DHCPv6 dissector, based on draft-ietf-dhc-dhcpv6-22.txt.

note that protocol constants are subject to change.
(packet format is also subject to change.  but 22 draft should go
to wg last call very soon, and I really hope it to be the final one...)

svn path=/trunk/; revision=4504

1 files changed, 268 insertions, 0 deletions

diff --git a/packet-dhcpv6.c b/packet-dhcpv6.c
new file mode 100644
index 0000000000..cbae66cde4
--- /dev/null
+++ b/packet-dhcpv6.c
@@ -0,0 +1,268 @@
+/* packet-dhpcv6.c
+ * Routines for DHCPv6 packet disassembly
+ * Jun-ichiro itojun Hagino <itojun@iijlab.net>
+ *
+ * $Id: packet-dhcpv6.c,v 1.1 2002/01/09 02:51:46 itojun Exp $
+ *
+ * The information used comes from:
+ * draft-ietf-dhc-dhcpv6-22.txt
+ * Note that protocol constants are still subject to change, based on IANA
+ * assignment decisions.
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+
+#include <string.h>
+#include <glib.h>
+#include "int-64bit.h"
+#include "packet.h"
+#include "ipv6-utils.h"
+
+static int proto_dhcpv6 = -1;
+static int hf_dhcpv6_msgtype = -1;
+
+static guint ett_dhcpv6 = -1;
+static guint ett_dhcpv6_option = -1;
+
+#define UDP_PORT_DHCPV6_DOWNSTREAM	546
+#define UDP_PORT_DHCPV6_UPSTREAM	547
+
+static const value_string msgtype_vals[] = {
+	{ 7,	"Reply" },
+	{ 11,	"Information request" },
+	{ 0,	NULL }
+};
+
+static const value_string opttype_vals[] = {
+	{ 1,	"DUID" },
+	{ 11,	"DNS servers address" },
+	{ 0,	NULL }
+};
+
+/* Returns the number of bytes consumed by this option. */
+static int
+dhcpv6_option(tvbuff_t *tvb, proto_tree *bp_tree, int off, int eoff,
+    gboolean *at_end)
+{
+	guint16	opttype;
+	guint16	optlen;
+	proto_item *ti;
+	proto_tree *subtree;
+	int i;
+	struct e_in6_addr in6;
+	guint16 duidtype;
+
+	/* option type and length must be present */
+	if (eoff - off < 4) {
+		*at_end = TRUE;
+		return 0;
+	}
+
+	opttype = tvb_get_ntohs(tvb, off);
+	optlen = tvb_get_ntohs(tvb, off + 2);
+
+	/* truncated case */
+	if (eoff - off < 4 + optlen) {
+		*at_end = TRUE;
+		return 0;
+	}
+
+	ti = proto_tree_add_text(bp_tree, tvb, off, 4 + optlen,
+		"%s", val_to_str(opttype, opttype_vals, "DHCP option %u"));
+
+	subtree = proto_item_add_subtree(ti, ett_dhcpv6_option);
+	proto_tree_add_text(subtree, tvb, off, 2, "option type: %d", opttype);
+	proto_tree_add_text(subtree, tvb, off + 2, 2, "option length: %d",
+		optlen);
+
+	off += 4;
+	switch (opttype) {
+	case 1:	/* DUID */
+		if (optlen < 2) {
+			proto_tree_add_text(subtree, tvb, off, optlen,
+				"DUID: malformed option");
+			break;
+		}
+		duidtype = tvb_get_ntohs(tvb, off);
+		proto_tree_add_text(subtree, tvb, off, 2,
+			"DUID type: %u", duidtype);
+		switch (duidtype) {
+		case 1:
+			if (optlen < 8) {
+				proto_tree_add_text(subtree, tvb, off,
+					optlen, "DUID: malformed option");
+				break;
+			}
+			/* XXX seconds since Jan 1 2000 */
+			proto_tree_add_text(subtree, tvb, off + 2, 4,
+				"Time: %u", tvb_get_ntohl(tvb, off + 6));
+			proto_tree_add_text(subtree, tvb, off + 6, 2,
+				"Hardware type: %u",
+				tvb_get_ntohs(tvb, off + 6));
+			if (optlen > 8) {
+				proto_tree_add_text(subtree, tvb, off + 8,
+					optlen - 8, "Link-layer address");
+			}
+			break;
+		case 2:
+			if (optlen < 10) {
+				proto_tree_add_text(subtree, tvb, off,
+					optlen, "DUID: malformed option");
+				break;
+			}
+			proto_tree_add_text(subtree, tvb, off + 2, 8, "VUID");
+			if (optlen > 10) {
+				proto_tree_add_text(subtree, tvb, off + 10,
+					optlen - 10, "Domain name");
+			}
+			break;
+		case 3:
+			if (optlen < 4) {
+				proto_tree_add_text(subtree, tvb, off,
+					optlen, "DUID: malformed option");
+				break;
+			}
+			proto_tree_add_text(subtree, tvb, off + 2, 2,
+				"Hardware type: %u",
+				tvb_get_ntohs(tvb, off + 10));
+			if (optlen > 4) {
+				proto_tree_add_text(subtree, tvb, off + 4,
+					optlen - 4, "Link-layer address");
+			}
+			break;
+		}
+		break;
+	case 11:	/* DNS servers address */
+		if (optlen % 16) {
+			proto_tree_add_text(subtree, tvb, off, optlen,
+				"DNS servers address: malformed option");
+			break;
+		}
+		for (i = 0; i < optlen; i += 16) {
+			tvb_memcpy(tvb, (guint8 *)&in6, off + i, sizeof(in6));
+			proto_tree_add_text(subtree, tvb, off + i,
+				sizeof(in6), "DNS servers address: %s",
+				ip6_to_str(&in6));
+		}
+		break;
+	}
+
+	return 4 + optlen;
+}
+
+static void
+dissect_dhcpv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int downstream)
+{
+	proto_tree *bp_tree = NULL;
+	proto_item *ti;
+	guint8 msgtype;
+	guint32 xid;
+	struct e_in6_addr in6;
+	int off, eoff;
+	gboolean at_end;
+
+	if (check_col(pinfo->cinfo, COL_PROTOCOL))
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, "DHCPv6");
+	if (check_col(pinfo->cinfo, COL_INFO))
+		col_clear(pinfo->cinfo, COL_INFO);
+
+	msgtype = tvb_get_guint8(tvb, 0);
+
+	/* XXX relay agent messages have to be decoded differently */
+
+	xid = tvb_get_ntohl(tvb, 0) & 0x00ffffff;
+
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_set_str(pinfo->cinfo, COL_INFO,
+			downstream ? "DHCPv6 reply" : "DHCPv6 request");
+	}
+
+	if (tree) {
+		ti = proto_tree_add_item(tree, proto_dhcpv6, tvb, 0,
+		    tvb_length(tvb), FALSE);
+		bp_tree = proto_item_add_subtree(ti, ett_dhcpv6);
+
+		proto_tree_add_uint(bp_tree, hf_dhcpv6_msgtype, tvb, 0, 1,
+			msgtype);
+		proto_tree_add_text(bp_tree, tvb, 1, 3, "XID: 0x%08x", xid);
+		tvb_memcpy(tvb, (guint8 *)&in6, 4, sizeof(in6));
+		proto_tree_add_text(bp_tree, tvb, 4, sizeof(in6),
+			"Server address: %s", ip6_to_str(&in6));
+	}
+
+	off = 20;
+	eoff = tvb_reported_length(tvb);
+
+	at_end = FALSE;
+	while (off < eoff && !at_end)
+		off += dhcpv6_option(tvb, bp_tree, off, eoff, &at_end);
+}
+
+static void
+dissect_dhcpv6_downstream(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	return dissect_dhcpv6(tvb, pinfo, tree, 1);
+}
+
+static void
+dissect_dhcpv6_upstream(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	return dissect_dhcpv6(tvb, pinfo, tree, 0);
+}
+
+
+void
+proto_register_dhcpv6(void)
+{
+  static hf_register_info hf[] = {
+    { &hf_dhcpv6_msgtype,
+      { "Message type",			"dhcpv6.msgtype",	 FT_UINT8,
+         BASE_DEC, 			VALS(msgtype_vals),   0x0,
+      	"", HFILL }},
+  };
+  static gint *ett[] = {
+    &ett_dhcpv6,
+    &ett_dhcpv6_option,
+  };
+  
+  proto_dhcpv6 = proto_register_protocol("DHCPv6", "DHCPv6", "dhcpv6");
+  proto_register_field_array(proto_dhcpv6, hf, array_length(hf));
+  proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_dhcpv6(void)
+{
+  dissector_handle_t dhcpv6_handle;
+
+  dhcpv6_handle = create_dissector_handle(dissect_dhcpv6_downstream,
+	proto_dhcpv6);
+  dissector_add("udp.port", UDP_PORT_DHCPV6_DOWNSTREAM, dhcpv6_handle);
+  dhcpv6_handle = create_dissector_handle(dissect_dhcpv6_upstream,
+	proto_dhcpv6);
+  dissector_add("udp.port", UDP_PORT_DHCPV6_UPSTREAM, dhcpv6_handle);
+}