xref: /openbmc/linux/include/net/tls.h (revision d2c43ff1)
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 
39 #include <uapi/linux/tls.h>
40 
41 
42 /* Maximum data size carried in a TLS record */
43 #define TLS_MAX_PAYLOAD_SIZE		((size_t)1 << 14)
44 
45 #define TLS_HEADER_SIZE			5
46 #define TLS_NONCE_OFFSET		TLS_HEADER_SIZE
47 
48 #define TLS_CRYPTO_INFO_READY(info)	((info)->cipher_type)
49 
50 #define TLS_RECORD_TYPE_DATA		0x17
51 
52 #define TLS_AAD_SPACE_SIZE		13
53 
54 struct tls_sw_context {
55 	struct crypto_aead *aead_send;
56 
57 	/* Sending context */
58 	char aad_space[TLS_AAD_SPACE_SIZE];
59 
60 	unsigned int sg_plaintext_size;
61 	int sg_plaintext_num_elem;
62 	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
63 
64 	unsigned int sg_encrypted_size;
65 	int sg_encrypted_num_elem;
66 	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
67 
68 	/* AAD | sg_plaintext_data | sg_tag */
69 	struct scatterlist sg_aead_in[2];
70 	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
71 	struct scatterlist sg_aead_out[2];
72 };
73 
74 enum {
75 	TLS_PENDING_CLOSED_RECORD
76 };
77 
78 struct tls_context {
79 	union {
80 		struct tls_crypto_info crypto_send;
81 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
82 	};
83 
84 	void *priv_ctx;
85 
86 	u16 prepend_size;
87 	u16 tag_size;
88 	u16 overhead_size;
89 	u16 iv_size;
90 	char *iv;
91 	u16 rec_seq_size;
92 	char *rec_seq;
93 
94 	struct scatterlist *partially_sent_record;
95 	u16 partially_sent_offset;
96 	unsigned long flags;
97 
98 	u16 pending_open_record_frags;
99 	int (*push_pending_record)(struct sock *sk, int flags);
100 	void (*free_resources)(struct sock *sk);
101 
102 	void (*sk_write_space)(struct sock *sk);
103 	void (*sk_proto_close)(struct sock *sk, long timeout);
104 
105 	int  (*setsockopt)(struct sock *sk, int level,
106 			   int optname, char __user *optval,
107 			   unsigned int optlen);
108 	int  (*getsockopt)(struct sock *sk, int level,
109 			   int optname, char __user *optval,
110 			   int __user *optlen);
111 };
112 
113 int wait_on_pending_writer(struct sock *sk, long *timeo);
114 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
115 		int __user *optlen);
116 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
117 		  unsigned int optlen);
118 
119 
120 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx);
121 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
122 int tls_sw_sendpage(struct sock *sk, struct page *page,
123 		    int offset, size_t size, int flags);
124 void tls_sw_close(struct sock *sk, long timeout);
125 
126 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
127 void tls_icsk_clean_acked(struct sock *sk);
128 
129 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
130 		struct scatterlist *sg, u16 first_offset,
131 		int flags);
132 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
133 				   int flags, long *timeo);
134 
135 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
136 {
137 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
138 }
139 
140 static inline int tls_complete_pending_work(struct sock *sk,
141 					    struct tls_context *ctx,
142 					    int flags, long *timeo)
143 {
144 	int rc = 0;
145 
146 	if (unlikely(sk->sk_write_pending))
147 		rc = wait_on_pending_writer(sk, timeo);
148 
149 	if (!rc && tls_is_pending_closed_record(ctx))
150 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
151 
152 	return rc;
153 }
154 
155 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
156 {
157 	return !!ctx->partially_sent_record;
158 }
159 
160 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
161 {
162 	return tls_ctx->pending_open_record_frags;
163 }
164 
165 static inline void tls_err_abort(struct sock *sk)
166 {
167 	sk->sk_err = -EBADMSG;
168 	sk->sk_error_report(sk);
169 }
170 
171 static inline bool tls_bigint_increment(unsigned char *seq, int len)
172 {
173 	int i;
174 
175 	for (i = len - 1; i >= 0; i--) {
176 		++seq[i];
177 		if (seq[i] != 0)
178 			break;
179 	}
180 
181 	return (i == -1);
182 }
183 
184 static inline void tls_advance_record_sn(struct sock *sk,
185 					 struct tls_context *ctx)
186 {
187 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
188 		tls_err_abort(sk);
189 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
190 			     ctx->iv_size);
191 }
192 
193 static inline void tls_fill_prepend(struct tls_context *ctx,
194 			     char *buf,
195 			     size_t plaintext_len,
196 			     unsigned char record_type)
197 {
198 	size_t pkt_len, iv_size = ctx->iv_size;
199 
200 	pkt_len = plaintext_len + iv_size + ctx->tag_size;
201 
202 	/* we cover nonce explicit here as well, so buf should be of
203 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
204 	 */
205 	buf[0] = record_type;
206 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
207 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
208 	/* we can use IV for nonce explicit according to spec */
209 	buf[3] = pkt_len >> 8;
210 	buf[4] = pkt_len & 0xFF;
211 	memcpy(buf + TLS_NONCE_OFFSET,
212 	       ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
213 }
214 
215 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
216 {
217 	struct inet_connection_sock *icsk = inet_csk(sk);
218 
219 	return icsk->icsk_ulp_data;
220 }
221 
222 static inline struct tls_sw_context *tls_sw_ctx(
223 		const struct tls_context *tls_ctx)
224 {
225 	return (struct tls_sw_context *)tls_ctx->priv_ctx;
226 }
227 
228 static inline struct tls_offload_context *tls_offload_ctx(
229 		const struct tls_context *tls_ctx)
230 {
231 	return (struct tls_offload_context *)tls_ctx->priv_ctx;
232 }
233 
234 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
235 		      unsigned char *record_type);
236 
237 #endif /* _TLS_OFFLOAD_H */
238