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/* Minimum record size limit as per RFC8449 */
57#define TLS_MIN_RECORD_SIZE_LIM ((size_t)1 << 6)
58
59#define TLS_HEADER_SIZE 5
60#define TLS_NONCE_OFFSET TLS_HEADER_SIZE
61
62#define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
63
64#define TLS_HANDSHAKE_KEYUPDATE 24 /* rfc8446 B.3: Key update */
65
66#define TLS_AAD_SPACE_SIZE 13
67
68#define TLS_MAX_IV_SIZE 16
69#define TLS_MAX_SALT_SIZE 4
70#define TLS_TAG_SIZE 16
71#define TLS_MAX_REC_SEQ_SIZE 8
72#define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE
73
74/* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
75 *
76 * IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3]
77 *
78 * The field 'length' is encoded in field 'b0' as '(length width - 1)'.
79 * Hence b0 contains (3 - 1) = 2.
80 */
81#define TLS_AES_CCM_IV_B0_BYTE 2
82#define TLS_SM4_CCM_IV_B0_BYTE 2
83
84enum {
85 TLS_BASE,
86 TLS_SW,
87 TLS_HW,
88 TLS_HW_RECORD,
89 TLS_NUM_CONFIG,
90};
91
92struct tx_work {
93 struct delayed_work work;
94 struct sock *sk;
95};
96
97struct tls_sw_context_tx {
98 struct crypto_aead *aead_send;
99 struct crypto_wait async_wait;
100 struct tx_work tx_work;
101 struct tls_rec *open_rec;
102 struct list_head tx_list;
103 atomic_t encrypt_pending;
104 u8 async_capable:1;
105
106#define BIT_TX_SCHEDULED 0
107#define BIT_TX_CLOSING 1
108 unsigned long tx_bitmask;
109};
110
111struct tls_strparser {
112 struct sock *sk;
113
114 u32 mark : 8;
115 u32 stopped : 1;
116 u32 copy_mode : 1;
117 u32 mixed_decrypted : 1;
118
119 bool msg_ready;
120
121 struct strp_msg stm;
122
123 struct sk_buff *anchor;
124 struct work_struct work;
125};
126
127struct tls_sw_context_rx {
128 struct crypto_aead *aead_recv;
129 struct crypto_wait async_wait;
130 struct sk_buff_head rx_list; /* list of decrypted 'data' records */
131 void (*saved_data_ready)(struct sock *sk);
132
133 u8 reader_present;
134 u8 async_capable:1;
135 u8 zc_capable:1;
136 u8 reader_contended:1;
137 bool key_update_pending;
138
139 struct tls_strparser strp;
140
141 atomic_t decrypt_pending;
142 struct sk_buff_head async_hold;
143 struct wait_queue_head wq;
144};
145
146struct 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
155struct 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
175enum 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
194struct cipher_context {
195 char iv[TLS_MAX_IV_SIZE + TLS_MAX_SALT_SIZE];
196 char rec_seq[TLS_MAX_REC_SEQ_SIZE];
197};
198
199union 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
210struct 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
223struct 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 u16 tx_max_payload_len;
232
233 int (*push_pending_record)(struct sock *sk, int flags);
234 void (*sk_write_space)(struct sock *sk);
235
236 void *priv_ctx_tx;
237 void *priv_ctx_rx;
238
239 struct net_device __rcu *netdev;
240
241 /* rw cache line */
242 struct cipher_context tx;
243 struct cipher_context rx;
244
245 struct scatterlist *partially_sent_record;
246 u16 partially_sent_offset;
247
248 bool splicing_pages;
249 bool pending_open_record_frags;
250
251 struct mutex tx_lock; /* protects partially_sent_* fields and
252 * per-type TX fields
253 */
254 unsigned long flags;
255
256 /* cache cold stuff */
257 struct proto *sk_proto;
258 struct sock *sk;
259
260 void (*sk_destruct)(struct sock *sk);
261
262 union tls_crypto_context crypto_send;
263 union tls_crypto_context crypto_recv;
264
265 struct list_head list;
266 refcount_t refcount;
267 struct rcu_head rcu;
268};
269
270enum tls_offload_ctx_dir {
271 TLS_OFFLOAD_CTX_DIR_RX,
272 TLS_OFFLOAD_CTX_DIR_TX,
273};
274
275struct tlsdev_ops {
276 int (*tls_dev_add)(struct net_device *netdev, struct sock *sk,
277 enum tls_offload_ctx_dir direction,
278 struct tls_crypto_info *crypto_info,
279 u32 start_offload_tcp_sn);
280 void (*tls_dev_del)(struct net_device *netdev,
281 struct tls_context *ctx,
282 enum tls_offload_ctx_dir direction);
283 int (*tls_dev_resync)(struct net_device *netdev,
284 struct sock *sk, u32 seq, u8 *rcd_sn,
285 enum tls_offload_ctx_dir direction);
286};
287
288enum tls_offload_sync_type {
289 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0,
290 TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1,
291 TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2,
292};
293
294#define TLS_DEVICE_RESYNC_NH_START_IVAL 2
295#define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
296
297#define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13
298struct tls_offload_resync_async {
299 atomic64_t req;
300 u16 loglen;
301 u16 rcd_delta;
302 u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX];
303};
304
305#define TLS_DRIVER_STATE_SIZE_RX 8
306struct tls_offload_context_rx {
307 /* sw must be the first member of tls_offload_context_rx */
308 struct tls_sw_context_rx sw;
309 enum tls_offload_sync_type resync_type;
310 /* this member is set regardless of resync_type, to avoid branches */
311 u8 resync_nh_reset:1;
312 /* CORE_NEXT_HINT-only member, but use the hole here */
313 u8 resync_nh_do_now:1;
314 union {
315 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */
316 struct {
317 atomic64_t resync_req;
318 };
319 /* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */
320 struct {
321 u32 decrypted_failed;
322 u32 decrypted_tgt;
323 } resync_nh;
324 /* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */
325 struct {
326 struct tls_offload_resync_async *resync_async;
327 };
328 };
329 /* The TLS layer reserves room for driver specific state
330 * Currently the belief is that there is not enough
331 * driver specific state to justify another layer of indirection
332 */
333 u8 driver_state[TLS_DRIVER_STATE_SIZE_RX] __aligned(8);
334};
335
336struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
337 u32 seq, u64 *p_record_sn);
338
339static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
340{
341 return rec->len == 0;
342}
343
344static inline u32 tls_record_start_seq(struct tls_record_info *rec)
345{
346 return rec->end_seq - rec->len;
347}
348
349struct sk_buff *
350tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
351 struct sk_buff *skb);
352struct sk_buff *
353tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev,
354 struct sk_buff *skb);
355
356static inline bool tls_is_skb_tx_device_offloaded(const struct sk_buff *skb)
357{
358#ifdef CONFIG_TLS_DEVICE
359 struct sock *sk = skb->sk;
360
361 return sk && sk_fullsock(sk) &&
362 (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
363 &tls_validate_xmit_skb);
364#else
365 return false;
366#endif
367}
368
369static inline struct tls_context *tls_get_ctx(const struct sock *sk)
370{
371 const struct inet_connection_sock *icsk = inet_csk(sk);
372
373 /* Use RCU on icsk_ulp_data only for sock diag code,
374 * TLS data path doesn't need rcu_dereference().
375 */
376 return (__force void *)icsk->icsk_ulp_data;
377}
378
379static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
380 const struct tls_context *tls_ctx)
381{
382 return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
383}
384
385static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
386 const struct tls_context *tls_ctx)
387{
388 return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
389}
390
391static inline struct tls_offload_context_tx *
392tls_offload_ctx_tx(const struct tls_context *tls_ctx)
393{
394 return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
395}
396
397static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
398{
399 struct tls_context *ctx;
400
401 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk))
402 return false;
403
404 ctx = tls_get_ctx(sk);
405 if (!ctx)
406 return false;
407 return !!tls_sw_ctx_tx(tls_ctx: ctx);
408}
409
410static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
411{
412 struct tls_context *ctx;
413
414 if (!sk_is_inet(sk) || !inet_test_bit(IS_ICSK, sk))
415 return false;
416
417 ctx = tls_get_ctx(sk);
418 if (!ctx)
419 return false;
420 return !!tls_sw_ctx_rx(tls_ctx: ctx);
421}
422
423static inline struct tls_offload_context_rx *
424tls_offload_ctx_rx(const struct tls_context *tls_ctx)
425{
426 return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
427}
428
429static inline void *__tls_driver_ctx(struct tls_context *tls_ctx,
430 enum tls_offload_ctx_dir direction)
431{
432 if (direction == TLS_OFFLOAD_CTX_DIR_TX)
433 return tls_offload_ctx_tx(tls_ctx)->driver_state;
434 else
435 return tls_offload_ctx_rx(tls_ctx)->driver_state;
436}
437
438static inline void *
439tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction)
440{
441 return __tls_driver_ctx(tls_ctx: tls_get_ctx(sk), direction);
442}
443
444#define RESYNC_REQ BIT(0)
445#define RESYNC_REQ_ASYNC BIT(1)
446/* The TLS context is valid until sk_destruct is called */
447static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
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_req, i: ((u64)ntohl(seq) << 32) | RESYNC_REQ);
453}
454
455/* Log all TLS record header TCP sequences in [seq, seq+len] */
456static inline void
457tls_offload_rx_resync_async_request_start(struct tls_offload_resync_async *resync_async,
458 __be32 seq, u16 len)
459{
460 atomic64_set(v: &resync_async->req, i: ((u64)ntohl(seq) << 32) |
461 ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
462 resync_async->loglen = 0;
463 resync_async->rcd_delta = 0;
464}
465
466static inline void
467tls_offload_rx_resync_async_request_end(struct tls_offload_resync_async *resync_async,
468 __be32 seq)
469{
470 atomic64_set(v: &resync_async->req, i: ((u64)ntohl(seq) << 32) | RESYNC_REQ);
471}
472
473static inline void
474tls_offload_rx_resync_async_request_cancel(struct tls_offload_resync_async *resync_async)
475{
476 atomic64_set(v: &resync_async->req, i: 0);
477}
478
479static inline void
480tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type)
481{
482 struct tls_context *tls_ctx = tls_get_ctx(sk);
483
484 tls_offload_ctx_rx(tls_ctx)->resync_type = type;
485}
486
487/* Driver's seq tracking has to be disabled until resync succeeded */
488static inline bool tls_offload_tx_resync_pending(struct sock *sk)
489{
490 struct tls_context *tls_ctx = tls_get_ctx(sk);
491 bool ret;
492
493 ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
494 smp_mb__after_atomic();
495 return ret;
496}
497
498struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
499
500#ifdef CONFIG_TLS_DEVICE
501void tls_device_sk_destruct(struct sock *sk);
502void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
503
504static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
505{
506 if (!sk_fullsock(sk) ||
507 smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct)
508 return false;
509 return tls_get_ctx(sk)->rx_conf == TLS_HW;
510}
511#endif
512#endif /* _TLS_OFFLOAD_H */
513

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