diff options
Diffstat (limited to 'net/bluetooth/hidp/core.c')
| -rw-r--r-- | net/bluetooth/hidp/core.c | 555 |
1 files changed, 551 insertions, 4 deletions
diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c index cef1021d5403..8d30a33b27d9 100644 --- a/net/bluetooth/hidp/core.c +++ b/net/bluetooth/hidp/core.c @@ -1,6 +1,7 @@ /* HIDP implementation for Linux Bluetooth stack (BlueZ). Copyright (C) 2003-2004 Marcel Holtmann <marcel@holtmann.org> + Copyright (C) 2013 David Herrmann <dh.herrmann@gmail.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 @@ -20,6 +21,7 @@ SOFTWARE IS DISCLAIMED. */ +#include <linux/kref.h> #include <linux/module.h> #include <linux/file.h> #include <linux/kthread.h> @@ -59,6 +61,13 @@ static unsigned char hidp_keycode[256] = { static unsigned char hidp_mkeyspat[] = { 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 }; +static int hidp_session_probe(struct l2cap_conn *conn, + struct l2cap_user *user); +static void hidp_session_remove(struct l2cap_conn *conn, + struct l2cap_user *user); +static int hidp_session_thread(void *arg); +static void hidp_session_terminate(struct hidp_session *s); + static inline void hidp_schedule(struct hidp_session *session) { struct sock *ctrl_sk = session->ctrl_sock->sk; @@ -838,7 +847,7 @@ static int hidp_setup_input(struct hidp_session *session, input->relbit[0] |= BIT_MASK(REL_WHEEL); } - input->dev.parent = &session->conn->dev; + input->dev.parent = &session->hconn->dev; input->event = hidp_input_event; @@ -942,7 +951,7 @@ static int hidp_setup_hid(struct hidp_session *session, snprintf(hid->uniq, sizeof(hid->uniq), "%pMR", &bt_sk(session->ctrl_sock->sk)->dst); - hid->dev.parent = &session->conn->dev; + hid->dev.parent = &session->hconn->dev; hid->ll_driver = &hidp_hid_driver; hid->hid_get_raw_report = hidp_get_raw_report; @@ -964,6 +973,543 @@ fault: return err; } +/* initialize session devices */ +static int hidp_session_dev_init(struct hidp_session *session, + struct hidp_connadd_req *req) +{ + int ret; + + if (req->rd_size > 0) { + ret = hidp_setup_hid(session, req); + if (ret && ret != -ENODEV) + return ret; + } + + if (!session->hid) { + ret = hidp_setup_input(session, req); + if (ret < 0) + return ret; + } + + return 0; +} + +/* destroy session devices */ +static void hidp_session_dev_destroy(struct hidp_session *session) +{ + if (session->hid) + put_device(&session->hid->dev); + else if (session->input) + input_put_device(session->input); + + kfree(session->rd_data); + session->rd_data = NULL; +} + +/* add HID/input devices to their underlying bus systems */ +static int hidp_session_dev_add(struct hidp_session *session) +{ + int ret; + + /* Both HID and input systems drop a ref-count when unregistering the + * device but they don't take a ref-count when registering them. Work + * around this by explicitly taking a refcount during registration + * which is dropped automatically by unregistering the devices. */ + + if (session->hid) { + ret = hid_add_device(session->hid); + if (ret) + return ret; + get_device(&session->hid->dev); + } else if (session->input) { + ret = input_register_device(session->input); + if (ret) + return ret; + input_get_device(session->input); + } + + return 0; +} + +/* remove HID/input devices from their bus systems */ +static void hidp_session_dev_del(struct hidp_session *session) +{ + if (session->hid) + hid_destroy_device(session->hid); + else if (session->input) + input_unregister_device(session->input); +} + +/* + * Create new session object + * Allocate session object, initialize static fields, copy input data into the + * object and take a reference to all sub-objects. + * This returns 0 on success and puts a pointer to the new session object in + * \out. Otherwise, an error code is returned. + * The new session object has an initial ref-count of 1. + */ +static int hidp_session_new(struct hidp_session **out, const bdaddr_t *bdaddr, + struct socket *ctrl_sock, + struct socket *intr_sock, + struct hidp_connadd_req *req, + struct l2cap_conn *conn) +{ + struct hidp_session *session; + int ret; + struct bt_sock *ctrl, *intr; + + ctrl = bt_sk(ctrl_sock->sk); + intr = bt_sk(intr_sock->sk); + + session = kzalloc(sizeof(*session), GFP_KERNEL); + if (!session) + return -ENOMEM; + + /* object and runtime management */ + kref_init(&session->ref); + atomic_set(&session->state, HIDP_SESSION_IDLING); + init_waitqueue_head(&session->state_queue); + session->flags = req->flags & (1 << HIDP_BLUETOOTH_VENDOR_ID); + + /* connection management */ + bacpy(&session->bdaddr, bdaddr); + session->conn = conn; + session->user.probe = hidp_session_probe; + session->user.remove = hidp_session_remove; + session->ctrl_sock = ctrl_sock; + session->intr_sock = intr_sock; + skb_queue_head_init(&session->ctrl_transmit); + skb_queue_head_init(&session->intr_transmit); + session->ctrl_mtu = min_t(uint, l2cap_pi(ctrl)->chan->omtu, + l2cap_pi(ctrl)->chan->imtu); + session->intr_mtu = min_t(uint, l2cap_pi(intr)->chan->omtu, + l2cap_pi(intr)->chan->imtu); + session->idle_to = req->idle_to; + + /* device management */ + setup_timer(&session->timer, hidp_idle_timeout, + (unsigned long)session); + + /* session data */ + mutex_init(&session->report_mutex); + init_waitqueue_head(&session->report_queue); + + ret = hidp_session_dev_init(session, req); + if (ret) + goto err_free; + + l2cap_conn_get(session->conn); + get_file(session->intr_sock->file); + get_file(session->ctrl_sock->file); + *out = session; + return 0; + +err_free: + kfree(session); + return ret; +} + +/* increase ref-count of the given session by one */ +static void hidp_session_get(struct hidp_session *session) +{ + kref_get(&session->ref); +} + +/* release callback */ +static void session_free(struct kref *ref) +{ + struct hidp_session *session = container_of(ref, struct hidp_session, + ref); + + hidp_session_dev_destroy(session); + skb_queue_purge(&session->ctrl_transmit); + skb_queue_purge(&session->intr_transmit); + fput(session->intr_sock->file); + fput(session->ctrl_sock->file); + l2cap_conn_put(session->conn); + kfree(session); +} + +/* decrease ref-count of the given session by one */ +static void hidp_session_put(struct hidp_session *session) +{ + kref_put(&session->ref, session_free); +} + +/* + * Search the list of active sessions for a session with target address + * \bdaddr. You must hold at least a read-lock on \hidp_session_sem. As long as + * you do not release this lock, the session objects cannot vanish and you can + * safely take a reference to the session yourself. + */ +static struct hidp_session *__hidp_session_find(const bdaddr_t *bdaddr) +{ + struct hidp_session *session; + + list_for_each_entry(session, &hidp_session_list, list) { + if (!bacmp(bdaddr, &session->bdaddr)) + return session; + } + + return NULL; +} + +/* + * Same as __hidp_session_find() but no locks must be held. This also takes a + * reference of the returned session (if non-NULL) so you must drop this + * reference if you no longer use the object. + */ +static struct hidp_session *hidp_session_find(const bdaddr_t *bdaddr) +{ + struct hidp_session *session; + + down_read(&hidp_session_sem); + + session = __hidp_session_find(bdaddr); + if (session) + hidp_session_get(session); + + up_read(&hidp_session_sem); + + return session; +} + +/* + * Start session synchronously + * This starts a session thread and waits until initialization + * is done or returns an error if it couldn't be started. + * If this returns 0 the session thread is up and running. You must call + * hipd_session_stop_sync() before deleting any runtime resources. + */ +static int hidp_session_start_sync(struct hidp_session *session) +{ + unsigned int vendor, product; + + if (session->hid) { + vendor = session->hid->vendor; + product = session->hid->product; + } else if (session->input) { + vendor = session->input->id.vendor; + product = session->input->id.product; + } else { + vendor = 0x0000; + product = 0x0000; + } + + session->task = kthread_run(hidp_session_thread, session, + "khidpd_%04x%04x", vendor, product); + if (IS_ERR(session->task)) + return PTR_ERR(session->task); + + while (atomic_read(&session->state) <= HIDP_SESSION_IDLING) + wait_event(session->state_queue, + atomic_read(&session->state) > HIDP_SESSION_IDLING); + + return 0; +} + +/* + * Terminate session thread + * Wake up session thread and notify it to stop. This is asynchronous and + * returns immediately. Call this whenever a runtime error occurs and you want + * the session to stop. + * Note: wake_up_process() performs any necessary memory-barriers for us. + */ +static void hidp_session_terminate(struct hidp_session *session) +{ + atomic_inc(&session->terminate); + wake_up_process(session->task); +} + +/* + * Probe HIDP session + * This is called from the l2cap_conn core when our l2cap_user object is bound + * to the hci-connection. We get the session via the \user object and can now + * start the session thread, register the HID/input devices and link it into + * the global session list. + * The global session-list owns its own reference to the session object so you + * can drop your own reference after registering the l2cap_user object. + */ +static int hidp_session_probe(struct l2cap_conn *conn, + struct l2cap_user *user) +{ + struct hidp_session *session = container_of(user, + struct hidp_session, + user); + struct hidp_session *s; + int ret; + + down_write(&hidp_session_sem); + + /* check that no other session for this device exists */ + s = __hidp_session_find(&session->bdaddr); + if (s) { + ret = -EEXIST; + goto out_unlock; + } + + ret = hidp_session_start_sync(session); + if (ret) + goto out_unlock; + + ret = hidp_session_dev_add(session); + if (ret) + goto out_stop; + + hidp_session_get(session); + list_add(&session->list, &hidp_session_list); + ret = 0; + goto out_unlock; + +out_stop: + hidp_session_terminate(session); +out_unlock: + up_write(&hidp_session_sem); + return ret; +} + +/* + * Remove HIDP session + * Called from the l2cap_conn core when either we explicitly unregistered + * the l2cap_user object or if the underlying connection is shut down. + * We signal the hidp-session thread to shut down, unregister the HID/input + * devices and unlink the session from the global list. + * This drops the reference to the session that is owned by the global + * session-list. + * Note: We _must_ not synchronosly wait for the session-thread to shut down. + * This is, because the session-thread might be waiting for an HCI lock that is + * held while we are called. Therefore, we only unregister the devices and + * notify the session-thread to terminate. The thread itself owns a reference + * to the session object so it can safely shut down. + */ +static void hidp_session_remove(struct l2cap_conn *conn, + struct l2cap_user *user) +{ + struct hidp_session *session = container_of(user, + struct hidp_session, + user); + + down_write(&hidp_session_sem); + + hidp_session_terminate(session); + hidp_session_dev_del(session); + list_del(&session->list); + + up_write(&hidp_session_sem); + + hidp_session_put(session); +} + +/* + * Session Worker + * This performs the actual main-loop of the HIDP worker. We first check + * whether the underlying connection is still alive, then parse all pending + * messages and finally send all outstanding messages. + */ +static void hidp_session_run(struct hidp_session *session) +{ + struct sock *ctrl_sk = session->ctrl_sock->sk; + struct sock *intr_sk = session->intr_sock->sk; + struct sk_buff *skb; + + for (;;) { + /* + * This thread can be woken up two ways: + * - You call hidp_session_terminate() which sets the + * session->terminate flag and wakes this thread up. + * - Via modifying the socket state of ctrl/intr_sock. This + * thread is woken up by ->sk_state_changed(). + * + * Note: set_current_state() performs any necessary + * memory-barriers for us. + */ + set_current_state(TASK_INTERRUPTIBLE); + + if (atomic_read(&session->terminate)) + break; + + if (ctrl_sk->sk_state != BT_CONNECTED || + intr_sk->sk_state != BT_CONNECTED) + break; + + /* parse incoming intr-skbs */ + while ((skb = skb_dequeue(&intr_sk->sk_receive_queue))) { + skb_orphan(skb); + if (!skb_linearize(skb)) + hidp_recv_intr_frame(session, skb); + else + kfree_skb(skb); + } + + /* send pending intr-skbs */ + hidp_process_intr_transmit(session); + + /* parse incoming ctrl-skbs */ + while ((skb = skb_dequeue(&ctrl_sk->sk_receive_queue))) { + skb_orphan(skb); + if (!skb_linearize(skb)) + hidp_recv_ctrl_frame(session, skb); + else + kfree_skb(skb); + } + + /* send pending ctrl-skbs */ + hidp_process_ctrl_transmit(session); + + schedule(); + } + + atomic_inc(&session->terminate); + set_current_state(TASK_RUNNING); +} + +/* + * HIDP session thread + * This thread runs the I/O for a single HIDP session. Startup is synchronous + * which allows us to take references to ourself here instead of doing that in + * the caller. + * When we are ready to run we notify the caller and call hidp_session_run(). + */ +static int hidp_session_thread(void *arg) +{ + struct hidp_session *session = arg; + wait_queue_t ctrl_wait, intr_wait; + + BT_DBG("session %p", session); + + /* initialize runtime environment */ + hidp_session_get(session); + __module_get(THIS_MODULE); + set_user_nice(current, -15); + hidp_set_timer(session); + + init_waitqueue_entry(&ctrl_wait, current); + init_waitqueue_entry(&intr_wait, current); + add_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait); + add_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait); + /* This memory barrier is paired with wq_has_sleeper(). See + * sock_poll_wait() for more information why this is needed. */ + smp_mb(); + + /* notify synchronous startup that we're ready */ + atomic_inc(&session->state); + wake_up(&session->state_queue); + + /* run session */ + hidp_session_run(session); + + /* cleanup runtime environment */ + remove_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait); + remove_wait_queue(sk_sleep(session->intr_sock->sk), &ctrl_wait); + wake_up_interruptible(&session->report_queue); + hidp_del_timer(session); + + /* + * If we stopped ourself due to any internal signal, we should try to + * unregister our own session here to avoid having it linger until the + * parent l2cap_conn dies or user-space cleans it up. + * This does not deadlock as we don't do any synchronous shutdown. + * Instead, this call has the same semantics as if user-space tried to + * delete the session. + */ + l2cap_unregister_user(session->conn, &session->user); + hidp_session_put(session); + + module_put_and_exit(0); + return 0; +} + +static int hidp_verify_sockets(struct socket *ctrl_sock, + struct socket *intr_sock) +{ + struct bt_sock *ctrl, *intr; + struct hidp_session *session; + + if (!l2cap_is_socket(ctrl_sock) || !l2cap_is_socket(intr_sock)) + return -EINVAL; + + ctrl = bt_sk(ctrl_sock->sk); + intr = bt_sk(intr_sock->sk); + + if (bacmp(&ctrl->src, &intr->src) || bacmp(&ctrl->dst, &intr->dst)) + return -ENOTUNIQ; + if (ctrl->sk.sk_state != BT_CONNECTED || + intr->sk.sk_state != BT_CONNECTED) + return -EBADFD; + + /* early session check, we check again during session registration */ + session = hidp_session_find(&ctrl->dst); + if (session) { + hidp_session_put(session); + return -EEXIST; + } + + return 0; +} + +int hidp_connection_add(struct hidp_connadd_req *req, + struct socket *ctrl_sock, + struct socket *intr_sock) +{ + struct hidp_session *session; + struct l2cap_conn *conn; + struct l2cap_chan *chan = l2cap_pi(ctrl_sock->sk)->chan; + int ret; + + ret = hidp_verify_sockets(ctrl_sock, intr_sock); + if (ret) + return ret; + + conn = NULL; + l2cap_chan_lock(chan); + if (chan->conn) { + l2cap_conn_get(chan->conn); + conn = chan->conn; + } + l2cap_chan_unlock(chan); + + if (!conn) + return -EBADFD; + + ret = hidp_session_new(&session, &bt_sk(ctrl_sock->sk)->dst, ctrl_sock, + intr_sock, req, conn); + if (ret) + goto out_conn; + + ret = l2cap_register_user(conn, &session->user); + if (ret) + goto out_session; + + ret = 0; + +out_session: + hidp_session_put(session); +out_conn: + l2cap_conn_put(conn); + return ret; +} + +int hidp_connection_del(struct hidp_conndel_req *req) +{ + struct hidp_session *session; + + session = hidp_session_find(&req->bdaddr); + if (!session) + return -ENOENT; + + if (req->flags & (1 << HIDP_VIRTUAL_CABLE_UNPLUG)) + hidp_send_ctrl_message(session, + HIDP_TRANS_HID_CONTROL | + HIDP_CTRL_VIRTUAL_CABLE_UNPLUG, + NULL, 0); + else + l2cap_unregister_user(session->conn, &session->user); + + hidp_session_put(session); + + return 0; +} + int hidp_add_connection(struct hidp_connadd_req *req, struct socket *ctrl_sock, struct socket *intr_sock) { struct hidp_session *session, *s; @@ -1006,8 +1552,8 @@ int hidp_add_connection(struct hidp_connadd_req *req, struct socket *ctrl_sock, session->ctrl_sock = ctrl_sock; session->intr_sock = intr_sock; - session->conn = hidp_get_connection(session); - if (!session->conn) { + session->hconn = hidp_get_connection(session); + if (!session->hconn) { err = -ENOTCONN; goto failed; } @@ -1208,6 +1754,7 @@ module_init(hidp_init); module_exit(hidp_exit); MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); +MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>"); MODULE_DESCRIPTION("Bluetooth HIDP ver " VERSION); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); |