/*
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
SOFTWARE IS DISCLAIMED.
*/
+#include <linux/kref.h>
#include <linux/module.h>
#include <linux/file.h>
#include <linux/kthread.h>
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;
input->relbit[0] |= BIT_MASK(REL_WHEEL);
}
- input->dev.parent = &session->conn->dev;
+ input->dev.parent = &session->hconn->dev;
input->event = hidp_input_event;
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;
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;
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;
}
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");
projects / linux-beck.git / commitdiff