xref: /linux/include/net/tls.h (revision f6f3bac08ff9855d803081a353a1fafaa8845739)
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 <net/tcp.h>
43 #include <net/strparser.h>
44 
45 #include <uapi/linux/tls.h>
46 
47 
48 /* Maximum data size carried in a TLS record */
49 #define TLS_MAX_PAYLOAD_SIZE		((size_t)1 << 14)
50 
51 #define TLS_HEADER_SIZE			5
52 #define TLS_NONCE_OFFSET		TLS_HEADER_SIZE
53 
54 #define TLS_CRYPTO_INFO_READY(info)	((info)->cipher_type)
55 
56 #define TLS_RECORD_TYPE_DATA		0x17
57 
58 #define TLS_AAD_SPACE_SIZE		13
59 #define TLS_DEVICE_NAME_MAX		32
60 
61 /*
62  * This structure defines the routines for Inline TLS driver.
63  * The following routines are optional and filled with a
64  * null pointer if not defined.
65  *
66  * @name: Its the name of registered Inline tls device
67  * @dev_list: Inline tls device list
68  * int (*feature)(struct tls_device *device);
69  *     Called to return Inline TLS driver capability
70  *
71  * int (*hash)(struct tls_device *device, struct sock *sk);
72  *     This function sets Inline driver for listen and program
73  *     device specific functioanlity as required
74  *
75  * void (*unhash)(struct tls_device *device, struct sock *sk);
76  *     This function cleans listen state set by Inline TLS driver
77  */
78 struct tls_device {
79 	char name[TLS_DEVICE_NAME_MAX];
80 	struct list_head dev_list;
81 	int  (*feature)(struct tls_device *device);
82 	int  (*hash)(struct tls_device *device, struct sock *sk);
83 	void (*unhash)(struct tls_device *device, struct sock *sk);
84 };
85 
86 enum {
87 	TLS_BASE,
88 	TLS_SW,
89 #ifdef CONFIG_TLS_DEVICE
90 	TLS_HW,
91 #endif
92 	TLS_HW_RECORD,
93 	TLS_NUM_CONFIG,
94 };
95 
96 struct tls_sw_context_tx {
97 	struct crypto_aead *aead_send;
98 	struct crypto_wait async_wait;
99 
100 	char aad_space[TLS_AAD_SPACE_SIZE];
101 
102 	unsigned int sg_plaintext_size;
103 	int sg_plaintext_num_elem;
104 	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
105 
106 	unsigned int sg_encrypted_size;
107 	int sg_encrypted_num_elem;
108 	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
109 
110 	/* AAD | sg_plaintext_data | sg_tag */
111 	struct scatterlist sg_aead_in[2];
112 	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
113 	struct scatterlist sg_aead_out[2];
114 };
115 
116 struct tls_sw_context_rx {
117 	struct crypto_aead *aead_recv;
118 	struct crypto_wait async_wait;
119 
120 	struct strparser strp;
121 	void (*saved_data_ready)(struct sock *sk);
122 	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
123 				struct poll_table_struct *wait);
124 	struct sk_buff *recv_pkt;
125 	u8 control;
126 	bool decrypted;
127 	atomic_t decrypt_pending;
128 	bool async_notify;
129 };
130 
131 struct decrypt_req_ctx {
132 	struct sock *sk;
133 };
134 
135 struct tls_record_info {
136 	struct list_head list;
137 	u32 end_seq;
138 	int len;
139 	int num_frags;
140 	skb_frag_t frags[MAX_SKB_FRAGS];
141 };
142 
143 struct tls_offload_context_tx {
144 	struct crypto_aead *aead_send;
145 	spinlock_t lock;	/* protects records list */
146 	struct list_head records_list;
147 	struct tls_record_info *open_record;
148 	struct tls_record_info *retransmit_hint;
149 	u64 hint_record_sn;
150 	u64 unacked_record_sn;
151 
152 	struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
153 	void (*sk_destruct)(struct sock *sk);
154 	u8 driver_state[];
155 	/* The TLS layer reserves room for driver specific state
156 	 * Currently the belief is that there is not enough
157 	 * driver specific state to justify another layer of indirection
158 	 */
159 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
160 };
161 
162 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
163 	(ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
164 	 TLS_DRIVER_STATE_SIZE)
165 
166 enum {
167 	TLS_PENDING_CLOSED_RECORD
168 };
169 
170 struct cipher_context {
171 	u16 prepend_size;
172 	u16 tag_size;
173 	u16 overhead_size;
174 	u16 iv_size;
175 	char *iv;
176 	u16 rec_seq_size;
177 	char *rec_seq;
178 };
179 
180 struct tls_context {
181 	union {
182 		struct tls_crypto_info crypto_send;
183 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
184 	};
185 	union {
186 		struct tls_crypto_info crypto_recv;
187 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
188 	};
189 
190 	struct list_head list;
191 	struct net_device *netdev;
192 	refcount_t refcount;
193 
194 	void *priv_ctx_tx;
195 	void *priv_ctx_rx;
196 
197 	u8 tx_conf:3;
198 	u8 rx_conf:3;
199 
200 	struct cipher_context tx;
201 	struct cipher_context rx;
202 
203 	struct scatterlist *partially_sent_record;
204 	u16 partially_sent_offset;
205 	unsigned long flags;
206 	bool in_tcp_sendpages;
207 
208 	u16 pending_open_record_frags;
209 	int (*push_pending_record)(struct sock *sk, int flags);
210 
211 	void (*sk_write_space)(struct sock *sk);
212 	void (*sk_destruct)(struct sock *sk);
213 	void (*sk_proto_close)(struct sock *sk, long timeout);
214 
215 	int  (*setsockopt)(struct sock *sk, int level,
216 			   int optname, char __user *optval,
217 			   unsigned int optlen);
218 	int  (*getsockopt)(struct sock *sk, int level,
219 			   int optname, char __user *optval,
220 			   int __user *optlen);
221 	int  (*hash)(struct sock *sk);
222 	void (*unhash)(struct sock *sk);
223 };
224 
225 struct tls_offload_context_rx {
226 	/* sw must be the first member of tls_offload_context_rx */
227 	struct tls_sw_context_rx sw;
228 	atomic64_t resync_req;
229 	u8 driver_state[];
230 	/* The TLS layer reserves room for driver specific state
231 	 * Currently the belief is that there is not enough
232 	 * driver specific state to justify another layer of indirection
233 	 */
234 };
235 
236 #define TLS_OFFLOAD_CONTEXT_SIZE_RX					\
237 	(ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
238 	 TLS_DRIVER_STATE_SIZE)
239 
240 int wait_on_pending_writer(struct sock *sk, long *timeo);
241 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
242 		int __user *optlen);
243 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
244 		  unsigned int optlen);
245 
246 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
247 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
248 int tls_sw_sendpage(struct sock *sk, struct page *page,
249 		    int offset, size_t size, int flags);
250 void tls_sw_close(struct sock *sk, long timeout);
251 void tls_sw_free_resources_tx(struct sock *sk);
252 void tls_sw_free_resources_rx(struct sock *sk);
253 void tls_sw_release_resources_rx(struct sock *sk);
254 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
255 		   int nonblock, int flags, int *addr_len);
256 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
257 			 struct poll_table_struct *wait);
258 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
259 			   struct pipe_inode_info *pipe,
260 			   size_t len, unsigned int flags);
261 
262 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
263 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
264 int tls_device_sendpage(struct sock *sk, struct page *page,
265 			int offset, size_t size, int flags);
266 void tls_device_sk_destruct(struct sock *sk);
267 void tls_device_init(void);
268 void tls_device_cleanup(void);
269 
270 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
271 				       u32 seq, u64 *p_record_sn);
272 
273 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
274 {
275 	return rec->len == 0;
276 }
277 
278 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
279 {
280 	return rec->end_seq - rec->len;
281 }
282 
283 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
284 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
285 		struct scatterlist *sg, u16 first_offset,
286 		int flags);
287 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
288 				   int flags, long *timeo);
289 
290 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
291 {
292 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
293 }
294 
295 static inline int tls_complete_pending_work(struct sock *sk,
296 					    struct tls_context *ctx,
297 					    int flags, long *timeo)
298 {
299 	int rc = 0;
300 
301 	if (unlikely(sk->sk_write_pending))
302 		rc = wait_on_pending_writer(sk, timeo);
303 
304 	if (!rc && tls_is_pending_closed_record(ctx))
305 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
306 
307 	return rc;
308 }
309 
310 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
311 {
312 	return !!ctx->partially_sent_record;
313 }
314 
315 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
316 {
317 	return tls_ctx->pending_open_record_frags;
318 }
319 
320 struct sk_buff *
321 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
322 		      struct sk_buff *skb);
323 
324 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
325 {
326 #ifdef CONFIG_SOCK_VALIDATE_XMIT
327 	return sk_fullsock(sk) &
328 	       (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
329 	       &tls_validate_xmit_skb);
330 #else
331 	return false;
332 #endif
333 }
334 
335 static inline void tls_err_abort(struct sock *sk, int err)
336 {
337 	sk->sk_err = err;
338 	sk->sk_error_report(sk);
339 }
340 
341 static inline bool tls_bigint_increment(unsigned char *seq, int len)
342 {
343 	int i;
344 
345 	for (i = len - 1; i >= 0; i--) {
346 		++seq[i];
347 		if (seq[i] != 0)
348 			break;
349 	}
350 
351 	return (i == -1);
352 }
353 
354 static inline void tls_advance_record_sn(struct sock *sk,
355 					 struct cipher_context *ctx)
356 {
357 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
358 		tls_err_abort(sk, EBADMSG);
359 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
360 			     ctx->iv_size);
361 }
362 
363 static inline void tls_fill_prepend(struct tls_context *ctx,
364 			     char *buf,
365 			     size_t plaintext_len,
366 			     unsigned char record_type)
367 {
368 	size_t pkt_len, iv_size = ctx->tx.iv_size;
369 
370 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
371 
372 	/* we cover nonce explicit here as well, so buf should be of
373 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
374 	 */
375 	buf[0] = record_type;
376 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
377 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
378 	/* we can use IV for nonce explicit according to spec */
379 	buf[3] = pkt_len >> 8;
380 	buf[4] = pkt_len & 0xFF;
381 	memcpy(buf + TLS_NONCE_OFFSET,
382 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
383 }
384 
385 static inline void tls_make_aad(char *buf,
386 				size_t size,
387 				char *record_sequence,
388 				int record_sequence_size,
389 				unsigned char record_type)
390 {
391 	memcpy(buf, record_sequence, record_sequence_size);
392 
393 	buf[8] = record_type;
394 	buf[9] = TLS_1_2_VERSION_MAJOR;
395 	buf[10] = TLS_1_2_VERSION_MINOR;
396 	buf[11] = size >> 8;
397 	buf[12] = size & 0xFF;
398 }
399 
400 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
401 {
402 	struct inet_connection_sock *icsk = inet_csk(sk);
403 
404 	return icsk->icsk_ulp_data;
405 }
406 
407 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
408 		const struct tls_context *tls_ctx)
409 {
410 	return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
411 }
412 
413 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
414 		const struct tls_context *tls_ctx)
415 {
416 	return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
417 }
418 
419 static inline struct tls_offload_context_tx *
420 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
421 {
422 	return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
423 }
424 
425 static inline struct tls_offload_context_rx *
426 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
427 {
428 	return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
429 }
430 
431 /* The TLS context is valid until sk_destruct is called */
432 static 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(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
438 }
439 
440 
441 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
442 		      unsigned char *record_type);
443 void tls_register_device(struct tls_device *device);
444 void tls_unregister_device(struct tls_device *device);
445 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
446 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
447 		struct scatterlist *sgout);
448 
449 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
450 				      struct net_device *dev,
451 				      struct sk_buff *skb);
452 
453 int tls_sw_fallback_init(struct sock *sk,
454 			 struct tls_offload_context_tx *offload_ctx,
455 			 struct tls_crypto_info *crypto_info);
456 
457 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
458 
459 void tls_device_offload_cleanup_rx(struct sock *sk);
460 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
461 
462 #endif /* _TLS_OFFLOAD_H */
463