root/src/vfs/sfs/sfs.c

/*   */

DEFINITIONS

1. cachedfile_compare
2. sfs_vfmake
3. sfs_redirect
4. sfs_open
5. sfs_stat
6. sfs_lstat
7. sfs_chmod
8. sfs_chown
9. sfs_utime
10. sfs_readlink
11. sfs_getid
12. sfs_free
13. sfs_fill_names
14. sfs_nothingisopen
15. sfs_getlocalcopy
16. sfs_ungetlocalcopy
17. sfs_init
18. sfs_done
19. sfs_which
20. vfs_init_sfs

   1 /*
   2    Single File fileSystem
   3 
   4    Copyright (C) 1998-2020
   5    Free Software Foundation, Inc.
   6 
   7    Written by:
   8    Slava Zanko <slavazanko@gmail.com>, 2013
   9 
  10    This file is part of the Midnight Commander.
  11 
  12    The Midnight Commander is free software: you can redistribute it
  13    and/or modify it under the terms of the GNU General Public License as
  14    published by the Free Software Foundation, either version 3 of the License,
  15    or (at your option) any later version.
  16 
  17    The Midnight Commander is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21 
  22    You should have received a copy of the GNU General Public License
  23    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25 
  26 /**
  27  * \file
  28  * \brief Source: Single File fileSystem
  29  *
  30  * This defines whole class of filesystems which contain single file
  31  * inside. It is somehow similar to extfs, except that extfs makes
  32  * whole virtual trees and we do only single virtual files.
  33  *
  34  * If you want to gunzip something, you should open it with \verbatim #ugz \endverbatim
  35  * suffix, DON'T try to gunzip it yourself.
  36  *
  37  * Namespace: exports vfs_sfs_ops
  38  */
  39 
  40 #include <config.h>
  41 #include <errno.h>
  42 #include <sys/types.h>
  43 #include <unistd.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 
  47 #include "lib/global.h"
  48 #include "lib/util.h"
  49 #include "lib/widget.h"         /* D_ERROR, D_NORMAL */
  50 
  51 #include "src/execute.h"        /* EXECUTE_AS_SHELL */
  52 
  53 #include "lib/vfs/vfs.h"
  54 #include "lib/vfs/utilvfs.h"
  55 #include "lib/vfs/xdirentry.h"
  56 #include "src/vfs/local/local.h"
  57 #include "lib/vfs/gc.h"         /* vfs_stamp_create */
  58 
  59 #include "sfs.h"
  60 
  61 /*** global variables ****************************************************************************/
  62 
  63 /*** file scope macro definitions ****************************************************************/
  64 
  65 #define MAXFS 32
  66 
  67 typedef enum
  68 {
  69     F_NONE = 0x0,
  70     F_1 = 0x1,
  71     F_2 = 0x2,
  72     F_NOLOCALCOPY = 0x4,
  73     F_FULLMATCH = 0x8
  74 } sfs_flags_t;
  75 
  76 #define COPY_CHAR \
  77     if ((size_t) (t - pad) > sizeof (pad)) \
  78     { \
  79         g_free (pqname); \
  80         return (-1); \
  81     } \
  82     else \
  83         *t++ = *s_iter;
  84 
  85 #define COPY_STRING(a) \
  86     if ((t - pad) + strlen (a) > sizeof (pad)) \
  87     { \
  88         g_free (pqname); \
  89         return (-1); \
  90     } \
  91     else \
  92     { \
  93         strcpy (t, a); \
  94         t += strlen (a); \
  95     }
  96 
  97 /*** file scope type declarations ****************************************************************/
  98 
  99 typedef struct cachedfile
 100 {
 101     char *name;
 102     char *cache;
 103 } cachedfile;
 104 
 105 /*** file scope variables ************************************************************************/
 106 
 107 static GSList *head = NULL;
 108 
 109 static struct vfs_s_subclass sfs_subclass;
 110 static struct vfs_class *vfs_sfs_ops = VFS_CLASS (&sfs_subclass);
 111 
 112 static int sfs_no = 0;
 113 static struct
 114 {
 115     char *prefix;
 116     char *command;
 117     sfs_flags_t flags;
 118 } sfs_info[MAXFS];
 119 
 120 /*** file scope functions ************************************************************************/
 121 
 122 static int
 123 cachedfile_compare (const void *a, const void *b)
     /*   */
 124 {
 125     const cachedfile *cf = (const cachedfile *) a;
 126     const char *name = (const char *) b;
 127 
 128     return strcmp (name, cf->name);
 129 }
 130 
 131 /* --------------------------------------------------------------------------------------------- */
 132 
 133 static int
 134 sfs_vfmake (const vfs_path_t * vpath, vfs_path_t * cache_vpath)
     /*   */
 135 {
 136     int w;
 137     char pad[10240];
 138     char *s_iter, *t = pad;
 139     gboolean was_percent = FALSE;
 140     vfs_path_t *pname;          /* name of parent archive */
 141     char *pqname;               /* name of parent archive, quoted */
 142     const vfs_path_element_t *path_element;
 143 
 144     path_element = vfs_path_get_by_index (vpath, -1);
 145     pname = vfs_path_clone (vpath);
 146     vfs_path_remove_element_by_index (pname, -1);
 147 
 148     w = path_element->class->which (path_element->class, path_element->vfs_prefix);
 149     if (w == -1)
 150         vfs_die ("This cannot happen... Hopefully.\n");
 151 
 152     if ((sfs_info[w].flags & F_1) == 0
 153         && strcmp (vfs_path_get_last_path_str (pname), PATH_SEP_STR) != 0)
 154     {
 155         vfs_path_free (pname);
 156         return (-1);
 157     }
 158 
 159     /*    if ((sfs_info[w].flags & F_2) || (!inpath) || (!*inpath)); else return -1; */
 160     if ((sfs_info[w].flags & F_NOLOCALCOPY) != 0)
 161         pqname = name_quote (vfs_path_as_str (pname), FALSE);
 162     else
 163     {
 164         vfs_path_t *s;
 165 
 166         s = mc_getlocalcopy (pname);
 167         if (s == NULL)
 168         {
 169             vfs_path_free (pname);
 170             return (-1);
 171         }
 172 
 173         pqname = name_quote (vfs_path_get_last_path_str (s), FALSE);
 174         vfs_path_free (s);
 175     }
 176 
 177     vfs_path_free (pname);
 178 
 179     for (s_iter = sfs_info[w].command; *s_iter != '\0'; s_iter++)
 180     {
 181         if (was_percent)
 182         {
 183             const char *ptr = NULL;
 184 
 185             was_percent = FALSE;
 186 
 187             switch (*s_iter)
 188             {
 189             case '1':
 190                 ptr = pqname;
 191                 break;
 192             case '2':
 193                 ptr = path_element->path;
 194                 break;
 195             case '3':
 196                 ptr = vfs_path_get_by_index (cache_vpath, -1)->path;
 197                 break;
 198             case '%':
 199                 COPY_CHAR;
 200                 continue;
 201             default:
 202                 break;
 203             }
 204 
 205             if (ptr != NULL)
 206             {
 207                 COPY_STRING (ptr);
 208             }
 209         }
 210         else if (*s_iter == '%')
 211             was_percent = TRUE;
 212         else
 213         {
 214             COPY_CHAR;
 215         }
 216     }
 217 
 218     g_free (pqname);
 219     open_error_pipe ();
 220     if (my_system (EXECUTE_AS_SHELL, "/bin/sh", pad))
 221     {
 222         close_error_pipe (D_ERROR, NULL);
 223         return (-1);
 224     }
 225 
 226     close_error_pipe (D_NORMAL, NULL);
 227     return 0;                   /* OK */
 228 }
 229 
 230 /* --------------------------------------------------------------------------------------------- */
 231 
 232 static const char *
 233 sfs_redirect (const vfs_path_t * vpath)
     /*   */
 234 {
 235     GSList *cur;
 236     cachedfile *cf;
 237     vfs_path_t *cache_vpath;
 238     int handle;
 239     const vfs_path_element_t *path_element;
 240 
 241     path_element = vfs_path_get_by_index (vpath, -1);
 242     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 243 
 244     if (cur != NULL)
 245     {
 246         cf = (cachedfile *) cur->data;
 247         vfs_stamp (vfs_sfs_ops, cf);
 248         return cf->cache;
 249     }
 250 
 251     handle = vfs_mkstemps (&cache_vpath, "sfs", path_element->path);
 252 
 253     if (handle == -1)
 254         return "/SOMEONE_PLAYING_DIRTY_TMP_TRICKS_ON_US";
 255 
 256     close (handle);
 257 
 258     if (sfs_vfmake (vpath, cache_vpath) == 0)
 259     {
 260         cf = g_new (cachedfile, 1);
 261         cf->name = g_strdup (vfs_path_as_str (vpath));
 262         cf->cache = g_strdup (vfs_path_as_str (cache_vpath));
 263         head = g_slist_prepend (head, cf);
 264         vfs_path_free (cache_vpath);
 265 
 266         vfs_stamp_create (vfs_sfs_ops, (cachedfile *) head->data);
 267         return cf->cache;
 268     }
 269 
 270     mc_unlink (cache_vpath);
 271     vfs_path_free (cache_vpath);
 272     return "/I_MUST_NOT_EXIST";
 273 }
 274 
 275 /* --------------------------------------------------------------------------------------------- */
 276 
 277 static void *
 278 sfs_open (const vfs_path_t * vpath /*struct vfs_class *me, const char *path */ , int flags,
     /*   */
 279           mode_t mode)
 280 {
 281     int *info;
 282     int fd;
 283 
 284     fd = open (sfs_redirect (vpath), NO_LINEAR (flags), mode);
 285     if (fd == -1)
 286         return NULL;
 287 
 288     info = g_new (int, 1);
 289     *info = fd;
 290 
 291     return info;
 292 }
 293 
 294 /* --------------------------------------------------------------------------------------------- */
 295 
 296 static int
 297 sfs_stat (const vfs_path_t * vpath, struct stat *buf)
     /*   */
 298 {
 299     return stat (sfs_redirect (vpath), buf);
 300 }
 301 
 302 /* --------------------------------------------------------------------------------------------- */
 303 
 304 static int
 305 sfs_lstat (const vfs_path_t * vpath, struct stat *buf)
     /*   */
 306 {
 307 #ifndef HAVE_STATLSTAT
 308     return lstat (sfs_redirect (vpath), buf);
 309 #else
 310     return statlstat (sfs_redirect (vpath), buf);
 311 #endif
 312 }
 313 
 314 /* --------------------------------------------------------------------------------------------- */
 315 
 316 static int
 317 sfs_chmod (const vfs_path_t * vpath, mode_t mode)
     /*   */
 318 {
 319     return chmod (sfs_redirect (vpath), mode);
 320 }
 321 
 322 /* --------------------------------------------------------------------------------------------- */
 323 
 324 static int
 325 sfs_chown (const vfs_path_t * vpath, uid_t owner, gid_t group)
     /*   */
 326 {
 327     return chown (sfs_redirect (vpath), owner, group);
 328 }
 329 
 330 /* --------------------------------------------------------------------------------------------- */
 331 
 332 static int
 333 sfs_utime (const vfs_path_t * vpath, mc_timesbuf_t * times)
     /*   */
 334 {
 335 #ifdef HAVE_UTIMENSAT
 336     return utimensat (AT_FDCWD, sfs_redirect (vpath), *times, 0);
 337 #else
 338     return utime (sfs_redirect (vpath), times);
 339 #endif
 340 }
 341 
 342 /* --------------------------------------------------------------------------------------------- */
 343 
 344 static int
 345 sfs_readlink (const vfs_path_t * vpath, char *buf, size_t size)
     /*   */
 346 {
 347     return readlink (sfs_redirect (vpath), buf, size);
 348 }
 349 
 350 /* --------------------------------------------------------------------------------------------- */
 351 
 352 static vfsid
 353 sfs_getid (const vfs_path_t * vpath)
     /*   */
 354 {
 355     GSList *cur;
 356 
 357     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 358 
 359     return (vfsid) (cur != NULL ? cur->data : NULL);
 360 }
 361 
 362 /* --------------------------------------------------------------------------------------------- */
 363 
 364 static void
 365 sfs_free (vfsid id)
     /*   */
 366 {
 367     struct cachedfile *which;
 368     GSList *cur;
 369 
 370     which = (struct cachedfile *) id;
 371     cur = g_slist_find (head, which);
 372     if (cur == NULL)
 373         vfs_die ("Free of thing which is unknown to me\n");
 374 
 375     which = (struct cachedfile *) cur->data;
 376     unlink (which->cache);
 377     g_free (which->cache);
 378     g_free (which->name);
 379     g_free (which);
 380 
 381     head = g_slist_delete_link (head, cur);
 382 }
 383 
 384 /* --------------------------------------------------------------------------------------------- */
 385 
 386 static void
 387 sfs_fill_names (struct vfs_class *me, fill_names_f func)
     /*   */
 388 {
 389     GSList *cur;
 390 
 391     (void) me;
 392 
 393     for (cur = head; cur != NULL; cur = g_slist_next (cur))
 394         func (((cachedfile *) cur->data)->name);
 395 }
 396 
 397 /* --------------------------------------------------------------------------------------------- */
 398 
 399 static gboolean
 400 sfs_nothingisopen (vfsid id)
     /*   */
 401 {
 402     /* FIXME: Investigate whether have to guard this like in
 403        the other VFSs (see fd_usage in extfs) -- Norbert */
 404     (void) id;
 405     return TRUE;
 406 }
 407 
 408 /* --------------------------------------------------------------------------------------------- */
 409 
 410 static vfs_path_t *
 411 sfs_getlocalcopy (const vfs_path_t * vpath)
     /*   */
 412 {
 413     return vfs_path_from_str (sfs_redirect (vpath));
 414 }
 415 
 416 /* --------------------------------------------------------------------------------------------- */
 417 
 418 static int
 419 sfs_ungetlocalcopy (const vfs_path_t * vpath, const vfs_path_t * local, gboolean has_changed)
     /*   */
 420 {
 421     (void) vpath;
 422     (void) local;
 423     (void) has_changed;
 424     return 0;
 425 }
 426 
 427 /* --------------------------------------------------------------------------------------------- */
 428 
 429 static int
 430 sfs_init (struct vfs_class *me)
     /*   */
 431 {
 432     char *mc_sfsini;
 433     FILE *cfg;
 434     char key[256];
 435 
 436     (void) me;
 437 
 438     mc_sfsini = g_build_filename (mc_global.sysconfig_dir, "sfs.ini", (char *) NULL);
 439     cfg = fopen (mc_sfsini, "r");
 440 
 441     if (cfg == NULL)
 442     {
 443         fprintf (stderr, _("%s: Warning: file %s not found\n"), "sfs_init()", mc_sfsini);
 444         g_free (mc_sfsini);
 445         return 0;
 446     }
 447     g_free (mc_sfsini);
 448 
 449     sfs_no = 0;
 450     while (sfs_no < MAXFS && fgets (key, sizeof (key), cfg) != NULL)
 451     {
 452         char *c, *semi = NULL;
 453         sfs_flags_t flags = F_NONE;
 454 
 455         if (*key == '#' || *key == '\n')
 456             continue;
 457 
 458         for (c = key; *c != '\0'; c++)
 459             if (*c == ':' || IS_PATH_SEP (*c))
 460             {
 461                 semi = c;
 462                 if (IS_PATH_SEP (*c))
 463                 {
 464                     *c = '\0';
 465                     flags |= F_FULLMATCH;
 466                 }
 467                 break;
 468             }
 469 
 470         if (semi == NULL)
 471         {
 472           invalid_line:
 473             fprintf (stderr, _("Warning: Invalid line in %s:\n%s\n"), "sfs.ini", key);
 474             continue;
 475         }
 476 
 477         for (c = semi + 1; *c != '\0' && !whitespace (*c); c++)
 478             switch (*c)
 479             {
 480             case '1':
 481                 flags |= F_1;
 482                 break;
 483             case '2':
 484                 flags |= F_2;
 485                 break;
 486             case 'R':
 487                 flags |= F_NOLOCALCOPY;
 488                 break;
 489             default:
 490                 fprintf (stderr, _("Warning: Invalid flag %c in %s:\n%s\n"), *c, "sfs.ini", key);
 491             }
 492 
 493         if (*c == '\0')
 494             goto invalid_line;
 495 
 496         c++;
 497         *(semi + 1) = '\0';
 498         semi = strchr (c, '\n');
 499         if (semi != NULL)
 500             *semi = '\0';
 501 
 502         sfs_info[sfs_no].prefix = g_strdup (key);
 503         sfs_info[sfs_no].command = g_strdup (c);
 504         sfs_info[sfs_no].flags = flags;
 505         sfs_no++;
 506     }
 507     fclose (cfg);
 508 
 509     return 1;
 510 }
 511 
 512 /* --------------------------------------------------------------------------------------------- */
 513 
 514 static void
 515 sfs_done (struct vfs_class *me)
     /*   */
 516 {
 517     int i;
 518 
 519     (void) me;
 520 
 521     for (i = 0; i < sfs_no; i++)
 522     {
 523         MC_PTR_FREE (sfs_info[i].prefix);
 524         MC_PTR_FREE (sfs_info[i].command);
 525     }
 526     sfs_no = 0;
 527 }
 528 
 529 /* --------------------------------------------------------------------------------------------- */
 530 
 531 static int
 532 sfs_which (struct vfs_class *me, const char *path)
     /*   */
 533 {
 534     int i;
 535 
 536     (void) me;
 537 
 538     for (i = 0; i < sfs_no; i++)
 539         if ((sfs_info[i].flags & F_FULLMATCH) != 0)
 540         {
 541             if (strcmp (path, sfs_info[i].prefix) == 0)
 542                 return i;
 543         }
 544         else if (strncmp (path, sfs_info[i].prefix, strlen (sfs_info[i].prefix)) == 0)
 545             return i;
 546 
 547     return (-1);
 548 }
 549 
 550 /* --------------------------------------------------------------------------------------------- */
 551 /*** public functions ****************************************************************************/
 552 /* --------------------------------------------------------------------------------------------- */
 553 
 554 void
 555 vfs_init_sfs (void)
     /*   */
 556 {
 557     /* NULLize vfs_s_subclass members */
 558     memset (&sfs_subclass, 0, sizeof (sfs_subclass));
 559 
 560     vfs_init_class (vfs_sfs_ops, "sfs", VFSF_UNKNOWN, NULL);
 561     vfs_sfs_ops->init = sfs_init;
 562     vfs_sfs_ops->done = sfs_done;
 563     vfs_sfs_ops->fill_names = sfs_fill_names;
 564     vfs_sfs_ops->which = sfs_which;
 565     vfs_sfs_ops->open = sfs_open;
 566     vfs_sfs_ops->close = local_close;
 567     vfs_sfs_ops->read = local_read;
 568     vfs_sfs_ops->stat = sfs_stat;
 569     vfs_sfs_ops->lstat = sfs_lstat;
 570     vfs_sfs_ops->fstat = local_fstat;
 571     vfs_sfs_ops->chmod = sfs_chmod;
 572     vfs_sfs_ops->chown = sfs_chown;
 573     vfs_sfs_ops->utime = sfs_utime;
 574     vfs_sfs_ops->readlink = sfs_readlink;
 575     vfs_sfs_ops->ferrno = local_errno;
 576     vfs_sfs_ops->lseek = local_lseek;
 577     vfs_sfs_ops->getid = sfs_getid;
 578     vfs_sfs_ops->nothingisopen = sfs_nothingisopen;
 579     vfs_sfs_ops->free = sfs_free;
 580     vfs_sfs_ops->getlocalcopy = sfs_getlocalcopy;
 581     vfs_sfs_ops->ungetlocalcopy = sfs_ungetlocalcopy;
 582     vfs_register_class (vfs_sfs_ops);
 583 }
 584 
 585 /* --------------------------------------------------------------------------------------------- */

/*   */