X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvnet%2Fipsec%2Fipsec_sa.h;h=4f73f1eab0f64152b6de588d8d1c087e54c82f39;hb=HEAD;hp=12700ccaa3975a5dd5dd1963fbb3791d63173f1c;hpb=7c22ff72aa54d15484fdc70e0c1b8a9ec5e880e0;p=vpp.git diff --git a/src/vnet/ipsec/ipsec_sa.h b/src/vnet/ipsec/ipsec_sa.h index 12700ccaa39..4f73f1eab0f 100644 --- a/src/vnet/ipsec/ipsec_sa.h +++ b/src/vnet/ipsec/ipsec_sa.h @@ -16,24 +16,33 @@ #define __IPSEC_SPD_SA_H__ #include +#include +#include #include #include - -#define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (64) - -#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") +#include + +#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 { @@ -41,7 +50,25 @@ typedef enum foreach_ipsec_crypto_alg #undef _ IPSEC_CRYPTO_N_ALG, -} ipsec_crypto_alg_t; +} __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") \ @@ -58,15 +85,13 @@ typedef enum foreach_ipsec_integ_alg #undef _ IPSEC_INTEG_N_ALG, -} ipsec_integ_alg_t; +} __clib_packed ipsec_integ_alg_t; typedef enum { IPSEC_PROTOCOL_AH = 0, IPSEC_PROTOCOL_ESP = 1 -} ipsec_protocol_t; - -#define IPSEC_N_PROTOCOLS (IPSEC_PROTOCOL_ESP+1) +} __clib_packed ipsec_protocol_t; #define IPSEC_KEY_MAX_LEN 128 typedef struct ipsec_key_t_ @@ -83,15 +108,21 @@ typedef struct ipsec_key_t_ * 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_GRE, "GRE") \ - _ (64, IS_INBOUND, "inboud") \ +#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_ { @@ -100,33 +131,68 @@ typedef enum ipsec_sad_flags_t_ #undef _ } __clib_packed ipsec_sa_flags_t; -STATIC_ASSERT (sizeof (ipsec_sa_flags_t) == 1, "IPSEC SA flags > 1 byte"); +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); - /* flags */ - ipsec_sa_flags_t flags; + 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; - u8 crypto_iv_size; - u8 crypto_block_size; - u8 integ_icv_size; u32 spi; u32 seq; u32 seq_hi; - u32 last_seq; - u32 last_seq_hi; - u64 replay_window; - vnet_crypto_op_type_t crypto_enc_op_type; - vnet_crypto_op_type_t crypto_dec_op_type; - vnet_crypto_op_type_t integ_op_type; + u16 crypto_enc_op_id; + u16 crypto_dec_op_id; + u16 integ_op_id; + ipsec_sa_flags_t flags; + u16 thread_index; - dpo_id_t dpo[IPSEC_N_PROTOCOLS]; + u16 integ_icv_size : 6; + u16 crypto_iv_size : 5; + u16 esp_block_align : 5; - /* data accessed by dataplane code should be above this comment */ - CLIB_CACHE_LINE_ALIGN_MARK (cacheline1); + CLIB_CACHE_LINE_ALIGN_MARK (cacheline1); union { @@ -135,215 +201,649 @@ typedef struct }; 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; - ipsec_protocol_t protocol; - + 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_key_t crypto_key; - ipsec_integ_alg_t integ_alg; - ipsec_key_t integ_key; - - 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; - u32 salt; - - /* runtime */ + 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); -#define _(a,v,s) \ - always_inline int \ - ipsec_sa_is_set_##v (const ipsec_sa_t *sa) { \ - return (sa->flags & IPSEC_SA_FLAG_##v); \ +/** + * 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 int \ - ipsec_sa_set_##v (ipsec_sa_t *sa) { \ - return (sa->flags |= IPSEC_SA_FLAG_##v); \ +#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 _ -/** - * @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 (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, - const ip46_address_t * tunnel_src_addr, - const ip46_address_t * tunnel_dst_addr, - u32 * sa_index); -extern u32 ipsec_sa_del (u32 id); -extern void ipsec_sa_stack (ipsec_sa_t * sa); -extern void ipsec_sa_set_crypto_alg (ipsec_sa_t * sa, +#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, +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); -extern u8 ipsec_is_sa_used (u32 sa_index); -extern int ipsec_set_sa_key (u32 id, - const ipsec_key_t * ck, const ipsec_key_t * ik); -extern u32 ipsec_get_sa_index_by_sa_id (u32 sa_id); - -typedef walk_rc_t (*ipsec_sa_walk_cb_t) (ipsec_sa_t * sa, void *ctx); +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); +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 (ipsec_sa_t * sa, u32 * seqp) +ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq, bool ar_huge) { - u32 seq, diff, tl, th; - if ((sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0) - return 0; + u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge); - seq = clib_net_to_host_u32 (*seqp); + /* 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; - if ((sa->flags & IPSEC_SA_FLAG_USE_ESN) == 0) + 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 (PREDICT_TRUE (seq > sa->last_seq)) + if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) return 0; - diff = sa->last_seq - seq; + if (PREDICT_TRUE (seq > sa->seq)) + return 0; - if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff) - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; - else + /* does the packet fall out on the left of the window */ + if (sa->seq >= seq + window_size) return 1; - return 0; + return ipsec_sa_anti_replay_check (sa, seq, ar_huge); } - tl = sa->last_seq; - th = sa->last_seq_hi; - diff = tl - seq; + 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 (tl >= (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE - 1))) + if (PREDICT_TRUE (sa->seq >= window_size - 1)) { - if (seq >= (tl - IPSEC_SA_ANTI_REPLAY_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) { - sa->seq_hi = th; - if (seq <= tl) - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; + /* + * 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 - return 0; + { + /* 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 { - sa->seq_hi = th + 1; - return 0; + /* + * 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 { - if (seq >= (tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1)) + /* + * 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) { - sa->seq_hi = th - 1; - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; + /* + * 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 { - sa->seq_hi = th; - if (seq <= tl) - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; - else - return 0; + /* + * 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 void -ipsec_sa_anti_replay_advance (ipsec_sa_t * sa, u32 * seqp) +always_inline u32 +ipsec_sa_anti_replay_window_shift (ipsec_sa_t *sa, u32 inc, bool ar_huge) { - u32 pos, seq; - if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0) - return; + u32 n_lost = 0; + u32 seen = 0; + u32 window_size = IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE_KNOWN_WIN (sa, ar_huge); - seq = clib_host_to_net_u32 (*seqp); - if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ESN)) + if (inc < window_size) { - int wrap = sa->seq_hi - sa->last_seq_hi; - - if (wrap == 0 && seq > sa->last_seq) + if (ar_huge) { - pos = seq - sa->last_seq; - if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE) - sa->replay_window = ((sa->replay_window) << pos) | 1; + /* 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 - sa->replay_window = 1; - sa->last_seq = seq; + { + 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->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; + 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->last_seq + 1; - sa->replay_window |= (1ULL << pos); + 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->last_seq - seq; - sa->replay_window |= (1ULL << pos); + 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->last_seq) + if (seq > sa->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; + pos = seq - sa->seq; + n_lost = ipsec_sa_anti_replay_window_shift (sa, pos, ar_huge); + sa->seq = seq; } else { - pos = sa->last_seq - seq; - sa->replay_window |= (1ULL << pos); + 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__ */