android_kernel_xiaomi_sm8350/net/bluetooth/hci_conn.c
Marcel Holtmann a67e899cf3 Bluetooth: Fix issue with sysfs handling for connections
Due to a semantic changes in flush_workqueue() the current approach of
synchronizing the sysfs handling for connections doesn't work anymore. The
whole approach is actually fully broken and based on assumptions that are
no longer valid.

With the introduction of Simple Pairing support, the creation of low-level
ACL links got changed. This change invalidates the reason why in the past
two independent work queues have been used for adding/removing sysfs
devices. The adding of the actual sysfs device is now postponed until the
host controller successfully assigns an unique handle to that link. So
the real synchronization happens inside the controller and not the host.

The only left-over problem is that some internals of the sysfs device
handling are not initialized ahead of time. This leaves potential access
to invalid data and can cause various NULL pointer dereferences. To fix
this a new function makes sure that all sysfs details are initialized
when an connection attempt is made. The actual sysfs device is only
registered when the connection has been successfully established. To
avoid a race condition with the registration, the check if a device is
registered has been moved into the removal work.

As an extra protection two flush_work() calls are left in place to
make sure a previous add/del work has been completed first.

Based on a report by Marc Pignat <marc.pignat@hevs.ch>

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Justin P. Mattock <justinmattock@gmail.com>
Tested-by: Roger Quadros <ext-roger.quadros@nokia.com>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
2009-05-04 14:29:02 -07:00

687 lines
15 KiB
C

/*
BlueZ - Bluetooth protocol stack for Linux
Copyright (C) 2000-2001 Qualcomm Incorporated
Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
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.
*/
/* Bluetooth HCI connection handling. */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <net/sock.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
void hci_acl_connect(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
struct inquiry_entry *ie;
struct hci_cp_create_conn cp;
BT_DBG("%p", conn);
conn->state = BT_CONNECT;
conn->out = 1;
conn->link_mode = HCI_LM_MASTER;
conn->attempt++;
conn->link_policy = hdev->link_policy;
memset(&cp, 0, sizeof(cp));
bacpy(&cp.bdaddr, &conn->dst);
cp.pscan_rep_mode = 0x02;
if ((ie = hci_inquiry_cache_lookup(hdev, &conn->dst))) {
if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
cp.pscan_rep_mode = ie->data.pscan_rep_mode;
cp.pscan_mode = ie->data.pscan_mode;
cp.clock_offset = ie->data.clock_offset |
cpu_to_le16(0x8000);
}
memcpy(conn->dev_class, ie->data.dev_class, 3);
conn->ssp_mode = ie->data.ssp_mode;
}
cp.pkt_type = cpu_to_le16(conn->pkt_type);
if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
cp.role_switch = 0x01;
else
cp.role_switch = 0x00;
hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
}
static void hci_acl_connect_cancel(struct hci_conn *conn)
{
struct hci_cp_create_conn_cancel cp;
BT_DBG("%p", conn);
if (conn->hdev->hci_ver < 2)
return;
bacpy(&cp.bdaddr, &conn->dst);
hci_send_cmd(conn->hdev, HCI_OP_CREATE_CONN_CANCEL, sizeof(cp), &cp);
}
void hci_acl_disconn(struct hci_conn *conn, __u8 reason)
{
struct hci_cp_disconnect cp;
BT_DBG("%p", conn);
conn->state = BT_DISCONN;
cp.handle = cpu_to_le16(conn->handle);
cp.reason = reason;
hci_send_cmd(conn->hdev, HCI_OP_DISCONNECT, sizeof(cp), &cp);
}
void hci_add_sco(struct hci_conn *conn, __u16 handle)
{
struct hci_dev *hdev = conn->hdev;
struct hci_cp_add_sco cp;
BT_DBG("%p", conn);
conn->state = BT_CONNECT;
conn->out = 1;
conn->attempt++;
cp.handle = cpu_to_le16(handle);
cp.pkt_type = cpu_to_le16(conn->pkt_type);
hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
}
void hci_setup_sync(struct hci_conn *conn, __u16 handle)
{
struct hci_dev *hdev = conn->hdev;
struct hci_cp_setup_sync_conn cp;
BT_DBG("%p", conn);
conn->state = BT_CONNECT;
conn->out = 1;
conn->attempt++;
cp.handle = cpu_to_le16(handle);
cp.pkt_type = cpu_to_le16(conn->pkt_type);
cp.tx_bandwidth = cpu_to_le32(0x00001f40);
cp.rx_bandwidth = cpu_to_le32(0x00001f40);
cp.max_latency = cpu_to_le16(0xffff);
cp.voice_setting = cpu_to_le16(hdev->voice_setting);
cp.retrans_effort = 0xff;
hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp);
}
static void hci_conn_timeout(unsigned long arg)
{
struct hci_conn *conn = (void *) arg;
struct hci_dev *hdev = conn->hdev;
__u8 reason;
BT_DBG("conn %p state %d", conn, conn->state);
if (atomic_read(&conn->refcnt))
return;
hci_dev_lock(hdev);
switch (conn->state) {
case BT_CONNECT:
case BT_CONNECT2:
if (conn->type == ACL_LINK)
hci_acl_connect_cancel(conn);
else
hci_acl_disconn(conn, 0x13);
break;
case BT_CONFIG:
case BT_CONNECTED:
reason = hci_proto_disconn_ind(conn);
hci_acl_disconn(conn, reason);
break;
default:
conn->state = BT_CLOSED;
break;
}
hci_dev_unlock(hdev);
}
static void hci_conn_idle(unsigned long arg)
{
struct hci_conn *conn = (void *) arg;
BT_DBG("conn %p mode %d", conn, conn->mode);
hci_conn_enter_sniff_mode(conn);
}
struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
{
struct hci_conn *conn;
BT_DBG("%s dst %s", hdev->name, batostr(dst));
conn = kzalloc(sizeof(struct hci_conn), GFP_ATOMIC);
if (!conn)
return NULL;
bacpy(&conn->dst, dst);
conn->hdev = hdev;
conn->type = type;
conn->mode = HCI_CM_ACTIVE;
conn->state = BT_OPEN;
conn->power_save = 1;
conn->disc_timeout = HCI_DISCONN_TIMEOUT;
switch (type) {
case ACL_LINK:
conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
break;
case SCO_LINK:
if (lmp_esco_capable(hdev))
conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
(hdev->esco_type & EDR_ESCO_MASK);
else
conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
break;
case ESCO_LINK:
conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
break;
}
skb_queue_head_init(&conn->data_q);
setup_timer(&conn->disc_timer, hci_conn_timeout, (unsigned long)conn);
setup_timer(&conn->idle_timer, hci_conn_idle, (unsigned long)conn);
atomic_set(&conn->refcnt, 0);
hci_dev_hold(hdev);
tasklet_disable(&hdev->tx_task);
hci_conn_hash_add(hdev, conn);
if (hdev->notify)
hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
hci_conn_init_sysfs(conn);
tasklet_enable(&hdev->tx_task);
return conn;
}
int hci_conn_del(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("%s conn %p handle %d", hdev->name, conn, conn->handle);
del_timer(&conn->idle_timer);
del_timer(&conn->disc_timer);
if (conn->type == ACL_LINK) {
struct hci_conn *sco = conn->link;
if (sco)
sco->link = NULL;
/* Unacked frames */
hdev->acl_cnt += conn->sent;
} else {
struct hci_conn *acl = conn->link;
if (acl) {
acl->link = NULL;
hci_conn_put(acl);
}
}
tasklet_disable(&hdev->tx_task);
hci_conn_hash_del(hdev, conn);
if (hdev->notify)
hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
tasklet_enable(&hdev->tx_task);
skb_queue_purge(&conn->data_q);
hci_conn_del_sysfs(conn);
return 0;
}
struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src)
{
int use_src = bacmp(src, BDADDR_ANY);
struct hci_dev *hdev = NULL;
struct list_head *p;
BT_DBG("%s -> %s", batostr(src), batostr(dst));
read_lock_bh(&hci_dev_list_lock);
list_for_each(p, &hci_dev_list) {
struct hci_dev *d = list_entry(p, struct hci_dev, list);
if (!test_bit(HCI_UP, &d->flags) || test_bit(HCI_RAW, &d->flags))
continue;
/* Simple routing:
* No source address - find interface with bdaddr != dst
* Source address - find interface with bdaddr == src
*/
if (use_src) {
if (!bacmp(&d->bdaddr, src)) {
hdev = d; break;
}
} else {
if (bacmp(&d->bdaddr, dst)) {
hdev = d; break;
}
}
}
if (hdev)
hdev = hci_dev_hold(hdev);
read_unlock_bh(&hci_dev_list_lock);
return hdev;
}
EXPORT_SYMBOL(hci_get_route);
/* Create SCO or ACL connection.
* Device _must_ be locked */
struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 sec_level, __u8 auth_type)
{
struct hci_conn *acl;
struct hci_conn *sco;
BT_DBG("%s dst %s", hdev->name, batostr(dst));
if (!(acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst))) {
if (!(acl = hci_conn_add(hdev, ACL_LINK, dst)))
return NULL;
}
hci_conn_hold(acl);
if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
acl->sec_level = sec_level;
acl->auth_type = auth_type;
hci_acl_connect(acl);
}
if (type == ACL_LINK)
return acl;
if (!(sco = hci_conn_hash_lookup_ba(hdev, type, dst))) {
if (!(sco = hci_conn_add(hdev, type, dst))) {
hci_conn_put(acl);
return NULL;
}
}
acl->link = sco;
sco->link = acl;
hci_conn_hold(sco);
if (acl->state == BT_CONNECTED &&
(sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
if (lmp_esco_capable(hdev))
hci_setup_sync(sco, acl->handle);
else
hci_add_sco(sco, acl->handle);
}
return sco;
}
EXPORT_SYMBOL(hci_connect);
/* Check link security requirement */
int hci_conn_check_link_mode(struct hci_conn *conn)
{
BT_DBG("conn %p", conn);
if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0 &&
!(conn->link_mode & HCI_LM_ENCRYPT))
return 0;
return 1;
}
EXPORT_SYMBOL(hci_conn_check_link_mode);
/* Authenticate remote device */
static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
{
BT_DBG("conn %p", conn);
if (sec_level > conn->sec_level)
conn->sec_level = sec_level;
else if (conn->link_mode & HCI_LM_AUTH)
return 1;
conn->auth_type = auth_type;
if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
struct hci_cp_auth_requested cp;
cp.handle = cpu_to_le16(conn->handle);
hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
sizeof(cp), &cp);
}
return 0;
}
/* Enable security */
int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
{
BT_DBG("conn %p", conn);
if (sec_level == BT_SECURITY_SDP)
return 1;
if (sec_level == BT_SECURITY_LOW &&
(!conn->ssp_mode || !conn->hdev->ssp_mode))
return 1;
if (conn->link_mode & HCI_LM_ENCRYPT)
return hci_conn_auth(conn, sec_level, auth_type);
if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend))
return 0;
if (hci_conn_auth(conn, sec_level, auth_type)) {
struct hci_cp_set_conn_encrypt cp;
cp.handle = cpu_to_le16(conn->handle);
cp.encrypt = 1;
hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT,
sizeof(cp), &cp);
}
return 0;
}
EXPORT_SYMBOL(hci_conn_security);
/* Change link key */
int hci_conn_change_link_key(struct hci_conn *conn)
{
BT_DBG("conn %p", conn);
if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
struct hci_cp_change_conn_link_key cp;
cp.handle = cpu_to_le16(conn->handle);
hci_send_cmd(conn->hdev, HCI_OP_CHANGE_CONN_LINK_KEY,
sizeof(cp), &cp);
}
return 0;
}
EXPORT_SYMBOL(hci_conn_change_link_key);
/* Switch role */
int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
{
BT_DBG("conn %p", conn);
if (!role && conn->link_mode & HCI_LM_MASTER)
return 1;
if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->pend)) {
struct hci_cp_switch_role cp;
bacpy(&cp.bdaddr, &conn->dst);
cp.role = role;
hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
}
return 0;
}
EXPORT_SYMBOL(hci_conn_switch_role);
/* Enter active mode */
void hci_conn_enter_active_mode(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p mode %d", conn, conn->mode);
if (test_bit(HCI_RAW, &hdev->flags))
return;
if (conn->mode != HCI_CM_SNIFF || !conn->power_save)
goto timer;
if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
struct hci_cp_exit_sniff_mode cp;
cp.handle = cpu_to_le16(conn->handle);
hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
}
timer:
if (hdev->idle_timeout > 0)
mod_timer(&conn->idle_timer,
jiffies + msecs_to_jiffies(hdev->idle_timeout));
}
/* Enter sniff mode */
void hci_conn_enter_sniff_mode(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p mode %d", conn, conn->mode);
if (test_bit(HCI_RAW, &hdev->flags))
return;
if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
return;
if (conn->mode != HCI_CM_ACTIVE || !(conn->link_policy & HCI_LP_SNIFF))
return;
if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
struct hci_cp_sniff_subrate cp;
cp.handle = cpu_to_le16(conn->handle);
cp.max_latency = cpu_to_le16(0);
cp.min_remote_timeout = cpu_to_le16(0);
cp.min_local_timeout = cpu_to_le16(0);
hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
}
if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
struct hci_cp_sniff_mode cp;
cp.handle = cpu_to_le16(conn->handle);
cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
cp.attempt = cpu_to_le16(4);
cp.timeout = cpu_to_le16(1);
hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
}
}
/* Drop all connection on the device */
void hci_conn_hash_flush(struct hci_dev *hdev)
{
struct hci_conn_hash *h = &hdev->conn_hash;
struct list_head *p;
BT_DBG("hdev %s", hdev->name);
p = h->list.next;
while (p != &h->list) {
struct hci_conn *c;
c = list_entry(p, struct hci_conn, list);
p = p->next;
c->state = BT_CLOSED;
hci_proto_disconn_cfm(c, 0x16);
hci_conn_del(c);
}
}
/* Check pending connect attempts */
void hci_conn_check_pending(struct hci_dev *hdev)
{
struct hci_conn *conn;
BT_DBG("hdev %s", hdev->name);
hci_dev_lock(hdev);
conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
if (conn)
hci_acl_connect(conn);
hci_dev_unlock(hdev);
}
int hci_get_conn_list(void __user *arg)
{
struct hci_conn_list_req req, *cl;
struct hci_conn_info *ci;
struct hci_dev *hdev;
struct list_head *p;
int n = 0, size, err;
if (copy_from_user(&req, arg, sizeof(req)))
return -EFAULT;
if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
return -EINVAL;
size = sizeof(req) + req.conn_num * sizeof(*ci);
if (!(cl = kmalloc(size, GFP_KERNEL)))
return -ENOMEM;
if (!(hdev = hci_dev_get(req.dev_id))) {
kfree(cl);
return -ENODEV;
}
ci = cl->conn_info;
hci_dev_lock_bh(hdev);
list_for_each(p, &hdev->conn_hash.list) {
register struct hci_conn *c;
c = list_entry(p, struct hci_conn, list);
bacpy(&(ci + n)->bdaddr, &c->dst);
(ci + n)->handle = c->handle;
(ci + n)->type = c->type;
(ci + n)->out = c->out;
(ci + n)->state = c->state;
(ci + n)->link_mode = c->link_mode;
if (++n >= req.conn_num)
break;
}
hci_dev_unlock_bh(hdev);
cl->dev_id = hdev->id;
cl->conn_num = n;
size = sizeof(req) + n * sizeof(*ci);
hci_dev_put(hdev);
err = copy_to_user(arg, cl, size);
kfree(cl);
return err ? -EFAULT : 0;
}
int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
{
struct hci_conn_info_req req;
struct hci_conn_info ci;
struct hci_conn *conn;
char __user *ptr = arg + sizeof(req);
if (copy_from_user(&req, arg, sizeof(req)))
return -EFAULT;
hci_dev_lock_bh(hdev);
conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
if (conn) {
bacpy(&ci.bdaddr, &conn->dst);
ci.handle = conn->handle;
ci.type = conn->type;
ci.out = conn->out;
ci.state = conn->state;
ci.link_mode = conn->link_mode;
}
hci_dev_unlock_bh(hdev);
if (!conn)
return -ENOENT;
return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
}
int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
{
struct hci_auth_info_req req;
struct hci_conn *conn;
if (copy_from_user(&req, arg, sizeof(req)))
return -EFAULT;
hci_dev_lock_bh(hdev);
conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
if (conn)
req.type = conn->auth_type;
hci_dev_unlock_bh(hdev);
if (!conn)
return -ENOENT;
return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
}