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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 17:13:01 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 17:13:01 +0000 |
| commit | 7adcb5b605cc1328a3084c334f4697ec9771936c (patch) | |
| tree | 03e681bfda053978ba896745828e09cb056ad156 /print-bgp.c | |
| parent | Initial commit. (diff) | |
| download | tcpdump-7adcb5b605cc1328a3084c334f4697ec9771936c.tar.xz tcpdump-7adcb5b605cc1328a3084c334f4697ec9771936c.zip | |
Adding upstream version 4.99.4.upstream/4.99.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'print-bgp.c')
| -rw-r--r-- | print-bgp.c | 3162 |
1 files changed, 3162 insertions, 0 deletions
diff --git a/print-bgp.c b/print-bgp.c new file mode 100644 index 0000000..efeaea4 --- /dev/null +++ b/print-bgp.c @@ -0,0 +1,3162 @@ +/* + * 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} +}; + +/* RFC 4486 */ +#define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1 +#define BGP_NOTIFY_MINOR_CEASE_SHUT 2 +#define BGP_NOTIFY_MINOR_CEASE_RESET 4 +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 + 4); + 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[sizeof("0000 0000 0000 0000")] = ""; + 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, + * hence 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. + */ + 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) { + /* Make sure the path attributes don't go past the end of the packet */ + if (length < len) + goto trunc; + /* 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; + + 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); + + /* RFC 4486 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)); + } + /* + * RFC 9003 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; + uint8_t shutdown_comm_length = GET_U_1(tptr); + uint8_t remainder_offset = 0; + /* garbage, hexdump it all */ + if (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_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length); + (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL); + 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); +} |