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gerrit.nordix.org / fdio / vpp / 71c32a898941e32b5d4f865b50fbe775560c582d / . / src / vnet / ipsec / ipsec_sa.h
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/*
* 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") \
_ (13, AES_NULL_GMAC_128, "aes-null-gmac-128") \
_ (14, AES_NULL_GMAC_192, "aes-null-gmac-192") \
_ (15, AES_NULL_GMAC_256, "aes-null-gmac-256")
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_NULL_GMAC(_alg) \
((_alg == IPSEC_CRYPTO_ALG_AES_NULL_GMAC_128) || \
(_alg == IPSEC_CRYPTO_ALG_AES_NULL_GMAC_192) || \
(_alg == IPSEC_CRYPTO_ALG_AES_NULL_GMAC_256))
#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") \
_ (2048, IS_NULL_GMAC, "null-gmac") \
_ (4096, ANTI_REPLAY_HUGE, "anti-replay-huge")
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;
union
{
u64 replay_window;
clib_bitmap_t *replay_window_huge;
};
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 bool 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 void ipsec_sa_set_##v (ipsec_sa_t *sa) \
{ \
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,
u32 anti_replay_window_size, const tunnel_t *tun, u32 *sa_out_index);
extern int ipsec_sa_bind (u32 id, u32 worker, bool bind);
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(_sa) \
(u32) (PREDICT_FALSE (ipsec_sa_is_set_ANTI_REPLAY_HUGE (_sa)) ? \
clib_bitmap_bytes (_sa->replay_window_huge) * 8 : \
BITS (_sa->replay_window))
#define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN(_sa, _is_huge) \
(u32) (_is_huge ? clib_bitmap_bytes (_sa->replay_window_huge) * 8 : \
BITS (_sa->replay_window))
#define IPSEC_SA_ANTI_REPLAY_WINDOW_N_SEEN(_sa) \
(u64) (PREDICT_FALSE (ipsec_sa_is_set_ANTI_REPLAY_HUGE (_sa)) ? \
clib_bitmap_count_set_bits (_sa->replay_window_huge) : \
count_set_bits (_sa->replay_window))
#define IPSEC_SA_ANTI_REPLAY_WINDOW_N_SEEN_KNOWN_WIN(_sa, _is_huge) \
(u64) (_is_huge ? clib_bitmap_count_set_bits (_sa->replay_window_huge) : \
count_set_bits (_sa->replay_window))
#define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX(_sa) \
(u32) (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (_sa) - 1)
#define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX_KNOWN_WIN(_sa, _is_huge) \
(u32) (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (_sa, _is_huge) - 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(_sa) \
(u32) (_sa->seq - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (_sa) + 1)
#define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND_KNOWN_WIN(_sa, _is_huge) \
(u32) (_sa->seq - \
IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (_sa, _is_huge) + 1)
always_inline u64
ipsec_sa_anti_replay_get_64b_window (const ipsec_sa_t *sa)
{
if (!ipsec_sa_is_set_ANTI_REPLAY_HUGE (sa))
return sa->replay_window;
u64 w;
u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (sa);
u32 tl_win_index = sa->seq & (window_size - 1);
if (PREDICT_TRUE (tl_win_index >= 63))
return clib_bitmap_get_multiple (sa->replay_window_huge, tl_win_index - 63,
64);
w = clib_bitmap_get_multiple_no_check (sa->replay_window_huge, 0,
tl_win_index + 1)
<< (63 - tl_win_index);
w |= clib_bitmap_get_multiple_no_check (sa->replay_window_huge,
window_size - 63 + tl_win_index,
63 - tl_win_index);
return w;
}
always_inline int
ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq, bool ar_huge)
{
u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge);
/* we assume that the packet is in the window.
* if the packet falls left (sa->seq - seq >= window size),
* the result is wrong */
if (ar_huge)
return clib_bitmap_get (sa->replay_window_huge, seq & (window_size - 1));
else
return (sa->replay_window >> (window_size + seq - sa->seq - 1)) & 1;
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, bool ar_huge)
{
ASSERT ((post_decrypt == false) == (hi_seq_req != 0));
u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge);
u32 window_lower_bound =
IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND_KNOWN_WIN (sa, ar_huge);
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;
/* does the packet fall out on the left of the window */
if (sa->seq >= seq + window_size)
return 1;
return ipsec_sa_anti_replay_check (sa, seq, ar_huge);
}
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 >= window_size - 1))
{
/*
* the last sequence number VPP received is more than one
* window size greater than zero.
* Case A from RFC4303 Appendix A.
*/
if (seq < window_lower_bound)
{
/*
* 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-sequence 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 packet that causes a wrap, we
* need to decrypt it to find out */
if (hi_seq_req)
*hi_seq_req = sa->seq_hi + 1;
return 0;
}
}
else
{
/*
* the received 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 received seq number is within bounds of the window
* check if it's a duplicate
*/
return ipsec_sa_anti_replay_check (sa, seq, ar_huge);
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 received 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 unsigned integer arithmetic, so the
* RHS will be a larger number.
* Case B from RFC4303 Appendix A.
*/
if (seq < window_lower_bound)
{
/*
* 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, ar_huge);
}
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 larger 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 number)
* 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, ar_huge);
}
}
/* unhandled case */
ASSERT (0);
return 0;
}
always_inline u32
ipsec_sa_anti_replay_window_shift (ipsec_sa_t *sa, u32 inc, bool ar_huge)
{
u32 n_lost = 0;
u32 seen = 0;
u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge);
if (inc < window_size)
{
if (ar_huge)
{
/* the number of packets we saw in this section of the window */
clib_bitmap_t *window = sa->replay_window_huge;
u32 window_lower_bound = (sa->seq + 1) & (window_size - 1);
u32 window_next_lower_bound =
(window_lower_bound + inc) & (window_size - 1);
uword i_block, i_word_start, i_word_end, full_words;
uword n_blocks = window_size >> log2_uword_bits;
uword mask;
i_block = window_lower_bound >> log2_uword_bits;
i_word_start = window_lower_bound & (uword_bits - 1);
i_word_end = window_next_lower_bound & (uword_bits - 1);
/* We stay in the same word */
if (i_word_start + inc <= uword_bits)
{
mask = pow2_mask (inc) << i_word_start;
seen += count_set_bits (window[i_block] & mask);
window[i_block] &= ~mask;
}
else
{
full_words = (inc + i_word_start - uword_bits - i_word_end) >>
log2_uword_bits;
/* count set bits in the first word */
mask = (uword) ~0 << i_word_start;
seen += count_set_bits (window[i_block] & mask);
window[i_block] &= ~mask;
i_block = (i_block + 1) & (n_blocks - 1);
/* count set bits in the next full words */
/* even if the last word need to be fully counted, we treat it
* apart */
while (full_words >= 8)
{
if (full_words >= 16)
{
/* prefect the next 8 blocks (64 bytes) */
clib_prefetch_store (
&window[(i_block + 8) & (n_blocks - 1)]);
}
seen += count_set_bits (window[i_block]);
seen +=
count_set_bits (window[(i_block + 1) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 2) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 3) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 4) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 5) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 6) & (n_blocks - 1)]);
seen +=
count_set_bits (window[(i_block + 7) & (n_blocks - 1)]);
window[i_block] = 0;
window[(i_block + 1) & (n_blocks - 1)] = 0;
window[(i_block + 2) & (n_blocks - 1)] = 0;
window[(i_block + 3) & (n_blocks - 1)] = 0;
window[(i_block + 4) & (n_blocks - 1)] = 0;
window[(i_block + 5) & (n_blocks - 1)] = 0;
window[(i_block + 6) & (n_blocks - 1)] = 0;
window[(i_block + 7) & (n_blocks - 1)] = 0;
i_block = (i_block + 8) & (n_blocks - 1);
full_words -= 8;
}
while (full_words > 0)
{
// last word is treated after the loop
seen += count_set_bits (window[i_block]);
window[i_block] = 0;
i_block = (i_block + 1) & (n_blocks - 1);
full_words--;
}
/* the last word */
mask = pow2_mask (i_word_end);
seen += count_set_bits (window[i_block] & mask);
window[i_block] &= ~mask;
}
clib_bitmap_set_no_check (window,
(sa->seq + inc) & (window_size - 1), 1);
}
else
{
/*
* 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 old = sa->replay_window & pow2_mask (inc);
/* the number of packets we saw in this section of the window */
seen = count_set_bits (old);
sa->replay_window =
((sa->replay_window) >> inc) | (1ULL << (window_size - 1));
}
/*
* the number we missed is the size of the window section
* minus the number we saw.
*/
n_lost = inc - seen;
}
else
{
/* holes in the replay window are lost packets */
n_lost = window_size -
IPSEC_SA_ANTI_REPLAY_WINDOW_N_SEEN_KNOWN_WIN (sa, ar_huge);
/* any sequence numbers that now fall outside the window
* are forever lost */
n_lost += inc - window_size;
if (PREDICT_FALSE (ar_huge))
{
clib_bitmap_zero (sa->replay_window_huge);
clib_bitmap_set_no_check (sa->replay_window_huge,
(sa->seq + inc) & (window_size - 1), 1);
}
else
{
sa->replay_window = 1ULL << (window_size - 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, bool ar_huge)
{
u64 n_lost = 0;
u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge);
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, ar_huge);
sa->seq = seq;
}
else if (wrap > 0)
{
pos = seq + ~sa->seq + 1;
n_lost = ipsec_sa_anti_replay_window_shift (sa, pos, ar_huge);
sa->seq = seq;
sa->seq_hi = hi_seq;
}
else if (wrap < 0)
{
pos = ~seq + sa->seq + 1;
if (ar_huge)
clib_bitmap_set_no_check (sa->replay_window_huge,
seq & (window_size - 1), 1);
else
sa->replay_window |= (1ULL << (window_size - 1 - pos));
}
else
{
pos = sa->seq - seq;
if (ar_huge)
clib_bitmap_set_no_check (sa->replay_window_huge,
seq & (window_size - 1), 1);
else
sa->replay_window |= (1ULL << (window_size - 1 - pos));
}
}
else
{
if (seq > sa->seq)
{
pos = seq - sa->seq;
n_lost = ipsec_sa_anti_replay_window_shift (sa, pos, ar_huge);
sa->seq = seq;
}
else
{
pos = sa->seq - seq;
if (ar_huge)
clib_bitmap_set_no_check (sa->replay_window_huge,
seq & (window_size - 1), 1);
else
sa->replay_window |= (1ULL << (window_size - 1 - 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:
*/