source/lib/ms_fnmatch.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    filename matching routine
   4    Copyright (C) Andrew Tridgell 1992-2004
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 /*
  22    This module was originally based on fnmatch.c copyright by the Free
  23    Software Foundation. It bears little (if any) resemblence to that
  24    code now
  25 */
  26
  27
  28 #include "includes.h"
  29
  30 static int null_match(const smb_ucs2_t *p)
  31 {
  32         for (;*p;p++) {
  33                 if (*p != UCS2_CHAR('*') &&
  34                     *p != UCS2_CHAR('<') &&
  35                     *p != UCS2_CHAR('"') &&
  36                     *p != UCS2_CHAR('>')) return -1;
  37         }
  38         return 0;
  39 }
  40
  41 /*
  42   the max_n structure is purely for efficiency, it doesn't contribute
  43   to the matching algorithm except by ensuring that the algorithm does
  44   not grow exponentially
  45 */
  46 struct max_n {
  47         const smb_ucs2_t *predot;
  48         const smb_ucs2_t *postdot;
  49 };
  50
  51
  52 /*
  53   p and n are the pattern and string being matched. The max_n array is
  54   an optimisation only. The ldot pointer is NULL if the string does
  55   not contain a '.', otherwise it points at the last dot in 'n'.
  56 */
  57 static int ms_fnmatch_core(const smb_ucs2_t *p, const smb_ucs2_t *n,
  58                            struct max_n *max_n, const smb_ucs2_t *ldot)
  59 {
  60         smb_ucs2_t c;
  61         int i;
  62
  63         while ((c = *p++)) {
  64                 switch (c) {
  65                         /* a '*' matches zero or more characters of any type */
  66                 case UCS2_CHAR('*'):
  67                         if (max_n->predot && max_n->predot <= n) {
  68                                 return null_match(p);
  69                         }
  70                         for (i=0; n[i]; i++) {
  71                                 if (ms_fnmatch_core(p, n+i, max_n+1, ldot) == 0) {
  72                                         return 0;
  73                                 }
  74                         }
  75                         if (!max_n->predot || max_n->predot > n) max_n->predot = n;
  76                         return null_match(p);
  77
  78                         /* a '<' matches zero or more characters of
  79                            any type, but stops matching at the last
  80                            '.' in the string. */
  81                 case UCS2_CHAR('<'):
  82                         if (max_n->predot && max_n->predot <= n) {
  83                                 return null_match(p);
  84                         }
  85                         if (max_n->postdot && max_n->postdot <= n && n <= ldot) {
  86                                 return -1;
  87                         }
  88                         for (i=0; n[i]; i++) {
  89                                 if (ms_fnmatch_core(p, n+i, max_n+1, ldot) == 0) return 0;
  90                                 if (n+i == ldot) {
  91                                         if (ms_fnmatch_core(p, n+i+1, max_n+1, ldot) == 0) return 0;
  92                                         if (!max_n->postdot || max_n->postdot > n) max_n->postdot = n;
  93                                         return -1;
  94                                 }
  95                         }
  96                         if (!max_n->predot || max_n->predot > n) max_n->predot = n;
  97                         return null_match(p);
  98
  99                         /* a '?' matches any single character */
 100                 case UCS2_CHAR('?'):
 101                         if (! *n) {
 102                                 return -1;
 103                         }
 104                         n++;
 105                         break;
 106
 107                         /* a '?' matches any single character */
 108                 case UCS2_CHAR('>'):
 109                         if (n[0] == UCS2_CHAR('.')) {
 110                                 if (! n[1] && null_match(p) == 0) {
 111                                         return 0;
 112                                 }
 113                                 break;
 114                         }
 115                         if (! *n) return null_match(p);
 116                         n++;
 117                         break;
 118
 119                 case UCS2_CHAR('"'):
 120                         if (*n == 0 && null_match(p) == 0) {
 121                                 return 0;
 122                         }
 123                         if (*n != UCS2_CHAR('.')) return -1;
 124                         n++;
 125                         break;
 126
 127                 default:
 128                         if (c != *n && toupper_w(c) != toupper_w(*n)) {
 129                                 return -1;
 130                         }
 131                         n++;
 132                         break;
 133                 }
 134         }
 135
 136         if (! *n) {
 137                 return 0;
 138         }
 139
 140         return -1;
 141 }
 142
 143 int ms_fnmatch(const char *pattern, const char *string, enum protocol_types protocol)
 144 {
 145         wpstring p, s;
 146         int ret, count, i;
 147         struct max_n *max_n = NULL;
 148
 149         if (strcmp(string, "..") == 0) {
 150                 string = ".";
 151         }
 152
 153         if (strpbrk(pattern, "<>*?\"") == NULL) {
 154                 /* this is not just an optmisation - it is essential
 155                    for LANMAN1 correctness */
 156                 return StrCaseCmp(pattern, string);
 157         }
 158
 159         pstrcpy_wa(p, pattern);
 160         pstrcpy_wa(s, string);
 161
 162         if (protocol <= PROTOCOL_LANMAN2) {
 163                 /*
 164                   for older negotiated protocols it is possible to
 165                   translate the pattern to produce a "new style"
 166                   pattern that exactly matches w2k behaviour
 167                 */
 168                 for (i=0;p[i];i++) {
 169                         if (p[i] == UCS2_CHAR('?')) {
 170                                 p[i] = UCS2_CHAR('>');
 171                         } else if (p[i] == UCS2_CHAR('.') &&
 172                                    (p[i+1] == UCS2_CHAR('?') ||
 173                                     p[i+1] == UCS2_CHAR('*') ||
 174                                     p[i+1] == 0)) {
 175                                 p[i] = UCS2_CHAR('"');
 176                         } else if (p[i] == UCS2_CHAR('*') && p[i+1] == UCS2_CHAR('.')) {
 177                                 p[i] = UCS2_CHAR('<');
 178                         }
 179                 }
 180         }
 181
 182         for (count=i=0;p[i];i++) {
 183                 if (p[i] == UCS2_CHAR('*') || p[i] == UCS2_CHAR('<')) count++;
 184         }
 185
 186         if (count != 0) {
 187                 max_n = calloc(sizeof(struct max_n), count);
 188                 if (!max_n) {
 189                         return -1;
 190                 }
 191         }
 192
 193         ret = ms_fnmatch_core(p, s, max_n, strrchr_w(s, UCS2_CHAR('.')));
 194
 195         if (max_n) {
 196                 free(max_n);
 197         }
 198
 199         return ret;
 200 }
 201
 202
 203 /* a generic fnmatch function - uses for non-CIFS pattern matching */
 204 int gen_fnmatch(const char *pattern, const char *string)
 205 {
 206         return ms_fnmatch(pattern, string, PROTOCOL_NT1);
 207 }