/* conversation.h
 * Routines for building lists of packets that are part of a "conversation"
 *
 * $Id$
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifndef __CONVERSATION_H__
#define __CONVERSATION_H__

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/**
 *@file
 */
/*
 * Flags to pass to "conversation_new()" to indicate that the address 2
 * and/or port 2 values for the conversation should be wildcards.
 * The CONVERSATION_TEMPLATE option tells that any of the other supplied
 * port and / or address wildcards will be used to match an infinite number
 * of new connections to the conversation(s) that have the CONVERSATION_-
 * TEMPLATE flag set. Any conversation created without the CONVERSATION_-
 * TEMPLATE flag will be altered once the first connections (connection
 * oriented protocols only) to include the newly found information which
 * matched the wildcard options.
 */
#define NO_ADDR2 0x01
#define NO_PORT2 0x02
#define NO_PORT2_FORCE 0x04
#define CONVERSATION_TEMPLATE 0x08

/*
 * Flags to pass to "find_conversation()" to indicate that the address B
 * and/or port B search arguments are wildcards.
 */
#define NO_ADDR_B 0x01
#define NO_PORT_B 0x02

#include "packet.h"		/* for conversation dissector type */

/**
 * Data structure representing a conversation.
 */
typedef struct conversation_key {
	struct conversation_key *next;
	address	addr1;
	address	addr2;
	port_type ptype;
	guint32	port1;
	guint32	port2;
} conversation_key;

typedef struct conversation {
	struct conversation *next;	/** pointer to next conversation on hash chain */
	struct conversation *last;	/** pointer to the last conversation on hash chain */
	guint32	index;				/** unique ID for conversation */
	guint32 setup_frame;		/** frame number that setup this conversation */
	GSList *data_list;			/** list of data associated with conversation */
	dissector_handle_t dissector_handle;
								/** handle for protocol dissector client associated with conversation */
	guint	options;			/** wildcard flags */
	conversation_key *key_ptr;	/** pointer to the key for this conversation */
} conversation_t;

/**
 * Destroy all existing conversations
 */
extern void conversation_cleanup(void);

/**
 * Initialize some variables every time a file is loaded or re-loaded.
 * Create a new hash table for the conversations in the new file.
 */
extern void conversation_init(void);

/*
 * Given two address/port pairs for a packet, create a new conversation
 * to contain packets between those address/port pairs.
 *
 * The options field is used to specify whether the address 2 value
 * and/or port 2 value are not given and any value is acceptable
 * when searching for this conversation.
 */
extern conversation_t *conversation_new(const guint32 setup_frame, const address *addr1, const address *addr2,
    const port_type ptype, const guint32 port1, const guint32 port2, const guint options);

/**
 * Given two address/port pairs for a packet, search for a conversation
 * containing packets between those address/port pairs.  Returns NULL if
 * not found.
 *
 * We try to find the most exact match that we can, and then proceed to
 * try wildcard matches on the "addr_b" and/or "port_b" argument if a more
 * exact match failed.
 *
 * Either or both of the "addr_b" and "port_b" arguments may be specified as
 * a wildcard by setting the NO_ADDR_B or NO_PORT_B flags in the "options"
 * argument.  We do only wildcard matches on addresses and ports specified
 * as wildcards.
 *
 * I.e.:
 *
 *	if neither "addr_b" nor "port_b" were specified as wildcards, we
 *	do an exact match (addr_a/port_a and addr_b/port_b) and, if that
 *	succeeds, we return a pointer to the matched conversation;
 *
 *	otherwise, if "port_b" wasn't specified as a wildcard, we try to
 *	match any address 2 with the specified port 2 (addr_a/port_a and
 *	{any}/addr_b) and, if that succeeds, we return a pointer to the
 *	matched conversation;
 *
 *	otherwise, if "addr_b" wasn't specified as a wildcard, we try to
 *	match any port 2 with the specified address 2 (addr_a/port_a and
 *	addr_b/{any}) and, if that succeeds, we return a pointer to the
 *	matched conversation;
 *
 *	otherwise, we try to match any address 2 and any port 2
 *	(addr_a/port_a and {any}/{any}) and, if that succeeds, we return
 *	a pointer to the matched conversation;
 *
 *	otherwise, we found no matching conversation, and return NULL.
 */
extern conversation_t *find_conversation(const guint32 frame_num, const address *addr_a, const address *addr_b,
    const port_type ptype, const guint32 port_a, const guint32 port_b, const guint options);

/**  A helper function that calls find_conversation() and, if a conversation is
 *  not found, calls conversation_new().
 *  The frame number and addresses are taken from pinfo.
 *  No options are used, though we could extend this API to include an options
 *  parameter.
 */
extern conversation_t *find_or_create_conversation(packet_info *pinfo);

extern void conversation_add_proto_data(conversation_t *conv, const int proto,
    void *proto_data);
extern void *conversation_get_proto_data(const conversation_t *conv, const int proto);
extern void conversation_delete_proto_data(conversation_t *conv, const int proto);

extern void conversation_set_dissector(conversation_t *conversation,
    const dissector_handle_t handle);
/**
 * Given two address/port pairs for a packet, search for a matching
 * conversation and, if found and it has a conversation dissector,
 * call that dissector and return TRUE, otherwise return FALSE.
 *
 * This helper uses call_dissector_only which will NOT call the default
 * "data" dissector if the packet was rejected.
 * Our caller is responsible to call the data dissector explicitely in case
 * this function returns FALSE.
 */
extern gboolean
try_conversation_dissector(const address *addr_a, const address *addr_b, const port_type ptype,
    const guint32 port_a, const guint32 port_b, tvbuff_t *tvb, packet_info *pinfo,
    proto_tree *tree);

/* These routines are used to set undefined values for a conversation */

extern void conversation_set_port2(conversation_t *conv, const guint32 port);
extern void conversation_set_addr2(conversation_t *conv, const address *addr);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* conversation.h */