epan/plugins.c

   1 /* plugins.c
   2  * plugin routines
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24
  25 #include "config.h"
  26
  27 #include "plugins.h"
  28 #include <stdio.h>
  29
  30 /* linked list of Lua plugins */
  31 wslua_plugin *wslua_plugin_list = NULL;
  32
  33 #ifdef HAVE_PLUGINS
  34
  35 #include <time.h>
  36
  37 #ifdef HAVE_DIRENT_H
  38 #include <dirent.h>
  39 #endif
  40
  41 #ifdef HAVE_DIRECT_H
  42 #include <direct.h>
  43 #endif
  44
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <errno.h>
  48
  49 #ifdef HAVE_UNISTD_H
  50 #include <unistd.h>
  51 #endif
  52
  53 #include "filesystem.h"
  54 #include <wsutil/privileges.h>
  55 #include <wsutil/file_util.h>
  56 #include <wsutil/report_err.h>
  57
  58 /* linked list of all plugins */
  59 plugin *plugin_list = NULL;
  60
  61 static void register_all_wiretap_modules(void);
  62 static void register_all_codecs(void);
  63
  64 /*
  65  * add a new plugin to the list
  66  * returns :
  67  * - 0 : OK
  68  * - ENOMEM : memory allocation problem
  69  * - EEXIST : the same plugin (i.e. name/version) was already registered.
  70  */
  71 static int
  72 add_plugin(void *handle, gchar *name, gchar *version,
  73            void (*register_protoinfo)(void),
  74            void (*reg_handoff)(void),
  75            void (*register_tap_listener)(void),
  76            void (*register_wtap_module)(void),
  77            void (*register_codec_module)(void))
  78 {
  79     plugin *new_plug, *pt_plug;
  80
  81     pt_plug = plugin_list;
  82     if (!pt_plug) /* the list is empty */
  83     {
  84         new_plug = (plugin *)g_malloc(sizeof(plugin));
  85         if (new_plug == NULL)
  86             return ENOMEM;
  87         plugin_list = new_plug;
  88     }
  89     else
  90     {
  91         while (1)
  92         {
  93             /* check if the same name/version is already registered */
  94             if (!strcmp(pt_plug->name, name) &&
  95                 !strcmp(pt_plug->version, version))
  96             {
  97                 return EEXIST;
  98             }
  99
 100             /* we found the last plugin in the list */
 101             if (pt_plug->next == NULL)
 102                 break;
 103
 104             pt_plug = pt_plug->next;
 105         }
 106         new_plug = (plugin *)g_malloc(sizeof(plugin));
 107         if (new_plug == NULL)
 108             return ENOMEM;
 109         pt_plug->next = new_plug;
 110     }
 111
 112     new_plug->handle = (GModule *)handle;
 113     new_plug->name = name;
 114     new_plug->version = version;
 115     new_plug->register_protoinfo = register_protoinfo;
 116     new_plug->reg_handoff = reg_handoff;
 117     new_plug->register_tap_listener = register_tap_listener;
 118     new_plug->register_wtap_module = register_wtap_module;
 119     new_plug->register_codec_module = register_codec_module;
 120     new_plug->next = NULL;
 121
 122     return 0;
 123 }
 124
 125 /*
 126  * XXX - when we remove support for old-style plugins (which we should
 127  * probably do eventually, as all plugins should be written as new-style
 128  * ones), we may want to have "init_plugins()" merely save a pointer
 129  * to the plugin's "init" routine, just as we save a pointer to its
 130  * "reg_handoff" routine, and have a "register_all_plugins()" routine
 131  * to go through the list of plugins and call all of them.
 132  *
 133  * Then we'd have "epan_init()", or perhaps even something higher up
 134  * in the call tree, call "init_plugins()", and have "proto_init()"
 135  * call "register_all_plugins()" right after calling "register_all_protocols()";
 136  * this might be a bit cleaner.
 137  */
 138 static void
 139 plugins_scan_dir(const char *dirname)
 140 {
 141 #define FILENAME_LEN        1024
 142     WS_DIR        *dir;             /* scanned directory */
 143     WS_DIRENT     *file;            /* current file */
 144     const char    *name;
 145     gchar          filename[FILENAME_LEN];   /* current file name */
 146     GModule       *handle;          /* handle returned by g_module_open */
 147     gchar         *version;
 148     gpointer       gp;
 149     void         (*register_protoinfo)(void);
 150     void         (*reg_handoff)(void);
 151     void         (*register_tap_listener)(void);
 152     void         (*register_wtap_module)(void);
 153     void         (*register_codec_module)(void);
 154
 155     gchar         *dot;
 156     int            cr;
 157
 158     if ((dir = ws_dir_open(dirname, 0, NULL)) != NULL)
 159     {
 160         while ((file = ws_dir_read_name(dir)) != NULL)
 161         {
 162             name = ws_dir_get_name(file);
 163
 164             /*
 165              * GLib 2.x defines G_MODULE_SUFFIX as the extension used on
 166              * this platform for loadable modules.
 167              */
 168             /* skip anything but files with G_MODULE_SUFFIX */
 169             dot = strrchr(name, '.');
 170             if (dot == NULL || strcmp(dot+1, G_MODULE_SUFFIX) != 0)
 171                 continue;
 172
 173             g_snprintf(filename, FILENAME_LEN, "%s" G_DIR_SEPARATOR_S "%s",
 174                        dirname, name);
 175             if ((handle = g_module_open(filename, (GModuleFlags)0)) == NULL)
 176             {
 177                 report_failure("Couldn't load module %s: %s", filename,
 178                                g_module_error());
 179                 continue;
 180             }
 181
 182             if (!g_module_symbol(handle, "version", &gp))
 183             {
 184                 report_failure("The plugin %s has no version symbol", name);
 185                 g_module_close(handle);
 186                 continue;
 187             }
 188             version = (char *)gp;
 189
 190             /*
 191              * Do we have a register routine?
 192              */
 193             if (g_module_symbol(handle, "plugin_register", &gp))
 194             {
 195                 /*
 196                  * Yes - this plugin includes one or more dissectors.
 197                  */
 198                 register_protoinfo = (void (*)(void))gp;
 199             }
 200             else
 201             {
 202                 /*
 203                  * No - no dissectors.
 204                  */
 205                 register_protoinfo = NULL;
 206             }
 207
 208             /*
 209              * Do we have a reg_handoff routine?
 210              */
 211             if (g_module_symbol(handle, "plugin_reg_handoff", &gp))
 212             {
 213                 /*
 214                  * Yes.
 215                  */
 216                 reg_handoff = (void (*)(void))gp;
 217             }
 218             else
 219             {
 220                 /*
 221                  * No - that's OK even if we have dissectors, as long
 222                  * as the plugin registers by name *and* there's
 223                  * a caller looking for that name.
 224                  */
 225                 reg_handoff = NULL;
 226             }
 227
 228             /*
 229              * Do we have a register_tap_listener routine?
 230              */
 231             if (g_module_symbol(handle, "plugin_register_tap_listener", &gp))
 232             {
 233                 /*
 234                  * Yes - this plugin includes one or more taps.
 235                  */
 236                 register_tap_listener = (void (*)(void))gp;
 237             }
 238             else
 239             {
 240                 /*
 241                  * No - no taps here.
 242                  */
 243                 register_tap_listener = NULL;
 244             }
 245
 246             /*
 247              * Do we have an old-style init routine?
 248              */
 249             if (g_module_symbol(handle, "plugin_init", &gp))
 250             {
 251                 /*
 252                  * Yes - do we also have a register routine or a
 253                  * register_tap_listener routine?  If so, this is a bogus
 254                  * hybrid of an old-style and new-style plugin.
 255                  */
 256                 if (register_protoinfo != NULL || register_tap_listener != NULL)
 257                 {
 258                     report_failure("The plugin '%s' has an old plugin init routine\nand a new register or register_tap_listener routine.",
 259                                    name);
 260                     g_module_close(handle);
 261                     continue;
 262                 }
 263
 264                 /*
 265                  * It's just an unsupported old-style plugin;
 266                  */
 267                 report_failure("The plugin '%s' has an old plugin init routine. Support has been dropped.\n Information on how to update your plugin is available at \nhttp://anonsvn.wireshark.org/wireshark/trunk/doc/README.plugins",
 268                                name);
 269                 g_module_close(handle);
 270                 continue;
 271             }
 272
 273             /*
 274              * Do we have a register_wtap_module routine?
 275              */
 276             if (g_module_symbol(handle, "register_wtap_module", &gp))
 277             {
 278                 register_wtap_module = (void (*)(void))gp;
 279             }
 280             else
 281             {
 282                 register_wtap_module = NULL;
 283             }
 284
 285             /*
 286              * Do we have a register_codec_module routine?
 287              */
 288             if (g_module_symbol(handle, "register_codec_module", &gp))
 289             {
 290                 register_codec_module = (void (*)(void))gp;
 291             }
 292             else
 293             {
 294                 register_codec_module = NULL;
 295             }
 296
 297             /*
 298              * Does this dissector do anything useful?
 299              */
 300             if (register_protoinfo == NULL &&
 301                 register_tap_listener == NULL &&
 302                 register_wtap_module == NULL &&
 303                 register_codec_module == NULL )
 304             {
 305                 /*
 306                  * No.
 307                  */
 308                 report_failure("The plugin '%s' has neither a register routine, "
 309                                "a register_tap_listener or a register_wtap_module or a register_codec_module routine",
 310                                name);
 311                 g_module_close(handle);
 312                 continue;
 313             }
 314
 315             /*
 316              * OK, attempt to add it to the list of plugins.
 317              */
 318             if ((cr = add_plugin(handle, g_strdup(name), version,
 319                                  register_protoinfo, reg_handoff,
 320                                  register_tap_listener,register_wtap_module,register_codec_module)))
 321             {
 322                 if (cr == EEXIST)
 323                     fprintf(stderr, "The plugin %s, version %s\n"
 324                             "was found in multiple directories\n", name, version);
 325                 else
 326                     fprintf(stderr, "Memory allocation problem\n"
 327                             "when processing plugin %s, version %s\n",
 328                             name, version);
 329                 g_module_close(handle);
 330                 continue;
 331             }
 332
 333         }
 334         ws_dir_close(dir);
 335     }
 336 }
 337
 338
 339 /*
 340  * init plugins
 341  */
 342 void
 343 init_plugins(void)
 344 {
 345     const char *plugin_dir;
 346     const char *name;
 347     char *plugin_dir_path;
 348     char *plugins_pers_dir;
 349     WS_DIR *dir;                /* scanned directory */
 350     WS_DIRENT *file;                /* current file */
 351
 352     if (plugin_list == NULL)      /* ensure init_plugins is only run once */
 353     {
 354         /*
 355          * Scan the global plugin directory.
 356          * If we're running from a build directory, scan the subdirectories
 357          * of that directory, as the global plugin directory is the
 358          * "plugins" directory of the source tree, and the subdirectories
 359          * are the source directories for the plugins, with the plugins
 360          * built in those subdirectories.
 361          */
 362         plugin_dir = get_plugin_dir();
 363         if (running_in_build_directory())
 364         {
 365             if ((dir = ws_dir_open(plugin_dir, 0, NULL)) != NULL)
 366             {
 367                 while ((file = ws_dir_read_name(dir)) != NULL)
 368                 {
 369                     name = ws_dir_get_name(file);
 370                     if (strcmp(name, ".") == 0 || strcmp(name, "..") == 0)
 371                         continue;        /* skip "." and ".." */
 372                     /*
 373                      * Get the full path of a ".libs" subdirectory of that
 374                      * directory.
 375                      */
 376                     plugin_dir_path = g_strdup_printf(
 377                         "%s" G_DIR_SEPARATOR_S "%s" G_DIR_SEPARATOR_S ".libs",
 378                         plugin_dir, name);
 379                     if (test_for_directory(plugin_dir_path) != EISDIR) {
 380                         /*
 381                          * Either it doesn't refer to a directory or it
 382                          * refers to something that doesn't exist.
 383                          *
 384                          * Assume that means that the plugins are in
 385                          * the subdirectory of the plugin directory, not
 386                          * a ".libs" subdirectory of that subdirectory.
 387                          */
 388                         g_free(plugin_dir_path);
 389                         plugin_dir_path = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
 390                             plugin_dir, name);
 391                     }
 392                     plugins_scan_dir(plugin_dir_path);
 393                     g_free(plugin_dir_path);
 394                 }
 395                 ws_dir_close(dir);
 396             }
 397         }
 398         else
 399             plugins_scan_dir(plugin_dir);
 400
 401         /*
 402          * If the program wasn't started with special privileges,
 403          * scan the users plugin directory.  (Even if we relinquish
 404          * them, plugins aren't safe unless we've *permanently*
 405          * relinquished them, and we can't do that in Wireshark as,
 406          * if we need privileges to start capturing, we'd need to
 407          * reclaim them before each time we start capturing.)
 408          */
 409         if (!started_with_special_privs())
 410         {
 411             plugins_pers_dir = get_plugins_pers_dir();
 412             plugins_scan_dir(plugins_pers_dir);
 413             g_free(plugins_pers_dir);
 414         }
 415     }
 416
 417     register_all_wiretap_modules();
 418     register_all_codecs();
 419 }
 420
 421 void
 422 register_all_plugin_registrations(void)
 423 {
 424     plugin *pt_plug;
 425
 426     /*
 427      * For all plugins with register-handoff routines, call the routines.
 428      * This is called from "proto_init()"; it must be called after
 429      * "register_all_protocols()" and "init_plugins()" are called,
 430      * in case one plugin registers itself either with a built-in
 431      * dissector or with another plugin; we must first register all
 432      * dissectors, whether built-in or plugin, so their dissector tables
 433      * are initialized, and only then register all handoffs.
 434      */
 435     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 436     {
 437         if (pt_plug->register_protoinfo)
 438             (pt_plug->register_protoinfo)();
 439     }
 440 }
 441
 442 void
 443 register_all_plugin_handoffs(void)
 444 {
 445     plugin *pt_plug;
 446
 447     /*
 448      * For all plugins with register-handoff routines, call the routines.
 449      * This is called from "proto_init()"; it must be called after
 450      * "register_all_protocols()" and "init_plugins()" are called,
 451      * in case one plugin registers itself either with a built-in
 452      * dissector or with another plugin; we must first register all
 453      * dissectors, whether built-in or plugin, so their dissector tables
 454      * are initialized, and only then register all handoffs.
 455      */
 456     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 457     {
 458         if (pt_plug->reg_handoff)
 459             (pt_plug->reg_handoff)();
 460     }
 461 }
 462
 463 void
 464 register_all_plugin_tap_listeners(void)
 465 {
 466     plugin *pt_plug;
 467
 468     /*
 469      * For all plugins with register-tap-listener routines, call the
 470      * routines.
 471      */
 472     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 473     {
 474         if (pt_plug->register_tap_listener)
 475             (pt_plug->register_tap_listener)();
 476     }
 477 }
 478
 479 static void
 480 register_all_wiretap_modules(void)
 481 {
 482     plugin *pt_plug;
 483
 484     /*
 485      * For all plugins with register_wtap_module routines, call the
 486      * routines.
 487      */
 488     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 489     {
 490         if (pt_plug->register_wtap_module)
 491             (pt_plug->register_wtap_module)();
 492     }
 493 }
 494
 495 static void
 496 register_all_codecs(void)
 497 {
 498     plugin *pt_plug;
 499
 500     /*
 501      * For all plugins with register_wtap_module routines, call the
 502      * routines.
 503      */
 504     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 505     {
 506         if (pt_plug->register_codec_module)
 507               (pt_plug->register_codec_module)();
 508     }
 509 }
 510
 511 #endif  /* big HAVE_PLUGINS */
 512
 513 /*
 514  * Dump plugin info to stdout. Copied from ui/gtk/plugins_dlg.c:plugins_scan.
 515  */
 516 void
 517 plugins_dump_all(void)
 518 {
 519 #ifdef HAVE_PLUGINS
 520     plugin     *pt_plug;
 521     const char *sep;
 522 #endif
 523 #ifdef HAVE_LUA
 524     wslua_plugin  *lua_plug;
 525 #endif
 526
 527 #ifdef HAVE_PLUGINS
 528     for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 529     {
 530         sep = "";
 531
 532         printf("%s\t%s\t", pt_plug->name, pt_plug->version);
 533         if (pt_plug->register_protoinfo)
 534         {
 535             printf("dissector");
 536             sep = ", ";
 537         }
 538         if (pt_plug->register_tap_listener)
 539         {
 540             printf("%stap", sep);
 541             sep = ", ";
 542         }
 543         if (pt_plug->register_wtap_module)
 544         {
 545             printf("%sfile format", sep);
 546             sep = ", ";
 547         }
 548         if (pt_plug->register_codec_module)
 549         {
 550             printf("%scodec", sep);
 551         }
 552         printf("\t%s\n", g_module_name(pt_plug->handle));
 553     }
 554 #endif
 555
 556 #ifdef HAVE_LUA
 557     for (lua_plug = wslua_plugin_list; lua_plug != NULL; lua_plug = lua_plug->next)
 558     {
 559         printf("%s\t%s\tlua script\t%s\n", lua_plug->name, lua_plug->version, lua_plug->filename);
 560     }
 561 #endif
 562 }
 563