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  Given a pointer to a %$(NAME) expand it as an environment variable.
 139  Return the number of characters by which the pointer should be advanced.
 140  Based on code by Branko Cibej <branko.cibej@hermes.si>
 141  When this is called p points at the '%' character.
 142 ********************************************************************/
 143
 144 static size_t expand_env_var(char *p, int len)
 145 {
 146         fstring envname;
 147         char *envval;
 148         char *q, *r;
 149         int copylen;
 150
 151         if (p[1] != '$')
 152                 return 1;
 153
 154         if (p[2] != '(')
 155                 return 2;
 156
 157         /*
 158          * Look for the terminating ')'.
 159          */
 160
 161         if ((q = strchr_m(p,')')) == NULL) {
 162                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 163                 return 2;
 164         }
 165
 166         /*
 167          * Extract the name from within the %$(NAME) string.
 168          */
 169
 170         r = p+3;
 171         copylen = MIN((q-r),(sizeof(envname)-1));
 172         strncpy(envname,r,copylen);
 173         envname[copylen] = '\0';
 174
 175         if ((envval = getenv(envname)) == NULL) {
 176                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 177                 return 2;
 178         }
 179
 180         /*
 181          * Copy the full %$(NAME) into envname so it
 182          * can be replaced.
 183          */
 184
 185         copylen = MIN((q+1-p),(sizeof(envname)-1));
 186         strncpy(envname,p,copylen);
 187         envname[copylen] = '\0';
 188         string_sub(p,envname,envval,len);
 189         return 0; /* Allow the environment contents to be parsed. */
 190 }
 191
 192 /*******************************************************************
 193  Given a pointer to a %$(NAME) in p and the whole string in str
 194  expand it as an environment variable.
 195  Return a new allocated and expanded string.
 196  Based on code by Branko Cibej <branko.cibej@hermes.si>
 197  When this is called p points at the '%' character.
 198  May substitute multiple occurrencies of the same env var.
 199 ********************************************************************/
 200
 201
 202 static char * realloc_expand_env_var(char *str, char *p)
 203 {
 204         char *envname;
 205         char *envval;
 206         char *q, *r;
 207         int copylen;
 208
 209         if (p[0] != '%' || p[1] != '$' || p[2] != '(')
 210                 return str;
 211
 212         /*
 213          * Look for the terminating ')'.
 214          */
 215
 216         if ((q = strchr_m(p,')')) == NULL) {
 217                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 218                 return str;
 219         }
 220
 221         /*
 222          * Extract the name from within the %$(NAME) string.
 223          */
 224
 225         r = p + 3;
 226         copylen = q - r;
 227         envname = (char *)SMB_MALLOC(copylen + 1 + 4); /* reserve space for use later add %$() chars */
 228         if (envname == NULL) return NULL;
 229         strncpy(envname,r,copylen);
 230         envname[copylen] = '\0';
 231
 232         if ((envval = getenv(envname)) == NULL) {
 233                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 234                 SAFE_FREE(envname);
 235                 return str;
 236         }
 237
 238         /*
 239          * Copy the full %$(NAME) into envname so it
 240          * can be replaced.
 241          */
 242
 243         copylen = q + 1 - p;
 244         strncpy(envname,p,copylen);
 245         envname[copylen] = '\0';
 246         r = realloc_string_sub(str, envname, envval);
 247         SAFE_FREE(envname);
 248         if (r == NULL) return NULL;
 249         return r;
 250 }
 251
 252 /*******************************************************************
 253  Patch from jkf@soton.ac.uk
 254  Added this to implement %p (NIS auto-map version of %H)
 255 *******************************************************************/
 256
 257 static char *automount_path(const char *user_name)
 258 {
 259         static pstring server_path;
 260
 261         /* use the passwd entry as the default */
 262         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 263
 264         pstrcpy(server_path, get_user_home_dir(user_name));
 265
 266 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 267
 268         if (lp_nis_home_map()) {
 269                 char *home_path_start;
 270                 char *automount_value = automount_lookup(user_name);
 271
 272                 if(strlen(automount_value) > 0) {
 273                         home_path_start = strchr_m(automount_value,':');
 274                         if (home_path_start != NULL) {
 275                                 DEBUG(5, ("NIS lookup succeeded.  Home path is: %s\n",
 276                                                 home_path_start?(home_path_start+1):""));
 277                                 pstrcpy(server_path, home_path_start+1);
 278                         }
 279                 } else {
 280                         /* NIS key lookup failed: default to user home directory from password file */
 281                         DEBUG(5, ("NIS lookup failed. Using Home path from passwd file. Home path is: %s\n", server_path ));
 282                 }
 283         }
 284 #endif
 285
 286         DEBUG(4,("Home server path: %s\n", server_path));
 287
 288         return server_path;
 289 }
 290
 291 /*******************************************************************
 292  Patch from jkf@soton.ac.uk
 293  This is Luke's original function with the NIS lookup code
 294  moved out to a separate function.
 295 *******************************************************************/
 296
 297 static const char *automount_server(const char *user_name)
 298 {
 299         static pstring server_name;
 300         const char *local_machine_name = get_local_machine_name();
 301
 302         /* use the local machine name as the default */
 303         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 304         if (local_machine_name && *local_machine_name)
 305                 pstrcpy(server_name, local_machine_name);
 306         else
 307                 pstrcpy(server_name, global_myname());
 308
 309 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 310
 311         if (lp_nis_home_map()) {
 312                 int home_server_len;
 313                 char *automount_value = automount_lookup(user_name);
 314                 home_server_len = strcspn(automount_value,":");
 315                 DEBUG(5, ("NIS lookup succeeded.  Home server length: %d\n",home_server_len));
 316                 if (home_server_len > sizeof(pstring))
 317                         home_server_len = sizeof(pstring);
 318                 strncpy(server_name, automount_value, home_server_len);
 319                 server_name[home_server_len] = '\0';
 320         }
 321 #endif
 322
 323         DEBUG(4,("Home server: %s\n", server_name));
 324
 325         return server_name;
 326 }
 327
 328 /****************************************************************************
 329  Do some standard substitutions in a string.
 330  len is the length in bytes of the space allowed in string str. If zero means
 331  don't allow expansions.
 332 ****************************************************************************/
 333
 334 void standard_sub_basic(const char *smb_name, char *str,size_t len)
 335 {
 336         char *p, *s;
 337         fstring pidstr;
 338         struct passwd *pass;
 339         const char *local_machine_name = get_local_machine_name();
 340
 341         for (s=str; (p=strchr_m(s, '%'));s=p) {
 342                 fstring tmp_str;
 343
 344                 int l = (int)len - (int)(p-str);
 345
 346                 if (l < 0)
 347                         l = 0;
 348
 349                 switch (*(p+1)) {
 350                 case 'U' :
 351                         fstrcpy(tmp_str, smb_name);
 352                         strlower_m(tmp_str);
 353                         string_sub(p,"%U",tmp_str,l);
 354                         break;
 355                 case 'G' :
 356                         fstrcpy(tmp_str, smb_name);
 357                         if ((pass = Get_Pwnam(tmp_str))!=NULL) {
 358                                 string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 359                         } else {
 360                                 p += 2;
 361                         }
 362                         break;
 363                 case 'D' :
 364                         fstrcpy(tmp_str, current_user_info.domain);
 365                         strupper_m(tmp_str);
 366                         string_sub(p,"%D", tmp_str,l);
 367                         break;
 368                 case 'I' :
 369                         string_sub(p,"%I", client_addr(),l);
 370                         break;
 371                 case 'i' :
 372                         string_sub(p,"%i", client_socket_addr(),l);
 373                         break;
 374                 case 'L' :
 375                         if (local_machine_name && *local_machine_name)
 376                                 string_sub(p,"%L", local_machine_name,l);
 377                         else {
 378                                 pstring temp_name;
 379
 380                                 pstrcpy(temp_name, global_myname());
 381                                 strlower_m(temp_name);
 382                                 string_sub(p,"%L", temp_name,l);
 383                         }
 384                         break;
 385                 case 'M' :
 386                         string_sub(p,"%M", client_name(),l);
 387                         break;
 388                 case 'R' :
 389                         string_sub(p,"%R", remote_proto,l);
 390                         break;
 391                 case 'T' :
 392                         string_sub(p,"%T", timestring(False),l);
 393                         break;
 394                 case 'a' :
 395                         string_sub(p,"%a", remote_arch,l);
 396                         break;
 397                 case 'd' :
 398                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 399                         string_sub(p,"%d", pidstr,l);
 400                         break;
 401                 case 'h' :
 402                         string_sub(p,"%h", myhostname(),l);
 403                         break;
 404                 case 'm' :
 405                         string_sub(p,"%m", get_remote_machine_name(),l);
 406                         break;
 407                 case 'v' :
 408                         string_sub(p,"%v", SAMBA_VERSION_STRING,l);
 409                         break;
 410                 case '$' :
 411                         p += expand_env_var(p,l);
 412                         break; /* Expand environment variables */
 413                 case '\0':
 414                         p++;
 415                         break; /* don't run off the end of the string */
 416
 417                 default: p+=2;
 418                         break;
 419                 }
 420         }
 421 }
 422
 423 static void standard_sub_advanced(int snum, const char *user,
 424                                   const char *connectpath, gid_t gid,
 425                                   const char *smb_name, char *str, size_t len)
 426 {
 427         char *p, *s, *home;
 428
 429         for (s=str; (p=strchr_m(s, '%'));s=p) {
 430                 int l = (int)len - (int)(p-str);
 431
 432                 if (l < 0)
 433                         l = 0;
 434
 435                 switch (*(p+1)) {
 436                 case 'N' :
 437                         string_sub(p,"%N", automount_server(user),l);
 438                         break;
 439                 case 'H':
 440                         if ((home = get_user_home_dir(user)))
 441                                 string_sub(p,"%H",home, l);
 442                         else
 443                                 p += 2;
 444                         break;
 445                 case 'P':
 446                         string_sub(p,"%P", connectpath, l);
 447                         break;
 448                 case 'S':
 449                         if ( snum != -1 )
 450                                 string_sub(p,"%S", lp_servicename(snum), l);
 451                         break;
 452                 case 'g':
 453                         string_sub(p,"%g", gidtoname(gid), l);
 454                         break;
 455                 case 'u':
 456                         string_sub(p,"%u", user, l);
 457                         break;
 458
 459                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 460                          * server name) in standard_sub_basic as it is
 461                          * a feature for logon servers, hence uses the
 462                          * username.  The %p (NIS server path) code is
 463                          * here as it is used instead of the default
 464                          * "path =" string in [homes] and so needs the
 465                          * service name, not the username.  */
 466                 case 'p':
 467                         if ( snum != -1 )
 468                                 string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 469                         break;
 470                 case '\0':
 471                         p++;
 472                         break; /* don't run off the end of the string */
 473
 474                 default: p+=2;
 475                         break;
 476                 }
 477         }
 478
 479         standard_sub_basic(smb_name, str, len);
 480 }
 481
 482 /****************************************************************************
 483  Do some standard substitutions in a string.
 484  This function will return an allocated string that have to be freed.
 485 ****************************************************************************/
 486
 487 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *str)
 488 {
 489         char *a, *t;
 490         a = alloc_sub_basic(smb_name, str);
 491         if (!a) return NULL;
 492         t = talloc_strdup(mem_ctx, a);
 493         SAFE_FREE(a);
 494         return t;
 495 }
 496
 497 char *alloc_sub_basic(const char *smb_name, const char *str)
 498 {
 499         char *b, *p, *s, *t, *r, *a_string;
 500         fstring pidstr;
 501         struct passwd *pass;
 502         const char *local_machine_name = get_local_machine_name();
 503
 504         /* workaround to prevent a crash while lookinf at bug #687 */
 505
 506         if ( !str ) {
 507                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 508                 return NULL;
 509         }
 510
 511         a_string = SMB_STRDUP(str);
 512         if (a_string == NULL) {
 513                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 514                 return NULL;
 515         }
 516
 517         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 518
 519                 r = NULL;
 520                 b = t = a_string;
 521
 522                 switch (*(p+1)) {
 523                 case 'U' :
 524                         r = strdup_lower(smb_name);
 525                         if (r == NULL) goto error;
 526                         t = realloc_string_sub(t, "%U", r);
 527                         break;
 528                 case 'G' :
 529                         r = SMB_STRDUP(smb_name);
 530                         if (r == NULL) goto error;
 531                         if ((pass = Get_Pwnam(r))!=NULL) {
 532                                 t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
 533                         }
 534                         break;
 535                 case 'D' :
 536                         r = strdup_upper(current_user_info.domain);
 537                         if (r == NULL) goto error;
 538                         t = realloc_string_sub(t, "%D", r);
 539                         break;
 540                 case 'I' :
 541                         t = realloc_string_sub(t, "%I", client_addr());
 542                         break;
 543                 case 'L' :
 544                         if (local_machine_name && *local_machine_name)
 545                                 t = realloc_string_sub(t, "%L", local_machine_name);
 546                         else
 547                                 t = realloc_string_sub(t, "%L", global_myname());
 548                         break;
 549                 case 'N':
 550                         t = realloc_string_sub(t, "%N", automount_server(smb_name));
 551                         break;
 552                 case 'M' :
 553                         t = realloc_string_sub(t, "%M", client_name());
 554                         break;
 555                 case 'R' :
 556                         t = realloc_string_sub(t, "%R", remote_proto);
 557                         break;
 558                 case 'T' :
 559                         t = realloc_string_sub(t, "%T", timestring(False));
 560                         break;
 561                 case 'a' :
 562                         t = realloc_string_sub(t, "%a", remote_arch);
 563                         break;
 564                 case 'd' :
 565                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 566                         t = realloc_string_sub(t, "%d", pidstr);
 567                         break;
 568                 case 'h' :
 569                         t = realloc_string_sub(t, "%h", myhostname());
 570                         break;
 571                 case 'm' :
 572                         t = realloc_string_sub(t, "%m", remote_machine);
 573                         break;
 574                 case 'v' :
 575                         t = realloc_string_sub(t, "%v", SAMBA_VERSION_STRING);
 576                         break;
 577                 case '$' :
 578                         t = realloc_expand_env_var(t, p); /* Expand environment variables */
 579                         break;
 580
 581                 default:
 582                         break;
 583                 }
 584
 585                 p++;
 586                 SAFE_FREE(r);
 587                 if (t == NULL) goto error;
 588                 a_string = t;
 589         }
 590
 591         return a_string;
 592 error:
 593         SAFE_FREE(a_string);
 594         return NULL;
 595 }
 596
 597 /****************************************************************************
 598  Do some specific substitutions in a string.
 599  This function will return an allocated string that have to be freed.
 600 ****************************************************************************/
 601
 602 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 603                         const char *input_string,
 604                         const char *username,
 605                         const char *domain,
 606                         uid_t uid,
 607                         gid_t gid)
 608 {
 609         char *a, *t;
 610         a = alloc_sub_specified(input_string, username, domain, uid, gid);
 611         if (!a) return NULL;
 612         t = talloc_strdup(mem_ctx, a);
 613         SAFE_FREE(a);
 614         return t;
 615 }
 616
 617 char *alloc_sub_specified(const char *input_string,
 618                         const char *username,
 619                         const char *domain,
 620                         uid_t uid,
 621                         gid_t gid)
 622 {
 623         char *a_string, *ret_string;
 624         char *b, *p, *s, *t;
 625
 626         a_string = SMB_STRDUP(input_string);
 627         if (a_string == NULL) {
 628                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 629                 return NULL;
 630         }
 631
 632         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 633
 634                 b = t = a_string;
 635
 636                 switch (*(p+1)) {
 637                 case 'U' :
 638                         t = realloc_string_sub(t, "%U", username);
 639                         break;
 640                 case 'u' :
 641                         t = realloc_string_sub(t, "%u", username);
 642                         break;
 643                 case 'G' :
 644                         if (gid != -1) {
 645                                 t = realloc_string_sub(t, "%G", gidtoname(gid));
 646                         } else {
 647                                 t = realloc_string_sub(t, "%G", "NO_GROUP");
 648                         }
 649                         break;
 650                 case 'g' :
 651                         if (gid != -1) {
 652                                 t = realloc_string_sub(t, "%g", gidtoname(gid));
 653                         } else {
 654                                 t = realloc_string_sub(t, "%g", "NO_GROUP");
 655                         }
 656                         break;
 657                 case 'D' :
 658                         t = realloc_string_sub(t, "%D", domain);
 659                         break;
 660                 case 'N' :
 661                         t = realloc_string_sub(t, "%N", automount_server(username));
 662                         break;
 663                 default:
 664                         break;
 665                 }
 666
 667                 p++;
 668                 if (t == NULL) {
 669                         SAFE_FREE(a_string);
 670                         return NULL;
 671                 }
 672                 a_string = t;
 673         }
 674
 675         ret_string = alloc_sub_basic(username, a_string);
 676         SAFE_FREE(a_string);
 677         return ret_string;
 678 }
 679
 680 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 681                         int snum,
 682                         const char *user,
 683                         const char *connectpath,
 684                         gid_t gid,
 685                         const char *smb_name,
 686                         const char *str)
 687 {
 688         char *a, *t;
 689         a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
 690         if (!a) return NULL;
 691         t = talloc_strdup(mem_ctx, a);
 692         SAFE_FREE(a);
 693         return t;
 694 }
 695
 696 char *alloc_sub_advanced(int snum, const char *user,
 697                                   const char *connectpath, gid_t gid,
 698                                   const char *smb_name, const char *str)
 699 {
 700         char *a_string, *ret_string;
 701         char *b, *p, *s, *t, *h;
 702
 703         a_string = SMB_STRDUP(str);
 704         if (a_string == NULL) {
 705                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 706                 return NULL;
 707         }
 708
 709         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 710
 711                 b = t = a_string;
 712
 713                 switch (*(p+1)) {
 714                 case 'N' :
 715                         t = realloc_string_sub(t, "%N", automount_server(user));
 716                         break;
 717                 case 'H':
 718                         if ((h = get_user_home_dir(user)))
 719                                 t = realloc_string_sub(t, "%H", h);
 720                         break;
 721                 case 'P':
 722                         t = realloc_string_sub(t, "%P", connectpath);
 723                         break;
 724                 case 'S':
 725                         t = realloc_string_sub(t, "%S", lp_servicename(snum));
 726                         break;
 727                 case 'g':
 728                         t = realloc_string_sub(t, "%g", gidtoname(gid));
 729                         break;
 730                 case 'u':
 731                         t = realloc_string_sub(t, "%u", user);
 732                         break;
 733
 734                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 735                          * server name) in standard_sub_basic as it is
 736                          * a feature for logon servers, hence uses the
 737                          * username.  The %p (NIS server path) code is
 738                          * here as it is used instead of the default
 739                          * "path =" string in [homes] and so needs the
 740                          * service name, not the username.  */
 741                 case 'p':
 742                         t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum)));
 743                         break;
 744
 745                 default:
 746                         break;
 747                 }
 748
 749                 p++;
 750                 if (t == NULL) {
 751                         SAFE_FREE(a_string);
 752                         return NULL;
 753                 }
 754                 a_string = t;
 755         }
 756
 757         ret_string = alloc_sub_basic(smb_name, a_string);
 758         SAFE_FREE(a_string);
 759         return ret_string;
 760 }
 761
 762 /****************************************************************************
 763  Do some standard substitutions in a string.
 764 ****************************************************************************/
 765
 766 void standard_sub_conn(connection_struct *conn, char *str, size_t len)
 767 {
 768         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 769                         conn->gid, smb_user_name, str, len);
 770 }
 771
 772 char *talloc_sub_conn(TALLOC_CTX *mem_ctx, connection_struct *conn, const char *str)
 773 {
 774         return talloc_sub_advanced(mem_ctx, SNUM(conn), conn->user,
 775                         conn->connectpath, conn->gid,
 776                         smb_user_name, str);
 777 }
 778
 779 char *alloc_sub_conn(connection_struct *conn, const char *str)
 780 {
 781         return alloc_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 782                         conn->gid, smb_user_name, str);
 783 }
 784
 785 /****************************************************************************
 786  Like standard_sub but by snum.
 787 ****************************************************************************/
 788
 789 void standard_sub_snum(int snum, char *str, size_t len)
 790 {
 791         extern struct current_user current_user;
 792         static uid_t cached_uid = -1;
 793         static fstring cached_user;
 794         /* calling uidtoname() on every substitute would be too expensive, so
 795            we cache the result here as nearly every call is for the same uid */
 796
 797         if (cached_uid != current_user.uid) {
 798                 fstrcpy(cached_user, uidtoname(current_user.uid));
 799                 cached_uid = current_user.uid;
 800         }
 801
 802         standard_sub_advanced(snum, cached_user, "", current_user.gid,
 803                               smb_user_name, str, len);
 804 }