source3/smbd/map_username.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Username handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1997-2001.
   6    Copyright (C) Volker Lendecke 2006
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/globals.h"
  24
  25 /*******************************************************************
  26  Map a username from a dos name to a unix name by looking in the username
  27  map. Note that this modifies the name in place.
  28  This is the main function that should be called *once* on
  29  any incoming or new username - in order to canonicalize the name.
  30  This is being done to de-couple the case conversions from the user mapping
  31  function. Previously, the map_username was being called
  32  every time Get_Pwnam_alloc was called.
  33  Returns True if username was changed, false otherwise.
  34 ********************************************************************/
  35
  36 static const char *get_last_from(void)
  37 {
  38         if (!last_from) {
  39                 return "";
  40         }
  41         return last_from;
  42 }
  43
  44 static const char *get_last_to(void)
  45 {
  46         if (!last_to) {
  47                 return "";
  48         }
  49         return last_to;
  50 }
  51
  52 static bool set_last_from_to(const char *from, const char *to)
  53 {
  54         char *orig_from = last_from;
  55         char *orig_to = last_to;
  56
  57         last_from = SMB_STRDUP(from);
  58         last_to = SMB_STRDUP(to);
  59
  60         SAFE_FREE(orig_from);
  61         SAFE_FREE(orig_to);
  62
  63         if (!last_from || !last_to) {
  64                 SAFE_FREE(last_from);
  65                 SAFE_FREE(last_to);
  66                 return false;
  67         }
  68         return true;
  69 }
  70
  71 bool map_username(fstring user)
  72 {
  73         XFILE *f;
  74         char *mapfile = lp_username_map();
  75         char *s;
  76         char buf[512];
  77         bool mapped_user = False;
  78         char *cmd = lp_username_map_script();
  79
  80         if (!*user)
  81                 return false;
  82
  83         if (strequal(user,get_last_to()))
  84                 return false;
  85
  86         if (strequal(user,get_last_from())) {
  87                 DEBUG(3,("Mapped user %s to %s\n",user,get_last_to()));
  88                 fstrcpy(user,get_last_to());
  89                 return true;
  90         }
  91
  92         /* first try the username map script */
  93
  94         if ( *cmd ) {
  95                 char **qlines;
  96                 char *command = NULL;
  97                 int numlines, ret, fd;
  98
  99                 command = talloc_asprintf(talloc_tos(),
 100                                         "%s \"%s\"",
 101                                         cmd,
 102                                         user);
 103                 if (!command) {
 104                         return false;
 105                 }
 106
 107                 DEBUG(10,("Running [%s]\n", command));
 108                 ret = smbrun(command, &fd);
 109                 DEBUGADD(10,("returned [%d]\n", ret));
 110
 111                 if ( ret != 0 ) {
 112                         if (fd != -1)
 113                                 close(fd);
 114                         return False;
 115                 }
 116
 117                 numlines = 0;
 118                 qlines = fd_lines_load(fd, &numlines,0, NULL);
 119                 DEBUGADD(10,("Lines returned = [%d]\n", numlines));
 120                 close(fd);
 121
 122                 /* should be either no lines or a single line with the mapped username */
 123
 124                 if (numlines && qlines) {
 125                         DEBUG(3,("Mapped user %s to %s\n", user, qlines[0] ));
 126                         fstrcpy( user, qlines[0] );
 127                 }
 128
 129                 TALLOC_FREE(qlines);
 130
 131                 return numlines != 0;
 132         }
 133
 134         /* ok.  let's try the mapfile */
 135         if (!*mapfile)
 136                 return False;
 137
 138         f = x_fopen(mapfile,O_RDONLY, 0);
 139         if (!f) {
 140                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 141                 return False;
 142         }
 143
 144         DEBUG(4,("Scanning username map %s\n",mapfile));
 145
 146         while((s=fgets_slash(buf,sizeof(buf),f))!=NULL) {
 147                 char *unixname = s;
 148                 char *dosname = strchr_m(unixname,'=');
 149                 char **dosuserlist;
 150                 bool return_if_mapped = False;
 151
 152                 if (!dosname)
 153                         continue;
 154
 155                 *dosname++ = 0;
 156
 157                 while (isspace((int)*unixname))
 158                         unixname++;
 159
 160                 if ('!' == *unixname) {
 161                         return_if_mapped = True;
 162                         unixname++;
 163                         while (*unixname && isspace((int)*unixname))
 164                                 unixname++;
 165                 }
 166
 167                 if (!*unixname || strchr_m("#;",*unixname))
 168                         continue;
 169
 170                 {
 171                         int l = strlen(unixname);
 172                         while (l && isspace((int)unixname[l-1])) {
 173                                 unixname[l-1] = 0;
 174                                 l--;
 175                         }
 176                 }
 177
 178                 /* skip lines like 'user = ' */
 179
 180                 dosuserlist = str_list_make_v3(talloc_tos(), dosname, NULL);
 181                 if (!dosuserlist) {
 182                         DEBUG(0,("Bad username map entry.  Unable to build user list.  Ignoring.\n"));
 183                         continue;
 184                 }
 185
 186                 if (strchr_m(dosname,'*') ||
 187                     user_in_list(user, (const char **)dosuserlist)) {
 188                         DEBUG(3,("Mapped user %s to %s\n",user,unixname));
 189                         mapped_user = True;
 190
 191                         set_last_from_to(user, unixname);
 192                         fstrcpy( user, unixname );
 193
 194                         if ( return_if_mapped ) {
 195                                 TALLOC_FREE(dosuserlist);
 196                                 x_fclose(f);
 197                                 return True;
 198                         }
 199                 }
 200
 201                 TALLOC_FREE(dosuserlist);
 202         }
 203
 204         x_fclose(f);
 205
 206         /*
 207          * Setup the last_from and last_to as an optimization so
 208          * that we don't scan the file again for the same user.
 209          */
 210
 211         set_last_from_to(user, user);
 212
 213         return mapped_user;
 214 }