xref: /openbmc/linux/net/tls/tls.h (revision 662fbcec32f4af6bdcf5b4006b792ebe9543d945)
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 	struct sock *sk;
74 
75 	char aad_space[TLS_AAD_SPACE_SIZE];
76 	u8 iv_data[MAX_IV_SIZE];
77 	struct aead_request aead_req;
78 	u8 aead_req_ctx[];
79 };
80 
81 int __net_init tls_proc_init(struct net *net);
82 void __net_exit tls_proc_fini(struct net *net);
83 
84 struct tls_context *tls_ctx_create(struct sock *sk);
85 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
86 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
87 
88 int wait_on_pending_writer(struct sock *sk, long *timeo);
89 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
90 		 int __user *optlen);
91 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
92 		  unsigned int optlen);
93 void tls_err_abort(struct sock *sk, int err);
94 
95 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
96 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
97 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
98 void tls_sw_strparser_done(struct tls_context *tls_ctx);
99 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
100 void tls_sw_splice_eof(struct socket *sock);
101 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
102 void tls_sw_release_resources_tx(struct sock *sk);
103 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
104 void tls_sw_free_resources_rx(struct sock *sk);
105 void tls_sw_release_resources_rx(struct sock *sk);
106 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
107 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
108 		   int flags, int *addr_len);
109 bool tls_sw_sock_is_readable(struct sock *sk);
110 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
111 			   struct pipe_inode_info *pipe,
112 			   size_t len, unsigned int flags);
113 int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
114 		     sk_read_actor_t read_actor);
115 
116 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
117 void tls_device_splice_eof(struct socket *sock);
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 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
169 {
170 	return ctx->strp.mixed_decrypted;
171 }
172 
173 #ifdef CONFIG_TLS_DEVICE
174 int tls_device_init(void);
175 void tls_device_cleanup(void);
176 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
177 void tls_device_free_resources_tx(struct sock *sk);
178 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
179 void tls_device_offload_cleanup_rx(struct sock *sk);
180 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
181 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
182 #else
183 static inline int tls_device_init(void) { return 0; }
184 static inline void tls_device_cleanup(void) {}
185 
186 static inline int
187 tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
188 {
189 	return -EOPNOTSUPP;
190 }
191 
192 static inline void tls_device_free_resources_tx(struct sock *sk) {}
193 
194 static inline int
195 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
196 {
197 	return -EOPNOTSUPP;
198 }
199 
200 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
201 static inline void
202 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
203 
204 static inline int
205 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
206 {
207 	return 0;
208 }
209 #endif
210 
211 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
212 		struct scatterlist *sg, u16 first_offset,
213 		int flags);
214 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
215 			    int flags);
216 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
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 bool tls_bigint_increment(unsigned char *seq, int len)
229 {
230 	int i;
231 
232 	for (i = len - 1; i >= 0; i--) {
233 		++seq[i];
234 		if (seq[i] != 0)
235 			break;
236 	}
237 
238 	return (i == -1);
239 }
240 
241 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
242 {
243 	u64 rcd_sn;
244 	__be64 *p;
245 
246 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
247 
248 	p = (__be64 *)seq;
249 	rcd_sn = be64_to_cpu(*p);
250 	*p = cpu_to_be64(rcd_sn - n);
251 }
252 
253 static inline void
254 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
255 		      struct cipher_context *ctx)
256 {
257 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
258 		tls_err_abort(sk, -EBADMSG);
259 
260 	if (prot->version != TLS_1_3_VERSION &&
261 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
262 		tls_bigint_increment(ctx->iv + prot->salt_size,
263 				     prot->iv_size);
264 }
265 
266 static inline void
267 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
268 {
269 	int i;
270 
271 	if (prot->version == TLS_1_3_VERSION ||
272 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
273 		for (i = 0; i < 8; i++)
274 			iv[i + 4] ^= seq[i];
275 	}
276 }
277 
278 static inline void
279 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
280 		 unsigned char record_type)
281 {
282 	struct tls_prot_info *prot = &ctx->prot_info;
283 	size_t pkt_len, iv_size = prot->iv_size;
284 
285 	pkt_len = plaintext_len + prot->tag_size;
286 	if (prot->version != TLS_1_3_VERSION &&
287 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
288 		pkt_len += iv_size;
289 
290 		memcpy(buf + TLS_NONCE_OFFSET,
291 		       ctx->tx.iv + prot->salt_size, iv_size);
292 	}
293 
294 	/* we cover nonce explicit here as well, so buf should be of
295 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
296 	 */
297 	buf[0] = prot->version == TLS_1_3_VERSION ?
298 		   TLS_RECORD_TYPE_DATA : record_type;
299 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
300 	buf[1] = TLS_1_2_VERSION_MINOR;
301 	buf[2] = TLS_1_2_VERSION_MAJOR;
302 	/* we can use IV for nonce explicit according to spec */
303 	buf[3] = pkt_len >> 8;
304 	buf[4] = pkt_len & 0xFF;
305 }
306 
307 static inline
308 void tls_make_aad(char *buf, size_t size, char *record_sequence,
309 		  unsigned char record_type, struct tls_prot_info *prot)
310 {
311 	if (prot->version != TLS_1_3_VERSION) {
312 		memcpy(buf, record_sequence, prot->rec_seq_size);
313 		buf += 8;
314 	} else {
315 		size += prot->tag_size;
316 	}
317 
318 	buf[0] = prot->version == TLS_1_3_VERSION ?
319 		  TLS_RECORD_TYPE_DATA : record_type;
320 	buf[1] = TLS_1_2_VERSION_MAJOR;
321 	buf[2] = TLS_1_2_VERSION_MINOR;
322 	buf[3] = size >> 8;
323 	buf[4] = size & 0xFF;
324 }
325 
326 #endif
327