* Routines for the Generic Routing Encapsulation (GRE) protocol
* Brad Robel-Forrest <brad.robel-forrest@watchguard.com>
*
- * $Id: packet-gre.c,v 1.35 2001/01/07 22:35:21 guy Exp $
+ * $Id: packet-gre.c,v 1.54 2003/06/10 05:38:52 guy Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * 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.
# include "config.h"
#endif
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
-#ifdef HAVE_NETINET_IN_H
-#include <netinet/in.h>
-#endif
#include <glib.h>
-#include "packet.h"
-#include "packet-ip.h"
-#include "packet-ipx.h"
+#include <epan/packet.h>
#include "packet-wccp.h"
#include "in_cksum.h"
+#include "etypes.h"
+#include "greproto.h"
+#include "ipproto.h"
+#include "llcsaps.h"
+
+/*
+ * See RFC 1701 "Generic Routing Encapsulation (GRE)", RFC 1702
+ * "Generic Routing Encapsulation over IPv4 networks", RFC 2637
+ * "Point-to-Point Tunneling Protocol (PPTP)", RFC 2784 "Generic
+ * Routing Encapsulation (GRE)", and RFC 2890 "Key and Sequence
+ * Number Extensions to GRE".
+ */
static int proto_gre = -1;
static int hf_gre_proto = -1;
static gint ett_gre_flags = -1;
static gint ett_gre_wccp2_redirect_header = -1;
+static dissector_table_t gre_dissector_table;
+static dissector_handle_t data_handle;
+
/* bit positions for flags in header */
#define GH_B_C 0x8000
#define GH_B_R 0x4000
#define GH_R_FLAGS 0x00F8
#define GH_B_VER 0x0007
-#define GRE_PPP 0x880B
-#define GRE_IP 0x0800
-#define GRE_WCCP 0x883E
-#define GRE_IPX 0x8137
-#define GRE_FR 0x6559
-
static void add_flags_and_ver(proto_tree *, guint16, tvbuff_t *, int, int);
static void dissect_gre_wccp2_redirect_header(tvbuff_t *, int, proto_tree *);
static const value_string typevals[] = {
- { GRE_PPP, "PPP" },
- { GRE_IP, "IP" },
- { GRE_WCCP, "WCCP"},
- { GRE_IPX, "IPX"},
- { GRE_FR, "FR"},
- { 0, NULL }
+ { ETHERTYPE_PPP, "PPP" },
+ { ETHERTYPE_IP, "IP" },
+ { SAP_OSINL5, "OSI"},
+ { GRE_WCCP, "WCCP"},
+ { ETHERTYPE_IPX, "IPX"},
+ { ETHERTYPE_ETHBRIDGE, "Transparent Ethernet bridging" },
+ { GRE_FR, "Frame Relay"},
+ { 0, NULL }
};
-static dissector_handle_t ip_handle;
-static dissector_handle_t ppp_handle;
-static dissector_handle_t fr_handle;
-
static void
dissect_gre(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 sre_length;
tvbuff_t *next_tvb;
- CHECK_DISPLAY_AS_DATA(proto_gre, tvb, pinfo, tree);
-
- pinfo->current_proto = "GRE";
-
flags_and_ver = tvb_get_ntohs(tvb, offset);
type = tvb_get_ntohs(tvb, offset + sizeof(flags_and_ver));
- if (check_col(pinfo->fd, COL_PROTOCOL))
- col_set_str(pinfo->fd, COL_PROTOCOL, "GRE");
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "GRE");
- if (check_col(pinfo->fd, COL_INFO)) {
- col_add_fstr(pinfo->fd, COL_INFO, "Encapsulated %s",
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_add_fstr(pinfo->cinfo, COL_INFO, "Encapsulated %s",
val_to_str(type, typevals, "0x%04X (unknown)"));
}
len += 4;
switch (type) {
- case GRE_PPP:
+ case ETHERTYPE_PPP:
if (flags_and_ver & GH_P_A)
len += 4;
is_ppp = TRUE;
offset += 4;
}
}
-
+
if (flags_and_ver & GH_B_S) {
if (tree) {
proto_tree_add_text(gre_tree, tvb, offset, 4,
}
}
- next_tvb = tvb_new_subset(tvb, offset, -1, -1);
- switch (type) {
- case GRE_PPP:
- call_dissector(ppp_handle, next_tvb, pinfo, tree);
- break;
- case GRE_IP:
- call_dissector(ip_handle, next_tvb, pinfo, tree);
- break;
- case GRE_WCCP:
- if (is_wccp2) {
- if (tree)
- dissect_gre_wccp2_redirect_header(tvb, offset, gre_tree);
- offset += 4;
- }
- call_dissector(ip_handle, next_tvb, pinfo, tree);
- break;
- case GRE_IPX:
- dissect_ipx(next_tvb, pinfo, tree);
- break;
- case GRE_FR:
- call_dissector(fr_handle, next_tvb, pinfo, tree);
- break;
- default:
- dissect_data(next_tvb, 0, pinfo, gre_tree);
- break;
+ if (type == GRE_WCCP) {
+ if (is_wccp2) {
+ if (tree)
+ dissect_gre_wccp2_redirect_header(tvb, offset, gre_tree);
+ offset += 4;
+ }
}
+
+ /* If the S bit is not set, this packet might not have a payload, so
+ check whether there's any data left, first.
+
+ XXX - the S bit isn't in RFC 2784, which deprecates that bit
+ and some other bits in RFC 1701 and says that they should be
+ zero for RFC 2784-compliant GRE; as such, the absence of the
+ S bit doesn't necessarily mean there's no payload. */
+ if (!(flags_and_ver & GH_B_S)) {
+ if (tvb_reported_length_remaining(tvb, offset) <= 0)
+ return; /* no payload */
+ }
+ next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+ if (!dissector_try_port(gre_dissector_table, type, next_tvb, pinfo, tree))
+ call_dissector(data_handle,next_tvb, pinfo, gre_tree);
}
static void
proto_item * ti;
proto_tree * fv_tree;
int nbits = sizeof(flags_and_ver) * 8;
-
- ti = proto_tree_add_text(tree, tvb, offset, 2,
+
+ ti = proto_tree_add_text(tree, tvb, offset, 2,
"Flags and version: %#04x", flags_and_ver);
fv_tree = proto_item_add_subtree(ti, ett_gre_flags);
-
+
proto_tree_add_text(fv_tree, tvb, offset, sizeof(flags_and_ver), "%s",
decode_boolean_bitfield(flags_and_ver, GH_B_C, nbits,
"Checksum", "No checksum"));
proto_item * ti;
proto_tree * rh_tree;
guint8 rh_flags;
-
+
ti = proto_tree_add_text(tree, tvb, offset, 4, "Redirect header");
rh_tree = proto_item_add_subtree(ti, ett_gre_wccp2_redirect_header);
proto_tree_add_text(rh_tree, tvb, offset + 3, 1, "Primary bucket index: %u",
tvb_get_guint8(tvb, offset + 3));
}
-
+
void
proto_register_gre(void)
{
static hf_register_info hf[] = {
{ &hf_gre_proto,
{ "Protocol Type", "gre.proto", FT_UINT16, BASE_HEX, VALS(typevals), 0x0,
- "The protocol that is GRE encapsulated"}
+ "The protocol that is GRE encapsulated", HFILL }
},
};
static gint *ett[] = {
"GRE", "gre");
proto_register_field_array(proto_gre, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
+
+ /* subdissector code */
+ gre_dissector_table = register_dissector_table("gre.proto",
+ "GRE protocol type", FT_UINT16, BASE_HEX);
}
void
proto_reg_handoff_gre(void)
{
- dissector_add("ip.proto", IP_PROTO_GRE, dissect_gre);
-
- /*
- * Get handles for the IP, PPP, and Frame Relay dissectors.
- */
- ip_handle = find_dissector("ip");
- ppp_handle = find_dissector("ppp");
- fr_handle = find_dissector("fr");
+ dissector_handle_t gre_handle;
+
+ gre_handle = create_dissector_handle(dissect_gre, proto_gre);
+ dissector_add("ip.proto", IP_PROTO_GRE, gre_handle);
+ data_handle = find_dissector("data");
}
git.samba.org / obnox / wireshark / wip.git / blobdiff