Bluetooth: Add set_io_capability management command

This patch adds a new set_io_capability management command which is used
to set the IO capability for Secure Simple Pairing (SSP) as well as the
Security Manager Protocol (SMP). The value is per hci_dev and each
hci_conn object inherits it upon creation.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

include/net/bluetooth/hci.h

@@ -402,6 +402,14 @@ struct hci_cp_reject_sync_conn_req {
 	__u8     reason;
 } __packed;
 
+#define HCI_OP_IO_CAPABILITY_REPLY	0x042b
+struct hci_cp_io_capability_reply {
+	bdaddr_t bdaddr;
+	__u8     capability;
+	__u8     oob_data;
+	__u8     authentication;
+} __packed;
+
 #define HCI_OP_IO_CAPABILITY_NEG_REPLY	0x0434
 struct hci_cp_io_capability_neg_reply {
 	bdaddr_t bdaddr;

include/net/bluetooth/hci_core.h

@@ -106,6 +106,7 @@ struct hci_dev {
 	__u16		manufacturer;
 	__le16		lmp_subver;
 	__u16		voice_setting;
+	__u8		io_capability;
 
 	__u16		pkt_type;
 	__u16		esco_type;
@@ -214,6 +215,7 @@ struct hci_conn {
 	__u8             sec_level;
 	__u8		 pending_sec_level;
 	__u8		 pin_length;
+	__u8		 io_capability;
 	__u8             power_save;
 	__u16            disc_timeout;
 	unsigned long	 pend;

include/net/bluetooth/mgmt.h

@@ -154,6 +154,12 @@ struct mgmt_cp_pin_code_neg_reply {
 	bdaddr_t bdaddr;
 } __packed;
 
+#define MGMT_OP_SET_IO_CAPABILITY	0x0013
+struct mgmt_cp_set_io_capability {
+	__le16 index;
+	__u8 io_capability;
+} __packed;
+
 #define MGMT_EV_CMD_COMPLETE		0x0001
 struct mgmt_ev_cmd_complete {
 	__le16 opcode;

net/bluetooth/hci_conn.c

@@ -234,6 +234,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 	conn->mode  = HCI_CM_ACTIVE;
 	conn->state = BT_OPEN;
 	conn->auth_type = HCI_AT_GENERAL_BONDING;
+	conn->io_capability = hdev->io_capability;
 
 	conn->power_save = 1;
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;

net/bluetooth/hci_core.c

@@ -1084,6 +1084,7 @@ int hci_register_dev(struct hci_dev *hdev)
 	hdev->pkt_type  = (HCI_DM1 | HCI_DH1 | HCI_HV1);
 	hdev->esco_type = (ESCO_HV1);
 	hdev->link_mode = (HCI_LM_ACCEPT);
+	hdev->io_capability = 0x03; /* No Input No Output */
 
 	hdev->idle_timeout = 0;
 	hdev->sniff_max_interval = 800;

net/bluetooth/hci_event.c

@@ -2198,6 +2198,25 @@ static inline void hci_extended_inquiry_result_evt(struct hci_dev *hdev, struct
 	hci_dev_unlock(hdev);
 }
 
+static inline u8 hci_get_auth_req(struct hci_conn *conn)
+{
+	/* If remote requests dedicated bonding follow that lead */
+	if (conn->remote_auth == 0x02 || conn->remote_auth == 0x03) {
+		/* If both remote and local IO capabilities allow MITM
+		 * protection then require it, otherwise don't */
+		if (conn->remote_cap == 0x03 || conn->io_capability == 0x03)
+			return 0x02;
+		else
+			return 0x03;
+	}
+
+	/* If remote requests no-bonding follow that lead */
+	if (conn->remote_auth == 0x00 || conn->remote_auth == 0x01)
+		return 0x00;
+
+	return conn->auth_type;
+}
+
 static inline void hci_io_capa_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_io_capa_request *ev = (void *) skb->data;
@@ -2218,8 +2237,15 @@ static inline void hci_io_capa_request_evt(struct hci_dev *hdev, struct sk_buff
 
 	if (test_bit(HCI_PAIRABLE, &hdev->flags) ||
 			(conn->remote_auth & ~0x01) == HCI_AT_NO_BONDING) {
-		/* FIXME: Do IO capa response based on information
-		 * provided through the management interface */
+		struct hci_cp_io_capability_reply cp;
+
+		bacpy(&cp.bdaddr, &ev->bdaddr);
+		cp.capability = conn->io_capability;
+		cp.oob_data = 0;
+		cp.authentication = hci_get_auth_req(conn);
+
+		hci_send_cmd(hdev, HCI_OP_IO_CAPABILITY_REPLY,
+							sizeof(cp), &cp);
 	} else {
 		struct hci_cp_io_capability_neg_reply cp;
 

net/bluetooth/mgmt.c

@@ -1016,6 +1016,35 @@ static int pin_code_neg_reply(struct sock *sk, unsigned char *data, u16 len)
 	return err;
 }
 
+static int set_io_capability(struct sock *sk, unsigned char *data, u16 len)
+{
+	struct hci_dev *hdev;
+	struct mgmt_cp_set_io_capability *cp;
+	u16 dev_id;
+
+	BT_DBG("");
+
+	cp = (void *) data;
+	dev_id = get_unaligned_le16(&cp->index);
+
+	hdev = hci_dev_get(dev_id);
+	if (!hdev)
+		return cmd_status(sk, MGMT_OP_SET_IO_CAPABILITY, ENODEV);
+
+	hci_dev_lock_bh(hdev);
+
+	hdev->io_capability = cp->io_capability;
+
+	BT_DBG("%s IO capability set to 0x%02x", hdev->name,
+						hdev->io_capability);
+
+	hci_dev_unlock_bh(hdev);
+	hci_dev_put(hdev);
+
+	return cmd_complete(sk, MGMT_OP_SET_IO_CAPABILITY,
+						&dev_id, sizeof(dev_id));
+}
+
 int mgmt_control(struct sock *sk, struct msghdr *msg, size_t msglen)
 {
 	unsigned char *buf;
@@ -1098,6 +1127,9 @@ int mgmt_control(struct sock *sk, struct msghdr *msg, size_t msglen)
 	case MGMT_OP_PIN_CODE_NEG_REPLY:
 		err = pin_code_neg_reply(sk, buf + sizeof(*hdr), len);
 		break;
+	case MGMT_OP_SET_IO_CAPABILITY:
+		err = set_io_capability(sk, buf + sizeof(*hdr), len);
+		break;
 	default:
 		BT_DBG("Unknown op %u", opcode);
 		err = cmd_status(sk, opcode, 0x01);