xref: /openbmc/linux/include/net/tls.h (revision 8bd1369b)
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 struct tls_sw_context_tx {
87 	struct crypto_aead *aead_send;
88 	struct crypto_wait async_wait;
89 
90 	char aad_space[TLS_AAD_SPACE_SIZE];
91 
92 	unsigned int sg_plaintext_size;
93 	int sg_plaintext_num_elem;
94 	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
95 
96 	unsigned int sg_encrypted_size;
97 	int sg_encrypted_num_elem;
98 	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
99 
100 	/* AAD | sg_plaintext_data | sg_tag */
101 	struct scatterlist sg_aead_in[2];
102 	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
103 	struct scatterlist sg_aead_out[2];
104 };
105 
106 struct tls_sw_context_rx {
107 	struct crypto_aead *aead_recv;
108 	struct crypto_wait async_wait;
109 
110 	struct strparser strp;
111 	void (*saved_data_ready)(struct sock *sk);
112 	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
113 				struct poll_table_struct *wait);
114 	struct sk_buff *recv_pkt;
115 	u8 control;
116 	bool decrypted;
117 
118 	char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
119 	char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];
120 
121 };
122 
123 struct tls_record_info {
124 	struct list_head list;
125 	u32 end_seq;
126 	int len;
127 	int num_frags;
128 	skb_frag_t frags[MAX_SKB_FRAGS];
129 };
130 
131 struct tls_offload_context {
132 	struct crypto_aead *aead_send;
133 	spinlock_t lock;	/* protects records list */
134 	struct list_head records_list;
135 	struct tls_record_info *open_record;
136 	struct tls_record_info *retransmit_hint;
137 	u64 hint_record_sn;
138 	u64 unacked_record_sn;
139 
140 	struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
141 	void (*sk_destruct)(struct sock *sk);
142 	u8 driver_state[];
143 	/* The TLS layer reserves room for driver specific state
144 	 * Currently the belief is that there is not enough
145 	 * driver specific state to justify another layer of indirection
146 	 */
147 #define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
148 };
149 
150 #define TLS_OFFLOAD_CONTEXT_SIZE                                               \
151 	(ALIGN(sizeof(struct tls_offload_context), sizeof(void *)) +           \
152 	 TLS_DRIVER_STATE_SIZE)
153 
154 enum {
155 	TLS_PENDING_CLOSED_RECORD
156 };
157 
158 struct cipher_context {
159 	u16 prepend_size;
160 	u16 tag_size;
161 	u16 overhead_size;
162 	u16 iv_size;
163 	char *iv;
164 	u16 rec_seq_size;
165 	char *rec_seq;
166 };
167 
168 struct tls_context {
169 	union {
170 		struct tls_crypto_info crypto_send;
171 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
172 	};
173 	union {
174 		struct tls_crypto_info crypto_recv;
175 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
176 	};
177 
178 	struct list_head list;
179 	struct net_device *netdev;
180 	refcount_t refcount;
181 
182 	void *priv_ctx_tx;
183 	void *priv_ctx_rx;
184 
185 	u8 tx_conf:3;
186 	u8 rx_conf:3;
187 
188 	struct cipher_context tx;
189 	struct cipher_context rx;
190 
191 	struct scatterlist *partially_sent_record;
192 	u16 partially_sent_offset;
193 	unsigned long flags;
194 	bool in_tcp_sendpages;
195 
196 	u16 pending_open_record_frags;
197 	int (*push_pending_record)(struct sock *sk, int flags);
198 
199 	void (*sk_write_space)(struct sock *sk);
200 	void (*sk_proto_close)(struct sock *sk, long timeout);
201 
202 	int  (*setsockopt)(struct sock *sk, int level,
203 			   int optname, char __user *optval,
204 			   unsigned int optlen);
205 	int  (*getsockopt)(struct sock *sk, int level,
206 			   int optname, char __user *optval,
207 			   int __user *optlen);
208 	int  (*hash)(struct sock *sk);
209 	void (*unhash)(struct sock *sk);
210 };
211 
212 int wait_on_pending_writer(struct sock *sk, long *timeo);
213 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
214 		int __user *optlen);
215 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
216 		  unsigned int optlen);
217 
218 
219 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
220 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
221 int tls_sw_sendpage(struct sock *sk, struct page *page,
222 		    int offset, size_t size, int flags);
223 void tls_sw_close(struct sock *sk, long timeout);
224 void tls_sw_free_resources_tx(struct sock *sk);
225 void tls_sw_free_resources_rx(struct sock *sk);
226 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
227 		   int nonblock, int flags, int *addr_len);
228 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
229 			 struct poll_table_struct *wait);
230 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
231 			   struct pipe_inode_info *pipe,
232 			   size_t len, unsigned int flags);
233 
234 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
235 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
236 int tls_device_sendpage(struct sock *sk, struct page *page,
237 			int offset, size_t size, int flags);
238 void tls_device_sk_destruct(struct sock *sk);
239 void tls_device_init(void);
240 void tls_device_cleanup(void);
241 
242 struct tls_record_info *tls_get_record(struct tls_offload_context *context,
243 				       u32 seq, u64 *p_record_sn);
244 
245 static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
246 {
247 	return rec->len == 0;
248 }
249 
250 static inline u32 tls_record_start_seq(struct tls_record_info *rec)
251 {
252 	return rec->end_seq - rec->len;
253 }
254 
255 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
256 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
257 		struct scatterlist *sg, u16 first_offset,
258 		int flags);
259 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
260 				   int flags, long *timeo);
261 
262 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
263 {
264 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
265 }
266 
267 static inline int tls_complete_pending_work(struct sock *sk,
268 					    struct tls_context *ctx,
269 					    int flags, long *timeo)
270 {
271 	int rc = 0;
272 
273 	if (unlikely(sk->sk_write_pending))
274 		rc = wait_on_pending_writer(sk, timeo);
275 
276 	if (!rc && tls_is_pending_closed_record(ctx))
277 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
278 
279 	return rc;
280 }
281 
282 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
283 {
284 	return !!ctx->partially_sent_record;
285 }
286 
287 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
288 {
289 	return tls_ctx->pending_open_record_frags;
290 }
291 
292 static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
293 {
294 	return sk_fullsock(sk) &&
295 	       /* matches smp_store_release in tls_set_device_offload */
296 	       smp_load_acquire(&sk->sk_destruct) == &tls_device_sk_destruct;
297 }
298 
299 static inline void tls_err_abort(struct sock *sk, int err)
300 {
301 	sk->sk_err = err;
302 	sk->sk_error_report(sk);
303 }
304 
305 static inline bool tls_bigint_increment(unsigned char *seq, int len)
306 {
307 	int i;
308 
309 	for (i = len - 1; i >= 0; i--) {
310 		++seq[i];
311 		if (seq[i] != 0)
312 			break;
313 	}
314 
315 	return (i == -1);
316 }
317 
318 static inline void tls_advance_record_sn(struct sock *sk,
319 					 struct cipher_context *ctx)
320 {
321 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
322 		tls_err_abort(sk, EBADMSG);
323 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
324 			     ctx->iv_size);
325 }
326 
327 static inline void tls_fill_prepend(struct tls_context *ctx,
328 			     char *buf,
329 			     size_t plaintext_len,
330 			     unsigned char record_type)
331 {
332 	size_t pkt_len, iv_size = ctx->tx.iv_size;
333 
334 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
335 
336 	/* we cover nonce explicit here as well, so buf should be of
337 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
338 	 */
339 	buf[0] = record_type;
340 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
341 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
342 	/* we can use IV for nonce explicit according to spec */
343 	buf[3] = pkt_len >> 8;
344 	buf[4] = pkt_len & 0xFF;
345 	memcpy(buf + TLS_NONCE_OFFSET,
346 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
347 }
348 
349 static inline void tls_make_aad(char *buf,
350 				size_t size,
351 				char *record_sequence,
352 				int record_sequence_size,
353 				unsigned char record_type)
354 {
355 	memcpy(buf, record_sequence, record_sequence_size);
356 
357 	buf[8] = record_type;
358 	buf[9] = TLS_1_2_VERSION_MAJOR;
359 	buf[10] = TLS_1_2_VERSION_MINOR;
360 	buf[11] = size >> 8;
361 	buf[12] = size & 0xFF;
362 }
363 
364 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
365 {
366 	struct inet_connection_sock *icsk = inet_csk(sk);
367 
368 	return icsk->icsk_ulp_data;
369 }
370 
371 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
372 		const struct tls_context *tls_ctx)
373 {
374 	return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
375 }
376 
377 static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
378 		const struct tls_context *tls_ctx)
379 {
380 	return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
381 }
382 
383 static inline struct tls_offload_context *tls_offload_ctx(
384 		const struct tls_context *tls_ctx)
385 {
386 	return (struct tls_offload_context *)tls_ctx->priv_ctx_tx;
387 }
388 
389 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
390 		      unsigned char *record_type);
391 void tls_register_device(struct tls_device *device);
392 void tls_unregister_device(struct tls_device *device);
393 
394 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
395 				      struct net_device *dev,
396 				      struct sk_buff *skb);
397 
398 int tls_sw_fallback_init(struct sock *sk,
399 			 struct tls_offload_context *offload_ctx,
400 			 struct tls_crypto_info *crypto_info);
401 
402 #endif /* _TLS_OFFLOAD_H */
403