parsenfs.c

This directory contains source code for tcpdump, a tool for network monitoring and data acquisition

/*
 * parsenfsfh.c - portable parser for NFS file handles
 *                      uses all sorts of heuristics
 *
 * Jeffrey C. Mogul
 * Digital Equipment Corporation
 * Western Research Laboratory
 *
 * $FreeBSD: src/contrib/tcpdump/parsenfsfh.c,v 1.5 2000/01/30 01:00:50 fenner Exp $
 */

#if 0
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/parsenfsfh.c,v 1.16 1999/11/21 09:36:47 fenner Exp $ (LBL)";
#endif

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

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

#include "interfac.h"
#include "nfsfh.h"

/*
 * 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

#define XFF(x)        (x)

#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))

/* on 32-bit systems ignore high-order bits */
#define make_uint48(msb,b,c,d,e,lsb)\
        ((lsb) + ((e)<<8) + ((d)<<16) + ((c)<<24))

static int is_UCX (unsigned char *);

void Parse_fh (caddr_t *fh, int len, 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 */
{
  u_char   *fhp = (unsigned char *) fh;
  u_int32_t temp;
  int       i, 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)
             memset ((char*)fsidp, 0, sizeof(*fsidp));
           /* just use the whole thing */
           memcpy ((char*)fsidp, (char*)fh, 14);
         }
         else
         {
           u_int32_t tempa[4];  /* at least 16 bytes, maybe more */

           memset ((char*)tempa, 0, sizeof(tempa));
           memcpy ((char*)tempa, (char*)fh, 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 */

         for (i = 0; i < 32; i++)
             PRINTF ("%x.", fhp[i]);
         PUTCHAR ('\n');
#endif
         /* XXX for now, give "bogus" values to aid debugging
          *
          * Save the actual handle, so it can be display with -u
          */
         memset (fsidp->Opaque_Handle,0,sizeof(fsidp->Opaque_Handle));
         for (i = 0; i < 32; i++)
             sprintf (&fsidp->Opaque_Handle[i*2], "%.2X", fhp[i]);

         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 (unsigned char *fhp)
{
  int i, 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);
}