source/lib/substitute.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    string substitution functions
   4    Copyright (C) Andrew Tridgell 1992-2000
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21
  22 #include "includes.h"
  23
  24 fstring local_machine="";
  25 fstring remote_arch="UNKNOWN";
  26 userdom_struct current_user_info;
  27 fstring remote_proto="UNKNOWN";
  28
  29 static fstring remote_machine;
  30 static fstring smb_user_name;
  31
  32 /**
  33  * Set the 'local' machine name
  34  * @param local_name the name we are being called
  35  * @param if this is the 'final' name for us, not be be changed again
  36  */
  37
  38 void set_local_machine_name(const char* local_name, BOOL perm)
  39 {
  40         static BOOL already_perm = False;
  41         fstring tmp_local_machine;
  42
  43         fstrcpy(tmp_local_machine,local_name);
  44         trim_char(tmp_local_machine,' ',' ');
  45
  46         /*
  47          * Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
  48          * arrggg!!!
  49          */
  50
  51         if ( strequal(tmp_local_machine, "*SMBSERVER") || strequal(tmp_local_machine, "*SMBSERV") )  {
  52                 fstrcpy( local_machine, client_socket_addr() );
  53                 return;
  54         }
  55
  56         if (already_perm)
  57                 return;
  58
  59         already_perm = perm;
  60
  61         alpha_strcpy(local_machine,tmp_local_machine,SAFE_NETBIOS_CHARS,sizeof(local_machine)-1);
  62         strlower_m(local_machine);
  63 }
  64
  65 /**
  66  * Set the 'remote' machine name
  67  * @param remote_name the name our client wants to be called by
  68  * @param if this is the 'final' name for them, not be be changed again
  69  */
  70
  71 void set_remote_machine_name(const char* remote_name, BOOL perm)
  72 {
  73         static BOOL already_perm = False;
  74         fstring tmp_remote_machine;
  75
  76         if (already_perm)
  77                 return;
  78
  79         already_perm = perm;
  80
  81         fstrcpy(tmp_remote_machine,remote_name);
  82         trim_char(tmp_remote_machine,' ',' ');
  83         alpha_strcpy(remote_machine,tmp_remote_machine,SAFE_NETBIOS_CHARS,sizeof(remote_machine)-1);
  84         strlower_m(remote_machine);
  85 }
  86
  87 const char* get_remote_machine_name(void)
  88 {
  89         return remote_machine;
  90 }
  91
  92 const char* get_local_machine_name(void)
  93 {
  94         if (!*local_machine) {
  95                 return global_myname();
  96         }
  97
  98         return local_machine;
  99 }
 100
 101 /*******************************************************************
 102  Setup the string used by %U substitution.
 103 ********************************************************************/
 104
 105 void sub_set_smb_name(const char *name)
 106 {
 107         fstring tmp;
 108
 109         /* don't let anonymous logins override the name */
 110         if (! *name)
 111                 return;
 112
 113         fstrcpy(tmp,name);
 114         trim_char(tmp,' ',' ');
 115         strlower_m(tmp);
 116         alpha_strcpy(smb_user_name,tmp,SAFE_NETBIOS_CHARS,sizeof(smb_user_name)-1);
 117 }
 118
 119 char* sub_get_smb_name( void )
 120 {
 121         return smb_user_name;
 122 }
 123
 124 /*******************************************************************
 125  Setup the strings used by substitutions. Called per packet. Ensure
 126  %U name is set correctly also.
 127 ********************************************************************/
 128
 129 void set_current_user_info(const userdom_struct *pcui)
 130 {
 131         current_user_info = *pcui;
 132         /* The following is safe as current_user_info.smb_name
 133          * has already been sanitised in register_vuid. */
 134         fstrcpy(smb_user_name, current_user_info.smb_name);
 135 }
 136
 137 /*******************************************************************
 138  return the current active user name
 139 *******************************************************************/
 140
 141 const char* get_current_username( void )
 142 {
 143         if ( current_user_info.smb_name[0] == '\0' )
 144                 return smb_user_name;
 145
 146         return current_user_info.smb_name;
 147 }
 148
 149 /*******************************************************************
 150  Given a pointer to a %$(NAME) expand it as an environment variable.
 151  Return the number of characters by which the pointer should be advanced.
 152  Based on code by Branko Cibej <branko.cibej@hermes.si>
 153  When this is called p points at the '%' character.
 154 ********************************************************************/
 155
 156 static size_t expand_env_var(char *p, int len)
 157 {
 158         fstring envname;
 159         char *envval;
 160         char *q, *r;
 161         int copylen;
 162
 163         if (p[1] != '$')
 164                 return 1;
 165
 166         if (p[2] != '(')
 167                 return 2;
 168
 169         /*
 170          * Look for the terminating ')'.
 171          */
 172
 173         if ((q = strchr_m(p,')')) == NULL) {
 174                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 175                 return 2;
 176         }
 177
 178         /*
 179          * Extract the name from within the %$(NAME) string.
 180          */
 181
 182         r = p+3;
 183         copylen = MIN((q-r),(sizeof(envname)-1));
 184         strncpy(envname,r,copylen);
 185         envname[copylen] = '\0';
 186
 187         if ((envval = getenv(envname)) == NULL) {
 188                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 189                 return 2;
 190         }
 191
 192         /*
 193          * Copy the full %$(NAME) into envname so it
 194          * can be replaced.
 195          */
 196
 197         copylen = MIN((q+1-p),(sizeof(envname)-1));
 198         strncpy(envname,p,copylen);
 199         envname[copylen] = '\0';
 200         string_sub(p,envname,envval,len);
 201         return 0; /* Allow the environment contents to be parsed. */
 202 }
 203
 204 /*******************************************************************
 205  Given a pointer to a %$(NAME) in p and the whole string in str
 206  expand it as an environment variable.
 207  Return a new allocated and expanded string.
 208  Based on code by Branko Cibej <branko.cibej@hermes.si>
 209  When this is called p points at the '%' character.
 210  May substitute multiple occurrencies of the same env var.
 211 ********************************************************************/
 212
 213
 214 static char * realloc_expand_env_var(char *str, char *p)
 215 {
 216         char *envname;
 217         char *envval;
 218         char *q, *r;
 219         int copylen;
 220
 221         if (p[0] != '%' || p[1] != '$' || p[2] != '(')
 222                 return str;
 223
 224         /*
 225          * Look for the terminating ')'.
 226          */
 227
 228         if ((q = strchr_m(p,')')) == NULL) {
 229                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 230                 return str;
 231         }
 232
 233         /*
 234          * Extract the name from within the %$(NAME) string.
 235          */
 236
 237         r = p + 3;
 238         copylen = q - r;
 239         envname = (char *)SMB_MALLOC(copylen + 1 + 4); /* reserve space for use later add %$() chars */
 240         if (envname == NULL) return NULL;
 241         strncpy(envname,r,copylen);
 242         envname[copylen] = '\0';
 243
 244         if ((envval = getenv(envname)) == NULL) {
 245                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 246                 SAFE_FREE(envname);
 247                 return str;
 248         }
 249
 250         /*
 251          * Copy the full %$(NAME) into envname so it
 252          * can be replaced.
 253          */
 254
 255         copylen = q + 1 - p;
 256         strncpy(envname,p,copylen);
 257         envname[copylen] = '\0';
 258         r = realloc_string_sub(str, envname, envval);
 259         SAFE_FREE(envname);
 260         if (r == NULL) return NULL;
 261         return r;
 262 }
 263
 264 /*******************************************************************
 265  Patch from jkf@soton.ac.uk
 266  Added this to implement %p (NIS auto-map version of %H)
 267 *******************************************************************/
 268
 269 static char *automount_path(const char *user_name)
 270 {
 271         static pstring server_path;
 272
 273         /* use the passwd entry as the default */
 274         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 275
 276         pstrcpy(server_path, get_user_home_dir(user_name));
 277
 278 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 279
 280         if (lp_nis_home_map()) {
 281                 char *home_path_start;
 282                 char *automount_value = automount_lookup(user_name);
 283
 284                 if(strlen(automount_value) > 0) {
 285                         home_path_start = strchr_m(automount_value,':');
 286                         if (home_path_start != NULL) {
 287                                 DEBUG(5, ("NIS lookup succeeded.  Home path is: %s\n",
 288                                                 home_path_start?(home_path_start+1):""));
 289                                 pstrcpy(server_path, home_path_start+1);
 290                         }
 291                 } else {
 292                         /* NIS key lookup failed: default to user home directory from password file */
 293                         DEBUG(5, ("NIS lookup failed. Using Home path from passwd file. Home path is: %s\n", server_path ));
 294                 }
 295         }
 296 #endif
 297
 298         DEBUG(4,("Home server path: %s\n", server_path));
 299
 300         return server_path;
 301 }
 302
 303 /*******************************************************************
 304  Patch from jkf@soton.ac.uk
 305  This is Luke's original function with the NIS lookup code
 306  moved out to a separate function.
 307 *******************************************************************/
 308
 309 static const char *automount_server(const char *user_name)
 310 {
 311         static pstring server_name;
 312         const char *local_machine_name = get_local_machine_name();
 313
 314         /* use the local machine name as the default */
 315         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 316         if (local_machine_name && *local_machine_name)
 317                 pstrcpy(server_name, local_machine_name);
 318         else
 319                 pstrcpy(server_name, global_myname());
 320
 321 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 322
 323         if (lp_nis_home_map()) {
 324                 int home_server_len;
 325                 char *automount_value = automount_lookup(user_name);
 326                 home_server_len = strcspn(automount_value,":");
 327                 DEBUG(5, ("NIS lookup succeeded.  Home server length: %d\n",home_server_len));
 328                 if (home_server_len > sizeof(pstring))
 329                         home_server_len = sizeof(pstring);
 330                 strncpy(server_name, automount_value, home_server_len);
 331                 server_name[home_server_len] = '\0';
 332         }
 333 #endif
 334
 335         DEBUG(4,("Home server: %s\n", server_name));
 336
 337         return server_name;
 338 }
 339
 340 /****************************************************************************
 341  Do some standard substitutions in a string.
 342  len is the length in bytes of the space allowed in string str. If zero means
 343  don't allow expansions.
 344 ****************************************************************************/
 345
 346 void standard_sub_basic(const char *smb_name, char *str,size_t len)
 347 {
 348         char *p, *s;
 349         fstring pidstr;
 350         struct passwd *pass;
 351         const char *local_machine_name = get_local_machine_name();
 352
 353         for (s=str; (p=strchr_m(s, '%'));s=p) {
 354                 fstring tmp_str;
 355
 356                 int l = (int)len - (int)(p-str);
 357
 358                 if (l < 0)
 359                         l = 0;
 360
 361                 switch (*(p+1)) {
 362                 case 'U' :
 363                         fstrcpy(tmp_str, smb_name);
 364                         strlower_m(tmp_str);
 365                         string_sub(p,"%U",tmp_str,l);
 366                         break;
 367                 case 'G' :
 368                         fstrcpy(tmp_str, smb_name);
 369                         if ((pass = Get_Pwnam(tmp_str))!=NULL) {
 370                                 string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 371                         } else {
 372                                 p += 2;
 373                         }
 374                         break;
 375                 case 'D' :
 376                         fstrcpy(tmp_str, current_user_info.domain);
 377                         strupper_m(tmp_str);
 378                         string_sub(p,"%D", tmp_str,l);
 379                         break;
 380                 case 'I' :
 381                         string_sub(p,"%I", client_addr(),l);
 382                         break;
 383                 case 'i' :
 384                         string_sub(p,"%i", client_socket_addr(),l);
 385                         break;
 386                 case 'L' :
 387                         if (local_machine_name && *local_machine_name)
 388                                 string_sub(p,"%L", local_machine_name,l);
 389                         else {
 390                                 pstring temp_name;
 391
 392                                 pstrcpy(temp_name, global_myname());
 393                                 strlower_m(temp_name);
 394                                 string_sub(p,"%L", temp_name,l);
 395                         }
 396                         break;
 397                 case 'M' :
 398                         string_sub(p,"%M", client_name(),l);
 399                         break;
 400                 case 'R' :
 401                         string_sub(p,"%R", remote_proto,l);
 402                         break;
 403                 case 'T' :
 404                         string_sub(p,"%T", timestring(False),l);
 405                         break;
 406                 case 'a' :
 407                         string_sub(p,"%a", remote_arch,l);
 408                         break;
 409                 case 'd' :
 410                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 411                         string_sub(p,"%d", pidstr,l);
 412                         break;
 413                 case 'h' :
 414                         string_sub(p,"%h", myhostname(),l);
 415                         break;
 416                 case 'm' :
 417                         string_sub(p,"%m", get_remote_machine_name(),l);
 418                         break;
 419                 case 'v' :
 420                         string_sub(p,"%v", SAMBA_VERSION_STRING,l);
 421                         break;
 422                 case '$' :
 423                         p += expand_env_var(p,l);
 424                         break; /* Expand environment variables */
 425                 case '\0':
 426                         p++;
 427                         break; /* don't run off the end of the string */
 428
 429                 default: p+=2;
 430                         break;
 431                 }
 432         }
 433 }
 434
 435 static void standard_sub_advanced(int snum, const char *user,
 436                                   const char *connectpath, gid_t gid,
 437                                   const char *smb_name, char *str, size_t len)
 438 {
 439         char *p, *s, *home;
 440
 441         for (s=str; (p=strchr_m(s, '%'));s=p) {
 442                 int l = (int)len - (int)(p-str);
 443
 444                 if (l < 0)
 445                         l = 0;
 446
 447                 switch (*(p+1)) {
 448                 case 'N' :
 449                         string_sub(p,"%N", automount_server(user),l);
 450                         break;
 451                 case 'H':
 452                         if ((home = get_user_home_dir(user)))
 453                                 string_sub(p,"%H",home, l);
 454                         else
 455                                 p += 2;
 456                         break;
 457                 case 'P':
 458                         string_sub(p,"%P", connectpath, l);
 459                         break;
 460                 case 'S':
 461                         if ( snum != -1 )
 462                                 string_sub(p,"%S", lp_servicename(snum), l);
 463                         break;
 464                 case 'g':
 465                         string_sub(p,"%g", gidtoname(gid), l);
 466                         break;
 467                 case 'u':
 468                         string_sub(p,"%u", user, l);
 469                         break;
 470
 471                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 472                          * server name) in standard_sub_basic as it is
 473                          * a feature for logon servers, hence uses the
 474                          * username.  The %p (NIS server path) code is
 475                          * here as it is used instead of the default
 476                          * "path =" string in [homes] and so needs the
 477                          * service name, not the username.  */
 478                 case 'p':
 479                         if ( snum != -1 )
 480                                 string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 481                         break;
 482                 case '\0':
 483                         p++;
 484                         break; /* don't run off the end of the string */
 485
 486                 default: p+=2;
 487                         break;
 488                 }
 489         }
 490
 491         standard_sub_basic(smb_name, str, len);
 492 }
 493
 494 /****************************************************************************
 495  Do some standard substitutions in a string.
 496  This function will return an allocated string that have to be freed.
 497 ****************************************************************************/
 498
 499 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *str)
 500 {
 501         char *a, *t;
 502         a = alloc_sub_basic(smb_name, str);
 503         if (!a) return NULL;
 504         t = talloc_strdup(mem_ctx, a);
 505         SAFE_FREE(a);
 506         return t;
 507 }
 508
 509 char *alloc_sub_basic(const char *smb_name, const char *str)
 510 {
 511         char *b, *p, *s, *t, *r, *a_string;
 512         fstring pidstr;
 513         struct passwd *pass;
 514         const char *local_machine_name = get_local_machine_name();
 515
 516         /* workaround to prevent a crash while lookinf at bug #687 */
 517
 518         if ( !str ) {
 519                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 520                 return NULL;
 521         }
 522
 523         a_string = SMB_STRDUP(str);
 524         if (a_string == NULL) {
 525                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 526                 return NULL;
 527         }
 528
 529         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 530
 531                 r = NULL;
 532                 b = t = a_string;
 533
 534                 switch (*(p+1)) {
 535                 case 'U' :
 536                         r = strdup_lower(smb_name);
 537                         if (r == NULL) goto error;
 538                         t = realloc_string_sub(t, "%U", r);
 539                         break;
 540                 case 'G' :
 541                         r = SMB_STRDUP(smb_name);
 542                         if (r == NULL) goto error;
 543                         if ((pass = Get_Pwnam(r))!=NULL) {
 544                                 t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
 545                         }
 546                         break;
 547                 case 'D' :
 548                         r = strdup_upper(current_user_info.domain);
 549                         if (r == NULL) goto error;
 550                         t = realloc_string_sub(t, "%D", r);
 551                         break;
 552                 case 'I' :
 553                         t = realloc_string_sub(t, "%I", client_addr());
 554                         break;
 555                 case 'L' :
 556                         if (local_machine_name && *local_machine_name)
 557                                 t = realloc_string_sub(t, "%L", local_machine_name);
 558                         else
 559                                 t = realloc_string_sub(t, "%L", global_myname());
 560                         break;
 561                 case 'N':
 562                         t = realloc_string_sub(t, "%N", automount_server(smb_name));
 563                         break;
 564                 case 'M' :
 565                         t = realloc_string_sub(t, "%M", client_name());
 566                         break;
 567                 case 'R' :
 568                         t = realloc_string_sub(t, "%R", remote_proto);
 569                         break;
 570                 case 'T' :
 571                         t = realloc_string_sub(t, "%T", timestring(False));
 572                         break;
 573                 case 'a' :
 574                         t = realloc_string_sub(t, "%a", remote_arch);
 575                         break;
 576                 case 'd' :
 577                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 578                         t = realloc_string_sub(t, "%d", pidstr);
 579                         break;
 580                 case 'h' :
 581                         t = realloc_string_sub(t, "%h", myhostname());
 582                         break;
 583                 case 'm' :
 584                         t = realloc_string_sub(t, "%m", remote_machine);
 585                         break;
 586                 case 'v' :
 587                         t = realloc_string_sub(t, "%v", SAMBA_VERSION_STRING);
 588                         break;
 589                 case '$' :
 590                         t = realloc_expand_env_var(t, p); /* Expand environment variables */
 591                         break;
 592
 593                 default:
 594                         break;
 595                 }
 596
 597                 p++;
 598                 SAFE_FREE(r);
 599                 if (t == NULL) goto error;
 600                 a_string = t;
 601         }
 602
 603         return a_string;
 604 error:
 605         SAFE_FREE(a_string);
 606         return NULL;
 607 }
 608
 609 /****************************************************************************
 610  Do some specific substitutions in a string.
 611  This function will return an allocated string that have to be freed.
 612 ****************************************************************************/
 613
 614 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 615                         const char *input_string,
 616                         const char *username,
 617                         const char *domain,
 618                         uid_t uid,
 619                         gid_t gid)
 620 {
 621         char *a, *t;
 622         a = alloc_sub_specified(input_string, username, domain, uid, gid);
 623         if (!a) return NULL;
 624         t = talloc_strdup(mem_ctx, a);
 625         SAFE_FREE(a);
 626         return t;
 627 }
 628
 629 char *alloc_sub_specified(const char *input_string,
 630                         const char *username,
 631                         const char *domain,
 632                         uid_t uid,
 633                         gid_t gid)
 634 {
 635         char *a_string, *ret_string;
 636         char *b, *p, *s, *t;
 637
 638         a_string = SMB_STRDUP(input_string);
 639         if (a_string == NULL) {
 640                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 641                 return NULL;
 642         }
 643
 644         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 645
 646                 b = t = a_string;
 647
 648                 switch (*(p+1)) {
 649                 case 'U' :
 650                         t = realloc_string_sub(t, "%U", username);
 651                         break;
 652                 case 'u' :
 653                         t = realloc_string_sub(t, "%u", username);
 654                         break;
 655                 case 'G' :
 656                         if (gid != -1) {
 657                                 t = realloc_string_sub(t, "%G", gidtoname(gid));
 658                         } else {
 659                                 t = realloc_string_sub(t, "%G", "NO_GROUP");
 660                         }
 661                         break;
 662                 case 'g' :
 663                         if (gid != -1) {
 664                                 t = realloc_string_sub(t, "%g", gidtoname(gid));
 665                         } else {
 666                                 t = realloc_string_sub(t, "%g", "NO_GROUP");
 667                         }
 668                         break;
 669                 case 'D' :
 670                         t = realloc_string_sub(t, "%D", domain);
 671                         break;
 672                 case 'N' :
 673                         t = realloc_string_sub(t, "%N", automount_server(username));
 674                         break;
 675                 default:
 676                         break;
 677                 }
 678
 679                 p++;
 680                 if (t == NULL) {
 681                         SAFE_FREE(a_string);
 682                         return NULL;
 683                 }
 684                 a_string = t;
 685         }
 686
 687         ret_string = alloc_sub_basic(username, a_string);
 688         SAFE_FREE(a_string);
 689         return ret_string;
 690 }
 691
 692 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 693                         int snum,
 694                         const char *user,
 695                         const char *connectpath,
 696                         gid_t gid,
 697                         const char *smb_name,
 698                         const char *str)
 699 {
 700         char *a, *t;
 701         a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
 702         if (!a) return NULL;
 703         t = talloc_strdup(mem_ctx, a);
 704         SAFE_FREE(a);
 705         return t;
 706 }
 707
 708 char *alloc_sub_advanced(int snum, const char *user,
 709                                   const char *connectpath, gid_t gid,
 710                                   const char *smb_name, const char *str)
 711 {
 712         char *a_string, *ret_string;
 713         char *b, *p, *s, *t, *h;
 714
 715         a_string = SMB_STRDUP(str);
 716         if (a_string == NULL) {
 717                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 718                 return NULL;
 719         }
 720
 721         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 722
 723                 b = t = a_string;
 724
 725                 switch (*(p+1)) {
 726                 case 'N' :
 727                         t = realloc_string_sub(t, "%N", automount_server(user));
 728                         break;
 729                 case 'H':
 730                         if ((h = get_user_home_dir(user)))
 731                                 t = realloc_string_sub(t, "%H", h);
 732                         break;
 733                 case 'P':
 734                         t = realloc_string_sub(t, "%P", connectpath);
 735                         break;
 736                 case 'S':
 737                         t = realloc_string_sub(t, "%S", lp_servicename(snum));
 738                         break;
 739                 case 'g':
 740                         t = realloc_string_sub(t, "%g", gidtoname(gid));
 741                         break;
 742                 case 'u':
 743                         t = realloc_string_sub(t, "%u", user);
 744                         break;
 745
 746                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 747                          * server name) in standard_sub_basic as it is
 748                          * a feature for logon servers, hence uses the
 749                          * username.  The %p (NIS server path) code is
 750                          * here as it is used instead of the default
 751                          * "path =" string in [homes] and so needs the
 752                          * service name, not the username.  */
 753                 case 'p':
 754                         t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum)));
 755                         break;
 756
 757                 default:
 758                         break;
 759                 }
 760
 761                 p++;
 762                 if (t == NULL) {
 763                         SAFE_FREE(a_string);
 764                         return NULL;
 765                 }
 766                 a_string = t;
 767         }
 768
 769         ret_string = alloc_sub_basic(smb_name, a_string);
 770         SAFE_FREE(a_string);
 771         return ret_string;
 772 }
 773
 774 /****************************************************************************
 775  Do some standard substitutions in a string.
 776 ****************************************************************************/
 777
 778 void standard_sub_conn(connection_struct *conn, char *str, size_t len)
 779 {
 780         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 781                         conn->gid, smb_user_name, str, len);
 782 }
 783
 784 char *talloc_sub_conn(TALLOC_CTX *mem_ctx, connection_struct *conn, const char *str)
 785 {
 786         return talloc_sub_advanced(mem_ctx, SNUM(conn), conn->user,
 787                         conn->connectpath, conn->gid,
 788                         smb_user_name, str);
 789 }
 790
 791 char *alloc_sub_conn(connection_struct *conn, const char *str)
 792 {
 793         return alloc_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 794                         conn->gid, smb_user_name, str);
 795 }
 796
 797 /****************************************************************************
 798  Like standard_sub but by snum.
 799 ****************************************************************************/
 800
 801 void standard_sub_snum(int snum, char *str, size_t len)
 802 {
 803         extern struct current_user current_user;
 804         static uid_t cached_uid = -1;
 805         static fstring cached_user;
 806         /* calling uidtoname() on every substitute would be too expensive, so
 807            we cache the result here as nearly every call is for the same uid */
 808
 809         if (cached_uid != current_user.uid) {
 810                 fstrcpy(cached_user, uidtoname(current_user.uid));
 811                 cached_uid = current_user.uid;
 812         }
 813
 814         standard_sub_advanced(snum, cached_user, "", current_user.gid,
 815                               smb_user_name, str, len);
 816 }