src/vnet/ipsec/ipsec_sa.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2015 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
 #include <vnet/udp/udp.h>
 #include <vnet/fib/fib_table.h>
 #include <vnet/fib/fib_entry_track.h>
 #include <vnet/ipsec/ipsec_tun.h>

 /**
  * @brief
  * SA packet & bytes counters
  */
 vlib_combined_counter_main_t ipsec_sa_counters = {
   .name = "SA",
   .stat_segment_name = "/net/ipsec/sa",
 };


 static clib_error_t *
 ipsec_call_add_del_callbacks (ipsec_main_t * im, ipsec_sa_t * sa,
 			      u32 sa_index, int is_add)
 {
   ipsec_ah_backend_t *ab;
   ipsec_esp_backend_t *eb;
   switch (sa->protocol)
     {
     case IPSEC_PROTOCOL_AH:
       ab = pool_elt_at_index (im->ah_backends, im->ah_current_backend);
       if (ab->add_del_sa_sess_cb)
 	return ab->add_del_sa_sess_cb (sa_index, is_add);
       break;
     case IPSEC_PROTOCOL_ESP:
       eb = pool_elt_at_index (im->esp_backends, im->esp_current_backend);
       if (eb->add_del_sa_sess_cb)
 	return eb->add_del_sa_sess_cb (sa_index, is_add);
       break;
     }
   return 0;
 }

 void
 ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len)
 {
   memset (key, 0, sizeof (*key));

   if (len > sizeof (key->data))
     key->len = sizeof (key->data);
   else
     key->len = len;

   memcpy (key->data, data, key->len);
 }

 /**
  * 'stack' (resolve the recursion for) the SA tunnel destination
  */
 static 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;

   fct =
     fib_forw_chain_type_from_fib_proto ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
 					 FIB_PROTOCOL_IP6 :
 					 FIB_PROTOCOL_IP4));

   fib_entry_contribute_forwarding (sa->fib_entry_index, fct, &tmp);

   if (IPSEC_PROTOCOL_AH == sa->protocol)
     dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
 			  im->ah6_encrypt_node_index :
 			  im->ah4_encrypt_node_index), &sa->dpo, &tmp);
   else
     dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
 			  im->esp6_encrypt_node_index :
 			  im->esp4_encrypt_node_index), &sa->dpo, &tmp);
   dpo_reset (&tmp);
 }

 void
 ipsec_sa_set_crypto_alg (ipsec_sa_t * sa, ipsec_crypto_alg_t crypto_alg)
 {
   ipsec_main_t *im = &ipsec_main;
   sa->crypto_alg = crypto_alg;
   sa->crypto_iv_size = im->crypto_algs[crypto_alg].iv_size;
   sa->crypto_block_size = im->crypto_algs[crypto_alg].block_size;
   sa->sync_op_data.crypto_enc_op_id = im->crypto_algs[crypto_alg].enc_op_id;
   sa->sync_op_data.crypto_dec_op_id = im->crypto_algs[crypto_alg].dec_op_id;
   sa->crypto_calg = im->crypto_algs[crypto_alg].alg;
   ASSERT (sa->crypto_iv_size <= ESP_MAX_IV_SIZE);
   ASSERT (sa->crypto_block_size <= ESP_MAX_BLOCK_SIZE);
   if (IPSEC_CRYPTO_ALG_IS_GCM (crypto_alg))
     {
       sa->integ_icv_size = im->crypto_algs[crypto_alg].icv_size;
       ipsec_sa_set_IS_AEAD (sa);
     }
 }

 void
 ipsec_sa_set_integ_alg (ipsec_sa_t * sa, ipsec_integ_alg_t integ_alg)
 {
   ipsec_main_t *im = &ipsec_main;
   sa->integ_alg = integ_alg;
   sa->integ_icv_size = im->integ_algs[integ_alg].icv_size;
   sa->sync_op_data.integ_op_id = im->integ_algs[integ_alg].op_id;
   sa->integ_calg = im->integ_algs[integ_alg].alg;
   ASSERT (sa->integ_icv_size <= ESP_MAX_ICV_SIZE);
 }

 void
 ipsec_sa_set_async_op_ids (ipsec_sa_t * sa)
 {
   /* *INDENT-OFF* */
   if (ipsec_sa_is_set_USE_ESN (sa))
     {
 #define _(n, s, k) \
   if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
     sa->async_op_data.crypto_async_enc_op_id = \
       VNET_CRYPTO_OP_##n##_TAG16_AAD12_ENC; \
   if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
     sa->async_op_data.crypto_async_dec_op_id = \
       VNET_CRYPTO_OP_##n##_TAG16_AAD12_DEC;
     foreach_crypto_aead_alg
 #undef _
     }
   else
     {
 #define _(n, s, k) \
   if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
     sa->async_op_data.crypto_async_enc_op_id = \
       VNET_CRYPTO_OP_##n##_TAG16_AAD8_ENC; \
   if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
     sa->async_op_data.crypto_async_dec_op_id = \
       VNET_CRYPTO_OP_##n##_TAG16_AAD8_DEC;
     foreach_crypto_aead_alg
 #undef _
     }

 #define _(c, h, s, k ,d) \
   if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##c##_ENC && \
       sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
     sa->async_op_data.crypto_async_enc_op_id = \
       VNET_CRYPTO_OP_##c##_##h##_TAG##d##_ENC; \
   if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##c##_DEC && \
       sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
     sa->async_op_data.crypto_async_dec_op_id = \
       VNET_CRYPTO_OP_##c##_##h##_TAG##d##_DEC;
   foreach_crypto_link_async_alg
 #undef _
   /* *INDENT-ON* */
 }

 int
 ipsec_sa_add_and_lock (u32 id,
 		       u32 spi,
 		       ipsec_protocol_t proto,
 		       ipsec_crypto_alg_t crypto_alg,
 		       const ipsec_key_t * ck,
 		       ipsec_integ_alg_t integ_alg,
 		       const ipsec_key_t * ik,
 		       ipsec_sa_flags_t flags,
 		       u32 tx_table_id,
 		       u32 salt,
 		       const ip46_address_t * tun_src,
 		       const ip46_address_t * tun_dst, u32 * sa_out_index,
 		       u16 dst_port)
 {
   vlib_main_t *vm = vlib_get_main ();
   ipsec_main_t *im = &ipsec_main;
   clib_error_t *err;
   ipsec_sa_t *sa;
   u32 sa_index;
   uword *p;

   p = hash_get (im->sa_index_by_sa_id, id);
   if (p)
     return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;

   pool_get_aligned_zero (im->sad, sa, CLIB_CACHE_LINE_BYTES);

   fib_node_init (&sa->node, FIB_NODE_TYPE_IPSEC_SA);
   fib_node_lock (&sa->node);
   sa_index = sa - im->sad;

   vlib_validate_combined_counter (&ipsec_sa_counters, sa_index);
   vlib_zero_combined_counter (&ipsec_sa_counters, sa_index);

   sa->id = id;
   sa->spi = spi;
   sa->stat_index = sa_index;
   sa->protocol = proto;
   sa->flags = flags;
   sa->salt = salt;
   sa->encrypt_thread_index = (vlib_num_workers ())? ~0 : 0;
   sa->decrypt_thread_index = (vlib_num_workers ())? ~0 : 0;
   if (integ_alg != IPSEC_INTEG_ALG_NONE)
     {
       ipsec_sa_set_integ_alg (sa, integ_alg);
       clib_memcpy (&sa->integ_key, ik, sizeof (sa->integ_key));
     }
   ipsec_sa_set_crypto_alg (sa, crypto_alg);
   ipsec_sa_set_async_op_ids (sa);

   clib_memcpy (&sa->crypto_key, ck, sizeof (sa->crypto_key));
   ip46_address_copy (&sa->tunnel_src_addr, tun_src);
   ip46_address_copy (&sa->tunnel_dst_addr, tun_dst);

   sa->crypto_key_index = vnet_crypto_key_add (vm,
 					      im->crypto_algs[crypto_alg].alg,
 					      (u8 *) ck->data, ck->len);
   if (~0 == sa->crypto_key_index)
     {
       pool_put (im->sad, sa);
       return VNET_API_ERROR_KEY_LENGTH;
     }

   if (integ_alg != IPSEC_INTEG_ALG_NONE)
     {
       sa->integ_key_index = vnet_crypto_key_add (vm,
 						 im->
 						 integ_algs[integ_alg].alg,
 						 (u8 *) ik->data, ik->len);
       if (~0 == sa->integ_key_index)
 	{
 	  pool_put (im->sad, sa);
 	  return VNET_API_ERROR_KEY_LENGTH;
 	}
     }

   if (sa->async_op_data.crypto_async_enc_op_id &&
       !ipsec_sa_is_set_IS_AEAD (sa))
     {				//AES-CBC & HMAC
       sa->async_op_data.linked_key_index =
 	vnet_crypto_key_add_linked (vm, sa->crypto_key_index,
 				    sa->integ_key_index);
     }

   if (im->async_mode)
     sa->crypto_op_data = sa->async_op_data.data;
   else
     sa->crypto_op_data = sa->sync_op_data.data;

   err = ipsec_check_support_cb (im, sa);
   if (err)
     {
       clib_warning ("%s", err->what);
       pool_put (im->sad, sa);
       return VNET_API_ERROR_UNIMPLEMENTED;
     }

   err = ipsec_call_add_del_callbacks (im, sa, sa_index, 1);
   if (err)
     {
       pool_put (im->sad, sa);
       return VNET_API_ERROR_SYSCALL_ERROR_1;
     }

   if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
     {
       fib_protocol_t fproto = (ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
 			       FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4);
       fib_prefix_t pfx = {
 	.fp_addr = sa->tunnel_dst_addr,
 	.fp_len = (ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ? 128 : 32),
 	.fp_proto = fproto,
       };
       sa->tx_fib_index = fib_table_find (fproto, tx_table_id);
       if (sa->tx_fib_index == ~((u32) 0))
 	{
 	  pool_put (im->sad, sa);
 	  return VNET_API_ERROR_NO_SUCH_FIB;
 	}

       sa->fib_entry_index = fib_entry_track (sa->tx_fib_index,
 					     &pfx,
 					     FIB_NODE_TYPE_IPSEC_SA,
 					     sa_index, &sa->sibling);
       ipsec_sa_stack (sa);

       /* generate header templates */
       if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa))
 	{
 	  sa->ip6_hdr.ip_version_traffic_class_and_flow_label = 0x60;
 	  sa->ip6_hdr.hop_limit = 254;
 	  sa->ip6_hdr.src_address.as_u64[0] =
 	    sa->tunnel_src_addr.ip6.as_u64[0];
 	  sa->ip6_hdr.src_address.as_u64[1] =
 	    sa->tunnel_src_addr.ip6.as_u64[1];
 	  sa->ip6_hdr.dst_address.as_u64[0] =
 	    sa->tunnel_dst_addr.ip6.as_u64[0];
 	  sa->ip6_hdr.dst_address.as_u64[1] =
 	    sa->tunnel_dst_addr.ip6.as_u64[1];
 	  if (ipsec_sa_is_set_UDP_ENCAP (sa))
 	    sa->ip6_hdr.protocol = IP_PROTOCOL_UDP;
 	  else
 	    sa->ip6_hdr.protocol = IP_PROTOCOL_IPSEC_ESP;
 	}
       else
 	{
 	  sa->ip4_hdr.ip_version_and_header_length = 0x45;
 	  sa->ip4_hdr.ttl = 254;
 	  sa->ip4_hdr.src_address.as_u32 = sa->tunnel_src_addr.ip4.as_u32;
 	  sa->ip4_hdr.dst_address.as_u32 = sa->tunnel_dst_addr.ip4.as_u32;

 	  if (ipsec_sa_is_set_UDP_ENCAP (sa))
 	    sa->ip4_hdr.protocol = IP_PROTOCOL_UDP;
 	  else
 	    sa->ip4_hdr.protocol = IP_PROTOCOL_IPSEC_ESP;
 	  sa->ip4_hdr.checksum = ip4_header_checksum (&sa->ip4_hdr);
 	}
     }

   if (ipsec_sa_is_set_UDP_ENCAP (sa))
     {
       if (dst_port == IPSEC_UDP_PORT_NONE)
 	{
 	  sa->udp_hdr.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 	  sa->udp_hdr.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 	}
       else
 	{
 	  sa->udp_hdr.src_port = clib_host_to_net_u16 (dst_port);
 	  sa->udp_hdr.dst_port = clib_host_to_net_u16 (dst_port);
 	}
     }

   hash_set (im->sa_index_by_sa_id, sa->id, sa_index);

   if (sa_out_index)
     *sa_out_index = sa_index;

   return (0);
 }

 static void
 ipsec_sa_del (ipsec_sa_t * sa)
 {
   vlib_main_t *vm = vlib_get_main ();
   ipsec_main_t *im = &ipsec_main;
   u32 sa_index;

   sa_index = sa - im->sad;
   hash_unset (im->sa_index_by_sa_id, sa->id);

   /* no recovery possible when deleting an SA */
   (void) ipsec_call_add_del_callbacks (im, sa, sa_index, 0);

   if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
     {
       fib_entry_untrack (sa->fib_entry_index, sa->sibling);
       dpo_reset (&sa->dpo);
     }
   vnet_crypto_key_del (vm, sa->crypto_key_index);
   if (sa->integ_alg != IPSEC_INTEG_ALG_NONE)
     vnet_crypto_key_del (vm, sa->integ_key_index);
   pool_put (im->sad, sa);
 }

 void
 ipsec_sa_unlock (index_t sai)
 {
   ipsec_main_t *im = &ipsec_main;
   ipsec_sa_t *sa;

   if (INDEX_INVALID == sai)
     return;

   sa = pool_elt_at_index (im->sad, sai);

   fib_node_unlock (&sa->node);
 }

 void
 ipsec_sa_lock (index_t sai)
 {
   ipsec_main_t *im = &ipsec_main;
   ipsec_sa_t *sa;

   if (INDEX_INVALID == sai)
     return;

   sa = pool_elt_at_index (im->sad, sai);

   fib_node_lock (&sa->node);
 }

 index_t
 ipsec_sa_find_and_lock (u32 id)
 {
   ipsec_main_t *im = &ipsec_main;
   ipsec_sa_t *sa;
   uword *p;

   p = hash_get (im->sa_index_by_sa_id, id);

   if (!p)
     return INDEX_INVALID;

   sa = pool_elt_at_index (im->sad, p[0]);

   fib_node_lock (&sa->node);

   return (p[0]);
 }

 int
 ipsec_sa_unlock_id (u32 id)
 {
   ipsec_main_t *im = &ipsec_main;
   uword *p;

   p = hash_get (im->sa_index_by_sa_id, id);

   if (!p)
     return VNET_API_ERROR_NO_SUCH_ENTRY;

   ipsec_sa_unlock (p[0]);

   return (0);
 }

 void
 ipsec_sa_clear (index_t sai)
 {
   vlib_zero_combined_counter (&ipsec_sa_counters, sai);
 }

 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
  */
 static fib_node_t *
 ipsec_sa_fib_node_get (fib_node_index_t index)
 {
   ipsec_main_t *im;
   ipsec_sa_t *sa;

   im = &ipsec_main;
   sa = pool_elt_at_index (im->sad, index);

   return (&sa->node);
 }

 static ipsec_sa_t *
 ipsec_sa_from_fib_node (fib_node_t * node)
 {
   ASSERT (FIB_NODE_TYPE_IPSEC_SA == node->fn_type);
   return ((ipsec_sa_t *) (((char *) node) -
 			  STRUCT_OFFSET_OF (ipsec_sa_t, node)));

 }

 /**
  * Function definition to inform the FIB node that its last lock has gone.
  */
 static void
 ipsec_sa_last_lock_gone (fib_node_t * node)
 {
   /*
    * The ipsec SA is a root of the graph. As such
    * it never has children and thus is never locked.
    */
   ipsec_sa_del (ipsec_sa_from_fib_node (node));
 }

 /**
  * Function definition to backwalk a FIB node
  */
 static fib_node_back_walk_rc_t
 ipsec_sa_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
 {
   ipsec_sa_stack (ipsec_sa_from_fib_node (node));

   return (FIB_NODE_BACK_WALK_CONTINUE);
 }

 /*
  * Virtual function table registered by SAs
  * for participation in the FIB object graph.
  */
 const static fib_node_vft_t ipsec_sa_vft = {
   .fnv_get = ipsec_sa_fib_node_get,
   .fnv_last_lock = ipsec_sa_last_lock_gone,
   .fnv_back_walk = ipsec_sa_back_walk,
 };

 /* force inclusion from application's main.c */
 clib_error_t *
 ipsec_sa_interface_init (vlib_main_t * vm)
 {
   fib_node_register_type (FIB_NODE_TYPE_IPSEC_SA, &ipsec_sa_vft);

   return 0;
 }

 VLIB_INIT_FUNCTION (ipsec_sa_interface_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2015 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <vnet/ipsec/ipsec.h>
	#include <vnet/ipsec/esp.h>
	#include <vnet/udp/udp.h>
	#include <vnet/fib/fib_table.h>
	#include <vnet/fib/fib_entry_track.h>
	#include <vnet/ipsec/ipsec_tun.h>

	/**
	* @brief
	* SA packet & bytes counters
	*/
	vlib_combined_counter_main_t ipsec_sa_counters = {
	.name = "SA",
	.stat_segment_name = "/net/ipsec/sa",
	};


	static clib_error_t *
	ipsec_call_add_del_callbacks (ipsec_main_t * im, ipsec_sa_t * sa,
	u32 sa_index, int is_add)
	{
	ipsec_ah_backend_t *ab;
	ipsec_esp_backend_t *eb;
	switch (sa->protocol)
	{
	case IPSEC_PROTOCOL_AH:
	ab = pool_elt_at_index (im->ah_backends, im->ah_current_backend);
	if (ab->add_del_sa_sess_cb)
	return ab->add_del_sa_sess_cb (sa_index, is_add);
	break;
	case IPSEC_PROTOCOL_ESP:
	eb = pool_elt_at_index (im->esp_backends, im->esp_current_backend);
	if (eb->add_del_sa_sess_cb)
	return eb->add_del_sa_sess_cb (sa_index, is_add);
	break;
	}
	return 0;
	}

	void
	ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len)
	{
	memset (key, 0, sizeof (*key));

	if (len > sizeof (key->data))
	key->len = sizeof (key->data);
	else
	key->len = len;

	memcpy (key->data, data, key->len);
	}

	/**
	* 'stack' (resolve the recursion for) the SA tunnel destination
	*/
	static 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;

	fct =
	fib_forw_chain_type_from_fib_proto ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
	FIB_PROTOCOL_IP6 :
	FIB_PROTOCOL_IP4));

	fib_entry_contribute_forwarding (sa->fib_entry_index, fct, &tmp);

	if (IPSEC_PROTOCOL_AH == sa->protocol)
	dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
	im->ah6_encrypt_node_index :
	im->ah4_encrypt_node_index), &sa->dpo, &tmp);
	else
	dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
	im->esp6_encrypt_node_index :
	im->esp4_encrypt_node_index), &sa->dpo, &tmp);
	dpo_reset (&tmp);
	}

	void
	ipsec_sa_set_crypto_alg (ipsec_sa_t * sa, ipsec_crypto_alg_t crypto_alg)
	{
	ipsec_main_t *im = &ipsec_main;
	sa->crypto_alg = crypto_alg;
	sa->crypto_iv_size = im->crypto_algs[crypto_alg].iv_size;
	sa->crypto_block_size = im->crypto_algs[crypto_alg].block_size;
	sa->sync_op_data.crypto_enc_op_id = im->crypto_algs[crypto_alg].enc_op_id;
	sa->sync_op_data.crypto_dec_op_id = im->crypto_algs[crypto_alg].dec_op_id;
	sa->crypto_calg = im->crypto_algs[crypto_alg].alg;
	ASSERT (sa->crypto_iv_size <= ESP_MAX_IV_SIZE);
	ASSERT (sa->crypto_block_size <= ESP_MAX_BLOCK_SIZE);
	if (IPSEC_CRYPTO_ALG_IS_GCM (crypto_alg))
	{
	sa->integ_icv_size = im->crypto_algs[crypto_alg].icv_size;
	ipsec_sa_set_IS_AEAD (sa);
	}
	}

	void
	ipsec_sa_set_integ_alg (ipsec_sa_t * sa, ipsec_integ_alg_t integ_alg)
	{
	ipsec_main_t *im = &ipsec_main;
	sa->integ_alg = integ_alg;
	sa->integ_icv_size = im->integ_algs[integ_alg].icv_size;
	sa->sync_op_data.integ_op_id = im->integ_algs[integ_alg].op_id;
	sa->integ_calg = im->integ_algs[integ_alg].alg;
	ASSERT (sa->integ_icv_size <= ESP_MAX_ICV_SIZE);
	}

	void
	ipsec_sa_set_async_op_ids (ipsec_sa_t * sa)
	{
	/* INDENT-OFF */
	if (ipsec_sa_is_set_USE_ESN (sa))
	{
	#define _(n, s, k) \
	if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
	sa->async_op_data.crypto_async_enc_op_id = \
	VNET_CRYPTO_OP_##n##_TAG16_AAD12_ENC; \
	if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
	sa->async_op_data.crypto_async_dec_op_id = \
	VNET_CRYPTO_OP_##n##_TAG16_AAD12_DEC;
	foreach_crypto_aead_alg
	#undef _
	}
	else
	{
	#define _(n, s, k) \
	if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
	sa->async_op_data.crypto_async_enc_op_id = \
	VNET_CRYPTO_OP_##n##_TAG16_AAD8_ENC; \
	if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
	sa->async_op_data.crypto_async_dec_op_id = \
	VNET_CRYPTO_OP_##n##_TAG16_AAD8_DEC;
	foreach_crypto_aead_alg
	#undef _
	}

	#define _(c, h, s, k ,d) \
	if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##c##_ENC && \
	sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
	sa->async_op_data.crypto_async_enc_op_id = \
	VNET_CRYPTO_OP_##c##_##h##_TAG##d##_ENC; \
	if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##c##_DEC && \
	sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
	sa->async_op_data.crypto_async_dec_op_id = \
	VNET_CRYPTO_OP_##c##_##h##_TAG##d##_DEC;
	foreach_crypto_link_async_alg
	#undef _
	/* INDENT-ON */
	}

	int
	ipsec_sa_add_and_lock (u32 id,
	u32 spi,
	ipsec_protocol_t proto,
	ipsec_crypto_alg_t crypto_alg,
	const ipsec_key_t * ck,
	ipsec_integ_alg_t integ_alg,
	const ipsec_key_t * ik,
	ipsec_sa_flags_t flags,
	u32 tx_table_id,
	u32 salt,
	const ip46_address_t * tun_src,
	const ip46_address_t * tun_dst, u32 * sa_out_index,
	u16 dst_port)
	{
	vlib_main_t *vm = vlib_get_main ();
	ipsec_main_t *im = &ipsec_main;
	clib_error_t *err;
	ipsec_sa_t *sa;
	u32 sa_index;
	uword *p;

	p = hash_get (im->sa_index_by_sa_id, id);
	if (p)
	return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;

	pool_get_aligned_zero (im->sad, sa, CLIB_CACHE_LINE_BYTES);

	fib_node_init (&sa->node, FIB_NODE_TYPE_IPSEC_SA);
	fib_node_lock (&sa->node);
	sa_index = sa - im->sad;

	vlib_validate_combined_counter (&ipsec_sa_counters, sa_index);
	vlib_zero_combined_counter (&ipsec_sa_counters, sa_index);

	sa->id = id;
	sa->spi = spi;
	sa->stat_index = sa_index;
	sa->protocol = proto;
	sa->flags = flags;
	sa->salt = salt;
	sa->encrypt_thread_index = (vlib_num_workers ())? ~0 : 0;
	sa->decrypt_thread_index = (vlib_num_workers ())? ~0 : 0;
	if (integ_alg != IPSEC_INTEG_ALG_NONE)
	{
	ipsec_sa_set_integ_alg (sa, integ_alg);
	clib_memcpy (&sa->integ_key, ik, sizeof (sa->integ_key));
	}
	ipsec_sa_set_crypto_alg (sa, crypto_alg);
	ipsec_sa_set_async_op_ids (sa);

	clib_memcpy (&sa->crypto_key, ck, sizeof (sa->crypto_key));
	ip46_address_copy (&sa->tunnel_src_addr, tun_src);
	ip46_address_copy (&sa->tunnel_dst_addr, tun_dst);

	sa->crypto_key_index = vnet_crypto_key_add (vm,
	im->crypto_algs[crypto_alg].alg,
	(u8 *) ck->data, ck->len);
	if (~0 == sa->crypto_key_index)
	{
	pool_put (im->sad, sa);
	return VNET_API_ERROR_KEY_LENGTH;
	}

	if (integ_alg != IPSEC_INTEG_ALG_NONE)
	{
	sa->integ_key_index = vnet_crypto_key_add (vm,
	im->
	integ_algs[integ_alg].alg,
	(u8 *) ik->data, ik->len);
	if (~0 == sa->integ_key_index)
	{
	pool_put (im->sad, sa);
	return VNET_API_ERROR_KEY_LENGTH;
	}
	}

	if (sa->async_op_data.crypto_async_enc_op_id &&
	!ipsec_sa_is_set_IS_AEAD (sa))
	{ //AES-CBC & HMAC
	sa->async_op_data.linked_key_index =
	vnet_crypto_key_add_linked (vm, sa->crypto_key_index,
	sa->integ_key_index);
	}

	if (im->async_mode)
	sa->crypto_op_data = sa->async_op_data.data;
	else
	sa->crypto_op_data = sa->sync_op_data.data;

	err = ipsec_check_support_cb (im, sa);
	if (err)
	{
	clib_warning ("%s", err->what);
	pool_put (im->sad, sa);
	return VNET_API_ERROR_UNIMPLEMENTED;
	}

	err = ipsec_call_add_del_callbacks (im, sa, sa_index, 1);
	if (err)
	{
	pool_put (im->sad, sa);
	return VNET_API_ERROR_SYSCALL_ERROR_1;
	}

	if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
	{
	fib_protocol_t fproto = (ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
	FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4);
	fib_prefix_t pfx = {
	.fp_addr = sa->tunnel_dst_addr,
	.fp_len = (ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ? 128 : 32),
	.fp_proto = fproto,
	};
	sa->tx_fib_index = fib_table_find (fproto, tx_table_id);
	if (sa->tx_fib_index == ~((u32) 0))
	{
	pool_put (im->sad, sa);
	return VNET_API_ERROR_NO_SUCH_FIB;
	}

	sa->fib_entry_index = fib_entry_track (sa->tx_fib_index,
	&pfx,
	FIB_NODE_TYPE_IPSEC_SA,
	sa_index, &sa->sibling);
	ipsec_sa_stack (sa);

	/* generate header templates */
	if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa))
	{
	sa->ip6_hdr.ip_version_traffic_class_and_flow_label = 0x60;
	sa->ip6_hdr.hop_limit = 254;
	sa->ip6_hdr.src_address.as_u64[0] =
	sa->tunnel_src_addr.ip6.as_u64[0];
	sa->ip6_hdr.src_address.as_u64[1] =
	sa->tunnel_src_addr.ip6.as_u64[1];
	sa->ip6_hdr.dst_address.as_u64[0] =
	sa->tunnel_dst_addr.ip6.as_u64[0];
	sa->ip6_hdr.dst_address.as_u64[1] =
	sa->tunnel_dst_addr.ip6.as_u64[1];
	if (ipsec_sa_is_set_UDP_ENCAP (sa))
	sa->ip6_hdr.protocol = IP_PROTOCOL_UDP;
	else
	sa->ip6_hdr.protocol = IP_PROTOCOL_IPSEC_ESP;
	}
	else
	{
	sa->ip4_hdr.ip_version_and_header_length = 0x45;
	sa->ip4_hdr.ttl = 254;
	sa->ip4_hdr.src_address.as_u32 = sa->tunnel_src_addr.ip4.as_u32;
	sa->ip4_hdr.dst_address.as_u32 = sa->tunnel_dst_addr.ip4.as_u32;

	if (ipsec_sa_is_set_UDP_ENCAP (sa))
	sa->ip4_hdr.protocol = IP_PROTOCOL_UDP;
	else
	sa->ip4_hdr.protocol = IP_PROTOCOL_IPSEC_ESP;
	sa->ip4_hdr.checksum = ip4_header_checksum (&sa->ip4_hdr);
	}
	}

	if (ipsec_sa_is_set_UDP_ENCAP (sa))
	{
	if (dst_port == IPSEC_UDP_PORT_NONE)
	{
	sa->udp_hdr.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
	sa->udp_hdr.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
	}
	else
	{
	sa->udp_hdr.src_port = clib_host_to_net_u16 (dst_port);
	sa->udp_hdr.dst_port = clib_host_to_net_u16 (dst_port);
	}
	}

	hash_set (im->sa_index_by_sa_id, sa->id, sa_index);

	if (sa_out_index)
	*sa_out_index = sa_index;

	return (0);
	}

	static void
	ipsec_sa_del (ipsec_sa_t * sa)
	{
	vlib_main_t *vm = vlib_get_main ();
	ipsec_main_t *im = &ipsec_main;
	u32 sa_index;

	sa_index = sa - im->sad;
	hash_unset (im->sa_index_by_sa_id, sa->id);

	/* no recovery possible when deleting an SA */
	(void) ipsec_call_add_del_callbacks (im, sa, sa_index, 0);

	if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
	{
	fib_entry_untrack (sa->fib_entry_index, sa->sibling);
	dpo_reset (&sa->dpo);
	}
	vnet_crypto_key_del (vm, sa->crypto_key_index);
	if (sa->integ_alg != IPSEC_INTEG_ALG_NONE)
	vnet_crypto_key_del (vm, sa->integ_key_index);
	pool_put (im->sad, sa);
	}

	void
	ipsec_sa_unlock (index_t sai)
	{
	ipsec_main_t *im = &ipsec_main;
	ipsec_sa_t *sa;

	if (INDEX_INVALID == sai)
	return;

	sa = pool_elt_at_index (im->sad, sai);

	fib_node_unlock (&sa->node);
	}

	void
	ipsec_sa_lock (index_t sai)
	{
	ipsec_main_t *im = &ipsec_main;
	ipsec_sa_t *sa;

	if (INDEX_INVALID == sai)
	return;

	sa = pool_elt_at_index (im->sad, sai);

	fib_node_lock (&sa->node);
	}

	index_t
	ipsec_sa_find_and_lock (u32 id)
	{
	ipsec_main_t *im = &ipsec_main;
	ipsec_sa_t *sa;
	uword *p;

	p = hash_get (im->sa_index_by_sa_id, id);

	if (!p)
	return INDEX_INVALID;

	sa = pool_elt_at_index (im->sad, p[0]);

	fib_node_lock (&sa->node);

	return (p[0]);
	}

	int
	ipsec_sa_unlock_id (u32 id)
	{
	ipsec_main_t *im = &ipsec_main;
	uword *p;

	p = hash_get (im->sa_index_by_sa_id, id);

	if (!p)
	return VNET_API_ERROR_NO_SUCH_ENTRY;

	ipsec_sa_unlock (p[0]);

	return (0);
	}

	void
	ipsec_sa_clear (index_t sai)
	{
	vlib_zero_combined_counter (&ipsec_sa_counters, sai);
	}

	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
	*/
	static fib_node_t *
	ipsec_sa_fib_node_get (fib_node_index_t index)
	{
	ipsec_main_t *im;
	ipsec_sa_t *sa;

	im = &ipsec_main;
	sa = pool_elt_at_index (im->sad, index);

	return (&sa->node);
	}

	static ipsec_sa_t *
	ipsec_sa_from_fib_node (fib_node_t * node)
	{
	ASSERT (FIB_NODE_TYPE_IPSEC_SA == node->fn_type);
	return ((ipsec_sa_t ) (((char ) node) -
	STRUCT_OFFSET_OF (ipsec_sa_t, node)));

	}

	/**
	* Function definition to inform the FIB node that its last lock has gone.
	*/
	static void
	ipsec_sa_last_lock_gone (fib_node_t * node)
	{
	/*
	* The ipsec SA is a root of the graph. As such
	* it never has children and thus is never locked.
	*/
	ipsec_sa_del (ipsec_sa_from_fib_node (node));
	}

	/**
	* Function definition to backwalk a FIB node
	*/
	static fib_node_back_walk_rc_t
	ipsec_sa_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
	{
	ipsec_sa_stack (ipsec_sa_from_fib_node (node));

	return (FIB_NODE_BACK_WALK_CONTINUE);
	}

	/*
	* Virtual function table registered by SAs
	* for participation in the FIB object graph.
	*/
	const static fib_node_vft_t ipsec_sa_vft = {
	.fnv_get = ipsec_sa_fib_node_get,
	.fnv_last_lock = ipsec_sa_last_lock_gone,
	.fnv_back_walk = ipsec_sa_back_walk,
	};

	/* force inclusion from application's main.c */
	clib_error_t *
	ipsec_sa_interface_init (vlib_main_t * vm)
	{
	fib_node_register_type (FIB_NODE_TYPE_IPSEC_SA, &ipsec_sa_vft);

	return 0;
	}

	VLIB_INIT_FUNCTION (ipsec_sa_interface_init);

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/