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 */
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,
60 (void *) &cf_sk->flow_state);
63 static int tx_flow_is_on(struct caifsock *cf_sk)
65 return test_bit(TX_FLOW_ON_BIT,
66 (void *) &cf_sk->flow_state);
69 static void set_rx_flow_off(struct caifsock *cf_sk)
71 clear_bit(RX_FLOW_ON_BIT,
72 (void *) &cf_sk->flow_state);
75 static void set_rx_flow_on(struct caifsock *cf_sk)
77 set_bit(RX_FLOW_ON_BIT,
78 (void *) &cf_sk->flow_state);
81 static void set_tx_flow_off(struct caifsock *cf_sk)
83 clear_bit(TX_FLOW_ON_BIT,
84 (void *) &cf_sk->flow_state);
87 static void set_tx_flow_on(struct caifsock *cf_sk)
89 set_bit(TX_FLOW_ON_BIT,
90 (void *) &cf_sk->flow_state);
93 static void caif_read_lock(struct sock *sk)
95 struct caifsock *cf_sk;
96 cf_sk = container_of(sk, struct caifsock, sk);
97 mutex_lock(&cf_sk->readlock);
100 static void caif_read_unlock(struct sock *sk)
102 struct caifsock *cf_sk;
103 cf_sk = container_of(sk, struct caifsock, sk);
104 mutex_unlock(&cf_sk->readlock);
107 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
109 /* A quarter of full buffer is used a low water mark */
110 return cf_sk->sk.sk_rcvbuf / 4;
113 static void caif_flow_ctrl(struct sock *sk, int mode)
115 struct caifsock *cf_sk;
116 cf_sk = container_of(sk, struct caifsock, sk);
117 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
118 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
122 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
123 * not dropped, but CAIF is sending flow off instead.
125 static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
129 struct sk_buff_head *list = &sk->sk_receive_queue;
130 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
133 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
134 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
135 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
136 atomic_read(&cf_sk->sk.sk_rmem_alloc),
137 sk_rcvbuf_lowwater(cf_sk));
138 set_rx_flow_off(cf_sk);
139 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
142 err = sk_filter(sk, skb);
146 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
147 set_rx_flow_off(cf_sk);
148 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
149 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
152 skb_set_owner_r(skb, sk);
153 spin_lock_irqsave(&list->lock, flags);
154 queued = !sock_flag(sk, SOCK_DEAD);
156 __skb_queue_tail(list, skb);
157 spin_unlock_irqrestore(&list->lock, flags);
160 sk->sk_data_ready(sk);
165 /* Packet Receive Callback function called from CAIF Stack */
166 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
168 struct caifsock *cf_sk;
171 cf_sk = container_of(layr, struct caifsock, layer);
172 skb = cfpkt_tonative(pkt);
174 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
178 caif_queue_rcv_skb(&cf_sk->sk, skb);
182 static void cfsk_hold(struct cflayer *layr)
184 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
185 sock_hold(&cf_sk->sk);
188 static void cfsk_put(struct cflayer *layr)
190 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
191 sock_put(&cf_sk->sk);
194 /* Packet Control Callback function called from CAIF */
195 static void caif_ctrl_cb(struct cflayer *layr,
196 enum caif_ctrlcmd flow,
199 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
201 case CAIF_CTRLCMD_FLOW_ON_IND:
202 /* OK from modem to start sending again */
203 set_tx_flow_on(cf_sk);
204 cf_sk->sk.sk_state_change(&cf_sk->sk);
207 case CAIF_CTRLCMD_FLOW_OFF_IND:
208 /* Modem asks us to shut up */
209 set_tx_flow_off(cf_sk);
210 cf_sk->sk.sk_state_change(&cf_sk->sk);
213 case CAIF_CTRLCMD_INIT_RSP:
214 /* We're now connected */
215 caif_client_register_refcnt(&cf_sk->layer,
216 cfsk_hold, cfsk_put);
217 cf_sk->sk.sk_state = CAIF_CONNECTED;
218 set_tx_flow_on(cf_sk);
219 cf_sk->sk.sk_shutdown = 0;
220 cf_sk->sk.sk_state_change(&cf_sk->sk);
223 case CAIF_CTRLCMD_DEINIT_RSP:
224 /* We're now disconnected */
225 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
226 cf_sk->sk.sk_state_change(&cf_sk->sk);
229 case CAIF_CTRLCMD_INIT_FAIL_RSP:
230 /* Connect request failed */
231 cf_sk->sk.sk_err = ECONNREFUSED;
232 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
233 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
235 * Socket "standards" seems to require POLLOUT to
236 * be set at connect failure.
238 set_tx_flow_on(cf_sk);
239 cf_sk->sk.sk_state_change(&cf_sk->sk);
242 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
243 /* Modem has closed this connection, or device is down. */
244 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
245 cf_sk->sk.sk_err = ECONNRESET;
246 set_rx_flow_on(cf_sk);
247 sk_error_report(&cf_sk->sk);
251 pr_debug("Unexpected flow command %d\n", flow);
255 static void caif_check_flow_release(struct sock *sk)
257 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
259 if (rx_flow_is_on(cf_sk))
262 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
263 set_rx_flow_on(cf_sk);
264 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
269 * Copied from unix_dgram_recvmsg, but removed credit checks,
270 * changed locking, address handling and added MSG_TRUNC.
272 static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
273 size_t len, int flags)
276 struct sock *sk = sock->sk;
285 skb = skb_recv_datagram(sk, flags, &ret);
290 m->msg_flags |= MSG_TRUNC;
294 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
298 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
300 skb_free_datagram(sk, skb);
301 caif_check_flow_release(sk);
309 /* Copied from unix_stream_wait_data, identical except for lock call. */
310 static long caif_stream_data_wait(struct sock *sk, long timeo)
316 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
318 if (!skb_queue_empty(&sk->sk_receive_queue) ||
320 sk->sk_state != CAIF_CONNECTED ||
321 sock_flag(sk, SOCK_DEAD) ||
322 (sk->sk_shutdown & RCV_SHUTDOWN) ||
323 signal_pending(current) ||
327 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
329 timeo = schedule_timeout(timeo);
332 if (sock_flag(sk, SOCK_DEAD))
335 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
338 finish_wait(sk_sleep(sk), &wait);
345 * Copied from unix_stream_recvmsg, but removed credit checks,
346 * changed locking calls, changed address handling.
348 static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
349 size_t size, int flags)
351 struct sock *sk = sock->sk;
362 * Lock the socket to prevent queue disordering
363 * while sleeps in memcpy_tomsg
366 if (sk->sk_state == CAIF_CONNECTING)
370 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
371 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
378 if (sock_flag(sk, SOCK_DEAD)) {
382 skb = skb_dequeue(&sk->sk_receive_queue);
383 caif_check_flow_release(sk);
386 if (copied >= target)
389 * POSIX 1003.1g mandates this order.
391 err = sock_error(sk);
395 if (sk->sk_shutdown & RCV_SHUTDOWN)
399 if (sk->sk_state != CAIF_CONNECTED)
401 if (sock_flag(sk, SOCK_DEAD))
410 caif_read_unlock(sk);
412 timeo = caif_stream_data_wait(sk, timeo);
414 if (signal_pending(current)) {
415 err = sock_intr_errno(timeo);
425 chunk = min_t(unsigned int, skb->len, size);
426 if (memcpy_to_msg(msg, skb->data, chunk)) {
427 skb_queue_head(&sk->sk_receive_queue, skb);
435 /* Mark read part of skb as used */
436 if (!(flags & MSG_PEEK)) {
437 skb_pull(skb, chunk);
439 /* put the skb back if we didn't use it up. */
441 skb_queue_head(&sk->sk_receive_queue, skb);
448 * It is questionable, see note in unix_dgram_recvmsg.
450 /* put message back and return */
451 skb_queue_head(&sk->sk_receive_queue, skb);
455 caif_read_unlock(sk);
458 return copied ? : err;
462 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
463 * CAIF flow-on and sock_writable.
465 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
466 int wait_writeable, long timeo, int *err)
468 struct sock *sk = &cf_sk->sk;
472 if (tx_flow_is_on(cf_sk) &&
473 (!wait_writeable || sock_writeable(&cf_sk->sk)))
479 if (signal_pending(current))
481 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
483 if (sk->sk_shutdown & SHUTDOWN_MASK)
489 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
491 timeo = schedule_timeout(timeo);
493 finish_wait(sk_sleep(sk), &wait);
498 * Transmit a SKB. The device may temporarily request re-transmission
499 * by returning EAGAIN.
501 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
502 int noblock, long timeo)
506 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
507 memset(skb->cb, 0, sizeof(struct caif_payload_info));
508 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
510 if (cf_sk->layer.dn == NULL) {
515 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
518 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
519 static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
522 struct sock *sk = sock->sk;
523 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
526 struct sk_buff *skb = NULL;
530 ret = sock_error(sk);
535 if (msg->msg_flags&MSG_OOB)
539 if (msg->msg_namelen)
543 if (unlikely(msg->msg_iter.nr_segs == 0) ||
544 unlikely(msg->msg_iter.iov->iov_base == NULL))
546 noblock = msg->msg_flags & MSG_DONTWAIT;
548 timeo = sock_sndtimeo(sk, noblock);
549 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
555 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
556 sock_flag(sk, SOCK_DEAD) ||
557 (sk->sk_shutdown & RCV_SHUTDOWN))
560 /* Error if trying to write more than maximum frame size. */
562 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
565 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
568 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
570 if (!skb || skb_tailroom(skb) < buffer_size)
573 skb_reserve(skb, cf_sk->headroom);
575 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
579 ret = transmit_skb(skb, cf_sk, noblock, timeo);
581 /* skb is already freed */
591 * Copied from unix_stream_sendmsg and adapted to CAIF:
592 * Changed removed permission handling and added waiting for flow on
593 * and other minor adaptations.
595 static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
598 struct sock *sk = sock->sk;
599 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
606 if (unlikely(msg->msg_flags&MSG_OOB))
609 if (unlikely(msg->msg_namelen))
612 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
613 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
615 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
622 if (size > cf_sk->maxframe)
623 size = cf_sk->maxframe;
625 /* If size is more than half of sndbuf, chop up message */
626 if (size > ((sk->sk_sndbuf >> 1) - 64))
627 size = (sk->sk_sndbuf >> 1) - 64;
629 if (size > SKB_MAX_ALLOC)
630 size = SKB_MAX_ALLOC;
632 skb = sock_alloc_send_skb(sk,
633 size + cf_sk->headroom +
635 msg->msg_flags&MSG_DONTWAIT,
640 skb_reserve(skb, cf_sk->headroom);
642 * If you pass two values to the sock_alloc_send_skb
643 * it tries to grab the large buffer with GFP_NOFS
644 * (which can fail easily), and if it fails grab the
645 * fallback size buffer which is under a page and will
648 size = min_t(int, size, skb_tailroom(skb));
650 err = memcpy_from_msg(skb_put(skb, size), msg, size);
655 err = transmit_skb(skb, cf_sk,
656 msg->msg_flags&MSG_DONTWAIT, timeo);
658 /* skb is already freed */
667 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
668 send_sig(SIGPIPE, current, 0);
674 static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov,
677 struct sock *sk = sock->sk;
678 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
681 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
685 case CAIFSO_LINK_SELECT:
686 if (ol < sizeof(int))
690 if (copy_from_sockptr(&linksel, ov, sizeof(int)))
692 lock_sock(&(cf_sk->sk));
693 cf_sk->conn_req.link_selector = linksel;
694 release_sock(&cf_sk->sk);
697 case CAIFSO_REQ_PARAM:
700 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
702 lock_sock(&(cf_sk->sk));
703 if (ol > sizeof(cf_sk->conn_req.param.data) ||
704 copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) {
705 release_sock(&cf_sk->sk);
708 cf_sk->conn_req.param.size = ol;
709 release_sock(&cf_sk->sk);
723 * caif_connect() - Connect a CAIF Socket
724 * Copied and modified af_irda.c:irda_connect().
726 * Note : by consulting "errno", the user space caller may learn the cause
727 * of the failure. Most of them are visible in the function, others may come
728 * from subroutines called and are listed here :
729 * o -EAFNOSUPPORT: bad socket family or type.
730 * o -ESOCKTNOSUPPORT: bad socket type or protocol
731 * o -EINVAL: bad socket address, or CAIF link type
732 * o -ECONNREFUSED: remote end refused the connection.
733 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
734 * o -EISCONN: already connected.
735 * o -ETIMEDOUT: Connection timed out (send timeout)
736 * o -ENODEV: No link layer to send request
737 * o -ECONNRESET: Received Shutdown indication or lost link layer
738 * o -ENOMEM: Out of memory
741 * o sk_state: holds the CAIF_* protocol state, it's updated by
743 * o sock->state: holds the SS_* socket state and is updated by connect and
746 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
747 int addr_len, int flags)
749 struct sock *sk = sock->sk;
750 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
753 int ifindex, headroom, tailroom;
755 struct net_device *dev;
760 if (addr_len < offsetofend(struct sockaddr, sa_family))
764 if (uaddr->sa_family != AF_CAIF)
767 switch (sock->state) {
769 /* Normal case, a fresh connect */
770 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
773 switch (sk->sk_state) {
775 sock->state = SS_CONNECTED;
778 case CAIF_DISCONNECTED:
779 /* Reconnect allowed */
781 case CAIF_CONNECTING:
783 if (flags & O_NONBLOCK)
789 caif_assert(sk->sk_state == CAIF_CONNECTED ||
790 sk->sk_state == CAIF_DISCONNECTED);
791 if (sk->sk_shutdown & SHUTDOWN_MASK) {
792 /* Allow re-connect after SHUTDOWN_IND */
793 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
794 caif_free_client(&cf_sk->layer);
797 /* No reconnect on a seqpacket socket */
800 case SS_DISCONNECTING:
802 caif_assert(1); /*Should never happen */
805 sk->sk_state = CAIF_DISCONNECTED;
806 sock->state = SS_UNCONNECTED;
807 sk_stream_kill_queues(&cf_sk->sk);
810 if (addr_len != sizeof(struct sockaddr_caif))
813 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
814 sizeof(struct sockaddr_caif));
816 /* Move to connecting socket, start sending Connect Requests */
817 sock->state = SS_CONNECTING;
818 sk->sk_state = CAIF_CONNECTING;
820 /* Check priority value comming from socket */
821 /* if priority value is out of range it will be ajusted */
822 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
823 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
824 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
825 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
827 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
829 /*ifindex = id of the interface.*/
830 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
832 cf_sk->layer.receive = caif_sktrecv_cb;
834 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
835 &cf_sk->layer, &ifindex, &headroom, &tailroom);
838 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
839 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
845 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
850 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
854 cf_sk->tailroom = tailroom;
855 cf_sk->maxframe = mtu - (headroom + tailroom);
856 if (cf_sk->maxframe < 1) {
857 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
865 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
868 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
872 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
873 sk->sk_state != CAIF_CONNECTING,
877 goto out; /* -ERESTARTSYS */
880 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
882 if (sk->sk_state != CAIF_CONNECTED) {
883 sock->state = SS_UNCONNECTED;
884 err = sock_error(sk);
889 sock->state = SS_CONNECTED;
897 * caif_release() - Disconnect a CAIF Socket
898 * Copied and modified af_irda.c:irda_release().
900 static int caif_release(struct socket *sock)
902 struct sock *sk = sock->sk;
903 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
908 set_tx_flow_off(cf_sk);
911 * Ensure that packets are not queued after this point in time.
912 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
913 * this ensures no packets when sock is dead.
915 spin_lock_bh(&sk->sk_receive_queue.lock);
916 sock_set_flag(sk, SOCK_DEAD);
917 spin_unlock_bh(&sk->sk_receive_queue.lock);
920 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
921 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
923 lock_sock(&(cf_sk->sk));
924 sk->sk_state = CAIF_DISCONNECTED;
925 sk->sk_shutdown = SHUTDOWN_MASK;
927 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
928 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
929 wake_up_interruptible_poll(sk_sleep(sk), EPOLLERR|EPOLLHUP);
932 sk_stream_kill_queues(&cf_sk->sk);
938 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
939 static __poll_t caif_poll(struct file *file,
940 struct socket *sock, poll_table *wait)
942 struct sock *sk = sock->sk;
944 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
946 sock_poll_wait(file, sock, wait);
949 /* exceptional events? */
952 if (sk->sk_shutdown == SHUTDOWN_MASK)
954 if (sk->sk_shutdown & RCV_SHUTDOWN)
958 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
959 (sk->sk_shutdown & RCV_SHUTDOWN))
960 mask |= EPOLLIN | EPOLLRDNORM;
963 * we set writable also when the other side has shut down the
964 * connection. This prevents stuck sockets.
966 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
967 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
972 static const struct proto_ops caif_seqpacket_ops = {
974 .owner = THIS_MODULE,
975 .release = caif_release,
976 .bind = sock_no_bind,
977 .connect = caif_connect,
978 .socketpair = sock_no_socketpair,
979 .accept = sock_no_accept,
980 .getname = sock_no_getname,
982 .ioctl = sock_no_ioctl,
983 .listen = sock_no_listen,
984 .shutdown = sock_no_shutdown,
985 .setsockopt = setsockopt,
986 .sendmsg = caif_seqpkt_sendmsg,
987 .recvmsg = caif_seqpkt_recvmsg,
988 .mmap = sock_no_mmap,
989 .sendpage = sock_no_sendpage,
992 static const struct proto_ops caif_stream_ops = {
994 .owner = THIS_MODULE,
995 .release = caif_release,
996 .bind = sock_no_bind,
997 .connect = caif_connect,
998 .socketpair = sock_no_socketpair,
999 .accept = sock_no_accept,
1000 .getname = sock_no_getname,
1002 .ioctl = sock_no_ioctl,
1003 .listen = sock_no_listen,
1004 .shutdown = sock_no_shutdown,
1005 .setsockopt = setsockopt,
1006 .sendmsg = caif_stream_sendmsg,
1007 .recvmsg = caif_stream_recvmsg,
1008 .mmap = sock_no_mmap,
1009 .sendpage = sock_no_sendpage,
1012 /* This function is called when a socket is finally destroyed. */
1013 static void caif_sock_destructor(struct sock *sk)
1015 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1016 caif_assert(!refcount_read(&sk->sk_wmem_alloc));
1017 caif_assert(sk_unhashed(sk));
1018 caif_assert(!sk->sk_socket);
1019 if (!sock_flag(sk, SOCK_DEAD)) {
1020 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1023 sk_stream_kill_queues(&cf_sk->sk);
1024 caif_free_client(&cf_sk->layer);
1027 static int caif_create(struct net *net, struct socket *sock, int protocol,
1030 struct sock *sk = NULL;
1031 struct caifsock *cf_sk = NULL;
1032 static struct proto prot = {.name = "PF_CAIF",
1033 .owner = THIS_MODULE,
1034 .obj_size = sizeof(struct caifsock),
1035 .useroffset = offsetof(struct caifsock, conn_req.param),
1036 .usersize = sizeof_field(struct caifsock, conn_req.param)
1039 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1042 * The sock->type specifies the socket type to use.
1043 * The CAIF socket is a packet stream in the sense
1044 * that it is packet based. CAIF trusts the reliability
1045 * of the link, no resending is implemented.
1047 if (sock->type == SOCK_SEQPACKET)
1048 sock->ops = &caif_seqpacket_ops;
1049 else if (sock->type == SOCK_STREAM)
1050 sock->ops = &caif_stream_ops;
1052 return -ESOCKTNOSUPPORT;
1054 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1055 return -EPROTONOSUPPORT;
1057 * Set the socket state to unconnected. The socket state
1058 * is really not used at all in the net/core or socket.c but the
1059 * initialization makes sure that sock->state is not uninitialized.
1061 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern);
1065 cf_sk = container_of(sk, struct caifsock, sk);
1067 /* Store the protocol */
1068 sk->sk_protocol = (unsigned char) protocol;
1070 /* Initialize default priority for well-known cases */
1073 sk->sk_priority = TC_PRIO_CONTROL;
1076 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1079 sk->sk_priority = TC_PRIO_BESTEFFORT;
1083 * Lock in order to try to stop someone from opening the socket
1086 lock_sock(&(cf_sk->sk));
1088 /* Initialize the nozero default sock structure data. */
1089 sock_init_data(sock, sk);
1090 sk->sk_destruct = caif_sock_destructor;
1092 mutex_init(&cf_sk->readlock); /* single task reading lock */
1093 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1094 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1095 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1097 set_tx_flow_off(cf_sk);
1098 set_rx_flow_on(cf_sk);
1100 /* Set default options on configuration */
1101 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1102 cf_sk->conn_req.protocol = protocol;
1103 release_sock(&cf_sk->sk);
1108 static const struct net_proto_family caif_family_ops = {
1110 .create = caif_create,
1111 .owner = THIS_MODULE,
1114 static int __init caif_sktinit_module(void)
1116 return 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);