xref: /openbmc/linux/net/tls/tls.h (revision 5fb859f7)
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_INT_H
35 #define _TLS_INT_H
36 
37 #include <asm/byteorder.h>
38 #include <linux/types.h>
39 #include <linux/skmsg.h>
40 #include <net/tls.h>
41 
42 #define TLS_PAGE_ORDER	(min_t(unsigned int, PAGE_ALLOC_COSTLY_ORDER,	\
43 			       TLS_MAX_PAYLOAD_SIZE >> PAGE_SHIFT))
44 
45 #define __TLS_INC_STATS(net, field)				\
46 	__SNMP_INC_STATS((net)->mib.tls_statistics, field)
47 #define TLS_INC_STATS(net, field)				\
48 	SNMP_INC_STATS((net)->mib.tls_statistics, field)
49 #define TLS_DEC_STATS(net, field)				\
50 	SNMP_DEC_STATS((net)->mib.tls_statistics, field)
51 
52 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
53  * allocated or mapped for each TLS record. After encryption, the records are
54  * stores in a linked list.
55  */
56 struct tls_rec {
57 	struct list_head list;
58 	int tx_ready;
59 	int tx_flags;
60 
61 	struct sk_msg msg_plaintext;
62 	struct sk_msg msg_encrypted;
63 
64 	/* AAD | msg_plaintext.sg.data | sg_tag */
65 	struct scatterlist sg_aead_in[2];
66 	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
67 	struct scatterlist sg_aead_out[2];
68 
69 	char content_type;
70 	struct scatterlist sg_content_type;
71 
72 	char aad_space[TLS_AAD_SPACE_SIZE];
73 	u8 iv_data[MAX_IV_SIZE];
74 	struct aead_request aead_req;
75 	u8 aead_req_ctx[];
76 };
77 
78 int __net_init tls_proc_init(struct net *net);
79 void __net_exit tls_proc_fini(struct net *net);
80 
81 struct tls_context *tls_ctx_create(struct sock *sk);
82 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
83 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
84 
85 int wait_on_pending_writer(struct sock *sk, long *timeo);
86 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
87 		 int __user *optlen);
88 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
89 		  unsigned int optlen);
90 void tls_err_abort(struct sock *sk, int err);
91 
92 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
93 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
94 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
95 void tls_sw_strparser_done(struct tls_context *tls_ctx);
96 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
97 int tls_sw_sendpage_locked(struct sock *sk, struct page *page,
98 			   int offset, size_t size, int flags);
99 int tls_sw_sendpage(struct sock *sk, struct page *page,
100 		    int offset, size_t size, int flags);
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 
114 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
115 int tls_device_sendpage(struct sock *sk, struct page *page,
116 			int offset, size_t size, int flags);
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_msg_hold(struct sock *sk, struct sk_buff *skb,
131 		      struct sk_buff_head *dst);
132 
133 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
134 {
135 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
136 
137 	return &scb->tls;
138 }
139 
140 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
141 {
142 	return ctx->recv_pkt;
143 }
144 
145 #ifdef CONFIG_TLS_DEVICE
146 int tls_device_init(void);
147 void tls_device_cleanup(void);
148 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
149 void tls_device_free_resources_tx(struct sock *sk);
150 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
151 void tls_device_offload_cleanup_rx(struct sock *sk);
152 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
153 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
154 #else
155 static inline int tls_device_init(void) { return 0; }
156 static inline void tls_device_cleanup(void) {}
157 
158 static inline int
159 tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
160 {
161 	return -EOPNOTSUPP;
162 }
163 
164 static inline void tls_device_free_resources_tx(struct sock *sk) {}
165 
166 static inline int
167 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
168 {
169 	return -EOPNOTSUPP;
170 }
171 
172 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
173 static inline void
174 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
175 
176 static inline int
177 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
178 {
179 	return 0;
180 }
181 #endif
182 
183 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
184 		struct scatterlist *sg, u16 first_offset,
185 		int flags);
186 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
187 			    int flags);
188 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
189 
190 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
191 {
192 	return !!ctx->partially_sent_record;
193 }
194 
195 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
196 {
197 	return tls_ctx->pending_open_record_frags;
198 }
199 
200 static inline bool tls_bigint_increment(unsigned char *seq, int len)
201 {
202 	int i;
203 
204 	for (i = len - 1; i >= 0; i--) {
205 		++seq[i];
206 		if (seq[i] != 0)
207 			break;
208 	}
209 
210 	return (i == -1);
211 }
212 
213 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
214 {
215 	u64 rcd_sn;
216 	__be64 *p;
217 
218 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
219 
220 	p = (__be64 *)seq;
221 	rcd_sn = be64_to_cpu(*p);
222 	*p = cpu_to_be64(rcd_sn - n);
223 }
224 
225 static inline void
226 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
227 		      struct cipher_context *ctx)
228 {
229 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
230 		tls_err_abort(sk, -EBADMSG);
231 
232 	if (prot->version != TLS_1_3_VERSION &&
233 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
234 		tls_bigint_increment(ctx->iv + prot->salt_size,
235 				     prot->iv_size);
236 }
237 
238 static inline void
239 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
240 {
241 	int i;
242 
243 	if (prot->version == TLS_1_3_VERSION ||
244 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
245 		for (i = 0; i < 8; i++)
246 			iv[i + 4] ^= seq[i];
247 	}
248 }
249 
250 static inline void
251 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
252 		 unsigned char record_type)
253 {
254 	struct tls_prot_info *prot = &ctx->prot_info;
255 	size_t pkt_len, iv_size = prot->iv_size;
256 
257 	pkt_len = plaintext_len + prot->tag_size;
258 	if (prot->version != TLS_1_3_VERSION &&
259 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
260 		pkt_len += iv_size;
261 
262 		memcpy(buf + TLS_NONCE_OFFSET,
263 		       ctx->tx.iv + prot->salt_size, iv_size);
264 	}
265 
266 	/* we cover nonce explicit here as well, so buf should be of
267 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
268 	 */
269 	buf[0] = prot->version == TLS_1_3_VERSION ?
270 		   TLS_RECORD_TYPE_DATA : record_type;
271 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
272 	buf[1] = TLS_1_2_VERSION_MINOR;
273 	buf[2] = TLS_1_2_VERSION_MAJOR;
274 	/* we can use IV for nonce explicit according to spec */
275 	buf[3] = pkt_len >> 8;
276 	buf[4] = pkt_len & 0xFF;
277 }
278 
279 static inline
280 void tls_make_aad(char *buf, size_t size, char *record_sequence,
281 		  unsigned char record_type, struct tls_prot_info *prot)
282 {
283 	if (prot->version != TLS_1_3_VERSION) {
284 		memcpy(buf, record_sequence, prot->rec_seq_size);
285 		buf += 8;
286 	} else {
287 		size += prot->tag_size;
288 	}
289 
290 	buf[0] = prot->version == TLS_1_3_VERSION ?
291 		  TLS_RECORD_TYPE_DATA : record_type;
292 	buf[1] = TLS_1_2_VERSION_MAJOR;
293 	buf[2] = TLS_1_2_VERSION_MINOR;
294 	buf[3] = size >> 8;
295 	buf[4] = size & 0xFF;
296 }
297 
298 #endif
299