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