include/net/tls.h

   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
  44 #include <net/tcp.h>
  45 #include <net/strparser.h>
  46 #include <crypto/aead.h>
  47 #include <uapi/linux/tls.h>
  48
  49
  50 /* Maximum data size carried in a TLS record */
  51 #define TLS_MAX_PAYLOAD_SIZE            ((size_t)1 << 14)
  52
  53 #define TLS_HEADER_SIZE                 5
  54 #define TLS_NONCE_OFFSET                TLS_HEADER_SIZE
  55
  56 #define TLS_CRYPTO_INFO_READY(info)     ((info)->cipher_type)
  57
  58 #define TLS_RECORD_TYPE_DATA            0x17
  59
  60 #define TLS_AAD_SPACE_SIZE              13
  61 #define TLS_DEVICE_NAME_MAX             32
  62
  63 /*
  64  * This structure defines the routines for Inline TLS driver.
  65  * The following routines are optional and filled with a
  66  * null pointer if not defined.
  67  *
  68  * @name: Its the name of registered Inline tls device
  69  * @dev_list: Inline tls device list
  70  * int (*feature)(struct tls_device *device);
  71  *     Called to return Inline TLS driver capability
  72  *
  73  * int (*hash)(struct tls_device *device, struct sock *sk);
  74  *     This function sets Inline driver for listen and program
  75  *     device specific functioanlity as required
  76  *
  77  * void (*unhash)(struct tls_device *device, struct sock *sk);
  78  *     This function cleans listen state set by Inline TLS driver
  79  *
  80  * void (*release)(struct kref *kref);
  81  *     Release the registered device and allocated resources
  82  * @kref: Number of reference to tls_device
  83  */
  84 struct tls_device {
  85         char name[TLS_DEVICE_NAME_MAX];
  86         struct list_head dev_list;
  87         int  (*feature)(struct tls_device *device);
  88         int  (*hash)(struct tls_device *device, struct sock *sk);
  89         void (*unhash)(struct tls_device *device, struct sock *sk);
  90         void (*release)(struct kref *kref);
  91         struct kref kref;
  92 };
  93
  94 enum {
  95         TLS_BASE,
  96         TLS_SW,
  97 #ifdef CONFIG_TLS_DEVICE
  98         TLS_HW,
  99 #endif
 100         TLS_HW_RECORD,
 101         TLS_NUM_CONFIG,
 102 };
 103
 104 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
 105  * allocated or mapped for each TLS record. After encryption, the records are
 106  * stores in a linked list.
 107  */
 108 struct tls_rec {
 109         struct list_head list;
 110         int tx_ready;
 111         int tx_flags;
 112         int inplace_crypto;
 113
 114         struct sk_msg msg_plaintext;
 115         struct sk_msg msg_encrypted;
 116
 117         /* AAD | msg_plaintext.sg.data | sg_tag */
 118         struct scatterlist sg_aead_in[2];
 119         /* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
 120         struct scatterlist sg_aead_out[2];
 121
 122         char content_type;
 123         struct scatterlist sg_content_type;
 124
 125         char aad_space[TLS_AAD_SPACE_SIZE];
 126         u8 iv_data[TLS_CIPHER_AES_GCM_128_IV_SIZE +
 127                    TLS_CIPHER_AES_GCM_128_SALT_SIZE];
 128         struct aead_request aead_req;
 129         u8 aead_req_ctx[];
 130 };
 131
 132 struct tls_msg {
 133         struct strp_msg rxm;
 134         u8 control;
 135 };
 136
 137 struct tx_work {
 138         struct delayed_work work;
 139         struct sock *sk;
 140 };
 141
 142 struct tls_sw_context_tx {
 143         struct crypto_aead *aead_send;
 144         struct crypto_wait async_wait;
 145         struct tx_work tx_work;
 146         struct tls_rec *open_rec;
 147         struct list_head tx_list;
 148         atomic_t encrypt_pending;
 149         int async_notify;
 150         int async_capable;
 151
 152 #define BIT_TX_SCHEDULED        0
 153         unsigned long tx_bitmask;
 154 };
 155
 156 struct tls_sw_context_rx {
 157         struct crypto_aead *aead_recv;
 158         struct crypto_wait async_wait;
 159         struct strparser strp;
 160         struct sk_buff_head rx_list;    /* list of decrypted 'data' records */
 161         void (*saved_data_ready)(struct sock *sk);
 162
 163         struct sk_buff *recv_pkt;
 164         u8 control;
 165         int async_capable;
 166         bool decrypted;
 167         atomic_t decrypt_pending;
 168         bool async_notify;
 169 };
 170
 171 struct tls_record_info {
 172         struct list_head list;
 173         u32 end_seq;
 174         int len;
 175         int num_frags;
 176         skb_frag_t frags[MAX_SKB_FRAGS];
 177 };
 178
 179 struct tls_offload_context_tx {
 180         struct crypto_aead *aead_send;
 181         spinlock_t lock;        /* protects records list */
 182         struct list_head records_list;
 183         struct tls_record_info *open_record;
 184         struct tls_record_info *retransmit_hint;
 185         u64 hint_record_sn;
 186         u64 unacked_record_sn;
 187
 188         struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
 189         void (*sk_destruct)(struct sock *sk);
 190         u8 driver_state[];
 191         /* The TLS layer reserves room for driver specific state
 192          * Currently the belief is that there is not enough
 193          * driver specific state to justify another layer of indirection
 194          */
 195 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
 196 };
 197
 198 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
 199         (ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
 200          TLS_DRIVER_STATE_SIZE)
 201
 202 struct cipher_context {
 203         char *iv;
 204         char *rec_seq;
 205 };
 206
 207 union tls_crypto_context {
 208         struct tls_crypto_info info;
 209         union {
 210                 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
 211                 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
 212         };
 213 };
 214
 215 struct tls_prot_info {
 216         u16 version;
 217         u16 cipher_type;
 218         u16 prepend_size;
 219         u16 tag_size;
 220         u16 overhead_size;
 221         u16 iv_size;
 222         u16 rec_seq_size;
 223         u16 aad_size;
 224         u16 tail_size;
 225 };
 226
 227 struct tls_context {
 228         struct tls_prot_info prot_info;
 229
 230         union tls_crypto_context crypto_send;
 231         union tls_crypto_context crypto_recv;
 232
 233         struct list_head list;
 234         struct net_device *netdev;
 235         refcount_t refcount;
 236
 237         void *priv_ctx_tx;
 238         void *priv_ctx_rx;
 239
 240         u8 tx_conf:3;
 241         u8 rx_conf:3;
 242
 243         struct cipher_context tx;
 244         struct cipher_context rx;
 245
 246         struct scatterlist *partially_sent_record;
 247         u16 partially_sent_offset;
 248
 249         unsigned long flags;
 250         bool in_tcp_sendpages;
 251         bool pending_open_record_frags;
 252
 253         int (*push_pending_record)(struct sock *sk, int flags);
 254
 255         void (*sk_write_space)(struct sock *sk);
 256         void (*sk_destruct)(struct sock *sk);
 257         void (*sk_proto_close)(struct sock *sk, long timeout);
 258
 259         int  (*setsockopt)(struct sock *sk, int level,
 260                            int optname, char __user *optval,
 261                            unsigned int optlen);
 262         int  (*getsockopt)(struct sock *sk, int level,
 263                            int optname, char __user *optval,
 264                            int __user *optlen);
 265         int  (*hash)(struct sock *sk);
 266         void (*unhash)(struct sock *sk);
 267 };
 268
 269 struct tls_offload_context_rx {
 270         /* sw must be the first member of tls_offload_context_rx */
 271         struct tls_sw_context_rx sw;
 272         atomic64_t resync_req;
 273         u8 driver_state[];
 274         /* The TLS layer reserves room for driver specific state
 275          * Currently the belief is that there is not enough
 276          * driver specific state to justify another layer of indirection
 277          */
 278 };
 279
 280 #define TLS_OFFLOAD_CONTEXT_SIZE_RX                                     \
 281         (ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
 282          TLS_DRIVER_STATE_SIZE)
 283
 284 int wait_on_pending_writer(struct sock *sk, long *timeo);
 285 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 286                 int __user *optlen);
 287 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 288                   unsigned int optlen);
 289
 290 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
 291 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 292 int tls_sw_sendpage(struct sock *sk, struct page *page,
 293                     int offset, size_t size, int flags);
 294 void tls_sw_close(struct sock *sk, long timeout);
 295 void tls_sw_free_resources_tx(struct sock *sk);
 296 void tls_sw_free_resources_rx(struct sock *sk);
 297 void tls_sw_release_resources_rx(struct sock *sk);
 298 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 299                    int nonblock, int flags, int *addr_len);
 300 bool tls_sw_stream_read(const struct sock *sk);
 301 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
 302                            struct pipe_inode_info *pipe,
 303                            size_t len, unsigned int flags);
 304
 305 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
 306 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 307 int tls_device_sendpage(struct sock *sk, struct page *page,
 308                         int offset, size_t size, int flags);
 309 void tls_device_sk_destruct(struct sock *sk);
 310 void tls_device_init(void);
 311 void tls_device_cleanup(void);
 312 int tls_tx_records(struct sock *sk, int flags);
 313
 314 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 315                                        u32 seq, u64 *p_record_sn);
 316
 317 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
 318 {
 319         return rec->len == 0;
 320 }
 321
 322 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
 323 {
 324         return rec->end_seq - rec->len;
 325 }
 326
 327 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 328 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 329                 struct scatterlist *sg, u16 first_offset,
 330                 int flags);
 331 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
 332                             int flags);
 333
 334 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
 335 {
 336         return (struct tls_msg *)strp_msg(skb);
 337 }
 338
 339 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 340 {
 341         return !!ctx->partially_sent_record;
 342 }
 343
 344 static inline int tls_complete_pending_work(struct sock *sk,
 345                                             struct tls_context *ctx,
 346                                             int flags, long *timeo)
 347 {
 348         int rc = 0;
 349
 350         if (unlikely(sk->sk_write_pending))
 351                 rc = wait_on_pending_writer(sk, timeo);
 352
 353         if (!rc && tls_is_partially_sent_record(ctx))
 354                 rc = tls_push_partial_record(sk, ctx, flags);
 355
 356         return rc;
 357 }
 358
 359 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 360 {
 361         return tls_ctx->pending_open_record_frags;
 362 }
 363
 364 static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
 365 {
 366         struct tls_rec *rec;
 367
 368         rec = list_first_entry(&ctx->tx_list, struct tls_rec, list);
 369         if (!rec)
 370                 return false;
 371
 372         return READ_ONCE(rec->tx_ready);
 373 }
 374
 375 struct sk_buff *
 376 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
 377                       struct sk_buff *skb);
 378
 379 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
 380 {
 381 #ifdef CONFIG_SOCK_VALIDATE_XMIT
 382         return sk_fullsock(sk) &
 383                (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
 384                &tls_validate_xmit_skb);
 385 #else
 386         return false;
 387 #endif
 388 }
 389
 390 static inline void tls_err_abort(struct sock *sk, int err)
 391 {
 392         sk->sk_err = err;
 393         sk->sk_error_report(sk);
 394 }
 395
 396 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 397 {
 398         int i;
 399
 400         for (i = len - 1; i >= 0; i--) {
 401                 ++seq[i];
 402                 if (seq[i] != 0)
 403                         break;
 404         }
 405
 406         return (i == -1);
 407 }
 408
 409 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 410 {
 411         struct inet_connection_sock *icsk = inet_csk(sk);
 412
 413         return icsk->icsk_ulp_data;
 414 }
 415
 416 static inline void tls_advance_record_sn(struct sock *sk,
 417                                          struct cipher_context *ctx,
 418                                          int version)
 419 {
 420         struct tls_context *tls_ctx = tls_get_ctx(sk);
 421         struct tls_prot_info *prot = &tls_ctx->prot_info;
 422
 423         if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
 424                 tls_err_abort(sk, EBADMSG);
 425
 426         if (version != TLS_1_3_VERSION) {
 427                 tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 428                                      prot->iv_size);
 429         }
 430 }
 431
 432 static inline void tls_fill_prepend(struct tls_context *ctx,
 433                              char *buf,
 434                              size_t plaintext_len,
 435                              unsigned char record_type,
 436                              int version)
 437 {
 438         struct tls_prot_info *prot = &ctx->prot_info;
 439         size_t pkt_len, iv_size = prot->iv_size;
 440
 441         pkt_len = plaintext_len + prot->tag_size;
 442         if (version != TLS_1_3_VERSION) {
 443                 pkt_len += iv_size;
 444
 445                 memcpy(buf + TLS_NONCE_OFFSET,
 446                        ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 447         }
 448
 449         /* we cover nonce explicit here as well, so buf should be of
 450          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 451          */
 452         buf[0] = version == TLS_1_3_VERSION ?
 453                    TLS_RECORD_TYPE_DATA : record_type;
 454         /* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
 455         buf[1] = TLS_1_2_VERSION_MINOR;
 456         buf[2] = TLS_1_2_VERSION_MAJOR;
 457         /* we can use IV for nonce explicit according to spec */
 458         buf[3] = pkt_len >> 8;
 459         buf[4] = pkt_len & 0xFF;
 460 }
 461
 462 static inline void tls_make_aad(char *buf,
 463                                 size_t size,
 464                                 char *record_sequence,
 465                                 int record_sequence_size,
 466                                 unsigned char record_type,
 467                                 int version)
 468 {
 469         if (version != TLS_1_3_VERSION) {
 470                 memcpy(buf, record_sequence, record_sequence_size);
 471                 buf += 8;
 472         } else {
 473                 size += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 474         }
 475
 476         buf[0] = version == TLS_1_3_VERSION ?
 477                   TLS_RECORD_TYPE_DATA : record_type;
 478         buf[1] = TLS_1_2_VERSION_MAJOR;
 479         buf[2] = TLS_1_2_VERSION_MINOR;
 480         buf[3] = size >> 8;
 481         buf[4] = size & 0xFF;
 482 }
 483
 484 static inline void xor_iv_with_seq(int version, char *iv, char *seq)
 485 {
 486         int i;
 487
 488         if (version == TLS_1_3_VERSION) {
 489                 for (i = 0; i < 8; i++)
 490                         iv[i + 4] ^= seq[i];
 491         }
 492 }
 493
 494
 495 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 496                 const struct tls_context *tls_ctx)
 497 {
 498         return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
 499 }
 500
 501 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
 502                 const struct tls_context *tls_ctx)
 503 {
 504         return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
 505 }
 506
 507 static inline struct tls_offload_context_tx *
 508 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
 509 {
 510         return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
 511 }
 512
 513 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
 514 {
 515         struct tls_context *ctx = tls_get_ctx(sk);
 516
 517         if (!ctx)
 518                 return false;
 519         return !!tls_sw_ctx_tx(ctx);
 520 }
 521
 522 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
 523 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
 524
 525 static inline struct tls_offload_context_rx *
 526 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
 527 {
 528         return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
 529 }
 530
 531 /* The TLS context is valid until sk_destruct is called */
 532 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
 533 {
 534         struct tls_context *tls_ctx = tls_get_ctx(sk);
 535         struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 536
 537         atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
 538 }
 539
 540
 541 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 542                       unsigned char *record_type);
 543 void tls_register_device(struct tls_device *device);
 544 void tls_unregister_device(struct tls_device *device);
 545 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
 546 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
 547                 struct scatterlist *sgout);
 548
 549 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
 550                                       struct net_device *dev,
 551                                       struct sk_buff *skb);
 552
 553 int tls_sw_fallback_init(struct sock *sk,
 554                          struct tls_offload_context_tx *offload_ctx,
 555                          struct tls_crypto_info *crypto_info);
 556
 557 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
 558
 559 void tls_device_offload_cleanup_rx(struct sock *sk);
 560 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
 561
 562 #endif /* _TLS_OFFLOAD_H */