lib/vfs/mc-vfs/direntry.c

   1 /** \file
   2  *  \brief Source: directory cache support
   3  *
   4  *  So that you do not have copy of this in each and every filesystem.
   5  *
   6  *  Very loosely based on tar.c from midnight and archives.[ch] from
   7  *  avfs by Miklos Szeredi (mszeredi@inf.bme.hu)
   8  *
   9  *  Unfortunately, I was unable to keep all filesystems
  10  *  uniform. tar-like filesystems use tree structure where each
  11  *  directory has pointers to its subdirectories. We can do this
  12  *  because we have full information about our archive.
  13  *
  14  *  At ftp-like filesystems, situation is a little bit different. When
  15  *  you cd /usr/src/linux/drivers/char, you do _not_ want /usr,
  16  *  /usr/src, /usr/src/linux and /usr/src/linux/drivers to be
  17  *  listed. That means that we do not have complete information, and if
  18  *  /usr is symlink to /4, we will not know. Also we have to time out
  19  *  entries and things would get messy with tree-like approach. So we
  20  *  do different trick: root directory is completely special and
  21  *  completely fake, it contains entries such as 'usr', 'usr/src', ...,
  22  *  and we'll try to use custom find_entry function.
  23  *
  24  *  \author Pavel Machek <pavel@ucw.cz>, distribute under LGPL.
  25  *  \date 1998
  26  *
  27  *  \warning Paths here do _not_ begin with '/', so root directory of
  28  *  archive/site is simply "".
  29  */
  30
  31 #include <config.h>
  32
  33 #include <errno.h>
  34 #include <fcntl.h>              /* include fcntl.h -> sys/fcntl.h only       */
  35                                 /* includes fcntl.h see IEEE Std 1003.1-2008 */
  36 #include <time.h>
  37 #include <sys/time.h>           /* gettimeofday() */
  38
  39 #include "lib/global.h"
  40
  41 #include "lib/tty/tty.h"        /* enable/disable interrupt key */
  42
  43 #include "src/wtools.h"         /* message() */
  44 #include "src/main.h"           /* print_vfs_message */
  45 #include "vfs.h"
  46
  47 #include "utilvfs.h"
  48 #include "vfs-impl.h"
  49 #include "gc.h"                 /* vfs_rmstamp */
  50 #include "xdirentry.h"
  51
  52 #define CALL(x) if (MEDATA->x) MEDATA->x
  53
  54 static volatile int total_inodes = 0, total_entries = 0;
  55
  56 struct vfs_s_inode *
  57 vfs_s_new_inode (struct vfs_class *me, struct vfs_s_super *super, struct stat *initstat)
  58 {
  59     struct vfs_s_inode *ino;
  60
  61     ino = g_try_new0 (struct vfs_s_inode, 1);
  62     if (ino == NULL)
  63         return NULL;
  64
  65     if (initstat)
  66         ino->st = *initstat;
  67     ino->super = super;
  68     ino->st.st_nlink = 0;
  69     ino->st.st_ino = MEDATA->inode_counter++;
  70     ino->st.st_dev = MEDATA->rdev;
  71
  72     super->ino_usage++;
  73     total_inodes++;
  74
  75     CALL (init_inode) (me, ino);
  76
  77     return ino;
  78 }
  79
  80 struct vfs_s_entry *
  81 vfs_s_new_entry (struct vfs_class *me, const char *name, struct vfs_s_inode *inode)
  82 {
  83     struct vfs_s_entry *entry;
  84
  85     entry = g_new0 (struct vfs_s_entry, 1);
  86     total_entries++;
  87
  88     if (name)
  89         entry->name = g_strdup (name);
  90
  91     entry->ino = inode;
  92     entry->ino->ent = entry;
  93     CALL (init_entry) (me, entry);
  94
  95     return entry;
  96 }
  97
  98 static void
  99 vfs_s_free_inode (struct vfs_class *me, struct vfs_s_inode *ino)
 100 {
 101     if (!ino)
 102         vfs_die ("Don't pass NULL to me");
 103
 104     /* ==0 can happen if freshly created entry is deleted */
 105     if (ino->st.st_nlink <= 1)
 106     {
 107         while (ino->subdir)
 108         {
 109             vfs_s_free_entry (me, ino->subdir);
 110         }
 111
 112         CALL (free_inode) (me, ino);
 113         g_free (ino->linkname);
 114         if (ino->localname)
 115         {
 116             unlink (ino->localname);
 117             g_free (ino->localname);
 118         }
 119         total_inodes--;
 120         ino->super->ino_usage--;
 121         g_free (ino);
 122     }
 123     else
 124         ino->st.st_nlink--;
 125 }
 126
 127 void
 128 vfs_s_free_entry (struct vfs_class *me, struct vfs_s_entry *ent)
 129 {
 130     if (ent->prevp)
 131     {
 132         /* It is possible that we are deleting freshly created entry */
 133         *ent->prevp = ent->next;
 134         if (ent->next)
 135             ent->next->prevp = ent->prevp;
 136     }
 137
 138     g_free (ent->name);
 139     ent->name = NULL;
 140
 141     if (ent->ino)
 142     {
 143         ent->ino->ent = NULL;
 144         vfs_s_free_inode (me, ent->ino);
 145         ent->ino = NULL;
 146     }
 147
 148     total_entries--;
 149     g_free (ent);
 150 }
 151
 152 void
 153 vfs_s_insert_entry (struct vfs_class *me, struct vfs_s_inode *dir, struct vfs_s_entry *ent)
 154 {
 155     struct vfs_s_entry **ep;
 156
 157     (void) me;
 158
 159     for (ep = &dir->subdir; *ep != NULL; ep = &((*ep)->next))
 160         ;
 161     ent->prevp = ep;
 162     ent->next = NULL;
 163     ent->dir = dir;
 164     *ep = ent;
 165
 166     ent->ino->st.st_nlink++;
 167 }
 168
 169 struct stat *
 170 vfs_s_default_stat (struct vfs_class *me, mode_t mode)
 171 {
 172     static struct stat st;
 173     int myumask;
 174
 175     (void) me;
 176
 177     myumask = umask (022);
 178     umask (myumask);
 179     mode &= ~myumask;
 180
 181     st.st_mode = mode;
 182     st.st_ino = 0;
 183     st.st_dev = 0;
 184     st.st_rdev = 0;
 185     st.st_uid = getuid ();
 186     st.st_gid = getgid ();
 187     st.st_size = 0;
 188     st.st_mtime = st.st_atime = st.st_ctime = time (NULL);
 189
 190     return &st;
 191 }
 192
 193 struct vfs_s_entry *
 194 vfs_s_generate_entry (struct vfs_class *me, const char *name, struct vfs_s_inode *parent,
 195                       mode_t mode)
 196 {
 197     struct vfs_s_inode *inode;
 198     struct stat *st;
 199
 200     st = vfs_s_default_stat (me, mode);
 201     inode = vfs_s_new_inode (me, parent->super, st);
 202
 203     return vfs_s_new_entry (me, name, inode);
 204 }
 205
 206 /* We were asked to create entries automagically */
 207 static struct vfs_s_entry *
 208 vfs_s_automake (struct vfs_class *me, struct vfs_s_inode *dir, char *path, int flags)
 209 {
 210     struct vfs_s_entry *res;
 211     char *sep = strchr (path, PATH_SEP);
 212
 213     if (sep)
 214         *sep = 0;
 215     res = vfs_s_generate_entry (me, path, dir, flags & FL_MKDIR ? (0777 | S_IFDIR) : 0777);
 216     vfs_s_insert_entry (me, dir, res);
 217
 218     if (sep)
 219         *sep = PATH_SEP;
 220
 221     return res;
 222 }
 223
 224 /* If the entry is a symlink, find the entry for its target */
 225 static struct vfs_s_entry *
 226 vfs_s_resolve_symlink (struct vfs_class *me, struct vfs_s_entry *entry, int follow)
 227 {
 228     char *linkname;
 229     char *fullname = NULL;
 230     struct vfs_s_entry *target;
 231
 232     if (follow == LINK_NO_FOLLOW)
 233         return entry;
 234     if (follow == 0)
 235         ERRNOR (ELOOP, NULL);
 236     if (!entry)
 237         ERRNOR (ENOENT, NULL);
 238     if (!S_ISLNK (entry->ino->st.st_mode))
 239         return entry;
 240
 241     linkname = entry->ino->linkname;
 242     if (linkname == NULL)
 243         ERRNOR (EFAULT, NULL);
 244
 245     /* make full path from relative */
 246     if (*linkname != PATH_SEP)
 247     {
 248         char *fullpath = vfs_s_fullpath (me, entry->dir);
 249         if (fullpath)
 250         {
 251             fullname = g_strconcat (fullpath, "/", linkname, (char *) NULL);
 252             linkname = fullname;
 253             g_free (fullpath);
 254         }
 255     }
 256
 257     target = (MEDATA->find_entry) (me, entry->dir->super->root, linkname, follow - 1, 0);
 258     g_free (fullname);
 259     return target;
 260 }
 261
 262 /*
 263  * Follow > 0: follow links, serves as loop protect,
 264  *       == -1: do not follow links
 265  */
 266 static struct vfs_s_entry *
 267 vfs_s_find_entry_tree (struct vfs_class *me, struct vfs_s_inode *root,
 268                        const char *a_path, int follow, int flags)
 269 {
 270     size_t pseg;
 271     struct vfs_s_entry *ent = NULL;
 272     char *const pathref = g_strdup (a_path);
 273     char *path = pathref;
 274
 275     /* canonicalize as well, but don't remove '../' from path */
 276     custom_canonicalize_pathname (path, CANON_PATH_ALL & (~CANON_PATH_REMDOUBLEDOTS));
 277
 278     while (root)
 279     {
 280         while (*path == PATH_SEP)       /* Strip leading '/' */
 281             path++;
 282
 283         if (!path[0])
 284         {
 285             g_free (pathref);
 286             return ent;
 287         }
 288
 289         for (pseg = 0; path[pseg] && path[pseg] != PATH_SEP; pseg++);
 290
 291         for (ent = root->subdir; ent != NULL; ent = ent->next)
 292             if (strlen (ent->name) == pseg && (!strncmp (ent->name, path, pseg)))
 293                 /* FOUND! */
 294                 break;
 295
 296         if (!ent && (flags & (FL_MKFILE | FL_MKDIR)))
 297             ent = vfs_s_automake (me, root, path, flags);
 298         if (!ent)
 299         {
 300             me->verrno = ENOENT;
 301             goto cleanup;
 302         }
 303         path += pseg;
 304         /* here we must follow leading directories always;
 305            only the actual file is optional */
 306         ent = vfs_s_resolve_symlink (me, ent, strchr (path, PATH_SEP) ? LINK_FOLLOW : follow);
 307         if (!ent)
 308             goto cleanup;
 309         root = ent->ino;
 310     }
 311   cleanup:
 312     g_free (pathref);
 313     return NULL;
 314 }
 315
 316 static void
 317 split_dir_name (struct vfs_class *me, char *path, char **dir, char **name, char **save)
 318 {
 319     char *s;
 320
 321     (void) me;
 322
 323     s = strrchr (path, PATH_SEP);
 324     if (s == NULL)
 325     {
 326         *save = NULL;
 327         *name = path;
 328         *dir = path + strlen (path);    /* an empty string */
 329     }
 330     else
 331     {
 332         *save = s;
 333         *dir = path;
 334         *s++ = '\0';
 335         *name = s;
 336     }
 337 }
 338
 339 static struct vfs_s_entry *
 340 vfs_s_find_entry_linear (struct vfs_class *me, struct vfs_s_inode *root,
 341                          const char *a_path, int follow, int flags)
 342 {
 343     struct vfs_s_entry *ent = NULL;
 344     char *const path = g_strdup (a_path);
 345     struct vfs_s_entry *retval = NULL;
 346
 347     if (root->super->root != root)
 348         vfs_die ("We have to use _real_ root. Always. Sorry.");
 349
 350     /* canonicalize as well, but don't remove '../' from path */
 351     custom_canonicalize_pathname (path, CANON_PATH_ALL & (~CANON_PATH_REMDOUBLEDOTS));
 352
 353     if (!(flags & FL_DIR))
 354     {
 355         char *dirname, *name, *save;
 356         struct vfs_s_inode *ino;
 357         split_dir_name (me, path, &dirname, &name, &save);
 358         ino = vfs_s_find_inode (me, root->super, dirname, follow, flags | FL_DIR);
 359         if (save)
 360             *save = PATH_SEP;
 361         retval = vfs_s_find_entry_tree (me, ino, name, follow, flags);
 362         g_free (path);
 363         return retval;
 364     }
 365
 366     for (ent = root->subdir; ent != NULL; ent = ent->next)
 367         if (!strcmp (ent->name, path))
 368             break;
 369
 370     if (ent && (!(MEDATA->dir_uptodate) (me, ent->ino)))
 371     {
 372 #if 1
 373         print_vfs_message (_("Directory cache expired for %s"), path);
 374 #endif
 375         vfs_s_free_entry (me, ent);
 376         ent = NULL;
 377     }
 378
 379     if (!ent)
 380     {
 381         struct vfs_s_inode *ino;
 382
 383         ino = vfs_s_new_inode (me, root->super, vfs_s_default_stat (me, S_IFDIR | 0755));
 384         ent = vfs_s_new_entry (me, path, ino);
 385         if ((MEDATA->dir_load) (me, ino, path) == -1)
 386         {
 387             vfs_s_free_entry (me, ent);
 388             g_free (path);
 389             return NULL;
 390         }
 391         vfs_s_insert_entry (me, root, ent);
 392
 393         for (ent = root->subdir; ent != NULL; ent = ent->next)
 394             if (!strcmp (ent->name, path))
 395                 break;
 396     }
 397     if (!ent)
 398         vfs_die ("find_linear: success but directory is not there\n");
 399
 400 #if 0
 401     if (!vfs_s_resolve_symlink (me, ent, follow))
 402     {
 403         g_free (path);
 404         return NULL;
 405     }
 406 #endif
 407     g_free (path);
 408     return ent;
 409 }
 410
 411 struct vfs_s_inode *
 412 vfs_s_find_inode (struct vfs_class *me, const struct vfs_s_super *super,
 413                   const char *path, int follow, int flags)
 414 {
 415     struct vfs_s_entry *ent;
 416
 417     if (((MEDATA->flags & VFS_S_REMOTE) == 0) && (*path == '\0'))
 418         return super->root;
 419
 420     ent = (MEDATA->find_entry) (me, super->root, path, follow, flags);
 421     return (ent != NULL) ? ent->ino : NULL;
 422 }
 423
 424 /* Ook, these were functions around directory entries / inodes */
 425 /* -------------------------------- superblock games -------------------------- */
 426
 427 static struct vfs_s_super *
 428 vfs_s_new_super (struct vfs_class *me)
 429 {
 430     struct vfs_s_super *super;
 431
 432     super = g_new0 (struct vfs_s_super, 1);
 433     super->me = me;
 434     return super;
 435 }
 436
 437 static void
 438 vfs_s_insert_super (struct vfs_class *me, struct vfs_s_super *super)
 439 {
 440     super->next = MEDATA->supers;
 441     super->prevp = &MEDATA->supers;
 442
 443     if (MEDATA->supers != NULL)
 444         MEDATA->supers->prevp = &super->next;
 445     MEDATA->supers = super;
 446 }
 447
 448 static void
 449 vfs_s_free_super (struct vfs_class *me, struct vfs_s_super *super)
 450 {
 451     if (super->root)
 452     {
 453         vfs_s_free_inode (me, super->root);
 454         super->root = NULL;
 455     }
 456
 457 #if 0
 458     /* FIXME: We currently leak small ammount of memory, sometimes. Fix it if you can. */
 459     if (super->ino_usage)
 460         message (D_ERROR, " Direntry warning ",
 461                  "Super ino_usage is %d, memory leak", super->ino_usage);
 462
 463     if (super->want_stale)
 464         message (D_ERROR, " Direntry warning ", "Super has want_stale set");
 465 #endif
 466
 467     if (super->prevp)
 468     {
 469         *super->prevp = super->next;
 470         if (super->next)
 471             super->next->prevp = super->prevp;
 472     }
 473
 474     CALL (free_archive) (me, super);
 475     g_free (super->name);
 476     g_free (super);
 477 }
 478
 479
 480 /*
 481  * Dissect the path and create corresponding superblock.  Note that inname
 482  * can be changed and the result may point inside the original string.
 483  */
 484 const char *
 485 vfs_s_get_path_mangle (struct vfs_class *me, char *inname, struct vfs_s_super **archive, int flags)
 486 {
 487     const char *retval;
 488     char *local, *op;
 489     const char *archive_name;
 490     int result = -1;
 491     struct vfs_s_super *super;
 492     void *cookie = NULL;
 493
 494     archive_name = inname;
 495     vfs_split (inname, &local, &op);
 496     retval = (local) ? local : "";
 497
 498     if (MEDATA->archive_check)
 499         if (!(cookie = MEDATA->archive_check (me, archive_name, op)))
 500             return NULL;
 501
 502     for (super = MEDATA->supers; super != NULL; super = super->next)
 503     {
 504         /* 0 == other, 1 == same, return it, 2 == other but stop scanning */
 505         int i = MEDATA->archive_same (me, super, archive_name, op, cookie);
 506         if (i != 0)
 507         {
 508             if (i == 1)
 509                 goto return_success;
 510             else
 511                 break;
 512         }
 513     }
 514
 515     if (flags & FL_NO_OPEN)
 516         ERRNOR (EIO, NULL);
 517
 518     super = vfs_s_new_super (me);
 519     result = MEDATA->open_archive (me, super, archive_name, op);
 520     if (result == -1)
 521     {
 522         vfs_s_free_super (me, super);
 523         ERRNOR (EIO, NULL);
 524     }
 525     if (!super->name)
 526         vfs_die ("You have to fill name\n");
 527     if (!super->root)
 528         vfs_die ("You have to fill root inode\n");
 529
 530     vfs_s_insert_super (me, super);
 531     vfs_stamp_create (me, super);
 532
 533   return_success:
 534     *archive = super;
 535     return retval;
 536 }
 537
 538
 539 /*
 540  * Dissect the path and create corresponding superblock.
 541  * The result should be freed.
 542  */
 543 static char *
 544 vfs_s_get_path (struct vfs_class *me, const char *inname, struct vfs_s_super **archive, int flags)
 545 {
 546     char *buf, *retval;
 547
 548     buf = g_strdup (inname);
 549     retval = g_strdup (vfs_s_get_path_mangle (me, buf, archive, flags));
 550     g_free (buf);
 551     return retval;
 552 }
 553
 554 void
 555 vfs_s_invalidate (struct vfs_class *me, struct vfs_s_super *super)
 556 {
 557     if (!super->want_stale)
 558     {
 559         vfs_s_free_inode (me, super->root);
 560         super->root = vfs_s_new_inode (me, super, vfs_s_default_stat (me, S_IFDIR | 0755));
 561     }
 562 }
 563
 564 char *
 565 vfs_s_fullpath (struct vfs_class *me, struct vfs_s_inode *ino)
 566 {
 567     if (!ino->ent)
 568         ERRNOR (EAGAIN, NULL);
 569
 570     if (!(MEDATA->flags & VFS_S_REMOTE))
 571     {
 572         /* archives */
 573         char *newpath;
 574         char *path = g_strdup (ino->ent->name);
 575         while (1)
 576         {
 577             ino = ino->ent->dir;
 578             if (ino == ino->super->root)
 579                 break;
 580             newpath = g_strconcat (ino->ent->name, "/", path, (char *) NULL);
 581             g_free (path);
 582             path = newpath;
 583         }
 584         return path;
 585     }
 586
 587     /* remote systems */
 588     if ((!ino->ent->dir) || (!ino->ent->dir->ent))
 589         return g_strdup (ino->ent->name);
 590
 591     return g_strconcat (ino->ent->dir->ent->name, PATH_SEP_STR, ino->ent->name, (char *) NULL);
 592 }
 593
 594 /* Support of archives */
 595 /* ------------------------ readdir & friends ----------------------------- */
 596
 597 static struct vfs_s_inode *
 598 vfs_s_inode_from_path (struct vfs_class *me, const char *name, int flags)
 599 {
 600     struct vfs_s_super *super;
 601     struct vfs_s_inode *ino;
 602     char *q;
 603
 604     if (!(q = vfs_s_get_path (me, name, &super, 0)))
 605         return NULL;
 606
 607     ino =
 608         vfs_s_find_inode (me, super, q,
 609                           flags & FL_FOLLOW ? LINK_FOLLOW : LINK_NO_FOLLOW, flags & ~FL_FOLLOW);
 610     if ((!ino) && (!*q))
 611         /* We are asking about / directory of ftp server: assume it exists */
 612         ino =
 613             vfs_s_find_inode (me, super, q,
 614                               flags & FL_FOLLOW ? LINK_FOLLOW :
 615                               LINK_NO_FOLLOW, FL_DIR | (flags & ~FL_FOLLOW));
 616     g_free (q);
 617     return ino;
 618 }
 619
 620 struct dirhandle
 621 {
 622     struct vfs_s_entry *cur;
 623     struct vfs_s_inode *dir;
 624 };
 625
 626 static void *
 627 vfs_s_opendir (struct vfs_class *me, const char *dirname)
 628 {
 629     struct vfs_s_inode *dir;
 630     struct dirhandle *info;
 631
 632     dir = vfs_s_inode_from_path (me, dirname, FL_DIR | FL_FOLLOW);
 633     if (!dir)
 634         return NULL;
 635     if (!S_ISDIR (dir->st.st_mode))
 636         ERRNOR (ENOTDIR, NULL);
 637
 638     dir->st.st_nlink++;
 639 #if 0
 640     if (!dir->subdir)           /* This can actually happen if we allow empty directories */
 641         ERRNOR (EAGAIN, NULL);
 642 #endif
 643     info = g_new (struct dirhandle, 1);
 644     info->cur = dir->subdir;
 645     info->dir = dir;
 646
 647     return info;
 648 }
 649
 650 static void *
 651 vfs_s_readdir (void *data)
 652 {
 653     static union vfs_dirent dir;
 654     struct dirhandle *info = (struct dirhandle *) data;
 655
 656     if (!(info->cur))
 657         return NULL;
 658
 659     if (info->cur->name)
 660     {
 661         g_strlcpy (dir.dent.d_name, info->cur->name, MC_MAXPATHLEN);
 662     }
 663     else
 664     {
 665         vfs_die ("Null in structure-cannot happen");
 666     }
 667
 668     compute_namelen (&dir.dent);
 669     info->cur = info->cur->next;
 670
 671     return (void *) &dir;
 672 }
 673
 674 static int
 675 vfs_s_closedir (void *data)
 676 {
 677     struct dirhandle *info = (struct dirhandle *) data;
 678     struct vfs_s_inode *dir = info->dir;
 679
 680     vfs_s_free_inode (dir->super->me, dir);
 681     g_free (data);
 682     return 0;
 683 }
 684
 685 static int
 686 vfs_s_chdir (struct vfs_class *me, const char *path)
 687 {
 688     void *data;
 689     if (!(data = vfs_s_opendir (me, path)))
 690         return -1;
 691     vfs_s_closedir (data);
 692     return 0;
 693 }
 694
 695 /* --------------------------- stat and friends ---------------------------- */
 696
 697 static int
 698 vfs_s_internal_stat (struct vfs_class *me, const char *path, struct stat *buf, int flag)
 699 {
 700     struct vfs_s_inode *ino;
 701
 702     if (!(ino = vfs_s_inode_from_path (me, path, flag)))
 703         return -1;
 704     *buf = ino->st;
 705     return 0;
 706 }
 707
 708 static int
 709 vfs_s_stat (struct vfs_class *me, const char *path, struct stat *buf)
 710 {
 711     return vfs_s_internal_stat (me, path, buf, FL_FOLLOW);
 712 }
 713
 714 static int
 715 vfs_s_lstat (struct vfs_class *me, const char *path, struct stat *buf)
 716 {
 717     return vfs_s_internal_stat (me, path, buf, FL_NONE);
 718 }
 719
 720 static int
 721 vfs_s_fstat (void *fh, struct stat *buf)
 722 {
 723     *buf = FH->ino->st;
 724     return 0;
 725 }
 726
 727 static int
 728 vfs_s_readlink (struct vfs_class *me, const char *path, char *buf, size_t size)
 729 {
 730     struct vfs_s_inode *ino;
 731     size_t len;
 732
 733     ino = vfs_s_inode_from_path (me, path, 0);
 734     if (!ino)
 735         return -1;
 736
 737     if (!S_ISLNK (ino->st.st_mode))
 738         ERRNOR (EINVAL, -1);
 739
 740     if (ino->linkname == NULL)
 741         ERRNOR (EFAULT, -1);
 742
 743     len = strlen (ino->linkname);
 744     if (size < len)
 745         len = size;
 746     /* readlink() does not append a NUL character to buf */
 747     memcpy (buf, ino->linkname, len);
 748     return len;
 749 }
 750
 751 void *
 752 vfs_s_open (struct vfs_class *me, const char *file, int flags, int mode)
 753 {
 754     int was_changed = 0;
 755     struct vfs_s_fh *fh;
 756     struct vfs_s_super *super;
 757     char *q;
 758     struct vfs_s_inode *ino;
 759
 760     if ((q = vfs_s_get_path (me, file, &super, 0)) == NULL)
 761         return NULL;
 762     ino = vfs_s_find_inode (me, super, q, LINK_FOLLOW, FL_NONE);
 763     if (ino && ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)))
 764     {
 765         g_free (q);
 766         ERRNOR (EEXIST, NULL);
 767     }
 768     if (!ino)
 769     {
 770         char *dirname, *name, *save;
 771         struct vfs_s_entry *ent;
 772         struct vfs_s_inode *dir;
 773         int tmp_handle;
 774
 775         /* If the filesystem is read-only, disable file creation */
 776         if (!(flags & O_CREAT) || !(me->write))
 777         {
 778             g_free (q);
 779             return NULL;
 780         }
 781
 782         split_dir_name (me, q, &dirname, &name, &save);
 783         /* FIXME: check if vfs_s_find_inode returns NULL */
 784         dir = vfs_s_find_inode (me, super, dirname, LINK_FOLLOW, FL_DIR);
 785         if (save)
 786             *save = PATH_SEP;
 787         ent = vfs_s_generate_entry (me, name, dir, 0755);
 788         ino = ent->ino;
 789         vfs_s_insert_entry (me, dir, ent);
 790         tmp_handle = vfs_mkstemps (&ino->localname, me->name, name);
 791         if (tmp_handle == -1)
 792         {
 793             g_free (q);
 794             return NULL;
 795         }
 796         close (tmp_handle);
 797         was_changed = 1;
 798     }
 799
 800     g_free (q);
 801
 802     if (S_ISDIR (ino->st.st_mode))
 803         ERRNOR (EISDIR, NULL);
 804
 805     fh = g_new (struct vfs_s_fh, 1);
 806     fh->pos = 0;
 807     fh->ino = ino;
 808     fh->handle = -1;
 809     fh->changed = was_changed;
 810     fh->linear = 0;
 811
 812     if (IS_LINEAR (flags))
 813     {
 814         if (MEDATA->linear_start)
 815         {
 816             print_vfs_message (_("Starting linear transfer..."));
 817             fh->linear = LS_LINEAR_PREOPEN;
 818         }
 819     }
 820     else if ((MEDATA->fh_open) && (MEDATA->fh_open (me, fh, flags, mode)))
 821     {
 822         g_free (fh);
 823         return NULL;
 824     }
 825
 826     if (fh->ino->localname)
 827     {
 828         fh->handle = open (fh->ino->localname, NO_LINEAR (flags), mode);
 829         if (fh->handle == -1)
 830         {
 831             g_free (fh);
 832             ERRNOR (errno, NULL);
 833         }
 834     }
 835
 836     /* i.e. we had no open files and now we have one */
 837     vfs_rmstamp (me, (vfsid) super);
 838     super->fd_usage++;
 839     fh->ino->st.st_nlink++;
 840     return fh;
 841 }
 842
 843 static ssize_t
 844 vfs_s_read (void *fh, char *buffer, int count)
 845 {
 846     int n;
 847     struct vfs_class *me = FH_SUPER->me;
 848
 849     if (FH->linear == LS_LINEAR_PREOPEN)
 850     {
 851         if (!MEDATA->linear_start (me, FH, FH->pos))
 852             return -1;
 853     }
 854
 855     if (FH->linear == LS_LINEAR_CLOSED)
 856         vfs_die ("linear_start() did not set linear_state!");
 857
 858     if (FH->linear == LS_LINEAR_OPEN)
 859         return MEDATA->linear_read (me, FH, buffer, count);
 860
 861     if (FH->handle != -1)
 862     {
 863         n = read (FH->handle, buffer, count);
 864         if (n < 0)
 865             me->verrno = errno;
 866         return n;
 867     }
 868     vfs_die ("vfs_s_read: This should not happen\n");
 869     return -1;
 870 }
 871
 872 static ssize_t
 873 vfs_s_write (void *fh, const char *buffer, int count)
 874 {
 875     int n;
 876     struct vfs_class *me = FH_SUPER->me;
 877
 878     if (FH->linear)
 879         vfs_die ("no writing to linear files, please");
 880
 881     FH->changed = 1;
 882     if (FH->handle != -1)
 883     {
 884         n = write (FH->handle, buffer, count);
 885         if (n < 0)
 886             me->verrno = errno;
 887         return n;
 888     }
 889     vfs_die ("vfs_s_write: This should not happen\n");
 890     return 0;
 891 }
 892
 893 static off_t
 894 vfs_s_lseek (void *fh, off_t offset, int whence)
 895 {
 896     off_t size = FH->ino->st.st_size;
 897
 898     if (FH->linear == LS_LINEAR_OPEN)
 899         vfs_die ("cannot lseek() after linear_read!");
 900
 901     if (FH->handle != -1)
 902     {                           /* If we have local file opened, we want to work with it */
 903         int retval = lseek (FH->handle, offset, whence);
 904         if (retval == -1)
 905             FH->ino->super->me->verrno = errno;
 906         return retval;
 907     }
 908
 909     switch (whence)
 910     {
 911     case SEEK_CUR:
 912         offset += FH->pos;
 913         break;
 914     case SEEK_END:
 915         offset += size;
 916         break;
 917     }
 918     if (offset < 0)
 919         FH->pos = 0;
 920     else if (offset < size)
 921         FH->pos = offset;
 922     else
 923         FH->pos = size;
 924     return FH->pos;
 925 }
 926
 927 static int
 928 vfs_s_close (void *fh)
 929 {
 930     int res = 0;
 931     struct vfs_class *me = FH_SUPER->me;
 932
 933     FH_SUPER->fd_usage--;
 934     if (!FH_SUPER->fd_usage)
 935         vfs_stamp_create (me, FH_SUPER);
 936
 937     if (FH->linear == LS_LINEAR_OPEN)
 938         MEDATA->linear_close (me, fh);
 939     if (MEDATA->fh_close)
 940         res = MEDATA->fh_close (me, fh);
 941     if (FH->changed && MEDATA->file_store)
 942     {
 943         char *s = vfs_s_fullpath (me, FH->ino);
 944         if (!s)
 945             res = -1;
 946         else
 947         {
 948             res = MEDATA->file_store (me, fh, s, FH->ino->localname);
 949             g_free (s);
 950         }
 951         vfs_s_invalidate (me, FH_SUPER);
 952     }
 953     if (FH->handle != -1)
 954         close (FH->handle);
 955
 956     vfs_s_free_inode (me, FH->ino);
 957     g_free (fh);
 958     return res;
 959 }
 960
 961 static void
 962 vfs_s_print_stats (const char *fs_name, const char *action,
 963                    const char *file_name, off_t have, off_t need)
 964 {
 965     static const char *i18n_percent_transf_format = NULL;
 966     static const char *i18n_transf_format = NULL;
 967
 968     if (i18n_percent_transf_format == NULL)
 969     {
 970         i18n_percent_transf_format = _("%s: %s: %s %3d%% (%lu bytes transferred)");
 971         i18n_transf_format = _("%s: %s: %s %lu bytes transferred");
 972     }
 973
 974     if (need)
 975         print_vfs_message (i18n_percent_transf_format, fs_name, action,
 976                            file_name, (int) ((double) have * 100 / need), (unsigned long) have);
 977     else
 978         print_vfs_message (i18n_transf_format, fs_name, action, file_name, (unsigned long) have);
 979 }
 980
 981 int
 982 vfs_s_retrieve_file (struct vfs_class *me, struct vfs_s_inode *ino)
 983 {
 984     /* If you want reget, you'll have to open file with O_LINEAR */
 985     off_t total = 0;
 986     char buffer[8192];
 987     int handle, n;
 988     off_t stat_size = ino->st.st_size;
 989     struct vfs_s_fh fh;
 990
 991     memset (&fh, 0, sizeof (fh));
 992
 993     fh.ino = ino;
 994     fh.handle = -1;
 995
 996     handle = vfs_mkstemps (&ino->localname, me->name, ino->ent->name);
 997     if (handle == -1)
 998     {
 999         me->verrno = errno;
1000         goto error_4;
1001     }
1002
1003     if (!MEDATA->linear_start (me, &fh, 0))
1004         goto error_3;
1005
1006     /* Clear the interrupt status */
1007     tty_got_interrupt ();
1008     tty_enable_interrupt_key ();
1009
1010     while ((n = MEDATA->linear_read (me, &fh, buffer, sizeof (buffer))))
1011     {
1012         int t;
1013         if (n < 0)
1014             goto error_1;
1015
1016         total += n;
1017         vfs_s_print_stats (me->name, _("Getting file"), ino->ent->name, total, stat_size);
1018
1019         if (tty_got_interrupt ())
1020             goto error_1;
1021
1022         t = write (handle, buffer, n);
1023         if (t != n)
1024         {
1025             if (t == -1)
1026                 me->verrno = errno;
1027             goto error_1;
1028         }
1029     }
1030     MEDATA->linear_close (me, &fh);
1031     close (handle);
1032
1033     tty_disable_interrupt_key ();
1034     return 0;
1035
1036   error_1:
1037     MEDATA->linear_close (me, &fh);
1038   error_3:
1039     tty_disable_interrupt_key ();
1040     close (handle);
1041     unlink (ino->localname);
1042   error_4:
1043     g_free (ino->localname);
1044     ino->localname = NULL;
1045     return -1;
1046 }
1047
1048 /* ------------------------------- mc support ---------------------------- */
1049
1050 static void
1051 vfs_s_fill_names (struct vfs_class *me, fill_names_f func)
1052 {
1053     struct vfs_s_super *a = MEDATA->supers;
1054     char *name;
1055
1056     while (a)
1057     {
1058         name = g_strconcat (a->name, "#", me->prefix, "/",
1059                             /* a->current_dir->name, */ (char *) NULL);
1060         (*func) (name);
1061         g_free (name);
1062         a = a->next;
1063     }
1064 }
1065
1066 static int
1067 vfs_s_ferrno (struct vfs_class *me)
1068 {
1069     return me->verrno;
1070 }
1071
1072 /*
1073  * Get local copy of the given file.  We reuse the existing file cache
1074  * for remote filesystems.  Archives use standard VFS facilities.
1075  */
1076 static char *
1077 vfs_s_getlocalcopy (struct vfs_class *me, const char *path)
1078 {
1079     struct vfs_s_fh *fh;
1080     char *local = NULL;
1081
1082     fh = vfs_s_open (me, path, O_RDONLY, 0);
1083
1084     if (fh != NULL)
1085     {
1086         if ((fh->ino != NULL) && (fh->ino->localname != NULL))
1087             local = g_strdup (fh->ino->localname);
1088
1089         vfs_s_close (fh);
1090     }
1091
1092     return local;
1093 }
1094
1095 /*
1096  * Return the local copy.  Since we are using our cache, we do nothing -
1097  * the cache will be removed when the archive is closed.
1098  */
1099 static int
1100 vfs_s_ungetlocalcopy (struct vfs_class *me, const char *path, const char *local, int has_changed)
1101 {
1102     (void) me;
1103     (void) path;
1104     (void) local;
1105     (void) has_changed;
1106     return 0;
1107 }
1108
1109 static int
1110 vfs_s_setctl (struct vfs_class *me, const char *path, int ctlop, void *arg)
1111 {
1112     switch (ctlop)
1113     {
1114     case VFS_SETCTL_STALE_DATA:
1115         {
1116             struct vfs_s_inode *ino = vfs_s_inode_from_path (me, path, 0);
1117
1118             if (!ino)
1119                 return 0;
1120             if (arg)
1121                 ino->super->want_stale = 1;
1122             else
1123             {
1124                 ino->super->want_stale = 0;
1125                 vfs_s_invalidate (me, ino->super);
1126             }
1127             return 1;
1128         }
1129     case VFS_SETCTL_LOGFILE:
1130         MEDATA->logfile = fopen ((char *) arg, "w");
1131         return 1;
1132     case VFS_SETCTL_FLUSH:
1133         MEDATA->flush = 1;
1134         return 1;
1135     }
1136     return 0;
1137 }
1138
1139
1140 /* ----------------------------- Stamping support -------------------------- */
1141
1142 static vfsid
1143 vfs_s_getid (struct vfs_class *me, const char *path)
1144 {
1145     struct vfs_s_super *archive;
1146     char *p;
1147
1148     if (!(p = vfs_s_get_path (me, path, &archive, FL_NO_OPEN)))
1149         return NULL;
1150     g_free (p);
1151     return (vfsid) archive;
1152 }
1153
1154 static int
1155 vfs_s_nothingisopen (vfsid id)
1156 {
1157     (void) id;
1158     /* Our data structures should survive free of superblock at any time */
1159     return 1;
1160 }
1161
1162 static void
1163 vfs_s_free (vfsid id)
1164 {
1165     vfs_s_free_super (((struct vfs_s_super *) id)->me, (struct vfs_s_super *) id);
1166 }
1167
1168 static int
1169 vfs_s_dir_uptodate (struct vfs_class *me, struct vfs_s_inode *ino)
1170 {
1171     struct timeval tim;
1172
1173     if (MEDATA->flush)
1174     {
1175         MEDATA->flush = 0;
1176         return 0;
1177     }
1178
1179     gettimeofday (&tim, NULL);
1180     if (tim.tv_sec < ino->timestamp.tv_sec)
1181         return 1;
1182     return 0;
1183 }
1184
1185 /* Initialize one of our subclasses - fill common functions */
1186 void
1187 vfs_s_init_class (struct vfs_class *vclass, struct vfs_s_subclass *sub)
1188 {
1189     vclass->data = sub;
1190     vclass->fill_names = vfs_s_fill_names;
1191     vclass->open = vfs_s_open;
1192     vclass->close = vfs_s_close;
1193     vclass->read = vfs_s_read;
1194     if (!(sub->flags & VFS_S_READONLY))
1195     {
1196         vclass->write = vfs_s_write;
1197     }
1198     vclass->opendir = vfs_s_opendir;
1199     vclass->readdir = vfs_s_readdir;
1200     vclass->closedir = vfs_s_closedir;
1201     vclass->stat = vfs_s_stat;
1202     vclass->lstat = vfs_s_lstat;
1203     vclass->fstat = vfs_s_fstat;
1204     vclass->readlink = vfs_s_readlink;
1205     vclass->chdir = vfs_s_chdir;
1206     vclass->ferrno = vfs_s_ferrno;
1207     vclass->lseek = vfs_s_lseek;
1208     vclass->getid = vfs_s_getid;
1209     vclass->nothingisopen = vfs_s_nothingisopen;
1210     vclass->free = vfs_s_free;
1211     if (sub->flags & VFS_S_REMOTE)
1212     {
1213         vclass->getlocalcopy = vfs_s_getlocalcopy;
1214         vclass->ungetlocalcopy = vfs_s_ungetlocalcopy;
1215         sub->find_entry = vfs_s_find_entry_linear;
1216     }
1217     else
1218     {
1219         sub->find_entry = vfs_s_find_entry_tree;
1220     }
1221     vclass->setctl = vfs_s_setctl;
1222     sub->dir_uptodate = vfs_s_dir_uptodate;
1223 }
1224
1225 /* ----------- Utility functions for networked filesystems  -------------- */
1226
1227 #ifdef USE_NETCODE
1228 int
1229 vfs_s_select_on_two (int fd1, int fd2)
1230 {
1231     fd_set set;
1232     struct timeval time_out;
1233     int v;
1234     int maxfd = (fd1 > fd2 ? fd1 : fd2) + 1;
1235
1236     time_out.tv_sec = 1;
1237     time_out.tv_usec = 0;
1238     FD_ZERO (&set);
1239     FD_SET (fd1, &set);
1240     FD_SET (fd2, &set);
1241     v = select (maxfd, &set, 0, 0, &time_out);
1242     if (v <= 0)
1243         return v;
1244     if (FD_ISSET (fd1, &set))
1245         return 1;
1246     if (FD_ISSET (fd2, &set))
1247         return 2;
1248     return -1;
1249 }
1250
1251 int
1252 vfs_s_get_line (struct vfs_class *me, int sock, char *buf, int buf_len, char term)
1253 {
1254     FILE *logfile = MEDATA->logfile;
1255     int i;
1256     char c;
1257
1258     for (i = 0; i < buf_len - 1; i++, buf++)
1259     {
1260         if (read (sock, buf, sizeof (char)) <= 0)
1261             return 0;
1262         if (logfile)
1263         {
1264             fwrite (buf, 1, 1, logfile);
1265             fflush (logfile);
1266         }
1267         if (*buf == term)
1268         {
1269             *buf = 0;
1270             return 1;
1271         }
1272     }
1273
1274     /* Line is too long - terminate buffer and discard the rest of line */
1275     *buf = 0;
1276     while (read (sock, &c, sizeof (c)) > 0)
1277     {
1278         if (logfile)
1279         {
1280             fwrite (&c, 1, 1, logfile);
1281             fflush (logfile);
1282         }
1283         if (c == '\n')
1284             return 1;
1285     }
1286     return 0;
1287 }
1288
1289 int
1290 vfs_s_get_line_interruptible (struct vfs_class *me, char *buffer, int size, int fd)
1291 {
1292     int n;
1293     int i;
1294
1295     (void) me;
1296
1297     tty_enable_interrupt_key ();
1298     for (i = 0; i < size - 1; i++)
1299     {
1300         n = read (fd, buffer + i, 1);
1301         tty_disable_interrupt_key ();
1302         if (n == -1 && errno == EINTR)
1303         {
1304             buffer[i] = 0;
1305             return EINTR;
1306         }
1307         if (n == 0)
1308         {
1309             buffer[i] = 0;
1310             return 0;
1311         }
1312         if (buffer[i] == '\n')
1313         {
1314             buffer[i] = 0;
1315             return 1;
1316         }
1317     }
1318     buffer[size - 1] = 0;
1319     return 0;
1320 }
1321 #endif /* USE_NETCODE */