xref: /openbmc/linux/include/net/tls.h (revision a17922de)
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 	char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
129 	char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];
130 
131 };
132 
133 struct tls_record_info {
134 	struct list_head list;
135 	u32 end_seq;
136 	int len;
137 	int num_frags;
138 	skb_frag_t frags[MAX_SKB_FRAGS];
139 };
140 
141 struct tls_offload_context_tx {
142 	struct crypto_aead *aead_send;
143 	spinlock_t lock;	/* protects records list */
144 	struct list_head records_list;
145 	struct tls_record_info *open_record;
146 	struct tls_record_info *retransmit_hint;
147 	u64 hint_record_sn;
148 	u64 unacked_record_sn;
149 
150 	struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
151 	void (*sk_destruct)(struct sock *sk);
152 	u8 driver_state[];
153 	/* The TLS layer reserves room for driver specific state
154 	 * Currently the belief is that there is not enough
155 	 * driver specific state to justify another layer of indirection
156 	 */
157 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
158 };
159 
160 #define TLS_OFFLOAD_CONTEXT_SIZE_TX                                            \
161 	(ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
162 	 TLS_DRIVER_STATE_SIZE)
163 
164 enum {
165 	TLS_PENDING_CLOSED_RECORD
166 };
167 
168 struct cipher_context {
169 	u16 prepend_size;
170 	u16 tag_size;
171 	u16 overhead_size;
172 	u16 iv_size;
173 	char *iv;
174 	u16 rec_seq_size;
175 	char *rec_seq;
176 };
177 
178 struct tls_context {
179 	union {
180 		struct tls_crypto_info crypto_send;
181 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
182 	};
183 	union {
184 		struct tls_crypto_info crypto_recv;
185 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
186 	};
187 
188 	struct list_head list;
189 	struct net_device *netdev;
190 	refcount_t refcount;
191 
192 	void *priv_ctx_tx;
193 	void *priv_ctx_rx;
194 
195 	u8 tx_conf:3;
196 	u8 rx_conf:3;
197 
198 	struct cipher_context tx;
199 	struct cipher_context rx;
200 
201 	struct scatterlist *partially_sent_record;
202 	u16 partially_sent_offset;
203 	unsigned long flags;
204 	bool in_tcp_sendpages;
205 
206 	u16 pending_open_record_frags;
207 	int (*push_pending_record)(struct sock *sk, int flags);
208 
209 	void (*sk_write_space)(struct sock *sk);
210 	void (*sk_destruct)(struct sock *sk);
211 	void (*sk_proto_close)(struct sock *sk, long timeout);
212 
213 	int  (*setsockopt)(struct sock *sk, int level,
214 			   int optname, char __user *optval,
215 			   unsigned int optlen);
216 	int  (*getsockopt)(struct sock *sk, int level,
217 			   int optname, char __user *optval,
218 			   int __user *optlen);
219 	int  (*hash)(struct sock *sk);
220 	void (*unhash)(struct sock *sk);
221 };
222 
223 struct tls_offload_context_rx {
224 	/* sw must be the first member of tls_offload_context_rx */
225 	struct tls_sw_context_rx sw;
226 	atomic64_t resync_req;
227 	u8 driver_state[];
228 	/* The TLS layer reserves room for driver specific state
229 	 * Currently the belief is that there is not enough
230 	 * driver specific state to justify another layer of indirection
231 	 */
232 };
233 
234 #define TLS_OFFLOAD_CONTEXT_SIZE_RX					\
235 	(ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
236 	 TLS_DRIVER_STATE_SIZE)
237 
238 int wait_on_pending_writer(struct sock *sk, long *timeo);
239 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
240 		int __user *optlen);
241 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
242 		  unsigned int optlen);
243 
244 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
245 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
246 int tls_sw_sendpage(struct sock *sk, struct page *page,
247 		    int offset, size_t size, int flags);
248 void tls_sw_close(struct sock *sk, long timeout);
249 void tls_sw_free_resources_tx(struct sock *sk);
250 void tls_sw_free_resources_rx(struct sock *sk);
251 void tls_sw_release_resources_rx(struct sock *sk);
252 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
253 		   int nonblock, int flags, int *addr_len);
254 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
255 			 struct poll_table_struct *wait);
256 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
257 			   struct pipe_inode_info *pipe,
258 			   size_t len, unsigned int flags);
259 
260 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
261 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
262 int tls_device_sendpage(struct sock *sk, struct page *page,
263 			int offset, size_t size, int flags);
264 void tls_device_sk_destruct(struct sock *sk);
265 void tls_device_init(void);
266 void tls_device_cleanup(void);
267 
268 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
269 				       u32 seq, u64 *p_record_sn);
270 
271 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
272 {
273 	return rec->len == 0;
274 }
275 
276 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
277 {
278 	return rec->end_seq - rec->len;
279 }
280 
281 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
282 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
283 		struct scatterlist *sg, u16 first_offset,
284 		int flags);
285 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
286 				   int flags, long *timeo);
287 
288 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
289 {
290 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
291 }
292 
293 static inline int tls_complete_pending_work(struct sock *sk,
294 					    struct tls_context *ctx,
295 					    int flags, long *timeo)
296 {
297 	int rc = 0;
298 
299 	if (unlikely(sk->sk_write_pending))
300 		rc = wait_on_pending_writer(sk, timeo);
301 
302 	if (!rc && tls_is_pending_closed_record(ctx))
303 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
304 
305 	return rc;
306 }
307 
308 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
309 {
310 	return !!ctx->partially_sent_record;
311 }
312 
313 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
314 {
315 	return tls_ctx->pending_open_record_frags;
316 }
317 
318 struct sk_buff *
319 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
320 		      struct sk_buff *skb);
321 
322 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
323 {
324 #ifdef CONFIG_SOCK_VALIDATE_XMIT
325 	return sk_fullsock(sk) &
326 	       (smp_load_acquire(&sk->sk_validate_xmit_skb) ==
327 	       &tls_validate_xmit_skb);
328 #else
329 	return false;
330 #endif
331 }
332 
333 static inline void tls_err_abort(struct sock *sk, int err)
334 {
335 	sk->sk_err = err;
336 	sk->sk_error_report(sk);
337 }
338 
339 static inline bool tls_bigint_increment(unsigned char *seq, int len)
340 {
341 	int i;
342 
343 	for (i = len - 1; i >= 0; i--) {
344 		++seq[i];
345 		if (seq[i] != 0)
346 			break;
347 	}
348 
349 	return (i == -1);
350 }
351 
352 static inline void tls_advance_record_sn(struct sock *sk,
353 					 struct cipher_context *ctx)
354 {
355 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
356 		tls_err_abort(sk, EBADMSG);
357 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
358 			     ctx->iv_size);
359 }
360 
361 static inline void tls_fill_prepend(struct tls_context *ctx,
362 			     char *buf,
363 			     size_t plaintext_len,
364 			     unsigned char record_type)
365 {
366 	size_t pkt_len, iv_size = ctx->tx.iv_size;
367 
368 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
369 
370 	/* we cover nonce explicit here as well, so buf should be of
371 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
372 	 */
373 	buf[0] = record_type;
374 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
375 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
376 	/* we can use IV for nonce explicit according to spec */
377 	buf[3] = pkt_len >> 8;
378 	buf[4] = pkt_len & 0xFF;
379 	memcpy(buf + TLS_NONCE_OFFSET,
380 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
381 }
382 
383 static inline void tls_make_aad(char *buf,
384 				size_t size,
385 				char *record_sequence,
386 				int record_sequence_size,
387 				unsigned char record_type)
388 {
389 	memcpy(buf, record_sequence, record_sequence_size);
390 
391 	buf[8] = record_type;
392 	buf[9] = TLS_1_2_VERSION_MAJOR;
393 	buf[10] = TLS_1_2_VERSION_MINOR;
394 	buf[11] = size >> 8;
395 	buf[12] = size & 0xFF;
396 }
397 
398 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
399 {
400 	struct inet_connection_sock *icsk = inet_csk(sk);
401 
402 	return icsk->icsk_ulp_data;
403 }
404 
405 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
406 		const struct tls_context *tls_ctx)
407 {
408 	return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
409 }
410 
411 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
412 		const struct tls_context *tls_ctx)
413 {
414 	return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
415 }
416 
417 static inline struct tls_offload_context_tx *
418 tls_offload_ctx_tx(const struct tls_context *tls_ctx)
419 {
420 	return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
421 }
422 
423 static inline struct tls_offload_context_rx *
424 tls_offload_ctx_rx(const struct tls_context *tls_ctx)
425 {
426 	return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
427 }
428 
429 /* The TLS context is valid until sk_destruct is called */
430 static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
431 {
432 	struct tls_context *tls_ctx = tls_get_ctx(sk);
433 	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
434 
435 	atomic64_set(&rx_ctx->resync_req, ((((uint64_t)seq) << 32) | 1));
436 }
437 
438 
439 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
440 		      unsigned char *record_type);
441 void tls_register_device(struct tls_device *device);
442 void tls_unregister_device(struct tls_device *device);
443 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb);
444 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
445 		struct scatterlist *sgout);
446 
447 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
448 				      struct net_device *dev,
449 				      struct sk_buff *skb);
450 
451 int tls_sw_fallback_init(struct sock *sk,
452 			 struct tls_offload_context_tx *offload_ctx,
453 			 struct tls_crypto_info *crypto_info);
454 
455 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
456 
457 void tls_device_offload_cleanup_rx(struct sock *sk);
458 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
459 
460 #endif /* _TLS_OFFLOAD_H */
461