2 * Definitions for packet disassembly structures and routines
6 * Wireshark - Network traffic analyzer
7 * By Gerald Combs <gerald@wireshark.org>
8 * Copyright 1998 Gerald Combs
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.
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.
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.
28 #include "wiretap/wtap.h"
33 #include "value_string.h"
34 #include "column_info.h"
35 #include "frame_data.h"
36 #include "packet_info.h"
37 #include "column-utils.h"
43 #endif /* __cplusplus */
45 #define hi_nibble(b) (((b) & 0xf0) >> 4)
46 #define lo_nibble(b) ((b) & 0x0f)
48 /* Useful when you have an array whose size you can tell at compile-time */
49 #define array_length(x) (sizeof x / sizeof x[0])
51 /* Check whether the "len" bytes of data starting at "offset" is
52 * entirely inside the captured data for this packet. */
53 #define BYTES_ARE_IN_FRAME(offset, captured_len, len) \
54 ((guint)(offset) + (guint)(len) > (guint)(offset) && \
55 (guint)(offset) + (guint)(len) <= (guint)(captured_len))
57 /* To pass one of two strings, singular or plural */
58 #define plurality(d,s,p) ((d) == 1 ? (s) : (p))
60 typedef struct _packet_counts {
75 /** Number of packet counts. */
76 #define PACKET_COUNTS_SIZE sizeof(packet_counts) / sizeof (gint)
78 /* Types of character encodings */
80 CHAR_ASCII = 0, /* ASCII */
81 CHAR_EBCDIC = 1 /* EBCDIC */
84 extern void packet_init(void);
85 extern void packet_cleanup(void);
87 /* Handle for dissectors you call directly or register with "dissector_add()".
88 This handle is opaque outside of "packet.c". */
89 struct dissector_handle;
90 typedef struct dissector_handle *dissector_handle_t;
92 /* Hash table for matching port numbers and dissectors; this is opaque
93 outside of "packet.c". */
94 struct dissector_table;
95 typedef struct dissector_table *dissector_table_t;
98 * Dissector that returns nothing.
100 typedef void (*dissector_t)(tvbuff_t *, packet_info *, proto_tree *);
103 * Dissector that returns:
105 * The amount of data in the protocol's PDU, if it was able to
106 * dissect all the data;
108 * 0, if the tvbuff doesn't contain a PDU for that protocol;
110 * The negative of the amount of additional data needed, if
111 * we need more data (e.g., from subsequent TCP segments) to
112 * dissect the entire PDU.
114 typedef int (*new_dissector_t)(tvbuff_t *, packet_info *, proto_tree *);
116 /** Type of a heuristic dissector, used in heur_dissector_add().
118 * @param tvb the tv_buff with the (remaining) packet data
119 * @param pinfo the packet info of this packet (additional info)
120 * @param tree the protocol tree to be build or NULL
121 * @return TRUE if the packet was recognized by the sub-dissector (stop dissection here)
123 typedef gboolean (*heur_dissector_t)(tvbuff_t *tvb, packet_info *pinfo,
126 typedef void (*DATFunc) (const gchar *table_name, ftenum_t selector_type,
127 gpointer key, gpointer value, gpointer user_data);
128 typedef void (*DATFunc_handle) (const gchar *table_name, gpointer value,
130 typedef void (*DATFunc_table) (const gchar *table_name, const gchar *ui_name,
133 /* Opaque structure - provides type checking but no access to components */
134 typedef struct dtbl_entry dtbl_entry_t;
136 extern dissector_handle_t dtbl_entry_get_handle (dtbl_entry_t *dtbl_entry);
137 extern dissector_handle_t dtbl_entry_get_initial_handle (dtbl_entry_t * entry);
138 extern void dissector_table_foreach_changed (const char *name, DATFunc func,
140 extern void dissector_table_foreach (const char *name, DATFunc func,
142 extern void dissector_all_tables_foreach_changed (DATFunc func,
144 extern void dissector_table_foreach_handle(const char *name, DATFunc_handle func,
146 extern void dissector_all_tables_foreach_table (DATFunc_table func,
149 /* a protocol uses the function to register a sub-dissector table */
150 extern dissector_table_t register_dissector_table(const char *name,
151 const char *ui_name, ftenum_t type, int base);
153 /* Find a dissector table by table name. */
154 extern dissector_table_t find_dissector_table(const char *name);
156 /* Get the UI name for a sub-dissector table, given its internal name */
157 extern const char *get_dissector_table_ui_name(const char *name);
159 /* Get the field type for values of the selector for a dissector table,
160 given the table's internal name */
161 extern ftenum_t get_dissector_table_selector_type(const char *name);
163 /* Get the base to use when displaying values of the selector for a
164 sub-dissector table, given the table's internal name */
165 extern int get_dissector_table_base(const char *name);
167 /* Add an entry to a uint dissector table. */
168 extern void dissector_add(const char *abbrev, guint32 pattern,
169 dissector_handle_t handle);
171 /* Delete the entry for a dissector in a uint dissector table
172 with a particular pattern. */
173 extern void dissector_delete(const char *name, guint32 pattern,
174 dissector_handle_t handle);
176 /* Change the entry for a dissector in a uint dissector table
177 with a particular pattern to use a new dissector handle. */
178 extern void dissector_change(const char *abbrev, guint32 pattern,
179 dissector_handle_t handle);
181 /* Reset an entry in a uint dissector table to its initial value. */
182 extern void dissector_reset(const char *name, guint32 pattern);
184 /* Look for a given value in a given uint dissector table and, if found,
185 call the dissector with the arguments supplied, and return TRUE,
186 otherwise return FALSE. */
187 extern gboolean dissector_try_port(dissector_table_t sub_dissectors,
188 guint32 port, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
190 /* Look for a given value in a given uint dissector table and, if found,
191 return the dissector handle for that value. */
192 extern dissector_handle_t dissector_get_port_handle(
193 dissector_table_t sub_dissectors, guint32 port);
195 /* Add an entry to a string dissector table. */
196 extern void dissector_add_string(const char *name, const gchar *pattern,
197 dissector_handle_t handle);
199 /* Delete the entry for a dissector in a string dissector table
200 with a particular pattern. */
201 extern void dissector_delete_string(const char *name, const gchar *pattern,
202 dissector_handle_t handle);
204 /* Change the entry for a dissector in a string dissector table
205 with a particular pattern to use a new dissector handle. */
206 extern void dissector_change_string(const char *name, gchar *pattern,
207 dissector_handle_t handle);
209 /* Reset an entry in a string sub-dissector table to its initial value. */
210 extern void dissector_reset_string(const char *name, const gchar *pattern);
212 /* Look for a given string in a given dissector table and, if found, call
213 the dissector with the arguments supplied, and return TRUE, otherwise
215 extern gboolean dissector_try_string(dissector_table_t sub_dissectors,
216 const gchar *string, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
218 /* Look for a given value in a given string dissector table and, if found,
219 return the dissector handle for that value. */
220 extern dissector_handle_t dissector_get_string_handle(
221 dissector_table_t sub_dissectors, const gchar *string);
223 /* Add a handle to the list of handles that *could* be used with this
224 table. That list is used by code in the UI. */
225 extern void dissector_add_handle(const char *name, dissector_handle_t handle);
227 /* List of "heuristic" dissectors (which get handed a packet, look at it,
228 and either recognize it as being for their protocol, dissect it, and
229 return TRUE, or don't recognize it and return FALSE) to be called
230 by another dissector. */
231 typedef GSList *heur_dissector_list_t;
233 /** A protocol uses this function to register a heuristic sub-dissector list.
234 * Call this in the parent dissectors proto_register function.
236 * @param name the name of this protocol
237 * @param list the list of heuristic sub-dissectors to be registered
239 extern void register_heur_dissector_list(const char *name,
240 heur_dissector_list_t *list);
242 /** Try all the dissectors in a given heuristic dissector list. This is done,
243 * until we find one that recognizes the protocol.
244 * Call this while the parent dissector running.
246 * @param sub_dissectors the sub-dissector list
247 * @param tvb the tv_buff with the (remaining) packet data
248 * @param pinfo the packet info of this packet (additional info)
249 * @param tree the protocol tree to be build or NULL
250 * @return TRUE if the packet was recognized by the sub-dissector (stop dissection here)
252 extern gboolean dissector_try_heuristic(heur_dissector_list_t sub_dissectors,
253 tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
255 /** Add a sub-dissector to a heuristic dissector list.
256 * Call this in the proto_handoff function of the sub-dissector.
258 * @param name the name of the "parent" protocol, e.g. "tcp"
259 * @param dissector the sub-dissector to be registered
260 * @param proto the protocol id of the sub-dissector
262 extern void heur_dissector_add(const char *name, heur_dissector_t dissector,
265 /** Remove a sub-dissector from a heuristic dissector list.
266 * Call this in the prefs_reinit function of the sub-dissector.
268 * @param name the name of the "parent" protocol, e.g. "tcp"
269 * @param dissector the sub-dissector to be unregistered
270 * @param proto the protocol id of the sub-dissector
272 extern void heur_dissector_delete(const char *name, heur_dissector_t dissector, int proto);
274 /* Register a dissector. */
275 extern void register_dissector(const char *name, dissector_t dissector,
277 extern void new_register_dissector(const char *name, new_dissector_t dissector,
280 /* Get the short name of the protocol for a dissector handle. */
281 extern const char *dissector_handle_get_short_name(dissector_handle_t handle);
283 /* Get the index of the protocol for a dissector handle. */
284 extern int dissector_handle_get_protocol_index(dissector_handle_t handle);
286 /* Find a dissector by name. */
287 extern dissector_handle_t find_dissector(const char *name);
289 /* Create an anonymous handle for a dissector. */
290 extern dissector_handle_t create_dissector_handle(dissector_t dissector,
292 extern dissector_handle_t new_create_dissector_handle(new_dissector_t dissector,
295 /* Call a dissector through a handle and if no dissector was found
296 * pass if over to the "data" dissector instead.
298 * @param handle The dissector to call.
299 * @param tvb The buffer to dissect.
300 * @param pinfo Packet Info.
301 * @param tree The protocol tree.
302 * @return If the protocol for that handle isn't enabled call the data
303 * dissector. Otherwise, if the handle refers to a new-style
304 * dissector, call the dissector and return its return value, otherwise call
305 * it and return the length of the tvbuff pointed to by the argument.
307 extern int call_dissector(dissector_handle_t handle, tvbuff_t *tvb,
308 packet_info *pinfo, proto_tree *tree);
310 /* Call a dissector through a handle but if no dissector was found
311 * just return 0 and do not call the "data" dissector instead.
313 * @param handle The dissector to call.
314 * @param tvb The buffer to dissect.
315 * @param pinfo Packet Info.
316 * @param tree The protocol tree.
317 * @return If the protocol for that handle isn't enabled, return 0 without
318 * calling the dissector. Otherwise, if the handle refers to a new-style
319 * dissector, call the dissector and return its return value, otherwise call
320 * it and return the length of the tvbuff pointed to by the argument.
322 extern int call_dissector_only(dissector_handle_t handle, tvbuff_t *tvb,
323 packet_info *pinfo, proto_tree *tree);
325 /* Do all one-time initialization. */
326 extern void dissect_init(void);
328 extern void dissect_cleanup(void);
331 * Given a tvbuff, and a length from a packet header, adjust the length
332 * of the tvbuff to reflect the specified length.
334 extern void set_actual_length(tvbuff_t *tvb, guint specified_len);
336 /* Allow protocols to register "init" routines, which are called before
337 we make a pass through a capture file and dissect all its packets
338 (e.g., when we read in a new capture file, or run a "filter packets"
339 or "colorize packets" pass over the current capture file). */
340 extern void register_init_routine(void (*func)(void));
342 /* Initialize all data structures used for dissection. */
343 extern void init_dissection(void);
345 /* Free data structures allocated for dissection. */
346 extern void cleanup_dissection(void);
348 /* Allow protocols to register a "cleanup" routine to be
349 * run after the initial sequential run through the packets.
350 * Note that the file can still be open after this; this is not
351 * the final cleanup. */
352 extern void register_postseq_cleanup_routine(void (*func)(void));
354 /* Call all the registered "postseq_cleanup" routines. */
355 extern void postseq_cleanup_all_protocols(void);
357 /* Allow dissectors to register a "final_registration" routine
358 * that is run like the proto_register_XXX() routine, but the end
359 * end of the epan_init() function; that is, *after* all other
360 * subsystems, liked dfilters, have finished initializing. This is
361 * useful for dissector registration routines which need to compile
362 * display filters. dfilters can't initialize itself until all protocols
363 * have registereed themselvs. */
365 register_final_registration_routine(void (*func)(void));
367 /* Call all the registered "final_registration" routines. */
369 final_registration_all_protocols(void);
372 * Add a new data source to the list of data sources for a frame, given
373 * the tvbuff for the data source and its name.
375 extern void add_new_data_source(packet_info *pinfo, tvbuff_t *tvb,
379 * Free up a frame's list of data sources.
381 extern void free_data_sources(packet_info *pinfo);
384 * Dissectors should never modify the packet data.
386 extern void dissect_packet(epan_dissect_t *edt,
387 union wtap_pseudo_header *pseudo_header, const guchar *pd,
388 frame_data *fd, column_info *cinfo);
390 /* These functions are in packet-ethertype.c */
391 extern void capture_ethertype(guint16 etype, const guchar *pd, int offset,
392 int len, packet_counts *ld);
393 extern void ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_ethertype,
394 packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
395 int etype_id, int trailer_id, int fcs_len);
398 * Dump layer/selector/dissector records in a fashion similar to the
399 * proto_registrar_dump_* routines.
401 extern void dissector_dump_decodes(void);
404 * post dissectors are to be called by packet-frame.c after every other
405 * dissector has been called.
407 extern void register_postdissector(dissector_handle_t);
408 extern void call_all_postdissectors(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
412 #endif /* __cplusplus */
414 #endif /* packet.h */