Revert

length check "heuristics" for FF dissector (UDP + TCP)

"Fix" WTP+WSP packets incorrectly dissected as Foundation FieldBus packets https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=4822

As it fails with
cc1: warnings being treated as errors
packet-ff.c: In function 'dissect_ff_tcp':
packet-ff.c:13061: warning: passing argument 7 of 'tcp_dissect_pdus' from incompatible pointer type

svn path=/trunk/; revision=44724

1 files changed, 27 insertions, 26 deletions

diff --git a/epan/dissectors/packet-ff.c b/epan/dissectors/packet-ff.c
index 7f2577359f..9805c961b7 100644
--- a/epan/dissectors/packet-ff.c
+++ b/epan/dissectors/packet-ff.c
@@ -12941,7 +12941,7 @@ dissect_ff_msg_hdr(tvbuff_t *tvb,
 
 
 
-static int
+static void
 dissect_ff(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
 	proto_tree *sub_tree	= NULL;
@@ -12956,19 +12956,14 @@ dissect_ff(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 
 	guint32 trailer_len = 0;
 
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "FF");
+
 	Options	= tvb_get_guint8(tvb, 1);
 	ProtocolAndType	= tvb_get_guint8(tvb, 2);
 	Service	= tvb_get_guint8(tvb, 3);
 	FDAAddress	= tvb_get_ntohl(tvb, 4);
 	length = tvb_get_ntohl(tvb, 8);
 
-	/* Make sure the length field is valid */
-	if ((length > (guint32)tvb_reported_length_remaining(tvb, 0)) ||
-		(length < 12))
-		return 0;
-
-	col_set_str(pinfo->cinfo, COL_PROTOCOL, "FF");
-
 	if(tree) {
 		ti = proto_tree_add_item(tree, proto_ff, tvb, offset, length, ENC_NA);
 		sub_tree = proto_item_add_subtree(ti, ett_ff);
@@ -13017,7 +13012,7 @@ dissect_ff(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 		/*offset += trailer_len;*/
 	}
 
-	return tvb_length(tvb);
+	return;
 }
 
 
@@ -13030,7 +13025,7 @@ get_ff_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
 
 
 
-static int
+static void
 dissect_ff_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
 /*
@@ -13049,30 +13044,36 @@ dissect_ff_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  *
  */
 
-	/* Make sure we at least have the header */
-	if (!tvb_bytes_exist(tvb, 0, 12))
-		return 0;
-
-	/* Make sure the Message Length at least includes the header size */
-	if (tvb_get_ntohl(tvb, 8) < 12)
-		return 0;
-
 	tcp_dissect_pdus(tvb, pinfo, tree, ff_desegment,
 		12, get_ff_pdu_len, dissect_ff);
 
-	return tvb_length(tvb);
+	return;
 }
 
 
 
-static int
+static void
 dissect_ff_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
-	/* Make sure at least the header is there */
-	if ((guint32)tvb_reported_length(tvb) < 12)
-		return 0;
+	conversation_t *conversation	= NULL;
+
+	if(pinfo->destport == UDP_PORT_FF_FMS) {
+		conversation =
+			find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst,
+				PT_UDP, pinfo->srcport, 0, NO_PORT_B);
+
+		if(!conversation ||
+			(conversation->dissector_handle != ff_udp_handle)) {
+
+			conversation =
+				conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst,
+					PT_UDP, pinfo->srcport, 0, NO_PORT2);
+
+			conversation_set_dissector(conversation, ff_udp_handle);
+		}
+	}
 
-	return dissect_ff(tvb, pinfo, tree);
+	dissect_ff(tvb, pinfo, tree);
 }
 
 
@@ -16808,8 +16809,8 @@ proto_reg_handoff_ff(void)
 	/*
 	 * 4.8. Using UDP and TCP
 	 */
-	ff_udp_handle = new_create_dissector_handle(dissect_ff_udp, proto_ff);
-	ff_tcp_handle = new_create_dissector_handle(dissect_ff_tcp, proto_ff);
+	ff_udp_handle = create_dissector_handle(dissect_ff_udp, proto_ff);
+	ff_tcp_handle = create_dissector_handle(dissect_ff_tcp, proto_ff);
 
 	/*
 	 * 4.8.4.2. Use