external/bsd/bind/dist/contrib/zkt/domaincmp.c

   1 /*      $NetBSD$        */
   2
   3 /*****************************************************************
   4 **
   5 **      @(#) domaincmp.c -- compare two domain names
   6 **
   7 **      Copyright (c) Aug 2005, Karle Boss, Holger Zuleger (kaho).
   8 **      All rights reserved.
   9 **
  10 **      This software is open source.
  11 **
  12 **      Redistribution and use in source and binary forms, with or without
  13 **      modification, are permitted provided that the following conditions
  14 **      are met:
  15 **
  16 **      Redistributions of source code must retain the above copyright notice,
  17 **      this list of conditions and the following disclaimer.
  18 **
  19 **      Redistributions in binary form must reproduce the above copyright notice,
  20 **      this list of conditions and the following disclaimer in the documentation
  21 **      and/or other materials provided with the distribution.
  22 **
  23 **      Neither the name of Karle Boss or Holger Zuleger (kaho) nor the
  24 **      names of its contributors may be used to endorse or promote products
  25 **      derived from this software without specific prior written permission.
  26 **
  27 **      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28 **      "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  29 **      TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  30 **      PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  31 **      LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  32 **      CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  33 **      SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  34 **      INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  35 **      CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  36 **      ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  37 **      POSSIBILITY OF SUCH DAMAGE.
  38 **
  39 *****************************************************************/
  40 # include <stdio.h>
  41 # include <string.h>
  42 # include <assert.h>
  43 # include <ctype.h>
  44 #define extern
  45 # include "domaincmp.h"
  46 #undef extern
  47
  48
  49 #define goto_labelstart(str, p) while ( (p) > (str) && *((p)-1) != '.' ) \
  50                                         (p)--
  51
  52 /*****************************************************************
  53 **      int domaincmp (a, b)
  54 **      compare a and b as fqdns.
  55 **      return <0 | 0 | >0 as in strcmp
  56 **      A subdomain is less than the corresponding parent domain,
  57 **      thus domaincmp ("z.example.net", "example.net") return < 0 !!
  58 *****************************************************************/
  59 int     domaincmp (const char *a, const char *b)
  60 {
  61         register const  char    *pa;
  62         register const  char    *pb;
  63
  64         if ( a == NULL ) return -1;
  65         if ( b == NULL ) return 1;
  66
  67         if ( *a == '.' )        /* skip a leading dot */
  68                 a++;
  69         if ( *b == '.' )        /* same at the other string */
  70                 b++;
  71
  72         /* let pa and pb point to the last non dot char */
  73         pa = a + strlen (a);
  74         do
  75                 pa--;
  76         while ( pa > a && *pa == '.' );
  77
  78         pb = b + strlen (b);
  79         do
  80                 pb--;
  81         while ( pb > b && *pb == '.' );
  82
  83         /* cmp  both domains starting at the end */
  84         while ( *pa == *pb && pa > a && pb > b )
  85                 pa--, pb--;
  86
  87         if ( *pa != *pb )       /* both domains are different ? */
  88         {
  89                 if ( *pa == '.' )
  90                         pa++;                   /* set to beginning of next label */
  91                 else
  92                         goto_labelstart (a, pa);        /* find begin of current label */
  93                 if ( *pb == '.' )
  94                         pb++;                   /* set to beginning of next label */
  95                 else
  96                         goto_labelstart (b, pb);        /* find begin of current label */
  97         }
  98         else            /* maybe one of them has a subdomain */
  99         {
 100                 if ( pa > a )
 101                         if ( pa[-1] == '.' )
 102                                 return -1;
 103                         else
 104                                 goto_labelstart (a, pa);
 105                 else if ( pb > b )
 106                         if ( pb[-1] == '.' )
 107                                 return 1;
 108                         else
 109                                 goto_labelstart (b, pb);
 110                 else
 111                         return 0;       /* both are at the beginning, so they are equal */
 112         }
 113
 114         /* both domains are definitly unequal */
 115         while ( *pa == *pb )    /* so we have to look at the point where they differ */
 116                 pa++, pb++;
 117
 118         return *pa - *pb;
 119 }
 120
 121 #ifdef DOMAINCMP_TEST
 122 static  struct {
 123          char    *a;
 124          char    *b;
 125          int     res;
 126 } ex[] = {
 127          { ".",          ".",    0 },
 128          { "test",       "",   1 },
 129          { "",                   "test2", -1 },
 130          { "",                   "",     0 },
 131          { "de",         "de",   0 },
 132          { ".de",         "de",   0 },
 133          { "de.",        "de.",  0 },
 134          { ".de",        ".de",  0 },
 135          { ".de.",       ".de.", 0 },
 136          { ".de",        "zde",  -1 },
 137          { ".de",        "ade",  1 },
 138          { "zde",        ".de",  1 },
 139          { "ade",        ".de",  -1 },
 140          { "a.de",       ".de",  -1 },
 141          { ".de",        "a.de",  1 },
 142          { "a.de",       "b.de", -1 },
 143          { "a.de.",       "b.de", -1 },
 144          { "a.de",       "b.de.", -1 },
 145          { "a.de",       "a.de.", 0 },
 146          { "aa.de",      "b.de", -1 },
 147          { "ba.de",      "b.de", 1 },
 148          { "a.de",       "a.dk", -1 },
 149          { "anna.example.de",    "anna.example.de",      0 },
 150          { "anna.example.de",    "annamirl.example.de",  -1 },
 151          { "anna.example.de",    "ann.example.de",       1 },
 152          { "example.de.",        "xy.example.de.",       1 },
 153          { "example.de.",        "ab.example.de.",       1 },
 154          { "example.de",        "ab.example.de",       1 },
 155          { "ab.example.de",        "example.de",       -1 },
 156          { "ab.mast.de",          "axt.de",             1 },
 157          { "ab.mast.de",          "obt.de",             -1 },
 158          { "abc.example.de.",    "xy.example.de.",       -1 },
 159          { NULL, NULL,   0 }
 160 };
 161
 162 const char      *progname;
 163 main (int argc, char *argv[])
 164 {
 165
 166         int     expect;
 167         int     res;
 168         int     c;
 169         int     i;
 170
 171         progname = *argv;
 172
 173         for ( i = 0; ex[i].a; i++ )
 174         {
 175                 expect = ex[i].res;
 176                 if ( expect < 0 )
 177                         c = '<';
 178                 else if ( expect > 0 )
 179                         c = '>';
 180                 else
 181                         c = '=';
 182                 printf ("%-20s %-20s ==> %c 0 ", ex[i].a, ex[i].b, c);
 183                 fflush (stdout);
 184                 res = domaincmp (ex[i].a, ex[i].b);
 185                 printf ("%3d  ", res);
 186                 if ( res < 0 && expect < 0 || res > 0 && expect > 0 || res == 0 && expect == 0 )
 187                         puts ("ok");
 188                 else
 189                         puts ("not ok");
 190         }
 191 }
 192 #endif