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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:34:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:34:10 +0000
commite4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch)
tree68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/reassemble.h
parentInitial commit. (diff)
downloadwireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz
wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/reassemble.h')
-rw-r--r--epan/reassemble.h1166
1 files changed, 1166 insertions, 0 deletions
diff --git a/epan/reassemble.h b/epan/reassemble.h
new file mode 100644
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--- /dev/null
+++ b/epan/reassemble.h
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+/** @file
+ * Declarations of routines for {fragment,segment} reassembly
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/* 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; /**< frame number where the fragment is from */
+ guint32 offset; /**< fragment number for FD_BLOCKSEQUENCE, byte
+ * offset otherwise */
+ guint32 len; /**< fragment length */
+ guint32 flags; /**< XXX - do some of these apply only to reassembly
+ * heads and others only to fragments within
+ * a reassembly? */
+ tvbuff_t *tvb_data;
+} fragment_item;
+
+typedef struct _fragment_head {
+ struct _fragment_item *next;
+ struct _fragment_item *first_gap; /**< pointer to last fragment before first gap.
+ * NULL if there is no fragment starting at offset 0 */
+ guint ref_count; /**< reference count in reassembled_table */
+ guint32 contiguous_len; /**< contigous length from head up to first gap */
+ guint32 frame; /**< maximum of all frame numbers added to reassembly */
+ guint32 len; /**< When flags&FD_BLOCKSEQUENCE and FD_DEFRAGMENTED
+ * are set, the number of bytes of the full datagram.
+ * Otherwise not valid. */
+ guint32 fragment_nr_offset; /**< offset for frame numbering, for sequences, where the
+ * provided fragment number of the first fragment does
+ * not start with 0 */
+ 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 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.
+ */
+ const char *error;
+} 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
+
+/*
+ * Flags for fragment_add_seq_single_*
+ */
+
+/* we want to age off old packets */
+#define REASSEMBLE_FLAGS_AGING 0x0001
+
+/*
+ * 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 */
+
+/*
+ * Register a reassembly table. By registering the table with epan, the creation and
+ * destruction of the table can be managed by epan and not the dissector.
+ */
+WS_DLL_PUBLIC void
+reassembly_table_register(reassembly_table *table,
+ const reassembly_table_functions *funcs);
+
+/*
+ * 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.
+ *
+ * @note Reused keys are assumed to refer to the same reassembled message
+ * (i.e., retransmission). If the same "id" is used more than once on a
+ * connection, then "data" and custom reassembly_table_functions should be
+ * used so that the keys hash differently.
+ */
+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, except that the fragment may originate from a frame
+ * other than pinfo->num. For use when you are adding an out of order segment
+ * that arrived in an earlier frame, so that show_fragment_tree will display
+ * the correct fragment numbers.
+ *
+ * This is for protocols like TCP, where the correct reassembly to add a
+ * segment to cannot be determined without processing previous segments
+ * in sequence order, including handing them to subdissectors.
+ *
+ * Note that pinfo is still used to set reassembled_in if we have all the
+ * fragments, so that results on subsequent passes can be the same as the
+ * first pass.
+ */
+WS_DLL_PUBLIC fragment_head *
+fragment_add_out_of_order(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, const guint32 frag_frame);
+/*
+ * 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 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.
+ *
+ * @note Completed reassemblies are removed from the in-progress table, so
+ * key can be reused to begin a new reassembled message. Conversely,
+ * dissectors SHOULD NOT call this with a retransmitted fragment of a
+ * completed reassembly. Dissectors atop a reliable protocol like TCP
+ * may assume that the lower layer dissector handles retransmission,
+ * but other dissectors (e.g., atop UDP or Ethernet) will have to handle
+ * that situation themselves.
+ */
+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_check, but handles retransmissions after reassembly.
+ *
+ * Start new reassembly only if there is no reassembly in progress and there
+ * is no completed reassembly reachable from fallback_frame. If there is
+ * completed reassembly (reachable from fallback_frame), simply links this
+ * packet into the list, updating the flags if necessary (however actual data
+ * and reassembled in frame won't be modified).
+ */
+WS_DLL_PUBLIC fragment_head *
+fragment_add_check_with_fallback(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,
+ const guint32 fallback_frame);
+
+/*
+ * 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.
+ *
+ * @note Reused keys are assumed to refer to the same reassembled message
+ * (i.e., retransmission). If the same "id" is used more than once on a
+ * connection, then "data" and custom reassembly_table_functions should be
+ * used so that the keys hash differently.
+ */
+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.
+ *
+ * @note Completed reassemblies are removed from the in-progress table, so
+ * key can be reused to begin a new reassembled message. Conversely,
+ * dissectors SHOULD NOT call this with a retransmitted fragment of a
+ * completed reassembly. Dissectors atop a reliable protocol like TCP
+ * may assume that the lower layer dissector handles retransmission,
+ * but other dissectors (e.g., atop UDP or Ethernet) will have to handle
+ * that situation themselves.
+ */
+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.
+ *
+ * @note Out of order fragments will not be reassembled correctly.
+ * Dissectors atop a reliable protocol like TCP may rely on the lower
+ * level dissector reordering out or order segments (if the appropraite
+ * out of order reassembly preference is enabled), but other dissectors
+ * will have to handle out of order fragments themselves, if possible.
+ */
+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);
+
+/*
+ * Like fragment_add_seq_check, but for protocols like PPP MP with a single
+ * sequence number that increments for each fragment, thus acting like the sum
+ * of the PDU sequence number and explicit fragment number in other protocols.
+ * See Appendix A of RFC 4623 (PWE3 Fragmentation and Reassembly) for a list
+ * of protocols that use this style, including PPP MP (RFC 1990), PWE3 MPLS
+ * (RFC 4385), L2TPv2 (RFC 2661), L2TPv3 (RFC 3931), ATM, and Frame Relay.
+ * It is guaranteed to reassemble a packet split up to "max_frags" in size,
+ * but may manage to reassemble more in certain cases.
+ */
+WS_DLL_PUBLIC fragment_head *
+fragment_add_seq_single(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 first, const gboolean last,
+ const guint32 max_frags);
+
+/*
+ * A variation on the above that ages off fragments that have not been
+ * reassembled. Useful if the sequence number loops to deal with leftover
+ * fragments from the beginning of the capture or missing fragments.
+ */
+WS_DLL_PUBLIC fragment_head *
+fragment_add_seq_single_aging(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 first, const gboolean last,
+ const guint32 max_frags, const guint32 max_age);
+
+/*
+ * 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.
+ * This is for fragments added with add_seq_next; it doesn't check for gaps,
+ * and doesn't set datalen correctly for the fragment_add family.
+ */
+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);
+
+/*
+ * Similar to fragment_set_tot_len, it sets the expected number of bytes (for
+ * fragment_add functions) for a previously started reassembly. If the specified
+ * length already matches the reassembled length, then nothing will be done.
+ *
+ * If the fragments were previously reassembled, then this state will be
+ * cleared, allowing new fragments to extend the reassembled result again.
+ */
+void
+fragment_reset_tot_len(reassembly_table *table, const packet_info *pinfo,
+ const guint32 id, const void *data, const guint32 tot_len);
+
+/*
+ * Truncates the size of an already defragmented reassembly to tot_len,
+ * discarding past that point, including splitting any fragments in the
+ * middle as necessary. The specified length must be less than or equal
+ * to the reassembled length. (If it already matches the reassembled length,
+ * then nothing will be done.)
+ *
+ * Used for continuous streams like TCP, where the length of a segment cannot
+ * be determined without first reassembling and handing to a subdissector.
+ */
+void
+fragment_truncate(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 */
+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_fragment_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);
+
+/* Initialize internal structures
+ */
+extern void reassembly_tables_init(void);
+
+/* Cleanup internal structures
+ */
+extern void
+reassembly_table_cleanup(void);
+
+/* ===================== Streaming data reassembly helper ===================== */
+/**
+ * Macro to help to define ett or hf items variables for reassembly (especially for streaming reassembly).
+ * The statement:
+ *
+ * REASSEMBLE_ITEMS_DEFINE(foo_body, "Foo Body"); // in global scope
+ *
+ * will create global variables:
+ *
+ * static gint ett_foo_body_fragment = -1;
+ * static gint ett_foo_body_fragments = -1;
+ * static int hf_foo_body_fragment = -1;
+ * static int hf_foo_body_fragments = -1;
+ * static int hf_foo_body_fragment_overlap = -1;
+ * ...
+ * static int hf_foo_body_segment = -1;
+ *
+ * static const fragment_items foo_body_fragment_items = {
+ * &ett_foo_body_fragment,
+ * &ett_foo_body_fragments,
+ * &hf_foo_body_fragments,
+ * &hf_foo_body_fragment,
+ * &hf_foo_body_fragment_overlap,
+ * ...
+ * "Foo Body fragments"
+ * };
+ */
+#define REASSEMBLE_ITEMS_DEFINE(var_prefix, name_prefix) \
+ static gint ett_##var_prefix##_fragment = -1; \
+ static gint ett_##var_prefix##_fragments = -1; \
+ static int hf_##var_prefix##_fragments = -1; \
+ static int hf_##var_prefix##_fragment = -1; \
+ static int hf_##var_prefix##_fragment_overlap = -1; \
+ static int hf_##var_prefix##_fragment_overlap_conflicts = -1; \
+ static int hf_##var_prefix##_fragment_multiple_tails = -1; \
+ static int hf_##var_prefix##_fragment_too_long_fragment = -1; \
+ static int hf_##var_prefix##_fragment_error = -1; \
+ static int hf_##var_prefix##_fragment_count = -1; \
+ static int hf_##var_prefix##_reassembled_in = -1; \
+ static int hf_##var_prefix##_reassembled_length = -1; \
+ static int hf_##var_prefix##_reassembled_data = -1; \
+ static int hf_##var_prefix##_segment = -1; \
+ static const fragment_items var_prefix##_fragment_items = { \
+ &ett_##var_prefix##_fragment, \
+ &ett_##var_prefix##_fragments, \
+ &hf_##var_prefix##_fragments, \
+ &hf_##var_prefix##_fragment, \
+ &hf_##var_prefix##_fragment_overlap, \
+ &hf_##var_prefix##_fragment_overlap_conflicts, \
+ &hf_##var_prefix##_fragment_multiple_tails, \
+ &hf_##var_prefix##_fragment_too_long_fragment, \
+ &hf_##var_prefix##_fragment_error, \
+ &hf_##var_prefix##_fragment_count, \
+ &hf_##var_prefix##_reassembled_in, \
+ &hf_##var_prefix##_reassembled_length, \
+ &hf_##var_prefix##_reassembled_data, \
+ name_prefix " fragments" \
+ }
+
+/**
+ * Macro to help to initialize hf (head field) items for reassembly.
+ * The statement:
+ *
+ * void proto_register_foo(void) {
+ * static hf_register_info hf[] = {
+ * ...
+ * { &hf_proto_foo_payload,
+ * { "Payload", "foo.payload",
+ * FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
+ * },
+ *
+ * // Add fragments items
+ * REASSEMBLE_INIT_HF_ITEMS(foo_body, "Foo Body", "foo.body"),
+ * ...
+ * };
+ * ...
+ * }
+ *
+ * will expand like:
+ *
+ * void proto_register_foo(void) {
+ * static hf_register_info hf[] = {
+ * ...
+ * { &hf_proto_foo_payload,
+ * { "Payload", "foo.payload",
+ * FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
+ * },
+ *
+ * // Add fragments items
+ * { &hf_foo_body_fragments, \
+ * { "Reassembled Foo Body fragments", "foo.body.fragments", \
+ * FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ * },
+ * { &hf_foo_body_fragment, \
+ * { "Foo Body fragment", "foo.body.fragment", \
+ * FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ * },
+ * { &hf_foo_body_fragment_overlap, \
+ * { "Foo Body fragment overlap", "foo.body.fragment.overlap", \
+ * FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ * },
+ * ...
+ * };
+ * ...
+ * }
+ */
+#define REASSEMBLE_INIT_HF_ITEMS(var_prefix, name_prefix, abbrev_prefix) \
+ { &hf_##var_prefix##_fragments, \
+ { "Reassembled " name_prefix " fragments", abbrev_prefix ".fragments", \
+ FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment, \
+ { name_prefix " fragment", abbrev_prefix ".fragment", \
+ FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_overlap, \
+ { name_prefix " fragment overlap", abbrev_prefix ".fragment.overlap", \
+ FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_overlap_conflicts, \
+ { name_prefix " fragment overlapping with conflicting data", abbrev_prefix ".fragment.overlap.conflicts", \
+ FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_multiple_tails, \
+ { name_prefix " has multiple tail fragments", abbrev_prefix ".fragment.multiple_tails", \
+ FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_too_long_fragment, \
+ { name_prefix " fragment too long", abbrev_prefix ".fragment.too_long_fragment", \
+ FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_error, \
+ { name_prefix " defragment error", abbrev_prefix ".fragment.error", \
+ FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_fragment_count, \
+ { name_prefix " fragment count", abbrev_prefix ".fragment.count", \
+ FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_reassembled_in, \
+ { "Reassembled in", abbrev_prefix ".reassembled.in", \
+ FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_reassembled_length, \
+ { "Reassembled length", abbrev_prefix ".reassembled.length", \
+ FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_reassembled_data, \
+ { "Reassembled data", abbrev_prefix ".reassembled.data", \
+ FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL } \
+ }, \
+ { &hf_##var_prefix##_segment, \
+ { name_prefix " segment", abbrev_prefix ".segment", \
+ FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL} \
+ }
+
+/**
+ * Macro to help to initialize protocol subtree (ett) items for reassembly.
+ * The statement:
+ *
+ * void proto_register_foo(void) {
+ * ...
+ * static gint* ett[] = {
+ * &ett_foo_abc,
+ * ...
+ * // Add ett items
+ * REASSEMBLE_INIT_ETT_ITEMS(foo_body),
+ * ...
+ * };
+ * ...
+ * }
+ *
+ * will expand like:
+ *
+ * void proto_register_foo(void) {
+ * ...
+ * static gint* ett[] = {
+ * &ett_foo_abc,
+ * ...
+ * // Add ett items
+ * &ett_foo_body_fragment,
+ * &ett_foo_body_fragments,
+ * ...
+ * };
+ * ...
+ * }
+ */
+#define REASSEMBLE_INIT_ETT_ITEMS(var_prefix) \
+ &ett_##var_prefix##_fragment, \
+ &ett_##var_prefix##_fragments
+
+/** a private structure for keeping streaming reassembly information */
+typedef struct streaming_reassembly_info_t streaming_reassembly_info_t;
+
+/**
+ * Allocate a streaming reassembly information in wmem_file_scope.
+ */
+WS_DLL_PUBLIC streaming_reassembly_info_t*
+streaming_reassembly_info_new(void);
+
+/**
+ * This function provides a simple way to reassemble the streaming data of a higher level
+ * protocol that is not on top of TCP but on another protocol which might be on top of TCP.
+ *
+ * For example, suppose there are two streaming protocols ProtoA and ProtoB. ProtoA is a protocol on top
+ * of TCP. ProtoB is a protocol on top of ProtoA.
+ *
+ * ProtoA dissector should use tcp_dissect_pdus() or pinfo->can_desegment/desegment_offset/desegment_len
+ * to reassemble its own messages on top of TCP. After the PDUs of ProtoA are reassembled, ProtoA dissector
+ * can call reassemble_streaming_data_and_call_subdissector() to help ProtoB dissector to reassemble the
+ * PDUs of ProtoB. ProtoB needs to use fields pinfo->can_desegment/desegment_offset/desegment_len to tell
+ * its requirements about reassembly (to reassemble_streaming_data_and_call_subdissector()).
+ *
+ * ----- +-- Reassembled ProtoB PDU --+-- Reassembled ProtoB PDU --+-- Reassembled ProtoB PDU --+----------------
+ * ProtoB: | ProtoB header and payload | ProtoB header and payload | ProtoB header and payload | ...
+ * +----------------------------+---------+------------------+--------+-------------------+--+-------------
+ * ----- ^ >>> Reassemble with reassemble_streaming_data_and_call_subdissector() and pinfo->desegment_len.. <<< ^
+ * +----------------------------+---------+------------------+--------+-------------------+--+-------------
+ * | ProtoA payload1 | ProtoA payload2 | ProtoA payload3 | ...
+ * +--------------------------------------+---------------------------+----------------------+-------------
+ * ^ ^ ^ ^
+ * | >>> Do de-chunk <<< |\ >>> Do de-chunk <<< \ \ >>> Do de-chunk <<< \
+ * | | \ \ \ \
+ * | | \ \ \ ...
+ * | | \ \ \ \
+ * +-------- First Reassembled ProtoA PDU ---------+-- Second Reassembled ProtoA PDU ---+- Third Reassembled Prot...
+ * ProtoA: | Header | ProtoA payload1 | Header | ProtoA payload2 | Header | ProtoA payload3 .
+ * +--------+----------------------+---------------+--------+---------------------------+--------+-+----------------
+ * ----- ^ >>> Reassemble with tcp_dissect_pdus() or pinfo->can_desegment/desegment_offset/desegment_len <<< ^
+ * +--------+----------------------+---------------+--------+---------------------------+--------+-+----------------
+ * TCP: | TCP segment | TCP segment | TCP segment | ...
+ * ----- +-------------------------------+-------------------------------+-------------------------------+----------------
+ *
+ * The function reassemble_streaming_data_and_call_subdissector() uses fragment_add() and process_reassembled_data()
+ * to complete its reassembly task.
+ *
+ * The reassemble_streaming_data_and_call_subdissector() will handle many cases. The most complicated one is:
+ *
+ * +-------------------------------------- Payload of a ProtoA PDU -----------------------------------------------+
+ * | EoMSP: end of a multisegment PDU | OmNFP: one or more non-fragment PDUs | BoMSP: begin of a multisegment PDU |
+ * +----------------------------------+--------------------------------------+------------------------------------+
+ * Note, we use short name 'MSP' for 'Multisegment PDU', and 'NFP' for 'Non-fragment PDU'.
+ *
+ * In this case, the payload of a ProtoA PDU contains:
+ * - EoMSP (Part1): At the begin of the ProtoA payload, there is the last part of a multisegment PDU of ProtoB.
+ * - OmNFP (Part2): The middle part of ProtoA payload payload contains one or more non-fragment PDUs of ProtoB.
+ * - BoMSP (Part3): At the tail of the ProtoA payload, there is the begin of a new multisegment PDU of ProtoB.
+ *
+ * All of three parts are optional. For example, one ProtoA payload could contain only EoMSP, OmNFP or BoMSP; or contain
+ * EoMSP and OmNFP without BoMSP; or contain EoMSP and BoMSP without OmNFP; or contain OmNFP and BoMSP without
+ * EoMSP.
+ *
+ * +---- A ProtoB MSP ---+ +-- A ProtoB MSP --+-- A ProtoB MSP --+ +-- A ProtoB MSP --+
+ * | | | | | | |
+ * +- A ProtoA payload -+ +-------+-------+-------+ +-------+-------+ +-------+-------+ +-------+ +-------+ +-------+
+ * | OmNFP | BoMSP | | EoMSP | OmNFP | BoMSP | | EoMSP | BoMSP | | EoMSP | OmNFP | | BoMSP | | EoMSP | | OmNFP |
+ * +---------+----------+ +-------+-------+-------+ +-------+-------+ +-------+-------+ +-------+ +-------+ +-------+
+ * | | | | | | |
+ * +---------------------+ +------------------+------------------+ +------------------+
+ *
+ * And another case is the entire ProtoA payload is one of middle parts of a multisegment PDU. We call it:
+ * - MoMSP: The middle part of a multisegment PDU of ProtoB.
+ *
+ * Following case shows a multisegment PDU composed of [BoMSP + MoMSP + MoMSP + MoMSP + EoMSP]:
+ *
+ * +------------------ A Multisegment PDU of ProtoB ----------------------+
+ * | |
+ * +--- ProtoA payload1 ---+ +- payload2 -+ +- Payload3 -+ +- Payload4 -+ +- ProtoA payload5 -+
+ * | EoMSP | OmNFP | BoMSP | | MoMSP | | MoMSP | | MoMSP | | EoMSP | BoMSP |
+ * +-------+-------+-------+ +------------+ +------------+ +------------+ +---------+---------+
+ * | |
+ * +----------------------------------------------------------------------+
+ *
+ * The function reassemble_streaming_data_and_call_subdissector() will handle all of the above cases and manage
+ * the information used during the reassembly. The caller (ProtoA dissector) only needs to initialize the relevant
+ * variables and pass these variables and its own completed payload to this function.
+ *
+ * The subdissector (ProtoB dissector) needs to set the pinfo->desegment_len to cooperate with the function
+ * reassemble_streaming_data_and_call_subdissector() to complete the reassembly task.
+ * The pinfo->desegment_len should be DESEGMENT_ONE_MORE_SEGMENT or contain the estimated number of additional bytes required for completing
+ * the current PDU (MSP), and set pinfo->desegment_offset to the offset in the tvbuff at which the dissector will
+ * continue processing when next called. Next time the subdissector is called, it will be passed a tvbuff composed
+ * of the end of the data from the previous tvbuff together with desegment_len more bytes. If the dissector cannot
+ * tell how many more bytes it will need, it should set pinfo->desegment_len to DESEGMENT_ONE_MORE_SEGMENT or additional bytes required for parsing
+ * message head. It will then be called again as soon as more data becomes available. Subdissector MUST NOT set the
+ * pinfo->desegment_len to DESEGMENT_UNTIL_FIN, we don't support it yet.
+ *
+ * Note that if the subdissector sets pinfo->desegment_len to additional bytes required for parsing the header of
+ * the message rather than the entire message when the length of entire message is unable to be determined, it MUST
+ * return the length of the tvb handled by itself (for example, return 0 length if nothing is parsed in MoMSP),
+ * otherwise it may cause some unexpected dissecting errors. However, if you want to be compatible with TCP's reassembly
+ * method by setting the pinfo->desegment_len, you MUST set the pinfo->desegment_len to DESEGMENT_ONE_MORE_SEGMENT
+ * when the entire message length cannot be determined, and return a length other than 0 (such as tvb_captured_length(tvb))
+ * when exiting the subdissector dissect function (such as dissect_proto_b()).
+ *
+ * Following is sample code of ProtoB which on top of ProtoA mentioned above:
+ * <code>
+ * // file packet-proto-b.c
+ * ...
+ *
+ * static int
+ * dissect_proto_b(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data)
+ * {
+ * while (offset < tvb_len)
+ * {
+ * if (tvb_len - offset < PROTO_B_MESSAGE_HEAD_LEN) {
+ * // need at least X bytes for getting a ProtoB message
+ * if (pinfo->can_desegment) {
+ * pinfo->desegment_offset = offset;
+ * // It is strongly recommended to set pinfo->desegment_len to DESEGMENT_ONE_MORE_SEGMENT
+ * // if the length of entire message is unknown.
+ * pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
+ * return tvb_len; // MUST return a length other than 0
+ *
+ * // Or set pinfo->desegment_len to how many additional bytes needed to parse head of
+ * // a ProtoB message.
+ * // pinfo->desegment_len = PROTO_B_MESSAGE_HEAD_LEN - (tvb_len - offset);
+ * // return offset; // But you MUST return the length handled by ProtoB
+ * }
+ * ...
+ * }
+ * ...
+ * // e.g. length is at offset 4
+ * body_len = (guint)tvb_get_ntohl(tvb, offset + 4);
+ *
+ * if (tvb_len - offset - PROTO_B_MESSAGE_HEAD_LEN < body_len) {
+ * // need X bytes for dissecting a ProtoB message
+ * if (pinfo->can_desegment) {
+ * pinfo->desegment_offset = offset;
+ * // caculate how many additional bytes need to parsing body of a ProtoB message
+ * pinfo->desegment_len = body_len - (tvb_len - offset - PROTO_B_MESSAGE_HEAD_LEN);
+ * // MUST return a length other than 0, if DESEGMENT_ONE_MORE_SEGMENT is used previously.
+ * return tvb_len;
+ *
+ * // MUST return the length handled by ProtoB,
+ * // if 'pinfo->desegment_len = PROTO_B_MESSAGE_HEAD_LEN - (tvb_len - offset);' is used previously.
+ * // return offset;
+ * }
+ * ...
+ * }
+ * ...
+ * }
+ * return tvb_len; // all bytes of this tvb are parsed
+ * }
+ * </code>
+ *
+ * Following is sample code of ProtoA mentioned above:
+ * <code>
+ * // file packet-proto-a.c
+ * ...
+ * // reassembly table for streaming chunk mode
+ * static reassembly_table proto_a_streaming_reassembly_table;
+ * ...
+ * // heads for displaying reassembley information
+ * static int hf_msg_fragments = -1;
+ * static int hf_msg_fragment = -1;
+ * static int hf_msg_fragment_overlap = -1;
+ * static int hf_msg_fragment_overlap_conflicts = -1;
+ * static int hf_msg_fragment_multiple_tails = -1;
+ * static int hf_msg_fragment_too_long_fragment = -1;
+ * static int hf_msg_fragment_error = -1;
+ * static int hf_msg_fragment_count = -1;
+ * static int hf_msg_reassembled_in = -1;
+ * static int hf_msg_reassembled_length = -1;
+ * static int hf_msg_body_segment = -1;
+ * ...
+ * static gint ett_msg_fragment = -1;
+ * static gint ett_msg_fragments = -1;
+ * ...
+ * static const fragment_items msg_frag_items = {
+ * &ett_msg_fragment,
+ * &ett_msg_fragments,
+ * &hf_msg_fragments,
+ * &hf_msg_fragment,
+ * &hf_msg_fragment_overlap,
+ * &hf_msg_fragment_overlap_conflicts,
+ * &hf_msg_fragment_multiple_tails,
+ * &hf_msg_fragment_too_long_fragment,
+ * &hf_msg_fragment_error,
+ * &hf_msg_fragment_count,
+ * &hf_msg_reassembled_in,
+ * &hf_msg_reassembled_length,
+ * "ProtoA Message fragments"
+ * };
+ * ...
+ * static int
+ * dissect_proto_a(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data)
+ * {
+ * ...
+ * streaming_reassembly_info_t* streaming_reassembly_info = NULL;
+ * ...
+ * proto_a_tree = proto_item_add_subtree(ti, ett_proto_a);
+ * ...
+ * if (!PINFO_FD_VISITED(pinfo)) {
+ * streaming_reassembly_info = streaming_reassembly_info_new();
+ * // save streaming reassembly info in the stream conversation or something like that
+ * save_reassembly_info(pinfo, stream_id, flow_dir, streaming_reassembly_info);
+ * } else {
+ * streaming_reassembly_info = get_reassembly_info(pinfo, stream_id, flow_dir);
+ * }
+ * ...
+ * while (offset < tvb_len)
+ * {
+ * ...
+ * payload_len = xxx;
+ * ...
+ * if (dissecting_in_streaming_mode) {
+ * // reassemble and call subdissector
+ * reassemble_streaming_data_and_call_subdissector(tvb, pinfo, offset,
+ * payload_len, proto_a_tree, proto_tree_get_parent_tree(proto_a_tree),
+ * proto_a_streaming_reassembly_table, streaming_reassembly_info,
+ * get_virtual_frame_num64(tvb, pinfo, offset), subdissector_handle,
+ * proto_tree_get_parent_tree(tree), NULL,
+ * "ProtoA", &msg_frag_items, hf_msg_body_segment);
+ * ...
+ * }
+ * }
+ *
+ * ...
+ * void proto_register_proto_a(void) {
+ * ...
+ * static hf_register_info hf[] = {
+ * ...
+ * {&hf_msg_fragments,
+ * {"Reassembled ProtoA Message fragments", "protoa.msg.fragments",
+ * FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment,
+ * {"Message fragment", "protoa.msg.fragment",
+ * FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_overlap,
+ * {"Message fragment overlap", "protoa.msg.fragment.overlap",
+ * FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_overlap_conflicts,
+ * {"Message fragment overlapping with conflicting data",
+ * "protoa.msg.fragment.overlap.conflicts",
+ * FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_multiple_tails,
+ * {"Message has multiple tail fragments",
+ * "protoa.msg.fragment.multiple_tails",
+ * FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_too_long_fragment,
+ * {"Message fragment too long", "protoa.msg.fragment.too_long_fragment",
+ * FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_error,
+ * {"Message defragmentation error", "protoa.msg.fragment.error",
+ * FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_fragment_count,
+ * {"Message fragment count", "protoa.msg.fragment.count",
+ * FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_reassembled_in,
+ * {"Reassembled in", "protoa.msg.reassembled.in",
+ * FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_reassembled_length,
+ * {"Reassembled length", "protoa.msg.reassembled.length",
+ * FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL } },
+ * {&hf_msg_body_segment,
+ * {"ProtoA body segment", "protoa.msg.body.segment",
+ * FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL } },
+ * }
+ * ...
+ * static gint *ett[] = {
+ * ...
+ * &ett_msg_fragment,
+ * &ett_msg_fragments
+ * }
+ * ...
+ * reassembly_table_register(&proto_a_streaming_reassembly_table,
+ * &addresses_ports_reassembly_table_functions);
+ * ...
+ * }
+ * </code>
+ *
+ * Alternatively, the code of ProtoA (packet-proto-a.c) can be made simpler with helper macros:
+ * <code>
+ * // file packet-proto-a.c
+ * ...
+ * // reassembly table for streaming chunk mode
+ * static reassembly_table proto_a_streaming_reassembly_table;
+ * // reassembly head field items definition
+ * REASSEMBLE_ITEMS_DEFINE(proto_a_body, "ProtoA Body");
+ * ...
+ * static int
+ * dissect_proto_a(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data)
+ * {
+ * ...
+ * streaming_reassembly_info_t* streaming_reassembly_info = NULL;
+ * ...
+ * proto_a_tree = proto_item_add_subtree(ti, ett_proto_a);
+ * ...
+ * if (!PINFO_FD_VISITED(pinfo)) {
+ * streaming_reassembly_info = streaming_reassembly_info_new();
+ * // save streaming reassembly info in the stream conversation or something like that
+ * save_reassembly_info(pinfo, stream_id, flow_dir, streaming_reassembly_info);
+ * } else {
+ * streaming_reassembly_info = get_reassembly_info(pinfo, stream_id, flow_dir);
+ * }
+ * ...
+ * while (offset < tvb_len)
+ * {
+ * ...
+ * payload_len = xxx;
+ * ...
+ * if (dissecting_in_streaming_mode) {
+ * // reassemble and call subdissector
+ * reassemble_streaming_data_and_call_subdissector(tvb, pinfo, offset,
+ * payload_len, proto_a_tree, proto_tree_get_parent_tree(proto_a_tree),
+ * proto_a_streaming_reassembly_table, streaming_reassembly_info,
+ * get_virtual_frame_num64(tvb, pinfo, offset), subdissector_handle,
+ * proto_tree_get_parent_tree(tree), NULL, "ProtoA Body",
+ * &proto_a_body_fragment_items, hf_proto_a_body_segment);
+ * ...
+ * }
+ * }
+ *
+ * ...
+ * void proto_register_proto_a(void) {
+ * ...
+ * static hf_register_info hf[] = {
+ * ...
+ * REASSEMBLE_INIT_HF_ITEMS(proto_a_body, "ProtoA Body", "protoa.body")
+ * }
+ * ...
+ * static gint *ett[] = {
+ * ...
+ * REASSEMBLE_INIT_ETT_ITEMS(proto_a_body)
+ * }
+ * ...
+ * reassembly_table_register(&proto_a_streaming_reassembly_table,
+ * &addresses_ports_reassembly_table_functions);
+ * ...
+ * }
+ * </code>
+ *
+ * @param tvb TVB contains (ProtoA) payload which will be passed to subdissector.
+ * @param pinfo Packet information.
+ * @param offset The beginning offset of payload in TVB.
+ * @param length The length of payload in TVB.
+ * @param segment_tree The tree for adding segment items.
+ * @param reassembled_tree The tree for adding reassembled information items.
+ * @param streaming_reassembly_table The reassembly table used for this kind of streaming reassembly.
+ * @param reassembly_info The structure for keeping streaming reassembly information. This should be initialized
+ * by streaming_reassembly_info_new(). Subdissector should keep it for each flow of per stream,
+ * like per direction flow of a STREAM of HTTP/2 or each request or response message flow of
+ * HTTP/1.1 chunked stream.
+ * @param cur_frame_num The uniq index of current payload and number must always be increasing from the previous frame
+ * number, so we can use "<" and ">" comparisons to determine before and after in time. You can use
+ * get_virtual_frame_num64() if the ProtoA does not has a suitable field representing payload frame num.
+ * @param subdissector_handle The subdissector the reassembly for. We will call subdissector for reassembly and dissecting.
+ * The subdissector should set pinfo->desegment_len to the length it needed if the payload is
+ * not enough for it to dissect.
+ * @param subdissector_tree The tree to be passed to subdissector.
+ * @param subdissector_data The data argument to be passed to subdissector.
+ * @param label The name of the data being reassembling. It can just be the name of protocol (ProtoA), for
+ * example, "[ProtoA segment of a reassembled PDU]".
+ * @param frag_hf_items The fragment field items for displaying fragment and reassembly information in tree. Please
+ * refer to process_reassembled_data().
+ * @param hf_segment_data The field item to show something like "ProtoA segment data (123 bytes)".
+ *
+ * @return Handled data length. Just equal to the length argument now.
+ */
+WS_DLL_PUBLIC gint
+reassemble_streaming_data_and_call_subdissector(
+ tvbuff_t* tvb, packet_info* pinfo, guint offset, gint length,
+ proto_tree* segment_tree, proto_tree* reassembled_tree, reassembly_table streaming_reassembly_table,
+ streaming_reassembly_info_t* reassembly_info, guint64 cur_frame_num,
+ dissector_handle_t subdissector_handle, proto_tree* subdissector_tree, void* subdissector_data,
+ const char* label, const fragment_items* frag_hf_items, int hf_segment_data
+);
+
+/**
+ * Return a 64 bits virtual frame number that is identified as follows:
+ *
+ * +--- 32 bits ---+--------- 8 bits -------+----- 24 bits --------------+
+ * | pinfo->num | pinfo->curr_layer_num | tvb->raw_offset + offset |
+ * +---------------------------------------------------------------------+
+ *
+ * This allows for a single virtual frame to be uniquely identified across a capture with the
+ * added benefit that the number will always be increasing from the previous virtual frame so
+ * we can use "<" and ">" comparisons to determine before and after in time.
+ *
+ * This frame number similar to HTTP2 frame number.
+ */
+static inline guint64
+get_virtual_frame_num64(tvbuff_t* tvb, packet_info* pinfo, gint offset)
+{
+ return (((guint64)pinfo->num) << 32) + (((guint64)pinfo->curr_layer_num) << 24)
+ + ((guint64)tvb_raw_offset(tvb) + offset);
+}
+
+/**
+ * How many additional bytes are still expected to complete this reassembly?
+ *
+ * @return How many additional bytes are expected to complete this reassembly.
+ * It may also be DESEGMENT_ONE_MORE_SEGMENT.
+ * 0 means this reassembly is completed.
+ */
+WS_DLL_PUBLIC gint
+additional_bytes_expected_to_complete_reassembly(streaming_reassembly_info_t* reassembly_info);
+
+/* ========================================================================= */
+
+#endif