Network Service Header Dissector for Ethernet & GRE encapsulation

draft-ietf-sfc-nsh-01.txt

Bug: 11490
Change-Id: I95adb1e0b1e42ba8c75e82145a756e2836a9a989
Reviewed-on: https://code.wireshark.org/review/13633
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

6 files changed, 390 insertions, 0 deletions

diff --git a/AUTHORS b/AUTHORS
index 6c72645fb2..617d5dc3c3 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -3924,6 +3924,7 @@ Robert Jongbloed	<robertj[AT]voxlucida.com.au>
 Pavel Moravec		<pmoravec[AT]redhat.com>
 Robert Long		<rlong[AT]sandia.gov>
 James Lynch		<lynch007[AT]gmail.com>
+Chidambaram Arunachalam		<carunach[AT]cisco.com>
 
 Dan Lasley <dlasley[AT]promus.com> gave permission for his
 dumpit() hex-dump routine to be used.
diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index e53db404f8..407313003b 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -1077,6 +1077,7 @@ set(DISSECTOR_SRC
 	dissectors/packet-nntp.c
 	dissectors/packet-noe.c
 	dissectors/packet-nsip.c
+	dissectors/packet-nsh.c
 	dissectors/packet-nsrp.c
 	dissectors/packet-nstrace.c
 	dissectors/packet-nt-oui.c
diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index abac28b253..88faa07f13 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -996,6 +996,7 @@ DISSECTOR_SRC = \
 	packet-nntp.c		\
 	packet-noe.c		\
 	packet-nsip.c		\
+	packet-nsh.c		\
 	packet-nsrp.c		\
 	packet-nstrace.c	\
 	packet-nt-oui.c		\
diff --git a/epan/dissectors/packet-gre.c b/epan/dissectors/packet-gre.c
index 03de868d18..6c44314627 100644
--- a/epan/dissectors/packet-gre.c
+++ b/epan/dissectors/packet-gre.c
@@ -133,6 +133,7 @@ const value_string gre_typevals[] = {
     { ETHERTYPE_RAW_FR,    "Frame Relay"},
     { ETHERTYPE_IPv6,      "IPv6" },
     { ETHERTYPE_MPLS,      "MPLS label switched packet" },
+    { ETHERTYPE_NSH,       "Network Service Header" },
     { ETHERTYPE_CDMA2000_A10_UBS,"CDMA2000 A10 Unstructured byte stream" },
     { ETHERTYPE_3GPP2,     "CDMA2000 A10 3GPP2 Packet" },
     { GRE_ARUBA_8200,      "ARUBA WLAN" },
diff --git a/epan/dissectors/packet-nsh.c b/epan/dissectors/packet-nsh.c
new file mode 100644
index 0000000000..16ba3761f7
--- /dev/null
+++ b/epan/dissectors/packet-nsh.c
@@ -0,0 +1,382 @@
+/*Routines for Network Service Header
+ *draft-ietf-sfc-nsh-01
+ *Author: Chidambaram Arunachalam <carunach@cisco.com>
+ *Copyright 2016, ciscoSystems Inc.
+ *
+ *
+ *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.
+ */
+
+#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>
+
+#define MD_TYPE_1 1
+#define MD_TYPE_2 2
+
+/* Prototypes */
+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_EXPERIMENTAL
+};
+
+static const value_string nsh_next_protocols[] = {
+	{ NSH_IPV4, "IPv4" },
+	{ NSH_IPV6, "IPv6" },
+	{ NSH_ETHERNET, "Ethernet" },
+	{ NSH_EXPERIMENTAL, "Experimental" },
+	{ 0, NULL }
+};
+
+
+static int proto_nsh = -1;
+static int hf_nsh_version = -1;
+static int hf_nsh_oam = -1;
+static int hf_nsh_critical_metadata = -1;
+static int hf_nsh_reservedbits = -1;
+static int hf_nsh_length = -1;
+static int hf_nsh_md_type = -1;
+static int hf_nsh_next_proto = -1;
+static int hf_nsh_service_pathID = -1;
+static int hf_nsh_service_index = -1;
+static int hf_nsh_context_header = -1;
+static int hf_nsh_metadata_class = -1;
+static int hf_nsh_metadata_type = -1;
+static int hf_nsh_metadata_reservedbits = -1;
+static int hf_nsh_metadata_length = -1;
+static int hf_nsh_metadata = -1;
+
+static gint ett_nsh = -1;
+static dissector_handle_t dissector_ipv6;
+static dissector_handle_t dissector_ip;
+static dissector_handle_t dissector_eth;
+
+/*
+ *Dissect Fixed Length Context headers
+ *
+ */
+static void
+dissect_nsh_md_type_1(tvbuff_t *tvb, proto_tree *nsh_tree, int offset)
+{
+
+	proto_tree_add_item(nsh_tree, hf_nsh_context_header, tvb, offset, 4, ENC_NA);
+	proto_tree_add_item(nsh_tree, hf_nsh_context_header, tvb, offset + 4, 4, ENC_NA);
+	proto_tree_add_item(nsh_tree, hf_nsh_context_header, tvb, offset + 8, 4, ENC_NA);
+	proto_tree_add_item(nsh_tree, hf_nsh_context_header, tvb, offset + 12, 4, ENC_NA);
+
+
+}
+
+/*
+ *Dissect Variable Length Context headers
+ *
+ */
+
+static void
+dissect_nsh_md_type_2(tvbuff_t *tvb, proto_tree *nsh_tree, int offset, int nsh_bytes_len)
+{
+
+	int type2_metadata_len = 0;
+
+	while (offset < nsh_bytes_len) {
+
+		proto_tree_add_item(nsh_tree, hf_nsh_metadata_class, tvb, offset, 2, ENC_BIG_ENDIAN);
+		proto_tree_add_item(nsh_tree, hf_nsh_metadata_type, tvb, offset + 2, 1, ENC_BIG_ENDIAN);
+
+		/* Bits 24 - 26 are reserved */
+		proto_tree_add_item(nsh_tree, hf_nsh_metadata_reservedbits, tvb, offset + 3, 1, ENC_BIG_ENDIAN);
+
+		/*Bits 27-31 represent length in 4 bytes words*/
+		proto_tree_add_item(nsh_tree, hf_nsh_metadata_length, tvb, offset + 3, 1, ENC_BIG_ENDIAN);
+		type2_metadata_len = 4 * tvb_get_bits8(tvb, ((offset + 3) * 8) + 3, 5);
+
+		if (type2_metadata_len >= 4)
+			proto_tree_add_item(nsh_tree, hf_nsh_metadata, tvb, offset + 4, type2_metadata_len, ENC_NA);
+
+		offset = offset + 4 + type2_metadata_len;
+
+	}
+
+
+}
+
+
+/*
+ *Dissect Network Service Header
+ *
+ */
+
+static int
+dissect_nsh(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+
+	int offset = 0;
+	int md_type = -1;
+	int nsh_bytes_len = 0;
+	int nsh_next_proto = -1;
+	int captured_length;
+	tvbuff_t *next_tvb;
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "NSH");
+	col_set_str(pinfo->cinfo, COL_INFO, "Network Service Header");
+
+	captured_length = tvb_captured_length(tvb);
+
+
+	if (tree) {
+		proto_item *ti;
+		proto_tree *nsh_tree;
+
+		/* Bits 10 - 15 contain length value */
+		nsh_bytes_len = 4 * tvb_get_bits8(tvb, 10, 6);
+
+		ti = proto_tree_add_item(tree, proto_nsh, tvb, offset, nsh_bytes_len, ENC_NA);
+		nsh_tree = proto_item_add_subtree(ti, ett_nsh);
+
+		/*NSH Base Header*/
+
+		proto_tree_add_item(nsh_tree, hf_nsh_version, tvb, offset, 1, ENC_BIG_ENDIAN);
+		proto_tree_add_item(nsh_tree, hf_nsh_oam, tvb, offset, 1, ENC_BIG_ENDIAN);
+		proto_tree_add_item(nsh_tree, hf_nsh_critical_metadata, tvb, offset, 1, ENC_BIG_ENDIAN);
+
+
+		/* Bits 4 - 9 are reserved */
+		proto_tree_add_item(nsh_tree, hf_nsh_reservedbits, tvb, offset, 2, ENC_BIG_ENDIAN);
+		proto_tree_add_item(nsh_tree, hf_nsh_length, tvb, offset + 1, 1, ENC_BIG_ENDIAN);
+
+
+		md_type = tvb_get_guint8(tvb, offset + 2);
+		proto_tree_add_item(nsh_tree, hf_nsh_md_type, tvb, offset + 2, 1, ENC_BIG_ENDIAN);
+
+		nsh_next_proto = tvb_get_guint8(tvb, offset + 3);
+		proto_tree_add_item(nsh_tree, hf_nsh_next_proto, tvb, offset + 3, 1, ENC_BIG_ENDIAN);
+
+		/*NSH Service Path Header */
+		offset = offset + 4;
+		proto_tree_add_item(nsh_tree, hf_nsh_service_pathID, tvb, offset, 3, ENC_BIG_ENDIAN);
+		proto_tree_add_item(nsh_tree, hf_nsh_service_index, tvb, offset + 3, 1, ENC_BIG_ENDIAN);
+
+		/* Decode Context Headers */
+		offset = offset + 4;
+		switch (md_type) {
+
+		case MD_TYPE_1:
+			dissect_nsh_md_type_1(tvb, nsh_tree, offset);
+			break;
+
+		case MD_TYPE_2:
+
+			/* MD Type 2 indicates ZERO or more Variable Length Context headers*/
+			if (nsh_bytes_len > 8)
+				dissect_nsh_md_type_2(tvb, nsh_tree, offset, nsh_bytes_len);
+			break;
+
+		}
+
+		/*Decode next protocol payload */
+
+		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;
+
+			}
+		}
+	}
+
+	return tvb_captured_length(tvb);
+
+}
+
+void
+proto_register_nsh(void)
+{
+	static hf_register_info nsh_info[] = {
+
+		/* Network Service Header fields */
+		{ &hf_nsh_version,
+		{ "Version", "nsh.version",
+		FT_UINT16, BASE_DEC_HEX, NULL, 0xC000,
+		NULL, HFILL }
+		},
+
+		{ &hf_nsh_oam,
+		{ "O Bit", "nsh.Obit",
+		FT_UINT16, BASE_DEC, NULL, 0x2000,
+		"OAM Bit", HFILL }
+		},
+
+
+		{ &hf_nsh_critical_metadata,
+		{ "C Bit", "nsh.CBit",
+		FT_UINT16, BASE_DEC, NULL, 0x1000,
+		"Critical Metadata Bit", HFILL }
+		},
+
+
+		{ &hf_nsh_reservedbits,
+		{ "Reserved Bits", "nsh.reservedbits",
+		FT_UINT16, BASE_HEX, NULL, 0x0FC0,
+		"Reserved bits within NSH Base Header", HFILL }
+		},
+
+
+		{ &hf_nsh_length,
+		{ "Length", "nsh.length",
+		FT_UINT16, BASE_DEC_HEX, NULL, 0x003F,
+		"Total length, in 4-byte words, of NSH including Base, Service Path headers and optional variable TLVs", HFILL }
+		},
+
+
+		{ &hf_nsh_md_type,
+		{ "MD Type", "nsh.mdtype",
+		FT_UINT8, BASE_DEC_HEX, NULL, 0x00,
+		"Metadata Type defines the format of the metadata being carried", HFILL }
+		},
+
+
+		{ &hf_nsh_next_proto,
+		{ "Next Protocol", "nsh.nextproto",
+		FT_UINT8, BASE_DEC_HEX, VALS(nsh_next_protocols), 0x00,
+		"Protocol type of the original packet", HFILL }
+		},
+
+
+		{ &hf_nsh_service_pathID,
+		{ "SPI", "nsh.spi",
+		FT_UINT24, BASE_DEC_HEX, NULL, 0x00,
+		"Service Path Identifier", HFILL }
+		},
+
+
+		{ &hf_nsh_service_index,
+		{ "SI", "nsh.si",
+		FT_UINT8, BASE_DEC_HEX, NULL, 0x00,
+		"Service Index", HFILL }
+		},
+
+
+
+		{ &hf_nsh_context_header,
+		{ "Context Header", "nsh.contextheader",
+		FT_BYTES, BASE_NONE, NULL, 0x00,
+		"Manadatory Context Header", HFILL }
+		},
+
+
+		{ &hf_nsh_metadata_class,
+		{ "TLV Class", "nsh.metadataclass",
+		FT_UINT16, BASE_DEC_HEX, NULL, 0x00,
+		"TLV class describes the scope of the metadata type field", HFILL }
+		},
+
+
+		{ &hf_nsh_metadata_type,
+		{ "Type", "nsh.metadatatype",
+		FT_UINT8, BASE_DEC_HEX, NULL, 0x00,
+		"Type of metadata", HFILL }
+		},
+
+
+		{ &hf_nsh_metadata_reservedbits,
+		{ "Reserved Bits", "nsh.metadatareservedbits",
+		FT_UINT8, BASE_HEX, NULL, 0xE0,
+		"Reserved Bits within Variable Length Metadata header", HFILL }
+		},
+
+
+		{ &hf_nsh_metadata_length,
+		{ "Length", "nsh.metadatalen",
+		FT_UINT8, BASE_HEX, NULL, 0x1F,
+		"Length of the variable metadata in 4-byte words", HFILL }
+		},
+
+
+		{ &hf_nsh_metadata,
+		{ "Variable Metadata", "nsh.metadata",
+		FT_BYTES, BASE_NONE, NULL, 0x00,
+		"Variable length metadata", HFILL }
+		},
+
+	};
+
+
+	static gint *ett[] = {
+		&ett_nsh,
+	};
+
+	proto_nsh = proto_register_protocol("Network Service Header",
+		"NSH", "nsh");
+	proto_register_field_array(proto_nsh, nsh_info, array_length(nsh_info));
+	proto_register_subtree_array(ett, array_length(ett));
+
+}
+
+void
+proto_reg_handoff_nsh(void)
+{
+
+	dissector_handle_t nsh_handle;
+
+	nsh_handle = create_dissector_handle(dissect_nsh, proto_nsh);
+	dissector_add_uint("gre.proto", ETHERTYPE_NSH, nsh_handle);
+
+	dissector_ip = find_dissector("ip");
+	dissector_ipv6 = find_dissector("ipv6");
+	dissector_eth = find_dissector("eth");
+
+
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */
diff --git a/epan/etypes.h b/epan/etypes.h
index 5af30e5101..1e0b2694a1 100644
--- a/epan/etypes.h
+++ b/epan/etypes.h
@@ -538,6 +538,10 @@ extern "C" {
 #define ETHERTYPE_HSR			0x892F  /* High-availability Seamless Redundancy (IEC62439 Part 3) */
 #endif
 
+#ifndef ETHERTYPE_NSH
+#define ETHERTYPE_NSH			0x894F  /* Network Service Header (draft-ietf-sfc-nsh-01.txt) */
+#endif
+
 #ifndef ETHERTYPE_LOOP
 #define ETHERTYPE_LOOP			0x9000	/* used for layer 2 testing (do i see my own frames on the wire) */
 #endif