From 300acfdec916be696373864226267b11302d3b84 Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Wed, 31 Dec 2014 14:43:16 -0800 Subject: [PATCH] Bluetooth: Introduce force_bredr_smp debugfs option for testing Testing cross-transport pairing that starts on BR/EDR is only valid when using a controller with BR/EDR Secure Connections. Devices will indicate this by providing BR/EDR SMP fixed channel over L2CAP. To allow testing of this feature on Bluetooth 4.0 controller or controllers without the BR/EDR Secure Connections features, introduce a force_bredr_smp debugfs option that allows faking the required AES connection. Signed-off-by: Marcel Holtmann Signed-off-by: Johan Hedberg --- include/net/bluetooth/hci.h | 1 + net/bluetooth/l2cap_core.c | 2 +- net/bluetooth/smp.c | 78 +++++++++++++++++++++++++++++++++++-- 3 files changed, 76 insertions(+), 5 deletions(-) diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index 1849a437f6e1..fddb93f168b8 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -174,6 +174,7 @@ enum { HCI_DUT_MODE, HCI_FORCE_SC, HCI_FORCE_LESC, + HCI_FORCE_BREDR_SMP, HCI_FORCE_STATIC_ADDR, }; diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index d04dc0095736..11029b212874 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -6968,7 +6968,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) if (test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags) && (bredr_sc_enabled(hcon->hdev) || - test_bit(HCI_FORCE_LESC, &hcon->hdev->dbg_flags))) + test_bit(HCI_FORCE_BREDR_SMP, &hcon->hdev->dbg_flags))) conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR; mutex_init(&conn->ident_lock); diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 358264c0e785..73643a6ca3cf 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -20,6 +20,7 @@ SOFTWARE IS DISCLAIMED. */ +#include #include #include #include @@ -1675,7 +1676,7 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) if (conn->hcon->type == ACL_LINK) { /* We must have a BR/EDR SC link */ if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && - !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags)) + !test_bit(HCI_FORCE_BREDR_SMP, &hdev->dbg_flags)) return SMP_CROSS_TRANSP_NOT_ALLOWED; set_bit(SMP_FLAG_SC, &smp->flags); @@ -2738,7 +2739,7 @@ static void bredr_pairing(struct l2cap_chan *chan) /* BR/EDR must use Secure Connections for SMP */ if (!test_bit(HCI_CONN_AES_CCM, &hcon->flags) && - !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags)) + !test_bit(HCI_FORCE_BREDR_SMP, &hdev->dbg_flags)) return; /* If our LE support is not enabled don't do anything */ @@ -2976,6 +2977,66 @@ static void smp_del_chan(struct l2cap_chan *chan) l2cap_chan_put(chan); } +static ssize_t force_bredr_smp_read(struct file *file, + char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct hci_dev *hdev = file->private_data; + char buf[3]; + + buf[0] = test_bit(HCI_FORCE_BREDR_SMP, &hdev->dbg_flags) ? 'Y': 'N'; + buf[1] = '\n'; + buf[2] = '\0'; + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static ssize_t force_bredr_smp_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)); + bool enable; + + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + + buf[buf_size] = '\0'; + if (strtobool(buf, &enable)) + return -EINVAL; + + if (enable == test_bit(HCI_FORCE_BREDR_SMP, &hdev->dbg_flags)) + return -EALREADY; + + if (enable) { + struct l2cap_chan *chan; + + chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); + if (IS_ERR(chan)) + return PTR_ERR(chan); + + hdev->smp_bredr_data = chan; + } else { + struct l2cap_chan *chan; + + chan = hdev->smp_bredr_data; + hdev->smp_bredr_data = NULL; + smp_del_chan(chan); + } + + change_bit(HCI_FORCE_BREDR_SMP, &hdev->dbg_flags); + + return count; +} + +static const struct file_operations force_bredr_smp_fops = { + .open = simple_open, + .read = force_bredr_smp_read, + .write = force_bredr_smp_write, + .llseek = default_llseek, +}; + int smp_register(struct hci_dev *hdev) { struct l2cap_chan *chan; @@ -2988,9 +3049,18 @@ int smp_register(struct hci_dev *hdev) hdev->smp_data = chan; - if (!lmp_sc_capable(hdev) && - !test_bit(HCI_FORCE_LESC, &hdev->dbg_flags)) + /* If the controller does not support BR/EDR Secure Connections + * feature, then the BR/EDR SMP channel shall not be present. + * + * To test this with Bluetooth 4.0 controllers, create a debugfs + * switch that allows forcing BR/EDR SMP support and accepting + * cross-transport pairing on non-AES encrypted connections. + */ + if (!lmp_sc_capable(hdev)) { + debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs, + hdev, &force_bredr_smp_fops); return 0; + } chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR); if (IS_ERR(chan)) { -- 2.20.1