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