IPSEC: restack SAs on backend change

Change-Id: I5852ca02d684fa9d59e1690efcaca06371c5faff
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/ipsec/ipsec.c b/src/vnet/ipsec/ipsec.c
index e88a72e..0ad11ba 100644
--- a/src/vnet/ipsec/ipsec.c
+++ b/src/vnet/ipsec/ipsec.c
@@ -181,6 +181,14 @@
   return b - im->esp_backends;
 }
 
+static walk_rc_t
+ipsec_sa_restack (ipsec_sa_t * sa, void *ctx)
+{
+  ipsec_sa_stack (sa);
+
+  return (WALK_CONTINUE);
+}
+
 int
 ipsec_select_ah_backend (ipsec_main_t * im, u32 backend_idx)
 {
@@ -199,6 +207,8 @@
   im->ah6_decrypt_node_index = b->ah6_decrypt_node_index;
   im->ah6_encrypt_next_index = b->ah6_encrypt_next_index;
   im->ah6_decrypt_next_index = b->ah6_decrypt_next_index;
+
+  ipsec_sa_walk (ipsec_sa_restack, NULL);
   return 0;
 }
 
@@ -220,6 +230,8 @@
   im->esp6_decrypt_node_index = b->esp6_decrypt_node_index;
   im->esp6_encrypt_next_index = b->esp6_encrypt_next_index;
   im->esp6_decrypt_next_index = b->esp6_decrypt_next_index;
+
+  ipsec_sa_walk (ipsec_sa_restack, NULL);
   return 0;
 }
 
diff --git a/src/vnet/ipsec/ipsec_sa.c b/src/vnet/ipsec/ipsec_sa.c
index f20d941..b0de76a 100644
--- a/src/vnet/ipsec/ipsec_sa.c
+++ b/src/vnet/ipsec/ipsec_sa.c
@@ -54,12 +54,12 @@
 /**
  * 'stack' (resolve the recursion for) the SA tunnel destination
  */
-static void
+void
 ipsec_sa_stack (ipsec_sa_t * sa)
 {
+  ipsec_main_t *im = &ipsec_main;
   fib_forward_chain_type_t fct;
   dpo_id_t tmp = DPO_INVALID;
-  vlib_node_t *node;
 
   fct = fib_forw_chain_type_from_fib_proto ((sa->is_tunnel_ip6 ?
 					     FIB_PROTOCOL_IP6 :
@@ -67,17 +67,15 @@
 
   fib_entry_contribute_forwarding (sa->fib_entry_index, fct, &tmp);
 
-  node = vlib_get_node_by_name (vlib_get_main (),
-				(sa->is_tunnel_ip6 ?
-				 (u8 *) "ah6-encrypt" :
-				 (u8 *) "ah4-encrypt"));
-  dpo_stack_from_node (node->index, &sa->dpo[IPSEC_PROTOCOL_AH], &tmp);
-
-  node = vlib_get_node_by_name (vlib_get_main (),
-				(sa->is_tunnel_ip6 ?
-				 (u8 *) "esp6-encrypt" :
-				 (u8 *) "esp4-encrypt"));
-  dpo_stack_from_node (node->index, &sa->dpo[IPSEC_PROTOCOL_ESP], &tmp);
+  dpo_stack_from_node ((sa->is_tunnel_ip6 ?
+			im->ah6_encrypt_node_index :
+			im->ah4_encrypt_node_index),
+		       &sa->dpo[IPSEC_PROTOCOL_AH], &tmp);
+  dpo_stack_from_node ((sa->is_tunnel_ip6 ?
+			im->esp6_encrypt_node_index :
+			im->esp4_encrypt_node_index),
+		       &sa->dpo[IPSEC_PROTOCOL_ESP], &tmp);
+  dpo_reset (&tmp);
 }
 
 int
@@ -291,6 +289,21 @@
   return p[0];
 }
 
+void
+ipsec_sa_walk (ipsec_sa_walk_cb_t cb, void *ctx)
+{
+  ipsec_main_t *im = &ipsec_main;
+  ipsec_sa_t *sa;
+
+  /* *INDENT-OFF* */
+  pool_foreach (sa, im->sad,
+  ({
+    if (WALK_CONTINUE != cb(sa, ctx))
+      break;
+  }));
+  /* *INDENT-ON* */
+}
+
 /**
  * Function definition to get a FIB node from its index
  */
diff --git a/src/vnet/ipsec/ipsec_sa.h b/src/vnet/ipsec/ipsec_sa.h
index 775343b..2e39566 100644
--- a/src/vnet/ipsec/ipsec_sa.h
+++ b/src/vnet/ipsec/ipsec_sa.h
@@ -151,12 +151,16 @@
 			 const ip46_address_t * tunnel_dst_addr,
 			 u32 * sa_index);
 extern u32 ipsec_sa_del (u32 id);
+extern void ipsec_sa_stack (ipsec_sa_t * sa);
 
 extern u8 ipsec_is_sa_used (u32 sa_index);
 extern int ipsec_set_sa_key (u32 id,
 			     const ipsec_key_t * ck, const ipsec_key_t * ik);
 extern u32 ipsec_get_sa_index_by_sa_id (u32 sa_id);
 
+typedef walk_rc_t (*ipsec_sa_walk_cb_t) (ipsec_sa_t * sa, void *ctx);
+extern void ipsec_sa_walk (ipsec_sa_walk_cb_t cd, void *ctx);
+
 extern u8 *format_ipsec_crypto_alg (u8 * s, va_list * args);
 extern u8 *format_ipsec_integ_alg (u8 * s, va_list * args);
 extern u8 *format_ipsec_sa (u8 * s, va_list * args);