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

 /*
  * ipsec.c : IPSEC module functions
  *
  * 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/vnet.h>
 #include <vnet/api_errno.h>
 #include <vnet/ip/ip.h>
 #include <vnet/interface.h>
 #include <vnet/udp/udp.h>

 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
 #include <vnet/ipsec/ah.h>

 ipsec_main_t ipsec_main;

 static clib_error_t *
 ipsec_check_ah_support (ipsec_sa_t * sa)
 {
   ipsec_main_t *im = &ipsec_main;

   if (sa->integ_alg == IPSEC_INTEG_ALG_NONE)
     return clib_error_return (0, "unsupported none integ-alg");

   if (!vnet_crypto_is_set_handler (im->integ_algs[sa->integ_alg].alg))
     return clib_error_return (0, "No crypto engine support for %U",
 			      format_ipsec_integ_alg, sa->integ_alg);

   return 0;
 }

 static clib_error_t *
 ipsec_check_esp_support (ipsec_sa_t * sa)
 {
   ipsec_main_t *im = &ipsec_main;

   if (IPSEC_INTEG_ALG_NONE != sa->integ_alg)
     {
       if (!vnet_crypto_is_set_handler (im->integ_algs[sa->integ_alg].alg))
 	return clib_error_return (0, "No crypto engine support for %U",
 				  format_ipsec_integ_alg, sa->integ_alg);
     }
   if (IPSEC_CRYPTO_ALG_NONE != sa->crypto_alg)
     {
       if (!vnet_crypto_is_set_handler (im->crypto_algs[sa->crypto_alg].alg))
 	return clib_error_return (0, "No crypto engine support for %U",
 				  format_ipsec_crypto_alg, sa->crypto_alg);
     }

   return (0);
 }

 clib_error_t *
 ipsec_add_del_sa_sess_cb (ipsec_main_t * im, u32 sa_index, u8 is_add)
 {
   ipsec_ah_backend_t *ah =
     pool_elt_at_index (im->ah_backends, im->ah_current_backend);
   if (ah->add_del_sa_sess_cb)
     {
       clib_error_t *err = ah->add_del_sa_sess_cb (sa_index, is_add);
       if (err)
 	return err;
     }
   ipsec_esp_backend_t *esp =
     pool_elt_at_index (im->esp_backends, im->esp_current_backend);
   if (esp->add_del_sa_sess_cb)
     {
       clib_error_t *err = esp->add_del_sa_sess_cb (sa_index, is_add);
       if (err)
 	return err;
     }
   return 0;
 }

 clib_error_t *
 ipsec_check_support_cb (ipsec_main_t * im, ipsec_sa_t * sa)
 {
   clib_error_t *error = 0;

   if (PREDICT_FALSE (sa->protocol == IPSEC_PROTOCOL_AH))
     {
       ipsec_ah_backend_t *ah =
 	pool_elt_at_index (im->ah_backends, im->ah_current_backend);
       ASSERT (ah->check_support_cb);
       error = ah->check_support_cb (sa);
     }
   else
     {
       ipsec_esp_backend_t *esp =
 	pool_elt_at_index (im->esp_backends, im->esp_current_backend);
       ASSERT (esp->check_support_cb);
       error = esp->check_support_cb (sa);
     }
   return error;
 }


 static void
 ipsec_add_node (vlib_main_t * vm, const char *node_name,
 		const char *prev_node_name, u32 * out_node_index,
 		u32 * out_next_index)
 {
   vlib_node_t *prev_node, *node;
   prev_node = vlib_get_node_by_name (vm, (u8 *) prev_node_name);
   ASSERT (prev_node);
   node = vlib_get_node_by_name (vm, (u8 *) node_name);
   ASSERT (node);
   *out_node_index = node->index;
   *out_next_index = vlib_node_add_next (vm, prev_node->index, node->index);
 }

 void
 ipsec_add_feature (const char *arc_name,
 		   const char *node_name, u32 * out_feature_index)
 {
   u8 arc;

   arc = vnet_get_feature_arc_index (arc_name);
   ASSERT (arc != (u8) ~ 0);
   *out_feature_index = vnet_get_feature_index (arc, node_name);
 }

 u32
 ipsec_register_ah_backend (vlib_main_t * vm, ipsec_main_t * im,
 			   const char *name,
 			   const char *ah4_encrypt_node_name,
 			   const char *ah4_decrypt_node_name,
 			   const char *ah6_encrypt_node_name,
 			   const char *ah6_decrypt_node_name,
 			   check_support_cb_t ah_check_support_cb,
 			   add_del_sa_sess_cb_t ah_add_del_sa_sess_cb)
 {
   ipsec_ah_backend_t *b;
   pool_get (im->ah_backends, b);
   b->name = format (0, "%s%c", name, 0);

   ipsec_add_node (vm, ah4_encrypt_node_name, "ipsec4-output-feature",
 		  &b->ah4_encrypt_node_index, &b->ah4_encrypt_next_index);
   ipsec_add_node (vm, ah4_decrypt_node_name, "ipsec4-input-feature",
 		  &b->ah4_decrypt_node_index, &b->ah4_decrypt_next_index);
   ipsec_add_node (vm, ah6_encrypt_node_name, "ipsec6-output-feature",
 		  &b->ah6_encrypt_node_index, &b->ah6_encrypt_next_index);
   ipsec_add_node (vm, ah6_decrypt_node_name, "ipsec6-input-feature",
 		  &b->ah6_decrypt_node_index, &b->ah6_decrypt_next_index);

   b->check_support_cb = ah_check_support_cb;
   b->add_del_sa_sess_cb = ah_add_del_sa_sess_cb;
   return b - im->ah_backends;
 }

 u32
 ipsec_register_esp_backend (vlib_main_t * vm, ipsec_main_t * im,
 			    const char *name,
 			    const char *esp4_encrypt_node_name,
 			    const char *esp4_encrypt_node_tun_name,
 			    const char *esp4_decrypt_node_name,
 			    const char *esp6_encrypt_node_name,
 			    const char *esp6_encrypt_node_tun_name,
 			    const char *esp6_decrypt_node_name,
 			    check_support_cb_t esp_check_support_cb,
 			    add_del_sa_sess_cb_t esp_add_del_sa_sess_cb)
 {
   ipsec_esp_backend_t *b;

   pool_get (im->esp_backends, b);
   b->name = format (0, "%s%c", name, 0);

   ipsec_add_node (vm, esp4_encrypt_node_name, "ipsec4-output-feature",
 		  &b->esp4_encrypt_node_index, &b->esp4_encrypt_next_index);
   ipsec_add_node (vm, esp4_decrypt_node_name, "ipsec4-input-feature",
 		  &b->esp4_decrypt_node_index, &b->esp4_decrypt_next_index);
   ipsec_add_node (vm, esp6_encrypt_node_name, "ipsec6-output-feature",
 		  &b->esp6_encrypt_node_index, &b->esp6_encrypt_next_index);
   ipsec_add_node (vm, esp6_decrypt_node_name, "ipsec6-input-feature",
 		  &b->esp6_decrypt_node_index, &b->esp6_decrypt_next_index);

   ipsec_add_feature ("ip4-output", esp4_encrypt_node_tun_name,
 		     &b->esp4_encrypt_tun_feature_index);
   ipsec_add_feature ("ip6-output", esp6_encrypt_node_tun_name,
 		     &b->esp6_encrypt_tun_feature_index);

   b->check_support_cb = esp_check_support_cb;
   b->add_del_sa_sess_cb = esp_add_del_sa_sess_cb;
   return b - im->esp_backends;
 }

 clib_error_t *
 ipsec_rsc_in_use (ipsec_main_t * im)
 {
   /* return an error is crypto resource are in use */
   if (pool_elts (im->sad) > 0)
     return clib_error_return (0,
 			      "%d SA entries configured",
 			      pool_elts (im->sad));

   if (pool_elts (im->tunnel_interfaces))
     return clib_error_return (0,
 			      "%d tunnel-interface entries configured",
 			      pool_elts (im->tunnel_interfaces));

   return (NULL);
 }

 int
 ipsec_select_ah_backend (ipsec_main_t * im, u32 backend_idx)
 {
   if (ipsec_rsc_in_use (im))
     return VNET_API_ERROR_RSRC_IN_USE;

   if (pool_is_free_index (im->ah_backends, backend_idx))
     return VNET_API_ERROR_INVALID_VALUE;

   ipsec_ah_backend_t *b = pool_elt_at_index (im->ah_backends, backend_idx);
   im->ah_current_backend = backend_idx;
   im->ah4_encrypt_node_index = b->ah4_encrypt_node_index;
   im->ah4_decrypt_node_index = b->ah4_decrypt_node_index;
   im->ah4_encrypt_next_index = b->ah4_encrypt_next_index;
   im->ah4_decrypt_next_index = b->ah4_decrypt_next_index;
   im->ah6_encrypt_node_index = b->ah6_encrypt_node_index;
   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;

   return 0;
 }

 int
 ipsec_select_esp_backend (ipsec_main_t * im, u32 backend_idx)
 {
   if (ipsec_rsc_in_use (im))
     return VNET_API_ERROR_RSRC_IN_USE;

   if (pool_is_free_index (im->esp_backends, backend_idx))
     return VNET_API_ERROR_INVALID_VALUE;

   ipsec_esp_backend_t *b = pool_elt_at_index (im->esp_backends, backend_idx);
   im->esp_current_backend = backend_idx;
   im->esp4_encrypt_node_index = b->esp4_encrypt_node_index;
   im->esp4_decrypt_node_index = b->esp4_decrypt_node_index;
   im->esp4_encrypt_next_index = b->esp4_encrypt_next_index;
   im->esp4_decrypt_next_index = b->esp4_decrypt_next_index;
   im->esp6_encrypt_node_index = b->esp6_encrypt_node_index;
   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;

   im->esp4_encrypt_tun_feature_index = b->esp4_encrypt_tun_feature_index;
   im->esp6_encrypt_tun_feature_index = b->esp6_encrypt_tun_feature_index;

   return 0;
 }

 static clib_error_t *
 ipsec_init (vlib_main_t * vm)
 {
   clib_error_t *error;
   ipsec_main_t *im = &ipsec_main;
   ipsec_main_crypto_alg_t *a;

   /* Backend registration requires the feature arcs to be set up */
   if ((error = vlib_call_init_function (vm, vnet_feature_init)))
     return (error);

   im->vnet_main = vnet_get_main ();
   im->vlib_main = vm;

   im->spd_index_by_spd_id = hash_create (0, sizeof (uword));
   im->sa_index_by_sa_id = hash_create (0, sizeof (uword));
   im->spd_index_by_sw_if_index = hash_create (0, sizeof (uword));

   vlib_node_t *node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
   ASSERT (node);
   im->error_drop_node_index = node->index;

   u32 idx = ipsec_register_ah_backend (vm, im, "crypto engine backend",
 				       "ah4-encrypt",
 				       "ah4-decrypt",
 				       "ah6-encrypt",
 				       "ah6-decrypt",
 				       ipsec_check_ah_support,
 				       NULL);

   im->ah_default_backend = idx;
   int rv = ipsec_select_ah_backend (im, idx);
   ASSERT (0 == rv);
   (void) (rv);			// avoid warning

   idx = ipsec_register_esp_backend (vm, im, "crypto engine backend",
 				    "esp4-encrypt",
 				    "esp4-encrypt-tun",
 				    "esp4-decrypt",
 				    "esp6-encrypt",
 				    "esp6-encrypt-tun",
 				    "esp6-decrypt",
 				    ipsec_check_esp_support, NULL);
   im->esp_default_backend = idx;

   rv = ipsec_select_esp_backend (im, idx);
   ASSERT (0 == rv);
   (void) (rv);			// avoid warning

   if ((error = vlib_call_init_function (vm, ipsec_cli_init)))
     return error;

   if ((error = vlib_call_init_function (vm, ipsec_tunnel_if_init)))
     return error;

   vec_validate (im->crypto_algs, IPSEC_CRYPTO_N_ALG - 1);

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_NONE;
   a->enc_op_id = VNET_CRYPTO_OP_NONE;
   a->dec_op_id = VNET_CRYPTO_OP_NONE;
   a->alg = VNET_CRYPTO_ALG_NONE;
   a->iv_size = 0;
   a->block_size = 1;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_DES_CBC;
   a->enc_op_id = VNET_CRYPTO_OP_DES_CBC_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_DES_CBC_DEC;
   a->alg = VNET_CRYPTO_ALG_DES_CBC;
   a->iv_size = a->block_size = 8;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_3DES_CBC;
   a->enc_op_id = VNET_CRYPTO_OP_3DES_CBC_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_3DES_CBC_DEC;
   a->alg = VNET_CRYPTO_ALG_3DES_CBC;
   a->iv_size = a->block_size = 8;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_128;
   a->enc_op_id = VNET_CRYPTO_OP_AES_128_CBC_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_128_CBC_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_128_CBC;
   a->iv_size = a->block_size = 16;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_192;
   a->enc_op_id = VNET_CRYPTO_OP_AES_192_CBC_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_192_CBC_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_192_CBC;
   a->iv_size = a->block_size = 16;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_256;
   a->enc_op_id = VNET_CRYPTO_OP_AES_256_CBC_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_256_CBC_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_256_CBC;
   a->iv_size = a->block_size = 16;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_128;
   a->enc_op_id = VNET_CRYPTO_OP_AES_128_GCM_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_128_GCM_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_128_GCM;
   a->iv_size = a->block_size = 8;
   a->icv_size = 16;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_192;
   a->enc_op_id = VNET_CRYPTO_OP_AES_192_GCM_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_192_GCM_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_192_GCM;
   a->iv_size = a->block_size = 8;
   a->icv_size = 16;

   a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_256;
   a->enc_op_id = VNET_CRYPTO_OP_AES_256_GCM_ENC;
   a->dec_op_id = VNET_CRYPTO_OP_AES_256_GCM_DEC;
   a->alg = VNET_CRYPTO_ALG_AES_256_GCM;
   a->iv_size = a->block_size = 8;
   a->icv_size = 16;

   vec_validate (im->integ_algs, IPSEC_INTEG_N_ALG - 1);
   ipsec_main_integ_alg_t *i;

   i = &im->integ_algs[IPSEC_INTEG_ALG_MD5_96];
   i->op_id = VNET_CRYPTO_OP_MD5_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_MD5;
   i->icv_size = 12;

   i = &im->integ_algs[IPSEC_INTEG_ALG_SHA1_96];
   i->op_id = VNET_CRYPTO_OP_SHA1_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_SHA1;
   i->icv_size = 12;

   i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_256_96];
   i->op_id = VNET_CRYPTO_OP_SHA1_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_SHA256;
   i->icv_size = 12;

   i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_256_128];
   i->op_id = VNET_CRYPTO_OP_SHA256_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_SHA256;
   i->icv_size = 16;

   i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_384_192];
   i->op_id = VNET_CRYPTO_OP_SHA384_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_SHA384;
   i->icv_size = 24;

   i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_512_256];
   i->op_id = VNET_CRYPTO_OP_SHA512_HMAC;
   i->alg = VNET_CRYPTO_ALG_HMAC_SHA512;
   i->icv_size = 32;

   vec_validate_aligned (im->ptd, vlib_num_workers (), CLIB_CACHE_LINE_BYTES);

   return 0;
 }

 VLIB_INIT_FUNCTION (ipsec_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* ipsec.c : IPSEC module functions
	*
	* 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/vnet.h>
	#include <vnet/api_errno.h>
	#include <vnet/ip/ip.h>
	#include <vnet/interface.h>
	#include <vnet/udp/udp.h>

	#include <vnet/ipsec/ipsec.h>
	#include <vnet/ipsec/esp.h>
	#include <vnet/ipsec/ah.h>

	ipsec_main_t ipsec_main;

	static clib_error_t *
	ipsec_check_ah_support (ipsec_sa_t * sa)
	{
	ipsec_main_t *im = &ipsec_main;

	if (sa->integ_alg == IPSEC_INTEG_ALG_NONE)
	return clib_error_return (0, "unsupported none integ-alg");

	if (!vnet_crypto_is_set_handler (im->integ_algs[sa->integ_alg].alg))
	return clib_error_return (0, "No crypto engine support for %U",
	format_ipsec_integ_alg, sa->integ_alg);

	return 0;
	}

	static clib_error_t *
	ipsec_check_esp_support (ipsec_sa_t * sa)
	{
	ipsec_main_t *im = &ipsec_main;

	if (IPSEC_INTEG_ALG_NONE != sa->integ_alg)
	{
	if (!vnet_crypto_is_set_handler (im->integ_algs[sa->integ_alg].alg))
	return clib_error_return (0, "No crypto engine support for %U",
	format_ipsec_integ_alg, sa->integ_alg);
	}
	if (IPSEC_CRYPTO_ALG_NONE != sa->crypto_alg)
	{
	if (!vnet_crypto_is_set_handler (im->crypto_algs[sa->crypto_alg].alg))
	return clib_error_return (0, "No crypto engine support for %U",
	format_ipsec_crypto_alg, sa->crypto_alg);
	}

	return (0);
	}

	clib_error_t *
	ipsec_add_del_sa_sess_cb (ipsec_main_t * im, u32 sa_index, u8 is_add)
	{
	ipsec_ah_backend_t *ah =
	pool_elt_at_index (im->ah_backends, im->ah_current_backend);
	if (ah->add_del_sa_sess_cb)
	{
	clib_error_t *err = ah->add_del_sa_sess_cb (sa_index, is_add);
	if (err)
	return err;
	}
	ipsec_esp_backend_t *esp =
	pool_elt_at_index (im->esp_backends, im->esp_current_backend);
	if (esp->add_del_sa_sess_cb)
	{
	clib_error_t *err = esp->add_del_sa_sess_cb (sa_index, is_add);
	if (err)
	return err;
	}
	return 0;
	}

	clib_error_t *
	ipsec_check_support_cb (ipsec_main_t * im, ipsec_sa_t * sa)
	{
	clib_error_t *error = 0;

	if (PREDICT_FALSE (sa->protocol == IPSEC_PROTOCOL_AH))
	{
	ipsec_ah_backend_t *ah =
	pool_elt_at_index (im->ah_backends, im->ah_current_backend);
	ASSERT (ah->check_support_cb);
	error = ah->check_support_cb (sa);
	}
	else
	{
	ipsec_esp_backend_t *esp =
	pool_elt_at_index (im->esp_backends, im->esp_current_backend);
	ASSERT (esp->check_support_cb);
	error = esp->check_support_cb (sa);
	}
	return error;
	}


	static void
	ipsec_add_node (vlib_main_t * vm, const char *node_name,
	const char prev_node_name, u32 out_node_index,
	u32 * out_next_index)
	{
	vlib_node_t prev_node, node;
	prev_node = vlib_get_node_by_name (vm, (u8 *) prev_node_name);
	ASSERT (prev_node);
	node = vlib_get_node_by_name (vm, (u8 *) node_name);
	ASSERT (node);
	*out_node_index = node->index;
	*out_next_index = vlib_node_add_next (vm, prev_node->index, node->index);
	}

	void
	ipsec_add_feature (const char *arc_name,
	const char node_name, u32 out_feature_index)
	{
	u8 arc;

	arc = vnet_get_feature_arc_index (arc_name);
	ASSERT (arc != (u8) ~ 0);
	*out_feature_index = vnet_get_feature_index (arc, node_name);
	}

	u32
	ipsec_register_ah_backend (vlib_main_t * vm, ipsec_main_t * im,
	const char *name,
	const char *ah4_encrypt_node_name,
	const char *ah4_decrypt_node_name,
	const char *ah6_encrypt_node_name,
	const char *ah6_decrypt_node_name,
	check_support_cb_t ah_check_support_cb,
	add_del_sa_sess_cb_t ah_add_del_sa_sess_cb)
	{
	ipsec_ah_backend_t *b;
	pool_get (im->ah_backends, b);
	b->name = format (0, "%s%c", name, 0);

	ipsec_add_node (vm, ah4_encrypt_node_name, "ipsec4-output-feature",
	&b->ah4_encrypt_node_index, &b->ah4_encrypt_next_index);
	ipsec_add_node (vm, ah4_decrypt_node_name, "ipsec4-input-feature",
	&b->ah4_decrypt_node_index, &b->ah4_decrypt_next_index);
	ipsec_add_node (vm, ah6_encrypt_node_name, "ipsec6-output-feature",
	&b->ah6_encrypt_node_index, &b->ah6_encrypt_next_index);
	ipsec_add_node (vm, ah6_decrypt_node_name, "ipsec6-input-feature",
	&b->ah6_decrypt_node_index, &b->ah6_decrypt_next_index);

	b->check_support_cb = ah_check_support_cb;
	b->add_del_sa_sess_cb = ah_add_del_sa_sess_cb;
	return b - im->ah_backends;
	}

	u32
	ipsec_register_esp_backend (vlib_main_t * vm, ipsec_main_t * im,
	const char *name,
	const char *esp4_encrypt_node_name,
	const char *esp4_encrypt_node_tun_name,
	const char *esp4_decrypt_node_name,
	const char *esp6_encrypt_node_name,
	const char *esp6_encrypt_node_tun_name,
	const char *esp6_decrypt_node_name,
	check_support_cb_t esp_check_support_cb,
	add_del_sa_sess_cb_t esp_add_del_sa_sess_cb)
	{
	ipsec_esp_backend_t *b;

	pool_get (im->esp_backends, b);
	b->name = format (0, "%s%c", name, 0);

	ipsec_add_node (vm, esp4_encrypt_node_name, "ipsec4-output-feature",
	&b->esp4_encrypt_node_index, &b->esp4_encrypt_next_index);
	ipsec_add_node (vm, esp4_decrypt_node_name, "ipsec4-input-feature",
	&b->esp4_decrypt_node_index, &b->esp4_decrypt_next_index);
	ipsec_add_node (vm, esp6_encrypt_node_name, "ipsec6-output-feature",
	&b->esp6_encrypt_node_index, &b->esp6_encrypt_next_index);
	ipsec_add_node (vm, esp6_decrypt_node_name, "ipsec6-input-feature",
	&b->esp6_decrypt_node_index, &b->esp6_decrypt_next_index);

	ipsec_add_feature ("ip4-output", esp4_encrypt_node_tun_name,
	&b->esp4_encrypt_tun_feature_index);
	ipsec_add_feature ("ip6-output", esp6_encrypt_node_tun_name,
	&b->esp6_encrypt_tun_feature_index);

	b->check_support_cb = esp_check_support_cb;
	b->add_del_sa_sess_cb = esp_add_del_sa_sess_cb;
	return b - im->esp_backends;
	}

	clib_error_t *
	ipsec_rsc_in_use (ipsec_main_t * im)
	{
	/* return an error is crypto resource are in use */
	if (pool_elts (im->sad) > 0)
	return clib_error_return (0,
	"%d SA entries configured",
	pool_elts (im->sad));

	if (pool_elts (im->tunnel_interfaces))
	return clib_error_return (0,
	"%d tunnel-interface entries configured",
	pool_elts (im->tunnel_interfaces));

	return (NULL);
	}

	int
	ipsec_select_ah_backend (ipsec_main_t * im, u32 backend_idx)
	{
	if (ipsec_rsc_in_use (im))
	return VNET_API_ERROR_RSRC_IN_USE;

	if (pool_is_free_index (im->ah_backends, backend_idx))
	return VNET_API_ERROR_INVALID_VALUE;

	ipsec_ah_backend_t *b = pool_elt_at_index (im->ah_backends, backend_idx);
	im->ah_current_backend = backend_idx;
	im->ah4_encrypt_node_index = b->ah4_encrypt_node_index;
	im->ah4_decrypt_node_index = b->ah4_decrypt_node_index;
	im->ah4_encrypt_next_index = b->ah4_encrypt_next_index;
	im->ah4_decrypt_next_index = b->ah4_decrypt_next_index;
	im->ah6_encrypt_node_index = b->ah6_encrypt_node_index;
	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;

	return 0;
	}

	int
	ipsec_select_esp_backend (ipsec_main_t * im, u32 backend_idx)
	{
	if (ipsec_rsc_in_use (im))
	return VNET_API_ERROR_RSRC_IN_USE;

	if (pool_is_free_index (im->esp_backends, backend_idx))
	return VNET_API_ERROR_INVALID_VALUE;

	ipsec_esp_backend_t *b = pool_elt_at_index (im->esp_backends, backend_idx);
	im->esp_current_backend = backend_idx;
	im->esp4_encrypt_node_index = b->esp4_encrypt_node_index;
	im->esp4_decrypt_node_index = b->esp4_decrypt_node_index;
	im->esp4_encrypt_next_index = b->esp4_encrypt_next_index;
	im->esp4_decrypt_next_index = b->esp4_decrypt_next_index;
	im->esp6_encrypt_node_index = b->esp6_encrypt_node_index;
	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;

	im->esp4_encrypt_tun_feature_index = b->esp4_encrypt_tun_feature_index;
	im->esp6_encrypt_tun_feature_index = b->esp6_encrypt_tun_feature_index;

	return 0;
	}

	static clib_error_t *
	ipsec_init (vlib_main_t * vm)
	{
	clib_error_t *error;
	ipsec_main_t *im = &ipsec_main;
	ipsec_main_crypto_alg_t *a;

	/* Backend registration requires the feature arcs to be set up */
	if ((error = vlib_call_init_function (vm, vnet_feature_init)))
	return (error);

	im->vnet_main = vnet_get_main ();
	im->vlib_main = vm;

	im->spd_index_by_spd_id = hash_create (0, sizeof (uword));
	im->sa_index_by_sa_id = hash_create (0, sizeof (uword));
	im->spd_index_by_sw_if_index = hash_create (0, sizeof (uword));

	vlib_node_t node = vlib_get_node_by_name (vm, (u8 ) "error-drop");
	ASSERT (node);
	im->error_drop_node_index = node->index;

	u32 idx = ipsec_register_ah_backend (vm, im, "crypto engine backend",
	"ah4-encrypt",
	"ah4-decrypt",
	"ah6-encrypt",
	"ah6-decrypt",
	ipsec_check_ah_support,
	NULL);

	im->ah_default_backend = idx;
	int rv = ipsec_select_ah_backend (im, idx);
	ASSERT (0 == rv);
	(void) (rv); // avoid warning

	idx = ipsec_register_esp_backend (vm, im, "crypto engine backend",
	"esp4-encrypt",
	"esp4-encrypt-tun",
	"esp4-decrypt",
	"esp6-encrypt",
	"esp6-encrypt-tun",
	"esp6-decrypt",
	ipsec_check_esp_support, NULL);
	im->esp_default_backend = idx;

	rv = ipsec_select_esp_backend (im, idx);
	ASSERT (0 == rv);
	(void) (rv); // avoid warning

	if ((error = vlib_call_init_function (vm, ipsec_cli_init)))
	return error;

	if ((error = vlib_call_init_function (vm, ipsec_tunnel_if_init)))
	return error;

	vec_validate (im->crypto_algs, IPSEC_CRYPTO_N_ALG - 1);

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_NONE;
	a->enc_op_id = VNET_CRYPTO_OP_NONE;
	a->dec_op_id = VNET_CRYPTO_OP_NONE;
	a->alg = VNET_CRYPTO_ALG_NONE;
	a->iv_size = 0;
	a->block_size = 1;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_DES_CBC;
	a->enc_op_id = VNET_CRYPTO_OP_DES_CBC_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_DES_CBC_DEC;
	a->alg = VNET_CRYPTO_ALG_DES_CBC;
	a->iv_size = a->block_size = 8;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_3DES_CBC;
	a->enc_op_id = VNET_CRYPTO_OP_3DES_CBC_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_3DES_CBC_DEC;
	a->alg = VNET_CRYPTO_ALG_3DES_CBC;
	a->iv_size = a->block_size = 8;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_128;
	a->enc_op_id = VNET_CRYPTO_OP_AES_128_CBC_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_128_CBC_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_128_CBC;
	a->iv_size = a->block_size = 16;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_192;
	a->enc_op_id = VNET_CRYPTO_OP_AES_192_CBC_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_192_CBC_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_192_CBC;
	a->iv_size = a->block_size = 16;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_CBC_256;
	a->enc_op_id = VNET_CRYPTO_OP_AES_256_CBC_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_256_CBC_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_256_CBC;
	a->iv_size = a->block_size = 16;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_128;
	a->enc_op_id = VNET_CRYPTO_OP_AES_128_GCM_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_128_GCM_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_128_GCM;
	a->iv_size = a->block_size = 8;
	a->icv_size = 16;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_192;
	a->enc_op_id = VNET_CRYPTO_OP_AES_192_GCM_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_192_GCM_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_192_GCM;
	a->iv_size = a->block_size = 8;
	a->icv_size = 16;

	a = im->crypto_algs + IPSEC_CRYPTO_ALG_AES_GCM_256;
	a->enc_op_id = VNET_CRYPTO_OP_AES_256_GCM_ENC;
	a->dec_op_id = VNET_CRYPTO_OP_AES_256_GCM_DEC;
	a->alg = VNET_CRYPTO_ALG_AES_256_GCM;
	a->iv_size = a->block_size = 8;
	a->icv_size = 16;

	vec_validate (im->integ_algs, IPSEC_INTEG_N_ALG - 1);
	ipsec_main_integ_alg_t *i;

	i = &im->integ_algs[IPSEC_INTEG_ALG_MD5_96];
	i->op_id = VNET_CRYPTO_OP_MD5_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_MD5;
	i->icv_size = 12;

	i = &im->integ_algs[IPSEC_INTEG_ALG_SHA1_96];
	i->op_id = VNET_CRYPTO_OP_SHA1_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_SHA1;
	i->icv_size = 12;

	i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_256_96];
	i->op_id = VNET_CRYPTO_OP_SHA1_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_SHA256;
	i->icv_size = 12;

	i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_256_128];
	i->op_id = VNET_CRYPTO_OP_SHA256_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_SHA256;
	i->icv_size = 16;

	i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_384_192];
	i->op_id = VNET_CRYPTO_OP_SHA384_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_SHA384;
	i->icv_size = 24;

	i = &im->integ_algs[IPSEC_INTEG_ALG_SHA_512_256];
	i->op_id = VNET_CRYPTO_OP_SHA512_HMAC;
	i->alg = VNET_CRYPTO_ALG_HMAC_SHA512;
	i->icv_size = 32;

	vec_validate_aligned (im->ptd, vlib_num_workers (), CLIB_CACHE_LINE_BYTES);

	return 0;
	}

	VLIB_INIT_FUNCTION (ipsec_init);

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