vfs/sfs.c

   1 /*
   2  * Single File fileSystem
   3  *
   4  * Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   5  * Free Software Foundation, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 /**
  23  * \file
  24  * \brief Source: Single File fileSystem
  25  *
  26  * This defines whole class of filesystems which contain single file
  27  * inside. It is somehow similar to extfs, except that extfs makes
  28  * whole virtual trees and we do only single virtual files.
  29  *
  30  * If you want to gunzip something, you should open it with #ugz
  31  * suffix, DON'T try to gunzip it yourself.
  32  *
  33  * Namespace: exports vfs_sfs_ops
  34  */
  35
  36 #include <config.h>
  37 #include <errno.h>
  38 #include <sys/types.h>
  39 #include <unistd.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <fcntl.h>
  43
  44 #include "../src/global.h"
  45
  46 #include "../src/wtools.h"      /* message() */
  47 #include "../src/main.h"        /* print_vfs_message */
  48 #include "../src/execute.h"     /* EXECUTE_AS_SHELL */
  49
  50 #include "utilvfs.h"
  51 #include "vfs.h"
  52 #include "vfs-impl.h"
  53 #include "gc.h"         /* vfs_stamp_create */
  54 #include "local.h"
  55
  56 struct cachedfile {
  57     char *name, *cache;
  58     struct cachedfile *next;
  59 };
  60
  61 static struct cachedfile *head;
  62 static struct vfs_class vfs_sfs_ops;
  63
  64 #define MAXFS 32
  65 static int sfs_no = 0;
  66 static char *sfs_prefix[ MAXFS ];
  67 static char *sfs_command[ MAXFS ];
  68 static int sfs_flags[ MAXFS ];
  69 #define F_1 1
  70 #define F_2 2
  71 #define F_NOLOCALCOPY 4
  72 #define F_FULLMATCH 8
  73
  74 static int
  75 sfs_vfmake (struct vfs_class *me, const char *name, char *cache)
  76 {
  77     char *inpath, *op;
  78     int w;
  79     char pad[10240];
  80     char *s, *t = pad;
  81     int was_percent = 0;
  82     char *pname;        /* name of parent archive */
  83     char *pqname;       /* name of parent archive, quoted */
  84
  85     pname = g_strdup (name);
  86     vfs_split (pname, &inpath, &op);
  87     if ((w = (*me->which) (me, op)) == -1)
  88         vfs_die ("This cannot happen... Hopefully.\n");
  89
  90     if (!(sfs_flags[w] & F_1) && strcmp (pname, "/")) {
  91         g_free (pname);
  92         return -1;
  93     }
  94
  95     /*    if ((sfs_flags[w] & F_2) || (!inpath) || (!*inpath)); else return -1; */
  96     if (!(sfs_flags[w] & F_NOLOCALCOPY)) {
  97         s = mc_getlocalcopy (pname);
  98         if (!s) {
  99             g_free (pname);
 100             return -1;
 101         }
 102         pqname = name_quote (s, 0);
 103         g_free (s);
 104     } else {
 105         pqname = name_quote (pname, 0);
 106     }
 107     g_free (pname);
 108
 109 #define COPY_CHAR \
 110     if ((size_t) (t-pad) > sizeof(pad)) { \
 111         g_free (pqname); \
 112         return -1; \
 113     } \
 114     else \
 115         *t++ = *s;
 116
 117 #define COPY_STRING(a) \
 118     if ((t-pad)+strlen(a)>sizeof(pad)) { \
 119         g_free (pqname); \
 120         return -1; \
 121     } else { \
 122         strcpy (t, a); \
 123         t+= strlen(a); \
 124     }
 125
 126     for (s = sfs_command[w]; *s; s++) {
 127         if (was_percent) {
 128
 129             const char *ptr = NULL;
 130             was_percent = 0;
 131
 132             switch (*s) {
 133             case '1':
 134                 ptr = pqname;
 135                 break;
 136             case '2':
 137                 ptr = op + strlen (sfs_prefix[w]);
 138                 break;
 139             case '3':
 140                 ptr = cache;
 141                 break;
 142             case '%':
 143                 COPY_CHAR;
 144                 continue;
 145             }
 146             COPY_STRING (ptr);
 147         } else {
 148             if (*s == '%')
 149                 was_percent = 1;
 150             else
 151                 COPY_CHAR;
 152         }
 153     }
 154
 155     g_free (pqname);
 156     open_error_pipe ();
 157     if (my_system (EXECUTE_AS_SHELL, "/bin/sh", pad)) {
 158         close_error_pipe (D_ERROR, NULL);
 159         return -1;
 160     }
 161
 162     close_error_pipe (D_NORMAL, NULL);
 163     return 0;                   /* OK */
 164 }
 165
 166 static const char *
 167 sfs_redirect (struct vfs_class *me, const char *name)
 168 {
 169     struct cachedfile *cur = head;
 170     char *cache;
 171     int handle;
 172
 173     while (cur) {
 174         if (!strcmp (name, cur->name)) {
 175             vfs_stamp (&vfs_sfs_ops, cur);
 176             return cur->cache;
 177         }
 178         cur = cur->next;
 179     }
 180
 181     handle = vfs_mkstemps (&cache, "sfs", name);
 182
 183     if (handle == -1) {
 184         return "/SOMEONE_PLAYING_DIRTY_TMP_TRICKS_ON_US";
 185     }
 186
 187     close (handle);
 188
 189     if (!sfs_vfmake (me, name, cache)) {
 190         cur = g_new (struct cachedfile, 1);
 191         cur->name = g_strdup (name);
 192         cur->cache = cache;
 193         cur->next = head;
 194         head = cur;
 195
 196         vfs_stamp_create (&vfs_sfs_ops, head);
 197
 198         return cache;
 199     }
 200
 201     unlink (cache);
 202     g_free (cache);
 203     return "/I_MUST_NOT_EXIST";
 204 }
 205
 206 static void *
 207 sfs_open (struct vfs_class *me, const char *path, int flags, int mode)
 208 {
 209     int *sfs_info;
 210     int fd;
 211
 212     path = sfs_redirect (me, path);
 213     fd = open (path, NO_LINEAR (flags), mode);
 214     if (fd == -1)
 215         return 0;
 216
 217     sfs_info = g_new (int, 1);
 218     *sfs_info = fd;
 219
 220     return sfs_info;
 221 }
 222
 223 static int sfs_stat (struct vfs_class *me, const char *path, struct stat *buf)
 224 {
 225     path = sfs_redirect (me, path);
 226     return stat (path, buf);
 227 }
 228
 229 static int sfs_lstat (struct vfs_class *me, const char *path, struct stat *buf)
 230 {
 231     path = sfs_redirect (me, path);
 232 #ifndef HAVE_STATLSTAT
 233     return lstat (path, buf);
 234 #else
 235     return statlstat (path, buf);
 236 #endif
 237 }
 238
 239 static int sfs_chmod (struct vfs_class *me, const char *path, int mode)
 240 {
 241     path = sfs_redirect (me, path);
 242     return chmod (path, mode);
 243 }
 244
 245 static int sfs_chown (struct vfs_class *me, const char *path, int owner, int group)
 246 {
 247     path = sfs_redirect (me, path);
 248     return chown (path, owner, group);
 249 }
 250
 251 static int sfs_utime (struct vfs_class *me, const char *path, struct utimbuf *times)
 252 {
 253     path = sfs_redirect (me, path);
 254     return utime (path, times);
 255 }
 256
 257 static int
 258 sfs_readlink (struct vfs_class *me, const char *path, char *buf, size_t size)
 259 {
 260     path = sfs_redirect (me, path);
 261     return readlink (path, buf, size);
 262 }
 263
 264 static vfsid
 265 sfs_getid (struct vfs_class *me, const char *path)
 266 {
 267     struct cachedfile *cur = head;
 268
 269     (void) me;
 270
 271     while (cur) {
 272         if (!strcmp (path, cur->name))
 273             break;
 274         cur = cur->next;
 275     }
 276
 277     return (vfsid) cur;
 278 }
 279
 280 static void sfs_free (vfsid id)
 281 {
 282     struct cachedfile *which = (struct cachedfile *) id;
 283     struct cachedfile *cur, *prev;
 284
 285     for (cur = head, prev = 0; cur && cur != which; prev = cur, cur = cur->next)
 286         ;
 287     if (!cur)
 288         vfs_die( "Free of thing which is unknown to me\n" );
 289     unlink (cur->cache);
 290
 291     if (prev)
 292         prev->next = cur->next;
 293     else
 294         head = cur->next;
 295
 296     g_free (cur->cache);
 297     g_free (cur->name);
 298     g_free (cur);
 299 }
 300
 301 static void sfs_fill_names (struct vfs_class *me, fill_names_f func)
 302 {
 303     struct cachedfile *cur = head;
 304
 305     (void) me;
 306
 307     while (cur){
 308         (*func)(cur->name);
 309         cur = cur->next;
 310     }
 311 }
 312
 313 static int sfs_nothingisopen (vfsid id)
 314 {
 315     /* FIXME: Investigate whether have to guard this like in
 316        the other VFSs (see fd_usage in extfs) -- Norbert */
 317     (void) id;
 318     return 1;
 319 }
 320
 321 static char *
 322 sfs_getlocalcopy (struct vfs_class *me, const char *path)
 323 {
 324     path = sfs_redirect (me, path);
 325     return g_strdup (path);
 326 }
 327
 328 static int
 329 sfs_ungetlocalcopy (struct vfs_class *me, const char *path,
 330                     const char *local, int has_changed)
 331 {
 332     (void) me;
 333     (void) path;
 334     (void) local;
 335     (void) has_changed;
 336     return 0;
 337 }
 338
 339 static int sfs_init (struct vfs_class *me)
 340 {
 341     char *mc_sfsini;
 342     FILE *cfg;
 343     char key[256];
 344
 345     (void) me;
 346
 347     mc_sfsini = concat_dir_and_file (mc_home, "extfs" PATH_SEP_STR "sfs.ini");
 348     cfg = fopen (mc_sfsini, "r");
 349
 350     if (!cfg){
 351         fprintf (stderr, _("Warning: file %s not found\n"), mc_sfsini);
 352         g_free (mc_sfsini);
 353         return 0;
 354     }
 355     g_free (mc_sfsini);
 356
 357     sfs_no = 0;
 358     while (sfs_no < MAXFS && fgets (key, sizeof (key), cfg)) {
 359         char *c, *semi = NULL, flags = 0;
 360
 361         if (*key == '#' || *key == '\n')
 362             continue;
 363
 364         for (c = key; *c; c++)
 365             if ((*c == ':') || (*c == '/')){
 366                 semi = c;
 367                 if (*c == '/'){
 368                     *c = 0;
 369                     flags |= F_FULLMATCH;
 370                 }
 371                 break;
 372             }
 373
 374         if (!semi){
 375         invalid_line:
 376             fprintf (stderr, _("Warning: Invalid line in %s:\n%s\n"),
 377                      "sfs.ini", key);
 378             continue;
 379         }
 380
 381         c = semi + 1;
 382         while (*c && (*c != ' ') && (*c != '\t')) {
 383             switch (*c) {
 384             case '1': flags |= F_1; break;
 385             case '2': flags |= F_2; break;
 386             case 'R': flags |= F_NOLOCALCOPY; break;
 387             default:
 388                 fprintf (stderr, _("Warning: Invalid flag %c in %s:\n%s\n"),
 389                          *c, "sfs.ini", key);
 390             }
 391             c++;
 392         }
 393         if (!*c)
 394             goto invalid_line;
 395         c++;
 396         *(semi+1) = 0;
 397         if ((semi = strchr (c, '\n')))
 398             *semi = 0;
 399
 400         sfs_prefix [sfs_no] = g_strdup (key);
 401         sfs_command [sfs_no] = g_strdup (c);
 402         sfs_flags [sfs_no] = flags;
 403         sfs_no++;
 404     }
 405     fclose (cfg);
 406     return 1;
 407 }
 408
 409 static void
 410 sfs_done (struct vfs_class *me)
 411 {
 412     int i;
 413
 414     (void) me;
 415
 416     for (i = 0; i < sfs_no; i++){
 417         g_free (sfs_prefix [i]);
 418         g_free (sfs_command [i]);
 419         sfs_prefix [i] = sfs_command [i] = NULL;
 420     }
 421     sfs_no = 0;
 422 }
 423
 424 static int
 425 sfs_which (struct vfs_class *me, const char *path)
 426 {
 427     int i;
 428
 429     (void) me;
 430
 431     for (i = 0; i < sfs_no; i++)
 432         if (sfs_flags [i] & F_FULLMATCH) {
 433             if (!strcmp (path, sfs_prefix [i]))
 434                 return i;
 435         } else
 436             if (!strncmp (path, sfs_prefix [i], strlen (sfs_prefix [i])))
 437                 return i;
 438
 439     return -1;
 440 }
 441
 442 void
 443 init_sfs (void)
 444 {
 445     vfs_sfs_ops.name = "sfs";
 446     vfs_sfs_ops.init = sfs_init;
 447     vfs_sfs_ops.done = sfs_done;
 448     vfs_sfs_ops.fill_names = sfs_fill_names;
 449     vfs_sfs_ops.which = sfs_which;
 450     vfs_sfs_ops.open = sfs_open;
 451     vfs_sfs_ops.close = local_close;
 452     vfs_sfs_ops.read = local_read;
 453     vfs_sfs_ops.stat = sfs_stat;
 454     vfs_sfs_ops.lstat = sfs_lstat;
 455     vfs_sfs_ops.fstat = local_fstat;
 456     vfs_sfs_ops.chmod = sfs_chmod;
 457     vfs_sfs_ops.chown = sfs_chown;
 458     vfs_sfs_ops.utime = sfs_utime;
 459     vfs_sfs_ops.readlink = sfs_readlink;
 460     vfs_sfs_ops.ferrno = local_errno;
 461     vfs_sfs_ops.lseek = local_lseek;
 462     vfs_sfs_ops.getid = sfs_getid;
 463     vfs_sfs_ops.nothingisopen = sfs_nothingisopen;
 464     vfs_sfs_ops.free = sfs_free;
 465     vfs_sfs_ops.getlocalcopy = sfs_getlocalcopy;
 466     vfs_sfs_ops.ungetlocalcopy = sfs_ungetlocalcopy;
 467     vfs_register_class (&vfs_sfs_ops);
 468 }