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_OFFLOAD_H
 35#define _TLS_OFFLOAD_H
 36
 37#include <linux/types.h>
 38#include <asm/byteorder.h>
 39#include <linux/crypto.h>
 40#include <linux/socket.h>
 41#include <linux/tcp.h>
 42#include <net/tcp.h>
 43#include <net/strparser.h>
 44
 45#include <uapi/linux/tls.h>
 46
 47
 48/* Maximum data size carried in a TLS record */
 49#define TLS_MAX_PAYLOAD_SIZE		((size_t)1 << 14)
 50
 51#define TLS_HEADER_SIZE			5
 52#define TLS_NONCE_OFFSET		TLS_HEADER_SIZE
 53
 54#define TLS_CRYPTO_INFO_READY(info)	((info)->cipher_type)
 55
 56#define TLS_RECORD_TYPE_DATA		0x17
 57
 58#define TLS_AAD_SPACE_SIZE		13
 59#define TLS_DEVICE_NAME_MAX		32
 60
 61/*
 62 * This structure defines the routines for Inline TLS driver.
 63 * The following routines are optional and filled with a
 64 * null pointer if not defined.
 65 *
 66 * @name: Its the name of registered Inline tls device
 67 * @dev_list: Inline tls device list
 68 * int (*feature)(struct tls_device *device);
 69 *     Called to return Inline TLS driver capability
 70 *
 71 * int (*hash)(struct tls_device *device, struct sock *sk);
 72 *     This function sets Inline driver for listen and program
 73 *     device specific functioanlity as required
 74 *
 75 * void (*unhash)(struct tls_device *device, struct sock *sk);
 76 *     This function cleans listen state set by Inline TLS driver
 77 */
 78struct tls_device {
 79	char name[TLS_DEVICE_NAME_MAX];
 80	struct list_head dev_list;
 81	int  (*feature)(struct tls_device *device);
 82	int  (*hash)(struct tls_device *device, struct sock *sk);
 83	void (*unhash)(struct tls_device *device, struct sock *sk);
 84};
 85
 86struct tls_sw_context {
 87	struct crypto_aead *aead_send;
 88	struct crypto_aead *aead_recv;
 89	struct crypto_wait async_wait;
 90
 91	/* Receive context */
 92	struct strparser strp;
 93	void (*saved_data_ready)(struct sock *sk);
 94	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
 95				struct poll_table_struct *wait);
 96	struct sk_buff *recv_pkt;
 97	u8 control;
 98	bool decrypted;
 99
100	char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
101	char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];
102
103	/* Sending context */
104	char aad_space[TLS_AAD_SPACE_SIZE];
105
106	unsigned int sg_plaintext_size;
107	int sg_plaintext_num_elem;
108	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
109
110	unsigned int sg_encrypted_size;
111	int sg_encrypted_num_elem;
112	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
113
114	/* AAD | sg_plaintext_data | sg_tag */
115	struct scatterlist sg_aead_in[2];
116	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
117	struct scatterlist sg_aead_out[2];
118};
119
120enum {
121	TLS_PENDING_CLOSED_RECORD
122};
123
124struct cipher_context {
125	u16 prepend_size;
126	u16 tag_size;
127	u16 overhead_size;
128	u16 iv_size;
129	char *iv;
130	u16 rec_seq_size;
131	char *rec_seq;
132};
133
134struct tls_context {
135	union {
136		struct tls_crypto_info crypto_send;
137		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
138	};
139	union {
140		struct tls_crypto_info crypto_recv;
141		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
142	};
143
144	void *priv_ctx;
145
146	u8 conf:3;
147
148	struct cipher_context tx;
149	struct cipher_context rx;
150
151	struct scatterlist *partially_sent_record;
152	u16 partially_sent_offset;
153	unsigned long flags;
154	bool in_tcp_sendpages;
155
156	u16 pending_open_record_frags;
157	int (*push_pending_record)(struct sock *sk, int flags);
158
159	void (*sk_write_space)(struct sock *sk);
160	void (*sk_proto_close)(struct sock *sk, long timeout);
161
162	int  (*setsockopt)(struct sock *sk, int level,
163			   int optname, char __user *optval,
164			   unsigned int optlen);
165	int  (*getsockopt)(struct sock *sk, int level,
166			   int optname, char __user *optval,
167			   int __user *optlen);
168	int  (*hash)(struct sock *sk);
169	void (*unhash)(struct sock *sk);
170};
171
172int wait_on_pending_writer(struct sock *sk, long *timeo);
173int tls_sk_query(struct sock *sk, int optname, char __user *optval,
174		int __user *optlen);
175int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
176		  unsigned int optlen);
177
178
179int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
180int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
181int tls_sw_sendpage(struct sock *sk, struct page *page,
182		    int offset, size_t size, int flags);
183void tls_sw_close(struct sock *sk, long timeout);
184void tls_sw_free_resources(struct sock *sk);
185int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
186		   int nonblock, int flags, int *addr_len);
187unsigned int tls_sw_poll(struct file *file, struct socket *sock,
188			 struct poll_table_struct *wait);
189ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
190			   struct pipe_inode_info *pipe,
191			   size_t len, unsigned int flags);
192
193void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
194void tls_icsk_clean_acked(struct sock *sk);
195
196int tls_push_sg(struct sock *sk, struct tls_context *ctx,
197		struct scatterlist *sg, u16 first_offset,
198		int flags);
199int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
200				   int flags, long *timeo);
201
202static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
203{
204	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
205}
206
207static inline int tls_complete_pending_work(struct sock *sk,
208					    struct tls_context *ctx,
209					    int flags, long *timeo)
210{
211	int rc = 0;
212
213	if (unlikely(sk->sk_write_pending))
214		rc = wait_on_pending_writer(sk, timeo);
215
216	if (!rc && tls_is_pending_closed_record(ctx))
217		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
218
219	return rc;
220}
221
222static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
223{
224	return !!ctx->partially_sent_record;
225}
226
227static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
228{
229	return tls_ctx->pending_open_record_frags;
230}
231
232static inline void tls_err_abort(struct sock *sk, int err)
233{
234	sk->sk_err = err;
235	sk->sk_error_report(sk);
236}
237
238static inline bool tls_bigint_increment(unsigned char *seq, int len)
239{
240	int i;
241
242	for (i = len - 1; i >= 0; i--) {
243		++seq[i];
244		if (seq[i] != 0)
245			break;
246	}
247
248	return (i == -1);
249}
250
251static inline void tls_advance_record_sn(struct sock *sk,
252					 struct cipher_context *ctx)
253{
254	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
255		tls_err_abort(sk, EBADMSG);
256	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
257			     ctx->iv_size);
258}
259
260static inline void tls_fill_prepend(struct tls_context *ctx,
261			     char *buf,
262			     size_t plaintext_len,
263			     unsigned char record_type)
264{
265	size_t pkt_len, iv_size = ctx->tx.iv_size;
266
267	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
268
269	/* we cover nonce explicit here as well, so buf should be of
270	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
271	 */
272	buf[0] = record_type;
273	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
274	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
275	/* we can use IV for nonce explicit according to spec */
276	buf[3] = pkt_len >> 8;
277	buf[4] = pkt_len & 0xFF;
278	memcpy(buf + TLS_NONCE_OFFSET,
279	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
280}
281
282static inline void tls_make_aad(char *buf,
283				size_t size,
284				char *record_sequence,
285				int record_sequence_size,
286				unsigned char record_type)
287{
288	memcpy(buf, record_sequence, record_sequence_size);
289
290	buf[8] = record_type;
291	buf[9] = TLS_1_2_VERSION_MAJOR;
292	buf[10] = TLS_1_2_VERSION_MINOR;
293	buf[11] = size >> 8;
294	buf[12] = size & 0xFF;
295}
296
297static inline struct tls_context *tls_get_ctx(const struct sock *sk)
298{
299	struct inet_connection_sock *icsk = inet_csk(sk);
300
301	return icsk->icsk_ulp_data;
302}
303
304static inline struct tls_sw_context *tls_sw_ctx(
305		const struct tls_context *tls_ctx)
306{
307	return (struct tls_sw_context *)tls_ctx->priv_ctx;
308}
309
310static inline struct tls_offload_context *tls_offload_ctx(
311		const struct tls_context *tls_ctx)
312{
313	return (struct tls_offload_context *)tls_ctx->priv_ctx;
314}
315
316int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
317		      unsigned char *record_type);
318void tls_register_device(struct tls_device *device);
319void tls_unregister_device(struct tls_device *device);
320
321#endif /* _TLS_OFFLOAD_H */