tls.h

  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
 54struct tls_cipher_desc {
 55	unsigned int nonce;
 56	unsigned int iv;
 57	unsigned int key;
 58	unsigned int salt;
 59	unsigned int tag;
 60	unsigned int rec_seq;
 61	unsigned int iv_offset;
 62	unsigned int key_offset;
 63	unsigned int salt_offset;
 64	unsigned int rec_seq_offset;
 65	char *cipher_name;
 66	bool offloadable;
 67	size_t crypto_info;
 68};
 69
 70#define TLS_CIPHER_MIN TLS_CIPHER_AES_GCM_128
 71#define TLS_CIPHER_MAX TLS_CIPHER_ARIA_GCM_256
 72extern const struct tls_cipher_desc tls_cipher_desc[TLS_CIPHER_MAX + 1 - TLS_CIPHER_MIN];
 73
 74static inline const struct tls_cipher_desc *get_cipher_desc(u16 cipher_type)
 75{
 76	if (cipher_type < TLS_CIPHER_MIN || cipher_type > TLS_CIPHER_MAX)
 77		return NULL;
 78
 79	return &tls_cipher_desc[cipher_type - TLS_CIPHER_MIN];
 80}
 81
 82static inline char *crypto_info_iv(struct tls_crypto_info *crypto_info,
 83				   const struct tls_cipher_desc *cipher_desc)
 84{
 85	return (char *)crypto_info + cipher_desc->iv_offset;
 86}
 87
 88static inline char *crypto_info_key(struct tls_crypto_info *crypto_info,
 89				    const struct tls_cipher_desc *cipher_desc)
 90{
 91	return (char *)crypto_info + cipher_desc->key_offset;
 92}
 93
 94static inline char *crypto_info_salt(struct tls_crypto_info *crypto_info,
 95				     const struct tls_cipher_desc *cipher_desc)
 96{
 97	return (char *)crypto_info + cipher_desc->salt_offset;
 98}
 99
100static inline char *crypto_info_rec_seq(struct tls_crypto_info *crypto_info,
101					const struct tls_cipher_desc *cipher_desc)
102{
103	return (char *)crypto_info + cipher_desc->rec_seq_offset;
104}
105
106
107/* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
108 * allocated or mapped for each TLS record. After encryption, the records are
109 * stores in a linked list.
110 */
111struct tls_rec {
112	struct list_head list;
113	int tx_ready;
114	int tx_flags;
115
116	struct sk_msg msg_plaintext;
117	struct sk_msg msg_encrypted;
118
119	/* AAD | msg_plaintext.sg.data | sg_tag */
120	struct scatterlist sg_aead_in[2];
121	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
122	struct scatterlist sg_aead_out[2];
123
124	char content_type;
125	struct scatterlist sg_content_type;
126
127	struct sock *sk;
128
129	char aad_space[TLS_AAD_SPACE_SIZE];
130	u8 iv_data[TLS_MAX_IV_SIZE];
131
132	/* Must be last --ends in a flexible-array member. */
133	struct aead_request aead_req;
134};
135
136int __net_init tls_proc_init(struct net *net);
137void __net_exit tls_proc_fini(struct net *net);
138
139struct tls_context *tls_ctx_create(struct sock *sk);
140void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
141void update_sk_prot(struct sock *sk, struct tls_context *ctx);
142
143int wait_on_pending_writer(struct sock *sk, long *timeo);
144void tls_err_abort(struct sock *sk, int err);
145void tls_strp_abort_strp(struct tls_strparser *strp, int err);
146
147int init_prot_info(struct tls_prot_info *prot,
148		   const struct tls_crypto_info *crypto_info,
149		   const struct tls_cipher_desc *cipher_desc);
150int tls_set_sw_offload(struct sock *sk, int tx,
151		       struct tls_crypto_info *new_crypto_info);
152void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
153void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
154void tls_sw_strparser_done(struct tls_context *tls_ctx);
155int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
156void tls_sw_splice_eof(struct socket *sock);
157void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
158void tls_sw_release_resources_tx(struct sock *sk);
159void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
160void tls_sw_free_resources_rx(struct sock *sk);
161void tls_sw_release_resources_rx(struct sock *sk);
162void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
163int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
164		   int flags, int *addr_len);
165bool tls_sw_sock_is_readable(struct sock *sk);
166ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
167			   struct pipe_inode_info *pipe,
168			   size_t len, unsigned int flags);
169int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
170		     sk_read_actor_t read_actor);
171
172int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
173void tls_device_splice_eof(struct socket *sock);
174int tls_tx_records(struct sock *sk, int flags);
175
176void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
177void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
178
179int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
180		     unsigned char *record_type);
181int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
182
183int tls_sw_fallback_init(struct sock *sk,
184			 struct tls_offload_context_tx *offload_ctx,
185			 struct tls_crypto_info *crypto_info);
186
187int tls_strp_dev_init(void);
188void tls_strp_dev_exit(void);
189
190void tls_strp_done(struct tls_strparser *strp);
191void tls_strp_stop(struct tls_strparser *strp);
192int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
193void tls_strp_data_ready(struct tls_strparser *strp);
194
195void tls_strp_check_rcv(struct tls_strparser *strp);
196void tls_strp_msg_done(struct tls_strparser *strp);
197
198int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
199void tls_rx_msg_ready(struct tls_strparser *strp);
200
201bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
202int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
203struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
204int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
205
206static inline struct tls_msg *tls_msg(struct sk_buff *skb)
207{
208	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
209
210	return &scb->tls;
211}
212
213static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
214{
215	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
216	return ctx->strp.anchor;
217}
218
219static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
220{
221	return READ_ONCE(ctx->strp.msg_ready);
222}
223
224static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
225{
226	return ctx->strp.mixed_decrypted;
227}
228
229#ifdef CONFIG_TLS_DEVICE
230int tls_device_init(void);
231void tls_device_cleanup(void);
232int tls_set_device_offload(struct sock *sk);
233void tls_device_free_resources_tx(struct sock *sk);
234int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
235void tls_device_offload_cleanup_rx(struct sock *sk);
236void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
237int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
238#else
239static inline int tls_device_init(void) { return 0; }
240static inline void tls_device_cleanup(void) {}
241
242static inline int
243tls_set_device_offload(struct sock *sk)
244{
245	return -EOPNOTSUPP;
246}
247
248static inline void tls_device_free_resources_tx(struct sock *sk) {}
249
250static inline int
251tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
252{
253	return -EOPNOTSUPP;
254}
255
256static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
257static inline void
258tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
259
260static inline int
261tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
262{
263	return 0;
264}
265#endif
266
267int tls_push_sg(struct sock *sk, struct tls_context *ctx,
268		struct scatterlist *sg, u16 first_offset,
269		int flags);
270int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
271			    int flags);
272void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
273
274static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
275{
276	return !!ctx->partially_sent_record;
277}
278
279static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
280{
281	return tls_ctx->pending_open_record_frags;
282}
283
284static inline bool tls_bigint_increment(unsigned char *seq, int len)
285{
286	int i;
287
288	for (i = len - 1; i >= 0; i--) {
289		++seq[i];
290		if (seq[i] != 0)
291			break;
292	}
293
294	return (i == -1);
295}
296
297static inline void tls_bigint_subtract(unsigned char *seq, int  n)
298{
299	u64 rcd_sn;
300	__be64 *p;
301
302	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
303
304	p = (__be64 *)seq;
305	rcd_sn = be64_to_cpu(*p);
306	*p = cpu_to_be64(rcd_sn - n);
307}
308
309static inline void
310tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
311		      struct cipher_context *ctx)
312{
313	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
314		tls_err_abort(sk, -EBADMSG);
315
316	if (prot->version != TLS_1_3_VERSION &&
317	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
318		tls_bigint_increment(ctx->iv + prot->salt_size,
319				     prot->iv_size);
320}
321
322static inline void
323tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
324{
325	int i;
326
327	if (prot->version == TLS_1_3_VERSION ||
328	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
329		for (i = 0; i < 8; i++)
330			iv[i + 4] ^= seq[i];
331	}
332}
333
334static inline void
335tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
336		 unsigned char record_type)
337{
338	struct tls_prot_info *prot = &ctx->prot_info;
339	size_t pkt_len, iv_size = prot->iv_size;
340
341	pkt_len = plaintext_len + prot->tag_size;
342	if (prot->version != TLS_1_3_VERSION &&
343	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
344		pkt_len += iv_size;
345
346		memcpy(buf + TLS_NONCE_OFFSET,
347		       ctx->tx.iv + prot->salt_size, iv_size);
348	}
349
350	/* we cover nonce explicit here as well, so buf should be of
351	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
352	 */
353	buf[0] = prot->version == TLS_1_3_VERSION ?
354		   TLS_RECORD_TYPE_DATA : record_type;
355	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
356	buf[1] = TLS_1_2_VERSION_MINOR;
357	buf[2] = TLS_1_2_VERSION_MAJOR;
358	/* we can use IV for nonce explicit according to spec */
359	buf[3] = pkt_len >> 8;
360	buf[4] = pkt_len & 0xFF;
361}
362
363static inline
364void tls_make_aad(char *buf, size_t size, char *record_sequence,
365		  unsigned char record_type, struct tls_prot_info *prot)
366{
367	if (prot->version != TLS_1_3_VERSION) {
368		memcpy(buf, record_sequence, prot->rec_seq_size);
369		buf += 8;
370	} else {
371		size += prot->tag_size;
372	}
373
374	buf[0] = prot->version == TLS_1_3_VERSION ?
375		  TLS_RECORD_TYPE_DATA : record_type;
376	buf[1] = TLS_1_2_VERSION_MAJOR;
377	buf[2] = TLS_1_2_VERSION_MINOR;
378	buf[3] = size >> 8;
379	buf[4] = size & 0xFF;
380}
381
382#endif