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
  26 /*******************************************************************
  27  Map a username from a dos name to a unix name by looking in the username
  28  map. Note that this modifies the name in place.
  29  This is the main function that should be called *once* on
  30  any incoming or new username - in order to canonicalize the name.
  31  This is being done to de-couple the case conversions from the user mapping
  32  function. Previously, the map_username was being called
  33  every time Get_Pwnam_alloc was called.
  34  Returns True if username was changed, false otherwise.
  35 ********************************************************************/
  36
  37 static char *last_from = NULL;
  38 static char *last_to = NULL;
  39
  40 static const char *get_last_from(void)
  41 {
  42         if (!last_from) {
  43                 return "";
  44         }
  45         return last_from;
  46 }
  47
  48 static const char *get_last_to(void)
  49 {
  50         if (!last_to) {
  51                 return "";
  52         }
  53         return last_to;
  54 }
  55
  56 static bool set_last_from_to(const char *from, const char *to)
  57 {
  58         char *orig_from = last_from;
  59         char *orig_to = last_to;
  60
  61         last_from = SMB_STRDUP(from);
  62         last_to = SMB_STRDUP(to);
  63
  64         SAFE_FREE(orig_from);
  65         SAFE_FREE(orig_to);
  66
  67         if (!last_from || !last_to) {
  68                 SAFE_FREE(last_from);
  69                 SAFE_FREE(last_to);
  70                 return false;
  71         }
  72         return true;
  73 }
  74
  75 static char *skip_space(char *s)
  76 {
  77         while (isspace((int)(*s))) {
  78                 s += 1;
  79         }
  80         return s;
  81 }
  82
  83 static bool fetch_map_from_gencache(TALLOC_CTX *ctx,
  84                         const char *user_in,
  85                         char **p_user_out)
  86 {
  87         char *key, *value;
  88         bool found;
  89
  90         if (lp_username_map_cache_time() == 0) {
  91                 return false;
  92         }
  93
  94         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
  95                                          user_in);
  96         if (key == NULL) {
  97                 return false;
  98         }
  99         found = gencache_get(key, ctx, &value, NULL);
 100         TALLOC_FREE(key);
 101         if (!found) {
 102                 return false;
 103         }
 104         TALLOC_FREE(*p_user_out);
 105         *p_user_out = value;
 106         if (!*p_user_out) {
 107                 return false;
 108         }
 109         return true;
 110 }
 111
 112 static void store_map_in_gencache(TALLOC_CTX *ctx, const char *from, const char *to)
 113 {
 114         char *key;
 115         int cache_time = lp_username_map_cache_time();
 116
 117         if (cache_time == 0) {
 118                 return;
 119         }
 120
 121         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
 122                                          from);
 123         if (key == NULL) {
 124                 return;
 125         }
 126         gencache_set(key, to, cache_time + time(NULL));
 127         TALLOC_FREE(key);
 128 }
 129
 130 /****************************************************************************
 131  Check if a user is in a netgroup user list. If at first we don't succeed,
 132  try lower case.
 133 ****************************************************************************/
 134
 135 bool user_in_netgroup(TALLOC_CTX *ctx, const char *user, const char *ngname)
 136 {
 137 #ifdef HAVE_NETGROUP
 138         static char *my_yp_domain = NULL;
 139         char *lowercase_user = NULL;
 140
 141         if (my_yp_domain == NULL) {
 142                 yp_get_default_domain(&my_yp_domain);
 143         }
 144
 145         if (my_yp_domain == NULL) {
 146                 DEBUG(5,("Unable to get default yp domain, "
 147                         "let's try without specifying it\n"));
 148         }
 149
 150         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 151                 user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 152
 153         if (innetgr(ngname, NULL, user, my_yp_domain)) {
 154                 DEBUG(5,("user_in_netgroup: Found\n"));
 155                 return true;
 156         }
 157
 158         /*
 159          * Ok, innetgr is case sensitive. Try once more with lowercase
 160          * just in case. Attempt to fix #703. JRA.
 161          */
 162         lowercase_user = talloc_strdup(ctx, user);
 163         if (!lowercase_user) {
 164                 return false;
 165         }
 166         if (!strlower_m(lowercase_user)) {
 167                 return false;
 168         }
 169
 170         if (strcmp(user,lowercase_user) == 0) {
 171                 /* user name was already lower case! */
 172                 return false;
 173         }
 174
 175         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 176                 lowercase_user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 177
 178         if (innetgr(ngname, NULL, lowercase_user, my_yp_domain)) {
 179                 DEBUG(5,("user_in_netgroup: Found\n"));
 180                 return true;
 181         }
 182 #endif /* HAVE_NETGROUP */
 183         return false;
 184 }
 185
 186 /****************************************************************************
 187  Check if a user is in a user list - can check combinations of UNIX
 188  and netgroup lists.
 189 ****************************************************************************/
 190
 191 bool user_in_list(TALLOC_CTX *ctx, const char *user, const char * const *list)
 192 {
 193         if (!list || !*list)
 194                 return False;
 195
 196         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 197
 198         while (*list) {
 199
 200                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 201                           user, *list));
 202
 203                 /*
 204                  * Check raw username.
 205                  */
 206                 if (strequal(user, *list))
 207                         return(True);
 208
 209                 /*
 210                  * Now check to see if any combination
 211                  * of UNIX and netgroups has been specified.
 212                  */
 213
 214                 if(**list == '@') {
 215                         /*
 216                          * Old behaviour. Check netgroup list
 217                          * followed by UNIX list.
 218                          */
 219                         if(user_in_netgroup(ctx, user, *list +1))
 220                                 return True;
 221                         if(user_in_group(user, *list +1))
 222                                 return True;
 223                 } else if (**list == '+') {
 224
 225                         if((*(*list +1)) == '&') {
 226                                 /*
 227                                  * Search UNIX list followed by netgroup.
 228                                  */
 229                                 if(user_in_group(user, *list +2))
 230                                         return True;
 231                                 if(user_in_netgroup(ctx, user, *list +2))
 232                                         return True;
 233
 234                         } else {
 235
 236                                 /*
 237                                  * Just search UNIX list.
 238                                  */
 239
 240                                 if(user_in_group(user, *list +1))
 241                                         return True;
 242                         }
 243
 244                 } else if (**list == '&') {
 245
 246                         if(*(*list +1) == '+') {
 247                                 /*
 248                                  * Search netgroup list followed by UNIX list.
 249                                  */
 250                                 if(user_in_netgroup(ctx, user, *list +2))
 251                                         return True;
 252                                 if(user_in_group(user, *list +2))
 253                                         return True;
 254                         } else {
 255                                 /*
 256                                  * Just search netgroup list.
 257                                  */
 258                                 if(user_in_netgroup(ctx, user, *list +1))
 259                                         return True;
 260                         }
 261                 }
 262
 263                 list++;
 264         }
 265         return(False);
 266 }
 267
 268 bool map_username(TALLOC_CTX *ctx, const char *user_in, char **p_user_out)
 269 {
 270         XFILE *f;
 271         char *mapfile = lp_username_map(talloc_tos());
 272         char *s;
 273         char buf[512];
 274         bool mapped_user = False;
 275         char *cmd = lp_username_map_script(talloc_tos());
 276
 277         *p_user_out = NULL;
 278
 279         if (!user_in)
 280                 return false;
 281
 282         /* Initially make a copy of the incoming name. */
 283         *p_user_out = talloc_strdup(ctx, user_in);
 284         if (!*p_user_out) {
 285                 return false;
 286         }
 287
 288         if (strequal(user_in,get_last_to()))
 289                 return false;
 290
 291         if (strequal(user_in,get_last_from())) {
 292                 DEBUG(3,("Mapped user %s to %s\n",user_in,get_last_to()));
 293                 TALLOC_FREE(*p_user_out);
 294                 *p_user_out = talloc_strdup(ctx, get_last_to());
 295                 return true;
 296         }
 297
 298         if (fetch_map_from_gencache(ctx, user_in, p_user_out)) {
 299                 return true;
 300         }
 301
 302         /* first try the username map script */
 303
 304         if ( *cmd ) {
 305                 char **qlines;
 306                 char *command = NULL;
 307                 int numlines, ret, fd;
 308
 309                 command = talloc_asprintf(ctx,
 310                                         "%s \"%s\"",
 311                                         cmd,
 312                                         user_in);
 313                 if (!command) {
 314                         return false;
 315                 }
 316
 317                 DEBUG(10,("Running [%s]\n", command));
 318                 ret = smbrun(command, &fd);
 319                 DEBUGADD(10,("returned [%d]\n", ret));
 320
 321                 TALLOC_FREE(command);
 322
 323                 if ( ret != 0 ) {
 324                         if (fd != -1)
 325                                 close(fd);
 326                         return False;
 327                 }
 328
 329                 numlines = 0;
 330                 qlines = fd_lines_load(fd, &numlines, 0, ctx);
 331                 DEBUGADD(10,("Lines returned = [%d]\n", numlines));
 332                 close(fd);
 333
 334                 /* should be either no lines or a single line with the mapped username */
 335
 336                 if (numlines && qlines) {
 337                         DEBUG(3,("Mapped user %s to %s\n", user_in, qlines[0] ));
 338                         set_last_from_to(user_in, qlines[0]);
 339                         store_map_in_gencache(ctx, user_in, qlines[0]);
 340                         TALLOC_FREE(*p_user_out);
 341                         *p_user_out = talloc_strdup(ctx, qlines[0]);
 342                         if (!*p_user_out) {
 343                                 return false;
 344                         }
 345                 }
 346
 347                 TALLOC_FREE(qlines);
 348
 349                 return numlines != 0;
 350         }
 351
 352         /* ok.  let's try the mapfile */
 353         if (!*mapfile)
 354                 return False;
 355
 356         f = x_fopen(mapfile,O_RDONLY, 0);
 357         if (!f) {
 358                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 359                 return False;
 360         }
 361
 362         DEBUG(4,("Scanning username map %s\n",mapfile));
 363
 364         while((s=fgets_slash(buf,sizeof(buf),f))!=NULL) {
 365                 char *unixname = s;
 366                 char *dosname = strchr_m(unixname,'=');
 367                 char **dosuserlist;
 368                 bool return_if_mapped = False;
 369
 370                 if (!dosname)
 371                         continue;
 372
 373                 *dosname++ = 0;
 374
 375                 unixname = skip_space(unixname);
 376
 377                 if ('!' == *unixname) {
 378                         return_if_mapped = True;
 379                         unixname = skip_space(unixname+1);
 380                 }
 381
 382                 if (!*unixname || strchr_m("#;",*unixname))
 383                         continue;
 384
 385                 {
 386                         int l = strlen(unixname);
 387                         while (l && isspace((int)unixname[l-1])) {
 388                                 unixname[l-1] = 0;
 389                                 l--;
 390                         }
 391                 }
 392
 393                 /* skip lines like 'user = ' */
 394
 395                 dosuserlist = str_list_make_v3(ctx, dosname, NULL);
 396                 if (!dosuserlist) {
 397                         DEBUG(0,("Bad username map entry.  Unable to build user list.  Ignoring.\n"));
 398                         continue;
 399                 }
 400
 401                 if (strchr_m(dosname,'*') ||
 402                     user_in_list(ctx, user_in, (const char * const *)dosuserlist)) {
 403                         DEBUG(3,("Mapped user %s to %s\n",user_in,unixname));
 404                         mapped_user = True;
 405
 406                         set_last_from_to(user_in, unixname);
 407                         store_map_in_gencache(ctx, user_in, unixname);
 408                         TALLOC_FREE(*p_user_out);
 409                         *p_user_out = talloc_strdup(ctx, unixname);
 410                         if (!*p_user_out) {
 411                                 TALLOC_FREE(dosuserlist);
 412                                 x_fclose(f);
 413                                 return false;
 414                         }
 415
 416                         if ( return_if_mapped ) {
 417                                 TALLOC_FREE(dosuserlist);
 418                                 x_fclose(f);
 419                                 return True;
 420                         }
 421                 }
 422
 423                 TALLOC_FREE(dosuserlist);
 424         }
 425
 426         x_fclose(f);
 427
 428         /*
 429          * If we didn't successfully map a user in the loop above,
 430          * setup the last_from and last_to as an optimization so
 431          * that we don't scan the file again for the same user.
 432          */
 433         if (!mapped_user) {
 434                 DEBUG(8, ("The user '%s' has no mapping. "
 435                           "Skip it next time.\n", user_in));
 436                 set_last_from_to(user_in, user_in);
 437                 store_map_in_gencache(ctx, user_in, user_in);
 438         }
 439
 440         return mapped_user;
 441 }