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) 1998-2021
   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     mc_pipe_t *pip;
 144     GError *error = NULL;
 145 
 146     path_element = vfs_path_get_by_index (vpath, -1);
 147     pname = vfs_path_clone (vpath);
 148     vfs_path_remove_element_by_index (pname, -1);
 149 
 150     w = path_element->class->which (path_element->class, path_element->vfs_prefix);
 151     if (w == -1)
 152         vfs_die ("This cannot happen... Hopefully.\n");
 153 
 154     if ((sfs_info[w].flags & F_1) == 0
 155         && strcmp (vfs_path_get_last_path_str (pname), PATH_SEP_STR) != 0)
 156     {
 157         vfs_path_free (pname, TRUE);
 158         return (-1);
 159     }
 160 
 161     /*    if ((sfs_info[w].flags & F_2) || (!inpath) || (!*inpath)); else return -1; */
 162     if ((sfs_info[w].flags & F_NOLOCALCOPY) != 0)
 163         pqname = name_quote (vfs_path_as_str (pname), FALSE);
 164     else
 165     {
 166         vfs_path_t *s;
 167 
 168         s = mc_getlocalcopy (pname);
 169         if (s == NULL)
 170         {
 171             vfs_path_free (pname, TRUE);
 172             return (-1);
 173         }
 174 
 175         pqname = name_quote (vfs_path_get_last_path_str (s), FALSE);
 176         vfs_path_free (s, TRUE);
 177     }
 178 
 179     vfs_path_free (pname, TRUE);
 180 
 181     for (s_iter = sfs_info[w].command; *s_iter != '\0'; s_iter++)
 182     {
 183         if (was_percent)
 184         {
 185             const char *ptr = NULL;
 186 
 187             was_percent = FALSE;
 188 
 189             switch (*s_iter)
 190             {
 191             case '1':
 192                 ptr = pqname;
 193                 break;
 194             case '2':
 195                 ptr = path_element->path;
 196                 break;
 197             case '3':
 198                 ptr = vfs_path_get_by_index (cache_vpath, -1)->path;
 199                 break;
 200             case '%':
 201                 COPY_CHAR;
 202                 continue;
 203             default:
 204                 break;
 205             }
 206 
 207             if (ptr != NULL)
 208             {
 209                 COPY_STRING (ptr);
 210             }
 211         }
 212         else if (*s_iter == '%')
 213             was_percent = TRUE;
 214         else
 215         {
 216             COPY_CHAR;
 217         }
 218     }
 219 
 220     g_free (pqname);
 221 
 222     /* don't read stdout */
 223     pip = mc_popen (pad, FALSE, TRUE, &error);
 224     if (pip == NULL)
 225     {
 226         message (D_ERROR, MSG_ERROR, _("SFS virtual file system:\n%s"), error->message);
 227         g_error_free (error);
 228         return (-1);
 229     }
 230 
 231     mc_pread (pip, &error);
 232     if (error != NULL)
 233     {
 234         message (D_ERROR, MSG_ERROR, _("SFS virtual file system:\n%s"), error->message);
 235         g_error_free (error);
 236         mc_pclose (pip, NULL);
 237         return (-1);
 238     }
 239 
 240     if (pip->err.len > 0)
 241         message (D_ERROR, MSG_ERROR, _("SFS virtual file system:\n%s"), pip->err.buf);
 242 
 243     mc_pclose (pip, NULL);
 244     return 0;                   /* OK */
 245 }
 246 
 247 /* --------------------------------------------------------------------------------------------- */
 248 
 249 static const char *
 250 sfs_redirect (const vfs_path_t * vpath)
     /*   */
 251 {
 252     GSList *cur;
 253     cachedfile *cf;
 254     vfs_path_t *cache_vpath;
 255     int handle;
 256     const vfs_path_element_t *path_element;
 257 
 258     path_element = vfs_path_get_by_index (vpath, -1);
 259     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 260 
 261     if (cur != NULL)
 262     {
 263         cf = (cachedfile *) cur->data;
 264         vfs_stamp (vfs_sfs_ops, cf);
 265         return cf->cache;
 266     }
 267 
 268     handle = vfs_mkstemps (&cache_vpath, "sfs", path_element->path);
 269 
 270     if (handle == -1)
 271         return "/SOMEONE_PLAYING_DIRTY_TMP_TRICKS_ON_US";
 272 
 273     close (handle);
 274 
 275     if (sfs_vfmake (vpath, cache_vpath) == 0)
 276     {
 277         cf = g_new (cachedfile, 1);
 278         cf->name = g_strdup (vfs_path_as_str (vpath));
 279         cf->cache = vfs_path_free (cache_vpath, FALSE);
 280         head = g_slist_prepend (head, cf);
 281 
 282         vfs_stamp_create (vfs_sfs_ops, (cachedfile *) head->data);
 283         return cf->cache;
 284     }
 285 
 286     mc_unlink (cache_vpath);
 287     vfs_path_free (cache_vpath, TRUE);
 288     return "/I_MUST_NOT_EXIST";
 289 }
 290 
 291 /* --------------------------------------------------------------------------------------------- */
 292 
 293 static void *
 294 sfs_open (const vfs_path_t * vpath /*struct vfs_class *me, const char *path */ , int flags,
     /*   */
 295           mode_t mode)
 296 {
 297     int *info;
 298     int fd;
 299 
 300     fd = open (sfs_redirect (vpath), NO_LINEAR (flags), mode);
 301     if (fd == -1)
 302         return NULL;
 303 
 304     info = g_new (int, 1);
 305     *info = fd;
 306 
 307     return info;
 308 }
 309 
 310 /* --------------------------------------------------------------------------------------------- */
 311 
 312 static int
 313 sfs_stat (const vfs_path_t * vpath, struct stat *buf)
     /*   */
 314 {
 315     return stat (sfs_redirect (vpath), buf);
 316 }
 317 
 318 /* --------------------------------------------------------------------------------------------- */
 319 
 320 static int
 321 sfs_lstat (const vfs_path_t * vpath, struct stat *buf)
     /*   */
 322 {
 323 #ifndef HAVE_STATLSTAT
 324     return lstat (sfs_redirect (vpath), buf);
 325 #else
 326     return statlstat (sfs_redirect (vpath), buf);
 327 #endif
 328 }
 329 
 330 /* --------------------------------------------------------------------------------------------- */
 331 
 332 static int
 333 sfs_chmod (const vfs_path_t * vpath, mode_t mode)
     /*   */
 334 {
 335     return chmod (sfs_redirect (vpath), mode);
 336 }
 337 
 338 /* --------------------------------------------------------------------------------------------- */
 339 
 340 static int
 341 sfs_chown (const vfs_path_t * vpath, uid_t owner, gid_t group)
     /*   */
 342 {
 343     return chown (sfs_redirect (vpath), owner, group);
 344 }
 345 
 346 /* --------------------------------------------------------------------------------------------- */
 347 
 348 static int
 349 sfs_utime (const vfs_path_t * vpath, mc_timesbuf_t * times)
     /*   */
 350 {
 351 #ifdef HAVE_UTIMENSAT
 352     return utimensat (AT_FDCWD, sfs_redirect (vpath), *times, 0);
 353 #else
 354     return utime (sfs_redirect (vpath), times);
 355 #endif
 356 }
 357 
 358 /* --------------------------------------------------------------------------------------------- */
 359 
 360 static int
 361 sfs_readlink (const vfs_path_t * vpath, char *buf, size_t size)
     /*   */
 362 {
 363     return readlink (sfs_redirect (vpath), buf, size);
 364 }
 365 
 366 /* --------------------------------------------------------------------------------------------- */
 367 
 368 static vfsid
 369 sfs_getid (const vfs_path_t * vpath)
     /*   */
 370 {
 371     GSList *cur;
 372 
 373     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 374 
 375     return (vfsid) (cur != NULL ? cur->data : NULL);
 376 }
 377 
 378 /* --------------------------------------------------------------------------------------------- */
 379 
 380 static void
 381 sfs_free (vfsid id)
     /*   */
 382 {
 383     struct cachedfile *which;
 384     GSList *cur;
 385 
 386     which = (struct cachedfile *) id;
 387     cur = g_slist_find (head, which);
 388     if (cur == NULL)
 389         vfs_die ("Free of thing which is unknown to me\n");
 390 
 391     which = (struct cachedfile *) cur->data;
 392     unlink (which->cache);
 393     g_free (which->cache);
 394     g_free (which->name);
 395     g_free (which);
 396 
 397     head = g_slist_delete_link (head, cur);
 398 }
 399 
 400 /* --------------------------------------------------------------------------------------------- */
 401 
 402 static void
 403 sfs_fill_names (struct vfs_class *me, fill_names_f func)
     /*   */
 404 {
 405     GSList *cur;
 406 
 407     (void) me;
 408 
 409     for (cur = head; cur != NULL; cur = g_slist_next (cur))
 410         func (((cachedfile *) cur->data)->name);
 411 }
 412 
 413 /* --------------------------------------------------------------------------------------------- */
 414 
 415 static gboolean
 416 sfs_nothingisopen (vfsid id)
     /*   */
 417 {
 418     /* FIXME: Investigate whether have to guard this like in
 419        the other VFSs (see fd_usage in extfs) -- Norbert */
 420     (void) id;
 421     return TRUE;
 422 }
 423 
 424 /* --------------------------------------------------------------------------------------------- */
 425 
 426 static vfs_path_t *
 427 sfs_getlocalcopy (const vfs_path_t * vpath)
     /*   */
 428 {
 429     return vfs_path_from_str (sfs_redirect (vpath));
 430 }
 431 
 432 /* --------------------------------------------------------------------------------------------- */
 433 
 434 static int
 435 sfs_ungetlocalcopy (const vfs_path_t * vpath, const vfs_path_t * local, gboolean has_changed)
     /*   */
 436 {
 437     (void) vpath;
 438     (void) local;
 439     (void) has_changed;
 440     return 0;
 441 }
 442 
 443 /* --------------------------------------------------------------------------------------------- */
 444 
 445 static int
 446 sfs_init (struct vfs_class *me)
     /*   */
 447 {
 448     char *mc_sfsini;
 449     FILE *cfg;
 450     char key[256];
 451 
 452     (void) me;
 453 
 454     mc_sfsini = g_build_filename (mc_global.sysconfig_dir, "sfs.ini", (char *) NULL);
 455     cfg = fopen (mc_sfsini, "r");
 456 
 457     if (cfg == NULL)
 458     {
 459         fprintf (stderr, _("%s: Warning: file %s not found\n"), "sfs_init()", mc_sfsini);
 460         g_free (mc_sfsini);
 461         return 0;
 462     }
 463     g_free (mc_sfsini);
 464 
 465     sfs_no = 0;
 466     while (sfs_no < MAXFS && fgets (key, sizeof (key), cfg) != NULL)
 467     {
 468         char *c, *semi = NULL;
 469         sfs_flags_t flags = F_NONE;
 470 
 471         if (*key == '#' || *key == '\n')
 472             continue;
 473 
 474         for (c = key; *c != '\0'; c++)
 475             if (*c == ':' || IS_PATH_SEP (*c))
 476             {
 477                 semi = c;
 478                 if (IS_PATH_SEP (*c))
 479                 {
 480                     *c = '\0';
 481                     flags |= F_FULLMATCH;
 482                 }
 483                 break;
 484             }
 485 
 486         if (semi == NULL)
 487         {
 488           invalid_line:
 489             fprintf (stderr, _("Warning: Invalid line in %s:\n%s\n"), "sfs.ini", key);
 490             continue;
 491         }
 492 
 493         for (c = semi + 1; *c != '\0' && !whitespace (*c); c++)
 494             switch (*c)
 495             {
 496             case '1':
 497                 flags |= F_1;
 498                 break;
 499             case '2':
 500                 flags |= F_2;
 501                 break;
 502             case 'R':
 503                 flags |= F_NOLOCALCOPY;
 504                 break;
 505             default:
 506                 fprintf (stderr, _("Warning: Invalid flag %c in %s:\n%s\n"), *c, "sfs.ini", key);
 507             }
 508 
 509         if (*c == '\0')
 510             goto invalid_line;
 511 
 512         c++;
 513         *(semi + 1) = '\0';
 514         semi = strchr (c, '\n');
 515         if (semi != NULL)
 516             *semi = '\0';
 517 
 518         sfs_info[sfs_no].prefix = g_strdup (key);
 519         sfs_info[sfs_no].command = g_strdup (c);
 520         sfs_info[sfs_no].flags = flags;
 521         sfs_no++;
 522     }
 523     fclose (cfg);
 524 
 525     return 1;
 526 }
 527 
 528 /* --------------------------------------------------------------------------------------------- */
 529 
 530 static void
 531 sfs_done (struct vfs_class *me)
     /*   */
 532 {
 533     int i;
 534 
 535     (void) me;
 536 
 537     for (i = 0; i < sfs_no; i++)
 538     {
 539         MC_PTR_FREE (sfs_info[i].prefix);
 540         MC_PTR_FREE (sfs_info[i].command);
 541     }
 542     sfs_no = 0;
 543 }
 544 
 545 /* --------------------------------------------------------------------------------------------- */
 546 
 547 static int
 548 sfs_which (struct vfs_class *me, const char *path)
     /*   */
 549 {
 550     int i;
 551 
 552     (void) me;
 553 
 554     for (i = 0; i < sfs_no; i++)
 555         if ((sfs_info[i].flags & F_FULLMATCH) != 0)
 556         {
 557             if (strcmp (path, sfs_info[i].prefix) == 0)
 558                 return i;
 559         }
 560         else if (strncmp (path, sfs_info[i].prefix, strlen (sfs_info[i].prefix)) == 0)
 561             return i;
 562 
 563     return (-1);
 564 }
 565 
 566 /* --------------------------------------------------------------------------------------------- */
 567 /*** public functions ****************************************************************************/
 568 /* --------------------------------------------------------------------------------------------- */
 569 
 570 void
 571 vfs_init_sfs (void)
     /*   */
 572 {
 573     /* NULLize vfs_s_subclass members */
 574     memset (&sfs_subclass, 0, sizeof (sfs_subclass));
 575 
 576     vfs_init_class (vfs_sfs_ops, "sfs", VFSF_UNKNOWN, NULL);
 577     vfs_sfs_ops->init = sfs_init;
 578     vfs_sfs_ops->done = sfs_done;
 579     vfs_sfs_ops->fill_names = sfs_fill_names;
 580     vfs_sfs_ops->which = sfs_which;
 581     vfs_sfs_ops->open = sfs_open;
 582     vfs_sfs_ops->close = local_close;
 583     vfs_sfs_ops->read = local_read;
 584     vfs_sfs_ops->stat = sfs_stat;
 585     vfs_sfs_ops->lstat = sfs_lstat;
 586     vfs_sfs_ops->fstat = local_fstat;
 587     vfs_sfs_ops->chmod = sfs_chmod;
 588     vfs_sfs_ops->chown = sfs_chown;
 589     vfs_sfs_ops->utime = sfs_utime;
 590     vfs_sfs_ops->readlink = sfs_readlink;
 591     vfs_sfs_ops->ferrno = local_errno;
 592     vfs_sfs_ops->lseek = local_lseek;
 593     vfs_sfs_ops->getid = sfs_getid;
 594     vfs_sfs_ops->nothingisopen = sfs_nothingisopen;
 595     vfs_sfs_ops->free = sfs_free;
 596     vfs_sfs_ops->getlocalcopy = sfs_getlocalcopy;
 597     vfs_sfs_ops->ungetlocalcopy = sfs_ungetlocalcopy;
 598     vfs_register_class (vfs_sfs_ops);
 599 }
 600 
 601 /* --------------------------------------------------------------------------------------------- */

/*   */