xref: /linux/net/tls/tls.h (revision 35b1b538d422fd765d88fbdaaa6e06ee466d9f93)
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 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
55  * allocated or mapped for each TLS record. After encryption, the records are
56  * stores in a linked list.
57  */
58 struct tls_rec {
59 	struct list_head list;
60 	int tx_ready;
61 	int tx_flags;
62 
63 	struct sk_msg msg_plaintext;
64 	struct sk_msg msg_encrypted;
65 
66 	/* AAD | msg_plaintext.sg.data | sg_tag */
67 	struct scatterlist sg_aead_in[2];
68 	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
69 	struct scatterlist sg_aead_out[2];
70 
71 	char content_type;
72 	struct scatterlist sg_content_type;
73 
74 	struct sock *sk;
75 
76 	char aad_space[TLS_AAD_SPACE_SIZE];
77 	u8 iv_data[MAX_IV_SIZE];
78 	struct aead_request aead_req;
79 	u8 aead_req_ctx[];
80 };
81 
82 int __net_init tls_proc_init(struct net *net);
83 void __net_exit tls_proc_fini(struct net *net);
84 
85 struct tls_context *tls_ctx_create(struct sock *sk);
86 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
87 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
88 
89 int wait_on_pending_writer(struct sock *sk, long *timeo);
90 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
91 		 int __user *optlen);
92 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
93 		  unsigned int optlen);
94 void tls_err_abort(struct sock *sk, int err);
95 
96 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
97 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
98 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
99 void tls_sw_strparser_done(struct tls_context *tls_ctx);
100 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
101 void tls_sw_splice_eof(struct socket *sock);
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 void tls_device_splice_eof(struct socket *sock);
117 int tls_tx_records(struct sock *sk, int flags);
118 
119 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
120 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
121 
122 int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
123 		     unsigned char *record_type);
124 int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
125 
126 int tls_sw_fallback_init(struct sock *sk,
127 			 struct tls_offload_context_tx *offload_ctx,
128 			 struct tls_crypto_info *crypto_info);
129 
130 int tls_strp_dev_init(void);
131 void tls_strp_dev_exit(void);
132 
133 void tls_strp_done(struct tls_strparser *strp);
134 void tls_strp_stop(struct tls_strparser *strp);
135 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
136 void tls_strp_data_ready(struct tls_strparser *strp);
137 
138 void tls_strp_check_rcv(struct tls_strparser *strp);
139 void tls_strp_msg_done(struct tls_strparser *strp);
140 
141 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
142 void tls_rx_msg_ready(struct tls_strparser *strp);
143 
144 void tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
145 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
146 struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
147 int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
148 
149 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
150 {
151 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
152 
153 	return &scb->tls;
154 }
155 
156 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
157 {
158 	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
159 	return ctx->strp.anchor;
160 }
161 
162 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
163 {
164 	return ctx->strp.msg_ready;
165 }
166 
167 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
168 {
169 	return ctx->strp.mixed_decrypted;
170 }
171 
172 #ifdef CONFIG_TLS_DEVICE
173 int tls_device_init(void);
174 void tls_device_cleanup(void);
175 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
176 void tls_device_free_resources_tx(struct sock *sk);
177 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
178 void tls_device_offload_cleanup_rx(struct sock *sk);
179 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
180 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
181 #else
182 static inline int tls_device_init(void) { return 0; }
183 static inline void tls_device_cleanup(void) {}
184 
185 static inline int
186 tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
187 {
188 	return -EOPNOTSUPP;
189 }
190 
191 static inline void tls_device_free_resources_tx(struct sock *sk) {}
192 
193 static inline int
194 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
195 {
196 	return -EOPNOTSUPP;
197 }
198 
199 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
200 static inline void
201 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
202 
203 static inline int
204 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
205 {
206 	return 0;
207 }
208 #endif
209 
210 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
211 		struct scatterlist *sg, u16 first_offset,
212 		int flags);
213 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
214 			    int flags);
215 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
216 
217 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
218 {
219 	return !!ctx->partially_sent_record;
220 }
221 
222 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
223 {
224 	return tls_ctx->pending_open_record_frags;
225 }
226 
227 static inline bool tls_bigint_increment(unsigned char *seq, int len)
228 {
229 	int i;
230 
231 	for (i = len - 1; i >= 0; i--) {
232 		++seq[i];
233 		if (seq[i] != 0)
234 			break;
235 	}
236 
237 	return (i == -1);
238 }
239 
240 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
241 {
242 	u64 rcd_sn;
243 	__be64 *p;
244 
245 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
246 
247 	p = (__be64 *)seq;
248 	rcd_sn = be64_to_cpu(*p);
249 	*p = cpu_to_be64(rcd_sn - n);
250 }
251 
252 static inline void
253 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
254 		      struct cipher_context *ctx)
255 {
256 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
257 		tls_err_abort(sk, -EBADMSG);
258 
259 	if (prot->version != TLS_1_3_VERSION &&
260 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
261 		tls_bigint_increment(ctx->iv + prot->salt_size,
262 				     prot->iv_size);
263 }
264 
265 static inline void
266 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
267 {
268 	int i;
269 
270 	if (prot->version == TLS_1_3_VERSION ||
271 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
272 		for (i = 0; i < 8; i++)
273 			iv[i + 4] ^= seq[i];
274 	}
275 }
276 
277 static inline void
278 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
279 		 unsigned char record_type)
280 {
281 	struct tls_prot_info *prot = &ctx->prot_info;
282 	size_t pkt_len, iv_size = prot->iv_size;
283 
284 	pkt_len = plaintext_len + prot->tag_size;
285 	if (prot->version != TLS_1_3_VERSION &&
286 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
287 		pkt_len += iv_size;
288 
289 		memcpy(buf + TLS_NONCE_OFFSET,
290 		       ctx->tx.iv + prot->salt_size, iv_size);
291 	}
292 
293 	/* we cover nonce explicit here as well, so buf should be of
294 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
295 	 */
296 	buf[0] = prot->version == TLS_1_3_VERSION ?
297 		   TLS_RECORD_TYPE_DATA : record_type;
298 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
299 	buf[1] = TLS_1_2_VERSION_MINOR;
300 	buf[2] = TLS_1_2_VERSION_MAJOR;
301 	/* we can use IV for nonce explicit according to spec */
302 	buf[3] = pkt_len >> 8;
303 	buf[4] = pkt_len & 0xFF;
304 }
305 
306 static inline
307 void tls_make_aad(char *buf, size_t size, char *record_sequence,
308 		  unsigned char record_type, struct tls_prot_info *prot)
309 {
310 	if (prot->version != TLS_1_3_VERSION) {
311 		memcpy(buf, record_sequence, prot->rec_seq_size);
312 		buf += 8;
313 	} else {
314 		size += prot->tag_size;
315 	}
316 
317 	buf[0] = prot->version == TLS_1_3_VERSION ?
318 		  TLS_RECORD_TYPE_DATA : record_type;
319 	buf[1] = TLS_1_2_VERSION_MAJOR;
320 	buf[2] = TLS_1_2_VERSION_MINOR;
321 	buf[3] = size >> 8;
322 	buf[4] = size & 0xFF;
323 }
324 
325 #endif
326