1999-06-11 15:30:55 +00:00
/* packet-gre.c
* Routines for the Generic Routing Encapsulation ( GRE ) protocol
* Brad Robel - Forrest < brad . robel - forrest @ watchguard . com >
*
2006-05-21 04:49:01 +00:00
* Wireshark - Network traffic analyzer
* By Gerald Combs < gerald @ wireshark . org >
1999-06-11 15:30:55 +00:00
* Copyright 1998 Gerald Combs
2002-08-28 21:04:11 +00:00
*
1999-06-11 15:30:55 +00:00
* 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 .
2002-08-28 21:04:11 +00:00
*
1999-06-11 15:30:55 +00:00
* 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 .
2002-08-28 21:04:11 +00:00
*
1999-06-11 15:30:55 +00:00
* You should have received a copy of the GNU General Public License
* along with this program ; if not , write to the Free Software
2012-06-28 22:56:06 +00:00
* Foundation , Inc . , 51 Franklin Street , Fifth Floor , Boston , MA 02110 - 1301 USA .
1999-06-11 15:30:55 +00:00
*/
2012-09-20 02:03:38 +00:00
# include "config.h"
1999-06-11 15:30:55 +00:00
# include <glib.h>
2002-01-21 07:37:49 +00:00
# include <epan/packet.h>
2005-09-17 00:02:31 +00:00
# include <epan/etypes.h>
2012-05-17 14:35:11 +00:00
# include <epan/in_cksum.h>
# include <epan/expert.h>
2005-09-17 00:02:31 +00:00
# include <epan/greproto.h>
2004-09-29 00:52:45 +00:00
# include <epan/ipproto.h>
2005-09-17 00:02:31 +00:00
# include <epan/llcsaps.h>
2012-05-17 14:35:11 +00:00
# include "packet-gre.h"
# include "packet-wccp.h"
1999-06-11 15:30:55 +00:00
2013-12-15 23:44:12 +00:00
void proto_register_gre ( void ) ;
void proto_reg_handoff_gre ( void ) ;
2001-10-23 19:02:59 +00:00
/*
* 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
2004-05-15 19:54:10 +00:00
* Routing Encapsulation ( GRE ) " , RFC 2890 " Key and Sequence
* Number Extensions to GRE " and draft-ietf-mpls-in-ip-or-gre-07.txt
* " Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE) " .
2001-10-23 19:02:59 +00:00
*/
1999-07-29 05:47:07 +00:00
static int proto_gre = - 1 ;
1999-12-12 03:05:57 +00:00
static int hf_gre_proto = - 1 ;
2010-10-19 18:28:00 +00:00
static int hf_gre_flags_and_version = - 1 ;
static int hf_gre_flags_checksum = - 1 ;
static int hf_gre_flags_routing = - 1 ;
static int hf_gre_flags_key = - 1 ;
static int hf_gre_flags_sequence_number = - 1 ;
static int hf_gre_flags_strict_source_route = - 1 ;
static int hf_gre_flags_recursion_control = - 1 ;
static int hf_gre_flags_ack = - 1 ;
static int hf_gre_flags_reserved_ppp = - 1 ;
static int hf_gre_flags_reserved = - 1 ;
static int hf_gre_flags_version = - 1 ;
static int hf_gre_checksum = - 1 ;
static int hf_gre_offset = - 1 ;
2004-09-23 17:15:26 +00:00
static int hf_gre_key = - 1 ;
2010-10-19 18:28:00 +00:00
static int hf_gre_key_payload_length = - 1 ;
static int hf_gre_key_call_id = - 1 ;
static int hf_gre_sequence_number = - 1 ;
static int hf_gre_ack_number = - 1 ;
static int hf_gre_routing = - 1 ;
static int hf_gre_routing_address_family = - 1 ;
static int hf_gre_routing_sre_length = - 1 ;
static int hf_gre_routing_sre_offset = - 1 ;
static int hf_gre_routing_information = - 1 ;
1999-07-29 05:47:07 +00:00
2006-03-27 16:23:00 +00:00
/* Ref 3GPP2 A.S0012-C v2.0 and A.S0008-A v1.0 */
2010-10-19 18:28:00 +00:00
static int hf_gre_3ggp2_attrib = - 1 ;
static int hf_gre_3ggp2_attrib_id = - 1 ;
2006-03-27 16:23:00 +00:00
static int hf_gre_3ggp2_attrib_length = - 1 ;
static int hf_gre_3ggp2_sdi = - 1 ;
static int hf_gre_3ggp2_fci = - 1 ;
static int hf_gre_3ggp2_di = - 1 ;
static int hf_gre_3ggp2_flow_disc = - 1 ;
static int hf_gre_3ggp2_seg = - 1 ;
2010-10-19 18:28:00 +00:00
static int hf_gre_wccp_redirect_header = - 1 ;
static int hf_gre_wccp_dynamic_service = - 1 ;
static int hf_gre_wccp_alternative_bucket_used = - 1 ;
2013-05-11 10:46:36 +00:00
static int hf_gre_wccp_redirect_header_valid = - 1 ;
2010-10-19 18:28:00 +00:00
static int hf_gre_wccp_service_id = - 1 ;
static int hf_gre_wccp_alternative_bucket = - 1 ;
static int hf_gre_wccp_primary_bucket = - 1 ;
1999-11-16 11:44:20 +00:00
static gint ett_gre = - 1 ;
static gint ett_gre_flags = - 1 ;
2010-10-19 18:28:00 +00:00
static gint ett_gre_routing = - 1 ;
2000-11-29 06:17:34 +00:00
static gint ett_gre_wccp2_redirect_header = - 1 ;
2006-03-24 07:09:35 +00:00
static gint ett_3gpp2_attribs = - 1 ;
2006-03-29 17:00:16 +00:00
static gint ett_3gpp2_attr = - 1 ;
1999-11-16 11:44:20 +00:00
2013-05-26 03:29:07 +00:00
static expert_field ei_gre_checksum_incorrect = EI_INIT ;
2001-01-13 07:47:49 +00:00
static dissector_table_t gre_dissector_table ;
2001-11-25 22:51:14 +00:00
static dissector_handle_t data_handle ;
2001-01-13 07:47:49 +00:00
1999-06-11 15:30:55 +00:00
/* bit positions for flags in header */
2012-05-17 14:35:11 +00:00
# define GRE_CHECKSUM 0x8000
# define GRE_ROUTING 0x4000
# define GRE_KEY 0x2000
# define GRE_SEQUENCE 0x1000
# define GRE_STRICTSOURCE 0x0800
# define GRE_RECURSION 0x0700
# define GRE_ACK 0x0080 /* only in special PPTPized GRE header */
# define GRE_RESERVED_PPP 0x0078 /* only in special PPTPized GRE header */
# define GRE_RESERVED 0x00F8
# define GRE_VERSION 0x0007
2010-10-19 18:28:00 +00:00
const value_string gre_version [ ] = {
2012-05-17 14:35:11 +00:00
{ 0 , " GRE " } , /* [RFC2784] */
{ 1 , " Enhanced GRE " } , /* [RFC2637] */
{ 0 , NULL }
2010-10-19 18:28:00 +00:00
} ;
2007-12-16 22:46:42 +00:00
const value_string gre_typevals [ ] = {
2013-05-11 10:46:36 +00:00
{ GRE_KEEPALIVE , " Possible GRE keepalive packet " } ,
2012-05-17 14:35:11 +00:00
{ ETHERTYPE_PPP , " PPP " } ,
{ ETHERTYPE_IP , " IP " } ,
{ SAP_OSINL5 , " OSI " } ,
{ GRE_WCCP , " WCCP " } ,
{ GRE_NHRP , " NHRP " } ,
{ GRE_ERSPAN_88BE , " ERSPAN " } ,
{ GRE_ERSPAN_22EB , " ERSPAN " } ,
{ ETHERTYPE_IPX , " IPX " } ,
{ ETHERTYPE_ETHBRIDGE , " Transparent Ethernet bridging " } ,
{ ETHERTYPE_RAW_FR , " Frame Relay " } ,
{ ETHERTYPE_IPv6 , " IPv6 " } ,
{ ETHERTYPE_MPLS , " MPLS label switched packet " } ,
{ ETHERTYPE_CDMA2000_A10_UBS , " CDMA2000 A10 Unstructured byte stream " } ,
{ ETHERTYPE_3GPP2 , " CDMA2000 A10 3GPP2 Packet " } ,
{ GRE_ARUBA_8200 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8210 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8220 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8230 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8240 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8250 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8260 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8270 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8280 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8290 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82A0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82B0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82C0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82D0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82E0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_82F0 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8300 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8310 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8320 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8330 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8340 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8350 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8360 , " ARUBA WLAN " } ,
{ GRE_ARUBA_8370 , " ARUBA WLAN " } ,
{ GRE_ARUBA_9000 , " ARUBA WLAN " } ,
{ 0 , NULL }
1999-12-12 03:05:57 +00:00
} ;
2006-03-24 07:09:35 +00:00
# define ID_3GPP2_SDI_FLAG 1
# define ID_3GPP2_FLOW_CTRL 2
# define ID_3GPP2_FLOW_DISCRIMINATOR 3
# define ID_3GPP2_SEG 4
2006-03-27 16:23:00 +00:00
static const value_string gre_3ggp2_seg_vals [ ] = {
2012-05-17 14:35:11 +00:00
{ 0x00 , " Packet Started " } ,
{ 0x01 , " Packet continued " } ,
{ 0x02 , " Packet Ended " } ,
{ 0 , NULL }
2006-03-24 07:09:35 +00:00
} ;
2011-09-21 23:42:55 +00:00
/* 3GPP2 A.S0012-C v2.0
2006-03-27 16:23:00 +00:00
* 2.6 .1 GRE Attributes
*/
static const value_string gre_3ggp2_attrib_id_vals [ ] = {
2012-05-17 14:35:11 +00:00
{ 0x01 , " 1x SDB/HRPD DOS Indicator " } ,
{ 0x02 , " Flow Control Indication " } ,
/* A.S0008-A v1.0 */
{ 0x03 , " IP Flow Discriminator " } ,
{ 0x04 , " Segmentation Indication " } ,
{ 0 , NULL }
2006-03-27 16:23:00 +00:00
} ;
static const true_false_string gre_3ggp2_sdi_val = {
2012-05-17 14:35:11 +00:00
" Packet suitable for 1x SDB or HRPD DOS transmission " ,
" Reserved "
2006-03-27 16:23:00 +00:00
} ;
static const true_false_string gre_3ggp2_fci_val = {
2012-05-17 14:35:11 +00:00
" XOFF " ,
" XON "
2006-03-27 16:23:00 +00:00
} ;
static const true_false_string gre_3ggp2_di_val = {
2012-05-17 14:35:11 +00:00
" INDEFINITE: " ,
" TEMPORARY "
2006-03-27 16:23:00 +00:00
} ;
2006-03-24 07:09:35 +00:00
2010-10-19 18:28:00 +00:00
static const true_false_string gre_wccp_dynamic_service_val = {
2012-05-17 14:35:11 +00:00
" Dynamic service " ,
" Well-known service "
2010-10-19 18:28:00 +00:00
} ;
static const true_false_string gre_wccp_alternative_bucket_used_val = {
2012-05-17 14:35:11 +00:00
" Alternative bucket used " ,
" Primary bucket used " ,
2010-10-19 18:28:00 +00:00
} ;
2013-05-11 10:46:36 +00:00
static const true_false_string gre_wccp_redirect_header_valid_val = {
" Header is present, but ignore contents " ,
" Header contents are valid " ,
} ;
2006-03-24 07:09:35 +00:00
static int
dissect_gre_3gpp2_attribs ( tvbuff_t * tvb , int offset , proto_tree * tree )
{
2012-05-17 14:35:11 +00:00
gboolean last_attrib = FALSE ;
proto_item * attr_item ;
proto_tree * attr_tree ;
guint8 value ;
int start_offset = offset ;
2006-03-24 07:09:35 +00:00
2012-05-17 14:35:11 +00:00
proto_item * ti = proto_tree_add_item ( tree , hf_gre_3ggp2_attrib , tvb , offset , 0 , ENC_NA ) ;
proto_tree * atree = proto_item_add_subtree ( ti , ett_3gpp2_attribs ) ;
2006-03-24 07:09:35 +00:00
2012-05-17 14:35:11 +00:00
while ( last_attrib ! = TRUE )
{
guint8 attrib_id = tvb_get_guint8 ( tvb , offset ) ;
guint8 attrib_length = tvb_get_guint8 ( tvb , offset + 1 ) ;
2006-03-24 07:09:35 +00:00
2012-05-17 14:35:11 +00:00
attr_item = proto_tree_add_text ( atree , tvb , offset , attrib_length + 1 + 1 , " %s " ,
val_to_str ( ( attrib_id & 0x7f ) , gre_3ggp2_attrib_id_vals , " %u (Unknown) " ) ) ;
attr_tree = proto_item_add_subtree ( attr_item , ett_3gpp2_attr ) ;
2006-03-29 17:00:16 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_attrib_id , tvb , offset , 1 , ENC_BIG_ENDIAN ) ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_attrib_length , tvb , offset + 1 , 1 , ENC_BIG_ENDIAN ) ;
2006-03-27 16:23:00 +00:00
2012-05-17 14:35:11 +00:00
offset + = 2 ;
last_attrib = ( attrib_id & 0x80 ) ? TRUE : FALSE ;
attrib_id & = 0x7F ;
2006-03-24 07:09:35 +00:00
2012-05-17 14:35:11 +00:00
switch ( attrib_id )
{
2006-03-24 07:09:35 +00:00
case ID_3GPP2_FLOW_DISCRIMINATOR :
2012-05-17 14:35:11 +00:00
{
value = tvb_get_guint8 ( tvb , offset ) ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_flow_disc , tvb , offset , attrib_length , ENC_NA ) ;
proto_item_append_text ( attr_item , " - 0x%x " , value ) ;
}
break ;
2006-03-24 07:09:35 +00:00
case ID_3GPP2_SDI_FLAG :
2012-05-17 14:35:11 +00:00
{
value = tvb_get_guint8 ( tvb , offset ) ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_sdi , tvb , offset , attrib_length , ENC_BIG_ENDIAN ) ;
proto_item_append_text ( attr_item , " - %s " ,
( value & 0x80 ) ? " Packet suitable for 1x SDB or HRPD DOS transmission " : " Reserved " ) ;
}
break ;
2006-03-24 07:09:35 +00:00
case ID_3GPP2_SEG :
2012-05-17 14:35:11 +00:00
{
value = tvb_get_guint8 ( tvb , offset ) > > 6 ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_seg , tvb , offset , attrib_length , ENC_BIG_ENDIAN ) ;
proto_item_append_text ( attr_item , " - %s " , val_to_str ( value , gre_3ggp2_seg_vals , " 0x%02X - Unknown " ) ) ;
}
break ;
2006-03-24 07:09:35 +00:00
case ID_3GPP2_FLOW_CTRL :
2012-05-17 14:35:11 +00:00
{
value = tvb_get_guint8 ( tvb , offset ) ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_fci , tvb , offset , attrib_length , ENC_BIG_ENDIAN ) ;
proto_item_append_text ( attr_item , " - %s " ,
( value & 0x80 ) ? " XON " : " XOFF " ) ;
proto_tree_add_item ( attr_tree , hf_gre_3ggp2_di , tvb , offset , attrib_length , ENC_BIG_ENDIAN ) ;
proto_item_append_text ( attr_item , " /%s " ,
( value & 0x40 ) ? " INDEFINITE " : " TEMPORARY " ) ;
}
break ;
}
offset + = attrib_length ;
}
proto_item_set_len ( ti , offset - start_offset ) ;
return offset ;
2006-03-24 07:09:35 +00:00
}
2010-10-19 18:28:00 +00:00
static void
dissect_gre_wccp2_redirect_header ( tvbuff_t * tvb , int offset , proto_tree * tree )
{
2012-05-17 14:35:11 +00:00
proto_item * ti ;
proto_tree * rh_tree ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
ti = proto_tree_add_item ( tree , hf_gre_wccp_redirect_header , tvb , offset , 4 , ENC_NA ) ;
rh_tree = proto_item_add_subtree ( ti , ett_gre_wccp2_redirect_header ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_dynamic_service , tvb , offset , 1 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_alternative_bucket_used , tvb , offset , 1 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2013-05-11 10:46:36 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_redirect_header_valid , tvb , offset , 1 , FALSE ) ;
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_service_id , tvb , offset + 1 , 1 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_alternative_bucket , tvb , offset + 2 , 1 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( rh_tree , hf_gre_wccp_primary_bucket , tvb , offset + 3 , 1 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
}
2000-04-16 22:46:25 +00:00
static void
2000-11-29 07:42:35 +00:00
dissect_gre ( tvbuff_t * tvb , packet_info * pinfo , proto_tree * tree )
{
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
int offset = 0 ;
guint16 flags_and_ver ;
guint16 type ;
gboolean is_ppp = FALSE ;
gboolean is_wccp2 = FALSE ;
proto_item * ti , * it_flags ;
proto_tree * gre_tree , * fv_tree = NULL ;
guint16 sre_af ;
guint8 sre_length ;
tvbuff_t * next_tvb ;
flags_and_ver = tvb_get_ntohs ( tvb , offset ) ;
type = tvb_get_ntohs ( tvb , offset + 2 ) ;
col_set_str ( pinfo - > cinfo , COL_PROTOCOL , " GRE " ) ;
col_add_fstr ( pinfo - > cinfo , COL_INFO , " Encapsulated %s " , val_to_str ( type , gre_typevals , " 0x%04X (unknown) " ) ) ;
switch ( type ) {
case ETHERTYPE_PPP :
if ( flags_and_ver & GRE_ACK )
is_ppp = TRUE ;
break ;
case ETHERTYPE_3GPP2 :
case ETHERTYPE_CDMA2000_A10_UBS :
is_ppp = TRUE ;
break ;
case GRE_WCCP :
/* WCCP2 puts an extra 4 octets into the header, but uses the same
encapsulation type ; if it looks as if the first octet of the packet
isn ' t the beginning of an IPv4 header , assume it ' s WCCP2 . */
if ( ( tvb_get_guint8 ( tvb , offset + 2 + 2 ) & 0xF0 ) ! = 0x40 ) {
is_wccp2 = TRUE ;
}
break ;
1999-12-12 03:05:57 +00:00
}
2012-05-17 14:35:11 +00:00
/* Per README.developer, section 1.2, we must call subdissectors regardless
* of whether " tree " is NULL or not . That is done below using
* call_dissector ( ) , but since the next_tvb must begin at the correct offset ,
* it ' s easier and more readable to always enter this block in order to
* compute the correct offset to pass to tvb_new_subset_remaining ( ) .
*/
if ( 1 ) {
ti = proto_tree_add_protocol_format ( tree , proto_gre , tvb , offset , - 1 , " Generic Routing Encapsulation (%s) " ,
val_to_str ( type , gre_typevals , " 0x%04X - unknown " ) ) ;
gre_tree = proto_item_add_subtree ( ti , ett_gre ) ;
1999-06-11 15:30:55 +00:00
2012-05-17 14:35:11 +00:00
it_flags = proto_tree_add_item ( gre_tree , hf_gre_flags_and_version , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
fv_tree = proto_item_add_subtree ( it_flags , ett_gre_flags ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_checksum , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_routing , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_key , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_sequence_number , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_strict_source_route , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_recursion_control , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
/* RFC2637 Section 4.1 : Enhanced GRE Header */
if ( is_ppp ) {
proto_tree_add_item ( fv_tree , hf_gre_flags_ack , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_reserved_ppp , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
}
else {
proto_tree_add_item ( fv_tree , hf_gre_flags_reserved , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
}
2010-10-19 18:28:00 +00:00
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( fv_tree , hf_gre_flags_version , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
offset + = 2 ;
2012-05-17 14:35:11 +00:00
proto_tree_add_item ( gre_tree , hf_gre_proto , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
2010-10-19 18:28:00 +00:00
offset + = 2 ;
2000-11-29 06:17:34 +00:00
2012-05-17 14:35:11 +00:00
if ( flags_and_ver & GRE_CHECKSUM | | flags_and_ver & GRE_ROUTING ) {
guint length , reported_length ;
proto_item * it_checksum ;
vec_t cksum_vec [ 1 ] ;
guint16 cksum , computed_cksum ;
it_checksum = proto_tree_add_item ( gre_tree , hf_gre_checksum , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
/* Checksum check !... */
cksum = tvb_get_ntohs ( tvb , offset ) ;
length = tvb_length ( tvb ) ;
reported_length = tvb_reported_length ( tvb ) ;
/* The Checksum Present bit is set, and the packet isn't part of a
fragmented datagram and isn ' t truncated , so we can checksum it . */
if ( ( flags_and_ver & GRE_CHECKSUM ) & & ! pinfo - > fragmented & & length > = reported_length ) {
cksum_vec [ 0 ] . ptr = tvb_get_ptr ( tvb , 0 , reported_length ) ;
cksum_vec [ 0 ] . len = reported_length ;
computed_cksum = in_cksum ( cksum_vec , 1 ) ;
if ( computed_cksum = = 0 ) {
proto_item_append_text ( it_checksum , " [correct] " ) ;
} else {
proto_item_append_text ( it_checksum , " [incorrect, should be 0x%04x] " , in_cksum_shouldbe ( cksum , computed_cksum ) ) ;
2013-05-26 03:29:07 +00:00
expert_add_info ( pinfo , it_checksum , & ei_gre_checksum_incorrect ) ;
2012-05-17 14:35:11 +00:00
}
}
offset + = 2 ;
proto_tree_add_item ( gre_tree , hf_gre_offset , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
offset + = 2 ;
}
if ( flags_and_ver & GRE_KEY ) {
/* RFC2637 Section 4.1 : Enhanced GRE Header */
if ( is_ppp & & type ! = ETHERTYPE_CDMA2000_A10_UBS ) {
proto_tree_add_item ( gre_tree , hf_gre_key_payload_length , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
offset + = 2 ;
proto_tree_add_item ( gre_tree , hf_gre_key_call_id , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
offset + = 2 ;
}
else {
proto_tree_add_item ( gre_tree , hf_gre_key , tvb , offset , 4 , ENC_BIG_ENDIAN ) ;
offset + = 4 ;
}
}
if ( flags_and_ver & GRE_SEQUENCE ) {
proto_tree_add_item ( gre_tree , hf_gre_sequence_number , tvb , offset , 4 , ENC_BIG_ENDIAN ) ;
offset + = 4 ;
}
if ( is_ppp & & ( flags_and_ver & GRE_ACK ) ) {
proto_tree_add_item ( gre_tree , hf_gre_ack_number , tvb , offset , 4 , ENC_BIG_ENDIAN ) ;
offset + = 4 ;
}
if ( flags_and_ver & GRE_ROUTING ) {
proto_item * it_routing ;
proto_tree * r_tree ;
for ( ; ; ) {
it_routing = proto_tree_add_item ( gre_tree , hf_gre_routing , tvb , offset , - 1 , ENC_NA ) ;
r_tree = proto_item_add_subtree ( ti , ett_gre_routing ) ;
sre_af = tvb_get_ntohs ( tvb , offset ) ;
proto_tree_add_item ( r_tree , hf_gre_routing_address_family , tvb , offset , 2 , ENC_BIG_ENDIAN ) ;
offset + = 2 ;
proto_tree_add_item ( r_tree , hf_gre_routing_sre_offset , tvb , offset , 1 , ENC_BIG_ENDIAN ) ;
offset + = 1 ;
sre_length = tvb_get_guint8 ( tvb , offset ) ;
proto_tree_add_item ( r_tree , hf_gre_routing_sre_length , tvb , offset , 1 , ENC_BIG_ENDIAN ) ;
offset + = 1 ;
proto_item_set_len ( it_routing , 2 + 1 + 1 + sre_length ) ;
if ( sre_af = = 0 & & sre_length = = 0 )
break ;
proto_tree_add_item ( r_tree , hf_gre_routing_information , tvb , offset , sre_length , ENC_NA ) ;
offset + = sre_length ;
}
}
if ( type = = GRE_WCCP & & is_wccp2 ) {
dissect_gre_wccp2_redirect_header ( tvb , offset , gre_tree ) ;
offset + = 4 ;
}
if ( type = = ETHERTYPE_3GPP2 ) {
offset = dissect_gre_3gpp2_attribs ( tvb , offset , gre_tree ) ;
}
proto_item_set_len ( ti , offset ) ;
/* 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 & GRE_SEQUENCE ) ) {
if ( tvb_reported_length_remaining ( tvb , offset ) < = 0 )
return ; /* no payload */
}
next_tvb = tvb_new_subset_remaining ( tvb , offset ) ;
pinfo - > flags . in_gre_pkt = TRUE ;
if ( ! dissector_try_uint ( gre_dissector_table , type , next_tvb , pinfo , tree ) )
call_dissector ( data_handle , next_tvb , pinfo , gre_tree ) ;
2010-10-19 18:28:00 +00:00
}
2000-11-29 06:17:34 +00:00
}
2002-08-28 21:04:11 +00:00
2010-10-19 18:28:00 +00:00
1999-07-29 05:47:07 +00:00
void
proto_register_gre ( void )
{
2010-10-19 18:28:00 +00:00
static hf_register_info hf [ ] = {
2012-05-17 14:35:11 +00:00
{ & hf_gre_proto ,
{ " Protocol Type " , " gre.proto " ,
FT_UINT16 , BASE_HEX , VALS ( gre_typevals ) , 0x0 ,
" The protocol that is GRE encapsulated " , HFILL }
} ,
{ & hf_gre_flags_and_version ,
{ " Flags and Version " , " gre.flags_and_version " ,
FT_UINT16 , BASE_HEX , NULL , 0x0 ,
" The GRE flags are encoded in the first two octets " , HFILL }
} ,
{ & hf_gre_flags_checksum ,
{ " Checksum Bit " , " gre.flags.checksum " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_CHECKSUM ,
" Indicates if the Checksum field is present " , HFILL }
} ,
{ & hf_gre_flags_routing ,
{ " Routing Bit " , " gre.flags.routing " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_ROUTING ,
" Indicates if the Routing and Checksum/Offset field are present " , HFILL }
} ,
{ & hf_gre_flags_key ,
{ " Key Bit " , " gre.flags.key " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_KEY ,
" Indicates if the Key field is present " , HFILL }
} ,
{ & hf_gre_flags_sequence_number ,
{ " Sequence Number Bit " , " gre.flags.sequence_number " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_SEQUENCE ,
" Indicates if the Sequence Number field is present " , HFILL }
} ,
{ & hf_gre_flags_strict_source_route ,
{ " Strict Source Route Bit " , " gre.flags.strict_source_route " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_STRICTSOURCE ,
NULL , HFILL }
} ,
{ & hf_gre_flags_recursion_control ,
{ " Recursion control " , " gre.flags.recursion_control " ,
FT_UINT16 , BASE_DEC , NULL , GRE_RECURSION ,
NULL , HFILL }
} ,
{ & hf_gre_flags_ack ,
{ " Acknowledgment " , " gre.flags.ack " ,
FT_BOOLEAN , 16 , TFS ( & tfs_yes_no ) , GRE_ACK ,
" Indicates if the packet packet contains Acknowledgment Number to be used for acknowledging previously transmitted data " , HFILL }
} ,
{ & hf_gre_flags_reserved ,
{ " Flags (Reserved) " , " gre.flags.reserved " ,
FT_UINT16 , BASE_DEC , NULL , GRE_RESERVED ,
NULL , HFILL }
} ,
{ & hf_gre_flags_reserved_ppp ,
{ " Flags (Reserved) " , " gre.flags.reserved " ,
FT_UINT16 , BASE_DEC , NULL , GRE_RESERVED_PPP ,
NULL , HFILL }
} ,
{ & hf_gre_flags_version ,
{ " Version " , " gre.flags.version " ,
FT_UINT16 , BASE_DEC , VALS ( gre_version ) , GRE_VERSION ,
NULL , HFILL }
} ,
{ & hf_gre_checksum ,
{ " Checksum " , " gre.checksum " ,
FT_UINT16 , BASE_HEX , NULL , 0x0 ,
" The Checksum field contains the IP (one's complement) checksum of the GRE header and the payload packet " , HFILL }
} ,
{ & hf_gre_offset ,
{ " Offset " , " gre.offset " ,
FT_UINT16 , BASE_DEC , NULL , 0x0 ,
" The offset field indicates the octet offset from the start of the Routing field to the first octet of the active Source Route Entry to be examined " , HFILL }
} ,
{ & hf_gre_key ,
{ " Key " , " gre.key " ,
FT_UINT32 , BASE_HEX , NULL , 0x0 ,
" The Key field contains a four octet number which was inserted by the encapsulator " , HFILL }
} ,
{ & hf_gre_key_payload_length ,
{ " Payload Length " , " gre.key.payload_length " ,
FT_UINT16 , BASE_DEC , NULL , 0x0 ,
" Size of the payload, not including the GRE header " , HFILL }
} ,
{ & hf_gre_key_call_id ,
{ " Call ID " , " gre.key.call_id " ,
FT_UINT16 , BASE_DEC , NULL , 0x0 ,
" Contains the Peer's Call ID for the session to which this packet belongs. " , HFILL }
} ,
{ & hf_gre_sequence_number ,
{ " Sequence Number " , " gre.sequence_number " ,
FT_UINT32 , BASE_DEC , NULL , 0x0 ,
" The Sequence Number field contains an unsigned 32 bit integer which is inserted by the encapsulator " , HFILL }
} ,
{ & hf_gre_ack_number ,
{ " Acknowledgment Number " , " gre.ack_number " ,
FT_UINT32 , BASE_DEC , NULL , 0x0 ,
" Contains the sequence number of the highest numbered GRE packet received by the sending peer for this user session " , HFILL }
} ,
{ & hf_gre_routing ,
{ " Routing " , " gre.routing " ,
FT_NONE , BASE_NONE , NULL , 0x0 ,
" The Routing field is a list of Source Route Entries (SREs) " , HFILL }
} ,
{ & hf_gre_routing_address_family ,
{ " Address Family " , " gre.routing.address_family " ,
FT_UINT16 , BASE_DEC , NULL , 0x0 ,
" The Address Family field contains a two octet value which indicates the syntax and semantics of the Routing Information field " , HFILL }
} ,
{ & hf_gre_routing_sre_offset ,
{ " SRE Offset " , " gre.routing.sre_offset " ,
FT_UINT8 , BASE_DEC , NULL , 0x0 ,
" The Address Family field contains a two octet value which indicates the syntax and semantics of the Routing Information field " , HFILL }
} ,
{ & hf_gre_routing_sre_length ,
{ " SRE Length " , " gre.routing.src_length " ,
FT_UINT8 , BASE_DEC , NULL , 0x0 ,
" The SRE Length field contains the number of octets in the SRE " , HFILL }
} ,
{ & hf_gre_routing_information ,
{ " Routing Information " , " gre.routing.information " ,
FT_BYTES , BASE_NONE , NULL , 0x0 ,
" The Routing Information field contains data which may be used in routing this packet " , HFILL }
} ,
{ & hf_gre_3ggp2_attrib ,
{ " 3GGP2 Attributes " , " gre.ggp2_attrib " ,
FT_NONE , BASE_NONE , NULL , 0x0 ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_attrib_id ,
{ " Type " , " gre.ggp2_attrib_id " ,
FT_UINT8 , BASE_HEX , VALS ( gre_3ggp2_attrib_id_vals ) , 0x7f ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_attrib_length ,
{ " Length " , " gre.ggp2_attrib_length " ,
FT_UINT8 , BASE_HEX , NULL , 0x0 ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_sdi ,
{ " SDI/DOS " , " gre.3ggp2_sdi " ,
FT_BOOLEAN , 16 , TFS ( & gre_3ggp2_sdi_val ) , 0x8000 ,
" Short Data Indicator(SDI)/Data Over Signaling (DOS) " , HFILL }
} ,
{ & hf_gre_3ggp2_fci ,
{ " Flow Control Indicator " , " gre.3ggp2_fci " ,
FT_BOOLEAN , 16 , TFS ( & gre_3ggp2_fci_val ) , 0x8000 ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_di ,
{ " Duration Indicator " , " gre.3ggp2_di " ,
FT_BOOLEAN , 16 , TFS ( & gre_3ggp2_di_val ) , 0x4000 ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_flow_disc ,
{ " Flow ID " , " gre.ggp2_flow_disc " ,
FT_BYTES , BASE_NONE , NULL , 0x0 ,
NULL , HFILL }
} ,
{ & hf_gre_3ggp2_seg ,
{ " Type " , " gre.ggp2_3ggp2_seg " ,
FT_UINT16 , BASE_HEX , VALS ( gre_3ggp2_seg_vals ) , 0xc000 ,
NULL , HFILL }
} ,
{ & hf_gre_wccp_redirect_header ,
{ " Redirect Header " , " gre.wccp.redirect_header " ,
FT_NONE , BASE_NONE , NULL , 0x0 ,
NULL , HFILL }
} ,
{ & hf_gre_wccp_dynamic_service ,
{ " Dynamic Service " , " gre.wccp.dynamic_service " ,
2013-05-11 10:46:36 +00:00
FT_BOOLEAN , 8 , TFS ( & gre_wccp_dynamic_service_val ) , 0x01 ,
2012-05-17 14:35:11 +00:00
NULL , HFILL }
} ,
{ & hf_gre_wccp_alternative_bucket_used ,
{ " Alternative bucket used " , " gre.wccp.alternative_bucket_used " ,
2013-05-11 10:46:36 +00:00
FT_BOOLEAN , 8 , TFS ( & gre_wccp_alternative_bucket_used_val ) , 0x02 ,
NULL , HFILL }
} ,
{ & hf_gre_wccp_redirect_header_valid ,
{ " WCCP Redirect header is valid " , " gre.wccp.redirect_header_valid " ,
FT_BOOLEAN , 8 , TFS ( & gre_wccp_redirect_header_valid_val ) , 0x04 ,
2012-05-17 14:35:11 +00:00
NULL , HFILL }
} ,
{ & hf_gre_wccp_service_id ,
{ " Service ID " , " gre.wccp.service_id " ,
FT_UINT8 , BASE_DEC , VALS ( service_id_vals ) , 0x00 ,
" Service Group identifier " , HFILL }
} ,
{ & hf_gre_wccp_alternative_bucket ,
{ " Alternative Bucket " , " gre.wccp.alternative_bucket " ,
FT_UINT8 , BASE_DEC , NULL , 0x0 ,
" Alternative bucket index used to redirect the packet. " , HFILL }
} ,
{ & hf_gre_wccp_primary_bucket ,
{ " Primary Bucket " , " gre.wccp.primary_bucket " ,
FT_UINT8 , BASE_DEC , NULL , 0x0 ,
" Primary bucket index used to redirect the packet. " , HFILL }
} ,
} ;
static gint * ett [ ] = {
& ett_gre ,
& ett_gre_flags ,
& ett_gre_routing ,
& ett_gre_wccp2_redirect_header ,
& ett_3gpp2_attribs ,
& ett_3gpp2_attr ,
} ;
2013-05-26 03:29:07 +00:00
static ei_register_info ei [ ] = {
{ & ei_gre_checksum_incorrect , { " gre.checksum.incorrect " , PI_PROTOCOL , PI_WARN , " Incorrect GRE Checksum " , EXPFILL } } ,
} ;
expert_module_t * expert_gre ;
2012-05-17 14:35:11 +00:00
proto_gre = proto_register_protocol ( " Generic Routing Encapsulation " ,
" GRE " , " gre " ) ;
proto_register_field_array ( proto_gre , hf , array_length ( hf ) ) ;
proto_register_subtree_array ( ett , array_length ( ett ) ) ;
2013-05-26 03:29:07 +00:00
expert_gre = expert_register_protocol ( proto_gre ) ;
expert_register_field_array ( expert_gre , ei , array_length ( ei ) ) ;
2012-05-17 14:35:11 +00:00
/* subdissector code */
gre_dissector_table = register_dissector_table ( " gre.proto " ,
" GRE protocol type " , FT_UINT16 , BASE_HEX ) ;
1999-07-29 05:47:07 +00:00
}
2000-04-16 22:46:25 +00:00
void
proto_reg_handoff_gre ( void )
{
2012-05-17 14:35:11 +00:00
dissector_handle_t gre_handle ;
2001-12-03 04:00:26 +00:00
2012-05-17 14:35:11 +00:00
gre_handle = create_dissector_handle ( dissect_gre , proto_gre ) ;
dissector_add_uint ( " ip.proto " , IP_PROTO_GRE , gre_handle ) ;
data_handle = find_dissector ( " data " ) ;
2000-04-16 22:46:25 +00:00
}