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 <vppinfra/pcg.h>
 #include <vnet/crypto/crypto.h>
 #include <vnet/ip/ip.h>
 #include <vnet/fib/fib_node.h>
 #include <vnet/tunnel/tunnel.h>

 #define ESP_MAX_ICV_SIZE   (32)
 #define ESP_MAX_IV_SIZE	   (16)
 #define ESP_MAX_BLOCK_SIZE (16)

 #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")                                                \
   _ (12, CHACHA20_POLY1305, "chacha20-poly1305")

 typedef enum
 {
 #define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
   foreach_ipsec_crypto_alg
 #undef _
     IPSEC_CRYPTO_N_ALG,
 } __clib_packed 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 IPSEC_CRYPTO_ALG_IS_CTR(_alg)                                         \
   (((_alg == IPSEC_CRYPTO_ALG_AES_CTR_128) ||                                 \
     (_alg == IPSEC_CRYPTO_ALG_AES_CTR_192) ||                                 \
     (_alg == IPSEC_CRYPTO_ALG_AES_CTR_256)))

 #define IPSEC_CRYPTO_ALG_CTR_AEAD_OTHERS(_alg)                                \
   (_alg == IPSEC_CRYPTO_ALG_CHACHA20_POLY1305)

 #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,
 } __clib_packed ipsec_integ_alg_t;

 typedef enum
 {
   IPSEC_PROTOCOL_AH = 0,
   IPSEC_PROTOCOL_ESP = 1
 } __clib_packed 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")                                                    \
   _ (256, IS_CTR, "ctr")                                                      \
   _ (512, IS_ASYNC, "async")                                                  \
   _ (1024, NO_ALGO_NO_DROP, "no-algo-no-drop")

 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) == 2, "IPSEC SA flags != 2 byte");

 #define foreach_ipsec_sa_err                                                  \
   _ (0, LOST, lost, "packets lost")                                           \
   _ (1, HANDOFF, handoff, "hand-off")                                         \
   _ (2, INTEG_ERROR, integ_error, "Integrity check failed")                   \
   _ (3, DECRYPTION_FAILED, decryption_failed, "Decryption failed")            \
   _ (4, CRYPTO_ENGINE_ERROR, crypto_engine_error,                             \
      "crypto engine error (dropped)")                                         \
   _ (5, REPLAY, replay, "SA replayed packet")                                 \
   _ (6, RUNT, runt, "undersized packet")                                      \
   _ (7, NO_BUFFERS, no_buffers, "no buffers (dropped)")                       \
   _ (8, OVERSIZED_HEADER, oversized_header,                                   \
      "buffer with oversized header (dropped)")                                \
   _ (9, NO_TAIL_SPACE, no_tail_space,                                         \
      "no enough buffer tail space (dropped)")                                 \
   _ (10, TUN_NO_PROTO, tun_no_proto, "no tunnel protocol")                    \
   _ (11, UNSUP_PAYLOAD, unsup_payload, "unsupported payload")                 \
   _ (12, SEQ_CYCLED, seq_cycled, "sequence number cycled (dropped)")          \
   _ (13, CRYPTO_QUEUE_FULL, crypto_queue_full, "crypto queue full (dropped)") \
   _ (14, NO_ENCRYPTION, no_encryption, "no Encrypting SA (dropped)")          \
   _ (15, DROP_FRAGMENTS, drop_fragments, "IP fragments drop")

 typedef enum
 {
 #define _(v, f, s, d) IPSEC_SA_ERROR_##f = v,
   foreach_ipsec_sa_err
 #undef _
     IPSEC_SA_N_ERRORS,
 } __clib_packed ipsec_sa_err_t;

 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);

   clib_pcg64i_random_t iv_prng;

   u64 replay_window;
   dpo_id_t dpo;

   vnet_crypto_key_index_t crypto_key_index;
   vnet_crypto_key_index_t integ_key_index;

   u32 spi;
   u32 seq;
   u32 seq_hi;

   u16 crypto_enc_op_id;
   u16 crypto_dec_op_id;
   u16 integ_op_id;
   ipsec_sa_flags_t flags;
   u16 thread_index;

   u16 integ_icv_size : 6;
   u16 crypto_iv_size : 5;
   u16 esp_block_align : 5;

   CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

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

   /* Salt used in CTR modes (incl. GCM) - stored in network byte order */
   u32 salt;

   ipsec_protocol_t protocol;
   tunnel_encap_decap_flags_t tunnel_flags;
   u8 __pad[2];

   /* data accessed by dataplane code should be above this comment */
     CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);

   /* Elements with u64 size multiples */
   tunnel_t tunnel;
   fib_node_t node;

   /* elements with u32 size */
   u32 id;
   u32 stat_index;
   vnet_crypto_alg_t integ_calg;
   vnet_crypto_alg_t crypto_calg;
   u32 crypto_sync_key_index;
   u32 integ_sync_key_index;
   u32 crypto_async_key_index;

   /* elements with u16 size */
   u16 crypto_sync_enc_op_id;
   u16 crypto_sync_dec_op_id;
   u16 integ_sync_op_id;
   u16 crypto_async_enc_op_id;
   u16 crypto_async_dec_op_id;

   /* else u8 packed */
   ipsec_crypto_alg_t crypto_alg;
   ipsec_integ_alg_t integ_alg;

   ipsec_key_t integ_key;
   ipsec_key_t crypto_key;
 } ipsec_sa_t;

 STATIC_ASSERT (VNET_CRYPTO_N_OP_IDS < (1 << 16), "crypto ops overflow");
 STATIC_ASSERT (ESP_MAX_ICV_SIZE < (1 << 6), "integer icv overflow");
 STATIC_ASSERT (ESP_MAX_IV_SIZE < (1 << 5), "esp iv overflow");
 STATIC_ASSERT (ESP_MAX_BLOCK_SIZE < (1 << 5), "esp alignment overflow");
 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);
 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline2, 2 * CLIB_CACHE_LINE_BYTES);

 /**
  * Pool of IPSec SAs
  */
 extern ipsec_sa_t *ipsec_sa_pool;

 /*
  * Ensure that the IPsec data does not overlap with the IP data in
  * the buffer meta data
  */
 STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ipsec.sad_index) ==
 		 STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_protocol),
 	       "IPSec data is overlapping with IP data");

 #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 vlib_simple_counter_main_t ipsec_sa_err_counters[IPSEC_SA_N_ERRORS];

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

 extern int ipsec_sa_update (u32 id, u16 src_port, u16 dst_port,
 			    const tunnel_t *tun, bool is_tun);
 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 salt, u16 src_port,
 		       u16 dst_port, const tunnel_t *tun, u32 *sa_out_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);
 extern void ipsec_sa_set_async_mode (ipsec_sa_t *sa, int is_enabled);

 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_replay_window (u8 *s, va_list *args);
 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);

 #define IPSEC_UDP_PORT_NONE ((u16)~0)

 /*
  * 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)

 always_inline int
 ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq)
 {
   if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) &&
       sa->replay_window & (1ULL << (sa->seq - seq)))
     return 1;
   else
     return 0;
 }

 /*
  * Anti replay check.
  *  inputs need to be in host byte order.
  *
  * The function runs in two contexts. pre and post decrypt.
  * Pre-decrypt it:
  *  1 - determines if a packet is a replay - a simple check in the window
  *  2 - returns the hi-seq number that should be used to decrypt.
  * post-decrypt:
  *  Checks whether the packet is a replay or falls out of window
  *
  * This funcion should be called even without anti-replay enabled to ensure
  * the high sequence number is set.
  */
 always_inline int
 ipsec_sa_anti_replay_and_sn_advance (const ipsec_sa_t *sa, u32 seq,
 				     u32 hi_seq_used, bool post_decrypt,
 				     u32 *hi_seq_req)
 {
   ASSERT ((post_decrypt == false) == (hi_seq_req != 0));

   if (!ipsec_sa_is_set_USE_ESN (sa))
     {
       if (hi_seq_req)
 	/* no ESN, therefore the hi-seq is always 0 */
 	*hi_seq_req = 0;

       if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
 	return 0;

       if (PREDICT_TRUE (seq > sa->seq))
 	return 0;

       u32 diff = sa->seq - seq;

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

       return 0;
     }

   if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
     {
       /* there's no AR configured for this SA, but in order
        * to know whether a packet has wrapped the hi ESN we need
        * to know whether it is out of window. if we use the default
        * lower bound then we are effectively forcing AR because
        * out of window packets will get the increased hi seq number
        * and will thus fail to decrypt. IOW we need a window to know
        * if the SN has wrapped, but we don't want a window to check for
        * anti replay. to resolve the contradiction we use a huge window.
        * if the packet is not within 2^30 of the current SN, we'll consider
        * it a wrap.
        */
       if (hi_seq_req)
 	{
 	  if (seq >= sa->seq)
 	    /* The packet's sequence number is larger that the SA's.
 	     * that can't be a warp - unless we lost more than
 	     * 2^32 packets ... how could we know? */
 	    *hi_seq_req = sa->seq_hi;
 	  else
 	    {
 	      /* The packet's SN is less than the SAs, so either the SN has
 	       * wrapped or the SN is just old. */
 	      if (sa->seq - seq > (1 << 30))
 		/* It's really really really old => it wrapped */
 		*hi_seq_req = sa->seq_hi + 1;
 	      else
 		*hi_seq_req = sa->seq_hi;
 	    }
 	}
       /*
        * else
        *   this is post-decrpyt and since it decrypted we accept it
        */
       return 0;
     }
   if (PREDICT_TRUE (sa->seq >= (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 (sa->seq))
 	{
 	  /*
 	   * 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.
 	   */
 	  if (post_decrypt)
 	    {
 	      if (hi_seq_used == sa->seq_hi)
 		/* the high sequence number used to succesfully decrypt this
 		 * packet is the same as the last-sequnence number of the SA.
 		 * that means this packet did not cause a wrap.
 		 * this packet is thus out of window and should be dropped */
 		return 1;
 	      else
 		/* The packet decrypted with a different high sequence number
 		 * to the SA, that means it is the wrap packet and should be
 		 * accepted */
 		return 0;
 	    }
 	  else
 	    {
 	      /* pre-decrypt it might be the might that casues a wrap, we
 	       * need to decrpyt to find out */
 	      if (hi_seq_req)
 		*hi_seq_req = sa->seq_hi + 1;
 	      return 0;
 	    }
 	}
       else
 	{
 	  /*
 	   * the recieved sequence number greater than the low
 	   * end of the window.
 	   */
 	  if (hi_seq_req)
 	    *hi_seq_req = sa->seq_hi;
 	  if (seq <= sa->seq)
 	    /*
 	     * The recieved seq number is within bounds of the window
 	     * check if it's a duplicate
 	     */
 	    return (ipsec_sa_anti_replay_check (sa, seq));
 	  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 (sa->seq))
 	{
 	  /*
 	   * the sequence number is less than the lower bound.
 	   */
 	  if (seq <= sa->seq)
 	    {
 	      /*
 	       * the packet is within the window upper bound.
 	       * check for duplicates.
 	       */
 	      if (hi_seq_req)
 		*hi_seq_req = sa->seq_hi;
 	      return (ipsec_sa_anti_replay_check (sa, seq));
 	    }
 	  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.
 	       */
 	      if (hi_seq_req)
 		*hi_seq_req = sa->seq_hi;
 	      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.
 	   */
 	  if (hi_seq_req)
 	    *hi_seq_req = sa->seq_hi - 1;
 	  return (ipsec_sa_anti_replay_check (sa, seq));
 	}
     }

   /* unhandled case */
   ASSERT (0);
   return 0;
 }

 always_inline u32
 ipsec_sa_anti_replay_window_shift (ipsec_sa_t *sa, u32 inc)
 {
   u32 n_lost = 0;

   if (inc < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
     {
       if (sa->seq > IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
 	{
 	  /*
 	   * count how many holes there are in the portion
 	   * of the window that we will right shift of the end
 	   * as a result of this increments
 	   */
 	  u64 mask = (((u64) 1 << inc) - 1) << (BITS (u64) - inc);
 	  u64 old = sa->replay_window & mask;
 	  /* the number of packets we saw in this section of the window */
 	  u64 seen = count_set_bits (old);

 	  /*
 	   * the number we missed is the size of the window section
 	   * minus the number we saw.
 	   */
 	  n_lost = inc - seen;
 	}
       sa->replay_window = ((sa->replay_window) << inc) | 1;
     }
   else
     {
       /* holes in the replay window are lost packets */
       n_lost = BITS (u64) - count_set_bits (sa->replay_window);

       /* any sequence numbers that now fall outside the window
        * are forever lost */
       n_lost += inc - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE;

       sa->replay_window = 1;
     }

   return (n_lost);
 }

 /*
  * Anti replay window advance
  *  inputs need to be in host byte order.
  * This function both advances the anti-replay window and the sequence number
  * We always need to move on the SN but the window updates are only needed
  * if AR is on.
  * However, updating the window is trivial, so we do it anyway to save
  * the branch cost.
  */
 always_inline u64
 ipsec_sa_anti_replay_advance (ipsec_sa_t *sa, u32 thread_index, u32 seq,
 			      u32 hi_seq)
 {
   u64 n_lost = 0;
   u32 pos;

   if (ipsec_sa_is_set_USE_ESN (sa))
     {
       int wrap = hi_seq - sa->seq_hi;

       if (wrap == 0 && seq > sa->seq)
 	{
 	  pos = seq - sa->seq;
 	  n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
 	  sa->seq = seq;
 	}
       else if (wrap > 0)
 	{
 	  pos = ~seq + sa->seq + 1;
 	  n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
 	  sa->seq = seq;
 	  sa->seq_hi = hi_seq;
 	}
       else if (wrap < 0)
 	{
 	  pos = ~seq + sa->seq + 1;
 	  sa->replay_window |= (1ULL << pos);
 	}
       else
 	{
 	  pos = sa->seq - seq;
 	  sa->replay_window |= (1ULL << pos);
 	}
     }
   else
     {
       if (seq > sa->seq)
 	{
 	  pos = seq - sa->seq;
 	  n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
 	  sa->seq = seq;
 	}
       else
 	{
 	  pos = sa->seq - seq;
 	  sa->replay_window |= (1ULL << pos);
 	}
     }

   return n_lost;
 }


 /*
  * Makes choice for thread_id should be assigned.
  *  if input ~0, gets random worker_id based on unix_time_now_nsec
 */
 always_inline u16
 ipsec_sa_assign_thread (u16 thread_id)
 {
   return ((thread_id) ? thread_id
 	  : (unix_time_now_nsec () % vlib_num_workers ()) + 1);
 }

 always_inline ipsec_sa_t *
 ipsec_sa_get (u32 sa_index)
 {
   return (pool_elt_at_index (ipsec_sa_pool, sa_index));
 }

 #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 <vppinfra/pcg.h>
	#include <vnet/crypto/crypto.h>
	#include <vnet/ip/ip.h>
	#include <vnet/fib/fib_node.h>
	#include <vnet/tunnel/tunnel.h>

	#define ESP_MAX_ICV_SIZE (32)
	#define ESP_MAX_IV_SIZE (16)
	#define ESP_MAX_BLOCK_SIZE (16)

	#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") \
	_ (12, CHACHA20_POLY1305, "chacha20-poly1305")

	typedef enum
	{
	#define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
	foreach_ipsec_crypto_alg
	#undef _
	IPSEC_CRYPTO_N_ALG,
	} __clib_packed 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 IPSEC_CRYPTO_ALG_IS_CTR(_alg) \
	(((_alg == IPSEC_CRYPTO_ALG_AES_CTR_128) \|\| \
	(_alg == IPSEC_CRYPTO_ALG_AES_CTR_192) \|\| \
	(_alg == IPSEC_CRYPTO_ALG_AES_CTR_256)))

	#define IPSEC_CRYPTO_ALG_CTR_AEAD_OTHERS(_alg) \
	(_alg == IPSEC_CRYPTO_ALG_CHACHA20_POLY1305)

	#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,
	} __clib_packed ipsec_integ_alg_t;

	typedef enum
	{
	IPSEC_PROTOCOL_AH = 0,
	IPSEC_PROTOCOL_ESP = 1
	} __clib_packed 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") \
	_ (256, IS_CTR, "ctr") \
	_ (512, IS_ASYNC, "async") \
	_ (1024, NO_ALGO_NO_DROP, "no-algo-no-drop")

	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) == 2, "IPSEC SA flags != 2 byte");

	#define foreach_ipsec_sa_err \
	_ (0, LOST, lost, "packets lost") \
	_ (1, HANDOFF, handoff, "hand-off") \
	_ (2, INTEG_ERROR, integ_error, "Integrity check failed") \
	_ (3, DECRYPTION_FAILED, decryption_failed, "Decryption failed") \
	_ (4, CRYPTO_ENGINE_ERROR, crypto_engine_error, \
	"crypto engine error (dropped)") \
	_ (5, REPLAY, replay, "SA replayed packet") \
	_ (6, RUNT, runt, "undersized packet") \
	_ (7, NO_BUFFERS, no_buffers, "no buffers (dropped)") \
	_ (8, OVERSIZED_HEADER, oversized_header, \
	"buffer with oversized header (dropped)") \
	_ (9, NO_TAIL_SPACE, no_tail_space, \
	"no enough buffer tail space (dropped)") \
	_ (10, TUN_NO_PROTO, tun_no_proto, "no tunnel protocol") \
	_ (11, UNSUP_PAYLOAD, unsup_payload, "unsupported payload") \
	_ (12, SEQ_CYCLED, seq_cycled, "sequence number cycled (dropped)") \
	_ (13, CRYPTO_QUEUE_FULL, crypto_queue_full, "crypto queue full (dropped)") \
	_ (14, NO_ENCRYPTION, no_encryption, "no Encrypting SA (dropped)") \
	_ (15, DROP_FRAGMENTS, drop_fragments, "IP fragments drop")

	typedef enum
	{
	#define _(v, f, s, d) IPSEC_SA_ERROR_##f = v,
	foreach_ipsec_sa_err
	#undef _
	IPSEC_SA_N_ERRORS,
	} __clib_packed ipsec_sa_err_t;

	typedef struct
	{
	CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);

	clib_pcg64i_random_t iv_prng;

	u64 replay_window;
	dpo_id_t dpo;

	vnet_crypto_key_index_t crypto_key_index;
	vnet_crypto_key_index_t integ_key_index;

	u32 spi;
	u32 seq;
	u32 seq_hi;

	u16 crypto_enc_op_id;
	u16 crypto_dec_op_id;
	u16 integ_op_id;
	ipsec_sa_flags_t flags;
	u16 thread_index;

	u16 integ_icv_size : 6;
	u16 crypto_iv_size : 5;
	u16 esp_block_align : 5;

	CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

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

	/* Salt used in CTR modes (incl. GCM) - stored in network byte order */
	u32 salt;

	ipsec_protocol_t protocol;
	tunnel_encap_decap_flags_t tunnel_flags;
	u8 __pad[2];

	/* data accessed by dataplane code should be above this comment */
	CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);

	/* Elements with u64 size multiples */
	tunnel_t tunnel;
	fib_node_t node;

	/* elements with u32 size */
	u32 id;
	u32 stat_index;
	vnet_crypto_alg_t integ_calg;
	vnet_crypto_alg_t crypto_calg;
	u32 crypto_sync_key_index;
	u32 integ_sync_key_index;
	u32 crypto_async_key_index;

	/* elements with u16 size */
	u16 crypto_sync_enc_op_id;
	u16 crypto_sync_dec_op_id;
	u16 integ_sync_op_id;
	u16 crypto_async_enc_op_id;
	u16 crypto_async_dec_op_id;

	/* else u8 packed */
	ipsec_crypto_alg_t crypto_alg;
	ipsec_integ_alg_t integ_alg;

	ipsec_key_t integ_key;
	ipsec_key_t crypto_key;
	} ipsec_sa_t;

	STATIC_ASSERT (VNET_CRYPTO_N_OP_IDS < (1 << 16), "crypto ops overflow");
	STATIC_ASSERT (ESP_MAX_ICV_SIZE < (1 << 6), "integer icv overflow");
	STATIC_ASSERT (ESP_MAX_IV_SIZE < (1 << 5), "esp iv overflow");
	STATIC_ASSERT (ESP_MAX_BLOCK_SIZE < (1 << 5), "esp alignment overflow");
	STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);
	STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline2, 2 * CLIB_CACHE_LINE_BYTES);

	/**
	* Pool of IPSec SAs
	*/
	extern ipsec_sa_t *ipsec_sa_pool;

	/*
	* Ensure that the IPsec data does not overlap with the IP data in
	* the buffer meta data
	*/
	STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ipsec.sad_index) ==
	STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_protocol),
	"IPSec data is overlapping with IP data");

	#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 vlib_simple_counter_main_t ipsec_sa_err_counters[IPSEC_SA_N_ERRORS];

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

	extern int ipsec_sa_update (u32 id, u16 src_port, u16 dst_port,
	const tunnel_t *tun, bool is_tun);
	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 salt, u16 src_port,
	u16 dst_port, const tunnel_t tun, u32 sa_out_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);
	extern void ipsec_sa_set_async_mode (ipsec_sa_t *sa, int is_enabled);

	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_replay_window (u8 s, va_list *args);
	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);

	#define IPSEC_UDP_PORT_NONE ((u16)~0)

	/*
	* 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)

	always_inline int
	ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq)
	{
	if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) &&
	sa->replay_window & (1ULL << (sa->seq - seq)))
	return 1;
	else
	return 0;
	}

	/*
	* Anti replay check.
	* inputs need to be in host byte order.
	*
	* The function runs in two contexts. pre and post decrypt.
	* Pre-decrypt it:
	* 1 - determines if a packet is a replay - a simple check in the window
	* 2 - returns the hi-seq number that should be used to decrypt.
	* post-decrypt:
	* Checks whether the packet is a replay or falls out of window
	*
	* This funcion should be called even without anti-replay enabled to ensure
	* the high sequence number is set.
	*/
	always_inline int
	ipsec_sa_anti_replay_and_sn_advance (const ipsec_sa_t *sa, u32 seq,
	u32 hi_seq_used, bool post_decrypt,
	u32 *hi_seq_req)
	{
	ASSERT ((post_decrypt == false) == (hi_seq_req != 0));

	if (!ipsec_sa_is_set_USE_ESN (sa))
	{
	if (hi_seq_req)
	/* no ESN, therefore the hi-seq is always 0 */
	*hi_seq_req = 0;

	if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
	return 0;

	if (PREDICT_TRUE (seq > sa->seq))
	return 0;

	u32 diff = sa->seq - seq;

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

	return 0;
	}

	if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
	{
	/* there's no AR configured for this SA, but in order
	* to know whether a packet has wrapped the hi ESN we need
	* to know whether it is out of window. if we use the default
	* lower bound then we are effectively forcing AR because
	* out of window packets will get the increased hi seq number
	* and will thus fail to decrypt. IOW we need a window to know
	* if the SN has wrapped, but we don't want a window to check for
	* anti replay. to resolve the contradiction we use a huge window.
	* if the packet is not within 2^30 of the current SN, we'll consider
	* it a wrap.
	*/
	if (hi_seq_req)
	{
	if (seq >= sa->seq)
	/* The packet's sequence number is larger that the SA's.
	* that can't be a warp - unless we lost more than
	* 2^32 packets ... how could we know? */
	*hi_seq_req = sa->seq_hi;
	else
	{
	/* The packet's SN is less than the SAs, so either the SN has
	* wrapped or the SN is just old. */
	if (sa->seq - seq > (1 << 30))
	/* It's really really really old => it wrapped */
	*hi_seq_req = sa->seq_hi + 1;
	else
	*hi_seq_req = sa->seq_hi;
	}
	}
	/*
	* else
	* this is post-decrpyt and since it decrypted we accept it
	*/
	return 0;
	}
	if (PREDICT_TRUE (sa->seq >= (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 (sa->seq))
	{
	/*
	* 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.
	*/
	if (post_decrypt)
	{
	if (hi_seq_used == sa->seq_hi)
	/* the high sequence number used to succesfully decrypt this
	* packet is the same as the last-sequnence number of the SA.
	* that means this packet did not cause a wrap.
	* this packet is thus out of window and should be dropped */
	return 1;
	else
	/* The packet decrypted with a different high sequence number
	* to the SA, that means it is the wrap packet and should be
	* accepted */
	return 0;
	}
	else
	{
	/* pre-decrypt it might be the might that casues a wrap, we
	* need to decrpyt to find out */
	if (hi_seq_req)
	*hi_seq_req = sa->seq_hi + 1;
	return 0;
	}
	}
	else
	{
	/*
	* the recieved sequence number greater than the low
	* end of the window.
	*/
	if (hi_seq_req)
	*hi_seq_req = sa->seq_hi;
	if (seq <= sa->seq)
	/*
	* The recieved seq number is within bounds of the window
	* check if it's a duplicate
	*/
	return (ipsec_sa_anti_replay_check (sa, seq));
	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 (sa->seq))
	{
	/*
	* the sequence number is less than the lower bound.
	*/
	if (seq <= sa->seq)
	{
	/*
	* the packet is within the window upper bound.
	* check for duplicates.
	*/
	if (hi_seq_req)
	*hi_seq_req = sa->seq_hi;
	return (ipsec_sa_anti_replay_check (sa, seq));
	}
	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.
	*/
	if (hi_seq_req)
	*hi_seq_req = sa->seq_hi;
	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.
	*/
	if (hi_seq_req)
	*hi_seq_req = sa->seq_hi - 1;
	return (ipsec_sa_anti_replay_check (sa, seq));
	}
	}

	/* unhandled case */
	ASSERT (0);
	return 0;
	}

	always_inline u32
	ipsec_sa_anti_replay_window_shift (ipsec_sa_t *sa, u32 inc)
	{
	u32 n_lost = 0;

	if (inc < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	{
	if (sa->seq > IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	{
	/*
	* count how many holes there are in the portion
	* of the window that we will right shift of the end
	* as a result of this increments
	*/
	u64 mask = (((u64) 1 << inc) - 1) << (BITS (u64) - inc);
	u64 old = sa->replay_window & mask;
	/* the number of packets we saw in this section of the window */
	u64 seen = count_set_bits (old);

	/*
	* the number we missed is the size of the window section
	* minus the number we saw.
	*/
	n_lost = inc - seen;
	}
	sa->replay_window = ((sa->replay_window) << inc) \| 1;
	}
	else
	{
	/* holes in the replay window are lost packets */
	n_lost = BITS (u64) - count_set_bits (sa->replay_window);

	/* any sequence numbers that now fall outside the window
	* are forever lost */
	n_lost += inc - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE;

	sa->replay_window = 1;
	}

	return (n_lost);
	}

	/*
	* Anti replay window advance
	* inputs need to be in host byte order.
	* This function both advances the anti-replay window and the sequence number
	* We always need to move on the SN but the window updates are only needed
	* if AR is on.
	* However, updating the window is trivial, so we do it anyway to save
	* the branch cost.
	*/
	always_inline u64
	ipsec_sa_anti_replay_advance (ipsec_sa_t *sa, u32 thread_index, u32 seq,
	u32 hi_seq)
	{
	u64 n_lost = 0;
	u32 pos;

	if (ipsec_sa_is_set_USE_ESN (sa))
	{
	int wrap = hi_seq - sa->seq_hi;

	if (wrap == 0 && seq > sa->seq)
	{
	pos = seq - sa->seq;
	n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
	sa->seq = seq;
	}
	else if (wrap > 0)
	{
	pos = ~seq + sa->seq + 1;
	n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
	sa->seq = seq;
	sa->seq_hi = hi_seq;
	}
	else if (wrap < 0)
	{
	pos = ~seq + sa->seq + 1;
	sa->replay_window \|= (1ULL << pos);
	}
	else
	{
	pos = sa->seq - seq;
	sa->replay_window \|= (1ULL << pos);
	}
	}
	else
	{
	if (seq > sa->seq)
	{
	pos = seq - sa->seq;
	n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
	sa->seq = seq;
	}
	else
	{
	pos = sa->seq - seq;
	sa->replay_window \|= (1ULL << pos);
	}
	}

	return n_lost;
	}


	/*
	* Makes choice for thread_id should be assigned.
	* if input ~0, gets random worker_id based on unix_time_now_nsec
	*/
	always_inline u16
	ipsec_sa_assign_thread (u16 thread_id)
	{
	return ((thread_id) ? thread_id
	: (unix_time_now_nsec () % vlib_num_workers ()) + 1);
	}

	always_inline ipsec_sa_t *
	ipsec_sa_get (u32 sa_index)
	{
	return (pool_elt_at_index (ipsec_sa_pool, sa_index));
	}

	#endif /* __IPSEC_SPD_SA_H__ */

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