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Diffstat (limited to 'net/tipc/crypto.c')
| -rw-r--r-- | net/tipc/crypto.c | 2479 |
1 files changed, 2479 insertions, 0 deletions
diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c new file mode 100644 index 000000000..b5aa0a835 --- /dev/null +++ b/net/tipc/crypto.c @@ -0,0 +1,2479 @@ +// 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); + kfree_sensitive(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); + if (!tmp->key) { + tipc_aead_free(&tmp->rcu); + return -ENOMEM; + } + 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; + + 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_bh(&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_bh(&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) { + if (c->wq) + destroy_workqueue(c->wq); + 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; + WARN_ON(!refcount_inc_not_zero(&tmp->refcnt)); + if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key, false) < 0) { + tipc_aead_free(&tmp->rcu); + goto rcv; + } + tipc_aead_put(aead); + aead = 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)); + if (pskb_trim(*skb, (*skb)->len - aead->authsize)) + goto free_skb; + + /* 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); + + /* Re-fetch skb cb as skb might be changed in tipc_msg_validate */ + skb_cb = TIPC_SKB_CB(*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); + u32 size = msg_data_sz(hdr); + u8 *data = msg_data(hdr); + unsigned int keylen; + + /* Verify whether the size can exist in the packet */ + if (unlikely(size < sizeof(struct tipc_aead_key) + TIPC_AEAD_KEYLEN_MIN)) { + pr_debug("%s: message data size is too small\n", rx->name); + goto exit; + } + + keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME))); + + /* Verify the supplied size values */ + if (unlikely(size != keylen + sizeof(struct tipc_aead_key) || + keylen > TIPC_AEAD_KEY_SIZE_MAX)) { + pr_debug("%s: invalid MSG_CRYPTO key size\n", rx->name); + goto exit; + } + + 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_unlock; + } + + /* 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_unlock; + } + + /* Copy key from msg data */ + skey->keylen = keylen; + memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME); + memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32), + skey->keylen); + + rx->key_gen = key_gen; + rx->skey_mode = msg_key_mode(hdr); + rx->skey = skey; + rx->nokey = 0; + mb(); /* for nokey flag */ + +exit_unlock: + spin_unlock(&rx->lock); + +exit: + /* 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); + kfree_sensitive(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); +} |