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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 */
57enum {
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 */
69enum {
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 */
84static const char *hstats[MAX_STATS] = {"ok", "nok", "async", "async_ok",
85 "async_nok", "badmsgs", "nokeys",
86 "switches"};
87
88/* Max TFMs number per key */
89int sysctl_tipc_max_tfms __read_mostly = TIPC_MAX_TFMS_DEF;
90/* Key exchange switch, default: on */
91int 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 */
101struct 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 */
129struct 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 */
150struct 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 */
173struct 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 */
203struct 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 */
239struct 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 */
246struct tipc_crypto_rx_ctx {
247 struct tipc_aead *aead;
248 struct tipc_bearer *bearer;
249};
250
251static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead);
252static inline void tipc_aead_put(struct tipc_aead *aead);
253static void tipc_aead_free(struct rcu_head *rp);
254static int tipc_aead_users(struct tipc_aead __rcu *aead);
255static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim);
256static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim);
257static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val);
258static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead);
259static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
260 u8 mode);
261static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src);
262static 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);
266static 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);
270static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err);
271static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
272 struct sk_buff *skb, struct tipc_bearer *b);
273static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err);
274static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr);
275static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
276 u8 tx_key, struct sk_buff *skb,
277 struct tipc_crypto *__rx);
278static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
279 u8 new_passive,
280 u8 new_active,
281 u8 new_pending);
282static int tipc_crypto_key_attach(struct tipc_crypto *c,
283 struct tipc_aead *aead, u8 pos,
284 bool master_key);
285static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending);
286static 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);
290static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb);
291static int tipc_crypto_key_revoke(struct net *net, u8 tx_key);
292static 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);
296static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
297 struct tipc_bearer *b,
298 struct sk_buff **skb, int err);
299static void tipc_crypto_do_cmd(struct net *net, int cmd);
300static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf);
301static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
302 char *buf);
303static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
304 u16 gen, u8 mode, u32 dnode);
305static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr);
306static void tipc_crypto_work_tx(struct work_struct *work);
307static void tipc_crypto_work_rx(struct work_struct *work);
308static 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) \
319do { \
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 */
334int 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 */
368static 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
383static 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
396static 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 */
406static 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
431static 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
445static 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
456static 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
467static 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 */
488static 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 */
514static 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 memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
601 atomic_set(&tmp->users, 0);
602 atomic64_set(&tmp->seqno, 0);
603 refcount_set(&tmp->refcnt, 1);
604
605 *aead = tmp;
606 return 0;
607}
608
609/**
610 * tipc_aead_clone - Clone a TIPC AEAD key
611 * @dst: dest key for the cloning
612 * @src: source key to clone from
613 *
614 * Make a "copy" of the source AEAD key data to the dest, the TFMs list is
615 * common for the keys.
616 * A reference to the source is hold in the "cloned" pointer for the later
617 * freeing purposes.
618 *
619 * Note: this must be done in cluster-key mode only!
620 * Return: 0 in case of success, otherwise < 0
621 */
622static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src)
623{
624 struct tipc_aead *aead;
625 int cpu;
626
627 if (!src)
628 return -ENOKEY;
629
630 if (src->mode != CLUSTER_KEY)
631 return -EINVAL;
632
633 if (unlikely(*dst))
634 return -EEXIST;
635
636 aead = kzalloc(sizeof(*aead), GFP_ATOMIC);
637 if (unlikely(!aead))
638 return -ENOMEM;
639
640 aead->tfm_entry = alloc_percpu_gfp(struct tipc_tfm *, GFP_ATOMIC);
641 if (unlikely(!aead->tfm_entry)) {
642 kfree_sensitive(aead);
643 return -ENOMEM;
644 }
645
646 for_each_possible_cpu(cpu) {
647 *per_cpu_ptr(aead->tfm_entry, cpu) =
648 *per_cpu_ptr(src->tfm_entry, cpu);
649 }
650
651 memcpy(aead->hint, src->hint, sizeof(src->hint));
652 aead->mode = src->mode;
653 aead->salt = src->salt;
654 aead->authsize = src->authsize;
655 atomic_set(&aead->users, 0);
656 atomic64_set(&aead->seqno, 0);
657 refcount_set(&aead->refcnt, 1);
658
659 WARN_ON(!refcount_inc_not_zero(&src->refcnt));
660 aead->cloned = src;
661
662 *dst = aead;
663 return 0;
664}
665
666/**
667 * tipc_aead_mem_alloc - Allocate memory for AEAD request operations
668 * @tfm: cipher handle to be registered with the request
669 * @crypto_ctx_size: size of crypto context for callback
670 * @iv: returned pointer to IV data
671 * @req: returned pointer to AEAD request data
672 * @sg: returned pointer to SG lists
673 * @nsg: number of SG lists to be allocated
674 *
675 * Allocate memory to store the crypto context data, AEAD request, IV and SG
676 * lists, the memory layout is as follows:
677 * crypto_ctx || iv || aead_req || sg[]
678 *
679 * Return: the pointer to the memory areas in case of success, otherwise NULL
680 */
681static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
682 unsigned int crypto_ctx_size,
683 u8 **iv, struct aead_request **req,
684 struct scatterlist **sg, int nsg)
685{
686 unsigned int iv_size, req_size;
687 unsigned int len;
688 u8 *mem;
689
690 iv_size = crypto_aead_ivsize(tfm);
691 req_size = sizeof(**req) + crypto_aead_reqsize(tfm);
692
693 len = crypto_ctx_size;
694 len += iv_size;
695 len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1);
696 len = ALIGN(len, crypto_tfm_ctx_alignment());
697 len += req_size;
698 len = ALIGN(len, __alignof__(struct scatterlist));
699 len += nsg * sizeof(**sg);
700
701 mem = kmalloc(len, GFP_ATOMIC);
702 if (!mem)
703 return NULL;
704
705 *iv = (u8 *)PTR_ALIGN(mem + crypto_ctx_size,
706 crypto_aead_alignmask(tfm) + 1);
707 *req = (struct aead_request *)PTR_ALIGN(*iv + iv_size,
708 crypto_tfm_ctx_alignment());
709 *sg = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
710 __alignof__(struct scatterlist));
711
712 return (void *)mem;
713}
714
715/**
716 * tipc_aead_encrypt - Encrypt a message
717 * @aead: TIPC AEAD key for the message encryption
718 * @skb: the input/output skb
719 * @b: TIPC bearer where the message will be delivered after the encryption
720 * @dst: the destination media address
721 * @__dnode: TIPC dest node if "known"
722 *
723 * Return:
724 * * 0 : if the encryption has completed
725 * * -EINPROGRESS/-EBUSY : if a callback will be performed
726 * * < 0 : the encryption has failed
727 */
728static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
729 struct tipc_bearer *b,
730 struct tipc_media_addr *dst,
731 struct tipc_node *__dnode)
732{
733 struct crypto_aead *tfm = tipc_aead_tfm_next(aead);
734 struct tipc_crypto_tx_ctx *tx_ctx;
735 struct aead_request *req;
736 struct sk_buff *trailer;
737 struct scatterlist *sg;
738 struct tipc_ehdr *ehdr;
739 int ehsz, len, tailen, nsg, rc;
740 void *ctx;
741 u32 salt;
742 u8 *iv;
743
744 /* Make sure message len at least 4-byte aligned */
745 len = ALIGN(skb->len, 4);
746 tailen = len - skb->len + aead->authsize;
747
748 /* Expand skb tail for authentication tag:
749 * As for simplicity, we'd have made sure skb having enough tailroom
750 * for authentication tag @skb allocation. Even when skb is nonlinear
751 * but there is no frag_list, it should be still fine!
752 * Otherwise, we must cow it to be a writable buffer with the tailroom.
753 */
754 SKB_LINEAR_ASSERT(skb);
755 if (tailen > skb_tailroom(skb)) {
756 pr_debug("TX(): skb tailroom is not enough: %d, requires: %d\n",
757 skb_tailroom(skb), tailen);
758 }
759
760 if (unlikely(!skb_cloned(skb) && tailen <= skb_tailroom(skb))) {
761 nsg = 1;
762 trailer = skb;
763 } else {
764 /* TODO: We could avoid skb_cow_data() if skb has no frag_list
765 * e.g. by skb_fill_page_desc() to add another page to the skb
766 * with the wanted tailen... However, page skbs look not often,
767 * so take it easy now!
768 * Cloned skbs e.g. from link_xmit() seems no choice though :(
769 */
770 nsg = skb_cow_data(skb, tailen, &trailer);
771 if (unlikely(nsg < 0)) {
772 pr_err("TX: skb_cow_data() returned %d\n", nsg);
773 return nsg;
774 }
775 }
776
777 pskb_put(skb, trailer, tailen);
778
779 /* Allocate memory for the AEAD operation */
780 ctx = tipc_aead_mem_alloc(tfm, sizeof(*tx_ctx), &iv, &req, &sg, nsg);
781 if (unlikely(!ctx))
782 return -ENOMEM;
783 TIPC_SKB_CB(skb)->crypto_ctx = ctx;
784
785 /* Map skb to the sg lists */
786 sg_init_table(sg, nsg);
787 rc = skb_to_sgvec(skb, sg, 0, skb->len);
788 if (unlikely(rc < 0)) {
789 pr_err("TX: skb_to_sgvec() returned %d, nsg %d!\n", rc, nsg);
790 goto exit;
791 }
792
793 /* Prepare IV: [SALT (4 octets)][SEQNO (8 octets)]
794 * In case we're in cluster-key mode, SALT is varied by xor-ing with
795 * the source address (or w0 of id), otherwise with the dest address
796 * if dest is known.
797 */
798 ehdr = (struct tipc_ehdr *)skb->data;
799 salt = aead->salt;
800 if (aead->mode == CLUSTER_KEY)
801 salt ^= __be32_to_cpu(ehdr->addr);
802 else if (__dnode)
803 salt ^= tipc_node_get_addr(__dnode);
804 memcpy(iv, &salt, 4);
805 memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
806
807 /* Prepare request */
808 ehsz = tipc_ehdr_size(ehdr);
809 aead_request_set_tfm(req, tfm);
810 aead_request_set_ad(req, ehsz);
811 aead_request_set_crypt(req, sg, sg, len - ehsz, iv);
812
813 /* Set callback function & data */
814 aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
815 tipc_aead_encrypt_done, skb);
816 tx_ctx = (struct tipc_crypto_tx_ctx *)ctx;
817 tx_ctx->aead = aead;
818 tx_ctx->bearer = b;
819 memcpy(&tx_ctx->dst, dst, sizeof(*dst));
820
821 /* Hold bearer */
822 if (unlikely(!tipc_bearer_hold(b))) {
823 rc = -ENODEV;
824 goto exit;
825 }
826
827 /* Now, do encrypt */
828 rc = crypto_aead_encrypt(req);
829 if (rc == -EINPROGRESS || rc == -EBUSY)
830 return rc;
831
832 tipc_bearer_put(b);
833
834exit:
835 kfree(ctx);
836 TIPC_SKB_CB(skb)->crypto_ctx = NULL;
837 return rc;
838}
839
840static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err)
841{
842 struct sk_buff *skb = base->data;
843 struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
844 struct tipc_bearer *b = tx_ctx->bearer;
845 struct tipc_aead *aead = tx_ctx->aead;
846 struct tipc_crypto *tx = aead->crypto;
847 struct net *net = tx->net;
848
849 switch (err) {
850 case 0:
851 this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]);
852 rcu_read_lock();
853 if (likely(test_bit(0, &b->up)))
854 b->media->send_msg(net, skb, b, &tx_ctx->dst);
855 else
856 kfree_skb(skb);
857 rcu_read_unlock();
858 break;
859 case -EINPROGRESS:
860 return;
861 default:
862 this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]);
863 kfree_skb(skb);
864 break;
865 }
866
867 kfree(tx_ctx);
868 tipc_bearer_put(b);
869 tipc_aead_put(aead);
870}
871
872/**
873 * tipc_aead_decrypt - Decrypt an encrypted message
874 * @net: struct net
875 * @aead: TIPC AEAD for the message decryption
876 * @skb: the input/output skb
877 * @b: TIPC bearer where the message has been received
878 *
879 * Return:
880 * * 0 : if the decryption has completed
881 * * -EINPROGRESS/-EBUSY : if a callback will be performed
882 * * < 0 : the decryption has failed
883 */
884static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
885 struct sk_buff *skb, struct tipc_bearer *b)
886{
887 struct tipc_crypto_rx_ctx *rx_ctx;
888 struct aead_request *req;
889 struct crypto_aead *tfm;
890 struct sk_buff *unused;
891 struct scatterlist *sg;
892 struct tipc_ehdr *ehdr;
893 int ehsz, nsg, rc;
894 void *ctx;
895 u32 salt;
896 u8 *iv;
897
898 if (unlikely(!aead))
899 return -ENOKEY;
900
901 nsg = skb_cow_data(skb, 0, &unused);
902 if (unlikely(nsg < 0)) {
903 pr_err("RX: skb_cow_data() returned %d\n", nsg);
904 return nsg;
905 }
906
907 /* Allocate memory for the AEAD operation */
908 tfm = tipc_aead_tfm_next(aead);
909 ctx = tipc_aead_mem_alloc(tfm, sizeof(*rx_ctx), &iv, &req, &sg, nsg);
910 if (unlikely(!ctx))
911 return -ENOMEM;
912 TIPC_SKB_CB(skb)->crypto_ctx = ctx;
913
914 /* Map skb to the sg lists */
915 sg_init_table(sg, nsg);
916 rc = skb_to_sgvec(skb, sg, 0, skb->len);
917 if (unlikely(rc < 0)) {
918 pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg);
919 goto exit;
920 }
921
922 /* Reconstruct IV: */
923 ehdr = (struct tipc_ehdr *)skb->data;
924 salt = aead->salt;
925 if (aead->mode == CLUSTER_KEY)
926 salt ^= __be32_to_cpu(ehdr->addr);
927 else if (ehdr->destined)
928 salt ^= tipc_own_addr(net);
929 memcpy(iv, &salt, 4);
930 memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
931
932 /* Prepare request */
933 ehsz = tipc_ehdr_size(ehdr);
934 aead_request_set_tfm(req, tfm);
935 aead_request_set_ad(req, ehsz);
936 aead_request_set_crypt(req, sg, sg, skb->len - ehsz, iv);
937
938 /* Set callback function & data */
939 aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
940 tipc_aead_decrypt_done, skb);
941 rx_ctx = (struct tipc_crypto_rx_ctx *)ctx;
942 rx_ctx->aead = aead;
943 rx_ctx->bearer = b;
944
945 /* Hold bearer */
946 if (unlikely(!tipc_bearer_hold(b))) {
947 rc = -ENODEV;
948 goto exit;
949 }
950
951 /* Now, do decrypt */
952 rc = crypto_aead_decrypt(req);
953 if (rc == -EINPROGRESS || rc == -EBUSY)
954 return rc;
955
956 tipc_bearer_put(b);
957
958exit:
959 kfree(ctx);
960 TIPC_SKB_CB(skb)->crypto_ctx = NULL;
961 return rc;
962}
963
964static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err)
965{
966 struct sk_buff *skb = base->data;
967 struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
968 struct tipc_bearer *b = rx_ctx->bearer;
969 struct tipc_aead *aead = rx_ctx->aead;
970 struct tipc_crypto_stats __percpu *stats = aead->crypto->stats;
971 struct net *net = aead->crypto->net;
972
973 switch (err) {
974 case 0:
975 this_cpu_inc(stats->stat[STAT_ASYNC_OK]);
976 break;
977 case -EINPROGRESS:
978 return;
979 default:
980 this_cpu_inc(stats->stat[STAT_ASYNC_NOK]);
981 break;
982 }
983
984 kfree(rx_ctx);
985 tipc_crypto_rcv_complete(net, aead, b, &skb, err);
986 if (likely(skb)) {
987 if (likely(test_bit(0, &b->up)))
988 tipc_rcv(net, skb, b);
989 else
990 kfree_skb(skb);
991 }
992
993 tipc_bearer_put(b);
994}
995
996static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr)
997{
998 return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
999}
1000
1001/**
1002 * tipc_ehdr_validate - Validate an encryption message
1003 * @skb: the message buffer
1004 *
1005 * Return: "true" if this is a valid encryption message, otherwise "false"
1006 */
1007bool tipc_ehdr_validate(struct sk_buff *skb)
1008{
1009 struct tipc_ehdr *ehdr;
1010 int ehsz;
1011
1012 if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE)))
1013 return false;
1014
1015 ehdr = (struct tipc_ehdr *)skb->data;
1016 if (unlikely(ehdr->version != TIPC_EVERSION))
1017 return false;
1018 ehsz = tipc_ehdr_size(ehdr);
1019 if (unlikely(!pskb_may_pull(skb, ehsz)))
1020 return false;
1021 if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE))
1022 return false;
1023
1024 return true;
1025}
1026
1027/**
1028 * tipc_ehdr_build - Build TIPC encryption message header
1029 * @net: struct net
1030 * @aead: TX AEAD key to be used for the message encryption
1031 * @tx_key: key id used for the message encryption
1032 * @skb: input/output message skb
1033 * @__rx: RX crypto handle if dest is "known"
1034 *
1035 * Return: the header size if the building is successful, otherwise < 0
1036 */
1037static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
1038 u8 tx_key, struct sk_buff *skb,
1039 struct tipc_crypto *__rx)
1040{
1041 struct tipc_msg *hdr = buf_msg(skb);
1042 struct tipc_ehdr *ehdr;
1043 u32 user = msg_user(hdr);
1044 u64 seqno;
1045 int ehsz;
1046
1047 /* Make room for encryption header */
1048 ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
1049 WARN_ON(skb_headroom(skb) < ehsz);
1050 ehdr = (struct tipc_ehdr *)skb_push(skb, ehsz);
1051
1052 /* Obtain a seqno first:
1053 * Use the key seqno (= cluster wise) if dest is unknown or we're in
1054 * cluster key mode, otherwise it's better for a per-peer seqno!
1055 */
1056 if (!__rx || aead->mode == CLUSTER_KEY)
1057 seqno = atomic64_inc_return(&aead->seqno);
1058 else
1059 seqno = atomic64_inc_return(&__rx->sndnxt);
1060
1061 /* Revoke the key if seqno is wrapped around */
1062 if (unlikely(!seqno))
1063 return tipc_crypto_key_revoke(net, tx_key);
1064
1065 /* Word 1-2 */
1066 ehdr->seqno = cpu_to_be64(seqno);
1067
1068 /* Words 0, 3- */
1069 ehdr->version = TIPC_EVERSION;
1070 ehdr->user = 0;
1071 ehdr->keepalive = 0;
1072 ehdr->tx_key = tx_key;
1073 ehdr->destined = (__rx) ? 1 : 0;
1074 ehdr->rx_key_active = (__rx) ? __rx->key.active : 0;
1075 ehdr->rx_nokey = (__rx) ? __rx->nokey : 0;
1076 ehdr->master_key = aead->crypto->key_master;
1077 ehdr->reserved_1 = 0;
1078 ehdr->reserved_2 = 0;
1079
1080 switch (user) {
1081 case LINK_CONFIG:
1082 ehdr->user = LINK_CONFIG;
1083 memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN);
1084 break;
1085 default:
1086 if (user == LINK_PROTOCOL && msg_type(hdr) == STATE_MSG) {
1087 ehdr->user = LINK_PROTOCOL;
1088 ehdr->keepalive = msg_is_keepalive(hdr);
1089 }
1090 ehdr->addr = hdr->hdr[3];
1091 break;
1092 }
1093
1094 return ehsz;
1095}
1096
1097static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
1098 u8 new_passive,
1099 u8 new_active,
1100 u8 new_pending)
1101{
1102 struct tipc_key old = c->key;
1103 char buf[32];
1104
1105 c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) |
1106 ((new_active & KEY_MASK) << (KEY_BITS)) |
1107 ((new_pending & KEY_MASK));
1108
1109 pr_debug("%s: key changing %s ::%pS\n", c->name,
1110 tipc_key_change_dump(old, c->key, buf),
1111 __builtin_return_address(0));
1112}
1113
1114/**
1115 * tipc_crypto_key_init - Initiate a new user / AEAD key
1116 * @c: TIPC crypto to which new key is attached
1117 * @ukey: the user key
1118 * @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY)
1119 * @master_key: specify this is a cluster master key
1120 *
1121 * A new TIPC AEAD key will be allocated and initiated with the specified user
1122 * key, then attached to the TIPC crypto.
1123 *
1124 * Return: new key id in case of success, otherwise: < 0
1125 */
1126int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
1127 u8 mode, bool master_key)
1128{
1129 struct tipc_aead *aead = NULL;
1130 int rc = 0;
1131
1132 /* Initiate with the new user key */
1133 rc = tipc_aead_init(&aead, ukey, mode);
1134
1135 /* Attach it to the crypto */
1136 if (likely(!rc)) {
1137 rc = tipc_crypto_key_attach(c, aead, 0, master_key);
1138 if (rc < 0)
1139 tipc_aead_free(&aead->rcu);
1140 }
1141
1142 return rc;
1143}
1144
1145/**
1146 * tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto
1147 * @c: TIPC crypto to which the new AEAD key is attached
1148 * @aead: the new AEAD key pointer
1149 * @pos: desired slot in the crypto key array, = 0 if any!
1150 * @master_key: specify this is a cluster master key
1151 *
1152 * Return: new key id in case of success, otherwise: -EBUSY
1153 */
1154static int tipc_crypto_key_attach(struct tipc_crypto *c,
1155 struct tipc_aead *aead, u8 pos,
1156 bool master_key)
1157{
1158 struct tipc_key key;
1159 int rc = -EBUSY;
1160 u8 new_key;
1161
1162 spin_lock_bh(&c->lock);
1163 key = c->key;
1164 if (master_key) {
1165 new_key = KEY_MASTER;
1166 goto attach;
1167 }
1168 if (key.active && key.passive)
1169 goto exit;
1170 if (key.pending) {
1171 if (tipc_aead_users(c->aead[key.pending]) > 0)
1172 goto exit;
1173 /* if (pos): ok with replacing, will be aligned when needed */
1174 /* Replace it */
1175 new_key = key.pending;
1176 } else {
1177 if (pos) {
1178 if (key.active && pos != key_next(key.active)) {
1179 key.passive = pos;
1180 new_key = pos;
1181 goto attach;
1182 } else if (!key.active && !key.passive) {
1183 key.pending = pos;
1184 new_key = pos;
1185 goto attach;
1186 }
1187 }
1188 key.pending = key_next(key.active ?: key.passive);
1189 new_key = key.pending;
1190 }
1191
1192attach:
1193 aead->crypto = c;
1194 aead->gen = (is_tx(c)) ? ++c->key_gen : c->key_gen;
1195 tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock);
1196 if (likely(c->key.keys != key.keys))
1197 tipc_crypto_key_set_state(c, key.passive, key.active,
1198 key.pending);
1199 c->working = 1;
1200 c->nokey = 0;
1201 c->key_master |= master_key;
1202 rc = new_key;
1203
1204exit:
1205 spin_unlock_bh(&c->lock);
1206 return rc;
1207}
1208
1209void tipc_crypto_key_flush(struct tipc_crypto *c)
1210{
1211 struct tipc_crypto *tx, *rx;
1212 int k;
1213
1214 spin_lock_bh(&c->lock);
1215 if (is_rx(c)) {
1216 /* Try to cancel pending work */
1217 rx = c;
1218 tx = tipc_net(rx->net)->crypto_tx;
1219 if (cancel_delayed_work(&rx->work)) {
1220 kfree(rx->skey);
1221 rx->skey = NULL;
1222 atomic_xchg(&rx->key_distr, 0);
1223 tipc_node_put(rx->node);
1224 }
1225 /* RX stopping => decrease TX key users if any */
1226 k = atomic_xchg(&rx->peer_rx_active, 0);
1227 if (k) {
1228 tipc_aead_users_dec(tx->aead[k], 0);
1229 /* Mark the point TX key users changed */
1230 tx->timer1 = jiffies;
1231 }
1232 }
1233
1234 c->flags = 0;
1235 tipc_crypto_key_set_state(c, 0, 0, 0);
1236 for (k = KEY_MIN; k <= KEY_MAX; k++)
1237 tipc_crypto_key_detach(c->aead[k], &c->lock);
1238 atomic64_set(&c->sndnxt, 0);
1239 spin_unlock_bh(&c->lock);
1240}
1241
1242/**
1243 * tipc_crypto_key_try_align - Align RX keys if possible
1244 * @rx: RX crypto handle
1245 * @new_pending: new pending slot if aligned (= TX key from peer)
1246 *
1247 * Peer has used an unknown key slot, this only happens when peer has left and
1248 * rejoned, or we are newcomer.
1249 * That means, there must be no active key but a pending key at unaligned slot.
1250 * If so, we try to move the pending key to the new slot.
1251 * Note: A potential passive key can exist, it will be shifted correspondingly!
1252 *
1253 * Return: "true" if key is successfully aligned, otherwise "false"
1254 */
1255static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
1256{
1257 struct tipc_aead *tmp1, *tmp2 = NULL;
1258 struct tipc_key key;
1259 bool aligned = false;
1260 u8 new_passive = 0;
1261 int x;
1262
1263 spin_lock(&rx->lock);
1264 key = rx->key;
1265 if (key.pending == new_pending) {
1266 aligned = true;
1267 goto exit;
1268 }
1269 if (key.active)
1270 goto exit;
1271 if (!key.pending)
1272 goto exit;
1273 if (tipc_aead_users(rx->aead[key.pending]) > 0)
1274 goto exit;
1275
1276 /* Try to "isolate" this pending key first */
1277 tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock);
1278 if (!refcount_dec_if_one(&tmp1->refcnt))
1279 goto exit;
1280 rcu_assign_pointer(rx->aead[key.pending], NULL);
1281
1282 /* Move passive key if any */
1283 if (key.passive) {
1284 tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock));
1285 x = (key.passive - key.pending + new_pending) % KEY_MAX;
1286 new_passive = (x <= 0) ? x + KEY_MAX : x;
1287 }
1288
1289 /* Re-allocate the key(s) */
1290 tipc_crypto_key_set_state(rx, new_passive, 0, new_pending);
1291 rcu_assign_pointer(rx->aead[new_pending], tmp1);
1292 if (new_passive)
1293 rcu_assign_pointer(rx->aead[new_passive], tmp2);
1294 refcount_set(&tmp1->refcnt, 1);
1295 aligned = true;
1296 pr_info_ratelimited("%s: key[%d] -> key[%d]\n", rx->name, key.pending,
1297 new_pending);
1298
1299exit:
1300 spin_unlock(&rx->lock);
1301 return aligned;
1302}
1303
1304/**
1305 * tipc_crypto_key_pick_tx - Pick one TX key for message decryption
1306 * @tx: TX crypto handle
1307 * @rx: RX crypto handle (can be NULL)
1308 * @skb: the message skb which will be decrypted later
1309 * @tx_key: peer TX key id
1310 *
1311 * This function looks up the existing TX keys and pick one which is suitable
1312 * for the message decryption, that must be a cluster key and not used before
1313 * on the same message (i.e. recursive).
1314 *
1315 * Return: the TX AEAD key handle in case of success, otherwise NULL
1316 */
1317static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
1318 struct tipc_crypto *rx,
1319 struct sk_buff *skb,
1320 u8 tx_key)
1321{
1322 struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb);
1323 struct tipc_aead *aead = NULL;
1324 struct tipc_key key = tx->key;
1325 u8 k, i = 0;
1326
1327 /* Initialize data if not yet */
1328 if (!skb_cb->tx_clone_deferred) {
1329 skb_cb->tx_clone_deferred = 1;
1330 memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1331 }
1332
1333 skb_cb->tx_clone_ctx.rx = rx;
1334 if (++skb_cb->tx_clone_ctx.recurs > 2)
1335 return NULL;
1336
1337 /* Pick one TX key */
1338 spin_lock(&tx->lock);
1339 if (tx_key == KEY_MASTER) {
1340 aead = tipc_aead_rcu_ptr(tx->aead[KEY_MASTER], &tx->lock);
1341 goto done;
1342 }
1343 do {
1344 k = (i == 0) ? key.pending :
1345 ((i == 1) ? key.active : key.passive);
1346 if (!k)
1347 continue;
1348 aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock);
1349 if (!aead)
1350 continue;
1351 if (aead->mode != CLUSTER_KEY ||
1352 aead == skb_cb->tx_clone_ctx.last) {
1353 aead = NULL;
1354 continue;
1355 }
1356 /* Ok, found one cluster key */
1357 skb_cb->tx_clone_ctx.last = aead;
1358 WARN_ON(skb->next);
1359 skb->next = skb_clone(skb, GFP_ATOMIC);
1360 if (unlikely(!skb->next))
1361 pr_warn("Failed to clone skb for next round if any\n");
1362 break;
1363 } while (++i < 3);
1364
1365done:
1366 if (likely(aead))
1367 WARN_ON(!refcount_inc_not_zero(&aead->refcnt));
1368 spin_unlock(&tx->lock);
1369
1370 return aead;
1371}
1372
1373/**
1374 * tipc_crypto_key_synch: Synch own key data according to peer key status
1375 * @rx: RX crypto handle
1376 * @skb: TIPCv2 message buffer (incl. the ehdr from peer)
1377 *
1378 * This function updates the peer node related data as the peer RX active key
1379 * has changed, so the number of TX keys' users on this node are increased and
1380 * decreased correspondingly.
1381 *
1382 * It also considers if peer has no key, then we need to make own master key
1383 * (if any) taking over i.e. starting grace period and also trigger key
1384 * distributing process.
1385 *
1386 * The "per-peer" sndnxt is also reset when the peer key has switched.
1387 */
1388static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb)
1389{
1390 struct tipc_ehdr *ehdr = (struct tipc_ehdr *)skb_network_header(skb);
1391 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
1392 struct tipc_msg *hdr = buf_msg(skb);
1393 u32 self = tipc_own_addr(rx->net);
1394 u8 cur, new;
1395 unsigned long delay;
1396
1397 /* Update RX 'key_master' flag according to peer, also mark "legacy" if
1398 * a peer has no master key.
1399 */
1400 rx->key_master = ehdr->master_key;
1401 if (!rx->key_master)
1402 tx->legacy_user = 1;
1403
1404 /* For later cases, apply only if message is destined to this node */
1405 if (!ehdr->destined || msg_short(hdr) || msg_destnode(hdr) != self)
1406 return;
1407
1408 /* Case 1: Peer has no keys, let's make master key take over */
1409 if (ehdr->rx_nokey) {
1410 /* Set or extend grace period */
1411 tx->timer2 = jiffies;
1412 /* Schedule key distributing for the peer if not yet */
1413 if (tx->key.keys &&
1414 !atomic_cmpxchg(&rx->key_distr, 0, KEY_DISTR_SCHED)) {
1415 get_random_bytes(&delay, 2);
1416 delay %= 5;
1417 delay = msecs_to_jiffies(500 * ++delay);
1418 if (queue_delayed_work(tx->wq, &rx->work, delay))
1419 tipc_node_get(rx->node);
1420 }
1421 } else {
1422 /* Cancel a pending key distributing if any */
1423 atomic_xchg(&rx->key_distr, 0);
1424 }
1425
1426 /* Case 2: Peer RX active key has changed, let's update own TX users */
1427 cur = atomic_read(&rx->peer_rx_active);
1428 new = ehdr->rx_key_active;
1429 if (tx->key.keys &&
1430 cur != new &&
1431 atomic_cmpxchg(&rx->peer_rx_active, cur, new) == cur) {
1432 if (new)
1433 tipc_aead_users_inc(tx->aead[new], INT_MAX);
1434 if (cur)
1435 tipc_aead_users_dec(tx->aead[cur], 0);
1436
1437 atomic64_set(&rx->sndnxt, 0);
1438 /* Mark the point TX key users changed */
1439 tx->timer1 = jiffies;
1440
1441 pr_debug("%s: key users changed %d-- %d++, peer %s\n",
1442 tx->name, cur, new, rx->name);
1443 }
1444}
1445
1446static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
1447{
1448 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1449 struct tipc_key key;
1450
1451 spin_lock(&tx->lock);
1452 key = tx->key;
1453 WARN_ON(!key.active || tx_key != key.active);
1454
1455 /* Free the active key */
1456 tipc_crypto_key_set_state(tx, key.passive, 0, key.pending);
1457 tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1458 spin_unlock(&tx->lock);
1459
1460 pr_warn("%s: key is revoked\n", tx->name);
1461 return -EKEYREVOKED;
1462}
1463
1464int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
1465 struct tipc_node *node)
1466{
1467 struct tipc_crypto *c;
1468
1469 if (*crypto)
1470 return -EEXIST;
1471
1472 /* Allocate crypto */
1473 c = kzalloc(sizeof(*c), GFP_ATOMIC);
1474 if (!c)
1475 return -ENOMEM;
1476
1477 /* Allocate workqueue on TX */
1478 if (!node) {
1479 c->wq = alloc_ordered_workqueue("tipc_crypto", 0);
1480 if (!c->wq) {
1481 kfree(c);
1482 return -ENOMEM;
1483 }
1484 }
1485
1486 /* Allocate statistic structure */
1487 c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
1488 if (!c->stats) {
1489 if (c->wq)
1490 destroy_workqueue(c->wq);
1491 kfree_sensitive(c);
1492 return -ENOMEM;
1493 }
1494
1495 c->flags = 0;
1496 c->net = net;
1497 c->node = node;
1498 get_random_bytes(&c->key_gen, 2);
1499 tipc_crypto_key_set_state(c, 0, 0, 0);
1500 atomic_set(&c->key_distr, 0);
1501 atomic_set(&c->peer_rx_active, 0);
1502 atomic64_set(&c->sndnxt, 0);
1503 c->timer1 = jiffies;
1504 c->timer2 = jiffies;
1505 c->rekeying_intv = TIPC_REKEYING_INTV_DEF;
1506 spin_lock_init(&c->lock);
1507 scnprintf(c->name, 48, "%s(%s)", (is_rx(c)) ? "RX" : "TX",
1508 (is_rx(c)) ? tipc_node_get_id_str(c->node) :
1509 tipc_own_id_string(c->net));
1510
1511 if (is_rx(c))
1512 INIT_DELAYED_WORK(&c->work, tipc_crypto_work_rx);
1513 else
1514 INIT_DELAYED_WORK(&c->work, tipc_crypto_work_tx);
1515
1516 *crypto = c;
1517 return 0;
1518}
1519
1520void tipc_crypto_stop(struct tipc_crypto **crypto)
1521{
1522 struct tipc_crypto *c = *crypto;
1523 u8 k;
1524
1525 if (!c)
1526 return;
1527
1528 /* Flush any queued works & destroy wq */
1529 if (is_tx(c)) {
1530 c->rekeying_intv = 0;
1531 cancel_delayed_work_sync(&c->work);
1532 destroy_workqueue(c->wq);
1533 }
1534
1535 /* Release AEAD keys */
1536 rcu_read_lock();
1537 for (k = KEY_MIN; k <= KEY_MAX; k++)
1538 tipc_aead_put(rcu_dereference(c->aead[k]));
1539 rcu_read_unlock();
1540 pr_debug("%s: has been stopped\n", c->name);
1541
1542 /* Free this crypto statistics */
1543 free_percpu(c->stats);
1544
1545 *crypto = NULL;
1546 kfree_sensitive(c);
1547}
1548
1549void tipc_crypto_timeout(struct tipc_crypto *rx)
1550{
1551 struct tipc_net *tn = tipc_net(rx->net);
1552 struct tipc_crypto *tx = tn->crypto_tx;
1553 struct tipc_key key;
1554 int cmd;
1555
1556 /* TX pending: taking all users & stable -> active */
1557 spin_lock(&tx->lock);
1558 key = tx->key;
1559 if (key.active && tipc_aead_users(tx->aead[key.active]) > 0)
1560 goto s1;
1561 if (!key.pending || tipc_aead_users(tx->aead[key.pending]) <= 0)
1562 goto s1;
1563 if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_TIME))
1564 goto s1;
1565
1566 tipc_crypto_key_set_state(tx, key.passive, key.pending, 0);
1567 if (key.active)
1568 tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1569 this_cpu_inc(tx->stats->stat[STAT_SWITCHES]);
1570 pr_info("%s: key[%d] is activated\n", tx->name, key.pending);
1571
1572s1:
1573 spin_unlock(&tx->lock);
1574
1575 /* RX pending: having user -> active */
1576 spin_lock(&rx->lock);
1577 key = rx->key;
1578 if (!key.pending || tipc_aead_users(rx->aead[key.pending]) <= 0)
1579 goto s2;
1580
1581 if (key.active)
1582 key.passive = key.active;
1583 key.active = key.pending;
1584 rx->timer2 = jiffies;
1585 tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
1586 this_cpu_inc(rx->stats->stat[STAT_SWITCHES]);
1587 pr_info("%s: key[%d] is activated\n", rx->name, key.pending);
1588 goto s5;
1589
1590s2:
1591 /* RX pending: not working -> remove */
1592 if (!key.pending || tipc_aead_users(rx->aead[key.pending]) > -10)
1593 goto s3;
1594
1595 tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
1596 tipc_crypto_key_detach(rx->aead[key.pending], &rx->lock);
1597 pr_debug("%s: key[%d] is removed\n", rx->name, key.pending);
1598 goto s5;
1599
1600s3:
1601 /* RX active: timed out or no user -> pending */
1602 if (!key.active)
1603 goto s4;
1604 if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM) &&
1605 tipc_aead_users(rx->aead[key.active]) > 0)
1606 goto s4;
1607
1608 if (key.pending)
1609 key.passive = key.active;
1610 else
1611 key.pending = key.active;
1612 rx->timer2 = jiffies;
1613 tipc_crypto_key_set_state(rx, key.passive, 0, key.pending);
1614 tipc_aead_users_set(rx->aead[key.pending], 0);
1615 pr_debug("%s: key[%d] is deactivated\n", rx->name, key.active);
1616 goto s5;
1617
1618s4:
1619 /* RX passive: outdated or not working -> free */
1620 if (!key.passive)
1621 goto s5;
1622 if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM) &&
1623 tipc_aead_users(rx->aead[key.passive]) > -10)
1624 goto s5;
1625
1626 tipc_crypto_key_set_state(rx, 0, key.active, key.pending);
1627 tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock);
1628 pr_debug("%s: key[%d] is freed\n", rx->name, key.passive);
1629
1630s5:
1631 spin_unlock(&rx->lock);
1632
1633 /* Relax it here, the flag will be set again if it really is, but only
1634 * when we are not in grace period for safety!
1635 */
1636 if (time_after(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD))
1637 tx->legacy_user = 0;
1638
1639 /* Limit max_tfms & do debug commands if needed */
1640 if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM))
1641 return;
1642
1643 cmd = sysctl_tipc_max_tfms;
1644 sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF;
1645 tipc_crypto_do_cmd(rx->net, cmd);
1646}
1647
1648static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
1649 struct tipc_bearer *b,
1650 struct tipc_media_addr *dst,
1651 struct tipc_node *__dnode, u8 type)
1652{
1653 struct sk_buff *skb;
1654
1655 skb = skb_clone(_skb, GFP_ATOMIC);
1656 if (skb) {
1657 TIPC_SKB_CB(skb)->xmit_type = type;
1658 tipc_crypto_xmit(net, &skb, b, dst, __dnode);
1659 if (skb)
1660 b->media->send_msg(net, skb, b, dst);
1661 }
1662}
1663
1664/**
1665 * tipc_crypto_xmit - Build & encrypt TIPC message for xmit
1666 * @net: struct net
1667 * @skb: input/output message skb pointer
1668 * @b: bearer used for xmit later
1669 * @dst: destination media address
1670 * @__dnode: destination node for reference if any
1671 *
1672 * First, build an encryption message header on the top of the message, then
1673 * encrypt the original TIPC message by using the pending, master or active
1674 * key with this preference order.
1675 * If the encryption is successful, the encrypted skb is returned directly or
1676 * via the callback.
1677 * Otherwise, the skb is freed!
1678 *
1679 * Return:
1680 * * 0 : the encryption has succeeded (or no encryption)
1681 * * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made
1682 * * -ENOKEK : the encryption has failed due to no key
1683 * * -EKEYREVOKED : the encryption has failed due to key revoked
1684 * * -ENOMEM : the encryption has failed due to no memory
1685 * * < 0 : the encryption has failed due to other reasons
1686 */
1687int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
1688 struct tipc_bearer *b, struct tipc_media_addr *dst,
1689 struct tipc_node *__dnode)
1690{
1691 struct tipc_crypto *__rx = tipc_node_crypto_rx(__dnode);
1692 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1693 struct tipc_crypto_stats __percpu *stats = tx->stats;
1694 struct tipc_msg *hdr = buf_msg(*skb);
1695 struct tipc_key key = tx->key;
1696 struct tipc_aead *aead = NULL;
1697 u32 user = msg_user(hdr);
1698 u32 type = msg_type(hdr);
1699 int rc = -ENOKEY;
1700 u8 tx_key = 0;
1701
1702 /* No encryption? */
1703 if (!tx->working)
1704 return 0;
1705
1706 /* Pending key if peer has active on it or probing time */
1707 if (unlikely(key.pending)) {
1708 tx_key = key.pending;
1709 if (!tx->key_master && !key.active)
1710 goto encrypt;
1711 if (__rx && atomic_read(&__rx->peer_rx_active) == tx_key)
1712 goto encrypt;
1713 if (TIPC_SKB_CB(*skb)->xmit_type == SKB_PROBING) {
1714 pr_debug("%s: probing for key[%d]\n", tx->name,
1715 key.pending);
1716 goto encrypt;
1717 }
1718 if (user == LINK_CONFIG || user == LINK_PROTOCOL)
1719 tipc_crypto_clone_msg(net, *skb, b, dst, __dnode,
1720 SKB_PROBING);
1721 }
1722
1723 /* Master key if this is a *vital* message or in grace period */
1724 if (tx->key_master) {
1725 tx_key = KEY_MASTER;
1726 if (!key.active)
1727 goto encrypt;
1728 if (TIPC_SKB_CB(*skb)->xmit_type == SKB_GRACING) {
1729 pr_debug("%s: gracing for msg (%d %d)\n", tx->name,
1730 user, type);
1731 goto encrypt;
1732 }
1733 if (user == LINK_CONFIG ||
1734 (user == LINK_PROTOCOL && type == RESET_MSG) ||
1735 (user == MSG_CRYPTO && type == KEY_DISTR_MSG) ||
1736 time_before(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) {
1737 if (__rx && __rx->key_master &&
1738 !atomic_read(&__rx->peer_rx_active))
1739 goto encrypt;
1740 if (!__rx) {
1741 if (likely(!tx->legacy_user))
1742 goto encrypt;
1743 tipc_crypto_clone_msg(net, *skb, b, dst,
1744 __dnode, SKB_GRACING);
1745 }
1746 }
1747 }
1748
1749 /* Else, use the active key if any */
1750 if (likely(key.active)) {
1751 tx_key = key.active;
1752 goto encrypt;
1753 }
1754
1755 goto exit;
1756
1757encrypt:
1758 aead = tipc_aead_get(tx->aead[tx_key]);
1759 if (unlikely(!aead))
1760 goto exit;
1761 rc = tipc_ehdr_build(net, aead, tx_key, *skb, __rx);
1762 if (likely(rc > 0))
1763 rc = tipc_aead_encrypt(aead, *skb, b, dst, __dnode);
1764
1765exit:
1766 switch (rc) {
1767 case 0:
1768 this_cpu_inc(stats->stat[STAT_OK]);
1769 break;
1770 case -EINPROGRESS:
1771 case -EBUSY:
1772 this_cpu_inc(stats->stat[STAT_ASYNC]);
1773 *skb = NULL;
1774 return rc;
1775 default:
1776 this_cpu_inc(stats->stat[STAT_NOK]);
1777 if (rc == -ENOKEY)
1778 this_cpu_inc(stats->stat[STAT_NOKEYS]);
1779 else if (rc == -EKEYREVOKED)
1780 this_cpu_inc(stats->stat[STAT_BADKEYS]);
1781 kfree_skb(*skb);
1782 *skb = NULL;
1783 break;
1784 }
1785
1786 tipc_aead_put(aead);
1787 return rc;
1788}
1789
1790/**
1791 * tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer
1792 * @net: struct net
1793 * @rx: RX crypto handle
1794 * @skb: input/output message skb pointer
1795 * @b: bearer where the message has been received
1796 *
1797 * If the decryption is successful, the decrypted skb is returned directly or
1798 * as the callback, the encryption header and auth tag will be trimed out
1799 * before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete().
1800 * Otherwise, the skb will be freed!
1801 * Note: RX key(s) can be re-aligned, or in case of no key suitable, TX
1802 * cluster key(s) can be taken for decryption (- recursive).
1803 *
1804 * Return:
1805 * * 0 : the decryption has successfully completed
1806 * * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made
1807 * * -ENOKEY : the decryption has failed due to no key
1808 * * -EBADMSG : the decryption has failed due to bad message
1809 * * -ENOMEM : the decryption has failed due to no memory
1810 * * < 0 : the decryption has failed due to other reasons
1811 */
1812int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
1813 struct sk_buff **skb, struct tipc_bearer *b)
1814{
1815 struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1816 struct tipc_crypto_stats __percpu *stats;
1817 struct tipc_aead *aead = NULL;
1818 struct tipc_key key;
1819 int rc = -ENOKEY;
1820 u8 tx_key, n;
1821
1822 tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key;
1823
1824 /* New peer?
1825 * Let's try with TX key (i.e. cluster mode) & verify the skb first!
1826 */
1827 if (unlikely(!rx || tx_key == KEY_MASTER))
1828 goto pick_tx;
1829
1830 /* Pick RX key according to TX key if any */
1831 key = rx->key;
1832 if (tx_key == key.active || tx_key == key.pending ||
1833 tx_key == key.passive)
1834 goto decrypt;
1835
1836 /* Unknown key, let's try to align RX key(s) */
1837 if (tipc_crypto_key_try_align(rx, tx_key))
1838 goto decrypt;
1839
1840pick_tx:
1841 /* No key suitable? Try to pick one from TX... */
1842 aead = tipc_crypto_key_pick_tx(tx, rx, *skb, tx_key);
1843 if (aead)
1844 goto decrypt;
1845 goto exit;
1846
1847decrypt:
1848 rcu_read_lock();
1849 if (!aead)
1850 aead = tipc_aead_get(rx->aead[tx_key]);
1851 rc = tipc_aead_decrypt(net, aead, *skb, b);
1852 rcu_read_unlock();
1853
1854exit:
1855 stats = ((rx) ?: tx)->stats;
1856 switch (rc) {
1857 case 0:
1858 this_cpu_inc(stats->stat[STAT_OK]);
1859 break;
1860 case -EINPROGRESS:
1861 case -EBUSY:
1862 this_cpu_inc(stats->stat[STAT_ASYNC]);
1863 *skb = NULL;
1864 return rc;
1865 default:
1866 this_cpu_inc(stats->stat[STAT_NOK]);
1867 if (rc == -ENOKEY) {
1868 kfree_skb(*skb);
1869 *skb = NULL;
1870 if (rx) {
1871 /* Mark rx->nokey only if we dont have a
1872 * pending received session key, nor a newer
1873 * one i.e. in the next slot.
1874 */
1875 n = key_next(tx_key);
1876 rx->nokey = !(rx->skey ||
1877 rcu_access_pointer(rx->aead[n]));
1878 pr_debug_ratelimited("%s: nokey %d, key %d/%x\n",
1879 rx->name, rx->nokey,
1880 tx_key, rx->key.keys);
1881 tipc_node_put(rx->node);
1882 }
1883 this_cpu_inc(stats->stat[STAT_NOKEYS]);
1884 return rc;
1885 } else if (rc == -EBADMSG) {
1886 this_cpu_inc(stats->stat[STAT_BADMSGS]);
1887 }
1888 break;
1889 }
1890
1891 tipc_crypto_rcv_complete(net, aead, b, skb, rc);
1892 return rc;
1893}
1894
1895static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
1896 struct tipc_bearer *b,
1897 struct sk_buff **skb, int err)
1898{
1899 struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb);
1900 struct tipc_crypto *rx = aead->crypto;
1901 struct tipc_aead *tmp = NULL;
1902 struct tipc_ehdr *ehdr;
1903 struct tipc_node *n;
1904
1905 /* Is this completed by TX? */
1906 if (unlikely(is_tx(aead->crypto))) {
1907 rx = skb_cb->tx_clone_ctx.rx;
1908 pr_debug("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n",
1909 (rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead,
1910 (*skb)->next, skb_cb->flags);
1911 pr_debug("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n",
1912 skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last,
1913 aead->crypto->aead[1], aead->crypto->aead[2],
1914 aead->crypto->aead[3]);
1915 if (unlikely(err)) {
1916 if (err == -EBADMSG && (*skb)->next)
1917 tipc_rcv(net, (*skb)->next, b);
1918 goto free_skb;
1919 }
1920
1921 if (likely((*skb)->next)) {
1922 kfree_skb((*skb)->next);
1923 (*skb)->next = NULL;
1924 }
1925 ehdr = (struct tipc_ehdr *)(*skb)->data;
1926 if (!rx) {
1927 WARN_ON(ehdr->user != LINK_CONFIG);
1928 n = tipc_node_create(net, 0, ehdr->id, 0xffffu, 0,
1929 true);
1930 rx = tipc_node_crypto_rx(n);
1931 if (unlikely(!rx))
1932 goto free_skb;
1933 }
1934
1935 /* Ignore cloning if it was TX master key */
1936 if (ehdr->tx_key == KEY_MASTER)
1937 goto rcv;
1938 if (tipc_aead_clone(&tmp, aead) < 0)
1939 goto rcv;
1940 WARN_ON(!refcount_inc_not_zero(&tmp->refcnt));
1941 if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key, false) < 0) {
1942 tipc_aead_free(&tmp->rcu);
1943 goto rcv;
1944 }
1945 tipc_aead_put(aead);
1946 aead = tmp;
1947 }
1948
1949 if (unlikely(err)) {
1950 tipc_aead_users_dec((struct tipc_aead __force __rcu *)aead, INT_MIN);
1951 goto free_skb;
1952 }
1953
1954 /* Set the RX key's user */
1955 tipc_aead_users_set((struct tipc_aead __force __rcu *)aead, 1);
1956
1957 /* Mark this point, RX works */
1958 rx->timer1 = jiffies;
1959
1960rcv:
1961 /* Remove ehdr & auth. tag prior to tipc_rcv() */
1962 ehdr = (struct tipc_ehdr *)(*skb)->data;
1963
1964 /* Mark this point, RX passive still works */
1965 if (rx->key.passive && ehdr->tx_key == rx->key.passive)
1966 rx->timer2 = jiffies;
1967
1968 skb_reset_network_header(*skb);
1969 skb_pull(*skb, tipc_ehdr_size(ehdr));
1970 pskb_trim(*skb, (*skb)->len - aead->authsize);
1971
1972 /* Validate TIPCv2 message */
1973 if (unlikely(!tipc_msg_validate(skb))) {
1974 pr_err_ratelimited("Packet dropped after decryption!\n");
1975 goto free_skb;
1976 }
1977
1978 /* Ok, everything's fine, try to synch own keys according to peers' */
1979 tipc_crypto_key_synch(rx, *skb);
1980
1981 /* Mark skb decrypted */
1982 skb_cb->decrypted = 1;
1983
1984 /* Clear clone cxt if any */
1985 if (likely(!skb_cb->tx_clone_deferred))
1986 goto exit;
1987 skb_cb->tx_clone_deferred = 0;
1988 memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1989 goto exit;
1990
1991free_skb:
1992 kfree_skb(*skb);
1993 *skb = NULL;
1994
1995exit:
1996 tipc_aead_put(aead);
1997 if (rx)
1998 tipc_node_put(rx->node);
1999}
2000
2001static void tipc_crypto_do_cmd(struct net *net, int cmd)
2002{
2003 struct tipc_net *tn = tipc_net(net);
2004 struct tipc_crypto *tx = tn->crypto_tx, *rx;
2005 struct list_head *p;
2006 unsigned int stat;
2007 int i, j, cpu;
2008 char buf[200];
2009
2010 /* Currently only one command is supported */
2011 switch (cmd) {
2012 case 0xfff1:
2013 goto print_stats;
2014 default:
2015 return;
2016 }
2017
2018print_stats:
2019 /* Print a header */
2020 pr_info("\n=============== TIPC Crypto Statistics ===============\n\n");
2021
2022 /* Print key status */
2023 pr_info("Key status:\n");
2024 pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net),
2025 tipc_crypto_key_dump(tx, buf));
2026
2027 rcu_read_lock();
2028 for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2029 rx = tipc_node_crypto_rx_by_list(p);
2030 pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node),
2031 tipc_crypto_key_dump(rx, buf));
2032 }
2033 rcu_read_unlock();
2034
2035 /* Print crypto statistics */
2036 for (i = 0, j = 0; i < MAX_STATS; i++)
2037 j += scnprintf(buf + j, 200 - j, "|%11s ", hstats[i]);
2038 pr_info("Counter %s", buf);
2039
2040 memset(buf, '-', 115);
2041 buf[115] = '\0';
2042 pr_info("%s\n", buf);
2043
2044 j = scnprintf(buf, 200, "TX(%7.7s) ", tipc_own_id_string(net));
2045 for_each_possible_cpu(cpu) {
2046 for (i = 0; i < MAX_STATS; i++) {
2047 stat = per_cpu_ptr(tx->stats, cpu)->stat[i];
2048 j += scnprintf(buf + j, 200 - j, "|%11d ", stat);
2049 }
2050 pr_info("%s", buf);
2051 j = scnprintf(buf, 200, "%12s", " ");
2052 }
2053
2054 rcu_read_lock();
2055 for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2056 rx = tipc_node_crypto_rx_by_list(p);
2057 j = scnprintf(buf, 200, "RX(%7.7s) ",
2058 tipc_node_get_id_str(rx->node));
2059 for_each_possible_cpu(cpu) {
2060 for (i = 0; i < MAX_STATS; i++) {
2061 stat = per_cpu_ptr(rx->stats, cpu)->stat[i];
2062 j += scnprintf(buf + j, 200 - j, "|%11d ",
2063 stat);
2064 }
2065 pr_info("%s", buf);
2066 j = scnprintf(buf, 200, "%12s", " ");
2067 }
2068 }
2069 rcu_read_unlock();
2070
2071 pr_info("\n======================== Done ========================\n");
2072}
2073
2074static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf)
2075{
2076 struct tipc_key key = c->key;
2077 struct tipc_aead *aead;
2078 int k, i = 0;
2079 char *s;
2080
2081 for (k = KEY_MIN; k <= KEY_MAX; k++) {
2082 if (k == KEY_MASTER) {
2083 if (is_rx(c))
2084 continue;
2085 if (time_before(jiffies,
2086 c->timer2 + TIPC_TX_GRACE_PERIOD))
2087 s = "ACT";
2088 else
2089 s = "PAS";
2090 } else {
2091 if (k == key.passive)
2092 s = "PAS";
2093 else if (k == key.active)
2094 s = "ACT";
2095 else if (k == key.pending)
2096 s = "PEN";
2097 else
2098 s = "-";
2099 }
2100 i += scnprintf(buf + i, 200 - i, "\tKey%d: %s", k, s);
2101
2102 rcu_read_lock();
2103 aead = rcu_dereference(c->aead[k]);
2104 if (aead)
2105 i += scnprintf(buf + i, 200 - i,
2106 "{\"0x...%s\", \"%s\"}/%d:%d",
2107 aead->hint,
2108 (aead->mode == CLUSTER_KEY) ? "c" : "p",
2109 atomic_read(&aead->users),
2110 refcount_read(&aead->refcnt));
2111 rcu_read_unlock();
2112 i += scnprintf(buf + i, 200 - i, "\n");
2113 }
2114
2115 if (is_rx(c))
2116 i += scnprintf(buf + i, 200 - i, "\tPeer RX active: %d\n",
2117 atomic_read(&c->peer_rx_active));
2118
2119 return buf;
2120}
2121
2122static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
2123 char *buf)
2124{
2125 struct tipc_key *key = &old;
2126 int k, i = 0;
2127 char *s;
2128
2129 /* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */
2130again:
2131 i += scnprintf(buf + i, 32 - i, "[");
2132 for (k = KEY_1; k <= KEY_3; k++) {
2133 if (k == key->passive)
2134 s = "pas";
2135 else if (k == key->active)
2136 s = "act";
2137 else if (k == key->pending)
2138 s = "pen";
2139 else
2140 s = "-";
2141 i += scnprintf(buf + i, 32 - i,
2142 (k != KEY_3) ? "%s " : "%s", s);
2143 }
2144 if (key != &new) {
2145 i += scnprintf(buf + i, 32 - i, "] -> ");
2146 key = &new;
2147 goto again;
2148 }
2149 i += scnprintf(buf + i, 32 - i, "]");
2150 return buf;
2151}
2152
2153/**
2154 * tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point
2155 * @net: the struct net
2156 * @skb: the receiving message buffer
2157 */
2158void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb)
2159{
2160 struct tipc_crypto *rx;
2161 struct tipc_msg *hdr;
2162
2163 if (unlikely(skb_linearize(skb)))
2164 goto exit;
2165
2166 hdr = buf_msg(skb);
2167 rx = tipc_node_crypto_rx_by_addr(net, msg_prevnode(hdr));
2168 if (unlikely(!rx))
2169 goto exit;
2170
2171 switch (msg_type(hdr)) {
2172 case KEY_DISTR_MSG:
2173 if (tipc_crypto_key_rcv(rx, hdr))
2174 goto exit;
2175 break;
2176 default:
2177 break;
2178 }
2179
2180 tipc_node_put(rx->node);
2181
2182exit:
2183 kfree_skb(skb);
2184}
2185
2186/**
2187 * tipc_crypto_key_distr - Distribute a TX key
2188 * @tx: the TX crypto
2189 * @key: the key's index
2190 * @dest: the destination tipc node, = NULL if distributing to all nodes
2191 *
2192 * Return: 0 in case of success, otherwise < 0
2193 */
2194int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key,
2195 struct tipc_node *dest)
2196{
2197 struct tipc_aead *aead;
2198 u32 dnode = tipc_node_get_addr(dest);
2199 int rc = -ENOKEY;
2200
2201 if (!sysctl_tipc_key_exchange_enabled)
2202 return 0;
2203
2204 if (key) {
2205 rcu_read_lock();
2206 aead = tipc_aead_get(tx->aead[key]);
2207 if (likely(aead)) {
2208 rc = tipc_crypto_key_xmit(tx->net, aead->key,
2209 aead->gen, aead->mode,
2210 dnode);
2211 tipc_aead_put(aead);
2212 }
2213 rcu_read_unlock();
2214 }
2215
2216 return rc;
2217}
2218
2219/**
2220 * tipc_crypto_key_xmit - Send a session key
2221 * @net: the struct net
2222 * @skey: the session key to be sent
2223 * @gen: the key's generation
2224 * @mode: the key's mode
2225 * @dnode: the destination node address, = 0 if broadcasting to all nodes
2226 *
2227 * The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG'
2228 * as its data section, then xmit-ed through the uc/bc link.
2229 *
2230 * Return: 0 in case of success, otherwise < 0
2231 */
2232static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
2233 u16 gen, u8 mode, u32 dnode)
2234{
2235 struct sk_buff_head pkts;
2236 struct tipc_msg *hdr;
2237 struct sk_buff *skb;
2238 u16 size, cong_link_cnt;
2239 u8 *data;
2240 int rc;
2241
2242 size = tipc_aead_key_size(skey);
2243 skb = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
2244 if (!skb)
2245 return -ENOMEM;
2246
2247 hdr = buf_msg(skb);
2248 tipc_msg_init(tipc_own_addr(net), hdr, MSG_CRYPTO, KEY_DISTR_MSG,
2249 INT_H_SIZE, dnode);
2250 msg_set_size(hdr, INT_H_SIZE + size);
2251 msg_set_key_gen(hdr, gen);
2252 msg_set_key_mode(hdr, mode);
2253
2254 data = msg_data(hdr);
2255 *((__be32 *)(data + TIPC_AEAD_ALG_NAME)) = htonl(skey->keylen);
2256 memcpy(data, skey->alg_name, TIPC_AEAD_ALG_NAME);
2257 memcpy(data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->key,
2258 skey->keylen);
2259
2260 __skb_queue_head_init(&pkts);
2261 __skb_queue_tail(&pkts, skb);
2262 if (dnode)
2263 rc = tipc_node_xmit(net, &pkts, dnode, 0);
2264 else
2265 rc = tipc_bcast_xmit(net, &pkts, &cong_link_cnt);
2266
2267 return rc;
2268}
2269
2270/**
2271 * tipc_crypto_key_rcv - Receive a session key
2272 * @rx: the RX crypto
2273 * @hdr: the TIPC v2 message incl. the receiving session key in its data
2274 *
2275 * This function retrieves the session key in the message from peer, then
2276 * schedules a RX work to attach the key to the corresponding RX crypto.
2277 *
2278 * Return: "true" if the key has been scheduled for attaching, otherwise
2279 * "false".
2280 */
2281static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr)
2282{
2283 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
2284 struct tipc_aead_key *skey = NULL;
2285 u16 key_gen = msg_key_gen(hdr);
2286 u16 size = msg_data_sz(hdr);
2287 u8 *data = msg_data(hdr);
2288
2289 spin_lock(&rx->lock);
2290 if (unlikely(rx->skey || (key_gen == rx->key_gen && rx->key.keys))) {
2291 pr_err("%s: key existed <%p>, gen %d vs %d\n", rx->name,
2292 rx->skey, key_gen, rx->key_gen);
2293 goto exit;
2294 }
2295
2296 /* Allocate memory for the key */
2297 skey = kmalloc(size, GFP_ATOMIC);
2298 if (unlikely(!skey)) {
2299 pr_err("%s: unable to allocate memory for skey\n", rx->name);
2300 goto exit;
2301 }
2302
2303 /* Copy key from msg data */
2304 skey->keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME)));
2305 memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME);
2306 memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32),
2307 skey->keylen);
2308
2309 /* Sanity check */
2310 if (unlikely(size != tipc_aead_key_size(skey))) {
2311 kfree(skey);
2312 skey = NULL;
2313 goto exit;
2314 }
2315
2316 rx->key_gen = key_gen;
2317 rx->skey_mode = msg_key_mode(hdr);
2318 rx->skey = skey;
2319 rx->nokey = 0;
2320 mb(); /* for nokey flag */
2321
2322exit:
2323 spin_unlock(&rx->lock);
2324
2325 /* Schedule the key attaching on this crypto */
2326 if (likely(skey && queue_delayed_work(tx->wq, &rx->work, 0)))
2327 return true;
2328
2329 return false;
2330}
2331
2332/**
2333 * tipc_crypto_work_rx - Scheduled RX works handler
2334 * @work: the struct RX work
2335 *
2336 * The function processes the previous scheduled works i.e. distributing TX key
2337 * or attaching a received session key on RX crypto.
2338 */
2339static void tipc_crypto_work_rx(struct work_struct *work)
2340{
2341 struct delayed_work *dwork = to_delayed_work(work);
2342 struct tipc_crypto *rx = container_of(dwork, struct tipc_crypto, work);
2343 struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
2344 unsigned long delay = msecs_to_jiffies(5000);
2345 bool resched = false;
2346 u8 key;
2347 int rc;
2348
2349 /* Case 1: Distribute TX key to peer if scheduled */
2350 if (atomic_cmpxchg(&rx->key_distr,
2351 KEY_DISTR_SCHED,
2352 KEY_DISTR_COMPL) == KEY_DISTR_SCHED) {
2353 /* Always pick the newest one for distributing */
2354 key = tx->key.pending ?: tx->key.active;
2355 rc = tipc_crypto_key_distr(tx, key, rx->node);
2356 if (unlikely(rc))
2357 pr_warn("%s: unable to distr key[%d] to %s, err %d\n",
2358 tx->name, key, tipc_node_get_id_str(rx->node),
2359 rc);
2360
2361 /* Sched for key_distr releasing */
2362 resched = true;
2363 } else {
2364 atomic_cmpxchg(&rx->key_distr, KEY_DISTR_COMPL, 0);
2365 }
2366
2367 /* Case 2: Attach a pending received session key from peer if any */
2368 if (rx->skey) {
2369 rc = tipc_crypto_key_init(rx, rx->skey, rx->skey_mode, false);
2370 if (unlikely(rc < 0))
2371 pr_warn("%s: unable to attach received skey, err %d\n",
2372 rx->name, rc);
2373 switch (rc) {
2374 case -EBUSY:
2375 case -ENOMEM:
2376 /* Resched the key attaching */
2377 resched = true;
2378 break;
2379 default:
2380 synchronize_rcu();
2381 kfree(rx->skey);
2382 rx->skey = NULL;
2383 break;
2384 }
2385 }
2386
2387 if (resched && queue_delayed_work(tx->wq, &rx->work, delay))
2388 return;
2389
2390 tipc_node_put(rx->node);
2391}
2392
2393/**
2394 * tipc_crypto_rekeying_sched - (Re)schedule rekeying w/o new interval
2395 * @tx: TX crypto
2396 * @changed: if the rekeying needs to be rescheduled with new interval
2397 * @new_intv: new rekeying interval (when "changed" = true)
2398 */
2399void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed,
2400 u32 new_intv)
2401{
2402 unsigned long delay;
2403 bool now = false;
2404
2405 if (changed) {
2406 if (new_intv == TIPC_REKEYING_NOW)
2407 now = true;
2408 else
2409 tx->rekeying_intv = new_intv;
2410 cancel_delayed_work_sync(&tx->work);
2411 }
2412
2413 if (tx->rekeying_intv || now) {
2414 delay = (now) ? 0 : tx->rekeying_intv * 60 * 1000;
2415 queue_delayed_work(tx->wq, &tx->work, msecs_to_jiffies(delay));
2416 }
2417}
2418
2419/**
2420 * tipc_crypto_work_tx - Scheduled TX works handler
2421 * @work: the struct TX work
2422 *
2423 * The function processes the previous scheduled work, i.e. key rekeying, by
2424 * generating a new session key based on current one, then attaching it to the
2425 * TX crypto and finally distributing it to peers. It also re-schedules the
2426 * rekeying if needed.
2427 */
2428static void tipc_crypto_work_tx(struct work_struct *work)
2429{
2430 struct delayed_work *dwork = to_delayed_work(work);
2431 struct tipc_crypto *tx = container_of(dwork, struct tipc_crypto, work);
2432 struct tipc_aead_key *skey = NULL;
2433 struct tipc_key key = tx->key;
2434 struct tipc_aead *aead;
2435 int rc = -ENOMEM;
2436
2437 if (unlikely(key.pending))
2438 goto resched;
2439
2440 /* Take current key as a template */
2441 rcu_read_lock();
2442 aead = rcu_dereference(tx->aead[key.active ?: KEY_MASTER]);
2443 if (unlikely(!aead)) {
2444 rcu_read_unlock();
2445 /* At least one key should exist for securing */
2446 return;
2447 }
2448
2449 /* Lets duplicate it first */
2450 skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_ATOMIC);
2451 rcu_read_unlock();
2452
2453 /* Now, generate new key, initiate & distribute it */
2454 if (likely(skey)) {
2455 rc = tipc_aead_key_generate(skey) ?:
2456 tipc_crypto_key_init(tx, skey, PER_NODE_KEY, false);
2457 if (likely(rc > 0))
2458 rc = tipc_crypto_key_distr(tx, rc, NULL);
2459 kfree_sensitive(skey);
2460 }
2461
2462 if (unlikely(rc))
2463 pr_warn_ratelimited("%s: rekeying returns %d\n", tx->name, rc);
2464
2465resched:
2466 /* Re-schedule rekeying if any */
2467 tipc_crypto_rekeying_sched(tx, false, 0);
2468}