Bluetooth: Add debugfs support for max LE encryption key size

This patch adds a debugfs control to set a different maximum LE
encryption key size. This is useful for testing that implementation of
the encryption key size handling is behaving correctly.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Johan Hedberg 2015-06-11 13:52:26 +03:00 committed by Marcel Holtmann
parent 835a6a2f86
commit 2fd36558f0

View File

@ -33,6 +33,9 @@
#include "ecc.h"
#include "smp.h"
#define SMP_DEV(hdev) \
((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data)
/* Low-level debug macros to be used for stuff that we don't want
* accidentially in dmesg, i.e. the values of the various crypto keys
* and the inputs & outputs of crypto functions.
@ -81,6 +84,8 @@ struct smp_dev {
u8 local_rand[16];
bool debug_key;
u8 max_key_size;
struct crypto_blkcipher *tfm_aes;
struct crypto_hash *tfm_cmac;
};
@ -708,7 +713,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
if (rsp == NULL) {
req->io_capability = conn->hcon->io_capability;
req->oob_flag = oob_flag;
req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
req->max_key_size = SMP_DEV(hdev)->max_key_size;
req->init_key_dist = local_dist;
req->resp_key_dist = remote_dist;
req->auth_req = (authreq & AUTH_REQ_MASK(hdev));
@ -719,7 +724,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
rsp->io_capability = conn->hcon->io_capability;
rsp->oob_flag = oob_flag;
rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
rsp->max_key_size = SMP_DEV(hdev)->max_key_size;
rsp->init_key_dist = req->init_key_dist & remote_dist;
rsp->resp_key_dist = req->resp_key_dist & local_dist;
rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev));
@ -730,10 +735,11 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
{
struct l2cap_chan *chan = conn->smp;
struct hci_dev *hdev = conn->hcon->hdev;
struct smp_chan *smp = chan->data;
if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
(max_key_size < SMP_MIN_ENC_KEY_SIZE))
if (max_key_size > SMP_DEV(hdev)->max_key_size ||
max_key_size < SMP_MIN_ENC_KEY_SIZE)
return SMP_ENC_KEY_SIZE;
smp->enc_key_size = max_key_size;
@ -3130,6 +3136,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
smp->tfm_aes = tfm_aes;
smp->tfm_cmac = tfm_cmac;
smp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
create_chan:
chan = l2cap_chan_create();
@ -3252,6 +3259,49 @@ static const struct file_operations force_bredr_smp_fops = {
.llseek = default_llseek,
};
static ssize_t le_max_key_size_read(struct file *file,
char __user *user_buf,
size_t count, loff_t *ppos)
{
struct hci_dev *hdev = file->private_data;
char buf[4];
snprintf(buf, sizeof(buf), "%2u\n", SMP_DEV(hdev)->max_key_size);
return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
}
static ssize_t le_max_key_size_write(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct hci_dev *hdev = file->private_data;
char buf[32];
size_t buf_size = min(count, (sizeof(buf) - 1));
u8 key_size;
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
buf[buf_size] = '\0';
sscanf(buf, "%hhu", &key_size);
if (key_size > SMP_MAX_ENC_KEY_SIZE || key_size < SMP_MIN_ENC_KEY_SIZE)
return -EINVAL;
SMP_DEV(hdev)->max_key_size = key_size;
return count;
}
static const struct file_operations le_max_key_size_fops = {
.open = simple_open,
.read = le_max_key_size_read,
.write = le_max_key_size_write,
.llseek = default_llseek,
};
int smp_register(struct hci_dev *hdev)
{
struct l2cap_chan *chan;
@ -3276,6 +3326,9 @@ int smp_register(struct hci_dev *hdev)
hdev->smp_data = chan;
debugfs_create_file("le_max_key_size", 0644, hdev->debugfs, hdev,
&le_max_key_size_fops);
/* If the controller does not support BR/EDR Secure Connections
* feature, then the BR/EDR SMP channel shall not be present.
*