source3/libsmb/smb_share_modes.c

   1 /*
   2    Samba share mode database library external interface library.
   3    Used by non-Samba products needing access to the Samba share mode db.
   4
   5    Copyright (C) Jeremy Allison 2005 - 2006
   6
   7    sharemodes_procid functions (C) Copyright (C) Volker Lendecke 2005
   8
   9      ** NOTE! The following LGPL license applies to this module only.
  10      ** This does NOT imply that all of Samba is released
  11      ** under the LGPL
  12
  13    This library is free software; you can redistribute it and/or
  14    modify it under the terms of the GNU Lesser General Public
  15    License as published by the Free Software Foundation; either
  16    version 3 of the License, or (at your option) any later version.
  17
  18    This library is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21    Lesser General Public License for more details.
  22
  23    You should have received a copy of the GNU Lesser General Public
  24    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  25 */
  26
  27 #include "includes.h"
  28 #include "system/filesys.h"
  29 #include "smb_share_modes.h"
  30 #include "tdb_compat.h"
  31 #include <ccan/hash/hash.h>
  32
  33 /* Database context handle. */
  34 struct smbdb_ctx {
  35         TDB_CONTEXT *smb_tdb;
  36 };
  37
  38 /* Remove the paranoid malloc checker. */
  39 #ifdef malloc
  40 #undef malloc
  41 #endif
  42
  43 int smb_create_share_mode_entry_ex(struct smbdb_ctx *db_ctx, uint64_t dev,
  44                                 uint64_t ino, uint64_t extid,
  45                                 const struct smb_share_mode_entry *new_entry,
  46                                 const char *sharepath, const char *filename);
  47
  48 static bool sharemodes_procid_equal(const struct server_id *p1, const struct server_id *p2)
  49 {
  50         return (p1->pid == p2->pid);
  51 }
  52
  53 static pid_t sharemodes_procid_to_pid(const struct server_id *proc)
  54 {
  55         return proc->pid;
  56 }
  57
  58 /*
  59  * open/close sharemode database.
  60  */
  61
  62 struct smbdb_ctx *smb_share_mode_db_open(const char *db_path)
  63 {
  64         struct smbdb_ctx *smb_db = (struct smbdb_ctx *)malloc(sizeof(struct smbdb_ctx));
  65
  66         if (!smb_db) {
  67                 return NULL;
  68         }
  69
  70         memset(smb_db, '\0', sizeof(struct smbdb_ctx));
  71
  72         /* FIXME: We should *never* open a tdb without logging! */
  73         smb_db->smb_tdb = tdb_open_compat(db_path,
  74                                           0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
  75                                           O_RDWR|O_CREAT,
  76                                           0644,
  77                                           NULL, NULL);
  78
  79         if (!smb_db->smb_tdb) {
  80                 free(smb_db);
  81                 return NULL;
  82         }
  83
  84         /* Should check that this is the correct version.... */
  85         return smb_db;
  86 }
  87
  88 /* key and data records in the tdb locking database */
  89 struct locking_key {
  90         SMB_DEV_T dev;
  91         SMB_INO_T inode;
  92         uint64_t extid;
  93 };
  94
  95 int smb_share_mode_db_close(struct smbdb_ctx *db_ctx)
  96 {
  97         int ret = tdb_close(db_ctx->smb_tdb);
  98         free(db_ctx);
  99         return ret;
 100 }
 101
 102 static TDB_DATA get_locking_key(struct locking_key *lk, uint64_t dev,
 103                                 uint64_t ino, uint64_t extid)
 104 {
 105         TDB_DATA ld;
 106
 107         memset(lk, '\0', sizeof(*lk));
 108         lk->dev = (SMB_DEV_T)dev;
 109         lk->inode = (SMB_INO_T)ino;
 110         lk->extid = extid;
 111         ld.dptr = (uint8 *)lk;
 112         ld.dsize = sizeof(*lk);
 113         return ld;
 114 }
 115
 116 /*
 117  * lock/unlock entry in sharemode database.
 118  */
 119
 120 int smb_lock_share_mode_entry(struct smbdb_ctx *db_ctx,
 121                                 uint64_t dev,
 122                                 uint64_t ino,
 123                                 uint64_t extid)
 124 {
 125         struct locking_key lk;
 126         return tdb_chainlock(db_ctx->smb_tdb, get_locking_key(&lk, dev, ino,
 127                                                               extid)) == 0 ? 0 : -1;
 128 }
 129
 130 int smb_unlock_share_mode_entry(struct smbdb_ctx *db_ctx,
 131                                 uint64_t dev,
 132                                 uint64_t ino,
 133                                 uint64_t extid)
 134 {
 135         struct locking_key lk;
 136         tdb_chainunlock(db_ctx->smb_tdb,
 137                         get_locking_key(&lk, dev, ino, extid));
 138         return 0;
 139 }
 140
 141 /*
 142  * Check if an external smb_share_mode_entry and an internal share_mode entry match.
 143  */
 144
 145 static int share_mode_entry_equal(const struct smb_share_mode_entry *e_entry,
 146                                 const struct share_mode_entry *entry)
 147 {
 148         return (sharemodes_procid_equal(&e_entry->pid, &entry->pid) &&
 149                 e_entry->file_id == (uint32_t)entry->share_file_id &&
 150                 e_entry->open_time.tv_sec == entry->time.tv_sec &&
 151                 e_entry->open_time.tv_usec == entry->time.tv_usec &&
 152                 e_entry->share_access == (uint32_t)entry->share_access &&
 153                 e_entry->access_mask == (uint32_t)entry->access_mask &&
 154                 e_entry->dev == entry->id.devid &&
 155                 e_entry->ino == entry->id.inode &&
 156                 e_entry->extid == entry->id.extid);
 157 }
 158
 159 /*
 160  * Create an internal Samba share_mode entry from an external smb_share_mode_entry.
 161  */
 162
 163 static void create_share_mode_entry(struct share_mode_entry *out,
 164                                 const struct smb_share_mode_entry *in,
 165                                 uint32_t name_hash)
 166 {
 167         memset(out, '\0', sizeof(struct share_mode_entry));
 168
 169         out->pid = in->pid;
 170         out->share_file_id = (unsigned long)in->file_id;
 171         out->time.tv_sec = in->open_time.tv_sec;
 172         out->time.tv_usec = in->open_time.tv_usec;
 173         out->share_access = in->share_access;
 174         out->access_mask = in->access_mask;
 175         out->id.devid = in->dev;
 176         out->id.inode = in->ino;
 177         out->id.extid = in->extid;
 178         out->uid = (uint32)geteuid();
 179         out->flags = 0;
 180         out->name_hash = name_hash;
 181 }
 182
 183 /*
 184  * Return the current share mode list for an open file.
 185  * This uses similar (but simplified) logic to locking/locking.c
 186  */
 187
 188 int smb_get_share_mode_entries(struct smbdb_ctx *db_ctx,
 189                                 uint64_t dev,
 190                                 uint64_t ino,
 191                                 uint64_t extid,
 192                                 struct smb_share_mode_entry **pp_list,
 193                                 unsigned char *p_delete_on_close)
 194 {
 195         struct locking_key lk;
 196         TDB_DATA db_data;
 197         struct smb_share_mode_entry *list = NULL;
 198         int num_share_modes = 0;
 199         struct locking_data *ld = NULL; /* internal samba db state. */
 200         struct share_mode_entry *shares = NULL;
 201         size_t i;
 202         int list_num;
 203
 204         *pp_list = NULL;
 205         *p_delete_on_close = 0;
 206
 207         db_data = tdb_fetch_compat(db_ctx->smb_tdb,
 208                                    get_locking_key(&lk, dev, ino, extid));
 209         if (!db_data.dptr) {
 210                 return 0;
 211         }
 212
 213         ld = (struct locking_data *)db_data.dptr;
 214         num_share_modes = ld->u.s.num_share_mode_entries;
 215
 216         if (!num_share_modes) {
 217                 free(db_data.dptr);
 218                 return 0;
 219         }
 220
 221         list = (struct smb_share_mode_entry *)malloc(sizeof(struct smb_share_mode_entry)*num_share_modes);
 222         if (!list) {
 223                 free(db_data.dptr);
 224                 return -1;
 225         }
 226
 227         memset(list, '\0', num_share_modes * sizeof(struct smb_share_mode_entry));
 228
 229         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
 230
 231         list_num = 0;
 232         for (i = 0; i < num_share_modes; i++) {
 233                 struct share_mode_entry *share = &shares[i];
 234                 struct smb_share_mode_entry *sme = &list[list_num];
 235                 struct server_id pid = share->pid;
 236
 237                 /* Check this process really exists. */
 238                 if (kill(sharemodes_procid_to_pid(&pid), 0) == -1 && (errno == ESRCH)) {
 239                         continue; /* No longer exists. */
 240                 }
 241
 242                 /* Ignore deferred open entries. */
 243                 if (share->op_type == DEFERRED_OPEN_ENTRY) {
 244                         continue;
 245                 }
 246
 247                 /* Copy into the external list. */
 248                 sme->dev = share->id.devid;
 249                 sme->ino = share->id.inode;
 250                 sme->extid = share->id.extid;
 251                 sme->share_access = (uint32_t)share->share_access;
 252                 sme->access_mask = (uint32_t)share->access_mask;
 253                 sme->open_time.tv_sec = share->time.tv_sec;
 254                 sme->open_time.tv_usec = share->time.tv_usec;
 255                 sme->file_id = (uint32_t)share->share_file_id;
 256                 sme->pid = share->pid;
 257                 list_num++;
 258         }
 259
 260         if (list_num == 0) {
 261                 free(db_data.dptr);
 262                 free(list);
 263                 return 0;
 264         }
 265
 266         *p_delete_on_close = ld->u.s.num_delete_token_entries != 0;
 267         *pp_list = list;
 268         free(db_data.dptr);
 269         return list_num;
 270 }
 271
 272 static uint32_t smb_name_hash(const char *sharepath, const char *filename, int *err)
 273 {
 274         char *fullpath = NULL;
 275         size_t sharepath_size = strlen(sharepath);
 276         size_t filename_size = strlen(filename);
 277         uint32_t name_hash;
 278
 279         *err = 0;
 280         fullpath = (char *)malloc(sharepath_size + filename_size + 2);
 281         if (fullpath == NULL) {
 282                 *err = 1;
 283                 return 0;
 284         }
 285         memcpy(fullpath, sharepath, sharepath_size);
 286         fullpath[sharepath_size] = '/';
 287         memcpy(&fullpath[sharepath_size + 1], filename, filename_size + 1);
 288
 289         name_hash = hash(fullpath, strlen(fullpath) + 1, 0);
 290         free(fullpath);
 291         return name_hash;
 292 }
 293
 294 /*
 295  * Create an entry in the Samba share mode db.
 296  */
 297
 298 int smb_create_share_mode_entry_ex(struct smbdb_ctx *db_ctx,
 299                                 uint64_t dev,
 300                                 uint64_t ino,
 301                                 uint64_t extid,
 302                                 const struct smb_share_mode_entry *new_entry,
 303                                 const char *sharepath, /* Must be absolute utf8 path. */
 304                                 const char *filename) /* Must be relative utf8 path. */
 305 {
 306         TDB_DATA db_data;
 307         struct locking_key lk;
 308         TDB_DATA locking_key =  get_locking_key(&lk, dev, ino, extid);
 309         int orig_num_share_modes = 0;
 310         struct locking_data *ld = NULL; /* internal samba db state. */
 311         struct share_mode_entry *shares = NULL;
 312         uint8 *new_data_p = NULL;
 313         size_t new_data_size = 0;
 314         int err = 0;
 315         uint32_t name_hash = smb_name_hash(sharepath, filename, &err);
 316
 317         if (err) {
 318                 return -1;
 319         }
 320
 321         db_data = tdb_fetch_compat(db_ctx->smb_tdb, locking_key);
 322         if (!db_data.dptr) {
 323                 /* We must create the entry. */
 324                 db_data.dptr = (uint8 *)malloc(
 325                         sizeof(struct locking_data) +
 326                         sizeof(struct share_mode_entry) +
 327                         strlen(sharepath) + 1 +
 328                         strlen(filename) + 1);
 329                 if (!db_data.dptr) {
 330                         return -1;
 331                 }
 332                 ld = (struct locking_data *)db_data.dptr;
 333                 memset(ld, '\0', sizeof(struct locking_data));
 334                 ld->u.s.num_share_mode_entries = 1;
 335                 ld->u.s.num_delete_token_entries = 0;
 336                 shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
 337                 create_share_mode_entry(shares, new_entry, name_hash);
 338
 339                 memcpy(db_data.dptr + sizeof(struct locking_data) + sizeof(struct share_mode_entry),
 340                         sharepath,
 341                         strlen(sharepath) + 1);
 342                 memcpy(db_data.dptr + sizeof(struct locking_data) + sizeof(struct share_mode_entry) +
 343                         strlen(sharepath) + 1,
 344                         filename,
 345                         strlen(filename) + 1);
 346
 347                 db_data.dsize = sizeof(struct locking_data) + sizeof(struct share_mode_entry) +
 348                                         strlen(sharepath) + 1 +
 349                                         strlen(filename) + 1;
 350                 if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_INSERT) != 0) {
 351                         free(db_data.dptr);
 352                         return -1;
 353                 }
 354                 free(db_data.dptr);
 355                 return 0;
 356         }
 357
 358         /* Entry exists, we must add a new entry. */
 359         new_data_p = (uint8 *)malloc(
 360                 db_data.dsize + sizeof(struct share_mode_entry));
 361         if (!new_data_p) {
 362                 free(db_data.dptr);
 363                 return -1;
 364         }
 365
 366         ld = (struct locking_data *)db_data.dptr;
 367         orig_num_share_modes = ld->u.s.num_share_mode_entries;
 368
 369         /* Copy the original data. */
 370         memcpy(new_data_p, db_data.dptr, sizeof(struct locking_data) + (orig_num_share_modes * sizeof(struct share_mode_entry)));
 371
 372         /* Add in the new share mode */
 373         shares = (struct share_mode_entry *)(new_data_p + sizeof(struct locking_data) +
 374                         (orig_num_share_modes * sizeof(struct share_mode_entry)));
 375
 376         create_share_mode_entry(shares, new_entry, name_hash);
 377
 378         ld = (struct locking_data *)new_data_p;
 379         ld->u.s.num_share_mode_entries++;
 380
 381         /* Append the original delete_tokens and filenames. */
 382         memcpy(new_data_p + sizeof(struct locking_data) + (ld->u.s.num_share_mode_entries * sizeof(struct share_mode_entry)),
 383                 db_data.dptr + sizeof(struct locking_data) + (orig_num_share_modes * sizeof(struct share_mode_entry)),
 384                 db_data.dsize - sizeof(struct locking_data) - (orig_num_share_modes * sizeof(struct share_mode_entry)));
 385
 386         new_data_size = db_data.dsize + sizeof(struct share_mode_entry);
 387
 388         free(db_data.dptr);
 389
 390         db_data.dptr = new_data_p;
 391         db_data.dsize = new_data_size;
 392
 393         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) != 0) {
 394                 free(db_data.dptr);
 395                 return -1;
 396         }
 397         free(db_data.dptr);
 398         return 0;
 399 }
 400
 401 /*
 402  * Create an entry in the Samba share mode db. Original interface - doesn't
 403  * Distinguish between share path and filename. Fudge this by using a
 404  * sharepath of / and a relative filename of (filename+1).
 405  */
 406
 407 int smb_create_share_mode_entry(struct smbdb_ctx *db_ctx,
 408                                 uint64_t dev,
 409                                 uint64_t ino,
 410                                 uint64_t extid,
 411                                 const struct smb_share_mode_entry *new_entry,
 412                                 const char *filename) /* Must be absolute utf8 path. */
 413 {
 414         if (*filename != '/') {
 415                 abort();
 416         }
 417         return smb_create_share_mode_entry_ex(db_ctx, dev, ino, extid, new_entry,
 418                                                 "/", &filename[1]);
 419 }
 420
 421 int smb_delete_share_mode_entry(struct smbdb_ctx *db_ctx,
 422                                 uint64_t dev,
 423                                 uint64_t ino,
 424                                 uint64_t extid,
 425                                 const struct smb_share_mode_entry *del_entry)
 426 {
 427         TDB_DATA db_data;
 428         struct locking_key lk;
 429         TDB_DATA locking_key =  get_locking_key(&lk, dev, ino, extid);
 430         int orig_num_share_modes = 0;
 431         struct locking_data *ld = NULL; /* internal samba db state. */
 432         struct share_mode_entry *shares = NULL;
 433         uint8 *new_data_p = NULL;
 434         size_t remaining_size = 0;
 435         size_t i, num_share_modes;
 436         const uint8 *remaining_ptr = NULL;
 437
 438         db_data = tdb_fetch_compat(db_ctx->smb_tdb, locking_key);
 439         if (!db_data.dptr) {
 440                 return -1; /* Error - missing entry ! */
 441         }
 442
 443         ld = (struct locking_data *)db_data.dptr;
 444         orig_num_share_modes = ld->u.s.num_share_mode_entries;
 445         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
 446
 447         if (orig_num_share_modes == 1) {
 448                 /* Only one entry - better be ours... */
 449                 if (!share_mode_entry_equal(del_entry, shares)) {
 450                         /* Error ! We can't delete someone else's entry ! */
 451                         free(db_data.dptr);
 452                         return -1;
 453                 }
 454                 /* It's ours - just remove the entire record. */
 455                 free(db_data.dptr);
 456                 return tdb_delete(db_ctx->smb_tdb, locking_key) ? -1 : 0;
 457         }
 458
 459         /* More than one - allocate a new record minus the one we'll delete. */
 460         new_data_p = (uint8 *)malloc(
 461                 db_data.dsize - sizeof(struct share_mode_entry));
 462         if (!new_data_p) {
 463                 free(db_data.dptr);
 464                 return -1;
 465         }
 466
 467         /* Copy the header. */
 468         memcpy(new_data_p, db_data.dptr, sizeof(struct locking_data));
 469
 470         num_share_modes = 0;
 471         for (i = 0; i < orig_num_share_modes; i++) {
 472                 struct share_mode_entry *share = &shares[i];
 473                 struct server_id pid = share->pid;
 474
 475                 /* Check this process really exists. */
 476                 if (kill(sharemodes_procid_to_pid(&pid), 0) == -1 && (errno == ESRCH)) {
 477                         continue; /* No longer exists. */
 478                 }
 479
 480                 if (share_mode_entry_equal(del_entry, share)) {
 481                         continue; /* This is our delete taget. */
 482                 }
 483
 484                 memcpy(new_data_p + sizeof(struct locking_data) +
 485                                 (num_share_modes * sizeof(struct share_mode_entry)),
 486                         share, sizeof(struct share_mode_entry) );
 487
 488                 num_share_modes++;
 489         }
 490
 491         if (num_share_modes == 0) {
 492                 /* None left after pruning. Delete record. */
 493                 free(db_data.dptr);
 494                 free(new_data_p);
 495                 return tdb_delete(db_ctx->smb_tdb, locking_key) ? -1 : 0;
 496         }
 497
 498         /* Copy any delete tokens plus the terminating filenames. */
 499         remaining_ptr = db_data.dptr + sizeof(struct locking_data) + (orig_num_share_modes * sizeof(struct share_mode_entry));
 500         remaining_size = db_data.dsize - (remaining_ptr - db_data.dptr);
 501
 502         memcpy(new_data_p + sizeof(struct locking_data) + (num_share_modes * sizeof(struct share_mode_entry)),
 503                 remaining_ptr,
 504                 remaining_size);
 505
 506         free(db_data.dptr);
 507
 508         db_data.dptr = new_data_p;
 509
 510         /* Re-save smaller record. */
 511         ld = (struct locking_data *)db_data.dptr;
 512         ld->u.s.num_share_mode_entries = num_share_modes;
 513
 514         db_data.dsize = sizeof(struct locking_data) + (num_share_modes * sizeof(struct share_mode_entry)) + remaining_size;
 515
 516         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) != 0) {
 517                 free(db_data.dptr);
 518                 return -1;
 519         }
 520         free(db_data.dptr);
 521         return 0;
 522 }
 523
 524 int smb_change_share_mode_entry(struct smbdb_ctx *db_ctx,
 525                                 uint64_t dev,
 526                                 uint64_t ino,
 527                                 uint64_t extid,
 528                                 const struct smb_share_mode_entry *set_entry,
 529                                 const struct smb_share_mode_entry *new_entry)
 530 {
 531         TDB_DATA db_data;
 532         struct locking_key lk;
 533         TDB_DATA locking_key =  get_locking_key(&lk, dev, ino, extid);
 534         int num_share_modes = 0;
 535         struct locking_data *ld = NULL; /* internal samba db state. */
 536         struct share_mode_entry *shares = NULL;
 537         size_t i;
 538         int found_entry = 0;
 539
 540         db_data = tdb_fetch_compat(db_ctx->smb_tdb, locking_key);
 541         if (!db_data.dptr) {
 542                 return -1; /* Error - missing entry ! */
 543         }
 544
 545         ld = (struct locking_data *)db_data.dptr;
 546         num_share_modes = ld->u.s.num_share_mode_entries;
 547         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
 548
 549         for (i = 0; i < num_share_modes; i++) {
 550                 struct share_mode_entry *share = &shares[i];
 551                 struct server_id pid = share->pid;
 552
 553                 /* Check this process really exists. */
 554                 if (kill(sharemodes_procid_to_pid(&pid), 0) == -1 && (errno == ESRCH)) {
 555                         continue; /* No longer exists. */
 556                 }
 557
 558                 if (share_mode_entry_equal(set_entry, share)) {
 559                         create_share_mode_entry(share, new_entry, share->name_hash);
 560                         found_entry = 1;
 561                         break;
 562                 }
 563         }
 564
 565         if (!found_entry) {
 566                 free(db_data.dptr);
 567                 return -1;
 568         }
 569
 570         /* Save modified data. */
 571         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) != 0) {
 572                 free(db_data.dptr);
 573                 return -1;
 574         }
 575         free(db_data.dptr);
 576         return 0;
 577 }