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Add GUID dissector table support. 

It seems like DCE/RPC could benefit from a GUID dissector table, where a dissector can register it's GUID with a dissector handle.   So here is a basic start.

Change-Id: Id407117687a1a648d87f6f99c2ecbf858d8c0911
Reviewed-on: https://code.wireshark.org/review/4718
Reviewed-by: Michael Mann <mmann78@netscape.net>
This commit is contained in:
Michael Mann 2014-10-15 23:39:23 -04:00
parent 4f04a3cc31
commit 89c96d2772
2 changed files with 176 additions and 2 deletions
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143
epan/packet.c
View File

@ -1555,6 +1555,124 @@ dissector_handle_t dissector_get_custom_table_handle(dissector_table_t sub_disse
return NULL;
}
/* Add an entry to a guid dissector table. */
void dissector_add_guid(const char *name, guid_key* guid_val, dissector_handle_t handle)
{
dissector_table_t sub_dissectors;
dtbl_entry_t *dtbl_entry;
sub_dissectors = find_dissector_table(name);
/*
* Make sure the dissector table exists.
*/
if (sub_dissectors == NULL) {
fprintf(stderr, "OOPS: dissector table \"%s\" doesn't exist\n",
name);
fprintf(stderr, "Protocol being registered is \"%s\"\n",
proto_get_protocol_long_name(handle->protocol));
if (getenv("WIRESHARK_ABORT_ON_DISSECTOR_BUG") != NULL)
abort();
return;
}
/* sanity checks */
g_assert(handle!=NULL);
if (sub_dissectors->type != FT_GUID) {
g_assert_not_reached();
}
dtbl_entry = (dtbl_entry_t *)g_malloc(sizeof (dtbl_entry_t));
dtbl_entry->current = handle;
dtbl_entry->initial = dtbl_entry->current;
/* do the table insertion */
g_hash_table_insert( sub_dissectors->hash_table,
guid_val, (gpointer)dtbl_entry);
/*
* Now add it to the list of handles that could be used with this
* table, because it *is* being used with this table.
*/
dissector_add_handle(name, handle);
}
/* Look for a given value in a given guid dissector table and, if found,
call the dissector with the arguments supplied, and return TRUE,
otherwise return FALSE. */
int dissector_try_guid_new(dissector_table_t sub_dissectors,
guid_key* guid_val, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, const gboolean add_proto_name, void *data)
{
dtbl_entry_t *dtbl_entry;
struct dissector_handle *handle;
int len;
dtbl_entry = (dtbl_entry_t *)g_hash_table_lookup(sub_dissectors->hash_table, guid_val);
if (dtbl_entry != NULL) {
/*
* Is there currently a dissector handle for this entry?
*/
handle = dtbl_entry->current;
if (handle == NULL) {
/*
* No - pretend this dissector didn't exist,
* so that other dissectors might have a chance
* to dissect this packet.
*/
return 0;
}
/*
* Save the current value of "pinfo->match_uint",
* set it to the uint_val that matched, call the
* dissector, and restore "pinfo->match_uint".
*/
len = call_dissector_work(handle, tvb, pinfo, tree, add_proto_name, data);
/*
* If a new-style dissector returned 0, it means that
* it didn't think this tvbuff represented a packet for
* its protocol, and didn't dissect anything.
*
* Old-style dissectors can't reject the packet.
*
* 0 is also returned if the protocol wasn't enabled.
*
* If the packet was rejected, we return 0, so that
* other dissectors might have a chance to dissect this
* packet, otherwise we return the dissected length.
*/
return len;
}
return 0;
}
int dissector_try_guid(dissector_table_t sub_dissectors,
guid_key* guid_val, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
return dissector_try_guid_new(sub_dissectors, guid_val, tvb, pinfo, tree, TRUE, NULL);
}
/** Look for a given value in a given guid dissector table and, if found,
* return the current dissector handle for that value.
*
* @param[in] sub_dissectors Dissector table to search.
* @param[in] uint_val Value to match, e.g. the port number for the TCP dissector.
* @return The matching dissector handle on success, NULL if no match is found.
*/
dissector_handle_t dissector_get_guid_handle(
dissector_table_t const sub_dissectors, guid_key* guid_val)
{
dtbl_entry_t *dtbl_entry;
dtbl_entry = (dtbl_entry_t *)g_hash_table_lookup(sub_dissectors->hash_table, guid_val);
if (dtbl_entry != NULL)
return dtbl_entry->current;
else
return NULL;
}
dissector_handle_t
dtbl_entry_get_handle (dtbl_entry_t *dtbl_entry)
@ -1637,6 +1755,24 @@ dissector_table_get_type(dissector_table_t dissector_table) {
return dissector_table->type;
}
static gint
uuid_equal(gconstpointer k1, gconstpointer k2)
{
const guid_key *key1 = (const guid_key *)k1;
const guid_key *key2 = (const guid_key *)k2;
return ((memcmp(&key1->guid, &key2->guid, sizeof (e_guid_t)) == 0)
&& (key1->ver == key2->ver));
}
static guint
uuid_hash(gconstpointer k)
{
const guid_key *key = (const guid_key *)k;
/* This isn't perfect, but the Data1 part of these is almost always
unique. */
return key->guid.data1;
}
/**************************************************/
/* */
/* Routines to walk dissector tables */
@ -1915,7 +2051,12 @@ register_dissector_table(const char *name, const char *ui_name, const ftenum_t t
&g_free,
&g_free );
break;
case FT_GUID:
sub_dissectors->hash_table = g_hash_table_new_full( uuid_hash,
uuid_equal,
NULL,
&g_free );
break;
default:
g_assert_not_reached();
}

35
epan/packet.h
View File

@ -29,6 +29,7 @@
#include "frame_data.h"
#include "packet_info.h"
#include "column-utils.h"
#include "guid-utils.h"
#include "tfs.h"
#include "ws_symbol_export.h"
@ -235,7 +236,7 @@ WS_DLL_PUBLIC int get_dissector_table_param(const char *name);
WS_DLL_PUBLIC void dissector_dump_dissector_tables(void);
/* Add an entry to a uint dissector table. */
WS_DLL_PUBLIC void dissector_add_uint(const char *abbrev, const guint32 pattern,
WS_DLL_PUBLIC void dissector_add_uint(const char *name, const guint32 pattern,
dissector_handle_t handle);
/* Add an range of entries to a uint dissector table. */
@ -350,7 +351,39 @@ WS_DLL_PUBLIC void dissector_add_custom_table_handle(const char *name, void *pat
*/
WS_DLL_PUBLIC dissector_handle_t dissector_get_custom_table_handle(
dissector_table_t sub_dissectors, void *key);
/* Key for GUID dissector tables. This is based off of DCE/RPC needs
so some dissector tables may not need the ver portion of the hash
*/
typedef struct _guid_key {
e_guid_t guid;
guint16 ver;
} guid_key;
/* Add an entry to a guid dissector table. */
WS_DLL_PUBLIC void dissector_add_guid(const char *name, guid_key* guid_val,
dissector_handle_t handle);
/* Look for a given value in a given guid dissector table and, if found,
call the dissector with the arguments supplied, and return TRUE,
otherwise return FALSE. */
WS_DLL_PUBLIC int dissector_try_guid(dissector_table_t sub_dissectors,
guid_key* guid_val, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
/* Look for a given value in a given guid dissector table and, if found,
call the dissector with the arguments supplied, and return TRUE,
otherwise return FALSE. */
WS_DLL_PUBLIC int dissector_try_guid_new(dissector_table_t sub_dissectors,
guid_key* guid_val, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, const gboolean add_proto_name, void *data);
/** Look for a given value in a given guid dissector table and, if found,
* return the current dissector handle for that value.
*
* @param[in] sub_dissectors Dissector table to search.
* @param[in] uint_val Value to match, e.g. the port number for the TCP dissector.
* @return The matching dissector handle on success, NULL if no match is found.
*/
WS_DLL_PUBLIC dissector_handle_t dissector_get_guid_handle(
dissector_table_t const sub_dissectors, guid_key* guid_val);
/* Add a handle to the list of handles that *could* be used with this
table. That list is used by the "Decode As"/"-d" code in the UI. */