xref: /linux/net/tls/tls.h (revision 4359a011e259a4608afc7fb3635370c9d4ba5943)
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 
43 #define TLS_PAGE_ORDER	(min_t(unsigned int, PAGE_ALLOC_COSTLY_ORDER,	\
44 			       TLS_MAX_PAYLOAD_SIZE >> PAGE_SHIFT))
45 
46 #define __TLS_INC_STATS(net, field)				\
47 	__SNMP_INC_STATS((net)->mib.tls_statistics, field)
48 #define TLS_INC_STATS(net, field)				\
49 	SNMP_INC_STATS((net)->mib.tls_statistics, field)
50 #define TLS_DEC_STATS(net, field)				\
51 	SNMP_DEC_STATS((net)->mib.tls_statistics, field)
52 
53 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
54  * allocated or mapped for each TLS record. After encryption, the records are
55  * stores in a linked list.
56  */
57 struct tls_rec {
58 	struct list_head list;
59 	int tx_ready;
60 	int tx_flags;
61 
62 	struct sk_msg msg_plaintext;
63 	struct sk_msg msg_encrypted;
64 
65 	/* AAD | msg_plaintext.sg.data | sg_tag */
66 	struct scatterlist sg_aead_in[2];
67 	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
68 	struct scatterlist sg_aead_out[2];
69 
70 	char content_type;
71 	struct scatterlist sg_content_type;
72 
73 	char aad_space[TLS_AAD_SPACE_SIZE];
74 	u8 iv_data[MAX_IV_SIZE];
75 	struct aead_request aead_req;
76 	u8 aead_req_ctx[];
77 };
78 
79 int __net_init tls_proc_init(struct net *net);
80 void __net_exit tls_proc_fini(struct net *net);
81 
82 struct tls_context *tls_ctx_create(struct sock *sk);
83 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
84 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
85 
86 int wait_on_pending_writer(struct sock *sk, long *timeo);
87 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
88 		 int __user *optlen);
89 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
90 		  unsigned int optlen);
91 void tls_err_abort(struct sock *sk, int err);
92 
93 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
94 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
95 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
96 void tls_sw_strparser_done(struct tls_context *tls_ctx);
97 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
98 int tls_sw_sendpage_locked(struct sock *sk, struct page *page,
99 			   int offset, size_t size, int flags);
100 int tls_sw_sendpage(struct sock *sk, struct page *page,
101 		    int offset, size_t size, int flags);
102 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
103 void tls_sw_release_resources_tx(struct sock *sk);
104 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
105 void tls_sw_free_resources_rx(struct sock *sk);
106 void tls_sw_release_resources_rx(struct sock *sk);
107 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
108 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
109 		   int flags, int *addr_len);
110 bool tls_sw_sock_is_readable(struct sock *sk);
111 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
112 			   struct pipe_inode_info *pipe,
113 			   size_t len, unsigned int flags);
114 
115 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
116 int tls_device_sendpage(struct sock *sk, struct page *page,
117 			int offset, size_t size, int flags);
118 int tls_tx_records(struct sock *sk, int flags);
119 
120 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
121 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
122 
123 int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
124 		     unsigned char *record_type);
125 int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
126 
127 int tls_sw_fallback_init(struct sock *sk,
128 			 struct tls_offload_context_tx *offload_ctx,
129 			 struct tls_crypto_info *crypto_info);
130 
131 int tls_strp_dev_init(void);
132 void tls_strp_dev_exit(void);
133 
134 void tls_strp_done(struct tls_strparser *strp);
135 void tls_strp_stop(struct tls_strparser *strp);
136 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
137 void tls_strp_data_ready(struct tls_strparser *strp);
138 
139 void tls_strp_check_rcv(struct tls_strparser *strp);
140 void tls_strp_msg_done(struct tls_strparser *strp);
141 
142 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
143 void tls_rx_msg_ready(struct tls_strparser *strp);
144 
145 void tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
146 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
147 struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
148 int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
149 
150 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
151 {
152 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
153 
154 	return &scb->tls;
155 }
156 
157 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
158 {
159 	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
160 	return ctx->strp.anchor;
161 }
162 
163 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
164 {
165 	return ctx->strp.msg_ready;
166 }
167 
168 #ifdef CONFIG_TLS_DEVICE
169 int tls_device_init(void);
170 void tls_device_cleanup(void);
171 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
172 void tls_device_free_resources_tx(struct sock *sk);
173 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
174 void tls_device_offload_cleanup_rx(struct sock *sk);
175 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
176 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
177 #else
178 static inline int tls_device_init(void) { return 0; }
179 static inline void tls_device_cleanup(void) {}
180 
181 static inline int
182 tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
183 {
184 	return -EOPNOTSUPP;
185 }
186 
187 static inline void tls_device_free_resources_tx(struct sock *sk) {}
188 
189 static inline int
190 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
191 {
192 	return -EOPNOTSUPP;
193 }
194 
195 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
196 static inline void
197 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
198 
199 static inline int
200 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
201 {
202 	return 0;
203 }
204 #endif
205 
206 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
207 		struct scatterlist *sg, u16 first_offset,
208 		int flags);
209 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
210 			    int flags);
211 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
212 
213 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
214 {
215 	return !!ctx->partially_sent_record;
216 }
217 
218 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
219 {
220 	return tls_ctx->pending_open_record_frags;
221 }
222 
223 static inline bool tls_bigint_increment(unsigned char *seq, int len)
224 {
225 	int i;
226 
227 	for (i = len - 1; i >= 0; i--) {
228 		++seq[i];
229 		if (seq[i] != 0)
230 			break;
231 	}
232 
233 	return (i == -1);
234 }
235 
236 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
237 {
238 	u64 rcd_sn;
239 	__be64 *p;
240 
241 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
242 
243 	p = (__be64 *)seq;
244 	rcd_sn = be64_to_cpu(*p);
245 	*p = cpu_to_be64(rcd_sn - n);
246 }
247 
248 static inline void
249 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
250 		      struct cipher_context *ctx)
251 {
252 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
253 		tls_err_abort(sk, -EBADMSG);
254 
255 	if (prot->version != TLS_1_3_VERSION &&
256 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
257 		tls_bigint_increment(ctx->iv + prot->salt_size,
258 				     prot->iv_size);
259 }
260 
261 static inline void
262 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
263 {
264 	int i;
265 
266 	if (prot->version == TLS_1_3_VERSION ||
267 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
268 		for (i = 0; i < 8; i++)
269 			iv[i + 4] ^= seq[i];
270 	}
271 }
272 
273 static inline void
274 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
275 		 unsigned char record_type)
276 {
277 	struct tls_prot_info *prot = &ctx->prot_info;
278 	size_t pkt_len, iv_size = prot->iv_size;
279 
280 	pkt_len = plaintext_len + prot->tag_size;
281 	if (prot->version != TLS_1_3_VERSION &&
282 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
283 		pkt_len += iv_size;
284 
285 		memcpy(buf + TLS_NONCE_OFFSET,
286 		       ctx->tx.iv + prot->salt_size, iv_size);
287 	}
288 
289 	/* we cover nonce explicit here as well, so buf should be of
290 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
291 	 */
292 	buf[0] = prot->version == TLS_1_3_VERSION ?
293 		   TLS_RECORD_TYPE_DATA : record_type;
294 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
295 	buf[1] = TLS_1_2_VERSION_MINOR;
296 	buf[2] = TLS_1_2_VERSION_MAJOR;
297 	/* we can use IV for nonce explicit according to spec */
298 	buf[3] = pkt_len >> 8;
299 	buf[4] = pkt_len & 0xFF;
300 }
301 
302 static inline
303 void tls_make_aad(char *buf, size_t size, char *record_sequence,
304 		  unsigned char record_type, struct tls_prot_info *prot)
305 {
306 	if (prot->version != TLS_1_3_VERSION) {
307 		memcpy(buf, record_sequence, prot->rec_seq_size);
308 		buf += 8;
309 	} else {
310 		size += prot->tag_size;
311 	}
312 
313 	buf[0] = prot->version == TLS_1_3_VERSION ?
314 		  TLS_RECORD_TYPE_DATA : record_type;
315 	buf[1] = TLS_1_2_VERSION_MAJOR;
316 	buf[2] = TLS_1_2_VERSION_MINOR;
317 	buf[3] = size >> 8;
318 	buf[4] = size & 0xFF;
319 }
320 
321 #endif
322