose = 0;
        int mflg = MS_OPTIONSTR;        /* we always pass mount options */
        int qflg = 0;
        int optcnt = 0;
        int tzdone = 0;

        myname = strrchr(argv[0], '/');
        myname = myname ? myname + 1 : argv[0];
        (void) snprintf(typename, sizeof (typename), "%s_%s",
            MNTTYPE_PCFS, myname);
        argv[0] = typename;

        while ((c = getopt(argc, argv, "Vvmr?o:Oq")) != EOF) {
                switch (c) {
                case 'V':
                case 'v':
                        verbose++;
                        break;
                case '?':
                        error++;
                        break;
                case 'r':
                        roflag++;
                        break;
                case 'm':
                        mflg |= MS_NOMNTTAB;
                        break;
                case 'o':
                        in_arg = optarg;
                        if ((savedoptarg = strdup(optarg)) == NULL) {
                                (void) fprintf(stderr,
                                    gettext("%s: out of memory\n"), myname);
                                exit(2);
                        }
                        while (*in_arg != '\0') {
                                curarg = in_arg;

                                switch (getsubopt(&in_arg, pcfs_opts, &val)) {
                                case ARG_PCFS_TIMEZONE:
                                        if (tzdone || val == NULL)
                                                goto invalarg;
                                        tzval = val;
                                        (void) snprintf(tzstr, 100,
                                            "TZ=%s", tzval);
                                        tzstr[99] = '\0';
                                        (void) putenv(tzstr);
                                        tzdone = 1;
                                        break;
                                default:
                                        /*
                                         * Remove empty suboptions
                                         * (happens on sequences of commas)
                                         */
                                        if (*curarg == '\0')
                                                break;

                                        if (append_opt(optbuf, sizeof (optbuf),
                                            curarg) == 0)
                                                goto invalarg;
                                }
                        }
                        break;
                case 'O':
                        mflg |= MS_OVERLAY;
                        break;
                case 'q':
                        qflg = 1;
                        break;
                }
        }

        if (verbose && !error) {
                char *optptr;

                (void) fprintf(stderr, "%s", typename);
                for (optcnt = 1; optcnt < argc; optcnt++) {
                        optptr = argv[optcnt];
                        if (optptr)
                                (void) fprintf(stderr, " %s", optptr);
                }
                (void) fprintf(stderr, "\n");
        }

        if (argc - optind != 2 || error) {
                /*
                 * don't hint at options yet (none are really supported)
                 */
                (void) fprintf(stderr, gettext(
                    "Usage: %s [generic options] [-o suboptions] "
                    "special mount_point\n"), typename);
                (void) fprintf(stderr, gettext(
                    "\tpcfs-specific suboptions are:\n"
                    "\t     clamptime,noclamptime\n"
                    "\t     hidden,nohidden\n"
                    "\t     atime,noatime\n"
                    "\t     foldcase,nofoldcase\n"
                    "\t     timezone=<valid TZ string>"));
                exit(32);
        }

        mnt_special = argv[optind++];
        mnt_mountp = argv[optind++];

        /*
         * Pass timezone information to the kernel module so that
         * FAT timestamps, as per spec, can be recorded in local time.
         */
        tzset();
        /*
         * We perform this validation only in case the user of
         * mount(8) specified the "timezone=..." option. That's
         * because we don't want PCFS mounts to fail due to a
         * botched $TZ environment variable. If the admin's
         * environment contains garbage, it'll just parse as
         * GMT (timezone=0).
         */
        if (tzdone && timezone == 0 && altzone == 0 && daylight == 0 &&
            strcmp(tzname[0], tzval) &&
            strspn(tzname[1], " ") == strlen(tzname[1])) {
                goto invalarg;
        }
        (void) snprintf(tzstr, 100, "timezone=%d", timezone);
        tzstr[99] = '\0';
        if (append_opt(optbuf, sizeof (optbuf), tzstr) == 0)
                goto invalarg;

        optsize = strlen(optbuf);

        if (roflag)
                mflg |= MS_RDONLY;

        if ((savedoptbuf = strdup(optbuf)) == NULL) {
                (void) fprintf(stderr, gettext("%s: out of memory\n"),
                    myname);
                exit(2);
        }
        (void) signal(SIGHUP,  SIG_IGN);
        (void) signal(SIGQUIT, SIG_IGN);
        (void) signal(SIGINT,  SIG_IGN);

        if (verbose) {
                (void) fprintf(stderr, "mount(%s, \"%s\", %d, %s",
                    mnt_special, mnt_mountp, mflg, MNTTYPE_PCFS);
        }
        if (mount(mnt_special, mnt_mountp, mflg, MNTTYPE_PCFS,
            NULL, 0, optbuf, MAX_MNTOPT_STR)) {
                if (errno == EBUSY) {
                        (void) fprintf(stderr, gettext(
                            "mount: %s is already mounted or %s is busy\n"),
                            mnt_special, mnt_mountp);
                } else if (errno == EINVAL) {
                        (void) fprintf(stderr, gettext(
                            "mount: %s is not a DOS filesystem.\n"),
                            mnt_special);
                } else {
                        perror("mount");
                }
                exit(32);
        }

        if (optsize && !qflg)
                cmp_requested_to_actual_options(savedoptbuf, optbuf,
                    mnt_special, mnt_mountp);
        return (0);

invalarg:
        (void) fprintf(stderr,
            gettext("%s: Invalid mount options: %s\n"), myname, savedoptarg);
        return (2);
}