Add initial support for dissecting packets encapsulated in Netfilter LOG (DLT_NFLOG=239).

svn path=/trunk/; revision=41872

3 files changed, 350 insertions, 0 deletions

diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index a4873a4a75..17a432e2b9 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -878,6 +878,7 @@ set(DISSECTOR_SRC
 	dissectors/packet-netsync.c
 	dissectors/packet-nettl.c
 	dissectors/packet-newmail.c
+	dissectors/packet-nflog.c
 	dissectors/packet-nfs.c
 	dissectors/packet-nfsacl.c
 	dissectors/packet-nfsauth.c
diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 5756ed6b65..d8d0bca79d 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -797,6 +797,7 @@ DISSECTOR_SRC = \
 	packet-netsync.c	\
 	packet-nettl.c		\
 	packet-newmail.c	\
+	packet-nflog.c		\
 	packet-nfs.c		\
 	packet-nfsacl.c		\
 	packet-nfsauth.c	\
diff --git a/epan/dissectors/packet-nflog.c b/epan/dissectors/packet-nflog.c
new file mode 100644
index 0000000000..ef44143dc9
--- /dev/null
+++ b/epan/dissectors/packet-nflog.c
@@ -0,0 +1,348 @@
+/* packet-nflog.c
+ * Copyright 2011,2012 Jekub Zawadzki <darkjames-ws@darkjames.pl>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+#include <epan/aftypes.h>
+
+/* nfulnl_attr_type enum from <linux/netfilter/nfnetlink_log.h> */
+enum ws_nfulnl_attr_type {
+    WS_NFULA_UNSPEC,
+    WS_NFULA_PACKET_HDR,
+    WS_NFULA_MARK,         /* __u32 nfmark */
+    WS_NFULA_TIMESTAMP,        /* nfulnl_msg_packet_timestamp */
+    WS_NFULA_IFINDEX_INDEV,        /* __u32 ifindex */
+    WS_NFULA_IFINDEX_OUTDEV,       /* __u32 ifindex */
+    WS_NFULA_IFINDEX_PHYSINDEV,    /* __u32 ifindex */
+    WS_NFULA_IFINDEX_PHYSOUTDEV,   /* __u32 ifindex */
+    WS_NFULA_HWADDR,           /* nfulnl_msg_packet_hw */
+    WS_NFULA_PAYLOAD,          /* opaque data payload */
+    WS_NFULA_PREFIX,           /* string prefix */
+    WS_NFULA_UID,          /* user id of socket */
+    WS_NFULA_SEQ,          /* instance-local sequence number */
+    WS_NFULA_SEQ_GLOBAL,       /* global sequence number */
+    WS_NFULA_GID,          /* group id of socket */
+    WS_NFULA_HWTYPE,           /* hardware type */
+    WS_NFULA_HWHEADER,         /* hardware header */
+    WS_NFULA_HWLEN,            /* hardware header length */
+};
+
+#define BYTE_ORDER_AUTO 0
+#define BYTE_ORDER_BE 1
+#define BYTE_ORDER_LE 2
+
+static enum_val_t byte_order_types[] = {
+    { "Auto", "Auto", BYTE_ORDER_AUTO },
+    { "LE", "LE", BYTE_ORDER_BE },
+    { "BE", "BE", BYTE_ORDER_LE },
+    { NULL, NULL, 0 }
+};
+
+static gint nflog_byte_order = BYTE_ORDER_AUTO;
+
+static int proto_nflog = -1;
+
+static int ett_nflog = -1;
+static int ett_nflog_tlv = -1;
+
+static int hf_nflog_family = -1;
+static int hf_nflog_version = -1;
+static int hf_nflog_resid = -1;
+static int hf_nflog_encoding = -1;
+
+static int hf_nflog_tlv = -1;
+static int hf_nflog_tlv_length = -1;
+static int hf_nflog_tlv_type = -1;
+static int hf_nflog_tlv_prefix = -1;
+static int hf_nflog_tlv_uid = -1;
+static int hf_nflog_tlv_gid = -1;
+static int hf_nflog_tlv_unknown = -1;
+
+static dissector_handle_t ip_handle;
+static dissector_handle_t ip6_handle;
+static dissector_handle_t data_handle;
+
+static const value_string _linux_family_vals[] = {
+    { LINUX_AF_INET, "IP" },
+    { LINUX_AF_INET6, "IPv6" },
+    { 0, NULL }
+};
+
+static const value_string _encoding_vals[] = {
+	{ ENC_BIG_ENDIAN, "Big Endian" },
+	{ ENC_LITTLE_ENDIAN, "Little Endian" },
+	{ ENC_NA, "Unknown" },
+	{ 0, NULL }
+};
+
+static const value_string nflog_tlv_vals[] = {
+	{ WS_NFULA_UNSPEC, "NFULA_UNSPEC" },
+	{ WS_NFULA_PACKET_HDR, "NFULA_PACKET_HDR" },
+	{ WS_NFULA_MARK, "NFULA_MARK" },
+	{ WS_NFULA_TIMESTAMP, "NFULA_TIMESTAMP" },
+	{ WS_NFULA_IFINDEX_INDEV, "NFULA_IFINDEX_INDEV" },
+	{ WS_NFULA_IFINDEX_OUTDEV, "NFULA_IFINDEX_OUTDEV" },
+	{ WS_NFULA_IFINDEX_PHYSINDEV, "NFULA_IFINDEX_PHYSINDEV" },
+	{ WS_NFULA_IFINDEX_PHYSOUTDEV, "NFULA_IFINDEX_PHYSOUTDEV" },
+	{ WS_NFULA_HWADDR, "NFULA_HWADDR" },
+	{ WS_NFULA_PAYLOAD, "NFULA_PAYLOAD" },
+	{ WS_NFULA_PREFIX, "NFULA_PREFIX" },
+	{ WS_NFULA_UID, "NFULA_UID" },
+	{ WS_NFULA_SEQ, "NFULA_SEQ" },
+	{ WS_NFULA_SEQ_GLOBAL, "NFULA_SEQ_GLOBAL" },
+	{ WS_NFULA_GID, "NFULA_GID" },
+	{ WS_NFULA_HWTYPE, "NFULA_HWTYPE" },
+	{ WS_NFULA_HWHEADER, "NFULA_HWHEADER" },
+	{ WS_NFULA_HWLEN, "NFULA_HWLEN" },
+	{ 0, NULL }
+};
+
+static int
+nflog_tvb_test_order(tvbuff_t *tvb, int offset, guint16 (*val16_get)(tvbuff_t *, int))
+{
+	while (tvb_length_remaining(tvb, offset) > 4) {
+		guint16 tlv_len = val16_get(tvb, offset + 0);
+		guint16 tlv_type = (val16_get(tvb, offset + 2) & 0x7fff);
+
+		if (tlv_type >= 0x100)
+			break;
+
+		if (tlv_type)
+			return 1;
+
+		offset += ((tlv_len + 3) & ~3);	/* next TLV aligned to 4B */
+	}
+	return 0;
+}
+
+static int
+nflog_tvb_byte_order(tvbuff_t *tvb, int tlv_offset)
+{
+	switch (nflog_byte_order) {
+		case BYTE_ORDER_BE:
+			return ENC_BIG_ENDIAN;
+
+		case BYTE_ORDER_LE:
+			return ENC_LITTLE_ENDIAN;
+	}
+
+	if (nflog_tvb_test_order(tvb, tlv_offset, tvb_get_ntohs))
+		return ENC_BIG_ENDIAN;
+
+	if (nflog_tvb_test_order(tvb, tlv_offset, tvb_get_letohs))
+		return ENC_LITTLE_ENDIAN;
+
+	return ENC_NA;
+}
+
+static void
+dissect_nflog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	const int start_tlv_offset = 4;
+
+	proto_tree *nflog_tree = NULL;
+	proto_item *ti;
+
+	int offset = 0;
+
+	tvbuff_t *next_tvb = NULL;
+	int aftype;
+
+	int enc;
+	guint16 (*val16_get)(tvbuff_t *, int);
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "NFLOG");
+	col_clear(pinfo->cinfo, COL_INFO);
+
+	aftype = tvb_get_guint8(tvb, 0);
+	enc = nflog_tvb_byte_order(tvb, start_tlv_offset);
+	switch (enc) {
+		case ENC_LITTLE_ENDIAN:
+			val16_get = tvb_get_letohs;
+			break;
+
+		case ENC_BIG_ENDIAN:
+		default:
+			val16_get = tvb_get_ntohs;
+			break;
+	}
+
+	/* Header */
+	if (proto_field_is_referenced(tree, proto_nflog)) {
+		ti = proto_tree_add_item(tree, proto_nflog, tvb, 0, -1, ENC_NA);
+		nflog_tree = proto_item_add_subtree(ti, ett_nflog);
+
+		proto_tree_add_item(nflog_tree, hf_nflog_family, tvb, offset, 1, ENC_NA);
+		offset += 1;
+
+		proto_tree_add_item(nflog_tree, hf_nflog_version, tvb, offset, 1, ENC_NA);
+		offset += 1;
+
+		proto_tree_add_item(nflog_tree, hf_nflog_resid, tvb, offset, 2, ENC_BIG_ENDIAN);
+		offset += 2;
+
+		ti = proto_tree_add_uint(nflog_tree, hf_nflog_encoding, tvb, offset, tvb_length_remaining(tvb, offset), enc);
+		PROTO_ITEM_SET_GENERATED(ti);
+	}
+
+	offset = start_tlv_offset;
+	/* TLVs */
+	while (tvb_length_remaining(tvb, offset) >= 4) {
+		guint16 tlv_len = val16_get(tvb, offset + 0);
+		guint16 tlv_type = (val16_get(tvb, offset + 2) & 0x7fff);
+		guint16 value_len = tlv_len - 4;
+
+		proto_tree *tlv_tree;
+
+		if (nflog_tree) {
+			ti = proto_tree_add_bytes_format(nflog_tree, hf_nflog_tlv, tvb, offset, tlv_len, NULL, "TLV Type: %s (%u), Length: %u", val_to_str_const(tlv_type, nflog_tlv_vals, "Unknown"), tlv_type, tlv_len);
+			tlv_tree = proto_item_add_subtree(ti, ett_nflog_tlv);
+
+			proto_tree_add_item(tlv_tree, hf_nflog_tlv_length, tvb, offset + 0, 2, enc);
+			proto_tree_add_item(tlv_tree, hf_nflog_tlv_type, tvb, offset + 2, 2, enc);
+			switch (tlv_type) {
+				case WS_NFULA_PAYLOAD:
+					break;
+				case WS_NFULA_PREFIX:
+					/* value_len >= 1 */
+					proto_tree_add_item(tlv_tree, hf_nflog_tlv_prefix, tvb, offset + 4, value_len, ENC_NA);
+					break;
+				case WS_NFULA_UID:
+					/* value_len == 4 */
+					proto_tree_add_item(tlv_tree, hf_nflog_tlv_uid, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);
+					break;
+				case WS_NFULA_GID:
+					/* value_len == 4 */
+					proto_tree_add_item(tlv_tree, hf_nflog_tlv_gid, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);
+					break;
+				/* ... */
+
+				default:
+					proto_tree_add_item(tlv_tree, hf_nflog_tlv_unknown, tvb, offset + 4, value_len, ENC_NA);
+			}
+		}
+
+		if (tlv_type == WS_NFULA_PAYLOAD)
+			next_tvb = tvb_new_subset(tvb, offset + 4, value_len, value_len);
+
+		offset += ((tlv_len + 3) & ~3);	/* next TLV aligned to 4B */
+	}
+
+	if (next_tvb) {
+		switch (aftype) {
+			case LINUX_AF_INET:
+				call_dissector(ip_handle, next_tvb, pinfo, tree);
+				break;
+			case LINUX_AF_INET6:
+				call_dissector(ip6_handle, next_tvb, pinfo, tree);
+				break;
+			default:
+				call_dissector(data_handle, next_tvb, pinfo, tree);
+				break;
+		}
+	}
+}
+
+void
+proto_register_nflog(void)
+{
+	static hf_register_info hf[] = {
+	/* Header */
+		{ &hf_nflog_family,
+			{ "Family", "nflog.family", FT_UINT8, BASE_DEC, VALS(_linux_family_vals), 0x00, NULL, HFILL }
+		},
+		{ &hf_nflog_version,
+			{ "Version", "nflog.version", FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL }
+		},
+		{ &hf_nflog_resid,
+			{ "Resource id", "nflog.res_id", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }
+		},
+
+		{ &hf_nflog_encoding,
+			{ "Encoding", "nflog.encoding", FT_UINT32, BASE_NONE, VALS(_encoding_vals), 0x00, NULL, HFILL }
+		},
+
+	/* TLV */
+		{ &hf_nflog_tlv,
+			{ "TLV", "nflog.tlv", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }
+		},
+		{ &hf_nflog_tlv_length,
+			{ "Length", "nflog.tlv_length", FT_UINT16, BASE_DEC, NULL, 0x00, "TLV Length", HFILL }
+		},
+		{ &hf_nflog_tlv_type,
+			{ "Type", "nflog.tlv_type", FT_UINT16, BASE_DEC, VALS(nflog_tlv_vals), 0x7fff, "TLV Type", HFILL }
+		},
+	/* TLV values */
+		{ &hf_nflog_tlv_prefix,
+			{ "Prefix", "nflog.prefix", FT_STRINGZ, BASE_NONE, NULL, 0x00, "TLV Prefix Value", HFILL }
+		},
+		{ &hf_nflog_tlv_uid,
+			{ "UID", "nflog.uid", FT_INT32, BASE_DEC, NULL, 0x00, "TLV UID Value", HFILL }
+		},
+		{ &hf_nflog_tlv_gid,
+			{ "GID", "nflog.gid", FT_INT32, BASE_DEC, NULL, 0x00, "TLV GID Value", HFILL }
+		},
+		{ &hf_nflog_tlv_unknown,
+			{ "Value", "nflog.tlv_value", FT_BYTES, BASE_NONE, NULL, 0x00, "TLV Value", HFILL }
+		},
+	};
+
+	static gint *ett[] = {
+		&ett_nflog,
+		&ett_nflog_tlv
+	};
+
+	module_t *pref;
+
+	proto_nflog = proto_register_protocol("Linux Netfilter LOG (NFLOG)", "NFLOG", "nflog");
+
+	pref = prefs_register_protocol(proto_nflog, NULL);
+	prefs_register_enum_preference(pref, "byte_order_type", "Byte Order", "Byte Order", &nflog_byte_order, byte_order_types, FALSE);
+
+	register_dissector("nflog", dissect_nflog, proto_nflog);
+
+	proto_register_field_array(proto_nflog, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+
+}
+
+void
+proto_reg_handoff_nflog(void)
+{
+	dissector_handle_t nflog_handle;
+
+	ip_handle   = find_dissector("ip");
+	ip6_handle  = find_dissector("ipv6");
+	data_handle = find_dissector("data");
+
+	nflog_handle = find_dissector("nflog");
+	dissector_add_uint("wtap_encap", WTAP_ENCAP_NFLOG, nflog_handle);
+}
+