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