2 * packet tap interface 2002 Ronnie Sahlberg
4 * Wireshark - Network traffic analyzer
5 * By Gerald Combs <gerald@wireshark.org>
6 * Copyright 1998 Gerald Combs
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <epan/epan.h>
27 #include "ws_symbol_export.h"
31 #endif /* __cplusplus */
33 typedef void (*tap_reset_cb)(void *tapdata);
34 typedef gboolean (*tap_packet_cb)(void *tapdata, packet_info *pinfo, epan_dissect_t *edt, const void *data);
35 typedef void (*tap_draw_cb)(void *tapdata);
38 * Flags to indicate what a tap listener's packet routine requires.
40 #define TL_REQUIRES_NOTHING 0x00000000 /**< nothing */
41 #define TL_REQUIRES_PROTO_TREE 0x00000001 /**< full protocol tree */
42 #define TL_REQUIRES_COLUMNS 0x00000002 /**< columns */
43 #define TL_REQUIRES_ERROR_PACKETS 0x00000004 /**< include packet even if pinfo->flags.in_error_pkt is set */
44 /** Flags to indicate what the tap listener does */
45 #define TL_IS_DISSECTOR_HELPER 0x00000008 /**< tap helps a dissector do work
46 ** but does not, itself, require dissection */
49 /** Register tap plugin type with the plugin system.
50 Called by epan_register_plugin_types(); do not call it yourself. */
51 extern void register_tap_plugin_type(void);
55 * For all tap plugins, call their register routines.
56 * Must be called after init_plugins(), and must be called only once in
59 * XXX - should probably be handled by epan_init(), as the tap mechanism
60 * is part of libwireshark.
62 WS_DLL_PUBLIC void register_all_plugin_tap_listeners(void);
64 extern void tap_init(void);
66 /** This function registers that a dissector has the packet tap ability
67 * available. The name parameter is the name of this tap and extensions can
68 * use open_tap(char *name,... to specify that it wants to receive packets/
69 * events from this tap.
71 * This function is only to be called once, when the dissector initializes.
73 * The return value from this call is later used as a parameter to the
74 * tap_packet(unsigned int *tap_id,...
75 * call so that the tap subsystem knows to which tap point this tapped
76 * packet is associated.
78 WS_DLL_PUBLIC int register_tap(const char *name);
80 /* Gets a GList of the tap names */
81 WS_DLL_PUBLIC GList* get_tap_names(void);
83 /** This function will return the tap_id for the specific protocol tap
84 * or 0 if no such tap was found.
86 WS_DLL_PUBLIC int find_tap_id(const char *name);
88 /** Everytime the dissector has finished dissecting a packet (and all
89 * subdissectors have returned) and if the dissector has been made "tappable"
90 * it will push some data to everyone tapping this layer by a call
91 * to tap_queue_packet().
92 * The first parameter is the tap_id returned by the register_tap()
93 * call for this dissector (so the tap system can keep track of who it came
94 * from and who is listening to it)
95 * The second is the packet_info structure which many tap readers will find
97 * The third argument is specific to each tap point or NULL if no additional
98 * data is available to this tap. A tap point in say IP will probably want to
99 * push the IP header structure here. Same thing for TCP and ONCRPC.
101 * The pinfo and the specific pointer are what is supplied to every listener
102 * in the read_callback() call made to every one currently listening to this
105 * The tap reader is responsible to know how to parse any structure pointed
106 * to by the tap specific data pointer.
108 WS_DLL_PUBLIC void tap_queue_packet(int tap_id, packet_info *pinfo, const void *tap_specific_data);
110 /** Functions used by file.c to drive the tap subsystem */
111 WS_DLL_PUBLIC void tap_build_interesting(epan_dissect_t *edt);
113 /** This function is used to delete/initialize the tap queue and prime an
114 * epan_dissect_t with all the filters for tap listeners.
115 * To free the tap queue, we just prepend the used queue to the free queue.
117 extern void tap_queue_init(epan_dissect_t *edt);
119 /** this function is called after a packet has been fully dissected to push the tapped
120 * data to all extensions that has callbacks registered.
123 extern void tap_push_tapped_queue(epan_dissect_t *edt);
125 /** This function is called after a packet has been fully dissected to push the tapped
126 * data to all extensions that has callbacks registered.
129 WS_DLL_PUBLIC void reset_tap_listeners(void);
131 /** This function is called when we need to redraw all tap listeners, for example
132 * when we open/start a new capture or if we need to rescan the packet list.
133 * It should be called from a low priority thread say once every 3 seconds
135 * If draw_all is true, redraw all aplications regardless if they have
138 WS_DLL_PUBLIC void draw_tap_listeners(gboolean draw_all);
140 /** this function attaches the tap_listener to the named tap.
143 * non-NULL: error, return value points to GString containing error
145 * @param tapname The name of the tap we want to listen to.
146 * @param tapdata is the instance identifier. The tap system uses the value of this
147 * pointer to distinguish between different instances of a tap.
148 * Just make sure that it is unique by letting it be the pointer to a struct
149 * holding all state variables. If you want to allow multiple concurrent
150 * instances, just put ALL state variables inside a struct allocated by
151 * g_malloc() and use that pointer.
152 * @param fstring is a pointer to a filter string.
153 * If this is NULL, then the tap system will provide ALL packets passing the
154 * tapped protocol to your listener.
155 * If you specify a filter string here the tap system will first try
156 * to apply this string to the packet and then only pass those packets that
157 * matched the filter to your listener.
158 * The syntax for the filter string is identical to normal display filters.
160 * NOTE: Specifying filter strings will have a significant performance impact
161 * on your application and Wireshark. If possible it is MUCH better to take
162 * unfiltered data and just filter it yourself in the packet-callback than
163 * to specify a filter string.
164 * ONLY use a filter string if no other option exist.
166 * @param flags is a set of flags for the tap listener. The flags that can be set are:
168 * TL_REQUIRES_PROTO_TREE
170 * set if your tap listener "packet" routine requires a protocol
171 * tree to be built. It will require a protocol tree to be
174 * 1) it looks at the protocol tree in edt->tree
178 * 2) the tap-specific data passed to it is constructed only if
179 * the protocol tree is being built.
181 * TL_REQUIRES_COLUMNS
183 * set if your tap listener "packet" routine requires the column
184 * strings to be constructed.
186 * If no flags are needed, use TL_REQUIRES_NOTHING.
188 * @param tap_reset void (*reset)(void *tapdata)
189 * This callback is called whenever Wireshark wants to inform your
190 * listener that it is about to start [re]reading a capture file or a new capture
191 * from an interface and that your application should reset any state it has
192 * in the *tapdata instance.
193 * @param tap_packet gboolean (*packet)(void *tapdata, packet_info *pinfo, epan_dissect_t *edt, const void *data)
194 * This callback is used whenever a new packet has arrived at the tap and that
195 * it has passed the filter (if there were a filter).
196 * The *data structure type is specific to each tap.
197 * This function returns an gboolean and it should return
198 * TRUE, if the data in the packet caused state to be updated
199 * (and thus a redraw of the window would later be required)
200 * FALSE, if we don't need to redraw the window.
201 * NOTE: that (*packet) should be as fast and efficient as possible. Use this
202 * function ONLY to store data for later and do the CPU-intensive processing
203 * or GUI updates down in (*draw) instead.
204 * @param tap_draw void (*draw)(void *tapdata)
205 * This callback is used when Wireshark wants your application to redraw its
206 * output. It will usually not be called unless your application has received
207 * new data through the (*packet) callback.
208 * On some ports of Wireshark (gtk2) (*draw) will be called asynchronously
209 * from a separate thread up to once every 2-3 seconds.
210 * On other ports it might only be called once when the capture is finished
211 * or the file has been [re]read completely.
214 WS_DLL_PUBLIC GString *register_tap_listener(const char *tapname, void *tapdata,
215 const char *fstring, guint flags, tap_reset_cb tap_reset,
216 tap_packet_cb tap_packet, tap_draw_cb tap_draw);
218 /** This function sets a new dfilter to a tap listener */
219 WS_DLL_PUBLIC GString *set_tap_dfilter(void *tapdata, const char *fstring);
221 /** This function recompiles dfilter for all registered tap listeners */
222 WS_DLL_PUBLIC void tap_listeners_dfilter_recompile(void);
224 /** this function removes a tap listener */
225 WS_DLL_PUBLIC void remove_tap_listener(void *tapdata);
228 * Return TRUE if we have one or more tap listeners that require dissection,
231 WS_DLL_PUBLIC gboolean tap_listeners_require_dissection(void);
233 /** Returns TRUE there is an active tap listener for the specified tap id. */
234 WS_DLL_PUBLIC gboolean have_tap_listener(int tap_id);
236 /** Return TRUE if we have any tap listeners with filters, FALSE otherwise. */
237 WS_DLL_PUBLIC gboolean have_filtering_tap_listeners(void);
240 * Get the union of all the flags for all the tap listeners; that gives
241 * an indication of whether the protocol tree, or the columns, are
242 * required by any taps.
244 WS_DLL_PUBLIC guint union_of_tap_listener_flags(void);
246 /** This function can be used by a dissector to fetch any tapped data before
248 * This can be useful if one wants to extract the data inside dissector BEFORE
249 * it exists as an alternative to the callbacks that are all called AFTER the
250 * dissection has completed.
252 * Example: SMB2 uses this mechanism to extract the data tapped from NTLMSSP
253 * containing the account and domain names before exiting.
254 * Note that the SMB2 tap listener specifies all three callbacks as NULL.
256 * Beware: when using this mechanism to extract the tapped data you can not
257 * use "filters" and should specify the "filter" as NULL when registering
260 WS_DLL_PUBLIC const void *fetch_tapped_data(int tap_id, int idx);
264 #endif /* __cplusplus */
266 #endif /* __TAP_H__ */