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 (strequal(local_name, "*SMBSERVER"))
  49                 return;
  50
  51         if (strequal(local_name, "*SMBSERV"))
  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 'i' :
 367                         string_sub(p,"%i", client_socket_addr(),l);
 368                         break;
 369                 case 'L' :
 370                         if (local_machine_name && *local_machine_name)
 371                                 string_sub(p,"%L", local_machine_name,l);
 372                         else {
 373                                 pstring temp_name;
 374
 375                                 pstrcpy(temp_name, global_myname());
 376                                 strlower_m(temp_name);
 377                                 string_sub(p,"%L", temp_name,l);
 378                         }
 379                         break;
 380                 case 'M' :
 381                         string_sub(p,"%M", client_name(),l);
 382                         break;
 383                 case 'R' :
 384                         string_sub(p,"%R", remote_proto,l);
 385                         break;
 386                 case 'T' :
 387                         string_sub(p,"%T", timestring(False),l);
 388                         break;
 389                 case 'a' :
 390                         string_sub(p,"%a", remote_arch,l);
 391                         break;
 392                 case 'd' :
 393                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 394                         string_sub(p,"%d", pidstr,l);
 395                         break;
 396                 case 'h' :
 397                         string_sub(p,"%h", myhostname(),l);
 398                         break;
 399                 case 'm' :
 400                         string_sub(p,"%m", get_remote_machine_name(),l);
 401                         break;
 402                 case 'v' :
 403                         string_sub(p,"%v", SAMBA_VERSION_STRING,l);
 404                         break;
 405                 case '$' :
 406                         p += expand_env_var(p,l);
 407                         break; /* Expand environment variables */
 408                 case '\0':
 409                         p++;
 410                         break; /* don't run off the end of the string */
 411
 412                 default: p+=2;
 413                         break;
 414                 }
 415         }
 416 }
 417
 418 static void standard_sub_advanced(int snum, const char *user,
 419                                   const char *connectpath, gid_t gid,
 420                                   const char *smb_name, char *str, size_t len)
 421 {
 422         char *p, *s, *home;
 423
 424         for (s=str; (p=strchr_m(s, '%'));s=p) {
 425                 int l = (int)len - (int)(p-str);
 426
 427                 if (l < 0)
 428                         l = 0;
 429
 430                 switch (*(p+1)) {
 431                 case 'N' :
 432                         string_sub(p,"%N", automount_server(user),l);
 433                         break;
 434                 case 'H':
 435                         if ((home = get_user_home_dir(user)))
 436                                 string_sub(p,"%H",home, l);
 437                         else
 438                                 p += 2;
 439                         break;
 440                 case 'P':
 441                         string_sub(p,"%P", connectpath, l);
 442                         break;
 443                 case 'S':
 444                         string_sub(p,"%S", lp_servicename(snum), l);
 445                         break;
 446                 case 'g':
 447                         string_sub(p,"%g", gidtoname(gid), l);
 448                         break;
 449                 case 'u':
 450                         string_sub(p,"%u", user, l);
 451                         break;
 452
 453                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 454                          * server name) in standard_sub_basic as it is
 455                          * a feature for logon servers, hence uses the
 456                          * username.  The %p (NIS server path) code is
 457                          * here as it is used instead of the default
 458                          * "path =" string in [homes] and so needs the
 459                          * service name, not the username.  */
 460                 case 'p':
 461                         string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 462                         break;
 463                 case '\0':
 464                         p++;
 465                         break; /* don't run off the end of the string */
 466
 467                 default: p+=2;
 468                         break;
 469                 }
 470         }
 471
 472         standard_sub_basic(smb_name, str, len);
 473 }
 474
 475 /****************************************************************************
 476  Do some standard substitutions in a string.
 477  This function will return an allocated string that have to be freed.
 478 ****************************************************************************/
 479
 480 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *str)
 481 {
 482         char *a, *t;
 483         a = alloc_sub_basic(smb_name, str);
 484         if (!a) return NULL;
 485         t = talloc_strdup(mem_ctx, a);
 486         SAFE_FREE(a);
 487         return t;
 488 }
 489
 490 char *alloc_sub_basic(const char *smb_name, const char *str)
 491 {
 492         char *b, *p, *s, *t, *r, *a_string;
 493         fstring pidstr;
 494         struct passwd *pass;
 495         const char *local_machine_name = get_local_machine_name();
 496
 497         /* workaround to prevent a crash while lookinf at bug #687 */
 498
 499         if ( !str ) {
 500                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 501                 return NULL;
 502         }
 503
 504         a_string = strdup(str);
 505         if (a_string == NULL) {
 506                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 507                 return NULL;
 508         }
 509
 510         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 511
 512                 r = NULL;
 513                 b = t = a_string;
 514
 515                 switch (*(p+1)) {
 516                 case 'U' :
 517                         r = strdup_lower(smb_name);
 518                         if (r == NULL) goto error;
 519                         t = realloc_string_sub(t, "%U", r);
 520                         break;
 521                 case 'G' :
 522                         r = strdup(smb_name);
 523                         if (r == NULL) goto error;
 524                         if ((pass = Get_Pwnam(r))!=NULL) {
 525                                 t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
 526                         }
 527                         break;
 528                 case 'D' :
 529                         r = strdup_upper(current_user_info.domain);
 530                         if (r == NULL) goto error;
 531                         t = realloc_string_sub(t, "%D", r);
 532                         break;
 533                 case 'I' :
 534                         t = realloc_string_sub(t, "%I", client_addr());
 535                         break;
 536                 case 'L' :
 537                         if (local_machine_name && *local_machine_name)
 538                                 t = realloc_string_sub(t, "%L", local_machine_name);
 539                         else
 540                                 t = realloc_string_sub(t, "%L", global_myname());
 541                         break;
 542                 case 'N':
 543                         t = realloc_string_sub(t, "%N", automount_server(smb_name));
 544                         break;
 545                 case 'M' :
 546                         t = realloc_string_sub(t, "%M", client_name());
 547                         break;
 548                 case 'R' :
 549                         t = realloc_string_sub(t, "%R", remote_proto);
 550                         break;
 551                 case 'T' :
 552                         t = realloc_string_sub(t, "%T", timestring(False));
 553                         break;
 554                 case 'a' :
 555                         t = realloc_string_sub(t, "%a", remote_arch);
 556                         break;
 557                 case 'd' :
 558                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 559                         t = realloc_string_sub(t, "%d", pidstr);
 560                         break;
 561                 case 'h' :
 562                         t = realloc_string_sub(t, "%h", myhostname());
 563                         break;
 564                 case 'm' :
 565                         t = realloc_string_sub(t, "%m", remote_machine);
 566                         break;
 567                 case 'v' :
 568                         t = realloc_string_sub(t, "%v", SAMBA_VERSION_STRING);
 569                         break;
 570                 case '$' :
 571                         t = realloc_expand_env_var(t, p); /* Expand environment variables */
 572                         break;
 573
 574                 default:
 575                         break;
 576                 }
 577
 578                 p++;
 579                 SAFE_FREE(r);
 580                 if (t == NULL) goto error;
 581                 a_string = t;
 582         }
 583
 584         return a_string;
 585 error:
 586         SAFE_FREE(a_string);
 587         return NULL;
 588 }
 589
 590 /****************************************************************************
 591  Do some specific substitutions in a string.
 592  This function will return an allocated string that have to be freed.
 593 ****************************************************************************/
 594
 595 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 596                         const char *input_string,
 597                         const char *username,
 598                         const char *domain,
 599                         uid_t uid,
 600                         gid_t gid)
 601 {
 602         char *a, *t;
 603         a = alloc_sub_specified(input_string, username, domain, uid, gid);
 604         if (!a) return NULL;
 605         t = talloc_strdup(mem_ctx, a);
 606         SAFE_FREE(a);
 607         return t;
 608 }
 609
 610 char *alloc_sub_specified(const char *input_string,
 611                         const char *username,
 612                         const char *domain,
 613                         uid_t uid,
 614                         gid_t gid)
 615 {
 616         char *a_string, *ret_string;
 617         char *b, *p, *s, *t;
 618
 619         a_string = strdup(input_string);
 620         if (a_string == NULL) {
 621                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 622                 return NULL;
 623         }
 624
 625         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 626
 627                 b = t = a_string;
 628
 629                 switch (*(p+1)) {
 630                 case 'U' :
 631                         t = realloc_string_sub(t, "%U", username);
 632                         break;
 633                 case 'u' :
 634                         t = realloc_string_sub(t, "%u", username);
 635                         break;
 636                 case 'G' :
 637                         if (gid != -1) {
 638                                 t = realloc_string_sub(t, "%G", gidtoname(gid));
 639                         } else {
 640                                 t = realloc_string_sub(t, "%G", "NO_GROUP");
 641                         }
 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 'D' :
 651                         t = realloc_string_sub(t, "%D", domain);
 652                         break;
 653                 case 'N' :
 654                         t = realloc_string_sub(t, "%N", automount_server(username));
 655                         break;
 656                 default:
 657                         break;
 658                 }
 659
 660                 p++;
 661                 if (t == NULL) {
 662                         SAFE_FREE(a_string);
 663                         return NULL;
 664                 }
 665                 a_string = t;
 666         }
 667
 668         ret_string = alloc_sub_basic(username, a_string);
 669         SAFE_FREE(a_string);
 670         return ret_string;
 671 }
 672
 673 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 674                         int snum,
 675                         const char *user,
 676                         const char *connectpath,
 677                         gid_t gid,
 678                         const char *smb_name,
 679                         const char *str)
 680 {
 681         char *a, *t;
 682         a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
 683         if (!a) return NULL;
 684         t = talloc_strdup(mem_ctx, a);
 685         SAFE_FREE(a);
 686         return t;
 687 }
 688
 689 char *alloc_sub_advanced(int snum, const char *user,
 690                                   const char *connectpath, gid_t gid,
 691                                   const char *smb_name, const char *str)
 692 {
 693         char *a_string, *ret_string;
 694         char *b, *p, *s, *t, *h;
 695
 696         a_string = strdup(str);
 697         if (a_string == NULL) {
 698                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 699                 return NULL;
 700         }
 701
 702         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 703
 704                 b = t = a_string;
 705
 706                 switch (*(p+1)) {
 707                 case 'N' :
 708                         t = realloc_string_sub(t, "%N", automount_server(user));
 709                         break;
 710                 case 'H':
 711                         if ((h = get_user_home_dir(user)))
 712                                 t = realloc_string_sub(t, "%H", h);
 713                         break;
 714                 case 'P':
 715                         t = realloc_string_sub(t, "%P", connectpath);
 716                         break;
 717                 case 'S':
 718                         t = realloc_string_sub(t, "%S", lp_servicename(snum));
 719                         break;
 720                 case 'g':
 721                         t = realloc_string_sub(t, "%g", gidtoname(gid));
 722                         break;
 723                 case 'u':
 724                         t = realloc_string_sub(t, "%u", user);
 725                         break;
 726
 727                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 728                          * server name) in standard_sub_basic as it is
 729                          * a feature for logon servers, hence uses the
 730                          * username.  The %p (NIS server path) code is
 731                          * here as it is used instead of the default
 732                          * "path =" string in [homes] and so needs the
 733                          * service name, not the username.  */
 734                 case 'p':
 735                         t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum)));
 736                         break;
 737
 738                 default:
 739                         break;
 740                 }
 741
 742                 p++;
 743                 if (t == NULL) {
 744                         SAFE_FREE(a_string);
 745                         return NULL;
 746                 }
 747                 a_string = t;
 748         }
 749
 750         ret_string = alloc_sub_basic(smb_name, a_string);
 751         SAFE_FREE(a_string);
 752         return ret_string;
 753 }
 754
 755 /****************************************************************************
 756  Do some standard substitutions in a string.
 757 ****************************************************************************/
 758
 759 void standard_sub_conn(connection_struct *conn, char *str, size_t len)
 760 {
 761         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 762                         conn->gid, smb_user_name, str, len);
 763 }
 764
 765 char *talloc_sub_conn(TALLOC_CTX *mem_ctx, connection_struct *conn, const char *str)
 766 {
 767         return talloc_sub_advanced(mem_ctx, SNUM(conn), conn->user,
 768                         conn->connectpath, conn->gid,
 769                         smb_user_name, str);
 770 }
 771
 772 char *alloc_sub_conn(connection_struct *conn, const char *str)
 773 {
 774         return alloc_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 775                         conn->gid, smb_user_name, str);
 776 }
 777
 778 /****************************************************************************
 779  Like standard_sub but by snum.
 780 ****************************************************************************/
 781
 782 void standard_sub_snum(int snum, char *str, size_t len)
 783 {
 784         extern struct current_user current_user;
 785         static uid_t cached_uid = -1;
 786         static fstring cached_user;
 787         /* calling uidtoname() on every substitute would be too expensive, so
 788            we cache the result here as nearly every call is for the same uid */
 789
 790         if (cached_uid != current_user.uid) {
 791                 fstrcpy(cached_user, uidtoname(current_user.uid));
 792                 cached_uid = current_user.uid;
 793         }
 794
 795         standard_sub_advanced(snum, cached_user, "", -1,
 796                               smb_user_name, str, len);
 797 }