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
  24 /*******************************************************************
  25  Map a username from a dos name to a unix name by looking in the username
  26  map. Note that this modifies the name in place.
  27  This is the main function that should be called *once* on
  28  any incoming or new username - in order to canonicalize the name.
  29  This is being done to de-couple the case conversions from the user mapping
  30  function. Previously, the map_username was being called
  31  every time Get_Pwnam_alloc was called.
  32  Returns True if username was changed, false otherwise.
  33 ********************************************************************/
  34
  35 static char *last_from = NULL;
  36 static char *last_to = NULL;
  37
  38 static const char *get_last_from(void)
  39 {
  40         if (!last_from) {
  41                 return "";
  42         }
  43         return last_from;
  44 }
  45
  46 static const char *get_last_to(void)
  47 {
  48         if (!last_to) {
  49                 return "";
  50         }
  51         return last_to;
  52 }
  53
  54 static bool set_last_from_to(const char *from, const char *to)
  55 {
  56         char *orig_from = last_from;
  57         char *orig_to = last_to;
  58
  59         last_from = SMB_STRDUP(from);
  60         last_to = SMB_STRDUP(to);
  61
  62         SAFE_FREE(orig_from);
  63         SAFE_FREE(orig_to);
  64
  65         if (!last_from || !last_to) {
  66                 SAFE_FREE(last_from);
  67                 SAFE_FREE(last_to);
  68                 return false;
  69         }
  70         return true;
  71 }
  72
  73 static char *skip_space(char *s)
  74 {
  75         while (isspace((int)(*s))) {
  76                 s += 1;
  77         }
  78         return s;
  79 }
  80
  81 static bool fetch_map_from_gencache(TALLOC_CTX *ctx,
  82                         const char *user_in,
  83                         char **p_user_out)
  84 {
  85         char *key, *value;
  86         bool found;
  87
  88         if (lp_username_map_cache_time() == 0) {
  89                 return false;
  90         }
  91
  92         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
  93                                          user_in);
  94         if (key == NULL) {
  95                 return false;
  96         }
  97         found = gencache_get(key, &value, NULL);
  98         TALLOC_FREE(key);
  99         if (!found) {
 100                 return false;
 101         }
 102         TALLOC_FREE(*p_user_out);
 103         *p_user_out = talloc_strdup(ctx, value);
 104         if (!*p_user_out) {
 105                 return false;
 106         }
 107         return true;
 108 }
 109
 110 static void store_map_in_gencache(TALLOC_CTX *ctx, const char *from, const char *to)
 111 {
 112         char *key;
 113         int cache_time = lp_username_map_cache_time();
 114
 115         if (cache_time == 0) {
 116                 return;
 117         }
 118
 119         key = talloc_asprintf_strupper_m(ctx, "USERNAME_MAP/%s",
 120                                          from);
 121         if (key == NULL) {
 122                 return;
 123         }
 124         gencache_set(key, to, cache_time + time(NULL));
 125         TALLOC_FREE(key);
 126 }
 127
 128 /****************************************************************************
 129  Check if a user is in a netgroup user list. If at first we don't succeed,
 130  try lower case.
 131 ****************************************************************************/
 132
 133 bool user_in_netgroup(TALLOC_CTX *ctx, const char *user, const char *ngname)
 134 {
 135 #ifdef HAVE_NETGROUP
 136         static char *my_yp_domain = NULL;
 137         char *lowercase_user = NULL;
 138
 139         if (my_yp_domain == NULL) {
 140                 yp_get_default_domain(&my_yp_domain);
 141         }
 142
 143         if (my_yp_domain == NULL) {
 144                 DEBUG(5,("Unable to get default yp domain, "
 145                         "let's try without specifying it\n"));
 146         }
 147
 148         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 149                 user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 150
 151         if (innetgr(ngname, NULL, user, my_yp_domain)) {
 152                 DEBUG(5,("user_in_netgroup: Found\n"));
 153                 return true;
 154         }
 155
 156         /*
 157          * Ok, innetgr is case sensitive. Try once more with lowercase
 158          * just in case. Attempt to fix #703. JRA.
 159          */
 160         lowercase_user = talloc_strdup(ctx, user);
 161         if (!lowercase_user) {
 162                 return false;
 163         }
 164         strlower_m(lowercase_user);
 165
 166         if (strcmp(user,lowercase_user) == 0) {
 167                 /* user name was already lower case! */
 168                 return false;
 169         }
 170
 171         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 172                 lowercase_user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 173
 174         if (innetgr(ngname, NULL, lowercase_user, my_yp_domain)) {
 175                 DEBUG(5,("user_in_netgroup: Found\n"));
 176                 return true;
 177         }
 178 #endif /* HAVE_NETGROUP */
 179         return false;
 180 }
 181
 182 /****************************************************************************
 183  Check if a user is in a user list - can check combinations of UNIX
 184  and netgroup lists.
 185 ****************************************************************************/
 186
 187 bool user_in_list(TALLOC_CTX *ctx, const char *user,const char **list)
 188 {
 189         if (!list || !*list)
 190                 return False;
 191
 192         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 193
 194         while (*list) {
 195
 196                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 197                           user, *list));
 198
 199                 /*
 200                  * Check raw username.
 201                  */
 202                 if (strequal(user, *list))
 203                         return(True);
 204
 205                 /*
 206                  * Now check to see if any combination
 207                  * of UNIX and netgroups has been specified.
 208                  */
 209
 210                 if(**list == '@') {
 211                         /*
 212                          * Old behaviour. Check netgroup list
 213                          * followed by UNIX list.
 214                          */
 215                         if(user_in_netgroup(ctx, user, *list +1))
 216                                 return True;
 217                         if(user_in_group(user, *list +1))
 218                                 return True;
 219                 } else if (**list == '+') {
 220
 221                         if((*(*list +1)) == '&') {
 222                                 /*
 223                                  * Search UNIX list followed by netgroup.
 224                                  */
 225                                 if(user_in_group(user, *list +2))
 226                                         return True;
 227                                 if(user_in_netgroup(ctx, user, *list +2))
 228                                         return True;
 229
 230                         } else {
 231
 232                                 /*
 233                                  * Just search UNIX list.
 234                                  */
 235
 236                                 if(user_in_group(user, *list +1))
 237                                         return True;
 238                         }
 239
 240                 } else if (**list == '&') {
 241
 242                         if(*(*list +1) == '+') {
 243                                 /*
 244                                  * Search netgroup list followed by UNIX list.
 245                                  */
 246                                 if(user_in_netgroup(ctx, user, *list +2))
 247                                         return True;
 248                                 if(user_in_group(user, *list +2))
 249                                         return True;
 250                         } else {
 251                                 /*
 252                                  * Just search netgroup list.
 253                                  */
 254                                 if(user_in_netgroup(ctx, user, *list +1))
 255                                         return True;
 256                         }
 257                 }
 258
 259                 list++;
 260         }
 261         return(False);
 262 }
 263
 264 bool map_username(TALLOC_CTX *ctx, const char *user_in, char **p_user_out)
 265 {
 266         XFILE *f;
 267         char *mapfile = lp_username_map();
 268         char *s;
 269         char buf[512];
 270         bool mapped_user = False;
 271         char *cmd = lp_username_map_script();
 272
 273         *p_user_out = NULL;
 274
 275         if (!user_in)
 276                 return false;
 277
 278         /* Initially make a copy of the incoming name. */
 279         *p_user_out = talloc_strdup(ctx, user_in);
 280         if (!*p_user_out) {
 281                 return false;
 282         }
 283
 284         if (strequal(user_in,get_last_to()))
 285                 return false;
 286
 287         if (strequal(user_in,get_last_from())) {
 288                 DEBUG(3,("Mapped user %s to %s\n",user_in,get_last_to()));
 289                 TALLOC_FREE(*p_user_out);
 290                 *p_user_out = talloc_strdup(ctx, get_last_to());
 291                 return true;
 292         }
 293
 294         if (fetch_map_from_gencache(ctx, user_in, p_user_out)) {
 295                 return true;
 296         }
 297
 298         /* first try the username map script */
 299
 300         if ( *cmd ) {
 301                 char **qlines;
 302                 char *command = NULL;
 303                 int numlines, ret, fd;
 304
 305                 command = talloc_asprintf(ctx,
 306                                         "%s \"%s\"",
 307                                         cmd,
 308                                         user_in);
 309                 if (!command) {
 310                         return false;
 311                 }
 312
 313                 DEBUG(10,("Running [%s]\n", command));
 314                 ret = smbrun(command, &fd);
 315                 DEBUGADD(10,("returned [%d]\n", ret));
 316
 317                 TALLOC_FREE(command);
 318
 319                 if ( ret != 0 ) {
 320                         if (fd != -1)
 321                                 close(fd);
 322                         return False;
 323                 }
 324
 325                 numlines = 0;
 326                 qlines = fd_lines_load(fd, &numlines, 0, ctx);
 327                 DEBUGADD(10,("Lines returned = [%d]\n", numlines));
 328                 close(fd);
 329
 330                 /* should be either no lines or a single line with the mapped username */
 331
 332                 if (numlines && qlines) {
 333                         DEBUG(3,("Mapped user %s to %s\n", user_in, qlines[0] ));
 334                         set_last_from_to(user_in, qlines[0]);
 335                         store_map_in_gencache(ctx, user_in, qlines[0]);
 336                         TALLOC_FREE(*p_user_out);
 337                         *p_user_out = talloc_strdup(ctx, qlines[0]);
 338                         if (!*p_user_out) {
 339                                 return false;
 340                         }
 341                 }
 342
 343                 TALLOC_FREE(qlines);
 344
 345                 return numlines != 0;
 346         }
 347
 348         /* ok.  let's try the mapfile */
 349         if (!*mapfile)
 350                 return False;
 351
 352         f = x_fopen(mapfile,O_RDONLY, 0);
 353         if (!f) {
 354                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 355                 return False;
 356         }
 357
 358         DEBUG(4,("Scanning username map %s\n",mapfile));
 359
 360         while((s=fgets_slash(buf,sizeof(buf),f))!=NULL) {
 361                 char *unixname = s;
 362                 char *dosname = strchr_m(unixname,'=');
 363                 char **dosuserlist;
 364                 bool return_if_mapped = False;
 365
 366                 if (!dosname)
 367                         continue;
 368
 369                 *dosname++ = 0;
 370
 371                 unixname = skip_space(unixname);
 372
 373                 if ('!' == *unixname) {
 374                         return_if_mapped = True;
 375                         unixname = skip_space(unixname+1);
 376                 }
 377
 378                 if (!*unixname || strchr_m("#;",*unixname))
 379                         continue;
 380
 381                 {
 382                         int l = strlen(unixname);
 383                         while (l && isspace((int)unixname[l-1])) {
 384                                 unixname[l-1] = 0;
 385                                 l--;
 386                         }
 387                 }
 388
 389                 /* skip lines like 'user = ' */
 390
 391                 dosuserlist = str_list_make_v3(ctx, dosname, NULL);
 392                 if (!dosuserlist) {
 393                         DEBUG(0,("Bad username map entry.  Unable to build user list.  Ignoring.\n"));
 394                         continue;
 395                 }
 396
 397                 if (strchr_m(dosname,'*') ||
 398                     user_in_list(ctx, user_in, (const char **)dosuserlist)) {
 399                         DEBUG(3,("Mapped user %s to %s\n",user_in,unixname));
 400                         mapped_user = True;
 401
 402                         set_last_from_to(user_in, unixname);
 403                         store_map_in_gencache(ctx, user_in, unixname);
 404                         TALLOC_FREE(*p_user_out);
 405                         *p_user_out = talloc_strdup(ctx, unixname);
 406                         if (!*p_user_out) {
 407                                 TALLOC_FREE(dosuserlist);
 408                                 x_fclose(f);
 409                                 return false;
 410                         }
 411
 412                         if ( return_if_mapped ) {
 413                                 TALLOC_FREE(dosuserlist);
 414                                 x_fclose(f);
 415                                 return True;
 416                         }
 417                 }
 418
 419                 TALLOC_FREE(dosuserlist);
 420         }
 421
 422         x_fclose(f);
 423
 424         /*
 425          * Setup the last_from and last_to as an optimization so
 426          * that we don't scan the file again for the same user.
 427          */
 428
 429         set_last_from_to(user_in, user_in);
 430         store_map_in_gencache(ctx, user_in, user_in);
 431
 432         return mapped_user;
 433 }