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, &value, NULL);
 100         TALLOC_FREE(key);
 101         if (!found) {
 102                 return false;
 103         }
 104         TALLOC_FREE(*p_user_out);
 105         *p_user_out = talloc_strdup(ctx, value);
 106         SAFE_FREE(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 netgroup user list. If at first we don't succeed,
 133  try lower case.
 134 ****************************************************************************/
 135
 136 bool user_in_netgroup(TALLOC_CTX *ctx, const char *user, const char *ngname)
 137 {
 138 #ifdef HAVE_NETGROUP
 139         static char *my_yp_domain = NULL;
 140         char *lowercase_user = NULL;
 141
 142         if (my_yp_domain == NULL) {
 143                 yp_get_default_domain(&my_yp_domain);
 144         }
 145
 146         if (my_yp_domain == NULL) {
 147                 DEBUG(5,("Unable to get default yp domain, "
 148                         "let's try without specifying it\n"));
 149         }
 150
 151         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 152                 user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 153
 154         if (innetgr(ngname, NULL, user, my_yp_domain)) {
 155                 DEBUG(5,("user_in_netgroup: Found\n"));
 156                 return true;
 157         }
 158
 159         /*
 160          * Ok, innetgr is case sensitive. Try once more with lowercase
 161          * just in case. Attempt to fix #703. JRA.
 162          */
 163         lowercase_user = talloc_strdup(ctx, user);
 164         if (!lowercase_user) {
 165                 return false;
 166         }
 167         strlower_m(lowercase_user);
 168
 169         if (strcmp(user,lowercase_user) == 0) {
 170                 /* user name was already lower case! */
 171                 return false;
 172         }
 173
 174         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 175                 lowercase_user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 176
 177         if (innetgr(ngname, NULL, lowercase_user, my_yp_domain)) {
 178                 DEBUG(5,("user_in_netgroup: Found\n"));
 179                 return true;
 180         }
 181 #endif /* HAVE_NETGROUP */
 182         return false;
 183 }
 184
 185 /****************************************************************************
 186  Check if a user is in a user list - can check combinations of UNIX
 187  and netgroup lists.
 188 ****************************************************************************/
 189
 190 bool user_in_list(TALLOC_CTX *ctx, const char *user,const char **list)
 191 {
 192         if (!list || !*list)
 193                 return False;
 194
 195         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 196
 197         while (*list) {
 198
 199                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 200                           user, *list));
 201
 202                 /*
 203                  * Check raw username.
 204                  */
 205                 if (strequal(user, *list))
 206                         return(True);
 207
 208                 /*
 209                  * Now check to see if any combination
 210                  * of UNIX and netgroups has been specified.
 211                  */
 212
 213                 if(**list == '@') {
 214                         /*
 215                          * Old behaviour. Check netgroup list
 216                          * followed by UNIX list.
 217                          */
 218                         if(user_in_netgroup(ctx, user, *list +1))
 219                                 return True;
 220                         if(user_in_group(user, *list +1))
 221                                 return True;
 222                 } else if (**list == '+') {
 223
 224                         if((*(*list +1)) == '&') {
 225                                 /*
 226                                  * Search UNIX list followed by netgroup.
 227                                  */
 228                                 if(user_in_group(user, *list +2))
 229                                         return True;
 230                                 if(user_in_netgroup(ctx, user, *list +2))
 231                                         return True;
 232
 233                         } else {
 234
 235                                 /*
 236                                  * Just search UNIX list.
 237                                  */
 238
 239                                 if(user_in_group(user, *list +1))
 240                                         return True;
 241                         }
 242
 243                 } else if (**list == '&') {
 244
 245                         if(*(*list +1) == '+') {
 246                                 /*
 247                                  * Search netgroup list followed by UNIX list.
 248                                  */
 249                                 if(user_in_netgroup(ctx, user, *list +2))
 250                                         return True;
 251                                 if(user_in_group(user, *list +2))
 252                                         return True;
 253                         } else {
 254                                 /*
 255                                  * Just search netgroup list.
 256                                  */
 257                                 if(user_in_netgroup(ctx, user, *list +1))
 258                                         return True;
 259                         }
 260                 }
 261
 262                 list++;
 263         }
 264         return(False);
 265 }
 266
 267 bool map_username(TALLOC_CTX *ctx, const char *user_in, char **p_user_out)
 268 {
 269         XFILE *f;
 270         char *mapfile = lp_username_map(talloc_tos());
 271         char *s;
 272         char buf[512];
 273         bool mapped_user = False;
 274         char *cmd = lp_username_map_script(talloc_tos());
 275
 276         *p_user_out = NULL;
 277
 278         if (!user_in)
 279                 return false;
 280
 281         /* Initially make a copy of the incoming name. */
 282         *p_user_out = talloc_strdup(ctx, user_in);
 283         if (!*p_user_out) {
 284                 return false;
 285         }
 286
 287         if (strequal(user_in,get_last_to()))
 288                 return false;
 289
 290         if (strequal(user_in,get_last_from())) {
 291                 DEBUG(3,("Mapped user %s to %s\n",user_in,get_last_to()));
 292                 TALLOC_FREE(*p_user_out);
 293                 *p_user_out = talloc_strdup(ctx, get_last_to());
 294                 return true;
 295         }
 296
 297         if (fetch_map_from_gencache(ctx, user_in, p_user_out)) {
 298                 return true;
 299         }
 300
 301         /* first try the username map script */
 302
 303         if ( *cmd ) {
 304                 char **qlines;
 305                 char *command = NULL;
 306                 int numlines, ret, fd;
 307
 308                 command = talloc_asprintf(ctx,
 309                                         "%s \"%s\"",
 310                                         cmd,
 311                                         user_in);
 312                 if (!command) {
 313                         return false;
 314                 }
 315
 316                 DEBUG(10,("Running [%s]\n", command));
 317                 ret = smbrun(command, &fd);
 318                 DEBUGADD(10,("returned [%d]\n", ret));
 319
 320                 TALLOC_FREE(command);
 321
 322                 if ( ret != 0 ) {
 323                         if (fd != -1)
 324                                 close(fd);
 325                         return False;
 326                 }
 327
 328                 numlines = 0;
 329                 qlines = fd_lines_load(fd, &numlines, 0, ctx);
 330                 DEBUGADD(10,("Lines returned = [%d]\n", numlines));
 331                 close(fd);
 332
 333                 /* should be either no lines or a single line with the mapped username */
 334
 335                 if (numlines && qlines) {
 336                         DEBUG(3,("Mapped user %s to %s\n", user_in, qlines[0] ));
 337                         set_last_from_to(user_in, qlines[0]);
 338                         store_map_in_gencache(ctx, user_in, qlines[0]);
 339                         TALLOC_FREE(*p_user_out);
 340                         *p_user_out = talloc_strdup(ctx, qlines[0]);
 341                         if (!*p_user_out) {
 342                                 return false;
 343                         }
 344                 }
 345
 346                 TALLOC_FREE(qlines);
 347
 348                 return numlines != 0;
 349         }
 350
 351         /* ok.  let's try the mapfile */
 352         if (!*mapfile)
 353                 return False;
 354
 355         f = x_fopen(mapfile,O_RDONLY, 0);
 356         if (!f) {
 357                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 358                 return False;
 359         }
 360
 361         DEBUG(4,("Scanning username map %s\n",mapfile));
 362
 363         while((s=fgets_slash(buf,sizeof(buf),f))!=NULL) {
 364                 char *unixname = s;
 365                 char *dosname = strchr_m(unixname,'=');
 366                 char **dosuserlist;
 367                 bool return_if_mapped = False;
 368
 369                 if (!dosname)
 370                         continue;
 371
 372                 *dosname++ = 0;
 373
 374                 unixname = skip_space(unixname);
 375
 376                 if ('!' == *unixname) {
 377                         return_if_mapped = True;
 378                         unixname = skip_space(unixname+1);
 379                 }
 380
 381                 if (!*unixname || strchr_m("#;",*unixname))
 382                         continue;
 383
 384                 {
 385                         int l = strlen(unixname);
 386                         while (l && isspace((int)unixname[l-1])) {
 387                                 unixname[l-1] = 0;
 388                                 l--;
 389                         }
 390                 }
 391
 392                 /* skip lines like 'user = ' */
 393
 394                 dosuserlist = str_list_make_v3(ctx, dosname, NULL);
 395                 if (!dosuserlist) {
 396                         DEBUG(0,("Bad username map entry.  Unable to build user list.  Ignoring.\n"));
 397                         continue;
 398                 }
 399
 400                 if (strchr_m(dosname,'*') ||
 401                     user_in_list(ctx, user_in, (const char **)dosuserlist)) {
 402                         DEBUG(3,("Mapped user %s to %s\n",user_in,unixname));
 403                         mapped_user = True;
 404
 405                         set_last_from_to(user_in, unixname);
 406                         store_map_in_gencache(ctx, user_in, unixname);
 407                         TALLOC_FREE(*p_user_out);
 408                         *p_user_out = talloc_strdup(ctx, unixname);
 409                         if (!*p_user_out) {
 410                                 TALLOC_FREE(dosuserlist);
 411                                 x_fclose(f);
 412                                 return false;
 413                         }
 414
 415                         if ( return_if_mapped ) {
 416                                 TALLOC_FREE(dosuserlist);
 417                                 x_fclose(f);
 418                                 return True;
 419                         }
 420                 }
 421
 422                 TALLOC_FREE(dosuserlist);
 423         }
 424
 425         x_fclose(f);
 426
 427         /*
 428          * Setup the last_from and last_to as an optimization so
 429          * that we don't scan the file again for the same user.
 430          */
 431
 432         set_last_from_to(user_in, user_in);
 433         store_map_in_gencache(ctx, user_in, user_in);
 434
 435         return mapped_user;
 436 }