2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland
4 * License terms: GNU General Public License (GPL) version 2
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/spinlock.h>
14 #include <linux/mutex.h>
15 #include <linux/list.h>
16 #include <linux/wait.h>
17 #include <linux/poll.h>
18 #include <linux/tcp.h>
19 #include <linux/uaccess.h>
20 #include <linux/debugfs.h>
21 #include <linux/caif/caif_socket.h>
22 #include <linux/pkt_sched.h>
24 #include <net/tcp_states.h>
25 #include <net/caif/caif_layer.h>
26 #include <net/caif/caif_dev.h>
27 #include <net/caif/cfpkt.h>
29 MODULE_LICENSE("GPL");
30 MODULE_ALIAS_NETPROTO(AF_CAIF);
33 * CAIF state is re-using the TCP socket states.
34 * caif_states stored in sk_state reflect the state as reported by
35 * the CAIF stack, while sk_socket->state is the state of the socket.
38 CAIF_CONNECTED = TCP_ESTABLISHED,
39 CAIF_CONNECTING = TCP_SYN_SENT,
40 CAIF_DISCONNECTED = TCP_CLOSE
43 #define TX_FLOW_ON_BIT 1
44 #define RX_FLOW_ON_BIT 2
47 struct sock sk; /* must be first member */
50 struct caif_connect_request conn_req;
51 struct mutex readlock;
52 struct dentry *debugfs_socket_dir;
53 int headroom, tailroom, maxframe;
56 static int rx_flow_is_on(struct caifsock *cf_sk)
58 return test_bit(RX_FLOW_ON_BIT,
59 (void *) &cf_sk->flow_state);
62 static int tx_flow_is_on(struct caifsock *cf_sk)
64 return test_bit(TX_FLOW_ON_BIT,
65 (void *) &cf_sk->flow_state);
68 static void set_rx_flow_off(struct caifsock *cf_sk)
70 clear_bit(RX_FLOW_ON_BIT,
71 (void *) &cf_sk->flow_state);
74 static void set_rx_flow_on(struct caifsock *cf_sk)
76 set_bit(RX_FLOW_ON_BIT,
77 (void *) &cf_sk->flow_state);
80 static void set_tx_flow_off(struct caifsock *cf_sk)
82 clear_bit(TX_FLOW_ON_BIT,
83 (void *) &cf_sk->flow_state);
86 static void set_tx_flow_on(struct caifsock *cf_sk)
88 set_bit(TX_FLOW_ON_BIT,
89 (void *) &cf_sk->flow_state);
92 static void caif_read_lock(struct sock *sk)
94 struct caifsock *cf_sk;
95 cf_sk = container_of(sk, struct caifsock, sk);
96 mutex_lock(&cf_sk->readlock);
99 static void caif_read_unlock(struct sock *sk)
101 struct caifsock *cf_sk;
102 cf_sk = container_of(sk, struct caifsock, sk);
103 mutex_unlock(&cf_sk->readlock);
106 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
108 /* A quarter of full buffer is used a low water mark */
109 return cf_sk->sk.sk_rcvbuf / 4;
112 static void caif_flow_ctrl(struct sock *sk, int mode)
114 struct caifsock *cf_sk;
115 cf_sk = container_of(sk, struct caifsock, sk);
116 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
117 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
121 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
122 * not dropped, but CAIF is sending flow off instead.
124 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
128 struct sk_buff_head *list = &sk->sk_receive_queue;
129 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
131 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
132 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
133 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
134 atomic_read(&cf_sk->sk.sk_rmem_alloc),
135 sk_rcvbuf_lowwater(cf_sk));
136 set_rx_flow_off(cf_sk);
137 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
140 err = sk_filter(sk, skb);
143 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
144 set_rx_flow_off(cf_sk);
145 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
146 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
149 skb_set_owner_r(skb, sk);
150 /* Cache the SKB length before we tack it onto the receive
151 * queue. Once it is added it no longer belongs to us and
152 * may be freed by other threads of control pulling packets
155 spin_lock_irqsave(&list->lock, flags);
156 if (!sock_flag(sk, SOCK_DEAD))
157 __skb_queue_tail(list, skb);
158 spin_unlock_irqrestore(&list->lock, flags);
160 if (!sock_flag(sk, SOCK_DEAD))
161 sk->sk_data_ready(sk);
167 /* Packet Receive Callback function called from CAIF Stack */
168 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
170 struct caifsock *cf_sk;
173 cf_sk = container_of(layr, struct caifsock, layer);
174 skb = cfpkt_tonative(pkt);
176 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
180 caif_queue_rcv_skb(&cf_sk->sk, skb);
184 static void cfsk_hold(struct cflayer *layr)
186 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
187 sock_hold(&cf_sk->sk);
190 static void cfsk_put(struct cflayer *layr)
192 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
193 sock_put(&cf_sk->sk);
196 /* Packet Control Callback function called from CAIF */
197 static void caif_ctrl_cb(struct cflayer *layr,
198 enum caif_ctrlcmd flow,
201 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
203 case CAIF_CTRLCMD_FLOW_ON_IND:
204 /* OK from modem to start sending again */
205 set_tx_flow_on(cf_sk);
206 cf_sk->sk.sk_state_change(&cf_sk->sk);
209 case CAIF_CTRLCMD_FLOW_OFF_IND:
210 /* Modem asks us to shut up */
211 set_tx_flow_off(cf_sk);
212 cf_sk->sk.sk_state_change(&cf_sk->sk);
215 case CAIF_CTRLCMD_INIT_RSP:
216 /* We're now connected */
217 caif_client_register_refcnt(&cf_sk->layer,
218 cfsk_hold, cfsk_put);
219 cf_sk->sk.sk_state = CAIF_CONNECTED;
220 set_tx_flow_on(cf_sk);
221 cf_sk->sk.sk_shutdown = 0;
222 cf_sk->sk.sk_state_change(&cf_sk->sk);
225 case CAIF_CTRLCMD_DEINIT_RSP:
226 /* We're now disconnected */
227 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
228 cf_sk->sk.sk_state_change(&cf_sk->sk);
231 case CAIF_CTRLCMD_INIT_FAIL_RSP:
232 /* Connect request failed */
233 cf_sk->sk.sk_err = ECONNREFUSED;
234 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
235 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
237 * Socket "standards" seems to require POLLOUT to
238 * be set at connect failure.
240 set_tx_flow_on(cf_sk);
241 cf_sk->sk.sk_state_change(&cf_sk->sk);
244 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
245 /* Modem has closed this connection, or device is down. */
246 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
247 cf_sk->sk.sk_err = ECONNRESET;
248 set_rx_flow_on(cf_sk);
249 cf_sk->sk.sk_error_report(&cf_sk->sk);
253 pr_debug("Unexpected flow command %d\n", flow);
257 static void caif_check_flow_release(struct sock *sk)
259 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
261 if (rx_flow_is_on(cf_sk))
264 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
265 set_rx_flow_on(cf_sk);
266 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
271 * Copied from unix_dgram_recvmsg, but removed credit checks,
272 * changed locking, address handling and added MSG_TRUNC.
274 static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
275 size_t len, int flags)
278 struct sock *sk = sock->sk;
287 skb = skb_recv_datagram(sk, flags, 0 , &ret);
292 m->msg_flags |= MSG_TRUNC;
296 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
300 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
302 skb_free_datagram(sk, skb);
303 caif_check_flow_release(sk);
311 /* Copied from unix_stream_wait_data, identical except for lock call. */
312 static long caif_stream_data_wait(struct sock *sk, long timeo)
318 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
320 if (!skb_queue_empty(&sk->sk_receive_queue) ||
322 sk->sk_state != CAIF_CONNECTED ||
323 sock_flag(sk, SOCK_DEAD) ||
324 (sk->sk_shutdown & RCV_SHUTDOWN) ||
325 signal_pending(current) ||
329 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
331 timeo = schedule_timeout(timeo);
334 if (sock_flag(sk, SOCK_DEAD))
337 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
340 finish_wait(sk_sleep(sk), &wait);
347 * Copied from unix_stream_recvmsg, but removed credit checks,
348 * changed locking calls, changed address handling.
350 static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
351 size_t size, int flags)
353 struct sock *sk = sock->sk;
364 * Lock the socket to prevent queue disordering
365 * while sleeps in memcpy_tomsg
368 if (sk->sk_state == CAIF_CONNECTING)
372 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
373 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
380 if (sock_flag(sk, SOCK_DEAD)) {
384 skb = skb_dequeue(&sk->sk_receive_queue);
385 caif_check_flow_release(sk);
388 if (copied >= target)
391 * POSIX 1003.1g mandates this order.
393 err = sock_error(sk);
397 if (sk->sk_shutdown & RCV_SHUTDOWN)
401 if (sk->sk_state != CAIF_CONNECTED)
403 if (sock_flag(sk, SOCK_DEAD))
412 caif_read_unlock(sk);
414 timeo = caif_stream_data_wait(sk, timeo);
416 if (signal_pending(current)) {
417 err = sock_intr_errno(timeo);
427 chunk = min_t(unsigned int, skb->len, size);
428 if (memcpy_to_msg(msg, skb->data, chunk)) {
429 skb_queue_head(&sk->sk_receive_queue, skb);
437 /* Mark read part of skb as used */
438 if (!(flags & MSG_PEEK)) {
439 skb_pull(skb, chunk);
441 /* put the skb back if we didn't use it up. */
443 skb_queue_head(&sk->sk_receive_queue, skb);
450 * It is questionable, see note in unix_dgram_recvmsg.
452 /* put message back and return */
453 skb_queue_head(&sk->sk_receive_queue, skb);
457 caif_read_unlock(sk);
460 return copied ? : err;
464 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
465 * CAIF flow-on and sock_writable.
467 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
468 int wait_writeable, long timeo, int *err)
470 struct sock *sk = &cf_sk->sk;
474 if (tx_flow_is_on(cf_sk) &&
475 (!wait_writeable || sock_writeable(&cf_sk->sk)))
481 if (signal_pending(current))
483 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
485 if (sk->sk_shutdown & SHUTDOWN_MASK)
491 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
493 timeo = schedule_timeout(timeo);
495 finish_wait(sk_sleep(sk), &wait);
500 * Transmit a SKB. The device may temporarily request re-transmission
501 * by returning EAGAIN.
503 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
504 int noblock, long timeo)
508 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
509 memset(skb->cb, 0, sizeof(struct caif_payload_info));
510 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
512 if (cf_sk->layer.dn == NULL) {
517 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
520 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
521 static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
524 struct sock *sk = sock->sk;
525 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
528 struct sk_buff *skb = NULL;
532 ret = sock_error(sk);
537 if (msg->msg_flags&MSG_OOB)
541 if (msg->msg_namelen)
545 if (unlikely(msg->msg_iter.iov->iov_base == NULL))
547 noblock = msg->msg_flags & MSG_DONTWAIT;
549 timeo = sock_sndtimeo(sk, noblock);
550 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
556 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
557 sock_flag(sk, SOCK_DEAD) ||
558 (sk->sk_shutdown & RCV_SHUTDOWN))
561 /* Error if trying to write more than maximum frame size. */
563 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
566 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
569 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
571 if (!skb || skb_tailroom(skb) < buffer_size)
574 skb_reserve(skb, cf_sk->headroom);
576 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
580 ret = transmit_skb(skb, cf_sk, noblock, timeo);
582 /* skb is already freed */
592 * Copied from unix_stream_sendmsg and adapted to CAIF:
593 * Changed removed permission handling and added waiting for flow on
594 * and other minor adaptations.
596 static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
599 struct sock *sk = sock->sk;
600 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
607 if (unlikely(msg->msg_flags&MSG_OOB))
610 if (unlikely(msg->msg_namelen))
613 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
614 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
616 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
623 if (size > cf_sk->maxframe)
624 size = cf_sk->maxframe;
626 /* If size is more than half of sndbuf, chop up message */
627 if (size > ((sk->sk_sndbuf >> 1) - 64))
628 size = (sk->sk_sndbuf >> 1) - 64;
630 if (size > SKB_MAX_ALLOC)
631 size = SKB_MAX_ALLOC;
633 skb = sock_alloc_send_skb(sk,
634 size + cf_sk->headroom +
636 msg->msg_flags&MSG_DONTWAIT,
641 skb_reserve(skb, cf_sk->headroom);
643 * If you pass two values to the sock_alloc_send_skb
644 * it tries to grab the large buffer with GFP_NOFS
645 * (which can fail easily), and if it fails grab the
646 * fallback size buffer which is under a page and will
649 size = min_t(int, size, skb_tailroom(skb));
651 err = memcpy_from_msg(skb_put(skb, size), msg, size);
656 err = transmit_skb(skb, cf_sk,
657 msg->msg_flags&MSG_DONTWAIT, timeo);
659 /* skb is already freed */
668 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
669 send_sig(SIGPIPE, current, 0);
675 static int setsockopt(struct socket *sock,
676 int lvl, int opt, char __user *ov, unsigned int ol)
678 struct sock *sk = sock->sk;
679 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
682 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
686 case CAIFSO_LINK_SELECT:
687 if (ol < sizeof(int))
691 if (copy_from_user(&linksel, ov, sizeof(int)))
693 lock_sock(&(cf_sk->sk));
694 cf_sk->conn_req.link_selector = linksel;
695 release_sock(&cf_sk->sk);
698 case CAIFSO_REQ_PARAM:
701 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
703 lock_sock(&(cf_sk->sk));
704 if (ol > sizeof(cf_sk->conn_req.param.data) ||
705 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
706 release_sock(&cf_sk->sk);
709 cf_sk->conn_req.param.size = ol;
710 release_sock(&cf_sk->sk);
724 * caif_connect() - Connect a CAIF Socket
725 * Copied and modified af_irda.c:irda_connect().
727 * Note : by consulting "errno", the user space caller may learn the cause
728 * of the failure. Most of them are visible in the function, others may come
729 * from subroutines called and are listed here :
730 * o -EAFNOSUPPORT: bad socket family or type.
731 * o -ESOCKTNOSUPPORT: bad socket type or protocol
732 * o -EINVAL: bad socket address, or CAIF link type
733 * o -ECONNREFUSED: remote end refused the connection.
734 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
735 * o -EISCONN: already connected.
736 * o -ETIMEDOUT: Connection timed out (send timeout)
737 * o -ENODEV: No link layer to send request
738 * o -ECONNRESET: Received Shutdown indication or lost link layer
739 * o -ENOMEM: Out of memory
742 * o sk_state: holds the CAIF_* protocol state, it's updated by
744 * o sock->state: holds the SS_* socket state and is updated by connect and
747 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
748 int addr_len, int flags)
750 struct sock *sk = sock->sk;
751 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
754 int ifindex, headroom, tailroom;
756 struct net_device *dev;
761 if (uaddr->sa_family != AF_CAIF)
764 switch (sock->state) {
766 /* Normal case, a fresh connect */
767 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
770 switch (sk->sk_state) {
772 sock->state = SS_CONNECTED;
775 case CAIF_DISCONNECTED:
776 /* Reconnect allowed */
778 case CAIF_CONNECTING:
780 if (flags & O_NONBLOCK)
786 caif_assert(sk->sk_state == CAIF_CONNECTED ||
787 sk->sk_state == CAIF_DISCONNECTED);
788 if (sk->sk_shutdown & SHUTDOWN_MASK) {
789 /* Allow re-connect after SHUTDOWN_IND */
790 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
791 caif_free_client(&cf_sk->layer);
794 /* No reconnect on a seqpacket socket */
797 case SS_DISCONNECTING:
799 caif_assert(1); /*Should never happen */
802 sk->sk_state = CAIF_DISCONNECTED;
803 sock->state = SS_UNCONNECTED;
804 sk_stream_kill_queues(&cf_sk->sk);
807 if (addr_len != sizeof(struct sockaddr_caif))
810 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
811 sizeof(struct sockaddr_caif));
813 /* Move to connecting socket, start sending Connect Requests */
814 sock->state = SS_CONNECTING;
815 sk->sk_state = CAIF_CONNECTING;
817 /* Check priority value comming from socket */
818 /* if priority value is out of range it will be ajusted */
819 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
820 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
821 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
822 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
824 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
826 /*ifindex = id of the interface.*/
827 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
829 cf_sk->layer.receive = caif_sktrecv_cb;
831 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
832 &cf_sk->layer, &ifindex, &headroom, &tailroom);
835 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
836 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
842 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
847 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
851 cf_sk->tailroom = tailroom;
852 cf_sk->maxframe = mtu - (headroom + tailroom);
853 if (cf_sk->maxframe < 1) {
854 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
862 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
865 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
869 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
870 sk->sk_state != CAIF_CONNECTING,
874 goto out; /* -ERESTARTSYS */
877 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
879 if (sk->sk_state != CAIF_CONNECTED) {
880 sock->state = SS_UNCONNECTED;
881 err = sock_error(sk);
886 sock->state = SS_CONNECTED;
894 * caif_release() - Disconnect a CAIF Socket
895 * Copied and modified af_irda.c:irda_release().
897 static int caif_release(struct socket *sock)
899 struct sock *sk = sock->sk;
900 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
905 set_tx_flow_off(cf_sk);
908 * Ensure that packets are not queued after this point in time.
909 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
910 * this ensures no packets when sock is dead.
912 spin_lock_bh(&sk->sk_receive_queue.lock);
913 sock_set_flag(sk, SOCK_DEAD);
914 spin_unlock_bh(&sk->sk_receive_queue.lock);
917 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
918 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
920 lock_sock(&(cf_sk->sk));
921 sk->sk_state = CAIF_DISCONNECTED;
922 sk->sk_shutdown = SHUTDOWN_MASK;
924 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
925 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
926 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
929 sk_stream_kill_queues(&cf_sk->sk);
935 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
936 static unsigned int caif_poll(struct file *file,
937 struct socket *sock, poll_table *wait)
939 struct sock *sk = sock->sk;
941 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
943 sock_poll_wait(file, sk_sleep(sk), wait);
946 /* exceptional events? */
949 if (sk->sk_shutdown == SHUTDOWN_MASK)
951 if (sk->sk_shutdown & RCV_SHUTDOWN)
955 if (!skb_queue_empty(&sk->sk_receive_queue) ||
956 (sk->sk_shutdown & RCV_SHUTDOWN))
957 mask |= POLLIN | POLLRDNORM;
960 * we set writable also when the other side has shut down the
961 * connection. This prevents stuck sockets.
963 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
964 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
969 static const struct proto_ops caif_seqpacket_ops = {
971 .owner = THIS_MODULE,
972 .release = caif_release,
973 .bind = sock_no_bind,
974 .connect = caif_connect,
975 .socketpair = sock_no_socketpair,
976 .accept = sock_no_accept,
977 .getname = sock_no_getname,
979 .ioctl = sock_no_ioctl,
980 .listen = sock_no_listen,
981 .shutdown = sock_no_shutdown,
982 .setsockopt = setsockopt,
983 .getsockopt = sock_no_getsockopt,
984 .sendmsg = caif_seqpkt_sendmsg,
985 .recvmsg = caif_seqpkt_recvmsg,
986 .mmap = sock_no_mmap,
987 .sendpage = sock_no_sendpage,
990 static const struct proto_ops caif_stream_ops = {
992 .owner = THIS_MODULE,
993 .release = caif_release,
994 .bind = sock_no_bind,
995 .connect = caif_connect,
996 .socketpair = sock_no_socketpair,
997 .accept = sock_no_accept,
998 .getname = sock_no_getname,
1000 .ioctl = sock_no_ioctl,
1001 .listen = sock_no_listen,
1002 .shutdown = sock_no_shutdown,
1003 .setsockopt = setsockopt,
1004 .getsockopt = sock_no_getsockopt,
1005 .sendmsg = caif_stream_sendmsg,
1006 .recvmsg = caif_stream_recvmsg,
1007 .mmap = sock_no_mmap,
1008 .sendpage = sock_no_sendpage,
1011 /* This function is called when a socket is finally destroyed. */
1012 static void caif_sock_destructor(struct sock *sk)
1014 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1015 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1016 caif_assert(sk_unhashed(sk));
1017 caif_assert(!sk->sk_socket);
1018 if (!sock_flag(sk, SOCK_DEAD)) {
1019 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1022 sk_stream_kill_queues(&cf_sk->sk);
1023 caif_free_client(&cf_sk->layer);
1026 static int caif_create(struct net *net, struct socket *sock, int protocol,
1029 struct sock *sk = NULL;
1030 struct caifsock *cf_sk = NULL;
1031 static struct proto prot = {.name = "PF_CAIF",
1032 .owner = THIS_MODULE,
1033 .obj_size = sizeof(struct caifsock),
1036 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1039 * The sock->type specifies the socket type to use.
1040 * The CAIF socket is a packet stream in the sense
1041 * that it is packet based. CAIF trusts the reliability
1042 * of the link, no resending is implemented.
1044 if (sock->type == SOCK_SEQPACKET)
1045 sock->ops = &caif_seqpacket_ops;
1046 else if (sock->type == SOCK_STREAM)
1047 sock->ops = &caif_stream_ops;
1049 return -ESOCKTNOSUPPORT;
1051 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1052 return -EPROTONOSUPPORT;
1054 * Set the socket state to unconnected. The socket state
1055 * is really not used at all in the net/core or socket.c but the
1056 * initialization makes sure that sock->state is not uninitialized.
1058 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1062 cf_sk = container_of(sk, struct caifsock, sk);
1064 /* Store the protocol */
1065 sk->sk_protocol = (unsigned char) protocol;
1067 /* Initialize default priority for well-known cases */
1070 sk->sk_priority = TC_PRIO_CONTROL;
1073 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1076 sk->sk_priority = TC_PRIO_BESTEFFORT;
1080 * Lock in order to try to stop someone from opening the socket
1083 lock_sock(&(cf_sk->sk));
1085 /* Initialize the nozero default sock structure data. */
1086 sock_init_data(sock, sk);
1087 sk->sk_destruct = caif_sock_destructor;
1089 mutex_init(&cf_sk->readlock); /* single task reading lock */
1090 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1091 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1092 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1094 set_tx_flow_off(cf_sk);
1095 set_rx_flow_on(cf_sk);
1097 /* Set default options on configuration */
1098 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1099 cf_sk->conn_req.protocol = protocol;
1100 release_sock(&cf_sk->sk);
1105 static struct net_proto_family caif_family_ops = {
1107 .create = caif_create,
1108 .owner = THIS_MODULE,
1111 static int __init caif_sktinit_module(void)
1113 int err = sock_register(&caif_family_ops);
1119 static void __exit caif_sktexit_module(void)
1121 sock_unregister(PF_CAIF);
1123 module_init(caif_sktinit_module);
1124 module_exit(caif_sktexit_module);