/*
 * Copyright (c) 2000-2001, Boris Popov
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Boris Popov.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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.
 *
 * $FreeBSD: src/sys/fs/smbfs/smbfs_subr.c,v 1.1.2.2 2003/01/17 08:20:26 tjr Exp $
 * $DragonFly: src/sys/vfs/smbfs/smbfs_subr.c,v 1.4 2003/08/07 21:54:36 dillon Exp $
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <machine/clock.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/sysctl.h>
#include <sys/iconv.h>

#include <netproto/smb/smb.h>
#include <netproto/smb/smb_conn.h>
#include <netproto/smb/smb_subr.h>
#include <netproto/smb/smb_rq.h>
#include <netproto/smb/smb_dev.h>

#include "smbfs.h"
#include "smbfs_node.h"
#include "smbfs_subr.h"

MALLOC_DEFINE(M_SMBFSDATA, "SMBFS data", "SMBFS private data");

/* 
 * Time & date conversion routines taken from msdosfs. Although leap
 * year calculation is bogus, it's sufficient before 2100 :)
 */
/*
 * This is the format of the contents of the deTime field in the direntry
 * structure.
 * We don't use bitfields because we don't know how compilers for
 * arbitrary machines will lay them out.
 */
#define DT_2SECONDS_MASK        0x1F    /* seconds divided by 2 */
#define DT_2SECONDS_SHIFT       0
#define DT_MINUTES_MASK         0x7E0   /* minutes */
#define DT_MINUTES_SHIFT        5
#define DT_HOURS_MASK           0xF800  /* hours */
#define DT_HOURS_SHIFT          11

/*
 * This is the format of the contents of the deDate field in the direntry
 * structure.
 */
#define DD_DAY_MASK             0x1F    /* day of month */
#define DD_DAY_SHIFT            0
#define DD_MONTH_MASK           0x1E0   /* month */
#define DD_MONTH_SHIFT          5
#define DD_YEAR_MASK            0xFE00  /* year - 1980 */
#define DD_YEAR_SHIFT           9
/*
 * Total number of days that have passed for each month in a regular year.
 */
static u_short regyear[] = {
        31, 59, 90, 120, 151, 181,
        212, 243, 273, 304, 334, 365
};

/*
 * Total number of days that have passed for each month in a leap year.
 */
static u_short leapyear[] = {
        31, 60, 91, 121, 152, 182,
        213, 244, 274, 305, 335, 366
};

/*
 * Variables used to remember parts of the last time conversion.  Maybe we
 * can avoid a full conversion.
 */
static u_long  lasttime;
static u_long  lastday;
static u_short lastddate;
static u_short lastdtime;

void
smb_time_local2server(struct timespec *tsp, int tzoff, u_long *seconds)
{
        *seconds = tsp->tv_sec - tzoff * 60 /*- tz.tz_minuteswest * 60 -
            (wall_cmos_clock ? adjkerntz : 0)*/;
}

void
smb_time_server2local(u_long seconds, int tzoff, struct timespec *tsp)
{
        tsp->tv_sec = seconds + tzoff * 60;
            /*+ tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)*/;
}

/*
 * Number of seconds between 1970 and 1601 year
 */
int64_t DIFF1970TO1601 = 11644473600ULL;

/*
 * Time from server comes as UTC, so no need to use tz
 */
void
smb_time_NT2local(int64_t nsec, int tzoff, struct timespec *tsp)
{
        smb_time_server2local(nsec / 10000000 - DIFF1970TO1601, 0, tsp);
}

void
smb_time_local2NT(struct timespec *tsp, int tzoff, int64_t *nsec)
{
        u_long seconds;

        smb_time_local2server(tsp, 0, &seconds);
        *nsec = (((int64_t)(seconds) & ~1) + DIFF1970TO1601) * (int64_t)10000000;
}

void
smb_time_unix2dos(struct timespec *tsp, int tzoff, u_int16_t *ddp, 
        u_int16_t *dtp, u_int8_t *dhp)
{
        u_long t, days, year, month, inc;
        u_short *months;

        /*
         * If the time from the last conversion is the same as now, then
         * skip the computations and use the saved result.
         */
        smb_time_local2server(tsp, tzoff, &t);
        t &= ~1;
        if (lasttime != t) {
                lasttime = t;
                lastdtime = (((t / 2) % 30) << DT_2SECONDS_SHIFT)
                    + (((t / 60) % 60) << DT_MINUTES_SHIFT)
                    + (((t / 3600) % 24) << DT_HOURS_SHIFT);

                /*
                 * If the number of days since 1970 is the same as the last
                 * time we did the computation then skip all this leap year
                 * and month stuff.
                 */
                days = t / (24 * 60 * 60);
                if (days != lastday) {
                        lastday = days;
                        for (year = 1970;; year++) {
                                inc = year & 0x03 ? 365 : 366;
                                if (days < inc)
                                        break;
                                days -= inc;
                        }
                        months = year & 0x03 ? regyear : leapyear;
                        for (month = 0; days >= months[month]; month++)
                                ;
                        if (month > 0)
                                days -= months[month - 1];
                        lastddate = ((days + 1) << DD_DAY_SHIFT)
                            + ((month + 1) << DD_MONTH_SHIFT);
                        /*
                         * Remember dos's idea of time is relative to 1980.
                         * unix's is relative to 1970.  If somehow we get a
                         * time before 1980 then don't give totally crazy
                         * results.
                         */
                        if (year > 1980)
                                lastddate += (year - 1980) << DD_YEAR_SHIFT;
                }
        }
        if (dtp)
                *dtp = lastdtime;
        if (dhp)
                *dhp = (tsp->tv_sec & 1) * 100 + tsp->tv_nsec / 10000000;

        *ddp = lastddate;
}

/*
 * The number of seconds between Jan 1, 1970 and Jan 1, 1980. In that
 * interval there were 8 regular years and 2 leap years.
 */
#define SECONDSTO1980   (((8 * 365) + (2 * 366)) * (24 * 60 * 60))

static u_short lastdosdate;
static u_long  lastseconds;

void
smb_dos2unixtime(u_int dd, u_int dt, u_int dh, int tzoff,
        struct timespec *tsp)
{
        u_long seconds;
        u_long month;
        u_long year;
        u_long days;
        u_short *months;

        if (dd == 0) {
                tsp->tv_sec = 0;
                tsp->tv_nsec = 0;
                return;
        }
        seconds = (((dt & DT_2SECONDS_MASK) >> DT_2SECONDS_SHIFT) << 1)
            + ((dt & DT_MINUTES_MASK) >> DT_MINUTES_SHIFT) * 60
            + ((dt & DT_HOURS_MASK) >> DT_HOURS_SHIFT) * 3600
            + dh / 100;
        /*
         * If the year, month, and day from the last conversion are the
         * same then use the saved value.
         */
        if (lastdosdate != dd) {
                lastdosdate = dd;
                days = 0;
                year = (dd & DD_YEAR_MASK) >> DD_YEAR_SHIFT;
                days = year * 365;
                days += year / 4 + 1;   /* add in leap days */
                if ((year & 0x03) == 0)
                        days--;         /* if year is a leap year */
                months = year & 0x03 ? regyear : leapyear;
                month = (dd & DD_MONTH_MASK) >> DD_MONTH_SHIFT;
                if (month < 1 || month > 12) {
                        month = 1;
                }
                if (month > 1)
                        days += months[month - 2];
                days += ((dd & DD_DAY_MASK) >> DD_DAY_SHIFT) - 1;
                lastseconds = (days * 24 * 60 * 60) + SECONDSTO1980;
        }
        smb_time_server2local(seconds + lastseconds, tzoff, tsp);
        tsp->tv_nsec = (dh % 100) * 10000000;
}

static int
smb_fphelp(struct mbchain *mbp, struct smb_vc *vcp, struct smbnode *np,
        int caseopt)
{
        struct smbmount *smp= np->n_mount;
        struct smbnode **npp = smp->sm_npstack;
        int i, error = 0;

/*      simple_lock(&smp->sm_npslock);*/
        i = 0;
        while (np->n_parent) {
                if (i++ == SMBFS_MAXPATHCOMP) {
/*                      simple_unlock(&smp->sm_npslock);*/
                        return ENAMETOOLONG;
                }
                *npp++ = np;
                np = VTOSMB(np->n_parent);
        }
/*      if (i == 0)
                return smb_put_dmem(mbp, vcp, "\\", 2, caseopt);*/
        while (i--) {
                np = *--npp;
                error = mb_put_uint8(mbp, '\\');
                if (error)
                        break;
                error = smb_put_dmem(mbp, vcp, np->n_name, np->n_nmlen, caseopt);
                if (error)
                        break;
        }
/*      simple_unlock(&smp->sm_npslock);*/
        return error;
}

int
smbfs_fullpath(struct mbchain *mbp, struct smb_vc *vcp, struct smbnode *dnp,
        const char *name, int nmlen)
{
        int caseopt = SMB_CS_NONE;
        int error;

        if (SMB_DIALECT(vcp) < SMB_DIALECT_LANMAN1_0)
                caseopt |= SMB_CS_UPPER;
        if (dnp != NULL) {
                error = smb_fphelp(mbp, vcp, dnp, caseopt);
                if (error)
                        return error;
        }
        if (name) {
                error = mb_put_uint8(mbp, '\\');
                if (error)
                        return error;
                error = smb_put_dmem(mbp, vcp, name, nmlen, caseopt);
                if (error)
                        return error;
        }
        error = mb_put_uint8(mbp, 0);
        return error;
}

int
smbfs_fname_tolocal(struct smb_vc *vcp, char *name, int nmlen, int caseopt)
{
/*      if (caseopt & SMB_CS_UPPER)
                iconv_convmem(vcp->vc_toupper, name, name, nmlen);
        else if (caseopt & SMB_CS_LOWER)
                iconv_convmem(vcp->vc_tolower, name, name, nmlen);*/
        if (vcp->vc_tolocal)
                iconv_convmem(vcp->vc_tolocal, name, name, nmlen);
        return 0;
}