source/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.
   6
   7    This library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2 of the License, or (at your option) any later version.
  11
  12    This library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with this library; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22 #include "includes.h"
  23 #include "smb_share_modes.h"
  24
  25 /* Remove the paranoid malloc checker. */
  26 #ifdef malloc
  27 #undef malloc
  28 #endif
  29
  30 /*
  31  * open/close sharemode database.
  32  */
  33
  34 struct smbdb_ctx *smb_share_mode_db_open(const char *db_path)
  35 {
  36         struct smbdb_ctx *smb_db = (struct smbdb_ctx *)malloc(sizeof(struct smbdb_ctx));
  37
  38         if (!smb_db) {
  39                 return NULL;
  40         }
  41
  42         memset(smb_db, '\0', sizeof(struct smbdb_ctx));
  43
  44         smb_db->smb_tdb = tdb_open(db_path,
  45                                 0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST,
  46                                 O_RDWR|O_CREAT,
  47                                 0644);
  48
  49         if (!smb_db->smb_tdb) {
  50                 free(smb_db);
  51                 return NULL;
  52         }
  53
  54         /* Should check that this is the correct version.... */
  55         return smb_db;
  56 }
  57
  58 /* key and data records in the tdb locking database */
  59 struct locking_key {
  60         SMB_DEV_T dev;
  61         SMB_INO_T inode;
  62 };
  63
  64 int smb_share_mode_db_close(struct smbdb_ctx *db_ctx)
  65 {
  66         int ret = tdb_close(db_ctx->smb_tdb);
  67         free(db_ctx);
  68         return ret;
  69 }
  70
  71 static TDB_DATA get_locking_key(uint64_t dev, uint64_t ino)
  72 {
  73         static struct locking_key lk;
  74         TDB_DATA ld;
  75
  76         memset(&lk, '\0', sizeof(struct locking_key));
  77         lk.dev = (SMB_DEV_T)dev;
  78         lk.inode = (SMB_INO_T)ino;
  79         ld.dptr = (char *)&lk;
  80         ld.dsize = sizeof(lk);
  81         return ld;
  82 }
  83
  84 /*
  85  * lock/unlock entry in sharemode database.
  86  */
  87
  88 int smb_lock_share_mode_entry(struct smbdb_ctx *db_ctx,
  89                                 uint64_t dev,
  90                                 uint64_t ino)
  91 {
  92         return tdb_chainlock(db_ctx->smb_tdb, get_locking_key(dev, ino));
  93 }
  94
  95 int smb_unlock_share_mode_entry(struct smbdb_ctx *db_ctx,
  96                                 uint64_t dev,
  97                                 uint64_t ino)
  98 {
  99         return tdb_chainunlock(db_ctx->smb_tdb, get_locking_key(dev, ino));
 100 }
 101
 102 /* Internal structure of Samba share mode db. */
 103 /* FIXME ! This should be moved into a Samba include file. */
 104
 105 struct locking_data {
 106         union {
 107                 struct {
 108                         int num_share_mode_entries;
 109                         BOOL delete_on_close;
 110                 } s;
 111                 struct share_mode_entry dummy; /* Needed for alignment. */
 112         } u;
 113         /* the following two entries are implicit
 114            struct share_mode_entry modes[num_share_mode_entries];
 115            char file_name[];
 116         */
 117 };
 118
 119 /*
 120  * Check if an external smb_share_mode_entry and an internal share_mode entry match.
 121  */
 122
 123 static int share_mode_entry_equal(const struct smb_share_mode_entry *e_entry, const struct share_mode_entry *entry)
 124 {
 125         return (e_entry->pid == entry->pid &&
 126                 e_entry->file_id == (uint32_t)entry->share_file_id &&
 127                 e_entry->open_time.tv_sec == entry->time.tv_sec &&
 128                 e_entry->open_time.tv_usec == entry->time.tv_usec &&
 129                 e_entry->share_access == (uint32_t)entry->share_access &&
 130                 e_entry->access_mask == (uint32_t)entry->access_mask &&
 131                 e_entry->dev == (uint64_t)entry->dev &&
 132                 e_entry->ino == (uint64_t)entry->inode);
 133 }
 134
 135 /*
 136  * Create an internal Samba share_mode entry from an external smb_share_mode_entry.
 137  */
 138
 139 static void create_share_mode_entry(struct share_mode_entry *out, const struct smb_share_mode_entry *in)
 140 {
 141         memset(out, '\0', sizeof(struct share_mode_entry));
 142
 143         out->pid = in->pid;
 144         out->share_file_id = (unsigned long)in->file_id;
 145         out->time.tv_sec = in->open_time.tv_sec;
 146         out->time.tv_usec = in->open_time.tv_usec;
 147         out->share_access = in->share_access;
 148         out->access_mask = in->access_mask;
 149         out->dev = (SMB_DEV_T)in->dev;
 150         out->inode = (SMB_INO_T)in->ino;
 151 }
 152
 153 /*
 154  * Return the current share mode list for an open file.
 155  * This uses similar (but simplified) logic to locking/locking.c
 156  */
 157
 158 int smb_get_share_mode_entries(struct smbdb_ctx *db_ctx,
 159                                 uint64_t dev,
 160                                 uint64_t ino,
 161                                 struct smb_share_mode_entry **pp_list,
 162                                 unsigned char *p_delete_on_close)
 163 {
 164         TDB_DATA db_data;
 165         struct smb_share_mode_entry *list = NULL;
 166         int num_share_modes = 0;
 167         struct locking_data *ld = NULL; /* internal samba db state. */
 168         struct share_mode_entry *shares = NULL;
 169         size_t i;
 170         int list_num;
 171
 172         *pp_list = NULL;
 173         *p_delete_on_close = 0;
 174
 175         db_data = tdb_fetch(db_ctx->smb_tdb, get_locking_key(dev, ino));
 176         if (!db_data.dptr) {
 177                 return 0;
 178         }
 179
 180         ld = (struct locking_data *)db_data.dptr;
 181         num_share_modes = ld->u.s.num_share_mode_entries;
 182
 183         if (!num_share_modes) {
 184                 free(db_data.dptr);
 185                 return 0;
 186         }
 187
 188         list = (struct smb_share_mode_entry *)malloc(sizeof(struct smb_share_mode_entry)*num_share_modes);
 189         if (!list) {
 190                 free(db_data.dptr);
 191                 return -1;
 192         }
 193
 194         memset(list, '\0', num_share_modes * sizeof(struct smb_share_mode_entry));
 195
 196         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct share_mode_entry));
 197
 198         list_num = 0;
 199         for (i = 0; i < num_share_modes; i++) {
 200                 struct share_mode_entry *share = &shares[i];
 201                 struct smb_share_mode_entry *sme = &list[list_num];
 202                 pid_t pid = share->pid;
 203
 204                 /* Check this process really exists. */
 205                 if (kill(pid, 0) == -1 && (errno == ESRCH)) {
 206                         continue; /* No longer exists. */
 207                 }
 208
 209                 /* Copy into the external list. */
 210                 sme->dev = (uint64_t)share->dev;
 211                 sme->ino = (uint64_t)share->inode;
 212                 sme->share_access = (uint32_t)share->share_access;
 213                 sme->access_mask = (uint32_t)share->access_mask;
 214                 sme->open_time.tv_sec = share->time.tv_sec;
 215                 sme->open_time.tv_usec = share->time.tv_usec;
 216                 sme->file_id = (uint32_t)share->share_file_id;
 217                 sme->pid = share->pid;
 218                 list_num++;
 219         }
 220
 221         if (list_num == 0) {
 222                 free(db_data.dptr);
 223                 free(list);
 224                 return 0;
 225         }
 226
 227         *p_delete_on_close = ld->u.s.delete_on_close;
 228         *pp_list = list;
 229         free(db_data.dptr);
 230         return list_num;
 231 }
 232
 233 /*
 234  * Create an entry in the Samba share mode db.
 235  */
 236
 237 int smb_create_share_mode_entry(struct smbdb_ctx *db_ctx,
 238                                 uint64_t dev,
 239                                 uint64_t ino,
 240                                 const struct smb_share_mode_entry *new_entry,
 241                                 const char *filename) /* Must be abolute utf8 path. */
 242 {
 243         TDB_DATA db_data;
 244         TDB_DATA locking_key =  get_locking_key(dev, ino);
 245         int orig_num_share_modes = 0;
 246         struct locking_data *ld = NULL; /* internal samba db state. */
 247         struct share_mode_entry *shares = NULL;
 248         char *new_data_p = NULL;
 249         size_t new_data_size = 0;
 250
 251         db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
 252         if (!db_data.dptr) {
 253                 /* We must create the entry. */
 254                 db_data.dptr = malloc((2*sizeof(struct share_mode_entry)) + strlen(filename) + 1);
 255                 if (!db_data.dptr) {
 256                         return -1;
 257                 }
 258                 ld = (struct locking_data *)db_data.dptr;
 259                 ld->u.s.num_share_mode_entries = 1;
 260                 ld->u.s.delete_on_close = 0;
 261                 shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct share_mode_entry));
 262                 create_share_mode_entry(shares, new_entry);
 263                 memcpy(db_data.dptr + 2*sizeof(struct share_mode_entry),
 264                         filename,
 265                         strlen(filename) + 1);
 266
 267                 db_data.dsize = 2*sizeof(struct share_mode_entry) + strlen(filename) + 1;
 268                 if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_INSERT) == -1) {
 269                         free(db_data.dptr);
 270                         return -1;
 271                 }
 272                 free(db_data.dptr);
 273                 return 0;
 274         }
 275
 276         /* Entry exists, we must add a new entry. */
 277         new_data_p = malloc(db_data.dsize + sizeof(struct share_mode_entry));
 278         if (!new_data_p) {
 279                 free(db_data.dptr);
 280                 return -1;
 281         }
 282
 283         ld = (struct locking_data *)db_data.dptr;
 284         orig_num_share_modes = ld->u.s.num_share_mode_entries;
 285
 286         /* Copy the original data. */
 287         memcpy(new_data_p, db_data.dptr, (orig_num_share_modes+1)*sizeof(struct share_mode_entry));
 288
 289         /* Add in the new share mode */
 290         shares = (struct share_mode_entry *)(new_data_p +
 291                         ((orig_num_share_modes+1)*sizeof(struct share_mode_entry)));
 292
 293         create_share_mode_entry(shares, new_entry);
 294
 295         ld = (struct locking_data *)new_data_p;
 296         ld->u.s.num_share_mode_entries++;
 297
 298         /* Append the original filename */
 299         memcpy(new_data_p + ((ld->u.s.num_share_mode_entries+1)*sizeof(struct share_mode_entry)),
 300                 db_data.dptr + ((orig_num_share_modes+1)*sizeof(struct share_mode_entry)),
 301                 db_data.dsize - ((orig_num_share_modes+1) * sizeof(struct share_mode_entry)));
 302
 303         new_data_size = db_data.dsize + sizeof(struct share_mode_entry);
 304
 305         free(db_data.dptr);
 306
 307         db_data.dptr = new_data_p;
 308         db_data.dsize = new_data_size;
 309
 310         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
 311                 free(db_data.dptr);
 312                 return -1;
 313         }
 314         free(db_data.dptr);
 315         return 0;
 316 }
 317
 318 int smb_delete_share_mode_entry(struct smbdb_ctx *db_ctx,
 319                                 uint64_t dev,
 320                                 uint64_t ino,
 321                                 const struct smb_share_mode_entry *del_entry)
 322 {
 323         TDB_DATA db_data;
 324         TDB_DATA locking_key =  get_locking_key(dev, ino);
 325         int orig_num_share_modes = 0;
 326         struct locking_data *ld = NULL; /* internal samba db state. */
 327         struct share_mode_entry *shares = NULL;
 328         char *new_data_p = NULL;
 329         size_t filename_size = 0;
 330         size_t i, num_share_modes;
 331         const char *fname_ptr = NULL;
 332
 333         db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
 334         if (!db_data.dptr) {
 335                 return -1; /* Error - missing entry ! */
 336         }
 337
 338         ld = (struct locking_data *)db_data.dptr;
 339         orig_num_share_modes = ld->u.s.num_share_mode_entries;
 340         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct share_mode_entry));
 341
 342         if (orig_num_share_modes == 1) {
 343                 /* Only one entry - better be ours... */
 344                 if (!share_mode_entry_equal(del_entry, shares)) {
 345                         /* Error ! We can't delete someone else's entry ! */
 346                         free(db_data.dptr);
 347                         return -1;
 348                 }
 349                 /* It's ours - just remove the entire record. */
 350                 free(db_data.dptr);
 351                 return tdb_delete(db_ctx->smb_tdb, locking_key);
 352         }
 353
 354         /* More than one - allocate a new record minus the one we'll delete. */
 355         new_data_p = malloc(db_data.dsize - sizeof(struct share_mode_entry));
 356         if (!new_data_p) {
 357                 free(db_data.dptr);
 358                 return -1;
 359         }
 360
 361         /* Copy the header. */
 362         memcpy(new_data_p, db_data.dptr, sizeof(struct share_mode_entry));
 363
 364         num_share_modes = 0;
 365         for (i = 0; i < orig_num_share_modes; i++) {
 366                 struct share_mode_entry *share = &shares[i];
 367                 pid_t pid = share->pid;
 368
 369                 /* Check this process really exists. */
 370                 if (kill(pid, 0) == -1 && (errno == ESRCH)) {
 371                         continue; /* No longer exists. */
 372                 }
 373
 374                 if (share_mode_entry_equal(del_entry, share)) {
 375                         continue; /* This is our delete taget. */
 376                 }
 377
 378                 memcpy(new_data_p + ((num_share_modes+1)*sizeof(struct share_mode_entry)),
 379                         share, sizeof(struct share_mode_entry) );
 380
 381                 num_share_modes++;
 382         }
 383
 384         if (num_share_modes == 0) {
 385                 /* None left after pruning. Delete record. */
 386                 free(db_data.dptr);
 387                 free(new_data_p);
 388                 return tdb_delete(db_ctx->smb_tdb, locking_key);
 389         }
 390
 391         /* Copy the terminating filename. */
 392         fname_ptr = db_data.dptr + ((orig_num_share_modes+1) * sizeof(struct share_mode_entry));
 393         filename_size = db_data.dsize - (fname_ptr - db_data.dptr);
 394
 395         memcpy(new_data_p + ((num_share_modes+1)*sizeof(struct share_mode_entry)),
 396                 fname_ptr,
 397                 filename_size);
 398
 399         free(db_data.dptr);
 400
 401         db_data.dptr = new_data_p;
 402
 403         /* Re-save smaller record. */
 404         ld = (struct locking_data *)db_data.dptr;
 405         ld->u.s.num_share_mode_entries = num_share_modes;
 406
 407         db_data.dsize = ((num_share_modes+1)*sizeof(struct share_mode_entry)) + filename_size;
 408
 409         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
 410                 free(db_data.dptr);
 411                 return -1;
 412         }
 413         free(db_data.dptr);
 414         return 0;
 415 }
 416
 417 int smb_change_share_mode_entry(struct smbdb_ctx *db_ctx,
 418                                 uint64_t dev,
 419                                 uint64_t ino,
 420                                 const struct smb_share_mode_entry *set_entry,
 421                                 const struct smb_share_mode_entry *new_entry)
 422 {
 423         TDB_DATA db_data;
 424         TDB_DATA locking_key =  get_locking_key(dev, ino);
 425         int num_share_modes = 0;
 426         struct locking_data *ld = NULL; /* internal samba db state. */
 427         struct share_mode_entry *shares = NULL;
 428         size_t i;
 429         int found_entry = 0;
 430
 431         db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
 432         if (!db_data.dptr) {
 433                 return -1; /* Error - missing entry ! */
 434         }
 435
 436         ld = (struct locking_data *)db_data.dptr;
 437         num_share_modes = ld->u.s.num_share_mode_entries;
 438         shares = (struct share_mode_entry *)(db_data.dptr + sizeof(struct share_mode_entry));
 439
 440         for (i = 0; i < num_share_modes; i++) {
 441                 struct share_mode_entry *share = &shares[i];
 442                 pid_t pid = share->pid;
 443
 444                 /* Check this process really exists. */
 445                 if (kill(pid, 0) == -1 && (errno == ESRCH)) {
 446                         continue; /* No longer exists. */
 447                 }
 448
 449                 if (share_mode_entry_equal(set_entry, share)) {
 450                         create_share_mode_entry(share, new_entry);
 451                         found_entry = 1;
 452                         break;
 453                 }
 454         }
 455
 456         if (!found_entry) {
 457                 free(db_data.dptr);
 458                 return -1;
 459         }
 460
 461         /* Save modified data. */
 462         if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
 463                 free(db_data.dptr);
 464                 return -1;
 465         }
 466         free(db_data.dptr);
 467         return 0;
 468 }