source3/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 userdom_struct current_user_info;
  25 fstring remote_proto="UNKNOWN";
  26
  27 /**
  28  * Set the 'local' machine name
  29  * @param local_name the name we are being called
  30  * @param if this is the 'final' name for us, not be be changed again
  31  */
  32
  33 static char *local_machine;
  34
  35 void free_local_machine_name(void)
  36 {
  37         SAFE_FREE(local_machine);
  38 }
  39
  40 bool set_local_machine_name(const char *local_name, bool perm)
  41 {
  42         static bool already_perm = false;
  43         char *tmp_local_machine = NULL;
  44         char addr[INET6_ADDRSTRLEN];
  45         size_t len;
  46
  47         tmp_local_machine = SMB_STRDUP(local_name);
  48         if (!tmp_local_machine) {
  49                 return false;
  50         }
  51         trim_char(tmp_local_machine,' ',' ');
  52
  53         /*
  54          * Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
  55          * arrggg!!!
  56          */
  57
  58         if (strequal(tmp_local_machine, "*SMBSERVER") ||
  59                         strequal(tmp_local_machine, "*SMBSERV") )  {
  60                 SAFE_FREE(local_machine);
  61                 local_machine = SMB_STRDUP(client_socket_addr(get_client_fd(),
  62                                         addr, sizeof(addr)) );
  63                 SAFE_FREE(tmp_local_machine);
  64                 return local_machine ? true : false;
  65         }
  66
  67         if (already_perm) {
  68                 return true;
  69         }
  70
  71         SAFE_FREE(local_machine);
  72         len = strlen(tmp_local_machine);
  73         local_machine = SMB_CALLOC_ARRAY(char, len+1);
  74         if (!local_machine) {
  75                 SAFE_FREE(tmp_local_machine);
  76                 return false;
  77         }
  78         /* alpha_strcpy includes the space for the terminating nul. */
  79         alpha_strcpy(local_machine,tmp_local_machine,
  80                         SAFE_NETBIOS_CHARS,len+1);
  81         strlower_m(local_machine);
  82         SAFE_FREE(tmp_local_machine);
  83
  84         already_perm = perm;
  85
  86         return true;
  87 }
  88
  89 const char *get_local_machine_name(void)
  90 {
  91         if (!local_machine || !*local_machine) {
  92                 return global_myname();
  93         }
  94
  95         return local_machine;
  96 }
  97
  98 /**
  99  * Set the 'remote' machine name
 100  * @param remote_name the name our client wants to be called by
 101  * @param if this is the 'final' name for them, not be be changed again
 102  */
 103
 104 static char *remote_machine;
 105
 106 bool set_remote_machine_name(const char *remote_name, bool perm)
 107 {
 108         static bool already_perm = False;
 109         char *tmp_remote_machine;
 110         size_t len;
 111
 112         if (already_perm) {
 113                 return true;
 114         }
 115
 116         tmp_remote_machine = SMB_STRDUP(remote_name);
 117         if (!tmp_remote_machine) {
 118                 return false;
 119         }
 120         trim_char(tmp_remote_machine,' ',' ');
 121
 122         SAFE_FREE(remote_machine);
 123         len = strlen(tmp_remote_machine);
 124         remote_machine = SMB_CALLOC_ARRAY(char, len+1);
 125         if (!remote_machine) {
 126                 SAFE_FREE(tmp_remote_machine);
 127                 return false;
 128         }
 129
 130         /* alpha_strcpy includes the space for the terminating nul. */
 131         alpha_strcpy(remote_machine,tmp_remote_machine,
 132                         SAFE_NETBIOS_CHARS,len+1);
 133         strlower_m(remote_machine);
 134         SAFE_FREE(tmp_remote_machine);
 135
 136         already_perm = perm;
 137
 138         return true;
 139 }
 140
 141 const char *get_remote_machine_name(void)
 142 {
 143         return remote_machine ? remote_machine : "";
 144 }
 145
 146 /*******************************************************************
 147  Setup the string used by %U substitution.
 148 ********************************************************************/
 149
 150 static char *smb_user_name;
 151
 152 void sub_set_smb_name(const char *name)
 153 {
 154         char *tmp;
 155         size_t len;
 156         bool is_machine_account = false;
 157
 158         /* don't let anonymous logins override the name */
 159         if (!name || !*name) {
 160                 return;
 161         }
 162
 163         tmp = SMB_STRDUP(name);
 164         if (!tmp) {
 165                 return;
 166         }
 167         trim_char(tmp, ' ', ' ');
 168         strlower_m(tmp);
 169
 170         len = strlen(tmp);
 171
 172         if (len == 0) {
 173                 SAFE_FREE(tmp);
 174                 return;
 175         }
 176
 177         /* long story but here goes....we have to allow usernames
 178            ending in '$' as they are valid machine account names.
 179            So check for a machine account and re-add the '$'
 180            at the end after the call to alpha_strcpy().   --jerry  */
 181
 182         if (tmp[len-1] == '$') {
 183                 is_machine_account = True;
 184         }
 185
 186         SAFE_FREE(smb_user_name);
 187         smb_user_name = SMB_CALLOC_ARRAY(char, len+1);
 188         if (!smb_user_name) {
 189                 SAFE_FREE(tmp);
 190                 return;
 191         }
 192
 193         /* alpha_strcpy includes the space for the terminating nul. */
 194         alpha_strcpy(smb_user_name, tmp,
 195                         SAFE_NETBIOS_CHARS,
 196                         len+1);
 197
 198         SAFE_FREE(tmp);
 199
 200         if (is_machine_account) {
 201                 len = strlen(smb_user_name);
 202                 smb_user_name[len-1] = '$';
 203         }
 204 }
 205
 206 static const char *get_smb_user_name(void)
 207 {
 208         return smb_user_name ? smb_user_name : "";
 209 }
 210
 211 /*******************************************************************
 212  Setup the strings used by substitutions. Called per packet. Ensure
 213  %U name is set correctly also.
 214
 215  smb_name must be sanitized by alpha_strcpy
 216 ********************************************************************/
 217
 218 void set_current_user_info(const char *smb_name, const char *unix_name,
 219                            const char *full_name, const char *domain)
 220 {
 221         fstrcpy(current_user_info.smb_name, smb_name);
 222         fstrcpy(current_user_info.unix_name, unix_name);
 223         fstrcpy(current_user_info.full_name, full_name);
 224         fstrcpy(current_user_info.domain, domain);
 225
 226         /* The following is safe as current_user_info.smb_name
 227          * has already been sanitised in register_existing_vuid. */
 228
 229         sub_set_smb_name(current_user_info.smb_name);
 230 }
 231
 232 /*******************************************************************
 233  Return the current active user name.
 234 *******************************************************************/
 235
 236 const char *get_current_username(void)
 237 {
 238         if (current_user_info.smb_name[0] == '\0' ) {
 239                 return get_smb_user_name();
 240         }
 241
 242         return current_user_info.smb_name;
 243 }
 244
 245 /*******************************************************************
 246  Given a pointer to a %$(NAME) in p and the whole string in str
 247  expand it as an environment variable.
 248  Return a new allocated and expanded string.
 249  Based on code by Branko Cibej <branko.cibej@hermes.si>
 250  When this is called p points at the '%' character.
 251  May substitute multiple occurrencies of the same env var.
 252 ********************************************************************/
 253
 254 static char * realloc_expand_env_var(char *str, char *p)
 255 {
 256         char *envname;
 257         char *envval;
 258         char *q, *r;
 259         int copylen;
 260
 261         if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
 262                 return str;
 263         }
 264
 265         /*
 266          * Look for the terminating ')'.
 267          */
 268
 269         if ((q = strchr_m(p,')')) == NULL) {
 270                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 271                 return str;
 272         }
 273
 274         /*
 275          * Extract the name from within the %$(NAME) string.
 276          */
 277
 278         r = p + 3;
 279         copylen = q - r;
 280
 281         /* reserve space for use later add %$() chars */
 282         if ( (envname = (char *)SMB_MALLOC(copylen + 1 + 4)) == NULL ) {
 283                 return NULL;
 284         }
 285
 286         strncpy(envname,r,copylen);
 287         envname[copylen] = '\0';
 288
 289         if ((envval = getenv(envname)) == NULL) {
 290                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 291                 SAFE_FREE(envname);
 292                 return str;
 293         }
 294
 295         /*
 296          * Copy the full %$(NAME) into envname so it
 297          * can be replaced.
 298          */
 299
 300         copylen = q + 1 - p;
 301         strncpy(envname,p,copylen);
 302         envname[copylen] = '\0';
 303         r = realloc_string_sub(str, envname, envval);
 304         SAFE_FREE(envname);
 305
 306         return r;
 307 }
 308
 309 /*******************************************************************
 310 *******************************************************************/
 311
 312 static char *longvar_domainsid( void )
 313 {
 314         DOM_SID sid;
 315         fstring tmp;
 316         char *sid_string;
 317
 318         if ( !secrets_fetch_domain_sid( lp_workgroup(), &sid ) ) {
 319                 return NULL;
 320         }
 321
 322         sid_string = SMB_STRDUP( sid_to_fstring( tmp, &sid ) );
 323
 324         if ( !sid_string ) {
 325                 DEBUG(0,("longvar_domainsid: failed to dup SID string!\n"));
 326         }
 327
 328         return sid_string;
 329 }
 330
 331 /*******************************************************************
 332 *******************************************************************/
 333
 334 struct api_longvar {
 335         const char *name;
 336         char* (*fn)( void );
 337 };
 338
 339 static struct api_longvar longvar_table[] = {
 340         { "DomainSID",          longvar_domainsid },
 341         { NULL,                 NULL }
 342 };
 343
 344 static char *get_longvar_val( const char *varname )
 345 {
 346         int i;
 347
 348         DEBUG(7,("get_longvar_val: expanding variable [%s]\n", varname));
 349
 350         for ( i=0; longvar_table[i].name; i++ ) {
 351                 if ( strequal( longvar_table[i].name, varname ) ) {
 352                         return longvar_table[i].fn();
 353                 }
 354         }
 355
 356         return NULL;
 357 }
 358
 359 /*******************************************************************
 360  Expand the long smb.conf variable names given a pointer to a %(NAME).
 361  Return the number of characters by which the pointer should be advanced.
 362  When this is called p points at the '%' character.
 363 ********************************************************************/
 364
 365 static char *realloc_expand_longvar(char *str, char *p)
 366 {
 367         fstring varname;
 368         char *value;
 369         char *q, *r;
 370         int copylen;
 371
 372         if ( p[0] != '%' || p[1] != '(' ) {
 373                 return str;
 374         }
 375
 376         /* Look for the terminating ')'.*/
 377
 378         if ((q = strchr_m(p,')')) == NULL) {
 379                 DEBUG(0,("realloc_expand_longvar: Unterminated environment variable [%s]\n", p));
 380                 return str;
 381         }
 382
 383         /* Extract the name from within the %(NAME) string.*/
 384
 385         r = p+2;
 386         copylen = MIN( (q-r), (sizeof(varname)-1) );
 387         strncpy(varname, r, copylen);
 388         varname[copylen] = '\0';
 389
 390         if ((value = get_longvar_val(varname)) == NULL) {
 391                 DEBUG(0,("realloc_expand_longvar: Variable [%s] not set.  Skipping\n", varname));
 392                 return str;
 393         }
 394
 395         /* Copy the full %(NAME) into envname so it can be replaced.*/
 396
 397         copylen = MIN( (q+1-p),(sizeof(varname)-1) );
 398         strncpy( varname, p, copylen );
 399         varname[copylen] = '\0';
 400         r = realloc_string_sub(str, varname, value);
 401         SAFE_FREE( value );
 402
 403         /* skip over the %(varname) */
 404
 405         return r;
 406 }
 407
 408 /*******************************************************************
 409  Patch from jkf@soton.ac.uk
 410  Added this to implement %p (NIS auto-map version of %H)
 411 *******************************************************************/
 412
 413 static const char *automount_path(const char *user_name)
 414 {
 415         TALLOC_CTX *ctx = talloc_tos();
 416         const char *server_path;
 417
 418         /* use the passwd entry as the default */
 419         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 420
 421         server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
 422         if (!server_path) {
 423                 return "";
 424         }
 425
 426 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 427
 428         if (lp_nis_home_map()) {
 429                 const char *home_path_start;
 430                 char *automount_value = automount_lookup(ctx, user_name);
 431
 432                 if(automount_value && strlen(automount_value) > 0) {
 433                         home_path_start = strchr_m(automount_value,':');
 434                         if (home_path_start != NULL) {
 435                                 DEBUG(5, ("NIS lookup succeeded. "
 436                                         "Home path is: %s\n",
 437                                         home_path_start ?
 438                                                 (home_path_start+1):""));
 439                                 server_path = talloc_strdup(ctx,
 440                                                         home_path_start+1);
 441                                 if (!server_path) {
 442                                         server_path = "";
 443                                 }
 444                         }
 445                 } else {
 446                         /* NIS key lookup failed: default to
 447                          * user home directory from password file */
 448                         DEBUG(5, ("NIS lookup failed. Using Home path from "
 449                         "passwd file. Home path is: %s\n", server_path ));
 450                 }
 451         }
 452 #endif
 453
 454         DEBUG(4,("Home server path: %s\n", server_path));
 455         return server_path;
 456 }
 457
 458 /*******************************************************************
 459  Patch from jkf@soton.ac.uk
 460  This is Luke's original function with the NIS lookup code
 461  moved out to a separate function.
 462 *******************************************************************/
 463
 464 static const char *automount_server(const char *user_name)
 465 {
 466         TALLOC_CTX *ctx = talloc_tos();
 467         const char *server_name;
 468         const char *local_machine_name = get_local_machine_name();
 469
 470         /* use the local machine name as the default */
 471         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 472         if (local_machine_name && *local_machine_name) {
 473                 server_name = talloc_strdup(ctx, local_machine_name);
 474         } else {
 475                 server_name = talloc_strdup(ctx, global_myname());
 476         }
 477
 478         if (!server_name) {
 479                 return "";
 480         }
 481
 482 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 483         if (lp_nis_home_map()) {
 484                 char *p;
 485                 char *srv;
 486                 char *automount_value = automount_lookup(ctx, user_name);
 487                 if (!automount_value) {
 488                         return "";
 489                 }
 490                 srv = talloc_strdup(ctx, automount_value);
 491                 if (!srv) {
 492                         return "";
 493                 }
 494                 p = strchr_m(srv, ':');
 495                 if (!p) {
 496                         return "";
 497                 }
 498                 *p = '\0';
 499                 server_name = srv;
 500                 DEBUG(5, ("NIS lookup succeeded.  Home server %s\n",
 501                                         server_name));
 502         }
 503 #endif
 504
 505         DEBUG(4,("Home server: %s\n", server_name));
 506         return server_name;
 507 }
 508
 509 /****************************************************************************
 510  Do some standard substitutions in a string.
 511  len is the length in bytes of the space allowed in string str. If zero means
 512  don't allow expansions.
 513 ****************************************************************************/
 514
 515 void standard_sub_basic(const char *smb_name, const char *domain_name,
 516                         char *str, size_t len)
 517 {
 518         char *s;
 519
 520         if ( (s = alloc_sub_basic( smb_name, domain_name, str )) != NULL ) {
 521                 strncpy( str, s, len );
 522         }
 523
 524         SAFE_FREE( s );
 525
 526 }
 527
 528 /****************************************************************************
 529  Do some standard substitutions in a string.
 530  This function will return an allocated string that have to be freed.
 531 ****************************************************************************/
 532
 533 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name,
 534                        const char *domain_name, const char *str)
 535 {
 536         char *a, *t;
 537
 538         if ( (a = alloc_sub_basic(smb_name, domain_name, str)) == NULL ) {
 539                 return NULL;
 540         }
 541         t = talloc_strdup(mem_ctx, a);
 542         SAFE_FREE(a);
 543         return t;
 544 }
 545
 546 /****************************************************************************
 547 ****************************************************************************/
 548
 549 char *alloc_sub_basic(const char *smb_name, const char *domain_name,
 550                       const char *str)
 551 {
 552         char *b, *p, *s, *r, *a_string;
 553         fstring pidstr, vnnstr;
 554         char addr[INET6_ADDRSTRLEN];
 555         const char *local_machine_name = get_local_machine_name();
 556         TALLOC_CTX *tmp_ctx = NULL;
 557
 558         /* workaround to prevent a crash while looking at bug #687 */
 559
 560         if (!str) {
 561                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 562                 return NULL;
 563         }
 564
 565         a_string = SMB_STRDUP(str);
 566         if (a_string == NULL) {
 567                 DEBUG(0, ("alloc_sub_basic: Out of memory!\n"));
 568                 return NULL;
 569         }
 570
 571         tmp_ctx = talloc_stackframe();
 572
 573         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 574
 575                 r = NULL;
 576                 b = a_string;
 577
 578                 switch (*(p+1)) {
 579                 case 'U' :
 580                         r = strdup_lower(smb_name);
 581                         if (r == NULL) {
 582                                 goto error;
 583                         }
 584                         a_string = realloc_string_sub(a_string, "%U", r);
 585                         break;
 586                 case 'G' : {
 587                         struct passwd *pass;
 588                         r = SMB_STRDUP(smb_name);
 589                         if (r == NULL) {
 590                                 goto error;
 591                         }
 592                         pass = Get_Pwnam_alloc(tmp_ctx, r);
 593                         if (pass != NULL) {
 594                                 a_string = realloc_string_sub(
 595                                         a_string, "%G",
 596                                         gidtoname(pass->pw_gid));
 597                         }
 598                         TALLOC_FREE(pass);
 599                         break;
 600                 }
 601                 case 'D' :
 602                         r = strdup_upper(domain_name);
 603                         if (r == NULL) {
 604                                 goto error;
 605                         }
 606                         a_string = realloc_string_sub(a_string, "%D", r);
 607                         break;
 608                 case 'I' : {
 609                         int offset = 0;
 610                         client_addr(get_client_fd(), addr, sizeof(addr));
 611                         if (strnequal(addr,"::ffff:",7)) {
 612                                 offset = 7;
 613                         }
 614                         a_string = realloc_string_sub(a_string, "%I",
 615                                                       addr + offset);
 616                         break;
 617                 }
 618                 case 'i':
 619                         a_string = realloc_string_sub( a_string, "%i",
 620                                         client_socket_addr(get_client_fd(), addr, sizeof(addr)) );
 621                         break;
 622                 case 'L' :
 623                         if ( StrnCaseCmp(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
 624                                 break;
 625                         }
 626                         if (local_machine_name && *local_machine_name) {
 627                                 a_string = realloc_string_sub(a_string, "%L", local_machine_name);
 628                         } else {
 629                                 a_string = realloc_string_sub(a_string, "%L", global_myname());
 630                         }
 631                         break;
 632                 case 'N':
 633                         a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
 634                         break;
 635                 case 'M' :
 636                         a_string = realloc_string_sub(a_string, "%M", client_name(get_client_fd()));
 637                         break;
 638                 case 'R' :
 639                         a_string = realloc_string_sub(a_string, "%R", remote_proto);
 640                         break;
 641                 case 'T' :
 642                         a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
 643                         break;
 644                 case 'a' :
 645                         a_string = realloc_string_sub(a_string, "%a",
 646                                         get_remote_arch_str());
 647                         break;
 648                 case 'd' :
 649                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 650                         a_string = realloc_string_sub(a_string, "%d", pidstr);
 651                         break;
 652                 case 'h' :
 653                         a_string = realloc_string_sub(a_string, "%h", myhostname());
 654                         break;
 655                 case 'm' :
 656                         a_string = realloc_string_sub(a_string, "%m",
 657                                                       remote_machine
 658                                                       ? remote_machine
 659                                                       : "");
 660                         break;
 661                 case 'v' :
 662                         a_string = realloc_string_sub(a_string, "%v", SAMBA_VERSION_STRING);
 663                         break;
 664                 case 'w' :
 665                         a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
 666                         break;
 667                 case '$' :
 668                         a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
 669                         break;
 670                 case '(':
 671                         a_string = realloc_expand_longvar( a_string, p );
 672                         break;
 673                 case 'V' :
 674                         slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
 675                         a_string = realloc_string_sub(a_string, "%V", vnnstr);
 676                         break;
 677                 default:
 678                         break;
 679                 }
 680
 681                 p++;
 682                 SAFE_FREE(r);
 683
 684                 if (a_string == NULL) {
 685                         goto done;
 686                 }
 687         }
 688
 689         goto done;
 690
 691 error:
 692         SAFE_FREE(a_string);
 693
 694 done:
 695         TALLOC_FREE(tmp_ctx);
 696         return a_string;
 697 }
 698
 699 /****************************************************************************
 700  Do some specific substitutions in a string.
 701  This function will return an allocated string that have to be freed.
 702 ****************************************************************************/
 703
 704 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 705                         const char *input_string,
 706                         const char *username,
 707                         const char *domain,
 708                         uid_t uid,
 709                         gid_t gid)
 710 {
 711         char *a_string;
 712         char *ret_string = NULL;
 713         char *b, *p, *s;
 714         TALLOC_CTX *tmp_ctx;
 715
 716         if (!(tmp_ctx = talloc_new(mem_ctx))) {
 717                 DEBUG(0, ("talloc_new failed\n"));
 718                 return NULL;
 719         }
 720
 721         a_string = talloc_strdup(tmp_ctx, input_string);
 722         if (a_string == NULL) {
 723                 DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
 724                 goto done;
 725         }
 726
 727         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 728
 729                 b = a_string;
 730
 731                 switch (*(p+1)) {
 732                 case 'U' :
 733                         a_string = talloc_string_sub(
 734                                 tmp_ctx, a_string, "%U", username);
 735                         break;
 736                 case 'u' :
 737                         a_string = talloc_string_sub(
 738                                 tmp_ctx, a_string, "%u", username);
 739                         break;
 740                 case 'G' :
 741                         if (gid != -1) {
 742                                 a_string = talloc_string_sub(
 743                                         tmp_ctx, a_string, "%G",
 744                                         gidtoname(gid));
 745                         } else {
 746                                 a_string = talloc_string_sub(
 747                                         tmp_ctx, a_string,
 748                                         "%G", "NO_GROUP");
 749                         }
 750                         break;
 751                 case 'g' :
 752                         if (gid != -1) {
 753                                 a_string = talloc_string_sub(
 754                                         tmp_ctx, a_string, "%g",
 755                                         gidtoname(gid));
 756                         } else {
 757                                 a_string = talloc_string_sub(
 758                                         tmp_ctx, a_string, "%g", "NO_GROUP");
 759                         }
 760                         break;
 761                 case 'D' :
 762                         a_string = talloc_string_sub(tmp_ctx, a_string,
 763                                                      "%D", domain);
 764                         break;
 765                 case 'N' :
 766                         a_string = talloc_string_sub(
 767                                 tmp_ctx, a_string, "%N",
 768                                 automount_server(username));
 769                         break;
 770                 default:
 771                         break;
 772                 }
 773
 774                 p++;
 775                 if (a_string == NULL) {
 776                         goto done;
 777                 }
 778         }
 779
 780         /* Watch out, using "mem_ctx" here, so all intermediate stuff goes
 781          * away with the TALLOC_FREE(tmp_ctx) further down. */
 782
 783         ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
 784
 785  done:
 786         TALLOC_FREE(tmp_ctx);
 787         return ret_string;
 788 }
 789
 790 /****************************************************************************
 791 ****************************************************************************/
 792
 793 static char *alloc_sub_advanced(const char *servicename, const char *user,
 794                          const char *connectpath, gid_t gid,
 795                          const char *smb_name, const char *domain_name,
 796                          const char *str)
 797 {
 798         char *a_string, *ret_string;
 799         char *b, *p, *s;
 800
 801         a_string = SMB_STRDUP(str);
 802         if (a_string == NULL) {
 803                 DEBUG(0, ("alloc_sub_advanced: Out of memory!\n"));
 804                 return NULL;
 805         }
 806
 807         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 808
 809                 b = a_string;
 810
 811                 switch (*(p+1)) {
 812                 case 'N' :
 813                         a_string = realloc_string_sub(a_string, "%N", automount_server(user));
 814                         break;
 815                 case 'H': {
 816                         char *h;
 817                         if ((h = get_user_home_dir(talloc_tos(), user)))
 818                                 a_string = realloc_string_sub(a_string, "%H", h);
 819                         TALLOC_FREE(h);
 820                         break;
 821                 }
 822                 case 'P':
 823                         a_string = realloc_string_sub(a_string, "%P", connectpath);
 824                         break;
 825                 case 'S':
 826                         a_string = realloc_string_sub(a_string, "%S", servicename);
 827                         break;
 828                 case 'g':
 829                         a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
 830                         break;
 831                 case 'u':
 832                         a_string = realloc_string_sub(a_string, "%u", user);
 833                         break;
 834
 835                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 836                          * server name) in standard_sub_basic as it is
 837                          * a feature for logon servers, hence uses the
 838                          * username.  The %p (NIS server path) code is
 839                          * here as it is used instead of the default
 840                          * "path =" string in [homes] and so needs the
 841                          * service name, not the username.  */
 842                 case 'p':
 843                         a_string = realloc_string_sub(a_string, "%p",
 844                                                       automount_path(servicename));
 845                         break;
 846
 847                 default:
 848                         break;
 849                 }
 850
 851                 p++;
 852                 if (a_string == NULL) {
 853                         return NULL;
 854                 }
 855         }
 856
 857         ret_string = alloc_sub_basic(smb_name, domain_name, a_string);
 858         SAFE_FREE(a_string);
 859         return ret_string;
 860 }
 861
 862 /*
 863  * This obviously is inefficient and needs to be merged into
 864  * alloc_sub_advanced...
 865  */
 866
 867 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 868                           const char *servicename, const char *user,
 869                           const char *connectpath, gid_t gid,
 870                           const char *smb_name, const char *domain_name,
 871                           const char *str)
 872 {
 873         char *a, *t;
 874
 875         if (!(a = alloc_sub_advanced(servicename, user, connectpath, gid,
 876                                      smb_name, domain_name, str))) {
 877                 return NULL;
 878         }
 879         t = talloc_strdup(mem_ctx, a);
 880         SAFE_FREE(a);
 881         return t;
 882 }
 883
 884
 885 void standard_sub_advanced(const char *servicename, const char *user,
 886                            const char *connectpath, gid_t gid,
 887                            const char *smb_name, const char *domain_name,
 888                            char *str, size_t len)
 889 {
 890         char *s;
 891
 892         s = alloc_sub_advanced(servicename, user, connectpath,
 893                                gid, smb_name, domain_name, str);
 894
 895         if ( s ) {
 896                 strncpy( str, s, len );
 897                 SAFE_FREE( s );
 898         }
 899 }
 900
 901 /****************************************************************************
 902  Do some standard substitutions in a string.
 903 ****************************************************************************/
 904
 905 char *standard_sub_conn(TALLOC_CTX *ctx, connection_struct *conn, const char *str)
 906 {
 907         return talloc_sub_advanced(ctx,
 908                                 lp_servicename(SNUM(conn)),
 909                                 conn->server_info->unix_name,
 910                                 conn->connectpath,
 911                                 conn->server_info->utok.gid,
 912                                 get_smb_user_name(),
 913                                 "",
 914                                 str);
 915 }