epan/plugins.c

   1 /* plugins.c
   2  * plugin routines
   3  *
   4  * $Id: plugins.c,v 1.26 2001/08/18 23:21:31 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 #ifdef WIN32
  74 #include <stdio.h>
  75 static gchar std_plug_dir[] = "C:\\Program Files\\Ethereal\\plugins\\" VERSION;
  76 #else
  77 static gchar std_plug_dir[] = "/usr/lib/ethereal/plugins/" VERSION;
  78 static gchar local_plug_dir[] = "/usr/local/lib/ethereal/plugins/" VERSION;
  79 #endif
  80 static gchar *user_plug_dir = NULL;
  81
  82 #define PLUGINS_DIR_NAME        "plugins"
  83
  84 /*
  85  * add a new plugin to the list
  86  * returns :
  87  * - 0 : OK
  88  * - ENOMEM : memory allocation problem
  89  * - EEXIST : the same plugin (i.e. name/version) was already registered.
  90  */
  91 static int
  92 add_plugin(void *handle, gchar *name, gchar *version,
  93            void (*reg_handoff)(void))
  94 {
  95     plugin *new_plug, *pt_plug;
  96
  97     pt_plug = plugin_list;
  98     if (!pt_plug) /* the list is empty */
  99     {
 100         new_plug = (plugin *)g_malloc(sizeof(plugin));
 101         if (new_plug == NULL) return ENOMEM;
 102         plugin_list = new_plug;
 103     }
 104     else
 105     {
 106         while (1)
 107         {
 108             /* check if the same name/version is already registered */
 109             if (!strcmp(pt_plug->name, name) &&
 110                 !strcmp(pt_plug->version, version))
 111             {
 112                 return EEXIST;
 113             }
 114
 115             /* we found the last plugin in the list */
 116             if (pt_plug->next == NULL) break;
 117
 118             pt_plug = pt_plug->next;
 119         }
 120         new_plug = (plugin *)g_malloc(sizeof(plugin));
 121         if (new_plug == NULL) return ENOMEM;
 122         pt_plug->next = new_plug;
 123     }
 124
 125     new_plug->handle = handle;
 126     new_plug->name = name;
 127     new_plug->version = version;
 128     new_plug->reg_handoff = reg_handoff;
 129     new_plug->next = NULL;
 130     return 0;
 131 }
 132
 133 /*
 134  * XXX - when we remove support for old-style plugins (which we should
 135  * probably do eventually, as all plugins should be written as new-style
 136  * ones), we may want to have "init_plugins()" merely save a pointer
 137  * to the plugin's "init" routine, just as we save a pointer to its
 138  * "reg_handoff" routine, and have a "register_all_plugins()" routine
 139  * to go through the list of plugins and call all of them.
 140  *
 141  * Then we'd have "epan_init()", or perhaps even something higher up
 142  * in the call tree, call "init_plugins()", and have "proto_init()"
 143  * call "register_all_plugins()" right after calling "register_all_protocols()";
 144  * this might be a bit cleaner.
 145  */
 146 static void
 147 plugins_scan_dir(const char *dirname)
 148 {
 149 #define FILENAME_LEN    1024
 150     gchar         *hack_path;       /* pathname used to construct lt_lib_ext */
 151     gchar         *lt_lib_ext;      /* extension for loadable modules */
 152     DIR           *dir;             /* scanned directory */
 153     struct dirent *file;            /* current file */
 154     gchar          filename[FILENAME_LEN];   /* current file name */
 155     GModule       *handle;          /* handle returned by dlopen */
 156     gchar         *name;
 157     gchar         *version;
 158     void         (*init)(void *);
 159     void         (*reg_handoff)(void);
 160     gchar         *dot;
 161     int            cr;
 162
 163     /*
 164      * We find the extension used on this platform for loadable modules
 165      * by the sneaky hack of calling "g_module_build_path" to build
 166      * the pathname for a module with an empty directory name and
 167      * empty module name, and then search for the last "." and use
 168      * everything from the last "." on.
 169      *
 170      * GLib 2.0 will probably define G_MODULE_SUFFIX as the extension
 171      * to use, but that's not checked into the GLib CVS tree yet,
 172      * and we can't use it on systems that don't have GLib 2.0.
 173      */
 174     hack_path = g_module_build_path("", "");
 175     lt_lib_ext = strrchr(hack_path, '.');
 176     if (lt_lib_ext == NULL)
 177     {
 178         /*
 179          * Does this mean there *is* no extension?  Assume so.
 180          *
 181          * XXX - the code below assumes that all loadable modules have
 182          * an extension....
 183          */
 184         lt_lib_ext = "";
 185     }
 186
 187     if ((dir = opendir(dirname)) != NULL)
 188     {
 189         while ((file = readdir(dir)) != NULL)
 190         {
 191             /* don't try to open "." and ".." */
 192             if (!(strcmp(file->d_name, "..") &&
 193                   strcmp(file->d_name, "."))) continue;
 194
 195             /* skip anything but files with lt_lib_ext */
 196             dot = strrchr(file->d_name, '.');
 197             if (dot == NULL || strcmp(dot, lt_lib_ext) != 0) continue;
 198
 199             snprintf(filename, FILENAME_LEN, "%s" G_DIR_SEPARATOR_S "%s",
 200                 dirname, file->d_name);
 201             if ((handle = g_module_open(filename, 0)) == NULL) continue;
 202             name = (gchar *)file->d_name;
 203             if (g_module_symbol(handle, "version", (gpointer*)&version) == FALSE)
 204             {
 205                 g_warning("The plugin %s has no version symbol", name);
 206                 g_module_close(handle);
 207                 continue;
 208             }
 209
 210             /*
 211              * Old-style dissectors don't have a "plugin_reg_handoff()"
 212              * routine; we no longer support them.
 213              *
 214              * New-style dissectors have one, because, otherwise, there's
 215              * no way for them to arrange that they ever be called.
 216              */
 217             if (g_module_symbol(handle, "plugin_reg_handoff",
 218                                          (gpointer*)&reg_handoff))
 219             {
 220                 /*
 221                  * We require it to have a "plugin_init()" routine.
 222                  */
 223                 if (!g_module_symbol(handle, "plugin_init", (gpointer*)&init))
 224                 {
 225                     g_warning("The plugin %s has a plugin_reg_handoff symbol but no plugin_init routine", name);
 226                     g_module_close(handle);
 227                     continue;
 228                 }
 229
 230                 /*
 231                  * We have a "plugin_reg_handoff()" routine, so we don't
 232                  * need the protocol, filter string, or dissector pointer.
 233                  */
 234                 if ((cr = add_plugin(handle, g_strdup(file->d_name), version,
 235                                      reg_handoff)))
 236                 {
 237                     if (cr == EEXIST)
 238                         fprintf(stderr, "The plugin %s, version %s\n"
 239                             "was found in multiple directories\n", name, version);
 240                     else
 241                         fprintf(stderr, "Memory allocation problem\n"
 242                             "when processing plugin %s, version %s\n",
 243                             name, version);
 244                     g_module_close(handle);
 245                     continue;
 246                 }
 247
 248                 /*
 249                  * Call its init routine.
 250                  */
 251 #ifdef PLUGINS_NEED_ADDRESS_TABLE
 252                 init(&patable);
 253 #else
 254                 init(NULL);
 255 #endif
 256             }
 257             else
 258             {
 259                 /*
 260                  * This is an old-style dissector; warn that it won't
 261                  * be used, as those aren't supported.
 262                  */
 263                 fprintf(stderr,
 264                     "The plugin %s, version %s is an old-style plugin;\n"
 265                     "Those are no longer supported.\n", name, version);
 266             }
 267         }
 268         closedir(dir);
 269     }
 270     g_free(hack_path);
 271 }
 272
 273 /*
 274  * init plugins
 275  */
 276 void
 277 init_plugins(const char *plugin_dir)
 278 {
 279 #ifdef WIN32
 280     char prog_pathname[_MAX_PATH+2];
 281     char *dir_end;
 282     size_t plugin_dir_len;
 283     char *plugin_dir;
 284 #else
 285     struct stat std_dir_stat, local_dir_stat, plugin_dir_stat;
 286 #endif
 287
 288     if (plugin_list == NULL)      /* ensure init_plugins is only run once */
 289     {
 290 #ifdef PLUGINS_NEED_ADDRESS_TABLE
 291         /* Intialize address table */
 292         patable.p_check_col                     = check_col;
 293         patable.p_col_clear                     = col_clear;
 294         patable.p_col_add_fstr                  = col_add_fstr;
 295         patable.p_col_append_fstr               = col_append_fstr;
 296         patable.p_col_add_str                   = col_add_str;
 297         patable.p_col_append_str                = col_append_str;
 298         patable.p_col_set_str                   = col_set_str;
 299
 300         patable.p_pi                            = &pi;
 301
 302         patable.p_proto_register_protocol       = proto_register_protocol;
 303         patable.p_proto_register_field_array    = proto_register_field_array;
 304         patable.p_proto_register_subtree_array  = proto_register_subtree_array;
 305
 306         patable.p_dissector_add                 = dissector_add;
 307         patable.p_dissector_delete              = dissector_delete;
 308
 309         patable.p_heur_dissector_add            = heur_dissector_add;
 310
 311         patable.p_register_dissector            = register_dissector;
 312         patable.p_find_dissector                = find_dissector;
 313         patable.p_call_dissector                = call_dissector;
 314
 315         patable.p_dissect_data                  = dissect_data;
 316
 317         patable.p_proto_is_protocol_enabled     = proto_is_protocol_enabled;
 318
 319         patable.p_proto_item_get_len            = proto_item_get_len;
 320         patable.p_proto_item_set_len            = proto_item_set_len;
 321         patable.p_proto_item_set_text           = proto_item_set_text;
 322         patable.p_proto_item_add_subtree        = proto_item_add_subtree;
 323         patable.p_proto_tree_add_item           = proto_tree_add_item;
 324         patable.p_proto_tree_add_item_hidden    = proto_tree_add_item_hidden;
 325         patable.p_proto_tree_add_protocol_format = proto_tree_add_protocol_format;
 326         patable.p_proto_tree_add_bytes          = proto_tree_add_bytes;
 327         patable.p_proto_tree_add_bytes_hidden   = proto_tree_add_bytes_hidden;
 328         patable.p_proto_tree_add_bytes_format   = proto_tree_add_bytes_format;
 329         patable.p_proto_tree_add_time           = proto_tree_add_time;
 330         patable.p_proto_tree_add_time_hidden    = proto_tree_add_time_hidden;
 331         patable.p_proto_tree_add_time_format    = proto_tree_add_time_format;
 332         patable.p_proto_tree_add_ipxnet         = proto_tree_add_ipxnet;
 333         patable.p_proto_tree_add_ipxnet_hidden  = proto_tree_add_ipxnet_hidden;
 334         patable.p_proto_tree_add_ipxnet_format  = proto_tree_add_ipxnet_format;
 335         patable.p_proto_tree_add_ipv4           = proto_tree_add_ipv4;
 336         patable.p_proto_tree_add_ipv4_hidden    = proto_tree_add_ipv4_hidden;
 337         patable.p_proto_tree_add_ipv4_format    = proto_tree_add_ipv4_format;
 338         patable.p_proto_tree_add_ipv6           = proto_tree_add_ipv6;
 339         patable.p_proto_tree_add_ipv6_hidden    = proto_tree_add_ipv6_hidden;
 340         patable.p_proto_tree_add_ipv6_format    = proto_tree_add_ipv6_format;
 341         patable.p_proto_tree_add_ether          = proto_tree_add_ether;
 342         patable.p_proto_tree_add_ether_hidden   = proto_tree_add_ether_hidden;
 343         patable.p_proto_tree_add_ether_format   = proto_tree_add_ether_format;
 344         patable.p_proto_tree_add_string         = proto_tree_add_string;
 345         patable.p_proto_tree_add_string_hidden  = proto_tree_add_string_hidden;
 346         patable.p_proto_tree_add_string_format  = proto_tree_add_string_format;
 347         patable.p_proto_tree_add_boolean        = proto_tree_add_boolean;
 348         patable.p_proto_tree_add_boolean_hidden = proto_tree_add_boolean_hidden;
 349         patable.p_proto_tree_add_boolean_format = proto_tree_add_boolean_format;
 350         patable.p_proto_tree_add_double         = proto_tree_add_double;
 351         patable.p_proto_tree_add_double_hidden  = proto_tree_add_double_hidden;
 352         patable.p_proto_tree_add_double_format  = proto_tree_add_double_format;
 353         patable.p_proto_tree_add_uint           = proto_tree_add_uint;
 354         patable.p_proto_tree_add_uint_hidden    = proto_tree_add_uint_hidden;
 355         patable.p_proto_tree_add_uint_format    = proto_tree_add_uint_format;
 356         patable.p_proto_tree_add_int            = proto_tree_add_int;
 357         patable.p_proto_tree_add_int_hidden     = proto_tree_add_int_hidden;
 358         patable.p_proto_tree_add_int_format     = proto_tree_add_int_format;
 359         patable.p_proto_tree_add_text           = proto_tree_add_text;
 360         patable.p_proto_tree_add_notext         = proto_tree_add_notext;
 361
 362         patable.p_tvb_new_subset                = tvb_new_subset;
 363
 364         patable.p_tvb_length                    = tvb_length;
 365         patable.p_tvb_length_remaining          = tvb_length_remaining;
 366         patable.p_tvb_bytes_exist               = tvb_bytes_exist;
 367         patable.p_tvb_offset_exists             = tvb_offset_exists;
 368         patable.p_tvb_reported_length           = tvb_reported_length;
 369         patable.p_tvb_reported_length_remaining = tvb_reported_length_remaining;
 370
 371         patable.p_tvb_get_guint8                = tvb_get_guint8;
 372
 373         patable.p_tvb_get_ntohs                 = tvb_get_ntohs;
 374         patable.p_tvb_get_ntoh24                = tvb_get_ntoh24;
 375         patable.p_tvb_get_ntohl                 = tvb_get_ntohl;
 376 #ifdef G_HAVE_GINT64
 377         patable.p_tvb_get_ntohll                = tvb_get_ntohll;
 378 #endif
 379
 380         patable.p_tvb_get_letohs                = tvb_get_letohs;
 381         patable.p_tvb_get_letoh24               = tvb_get_letoh24;
 382         patable.p_tvb_get_letohl                = tvb_get_letohl;
 383 #ifdef G_HAVE_GINT64
 384         patable.p_tvb_get_letohll               = tvb_get_letohll;
 385 #endif
 386
 387         patable.p_tvb_memcpy                    = tvb_memcpy;
 388         patable.p_tvb_memdup                    = tvb_memdup;
 389
 390         patable.p_tvb_get_ptr                   = tvb_get_ptr;
 391
 392         patable.p_tvb_find_guint8               = tvb_find_guint8;
 393         patable.p_tvb_pbrk_guint8               = tvb_pbrk_guint8;
 394
 395         patable.p_tvb_strnlen                   = tvb_strnlen;
 396
 397         patable.p_tvb_format_text               = tvb_format_text;
 398
 399         patable.p_tvb_get_nstringz              = tvb_get_nstringz;
 400         patable.p_tvb_get_nstringz0             = tvb_get_nstringz0;
 401
 402         patable.p_tvb_find_line_end             = tvb_find_line_end;
 403         patable.p_tvb_find_line_end_unquoted    = tvb_find_line_end_unquoted;
 404
 405         patable.p_tvb_strneql                   = tvb_strneql;
 406         patable.p_tvb_strncaseeql               = tvb_strncaseeql;
 407
 408         patable.p_tvb_bytes_to_str              = tvb_bytes_to_str;
 409
 410         patable.p_prefs_register_protocol       = prefs_register_protocol;
 411         patable.p_prefs_register_uint_preference = prefs_register_uint_preference;
 412         patable.p_prefs_register_bool_preference = prefs_register_bool_preference;
 413         patable.p_prefs_register_enum_preference = prefs_register_enum_preference;
 414
 415         patable.p_register_giop_user            = register_giop_user;
 416         patable.p_is_big_endian                 = is_big_endian;
 417         patable.p_get_CDR_string                = get_CDR_string;
 418         patable.p_get_CDR_ulong                 = get_CDR_ulong;
 419         patable.p_get_CDR_enum                  = get_CDR_enum;
 420         patable.p_get_CDR_object                = get_CDR_object;
 421         patable.p_get_CDR_boolean               = get_CDR_boolean;
 422 #endif
 423
 424 #ifdef WIN32
 425         /*
 426          * Scan the default installation directory.
 427          *
 428          * This may not, in fact, be where Ethereal is installed;
 429          * we check that directory later, but we check this directory
 430          * as well, so that if you're running the program from a
 431          * source directory in which you've built it, you still get
 432          * to see the plugins installed on your system.
 433          */
 434         plugins_scan_dir(std_plug_dir);
 435
 436         /*
 437          * Now attempt to get the full pathname of the currently running
 438          * program, and assume that might contain the pathname of the
 439          * directory in which Ethereal was installed.
 440          */
 441         if (GetModuleFileName(NULL, prog_pathname, sizeof prog_pathname) != 0) {
 442                 /*
 443                  * If the program is an installed version, the full pathname
 444                  * includes the pathname of the directory in which it was
 445                  * installed; get that directory's pathname, and construct
 446                  * from it the pathname of the directory in which the
 447                  * plugins were installed.
 448                  *
 449                  * First, find the last "\\" in the directory, as that
 450                  * marks the end of the directory pathname.
 451                  */
 452                 dir_end = strrchr(prog_pathname, '\\');
 453                 if (dir_end != NULL) {
 454                         /*
 455                          * Include the "\\" in the directory's pathname,
 456                          * as we'll be appending to that pathname.
 457                          */
 458                         dir_end++;
 459
 460                         /*
 461                          * Found it - now figure out how long the plugin
 462                          * directory pathname will be.
 463                          * It's the length of the directory pathname
 464                          * (dir_end - prog_pathname), plus the length of
 465                          * the plugin directory's relative pathname.
 466                          */
 467                         plugin_dir_len = (dir_end - prog_pathname) +
 468                             strlen("plugins\\"VERSION);
 469
 470                         /*
 471                          * Allocate a buffer for the plugin directory
 472                          * pathname, and construct it.
 473                          */
 474                         plugin_dir = g_malloc(plugin_dir_len + 1);
 475                         strncpy(plugin_dir, prog_pathname,
 476                             dir_end - prog_pathname);
 477                         strcpy(plugin_dir + (dir_end - prog_pathname),
 478                             "plugins\\"VERSION);
 479
 480                         /*
 481                          * Is it the same as the standard plugin directory?
 482                          * (Do a case-insensitive string comparison; this
 483                          * *is* Windows, after all.)
 484                          *
 485                          * XXX - is there another way to determine whether
 486                          * two pathnames refer to the same file?
 487                          */
 488                         if (g_strcasecmp(std_plug_dir, plugin_dir) != 0) {
 489                                 /*
 490                                  * It's a different directory - scan it.
 491                                  */
 492                                 plugins_scan_dir(plugin_dir);
 493                         }
 494                 }
 495         }
 496 #else
 497         /*
 498          * XXX - why not just scan "plugin_dir"?  That's where we
 499          * installed the plugins; if Ethereal isn't installed under
 500          * "/usr" or "/usr/local", why should we search for its plugins
 501          * there?
 502          */
 503         plugins_scan_dir(std_plug_dir);
 504         plugins_scan_dir(local_plug_dir);
 505         if ((strcmp(std_plug_dir, plugin_dir) != 0) &&
 506                 (strcmp(local_plug_dir, plugin_dir) != 0))
 507         {
 508             if (stat(plugin_dir, &plugin_dir_stat) == 0)
 509             {
 510                 /* check if plugin_dir is really different from std_dir and
 511                  * local_dir if they exist ! */
 512                 if (stat(std_plug_dir, &std_dir_stat) == 0)
 513                 {
 514                     if (stat(local_plug_dir, &local_dir_stat) == 0)
 515                     {
 516                         if ((plugin_dir_stat.st_dev != std_dir_stat.st_dev ||
 517                                     plugin_dir_stat.st_ino != std_dir_stat.st_ino) &&
 518                                 (plugin_dir_stat.st_dev != local_dir_stat.st_dev ||
 519                                  plugin_dir_stat.st_ino != local_dir_stat.st_ino))
 520                             plugins_scan_dir(plugin_dir);
 521                     }
 522                     else
 523                     {
 524                         if ((plugin_dir_stat.st_dev != std_dir_stat.st_dev ||
 525                                     plugin_dir_stat.st_ino != std_dir_stat.st_ino))
 526                             plugins_scan_dir(plugin_dir);
 527                     }
 528                 }
 529                 else if (stat(local_plug_dir, &local_dir_stat) == 0)
 530                 {
 531                     if ((plugin_dir_stat.st_dev != local_dir_stat.st_dev ||
 532                                 plugin_dir_stat.st_ino != local_dir_stat.st_ino))
 533                         plugins_scan_dir(plugin_dir);
 534                 }
 535                 else plugins_scan_dir(plugin_dir);
 536             }
 537         }
 538 #endif
 539         if (!user_plug_dir)
 540         {
 541             user_plug_dir = (gchar *)g_malloc(strlen(get_home_dir()) +
 542                                               strlen(PF_DIR) +
 543                                               strlen(PLUGINS_DIR_NAME) + 3);
 544             sprintf(user_plug_dir, "%s/%s/%s", get_home_dir(),
 545                     PF_DIR, PLUGINS_DIR_NAME);
 546         }
 547         plugins_scan_dir(user_plug_dir);
 548     }
 549 }
 550
 551 void
 552 register_all_plugin_handoffs(void)
 553 {
 554   plugin *pt_plug;
 555
 556   /*
 557    * For all new-style plugins, call the register-handoff routine.
 558    * This is called from "proto_init()"; it must be called after
 559    * "register_all_protocols()" and "init_plugins()" are called,
 560    * in case one plugin registers itself either with a built-in
 561    * dissector or with another plugin; we must first register all
 562    * dissectors, whether built-in or plugin, so their dissector tables
 563    * are initialized, and only then register all handoffs.
 564    *
 565    * We treat those protocols as always being enabled; they should
 566    * use the standard mechanism for enabling/disabling protocols, not
 567    * the plugin-specific mechanism.
 568    */
 569   for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
 570     (pt_plug->reg_handoff)();
 571 }
 572 #endif