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tcpdump/print-bgp.c
Francois-Xavier Le Bail c0335764f4 BGP: Use a macro for repeated identical sizeof() 
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2021-05-26 11:13:53 +02:00

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/*
* Copyright (C) 1999 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Extensively modified by Hannes Gredler (hannes@gredler.at) for more
* complete BGP support.
*/
/* \summary: Border Gateway Protocol (BGP) printer */
/* specification: RFC 4271 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include <stdio.h>
#include <string.h>
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#include "af.h"
#include "l2vpn.h"
struct bgp {
nd_byte bgp_marker[16];
nd_uint16_t bgp_len;
nd_uint8_t bgp_type;
};
#define BGP_SIZE 19 /* unaligned */
#define BGP_OPEN 1
#define BGP_UPDATE 2
#define BGP_NOTIFICATION 3
#define BGP_KEEPALIVE 4
#define BGP_ROUTE_REFRESH 5
static const struct tok bgp_msg_values[] = {
{ BGP_OPEN, "Open"},
{ BGP_UPDATE, "Update"},
{ BGP_NOTIFICATION, "Notification"},
{ BGP_KEEPALIVE, "Keepalive"},
{ BGP_ROUTE_REFRESH, "Route Refresh"},
{ 0, NULL}
};
struct bgp_open {
nd_byte bgpo_marker[16];
nd_uint16_t bgpo_len;
nd_uint8_t bgpo_type;
nd_uint8_t bgpo_version;
nd_uint16_t bgpo_myas;
nd_uint16_t bgpo_holdtime;
nd_uint32_t bgpo_id;
nd_uint8_t bgpo_optlen;
/* options should follow */
};
#define BGP_OPEN_SIZE 29 /* unaligned */
struct bgp_opt {
nd_uint8_t bgpopt_type;
nd_uint8_t bgpopt_len;
/* variable length */
};
#define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
#define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */
struct bgp_notification {
nd_byte bgpn_marker[16];
nd_uint16_t bgpn_len;
nd_uint8_t bgpn_type;
nd_uint8_t bgpn_major;
nd_uint8_t bgpn_minor;
};
#define BGP_NOTIFICATION_SIZE 21 /* unaligned */
struct bgp_route_refresh {
nd_byte bgp_marker[16];
nd_uint16_t len;
nd_uint8_t type; /* No padding after this; afi is, in fact, not aligned */
nd_uint16_t afi;
nd_uint8_t res;
nd_uint8_t safi;
};
#define BGP_ROUTE_REFRESH_SIZE 23
#define bgp_attr_lenlen(flags, p) \
(((flags) & 0x10) ? 2U : 1U)
#define bgp_attr_len(flags, p) \
(((flags) & 0x10) ? GET_BE_U_2(p) : GET_U_1(p))
#define BGPTYPE_ORIGIN 1
#define BGPTYPE_AS_PATH 2
#define BGPTYPE_NEXT_HOP 3
#define BGPTYPE_MULTI_EXIT_DISC 4
#define BGPTYPE_LOCAL_PREF 5
#define BGPTYPE_ATOMIC_AGGREGATE 6
#define BGPTYPE_AGGREGATOR 7
#define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
#define BGPTYPE_ORIGINATOR_ID 9 /* RFC4456 */
#define BGPTYPE_CLUSTER_LIST 10 /* RFC4456 */
#define BGPTYPE_DPA 11 /* deprecated, draft-ietf-idr-bgp-dpa */
#define BGPTYPE_ADVERTISERS 12 /* deprecated RFC1863 */
#define BGPTYPE_RCID_PATH 13 /* deprecated RFC1863 */
#define BGPTYPE_MP_REACH_NLRI 14 /* RFC4760 */
#define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC4760 */
#define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
#define BGPTYPE_AS4_PATH 17 /* RFC6793 */
#define BGPTYPE_AGGREGATOR4 18 /* RFC6793 */
#define BGPTYPE_PMSI_TUNNEL 22 /* RFC6514 */
#define BGPTYPE_TUNNEL_ENCAP 23 /* RFC5512 */
#define BGPTYPE_TRAFFIC_ENG 24 /* RFC5543 */
#define BGPTYPE_IPV6_EXTD_COMMUNITIES 25 /* RFC5701 */
#define BGPTYPE_AIGP 26 /* RFC7311 */
#define BGPTYPE_PE_DISTINGUISHER_LABEL 27 /* RFC6514 */
#define BGPTYPE_ENTROPY_LABEL 28 /* RFC6790 */
#define BGPTYPE_LARGE_COMMUNITY 32 /* draft-ietf-idr-large-community-05 */
#define BGPTYPE_ATTR_SET 128 /* RFC6368 */
#define BGP_MP_NLRI_MINSIZE 3 /* End of RIB Marker detection */
static const struct tok bgp_attr_values[] = {
{ BGPTYPE_ORIGIN, "Origin"},
{ BGPTYPE_AS_PATH, "AS Path"},
{ BGPTYPE_AS4_PATH, "AS4 Path"},
{ BGPTYPE_NEXT_HOP, "Next Hop"},
{ BGPTYPE_MULTI_EXIT_DISC, "Multi Exit Discriminator"},
{ BGPTYPE_LOCAL_PREF, "Local Preference"},
{ BGPTYPE_ATOMIC_AGGREGATE, "Atomic Aggregate"},
{ BGPTYPE_AGGREGATOR, "Aggregator"},
{ BGPTYPE_AGGREGATOR4, "Aggregator4"},
{ BGPTYPE_COMMUNITIES, "Community"},
{ BGPTYPE_ORIGINATOR_ID, "Originator ID"},
{ BGPTYPE_CLUSTER_LIST, "Cluster List"},
{ BGPTYPE_DPA, "DPA"},
{ BGPTYPE_ADVERTISERS, "Advertisers"},
{ BGPTYPE_RCID_PATH, "RCID Path / Cluster ID"},
{ BGPTYPE_MP_REACH_NLRI, "Multi-Protocol Reach NLRI"},
{ BGPTYPE_MP_UNREACH_NLRI, "Multi-Protocol Unreach NLRI"},
{ BGPTYPE_EXTD_COMMUNITIES, "Extended Community"},
{ BGPTYPE_PMSI_TUNNEL, "PMSI Tunnel"},
{ BGPTYPE_TUNNEL_ENCAP, "Tunnel Encapsulation"},
{ BGPTYPE_TRAFFIC_ENG, "Traffic Engineering"},
{ BGPTYPE_IPV6_EXTD_COMMUNITIES, "IPv6 Extended Community"},
{ BGPTYPE_AIGP, "Accumulated IGP Metric"},
{ BGPTYPE_PE_DISTINGUISHER_LABEL, "PE Distinguisher Label"},
{ BGPTYPE_ENTROPY_LABEL, "Entropy Label"},
{ BGPTYPE_LARGE_COMMUNITY, "Large Community"},
{ BGPTYPE_ATTR_SET, "Attribute Set"},
{ 255, "Reserved for development"},
{ 0, NULL}
};
#define BGP_AS_SET 1
#define BGP_AS_SEQUENCE 2
#define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */
#define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */
#define BGP_AS_SEG_TYPE_MIN BGP_AS_SET
#define BGP_AS_SEG_TYPE_MAX BGP_CONFED_AS_SET
static const struct tok bgp_as_path_segment_open_values[] = {
{ BGP_AS_SEQUENCE, ""},
{ BGP_AS_SET, "{ "},
{ BGP_CONFED_AS_SEQUENCE, "( "},
{ BGP_CONFED_AS_SET, "({ "},
{ 0, NULL}
};
static const struct tok bgp_as_path_segment_close_values[] = {
{ BGP_AS_SEQUENCE, ""},
{ BGP_AS_SET, "}"},
{ BGP_CONFED_AS_SEQUENCE, ")"},
{ BGP_CONFED_AS_SET, "})"},
{ 0, NULL}
};
#define BGP_OPT_AUTH 1
#define BGP_OPT_CAP 2
static const struct tok bgp_opt_values[] = {
{ BGP_OPT_AUTH, "Authentication Information"},
{ BGP_OPT_CAP, "Capabilities Advertisement"},
{ 0, NULL}
};
#define BGP_CAPCODE_MP 1 /* RFC2858 */
#define BGP_CAPCODE_RR 2 /* RFC2918 */
#define BGP_CAPCODE_ORF 3 /* RFC5291 */
#define BGP_CAPCODE_MR 4 /* RFC3107 */
#define BGP_CAPCODE_EXT_NH 5 /* RFC5549 */
#define BGP_CAPCODE_ML 8 /* RFC8277 */
#define BGP_CAPCODE_RESTART 64 /* RFC4724 */
#define BGP_CAPCODE_AS_NEW 65 /* RFC6793 */
#define BGP_CAPCODE_DYN_CAP 67 /* draft-ietf-idr-dynamic-cap */
#define BGP_CAPCODE_MULTISESS 68 /* draft-ietf-idr-bgp-multisession */
#define BGP_CAPCODE_ADD_PATH 69 /* RFC7911 */
#define BGP_CAPCODE_ENH_RR 70 /* draft-keyur-bgp-enhanced-route-refresh */
#define BGP_CAPCODE_LLGR 71 /* draft-uttaro-idr-bgp-persistence-05 */
#define BGP_CAPCODE_RR_CISCO 128
static const struct tok bgp_capcode_values[] = {
{ BGP_CAPCODE_MP, "Multiprotocol Extensions"},
{ BGP_CAPCODE_RR, "Route Refresh"},
{ BGP_CAPCODE_ORF, "Cooperative Route Filtering"},
{ BGP_CAPCODE_MR, "Multiple Routes to a Destination"},
{ BGP_CAPCODE_EXT_NH, "Extended Next Hop Encoding"},
{ BGP_CAPCODE_ML, "Multiple Labels"},
{ BGP_CAPCODE_RESTART, "Graceful Restart"},
{ BGP_CAPCODE_AS_NEW, "32-Bit AS Number"},
{ BGP_CAPCODE_DYN_CAP, "Dynamic Capability"},
{ BGP_CAPCODE_MULTISESS, "Multisession BGP"},
{ BGP_CAPCODE_ADD_PATH, "Multiple Paths"},
{ BGP_CAPCODE_ENH_RR, "Enhanced Route Refresh"},
{ BGP_CAPCODE_LLGR, "Long-lived Graceful Restart"},
{ BGP_CAPCODE_RR_CISCO, "Route Refresh (Cisco)"},
{ 0, NULL}
};
#define BGP_NOTIFY_MAJOR_MSG 1
#define BGP_NOTIFY_MAJOR_OPEN 2
#define BGP_NOTIFY_MAJOR_UPDATE 3
#define BGP_NOTIFY_MAJOR_HOLDTIME 4
#define BGP_NOTIFY_MAJOR_FSM 5
#define BGP_NOTIFY_MAJOR_CEASE 6
#define BGP_NOTIFY_MAJOR_CAP 7
static const struct tok bgp_notify_major_values[] = {
{ BGP_NOTIFY_MAJOR_MSG, "Message Header Error"},
{ BGP_NOTIFY_MAJOR_OPEN, "OPEN Message Error"},
{ BGP_NOTIFY_MAJOR_UPDATE, "UPDATE Message Error"},
{ BGP_NOTIFY_MAJOR_HOLDTIME,"Hold Timer Expired"},
{ BGP_NOTIFY_MAJOR_FSM, "Finite State Machine Error"},
{ BGP_NOTIFY_MAJOR_CEASE, "Cease"},
{ BGP_NOTIFY_MAJOR_CAP, "Capability Message Error"},
{ 0, NULL}
};
/* draft-ietf-idr-cease-subcode-02 */
#define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
/* draft-ietf-idr-shutdown-07 */
#define BGP_NOTIFY_MINOR_CEASE_SHUT 2
#define BGP_NOTIFY_MINOR_CEASE_RESET 4
#define BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN 128
static const struct tok bgp_notify_minor_cease_values[] = {
{ BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
{ BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
{ 3, "Peer Unconfigured"},
{ BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
{ 5, "Connection Rejected"},
{ 6, "Other Configuration Change"},
{ 7, "Connection Collision Resolution"},
{ 0, NULL}
};
static const struct tok bgp_notify_minor_msg_values[] = {
{ 1, "Connection Not Synchronized"},
{ 2, "Bad Message Length"},
{ 3, "Bad Message Type"},
{ 0, NULL}
};
static const struct tok bgp_notify_minor_open_values[] = {
{ 1, "Unsupported Version Number"},
{ 2, "Bad Peer AS"},
{ 3, "Bad BGP Identifier"},
{ 4, "Unsupported Optional Parameter"},
{ 5, "Authentication Failure"},
{ 6, "Unacceptable Hold Time"},
{ 7, "Capability Message Error"},
{ 0, NULL}
};
static const struct tok bgp_notify_minor_update_values[] = {
{ 1, "Malformed Attribute List"},
{ 2, "Unrecognized Well-known Attribute"},
{ 3, "Missing Well-known Attribute"},
{ 4, "Attribute Flags Error"},
{ 5, "Attribute Length Error"},
{ 6, "Invalid ORIGIN Attribute"},
{ 7, "AS Routing Loop"},
{ 8, "Invalid NEXT_HOP Attribute"},
{ 9, "Optional Attribute Error"},
{ 10, "Invalid Network Field"},
{ 11, "Malformed AS_PATH"},
{ 0, NULL}
};
static const struct tok bgp_notify_minor_fsm_values[] = {
{ 0, "Unspecified Error"},
{ 1, "In OpenSent State"},
{ 2, "In OpenConfirm State"},
{ 3, "In Established State"},
{ 0, NULL }
};
static const struct tok bgp_notify_minor_cap_values[] = {
{ 1, "Invalid Action Value" },
{ 2, "Invalid Capability Length" },
{ 3, "Malformed Capability Value" },
{ 4, "Unsupported Capability Code" },
{ 0, NULL }
};
static const struct tok bgp_origin_values[] = {
{ 0, "IGP"},
{ 1, "EGP"},
{ 2, "Incomplete"},
{ 0, NULL}
};
#define BGP_PMSI_TUNNEL_RSVP_P2MP 1
#define BGP_PMSI_TUNNEL_LDP_P2MP 2
#define BGP_PMSI_TUNNEL_PIM_SSM 3
#define BGP_PMSI_TUNNEL_PIM_SM 4
#define BGP_PMSI_TUNNEL_PIM_BIDIR 5
#define BGP_PMSI_TUNNEL_INGRESS 6
#define BGP_PMSI_TUNNEL_LDP_MP2MP 7
static const struct tok bgp_pmsi_tunnel_values[] = {
{ BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
{ BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
{ BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
{ BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
{ BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
{ BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
{ BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
{ 0, NULL}
};
static const struct tok bgp_pmsi_flag_values[] = {
{ 0x01, "Leaf Information required"},
{ 0, NULL}
};
#define BGP_AIGP_TLV 1
static const struct tok bgp_aigp_values[] = {
{ BGP_AIGP_TLV, "AIGP"},
{ 0, NULL}
};
/* Subsequent address family identifier, RFC2283 section 7 */
#define SAFNUM_RES 0
#define SAFNUM_UNICAST 1
#define SAFNUM_MULTICAST 2
#define SAFNUM_UNIMULTICAST 3 /* deprecated now */
/* labeled BGP RFC3107 */
#define SAFNUM_LABUNICAST 4
/* RFC6514 */
#define SAFNUM_MULTICAST_VPN 5
/* draft-nalawade-kapoor-tunnel-safi */
#define SAFNUM_TUNNEL 64
/* RFC4761 */
#define SAFNUM_VPLS 65
/* RFC6037 */
#define SAFNUM_MDT 66
/* RFC7432 */
#define SAFNUM_EVPN 70
/* RFC4364 */
#define SAFNUM_VPNUNICAST 128
/* RFC6513 */
#define SAFNUM_VPNMULTICAST 129
#define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
/* RFC4684 */
#define SAFNUM_RT_ROUTING_INFO 132
#define BGP_VPN_RD_LEN 8
static const struct tok bgp_safi_values[] = {
{ SAFNUM_RES, "Reserved"},
{ SAFNUM_UNICAST, "Unicast"},
{ SAFNUM_MULTICAST, "Multicast"},
{ SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
{ SAFNUM_LABUNICAST, "labeled Unicast"},
{ SAFNUM_TUNNEL, "Tunnel"},
{ SAFNUM_VPLS, "VPLS"},
{ SAFNUM_MDT, "MDT"},
{ SAFNUM_EVPN, "EVPN"},
{ SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
{ SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
{ SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
{ SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
{ SAFNUM_MULTICAST_VPN, "Multicast VPN"},
{ 0, NULL }
};
/* well-known community */
#define BGP_COMMUNITY_NO_EXPORT 0xffffff01
#define BGP_COMMUNITY_NO_ADVERT 0xffffff02
#define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
/* Extended community type - RFC 4360 */
#define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
#define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
#define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
#define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
#define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
#define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
#define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
/* rfc2547 bgp-mpls-vpns */
#define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
#define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
#define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
#define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
#define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
#define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
#define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
#define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
#define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
#define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
#define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
#define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
#define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
#define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
/* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
#define BGP_EXT_COM_EIGRP_GEN 0x8800
#define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
#define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
#define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
#define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
#define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
static const struct tok bgp_extd_comm_flag_values[] = {
{ 0x8000, "vendor-specific"},
{ 0x4000, "non-transitive"},
{ 0, NULL},
};
static const struct tok bgp_extd_comm_subtype_values[] = {
{ BGP_EXT_COM_RT_0, "target"},
{ BGP_EXT_COM_RT_1, "target"},
{ BGP_EXT_COM_RT_2, "target"},
{ BGP_EXT_COM_RO_0, "origin"},
{ BGP_EXT_COM_RO_1, "origin"},
{ BGP_EXT_COM_RO_2, "origin"},
{ BGP_EXT_COM_LINKBAND, "link-BW"},
{ BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
{ BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
{ BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
{ BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
{ BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
{ BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
{ BGP_EXT_COM_ENCAP, "encapsulation"},
{ BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
{ BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
{ BGP_EXT_COM_L2INFO, "layer2-info"},
{ BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
{ BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
{ BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
{ BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
{ BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
{ BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
{ BGP_EXT_COM_SOURCE_AS, "source-AS" },
{ BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
{ BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
{ BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
{ 0, NULL},
};
/* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
#define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
#define BGP_ENCAP_TUNNEL_GRE 2
#define BGP_ENCAP_TUNNEL_TRANSMIT 3
#define BGP_ENCAP_TUNNEL_IPSEC 4
#define BGP_ENCAP_TUNNEL_IP_IPSEC 5
#define BGP_ENCAP_TUNNEL_MPLS_IP 6
#define BGP_ENCAP_TUNNEL_IP_IP 7
#define BGP_ENCAP_TUNNEL_VXLAN 8
#define BGP_ENCAP_TUNNEL_NVGRE 9
#define BGP_ENCAP_TUNNEL_MPLS 10
#define BGP_ENCAP_TUNNEL_MPLS_GRE 11
#define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
#define BGP_ENCAP_TUNNEL_MPLS_UDP 13
#define BGP_ENCAP_TUNNEL_IPV6 14
#define BGP_ENCAP_TUNNEL_SR_TE 15
#define BGP_ENCAP_TUNNEL_BARE 16
#define BGP_ENCAP_TUNNEL_SR 17
static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
{ BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
{ BGP_ENCAP_TUNNEL_GRE, "GRE"},
{ BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
{ BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
{ BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
{ BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
{ BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
{ BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
{ BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
{ BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
{ BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
{ BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
{ BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
{ BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
{ BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
{ BGP_ENCAP_TUNNEL_BARE, "Bare"},
{ BGP_ENCAP_TUNNEL_SR, "SR"},
{ 0, NULL},
};
/* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
#define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
#define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
#define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
#define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
#define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
#define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
#define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
{ BGP_OSPF_RTYPE_RTR, "Router" },
{ BGP_OSPF_RTYPE_NET, "Network" },
{ BGP_OSPF_RTYPE_SUM, "Summary" },
{ BGP_OSPF_RTYPE_EXT, "External" },
{ BGP_OSPF_RTYPE_NSSA,"NSSA External" },
{ BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
{ 0, NULL },
};
/* ADD-PATH Send/Receive field values */
static const struct tok bgp_add_path_recvsend[] = {
{ 1, "Receive" },
{ 2, "Send" },
{ 3, "Both" },
{ 0, NULL },
};
#define AS_STR_SIZE sizeof("xxxxx.xxxxx")
/*
* as_printf
*
* Convert an AS number into a string and return string pointer.
*
* Depending on bflag is set or not, AS number is converted into ASDOT notation
* or plain number notation.
*
*/
static char *
as_printf(netdissect_options *ndo,
char *str, size_t size, u_int asnum)
{
if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
snprintf(str, size, "%u", asnum);
} else {
snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
}
return str;
}
#define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
int
decode_prefix4(netdissect_options *ndo,
const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
{
nd_ipv4 addr;
u_int plen, plenbytes;
ITEMCHECK(1);
plen = GET_U_1(pptr);
if (32 < plen)
return -1;
itemlen -= 1;
memset(&addr, 0, sizeof(addr));
plenbytes = (plen + 7) / 8;
ITEMCHECK(plenbytes);
GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
if (plen % 8) {
((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
}
snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
return 1 + plenbytes;
badtlv:
return -2;
}
static int
decode_labeled_prefix4(netdissect_options *ndo,
const u_char *pptr, u_int itemlen, char *buf,
size_t buflen)
{
nd_ipv4 addr;
u_int plen, plenbytes;
/* prefix length and label = 4 bytes */
ND_TCHECK_4(pptr);
ITEMCHECK(4);
plen = GET_U_1(pptr); /* get prefix length */
/* this is one of the weirdnesses of rfc3107
the label length (actually the label + COS bits)
is added to the prefix length;
we also do only read out just one label -
there is no real application for advertisement of
stacked labels in a single BGP message
*/
if (24 > plen)
return -1;
plen-=24; /* adjust prefixlen - labellength */
if (32 < plen)
return -1;
itemlen -= 4;
memset(&addr, 0, sizeof(addr));
plenbytes = (plen + 7) / 8;
ITEMCHECK(plenbytes);
GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
if (plen % 8) {
((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
}
/* the label may get offsetted by 4 bits so lets shift it right */
snprintf(buf, buflen, "%s/%u, label:%u %s",
ipaddr_string(ndo, (const u_char *)&addr),
plen,
GET_BE_U_3(pptr + 1)>>4,
((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
return 4 + plenbytes;
trunc:
return -2;
badtlv:
return -3;
}
/*
* bgp_vpn_ip_print
*
* print an ipv4 or ipv6 address into a buffer dependent on address length.
*/
static char *
bgp_vpn_ip_print(netdissect_options *ndo,
const u_char *pptr, u_int addr_length)
{
/* worst case string is s fully formatted v6 address */
static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
char *pos = addr;
switch(addr_length) {
case (sizeof(nd_ipv4) << 3): /* 32 */
snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
break;
case (sizeof(nd_ipv6) << 3): /* 128 */
snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
break;
default:
snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
break;
}
pos += strlen(pos);
*(pos) = '\0';
return (addr);
}
/*
* bgp_vpn_sg_print
*
* print an multicast s,g entry into a buffer.
* the s,g entry is encoded like this.
*
* +-----------------------------------+
* | Multicast Source Length (1 octet) |
* +-----------------------------------+
* | Multicast Source (Variable) |
* +-----------------------------------+
* | Multicast Group Length (1 octet) |
* +-----------------------------------+
* | Multicast Group (Variable) |
* +-----------------------------------+
*
* return the number of bytes read from the wire.
*/
static u_int
bgp_vpn_sg_print(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
uint8_t addr_length;
u_int total_length, offset;
total_length = 0;
/* Source address length, encoded in bits */
addr_length = GET_U_1(pptr);
pptr++;
/* Source address */
ND_TCHECK_LEN(pptr, (addr_length >> 3));
total_length += (addr_length >> 3) + 1;
offset = (u_int)strlen(buf);
if (addr_length) {
snprintf(buf + offset, buflen - offset, ", Source %s",
bgp_vpn_ip_print(ndo, pptr, addr_length));
pptr += (addr_length >> 3);
}
/* Group address length, encoded in bits */
addr_length = GET_U_1(pptr);
pptr++;
/* Group address */
ND_TCHECK_LEN(pptr, (addr_length >> 3));
total_length += (addr_length >> 3) + 1;
offset = (u_int)strlen(buf);
if (addr_length) {
snprintf(buf + offset, buflen - offset, ", Group %s",
bgp_vpn_ip_print(ndo, pptr, addr_length));
pptr += (addr_length >> 3);
}
trunc:
return (total_length);
}
/* Print an RFC 4364 Route Distinguisher */
const char *
bgp_vpn_rd_print(netdissect_options *ndo,
const u_char *pptr)
{
/* allocate space for the largest possible string */
static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
char *pos = rd;
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
/* ok lets load the RD format */
switch (GET_BE_U_2(pptr)) {
case 0:
/* 2-byte-AS:number fmt */
snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
GET_BE_U_2(pptr + 2),
GET_BE_U_4(pptr + 4),
GET_U_1(pptr + 4), GET_U_1(pptr + 5),
GET_U_1(pptr + 6), GET_U_1(pptr + 7));
break;
case 1:
/* IP-address:AS fmt */
snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
GET_U_1(pptr + 2), GET_U_1(pptr + 3),
GET_U_1(pptr + 4), GET_U_1(pptr + 5),
GET_BE_U_2(pptr + 6));
break;
case 2:
/* 4-byte-AS:number fmt */
snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
GET_U_1(pptr + 3), GET_U_1(pptr + 4),
GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
break;
default:
snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
break;
}
pos += strlen(pos);
*(pos) = '\0';
return (rd);
}
/*
* Print an RFC 4360 Extended Community.
*/
static void
bgp_extended_community_print(netdissect_options *ndo,
const u_char *pptr)
{
union { /* copy buffer for bandwidth values */
float f;
uint32_t i;
} bw;
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
switch (GET_BE_U_2(pptr)) {
case BGP_EXT_COM_RT_0:
case BGP_EXT_COM_RO_0:
case BGP_EXT_COM_L2VPN_RT_0:
ND_PRINT("%u:%u (= %s)",
GET_BE_U_2(pptr + 2),
GET_BE_U_4(pptr + 4),
GET_IPADDR_STRING(pptr+4));
break;
case BGP_EXT_COM_RT_1:
case BGP_EXT_COM_RO_1:
case BGP_EXT_COM_L2VPN_RT_1:
case BGP_EXT_COM_VRF_RT_IMP:
ND_PRINT("%s:%u",
GET_IPADDR_STRING(pptr+2),
GET_BE_U_2(pptr + 6));
break;
case BGP_EXT_COM_RT_2:
case BGP_EXT_COM_RO_2:
ND_PRINT("%s:%u",
as_printf(ndo, astostr, sizeof(astostr),
GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
break;
case BGP_EXT_COM_LINKBAND:
bw.i = GET_BE_U_4(pptr + 2);
ND_PRINT("bandwidth: %.3f Mbps",
bw.f*8/1000000);
break;
case BGP_EXT_COM_VPN_ORIGIN:
case BGP_EXT_COM_VPN_ORIGIN2:
case BGP_EXT_COM_VPN_ORIGIN3:
case BGP_EXT_COM_VPN_ORIGIN4:
case BGP_EXT_COM_OSPF_RID:
case BGP_EXT_COM_OSPF_RID2:
ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
break;
case BGP_EXT_COM_OSPF_RTYPE:
case BGP_EXT_COM_OSPF_RTYPE2:
ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
GET_IPADDR_STRING(pptr+2),
tok2str(bgp_extd_comm_ospf_rtype_values,
"unknown (0x%02x)",
GET_U_1((pptr + 6))),
(GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
break;
case BGP_EXT_COM_L2INFO:
ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
tok2str(l2vpn_encaps_values,
"unknown encaps",
GET_U_1((pptr + 2))),
GET_U_1((pptr + 3)),
GET_BE_U_2(pptr + 4));
break;
case BGP_EXT_COM_SOURCE_AS:
ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
break;
case BGP_EXT_COM_ENCAP:
ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
"unknown encaps",
GET_BE_U_2(pptr + 6)));
break;
default:
ND_PRINT("%02x%02x%02x%02x%02x%02x",
GET_U_1(pptr + 2),
GET_U_1(pptr + 3),
GET_U_1(pptr + 4),
GET_U_1(pptr + 5),
GET_U_1(pptr + 6),
GET_U_1(pptr + 7));
break;
}
}
/*
* RFC4684 (Section 4)/RFC2858 (Section 4).
* RTC membership prefix is structured as follows
* [prefix-len] [origin-as] [route-target]
* The route-target is encoded as RT ext-comms.
* Prefix-len may be 0, 32..96
*
* Note that pptr is not packet data - it is
* a buffer owned by our caller - therefore GET_*
* macros can not be used.
*/
static char *
bgp_rt_prefix_print(netdissect_options *ndo,
const u_char *pptr,
u_int plen)
{
/* allocate space for the largest possible string */
char rtc_prefix_in_hex[20] = "";
u_int rtc_prefix_in_hex_len = 0;
static char output[61]; /* max response string */
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
uint16_t ec_type = 0;
u_int octet_count;
u_int i;
if (plen == 0) {
snprintf(output, sizeof(output), "route-target: 0:0/0");
return (output);
}
/* hex representation of the prefix */
octet_count = (plen+7)/8;
for (i=0; i<octet_count; i++) {
rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
"%02x%s", *(pptr+i),
((i%2 == 1) && (i<octet_count-1)) ? " " : "");
}
if (plen < 16) {
/*
* The prefix is too short to include the full ext-comm type,
* so we have no way to parse it further.
*/
snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
rtc_prefix_in_hex, plen);
return (output);
}
/*
* get the ext-comm type
* Note: pptr references a static 8 octet buffer with unused bits set to 0,
* hense EXTRACT_*() macros are safe.
*/
ec_type = EXTRACT_BE_U_2(pptr);
switch (ec_type) {
case BGP_EXT_COM_RT_0:
/* 2-byte-AS:number fmt */
snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
EXTRACT_BE_U_2(pptr+2),
EXTRACT_BE_U_4(pptr+4),
plen, rtc_prefix_in_hex);
break;
case BGP_EXT_COM_RT_1:
/* IP-address:AS fmt */
snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
*(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
break;
case BGP_EXT_COM_RT_2:
/* 4-byte-AS:number fmt */
snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
break;
default:
snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
ec_type,
rtc_prefix_in_hex, plen);
break;
}
return (output);
}
/* RFC 4684 */
static int
decode_rt_routing_info(netdissect_options *ndo,
const u_char *pptr)
{
uint8_t route_target[8];
u_int plen;
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
u_int num_octets;
/* NLRI "prefix length" from RFC 2858 Section 4. */
plen = GET_U_1(pptr); /* get prefix length */
/* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
* RFC 4684 Section 4 defines the layout of "origin AS" and "route
* target" fields inside the "prefix" depending on its length.
*/
if (0 == plen) {
/* Without "origin AS", without "route target". */
ND_PRINT("\n\t default route target");
return 1;
}
if (32 > plen) {
ND_PRINT("\n\t (illegal prefix length)");
return -1;
}
/* With at least "origin AS", possibly with "route target". */
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
plen -= 32; /* adjust prefix length */
if (64 < plen) {
ND_PRINT("\n\t (illegal prefix length)");
return -1;
}
/* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
* and gives the number of octets in the variable-length "route
* target" field inside this NLRI "prefix". Look for it.
*/
memset(&route_target, 0, sizeof(route_target));
num_octets = (plen + 7) / 8;
GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
/* If mask-len is not on octet boundary, ensure all extra bits are 0 */
if (plen % 8) {
((u_char *)&route_target)[num_octets - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
ND_PRINT("\n\t origin AS: %s, %s",
astostr,
bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
return 5 + num_octets;
}
static int
decode_labeled_vpn_prefix4(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
nd_ipv4 addr;
u_int plen;
plen = GET_U_1(pptr); /* get prefix length */
if ((24+64) > plen)
return -1;
plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
if (32 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
if (plen % 8) {
((u_char *)&addr)[(plen + 7) / 8 - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
/* the label may get offsetted by 4 bits so lets shift it right */
snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
bgp_vpn_rd_print(ndo, pptr+4),
ipaddr_string(ndo, (const u_char *)&addr),
plen,
GET_BE_U_3(pptr + 1)>>4,
((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
return 12 + (plen + 7) / 8;
}
/*
* +-------------------------------+
* | |
* | RD:IPv4-address (12 octets) |
* | |
* +-------------------------------+
* | MDT Group-address (4 octets) |
* +-------------------------------+
*/
#define MDT_VPN_NLRI_LEN 16
static int
decode_mdt_vpn_nlri(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
const u_char *rd;
const u_char *vpn_ip;
/* if the NLRI is not predefined length, quit.*/
if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
return -1;
pptr++;
/* RD */
ND_TCHECK_8(pptr);
rd = pptr;
pptr += 8;
/* IPv4 address */
vpn_ip = pptr;
pptr += sizeof(nd_ipv4);
/* MDT Group Address */
snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
return MDT_VPN_NLRI_LEN + 1;
trunc:
return -2;
}
#define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
#define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
#define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
#define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
#define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
#define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
#define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
static const struct tok bgp_multicast_vpn_route_type_values[] = {
{ BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
{ BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
{ 0, NULL}
};
static int
decode_multicast_vpn(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
uint8_t route_type, route_length;
u_int addr_length, sg_length;
u_int offset;
route_type = GET_U_1(pptr);
pptr++;
route_length = GET_U_1(pptr);
pptr++;
snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
tok2str(bgp_multicast_vpn_route_type_values,
"Unknown", route_type),
route_type, route_length);
switch(route_type) {
case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
bgp_vpn_rd_print(ndo, pptr),
bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
(route_length - BGP_VPN_RD_LEN) << 3));
break;
case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
bgp_vpn_rd_print(ndo, pptr),
as_printf(ndo, astostr, sizeof(astostr),
GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
break;
case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", RD: %s",
bgp_vpn_rd_print(ndo, pptr));
pptr += BGP_VPN_RD_LEN;
sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
addr_length = route_length - sg_length;
ND_TCHECK_LEN(pptr, addr_length);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", Originator %s",
bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
break;
case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", RD: %s",
bgp_vpn_rd_print(ndo, pptr));
pptr += BGP_VPN_RD_LEN;
bgp_vpn_sg_print(ndo, pptr, buf, buflen);
break;
case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
offset = (u_int)strlen(buf);
snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
bgp_vpn_rd_print(ndo, pptr),
as_printf(ndo, astostr, sizeof(astostr),
GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
pptr += BGP_VPN_RD_LEN + 4;
bgp_vpn_sg_print(ndo, pptr, buf, buflen);
break;
/*
* no per route-type printing yet.
*/
case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
default:
break;
}
return route_length + 2;
trunc:
return -2;
}
/*
* As I remember, some versions of systems have an snprintf() that
* returns -1 if the buffer would have overflowed. If the return
* value is negative, set buflen to 0, to indicate that we've filled
* the buffer up.
*
* If the return value is greater than buflen, that means that
* the buffer would have overflowed; again, set buflen to 0 in
* that case.
*/
#define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
if (stringlen<0) \
buflen=0; \
else if ((u_int)stringlen>buflen) \
buflen=0; \
else { \
buflen-=stringlen; \
buf+=stringlen; \
}
static int
decode_labeled_vpn_l2(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
int stringlen;
plen = GET_BE_U_2(pptr);
tlen = plen;
pptr += 2;
/* Old and new L2VPN NLRI share AFI/SAFI
* -> Assume a 12 Byte-length NLRI is auto-discovery-only
* and > 17 as old format. Complain for the middle case
*/
if (plen == 12) {
/* assume AD-only with RD, BGPNH */
ND_TCHECK_LEN(pptr, 12);
buf[0] = '\0';
stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
bgp_vpn_rd_print(ndo, pptr),
GET_IPADDR_STRING(pptr+8));
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
pptr += 12;
tlen -= 12;
return plen + 2;
} else if (plen > 17) {
/* assume old format */
/* RD, ID, LBLKOFF, LBLBASE */
ND_TCHECK_LEN(pptr, 15);
buf[0] = '\0';
stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
bgp_vpn_rd_print(ndo, pptr),
GET_BE_U_2(pptr + 8),
GET_BE_U_2(pptr + 10),
GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
pptr += 15;
tlen -= 15;
/* ok now the variable part - lets read out TLVs*/
while (tlen != 0) {
if (tlen < 3) {
if (buflen != 0) {
stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
return plen + 2;
}
tlv_type = GET_U_1(pptr);
pptr++;
tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
pptr += 2;
switch(tlv_type) {
case 1:
if (buflen != 0) {
stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
tlv_type,
tlv_len);
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
while (ttlv_len != 0) {
if (tlen < 1) {
if (buflen != 0) {
stringlen=snprintf(buf,buflen, " (ran past the end)");
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
return plen + 2;
}
ND_TCHECK_1(pptr);
if (buflen != 0) {
stringlen=snprintf(buf,buflen, "%02x",
GET_U_1(pptr));
pptr++;
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
ttlv_len--;
tlen--;
}
break;
default:
if (buflen != 0) {
stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
tlv_type,
tlv_len);
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
if (tlen < ttlv_len) {
if (buflen != 0) {
stringlen=snprintf(buf,buflen, " (ran past the end)");
UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
}
return plen + 2;
}
tlen -= ttlv_len;
break;
}
}
return plen + 2;
} else {
/* complain bitterly ? */
/* fall through */
goto trunc;
}
trunc:
return -2;
}
int
decode_prefix6(netdissect_options *ndo,
const u_char *pd, u_int itemlen, char *buf, size_t buflen)
{
nd_ipv6 addr;
u_int plen, plenbytes;
ITEMCHECK(1);
plen = GET_U_1(pd);
if (128 < plen)
return -1;
itemlen -= 1;
memset(&addr, 0, sizeof(addr));
plenbytes = (plen + 7) / 8;
ITEMCHECK(plenbytes);
GET_CPY_BYTES(&addr, pd + 1, plenbytes);
if (plen % 8) {
addr[plenbytes - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
return 1 + plenbytes;
badtlv:
return -2;
}
static int
decode_labeled_prefix6(netdissect_options *ndo,
const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
{
nd_ipv6 addr;
u_int plen, plenbytes;
/* prefix length and label = 4 bytes */
ND_TCHECK_4(pptr);
ITEMCHECK(4);
plen = GET_U_1(pptr); /* get prefix length */
if (24 > plen)
return -1;
plen -= 24; /* adjust prefixlen - labellength */
if (128 < plen)
return -1;
itemlen -= 4;
memset(&addr, 0, sizeof(addr));
plenbytes = (plen + 7) / 8;
GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
if (plen % 8) {
addr[plenbytes - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
/* the label may get offsetted by 4 bits so lets shift it right */
snprintf(buf, buflen, "%s/%u, label:%u %s",
ip6addr_string(ndo, (const u_char *)&addr),
plen,
GET_BE_U_3(pptr + 1)>>4,
((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
return 4 + plenbytes;
trunc:
return -2;
badtlv:
return -3;
}
static int
decode_labeled_vpn_prefix6(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
nd_ipv6 addr;
u_int plen;
plen = GET_U_1(pptr); /* get prefix length */
if ((24+64) > plen)
return -1;
plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
if (128 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
if (plen % 8) {
addr[(plen + 7) / 8 - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
/* the label may get offsetted by 4 bits so lets shift it right */
snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
bgp_vpn_rd_print(ndo, pptr+4),
ip6addr_string(ndo, (const u_char *)&addr),
plen,
GET_BE_U_3(pptr + 1)>>4,
((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
return 12 + (plen + 7) / 8;
}
static int
decode_clnp_prefix(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
uint8_t addr[19];
u_int plen;
plen = GET_U_1(pptr); /* get prefix length */
if (152 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
GET_CPY_BYTES(&addr, pptr + 4, (plen + 7) / 8);
if (plen % 8) {
addr[(plen + 7) / 8 - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
/* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
snprintf(buf, buflen, "%s/%u",
isonsap_string(ndo, addr,(plen + 7) / 8),
plen);
return 1 + (plen + 7) / 8;
}
static int
decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
const u_char *pptr, char *buf, size_t buflen)
{
uint8_t addr[19];
u_int plen;
plen = GET_U_1(pptr); /* get prefix length */
if ((24+64) > plen)
return -1;
plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
if (152 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
if (plen % 8) {
addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
}
/* the label may get offsetted by 4 bits so lets shift it right */
/* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
bgp_vpn_rd_print(ndo, pptr+4),
isonsap_string(ndo, addr,(plen + 7) / 8),
plen,
GET_BE_U_3(pptr + 1)>>4,
((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
return 12 + (plen + 7) / 8;
}
/*
* bgp_attr_get_as_size
*
* Try to find the size of the ASs encoded in an as-path. It is not obvious, as
* both Old speakers that do not support 4 byte AS, and the new speakers that do
* support, exchange AS-Path with the same path-attribute type value 0x02.
*/
static u_int
bgp_attr_get_as_size(netdissect_options *ndo,
uint8_t bgpa_type, const u_char *pptr, u_int len)
{
const u_char *tptr = pptr;
/*
* If the path attribute is the optional AS4 path type, then we already
* know, that ASs must be encoded in 4 byte format.
*/
if (bgpa_type == BGPTYPE_AS4_PATH) {
return 4;
}
/*
* Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
* TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
* each.
*/
while (tptr < pptr + len) {
/*
* If we do not find a valid segment type, our guess might be wrong.
*/
if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
goto trunc;
}
tptr += 2 + GET_U_1(tptr + 1) * 2;
}
/*
* If we correctly reached end of the AS path attribute data content,
* then most likely ASs were indeed encoded as 2 bytes.
*/
if (tptr == pptr + len) {
return 2;
}
trunc:
/*
* We can come here, either we did not have enough data, or if we
* try to decode 4 byte ASs in 2 byte format. Either way, return 4,
* so that calller can try to decode each AS as of 4 bytes. If indeed
* there was not enough data, it will crib and end the parse anyways.
*/
return 4;
}
/*
* The only way to know that a BGP UPDATE message is using add path is
* by checking if the capability is in the OPEN message which we may have missed.
* So this function checks if it is possible that the update could contain add path
* and if so it checks that standard BGP doesn't make sense.
*/
static int
check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
u_int max_prefix_length)
{
u_int offset, prefix_length;
if (length < 5) {
return 0;
}
/*
* Scan through the NLRI information under the assumpetion that
* it doesn't have path IDs.
*/
for (offset = 0; offset < length;) {
offset += 4;
if (!ND_TTEST_1(pptr + offset)) {
/* We ran out of captured data; quit scanning. */
break;
}
prefix_length = GET_U_1(pptr + offset);
/*
* Add 4 to cover the path id
* and check the prefix length isn't greater than 32/128.
*/
if (prefix_length > max_prefix_length) {
return 0;
}
/* Add 1 for the prefix_length byte and prefix_length to cover the address */
offset += 1 + ((prefix_length + 7) / 8);
}
/* check we haven't gone past the end of the section */
if (offset > length) {
return 0;
}
/* check it's not standard BGP */
for (offset = 0; offset < length; ) {
if (!ND_TTEST_1(pptr + offset)) {
/* We ran out of captured data; quit scanning. */
break;
}
prefix_length = GET_U_1(pptr + offset);
/*
* If the prefix_length is zero (0.0.0.0/0)
* and since it's not the only address (length >= 5)
* then it is add-path
*/
if (prefix_length < 1 || prefix_length > max_prefix_length) {
return 1;
}
offset += 1 + ((prefix_length + 7) / 8);
}
if (offset > length) {
return 1;
}
/* assume not add-path by default */
return 0;
}
static int
bgp_mp_af_print(netdissect_options *ndo,
const u_char *tptr, u_int tlen,
uint16_t *afp, uint8_t *safip)
{
uint16_t af;
uint8_t safi;
af = GET_BE_U_2(tptr);
*afp = af;
safi = GET_U_1(tptr + 2);
*safip = safi;
ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
tok2str(af_values, "Unknown AFI", af),
af,
(safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
tok2str(bgp_safi_values, "Unknown SAFI", safi),
safi);
switch(af<<8 | safi) {
case (AFNUM_INET<<8 | SAFNUM_UNICAST):
case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
case (AFNUM_INET<<8 | SAFNUM_MDT):
case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
break;
default:
ND_TCHECK_LEN(tptr, tlen);
ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
if (ndo->ndo_vflag <= 1)
print_unknown_data(ndo, tptr, "\n\t ", tlen);
return -1;
}
return 0;
trunc:
return -2;
}
static int
bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
const u_char *tptr, u_int len,
char *buf, size_t buflen,
int add_path4, int add_path6)
{
int advance;
u_int path_id = 0;
switch (af<<8 | safi) {
case (AFNUM_INET<<8 | SAFNUM_UNICAST):
case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
if (add_path4) {
path_id = GET_BE_U_4(tptr);
tptr += 4;
}
advance = decode_prefix4(ndo, tptr, len, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
break; /* bytes left, but not enough */
else
ND_PRINT("\n\t %s", buf);
if (add_path4) {
ND_PRINT(" Path Id: %u", path_id);
advance += 4;
}
break;
case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
goto trunc;
else if (advance == -3)
break; /* bytes left, but not enough */
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
advance = decode_rt_routing_info(ndo, tptr);
break;
case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
goto trunc;
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_INET<<8 | SAFNUM_MDT):
advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
goto trunc;
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
if (add_path6) {
path_id = GET_BE_U_4(tptr);
tptr += 4;
}
advance = decode_prefix6(ndo, tptr, len, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
break; /* bytes left, but not enough */
else
ND_PRINT("\n\t %s", buf);
if (add_path6) {
ND_PRINT(" Path Id: %u", path_id);
advance += 4;
}
break;
case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else if (advance == -2)
goto trunc;
else if (advance == -3)
break; /* bytes left, but not enough */
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal length)");
else if (advance == -2)
goto trunc;
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else
ND_PRINT("\n\t %s", buf);
break;
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
if (advance == -1)
ND_PRINT("\n\t (illegal prefix length)");
else
ND_PRINT("\n\t %s", buf);
break;
default:
/*
* This should not happen, we should have been protected
* by bgp_mp_af_print()'s return value.
*/
ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
advance = -4;
break;
}
return advance;
trunc: /* we rely on the caller to recognize -2 return value */
return -2;
}
static int
bgp_attr_print(netdissect_options *ndo,
uint8_t atype, const u_char *pptr, u_int len,
const unsigned attr_set_level)
{
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
u_int i;
uint16_t af;
uint8_t safi, snpa, nhlen;
int advance;
u_int tlen;
const u_char *tptr;
char buf[MAXHOSTNAMELEN + 100];
u_int as_size;
int add_path4, add_path6;
int ret;
tptr = pptr;
tlen = len;
switch (atype) {
case BGPTYPE_ORIGIN:
if (len != 1)
ND_PRINT("invalid len");
else {
ND_PRINT("%s", tok2str(bgp_origin_values,
"Unknown Origin Typecode",
GET_U_1(tptr)));
}
break;
/*
* Process AS4 byte path and AS2 byte path attributes here.
*/
case BGPTYPE_AS4_PATH:
case BGPTYPE_AS_PATH:
if (len % 2) {
ND_PRINT("invalid len");
break;
}
if (!len) {
ND_PRINT("empty");
break;
}
/*
* BGP updates exchanged between New speakers that support 4
* byte AS, ASs are always encoded in 4 bytes. There is no
* definitive way to find this, just by the packet's
* contents. So, check for packet's TLV's sanity assuming
* 2 bytes first, and it does not pass, assume that ASs are
* encoded in 4 bytes format and move on.
*/
as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
while (tptr < pptr + len) {
ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
"?", GET_U_1(tptr)));
for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
ND_TCHECK_LEN(tptr + 2 + i, as_size);
ND_PRINT("%s ",
as_printf(ndo, astostr, sizeof(astostr),
as_size == 2 ?
GET_BE_U_2(tptr + i + 2) :
GET_BE_U_4(tptr + i + 2)));
}
ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
"?", GET_U_1(tptr)));
tptr += 2 + GET_U_1(tptr + 1) * as_size;
}
break;
case BGPTYPE_NEXT_HOP:
if (len != 4)
ND_PRINT("invalid len");
else {
ND_PRINT("%s", GET_IPADDR_STRING(tptr));
}
break;
case BGPTYPE_MULTI_EXIT_DISC:
case BGPTYPE_LOCAL_PREF:
if (len != 4)
ND_PRINT("invalid len");
else {
ND_PRINT("%u", GET_BE_U_4(tptr));
}
break;
case BGPTYPE_ATOMIC_AGGREGATE:
if (len != 0)
ND_PRINT("invalid len");
break;
case BGPTYPE_AGGREGATOR:
/*
* Depending on the AS encoded is of 2 bytes or of 4 bytes,
* the length of this PA can be either 6 bytes or 8 bytes.
*/
if (len != 6 && len != 8) {
ND_PRINT("invalid len");
break;
}
ND_TCHECK_LEN(tptr, len);
if (len == 6) {
ND_PRINT(" AS #%s, origin %s",
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
GET_IPADDR_STRING(tptr + 2));
} else {
ND_PRINT(" AS #%s, origin %s",
as_printf(ndo, astostr, sizeof(astostr),
GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
}
break;
case BGPTYPE_AGGREGATOR4:
if (len != 8) {
ND_PRINT("invalid len");
break;
}
ND_PRINT(" AS #%s, origin %s",
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
GET_IPADDR_STRING(tptr + 4));
break;
case BGPTYPE_COMMUNITIES:
if (len % 4) {
ND_PRINT("invalid len");
break;
}
while (tlen != 0) {
uint32_t comm;
ND_TCHECK_4(tptr);
if (tlen < 4)
goto trunc;
comm = GET_BE_U_4(tptr);
switch (comm) {
case BGP_COMMUNITY_NO_EXPORT:
ND_PRINT(" NO_EXPORT");
break;
case BGP_COMMUNITY_NO_ADVERT:
ND_PRINT(" NO_ADVERTISE");
break;
case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
ND_PRINT(" NO_EXPORT_SUBCONFED");
break;
default:
ND_PRINT("%u:%u%s",
(comm >> 16) & 0xffff,
comm & 0xffff,
(tlen>4) ? ", " : "");
break;
}
tlen -=4;
tptr +=4;
}
break;
case BGPTYPE_ORIGINATOR_ID:
if (len != 4) {
ND_PRINT("invalid len");
break;
}
ND_PRINT("%s",GET_IPADDR_STRING(tptr));
break;
case BGPTYPE_CLUSTER_LIST:
if (len % 4) {
ND_PRINT("invalid len");
break;
}
while (tlen != 0) {
if (tlen < 4)
goto trunc;
ND_PRINT("%s%s",
GET_IPADDR_STRING(tptr),
(tlen>4) ? ", " : "");
tlen -=4;
tptr +=4;
}
break;
case BGPTYPE_MP_REACH_NLRI:
ND_TCHECK_3(tptr);
if (tlen < 3)
goto trunc;
ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
if (ret == -2)
goto trunc;
if (ret < 0)
break;
tptr += 3;
tlen -= 3;
ND_TCHECK_1(tptr);
if (tlen < 1)
goto trunc;
nhlen = GET_U_1(tptr);
tptr++;
tlen--;
if (nhlen) {
u_int nnh = 0;
uint8_t tnhlen = nhlen;
if (tlen < tnhlen)
goto trunc;
ND_PRINT("\n\t nexthop: ");
while (tnhlen != 0) {
if (nnh++ > 0) {
ND_PRINT(", " );
}
switch(af<<8 | safi) {
case (AFNUM_INET<<8 | SAFNUM_UNICAST):
case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
case (AFNUM_INET<<8 | SAFNUM_MDT):
if (tnhlen < sizeof(nd_ipv4)) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_PRINT("%s",GET_IPADDR_STRING(tptr));
tptr += sizeof(nd_ipv4);
tnhlen -= sizeof(nd_ipv4);
tlen -= sizeof(nd_ipv4);
}
break;
case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_PRINT("RD: %s, %s",
bgp_vpn_rd_print(ndo, tptr),
GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
}
break;
case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
if (tnhlen < sizeof(nd_ipv6)) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
tptr += sizeof(nd_ipv6);
tlen -= sizeof(nd_ipv6);
tnhlen -= sizeof(nd_ipv6);
}
break;
case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_PRINT("RD: %s, %s",
bgp_vpn_rd_print(ndo, tptr),
GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
}
break;
case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
if (tnhlen < sizeof(nd_ipv4)) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_PRINT("%s", GET_IPADDR_STRING(tptr));
tptr += (sizeof(nd_ipv4));
tlen -= (sizeof(nd_ipv4));
tnhlen -= (sizeof(nd_ipv4));
}
break;
case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
break;
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
if (tnhlen < BGP_VPN_RD_LEN+1) {
ND_PRINT("invalid len");
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
} else {
ND_TCHECK_LEN(tptr, tnhlen);
ND_PRINT("RD: %s, %s",
bgp_vpn_rd_print(ndo, tptr),
GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
/* rfc986 mapped IPv4 address ? */
if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
/* rfc1888 mapped IPv6 address ? */
else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
}
break;
default:
/*
* bgp_mp_af_print() should have saved us from
* an unsupported AFI/SAFI.
*/
ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
tptr += tnhlen;
tlen -= tnhlen;
tnhlen = 0;
goto done;
break;
}
}
}
ND_PRINT(", nh-length: %u", nhlen);
/* As per RFC 2858; this is reserved in RFC 4760 */
if (tlen < 1)
goto trunc;
snpa = GET_U_1(tptr);
tptr++;
tlen--;
if (snpa) {
ND_PRINT("\n\t %u SNPA", snpa);
for (/*nothing*/; snpa != 0; snpa--) {
uint8_t snpalen;
if (tlen < 1)
goto trunc;
snpalen = GET_U_1(tptr);
ND_PRINT("\n\t %u bytes", snpalen);
tptr++;
tlen--;
if (tlen < snpalen)
goto trunc;
ND_TCHECK_LEN(tptr, snpalen);
tptr += snpalen;
tlen -= snpalen;
}
} else {
ND_PRINT(", no SNPA");
}
add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
while (tptr < pptr + len) {
advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
add_path4, add_path6);
if (advance == -2)
goto trunc;
if (advance < 0)
break;
tptr += advance;
}
break;
case BGPTYPE_MP_UNREACH_NLRI:
ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
if (ret == -2)
goto trunc;
if (ret < 0)
break;
if (len == BGP_MP_NLRI_MINSIZE)
ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
tptr += 3;
add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
while (tptr < pptr + len) {
advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
add_path4, add_path6);
if (advance == -2)
goto trunc;
if (advance < 0)
break;
tptr += advance;
}
break;
case BGPTYPE_EXTD_COMMUNITIES:
if (len % 8) {
ND_PRINT("invalid len");
break;
}
while (tlen != 0) {
uint16_t extd_comm;
ND_TCHECK_2(tptr);
if (tlen < 2)
goto trunc;
extd_comm=GET_BE_U_2(tptr);
ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
tok2str(bgp_extd_comm_subtype_values,
"unknown extd community typecode",
extd_comm),
extd_comm,
bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
ND_TCHECK_8(tptr);
if (tlen < 8)
goto trunc;
ND_PRINT(": ");
bgp_extended_community_print(ndo, tptr);
tlen -= 8;
tptr += 8;
}
break;
case BGPTYPE_PMSI_TUNNEL:
{
uint8_t tunnel_type, flags;
ND_TCHECK_5(tptr);
if (tlen < 5)
goto trunc;
flags = GET_U_1(tptr);
tunnel_type = GET_U_1(tptr + 1);
ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
tunnel_type,
bittok2str(bgp_pmsi_flag_values, "none", flags),
GET_BE_U_3(tptr + 2)>>4);
tptr +=5;
tlen -= 5;
switch (tunnel_type) {
case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
case BGP_PMSI_TUNNEL_PIM_BIDIR:
ND_PRINT("\n\t Sender %s, P-Group %s",
GET_IPADDR_STRING(tptr),
GET_IPADDR_STRING(tptr+4));
break;
case BGP_PMSI_TUNNEL_PIM_SSM:
ND_PRINT("\n\t Root-Node %s, P-Group %s",
GET_IPADDR_STRING(tptr),
GET_IPADDR_STRING(tptr+4));
break;
case BGP_PMSI_TUNNEL_INGRESS:
ND_PRINT("\n\t Tunnel-Endpoint %s",
GET_IPADDR_STRING(tptr));
break;
case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
case BGP_PMSI_TUNNEL_LDP_MP2MP:
ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
GET_IPADDR_STRING(tptr),
GET_BE_U_4(tptr + 4));
break;
case BGP_PMSI_TUNNEL_RSVP_P2MP:
ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
GET_IPADDR_STRING(tptr),
GET_BE_U_4(tptr + 4));
break;
default:
if (ndo->ndo_vflag <= 1) {
print_unknown_data(ndo, tptr, "\n\t ", tlen);
}
}
break;
}
case BGPTYPE_AIGP:
{
uint8_t type;
uint16_t length;
while (tlen >= 3) {
type = GET_U_1(tptr);
length = GET_BE_U_2(tptr + 1);
tptr += 3;
tlen -= 3;
ND_PRINT("\n\t %s TLV (%u), length %u",
tok2str(bgp_aigp_values, "Unknown", type),
type, length);
if (length < 3)
goto trunc;
length -= 3;
/*
* Check if we can read the TLV data.
*/
ND_TCHECK_LEN(tptr + 3, length);
if (tlen < length)
goto trunc;
switch (type) {
case BGP_AIGP_TLV:
if (length < 8)
goto trunc;
ND_PRINT(", metric %" PRIu64,
GET_BE_U_8(tptr));
break;
default:
if (ndo->ndo_vflag <= 1) {
print_unknown_data(ndo, tptr,"\n\t ", length);
}
}
tptr += length;
tlen -= length;
}
break;
}
case BGPTYPE_ATTR_SET:
ND_TCHECK_4(tptr);
if (len < 4)
goto trunc;
ND_PRINT("\n\t Origin AS: %s",
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
tptr += 4;
len -= 4;
while (len) {
u_int aflags, alenlen, alen;
ND_TCHECK_2(tptr);
if (len < 2) {
ND_PRINT(" [path attr too short]");
tptr += len;
break;
}
aflags = GET_U_1(tptr);
atype = GET_U_1(tptr + 1);
tptr += 2;
len -= 2;
alenlen = bgp_attr_lenlen(aflags, tptr);
ND_TCHECK_LEN(tptr, alenlen);
if (len < alenlen) {
ND_PRINT(" [path attr too short]");
tptr += len;
break;
}
alen = bgp_attr_len(aflags, tptr);
tptr += alenlen;
len -= alenlen;
ND_PRINT("\n\t %s (%u), length: %u",
tok2str(bgp_attr_values,
"Unknown Attribute", atype),
atype,
alen);
if (aflags) {
ND_PRINT(", Flags [%s%s%s%s",
aflags & 0x80 ? "O" : "",
aflags & 0x40 ? "T" : "",
aflags & 0x20 ? "P" : "",
aflags & 0x10 ? "E" : "");
if (aflags & 0xf)
ND_PRINT("+%x", aflags & 0xf);
ND_PRINT("]");
}
ND_PRINT(": ");
if (len < alen) {
ND_PRINT(" [path attr too short]");
tptr += len;
break;
}
/*
* The protocol encoding per se allows ATTR_SET to be nested
* as many times as the message can accommodate. This printer
* used to be able to recurse into ATTR_SET contents until the
* stack exhaustion, but now there is a limit on that (if live
* protocol exchange goes that many levels deep, something is
* probably wrong anyway). Feel free to refine this value if
* you can find the spec with respective normative text.
*/
if (attr_set_level == 10)
ND_PRINT("(too many nested levels, not recursing)");
else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
return 0;
tptr += alen;
len -= alen;
}
break;
case BGPTYPE_LARGE_COMMUNITY:
if (len == 0 || len % 12) {
ND_PRINT("invalid len");
break;
}
ND_PRINT("\n\t ");
while (len != 0) {
ND_PRINT("%u:%u:%u%s",
GET_BE_U_4(tptr),
GET_BE_U_4(tptr + 4),
GET_BE_U_4(tptr + 8),
(len > 12) ? ", " : "");
tptr += 12;
/*
* len will always be a multiple of 12, as per the above,
* so this will never underflow.
*/
len -= 12;
}
break;
default:
ND_TCHECK_LEN(pptr, len);
ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
if (ndo->ndo_vflag <= 1)
print_unknown_data(ndo, pptr, "\n\t ", len);
break;
}
done:
if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
ND_TCHECK_LEN(pptr, len);
print_unknown_data(ndo, pptr, "\n\t ", len);
}
return 1;
trunc:
return 0;
}
static void
bgp_capabilities_print(netdissect_options *ndo,
const u_char *opt, u_int caps_len)
{
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
u_int cap_type, cap_len, tcap_len, cap_offset;
u_int i = 0;
while (i < caps_len) {
ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
cap_type=GET_U_1(opt + i);
cap_len=GET_U_1(opt + i + 1);
ND_PRINT("\n\t %s (%u), length: %u",
tok2str(bgp_capcode_values, "Unknown", cap_type),
cap_type,
cap_len);
ND_TCHECK_LEN(opt + 2 + i, cap_len);
switch (cap_type) {
case BGP_CAPCODE_MP:
/* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
if (cap_len < 4) {
ND_PRINT(" (too short, < 4)");
return;
}
ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
GET_BE_U_2(opt + i + 2),
tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
GET_U_1(opt + i + 5));
break;
case BGP_CAPCODE_ML:
cap_offset = 2;
tcap_len = cap_len;
while (tcap_len >= 4) {
ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
tok2str(af_values, "Unknown",
GET_BE_U_2(opt + i + cap_offset)),
GET_BE_U_2(opt + i + cap_offset),
tok2str(bgp_safi_values, "Unknown",
GET_U_1(opt + i + cap_offset + 2)),
GET_U_1(opt + i + cap_offset + 2),
GET_U_1(opt + i + cap_offset + 3));
tcap_len -= 4;
cap_offset += 4;
}
break;
case BGP_CAPCODE_RESTART:
/* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
if (cap_len < 2) {
ND_PRINT(" (too short, < 2)");
return;
}
tcap_len=cap_len;
ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
GET_BE_U_2(opt + i + 2)&0xfff);
tcap_len-=2;
cap_offset=4;
while(tcap_len>=4) {
ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
tok2str(af_values,"Unknown",
GET_BE_U_2(opt + i + cap_offset)),
GET_BE_U_2(opt + i + cap_offset),
tok2str(bgp_safi_values,"Unknown",
GET_U_1(opt + i + cap_offset + 2)),
GET_U_1(opt + (i + cap_offset + 2)),
((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
tcap_len -= 4;
cap_offset += 4;
}
break;
case BGP_CAPCODE_RR:
case BGP_CAPCODE_LLGR:
case BGP_CAPCODE_RR_CISCO:
break;
case BGP_CAPCODE_AS_NEW:
/*
* Extract the 4 byte AS number encoded.
*/
if (cap_len < 4) {
ND_PRINT(" (too short, < 4)");
return;
}
ND_PRINT("\n\t\t 4 Byte AS %s",
as_printf(ndo, astostr, sizeof(astostr),
GET_BE_U_4(opt + i + 2)));
break;
case BGP_CAPCODE_ADD_PATH:
if (cap_len == 0) {
ND_PRINT(" (bogus)"); /* length */
break;
}
tcap_len=cap_len;
cap_offset=2;
while (tcap_len != 0) {
if (tcap_len < 4) {
nd_print_invalid(ndo);
break;
}
ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
GET_BE_U_2(opt + i + cap_offset),
tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
GET_U_1(opt + (i + cap_offset + 2)),
tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
);
tcap_len -= 4;
cap_offset += 4;
}
break;
default:
ND_PRINT("\n\t\tno decoder for Capability %u",
cap_type);
if (ndo->ndo_vflag <= 1)
print_unknown_data(ndo, opt + i + 2, "\n\t\t",
cap_len);
break;
}
if (ndo->ndo_vflag > 1 && cap_len != 0) {
print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
}
i += BGP_CAP_HEADER_SIZE + cap_len;
}
return;
trunc:
nd_print_trunc(ndo);
}
static void
bgp_open_print(netdissect_options *ndo,
const u_char *dat, u_int length)
{
/* allocate space for the largest possible string */
char astostr[AS_STR_SIZE];
const struct bgp_open *bgp_open_header;
u_int optslen;
const struct bgp_opt *bgpopt;
const u_char *opt;
u_int i;
ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
if (length < BGP_OPEN_SIZE)
goto trunc;
bgp_open_header = (const struct bgp_open *)dat;
ND_PRINT("\n\t Version %u, ",
GET_U_1(bgp_open_header->bgpo_version));
ND_PRINT("my AS %s, ",
as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
ND_PRINT("Holdtime %us, ",
GET_BE_U_2(bgp_open_header->bgpo_holdtime));
ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
optslen = GET_U_1(bgp_open_header->bgpo_optlen);
ND_PRINT("\n\t Optional parameters, length: %u", optslen);
opt = dat + BGP_OPEN_SIZE;
length -= BGP_OPEN_SIZE;
i = 0;
while (i < optslen) {
uint8_t opt_type, opt_len;
ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
if (length < BGP_OPT_SIZE + i)
goto trunc;
bgpopt = (const struct bgp_opt *)(opt + i);
opt_type = GET_U_1(bgpopt->bgpopt_type);
opt_len = GET_U_1(bgpopt->bgpopt_len);
if (BGP_OPT_SIZE + i + opt_len > optslen) {
ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
opt_type, opt_len);
break;
}
ND_PRINT("\n\t Option %s (%u), length: %u",
tok2str(bgp_opt_values,"Unknown",opt_type),
opt_type,
opt_len);
/* now let's decode the options we know*/
switch(opt_type) {
case BGP_OPT_CAP:
bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
opt_len);
break;
case BGP_OPT_AUTH:
default:
ND_PRINT("\n\t no decoder for option %u",
opt_type);
break;
}
i += BGP_OPT_SIZE + opt_len;
}
return;
trunc:
nd_print_trunc(ndo);
}
static void
bgp_update_print(netdissect_options *ndo,
const u_char *dat, u_int length)
{
const u_char *p;
u_int withdrawn_routes_len;
char buf[MAXHOSTNAMELEN + 100];
int wpfx;
u_int len;
int i;
int add_path;
u_int path_id = 0;
ND_TCHECK_LEN(dat, BGP_SIZE);
if (length < BGP_SIZE)
goto trunc;
p = dat + BGP_SIZE;
length -= BGP_SIZE;
/* Unfeasible routes */
ND_TCHECK_2(p);
if (length < 2)
goto trunc;
withdrawn_routes_len = GET_BE_U_2(p);
p += 2;
length -= 2;
if (withdrawn_routes_len > 1) {
/*
* Without keeping state from the original NLRI message,
* it's not possible to tell if this a v4 or v6 route,
* so only try to decode it if we're not v6 enabled.
*/
ND_TCHECK_LEN(p, withdrawn_routes_len);
if (length < withdrawn_routes_len)
goto trunc;
ND_PRINT("\n\t Withdrawn routes:");
add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
while (withdrawn_routes_len != 0) {
if (add_path) {
if (withdrawn_routes_len < 4) {
p += withdrawn_routes_len;
length -= withdrawn_routes_len;
break;
}
path_id = GET_BE_U_4(p);
p += 4;
length -= 4;
withdrawn_routes_len -= 4;
}
wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
if (wpfx == -1) {
ND_PRINT("\n\t (illegal prefix length)");
break;
} else if (wpfx == -2)
goto trunc; /* bytes left, but not enough */
else {
ND_PRINT("\n\t %s", buf);
if (add_path) {
ND_PRINT(" Path Id: %u", path_id);
}
p += wpfx;
length -= wpfx;
withdrawn_routes_len -= wpfx;
}
}
} else {
ND_TCHECK_LEN(p, withdrawn_routes_len);
if (length < withdrawn_routes_len)
goto trunc;
p += withdrawn_routes_len;
length -= withdrawn_routes_len;
}
ND_TCHECK_2(p);
if (length < 2)
goto trunc;
len = GET_BE_U_2(p);
p += 2;
length -= 2;
if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
/* No withdrawn routes, no path attributes, no NLRI */
ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
return;
}
if (len) {
/* do something more useful!*/
while (len) {
uint8_t aflags, atype, alenlen;
uint16_t alen;
ND_TCHECK_2(p);
if (length < 2)
goto trunc;
if (len < 2) {
ND_PRINT("\n\t [path attrs too short]");
p += len;
length -= len;
break;
}
aflags = GET_U_1(p);
atype = GET_U_1(p + 1);
p += 2;
len -= 2;
length -= 2;
alenlen = bgp_attr_lenlen(aflags, p);
ND_TCHECK_LEN(p, alenlen);
if (length < alenlen)
goto trunc;
if (len < alenlen) {
ND_PRINT("\n\t [path attrs too short]");
p += len;
length -= len;
break;
}
alen = bgp_attr_len(aflags, p);
p += alenlen;
len -= alenlen;
length -= alenlen;
ND_PRINT("\n\t %s (%u), length: %u",
tok2str(bgp_attr_values, "Unknown Attribute", atype),
atype,
alen);
if (aflags) {
ND_PRINT(", Flags [%s%s%s%s",
aflags & 0x80 ? "O" : "",
aflags & 0x40 ? "T" : "",
aflags & 0x20 ? "P" : "",
aflags & 0x10 ? "E" : "");
if (aflags & 0xf)
ND_PRINT("+%x", aflags & 0xf);
ND_PRINT("]: ");
}
if (len < alen) {
ND_PRINT(" [path attrs too short]");
p += len;
length -= len;
break;
}
if (length < alen)
goto trunc;
if (!bgp_attr_print(ndo, atype, p, alen, 0))
goto trunc;
p += alen;
len -= alen;
length -= alen;
}
}
if (length) {
add_path = check_add_path(ndo, p, length, 32);
ND_PRINT("\n\t Updated routes:");
while (length != 0) {
if (add_path) {
ND_TCHECK_4(p);
if (length < 4)
goto trunc;
path_id = GET_BE_U_4(p);
p += 4;
length -= 4;
}
i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
if (i == -1) {
ND_PRINT("\n\t (illegal prefix length)");
break;
} else if (i == -2)
goto trunc; /* bytes left, but not enough */
else {
ND_PRINT("\n\t %s", buf);
if (add_path) {
ND_PRINT(" Path Id: %u", path_id);
}
p += i;
length -= i;
}
}
}
return;
trunc:
nd_print_trunc(ndo);
}
static void
bgp_notification_print(netdissect_options *ndo,
const u_char *dat, u_int length)
{
const struct bgp_notification *bgp_notification_header;
const u_char *tptr;
uint8_t bgpn_major, bgpn_minor;
uint8_t shutdown_comm_length;
uint8_t remainder_offset;
ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
if (length<BGP_NOTIFICATION_SIZE)
return;
bgp_notification_header = (const struct bgp_notification *)dat;
bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
ND_PRINT(", %s (%u)",
tok2str(bgp_notify_major_values, "Unknown Error",
bgpn_major),
bgpn_major);
switch (bgpn_major) {
case BGP_NOTIFY_MAJOR_MSG:
ND_PRINT(", subcode %s (%u)",
tok2str(bgp_notify_minor_msg_values, "Unknown",
bgpn_minor),
bgpn_minor);
break;
case BGP_NOTIFY_MAJOR_OPEN:
ND_PRINT(", subcode %s (%u)",
tok2str(bgp_notify_minor_open_values, "Unknown",
bgpn_minor),
bgpn_minor);
break;
case BGP_NOTIFY_MAJOR_UPDATE:
ND_PRINT(", subcode %s (%u)",
tok2str(bgp_notify_minor_update_values, "Unknown",
bgpn_minor),
bgpn_minor);
break;
case BGP_NOTIFY_MAJOR_FSM:
ND_PRINT(" subcode %s (%u)",
tok2str(bgp_notify_minor_fsm_values, "Unknown",
bgpn_minor),
bgpn_minor);
break;
case BGP_NOTIFY_MAJOR_CAP:
ND_PRINT(" subcode %s (%u)",
tok2str(bgp_notify_minor_cap_values, "Unknown",
bgpn_minor),
bgpn_minor);
break;
case BGP_NOTIFY_MAJOR_CEASE:
ND_PRINT(", subcode %s (%u)",
tok2str(bgp_notify_minor_cease_values, "Unknown",
bgpn_minor),
bgpn_minor);
/* draft-ietf-idr-cease-subcode-02 mentions optionally 7 bytes
* for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
*/
if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
tptr = dat + BGP_NOTIFICATION_SIZE;
ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
GET_BE_U_2(tptr),
tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
GET_U_1((tptr + 2)),
GET_BE_U_4(tptr + 3));
}
/*
* draft-ietf-idr-shutdown describes a method to send a communication
* intended for human consumption regarding the Administrative Shutdown
*/
if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
length >= BGP_NOTIFICATION_SIZE + 1) {
tptr = dat + BGP_NOTIFICATION_SIZE;
shutdown_comm_length = GET_U_1(tptr);
remainder_offset = 0;
/* garbage, hexdump it all */
if (shutdown_comm_length > BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN ||
shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
ND_PRINT(", invalid Shutdown Communication length");
}
else if (shutdown_comm_length == 0) {
ND_PRINT(", empty Shutdown Communication");
remainder_offset += 1;
}
/* a proper shutdown communication */
else {
ND_TCHECK_LEN(tptr + 1, shutdown_comm_length);
ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
nd_printjn(ndo, tptr+1, shutdown_comm_length);
ND_PRINT("\"");
remainder_offset += shutdown_comm_length + 1;
}
/* if there is trailing data, hexdump it */
if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
}
}
break;
default:
break;
}
return;
trunc:
nd_print_trunc(ndo);
}
static void
bgp_route_refresh_print(netdissect_options *ndo,
const u_char *pptr, u_int len)
{
const struct bgp_route_refresh *bgp_route_refresh_header;
ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
/* some little sanity checking */
if (len<BGP_ROUTE_REFRESH_SIZE)
return;
bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
tok2str(af_values,"Unknown",
GET_BE_U_2(bgp_route_refresh_header->afi)),
GET_BE_U_2(bgp_route_refresh_header->afi),
tok2str(bgp_safi_values,"Unknown",
GET_U_1(bgp_route_refresh_header->safi)),
GET_U_1(bgp_route_refresh_header->safi));
if (ndo->ndo_vflag > 1) {
ND_TCHECK_LEN(pptr, len);
print_unknown_data(ndo, pptr, "\n\t ", len);
}
return;
trunc:
nd_print_trunc(ndo);
}
static int
bgp_pdu_print(netdissect_options *ndo,
const u_char *dat, u_int length)
{
const struct bgp *bgp_header;
uint8_t bgp_type;
ND_TCHECK_LEN(dat, BGP_SIZE);
bgp_header = (const struct bgp *)dat;
bgp_type = GET_U_1(bgp_header->bgp_type);
ND_PRINT("\n\t%s Message (%u), length: %u",
tok2str(bgp_msg_values, "Unknown", bgp_type),
bgp_type,
length);
switch (bgp_type) {
case BGP_OPEN:
bgp_open_print(ndo, dat, length);
break;
case BGP_UPDATE:
bgp_update_print(ndo, dat, length);
break;
case BGP_NOTIFICATION:
bgp_notification_print(ndo, dat, length);
break;
case BGP_KEEPALIVE:
break;
case BGP_ROUTE_REFRESH:
bgp_route_refresh_print(ndo, dat, length);
break;
default:
/* we have no decoder for the BGP message */
ND_TCHECK_LEN(dat, length);
ND_PRINT("\n\t no Message %u decoder", bgp_type);
print_unknown_data(ndo, dat, "\n\t ", length);
break;
}
return 1;
trunc:
nd_print_trunc(ndo);
return 0;
}
void
bgp_print(netdissect_options *ndo,
const u_char *dat, u_int length _U_)
{
const u_char *p;
const u_char *ep = ndo->ndo_snapend;
const u_char *start;
const u_char marker[] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};
const struct bgp *bgp_header;
uint16_t hlen;
ndo->ndo_protocol = "bgp";
ND_PRINT(": BGP");
if (ndo->ndo_vflag < 1) /* lets be less chatty */
return;
p = dat;
start = p;
while (p < ep) {
if (!ND_TTEST_1(p))
break;
if (GET_U_1(p) != 0xff) {
p++;
continue;
}
if (!ND_TTEST_LEN(p, sizeof(marker)))
break;
if (memcmp(p, marker, sizeof(marker)) != 0) {
p++;
continue;
}
/* found BGP header */
ND_TCHECK_LEN(p, BGP_SIZE);
bgp_header = (const struct bgp *)p;
if (start != p)
nd_print_trunc(ndo);
hlen = GET_BE_U_2(bgp_header->bgp_len);
if (hlen < BGP_SIZE) {
ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
nd_print_invalid(ndo);
break;
}
if (ND_TTEST_LEN(p, hlen)) {
if (!bgp_pdu_print(ndo, p, hlen))
return;
p += hlen;
start = p;
} else {
ND_PRINT("\n[|BGP %s]",
tok2str(bgp_msg_values,
"Unknown Message Type",
GET_U_1(bgp_header->bgp_type)));
break;
}
}
return;
trunc:
nd_print_trunc(ndo);
}
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