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 extern pstring global_myname;
  29
  30 static fstring remote_machine="";
  31
  32
  33 void set_local_machine_name(const char* local_name)
  34 {
  35         fstring tmp_local_machine;
  36
  37         fstrcpy(tmp_local_machine,local_name);
  38         trim_string(tmp_local_machine," "," ");
  39         strlower(tmp_local_machine);
  40         alpha_strcpy(local_machine,tmp_local_machine,SAFE_NETBIOS_CHARS,sizeof(local_machine)-1);
  41 }
  42
  43 void set_remote_machine_name(const char* remote_name)
  44 {
  45         fstring tmp_remote_machine;
  46
  47         fstrcpy(tmp_remote_machine,remote_name);
  48         trim_string(tmp_remote_machine," "," ");
  49         strlower(tmp_remote_machine);
  50         alpha_strcpy(remote_machine,tmp_remote_machine,SAFE_NETBIOS_CHARS,sizeof(remote_machine)-1);
  51 }
  52
  53 const char* get_remote_machine_name(void)
  54 {
  55         return remote_machine;
  56 }
  57
  58 const char* get_local_machine_name(void)
  59 {
  60         return local_machine;
  61 }
  62
  63 /*******************************************************************
  64  Given a pointer to a %$(NAME) expand it as an environment variable.
  65  Return the number of characters by which the pointer should be advanced.
  66  Based on code by Branko Cibej <branko.cibej@hermes.si>
  67  When this is called p points at the '%' character.
  68 ********************************************************************/
  69
  70 static size_t expand_env_var(char *p, int len)
  71 {
  72         fstring envname;
  73         char *envval;
  74         char *q, *r;
  75         int copylen;
  76
  77         if (p[1] != '$')
  78                 return 1;
  79
  80         if (p[2] != '(')
  81                 return 2;
  82
  83         /*
  84          * Look for the terminating ')'.
  85          */
  86
  87         if ((q = strchr_m(p,')')) == NULL) {
  88                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
  89                 return 2;
  90         }
  91
  92         /*
  93          * Extract the name from within the %$(NAME) string.
  94          */
  95
  96         r = p+3;
  97         copylen = MIN((q-r),(sizeof(envname)-1));
  98         strncpy(envname,r,copylen);
  99         envname[copylen] = '\0';
 100
 101         if ((envval = getenv(envname)) == NULL) {
 102                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 103                 return 2;
 104         }
 105
 106         /*
 107          * Copy the full %$(NAME) into envname so it
 108          * can be replaced.
 109          */
 110
 111         copylen = MIN((q+1-p),(sizeof(envname)-1));
 112         strncpy(envname,p,copylen);
 113         envname[copylen] = '\0';
 114         string_sub(p,envname,envval,len);
 115         return 0; /* Allow the environment contents to be parsed. */
 116 }
 117
 118 /*******************************************************************
 119  Given a pointer to a %$(NAME) in p and the whole string in str
 120  expand it as an environment variable.
 121  Return a new allocated and expanded string.
 122  Based on code by Branko Cibej <branko.cibej@hermes.si>
 123  When this is called p points at the '%' character.
 124  May substitute multiple occurrencies of the same env var.
 125 ********************************************************************/
 126
 127
 128 static char * realloc_expand_env_var(char *str, char *p)
 129 {
 130         char *envname;
 131         char *envval;
 132         char *q, *r;
 133         int copylen;
 134
 135         if (p[0] != '%' || p[1] != '$' || p[2] != '(')
 136                 return str;
 137
 138         /*
 139          * Look for the terminating ')'.
 140          */
 141
 142         if ((q = strchr_m(p,')')) == NULL) {
 143                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 144                 return str;
 145         }
 146
 147         /*
 148          * Extract the name from within the %$(NAME) string.
 149          */
 150
 151         r = p + 3;
 152         copylen = q - r;
 153         envname = (char *)malloc(copylen + 1 + 4); /* reserve space for use later add %$() chars */
 154         if (envname == NULL) return NULL;
 155         strncpy(envname,r,copylen);
 156         envname[copylen] = '\0';
 157
 158         if ((envval = getenv(envname)) == NULL) {
 159                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 160                 SAFE_FREE(envname);
 161                 return str;
 162         }
 163
 164         /*
 165          * Copy the full %$(NAME) into envname so it
 166          * can be replaced.
 167          */
 168
 169         copylen = q + 1 - p;
 170         strncpy(envname,p,copylen);
 171         envname[copylen] = '\0';
 172         r = realloc_string_sub(str, envname, envval);
 173         SAFE_FREE(envname);
 174         if (r == NULL) return NULL;
 175         return r;
 176 }
 177
 178 /*******************************************************************
 179  Patch from jkf@soton.ac.uk
 180  Added this to implement %p (NIS auto-map version of %H)
 181 *******************************************************************/
 182
 183 static char *automount_path(const char *user_name)
 184 {
 185         static pstring server_path;
 186
 187         /* use the passwd entry as the default */
 188         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 189
 190         pstrcpy(server_path, get_user_home_dir(user_name));
 191
 192 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 193
 194         if (lp_nis_home_map()) {
 195                 char *home_path_start;
 196                 char *automount_value = automount_lookup(user_name);
 197
 198                 if(strlen(automount_value) > 0) {
 199                         home_path_start = strchr_m(automount_value,':');
 200                         if (home_path_start != NULL) {
 201                                 DEBUG(5, ("NIS lookup succeeded.  Home path is: %s\n",
 202                                                 home_path_start?(home_path_start+1):""));
 203                                 pstrcpy(server_path, home_path_start+1);
 204                         }
 205                 } else {
 206                         /* NIS key lookup failed: default to user home directory from password file */
 207                         DEBUG(5, ("NIS lookup failed. Using Home path from passwd file. Home path is: %s\n", server_path ));
 208                 }
 209         }
 210 #endif
 211
 212         DEBUG(4,("Home server path: %s\n", server_path));
 213
 214         return server_path;
 215 }
 216
 217 /*******************************************************************
 218  Patch from jkf@soton.ac.uk
 219  This is Luke's original function with the NIS lookup code
 220  moved out to a separate function.
 221 *******************************************************************/
 222
 223 static const char *automount_server(const char *user_name)
 224 {
 225         static pstring server_name;
 226         const char *local_machine_name = get_local_machine_name();
 227
 228         /* use the local machine name as the default */
 229         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 230         if (local_machine_name && *local_machine_name)
 231                 pstrcpy(server_name, local_machine_name);
 232         else
 233                 pstrcpy(server_name, global_myname);
 234
 235 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 236
 237         if (lp_nis_home_map()) {
 238                 int home_server_len;
 239                 char *automount_value = automount_lookup(user_name);
 240                 home_server_len = strcspn(automount_value,":");
 241                 DEBUG(5, ("NIS lookup succeeded.  Home server length: %d\n",home_server_len));
 242                 if (home_server_len > sizeof(pstring))
 243                         home_server_len = sizeof(pstring);
 244                 strncpy(server_name, automount_value, home_server_len);
 245                 server_name[home_server_len] = '\0';
 246         }
 247 #endif
 248
 249         DEBUG(4,("Home server: %s\n", server_name));
 250
 251         return server_name;
 252 }
 253
 254 /****************************************************************************
 255  Do some standard substitutions in a string.
 256  len is the length in bytes of the space allowed in string str. If zero means
 257  don't allow expansions.
 258 ****************************************************************************/
 259
 260 void standard_sub_basic(const char *smb_name, char *str,size_t len)
 261 {
 262         char *p, *s;
 263         fstring pidstr;
 264         struct passwd *pass;
 265         const char *local_machine_name = get_local_machine_name();
 266
 267         for (s=str; (p=strchr_m(s, '%'));s=p) {
 268                 fstring tmp_str;
 269
 270                 int l = (int)len - (int)(p-str);
 271
 272                 if (l < 0)
 273                         l = 0;
 274
 275                 switch (*(p+1)) {
 276                 case 'U' :
 277                         fstrcpy(tmp_str, smb_name);
 278                         strlower(tmp_str);
 279                         string_sub(p,"%U",tmp_str,l);
 280                         break;
 281                 case 'G' :
 282                         fstrcpy(tmp_str, smb_name);
 283                         if ((pass = Get_Pwnam(tmp_str))!=NULL) {
 284                                 string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 285                         } else {
 286                                 p += 2;
 287                         }
 288                         break;
 289                 case 'D' :
 290                         fstrcpy(tmp_str, current_user_info.domain);
 291                         strupper(tmp_str);
 292                         string_sub(p,"%D", tmp_str,l);
 293                         break;
 294                 case 'I' :
 295                         string_sub(p,"%I", client_addr(),l);
 296                         break;
 297                 case 'L' :
 298                         if (local_machine_name && *local_machine_name)
 299                                 string_sub(p,"%L", local_machine_name,l);
 300                         else {
 301                                 pstring temp_name;
 302
 303                                 pstrcpy(temp_name, global_myname);
 304                                 strlower(temp_name);
 305                                 string_sub(p,"%L", temp_name,l);
 306                         }
 307                         break;
 308                 case 'M' :
 309                         string_sub(p,"%M", client_name(),l);
 310                         break;
 311                 case 'R' :
 312                         string_sub(p,"%R", remote_proto,l);
 313                         break;
 314                 case 'T' :
 315                         string_sub(p,"%T", timestring(False),l);
 316                         break;
 317                 case 'a' :
 318                         string_sub(p,"%a", remote_arch,l);
 319                         break;
 320                 case 'd' :
 321                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 322                         string_sub(p,"%d", pidstr,l);
 323                         break;
 324                 case 'h' :
 325                         string_sub(p,"%h", myhostname(),l);
 326                         break;
 327                 case 'm' :
 328                         string_sub(p,"%m", get_remote_machine_name(),l);
 329                         break;
 330                 case 'v' :
 331                         string_sub(p,"%v", VERSION,l);
 332                         break;
 333                 case '$' :
 334                         p += expand_env_var(p,l);
 335                         break; /* Expand environment variables */
 336                 case '\0':
 337                         p++;
 338                         break; /* don't run off the end of the string */
 339
 340                 default: p+=2;
 341                         break;
 342                 }
 343         }
 344 }
 345
 346 static void standard_sub_advanced(int snum, const char *user,
 347                                   const char *connectpath, gid_t gid,
 348                                   const char *smb_name, char *str, size_t len)
 349 {
 350         char *p, *s, *home;
 351
 352         for (s=str; (p=strchr_m(s, '%'));s=p) {
 353                 int l = (int)len - (int)(p-str);
 354
 355                 if (l < 0)
 356                         l = 0;
 357
 358                 switch (*(p+1)) {
 359                 case 'N' :
 360                         string_sub(p,"%N", automount_server(user),l);
 361                         break;
 362                 case 'H':
 363                         if ((home = get_user_home_dir(user)))
 364                                 string_sub(p,"%H",home, l);
 365                         else
 366                                 p += 2;
 367                         break;
 368                 case 'P':
 369                         string_sub(p,"%P", connectpath, l);
 370                         break;
 371                 case 'S':
 372                         string_sub(p,"%S", lp_servicename(snum), l);
 373                         break;
 374                 case 'g':
 375                         string_sub(p,"%g", gidtoname(gid), l);
 376                         break;
 377                 case 'u':
 378                         string_sub(p,"%u", user, l);
 379                         break;
 380
 381                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 382                          * server name) in standard_sub_basic as it is
 383                          * a feature for logon servers, hence uses the
 384                          * username.  The %p (NIS server path) code is
 385                          * here as it is used instead of the default
 386                          * "path =" string in [homes] and so needs the
 387                          * service name, not the username.  */
 388                 case 'p':
 389                         string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 390                         break;
 391                 case '\0':
 392                         p++;
 393                         break; /* don't run off the end of the string */
 394
 395                 default: p+=2;
 396                         break;
 397                 }
 398         }
 399
 400         standard_sub_basic(smb_name, str, len);
 401 }
 402
 403 /****************************************************************************
 404  Do some standard substitutions in a string.
 405  This function will return an allocated string that have to be freed.
 406 ****************************************************************************/
 407
 408 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *str)
 409 {
 410         char *a, *t;
 411         a = alloc_sub_basic(smb_name, str);
 412         if (!a) return NULL;
 413         t = talloc_strdup(mem_ctx, a);
 414         SAFE_FREE(a);
 415         return t;
 416 }
 417
 418 char *alloc_sub_basic(const char *smb_name, const char *str)
 419 {
 420         char *b, *p, *s, *t, *r, *a_string;
 421         fstring pidstr;
 422         struct passwd *pass;
 423         const char *local_machine_name = get_local_machine_name();
 424
 425         a_string = strdup(str);
 426         if (a_string == NULL) {
 427                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 428                 return NULL;
 429         }
 430
 431         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 432
 433                 r = NULL;
 434                 b = t = a_string;
 435
 436                 switch (*(p+1)) {
 437                 case 'U' :
 438                         r = strdup_lower(smb_name);
 439                         if (r == NULL) goto error;
 440                         t = realloc_string_sub(t, "%U", r);
 441                         break;
 442                 case 'G' :
 443                         r = strdup(smb_name);
 444                         if (r == NULL) goto error;
 445                         if ((pass = Get_Pwnam(r))!=NULL) {
 446                                 t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
 447                         }
 448                         break;
 449                 case 'D' :
 450                         r = strdup_upper(current_user_info.domain);
 451                         if (r == NULL) goto error;
 452                         t = realloc_string_sub(t, "%D", r);
 453                         break;
 454                 case 'I' :
 455                         t = realloc_string_sub(t, "%I", client_addr());
 456                         break;
 457                 case 'L' :
 458                         if (local_machine_name && *local_machine_name)
 459                                 t = realloc_string_sub(t, "%L", local_machine_name);
 460                         else
 461                                 t = realloc_string_sub(t, "%L", global_myname);
 462                         break;
 463                 case 'M' :
 464                         t = realloc_string_sub(t, "%M", client_name());
 465                         break;
 466                 case 'R' :
 467                         t = realloc_string_sub(t, "%R", remote_proto);
 468                         break;
 469                 case 'T' :
 470                         t = realloc_string_sub(t, "%T", timestring(False));
 471                         break;
 472                 case 'a' :
 473                         t = realloc_string_sub(t, "%a", remote_arch);
 474                         break;
 475                 case 'd' :
 476                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 477                         t = realloc_string_sub(t, "%d", pidstr);
 478                         break;
 479                 case 'h' :
 480                         t = realloc_string_sub(t, "%h", myhostname());
 481                         break;
 482                 case 'm' :
 483                         t = realloc_string_sub(t, "%m", remote_machine);
 484                         break;
 485                 case 'v' :
 486                         t = realloc_string_sub(t, "%v", VERSION);
 487                         break;
 488                 case '$' :
 489                         t = realloc_expand_env_var(t, p); /* Expand environment variables */
 490                         break;
 491
 492                 default:
 493                         break;
 494                 }
 495
 496                 p++;
 497                 SAFE_FREE(r);
 498                 if (t == NULL) goto error;
 499                 a_string = t;
 500         }
 501
 502         return a_string;
 503 error:
 504         SAFE_FREE(a_string);
 505         return NULL;
 506 }
 507
 508 /****************************************************************************
 509  Do some specific substitutions in a string.
 510  This function will return an allocated string that have to be freed.
 511 ****************************************************************************/
 512
 513 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 514                         const char *input_string,
 515                         const char *username,
 516                         const char *domain,
 517                         uid_t uid,
 518                         gid_t gid)
 519 {
 520         char *a, *t;
 521         a = alloc_sub_specified(input_string, username, domain, uid, gid);
 522         if (!a) return NULL;
 523         t = talloc_strdup(mem_ctx, a);
 524         SAFE_FREE(a);
 525         return t;
 526 }
 527
 528 char *alloc_sub_specified(const char *input_string,
 529                         const char *username,
 530                         const char *domain,
 531                         uid_t uid,
 532                         gid_t gid)
 533 {
 534         char *a_string, *ret_string;
 535         char *b, *p, *s, *t;
 536
 537         a_string = strdup(input_string);
 538         if (a_string == NULL) {
 539                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 540                 return NULL;
 541         }
 542
 543         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 544
 545                 b = t = a_string;
 546
 547                 switch (*(p+1)) {
 548                 case 'U' :
 549                         t = realloc_string_sub(t, "%U", username);
 550                         break;
 551                 case 'u' :
 552                         t = realloc_string_sub(t, "%u", username);
 553                         break;
 554                 case 'G' :
 555                         if (gid != -1) {
 556                                 t = realloc_string_sub(t, "%G", gidtoname(gid));
 557                         } else {
 558                                 t = realloc_string_sub(t, "%G", "NO_GROUP");
 559                         }
 560                         break;
 561                 case 'g' :
 562                         if (gid != -1) {
 563                                 t = realloc_string_sub(t, "%g", gidtoname(gid));
 564                         } else {
 565                                 t = realloc_string_sub(t, "%g", "NO_GROUP");
 566                         }
 567                         break;
 568                 case 'D' :
 569                         t = realloc_string_sub(t, "%D", domain);
 570                         break;
 571                 case 'N' :
 572                         t = realloc_string_sub(t, "%N", automount_server(username));
 573                         break;
 574                 default:
 575                         break;
 576                 }
 577
 578                 p++;
 579                 if (t == NULL) {
 580                         SAFE_FREE(a_string);
 581                         return NULL;
 582                 }
 583                 a_string = t;
 584         }
 585
 586         ret_string = alloc_sub_basic(username, a_string);
 587         SAFE_FREE(a_string);
 588         return ret_string;
 589 }
 590
 591 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 592                         int snum,
 593                         const char *user,
 594                         const char *connectpath,
 595                         gid_t gid,
 596                         const char *smb_name,
 597                         char *str)
 598 {
 599         char *a, *t;
 600         a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
 601         if (!a) return NULL;
 602         t = talloc_strdup(mem_ctx, a);
 603         SAFE_FREE(a);
 604         return t;
 605 }
 606
 607 char *alloc_sub_advanced(int snum, const char *user,
 608                                   const char *connectpath, gid_t gid,
 609                                   const char *smb_name, char *str)
 610 {
 611         char *a_string, *ret_string;
 612         char *b, *p, *s, *t, *h;
 613
 614         a_string = strdup(str);
 615         if (a_string == NULL) {
 616                 DEBUG(0, ("alloc_sub_specified: Out of memory!\n"));
 617                 return NULL;
 618         }
 619
 620         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 621
 622                 b = t = a_string;
 623
 624                 switch (*(p+1)) {
 625                 case 'N' :
 626                         t = realloc_string_sub(t, "%N", automount_server(user));
 627                         break;
 628                 case 'H':
 629                         if ((h = get_user_home_dir(user)))
 630                                 t = realloc_string_sub(t, "%H", h);
 631                         break;
 632                 case 'P':
 633                         t = realloc_string_sub(t, "%P", connectpath);
 634                         break;
 635                 case 'S':
 636                         t = realloc_string_sub(t, "%S", lp_servicename(snum));
 637                         break;
 638                 case 'g':
 639                         t = realloc_string_sub(t, "%g", gidtoname(gid));
 640                         break;
 641                 case 'u':
 642                         t = realloc_string_sub(t, "%u", user);
 643                         break;
 644
 645                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 646                          * server name) in standard_sub_basic as it is
 647                          * a feature for logon servers, hence uses the
 648                          * username.  The %p (NIS server path) code is
 649                          * here as it is used instead of the default
 650                          * "path =" string in [homes] and so needs the
 651                          * service name, not the username.  */
 652                 case 'p':
 653                         t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum)));
 654                         break;
 655
 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(smb_name, a_string);
 669         SAFE_FREE(a_string);
 670         return ret_string;
 671 }
 672
 673 /****************************************************************************
 674  Do some standard substitutions in a string.
 675 ****************************************************************************/
 676
 677 void standard_sub_conn(connection_struct *conn, char *str, size_t len)
 678 {
 679         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 680                         conn->gid, current_user_info.smb_name, str, len);
 681 }
 682
 683 char *talloc_sub_conn(TALLOC_CTX *mem_ctx, connection_struct *conn, char *str)
 684 {
 685         return talloc_sub_advanced(mem_ctx, SNUM(conn), conn->user,
 686                         conn->connectpath, conn->gid,
 687                         current_user_info.smb_name, str);
 688 }
 689
 690 char *alloc_sub_conn(connection_struct *conn, char *str)
 691 {
 692         return alloc_sub_advanced(SNUM(conn), conn->user, conn->connectpath,
 693                         conn->gid, current_user_info.smb_name, str);
 694 }
 695
 696 /****************************************************************************
 697  Like standard_sub but by snum.
 698 ****************************************************************************/
 699
 700 void standard_sub_snum(int snum, char *str, size_t len)
 701 {
 702         extern struct current_user current_user;
 703         static uid_t cached_uid = -1;
 704         static fstring cached_user;
 705         /* calling uidtoname() on every substitute would be too expensive, so
 706            we cache the result here as nearly every call is for the same uid */
 707
 708         if (cached_uid != current_user.uid) {
 709                 fstrcpy(cached_user, uidtoname(current_user.uid));
 710                 cached_uid = current_user.uid;
 711         }
 712
 713         standard_sub_advanced(snum, cached_user, "", -1,
 714                 current_user_info.smb_name, str, len);
 715 }