linux/net/bluetooth/smp.h

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/*
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_DIST_LINK_KEY 0x08
#define SMP_AUTH_NONE 0x00
#define SMP_AUTH_BONDING 0x01
#define SMP_AUTH_MITM 0x04
#define SMP_AUTH_SC 0x08
#define SMP_AUTH_KEYPRESS 0x10
#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_PUBLIC_KEY 0x0c
struct smp_cmd_public_key {
__u8 x[32];
__u8 y[32];
} __packed;
#define SMP_CMD_DHKEY_CHECK 0x0d
struct smp_cmd_dhkey_check {
__u8 e[16];
} __packed;
#define SMP_CMD_KEYPRESS_NOTIFY 0x0e
struct smp_cmd_keypress_notify {
__u8 value;
} __packed;
#define SMP_CMD_MAX 0x0e
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>
2014-09-05 19:19:55 +00:00
#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_DHKEY_CHECK_FAILED 0x0b
#define SMP_NUMERIC_COMP_FAILED 0x0c
#define SMP_BREDR_PAIRING_IN_PROGRESS 0x0d
#define SMP_CROSS_TRANSP_NOT_ALLOWED 0x0e
#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_LTK_P256,
SMP_LTK_P256_DEBUG,
};
static inline bool smp_ltk_is_sc(struct smp_ltk *key)
{
switch (key->type) {
case SMP_LTK_P256:
case SMP_LTK_P256_DEBUG:
return true;
}
return false;
}
static inline u8 smp_ltk_sec_level(struct smp_ltk *key)
{
if (key->authenticated) {
if (smp_ltk_is_sc(key))
return BT_SECURITY_FIPS;
else
return BT_SECURITY_HIGH;
}
return BT_SECURITY_MEDIUM;
}
/* Key preferences for smp_sufficient security */
enum smp_key_pref {
SMP_ALLOW_STK,
SMP_USE_LTK,
};
/* SMP Commands */
Bluetooth: Fix crash in SMP when unpairing When unpairing the keys stored in hci_dev are removed. If SMP is ongoing the SMP context will also have references to these keys, so removing them from the hci_dev lists will make the pointers invalid. This can result in the following type of crashes: BUG: unable to handle kernel paging request at 6b6b6b6b IP: [<c11f26be>] __list_del_entry+0x44/0x71 *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: hci_uart btqca btusb btintel btbcm btrtl hci_vhci rfcomm bluetooth_6lowpan bluetooth CPU: 0 PID: 723 Comm: kworker/u5:0 Not tainted 4.3.0-rc3+ #1379 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 Workqueue: hci0 hci_rx_work [bluetooth] task: f19da940 ti: f1a94000 task.ti: f1a94000 EIP: 0060:[<c11f26be>] EFLAGS: 00010202 CPU: 0 EIP is at __list_del_entry+0x44/0x71 EAX: c0088d20 EBX: f30fcac0 ECX: 6b6b6b6b EDX: 6b6b6b6b ESI: f4b60000 EDI: c0088d20 EBP: f1a95d90 ESP: f1a95d8c DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 CR0: 8005003b CR2: 6b6b6b6b CR3: 319e5000 CR4: 00000690 Stack: f30fcac0 f1a95db0 f82dc3e1 f1bfc000 00000000 c106524f f1bfc000 f30fd020 f1a95dc0 f1a95dd0 f82dcbdb f1a95de0 f82dcbdb 00000067 f1bfc000 f30fd020 f1a95de0 f1a95df0 f82d1126 00000067 f82d1126 00000006 f30fd020 f1bfc000 Call Trace: [<f82dc3e1>] smp_chan_destroy+0x192/0x240 [bluetooth] [<c106524f>] ? trace_hardirqs_on_caller+0x14e/0x169 [<f82dcbdb>] smp_teardown_cb+0x47/0x64 [bluetooth] [<f82dcbdb>] ? smp_teardown_cb+0x47/0x64 [bluetooth] [<f82d1126>] l2cap_chan_del+0x5d/0x14d [bluetooth] [<f82d1126>] ? l2cap_chan_del+0x5d/0x14d [bluetooth] [<f82d40ef>] l2cap_conn_del+0x109/0x17b [bluetooth] [<f82d40ef>] ? l2cap_conn_del+0x109/0x17b [bluetooth] [<f82c0205>] ? hci_event_packet+0x5b1/0x2092 [bluetooth] [<f82d41aa>] l2cap_disconn_cfm+0x49/0x50 [bluetooth] [<f82d41aa>] ? l2cap_disconn_cfm+0x49/0x50 [bluetooth] [<f82c0228>] hci_event_packet+0x5d4/0x2092 [bluetooth] [<c1332c16>] ? skb_release_data+0x6a/0x95 [<f82ce5d4>] ? hci_send_to_monitor+0xe7/0xf4 [bluetooth] [<c1409708>] ? _raw_spin_unlock_irqrestore+0x44/0x57 [<f82b3bb0>] hci_rx_work+0xf1/0x28b [bluetooth] [<f82b3bb0>] ? hci_rx_work+0xf1/0x28b [bluetooth] [<c10635a0>] ? __lock_is_held+0x2e/0x44 [<c104772e>] process_one_work+0x232/0x432 [<c1071ddc>] ? rcu_read_lock_sched_held+0x50/0x5a [<c104772e>] ? process_one_work+0x232/0x432 [<c1047d48>] worker_thread+0x1b8/0x255 [<c1047b90>] ? rescuer_thread+0x23c/0x23c [<c104bb71>] kthread+0x91/0x96 [<c14096a7>] ? _raw_spin_unlock_irq+0x27/0x44 [<c1409d61>] ret_from_kernel_thread+0x21/0x30 [<c104bae0>] ? kthread_parkme+0x1e/0x1e To solve the issue, introduce a new smp_cancel_pairing() API that can be used to clean up the SMP state before touching the hci_dev lists. Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2015-10-22 06:38:35 +00:00
void smp_cancel_pairing(struct hci_conn *hcon);
bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
enum smp_key_pref key_pref);
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, const u8 irk[16],
const bdaddr_t *bdaddr);
int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa);
int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]);
int smp_register(struct hci_dev *hdev);
void smp_unregister(struct hci_dev *hdev);
#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
int bt_selftest_smp(void);
#else
static inline int bt_selftest_smp(void)
{
return 0;
}
#endif
#endif /* __SMP_H */