From: jake <jake@f5534014-38df-0310-8fa8-9805f1628bb7>
Date: Fri, 2 Oct 2009 07:01:20 +0000 (+0000)
Subject: From Francesco Fondelli:
X-Git-Url: http://git.samba.org/samba.git/?p=obnox%2Fwireshark%2Fwip.git;a=commitdiff_plain;h=0eddb421b7e6c7392687608e8eeb0a45f52d9eff

From Francesco Fondelli:
Back in August 2002 the check-sum field was removed from the
LMP specification (draft-ietf-ccamp-lmp-05).  This patch aligns
packet-lmp.c dissector with RFC 4204.


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@30244 f5534014-38df-0310-8fa8-9805f1628bb7
---

diff --git a/AUTHORS b/AUTHORS
index fe3fdf7327..c0065d670b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -2319,6 +2319,7 @@ Francesco Fondelli	<francesco.fondelli [AT] gmail.com> {
 	enhanced "what's past last MPLS label?" heuristic
 	Ethernet PW (with/without CW) support, RFC 4448
 	ATM PW (with/without CW) support, RFC 4717
+	LMP, update to RFC 4204
 }
 
 Artem Tamazov           <artem.tamazov [AT] tellabs.com> {
diff --git a/epan/dissectors/packet-lmp.c b/epan/dissectors/packet-lmp.c
index 51d034cbf3..d7212dceee 100644
--- a/epan/dissectors/packet-lmp.c
+++ b/epan/dissectors/packet-lmp.c
@@ -72,6 +72,8 @@ static int proto_lmp = -1;
 static guint lmp_udp_port = UDP_PORT_LMP_DEFAULT;
 static guint lmp_udp_port_config = UDP_PORT_LMP_DEFAULT;
 
+static gboolean lmp_checksum_config = FALSE;
+
 static dissector_handle_t lmp_handle;
 
 /*----------------------------------------------------------------------
@@ -735,28 +737,32 @@ dissect_lmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 		return tvb_length(tvb);
 	}
 
-	cksum = tvb_get_ntohs(tvb, offset+6);
-	if (!pinfo->fragmented && (int) tvb_length(tvb) >= msg_length) {
-	    /* The packet isn't part of a fragmented datagram and isn't
-	       truncated, so we can checksum it. */
-	    cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, msg_length);
-	    cksum_vec[0].len = msg_length;
-	    computed_cksum = in_cksum(&cksum_vec[0], 1);
-
-	    if (computed_cksum == 0) {
-		proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
-				    "Message Checksum: 0x%04x [correct]",
-				    cksum);
-	    } else {
-		proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
-				    "Message Checksum: 0x%04x [incorrect, should be 0x%04x]",
-				    cksum,
-				    in_cksum_shouldbe(cksum, computed_cksum));
-	    }
+	if (lmp_checksum_config) {
+		cksum = tvb_get_ntohs(tvb, offset+6);
+		if (!pinfo->fragmented && (int) tvb_length(tvb) >= msg_length) {
+		    /* The packet isn't part of a fragmented datagram and isn't
+		       truncated, so we can checksum it. */
+		    cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, msg_length);
+		    cksum_vec[0].len = msg_length;
+		    computed_cksum = in_cksum(&cksum_vec[0], 1);
+
+		    if (computed_cksum == 0) {
+			proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
+					    "Message Checksum: 0x%04x [correct]",
+					    cksum);
+		    } else {
+			proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
+					    "Message Checksum: 0x%04x [incorrect, should be 0x%04x]",
+					    cksum,
+					    in_cksum_shouldbe(cksum, computed_cksum));
+		    }
+		} else {
+		    proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
+					"Message Checksum: 0x%04x",
+					cksum);
+		}
 	} else {
-	    proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2,
-				"Message Checksum: 0x%04x",
-				cksum);
+		proto_tree_add_text(lmp_header_tree, tvb, offset+6, 2, "No checksum");
 	}
 
 	offset += 8;
@@ -2032,6 +2038,9 @@ register_lmp_prefs (void)
     prefs_register_uint_preference(
 	lmp_module, "udp_port", "LMP UDP Port",
 	"UDP port number to use for LMP", 10, &lmp_udp_port_config);
+    prefs_register_bool_preference(
+	lmp_module, "checksum", "LMP checksum field",
+	"Whether LMP contains a checksum which can be checked", &lmp_checksum_config);
     prefs_register_obsolete_preference(
         lmp_module, "version");
 }