Support for dissectors of protocols running atop DCE RPC registering

themselves with the DCE RPC dissector, and support for some of the
protocols atop DCE RPC that are part of DCE RPC, from Todd Sabin.

svn path=/trunk/; revision=3681

1 files changed, 541 insertions, 174 deletions

diff --git a/packet-dcerpc.c b/packet-dcerpc.c
index 9534a23d3f..3666333429 100644
--- a/packet-dcerpc.c
+++ b/packet-dcerpc.c
@@ -2,10 +2,10 @@
  * Routines for DCERPC packet disassembly
  * Copyright 2001, Todd Sabin <tas@webspan.net>
  *
- * $Id: packet-dcerpc.c,v 1.5 2001/06/18 02:17:45 guy Exp $
+ * $Id: packet-dcerpc.c,v 1.6 2001/07/11 01:25:45 guy Exp $
  *
  * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
  * Copyright 1998 Gerald Combs
  * 
  * This program is free software; you can redistribute it and/or
@@ -37,6 +37,7 @@
 #include <glib.h>
 #include "packet.h"
 #include "packet-dcerpc.h"
+#include "conversation.h"
 
 static const value_string pckt_vals[] = {
     { 0, "Request"},
@@ -92,6 +93,7 @@ static int hf_dcerpc_cn_ctx_id = -1;
 static int hf_dcerpc_cn_num_trans_items = -1;
 static int hf_dcerpc_cn_bind_if_id = -1;
 static int hf_dcerpc_cn_bind_if_ver = -1;
+static int hf_dcerpc_cn_bind_if_ver_minor = -1;
 static int hf_dcerpc_cn_bind_trans_id = -1;
 static int hf_dcerpc_cn_bind_trans_ver = -1;
 static int hf_dcerpc_cn_alloc_hint = -1;
@@ -99,6 +101,7 @@ static int hf_dcerpc_cn_sec_addr_len = -1;
 static int hf_dcerpc_cn_num_results = -1;
 static int hf_dcerpc_cn_ack_result = -1;
 static int hf_dcerpc_cn_ack_reason = -1;
+static int hf_dcerpc_cn_cancel_count = -1;
 static int hf_dcerpc_dg_flags1 = -1;
 static int hf_dcerpc_dg_flags1_rsrvd_01 = -1;
 static int hf_dcerpc_dg_flags1_last_frag = -1;
@@ -137,7 +140,224 @@ static gint ett_dcerpc_cn_flags = -1;
 static gint ett_dcerpc_dg_flags1 = -1;
 static gint ett_dcerpc_dg_flags2 = -1;
 
+/*
+ * Subdissectors
+ */
+
+/* the registered subdissectors */
+static GHashTable *dcerpc_uuids;
+
+typedef struct _dcerpc_uuid_key {
+    e_uuid_t uuid;
+    guint16 ver;
+} dcerpc_uuid_key;
+
+typedef struct _dcerpc_uuid_value {
+    int proto;
+    int ett;
+    gchar *name;
+    dcerpc_sub_dissector *procs;
+} dcerpc_uuid_value;
+
+static gint
+dcerpc_uuid_equal (gconstpointer k1, gconstpointer k2)
+{
+    dcerpc_uuid_key *key1 = (dcerpc_uuid_key *)k1;
+    dcerpc_uuid_key *key2 = (dcerpc_uuid_key *)k2;
+    return ((memcmp (&key1->uuid, &key2->uuid, sizeof (e_uuid_t)) == 0)
+            && (key1->ver == key2->ver));
+}
+
+static guint
+dcerpc_uuid_hash (gconstpointer k)
+{
+    dcerpc_uuid_key *key = (dcerpc_uuid_key *)k;
+    /* This isn't perfect, but the Data1 part of these is almost always
+       unique. */
+    return key->uuid.Data1;
+}
+
+void
+dcerpc_init_uuid (int proto, int ett, e_uuid_t *uuid, guint16 ver,
+                  dcerpc_sub_dissector *procs)
+{
+    dcerpc_uuid_key *key = g_malloc (sizeof (*key));
+    dcerpc_uuid_value *value = g_malloc (sizeof (*value));
+
+    key->uuid = *uuid;
+    key->ver = ver;
+
+    value->proto = proto;
+    value->ett = ett;
+    value->name = proto_get_protocol_short_name (proto);
+    value->procs = procs;
+
+    g_hash_table_insert (dcerpc_uuids, key, value);
+}
+
+
+/*
+ * To keep track of ctx_id mappings.  Should really use some
+ * generic conversation support instead.
+ */
+static GHashTable *dcerpc_convs;
+
+typedef struct _dcerpc_conv_key {
+    conversation_t *conv;
+    guint16 ctx_id;
+} dcerpc_conv_key;
+
+static GMemChunk *dcerpc_conv_key_chunk;
+
+typedef struct _dcerpc_conv_value {
+    e_uuid_t uuid;
+    guint16 ver;
+} dcerpc_conv_value;
+
+static GMemChunk *dcerpc_conv_value_chunk;
+
+static gint
+dcerpc_conv_equal (gconstpointer k1, gconstpointer k2)
+{
+    dcerpc_conv_key *key1 = (dcerpc_conv_key *)k1;
+    dcerpc_conv_key *key2 = (dcerpc_conv_key *)k2;
+    return (key1->conv == key2->conv
+            && key1->ctx_id == key2->ctx_id);
+}
+
+static guint
+dcerpc_conv_hash (gconstpointer k)
+{
+    dcerpc_conv_key *key = (dcerpc_conv_key *)k;
+    return ((guint)key->conv) + key->ctx_id;
+}
+
+
+
+/*
+ * To keep track of callid mappings.  Should really use some generic
+ * conversation support instead.
+ */
+static GHashTable *dcerpc_calls;
+
+typedef struct _dcerpc_call_key {
+    conversation_t *conv;
+    guint32 call_id;
+} dcerpc_call_key;
 
+static GMemChunk *dcerpc_call_key_chunk;
+
+typedef struct _dcerpc_call_value {
+    e_uuid_t uuid;
+    guint16 ver;
+    guint16 opnum;
+} dcerpc_call_value;
+
+static GMemChunk *dcerpc_call_value_chunk;
+
+static gint
+dcerpc_call_equal (gconstpointer k1, gconstpointer k2)
+{
+    dcerpc_call_key *key1 = (dcerpc_call_key *)k1;
+    dcerpc_call_key *key2 = (dcerpc_call_key *)k2;
+    return (key1->conv == key2->conv
+            && key1->call_id == key2->call_id);
+}
+
+static guint
+dcerpc_call_hash (gconstpointer k)
+{
+    dcerpc_call_key *key = (dcerpc_call_key *)k;
+    return ((guint32)key->conv) ^ key->call_id;
+}
+
+static void
+dcerpc_call_add_map (guint32 call_id, conversation_t *conv,
+                     guint16 opnum, guint16 ver, e_uuid_t *uuid)
+{
+    dcerpc_call_key *key = g_mem_chunk_alloc (dcerpc_call_key_chunk);
+    dcerpc_call_value *value = g_mem_chunk_alloc (dcerpc_call_value_chunk);
+
+    key->call_id = call_id;
+    key->conv = conv;
+    value->uuid = *uuid;
+    value->ver = ver;
+    value->opnum = opnum;
+    g_hash_table_insert (dcerpc_calls, key, value);
+}
+
+static dcerpc_call_value*
+dcerpc_call_lookup (guint32 call_id, conversation_t *conv)
+{
+    dcerpc_call_key key;
+
+    key.call_id = call_id;
+    key.conv = conv;
+    return g_hash_table_lookup (dcerpc_calls, &key);
+}
+
+
+/*
+ * Utility functions.  Modeled after packet-rpc.c
+ */
+
+int
+dissect_dcerpc_uint8 (tvbuff_t *tvb, gint offset, packet_info *pinfo,
+                      proto_tree *tree, char *drep, 
+                      int hfindex, guint8 *pdata)
+{
+    guint8 data;
+
+    data = tvb_get_guint8 (tvb, offset);
+    if (tree) {
+        proto_tree_add_item (tree, hfindex, tvb, offset, 1, (drep[0] & 0x10));
+    }
+    if (pdata)
+        *pdata = data;
+    return offset + 1;
+}
+
+int
+dissect_dcerpc_uint16 (tvbuff_t *tvb, gint offset, packet_info *pinfo,
+                       proto_tree *tree, char *drep, 
+                       int hfindex, guint16 *pdata)
+{
+    guint16 data;
+
+    data = ((drep[0] & 0x10)
+            ? tvb_get_letohs (tvb, offset)
+            : tvb_get_ntohs (tvb, offset));
+    
+    if (tree) {
+        proto_tree_add_item (tree, hfindex, tvb, offset, 2, (drep[0] & 0x10));
+    }
+    if (pdata)
+        *pdata = data;
+    return offset + 2;
+}
+
+int
+dissect_dcerpc_uint32 (tvbuff_t *tvb, gint offset, packet_info *pinfo,
+                       proto_tree *tree, char *drep, 
+                       int hfindex, guint32 *pdata)
+{
+    guint32 data;
+
+    data = ((drep[0] & 0x10)
+            ? tvb_get_letohl (tvb, offset)
+            : tvb_get_ntohl (tvb, offset));
+    
+    if (tree) {
+        proto_tree_add_item (tree, hfindex, tvb, offset, 4, (drep[0] & 0x10));
+    }
+    if (pdata)
+        *pdata = data;
+    return offset+4;
+}
+
+/*
+ * a couple simpler things
+ */
 guint16
 dcerpc_tvb_get_ntohs (tvbuff_t *tvb, gint offset, char *drep)
 {
@@ -171,122 +391,166 @@ dcerpc_tvb_get_uuid (tvbuff_t *tvb, gint offset, char *drep, e_uuid_t *uuid)
     }
 }
 
+static int
+dcerpc_try_handoff (packet_info *pinfo, proto_tree *tree,
+                    tvbuff_t *tvb, gint offset,
+                    e_uuid_t *uuid, guint16 ver, 
+                    guint16 opnum, gboolean is_rqst)
+{
+    dcerpc_uuid_key key;
+    dcerpc_uuid_value *sub_proto;
+    proto_item *sub_item;
+    proto_tree *sub_tree;
+    dcerpc_sub_dissector *proc;
+    gchar *name = NULL;
+
+    key.uuid = *uuid;
+    key.ver = ver;
+
+    
+    if ((sub_proto = g_hash_table_lookup (dcerpc_uuids, &key)) == 0)
+        return -1;
+
+    if (tree) {
+        sub_item = proto_tree_add_item (tree, sub_proto->proto, tvb, offset, 
+                                        tvb_length (tvb) - offset, FALSE);
+        if (sub_item) {
+            sub_tree = proto_item_add_subtree (sub_item, sub_proto->ett);
+        }
+        
+    }
+    for (proc = sub_proto->procs; proc->name; proc++) {
+        if (proc->num == opnum) {
+            name = proc->name;
+            break;
+        }
+    }
+
+    if (!name)
+        name = "Unknown?!";
+
+    if (check_col (pinfo->fd, COL_INFO)) {
+        col_add_fstr (pinfo->fd, COL_INFO, "%s %s:%s(...)",
+                      is_rqst ? "rqst" : "rply",
+                      sub_proto->name, name);
+    }
+
+    if (check_col (pinfo->fd, COL_PROTOCOL)) {
+        col_set_str (pinfo->fd, COL_PROTOCOL, sub_proto->name);
+    }
+    // FIXME: call approp. dissector
+    return 0;
+}
+
+
+/*
+ * Connection oriented packet types
+ */
 
 static void
 dissect_dcerpc_cn_bind (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerpc_tree,
                         e_dce_cn_common_hdr_t *hdr)
 {
-    guint16 max_xmit, max_recv;
-    guint32 assoc_group;
+    conversation_t *conv = NULL;
+    dcerpc_conv_key *key;
+    dcerpc_conv_value *value;
     guint8 num_ctx_items;
     guint16 ctx_id;
     guint16 num_trans_items;
     e_uuid_t if_id;
     e_uuid_t trans_id;
-    guint32 if_ver, trans_ver;
+    guint32 trans_ver;
+    guint16 if_ver, if_ver_minor;
     int offset = 16;
 
-    max_xmit = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_max_xmit, NULL);
 
-    max_recv = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_max_recv, NULL);
 
-    assoc_group = dcerpc_tvb_get_ntohl (tvb, offset, hdr->drep);
-    offset += 4;
+    offset = dissect_dcerpc_uint32 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_assoc_group, NULL);
 
-    num_ctx_items = tvb_get_guint8 (tvb, offset);
-    offset++;
+    offset = dissect_dcerpc_uint8 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_num_ctx_items, &num_ctx_items);
 
     /* padding */
     offset += 3;
 
-    ctx_id = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_ctx_id, &ctx_id);
 
-    num_trans_items = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_num_trans_items, &num_trans_items);
 
     dcerpc_tvb_get_uuid (tvb, offset, hdr->drep, &if_id);
-    offset += 16;
-
-    if_ver = dcerpc_tvb_get_ntohl (tvb, offset, hdr->drep);
-    offset += 4;
-
-    dcerpc_tvb_get_uuid (tvb, offset, hdr->drep, &trans_id);
-    offset += 16;
-
-    trans_ver = dcerpc_tvb_get_ntohl (tvb, offset, hdr->drep);
-    offset += 4;
-
-    if (check_col (pinfo->fd, COL_INFO)) {
-        col_add_fstr (pinfo->fd, COL_INFO, "Bind: UUID %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x ver %d",
-                         if_id.Data1, if_id.Data2, if_id.Data3,
-                         if_id.Data4[0], if_id.Data4[1],
-                         if_id.Data4[2], if_id.Data4[3],
-                         if_id.Data4[4], if_id.Data4[5],
-                         if_id.Data4[6], if_id.Data4[7],
-                         if_ver);
-    }
-
     if (dcerpc_tree) {
-        offset = 16;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_max_xmit, tvb, offset, 2, max_xmit);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_max_recv, tvb, offset, 2, max_recv);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_assoc_group, tvb, offset, 4, assoc_group);
-        offset += 4;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_num_ctx_items, tvb, offset, 1, num_ctx_items);
-        offset++;
-
-        /* padding */
-        offset += 3;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_ctx_id, tvb, offset, 2, ctx_id);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_num_trans_items, tvb, offset, 2, num_trans_items);
-        offset += 2;
-
         proto_tree_add_string_format (dcerpc_tree, hf_dcerpc_cn_bind_if_id, tvb,
                                       offset, 16, "HMMM",
                                       "Interface UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                                       if_id.Data1, if_id.Data2, if_id.Data3,
-                                      if_id.Data4[0],
-                                      if_id.Data4[1],
-                                      if_id.Data4[2],
-                                      if_id.Data4[3],
-                                      if_id.Data4[4],
-                                      if_id.Data4[5],
-                                      if_id.Data4[6],
-                                      if_id.Data4[7]);
-        offset += 16;
+                                      if_id.Data4[0], if_id.Data4[1],
+                                      if_id.Data4[2], if_id.Data4[3],
+                                      if_id.Data4[4], if_id.Data4[5],
+                                      if_id.Data4[6], if_id.Data4[7]);
+    }
+    offset += 16;
 
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_bind_if_ver, tvb, offset, 4, if_ver);
-        offset += 4;
+    if (hdr->drep[0] & 0x10) {
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                        hf_dcerpc_cn_bind_if_ver, &if_ver);
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                        hf_dcerpc_cn_bind_if_ver_minor, &if_ver_minor);
+    } else {
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                        hf_dcerpc_cn_bind_if_ver_minor, &if_ver_minor);
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                        hf_dcerpc_cn_bind_if_ver, &if_ver);
+    }
 
+    dcerpc_tvb_get_uuid (tvb, offset, hdr->drep, &trans_id);
+    if (dcerpc_tree) {
         proto_tree_add_string_format (dcerpc_tree, hf_dcerpc_cn_bind_trans_id, tvb,
                                       offset, 16, "HMMM",
                                       "Transfer Syntax: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                                       trans_id.Data1, trans_id.Data2, trans_id.Data3,
-                                      trans_id.Data4[0],
-                                      trans_id.Data4[1],
-                                      trans_id.Data4[2],
-                                      trans_id.Data4[3],
-                                      trans_id.Data4[4],
-                                      trans_id.Data4[5],
-                                      trans_id.Data4[6],
-                                      trans_id.Data4[7]);
-        offset += 16;
+                                      trans_id.Data4[0], trans_id.Data4[1],
+                                      trans_id.Data4[2], trans_id.Data4[3],
+                                      trans_id.Data4[4], trans_id.Data4[5],
+                                      trans_id.Data4[6], trans_id.Data4[7]);
+    }
+    offset += 16;
 
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_bind_trans_ver, tvb, offset, 4, trans_ver);
-        offset += 4;
+    offset = dissect_dcerpc_uint32 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_bind_trans_ver, &trans_ver);
+
+    if (check_col (pinfo->fd, COL_INFO)) {
+        col_add_fstr (pinfo->fd, COL_INFO, "%s: UUID %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x ver %d.%d",
+                      hdr->ptype == PDU_BIND ? "Bind" : "Alter Ctx",
+                      if_id.Data1, if_id.Data2, if_id.Data3,
+                      if_id.Data4[0], if_id.Data4[1],
+                      if_id.Data4[2], if_id.Data4[3],
+                      if_id.Data4[4], if_id.Data4[5],
+                      if_id.Data4[6], if_id.Data4[7],
+                      if_ver, if_ver_minor);
+    }
+    conv = find_conversation (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                              pinfo->srcport, pinfo->destport, 0);
+    if (conv == NULL) {
+        conv = conversation_new (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                                 pinfo->srcport, pinfo->destport, NULL, 0);
     }
+
+    key = g_mem_chunk_alloc (dcerpc_conv_key_chunk);
+    key->conv = conv;
+    key->ctx_id = ctx_id;
+
+    value = g_mem_chunk_alloc (dcerpc_conv_value_chunk);
+    value->uuid = if_id;
+    value->ver = if_ver;
+
+    g_hash_table_insert (dcerpc_convs, key, value);
 }
 
 static void
@@ -294,7 +558,6 @@ dissect_dcerpc_cn_bind_ack (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerp
                             e_dce_cn_common_hdr_t *hdr)
 {
     guint16 max_xmit, max_recv;
-    guint32 assoc_group;
     guint16 sec_addr_len;
     guint8 num_results;
     guint16 result = 0;
@@ -302,128 +565,77 @@ dissect_dcerpc_cn_bind_ack (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerp
 
     int offset = 16;
 
-    max_xmit = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_max_xmit, &max_xmit);
 
-    max_recv = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_max_recv, &max_recv);
 
-    assoc_group = dcerpc_tvb_get_ntohl (tvb, offset, hdr->drep);
-    offset += 4;
+    offset = dissect_dcerpc_uint32 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_assoc_group, NULL);
 
-    sec_addr_len = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2 + sec_addr_len;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_sec_addr_len, &sec_addr_len);
+    offset += sec_addr_len;
 
     if (offset % 4) {
         offset += 4 - offset % 4;
     }
 
-    num_results = tvb_get_guint8 (tvb, offset);
-    offset++;
+    offset = dissect_dcerpc_uint8 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                   hf_dcerpc_cn_num_results, &num_results);
 
     /* padding */
     offset += 3;
 
     if (num_results == 1) {
-        result = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-        offset += 2;
-        
-        reason = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-        offset += 2;
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, 
+                                        hdr->drep, hf_dcerpc_cn_ack_result,
+                                        &result);
+        offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, 
+                                        hdr->drep, hf_dcerpc_cn_ack_reason,
+                                        &reason);
     }
     
     if (check_col (pinfo->fd, COL_INFO)) {
         if (num_results == 1 && result == 0) {
-            col_add_fstr (pinfo->fd, COL_INFO, "Bind ack: accept  max_xmit: %d  max_recv: %d",
-                             max_xmit, max_recv);
-            
+            col_add_fstr (pinfo->fd, COL_INFO, "%s ack: accept  max_xmit: %d  max_recv: %d",
+                          hdr->ptype == PDU_BIND_ACK ? "Bind" : "Alter ctx",
+                          max_xmit, max_recv);
         } else {
             /* FIXME: should put in reason */
-            col_add_fstr (pinfo->fd, COL_INFO, "Bind ack: %s",
-                             result == 1 ? "User reject" :
-                             result == 2 ? "Provider reject" :
-                             "Unknown");
-        }
-    }
-
-    if (dcerpc_tree) {
-        offset = 16;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_max_xmit, tvb, offset, 2, max_xmit);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_max_recv, tvb, offset, 2, max_recv);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_assoc_group, tvb, offset, 4, assoc_group);
-        offset += 4;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_sec_addr_len, tvb, offset, 2, sec_addr_len);
-        offset +=2 + sec_addr_len;
-
-        if (offset % 4) {
-            offset += 4 - offset % 4;
-        }
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_num_results, tvb, offset, 1, num_results);
-        offset++;
-
-        /* padding */
-        offset += 3;
-
-        if (num_results == 1) {
-            proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_ack_result, tvb, offset, 2, result);
-            offset += 2;
-
-            proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_ack_reason, tvb, offset, 2, reason);
-            offset += 2;
+            col_add_fstr (pinfo->fd, COL_INFO, "%s ack: %s",
+                          hdr->ptype == PDU_BIND_ACK ? "Bind" : "Alter ctx",
+                          result == 1 ? "User reject" :
+                          result == 2 ? "Provider reject" :
+                          "Unknown");
         }
     }
 }
 
 static void
 dissect_dcerpc_cn_rqst (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerpc_tree,
-                        e_dce_cn_common_hdr_t *hdr)
+                        proto_tree *tree, e_dce_cn_common_hdr_t *hdr)
 {
-    guint32 alloc_hint;
+    conversation_t *conv;
     guint16 ctx_id;
     guint16 opnum;
     e_uuid_t obj_id;
 
     int offset = 16;
 
-    alloc_hint = dcerpc_tvb_get_ntohl (tvb, offset, hdr->drep);
-    offset += 4;
+    offset = dissect_dcerpc_uint32 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_alloc_hint, NULL);
 
-    ctx_id = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_ctx_id, &ctx_id);
 
-    opnum = dcerpc_tvb_get_ntohs (tvb, offset, hdr->drep);
-    offset += 2;
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_opnum, &opnum);
 
     if (hdr->flags & 0x80) {
         dcerpc_tvb_get_uuid (tvb, offset, hdr->drep, &obj_id);
-        offset += 16;
-    }
-
-    if (check_col (pinfo->fd, COL_INFO)) {
-        col_add_fstr (pinfo->fd, COL_INFO, "Request: opnum: %d  ctx_id:%d",
-                         opnum, ctx_id);
-    }
-
-    if (dcerpc_tree) {
-        offset = 16;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_alloc_hint, tvb, offset, 4, alloc_hint);
-        offset += 4;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_cn_ctx_id, tvb, offset, 2, ctx_id);
-        offset += 2;
-
-        proto_tree_add_uint (dcerpc_tree, hf_dcerpc_opnum, tvb, offset, 2, opnum);
-        offset += 2;
-
-        if (hdr->flags & 0x80) {
+        if (dcerpc_tree) {
             proto_tree_add_string_format (dcerpc_tree, hf_dcerpc_obj_id, tvb,
                                           offset, 16, "HMMM",
                                           "Object UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
@@ -436,7 +648,75 @@ dissect_dcerpc_cn_rqst (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerpc_tr
                                           obj_id.Data4[5],
                                           obj_id.Data4[6],
                                           obj_id.Data4[7]);
-            offset += 16;
+        }
+        offset += 16;
+    }
+
+    if (check_col (pinfo->fd, COL_INFO)) {
+        col_add_fstr (pinfo->fd, COL_INFO, "Request: opnum: %d  ctx_id:%d",
+                         opnum, ctx_id);
+    }
+
+    conv = find_conversation (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                              pinfo->srcport, pinfo->destport, 0);
+    if (!conv) {
+
+    } else {
+        dcerpc_conv_key key;
+        dcerpc_conv_value *value;
+
+        key.conv = conv;
+        key.ctx_id = ctx_id;
+
+        value = g_hash_table_lookup (dcerpc_convs, &key);
+        if (value) {
+            /* add an entry for this call, so we can catch the reply */
+            dcerpc_call_add_map (hdr->call_id, conv, opnum,
+                                 value->ver, &value->uuid);
+
+            /* handoff this call */
+            dcerpc_try_handoff (pinfo, tree, tvb, offset,
+                                &value->uuid, value->ver,
+                                opnum, TRUE);
+        }
+    }
+}
+
+static void
+dissect_dcerpc_cn_resp (tvbuff_t *tvb, packet_info *pinfo, proto_tree *dcerpc_tree,
+                        proto_tree *tree, e_dce_cn_common_hdr_t *hdr)
+{
+    conversation_t *conv;
+    guint16 ctx_id;
+
+    int offset = 16;
+
+    offset = dissect_dcerpc_uint32 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_alloc_hint, NULL);
+
+    offset = dissect_dcerpc_uint16 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                    hf_dcerpc_cn_ctx_id, &ctx_id);
+
+    offset = dissect_dcerpc_uint8 (tvb, offset, pinfo, dcerpc_tree, hdr->drep,
+                                   hf_dcerpc_cn_cancel_count, NULL);
+    /* padding */
+    offset++;
+
+    if (check_col (pinfo->fd, COL_INFO)) {
+        col_add_fstr (pinfo->fd, COL_INFO, "Response: call_id: %d  ctx_id:%d",
+                      hdr->call_id, ctx_id);
+    }
+
+    conv = find_conversation (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                              pinfo->srcport, pinfo->destport, 0);
+    if (!conv) {
+        /* no point in creating one here, really */
+    } else {
+        dcerpc_call_value *value = dcerpc_call_lookup (hdr->call_id, conv);
+        if (value) {
+            dcerpc_try_handoff (pinfo, tree, tvb, offset, 
+                                &value->uuid, value->ver,
+                                value->opnum, FALSE);
         }
     }
 }
@@ -526,15 +806,21 @@ dissect_dcerpc_cn (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
      */
     switch (hdr.ptype) {
     case PDU_BIND:
+    case PDU_ALTER:
         dissect_dcerpc_cn_bind (tvb, pinfo, dcerpc_tree, &hdr);
         break;
 
     case PDU_BIND_ACK:
+    case PDU_ALTER_ACK:
         dissect_dcerpc_cn_bind_ack (tvb, pinfo, dcerpc_tree, &hdr);
         break;
 
     case PDU_REQ:
-        dissect_dcerpc_cn_rqst (tvb, pinfo, dcerpc_tree, &hdr);
+        dissect_dcerpc_cn_rqst (tvb, pinfo, dcerpc_tree, tree, &hdr);
+        break;
+
+    case PDU_RESP:
+        dissect_dcerpc_cn_resp (tvb, pinfo, dcerpc_tree, tree, &hdr);
         break;
 
     default:
@@ -556,6 +842,7 @@ dissect_dcerpc_dg (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     proto_tree *dg_flags2_tree = NULL;
     e_dce_dg_common_hdr_t hdr;
     int offset = 0;
+    conversation_t *conv;
 
     /*
      * Check if this looks like a CL DCERPC call.  All dg packets
@@ -722,16 +1009,89 @@ dissect_dcerpc_dg (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         proto_tree_add_uint (dcerpc_tree, hf_dcerpc_dg_serial_lo, tvb, offset, 1, hdr.serial_lo);
         offset++;
     }
+    /* 
+     * keeping track of the conversation shouldn't really be necessary
+     * for connectionless packets, because everything we need to know
+     * to dissect is in the header for each packet.  Unfortunately,
+     * Microsoft's implementation is buggy and often puts the
+     * completely wrong if_id in the header.  go figure.  So, keep
+     * track of the seqnum and use that if possible.  Note: that's not
+     * completely correct.  It should really be done based on both the
+     * activity_id and seqnum.  I haven't seen anywhere that it would
+     * make a difference, but for future reference...
+     */
+    conv = find_conversation (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                              pinfo->srcport, pinfo->destport, 0);
+    if (!conv) {
+        conv = conversation_new (&pinfo->src, &pinfo->dst, pinfo->ptype,
+                                 pinfo->srcport, pinfo->destport, NULL, 0);
+    }
+
     /*
      * Packet type specific stuff is next.
      */
+    switch (hdr.ptype) {
+    case PDU_REQ:
+        dcerpc_call_add_map (hdr.seqnum, conv, hdr.opnum,
+                             hdr.if_ver, &hdr.if_id);
+        dcerpc_try_handoff (pinfo, tree, tvb, offset,
+                            &hdr.if_id, hdr.if_ver, hdr.opnum, TRUE);
+        break;
+    case PDU_RESP:
+        {
+            dcerpc_call_value *v = dcerpc_call_lookup (hdr.seqnum, conv);
+            if (v) {
+                dcerpc_try_handoff (pinfo, tree, tvb, offset,
+                                    &v->uuid, v->ver, v->opnum, FALSE);
+            } else {
+                dcerpc_try_handoff (pinfo, tree, tvb, offset,
+                                    &hdr.if_id, hdr.if_ver, hdr.opnum, FALSE);
+            }
+        }
+        break;
+    }
 
     return TRUE;
 }
 
+static void
+dcerpc_init_protocol (void)
+{
+    if (dcerpc_convs)
+        g_hash_table_destroy (dcerpc_convs);
+    if (dcerpc_calls)
+        g_hash_table_destroy (dcerpc_calls);
+    if (dcerpc_conv_key_chunk)
+        g_mem_chunk_destroy (dcerpc_conv_key_chunk);
+    if (dcerpc_conv_value_chunk)
+        g_mem_chunk_destroy (dcerpc_conv_value_chunk);
+    if (dcerpc_call_key_chunk)
+        g_mem_chunk_destroy (dcerpc_call_key_chunk);
+    if (dcerpc_call_value_chunk)
+        g_mem_chunk_destroy (dcerpc_call_value_chunk);
+
+    dcerpc_convs = g_hash_table_new (dcerpc_conv_hash, dcerpc_conv_equal);
+    dcerpc_calls = g_hash_table_new (dcerpc_call_hash, dcerpc_call_equal);
+    dcerpc_conv_key_chunk = g_mem_chunk_new ("dcerpc_conv_key_chunk",
+                                             sizeof (dcerpc_conv_key),
+                                             200 * sizeof (dcerpc_conv_key),
+                                             G_ALLOC_ONLY);
+    dcerpc_conv_value_chunk = g_mem_chunk_new ("dcerpc_conv_value_chunk",
+                                             sizeof (dcerpc_conv_value),
+                                             200 * sizeof (dcerpc_conv_value),
+                                             G_ALLOC_ONLY);
+    dcerpc_call_key_chunk = g_mem_chunk_new ("dcerpc_call_key_chunk",
+                                             sizeof (dcerpc_call_key),
+                                             200 * sizeof (dcerpc_call_key),
+                                             G_ALLOC_ONLY);
+    dcerpc_call_value_chunk = g_mem_chunk_new ("dcerpc_call_value_chunk",
+                                             sizeof (dcerpc_call_value),
+                                             200 * sizeof (dcerpc_call_value),
+                                             G_ALLOC_ONLY);
+}
 
 void
-proto_register_dcerpc(void)
+proto_register_dcerpc (void)
 {
     static hf_register_info hf[] = {
         { &hf_dcerpc_ver,
@@ -779,7 +1139,9 @@ proto_register_dcerpc(void)
         { &hf_dcerpc_cn_bind_if_id,
           { "Interface UUID", "dcerpc.cn_bind_to_uuid", FT_STRING, BASE_NONE, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_cn_bind_if_ver,
-          { "Interface Ver", "dcerpc.cn_bind_if_ver", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL }},
+          { "Interface Ver", "dcerpc.cn_bind_if_ver", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
+        { &hf_dcerpc_cn_bind_if_ver_minor,
+          { "Interface Ver Minor", "dcerpc.cn_bind_if_ver_minor", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_cn_bind_trans_id,
           { "Transfer Syntax", "dcerpc.cn_bind_trans_id", FT_STRING, BASE_NONE, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_cn_bind_trans_ver,
@@ -794,6 +1156,8 @@ proto_register_dcerpc(void)
           { "Ack result", "dcerpc.cn_ack_result", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_cn_ack_reason,
           { "Ack reason", "dcerpc.cn_ack_reason", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
+        { &hf_dcerpc_cn_cancel_count,
+          { "Cancel count", "dcerpc.cn_cancel_count", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_dg_flags1,
           { "Flags1", "dcerpc.dg_flags1", FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL }},
         { &hf_dcerpc_dg_flags1_rsrvd_01,
@@ -871,10 +1235,13 @@ proto_register_dcerpc(void)
     proto_dcerpc = proto_register_protocol ("DCE RPC", "DCERPC", "dcerpc");
     proto_register_field_array (proto_dcerpc, hf, array_length (hf));
     proto_register_subtree_array (ett, array_length (ett));
+    register_init_routine (dcerpc_init_protocol);
+
+    dcerpc_uuids = g_hash_table_new (dcerpc_uuid_hash, dcerpc_uuid_equal);
 }
 
 void
-proto_reg_handoff_dcerpc(void)
+proto_reg_handoff_dcerpc (void)
 {
     heur_dissector_add ("tcp", dissect_dcerpc_cn, proto_dcerpc);
     heur_dissector_add ("udp", dissect_dcerpc_dg, proto_dcerpc);