source3/smbd/mangle_map.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Name mapping code
   4    Copyright (C) Jeremy Allison 1998
   5    Copyright (C) Andrew Tridgell 2002
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24
  25 /* ************************************************************************** **
  26  * Used only in do_fwd_mangled_map(), below.
  27  * ************************************************************************** **
  28  */
  29 static char *map_filename( char *s,         /* This is null terminated */
  30                            const char *pattern,   /* This isn't. */
  31                            int len )        /* This is the length of pattern. */
  32   {
  33   static pstring matching_bit;  /* The bit of the string which matches */
  34                                 /* a * in pattern if indeed there is a * */
  35   char *sp;                     /* Pointer into s. */
  36   char *pp;                     /* Pointer into p. */
  37   char *match_start;            /* Where the matching bit starts. */
  38   pstring pat;
  39
  40   StrnCpy( pat, pattern, len ); /* Get pattern into a proper string! */
  41   pstrcpy( matching_bit, "" );  /* Match but no star gets this. */
  42   pp = pat;                     /* Initialize the pointers. */
  43   sp = s;
  44
  45   if( strequal(s, ".") || strequal(s, ".."))
  46     {
  47     return NULL;                /* Do not map '.' and '..' */
  48     }
  49
  50   if( (len == 1) && (*pattern == '*') )
  51     {
  52     return NULL;                /* Impossible, too ambiguous for */
  53     }                           /* words! */
  54
  55   while( (*sp)                  /* Not the end of the string. */
  56       && (*pp)                  /* Not the end of the pattern. */
  57       && (*sp == *pp)           /* The two match. */
  58       && (*pp != '*') )         /* No wildcard. */
  59     {
  60     sp++;                       /* Keep looking. */
  61     pp++;
  62     }
  63
  64   if( !*sp && !*pp )            /* End of pattern. */
  65     return( matching_bit );     /* Simple match.  Return empty string. */
  66
  67   if( *pp == '*' )
  68     {
  69     pp++;                       /* Always interrested in the chacter */
  70                                 /* after the '*' */
  71     if( !*pp )                  /* It is at the end of the pattern. */
  72       {
  73       StrnCpy( matching_bit, s, sp-s );
  74       return( matching_bit );
  75       }
  76     else
  77       {
  78       /* The next character in pattern must match a character further */
  79       /* along s than sp so look for that character. */
  80       match_start = sp;
  81       while( (*sp)              /* Not the end of s. */
  82           && (*sp != *pp) )     /* Not the same  */
  83         sp++;                   /* Keep looking. */
  84       if( !*sp )                /* Got to the end without a match. */
  85         {
  86         return( NULL );
  87         }                       /* Still hope for a match. */
  88       else
  89         {
  90         /* Now sp should point to a matching character. */
  91         StrnCpy(matching_bit, match_start, sp-match_start);
  92         /* Back to needing a stright match again. */
  93         while( (*sp)            /* Not the end of the string. */
  94             && (*pp)            /* Not the end of the pattern. */
  95             && (*sp == *pp) )   /* The two match. */
  96           {
  97           sp++;                 /* Keep looking. */
  98           pp++;
  99           }
 100         if( !*sp && !*pp )      /* Both at end so it matched */
 101           return( matching_bit );
 102         else
 103           return( NULL );
 104         }
 105       }
 106     }
 107   return( NULL );               /* No match. */
 108   } /* map_filename */
 109
 110
 111 /* ************************************************************************** **
 112  * MangledMap is a series of name pairs in () separated by spaces.
 113  * If s matches the first of the pair then the name given is the
 114  * second of the pair.  A * means any number of any character and if
 115  * present in the second of the pair as well as the first the
 116  * matching part of the first string takes the place of the * in the
 117  * second.
 118  *
 119  * I wanted this so that we could have RCS files which can be used
 120  * by UNIX and DOS programs.  My mapping string is (RCS rcs) which
 121  * converts the UNIX RCS file subdirectory to lowercase thus
 122  * preventing mangling.
 123  *
 124  * See 'mangled map' in smb.conf(5).
 125  *
 126  * ************************************************************************** **
 127  */
 128 static void mangled_map(char *s, const char *MangledMap)
 129 {
 130         const char *start=MangledMap;       /* Use this to search for mappings. */
 131         const char *end;                    /* Used to find the end of strings. */
 132         char *match_string;
 133         pstring new_string;           /* Make up the result here. */
 134         char *np;                     /* Points into new_string. */
 135
 136         DEBUG( 5, ("Mangled Mapping '%s' map '%s'\n", s, MangledMap) );
 137         while( *start ) {
 138                 while( (*start) && (*start != '(') )
 139                         start++;
 140                 if( !*start )
 141                         continue;                 /* Always check for the end. */
 142                 start++;                    /* Skip the ( */
 143                 end = start;                /* Search for the ' ' or a ')' */
 144                 DEBUG( 5, ("Start of first in pair '%s'\n", start) );
 145                 while( (*end) && !((*end == ' ') || (*end == ')')) )
 146                         end++;
 147                 if( !*end ) {
 148                         start = end;
 149                         continue;                 /* Always check for the end. */
 150                 }
 151                 DEBUG( 5, ("End of first in pair '%s'\n", end) );
 152                 if( (match_string = map_filename( s, start, end-start )) ) {
 153                         int size_left = sizeof(new_string) - 1;
 154                         DEBUG( 5, ("Found a match\n") );
 155                         /* Found a match. */
 156                         start = end + 1; /* Point to start of what it is to become. */
 157                         DEBUG( 5, ("Start of second in pair '%s'\n", start) );
 158                         end = start;
 159                         np = new_string;
 160                         while( (*end && size_left > 0)    /* Not the end of string. */
 161                                && (*end != ')')      /* Not the end of the pattern. */
 162                                && (*end != '*') ) {   /* Not a wildcard. */
 163                                 *np++ = *end++;
 164                                 size_left--;
 165                         }
 166
 167                         if( !*end ) {
 168                                 start = end;
 169                                 continue;               /* Always check for the end. */
 170                         }
 171                         if( *end == '*' ) {
 172                                 if (size_left > 0 )
 173                                         safe_strcpy( np, match_string, size_left );
 174                                 np += strlen( match_string );
 175                                 size_left -= strlen( match_string );
 176                                 end++;                  /* Skip the '*' */
 177                                 while ((*end && size_left >  0)   /* Not the end of string. */
 178                                        && (*end != ')') /* Not the end of the pattern. */
 179                                        && (*end != '*')) { /* Not a wildcard. */
 180                                         *np++ = *end++;
 181                                         size_left--;
 182                                 }
 183                         }
 184                         if (!*end) {
 185                                 start = end;
 186                                 continue;               /* Always check for the end. */
 187                         }
 188                         if (size_left > 0)
 189                                 *np++ = '\0';             /* NULL terminate it. */
 190                         DEBUG(5,("End of second in pair '%s'\n", end));
 191                         new_string[sizeof(new_string)-1] = '\0';
 192                         pstrcpy( s, new_string );  /* Substitute with the new name. */
 193                         DEBUG( 5, ("s is now '%s'\n", s) );
 194                 }
 195                 start = end;  /* Skip a bit which cannot be wanted anymore. */
 196                 start++;
 197         }
 198 }
 199
 200 /*
 201   front end routine to the mangled map code
 202   personally I think that the whole idea of "mangled map" is completely bogus
 203 */
 204 void mangle_map_filename(fstring fname, int snum)
 205 {
 206         char *map;
 207
 208         map = lp_mangled_map(snum);
 209         if (!map || !*map) return;
 210
 211         mangled_map(fname, map);
 212 }