Support table-based dissection of ROS operations.

This simplifies the generation of dissectors for ROS-based protocols using the asn2wrs #.TABLE directive.

See the P7 dissector for an example.


svn path=/trunk/; revision=23706

4 files changed, 145 insertions, 3 deletions

diff --git a/asn1/ros/Remote-Operations-Information-Objects.asn b/asn1/ros/Remote-Operations-Information-Objects.asn
index 8eeafd110b..40ae404177 100644
--- a/asn1/ros/Remote-Operations-Information-Objects.asn
+++ b/asn1/ros/Remote-Operations-Information-Objects.asn
@@ -1,7 +1,9 @@
 -- Generated by Asnp, the pretty-printer of France Telecom R&D (http://asn1.elibel.tm.fr/asnp/)
 -- Module Remote-Operations-Information-Objects (Rec. X.880:07/1994)
 Remote-Operations-Information-Objects {joint-iso-itu-t remote-operations(4)
-  informationObjects(5) version1(0)} DEFINITIONS ::=
+  informationObjects(5) version1(0)} DEFINITIONS 
+IMPLICIT TAGS -- WS: Don't know why I need to add this - but if it isn't,  the ROS operationCode is not successfully decoded - even though it doesn't have any tags! An asn2wrs issue?
+::=
 BEGIN
 
 -- exports everything
diff --git a/asn1/ros/packet-ros-template.c b/asn1/ros/packet-ros-template.c
index c4c2351934..bf7abe37fc 100644
--- a/asn1/ros/packet-ros-template.c
+++ b/asn1/ros/packet-ros-template.c
@@ -83,7 +83,9 @@ static gint ett_ros = -1;
 #include "packet-ros-ett.c"
 
 static dissector_table_t ros_oid_dissector_table=NULL;
+
 static GHashTable *oid_table=NULL;
+static GHashTable *protocol_table=NULL;
 static gint ett_ros_unknown = -1;
 
 void
@@ -97,13 +99,123 @@ register_ros_oid_dissector_handle(const char *oid, dissector_handle_t dissector,
 	  register_ber_oid_dissector_handle(oid, ros_handle, proto, name);
 }
 
+void
+register_ros_protocol_info(const char *oid, const ros_info_t *rinfo, int proto _U_, const char *name, gboolean uses_rtse)
+{
+	g_hash_table_insert(protocol_table, (gpointer)oid, (gpointer)rinfo);	
+	g_hash_table_insert(oid_table, (gpointer)oid, (gpointer)name);
+
+	if(!uses_rtse)
+	  /* if we are not using RTSE, then we must register ROS with BER (ACSE) */
+	  register_ber_oid_dissector_handle(oid, ros_handle, proto, name);
+}
+
+static new_dissector_t ros_lookup_opr_dissector(gint32 opcode, const ros_opr_t *operations, gboolean argument)
+{
+	/* we don't know what order asn2wrs/module definition is, so ... */
+	if(operations) {
+		for(;operations->arg_pdu != (new_dissector_t)(-1); operations++) 
+			if(operations->opcode == opcode) 
+				return argument ? operations->arg_pdu : operations->res_pdu;
+		
+	}
+	return NULL;
+}
+
+static new_dissector_t ros_lookup_err_dissector(gint32 errcode, const ros_err_t *errors)
+{
+	/* we don't know what order asn2wrs/module definition is, so ... */
+	if(errors) {
+		for(;errors->err_pdu != (new_dissector_t) (-1); errors++) {
+			if(errors->errcode == errcode) 
+				return errors->err_pdu;
+		}
+	}
+	return NULL;
+}
+
+
+static gboolean ros_try_string(const char *oid, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	ros_info_t *rinfo;
+	gint32     opcode = 0;
+	const gchar *opname = NULL;
+	const gchar *suffix = NULL;
+	int offset = 0;
+	new_dissector_t opdissector = NULL;
+	const value_string *lookup;
+	proto_item *item=NULL;
+	proto_tree *ros_tree=NULL;
+
+	if((rinfo = (ros_info_t*)g_hash_table_lookup(protocol_table, oid)) != NULL) {
+
+		if(tree){
+			item = proto_tree_add_item(tree, *(rinfo->proto), tvb, 0, -1, FALSE);
+			ros_tree = proto_item_add_subtree(item, *(rinfo->ett_proto));
+		}
+
+		if (check_col(pinfo->cinfo, COL_PROTOCOL))
+			col_set_str(pinfo->cinfo, COL_PROTOCOL, rinfo->name);
+
+		/* if this is a bind operation */
+		if((session->ros_op & ROS_OP_TYPE_MASK) == ROS_OP_BIND) {
+			/* use the in-built operation codes */
+			if((session->ros_op & ROS_OP_PDU_MASK) ==  ROS_OP_ERROR)
+				opcode = err_ros_bind;
+			else
+				opcode = op_ros_bind;				
+		} else 
+			/* otherwise just take the opcode */
+			opcode = session->ros_op & ROS_OP_OPCODE_MASK;
+
+		/* default lookup in the operations */
+		lookup = rinfo->opr_code_strings;
+
+		switch(session->ros_op & ROS_OP_PDU_MASK) {
+		case ROS_OP_ARGUMENT:	
+			opdissector = ros_lookup_opr_dissector(opcode, rinfo->opr_code_dissectors, TRUE);
+			suffix = "_argument";
+			break;
+		case ROS_OP_RESULT:	
+			opdissector = ros_lookup_opr_dissector(opcode, rinfo->opr_code_dissectors, FALSE);
+			suffix = "_result";
+			break;
+		case ROS_OP_ERROR:	
+			opdissector = ros_lookup_err_dissector(opcode, rinfo->err_code_dissectors);
+			lookup = rinfo->err_code_strings;
+			break;
+		default:
+			break;
+		}
+
+		if(opdissector) {
+
+			opname = val_to_str(opcode, lookup, "Unknown opcode (%d)");
+
+			if (check_col(pinfo->cinfo, COL_INFO)) {
+				col_set_str(pinfo->cinfo, COL_INFO, opname);
+				if(suffix)
+					col_append_fstr(pinfo->cinfo, COL_INFO, suffix);
+			}
+			
+			offset = (*opdissector)(tvb, pinfo, ros_tree);
+
+			return TRUE;
+		}
+	}
+
+	return FALSE;
+}
+
 static int
 call_ros_oid_callback(const char *oid, tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
 {
 	tvbuff_t *next_tvb;
 
 	next_tvb = tvb_new_subset(tvb, offset, tvb_length_remaining(tvb, offset), tvb_reported_length_remaining(tvb, offset));
-	if(!dissector_try_string(ros_oid_dissector_table, oid, next_tvb, pinfo, tree)){
+
+	if(!ros_try_string(oid, next_tvb, pinfo, tree) &&
+           !dissector_try_string(ros_oid_dissector_table, oid, next_tvb, pinfo, tree)){
 		proto_item *item=NULL;
 		proto_tree *next_tree=NULL;
 
@@ -401,6 +513,7 @@ void proto_register_ros(void) {
 
   ros_oid_dissector_table = register_dissector_table("ros.oid", "ROS OID Dissectors", FT_STRING, BASE_NONE);
   oid_table=g_hash_table_new(g_str_hash, g_str_equal);
+  protocol_table=g_hash_table_new(g_str_hash, g_str_equal);
 
   ros_handle = find_dissector("ros");
 
diff --git a/asn1/ros/packet-ros-template.h b/asn1/ros/packet-ros-template.h
index 11c7c6d702..08209cb9f6 100644
--- a/asn1/ros/packet-ros-template.h
+++ b/asn1/ros/packet-ros-template.h
@@ -36,17 +36,44 @@
 
 # define ROS_OP_MASK    0xff000000
 
+# define ROS_OP_PDU_MASK  0xf0000000
 # define ROS_OP_ARGUMENT  0x10000000
 # define ROS_OP_RESULT  0x20000000
 # define ROS_OP_ERROR   0x30000000
 # define ROS_OP_REJECT  0x40000000
 
+# define ROS_OP_TYPE_MASK 0x0f000000
 # define ROS_OP_BIND    0x01000000
 # define ROS_OP_UNBIND  0x02000000
 # define ROS_OP_INVOKE  0x03000000
 
 # define ROS_OP_OPCODE_MASK (~ROS_OP_MASK)
 
+# define op_ros_bind   (-1) /* pseudo operation code for asn2wrs generated binds */
+# define err_ros_bind  (-1) /* pseudo eror code for asn2wrs generated binds */
+
+typedef struct _ros_opr_t {
+  gint32 opcode;
+  new_dissector_t arg_pdu;
+  new_dissector_t res_pdu;
+} ros_opr_t;
+
+typedef struct _ros_err_t {
+  gint32 errcode;
+  new_dissector_t err_pdu;
+} ros_err_t;
+
+typedef struct _ros_info_t {
+  const gchar         *name;
+  int                 *proto;
+  gint                *ett_proto;
+  const value_string  *opr_code_strings;
+  const ros_opr_t     *opr_code_dissectors;
+  const value_string  *err_code_strings;
+  const ros_err_t     *err_code_dissectors;
+} ros_info_t;
+
 void register_ros_oid_dissector_handle(const char *oid, dissector_handle_t dissector, int proto _U_, const char *name, gboolean uses_rtse);
+void register_ros_protocol_info(const char *oid, const ros_info_t *rinfo, int proto _U_, const char *name, gboolean uses_rtse);
 
 #endif  /* PACKET_ROS_H */
diff --git a/asn1/ros/ros.cnf b/asn1/ros/ros.cnf
index 6ab6c0e50f..813f79da23 100644
--- a/asn1/ros/ros.cnf
+++ b/asn1/ros/ros.cnf
@@ -61,7 +61,7 @@ Reject/problem/returnResult	rejectResult
   if(session && session->pres_ctx_id && (oid = find_oid_by_pres_ctx_id(actx->pinfo, session->pres_ctx_id))) {
 	/* this should be ROS! */
 	session->ros_op = (ROS_OP_INVOKE | ROS_OP_ERROR);
-	/* now add the opcode  (really the errode) */
+	/* now add the opcode  (really the error code) */
 	session->ros_op |= opcode;
 	offset = call_ros_oid_callback(oid, tvb, offset, actx->pinfo, top_tree);
   }