1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * net/tipc/crypto.c: TIPC crypto for key handling & packet en/decryption
4 *
5 * Copyright (c) 2019, Ericsson AB
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include <crypto/aead.h>
38 #include <crypto/aes.h>
39 #include <crypto/rng.h>
40 #include "crypto.h"
41 #include "msg.h"
42 #include "bcast.h"
43
44 #define TIPC_TX_GRACE_PERIOD msecs_to_jiffies(5000) /* 5s */
45 #define TIPC_TX_LASTING_TIME msecs_to_jiffies(10000) /* 10s */
46 #define TIPC_RX_ACTIVE_LIM msecs_to_jiffies(3000) /* 3s */
47 #define TIPC_RX_PASSIVE_LIM msecs_to_jiffies(15000) /* 15s */
48
49 #define TIPC_MAX_TFMS_DEF 10
50 #define TIPC_MAX_TFMS_LIM 1000
51
52 #define TIPC_REKEYING_INTV_DEF (60 * 24) /* default: 1 day */
53
54 /*
55 * TIPC Key ids
56 */
57 enum {
58 KEY_MASTER = 0,
59 KEY_MIN = KEY_MASTER,
60 KEY_1 = 1,
61 KEY_2,
62 KEY_3,
63 KEY_MAX = KEY_3,
64 };
65
66 /*
67 * TIPC Crypto statistics
68 */
69 enum {
70 STAT_OK,
71 STAT_NOK,
72 STAT_ASYNC,
73 STAT_ASYNC_OK,
74 STAT_ASYNC_NOK,
75 STAT_BADKEYS, /* tx only */
76 STAT_BADMSGS = STAT_BADKEYS, /* rx only */
77 STAT_NOKEYS,
78 STAT_SWITCHES,
79
80 MAX_STATS,
81 };
82
83 /* TIPC crypto statistics' header */
84 static const char *hstats[MAX_STATS] = {"ok", "nok", "async", "async_ok",
85 "async_nok", "badmsgs", "nokeys",
86 "switches"};
87
88 /* Max TFMs number per key */
89 int sysctl_tipc_max_tfms __read_mostly = TIPC_MAX_TFMS_DEF;
90 /* Key exchange switch, default: on */
91 int sysctl_tipc_key_exchange_enabled __read_mostly = 1;
92
93 /*
94 * struct tipc_key - TIPC keys' status indicator
95 *
96 * 7 6 5 4 3 2 1 0
97 * +-----+-----+-----+-----+-----+-----+-----+-----+
98 * key: | (reserved)|passive idx| active idx|pending idx|
99 * +-----+-----+-----+-----+-----+-----+-----+-----+
100 */
101 struct tipc_key {
102 #define KEY_BITS (2)
103 #define KEY_MASK ((1 << KEY_BITS) - 1)
104 union {
105 struct {
106 #if defined(__LITTLE_ENDIAN_BITFIELD)
107 u8 pending:2,
108 active:2,
109 passive:2, /* rx only */
110 reserved:2;
111 #elif defined(__BIG_ENDIAN_BITFIELD)
112 u8 reserved:2,
113 passive:2, /* rx only */
114 active:2,
115 pending:2;
116 #else
117 #error "Please fix <asm/byteorder.h>"
118 #endif
119 } __packed;
120 u8 keys;
121 };
122 };
123
124 /**
125 * struct tipc_tfm - TIPC TFM structure to form a list of TFMs
126 * @tfm: cipher handle/key
127 * @list: linked list of TFMs
128 */
129 struct tipc_tfm {
130 struct crypto_aead *tfm;
131 struct list_head list;
132 };
133
134 /**
135 * struct tipc_aead - TIPC AEAD key structure
136 * @tfm_entry: per-cpu pointer to one entry in TFM list
137 * @crypto: TIPC crypto owns this key
138 * @cloned: reference to the source key in case cloning
139 * @users: the number of the key users (TX/RX)
140 * @salt: the key's SALT value
141 * @authsize: authentication tag size (max = 16)
142 * @mode: crypto mode is applied to the key
143 * @hint: a hint for user key
144 * @rcu: struct rcu_head
145 * @key: the aead key
146 * @gen: the key's generation
147 * @seqno: the key seqno (cluster scope)
148 * @refcnt: the key reference counter
149 */
150 struct tipc_aead {
151 #define TIPC_AEAD_HINT_LEN (5)
152 struct tipc_tfm * __percpu *tfm_entry;
153 struct tipc_crypto *crypto;
154 struct tipc_aead *cloned;
155 atomic_t users;
156 u32 salt;
157 u8 authsize;
158 u8 mode;
159 char hint[2 * TIPC_AEAD_HINT_LEN + 1];
160 struct rcu_head rcu;
161 struct tipc_aead_key *key;
162 u16 gen;
163
164 atomic64_t seqno ____cacheline_aligned;
165 refcount_t refcnt ____cacheline_aligned;
166
167 } ____cacheline_aligned;
168
169 /**
170 * struct tipc_crypto_stats - TIPC Crypto statistics
171 * @stat: array of crypto statistics
172 */
173 struct tipc_crypto_stats {
174 unsigned int stat[MAX_STATS];
175 };
176
177 /**
178 * struct tipc_crypto - TIPC TX/RX crypto structure
179 * @net: struct net
180 * @node: TIPC node (RX)
181 * @aead: array of pointers to AEAD keys for encryption/decryption
182 * @peer_rx_active: replicated peer RX active key index
183 * @key_gen: TX/RX key generation
184 * @key: the key states
185 * @skey_mode: session key's mode
186 * @skey: received session key
187 * @wq: common workqueue on TX crypto
188 * @work: delayed work sched for TX/RX
189 * @key_distr: key distributing state
190 * @rekeying_intv: rekeying interval (in minutes)
191 * @stats: the crypto statistics
192 * @name: the crypto name
193 * @sndnxt: the per-peer sndnxt (TX)
194 * @timer1: general timer 1 (jiffies)
195 * @timer2: general timer 2 (jiffies)
196 * @working: the crypto is working or not
197 * @key_master: flag indicates if master key exists
198 * @legacy_user: flag indicates if a peer joins w/o master key (for bwd comp.)
199 * @nokey: no key indication
200 * @flags: combined flags field
201 * @lock: tipc_key lock
202 */
203 struct tipc_crypto {
204 struct net *net;
205 struct tipc_node *node;
206 struct tipc_aead __rcu *aead[KEY_MAX + 1];
207 atomic_t peer_rx_active;
208 u16 key_gen;
209 struct tipc_key key;
210 u8 skey_mode;
211 struct tipc_aead_key *skey;
212 struct workqueue_struct *wq;
213 struct delayed_work work;
214 #define KEY_DISTR_SCHED 1
215 #define KEY_DISTR_COMPL 2
216 atomic_t key_distr;
217 u32 rekeying_intv;
218
219 struct tipc_crypto_stats __percpu *stats;
220 char name[48];
221
222 atomic64_t sndnxt ____cacheline_aligned;
223 unsigned long timer1;
224 unsigned long timer2;
225 union {
226 struct {
227 u8 working:1;
228 u8 key_master:1;
229 u8 legacy_user:1;
230 u8 nokey: 1;
231 };
232 u8 flags;
233 };
234 spinlock_t lock; /* crypto lock */
235
236 } ____cacheline_aligned;
237
238 /* struct tipc_crypto_tx_ctx - TX context for callbacks */
239 struct tipc_crypto_tx_ctx {
240 struct tipc_aead *aead;
241 struct tipc_bearer *bearer;
242 struct tipc_media_addr dst;
243 };
244
245 /* struct tipc_crypto_rx_ctx - RX context for callbacks */
246 struct tipc_crypto_rx_ctx {
247 struct tipc_aead *aead;
248 struct tipc_bearer *bearer;
249 };
250
251 static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead);
252 static inline void tipc_aead_put(struct tipc_aead *aead);
253 static void tipc_aead_free(struct rcu_head *rp);
254 static int tipc_aead_users(struct tipc_aead __rcu *aead);
255 static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim);
256 static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim);
257 static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val);
258 static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead);
259 static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
260 u8 mode);
261 static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src);
262 static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
263 unsigned int crypto_ctx_size,
264 u8 **iv, struct aead_request **req,
265 struct scatterlist **sg, int nsg);
266 static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
267 struct tipc_bearer *b,
268 struct tipc_media_addr *dst,
269 struct tipc_node *__dnode);
270 static void tipc_aead_encrypt_done(void *data, int err);
271 static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
272 struct sk_buff *skb, struct tipc_bearer *b);
273 static void tipc_aead_decrypt_done(void *data, int err);
274 static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr);
275 static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
276 u8 tx_key, struct sk_buff *skb,
277 struct tipc_crypto *__rx);
278 static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
279 u8 new_passive,
280 u8 new_active,
281 u8 new_pending);
282 static int tipc_crypto_key_attach(struct tipc_crypto *c,
283 struct tipc_aead *aead, u8 pos,
284 bool master_key);
285 static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending);
286 static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
287 struct tipc_crypto *rx,
288 struct sk_buff *skb,
289 u8 tx_key);
290 static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb);
291 static int tipc_crypto_key_revoke(struct net *net, u8 tx_key);
292 static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
293 struct tipc_bearer *b,
294 struct tipc_media_addr *dst,
295 struct tipc_node *__dnode, u8 type);
296 static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
297 struct tipc_bearer *b,
298 struct sk_buff **skb, int err);
299 static void tipc_crypto_do_cmd(struct net *net, int cmd);
300 static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf);
301 static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
302 char *buf);
303 static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
304 u16 gen, u8 mode, u32 dnode);
305 static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr);
306 static void tipc_crypto_work_tx(struct work_struct *work);
307 static void tipc_crypto_work_rx(struct work_struct *work);
308 static int tipc_aead_key_generate(struct tipc_aead_key *skey);
309
310 #define is_tx(crypto) (!(crypto)->node)
311 #define is_rx(crypto) (!is_tx(crypto))
312
313 #define key_next(cur) ((cur) % KEY_MAX + 1)
314
315 #define tipc_aead_rcu_ptr(rcu_ptr, lock) \
316 rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock))
317
318 #define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) \
319 do { \
320 struct tipc_aead *__tmp = rcu_dereference_protected((rcu_ptr), \
321 lockdep_is_held(lock)); \
322 rcu_assign_pointer((rcu_ptr), (ptr)); \
323 tipc_aead_put(__tmp); \
324 } while (0)
325
326 #define tipc_crypto_key_detach(rcu_ptr, lock) \
327 tipc_aead_rcu_replace((rcu_ptr), NULL, lock)
328
329 /**
330 * tipc_aead_key_validate - Validate a AEAD user key
331 * @ukey: pointer to user key data
332 * @info: netlink info pointer
333 */
tipc_aead_key_validate(struct tipc_aead_key * ukey,struct genl_info * info)334 int tipc_aead_key_validate(struct tipc_aead_key *ukey, struct genl_info *info)
335 {
336 int keylen;
337
338 /* Check if algorithm exists */
339 if (unlikely(!crypto_has_alg(ukey->alg_name, 0, 0))) {
340 GENL_SET_ERR_MSG(info, "unable to load the algorithm (module existed?)");
341 return -ENODEV;
342 }
343
344 /* Currently, we only support the "gcm(aes)" cipher algorithm */
345 if (strcmp(ukey->alg_name, "gcm(aes)")) {
346 GENL_SET_ERR_MSG(info, "not supported yet the algorithm");
347 return -ENOTSUPP;
348 }
349
350 /* Check if key size is correct */
351 keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
352 if (unlikely(keylen != TIPC_AES_GCM_KEY_SIZE_128 &&
353 keylen != TIPC_AES_GCM_KEY_SIZE_192 &&
354 keylen != TIPC_AES_GCM_KEY_SIZE_256)) {
355 GENL_SET_ERR_MSG(info, "incorrect key length (20, 28 or 36 octets?)");
356 return -EKEYREJECTED;
357 }
358
359 return 0;
360 }
361
362 /**
363 * tipc_aead_key_generate - Generate new session key
364 * @skey: input/output key with new content
365 *
366 * Return: 0 in case of success, otherwise < 0
367 */
tipc_aead_key_generate(struct tipc_aead_key * skey)368 static int tipc_aead_key_generate(struct tipc_aead_key *skey)
369 {
370 int rc = 0;
371
372 /* Fill the key's content with a random value via RNG cipher */
373 rc = crypto_get_default_rng();
374 if (likely(!rc)) {
375 rc = crypto_rng_get_bytes(crypto_default_rng, skey->key,
376 skey->keylen);
377 crypto_put_default_rng();
378 }
379
380 return rc;
381 }
382
tipc_aead_get(struct tipc_aead __rcu * aead)383 static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead)
384 {
385 struct tipc_aead *tmp;
386
387 rcu_read_lock();
388 tmp = rcu_dereference(aead);
389 if (unlikely(!tmp || !refcount_inc_not_zero(&tmp->refcnt)))
390 tmp = NULL;
391 rcu_read_unlock();
392
393 return tmp;
394 }
395
tipc_aead_put(struct tipc_aead * aead)396 static inline void tipc_aead_put(struct tipc_aead *aead)
397 {
398 if (aead && refcount_dec_and_test(&aead->refcnt))
399 call_rcu(&aead->rcu, tipc_aead_free);
400 }
401
402 /**
403 * tipc_aead_free - Release AEAD key incl. all the TFMs in the list
404 * @rp: rcu head pointer
405 */
tipc_aead_free(struct rcu_head * rp)406 static void tipc_aead_free(struct rcu_head *rp)
407 {
408 struct tipc_aead *aead = container_of(rp, struct tipc_aead, rcu);
409 struct tipc_tfm *tfm_entry, *head, *tmp;
410
411 if (aead->cloned) {
412 tipc_aead_put(aead->cloned);
413 } else {
414 head = *get_cpu_ptr(aead->tfm_entry);
415 put_cpu_ptr(aead->tfm_entry);
416 list_for_each_entry_safe(tfm_entry, tmp, &head->list, list) {
417 crypto_free_aead(tfm_entry->tfm);
418 list_del(&tfm_entry->list);
419 kfree(tfm_entry);
420 }
421 /* Free the head */
422 crypto_free_aead(head->tfm);
423 list_del(&head->list);
424 kfree(head);
425 }
426 free_percpu(aead->tfm_entry);
427 kfree_sensitive(aead->key);
428 kfree(aead);
429 }
430
tipc_aead_users(struct tipc_aead __rcu * aead)431 static int tipc_aead_users(struct tipc_aead __rcu *aead)
432 {
433 struct tipc_aead *tmp;
434 int users = 0;
435
436 rcu_read_lock();
437 tmp = rcu_dereference(aead);
438 if (tmp)
439 users = atomic_read(&tmp->users);
440 rcu_read_unlock();
441
442 return users;
443 }
444
tipc_aead_users_inc(struct tipc_aead __rcu * aead,int lim)445 static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim)
446 {
447 struct tipc_aead *tmp;
448
449 rcu_read_lock();
450 tmp = rcu_dereference(aead);
451 if (tmp)
452 atomic_add_unless(&tmp->users, 1, lim);
453 rcu_read_unlock();
454 }
455
tipc_aead_users_dec(struct tipc_aead __rcu * aead,int lim)456 static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim)
457 {
458 struct tipc_aead *tmp;
459
460 rcu_read_lock();
461 tmp = rcu_dereference(aead);
462 if (tmp)
463 atomic_add_unless(&rcu_dereference(aead)->users, -1, lim);
464 rcu_read_unlock();
465 }
466
tipc_aead_users_set(struct tipc_aead __rcu * aead,int val)467 static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val)
468 {
469 struct tipc_aead *tmp;
470 int cur;
471
472 rcu_read_lock();
473 tmp = rcu_dereference(aead);
474 if (tmp) {
475 do {
476 cur = atomic_read(&tmp->users);
477 if (cur == val)
478 break;
479 } while (atomic_cmpxchg(&tmp->users, cur, val) != cur);
480 }
481 rcu_read_unlock();
482 }
483
484 /**
485 * tipc_aead_tfm_next - Move TFM entry to the next one in list and return it
486 * @aead: the AEAD key pointer
487 */
tipc_aead_tfm_next(struct tipc_aead * aead)488 static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead)
489 {
490 struct tipc_tfm **tfm_entry;
491 struct crypto_aead *tfm;
492
493 tfm_entry = get_cpu_ptr(aead->tfm_entry);
494 *tfm_entry = list_next_entry(*tfm_entry, list);
495 tfm = (*tfm_entry)->tfm;
496 put_cpu_ptr(tfm_entry);
497
498 return tfm;
499 }
500
501 /**
502 * tipc_aead_init - Initiate TIPC AEAD
503 * @aead: returned new TIPC AEAD key handle pointer
504 * @ukey: pointer to user key data
505 * @mode: the key mode
506 *
507 * Allocate a (list of) new cipher transformation (TFM) with the specific user
508 * key data if valid. The number of the allocated TFMs can be set via the sysfs
509 * "net/tipc/max_tfms" first.
510 * Also, all the other AEAD data are also initialized.
511 *
512 * Return: 0 if the initiation is successful, otherwise: < 0
513 */
tipc_aead_init(struct tipc_aead ** aead,struct tipc_aead_key * ukey,u8 mode)514 static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
515 u8 mode)
516 {
517 struct tipc_tfm *tfm_entry, *head;
518 struct crypto_aead *tfm;
519 struct tipc_aead *tmp;
520 int keylen, err, cpu;
521 int tfm_cnt = 0;
522
523 if (unlikely(*aead))
524 return -EEXIST;
525
526 /* Allocate a new AEAD */
527 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
528 if (unlikely(!tmp))
529 return -ENOMEM;
530
531 /* The key consists of two parts: [AES-KEY][SALT] */
532 keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
533
534 /* Allocate per-cpu TFM entry pointer */
535 tmp->tfm_entry = alloc_percpu(struct tipc_tfm *);
536 if (!tmp->tfm_entry) {
537 kfree_sensitive(tmp);
538 return -ENOMEM;
539 }
540
541 /* Make a list of TFMs with the user key data */
542 do {
543 tfm = crypto_alloc_aead(ukey->alg_name, 0, 0);
544 if (IS_ERR(tfm)) {
545 err = PTR_ERR(tfm);
546 break;
547 }
548
549 if (unlikely(!tfm_cnt &&
550 crypto_aead_ivsize(tfm) != TIPC_AES_GCM_IV_SIZE)) {
551 crypto_free_aead(tfm);
552 err = -ENOTSUPP;
553 break;
554 }
555
556 err = crypto_aead_setauthsize(tfm, TIPC_AES_GCM_TAG_SIZE);
557 err |= crypto_aead_setkey(tfm, ukey->key, keylen);
558 if (unlikely(err)) {
559 crypto_free_aead(tfm);
560 break;
561 }
562
563 tfm_entry = kmalloc(sizeof(*tfm_entry), GFP_KERNEL);
564 if (unlikely(!tfm_entry)) {
565 crypto_free_aead(tfm);
566 err = -ENOMEM;
567 break;
568 }
569 INIT_LIST_HEAD(&tfm_entry->list);
570 tfm_entry->tfm = tfm;
571
572 /* First entry? */
573 if (!tfm_cnt) {
574 head = tfm_entry;
575 for_each_possible_cpu(cpu) {
576 *per_cpu_ptr(tmp->tfm_entry, cpu) = head;
577 }
578 } else {
579 list_add_tail(&tfm_entry->list, &head->list);
580 }
581
582 } while (++tfm_cnt < sysctl_tipc_max_tfms);
583
584 /* Not any TFM is allocated? */
585 if (!tfm_cnt) {
586 free_percpu(tmp->tfm_entry);
587 kfree_sensitive(tmp);
588 return err;
589 }
590
591 /* Form a hex string of some last bytes as the key's hint */
592 bin2hex(tmp->hint, ukey->key + keylen - TIPC_AEAD_HINT_LEN,
593 TIPC_AEAD_HINT_LEN);
594
595 /* Initialize the other data */
596 tmp->mode = mode;
597 tmp->cloned = NULL;
598 tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
599 tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL);
600 if (!tmp->key) {
601 tipc_aead_free(&tmp->rcu);
602 return -ENOMEM;
603 }
604 memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
605 atomic_set(&tmp->users, 0);
606 atomic64_set(&tmp->seqno, 0);
607 refcount_set(&tmp->refcnt, 1);
608
609 *aead = tmp;
610 return 0;
611 }
612
613 /**
614 * tipc_aead_clone - Clone a TIPC AEAD key
615 * @dst: dest key for the cloning
616 * @src: source key to clone from
617 *
618 * Make a "copy" of the source AEAD key data to the dest, the TFMs list is
619 * common for the keys.
620 * A reference to the source is hold in the "cloned" pointer for the later
621 * freeing purposes.
622 *
623 * Note: this must be done in cluster-key mode only!
624 * Return: 0 in case of success, otherwise < 0
625 */
tipc_aead_clone(struct tipc_aead ** dst,struct tipc_aead * src)626 static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src)
627 {
628 struct tipc_aead *aead;
629 int cpu;
630
631 if (!src)
632 return -ENOKEY;
633
634 if (src->mode != CLUSTER_KEY)
635 return -EINVAL;
636
637 if (unlikely(*dst))
638 return -EEXIST;
639
640 aead = kzalloc(sizeof(*aead), GFP_ATOMIC);
641 if (unlikely(!aead))
642 return -ENOMEM;
643
644 aead->tfm_entry = alloc_percpu_gfp(struct tipc_tfm *, GFP_ATOMIC);
645 if (unlikely(!aead->tfm_entry)) {
646 kfree_sensitive(aead);
647 return -ENOMEM;
648 }
649
650 for_each_possible_cpu(cpu) {
651 *per_cpu_ptr(aead->tfm_entry, cpu) =
652 *per_cpu_ptr(src->tfm_entry, cpu);
653 }
654
655 memcpy(aead->hint, src->hint, sizeof(src->hint));
656 aead->mode = src->mode;
657 aead->salt = src->salt;
658 aead->authsize = src->authsize;
659 atomic_set(&aead->users, 0);
660 atomic64_set(&aead->seqno, 0);
661 refcount_set(&aead->refcnt, 1);
662
663 WARN_ON(!refcount_inc_not_zero(&src->refcnt));
664 aead->cloned = src;
665
666 *dst = aead;
667 return 0;
668 }
669
670 /**
671 * tipc_aead_mem_alloc - Allocate memory for AEAD request operations
672 * @tfm: cipher handle to be registered with the request
673 * @crypto_ctx_size: size of crypto context for callback
674 * @iv: returned pointer to IV data
675 * @req: returned pointer to AEAD request data
676 * @sg: returned pointer to SG lists
677 * @nsg: number of SG lists to be allocated
678 *
679 * Allocate memory to store the crypto context data, AEAD request, IV and SG
680 * lists, the memory layout is as follows:
681 * crypto_ctx || iv || aead_req || sg[]
682 *
683 * Return: the pointer to the memory areas in case of success, otherwise NULL
684 */
tipc_aead_mem_alloc(struct crypto_aead * tfm,unsigned int crypto_ctx_size,u8 ** iv,struct aead_request ** req,struct scatterlist ** sg,int nsg)685 static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
686 unsigned int crypto_ctx_size,
687 u8 **iv, struct aead_request **req,
688 struct scatterlist **sg, int nsg)
689 {
690 unsigned int iv_size, req_size;
691 unsigned int len;
692 u8 *mem;
693
694 iv_size = crypto_aead_ivsize(tfm);
695 req_size = sizeof(**req) + crypto_aead_reqsize(tfm);
696
697 len = crypto_ctx_size;
698 len += iv_size;
699 len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1);
700 len = ALIGN(len, crypto_tfm_ctx_alignment());
701 len += req_size;
702 len = ALIGN(len, __alignof__(struct scatterlist));
703 len += nsg * sizeof(**sg);
704
705 mem = kmalloc(len, GFP_ATOMIC);
706 if (!mem)
707 return NULL;
708
709 *iv = (u8 *)PTR_ALIGN(mem + crypto_ctx_size,
710 crypto_aead_alignmask(tfm) + 1);
711 *req = (struct aead_request *)PTR_ALIGN(*iv + iv_size,
712 crypto_tfm_ctx_alignment());
713 *sg = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
714 __alignof__(struct scatterlist));
715
716 return (void *)mem;
717 }
718
719 /**
720 * tipc_aead_encrypt - Encrypt a message
721 * @aead: TIPC AEAD key for the message encryption
722 * @skb: the input/output skb
723 * @b: TIPC bearer where the message will be delivered after the encryption
724 * @dst: the destination media address
725 * @__dnode: TIPC dest node if "known"
726 *
727 * Return:
728 * * 0 : if the encryption has completed
729 * * -EINPROGRESS/-EBUSY : if a callback will be performed
730 * * < 0 : the encryption has failed
731 */
tipc_aead_encrypt(struct tipc_aead * aead,struct sk_buff * skb,struct tipc_bearer * b,struct tipc_media_addr * dst,struct tipc_node * __dnode)732 static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
733 struct tipc_bearer *b,
734 struct tipc_media_addr *dst,
735 struct tipc_node *__dnode)
736 {
737 struct crypto_aead *tfm = tipc_aead_tfm_next(aead);
738 struct tipc_crypto_tx_ctx *tx_ctx;
739 struct aead_request *req;
740 struct sk_buff *trailer;
741 struct scatterlist *sg;
742 struct tipc_ehdr *ehdr;
743 int ehsz, len, tailen, nsg, rc;
744 void *ctx;
745 u32 salt;
746 u8 *iv;
747
748 /* Make sure message len at least 4-byte aligned */
749 len = ALIGN(skb->len, 4);
750 tailen = len - skb->len + aead->authsize;
751
752 /* Expand skb tail for authentication tag:
753 * As for simplicity, we'd have made sure skb having enough tailroom
754 * for authentication tag @skb allocation. Even when skb is nonlinear
755 * but there is no frag_list, it should be still fine!
756 * Otherwise, we must cow it to be a writable buffer with the tailroom.
757 */
758 SKB_LINEAR_ASSERT(skb);
759 if (tailen > skb_tailroom(skb)) {
760 pr_debug("TX(): skb tailroom is not enough: %d, requires: %d\n",
761 skb_tailroom(skb), tailen);
762 }
763
764 nsg = skb_cow_data(skb, tailen, &trailer);
765 if (unlikely(nsg < 0)) {
766 pr_err("TX: skb_cow_data() returned %d\n", nsg);
767 return nsg;
768 }
769
770 pskb_put(skb, trailer, tailen);
771
772 /* Allocate memory for the AEAD operation */
773 ctx = tipc_aead_mem_alloc(tfm, sizeof(*tx_ctx), &iv, &req, &sg, nsg);
774 if (unlikely(!ctx))
775 return -ENOMEM;
776 TIPC_SKB_CB(skb)->crypto_ctx = ctx;
777
778 /* Map skb to the sg lists */
779 sg_init_table(sg, nsg);
780 rc = skb_to_sgvec(skb, sg, 0, skb->len);
781 if (unlikely(rc < 0)) {
782 pr_err("TX: skb_to_sgvec() returned %d, nsg %d!\n", rc, nsg);
783 goto exit;
784 }
785
786 /* Prepare IV: [SALT (4 octets)][SEQNO (8 octets)]
787 * In case we're in cluster-key mode, SALT is varied by xor-ing with
788 * the source address (or w0 of id), otherwise with the dest address
789 * if dest is known.
790 */
791 ehdr = (struct tipc_ehdr *)skb->data;
792 salt = aead->salt;
793 if (aead->mode == CLUSTER_KEY)
794 salt ^= __be32_to_cpu(ehdr->addr);
795 else if (__dnode)
796 salt ^= tipc_node_get_addr(__dnode);
797 memcpy(iv, &salt, 4);
798 memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
799
800 /* Prepare request */
801 ehsz = tipc_ehdr_size(ehdr);
802 aead_request_set_tfm(req, tfm);
803 aead_request_set_ad(req, ehsz);
804 aead_request_set_crypt(req, sg, sg, len - ehsz, iv);
805
806 /* Set callback function & data */
807 aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
808 tipc_aead_encrypt_done, skb);
809 tx_ctx = (struct tipc_crypto_tx_ctx *)ctx;
810 tx_ctx->aead = aead;
811 tx_ctx->bearer = b;
812 memcpy(&tx_ctx->dst, dst, sizeof(*dst));
813
814 /* Hold bearer */
815 if (unlikely(!tipc_bearer_hold(b))) {
816 rc = -ENODEV;
817 goto exit;
818 }
819
820 /* Now, do encrypt */
821 rc = crypto_aead_encrypt(req);
822 if (rc == -EINPROGRESS || rc == -EBUSY)
823 return rc;
824
825 tipc_bearer_put(b);
826
827 exit:
828 kfree(ctx);
829 TIPC_SKB_CB(skb)->crypto_ctx = NULL;
830 return rc;
831 }
832
tipc_aead_encrypt_done(void * data,int err)833 static void tipc_aead_encrypt_done(void *data, int err)
834 {
835 struct sk_buff *skb = data;
836 struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
837 struct tipc_bearer *b = tx_ctx->bearer;
838 struct tipc_aead *aead = tx_ctx->aead;
839 struct tipc_crypto *tx = aead->crypto;
840 struct net *net = tx->net;
841
842 switch (err) {
843 case 0:
844 this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]);
845 rcu_read_lock();
846 if (likely(test_bit(0, &b->up)))
847 b->media->send_msg(net, skb, b, &tx_ctx->dst);
848 else
849 kfree_skb(skb);
850 rcu_read_unlock();
851 break;
852 case -EINPROGRESS:
853 return;
854 default:
855 this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]);
856 kfree_skb(skb);
857 break;
858 }
859
860 kfree(tx_ctx);
861 tipc_bearer_put(b);
862 tipc_aead_put(aead);
863 }
864
865 /**
866 * tipc_aead_decrypt - Decrypt an encrypted message
867 * @net: struct net
868 * @aead: TIPC AEAD for the message decryption
869 * @skb: the input/output skb
870 * @b: TIPC bearer where the message has been received
871 *
872 * Return:
873 * * 0 : if the decryption has completed
874 * * -EINPROGRESS/-EBUSY : if a callback will be performed
875 * * < 0 : the decryption has failed
876 */
tipc_aead_decrypt(struct net * net,struct tipc_aead * aead,struct sk_buff * skb,struct tipc_bearer * b)877 static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
878 struct sk_buff *skb, struct tipc_bearer *b)
879 {
880 struct tipc_crypto_rx_ctx *rx_ctx;
881 struct aead_request *req;
882 struct crypto_aead *tfm;
883 struct sk_buff *unused;
884 struct scatterlist *sg;
885 struct tipc_ehdr *ehdr;
886 int ehsz, nsg, rc;
887 void *ctx;
888 u32 salt;
889 u8 *iv;
890
891 if (unlikely(!aead))
892 return -ENOKEY;
893
894 nsg = skb_cow_data(skb, 0, &unused);
895 if (unlikely(nsg < 0)) {
896 pr_err("RX: skb_cow_data() returned %d\n", nsg);
897 return nsg;
898 }
899
900 /* Allocate memory for the AEAD operation */
901 tfm = tipc_aead_tfm_next(aead);
902 ctx = tipc_aead_mem_alloc(tfm, sizeof(*rx_ctx), &iv, &req, &sg, nsg);
903 if (unlikely(!ctx))
904 return -ENOMEM;
905 TIPC_SKB_CB(skb)->crypto_ctx = ctx;
906
907 /* Map skb to the sg lists */
908 sg_init_table(sg, nsg);
909 rc = skb_to_sgvec(skb, sg, 0, skb->len);
910 if (unlikely(rc < 0)) {
911 pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg);
912 goto exit;
913 }
914
915 /* Reconstruct IV: */
916 ehdr = (struct tipc_ehdr *)skb->data;
917 salt = aead->salt;
918 if (aead->mode == CLUSTER_KEY)
919 salt ^= __be32_to_cpu(ehdr->addr);
920 else if (ehdr->destined)
921 salt ^= tipc_own_addr(net);
922 memcpy(iv, &salt, 4);
923 memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
924
925 /* Prepare request */
926 ehsz = tipc_ehdr_size(ehdr);
927 aead_request_set_tfm(req, tfm);
928 aead_request_set_ad(req, ehsz);
929 aead_request_set_crypt(req, sg, sg, skb->len - ehsz, iv);
930
931 /* Set callback function & data */
932 aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
933 tipc_aead_decrypt_done, skb);
934 rx_ctx = (struct tipc_crypto_rx_ctx *)ctx;
935 rx_ctx->aead = aead;
936 rx_ctx->bearer = b;
937
938 /* Hold bearer */
939 if (unlikely(!tipc_bearer_hold(b))) {
940 rc = -ENODEV;
941 goto exit;
942 }
943
944 /* Now, do decrypt */
945 rc = crypto_aead_decrypt(req);
946 if (rc == -EINPROGRESS || rc == -EBUSY)
947 return rc;
948
949 tipc_bearer_put(b);
950
951 exit:
952 kfree(ctx);
953 TIPC_SKB_CB(skb)->crypto_ctx = NULL;
954 return rc;
955 }
956
tipc_aead_decrypt_done(void * data,int err)957 static void tipc_aead_decrypt_done(void *data, int err)
958 {
959 struct sk_buff *skb = data;
960 struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
961 struct tipc_bearer *b = rx_ctx->bearer;
962 struct tipc_aead *aead = rx_ctx->aead;
963 struct tipc_crypto_stats __percpu *stats = aead->crypto->stats;
964 struct net *net = aead->crypto->net;
965
966 switch (err) {
967 case 0:
968 this_cpu_inc(stats->stat[STAT_ASYNC_OK]);
969 break;
970 case -EINPROGRESS:
971 return;
972 default:
973 this_cpu_inc(stats->stat[STAT_ASYNC_NOK]);
974 break;
975 }
976
977 kfree(rx_ctx);
978 tipc_crypto_rcv_complete(net, aead, b, &skb, err);
979 if (likely(skb)) {
980 if (likely(test_bit(0, &b->up)))
981 tipc_rcv(net, skb, b);
982 else
983 kfree_skb(skb);
984 }
985
986 tipc_bearer_put(b);
987 }
988
tipc_ehdr_size(struct tipc_ehdr * ehdr)989 static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr)
990 {
991 return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
992 }
993
994 /**
995 * tipc_ehdr_validate - Validate an encryption message
996 * @skb: the message buffer
997 *
998 * Return: "true" if this is a valid encryption message, otherwise "false"
999 */
tipc_ehdr_validate(struct sk_buff * skb)1000 bool tipc_ehdr_validate(struct sk_buff *skb)
1001 {
1002 struct tipc_ehdr *ehdr;
1003 int ehsz;
1004
1005 if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE)))
1006 return false;
1007
1008 ehdr = (struct tipc_ehdr *)skb->data;
1009 if (unlikely(ehdr->version != TIPC_EVERSION))
1010 return false;
1011 ehsz = tipc_ehdr_size(ehdr);
1012 if (unlikely(!pskb_may_pull(skb, ehsz)))
1013 return false;
1014 if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE))
1015 return false;
1016
1017 return true;
1018 }
1019
1020 /**
1021 * tipc_ehdr_build - Build TIPC encryption message header
1022 * @net: struct net
1023 * @aead: TX AEAD key to be used for the message encryption
1024 * @tx_key: key id used for the message encryption
1025 * @skb: input/output message skb
1026 * @__rx: RX crypto handle if dest is "known"
1027 *
1028 * Return: the header size if the building is successful, otherwise < 0
1029 */
tipc_ehdr_build(struct net * net,struct tipc_aead * aead,u8 tx_key,struct sk_buff * skb,struct tipc_crypto * __rx)1030 static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
1031 u8 tx_key, struct sk_buff *skb,
1032 struct tipc_crypto *__rx)
1033 {
1034 struct tipc_msg *hdr = buf_msg(skb);
1035 struct tipc_ehdr *ehdr;
1036 u32 user = msg_user(hdr);
1037 u64 seqno;
1038 int ehsz;
1039
1040 /* Make room for encryption header */
1041 ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
1042 WARN_ON(skb_headroom(skb) < ehsz);
1043 ehdr = (struct tipc_ehdr *)skb_push(skb, ehsz);
1044
1045 /* Obtain a seqno first:
1046 * Use the key seqno (= cluster wise) if dest is unknown or we're in
1047 * cluster key mode, otherwise it's better for a per-peer seqno!
1048 */
1049 if (!__rx || aead->mode == CLUSTER_KEY)
1050 seqno = atomic64_inc_return(&aead->seqno);
1051 else
1052 seqno = atomic64_inc_return(&__rx->sndnxt);
1053
1054 /* Revoke the key if seqno is wrapped around */
1055 if (unlikely(!seqno))
1056 return tipc_crypto_key_revoke(net, tx_key);
1057
1058 /* Word 1-2 */
1059 ehdr->seqno = cpu_to_be64(seqno);
1060
1061 /* Words 0, 3- */
1062 ehdr->version = TIPC_EVERSION;
1063 ehdr->user = 0;
1064 ehdr->keepalive = 0;
1065 ehdr->tx_key = tx_key;
1066 ehdr->destined = (__rx) ? 1 : 0;
1067 ehdr->rx_key_active = (__rx) ? __rx->key.active : 0;
1068 ehdr->rx_nokey = (__rx) ? __rx->nokey : 0;
1069 ehdr->master_key = aead->crypto->key_master;
1070 ehdr->reserved_1 = 0;
1071 ehdr->reserved_2 = 0;
1072
1073 switch (user) {
1074 case LINK_CONFIG:
1075 ehdr->user = LINK_CONFIG;
1076 memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN);
1077 break;
1078 default:
1079 if (user == LINK_PROTOCOL && msg_type(hdr) == STATE_MSG) {
1080 ehdr->user = LINK_PROTOCOL;
1081 ehdr->keepalive = msg_is_keepalive(hdr);
1082 }
1083 ehdr->addr = hdr->hdr[3];
1084 break;
1085 }
1086
1087 return ehsz;
1088 }
1089
tipc_crypto_key_set_state(struct tipc_crypto * c,u8 new_passive,u8 new_active,u8 new_pending)1090 static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
1091 u8 new_passive,
1092 u8 new_active,
1093 u8 new_pending)
1094 {
1095 struct tipc_key old = c->key;
1096 char buf[32];
1097
1098 c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) |
1099 ((new_active & KEY_MASK) << (KEY_BITS)) |
1100 ((new_pending & KEY_MASK));
1101
1102 pr_debug("%s: key changing %s ::%pS\n", c->name,
1103 tipc_key_change_dump(old, c->key, buf),
1104 __builtin_return_address(0));
1105 }
1106
1107 /**
1108 * tipc_crypto_key_init - Initiate a new user / AEAD key
1109 * @c: TIPC crypto to which new key is attached
1110 * @ukey: the user key
1111 * @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY)
1112 * @master_key: specify this is a cluster master key
1113 *
1114 * A new TIPC AEAD key will be allocated and initiated with the specified user
1115 * key, then attached to the TIPC crypto.
1116 *
1117 * Return: new key id in case of success, otherwise: < 0
1118 */
tipc_crypto_key_init(struct tipc_crypto * c,struct tipc_aead_key * ukey,u8 mode,bool master_key)1119 int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
1120 u8 mode, bool master_key)
1121 {
1122 struct tipc_aead *aead = NULL;
1123 int rc = 0;
1124
1125 /* Initiate with the new user key */
1126 rc = tipc_aead_init(&aead, ukey, mode);
1127
1128 /* Attach it to the crypto */
1129 if (likely(!rc)) {
1130 rc = tipc_crypto_key_attach(c, aead, 0, master_key);
1131 if (rc < 0)
1132 tipc_aead_free(&aead->rcu);
1133 }
1134
1135 return rc;
1136 }
1137
1138 /**
1139 * tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto
1140 * @c: TIPC crypto to which the new AEAD key is attached
1141 * @aead: the new AEAD key pointer
1142 * @pos: desired slot in the crypto key array, = 0 if any!
1143 * @master_key: specify this is a cluster master key
1144 *
1145 * Return: new key id in case of success, otherwise: -EBUSY
1146 */
tipc_crypto_key_attach(struct tipc_crypto * c,struct tipc_aead * aead,u8 pos,bool master_key)1147 static int tipc_crypto_key_attach(struct tipc_crypto *c,
1148 struct tipc_aead *aead, u8 pos,
1149 bool master_key)
1150 {
1151 struct tipc_key key;
1152 int rc = -EBUSY;
1153 u8 new_key;
1154
1155 spin_lock_bh(&c->lock);
1156 key = c->key;
1157 if (master_key) {
1158 new_key = KEY_MASTER;
1159 goto attach;
1160 }
1161 if (key.active && key.passive)
1162 goto exit;
1163 if (key.pending) {
1164 if (tipc_aead_users(c->aead[key.pending]) > 0)
1165 goto exit;
1166 /* if (pos): ok with replacing, will be aligned when needed */
1167 /* Replace it */
1168 new_key = key.pending;
1169 } else {
1170 if (pos) {
1171 if (key.active && pos != key_next(key.active)) {
1172 key.passive = pos;
1173 new_key = pos;
1174 goto attach;
1175 } else if (!key.active && !key.passive) {
1176 key.pending = pos;
1177 new_key = pos;
1178 goto attach;
1179 }
1180 }
1181 key.pending = key_next(key.active ?: key.passive);
1182 new_key = key.pending;
1183 }
1184
1185 attach:
1186 aead->crypto = c;
1187 aead->gen = (is_tx(c)) ? ++c->key_gen : c->key_gen;
1188 tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock);
1189 if (likely(c->key.keys != key.keys))
1190 tipc_crypto_key_set_state(c, key.passive, key.active,
1191 key.pending);
1192 c->working = 1;
1193 c->nokey = 0;
1194 c->key_master |= master_key;
1195 rc = new_key;
1196
1197 exit:
1198 spin_unlock_bh(&c->lock);
1199 return rc;
1200 }
1201
tipc_crypto_key_flush(struct tipc_crypto * c)1202 void tipc_crypto_key_flush(struct tipc_crypto *c)
1203 {
1204 struct tipc_crypto *tx, *rx;
1205 int k;
1206
1207 spin_lock_bh(&c->lock);
1208 if (is_rx(c)) {
1209 /* Try to cancel pending work */
1210 rx = c;
1211 tx = tipc_net(rx->net)->crypto_tx;
1212 if (cancel_delayed_work(&rx->work)) {
1213 kfree(rx->skey);
1214 rx->skey = NULL;
1215 atomic_xchg(&rx->key_distr, 0);
1216 tipc_node_put(rx->node);
1217 }
1218 /* RX stopping => decrease TX key users if any */
1219 k = atomic_xchg(&rx->peer_rx_active, 0);
1220 if (k) {
1221 tipc_aead_users_dec(tx->aead[k], 0);
1222 /* Mark the point TX key users changed */
1223 tx->timer1 = jiffies;
1224 }
1225 }
1226
1227 c->flags = 0;
1228 tipc_crypto_key_set_state(c, 0, 0, 0);
1229 for (k = KEY_MIN; k <= KEY_MAX; k++)
1230 tipc_crypto_key_detach(c->aead[k], &c->lock);
1231 atomic64_set(&c->sndnxt, 0);
1232 spin_unlock_bh(&c->lock);
1233 }
1234
1235 /**
1236 * tipc_crypto_key_try_align - Align RX keys if possible
1237 * @rx: RX crypto handle
1238 * @new_pending: new pending slot if aligned (= TX key from peer)
1239 *
1240 * Peer has used an unknown key slot, this only happens when peer has left and
1241 * rejoned, or we are newcomer.
1242 * That means, there must be no active key but a pending key at unaligned slot.
1243 * If so, we try to move the pending key to the new slot.
1244 * Note: A potential passive key can exist, it will be shifted correspondingly!
1245 *
1246 * Return: "true" if key is successfully aligned, otherwise "false"
1247 */
tipc_crypto_key_try_align(struct tipc_crypto * rx,u8 new_pending)1248 static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
1249 {
1250 struct tipc_aead *tmp1, *tmp2 = NULL;
1251 struct tipc_key key;
1252 bool aligned = false;
1253 u8 new_passive = 0;
1254 int x;
1255
1256 spin_lock(&rx->lock);
1257 key = rx->key;
1258 if (key.pending == new_pending) {
1259 aligned = true;
1260 goto exit;
1261 }
1262 if (key.active)
1263 goto exit;
1264 if (!key.pending)
1265 goto exit;
1266 if (tipc_aead_users(rx->aead[key.pending]) > 0)
1267 goto exit;
1268
1269 /* Try to "isolate" this pending key first */
1270 tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock);
1271 if (!refcount_dec_if_one(&tmp1->refcnt))
1272 goto exit;
1273 rcu_assign_pointer(rx->aead[key.pending], NULL);
1274
1275 /* Move passive key if any */
1276 if (key.passive) {
1277 tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock));
1278 x = (key.passive - key.pending + new_pending) % KEY_MAX;
1279 new_passive = (x <= 0) ? x + KEY_MAX : x;
1280 }
1281
1282 /* Re-allocate the key(s) */
1283 tipc_crypto_key_set_state(rx, new_passive, 0, new_pending);
1284 rcu_assign_pointer(rx->aead[new_pending], tmp1);
1285 if (new_passive)
1286 rcu_assign_pointer(rx->aead[new_passive], tmp2);
1287 refcount_set(&tmp1->refcnt, 1);
1288 aligned = true;
1289 pr_info_ratelimited("%s: key[%d] -> key[%d]\n", rx->name, key.pending,
1290 new_pending);
1291
1292 exit:
1293 spin_unlock(&rx->lock);
1294 return aligned;
1295 }
1296
1297 /**
1298 * tipc_crypto_key_pick_tx - Pick one TX key for message decryption
1299 * @tx: TX crypto handle
1300 * @rx: RX crypto handle (can be NULL)
1301 * @skb: the message skb which will be decrypted later
1302 * @tx_key: peer TX key id
1303 *
1304 * This function looks up the existing TX keys and pick one which is suitable
1305 * for the message decryption, that must be a cluster key and not used before
1306 * on the same message (i.e. recursive).
1307 *
1308 * Return: the TX AEAD key handle in case of success, otherwise NULL
1309 */
tipc_crypto_key_pick_tx(struct tipc_crypto * tx,struct tipc_crypto * rx,struct sk_buff * skb,u8 tx_key)1310 static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
1311 struct tipc_crypto *rx,
1312 struct sk_buff *skb,
1313 u8 tx_key)
1314 {
1315 struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb);
1316 struct tipc_aead *aead = NULL;
1317 struct tipc_key key = tx->key;
1318 u8 k, i = 0;
1319
1320 /* Initialize data if not yet */
1321 if (!skb_cb->tx_clone_deferred) {
1322 skb_cb->tx_clone_deferred = 1;
1323 memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1324 }
1325
1326 skb_cb->tx_clone_ctx.rx = rx;
1327 if (++skb_cb->tx_clone_ctx.recurs > 2)
1328 return NULL;
1329
1330 /* Pick one TX key */
1331 spin_lock(&tx->lock);
1332 if (tx_key == KEY_MASTER) {
1333 aead = tipc_aead_rcu_ptr(tx->aead[KEY_MASTER], &tx->lock);
1334 goto done;
1335 }
1336 do {
1337 k = (i == 0) ? key.pending :
1338 ((i == 1) ? key.active : key.passive);
1339 if (!k)
1340 continue;
1341 aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock);
1342 if (!aead)
1343 continue;
1344 if (aead->mode != CLUSTER_KEY ||
1345 aead == skb_cb->tx_clone_ctx.last) {
1346 aead = NULL;
1347 continue;
1348 }
1349 /* Ok, found one cluster key */
1350 skb_cb->tx_clone_ctx.last = aead;
1351 WARN_ON(skb->next);
1352 skb->next = skb_clone(skb, GFP_ATOMIC);
1353 if (unlikely(!skb->next))
1354 pr_warn("Failed to clone skb for next round if any\n");
1355 break;
1356 } while (++i < 3);
1357
1358 done:
1359 if (likely(aead))
1360 WARN_ON(!refcount_inc_not_zero(&aead->refcnt));
1361 spin_unlock(&tx->lock);
1362
1363 return aead;
1364 }
1365
1366 /**
1367 * tipc_crypto_key_synch: Synch own key data according to peer key status
1368 * @rx: RX crypto handle
1369 * @skb: TIPCv2 message buffer (incl. the ehdr from peer)
1370 *
1371 * This function updates the peer node related data as the peer RX active key
1372 * has changed, so the number of TX keys' users on this node are increased and
1373 * decreased correspondingly.
1374 *
1375 * It also considers if peer has no key, then we need to make own master key
1376 * (if any) taking over i.e. starting grace period and also trigger key
1377 * distributing process.
1378 *
1379 * The "per-peer" sndnxt is also reset when the peer key has switched.
1380 */
tipc_crypto_key_synch(struct tipc_crypto * rx,struct sk_buff * skb)1381 static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb)
1382 {
1383 struct tipc_ehdr *ehdr = (struct tipc_ehdr *)skb_network_header(skb);
1384 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
1385 struct tipc_msg *hdr = buf_msg(skb);
1386 u32 self = tipc_own_addr(rx->net);
1387 u8 cur, new;
1388 unsigned long delay;
1389
1390 /* Update RX 'key_master' flag according to peer, also mark "legacy" if
1391 * a peer has no master key.
1392 */
1393 rx->key_master = ehdr->master_key;
1394 if (!rx->key_master)
1395 tx->legacy_user = 1;
1396
1397 /* For later cases, apply only if message is destined to this node */
1398 if (!ehdr->destined || msg_short(hdr) || msg_destnode(hdr) != self)
1399 return;
1400
1401 /* Case 1: Peer has no keys, let's make master key take over */
1402 if (ehdr->rx_nokey) {
1403 /* Set or extend grace period */
1404 tx->timer2 = jiffies;
1405 /* Schedule key distributing for the peer if not yet */
1406 if (tx->key.keys &&
1407 !atomic_cmpxchg(&rx->key_distr, 0, KEY_DISTR_SCHED)) {
1408 get_random_bytes(&delay, 2);
1409 delay %= 5;
1410 delay = msecs_to_jiffies(500 * ++delay);
1411 if (queue_delayed_work(tx->wq, &rx->work, delay))
1412 tipc_node_get(rx->node);
1413 }
1414 } else {
1415 /* Cancel a pending key distributing if any */
1416 atomic_xchg(&rx->key_distr, 0);
1417 }
1418
1419 /* Case 2: Peer RX active key has changed, let's update own TX users */
1420 cur = atomic_read(&rx->peer_rx_active);
1421 new = ehdr->rx_key_active;
1422 if (tx->key.keys &&
1423 cur != new &&
1424 atomic_cmpxchg(&rx->peer_rx_active, cur, new) == cur) {
1425 if (new)
1426 tipc_aead_users_inc(tx->aead[new], INT_MAX);
1427 if (cur)
1428 tipc_aead_users_dec(tx->aead[cur], 0);
1429
1430 atomic64_set(&rx->sndnxt, 0);
1431 /* Mark the point TX key users changed */
1432 tx->timer1 = jiffies;
1433
1434 pr_debug("%s: key users changed %d-- %d++, peer %s\n",
1435 tx->name, cur, new, rx->name);
1436 }
1437 }
1438
tipc_crypto_key_revoke(struct net * net,u8 tx_key)1439 static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
1440 {
1441 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1442 struct tipc_key key;
1443
1444 spin_lock_bh(&tx->lock);
1445 key = tx->key;
1446 WARN_ON(!key.active || tx_key != key.active);
1447
1448 /* Free the active key */
1449 tipc_crypto_key_set_state(tx, key.passive, 0, key.pending);
1450 tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1451 spin_unlock_bh(&tx->lock);
1452
1453 pr_warn("%s: key is revoked\n", tx->name);
1454 return -EKEYREVOKED;
1455 }
1456
tipc_crypto_start(struct tipc_crypto ** crypto,struct net * net,struct tipc_node * node)1457 int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
1458 struct tipc_node *node)
1459 {
1460 struct tipc_crypto *c;
1461
1462 if (*crypto)
1463 return -EEXIST;
1464
1465 /* Allocate crypto */
1466 c = kzalloc(sizeof(*c), GFP_ATOMIC);
1467 if (!c)
1468 return -ENOMEM;
1469
1470 /* Allocate workqueue on TX */
1471 if (!node) {
1472 c->wq = alloc_ordered_workqueue("tipc_crypto", 0);
1473 if (!c->wq) {
1474 kfree(c);
1475 return -ENOMEM;
1476 }
1477 }
1478
1479 /* Allocate statistic structure */
1480 c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
1481 if (!c->stats) {
1482 if (c->wq)
1483 destroy_workqueue(c->wq);
1484 kfree_sensitive(c);
1485 return -ENOMEM;
1486 }
1487
1488 c->flags = 0;
1489 c->net = net;
1490 c->node = node;
1491 get_random_bytes(&c->key_gen, 2);
1492 tipc_crypto_key_set_state(c, 0, 0, 0);
1493 atomic_set(&c->key_distr, 0);
1494 atomic_set(&c->peer_rx_active, 0);
1495 atomic64_set(&c->sndnxt, 0);
1496 c->timer1 = jiffies;
1497 c->timer2 = jiffies;
1498 c->rekeying_intv = TIPC_REKEYING_INTV_DEF;
1499 spin_lock_init(&c->lock);
1500 scnprintf(c->name, 48, "%s(%s)", (is_rx(c)) ? "RX" : "TX",
1501 (is_rx(c)) ? tipc_node_get_id_str(c->node) :
1502 tipc_own_id_string(c->net));
1503
1504 if (is_rx(c))
1505 INIT_DELAYED_WORK(&c->work, tipc_crypto_work_rx);
1506 else
1507 INIT_DELAYED_WORK(&c->work, tipc_crypto_work_tx);
1508
1509 *crypto = c;
1510 return 0;
1511 }
1512
tipc_crypto_stop(struct tipc_crypto ** crypto)1513 void tipc_crypto_stop(struct tipc_crypto **crypto)
1514 {
1515 struct tipc_crypto *c = *crypto;
1516 u8 k;
1517
1518 if (!c)
1519 return;
1520
1521 /* Flush any queued works & destroy wq */
1522 if (is_tx(c)) {
1523 c->rekeying_intv = 0;
1524 cancel_delayed_work_sync(&c->work);
1525 destroy_workqueue(c->wq);
1526 }
1527
1528 /* Release AEAD keys */
1529 rcu_read_lock();
1530 for (k = KEY_MIN; k <= KEY_MAX; k++)
1531 tipc_aead_put(rcu_dereference(c->aead[k]));
1532 rcu_read_unlock();
1533 pr_debug("%s: has been stopped\n", c->name);
1534
1535 /* Free this crypto statistics */
1536 free_percpu(c->stats);
1537
1538 *crypto = NULL;
1539 kfree_sensitive(c);
1540 }
1541
tipc_crypto_timeout(struct tipc_crypto * rx)1542 void tipc_crypto_timeout(struct tipc_crypto *rx)
1543 {
1544 struct tipc_net *tn = tipc_net(rx->net);
1545 struct tipc_crypto *tx = tn->crypto_tx;
1546 struct tipc_key key;
1547 int cmd;
1548
1549 /* TX pending: taking all users & stable -> active */
1550 spin_lock(&tx->lock);
1551 key = tx->key;
1552 if (key.active && tipc_aead_users(tx->aead[key.active]) > 0)
1553 goto s1;
1554 if (!key.pending || tipc_aead_users(tx->aead[key.pending]) <= 0)
1555 goto s1;
1556 if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_TIME))
1557 goto s1;
1558
1559 tipc_crypto_key_set_state(tx, key.passive, key.pending, 0);
1560 if (key.active)
1561 tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1562 this_cpu_inc(tx->stats->stat[STAT_SWITCHES]);
1563 pr_info("%s: key[%d] is activated\n", tx->name, key.pending);
1564
1565 s1:
1566 spin_unlock(&tx->lock);
1567
1568 /* RX pending: having user -> active */
1569 spin_lock(&rx->lock);
1570 key = rx->key;
1571 if (!key.pending || tipc_aead_users(rx->aead[key.pending]) <= 0)
1572 goto s2;
1573
1574 if (key.active)
1575 key.passive = key.active;
1576 key.active = key.pending;
1577 rx->timer2 = jiffies;
1578 tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
1579 this_cpu_inc(rx->stats->stat[STAT_SWITCHES]);
1580 pr_info("%s: key[%d] is activated\n", rx->name, key.pending);
1581 goto s5;
1582
1583 s2:
1584 /* RX pending: not working -> remove */
1585 if (!key.pending || tipc_aead_users(rx->aead[key.pending]) > -10)
1586 goto s3;
1587
1588 tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
1589 tipc_crypto_key_detach(rx->aead[key.pending], &rx->lock);
1590 pr_debug("%s: key[%d] is removed\n", rx->name, key.pending);
1591 goto s5;
1592
1593 s3:
1594 /* RX active: timed out or no user -> pending */
1595 if (!key.active)
1596 goto s4;
1597 if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM) &&
1598 tipc_aead_users(rx->aead[key.active]) > 0)
1599 goto s4;
1600
1601 if (key.pending)
1602 key.passive = key.active;
1603 else
1604 key.pending = key.active;
1605 rx->timer2 = jiffies;
1606 tipc_crypto_key_set_state(rx, key.passive, 0, key.pending);
1607 tipc_aead_users_set(rx->aead[key.pending], 0);
1608 pr_debug("%s: key[%d] is deactivated\n", rx->name, key.active);
1609 goto s5;
1610
1611 s4:
1612 /* RX passive: outdated or not working -> free */
1613 if (!key.passive)
1614 goto s5;
1615 if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM) &&
1616 tipc_aead_users(rx->aead[key.passive]) > -10)
1617 goto s5;
1618
1619 tipc_crypto_key_set_state(rx, 0, key.active, key.pending);
1620 tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock);
1621 pr_debug("%s: key[%d] is freed\n", rx->name, key.passive);
1622
1623 s5:
1624 spin_unlock(&rx->lock);
1625
1626 /* Relax it here, the flag will be set again if it really is, but only
1627 * when we are not in grace period for safety!
1628 */
1629 if (time_after(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD))
1630 tx->legacy_user = 0;
1631
1632 /* Limit max_tfms & do debug commands if needed */
1633 if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM))
1634 return;
1635
1636 cmd = sysctl_tipc_max_tfms;
1637 sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF;
1638 tipc_crypto_do_cmd(rx->net, cmd);
1639 }
1640
tipc_crypto_clone_msg(struct net * net,struct sk_buff * _skb,struct tipc_bearer * b,struct tipc_media_addr * dst,struct tipc_node * __dnode,u8 type)1641 static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
1642 struct tipc_bearer *b,
1643 struct tipc_media_addr *dst,
1644 struct tipc_node *__dnode, u8 type)
1645 {
1646 struct sk_buff *skb;
1647
1648 skb = skb_clone(_skb, GFP_ATOMIC);
1649 if (skb) {
1650 TIPC_SKB_CB(skb)->xmit_type = type;
1651 tipc_crypto_xmit(net, &skb, b, dst, __dnode);
1652 if (skb)
1653 b->media->send_msg(net, skb, b, dst);
1654 }
1655 }
1656
1657 /**
1658 * tipc_crypto_xmit - Build & encrypt TIPC message for xmit
1659 * @net: struct net
1660 * @skb: input/output message skb pointer
1661 * @b: bearer used for xmit later
1662 * @dst: destination media address
1663 * @__dnode: destination node for reference if any
1664 *
1665 * First, build an encryption message header on the top of the message, then
1666 * encrypt the original TIPC message by using the pending, master or active
1667 * key with this preference order.
1668 * If the encryption is successful, the encrypted skb is returned directly or
1669 * via the callback.
1670 * Otherwise, the skb is freed!
1671 *
1672 * Return:
1673 * * 0 : the encryption has succeeded (or no encryption)
1674 * * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made
1675 * * -ENOKEK : the encryption has failed due to no key
1676 * * -EKEYREVOKED : the encryption has failed due to key revoked
1677 * * -ENOMEM : the encryption has failed due to no memory
1678 * * < 0 : the encryption has failed due to other reasons
1679 */
tipc_crypto_xmit(struct net * net,struct sk_buff ** skb,struct tipc_bearer * b,struct tipc_media_addr * dst,struct tipc_node * __dnode)1680 int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
1681 struct tipc_bearer *b, struct tipc_media_addr *dst,
1682 struct tipc_node *__dnode)
1683 {
1684 struct tipc_crypto *__rx = tipc_node_crypto_rx(__dnode);
1685 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1686 struct tipc_crypto_stats __percpu *stats = tx->stats;
1687 struct tipc_msg *hdr = buf_msg(*skb);
1688 struct tipc_key key = tx->key;
1689 struct tipc_aead *aead = NULL;
1690 u32 user = msg_user(hdr);
1691 u32 type = msg_type(hdr);
1692 int rc = -ENOKEY;
1693 u8 tx_key = 0;
1694
1695 /* No encryption? */
1696 if (!tx->working)
1697 return 0;
1698
1699 /* Pending key if peer has active on it or probing time */
1700 if (unlikely(key.pending)) {
1701 tx_key = key.pending;
1702 if (!tx->key_master && !key.active)
1703 goto encrypt;
1704 if (__rx && atomic_read(&__rx->peer_rx_active) == tx_key)
1705 goto encrypt;
1706 if (TIPC_SKB_CB(*skb)->xmit_type == SKB_PROBING) {
1707 pr_debug("%s: probing for key[%d]\n", tx->name,
1708 key.pending);
1709 goto encrypt;
1710 }
1711 if (user == LINK_CONFIG || user == LINK_PROTOCOL)
1712 tipc_crypto_clone_msg(net, *skb, b, dst, __dnode,
1713 SKB_PROBING);
1714 }
1715
1716 /* Master key if this is a *vital* message or in grace period */
1717 if (tx->key_master) {
1718 tx_key = KEY_MASTER;
1719 if (!key.active)
1720 goto encrypt;
1721 if (TIPC_SKB_CB(*skb)->xmit_type == SKB_GRACING) {
1722 pr_debug("%s: gracing for msg (%d %d)\n", tx->name,
1723 user, type);
1724 goto encrypt;
1725 }
1726 if (user == LINK_CONFIG ||
1727 (user == LINK_PROTOCOL && type == RESET_MSG) ||
1728 (user == MSG_CRYPTO && type == KEY_DISTR_MSG) ||
1729 time_before(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) {
1730 if (__rx && __rx->key_master &&
1731 !atomic_read(&__rx->peer_rx_active))
1732 goto encrypt;
1733 if (!__rx) {
1734 if (likely(!tx->legacy_user))
1735 goto encrypt;
1736 tipc_crypto_clone_msg(net, *skb, b, dst,
1737 __dnode, SKB_GRACING);
1738 }
1739 }
1740 }
1741
1742 /* Else, use the active key if any */
1743 if (likely(key.active)) {
1744 tx_key = key.active;
1745 goto encrypt;
1746 }
1747
1748 goto exit;
1749
1750 encrypt:
1751 aead = tipc_aead_get(tx->aead[tx_key]);
1752 if (unlikely(!aead))
1753 goto exit;
1754 rc = tipc_ehdr_build(net, aead, tx_key, *skb, __rx);
1755 if (likely(rc > 0))
1756 rc = tipc_aead_encrypt(aead, *skb, b, dst, __dnode);
1757
1758 exit:
1759 switch (rc) {
1760 case 0:
1761 this_cpu_inc(stats->stat[STAT_OK]);
1762 break;
1763 case -EINPROGRESS:
1764 case -EBUSY:
1765 this_cpu_inc(stats->stat[STAT_ASYNC]);
1766 *skb = NULL;
1767 return rc;
1768 default:
1769 this_cpu_inc(stats->stat[STAT_NOK]);
1770 if (rc == -ENOKEY)
1771 this_cpu_inc(stats->stat[STAT_NOKEYS]);
1772 else if (rc == -EKEYREVOKED)
1773 this_cpu_inc(stats->stat[STAT_BADKEYS]);
1774 kfree_skb(*skb);
1775 *skb = NULL;
1776 break;
1777 }
1778
1779 tipc_aead_put(aead);
1780 return rc;
1781 }
1782
1783 /**
1784 * tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer
1785 * @net: struct net
1786 * @rx: RX crypto handle
1787 * @skb: input/output message skb pointer
1788 * @b: bearer where the message has been received
1789 *
1790 * If the decryption is successful, the decrypted skb is returned directly or
1791 * as the callback, the encryption header and auth tag will be trimed out
1792 * before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete().
1793 * Otherwise, the skb will be freed!
1794 * Note: RX key(s) can be re-aligned, or in case of no key suitable, TX
1795 * cluster key(s) can be taken for decryption (- recursive).
1796 *
1797 * Return:
1798 * * 0 : the decryption has successfully completed
1799 * * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made
1800 * * -ENOKEY : the decryption has failed due to no key
1801 * * -EBADMSG : the decryption has failed due to bad message
1802 * * -ENOMEM : the decryption has failed due to no memory
1803 * * < 0 : the decryption has failed due to other reasons
1804 */
tipc_crypto_rcv(struct net * net,struct tipc_crypto * rx,struct sk_buff ** skb,struct tipc_bearer * b)1805 int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
1806 struct sk_buff **skb, struct tipc_bearer *b)
1807 {
1808 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1809 struct tipc_crypto_stats __percpu *stats;
1810 struct tipc_aead *aead = NULL;
1811 struct tipc_key key;
1812 int rc = -ENOKEY;
1813 u8 tx_key, n;
1814
1815 tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key;
1816
1817 /* New peer?
1818 * Let's try with TX key (i.e. cluster mode) & verify the skb first!
1819 */
1820 if (unlikely(!rx || tx_key == KEY_MASTER))
1821 goto pick_tx;
1822
1823 /* Pick RX key according to TX key if any */
1824 key = rx->key;
1825 if (tx_key == key.active || tx_key == key.pending ||
1826 tx_key == key.passive)
1827 goto decrypt;
1828
1829 /* Unknown key, let's try to align RX key(s) */
1830 if (tipc_crypto_key_try_align(rx, tx_key))
1831 goto decrypt;
1832
1833 pick_tx:
1834 /* No key suitable? Try to pick one from TX... */
1835 aead = tipc_crypto_key_pick_tx(tx, rx, *skb, tx_key);
1836 if (aead)
1837 goto decrypt;
1838 goto exit;
1839
1840 decrypt:
1841 rcu_read_lock();
1842 if (!aead)
1843 aead = tipc_aead_get(rx->aead[tx_key]);
1844 rc = tipc_aead_decrypt(net, aead, *skb, b);
1845 rcu_read_unlock();
1846
1847 exit:
1848 stats = ((rx) ?: tx)->stats;
1849 switch (rc) {
1850 case 0:
1851 this_cpu_inc(stats->stat[STAT_OK]);
1852 break;
1853 case -EINPROGRESS:
1854 case -EBUSY:
1855 this_cpu_inc(stats->stat[STAT_ASYNC]);
1856 *skb = NULL;
1857 return rc;
1858 default:
1859 this_cpu_inc(stats->stat[STAT_NOK]);
1860 if (rc == -ENOKEY) {
1861 kfree_skb(*skb);
1862 *skb = NULL;
1863 if (rx) {
1864 /* Mark rx->nokey only if we dont have a
1865 * pending received session key, nor a newer
1866 * one i.e. in the next slot.
1867 */
1868 n = key_next(tx_key);
1869 rx->nokey = !(rx->skey ||
1870 rcu_access_pointer(rx->aead[n]));
1871 pr_debug_ratelimited("%s: nokey %d, key %d/%x\n",
1872 rx->name, rx->nokey,
1873 tx_key, rx->key.keys);
1874 tipc_node_put(rx->node);
1875 }
1876 this_cpu_inc(stats->stat[STAT_NOKEYS]);
1877 return rc;
1878 } else if (rc == -EBADMSG) {
1879 this_cpu_inc(stats->stat[STAT_BADMSGS]);
1880 }
1881 break;
1882 }
1883
1884 tipc_crypto_rcv_complete(net, aead, b, skb, rc);
1885 return rc;
1886 }
1887
tipc_crypto_rcv_complete(struct net * net,struct tipc_aead * aead,struct tipc_bearer * b,struct sk_buff ** skb,int err)1888 static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
1889 struct tipc_bearer *b,
1890 struct sk_buff **skb, int err)
1891 {
1892 struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb);
1893 struct tipc_crypto *rx = aead->crypto;
1894 struct tipc_aead *tmp = NULL;
1895 struct tipc_ehdr *ehdr;
1896 struct tipc_node *n;
1897
1898 /* Is this completed by TX? */
1899 if (unlikely(is_tx(aead->crypto))) {
1900 rx = skb_cb->tx_clone_ctx.rx;
1901 pr_debug("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n",
1902 (rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead,
1903 (*skb)->next, skb_cb->flags);
1904 pr_debug("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n",
1905 skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last,
1906 aead->crypto->aead[1], aead->crypto->aead[2],
1907 aead->crypto->aead[3]);
1908 if (unlikely(err)) {
1909 if (err == -EBADMSG && (*skb)->next)
1910 tipc_rcv(net, (*skb)->next, b);
1911 goto free_skb;
1912 }
1913
1914 if (likely((*skb)->next)) {
1915 kfree_skb((*skb)->next);
1916 (*skb)->next = NULL;
1917 }
1918 ehdr = (struct tipc_ehdr *)(*skb)->data;
1919 if (!rx) {
1920 WARN_ON(ehdr->user != LINK_CONFIG);
1921 n = tipc_node_create(net, 0, ehdr->id, 0xffffu, 0,
1922 true);
1923 rx = tipc_node_crypto_rx(n);
1924 if (unlikely(!rx))
1925 goto free_skb;
1926 }
1927
1928 /* Ignore cloning if it was TX master key */
1929 if (ehdr->tx_key == KEY_MASTER)
1930 goto rcv;
1931 if (tipc_aead_clone(&tmp, aead) < 0)
1932 goto rcv;
1933 WARN_ON(!refcount_inc_not_zero(&tmp->refcnt));
1934 if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key, false) < 0) {
1935 tipc_aead_free(&tmp->rcu);
1936 goto rcv;
1937 }
1938 tipc_aead_put(aead);
1939 aead = tmp;
1940 }
1941
1942 if (unlikely(err)) {
1943 tipc_aead_users_dec((struct tipc_aead __force __rcu *)aead, INT_MIN);
1944 goto free_skb;
1945 }
1946
1947 /* Set the RX key's user */
1948 tipc_aead_users_set((struct tipc_aead __force __rcu *)aead, 1);
1949
1950 /* Mark this point, RX works */
1951 rx->timer1 = jiffies;
1952
1953 rcv:
1954 /* Remove ehdr & auth. tag prior to tipc_rcv() */
1955 ehdr = (struct tipc_ehdr *)(*skb)->data;
1956
1957 /* Mark this point, RX passive still works */
1958 if (rx->key.passive && ehdr->tx_key == rx->key.passive)
1959 rx->timer2 = jiffies;
1960
1961 skb_reset_network_header(*skb);
1962 skb_pull(*skb, tipc_ehdr_size(ehdr));
1963 if (pskb_trim(*skb, (*skb)->len - aead->authsize))
1964 goto free_skb;
1965
1966 /* Validate TIPCv2 message */
1967 if (unlikely(!tipc_msg_validate(skb))) {
1968 pr_err_ratelimited("Packet dropped after decryption!\n");
1969 goto free_skb;
1970 }
1971
1972 /* Ok, everything's fine, try to synch own keys according to peers' */
1973 tipc_crypto_key_synch(rx, *skb);
1974
1975 /* Re-fetch skb cb as skb might be changed in tipc_msg_validate */
1976 skb_cb = TIPC_SKB_CB(*skb);
1977
1978 /* Mark skb decrypted */
1979 skb_cb->decrypted = 1;
1980
1981 /* Clear clone cxt if any */
1982 if (likely(!skb_cb->tx_clone_deferred))
1983 goto exit;
1984 skb_cb->tx_clone_deferred = 0;
1985 memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1986 goto exit;
1987
1988 free_skb:
1989 kfree_skb(*skb);
1990 *skb = NULL;
1991
1992 exit:
1993 tipc_aead_put(aead);
1994 if (rx)
1995 tipc_node_put(rx->node);
1996 }
1997
tipc_crypto_do_cmd(struct net * net,int cmd)1998 static void tipc_crypto_do_cmd(struct net *net, int cmd)
1999 {
2000 struct tipc_net *tn = tipc_net(net);
2001 struct tipc_crypto *tx = tn->crypto_tx, *rx;
2002 struct list_head *p;
2003 unsigned int stat;
2004 int i, j, cpu;
2005 char buf[200];
2006
2007 /* Currently only one command is supported */
2008 switch (cmd) {
2009 case 0xfff1:
2010 goto print_stats;
2011 default:
2012 return;
2013 }
2014
2015 print_stats:
2016 /* Print a header */
2017 pr_info("\n=============== TIPC Crypto Statistics ===============\n\n");
2018
2019 /* Print key status */
2020 pr_info("Key status:\n");
2021 pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net),
2022 tipc_crypto_key_dump(tx, buf));
2023
2024 rcu_read_lock();
2025 for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2026 rx = tipc_node_crypto_rx_by_list(p);
2027 pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node),
2028 tipc_crypto_key_dump(rx, buf));
2029 }
2030 rcu_read_unlock();
2031
2032 /* Print crypto statistics */
2033 for (i = 0, j = 0; i < MAX_STATS; i++)
2034 j += scnprintf(buf + j, 200 - j, "|%11s ", hstats[i]);
2035 pr_info("Counter %s", buf);
2036
2037 memset(buf, '-', 115);
2038 buf[115] = '\0';
2039 pr_info("%s\n", buf);
2040
2041 j = scnprintf(buf, 200, "TX(%7.7s) ", tipc_own_id_string(net));
2042 for_each_possible_cpu(cpu) {
2043 for (i = 0; i < MAX_STATS; i++) {
2044 stat = per_cpu_ptr(tx->stats, cpu)->stat[i];
2045 j += scnprintf(buf + j, 200 - j, "|%11d ", stat);
2046 }
2047 pr_info("%s", buf);
2048 j = scnprintf(buf, 200, "%12s", " ");
2049 }
2050
2051 rcu_read_lock();
2052 for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2053 rx = tipc_node_crypto_rx_by_list(p);
2054 j = scnprintf(buf, 200, "RX(%7.7s) ",
2055 tipc_node_get_id_str(rx->node));
2056 for_each_possible_cpu(cpu) {
2057 for (i = 0; i < MAX_STATS; i++) {
2058 stat = per_cpu_ptr(rx->stats, cpu)->stat[i];
2059 j += scnprintf(buf + j, 200 - j, "|%11d ",
2060 stat);
2061 }
2062 pr_info("%s", buf);
2063 j = scnprintf(buf, 200, "%12s", " ");
2064 }
2065 }
2066 rcu_read_unlock();
2067
2068 pr_info("\n======================== Done ========================\n");
2069 }
2070
tipc_crypto_key_dump(struct tipc_crypto * c,char * buf)2071 static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf)
2072 {
2073 struct tipc_key key = c->key;
2074 struct tipc_aead *aead;
2075 int k, i = 0;
2076 char *s;
2077
2078 for (k = KEY_MIN; k <= KEY_MAX; k++) {
2079 if (k == KEY_MASTER) {
2080 if (is_rx(c))
2081 continue;
2082 if (time_before(jiffies,
2083 c->timer2 + TIPC_TX_GRACE_PERIOD))
2084 s = "ACT";
2085 else
2086 s = "PAS";
2087 } else {
2088 if (k == key.passive)
2089 s = "PAS";
2090 else if (k == key.active)
2091 s = "ACT";
2092 else if (k == key.pending)
2093 s = "PEN";
2094 else
2095 s = "-";
2096 }
2097 i += scnprintf(buf + i, 200 - i, "\tKey%d: %s", k, s);
2098
2099 rcu_read_lock();
2100 aead = rcu_dereference(c->aead[k]);
2101 if (aead)
2102 i += scnprintf(buf + i, 200 - i,
2103 "{\"0x...%s\", \"%s\"}/%d:%d",
2104 aead->hint,
2105 (aead->mode == CLUSTER_KEY) ? "c" : "p",
2106 atomic_read(&aead->users),
2107 refcount_read(&aead->refcnt));
2108 rcu_read_unlock();
2109 i += scnprintf(buf + i, 200 - i, "\n");
2110 }
2111
2112 if (is_rx(c))
2113 i += scnprintf(buf + i, 200 - i, "\tPeer RX active: %d\n",
2114 atomic_read(&c->peer_rx_active));
2115
2116 return buf;
2117 }
2118
tipc_key_change_dump(struct tipc_key old,struct tipc_key new,char * buf)2119 static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
2120 char *buf)
2121 {
2122 struct tipc_key *key = &old;
2123 int k, i = 0;
2124 char *s;
2125
2126 /* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */
2127 again:
2128 i += scnprintf(buf + i, 32 - i, "[");
2129 for (k = KEY_1; k <= KEY_3; k++) {
2130 if (k == key->passive)
2131 s = "pas";
2132 else if (k == key->active)
2133 s = "act";
2134 else if (k == key->pending)
2135 s = "pen";
2136 else
2137 s = "-";
2138 i += scnprintf(buf + i, 32 - i,
2139 (k != KEY_3) ? "%s " : "%s", s);
2140 }
2141 if (key != &new) {
2142 i += scnprintf(buf + i, 32 - i, "] -> ");
2143 key = &new;
2144 goto again;
2145 }
2146 i += scnprintf(buf + i, 32 - i, "]");
2147 return buf;
2148 }
2149
2150 /**
2151 * tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point
2152 * @net: the struct net
2153 * @skb: the receiving message buffer
2154 */
tipc_crypto_msg_rcv(struct net * net,struct sk_buff * skb)2155 void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb)
2156 {
2157 struct tipc_crypto *rx;
2158 struct tipc_msg *hdr;
2159
2160 if (unlikely(skb_linearize(skb)))
2161 goto exit;
2162
2163 hdr = buf_msg(skb);
2164 rx = tipc_node_crypto_rx_by_addr(net, msg_prevnode(hdr));
2165 if (unlikely(!rx))
2166 goto exit;
2167
2168 switch (msg_type(hdr)) {
2169 case KEY_DISTR_MSG:
2170 if (tipc_crypto_key_rcv(rx, hdr))
2171 goto exit;
2172 break;
2173 default:
2174 break;
2175 }
2176
2177 tipc_node_put(rx->node);
2178
2179 exit:
2180 kfree_skb(skb);
2181 }
2182
2183 /**
2184 * tipc_crypto_key_distr - Distribute a TX key
2185 * @tx: the TX crypto
2186 * @key: the key's index
2187 * @dest: the destination tipc node, = NULL if distributing to all nodes
2188 *
2189 * Return: 0 in case of success, otherwise < 0
2190 */
tipc_crypto_key_distr(struct tipc_crypto * tx,u8 key,struct tipc_node * dest)2191 int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key,
2192 struct tipc_node *dest)
2193 {
2194 struct tipc_aead *aead;
2195 u32 dnode = tipc_node_get_addr(dest);
2196 int rc = -ENOKEY;
2197
2198 if (!sysctl_tipc_key_exchange_enabled)
2199 return 0;
2200
2201 if (key) {
2202 rcu_read_lock();
2203 aead = tipc_aead_get(tx->aead[key]);
2204 if (likely(aead)) {
2205 rc = tipc_crypto_key_xmit(tx->net, aead->key,
2206 aead->gen, aead->mode,
2207 dnode);
2208 tipc_aead_put(aead);
2209 }
2210 rcu_read_unlock();
2211 }
2212
2213 return rc;
2214 }
2215
2216 /**
2217 * tipc_crypto_key_xmit - Send a session key
2218 * @net: the struct net
2219 * @skey: the session key to be sent
2220 * @gen: the key's generation
2221 * @mode: the key's mode
2222 * @dnode: the destination node address, = 0 if broadcasting to all nodes
2223 *
2224 * The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG'
2225 * as its data section, then xmit-ed through the uc/bc link.
2226 *
2227 * Return: 0 in case of success, otherwise < 0
2228 */
tipc_crypto_key_xmit(struct net * net,struct tipc_aead_key * skey,u16 gen,u8 mode,u32 dnode)2229 static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
2230 u16 gen, u8 mode, u32 dnode)
2231 {
2232 struct sk_buff_head pkts;
2233 struct tipc_msg *hdr;
2234 struct sk_buff *skb;
2235 u16 size, cong_link_cnt;
2236 u8 *data;
2237 int rc;
2238
2239 size = tipc_aead_key_size(skey);
2240 skb = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
2241 if (!skb)
2242 return -ENOMEM;
2243
2244 hdr = buf_msg(skb);
2245 tipc_msg_init(tipc_own_addr(net), hdr, MSG_CRYPTO, KEY_DISTR_MSG,
2246 INT_H_SIZE, dnode);
2247 msg_set_size(hdr, INT_H_SIZE + size);
2248 msg_set_key_gen(hdr, gen);
2249 msg_set_key_mode(hdr, mode);
2250
2251 data = msg_data(hdr);
2252 *((__be32 *)(data + TIPC_AEAD_ALG_NAME)) = htonl(skey->keylen);
2253 memcpy(data, skey->alg_name, TIPC_AEAD_ALG_NAME);
2254 memcpy(data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->key,
2255 skey->keylen);
2256
2257 __skb_queue_head_init(&pkts);
2258 __skb_queue_tail(&pkts, skb);
2259 if (dnode)
2260 rc = tipc_node_xmit(net, &pkts, dnode, 0);
2261 else
2262 rc = tipc_bcast_xmit(net, &pkts, &cong_link_cnt);
2263
2264 return rc;
2265 }
2266
2267 /**
2268 * tipc_crypto_key_rcv - Receive a session key
2269 * @rx: the RX crypto
2270 * @hdr: the TIPC v2 message incl. the receiving session key in its data
2271 *
2272 * This function retrieves the session key in the message from peer, then
2273 * schedules a RX work to attach the key to the corresponding RX crypto.
2274 *
2275 * Return: "true" if the key has been scheduled for attaching, otherwise
2276 * "false".
2277 */
tipc_crypto_key_rcv(struct tipc_crypto * rx,struct tipc_msg * hdr)2278 static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr)
2279 {
2280 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
2281 struct tipc_aead_key *skey = NULL;
2282 u16 key_gen = msg_key_gen(hdr);
2283 u32 size = msg_data_sz(hdr);
2284 u8 *data = msg_data(hdr);
2285 unsigned int keylen;
2286
2287 /* Verify whether the size can exist in the packet */
2288 if (unlikely(size < sizeof(struct tipc_aead_key) + TIPC_AEAD_KEYLEN_MIN)) {
2289 pr_debug("%s: message data size is too small\n", rx->name);
2290 goto exit;
2291 }
2292
2293 keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME)));
2294
2295 /* Verify the supplied size values */
2296 if (unlikely(size != keylen + sizeof(struct tipc_aead_key) ||
2297 keylen > TIPC_AEAD_KEY_SIZE_MAX)) {
2298 pr_debug("%s: invalid MSG_CRYPTO key size\n", rx->name);
2299 goto exit;
2300 }
2301
2302 spin_lock(&rx->lock);
2303 if (unlikely(rx->skey || (key_gen == rx->key_gen && rx->key.keys))) {
2304 pr_err("%s: key existed <%p>, gen %d vs %d\n", rx->name,
2305 rx->skey, key_gen, rx->key_gen);
2306 goto exit_unlock;
2307 }
2308
2309 /* Allocate memory for the key */
2310 skey = kmalloc(size, GFP_ATOMIC);
2311 if (unlikely(!skey)) {
2312 pr_err("%s: unable to allocate memory for skey\n", rx->name);
2313 goto exit_unlock;
2314 }
2315
2316 /* Copy key from msg data */
2317 skey->keylen = keylen;
2318 memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME);
2319 memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32),
2320 skey->keylen);
2321
2322 rx->key_gen = key_gen;
2323 rx->skey_mode = msg_key_mode(hdr);
2324 rx->skey = skey;
2325 rx->nokey = 0;
2326 mb(); /* for nokey flag */
2327
2328 exit_unlock:
2329 spin_unlock(&rx->lock);
2330
2331 exit:
2332 /* Schedule the key attaching on this crypto */
2333 if (likely(skey && queue_delayed_work(tx->wq, &rx->work, 0)))
2334 return true;
2335
2336 return false;
2337 }
2338
2339 /**
2340 * tipc_crypto_work_rx - Scheduled RX works handler
2341 * @work: the struct RX work
2342 *
2343 * The function processes the previous scheduled works i.e. distributing TX key
2344 * or attaching a received session key on RX crypto.
2345 */
tipc_crypto_work_rx(struct work_struct * work)2346 static void tipc_crypto_work_rx(struct work_struct *work)
2347 {
2348 struct delayed_work *dwork = to_delayed_work(work);
2349 struct tipc_crypto *rx = container_of(dwork, struct tipc_crypto, work);
2350 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
2351 unsigned long delay = msecs_to_jiffies(5000);
2352 bool resched = false;
2353 u8 key;
2354 int rc;
2355
2356 /* Case 1: Distribute TX key to peer if scheduled */
2357 if (atomic_cmpxchg(&rx->key_distr,
2358 KEY_DISTR_SCHED,
2359 KEY_DISTR_COMPL) == KEY_DISTR_SCHED) {
2360 /* Always pick the newest one for distributing */
2361 key = tx->key.pending ?: tx->key.active;
2362 rc = tipc_crypto_key_distr(tx, key, rx->node);
2363 if (unlikely(rc))
2364 pr_warn("%s: unable to distr key[%d] to %s, err %d\n",
2365 tx->name, key, tipc_node_get_id_str(rx->node),
2366 rc);
2367
2368 /* Sched for key_distr releasing */
2369 resched = true;
2370 } else {
2371 atomic_cmpxchg(&rx->key_distr, KEY_DISTR_COMPL, 0);
2372 }
2373
2374 /* Case 2: Attach a pending received session key from peer if any */
2375 if (rx->skey) {
2376 rc = tipc_crypto_key_init(rx, rx->skey, rx->skey_mode, false);
2377 if (unlikely(rc < 0))
2378 pr_warn("%s: unable to attach received skey, err %d\n",
2379 rx->name, rc);
2380 switch (rc) {
2381 case -EBUSY:
2382 case -ENOMEM:
2383 /* Resched the key attaching */
2384 resched = true;
2385 break;
2386 default:
2387 synchronize_rcu();
2388 kfree(rx->skey);
2389 rx->skey = NULL;
2390 break;
2391 }
2392 }
2393
2394 if (resched && queue_delayed_work(tx->wq, &rx->work, delay))
2395 return;
2396
2397 tipc_node_put(rx->node);
2398 }
2399
2400 /**
2401 * tipc_crypto_rekeying_sched - (Re)schedule rekeying w/o new interval
2402 * @tx: TX crypto
2403 * @changed: if the rekeying needs to be rescheduled with new interval
2404 * @new_intv: new rekeying interval (when "changed" = true)
2405 */
tipc_crypto_rekeying_sched(struct tipc_crypto * tx,bool changed,u32 new_intv)2406 void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed,
2407 u32 new_intv)
2408 {
2409 unsigned long delay;
2410 bool now = false;
2411
2412 if (changed) {
2413 if (new_intv == TIPC_REKEYING_NOW)
2414 now = true;
2415 else
2416 tx->rekeying_intv = new_intv;
2417 cancel_delayed_work_sync(&tx->work);
2418 }
2419
2420 if (tx->rekeying_intv || now) {
2421 delay = (now) ? 0 : tx->rekeying_intv * 60 * 1000;
2422 queue_delayed_work(tx->wq, &tx->work, msecs_to_jiffies(delay));
2423 }
2424 }
2425
2426 /**
2427 * tipc_crypto_work_tx - Scheduled TX works handler
2428 * @work: the struct TX work
2429 *
2430 * The function processes the previous scheduled work, i.e. key rekeying, by
2431 * generating a new session key based on current one, then attaching it to the
2432 * TX crypto and finally distributing it to peers. It also re-schedules the
2433 * rekeying if needed.
2434 */
tipc_crypto_work_tx(struct work_struct * work)2435 static void tipc_crypto_work_tx(struct work_struct *work)
2436 {
2437 struct delayed_work *dwork = to_delayed_work(work);
2438 struct tipc_crypto *tx = container_of(dwork, struct tipc_crypto, work);
2439 struct tipc_aead_key *skey = NULL;
2440 struct tipc_key key = tx->key;
2441 struct tipc_aead *aead;
2442 int rc = -ENOMEM;
2443
2444 if (unlikely(key.pending))
2445 goto resched;
2446
2447 /* Take current key as a template */
2448 rcu_read_lock();
2449 aead = rcu_dereference(tx->aead[key.active ?: KEY_MASTER]);
2450 if (unlikely(!aead)) {
2451 rcu_read_unlock();
2452 /* At least one key should exist for securing */
2453 return;
2454 }
2455
2456 /* Lets duplicate it first */
2457 skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_ATOMIC);
2458 rcu_read_unlock();
2459
2460 /* Now, generate new key, initiate & distribute it */
2461 if (likely(skey)) {
2462 rc = tipc_aead_key_generate(skey) ?:
2463 tipc_crypto_key_init(tx, skey, PER_NODE_KEY, false);
2464 if (likely(rc > 0))
2465 rc = tipc_crypto_key_distr(tx, rc, NULL);
2466 kfree_sensitive(skey);
2467 }
2468
2469 if (unlikely(rc))
2470 pr_warn_ratelimited("%s: rekeying returns %d\n", tx->name, rc);
2471
2472 resched:
2473 /* Re-schedule rekeying if any */
2474 tipc_crypto_rekeying_sched(tx, false, 0);
2475 }
2476