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 #include <linux/android_kabi.h>
46
47 #include <net/net_namespace.h>
48 #include <net/tcp.h>
49 #include <net/strparser.h>
50 #include <crypto/aead.h>
51 #include <uapi/linux/tls.h>
52
53 struct tls_rec;
54
55 /* Maximum data size carried in a TLS record */
56 #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
57
58 #define TLS_HEADER_SIZE 5
59 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE
60
61 #define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
62
63 #define TLS_AAD_SPACE_SIZE 13
64
65 #define TLS_MAX_IV_SIZE 16
66 #define TLS_MAX_SALT_SIZE 4
67 #define TLS_TAG_SIZE 16
68 #define TLS_MAX_REC_SEQ_SIZE 8
69 #define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE
70
71 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
72 *
73 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3]
74 *
75 * The field 'length' is encoded in field 'b0' as '(length width - 1)'.
76 * Hence b0 contains (3 - 1) = 2.
77 */
78 #define TLS_AES_CCM_IV_B0_BYTE 2
79 #define TLS_SM4_CCM_IV_B0_BYTE 2
80
81 enum {
82 TLS_BASE,
83 TLS_SW,
84 TLS_HW,
85 TLS_HW_RECORD,
86 TLS_NUM_CONFIG,
87 };
88
89 struct tx_work {
90 struct delayed_work work;
91 struct sock *sk;
92 };
93
94 struct tls_sw_context_tx {
95 struct crypto_aead *aead_send;
96 struct crypto_wait async_wait;
97 struct tx_work tx_work;
98 struct tls_rec *open_rec;
99 struct list_head tx_list;
100 atomic_t encrypt_pending;
101 u8 async_capable:1;
102
103 #define BIT_TX_SCHEDULED 0
104 #define BIT_TX_CLOSING 1
105 unsigned long tx_bitmask;
106
107 ANDROID_KABI_RESERVE(1);
108 };
109
110 struct tls_strparser {
111 struct sock *sk;
112
113 u32 mark : 8;
114 u32 stopped : 1;
115 u32 copy_mode : 1;
116 u32 mixed_decrypted : 1;
117
118 bool msg_ready;
119
120 struct strp_msg stm;
121
122 struct sk_buff *anchor;
123 struct work_struct work;
124 };
125
126 struct tls_sw_context_rx {
127 struct crypto_aead *aead_recv;
128 struct crypto_wait async_wait;
129 struct sk_buff_head rx_list; /* list of decrypted 'data' records */
130 void (*saved_data_ready)(struct sock *sk);
131
132 u8 reader_present;
133 u8 async_capable:1;
134 u8 zc_capable:1;
135 u8 reader_contended:1;
136
137 struct tls_strparser strp;
138
139 atomic_t decrypt_pending;
140 struct sk_buff_head async_hold;
141 struct wait_queue_head wq;
142
143 ANDROID_KABI_RESERVE(1);
144 };
145
146 struct tls_record_info {
147 struct list_head list;
148 u32 end_seq;
149 int len;
150 int num_frags;
151 skb_frag_t frags[MAX_SKB_FRAGS];
152 };
153
154 #define TLS_DRIVER_STATE_SIZE_TX 16
155 struct tls_offload_context_tx {
156 struct crypto_aead *aead_send;
157 spinlock_t lock; /* protects records list */
158 struct list_head records_list;
159 struct tls_record_info *open_record;
160 struct tls_record_info *retransmit_hint;
161 u64 hint_record_sn;
162 u64 unacked_record_sn;
163
164 struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
165 void (*sk_destruct)(struct sock *sk);
166 struct work_struct destruct_work;
167 struct tls_context *ctx;
168 /* The TLS layer reserves room for driver specific state
169 * Currently the belief is that there is not enough
170 * driver specific state to justify another layer of indirection
171 */
172 u8 driver_state[TLS_DRIVER_STATE_SIZE_TX] __aligned(8);
173 };
174
175 enum tls_context_flags {
176 /* tls_device_down was called after the netdev went down, device state
177 * was released, and kTLS works in software, even though rx_conf is
178 * still TLS_HW (needed for transition).
179 */
180 TLS_RX_DEV_DEGRADED = 0,
181 /* Unlike RX where resync is driven entirely by the core in TX only
182 * the driver knows when things went out of sync, so we need the flag
183 * to be atomic.
184 */
185 TLS_TX_SYNC_SCHED = 1,
186 /* tls_dev_del was called for the RX side, device state was released,
187 * but tls_ctx->netdev might still be kept, because TX-side driver
188 * resources might not be released yet. Used to prevent the second
189 * tls_dev_del call in tls_device_down if it happens simultaneously.
190 */
191 TLS_RX_DEV_CLOSED = 2,
192 };
193
194 struct cipher_context {
195 char iv[TLS_MAX_IV_SIZE + TLS_MAX_SALT_SIZE];
196 char rec_seq[TLS_MAX_REC_SEQ_SIZE];
197 };
198
199 union tls_crypto_context {
200 struct tls_crypto_info info;
201 union {
202 struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
203 struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
204 struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305;
205 struct tls12_crypto_info_sm4_gcm sm4_gcm;
206 struct tls12_crypto_info_sm4_ccm sm4_ccm;
207 };
208 };
209
210 struct tls_prot_info {
211 u16 version;
212 u16 cipher_type;
213 u16 prepend_size;
214 u16 tag_size;
215 u16 overhead_size;
216 u16 iv_size;
217 u16 salt_size;
218 u16 rec_seq_size;
219 u16 aad_size;
220 u16 tail_size;
221 };
222
223 struct tls_context {
224 /* read-only cache line */
225 struct tls_prot_info prot_info;
226
227 u8 tx_conf:3;
228 u8 rx_conf:3;
229 u8 zerocopy_sendfile:1;
230 u8 rx_no_pad:1;
231
232 int (*push_pending_record)(struct sock *sk, int flags);
233 void (*sk_write_space)(struct sock *sk);
234
235 void *priv_ctx_tx;
236 void *priv_ctx_rx;
237
238 struct net_device __rcu *netdev;
239
240 /* rw cache line */
241 struct cipher_context tx;
242 struct cipher_context rx;
243
244 struct scatterlist *partially_sent_record;
245 u16 partially_sent_offset;
246
247 bool splicing_pages;
248 bool pending_open_record_frags;
249
250 struct mutex tx_lock; /* protects partially_sent_* fields and
251 * per-type TX fields
252 */
253 unsigned long flags;
254
255 /* cache cold stuff */
256 struct proto *sk_proto;
257 struct sock *sk;
258
259 void (*sk_destruct)(struct sock *sk);
260
261 union tls_crypto_context crypto_send;
262 union tls_crypto_context crypto_recv;
263
264 struct list_head list;
265 refcount_t refcount;
266 struct rcu_head rcu;
267 };
268
269 enum tls_offload_ctx_dir {
270 TLS_OFFLOAD_CTX_DIR_RX,
271 TLS_OFFLOAD_CTX_DIR_TX,
272 };
273
274 struct tlsdev_ops {
275 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk,
276 enum tls_offload_ctx_dir direction,
277 struct tls_crypto_info *crypto_info,
278 u32 start_offload_tcp_sn);
279 void (*tls_dev_del)(struct net_device *netdev,
280 struct tls_context *ctx,
281 enum tls_offload_ctx_dir direction);
282 int (*tls_dev_resync)(struct net_device *netdev,
283 struct sock *sk, u32 seq, u8 *rcd_sn,
284 enum tls_offload_ctx_dir direction);
285
286 ANDROID_KABI_RESERVE(1);
287 ANDROID_KABI_RESERVE(2);
288 ANDROID_KABI_RESERVE(3);
289 ANDROID_KABI_RESERVE(4);
290
291 };
292
293 enum tls_offload_sync_type {
294 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0,
295 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1,
296 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2,
297 };
298
299 #define TLS_DEVICE_RESYNC_NH_START_IVAL 2
300 #define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
301
302 #define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13
303 struct tls_offload_resync_async {
304 atomic64_t req;
305 u16 loglen;
306 u16 rcd_delta;
307 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX];
308 };
309
310 #define TLS_DRIVER_STATE_SIZE_RX 8
311 struct tls_offload_context_rx {
312 /* sw must be the first member of tls_offload_context_rx */
313 struct tls_sw_context_rx sw;
314 enum tls_offload_sync_type resync_type;
315 /* this member is set regardless of resync_type, to avoid branches */
316 u8 resync_nh_reset:1;
317 /* CORE_NEXT_HINT-only member, but use the hole here */
318 u8 resync_nh_do_now:1;
319 union {
320 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */
321 struct {
322 atomic64_t resync_req;
323 };
324 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */
325 struct {
326 u32 decrypted_failed;
327 u32 decrypted_tgt;
328 } resync_nh;
329 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */
330 struct {
331 struct tls_offload_resync_async *resync_async;
332 };
333 };
334 /* The TLS layer reserves room for driver specific state
335 * Currently the belief is that there is not enough
336 * driver specific state to justify another layer of indirection
337 */
338 u8 driver_state[TLS_DRIVER_STATE_SIZE_RX] __aligned(8);
339 };
340
341 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
342 u32 seq, u64 *p_record_sn);
343
tls_record_is_start_marker(struct tls_record_info * rec)344 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
345 {
346 return rec->len == 0;
347 }
348
tls_record_start_seq(struct tls_record_info * rec)349 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
350 {
351 return rec->end_seq - rec->len;
352 }
353
354 struct sk_buff *
355 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
356 struct sk_buff *skb);
357 struct sk_buff *
358 tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev,
359 struct sk_buff *skb);
360
tls_is_skb_tx_device_offloaded(const struct sk_buff * skb)361 static inline bool tls_is_skb_tx_device_offloaded(const struct sk_buff *skb)
362 {
363 #ifdef CONFIG_TLS_DEVICE
364 struct sock *sk = skb->sk;
365
366 return sk && sk_fullsock(sk) &&
367 (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
368 &tls_validate_xmit_skb);
369 #else
370 return false;
371 #endif
372 }
373
tls_get_ctx(const struct sock * sk)374 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
375 {
376 const struct inet_connection_sock *icsk = inet_csk(sk);
377
378 /* Use RCU on icsk_ulp_data only for sock diag code,
379 * TLS data path doesn't need rcu_dereference().
380 */
381 return (__force void *)icsk->icsk_ulp_data;
382 }
383
tls_sw_ctx_rx(const struct tls_context * tls_ctx)384 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
385 const struct tls_context *tls_ctx)
386 {
387 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
388 }
389
tls_sw_ctx_tx(const struct tls_context * tls_ctx)390 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
391 const struct tls_context *tls_ctx)
392 {
393 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
394 }
395
396 static inline struct tls_offload_context_tx *
tls_offload_ctx_tx(const struct tls_context * tls_ctx)397 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
398 {
399 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
400 }
401
tls_sw_has_ctx_tx(const struct sock * sk)402 static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
403 {
404 struct tls_context *ctx;
405
406 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk))
407 return false;
408
409 ctx = tls_get_ctx(sk);
410 if (!ctx)
411 return false;
412 return !!tls_sw_ctx_tx(ctx);
413 }
414
tls_sw_has_ctx_rx(const struct sock * sk)415 static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
416 {
417 struct tls_context *ctx;
418
419 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk))
420 return false;
421
422 ctx = tls_get_ctx(sk);
423 if (!ctx)
424 return false;
425 return !!tls_sw_ctx_rx(ctx);
426 }
427
428 static inline struct tls_offload_context_rx *
tls_offload_ctx_rx(const struct tls_context * tls_ctx)429 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
430 {
431 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
432 }
433
__tls_driver_ctx(struct tls_context * tls_ctx,enum tls_offload_ctx_dir direction)434 static inline void *__tls_driver_ctx(struct tls_context *tls_ctx,
435 enum tls_offload_ctx_dir direction)
436 {
437 if (direction == TLS_OFFLOAD_CTX_DIR_TX)
438 return tls_offload_ctx_tx(tls_ctx)->driver_state;
439 else
440 return tls_offload_ctx_rx(tls_ctx)->driver_state;
441 }
442
443 static inline void *
tls_driver_ctx(const struct sock * sk,enum tls_offload_ctx_dir direction)444 tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction)
445 {
446 return __tls_driver_ctx(tls_get_ctx(sk), direction);
447 }
448
449 #define RESYNC_REQ BIT(0)
450 #define RESYNC_REQ_ASYNC BIT(1)
451 /* The TLS context is valid until sk_destruct is called */
tls_offload_rx_resync_request(struct sock * sk,__be32 seq)452 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
453 {
454 struct tls_context *tls_ctx = tls_get_ctx(sk);
455 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
456
457 atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ);
458 }
459
460 /* Log all TLS record header TCP sequences in [seq, seq+len] */
461 static inline void
tls_offload_rx_resync_async_request_start(struct sock * sk,__be32 seq,u16 len)462 tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
463 {
464 struct tls_context *tls_ctx = tls_get_ctx(sk);
465 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
466
467 atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
468 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
469 rx_ctx->resync_async->loglen = 0;
470 rx_ctx->resync_async->rcd_delta = 0;
471 }
472
473 static inline void
tls_offload_rx_resync_async_request_end(struct sock * sk,__be32 seq)474 tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq)
475 {
476 struct tls_context *tls_ctx = tls_get_ctx(sk);
477 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
478
479 atomic64_set(&rx_ctx->resync_async->req,
480 ((u64)ntohl(seq) << 32) | RESYNC_REQ);
481 }
482
483 static inline void
tls_offload_rx_resync_set_type(struct sock * sk,enum tls_offload_sync_type type)484 tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type)
485 {
486 struct tls_context *tls_ctx = tls_get_ctx(sk);
487
488 tls_offload_ctx_rx(tls_ctx)->resync_type = type;
489 }
490
491 /* Driver's seq tracking has to be disabled until resync succeeded */
tls_offload_tx_resync_pending(struct sock * sk)492 static inline bool tls_offload_tx_resync_pending(struct sock *sk)
493 {
494 struct tls_context *tls_ctx = tls_get_ctx(sk);
495 bool ret;
496
497 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
498 smp_mb__after_atomic();
499 return ret;
500 }
501
502 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
503
504 #ifdef CONFIG_TLS_DEVICE
505 void tls_device_sk_destruct(struct sock *sk);
506 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
507
tls_is_sk_rx_device_offloaded(struct sock * sk)508 static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
509 {
510 if (!sk_fullsock(sk) ||
511 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct)
512 return false;
513 return tls_get_ctx(sk)->rx_conf == TLS_HW;
514 }
515 #endif
516 #endif /* _TLS_OFFLOAD_H */
517