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 #include "system/passwd.h"
  24 #include "secrets.h"
  25 #include "auth.h"
  26
  27 userdom_struct current_user_info;
  28 fstring remote_proto="UNKNOWN";
  29
  30 /**
  31  * Set the 'local' machine name
  32  * @param local_name the name we are being called
  33  * @param if this is the 'final' name for us, not be be changed again
  34  */
  35
  36 static char *local_machine;
  37
  38 void free_local_machine_name(void)
  39 {
  40         TALLOC_FREE(local_machine);
  41 }
  42
  43 bool set_local_machine_name(const char *local_name, bool perm)
  44 {
  45         static bool already_perm = false;
  46         char *tmp_local_machine = NULL;
  47         size_t len;
  48
  49         if (already_perm) {
  50                 return true;
  51         }
  52
  53         tmp_local_machine = talloc_strdup(NULL, local_name);
  54         if (!tmp_local_machine) {
  55                 return false;
  56         }
  57         trim_char(tmp_local_machine,' ',' ');
  58
  59         TALLOC_FREE(local_machine);
  60         len = strlen(tmp_local_machine);
  61         local_machine = (char *)TALLOC_ZERO(NULL, len+1);
  62         if (!local_machine) {
  63                 TALLOC_FREE(tmp_local_machine);
  64                 return false;
  65         }
  66         /* alpha_strcpy includes the space for the terminating nul. */
  67         alpha_strcpy(local_machine,tmp_local_machine,
  68                         SAFE_NETBIOS_CHARS,len+1);
  69         if (!strlower_m(local_machine)) {
  70                 TALLOC_FREE(tmp_local_machine);
  71                 return false;
  72         }
  73         TALLOC_FREE(tmp_local_machine);
  74
  75         already_perm = perm;
  76
  77         return true;
  78 }
  79
  80 const char *get_local_machine_name(void)
  81 {
  82         if (!local_machine || !*local_machine) {
  83                 return lp_netbios_name();
  84         }
  85
  86         return local_machine;
  87 }
  88
  89 /**
  90  * Set the 'remote' machine name
  91  * @param remote_name the name our client wants to be called by
  92  * @param if this is the 'final' name for them, not be be changed again
  93  */
  94
  95 static char *remote_machine;
  96
  97 bool set_remote_machine_name(const char *remote_name, bool perm)
  98 {
  99         static bool already_perm = False;
 100         char *tmp_remote_machine;
 101         size_t len;
 102
 103         if (already_perm) {
 104                 return true;
 105         }
 106
 107         tmp_remote_machine = talloc_strdup(NULL, remote_name);
 108         if (!tmp_remote_machine) {
 109                 return false;
 110         }
 111         trim_char(tmp_remote_machine,' ',' ');
 112
 113         TALLOC_FREE(remote_machine);
 114         len = strlen(tmp_remote_machine);
 115         remote_machine = (char *)TALLOC_ZERO(NULL, len+1);
 116         if (!remote_machine) {
 117                 TALLOC_FREE(tmp_remote_machine);
 118                 return false;
 119         }
 120
 121         /* alpha_strcpy includes the space for the terminating nul. */
 122         alpha_strcpy(remote_machine,tmp_remote_machine,
 123                         SAFE_NETBIOS_CHARS,len+1);
 124         if (!strlower_m(remote_machine)) {
 125                 TALLOC_FREE(tmp_remote_machine);
 126                 return false;
 127         }
 128         TALLOC_FREE(tmp_remote_machine);
 129
 130         already_perm = perm;
 131
 132         return true;
 133 }
 134
 135 const char *get_remote_machine_name(void)
 136 {
 137         return remote_machine ? remote_machine : "";
 138 }
 139
 140 /*******************************************************************
 141  Setup the string used by %U substitution.
 142 ********************************************************************/
 143
 144 static char *smb_user_name;
 145
 146 void sub_set_smb_name(const char *name)
 147 {
 148         char *tmp;
 149         size_t len;
 150         bool is_machine_account = false;
 151
 152         /* don't let anonymous logins override the name */
 153         if (!name || !*name) {
 154                 return;
 155         }
 156
 157         tmp = talloc_strdup(NULL, name);
 158         if (!tmp) {
 159                 return;
 160         }
 161         trim_char(tmp, ' ', ' ');
 162         if (!strlower_m(tmp)) {
 163                 TALLOC_FREE(tmp);
 164                 return;
 165         }
 166
 167         len = strlen(tmp);
 168
 169         if (len == 0) {
 170                 TALLOC_FREE(tmp);
 171                 return;
 172         }
 173
 174         /* long story but here goes....we have to allow usernames
 175            ending in '$' as they are valid machine account names.
 176            So check for a machine account and re-add the '$'
 177            at the end after the call to alpha_strcpy().   --jerry  */
 178
 179         if (tmp[len-1] == '$') {
 180                 is_machine_account = True;
 181         }
 182
 183         TALLOC_FREE(smb_user_name);
 184         smb_user_name = (char *)TALLOC_ZERO(NULL, len+1);
 185         if (!smb_user_name) {
 186                 TALLOC_FREE(tmp);
 187                 return;
 188         }
 189
 190         /* alpha_strcpy includes the space for the terminating nul. */
 191         alpha_strcpy(smb_user_name, tmp,
 192                         SAFE_NETBIOS_CHARS,
 193                         len+1);
 194
 195         TALLOC_FREE(tmp);
 196
 197         if (is_machine_account) {
 198                 len = strlen(smb_user_name);
 199                 smb_user_name[len-1] = '$';
 200         }
 201 }
 202
 203 static char sub_peeraddr[INET6_ADDRSTRLEN];
 204 static const char *sub_peername = NULL;
 205 static char sub_sockaddr[INET6_ADDRSTRLEN];
 206
 207 void sub_set_socket_ids(const char *peeraddr, const char *peername,
 208                         const char *sockaddr)
 209 {
 210         const char *addr = peeraddr;
 211
 212         if (strnequal(addr, "::ffff:", 7)) {
 213                 addr += 7;
 214         }
 215         strlcpy(sub_peeraddr, addr, sizeof(sub_peeraddr));
 216
 217         if (sub_peername != NULL &&
 218                         sub_peername != sub_peeraddr) {
 219                 talloc_free(discard_const_p(char,sub_peername));
 220                 sub_peername = NULL;
 221         }
 222         sub_peername = talloc_strdup(NULL, peername);
 223         if (sub_peername == NULL) {
 224                 sub_peername = sub_peeraddr;
 225         }
 226
 227         /*
 228          * Shouldn't we do the ::ffff: cancellation here as well? The
 229          * original code in talloc_sub_basic() did not do it, so I'm
 230          * leaving it out here as well for compatibility.
 231          */
 232         strlcpy(sub_sockaddr, sockaddr, sizeof(sub_sockaddr));
 233 }
 234
 235 static const char *get_smb_user_name(void)
 236 {
 237         return smb_user_name ? smb_user_name : "";
 238 }
 239
 240 /*******************************************************************
 241  Setup the strings used by substitutions. Called per packet. Ensure
 242  %U name is set correctly also.
 243
 244  smb_name must be sanitized by alpha_strcpy
 245 ********************************************************************/
 246
 247 void set_current_user_info(const char *smb_name, const char *unix_name,
 248                            const char *domain)
 249 {
 250         fstrcpy(current_user_info.smb_name, smb_name);
 251         fstrcpy(current_user_info.unix_name, unix_name);
 252         fstrcpy(current_user_info.domain, domain);
 253
 254         /* The following is safe as current_user_info.smb_name
 255          * has already been sanitised in register_existing_vuid. */
 256
 257         sub_set_smb_name(current_user_info.smb_name);
 258 }
 259
 260 /*******************************************************************
 261  Return the current active user name.
 262 *******************************************************************/
 263
 264 const char *get_current_username(void)
 265 {
 266         if (current_user_info.smb_name[0] == '\0' ) {
 267                 return get_smb_user_name();
 268         }
 269
 270         return current_user_info.smb_name;
 271 }
 272
 273 /*******************************************************************
 274  Given a pointer to a %$(NAME) in p and the whole string in str
 275  expand it as an environment variable.
 276  str must be a talloced string.
 277  Return a new allocated and expanded string.
 278  Based on code by Branko Cibej <branko.cibej@hermes.si>
 279  When this is called p points at the '%' character.
 280  May substitute multiple occurrencies of the same env var.
 281 ********************************************************************/
 282
 283 static char *realloc_expand_env_var(char *str, char *p)
 284 {
 285         char *envname;
 286         char *envval;
 287         char *q, *r;
 288         int copylen;
 289
 290         if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
 291                 return str;
 292         }
 293
 294         /*
 295          * Look for the terminating ')'.
 296          */
 297
 298         if ((q = strchr_m(p,')')) == NULL) {
 299                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 300                 return str;
 301         }
 302
 303         /*
 304          * Extract the name from within the %$(NAME) string.
 305          */
 306
 307         r = p + 3;
 308         copylen = q - r;
 309
 310         /* reserve space for use later add %$() chars */
 311         if ( (envname = talloc_array(talloc_tos(), char, copylen + 1 + 4)) == NULL ) {
 312                 return NULL;
 313         }
 314
 315         strncpy(envname,r,copylen);
 316         envname[copylen] = '\0';
 317
 318         if ((envval = getenv(envname)) == NULL) {
 319                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 320                 TALLOC_FREE(envname);
 321                 return str;
 322         }
 323
 324         /*
 325          * Copy the full %$(NAME) into envname so it
 326          * can be replaced.
 327          */
 328
 329         copylen = q + 1 - p;
 330         strncpy(envname,p,copylen);
 331         envname[copylen] = '\0';
 332         r = realloc_string_sub(str, envname, envval);
 333         TALLOC_FREE(envname);
 334
 335         return r;
 336 }
 337
 338 /*******************************************************************
 339  Patch from jkf@soton.ac.uk
 340  Added this to implement %p (NIS auto-map version of %H)
 341 *******************************************************************/
 342
 343 static const char *automount_path(const char *user_name)
 344 {
 345         TALLOC_CTX *ctx = talloc_tos();
 346         const char *server_path;
 347
 348         /* use the passwd entry as the default */
 349         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 350
 351         server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
 352         if (!server_path) {
 353                 return "";
 354         }
 355
 356 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 357
 358         if (lp_nis_homedir()) {
 359                 const char *home_path_start;
 360                 char *automount_value = automount_lookup(ctx, user_name);
 361
 362                 if(automount_value && strlen(automount_value) > 0) {
 363                         home_path_start = strchr_m(automount_value,':');
 364                         if (home_path_start != NULL) {
 365                                 DEBUG(5, ("NIS lookup succeeded. "
 366                                         "Home path is: %s\n",
 367                                         home_path_start ?
 368                                                 (home_path_start+1):""));
 369                                 server_path = talloc_strdup(ctx,
 370                                                         home_path_start+1);
 371                                 if (!server_path) {
 372                                         server_path = "";
 373                                 }
 374                         }
 375                 } else {
 376                         /* NIS key lookup failed: default to
 377                          * user home directory from password file */
 378                         DEBUG(5, ("NIS lookup failed. Using Home path from "
 379                         "passwd file. Home path is: %s\n", server_path ));
 380                 }
 381         }
 382 #endif
 383
 384         DEBUG(4,("Home server path: %s\n", server_path));
 385         return server_path;
 386 }
 387
 388 /*******************************************************************
 389  Patch from jkf@soton.ac.uk
 390  This is Luke's original function with the NIS lookup code
 391  moved out to a separate function.
 392 *******************************************************************/
 393
 394 static const char *automount_server(const char *user_name)
 395 {
 396         TALLOC_CTX *ctx = talloc_tos();
 397         const char *server_name;
 398         const char *local_machine_name = get_local_machine_name();
 399
 400         /* use the local machine name as the default */
 401         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 402         if (local_machine_name && *local_machine_name) {
 403                 server_name = talloc_strdup(ctx, local_machine_name);
 404         } else {
 405                 server_name = talloc_strdup(ctx, lp_netbios_name());
 406         }
 407
 408         if (!server_name) {
 409                 return "";
 410         }
 411
 412 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 413         if (lp_nis_homedir()) {
 414                 char *p;
 415                 char *srv;
 416                 char *automount_value = automount_lookup(ctx, user_name);
 417                 if (!automount_value) {
 418                         return "";
 419                 }
 420                 srv = talloc_strdup(ctx, automount_value);
 421                 if (!srv) {
 422                         return "";
 423                 }
 424                 p = strchr_m(srv, ':');
 425                 if (!p) {
 426                         return "";
 427                 }
 428                 *p = '\0';
 429                 server_name = srv;
 430                 DEBUG(5, ("NIS lookup succeeded.  Home server %s\n",
 431                                         server_name));
 432         }
 433 #endif
 434
 435         DEBUG(4,("Home server: %s\n", server_name));
 436         return server_name;
 437 }
 438
 439 /****************************************************************************
 440  Do some standard substitutions in a string.
 441  len is the length in bytes of the space allowed in string str. If zero means
 442  don't allow expansions.
 443 ****************************************************************************/
 444
 445 void standard_sub_basic(const char *smb_name, const char *domain_name,
 446                         char *str, size_t len)
 447 {
 448         char *s;
 449
 450         if ( (s = talloc_sub_basic(talloc_tos(), smb_name, domain_name, str )) != NULL ) {
 451                 strncpy( str, s, len );
 452         }
 453
 454         TALLOC_FREE( s );
 455 }
 456
 457 /****************************************************************************
 458  Do some standard substitutions in a string.
 459  This function will return an talloced string that has to be freed.
 460 ****************************************************************************/
 461
 462 char *talloc_sub_basic(TALLOC_CTX *mem_ctx,
 463                         const char *smb_name,
 464                         const char *domain_name,
 465                         const char *str)
 466 {
 467         char *b, *p, *s, *r, *a_string;
 468         fstring pidstr, vnnstr;
 469         const char *local_machine_name = get_local_machine_name();
 470         TALLOC_CTX *tmp_ctx = NULL;
 471
 472         /* workaround to prevent a crash while looking at bug #687 */
 473
 474         if (!str) {
 475                 DEBUG(0,("talloc_sub_basic: NULL source string!  This should not happen\n"));
 476                 return NULL;
 477         }
 478
 479         a_string = talloc_strdup(mem_ctx, str);
 480         if (a_string == NULL) {
 481                 DEBUG(0, ("talloc_sub_basic: Out of memory!\n"));
 482                 return NULL;
 483         }
 484
 485         tmp_ctx = talloc_stackframe();
 486
 487         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 488
 489                 r = NULL;
 490                 b = a_string;
 491
 492                 switch (*(p+1)) {
 493                 case 'U' :
 494                         r = strlower_talloc(tmp_ctx, smb_name);
 495                         if (r == NULL) {
 496                                 goto error;
 497                         }
 498                         a_string = realloc_string_sub(a_string, "%U", r);
 499                         break;
 500                 case 'G' : {
 501                         struct passwd *pass;
 502                         bool is_domain_name = false;
 503                         const char *sep = lp_winbind_separator();
 504
 505                         if (domain_name != NULL && domain_name[0] != '\0' &&
 506                             (lp_security() == SEC_ADS ||
 507                              lp_security() == SEC_DOMAIN)) {
 508                                 r = talloc_asprintf(tmp_ctx,
 509                                                     "%s%c%s",
 510                                                     domain_name,
 511                                                     *sep,
 512                                                     smb_name);
 513                                 is_domain_name = true;
 514                         } else {
 515                                 r = talloc_strdup(tmp_ctx, smb_name);
 516                         }
 517                         if (r == NULL) {
 518                                 goto error;
 519                         }
 520
 521                         pass = Get_Pwnam_alloc(tmp_ctx, r);
 522                         if (pass != NULL) {
 523                                 char *group_name;
 524
 525                                 group_name = gidtoname(pass->pw_gid);
 526                                 if (is_domain_name) {
 527                                         p = strchr_m(group_name, *sep);
 528                                         if (p != NULL) {
 529                                                 group_name = p + 1;
 530                                         }
 531                                 }
 532                                 a_string = realloc_string_sub(a_string,
 533                                                               "%G",
 534                                                               group_name);
 535                         }
 536                         TALLOC_FREE(pass);
 537                         break;
 538                 }
 539                 case 'D' :
 540                         r = strupper_talloc(tmp_ctx, domain_name);
 541                         if (r == NULL) {
 542                                 goto error;
 543                         }
 544                         a_string = realloc_string_sub(a_string, "%D", r);
 545                         break;
 546                 case 'I' : {
 547                         a_string = realloc_string_sub(
 548                                 a_string, "%I",
 549                                 sub_peeraddr[0] ? sub_peeraddr : "0.0.0.0");
 550                         break;
 551                 }
 552                 case 'i':
 553                         a_string = realloc_string_sub(
 554                                 a_string, "%i",
 555                                 sub_sockaddr[0] ? sub_sockaddr : "0.0.0.0");
 556                         break;
 557                 case 'L' :
 558                         if ( strncasecmp_m(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
 559                                 break;
 560                         }
 561                         if (local_machine_name && *local_machine_name) {
 562                                 a_string = realloc_string_sub(a_string, "%L", local_machine_name);
 563                         } else {
 564                                 a_string = realloc_string_sub(a_string, "%L", lp_netbios_name());
 565                         }
 566                         break;
 567                 case 'N':
 568                         a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
 569                         break;
 570                 case 'M' :
 571                         a_string = realloc_string_sub(a_string, "%M",
 572                                                       sub_peername ? sub_peername : "");
 573                         break;
 574                 case 'R' :
 575                         a_string = realloc_string_sub(a_string, "%R", remote_proto);
 576                         break;
 577                 case 'T' :
 578                         a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
 579                         break;
 580                 case 'a' :
 581                         a_string = realloc_string_sub(a_string, "%a",
 582                                         get_remote_arch_str());
 583                         break;
 584                 case 'd' :
 585                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)getpid());
 586                         a_string = realloc_string_sub(a_string, "%d", pidstr);
 587                         break;
 588                 case 'h' :
 589                         a_string = realloc_string_sub(a_string, "%h", myhostname());
 590                         break;
 591                 case 'm' :
 592                         a_string = realloc_string_sub(a_string, "%m",
 593                                                       remote_machine
 594                                                       ? remote_machine
 595                                                       : "");
 596                         break;
 597                 case 'v' :
 598                         a_string = realloc_string_sub(a_string, "%v", samba_version_string());
 599                         break;
 600                 case 'w' :
 601                         a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
 602                         break;
 603                 case '$' :
 604                         a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
 605                         break;
 606                 case 'V' :
 607                         slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
 608                         a_string = realloc_string_sub(a_string, "%V", vnnstr);
 609                         break;
 610                 default:
 611                         break;
 612                 }
 613
 614                 p++;
 615                 TALLOC_FREE(r);
 616
 617                 if (a_string == NULL) {
 618                         goto done;
 619                 }
 620         }
 621
 622         goto done;
 623
 624 error:
 625         TALLOC_FREE(a_string);
 626
 627 done:
 628         TALLOC_FREE(tmp_ctx);
 629         return a_string;
 630 }
 631
 632 /****************************************************************************
 633  Do some specific substitutions in a string.
 634  This function will return an allocated string that have to be freed.
 635 ****************************************************************************/
 636
 637 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 638                         const char *input_string,
 639                         const char *username,
 640                         const char *grpname,
 641                         const char *domain,
 642                         uid_t uid,
 643                         gid_t gid)
 644 {
 645         char *a_string;
 646         char *ret_string = NULL;
 647         char *b, *p, *s;
 648         TALLOC_CTX *tmp_ctx;
 649
 650         if (!(tmp_ctx = talloc_new(mem_ctx))) {
 651                 DEBUG(0, ("talloc_new failed\n"));
 652                 return NULL;
 653         }
 654
 655         a_string = talloc_strdup(tmp_ctx, input_string);
 656         if (a_string == NULL) {
 657                 DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
 658                 goto done;
 659         }
 660
 661         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 662
 663                 b = a_string;
 664
 665                 switch (*(p+1)) {
 666                 case 'U' :
 667                         a_string = talloc_string_sub(
 668                                 tmp_ctx, a_string, "%U", username);
 669                         break;
 670                 case 'u' :
 671                         a_string = talloc_string_sub(
 672                                 tmp_ctx, a_string, "%u", username);
 673                         break;
 674                 case 'G' :
 675                         if (gid != -1) {
 676                                 const char *name;
 677
 678                                 if (grpname != NULL) {
 679                                         name = grpname;
 680                                 } else {
 681                                         name = gidtoname(gid);
 682                                 }
 683
 684                                 a_string = talloc_string_sub(tmp_ctx,
 685                                                              a_string,
 686                                                              "%G",
 687                                                              name);
 688                         } else {
 689                                 a_string = talloc_string_sub(
 690                                         tmp_ctx, a_string,
 691                                         "%G", "NO_GROUP");
 692                         }
 693                         break;
 694                 case 'g' :
 695                         if (gid != -1) {
 696                                 const char *name;
 697
 698                                 if (grpname != NULL) {
 699                                         name = grpname;
 700                                 } else {
 701                                         name = gidtoname(gid);
 702                                 }
 703
 704                                 a_string = talloc_string_sub(tmp_ctx,
 705                                                              a_string,
 706                                                              "%g",
 707                                                              name);
 708                         } else {
 709                                 a_string = talloc_string_sub(
 710                                         tmp_ctx, a_string, "%g", "NO_GROUP");
 711                         }
 712                         break;
 713                 case 'D' :
 714                         a_string = talloc_string_sub(tmp_ctx, a_string,
 715                                                      "%D", domain);
 716                         break;
 717                 case 'N' :
 718                         a_string = talloc_string_sub(
 719                                 tmp_ctx, a_string, "%N",
 720                                 automount_server(username));
 721                         break;
 722                 default:
 723                         break;
 724                 }
 725
 726                 p++;
 727                 if (a_string == NULL) {
 728                         goto done;
 729                 }
 730         }
 731
 732         /* Watch out, using "mem_ctx" here, so all intermediate stuff goes
 733          * away with the TALLOC_FREE(tmp_ctx) further down. */
 734
 735         ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
 736
 737  done:
 738         TALLOC_FREE(tmp_ctx);
 739         return ret_string;
 740 }
 741
 742 /****************************************************************************
 743 ****************************************************************************/
 744
 745 char *talloc_sub_advanced(TALLOC_CTX *ctx,
 746                         const char *servicename,
 747                         const char *user,
 748                         const char *connectpath,
 749                         gid_t gid,
 750                         const char *smb_name,
 751                         const char *domain_name,
 752                         const char *str)
 753 {
 754         char *a_string, *ret_string;
 755         char *b, *p, *s;
 756
 757         a_string = talloc_strdup(talloc_tos(), str);
 758         if (a_string == NULL) {
 759                 DEBUG(0, ("talloc_sub_advanced: Out of memory!\n"));
 760                 return NULL;
 761         }
 762
 763         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 764
 765                 b = a_string;
 766
 767                 switch (*(p+1)) {
 768                 case 'N' :
 769                         a_string = realloc_string_sub(a_string, "%N", automount_server(user));
 770                         break;
 771                 case 'H': {
 772                         char *h;
 773                         if ((h = get_user_home_dir(talloc_tos(), user)))
 774                                 a_string = realloc_string_sub(a_string, "%H", h);
 775                         TALLOC_FREE(h);
 776                         break;
 777                 }
 778                 case 'P':
 779                         a_string = realloc_string_sub(a_string, "%P", connectpath);
 780                         break;
 781                 case 'S':
 782                         a_string = realloc_string_sub(a_string, "%S", servicename);
 783                         break;
 784                 case 'g':
 785                         a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
 786                         break;
 787                 case 'u':
 788                         a_string = realloc_string_sub(a_string, "%u", user);
 789                         break;
 790
 791                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 792                          * server name) in standard_sub_basic as it is
 793                          * a feature for logon servers, hence uses the
 794                          * username.  The %p (NIS server path) code is
 795                          * here as it is used instead of the default
 796                          * "path =" string in [homes] and so needs the
 797                          * service name, not the username.  */
 798                 case 'p':
 799                         a_string = realloc_string_sub(a_string, "%p",
 800                                                       automount_path(servicename));
 801                         break;
 802
 803                 default:
 804                         break;
 805                 }
 806
 807                 p++;
 808                 if (a_string == NULL) {
 809                         return NULL;
 810                 }
 811         }
 812
 813         ret_string = talloc_sub_basic(ctx, smb_name, domain_name, a_string);
 814         TALLOC_FREE(a_string);
 815         return ret_string;
 816 }
 817
 818 void standard_sub_advanced(const char *servicename, const char *user,
 819                            const char *connectpath, gid_t gid,
 820                            const char *smb_name, const char *domain_name,
 821                            char *str, size_t len)
 822 {
 823         char *s = talloc_sub_advanced(talloc_tos(),
 824                                 servicename, user, connectpath,
 825                                 gid, smb_name, domain_name, str);
 826
 827         if (!s) {
 828                 return;
 829         }
 830         strlcpy( str, s, len );
 831         TALLOC_FREE( s );
 832 }
 833
 834 /******************************************************************************
 835  version of standard_sub_basic() for string lists; uses talloc_sub_basic()
 836  for the work
 837  *****************************************************************************/
 838
 839 bool str_list_sub_basic( char **list, const char *smb_name,
 840                          const char *domain_name )
 841 {
 842         TALLOC_CTX *ctx = list;
 843         char *s, *tmpstr;
 844
 845         while ( *list ) {
 846                 s = *list;
 847                 tmpstr = talloc_sub_basic(ctx, smb_name, domain_name, s);
 848                 if ( !tmpstr ) {
 849                         DEBUG(0,("str_list_sub_basic: "
 850                                 "talloc_sub_basic() return NULL!\n"));
 851                         return false;
 852                 }
 853
 854                 TALLOC_FREE(*list);
 855                 *list = tmpstr;
 856
 857                 list++;
 858         }
 859
 860         return true;
 861 }