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_RECORD_TYPE_DATA 0x17 63 64 #define TLS_AAD_SPACE_SIZE 13 65 66 #define MAX_IV_SIZE 16 67 #define TLS_TAG_SIZE 16 68 #define TLS_MAX_REC_SEQ_SIZE 8 69 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE 70 71 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes. 72 * 73 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3] 74 * 75 * The field 'length' is encoded in field 'b0' as '(length width - 1)'. 76 * Hence b0 contains (3 - 1) = 2. 77 */ 78 #define TLS_AES_CCM_IV_B0_BYTE 2 79 #define TLS_SM4_CCM_IV_B0_BYTE 2 80 81 enum { 82 TLS_BASE, 83 TLS_SW, 84 TLS_HW, 85 TLS_HW_RECORD, 86 TLS_NUM_CONFIG, 87 }; 88 89 struct tx_work { 90 struct delayed_work work; 91 struct sock *sk; 92 }; 93 94 struct tls_sw_context_tx { 95 struct crypto_aead *aead_send; 96 struct crypto_wait async_wait; 97 struct tx_work tx_work; 98 struct tls_rec *open_rec; 99 struct list_head tx_list; 100 atomic_t encrypt_pending; 101 /* protect crypto_wait with encrypt_pending */ 102 spinlock_t encrypt_compl_lock; 103 int async_notify; 104 u8 async_capable:1; 105 106 #define BIT_TX_SCHEDULED 0 107 #define BIT_TX_CLOSING 1 108 unsigned long tx_bitmask; 109 }; 110 111 struct tls_sw_context_rx { 112 struct crypto_aead *aead_recv; 113 struct crypto_wait async_wait; 114 struct strparser strp; 115 struct sk_buff_head rx_list; /* list of decrypted 'data' records */ 116 void (*saved_data_ready)(struct sock *sk); 117 118 struct sk_buff *recv_pkt; 119 u8 async_capable:1; 120 u8 zc_capable:1; 121 atomic_t decrypt_pending; 122 /* protect crypto_wait with decrypt_pending*/ 123 spinlock_t decrypt_compl_lock; 124 }; 125 126 struct tls_record_info { 127 struct list_head list; 128 u32 end_seq; 129 int len; 130 int num_frags; 131 skb_frag_t frags[MAX_SKB_FRAGS]; 132 }; 133 134 struct tls_offload_context_tx { 135 struct crypto_aead *aead_send; 136 spinlock_t lock; /* protects records list */ 137 struct list_head records_list; 138 struct tls_record_info *open_record; 139 struct tls_record_info *retransmit_hint; 140 u64 hint_record_sn; 141 u64 unacked_record_sn; 142 143 struct scatterlist sg_tx_data[MAX_SKB_FRAGS]; 144 void (*sk_destruct)(struct sock *sk); 145 u8 driver_state[] __aligned(8); 146 /* The TLS layer reserves room for driver specific state 147 * Currently the belief is that there is not enough 148 * driver specific state to justify another layer of indirection 149 */ 150 #define TLS_DRIVER_STATE_SIZE_TX 16 151 }; 152 153 #define TLS_OFFLOAD_CONTEXT_SIZE_TX \ 154 (sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX) 155 156 enum tls_context_flags { 157 /* tls_device_down was called after the netdev went down, device state 158 * was released, and kTLS works in software, even though rx_conf is 159 * still TLS_HW (needed for transition). 160 */ 161 TLS_RX_DEV_DEGRADED = 0, 162 /* Unlike RX where resync is driven entirely by the core in TX only 163 * the driver knows when things went out of sync, so we need the flag 164 * to be atomic. 165 */ 166 TLS_TX_SYNC_SCHED = 1, 167 /* tls_dev_del was called for the RX side, device state was released, 168 * but tls_ctx->netdev might still be kept, because TX-side driver 169 * resources might not be released yet. Used to prevent the second 170 * tls_dev_del call in tls_device_down if it happens simultaneously. 171 */ 172 TLS_RX_DEV_CLOSED = 2, 173 }; 174 175 struct cipher_context { 176 char *iv; 177 char *rec_seq; 178 }; 179 180 union tls_crypto_context { 181 struct tls_crypto_info info; 182 union { 183 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128; 184 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256; 185 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305; 186 struct tls12_crypto_info_sm4_gcm sm4_gcm; 187 struct tls12_crypto_info_sm4_ccm sm4_ccm; 188 }; 189 }; 190 191 struct tls_prot_info { 192 u16 version; 193 u16 cipher_type; 194 u16 prepend_size; 195 u16 tag_size; 196 u16 overhead_size; 197 u16 iv_size; 198 u16 salt_size; 199 u16 rec_seq_size; 200 u16 aad_size; 201 u16 tail_size; 202 }; 203 204 struct tls_context { 205 /* read-only cache line */ 206 struct tls_prot_info prot_info; 207 208 u8 tx_conf:3; 209 u8 rx_conf:3; 210 u8 zerocopy_sendfile:1; 211 u8 rx_no_pad:1; 212 213 int (*push_pending_record)(struct sock *sk, int flags); 214 void (*sk_write_space)(struct sock *sk); 215 216 void *priv_ctx_tx; 217 void *priv_ctx_rx; 218 219 struct net_device *netdev; 220 221 /* rw cache line */ 222 struct cipher_context tx; 223 struct cipher_context rx; 224 225 struct scatterlist *partially_sent_record; 226 u16 partially_sent_offset; 227 228 bool in_tcp_sendpages; 229 bool pending_open_record_frags; 230 231 struct mutex tx_lock; /* protects partially_sent_* fields and 232 * per-type TX fields 233 */ 234 unsigned long flags; 235 236 /* cache cold stuff */ 237 struct proto *sk_proto; 238 struct sock *sk; 239 240 void (*sk_destruct)(struct sock *sk); 241 242 union tls_crypto_context crypto_send; 243 union tls_crypto_context crypto_recv; 244 245 struct list_head list; 246 refcount_t refcount; 247 struct rcu_head rcu; 248 }; 249 250 enum tls_offload_ctx_dir { 251 TLS_OFFLOAD_CTX_DIR_RX, 252 TLS_OFFLOAD_CTX_DIR_TX, 253 }; 254 255 struct tlsdev_ops { 256 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk, 257 enum tls_offload_ctx_dir direction, 258 struct tls_crypto_info *crypto_info, 259 u32 start_offload_tcp_sn); 260 void (*tls_dev_del)(struct net_device *netdev, 261 struct tls_context *ctx, 262 enum tls_offload_ctx_dir direction); 263 int (*tls_dev_resync)(struct net_device *netdev, 264 struct sock *sk, u32 seq, u8 *rcd_sn, 265 enum tls_offload_ctx_dir direction); 266 }; 267 268 enum tls_offload_sync_type { 269 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0, 270 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1, 271 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2, 272 }; 273 274 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2 275 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128 276 277 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13 278 struct tls_offload_resync_async { 279 atomic64_t req; 280 u16 loglen; 281 u16 rcd_delta; 282 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX]; 283 }; 284 285 struct tls_offload_context_rx { 286 /* sw must be the first member of tls_offload_context_rx */ 287 struct tls_sw_context_rx sw; 288 enum tls_offload_sync_type resync_type; 289 /* this member is set regardless of resync_type, to avoid branches */ 290 u8 resync_nh_reset:1; 291 /* CORE_NEXT_HINT-only member, but use the hole here */ 292 u8 resync_nh_do_now:1; 293 union { 294 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */ 295 struct { 296 atomic64_t resync_req; 297 }; 298 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */ 299 struct { 300 u32 decrypted_failed; 301 u32 decrypted_tgt; 302 } resync_nh; 303 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */ 304 struct { 305 struct tls_offload_resync_async *resync_async; 306 }; 307 }; 308 u8 driver_state[] __aligned(8); 309 /* The TLS layer reserves room for driver specific state 310 * Currently the belief is that there is not enough 311 * driver specific state to justify another layer of indirection 312 */ 313 #define TLS_DRIVER_STATE_SIZE_RX 8 314 }; 315 316 #define TLS_OFFLOAD_CONTEXT_SIZE_RX \ 317 (sizeof(struct tls_offload_context_rx) + TLS_DRIVER_STATE_SIZE_RX) 318 319 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, 320 u32 seq, u64 *p_record_sn); 321 322 static inline bool tls_record_is_start_marker(struct tls_record_info *rec) 323 { 324 return rec->len == 0; 325 } 326 327 static inline u32 tls_record_start_seq(struct tls_record_info *rec) 328 { 329 return rec->end_seq - rec->len; 330 } 331 332 struct sk_buff * 333 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev, 334 struct sk_buff *skb); 335 struct sk_buff * 336 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev, 337 struct sk_buff *skb); 338 339 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk) 340 { 341 #ifdef CONFIG_SOCK_VALIDATE_XMIT 342 return sk_fullsock(sk) && 343 (smp_load_acquire(&sk->sk_validate_xmit_skb) == 344 &tls_validate_xmit_skb); 345 #else 346 return false; 347 #endif 348 } 349 350 static inline struct tls_context *tls_get_ctx(const struct sock *sk) 351 { 352 struct inet_connection_sock *icsk = inet_csk(sk); 353 354 /* Use RCU on icsk_ulp_data only for sock diag code, 355 * TLS data path doesn't need rcu_dereference(). 356 */ 357 return (__force void *)icsk->icsk_ulp_data; 358 } 359 360 static inline struct tls_sw_context_rx *tls_sw_ctx_rx( 361 const struct tls_context *tls_ctx) 362 { 363 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx; 364 } 365 366 static inline struct tls_sw_context_tx *tls_sw_ctx_tx( 367 const struct tls_context *tls_ctx) 368 { 369 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx; 370 } 371 372 static inline struct tls_offload_context_tx * 373 tls_offload_ctx_tx(const struct tls_context *tls_ctx) 374 { 375 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx; 376 } 377 378 static inline bool tls_sw_has_ctx_tx(const struct sock *sk) 379 { 380 struct tls_context *ctx = tls_get_ctx(sk); 381 382 if (!ctx) 383 return false; 384 return !!tls_sw_ctx_tx(ctx); 385 } 386 387 static inline bool tls_sw_has_ctx_rx(const struct sock *sk) 388 { 389 struct tls_context *ctx = tls_get_ctx(sk); 390 391 if (!ctx) 392 return false; 393 return !!tls_sw_ctx_rx(ctx); 394 } 395 396 static inline struct tls_offload_context_rx * 397 tls_offload_ctx_rx(const struct tls_context *tls_ctx) 398 { 399 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx; 400 } 401 402 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx, 403 enum tls_offload_ctx_dir direction) 404 { 405 if (direction == TLS_OFFLOAD_CTX_DIR_TX) 406 return tls_offload_ctx_tx(tls_ctx)->driver_state; 407 else 408 return tls_offload_ctx_rx(tls_ctx)->driver_state; 409 } 410 411 static inline void * 412 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction) 413 { 414 return __tls_driver_ctx(tls_get_ctx(sk), direction); 415 } 416 417 #define RESYNC_REQ BIT(0) 418 #define RESYNC_REQ_ASYNC BIT(1) 419 /* The TLS context is valid until sk_destruct is called */ 420 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq) 421 { 422 struct tls_context *tls_ctx = tls_get_ctx(sk); 423 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 424 425 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ); 426 } 427 428 /* Log all TLS record header TCP sequences in [seq, seq+len] */ 429 static inline void 430 tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len) 431 { 432 struct tls_context *tls_ctx = tls_get_ctx(sk); 433 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); 434 435 atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) | 436 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC); 437 rx_ctx->resync_async->loglen = 0; 438 rx_ctx->resync_async->rcd_delta = 0; 439 } 440 441 static inline void 442 tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq) 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, 448 ((u64)ntohl(seq) << 32) | RESYNC_REQ); 449 } 450 451 static inline void 452 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type) 453 { 454 struct tls_context *tls_ctx = tls_get_ctx(sk); 455 456 tls_offload_ctx_rx(tls_ctx)->resync_type = type; 457 } 458 459 /* Driver's seq tracking has to be disabled until resync succeeded */ 460 static inline bool tls_offload_tx_resync_pending(struct sock *sk) 461 { 462 struct tls_context *tls_ctx = tls_get_ctx(sk); 463 bool ret; 464 465 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags); 466 smp_mb__after_atomic(); 467 return ret; 468 } 469 470 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb); 471 472 #ifdef CONFIG_TLS_DEVICE 473 void tls_device_sk_destruct(struct sock *sk); 474 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq); 475 476 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk) 477 { 478 if (!sk_fullsock(sk) || 479 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct) 480 return false; 481 return tls_get_ctx(sk)->rx_conf == TLS_HW; 482 } 483 #endif 484 #endif /* _TLS_OFFLOAD_H */ 485