gio/gdummyfile.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Alexander Larsson <alexl@redhat.com>
  19  */
  20
  21 #include "config.h"
  22
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <stdlib.h>
  29
  30 #include "gdummyfile.h"
  31 #include "gfile.h"
  32
  33
  34 static void g_dummy_file_file_iface_init (GFileIface *iface);
  35
  36 typedef struct {
  37   char *scheme;
  38   char *userinfo;
  39   char *host;
  40   int port; /* -1 => not in uri */
  41   char *path;
  42   char *query;
  43   char *fragment;
  44 } GDecodedUri;
  45
  46 struct _GDummyFile
  47 {
  48   GObject parent_instance;
  49
  50   GDecodedUri *decoded_uri;
  51   char *text_uri;
  52 };
  53
  54 #define g_dummy_file_get_type _g_dummy_file_get_type
  55 G_DEFINE_TYPE_WITH_CODE (GDummyFile, g_dummy_file, G_TYPE_OBJECT,
  56                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE,
  57                                                 g_dummy_file_file_iface_init))
  58
  59 #define SUB_DELIM_CHARS  "!$&'()*+,;="
  60
  61 static char *       _g_encode_uri       (GDecodedUri *decoded);
  62 static void         _g_decoded_uri_free (GDecodedUri *decoded);
  63 static GDecodedUri *_g_decode_uri       (const char  *uri);
  64 static GDecodedUri *_g_decoded_uri_new  (void);
  65
  66 static char * unescape_string (const gchar *escaped_string,
  67                                const gchar *escaped_string_end,
  68                                const gchar *illegal_characters);
  69
  70 static void g_string_append_encoded (GString    *string,
  71                                      const char *encoded,
  72                                      const char *reserved_chars_allowed);
  73
  74 static void
  75 g_dummy_file_finalize (GObject *object)
  76 {
  77   GDummyFile *dummy;
  78
  79   dummy = G_DUMMY_FILE (object);
  80
  81   if (dummy->decoded_uri)
  82     _g_decoded_uri_free (dummy->decoded_uri);
  83
  84   g_free (dummy->text_uri);
  85
  86   G_OBJECT_CLASS (g_dummy_file_parent_class)->finalize (object);
  87 }
  88
  89 static void
  90 g_dummy_file_class_init (GDummyFileClass *klass)
  91 {
  92   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  93
  94   gobject_class->finalize = g_dummy_file_finalize;
  95 }
  96
  97 static void
  98 g_dummy_file_init (GDummyFile *dummy)
  99 {
 100 }
 101
 102 GFile *
 103 _g_dummy_file_new (const char *uri)
 104 {
 105   GDummyFile *dummy;
 106
 107   g_return_val_if_fail (uri != NULL, NULL);
 108
 109   dummy = g_object_new (G_TYPE_DUMMY_FILE, NULL);
 110   dummy->text_uri = g_strdup (uri);
 111   dummy->decoded_uri = _g_decode_uri (uri);
 112
 113   return G_FILE (dummy);
 114 }
 115
 116 static gboolean
 117 g_dummy_file_is_native (GFile *file)
 118 {
 119   return FALSE;
 120 }
 121
 122 static char *
 123 g_dummy_file_get_basename (GFile *file)
 124 {
 125   GDummyFile *dummy = G_DUMMY_FILE (file);
 126
 127   if (dummy->decoded_uri)
 128     return g_path_get_basename (dummy->decoded_uri->path);
 129   return g_strdup (dummy->text_uri);
 130 }
 131
 132 static char *
 133 g_dummy_file_get_path (GFile *file)
 134 {
 135   return NULL;
 136 }
 137
 138 static char *
 139 g_dummy_file_get_uri (GFile *file)
 140 {
 141   return g_strdup (G_DUMMY_FILE (file)->text_uri);
 142 }
 143
 144 static char *
 145 g_dummy_file_get_parse_name (GFile *file)
 146 {
 147   return g_strdup (G_DUMMY_FILE (file)->text_uri);
 148 }
 149
 150 static GFile *
 151 g_dummy_file_get_parent (GFile *file)
 152 {
 153   GDummyFile *dummy = G_DUMMY_FILE (file);
 154   GFile *parent;
 155   char *dirname;
 156   char *uri;
 157   GDecodedUri new_decoded_uri;
 158
 159   if (dummy->decoded_uri == NULL ||
 160       g_strcmp0 (dummy->decoded_uri->path, "/") == 0)
 161     return NULL;
 162
 163   dirname = g_path_get_dirname (dummy->decoded_uri->path);
 164
 165   if (strcmp (dirname, ".") == 0)
 166     {
 167       g_free (dirname);
 168       return NULL;
 169     }
 170
 171   new_decoded_uri = *dummy->decoded_uri;
 172   new_decoded_uri.path = dirname;
 173   uri = _g_encode_uri (&new_decoded_uri);
 174   g_free (dirname);
 175
 176   parent = _g_dummy_file_new (uri);
 177   g_free (uri);
 178
 179   return parent;
 180 }
 181
 182 static GFile *
 183 g_dummy_file_dup (GFile *file)
 184 {
 185   GDummyFile *dummy = G_DUMMY_FILE (file);
 186
 187   return _g_dummy_file_new (dummy->text_uri);
 188 }
 189
 190 static guint
 191 g_dummy_file_hash (GFile *file)
 192 {
 193   GDummyFile *dummy = G_DUMMY_FILE (file);
 194
 195   return g_str_hash (dummy->text_uri);
 196 }
 197
 198 static gboolean
 199 g_dummy_file_equal (GFile *file1,
 200                     GFile *file2)
 201 {
 202   GDummyFile *dummy1 = G_DUMMY_FILE (file1);
 203   GDummyFile *dummy2 = G_DUMMY_FILE (file2);
 204
 205   return g_str_equal (dummy1->text_uri, dummy2->text_uri);
 206 }
 207
 208 static int
 209 safe_strcmp (const char *a,
 210              const char *b)
 211 {
 212   if (a == NULL)
 213     a = "";
 214   if (b == NULL)
 215     b = "";
 216
 217   return strcmp (a, b);
 218 }
 219
 220 static gboolean
 221 uri_same_except_path (GDecodedUri *a,
 222                       GDecodedUri *b)
 223 {
 224   if (safe_strcmp (a->scheme, b->scheme) != 0)
 225     return FALSE;
 226   if (safe_strcmp (a->userinfo, b->userinfo) != 0)
 227     return FALSE;
 228   if (safe_strcmp (a->host, b->host) != 0)
 229     return FALSE;
 230   if (a->port != b->port)
 231     return FALSE;
 232
 233   return TRUE;
 234 }
 235
 236 static const char *
 237 match_prefix (const char *path,
 238               const char *prefix)
 239 {
 240   int prefix_len;
 241
 242   prefix_len = strlen (prefix);
 243   if (strncmp (path, prefix, prefix_len) != 0)
 244     return NULL;
 245   return path + prefix_len;
 246 }
 247
 248 static gboolean
 249 g_dummy_file_prefix_matches (GFile *parent, GFile *descendant)
 250 {
 251   GDummyFile *parent_dummy = G_DUMMY_FILE (parent);
 252   GDummyFile *descendant_dummy = G_DUMMY_FILE (descendant);
 253   const char *remainder;
 254
 255   if (parent_dummy->decoded_uri != NULL &&
 256       descendant_dummy->decoded_uri != NULL)
 257     {
 258       if (uri_same_except_path (parent_dummy->decoded_uri,
 259                                 descendant_dummy->decoded_uri))
 260         {
 261           remainder = match_prefix (descendant_dummy->decoded_uri->path,
 262                                     parent_dummy->decoded_uri->path);
 263           if (remainder != NULL && *remainder == '/')
 264             {
 265               while (*remainder == '/')
 266                 remainder++;
 267               if (*remainder != 0)
 268                 return TRUE;
 269             }
 270         }
 271     }
 272   else
 273     {
 274       remainder = match_prefix (descendant_dummy->text_uri,
 275                                 parent_dummy->text_uri);
 276       if (remainder != NULL && *remainder == '/')
 277           {
 278             while (*remainder == '/')
 279               remainder++;
 280             if (*remainder != 0)
 281               return TRUE;
 282           }
 283     }
 284
 285   return FALSE;
 286 }
 287
 288 static char *
 289 g_dummy_file_get_relative_path (GFile *parent,
 290                                 GFile *descendant)
 291 {
 292   GDummyFile *parent_dummy = G_DUMMY_FILE (parent);
 293   GDummyFile *descendant_dummy = G_DUMMY_FILE (descendant);
 294   const char *remainder;
 295
 296   if (parent_dummy->decoded_uri != NULL &&
 297       descendant_dummy->decoded_uri != NULL)
 298     {
 299       if (uri_same_except_path (parent_dummy->decoded_uri,
 300                                 descendant_dummy->decoded_uri))
 301         {
 302           remainder = match_prefix (descendant_dummy->decoded_uri->path,
 303                                     parent_dummy->decoded_uri->path);
 304           if (remainder != NULL && *remainder == '/')
 305             {
 306               while (*remainder == '/')
 307                 remainder++;
 308               if (*remainder != 0)
 309                 return g_strdup (remainder);
 310             }
 311         }
 312     }
 313   else
 314     {
 315       remainder = match_prefix (descendant_dummy->text_uri,
 316                                 parent_dummy->text_uri);
 317       if (remainder != NULL && *remainder == '/')
 318           {
 319             while (*remainder == '/')
 320               remainder++;
 321             if (*remainder != 0)
 322               return unescape_string (remainder, NULL, "/");
 323           }
 324     }
 325
 326   return NULL;
 327 }
 328
 329
 330 static GFile *
 331 g_dummy_file_resolve_relative_path (GFile      *file,
 332                                     const char *relative_path)
 333 {
 334   GDummyFile *dummy = G_DUMMY_FILE (file);
 335   GFile *child;
 336   char *uri;
 337   GDecodedUri new_decoded_uri;
 338   GString *str;
 339
 340   if (dummy->decoded_uri == NULL)
 341     {
 342       str = g_string_new (dummy->text_uri);
 343       g_string_append (str, "/");
 344       g_string_append_encoded (str, relative_path, SUB_DELIM_CHARS ":@/");
 345       child = _g_dummy_file_new (str->str);
 346       g_string_free (str, TRUE);
 347     }
 348   else
 349     {
 350       new_decoded_uri = *dummy->decoded_uri;
 351
 352       if (g_path_is_absolute (relative_path))
 353         new_decoded_uri.path = g_strdup (relative_path);
 354       else
 355         new_decoded_uri.path = g_build_filename (new_decoded_uri.path, relative_path, NULL);
 356
 357       uri = _g_encode_uri (&new_decoded_uri);
 358       g_free (new_decoded_uri.path);
 359
 360       child = _g_dummy_file_new (uri);
 361       g_free (uri);
 362     }
 363
 364   return child;
 365 }
 366
 367 static GFile *
 368 g_dummy_file_get_child_for_display_name (GFile        *file,
 369                                          const char   *display_name,
 370                                          GError      **error)
 371 {
 372   return g_file_get_child (file, display_name);
 373 }
 374
 375 static gboolean
 376 g_dummy_file_has_uri_scheme (GFile *file,
 377                              const char *uri_scheme)
 378 {
 379   GDummyFile *dummy = G_DUMMY_FILE (file);
 380
 381   if (dummy->decoded_uri)
 382     return g_ascii_strcasecmp (uri_scheme, dummy->decoded_uri->scheme) == 0;
 383   return FALSE;
 384 }
 385
 386 static char *
 387 g_dummy_file_get_uri_scheme (GFile *file)
 388 {
 389   GDummyFile *dummy = G_DUMMY_FILE (file);
 390
 391   if (dummy->decoded_uri)
 392     return g_strdup (dummy->decoded_uri->scheme);
 393
 394   return NULL;
 395 }
 396
 397
 398 static void
 399 g_dummy_file_file_iface_init (GFileIface *iface)
 400 {
 401   iface->dup = g_dummy_file_dup;
 402   iface->hash = g_dummy_file_hash;
 403   iface->equal = g_dummy_file_equal;
 404   iface->is_native = g_dummy_file_is_native;
 405   iface->has_uri_scheme = g_dummy_file_has_uri_scheme;
 406   iface->get_uri_scheme = g_dummy_file_get_uri_scheme;
 407   iface->get_basename = g_dummy_file_get_basename;
 408   iface->get_path = g_dummy_file_get_path;
 409   iface->get_uri = g_dummy_file_get_uri;
 410   iface->get_parse_name = g_dummy_file_get_parse_name;
 411   iface->get_parent = g_dummy_file_get_parent;
 412   iface->prefix_matches = g_dummy_file_prefix_matches;
 413   iface->get_relative_path = g_dummy_file_get_relative_path;
 414   iface->resolve_relative_path = g_dummy_file_resolve_relative_path;
 415   iface->get_child_for_display_name = g_dummy_file_get_child_for_display_name;
 416
 417   iface->supports_thread_contexts = TRUE;
 418 }
 419
 420 /* Uri handling helper functions: */
 421
 422 static int
 423 unescape_character (const char *scanner)
 424 {
 425   int first_digit;
 426   int second_digit;
 427
 428   first_digit = g_ascii_xdigit_value (*scanner++);
 429   if (first_digit < 0)
 430     return -1;
 431
 432   second_digit = g_ascii_xdigit_value (*scanner++);
 433   if (second_digit < 0)
 434     return -1;
 435
 436   return (first_digit << 4) | second_digit;
 437 }
 438
 439 static char *
 440 unescape_string (const gchar *escaped_string,
 441                  const gchar *escaped_string_end,
 442                  const gchar *illegal_characters)
 443 {
 444   const gchar *in;
 445   gchar *out, *result;
 446   gint character;
 447
 448   if (escaped_string == NULL)
 449     return NULL;
 450
 451   if (escaped_string_end == NULL)
 452     escaped_string_end = escaped_string + strlen (escaped_string);
 453
 454   result = g_malloc (escaped_string_end - escaped_string + 1);
 455
 456   out = result;
 457   for (in = escaped_string; in < escaped_string_end; in++)
 458     {
 459       character = *in;
 460       if (*in == '%')
 461         {
 462           in++;
 463           if (escaped_string_end - in < 2)
 464             {
 465               g_free (result);
 466               return NULL;
 467             }
 468
 469           character = unescape_character (in);
 470
 471           /* Check for an illegal character. We consider '\0' illegal here. */
 472           if (character <= 0 ||
 473               (illegal_characters != NULL &&
 474                strchr (illegal_characters, (char)character) != NULL))
 475             {
 476               g_free (result);
 477               return NULL;
 478             }
 479           in++; /* The other char will be eaten in the loop header */
 480         }
 481       *out++ = (char)character;
 482     }
 483
 484   *out = '\0';
 485   g_warn_if_fail (out - result <= strlen (escaped_string));
 486   return result;
 487 }
 488
 489 void
 490 _g_decoded_uri_free (GDecodedUri *decoded)
 491 {
 492   if (decoded == NULL)
 493     return;
 494
 495   g_free (decoded->scheme);
 496   g_free (decoded->query);
 497   g_free (decoded->fragment);
 498   g_free (decoded->userinfo);
 499   g_free (decoded->host);
 500   g_free (decoded->path);
 501   g_free (decoded);
 502 }
 503
 504 GDecodedUri *
 505 _g_decoded_uri_new (void)
 506 {
 507   GDecodedUri *uri;
 508
 509   uri = g_new0 (GDecodedUri, 1);
 510   uri->port = -1;
 511
 512   return uri;
 513 }
 514
 515 GDecodedUri *
 516 _g_decode_uri (const char *uri)
 517 {
 518   GDecodedUri *decoded;
 519   const char *p, *in, *hier_part_start, *hier_part_end, *query_start, *fragment_start;
 520   char *out;
 521   char c;
 522
 523   /* From RFC 3986 Decodes:
 524    * URI         = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
 525    */
 526
 527   p = uri;
 528
 529   /* Decode scheme:
 530      scheme      = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
 531   */
 532
 533   if (!g_ascii_isalpha (*p))
 534     return NULL;
 535
 536   while (1)
 537     {
 538       c = *p++;
 539
 540       if (c == ':')
 541         break;
 542
 543       if (!(g_ascii_isalnum(c) ||
 544             c == '+' ||
 545             c == '-' ||
 546             c == '.'))
 547         return NULL;
 548     }
 549
 550   decoded = _g_decoded_uri_new ();
 551
 552   decoded->scheme = g_malloc (p - uri);
 553   out = decoded->scheme;
 554   for (in = uri; in < p - 1; in++)
 555     *out++ = g_ascii_tolower (*in);
 556   *out = 0;
 557
 558   hier_part_start = p;
 559
 560   query_start = strchr (p, '?');
 561   if (query_start)
 562     {
 563       hier_part_end = query_start++;
 564       fragment_start = strchr (query_start, '#');
 565       if (fragment_start)
 566         {
 567           decoded->query = g_strndup (query_start, fragment_start - query_start);
 568           decoded->fragment = g_strdup (fragment_start+1);
 569         }
 570       else
 571         {
 572           decoded->query = g_strdup (query_start);
 573           decoded->fragment = NULL;
 574         }
 575     }
 576   else
 577     {
 578       /* No query */
 579       decoded->query = NULL;
 580       fragment_start = strchr (p, '#');
 581       if (fragment_start)
 582         {
 583           hier_part_end = fragment_start++;
 584           decoded->fragment = g_strdup (fragment_start);
 585         }
 586       else
 587         {
 588           hier_part_end = p + strlen (p);
 589           decoded->fragment = NULL;
 590         }
 591     }
 592
 593   /*  3:
 594       hier-part   = "//" authority path-abempty
 595                   / path-absolute
 596                   / path-rootless
 597                   / path-empty
 598
 599   */
 600
 601   if (hier_part_start[0] == '/' &&
 602       hier_part_start[1] == '/')
 603     {
 604       const char *authority_start, *authority_end;
 605       const char *userinfo_start, *userinfo_end;
 606       const char *host_start, *host_end;
 607       const char *port_start;
 608
 609       authority_start = hier_part_start + 2;
 610       /* authority is always followed by / or nothing */
 611       authority_end = memchr (authority_start, '/', hier_part_end - authority_start);
 612       if (authority_end == NULL)
 613         authority_end = hier_part_end;
 614
 615       /* 3.2:
 616               authority   = [ userinfo "@" ] host [ ":" port ]
 617       */
 618
 619       userinfo_end = memchr (authority_start, '@', authority_end - authority_start);
 620       if (userinfo_end)
 621         {
 622           userinfo_start = authority_start;
 623           decoded->userinfo = unescape_string (userinfo_start, userinfo_end, NULL);
 624           if (decoded->userinfo == NULL)
 625             {
 626               _g_decoded_uri_free (decoded);
 627               return NULL;
 628             }
 629           host_start = userinfo_end + 1;
 630         }
 631       else
 632         host_start = authority_start;
 633
 634       port_start = memchr (host_start, ':', authority_end - host_start);
 635       if (port_start)
 636         {
 637           host_end = port_start++;
 638
 639           decoded->port = atoi(port_start);
 640         }
 641       else
 642         {
 643           host_end = authority_end;
 644           decoded->port = -1;
 645         }
 646
 647       decoded->host = g_strndup (host_start, host_end - host_start);
 648
 649       hier_part_start = authority_end;
 650     }
 651
 652   decoded->path = unescape_string (hier_part_start, hier_part_end, "/");
 653
 654   if (decoded->path == NULL)
 655     {
 656       _g_decoded_uri_free (decoded);
 657       return NULL;
 658     }
 659
 660   return decoded;
 661 }
 662
 663 static gboolean
 664 is_valid (char c, const char *reserved_chars_allowed)
 665 {
 666   if (g_ascii_isalnum (c) ||
 667       c == '-' ||
 668       c == '.' ||
 669       c == '_' ||
 670       c == '~')
 671     return TRUE;
 672
 673   if (reserved_chars_allowed &&
 674       strchr (reserved_chars_allowed, c) != NULL)
 675     return TRUE;
 676
 677   return FALSE;
 678 }
 679
 680 static void
 681 g_string_append_encoded (GString    *string,
 682                          const char *encoded,
 683                          const char *reserved_chars_allowed)
 684 {
 685   unsigned char c;
 686   static const gchar hex[16] = "0123456789ABCDEF";
 687
 688   while ((c = *encoded) != 0)
 689     {
 690       if (is_valid (c, reserved_chars_allowed))
 691         {
 692           g_string_append_c (string, c);
 693           encoded++;
 694         }
 695       else
 696         {
 697           g_string_append_c (string, '%');
 698           g_string_append_c (string, hex[((guchar)c) >> 4]);
 699           g_string_append_c (string, hex[((guchar)c) & 0xf]);
 700           encoded++;
 701         }
 702     }
 703 }
 704
 705 static char *
 706 _g_encode_uri (GDecodedUri *decoded)
 707 {
 708   GString *uri;
 709
 710   uri = g_string_new (NULL);
 711
 712   g_string_append (uri, decoded->scheme);
 713   g_string_append (uri, "://");
 714
 715   if (decoded->host != NULL)
 716     {
 717       if (decoded->userinfo)
 718         {
 719           /* userinfo    = *( unreserved / pct-encoded / sub-delims / ":" ) */
 720           g_string_append_encoded (uri, decoded->userinfo, SUB_DELIM_CHARS ":");
 721           g_string_append_c (uri, '@');
 722         }
 723
 724       g_string_append (uri, decoded->host);
 725
 726       if (decoded->port != -1)
 727         {
 728           g_string_append_c (uri, ':');
 729           g_string_append_printf (uri, "%d", decoded->port);
 730         }
 731     }
 732
 733   g_string_append_encoded (uri, decoded->path, SUB_DELIM_CHARS ":@/");
 734
 735   if (decoded->query)
 736     {
 737       g_string_append_c (uri, '?');
 738       g_string_append (uri, decoded->query);
 739     }
 740
 741   if (decoded->fragment)
 742     {
 743       g_string_append_c (uri, '#');
 744       g_string_append (uri, decoded->fragment);
 745     }
 746
 747   return g_string_free (uri, FALSE);
 748 }