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/skmsg.h> 43 #include <linux/netdevice.h> 44 45 #include <net/tcp.h> 46 #include <net/strparser.h> 47 #include <crypto/aead.h> 48 #include <uapi/linux/tls.h> 49 50 51 /* Maximum data size carried in a TLS record */ 52 #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14) 53 54 #define TLS_HEADER_SIZE 5 55 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE 56 57 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type) 58 59 #define TLS_RECORD_TYPE_DATA 0x17 60 61 #define TLS_AAD_SPACE_SIZE 13 62 #define TLS_DEVICE_NAME_MAX 32 63 64 #define MAX_IV_SIZE 16 65 #define TLS_MAX_REC_SEQ_SIZE 8 66 67 /* For AES-CCM, the full 16-bytes of IV is made of '4' fields of given sizes. 68 * 69 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3] 70 * 71 * The field 'length' is encoded in field 'b0' as '(length width - 1)'. 72 * Hence b0 contains (3 - 1) = 2. 73 */ 74 #define TLS_AES_CCM_IV_B0_BYTE 2 75 76 /* 77 * This structure defines the routines for Inline TLS driver. 78 * The following routines are optional and filled with a 79 * null pointer if not defined. 80 * 81 * @name: Its the name of registered Inline tls device 82 * @dev_list: Inline tls device list 83 * int (*feature)(struct tls_device *device); 84 * Called to return Inline TLS driver capability 85 * 86 * int (*hash)(struct tls_device *device, struct sock *sk); 87 * This function sets Inline driver for listen and program 88 * device specific functioanlity as required 89 * 90 * void (*unhash)(struct tls_device *device, struct sock *sk); 91 * This function cleans listen state set by Inline TLS driver 92 * 93 * void (*release)(struct kref *kref); 94 * Release the registered device and allocated resources 95 * @kref: Number of reference to tls_device 96 */ 97 struct tls_device { 98 char name[TLS_DEVICE_NAME_MAX]; 99 struct list_head dev_list; 100 int (*feature)(struct tls_device *device); 101 int (*hash)(struct tls_device *device, struct sock *sk); 102 void (*unhash)(struct tls_device *device, struct sock *sk); 103 void (*release)(struct kref *kref); 104 struct kref kref; 105 }; 106 107 enum { 108 TLS_BASE, 109 TLS_SW, 110 #ifdef CONFIG_TLS_DEVICE 111 TLS_HW, 112 #endif 113 TLS_HW_RECORD, 114 TLS_NUM_CONFIG, 115 }; 116 117 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages 118 * allocated or mapped for each TLS record. After encryption, the records are 119 * stores in a linked list. 120 */ 121 struct tls_rec { 122 struct list_head list; 123 int tx_ready; 124 int tx_flags; 125 int inplace_crypto; 126 127 struct sk_msg msg_plaintext; 128 struct sk_msg msg_encrypted; 129 130 /* AAD | msg_plaintext.sg.data | sg_tag */ 131 struct scatterlist sg_aead_in[2]; 132 /* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */ 133 struct scatterlist sg_aead_out[2]; 134 135 char content_type; 136 struct scatterlist sg_content_type; 137 138 char aad_space[TLS_AAD_SPACE_SIZE]; 139 u8 iv_data[MAX_IV_SIZE]; 140 struct aead_request aead_req; 141 u8 aead_req_ctx[]; 142 }; 143 144 struct tls_msg { 145 struct strp_msg rxm; 146 u8 control; 147 }; 148 149 struct tx_work { 150 struct delayed_work work; 151 struct sock *sk; 152 }; 153 154 struct tls_sw_context_tx { 155 struct crypto_aead *aead_send; 156 struct crypto_wait async_wait; 157 struct tx_work tx_work; 158 struct tls_rec *open_rec; 159 struct list_head tx_list; 160 atomic_t encrypt_pending; 161 int async_notify; 162 int async_capable; 163 164 #define BIT_TX_SCHEDULED 0 165 unsigned long tx_bitmask; 166 }; 167 168 struct tls_sw_context_rx { 169 struct crypto_aead *aead_recv; 170 struct crypto_wait async_wait; 171 struct strparser strp; 172 struct sk_buff_head rx_list; /* list of decrypted 'data' records */ 173 void (*saved_data_ready)(struct sock *sk); 174 175 struct sk_buff *recv_pkt; 176 u8 control; 177 int async_capable; 178 bool decrypted; 179 atomic_t decrypt_pending; 180 bool async_notify; 181 }; 182 183 struct tls_record_info { 184 struct list_head list; 185 u32 end_seq; 186 int len; 187 int num_frags; 188 skb_frag_t frags[MAX_SKB_FRAGS]; 189 }; 190 191 struct tls_offload_context_tx { 192 struct crypto_aead *aead_send; 193 spinlock_t lock; /* protects records list */ 194 struct list_head records_list; 195 struct tls_record_info *open_record; 196 struct tls_record_info *retransmit_hint; 197 u64 hint_record_sn; 198 u64 unacked_record_sn; 199 200 struct scatterlist sg_tx_data[MAX_SKB_FRAGS]; 201 void (*sk_destruct)(struct sock *sk); 202 u8 driver_state[] __aligned(8); 203 /* The TLS layer reserves room for driver specific state 204 * Currently the belief is that there is not enough 205 * driver specific state to justify another layer of indirection 206 */ 207 #define TLS_DRIVER_STATE_SIZE_TX 16 208 }; 209 210 #define TLS_OFFLOAD_CONTEXT_SIZE_TX \ 211 (sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX) 212 213 enum tls_context_flags { 214 TLS_RX_SYNC_RUNNING = 0, 215 /* Unlike RX where resync is driven entirely by the core in TX only 216 * the driver knows when things went out of sync, so we need the flag 217 * to be atomic. 218 */ 219 TLS_TX_SYNC_SCHED = 1, 220 }; 221 222 struct cipher_context { 223 char *iv; 224 char *rec_seq; 225 }; 226 227 union tls_crypto_context { 228 struct tls_crypto_info info; 229 union { 230 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128; 231 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256; 232 }; 233 }; 234 235 struct tls_prot_info { 236 u16 version; 237 u16 cipher_type; 238 u16 prepend_size; 239 u16 tag_size; 240 u16 overhead_size; 241 u16 iv_size; 242 u16 salt_size; 243 u16 rec_seq_size; 244 u16 aad_size; 245 u16 tail_size; 246 }; 247 248 struct tls_context { 249 /* read-only cache line */ 250 struct tls_prot_info prot_info; 251 252 u8 tx_conf:3; 253 u8 rx_conf:3; 254 255 int (*push_pending_record)(struct sock *sk, int flags); 256 void (*sk_write_space)(struct sock *sk); 257 258 void *priv_ctx_tx; 259 void *priv_ctx_rx; 260 261 struct net_device *netdev; 262 263 /* rw cache line */ 264 struct cipher_context tx; 265 struct cipher_context rx; 266 267 struct scatterlist *partially_sent_record; 268 u16 partially_sent_offset; 269 270 bool in_tcp_sendpages; 271 bool pending_open_record_frags; 272 unsigned long flags; 273 274 /* cache cold stuff */ 275 void (*sk_destruct)(struct sock *sk); 276 void (*sk_proto_close)(struct sock *sk, long timeout); 277 278 int (*setsockopt)(struct sock *sk, int level, 279 int optname, char __user *optval, 280 unsigned int optlen); 281 int (*getsockopt)(struct sock *sk, int level, 282 int optname, char __user *optval, 283 int __user *optlen); 284 int (*hash)(struct sock *sk); 285 void (*unhash)(struct sock *sk); 286 287 union tls_crypto_context crypto_send; 288 union tls_crypto_context crypto_recv; 289 290 struct list_head list; 291 refcount_t refcount; 292 }; 293 294 enum tls_offload_ctx_dir { 295 TLS_OFFLOAD_CTX_DIR_RX, 296 TLS_OFFLOAD_CTX_DIR_TX, 297 }; 298 299 struct tlsdev_ops { 300 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk, 301 enum tls_offload_ctx_dir direction, 302 struct tls_crypto_info *crypto_info, 303 u32 start_offload_tcp_sn); 304 void (*tls_dev_del)(struct net_device *netdev, 305 struct tls_context *ctx, 306 enum tls_offload_ctx_dir direction); 307 int (*tls_dev_resync)(struct net_device *netdev, 308 struct sock *sk, u32 seq, u8 *rcd_sn, 309 enum tls_offload_ctx_dir direction); 310 }; 311 312 enum tls_offload_sync_type { 313 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0, 314 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1, 315 }; 316 317 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2 318 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128 319 320 struct tls_offload_context_rx { 321 /* sw must be the first member of tls_offload_context_rx */ 322 struct tls_sw_context_rx sw; 323 enum tls_offload_sync_type resync_type; 324 /* this member is set regardless of resync_type, to avoid branches */ 325 u8 resync_nh_reset:1; 326 /* CORE_NEXT_HINT-only member, but use the hole here */ 327 u8 resync_nh_do_now:1; 328 union { 329 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */ 330 struct { 331 atomic64_t resync_req; 332 }; 333 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */ 334 struct { 335 u32 decrypted_failed; 336 u32 decrypted_tgt; 337 } resync_nh; 338 }; 339 u8 driver_state[] __aligned(8); 340 /* The TLS layer reserves room for driver specific state 341 * Currently the belief is that there is not enough 342 * driver specific state to justify another layer of indirection 343 */ 344 #define TLS_DRIVER_STATE_SIZE_RX 8 345 }; 346 347 #define TLS_OFFLOAD_CONTEXT_SIZE_RX \ 348 (sizeof(struct tls_offload_context_rx) + TLS_DRIVER_STATE_SIZE_RX) 349 350 void tls_ctx_free(struct tls_context *ctx); 351 int wait_on_pending_writer(struct sock *sk, long *timeo); 352 int tls_sk_query(struct sock *sk, int optname, char __user *optval, 353 int __user *optlen); 354 int tls_sk_attach(struct sock *sk, int optname, char __user *optval, 355 unsigned int optlen); 356 357 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx); 358 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); 359 int tls_sw_sendpage(struct sock *sk, struct page *page, 360 int offset, size_t size, int flags); 361 void tls_sw_close(struct sock *sk, long timeout); 362 void tls_sw_free_resources_tx(struct sock *sk); 363 void tls_sw_free_resources_rx(struct sock *sk); 364 void tls_sw_release_resources_rx(struct sock *sk); 365 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 366 int nonblock, int flags, int *addr_len); 367 bool tls_sw_stream_read(const struct sock *sk); 368 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos, 369 struct pipe_inode_info *pipe, 370 size_t len, unsigned int flags); 371 372 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx); 373 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); 374 int tls_device_sendpage(struct sock *sk, struct page *page, 375 int offset, size_t size, int flags); 376 void tls_device_free_resources_tx(struct sock *sk); 377 void tls_device_init(void); 378 void tls_device_cleanup(void); 379 int tls_tx_records(struct sock *sk, int flags); 380 381 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, 382 u32 seq, u64 *p_record_sn); 383 384 static inline bool tls_record_is_start_marker(struct tls_record_info *rec) 385 { 386 return rec->len == 0; 387 } 388 389 static inline u32 tls_record_start_seq(struct tls_record_info *rec) 390 { 391 return rec->end_seq - rec->len; 392 } 393 394 int tls_push_sg(struct sock *sk, struct tls_context *ctx, 395 struct scatterlist *sg, u16 first_offset, 396 int flags); 397 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx, 398 int flags); 399 bool tls_free_partial_record(struct sock *sk, struct tls_context *ctx); 400 401 static inline struct tls_msg *tls_msg(struct sk_buff *skb) 402 { 403 return (struct tls_msg *)strp_msg(skb); 404 } 405 406 static inline bool tls_is_partially_sent_record(struct tls_context *ctx) 407 { 408 return !!ctx->partially_sent_record; 409 } 410 411 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx) 412 { 413 return tls_ctx->pending_open_record_frags; 414 } 415 416 static inline bool is_tx_ready(struct tls_sw_context_tx *ctx) 417 { 418 struct tls_rec *rec; 419 420 rec = list_first_entry(&ctx->tx_list, struct tls_rec, list); 421 if (!rec) 422 return false; 423 424 return READ_ONCE(rec->tx_ready); 425 } 426 427 struct sk_buff * 428 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev, 429 struct sk_buff *skb); 430 431 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk) 432 { 433 #ifdef CONFIG_SOCK_VALIDATE_XMIT 434 return sk_fullsock(sk) && 435 (smp_load_acquire(&sk->sk_validate_xmit_skb) == 436 &tls_validate_xmit_skb); 437 #else 438 return false; 439 #endif 440 } 441 442 static inline void tls_err_abort(struct sock *sk, int err) 443 { 444 sk->sk_err = err; 445 sk->sk_error_report(sk); 446 } 447 448 static inline bool tls_bigint_increment(unsigned char *seq, int len) 449 { 450 int i; 451 452 for (i = len - 1; i >= 0; i--) { 453 ++seq[i]; 454 if (seq[i] != 0) 455 break; 456 } 457 458 return (i == -1); 459 } 460 461 static inline struct tls_context *tls_get_ctx(const struct sock *sk) 462 { 463 struct inet_connection_sock *icsk = inet_csk(sk); 464 465 return icsk->icsk_ulp_data; 466 } 467 468 static inline void tls_advance_record_sn(struct sock *sk, 469 struct tls_prot_info *prot, 470 struct cipher_context *ctx) 471 { 472 if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size)) 473 tls_err_abort(sk, EBADMSG); 474 475 if (prot->version != TLS_1_3_VERSION) 476 tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, 477 prot->iv_size); 478 } 479 480 static inline void tls_fill_prepend(struct tls_context *ctx, 481 char *buf, 482 size_t plaintext_len, 483 unsigned char record_type, 484 int version) 485 { 486 struct tls_prot_info *prot = &ctx->prot_info; 487 size_t pkt_len, iv_size = prot->iv_size; 488 489 pkt_len = plaintext_len + prot->tag_size; 490 if (version != TLS_1_3_VERSION) { 491 pkt_len += iv_size; 492 493 memcpy(buf + TLS_NONCE_OFFSET, 494 ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size); 495 } 496 497 /* we cover nonce explicit here as well, so buf should be of 498 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE 499 */ 500 buf[0] = version == TLS_1_3_VERSION ? 501 TLS_RECORD_TYPE_DATA : record_type; 502 /* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */ 503 buf[1] = TLS_1_2_VERSION_MINOR; 504 buf[2] = TLS_1_2_VERSION_MAJOR; 505 /* we can use IV for nonce explicit according to spec */ 506 buf[3] = pkt_len >> 8; 507 buf[4] = pkt_len & 0xFF; 508 } 509 510 static inline void tls_make_aad(char *buf, 511 size_t size, 512 char *record_sequence, 513 int record_sequence_size, 514 unsigned char record_type, 515 int version) 516 { 517 if (version != TLS_1_3_VERSION) { 518 memcpy(buf, record_sequence, record_sequence_size); 519 buf += 8; 520 } else { 521 size += TLS_CIPHER_AES_GCM_128_TAG_SIZE; 522 } 523 524 buf[0] = version == TLS_1_3_VERSION ? 525 TLS_RECORD_TYPE_DATA : record_type; 526 buf[1] = TLS_1_2_VERSION_MAJOR; 527 buf[2] = TLS_1_2_VERSION_MINOR; 528 buf[3] = size >> 8; 529 buf[4] = size & 0xFF; 530 } 531 532 static inline void xor_iv_with_seq(int version, char *iv, char *seq) 533 { 534 int i; 535 536 if (version == TLS_1_3_VERSION) { 537 for (i = 0; i < 8; i++) 538 iv[i + 4] ^= seq[i]; 539 } 540 } 541 542 543 static inline struct tls_sw_context_rx *tls_sw_ctx_rx( 544 const struct tls_context *tls_ctx) 545 { 546 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx; 547 } 548 549 static inline struct tls_sw_context_tx *tls_sw_ctx_tx( 550 const struct tls_context *tls_ctx) 551 { 552 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx; 553 } 554 555 static inline struct tls_offload_context_tx * 556 tls_offload_ctx_tx(const struct tls_context *tls_ctx) 557 { 558 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx; 559 } 560 561 static inline bool tls_sw_has_ctx_tx(const struct sock *sk) 562 { 563 struct tls_context *ctx = tls_get_ctx(sk); 564 565 if (!ctx) 566 return false; 567 return !!tls_sw_ctx_tx(ctx); 568 } 569 570 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx); 571 void tls_device_write_space(struct sock *sk, struct tls_context *ctx); 572 573 static inline struct tls_offload_context_rx * 574 tls_offload_ctx_rx(const struct tls_context *tls_ctx) 575 { 576 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx; 577 } 578 579 #if IS_ENABLED(CONFIG_TLS_DEVICE) 580 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx, 581 enum tls_offload_ctx_dir direction) 582 { 583 if (direction == TLS_OFFLOAD_CTX_DIR_TX) 584 return tls_offload_ctx_tx(tls_ctx)->driver_state; 585 else 586 return tls_offload_ctx_rx(tls_ctx)->driver_state; 587 } 588 589 static inline void * 590 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction) 591 { 592 return __tls_driver_ctx(tls_get_ctx(sk), direction); 593 } 594 #endif 595 596 /* The TLS context is valid until sk_destruct is called */ 597 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq) 598 { 599 struct tls_context *tls_ctx = tls_get_ctx(sk); 600 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 601 602 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | 1); 603 } 604 605 static inline void 606 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type) 607 { 608 struct tls_context *tls_ctx = tls_get_ctx(sk); 609 610 tls_offload_ctx_rx(tls_ctx)->resync_type = type; 611 } 612 613 static inline void tls_offload_tx_resync_request(struct sock *sk) 614 { 615 struct tls_context *tls_ctx = tls_get_ctx(sk); 616 617 WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags)); 618 } 619 620 /* Driver's seq tracking has to be disabled until resync succeeded */ 621 static inline bool tls_offload_tx_resync_pending(struct sock *sk) 622 { 623 struct tls_context *tls_ctx = tls_get_ctx(sk); 624 bool ret; 625 626 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags); 627 smp_mb__after_atomic(); 628 return ret; 629 } 630 631 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg, 632 unsigned char *record_type); 633 void tls_register_device(struct tls_device *device); 634 void tls_unregister_device(struct tls_device *device); 635 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb); 636 int decrypt_skb(struct sock *sk, struct sk_buff *skb, 637 struct scatterlist *sgout); 638 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb); 639 640 struct sk_buff *tls_validate_xmit_skb(struct sock *sk, 641 struct net_device *dev, 642 struct sk_buff *skb); 643 644 int tls_sw_fallback_init(struct sock *sk, 645 struct tls_offload_context_tx *offload_ctx, 646 struct tls_crypto_info *crypto_info); 647 648 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx); 649 650 void tls_device_offload_cleanup_rx(struct sock *sk); 651 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq); 652 653 #endif /* _TLS_OFFLOAD_H */ 654