epan/plugins.c

   1 /* plugins.c
   2  * plugin routines
   3  *
   4  * $Id: plugins.c,v 1.29 2001/08/21 08:16:54 guy Exp $
   5  *
   6  * Ethereal - Network traffic analyzer
   7  * By Gerald Combs <gerald@ethereal.com>
   8  * Copyright 1999 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program 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, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  23  */
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <epan.h>
  30 #include "plugins.h"
  31
  32 #ifdef HAVE_PLUGINS
  33
  34 #include <time.h>
  35
  36 #ifdef HAVE_DIRENT_H
  37 #include <dirent.h>
  38 #endif
  39
  40 #ifdef HAVE_DIRECT_H
  41 #include <direct.h>
  42 #endif
  43
  44 #include <string.h>
  45 #include <stdlib.h>
  46 #include <errno.h>
  47
  48 #ifdef HAVE_SYS_STAT_H
  49 #include <sys/stat.h>
  50 #endif
  51
  52 #ifdef HAVE_SYS_TYPES_H
  53 #include <sys/types.h>
  54 #endif
  55
  56 #ifdef HAVE_UNISTD_H
  57 #include <unistd.h>
  58 #endif
  59
  60 #include "filesystem.h"
  61
  62 #include "prefs.h"
  63
  64 #ifdef PLUGINS_NEED_ADDRESS_TABLE
  65 #include "packet-giop.h"
  66 #include "plugins/plugin_table.h"
  67 static plugin_address_table_t   patable;
  68 #endif
  69
  70 /* linked list of all plugins */
  71 plugin *plugin_list;
  72
  73 #ifndef WIN32
  74 static gchar std_plug_dir[] = "/usr/lib/ethereal/plugins/" VERSION;
  75 static gchar local_plug_dir[] = "/usr/local/lib/ethereal/plugins/" VERSION;
  76 #endif
  77 static gchar *user_plug_dir = NULL;
  78
  79 #define PLUGINS_DIR_NAME        "plugins"
  80
  81 /*
  82  * add a new plugin to the list
  83  * returns :
  84  * - 0 : OK
  85  * - ENOMEM : memory allocation problem
  86  * - EEXIST : the same plugin (i.e. name/version) was already registered.
  87  */
  88 static int
  89 add_plugin(void *handle, gchar *name, gchar *version,
  90            void (*reg_handoff)(void))
  91 {
  92     plugin *new_plug, *pt_plug;
  93
  94     pt_plug = plugin_list;
  95     if (!pt_plug) /* the list is empty */
  96     {
  97         new_plug = (plugin *)g_malloc(sizeof(plugin));
  98         if (new_plug == NULL) return ENOMEM;
  99         plugin_list = new_plug;
 100     }
 101     else
 102     {
 103         while (1)
 104         {
 105             /* check if the same name/version is already registered */
 106             if (!strcmp(pt_plug->name, name) &&
 107                 !strcmp(pt_plug->version, version))
 108             {
 109                 return EEXIST;
 110             }
 111
 112             /* we found the last plugin in the list */
 113             if (pt_plug->next == NULL) break;
 114
 115             pt_plug = pt_plug->next;
 116         }
 117         new_plug = (plugin *)g_malloc(sizeof(plugin));
 118         if (new_plug == NULL) return ENOMEM;
 119         pt_plug->next = new_plug;
 120     }
 121
 122     new_plug->handle = handle;
 123     new_plug->name = name;
 124     new_plug->version = version;
 125     new_plug->reg_handoff = reg_handoff;
 126     new_plug->next = NULL;
 127     return 0;
 128 }
 129
 130 /*
 131  * XXX - when we remove support for old-style plugins (which we should
 132  * probably do eventually, as all plugins should be written as new-style
 133  * ones), we may want to have "init_plugins()" merely save a pointer
 134  * to the plugin's "init" routine, just as we save a pointer to its
 135  * "reg_handoff" routine, and have a "register_all_plugins()" routine
 136  * to go through the list of plugins and call all of them.
 137  *
 138  * Then we'd have "epan_init()", or perhaps even something higher up
 139  * in the call tree, call "init_plugins()", and have "proto_init()"
 140  * call "register_all_plugins()" right after calling "register_all_protocols()";
 141  * this might be a bit cleaner.
 142  */
 143 static void
 144 plugins_scan_dir(const char *dirname)
 145 {
 146 #define FILENAME_LEN    1024
 147     gchar         *hack_path;       /* pathname used to construct lt_lib_ext */
 148     gchar         *lt_lib_ext;      /* extension for loadable modules */
 149     DIR           *dir;             /* scanned directory */
 150     struct dirent *file;            /* current file */
 151     gchar          filename[FILENAME_LEN];   /* current file name */
 152     GModule       *handle;          /* handle returned by dlopen */
 153     gchar         *name;
 154     gchar         *version;
 155     void         (*init)(void *);
 156     void         (*reg_handoff)(void);
 157     gchar         *dot;
 158     int            cr;
 159
 160     /*
 161      * We find the extension used on this platform for loadable modules
 162      * by the sneaky hack of calling "g_module_build_path" to build
 163      * the pathname for a module with an empty directory name and
 164      * empty module name, and then search for the last "." and use
 165      * everything from the last "." on.
 166      *
 167      * GLib 2.0 will probably define G_MODULE_SUFFIX as the extension
 168      * to use, but that's not checked into the GLib CVS tree yet,
 169      * and we can't use it on systems that don't have GLib 2.0.
 170      */
 171     hack_path = g_module_build_path("", "");
 172     lt_lib_ext = strrchr(hack_path, '.');
 173     if (lt_lib_ext == NULL)
 174     {
 175         /*
 176          * Does this mean there *is* no extension?  Assume so.
 177          *
 178          * XXX - the code below assumes that all loadable modules have
 179          * an extension....
 180          */
 181         lt_lib_ext = "";
 182     }
 183
 184     if ((dir = opendir(dirname)) != NULL)
 185     {
 186         while ((file = readdir(dir)) != NULL)
 187         {
 188             /* don't try to open "." and ".." */
 189             if (!(strcmp(file->d_name, "..") &&
 190                   strcmp(file->d_name, "."))) continue;
 191
 192             /* skip anything but files with lt_lib_ext */
 193             dot = strrchr(file->d_name, '.');
 194             if (dot == NULL || strcmp(dot, lt_lib_ext) != 0) continue;
 195
 196             snprintf(filename, FILENAME_LEN, "%s" G_DIR_SEPARATOR_S "%s",
 197                 dirname, file->d_name);
 198             if ((handle = g_module_open(filename, 0)) == NULL) continue;
 199             name = (gchar *)file->d_name;
 200             if (g_module_symbol(handle, "version", (gpointer*)&version) == FALSE)
 201             {
 202                 g_warning("The plugin %s has no version symbol", name);
 203                 g_module_close(handle);
 204                 continue;
 205             }
 206
 207             /*
 208              * Old-style dissectors don't have a "plugin_reg_handoff()"
 209              * routine; we no longer support them.
 210              *
 211              * New-style dissectors have one, because, otherwise, there's
 212              * no way for them to arrange that they ever be called.
 213              */
 214             if (g_module_symbol(handle, "plugin_reg_handoff",
 215                                          (gpointer*)&reg_handoff))
 216             {
 217                 /*
 218                  * We require it to have a "plugin_init()" routine.
 219                  */
 220                 if (!g_module_symbol(handle, "plugin_init", (gpointer*)&init))
 221                 {
 222                     g_warning("The plugin %s has a plugin_reg_handoff symbol but no plugin_init routine", name);
 223                     g_module_close(handle);
 224                     continue;
 225                 }
 226
 227                 /*
 228                  * We have a "plugin_reg_handoff()" routine, so we don't
 229                  * need the protocol, filter string, or dissector pointer.
 230                  */
 231                 if ((cr = add_plugin(handle, g_strdup(file->d_name), version,
 232                                      reg_handoff)))
 233                 {
 234                     if (cr == EEXIST)
 235                         fprintf(stderr, "The plugin %s, version %s\n"
 236                             "was found in multiple directories\n", name, version);
 237                     else
 238                         fprintf(stderr, "Memory allocation problem\n"
 239                             "when processing plugin %s, version %s\n",
 240                             name, version);
 241                     g_module_close(handle);
 242                     continue;
 243                 }
 244
 245                 /*
 246                  * Call its init routine.
 247                  */
 248 #ifdef PLUGINS_NEED_ADDRESS_TABLE
 249                 init(&patable);
 250 #else
 251                 init(NULL);
 252 #endif
 253             }
 254             else
 255             {
 256                 /*
 257                  * This is an old-style dissector; warn that it won't
 258                  * be used, as those aren't supported.
 259                  */
 260                 fprintf(stderr,
 261                     "The plugin %s, version %s is an old-style plugin;\n"
 262                     "Those are no longer supported.\n", name, version);
 263             }
 264         }
 265         closedir(dir);
 266     }
 267     g_free(hack_path);
 268 }
 269
 270 /*
 271  * init plugins
 272  */
 273 void
 274 init_plugins(const char *plugin_dir)
 275 {
 276 #ifdef WIN32
 277     const char *datafile_dir;
 278     char *install_plugin_dir;
 279 #else
 280     struct stat std_dir_stat, local_dir_stat, plugin_dir_stat;
 281 #endif
 282
 283     if (plugin_list == NULL)      /* ensure init_plugins is only run once */
 284     {
 285 #ifdef PLUGINS_NEED_ADDRESS_TABLE
 286         /* Intialize address table */
 287         patable.p_check_col                     = check_col;
 288         patable.p_col_clear                     = col_clear;
 289         patable.p_col_add_fstr                  = col_add_fstr;
 290         patable.p_col_append_fstr               = col_append_fstr;
 291         patable.p_col_add_str                   = col_add_str;
 292         patable.p_col_append_str                = col_append_str;
 293         patable.p_col_set_str                   = col_set_str;
 294
 295         patable.p_pi                            = &pi;
 296
 297         patable.p_proto_register_protocol       = proto_register_protocol;
 298         patable.p_proto_register_field_array    = proto_register_field_array;
 299         patable.p_proto_register_subtree_array  = proto_register_subtree_array;
 300
 301         patable.p_dissector_add                 = dissector_add;
 302         patable.p_dissector_delete              = dissector_delete;
 303
 304         patable.p_heur_dissector_add            = heur_dissector_add;
 305
 306         patable.p_register_dissector            = register_dissector;
 307         patable.p_find_dissector                = find_dissector;
 308         patable.p_call_dissector                = call_dissector;
 309
 310         patable.p_dissect_data                  = dissect_data;
 311
 312         patable.p_proto_is_protocol_enabled     = proto_is_protocol_enabled;
 313
 314         patable.p_proto_item_get_len            = proto_item_get_len;
 315         patable.p_proto_item_set_len            = proto_item_set_len;
 316         patable.p_proto_item_set_text           = proto_item_set_text;
 317         patable.p_proto_item_add_subtree        = proto_item_add_subtree;
 318         patable.p_proto_tree_add_item           = proto_tree_add_item;
 319         patable.p_proto_tree_add_item_hidden    = proto_tree_add_item_hidden;
 320         patable.p_proto_tree_add_protocol_format = proto_tree_add_protocol_format;
 321         patable.p_proto_tree_add_bytes          = proto_tree_add_bytes;
 322         patable.p_proto_tree_add_bytes_hidden   = proto_tree_add_bytes_hidden;
 323         patable.p_proto_tree_add_bytes_format   = proto_tree_add_bytes_format;
 324         patable.p_proto_tree_add_time           = proto_tree_add_time;
 325         patable.p_proto_tree_add_time_hidden    = proto_tree_add_time_hidden;
 326         patable.p_proto_tree_add_time_format    = proto_tree_add_time_format;
 327         patable.p_proto_tree_add_ipxnet         = proto_tree_add_ipxnet;
 328         patable.p_proto_tree_add_ipxnet_hidden  = proto_tree_add_ipxnet_hidden;
 329         patable.p_proto_tree_add_ipxnet_format  = proto_tree_add_ipxnet_format;
 330         patable.p_proto_tree_add_ipv4           = proto_tree_add_ipv4;
 331         patable.p_proto_tree_add_ipv4_hidden    = proto_tree_add_ipv4_hidden;
 332         patable.p_proto_tree_add_ipv4_format    = proto_tree_add_ipv4_format;
 333         patable.p_proto_tree_add_ipv6           = proto_tree_add_ipv6;
 334         patable.p_proto_tree_add_ipv6_hidden    = proto_tree_add_ipv6_hidden;
 335         patable.p_proto_tree_add_ipv6_format    = proto_tree_add_ipv6_format;
 336         patable.p_proto_tree_add_ether          = proto_tree_add_ether;
 337         patable.p_proto_tree_add_ether_hidden   = proto_tree_add_ether_hidden;
 338         patable.p_proto_tree_add_ether_format   = proto_tree_add_ether_format;
 339         patable.p_proto_tree_add_string         = proto_tree_add_string;
 340         patable.p_proto_tree_add_string_hidden  = proto_tree_add_string_hidden;
 341         patable.p_proto_tree_add_string_format  = proto_tree_add_string_format;
 342         patable.p_proto_tree_add_boolean        = proto_tree_add_boolean;
 343         patable.p_proto_tree_add_boolean_hidden = proto_tree_add_boolean_hidden;
 344         patable.p_proto_tree_add_boolean_format = proto_tree_add_boolean_format;
 345         patable.p_proto_tree_add_double         = proto_tree_add_double;
 346         patable.p_proto_tree_add_double_hidden  = proto_tree_add_double_hidden;
 347         patable.p_proto_tree_add_double_format  = proto_tree_add_double_format;
 348         patable.p_proto_tree_add_uint           = proto_tree_add_uint;
 349         patable.p_proto_tree_add_uint_hidden    = proto_tree_add_uint_hidden;
 350         patable.p_proto_tree_add_uint_format    = proto_tree_add_uint_format;
 351         patable.p_proto_tree_add_int            = proto_tree_add_int;
 352         patable.p_proto_tree_add_int_hidden     = proto_tree_add_int_hidden;
 353         patable.p_proto_tree_add_int_format     = proto_tree_add_int_format;
 354         patable.p_proto_tree_add_text           = proto_tree_add_text;
 355         patable.p_proto_tree_add_notext         = proto_tree_add_notext;
 356
 357         patable.p_tvb_new_subset                = tvb_new_subset;
 358
 359         patable.p_tvb_length                    = tvb_length;
 360         patable.p_tvb_length_remaining          = tvb_length_remaining;
 361         patable.p_tvb_bytes_exist               = tvb_bytes_exist;
 362         patable.p_tvb_offset_exists             = tvb_offset_exists;
 363         patable.p_tvb_reported_length           = tvb_reported_length;
 364         patable.p_tvb_reported_length_remaining = tvb_reported_length_remaining;
 365
 366         patable.p_tvb_get_guint8                = tvb_get_guint8;
 367
 368         patable.p_tvb_get_ntohs                 = tvb_get_ntohs;
 369         patable.p_tvb_get_ntoh24                = tvb_get_ntoh24;
 370         patable.p_tvb_get_ntohl                 = tvb_get_ntohl;
 371 #ifdef G_HAVE_GINT64
 372         patable.p_tvb_get_ntohll                = tvb_get_ntohll;
 373 #endif
 374
 375         patable.p_tvb_get_letohs                = tvb_get_letohs;
 376         patable.p_tvb_get_letoh24               = tvb_get_letoh24;
 377         patable.p_tvb_get_letohl                = tvb_get_letohl;
 378 #ifdef G_HAVE_GINT64
 379         patable.p_tvb_get_letohll               = tvb_get_letohll;
 380 #endif
 381
 382         patable.p_tvb_memcpy                    = tvb_memcpy;
 383         patable.p_tvb_memdup                    = tvb_memdup;
 384
 385         patable.p_tvb_get_ptr                   = tvb_get_ptr;
 386
 387         patable.p_tvb_find_guint8               = tvb_find_guint8;
 388         patable.p_tvb_pbrk_guint8               = tvb_pbrk_guint8;
 389
 390         patable.p_tvb_strnlen                   = tvb_strnlen;
 391
 392         patable.p_tvb_format_text               = tvb_format_text;
 393
 394         patable.p_tvb_get_nstringz              = tvb_get_nstringz;
 395         patable.p_tvb_get_nstringz0             = tvb_get_nstringz0;
 396
 397         patable.p_tvb_find_line_end             = tvb_find_line_end;
 398         patable.p_tvb_find_line_end_unquoted    = tvb_find_line_end_unquoted;
 399
 400         patable.p_tvb_strneql                   = tvb_strneql;
 401         patable.p_tvb_strncaseeql               = tvb_strncaseeql;
 402
 403         patable.p_tvb_bytes_to_str              = tvb_bytes_to_str;
 404
 405         patable.p_prefs_register_protocol       = prefs_register_protocol;
 406         patable.p_prefs_register_uint_preference = prefs_register_uint_preference;
 407         patable.p_prefs_register_bool_preference = prefs_register_bool_preference;
 408         patable.p_prefs_register_enum_preference = prefs_register_enum_preference;
 409
 410         patable.p_register_giop_user            = register_giop_user;
 411         patable.p_is_big_endian                 = is_big_endian;
 412         patable.p_get_CDR_string                = get_CDR_string;
 413         patable.p_get_CDR_ulong                 = get_CDR_ulong;
 414         patable.p_get_CDR_enum                  = get_CDR_enum;
 415         patable.p_get_CDR_object                = get_CDR_object;
 416         patable.p_get_CDR_boolean               = get_CDR_boolean;
 417 #endif
 418
 419 #ifdef WIN32
 420         /*
 421          * On Windows, the data file directory is the installation
 422          * directory; the plugins are stored under it.
 423          *
 424          * Assume we're running the installed version of Ethereal;
 425          * on Windows, the data file directory is the directory
 426          * in which the Ethereal binary resides.
 427          */
 428         datafile_dir = get_datafile_dir();
 429         install_plugin_dir = g_malloc(strlen(datafile_dir) + strlen("plugins") +
 430             strlen(VERSION) + 3);
 431         sprintf(install_plugin_dir, "%s\\plugins\\%s", datafile_dir, VERSION);
 432
 433         /*
 434          * Make sure that pathname refers to a directory.
 435          */
 436         if (test_for_directory(install_plugin_dir) != 0) {
 437                 /*
 438                  * Either it doesn't refer to a directory or it
 439                  * refers to something that doesn't exist.
 440                  *
 441                  * Assume that means we're running, for example,
 442                  * a version of Ethereal we've built in a source
 443                  * directory, and fall back on the default
 444                  * installation directory, so you can put the plugins
 445                  * somewhere so they can be used with this version
 446                  * of Ethereal.
 447                  *
 448                  * XXX - should we, instead, have the Windows build
 449                  * procedure create a subdirectory of the "plugins"
 450                  * source directory, and copy the plugin DLLs there,
 451                  * so that you use the plugins from the build tree?
 452                  */
 453                 install_plugin_dir =
 454                     "C:\\Program Files\\Ethereal\\plugins\\" VERSION;
 455         }
 456
 457         /*
 458          * Scan that directory.
 459          */
 460         plugins_scan_dir(install_plugin_dir);
 461 #else
 462         /*
 463          * XXX - why not just scan "plugin_dir"?  That's where we
 464          * installed the plugins; if Ethereal isn't installed under
 465          * "/usr" or "/usr/local", why should we search for its plugins
 466          * there?
 467          */
 468         plugins_scan_dir(std_plug_dir);
 469         plugins_scan_dir(local_plug_dir);
 470         if ((strcmp(std_plug_dir, plugin_dir) != 0) &&
 471                 (strcmp(local_plug_dir, plugin_dir) != 0))
 472         {
 473             if (stat(plugin_dir, &plugin_dir_stat) == 0)
 474             {
 475                 /* check if plugin_dir is really different from std_dir and
 476                  * local_dir if they exist ! */
 477                 if (stat(std_plug_dir, &std_dir_stat) == 0)
 478                 {
 479                     if (stat(local_plug_dir, &local_dir_stat) == 0)
 480                     {
 481                         if ((plugin_dir_stat.st_dev != std_dir_stat.st_dev ||
 482                                     plugin_dir_stat.st_ino != std_dir_stat.st_ino) &&
 483                                 (plugin_dir_stat.st_dev != local_dir_stat.st_dev ||
 484                                  plugin_dir_stat.st_ino != local_dir_stat.st_ino))
 485                             plugins_scan_dir(plugin_dir);
 486                     }
 487                     else
 488                     {
 489                         if ((plugin_dir_stat.st_dev != std_dir_stat.st_dev ||
 490                                     plugin_dir_stat.st_ino != std_dir_stat.st_ino))
 491                             plugins_scan_dir(plugin_dir);
 492                     }
 493                 }
 494                 else if (stat(local_plug_dir, &local_dir_stat) == 0)
 495                 {
 496                     if ((plugin_dir_stat.st_dev != local_dir_stat.st_dev ||
 497                                 plugin_dir_stat.st_ino != local_dir_stat.st_ino))
 498                         plugins_scan_dir(plugin_dir);
 499                 }
 500                 else plugins_scan_dir(plugin_dir);
 501             }
 502         }
 503 #endif
 504         if (!user_plug_dir)
 505         {
 506             user_plug_dir = (gchar *)g_malloc(strlen(get_home_dir()) +
 507                                               strlen(PF_DIR) +
 508                                               strlen(PLUGINS_DIR_NAME) + 3);
 509             sprintf(user_plug_dir, "%s/%s/%s", get_home_dir(),
 510                     PF_DIR, PLUGINS_DIR_NAME);
 511         }
 512         plugins_scan_dir(user_plug_dir);
 513     }
 514 }
 515
 516 void
 517 register_all_plugin_handoffs(void)
 518 {
 519   plugin *pt_plug;
 520
 521   /*
 522    * For all new-style plugins, call the register-handoff routine.
 523    * This is called from "proto_init()"; it must be called after
 524    * "register_all_protocols()" and "init_plugins()" are called,
 525    * in case one plugin registers itself either with a built-in
 526    * dissector or with another plugin; we must first register all
 527    * dissectors, whether built-in or plugin, so their dissector tables
 528    * are initialized, and only then register all handoffs.
 529    *
 530    * We treat those protocols as always being enabled; they should
 531    * use the standard mechanism for enabling/disabling protocols, not
 532    * the plugin-specific mechanism.
 533    */
 534   for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 535     (pt_plug->reg_handoff)();
 536 }
 537 #endif