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/* reassemble.h
* Declarations of outines for {fragment,segment} reassembly
*
* $Id: reassemble.h,v 1.4 2002/02/03 23:28:38 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* 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.
*/
/* make sure that all flags that are set in a fragment entry is also set for
* the flags field of fd_head !!!
*/
/* only in fd_head: packet is defragmented */
#define FD_DEFRAGMENTED 0x0001
/* there are overlapping fragments */
#define FD_OVERLAP 0x0002
/* overlapping fragments contain different data */
#define FD_OVERLAPCONFLICT 0x0004
/* more than one fragment which indicates end-of data */
#define FD_MULTIPLETAILS 0x0008
/* fragment contains data past the end of the datagram */
#define FD_TOOLONGFRAGMENT 0x0010
/* fragment data not alloced, fd->data pointing to fd_head->data+fd->offset */
#define FD_NOT_MALLOCED 0x0020
/* this flag is used to request fragment_add to continue the reassembly process */
#define FD_PARTIAL_REASSEMBLY 0x0040
/* fragment offset is indicated by sequence number and not byte offset
into the defragmented packet */
#define FD_BLOCKSEQUENCE 0x0100
typedef struct _fragment_data {
struct _fragment_data *next;
guint32 frame;
guint32 offset;
guint32 len;
guint32 datalen; /*Only valid in first item of list */
guint32 flags;
unsigned char *data;
} fragment_data;
/*
* Initialize a fragment table.
*/
void fragment_table_init(GHashTable **fragment_table);
/*
* Free up all space allocated for fragment keys and data.
*/
void reassemble_init(void);
/*
* This function adds a new fragment to the fragment hash table.
* If this is the first fragment seen for this datagram, a new entry
* is created in the hash table, otherwise this fragment is just added
* to the linked list of fragments for this packet.
* The list of fragments for a specific datagram is kept sorted for
* easier handling.
*
* Returns a pointer to the head of the fragment data list if we have all the
* fragments, NULL otherwise.
*/
fragment_data *fragment_add(tvbuff_t *tvb, int offset, packet_info *pinfo,
guint32 id, GHashTable *fragment_table, guint32 frag_offset,
guint32 frag_data_len, gboolean more_frags);
/* same as fragment_add() but this one assumes frag_offset is a block
sequence number. note that frag_offset is 0 for the first fragment. */
fragment_data *fragment_add_seq(tvbuff_t *tvb, int offset, packet_info *pinfo,
guint32 id, GHashTable *fragment_table, guint32 frag_offset,
guint32 frag_data_len, gboolean more_frags);
/* to specify how much to reassemble, for fragmentation where last fragment can not be
* identified by flags or such.
* note that for FD_BLOCKSEQUENCE tot_len is the index for the tail fragment.
* i.e. since the block numbers start at 0, if we specify tot_len==2, that
* actually means we want to defragment 3 blocks, block 0, 1 and 2.
*
*/
void
fragment_set_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
guint32 tot_len);
/*
* This function will set the partial reassembly flag(FD_PARTIAL_REASSEMBLY) for a fh.
* When this function is called, the fh MUST already exist, i.e.
* the fh MUST be created by the initial call to fragment_add() before
* this function is called. Also note that this function MUST be called to indicate
* a fh will be extended (increase the already stored data). After calling this function,
* and if FD_DEFRAGMENTED is set, the reassembly process will be continued.
*/
void
fragment_set_partial_reassembly(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
/* This function is used to check if there is partial or completed reassembly state
* matching this packet. I.e. Are there reassembly going on or not for this packet?
*/
fragment_data *
fragment_get(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
/* This will free up all resources and delete reassembly state for this PDU.
* Except if the PDU is completely reassembled, then it would NOT deallocate the
* buffer holding the reassembled data but instead return the pointer to that
* buffer.
*
* So, if you call fragment_delete and it returns non-NULL, YOU are responsible to
* g_free() that buffer.
*/
unsigned char *
fragment_delete(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
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