nexmon – Rev 1
?pathlinks?
/* reassemble.h
* Declarations of routines for {fragment,segment} reassembly
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* make sure that all flags that are set in a fragment entry is also set for
* the flags field of fd_head !!!
*/
#ifndef REASSEMBLE_H
#define REASSEMBLE_H
#include "ws_symbol_export.h"
/* 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 starts before the end of the datagram but extends
past the end of the datagram */
#define FD_TOOLONGFRAGMENT 0x0010
/* fragment tvb is subset, don't tvb_free() it */
#define FD_SUBSET_TVB 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
/* This flag is set in (only) fd_head to denote that datalen has been set to a valid value.
* It's implied by FD_DEFRAGMENTED (we must know the total length of the
* datagram if we have defragmented it...)
*/
#define FD_DATALEN_SET 0x0400
typedef struct _fragment_item {
struct _fragment_item *next;
guint32 frame; /* XXX - does this apply to reassembly heads? */
guint32 offset; /* XXX - does this apply to reassembly heads? */
guint32 len; /* XXX - does this apply to reassembly heads? */
guint32 fragment_nr_offset; /**< offset for frame numbering, for sequences, where the
* provided fragment number of the first fragment does
* not start with 0
* XXX - does this apply only to reassembly heads? */
guint32 datalen; /**< When flags&FD_BLOCKSEQUENCE is set, the
index of the last block (segments in
datagram + 1); otherwise the number of
bytes of the full datagram. Only valid in
the first item of the fragments list when
flags&FD_DATALEN is set.*/
guint32 reassembled_in; /**< frame where this PDU was reassembled,
only valid in the first item of the list
and when FD_DEFRAGMENTED is set*/
guint8 reas_in_layer_num; /**< The current "depth" or layer number in the current frame where reassembly was completed.
* Example: in SCTP there can be several data chunks and we want the reassemblied tvb for the final
* segment only.
*/
guint32 flags; /**< XXX - do some of these apply only to reassembly
heads and others only to fragments within
a reassembly? */
tvbuff_t *tvb_data;
/**
* Null if the reassembly had no error; non-null if it had
* an error, in which case it's the string for the error.
*
* XXX - this is wasted in all but the reassembly head; we
* should probably have separate data structures for a
* reassembly and for the fragments in a reassembly.
*/
const char *error;
} fragment_item, fragment_head;
/*
* Flags for fragment_add_seq_*
*/
/* we don't have any sequence numbers - fragments are assumed to appear in
* order */
#define REASSEMBLE_FLAGS_NO_FRAG_NUMBER 0x0001
/* a special fudge for the 802.11 dissector */
#define REASSEMBLE_FLAGS_802_11_HACK 0x0002
/*
* Generates a fragment identifier based on the given parameters. "data" is an
* opaque type whose interpretation is up to the caller of fragment_add*
* functions and the fragment key function (possibly NULL if you do not care).
*
* Keys returned by this function are only used within this packet scope.
*/
typedef gpointer (*fragment_temporary_key)(const packet_info *pinfo,
const guint32 id, const void *data);
/*
* Like fragment_temporary_key, but used for identifying reassembled fragments
* which may persist through multiple packets.
*/
typedef gpointer (*fragment_persistent_key)(const packet_info *pinfo,
const guint32 id, const void *data);
/*
* Data structure to keep track of fragments and reassemblies.
*/
typedef struct {
GHashTable *fragment_table;
GHashTable *reassembled_table;
fragment_temporary_key temporary_key_func;
fragment_persistent_key persistent_key_func;
GDestroyNotify free_temporary_key_func; /* temporary key destruction function */
} reassembly_table;
/*
* Table of functions for a reassembly table.
*/
typedef struct {
/* Functions for fragment table */
GHashFunc hash_func; /* hash function */
GEqualFunc equal_func; /* comparison function */
fragment_temporary_key temporary_key_func; /* temporary key creation function */
fragment_persistent_key persistent_key_func; /* persistent key creation function */
GDestroyNotify free_temporary_key_func; /* temporary key destruction function */
GDestroyNotify free_persistent_key_func; /* persistent key destruction function */
} reassembly_table_functions;
/*
* Tables of functions exported for the benefit of dissectors that
* don't need special items in their keys.
*/
WS_DLL_PUBLIC const reassembly_table_functions
addresses_reassembly_table_functions; /* keys have endpoint addresses and an ID */
WS_DLL_PUBLIC const reassembly_table_functions
addresses_ports_reassembly_table_functions; /* keys have endpoint addresses and ports and an ID */
/*
* Initialize/destroy a reassembly table.
*
* init: If table doesn't exist: create table;
* else: just remove any entries;
* destroy: remove entries and destroy table;
*/
WS_DLL_PUBLIC void
reassembly_table_init(reassembly_table *table,
const reassembly_table_functions *funcs);
WS_DLL_PUBLIC void
reassembly_table_destroy(reassembly_table *table);
/*
* This function adds a new fragment to the reassembly table
* If this is the first fragment seen for this datagram, a new entry
* is created in the 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.
*
* Datagrams (messages) are identified by a key generated by
* fragment_temporary_key or fragment_persistent_key, based on the "pinfo", "id"
* and "data" pairs. (This is the sole purpose of "data".)
*
* Fragments are identified by "frag_offset".
*
* Returns a pointer to the head of the fragment data list if we have all the
* fragments, NULL otherwise. Note that the reassembled fragments list may have
* a non-zero fragment offset, the only guarantee is that no gaps exist within
* the list.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add(reassembly_table *table, tvbuff_t *tvb, const int offset,
const packet_info *pinfo, const guint32 id, const void *data,
const guint32 frag_offset, const guint32 frag_data_len,
const gboolean more_frags);
/*
* Like fragment_add, except that the fragment may be added to multiple
* reassembly tables. This is needed when multiple protocol layers try
* to add the same packet to the reassembly table.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_multiple_ok(reassembly_table *table, tvbuff_t *tvb,
const int offset, const packet_info *pinfo,
const guint32 id, const void *data,
const guint32 frag_offset,
const guint32 frag_data_len,
const gboolean more_frags);
/*
* Like fragment_add, but maintains a table for completed reassemblies.
*
* If the packet was seen before, return the head of the fully reassembled
* fragments list (NULL if there was none).
*
* Otherwise (if reassembly was not possible before), try to to add the new
* fragment to the fragments table. If reassembly is now possible, remove all
* (reassembled) fragments from the fragments table and store it as a completed
* reassembly. The head of this reassembled fragments list is returned.
*
* Otherwise (if reassembly is still not possible after adding this fragment),
* return NULL.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_check(reassembly_table *table, tvbuff_t *tvb, const int offset,
const packet_info *pinfo, const guint32 id,
const void *data, const guint32 frag_offset,
const guint32 frag_data_len, const gboolean more_frags);
/*
* Like fragment_add, but fragments have a block sequence number starting from
* zero (for the first fragment of each datagram). This differs from
* fragment_add for which the fragment may start at any offset.
*
* If this is the first fragment seen for this datagram, a new
* "fragment_head" structure is allocated to refer to the reassembled
* packet, and:
*
* if "more_frags" is false, and either we have no sequence numbers, or
* are using the 802.11 hack (via fragment_add_seq_802_11), it is assumed that
* this is the only fragment in the datagram. The structure is not added to the
* hash table, and not given any fragments to refer to, but is just returned.
*
* In this latter case reassembly wasn't done (since there was only one
* fragment in the packet); dissectors can check the 'next' pointer on the
* returned list to see if this case was hit or not.
*
* Otherwise, this fragment is just added to the linked list of fragments
* for this packet; the fragment_item is also added to the fragment hash if
* necessary.
*
* If this packet completes assembly, these functions return the head of the
* fragment data; otherwise, they return null.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_seq(reassembly_table *table, tvbuff_t *tvb, const int offset,
const packet_info *pinfo, const guint32 id, const void *data,
const guint32 frag_number, const guint32 frag_data_len,
const gboolean more_frags, const guint32 flags);
/*
* Like fragment_add_seq, but maintains a table for completed reassemblies
* just like fragment_add_check.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_seq_check(reassembly_table *table, tvbuff_t *tvb, const int offset,
const packet_info *pinfo, const guint32 id,
const void *data,
const guint32 frag_number, const guint32 frag_data_len,
const gboolean more_frags);
/*
* Like fragment_add_seq_check, but immediately returns a fragment list for a
* new fragment. This is a workaround specific for the 802.11 dissector, do not
* use it elsewhere.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_seq_802_11(reassembly_table *table, tvbuff_t *tvb,
const int offset, const packet_info *pinfo,
const guint32 id, const void *data,
const guint32 frag_number, const guint32 frag_data_len,
const gboolean more_frags);
/*
* Like fragment_add_seq_check, but without explicit fragment number. Fragments
* are simply appended until no "more_frags" is false.
*/
WS_DLL_PUBLIC fragment_head *
fragment_add_seq_next(reassembly_table *table, tvbuff_t *tvb, const int offset,
const packet_info *pinfo, const guint32 id,
const void *data, const guint32 frag_data_len,
const gboolean more_frags);
/*
* Start a reassembly, expecting "tot_len" as the number of given fragments (not
* the number of bytes). Data can be added later using fragment_add_seq_check.
*/
WS_DLL_PUBLIC void
fragment_start_seq_check(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data,
const guint32 tot_len);
/*
* Mark end of reassembly and returns the reassembled fragment (if completed).
* Use it when fragments were added with "more_flags" set while you discovered
* that no more fragments have to be added.
* XXX rename to fragment_finish as it works also for fragment_add?
*/
WS_DLL_PUBLIC fragment_head *
fragment_end_seq_next(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data);
/* To specify the offset for the fragment numbering, the first fragment is added with 0, and
* afterwards this offset is set. All additional calls to off_seq_check will calculate
* the number in sequence in regards to the offset */
WS_DLL_PUBLIC void
fragment_add_seq_offset(reassembly_table *table, const packet_info *pinfo, const guint32 id,
const void *data, const guint32 fragment_offset);
/*
* Sets the expected index for the last block (for fragment_add_seq functions)
* or the expected number of bytes (for fragment_add functions). A reassembly
* must already have started.
*
* 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.
*/
WS_DLL_PUBLIC void
fragment_set_tot_len(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data, const guint32 tot_len);
/*
* Return the expected index for the last block (for fragment_add_seq functions)
* or the expected number of bytes (for fragment_add functions).
*/
WS_DLL_PUBLIC guint32
fragment_get_tot_len(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data);
/*
* 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.
*/
WS_DLL_PUBLIC void
fragment_set_partial_reassembly(reassembly_table *table,
const packet_info *pinfo, const guint32 id,
const void *data);
/* 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?
*/
WS_DLL_PUBLIC fragment_head *
fragment_get(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data);
/* The same for the reassemble table */
/* id *must* be the frame number for this to work! */
WS_DLL_PUBLIC fragment_head *
fragment_get_reassembled(reassembly_table *table, const guint32 id);
WS_DLL_PUBLIC fragment_head *
fragment_get_reassembled_id(reassembly_table *table, const packet_info *pinfo,
const guint32 id);
/* 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 TVB
*
* So, if you call fragment_delete and it returns non-NULL, YOU are responsible to
* tvb_free() .
*/
WS_DLL_PUBLIC tvbuff_t *
fragment_delete(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data);
/* This struct holds references to all the tree and field handles used when
* displaying the reassembled fragment tree in the packet details view. A
* dissector will populate this structure with its own tree and field handles
* and then invoke show_fragement_tree to have those items added to the packet
* details tree.
*/
typedef struct _fragment_items {
gint *ett_fragment;
gint *ett_fragments;
int *hf_fragments; /* FT_NONE */
int *hf_fragment; /* FT_FRAMENUM */
int *hf_fragment_overlap; /* FT_BOOLEAN */
int *hf_fragment_overlap_conflict; /* FT_BOOLEAN */
int *hf_fragment_multiple_tails; /* FT_BOOLEAN */
int *hf_fragment_too_long_fragment; /* FT_BOOLEAN */
int *hf_fragment_error; /* FT_FRAMENUM */
int *hf_fragment_count; /* FT_UINT32 */
int *hf_reassembled_in; /* FT_FRAMENUM */
int *hf_reassembled_length; /* FT_UINT32 */
int *hf_reassembled_data; /* FT_BYTES */
const char *tag;
} fragment_items;
WS_DLL_PUBLIC tvbuff_t *
process_reassembled_data(tvbuff_t *tvb, const int offset, packet_info *pinfo,
const char *name, fragment_head *fd_head, const fragment_items *fit,
gboolean *update_col_infop, proto_tree *tree);
WS_DLL_PUBLIC gboolean
show_fragment_tree(fragment_head *ipfd_head, const fragment_items *fit,
proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, proto_item **fi);
WS_DLL_PUBLIC gboolean
show_fragment_seq_tree(fragment_head *ipfd_head, const fragment_items *fit,
proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, proto_item **fi);
#endif