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OpenCloudOS-Kernel/net/tipc/crypto.c

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// SPDX-License-Identifier: GPL-2.0
/**
* net/tipc/crypto.c: TIPC crypto for key handling & packet en/decryption
*
* Copyright (c) 2019, Ericsson AB
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <crypto/aead.h>
#include <crypto/aes.h>
#include <crypto/rng.h>
#include "crypto.h"
#include "msg.h"
#include "bcast.h"
#define TIPC_TX_GRACE_PERIOD msecs_to_jiffies(5000) /* 5s */
#define TIPC_TX_LASTING_TIME msecs_to_jiffies(10000) /* 10s */
#define TIPC_RX_ACTIVE_LIM msecs_to_jiffies(3000) /* 3s */
#define TIPC_RX_PASSIVE_LIM msecs_to_jiffies(15000) /* 15s */
#define TIPC_MAX_TFMS_DEF 10
#define TIPC_MAX_TFMS_LIM 1000
#define TIPC_REKEYING_INTV_DEF (60 * 24) /* default: 1 day */
/**
* TIPC Key ids
*/
enum {
KEY_MASTER = 0,
KEY_MIN = KEY_MASTER,
KEY_1 = 1,
KEY_2,
KEY_3,
KEY_MAX = KEY_3,
};
/**
* TIPC Crypto statistics
*/
enum {
STAT_OK,
STAT_NOK,
STAT_ASYNC,
STAT_ASYNC_OK,
STAT_ASYNC_NOK,
STAT_BADKEYS, /* tx only */
STAT_BADMSGS = STAT_BADKEYS, /* rx only */
STAT_NOKEYS,
STAT_SWITCHES,
MAX_STATS,
};
/* TIPC crypto statistics' header */
static const char *hstats[MAX_STATS] = {"ok", "nok", "async", "async_ok",
"async_nok", "badmsgs", "nokeys",
"switches"};
/* Max TFMs number per key */
int sysctl_tipc_max_tfms __read_mostly = TIPC_MAX_TFMS_DEF;
/* Key exchange switch, default: on */
int sysctl_tipc_key_exchange_enabled __read_mostly = 1;
/**
* struct tipc_key - TIPC keys' status indicator
*
* 7 6 5 4 3 2 1 0
* +-----+-----+-----+-----+-----+-----+-----+-----+
* key: | (reserved)|passive idx| active idx|pending idx|
* +-----+-----+-----+-----+-----+-----+-----+-----+
*/
struct tipc_key {
#define KEY_BITS (2)
#define KEY_MASK ((1 << KEY_BITS) - 1)
union {
struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
u8 pending:2,
active:2,
passive:2, /* rx only */
reserved:2;
#elif defined(__BIG_ENDIAN_BITFIELD)
u8 reserved:2,
passive:2, /* rx only */
active:2,
pending:2;
#else
#error "Please fix <asm/byteorder.h>"
#endif
} __packed;
u8 keys;
};
};
/**
* struct tipc_tfm - TIPC TFM structure to form a list of TFMs
*/
struct tipc_tfm {
struct crypto_aead *tfm;
struct list_head list;
};
/**
* struct tipc_aead - TIPC AEAD key structure
* @tfm_entry: per-cpu pointer to one entry in TFM list
* @crypto: TIPC crypto owns this key
* @cloned: reference to the source key in case cloning
* @users: the number of the key users (TX/RX)
* @salt: the key's SALT value
* @authsize: authentication tag size (max = 16)
* @mode: crypto mode is applied to the key
* @hint[]: a hint for user key
* @rcu: struct rcu_head
* @key: the aead key
* @gen: the key's generation
* @seqno: the key seqno (cluster scope)
* @refcnt: the key reference counter
*/
struct tipc_aead {
#define TIPC_AEAD_HINT_LEN (5)
struct tipc_tfm * __percpu *tfm_entry;
struct tipc_crypto *crypto;
struct tipc_aead *cloned;
atomic_t users;
u32 salt;
u8 authsize;
u8 mode;
char hint[2 * TIPC_AEAD_HINT_LEN + 1];
struct rcu_head rcu;
struct tipc_aead_key *key;
u16 gen;
atomic64_t seqno ____cacheline_aligned;
refcount_t refcnt ____cacheline_aligned;
} ____cacheline_aligned;
/**
* struct tipc_crypto_stats - TIPC Crypto statistics
*/
struct tipc_crypto_stats {
unsigned int stat[MAX_STATS];
};
/**
* struct tipc_crypto - TIPC TX/RX crypto structure
* @net: struct net
* @node: TIPC node (RX)
* @aead: array of pointers to AEAD keys for encryption/decryption
* @peer_rx_active: replicated peer RX active key index
* @key_gen: TX/RX key generation
* @key: the key states
* @skey_mode: session key's mode
* @skey: received session key
* @wq: common workqueue on TX crypto
* @work: delayed work sched for TX/RX
* @key_distr: key distributing state
* @rekeying_intv: rekeying interval (in minutes)
* @stats: the crypto statistics
* @name: the crypto name
* @sndnxt: the per-peer sndnxt (TX)
* @timer1: general timer 1 (jiffies)
* @timer2: general timer 2 (jiffies)
* @working: the crypto is working or not
* @key_master: flag indicates if master key exists
* @legacy_user: flag indicates if a peer joins w/o master key (for bwd comp.)
* @nokey: no key indication
* @lock: tipc_key lock
*/
struct tipc_crypto {
struct net *net;
struct tipc_node *node;
struct tipc_aead __rcu *aead[KEY_MAX + 1];
atomic_t peer_rx_active;
u16 key_gen;
struct tipc_key key;
u8 skey_mode;
struct tipc_aead_key *skey;
struct workqueue_struct *wq;
struct delayed_work work;
#define KEY_DISTR_SCHED 1
#define KEY_DISTR_COMPL 2
atomic_t key_distr;
u32 rekeying_intv;
struct tipc_crypto_stats __percpu *stats;
char name[48];
atomic64_t sndnxt ____cacheline_aligned;
unsigned long timer1;
unsigned long timer2;
union {
struct {
u8 working:1;
u8 key_master:1;
u8 legacy_user:1;
u8 nokey: 1;
};
u8 flags;
};
spinlock_t lock; /* crypto lock */
} ____cacheline_aligned;
/* struct tipc_crypto_tx_ctx - TX context for callbacks */
struct tipc_crypto_tx_ctx {
struct tipc_aead *aead;
struct tipc_bearer *bearer;
struct tipc_media_addr dst;
};
/* struct tipc_crypto_rx_ctx - RX context for callbacks */
struct tipc_crypto_rx_ctx {
struct tipc_aead *aead;
struct tipc_bearer *bearer;
};
static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead);
static inline void tipc_aead_put(struct tipc_aead *aead);
static void tipc_aead_free(struct rcu_head *rp);
static int tipc_aead_users(struct tipc_aead __rcu *aead);
static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim);
static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim);
static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val);
static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead);
static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
u8 mode);
static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src);
static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
unsigned int crypto_ctx_size,
u8 **iv, struct aead_request **req,
struct scatterlist **sg, int nsg);
static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
struct tipc_bearer *b,
struct tipc_media_addr *dst,
struct tipc_node *__dnode);
static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err);
static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
struct sk_buff *skb, struct tipc_bearer *b);
static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err);
static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr);
static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
u8 tx_key, struct sk_buff *skb,
struct tipc_crypto *__rx);
static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
u8 new_passive,
u8 new_active,
u8 new_pending);
static int tipc_crypto_key_attach(struct tipc_crypto *c,
struct tipc_aead *aead, u8 pos,
bool master_key);
static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending);
static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
struct tipc_crypto *rx,
struct sk_buff *skb,
u8 tx_key);
static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb);
static int tipc_crypto_key_revoke(struct net *net, u8 tx_key);
static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
struct tipc_bearer *b,
struct tipc_media_addr *dst,
struct tipc_node *__dnode, u8 type);
static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
struct tipc_bearer *b,
struct sk_buff **skb, int err);
static void tipc_crypto_do_cmd(struct net *net, int cmd);
static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf);
static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
char *buf);
static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
u16 gen, u8 mode, u32 dnode);
static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr);
static void tipc_crypto_work_tx(struct work_struct *work);
static void tipc_crypto_work_rx(struct work_struct *work);
static int tipc_aead_key_generate(struct tipc_aead_key *skey);
#define is_tx(crypto) (!(crypto)->node)
#define is_rx(crypto) (!is_tx(crypto))
#define key_next(cur) ((cur) % KEY_MAX + 1)
#define tipc_aead_rcu_ptr(rcu_ptr, lock) \
rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock))
#define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) \
do { \
typeof(rcu_ptr) __tmp = rcu_dereference_protected((rcu_ptr), \
lockdep_is_held(lock)); \
rcu_assign_pointer((rcu_ptr), (ptr)); \
tipc_aead_put(__tmp); \
} while (0)
#define tipc_crypto_key_detach(rcu_ptr, lock) \
tipc_aead_rcu_replace((rcu_ptr), NULL, lock)
/**
* tipc_aead_key_validate - Validate a AEAD user key
*/
int tipc_aead_key_validate(struct tipc_aead_key *ukey, struct genl_info *info)
{
int keylen;
/* Check if algorithm exists */
if (unlikely(!crypto_has_alg(ukey->alg_name, 0, 0))) {
GENL_SET_ERR_MSG(info, "unable to load the algorithm (module existed?)");
return -ENODEV;
}
/* Currently, we only support the "gcm(aes)" cipher algorithm */
if (strcmp(ukey->alg_name, "gcm(aes)")) {
GENL_SET_ERR_MSG(info, "not supported yet the algorithm");
return -ENOTSUPP;
}
/* Check if key size is correct */
keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
if (unlikely(keylen != TIPC_AES_GCM_KEY_SIZE_128 &&
keylen != TIPC_AES_GCM_KEY_SIZE_192 &&
keylen != TIPC_AES_GCM_KEY_SIZE_256)) {
GENL_SET_ERR_MSG(info, "incorrect key length (20, 28 or 36 octets?)");
return -EKEYREJECTED;
}
return 0;
}
/**
* tipc_aead_key_generate - Generate new session key
* @skey: input/output key with new content
*
* Return: 0 in case of success, otherwise < 0
*/
static int tipc_aead_key_generate(struct tipc_aead_key *skey)
{
int rc = 0;
/* Fill the key's content with a random value via RNG cipher */
rc = crypto_get_default_rng();
if (likely(!rc)) {
rc = crypto_rng_get_bytes(crypto_default_rng, skey->key,
skey->keylen);
crypto_put_default_rng();
}
return rc;
}
static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead)
{
struct tipc_aead *tmp;
rcu_read_lock();
tmp = rcu_dereference(aead);
if (unlikely(!tmp || !refcount_inc_not_zero(&tmp->refcnt)))
tmp = NULL;
rcu_read_unlock();
return tmp;
}
static inline void tipc_aead_put(struct tipc_aead *aead)
{
if (aead && refcount_dec_and_test(&aead->refcnt))
call_rcu(&aead->rcu, tipc_aead_free);
}
/**
* tipc_aead_free - Release AEAD key incl. all the TFMs in the list
* @rp: rcu head pointer
*/
static void tipc_aead_free(struct rcu_head *rp)
{
struct tipc_aead *aead = container_of(rp, struct tipc_aead, rcu);
struct tipc_tfm *tfm_entry, *head, *tmp;
if (aead->cloned) {
tipc_aead_put(aead->cloned);
} else {
head = *get_cpu_ptr(aead->tfm_entry);
put_cpu_ptr(aead->tfm_entry);
list_for_each_entry_safe(tfm_entry, tmp, &head->list, list) {
crypto_free_aead(tfm_entry->tfm);
list_del(&tfm_entry->list);
kfree(tfm_entry);
}
/* Free the head */
crypto_free_aead(head->tfm);
list_del(&head->list);
kfree(head);
}
free_percpu(aead->tfm_entry);
kzfree(aead->key);
kfree(aead);
}
static int tipc_aead_users(struct tipc_aead __rcu *aead)
{
struct tipc_aead *tmp;
int users = 0;
rcu_read_lock();
tmp = rcu_dereference(aead);
if (tmp)
users = atomic_read(&tmp->users);
rcu_read_unlock();
return users;
}
static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim)
{
struct tipc_aead *tmp;
rcu_read_lock();
tmp = rcu_dereference(aead);
if (tmp)
atomic_add_unless(&tmp->users, 1, lim);
rcu_read_unlock();
}
static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim)
{
struct tipc_aead *tmp;
rcu_read_lock();
tmp = rcu_dereference(aead);
if (tmp)
atomic_add_unless(&rcu_dereference(aead)->users, -1, lim);
rcu_read_unlock();
}
static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val)
{
struct tipc_aead *tmp;
int cur;
rcu_read_lock();
tmp = rcu_dereference(aead);
if (tmp) {
do {
cur = atomic_read(&tmp->users);
if (cur == val)
break;
} while (atomic_cmpxchg(&tmp->users, cur, val) != cur);
}
rcu_read_unlock();
}
/**
* tipc_aead_tfm_next - Move TFM entry to the next one in list and return it
*/
static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead)
{
struct tipc_tfm **tfm_entry;
struct crypto_aead *tfm;
tfm_entry = get_cpu_ptr(aead->tfm_entry);
*tfm_entry = list_next_entry(*tfm_entry, list);
tfm = (*tfm_entry)->tfm;
put_cpu_ptr(tfm_entry);
return tfm;
}
/**
* tipc_aead_init - Initiate TIPC AEAD
* @aead: returned new TIPC AEAD key handle pointer
* @ukey: pointer to user key data
* @mode: the key mode
*
* Allocate a (list of) new cipher transformation (TFM) with the specific user
* key data if valid. The number of the allocated TFMs can be set via the sysfs
* "net/tipc/max_tfms" first.
* Also, all the other AEAD data are also initialized.
*
* Return: 0 if the initiation is successful, otherwise: < 0
*/
static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
u8 mode)
{
struct tipc_tfm *tfm_entry, *head;
struct crypto_aead *tfm;
struct tipc_aead *tmp;
int keylen, err, cpu;
int tfm_cnt = 0;
if (unlikely(*aead))
return -EEXIST;
/* Allocate a new AEAD */
tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
if (unlikely(!tmp))
return -ENOMEM;
/* The key consists of two parts: [AES-KEY][SALT] */
keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE;
/* Allocate per-cpu TFM entry pointer */
tmp->tfm_entry = alloc_percpu(struct tipc_tfm *);
if (!tmp->tfm_entry) {
kfree_sensitive(tmp);
return -ENOMEM;
}
/* Make a list of TFMs with the user key data */
do {
tfm = crypto_alloc_aead(ukey->alg_name, 0, 0);
if (IS_ERR(tfm)) {
err = PTR_ERR(tfm);
break;
}
if (unlikely(!tfm_cnt &&
crypto_aead_ivsize(tfm) != TIPC_AES_GCM_IV_SIZE)) {
crypto_free_aead(tfm);
err = -ENOTSUPP;
break;
}
err = crypto_aead_setauthsize(tfm, TIPC_AES_GCM_TAG_SIZE);
err |= crypto_aead_setkey(tfm, ukey->key, keylen);
if (unlikely(err)) {
crypto_free_aead(tfm);
break;
}
tfm_entry = kmalloc(sizeof(*tfm_entry), GFP_KERNEL);
if (unlikely(!tfm_entry)) {
crypto_free_aead(tfm);
err = -ENOMEM;
break;
}
INIT_LIST_HEAD(&tfm_entry->list);
tfm_entry->tfm = tfm;
/* First entry? */
if (!tfm_cnt) {
head = tfm_entry;
for_each_possible_cpu(cpu) {
*per_cpu_ptr(tmp->tfm_entry, cpu) = head;
}
} else {
list_add_tail(&tfm_entry->list, &head->list);
}
} while (++tfm_cnt < sysctl_tipc_max_tfms);
/* Not any TFM is allocated? */
if (!tfm_cnt) {
free_percpu(tmp->tfm_entry);
kfree_sensitive(tmp);
return err;
}
/* Form a hex string of some last bytes as the key's hint */
bin2hex(tmp->hint, ukey->key + keylen - TIPC_AEAD_HINT_LEN,
TIPC_AEAD_HINT_LEN);
/* Initialize the other data */
tmp->mode = mode;
tmp->cloned = NULL;
tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL);
memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
atomic_set(&tmp->users, 0);
atomic64_set(&tmp->seqno, 0);
refcount_set(&tmp->refcnt, 1);
*aead = tmp;
return 0;
}
/**
* tipc_aead_clone - Clone a TIPC AEAD key
* @dst: dest key for the cloning
* @src: source key to clone from
*
* Make a "copy" of the source AEAD key data to the dest, the TFMs list is
* common for the keys.
* A reference to the source is hold in the "cloned" pointer for the later
* freeing purposes.
*
* Note: this must be done in cluster-key mode only!
* Return: 0 in case of success, otherwise < 0
*/
static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src)
{
struct tipc_aead *aead;
int cpu;
if (!src)
return -ENOKEY;
if (src->mode != CLUSTER_KEY)
return -EINVAL;
if (unlikely(*dst))
return -EEXIST;
aead = kzalloc(sizeof(*aead), GFP_ATOMIC);
if (unlikely(!aead))
return -ENOMEM;
aead->tfm_entry = alloc_percpu_gfp(struct tipc_tfm *, GFP_ATOMIC);
if (unlikely(!aead->tfm_entry)) {
kfree_sensitive(aead);
return -ENOMEM;
}
for_each_possible_cpu(cpu) {
*per_cpu_ptr(aead->tfm_entry, cpu) =
*per_cpu_ptr(src->tfm_entry, cpu);
}
memcpy(aead->hint, src->hint, sizeof(src->hint));
aead->mode = src->mode;
aead->salt = src->salt;
aead->authsize = src->authsize;
atomic_set(&aead->users, 0);
atomic64_set(&aead->seqno, 0);
refcount_set(&aead->refcnt, 1);
WARN_ON(!refcount_inc_not_zero(&src->refcnt));
aead->cloned = src;
*dst = aead;
return 0;
}
/**
* tipc_aead_mem_alloc - Allocate memory for AEAD request operations
* @tfm: cipher handle to be registered with the request
* @crypto_ctx_size: size of crypto context for callback
* @iv: returned pointer to IV data
* @req: returned pointer to AEAD request data
* @sg: returned pointer to SG lists
* @nsg: number of SG lists to be allocated
*
* Allocate memory to store the crypto context data, AEAD request, IV and SG
* lists, the memory layout is as follows:
* crypto_ctx || iv || aead_req || sg[]
*
* Return: the pointer to the memory areas in case of success, otherwise NULL
*/
static void *tipc_aead_mem_alloc(struct crypto_aead *tfm,
unsigned int crypto_ctx_size,
u8 **iv, struct aead_request **req,
struct scatterlist **sg, int nsg)
{
unsigned int iv_size, req_size;
unsigned int len;
u8 *mem;
iv_size = crypto_aead_ivsize(tfm);
req_size = sizeof(**req) + crypto_aead_reqsize(tfm);
len = crypto_ctx_size;
len += iv_size;
len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1);
len = ALIGN(len, crypto_tfm_ctx_alignment());
len += req_size;
len = ALIGN(len, __alignof__(struct scatterlist));
len += nsg * sizeof(**sg);
mem = kmalloc(len, GFP_ATOMIC);
if (!mem)
return NULL;
*iv = (u8 *)PTR_ALIGN(mem + crypto_ctx_size,
crypto_aead_alignmask(tfm) + 1);
*req = (struct aead_request *)PTR_ALIGN(*iv + iv_size,
crypto_tfm_ctx_alignment());
*sg = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
__alignof__(struct scatterlist));
return (void *)mem;
}
/**
* tipc_aead_encrypt - Encrypt a message
* @aead: TIPC AEAD key for the message encryption
* @skb: the input/output skb
* @b: TIPC bearer where the message will be delivered after the encryption
* @dst: the destination media address
* @__dnode: TIPC dest node if "known"
*
* Return:
* 0 : if the encryption has completed
* -EINPROGRESS/-EBUSY : if a callback will be performed
* < 0 : the encryption has failed
*/
static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb,
struct tipc_bearer *b,
struct tipc_media_addr *dst,
struct tipc_node *__dnode)
{
struct crypto_aead *tfm = tipc_aead_tfm_next(aead);
struct tipc_crypto_tx_ctx *tx_ctx;
struct aead_request *req;
struct sk_buff *trailer;
struct scatterlist *sg;
struct tipc_ehdr *ehdr;
int ehsz, len, tailen, nsg, rc;
void *ctx;
u32 salt;
u8 *iv;
/* Make sure message len at least 4-byte aligned */
len = ALIGN(skb->len, 4);
tailen = len - skb->len + aead->authsize;
/* Expand skb tail for authentication tag:
* As for simplicity, we'd have made sure skb having enough tailroom
* for authentication tag @skb allocation. Even when skb is nonlinear
* but there is no frag_list, it should be still fine!
* Otherwise, we must cow it to be a writable buffer with the tailroom.
*/
SKB_LINEAR_ASSERT(skb);
if (tailen > skb_tailroom(skb)) {
pr_debug("TX(): skb tailroom is not enough: %d, requires: %d\n",
skb_tailroom(skb), tailen);
}
if (unlikely(!skb_cloned(skb) && tailen <= skb_tailroom(skb))) {
nsg = 1;
trailer = skb;
} else {
/* TODO: We could avoid skb_cow_data() if skb has no frag_list
* e.g. by skb_fill_page_desc() to add another page to the skb
* with the wanted tailen... However, page skbs look not often,
* so take it easy now!
* Cloned skbs e.g. from link_xmit() seems no choice though :(
*/
nsg = skb_cow_data(skb, tailen, &trailer);
if (unlikely(nsg < 0)) {
pr_err("TX: skb_cow_data() returned %d\n", nsg);
return nsg;
}
}
pskb_put(skb, trailer, tailen);
/* Allocate memory for the AEAD operation */
ctx = tipc_aead_mem_alloc(tfm, sizeof(*tx_ctx), &iv, &req, &sg, nsg);
if (unlikely(!ctx))
return -ENOMEM;
TIPC_SKB_CB(skb)->crypto_ctx = ctx;
/* Map skb to the sg lists */
sg_init_table(sg, nsg);
rc = skb_to_sgvec(skb, sg, 0, skb->len);
if (unlikely(rc < 0)) {
pr_err("TX: skb_to_sgvec() returned %d, nsg %d!\n", rc, nsg);
goto exit;
}
/* Prepare IV: [SALT (4 octets)][SEQNO (8 octets)]
* In case we're in cluster-key mode, SALT is varied by xor-ing with
* the source address (or w0 of id), otherwise with the dest address
* if dest is known.
*/
ehdr = (struct tipc_ehdr *)skb->data;
salt = aead->salt;
if (aead->mode == CLUSTER_KEY)
salt ^= ehdr->addr; /* __be32 */
else if (__dnode)
salt ^= tipc_node_get_addr(__dnode);
memcpy(iv, &salt, 4);
memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
/* Prepare request */
ehsz = tipc_ehdr_size(ehdr);
aead_request_set_tfm(req, tfm);
aead_request_set_ad(req, ehsz);
aead_request_set_crypt(req, sg, sg, len - ehsz, iv);
/* Set callback function & data */
aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tipc_aead_encrypt_done, skb);
tx_ctx = (struct tipc_crypto_tx_ctx *)ctx;
tx_ctx->aead = aead;
tx_ctx->bearer = b;
memcpy(&tx_ctx->dst, dst, sizeof(*dst));
/* Hold bearer */
if (unlikely(!tipc_bearer_hold(b))) {
rc = -ENODEV;
goto exit;
}
/* Now, do encrypt */
rc = crypto_aead_encrypt(req);
if (rc == -EINPROGRESS || rc == -EBUSY)
return rc;
tipc_bearer_put(b);
exit:
kfree(ctx);
TIPC_SKB_CB(skb)->crypto_ctx = NULL;
return rc;
}
static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
struct tipc_bearer *b = tx_ctx->bearer;
struct tipc_aead *aead = tx_ctx->aead;
struct tipc_crypto *tx = aead->crypto;
struct net *net = tx->net;
switch (err) {
case 0:
this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]);
rcu_read_lock();
if (likely(test_bit(0, &b->up)))
b->media->send_msg(net, skb, b, &tx_ctx->dst);
else
kfree_skb(skb);
rcu_read_unlock();
break;
case -EINPROGRESS:
return;
default:
this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]);
kfree_skb(skb);
break;
}
kfree(tx_ctx);
tipc_bearer_put(b);
tipc_aead_put(aead);
}
/**
* tipc_aead_decrypt - Decrypt an encrypted message
* @net: struct net
* @aead: TIPC AEAD for the message decryption
* @skb: the input/output skb
* @b: TIPC bearer where the message has been received
*
* Return:
* 0 : if the decryption has completed
* -EINPROGRESS/-EBUSY : if a callback will be performed
* < 0 : the decryption has failed
*/
static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
struct sk_buff *skb, struct tipc_bearer *b)
{
struct tipc_crypto_rx_ctx *rx_ctx;
struct aead_request *req;
struct crypto_aead *tfm;
struct sk_buff *unused;
struct scatterlist *sg;
struct tipc_ehdr *ehdr;
int ehsz, nsg, rc;
void *ctx;
u32 salt;
u8 *iv;
if (unlikely(!aead))
return -ENOKEY;
/* Cow skb data if needed */
if (likely(!skb_cloned(skb) &&
(!skb_is_nonlinear(skb) || !skb_has_frag_list(skb)))) {
nsg = 1 + skb_shinfo(skb)->nr_frags;
} else {
nsg = skb_cow_data(skb, 0, &unused);
if (unlikely(nsg < 0)) {
pr_err("RX: skb_cow_data() returned %d\n", nsg);
return nsg;
}
}
/* Allocate memory for the AEAD operation */
tfm = tipc_aead_tfm_next(aead);
ctx = tipc_aead_mem_alloc(tfm, sizeof(*rx_ctx), &iv, &req, &sg, nsg);
if (unlikely(!ctx))
return -ENOMEM;
TIPC_SKB_CB(skb)->crypto_ctx = ctx;
/* Map skb to the sg lists */
sg_init_table(sg, nsg);
rc = skb_to_sgvec(skb, sg, 0, skb->len);
if (unlikely(rc < 0)) {
pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg);
goto exit;
}
/* Reconstruct IV: */
ehdr = (struct tipc_ehdr *)skb->data;
salt = aead->salt;
if (aead->mode == CLUSTER_KEY)
salt ^= ehdr->addr; /* __be32 */
else if (ehdr->destined)
salt ^= tipc_own_addr(net);
memcpy(iv, &salt, 4);
memcpy(iv + 4, (u8 *)&ehdr->seqno, 8);
/* Prepare request */
ehsz = tipc_ehdr_size(ehdr);
aead_request_set_tfm(req, tfm);
aead_request_set_ad(req, ehsz);
aead_request_set_crypt(req, sg, sg, skb->len - ehsz, iv);
/* Set callback function & data */
aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tipc_aead_decrypt_done, skb);
rx_ctx = (struct tipc_crypto_rx_ctx *)ctx;
rx_ctx->aead = aead;
rx_ctx->bearer = b;
/* Hold bearer */
if (unlikely(!tipc_bearer_hold(b))) {
rc = -ENODEV;
goto exit;
}
/* Now, do decrypt */
rc = crypto_aead_decrypt(req);
if (rc == -EINPROGRESS || rc == -EBUSY)
return rc;
tipc_bearer_put(b);
exit:
kfree(ctx);
TIPC_SKB_CB(skb)->crypto_ctx = NULL;
return rc;
}
static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx;
struct tipc_bearer *b = rx_ctx->bearer;
struct tipc_aead *aead = rx_ctx->aead;
struct tipc_crypto_stats __percpu *stats = aead->crypto->stats;
struct net *net = aead->crypto->net;
switch (err) {
case 0:
this_cpu_inc(stats->stat[STAT_ASYNC_OK]);
break;
case -EINPROGRESS:
return;
default:
this_cpu_inc(stats->stat[STAT_ASYNC_NOK]);
break;
}
kfree(rx_ctx);
tipc_crypto_rcv_complete(net, aead, b, &skb, err);
if (likely(skb)) {
if (likely(test_bit(0, &b->up)))
tipc_rcv(net, skb, b);
else
kfree_skb(skb);
}
tipc_bearer_put(b);
}
static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr)
{
return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
}
/**
* tipc_ehdr_validate - Validate an encryption message
* @skb: the message buffer
*
* Returns "true" if this is a valid encryption message, otherwise "false"
*/
bool tipc_ehdr_validate(struct sk_buff *skb)
{
struct tipc_ehdr *ehdr;
int ehsz;
if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE)))
return false;
ehdr = (struct tipc_ehdr *)skb->data;
if (unlikely(ehdr->version != TIPC_EVERSION))
return false;
ehsz = tipc_ehdr_size(ehdr);
if (unlikely(!pskb_may_pull(skb, ehsz)))
return false;
if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE))
return false;
return true;
}
/**
* tipc_ehdr_build - Build TIPC encryption message header
* @net: struct net
* @aead: TX AEAD key to be used for the message encryption
* @tx_key: key id used for the message encryption
* @skb: input/output message skb
* @__rx: RX crypto handle if dest is "known"
*
* Return: the header size if the building is successful, otherwise < 0
*/
static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead,
u8 tx_key, struct sk_buff *skb,
struct tipc_crypto *__rx)
{
struct tipc_msg *hdr = buf_msg(skb);
struct tipc_ehdr *ehdr;
u32 user = msg_user(hdr);
u64 seqno;
int ehsz;
/* Make room for encryption header */
ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE;
WARN_ON(skb_headroom(skb) < ehsz);
ehdr = (struct tipc_ehdr *)skb_push(skb, ehsz);
/* Obtain a seqno first:
* Use the key seqno (= cluster wise) if dest is unknown or we're in
* cluster key mode, otherwise it's better for a per-peer seqno!
*/
if (!__rx || aead->mode == CLUSTER_KEY)
seqno = atomic64_inc_return(&aead->seqno);
else
seqno = atomic64_inc_return(&__rx->sndnxt);
/* Revoke the key if seqno is wrapped around */
if (unlikely(!seqno))
return tipc_crypto_key_revoke(net, tx_key);
/* Word 1-2 */
ehdr->seqno = cpu_to_be64(seqno);
/* Words 0, 3- */
ehdr->version = TIPC_EVERSION;
ehdr->user = 0;
ehdr->keepalive = 0;
ehdr->tx_key = tx_key;
ehdr->destined = (__rx) ? 1 : 0;
ehdr->rx_key_active = (__rx) ? __rx->key.active : 0;
ehdr->rx_nokey = (__rx) ? __rx->nokey : 0;
ehdr->master_key = aead->crypto->key_master;
ehdr->reserved_1 = 0;
ehdr->reserved_2 = 0;
switch (user) {
case LINK_CONFIG:
ehdr->user = LINK_CONFIG;
memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN);
break;
default:
if (user == LINK_PROTOCOL && msg_type(hdr) == STATE_MSG) {
ehdr->user = LINK_PROTOCOL;
ehdr->keepalive = msg_is_keepalive(hdr);
}
ehdr->addr = hdr->hdr[3];
break;
}
return ehsz;
}
static inline void tipc_crypto_key_set_state(struct tipc_crypto *c,
u8 new_passive,
u8 new_active,
u8 new_pending)
{
struct tipc_key old = c->key;
char buf[32];
c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) |
((new_active & KEY_MASK) << (KEY_BITS)) |
((new_pending & KEY_MASK));
pr_debug("%s: key changing %s ::%pS\n", c->name,
tipc_key_change_dump(old, c->key, buf),
__builtin_return_address(0));
}
/**
* tipc_crypto_key_init - Initiate a new user / AEAD key
* @c: TIPC crypto to which new key is attached
* @ukey: the user key
* @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY)
* @master_key: specify this is a cluster master key
*
* A new TIPC AEAD key will be allocated and initiated with the specified user
* key, then attached to the TIPC crypto.
*
* Return: new key id in case of success, otherwise: < 0
*/
int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
u8 mode, bool master_key)
{
struct tipc_aead *aead = NULL;
int rc = 0;
/* Initiate with the new user key */
rc = tipc_aead_init(&aead, ukey, mode);
/* Attach it to the crypto */
if (likely(!rc)) {
rc = tipc_crypto_key_attach(c, aead, 0, master_key);
if (rc < 0)
tipc_aead_free(&aead->rcu);
}
return rc;
}
/**
* tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto
* @c: TIPC crypto to which the new AEAD key is attached
* @aead: the new AEAD key pointer
* @pos: desired slot in the crypto key array, = 0 if any!
* @master_key: specify this is a cluster master key
*
* Return: new key id in case of success, otherwise: -EBUSY
*/
static int tipc_crypto_key_attach(struct tipc_crypto *c,
struct tipc_aead *aead, u8 pos,
bool master_key)
{
struct tipc_key key;
int rc = -EBUSY;
u8 new_key;
spin_lock_bh(&c->lock);
key = c->key;
if (master_key) {
new_key = KEY_MASTER;
goto attach;
}
if (key.active && key.passive)
goto exit;
if (key.pending) {
if (tipc_aead_users(c->aead[key.pending]) > 0)
goto exit;
/* if (pos): ok with replacing, will be aligned when needed */
/* Replace it */
new_key = key.pending;
} else {
if (pos) {
if (key.active && pos != key_next(key.active)) {
key.passive = pos;
new_key = pos;
goto attach;
} else if (!key.active && !key.passive) {
key.pending = pos;
new_key = pos;
goto attach;
}
}
key.pending = key_next(key.active ?: key.passive);
new_key = key.pending;
}
attach:
aead->crypto = c;
aead->gen = (is_tx(c)) ? ++c->key_gen : c->key_gen;
tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock);
if (likely(c->key.keys != key.keys))
tipc_crypto_key_set_state(c, key.passive, key.active,
key.pending);
c->working = 1;
c->nokey = 0;
c->key_master |= master_key;
rc = new_key;
exit:
spin_unlock_bh(&c->lock);
return rc;
}
void tipc_crypto_key_flush(struct tipc_crypto *c)
{
struct tipc_crypto *tx, *rx;
int k;
spin_lock_bh(&c->lock);
if (is_rx(c)) {
/* Try to cancel pending work */
rx = c;
tx = tipc_net(rx->net)->crypto_tx;
if (cancel_delayed_work(&rx->work)) {
kfree(rx->skey);
rx->skey = NULL;
atomic_xchg(&rx->key_distr, 0);
tipc_node_put(rx->node);
}
/* RX stopping => decrease TX key users if any */
k = atomic_xchg(&rx->peer_rx_active, 0);
if (k) {
tipc_aead_users_dec(tx->aead[k], 0);
/* Mark the point TX key users changed */
tx->timer1 = jiffies;
}
}
c->flags = 0;
tipc_crypto_key_set_state(c, 0, 0, 0);
for (k = KEY_MIN; k <= KEY_MAX; k++)
tipc_crypto_key_detach(c->aead[k], &c->lock);
atomic64_set(&c->sndnxt, 0);
spin_unlock_bh(&c->lock);
}
/**
* tipc_crypto_key_try_align - Align RX keys if possible
* @rx: RX crypto handle
* @new_pending: new pending slot if aligned (= TX key from peer)
*
* Peer has used an unknown key slot, this only happens when peer has left and
* rejoned, or we are newcomer.
* That means, there must be no active key but a pending key at unaligned slot.
* If so, we try to move the pending key to the new slot.
* Note: A potential passive key can exist, it will be shifted correspondingly!
*
* Return: "true" if key is successfully aligned, otherwise "false"
*/
static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
{
struct tipc_aead *tmp1, *tmp2 = NULL;
struct tipc_key key;
bool aligned = false;
u8 new_passive = 0;
int x;
spin_lock(&rx->lock);
key = rx->key;
if (key.pending == new_pending) {
aligned = true;
goto exit;
}
if (key.active)
goto exit;
if (!key.pending)
goto exit;
if (tipc_aead_users(rx->aead[key.pending]) > 0)
goto exit;
/* Try to "isolate" this pending key first */
tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock);
if (!refcount_dec_if_one(&tmp1->refcnt))
goto exit;
rcu_assign_pointer(rx->aead[key.pending], NULL);
/* Move passive key if any */
if (key.passive) {
tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock));
x = (key.passive - key.pending + new_pending) % KEY_MAX;
new_passive = (x <= 0) ? x + KEY_MAX : x;
}
/* Re-allocate the key(s) */
tipc_crypto_key_set_state(rx, new_passive, 0, new_pending);
rcu_assign_pointer(rx->aead[new_pending], tmp1);
if (new_passive)
rcu_assign_pointer(rx->aead[new_passive], tmp2);
refcount_set(&tmp1->refcnt, 1);
aligned = true;
pr_info_ratelimited("%s: key[%d] -> key[%d]\n", rx->name, key.pending,
new_pending);
exit:
spin_unlock(&rx->lock);
return aligned;
}
/**
* tipc_crypto_key_pick_tx - Pick one TX key for message decryption
* @tx: TX crypto handle
* @rx: RX crypto handle (can be NULL)
* @skb: the message skb which will be decrypted later
* @tx_key: peer TX key id
*
* This function looks up the existing TX keys and pick one which is suitable
* for the message decryption, that must be a cluster key and not used before
* on the same message (i.e. recursive).
*
* Return: the TX AEAD key handle in case of success, otherwise NULL
*/
static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx,
struct tipc_crypto *rx,
struct sk_buff *skb,
u8 tx_key)
{
struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb);
struct tipc_aead *aead = NULL;
struct tipc_key key = tx->key;
u8 k, i = 0;
/* Initialize data if not yet */
if (!skb_cb->tx_clone_deferred) {
skb_cb->tx_clone_deferred = 1;
memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
}
skb_cb->tx_clone_ctx.rx = rx;
if (++skb_cb->tx_clone_ctx.recurs > 2)
return NULL;
/* Pick one TX key */
spin_lock(&tx->lock);
if (tx_key == KEY_MASTER) {
aead = tipc_aead_rcu_ptr(tx->aead[KEY_MASTER], &tx->lock);
goto done;
}
do {
k = (i == 0) ? key.pending :
((i == 1) ? key.active : key.passive);
if (!k)
continue;
aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock);
if (!aead)
continue;
if (aead->mode != CLUSTER_KEY ||
aead == skb_cb->tx_clone_ctx.last) {
aead = NULL;
continue;
}
/* Ok, found one cluster key */
skb_cb->tx_clone_ctx.last = aead;
WARN_ON(skb->next);
skb->next = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!skb->next))
pr_warn("Failed to clone skb for next round if any\n");
break;
} while (++i < 3);
done:
if (likely(aead))
WARN_ON(!refcount_inc_not_zero(&aead->refcnt));
spin_unlock(&tx->lock);
return aead;
}
/**
* tipc_crypto_key_synch: Synch own key data according to peer key status
* @rx: RX crypto handle
* @skb: TIPCv2 message buffer (incl. the ehdr from peer)
*
* This function updates the peer node related data as the peer RX active key
* has changed, so the number of TX keys' users on this node are increased and
* decreased correspondingly.
*
* It also considers if peer has no key, then we need to make own master key
* (if any) taking over i.e. starting grace period and also trigger key
* distributing process.
*
* The "per-peer" sndnxt is also reset when the peer key has switched.
*/
static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb)
{
struct tipc_ehdr *ehdr = (struct tipc_ehdr *)skb_network_header(skb);
struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
struct tipc_msg *hdr = buf_msg(skb);
u32 self = tipc_own_addr(rx->net);
u8 cur, new;
unsigned long delay;
/* Update RX 'key_master' flag according to peer, also mark "legacy" if
* a peer has no master key.
*/
rx->key_master = ehdr->master_key;
if (!rx->key_master)
tx->legacy_user = 1;
/* For later cases, apply only if message is destined to this node */
if (!ehdr->destined || msg_short(hdr) || msg_destnode(hdr) != self)
return;
/* Case 1: Peer has no keys, let's make master key take over */
if (ehdr->rx_nokey) {
/* Set or extend grace period */
tx->timer2 = jiffies;
/* Schedule key distributing for the peer if not yet */
if (tx->key.keys &&
!atomic_cmpxchg(&rx->key_distr, 0, KEY_DISTR_SCHED)) {
get_random_bytes(&delay, 2);
delay %= 5;
delay = msecs_to_jiffies(500 * ++delay);
if (queue_delayed_work(tx->wq, &rx->work, delay))
tipc_node_get(rx->node);
}
} else {
/* Cancel a pending key distributing if any */
atomic_xchg(&rx->key_distr, 0);
}
/* Case 2: Peer RX active key has changed, let's update own TX users */
cur = atomic_read(&rx->peer_rx_active);
new = ehdr->rx_key_active;
if (tx->key.keys &&
cur != new &&
atomic_cmpxchg(&rx->peer_rx_active, cur, new) == cur) {
if (new)
tipc_aead_users_inc(tx->aead[new], INT_MAX);
if (cur)
tipc_aead_users_dec(tx->aead[cur], 0);
atomic64_set(&rx->sndnxt, 0);
/* Mark the point TX key users changed */
tx->timer1 = jiffies;
pr_debug("%s: key users changed %d-- %d++, peer %s\n",
tx->name, cur, new, rx->name);
}
}
static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
{
struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
struct tipc_key key;
spin_lock(&tx->lock);
key = tx->key;
WARN_ON(!key.active || tx_key != key.active);
/* Free the active key */
tipc_crypto_key_set_state(tx, key.passive, 0, key.pending);
tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
spin_unlock(&tx->lock);
pr_warn("%s: key is revoked\n", tx->name);
return -EKEYREVOKED;
}
int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
struct tipc_node *node)
{
struct tipc_crypto *c;
if (*crypto)
return -EEXIST;
/* Allocate crypto */
c = kzalloc(sizeof(*c), GFP_ATOMIC);
if (!c)
return -ENOMEM;
/* Allocate workqueue on TX */
if (!node) {
c->wq = alloc_ordered_workqueue("tipc_crypto", 0);
if (!c->wq) {
kfree(c);
return -ENOMEM;
}
}
/* Allocate statistic structure */
c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
if (!c->stats) {
kfree_sensitive(c);
return -ENOMEM;
}
c->flags = 0;
c->net = net;
c->node = node;
get_random_bytes(&c->key_gen, 2);
tipc_crypto_key_set_state(c, 0, 0, 0);
atomic_set(&c->key_distr, 0);
atomic_set(&c->peer_rx_active, 0);
atomic64_set(&c->sndnxt, 0);
c->timer1 = jiffies;
c->timer2 = jiffies;
c->rekeying_intv = TIPC_REKEYING_INTV_DEF;
spin_lock_init(&c->lock);
scnprintf(c->name, 48, "%s(%s)", (is_rx(c)) ? "RX" : "TX",
(is_rx(c)) ? tipc_node_get_id_str(c->node) :
tipc_own_id_string(c->net));
if (is_rx(c))
INIT_DELAYED_WORK(&c->work, tipc_crypto_work_rx);
else
INIT_DELAYED_WORK(&c->work, tipc_crypto_work_tx);
*crypto = c;
return 0;
}
void tipc_crypto_stop(struct tipc_crypto **crypto)
{
struct tipc_crypto *c = *crypto;
u8 k;
if (!c)
return;
/* Flush any queued works & destroy wq */
if (is_tx(c)) {
c->rekeying_intv = 0;
cancel_delayed_work_sync(&c->work);
destroy_workqueue(c->wq);
}
/* Release AEAD keys */
rcu_read_lock();
for (k = KEY_MIN; k <= KEY_MAX; k++)
tipc_aead_put(rcu_dereference(c->aead[k]));
rcu_read_unlock();
pr_debug("%s: has been stopped\n", c->name);
/* Free this crypto statistics */
free_percpu(c->stats);
*crypto = NULL;
kfree_sensitive(c);
}
void tipc_crypto_timeout(struct tipc_crypto *rx)
{
struct tipc_net *tn = tipc_net(rx->net);
struct tipc_crypto *tx = tn->crypto_tx;
struct tipc_key key;
int cmd;
/* TX pending: taking all users & stable -> active */
spin_lock(&tx->lock);
key = tx->key;
if (key.active && tipc_aead_users(tx->aead[key.active]) > 0)
goto s1;
if (!key.pending || tipc_aead_users(tx->aead[key.pending]) <= 0)
goto s1;
if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_TIME))
goto s1;
tipc_crypto_key_set_state(tx, key.passive, key.pending, 0);
if (key.active)
tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
this_cpu_inc(tx->stats->stat[STAT_SWITCHES]);
pr_info("%s: key[%d] is activated\n", tx->name, key.pending);
s1:
spin_unlock(&tx->lock);
/* RX pending: having user -> active */
spin_lock(&rx->lock);
key = rx->key;
if (!key.pending || tipc_aead_users(rx->aead[key.pending]) <= 0)
goto s2;
if (key.active)
key.passive = key.active;
key.active = key.pending;
rx->timer2 = jiffies;
tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
this_cpu_inc(rx->stats->stat[STAT_SWITCHES]);
pr_info("%s: key[%d] is activated\n", rx->name, key.pending);
goto s5;
s2:
/* RX pending: not working -> remove */
if (!key.pending || tipc_aead_users(rx->aead[key.pending]) > -10)
goto s3;
tipc_crypto_key_set_state(rx, key.passive, key.active, 0);
tipc_crypto_key_detach(rx->aead[key.pending], &rx->lock);
pr_debug("%s: key[%d] is removed\n", rx->name, key.pending);
goto s5;
s3:
/* RX active: timed out or no user -> pending */
if (!key.active)
goto s4;
if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM) &&
tipc_aead_users(rx->aead[key.active]) > 0)
goto s4;
if (key.pending)
key.passive = key.active;
else
key.pending = key.active;
rx->timer2 = jiffies;
tipc_crypto_key_set_state(rx, key.passive, 0, key.pending);
tipc_aead_users_set(rx->aead[key.pending], 0);
pr_debug("%s: key[%d] is deactivated\n", rx->name, key.active);
goto s5;
s4:
/* RX passive: outdated or not working -> free */
if (!key.passive)
goto s5;
if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM) &&
tipc_aead_users(rx->aead[key.passive]) > -10)
goto s5;
tipc_crypto_key_set_state(rx, 0, key.active, key.pending);
tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock);
pr_debug("%s: key[%d] is freed\n", rx->name, key.passive);
s5:
spin_unlock(&rx->lock);
/* Relax it here, the flag will be set again if it really is, but only
* when we are not in grace period for safety!
*/
if (time_after(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD))
tx->legacy_user = 0;
/* Limit max_tfms & do debug commands if needed */
if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM))
return;
cmd = sysctl_tipc_max_tfms;
sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF;
tipc_crypto_do_cmd(rx->net, cmd);
}
static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb,
struct tipc_bearer *b,
struct tipc_media_addr *dst,
struct tipc_node *__dnode, u8 type)
{
struct sk_buff *skb;
skb = skb_clone(_skb, GFP_ATOMIC);
if (skb) {
TIPC_SKB_CB(skb)->xmit_type = type;
tipc_crypto_xmit(net, &skb, b, dst, __dnode);
if (skb)
b->media->send_msg(net, skb, b, dst);
}
}
/**
* tipc_crypto_xmit - Build & encrypt TIPC message for xmit
* @net: struct net
* @skb: input/output message skb pointer
* @b: bearer used for xmit later
* @dst: destination media address
* @__dnode: destination node for reference if any
*
* First, build an encryption message header on the top of the message, then
* encrypt the original TIPC message by using the pending, master or active
* key with this preference order.
* If the encryption is successful, the encrypted skb is returned directly or
* via the callback.
* Otherwise, the skb is freed!
*
* Return:
* 0 : the encryption has succeeded (or no encryption)
* -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made
* -ENOKEK : the encryption has failed due to no key
* -EKEYREVOKED : the encryption has failed due to key revoked
* -ENOMEM : the encryption has failed due to no memory
* < 0 : the encryption has failed due to other reasons
*/
int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
struct tipc_bearer *b, struct tipc_media_addr *dst,
struct tipc_node *__dnode)
{
struct tipc_crypto *__rx = tipc_node_crypto_rx(__dnode);
struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
struct tipc_crypto_stats __percpu *stats = tx->stats;
struct tipc_msg *hdr = buf_msg(*skb);
struct tipc_key key = tx->key;
struct tipc_aead *aead = NULL;
u32 user = msg_user(hdr);
u32 type = msg_type(hdr);
int rc = -ENOKEY;
u8 tx_key = 0;
/* No encryption? */
if (!tx->working)
return 0;
/* Pending key if peer has active on it or probing time */
if (unlikely(key.pending)) {
tx_key = key.pending;
if (!tx->key_master && !key.active)
goto encrypt;
if (__rx && atomic_read(&__rx->peer_rx_active) == tx_key)
goto encrypt;
if (TIPC_SKB_CB(*skb)->xmit_type == SKB_PROBING) {
pr_debug("%s: probing for key[%d]\n", tx->name,
key.pending);
goto encrypt;
}
if (user == LINK_CONFIG || user == LINK_PROTOCOL)
tipc_crypto_clone_msg(net, *skb, b, dst, __dnode,
SKB_PROBING);
}
/* Master key if this is a *vital* message or in grace period */
if (tx->key_master) {
tx_key = KEY_MASTER;
if (!key.active)
goto encrypt;
if (TIPC_SKB_CB(*skb)->xmit_type == SKB_GRACING) {
pr_debug("%s: gracing for msg (%d %d)\n", tx->name,
user, type);
goto encrypt;
}
if (user == LINK_CONFIG ||
(user == LINK_PROTOCOL && type == RESET_MSG) ||
(user == MSG_CRYPTO && type == KEY_DISTR_MSG) ||
time_before(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) {
if (__rx && __rx->key_master &&
!atomic_read(&__rx->peer_rx_active))
goto encrypt;
if (!__rx) {
if (likely(!tx->legacy_user))
goto encrypt;
tipc_crypto_clone_msg(net, *skb, b, dst,
__dnode, SKB_GRACING);
}
}
}
/* Else, use the active key if any */
if (likely(key.active)) {
tx_key = key.active;
goto encrypt;
}
goto exit;
encrypt:
aead = tipc_aead_get(tx->aead[tx_key]);
if (unlikely(!aead))
goto exit;
rc = tipc_ehdr_build(net, aead, tx_key, *skb, __rx);
if (likely(rc > 0))
rc = tipc_aead_encrypt(aead, *skb, b, dst, __dnode);
exit:
switch (rc) {
case 0:
this_cpu_inc(stats->stat[STAT_OK]);
break;
case -EINPROGRESS:
case -EBUSY:
this_cpu_inc(stats->stat[STAT_ASYNC]);
*skb = NULL;
return rc;
default:
this_cpu_inc(stats->stat[STAT_NOK]);
if (rc == -ENOKEY)
this_cpu_inc(stats->stat[STAT_NOKEYS]);
else if (rc == -EKEYREVOKED)
this_cpu_inc(stats->stat[STAT_BADKEYS]);
kfree_skb(*skb);
*skb = NULL;
break;
}
tipc_aead_put(aead);
return rc;
}
/**
* tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer
* @net: struct net
* @rx: RX crypto handle
* @skb: input/output message skb pointer
* @b: bearer where the message has been received
*
* If the decryption is successful, the decrypted skb is returned directly or
* as the callback, the encryption header and auth tag will be trimed out
* before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete().
* Otherwise, the skb will be freed!
* Note: RX key(s) can be re-aligned, or in case of no key suitable, TX
* cluster key(s) can be taken for decryption (- recursive).
*
* Return:
* 0 : the decryption has successfully completed
* -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made
* -ENOKEY : the decryption has failed due to no key
* -EBADMSG : the decryption has failed due to bad message
* -ENOMEM : the decryption has failed due to no memory
* < 0 : the decryption has failed due to other reasons
*/
int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
struct sk_buff **skb, struct tipc_bearer *b)
{
struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
struct tipc_crypto_stats __percpu *stats;
struct tipc_aead *aead = NULL;
struct tipc_key key;
int rc = -ENOKEY;
u8 tx_key, n;
tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key;
/* New peer?
* Let's try with TX key (i.e. cluster mode) & verify the skb first!
*/
if (unlikely(!rx || tx_key == KEY_MASTER))
goto pick_tx;
/* Pick RX key according to TX key if any */
key = rx->key;
if (tx_key == key.active || tx_key == key.pending ||
tx_key == key.passive)
goto decrypt;
/* Unknown key, let's try to align RX key(s) */
if (tipc_crypto_key_try_align(rx, tx_key))
goto decrypt;
pick_tx:
/* No key suitable? Try to pick one from TX... */
aead = tipc_crypto_key_pick_tx(tx, rx, *skb, tx_key);
if (aead)
goto decrypt;
goto exit;
decrypt:
rcu_read_lock();
if (!aead)
aead = tipc_aead_get(rx->aead[tx_key]);
rc = tipc_aead_decrypt(net, aead, *skb, b);
rcu_read_unlock();
exit:
stats = ((rx) ?: tx)->stats;
switch (rc) {
case 0:
this_cpu_inc(stats->stat[STAT_OK]);
break;
case -EINPROGRESS:
case -EBUSY:
this_cpu_inc(stats->stat[STAT_ASYNC]);
*skb = NULL;
return rc;
default:
this_cpu_inc(stats->stat[STAT_NOK]);
if (rc == -ENOKEY) {
kfree_skb(*skb);
*skb = NULL;
if (rx) {
/* Mark rx->nokey only if we dont have a
* pending received session key, nor a newer
* one i.e. in the next slot.
*/
n = key_next(tx_key);
rx->nokey = !(rx->skey ||
rcu_access_pointer(rx->aead[n]));
pr_debug_ratelimited("%s: nokey %d, key %d/%x\n",
rx->name, rx->nokey,
tx_key, rx->key.keys);
tipc_node_put(rx->node);
}
this_cpu_inc(stats->stat[STAT_NOKEYS]);
return rc;
} else if (rc == -EBADMSG) {
this_cpu_inc(stats->stat[STAT_BADMSGS]);
}
break;
}
tipc_crypto_rcv_complete(net, aead, b, skb, rc);
return rc;
}
static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead,
struct tipc_bearer *b,
struct sk_buff **skb, int err)
{
struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb);
struct tipc_crypto *rx = aead->crypto;
struct tipc_aead *tmp = NULL;
struct tipc_ehdr *ehdr;
struct tipc_node *n;
/* Is this completed by TX? */
if (unlikely(is_tx(aead->crypto))) {
rx = skb_cb->tx_clone_ctx.rx;
pr_debug("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n",
(rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead,
(*skb)->next, skb_cb->flags);
pr_debug("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n",
skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last,
aead->crypto->aead[1], aead->crypto->aead[2],
aead->crypto->aead[3]);
if (unlikely(err)) {
if (err == -EBADMSG && (*skb)->next)
tipc_rcv(net, (*skb)->next, b);
goto free_skb;
}
if (likely((*skb)->next)) {
kfree_skb((*skb)->next);
(*skb)->next = NULL;
}
ehdr = (struct tipc_ehdr *)(*skb)->data;
if (!rx) {
WARN_ON(ehdr->user != LINK_CONFIG);
n = tipc_node_create(net, 0, ehdr->id, 0xffffu, 0,
true);
rx = tipc_node_crypto_rx(n);
if (unlikely(!rx))
goto free_skb;
}
/* Ignore cloning if it was TX master key */
if (ehdr->tx_key == KEY_MASTER)
goto rcv;
if (tipc_aead_clone(&tmp, aead) < 0)
goto rcv;
if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key, false) < 0) {
tipc_aead_free(&tmp->rcu);
goto rcv;
}
tipc_aead_put(aead);
aead = tipc_aead_get(tmp);
}
if (unlikely(err)) {
tipc_aead_users_dec(aead, INT_MIN);
goto free_skb;
}
/* Set the RX key's user */
tipc_aead_users_set(aead, 1);
/* Mark this point, RX works */
rx->timer1 = jiffies;
rcv:
/* Remove ehdr & auth. tag prior to tipc_rcv() */
ehdr = (struct tipc_ehdr *)(*skb)->data;
/* Mark this point, RX passive still works */
if (rx->key.passive && ehdr->tx_key == rx->key.passive)
rx->timer2 = jiffies;
skb_reset_network_header(*skb);
skb_pull(*skb, tipc_ehdr_size(ehdr));
pskb_trim(*skb, (*skb)->len - aead->authsize);
/* Validate TIPCv2 message */
if (unlikely(!tipc_msg_validate(skb))) {
pr_err_ratelimited("Packet dropped after decryption!\n");
goto free_skb;
}
/* Ok, everything's fine, try to synch own keys according to peers' */
tipc_crypto_key_synch(rx, *skb);
/* Mark skb decrypted */
skb_cb->decrypted = 1;
/* Clear clone cxt if any */
if (likely(!skb_cb->tx_clone_deferred))
goto exit;
skb_cb->tx_clone_deferred = 0;
memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx));
goto exit;
free_skb:
kfree_skb(*skb);
*skb = NULL;
exit:
tipc_aead_put(aead);
if (rx)
tipc_node_put(rx->node);
}
static void tipc_crypto_do_cmd(struct net *net, int cmd)
{
struct tipc_net *tn = tipc_net(net);
struct tipc_crypto *tx = tn->crypto_tx, *rx;
struct list_head *p;
unsigned int stat;
int i, j, cpu;
char buf[200];
/* Currently only one command is supported */
switch (cmd) {
case 0xfff1:
goto print_stats;
default:
return;
}
print_stats:
/* Print a header */
pr_info("\n=============== TIPC Crypto Statistics ===============\n\n");
/* Print key status */
pr_info("Key status:\n");
pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net),
tipc_crypto_key_dump(tx, buf));
rcu_read_lock();
for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
rx = tipc_node_crypto_rx_by_list(p);
pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node),
tipc_crypto_key_dump(rx, buf));
}
rcu_read_unlock();
/* Print crypto statistics */
for (i = 0, j = 0; i < MAX_STATS; i++)
j += scnprintf(buf + j, 200 - j, "|%11s ", hstats[i]);
pr_info("Counter %s", buf);
memset(buf, '-', 115);
buf[115] = '\0';
pr_info("%s\n", buf);
j = scnprintf(buf, 200, "TX(%7.7s) ", tipc_own_id_string(net));
for_each_possible_cpu(cpu) {
for (i = 0; i < MAX_STATS; i++) {
stat = per_cpu_ptr(tx->stats, cpu)->stat[i];
j += scnprintf(buf + j, 200 - j, "|%11d ", stat);
}
pr_info("%s", buf);
j = scnprintf(buf, 200, "%12s", " ");
}
rcu_read_lock();
for (p = tn->node_list.next; p != &tn->node_list; p = p->next) {
rx = tipc_node_crypto_rx_by_list(p);
j = scnprintf(buf, 200, "RX(%7.7s) ",
tipc_node_get_id_str(rx->node));
for_each_possible_cpu(cpu) {
for (i = 0; i < MAX_STATS; i++) {
stat = per_cpu_ptr(rx->stats, cpu)->stat[i];
j += scnprintf(buf + j, 200 - j, "|%11d ",
stat);
}
pr_info("%s", buf);
j = scnprintf(buf, 200, "%12s", " ");
}
}
rcu_read_unlock();
pr_info("\n======================== Done ========================\n");
}
static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf)
{
struct tipc_key key = c->key;
struct tipc_aead *aead;
int k, i = 0;
char *s;
for (k = KEY_MIN; k <= KEY_MAX; k++) {
if (k == KEY_MASTER) {
if (is_rx(c))
continue;
if (time_before(jiffies,
c->timer2 + TIPC_TX_GRACE_PERIOD))
s = "ACT";
else
s = "PAS";
} else {
if (k == key.passive)
s = "PAS";
else if (k == key.active)
s = "ACT";
else if (k == key.pending)
s = "PEN";
else
s = "-";
}
i += scnprintf(buf + i, 200 - i, "\tKey%d: %s", k, s);
rcu_read_lock();
aead = rcu_dereference(c->aead[k]);
if (aead)
i += scnprintf(buf + i, 200 - i,
"{\"0x...%s\", \"%s\"}/%d:%d",
aead->hint,
(aead->mode == CLUSTER_KEY) ? "c" : "p",
atomic_read(&aead->users),
refcount_read(&aead->refcnt));
rcu_read_unlock();
i += scnprintf(buf + i, 200 - i, "\n");
}
if (is_rx(c))
i += scnprintf(buf + i, 200 - i, "\tPeer RX active: %d\n",
atomic_read(&c->peer_rx_active));
return buf;
}
static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
char *buf)
{
struct tipc_key *key = &old;
int k, i = 0;
char *s;
/* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */
again:
i += scnprintf(buf + i, 32 - i, "[");
for (k = KEY_1; k <= KEY_3; k++) {
if (k == key->passive)
s = "pas";
else if (k == key->active)
s = "act";
else if (k == key->pending)
s = "pen";
else
s = "-";
i += scnprintf(buf + i, 32 - i,
(k != KEY_3) ? "%s " : "%s", s);
}
if (key != &new) {
i += scnprintf(buf + i, 32 - i, "] -> ");
key = &new;
goto again;
}
i += scnprintf(buf + i, 32 - i, "]");
return buf;
}
/**
* tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point
* @net: the struct net
* @skb: the receiving message buffer
*/
void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb)
{
struct tipc_crypto *rx;
struct tipc_msg *hdr;
if (unlikely(skb_linearize(skb)))
goto exit;
hdr = buf_msg(skb);
rx = tipc_node_crypto_rx_by_addr(net, msg_prevnode(hdr));
if (unlikely(!rx))
goto exit;
switch (msg_type(hdr)) {
case KEY_DISTR_MSG:
if (tipc_crypto_key_rcv(rx, hdr))
goto exit;
break;
default:
break;
}
tipc_node_put(rx->node);
exit:
kfree_skb(skb);
}
/**
* tipc_crypto_key_distr - Distribute a TX key
* @tx: the TX crypto
* @key: the key's index
* @dest: the destination tipc node, = NULL if distributing to all nodes
*
* Return: 0 in case of success, otherwise < 0
*/
int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key,
struct tipc_node *dest)
{
struct tipc_aead *aead;
u32 dnode = tipc_node_get_addr(dest);
int rc = -ENOKEY;
if (!sysctl_tipc_key_exchange_enabled)
return 0;
if (key) {
rcu_read_lock();
aead = tipc_aead_get(tx->aead[key]);
if (likely(aead)) {
rc = tipc_crypto_key_xmit(tx->net, aead->key,
aead->gen, aead->mode,
dnode);
tipc_aead_put(aead);
}
rcu_read_unlock();
}
return rc;
}
/**
* tipc_crypto_key_xmit - Send a session key
* @net: the struct net
* @skey: the session key to be sent
* @gen: the key's generation
* @mode: the key's mode
* @dnode: the destination node address, = 0 if broadcasting to all nodes
*
* The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG'
* as its data section, then xmit-ed through the uc/bc link.
*
* Return: 0 in case of success, otherwise < 0
*/
static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey,
u16 gen, u8 mode, u32 dnode)
{
struct sk_buff_head pkts;
struct tipc_msg *hdr;
struct sk_buff *skb;
u16 size, cong_link_cnt;
u8 *data;
int rc;
size = tipc_aead_key_size(skey);
skb = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
if (!skb)
return -ENOMEM;
hdr = buf_msg(skb);
tipc_msg_init(tipc_own_addr(net), hdr, MSG_CRYPTO, KEY_DISTR_MSG,
INT_H_SIZE, dnode);
msg_set_size(hdr, INT_H_SIZE + size);
msg_set_key_gen(hdr, gen);
msg_set_key_mode(hdr, mode);
data = msg_data(hdr);
*((__be32 *)(data + TIPC_AEAD_ALG_NAME)) = htonl(skey->keylen);
memcpy(data, skey->alg_name, TIPC_AEAD_ALG_NAME);
memcpy(data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->key,
skey->keylen);
__skb_queue_head_init(&pkts);
__skb_queue_tail(&pkts, skb);
if (dnode)
rc = tipc_node_xmit(net, &pkts, dnode, 0);
else
rc = tipc_bcast_xmit(net, &pkts, &cong_link_cnt);
return rc;
}
/**
* tipc_crypto_key_rcv - Receive a session key
* @rx: the RX crypto
* @hdr: the TIPC v2 message incl. the receiving session key in its data
*
* This function retrieves the session key in the message from peer, then
* schedules a RX work to attach the key to the corresponding RX crypto.
*
* Return: "true" if the key has been scheduled for attaching, otherwise
* "false".
*/
static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr)
{
struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
struct tipc_aead_key *skey = NULL;
u16 key_gen = msg_key_gen(hdr);
u16 size = msg_data_sz(hdr);
u8 *data = msg_data(hdr);
spin_lock(&rx->lock);
if (unlikely(rx->skey || (key_gen == rx->key_gen && rx->key.keys))) {
pr_err("%s: key existed <%p>, gen %d vs %d\n", rx->name,
rx->skey, key_gen, rx->key_gen);
goto exit;
}
/* Allocate memory for the key */
skey = kmalloc(size, GFP_ATOMIC);
if (unlikely(!skey)) {
pr_err("%s: unable to allocate memory for skey\n", rx->name);
goto exit;
}
/* Copy key from msg data */
skey->keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME)));
memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME);
memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32),
skey->keylen);
/* Sanity check */
if (unlikely(size != tipc_aead_key_size(skey))) {
kfree(skey);
skey = NULL;
goto exit;
}
rx->key_gen = key_gen;
rx->skey_mode = msg_key_mode(hdr);
rx->skey = skey;
rx->nokey = 0;
mb(); /* for nokey flag */
exit:
spin_unlock(&rx->lock);
/* Schedule the key attaching on this crypto */
if (likely(skey && queue_delayed_work(tx->wq, &rx->work, 0)))
return true;
return false;
}
/**
* tipc_crypto_work_rx - Scheduled RX works handler
* @work: the struct RX work
*
* The function processes the previous scheduled works i.e. distributing TX key
* or attaching a received session key on RX crypto.
*/
static void tipc_crypto_work_rx(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct tipc_crypto *rx = container_of(dwork, struct tipc_crypto, work);
struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx;
unsigned long delay = msecs_to_jiffies(5000);
bool resched = false;
u8 key;
int rc;
/* Case 1: Distribute TX key to peer if scheduled */
if (atomic_cmpxchg(&rx->key_distr,
KEY_DISTR_SCHED,
KEY_DISTR_COMPL) == KEY_DISTR_SCHED) {
/* Always pick the newest one for distributing */
key = tx->key.pending ?: tx->key.active;
rc = tipc_crypto_key_distr(tx, key, rx->node);
if (unlikely(rc))
pr_warn("%s: unable to distr key[%d] to %s, err %d\n",
tx->name, key, tipc_node_get_id_str(rx->node),
rc);
/* Sched for key_distr releasing */
resched = true;
} else {
atomic_cmpxchg(&rx->key_distr, KEY_DISTR_COMPL, 0);
}
/* Case 2: Attach a pending received session key from peer if any */
if (rx->skey) {
rc = tipc_crypto_key_init(rx, rx->skey, rx->skey_mode, false);
if (unlikely(rc < 0))
pr_warn("%s: unable to attach received skey, err %d\n",
rx->name, rc);
switch (rc) {
case -EBUSY:
case -ENOMEM:
/* Resched the key attaching */
resched = true;
break;
default:
synchronize_rcu();
kfree(rx->skey);
rx->skey = NULL;
break;
}
}
if (resched && queue_delayed_work(tx->wq, &rx->work, delay))
return;
tipc_node_put(rx->node);
}
/**
* tipc_crypto_rekeying_sched - (Re)schedule rekeying w/o new interval
* @tx: TX crypto
* @changed: if the rekeying needs to be rescheduled with new interval
* @new_intv: new rekeying interval (when "changed" = true)
*/
void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed,
u32 new_intv)
{
unsigned long delay;
bool now = false;
if (changed) {
if (new_intv == TIPC_REKEYING_NOW)
now = true;
else
tx->rekeying_intv = new_intv;
cancel_delayed_work_sync(&tx->work);
}
if (tx->rekeying_intv || now) {
delay = (now) ? 0 : tx->rekeying_intv * 60 * 1000;
queue_delayed_work(tx->wq, &tx->work, msecs_to_jiffies(delay));
}
}
/**
* tipc_crypto_work_tx - Scheduled TX works handler
* @work: the struct TX work
*
* The function processes the previous scheduled work, i.e. key rekeying, by
* generating a new session key based on current one, then attaching it to the
* TX crypto and finally distributing it to peers. It also re-schedules the
* rekeying if needed.
*/
static void tipc_crypto_work_tx(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct tipc_crypto *tx = container_of(dwork, struct tipc_crypto, work);
struct tipc_aead_key *skey = NULL;
struct tipc_key key = tx->key;
struct tipc_aead *aead;
int rc = -ENOMEM;
if (unlikely(key.pending))
goto resched;
/* Take current key as a template */
rcu_read_lock();
aead = rcu_dereference(tx->aead[key.active ?: KEY_MASTER]);
if (unlikely(!aead)) {
rcu_read_unlock();
/* At least one key should exist for securing */
return;
}
/* Lets duplicate it first */
skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_ATOMIC);
rcu_read_unlock();
/* Now, generate new key, initiate & distribute it */
if (likely(skey)) {
rc = tipc_aead_key_generate(skey) ?:
tipc_crypto_key_init(tx, skey, PER_NODE_KEY, false);
if (likely(rc > 0))
rc = tipc_crypto_key_distr(tx, rc, NULL);
kzfree(skey);
}
if (unlikely(rc))
pr_warn_ratelimited("%s: rekeying returns %d\n", tx->name, rc);
resched:
/* Re-schedule rekeying if any */
tipc_crypto_rekeying_sched(tx, false, 0);
}
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