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 /* Minimum record size limit as per RFC8449 */ 57 #define TLS_MIN_RECORD_SIZE_LIM ((size_t)1 << 6) 58 59 #define TLS_HEADER_SIZE 5 60 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE 61 62 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type) 63 64 #define TLS_HANDSHAKE_KEYUPDATE 24 /* rfc8446 B.3: Key update */ 65 66 #define TLS_AAD_SPACE_SIZE 13 67 68 #define TLS_MAX_IV_SIZE 16 69 #define TLS_MAX_SALT_SIZE 4 70 #define TLS_TAG_SIZE 16 71 #define TLS_MAX_REC_SEQ_SIZE 8 72 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE 73 74 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes. 75 * 76 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3] 77 * 78 * The field 'length' is encoded in field 'b0' as '(length width - 1)'. 79 * Hence b0 contains (3 - 1) = 2. 80 */ 81 #define TLS_AES_CCM_IV_B0_BYTE 2 82 #define TLS_SM4_CCM_IV_B0_BYTE 2 83 84 enum { 85 TLS_BASE, 86 TLS_SW, 87 TLS_HW, 88 TLS_NUM_CONFIG, 89 }; 90 91 struct tx_work { 92 struct delayed_work work; 93 struct sock *sk; 94 }; 95 96 struct tls_sw_context_tx { 97 struct crypto_aead *aead_send; 98 struct crypto_wait async_wait; 99 struct tx_work tx_work; 100 struct tls_rec *open_rec; 101 struct list_head tx_list; 102 atomic_t encrypt_pending; 103 u8 async_capable:1; 104 105 #define BIT_TX_SCHEDULED 0 106 #define BIT_TX_CLOSING 1 107 unsigned long tx_bitmask; 108 }; 109 110 struct tls_strparser { 111 struct sock *sk; 112 113 /* Bitfield word and msg_ready are serialized by the lower 114 * socket lock; BH and worker contexts both acquire it. 115 */ 116 u32 mark : 8; 117 u32 stopped : 1; 118 u32 copy_mode : 1; 119 u32 mixed_decrypted : 1; 120 121 u32 msg_announced : 1; 122 123 bool msg_ready; 124 125 struct strp_msg stm; 126 127 struct sk_buff *anchor; 128 struct work_struct work; 129 }; 130 131 struct tls_sw_context_rx { 132 struct crypto_aead *aead_recv; 133 struct crypto_wait async_wait; 134 struct sk_buff_head rx_list; /* list of decrypted 'data' records */ 135 void (*saved_data_ready)(struct sock *sk); 136 137 u8 reader_present; 138 u8 async_capable:1; 139 u8 zc_capable:1; 140 u8 reader_contended:1; 141 bool key_update_pending; 142 143 struct tls_strparser strp; 144 145 atomic_t decrypt_pending; 146 struct sk_buff_head async_hold; 147 struct wait_queue_head wq; 148 }; 149 150 struct tls_record_info { 151 struct list_head list; 152 u32 end_seq; 153 int len; 154 int num_frags; 155 skb_frag_t frags[MAX_SKB_FRAGS]; 156 }; 157 158 #define TLS_DRIVER_STATE_SIZE_TX 16 159 struct tls_offload_context_tx { 160 struct crypto_aead *aead_send; 161 spinlock_t lock; /* protects records list */ 162 struct list_head records_list; 163 struct tls_record_info *open_record; 164 struct tls_record_info *retransmit_hint; 165 u64 hint_record_sn; 166 u64 unacked_record_sn; 167 168 struct scatterlist sg_tx_data[MAX_SKB_FRAGS]; 169 void (*sk_destruct)(struct sock *sk); 170 struct work_struct destruct_work; 171 struct tls_context *ctx; 172 /* The TLS layer reserves room for driver specific state 173 * Currently the belief is that there is not enough 174 * driver specific state to justify another layer of indirection 175 */ 176 u8 driver_state[TLS_DRIVER_STATE_SIZE_TX] __aligned(8); 177 }; 178 179 enum tls_context_flags { 180 /* tls_device_down was called after the netdev went down, device state 181 * was released, and kTLS works in software, even though rx_conf is 182 * still TLS_HW (needed for transition). 183 */ 184 TLS_RX_DEV_DEGRADED = 0, 185 /* Unlike RX where resync is driven entirely by the core in TX only 186 * the driver knows when things went out of sync, so we need the flag 187 * to be atomic. 188 */ 189 TLS_TX_SYNC_SCHED = 1, 190 /* tls_dev_del was called for the RX side, device state was released, 191 * but tls_ctx->netdev might still be kept, because TX-side driver 192 * resources might not be released yet. Used to prevent the second 193 * tls_dev_del call in tls_device_down if it happens simultaneously. 194 */ 195 TLS_RX_DEV_CLOSED = 2, 196 }; 197 198 struct cipher_context { 199 char iv[TLS_MAX_IV_SIZE + TLS_MAX_SALT_SIZE]; 200 char rec_seq[TLS_MAX_REC_SEQ_SIZE]; 201 }; 202 203 union tls_crypto_context { 204 struct tls_crypto_info info; 205 union { 206 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128; 207 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256; 208 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305; 209 struct tls12_crypto_info_sm4_gcm sm4_gcm; 210 struct tls12_crypto_info_sm4_ccm sm4_ccm; 211 }; 212 }; 213 214 struct tls_prot_info { 215 u16 version; 216 u16 cipher_type; 217 u16 prepend_size; 218 u16 tag_size; 219 u16 overhead_size; 220 u16 iv_size; 221 u16 salt_size; 222 u16 rec_seq_size; 223 u16 aad_size; 224 u16 tail_size; 225 }; 226 227 struct tls_context { 228 /* read-only cache line */ 229 struct tls_prot_info prot_info; 230 231 u8 tx_conf:3; 232 u8 rx_conf:3; 233 u8 zerocopy_sendfile:1; 234 u8 rx_no_pad:1; 235 u16 tx_max_payload_len; 236 237 int (*push_pending_record)(struct sock *sk, int flags); 238 void (*sk_write_space)(struct sock *sk); 239 240 void *priv_ctx_tx; 241 void *priv_ctx_rx; 242 243 struct net_device __rcu *netdev; 244 245 /* rw cache line */ 246 struct cipher_context tx; 247 struct cipher_context rx; 248 249 struct scatterlist *partially_sent_record; 250 u16 partially_sent_offset; 251 252 bool splicing_pages; 253 bool pending_open_record_frags; 254 255 struct mutex tx_lock; /* protects partially_sent_* fields and 256 * per-type TX fields 257 */ 258 unsigned long flags; 259 260 /* cache cold stuff */ 261 struct proto *sk_proto; 262 struct sock *sk; 263 264 void (*sk_destruct)(struct sock *sk); 265 266 union tls_crypto_context crypto_send; 267 union tls_crypto_context crypto_recv; 268 269 struct list_head list; 270 refcount_t refcount; 271 struct rcu_head rcu; 272 }; 273 274 enum tls_offload_ctx_dir { 275 TLS_OFFLOAD_CTX_DIR_RX, 276 TLS_OFFLOAD_CTX_DIR_TX, 277 }; 278 279 struct tlsdev_ops { 280 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk, 281 enum tls_offload_ctx_dir direction, 282 struct tls_crypto_info *crypto_info, 283 u32 start_offload_tcp_sn); 284 void (*tls_dev_del)(struct net_device *netdev, 285 struct tls_context *ctx, 286 enum tls_offload_ctx_dir direction); 287 int (*tls_dev_resync)(struct net_device *netdev, 288 struct sock *sk, u32 seq, u8 *rcd_sn, 289 enum tls_offload_ctx_dir direction); 290 }; 291 292 enum tls_offload_sync_type { 293 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0, 294 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1, 295 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2, 296 }; 297 298 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2 299 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128 300 301 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13 302 struct tls_offload_resync_async { 303 atomic64_t req; 304 u16 loglen; 305 u16 rcd_delta; 306 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX]; 307 }; 308 309 #define TLS_DRIVER_STATE_SIZE_RX 8 310 struct tls_offload_context_rx { 311 /* sw must be the first member of tls_offload_context_rx */ 312 struct tls_sw_context_rx sw; 313 enum tls_offload_sync_type resync_type; 314 /* this member is set regardless of resync_type, to avoid branches */ 315 u8 resync_nh_reset:1; 316 /* CORE_NEXT_HINT-only member, but use the hole here */ 317 u8 resync_nh_do_now:1; 318 union { 319 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */ 320 struct { 321 atomic64_t resync_req; 322 }; 323 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */ 324 struct { 325 u32 decrypted_failed; 326 u32 decrypted_tgt; 327 } resync_nh; 328 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */ 329 struct { 330 struct tls_offload_resync_async *resync_async; 331 }; 332 }; 333 /* The TLS layer reserves room for driver specific state 334 * Currently the belief is that there is not enough 335 * driver specific state to justify another layer of indirection 336 */ 337 u8 driver_state[TLS_DRIVER_STATE_SIZE_RX] __aligned(8); 338 }; 339 340 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, 341 u32 seq, u64 *p_record_sn); 342 343 static inline bool tls_record_is_start_marker(struct tls_record_info *rec) 344 { 345 return rec->len == 0; 346 } 347 348 static inline u32 tls_record_start_seq(struct tls_record_info *rec) 349 { 350 return rec->end_seq - rec->len; 351 } 352 353 struct sk_buff * 354 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev, 355 struct sk_buff *skb); 356 struct sk_buff * 357 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev, 358 struct sk_buff *skb); 359 360 static inline bool tls_is_skb_tx_device_offloaded(const struct sk_buff *skb) 361 { 362 #ifdef CONFIG_TLS_DEVICE 363 struct sock *sk = skb->sk; 364 365 return sk && sk_fullsock(sk) && 366 (smp_load_acquire(&sk->sk_validate_xmit_skb) == 367 &tls_validate_xmit_skb); 368 #else 369 return false; 370 #endif 371 } 372 373 static inline struct tls_context *tls_get_ctx(const struct sock *sk) 374 { 375 const struct inet_connection_sock *icsk = inet_csk(sk); 376 377 /* Use RCU on icsk_ulp_data only for sock diag code, 378 * TLS data path doesn't need rcu_dereference(). 379 */ 380 return (__force void *)icsk->icsk_ulp_data; 381 } 382 383 static inline struct tls_sw_context_rx *tls_sw_ctx_rx( 384 const struct tls_context *tls_ctx) 385 { 386 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx; 387 } 388 389 static inline struct tls_sw_context_tx *tls_sw_ctx_tx( 390 const struct tls_context *tls_ctx) 391 { 392 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx; 393 } 394 395 static inline struct tls_offload_context_tx * 396 tls_offload_ctx_tx(const struct tls_context *tls_ctx) 397 { 398 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx; 399 } 400 401 static inline bool tls_sw_has_ctx_tx(const struct sock *sk) 402 { 403 struct tls_context *ctx; 404 405 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk)) 406 return false; 407 408 ctx = tls_get_ctx(sk); 409 if (!ctx) 410 return false; 411 return !!tls_sw_ctx_tx(ctx); 412 } 413 414 static inline bool tls_sw_has_ctx_rx(const struct sock *sk) 415 { 416 struct tls_context *ctx; 417 418 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk)) 419 return false; 420 421 ctx = tls_get_ctx(sk); 422 if (!ctx) 423 return false; 424 return !!tls_sw_ctx_rx(ctx); 425 } 426 427 static inline struct tls_offload_context_rx * 428 tls_offload_ctx_rx(const struct tls_context *tls_ctx) 429 { 430 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx; 431 } 432 433 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx, 434 enum tls_offload_ctx_dir direction) 435 { 436 if (direction == TLS_OFFLOAD_CTX_DIR_TX) 437 return tls_offload_ctx_tx(tls_ctx)->driver_state; 438 else 439 return tls_offload_ctx_rx(tls_ctx)->driver_state; 440 } 441 442 static inline void * 443 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction) 444 { 445 return __tls_driver_ctx(tls_get_ctx(sk), direction); 446 } 447 448 #define RESYNC_REQ BIT(0) 449 #define RESYNC_REQ_ASYNC BIT(1) 450 /* The TLS context is valid until sk_destruct is called */ 451 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq) 452 { 453 struct tls_context *tls_ctx = tls_get_ctx(sk); 454 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 455 456 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ); 457 } 458 459 /* Log all TLS record header TCP sequences in [seq, seq+len] */ 460 static inline void 461 tls_offload_rx_resync_async_request_start(struct tls_offload_resync_async *resync_async, 462 __be32 seq, u16 len) 463 { 464 atomic64_set(&resync_async->req, ((u64)ntohl(seq) << 32) | 465 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC); 466 resync_async->loglen = 0; 467 resync_async->rcd_delta = 0; 468 } 469 470 static inline void 471 tls_offload_rx_resync_async_request_end(struct tls_offload_resync_async *resync_async, 472 __be32 seq) 473 { 474 atomic64_set(&resync_async->req, ((u64)ntohl(seq) << 32) | RESYNC_REQ); 475 } 476 477 static inline void 478 tls_offload_rx_resync_async_request_cancel(struct tls_offload_resync_async *resync_async) 479 { 480 atomic64_set(&resync_async->req, 0); 481 } 482 483 static inline void 484 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type) 485 { 486 struct tls_context *tls_ctx = tls_get_ctx(sk); 487 488 tls_offload_ctx_rx(tls_ctx)->resync_type = type; 489 } 490 491 /* Driver's seq tracking has to be disabled until resync succeeded */ 492 static inline bool tls_offload_tx_resync_pending(struct sock *sk) 493 { 494 struct tls_context *tls_ctx = tls_get_ctx(sk); 495 bool ret; 496 497 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags); 498 smp_mb__after_atomic(); 499 return ret; 500 } 501 502 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb); 503 504 #ifdef CONFIG_TLS_DEVICE 505 void tls_device_sk_destruct(struct sock *sk); 506 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq); 507 508 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk) 509 { 510 if (!sk_fullsock(sk) || 511 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct) 512 return false; 513 return tls_get_ctx(sk)->rx_conf == TLS_HW; 514 } 515 #endif 516 #endif /* _TLS_OFFLOAD_H */ 517