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