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 static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
  28                              const char *str);
  29
  30 userdom_struct current_user_info;
  31 fstring remote_proto="UNKNOWN";
  32
  33 /**
  34  * Set the 'local' machine name
  35  * @param local_name the name we are being called
  36  * @param if this is the 'final' name for us, not be be changed again
  37  */
  38
  39 static char *local_machine;
  40
  41 void free_local_machine_name(void)
  42 {
  43         SAFE_FREE(local_machine);
  44 }
  45
  46 bool set_local_machine_name(const char *local_name, bool perm)
  47 {
  48         static bool already_perm = false;
  49         char *tmp_local_machine = NULL;
  50         size_t len;
  51
  52         if (already_perm) {
  53                 return true;
  54         }
  55
  56         tmp_local_machine = SMB_STRDUP(local_name);
  57         if (!tmp_local_machine) {
  58                 return false;
  59         }
  60         trim_char(tmp_local_machine,' ',' ');
  61
  62         SAFE_FREE(local_machine);
  63         len = strlen(tmp_local_machine);
  64         local_machine = SMB_CALLOC_ARRAY(char, len+1);
  65         if (!local_machine) {
  66                 SAFE_FREE(tmp_local_machine);
  67                 return false;
  68         }
  69         /* alpha_strcpy includes the space for the terminating nul. */
  70         alpha_strcpy(local_machine,tmp_local_machine,
  71                         SAFE_NETBIOS_CHARS,len+1);
  72         strlower_m(local_machine);
  73         SAFE_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 global_myname();
  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 = SMB_STRDUP(remote_name);
 108         if (!tmp_remote_machine) {
 109                 return false;
 110         }
 111         trim_char(tmp_remote_machine,' ',' ');
 112
 113         SAFE_FREE(remote_machine);
 114         len = strlen(tmp_remote_machine);
 115         remote_machine = SMB_CALLOC_ARRAY(char, len+1);
 116         if (!remote_machine) {
 117                 SAFE_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         strlower_m(remote_machine);
 125         SAFE_FREE(tmp_remote_machine);
 126
 127         already_perm = perm;
 128
 129         return true;
 130 }
 131
 132 const char *get_remote_machine_name(void)
 133 {
 134         return remote_machine ? remote_machine : "";
 135 }
 136
 137 /*******************************************************************
 138  Setup the string used by %U substitution.
 139 ********************************************************************/
 140
 141 static char *smb_user_name;
 142
 143 void sub_set_smb_name(const char *name)
 144 {
 145         char *tmp;
 146         size_t len;
 147         bool is_machine_account = false;
 148
 149         /* don't let anonymous logins override the name */
 150         if (!name || !*name) {
 151                 return;
 152         }
 153
 154         tmp = SMB_STRDUP(name);
 155         if (!tmp) {
 156                 return;
 157         }
 158         trim_char(tmp, ' ', ' ');
 159         strlower_m(tmp);
 160
 161         len = strlen(tmp);
 162
 163         if (len == 0) {
 164                 SAFE_FREE(tmp);
 165                 return;
 166         }
 167
 168         /* long story but here goes....we have to allow usernames
 169            ending in '$' as they are valid machine account names.
 170            So check for a machine account and re-add the '$'
 171            at the end after the call to alpha_strcpy().   --jerry  */
 172
 173         if (tmp[len-1] == '$') {
 174                 is_machine_account = True;
 175         }
 176
 177         SAFE_FREE(smb_user_name);
 178         smb_user_name = SMB_CALLOC_ARRAY(char, len+1);
 179         if (!smb_user_name) {
 180                 SAFE_FREE(tmp);
 181                 return;
 182         }
 183
 184         /* alpha_strcpy includes the space for the terminating nul. */
 185         alpha_strcpy(smb_user_name, tmp,
 186                         SAFE_NETBIOS_CHARS,
 187                         len+1);
 188
 189         SAFE_FREE(tmp);
 190
 191         if (is_machine_account) {
 192                 len = strlen(smb_user_name);
 193                 smb_user_name[len-1] = '$';
 194         }
 195 }
 196
 197 static char sub_peeraddr[INET6_ADDRSTRLEN];
 198 static const char *sub_peername = "";
 199 static char sub_sockaddr[INET6_ADDRSTRLEN];
 200
 201 void sub_set_socket_ids(const char *peeraddr, const char *peername,
 202                         const char *sockaddr)
 203 {
 204         const char *addr = peeraddr;
 205
 206         if (strnequal(addr, "::ffff:", 7)) {
 207                 addr += 7;
 208         }
 209         strlcpy(sub_peeraddr, addr, sizeof(sub_peeraddr));
 210
 211         sub_peername = SMB_STRDUP(peername);
 212         if (sub_peername == NULL) {
 213                 sub_peername = sub_peeraddr;
 214         }
 215
 216         /*
 217          * Shouldn't we do the ::ffff: cancellation here as well? The
 218          * original code in alloc_sub_basic() did not do it, so I'm
 219          * leaving it out here as well for compatibility.
 220          */
 221         strlcpy(sub_sockaddr, sockaddr, sizeof(sub_sockaddr));
 222 }
 223
 224 static const char *get_smb_user_name(void)
 225 {
 226         return smb_user_name ? smb_user_name : "";
 227 }
 228
 229 /*******************************************************************
 230  Setup the strings used by substitutions. Called per packet. Ensure
 231  %U name is set correctly also.
 232
 233  smb_name must be sanitized by alpha_strcpy
 234 ********************************************************************/
 235
 236 void set_current_user_info(const char *smb_name, const char *unix_name,
 237                            const char *domain)
 238 {
 239         fstrcpy(current_user_info.smb_name, smb_name);
 240         fstrcpy(current_user_info.unix_name, unix_name);
 241         fstrcpy(current_user_info.domain, domain);
 242
 243         /* The following is safe as current_user_info.smb_name
 244          * has already been sanitised in register_existing_vuid. */
 245
 246         sub_set_smb_name(current_user_info.smb_name);
 247 }
 248
 249 /*******************************************************************
 250  Return the current active user name.
 251 *******************************************************************/
 252
 253 const char *get_current_username(void)
 254 {
 255         if (current_user_info.smb_name[0] == '\0' ) {
 256                 return get_smb_user_name();
 257         }
 258
 259         return current_user_info.smb_name;
 260 }
 261
 262 /*******************************************************************
 263  Given a pointer to a %$(NAME) in p and the whole string in str
 264  expand it as an environment variable.
 265  Return a new allocated and expanded string.
 266  Based on code by Branko Cibej <branko.cibej@hermes.si>
 267  When this is called p points at the '%' character.
 268  May substitute multiple occurrencies of the same env var.
 269 ********************************************************************/
 270
 271 static char * realloc_expand_env_var(char *str, char *p)
 272 {
 273         char *envname;
 274         char *envval;
 275         char *q, *r;
 276         int copylen;
 277
 278         if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
 279                 return str;
 280         }
 281
 282         /*
 283          * Look for the terminating ')'.
 284          */
 285
 286         if ((q = strchr_m(p,')')) == NULL) {
 287                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 288                 return str;
 289         }
 290
 291         /*
 292          * Extract the name from within the %$(NAME) string.
 293          */
 294
 295         r = p + 3;
 296         copylen = q - r;
 297
 298         /* reserve space for use later add %$() chars */
 299         if ( (envname = (char *)SMB_MALLOC(copylen + 1 + 4)) == NULL ) {
 300                 return NULL;
 301         }
 302
 303         strncpy(envname,r,copylen);
 304         envname[copylen] = '\0';
 305
 306         if ((envval = getenv(envname)) == NULL) {
 307                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 308                 SAFE_FREE(envname);
 309                 return str;
 310         }
 311
 312         /*
 313          * Copy the full %$(NAME) into envname so it
 314          * can be replaced.
 315          */
 316
 317         copylen = q + 1 - p;
 318         strncpy(envname,p,copylen);
 319         envname[copylen] = '\0';
 320         r = realloc_string_sub(str, envname, envval);
 321         SAFE_FREE(envname);
 322
 323         return r;
 324 }
 325
 326 /*******************************************************************
 327 *******************************************************************/
 328
 329 static char *longvar_domainsid( void )
 330 {
 331         struct dom_sid sid;
 332         fstring tmp;
 333         char *sid_string;
 334
 335         if ( !secrets_fetch_domain_sid( lp_workgroup(), &sid ) ) {
 336                 return NULL;
 337         }
 338
 339         sid_string = SMB_STRDUP( sid_to_fstring( tmp, &sid ) );
 340
 341         if ( !sid_string ) {
 342                 DEBUG(0,("longvar_domainsid: failed to dup SID string!\n"));
 343         }
 344
 345         return sid_string;
 346 }
 347
 348 /*******************************************************************
 349 *******************************************************************/
 350
 351 struct api_longvar {
 352         const char *name;
 353         char* (*fn)( void );
 354 };
 355
 356 static struct api_longvar longvar_table[] = {
 357         { "DomainSID",          longvar_domainsid },
 358         { NULL,                 NULL }
 359 };
 360
 361 static char *get_longvar_val( const char *varname )
 362 {
 363         int i;
 364
 365         DEBUG(7,("get_longvar_val: expanding variable [%s]\n", varname));
 366
 367         for ( i=0; longvar_table[i].name; i++ ) {
 368                 if ( strequal( longvar_table[i].name, varname ) ) {
 369                         return longvar_table[i].fn();
 370                 }
 371         }
 372
 373         return NULL;
 374 }
 375
 376 /*******************************************************************
 377  Expand the long smb.conf variable names given a pointer to a %(NAME).
 378  Return the number of characters by which the pointer should be advanced.
 379  When this is called p points at the '%' character.
 380 ********************************************************************/
 381
 382 static char *realloc_expand_longvar(char *str, char *p)
 383 {
 384         fstring varname;
 385         char *value;
 386         char *q, *r;
 387         int copylen;
 388
 389         if ( p[0] != '%' || p[1] != '(' ) {
 390                 return str;
 391         }
 392
 393         /* Look for the terminating ')'.*/
 394
 395         if ((q = strchr_m(p,')')) == NULL) {
 396                 DEBUG(0,("realloc_expand_longvar: Unterminated environment variable [%s]\n", p));
 397                 return str;
 398         }
 399
 400         /* Extract the name from within the %(NAME) string.*/
 401
 402         r = p+2;
 403         copylen = MIN( (q-r), (sizeof(varname)-1) );
 404         strncpy(varname, r, copylen);
 405         varname[copylen] = '\0';
 406
 407         if ((value = get_longvar_val(varname)) == NULL) {
 408                 DEBUG(0,("realloc_expand_longvar: Variable [%s] not set.  Skipping\n", varname));
 409                 return str;
 410         }
 411
 412         /* Copy the full %(NAME) into envname so it can be replaced.*/
 413
 414         copylen = MIN( (q+1-p),(sizeof(varname)-1) );
 415         strncpy( varname, p, copylen );
 416         varname[copylen] = '\0';
 417         r = realloc_string_sub(str, varname, value);
 418         SAFE_FREE( value );
 419
 420         /* skip over the %(varname) */
 421
 422         return r;
 423 }
 424
 425 /*******************************************************************
 426  Patch from jkf@soton.ac.uk
 427  Added this to implement %p (NIS auto-map version of %H)
 428 *******************************************************************/
 429
 430 static const char *automount_path(const char *user_name)
 431 {
 432         TALLOC_CTX *ctx = talloc_tos();
 433         const char *server_path;
 434
 435         /* use the passwd entry as the default */
 436         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 437
 438         server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
 439         if (!server_path) {
 440                 return "";
 441         }
 442
 443 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 444
 445         if (lp_nis_home_map()) {
 446                 const char *home_path_start;
 447                 char *automount_value = automount_lookup(ctx, user_name);
 448
 449                 if(automount_value && strlen(automount_value) > 0) {
 450                         home_path_start = strchr_m(automount_value,':');
 451                         if (home_path_start != NULL) {
 452                                 DEBUG(5, ("NIS lookup succeeded. "
 453                                         "Home path is: %s\n",
 454                                         home_path_start ?
 455                                                 (home_path_start+1):""));
 456                                 server_path = talloc_strdup(ctx,
 457                                                         home_path_start+1);
 458                                 if (!server_path) {
 459                                         server_path = "";
 460                                 }
 461                         }
 462                 } else {
 463                         /* NIS key lookup failed: default to
 464                          * user home directory from password file */
 465                         DEBUG(5, ("NIS lookup failed. Using Home path from "
 466                         "passwd file. Home path is: %s\n", server_path ));
 467                 }
 468         }
 469 #endif
 470
 471         DEBUG(4,("Home server path: %s\n", server_path));
 472         return server_path;
 473 }
 474
 475 /*******************************************************************
 476  Patch from jkf@soton.ac.uk
 477  This is Luke's original function with the NIS lookup code
 478  moved out to a separate function.
 479 *******************************************************************/
 480
 481 static const char *automount_server(const char *user_name)
 482 {
 483         TALLOC_CTX *ctx = talloc_tos();
 484         const char *server_name;
 485         const char *local_machine_name = get_local_machine_name();
 486
 487         /* use the local machine name as the default */
 488         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 489         if (local_machine_name && *local_machine_name) {
 490                 server_name = talloc_strdup(ctx, local_machine_name);
 491         } else {
 492                 server_name = talloc_strdup(ctx, global_myname());
 493         }
 494
 495         if (!server_name) {
 496                 return "";
 497         }
 498
 499 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 500         if (lp_nis_home_map()) {
 501                 char *p;
 502                 char *srv;
 503                 char *automount_value = automount_lookup(ctx, user_name);
 504                 if (!automount_value) {
 505                         return "";
 506                 }
 507                 srv = talloc_strdup(ctx, automount_value);
 508                 if (!srv) {
 509                         return "";
 510                 }
 511                 p = strchr_m(srv, ':');
 512                 if (!p) {
 513                         return "";
 514                 }
 515                 *p = '\0';
 516                 server_name = srv;
 517                 DEBUG(5, ("NIS lookup succeeded.  Home server %s\n",
 518                                         server_name));
 519         }
 520 #endif
 521
 522         DEBUG(4,("Home server: %s\n", server_name));
 523         return server_name;
 524 }
 525
 526 /****************************************************************************
 527  Do some standard substitutions in a string.
 528  len is the length in bytes of the space allowed in string str. If zero means
 529  don't allow expansions.
 530 ****************************************************************************/
 531
 532 void standard_sub_basic(const char *smb_name, const char *domain_name,
 533                         char *str, size_t len)
 534 {
 535         char *s;
 536
 537         if ( (s = alloc_sub_basic( smb_name, domain_name, str )) != NULL ) {
 538                 strncpy( str, s, len );
 539         }
 540
 541         SAFE_FREE( s );
 542 }
 543
 544 /****************************************************************************
 545  Do some standard substitutions in a string.
 546  This function will return an allocated string that have to be freed.
 547 ****************************************************************************/
 548
 549 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name,
 550                        const char *domain_name, const char *str)
 551 {
 552         char *a, *t;
 553
 554         if ( (a = alloc_sub_basic(smb_name, domain_name, str)) == NULL ) {
 555                 return NULL;
 556         }
 557         t = talloc_strdup(mem_ctx, a);
 558         SAFE_FREE(a);
 559         return t;
 560 }
 561
 562 /****************************************************************************
 563 ****************************************************************************/
 564
 565 static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
 566                              const char *str)
 567 {
 568         char *b, *p, *s, *r, *a_string;
 569         fstring pidstr, vnnstr;
 570         const char *local_machine_name = get_local_machine_name();
 571         TALLOC_CTX *tmp_ctx = NULL;
 572
 573         /* workaround to prevent a crash while looking at bug #687 */
 574
 575         if (!str) {
 576                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 577                 return NULL;
 578         }
 579
 580         a_string = SMB_STRDUP(str);
 581         if (a_string == NULL) {
 582                 DEBUG(0, ("alloc_sub_basic: Out of memory!\n"));
 583                 return NULL;
 584         }
 585
 586         tmp_ctx = talloc_stackframe();
 587
 588         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 589
 590                 r = NULL;
 591                 b = a_string;
 592
 593                 switch (*(p+1)) {
 594                 case 'U' :
 595                         r = strlower_talloc(tmp_ctx, smb_name);
 596                         if (r == NULL) {
 597                                 goto error;
 598                         }
 599                         a_string = realloc_string_sub(a_string, "%U", r);
 600                         break;
 601                 case 'G' : {
 602                         struct passwd *pass;
 603                         r = talloc_strdup(tmp_ctx, smb_name);
 604                         if (r == NULL) {
 605                                 goto error;
 606                         }
 607                         pass = Get_Pwnam_alloc(tmp_ctx, r);
 608                         if (pass != NULL) {
 609                                 a_string = realloc_string_sub(
 610                                         a_string, "%G",
 611                                         gidtoname(pass->pw_gid));
 612                         }
 613                         TALLOC_FREE(pass);
 614                         break;
 615                 }
 616                 case 'D' :
 617                         r = strupper_talloc(tmp_ctx, domain_name);
 618                         if (r == NULL) {
 619                                 goto error;
 620                         }
 621                         a_string = realloc_string_sub(a_string, "%D", r);
 622                         break;
 623                 case 'I' : {
 624                         a_string = realloc_string_sub(
 625                                 a_string, "%I",
 626                                 sub_peeraddr[0] ? sub_peeraddr : "0.0.0.0");
 627                         break;
 628                 }
 629                 case 'i':
 630                         a_string = realloc_string_sub(
 631                                 a_string, "%i",
 632                                 sub_sockaddr[0] ? sub_sockaddr : "0.0.0.0");
 633                         break;
 634                 case 'L' :
 635                         if ( StrnCaseCmp(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
 636                                 break;
 637                         }
 638                         if (local_machine_name && *local_machine_name) {
 639                                 a_string = realloc_string_sub(a_string, "%L", local_machine_name);
 640                         } else {
 641                                 a_string = realloc_string_sub(a_string, "%L", global_myname());
 642                         }
 643                         break;
 644                 case 'N':
 645                         a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
 646                         break;
 647                 case 'M' :
 648                         a_string = realloc_string_sub(a_string, "%M",
 649                                                       sub_peername);
 650                         break;
 651                 case 'R' :
 652                         a_string = realloc_string_sub(a_string, "%R", remote_proto);
 653                         break;
 654                 case 'T' :
 655                         a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
 656                         break;
 657                 case 'a' :
 658                         a_string = realloc_string_sub(a_string, "%a",
 659                                         get_remote_arch_str());
 660                         break;
 661                 case 'd' :
 662                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 663                         a_string = realloc_string_sub(a_string, "%d", pidstr);
 664                         break;
 665                 case 'h' :
 666                         a_string = realloc_string_sub(a_string, "%h", myhostname());
 667                         break;
 668                 case 'm' :
 669                         a_string = realloc_string_sub(a_string, "%m",
 670                                                       remote_machine
 671                                                       ? remote_machine
 672                                                       : "");
 673                         break;
 674                 case 'v' :
 675                         a_string = realloc_string_sub(a_string, "%v", samba_version_string());
 676                         break;
 677                 case 'w' :
 678                         a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
 679                         break;
 680                 case '$' :
 681                         a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
 682                         break;
 683                 case '(':
 684                         a_string = realloc_expand_longvar( a_string, p );
 685                         break;
 686                 case 'V' :
 687                         slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
 688                         a_string = realloc_string_sub(a_string, "%V", vnnstr);
 689                         break;
 690                 default:
 691                         break;
 692                 }
 693
 694                 p++;
 695                 TALLOC_FREE(r);
 696
 697                 if (a_string == NULL) {
 698                         goto done;
 699                 }
 700         }
 701
 702         goto done;
 703
 704 error:
 705         SAFE_FREE(a_string);
 706
 707 done:
 708         TALLOC_FREE(tmp_ctx);
 709         return a_string;
 710 }
 711
 712 /****************************************************************************
 713  Do some specific substitutions in a string.
 714  This function will return an allocated string that have to be freed.
 715 ****************************************************************************/
 716
 717 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 718                         const char *input_string,
 719                         const char *username,
 720                         const char *domain,
 721                         uid_t uid,
 722                         gid_t gid)
 723 {
 724         char *a_string;
 725         char *ret_string = NULL;
 726         char *b, *p, *s;
 727         TALLOC_CTX *tmp_ctx;
 728
 729         if (!(tmp_ctx = talloc_new(mem_ctx))) {
 730                 DEBUG(0, ("talloc_new failed\n"));
 731                 return NULL;
 732         }
 733
 734         a_string = talloc_strdup(tmp_ctx, input_string);
 735         if (a_string == NULL) {
 736                 DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
 737                 goto done;
 738         }
 739
 740         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 741
 742                 b = a_string;
 743
 744                 switch (*(p+1)) {
 745                 case 'U' :
 746                         a_string = talloc_string_sub(
 747                                 tmp_ctx, a_string, "%U", username);
 748                         break;
 749                 case 'u' :
 750                         a_string = talloc_string_sub(
 751                                 tmp_ctx, a_string, "%u", username);
 752                         break;
 753                 case 'G' :
 754                         if (gid != -1) {
 755                                 a_string = talloc_string_sub(
 756                                         tmp_ctx, a_string, "%G",
 757                                         gidtoname(gid));
 758                         } else {
 759                                 a_string = talloc_string_sub(
 760                                         tmp_ctx, a_string,
 761                                         "%G", "NO_GROUP");
 762                         }
 763                         break;
 764                 case 'g' :
 765                         if (gid != -1) {
 766                                 a_string = talloc_string_sub(
 767                                         tmp_ctx, a_string, "%g",
 768                                         gidtoname(gid));
 769                         } else {
 770                                 a_string = talloc_string_sub(
 771                                         tmp_ctx, a_string, "%g", "NO_GROUP");
 772                         }
 773                         break;
 774                 case 'D' :
 775                         a_string = talloc_string_sub(tmp_ctx, a_string,
 776                                                      "%D", domain);
 777                         break;
 778                 case 'N' :
 779                         a_string = talloc_string_sub(
 780                                 tmp_ctx, a_string, "%N",
 781                                 automount_server(username));
 782                         break;
 783                 default:
 784                         break;
 785                 }
 786
 787                 p++;
 788                 if (a_string == NULL) {
 789                         goto done;
 790                 }
 791         }
 792
 793         /* Watch out, using "mem_ctx" here, so all intermediate stuff goes
 794          * away with the TALLOC_FREE(tmp_ctx) further down. */
 795
 796         ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
 797
 798  done:
 799         TALLOC_FREE(tmp_ctx);
 800         return ret_string;
 801 }
 802
 803 /****************************************************************************
 804 ****************************************************************************/
 805
 806 static char *alloc_sub_advanced(const char *servicename, const char *user,
 807                          const char *connectpath, gid_t gid,
 808                          const char *smb_name, const char *domain_name,
 809                          const char *str)
 810 {
 811         char *a_string, *ret_string;
 812         char *b, *p, *s;
 813
 814         a_string = SMB_STRDUP(str);
 815         if (a_string == NULL) {
 816                 DEBUG(0, ("alloc_sub_advanced: Out of memory!\n"));
 817                 return NULL;
 818         }
 819
 820         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 821
 822                 b = a_string;
 823
 824                 switch (*(p+1)) {
 825                 case 'N' :
 826                         a_string = realloc_string_sub(a_string, "%N", automount_server(user));
 827                         break;
 828                 case 'H': {
 829                         char *h;
 830                         if ((h = get_user_home_dir(talloc_tos(), user)))
 831                                 a_string = realloc_string_sub(a_string, "%H", h);
 832                         TALLOC_FREE(h);
 833                         break;
 834                 }
 835                 case 'P':
 836                         a_string = realloc_string_sub(a_string, "%P", connectpath);
 837                         break;
 838                 case 'S':
 839                         a_string = realloc_string_sub(a_string, "%S", servicename);
 840                         break;
 841                 case 'g':
 842                         a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
 843                         break;
 844                 case 'u':
 845                         a_string = realloc_string_sub(a_string, "%u", user);
 846                         break;
 847
 848                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 849                          * server name) in standard_sub_basic as it is
 850                          * a feature for logon servers, hence uses the
 851                          * username.  The %p (NIS server path) code is
 852                          * here as it is used instead of the default
 853                          * "path =" string in [homes] and so needs the
 854                          * service name, not the username.  */
 855                 case 'p':
 856                         a_string = realloc_string_sub(a_string, "%p",
 857                                                       automount_path(servicename));
 858                         break;
 859
 860                 default:
 861                         break;
 862                 }
 863
 864                 p++;
 865                 if (a_string == NULL) {
 866                         return NULL;
 867                 }
 868         }
 869
 870         ret_string = alloc_sub_basic(smb_name, domain_name, a_string);
 871         SAFE_FREE(a_string);
 872         return ret_string;
 873 }
 874
 875 /*
 876  * This obviously is inefficient and needs to be merged into
 877  * alloc_sub_advanced...
 878  */
 879
 880 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 881                           const char *servicename, const char *user,
 882                           const char *connectpath, gid_t gid,
 883                           const char *smb_name, const char *domain_name,
 884                           const char *str)
 885 {
 886         char *a, *t;
 887
 888         if (!(a = alloc_sub_advanced(servicename, user, connectpath, gid,
 889                                      smb_name, domain_name, str))) {
 890                 return NULL;
 891         }
 892         t = talloc_strdup(mem_ctx, a);
 893         SAFE_FREE(a);
 894         return t;
 895 }
 896
 897
 898 void standard_sub_advanced(const char *servicename, const char *user,
 899                            const char *connectpath, gid_t gid,
 900                            const char *smb_name, const char *domain_name,
 901                            char *str, size_t len)
 902 {
 903         char *s;
 904
 905         s = alloc_sub_advanced(servicename, user, connectpath,
 906                                gid, smb_name, domain_name, str);
 907
 908         if ( s ) {
 909                 strncpy( str, s, len );
 910                 SAFE_FREE( s );
 911         }
 912 }
 913
 914 /****************************************************************************
 915  Do some standard substitutions in a string.
 916 ****************************************************************************/
 917
 918 char *standard_sub_conn(TALLOC_CTX *ctx, connection_struct *conn, const char *str)
 919 {
 920         return talloc_sub_advanced(ctx,
 921                                 lp_servicename(SNUM(conn)),
 922                                 conn->session_info->unix_name,
 923                                 conn->connectpath,
 924                                 conn->session_info->utok.gid,
 925                                 get_smb_user_name(),
 926                                 "",
 927                                 str);
 928 }