source/lib/substitute.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    string substitution functions
   4    Copyright (C) Andrew Tridgell 1992-2000
   5    Copyright (C) Gerald Carter   2006
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21
  22 #include "includes.h"
  23
  24 extern struct current_user current_user;
  25
  26 userdom_struct current_user_info;
  27 fstring remote_proto="UNKNOWN";
  28
  29 /**
  30  * Set the 'local' machine name
  31  * @param local_name the name we are being called
  32  * @param if this is the 'final' name for us, not be be changed again
  33  */
  34
  35 static char *local_machine;
  36
  37 void free_local_machine_name(void)
  38 {
  39         SAFE_FREE(local_machine);
  40 }
  41
  42 bool set_local_machine_name(const char *local_name, bool perm)
  43 {
  44         static bool already_perm = false;
  45         char *tmp_local_machine = NULL;
  46         char addr[INET6_ADDRSTRLEN];
  47         size_t len;
  48
  49         tmp_local_machine = SMB_STRDUP(local_name);
  50         if (!tmp_local_machine) {
  51                 return false;
  52         }
  53         trim_char(tmp_local_machine,' ',' ');
  54
  55         /*
  56          * Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
  57          * arrggg!!!
  58          */
  59
  60         if (strequal(tmp_local_machine, "*SMBSERVER") ||
  61                         strequal(tmp_local_machine, "*SMBSERV") )  {
  62                 SAFE_FREE(local_machine);
  63                 local_machine = SMB_STRDUP(client_socket_addr(get_client_fd(),
  64                                         addr, sizeof(addr)) );
  65                 SAFE_FREE(tmp_local_machine);
  66                 return local_machine ? true : false;
  67         }
  68
  69         if (already_perm) {
  70                 return true;
  71         }
  72
  73         SAFE_FREE(local_machine);
  74         len = strlen(tmp_local_machine);
  75         local_machine = SMB_CALLOC_ARRAY(char, len+1);
  76         if (!local_machine) {
  77                 SAFE_FREE(tmp_local_machine);
  78                 return false;
  79         }
  80         /* alpha_strcpy includes the space for the terminating nul. */
  81         alpha_strcpy(local_machine,tmp_local_machine,
  82                         SAFE_NETBIOS_CHARS,len+1);
  83         strlower_m(local_machine);
  84         SAFE_FREE(tmp_local_machine);
  85
  86         already_perm = perm;
  87
  88         return true;
  89 }
  90
  91 const char *get_local_machine_name(void)
  92 {
  93         if (!local_machine || !*local_machine) {
  94                 return global_myname();
  95         }
  96
  97         return local_machine;
  98 }
  99
 100 /**
 101  * Set the 'remote' machine name
 102  * @param remote_name the name our client wants to be called by
 103  * @param if this is the 'final' name for them, not be be changed again
 104  */
 105
 106 static char *remote_machine;
 107
 108 bool set_remote_machine_name(const char *remote_name, bool perm)
 109 {
 110         static bool already_perm = False;
 111         char *tmp_remote_machine;
 112         size_t len;
 113
 114         if (already_perm) {
 115                 return true;
 116         }
 117
 118         tmp_remote_machine = SMB_STRDUP(remote_name);
 119         if (!tmp_remote_machine) {
 120                 return false;
 121         }
 122         trim_char(tmp_remote_machine,' ',' ');
 123
 124         SAFE_FREE(remote_machine);
 125         len = strlen(tmp_remote_machine);
 126         remote_machine = SMB_CALLOC_ARRAY(char, len+1);
 127         if (!remote_machine) {
 128                 SAFE_FREE(tmp_remote_machine);
 129                 return false;
 130         }
 131
 132         /* alpha_strcpy includes the space for the terminating nul. */
 133         alpha_strcpy(remote_machine,tmp_remote_machine,
 134                         SAFE_NETBIOS_CHARS,len+1);
 135         strlower_m(remote_machine);
 136         SAFE_FREE(tmp_remote_machine);
 137
 138         already_perm = perm;
 139
 140         return true;
 141 }
 142
 143 const char *get_remote_machine_name(void)
 144 {
 145         return remote_machine ? remote_machine : "";
 146 }
 147
 148 /*******************************************************************
 149  Setup the string used by %U substitution.
 150 ********************************************************************/
 151
 152 static char *smb_user_name;
 153
 154 void sub_set_smb_name(const char *name)
 155 {
 156         char *tmp;
 157         size_t len;
 158         bool is_machine_account = false;
 159
 160         /* don't let anonymous logins override the name */
 161         if (!name || !*name) {
 162                 return;
 163         }
 164
 165         tmp = SMB_STRDUP(name);
 166         if (!tmp) {
 167                 return;
 168         }
 169         trim_char(tmp, ' ', ' ');
 170         strlower_m(tmp);
 171
 172         len = strlen(tmp);
 173
 174         if (len == 0) {
 175                 SAFE_FREE(tmp);
 176                 return;
 177         }
 178
 179         /* long story but here goes....we have to allow usernames
 180            ending in '$' as they are valid machine account names.
 181            So check for a machine account and re-add the '$'
 182            at the end after the call to alpha_strcpy().   --jerry  */
 183
 184         if (tmp[len-1] == '$') {
 185                 is_machine_account = True;
 186         }
 187
 188         SAFE_FREE(smb_user_name);
 189         smb_user_name = SMB_CALLOC_ARRAY(char, len+1);
 190         if (!smb_user_name) {
 191                 SAFE_FREE(tmp);
 192                 return;
 193         }
 194
 195         /* alpha_strcpy includes the space for the terminating nul. */
 196         alpha_strcpy(smb_user_name, tmp,
 197                         SAFE_NETBIOS_CHARS,
 198                         len+1);
 199
 200         SAFE_FREE(tmp);
 201
 202         if (is_machine_account) {
 203                 len = strlen(smb_user_name);
 204                 smb_user_name[len-1] = '$';
 205         }
 206 }
 207
 208 static const char *get_smb_user_name(void)
 209 {
 210         return smb_user_name ? smb_user_name : "";
 211 }
 212
 213 /*******************************************************************
 214  Setup the strings used by substitutions. Called per packet. Ensure
 215  %U name is set correctly also.
 216 ********************************************************************/
 217
 218 void set_current_user_info(const userdom_struct *pcui)
 219 {
 220         current_user_info = *pcui;
 221         /* The following is safe as current_user_info.smb_name
 222          * has already been sanitised in register_existing_vuid. */
 223
 224         sub_set_smb_name(current_user_info.smb_name);
 225 }
 226
 227 /*******************************************************************
 228  Return the current active user name.
 229 *******************************************************************/
 230
 231 const char *get_current_username(void)
 232 {
 233         if (current_user_info.smb_name[0] == '\0' ) {
 234                 return get_smb_user_name();
 235         }
 236
 237         return current_user_info.smb_name;
 238 }
 239
 240 /*******************************************************************
 241  Given a pointer to a %$(NAME) in p and the whole string in str
 242  expand it as an environment variable.
 243  Return a new allocated and expanded string.
 244  Based on code by Branko Cibej <branko.cibej@hermes.si>
 245  When this is called p points at the '%' character.
 246  May substitute multiple occurrencies of the same env var.
 247 ********************************************************************/
 248
 249 static char * realloc_expand_env_var(char *str, char *p)
 250 {
 251         char *envname;
 252         char *envval;
 253         char *q, *r;
 254         int copylen;
 255
 256         if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
 257                 return str;
 258         }
 259
 260         /*
 261          * Look for the terminating ')'.
 262          */
 263
 264         if ((q = strchr_m(p,')')) == NULL) {
 265                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 266                 return str;
 267         }
 268
 269         /*
 270          * Extract the name from within the %$(NAME) string.
 271          */
 272
 273         r = p + 3;
 274         copylen = q - r;
 275
 276         /* reserve space for use later add %$() chars */
 277         if ( (envname = (char *)SMB_MALLOC(copylen + 1 + 4)) == NULL ) {
 278                 return NULL;
 279         }
 280
 281         strncpy(envname,r,copylen);
 282         envname[copylen] = '\0';
 283
 284         if ((envval = getenv(envname)) == NULL) {
 285                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 286                 SAFE_FREE(envname);
 287                 return str;
 288         }
 289
 290         /*
 291          * Copy the full %$(NAME) into envname so it
 292          * can be replaced.
 293          */
 294
 295         copylen = q + 1 - p;
 296         strncpy(envname,p,copylen);
 297         envname[copylen] = '\0';
 298         r = realloc_string_sub(str, envname, envval);
 299         SAFE_FREE(envname);
 300
 301         return r;
 302 }
 303
 304 /*******************************************************************
 305 *******************************************************************/
 306
 307 static char *longvar_domainsid( void )
 308 {
 309         DOM_SID sid;
 310         fstring tmp;
 311         char *sid_string;
 312
 313         if ( !secrets_fetch_domain_sid( lp_workgroup(), &sid ) ) {
 314                 return NULL;
 315         }
 316
 317         sid_string = SMB_STRDUP( sid_to_fstring( tmp, &sid ) );
 318
 319         if ( !sid_string ) {
 320                 DEBUG(0,("longvar_domainsid: failed to dup SID string!\n"));
 321         }
 322
 323         return sid_string;
 324 }
 325
 326 /*******************************************************************
 327 *******************************************************************/
 328
 329 struct api_longvar {
 330         const char *name;
 331         char* (*fn)( void );
 332 };
 333
 334 static struct api_longvar longvar_table[] = {
 335         { "DomainSID",          longvar_domainsid },
 336         { NULL,                 NULL }
 337 };
 338
 339 static char *get_longvar_val( const char *varname )
 340 {
 341         int i;
 342
 343         DEBUG(7,("get_longvar_val: expanding variable [%s]\n", varname));
 344
 345         for ( i=0; longvar_table[i].name; i++ ) {
 346                 if ( strequal( longvar_table[i].name, varname ) ) {
 347                         return longvar_table[i].fn();
 348                 }
 349         }
 350
 351         return NULL;
 352 }
 353
 354 /*******************************************************************
 355  Expand the long smb.conf variable names given a pointer to a %(NAME).
 356  Return the number of characters by which the pointer should be advanced.
 357  When this is called p points at the '%' character.
 358 ********************************************************************/
 359
 360 static char *realloc_expand_longvar(char *str, char *p)
 361 {
 362         fstring varname;
 363         char *value;
 364         char *q, *r;
 365         int copylen;
 366
 367         if ( p[0] != '%' || p[1] != '(' ) {
 368                 return str;
 369         }
 370
 371         /* Look for the terminating ')'.*/
 372
 373         if ((q = strchr_m(p,')')) == NULL) {
 374                 DEBUG(0,("realloc_expand_longvar: Unterminated environment variable [%s]\n", p));
 375                 return str;
 376         }
 377
 378         /* Extract the name from within the %(NAME) string.*/
 379
 380         r = p+2;
 381         copylen = MIN( (q-r), (sizeof(varname)-1) );
 382         strncpy(varname, r, copylen);
 383         varname[copylen] = '\0';
 384
 385         if ((value = get_longvar_val(varname)) == NULL) {
 386                 DEBUG(0,("realloc_expand_longvar: Variable [%s] not set.  Skipping\n", varname));
 387                 return str;
 388         }
 389
 390         /* Copy the full %(NAME) into envname so it can be replaced.*/
 391
 392         copylen = MIN( (q+1-p),(sizeof(varname)-1) );
 393         strncpy( varname, p, copylen );
 394         varname[copylen] = '\0';
 395         r = realloc_string_sub(str, varname, value);
 396         SAFE_FREE( value );
 397
 398         /* skip over the %(varname) */
 399
 400         return r;
 401 }
 402
 403 /*******************************************************************
 404  Patch from jkf@soton.ac.uk
 405  Added this to implement %p (NIS auto-map version of %H)
 406 *******************************************************************/
 407
 408 static const char *automount_path(const char *user_name)
 409 {
 410         TALLOC_CTX *ctx = talloc_tos();
 411         const char *server_path;
 412
 413         /* use the passwd entry as the default */
 414         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 415
 416         server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
 417         if (!server_path) {
 418                 return "";
 419         }
 420
 421 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 422
 423         if (lp_nis_home_map()) {
 424                 const char *home_path_start;
 425                 char *automount_value = automount_lookup(ctx, user_name);
 426
 427                 if(automount_value && strlen(automount_value) > 0) {
 428                         home_path_start = strchr_m(automount_value,':');
 429                         if (home_path_start != NULL) {
 430                                 DEBUG(5, ("NIS lookup succeeded. "
 431                                         "Home path is: %s\n",
 432                                         home_path_start ?
 433                                                 (home_path_start+1):""));
 434                                 server_path = talloc_strdup(ctx,
 435                                                         home_path_start+1);
 436                                 if (!server_path) {
 437                                         server_path = "";
 438                                 }
 439                         }
 440                 } else {
 441                         /* NIS key lookup failed: default to
 442                          * user home directory from password file */
 443                         DEBUG(5, ("NIS lookup failed. Using Home path from "
 444                         "passwd file. Home path is: %s\n", server_path ));
 445                 }
 446         }
 447 #endif
 448
 449         DEBUG(4,("Home server path: %s\n", server_path));
 450         return server_path;
 451 }
 452
 453 /*******************************************************************
 454  Patch from jkf@soton.ac.uk
 455  This is Luke's original function with the NIS lookup code
 456  moved out to a separate function.
 457 *******************************************************************/
 458
 459 static const char *automount_server(const char *user_name)
 460 {
 461         TALLOC_CTX *ctx = talloc_tos();
 462         const char *server_name;
 463         const char *local_machine_name = get_local_machine_name();
 464
 465         /* use the local machine name as the default */
 466         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 467         if (local_machine_name && *local_machine_name) {
 468                 server_name = talloc_strdup(ctx, local_machine_name);
 469         } else {
 470                 server_name = talloc_strdup(ctx, global_myname());
 471         }
 472
 473         if (!server_name) {
 474                 return "";
 475         }
 476
 477 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 478         if (lp_nis_home_map()) {
 479                 char *p;
 480                 char *srv;
 481                 char *automount_value = automount_lookup(ctx, user_name);
 482                 if (!automount_value) {
 483                         return "";
 484                 }
 485                 srv = talloc_strdup(ctx, automount_value);
 486                 if (!srv) {
 487                         return "";
 488                 }
 489                 p = strchr_m(srv, ':');
 490                 if (!p) {
 491                         return "";
 492                 }
 493                 *p = '\0';
 494                 server_name = srv;
 495                 DEBUG(5, ("NIS lookup succeeded.  Home server %s\n",
 496                                         server_name));
 497         }
 498 #endif
 499
 500         DEBUG(4,("Home server: %s\n", server_name));
 501         return server_name;
 502 }
 503
 504 /****************************************************************************
 505  Do some standard substitutions in a string.
 506  len is the length in bytes of the space allowed in string str. If zero means
 507  don't allow expansions.
 508 ****************************************************************************/
 509
 510 void standard_sub_basic(const char *smb_name, const char *domain_name,
 511                         char *str, size_t len)
 512 {
 513         char *s;
 514
 515         if ( (s = alloc_sub_basic( smb_name, domain_name, str )) != NULL ) {
 516                 strncpy( str, s, len );
 517         }
 518
 519         SAFE_FREE( s );
 520
 521 }
 522
 523 /****************************************************************************
 524  Do some standard substitutions in a string.
 525  This function will return an allocated string that have to be freed.
 526 ****************************************************************************/
 527
 528 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name,
 529                        const char *domain_name, const char *str)
 530 {
 531         char *a, *t;
 532
 533         if ( (a = alloc_sub_basic(smb_name, domain_name, str)) == NULL ) {
 534                 return NULL;
 535         }
 536         t = talloc_strdup(mem_ctx, a);
 537         SAFE_FREE(a);
 538         return t;
 539 }
 540
 541 /****************************************************************************
 542 ****************************************************************************/
 543
 544 char *alloc_sub_basic(const char *smb_name, const char *domain_name,
 545                       const char *str)
 546 {
 547         char *b, *p, *s, *r, *a_string;
 548         fstring pidstr, vnnstr;
 549         char addr[INET6_ADDRSTRLEN];
 550         const char *local_machine_name = get_local_machine_name();
 551         TALLOC_CTX *tmp_ctx = NULL;
 552
 553         /* workaround to prevent a crash while looking at bug #687 */
 554
 555         if (!str) {
 556                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 557                 return NULL;
 558         }
 559
 560         a_string = SMB_STRDUP(str);
 561         if (a_string == NULL) {
 562                 DEBUG(0, ("alloc_sub_basic: Out of memory!\n"));
 563                 return NULL;
 564         }
 565
 566         tmp_ctx = talloc_stackframe();
 567
 568         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 569
 570                 r = NULL;
 571                 b = a_string;
 572
 573                 switch (*(p+1)) {
 574                 case 'U' :
 575                         r = strdup_lower(smb_name);
 576                         if (r == NULL) {
 577                                 goto error;
 578                         }
 579                         a_string = realloc_string_sub(a_string, "%U", r);
 580                         break;
 581                 case 'G' : {
 582                         struct passwd *pass;
 583                         r = SMB_STRDUP(smb_name);
 584                         if (r == NULL) {
 585                                 goto error;
 586                         }
 587                         pass = Get_Pwnam_alloc(tmp_ctx, r);
 588                         if (pass != NULL) {
 589                                 a_string = realloc_string_sub(
 590                                         a_string, "%G",
 591                                         gidtoname(pass->pw_gid));
 592                         }
 593                         TALLOC_FREE(pass);
 594                         break;
 595                 }
 596                 case 'D' :
 597                         r = strdup_upper(domain_name);
 598                         if (r == NULL) {
 599                                 goto error;
 600                         }
 601                         a_string = realloc_string_sub(a_string, "%D", r);
 602                         break;
 603                 case 'I' : {
 604                         int offset = 0;
 605                         client_addr(get_client_fd(), addr, sizeof(addr));
 606                         if (strnequal(addr,"::ffff:",7)) {
 607                                 offset = 7;
 608                         }
 609                         a_string = realloc_string_sub(a_string, "%I",
 610                                                       addr + offset);
 611                         break;
 612                 }
 613                 case 'i':
 614                         a_string = realloc_string_sub( a_string, "%i",
 615                                         client_socket_addr(get_client_fd(), addr, sizeof(addr)) );
 616                         break;
 617                 case 'L' :
 618                         if ( StrnCaseCmp(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
 619                                 break;
 620                         }
 621                         if (local_machine_name && *local_machine_name) {
 622                                 a_string = realloc_string_sub(a_string, "%L", local_machine_name);
 623                         } else {
 624                                 a_string = realloc_string_sub(a_string, "%L", global_myname());
 625                         }
 626                         break;
 627                 case 'N':
 628                         a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
 629                         break;
 630                 case 'M' :
 631                         a_string = realloc_string_sub(a_string, "%M", client_name(get_client_fd()));
 632                         break;
 633                 case 'R' :
 634                         a_string = realloc_string_sub(a_string, "%R", remote_proto);
 635                         break;
 636                 case 'T' :
 637                         a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
 638                         break;
 639                 case 'a' :
 640                         a_string = realloc_string_sub(a_string, "%a",
 641                                         get_remote_arch_str());
 642                         break;
 643                 case 'd' :
 644                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 645                         a_string = realloc_string_sub(a_string, "%d", pidstr);
 646                         break;
 647                 case 'h' :
 648                         a_string = realloc_string_sub(a_string, "%h", myhostname());
 649                         break;
 650                 case 'm' :
 651                         a_string = realloc_string_sub(a_string, "%m",
 652                                                       remote_machine
 653                                                       ? remote_machine
 654                                                       : "");
 655                         break;
 656                 case 'v' :
 657                         a_string = realloc_string_sub(a_string, "%v", SAMBA_VERSION_STRING);
 658                         break;
 659                 case 'w' :
 660                         a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
 661                         break;
 662                 case '$' :
 663                         a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
 664                         break;
 665                 case '(':
 666                         a_string = realloc_expand_longvar( a_string, p );
 667                         break;
 668                 case 'V' :
 669                         slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
 670                         a_string = realloc_string_sub(a_string, "%V", vnnstr);
 671                         break;
 672                 default:
 673                         break;
 674                 }
 675
 676                 p++;
 677                 SAFE_FREE(r);
 678
 679                 if (a_string == NULL) {
 680                         goto done;
 681                 }
 682         }
 683
 684         goto done;
 685
 686 error:
 687         SAFE_FREE(a_string);
 688
 689 done:
 690         TALLOC_FREE(tmp_ctx);
 691         return a_string;
 692 }
 693
 694 /****************************************************************************
 695  Do some specific substitutions in a string.
 696  This function will return an allocated string that have to be freed.
 697 ****************************************************************************/
 698
 699 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 700                         const char *input_string,
 701                         const char *username,
 702                         const char *domain,
 703                         uid_t uid,
 704                         gid_t gid)
 705 {
 706         char *a_string;
 707         char *ret_string = NULL;
 708         char *b, *p, *s;
 709         TALLOC_CTX *tmp_ctx;
 710
 711         if (!(tmp_ctx = talloc_new(mem_ctx))) {
 712                 DEBUG(0, ("talloc_new failed\n"));
 713                 return NULL;
 714         }
 715
 716         a_string = talloc_strdup(tmp_ctx, input_string);
 717         if (a_string == NULL) {
 718                 DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
 719                 goto done;
 720         }
 721
 722         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 723
 724                 b = a_string;
 725
 726                 switch (*(p+1)) {
 727                 case 'U' :
 728                         a_string = talloc_string_sub(
 729                                 tmp_ctx, a_string, "%U", username);
 730                         break;
 731                 case 'u' :
 732                         a_string = talloc_string_sub(
 733                                 tmp_ctx, a_string, "%u", username);
 734                         break;
 735                 case 'G' :
 736                         if (gid != -1) {
 737                                 a_string = talloc_string_sub(
 738                                         tmp_ctx, a_string, "%G",
 739                                         gidtoname(gid));
 740                         } else {
 741                                 a_string = talloc_string_sub(
 742                                         tmp_ctx, a_string,
 743                                         "%G", "NO_GROUP");
 744                         }
 745                         break;
 746                 case 'g' :
 747                         if (gid != -1) {
 748                                 a_string = talloc_string_sub(
 749                                         tmp_ctx, a_string, "%g",
 750                                         gidtoname(gid));
 751                         } else {
 752                                 a_string = talloc_string_sub(
 753                                         tmp_ctx, a_string, "%g", "NO_GROUP");
 754                         }
 755                         break;
 756                 case 'D' :
 757                         a_string = talloc_string_sub(tmp_ctx, a_string,
 758                                                      "%D", domain);
 759                         break;
 760                 case 'N' :
 761                         a_string = talloc_string_sub(
 762                                 tmp_ctx, a_string, "%N",
 763                                 automount_server(username));
 764                         break;
 765                 default:
 766                         break;
 767                 }
 768
 769                 p++;
 770                 if (a_string == NULL) {
 771                         goto done;
 772                 }
 773         }
 774
 775         /* Watch out, using "mem_ctx" here, so all intermediate stuff goes
 776          * away with the TALLOC_FREE(tmp_ctx) further down. */
 777
 778         ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
 779
 780  done:
 781         TALLOC_FREE(tmp_ctx);
 782         return ret_string;
 783 }
 784
 785 /****************************************************************************
 786 ****************************************************************************/
 787
 788 static char *alloc_sub_advanced(const char *servicename, const char *user,
 789                          const char *connectpath, gid_t gid,
 790                          const char *smb_name, const char *domain_name,
 791                          const char *str)
 792 {
 793         char *a_string, *ret_string;
 794         char *b, *p, *s;
 795
 796         a_string = SMB_STRDUP(str);
 797         if (a_string == NULL) {
 798                 DEBUG(0, ("alloc_sub_advanced: Out of memory!\n"));
 799                 return NULL;
 800         }
 801
 802         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 803
 804                 b = a_string;
 805
 806                 switch (*(p+1)) {
 807                 case 'N' :
 808                         a_string = realloc_string_sub(a_string, "%N", automount_server(user));
 809                         break;
 810                 case 'H': {
 811                         char *h;
 812                         if ((h = get_user_home_dir(talloc_tos(), user)))
 813                                 a_string = realloc_string_sub(a_string, "%H", h);
 814                         TALLOC_FREE(h);
 815                         break;
 816                 }
 817                 case 'P':
 818                         a_string = realloc_string_sub(a_string, "%P", connectpath);
 819                         break;
 820                 case 'S':
 821                         a_string = realloc_string_sub(a_string, "%S", servicename);
 822                         break;
 823                 case 'g':
 824                         a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
 825                         break;
 826                 case 'u':
 827                         a_string = realloc_string_sub(a_string, "%u", user);
 828                         break;
 829
 830                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 831                          * server name) in standard_sub_basic as it is
 832                          * a feature for logon servers, hence uses the
 833                          * username.  The %p (NIS server path) code is
 834                          * here as it is used instead of the default
 835                          * "path =" string in [homes] and so needs the
 836                          * service name, not the username.  */
 837                 case 'p':
 838                         a_string = realloc_string_sub(a_string, "%p",
 839                                                       automount_path(servicename));
 840                         break;
 841
 842                 default:
 843                         break;
 844                 }
 845
 846                 p++;
 847                 if (a_string == NULL) {
 848                         return NULL;
 849                 }
 850         }
 851
 852         ret_string = alloc_sub_basic(smb_name, domain_name, a_string);
 853         SAFE_FREE(a_string);
 854         return ret_string;
 855 }
 856
 857 /*
 858  * This obviously is inefficient and needs to be merged into
 859  * alloc_sub_advanced...
 860  */
 861
 862 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 863                           const char *servicename, const char *user,
 864                           const char *connectpath, gid_t gid,
 865                           const char *smb_name, const char *domain_name,
 866                           const char *str)
 867 {
 868         char *a, *t;
 869
 870         if (!(a = alloc_sub_advanced(servicename, user, connectpath, gid,
 871                                      smb_name, domain_name, str))) {
 872                 return NULL;
 873         }
 874         t = talloc_strdup(mem_ctx, a);
 875         SAFE_FREE(a);
 876         return t;
 877 }
 878
 879
 880 void standard_sub_advanced(const char *servicename, const char *user,
 881                            const char *connectpath, gid_t gid,
 882                            const char *smb_name, const char *domain_name,
 883                            char *str, size_t len)
 884 {
 885         char *s;
 886
 887         s = alloc_sub_advanced(servicename, user, connectpath,
 888                                gid, smb_name, domain_name, str);
 889
 890         if ( s ) {
 891                 strncpy( str, s, len );
 892                 SAFE_FREE( s );
 893         }
 894 }
 895
 896 /****************************************************************************
 897  Do some standard substitutions in a string.
 898 ****************************************************************************/
 899
 900 char *standard_sub_conn(TALLOC_CTX *ctx, connection_struct *conn, const char *str)
 901 {
 902         return talloc_sub_advanced(ctx,
 903                                 lp_servicename(SNUM(conn)),
 904                                 conn->user,
 905                                 conn->connectpath,
 906                                 conn->gid,
 907                                 get_smb_user_name(),
 908                                 "",
 909                                 str);
 910 }