This will allow using the crypto subsystem for encrypting data. As SMP
(Security Manager Protocol) is implemented almost entirely on the host
side and the crypto module already implements the needed methods
(AES-128), it makes sense to use it.
This patch also adds a new Kconfig option to toggle the SMP support.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxxxxxx>
Signed-off-by: Anderson Briglia <anderson.briglia@xxxxxxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 2 ++
net/bluetooth/Kconfig | 6 ++++++
net/bluetooth/hci_core.c | 22 ++++++++++++++++++++++
net/bluetooth/smp.c | 17 +++++++++++++++--
4 files changed, 45 insertions(+), 2 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index d5d8454..e8dbde8 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -161,6 +161,8 @@ struct hci_dev {
__u16 init_last_cmd;
+ struct crypto_blkcipher *tfm;
+
struct inquiry_cache inq_cache;
struct hci_conn_hash conn_hash;
struct list_head blacklist;
diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
index c6f9c2f..e9f40af 100644
--- a/net/bluetooth/Kconfig
+++ b/net/bluetooth/Kconfig
@@ -22,6 +22,7 @@ menuconfig BT
BNEP Module (Bluetooth Network Encapsulation Protocol)
CMTP Module (CAPI Message Transport Protocol)
HIDP Module (Human Interface Device Protocol)
+ SMP Module (Security Manager Protocol)
Say Y here to compile Bluetooth support into the kernel or say M to
compile it as module (bluetooth).
@@ -35,11 +36,16 @@ config BT_L2CAP
bool "L2CAP protocol support"
depends on BT
select CRC16
+ select CRYPTO_BLKCIPHER
+ select CRYPTO_AES
help
L2CAP (Logical Link Control and Adaptation Protocol) provides
connection oriented and connection-less data transport. L2CAP
support is required for most Bluetooth applications.
+ Also included is support for SMP (Security Manager Protocol) which
+ is the security layer on top of LE (Low Energy) links.
+
config BT_SCO
bool "SCO links support"
depends on BT
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index b372fb8..ff67843 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -42,6 +42,7 @@
#include <linux/notifier.h>
#include <linux/rfkill.h>
#include <linux/timer.h>
+#include <linux/crypto.h>
#include <net/sock.h>
#include <asm/system.h>
@@ -60,6 +61,8 @@ static void hci_notify(struct hci_dev *hdev, int event);
static DEFINE_RWLOCK(hci_task_lock);
+static int enable_smp;
+
/* HCI device list */
LIST_HEAD(hci_dev_list);
DEFINE_RWLOCK(hci_dev_list_lock);
@@ -1077,6 +1080,14 @@ static void hci_cmd_timer(unsigned long arg)
tasklet_schedule(&hdev->cmd_task);
}
+static struct crypto_blkcipher *alloc_cypher(void)
+{
+ if (enable_smp)
+ return crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
+
+ return ERR_PTR(-ENOTSUPP);
+}
+
/* Register HCI device */
int hci_register_dev(struct hci_dev *hdev)
{
@@ -1155,6 +1166,11 @@ int hci_register_dev(struct hci_dev *hdev)
if (!hdev->workqueue)
goto nomem;
+ hdev->tfm = alloc_cypher();
+ if (IS_ERR(hdev->tfm))
+ BT_INFO("Failed to load transform for ecb(aes): %ld",
+ PTR_ERR(hdev->tfm));
+
hci_register_sysfs(hdev);
hdev->rfkill = rfkill_alloc(hdev->name, &hdev->dev,
@@ -1203,6 +1219,9 @@ int hci_unregister_dev(struct hci_dev *hdev)
!test_bit(HCI_SETUP, &hdev->flags))
mgmt_index_removed(hdev->id);
+ if (!IS_ERR(hdev->tfm))
+ crypto_free_blkcipher(hdev->tfm);
+
hci_notify(hdev, HCI_DEV_UNREG);
if (hdev->rfkill) {
@@ -2037,3 +2056,6 @@ static void hci_cmd_task(unsigned long arg)
}
}
}
+
+module_param(enable_smp, bool, 0644);
+MODULE_PARM_DESC(enable_smp, "Enable SMP support (LE only)");
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 0d04c7a..7f275bf 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -157,6 +157,9 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
BT_DBG("conn %p hcon %p level 0x%2.2x", conn, conn->hcon, sec_level);
+ if (IS_ERR(conn->hcon->hdev->tfm))
+ return PTR_ERR(conn->hcon->hdev->tfm);
+
switch (sec_level) {
case BT_SECURITY_MEDIUM:
/* Encrypted, no MITM protection */
@@ -197,6 +200,12 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
__u8 reason;
int err = 0;
+ if (IS_ERR(conn->hcon->hdev->tfm)) {
+ err = PTR_ERR(conn->hcon->hdev->tfm);
+ reason = SMP_PAIRING_NOTSUPP;
+ goto done;
+ }
+
skb_pull(skb, sizeof(code));
switch (code) {
@@ -232,11 +241,15 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("Unknown command code 0x%2.2x", code);
reason = SMP_CMD_NOTSUPP;
- smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
- &reason);
err = -EOPNOTSUPP;
+ goto done;
}
+done:
+ if (reason)
+ smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
+ &reason);
+
kfree_skb(skb);
return err;
}
--
1.7.4.1
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