source3/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         /*
  44          * Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
  45          * arrggg!!!
  46          */
  47
  48         if (strcasecmp(local_name, "*SMBSERVER")==0)
  49                 return;
  50
  51         if (strcasecmp(local_name, "*SMBSERV")==0)
  52                 return;
  53
  54         if (already_perm)
  55                 return;
  56
  57         already_perm = perm;
  58
  59         fstrcpy(tmp_local_machine,local_name);
  60         trim_char(tmp_local_machine,' ',' ');
  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 /*******************************************************************
 120  Setup the strings used by substitutions. Called per packet. Ensure
 121  %U name is set correctly also.
 122 ********************************************************************/
 123
 124 void set_current_user_info(const userdom_struct *pcui)
 125 {
 126         current_user_info = *pcui;
 127         /* The following is safe as current_user_info.smb_name
 128          * has already been sanitised in register_vuid. */
 129         fstrcpy(smb_user_name, current_user_info.smb_name);
 130 }
 131
 132 /*******************************************************************
 133  Given a pointer to a %$(NAME) expand it as an environment variable.
 134  Return the number of characters by which the pointer should be advanced.
 135  Based on code by Branko Cibej <branko.cibej@hermes.si>
 136  When this is called p points at the '%' character.
 137 ********************************************************************/
 138
 139 static size_t expand_env_var(char *p, int len)
 140 {
 141         fstring envname;
 142         char *envval;
 143         char *q, *r;
 144         int copylen;
 145
 146         if (p[1] != '$')
 147                 return 1;
 148
 149         if (p[2] != '(')
 150                 return 2;
 151
 152         /*
 153          * Look for the terminating ')'.
 154          */
 155
 156         if ((q = strchr_m(p,')')) == NULL) {
 157                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 158                 return 2;
 159         }
 160
 161         /*
 162          * Extract the name from within the %$(NAME) string.
 163          */
 164
 165         r = p+3;
 166         copylen = MIN((q-r),(sizeof(envname)-1));
 167         strncpy(envname,r,copylen);
 168         envname[copylen] = '\0';
 169
 170         if ((envval = getenv(envname)) == NULL) {
 171                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 172                 return 2;
 173         }
 174
 175         /*
 176          * Copy the full %$(NAME) into envname so it
 177          * can be replaced.
 178          */
 179
 180         copylen = MIN((q+1-p),(sizeof(envname)-1));
 181         strncpy(envname,p,copylen);
 182         envname[copylen] = '\0';
 183         string_sub(p,envname,envval,len);
 184         return 0; /* Allow the environment contents to be parsed. */
 185 }
 186
 187 /*******************************************************************
 188  Given a pointer to a %$(NAME) in p and the whole string in str
 189  expand it as an environment variable.
 190  Return a new allocated and expanded string.
 191  Based on code by Branko Cibej <branko.cibej@hermes.si>
 192  When this is called p points at the '%' character.
 193  May substitute multiple occurrencies of the same env var.
 194 ********************************************************************/
 195
 196
 197 static char * realloc_expand_env_var(char *str, char *p)
 198 {
 199         char *envname;
 200         char *envval;
 201         char *q, *r;
 202         int copylen;
 203
 204         if (p[0] != '%' || p[1] != '$' || p[2] != '(')
 205                 return str;
 206
 207         /*
 208          * Look for the terminating ')'.
 209          */
 210
 211         if ((q = strchr_m(p,')')) == NULL) {
 212                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 213                 return str;
 214         }
 215
 216         /*
 217          * Extract the name from within the %$(NAME) string.
 218          */
 219
 220         r = p + 3;
 221         copylen = q - r;
 222         envname = (char *)malloc(copylen + 1 + 4); /* reserve space for use later add %$() chars */
 223         if (envname == NULL) return NULL;
 224         strncpy(envname,r,copylen);
 225         envname[copylen] = '\0';
 226
 227         if ((envval = getenv(envname)) == NULL) {
 228                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 229                 SAFE_FREE(envname);
 230                 return str;
 231         }
 232
 233         /*
 234          * Copy the full %$(NAME) into envname so it
 235          * can be replaced.
 236          */
 237
 238         copylen = q + 1 - p;
 239         strncpy(envname,p,copylen);
 240         envname[copylen] = '\0';
 241         r = realloc_string_sub(str, envname, envval);
 242         SAFE_FREE(envname);
 243         if (r == NULL) return NULL;
 244         return r;
 245 }
 246
 247 /*******************************************************************
 248  Patch from jkf@soton.ac.uk
 249  Added this to implement %p (NIS auto-map version of %H)
 250 *******************************************************************/
 251
 252 static char *automount_path(const char *user_name)
 253 {
 254         static pstring server_path;
 255
 256         /* use the passwd entry as the default */
 257         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 258
 259         pstrcpy(server_path, get_user_home_dir(user_name));
 260
 261 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 262
 263         if (lp_nis_home_map()) {
 264                 char *home_path_start;
 265                 char *automount_value = automount_lookup(user_name);
 266
 267                 if(strlen(automount_value) > 0) {
 268                         home_path_start = strchr_m(automount_value,':');
 269                         if (home_path_start != NULL) {
 270                                 DEBUG(5, ("NIS lookup succeeded.  Home path is: %s\n",
 271                                                 home_path_start?(home_path_start+1):""));
 272                                 pstrcpy(server_path, home_path_start+1);
 273                         }
 274                 } else {
 275                         /* NIS key lookup failed: default to user home directory from password file */
 276                         DEBUG(5, ("NIS lookup failed. Using Home path from passwd file. Home path is: %s\n", server_path ));
 277                 }
 278         }
 279 #endif
 280
 281         DEBUG(4,("Home server path: %s\n", server_path));
 282
 283         return server_path;
 284 }
 285
 286 /*******************************************************************
 287  Patch from jkf@soton.ac.uk
 288  This is Luke's original function with the NIS lookup code
 289  moved out to a separate function.
 290 *******************************************************************/
 291
 292 static const char *automount_server(const char *user_name)
 293 {
 294         static pstring server_name;
 295         const char *local_machine_name = get_local_machine_name();
 296
 297         /* use the local machine name as the default */
 298         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 299         if (local_machine_name && *local_machine_name)
 300                 pstrcpy(server_name, local_machine_name);
 301         else
 302                 pstrcpy(server_name, global_myname());
 303
 304 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 305
 306         if (lp_nis_home_map()) {
 307                 int home_server_len;
 308                 char *automount_value = automount_lookup(user_name);
 309                 home_server_len = strcspn(automount_value,":");
 310                 DEBUG(5, ("NIS lookup succeeded.  Home server length: %d\n",home_server_len));
 311                 if (home_server_len > sizeof(pstring))
 312                         home_server_len = sizeof(pstring);
 313                 strncpy(server_name, automount_value, home_server_len);
 314                 server_name[home_server_len] = '\0';
 315         }
 316 #endif
 317
 318         DEBUG(4,("Home server: %s\n", server_name));
 319
 320         return server_name;
 321 }
 322
 323 /****************************************************************************
 324  Do some standard substitutions in a string.
 325  len is the length in bytes of the space allowed in string str. If zero means
 326  don't allow expansions.
 327 ****************************************************************************/
 328
 329 void standard_sub_basic(const char *smb_name, char *str,size_t len)
 330 {
 331         char *p, *s;
 332         fstring pidstr;
 333         struct passwd *pass;
 334         const char *local_machine_name = get_local_machine_name();
 335
 336         for (s=str; (p=strchr_m(s, '%'));s=p) {
 337                 fstring tmp_str;
 338
 339                 int l = (int)len - (int)(p-str);
 340
 341                 if (l < 0)
 342                         l = 0;
 343
 344                 switch (*(p+1)) {
 345                 case 'U' :
 346                         fstrcpy(tmp_str, smb_name);
 347                         strlower_m(tmp_str);
 348                         string_sub(p,"%U",tmp_str,l);
 349                         break;
 350                 case 'G' :
 351                         fstrcpy(tmp_str, smb_name);
 352                         if ((pass = Get_Pwnam(tmp_str))!=NULL) {
 353                                 string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 354                         } else {
 355                                 p += 2;
 356                         }
 357                         break;
 358                 case 'D' :
 359                         fstrcpy(tmp_str, current_user_info.domain);
 360                         strupper_m(tmp_str);
 361                         string_sub(p,"%D", tmp_str,l);
 362                         break;
 363                 case 'I' :
 364                         string_sub(p,"%I", client_addr(),l);
 365                         break;
 366                 case 'L' :
 367                         if (local_machine_name && *local_machine_name)
 368                                 string_sub(p,"%L", local_machine_name,l);
 369                         else {
 370                                 pstring temp_name;
 371
 372                                 pstrcpy(temp_name, global_myname());
 373                                 strlower_m(temp_name);
 374                                 string_sub(p,"%L", temp_name,l);
 375                         }
 376                         break;
 377                 case 'M' :
 378                         string_sub(p,"%M", client_name(),l);
 379                         break;
 380                 case 'R' :
 381                         string_sub(p,"%R", remote_proto,l);
 382                         break;
 383                 case 'T' :
 384                         string_sub(p,"%T", timestring(False),l);
 385                         break;
 386                 case 'a' :
 387                         string_sub(p,"%a", remote_arch,l);
 388                         break;
 389                 case 'd' :
 390                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 391                         string_sub(p,"%d", pidstr,l);
 392                         break;
 393                 case 'h' :
 394                         string_sub(p,"%h", myhostname(),l);
 395                         break;
 396                 case 'm' :
 397                         string_sub(p,"%m", get_remote_machine_name(),l);
 398                         break;
 399                 case 'v' :
 400                         string_sub(p,"%v", SAMBA_VERSION_STRING,l);
 401                         break;
 402                 case '$' :
 403                         p += expand_env_var(p,l);
 404                         break; /* Expand environment variables */
 405                 case '\0':
 406                         p++;
 407                         break; /* don't run off the end of the string */
 408
 409                 default: p+=2;
 410                         break;
 411                 }
 412         }
 413 }
 414
 415 static void standard_sub_advanced(int snum, const char *user,
 416                                   const char *connectpath, gid_t gid,
 417                                   const char *smb_name, char *str, size_t len)
 418 {
 419         char *p, *s, *home;
 420
 421         for (s=str; (p=strchr_m(s, '%'));s=p) {
 422                 int l = (int)len - (int)(p-str);
 423
 424                 if (l < 0)
 425                         l = 0;
 426
 427                 switch (*(p+1)) {
 428                 case 'N' :
 429                         string_sub(p,"%N", automount_server(user),l);
 430                         break;
 431                 case 'H':
 432                         if ((home = get_user_home_dir(user)))
 433                                 string_sub(p,"%H",home, l);
 434                         else
 435                                 p += 2;
 436                         break;
 437                 case 'P':
 438                         string_sub(p,"%P", connectpath, l);
 439                         break;
 440                 case 'S':
 441                         string_sub(p,"%S", lp_servicename(snum), l);
 442                         break;
 443                 case 'g':
 444                         string_sub(p,"%g", gidtoname(gid), l);
 445                         break;
 446                 case 'u':
 447                         string_sub(p,"%u", user, l);
 448                         break;
 449
 450                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 451                          * server name) in standard_sub_basic as it is
 452                          * a feature for logon servers, hence uses the
 453                          * username.  The %p (NIS server path) code is
 454                          * here as it is used instead of the default
 455                          * "path =" string in [homes] and so needs the
 456                          * service name, not the username.  */
 457                 case 'p':
 458                         string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 459                         break;
 460                 case '\0':
 461                         p++;
 462                         break; /* don't run off the end of the string */
 463
 464                 default: p+=2;
 465                         break;
 466                 }
 467         }
 468
 469         standard_sub_basic(smb_name, str, len);
 470 }
 471
 472 /****************************************************************************
 473  Do some standard substitutions in a string.
 474  This function will return an allocated string that have to be freed.
 475 ****************************************************************************/
 476
 477 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *str)
 478 {
 479         char *a, *t;
 480         a = alloc_sub_basic(smb_name, str);
 481         if (!a) return NULL;
 482         t = talloc_strdup(mem_ctx, a);
 483         SAFE_FREE(a);
 484         return t;
 485 }
 486
 487 char *alloc_sub_basic(const char *smb_name, const char *str)
 488 {
 489         char *b, *p, *s, *t, *r, *a_string;
 490         fstring pidstr;
 491         struct passwd *pass;
 492         const char *local_machine_name = get_local_machine_name();
 493
 494         a_string = strdup(str);
 495         if (a_string == NULL) {
 496                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 497                 return NULL;
 498         }
 499
 500         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 501
 502                 r = NULL;
 503                 b = t = a_string;
 504
 505                 switch (*(p+1)) {
 506                 case 'U' :
 507                         r = strdup_lower(smb_name);
 508                         if (r == NULL) goto error;
 509                         t = realloc_string_sub(t, "%U", r);
 510                         break;
 511                 case 'G' :
 512                         r = strdup(smb_name);
 513                         if (r == NULL) goto error;
 514                         if ((pass = Get_Pwnam(r))!=NULL) {
 515                                 t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
 516                         }
 517                         break;
 518                 case 'D' :
 519                         r = strdup_upper(current_user_info.domain);
 520                         if (r == NULL) goto error;
 521                         t = realloc_string_sub(t, "%D", r);
 522                         break;
 523                 case 'I' :
 524                         t = realloc_string_sub(t, "%I", client_addr());
 525                         break;
 526                 case 'L' :
 527                         if (local_machine_name && *local_machine_name)
 528                                 t = realloc_string_sub(t, "%L", local_machine_name);
 529                         else
 530                                 t = realloc_string_sub(t, "%L", global_myname());
 531                         break;
 532                 case 'M' :
 533                         t = realloc_string_sub(t, "%M", client_name());
 534                         break;
 535                 case 'R' :
 536                         t = realloc_string_sub(t, "%R", remote_proto);
 537                         break;
 538                 case 'T' :
 539                         t = realloc_string_sub(t, "%T", timestring(False));
 540                         break;
 541                 case 'a' :
 542                         t = realloc_string_sub(t, "%a", remote_arch);
 543                         break;
 544                 case 'd' :
 545                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 546                         t = realloc_string_sub(t, "%d", pidstr);
 547                         break;
 548                 case 'h' :
 549                         t = realloc_string_sub(t, "%h", myhostname());
 550                         break;
 551                 case 'm' :
 552                         t = realloc_string_sub(t, "%m", remote_machine);
 553                         break;
 554                 case 'v' :
 555                         t = realloc_string_sub(t, "%v", SAMBA_VERSION_STRING);
 556                         break;
 557                 case '$' :
 558                         t = realloc_expand_env_var(t, p); /* Expand environment variables */
 559                         break;
 560
 561                 default:
 562                         break;
 563                 }
 564
 565                 p++;
 566                 SAFE_FREE(r);
 567                 if (t == NULL) goto error;
 568                 a_string = t;
 569         }
 570
 571         return a_string;
 572 error:
 573         SAFE_FREE(a_string);
 574         return NULL;
 575 }
 576
 577 /****************************************************************************
 578  Do some specific substitutions in a string.
 579  This function will return an allocated string that have to be freed.
 580 ****************************************************************************/
 581
 582 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 583                         const char *input_string,
 584                         const char *username,
 585                         const char *domain,
 586                         uid_t uid,
 587                         gid_t gid)
 588 {
 589         char *a, *t;
 590         a = alloc_sub_specified(input_string, username, domain, uid, gid);
 591         if (!a) return NULL;
 592         t = talloc_strdup(mem_ctx, a);
 593         SAFE_FREE(a);
 594         return t;
 595 }
 596
 597 char *alloc_sub_specified(const char *input_string,
 598                         const char *username,
 599                         const char *domain,
 600                         uid_t uid,
 601                         gid_t gid)
 602 {
 603         char *a_string, *ret_string;
 604         char *b, *p, *s, *t;
 605
 606         a_string = strdup(input_string);
 607         if (a_string == NULL) {
 608                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 609                 return NULL;
 610         }
 611
 612         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 613
 614                 b = t = a_string;
 615
 616                 switch (*(p+1)) {
 617                 case 'U' :
 618                         t = realloc_string_sub(t, "%U", username);
 619                         break;
 620                 case 'u' :
 621                         t = realloc_string_sub(t, "%u", username);
 622                         break;
 623                 case 'G' :
 624                         if (gid != -1) {
 625                                 t = realloc_string_sub(t, "%G", gidtoname(gid));
 626                         } else {
 627                                 t = realloc_string_sub(t, "%G", "NO_GROUP");
 628                         }
 629                         break;
 630                 case 'g' :
 631                         if (gid != -1) {
 632                                 t = realloc_string_sub(t, "%g", gidtoname(gid));
 633                         } else {
 634                                 t = realloc_string_sub(t, "%g", "NO_GROUP");
 635                         }
 636                         break;
 637                 case 'D' :
 638                         t = realloc_string_sub(t, "%D", domain);
 639                         break;
 640                 case 'N' :
 641                         t = realloc_string_sub(t, "%N", automount_server(username));
 642                         break;
 643                 default:
 644                         break;
 645                 }
 646
 647                 p++;
 648                 if (t == NULL) {
 649                         SAFE_FREE(a_string);
 650                         return NULL;
 651                 }
 652                 a_string = t;
 653         }
 654
 655         ret_string = alloc_sub_basic(username, a_string);
 656         SAFE_FREE(a_string);
 657         return ret_string;
 658 }
 659
 660 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 661                         int snum,
 662                         const char *user,
 663                         const char *connectpath,
 664                         gid_t gid,
 665                         const char *smb_name,
 666                         const char *str)
 667 {
 668         char *a, *t;
 669         a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
 670         if (!a) return NULL;
 671         t = talloc_strdup(mem_ctx, a);
 672         SAFE_FREE(a);
 673         return t;
 674 }
 675
 676 char *alloc_sub_advanced(int snum, const char *user,
 677                                   const char *connectpath, gid_t gid,
 678                                   const char *smb_name, const char *str)
 679 {
 680         char *a_string, *ret_string;
 681         char *b, *p, *s, *t, *h;
 682
 683         a_string = strdup(str);
 684         if (a_string == NULL) {
 685                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 686                 return NULL;
 687         }
 688
 689         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 690
 691                 b = t = a_string;
 692
 693                 switch (*(p+1)) {
 694                 case 'N' :
 695                         t = realloc_string_sub(t, "%N", automount_server(user));
 696                         break;
 697                 case 'H':
 698                         if ((h = get_user_home_dir(user)))
 699                                 t = realloc_string_sub(t, "%H", h);
 700                         break;
 701                 case 'P':
 702                         t = realloc_string_sub(t, "%P", connectpath);
 703                         break;
 704                 case 'S':
 705                         t = realloc_string_sub(t, "%S", lp_servicename(snum));
 706                         break;
 707                 case 'g':
 708                         t = realloc_string_sub(t, "%g", gidtoname(gid));
 709                         break;
 710                 case 'u':
 711                         t = realloc_string_sub(t, "%u", user);
 712                         break;
 713
 714                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 715                          * server name) in standard_sub_basic as it is
 716                          * a feature for logon servers, hence uses the
 717                          * username.  The %p (NIS server path) code is
 718                          * here as it is used instead of the default
 719                          * "path =" string in [homes] and so needs the
 720                          * service name, not the username.  */
 721                 case 'p':
 722                         t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum)));
 723                         break;
 724
 725                 default:
 726                         break;
 727                 }
 728
 729                 p++;
 730                 if (t == NULL) {
 731                         SAFE_FREE(a_string);
 732                         return NULL;
 733                 }
 734                 a_string = t;
 735         }
 736
 737         ret_string = alloc_sub_basic(smb_name, a_string);
 738         SAFE_FREE(a_string);
 739         return ret_string;
 740 }
 741
 742 /****************************************************************************
 743  Do some standard substitutions in a string.
 744 ****************************************************************************/
 745
 746 void standard_sub_conn(connection_struct *conn, char *str, size_t len)
 747 {
 748         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 749                         conn->gid, smb_user_name, str, len);
 750 }
 751
 752 char *talloc_sub_conn(TALLOC_CTX *mem_ctx, connection_struct *conn, const char *str)
 753 {
 754         return talloc_sub_advanced(mem_ctx, SNUM(conn), conn->user,
 755                         conn->connectpath, conn->gid,
 756                         smb_user_name, str);
 757 }
 758
 759 char *alloc_sub_conn(connection_struct *conn, const char *str)
 760 {
 761         return alloc_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 762                         conn->gid, smb_user_name, str);
 763 }
 764
 765 /****************************************************************************
 766  Like standard_sub but by snum.
 767 ****************************************************************************/
 768
 769 void standard_sub_snum(int snum, char *str, size_t len)
 770 {
 771         extern struct current_user current_user;
 772         static uid_t cached_uid = -1;
 773         static fstring cached_user;
 774         /* calling uidtoname() on every substitute would be too expensive, so
 775            we cache the result here as nearly every call is for the same uid */
 776
 777         if (cached_uid != current_user.uid) {
 778                 fstrcpy(cached_user, uidtoname(current_user.uid));
 779                 cached_uid = current_user.uid;
 780         }
 781
 782         standard_sub_advanced(snum, cached_user, "", -1,
 783                               smb_user_name, str, len);
 784 }