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linux_old1/net/mac802154/llsec.c

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/*
* Copyright (C) 2014 Fraunhofer ITWM
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Written by:
* Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
*/
#include <linux/err.h>
#include <linux/bug.h>
#include <linux/completion.h>
#include <net/ieee802154.h>
#include <crypto/algapi.h>
#include "mac802154.h"
#include "llsec.h"
static void llsec_key_put(struct mac802154_llsec_key *key);
static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
const struct ieee802154_llsec_key_id *b);
static void llsec_dev_free(struct mac802154_llsec_device *dev);
void mac802154_llsec_init(struct mac802154_llsec *sec)
{
memset(sec, 0, sizeof(*sec));
memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN);
INIT_LIST_HEAD(&sec->table.security_levels);
INIT_LIST_HEAD(&sec->table.devices);
INIT_LIST_HEAD(&sec->table.keys);
hash_init(sec->devices_short);
hash_init(sec->devices_hw);
rwlock_init(&sec->lock);
}
void mac802154_llsec_destroy(struct mac802154_llsec *sec)
{
struct ieee802154_llsec_seclevel *sl, *sn;
struct ieee802154_llsec_device *dev, *dn;
struct ieee802154_llsec_key_entry *key, *kn;
list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) {
struct mac802154_llsec_seclevel *msl;
msl = container_of(sl, struct mac802154_llsec_seclevel, level);
list_del(&sl->list);
kfree(msl);
}
list_for_each_entry_safe(dev, dn, &sec->table.devices, list) {
struct mac802154_llsec_device *mdev;
mdev = container_of(dev, struct mac802154_llsec_device, dev);
list_del(&dev->list);
llsec_dev_free(mdev);
}
list_for_each_entry_safe(key, kn, &sec->table.keys, list) {
struct mac802154_llsec_key *mkey;
mkey = container_of(key->key, struct mac802154_llsec_key, key);
list_del(&key->list);
llsec_key_put(mkey);
kfree(key);
}
}
int mac802154_llsec_get_params(struct mac802154_llsec *sec,
struct ieee802154_llsec_params *params)
{
read_lock_bh(&sec->lock);
*params = sec->params;
read_unlock_bh(&sec->lock);
return 0;
}
int mac802154_llsec_set_params(struct mac802154_llsec *sec,
const struct ieee802154_llsec_params *params,
int changed)
{
write_lock_bh(&sec->lock);
if (changed & IEEE802154_LLSEC_PARAM_ENABLED)
sec->params.enabled = params->enabled;
if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER)
sec->params.frame_counter = params->frame_counter;
if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL)
sec->params.out_level = params->out_level;
if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY)
sec->params.out_key = params->out_key;
if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE)
sec->params.default_key_source = params->default_key_source;
if (changed & IEEE802154_LLSEC_PARAM_PAN_ID)
sec->params.pan_id = params->pan_id;
if (changed & IEEE802154_LLSEC_PARAM_HWADDR)
sec->params.hwaddr = params->hwaddr;
if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR)
sec->params.coord_hwaddr = params->coord_hwaddr;
if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR)
sec->params.coord_shortaddr = params->coord_shortaddr;
write_unlock_bh(&sec->lock);
return 0;
}
static struct mac802154_llsec_key*
llsec_key_alloc(const struct ieee802154_llsec_key *template)
{
const int authsizes[3] = { 4, 8, 16 };
struct mac802154_llsec_key *key;
int i;
key = kzalloc(sizeof(*key), GFP_KERNEL);
if (!key)
return NULL;
kref_init(&key->ref);
key->key = *template;
BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm));
for (i = 0; i < ARRAY_SIZE(key->tfm); i++) {
key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0,
CRYPTO_ALG_ASYNC);
if (!key->tfm[i])
goto err_tfm;
if (crypto_aead_setkey(key->tfm[i], template->key,
IEEE802154_LLSEC_KEY_SIZE))
goto err_tfm;
if (crypto_aead_setauthsize(key->tfm[i], authsizes[i]))
goto err_tfm;
}
key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
if (!key->tfm0)
goto err_tfm;
if (crypto_blkcipher_setkey(key->tfm0, template->key,
IEEE802154_LLSEC_KEY_SIZE))
goto err_tfm0;
return key;
err_tfm0:
crypto_free_blkcipher(key->tfm0);
err_tfm:
for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
if (key->tfm[i])
crypto_free_aead(key->tfm[i]);
kfree(key);
return NULL;
}
static void llsec_key_release(struct kref *ref)
{
struct mac802154_llsec_key *key;
int i;
key = container_of(ref, struct mac802154_llsec_key, ref);
for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
crypto_free_aead(key->tfm[i]);
crypto_free_blkcipher(key->tfm0);
kfree(key);
}
static struct mac802154_llsec_key*
llsec_key_get(struct mac802154_llsec_key *key)
{
kref_get(&key->ref);
return key;
}
static void llsec_key_put(struct mac802154_llsec_key *key)
{
kref_put(&key->ref, llsec_key_release);
}
static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
const struct ieee802154_llsec_key_id *b)
{
if (a->mode != b->mode)
return false;
if (a->mode == IEEE802154_SCF_KEY_IMPLICIT)
return ieee802154_addr_equal(&a->device_addr, &b->device_addr);
if (a->id != b->id)
return false;
switch (a->mode) {
case IEEE802154_SCF_KEY_INDEX:
return true;
case IEEE802154_SCF_KEY_SHORT_INDEX:
return a->short_source == b->short_source;
case IEEE802154_SCF_KEY_HW_INDEX:
return a->extended_source == b->extended_source;
}
return false;
}
int mac802154_llsec_key_add(struct mac802154_llsec *sec,
const struct ieee802154_llsec_key_id *id,
const struct ieee802154_llsec_key *key)
{
struct mac802154_llsec_key *mkey = NULL;
struct ieee802154_llsec_key_entry *pos, *new;
if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) &&
key->cmd_frame_ids)
return -EINVAL;
list_for_each_entry(pos, &sec->table.keys, list) {
if (llsec_key_id_equal(&pos->id, id))
return -EEXIST;
if (memcmp(pos->key->key, key->key,
IEEE802154_LLSEC_KEY_SIZE))
continue;
mkey = container_of(pos->key, struct mac802154_llsec_key, key);
/* Don't allow multiple instances of the same AES key to have
* different allowed frame types/command frame ids, as this is
* not possible in the 802.15.4 PIB.
*/
if (pos->key->frame_types != key->frame_types ||
pos->key->cmd_frame_ids != key->cmd_frame_ids)
return -EEXIST;
break;
}
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
if (!mkey)
mkey = llsec_key_alloc(key);
else
mkey = llsec_key_get(mkey);
if (!mkey)
goto fail;
new->id = *id;
new->key = &mkey->key;
list_add_rcu(&new->list, &sec->table.keys);
return 0;
fail:
kfree(new);
return -ENOMEM;
}
int mac802154_llsec_key_del(struct mac802154_llsec *sec,
const struct ieee802154_llsec_key_id *key)
{
struct ieee802154_llsec_key_entry *pos;
list_for_each_entry(pos, &sec->table.keys, list) {
struct mac802154_llsec_key *mkey;
mkey = container_of(pos->key, struct mac802154_llsec_key, key);
if (llsec_key_id_equal(&pos->id, key)) {
list_del_rcu(&pos->list);
llsec_key_put(mkey);
return 0;
}
}
return -ENOENT;
}
static bool llsec_dev_use_shortaddr(__le16 short_addr)
{
return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) &&
short_addr != cpu_to_le16(0xffff);
}
static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id)
{
return ((__force u16) short_addr) << 16 | (__force u16) pan_id;
}
static u64 llsec_dev_hash_long(__le64 hwaddr)
{
return (__force u64) hwaddr;
}
static struct mac802154_llsec_device*
llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr,
__le16 pan_id)
{
struct mac802154_llsec_device *dev;
u32 key = llsec_dev_hash_short(short_addr, pan_id);
hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) {
if (dev->dev.short_addr == short_addr &&
dev->dev.pan_id == pan_id)
return dev;
}
return NULL;
}
static struct mac802154_llsec_device*
llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr)
{
struct mac802154_llsec_device *dev;
u64 key = llsec_dev_hash_long(hwaddr);
hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) {
if (dev->dev.hwaddr == hwaddr)
return dev;
}
return NULL;
}
static void llsec_dev_free(struct mac802154_llsec_device *dev)
{
struct ieee802154_llsec_device_key *pos, *pn;
struct mac802154_llsec_device_key *devkey;
list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) {
devkey = container_of(pos, struct mac802154_llsec_device_key,
devkey);
list_del(&pos->list);
kfree(devkey);
}
kfree(dev);
}
int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
const struct ieee802154_llsec_device *dev)
{
struct mac802154_llsec_device *entry;
u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id);
u64 hwkey = llsec_dev_hash_long(dev->hwaddr);
BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN);
if ((llsec_dev_use_shortaddr(dev->short_addr) &&
llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) ||
llsec_dev_find_long(sec, dev->hwaddr))
return -EEXIST;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->dev = *dev;
spin_lock_init(&entry->lock);
INIT_LIST_HEAD(&entry->dev.keys);
if (llsec_dev_use_shortaddr(dev->short_addr))
hash_add_rcu(sec->devices_short, &entry->bucket_s, skey);
else
INIT_HLIST_NODE(&entry->bucket_s);
hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey);
list_add_tail_rcu(&entry->dev.list, &sec->table.devices);
return 0;
}
static void llsec_dev_free_rcu(struct rcu_head *rcu)
{
llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu));
}
int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr)
{
struct mac802154_llsec_device *pos;
pos = llsec_dev_find_long(sec, device_addr);
if (!pos)
return -ENOENT;
hash_del_rcu(&pos->bucket_s);
hash_del_rcu(&pos->bucket_hw);
call_rcu(&pos->rcu, llsec_dev_free_rcu);
return 0;
}
static struct mac802154_llsec_device_key*
llsec_devkey_find(struct mac802154_llsec_device *dev,
const struct ieee802154_llsec_key_id *key)
{
struct ieee802154_llsec_device_key *devkey;
list_for_each_entry_rcu(devkey, &dev->dev.keys, list) {
if (!llsec_key_id_equal(key, &devkey->key_id))
continue;
return container_of(devkey, struct mac802154_llsec_device_key,
devkey);
}
return NULL;
}
int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
__le64 dev_addr,
const struct ieee802154_llsec_device_key *key)
{
struct mac802154_llsec_device *dev;
struct mac802154_llsec_device_key *devkey;
dev = llsec_dev_find_long(sec, dev_addr);
if (!dev)
return -ENOENT;
if (llsec_devkey_find(dev, &key->key_id))
return -EEXIST;
devkey = kmalloc(sizeof(*devkey), GFP_KERNEL);
if (!devkey)
return -ENOMEM;
devkey->devkey = *key;
list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys);
return 0;
}
int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
__le64 dev_addr,
const struct ieee802154_llsec_device_key *key)
{
struct mac802154_llsec_device *dev;
struct mac802154_llsec_device_key *devkey;
dev = llsec_dev_find_long(sec, dev_addr);
if (!dev)
return -ENOENT;
devkey = llsec_devkey_find(dev, &key->key_id);
if (!devkey)
return -ENOENT;
list_del_rcu(&devkey->devkey.list);
kfree_rcu(devkey, rcu);
return 0;
}
static struct mac802154_llsec_seclevel*
llsec_find_seclevel(const struct mac802154_llsec *sec,
const struct ieee802154_llsec_seclevel *sl)
{
struct ieee802154_llsec_seclevel *pos;
list_for_each_entry(pos, &sec->table.security_levels, list) {
if (pos->frame_type != sl->frame_type ||
(pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD &&
pos->cmd_frame_id != sl->cmd_frame_id) ||
pos->device_override != sl->device_override ||
pos->sec_levels != sl->sec_levels)
continue;
return container_of(pos, struct mac802154_llsec_seclevel,
level);
}
return NULL;
}
int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
const struct ieee802154_llsec_seclevel *sl)
{
struct mac802154_llsec_seclevel *entry;
if (llsec_find_seclevel(sec, sl))
return -EEXIST;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->level = *sl;
list_add_tail_rcu(&entry->level.list, &sec->table.security_levels);
return 0;
}
int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
const struct ieee802154_llsec_seclevel *sl)
{
struct mac802154_llsec_seclevel *pos;
pos = llsec_find_seclevel(sec, sl);
if (!pos)
return -ENOENT;
list_del_rcu(&pos->level.list);
kfree_rcu(pos, rcu);
return 0;
}
static int llsec_recover_addr(struct mac802154_llsec *sec,
struct ieee802154_addr *addr)
{
__le16 caddr = sec->params.coord_shortaddr;
addr->pan_id = sec->params.pan_id;
if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
return -EINVAL;
} else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
addr->extended_addr = sec->params.coord_hwaddr;
addr->mode = IEEE802154_ADDR_LONG;
} else {
addr->short_addr = sec->params.coord_shortaddr;
addr->mode = IEEE802154_ADDR_SHORT;
}
return 0;
}
static struct mac802154_llsec_key*
llsec_lookup_key(struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
const struct ieee802154_addr *addr,
struct ieee802154_llsec_key_id *key_id)
{
struct ieee802154_addr devaddr = *addr;
u8 key_id_mode = hdr->sec.key_id_mode;
struct ieee802154_llsec_key_entry *key_entry;
struct mac802154_llsec_key *key;
if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
devaddr.mode == IEEE802154_ADDR_NONE) {
if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
devaddr.extended_addr = sec->params.coord_hwaddr;
devaddr.mode = IEEE802154_ADDR_LONG;
} else if (llsec_recover_addr(sec, &devaddr) < 0) {
return NULL;
}
}
list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
const struct ieee802154_llsec_key_id *id = &key_entry->id;
if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
continue;
if (id->mode != key_id_mode)
continue;
if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
if (ieee802154_addr_equal(&devaddr, &id->device_addr))
goto found;
} else {
if (id->id != hdr->sec.key_id)
continue;
if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
(key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
id->short_source == hdr->sec.short_src) ||
(key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
id->extended_source == hdr->sec.extended_src))
goto found;
}
}
return NULL;
found:
key = container_of(key_entry->key, struct mac802154_llsec_key, key);
if (key_id)
*key_id = key_entry->id;
return llsec_key_get(key);
}
static void llsec_geniv(u8 iv[16], __le64 addr,
const struct ieee802154_sechdr *sec)
{
__be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
__be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
iv[0] = 1; /* L' = L - 1 = 1 */
memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
iv[13] = sec->level;
iv[14] = 0;
iv[15] = 1;
}
static int
llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key)
{
u8 iv[16];
struct scatterlist src;
struct blkcipher_desc req = {
.tfm = key->tfm0,
.info = iv,
.flags = 0,
};
llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
sg_init_one(&src, skb->data, skb->len);
return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len);
}
static struct crypto_aead*
llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
{
int i;
for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
if (crypto_aead_authsize(key->tfm[i]) == authlen)
return key->tfm[i];
BUG();
}
static int
llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key)
{
u8 iv[16];
unsigned char *data;
int authlen, assoclen, datalen, rc;
struct scatterlist src, assoc[2], dst[2];
struct aead_request *req;
authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
if (!req)
return -ENOMEM;
sg_init_table(assoc, 2);
sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
assoclen = skb->mac_len;
data = skb_mac_header(skb) + skb->mac_len;
datalen = skb_tail_pointer(skb) - data;
if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
sg_set_buf(&assoc[1], data, 0);
} else {
sg_set_buf(&assoc[1], data, datalen);
assoclen += datalen;
datalen = 0;
}
sg_init_one(&src, data, datalen);
sg_init_table(dst, 2);
sg_set_buf(&dst[0], data, datalen);
sg_set_buf(&dst[1], skb_put(skb, authlen), authlen);
aead_request_set_callback(req, 0, NULL, NULL);
aead_request_set_assoc(req, assoc, assoclen);
aead_request_set_crypt(req, &src, dst, datalen, iv);
rc = crypto_aead_encrypt(req);
kfree(req);
return rc;
}
static int llsec_do_encrypt(struct sk_buff *skb,
const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key)
{
if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
return llsec_do_encrypt_unauth(skb, sec, hdr, key);
else
return llsec_do_encrypt_auth(skb, sec, hdr, key);
}
int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
{
struct ieee802154_hdr hdr;
int rc, authlen, hlen;
struct mac802154_llsec_key *key;
u32 frame_ctr;
hlen = ieee802154_hdr_pull(skb, &hdr);
if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
return -EINVAL;
if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
skb_push(skb, hlen);
return 0;
}
authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
return -EMSGSIZE;
rcu_read_lock();
read_lock_bh(&sec->lock);
if (!sec->params.enabled) {
rc = -EINVAL;
goto fail_read;
}
key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
if (!key) {
rc = -ENOKEY;
goto fail_read;
}
read_unlock_bh(&sec->lock);
write_lock_bh(&sec->lock);
frame_ctr = be32_to_cpu(sec->params.frame_counter);
hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
if (frame_ctr == 0xFFFFFFFF) {
write_unlock_bh(&sec->lock);
llsec_key_put(key);
rc = -EOVERFLOW;
goto fail;
}
sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
write_unlock_bh(&sec->lock);
rcu_read_unlock();
skb->mac_len = ieee802154_hdr_push(skb, &hdr);
skb_reset_mac_header(skb);
rc = llsec_do_encrypt(skb, sec, &hdr, key);
llsec_key_put(key);
return rc;
fail_read:
read_unlock_bh(&sec->lock);
fail:
rcu_read_unlock();
return rc;
}
static struct mac802154_llsec_device*
llsec_lookup_dev(struct mac802154_llsec *sec,
const struct ieee802154_addr *addr)
{
struct ieee802154_addr devaddr = *addr;
struct mac802154_llsec_device *dev = NULL;
if (devaddr.mode == IEEE802154_ADDR_NONE &&
llsec_recover_addr(sec, &devaddr) < 0)
return NULL;
if (devaddr.mode == IEEE802154_ADDR_SHORT) {
u32 key = llsec_dev_hash_short(devaddr.short_addr,
devaddr.pan_id);
hash_for_each_possible_rcu(sec->devices_short, dev,
bucket_s, key) {
if (dev->dev.pan_id == devaddr.pan_id &&
dev->dev.short_addr == devaddr.short_addr)
return dev;
}
} else {
u64 key = llsec_dev_hash_long(devaddr.extended_addr);
hash_for_each_possible_rcu(sec->devices_hw, dev,
bucket_hw, key) {
if (dev->dev.hwaddr == devaddr.extended_addr)
return dev;
}
}
return NULL;
}
static int
llsec_lookup_seclevel(const struct mac802154_llsec *sec,
u8 frame_type, u8 cmd_frame_id,
struct ieee802154_llsec_seclevel *rlevel)
{
struct ieee802154_llsec_seclevel *level;
list_for_each_entry_rcu(level, &sec->table.security_levels, list) {
if (level->frame_type == frame_type &&
(frame_type != IEEE802154_FC_TYPE_MAC_CMD ||
level->cmd_frame_id == cmd_frame_id)) {
*rlevel = *level;
return 0;
}
}
return -EINVAL;
}
static int
llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key, __le64 dev_addr)
{
u8 iv[16];
unsigned char *data;
int datalen;
struct scatterlist src;
struct blkcipher_desc req = {
.tfm = key->tfm0,
.info = iv,
.flags = 0,
};
llsec_geniv(iv, dev_addr, &hdr->sec);
data = skb_mac_header(skb) + skb->mac_len;
datalen = skb_tail_pointer(skb) - data;
sg_init_one(&src, data, datalen);
return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen);
}
static int
llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key, __le64 dev_addr)
{
u8 iv[16];
unsigned char *data;
int authlen, datalen, assoclen, rc;
struct scatterlist src, assoc[2];
struct aead_request *req;
authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
llsec_geniv(iv, dev_addr, &hdr->sec);
req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
if (!req)
return -ENOMEM;
sg_init_table(assoc, 2);
sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
assoclen = skb->mac_len;
data = skb_mac_header(skb) + skb->mac_len;
datalen = skb_tail_pointer(skb) - data;
if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
sg_set_buf(&assoc[1], data, 0);
} else {
sg_set_buf(&assoc[1], data, datalen - authlen);
assoclen += datalen - authlen;
data += datalen - authlen;
datalen = authlen;
}
sg_init_one(&src, data, datalen);
aead_request_set_callback(req, 0, NULL, NULL);
aead_request_set_assoc(req, assoc, assoclen);
aead_request_set_crypt(req, &src, &src, datalen, iv);
rc = crypto_aead_decrypt(req);
kfree(req);
skb_trim(skb, skb->len - authlen);
return rc;
}
static int
llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
const struct ieee802154_hdr *hdr,
struct mac802154_llsec_key *key, __le64 dev_addr)
{
if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr);
else
return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
}
static int
llsec_update_devkey_record(struct mac802154_llsec_device *dev,
const struct ieee802154_llsec_key_id *in_key)
{
struct mac802154_llsec_device_key *devkey;
devkey = llsec_devkey_find(dev, in_key);
if (!devkey) {
struct mac802154_llsec_device_key *next;
next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
if (!next)
return -ENOMEM;
next->devkey.key_id = *in_key;
spin_lock_bh(&dev->lock);
devkey = llsec_devkey_find(dev, in_key);
if (!devkey)
list_add_rcu(&next->devkey.list, &dev->dev.keys);
else
kfree(next);
spin_unlock_bh(&dev->lock);
}
return 0;
}
static int
llsec_update_devkey_info(struct mac802154_llsec_device *dev,
const struct ieee802154_llsec_key_id *in_key,
u32 frame_counter)
{
struct mac802154_llsec_device_key *devkey = NULL;
if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) {
devkey = llsec_devkey_find(dev, in_key);
if (!devkey)
return -ENOENT;
}
if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
int rc = llsec_update_devkey_record(dev, in_key);
if (rc < 0)
return rc;
}
spin_lock_bh(&dev->lock);
if ((!devkey && frame_counter < dev->dev.frame_counter) ||
(devkey && frame_counter < devkey->devkey.frame_counter)) {
spin_unlock_bh(&dev->lock);
return -EINVAL;
}
if (devkey)
devkey->devkey.frame_counter = frame_counter + 1;
else
dev->dev.frame_counter = frame_counter + 1;
spin_unlock_bh(&dev->lock);
return 0;
}
int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
{
struct ieee802154_hdr hdr;
struct mac802154_llsec_key *key;
struct ieee802154_llsec_key_id key_id;
struct mac802154_llsec_device *dev;
struct ieee802154_llsec_seclevel seclevel;
int err;
__le64 dev_addr;
u32 frame_ctr;
if (ieee802154_hdr_peek(skb, &hdr) < 0)
return -EINVAL;
if (!hdr.fc.security_enabled)
return 0;
if (hdr.fc.version == 0)
return -EINVAL;
read_lock_bh(&sec->lock);
if (!sec->params.enabled) {
read_unlock_bh(&sec->lock);
return -EINVAL;
}
read_unlock_bh(&sec->lock);
rcu_read_lock();
key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id);
if (!key) {
err = -ENOKEY;
goto fail;
}
dev = llsec_lookup_dev(sec, &hdr.source);
if (!dev) {
err = -EINVAL;
goto fail_dev;
}
if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) {
err = -EINVAL;
goto fail_dev;
}
if (!(seclevel.sec_levels & BIT(hdr.sec.level)) &&
(hdr.sec.level == 0 && seclevel.device_override &&
!dev->dev.seclevel_exempt)) {
err = -EINVAL;
goto fail_dev;
}
frame_ctr = le32_to_cpu(hdr.sec.frame_counter);
if (frame_ctr == 0xffffffff) {
err = -EOVERFLOW;
goto fail_dev;
}
err = llsec_update_devkey_info(dev, &key_id, frame_ctr);
if (err)
goto fail_dev;
dev_addr = dev->dev.hwaddr;
rcu_read_unlock();
err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr);
llsec_key_put(key);
return err;
fail_dev:
llsec_key_put(key);
fail:
rcu_read_unlock();
return err;
}
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