2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
5 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License version 2 as
9 published by the Free Software Foundation;
11 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
12 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
14 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
15 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
16 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
21 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
22 SOFTWARE IS DISCLAIMED.
25 /* Bluetooth SCO sockets. */
27 #include <linux/module.h>
29 #include <linux/types.h>
30 #include <linux/errno.h>
31 #include <linux/kernel.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/poll.h>
35 #include <linux/fcntl.h>
36 #include <linux/init.h>
37 #include <linux/interrupt.h>
38 #include <linux/socket.h>
39 #include <linux/skbuff.h>
40 #include <linux/device.h>
41 #include <linux/debugfs.h>
42 #include <linux/seq_file.h>
43 #include <linux/list.h>
44 #include <linux/security.h>
47 #include <asm/system.h>
48 #include <linux/uaccess.h>
50 #include <net/bluetooth/bluetooth.h>
51 #include <net/bluetooth/hci_core.h>
52 #include <net/bluetooth/sco.h>
54 static int disable_esco;
56 static const struct proto_ops sco_sock_ops;
58 static struct bt_sock_list sco_sk_list = {
59 .lock = __RW_LOCK_UNLOCKED(sco_sk_list.lock)
62 static void __sco_chan_add(struct sco_conn *conn, struct sock *sk, struct sock *parent);
63 static void sco_chan_del(struct sock *sk, int err);
65 static int sco_conn_del(struct hci_conn *conn, int err);
67 static void sco_sock_close(struct sock *sk);
68 static void sco_sock_kill(struct sock *sk);
70 /* ---- SCO timers ---- */
71 static void sco_sock_timeout(unsigned long arg)
73 struct sock *sk = (struct sock *) arg;
75 BT_DBG("sock %p state %d", sk, sk->sk_state);
78 sk->sk_err = ETIMEDOUT;
79 sk->sk_state_change(sk);
86 static void sco_sock_set_timer(struct sock *sk, long timeout)
88 BT_DBG("sock %p state %d timeout %ld", sk, sk->sk_state, timeout);
89 sk_reset_timer(sk, &sk->sk_timer, jiffies + timeout);
92 static void sco_sock_clear_timer(struct sock *sk)
94 BT_DBG("sock %p state %d", sk, sk->sk_state);
95 sk_stop_timer(sk, &sk->sk_timer);
98 /* ---- SCO connections ---- */
99 static struct sco_conn *sco_conn_add(struct hci_conn *hcon, __u8 status)
101 struct hci_dev *hdev = hcon->hdev;
102 struct sco_conn *conn = hcon->sco_data;
107 conn = kzalloc(sizeof(struct sco_conn), GFP_ATOMIC);
111 spin_lock_init(&conn->lock);
113 hcon->sco_data = conn;
116 conn->src = &hdev->bdaddr;
117 conn->dst = &hcon->dst;
119 if (hdev->sco_mtu > 0)
120 conn->mtu = hdev->sco_mtu;
124 BT_DBG("hcon %p conn %p", hcon, conn);
129 static inline struct sock *sco_chan_get(struct sco_conn *conn)
131 struct sock *sk = NULL;
134 sco_conn_unlock(conn);
138 static int sco_conn_del(struct hci_conn *hcon, int err)
140 struct sco_conn *conn = hcon->sco_data;
146 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
149 sk = sco_chan_get(conn);
152 sco_sock_clear_timer(sk);
153 sco_chan_del(sk, err);
158 hcon->sco_data = NULL;
163 static inline int sco_chan_add(struct sco_conn *conn, struct sock *sk, struct sock *parent)
171 __sco_chan_add(conn, sk, parent);
173 sco_conn_unlock(conn);
177 static int sco_connect(struct sock *sk)
179 bdaddr_t *src = &bt_sk(sk)->src;
180 bdaddr_t *dst = &bt_sk(sk)->dst;
181 struct sco_conn *conn;
182 struct hci_conn *hcon;
183 struct hci_dev *hdev;
186 BT_DBG("%s -> %s", batostr(src), batostr(dst));
188 hdev = hci_get_route(dst, src);
190 return -EHOSTUNREACH;
192 hci_dev_lock_bh(hdev);
194 if (lmp_esco_capable(hdev) && !disable_esco)
199 hcon = hci_connect(hdev, type, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
205 conn = sco_conn_add(hcon, 0);
212 /* Update source addr of the socket */
213 bacpy(src, conn->src);
215 err = sco_chan_add(conn, sk, NULL);
219 if (hcon->state == BT_CONNECTED) {
220 sco_sock_clear_timer(sk);
221 sk->sk_state = BT_CONNECTED;
223 sk->sk_state = BT_CONNECT;
224 sco_sock_set_timer(sk, sk->sk_sndtimeo);
228 hci_dev_unlock_bh(hdev);
233 static inline int sco_send_frame(struct sock *sk, struct msghdr *msg, int len)
235 struct sco_conn *conn = sco_pi(sk)->conn;
239 /* Check outgoing MTU */
243 BT_DBG("sk %p len %d", sk, len);
245 count = min_t(unsigned int, conn->mtu, len);
246 skb = bt_skb_send_alloc(sk, count,
247 msg->msg_flags & MSG_DONTWAIT, &err);
251 if (memcpy_fromiovec(skb_put(skb, count), msg->msg_iov, count)) {
256 hci_send_sco(conn->hcon, skb);
261 static inline void sco_recv_frame(struct sco_conn *conn, struct sk_buff *skb)
263 struct sock *sk = sco_chan_get(conn);
268 BT_DBG("sk %p len %d", sk, skb->len);
270 if (sk->sk_state != BT_CONNECTED)
273 if (!sock_queue_rcv_skb(sk, skb))
280 /* -------- Socket interface ---------- */
281 static struct sock *__sco_get_sock_by_addr(bdaddr_t *ba)
284 struct hlist_node *node;
286 sk_for_each(sk, node, &sco_sk_list.head)
287 if (!bacmp(&bt_sk(sk)->src, ba))
294 /* Find socket listening on source bdaddr.
295 * Returns closest match.
297 static struct sock *sco_get_sock_listen(bdaddr_t *src)
299 struct sock *sk = NULL, *sk1 = NULL;
300 struct hlist_node *node;
302 read_lock(&sco_sk_list.lock);
304 sk_for_each(sk, node, &sco_sk_list.head) {
305 if (sk->sk_state != BT_LISTEN)
309 if (!bacmp(&bt_sk(sk)->src, src))
313 if (!bacmp(&bt_sk(sk)->src, BDADDR_ANY))
317 read_unlock(&sco_sk_list.lock);
319 return node ? sk : sk1;
322 static void sco_sock_destruct(struct sock *sk)
326 skb_queue_purge(&sk->sk_receive_queue);
327 skb_queue_purge(&sk->sk_write_queue);
330 static void sco_sock_cleanup_listen(struct sock *parent)
334 BT_DBG("parent %p", parent);
336 /* Close not yet accepted channels */
337 while ((sk = bt_accept_dequeue(parent, NULL))) {
342 parent->sk_state = BT_CLOSED;
343 sock_set_flag(parent, SOCK_ZAPPED);
346 /* Kill socket (only if zapped and orphan)
347 * Must be called on unlocked socket.
349 static void sco_sock_kill(struct sock *sk)
351 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
354 BT_DBG("sk %p state %d", sk, sk->sk_state);
356 /* Kill poor orphan */
357 bt_sock_unlink(&sco_sk_list, sk);
358 sock_set_flag(sk, SOCK_DEAD);
362 static void __sco_sock_close(struct sock *sk)
364 BT_DBG("sk %p state %d socket %p", sk, sk->sk_state, sk->sk_socket);
366 switch (sk->sk_state) {
368 sco_sock_cleanup_listen(sk);
373 if (sco_pi(sk)->conn) {
374 sk->sk_state = BT_DISCONN;
375 sco_sock_set_timer(sk, SCO_DISCONN_TIMEOUT);
376 hci_conn_put(sco_pi(sk)->conn->hcon);
377 sco_pi(sk)->conn->hcon = NULL;
379 sco_chan_del(sk, ECONNRESET);
384 sco_chan_del(sk, ECONNRESET);
388 sock_set_flag(sk, SOCK_ZAPPED);
393 /* Must be called on unlocked socket. */
394 static void sco_sock_close(struct sock *sk)
396 sco_sock_clear_timer(sk);
398 __sco_sock_close(sk);
403 static void sco_sock_init(struct sock *sk, struct sock *parent)
408 sk->sk_type = parent->sk_type;
409 security_sk_clone(parent, sk);
413 static struct proto sco_proto = {
415 .owner = THIS_MODULE,
416 .obj_size = sizeof(struct sco_pinfo)
419 static struct sock *sco_sock_alloc(struct net *net, struct socket *sock, int proto, gfp_t prio)
423 sk = sk_alloc(net, PF_BLUETOOTH, prio, &sco_proto);
427 sock_init_data(sock, sk);
428 INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
430 sk->sk_destruct = sco_sock_destruct;
431 sk->sk_sndtimeo = SCO_CONN_TIMEOUT;
433 sock_reset_flag(sk, SOCK_ZAPPED);
435 sk->sk_protocol = proto;
436 sk->sk_state = BT_OPEN;
438 setup_timer(&sk->sk_timer, sco_sock_timeout, (unsigned long)sk);
440 bt_sock_link(&sco_sk_list, sk);
444 static int sco_sock_create(struct net *net, struct socket *sock, int protocol,
449 BT_DBG("sock %p", sock);
451 sock->state = SS_UNCONNECTED;
453 if (sock->type != SOCK_SEQPACKET)
454 return -ESOCKTNOSUPPORT;
456 sock->ops = &sco_sock_ops;
458 sk = sco_sock_alloc(net, sock, protocol, GFP_ATOMIC);
462 sco_sock_init(sk, NULL);
466 static int sco_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
468 struct sockaddr_sco *sa = (struct sockaddr_sco *) addr;
469 struct sock *sk = sock->sk;
470 bdaddr_t *src = &sa->sco_bdaddr;
473 BT_DBG("sk %p %s", sk, batostr(&sa->sco_bdaddr));
475 if (!addr || addr->sa_family != AF_BLUETOOTH)
480 if (sk->sk_state != BT_OPEN) {
485 write_lock_bh(&sco_sk_list.lock);
487 if (bacmp(src, BDADDR_ANY) && __sco_get_sock_by_addr(src)) {
490 /* Save source address */
491 bacpy(&bt_sk(sk)->src, &sa->sco_bdaddr);
492 sk->sk_state = BT_BOUND;
495 write_unlock_bh(&sco_sk_list.lock);
502 static int sco_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags)
504 struct sockaddr_sco *sa = (struct sockaddr_sco *) addr;
505 struct sock *sk = sock->sk;
511 if (alen < sizeof(struct sockaddr_sco) ||
512 addr->sa_family != AF_BLUETOOTH)
515 if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND)
518 if (sk->sk_type != SOCK_SEQPACKET)
523 /* Set destination address and psm */
524 bacpy(&bt_sk(sk)->dst, &sa->sco_bdaddr);
526 err = sco_connect(sk);
530 err = bt_sock_wait_state(sk, BT_CONNECTED,
531 sock_sndtimeo(sk, flags & O_NONBLOCK));
538 static int sco_sock_listen(struct socket *sock, int backlog)
540 struct sock *sk = sock->sk;
543 BT_DBG("sk %p backlog %d", sk, backlog);
547 if (sk->sk_state != BT_BOUND || sock->type != SOCK_SEQPACKET) {
552 sk->sk_max_ack_backlog = backlog;
553 sk->sk_ack_backlog = 0;
554 sk->sk_state = BT_LISTEN;
561 static int sco_sock_accept(struct socket *sock, struct socket *newsock, int flags)
563 DECLARE_WAITQUEUE(wait, current);
564 struct sock *sk = sock->sk, *ch;
570 timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
572 BT_DBG("sk %p timeo %ld", sk, timeo);
574 /* Wait for an incoming connection. (wake-one). */
575 add_wait_queue_exclusive(sk_sleep(sk), &wait);
577 set_current_state(TASK_INTERRUPTIBLE);
579 if (sk->sk_state != BT_LISTEN) {
584 ch = bt_accept_dequeue(sk, newsock);
593 if (signal_pending(current)) {
594 err = sock_intr_errno(timeo);
599 timeo = schedule_timeout(timeo);
602 __set_current_state(TASK_RUNNING);
603 remove_wait_queue(sk_sleep(sk), &wait);
608 newsock->state = SS_CONNECTED;
610 BT_DBG("new socket %p", ch);
617 static int sco_sock_getname(struct socket *sock, struct sockaddr *addr, int *len, int peer)
619 struct sockaddr_sco *sa = (struct sockaddr_sco *) addr;
620 struct sock *sk = sock->sk;
622 BT_DBG("sock %p, sk %p", sock, sk);
624 addr->sa_family = AF_BLUETOOTH;
625 *len = sizeof(struct sockaddr_sco);
628 bacpy(&sa->sco_bdaddr, &bt_sk(sk)->dst);
630 bacpy(&sa->sco_bdaddr, &bt_sk(sk)->src);
635 static int sco_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
636 struct msghdr *msg, size_t len)
638 struct sock *sk = sock->sk;
641 BT_DBG("sock %p, sk %p", sock, sk);
643 err = sock_error(sk);
647 if (msg->msg_flags & MSG_OOB)
652 if (sk->sk_state == BT_CONNECTED)
653 err = sco_send_frame(sk, msg, len);
661 static int sco_sock_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
663 struct sock *sk = sock->sk;
680 static int sco_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
682 struct sock *sk = sock->sk;
683 struct sco_options opts;
684 struct sco_conninfo cinfo;
689 if (get_user(len, optlen))
696 if (sk->sk_state != BT_CONNECTED) {
701 opts.mtu = sco_pi(sk)->conn->mtu;
703 BT_DBG("mtu %d", opts.mtu);
705 len = min_t(unsigned int, len, sizeof(opts));
706 if (copy_to_user(optval, (char *)&opts, len))
712 if (sk->sk_state != BT_CONNECTED) {
717 memset(&cinfo, 0, sizeof(cinfo));
718 cinfo.hci_handle = sco_pi(sk)->conn->hcon->handle;
719 memcpy(cinfo.dev_class, sco_pi(sk)->conn->hcon->dev_class, 3);
721 len = min_t(unsigned int, len, sizeof(cinfo));
722 if (copy_to_user(optval, (char *)&cinfo, len))
736 static int sco_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
738 struct sock *sk = sock->sk;
743 if (level == SOL_SCO)
744 return sco_sock_getsockopt_old(sock, optname, optval, optlen);
746 if (get_user(len, optlen))
761 static int sco_sock_shutdown(struct socket *sock, int how)
763 struct sock *sk = sock->sk;
766 BT_DBG("sock %p, sk %p", sock, sk);
772 if (!sk->sk_shutdown) {
773 sk->sk_shutdown = SHUTDOWN_MASK;
774 sco_sock_clear_timer(sk);
775 __sco_sock_close(sk);
777 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
778 !(current->flags & PF_EXITING))
779 err = bt_sock_wait_state(sk, BT_CLOSED,
786 static int sco_sock_release(struct socket *sock)
788 struct sock *sk = sock->sk;
791 BT_DBG("sock %p, sk %p", sock, sk);
798 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
799 !(current->flags & PF_EXITING)) {
801 err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
810 static void __sco_chan_add(struct sco_conn *conn, struct sock *sk, struct sock *parent)
812 BT_DBG("conn %p", conn);
814 sco_pi(sk)->conn = conn;
818 bt_accept_enqueue(parent, sk);
822 * Must be called on the locked socket. */
823 static void sco_chan_del(struct sock *sk, int err)
825 struct sco_conn *conn;
827 conn = sco_pi(sk)->conn;
829 BT_DBG("sk %p, conn %p, err %d", sk, conn, err);
834 sco_pi(sk)->conn = NULL;
835 sco_conn_unlock(conn);
838 hci_conn_put(conn->hcon);
841 sk->sk_state = BT_CLOSED;
843 sk->sk_state_change(sk);
845 sock_set_flag(sk, SOCK_ZAPPED);
848 static void sco_conn_ready(struct sco_conn *conn)
851 struct sock *sk = conn->sk;
853 BT_DBG("conn %p", conn);
858 sco_sock_clear_timer(sk);
860 sk->sk_state = BT_CONNECTED;
861 sk->sk_state_change(sk);
864 parent = sco_get_sock_listen(conn->src);
868 bh_lock_sock(parent);
870 sk = sco_sock_alloc(sock_net(parent), NULL,
871 BTPROTO_SCO, GFP_ATOMIC);
873 bh_unlock_sock(parent);
877 sco_sock_init(sk, parent);
879 bacpy(&bt_sk(sk)->src, conn->src);
880 bacpy(&bt_sk(sk)->dst, conn->dst);
882 hci_conn_hold(conn->hcon);
883 __sco_chan_add(conn, sk, parent);
885 sk->sk_state = BT_CONNECTED;
888 parent->sk_data_ready(parent, 1);
890 bh_unlock_sock(parent);
894 sco_conn_unlock(conn);
897 /* ----- SCO interface with lower layer (HCI) ----- */
898 static int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 type)
900 register struct sock *sk;
901 struct hlist_node *node;
904 if (type != SCO_LINK && type != ESCO_LINK)
907 BT_DBG("hdev %s, bdaddr %s", hdev->name, batostr(bdaddr));
909 /* Find listening sockets */
910 read_lock(&sco_sk_list.lock);
911 sk_for_each(sk, node, &sco_sk_list.head) {
912 if (sk->sk_state != BT_LISTEN)
915 if (!bacmp(&bt_sk(sk)->src, &hdev->bdaddr) ||
916 !bacmp(&bt_sk(sk)->src, BDADDR_ANY)) {
921 read_unlock(&sco_sk_list.lock);
926 static int sco_connect_cfm(struct hci_conn *hcon, __u8 status)
928 BT_DBG("hcon %p bdaddr %s status %d", hcon, batostr(&hcon->dst), status);
930 if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
934 struct sco_conn *conn;
936 conn = sco_conn_add(hcon, status);
938 sco_conn_ready(conn);
940 sco_conn_del(hcon, bt_to_errno(status));
945 static int sco_disconn_cfm(struct hci_conn *hcon, __u8 reason)
947 BT_DBG("hcon %p reason %d", hcon, reason);
949 if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
952 sco_conn_del(hcon, bt_to_errno(reason));
957 static int sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb)
959 struct sco_conn *conn = hcon->sco_data;
964 BT_DBG("conn %p len %d", conn, skb->len);
967 sco_recv_frame(conn, skb);
976 static int sco_debugfs_show(struct seq_file *f, void *p)
979 struct hlist_node *node;
981 read_lock_bh(&sco_sk_list.lock);
983 sk_for_each(sk, node, &sco_sk_list.head) {
984 seq_printf(f, "%s %s %d\n", batostr(&bt_sk(sk)->src),
985 batostr(&bt_sk(sk)->dst), sk->sk_state);
988 read_unlock_bh(&sco_sk_list.lock);
993 static int sco_debugfs_open(struct inode *inode, struct file *file)
995 return single_open(file, sco_debugfs_show, inode->i_private);
998 static const struct file_operations sco_debugfs_fops = {
999 .open = sco_debugfs_open,
1001 .llseek = seq_lseek,
1002 .release = single_release,
1005 static struct dentry *sco_debugfs;
1007 static const struct proto_ops sco_sock_ops = {
1008 .family = PF_BLUETOOTH,
1009 .owner = THIS_MODULE,
1010 .release = sco_sock_release,
1011 .bind = sco_sock_bind,
1012 .connect = sco_sock_connect,
1013 .listen = sco_sock_listen,
1014 .accept = sco_sock_accept,
1015 .getname = sco_sock_getname,
1016 .sendmsg = sco_sock_sendmsg,
1017 .recvmsg = bt_sock_recvmsg,
1018 .poll = bt_sock_poll,
1019 .ioctl = bt_sock_ioctl,
1020 .mmap = sock_no_mmap,
1021 .socketpair = sock_no_socketpair,
1022 .shutdown = sco_sock_shutdown,
1023 .setsockopt = sco_sock_setsockopt,
1024 .getsockopt = sco_sock_getsockopt
1027 static const struct net_proto_family sco_sock_family_ops = {
1028 .family = PF_BLUETOOTH,
1029 .owner = THIS_MODULE,
1030 .create = sco_sock_create,
1033 static struct hci_proto sco_hci_proto = {
1035 .id = HCI_PROTO_SCO,
1036 .connect_ind = sco_connect_ind,
1037 .connect_cfm = sco_connect_cfm,
1038 .disconn_cfm = sco_disconn_cfm,
1039 .recv_scodata = sco_recv_scodata
1042 int __init sco_init(void)
1046 err = proto_register(&sco_proto, 0);
1050 err = bt_sock_register(BTPROTO_SCO, &sco_sock_family_ops);
1052 BT_ERR("SCO socket registration failed");
1056 err = hci_register_proto(&sco_hci_proto);
1058 BT_ERR("SCO protocol registration failed");
1059 bt_sock_unregister(BTPROTO_SCO);
1064 sco_debugfs = debugfs_create_file("sco", 0444,
1065 bt_debugfs, NULL, &sco_debugfs_fops);
1067 BT_ERR("Failed to create SCO debug file");
1070 BT_INFO("SCO socket layer initialized");
1075 proto_unregister(&sco_proto);
1079 void __exit sco_exit(void)
1081 debugfs_remove(sco_debugfs);
1083 if (bt_sock_unregister(BTPROTO_SCO) < 0)
1084 BT_ERR("SCO socket unregistration failed");
1086 if (hci_unregister_proto(&sco_hci_proto) < 0)
1087 BT_ERR("SCO protocol unregistration failed");
1089 proto_unregister(&sco_proto);
1092 module_param(disable_esco, bool, 0644);
1093 MODULE_PARM_DESC(disable_esco, "Disable eSCO connection creation");