Export "igmp_checksum()" from the IGMP dissector and give it additional

arguments that specify the header field indices for the checksum field
and the "checksum is bad" Boolean, and have the dissectors for some
protocols that use IGMP (DVMRP, MRDISC, MSNIP) use it rather than having
their own checksumming routines.

Also, fix it to correctly add the "checksum is bad" Boolean.


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@4665 f5534014-38df-0310-8fa8-9805f1628bb7

6 files changed, 62 insertions, 98 deletions

diff --git a/Makefile.am b/Makefile.am
index e6ece7d512..4773a7304e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for Ethereal
 #
-# $Id: Makefile.am,v 1.409 2002/01/31 07:51:32 girlich Exp $
+# $Id: Makefile.am,v 1.410 2002/02/01 11:01:56 guy Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@ethereal.com>
@@ -371,6 +371,7 @@ noinst_HEADERS = \
 	packet-http.h  \
 	packet-ieee80211.h \
 	packet-ieee8023.h \
+	packet-igmp.h  \
 	packet-ip.h    \
 	packet-ipsec.h \
 	packet-ipv6.h  \
diff --git a/packet-dvmrp.c b/packet-dvmrp.c
index c8624226fa..f879cfeb5e 100644
--- a/packet-dvmrp.c
+++ b/packet-dvmrp.c
@@ -1,7 +1,7 @@
 /* packet-dvmrp.c   2001 Ronnie Sahlberg <See AUTHORS for email>
  * Routines for IGMP/DVMRP packet disassembly
  *
- * $Id: packet-dvmrp.c,v 1.7 2002/01/21 07:36:34 guy Exp $
+ * $Id: packet-dvmrp.c,v 1.8 2002/02/01 11:01:56 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -65,7 +65,7 @@
 
 #include <epan/packet.h>
 #include "ipproto.h"
-#include "in_cksum.h"
+#include "packet-igmp.h"
 #include "packet-dvmrp.h"
 
 static int proto_dvmrp = -1;
@@ -214,29 +214,6 @@ static const true_false_string tfs_cap_netmask = {
 	"NOT Netmask capable"
 };
 
-static void dvmrp_checksum(proto_tree *tree,tvbuff_t *tvb, int len)
-{
-	guint16 cksum,hdrcksum;
-	vec_t cksum_vec[1];
-
-	cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, len);
-	cksum_vec[0].len = len;
-
-	hdrcksum = tvb_get_ntohs(tvb, 2);
-	cksum = in_cksum(&cksum_vec[0],1);
-
-	if (cksum==0) {
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (correct)", hdrcksum);
-	} else {
-		proto_tree_add_item_hidden(tree, hf_checksum_bad, tvb, 2, 2, TRUE);
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
-	}
-
-	return;
-}
-
-
-
 int
 dissect_v3_report(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 {
@@ -345,7 +322,7 @@ dissect_dvmrp_v3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int
 	}
 
 	/* checksum */
-	dvmrp_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* skip unused byte */
@@ -475,7 +452,7 @@ dissect_dvmrp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int
 	}
 
 	/* checksum */
-	dvmrp_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* decode all the v1 commands */
@@ -812,4 +789,3 @@ proto_register_dvmrp(void)
 	proto_register_field_array(proto_dvmrp, hf, array_length(hf));
 	proto_register_subtree_array(ett, array_length(ett));
 }
-
diff --git a/packet-igmp.c b/packet-igmp.c
index 8aee8a400e..649ae6e50e 100644
--- a/packet-igmp.c
+++ b/packet-igmp.c
@@ -1,7 +1,7 @@
 /* packet-igmp.c   2001 Ronnie Sahlberg <See AUTHORS for email>
  * Routines for IGMP packet disassembly
  *
- * $Id: packet-igmp.c,v 1.17 2002/01/21 07:36:35 guy Exp $
+ * $Id: packet-igmp.c,v 1.18 2002/02/01 11:01:57 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -309,8 +309,8 @@ static const value_string mtrace_fwd_code_vals[] = {
 	proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);	\
 	offset += 1;
 
-static void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
-    guint len)
+void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, int hf_index,
+    int hf_index_bad, packet_info *pinfo, guint len)
 {
 	guint16 cksum, hdrcksum;
 	vec_t cksum_vec[1];
@@ -321,7 +321,7 @@ static void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
 		 */
 		len = tvb_reported_length(tvb);
 	}
-	
+
 	hdrcksum = tvb_get_ntohs(tvb, 2);
 	if (!pinfo->fragmented && tvb_length(tvb) >= len) {
 		/*
@@ -334,18 +334,18 @@ static void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
 		cksum = in_cksum(&cksum_vec[0],1);
 
 		if (cksum == 0) {
-			proto_tree_add_uint_format(tree, hf_checksum,
+			proto_tree_add_uint_format(tree, hf_index,
 			    tvb, 2, 2, hdrcksum,
 			    "Header checksum: 0x%04x (correct)", hdrcksum);
 		} else {
-			proto_tree_add_item_hidden(tree, hf_checksum_bad,
+			proto_tree_add_boolean_hidden(tree, hf_index_bad,
 			    tvb, 2, 2, TRUE);
-			proto_tree_add_uint_format(tree, hf_checksum,
+			proto_tree_add_uint_format(tree, hf_index,
 			    tvb, 2, 2, hdrcksum,
 			    "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
 		}
 	} else
-		proto_tree_add_uint(tree, hf_checksum, tvb, 2, 2, hdrcksum);
+		proto_tree_add_uint(tree, hf_index, tvb, 2, 2, hdrcksum);
 
 	return;
 }
@@ -500,8 +500,8 @@ dissect_igmp_v3_response(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, in
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 0);
-	offset +=2;
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
+	offset += 2;
 
 	/* skip reserved field */
 	offset += 2;
@@ -530,7 +530,7 @@ dissect_igmp_v3_query(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int t
 	offset = dissect_v3_max_resp(tvb, pinfo, tree, offset);
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 0);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* group address */
@@ -571,7 +571,7 @@ dissect_igmp_v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, i
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 8);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
 	offset += 2;
 
 	/* group address */
@@ -591,7 +591,7 @@ dissect_igmp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, i
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 8);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
 	offset += 2;
 
 	/* group address */
@@ -623,7 +623,7 @@ dissect_igmp_v0(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, i
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 20);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 20);
 	offset += 2;
 
 	/* identifier */
@@ -680,7 +680,7 @@ dissect_igmp_mtrace(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int typ
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, pinfo, 0);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* group address to be traced */
diff --git a/packet-igmp.h b/packet-igmp.h
new file mode 100644
index 0000000000..abb363c78b
--- /dev/null
+++ b/packet-igmp.h
@@ -0,0 +1,32 @@
+/* packet-igmp.h   2001 Ronnie Sahlberg <See AUTHORS for email>
+ * Declarations of routines for IGMP packet disassembly
+ *
+ * $Id: packet-igmp.h,v 1.1 2002/02/01 11:01:57 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __PACKET_MSNIP_H__
+#define __PACKET_MSNIP_H__
+
+void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, int hf_index,
+    int hf_index_bad, packet_info *pinfo, guint len);
+
+#endif
+
diff --git a/packet-mrdisc.c b/packet-mrdisc.c
index 724a5a4732..e5a42e3be4 100644
--- a/packet-mrdisc.c
+++ b/packet-mrdisc.c
@@ -1,7 +1,7 @@
 /* packet-mrdisc.c   2001 Ronnie Sahlberg <See AUTHORS for email>
  * Routines for IGMP/MRDISC packet disassembly
  *
- * $Id: packet-mrdisc.c,v 1.6 2002/01/21 07:36:37 guy Exp $
+ * $Id: packet-mrdisc.c,v 1.7 2002/02/01 11:01:57 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -49,7 +49,7 @@
 #include <glib.h>
 
 #include <epan/packet.h>
-#include "in_cksum.h"
+#include "packet-igmp.h"
 #include "packet-mrdisc.h"
 
 
@@ -88,28 +88,6 @@ static const value_string mrdisc_options[] = {
 };
 
 
-static void mrdisc_checksum(proto_tree *tree,tvbuff_t *tvb, int len)
-{
-	guint16 cksum,hdrcksum;
-	vec_t cksum_vec[1];
-
-	cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, len);
-	cksum_vec[0].len = len;
-
-	hdrcksum = tvb_get_ntohs(tvb, 2);
-	cksum = in_cksum(&cksum_vec[0],1);
-
-	if (cksum==0) {
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (correct)", hdrcksum);
-	} else {
-		proto_tree_add_item_hidden(tree, hf_checksum_bad, tvb, 2, 2, TRUE);
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
-	}
-
-	return;
-}
-
-
 static int
 dissect_mrdisc_mra(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 {
@@ -120,7 +98,7 @@ dissect_mrdisc_mra(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, i
 	offset += 1;
 
 	/* checksum */
-	mrdisc_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* skip unused bytes */
@@ -199,7 +177,7 @@ dissect_mrdisc_mrst(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
 	offset += 1;
 
 	/* checksum */
-	mrdisc_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	return offset;
diff --git a/packet-msnip.c b/packet-msnip.c
index c4eacfa56d..4d2862eafc 100644
--- a/packet-msnip.c
+++ b/packet-msnip.c
@@ -1,7 +1,7 @@
 /* packet-msnip.c   2001 Ronnie Sahlberg <See AUTHORS for email>
  * Routines for IGMP/MSNIP packet disassembly
  *
- * $Id: packet-msnip.c,v 1.5 2002/01/21 07:36:37 guy Exp $
+ * $Id: packet-msnip.c,v 1.6 2002/02/01 11:01:57 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -48,7 +48,7 @@
 #include <glib.h>
 
 #include <epan/packet.h>
-#include "in_cksum.h"
+#include "packet-igmp.h"
 #include "packet-msnip.h"
 
 
@@ -87,29 +87,6 @@ static const value_string msnip_rec_types[] = {
 	{0,					NULL}
 };
 
-static void 
-msnip_checksum(proto_tree *tree,tvbuff_t *tvb, int len)
-{
-	guint16 cksum,hdrcksum;
-	vec_t cksum_vec[1];
-
-	cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, len);
-	cksum_vec[0].len = len;
-
-	hdrcksum = tvb_get_ntohs(tvb, 2);
-	cksum = in_cksum(&cksum_vec[0],1);
-
-	if (cksum==0) {
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (correct)", hdrcksum);
-	} else {
-		proto_tree_add_item_hidden(tree, hf_checksum_bad, tvb, 2, 2, TRUE);
-		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
-	}
-
-	return;
-}
-
-
 static int
 dissect_msnip_rmr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 {
@@ -121,7 +98,7 @@ dissect_msnip_rmr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, in
 	offset += 1;
 
 	/* checksum */
-	msnip_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	while (count--) {
@@ -170,7 +147,7 @@ dissect_msnip_is(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int
 	offset += 1;
 
 	/* checksum */
-	msnip_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* 16 bit holdtime */
@@ -196,7 +173,7 @@ dissect_msnip_gm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int
 	offset += 1;
 
 	/* checksum */
-	msnip_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 	offset += 2;
 
 	/* holdtime */