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
   6    The Free Software Foundation, Inc.
   7
   8    This file is part of the Midnight Commander.
   9
  10    The Midnight Commander is free software: you can redistribute it
  11    and/or modify it under the terms of the GNU General Public License as
  12    published by the Free Software Foundation, either version 3 of the License,
  13    or (at your option) any later version.
  14
  15    The Midnight Commander is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 /**
  25  * \file
  26  * \brief Source: Single File fileSystem
  27  *
  28  * This defines whole class of filesystems which contain single file
  29  * inside. It is somehow similar to extfs, except that extfs makes
  30  * whole virtual trees and we do only single virtual files.
  31  *
  32  * If you want to gunzip something, you should open it with \verbatim #ugz \endverbatim
  33  * suffix, DON'T try to gunzip it yourself.
  34  *
  35  * Namespace: exports vfs_sfs_ops
  36  */
  37
  38 #include <config.h>
  39 #include <errno.h>
  40 #include <sys/types.h>
  41 #include <unistd.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <fcntl.h>
  45
  46 #include "lib/global.h"
  47 #include "lib/util.h"
  48 #include "lib/widget.h"         /* D_ERROR, D_NORMAL */
  49
  50 #include "src/execute.h"        /* EXECUTE_AS_SHELL */
  51
  52 #include "lib/vfs/vfs.h"
  53 #include "lib/vfs/utilvfs.h"
  54 #include "src/vfs/local/local.h"
  55 #include "lib/vfs/gc.h"         /* vfs_stamp_create */
  56
  57 #include "sfs.h"
  58
  59 /*** global variables ****************************************************************************/
  60
  61 /*** file scope macro definitions ****************************************************************/
  62
  63 #define MAXFS 32
  64
  65 #define F_1 1
  66 #define F_2 2
  67 #define F_NOLOCALCOPY 4
  68 #define F_FULLMATCH 8
  69
  70 #define COPY_CHAR \
  71     if ((size_t) (t - pad) > sizeof(pad)) \
  72     { \
  73         g_free (pqname); \
  74         return -1; \
  75     } \
  76     else \
  77         *t++ = *s_iter;
  78
  79 #define COPY_STRING(a) \
  80     if ((t - pad) + strlen(a) > sizeof(pad)) \
  81     { \
  82         g_free (pqname); \
  83         return -1; \
  84     } \
  85     else \
  86     { \
  87         strcpy (t, a); \
  88         t += strlen (a); \
  89     }
  90
  91 /*** file scope type declarations ****************************************************************/
  92
  93 typedef struct cachedfile
  94 {
  95     char *name;
  96     char *cache;
  97 } cachedfile;
  98
  99 /*** file scope variables ************************************************************************/
 100
 101 static GSList *head;
 102 static struct vfs_class vfs_sfs_ops;
 103
 104 static int sfs_no = 0;
 105 static char *sfs_prefix[MAXFS];
 106 static char *sfs_command[MAXFS];
 107 static int sfs_flags[MAXFS];
 108
 109 /*** file scope functions ************************************************************************/
 110
 111 static int
 112 cachedfile_compare (const void *a, const void *b)
 113 {
 114     const cachedfile *cf = (const cachedfile *) a;
 115     const char *name = (const char *) b;
 116
 117     return strcmp (name, cf->name);
 118 }
 119
 120 /* --------------------------------------------------------------------------------------------- */
 121
 122 static int
 123 sfs_vfmake (const vfs_path_t * vpath, vfs_path_t * cache_vpath)
 124 {
 125     int w;
 126     char pad[10240];
 127     char *s_iter, *t = pad;
 128     int was_percent = 0;
 129     vfs_path_t *pname, *s;      /* name of parent archive */
 130     char *pqname;               /* name of parent archive, quoted */
 131     const vfs_path_element_t *path_element;
 132
 133     path_element = vfs_path_get_by_index (vpath, -1);
 134     pname = vfs_path_clone (vpath);
 135     vfs_path_remove_element_by_index (pname, -1);
 136
 137     w = (*path_element->class->which) (path_element->class, path_element->vfs_prefix);
 138     if (w == -1)
 139         vfs_die ("This cannot happen... Hopefully.\n");
 140
 141     if ((sfs_flags[w] & F_1) == 0 && strcmp (vfs_path_get_last_path_str (pname), PATH_SEP_STR) != 0)
 142     {
 143         vfs_path_free (pname);
 144         return -1;
 145     }
 146
 147     /*    if ((sfs_flags[w] & F_2) || (!inpath) || (!*inpath)); else return -1; */
 148     if ((sfs_flags[w] & F_NOLOCALCOPY) == 0)
 149     {
 150         s = mc_getlocalcopy (pname);
 151         if (s == NULL)
 152         {
 153             vfs_path_free (pname);
 154             return -1;
 155         }
 156         pqname = name_quote (vfs_path_get_last_path_str (s), 0);
 157         vfs_path_free (s);
 158     }
 159     else
 160     {
 161         char *pname_str;
 162
 163         pname_str = vfs_path_to_str (pname);
 164         pqname = name_quote (pname_str, 0);
 165         g_free (pname_str);
 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             COPY_STRING (ptr);
 194         }
 195         else
 196         {
 197             if (*s_iter == '%')
 198                 was_percent = 1;
 199             else
 200                 COPY_CHAR;
 201         }
 202     }
 203
 204     g_free (pqname);
 205     open_error_pipe ();
 206     if (my_system (EXECUTE_AS_SHELL, "/bin/sh", pad))
 207     {
 208         close_error_pipe (D_ERROR, NULL);
 209         return -1;
 210     }
 211
 212     close_error_pipe (D_NORMAL, NULL);
 213     return 0;                   /* OK */
 214 }
 215
 216 /* --------------------------------------------------------------------------------------------- */
 217
 218 static const char *
 219 sfs_redirect (const vfs_path_t * vpath)
 220 {
 221     GSList *cur;
 222     cachedfile *cf;
 223     vfs_path_t *cache_vpath;
 224     int handle;
 225     const vfs_path_element_t *path_element;
 226     char *path;
 227
 228     path = vfs_path_to_str (vpath);
 229     path_element = vfs_path_get_by_index (vpath, -1);
 230     cur = g_slist_find_custom (head, path, cachedfile_compare);
 231     g_free (path);
 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 = vfs_path_to_str (vpath);
 251         cf->cache = vfs_path_to_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     char *path = vfs_path_to_str (vpath);
 342
 343     cur = g_slist_find_custom (head, path, cachedfile_compare);
 344     g_free (path);
 345
 346     return (vfsid) (cur != NULL ? cur->data : NULL);
 347 }
 348
 349 /* --------------------------------------------------------------------------------------------- */
 350
 351 static void
 352 sfs_free (vfsid id)
 353 {
 354     struct cachedfile *which;
 355     GSList *cur;
 356
 357     which = (struct cachedfile *) id;
 358     cur = g_slist_find (head, which);
 359     if (cur == NULL)
 360         vfs_die ("Free of thing which is unknown to me\n");
 361
 362     which = (struct cachedfile *) cur->data;
 363     unlink (which->cache);
 364     g_free (which->cache);
 365     g_free (which->name);
 366     g_free (which);
 367
 368     head = g_slist_delete_link (head, cur);
 369 }
 370
 371 /* --------------------------------------------------------------------------------------------- */
 372
 373 static void
 374 sfs_fill_names (struct vfs_class *me, fill_names_f func)
 375 {
 376     GSList *cur;
 377
 378     (void) me;
 379
 380     for (cur = head; cur != NULL; cur = g_slist_next (cur))
 381         func (((cachedfile *) cur->data)->name);
 382 }
 383
 384 /* --------------------------------------------------------------------------------------------- */
 385
 386 static int
 387 sfs_nothingisopen (vfsid id)
 388 {
 389     /* FIXME: Investigate whether have to guard this like in
 390        the other VFSs (see fd_usage in extfs) -- Norbert */
 391     (void) id;
 392     return 1;
 393 }
 394
 395 /* --------------------------------------------------------------------------------------------- */
 396
 397 static vfs_path_t *
 398 sfs_getlocalcopy (const vfs_path_t * vpath)
 399 {
 400     return vfs_path_from_str (sfs_redirect (vpath));
 401 }
 402
 403 /* --------------------------------------------------------------------------------------------- */
 404
 405 static int
 406 sfs_ungetlocalcopy (const vfs_path_t * vpath, const vfs_path_t * local, gboolean has_changed)
 407 {
 408     (void) vpath;
 409     (void) local;
 410     (void) has_changed;
 411     return 0;
 412 }
 413
 414 /* --------------------------------------------------------------------------------------------- */
 415
 416 static int
 417 sfs_init (struct vfs_class *me)
 418 {
 419     char *mc_sfsini;
 420     FILE *cfg;
 421     char key[256];
 422
 423     (void) me;
 424
 425     mc_sfsini = g_build_filename (mc_global.sysconfig_dir, "sfs.ini", (char *) NULL);
 426     cfg = fopen (mc_sfsini, "r");
 427
 428     if (cfg == NULL)
 429     {
 430         fprintf (stderr, _("%s: Warning: file %s not found\n"), "sfs_init()", mc_sfsini);
 431         g_free (mc_sfsini);
 432         return 0;
 433     }
 434     g_free (mc_sfsini);
 435
 436     sfs_no = 0;
 437     while (sfs_no < MAXFS && fgets (key, sizeof (key), cfg))
 438     {
 439         char *c, *semi = NULL, flags = 0;
 440
 441         if (*key == '#' || *key == '\n')
 442             continue;
 443
 444         for (c = key; *c; c++)
 445             if ((*c == ':') || (*c == '/'))
 446             {
 447                 semi = c;
 448                 if (*c == '/')
 449                 {
 450                     *c = 0;
 451                     flags |= F_FULLMATCH;
 452                 }
 453                 break;
 454             }
 455
 456         if (!semi)
 457         {
 458           invalid_line:
 459             fprintf (stderr, _("Warning: Invalid line in %s:\n%s\n"), "sfs.ini", key);
 460             continue;
 461         }
 462
 463         c = semi + 1;
 464         while (*c && (*c != ' ') && (*c != '\t'))
 465         {
 466             switch (*c)
 467             {
 468             case '1':
 469                 flags |= F_1;
 470                 break;
 471             case '2':
 472                 flags |= F_2;
 473                 break;
 474             case 'R':
 475                 flags |= F_NOLOCALCOPY;
 476                 break;
 477             default:
 478                 fprintf (stderr, _("Warning: Invalid flag %c in %s:\n%s\n"), *c, "sfs.ini", key);
 479             }
 480             c++;
 481         }
 482         if (!*c)
 483             goto invalid_line;
 484
 485         c++;
 486         *(semi + 1) = 0;
 487         semi = strchr (c, '\n');
 488         if (semi != NULL)
 489             *semi = 0;
 490
 491         sfs_prefix[sfs_no] = g_strdup (key);
 492         sfs_command[sfs_no] = g_strdup (c);
 493         sfs_flags[sfs_no] = flags;
 494         sfs_no++;
 495     }
 496     fclose (cfg);
 497     return 1;
 498 }
 499
 500 /* --------------------------------------------------------------------------------------------- */
 501
 502 static void
 503 sfs_done (struct vfs_class *me)
 504 {
 505     int i;
 506
 507     (void) me;
 508
 509     for (i = 0; i < sfs_no; i++)
 510     {
 511         g_free (sfs_prefix[i]);
 512         g_free (sfs_command[i]);
 513         sfs_prefix[i] = sfs_command[i] = NULL;
 514     }
 515     sfs_no = 0;
 516 }
 517
 518 /* --------------------------------------------------------------------------------------------- */
 519
 520 static int
 521 sfs_which (struct vfs_class *me, const char *path)
 522 {
 523     int i;
 524
 525     (void) me;
 526
 527     for (i = 0; i < sfs_no; i++)
 528         if (sfs_flags[i] & F_FULLMATCH)
 529         {
 530             if (!strcmp (path, sfs_prefix[i]))
 531                 return i;
 532         }
 533         else if (!strncmp (path, sfs_prefix[i], strlen (sfs_prefix[i])))
 534             return i;
 535
 536     return -1;
 537 }
 538
 539 /* --------------------------------------------------------------------------------------------- */
 540 /*** public functions ****************************************************************************/
 541 /* --------------------------------------------------------------------------------------------- */
 542
 543 void
 544 init_sfs (void)
 545 {
 546     vfs_sfs_ops.name = "sfs";
 547     vfs_sfs_ops.init = sfs_init;
 548     vfs_sfs_ops.done = sfs_done;
 549     vfs_sfs_ops.fill_names = sfs_fill_names;
 550     vfs_sfs_ops.which = sfs_which;
 551     vfs_sfs_ops.open = sfs_open;
 552     vfs_sfs_ops.close = local_close;
 553     vfs_sfs_ops.read = local_read;
 554     vfs_sfs_ops.stat = sfs_stat;
 555     vfs_sfs_ops.lstat = sfs_lstat;
 556     vfs_sfs_ops.fstat = local_fstat;
 557     vfs_sfs_ops.chmod = sfs_chmod;
 558     vfs_sfs_ops.chown = sfs_chown;
 559     vfs_sfs_ops.utime = sfs_utime;
 560     vfs_sfs_ops.readlink = sfs_readlink;
 561     vfs_sfs_ops.ferrno = local_errno;
 562     vfs_sfs_ops.lseek = local_lseek;
 563     vfs_sfs_ops.getid = sfs_getid;
 564     vfs_sfs_ops.nothingisopen = sfs_nothingisopen;
 565     vfs_sfs_ops.free = sfs_free;
 566     vfs_sfs_ops.getlocalcopy = sfs_getlocalcopy;
 567     vfs_sfs_ops.ungetlocalcopy = sfs_ungetlocalcopy;
 568     vfs_register_class (&vfs_sfs_ops);
 569 }
 570
 571 /* --------------------------------------------------------------------------------------------- */