wireguard: add barrier to sync data

The current implmentation of the hash table is not thread-safe.
This design leads to a segfault when VPP is handling a lot of tunnels
for Wireguard, where one thread modifies the hash table and other
threads start the lookup at the same time.

This fix adds a barrier sync to the hash table access when Wireguard
adds or deletes an element.

Type: fix
Signed-off-by: Gabriel Oginski <gabrielx.oginski@intel.com>
Change-Id: Id460dfcd46ace17c7bdcd23bd9687d26cecf0a39

1 files changed, 17 insertions, 15 deletions

diff --git a/src/plugins/wireguard/wireguard_noise.c b/src/plugins/wireguard/wireguard_noise.c
index c9d8e31061a..19b0ce5a58c 100644
--- a/src/plugins/wireguard/wireguard_noise.c
+++ b/src/plugins/wireguard/wireguard_noise.c
@@ -33,8 +33,10 @@ noise_local_t *noise_local_pool;
 static noise_keypair_t *noise_remote_keypair_allocate (noise_remote_t *);
 static void noise_remote_keypair_free (vlib_main_t * vm, noise_remote_t *,
 				       noise_keypair_t **);
-static uint32_t noise_remote_handshake_index_get (noise_remote_t *);
-static void noise_remote_handshake_index_drop (noise_remote_t *);
+static uint32_t noise_remote_handshake_index_get (vlib_main_t *vm,
+						  noise_remote_t *);
+static void noise_remote_handshake_index_drop (vlib_main_t *vm,
+					       noise_remote_t *);
 
 static uint64_t noise_counter_send (noise_counter_t *);
 bool noise_counter_recv (noise_counter_t *, uint64_t);
@@ -86,7 +88,7 @@ noise_local_set_private (noise_local_t * l,
 }
 
 void
-noise_remote_init (noise_remote_t * r, uint32_t peer_pool_idx,
+noise_remote_init (vlib_main_t *vm, noise_remote_t *r, uint32_t peer_pool_idx,
 		   const uint8_t public[NOISE_PUBLIC_KEY_LEN],
 		   u32 noise_local_idx)
 {
@@ -97,18 +99,18 @@ noise_remote_init (noise_remote_t * r, uint32_t peer_pool_idx,
   r->r_local_idx = noise_local_idx;
   r->r_handshake.hs_state = HS_ZEROED;
 
-  noise_remote_precompute (r);
+  noise_remote_precompute (vm, r);
 }
 
 void
-noise_remote_precompute (noise_remote_t * r)
+noise_remote_precompute (vlib_main_t *vm, noise_remote_t *r)
 {
   noise_local_t *l = noise_local_get (r->r_local_idx);
 
   if (!curve25519_gen_shared (r->r_ss, l->l_private, r->r_public))
     clib_memset (r->r_ss, 0, NOISE_PUBLIC_KEY_LEN);
 
-  noise_remote_handshake_index_drop (r);
+  noise_remote_handshake_index_drop (vm, r);
   wg_secure_zero_memory (&r->r_handshake, sizeof (r->r_handshake));
 }
 
@@ -154,9 +156,9 @@ noise_create_initiation (vlib_main_t * vm, noise_remote_t * r,
   /* {t} */
   noise_tai64n_now (ets);
   noise_msg_encrypt (vm, ets, ets, NOISE_TIMESTAMP_LEN, key_idx, hs->hs_hash);
-  noise_remote_handshake_index_drop (r);
+  noise_remote_handshake_index_drop (vm, r);
   hs->hs_state = CREATED_INITIATION;
-  hs->hs_local_index = noise_remote_handshake_index_get (r);
+  hs->hs_local_index = noise_remote_handshake_index_get (vm, r);
   *s_idx = hs->hs_local_index;
   ret = true;
 error:
@@ -237,7 +239,7 @@ noise_consume_initiation (vlib_main_t * vm, noise_local_t * l,
     goto error;
 
   /* Ok, we're happy to accept this initiation now */
-  noise_remote_handshake_index_drop (r);
+  noise_remote_handshake_index_drop (vm, r);
   r->r_handshake = hs;
   *rp = r;
   ret = true;
@@ -291,7 +293,7 @@ noise_create_response (vlib_main_t * vm, noise_remote_t * r, uint32_t * s_idx,
 
 
   hs->hs_state = CREATED_RESPONSE;
-  hs->hs_local_index = noise_remote_handshake_index_get (r);
+  hs->hs_local_index = noise_remote_handshake_index_get (vm, r);
   *r_idx = hs->hs_remote_index;
   *s_idx = hs->hs_local_index;
   ret = true;
@@ -451,7 +453,7 @@ noise_remote_begin_session (vlib_main_t * vm, noise_remote_t * r)
 void
 noise_remote_clear (vlib_main_t * vm, noise_remote_t * r)
 {
-  noise_remote_handshake_index_drop (r);
+  noise_remote_handshake_index_drop (vm, r);
   wg_secure_zero_memory (&r->r_handshake, sizeof (r->r_handshake));
 
   clib_rwlock_writer_lock (&r->r_keypair_lock);
@@ -555,21 +557,21 @@ noise_remote_keypair_allocate (noise_remote_t * r)
 }
 
 static uint32_t
-noise_remote_handshake_index_get (noise_remote_t * r)
+noise_remote_handshake_index_get (vlib_main_t *vm, noise_remote_t *r)
 {
   noise_local_t *local = noise_local_get (r->r_local_idx);
   struct noise_upcall *u = &local->l_upcall;
-  return u->u_index_set (r);
+  return u->u_index_set (vm, r);
 }
 
 static void
-noise_remote_handshake_index_drop (noise_remote_t * r)
+noise_remote_handshake_index_drop (vlib_main_t *vm, noise_remote_t *r)
 {
   noise_handshake_t *hs = &r->r_handshake;
   noise_local_t *local = noise_local_get (r->r_local_idx);
   struct noise_upcall *u = &local->l_upcall;
   if (hs->hs_state != HS_ZEROED)
-    u->u_index_drop (hs->hs_local_index);
+    u->u_index_drop (vm, hs->hs_local_index);
 }
 
 static void