packet-nsh.c: Create dissector table for next protocol

Change-Id: Id8be2a37f99f4ac9d531a694273c7d5d3f843cc1
Reviewed-on: https://code.wireshark.org/review/21163
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>

7 files changed, 76 insertions, 71 deletions

diff --git a/epan/dissectors/Makefile.am b/epan/dissectors/Makefile.am
index 4e34fa0bef..b74e9c3789 100644
--- a/epan/dissectors/Makefile.am
+++ b/epan/dissectors/Makefile.am
@@ -1657,6 +1657,7 @@ DISSECTOR_INCLUDES = \
 	packet-nfs.h		\
 	packet-nisplus.h	\
 	packet-nlm.h		\
+	packet-nsh.h		\
 	packet-ntlmssp.h	\
 	packet-ntp.h		\
 	packet-nvme.h		\
diff --git a/epan/dissectors/packet-eth.c b/epan/dissectors/packet-eth.c
index 30cfc9f64c..83657bffd5 100644
--- a/epan/dissectors/packet-eth.c
+++ b/epan/dissectors/packet-eth.c
@@ -43,6 +43,7 @@
 #include "packet-sflow.h"
 #include "packet-l2tp.h"
 #include "packet-vxlan.h"
+#include "packet-nsh.h"
 #include <epan/crc32-tvb.h>
 #include <wiretap/erf.h>
 
@@ -1025,6 +1026,7 @@ proto_reg_handoff_eth(void)
   dissector_add_uint("l2tp.pw_type", L2TPv3_PROTOCOL_ETH, eth_withoutfcs_handle);
   dissector_add_uint("vxlan.next_proto", VXLAN_ETHERNET, eth_withoutfcs_handle);
   dissector_add_uint("sll.ltype", LINUX_SLL_P_ETHERNET, eth_withoutfcs_handle);
+  dissector_add_uint("nsh.next_proto", NSH_ETHERNET, eth_withoutfcs_handle);
 
   /*
    * This is to handle the output for the Cisco CMTS "cable intercept"
diff --git a/epan/dissectors/packet-ip.c b/epan/dissectors/packet-ip.c
index b50428e516..6841abe3b7 100644
--- a/epan/dissectors/packet-ip.c
+++ b/epan/dissectors/packet-ip.c
@@ -58,6 +58,7 @@
 #include "packet-l2tp.h"
 #include "packet-vxlan.h"
 #include "packet-mpls.h"
+#include "packet-nsh.h"
 
 #ifdef HAVE_GEOIP
 #include <GeoIP.h>
@@ -3062,6 +3063,7 @@ proto_reg_handoff_ip(void)
   dissector_add_uint("wtap_encap", WTAP_ENCAP_RAW_IP4, ip_handle);
   dissector_add_uint("enc", BSD_AF_INET, ip_handle);
   dissector_add_uint("vxlan.next_proto", VXLAN_IPV4, ip_handle);
+  dissector_add_uint("nsh.next_proto", NSH_IPV4, ip_handle);
 
   heur_dissector_add("tipc", dissect_ip_heur, "IP over TIPC", "ip_tipc", proto_ip, HEURISTIC_ENABLE);
 
diff --git a/epan/dissectors/packet-ipv6.c b/epan/dissectors/packet-ipv6.c
index 15e9de71e5..0ae0f711df 100644
--- a/epan/dissectors/packet-ipv6.c
+++ b/epan/dissectors/packet-ipv6.c
@@ -53,6 +53,7 @@
 #include "packet-sflow.h"
 #include "packet-vxlan.h"
 #include "packet-mpls.h"
+#include "packet-nsh.h"
 
 #ifdef HAVE_GEOIP_V6
 #include <GeoIP.h>
@@ -3555,6 +3556,7 @@ proto_reg_handoff_ipv6(void)
     dissector_add_uint("wtap_encap", WTAP_ENCAP_RAW_IP6, ipv6_handle);
     dissector_add_uint("enc", BSD_AF_INET6_BSD, ipv6_handle);
     dissector_add_uint("vxlan.next_proto", VXLAN_IPV6, ipv6_handle);
+    dissector_add_uint("nsh.next_proto", NSH_IPV6, ipv6_handle);
 
     dissector_add_for_decode_as_with_preference("udp.port", ipv6_handle);
 
diff --git a/epan/dissectors/packet-mpls.c b/epan/dissectors/packet-mpls.c
index 4ea63e589e..bfe167fa0e 100644
--- a/epan/dissectors/packet-mpls.c
+++ b/epan/dissectors/packet-mpls.c
@@ -68,6 +68,7 @@
 #include "packet-sflow.h"
 #include "packet-l2tp.h"
 #include "packet-vxlan.h"
+#include "packet-nsh.h"
 
 void proto_register_mpls(void);
 void proto_reg_handoff_mpls(void);
@@ -687,6 +688,7 @@ proto_reg_handoff_mpls(void)
     dissector_add_uint("l2tp.pw_type", L2TPv3_PROTOCOL_MPLS, mpls_handle);
     dissector_add_uint_with_preference("udp.port", UDP_PORT_MPLS_OVER_UDP, mpls_handle);
     dissector_add_uint("vxlan.next_proto", VXLAN_MPLS, mpls_handle);
+    dissector_add_uint("nsh.next_proto", NSH_MPLS, mpls_handle);
 
     dissector_add_uint( "mpls.label", MPLS_LABEL_INVALID, mpls_pwcw_handle );
 
diff --git a/epan/dissectors/packet-nsh.c b/epan/dissectors/packet-nsh.c
index 6be15fc7c1..801915876e 100644
--- a/epan/dissectors/packet-nsh.c
+++ b/epan/dissectors/packet-nsh.c
@@ -1,39 +1,35 @@
-/*Routines for Network Service Header
- *draft-ietf-sfc-nsh-01
- *Author: Chidambaram Arunachalam <carunach@cisco.com>
- *Copyright 2016, ciscoSystems Inc.
+/* packet-nsh.c
+ * Routines for Network Service Header
+ * draft-ietf-sfc-nsh-01
+ * Author: Chidambaram Arunachalam <carunach@cisco.com>
+ * Copyright 2016, ciscoSystems Inc.
  *
+ * (c) Copyright 2016, Sumit Kumar Jha <sjha3@ncsu.edu>
+ * Support for VXLAN GPE encapsulation
  *
- *Wireshark - Network traffic analyzer
- *By Gerald Combs <gerald@wireshark.org>
- *Copyright 1998 Gerald Combs
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
  *
- *(c) Copyright 2016, Sumit Kumar Jha <sjha3@ncsu.edu>
- *Support for VXLAN GPE encapsulation
+ * 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 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.
  *
- *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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #include "config.h"
 #include <epan/packet.h>
-#include <epan/expert.h>
-#include <epan/ppptypes.h>
 #include <epan/etypes.h>
-#include <epan/prefs.h>
-#include <epan/ipproto.h>
-#include <epan/decode_as.h>
+#include "packet-nsh.h"
 #include "packet-vxlan.h"
 
 #define MD_TYPE_1 1
@@ -43,18 +39,6 @@
 void proto_reg_handoff_nsh(void);
 void proto_register_nsh(void);
 
-/*Network Service Header (NSH) Next Protocol field values */
-
-enum {
-	NSH_IPV4 = 1,
-	NSH_IPV6,
-	NSH_ETHERNET,
-	NSH_NSH,
-	NSH_MPLS,
-	NSH_EXPERIMENT_1 = 254,
-	NSH_EXPERIMENT_2,
-};
-
 static const value_string nsh_next_protocols[] = {
 	{ NSH_IPV4, "IPv4" },
 	{ NSH_IPV6, "IPv6" },
@@ -86,11 +70,7 @@ static int hf_nsh_metadata = -1;
 
 static gint ett_nsh = -1;
 
-static dissector_handle_t nsh_handle;
-static dissector_handle_t dissector_ipv6;
-static dissector_handle_t dissector_ip;
-static dissector_handle_t dissector_eth;
-static dissector_handle_t dissector_mpls;
+static dissector_table_t subdissector_table;
 
 /*
  *Dissect Fixed Length Context headers
@@ -219,28 +199,8 @@ dissect_nsh(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
 		if (captured_length > (nsh_bytes_len)) {
 
 			next_tvb = tvb_new_subset_remaining(tvb, nsh_bytes_len);
-			switch (nsh_next_proto) {
-
-			case NSH_IPV4:
-				call_dissector(dissector_ip, next_tvb, pinfo, tree);
-				break;
-
-			case NSH_IPV6:
-				call_dissector(dissector_ipv6, next_tvb, pinfo, tree);
-				break;
-
-			case NSH_ETHERNET:
-				call_dissector(dissector_eth, next_tvb, pinfo, tree);
-				break;
-
-			case NSH_NSH:
-				call_dissector(nsh_handle, next_tvb, pinfo, tree);
-				break;
-
-			case NSH_MPLS:
-				call_dissector(dissector_mpls, next_tvb, pinfo, tree);
-				break;
-
+			if (!dissector_try_uint(subdissector_table, nsh_next_proto, tvb, pinfo, tree)) {
+				call_data_dissector(next_tvb, pinfo, tree);
 			}
 		}
 	}
@@ -370,22 +330,20 @@ proto_register_nsh(void)
 	proto_register_field_array(proto_nsh, nsh_info, array_length(nsh_info));
 	proto_register_subtree_array(ett, array_length(ett));
 
+	subdissector_table = register_dissector_table("nsh.next_proto", "NSH Next Protocol", proto_nsh, FT_UINT32, BASE_DEC);
+
 }
 
 void
 proto_reg_handoff_nsh(void)
 {
+	static dissector_handle_t nsh_handle;
 
 	nsh_handle = create_dissector_handle(dissect_nsh, proto_nsh);
 	dissector_add_uint("ethertype", ETHERTYPE_NSH, nsh_handle);
 	dissector_add_uint("gre.proto", ETHERTYPE_NSH, nsh_handle);
 	dissector_add_uint("vxlan.next_proto", VXLAN_NSH, nsh_handle);
-
-	dissector_ip = find_dissector_add_dependency("ip", proto_nsh);
-	dissector_ipv6 = find_dissector_add_dependency("ipv6", proto_nsh);
-	dissector_eth = find_dissector_add_dependency("eth_maybefcs", proto_nsh);
-	dissector_mpls = find_dissector_add_dependency("mpls", proto_nsh);
-
+	dissector_add_uint("nsh.next_proto", NSH_NSH, nsh_handle);
 
 }
 
diff --git a/epan/dissectors/packet-nsh.h b/epan/dissectors/packet-nsh.h
new file mode 100644
index 0000000000..5e44dfaff9
--- /dev/null
+++ b/epan/dissectors/packet-nsh.h
@@ -0,0 +1,38 @@
+/* packet-nsh.h
+ *
+ * Routines for Network Service Header
+ * draft-ietf-sfc-nsh-01
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __PACKET_NSH_H__
+#define __PACKET_NSH_H__
+
+/*Network Service Header (NSH) Next Protocol field values */
+
+#define NSH_IPV4            1
+#define NSH_IPV6            2
+#define NSH_ETHERNET        3
+#define NSH_NSH             4
+#define NSH_MPLS            5
+#define NSH_EXPERIMENT_1    254
+#define NSH_EXPERIMENT_2    255
+
+#endif /* __PACKET_NSH_H__ */