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 aad_space[TLS_AAD_SPACE_SIZE];
 123         u8 iv_data[TLS_CIPHER_AES_GCM_128_IV_SIZE +
 124                    TLS_CIPHER_AES_GCM_128_SALT_SIZE];
 125         struct aead_request aead_req;
 126         u8 aead_req_ctx[];
 127 };
 128
 129 struct tx_work {
 130         struct delayed_work work;
 131         struct sock *sk;
 132 };
 133
 134 struct tls_sw_context_tx {
 135         struct crypto_aead *aead_send;
 136         struct crypto_wait async_wait;
 137         struct tx_work tx_work;
 138         struct tls_rec *open_rec;
 139         struct list_head tx_list;
 140         atomic_t encrypt_pending;
 141         int async_notify;
 142
 143 #define BIT_TX_SCHEDULED        0
 144         unsigned long tx_bitmask;
 145 };
 146
 147 struct tls_sw_context_rx {
 148         struct crypto_aead *aead_recv;
 149         struct crypto_wait async_wait;
 150
 151         struct strparser strp;
 152         void (*saved_data_ready)(struct sock *sk);
 153
 154         struct sk_buff *recv_pkt;
 155         u8 control;
 156         bool decrypted;
 157         atomic_t decrypt_pending;
 158         bool async_notify;
 159 };
 160
 161 struct tls_record_info {
 162         struct list_head list;
 163         u32 end_seq;
 164         int len;
 165         int num_frags;
 166         skb_frag_t frags[MAX_SKB_FRAGS];
 167 };
 168
 169 struct tls_offload_context_tx {
 170         struct crypto_aead *aead_send;
 171         spinlock_t lock;        /* protects records list */
 172         struct list_head records_list;
 173         struct tls_record_info *open_record;
 174         struct tls_record_info *retransmit_hint;
 175         u64 hint_record_sn;
 176         u64 unacked_record_sn;
 177
 178         struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
 179         void (*sk_destruct)(struct sock *sk);
 180         u8 driver_state[];
 181         /* The TLS layer reserves room for driver specific state
 182          * Currently the belief is that there is not enough
 183          * driver specific state to justify another layer of indirection
 184          */
 185 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
 186 };
 187
 188 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
 189         (ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
 190          TLS_DRIVER_STATE_SIZE)
 191
 192 enum {
 193         TLS_PENDING_CLOSED_RECORD
 194 };
 195
 196 struct cipher_context {
 197         u16 prepend_size;
 198         u16 tag_size;
 199         u16 overhead_size;
 200         u16 iv_size;
 201         char *iv;
 202         u16 rec_seq_size;
 203         char *rec_seq;
 204 };
 205
 206 union tls_crypto_context {
 207         struct tls_crypto_info info;
 208         struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
 209 };
 210
 211 struct tls_context {
 212         union tls_crypto_context crypto_send;
 213         union tls_crypto_context crypto_recv;
 214
 215         struct list_head list;
 216         struct net_device *netdev;
 217         refcount_t refcount;
 218
 219         void *priv_ctx_tx;
 220         void *priv_ctx_rx;
 221
 222         u8 tx_conf:3;
 223         u8 rx_conf:3;
 224
 225         struct cipher_context tx;
 226         struct cipher_context rx;
 227
 228         struct scatterlist *partially_sent_record;
 229         u16 partially_sent_offset;
 230
 231         unsigned long flags;
 232         bool in_tcp_sendpages;
 233         bool pending_open_record_frags;
 234
 235         int (*push_pending_record)(struct sock *sk, int flags);
 236
 237         void (*sk_write_space)(struct sock *sk);
 238         void (*sk_destruct)(struct sock *sk);
 239         void (*sk_proto_close)(struct sock *sk, long timeout);
 240
 241         int  (*setsockopt)(struct sock *sk, int level,
 242                            int optname, char __user *optval,
 243                            unsigned int optlen);
 244         int  (*getsockopt)(struct sock *sk, int level,
 245                            int optname, char __user *optval,
 246                            int __user *optlen);
 247         int  (*hash)(struct sock *sk);
 248         void (*unhash)(struct sock *sk);
 249 };
 250
 251 struct tls_offload_context_rx {
 252         /* sw must be the first member of tls_offload_context_rx */
 253         struct tls_sw_context_rx sw;
 254         atomic64_t resync_req;
 255         u8 driver_state[];
 256         /* The TLS layer reserves room for driver specific state
 257          * Currently the belief is that there is not enough
 258          * driver specific state to justify another layer of indirection
 259          */
 260 };
 261
 262 #define TLS_OFFLOAD_CONTEXT_SIZE_RX                                     \
 263         (ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
 264          TLS_DRIVER_STATE_SIZE)
 265
 266 int wait_on_pending_writer(struct sock *sk, long *timeo);
 267 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 268                 int __user *optlen);
 269 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 270                   unsigned int optlen);
 271
 272 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
 273 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 274 int tls_sw_sendpage(struct sock *sk, struct page *page,
 275                     int offset, size_t size, int flags);
 276 void tls_sw_close(struct sock *sk, long timeout);
 277 void tls_sw_free_resources_tx(struct sock *sk);
 278 void tls_sw_free_resources_rx(struct sock *sk);
 279 void tls_sw_release_resources_rx(struct sock *sk);
 280 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 281                    int nonblock, int flags, int *addr_len);
 282 bool tls_sw_stream_read(const struct sock *sk);
 283 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
 284                            struct pipe_inode_info *pipe,
 285                            size_t len, unsigned int flags);
 286
 287 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
 288 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 289 int tls_device_sendpage(struct sock *sk, struct page *page,
 290                         int offset, size_t size, int flags);
 291 void tls_device_sk_destruct(struct sock *sk);
 292 void tls_device_init(void);
 293 void tls_device_cleanup(void);
 294 int tls_tx_records(struct sock *sk, int flags);
 295
 296 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 297                                        u32 seq, u64 *p_record_sn);
 298
 299 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
 300 {
 301         return rec->len == 0;
 302 }
 303
 304 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
 305 {
 306         return rec->end_seq - rec->len;
 307 }
 308
 309 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 310 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 311                 struct scatterlist *sg, u16 first_offset,
 312                 int flags);
 313 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
 314                             int flags);
 315
 316 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
 317                                    int flags, long *timeo);
 318
 319 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
 320 {
 321         return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 322 }
 323
 324 static inline int tls_complete_pending_work(struct sock *sk,
 325                                             struct tls_context *ctx,
 326                                             int flags, long *timeo)
 327 {
 328         int rc = 0;
 329
 330         if (unlikely(sk->sk_write_pending))
 331                 rc = wait_on_pending_writer(sk, timeo);
 332
 333         if (!rc && tls_is_pending_closed_record(ctx))
 334                 rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
 335
 336         return rc;
 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 bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 345 {
 346         return tls_ctx->pending_open_record_frags;
 347 }
 348
 349 static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
 350 {
 351         struct tls_rec *rec;
 352
 353         rec = list_first_entry(&ctx->tx_list, struct tls_rec, list);
 354         if (!rec)
 355                 return false;
 356
 357         return READ_ONCE(rec->tx_ready);
 358 }
 359
 360 struct sk_buff *
 361 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
 362                       struct sk_buff *skb);
 363
 364 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
 365 {
 366 #ifdef CONFIG_SOCK_VALIDATE_XMIT
 367         return sk_fullsock(sk) &
 368                (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
 369                &tls_validate_xmit_skb);
 370 #else
 371         return false;
 372 #endif
 373 }
 374
 375 static inline void tls_err_abort(struct sock *sk, int err)
 376 {
 377         sk->sk_err = err;
 378         sk->sk_error_report(sk);
 379 }
 380
 381 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 382 {
 383         int i;
 384
 385         for (i = len - 1; i >= 0; i--) {
 386                 ++seq[i];
 387                 if (seq[i] != 0)
 388                         break;
 389         }
 390
 391         return (i == -1);
 392 }
 393
 394 static inline void tls_advance_record_sn(struct sock *sk,
 395                                          struct cipher_context *ctx)
 396 {
 397         if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
 398                 tls_err_abort(sk, EBADMSG);
 399         tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 400                              ctx->iv_size);
 401 }
 402
 403 static inline void tls_fill_prepend(struct tls_context *ctx,
 404                              char *buf,
 405                              size_t plaintext_len,
 406                              unsigned char record_type)
 407 {
 408         size_t pkt_len, iv_size = ctx->tx.iv_size;
 409
 410         pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
 411
 412         /* we cover nonce explicit here as well, so buf should be of
 413          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 414          */
 415         buf[0] = record_type;
 416         buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.info.version);
 417         buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.info.version);
 418         /* we can use IV for nonce explicit according to spec */
 419         buf[3] = pkt_len >> 8;
 420         buf[4] = pkt_len & 0xFF;
 421         memcpy(buf + TLS_NONCE_OFFSET,
 422                ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 423 }
 424
 425 static inline void tls_make_aad(char *buf,
 426                                 size_t size,
 427                                 char *record_sequence,
 428                                 int record_sequence_size,
 429                                 unsigned char record_type)
 430 {
 431         memcpy(buf, record_sequence, record_sequence_size);
 432
 433         buf[8] = record_type;
 434         buf[9] = TLS_1_2_VERSION_MAJOR;
 435         buf[10] = TLS_1_2_VERSION_MINOR;
 436         buf[11] = size >> 8;
 437         buf[12] = size & 0xFF;
 438 }
 439
 440 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 441 {
 442         struct inet_connection_sock *icsk = inet_csk(sk);
 443
 444         return icsk->icsk_ulp_data;
 445 }
 446
 447 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 448                 const struct tls_context *tls_ctx)
 449 {
 450         return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
 451 }
 452
 453 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
 454                 const struct tls_context *tls_ctx)
 455 {
 456         return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
 457 }
 458
 459 static inline struct tls_offload_context_tx *
 460 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
 461 {
 462         return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
 463 }
 464
 465 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
 466 {
 467         struct tls_context *ctx = tls_get_ctx(sk);
 468
 469         if (!ctx)
 470                 return false;
 471         return !!tls_sw_ctx_tx(ctx);
 472 }
 473
 474 static inline struct tls_offload_context_rx *
 475 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
 476 {
 477         return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
 478 }
 479
 480 /* The TLS context is valid until sk_destruct is called */
 481 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
 482 {
 483         struct tls_context *tls_ctx = tls_get_ctx(sk);
 484         struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 485
 486         atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
 487 }
 488
 489
 490 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 491                       unsigned char *record_type);
 492 void tls_register_device(struct tls_device *device);
 493 void tls_unregister_device(struct tls_device *device);
 494 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
 495 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
 496                 struct scatterlist *sgout);
 497
 498 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
 499                                       struct net_device *dev,
 500                                       struct sk_buff *skb);
 501
 502 int tls_sw_fallback_init(struct sock *sk,
 503                          struct tls_offload_context_tx *offload_ctx,
 504                          struct tls_crypto_info *crypto_info);
 505
 506 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
 507
 508 void tls_device_offload_cleanup_rx(struct sock *sk);
 509 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
 510
 511 #endif /* _TLS_OFFLOAD_H */