/*-
 * 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 1.9 2005/10/31 15:41:21 rwatson 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 <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>
#include <netsmb/smb_rq.h>
#include <netsmb/smb_dev.h>

#include <fs/smbfs/smbfs.h>
#include <fs/smbfs/smbfs_node.h>
#include <fs/smbfs/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_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_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)*/;
}

/*
 * Number of seconds between 1970 and 1601 year
 */
static 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;
		if ((np->n_flag & NREFPARENT) == 0)
			break;
		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)
{
	int copt = (caseopt == SMB_CS_LOWER ? KICONV_FROM_LOWER : 
		    (caseopt == SMB_CS_UPPER ? KICONV_FROM_UPPER : 0));
	int error = 0;
	size_t ilen = *nmlen;
	size_t olen;
	char *ibuf = name;
	char outbuf[SMB_MAXFNAMELEN];
	char *obuf = outbuf;

	if (vcp->vc_tolocal) {
		olen = sizeof(outbuf);
		bzero(outbuf, sizeof(outbuf));

		/*
		error = iconv_conv_case
			(vcp->vc_tolocal, NULL, NULL, &obuf, &olen, copt);
		if (error) return error;
		*/

		error = iconv_conv_case
			(vcp->vc_tolocal, (const char **)&ibuf, &ilen, &obuf, &olen, copt);
		if (!error) {
			*nmlen = sizeof(outbuf) - olen;
			memcpy(name, outbuf, *nmlen);
		}
	}
	return error;
}
