source3/auth/user_util.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 "system/filesys.h"
  24 #include "auth.h"
  25 #include "lib/gencache.h"
  26
  27 /*******************************************************************
  28  Map a username from a dos name to a unix name by looking in the username
  29  map. Note that this modifies the name in place.
  30  This is the main function that should be called *once* on
  31  any incoming or new username - in order to canonicalize the name.
  32  This is being done to de-couple the case conversions from the user mapping
  33  function. Previously, the map_username was being called
  34  every time Get_Pwnam_alloc was called.
  35  Returns True if username was changed, false otherwise.
  36 ********************************************************************/
  37
  38 static char *last_from = NULL;
  39 static char *last_to = NULL;
  40
  41 static const char *get_last_from(void)
  42 {
  43         if (!last_from) {
  44                 return "";
  45         }
  46         return last_from;
  47 }
  48
  49 static const char *get_last_to(void)
  50 {
  51         if (!last_to) {
  52                 return "";
  53         }
  54         return last_to;
  55 }
  56
  57 static bool set_last_from_to(const char *from, const char *to)
  58 {
  59         char *orig_from = last_from;
  60         char *orig_to = last_to;
  61
  62         last_from = SMB_STRDUP(from);
  63         last_to = SMB_STRDUP(to);
  64
  65         SAFE_FREE(orig_from);
  66         SAFE_FREE(orig_to);
  67
  68         if (!last_from || !last_to) {
  69                 SAFE_FREE(last_from);
  70                 SAFE_FREE(last_to);
  71                 return false;
  72         }
  73         return true;
  74 }
  75
  76 static char *skip_space(char *s)
  77 {
  78         while (isspace((int)(*s))) {
  79                 s += 1;
  80         }
  81         return s;
  82 }
  83
  84 static bool fetch_map_from_gencache(TALLOC_CTX *ctx,
  85                         const char *user_in,
  86                         char **p_user_out)
  87 {
  88         char *key, *value;
  89         bool found;
  90
  91         if (lp_username_map_cache_time() == 0) {
  92                 return false;
  93         }
  94
  95         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
  96                                          user_in);
  97         if (key == NULL) {
  98                 return false;
  99         }
 100         found = gencache_get(key, ctx, &value, NULL);
 101         TALLOC_FREE(key);
 102         if (!found) {
 103                 return false;
 104         }
 105         TALLOC_FREE(*p_user_out);
 106         *p_user_out = value;
 107         if (!*p_user_out) {
 108                 return false;
 109         }
 110         return true;
 111 }
 112
 113 static void store_map_in_gencache(TALLOC_CTX *ctx, const char *from, const char *to)
 114 {
 115         char *key;
 116         int cache_time = lp_username_map_cache_time();
 117
 118         if (cache_time == 0) {
 119                 return;
 120         }
 121
 122         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
 123                                          from);
 124         if (key == NULL) {
 125                 return;
 126         }
 127         gencache_set(key, to, cache_time + time(NULL));
 128         TALLOC_FREE(key);
 129 }
 130
 131 /****************************************************************************
 132  Check if a user is in a user list
 133
 134  We removed NIS support in 2021, but need to keep configs working.
 135
 136  TOOD FIXME: Remove this funciton
 137 ****************************************************************************/
 138
 139 bool user_in_list(TALLOC_CTX *ctx, const char *user, const char * const *list)
 140 {
 141
 142         if (list == NULL || *list == NULL) {
 143                 return false;
 144         }
 145
 146         DBG_DEBUG("Checking user %s in list\n", user);
 147
 148         while (*list) {
 149                 const char *p = *list;
 150                 bool ok;
 151
 152                 /* Check raw username */
 153                 if (strequal(user, p)) {
 154                         return true;
 155                 }
 156
 157                 while (*p == '@' || *p == '&' || *p == '+') {
 158                         p++;
 159                 }
 160
 161                 ok = user_in_group(user, p);
 162                 if (ok) {
 163                         return true;
 164                 }
 165
 166                 list++;
 167         }
 168
 169         return false;
 170 }
 171
 172 bool map_username(TALLOC_CTX *ctx, const char *user_in, char **p_user_out)
 173 {
 174         const struct loadparm_substitution *lp_sub =
 175                 loadparm_s3_global_substitution();
 176         FILE *f;
 177         char *mapfile = lp_username_map(talloc_tos(), lp_sub);
 178         char *s;
 179         char buf[512];
 180         bool mapped_user = False;
 181         char *cmd = lp_username_map_script(talloc_tos(), lp_sub);
 182
 183         *p_user_out = NULL;
 184
 185         if (!user_in)
 186                 return false;
 187
 188         /* Initially make a copy of the incoming name. */
 189         *p_user_out = talloc_strdup(ctx, user_in);
 190         if (!*p_user_out) {
 191                 return false;
 192         }
 193
 194         if (strequal(user_in,get_last_to()))
 195                 return false;
 196
 197         if (strequal(user_in,get_last_from())) {
 198                 DEBUG(3,("Mapped user %s to %s\n",user_in,get_last_to()));
 199                 TALLOC_FREE(*p_user_out);
 200                 *p_user_out = talloc_strdup(ctx, get_last_to());
 201                 return true;
 202         }
 203
 204         if (fetch_map_from_gencache(ctx, user_in, p_user_out)) {
 205                 return true;
 206         }
 207
 208         /* first try the username map script */
 209
 210         if ( *cmd ) {
 211                 char **qlines;
 212                 char *command = NULL;
 213                 int numlines, ret, fd;
 214
 215                 command = talloc_asprintf(ctx,
 216                                         "%s \"%s\"",
 217                                         cmd,
 218                                         user_in);
 219                 if (!command) {
 220                         return false;
 221                 }
 222
 223                 DEBUG(10,("Running [%s]\n", command));
 224                 ret = smbrun(command, &fd, NULL);
 225                 DEBUGADD(10,("returned [%d]\n", ret));
 226
 227                 TALLOC_FREE(command);
 228
 229                 if ( ret != 0 ) {
 230                         if (fd != -1)
 231                                 close(fd);
 232                         return False;
 233                 }
 234
 235                 numlines = 0;
 236                 qlines = fd_lines_load(fd, &numlines, 0, ctx);
 237                 DEBUGADD(10,("Lines returned = [%d]\n", numlines));
 238                 close(fd);
 239
 240                 /* should be either no lines or a single line with the mapped username */
 241
 242                 if (numlines && qlines) {
 243                         DEBUG(3,("Mapped user %s to %s\n", user_in, qlines[0] ));
 244                         set_last_from_to(user_in, qlines[0]);
 245                         store_map_in_gencache(ctx, user_in, qlines[0]);
 246                         TALLOC_FREE(*p_user_out);
 247                         *p_user_out = talloc_strdup(ctx, qlines[0]);
 248                         if (!*p_user_out) {
 249                                 return false;
 250                         }
 251                 }
 252
 253                 TALLOC_FREE(qlines);
 254
 255                 return numlines != 0;
 256         }
 257
 258         /* ok.  let's try the mapfile */
 259         if (!*mapfile)
 260                 return False;
 261
 262         f = fopen(mapfile, "r");
 263         if (!f) {
 264                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 265                 return False;
 266         }
 267
 268         DEBUG(4,("Scanning username map %s\n",mapfile));
 269
 270         while((s=fgets_slash(NULL,buf,sizeof(buf),f))!=NULL) {
 271                 char *unixname = s;
 272                 char *dosname = strchr_m(unixname,'=');
 273                 char **dosuserlist;
 274                 bool return_if_mapped = False;
 275
 276                 if (!dosname)
 277                         continue;
 278
 279                 *dosname++ = 0;
 280
 281                 unixname = skip_space(unixname);
 282
 283                 if ('!' == *unixname) {
 284                         return_if_mapped = True;
 285                         unixname = skip_space(unixname+1);
 286                 }
 287
 288                 if (!*unixname || strchr_m("#;",*unixname))
 289                         continue;
 290
 291                 {
 292                         int l = strlen(unixname);
 293                         while (l && isspace((int)unixname[l-1])) {
 294                                 unixname[l-1] = 0;
 295                                 l--;
 296                         }
 297                 }
 298
 299                 /* skip lines like 'user = ' */
 300
 301                 dosuserlist = str_list_make_v3(ctx, dosname, NULL);
 302                 if (!dosuserlist) {
 303                         DEBUG(0,("Bad username map entry.  Unable to build user list.  Ignoring.\n"));
 304                         continue;
 305                 }
 306
 307                 if (strchr_m(dosname,'*') ||
 308                     user_in_list(ctx, user_in, (const char * const *)dosuserlist)) {
 309                         DEBUG(3,("Mapped user %s to %s\n",user_in,unixname));
 310                         mapped_user = True;
 311
 312                         set_last_from_to(user_in, unixname);
 313                         store_map_in_gencache(ctx, user_in, unixname);
 314                         TALLOC_FREE(*p_user_out);
 315                         *p_user_out = talloc_strdup(ctx, unixname);
 316                         if (!*p_user_out) {
 317                                 TALLOC_FREE(dosuserlist);
 318                                 fclose(f);
 319                                 return false;
 320                         }
 321
 322                         if ( return_if_mapped ) {
 323                                 TALLOC_FREE(dosuserlist);
 324                                 fclose(f);
 325                                 return True;
 326                         }
 327                 }
 328
 329                 TALLOC_FREE(dosuserlist);
 330         }
 331
 332         fclose(f);
 333
 334         /*
 335          * If we didn't successfully map a user in the loop above,
 336          * setup the last_from and last_to as an optimization so
 337          * that we don't scan the file again for the same user.
 338          */
 339         if (!mapped_user) {
 340                 DEBUG(8, ("The user '%s' has no mapping. "
 341                           "Skip it next time.\n", user_in));
 342                 set_last_from_to(user_in, user_in);
 343                 store_map_in_gencache(ctx, user_in, user_in);
 344         }
 345
 346         return mapped_user;
 347 }