source/utils/sharesec.c

   1 /*
   2  *  Unix SMB/Netbios implementation.
   3  *  Utility for managing share permissions
   4  *
   5  *  Copyright (C) Tim Potter                    2000
   6  *  Copyright (C) Jeremy Allison                2000
   7  *  Copyright (C) Jelmer Vernooij               2003
   8  *  Copyright (C) Gerald (Jerry) Carter         2005.
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 3 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24
  25 #include "includes.h"
  26
  27 static TALLOC_CTX *ctx;
  28
  29 enum acl_mode {SMB_ACL_DELETE, SMB_ACL_MODIFY, SMB_ACL_ADD, SMB_ACL_SET, SMB_ACL_VIEW };
  30
  31 struct perm_value {
  32         const char *perm;
  33         uint32 mask;
  34 };
  35
  36 /* These values discovered by inspection */
  37
  38 static const struct perm_value special_values[] = {
  39         { "R", SEC_RIGHTS_FILE_READ },
  40         { "W", SEC_RIGHTS_FILE_WRITE },
  41         { "X", SEC_RIGHTS_FILE_EXECUTE },
  42         { "D", SEC_STD_DELETE },
  43         { "P", SEC_STD_WRITE_DAC },
  44         { "O", SEC_STD_WRITE_OWNER },
  45         { NULL, 0 },
  46 };
  47
  48 #define SEC_RIGHTS_DIR_CHANGE ( SEC_RIGHTS_DIR_READ|SEC_STD_DELETE|SEC_RIGHTS_DIR_WRITE|SEC_DIR_TRAVERSE )
  49
  50 static const struct perm_value standard_values[] = {
  51         { "READ",   SEC_RIGHTS_DIR_READ|SEC_DIR_TRAVERSE },
  52         { "CHANGE", SEC_RIGHTS_DIR_CHANGE },
  53         { "FULL",   SEC_RIGHTS_DIR_ALL },
  54         { NULL, 0 },
  55 };
  56
  57 /********************************************************************
  58  print an ACE on a FILE
  59 ********************************************************************/
  60
  61 static void print_ace(FILE *f, SEC_ACE *ace)
  62 {
  63         const struct perm_value *v;
  64         int do_print = 0;
  65         uint32 got_mask;
  66
  67         fprintf(f, "%s:", sid_string_tos(&ace->trustee));
  68
  69         /* Ace type */
  70
  71         if (ace->type == SEC_ACE_TYPE_ACCESS_ALLOWED) {
  72                 fprintf(f, "ALLOWED");
  73         } else if (ace->type == SEC_ACE_TYPE_ACCESS_DENIED) {
  74                 fprintf(f, "DENIED");
  75         } else {
  76                 fprintf(f, "%d", ace->type);
  77         }
  78
  79         /* Not sure what flags can be set in a file ACL */
  80
  81         fprintf(f, "/%d/", ace->flags);
  82
  83         /* Standard permissions */
  84
  85         for (v = standard_values; v->perm; v++) {
  86                 if (ace->access_mask == v->mask) {
  87                         fprintf(f, "%s", v->perm);
  88                         return;
  89                 }
  90         }
  91
  92         /* Special permissions.  Print out a hex value if we have
  93            leftover bits in the mask. */
  94
  95         got_mask = ace->access_mask;
  96
  97  again:
  98         for (v = special_values; v->perm; v++) {
  99                 if ((ace->access_mask & v->mask) == v->mask) {
 100                         if (do_print) {
 101                                 fprintf(f, "%s", v->perm);
 102                         }
 103                         got_mask &= ~v->mask;
 104                 }
 105         }
 106
 107         if (!do_print) {
 108                 if (got_mask != 0) {
 109                         fprintf(f, "0x%08x", ace->access_mask);
 110                 } else {
 111                         do_print = 1;
 112                         goto again;
 113                 }
 114         }
 115 }
 116
 117 /********************************************************************
 118  print a ascii version of a security descriptor on a FILE handle
 119 ********************************************************************/
 120
 121 static void sec_desc_print(FILE *f, SEC_DESC *sd)
 122 {
 123         uint32 i;
 124
 125         fprintf(f, "REVISION:%d\n", sd->revision);
 126
 127         /* Print owner and group sid */
 128
 129         fprintf(f, "OWNER:%s\n", sid_string_tos(sd->owner_sid));
 130
 131         fprintf(f, "GROUP:%s\n", sid_string_tos(sd->group_sid));
 132
 133         /* Print aces */
 134         for (i = 0; sd->dacl && i < sd->dacl->num_aces; i++) {
 135                 SEC_ACE *ace = &sd->dacl->aces[i];
 136                 fprintf(f, "ACL:");
 137                 print_ace(f, ace);
 138                 fprintf(f, "\n");
 139         }
 140
 141 }
 142
 143 /********************************************************************
 144     parse an ACE in the same format as print_ace()
 145 ********************************************************************/
 146
 147 static bool parse_ace(SEC_ACE *ace, const char *orig_str)
 148 {
 149         char *p;
 150         const char *cp;
 151         char *tok;
 152         unsigned int atype = 0;
 153         unsigned int aflags = 0;
 154         unsigned int amask = 0;
 155         DOM_SID sid;
 156         uint32_t mask;
 157         const struct perm_value *v;
 158         char *str = SMB_STRDUP(orig_str);
 159         TALLOC_CTX *frame = talloc_stackframe();
 160
 161         if (!str) {
 162                 TALLOC_FREE(frame);
 163                 return False;
 164         }
 165
 166         ZERO_STRUCTP(ace);
 167         p = strchr_m(str,':');
 168         if (!p) {
 169                 printf("ACE '%s': missing ':'.\n", orig_str);
 170                 SAFE_FREE(str);
 171                 TALLOC_FREE(frame);
 172                 return False;
 173         }
 174         *p = '\0';
 175         p++;
 176         /* Try to parse numeric form */
 177
 178         if (sscanf(p, "%i/%i/%i", &atype, &aflags, &amask) == 3 &&
 179             string_to_sid(&sid, str)) {
 180                 goto done;
 181         }
 182
 183         /* Try to parse text form */
 184
 185         if (!string_to_sid(&sid, str)) {
 186                 printf("ACE '%s': failed to convert '%s' to SID\n",
 187                         orig_str, str);
 188                 SAFE_FREE(str);
 189                 TALLOC_FREE(frame);
 190                 return False;
 191         }
 192
 193         cp = p;
 194         if (!next_token_talloc(frame, &cp, &tok, "/")) {
 195                 printf("ACE '%s': failed to find '/' character.\n",
 196                         orig_str);
 197                 SAFE_FREE(str);
 198                 TALLOC_FREE(frame);
 199                 return False;
 200         }
 201
 202         if (strncmp(tok, "ALLOWED", strlen("ALLOWED")) == 0) {
 203                 atype = SEC_ACE_TYPE_ACCESS_ALLOWED;
 204         } else if (strncmp(tok, "DENIED", strlen("DENIED")) == 0) {
 205                 atype = SEC_ACE_TYPE_ACCESS_DENIED;
 206         } else {
 207                 printf("ACE '%s': missing 'ALLOWED' or 'DENIED' entry at '%s'\n",
 208                         orig_str, tok);
 209                 SAFE_FREE(str);
 210                 TALLOC_FREE(frame);
 211                 return False;
 212         }
 213
 214         /* Only numeric form accepted for flags at present */
 215         /* no flags on share permissions */
 216
 217         if (!(next_token_talloc(frame, &cp, &tok, "/") &&
 218               sscanf(tok, "%i", &aflags) && aflags == 0)) {
 219                 printf("ACE '%s': bad integer flags entry at '%s'\n",
 220                         orig_str, tok);
 221                 SAFE_FREE(str);
 222                 TALLOC_FREE(frame);
 223                 return False;
 224         }
 225
 226         if (!next_token_talloc(frame, &cp, &tok, "/")) {
 227                 printf("ACE '%s': missing / at '%s'\n",
 228                         orig_str, tok);
 229                 SAFE_FREE(str);
 230                 TALLOC_FREE(frame);
 231                 return False;
 232         }
 233
 234         if (strncmp(tok, "0x", 2) == 0) {
 235                 if (sscanf(tok, "%i", &amask) != 1) {
 236                         printf("ACE '%s': bad hex number at '%s'\n",
 237                                 orig_str, tok);
 238                         TALLOC_FREE(frame);
 239                         SAFE_FREE(str);
 240                         return False;
 241                 }
 242                 goto done;
 243         }
 244
 245         for (v = standard_values; v->perm; v++) {
 246                 if (strcmp(tok, v->perm) == 0) {
 247                         amask = v->mask;
 248                         goto done;
 249                 }
 250         }
 251
 252         p = tok;
 253
 254         while(*p) {
 255                 bool found = False;
 256
 257                 for (v = special_values; v->perm; v++) {
 258                         if (v->perm[0] == *p) {
 259                                 amask |= v->mask;
 260                                 found = True;
 261                         }
 262                 }
 263
 264                 if (!found) {
 265                         printf("ACE '%s': bad permission value at '%s'\n",
 266                                 orig_str, p);
 267                         TALLOC_FREE(frame);
 268                         SAFE_FREE(str);
 269                         return False;
 270                 }
 271                 p++;
 272         }
 273
 274         if (*p) {
 275                 TALLOC_FREE(frame);
 276                 SAFE_FREE(str);
 277                 return False;
 278         }
 279
 280  done:
 281         mask = amask;
 282         init_sec_ace(ace, &sid, atype, mask, aflags);
 283         SAFE_FREE(str);
 284         TALLOC_FREE(frame);
 285         return True;
 286 }
 287
 288
 289 /********************************************************************
 290 ********************************************************************/
 291
 292 static SEC_DESC* parse_acl_string(TALLOC_CTX *mem_ctx, const char *szACL, size_t *sd_size )
 293 {
 294         SEC_DESC *sd = NULL;
 295         SEC_ACE *ace;
 296         SEC_ACL *theacl;
 297         int num_ace;
 298         const char *pacl;
 299         int i;
 300
 301         if ( !szACL )
 302                 return NULL;
 303
 304         pacl = szACL;
 305         num_ace = count_chars( pacl, ',' ) + 1;
 306
 307         if ( !(ace = TALLOC_ZERO_ARRAY( mem_ctx, SEC_ACE, num_ace )) )
 308                 return NULL;
 309
 310         for ( i=0; i<num_ace; i++ ) {
 311                 char *end_acl = strchr_m( pacl, ',' );
 312                 fstring acl_string;
 313
 314                 strncpy( acl_string, pacl, MIN( PTR_DIFF( end_acl, pacl ), sizeof(fstring)-1) );
 315                 acl_string[MIN( PTR_DIFF( end_acl, pacl ), sizeof(fstring)-1)] = '\0';
 316
 317                 if ( !parse_ace( &ace[i], acl_string ) )
 318                         return NULL;
 319
 320                 pacl = end_acl;
 321                 pacl++;
 322         }
 323
 324         if ( !(theacl = make_sec_acl( mem_ctx, NT4_ACL_REVISION, num_ace, ace )) )
 325                 return NULL;
 326
 327         sd = make_sec_desc( mem_ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE,
 328                 NULL, NULL, NULL, theacl, sd_size);
 329
 330         return sd;
 331 }
 332
 333 /* add an ACE to a list of ACEs in a SEC_ACL */
 334 static bool add_ace(TALLOC_CTX *mem_ctx, SEC_ACL **the_acl, SEC_ACE *ace)
 335 {
 336         SEC_ACL *new_ace;
 337         SEC_ACE *aces;
 338         if (! *the_acl) {
 339                 return (((*the_acl) = make_sec_acl(mem_ctx, 3, 1, ace)) != NULL);
 340         }
 341
 342         if (!(aces = SMB_CALLOC_ARRAY(SEC_ACE, 1+(*the_acl)->num_aces))) {
 343                 return False;
 344         }
 345         memcpy(aces, (*the_acl)->aces, (*the_acl)->num_aces * sizeof(SEC_ACE));
 346         memcpy(aces+(*the_acl)->num_aces, ace, sizeof(SEC_ACE));
 347         new_ace = make_sec_acl(mem_ctx,(*the_acl)->revision,1+(*the_acl)->num_aces, aces);
 348         SAFE_FREE(aces);
 349         (*the_acl) = new_ace;
 350         return True;
 351 }
 352
 353 /* The MSDN is contradictory over the ordering of ACE entries in an ACL.
 354    However NT4 gives a "The information may have been modified by a
 355    computer running Windows NT 5.0" if denied ACEs do not appear before
 356    allowed ACEs. */
 357
 358 static int ace_compare(SEC_ACE *ace1, SEC_ACE *ace2)
 359 {
 360         if (sec_ace_equal(ace1, ace2))
 361                 return 0;
 362
 363         if (ace1->type != ace2->type)
 364                 return ace2->type - ace1->type;
 365
 366         if (sid_compare(&ace1->trustee, &ace2->trustee))
 367                 return sid_compare(&ace1->trustee, &ace2->trustee);
 368
 369         if (ace1->flags != ace2->flags)
 370                 return ace1->flags - ace2->flags;
 371
 372         if (ace1->access_mask != ace2->access_mask)
 373                 return ace1->access_mask - ace2->access_mask;
 374
 375         if (ace1->size != ace2->size)
 376                 return ace1->size - ace2->size;
 377
 378         return memcmp(ace1, ace2, sizeof(SEC_ACE));
 379 }
 380
 381 static void sort_acl(SEC_ACL *the_acl)
 382 {
 383         uint32 i;
 384         if (!the_acl) return;
 385
 386         qsort(the_acl->aces, the_acl->num_aces, sizeof(the_acl->aces[0]), QSORT_CAST ace_compare);
 387
 388         for (i=1;i<the_acl->num_aces;) {
 389                 if (sec_ace_equal(&the_acl->aces[i-1], &the_acl->aces[i])) {
 390                         int j;
 391                         for (j=i; j<the_acl->num_aces-1; j++) {
 392                                 the_acl->aces[j] = the_acl->aces[j+1];
 393                         }
 394                         the_acl->num_aces--;
 395                 } else {
 396                         i++;
 397                 }
 398         }
 399 }
 400
 401
 402 static int change_share_sec(TALLOC_CTX *mem_ctx, const char *sharename, char *the_acl, enum acl_mode mode)
 403 {
 404         SEC_DESC *sd = NULL;
 405         SEC_DESC *old = NULL;
 406         size_t sd_size = 0;
 407         uint32 i, j;
 408
 409         if (mode != SMB_ACL_SET) {
 410             if (!(old = get_share_security( mem_ctx, sharename, &sd_size )) ) {
 411                 fprintf(stderr, "Unable to retrieve permissions for share [%s]\n", sharename);
 412                 return -1;
 413             }
 414         }
 415
 416         if ( (mode != SMB_ACL_VIEW) && !(sd = parse_acl_string(mem_ctx, the_acl, &sd_size )) ) {
 417                 fprintf( stderr, "Failed to parse acl\n");
 418                 return -1;
 419         }
 420
 421         switch (mode) {
 422         case SMB_ACL_VIEW:
 423                 sec_desc_print( stdout, old);
 424                 return 0;
 425         case SMB_ACL_DELETE:
 426             for (i=0;sd->dacl && i<sd->dacl->num_aces;i++) {
 427                 bool found = False;
 428
 429                 for (j=0;old->dacl && j<old->dacl->num_aces;j++) {
 430                     if (sec_ace_equal(&sd->dacl->aces[i], &old->dacl->aces[j])) {
 431                         uint32 k;
 432                         for (k=j; k<old->dacl->num_aces-1;k++) {
 433                             old->dacl->aces[k] = old->dacl->aces[k+1];
 434                         }
 435                         old->dacl->num_aces--;
 436                         found = True;
 437                         break;
 438                     }
 439                 }
 440
 441                 if (!found) {
 442                 printf("ACL for ACE:");
 443                 print_ace(stdout, &sd->dacl->aces[i]);
 444                 printf(" not found\n");
 445                 }
 446             }
 447
 448             break;
 449         case SMB_ACL_MODIFY:
 450             for (i=0;sd->dacl && i<sd->dacl->num_aces;i++) {
 451                 bool found = False;
 452
 453                 for (j=0;old->dacl && j<old->dacl->num_aces;j++) {
 454                     if (sid_equal(&sd->dacl->aces[i].trustee,
 455                         &old->dacl->aces[j].trustee)) {
 456                         old->dacl->aces[j] = sd->dacl->aces[i];
 457                         found = True;
 458                     }
 459                 }
 460
 461                 if (!found) {
 462                     printf("ACL for SID %s not found\n",
 463                            sid_string_tos(&sd->dacl->aces[i].trustee));
 464                 }
 465             }
 466
 467             if (sd->owner_sid) {
 468                 old->owner_sid = sd->owner_sid;
 469             }
 470
 471             if (sd->group_sid) {
 472                 old->group_sid = sd->group_sid;
 473             }
 474             break;
 475         case SMB_ACL_ADD:
 476             for (i=0;sd->dacl && i<sd->dacl->num_aces;i++) {
 477                 add_ace(mem_ctx, &old->dacl, &sd->dacl->aces[i]);
 478             }
 479             break;
 480         case SMB_ACL_SET:
 481             old = sd;
 482             break;
 483         }
 484
 485         /* Denied ACE entries must come before allowed ones */
 486         sort_acl(old->dacl);
 487
 488         if ( !set_share_security( sharename, old ) ) {
 489             fprintf( stderr, "Failed to store acl for share [%s]\n", sharename );
 490             return 2;
 491         }
 492         return 0;
 493 }
 494
 495 /********************************************************************
 496   main program
 497 ********************************************************************/
 498
 499 int main(int argc, const char *argv[])
 500 {
 501         int opt;
 502         int retval = 0;
 503         enum acl_mode mode = SMB_ACL_SET;
 504         static char *the_acl = NULL;
 505         fstring sharename;
 506         bool force_acl = False;
 507         int snum;
 508         poptContext pc;
 509         bool initialize_sid = False;
 510         struct poptOption long_options[] = {
 511                 POPT_AUTOHELP
 512                 { "remove", 'r', POPT_ARG_STRING, &the_acl, 'r', "Delete an ACE", "ACL" },
 513                 { "modify", 'm', POPT_ARG_STRING, &the_acl, 'm', "Modify an acl", "ACL" },
 514                 { "add", 'a', POPT_ARG_STRING, &the_acl, 'a', "Add an ACE", "ACL" },
 515                 { "replace", 'R', POPT_ARG_STRING, &the_acl, 'R', "Set share mission ACL", "ACLS" },
 516                 { "view", 'v', POPT_ARG_NONE, NULL, 'v', "View current share permissions" },
 517                 { "machine-sid", 'M', POPT_ARG_NONE, NULL, 'M', "Initialize the machine SID" },
 518                 { "force", 'F', POPT_ARG_NONE, NULL, 'F', "Force storing the ACL", "ACLS" },
 519                 POPT_COMMON_SAMBA
 520                 { NULL }
 521         };
 522
 523         if ( !(ctx = talloc_stackframe()) ) {
 524                 fprintf( stderr, "Failed to initialize talloc context!\n");
 525                 return -1;
 526         }
 527
 528         /* set default debug level to 1 regardless of what smb.conf sets */
 529         setup_logging( "sharesec", True );
 530         DEBUGLEVEL_CLASS[DBGC_ALL] = 1;
 531         dbf = x_stderr;
 532         x_setbuf( x_stderr, NULL );
 533
 534         pc = poptGetContext("sharesec", argc, argv, long_options, 0);
 535
 536         poptSetOtherOptionHelp(pc, "sharename\n");
 537
 538         while ((opt = poptGetNextOpt(pc)) != -1) {
 539                 switch (opt) {
 540                 case 'r':
 541                         the_acl = smb_xstrdup(poptGetOptArg(pc));
 542                         mode = SMB_ACL_DELETE;
 543                         break;
 544
 545                 case 'm':
 546                         the_acl = smb_xstrdup(poptGetOptArg(pc));
 547                         mode = SMB_ACL_MODIFY;
 548                         break;
 549
 550                 case 'a':
 551                         the_acl = smb_xstrdup(poptGetOptArg(pc));
 552                         mode = SMB_ACL_ADD;
 553                         break;
 554                 case 'R':
 555                         the_acl = smb_xstrdup(poptGetOptArg(pc));
 556                         mode = SMB_ACL_SET;
 557                         break;
 558
 559                 case 'v':
 560                         mode = SMB_ACL_VIEW;
 561                         break;
 562
 563                 case 'F':
 564                         force_acl = True;
 565                         break;
 566
 567                 case 'M':
 568                         initialize_sid = True;
 569                         break;
 570                 }
 571         }
 572
 573         setlinebuf(stdout);
 574
 575         load_case_tables();
 576
 577         lp_load( get_dyn_CONFIGFILE(), False, False, False, True );
 578
 579         /* check for initializing secrets.tdb first */
 580
 581         if ( initialize_sid ) {
 582                 DOM_SID *sid = get_global_sam_sid();
 583
 584                 if ( !sid ) {
 585                         fprintf( stderr, "Failed to retrieve Machine SID!\n");
 586                         return 3;
 587                 }
 588
 589                 printf ("%s\n", sid_string_tos( sid ) );
 590                 return 0;
 591         }
 592
 593         if ( mode == SMB_ACL_VIEW && force_acl ) {
 594                 fprintf( stderr, "Invalid combination of -F and -v\n");
 595                 return -1;
 596         }
 597
 598         /* get the sharename */
 599
 600         if(!poptPeekArg(pc)) {
 601                 poptPrintUsage(pc, stderr, 0);
 602                 return -1;
 603         }
 604
 605         fstrcpy(sharename, poptGetArg(pc));
 606
 607         snum = lp_servicenumber( sharename );
 608
 609         if ( snum == -1 && !force_acl ) {
 610                 fprintf( stderr, "Invalid sharename: %s\n", sharename);
 611                 return -1;
 612         }
 613
 614         retval = change_share_sec(ctx, sharename, the_acl, mode);
 615
 616         talloc_destroy(ctx);
 617
 618         return retval;
 619 }