kernel-fxtec-pro1x/net/bluetooth/smp.h
Johan Hedberg b28b494366 Bluetooth: Add strict checks for allowed SMP PDUs
SMP defines quite clearly when certain PDUs are to be expected/allowed
and when not, but doesn't have any explicit request/response definition.
So far the code has relied on each PDU handler to behave correctly if
receiving PDUs at an unexpected moment, however this requires many
different checks and is prone to errors.

This patch introduces a generic way to keep track of allowed PDUs and
thereby reduces the responsibility & load on individual command
handlers. The tracking is implemented using a simple bit-mask where each
opcode maps to its own bit. If the bit is set the corresponding PDU is
allow and if the bit is not set the PDU is not allowed.

As a simple example, when we send the Pairing Request we'd set the bit
for Pairing Response, and when we receive the Pairing Response we'd
clear the bit for Pairing Response.

Since the disallowed PDU rejection is now done in a single central place
we need to be a bit careful of which action makes most sense to all
cases. Previously some, such as Security Request, have been simply
ignored whereas others have caused an explicit disconnect.

The only PDU rejection action that keeps good interoperability and can
be used for all the applicable use cases is to drop the data. This may
raise some concerns of us now being more lenient for misbehaving (and
potentially malicious) devices, but the policy of simply dropping data
has been a successful one for many years e.g. in L2CAP (where this is
the *only* policy for such cases - we never request disconnection in
l2cap_core.c because of bad data). Furthermore, we cannot prevent
connected devices from creating the SMP context (through a Security or
Pairing Request), and once the context exists looking up the
corresponding bit for the received opcode and deciding to reject it is
essentially an equally lightweight operation as the kind of rejection
that l2cap_core.c already successfully does.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2014-09-08 19:07:56 +02:00

139 lines
3.6 KiB
C

/*
BlueZ - Bluetooth protocol stack for Linux
Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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;
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
SOFTWARE IS DISCLAIMED.
*/
#ifndef __SMP_H
#define __SMP_H
struct smp_command_hdr {
__u8 code;
} __packed;
#define SMP_CMD_PAIRING_REQ 0x01
#define SMP_CMD_PAIRING_RSP 0x02
struct smp_cmd_pairing {
__u8 io_capability;
__u8 oob_flag;
__u8 auth_req;
__u8 max_key_size;
__u8 init_key_dist;
__u8 resp_key_dist;
} __packed;
#define SMP_IO_DISPLAY_ONLY 0x00
#define SMP_IO_DISPLAY_YESNO 0x01
#define SMP_IO_KEYBOARD_ONLY 0x02
#define SMP_IO_NO_INPUT_OUTPUT 0x03
#define SMP_IO_KEYBOARD_DISPLAY 0x04
#define SMP_OOB_NOT_PRESENT 0x00
#define SMP_OOB_PRESENT 0x01
#define SMP_DIST_ENC_KEY 0x01
#define SMP_DIST_ID_KEY 0x02
#define SMP_DIST_SIGN 0x04
#define SMP_AUTH_NONE 0x00
#define SMP_AUTH_BONDING 0x01
#define SMP_AUTH_MITM 0x04
#define SMP_CMD_PAIRING_CONFIRM 0x03
struct smp_cmd_pairing_confirm {
__u8 confirm_val[16];
} __packed;
#define SMP_CMD_PAIRING_RANDOM 0x04
struct smp_cmd_pairing_random {
__u8 rand_val[16];
} __packed;
#define SMP_CMD_PAIRING_FAIL 0x05
struct smp_cmd_pairing_fail {
__u8 reason;
} __packed;
#define SMP_CMD_ENCRYPT_INFO 0x06
struct smp_cmd_encrypt_info {
__u8 ltk[16];
} __packed;
#define SMP_CMD_MASTER_IDENT 0x07
struct smp_cmd_master_ident {
__le16 ediv;
__le64 rand;
} __packed;
#define SMP_CMD_IDENT_INFO 0x08
struct smp_cmd_ident_info {
__u8 irk[16];
} __packed;
#define SMP_CMD_IDENT_ADDR_INFO 0x09
struct smp_cmd_ident_addr_info {
__u8 addr_type;
bdaddr_t bdaddr;
} __packed;
#define SMP_CMD_SIGN_INFO 0x0a
struct smp_cmd_sign_info {
__u8 csrk[16];
} __packed;
#define SMP_CMD_SECURITY_REQ 0x0b
struct smp_cmd_security_req {
__u8 auth_req;
} __packed;
#define SMP_CMD_MAX 0x0b
#define SMP_PASSKEY_ENTRY_FAILED 0x01
#define SMP_OOB_NOT_AVAIL 0x02
#define SMP_AUTH_REQUIREMENTS 0x03
#define SMP_CONFIRM_FAILED 0x04
#define SMP_PAIRING_NOTSUPP 0x05
#define SMP_ENC_KEY_SIZE 0x06
#define SMP_CMD_NOTSUPP 0x07
#define SMP_UNSPECIFIED 0x08
#define SMP_REPEATED_ATTEMPTS 0x09
#define SMP_INVALID_PARAMS 0x0a
#define SMP_MIN_ENC_KEY_SIZE 7
#define SMP_MAX_ENC_KEY_SIZE 16
/* LTK types used in internal storage (struct smp_ltk) */
enum {
SMP_STK,
SMP_LTK,
SMP_LTK_SLAVE,
};
/* SMP Commands */
bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level);
int smp_conn_security(struct hci_conn *hcon, __u8 sec_level);
int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey);
bool smp_irk_matches(struct hci_dev *hdev, u8 irk[16], bdaddr_t *bdaddr);
int smp_generate_rpa(struct hci_dev *hdev, u8 irk[16], bdaddr_t *rpa);
int smp_register(struct hci_dev *hdev);
void smp_unregister(struct hci_dev *hdev);
#endif /* __SMP_H */