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 <net/tcp.h>
  43 #include <net/strparser.h>
  44
  45 #include <uapi/linux/tls.h>
  46
  47
  48 /* Maximum data size carried in a TLS record */
  49 #define TLS_MAX_PAYLOAD_SIZE            ((size_t)1 << 14)
  50
  51 #define TLS_HEADER_SIZE                 5
  52 #define TLS_NONCE_OFFSET                TLS_HEADER_SIZE
  53
  54 #define TLS_CRYPTO_INFO_READY(info)     ((info)->cipher_type)
  55
  56 #define TLS_RECORD_TYPE_DATA            0x17
  57
  58 #define TLS_AAD_SPACE_SIZE              13
  59 #define TLS_DEVICE_NAME_MAX             32
  60
  61 /*
  62  * This structure defines the routines for Inline TLS driver.
  63  * The following routines are optional and filled with a
  64  * null pointer if not defined.
  65  *
  66  * @name: Its the name of registered Inline tls device
  67  * @dev_list: Inline tls device list
  68  * int (*feature)(struct tls_device *device);
  69  *     Called to return Inline TLS driver capability
  70  *
  71  * int (*hash)(struct tls_device *device, struct sock *sk);
  72  *     This function sets Inline driver for listen and program
  73  *     device specific functioanlity as required
  74  *
  75  * void (*unhash)(struct tls_device *device, struct sock *sk);
  76  *     This function cleans listen state set by Inline TLS driver
  77  */
  78 struct tls_device {
  79         char name[TLS_DEVICE_NAME_MAX];
  80         struct list_head dev_list;
  81         int  (*feature)(struct tls_device *device);
  82         int  (*hash)(struct tls_device *device, struct sock *sk);
  83         void (*unhash)(struct tls_device *device, struct sock *sk);
  84 };
  85
  86 enum {
  87         TLS_BASE,
  88         TLS_SW,
  89 #ifdef CONFIG_TLS_DEVICE
  90         TLS_HW,
  91 #endif
  92         TLS_HW_RECORD,
  93         TLS_NUM_CONFIG,
  94 };
  95
  96 struct tls_sw_context_tx {
  97         struct crypto_aead *aead_send;
  98         struct crypto_wait async_wait;
  99
 100         char aad_space[TLS_AAD_SPACE_SIZE];
 101
 102         unsigned int sg_plaintext_size;
 103         int sg_plaintext_num_elem;
 104         struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
 105
 106         unsigned int sg_encrypted_size;
 107         int sg_encrypted_num_elem;
 108         struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
 109
 110         /* AAD | sg_plaintext_data | sg_tag */
 111         struct scatterlist sg_aead_in[2];
 112         /* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
 113         struct scatterlist sg_aead_out[2];
 114 };
 115
 116 struct tls_sw_context_rx {
 117         struct crypto_aead *aead_recv;
 118         struct crypto_wait async_wait;
 119
 120         struct strparser strp;
 121         void (*saved_data_ready)(struct sock *sk);
 122         unsigned int (*sk_poll)(struct file *file, struct socket *sock,
 123                                 struct poll_table_struct *wait);
 124         struct sk_buff *recv_pkt;
 125         u8 control;
 126         bool decrypted;
 127 };
 128
 129 struct tls_record_info {
 130         struct list_head list;
 131         u32 end_seq;
 132         int len;
 133         int num_frags;
 134         skb_frag_t frags[MAX_SKB_FRAGS];
 135 };
 136
 137 struct tls_offload_context_tx {
 138         struct crypto_aead *aead_send;
 139         spinlock_t lock;        /* protects records list */
 140         struct list_head records_list;
 141         struct tls_record_info *open_record;
 142         struct tls_record_info *retransmit_hint;
 143         u64 hint_record_sn;
 144         u64 unacked_record_sn;
 145
 146         struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
 147         void (*sk_destruct)(struct sock *sk);
 148         u8 driver_state[];
 149         /* The TLS layer reserves room for driver specific state
 150          * Currently the belief is that there is not enough
 151          * driver specific state to justify another layer of indirection
 152          */
 153 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
 154 };
 155
 156 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
 157         (ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
 158          TLS_DRIVER_STATE_SIZE)
 159
 160 enum {
 161         TLS_PENDING_CLOSED_RECORD
 162 };
 163
 164 struct cipher_context {
 165         u16 prepend_size;
 166         u16 tag_size;
 167         u16 overhead_size;
 168         u16 iv_size;
 169         char *iv;
 170         u16 rec_seq_size;
 171         char *rec_seq;
 172 };
 173
 174 struct tls_context {
 175         union {
 176                 struct tls_crypto_info crypto_send;
 177                 struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
 178         };
 179         union {
 180                 struct tls_crypto_info crypto_recv;
 181                 struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
 182         };
 183
 184         struct list_head list;
 185         struct net_device *netdev;
 186         refcount_t refcount;
 187
 188         void *priv_ctx_tx;
 189         void *priv_ctx_rx;
 190
 191         u8 tx_conf:3;
 192         u8 rx_conf:3;
 193
 194         struct cipher_context tx;
 195         struct cipher_context rx;
 196
 197         struct scatterlist *partially_sent_record;
 198         u16 partially_sent_offset;
 199         unsigned long flags;
 200         bool in_tcp_sendpages;
 201
 202         u16 pending_open_record_frags;
 203         int (*push_pending_record)(struct sock *sk, int flags);
 204
 205         void (*sk_write_space)(struct sock *sk);
 206         void (*sk_destruct)(struct sock *sk);
 207         void (*sk_proto_close)(struct sock *sk, long timeout);
 208
 209         int  (*setsockopt)(struct sock *sk, int level,
 210                            int optname, char __user *optval,
 211                            unsigned int optlen);
 212         int  (*getsockopt)(struct sock *sk, int level,
 213                            int optname, char __user *optval,
 214                            int __user *optlen);
 215         int  (*hash)(struct sock *sk);
 216         void (*unhash)(struct sock *sk);
 217 };
 218
 219 struct tls_offload_context_rx {
 220         /* sw must be the first member of tls_offload_context_rx */
 221         struct tls_sw_context_rx sw;
 222         atomic64_t resync_req;
 223         u8 driver_state[];
 224         /* The TLS layer reserves room for driver specific state
 225          * Currently the belief is that there is not enough
 226          * driver specific state to justify another layer of indirection
 227          */
 228 };
 229
 230 #define TLS_OFFLOAD_CONTEXT_SIZE_RX                                     \
 231         (ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
 232          TLS_DRIVER_STATE_SIZE)
 233
 234 int wait_on_pending_writer(struct sock *sk, long *timeo);
 235 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 236                 int __user *optlen);
 237 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 238                   unsigned int optlen);
 239
 240 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
 241 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 242 int tls_sw_sendpage(struct sock *sk, struct page *page,
 243                     int offset, size_t size, int flags);
 244 void tls_sw_close(struct sock *sk, long timeout);
 245 void tls_sw_free_resources_tx(struct sock *sk);
 246 void tls_sw_free_resources_rx(struct sock *sk);
 247 void tls_sw_release_resources_rx(struct sock *sk);
 248 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 249                    int nonblock, int flags, int *addr_len);
 250 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
 251                          struct poll_table_struct *wait);
 252 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
 253                            struct pipe_inode_info *pipe,
 254                            size_t len, unsigned int flags);
 255
 256 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
 257 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 258 int tls_device_sendpage(struct sock *sk, struct page *page,
 259                         int offset, size_t size, int flags);
 260 void tls_device_sk_destruct(struct sock *sk);
 261 void tls_device_init(void);
 262 void tls_device_cleanup(void);
 263
 264 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 265                                        u32 seq, u64 *p_record_sn);
 266
 267 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
 268 {
 269         return rec->len == 0;
 270 }
 271
 272 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
 273 {
 274         return rec->end_seq - rec->len;
 275 }
 276
 277 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 278 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 279                 struct scatterlist *sg, u16 first_offset,
 280                 int flags);
 281 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
 282                                    int flags, long *timeo);
 283
 284 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
 285 {
 286         return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 287 }
 288
 289 static inline int tls_complete_pending_work(struct sock *sk,
 290                                             struct tls_context *ctx,
 291                                             int flags, long *timeo)
 292 {
 293         int rc = 0;
 294
 295         if (unlikely(sk->sk_write_pending))
 296                 rc = wait_on_pending_writer(sk, timeo);
 297
 298         if (!rc && tls_is_pending_closed_record(ctx))
 299                 rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
 300
 301         return rc;
 302 }
 303
 304 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 305 {
 306         return !!ctx->partially_sent_record;
 307 }
 308
 309 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 310 {
 311         return tls_ctx->pending_open_record_frags;
 312 }
 313
 314 struct sk_buff *
 315 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
 316                       struct sk_buff *skb);
 317
 318 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
 319 {
 320 #ifdef CONFIG_SOCK_VALIDATE_XMIT
 321         return sk_fullsock(sk) &
 322                (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
 323                &tls_validate_xmit_skb);
 324 #else
 325         return false;
 326 #endif
 327 }
 328
 329 static inline void tls_err_abort(struct sock *sk, int err)
 330 {
 331         sk->sk_err = err;
 332         sk->sk_error_report(sk);
 333 }
 334
 335 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 336 {
 337         int i;
 338
 339         for (i = len - 1; i >= 0; i--) {
 340                 ++seq[i];
 341                 if (seq[i] != 0)
 342                         break;
 343         }
 344
 345         return (i == -1);
 346 }
 347
 348 static inline void tls_advance_record_sn(struct sock *sk,
 349                                          struct cipher_context *ctx)
 350 {
 351         if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
 352                 tls_err_abort(sk, EBADMSG);
 353         tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 354                              ctx->iv_size);
 355 }
 356
 357 static inline void tls_fill_prepend(struct tls_context *ctx,
 358                              char *buf,
 359                              size_t plaintext_len,
 360                              unsigned char record_type)
 361 {
 362         size_t pkt_len, iv_size = ctx->tx.iv_size;
 363
 364         pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
 365
 366         /* we cover nonce explicit here as well, so buf should be of
 367          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 368          */
 369         buf[0] = record_type;
 370         buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
 371         buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
 372         /* we can use IV for nonce explicit according to spec */
 373         buf[3] = pkt_len >> 8;
 374         buf[4] = pkt_len & 0xFF;
 375         memcpy(buf + TLS_NONCE_OFFSET,
 376                ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 377 }
 378
 379 static inline void tls_make_aad(char *buf,
 380                                 size_t size,
 381                                 char *record_sequence,
 382                                 int record_sequence_size,
 383                                 unsigned char record_type)
 384 {
 385         memcpy(buf, record_sequence, record_sequence_size);
 386
 387         buf[8] = record_type;
 388         buf[9] = TLS_1_2_VERSION_MAJOR;
 389         buf[10] = TLS_1_2_VERSION_MINOR;
 390         buf[11] = size >> 8;
 391         buf[12] = size & 0xFF;
 392 }
 393
 394 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 395 {
 396         struct inet_connection_sock *icsk = inet_csk(sk);
 397
 398         return icsk->icsk_ulp_data;
 399 }
 400
 401 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 402                 const struct tls_context *tls_ctx)
 403 {
 404         return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
 405 }
 406
 407 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
 408                 const struct tls_context *tls_ctx)
 409 {
 410         return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
 411 }
 412
 413 static inline struct tls_offload_context_tx *
 414 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
 415 {
 416         return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
 417 }
 418
 419 static inline struct tls_offload_context_rx *
 420 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
 421 {
 422         return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
 423 }
 424
 425 /* The TLS context is valid until sk_destruct is called */
 426 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
 427 {
 428         struct tls_context *tls_ctx = tls_get_ctx(sk);
 429         struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 430
 431         atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
 432 }
 433
 434
 435 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 436                       unsigned char *record_type);
 437 void tls_register_device(struct tls_device *device);
 438 void tls_unregister_device(struct tls_device *device);
 439 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
 440 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
 441                 struct scatterlist *sgout);
 442
 443 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
 444                                       struct net_device *dev,
 445                                       struct sk_buff *skb);
 446
 447 int tls_sw_fallback_init(struct sock *sk,
 448                          struct tls_offload_context_tx *offload_ctx,
 449                          struct tls_crypto_info *crypto_info);
 450
 451 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
 452
 453 void tls_device_offload_cleanup_rx(struct sock *sk);
 454 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
 455
 456 #endif /* _TLS_OFFLOAD_H */