src/vnet/ipsec/ipsec_sa.h - 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.
  */
 #ifndef __IPSEC_SPD_SA_H__
 #define __IPSEC_SPD_SA_H__

 #include <vlib/vlib.h>
 #include <vnet/ip/ip.h>
 #include <vnet/fib/fib_node.h>

 #define foreach_ipsec_crypto_alg    \
   _ (0, NONE, "none")               \
   _ (1, AES_CBC_128, "aes-cbc-128") \
   _ (2, AES_CBC_192, "aes-cbc-192") \
   _ (3, AES_CBC_256, "aes-cbc-256") \
   _ (4, AES_CTR_128, "aes-ctr-128") \
   _ (5, AES_CTR_192, "aes-ctr-192") \
   _ (6, AES_CTR_256, "aes-ctr-256") \
   _ (7, AES_GCM_128, "aes-gcm-128") \
   _ (8, AES_GCM_192, "aes-gcm-192") \
   _ (9, AES_GCM_256, "aes-gcm-256") \
   _ (10, DES_CBC, "des-cbc")        \
   _ (11, 3DES_CBC, "3des-cbc")

 typedef enum
 {
 #define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
   foreach_ipsec_crypto_alg
 #undef _
     IPSEC_CRYPTO_N_ALG,
 } ipsec_crypto_alg_t;

 #define IPSEC_CRYPTO_ALG_IS_GCM(_alg)                     \
   (((_alg == IPSEC_CRYPTO_ALG_AES_GCM_128) ||             \
     (_alg == IPSEC_CRYPTO_ALG_AES_GCM_192) ||             \
     (_alg == IPSEC_CRYPTO_ALG_AES_GCM_256)))

 #define foreach_ipsec_integ_alg                                            \
   _ (0, NONE, "none")                                                      \
   _ (1, MD5_96, "md5-96")           /* RFC2403 */                          \
   _ (2, SHA1_96, "sha1-96")         /* RFC2404 */                          \
   _ (3, SHA_256_96, "sha-256-96")   /* draft-ietf-ipsec-ciph-sha-256-00 */ \
   _ (4, SHA_256_128, "sha-256-128") /* RFC4868 */                          \
   _ (5, SHA_384_192, "sha-384-192") /* RFC4868 */                          \
   _ (6, SHA_512_256, "sha-512-256")	/* RFC4868 */

 typedef enum
 {
 #define _(v, f, s) IPSEC_INTEG_ALG_##f = v,
   foreach_ipsec_integ_alg
 #undef _
     IPSEC_INTEG_N_ALG,
 } ipsec_integ_alg_t;

 typedef enum
 {
   IPSEC_PROTOCOL_AH = 0,
   IPSEC_PROTOCOL_ESP = 1
 } ipsec_protocol_t;

 #define IPSEC_KEY_MAX_LEN 128
 typedef struct ipsec_key_t_
 {
   u8 len;
   u8 data[IPSEC_KEY_MAX_LEN];
 } ipsec_key_t;

 /*
  * Enable extended sequence numbers
  * Enable Anti-replay
  * IPsec tunnel mode if non-zero, else transport mode
  * IPsec tunnel mode is IPv6 if non-zero,
  * else IPv4 tunnel only valid if is_tunnel is non-zero
  * enable UDP encapsulation for NAT traversal
  */
 #define foreach_ipsec_sa_flags                            \
   _ (0, NONE, "none")                                     \
   _ (1, USE_ESN, "esn")                                   \
   _ (2, USE_ANTI_REPLAY, "anti-replay")                   \
   _ (4, IS_TUNNEL, "tunnel")                              \
   _ (8, IS_TUNNEL_V6, "tunnel-v6")                        \
   _ (16, UDP_ENCAP, "udp-encap")                          \
   _ (32, IS_PROTECT, "Protect")                           \
   _ (64, IS_INBOUND, "inbound")                           \
   _ (128, IS_AEAD, "aead")                                \

 typedef enum ipsec_sad_flags_t_
 {
 #define _(v, f, s) IPSEC_SA_FLAG_##f = v,
   foreach_ipsec_sa_flags
 #undef _
 } __clib_packed ipsec_sa_flags_t;

 STATIC_ASSERT (sizeof (ipsec_sa_flags_t) == 1, "IPSEC SA flags > 1 byte");

 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);

   /* flags */
   ipsec_sa_flags_t flags;

   u8 crypto_iv_size;
   u8 crypto_block_size;
   u8 integ_icv_size;
   u32 encrypt_thread_index;
   u32 decrypt_thread_index;
   u32 spi;
   u32 seq;
   u32 seq_hi;
   u32 last_seq;
   u32 last_seq_hi;
   u64 replay_window;
   dpo_id_t dpo;

   vnet_crypto_key_index_t crypto_key_index;
   vnet_crypto_key_index_t integ_key_index;
   vnet_crypto_op_id_t crypto_enc_op_id:16;
   vnet_crypto_op_id_t crypto_dec_op_id:16;
   vnet_crypto_op_id_t integ_op_id:16;

   /* data accessed by dataplane code should be above this comment */
     CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

   union
   {
     ip4_header_t ip4_hdr;
     ip6_header_t ip6_hdr;
   };
   udp_header_t udp_hdr;

   fib_node_t node;
   u32 id;
   u32 stat_index;
   ipsec_protocol_t protocol;

   ipsec_crypto_alg_t crypto_alg;
   ipsec_key_t crypto_key;
   vnet_crypto_alg_t crypto_calg;

   ipsec_integ_alg_t integ_alg;
   ipsec_key_t integ_key;
   vnet_crypto_alg_t integ_calg;

   ip46_address_t tunnel_src_addr;
   ip46_address_t tunnel_dst_addr;

   fib_node_index_t fib_entry_index;
   u32 sibling;

   u32 tx_fib_index;

   /* Salt used in GCM modes - stored in network byte order */
   u32 salt;
   u64 gcm_iv_counter;
 } ipsec_sa_t;

 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);

 #define _(a,v,s)                                                        \
   always_inline int                                                     \
   ipsec_sa_is_set_##v (const ipsec_sa_t *sa) {                          \
     return (sa->flags & IPSEC_SA_FLAG_##v);                             \
   }
 foreach_ipsec_sa_flags
 #undef _
 #define _(a,v,s)                                                        \
   always_inline int                                                     \
   ipsec_sa_set_##v (ipsec_sa_t *sa) {                                   \
     return (sa->flags |= IPSEC_SA_FLAG_##v);                            \
   }
   foreach_ipsec_sa_flags
 #undef _
 #define _(a,v,s)                                                        \
   always_inline int                                                     \
   ipsec_sa_unset_##v (ipsec_sa_t *sa) {                                 \
     return (sa->flags &= ~IPSEC_SA_FLAG_##v);                           \
   }
   foreach_ipsec_sa_flags
 #undef _
 /**
  * @brief
  * SA packet & bytes counters
  */
 extern vlib_combined_counter_main_t ipsec_sa_counters;

 extern void ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len);

 extern 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 * tunnel_src_addr,
 				  const ip46_address_t * tunnel_dst_addr,
 				  u32 * sa_index);
 extern index_t ipsec_sa_find_and_lock (u32 id);
 extern int ipsec_sa_unlock_id (u32 id);
 extern void ipsec_sa_unlock (index_t sai);
 extern void ipsec_sa_lock (index_t sai);
 extern void ipsec_sa_clear (index_t sai);
 extern void ipsec_sa_set_crypto_alg (ipsec_sa_t * sa,
 				     ipsec_crypto_alg_t crypto_alg);
 extern void ipsec_sa_set_integ_alg (ipsec_sa_t * sa,
 				    ipsec_integ_alg_t integ_alg);

 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);
 extern u8 *format_ipsec_key (u8 * s, va_list * args);
 extern uword unformat_ipsec_crypto_alg (unformat_input_t * input,
 					va_list * args);
 extern uword unformat_ipsec_integ_alg (unformat_input_t * input,
 				       va_list * args);
 extern uword unformat_ipsec_key (unformat_input_t * input, va_list * args);

 /*
  * Anti Replay definitions
  */

 #define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (64)
 #define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE-1)

 /*
  * sequence number less than the lower bound are outside of the window
  * From RFC4303 Appendix A:
  *  Bl = Tl - W + 1
  */
 #define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND(_tl) (_tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1)

 /*
  * Anti replay check.
  *  inputs need to be in host byte order.
  */
 always_inline int
 ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq)
 {
   u32 diff, tl, th;

   if ((sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
     return 0;

   if (!ipsec_sa_is_set_USE_ESN (sa))
     {
       if (PREDICT_TRUE (seq > sa->last_seq))
 	return 0;

       diff = sa->last_seq - seq;

       if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff)
 	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
       else
 	return 1;

       return 0;
     }

   tl = sa->last_seq;
   th = sa->last_seq_hi;
   diff = tl - seq;

   if (PREDICT_TRUE (tl >= (IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX)))
     {
       /*
        * the last sequence number VPP recieved is more than one
        * window size greater than zero.
        * Case A from RFC4303 Appendix A.
        */
       if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
 	{
 	  /*
 	   * the received sequence number is lower than the lower bound
 	   * of the window, this could mean either a replay packet or that
 	   * the high sequence number has wrapped. if it decrypts corrently
 	   * then it's the latter.
 	   */
 	  sa->seq_hi = th + 1;
 	  return 0;
 	}
       else
 	{
 	  /*
 	   * the recieved sequence number greater than the low
 	   * end of the window.
 	   */
 	  sa->seq_hi = th;
 	  if (seq <= tl)
 	    /*
 	     * The recieved seq number is within bounds of the window
 	     * check if it's a duplicate
 	     */
 	    return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
 	  else
 	    /*
 	     * The received sequence number is greater than the window
 	     * upper bound. this packet will move the window along, assuming
 	     * it decrypts correctly.
 	     */
 	    return 0;
 	}
     }
   else
     {
       /*
        * the last sequence number VPP recieved is within one window
        * size of zero, i.e. 0 < TL < WINDOW_SIZE, the lower bound is thus a
        * large sequence number.
        * Note that the check below uses unsiged integer arthimetic, so the
        * RHS will be a larger number.
        * Case B from RFC4303 Appendix A.
        */
       if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
 	{
 	  /*
 	   * the sequence number is less than the lower bound.
 	   */
 	  if (seq <= tl)
 	    {
 	      /*
 	       * the packet is within the window upper bound.
 	       * check for duplicates.
 	       */
 	      sa->seq_hi = th;
 	      return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
 	    }
 	  else
 	    {
 	      /*
 	       * the packet is less the window lower bound or greater than
 	       * the higher bound, depending on how you look at it...
 	       * We're assuming, given that the last sequence number received,
 	       * TL < WINDOW_SIZE, that a largeer seq num is more likely to be
 	       * a packet that moves the window forward, than a packet that has
 	       * wrapped the high sequence again. If it were the latter then
 	       * we've lost close to 2^32 packets.
 	       */
 	      sa->seq_hi = th;
 	      return 0;
 	    }
 	}
       else
 	{
 	  /*
 	   * the packet seq number is between the lower bound (a large nubmer)
 	   * and MAX_SEQ_NUM. This is in the window since the window upper bound
 	   * tl > 0.
 	   * However, since TL is the other side of 0 to the received
 	   * packet, the SA has moved on to a higher sequence number.
 	   */
 	  sa->seq_hi = th - 1;
 	  return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
 	}
     }

   return 0;
 }

 /*
  * Anti replay window advance
  *  inputs need to be in host byte order.
  */
 always_inline void
 ipsec_sa_anti_replay_advance (ipsec_sa_t * sa, u32 seq)
 {
   u32 pos;
   if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
     return;

   if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ESN))
     {
       int wrap = sa->seq_hi - sa->last_seq_hi;

       if (wrap == 0 && seq > sa->last_seq)
 	{
 	  pos = seq - sa->last_seq;
 	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
 	    sa->replay_window = ((sa->replay_window) << pos) | 1;
 	  else
 	    sa->replay_window = 1;
 	  sa->last_seq = seq;
 	}
       else if (wrap > 0)
 	{
 	  pos = ~seq + sa->last_seq + 1;
 	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
 	    sa->replay_window = ((sa->replay_window) << pos) | 1;
 	  else
 	    sa->replay_window = 1;
 	  sa->last_seq = seq;
 	  sa->last_seq_hi = sa->seq_hi;
 	}
       else if (wrap < 0)
 	{
 	  pos = ~seq + sa->last_seq + 1;
 	  sa->replay_window |= (1ULL << pos);
 	}
       else
 	{
 	  pos = sa->last_seq - seq;
 	  sa->replay_window |= (1ULL << pos);
 	}
     }
   else
     {
       if (seq > sa->last_seq)
 	{
 	  pos = seq - sa->last_seq;
 	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
 	    sa->replay_window = ((sa->replay_window) << pos) | 1;
 	  else
 	    sa->replay_window = 1;
 	  sa->last_seq = seq;
 	}
       else
 	{
 	  pos = sa->last_seq - seq;
 	  sa->replay_window |= (1ULL << pos);
 	}
     }
 }


 /*
  * Makes choice for thread_id should be assigned.
  *  if input ~0, gets random worker_id based on unix_time_now_nsec
 */
 always_inline u32
 ipsec_sa_assign_thread (u32 thread_id)
 {
   return ((thread_id) ? thread_id
 	  : (unix_time_now_nsec () % vlib_num_workers ()) + 1);
 }

 #endif /* __IPSEC_SPD_SA_H__ */

 /*
  * 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.
	*/
	#ifndef __IPSEC_SPD_SA_H__
	#define __IPSEC_SPD_SA_H__

	#include <vlib/vlib.h>
	#include <vnet/ip/ip.h>
	#include <vnet/fib/fib_node.h>

	#define foreach_ipsec_crypto_alg \
	_ (0, NONE, "none") \
	_ (1, AES_CBC_128, "aes-cbc-128") \
	_ (2, AES_CBC_192, "aes-cbc-192") \
	_ (3, AES_CBC_256, "aes-cbc-256") \
	_ (4, AES_CTR_128, "aes-ctr-128") \
	_ (5, AES_CTR_192, "aes-ctr-192") \
	_ (6, AES_CTR_256, "aes-ctr-256") \
	_ (7, AES_GCM_128, "aes-gcm-128") \
	_ (8, AES_GCM_192, "aes-gcm-192") \
	_ (9, AES_GCM_256, "aes-gcm-256") \
	_ (10, DES_CBC, "des-cbc") \
	_ (11, 3DES_CBC, "3des-cbc")

	typedef enum
	{
	#define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
	foreach_ipsec_crypto_alg
	#undef _
	IPSEC_CRYPTO_N_ALG,
	} ipsec_crypto_alg_t;

	#define IPSEC_CRYPTO_ALG_IS_GCM(_alg) \
	(((_alg == IPSEC_CRYPTO_ALG_AES_GCM_128) \|\| \
	(_alg == IPSEC_CRYPTO_ALG_AES_GCM_192) \|\| \
	(_alg == IPSEC_CRYPTO_ALG_AES_GCM_256)))

	#define foreach_ipsec_integ_alg \
	_ (0, NONE, "none") \
	_ (1, MD5_96, "md5-96") /* RFC2403 */ \
	_ (2, SHA1_96, "sha1-96") /* RFC2404 */ \
	_ (3, SHA_256_96, "sha-256-96") /* draft-ietf-ipsec-ciph-sha-256-00 */ \
	_ (4, SHA_256_128, "sha-256-128") /* RFC4868 */ \
	_ (5, SHA_384_192, "sha-384-192") /* RFC4868 */ \
	_ (6, SHA_512_256, "sha-512-256") /* RFC4868 */

	typedef enum
	{
	#define _(v, f, s) IPSEC_INTEG_ALG_##f = v,
	foreach_ipsec_integ_alg
	#undef _
	IPSEC_INTEG_N_ALG,
	} ipsec_integ_alg_t;

	typedef enum
	{
	IPSEC_PROTOCOL_AH = 0,
	IPSEC_PROTOCOL_ESP = 1
	} ipsec_protocol_t;

	#define IPSEC_KEY_MAX_LEN 128
	typedef struct ipsec_key_t_
	{
	u8 len;
	u8 data[IPSEC_KEY_MAX_LEN];
	} ipsec_key_t;

	/*
	* Enable extended sequence numbers
	* Enable Anti-replay
	* IPsec tunnel mode if non-zero, else transport mode
	* IPsec tunnel mode is IPv6 if non-zero,
	* else IPv4 tunnel only valid if is_tunnel is non-zero
	* enable UDP encapsulation for NAT traversal
	*/
	#define foreach_ipsec_sa_flags \
	_ (0, NONE, "none") \
	_ (1, USE_ESN, "esn") \
	_ (2, USE_ANTI_REPLAY, "anti-replay") \
	_ (4, IS_TUNNEL, "tunnel") \
	_ (8, IS_TUNNEL_V6, "tunnel-v6") \
	_ (16, UDP_ENCAP, "udp-encap") \
	_ (32, IS_PROTECT, "Protect") \
	_ (64, IS_INBOUND, "inbound") \
	_ (128, IS_AEAD, "aead") \

	typedef enum ipsec_sad_flags_t_
	{
	#define _(v, f, s) IPSEC_SA_FLAG_##f = v,
	foreach_ipsec_sa_flags
	#undef _
	} __clib_packed ipsec_sa_flags_t;

	STATIC_ASSERT (sizeof (ipsec_sa_flags_t) == 1, "IPSEC SA flags > 1 byte");

	typedef struct
	{
	CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);

	/* flags */
	ipsec_sa_flags_t flags;

	u8 crypto_iv_size;
	u8 crypto_block_size;
	u8 integ_icv_size;
	u32 encrypt_thread_index;
	u32 decrypt_thread_index;
	u32 spi;
	u32 seq;
	u32 seq_hi;
	u32 last_seq;
	u32 last_seq_hi;
	u64 replay_window;
	dpo_id_t dpo;

	vnet_crypto_key_index_t crypto_key_index;
	vnet_crypto_key_index_t integ_key_index;
	vnet_crypto_op_id_t crypto_enc_op_id:16;
	vnet_crypto_op_id_t crypto_dec_op_id:16;
	vnet_crypto_op_id_t integ_op_id:16;

	/* data accessed by dataplane code should be above this comment */
	CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

	union
	{
	ip4_header_t ip4_hdr;
	ip6_header_t ip6_hdr;
	};
	udp_header_t udp_hdr;

	fib_node_t node;
	u32 id;
	u32 stat_index;
	ipsec_protocol_t protocol;

	ipsec_crypto_alg_t crypto_alg;
	ipsec_key_t crypto_key;
	vnet_crypto_alg_t crypto_calg;

	ipsec_integ_alg_t integ_alg;
	ipsec_key_t integ_key;
	vnet_crypto_alg_t integ_calg;

	ip46_address_t tunnel_src_addr;
	ip46_address_t tunnel_dst_addr;

	fib_node_index_t fib_entry_index;
	u32 sibling;

	u32 tx_fib_index;

	/* Salt used in GCM modes - stored in network byte order */
	u32 salt;
	u64 gcm_iv_counter;
	} ipsec_sa_t;

	STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);

	#define _(a,v,s) \
	always_inline int \
	ipsec_sa_is_set_##v (const ipsec_sa_t *sa) { \
	return (sa->flags & IPSEC_SA_FLAG_##v); \
	}
	foreach_ipsec_sa_flags
	#undef _
	#define _(a,v,s) \
	always_inline int \
	ipsec_sa_set_##v (ipsec_sa_t *sa) { \
	return (sa->flags \|= IPSEC_SA_FLAG_##v); \
	}
	foreach_ipsec_sa_flags
	#undef _
	#define _(a,v,s) \
	always_inline int \
	ipsec_sa_unset_##v (ipsec_sa_t *sa) { \
	return (sa->flags &= ~IPSEC_SA_FLAG_##v); \
	}
	foreach_ipsec_sa_flags
	#undef _
	/**
	* @brief
	* SA packet & bytes counters
	*/
	extern vlib_combined_counter_main_t ipsec_sa_counters;

	extern void ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len);

	extern 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 * tunnel_src_addr,
	const ip46_address_t * tunnel_dst_addr,
	u32 * sa_index);
	extern index_t ipsec_sa_find_and_lock (u32 id);
	extern int ipsec_sa_unlock_id (u32 id);
	extern void ipsec_sa_unlock (index_t sai);
	extern void ipsec_sa_lock (index_t sai);
	extern void ipsec_sa_clear (index_t sai);
	extern void ipsec_sa_set_crypto_alg (ipsec_sa_t * sa,
	ipsec_crypto_alg_t crypto_alg);
	extern void ipsec_sa_set_integ_alg (ipsec_sa_t * sa,
	ipsec_integ_alg_t integ_alg);

	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);
	extern u8 format_ipsec_key (u8 s, va_list * args);
	extern uword unformat_ipsec_crypto_alg (unformat_input_t * input,
	va_list * args);
	extern uword unformat_ipsec_integ_alg (unformat_input_t * input,
	va_list * args);
	extern uword unformat_ipsec_key (unformat_input_t * input, va_list * args);

	/*
	* Anti Replay definitions
	*/

	#define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (64)
	#define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE-1)

	/*
	* sequence number less than the lower bound are outside of the window
	* From RFC4303 Appendix A:
	* Bl = Tl - W + 1
	*/
	#define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND(_tl) (_tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1)

	/*
	* Anti replay check.
	* inputs need to be in host byte order.
	*/
	always_inline int
	ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq)
	{
	u32 diff, tl, th;

	if ((sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
	return 0;

	if (!ipsec_sa_is_set_USE_ESN (sa))
	{
	if (PREDICT_TRUE (seq > sa->last_seq))
	return 0;

	diff = sa->last_seq - seq;

	if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff)
	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	else
	return 1;

	return 0;
	}

	tl = sa->last_seq;
	th = sa->last_seq_hi;
	diff = tl - seq;

	if (PREDICT_TRUE (tl >= (IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX)))
	{
	/*
	* the last sequence number VPP recieved is more than one
	* window size greater than zero.
	* Case A from RFC4303 Appendix A.
	*/
	if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
	{
	/*
	* the received sequence number is lower than the lower bound
	* of the window, this could mean either a replay packet or that
	* the high sequence number has wrapped. if it decrypts corrently
	* then it's the latter.
	*/
	sa->seq_hi = th + 1;
	return 0;
	}
	else
	{
	/*
	* the recieved sequence number greater than the low
	* end of the window.
	*/
	sa->seq_hi = th;
	if (seq <= tl)
	/*
	* The recieved seq number is within bounds of the window
	* check if it's a duplicate
	*/
	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	else
	/*
	* The received sequence number is greater than the window
	* upper bound. this packet will move the window along, assuming
	* it decrypts correctly.
	*/
	return 0;
	}
	}
	else
	{
	/*
	* the last sequence number VPP recieved is within one window
	* size of zero, i.e. 0 < TL < WINDOW_SIZE, the lower bound is thus a
	* large sequence number.
	* Note that the check below uses unsiged integer arthimetic, so the
	* RHS will be a larger number.
	* Case B from RFC4303 Appendix A.
	*/
	if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
	{
	/*
	* the sequence number is less than the lower bound.
	*/
	if (seq <= tl)
	{
	/*
	* the packet is within the window upper bound.
	* check for duplicates.
	*/
	sa->seq_hi = th;
	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	}
	else
	{
	/*
	* the packet is less the window lower bound or greater than
	* the higher bound, depending on how you look at it...
	* We're assuming, given that the last sequence number received,
	* TL < WINDOW_SIZE, that a largeer seq num is more likely to be
	* a packet that moves the window forward, than a packet that has
	* wrapped the high sequence again. If it were the latter then
	* we've lost close to 2^32 packets.
	*/
	sa->seq_hi = th;
	return 0;
	}
	}
	else
	{
	/*
	* the packet seq number is between the lower bound (a large nubmer)
	* and MAX_SEQ_NUM. This is in the window since the window upper bound
	* tl > 0.
	* However, since TL is the other side of 0 to the received
	* packet, the SA has moved on to a higher sequence number.
	*/
	sa->seq_hi = th - 1;
	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	}
	}

	return 0;
	}

	/*
	* Anti replay window advance
	* inputs need to be in host byte order.
	*/
	always_inline void
	ipsec_sa_anti_replay_advance (ipsec_sa_t * sa, u32 seq)
	{
	u32 pos;
	if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
	return;

	if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ESN))
	{
	int wrap = sa->seq_hi - sa->last_seq_hi;

	if (wrap == 0 && seq > sa->last_seq)
	{
	pos = seq - sa->last_seq;
	if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	sa->replay_window = ((sa->replay_window) << pos) \| 1;
	else
	sa->replay_window = 1;
	sa->last_seq = seq;
	}
	else if (wrap > 0)
	{
	pos = ~seq + sa->last_seq + 1;
	if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	sa->replay_window = ((sa->replay_window) << pos) \| 1;
	else
	sa->replay_window = 1;
	sa->last_seq = seq;
	sa->last_seq_hi = sa->seq_hi;
	}
	else if (wrap < 0)
	{
	pos = ~seq + sa->last_seq + 1;
	sa->replay_window \|= (1ULL << pos);
	}
	else
	{
	pos = sa->last_seq - seq;
	sa->replay_window \|= (1ULL << pos);
	}
	}
	else
	{
	if (seq > sa->last_seq)
	{
	pos = seq - sa->last_seq;
	if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	sa->replay_window = ((sa->replay_window) << pos) \| 1;
	else
	sa->replay_window = 1;
	sa->last_seq = seq;
	}
	else
	{
	pos = sa->last_seq - seq;
	sa->replay_window \|= (1ULL << pos);
	}
	}
	}


	/*
	* Makes choice for thread_id should be assigned.
	* if input ~0, gets random worker_id based on unix_time_now_nsec
	*/
	always_inline u32
	ipsec_sa_assign_thread (u32 thread_id)
	{
	return ((thread_id) ? thread_id
	: (unix_time_now_nsec () % vlib_num_workers ()) + 1);
	}

	#endif /* __IPSEC_SPD_SA_H__ */

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