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