Don't wire into the reassembly code the notion that reassemblies should

be done on flows from one address to another; reassembly for protocols
running atop TCP should be done on flows from one TCP endpoint to
another.

We do this by:

	adding "reassembly table" as a data structure;

	associating hash tables for both in-progress reassemblies and
	completed reassemblies with that data structure (currently, not
	all reassemblies use the latter; they might keep completed
	reassemblies in the first table);

	having functions to create and destroy keys in that table;

	offering standard routines for doing address-based and
	address-and-port-based flow processing, so that dissectors not
	needing their own specialized flow processing can just use them.

This fixes some mis-reassemblies of NIS YPSERV YPALL responses (where
the second YPALL response is processed as if it were a continuation of
a previous response between different endpoints, even though said
response is already reassembled), and also allows the DCE RPC-specific
stuff to be moved out of epan/reassembly.c into the DCE RPC dissector.

svn path=/trunk/; revision=48491

2 files changed, 22 insertions, 23 deletions

diff --git a/asn1/t38/packet-t38-template.c b/asn1/t38/packet-t38-template.c
index cbe63ea50a..312d42180b 100644
--- a/asn1/t38/packet-t38-template.c
+++ b/asn1/t38/packet-t38-template.c
@@ -148,7 +148,7 @@ static gboolean primary_part = TRUE;
 static guint32 seq_number = 0;
 
 /* Tables for reassembly of Data fragments. */
-static GHashTable *data_fragment_table = NULL;
+static reassembly_table data_reassembly_table;
 
 static const fragment_items data_frag_items = {
 	/* Fragment subtrees */
@@ -203,8 +203,9 @@ static t38_packet_info *t38_info=NULL;
 
 static void t38_defragment_init(void)
 {
-	/* Init reassemble tables */
-	fragment_table_init(&data_fragment_table);
+	/* Init reassembly table */
+	reassembly_table_init(&data_reassembly_table,
+                              &addresses_reassembly_table_functions);
 }
 
 
@@ -289,21 +290,14 @@ void t38_add_address(packet_info *pinfo,
 
 
 fragment_data *
-force_reassemble_seq(packet_info *pinfo, guint32 id,
-	     GHashTable *fragment_table)
+force_reassemble_seq(reassembly_table *table, packet_info *pinfo, guint32 id)
 {
-	fragment_key key;
 	fragment_data *fd_head;
 	fragment_data *fd_i;
 	fragment_data *last_fd;
 	guint32 dfpos, size, packet_lost, burst_lost, seq_num;
 
-	/* create key to search hash with */
-	key.src = pinfo->src;
-	key.dst = pinfo->dst;
-	key.id  = id;
-
-	fd_head = (fragment_data *)g_hash_table_lookup(fragment_table, &key);
+	fd_head = fragment_get(table, pinfo, id, NULL);
 
 	/* have we already seen this frame ?*/
 	if (pinfo->fd->flags.visited) {
@@ -334,8 +328,8 @@ force_reassemble_seq(packet_info *pinfo, guint32 id,
 	}
 
 	/* we have received an entire packet, defragment it and
-     * free all fragments
-     */
+	 * free all fragments
+	 */
 	size=0;
 	last_fd=NULL;
 	for(fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
diff --git a/asn1/t38/t38.cnf b/asn1/t38/t38.cnf
index d5df9e8b6a..0a81847f06 100644
--- a/asn1/t38/t38.cnf
+++ b/asn1/t38/t38.cnf
@@ -79,13 +79,15 @@ VAL_PTR=&Data_Field_field_type_value
 
             /* if reass_start_seqnum=-1 it means we have received the end of the fragmente, without received any fragment data */
             if (p_t38_packet_conv_info->reass_start_seqnum != -1) {
-                frag_msg = fragment_add_seq(tvb, offset, actx->pinfo,
+                frag_msg = fragment_add_seq(&data_reassembly_table, /* reassembly table */
+                    tvb, offset, actx->pinfo,
                     p_t38_packet_conv_info->reass_ID, /* ID for fragments belonging together */
-                    data_fragment_table, /* list of message fragments */
+                    NULL,
                     seq_number + Data_Field_item_num - (guint32)p_t38_packet_conv_info->reass_start_seqnum + (guint32)p_t38_packet_conv_info->additional_hdlc_data_field_counter,  /* fragment sequence number */
                     /*0,*/
                     0, /* fragment length */
-                    FALSE); /* More fragments */
+                    FALSE, /* More fragments */
+                    0);
                 if ( Data_Field_field_type_value == 7 ) {
                     /* if there was packet lost or other errors during the defrag then frag_msg is NULL. This could also means
                      * there are out of order packets (e.g, got the tail frame t4-non-ecm-sig-end before the last fragment),
@@ -93,9 +95,9 @@ VAL_PTR=&Data_Field_field_type_value
                      * and get some stat, like packet lost and burst number of packet lost
                     */
                     if (!frag_msg) {
-                        force_reassemble_seq(actx->pinfo,
-                            p_t38_packet_conv_info->reass_ID, /* ID for fragments belonging together */
-                            data_fragment_table /* list of message fragments */
+                        force_reassemble_seq(&data_reassembly_table, /* reassembly table */
+                            actx->pinfo,
+                            p_t38_packet_conv_info->reass_ID /* ID for fragments belonging together */
                         );
                     } else {
                         col_append_str(actx->pinfo->cinfo, COL_INFO, " (t4-data Reassembled: No packet lost)");
@@ -201,12 +203,15 @@ VAL_PTR=&Data_Field_field_type_value
                      p_t38_conv_info->additional_hdlc_data_field_counter =  p_t38_packet_conv_info->additional_hdlc_data_field_counter;
                    }
 	    }
-            frag_msg = fragment_add_seq(value_tvb, 0, actx->pinfo,
+            frag_msg = fragment_add_seq(&data_reassembly_table,
+                value_tvb, 0,
+                actx->pinfo,
                 p_t38_packet_conv_info->reass_ID, /* ID for fragments belonging together */
-                data_fragment_table, /* list of message fragments */
+                NULL,
                 seq_number - (guint32)p_t38_packet_conv_info->reass_start_seqnum + (guint32)p_t38_packet_conv_info->additional_hdlc_data_field_counter, /* fragment sequence number */
                 value_len, /* fragment length */
-                TRUE); /* More fragments */
+                TRUE, /* More fragments */
+                0);
             p_t38_packet_conv_info->seqnum_prev_data_field = (gint32)seq_number;
             process_reassembled_data(tvb, offset, actx->pinfo,
                         "Reassembled T38", frag_msg, &data_frag_items, NULL, tree);