xref: /openbmc/linux/net/tls/tls.h (revision fd0fc6fdd8896a195cb7b0210a5ee46774718fc8)
1 /*
2  * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
3  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
4  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #ifndef _TLS_INT_H
36 #define _TLS_INT_H
37 
38 #include <asm/byteorder.h>
39 #include <linux/types.h>
40 #include <linux/skmsg.h>
41 #include <net/tls.h>
42 #include <net/tls_prot.h>
43 
44 #define TLS_PAGE_ORDER	(min_t(unsigned int, PAGE_ALLOC_COSTLY_ORDER,	\
45 			       TLS_MAX_PAYLOAD_SIZE >> PAGE_SHIFT))
46 
47 #define __TLS_INC_STATS(net, field)				\
48 	__SNMP_INC_STATS((net)->mib.tls_statistics, field)
49 #define TLS_INC_STATS(net, field)				\
50 	SNMP_INC_STATS((net)->mib.tls_statistics, field)
51 #define TLS_DEC_STATS(net, field)				\
52 	SNMP_DEC_STATS((net)->mib.tls_statistics, field)
53 
54 struct tls_cipher_size_desc {
55 	unsigned int iv;
56 	unsigned int key;
57 	unsigned int salt;
58 	unsigned int tag;
59 	unsigned int rec_seq;
60 };
61 
62 extern const struct tls_cipher_size_desc tls_cipher_size_desc[];
63 
64 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
65  * allocated or mapped for each TLS record. After encryption, the records are
66  * stores in a linked list.
67  */
68 struct tls_rec {
69 	struct list_head list;
70 	int tx_ready;
71 	int tx_flags;
72 
73 	struct sk_msg msg_plaintext;
74 	struct sk_msg msg_encrypted;
75 
76 	/* AAD | msg_plaintext.sg.data | sg_tag */
77 	struct scatterlist sg_aead_in[2];
78 	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
79 	struct scatterlist sg_aead_out[2];
80 
81 	char content_type;
82 	struct scatterlist sg_content_type;
83 
84 	struct sock *sk;
85 
86 	char aad_space[TLS_AAD_SPACE_SIZE];
87 	u8 iv_data[MAX_IV_SIZE];
88 	struct aead_request aead_req;
89 	u8 aead_req_ctx[];
90 };
91 
92 int __net_init tls_proc_init(struct net *net);
93 void __net_exit tls_proc_fini(struct net *net);
94 
95 struct tls_context *tls_ctx_create(struct sock *sk);
96 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
97 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
98 
99 int wait_on_pending_writer(struct sock *sk, long *timeo);
100 void tls_err_abort(struct sock *sk, int err);
101 
102 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
103 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
104 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
105 void tls_sw_strparser_done(struct tls_context *tls_ctx);
106 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
107 void tls_sw_splice_eof(struct socket *sock);
108 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
109 void tls_sw_release_resources_tx(struct sock *sk);
110 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
111 void tls_sw_free_resources_rx(struct sock *sk);
112 void tls_sw_release_resources_rx(struct sock *sk);
113 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
114 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
115 		   int flags, int *addr_len);
116 bool tls_sw_sock_is_readable(struct sock *sk);
117 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
118 			   struct pipe_inode_info *pipe,
119 			   size_t len, unsigned int flags);
120 int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
121 		     sk_read_actor_t read_actor);
122 
123 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
124 void tls_device_splice_eof(struct socket *sock);
125 int tls_tx_records(struct sock *sk, int flags);
126 
127 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
128 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
129 
130 int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
131 		     unsigned char *record_type);
132 int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
133 
134 int tls_sw_fallback_init(struct sock *sk,
135 			 struct tls_offload_context_tx *offload_ctx,
136 			 struct tls_crypto_info *crypto_info);
137 
138 int tls_strp_dev_init(void);
139 void tls_strp_dev_exit(void);
140 
141 void tls_strp_done(struct tls_strparser *strp);
142 void tls_strp_stop(struct tls_strparser *strp);
143 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
144 void tls_strp_data_ready(struct tls_strparser *strp);
145 
146 void tls_strp_check_rcv(struct tls_strparser *strp);
147 void tls_strp_msg_done(struct tls_strparser *strp);
148 
149 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
150 void tls_rx_msg_ready(struct tls_strparser *strp);
151 
152 void tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
153 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
154 struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
155 int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
156 
157 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
158 {
159 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
160 
161 	return &scb->tls;
162 }
163 
164 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
165 {
166 	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
167 	return ctx->strp.anchor;
168 }
169 
170 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
171 {
172 	return ctx->strp.msg_ready;
173 }
174 
175 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
176 {
177 	return ctx->strp.mixed_decrypted;
178 }
179 
180 #ifdef CONFIG_TLS_DEVICE
181 int tls_device_init(void);
182 void tls_device_cleanup(void);
183 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
184 void tls_device_free_resources_tx(struct sock *sk);
185 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
186 void tls_device_offload_cleanup_rx(struct sock *sk);
187 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
188 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
189 #else
190 static inline int tls_device_init(void) { return 0; }
191 static inline void tls_device_cleanup(void) {}
192 
193 static inline int
194 tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
195 {
196 	return -EOPNOTSUPP;
197 }
198 
199 static inline void tls_device_free_resources_tx(struct sock *sk) {}
200 
201 static inline int
202 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
203 {
204 	return -EOPNOTSUPP;
205 }
206 
207 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
208 static inline void
209 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
210 
211 static inline int
212 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
213 {
214 	return 0;
215 }
216 #endif
217 
218 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
219 		struct scatterlist *sg, u16 first_offset,
220 		int flags);
221 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
222 			    int flags);
223 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
224 
225 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
226 {
227 	return !!ctx->partially_sent_record;
228 }
229 
230 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
231 {
232 	return tls_ctx->pending_open_record_frags;
233 }
234 
235 static inline bool tls_bigint_increment(unsigned char *seq, int len)
236 {
237 	int i;
238 
239 	for (i = len - 1; i >= 0; i--) {
240 		++seq[i];
241 		if (seq[i] != 0)
242 			break;
243 	}
244 
245 	return (i == -1);
246 }
247 
248 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
249 {
250 	u64 rcd_sn;
251 	__be64 *p;
252 
253 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
254 
255 	p = (__be64 *)seq;
256 	rcd_sn = be64_to_cpu(*p);
257 	*p = cpu_to_be64(rcd_sn - n);
258 }
259 
260 static inline void
261 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
262 		      struct cipher_context *ctx)
263 {
264 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
265 		tls_err_abort(sk, -EBADMSG);
266 
267 	if (prot->version != TLS_1_3_VERSION &&
268 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
269 		tls_bigint_increment(ctx->iv + prot->salt_size,
270 				     prot->iv_size);
271 }
272 
273 static inline void
274 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
275 {
276 	int i;
277 
278 	if (prot->version == TLS_1_3_VERSION ||
279 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
280 		for (i = 0; i < 8; i++)
281 			iv[i + 4] ^= seq[i];
282 	}
283 }
284 
285 static inline void
286 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
287 		 unsigned char record_type)
288 {
289 	struct tls_prot_info *prot = &ctx->prot_info;
290 	size_t pkt_len, iv_size = prot->iv_size;
291 
292 	pkt_len = plaintext_len + prot->tag_size;
293 	if (prot->version != TLS_1_3_VERSION &&
294 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
295 		pkt_len += iv_size;
296 
297 		memcpy(buf + TLS_NONCE_OFFSET,
298 		       ctx->tx.iv + prot->salt_size, iv_size);
299 	}
300 
301 	/* we cover nonce explicit here as well, so buf should be of
302 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
303 	 */
304 	buf[0] = prot->version == TLS_1_3_VERSION ?
305 		   TLS_RECORD_TYPE_DATA : record_type;
306 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
307 	buf[1] = TLS_1_2_VERSION_MINOR;
308 	buf[2] = TLS_1_2_VERSION_MAJOR;
309 	/* we can use IV for nonce explicit according to spec */
310 	buf[3] = pkt_len >> 8;
311 	buf[4] = pkt_len & 0xFF;
312 }
313 
314 static inline
315 void tls_make_aad(char *buf, size_t size, char *record_sequence,
316 		  unsigned char record_type, struct tls_prot_info *prot)
317 {
318 	if (prot->version != TLS_1_3_VERSION) {
319 		memcpy(buf, record_sequence, prot->rec_seq_size);
320 		buf += 8;
321 	} else {
322 		size += prot->tag_size;
323 	}
324 
325 	buf[0] = prot->version == TLS_1_3_VERSION ?
326 		  TLS_RECORD_TYPE_DATA : record_type;
327 	buf[1] = TLS_1_2_VERSION_MAJOR;
328 	buf[2] = TLS_1_2_VERSION_MINOR;
329 	buf[3] = size >> 8;
330 	buf[4] = size & 0xFF;
331 }
332 
333 #endif
334