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 enum tls_context_flags {
 203         TLS_RX_SYNC_RUNNING = 0,
 204 };
 205
 206 struct cipher_context {
 207         char *iv;
 208         char *rec_seq;
 209 };
 210
 211 union tls_crypto_context {
 212         struct tls_crypto_info info;
 213         union {
 214                 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
 215                 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
 216         };
 217 };
 218
 219 struct tls_prot_info {
 220         u16 version;
 221         u16 cipher_type;
 222         u16 prepend_size;
 223         u16 tag_size;
 224         u16 overhead_size;
 225         u16 iv_size;
 226         u16 rec_seq_size;
 227         u16 aad_size;
 228         u16 tail_size;
 229 };
 230
 231 struct tls_context {
 232         struct tls_prot_info prot_info;
 233
 234         union tls_crypto_context crypto_send;
 235         union tls_crypto_context crypto_recv;
 236
 237         struct list_head list;
 238         struct net_device *netdev;
 239         refcount_t refcount;
 240
 241         void *priv_ctx_tx;
 242         void *priv_ctx_rx;
 243
 244         u8 tx_conf:3;
 245         u8 rx_conf:3;
 246
 247         struct cipher_context tx;
 248         struct cipher_context rx;
 249
 250         struct scatterlist *partially_sent_record;
 251         u16 partially_sent_offset;
 252
 253         unsigned long flags;
 254         bool in_tcp_sendpages;
 255         bool pending_open_record_frags;
 256
 257         int (*push_pending_record)(struct sock *sk, int flags);
 258
 259         void (*sk_write_space)(struct sock *sk);
 260         void (*sk_destruct)(struct sock *sk);
 261         void (*sk_proto_close)(struct sock *sk, long timeout);
 262
 263         int  (*setsockopt)(struct sock *sk, int level,
 264                            int optname, char __user *optval,
 265                            unsigned int optlen);
 266         int  (*getsockopt)(struct sock *sk, int level,
 267                            int optname, char __user *optval,
 268                            int __user *optlen);
 269         int  (*hash)(struct sock *sk);
 270         void (*unhash)(struct sock *sk);
 271 };
 272
 273 struct tls_offload_context_rx {
 274         /* sw must be the first member of tls_offload_context_rx */
 275         struct tls_sw_context_rx sw;
 276         atomic64_t resync_req;
 277         u8 driver_state[];
 278         /* The TLS layer reserves room for driver specific state
 279          * Currently the belief is that there is not enough
 280          * driver specific state to justify another layer of indirection
 281          */
 282 };
 283
 284 #define TLS_OFFLOAD_CONTEXT_SIZE_RX                                     \
 285         (ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
 286          TLS_DRIVER_STATE_SIZE)
 287
 288 int wait_on_pending_writer(struct sock *sk, long *timeo);
 289 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 290                 int __user *optlen);
 291 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 292                   unsigned int optlen);
 293
 294 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
 295 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 296 int tls_sw_sendpage(struct sock *sk, struct page *page,
 297                     int offset, size_t size, int flags);
 298 void tls_sw_close(struct sock *sk, long timeout);
 299 void tls_sw_free_resources_tx(struct sock *sk);
 300 void tls_sw_free_resources_rx(struct sock *sk);
 301 void tls_sw_release_resources_rx(struct sock *sk);
 302 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 303                    int nonblock, int flags, int *addr_len);
 304 bool tls_sw_stream_read(const struct sock *sk);
 305 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
 306                            struct pipe_inode_info *pipe,
 307                            size_t len, unsigned int flags);
 308
 309 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
 310 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 311 int tls_device_sendpage(struct sock *sk, struct page *page,
 312                         int offset, size_t size, int flags);
 313 void tls_device_sk_destruct(struct sock *sk);
 314 void tls_device_free_resources_tx(struct sock *sk);
 315 void tls_device_init(void);
 316 void tls_device_cleanup(void);
 317 int tls_tx_records(struct sock *sk, int flags);
 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 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 333 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 334                 struct scatterlist *sg, u16 first_offset,
 335                 int flags);
 336 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
 337                             int flags);
 338 bool tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
 339
 340 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
 341 {
 342         return (struct tls_msg *)strp_msg(skb);
 343 }
 344
 345 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 346 {
 347         return !!ctx->partially_sent_record;
 348 }
 349
 350 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 351 {
 352         return tls_ctx->pending_open_record_frags;
 353 }
 354
 355 static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
 356 {
 357         struct tls_rec *rec;
 358
 359         rec = list_first_entry(&ctx->tx_list, struct tls_rec, list);
 360         if (!rec)
 361                 return false;
 362
 363         return READ_ONCE(rec->tx_ready);
 364 }
 365
 366 struct sk_buff *
 367 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
 368                       struct sk_buff *skb);
 369
 370 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
 371 {
 372 #ifdef CONFIG_SOCK_VALIDATE_XMIT
 373         return sk_fullsock(sk) &&
 374                (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
 375                &tls_validate_xmit_skb);
 376 #else
 377         return false;
 378 #endif
 379 }
 380
 381 static inline void tls_err_abort(struct sock *sk, int err)
 382 {
 383         sk->sk_err = err;
 384         sk->sk_error_report(sk);
 385 }
 386
 387 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 388 {
 389         int i;
 390
 391         for (i = len - 1; i >= 0; i--) {
 392                 ++seq[i];
 393                 if (seq[i] != 0)
 394                         break;
 395         }
 396
 397         return (i == -1);
 398 }
 399
 400 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 401 {
 402         struct inet_connection_sock *icsk = inet_csk(sk);
 403
 404         return icsk->icsk_ulp_data;
 405 }
 406
 407 static inline void tls_advance_record_sn(struct sock *sk,
 408                                          struct cipher_context *ctx,
 409                                          int version)
 410 {
 411         struct tls_context *tls_ctx = tls_get_ctx(sk);
 412         struct tls_prot_info *prot = &tls_ctx->prot_info;
 413
 414         if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
 415                 tls_err_abort(sk, EBADMSG);
 416
 417         if (version != TLS_1_3_VERSION) {
 418                 tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 419                                      prot->iv_size);
 420         }
 421 }
 422
 423 static inline void tls_fill_prepend(struct tls_context *ctx,
 424                              char *buf,
 425                              size_t plaintext_len,
 426                              unsigned char record_type,
 427                              int version)
 428 {
 429         struct tls_prot_info *prot = &ctx->prot_info;
 430         size_t pkt_len, iv_size = prot->iv_size;
 431
 432         pkt_len = plaintext_len + prot->tag_size;
 433         if (version != TLS_1_3_VERSION) {
 434                 pkt_len += iv_size;
 435
 436                 memcpy(buf + TLS_NONCE_OFFSET,
 437                        ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 438         }
 439
 440         /* we cover nonce explicit here as well, so buf should be of
 441          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 442          */
 443         buf[0] = version == TLS_1_3_VERSION ?
 444                    TLS_RECORD_TYPE_DATA : record_type;
 445         /* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
 446         buf[1] = TLS_1_2_VERSION_MINOR;
 447         buf[2] = TLS_1_2_VERSION_MAJOR;
 448         /* we can use IV for nonce explicit according to spec */
 449         buf[3] = pkt_len >> 8;
 450         buf[4] = pkt_len & 0xFF;
 451 }
 452
 453 static inline void tls_make_aad(char *buf,
 454                                 size_t size,
 455                                 char *record_sequence,
 456                                 int record_sequence_size,
 457                                 unsigned char record_type,
 458                                 int version)
 459 {
 460         if (version != TLS_1_3_VERSION) {
 461                 memcpy(buf, record_sequence, record_sequence_size);
 462                 buf += 8;
 463         } else {
 464                 size += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 465         }
 466
 467         buf[0] = version == TLS_1_3_VERSION ?
 468                   TLS_RECORD_TYPE_DATA : record_type;
 469         buf[1] = TLS_1_2_VERSION_MAJOR;
 470         buf[2] = TLS_1_2_VERSION_MINOR;
 471         buf[3] = size >> 8;
 472         buf[4] = size & 0xFF;
 473 }
 474
 475 static inline void xor_iv_with_seq(int version, char *iv, char *seq)
 476 {
 477         int i;
 478
 479         if (version == TLS_1_3_VERSION) {
 480                 for (i = 0; i < 8; i++)
 481                         iv[i + 4] ^= seq[i];
 482         }
 483 }
 484
 485
 486 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 487                 const struct tls_context *tls_ctx)
 488 {
 489         return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
 490 }
 491
 492 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
 493                 const struct tls_context *tls_ctx)
 494 {
 495         return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
 496 }
 497
 498 static inline struct tls_offload_context_tx *
 499 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
 500 {
 501         return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
 502 }
 503
 504 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
 505 {
 506         struct tls_context *ctx = tls_get_ctx(sk);
 507
 508         if (!ctx)
 509                 return false;
 510         return !!tls_sw_ctx_tx(ctx);
 511 }
 512
 513 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
 514 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
 515
 516 static inline struct tls_offload_context_rx *
 517 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
 518 {
 519         return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
 520 }
 521
 522 /* The TLS context is valid until sk_destruct is called */
 523 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
 524 {
 525         struct tls_context *tls_ctx = tls_get_ctx(sk);
 526         struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 527
 528         atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
 529 }
 530
 531
 532 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 533                       unsigned char *record_type);
 534 void tls_register_device(struct tls_device *device);
 535 void tls_unregister_device(struct tls_device *device);
 536 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
 537 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
 538                 struct scatterlist *sgout);
 539
 540 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
 541                                       struct net_device *dev,
 542                                       struct sk_buff *skb);
 543
 544 int tls_sw_fallback_init(struct sock *sk,
 545                          struct tls_offload_context_tx *offload_ctx,
 546                          struct tls_crypto_info *crypto_info);
 547
 548 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
 549
 550 void tls_device_offload_cleanup_rx(struct sock *sk);
 551 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
 552
 553 #endif /* _TLS_OFFLOAD_H */