BGP: Tunnel Encapsulation attribute

Refer to RFC 9012, The BGP Tunnel Encapsulation Attribute.

3 files changed, 47 insertions, 1 deletions

diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 4346cd5d..c6d5312c 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -22,6 +22,7 @@
 #include "lib/resource.h"
 #include "lib/string.h"
 #include "lib/unaligned.h"
+#include "lib/tunnel_encaps.h"
 
 #include "bgp.h"
 
@@ -917,6 +918,39 @@ bgp_decode_otc(struct bgp_parse_state *s, uint code UNUSED, uint flags, byte *da
 
 
 static void
+bgp_export_tunnel_encap(struct bgp_export_state *s UNUSED, eattr *a)
+{
+  if (a->u.ptr->length == 0)
+    UNSET(a);
+
+  /*
+   * TODO: In situations where a tunnel could be encoded using a barebones TLV,
+   * it MUST be encoded using the corresponding Encapsulation Extended
+   * Community. (RFC9012 section 4.1)
+   */
+}
+
+static void
+bgp_decode_tunnel_encap(struct bgp_parse_state *s, uint code UNUSED, uint flags, byte *data, uint len, ea_list **to)
+{
+  bgp_set_attr_data(to, s->pool, BA_TUNNEL_ENCAP, flags, data, len);
+}
+
+static int
+bgp_encode_tunnel_encap(struct bgp_write_state *s UNUSED, eattr *a, byte *buf, uint size)
+{
+  return bgp_put_attr(buf, size, EA_ID(a->id), a->flags, a->u.ptr->data, a->u.ptr->length);
+}
+
+static void
+bgp_format_tunnel_encap(const eattr *a, byte *buf, uint size)
+{
+  int l = format_tunnel_encap(a->u.ptr, buf, size);
+  if (l > 0)
+    ADVANCE(buf, size, l);
+}
+
+static void
 bgp_export_mpls_label_stack(struct bgp_export_state *s, eattr *a)
 {
   net_addr *n = s->route->net->n.addr;
@@ -1136,6 +1170,15 @@ static const struct bgp_attr_desc bgp_attr_table[] = {
     .encode = bgp_encode_u32,
     .decode = bgp_decode_otc,
   },
+  [BA_TUNNEL_ENCAP] = {
+    .name = "tunnel_encap",
+    .type = EAF_TYPE_TUNNEL_ENCAP,
+    .flags = BAF_OPTIONAL | BAF_TRANSITIVE,
+    .export = bgp_export_tunnel_encap,
+    .encode = bgp_encode_tunnel_encap,
+    .decode = bgp_decode_tunnel_encap,
+    .format = bgp_format_tunnel_encap,
+  },
   [BA_MPLS_LABEL_STACK] = {
     .name = "mpls_label_stack",
     .type = EAF_TYPE_INT_SET,
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index 2e95037c..3de9aed5 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -704,6 +704,7 @@ byte *bgp_create_end_mark_(struct bgp_channel *c, byte *buf);
 #define BA_EXT_COMMUNITY	0x10	/* RFC 4360 */
 #define BA_AS4_PATH             0x11	/* RFC 6793 */
 #define BA_AS4_AGGREGATOR       0x12	/* RFC 6793 */
+#define BA_TUNNEL_ENCAP		0x17	/* RFC 9012 */
 #define BA_AIGP			0x1a	/* RFC 7311 */
 #define BA_LARGE_COMMUNITY	0x20	/* RFC 8092 */
 #define BA_ONLY_TO_CUSTOMER	0x23	/* RFC 9234 */
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index 6981a117..f0605924 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -32,7 +32,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
 	LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY, INTERNAL, EXTERNAL, SETS,
 	DYNAMIC, RANGE, NAME, DIGITS, BGP_AIGP, AIGP, ORIGINATE, COST, ENFORCE,
 	FIRST, FREE, VALIDATE, BASE, ROLE, ROLES, PEER, PROVIDER, CUSTOMER,
-	RS_SERVER, RS_CLIENT, REQUIRE, BGP_OTC, GLOBAL)
+	RS_SERVER, RS_CLIENT, REQUIRE, BGP_OTC, GLOBAL, BGP_TUNNEL_ENCAP)
 
 %type <i> bgp_nh
 %type <i32> bgp_afi
@@ -364,6 +364,8 @@ dynamic_attr: BGP_LARGE_COMMUNITY
 	{ $$ = f_new_dynamic_attr(EAF_TYPE_LC_SET, T_LCLIST, EA_CODE(PROTOCOL_BGP, BA_LARGE_COMMUNITY)); } ;
 dynamic_attr: BGP_OTC
 	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_ONLY_TO_CUSTOMER)); } ;
+dynamic_attr: BGP_TUNNEL_ENCAP
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_TUNNEL_ENCAP, T_TLVLIST, EA_CODE(PROTOCOL_BGP, BA_TUNNEL_ENCAP)); } ;
 
 custom_attr: ATTRIBUTE BGP expr type symbol ';' {
   if ($3 > 255 || $3 < 1)