1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) ST-Ericsson AB 2010
4 * Author: Sjur Brendeland
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
9 #include <linux/filter.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/sched/signal.h>
14 #include <linux/spinlock.h>
15 #include <linux/mutex.h>
16 #include <linux/list.h>
17 #include <linux/wait.h>
18 #include <linux/poll.h>
19 #include <linux/tcp.h>
20 #include <linux/uaccess.h>
21 #include <linux/debugfs.h>
22 #include <linux/caif/caif_socket.h>
23 #include <linux/pkt_sched.h>
25 #include <net/tcp_states.h>
26 #include <net/caif/caif_layer.h>
27 #include <net/caif/caif_dev.h>
28 #include <net/caif/cfpkt.h>
30 MODULE_LICENSE("GPL");
31 MODULE_ALIAS_NETPROTO(AF_CAIF);
34 * CAIF state is re-using the TCP socket states.
35 * caif_states stored in sk_state reflect the state as reported by
36 * the CAIF stack, while sk_socket->state is the state of the socket.
39 CAIF_CONNECTED = TCP_ESTABLISHED,
40 CAIF_CONNECTING = TCP_SYN_SENT,
41 CAIF_DISCONNECTED = TCP_CLOSE
44 #define TX_FLOW_ON_BIT 1
45 #define RX_FLOW_ON_BIT 2
48 struct sock sk; /* must be first member */
50 unsigned long flow_state;
51 struct caif_connect_request conn_req;
52 struct mutex readlock;
53 struct dentry *debugfs_socket_dir;
54 int headroom, tailroom, maxframe;
57 static int rx_flow_is_on(struct caifsock *cf_sk)
59 return test_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
62 static int tx_flow_is_on(struct caifsock *cf_sk)
64 return test_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
67 static void set_rx_flow_off(struct caifsock *cf_sk)
69 clear_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
72 static void set_rx_flow_on(struct caifsock *cf_sk)
74 set_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
77 static void set_tx_flow_off(struct caifsock *cf_sk)
79 clear_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
82 static void set_tx_flow_on(struct caifsock *cf_sk)
84 set_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
87 static void caif_read_lock(struct sock *sk)
89 struct caifsock *cf_sk;
90 cf_sk = container_of(sk, struct caifsock, sk);
91 mutex_lock(&cf_sk->readlock);
94 static void caif_read_unlock(struct sock *sk)
96 struct caifsock *cf_sk;
97 cf_sk = container_of(sk, struct caifsock, sk);
98 mutex_unlock(&cf_sk->readlock);
101 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
103 /* A quarter of full buffer is used a low water mark */
104 return cf_sk->sk.sk_rcvbuf / 4;
107 static void caif_flow_ctrl(struct sock *sk, int mode)
109 struct caifsock *cf_sk;
110 cf_sk = container_of(sk, struct caifsock, sk);
111 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
112 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
116 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
117 * not dropped, but CAIF is sending flow off instead.
119 static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
123 struct sk_buff_head *list = &sk->sk_receive_queue;
124 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
127 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
128 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
129 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
130 atomic_read(&cf_sk->sk.sk_rmem_alloc),
131 sk_rcvbuf_lowwater(cf_sk));
132 set_rx_flow_off(cf_sk);
133 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
136 err = sk_filter(sk, skb);
140 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
141 set_rx_flow_off(cf_sk);
142 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
143 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
146 skb_set_owner_r(skb, sk);
147 spin_lock_irqsave(&list->lock, flags);
148 queued = !sock_flag(sk, SOCK_DEAD);
150 __skb_queue_tail(list, skb);
151 spin_unlock_irqrestore(&list->lock, flags);
154 sk->sk_data_ready(sk);
159 /* Packet Receive Callback function called from CAIF Stack */
160 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
162 struct caifsock *cf_sk;
165 cf_sk = container_of(layr, struct caifsock, layer);
166 skb = cfpkt_tonative(pkt);
168 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
172 caif_queue_rcv_skb(&cf_sk->sk, skb);
176 static void cfsk_hold(struct cflayer *layr)
178 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
179 sock_hold(&cf_sk->sk);
182 static void cfsk_put(struct cflayer *layr)
184 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
185 sock_put(&cf_sk->sk);
188 /* Packet Control Callback function called from CAIF */
189 static void caif_ctrl_cb(struct cflayer *layr,
190 enum caif_ctrlcmd flow,
193 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
195 case CAIF_CTRLCMD_FLOW_ON_IND:
196 /* OK from modem to start sending again */
197 set_tx_flow_on(cf_sk);
198 cf_sk->sk.sk_state_change(&cf_sk->sk);
201 case CAIF_CTRLCMD_FLOW_OFF_IND:
202 /* Modem asks us to shut up */
203 set_tx_flow_off(cf_sk);
204 cf_sk->sk.sk_state_change(&cf_sk->sk);
207 case CAIF_CTRLCMD_INIT_RSP:
208 /* We're now connected */
209 caif_client_register_refcnt(&cf_sk->layer,
210 cfsk_hold, cfsk_put);
211 cf_sk->sk.sk_state = CAIF_CONNECTED;
212 set_tx_flow_on(cf_sk);
213 cf_sk->sk.sk_shutdown = 0;
214 cf_sk->sk.sk_state_change(&cf_sk->sk);
217 case CAIF_CTRLCMD_DEINIT_RSP:
218 /* We're now disconnected */
219 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
220 cf_sk->sk.sk_state_change(&cf_sk->sk);
223 case CAIF_CTRLCMD_INIT_FAIL_RSP:
224 /* Connect request failed */
225 cf_sk->sk.sk_err = ECONNREFUSED;
226 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
227 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
229 * Socket "standards" seems to require POLLOUT to
230 * be set at connect failure.
232 set_tx_flow_on(cf_sk);
233 cf_sk->sk.sk_state_change(&cf_sk->sk);
236 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
237 /* Modem has closed this connection, or device is down. */
238 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
239 cf_sk->sk.sk_err = ECONNRESET;
240 set_rx_flow_on(cf_sk);
241 sk_error_report(&cf_sk->sk);
245 pr_debug("Unexpected flow command %d\n", flow);
249 static void caif_check_flow_release(struct sock *sk)
251 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
253 if (rx_flow_is_on(cf_sk))
256 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
257 set_rx_flow_on(cf_sk);
258 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
263 * Copied from unix_dgram_recvmsg, but removed credit checks,
264 * changed locking, address handling and added MSG_TRUNC.
266 static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
267 size_t len, int flags)
270 struct sock *sk = sock->sk;
279 skb = skb_recv_datagram(sk, flags, &ret);
284 m->msg_flags |= MSG_TRUNC;
288 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
292 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
294 skb_free_datagram(sk, skb);
295 caif_check_flow_release(sk);
303 /* Copied from unix_stream_wait_data, identical except for lock call. */
304 static long caif_stream_data_wait(struct sock *sk, long timeo)
310 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
312 if (!skb_queue_empty(&sk->sk_receive_queue) ||
314 sk->sk_state != CAIF_CONNECTED ||
315 sock_flag(sk, SOCK_DEAD) ||
316 (sk->sk_shutdown & RCV_SHUTDOWN) ||
317 signal_pending(current) ||
321 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
323 timeo = schedule_timeout(timeo);
326 if (sock_flag(sk, SOCK_DEAD))
329 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
332 finish_wait(sk_sleep(sk), &wait);
339 * Copied from unix_stream_recvmsg, but removed credit checks,
340 * changed locking calls, changed address handling.
342 static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
343 size_t size, int flags)
345 struct sock *sk = sock->sk;
356 * Lock the socket to prevent queue disordering
357 * while sleeps in memcpy_tomsg
360 if (sk->sk_state == CAIF_CONNECTING)
364 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
365 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
372 if (sock_flag(sk, SOCK_DEAD)) {
376 skb = skb_dequeue(&sk->sk_receive_queue);
377 caif_check_flow_release(sk);
380 if (copied >= target)
383 * POSIX 1003.1g mandates this order.
385 err = sock_error(sk);
389 if (sk->sk_shutdown & RCV_SHUTDOWN)
393 if (sk->sk_state != CAIF_CONNECTED)
395 if (sock_flag(sk, SOCK_DEAD))
404 caif_read_unlock(sk);
406 timeo = caif_stream_data_wait(sk, timeo);
408 if (signal_pending(current)) {
409 err = sock_intr_errno(timeo);
419 chunk = min_t(unsigned int, skb->len, size);
420 if (memcpy_to_msg(msg, skb->data, chunk)) {
421 skb_queue_head(&sk->sk_receive_queue, skb);
429 /* Mark read part of skb as used */
430 if (!(flags & MSG_PEEK)) {
431 skb_pull(skb, chunk);
433 /* put the skb back if we didn't use it up. */
435 skb_queue_head(&sk->sk_receive_queue, skb);
442 * It is questionable, see note in unix_dgram_recvmsg.
444 /* put message back and return */
445 skb_queue_head(&sk->sk_receive_queue, skb);
449 caif_read_unlock(sk);
452 return copied ? : err;
456 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
457 * CAIF flow-on and sock_writable.
459 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
460 int wait_writeable, long timeo, int *err)
462 struct sock *sk = &cf_sk->sk;
466 if (tx_flow_is_on(cf_sk) &&
467 (!wait_writeable || sock_writeable(&cf_sk->sk)))
473 if (signal_pending(current))
475 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
477 if (sk->sk_shutdown & SHUTDOWN_MASK)
483 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
485 timeo = schedule_timeout(timeo);
487 finish_wait(sk_sleep(sk), &wait);
492 * Transmit a SKB. The device may temporarily request re-transmission
493 * by returning EAGAIN.
495 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
496 int noblock, long timeo)
500 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
501 memset(skb->cb, 0, sizeof(struct caif_payload_info));
502 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
504 if (cf_sk->layer.dn == NULL) {
509 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
512 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
513 static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
516 struct sock *sk = sock->sk;
517 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
520 struct sk_buff *skb = NULL;
524 ret = sock_error(sk);
529 if (msg->msg_flags&MSG_OOB)
533 if (msg->msg_namelen)
537 if (unlikely(msg->msg_iter.nr_segs == 0) ||
538 unlikely(msg->msg_iter.iov->iov_base == NULL))
540 noblock = msg->msg_flags & MSG_DONTWAIT;
542 timeo = sock_sndtimeo(sk, noblock);
543 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
549 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
550 sock_flag(sk, SOCK_DEAD) ||
551 (sk->sk_shutdown & RCV_SHUTDOWN))
554 /* Error if trying to write more than maximum frame size. */
556 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
559 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
562 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
564 if (!skb || skb_tailroom(skb) < buffer_size)
567 skb_reserve(skb, cf_sk->headroom);
569 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
573 ret = transmit_skb(skb, cf_sk, noblock, timeo);
575 /* skb is already freed */
585 * Copied from unix_stream_sendmsg and adapted to CAIF:
586 * Changed removed permission handling and added waiting for flow on
587 * and other minor adaptations.
589 static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
592 struct sock *sk = sock->sk;
593 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
600 if (unlikely(msg->msg_flags&MSG_OOB))
603 if (unlikely(msg->msg_namelen))
606 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
607 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
609 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
616 if (size > cf_sk->maxframe)
617 size = cf_sk->maxframe;
619 /* If size is more than half of sndbuf, chop up message */
620 if (size > ((sk->sk_sndbuf >> 1) - 64))
621 size = (sk->sk_sndbuf >> 1) - 64;
623 if (size > SKB_MAX_ALLOC)
624 size = SKB_MAX_ALLOC;
626 skb = sock_alloc_send_skb(sk,
627 size + cf_sk->headroom +
629 msg->msg_flags&MSG_DONTWAIT,
634 skb_reserve(skb, cf_sk->headroom);
636 * If you pass two values to the sock_alloc_send_skb
637 * it tries to grab the large buffer with GFP_NOFS
638 * (which can fail easily), and if it fails grab the
639 * fallback size buffer which is under a page and will
642 size = min_t(int, size, skb_tailroom(skb));
644 err = memcpy_from_msg(skb_put(skb, size), msg, size);
649 err = transmit_skb(skb, cf_sk,
650 msg->msg_flags&MSG_DONTWAIT, timeo);
652 /* skb is already freed */
661 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
662 send_sig(SIGPIPE, current, 0);
668 static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov,
671 struct sock *sk = sock->sk;
672 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
675 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
679 case CAIFSO_LINK_SELECT:
680 if (ol < sizeof(int))
684 if (copy_from_sockptr(&linksel, ov, sizeof(int)))
686 lock_sock(&(cf_sk->sk));
687 cf_sk->conn_req.link_selector = linksel;
688 release_sock(&cf_sk->sk);
691 case CAIFSO_REQ_PARAM:
694 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
696 lock_sock(&(cf_sk->sk));
697 if (ol > sizeof(cf_sk->conn_req.param.data) ||
698 copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) {
699 release_sock(&cf_sk->sk);
702 cf_sk->conn_req.param.size = ol;
703 release_sock(&cf_sk->sk);
717 * caif_connect() - Connect a CAIF Socket
718 * Copied and modified af_irda.c:irda_connect().
720 * Note : by consulting "errno", the user space caller may learn the cause
721 * of the failure. Most of them are visible in the function, others may come
722 * from subroutines called and are listed here :
723 * o -EAFNOSUPPORT: bad socket family or type.
724 * o -ESOCKTNOSUPPORT: bad socket type or protocol
725 * o -EINVAL: bad socket address, or CAIF link type
726 * o -ECONNREFUSED: remote end refused the connection.
727 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
728 * o -EISCONN: already connected.
729 * o -ETIMEDOUT: Connection timed out (send timeout)
730 * o -ENODEV: No link layer to send request
731 * o -ECONNRESET: Received Shutdown indication or lost link layer
732 * o -ENOMEM: Out of memory
735 * o sk_state: holds the CAIF_* protocol state, it's updated by
737 * o sock->state: holds the SS_* socket state and is updated by connect and
740 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
741 int addr_len, int flags)
743 struct sock *sk = sock->sk;
744 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
747 int ifindex, headroom, tailroom;
749 struct net_device *dev;
754 if (addr_len < offsetofend(struct sockaddr, sa_family))
758 if (uaddr->sa_family != AF_CAIF)
761 switch (sock->state) {
763 /* Normal case, a fresh connect */
764 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
767 switch (sk->sk_state) {
769 sock->state = SS_CONNECTED;
772 case CAIF_DISCONNECTED:
773 /* Reconnect allowed */
775 case CAIF_CONNECTING:
777 if (flags & O_NONBLOCK)
783 caif_assert(sk->sk_state == CAIF_CONNECTED ||
784 sk->sk_state == CAIF_DISCONNECTED);
785 if (sk->sk_shutdown & SHUTDOWN_MASK) {
786 /* Allow re-connect after SHUTDOWN_IND */
787 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
788 caif_free_client(&cf_sk->layer);
791 /* No reconnect on a seqpacket socket */
794 case SS_DISCONNECTING:
796 caif_assert(1); /*Should never happen */
799 sk->sk_state = CAIF_DISCONNECTED;
800 sock->state = SS_UNCONNECTED;
801 sk_stream_kill_queues(&cf_sk->sk);
804 if (addr_len != sizeof(struct sockaddr_caif))
807 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
808 sizeof(struct sockaddr_caif));
810 /* Move to connecting socket, start sending Connect Requests */
811 sock->state = SS_CONNECTING;
812 sk->sk_state = CAIF_CONNECTING;
814 /* Check priority value comming from socket */
815 /* if priority value is out of range it will be ajusted */
816 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
817 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
818 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
819 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
821 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
823 /*ifindex = id of the interface.*/
824 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
826 cf_sk->layer.receive = caif_sktrecv_cb;
828 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
829 &cf_sk->layer, &ifindex, &headroom, &tailroom);
832 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
833 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
839 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
844 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
848 cf_sk->tailroom = tailroom;
849 cf_sk->maxframe = mtu - (headroom + tailroom);
850 if (cf_sk->maxframe < 1) {
851 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
859 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
862 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
866 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
867 sk->sk_state != CAIF_CONNECTING,
871 goto out; /* -ERESTARTSYS */
874 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
876 if (sk->sk_state != CAIF_CONNECTED) {
877 sock->state = SS_UNCONNECTED;
878 err = sock_error(sk);
883 sock->state = SS_CONNECTED;
891 * caif_release() - Disconnect a CAIF Socket
892 * Copied and modified af_irda.c:irda_release().
894 static int caif_release(struct socket *sock)
896 struct sock *sk = sock->sk;
897 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
902 set_tx_flow_off(cf_sk);
905 * Ensure that packets are not queued after this point in time.
906 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
907 * this ensures no packets when sock is dead.
909 spin_lock_bh(&sk->sk_receive_queue.lock);
910 sock_set_flag(sk, SOCK_DEAD);
911 spin_unlock_bh(&sk->sk_receive_queue.lock);
914 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
915 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
917 lock_sock(&(cf_sk->sk));
918 sk->sk_state = CAIF_DISCONNECTED;
919 sk->sk_shutdown = SHUTDOWN_MASK;
921 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
922 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
923 wake_up_interruptible_poll(sk_sleep(sk), EPOLLERR|EPOLLHUP);
926 sk_stream_kill_queues(&cf_sk->sk);
932 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
933 static __poll_t caif_poll(struct file *file,
934 struct socket *sock, poll_table *wait)
936 struct sock *sk = sock->sk;
938 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
940 sock_poll_wait(file, sock, wait);
943 /* exceptional events? */
946 if (sk->sk_shutdown == SHUTDOWN_MASK)
948 if (sk->sk_shutdown & RCV_SHUTDOWN)
952 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
953 (sk->sk_shutdown & RCV_SHUTDOWN))
954 mask |= EPOLLIN | EPOLLRDNORM;
957 * we set writable also when the other side has shut down the
958 * connection. This prevents stuck sockets.
960 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
961 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
966 static const struct proto_ops caif_seqpacket_ops = {
968 .owner = THIS_MODULE,
969 .release = caif_release,
970 .bind = sock_no_bind,
971 .connect = caif_connect,
972 .socketpair = sock_no_socketpair,
973 .accept = sock_no_accept,
974 .getname = sock_no_getname,
976 .ioctl = sock_no_ioctl,
977 .listen = sock_no_listen,
978 .shutdown = sock_no_shutdown,
979 .setsockopt = setsockopt,
980 .sendmsg = caif_seqpkt_sendmsg,
981 .recvmsg = caif_seqpkt_recvmsg,
982 .mmap = sock_no_mmap,
983 .sendpage = sock_no_sendpage,
986 static const struct proto_ops caif_stream_ops = {
988 .owner = THIS_MODULE,
989 .release = caif_release,
990 .bind = sock_no_bind,
991 .connect = caif_connect,
992 .socketpair = sock_no_socketpair,
993 .accept = sock_no_accept,
994 .getname = sock_no_getname,
996 .ioctl = sock_no_ioctl,
997 .listen = sock_no_listen,
998 .shutdown = sock_no_shutdown,
999 .setsockopt = setsockopt,
1000 .sendmsg = caif_stream_sendmsg,
1001 .recvmsg = caif_stream_recvmsg,
1002 .mmap = sock_no_mmap,
1003 .sendpage = sock_no_sendpage,
1006 /* This function is called when a socket is finally destroyed. */
1007 static void caif_sock_destructor(struct sock *sk)
1009 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1010 caif_assert(!refcount_read(&sk->sk_wmem_alloc));
1011 caif_assert(sk_unhashed(sk));
1012 caif_assert(!sk->sk_socket);
1013 if (!sock_flag(sk, SOCK_DEAD)) {
1014 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1017 sk_stream_kill_queues(&cf_sk->sk);
1018 caif_free_client(&cf_sk->layer);
1021 static int caif_create(struct net *net, struct socket *sock, int protocol,
1024 struct sock *sk = NULL;
1025 struct caifsock *cf_sk = NULL;
1026 static struct proto prot = {.name = "PF_CAIF",
1027 .owner = THIS_MODULE,
1028 .obj_size = sizeof(struct caifsock),
1029 .useroffset = offsetof(struct caifsock, conn_req.param),
1030 .usersize = sizeof_field(struct caifsock, conn_req.param)
1033 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1036 * The sock->type specifies the socket type to use.
1037 * The CAIF socket is a packet stream in the sense
1038 * that it is packet based. CAIF trusts the reliability
1039 * of the link, no resending is implemented.
1041 if (sock->type == SOCK_SEQPACKET)
1042 sock->ops = &caif_seqpacket_ops;
1043 else if (sock->type == SOCK_STREAM)
1044 sock->ops = &caif_stream_ops;
1046 return -ESOCKTNOSUPPORT;
1048 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1049 return -EPROTONOSUPPORT;
1051 * Set the socket state to unconnected. The socket state
1052 * is really not used at all in the net/core or socket.c but the
1053 * initialization makes sure that sock->state is not uninitialized.
1055 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern);
1059 cf_sk = container_of(sk, struct caifsock, sk);
1061 /* Store the protocol */
1062 sk->sk_protocol = (unsigned char) protocol;
1064 /* Initialize default priority for well-known cases */
1067 sk->sk_priority = TC_PRIO_CONTROL;
1070 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1073 sk->sk_priority = TC_PRIO_BESTEFFORT;
1077 * Lock in order to try to stop someone from opening the socket
1080 lock_sock(&(cf_sk->sk));
1082 /* Initialize the nozero default sock structure data. */
1083 sock_init_data(sock, sk);
1084 sk->sk_destruct = caif_sock_destructor;
1086 mutex_init(&cf_sk->readlock); /* single task reading lock */
1087 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1088 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1089 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1091 set_tx_flow_off(cf_sk);
1092 set_rx_flow_on(cf_sk);
1094 /* Set default options on configuration */
1095 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1096 cf_sk->conn_req.protocol = protocol;
1097 release_sock(&cf_sk->sk);
1102 static const struct net_proto_family caif_family_ops = {
1104 .create = caif_create,
1105 .owner = THIS_MODULE,
1108 static int __init caif_sktinit_module(void)
1110 return sock_register(&caif_family_ops);
1113 static void __exit caif_sktexit_module(void)
1115 sock_unregister(PF_CAIF);
1117 module_init(caif_sktinit_module);
1118 module_exit(caif_sktexit_module);