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 /* Maximum data size carried in a TLS record */
55 #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
56
57 #define TLS_HEADER_SIZE 5
58 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE
59
60 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
61
62 #define TLS_AAD_SPACE_SIZE 13
63
64 #define TLS_MAX_IV_SIZE 16
65 #define TLS_MAX_SALT_SIZE 4
66 #define TLS_TAG_SIZE 16
67 #define TLS_MAX_REC_SEQ_SIZE 8
68 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE
69
70 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
71 *
72 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3]
73 *
74 * The field 'length' is encoded in field 'b0' as '(length width - 1)'.
75 * Hence b0 contains (3 - 1) = 2.
76 */
77 #define TLS_AES_CCM_IV_B0_BYTE 2
78 #define TLS_SM4_CCM_IV_B0_BYTE 2
79
80 enum {
81 TLS_BASE,
82 TLS_SW,
83 TLS_HW,
84 TLS_HW_RECORD,
85 TLS_NUM_CONFIG,
86 };
87
88 struct tx_work {
89 struct delayed_work work;
90 struct sock *sk;
91 };
92
93 struct tls_sw_context_tx {
94 struct crypto_aead *aead_send;
95 struct crypto_wait async_wait;
96 struct tx_work tx_work;
97 struct tls_rec *open_rec;
98 struct list_head tx_list;
99 atomic_t encrypt_pending;
100 u8 async_capable:1;
101
102 #define BIT_TX_SCHEDULED 0
103 #define BIT_TX_CLOSING 1
104 unsigned long tx_bitmask;
105 };
106
107 struct tls_strparser {
108 struct sock *sk;
109
110 u32 mark : 8;
111 u32 stopped : 1;
112 u32 copy_mode : 1;
113 u32 mixed_decrypted : 1;
114
115 bool msg_ready;
116
117 struct strp_msg stm;
118
119 struct sk_buff *anchor;
120 struct work_struct work;
121 };
122
123 struct tls_sw_context_rx {
124 struct crypto_aead *aead_recv;
125 struct crypto_wait async_wait;
126 struct sk_buff_head rx_list; /* list of decrypted 'data' records */
127 void (*saved_data_ready)(struct sock *sk);
128
129 u8 reader_present;
130 u8 async_capable:1;
131 u8 zc_capable:1;
132 u8 reader_contended:1;
133
134 struct tls_strparser strp;
135
136 atomic_t decrypt_pending;
137 struct sk_buff_head async_hold;
138 struct wait_queue_head wq;
139 };
140
141 struct tls_record_info {
142 struct list_head list;
143 u32 end_seq;
144 int len;
145 int num_frags;
146 skb_frag_t frags[MAX_SKB_FRAGS];
147 };
148
149 #define TLS_DRIVER_STATE_SIZE_TX 16
150 struct tls_offload_context_tx {
151 struct crypto_aead *aead_send;
152 spinlock_t lock; /* protects records list */
153 struct list_head records_list;
154 struct tls_record_info *open_record;
155 struct tls_record_info *retransmit_hint;
156 u64 hint_record_sn;
157 u64 unacked_record_sn;
158
159 struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
160 void (*sk_destruct)(struct sock *sk);
161 struct work_struct destruct_work;
162 struct tls_context *ctx;
163 /* The TLS layer reserves room for driver specific state
164 * Currently the belief is that there is not enough
165 * driver specific state to justify another layer of indirection
166 */
167 u8 driver_state[TLS_DRIVER_STATE_SIZE_TX] __aligned(8);
168 };
169
170 enum tls_context_flags {
171 /* tls_device_down was called after the netdev went down, device state
172 * was released, and kTLS works in software, even though rx_conf is
173 * still TLS_HW (needed for transition).
174 */
175 TLS_RX_DEV_DEGRADED = 0,
176 /* Unlike RX where resync is driven entirely by the core in TX only
177 * the driver knows when things went out of sync, so we need the flag
178 * to be atomic.
179 */
180 TLS_TX_SYNC_SCHED = 1,
181 /* tls_dev_del was called for the RX side, device state was released,
182 * but tls_ctx->netdev might still be kept, because TX-side driver
183 * resources might not be released yet. Used to prevent the second
184 * tls_dev_del call in tls_device_down if it happens simultaneously.
185 */
186 TLS_RX_DEV_CLOSED = 2,
187 };
188
189 struct cipher_context {
190 char iv[TLS_MAX_IV_SIZE + TLS_MAX_SALT_SIZE];
191 char rec_seq[TLS_MAX_REC_SEQ_SIZE];
192 };
193
194 union tls_crypto_context {
195 struct tls_crypto_info info;
196 union {
197 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
198 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
199 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305;
200 struct tls12_crypto_info_sm4_gcm sm4_gcm;
201 struct tls12_crypto_info_sm4_ccm sm4_ccm;
202 };
203 };
204
205 struct tls_prot_info {
206 u16 version;
207 u16 cipher_type;
208 u16 prepend_size;
209 u16 tag_size;
210 u16 overhead_size;
211 u16 iv_size;
212 u16 salt_size;
213 u16 rec_seq_size;
214 u16 aad_size;
215 u16 tail_size;
216 };
217
218 struct tls_context {
219 /* read-only cache line */
220 struct tls_prot_info prot_info;
221
222 u8 tx_conf:3;
223 u8 rx_conf:3;
224 u8 zerocopy_sendfile:1;
225 u8 rx_no_pad:1;
226
227 int (*push_pending_record)(struct sock *sk, int flags);
228 void (*sk_write_space)(struct sock *sk);
229
230 void *priv_ctx_tx;
231 void *priv_ctx_rx;
232
233 struct net_device __rcu *netdev;
234
235 /* rw cache line */
236 struct cipher_context tx;
237 struct cipher_context rx;
238
239 struct scatterlist *partially_sent_record;
240 u16 partially_sent_offset;
241
242 bool splicing_pages;
243 bool pending_open_record_frags;
244
245 struct mutex tx_lock; /* protects partially_sent_* fields and
246 * per-type TX fields
247 */
248 unsigned long flags;
249
250 /* cache cold stuff */
251 struct proto *sk_proto;
252 struct sock *sk;
253
254 void (*sk_destruct)(struct sock *sk);
255
256 union tls_crypto_context crypto_send;
257 union tls_crypto_context crypto_recv;
258
259 struct list_head list;
260 refcount_t refcount;
261 struct rcu_head rcu;
262 };
263
264 enum tls_offload_ctx_dir {
265 TLS_OFFLOAD_CTX_DIR_RX,
266 TLS_OFFLOAD_CTX_DIR_TX,
267 };
268
269 struct tlsdev_ops {
270 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk,
271 enum tls_offload_ctx_dir direction,
272 struct tls_crypto_info *crypto_info,
273 u32 start_offload_tcp_sn);
274 void (*tls_dev_del)(struct net_device *netdev,
275 struct tls_context *ctx,
276 enum tls_offload_ctx_dir direction);
277 int (*tls_dev_resync)(struct net_device *netdev,
278 struct sock *sk, u32 seq, u8 *rcd_sn,
279 enum tls_offload_ctx_dir direction);
280 };
281
282 enum tls_offload_sync_type {
283 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0,
284 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1,
285 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2,
286 };
287
288 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2
289 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
290
291 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13
292 struct tls_offload_resync_async {
293 atomic64_t req;
294 u16 loglen;
295 u16 rcd_delta;
296 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX];
297 };
298
299 #define TLS_DRIVER_STATE_SIZE_RX 8
300 struct tls_offload_context_rx {
301 /* sw must be the first member of tls_offload_context_rx */
302 struct tls_sw_context_rx sw;
303 enum tls_offload_sync_type resync_type;
304 /* this member is set regardless of resync_type, to avoid branches */
305 u8 resync_nh_reset:1;
306 /* CORE_NEXT_HINT-only member, but use the hole here */
307 u8 resync_nh_do_now:1;
308 union {
309 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */
310 struct {
311 atomic64_t resync_req;
312 };
313 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */
314 struct {
315 u32 decrypted_failed;
316 u32 decrypted_tgt;
317 } resync_nh;
318 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */
319 struct {
320 struct tls_offload_resync_async *resync_async;
321 };
322 };
323 /* The TLS layer reserves room for driver specific state
324 * Currently the belief is that there is not enough
325 * driver specific state to justify another layer of indirection
326 */
327 u8 driver_state[TLS_DRIVER_STATE_SIZE_RX] __aligned(8);
328 };
329
330 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
331 u32 seq, u64 *p_record_sn);
332
333 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
334 {
335 return rec->len == 0;
336 }
337
338 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
339 {
340 return rec->end_seq - rec->len;
341 }
342
343 struct sk_buff *
344 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
345 struct sk_buff *skb);
346 struct sk_buff *
347 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev,
348 struct sk_buff *skb);
349
350 static inline bool tls_is_skb_tx_device_offloaded(const struct sk_buff *skb)
351 {
352 #ifdef CONFIG_TLS_DEVICE
353 struct sock *sk = skb->sk;
354
355 return sk && sk_fullsock(sk) &&
356 (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
357 &tls_validate_xmit_skb);
358 #else
359 return false;
360 #endif
361 }
362
363 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
364 {
365 const struct inet_connection_sock *icsk = inet_csk(sk);
366
367 /* Use RCU on icsk_ulp_data only for sock diag code,
368 * TLS data path doesn't need rcu_dereference().
369 */
370 return (__force void *)icsk->icsk_ulp_data;
371 }
372
373 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
374 const struct tls_context *tls_ctx)
375 {
376 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
377 }
378
379 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
380 const struct tls_context *tls_ctx)
381 {
382 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
383 }
384
385 static inline struct tls_offload_context_tx *
386 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
387 {
388 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
389 }
390
391 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
392 {
393 struct tls_context *ctx = tls_get_ctx(sk);
394
395 if (!ctx)
396 return false;
397 return !!tls_sw_ctx_tx(ctx);
398 }
399
400 static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
401 {
402 struct tls_context *ctx = tls_get_ctx(sk);
403
404 if (!ctx)
405 return false;
406 return !!tls_sw_ctx_rx(ctx);
407 }
408
409 static inline struct tls_offload_context_rx *
410 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
411 {
412 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
413 }
414
415 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx,
416 enum tls_offload_ctx_dir direction)
417 {
418 if (direction == TLS_OFFLOAD_CTX_DIR_TX)
419 return tls_offload_ctx_tx(tls_ctx)->driver_state;
420 else
421 return tls_offload_ctx_rx(tls_ctx)->driver_state;
422 }
423
424 static inline void *
425 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction)
426 {
427 return __tls_driver_ctx(tls_get_ctx(sk), direction);
428 }
429
430 #define RESYNC_REQ BIT(0)
431 #define RESYNC_REQ_ASYNC BIT(1)
432 /* The TLS context is valid until sk_destruct is called */
433 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
434 {
435 struct tls_context *tls_ctx = tls_get_ctx(sk);
436 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
437
438 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ);
439 }
440
441 /* Log all TLS record header TCP sequences in [seq, seq+len] */
442 static inline void
443 tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
444 {
445 struct tls_context *tls_ctx = tls_get_ctx(sk);
446 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
447
448 atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
449 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
450 rx_ctx->resync_async->loglen = 0;
451 rx_ctx->resync_async->rcd_delta = 0;
452 }
453
454 static inline void
455 tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq)
456 {
457 struct tls_context *tls_ctx = tls_get_ctx(sk);
458 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
459
460 atomic64_set(&rx_ctx->resync_async->req,
461 ((u64)ntohl(seq) << 32) | RESYNC_REQ);
462 }
463
464 static inline void
465 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type)
466 {
467 struct tls_context *tls_ctx = tls_get_ctx(sk);
468
469 tls_offload_ctx_rx(tls_ctx)->resync_type = type;
470 }
471
472 /* Driver's seq tracking has to be disabled until resync succeeded */
473 static inline bool tls_offload_tx_resync_pending(struct sock *sk)
474 {
475 struct tls_context *tls_ctx = tls_get_ctx(sk);
476 bool ret;
477
478 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
479 smp_mb__after_atomic();
480 return ret;
481 }
482
483 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
484
485 #ifdef CONFIG_TLS_DEVICE
486 void tls_device_sk_destruct(struct sock *sk);
487 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
488
489 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
490 {
491 if (!sk_fullsock(sk) ||
492 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct)
493 return false;
494 return tls_get_ctx(sk)->rx_conf == TLS_HW;
495 }
496 #endif
497 #endif /* _TLS_OFFLOAD_H */
498
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