/* tap.h * packet tap interface 2002 Ronnie Sahlberg * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef __TAP_H__ #define __TAP_H__ #include #include "ws_symbol_export.h" #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ typedef void (*tap_reset_cb)(void *tapdata); typedef gboolean (*tap_packet_cb)(void *tapdata, packet_info *pinfo, epan_dissect_t *edt, const void *data); typedef void (*tap_draw_cb)(void *tapdata); /** * Flags to indicate what a tap listener's packet routine requires. */ #define TL_REQUIRES_NOTHING 0x00000000 /**< nothing */ #define TL_REQUIRES_PROTO_TREE 0x00000001 /**< full protocol tree */ #define TL_REQUIRES_COLUMNS 0x00000002 /**< columns */ #define TL_REQUIRES_ERROR_PACKETS 0x00000004 /**< include packet even if pinfo->flags.in_error_pkt is set */ /** Flags to indicate what the tap listener does */ #define TL_IS_DISSECTOR_HELPER 0x00000008 /**< tap helps a dissector do work ** but does not, itself, require dissection */ #ifdef HAVE_PLUGINS /** Register tap plugin type with the plugin system. Called by epan_register_plugin_types(); do not call it yourself. */ extern void register_tap_plugin_type(void); #endif /* * For all tap plugins, call their register routines. * Must be called after init_plugins(), and must be called only once in * a program. * * XXX - should probably be handled by epan_init(), as the tap mechanism * is part of libwireshark. */ WS_DLL_PUBLIC void register_all_plugin_tap_listeners(void); extern void tap_init(void); /** This function registers that a dissector has the packet tap ability * available. The name parameter is the name of this tap and extensions can * use open_tap(char *name,... to specify that it wants to receive packets/ * events from this tap. * * This function is only to be called once, when the dissector initializes. * * The return value from this call is later used as a parameter to the * tap_packet(unsigned int *tap_id,... * call so that the tap subsystem knows to which tap point this tapped * packet is associated. */ WS_DLL_PUBLIC int register_tap(const char *name); /* Gets a GList of the tap names */ WS_DLL_PUBLIC GList* get_tap_names(void); /** This function will return the tap_id for the specific protocol tap * or 0 if no such tap was found. */ WS_DLL_PUBLIC int find_tap_id(const char *name); /** Everytime the dissector has finished dissecting a packet (and all * subdissectors have returned) and if the dissector has been made "tappable" * it will push some data to everyone tapping this layer by a call * to tap_queue_packet(). * The first parameter is the tap_id returned by the register_tap() * call for this dissector (so the tap system can keep track of who it came * from and who is listening to it) * The second is the packet_info structure which many tap readers will find * interesting. * The third argument is specific to each tap point or NULL if no additional * data is available to this tap. A tap point in say IP will probably want to * push the IP header structure here. Same thing for TCP and ONCRPC. * * The pinfo and the specific pointer are what is supplied to every listener * in the read_callback() call made to every one currently listening to this * tap. * * The tap reader is responsible to know how to parse any structure pointed * to by the tap specific data pointer. */ WS_DLL_PUBLIC void tap_queue_packet(int tap_id, packet_info *pinfo, const void *tap_specific_data); /** Functions used by file.c to drive the tap subsystem */ WS_DLL_PUBLIC void tap_build_interesting(epan_dissect_t *edt); /** This function is used to delete/initialize the tap queue and prime an * epan_dissect_t with all the filters for tap listeners. * To free the tap queue, we just prepend the used queue to the free queue. */ extern void tap_queue_init(epan_dissect_t *edt); /** this function is called after a packet has been fully dissected to push the tapped * data to all extensions that has callbacks registered. */ extern void tap_push_tapped_queue(epan_dissect_t *edt); /** This function is called after a packet has been fully dissected to push the tapped * data to all extensions that has callbacks registered. */ WS_DLL_PUBLIC void reset_tap_listeners(void); /** This function is called when we need to redraw all tap listeners, for example * when we open/start a new capture or if we need to rescan the packet list. * It should be called from a low priority thread say once every 3 seconds * * If draw_all is true, redraw all aplications regardless if they have * changed or not. */ WS_DLL_PUBLIC void draw_tap_listeners(gboolean draw_all); /** this function attaches the tap_listener to the named tap. * function returns : * NULL: ok. * non-NULL: error, return value points to GString containing error * message. * @param tapname The name of the tap we want to listen to. * @param tapdata is the instance identifier. The tap system uses the value of this * pointer to distinguish between different instances of a tap. * Just make sure that it is unique by letting it be the pointer to a struct * holding all state variables. If you want to allow multiple concurrent * instances, just put ALL state variables inside a struct allocated by * g_malloc() and use that pointer. * @param fstring is a pointer to a filter string. * If this is NULL, then the tap system will provide ALL packets passing the * tapped protocol to your listener. * If you specify a filter string here the tap system will first try * to apply this string to the packet and then only pass those packets that * matched the filter to your listener. * The syntax for the filter string is identical to normal display filters. * * NOTE: Specifying filter strings will have a significant performance impact * on your application and Wireshark. If possible it is MUCH better to take * unfiltered data and just filter it yourself in the packet-callback than * to specify a filter string. * ONLY use a filter string if no other option exist. * * @param flags is a set of flags for the tap listener. The flags that can be set are: * * TL_REQUIRES_PROTO_TREE * * set if your tap listener "packet" routine requires a protocol * tree to be built. It will require a protocol tree to be * built if either * * 1) it looks at the protocol tree in edt->tree * * or * * 2) the tap-specific data passed to it is constructed only if * the protocol tree is being built. * * TL_REQUIRES_COLUMNS * * set if your tap listener "packet" routine requires the column * strings to be constructed. * * If no flags are needed, use TL_REQUIRES_NOTHING. * * @param tap_reset void (*reset)(void *tapdata) * This callback is called whenever Wireshark wants to inform your * listener that it is about to start [re]reading a capture file or a new capture * from an interface and that your application should reset any state it has * in the *tapdata instance. * @param tap_packet gboolean (*packet)(void *tapdata, packet_info *pinfo, epan_dissect_t *edt, const void *data) * This callback is used whenever a new packet has arrived at the tap and that * it has passed the filter (if there were a filter). * The *data structure type is specific to each tap. * This function returns an gboolean and it should return * TRUE, if the data in the packet caused state to be updated * (and thus a redraw of the window would later be required) * FALSE, if we don't need to redraw the window. * NOTE: that (*packet) should be as fast and efficient as possible. Use this * function ONLY to store data for later and do the CPU-intensive processing * or GUI updates down in (*draw) instead. * @param tap_draw void (*draw)(void *tapdata) * This callback is used when Wireshark wants your application to redraw its * output. It will usually not be called unless your application has received * new data through the (*packet) callback. * On some ports of Wireshark (gtk2) (*draw) will be called asynchronously * from a separate thread up to once every 2-3 seconds. * On other ports it might only be called once when the capture is finished * or the file has been [re]read completely. */ WS_DLL_PUBLIC GString *register_tap_listener(const char *tapname, void *tapdata, const char *fstring, guint flags, tap_reset_cb tap_reset, tap_packet_cb tap_packet, tap_draw_cb tap_draw); /** This function sets a new dfilter to a tap listener */ WS_DLL_PUBLIC GString *set_tap_dfilter(void *tapdata, const char *fstring); /** This function recompiles dfilter for all registered tap listeners */ WS_DLL_PUBLIC void tap_listeners_dfilter_recompile(void); /** this function removes a tap listener */ WS_DLL_PUBLIC void remove_tap_listener(void *tapdata); /** * Return TRUE if we have one or more tap listeners that require dissection, * FALSE otherwise. */ WS_DLL_PUBLIC gboolean tap_listeners_require_dissection(void); /** Returns TRUE there is an active tap listener for the specified tap id. */ WS_DLL_PUBLIC gboolean have_tap_listener(int tap_id); /** Return TRUE if we have any tap listeners with filters, FALSE otherwise. */ WS_DLL_PUBLIC gboolean have_filtering_tap_listeners(void); /** * Get the union of all the flags for all the tap listeners; that gives * an indication of whether the protocol tree, or the columns, are * required by any taps. */ WS_DLL_PUBLIC guint union_of_tap_listener_flags(void); /** This function can be used by a dissector to fetch any tapped data before * returning. * This can be useful if one wants to extract the data inside dissector BEFORE * it exists as an alternative to the callbacks that are all called AFTER the * dissection has completed. * * Example: SMB2 uses this mechanism to extract the data tapped from NTLMSSP * containing the account and domain names before exiting. * Note that the SMB2 tap listener specifies all three callbacks as NULL. * * Beware: when using this mechanism to extract the tapped data you can not * use "filters" and should specify the "filter" as NULL when registering * the tap listener. */ WS_DLL_PUBLIC const void *fetch_tapped_data(int tap_id, int idx); /** Clean internal structures */ extern void tap_cleanup(void); #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* __TAP_H__ */