src/vfs/sfs/sfs.c

   1 /*
   2    Single File fileSystem
   3
   4    Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   5    2011, 2013
   6    The Free Software Foundation, Inc.
   7
   8    Written by:
   9    Slava Zanko <slavazanko@gmail.com>, 2013
  10
  11    This file is part of the Midnight Commander.
  12
  13    The Midnight Commander is free software: you can redistribute it
  14    and/or modify it under the terms of the GNU General Public License as
  15    published by the Free Software Foundation, either version 3 of the License,
  16    or (at your option) any later version.
  17
  18    The Midnight Commander is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25  */
  26
  27 /**
  28  * \file
  29  * \brief Source: Single File fileSystem
  30  *
  31  * This defines whole class of filesystems which contain single file
  32  * inside. It is somehow similar to extfs, except that extfs makes
  33  * whole virtual trees and we do only single virtual files.
  34  *
  35  * If you want to gunzip something, you should open it with \verbatim #ugz \endverbatim
  36  * suffix, DON'T try to gunzip it yourself.
  37  *
  38  * Namespace: exports vfs_sfs_ops
  39  */
  40
  41 #include <config.h>
  42 #include <errno.h>
  43 #include <sys/types.h>
  44 #include <unistd.h>
  45 #include <stdio.h>
  46 #include <string.h>
  47 #include <fcntl.h>
  48
  49 #include "lib/global.h"
  50 #include "lib/util.h"
  51 #include "lib/widget.h"         /* D_ERROR, D_NORMAL */
  52
  53 #include "src/execute.h"        /* EXECUTE_AS_SHELL */
  54
  55 #include "lib/vfs/vfs.h"
  56 #include "lib/vfs/utilvfs.h"
  57 #include "src/vfs/local/local.h"
  58 #include "lib/vfs/gc.h"         /* vfs_stamp_create */
  59
  60 #include "sfs.h"
  61
  62 /*** global variables ****************************************************************************/
  63
  64 /*** file scope macro definitions ****************************************************************/
  65
  66 #define MAXFS 32
  67
  68 #define F_1 1
  69 #define F_2 2
  70 #define F_NOLOCALCOPY 4
  71 #define F_FULLMATCH 8
  72
  73 #define COPY_CHAR \
  74     if ((size_t) (t - pad) > sizeof(pad)) \
  75     { \
  76         g_free (pqname); \
  77         return -1; \
  78     } \
  79     else \
  80         *t++ = *s_iter;
  81
  82 #define COPY_STRING(a) \
  83     if ((t - pad) + strlen(a) > sizeof(pad)) \
  84     { \
  85         g_free (pqname); \
  86         return -1; \
  87     } \
  88     else \
  89     { \
  90         strcpy (t, a); \
  91         t += strlen (a); \
  92     }
  93
  94 /*** file scope type declarations ****************************************************************/
  95
  96 typedef struct cachedfile
  97 {
  98     char *name;
  99     char *cache;
 100 } cachedfile;
 101
 102 /*** file scope variables ************************************************************************/
 103
 104 static GSList *head;
 105 static struct vfs_class vfs_sfs_ops;
 106
 107 static int sfs_no = 0;
 108 static char *sfs_prefix[MAXFS];
 109 static char *sfs_command[MAXFS];
 110 static int sfs_flags[MAXFS];
 111
 112 /*** file scope functions ************************************************************************/
 113
 114 static int
 115 cachedfile_compare (const void *a, const void *b)
 116 {
 117     const cachedfile *cf = (const cachedfile *) a;
 118     const char *name = (const char *) b;
 119
 120     return strcmp (name, cf->name);
 121 }
 122
 123 /* --------------------------------------------------------------------------------------------- */
 124
 125 static int
 126 sfs_vfmake (const vfs_path_t * vpath, vfs_path_t * cache_vpath)
 127 {
 128     int w;
 129     char pad[10240];
 130     char *s_iter, *t = pad;
 131     int was_percent = 0;
 132     vfs_path_t *pname;          /* name of parent archive */
 133     char *pqname;               /* name of parent archive, quoted */
 134     const vfs_path_element_t *path_element;
 135
 136     path_element = vfs_path_get_by_index (vpath, -1);
 137     pname = vfs_path_clone (vpath);
 138     vfs_path_remove_element_by_index (pname, -1);
 139
 140     w = (*path_element->class->which) (path_element->class, path_element->vfs_prefix);
 141     if (w == -1)
 142         vfs_die ("This cannot happen... Hopefully.\n");
 143
 144     if ((sfs_flags[w] & F_1) == 0 && strcmp (vfs_path_get_last_path_str (pname), PATH_SEP_STR) != 0)
 145     {
 146         vfs_path_free (pname);
 147         return -1;
 148     }
 149
 150     /*    if ((sfs_flags[w] & F_2) || (!inpath) || (!*inpath)); else return -1; */
 151     if ((sfs_flags[w] & F_NOLOCALCOPY) == 0)
 152     {
 153         vfs_path_t *s;
 154
 155         s = mc_getlocalcopy (pname);
 156         if (s == NULL)
 157         {
 158             vfs_path_free (pname);
 159             return -1;
 160         }
 161         pqname = name_quote (vfs_path_get_last_path_str (s), 0);
 162         vfs_path_free (s);
 163     }
 164     else
 165         pqname = name_quote (vfs_path_as_str (pname), 0);
 166
 167     vfs_path_free (pname);
 168
 169
 170     for (s_iter = sfs_command[w]; *s_iter != '\0'; s_iter++)
 171     {
 172         if (was_percent)
 173         {
 174             const char *ptr = NULL;
 175
 176             was_percent = 0;
 177
 178             switch (*s_iter)
 179             {
 180             case '1':
 181                 ptr = pqname;
 182                 break;
 183             case '2':
 184                 ptr = path_element->path;
 185                 break;
 186             case '3':
 187                 ptr = vfs_path_get_by_index (cache_vpath, -1)->path;
 188                 break;
 189             case '%':
 190                 COPY_CHAR;
 191                 continue;
 192             }
 193             if (ptr != NULL)
 194             {
 195                 COPY_STRING (ptr);
 196             }
 197         }
 198         else
 199         {
 200             if (*s_iter == '%')
 201                 was_percent = 1;
 202             else
 203                 COPY_CHAR;
 204         }
 205     }
 206
 207     g_free (pqname);
 208     open_error_pipe ();
 209     if (my_system (EXECUTE_AS_SHELL, "/bin/sh", pad))
 210     {
 211         close_error_pipe (D_ERROR, NULL);
 212         return -1;
 213     }
 214
 215     close_error_pipe (D_NORMAL, NULL);
 216     return 0;                   /* OK */
 217 }
 218
 219 /* --------------------------------------------------------------------------------------------- */
 220
 221 static const char *
 222 sfs_redirect (const vfs_path_t * vpath)
 223 {
 224     GSList *cur;
 225     cachedfile *cf;
 226     vfs_path_t *cache_vpath;
 227     int handle;
 228     const vfs_path_element_t *path_element;
 229
 230     path_element = vfs_path_get_by_index (vpath, -1);
 231     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 232
 233     if (cur != NULL)
 234     {
 235         cf = (cachedfile *) cur->data;
 236         vfs_stamp (&vfs_sfs_ops, cf);
 237         return cf->cache;
 238     }
 239
 240     handle = vfs_mkstemps (&cache_vpath, "sfs", path_element->path);
 241
 242     if (handle == -1)
 243         return "/SOMEONE_PLAYING_DIRTY_TMP_TRICKS_ON_US";
 244
 245     close (handle);
 246
 247     if (sfs_vfmake (vpath, cache_vpath) == 0)
 248     {
 249         cf = g_new (cachedfile, 1);
 250         cf->name = g_strdup (vfs_path_as_str (vpath));
 251         cf->cache = g_strdup (vfs_path_as_str (cache_vpath));
 252         head = g_slist_prepend (head, cf);
 253         vfs_path_free (cache_vpath);
 254
 255         vfs_stamp_create (&vfs_sfs_ops, (cachedfile *) head->data);
 256         return cf->cache;
 257     }
 258
 259     mc_unlink (cache_vpath);
 260     vfs_path_free (cache_vpath);
 261     return "/I_MUST_NOT_EXIST";
 262 }
 263
 264 /* --------------------------------------------------------------------------------------------- */
 265
 266 static void *
 267 sfs_open (const vfs_path_t * vpath /*struct vfs_class *me, const char *path */ , int flags,
 268           mode_t mode)
 269 {
 270     int *sfs_info;
 271     int fd;
 272
 273     fd = open (sfs_redirect (vpath), NO_LINEAR (flags), mode);
 274     if (fd == -1)
 275         return 0;
 276
 277     sfs_info = g_new (int, 1);
 278     *sfs_info = fd;
 279
 280     return sfs_info;
 281 }
 282
 283 /* --------------------------------------------------------------------------------------------- */
 284
 285 static int
 286 sfs_stat (const vfs_path_t * vpath, struct stat *buf)
 287 {
 288     return stat (sfs_redirect (vpath), buf);
 289 }
 290
 291 /* --------------------------------------------------------------------------------------------- */
 292
 293 static int
 294 sfs_lstat (const vfs_path_t * vpath, struct stat *buf)
 295 {
 296 #ifndef HAVE_STATLSTAT
 297     return lstat (sfs_redirect (vpath), buf);
 298 #else
 299     return statlstat (sfs_redirect (vpath), buf);
 300 #endif
 301 }
 302
 303 /* --------------------------------------------------------------------------------------------- */
 304
 305 static int
 306 sfs_chmod (const vfs_path_t * vpath, mode_t mode)
 307 {
 308     return chmod (sfs_redirect (vpath), mode);
 309 }
 310
 311 /* --------------------------------------------------------------------------------------------- */
 312
 313 static int
 314 sfs_chown (const vfs_path_t * vpath, uid_t owner, gid_t group)
 315 {
 316     return chown (sfs_redirect (vpath), owner, group);
 317 }
 318
 319 /* --------------------------------------------------------------------------------------------- */
 320
 321 static int
 322 sfs_utime (const vfs_path_t * vpath, struct utimbuf *times)
 323 {
 324     return utime (sfs_redirect (vpath), times);
 325 }
 326
 327 /* --------------------------------------------------------------------------------------------- */
 328
 329 static int
 330 sfs_readlink (const vfs_path_t * vpath, char *buf, size_t size)
 331 {
 332     return readlink (sfs_redirect (vpath), buf, size);
 333 }
 334
 335 /* --------------------------------------------------------------------------------------------- */
 336
 337 static vfsid
 338 sfs_getid (const vfs_path_t * vpath)
 339 {
 340     GSList *cur;
 341
 342     cur = g_slist_find_custom (head, vfs_path_as_str (vpath), cachedfile_compare);
 343
 344     return (vfsid) (cur != NULL ? cur->data : NULL);
 345 }
 346
 347 /* --------------------------------------------------------------------------------------------- */
 348
 349 static void
 350 sfs_free (vfsid id)
 351 {
 352     struct cachedfile *which;
 353     GSList *cur;
 354
 355     which = (struct cachedfile *) id;
 356     cur = g_slist_find (head, which);
 357     if (cur == NULL)
 358         vfs_die ("Free of thing which is unknown to me\n");
 359
 360     which = (struct cachedfile *) cur->data;
 361     unlink (which->cache);
 362     g_free (which->cache);
 363     g_free (which->name);
 364     g_free (which);
 365
 366     head = g_slist_delete_link (head, cur);
 367 }
 368
 369 /* --------------------------------------------------------------------------------------------- */
 370
 371 static void
 372 sfs_fill_names (struct vfs_class *me, fill_names_f func)
 373 {
 374     GSList *cur;
 375
 376     (void) me;
 377
 378     for (cur = head; cur != NULL; cur = g_slist_next (cur))
 379         func (((cachedfile *) cur->data)->name);
 380 }
 381
 382 /* --------------------------------------------------------------------------------------------- */
 383
 384 static int
 385 sfs_nothingisopen (vfsid id)
 386 {
 387     /* FIXME: Investigate whether have to guard this like in
 388        the other VFSs (see fd_usage in extfs) -- Norbert */
 389     (void) id;
 390     return 1;
 391 }
 392
 393 /* --------------------------------------------------------------------------------------------- */
 394
 395 static vfs_path_t *
 396 sfs_getlocalcopy (const vfs_path_t * vpath)
 397 {
 398     return vfs_path_from_str (sfs_redirect (vpath));
 399 }
 400
 401 /* --------------------------------------------------------------------------------------------- */
 402
 403 static int
 404 sfs_ungetlocalcopy (const vfs_path_t * vpath, const vfs_path_t * local, gboolean has_changed)
 405 {
 406     (void) vpath;
 407     (void) local;
 408     (void) has_changed;
 409     return 0;
 410 }
 411
 412 /* --------------------------------------------------------------------------------------------- */
 413
 414 static int
 415 sfs_init (struct vfs_class *me)
 416 {
 417     char *mc_sfsini;
 418     FILE *cfg;
 419     char key[256];
 420
 421     (void) me;
 422
 423     mc_sfsini = g_build_filename (mc_global.sysconfig_dir, "sfs.ini", (char *) NULL);
 424     cfg = fopen (mc_sfsini, "r");
 425
 426     if (cfg == NULL)
 427     {
 428         fprintf (stderr, _("%s: Warning: file %s not found\n"), "sfs_init()", mc_sfsini);
 429         g_free (mc_sfsini);
 430         return 0;
 431     }
 432     g_free (mc_sfsini);
 433
 434     sfs_no = 0;
 435     while (sfs_no < MAXFS && fgets (key, sizeof (key), cfg))
 436     {
 437         char *c, *semi = NULL, flags = 0;
 438
 439         if (*key == '#' || *key == '\n')
 440             continue;
 441
 442         for (c = key; *c; c++)
 443             if ((*c == ':') || (*c == '/'))
 444             {
 445                 semi = c;
 446                 if (*c == '/')
 447                 {
 448                     *c = 0;
 449                     flags |= F_FULLMATCH;
 450                 }
 451                 break;
 452             }
 453
 454         if (!semi)
 455         {
 456           invalid_line:
 457             fprintf (stderr, _("Warning: Invalid line in %s:\n%s\n"), "sfs.ini", key);
 458             continue;
 459         }
 460
 461         c = semi + 1;
 462         while (*c && (*c != ' ') && (*c != '\t'))
 463         {
 464             switch (*c)
 465             {
 466             case '1':
 467                 flags |= F_1;
 468                 break;
 469             case '2':
 470                 flags |= F_2;
 471                 break;
 472             case 'R':
 473                 flags |= F_NOLOCALCOPY;
 474                 break;
 475             default:
 476                 fprintf (stderr, _("Warning: Invalid flag %c in %s:\n%s\n"), *c, "sfs.ini", key);
 477             }
 478             c++;
 479         }
 480         if (!*c)
 481             goto invalid_line;
 482
 483         c++;
 484         *(semi + 1) = 0;
 485         semi = strchr (c, '\n');
 486         if (semi != NULL)
 487             *semi = 0;
 488
 489         sfs_prefix[sfs_no] = g_strdup (key);
 490         sfs_command[sfs_no] = g_strdup (c);
 491         sfs_flags[sfs_no] = flags;
 492         sfs_no++;
 493     }
 494     fclose (cfg);
 495     return 1;
 496 }
 497
 498 /* --------------------------------------------------------------------------------------------- */
 499
 500 static void
 501 sfs_done (struct vfs_class *me)
 502 {
 503     int i;
 504
 505     (void) me;
 506
 507     for (i = 0; i < sfs_no; i++)
 508     {
 509         g_free (sfs_prefix[i]);
 510         g_free (sfs_command[i]);
 511         sfs_prefix[i] = sfs_command[i] = NULL;
 512     }
 513     sfs_no = 0;
 514 }
 515
 516 /* --------------------------------------------------------------------------------------------- */
 517
 518 static int
 519 sfs_which (struct vfs_class *me, const char *path)
 520 {
 521     int i;
 522
 523     (void) me;
 524
 525     for (i = 0; i < sfs_no; i++)
 526         if (sfs_flags[i] & F_FULLMATCH)
 527         {
 528             if (!strcmp (path, sfs_prefix[i]))
 529                 return i;
 530         }
 531         else if (!strncmp (path, sfs_prefix[i], strlen (sfs_prefix[i])))
 532             return i;
 533
 534     return -1;
 535 }
 536
 537 /* --------------------------------------------------------------------------------------------- */
 538 /*** public functions ****************************************************************************/
 539 /* --------------------------------------------------------------------------------------------- */
 540
 541 void
 542 init_sfs (void)
 543 {
 544     vfs_sfs_ops.name = "sfs";
 545     vfs_sfs_ops.init = sfs_init;
 546     vfs_sfs_ops.done = sfs_done;
 547     vfs_sfs_ops.fill_names = sfs_fill_names;
 548     vfs_sfs_ops.which = sfs_which;
 549     vfs_sfs_ops.open = sfs_open;
 550     vfs_sfs_ops.close = local_close;
 551     vfs_sfs_ops.read = local_read;
 552     vfs_sfs_ops.stat = sfs_stat;
 553     vfs_sfs_ops.lstat = sfs_lstat;
 554     vfs_sfs_ops.fstat = local_fstat;
 555     vfs_sfs_ops.chmod = sfs_chmod;
 556     vfs_sfs_ops.chown = sfs_chown;
 557     vfs_sfs_ops.utime = sfs_utime;
 558     vfs_sfs_ops.readlink = sfs_readlink;
 559     vfs_sfs_ops.ferrno = local_errno;
 560     vfs_sfs_ops.lseek = local_lseek;
 561     vfs_sfs_ops.getid = sfs_getid;
 562     vfs_sfs_ops.nothingisopen = sfs_nothingisopen;
 563     vfs_sfs_ops.free = sfs_free;
 564     vfs_sfs_ops.getlocalcopy = sfs_getlocalcopy;
 565     vfs_sfs_ops.ungetlocalcopy = sfs_ungetlocalcopy;
 566     vfs_register_class (&vfs_sfs_ops);
 567 }
 568
 569 /* --------------------------------------------------------------------------------------------- */