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	*/
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	*/
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(tfm: crypto_default_rng, rdata: skey->key,
376	dlen: skey->keylen);
377	crypto_put_default_rng();
378	}
379
380	return rc;
381	}
382
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
396	static inline void tipc_aead_put(struct tipc_aead *aead)
397	{
398	if (aead && refcount_dec_and_test(r: &aead->refcnt))
399	call_rcu(head: &aead->rcu, func: 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	*/
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: 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: tfm_entry->tfm);
418	list_del(entry: &tfm_entry->list);
419	kfree(objp: tfm_entry);
420	}
421	/* Free the head */
422	crypto_free_aead(tfm: head->tfm);
423	list_del(entry: &head->list);
424	kfree(objp: head);
425	}
426	free_percpu(pdata: aead->tfm_entry);
427	kfree_sensitive(objp: aead->key);
428	kfree_sensitive(objp: aead);
429	}
430
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(v: &tmp->users);
440	rcu_read_unlock();
441
442	return users;
443	}
444
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(v: &tmp->users, a: 1, u: lim);
453	rcu_read_unlock();
454	}
455
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(v: &rcu_dereference(aead)->users, a: -1, u: lim);
464	rcu_read_unlock();
465	}
466
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(v: &tmp->users);
477	if (cur == val)
478	break;
479	} while (atomic_cmpxchg(v: &tmp->users, old: cur, new: 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	*/
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	*/
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(objp: tmp);
538	return -ENOMEM;
539	}
540
541	/* Make a list of TFMs with the user key data */
542	do {
543	tfm = crypto_alloc_aead(alg_name: ukey->alg_name, type: 0, mask: 0);
544	if (IS_ERR(ptr: tfm)) {
545	err = PTR_ERR(ptr: 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, key: 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(list: &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(new: &tfm_entry->list, head: &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(pdata: tmp->tfm_entry);
587	kfree_sensitive(objp: tmp);
588	return err;
589	}
590
591	/* Form a hex string of some last bytes as the key's hint */
592	bin2hex(dst: tmp->hint, src: 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(rp: &tmp->rcu);
602	return -ENOMEM;
603	}
604	memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
605	atomic_set(v: &tmp->users, i: 0);
606	atomic64_set(v: &tmp->seqno, i: 0);
607	refcount_set(r: &tmp->refcnt, n: 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	*/
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(objp: 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(v: &aead->users, i: 0);
660	atomic64_set(v: &aead->seqno, i: 0);
661	refcount_set(r: &aead->refcnt, n: 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	*/
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	*/
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, tailbits: tailen, trailer: &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, tail: trailer, len: tailen);
771
772	/* Allocate memory for the AEAD operation */
773	ctx = tipc_aead_mem_alloc(tfm, crypto_ctx_size: sizeof(*tx_ctx), iv: &iv, req: &req, sg: &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, offset: 0, len: 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(node: __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, assoclen: ehsz);
804	aead_request_set_crypt(req, src: sg, dst: sg, cryptlen: len - ehsz, iv);
805
806	/* Set callback function & data */
807	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
808	compl: tipc_aead_encrypt_done, data: 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	/* Get net to avoid freed tipc_crypto when delete namespace */
821	if (!maybe_get_net(net: aead->crypto->net)) {
822	tipc_bearer_put(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	put_net(net: aead->crypto->net);
834
835	exit:
836	kfree(objp: ctx);
837	TIPC_SKB_CB(skb)->crypto_ctx = NULL;
838	return rc;
839	}
840
841	static void tipc_aead_encrypt_done(void *data, int err)
842	{
843	struct sk_buff *skb = data;
844	struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
845	struct tipc_bearer *b = tx_ctx->bearer;
846	struct tipc_aead *aead = tx_ctx->aead;
847	struct tipc_crypto *tx = aead->crypto;
848	struct net *net = tx->net;
849
850	switch (err) {
851	case 0:
852	this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]);
853	rcu_read_lock();
854	if (likely(test_bit(0, &b->up)))
855	b->media->send_msg(net, skb, b, &tx_ctx->dst);
856	else
857	kfree_skb(skb);
858	rcu_read_unlock();
859	break;
860	case -EINPROGRESS:
861	return;
862	default:
863	this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]);
864	kfree_skb(skb);
865	break;
866	}
867
868	kfree(objp: tx_ctx);
869	tipc_bearer_put(b);
870	tipc_aead_put(aead);
871	put_net(net);
872	}
873
874	/**
875	* tipc_aead_decrypt - Decrypt an encrypted message
876	* @net: struct net
877	* @aead: TIPC AEAD for the message decryption
878	* @skb: the input/output skb
879	* @b: TIPC bearer where the message has been received
880	*
881	* Return:
882	* * 0 : if the decryption has completed
883	* * -EINPROGRESS/-EBUSY : if a callback will be performed
884	* * < 0 : the decryption has failed
885	*/
886	static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
887	struct sk_buff *skb, struct tipc_bearer *b)
888	{
889	struct tipc_crypto_rx_ctx *rx_ctx;
890	struct aead_request *req;
891	struct crypto_aead *tfm;
892	struct sk_buff *unused;
893	struct scatterlist *sg;
894	struct tipc_ehdr *ehdr;
895	int ehsz, nsg, rc;
896	void *ctx;
897	u32 salt;
898	u8 *iv;
899
900	if (unlikely(!aead))
901	return -ENOKEY;
902
903	nsg = skb_cow_data(skb, tailbits: 0, trailer: &unused);
904	if (unlikely(nsg < 0)) {
905	pr_err("RX: skb_cow_data() returned %d\n", nsg);
906	return nsg;
907	}
908
909	/* Allocate memory for the AEAD operation */
910	tfm = tipc_aead_tfm_next(aead);
911	ctx = tipc_aead_mem_alloc(tfm, crypto_ctx_size: sizeof(*rx_ctx), iv: &iv, req: &req, sg: &sg, nsg);
912	if (unlikely(!ctx))
913	return -ENOMEM;
914	TIPC_SKB_CB(skb)->crypto_ctx = ctx;
915
916	/* Map skb to the sg lists */
917	sg_init_table(sg, nsg);
918	rc = skb_to_sgvec(skb, sg, offset: 0, len: skb->len);
919	if (unlikely(rc < 0)) {
920	pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg);
921	goto exit;
922	}
923
924	/* Reconstruct IV: */
925	ehdr = (struct tipc_ehdr *)skb->data;
926	salt = aead->salt;
927	if (aead->mode == CLUSTER_KEY)
928	salt ^= __be32_to_cpu(ehdr->addr);
929	else if (ehdr->destined)
930	salt ^= tipc_own_addr(net);
931	memcpy(iv, &salt, 4);
932	memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
933
934	/* Prepare request */
935	ehsz = tipc_ehdr_size(ehdr);
936	aead_request_set_tfm(req, tfm);
937	aead_request_set_ad(req, assoclen: ehsz);
938	aead_request_set_crypt(req, src: sg, dst: sg, cryptlen: skb->len - ehsz, iv);
939
940	/* Set callback function & data */
941	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
942	compl: tipc_aead_decrypt_done, data: skb);
943	rx_ctx = (struct tipc_crypto_rx_ctx *)ctx;
944	rx_ctx->aead = aead;
945	rx_ctx->bearer = b;
946
947	/* Hold bearer */
948	if (unlikely(!tipc_bearer_hold(b))) {
949	rc = -ENODEV;
950	goto exit;
951	}
952
953	/* Now, do decrypt */
954	rc = crypto_aead_decrypt(req);
955	if (rc == -EINPROGRESS || rc == -EBUSY)
956	return rc;
957
958	tipc_bearer_put(b);
959
960	exit:
961	kfree(objp: ctx);
962	TIPC_SKB_CB(skb)->crypto_ctx = NULL;
963	return rc;
964	}
965
966	static void tipc_aead_decrypt_done(void *data, int err)
967	{
968	struct sk_buff *skb = data;
969	struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
970	struct tipc_bearer *b = rx_ctx->bearer;
971	struct tipc_aead *aead = rx_ctx->aead;
972	struct tipc_crypto_stats __percpu *stats = aead->crypto->stats;
973	struct net *net = aead->crypto->net;
974
975	switch (err) {
976	case 0:
977	this_cpu_inc(stats->stat[STAT_ASYNC_OK]);
978	break;
979	case -EINPROGRESS:
980	return;
981	default:
982	this_cpu_inc(stats->stat[STAT_ASYNC_NOK]);
983	break;
984	}
985
986	kfree(objp: rx_ctx);
987	tipc_crypto_rcv_complete(net, aead, b, skb: &skb, err);
988	if (likely(skb)) {
989	if (likely(test_bit(0, &b->up)))
990	tipc_rcv(net, skb, b);
991	else
992	kfree_skb(skb);
993	}
994
995	tipc_bearer_put(b);
996	}
997
998	static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr)
999	{
1000	return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
1001	}
1002
1003	/**
1004	* tipc_ehdr_validate - Validate an encryption message
1005	* @skb: the message buffer
1006	*
1007	* Return: "true" if this is a valid encryption message, otherwise "false"
1008	*/
1009	bool tipc_ehdr_validate(struct sk_buff *skb)
1010	{
1011	struct tipc_ehdr *ehdr;
1012	int ehsz;
1013
1014	if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE)))
1015	return false;
1016
1017	ehdr = (struct tipc_ehdr *)skb->data;
1018	if (unlikely(ehdr->version != TIPC_EVERSION))
1019	return false;
1020	ehsz = tipc_ehdr_size(ehdr);
1021	if (unlikely(!pskb_may_pull(skb, ehsz)))
1022	return false;
1023	if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE))
1024	return false;
1025
1026	return true;
1027	}
1028
1029	/**
1030	* tipc_ehdr_build - Build TIPC encryption message header
1031	* @net: struct net
1032	* @aead: TX AEAD key to be used for the message encryption
1033	* @tx_key: key id used for the message encryption
1034	* @skb: input/output message skb
1035	* @__rx: RX crypto handle if dest is "known"
1036	*
1037	* Return: the header size if the building is successful, otherwise < 0
1038	*/
1039	static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
1040	u8 tx_key, struct sk_buff *skb,
1041	struct tipc_crypto *__rx)
1042	{
1043	struct tipc_msg *hdr = buf_msg(skb);
1044	struct tipc_ehdr *ehdr;
1045	u32 user = msg_user(m: hdr);
1046	u64 seqno;
1047	int ehsz;
1048
1049	/* Make room for encryption header */
1050	ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
1051	WARN_ON(skb_headroom(skb) < ehsz);
1052	ehdr = (struct tipc_ehdr *)skb_push(skb, len: ehsz);
1053
1054	/* Obtain a seqno first:
1055	* Use the key seqno (= cluster wise) if dest is unknown or we're in
1056	* cluster key mode, otherwise it's better for a per-peer seqno!
1057	*/
1058	if (!__rx || aead->mode == CLUSTER_KEY)
1059	seqno = atomic64_inc_return(v: &aead->seqno);
1060	else
1061	seqno = atomic64_inc_return(v: &__rx->sndnxt);
1062
1063	/* Revoke the key if seqno is wrapped around */
1064	if (unlikely(!seqno))
1065	return tipc_crypto_key_revoke(net, tx_key);
1066
1067	/* Word 1-2 */
1068	ehdr->seqno = cpu_to_be64(seqno);
1069
1070	/* Words 0, 3- */
1071	ehdr->version = TIPC_EVERSION;
1072	ehdr->user = 0;
1073	ehdr->keepalive = 0;
1074	ehdr->tx_key = tx_key;
1075	ehdr->destined = (__rx) ? 1 : 0;
1076	ehdr->rx_key_active = (__rx) ? __rx->key.active : 0;
1077	ehdr->rx_nokey = (__rx) ? __rx->nokey : 0;
1078	ehdr->master_key = aead->crypto->key_master;
1079	ehdr->reserved_1 = 0;
1080	ehdr->reserved_2 = 0;
1081
1082	switch (user) {
1083	case LINK_CONFIG:
1084	ehdr->user = LINK_CONFIG;
1085	memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN);
1086	break;
1087	default:
1088	if (user == LINK_PROTOCOL && msg_type(m: hdr) == STATE_MSG) {
1089	ehdr->user = LINK_PROTOCOL;
1090	ehdr->keepalive = msg_is_keepalive(m: hdr);
1091	}
1092	ehdr->addr = hdr->hdr[3];
1093	break;
1094	}
1095
1096	return ehsz;
1097	}
1098
1099	static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
1100	u8 new_passive,
1101	u8 new_active,
1102	u8 new_pending)
1103	{
1104	struct tipc_key old = c->key;
1105	char buf[32];
1106
1107	c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) |
1108	((new_active & KEY_MASK) << (KEY_BITS)) |
1109	((new_pending & KEY_MASK));
1110
1111	pr_debug("%s: key changing %s ::%pS\n", c->name,
1112	tipc_key_change_dump(old, c->key, buf),
1113	__builtin_return_address(0));
1114	}
1115
1116	/**
1117	* tipc_crypto_key_init - Initiate a new user / AEAD key
1118	* @c: TIPC crypto to which new key is attached
1119	* @ukey: the user key
1120	* @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY)
1121	* @master_key: specify this is a cluster master key
1122	*
1123	* A new TIPC AEAD key will be allocated and initiated with the specified user
1124	* key, then attached to the TIPC crypto.
1125	*
1126	* Return: new key id in case of success, otherwise: < 0
1127	*/
1128	int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
1129	u8 mode, bool master_key)
1130	{
1131	struct tipc_aead *aead = NULL;
1132	int rc = 0;
1133
1134	/* Initiate with the new user key */
1135	rc = tipc_aead_init(aead: &aead, ukey, mode);
1136
1137	/* Attach it to the crypto */
1138	if (likely(!rc)) {
1139	rc = tipc_crypto_key_attach(c, aead, pos: 0, master_key);
1140	if (rc < 0)
1141	tipc_aead_free(rp: &aead->rcu);
1142	}
1143
1144	return rc;
1145	}
1146
1147	/**
1148	* tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto
1149	* @c: TIPC crypto to which the new AEAD key is attached
1150	* @aead: the new AEAD key pointer
1151	* @pos: desired slot in the crypto key array, = 0 if any!
1152	* @master_key: specify this is a cluster master key
1153	*
1154	* Return: new key id in case of success, otherwise: -EBUSY
1155	*/
1156	static int tipc_crypto_key_attach(struct tipc_crypto *c,
1157	struct tipc_aead *aead, u8 pos,
1158	bool master_key)
1159	{
1160	struct tipc_key key;
1161	int rc = -EBUSY;
1162	u8 new_key;
1163
1164	spin_lock_bh(lock: &c->lock);
1165	key = c->key;
1166	if (master_key) {
1167	new_key = KEY_MASTER;
1168	goto attach;
1169	}
1170	if (key.active && key.passive)
1171	goto exit;
1172	if (key.pending) {
1173	if (tipc_aead_users(aead: c->aead[key.pending]) > 0)
1174	goto exit;
1175	/* if (pos): ok with replacing, will be aligned when needed */
1176	/* Replace it */
1177	new_key = key.pending;
1178	} else {
1179	if (pos) {
1180	if (key.active && pos != key_next(key.active)) {
1181	key.passive = pos;
1182	new_key = pos;
1183	goto attach;
1184	} else if (!key.active && !key.passive) {
1185	key.pending = pos;
1186	new_key = pos;
1187	goto attach;
1188	}
1189	}
1190	key.pending = key_next(key.active ?: key.passive);
1191	new_key = key.pending;
1192	}
1193
1194	attach:
1195	aead->crypto = c;
1196	aead->gen = (is_tx(c)) ? ++c->key_gen : c->key_gen;
1197	tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock);
1198	if (likely(c->key.keys != key.keys))
1199	tipc_crypto_key_set_state(c, new_passive: key.passive, new_active: key.active,
1200	new_pending: key.pending);
1201	c->working = 1;
1202	c->nokey = 0;
1203	c->key_master |= master_key;
1204	rc = new_key;
1205
1206	exit:
1207	spin_unlock_bh(lock: &c->lock);
1208	return rc;
1209	}
1210
1211	void tipc_crypto_key_flush(struct tipc_crypto *c)
1212	{
1213	struct tipc_crypto *tx, *rx;
1214	int k;
1215
1216	spin_lock_bh(lock: &c->lock);
1217	if (is_rx(c)) {
1218	/* Try to cancel pending work */
1219	rx = c;
1220	tx = tipc_net(net: rx->net)->crypto_tx;
1221	if (cancel_delayed_work(dwork: &rx->work)) {
1222	kfree_sensitive(objp: rx->skey);
1223	rx->skey = NULL;
1224	atomic_xchg(v: &rx->key_distr, new: 0);
1225	tipc_node_put(node: rx->node);
1226	}
1227	/* RX stopping => decrease TX key users if any */
1228	k = atomic_xchg(v: &rx->peer_rx_active, new: 0);
1229	if (k) {
1230	tipc_aead_users_dec(aead: tx->aead[k], lim: 0);
1231	/* Mark the point TX key users changed */
1232	tx->timer1 = jiffies;
1233	}
1234	}
1235
1236	c->flags = 0;
1237	tipc_crypto_key_set_state(c, new_passive: 0, new_active: 0, new_pending: 0);
1238	for (k = KEY_MIN; k <= KEY_MAX; k++)
1239	tipc_crypto_key_detach(c->aead[k], &c->lock);
1240	atomic64_set(v: &c->sndnxt, i: 0);
1241	spin_unlock_bh(lock: &c->lock);
1242	}
1243
1244	/**
1245	* tipc_crypto_key_try_align - Align RX keys if possible
1246	* @rx: RX crypto handle
1247	* @new_pending: new pending slot if aligned (= TX key from peer)
1248	*
1249	* Peer has used an unknown key slot, this only happens when peer has left and
1250	* rejoned, or we are newcomer.
1251	* That means, there must be no active key but a pending key at unaligned slot.
1252	* If so, we try to move the pending key to the new slot.
1253	* Note: A potential passive key can exist, it will be shifted correspondingly!
1254	*
1255	* Return: "true" if key is successfully aligned, otherwise "false"
1256	*/
1257	static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
1258	{
1259	struct tipc_aead *tmp1, *tmp2 = NULL;
1260	struct tipc_key key;
1261	bool aligned = false;
1262	u8 new_passive = 0;
1263	int x;
1264
1265	spin_lock(lock: &rx->lock);
1266	key = rx->key;
1267	if (key.pending == new_pending) {
1268	aligned = true;
1269	goto exit;
1270	}
1271	if (key.active)
1272	goto exit;
1273	if (!key.pending)
1274	goto exit;
1275	if (tipc_aead_users(aead: rx->aead[key.pending]) > 0)
1276	goto exit;
1277
1278	/* Try to "isolate" this pending key first */
1279	tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock);
1280	if (!refcount_dec_if_one(r: &tmp1->refcnt))
1281	goto exit;
1282	rcu_assign_pointer(rx->aead[key.pending], NULL);
1283
1284	/* Move passive key if any */
1285	if (key.passive) {
1286	tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock));
1287	x = (key.passive - key.pending + new_pending) % KEY_MAX;
1288	new_passive = (x <= 0) ? x + KEY_MAX : x;
1289	}
1290
1291	/* Re-allocate the key(s) */
1292	tipc_crypto_key_set_state(c: rx, new_passive, new_active: 0, new_pending);
1293	rcu_assign_pointer(rx->aead[new_pending], tmp1);
1294	if (new_passive)
1295	rcu_assign_pointer(rx->aead[new_passive], tmp2);
1296	refcount_set(r: &tmp1->refcnt, n: 1);
1297	aligned = true;
1298	pr_info_ratelimited("%s: key[%d] -> key[%d]\n", rx->name, key.pending,
1299	new_pending);
1300
1301	exit:
1302	spin_unlock(lock: &rx->lock);
1303	return aligned;
1304	}
1305
1306	/**
1307	* tipc_crypto_key_pick_tx - Pick one TX key for message decryption
1308	* @tx: TX crypto handle
1309	* @rx: RX crypto handle (can be NULL)
1310	* @skb: the message skb which will be decrypted later
1311	* @tx_key: peer TX key id
1312	*
1313	* This function looks up the existing TX keys and pick one which is suitable
1314	* for the message decryption, that must be a cluster key and not used before
1315	* on the same message (i.e. recursive).
1316	*
1317	* Return: the TX AEAD key handle in case of success, otherwise NULL
1318	*/
1319	static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
1320	struct tipc_crypto *rx,
1321	struct sk_buff *skb,
1322	u8 tx_key)
1323	{
1324	struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb);
1325	struct tipc_aead *aead = NULL;
1326	struct tipc_key key = tx->key;
1327	u8 k, i = 0;
1328
1329	/* Initialize data if not yet */
1330	if (!skb_cb->tx_clone_deferred) {
1331	skb_cb->tx_clone_deferred = 1;
1332	memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1333	}
1334
1335	skb_cb->tx_clone_ctx.rx = rx;
1336	if (++skb_cb->tx_clone_ctx.recurs > 2)
1337	return NULL;
1338
1339	/* Pick one TX key */
1340	spin_lock(lock: &tx->lock);
1341	if (tx_key == KEY_MASTER) {
1342	aead = tipc_aead_rcu_ptr(tx->aead[KEY_MASTER], &tx->lock);
1343	goto done;
1344	}
1345	do {
1346	k = (i == 0) ? key.pending :
1347	((i == 1) ? key.active : key.passive);
1348	if (!k)
1349	continue;
1350	aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock);
1351	if (!aead)
1352	continue;
1353	if (aead->mode != CLUSTER_KEY ||
1354	aead == skb_cb->tx_clone_ctx.last) {
1355	aead = NULL;
1356	continue;
1357	}
1358	/* Ok, found one cluster key */
1359	skb_cb->tx_clone_ctx.last = aead;
1360	WARN_ON(skb->next);
1361	skb->next = skb_clone(skb, GFP_ATOMIC);
1362	if (unlikely(!skb->next))
1363	pr_warn("Failed to clone skb for next round if any\n");
1364	break;
1365	} while (++i < 3);
1366
1367	done:
1368	if (likely(aead))
1369	WARN_ON(!refcount_inc_not_zero(&aead->refcnt));
1370	spin_unlock(lock: &tx->lock);
1371
1372	return aead;
1373	}
1374
1375	/**
1376	* tipc_crypto_key_synch: Synch own key data according to peer key status
1377	* @rx: RX crypto handle
1378	* @skb: TIPCv2 message buffer (incl. the ehdr from peer)
1379	*
1380	* This function updates the peer node related data as the peer RX active key
1381	* has changed, so the number of TX keys' users on this node are increased and
1382	* decreased correspondingly.
1383	*
1384	* It also considers if peer has no key, then we need to make own master key
1385	* (if any) taking over i.e. starting grace period and also trigger key
1386	* distributing process.
1387	*
1388	* The "per-peer" sndnxt is also reset when the peer key has switched.
1389	*/
1390	static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb)
1391	{
1392	struct tipc_ehdr *ehdr = (struct tipc_ehdr *)skb_network_header(skb);
1393	struct tipc_crypto *tx = tipc_net(net: rx->net)->crypto_tx;
1394	struct tipc_msg *hdr = buf_msg(skb);
1395	u32 self = tipc_own_addr(net: rx->net);
1396	u8 cur, new;
1397	unsigned long delay;
1398
1399	/* Update RX 'key_master' flag according to peer, also mark "legacy" if
1400	* a peer has no master key.
1401	*/
1402	rx->key_master = ehdr->master_key;
1403	if (!rx->key_master)
1404	tx->legacy_user = 1;
1405
1406	/* For later cases, apply only if message is destined to this node */
1407	if (!ehdr->destined || msg_short(m: hdr) || msg_destnode(m: hdr) != self)
1408	return;
1409
1410	/* Case 1: Peer has no keys, let's make master key take over */
1411	if (ehdr->rx_nokey) {
1412	/* Set or extend grace period */
1413	tx->timer2 = jiffies;
1414	/* Schedule key distributing for the peer if not yet */
1415	if (tx->key.keys &&
1416	!atomic_cmpxchg(v: &rx->key_distr, old: 0, KEY_DISTR_SCHED)) {
1417	get_random_bytes(buf: &delay, len: 2);
1418	delay %= 5;
1419	delay = msecs_to_jiffies(m: 500 * ++delay);
1420	if (queue_delayed_work(wq: tx->wq, dwork: &rx->work, delay))
1421	tipc_node_get(node: rx->node);
1422	}
1423	} else {
1424	/* Cancel a pending key distributing if any */
1425	atomic_xchg(v: &rx->key_distr, new: 0);
1426	}
1427
1428	/* Case 2: Peer RX active key has changed, let's update own TX users */
1429	cur = atomic_read(v: &rx->peer_rx_active);
1430	new = ehdr->rx_key_active;
1431	if (tx->key.keys &&
1432	cur != new &&
1433	atomic_cmpxchg(v: &rx->peer_rx_active, old: cur, new) == cur) {
1434	if (new)
1435	tipc_aead_users_inc(aead: tx->aead[new], INT_MAX);
1436	if (cur)
1437	tipc_aead_users_dec(aead: tx->aead[cur], lim: 0);
1438
1439	atomic64_set(v: &rx->sndnxt, i: 0);
1440	/* Mark the point TX key users changed */
1441	tx->timer1 = jiffies;
1442
1443	pr_debug("%s: key users changed %d-- %d++, peer %s\n",
1444	tx->name, cur, new, rx->name);
1445	}
1446	}
1447
1448	static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
1449	{
1450	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1451	struct tipc_key key;
1452
1453	spin_lock_bh(lock: &tx->lock);
1454	key = tx->key;
1455	WARN_ON(!key.active || tx_key != key.active);
1456
1457	/* Free the active key */
1458	tipc_crypto_key_set_state(c: tx, new_passive: key.passive, new_active: 0, new_pending: key.pending);
1459	tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1460	spin_unlock_bh(lock: &tx->lock);
1461
1462	pr_warn("%s: key is revoked\n", tx->name);
1463	return -EKEYREVOKED;
1464	}
1465
1466	int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
1467	struct tipc_node *node)
1468	{
1469	struct tipc_crypto *c;
1470
1471	if (*crypto)
1472	return -EEXIST;
1473
1474	/* Allocate crypto */
1475	c = kzalloc(sizeof(*c), GFP_ATOMIC);
1476	if (!c)
1477	return -ENOMEM;
1478
1479	/* Allocate workqueue on TX */
1480	if (!node) {
1481	c->wq = alloc_ordered_workqueue("tipc_crypto", 0);
1482	if (!c->wq) {
1483	kfree(objp: c);
1484	return -ENOMEM;
1485	}
1486	}
1487
1488	/* Allocate statistic structure */
1489	c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
1490	if (!c->stats) {
1491	if (c->wq)
1492	destroy_workqueue(wq: c->wq);
1493	kfree_sensitive(objp: c);
1494	return -ENOMEM;
1495	}
1496
1497	c->flags = 0;
1498	c->net = net;
1499	c->node = node;
1500	get_random_bytes(buf: &c->key_gen, len: 2);
1501	tipc_crypto_key_set_state(c, new_passive: 0, new_active: 0, new_pending: 0);
1502	atomic_set(v: &c->key_distr, i: 0);
1503	atomic_set(v: &c->peer_rx_active, i: 0);
1504	atomic64_set(v: &c->sndnxt, i: 0);
1505	c->timer1 = jiffies;
1506	c->timer2 = jiffies;
1507	c->rekeying_intv = TIPC_REKEYING_INTV_DEF;
1508	spin_lock_init(&c->lock);
1509	scnprintf(buf: c->name, size: 48, fmt: "%s(%s)", (is_rx(c)) ? "RX" : "TX",
1510	(is_rx(c)) ? tipc_node_get_id_str(node: c->node) :
1511	tipc_own_id_string(net: c->net));
1512
1513	if (is_rx(c))
1514	INIT_DELAYED_WORK(&c->work, tipc_crypto_work_rx);
1515	else
1516	INIT_DELAYED_WORK(&c->work, tipc_crypto_work_tx);
1517
1518	*crypto = c;
1519	return 0;
1520	}
1521
1522	void tipc_crypto_stop(struct tipc_crypto **crypto)
1523	{
1524	struct tipc_crypto *c = *crypto;
1525	u8 k;
1526
1527	if (!c)
1528	return;
1529
1530	/* Flush any queued works & destroy wq */
1531	if (is_tx(c)) {
1532	c->rekeying_intv = 0;
1533	cancel_delayed_work_sync(dwork: &c->work);
1534	destroy_workqueue(wq: c->wq);
1535	}
1536
1537	/* Release AEAD keys */
1538	rcu_read_lock();
1539	for (k = KEY_MIN; k <= KEY_MAX; k++)
1540	tipc_aead_put(rcu_dereference(c->aead[k]));
1541	rcu_read_unlock();
1542	pr_debug("%s: has been stopped\n", c->name);
1543
1544	/* Free this crypto statistics */
1545	free_percpu(pdata: c->stats);
1546
1547	*crypto = NULL;
1548	kfree_sensitive(objp: c);
1549	}
1550
1551	void tipc_crypto_timeout(struct tipc_crypto *rx)
1552	{
1553	struct tipc_net *tn = tipc_net(net: rx->net);
1554	struct tipc_crypto *tx = tn->crypto_tx;
1555	struct tipc_key key;
1556	int cmd;
1557
1558	/* TX pending: taking all users & stable -> active */
1559	spin_lock(lock: &tx->lock);
1560	key = tx->key;
1561	if (key.active && tipc_aead_users(aead: tx->aead[key.active]) > 0)
1562	goto s1;
1563	if (!key.pending || tipc_aead_users(aead: tx->aead[key.pending]) <= 0)
1564	goto s1;
1565	if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_TIME))
1566	goto s1;
1567
1568	tipc_crypto_key_set_state(c: tx, new_passive: key.passive, new_active: key.pending, new_pending: 0);
1569	if (key.active)
1570	tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
1571	this_cpu_inc(tx->stats->stat[STAT_SWITCHES]);
1572	pr_info("%s: key[%d] is activated\n", tx->name, key.pending);
1573
1574	s1:
1575	spin_unlock(lock: &tx->lock);
1576
1577	/* RX pending: having user -> active */
1578	spin_lock(lock: &rx->lock);
1579	key = rx->key;
1580	if (!key.pending || tipc_aead_users(aead: rx->aead[key.pending]) <= 0)
1581	goto s2;
1582
1583	if (key.active)
1584	key.passive = key.active;
1585	key.active = key.pending;
1586	rx->timer2 = jiffies;
1587	tipc_crypto_key_set_state(c: rx, new_passive: key.passive, new_active: key.active, new_pending: 0);
1588	this_cpu_inc(rx->stats->stat[STAT_SWITCHES]);
1589	pr_info("%s: key[%d] is activated\n", rx->name, key.pending);
1590	goto s5;
1591
1592	s2:
1593	/* RX pending: not working -> remove */
1594	if (!key.pending || tipc_aead_users(aead: rx->aead[key.pending]) > -10)
1595	goto s3;
1596
1597	tipc_crypto_key_set_state(c: rx, new_passive: key.passive, new_active: key.active, new_pending: 0);
1598	tipc_crypto_key_detach(rx->aead[key.pending], &rx->lock);
1599	pr_debug("%s: key[%d] is removed\n", rx->name, key.pending);
1600	goto s5;
1601
1602	s3:
1603	/* RX active: timed out or no user -> pending */
1604	if (!key.active)
1605	goto s4;
1606	if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM) &&
1607	tipc_aead_users(aead: rx->aead[key.active]) > 0)
1608	goto s4;
1609
1610	if (key.pending)
1611	key.passive = key.active;
1612	else
1613	key.pending = key.active;
1614	rx->timer2 = jiffies;
1615	tipc_crypto_key_set_state(c: rx, new_passive: key.passive, new_active: 0, new_pending: key.pending);
1616	tipc_aead_users_set(aead: rx->aead[key.pending], val: 0);
1617	pr_debug("%s: key[%d] is deactivated\n", rx->name, key.active);
1618	goto s5;
1619
1620	s4:
1621	/* RX passive: outdated or not working -> free */
1622	if (!key.passive)
1623	goto s5;
1624	if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM) &&
1625	tipc_aead_users(aead: rx->aead[key.passive]) > -10)
1626	goto s5;
1627
1628	tipc_crypto_key_set_state(c: rx, new_passive: 0, new_active: key.active, new_pending: key.pending);
1629	tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock);
1630	pr_debug("%s: key[%d] is freed\n", rx->name, key.passive);
1631
1632	s5:
1633	spin_unlock(lock: &rx->lock);
1634
1635	/* Relax it here, the flag will be set again if it really is, but only
1636	* when we are not in grace period for safety!
1637	*/
1638	if (time_after(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD))
1639	tx->legacy_user = 0;
1640
1641	/* Limit max_tfms & do debug commands if needed */
1642	if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM))
1643	return;
1644
1645	cmd = sysctl_tipc_max_tfms;
1646	sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF;
1647	tipc_crypto_do_cmd(net: rx->net, cmd);
1648	}
1649
1650	static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
1651	struct tipc_bearer *b,
1652	struct tipc_media_addr *dst,
1653	struct tipc_node *__dnode, u8 type)
1654	{
1655	struct sk_buff *skb;
1656
1657	skb = skb_clone(skb: _skb, GFP_ATOMIC);
1658	if (skb) {
1659	TIPC_SKB_CB(skb)->xmit_type = type;
1660	tipc_crypto_xmit(net, skb: &skb, b, dst, __dnode);
1661	if (skb)
1662	b->media->send_msg(net, skb, b, dst);
1663	}
1664	}
1665
1666	/**
1667	* tipc_crypto_xmit - Build & encrypt TIPC message for xmit
1668	* @net: struct net
1669	* @skb: input/output message skb pointer
1670	* @b: bearer used for xmit later
1671	* @dst: destination media address
1672	* @__dnode: destination node for reference if any
1673	*
1674	* First, build an encryption message header on the top of the message, then
1675	* encrypt the original TIPC message by using the pending, master or active
1676	* key with this preference order.
1677	* If the encryption is successful, the encrypted skb is returned directly or
1678	* via the callback.
1679	* Otherwise, the skb is freed!
1680	*
1681	* Return:
1682	* * 0 : the encryption has succeeded (or no encryption)
1683	* * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made
1684	* * -ENOKEK : the encryption has failed due to no key
1685	* * -EKEYREVOKED : the encryption has failed due to key revoked
1686	* * -ENOMEM : the encryption has failed due to no memory
1687	* * < 0 : the encryption has failed due to other reasons
1688	*/
1689	int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
1690	struct tipc_bearer *b, struct tipc_media_addr *dst,
1691	struct tipc_node *__dnode)
1692	{
1693	struct tipc_crypto *__rx = tipc_node_crypto_rx(n: __dnode);
1694	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1695	struct tipc_crypto_stats __percpu *stats = tx->stats;
1696	struct tipc_msg *hdr = buf_msg(skb: *skb);
1697	struct tipc_key key = tx->key;
1698	struct tipc_aead *aead = NULL;
1699	u32 user = msg_user(m: hdr);
1700	u32 type = msg_type(m: hdr);
1701	int rc = -ENOKEY;
1702	u8 tx_key = 0;
1703
1704	/* No encryption? */
1705	if (!tx->working)
1706	return 0;
1707
1708	/* Pending key if peer has active on it or probing time */
1709	if (unlikely(key.pending)) {
1710	tx_key = key.pending;
1711	if (!tx->key_master && !key.active)
1712	goto encrypt;
1713	if (__rx && atomic_read(v: &__rx->peer_rx_active) == tx_key)
1714	goto encrypt;
1715	if (TIPC_SKB_CB(*skb)->xmit_type == SKB_PROBING) {
1716	pr_debug("%s: probing for key[%d]\n", tx->name,
1717	key.pending);
1718	goto encrypt;
1719	}
1720	if (user == LINK_CONFIG || user == LINK_PROTOCOL)
1721	tipc_crypto_clone_msg(net, skb: *skb, b, dst, __dnode,
1722	SKB_PROBING);
1723	}
1724
1725	/* Master key if this is a *vital* message or in grace period */
1726	if (tx->key_master) {
1727	tx_key = KEY_MASTER;
1728	if (!key.active)
1729	goto encrypt;
1730	if (TIPC_SKB_CB(*skb)->xmit_type == SKB_GRACING) {
1731	pr_debug("%s: gracing for msg (%d %d)\n", tx->name,
1732	user, type);
1733	goto encrypt;
1734	}
1735	if (user == LINK_CONFIG ||
1736	(user == LINK_PROTOCOL && type == RESET_MSG) ||
1737	(user == MSG_CRYPTO && type == KEY_DISTR_MSG) ||
1738	time_before(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) {
1739	if (__rx && __rx->key_master &&
1740	!atomic_read(v: &__rx->peer_rx_active))
1741	goto encrypt;
1742	if (!__rx) {
1743	if (likely(!tx->legacy_user))
1744	goto encrypt;
1745	tipc_crypto_clone_msg(net, skb: *skb, b, dst,
1746	__dnode, SKB_GRACING);
1747	}
1748	}
1749	}
1750
1751	/* Else, use the active key if any */
1752	if (likely(key.active)) {
1753	tx_key = key.active;
1754	goto encrypt;
1755	}
1756
1757	goto exit;
1758
1759	encrypt:
1760	aead = tipc_aead_get(aead: tx->aead[tx_key]);
1761	if (unlikely(!aead))
1762	goto exit;
1763	rc = tipc_ehdr_build(net, aead, tx_key, skb: *skb, __rx);
1764	if (likely(rc > 0))
1765	rc = tipc_aead_encrypt(aead, skb: *skb, b, dst, __dnode);
1766
1767	exit:
1768	switch (rc) {
1769	case 0:
1770	this_cpu_inc(stats->stat[STAT_OK]);
1771	break;
1772	case -EINPROGRESS:
1773	case -EBUSY:
1774	this_cpu_inc(stats->stat[STAT_ASYNC]);
1775	*skb = NULL;
1776	return rc;
1777	default:
1778	this_cpu_inc(stats->stat[STAT_NOK]);
1779	if (rc == -ENOKEY)
1780	this_cpu_inc(stats->stat[STAT_NOKEYS]);
1781	else if (rc == -EKEYREVOKED)
1782	this_cpu_inc(stats->stat[STAT_BADKEYS]);
1783	kfree_skb(skb: *skb);
1784	*skb = NULL;
1785	break;
1786	}
1787
1788	tipc_aead_put(aead);
1789	return rc;
1790	}
1791
1792	/**
1793	* tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer
1794	* @net: struct net
1795	* @rx: RX crypto handle
1796	* @skb: input/output message skb pointer
1797	* @b: bearer where the message has been received
1798	*
1799	* If the decryption is successful, the decrypted skb is returned directly or
1800	* as the callback, the encryption header and auth tag will be trimmed out
1801	* before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete().
1802	* Otherwise, the skb will be freed!
1803	* Note: RX key(s) can be re-aligned, or in case of no key suitable, TX
1804	* cluster key(s) can be taken for decryption (- recursive).
1805	*
1806	* Return:
1807	* * 0 : the decryption has successfully completed
1808	* * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made
1809	* * -ENOKEY : the decryption has failed due to no key
1810	* * -EBADMSG : the decryption has failed due to bad message
1811	* * -ENOMEM : the decryption has failed due to no memory
1812	* * < 0 : the decryption has failed due to other reasons
1813	*/
1814	int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
1815	struct sk_buff **skb, struct tipc_bearer *b)
1816	{
1817	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
1818	struct tipc_crypto_stats __percpu *stats;
1819	struct tipc_aead *aead = NULL;
1820	struct tipc_key key;
1821	int rc = -ENOKEY;
1822	u8 tx_key, n;
1823
1824	tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key;
1825
1826	/* New peer?
1827	* Let's try with TX key (i.e. cluster mode) & verify the skb first!
1828	*/
1829	if (unlikely(!rx || tx_key == KEY_MASTER))
1830	goto pick_tx;
1831
1832	/* Pick RX key according to TX key if any */
1833	key = rx->key;
1834	if (tx_key == key.active || tx_key == key.pending ||
1835	tx_key == key.passive)
1836	goto decrypt;
1837
1838	/* Unknown key, let's try to align RX key(s) */
1839	if (tipc_crypto_key_try_align(rx, new_pending: tx_key))
1840	goto decrypt;
1841
1842	pick_tx:
1843	/* No key suitable? Try to pick one from TX... */
1844	aead = tipc_crypto_key_pick_tx(tx, rx, skb: *skb, tx_key);
1845	if (aead)
1846	goto decrypt;
1847	goto exit;
1848
1849	decrypt:
1850	rcu_read_lock();
1851	if (!aead)
1852	aead = tipc_aead_get(aead: rx->aead[tx_key]);
1853	rc = tipc_aead_decrypt(net, aead, skb: *skb, b);
1854	rcu_read_unlock();
1855
1856	exit:
1857	stats = ((rx) ?: tx)->stats;
1858	switch (rc) {
1859	case 0:
1860	this_cpu_inc(stats->stat[STAT_OK]);
1861	break;
1862	case -EINPROGRESS:
1863	case -EBUSY:
1864	this_cpu_inc(stats->stat[STAT_ASYNC]);
1865	*skb = NULL;
1866	return rc;
1867	default:
1868	this_cpu_inc(stats->stat[STAT_NOK]);
1869	if (rc == -ENOKEY) {
1870	kfree_skb(skb: *skb);
1871	*skb = NULL;
1872	if (rx) {
1873	/* Mark rx->nokey only if we dont have a
1874	* pending received session key, nor a newer
1875	* one i.e. in the next slot.
1876	*/
1877	n = key_next(tx_key);
1878	rx->nokey = !(rx->skey ||
1879	rcu_access_pointer(rx->aead[n]));
1880	pr_debug_ratelimited("%s: nokey %d, key %d/%x\n",
1881	rx->name, rx->nokey,
1882	tx_key, rx->key.keys);
1883	tipc_node_put(node: rx->node);
1884	}
1885	this_cpu_inc(stats->stat[STAT_NOKEYS]);
1886	return rc;
1887	} else if (rc == -EBADMSG) {
1888	this_cpu_inc(stats->stat[STAT_BADMSGS]);
1889	}
1890	break;
1891	}
1892
1893	tipc_crypto_rcv_complete(net, aead, b, skb, err: rc);
1894	return rc;
1895	}
1896
1897	static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
1898	struct tipc_bearer *b,
1899	struct sk_buff **skb, int err)
1900	{
1901	struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb);
1902	struct tipc_crypto *rx = aead->crypto;
1903	struct tipc_aead *tmp = NULL;
1904	struct tipc_ehdr *ehdr;
1905	struct tipc_node *n;
1906
1907	/* Is this completed by TX? */
1908	if (unlikely(is_tx(aead->crypto))) {
1909	rx = skb_cb->tx_clone_ctx.rx;
1910	pr_debug("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n",
1911	(rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead,
1912	(*skb)->next, skb_cb->flags);
1913	pr_debug("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n",
1914	skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last,
1915	aead->crypto->aead[1], aead->crypto->aead[2],
1916	aead->crypto->aead[3]);
1917	if (unlikely(err)) {
1918	if (err == -EBADMSG && (*skb)->next)
1919	tipc_rcv(net, skb: (*skb)->next, b);
1920	goto free_skb;
1921	}
1922
1923	if (likely((*skb)->next)) {
1924	kfree_skb(skb: (*skb)->next);
1925	(*skb)->next = NULL;
1926	}
1927	ehdr = (struct tipc_ehdr *)(*skb)->data;
1928	if (!rx) {
1929	WARN_ON(ehdr->user != LINK_CONFIG);
1930	n = tipc_node_create(net, addr: 0, peer_id: ehdr->id, capabilities: 0xffffu, hash_mixes: 0,
1931	preliminary: true);
1932	rx = tipc_node_crypto_rx(n: n);
1933	if (unlikely(!rx))
1934	goto free_skb;
1935	}
1936
1937	/* Ignore cloning if it was TX master key */
1938	if (ehdr->tx_key == KEY_MASTER)
1939	goto rcv;
1940	if (tipc_aead_clone(dst: &tmp, src: aead) < 0)
1941	goto rcv;
1942	WARN_ON(!refcount_inc_not_zero(&tmp->refcnt));
1943	if (tipc_crypto_key_attach(c: rx, aead: tmp, pos: ehdr->tx_key, master_key: false) < 0) {
1944	tipc_aead_free(rp: &tmp->rcu);
1945	goto rcv;
1946	}
1947	tipc_aead_put(aead);
1948	aead = tmp;
1949	}
1950
1951	if (unlikely(err)) {
1952	tipc_aead_users_dec(aead: (struct tipc_aead __force __rcu *)aead, INT_MIN);
1953	goto free_skb;
1954	}
1955
1956	/* Set the RX key's user */
1957	tipc_aead_users_set(aead: (struct tipc_aead __force __rcu *)aead, val: 1);
1958
1959	/* Mark this point, RX works */
1960	rx->timer1 = jiffies;
1961
1962	rcv:
1963	/* Remove ehdr & auth. tag prior to tipc_rcv() */
1964	ehdr = (struct tipc_ehdr *)(*skb)->data;
1965
1966	/* Mark this point, RX passive still works */
1967	if (rx->key.passive && ehdr->tx_key == rx->key.passive)
1968	rx->timer2 = jiffies;
1969
1970	skb_reset_network_header(skb: *skb);
1971	skb_pull(skb: *skb, len: tipc_ehdr_size(ehdr));
1972	if (pskb_trim(skb: *skb, len: (*skb)->len - aead->authsize))
1973	goto free_skb;
1974
1975	/* Validate TIPCv2 message */
1976	if (unlikely(!tipc_msg_validate(skb))) {
1977	pr_err_ratelimited("Packet dropped after decryption!\n");
1978	goto free_skb;
1979	}
1980
1981	/* Ok, everything's fine, try to synch own keys according to peers' */
1982	tipc_crypto_key_synch(rx, skb: *skb);
1983
1984	/* Re-fetch skb cb as skb might be changed in tipc_msg_validate */
1985	skb_cb = TIPC_SKB_CB(*skb);
1986
1987	/* Mark skb decrypted */
1988	skb_cb->decrypted = 1;
1989
1990	/* Clear clone cxt if any */
1991	if (likely(!skb_cb->tx_clone_deferred))
1992	goto exit;
1993	skb_cb->tx_clone_deferred = 0;
1994	memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
1995	goto exit;
1996
1997	free_skb:
1998	kfree_skb(skb: *skb);
1999	*skb = NULL;
2000
2001	exit:
2002	tipc_aead_put(aead);
2003	if (rx)
2004	tipc_node_put(node: rx->node);
2005	}
2006
2007	static void tipc_crypto_do_cmd(struct net *net, int cmd)
2008	{
2009	struct tipc_net *tn = tipc_net(net);
2010	struct tipc_crypto *tx = tn->crypto_tx, *rx;
2011	struct list_head *p;
2012	unsigned int stat;
2013	int i, j, cpu;
2014	char buf[200];
2015
2016	/* Currently only one command is supported */
2017	switch (cmd) {
2018	case 0xfff1:
2019	goto print_stats;
2020	default:
2021	return;
2022	}
2023
2024	print_stats:
2025	/* Print a header */
2026	pr_info("\n=============== TIPC Crypto Statistics ===============\n\n");
2027
2028	/* Print key status */
2029	pr_info("Key status:\n");
2030	pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net),
2031	tipc_crypto_key_dump(tx, buf));
2032
2033	rcu_read_lock();
2034	for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2035	rx = tipc_node_crypto_rx_by_list(pos: p);
2036	pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node),
2037	tipc_crypto_key_dump(rx, buf));
2038	}
2039	rcu_read_unlock();
2040
2041	/* Print crypto statistics */
2042	for (i = 0, j = 0; i < MAX_STATS; i++)
2043	j += scnprintf(buf: buf + j, size: 200 - j, fmt: "|%11s ", hstats[i]);
2044	pr_info("Counter %s", buf);
2045
2046	memset(buf, '-', 115);
2047	buf[115] = '\0';
2048	pr_info("%s\n", buf);
2049
2050	j = scnprintf(buf, size: 200, fmt: "TX(%7.7s) ", tipc_own_id_string(net));
2051	for_each_possible_cpu(cpu) {
2052	for (i = 0; i < MAX_STATS; i++) {
2053	stat = per_cpu_ptr(tx->stats, cpu)->stat[i];
2054	j += scnprintf(buf: buf + j, size: 200 - j, fmt: "|%11d ", stat);
2055	}
2056	pr_info("%s", buf);
2057	j = scnprintf(buf, size: 200, fmt: "%12s", " ");
2058	}
2059
2060	rcu_read_lock();
2061	for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
2062	rx = tipc_node_crypto_rx_by_list(pos: p);
2063	j = scnprintf(buf, size: 200, fmt: "RX(%7.7s) ",
2064	tipc_node_get_id_str(node: rx->node));
2065	for_each_possible_cpu(cpu) {
2066	for (i = 0; i < MAX_STATS; i++) {
2067	stat = per_cpu_ptr(rx->stats, cpu)->stat[i];
2068	j += scnprintf(buf: buf + j, size: 200 - j, fmt: "|%11d ",
2069	stat);
2070	}
2071	pr_info("%s", buf);
2072	j = scnprintf(buf, size: 200, fmt: "%12s", " ");
2073	}
2074	}
2075	rcu_read_unlock();
2076
2077	pr_info("\n======================== Done ========================\n");
2078	}
2079
2080	static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf)
2081	{
2082	struct tipc_key key = c->key;
2083	struct tipc_aead *aead;
2084	int k, i = 0;
2085	char *s;
2086
2087	for (k = KEY_MIN; k <= KEY_MAX; k++) {
2088	if (k == KEY_MASTER) {
2089	if (is_rx(c))
2090	continue;
2091	if (time_before(jiffies,
2092	c->timer2 + TIPC_TX_GRACE_PERIOD))
2093	s = "ACT";
2094	else
2095	s = "PAS";
2096	} else {
2097	if (k == key.passive)
2098	s = "PAS";
2099	else if (k == key.active)
2100	s = "ACT";
2101	else if (k == key.pending)
2102	s = "PEN";
2103	else
2104	s = "-";
2105	}
2106	i += scnprintf(buf: buf + i, size: 200 - i, fmt: "\tKey%d: %s", k, s);
2107
2108	rcu_read_lock();
2109	aead = rcu_dereference(c->aead[k]);
2110	if (aead)
2111	i += scnprintf(buf: buf + i, size: 200 - i,
2112	fmt: "{\"0x...%s\", \"%s\"}/%d:%d",
2113	aead->hint,
2114	(aead->mode == CLUSTER_KEY) ? "c" : "p",
2115	atomic_read(v: &aead->users),
2116	refcount_read(r: &aead->refcnt));
2117	rcu_read_unlock();
2118	i += scnprintf(buf: buf + i, size: 200 - i, fmt: "\n");
2119	}
2120
2121	if (is_rx(c))
2122	i += scnprintf(buf: buf + i, size: 200 - i, fmt: "\tPeer RX active: %d\n",
2123	atomic_read(v: &c->peer_rx_active));
2124
2125	return buf;
2126	}
2127
2128	static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
2129	char *buf)
2130	{
2131	struct tipc_key *key = &old;
2132	int k, i = 0;
2133	char *s;
2134
2135	/* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */
2136	again:
2137	i += scnprintf(buf: buf + i, size: 32 - i, fmt: "[");
2138	for (k = KEY_1; k <= KEY_3; k++) {
2139	if (k == key->passive)
2140	s = "pas";
2141	else if (k == key->active)
2142	s = "act";
2143	else if (k == key->pending)
2144	s = "pen";
2145	else
2146	s = "-";
2147	i += scnprintf(buf: buf + i, size: 32 - i,
2148	fmt: (k != KEY_3) ? "%s " : "%s", s);
2149	}
2150	if (key != &new) {
2151	i += scnprintf(buf: buf + i, size: 32 - i, fmt: "] -> ");
2152	key = &new;
2153	goto again;
2154	}
2155	i += scnprintf(buf: buf + i, size: 32 - i, fmt: "]");
2156	return buf;
2157	}
2158
2159	/**
2160	* tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point
2161	* @net: the struct net
2162	* @skb: the receiving message buffer
2163	*/
2164	void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb)
2165	{
2166	struct tipc_crypto *rx;
2167	struct tipc_msg *hdr;
2168
2169	if (unlikely(skb_linearize(skb)))
2170	goto exit;
2171
2172	hdr = buf_msg(skb);
2173	rx = tipc_node_crypto_rx_by_addr(net, addr: msg_prevnode(m: hdr));
2174	if (unlikely(!rx))
2175	goto exit;
2176
2177	switch (msg_type(m: hdr)) {
2178	case KEY_DISTR_MSG:
2179	if (tipc_crypto_key_rcv(rx, hdr))
2180	goto exit;
2181	break;
2182	default:
2183	break;
2184	}
2185
2186	tipc_node_put(node: rx->node);
2187
2188	exit:
2189	kfree_skb(skb);
2190	}
2191
2192	/**
2193	* tipc_crypto_key_distr - Distribute a TX key
2194	* @tx: the TX crypto
2195	* @key: the key's index
2196	* @dest: the destination tipc node, = NULL if distributing to all nodes
2197	*
2198	* Return: 0 in case of success, otherwise < 0
2199	*/
2200	int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key,
2201	struct tipc_node *dest)
2202	{
2203	struct tipc_aead *aead;
2204	u32 dnode = tipc_node_get_addr(node: dest);
2205	int rc = -ENOKEY;
2206
2207	if (!sysctl_tipc_key_exchange_enabled)
2208	return 0;
2209
2210	if (key) {
2211	rcu_read_lock();
2212	aead = tipc_aead_get(aead: tx->aead[key]);
2213	if (likely(aead)) {
2214	rc = tipc_crypto_key_xmit(net: tx->net, skey: aead->key,
2215	gen: aead->gen, mode: aead->mode,
2216	dnode);
2217	tipc_aead_put(aead);
2218	}
2219	rcu_read_unlock();
2220	}
2221
2222	return rc;
2223	}
2224
2225	/**
2226	* tipc_crypto_key_xmit - Send a session key
2227	* @net: the struct net
2228	* @skey: the session key to be sent
2229	* @gen: the key's generation
2230	* @mode: the key's mode
2231	* @dnode: the destination node address, = 0 if broadcasting to all nodes
2232	*
2233	* The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG'
2234	* as its data section, then xmit-ed through the uc/bc link.
2235	*
2236	* Return: 0 in case of success, otherwise < 0
2237	*/
2238	static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
2239	u16 gen, u8 mode, u32 dnode)
2240	{
2241	struct sk_buff_head pkts;
2242	struct tipc_msg *hdr;
2243	struct sk_buff *skb;
2244	u16 size, cong_link_cnt;
2245	u8 *data;
2246	int rc;
2247
2248	size = tipc_aead_key_size(key: skey);
2249	skb = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
2250	if (!skb)
2251	return -ENOMEM;
2252
2253	hdr = buf_msg(skb);
2254	tipc_msg_init(own_addr: tipc_own_addr(net), m: hdr, MSG_CRYPTO, KEY_DISTR_MSG,
2255	INT_H_SIZE, destnode: dnode);
2256	msg_set_size(m: hdr, INT_H_SIZE + size);
2257	msg_set_key_gen(m: hdr, gen);
2258	msg_set_key_mode(m: hdr, mode);
2259
2260	data = msg_data(m: hdr);
2261	*((__be32 *)(data + TIPC_AEAD_ALG_NAME)) = htonl(skey->keylen);
2262	memcpy(data, skey->alg_name, TIPC_AEAD_ALG_NAME);
2263	memcpy(data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->key,
2264	skey->keylen);
2265
2266	__skb_queue_head_init(list: &pkts);
2267	__skb_queue_tail(list: &pkts, newsk: skb);
2268	if (dnode)
2269	rc = tipc_node_xmit(net, list: &pkts, dnode, selector: 0);
2270	else
2271	rc = tipc_bcast_xmit(net, pkts: &pkts, cong_link_cnt: &cong_link_cnt);
2272
2273	return rc;
2274	}
2275
2276	/**
2277	* tipc_crypto_key_rcv - Receive a session key
2278	* @rx: the RX crypto
2279	* @hdr: the TIPC v2 message incl. the receiving session key in its data
2280	*
2281	* This function retrieves the session key in the message from peer, then
2282	* schedules a RX work to attach the key to the corresponding RX crypto.
2283	*
2284	* Return: "true" if the key has been scheduled for attaching, otherwise
2285	* "false".
2286	*/
2287	static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr)
2288	{
2289	struct tipc_crypto *tx = tipc_net(net: rx->net)->crypto_tx;
2290	struct tipc_aead_key *skey = NULL;
2291	u16 key_gen = msg_key_gen(m: hdr);
2292	u32 size = msg_data_sz(m: hdr);
2293	u8 *data = msg_data(m: hdr);
2294	unsigned int keylen;
2295
2296	/* Verify whether the size can exist in the packet */
2297	if (unlikely(size < sizeof(struct tipc_aead_key) + TIPC_AEAD_KEYLEN_MIN)) {
2298	pr_debug("%s: message data size is too small\n", rx->name);
2299	goto exit;
2300	}
2301
2302	keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME)));
2303
2304	/* Verify the supplied size values */
2305	if (unlikely(keylen > TIPC_AEAD_KEY_SIZE_MAX ||
2306	size != keylen + sizeof(struct tipc_aead_key))) {
2307	pr_debug("%s: invalid MSG_CRYPTO key size\n", rx->name);
2308	goto exit;
2309	}
2310
2311	spin_lock(lock: &rx->lock);
2312	if (unlikely(rx->skey || (key_gen == rx->key_gen && rx->key.keys))) {
2313	pr_err("%s: key existed <%p>, gen %d vs %d\n", rx->name,
2314	rx->skey, key_gen, rx->key_gen);
2315	goto exit_unlock;
2316	}
2317
2318	/* Allocate memory for the key */
2319	skey = kmalloc(size, GFP_ATOMIC);
2320	if (unlikely(!skey)) {
2321	pr_err("%s: unable to allocate memory for skey\n", rx->name);
2322	goto exit_unlock;
2323	}
2324
2325	/* Copy key from msg data */
2326	skey->keylen = keylen;
2327	memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME);
2328	memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32),
2329	skey->keylen);
2330
2331	rx->key_gen = key_gen;
2332	rx->skey_mode = msg_key_mode(m: hdr);
2333	rx->skey = skey;
2334	rx->nokey = 0;
2335	mb(); /* for nokey flag */
2336
2337	exit_unlock:
2338	spin_unlock(lock: &rx->lock);
2339
2340	exit:
2341	/* Schedule the key attaching on this crypto */
2342	if (likely(skey && queue_delayed_work(tx->wq, &rx->work, 0)))
2343	return true;
2344
2345	return false;
2346	}
2347
2348	/**
2349	* tipc_crypto_work_rx - Scheduled RX works handler
2350	* @work: the struct RX work
2351	*
2352	* The function processes the previous scheduled works i.e. distributing TX key
2353	* or attaching a received session key on RX crypto.
2354	*/
2355	static void tipc_crypto_work_rx(struct work_struct *work)
2356	{
2357	struct delayed_work *dwork = to_delayed_work(work);
2358	struct tipc_crypto *rx = container_of(dwork, struct tipc_crypto, work);
2359	struct tipc_crypto *tx = tipc_net(net: rx->net)->crypto_tx;
2360	unsigned long delay = msecs_to_jiffies(m: 5000);
2361	bool resched = false;
2362	u8 key;
2363	int rc;
2364
2365	/* Case 1: Distribute TX key to peer if scheduled */
2366	if (atomic_cmpxchg(v: &rx->key_distr,
2367	KEY_DISTR_SCHED,
2368	KEY_DISTR_COMPL) == KEY_DISTR_SCHED) {
2369	/* Always pick the newest one for distributing */
2370	key = tx->key.pending ?: tx->key.active;
2371	rc = tipc_crypto_key_distr(tx, key, dest: rx->node);
2372	if (unlikely(rc))
2373	pr_warn("%s: unable to distr key[%d] to %s, err %d\n",
2374	tx->name, key, tipc_node_get_id_str(rx->node),
2375	rc);
2376
2377	/* Sched for key_distr releasing */
2378	resched = true;
2379	} else {
2380	atomic_cmpxchg(v: &rx->key_distr, KEY_DISTR_COMPL, new: 0);
2381	}
2382
2383	/* Case 2: Attach a pending received session key from peer if any */
2384	if (rx->skey) {
2385	rc = tipc_crypto_key_init(c: rx, ukey: rx->skey, mode: rx->skey_mode, master_key: false);
2386	if (unlikely(rc < 0))
2387	pr_warn("%s: unable to attach received skey, err %d\n",
2388	rx->name, rc);
2389	switch (rc) {
2390	case -EBUSY:
2391	case -ENOMEM:
2392	/* Resched the key attaching */
2393	resched = true;
2394	break;
2395	default:
2396	synchronize_rcu();
2397	kfree_sensitive(objp: rx->skey);
2398	rx->skey = NULL;
2399	break;
2400	}
2401	}
2402
2403	if (resched && queue_delayed_work(wq: tx->wq, dwork: &rx->work, delay))
2404	return;
2405
2406	tipc_node_put(node: rx->node);
2407	}
2408
2409	/**
2410	* tipc_crypto_rekeying_sched - (Re)schedule rekeying w/o new interval
2411	* @tx: TX crypto
2412	* @changed: if the rekeying needs to be rescheduled with new interval
2413	* @new_intv: new rekeying interval (when "changed" = true)
2414	*/
2415	void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed,
2416	u32 new_intv)
2417	{
2418	unsigned long delay;
2419	bool now = false;
2420
2421	if (changed) {
2422	if (new_intv == TIPC_REKEYING_NOW)
2423	now = true;
2424	else
2425	tx->rekeying_intv = new_intv;
2426	cancel_delayed_work_sync(dwork: &tx->work);
2427	}
2428
2429	if (tx->rekeying_intv || now) {
2430	delay = (now) ? 0 : tx->rekeying_intv * 60 * 1000;
2431	queue_delayed_work(wq: tx->wq, dwork: &tx->work, delay: msecs_to_jiffies(m: delay));
2432	}
2433	}
2434
2435	/**
2436	* tipc_crypto_work_tx - Scheduled TX works handler
2437	* @work: the struct TX work
2438	*
2439	* The function processes the previous scheduled work, i.e. key rekeying, by
2440	* generating a new session key based on current one, then attaching it to the
2441	* TX crypto and finally distributing it to peers. It also re-schedules the
2442	* rekeying if needed.
2443	*/
2444	static void tipc_crypto_work_tx(struct work_struct *work)
2445	{
2446	struct delayed_work *dwork = to_delayed_work(work);
2447	struct tipc_crypto *tx = container_of(dwork, struct tipc_crypto, work);
2448	struct tipc_aead_key *skey = NULL;
2449	struct tipc_key key = tx->key;
2450	struct tipc_aead *aead;
2451	int rc = -ENOMEM;
2452
2453	if (unlikely(key.pending))
2454	goto resched;
2455
2456	/* Take current key as a template */
2457	rcu_read_lock();
2458	aead = rcu_dereference(tx->aead[key.active ?: KEY_MASTER]);
2459	if (unlikely(!aead)) {
2460	rcu_read_unlock();
2461	/* At least one key should exist for securing */
2462	return;
2463	}
2464
2465	/* Lets duplicate it first */
2466	skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_ATOMIC);
2467	rcu_read_unlock();
2468
2469	/* Now, generate new key, initiate & distribute it */
2470	if (likely(skey)) {
2471	rc = tipc_aead_key_generate(skey) ?:
2472	tipc_crypto_key_init(c: tx, ukey: skey, mode: PER_NODE_KEY, master_key: false);
2473	if (likely(rc > 0))
2474	rc = tipc_crypto_key_distr(tx, key: rc, NULL);
2475	kfree_sensitive(objp: skey);
2476	}
2477
2478	if (unlikely(rc))
2479	pr_warn_ratelimited("%s: rekeying returns %d\n", tx->name, rc);
2480
2481	resched:
2482	/* Re-schedule rekeying if any */
2483	tipc_crypto_rekeying_sched(tx, changed: false, new_intv: 0);
2484	}
2485