src/tools/dumpscan/util.c

   1 /*
   2  * CMUCS AFStools
   3  * dumpscan - routines for scanning and manipulating AFS volume dumps
   4  *
   5  * Copyright (c) 1998 Carnegie Mellon University
   6  * All Rights Reserved.
   7  *
   8  * Permission to use, copy, modify and distribute this software and its
   9  * documentation is hereby granted, provided that both the copyright
  10  * notice and this permission notice appear in all copies of the
  11  * software, derivative works or modified versions, and any portions
  12  * thereof, and that both notices appear in supporting documentation.
  13  *
  14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  17  *
  18  * Carnegie Mellon requests users of this software to return to
  19  *
  20  *  Software Distribution Coordinator  or  Software_Distribution@CS.CMU.EDU
  21  *  School of Computer Science
  22  *  Carnegie Mellon University
  23  *  Pittsburgh PA 15213-3890
  24  *
  25  * any improvements or extensions that they make and grant Carnegie Mellon
  26  * the rights to redistribute these changes.
  27  */
  28
  29 /* util.c - Useful utilities */
  30
  31 #include <errno.h>
  32
  33 #include "xf_errs.h"
  34 #include "dumpscan.h"
  35 #include "dumpscan_errs.h"
  36 #include "dumpfmt.h"
  37
  38
  39 /* Take care of errno, ERROR_XFILE_EOF, and ENOMEM return codes.
  40  * Call whatever callbacks are necessary, and return the code to
  41  * actually use.  If you don't want '0' to result in a DSERR_TAG,
  42  * then you must translate it to DSERR_DONE before calling this.
  43  */
  44 /*** THIS FUNCTION INTENDED FOR INTERNAL USE ONLY ***/
  45 int
  46 handle_return(int r, XFILE * X, unsigned char tag, dump_parser * p)
  47 {
  48     dt_uint64 where, xwhere;
  49
  50     switch (r) {
  51     case 0:
  52         if (p->cb_error) {
  53             xftell(X, &where);
  54             sub64_32(xwhere, where, 1);
  55             (p->cb_error) (DSERR_TAG, 1, p->err_refcon,
  56                            (tag > 0x20 && tag < 0x7f)
  57                            ? "Unexpected tag '%c' at %s = 0x%s" :
  58                            "Unexpected tag 0x%02x at %s = 0x%s", tag,
  59                            decimate_int64(&xwhere, 0), hexify_int64(&xwhere,
  60                                                                     0));
  61         }
  62         return DSERR_TAG;
  63
  64     case ERROR_XFILE_EOF:
  65         if (p->cb_error) {
  66             xftell(X, &where);
  67             (p->cb_error) (ERROR_XFILE_EOF, 1, p->err_refcon,
  68                            "Unexpected EOF at %s = 0x%s",
  69                            decimate_int64(&where, 0), hexify_int64(&where,
  70                                                                    0));
  71         }
  72         return ERROR_XFILE_EOF;
  73
  74     case ENOMEM:
  75         if (p->cb_error) {
  76             xftell(X, &where);
  77             (p->cb_error) (ENOMEM, 1, p->err_refcon,
  78                            "Out of memory at %s = 0x%s",
  79                            decimate_int64(&where, 0), hexify_int64(&where,
  80                                                                    0));
  81         }
  82         return ENOMEM;
  83
  84     case DSERR_DONE:
  85         return 0;
  86
  87     default:
  88         /* For other negative valuees, the callback was already done */
  89         if (r > 0 && p->cb_error)
  90             (p->cb_error) (r, 1, p->err_refcon,
  91                            "System error %d reading dump file", r);
  92         return r;
  93     }
  94 }
  95
  96
  97 /* Prepare a tag_parse_info for use by the dump parser. */
  98 /* ** THIS FUNCTION INTENDED FOR INTERNAL USE ONLY ** */
  99 void
 100 prep_pi(dump_parser * p, tag_parse_info * pi)
 101 {
 102     memset(pi, 0, sizeof(tag_parse_info));
 103     pi->err_refcon = p->err_refcon;
 104     pi->cb_error = p->cb_error;
 105
 106     if (p->repair_flags & DSFIX_SKIP)
 107         pi->flags |= TPFLAG_SKIP;
 108     if ((p->flags & DSFLAG_SEEK) && (p->repair_flags & DSFIX_RSKIP))
 109         pi->flags |= TPFLAG_RSKIP;
 110 }
 111
 112
 113 /* Does the designated location match a vnode?
 114  * Returns 0 if yes, DSERR_FMT if no, something else on error
 115  */
 116 /*** THIS FUNCTION INTENDED FOR INTERNAL USE ONLY ***/
 117 int
 118 match_next_vnode(XFILE * X, dump_parser * p, dt_uint64 * where,
 119                  afs_uint32 vnode)
 120 {
 121     afs_uint32 r, x, y, z;
 122     unsigned char tag;
 123
 124     if ((r = xfseek(X, where)))
 125         return r;
 126     if ((r = ReadByte(X, &tag)))
 127         return r;
 128     switch (tag) {
 129     case 3:                     /* A vnode? */
 130         if ((r = ReadInt32(X, &x)))
 131             return r;
 132         if ((r = ReadInt32(X, &y)))
 133             return r;
 134         if ((r = ReadByte(X, &tag)))
 135           return r;
 136         if (!((vnode & 1) && !(x & 1) && x < vnode)
 137             && !((vnode & 1) == (x & 1) && x > vnode))
 138             return DSERR_FMT;
 139         if (x > vnode && x - vnode > 10000)
 140             return DSERR_FMT;
 141         if (y > p->vol_uniquifier)
 142             return DSERR_FMT;
 143
 144         /* Now, what follows the vnode/uniquifier? */
 145         switch (tag) {
 146         case 3:         /* Another vnode? - Only if this is a non-directory */
 147             if (x & 1)
 148                 return DSERR_FMT;
 149             if ((r = ReadInt32(X, &z)))
 150                 return r;
 151             if (!((x & 1) && !(z & 1) && z < x)
 152                 && !((x & 1) == (z & 1) && z > x))
 153                 return DSERR_FMT;
 154             return 0;
 155
 156         case 4:         /* Dump end - Only if this is a non-directory */
 157             if (x & 1)
 158                 return DSERR_FMT;
 159             if ((r = ReadInt32(X, &z)))
 160                 return r;
 161             if (z != DUMPENDMAGIC)
 162                 return DSERR_FMT;
 163             return 0;
 164
 165         case 't':               /* Vnode type byte */
 166             if ((r = ReadByte(X, &tag)))
 167                 return r;
 168             if ((tag == vFile || tag == vSymlink) && !(x & 1))
 169                 return 0;
 170             if (tag == vDirectory && (x & 1))
 171                 return 0;
 172             return DSERR_FMT;
 173
 174         default:
 175             return DSERR_FMT;
 176         }
 177
 178     case 4:                     /* A dump end? */
 179         if ((r = ReadInt32(X, &x)))
 180             return r;
 181         if (x != DUMPENDMAGIC)
 182             return DSERR_FMT;
 183         return 0;
 184
 185     default:
 186         return DSERR_FMT;
 187     }
 188 }