1 /* 2 * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved. 3 * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved. 4 * 5 * This software is available to you under a choice of one of two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the 9 * OpenIB.org BSD license below: 10 * 11 * Redistribution and use in source and binary forms, with or 12 * without modification, are permitted provided that the following 13 * conditions are met: 14 * 15 * - Redistributions of source code must retain the above 16 * copyright notice, this list of conditions and the following 17 * disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials 22 * provided with the distribution. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 31 * SOFTWARE. 32 */ 33 34 #ifndef _TLS_OFFLOAD_H 35 #define _TLS_OFFLOAD_H 36 37 #include <linux/types.h> 38 #include <asm/byteorder.h> 39 #include <linux/crypto.h> 40 #include <linux/socket.h> 41 #include <linux/tcp.h> 42 #include <linux/mutex.h> 43 #include <linux/netdevice.h> 44 #include <linux/rcupdate.h> 45 46 #include <net/net_namespace.h> 47 #include <net/tcp.h> 48 #include <net/strparser.h> 49 #include <crypto/aead.h> 50 #include <uapi/linux/tls.h> 51 52 struct tls_rec; 53 54 /* Maximum data size carried in a TLS record */ 55 #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14) 56 57 #define TLS_HEADER_SIZE 5 58 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE 59 60 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type) 61 62 #define TLS_HANDSHAKE_KEYUPDATE 24 /* rfc8446 B.3: Key update */ 63 64 #define TLS_AAD_SPACE_SIZE 13 65 66 #define TLS_MAX_IV_SIZE 16 67 #define TLS_MAX_SALT_SIZE 4 68 #define TLS_TAG_SIZE 16 69 #define TLS_MAX_REC_SEQ_SIZE 8 70 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE 71 72 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes. 73 * 74 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3] 75 * 76 * The field 'length' is encoded in field 'b0' as '(length width - 1)'. 77 * Hence b0 contains (3 - 1) = 2. 78 */ 79 #define TLS_AES_CCM_IV_B0_BYTE 2 80 #define TLS_SM4_CCM_IV_B0_BYTE 2 81 82 enum { 83 TLS_BASE, 84 TLS_SW, 85 TLS_HW, 86 TLS_HW_RECORD, 87 TLS_NUM_CONFIG, 88 }; 89 90 struct tx_work { 91 struct delayed_work work; 92 struct sock *sk; 93 }; 94 95 struct tls_sw_context_tx { 96 struct crypto_aead *aead_send; 97 struct crypto_wait async_wait; 98 struct tx_work tx_work; 99 struct tls_rec *open_rec; 100 struct list_head tx_list; 101 atomic_t encrypt_pending; 102 u8 async_capable:1; 103 104 #define BIT_TX_SCHEDULED 0 105 #define BIT_TX_CLOSING 1 106 unsigned long tx_bitmask; 107 }; 108 109 struct tls_strparser { 110 struct sock *sk; 111 112 u32 mark : 8; 113 u32 stopped : 1; 114 u32 copy_mode : 1; 115 u32 mixed_decrypted : 1; 116 117 bool msg_ready; 118 119 struct strp_msg stm; 120 121 struct sk_buff *anchor; 122 struct work_struct work; 123 }; 124 125 struct tls_sw_context_rx { 126 struct crypto_aead *aead_recv; 127 struct crypto_wait async_wait; 128 struct sk_buff_head rx_list; /* list of decrypted 'data' records */ 129 void (*saved_data_ready)(struct sock *sk); 130 131 u8 reader_present; 132 u8 async_capable:1; 133 u8 zc_capable:1; 134 u8 reader_contended:1; 135 bool key_update_pending; 136 137 struct tls_strparser strp; 138 139 atomic_t decrypt_pending; 140 struct sk_buff_head async_hold; 141 struct wait_queue_head wq; 142 }; 143 144 struct tls_record_info { 145 struct list_head list; 146 u32 end_seq; 147 int len; 148 int num_frags; 149 skb_frag_t frags[MAX_SKB_FRAGS]; 150 }; 151 152 #define TLS_DRIVER_STATE_SIZE_TX 16 153 struct tls_offload_context_tx { 154 struct crypto_aead *aead_send; 155 spinlock_t lock; /* protects records list */ 156 struct list_head records_list; 157 struct tls_record_info *open_record; 158 struct tls_record_info *retransmit_hint; 159 u64 hint_record_sn; 160 u64 unacked_record_sn; 161 162 struct scatterlist sg_tx_data[MAX_SKB_FRAGS]; 163 void (*sk_destruct)(struct sock *sk); 164 struct work_struct destruct_work; 165 struct tls_context *ctx; 166 /* The TLS layer reserves room for driver specific state 167 * Currently the belief is that there is not enough 168 * driver specific state to justify another layer of indirection 169 */ 170 u8 driver_state[TLS_DRIVER_STATE_SIZE_TX] __aligned(8); 171 }; 172 173 enum tls_context_flags { 174 /* tls_device_down was called after the netdev went down, device state 175 * was released, and kTLS works in software, even though rx_conf is 176 * still TLS_HW (needed for transition). 177 */ 178 TLS_RX_DEV_DEGRADED = 0, 179 /* Unlike RX where resync is driven entirely by the core in TX only 180 * the driver knows when things went out of sync, so we need the flag 181 * to be atomic. 182 */ 183 TLS_TX_SYNC_SCHED = 1, 184 /* tls_dev_del was called for the RX side, device state was released, 185 * but tls_ctx->netdev might still be kept, because TX-side driver 186 * resources might not be released yet. Used to prevent the second 187 * tls_dev_del call in tls_device_down if it happens simultaneously. 188 */ 189 TLS_RX_DEV_CLOSED = 2, 190 }; 191 192 struct cipher_context { 193 char iv[TLS_MAX_IV_SIZE + TLS_MAX_SALT_SIZE]; 194 char rec_seq[TLS_MAX_REC_SEQ_SIZE]; 195 }; 196 197 union tls_crypto_context { 198 struct tls_crypto_info info; 199 union { 200 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128; 201 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256; 202 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305; 203 struct tls12_crypto_info_sm4_gcm sm4_gcm; 204 struct tls12_crypto_info_sm4_ccm sm4_ccm; 205 }; 206 }; 207 208 struct tls_prot_info { 209 u16 version; 210 u16 cipher_type; 211 u16 prepend_size; 212 u16 tag_size; 213 u16 overhead_size; 214 u16 iv_size; 215 u16 salt_size; 216 u16 rec_seq_size; 217 u16 aad_size; 218 u16 tail_size; 219 }; 220 221 struct tls_context { 222 /* read-only cache line */ 223 struct tls_prot_info prot_info; 224 225 u8 tx_conf:3; 226 u8 rx_conf:3; 227 u8 zerocopy_sendfile:1; 228 u8 rx_no_pad:1; 229 230 int (*push_pending_record)(struct sock *sk, int flags); 231 void (*sk_write_space)(struct sock *sk); 232 233 void *priv_ctx_tx; 234 void *priv_ctx_rx; 235 236 struct net_device __rcu *netdev; 237 238 /* rw cache line */ 239 struct cipher_context tx; 240 struct cipher_context rx; 241 242 struct scatterlist *partially_sent_record; 243 u16 partially_sent_offset; 244 245 bool splicing_pages; 246 bool pending_open_record_frags; 247 248 struct mutex tx_lock; /* protects partially_sent_* fields and 249 * per-type TX fields 250 */ 251 unsigned long flags; 252 253 /* cache cold stuff */ 254 struct proto *sk_proto; 255 struct sock *sk; 256 257 void (*sk_destruct)(struct sock *sk); 258 259 union tls_crypto_context crypto_send; 260 union tls_crypto_context crypto_recv; 261 262 struct list_head list; 263 refcount_t refcount; 264 struct rcu_head rcu; 265 }; 266 267 enum tls_offload_ctx_dir { 268 TLS_OFFLOAD_CTX_DIR_RX, 269 TLS_OFFLOAD_CTX_DIR_TX, 270 }; 271 272 struct tlsdev_ops { 273 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk, 274 enum tls_offload_ctx_dir direction, 275 struct tls_crypto_info *crypto_info, 276 u32 start_offload_tcp_sn); 277 void (*tls_dev_del)(struct net_device *netdev, 278 struct tls_context *ctx, 279 enum tls_offload_ctx_dir direction); 280 int (*tls_dev_resync)(struct net_device *netdev, 281 struct sock *sk, u32 seq, u8 *rcd_sn, 282 enum tls_offload_ctx_dir direction); 283 }; 284 285 enum tls_offload_sync_type { 286 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0, 287 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1, 288 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2, 289 }; 290 291 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2 292 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128 293 294 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13 295 struct tls_offload_resync_async { 296 atomic64_t req; 297 u16 loglen; 298 u16 rcd_delta; 299 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX]; 300 }; 301 302 #define TLS_DRIVER_STATE_SIZE_RX 8 303 struct tls_offload_context_rx { 304 /* sw must be the first member of tls_offload_context_rx */ 305 struct tls_sw_context_rx sw; 306 enum tls_offload_sync_type resync_type; 307 /* this member is set regardless of resync_type, to avoid branches */ 308 u8 resync_nh_reset:1; 309 /* CORE_NEXT_HINT-only member, but use the hole here */ 310 u8 resync_nh_do_now:1; 311 union { 312 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */ 313 struct { 314 atomic64_t resync_req; 315 }; 316 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */ 317 struct { 318 u32 decrypted_failed; 319 u32 decrypted_tgt; 320 } resync_nh; 321 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */ 322 struct { 323 struct tls_offload_resync_async *resync_async; 324 }; 325 }; 326 /* The TLS layer reserves room for driver specific state 327 * Currently the belief is that there is not enough 328 * driver specific state to justify another layer of indirection 329 */ 330 u8 driver_state[TLS_DRIVER_STATE_SIZE_RX] __aligned(8); 331 }; 332 333 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, 334 u32 seq, u64 *p_record_sn); 335 336 static inline bool tls_record_is_start_marker(struct tls_record_info *rec) 337 { 338 return rec->len == 0; 339 } 340 341 static inline u32 tls_record_start_seq(struct tls_record_info *rec) 342 { 343 return rec->end_seq - rec->len; 344 } 345 346 struct sk_buff * 347 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev, 348 struct sk_buff *skb); 349 struct sk_buff * 350 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev, 351 struct sk_buff *skb); 352 353 static inline bool tls_is_skb_tx_device_offloaded(const struct sk_buff *skb) 354 { 355 #ifdef CONFIG_TLS_DEVICE 356 struct sock *sk = skb->sk; 357 358 return sk && sk_fullsock(sk) && 359 (smp_load_acquire(&sk->sk_validate_xmit_skb) == 360 &tls_validate_xmit_skb); 361 #else 362 return false; 363 #endif 364 } 365 366 static inline struct tls_context *tls_get_ctx(const struct sock *sk) 367 { 368 const struct inet_connection_sock *icsk = inet_csk(sk); 369 370 /* Use RCU on icsk_ulp_data only for sock diag code, 371 * TLS data path doesn't need rcu_dereference(). 372 */ 373 return (__force void *)icsk->icsk_ulp_data; 374 } 375 376 static inline struct tls_sw_context_rx *tls_sw_ctx_rx( 377 const struct tls_context *tls_ctx) 378 { 379 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx; 380 } 381 382 static inline struct tls_sw_context_tx *tls_sw_ctx_tx( 383 const struct tls_context *tls_ctx) 384 { 385 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx; 386 } 387 388 static inline struct tls_offload_context_tx * 389 tls_offload_ctx_tx(const struct tls_context *tls_ctx) 390 { 391 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx; 392 } 393 394 static inline bool tls_sw_has_ctx_tx(const struct sock *sk) 395 { 396 struct tls_context *ctx; 397 398 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk)) 399 return false; 400 401 ctx = tls_get_ctx(sk); 402 if (!ctx) 403 return false; 404 return !!tls_sw_ctx_tx(ctx); 405 } 406 407 static inline bool tls_sw_has_ctx_rx(const struct sock *sk) 408 { 409 struct tls_context *ctx; 410 411 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk)) 412 return false; 413 414 ctx = tls_get_ctx(sk); 415 if (!ctx) 416 return false; 417 return !!tls_sw_ctx_rx(ctx); 418 } 419 420 static inline struct tls_offload_context_rx * 421 tls_offload_ctx_rx(const struct tls_context *tls_ctx) 422 { 423 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx; 424 } 425 426 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx, 427 enum tls_offload_ctx_dir direction) 428 { 429 if (direction == TLS_OFFLOAD_CTX_DIR_TX) 430 return tls_offload_ctx_tx(tls_ctx)->driver_state; 431 else 432 return tls_offload_ctx_rx(tls_ctx)->driver_state; 433 } 434 435 static inline void * 436 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction) 437 { 438 return __tls_driver_ctx(tls_get_ctx(sk), direction); 439 } 440 441 #define RESYNC_REQ BIT(0) 442 #define RESYNC_REQ_ASYNC BIT(1) 443 /* The TLS context is valid until sk_destruct is called */ 444 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq) 445 { 446 struct tls_context *tls_ctx = tls_get_ctx(sk); 447 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 448 449 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ); 450 } 451 452 /* Log all TLS record header TCP sequences in [seq, seq+len] */ 453 static inline void 454 tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len) 455 { 456 struct tls_context *tls_ctx = tls_get_ctx(sk); 457 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 458 459 atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) | 460 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC); 461 rx_ctx->resync_async->loglen = 0; 462 rx_ctx->resync_async->rcd_delta = 0; 463 } 464 465 static inline void 466 tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq) 467 { 468 struct tls_context *tls_ctx = tls_get_ctx(sk); 469 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 470 471 atomic64_set(&rx_ctx->resync_async->req, 472 ((u64)ntohl(seq) << 32) | RESYNC_REQ); 473 } 474 475 static inline void 476 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type) 477 { 478 struct tls_context *tls_ctx = tls_get_ctx(sk); 479 480 tls_offload_ctx_rx(tls_ctx)->resync_type = type; 481 } 482 483 /* Driver's seq tracking has to be disabled until resync succeeded */ 484 static inline bool tls_offload_tx_resync_pending(struct sock *sk) 485 { 486 struct tls_context *tls_ctx = tls_get_ctx(sk); 487 bool ret; 488 489 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags); 490 smp_mb__after_atomic(); 491 return ret; 492 } 493 494 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb); 495 496 #ifdef CONFIG_TLS_DEVICE 497 void tls_device_sk_destruct(struct sock *sk); 498 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq); 499 500 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk) 501 { 502 if (!sk_fullsock(sk) || 503 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct) 504 return false; 505 return tls_get_ctx(sk)->rx_conf == TLS_HW; 506 } 507 #endif 508 #endif /* _TLS_OFFLOAD_H */ 509