TunnelEncaps: Initial commit

16 files changed, 1712 insertions, 7 deletions

diff --git a/filter/config.Y b/filter/config.Y
index e2fbb296..c5426b2d 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -197,6 +197,138 @@ f_new_pair_set(int fa, int ta, int fb, int tb)
 #define LC_ALL 0xFFFFFFFF
 
 static struct f_tree *
+f_new_sub_tlv_int_item(u32 type, u32 v1)
+{
+  struct f_tree *t = f_new_tree();
+  t->right = t;
+  t->from.type = t->to.type = T_SUBTLV;
+  struct te_subtlv v;
+  v.type = type;
+  switch (type)
+  {
+  case TLV_COLOR:
+    v.u.color = v1;
+    break;
+  case TLV_UDP_DEST_PORT:
+    v.u.udp_dest_port = v1;
+    break;
+  default:
+    cf_error("Unsupported sub-TLV type: %d", type);
+  }
+  t->from.val.st = v;
+  t->to.val.st = v;
+  return t;
+}
+
+static struct f_tree *
+f_new_sub_tlv_tunnel_ep(u32 type, ip_addr ip)
+{
+  struct f_tree *t;
+
+  if (type != TLV_TUNNEL_ENDPOINT)
+    cf_error("Expected sub-TLV type %d, got %d", TLV_TUNNEL_ENDPOINT, type);
+
+  t = f_new_tree();
+  t->right = t;
+  t->from.type = t->to.type = T_SUBTLV;
+  struct te_subtlv v;
+  v.type = TLV_TUNNEL_ENDPOINT;
+  v.u.tunnel_endpoint.reserved = 0;
+  v.u.tunnel_endpoint.af = ipa_is_ip4(ip) ? AFI_IPV4 : AFI_IPV6;
+  v.u.tunnel_endpoint.ip = ip;
+  t->from.val.st = v;
+  t->to.val.st = v;
+  return t;
+}
+
+static struct f_tree *
+f_new_sub_tlv_encap(u32 st_type, u32 type, const struct adata *bytes)
+{
+  struct f_tree *t;
+
+  if (st_type != TLV_ENCAPSULATION)
+    cf_error("Expected sub-TLV type %d, got %d", TLV_ENCAPSULATION, type);
+
+  t = f_new_tree();
+  t->right = t;
+  t->from.type = t->to.type = T_SUBTLV;
+  struct te_subtlv v;
+  v.type = TLV_ENCAPSULATION;
+  v.u.tunnel_encap.type = type;
+  v.u.tunnel_encap.data = bytes->data;
+  v.u.tunnel_encap.length = bytes->length;
+  t->from.val.st = v;
+  t->to.val.st = v;
+  return t;
+}
+
+static struct f_tree *
+f_new_sub_tlv_unknown(u32 type, const struct adata *bytes)
+{
+  struct f_tree *t;
+
+  switch(type)
+  {
+  case TLV_TUNNEL_ENDPOINT:
+  case TLV_ENCAPSULATION:
+  case TLV_UDP_DEST_PORT:
+  case TLV_COLOR:
+    cf_error("Expected an unkonwn sub-TLV type got %d", type);
+  }
+
+  t = f_new_tree();
+  t->right = t;
+  t->from.type = t->to.type = T_SUBTLV;
+  struct te_subtlv v;
+  v.type = type;
+  v.u.unknown.data = bytes->data;
+  v.u.unknown.length = bytes->length;
+  t->from.val.st = v;
+  t->to.val.st = v;
+  return t;
+}
+
+static struct f_tree *
+f_new_sub_tlv_item(u32 type, struct f_inst *v1)
+{
+  struct f_val val;
+  enum filter_return ret = f_eval(f_linearize(v1, 1), cfg_mem, &val);
+
+  if (ret > F_RETURN)
+    cf_error("Runtime error while evaluating expression; see log for details");
+
+  switch(val.type)
+  {
+  case T_INT:
+    return f_new_sub_tlv_int_item(type, val.val.i);
+  case T_IP:
+    return f_new_sub_tlv_tunnel_ep(type, val.val.ip);
+  case T_BYTESTRING:
+    return f_new_sub_tlv_unknown(type, val.val.bs);
+  default:
+    cf_error("Integer or IP address expression expected");
+  }
+}
+
+static struct f_tree *
+f_new_sub_tlv_item2(u32 type, u32 v1, struct f_inst *v2)
+{
+  struct f_val val;
+  enum filter_return ret = f_eval(f_linearize(v2, 1), cfg_mem, &val);
+
+  if (ret > F_RETURN)
+    cf_error("Runtime error while evaluating expression; see log for details");
+
+  switch(val.type)
+  {
+  case T_BYTESTRING:
+    return f_new_sub_tlv_encap(type, v1, val.val.bs);
+  default:
+    cf_error("Integer or bytestring expression expected");
+  }
+}
+
+static struct f_tree *
 f_new_ec_item(u32 kind, u32 ipv4_used, u32 key, u32 vf, u32 vt)
 {
   u64 fm, to;
@@ -358,7 +490,7 @@ CF_KEYWORDS_EXCLUSIVE(IN)
 CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 	ACCEPT, REJECT, ERROR,
 	INT, BOOL, IP, PREFIX, RD, PAIR, QUAD, EC, LC,
-	SET, STRING, BYTESTRING, BGPMASK, BGPPATH, CLIST, ECLIST, LCLIST,
+	SET, STRING, BYTESTRING, BGPMASK, BGPPATH, CLIST, ECLIST, LCLIST, TLVLIST,
 	IF, THEN, ELSE, CASE,
 	FOR, DO,
 	TRUE, FALSE, RT, RO, UNKNOWN, GENERIC,
@@ -371,7 +503,7 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 	EMPTY,
 	FILTER, WHERE, EVAL, ATTRIBUTE,
 	FROM_HEX,
-	BT_ASSERT, BT_TEST_SUITE, BT_CHECK_ASSIGN, BT_TEST_SAME, FORMAT)
+	BT_ASSERT, BT_TEST_SUITE, BT_CHECK_ASSIGN, BT_TEST_SAME, SUBTLV, FORMAT)
 
 %nonassoc THEN
 %nonassoc ELSE
@@ -388,7 +520,7 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 %type <ecs> ec_kind
 %type <fret> break_command
 %type <i32> cnum
-%type <e> pair_item ec_item lc_item set_item switch_item ec_items set_items switch_items switch_body
+%type <e> pair_item ec_item lc_item set_item switch_item ec_items set_items switch_items switch_body sub_tlv_item
 %type <trie> fprefix_set
 %type <v> set_atom switch_atom fipa
 %type <px> fprefix
@@ -468,6 +600,8 @@ type:
  | ECLIST { $$ = T_ECLIST; }
  | LCLIST { $$ = T_LCLIST; }
  | ROUTE { $$ = T_ROUTE; }
+ | SUBTLV { $$ = T_SUBTLV; }
+ | TLVLIST { $$ = T_TLVLIST; }
  | type SET {
 	switch ($1) {
 	  case T_INT:
@@ -477,6 +611,7 @@ type:
 	  case T_LC:
 	  case T_RD:
 	  case T_IP:
+	  case T_SUBTLV:
 	       $$ = T_SET;
 	       break;
 
@@ -701,10 +836,16 @@ lc_item:
    { $$ = f_new_lc_item($2, $10, $4, $12, $6, $14); }
 ;
 
+sub_tlv_item:
+   '(' SUBTLV ',' cnum ',' term ')' { $$ = f_new_sub_tlv_item($4, $6); }
+ | '(' SUBTLV ',' cnum ',' cnum ',' term ')' { $$ = f_new_sub_tlv_item2($4, $6, $8); }
+ ;
+
 set_item:
    pair_item
  | ec_item
  | lc_item
+ | sub_tlv_item
  | set_atom { $$ = f_new_item($1, $1); }
  | set_atom DDOT set_atom { $$ = f_new_item($1, $3); }
  ;
@@ -713,6 +854,7 @@ switch_item:
    pair_item
  | ec_item
  | lc_item
+ | sub_tlv_item
  | switch_atom { $$ = f_new_item($1, $1); }
  | switch_atom DDOT switch_atom { $$ = f_new_item($1, $3); }
  ;
@@ -939,6 +1081,7 @@ term:
  | '-' EMPTY '-' { $$ = f_new_inst(FI_CONSTANT, val_empty(T_CLIST)); }
  | '-' '-' EMPTY '-' '-' { $$ = f_new_inst(FI_CONSTANT, val_empty(T_ECLIST)); }
  | '-' '-' '-' EMPTY '-' '-' '-' { $$ = f_new_inst(FI_CONSTANT, val_empty(T_LCLIST)); }
+ | '-' '-' '-' '-' EMPTY '-' '-' '-' '-' { $$ = f_new_inst(FI_CONSTANT, val_empty(T_TLVLIST)); }
 
  | PREPEND '(' term ',' term ')' { $$ = f_dispatch_method_x("prepend", $3->type, $3, $5); }
  | ADD '(' term ',' term ')' { $$ = f_dispatch_method_x("add", $3->type, $3, $5); }
diff --git a/filter/data.c b/filter/data.c
index 282206eb..adbd7795 100644
--- a/filter/data.c
+++ b/filter/data.c
@@ -8,6 +8,7 @@
  *
  */
 
+//#define LOCAL_DEBUG
 #include "nest/bird.h"
 #include "lib/lists.h"
 #include "lib/resource.h"
@@ -16,6 +17,7 @@
 #include "lib/unaligned.h"
 #include "lib/net.h"
 #include "lib/ip.h"
+#include "lib/tunnel_encaps.h"
 #include "nest/route.h"
 #include "nest/protocol.h"
 #include "nest/iface.h"
@@ -56,6 +58,8 @@ static const char * const f_type_str[] = {
   [T_ECLIST]	= "eclist",
   [T_LC]	= "lc",
   [T_LCLIST]	= "lclist",
+  [T_SUBTLV]	= "subtlv",
+  [T_TLVLIST]	= "tlvlist",
   [T_RD]	= "rd",
 
   [T_ROUTE] = "route",
@@ -90,7 +94,7 @@ f_type_element_type(enum f_type t)
 const struct f_trie f_const_empty_trie = { .ipv4 = -1, };
 const struct f_val f_const_empty_prefix_set = {
   .type = T_PREFIX_SET,
-  .val.ti = &f_const_empty_trie,
+  .val.ti = &f_const_empty_trie
 };
 
 static struct adata *
@@ -310,6 +314,8 @@ val_same(const struct f_val *v1, const struct f_val *v2)
     return v1->val.rte == v2->val.rte;
   case T_ROUTES_BLOCK:
     return v1->val.ad == v2->val.ad;
+  case T_TLVLIST:
+    return tlvlist_same(v1->val.tl, v2->val.tl);
   default:
     bug("Invalid type in val_same(): %x", v1->type);
   }
@@ -416,6 +422,18 @@ lclist_match_set(const struct adata *list, const struct f_tree *set)
   return 0;
 }
 
+static int
+tlvlist_match_set(const struct adata *list, const struct f_tree *set)
+{
+  if (!list)
+    return 0;
+
+  if (!subtlv_set_type(set))
+    return F_CMP_ERROR;
+
+  return 1;
+}
+
 const struct adata *
 clist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos)
 {
@@ -517,6 +535,20 @@ lclist_filter(struct linpool *pool, const struct adata *list, const struct f_val
   return res;
 }
 
+#if 0
+const struct te_tlvlist *
+tlvlist_filter(struct linpool *pool, const struct te_tlvlist *list, const struct f_val *set, int pos)
+{
+  if (!list)
+    return NULL;
+
+  /* FIXME */
+
+  return NULL;
+}
+#endif
+
+
 /**
  * val_in_range - implement |~| operator
  * @v1: element
@@ -577,6 +609,9 @@ val_in_range(const struct f_val *v1, const struct f_val *v2)
   if (v1->type == T_LCLIST)
     return lclist_match_set(v1->val.ad, v2->val.t);
 
+  if (v1->type == T_TLVLIST)
+    return tlvlist_match_set(v1->val.ad, v2->val.t);
+
   if (v1->type == T_PATH)
     return as_path_match_set(v1->val.ad, v2->val.t);
 
@@ -641,6 +676,7 @@ val_format(const struct f_val *v, buffer *buf)
   case T_CLIST:	int_set_format(v->val.ad, 1, -1, buf2, 1000); buffer_print(buf, "(clist %s)", buf2); return;
   case T_ECLIST: ec_set_format(v->val.ad, -1, buf2, 1000); buffer_print(buf, "(eclist %s)", buf2); return;
   case T_LCLIST: lc_set_format(v->val.ad, -1, buf2, 1000); buffer_print(buf, "(lclist %s)", buf2); return;
+  case T_TLVLIST: tlv_set_format(v->val.tl, -1, buf2, 1000); buffer_print(buf, "(tlvlist %s)", buf2); return;
   case T_PATH_MASK: pm_format(v->val.path_mask, buf); return;
   case T_ROUTE: rte_format(v->val.rte, buf); return;
   case T_ROUTES_BLOCK: rte_block_format(v->val.rte, buf); return;
diff --git a/filter/data.h b/filter/data.h
index 028640bb..bd96bbff 100644
--- a/filter/data.h
+++ b/filter/data.h
@@ -65,6 +65,8 @@ enum f_type {
   T_RD = 0x2a,		/* Route distinguisher for VPN addresses */
   T_PATH_MASK_ITEM = 0x2b,	/* Path mask item for path mask constructors */
   T_BYTESTRING = 0x2c,
+  T_SUBTLV = 0x2d,	/* Tunnel encapsulation sub-TLV */
+  T_TLVLIST = 0x2e,	/* Tunnel encapsulation TLV list */
 
   T_ROUTE = 0x78,
   T_ROUTES_BLOCK = 0x79,
@@ -97,6 +99,9 @@ struct f_val {
     const struct f_path_mask *path_mask;
     struct f_path_mask_item pmi;
     struct rte *rte;
+    struct te_subtlv st;
+    const struct te_tlv *tlv;
+    const struct te_tlvlist *tl;
   } val;
 };
 
@@ -317,6 +322,8 @@ static inline int lclist_set_type(const struct f_tree *set)
 { return !set || set->from.type == T_LC; }
 static inline int path_set_type(const struct f_tree *set)
 { return !set || set->from.type == T_INT; }
+static inline int subtlv_set_type(const struct f_tree *set)
+{ return !set || set->from.type == T_SUBTLV; }
 
 int clist_match_set(const struct adata *clist, const struct f_tree *set);
 int eclist_match_set(const struct adata *list, const struct f_tree *set);
@@ -325,6 +332,7 @@ int lclist_match_set(const struct adata *list, const struct f_tree *set);
 const struct adata *clist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 const struct adata *eclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 const struct adata *lclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
+const struct te_tlvlist *tlvlist_filter(struct linpool *pool, const struct te_tlvlist *list, const struct f_val *set, int pos);
 
 
 /* Special undef value for paths and clists */
@@ -349,6 +357,9 @@ val_empty(enum f_type t)
   case T_EMPTY_LIST:
     return (struct f_val) { .type = t, .val.ad = &null_adata };
 
+  case T_TLVLIST:
+    return (struct f_val) { .type = T_TLVLIST, .val.tl = NULL };
+
   default:
     return (struct f_val) { };
   }
diff --git a/filter/decl.m4 b/filter/decl.m4
index fec1d8df..16b66272 100644
--- a/filter/decl.m4
+++ b/filter/decl.m4
@@ -603,6 +603,9 @@ f_const_promotion_(struct f_inst *arg, enum f_type want, int update)
   } else if ((c->type == T_EMPTY_LIST) && (want == T_LCLIST)) {
     *c = val_empty(T_LCLIST);
     return 1;
+  } else if ((c->type == T_EMPTY_LIST) && (want == T_TLVLIST)) {
+    *c = val_empty(T_TLVLIST);
+    return 1;
   }
 
   return 0;
diff --git a/filter/f-inst.c b/filter/f-inst.c
index bebd13c5..df7ca7aa 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -904,6 +904,14 @@
       case EAF_TYPE_STRING:
 	RESULT_(T_STRING, s, (const char *) e->u.ptr->data);
 	break;
+      case EAF_TYPE_TUNNEL_ENCAP:
+	{
+	  struct te_tlvlist *decoded_tl = tlvlist_decode_tunnel_encap(fpool, e->u.ptr);
+	  if (!decoded_tl)
+	    runtime( "Tunnel encapsulation decoder error" );
+	  RESULT_(T_TLVLIST, tl, decoded_tl);
+	  break;
+	}
       default:
 	bug("Unknown dynamic attribute type");
       }
@@ -976,6 +984,16 @@
 	}
 	break;
 
+      case EAF_TYPE_TUNNEL_ENCAP:
+	{
+	  if (v1.type != T_TLVLIST)
+	    runtime( "Setting tunnel encap attribute to non-tlvlist value %d", v1.type );
+	  l->attrs[0].u.ptr = tlvlist_encode_tunnel_encap(fpool, v1.val.tl);
+	  if (!l->attrs[0].u.ptr)
+	    runtime( "Tunnel encapsulation encoder error" );
+	  break;
+	}
+
       default:
 	bug("Unknown dynamic attribute type");
       }
@@ -1366,6 +1384,24 @@
     RESULT(T_LCLIST, ad, [[ lc_set_union(fpool, v1.val.ad, v2.val.ad) ]]);
   }
 
+  INST(FI_TLVLIST_ADD_SET, 2, 1) {
+    ARG(1, T_TLVLIST);
+    ARG(2, T_SET);
+    METHOD_CONSTRUCTOR("add");
+
+    if (!subtlv_set_type(v2.val.t))
+      runtime("Mismatched set type");
+
+    RESULT(T_TLVLIST, tl, [[ tlv_set_add(fpool, v1.val.tl, tlv_alloc(fpool, v2.val.t)) ]]);
+  }
+
+  INST(FI_TLVLIST_ADD_TLVLIST, 2, 1) {
+    ARG(1, T_TLVLIST);
+    ARG(2, T_TLVLIST);
+    METHOD_CONSTRUCTOR("add");
+    RESULT(T_TLVLIST, tl, [[ tlv_set_union(fpool, v1.val.tl, v2.val.tl) ]]);
+  }
+
   INST(FI_PATH_DELETE_INT, 2, 1) {
     ARG(1, T_PATH);
     ARG(2, T_INT);
@@ -1489,6 +1525,21 @@
     RESULT(T_LCLIST, ad, [[ lclist_filter(fpool, v1.val.ad, &v2, 0) ]]);
   }
 
+  INST(FI_TLVLIST_DELETE_SET, 2, 1) {
+    ARG(1, T_TLVLIST);
+    ARG(2, T_SET);
+    METHOD_CONSTRUCTOR("delete");
+
+    if (!subtlv_set_type(v2.val.t))
+      runtime("Mismatched set type");
+
+#if 0
+    RESULT(T_TLVLIST, tl, [[ tlvlist_filter(fpool, v1.val.tl, &v2, 0) ]]);
+#else
+    runtime("FI_TLVLIST_DELETE_SET disabled");
+#endif
+  }
+
   INST(FI_PATH_FILTER_SET, 2, 1) {
     ARG(1, T_PATH);
     ARG(2, T_SET);
@@ -1554,6 +1605,33 @@
     RESULT(T_LCLIST, ad, [[ lclist_filter(fpool, v1.val.ad, &v2, 1) ]]);
   }
 
+  INST(FI_TLVLIST_FILTER_SET, 2, 1) {
+    ARG(1, T_TLVLIST);
+    ARG(2, T_SET);
+    METHOD_CONSTRUCTOR("filter");
+
+    if (!subtlv_set_type(v2.val.t))
+      runtime("Mismatched set type");
+
+#if 0
+    RESULT(T_TLVLIST, tl, [[ tlvlist_filter(fpool, v1.val.tl, &v2, 1) ]]);
+#else
+    runtime("FI_TLVLIST_FILTER_SET disabled");
+#endif
+  }
+
+  INST(FI_TLVLIST_FILTER_TLVLIST, 2, 1) {
+    ARG(1, T_TLVLIST);
+    ARG(2, T_TLVLIST);
+    METHOD_CONSTRUCTOR("filter");
+
+#if 0
+    RESULT(T_TLVLIST, tl, [[ tlvlist_filter(fpool, v1.val.tl, &v2, 1) ]]);
+#else
+    runtime("FI_TLVLIST_FILTER_TLVLIST disabled");
+#endif
+  }
+
   INST(FI_ROA_CHECK_IMPLICIT, 0, 1) {	/* ROA Check */
     NEVER_CONSTANT;
     RTC(1);
diff --git a/lib/Makefile b/lib/Makefile
index 0310eca2..1534b794 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,4 +1,4 @@
-src := base64.c bitmap.c bitops.c blake2s.c blake2b.c checksum.c event.c flowspec.c idm.c ip.c lists.c mac.c md5.c mempool.c net.c patmatch.c printf.c resource.c sha1.c sha256.c sha512.c slab.c slists.c strtoul.c tbf.c timer.c xmalloc.c
+src := base64.c bitmap.c bitops.c blake2s.c blake2b.c checksum.c event.c flowspec.c idm.c ip.c lists.c mac.c md5.c mempool.c net.c patmatch.c printf.c resource.c sha1.c sha256.c sha512.c slab.c slists.c strtoul.c tbf.c timer.c tunnel_encaps.c xmalloc.c
 obj := $(src-o-files)
 $(all-daemon)
 
diff --git a/lib/tunnel_encaps.c b/lib/tunnel_encaps.c
new file mode 100644
index 00000000..d549694a
--- /dev/null
+++ b/lib/tunnel_encaps.c
@@ -0,0 +1,876 @@
+#define LOCAL_DEBUG
+
+#include <stdlib.h>
+#include "lib/tunnel_encaps.h"
+
+struct format_fn {
+  node n;
+  int type;
+  const char *name;
+  format_tunnel_encap_fn cb;
+};
+
+list format_fns;
+
+static format_tunnel_encap_fn lookup_format_tunnel_encap_cb(int type);
+static const char *lookup_format_tunnel_encap_name(int type);
+static int default_format_tunnel_encap(const struct te_encap *encap, byte *buf, uint size);
+
+static
+int walk_encap(const void *p, size_t sub_tlv_len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  struct te_encap encap;
+  memset(&encap, 0, sizeof(encap));
+
+  encap.type = 0;
+  encap.length = sub_tlv_len;
+  encap.data = (void *)p;
+  return visitor->visit_encap ? visitor->visit_encap(&encap, ctx) : 0;
+}
+
+static
+int walk_color(const void *p, size_t sub_tlv_len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  if (sub_tlv_len != 8)
+  {
+    DBG(L_TRACE "WG: color len error %d", sub_tlv_len);
+    return -1;
+  }
+
+  if (get_u16(p) != 0x030b)
+  {
+    DBG(L_TRACE "WG: color error %04x", get_u16(p));
+    return -1;
+  }
+
+  return visitor->visit_color ? visitor->visit_color(get_u32(p+4), ctx) : 0;
+}
+
+static
+int walk_udp_dest_port(const void *p, size_t sub_tlv_len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  if (sub_tlv_len != 2)
+  {
+    DBG(L_TRACE "WG: udp dest port len error %d", sub_tlv_len);
+    return -1;
+  }
+
+  return visitor->visit_udp_dest_port ? visitor->visit_udp_dest_port(get_u16(p), ctx) : 0;
+}
+
+static
+int walk_tunnel_ep(const void *p, size_t sub_tlv_len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  if (sub_tlv_len < 6)
+  {
+    DBG(L_TRACE "WG: tunnel ep len error");
+    return -1;
+  }
+
+  struct te_endpoint ep;
+  memset(&ep, 0, sizeof(ep));
+
+  ep.reserved = get_u32(p);
+  u16 af = get_u16(p + 4);
+  ep.af = af;
+  switch (af)
+  {
+  case 0:
+    if (sub_tlv_len != 6)
+    {
+      DBG(L_TRACE "WG: Fam 0 len error %d", sub_tlv_len);
+      return -1;
+    }
+    ep.ip = IP6_NONE;
+    break;
+  case AFI_IPV4:
+    if (sub_tlv_len != 10)
+    {
+      DBG(L_TRACE "WG: IPv4 len error %d", sub_tlv_len);
+      return -1;
+    }
+    ep.ip = ipa_from_ip4(get_ip4(p + 6));
+    break;
+  case AFI_IPV6:
+    if (sub_tlv_len != 22)
+    {
+      DBG(L_TRACE "WG: IPv6 len error %d", sub_tlv_len);
+      return -1;
+    }
+    ep.ip = ipa_from_ip6(get_ip6(p + 6));
+    break;
+  default:
+    DBG(L_TRACE "WG: Address family error %d", af);
+    return -1;
+  }
+
+  return visitor->visit_ep ? visitor->visit_ep(&ep, ctx) : 0;
+}
+
+static
+int walk_unknown(const void *p, int type, size_t sub_tlv_len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  struct te_unknown unknown;
+  memset(&unknown, 0, sizeof(unknown));
+
+  unknown.length = sub_tlv_len;
+  unknown.data = (void *)p;
+  return visitor->visit_unknown ? visitor->visit_unknown(type, &unknown, ctx) : 0;
+}
+
+static
+int walk_sub_tlv(const u8 *p, size_t len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  if (len < 2)
+  {
+    DBG(L_TRACE "WG: sub_tlv len error %d", len);
+    return -1;
+  }
+
+  const u8 *first = p;
+  const u8 *last = p + len;
+  int type = get_u8(p++);
+  u16 sub_tlv_len = 0;
+
+  if (type >= 0 && type <= 127)
+  {
+    sub_tlv_len = get_u8(p);
+    p++;
+  }
+  else if (type >= 128 && type <= 255)
+  {
+    if (len < 3)
+    {
+      DBG(L_TRACE "WG: sub_tlv len error %d", len);
+      return -1;
+    }
+
+    sub_tlv_len = get_u16(p);
+    p += 2;
+  }
+  else
+  {
+    DBG(L_TRACE "WG: sub_tlv type error %d", type);
+    return -1;
+  }
+
+  if (p + sub_tlv_len > last)
+  {
+    DBG(L_TRACE "WG: sub_tlv value len error %d", sub_tlv_len);
+    return -1;
+  }
+
+  if (visitor->visit_subtlv && visitor->visit_subtlv(type, ctx) < 0)
+    return p - first + sub_tlv_len;
+
+  int res = 0;
+
+  switch (type)
+  {
+  case BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP:
+    res = walk_encap(p, sub_tlv_len, visitor, ctx);
+    break;
+  case BGP_TUNNEL_ENCAP_A_SUB_TLV_TUNNEL_EP:
+    res = walk_tunnel_ep(p, sub_tlv_len, visitor, ctx);
+    break;
+  case BGP_TUNNEL_ENCAP_A_SUB_TLV_COLOR:
+    res = walk_color(p, sub_tlv_len, visitor, ctx);
+    break;
+  case BGP_TUNNEL_ENCAP_A_SUB_TLV_UDP_DEST_PORT:
+    res = walk_udp_dest_port(p, sub_tlv_len, visitor, ctx);
+    break;
+  default:
+    res = walk_unknown(p, type, sub_tlv_len, visitor, ctx);
+    break;
+  }
+
+  if (res < 0)
+  {
+    DBG(L_TRACE "WG: Decode error");
+    return res;
+  }
+
+  /* TODO use return value? */
+  if (visitor->visit_subtlv_end)
+    visitor->visit_subtlv_end(type, ctx);
+
+  return p - first + sub_tlv_len;
+}
+
+static
+int walk_sub_tlvs(const u8 *p, size_t size, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  const u8 *pos = p;
+
+  while (size > 0)
+  {
+    int l = walk_sub_tlv(pos, size, visitor, ctx);
+
+    if (l < 0)
+    {
+      DBG(L_TRACE "WG: decode error %d", l);
+      return l;
+    }
+
+    ADVANCE(pos, size, l);
+  }
+
+  return pos - p;
+}
+
+static
+int walk_tlv(const u8 *p, size_t len, const struct te_visitor *visitor, struct te_context *ctx)
+{
+  const u8 *pos = p;
+  int l;
+
+  if (len < 4)
+  {
+    DBG(L_TRACE "WG: tunnel_encap len error %d", len);
+    return -1;
+  }
+
+  u16 type = get_u16(pos);
+  ADVANCE(pos, len, 2);
+
+  u16 value_length = get_u16(pos);
+  ADVANCE(pos, len, 2);
+
+  if (len < value_length)
+  {
+    DBG(L_ERR "WG: tunnel encap len error %d", value_length);
+    return -1;
+  }
+
+  ctx->sub_tlvs_pos = pos;
+  ctx->sub_tlvs_len = value_length;
+
+  if (visitor->visit_tlv && visitor->visit_tlv(type, ctx) < 0)
+    return 0;
+
+  l = walk_sub_tlvs(pos, value_length,  visitor, ctx);
+  if (l < 0)
+  {
+    DBG(L_ERR "WG: sub-TLVs decode error");
+    return l;
+  }
+
+  if (l != value_length)
+  {
+    DBG(L_ERR "WG: TLV length error");
+    return -1;
+  }
+
+  ADVANCE(pos, len, l);
+
+  if (visitor->visit_tlv_end && visitor->visit_tlv_end(ctx) < 0)
+    return 0;
+
+  ctx->sub_tlvs_pos = NULL;
+  ctx->sub_tlvs_len = 0;
+
+  return pos - p;
+}
+
+int walk_tunnel_encap(const struct adata *a, const struct te_visitor *visitor, void *opaque)
+{
+  const u8 *p = a->data;
+  const u8 *pos = p;
+  uint size = a->length;
+  struct te_context ctx = { .opaque = opaque, };
+
+  while (size > 0)
+  {
+    int l = walk_tlv(p, size, visitor, &ctx);
+
+    if (l < 0)
+    {
+      DBG(L_ERR "WG: TLV decode error");
+      return l;
+    }
+
+    ADVANCE(pos, size, l);
+  }
+
+  return 0;
+}
+
+struct count_subtlvs {
+  uint count;
+};
+
+static int
+visitor_count_subtlv(int UNUSED type, struct te_context *ctx){
+  struct count_subtlvs *data = ctx->opaque;
+
+  data->count++;
+  return 0;
+}
+
+int te_count_subtlvs(struct te_context *ctx)
+{
+  struct count_subtlvs data = { .count = 0, };
+  struct te_context new_ctx = { .opaque = &data, };
+  struct te_visitor visitor = { .visit_subtlv = visitor_count_subtlv, };
+
+  if (walk_sub_tlvs(ctx->sub_tlvs_pos, ctx->sub_tlvs_len, &visitor, &new_ctx) < 0)
+    return -1;
+
+  return data.count;
+}
+
+struct {
+  int type;
+  const char *name;
+} tunnel_types[] = {
+  {0, "Reserved"},
+  {1, "L2TPv3 over IP"},
+  {2, "GRE"},
+  {3, "Transmit tunnel endpoint (DEPRECATED)"},
+  {4, "IPsec in Tunnel-mode (DEPRECATED)"},
+  {5, "IP in IP tunnel with IPsec Transport Mode (DEPRECATED)"},
+  {6, "MPLS-in-IP tunnel with IPsec Transport Mode (DEPRECATED)"},
+  {7, "IP in IP"},
+  {8, "VXLAN Encapsulation"},
+  {9, "NVGRE Encapsulation"},
+  {10, "MPLS Encapsulation"},
+  {11, "MPLS in GRE Encapsulation"},
+  {12, "VXLAN GPE Encapsulation"},
+  {13, "MPLS in UDP Encapsulation"},
+  {14, "IPv6 Tunnel"},
+  {15, "SR TE Policy Type"},
+  {16, "Bare"},
+  {17, "SR Tunnel (DEPRECATED)"},
+  {18, "Cloud Security"},
+  {19, "Geneve Encapsulation"},
+  {20, "Any-Encapsulation"},
+  {21, "GTP Tunnel Type"},
+  {22, "Dynamic Path Selection (DPS) Tunnel Encapsulation"},
+  {23, "Originating PE (OPE)"},
+  {24, "Dynamic Path Selection (DPS) Policy"},
+};
+
+const uint num_tunnel_types = sizeof(tunnel_types)/sizeof(tunnel_types[0]);
+
+static const char *
+lookup_name(int type)
+{
+  for (uint i = 0; i < num_tunnel_types; i++)
+  {
+    if (tunnel_types[i].type == type)
+      return tunnel_types[i].name;
+  }
+
+  const char *name = lookup_format_tunnel_encap_name(type);
+  return name ? name : "Unassigned";
+}
+
+static int visitor_format_tlv(int type, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  const char *name = lookup_name(type);
+
+  int l = bsnprintf(buf->pos, buf->size, "%s{type: %s(%d)", buf->tlv?"}, ":"", name, type);
+  if (l < 0)
+  {
+    DBG(L_ERR "WG: bsnprintf error");
+    return -1;
+  }
+
+  buf->tlv++;
+  buf->tlv_type = type;
+  buf->subtlv=0;
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_subtlv(int UNUSED type, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+
+  int l = bsnprintf(buf->pos, buf->size, ", ");
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_encap(const struct te_encap *encap, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  int l = bsnprintf(buf->pos, buf->size, "encap: ");
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+
+  l = lookup_format_tunnel_encap_cb(buf->tlv_type)(encap, buf->pos, buf->size);
+  if (l < 0)
+    l = default_format_tunnel_encap(encap, buf->pos, buf->size);
+
+  if (l < 0)
+  {
+    DBG(L_ERR "WG: Encapsulation format error");
+    return l;
+  }
+
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_ep(const struct te_endpoint *ep, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  int l =  bsnprintf(buf->pos, buf->size, "ep: %I", ep->ip);
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_color(u32 color, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  int l = bsnprintf(buf->pos, buf->size, "color: %d", color);
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_udp_dest_port(u16 udp_dest_port, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  int l = bsnprintf(buf->pos, buf->size, "udp: %d", udp_dest_port);
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+  return 0;
+}
+
+static int visitor_format_unknown(int type, const struct te_unknown *unknown, struct te_context *ctx)
+{
+  struct te_buffer *buf = ctx->opaque;
+  const byte *data = unknown->data;
+  int l = bsnprintf(buf->pos, buf->size, "unknown(%d): ", type);
+  if (l < 0)
+    return -1;
+  ADVANCE(buf->pos, buf->size, l);
+
+  int first = 1;
+  for (uint i = 0; i < unknown->length; i++)
+  {
+    if (buf->size < 4) {
+      DBG(L_ERR "WG: Format unknown sub-TLV error");
+      return -1;
+    }
+
+    int l = bsnprintf(buf->pos, buf->size, "%s%02x", first?"":" ", data[i]);
+    ADVANCE(buf->pos, buf->size, l);
+    first = 0;
+  }
+
+  return 0;
+}
+
+struct te_visitor format_visitor =
+{
+  .visit_tlv = visitor_format_tlv,
+  .visit_subtlv = visitor_format_subtlv,
+  .visit_encap = visitor_format_encap,
+  .visit_ep = visitor_format_ep,
+  .visit_color = visitor_format_color,
+  .visit_udp_dest_port = visitor_format_udp_dest_port,
+  .visit_unknown = visitor_format_unknown,
+};
+
+const struct te_visitor *te_get_format_visitor(void)
+{
+  return &format_visitor;
+}
+
+int format_tunnel_encap(const struct adata *a, byte *buf, uint size)
+{
+  struct te_buffer buffer = {.pos=buf, .size=size, .tlv=0, .subtlv=0};
+  int l = bsnprintf(buffer.pos, buffer.size, "[");
+  if (l < 0)
+    return -1;
+  ADVANCE(buffer.pos, buffer.size, l);
+
+  walk_tunnel_encap(a, &format_visitor, &buffer);
+
+  l = bsnprintf(buffer.pos, buffer.size, "%s]", buffer.tlv?"}":"");
+  if (l < 0)
+    return -1;
+  ADVANCE(buffer.pos, buffer.size, l);
+  return buffer.pos - buf;
+}
+
+static int default_format_tunnel_encap(const struct te_encap *encap, byte *buf, uint size)
+{
+  byte *pos = buf;
+  const byte *data = encap->data;
+  int first = 1;
+
+  for (uint i = 0; i < encap->length; i++)
+  {
+    if (size < 4) {
+      DBG(L_ERR "WG: Default format tunnel encap error");
+      return pos - buf;
+    }
+
+    int l = bsnprintf(pos, size, "%s%02x", first?"":" ", data[i]);
+    ADVANCE(pos, size, l);
+
+    first = 0;
+  }
+
+  return pos - buf;
+}
+
+static struct format_fn *lookup_format_tunnel_encap(int type)
+{
+  struct format_fn *n;
+  WALK_LIST(n, format_fns) {
+    if (n->type == type)
+      return n;
+  }
+
+  return NULL;
+}
+
+static const char *lookup_format_tunnel_encap_name(int type)
+{
+  struct format_fn *fn = lookup_format_tunnel_encap(type);
+
+  if (fn && fn->name)
+    return fn->name;
+
+  return NULL;
+}
+
+static format_tunnel_encap_fn lookup_format_tunnel_encap_cb(int type)
+{
+  struct format_fn *fn = lookup_format_tunnel_encap(type);;
+
+  if (fn && fn->cb)
+    return fn->cb;
+
+  DBG("lookup_format_tunnel_encap not found: %d\n", type);
+  return default_format_tunnel_encap;
+}
+
+struct tlv_buffer {
+  uint len;
+  uint size;
+  byte *p;
+  byte *tlv_len_p;
+  byte *subtlv_len_p;
+};
+
+static int calc_tlv(int type, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+      Header:
+      Tunnel Type (2 Octets)
+      Length (2 Octets)
+      Value (Variable)
+  */
+  buf->len += 4;
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  if (type <= 0 || type > 65535)
+    return -1;
+
+  put_u16(buf->p, type);
+  buf->p += 2;
+
+  buf->tlv_len_p = buf->p;
+
+  put_u16(buf->p, 0xcccc);		/* Update in calc_tlv_end */
+  buf->p += 2;
+  return 0;
+}
+
+static int calc_tlv_end(struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+
+  if (!buf->size)
+    return 0;
+
+  if (!buf->tlv_len_p)
+    return -1;
+
+  put_u16(buf->tlv_len_p, buf->p - buf->tlv_len_p - 2);
+  buf->tlv_len_p = NULL;
+  return 0;
+}
+
+static int calc_subtlv(int type, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Type (1 Octet)
+    Sub-TLV Length (1 or 2 Octets)
+  */
+  if (type >= 0 && type <= 127)
+    buf->len += 2;
+  else if (type >= 128 && type <= 255)
+    buf->len += 3;
+  else
+  {
+    DBG(L_ERR "calc_subtlv bad type %d\n", type );
+    return -1;
+  }
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  put_u8(buf->p, type);
+  buf->p++;
+
+  buf->subtlv_len_p = buf->p;
+
+  if (type >= 0 && type <= 127)
+  {
+    put_u8(buf->p, 0xdd);	/* Update in calc_subtlv_end */
+    buf->p++;
+  }
+  else
+  {
+    put_u16(buf->p, 0xeeee);	/* Update in calc_subtlv_end */
+    buf->p += 2;
+  }
+
+  return 0;
+}
+
+static int calc_subtlv_end(int type, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+
+  if (!buf->size)
+    return 0;
+
+  if (!buf->subtlv_len_p)
+    return -1;
+
+  if (type >= 0 && type <= 127)
+  {
+    put_u8(buf->subtlv_len_p, buf->p - buf->subtlv_len_p - 1);
+    buf->subtlv_len_p = NULL;
+  }
+  else if (type >= 128 && type <= 255)
+  {
+    put_u16(buf->subtlv_len_p, buf->p - buf->subtlv_len_p - 2);
+    buf->subtlv_len_p = NULL;
+  }
+  else
+    return -1;
+
+  return 0;
+}
+
+static int calc_encap(const struct te_encap *encap, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Value (Variable)
+   */
+  if (encap->type <= 0)
+  {
+    DBG(L_ERR "calc_encap bad type %d\n", encap->type );
+    return -1;
+  }
+
+  buf->len += encap->length;
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  memcpy(buf->p, encap->data, encap->length);
+  buf->p += encap->length;
+  return 0;
+}
+
+static int calc_ep(const struct te_endpoint *ep, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Value (10 or 22 Octets)
+  */
+  if (ep->af == AFI_IPV4 && ipa_is_ip4(ep->ip))
+    buf->len += 10;
+  else if (ep->af == AFI_IPV6 && ipa_is_ip6(ep->ip))
+    buf->len += 22;
+  else if (ep->af == 0)
+    buf->len += 6;
+  else
+  {
+    DBG(L_ERR "calc_encap bad af %04x\n", ep->af );
+    return -1;
+  }
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  put_u32(buf->p, ep->reserved);
+  buf->p += 4;
+
+  put_u16(buf->p, ep->af);
+  buf->p += 2;
+
+  switch (ep->af)
+  {
+  case AFI_IPV4:
+    put_ip4(buf->p, ipa_to_ip4(ep->ip));
+    buf->p += 4;
+    break;
+  case AFI_IPV6:
+    put_ip6(buf->p, ipa_to_ip6(ep->ip));
+    buf->p += 16;
+    break;
+  default:
+    break;
+  }
+
+  return 0;
+}
+
+static int calc_color(u32 color, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Value (8 Octets)
+  */
+  buf->len += 8;
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  put_u32(buf->p, 0x030b0000);
+  buf->p += 4;
+
+  put_u32(buf->p, color);
+  buf->p += 4;
+  return 0;
+}
+
+static int calc_udp_dest_port(u16 UNUSED udp_dest_port, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Value (2 Octets)
+  */
+  buf->len += 2;
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  put_u16(buf->p, udp_dest_port);
+  buf->p += 2;
+  return 0;
+}
+
+static int calc_unknown(int UNUSED type, const struct te_unknown *unknown, struct te_context *ctx)
+{
+  struct tlv_buffer *buf = ctx->opaque;
+  /*
+    Sub-TLV Value (Variable)
+   */
+
+  buf->len += unknown->length;
+
+  if (!buf->size)
+    return 0;
+
+  if (buf->len > buf->size)
+    return -1;
+
+  memcpy(buf->p, unknown->data, unknown->length);
+  buf->p += unknown->length;
+  return 0;
+}
+
+struct te_visitor encode_visitor =
+{
+  .visit_tlv = calc_tlv,
+  .visit_tlv_end = calc_tlv_end,
+  .visit_subtlv = calc_subtlv,
+  .visit_subtlv_end = calc_subtlv_end,
+  .visit_encap = calc_encap,
+  .visit_ep = calc_ep,
+  .visit_color = calc_color,
+  .visit_udp_dest_port = calc_udp_dest_port,
+  .visit_unknown = calc_unknown,
+};
+
+const struct te_visitor *te_get_encode_visitor(void)
+{
+  return &encode_visitor;
+}
+
+int te_init_encode_visitor(struct tlv_buffer *buf, byte *p, uint size)
+{
+  if (!buf)
+    return sizeof(struct te_buffer);
+
+  memset(buf, 0, sizeof(struct te_buffer));
+  buf->size = size;
+  buf->p = p;
+
+  return 0;
+}
+
+uint te_get_encode_length(struct tlv_buffer *buf)
+{
+  return buf->len;
+}
+
+void register_format_tunnel_encap(int type, const char *name, format_tunnel_encap_fn cb)
+{
+  struct format_fn *fn = malloc(sizeof(struct format_fn));
+  memset(fn, 0, sizeof(*fn));
+  fn->type = type;
+  fn->name = name;
+  fn->cb = cb;
+  add_head(&format_fns, &fn->n);
+}
+
+void unregister_format_tunnel_encap(int type, format_tunnel_encap_fn cb)
+{
+  struct format_fn *n, *nxt;
+  WALK_LIST_DELSAFE(n, nxt, format_fns)
+  {
+    if (n->type == type && n->cb == cb)
+    {
+      rem_node(&n->n);
+    }
+  }
+}
+
+void tunnel_encap_init()
+{
+  init_list(&format_fns);
+}
diff --git a/lib/tunnel_encaps.h b/lib/tunnel_encaps.h
new file mode 100644
index 00000000..fc7bbda6
--- /dev/null
+++ b/lib/tunnel_encaps.h
@@ -0,0 +1,63 @@
+#ifndef _BIRD_TUNNEL_ENCAPS_
+#define _BIRD_TUNNEL_ENCAPS_
+
+#include "nest/attrs.h"
+#include "nest/route.h"
+
+#define BA_TUNNEL_ENCAP		0x17
+
+#define BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP         1
+#define BGP_TUNNEL_ENCAP_A_SUB_TLV_COLOR         4
+#define BGP_TUNNEL_ENCAP_A_SUB_TLV_TUNNEL_EP     6
+#define BGP_TUNNEL_ENCAP_A_SUB_TLV_UDP_DEST_PORT 8
+
+#define FLAG_BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP         (1<<BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP)
+#define FLAG_BGP_TUNNEL_ENCAP_A_SUB_TLV_COLOR         (1<<BGP_TUNNEL_ENCAP_A_SUB_TLV_COLOR)
+#define FLAG_BGP_TUNNEL_ENCAP_A_SUB_TLV_TUNNEL_EP     (1<<BGP_TUNNEL_ENCAP_A_SUB_TLV_TUNNEL_EP)
+#define FLAG_BGP_TUNNEL_ENCAP_A_SUB_TLV_UDP_DEST_PORT (1<<BGP_TUNNEL_ENCAP_A_SUB_TLV_UDP_DEST_PORT)
+
+struct te_context {
+  void *opaque;
+  const byte *sub_tlvs_pos;
+  uint sub_tlvs_len;
+};
+
+struct te_visitor {
+  int (*visit_tlv)(int type, struct te_context *ctx);
+  int (*visit_tlv_end)(struct te_context *ctx);
+  int (*visit_subtlv)(int type, struct te_context *ctx);
+  int (*visit_subtlv_end)(int type, struct te_context *ctx);
+  int (*visit_encap)(const struct te_encap *encap, struct te_context *ctx);
+  int (*visit_ep)(const struct te_endpoint *ep, struct te_context *ctx);
+  int (*visit_color)(u32 color, struct te_context *ctx);
+  int (*visit_udp_dest_port)(u16 port, struct te_context *ctx);
+  int (*visit_unknown)(int type, const struct te_unknown *unknown, struct te_context *ctx);
+};
+
+struct te_buffer {
+  byte *pos;
+  uint size;
+  int tlv;
+  int tlv_type;
+  int subtlv;
+};
+
+struct tlv_buffer;
+
+typedef int (*format_tunnel_encap_fn)(const struct te_encap *, byte *buf, uint size);
+
+void tunnel_encap_init(void);
+int walk_tunnel_encap(const struct adata *a, const struct te_visitor *visitor, void *opaque);
+int te_count_subtlvs(struct te_context *ctx);
+
+const struct te_visitor *te_get_format_visitor(void);
+int format_tunnel_encap(const struct adata *a, byte *buf, uint size);
+
+const struct te_visitor *te_get_encode_visitor(void);
+int te_init_encode_visitor(struct tlv_buffer *buf, byte *p, uint size);
+uint te_get_encode_length(struct tlv_buffer *buf);
+
+void register_format_tunnel_encap(int type, const char *name, format_tunnel_encap_fn cb);
+void unregister_format_tunnel_encap(int type, format_tunnel_encap_fn cb);
+
+#endif	/* _BIRD_TUNNEL_ENCAPS_ */
diff --git a/lib/unaligned.h b/lib/unaligned.h
index dfe0906f..0d3c83f9 100644
--- a/lib/unaligned.h
+++ b/lib/unaligned.h
@@ -17,8 +17,9 @@
  *  if possible.
  */
 
+#include <memory.h>
+#include "sysdep/config.h"
 #include "sysdep/unix/endian.h"
-#include "lib/string.h"
 
 static inline u8
 get_u8(const void *p)
diff --git a/nest/Makefile b/nest/Makefile
index ef0fdf67..aa75fed7 100644
--- a/nest/Makefile
+++ b/nest/Makefile
@@ -1,4 +1,4 @@
-src := a-path.c a-set.c cli.c cmds.c iface.c locks.c mpls.c neighbor.c password.c proto.c proto-build.c rt-attr.c rt-dev.c rt-fib.c rt-show.c rt-table.c
+src := a-path.c a-set.c a-tlv.c cli.c cmds.c iface.c locks.c mpls.c neighbor.c password.c proto.c proto-build.c rt-attr.c rt-dev.c rt-fib.c rt-show.c rt-table.c
 obj := $(src-o-files)
 $(all-daemon)
 $(cf-local)
diff --git a/nest/a-tlv.c b/nest/a-tlv.c
new file mode 100644
index 00000000..13e05f43
--- /dev/null
+++ b/nest/a-tlv.c
@@ -0,0 +1,421 @@
+#include "lib/tunnel_encaps.h"
+#include "filter/data.h"
+
+static int
+walk_tlvlist(const struct te_tlvlist *set, const struct te_visitor *visitor, void *opaque)
+{
+  if (!set)
+    return 0;
+
+  struct te_tlv *t;
+  struct te_context ctx = { .opaque = opaque, };
+
+  WALK_LIST(t, set->tlv)
+  {
+    if (visitor->visit_tlv && visitor->visit_tlv(t->type, &ctx) < 0)
+      continue;
+
+    for (uint j=0; j < t->len; j++)
+    {
+      const struct te_subtlv *st = &t->st[j];
+
+      if (visitor->visit_subtlv && visitor->visit_subtlv(st->type, &ctx) < 0)
+        continue;
+
+      switch (st->type)
+      {
+      case TLV_ENCAPSULATION:
+        if (visitor->visit_encap && visitor->visit_encap(&st->u.tunnel_encap, &ctx) < 0)
+          return -1;
+        break;
+      case TLV_COLOR:
+        if (visitor->visit_color && visitor->visit_color(st->u.color, &ctx) < 0)
+          return -1;
+        break;
+      case TLV_TUNNEL_ENDPOINT:
+        if (visitor->visit_ep && visitor->visit_ep(&st->u.tunnel_endpoint, &ctx) < 0)
+          return -1;
+        break;
+      case TLV_UDP_DEST_PORT:
+        if (visitor->visit_udp_dest_port && visitor->visit_udp_dest_port(st->u.udp_dest_port, &ctx) < 0)
+          return -1;
+        break;
+      default:
+        if (visitor->visit_unknown && visitor->visit_unknown(st->type, &st->u.unknown, &ctx) < 0)
+          return -1;
+        break;
+      }
+
+      if (visitor->visit_subtlv_end)
+        visitor->visit_subtlv_end(st->type, &ctx); /* TODO use return value? */
+    }
+
+    if (visitor->visit_tlv_end)
+      visitor->visit_tlv_end(&ctx); /* TODO use return value? */
+  }
+
+  return 0;
+}
+
+static void calc_elems(const struct f_tree UNUSED *t, void *ptr)
+{
+  uint *len = ptr;
+  (*len)++;
+}
+
+static void put_elems(const struct f_tree *t, void *ptr)
+{
+  struct te_tlv *tlv = ptr;
+  const struct te_subtlv *st = &t->from.val.st;
+  tlv->len--;
+  tlv->st[tlv->len] = *st;
+  if (st->type == TLV_ENCAPSULATION)
+    tlv->type = st->u.tunnel_encap.type;
+  DBG("put_elems: type %d\n", st->type);
+}
+
+const struct te_tlv *tlv_alloc(struct linpool *pool, const struct f_tree *set)
+{
+  uint len = 0;
+
+  tree_walk(set, calc_elems, &len);
+
+  if (!len)
+    return NULL;
+
+  struct te_tlv *res = lp_alloc(pool, sizeof(struct te_tlv) + len * sizeof(struct te_subtlv));
+
+  res->len = len;
+  tree_walk(set, put_elems, res);
+
+  res->len = len;		/* Len was reset during tree_walk. */
+
+  for (uint i=0; i < len; i++)
+  {
+    DBG("tlv_alloc: type[%d]: %d\n", i, res->st[i].type);
+  }
+  return res;
+}
+
+int tlv_set_format(const struct te_tlvlist *set, int UNUSED from, byte *buf, uint size)
+{
+  const struct te_visitor *visitor = te_get_format_visitor();
+  struct te_buffer buffer = {.pos=buf, .size=size, .tlv=0, .subtlv=0};
+
+  if (set)
+    walk_tlvlist(set, visitor, &buffer);
+
+  int l = bsnprintf(buffer.pos, buffer.size, "%s", buffer.tlv?"}":"<empty>");
+  if (l < 0)
+    return -1;
+  ADVANCE(buffer.pos, buffer.size, l);
+  return buffer.pos - buf;
+}
+
+int
+tlv_set_contains(const struct te_tlvlist *list, const struct te_tlv UNUSED *val)
+{
+  if (!list)
+    return 0;
+
+  /* FIXME */
+  return 0;
+}
+
+static void tlv_add_copy(struct linpool *pool, struct te_tlvlist *list, const struct te_tlv *t)
+{
+  uint size = sizeof(struct te_tlv) + t->len * sizeof(struct te_subtlv);
+  struct te_tlv *tlv = lp_alloc(pool, size);
+  memcpy(tlv, t, size);
+  memset(&tlv->n, 0, sizeof(tlv->n));
+  add_tail(&list->tlv, &tlv->n);
+  DBG("tlv_add_copy: src type %d, dst type %d\n", t->st[0].type, tlv->st[0].type);
+}
+
+const struct te_tlvlist *
+tlv_set_add(struct linpool *pool, const struct te_tlvlist *list, const struct te_tlv *val)
+{
+  if (tlv_set_contains(list, val))
+    return list;
+
+  struct te_tlvlist *res = lp_alloc(pool, sizeof(struct te_tlvlist));
+
+  init_list(&res->tlv);
+
+  DBG("tlv_set_add: first type %d, second type %d\n", list?((const struct te_tlv *)HEAD(list->tlv))->st[0].type:-1, val->st[0].type);
+
+  if (list)
+  {
+    struct te_tlv *n;
+    WALK_LIST(n, list->tlv)
+    {
+      tlv_add_copy(pool, res, n);
+    }
+  }
+
+  tlv_add_copy(pool, res, val);
+  return res;
+}
+
+const struct te_tlvlist *
+tlv_set_union(struct linpool UNUSED *pool, const struct te_tlvlist *l1, const struct te_tlvlist *l2)
+{
+  if (!l1)
+    return l2;
+  if (!l2)
+    return l1;
+
+  /* FIXME */
+  void *res = NULL;
+  return res;
+}
+
+static int
+subtlv_same(const struct te_subtlv *st1, const struct te_subtlv *st2)
+{
+  if (st1 == NULL && st2 == NULL)
+    return 1;
+
+  if (st1 == NULL || st2 == NULL)
+    return 0;
+
+  if (st1->type != st2->type)
+    return 0;
+
+  switch(st1->type)
+  {
+  case TLV_ENCAPSULATION:
+    if (st1->u.tunnel_encap.type != st2->u.tunnel_encap.type ||
+	st1->u.tunnel_encap.length != st2->u.tunnel_encap.length ||
+	memcmp(st1->u.tunnel_encap.data, st2->u.tunnel_encap.data, st1->u.tunnel_encap.length))
+      return 0;
+    break;
+  case TLV_COLOR:
+    if (st1->u.color != st2->u.color)
+      return 0;
+    break;
+  case TLV_TUNNEL_ENDPOINT:
+    if (st1->u.tunnel_endpoint.reserved != st2->u.tunnel_endpoint.reserved ||
+	st1->u.tunnel_endpoint.af != st2->u.tunnel_endpoint.af ||
+	st1->u.tunnel_endpoint.af && ipa_compare(st1->u.tunnel_endpoint.ip, st2->u.tunnel_endpoint.ip))
+      return 0;
+    break;
+  case TLV_UDP_DEST_PORT:
+    if (st1->u.udp_dest_port != st2->u.udp_dest_port)
+      return 0;
+    break;
+  default:
+    if (st1->u.unknown.length != st2->u.unknown.length ||
+	memcmp(st1->u.unknown.data, st2->u.unknown.data, st1->u.unknown.length))
+      return 0;
+    break;
+  }
+
+  return 1;
+}
+
+static int
+tlv_same(const struct te_tlv *t1, const struct te_tlv *t2)
+{
+  if (t1 == NULL && t2 == NULL)
+    return 1;
+
+  if (t1 == NULL || t2 == NULL)
+    return 0;
+
+  if (t1->type != t2->type ||
+      t1->len != t2->len)
+    return 0;
+
+  for (uint i=0; i < t1->len; i++)
+    {
+      if (!subtlv_same(&t1->st[i], &t2->st[i]))
+	return 0;
+    }
+
+  return 1;
+}
+
+int
+tlvlist_same(const struct te_tlvlist *tl1, const struct te_tlvlist *tl2)
+{
+  if (tl1 == NULL && tl2 == NULL)
+    return 1;
+
+  if (tl1 == NULL || tl2 == NULL)
+    return 0;
+
+  const struct te_tlv *t1 = HEAD(tl1->tlv);
+  const struct te_tlv *t2 = HEAD(tl2->tlv);
+
+  while (NODE_VALID(t1) || NODE_VALID(t2))
+  {
+    if (!NODE_VALID(t1) || !NODE_VALID(t2))
+      return 0;
+
+    /* Both are valid. */
+    if (!tlv_same(t1, t2))
+      return 0;
+  }
+
+  return 1;
+}
+
+static int
+tlvlist_calc_tunnel_encap_new(const struct te_tlvlist *t, struct adata *ad)
+{
+  if (t == NULL)
+    return 0;
+
+  uint size = ad ? ad->length : 0;
+  byte *p = ad ? ad->data : NULL;
+
+  uint buf_size = te_init_encode_visitor(NULL, NULL, 0);
+  struct tlv_buffer *buf = alloca(buf_size);
+
+  if (te_init_encode_visitor(buf, p, size) < 0)
+    return -1;
+
+  if (walk_tlvlist(t, te_get_encode_visitor(), buf) < 0)
+    return -1;
+
+  return te_get_encode_length(buf);
+}
+
+struct adata *
+tlvlist_encode_tunnel_encap(struct linpool *pool, const struct te_tlvlist *tl)
+{
+  int len = tlvlist_calc_tunnel_encap_new(tl, NULL);
+
+  if (len < 0)
+    return NULL;
+
+  struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len);
+  ad->length = len;
+
+  if (tlvlist_calc_tunnel_encap_new(tl, ad) < 0)
+    return NULL;
+
+  return ad;
+}
+
+struct decoder_buf
+{
+  struct linpool *pool;
+  struct te_tlvlist *tl;
+  struct te_tlv *cur_tlv;
+  struct te_subtlv *cur_subtlv;
+  int cur_subtlv_index;
+};
+
+static int visitor_decode_tlv(int type, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  int count = te_count_subtlvs(ctx);
+
+  if (count < 0)
+    return -1;
+
+  buf->cur_tlv = lp_allocz(buf->pool, sizeof(struct te_tlv) + count * sizeof(struct te_subtlv));
+  buf->cur_tlv->type = type;
+  return 0;
+}
+
+static int visitor_decode_tlv_end(struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  add_tail(&buf->tl->tlv, &buf->cur_tlv->n);
+  buf->cur_tlv->len = buf->cur_subtlv_index;
+  buf->cur_tlv = NULL;
+  return 0;
+}
+
+static int
+visitor_decode_subtlv(int type, struct te_context *ctx){
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv = &buf->cur_tlv->st[buf->cur_subtlv_index];
+  buf->cur_subtlv->type = type;
+  return 0;
+}
+
+static int
+visitor_decode_subtlv_end(int UNUSED type, struct te_context *ctx){
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv_index++;
+  return 0;
+}
+
+static int
+visitor_decode_encap(const struct te_encap *encap, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv->u.tunnel_encap = *encap;
+  return 0;
+}
+
+static int
+visitor_decode_ep(const struct te_endpoint *ep, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv->u.tunnel_endpoint = *ep;
+  return 0;
+}
+
+static int
+visitor_decode_color(u32 color, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv->u.color = color;
+  return 0;
+}
+
+static int
+visitor_decode_udp_dest_port(u16 port, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv->u.udp_dest_port = port;
+  return 0;
+}
+
+static int
+visitor_decode_unknown(int UNUSED type, const struct te_unknown *unknown, struct te_context *ctx)
+{
+  struct decoder_buf *buf = ctx->opaque;
+
+  buf->cur_subtlv->u.unknown = *unknown;
+  return 0;
+}
+
+struct te_tlvlist *tlvlist_decode_tunnel_encap(struct linpool *pool,
+					       const struct adata *ad)
+{
+  struct te_tlvlist *tl = lp_alloc(pool, sizeof(struct te_tlvlist));
+  struct decoder_buf buf = { .pool = pool, .tl = tl, };
+  struct te_visitor visitor = {
+    .visit_tlv = visitor_decode_tlv,
+    .visit_tlv_end = visitor_decode_tlv_end,
+    .visit_subtlv = visitor_decode_subtlv,
+    .visit_subtlv_end = visitor_decode_subtlv_end,
+    .visit_encap = visitor_decode_encap,
+    .visit_ep = visitor_decode_ep,
+    .visit_color = visitor_decode_color,
+    .visit_udp_dest_port = visitor_decode_udp_dest_port,
+    .visit_unknown = visitor_decode_unknown,
+  };
+
+  init_list(&tl->tlv);
+
+  int res = walk_tunnel_encap(ad, &visitor, &buf);
+  if (res < 0)
+    return NULL;
+
+  return tl;
+}
diff --git a/nest/attrs.h b/nest/attrs.h
index 0475afa7..6f182e1a 100644
--- a/nest/attrs.h
+++ b/nest/attrs.h
@@ -30,6 +30,12 @@
 
 struct f_val;
 struct f_tree;
+struct te_subtlv;
+struct te_tlv;
+struct te_tlvlist;
+struct te_encap;
+struct te_endpoint;
+struct te_visitor;
 
 int as_path_valid(byte *data, uint len, int bs, int sets, int confed, char *err, uint elen);
 int as_path_16to32(byte *dst, const byte *src, uint len);
@@ -248,4 +254,65 @@ int rte_set_walk(const struct adata *list, u32 *pos, struct rte **val);
 
 void ec_set_sort_x(struct adata *set); /* Sort in place */
 
+
+/* a-tlv.c */
+
+
+/* Tunnel Encapsulation TLV types */
+#define TLV_TUNNEL_TYPE 0x00	/* Reserved. Used internally only. */
+#define TLV_ENCAPSULATION 0x01
+#define TLV_COLOR 0x04
+#define TLV_TUNNEL_ENDPOINT 0x06
+#define TLV_UDP_DEST_PORT 0x08
+
+struct te_encap {
+  int type;
+  uint length;
+  const void *data;
+};
+
+struct te_unknown {
+  uint length;
+  const void *data;
+};
+
+struct te_endpoint {
+  u32 reserved;
+  u16 af;
+  ip_addr ip;
+};
+
+/* Tunnel Encapsulation TLV */
+struct te_subtlv {
+  int type;
+  union {
+    struct te_encap tunnel_encap;
+    struct te_endpoint tunnel_endpoint;
+    u32 color;
+    u16 udp_dest_port;
+    struct te_unknown unknown;
+  } u;
+};
+
+struct te_tlv {
+  node n;
+  uint len;
+  int type;
+  struct te_subtlv st[0];
+};
+
+struct te_tlvlist {
+  list tlv;
+};
+
+const struct te_tlv *tlv_alloc(struct linpool *pool, const struct f_tree *set);
+int tlv_set_format(const struct te_tlvlist *set, int from, byte *buf, uint size);
+int tlv_set_contains(const struct te_tlvlist *list, const struct te_tlv *val);
+const struct te_tlvlist *tlv_set_add(struct linpool *pool, const struct te_tlvlist *list, const struct te_tlv *val);
+const struct te_tlvlist *tlv_set_union(struct linpool *pool, const struct te_tlvlist *l1, const struct te_tlvlist *l2);
+int tlvlist_same(const struct te_tlvlist *tl1, const struct te_tlvlist *tl2);
+
+struct adata *tlvlist_encode_tunnel_encap(struct linpool *pool, const struct te_tlvlist *tl);
+struct te_tlvlist *tlvlist_decode_tunnel_encap(struct linpool *pool, const struct adata *ad);
+
 #endif
diff --git a/nest/iface.h b/nest/iface.h
index f8e92850..daf84a7c 100644
--- a/nest/iface.h
+++ b/nest/iface.h
@@ -11,6 +11,7 @@
 
 #include "lib/lists.h"
 #include "lib/ip.h"
+#include "lib/net.h"
 
 extern list iface_list;
 
diff --git a/nest/route.h b/nest/route.h
index a17ae696..dc7a7abc 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -559,6 +559,7 @@ const char *ea_custom_name(uint ea);
 #define EAF_TYPE_LC_SET 0x12		/* Set of triplets of u32's - large community list */
 #define EAF_TYPE_IFACE 0x14		/* Interface pointer stored in adata */
 #define EAF_TYPE_STRING 0x16		/* Text string */
+#define EAF_TYPE_TUNNEL_ENCAP 0x1a	/* Tunnel Encapsulation (encoding per RFC 9012) */
 #define EAF_EMBEDDED 0x01		/* Data stored in eattr.u.data (part of type spec) */
 #define EAF_VAR_LENGTH 0x02		/* Attribute length is variable (part of type spec) */
 
diff --git a/proto/aggregator/aggregator.c b/proto/aggregator/aggregator.c
index e5c2a176..950da103 100644
--- a/proto/aggregator/aggregator.c
+++ b/proto/aggregator/aggregator.c
@@ -560,6 +560,8 @@ aggregator_rt_notify(struct proto *P, struct channel *src_ch, net *net, rte *new
 	case T_PATH_MASK_ITEM:
 	case T_ROUTE:
 	case T_ROUTES_BLOCK:
+	case T_SUBTLV:
+	case T_TLVLIST:
 	  bug("Invalid type %s in hashing", f_type_name(tmp_bucket->aggr_data[i].type));
 	case T_SET:
 	  MX(t);
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index 880cc3c4..f681ab8e 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -31,6 +31,7 @@
 #include "lib/timer.h"
 #include "lib/tlists.h"
 #include "lib/string.h"
+#include "lib/tunnel_encaps.h"
 #include "nest/route.h"
 #include "nest/protocol.h"
 #include "nest/iface.h"
@@ -1007,6 +1008,7 @@ main(int argc, char **argv)
   mpls_init();
 //  roa_init();
   config_init();
+  tunnel_encap_init();
 
   uid_t use_uid = get_uid(use_user);
   gid_t use_gid = get_gid(use_group);