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

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