#ifndef lint
static char *RCSid = "$Header: parsenfsfh.c,v 1.5 94/01/13 19:06:41 leres Exp $";
#endif

/*
 * parsenfsfh.c - portable parser for NFS file handles
 *			uses all sorts of heuristics
 *
 * Jeffrey C. Mogul
 * Digital Equipment Corporation
 * Western Research Laboratory
 */

#include <sys/types.h>
#include <sys/time.h>

#include <stdio.h>
#include <ctype.h>
#include <string.h>

#include "interface.h"
#include "nfsfh.h"

/*
 * Make sure that we use 32-bit integers when necessary.  The "x"
 * suffix is to avoid possible identifier conflicts.
 */

typedef int int32x;
typedef unsigned int u_int32x;

/*
 * This routine attempts to parse a file handle (in network byte order),
 * using heuristics to guess what kind of format it is in.  See the
 * file "fhandle_layouts" for a detailed description of the various
 * patterns we know about.
 *
 * The file handle is parsed into our internal representation of a
 * file-system id, and an internal representation of an inode-number.
 */

#define	FHT_UNKNOWN	0
#define	FHT_AUSPEX	1
#define	FHT_DECOSF	2
#define	FHT_IRIX4	3
#define	FHT_IRIX5	4
#define	FHT_SUNOS3	5
#define	FHT_SUNOS4	6
#define	FHT_ULTRIX	7
#define	FHT_VMSUCX	8
#define	FHT_SUNOS5	9
#define	FHT_AIX32	10
#define	FHT_HPUX9	11

#ifdef	ultrix
/* Nasty hack to keep the Ultrix C compiler from emitting bogus warnings */
#define	XFF(x)	((unsigned long)(x))
#else
#define	XFF(x)	(x)
#endif

#define	make_uint32(msb,b,c,lsb)\
	(XFF(lsb) + (XFF(c)<<8) + (XFF(b)<<16) + (XFF(msb)<<24))

#define	make_uint24(msb,b, lsb)\
	(XFF(lsb) + (XFF(b)<<8) + (XFF(msb)<<16))

#define	make_uint16(msb,lsb)\
	(XFF(lsb) + (XFF(msb)<<8))

#ifdef	__alpha
	/* or other 64-bit systems */
#define	make_uint48(msb,b,c,d,e,lsb)\
	((lsb) + ((e)<<8) + ((d)<<16) + ((c)<<24) + ((b)<<32) + ((msb)<<40))
#else
	/* on 32-bit systems ignore high-order bits */
#define	make_uint48(msb,b,c,d,e,lsb)\
	((lsb) + ((e)<<8) + ((d)<<16) + ((c)<<24))
#endif

static int is_UCX(unsigned char *);

void
Parse_fh(fh, fsidp, inop, osnamep, fsnamep, ourself)
register caddr_t *fh;
my_fsid *fsidp;
ino_t *inop;
char **osnamep;		/* if non-NULL, return OS name here */
char **fsnamep;		/* if non-NULL, return server fs name here (for VMS) */
int ourself;		/* true if file handle was generated on this host */
{
	register unsigned char *fhp = (unsigned char *)fh;
	u_int32x temp;
	int fhtype = FHT_UNKNOWN;

	if (ourself) {
	    /* File handle generated on this host, no need for guessing */
#if	defined(IRIX40)
	    fhtype = FHT_IRIX4;
#endif
#if	defined(IRIX50)
	    fhtype = FHT_IRIX5;
#endif
#if	defined(IRIX51)
	    fhtype = FHT_IRIX5;
#endif
#if	defined(SUNOS4)
	    fhtype = FHT_SUNOS4;
#endif
#if	defined(SUNOS5)
	    fhtype = FHT_SUNOS5;
#endif
#if	defined(ultrix)
	    fhtype = FHT_ULTRIX;
#endif
#if	defined(__osf__)
	    fhtype = FHT_DECOSF;
#endif
	}
	/*
	 * This is basically a big decision tree
	 */
	else if ((fhp[0] == 0) && (fhp[1] == 0)) {
	    /* bytes[0,1] == (0,0); rules out Ultrix, IRIX5, SUNOS5 */
	    /* probably rules out HP-UX, AIX unless they allow major=0 */
	    if ((fhp[2] == 0) && (fhp[3] == 0)) {
		/* bytes[2,3] == (0,0); must be Auspex */
		/* XXX or could be Ultrix+MASSBUS "hp" disk? */
		fhtype = FHT_AUSPEX;
	    }
	    else {
		/*
		 * bytes[2,3] != (0,0); rules out Auspex, could be
		 * DECOSF, SUNOS4, or IRIX4
		 */
		if ((fhp[4] != 0) && (fhp[5] == 0) &&
			(fhp[8] == 12) && (fhp[9] == 0)) {
		    /* seems to be DECOSF, with minor == 0 */
		    fhtype = FHT_DECOSF;
		}
		else {
		    /* could be SUNOS4 or IRIX4 */
		    /* XXX the test of fhp[5] == 8 could be wrong */
		    if ((fhp[4] == 0) && (fhp[5] == 8) && (fhp[6] == 0) &&
			(fhp[7] == 0)) {
			/* looks like a length, not a file system typecode */
			fhtype = FHT_IRIX4;
		    }
		    else {
			/* by elimination */
			fhtype = FHT_SUNOS4;
		    }
		}
	    }
	}
	else {
	    /*
	     * bytes[0,1] != (0,0); rules out Auspex, IRIX4, SUNOS4
	     * could be IRIX5, DECOSF, UCX, Ultrix, SUNOS5
	     * could be AIX, HP-UX
	     */
	    if ((fhp[2] == 0) && (fhp[3] == 0)) {
		/*
		 * bytes[2,3] == (0,0); rules out OSF, probably not UCX
		 * (unless the exported device name is just one letter!),
		 * could be Ultrix, IRIX5, AIX, or SUNOS5
		 * might be HP-UX (depends on their values for minor devs)
		 */
		/*XXX we probably only need to test of these two bytes */
		if ((fhp[21] == 0) && (fhp[23] == 0)) {
		    fhtype = FHT_ULTRIX;
		}
		else {
		    /* Could be SUNOS5/IRIX5, maybe AIX */
		    /* XXX no obvious difference between SUNOS5 and IRIX5 */
		    if (fhp[9] == 10)
			fhtype = FHT_SUNOS5;
		    /* XXX what about AIX? */
		}
	    }
	    else {
		/*
		 * bytes[2,3] != (0,0); rules out Ultrix, could be
		 * DECOSF, SUNOS5, IRIX5, AIX, HP-UX, or UCX
		 */
		if ((fhp[8] == 12) && (fhp[9] == 0)) {
		    fhtype = FHT_DECOSF;
		}
		else if ((fhp[8] == 0) && (fhp[9] == 10)) {
		    /* could be SUNOS5/IRIX5, AIX, HP-UX */
		    if ((fhp[7] == 0) && (fhp[6] == 0) &&
			(fhp[5] == 0) && (fhp[4] == 0)) {
			/* XXX is this always true of HP-UX? */
			fhtype = FHT_HPUX9;
		    }
		    else if (fhp[7] == 2) {
			/* This would be MNT_NFS on AIX, which is impossible */
			fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
		    }
		    else {
			/*
			 * XXX Could be SUNOS5/IRIX5 or AIX.  I don't
			 * XXX see any way to disambiguate these, so
			 * XXX I'm going with the more likely guess.
			 * XXX Sorry, Big Blue.
			 */
			fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
		    }
	        }
		else {
		    if (is_UCX(fhp)) {
			fhtype = FHT_VMSUCX;
		    }
		    else {
			fhtype = FHT_UNKNOWN;
		    }
		}
	    }
	}

	/* XXX still needs to handle SUNOS3 */

	switch (fhtype) {
	case FHT_AUSPEX:
	    fsidp->fsid_dev.Minor = fhp[7];
	    fsidp->fsid_dev.Major = fhp[6];
	    fsidp->fsid_code = 0;

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "Auspex";
	    break;

	case FHT_DECOSF:
	    fsidp->fsid_code = make_uint32(fhp[7], fhp[6], fhp[5], fhp[4]);
			/* XXX could ignore 3 high-order bytes */

	    temp = make_uint32(fhp[3], fhp[2], fhp[1], fhp[0]);
	    fsidp->fsid_dev.Minor = temp & 0xFFFFF;
	    fsidp->fsid_dev.Major = (temp>>20) & 0xFFF;

	    temp = make_uint32(fhp[15], fhp[14], fhp[13], fhp[12]);
	    *inop = temp;
	    if (osnamep)
		*osnamep = "OSF";
	    break;

	case FHT_IRIX4:
	    fsidp->fsid_dev.Minor = fhp[3];
	    fsidp->fsid_dev.Major = fhp[2];
	    fsidp->fsid_code = 0;

	    temp = make_uint32(fhp[8], fhp[9], fhp[10], fhp[11]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "IRIX4";
	    break;

	case FHT_IRIX5:
	    fsidp->fsid_dev.Minor = make_uint16(fhp[2], fhp[3]);
	    fsidp->fsid_dev.Major = make_uint16(fhp[0], fhp[1]);
	    fsidp->fsid_code = make_uint32(fhp[4], fhp[5], fhp[6], fhp[7]);

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "IRIX5";
	    break;

	case FHT_SUNOS3:
	    if (osnamep)
		*osnamep = "SUNOS3";
	    break;

	case FHT_SUNOS4:
	    fsidp->fsid_dev.Minor = fhp[3];
	    fsidp->fsid_dev.Major = fhp[2];
	    fsidp->fsid_code = make_uint32(fhp[4], fhp[5], fhp[6], fhp[7]);

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "SUNOS4";
	    break;

	case FHT_SUNOS5:
	    temp = make_uint16(fhp[0], fhp[1]);
	    fsidp->fsid_dev.Major = (temp>>2) &  0x3FFF;
	    temp = make_uint24(fhp[1], fhp[2], fhp[3]);
	    fsidp->fsid_dev.Minor = temp & 0x3FFFF;
	    fsidp->fsid_code = make_uint32(fhp[4], fhp[5], fhp[6], fhp[7]);

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "SUNOS5";
	    break;

	case FHT_ULTRIX:
	    fsidp->fsid_code = 0;
	    fsidp->fsid_dev.Minor = fhp[0];
	    fsidp->fsid_dev.Major = fhp[1];

	    temp = make_uint32(fhp[7], fhp[6], fhp[5], fhp[4]);
	    *inop = temp;
	    if (osnamep)
		*osnamep = "Ultrix";
	    break;

	case FHT_VMSUCX:
	    /* No numeric file system ID, so hash on the device-name */
	    if (sizeof(*fsidp) >= 14) {
		if (sizeof(*fsidp) > 14)
		    bzero((char *)fsidp, sizeof(*fsidp));
		bcopy(fh, (char *)fsidp, 14);	/* just use the whole thing */
	    }
	    else {
		u_long tempa[4];	/* at least 16 bytes, maybe more */

		bzero((char *)tempa, sizeof(tempa));
		bcopy(fh, (char *)tempa, 14);	/* ensure alignment */
		fsidp->fsid_dev.Minor = tempa[0] + (tempa[1]<<1);
		fsidp->fsid_dev.Major = tempa[2] + (tempa[3]<<1);
		fsidp->fsid_code = 0;
	    }

	    /* VMS file ID is: (RVN, FidHi, FidLo) */
	    *inop = make_uint32(fhp[26], fhp[27], fhp[23], fhp[22]);

	    /* Caller must save (and null-terminate?) this value */
	    if (fsnamep)
		*fsnamep = (char *)&(fhp[1]);

	    if (osnamep)
		*osnamep = "VMS";
	    break;

	case FHT_AIX32:
	    fsidp->fsid_dev.Minor = make_uint16(fhp[2], fhp[3]);
	    fsidp->fsid_dev.Major = make_uint16(fhp[0], fhp[1]);
	    fsidp->fsid_code = make_uint32(fhp[4], fhp[5], fhp[6], fhp[7]);

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "AIX32";
	    break;

	case FHT_HPUX9:
	    fsidp->fsid_dev.Major = fhp[0];
	    temp = make_uint24(fhp[1], fhp[2], fhp[3]);
	    fsidp->fsid_dev.Minor = temp;
	    fsidp->fsid_code = make_uint32(fhp[4], fhp[5], fhp[6], fhp[7]);

	    temp = make_uint32(fhp[12], fhp[13], fhp[14], fhp[15]);
	    *inop = temp;

	    if (osnamep)
		*osnamep = "HPUX9";
	    break;

	case FHT_UNKNOWN:
#ifdef DEBUG
	    {
		/* XXX debugging */
		int i;
		for (i=0; i<32;i++) fprintf(stderr, "%x.", fhp[i]);
		fprintf(stderr, "\n");
	    }
#endif
	    /* XXX for now, give "bogus" values to aid debugging */
	    fsidp->fsid_code = 0;
	    fsidp->fsid_dev.Minor = 257;
	    fsidp->fsid_dev.Major = 257;
	    *inop = 1;

	    /* display will show this string instead of (257,257) */
	    if (fsnamep)
		*fsnamep = "Unknown";

	    if (osnamep)
		*osnamep = "Unknown";
	    break;

	}
}

/*
 * Is this a VMS UCX file handle?
 *	Check for:
 *	(1) leading code byte	[XXX not yet]
 *	(2) followed by string of printing chars & spaces
 *	(3) followed by string of nulls
 */
static int
is_UCX(fhp)
unsigned char *fhp;
{
	register int i;
	int seen_null = 0;

	for (i = 1; i < 14; i++) {
	    if (isprint(fhp[i])) {
		if (seen_null)
		   return(0);
		else
		   continue;
	    }
	    else if (fhp[i] == 0) {
		seen_null = 1;
		continue;
	    }
	    else
		return(0);
	}

	return(1);
}
