xref: /linux/include/net/tls.h (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
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 {
87 	struct crypto_aead *aead_send;
88 	struct crypto_aead *aead_recv;
89 	struct crypto_wait async_wait;
90 
91 	/* Receive context */
92 	struct strparser strp;
93 	void (*saved_data_ready)(struct sock *sk);
94 	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
95 				struct poll_table_struct *wait);
96 	struct sk_buff *recv_pkt;
97 	u8 control;
98 	bool decrypted;
99 
100 	/* Sending context */
101 	char aad_space[TLS_AAD_SPACE_SIZE];
102 
103 	unsigned int sg_plaintext_size;
104 	int sg_plaintext_num_elem;
105 	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
106 
107 	unsigned int sg_encrypted_size;
108 	int sg_encrypted_num_elem;
109 	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
110 
111 	/* AAD | sg_plaintext_data | sg_tag */
112 	struct scatterlist sg_aead_in[2];
113 	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
114 	struct scatterlist sg_aead_out[2];
115 };
116 
117 enum {
118 	TLS_PENDING_CLOSED_RECORD
119 };
120 
121 struct cipher_context {
122 	u16 prepend_size;
123 	u16 tag_size;
124 	u16 overhead_size;
125 	u16 iv_size;
126 	char *iv;
127 	u16 rec_seq_size;
128 	char *rec_seq;
129 };
130 
131 struct tls_context {
132 	union {
133 		struct tls_crypto_info crypto_send;
134 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
135 	};
136 	union {
137 		struct tls_crypto_info crypto_recv;
138 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
139 	};
140 
141 	void *priv_ctx;
142 
143 	u8 conf:3;
144 
145 	struct cipher_context tx;
146 	struct cipher_context rx;
147 
148 	struct scatterlist *partially_sent_record;
149 	u16 partially_sent_offset;
150 	unsigned long flags;
151 
152 	u16 pending_open_record_frags;
153 	int (*push_pending_record)(struct sock *sk, int flags);
154 
155 	void (*sk_write_space)(struct sock *sk);
156 	void (*sk_proto_close)(struct sock *sk, long timeout);
157 
158 	int  (*setsockopt)(struct sock *sk, int level,
159 			   int optname, char __user *optval,
160 			   unsigned int optlen);
161 	int  (*getsockopt)(struct sock *sk, int level,
162 			   int optname, char __user *optval,
163 			   int __user *optlen);
164 	int  (*hash)(struct sock *sk);
165 	void (*unhash)(struct sock *sk);
166 };
167 
168 int wait_on_pending_writer(struct sock *sk, long *timeo);
169 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
170 		int __user *optlen);
171 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
172 		  unsigned int optlen);
173 
174 
175 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
176 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
177 int tls_sw_sendpage(struct sock *sk, struct page *page,
178 		    int offset, size_t size, int flags);
179 void tls_sw_close(struct sock *sk, long timeout);
180 void tls_sw_free_resources(struct sock *sk);
181 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
182 		   int nonblock, int flags, int *addr_len);
183 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
184 			 struct poll_table_struct *wait);
185 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
186 			   struct pipe_inode_info *pipe,
187 			   size_t len, unsigned int flags);
188 
189 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
190 void tls_icsk_clean_acked(struct sock *sk);
191 
192 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
193 		struct scatterlist *sg, u16 first_offset,
194 		int flags);
195 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
196 				   int flags, long *timeo);
197 
198 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
199 {
200 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
201 }
202 
203 static inline int tls_complete_pending_work(struct sock *sk,
204 					    struct tls_context *ctx,
205 					    int flags, long *timeo)
206 {
207 	int rc = 0;
208 
209 	if (unlikely(sk->sk_write_pending))
210 		rc = wait_on_pending_writer(sk, timeo);
211 
212 	if (!rc && tls_is_pending_closed_record(ctx))
213 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
214 
215 	return rc;
216 }
217 
218 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
219 {
220 	return !!ctx->partially_sent_record;
221 }
222 
223 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
224 {
225 	return tls_ctx->pending_open_record_frags;
226 }
227 
228 static inline void tls_err_abort(struct sock *sk, int err)
229 {
230 	sk->sk_err = err;
231 	sk->sk_error_report(sk);
232 }
233 
234 static inline bool tls_bigint_increment(unsigned char *seq, int len)
235 {
236 	int i;
237 
238 	for (i = len - 1; i >= 0; i--) {
239 		++seq[i];
240 		if (seq[i] != 0)
241 			break;
242 	}
243 
244 	return (i == -1);
245 }
246 
247 static inline void tls_advance_record_sn(struct sock *sk,
248 					 struct cipher_context *ctx)
249 {
250 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
251 		tls_err_abort(sk, EBADMSG);
252 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
253 			     ctx->iv_size);
254 }
255 
256 static inline void tls_fill_prepend(struct tls_context *ctx,
257 			     char *buf,
258 			     size_t plaintext_len,
259 			     unsigned char record_type)
260 {
261 	size_t pkt_len, iv_size = ctx->tx.iv_size;
262 
263 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
264 
265 	/* we cover nonce explicit here as well, so buf should be of
266 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
267 	 */
268 	buf[0] = record_type;
269 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
270 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
271 	/* we can use IV for nonce explicit according to spec */
272 	buf[3] = pkt_len >> 8;
273 	buf[4] = pkt_len & 0xFF;
274 	memcpy(buf + TLS_NONCE_OFFSET,
275 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
276 }
277 
278 static inline void tls_make_aad(char *buf,
279 				size_t size,
280 				char *record_sequence,
281 				int record_sequence_size,
282 				unsigned char record_type)
283 {
284 	memcpy(buf, record_sequence, record_sequence_size);
285 
286 	buf[8] = record_type;
287 	buf[9] = TLS_1_2_VERSION_MAJOR;
288 	buf[10] = TLS_1_2_VERSION_MINOR;
289 	buf[11] = size >> 8;
290 	buf[12] = size & 0xFF;
291 }
292 
293 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
294 {
295 	struct inet_connection_sock *icsk = inet_csk(sk);
296 
297 	return icsk->icsk_ulp_data;
298 }
299 
300 static inline struct tls_sw_context *tls_sw_ctx(
301 		const struct tls_context *tls_ctx)
302 {
303 	return (struct tls_sw_context *)tls_ctx->priv_ctx;
304 }
305 
306 static inline struct tls_offload_context *tls_offload_ctx(
307 		const struct tls_context *tls_ctx)
308 {
309 	return (struct tls_offload_context *)tls_ctx->priv_ctx;
310 }
311 
312 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
313 		      unsigned char *record_type);
314 void tls_register_device(struct tls_device *device);
315 void tls_unregister_device(struct tls_device *device);
316 
317 #endif /* _TLS_OFFLOAD_H */
318