TunnelEncaps: Generalize tunnel encapsulation

3 files changed, 15 insertions, 13 deletions

diff --git a/lib/tunnel_encaps.c b/lib/tunnel_encaps.c
index 43fcdbcb..c2b0f60d 100644
--- a/lib/tunnel_encaps.c
+++ b/lib/tunnel_encaps.c
@@ -1,14 +1,15 @@
 #include "lib/tunnel_encaps.h"
 
 static
-int decode_wireguard(const void *p, size_t sub_tlv_len, wg_key *pubkey, u16 *flags)
+int decode_encap(const void *p, size_t sub_tlv_len, void *encap, size_t *encap_size, u16 *flags)
 {
-  if (sub_tlv_len != sizeof(wg_key)) {
-    log(L_TRACE "WG: wireguard len error %d", sub_tlv_len);
+  if (sub_tlv_len > *encap_size) {
+    log(L_TRACE "WG: encapsulation len error %d > %d", sub_tlv_len, *encap_size);
     return -1;
   }
 
-  memcpy(pubkey, p, sizeof(wg_key));
+  memcpy(encap, p, sub_tlv_len);
+  *encap_size = sub_tlv_len;
   *flags |= FLAG_BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP;
   return 0;
 }
@@ -78,7 +79,7 @@ int decode_tunnel_ep(const void *p, size_t sub_tlv_len, u32 *as4, ip_addr *tunne
 }
 
 static
-int decode_sub_tlv(const u8 *p, size_t len, wg_key *pubkey,
+int decode_sub_tlv(const u8 *p, size_t len, void *encap, size_t *encap_size,
 		   u32 *tunnel_ep_as, ip_addr *tunnel_ep_addr,
 		   u32 *color, u16 *udp_dest_port, u16 *flags)
 {
@@ -114,7 +115,7 @@ int decode_sub_tlv(const u8 *p, size_t len, wg_key *pubkey,
 
   switch (type) {
   case BGP_TUNNEL_ENCAP_A_SUB_TLV_ENCAP:
-    res = decode_wireguard(p, sub_tlv_len, pubkey, flags);
+    res = decode_encap(p, sub_tlv_len, encap, encap_size, flags);
     break;
   case BGP_TUNNEL_ENCAP_A_SUB_TLV_TUNNEL_EP:
     res = decode_tunnel_ep(p, sub_tlv_len, tunnel_ep_as, tunnel_ep_addr, flags);
@@ -137,7 +138,7 @@ int decode_sub_tlv(const u8 *p, size_t len, wg_key *pubkey,
   return p - first + sub_tlv_len;
 }
 
-int decode_tunnel_encap(const eattr *e, u16 wg_tunnel_type, wg_key *pubkey, u32 *as4, ip_addr *tunnel_ep, u32 *color, u16 *udp_port, u16 *flags)
+int decode_tunnel_encap(const eattr *e, u16 wg_tunnel_type, void *encap, size_t *encap_size, u32 *as4, ip_addr *tunnel_ep, u32 *color, u16 *udp_port, u16 *flags)
 {
   const u8 *p = e->u.ptr->data;
   int len = e->u.ptr->length;
@@ -166,7 +167,7 @@ int decode_tunnel_encap(const eattr *e, u16 wg_tunnel_type, wg_key *pubkey, u32
   }
 
   for (const u8 *cur = p + 4; cur < p + 4 + value_length;) {
-    int res = decode_sub_tlv(cur, value_length, pubkey, as4, tunnel_ep, color, udp_port, flags);
+    int res = decode_sub_tlv(cur, value_length, encap, encap_size, as4, tunnel_ep, color, udp_port, flags);
 
     if (res < 0) {
       log(L_TRACE "WG: decode error %d", res);
diff --git a/lib/tunnel_encaps.h b/lib/tunnel_encaps.h
index 6c85a883..9d25e5c5 100644
--- a/lib/tunnel_encaps.h
+++ b/lib/tunnel_encaps.h
@@ -4,6 +4,8 @@
 #include "nest/route.h"
 #include "sysdep/linux/wireguard.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
@@ -14,6 +16,6 @@
 #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)
 
-int decode_tunnel_encap(const eattr *e, u16 wg_tunnel_type, wg_key *pubkey, u32 *as4, ip_addr *tunnel_ep, u32 *color, u16 *udp_port, u16 *flags);
+int decode_tunnel_encap(const eattr *e, u16 wg_tunnel_type, void *encap, size_t *encap_size, u32 *as4, ip_addr *tunnel_ep, u32 *color, u16 *udp_port, u16 *flags);
 
 #endif	/* _BIRD_TUNNEL_ENCAPS_ */
diff --git a/proto/wireguard/wireguard.c b/proto/wireguard/wireguard.c
index 212fc779..a355bf43 100644
--- a/proto/wireguard/wireguard.c
+++ b/proto/wireguard/wireguard.c
@@ -16,8 +16,6 @@
 #include "sysdep/unix/wg_user.h"
 #include "wireguard.h"
 
-#define BA_TUNNEL_ENCAP		0x17
-
 static
 int get_device(struct wg_proto *p, wg_device **pdev, const char *device_name)
 {
@@ -257,7 +255,8 @@ wg_rt_notify(struct proto *P, struct channel *CH, struct network *n,
         new->attrs->dest, n->n.addr);
 
       wg_key pubkey;
-      memset(pubkey, 0, sizeof(wg_key));
+      size_t pubkey_size = sizeof(wg_key);
+      memset(pubkey, 0, pubkey_size);
       u32 tunnel_ep_as4 = 0;
       ip_addr tunnel_ep_addr = IPA_NONE;
       u16 udp_dest_port = 0;
@@ -268,7 +267,7 @@ wg_rt_notify(struct proto *P, struct channel *CH, struct network *n,
       if (!t && he && he->src) {
 	t = ea_find(he->src->eattrs, EA_CODE(PROTOCOL_BGP, BA_TUNNEL_ENCAP));
       }
-      if (t && t->u.ptr && decode_tunnel_encap(t, c->tunnel_type, &pubkey, &tunnel_ep_as4, &tunnel_ep_addr, &color, &udp_dest_port, &flags) == 0) {
+      if (t && t->u.ptr && decode_tunnel_encap(t, c->tunnel_type, &pubkey, &pubkey_size, &tunnel_ep_as4, &tunnel_ep_addr, &color, &udp_dest_port, &flags) == 0 && pubkey_size == sizeof(wg_key)) {
 	log(L_TRACE "WG:     Attr %x %x %d %04x", t->flags, t->type, t->u.ptr->length, flags);
 
 	struct wg_device *dev = p->dev;