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BGP: Use VNI when VXLAN/VXLAN-GPE encapsulation is specified 

RFC8365 and draft-ietf-idr-tunnel-encaps-15 defines to use the
MPLS Label field to carry the VNI in the presence of a Tunnel
Encapsulation Extended Community specifying the use of a VNI.

This is the case for VXLAN and VXLAN-GPE tunnel types.

Bug: 16643
Change-Id: I4ffc8b024c2102b7fab4d7cb3dd1a5d69c569c12
Reviewed-on: https://code.wireshark.org/review/37551
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
Uli Heilmeier 2020-06-23 21:20:54 +02:00 committed by Anders Broman
parent 2471ae1e0e
commit 006a7f5115
1 changed files with 87 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

101
epan/dissectors/packet-bgp.c
View File

@ -1843,6 +1843,7 @@ static int hf_bgp_evpn_nlri_esi_reserved = -1;
static int hf_bgp_evpn_nlri_etag = -1;
static int hf_bgp_evpn_nlri_mpls_ls1 = -1;
static int hf_bgp_evpn_nlri_mpls_ls2 = -1;
static int hf_bgp_evpn_nlri_vni = -1;
static int hf_bgp_evpn_nlri_maclen = -1;
static int hf_bgp_evpn_nlri_mac_addr = -1;
static int hf_bgp_evpn_nlri_iplen = -1;
@ -2599,6 +2600,35 @@ load_link_state_data(packet_info *pinfo) {
return data;
}
typedef struct _path_attr_data {
gboolean encaps_community_present;
guint16 encaps_tunnel_type;
} path_attr_data;
#define PATH_ATTR_DATA_KEY 1
static void
save_path_attr_encaps_tunnel_type(packet_info *pinfo, guint32 encaps_tunnel_type) {
path_attr_data *data =
(path_attr_data*)p_get_proto_data(pinfo->pool, pinfo, proto_bgp, PATH_ATTR_DATA_KEY);
if (!data) {
data = wmem_new0(pinfo->pool, path_attr_data);
data->encaps_tunnel_type = 0;
data->encaps_community_present = FALSE;
}
data->encaps_community_present = TRUE;
data->encaps_tunnel_type = encaps_tunnel_type;
p_add_proto_data(pinfo->pool, pinfo, proto_bgp, PATH_ATTR_DATA_KEY, data);
return;
}
static path_attr_data*
load_path_attr_data(packet_info *pinfo) {
path_attr_data *data =
(path_attr_data*)p_get_proto_data(pinfo->pool, pinfo, proto_bgp, PATH_ATTR_DATA_KEY);
return data;
}
/*
* Detect IPv4/IPv6 prefixes conform to BGP Additional Path but NOT conform to standard BGP
*
@ -5044,6 +5074,7 @@ static int decode_evpn_nlri(proto_tree *tree, tvbuff_t *tvb, gint offset, packet
guint8 ip_len;
guint32 total_length = 0;
guint32 or_length;
path_attr_data *data = NULL;
proto_item *item;
int ret;
@ -5095,8 +5126,15 @@ static int decode_evpn_nlri(proto_tree *tree, tvbuff_t *tvb, gint offset, packet
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_etag, tvb, reader_offset,
4, ENC_BIG_ENDIAN);
reader_offset += 4;
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls1, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
data = load_path_attr_data(pinfo);
if (data && data->encaps_community_present &&
(data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLAN || data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLANGPE)) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_vni, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
} else {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls1, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
}
total_length = reader_offset - offset;
break;
@ -5180,13 +5218,24 @@ static int decode_evpn_nlri(proto_tree *tree, tvbuff_t *tvb, gint offset, packet
} else {
return -1;
}
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls1, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
/* we check if we reached the end of the nlri reading fields one by one */
/* if not, the second optional label is in the payload */
if (reader_offset - start_offset < nlri_len) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls2, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
data = load_path_attr_data(pinfo);
if (data && data->encaps_community_present &&
(data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLAN || data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLANGPE)) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_vni, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
if (reader_offset - start_offset < nlri_len) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_vni, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
}
} else {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls1, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
/* we check if we reached the end of the nlri reading fields one by one */
/* if not, the second optional label is in the payload */
if (reader_offset - start_offset < nlri_len) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_mpls_ls2, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
reader_offset += 3;
}
}
total_length = reader_offset - offset;
break;
@ -5366,7 +5415,13 @@ static int decode_evpn_nlri(proto_tree *tree, tvbuff_t *tvb, gint offset, packet
4, ENC_NA);
reader_offset += 4;
decode_MPLS_stack_tree(tvb, reader_offset, prefix_tree);
data = load_path_attr_data(pinfo);
if (data && data->encaps_community_present &&
(data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLAN || data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLANGPE)) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_vni, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
} else {
decode_MPLS_stack_tree(tvb, reader_offset, prefix_tree);
}
total_length = 36;
break;
case 58 :
@ -5379,7 +5434,13 @@ static int decode_evpn_nlri(proto_tree *tree, tvbuff_t *tvb, gint offset, packet
16, ENC_NA);
reader_offset += 16;
decode_MPLS_stack_tree(tvb, reader_offset, prefix_tree);
data = load_path_attr_data(pinfo);
if (data && data->encaps_community_present &&
(data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLAN || data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLANGPE)) {
proto_tree_add_item(prefix_tree, hf_bgp_evpn_nlri_vni, tvb, reader_offset, 3, ENC_BIG_ENDIAN);
} else {
decode_MPLS_stack_tree(tvb, reader_offset, prefix_tree);
}
total_length = 60;
break;
default :
@ -6774,7 +6835,7 @@ heuristic_as2_or_4_from_as_path(tvbuff_t *tvb, gint as_path_offset, gint end_att
*/
static int
dissect_bgp_update_ext_com(proto_tree *parent_tree, tvbuff_t *tvb, guint16 tlen, guint tvb_off)
dissect_bgp_update_ext_com(proto_tree *parent_tree, tvbuff_t *tvb, guint16 tlen, guint tvb_off, packet_info *pinfo)
{
int offset=0;
int end=0;
@ -6786,6 +6847,7 @@ dissect_bgp_update_ext_com(proto_tree *parent_tree, tvbuff_t *tvb, guint16 tlen,
proto_item *communities_item=NULL;
proto_item *community_item=NULL;
proto_item *community_type_item=NULL;
guint32 encaps_tunnel_type;
offset = tvb_off ;
end = tvb_off + tlen ;
@ -6978,7 +7040,8 @@ dissect_bgp_update_ext_com(proto_tree *parent_tree, tvbuff_t *tvb, guint16 tlen,
case BGP_EXT_COM_STYPE_OPA_ENCAP:
/* Community octets 2 through 5 are reserved and carry no useful value according to RFC 5512. */
proto_tree_add_item(community_tree, hf_bgp_ext_com_tunnel_type, tvb, offset+6, 2, ENC_BIG_ENDIAN);
proto_tree_add_item_ret_uint(community_tree, hf_bgp_ext_com_tunnel_type, tvb, offset+6, 2, ENC_BIG_ENDIAN, &encaps_tunnel_type);
save_path_attr_encaps_tunnel_type(pinfo, encaps_tunnel_type);
proto_item_append_text(community_item, " %s",
val_to_str_const(tvb_get_ntohs(tvb,offset+6), bgpext_com_tunnel_type, "Unknown"));
@ -7528,6 +7591,7 @@ dissect_bgp_update_pmsi_attr(packet_info *pinfo, proto_tree *parent_tree, tvbuff
proto_item *opaque_value_type_item=NULL;
proto_item *pmsi_tunnel_type_item=NULL;
proto_tree *tunnel_id_tree=NULL;
path_attr_data *data = NULL;
offset = tvb_off ;
tunnel_id_len = tlen - 5;
@ -7538,7 +7602,13 @@ dissect_bgp_update_pmsi_attr(packet_info *pinfo, proto_tree *parent_tree, tvbuff
pmsi_tunnel_type_item = proto_tree_add_item(parent_tree, hf_bgp_pmsi_tunnel_type, tvb, offset+1,
1, ENC_BIG_ENDIAN);
proto_tree_add_item(parent_tree, hf_bgp_update_mpls_label_value_20bits, tvb, offset+2, 3, ENC_BIG_ENDIAN);
data = load_path_attr_data(pinfo);
if (data && data->encaps_community_present &&
(data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLAN || data->encaps_tunnel_type == BGP_EXT_COM_TUNNEL_VXLANGPE)) {
proto_tree_add_item(parent_tree, hf_bgp_evpn_nlri_vni, tvb, offset+2, 3, ENC_BIG_ENDIAN);
} else {
proto_tree_add_item(parent_tree, hf_bgp_update_mpls_label_value_20bits, tvb, offset+2, 3, ENC_BIG_ENDIAN);
}
tunnel_id_item = proto_tree_add_item(parent_tree, hf_bgp_pmsi_tunnel_id, tvb, offset+5,
tunnel_id_len, ENC_NA);
@ -8183,7 +8253,7 @@ dissect_bgp_path_attr(proto_tree *subtree, tvbuff_t *tvb, guint16 path_attr_len,
expert_add_info_format(pinfo, attr_len_item, &ei_bgp_ext_com_len_bad,
"Community length %u wrong, must be modulo 8", tlen);
} else {
dissect_bgp_update_ext_com(subtree2, tvb, tlen, o+i+aoff);
dissect_bgp_update_ext_com(subtree2, tvb, tlen, o+i+aoff, pinfo);
}
break;
case BGPTYPE_SAFI_SPECIFIC_ATTR:
@ -11222,6 +11292,9 @@ proto_register_bgp(void)
{ &hf_bgp_evpn_nlri_mpls_ls2,
{ "MPLS Label 2", "bgp.evpn.nlri.mpls_ls2", FT_UINT24,
BASE_DEC, NULL, BGP_MPLS_LABEL, NULL, HFILL}},
{ &hf_bgp_evpn_nlri_vni,
{ "VNI", "bgp.evpn.nlri.vni", FT_UINT24,
BASE_DEC, NULL, 0x0, NULL, HFILL}},
{ &hf_bgp_evpn_nlri_maclen,
{ "MAC Address Length", "bgp.evpn.nlri.maclen", FT_UINT8,
BASE_DEC, NULL, 0x0, NULL, HFILL}},