ikev2: do not accept rekey until old SA is deleted

Type: fix
Signed-off-by: Atzm Watanabe <atzmism@gmail.com>
Change-Id: I11b6107492004a45104857dc2dae01b9a5a01e3b

3 files changed, 75 insertions, 23 deletions

diff --git a/src/plugins/ikev2/ikev2.c b/src/plugins/ikev2/ikev2.c
index 20be89e1aaf..f8b9c6fb04b 100644
--- a/src/plugins/ikev2/ikev2.c
+++ b/src/plugins/ikev2/ikev2.c
@@ -1463,6 +1463,7 @@ ikev2_process_create_child_sa_req (vlib_main_t * vm,
       rekey = sa->rekey;
       if (vec_len (rekey) == 0)
 	goto cleanup_and_exit;
+      rekey->notify_type = 0;
       rekey->protocol_id = proposal->protocol_id;
       rekey->i_proposal =
 	ikev2_select_proposal (proposal, IKEV2_PROTOCOL_ESP);
@@ -1491,22 +1492,34 @@ ikev2_process_create_child_sa_req (vlib_main_t * vm,
 	      goto cleanup_and_exit;
 	    }
 	  vec_add2 (sa->rekey, rekey, 1);
+	  rekey->notify_type = 0;
 	  rekey->protocol_id = n->protocol_id;
 	  rekey->spi = n->spi;
-	  rekey->i_proposal = proposal;
-	  rekey->r_proposal =
-	    ikev2_select_proposal (proposal, IKEV2_PROTOCOL_ESP);
-	  /* update Ni */
-	  vec_reset_length (sa->i_nonce);
-	  vec_add (sa->i_nonce, nonce, nonce_len);
-	  /* generate new Nr */
-	  vec_validate (sa->r_nonce, nonce_len - 1);
-	  RAND_bytes ((u8 *) sa->r_nonce, nonce_len);
+	  if (sa->old_remote_id_present)
+	    {
+	      rekey->notify_type = IKEV2_NOTIFY_MSG_TEMPORARY_FAILURE;
+	      vec_free (proposal);
+	      vec_free (tsr);
+	      vec_free (tsi);
+	    }
+	  else
+	    {
+	      rekey->i_proposal = proposal;
+	      rekey->r_proposal =
+		ikev2_select_proposal (proposal, IKEV2_PROTOCOL_ESP);
+	      /* update Ni */
+	      vec_reset_length (sa->i_nonce);
+	      vec_add (sa->i_nonce, nonce, nonce_len);
+	      /* generate new Nr */
+	      vec_validate (sa->r_nonce, nonce_len - 1);
+	      RAND_bytes ((u8 *) sa->r_nonce, nonce_len);
+	    }
 	}
       else
 	{
 	  /* create new child SA */
 	  vec_add2 (sa->new_child, rekey, 1);
+	  rekey->notify_type = 0;
 	  rekey->i_proposal = proposal;
 	  rekey->r_proposal =
 	    ikev2_select_proposal (proposal, IKEV2_PROTOCOL_ESP);
@@ -2555,10 +2568,17 @@ ikev2_generate_message (vlib_buffer_t *b, ikev2_sa_t *sa, ike_header_t *ike,
 	}
       else if (vec_len (sa->rekey) > 0)
 	{
-	  ikev2_payload_add_sa (chain, sa->rekey[0].r_proposal);
-	  ikev2_payload_add_nonce (chain, sa->r_nonce);
-	  ikev2_payload_add_ts (chain, sa->rekey[0].tsi, IKEV2_PAYLOAD_TSI);
-	  ikev2_payload_add_ts (chain, sa->rekey[0].tsr, IKEV2_PAYLOAD_TSR);
+	  if (sa->rekey[0].notify_type)
+	    ikev2_payload_add_notify (chain, sa->rekey[0].notify_type, 0);
+	  else
+	    {
+	      ikev2_payload_add_sa (chain, sa->rekey[0].r_proposal);
+	      ikev2_payload_add_nonce (chain, sa->r_nonce);
+	      ikev2_payload_add_ts (chain, sa->rekey[0].tsi,
+				    IKEV2_PAYLOAD_TSI);
+	      ikev2_payload_add_ts (chain, sa->rekey[0].tsr,
+				    IKEV2_PAYLOAD_TSR);
+	    }
 	  vec_del1 (sa->rekey, 0);
 	}
       else if (vec_len (sa->new_child) > 0)
@@ -3320,7 +3340,8 @@ ikev2_node_internal (vlib_main_t *vm, vlib_node_runtime_t *node,
 
 	      if (sa0->rekey)
 		{
-		  if (sa0->rekey[0].protocol_id != IKEV2_PROTOCOL_IKE)
+		  if (!sa0->rekey[0].notify_type &&
+		      sa0->rekey[0].protocol_id != IKEV2_PROTOCOL_IKE)
 		    {
 		      if (sa0->childs)
 			ikev2_sa_free_all_child_sa (&sa0->childs);
diff --git a/src/plugins/ikev2/ikev2_priv.h b/src/plugins/ikev2/ikev2_priv.h
index 0a6036891b2..379b68dbdfc 100644
--- a/src/plugins/ikev2/ikev2_priv.h
+++ b/src/plugins/ikev2/ikev2_priv.h
@@ -312,6 +312,7 @@ typedef struct
 
 typedef struct
 {
+  u16 notify_type;
   u8 protocol_id;
   u32 spi;
   u32 ispi;
diff --git a/test/test_ikev2.py b/test/test_ikev2.py
index ac77a4163a1..3c588719581 100644
--- a/test/test_ikev2.py
+++ b/test/test_ikev2.py
@@ -752,14 +752,15 @@ class IkePeer(VppTestCase):
         else:
             self.assertNotIn(e.IPSEC_API_SAD_FLAG_UDP_ENCAP, ipsec_sa.flags)
 
-    def verify_ipsec_sas(self, is_rekey=False):
+    def verify_ipsec_sas(self, is_rekey=False, sa_count=None):
         sas = self.vapi.ipsec_sa_dump()
-        if is_rekey:
-            # after rekey there is a short period of time in which old
-            # inbound SA is still present
-            sa_count = 3
-        else:
-            sa_count = 2
+        if sa_count is None:
+            if is_rekey:
+                # after rekey there is a short period of time in which old
+                # inbound SA is still present
+                sa_count = 3
+            else:
+                sa_count = 2
         self.assertEqual(len(sas), sa_count)
         if self.sa.is_initiator:
             if is_rekey:
@@ -2078,12 +2079,15 @@ class TestResponderDpd(TestResponderPsk):
 class TestResponderRekey(TestResponderPsk):
     """test ikev2 responder - rekey"""
 
-    def rekey_from_initiator(self):
+    def send_rekey_from_initiator(self):
         packet = self.create_rekey_request()
         self.pg0.add_stream(packet)
         self.pg0.enable_capture()
         self.pg_start()
         capture = self.pg0.get_capture(1)
+        return capture
+
+    def process_rekey_response(self, capture):
         ih = self.get_ike_header(capture[0])
         plain = self.sa.hmac_and_decrypt(ih)
         sa = ikev2.IKEv2_payload_SA(plain)
@@ -2094,7 +2098,7 @@ class TestResponderRekey(TestResponderPsk):
 
     def test_responder(self):
         super(TestResponderRekey, self).test_responder()
-        self.rekey_from_initiator()
+        self.process_rekey_response(self.send_rekey_from_initiator())
         self.sa.calc_child_keys()
         self.verify_ike_sas()
         self.verify_ipsec_sas(is_rekey=True)
@@ -2103,6 +2107,32 @@ class TestResponderRekey(TestResponderPsk):
         self.assertEqual(r[0].sa.stats.n_rekey_req, 1)
 
 
+@tag_fixme_vpp_workers
+class TestResponderRekeyRepeat(TestResponderRekey):
+    """test ikev2 responder - rekey repeat"""
+
+    def test_responder(self):
+        super(TestResponderRekeyRepeat, self).test_responder()
+        # rekey request is not accepted until old IPsec SA is expired
+        capture = self.send_rekey_from_initiator()
+        ih = self.get_ike_header(capture[0])
+        plain = self.sa.hmac_and_decrypt(ih)
+        notify = ikev2.IKEv2_payload_Notify(plain)
+        self.assertEqual(notify.type, 43)
+        self.assertEqual(len(self.vapi.ipsec_sa_dump()), 3)
+        # rekey request is accepted after old IPsec SA was expired
+        for _ in range(50):
+            if len(self.vapi.ipsec_sa_dump()) != 3:
+                break
+            time.sleep(0.2)
+        else:
+            self.fail("old IPsec SA not expired")
+        self.process_rekey_response(self.send_rekey_from_initiator())
+        self.sa.calc_child_keys()
+        self.verify_ike_sas()
+        self.verify_ipsec_sas(sa_count=3)
+
+
 class TestResponderVrf(TestResponderPsk, Ikev2Params):
     """test ikev2 responder - non-default table id"""