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 struct tls_cipher_size_desc {
55 unsigned int iv;
56 unsigned int key;
57 unsigned int salt;
58 unsigned int tag;
59 unsigned int rec_seq;
60 };
61
62 extern const struct tls_cipher_size_desc tls_cipher_size_desc[];
63
64 /* Maximum data size carried in a TLS record */
65 #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
66
67 #define TLS_HEADER_SIZE 5
68 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE
69
70 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
71
72 #define TLS_RECORD_TYPE_DATA 0x17
73
74 #define TLS_AAD_SPACE_SIZE 13
75
76 #define MAX_IV_SIZE 16
77 #define TLS_TAG_SIZE 16
78 #define TLS_MAX_REC_SEQ_SIZE 8
79 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE
80
81 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
82 *
83 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3]
84 *
85 * The field 'length' is encoded in field 'b0' as '(length width - 1)'.
86 * Hence b0 contains (3 - 1) = 2.
87 */
88 #define TLS_AES_CCM_IV_B0_BYTE 2
89 #define TLS_SM4_CCM_IV_B0_BYTE 2
90
91 enum {
92 TLS_BASE,
93 TLS_SW,
94 TLS_HW,
95 TLS_HW_RECORD,
96 TLS_NUM_CONFIG,
97 };
98
99 struct tx_work {
100 struct delayed_work work;
101 struct sock *sk;
102 };
103
104 struct tls_sw_context_tx {
105 struct crypto_aead *aead_send;
106 struct crypto_wait async_wait;
107 struct tx_work tx_work;
108 struct tls_rec *open_rec;
109 struct list_head tx_list;
110 atomic_t encrypt_pending;
111 /* protect crypto_wait with encrypt_pending */
112 spinlock_t encrypt_compl_lock;
113 int async_notify;
114 u8 async_capable:1;
115
116 #define BIT_TX_SCHEDULED 0
117 #define BIT_TX_CLOSING 1
118 unsigned long tx_bitmask;
119 };
120
121 struct tls_strparser {
122 struct sock *sk;
123
124 u32 mark : 8;
125 u32 stopped : 1;
126 u32 copy_mode : 1;
127 u32 msg_ready : 1;
128
129 struct strp_msg stm;
130
131 struct sk_buff *anchor;
132 struct work_struct work;
133 };
134
135 struct tls_sw_context_rx {
136 struct crypto_aead *aead_recv;
137 struct crypto_wait async_wait;
138 struct sk_buff_head rx_list; /* list of decrypted 'data' records */
139 void (*saved_data_ready)(struct sock *sk);
140
141 u8 reader_present;
142 u8 async_capable:1;
143 u8 zc_capable:1;
144 u8 reader_contended:1;
145
146 struct tls_strparser strp;
147
148 atomic_t decrypt_pending;
149 /* protect crypto_wait with decrypt_pending*/
150 spinlock_t decrypt_compl_lock;
151 struct sk_buff_head async_hold;
152 struct wait_queue_head wq;
153 };
154
155 struct tls_record_info {
156 struct list_head list;
157 u32 end_seq;
158 int len;
159 int num_frags;
160 skb_frag_t frags[MAX_SKB_FRAGS];
161 };
162
163 struct tls_offload_context_tx {
164 struct crypto_aead *aead_send;
165 spinlock_t lock; /* protects records list */
166 struct list_head records_list;
167 struct tls_record_info *open_record;
168 struct tls_record_info *retransmit_hint;
169 u64 hint_record_sn;
170 u64 unacked_record_sn;
171
172 struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
173 void (*sk_destruct)(struct sock *sk);
174 struct work_struct destruct_work;
175 struct tls_context *ctx;
176 u8 driver_state[] __aligned(8);
177 /* The TLS layer reserves room for driver specific state
178 * Currently the belief is that there is not enough
179 * driver specific state to justify another layer of indirection
180 */
181 #define TLS_DRIVER_STATE_SIZE_TX 16
182 };
183
184 #define TLS_OFFLOAD_CONTEXT_SIZE_TX \
185 (sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX)
186
187 enum tls_context_flags {
188 /* tls_device_down was called after the netdev went down, device state
189 * was released, and kTLS works in software, even though rx_conf is
190 * still TLS_HW (needed for transition).
191 */
192 TLS_RX_DEV_DEGRADED = 0,
193 /* Unlike RX where resync is driven entirely by the core in TX only
194 * the driver knows when things went out of sync, so we need the flag
195 * to be atomic.
196 */
197 TLS_TX_SYNC_SCHED = 1,
198 /* tls_dev_del was called for the RX side, device state was released,
199 * but tls_ctx->netdev might still be kept, because TX-side driver
200 * resources might not be released yet. Used to prevent the second
201 * tls_dev_del call in tls_device_down if it happens simultaneously.
202 */
203 TLS_RX_DEV_CLOSED = 2,
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 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305;
217 struct tls12_crypto_info_sm4_gcm sm4_gcm;
218 struct tls12_crypto_info_sm4_ccm sm4_ccm;
219 };
220 };
221
222 struct tls_prot_info {
223 u16 version;
224 u16 cipher_type;
225 u16 prepend_size;
226 u16 tag_size;
227 u16 overhead_size;
228 u16 iv_size;
229 u16 salt_size;
230 u16 rec_seq_size;
231 u16 aad_size;
232 u16 tail_size;
233 };
234
235 struct tls_context {
236 /* read-only cache line */
237 struct tls_prot_info prot_info;
238
239 u8 tx_conf:3;
240 u8 rx_conf:3;
241 u8 zerocopy_sendfile:1;
242 u8 rx_no_pad:1;
243
244 int (*push_pending_record)(struct sock *sk, int flags);
245 void (*sk_write_space)(struct sock *sk);
246
247 void *priv_ctx_tx;
248 void *priv_ctx_rx;
249
250 struct net_device __rcu *netdev;
251
252 /* rw cache line */
253 struct cipher_context tx;
254 struct cipher_context rx;
255
256 struct scatterlist *partially_sent_record;
257 u16 partially_sent_offset;
258
259 bool in_tcp_sendpages;
260 bool pending_open_record_frags;
261
262 struct mutex tx_lock; /* protects partially_sent_* fields and
263 * per-type TX fields
264 */
265 unsigned long flags;
266
267 /* cache cold stuff */
268 struct proto *sk_proto;
269 struct sock *sk;
270
271 void (*sk_destruct)(struct sock *sk);
272
273 union tls_crypto_context crypto_send;
274 union tls_crypto_context crypto_recv;
275
276 struct list_head list;
277 refcount_t refcount;
278 struct rcu_head rcu;
279 };
280
281 enum tls_offload_ctx_dir {
282 TLS_OFFLOAD_CTX_DIR_RX,
283 TLS_OFFLOAD_CTX_DIR_TX,
284 };
285
286 struct tlsdev_ops {
287 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk,
288 enum tls_offload_ctx_dir direction,
289 struct tls_crypto_info *crypto_info,
290 u32 start_offload_tcp_sn);
291 void (*tls_dev_del)(struct net_device *netdev,
292 struct tls_context *ctx,
293 enum tls_offload_ctx_dir direction);
294 int (*tls_dev_resync)(struct net_device *netdev,
295 struct sock *sk, u32 seq, u8 *rcd_sn,
296 enum tls_offload_ctx_dir direction);
297 };
298
299 enum tls_offload_sync_type {
300 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0,
301 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1,
302 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2,
303 };
304
305 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2
306 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
307
308 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13
309 struct tls_offload_resync_async {
310 atomic64_t req;
311 u16 loglen;
312 u16 rcd_delta;
313 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX];
314 };
315
316 struct tls_offload_context_rx {
317 /* sw must be the first member of tls_offload_context_rx */
318 struct tls_sw_context_rx sw;
319 enum tls_offload_sync_type resync_type;
320 /* this member is set regardless of resync_type, to avoid branches */
321 u8 resync_nh_reset:1;
322 /* CORE_NEXT_HINT-only member, but use the hole here */
323 u8 resync_nh_do_now:1;
324 union {
325 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */
326 struct {
327 atomic64_t resync_req;
328 };
329 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */
330 struct {
331 u32 decrypted_failed;
332 u32 decrypted_tgt;
333 } resync_nh;
334 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */
335 struct {
336 struct tls_offload_resync_async *resync_async;
337 };
338 };
339 u8 driver_state[] __aligned(8);
340 /* The TLS layer reserves room for driver specific state
341 * Currently the belief is that there is not enough
342 * driver specific state to justify another layer of indirection
343 */
344 #define TLS_DRIVER_STATE_SIZE_RX 8
345 };
346
347 #define TLS_OFFLOAD_CONTEXT_SIZE_RX \
348 (sizeof(struct tls_offload_context_rx) + TLS_DRIVER_STATE_SIZE_RX)
349
350 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
351 u32 seq, u64 *p_record_sn);
352
tls_record_is_start_marker(struct tls_record_info * rec)353 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
354 {
355 return rec->len == 0;
356 }
357
tls_record_start_seq(struct tls_record_info * rec)358 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
359 {
360 return rec->end_seq - rec->len;
361 }
362
363 struct sk_buff *
364 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
365 struct sk_buff *skb);
366 struct sk_buff *
367 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev,
368 struct sk_buff *skb);
369
tls_is_sk_tx_device_offloaded(struct sock * sk)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
tls_get_ctx(const struct sock * sk)381 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
382 {
383 struct inet_connection_sock *icsk = inet_csk(sk);
384
385 /* Use RCU on icsk_ulp_data only for sock diag code,
386 * TLS data path doesn't need rcu_dereference().
387 */
388 return (__force void *)icsk->icsk_ulp_data;
389 }
390
tls_sw_ctx_rx(const struct tls_context * tls_ctx)391 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
392 const struct tls_context *tls_ctx)
393 {
394 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
395 }
396
tls_sw_ctx_tx(const struct tls_context * tls_ctx)397 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
398 const struct tls_context *tls_ctx)
399 {
400 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
401 }
402
403 static inline struct tls_offload_context_tx *
tls_offload_ctx_tx(const struct tls_context * tls_ctx)404 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
405 {
406 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
407 }
408
tls_sw_has_ctx_tx(const struct sock * sk)409 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
410 {
411 struct tls_context *ctx = tls_get_ctx(sk);
412
413 if (!ctx)
414 return false;
415 return !!tls_sw_ctx_tx(ctx);
416 }
417
tls_sw_has_ctx_rx(const struct sock * sk)418 static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
419 {
420 struct tls_context *ctx = tls_get_ctx(sk);
421
422 if (!ctx)
423 return false;
424 return !!tls_sw_ctx_rx(ctx);
425 }
426
427 static inline struct tls_offload_context_rx *
tls_offload_ctx_rx(const struct tls_context * tls_ctx)428 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
429 {
430 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
431 }
432
__tls_driver_ctx(struct tls_context * tls_ctx,enum tls_offload_ctx_dir direction)433 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx,
434 enum tls_offload_ctx_dir direction)
435 {
436 if (direction == TLS_OFFLOAD_CTX_DIR_TX)
437 return tls_offload_ctx_tx(tls_ctx)->driver_state;
438 else
439 return tls_offload_ctx_rx(tls_ctx)->driver_state;
440 }
441
442 static inline void *
tls_driver_ctx(const struct sock * sk,enum tls_offload_ctx_dir direction)443 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction)
444 {
445 return __tls_driver_ctx(tls_get_ctx(sk), direction);
446 }
447
448 #define RESYNC_REQ BIT(0)
449 #define RESYNC_REQ_ASYNC BIT(1)
450 /* The TLS context is valid until sk_destruct is called */
tls_offload_rx_resync_request(struct sock * sk,__be32 seq)451 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
452 {
453 struct tls_context *tls_ctx = tls_get_ctx(sk);
454 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
455
456 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ);
457 }
458
459 /* Log all TLS record header TCP sequences in [seq, seq+len] */
460 static inline void
tls_offload_rx_resync_async_request_start(struct sock * sk,__be32 seq,u16 len)461 tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
462 {
463 struct tls_context *tls_ctx = tls_get_ctx(sk);
464 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
465
466 atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
467 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
468 rx_ctx->resync_async->loglen = 0;
469 rx_ctx->resync_async->rcd_delta = 0;
470 }
471
472 static inline void
tls_offload_rx_resync_async_request_end(struct sock * sk,__be32 seq)473 tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq)
474 {
475 struct tls_context *tls_ctx = tls_get_ctx(sk);
476 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
477
478 atomic64_set(&rx_ctx->resync_async->req,
479 ((u64)ntohl(seq) << 32) | RESYNC_REQ);
480 }
481
482 static inline void
tls_offload_rx_resync_set_type(struct sock * sk,enum tls_offload_sync_type type)483 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type)
484 {
485 struct tls_context *tls_ctx = tls_get_ctx(sk);
486
487 tls_offload_ctx_rx(tls_ctx)->resync_type = type;
488 }
489
490 /* Driver's seq tracking has to be disabled until resync succeeded */
tls_offload_tx_resync_pending(struct sock * sk)491 static inline bool tls_offload_tx_resync_pending(struct sock *sk)
492 {
493 struct tls_context *tls_ctx = tls_get_ctx(sk);
494 bool ret;
495
496 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
497 smp_mb__after_atomic();
498 return ret;
499 }
500
501 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
502
503 #ifdef CONFIG_TLS_DEVICE
504 void tls_device_sk_destruct(struct sock *sk);
505 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
506
tls_is_sk_rx_device_offloaded(struct sock * sk)507 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
508 {
509 if (!sk_fullsock(sk) ||
510 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct)
511 return false;
512 return tls_get_ctx(sk)->rx_conf == TLS_HW;
513 }
514 #endif
515 #endif /* _TLS_OFFLOAD_H */
516