xref: /linux/include/net/tls.h (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
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 };
128 
129 struct tls_record_info {
130 	struct list_head list;
131 	u32 end_seq;
132 	int len;
133 	int num_frags;
134 	skb_frag_t frags[MAX_SKB_FRAGS];
135 };
136 
137 struct tls_offload_context_tx {
138 	struct crypto_aead *aead_send;
139 	spinlock_t lock;	/* protects records list */
140 	struct list_head records_list;
141 	struct tls_record_info *open_record;
142 	struct tls_record_info *retransmit_hint;
143 	u64 hint_record_sn;
144 	u64 unacked_record_sn;
145 
146 	struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
147 	void (*sk_destruct)(struct sock *sk);
148 	u8 driver_state[];
149 	/* The TLS layer reserves room for driver specific state
150 	 * Currently the belief is that there is not enough
151 	 * driver specific state to justify another layer of indirection
152 	 */
153 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
154 };
155 
156 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
157 	(ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
158 	 TLS_DRIVER_STATE_SIZE)
159 
160 enum {
161 	TLS_PENDING_CLOSED_RECORD
162 };
163 
164 struct cipher_context {
165 	u16 prepend_size;
166 	u16 tag_size;
167 	u16 overhead_size;
168 	u16 iv_size;
169 	char *iv;
170 	u16 rec_seq_size;
171 	char *rec_seq;
172 };
173 
174 struct tls_context {
175 	union {
176 		struct tls_crypto_info crypto_send;
177 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
178 	};
179 	union {
180 		struct tls_crypto_info crypto_recv;
181 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
182 	};
183 
184 	struct list_head list;
185 	struct net_device *netdev;
186 	refcount_t refcount;
187 
188 	void *priv_ctx_tx;
189 	void *priv_ctx_rx;
190 
191 	u8 tx_conf:3;
192 	u8 rx_conf:3;
193 
194 	struct cipher_context tx;
195 	struct cipher_context rx;
196 
197 	struct scatterlist *partially_sent_record;
198 	u16 partially_sent_offset;
199 	unsigned long flags;
200 	bool in_tcp_sendpages;
201 
202 	u16 pending_open_record_frags;
203 	int (*push_pending_record)(struct sock *sk, int flags);
204 
205 	void (*sk_write_space)(struct sock *sk);
206 	void (*sk_destruct)(struct sock *sk);
207 	void (*sk_proto_close)(struct sock *sk, long timeout);
208 
209 	int  (*setsockopt)(struct sock *sk, int level,
210 			   int optname, char __user *optval,
211 			   unsigned int optlen);
212 	int  (*getsockopt)(struct sock *sk, int level,
213 			   int optname, char __user *optval,
214 			   int __user *optlen);
215 	int  (*hash)(struct sock *sk);
216 	void (*unhash)(struct sock *sk);
217 };
218 
219 struct tls_offload_context_rx {
220 	/* sw must be the first member of tls_offload_context_rx */
221 	struct tls_sw_context_rx sw;
222 	atomic64_t resync_req;
223 	u8 driver_state[];
224 	/* The TLS layer reserves room for driver specific state
225 	 * Currently the belief is that there is not enough
226 	 * driver specific state to justify another layer of indirection
227 	 */
228 };
229 
230 #define TLS_OFFLOAD_CONTEXT_SIZE_RX					\
231 	(ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
232 	 TLS_DRIVER_STATE_SIZE)
233 
234 int wait_on_pending_writer(struct sock *sk, long *timeo);
235 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
236 		int __user *optlen);
237 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
238 		  unsigned int optlen);
239 
240 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
241 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
242 int tls_sw_sendpage(struct sock *sk, struct page *page,
243 		    int offset, size_t size, int flags);
244 void tls_sw_close(struct sock *sk, long timeout);
245 void tls_sw_free_resources_tx(struct sock *sk);
246 void tls_sw_free_resources_rx(struct sock *sk);
247 void tls_sw_release_resources_rx(struct sock *sk);
248 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
249 		   int nonblock, int flags, int *addr_len);
250 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
251 			 struct poll_table_struct *wait);
252 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
253 			   struct pipe_inode_info *pipe,
254 			   size_t len, unsigned int flags);
255 
256 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
257 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
258 int tls_device_sendpage(struct sock *sk, struct page *page,
259 			int offset, size_t size, int flags);
260 void tls_device_sk_destruct(struct sock *sk);
261 void tls_device_init(void);
262 void tls_device_cleanup(void);
263 
264 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
265 				       u32 seq, u64 *p_record_sn);
266 
267 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
268 {
269 	return rec->len == 0;
270 }
271 
272 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
273 {
274 	return rec->end_seq - rec->len;
275 }
276 
277 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
278 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
279 		struct scatterlist *sg, u16 first_offset,
280 		int flags);
281 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
282 				   int flags, long *timeo);
283 
284 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
285 {
286 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
287 }
288 
289 static inline int tls_complete_pending_work(struct sock *sk,
290 					    struct tls_context *ctx,
291 					    int flags, long *timeo)
292 {
293 	int rc = 0;
294 
295 	if (unlikely(sk->sk_write_pending))
296 		rc = wait_on_pending_writer(sk, timeo);
297 
298 	if (!rc && tls_is_pending_closed_record(ctx))
299 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
300 
301 	return rc;
302 }
303 
304 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
305 {
306 	return !!ctx->partially_sent_record;
307 }
308 
309 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
310 {
311 	return tls_ctx->pending_open_record_frags;
312 }
313 
314 struct sk_buff *
315 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
316 		      struct sk_buff *skb);
317 
318 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
319 {
320 #ifdef CONFIG_SOCK_VALIDATE_XMIT
321 	return sk_fullsock(sk) &
322 	       (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
323 	       &tls_validate_xmit_skb);
324 #else
325 	return false;
326 #endif
327 }
328 
329 static inline void tls_err_abort(struct sock *sk, int err)
330 {
331 	sk->sk_err = err;
332 	sk->sk_error_report(sk);
333 }
334 
335 static inline bool tls_bigint_increment(unsigned char *seq, int len)
336 {
337 	int i;
338 
339 	for (i = len - 1; i >= 0; i--) {
340 		++seq[i];
341 		if (seq[i] != 0)
342 			break;
343 	}
344 
345 	return (i == -1);
346 }
347 
348 static inline void tls_advance_record_sn(struct sock *sk,
349 					 struct cipher_context *ctx)
350 {
351 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
352 		tls_err_abort(sk, EBADMSG);
353 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
354 			     ctx->iv_size);
355 }
356 
357 static inline void tls_fill_prepend(struct tls_context *ctx,
358 			     char *buf,
359 			     size_t plaintext_len,
360 			     unsigned char record_type)
361 {
362 	size_t pkt_len, iv_size = ctx->tx.iv_size;
363 
364 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
365 
366 	/* we cover nonce explicit here as well, so buf should be of
367 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
368 	 */
369 	buf[0] = record_type;
370 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
371 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
372 	/* we can use IV for nonce explicit according to spec */
373 	buf[3] = pkt_len >> 8;
374 	buf[4] = pkt_len & 0xFF;
375 	memcpy(buf + TLS_NONCE_OFFSET,
376 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
377 }
378 
379 static inline void tls_make_aad(char *buf,
380 				size_t size,
381 				char *record_sequence,
382 				int record_sequence_size,
383 				unsigned char record_type)
384 {
385 	memcpy(buf, record_sequence, record_sequence_size);
386 
387 	buf[8] = record_type;
388 	buf[9] = TLS_1_2_VERSION_MAJOR;
389 	buf[10] = TLS_1_2_VERSION_MINOR;
390 	buf[11] = size >> 8;
391 	buf[12] = size & 0xFF;
392 }
393 
394 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
395 {
396 	struct inet_connection_sock *icsk = inet_csk(sk);
397 
398 	return icsk->icsk_ulp_data;
399 }
400 
401 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
402 		const struct tls_context *tls_ctx)
403 {
404 	return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
405 }
406 
407 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
408 		const struct tls_context *tls_ctx)
409 {
410 	return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
411 }
412 
413 static inline struct tls_offload_context_tx *
414 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
415 {
416 	return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
417 }
418 
419 static inline struct tls_offload_context_rx *
420 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
421 {
422 	return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
423 }
424 
425 /* The TLS context is valid until sk_destruct is called */
426 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
427 {
428 	struct tls_context *tls_ctx = tls_get_ctx(sk);
429 	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
430 
431 	atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
432 }
433 
434 
435 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
436 		      unsigned char *record_type);
437 void tls_register_device(struct tls_device *device);
438 void tls_unregister_device(struct tls_device *device);
439 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
440 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
441 		struct scatterlist *sgout);
442 
443 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
444 				      struct net_device *dev,
445 				      struct sk_buff *skb);
446 
447 int tls_sw_fallback_init(struct sock *sk,
448 			 struct tls_offload_context_tx *offload_ctx,
449 			 struct tls_crypto_info *crypto_info);
450 
451 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
452 
453 void tls_device_offload_cleanup_rx(struct sock *sk);
454 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
455 
456 #endif /* _TLS_OFFLOAD_H */
457