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linux/net/bluetooth/hci_conn.c
Marcel Holtmann 9eba32b86d Bluetooth: Add extra device reference counting for connections 
The device model itself has no real usable reference counting at the
moment and this causes problems if parents are deleted before their
children. The device model itself handles the memory details of this
correctly, but the uevent order is not consistent. This causes various
problems for systems like HAL or even X.

So until device_put() does a proper cleanup, the device for Bluetooth
connection will be protected with an extra reference counting to ensure
the correct order of uevents when connections are terminated.

This is not an automatic feature. Higher Bluetooth layers like HIDP or
BNEP should grab this new reference to ensure that their uevents are
send before the ones from the parent device.

Based on a report by Brian Rogers <brian@xyzw.org>

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2009-08-22 14:19:26 -07:00

702 lines
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/*
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 && conn->out)
hci_acl_connect_cancel(conn);
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);
atomic_set(&conn->devref, 0);
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_put_device(conn);
hci_dev_put(hdev);
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);
}
void hci_conn_hold_device(struct hci_conn *conn)
{
atomic_inc(&conn->devref);
}
EXPORT_SYMBOL(hci_conn_hold_device);
void hci_conn_put_device(struct hci_conn *conn)
{
if (atomic_dec_and_test(&conn->devref))
hci_conn_del_sysfs(conn);
}
EXPORT_SYMBOL(hci_conn_put_device);
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;
}
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