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

source code of linux/include/net/tls.h