caif_socket.c 30.0 KB
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/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

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#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/tcp.h>
#include <linux/uaccess.h>
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#include <linux/debugfs.h>
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#include <linux/caif/caif_socket.h>
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#include <asm/atomic.h>
#include <net/sock.h>
#include <net/tcp_states.h>
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#include <net/caif/caif_layer.h>
#include <net/caif/caif_dev.h>
#include <net/caif/cfpkt.h>

MODULE_LICENSE("GPL");
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MODULE_ALIAS_NETPROTO(AF_CAIF);

/*
 * CAIF state is re-using the TCP socket states.
 * caif_states stored in sk_state reflect the state as reported by
 * the CAIF stack, while sk_socket->state is the state of the socket.
 */
enum caif_states {
	CAIF_CONNECTED		= TCP_ESTABLISHED,
	CAIF_CONNECTING	= TCP_SYN_SENT,
	CAIF_DISCONNECTED	= TCP_CLOSE
};

#define TX_FLOW_ON_BIT	1
#define RX_FLOW_ON_BIT	2
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static struct dentry *debugfsdir;

#ifdef CONFIG_DEBUG_FS
struct debug_fs_counter {
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	atomic_t caif_nr_socks;
	atomic_t num_connect_req;
	atomic_t num_connect_resp;
	atomic_t num_connect_fail_resp;
	atomic_t num_disconnect;
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	atomic_t num_remote_shutdown_ind;
	atomic_t num_tx_flow_off_ind;
	atomic_t num_tx_flow_on_ind;
	atomic_t num_rx_flow_off;
	atomic_t num_rx_flow_on;
};
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static struct debug_fs_counter cnt;
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#define	dbfs_atomic_inc(v) atomic_inc(v)
#define	dbfs_atomic_dec(v) atomic_dec(v)
#else
#define	dbfs_atomic_inc(v)
#define	dbfs_atomic_dec(v)
#endif

struct caifsock {
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	struct sock sk; /* must be first member */
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	struct cflayer layer;
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	char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
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	u32 flow_state;
	struct caif_connect_request conn_req;
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	struct mutex readlock;
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	struct dentry *debugfs_socket_dir;
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	int headroom, tailroom, maxframe;
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};

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static int rx_flow_is_on(struct caifsock *cf_sk)
{
	return test_bit(RX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}

static int tx_flow_is_on(struct caifsock *cf_sk)
{
	return test_bit(TX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}
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static void set_rx_flow_off(struct caifsock *cf_sk)
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{
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	 clear_bit(RX_FLOW_ON_BIT,
		 (void *) &cf_sk->flow_state);
}
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static void set_rx_flow_on(struct caifsock *cf_sk)
{
	 set_bit(RX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}
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static void set_tx_flow_off(struct caifsock *cf_sk)
{
	 clear_bit(TX_FLOW_ON_BIT,
		(void *) &cf_sk->flow_state);
}
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static void set_tx_flow_on(struct caifsock *cf_sk)
{
	 set_bit(TX_FLOW_ON_BIT,
		(void *) &cf_sk->flow_state);
}
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static void caif_read_lock(struct sock *sk)
{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
	mutex_lock(&cf_sk->readlock);
}
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static void caif_read_unlock(struct sock *sk)
{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
	mutex_unlock(&cf_sk->readlock);
}
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static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
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{
	/* A quarter of full buffer is used a low water mark */
	return cf_sk->sk.sk_rcvbuf / 4;
}
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static void caif_flow_ctrl(struct sock *sk, int mode)
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{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
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	if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
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		cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
}
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/*
 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
 * not dropped, but CAIF is sending flow off instead.
 */
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static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
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{
	int err;
	int skb_len;
	unsigned long flags;
	struct sk_buff_head *list = &sk->sk_receive_queue;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
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	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
		(unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
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		pr_debug("sending flow OFF (queue len = %d %d)\n",
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			atomic_read(&cf_sk->sk.sk_rmem_alloc),
			sk_rcvbuf_lowwater(cf_sk));
		set_rx_flow_off(cf_sk);
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		dbfs_atomic_inc(&cnt.num_rx_flow_off);
		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
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	}
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	err = sk_filter(sk, skb);
	if (err)
		return err;
	if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
		set_rx_flow_off(cf_sk);
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		pr_debug("sending flow OFF due to rmem_schedule\n");
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		dbfs_atomic_inc(&cnt.num_rx_flow_off);
		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
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	}
	skb->dev = NULL;
	skb_set_owner_r(skb, sk);
	/* Cache the SKB length before we tack it onto the receive
	 * queue. Once it is added it no longer belongs to us and
	 * may be freed by other threads of control pulling packets
	 * from the queue.
	 */
	skb_len = skb->len;
	spin_lock_irqsave(&list->lock, flags);
	if (!sock_flag(sk, SOCK_DEAD))
		__skb_queue_tail(list, skb);
	spin_unlock_irqrestore(&list->lock, flags);

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_data_ready(sk, skb_len);
	else
		kfree_skb(skb);
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	return 0;
}

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/* Packet Receive Callback function called from CAIF Stack */
static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
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{
	struct caifsock *cf_sk;
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	struct sk_buff *skb;
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	cf_sk = container_of(layr, struct caifsock, layer);
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	skb = cfpkt_tonative(pkt);

	if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
		cfpkt_destroy(pkt);
		return 0;
	}
	caif_queue_rcv_skb(&cf_sk->sk, skb);
	return 0;
}
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/* Packet Control Callback function called from CAIF */
static void caif_ctrl_cb(struct cflayer *layr,
				enum caif_ctrlcmd flow,
				int phyid)
{
	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
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	switch (flow) {
	case CAIF_CTRLCMD_FLOW_ON_IND:
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		/* OK from modem to start sending again */
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		dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
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		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
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		break;

	case CAIF_CTRLCMD_FLOW_OFF_IND:
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		/* Modem asks us to shut up */
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		dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
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		set_tx_flow_off(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
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		break;

	case CAIF_CTRLCMD_INIT_RSP:
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		/* We're now connected */
		dbfs_atomic_inc(&cnt.num_connect_resp);
		cf_sk->sk.sk_state = CAIF_CONNECTED;
		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
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		break;

	case CAIF_CTRLCMD_DEINIT_RSP:
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		/* We're now disconnected */
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		cf_sk->sk.sk_state_change(&cf_sk->sk);
		cfcnfg_release_adap_layer(&cf_sk->layer);
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		break;

	case CAIF_CTRLCMD_INIT_FAIL_RSP:
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		/* Connect request failed */
		dbfs_atomic_inc(&cnt.num_connect_fail_resp);
		cf_sk->sk.sk_err = ECONNREFUSED;
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
		/*
		 * Socket "standards" seems to require POLLOUT to
		 * be set at connect failure.
		 */
		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
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		break;

	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
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		/* Modem has closed this connection, or device is down. */
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		dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
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		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
		cf_sk->sk.sk_err = ECONNRESET;
		set_rx_flow_on(cf_sk);
		cf_sk->sk.sk_error_report(&cf_sk->sk);
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		break;

	default:
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		pr_debug("Unexpected flow command %d\n", flow);
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	}
}

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static void caif_check_flow_release(struct sock *sk)
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{
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	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
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	if (rx_flow_is_on(cf_sk))
		return;
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	if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
			dbfs_atomic_inc(&cnt.num_rx_flow_on);
			set_rx_flow_on(cf_sk);
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			caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
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	}
}
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/*
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 * Copied from unix_dgram_recvmsg, but removed credit checks,
 * changed locking, address handling and added MSG_TRUNC.
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 */
static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
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				struct msghdr *m, size_t len, int flags)
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{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
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	int ret;
	int copylen;
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	ret = -EOPNOTSUPP;
	if (m->msg_flags&MSG_OOB)
		goto read_error;
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	skb = skb_recv_datagram(sk, flags, 0 , &ret);
	if (!skb)
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		goto read_error;
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	copylen = skb->len;
	if (len < copylen) {
		m->msg_flags |= MSG_TRUNC;
		copylen = len;
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	}

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	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
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	if (ret)
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		goto out_free;
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	ret = (flags & MSG_TRUNC) ? skb->len : copylen;
out_free:
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	skb_free_datagram(sk, skb);
	caif_check_flow_release(sk);
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	return ret;
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read_error:
	return ret;
}
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/* Copied from unix_stream_wait_data, identical except for lock call. */
static long caif_stream_data_wait(struct sock *sk, long timeo)
{
	DEFINE_WAIT(wait);
	lock_sock(sk);

	for (;;) {
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

		if (!skb_queue_empty(&sk->sk_receive_queue) ||
			sk->sk_err ||
			sk->sk_state != CAIF_CONNECTED ||
			sock_flag(sk, SOCK_DEAD) ||
			(sk->sk_shutdown & RCV_SHUTDOWN) ||
			signal_pending(current) ||
			!timeo)
			break;
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		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock(sk);
		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
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	}

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	finish_wait(sk_sleep(sk), &wait);
	release_sock(sk);
	return timeo;
}
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/*
 * Copied from unix_stream_recvmsg, but removed credit checks,
 * changed locking calls, changed address handling.
 */
static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
				struct msghdr *msg, size_t size,
				int flags)
{
	struct sock *sk = sock->sk;
	int copied = 0;
	int target;
	int err = 0;
	long timeo;
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	err = -EOPNOTSUPP;
	if (flags&MSG_OOB)
		goto out;
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	msg->msg_namelen = 0;
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	/*
	 * Lock the socket to prevent queue disordering
	 * while sleeps in memcpy_tomsg
	 */
	err = -EAGAIN;
	if (sk->sk_state == CAIF_CONNECTING)
		goto out;
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	caif_read_lock(sk);
	target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
	timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
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	do {
		int chunk;
		struct sk_buff *skb;
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		lock_sock(sk);
		skb = skb_dequeue(&sk->sk_receive_queue);
		caif_check_flow_release(sk);
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		if (skb == NULL) {
			if (copied >= target)
				goto unlock;
			/*
			 *	POSIX 1003.1g mandates this order.
			 */
			err = sock_error(sk);
			if (err)
				goto unlock;
			err = -ECONNRESET;
			if (sk->sk_shutdown & RCV_SHUTDOWN)
				goto unlock;
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			err = -EPIPE;
			if (sk->sk_state != CAIF_CONNECTED)
				goto unlock;
			if (sock_flag(sk, SOCK_DEAD))
				goto unlock;
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			release_sock(sk);
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			err = -EAGAIN;
			if (!timeo)
				break;
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			caif_read_unlock(sk);
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			timeo = caif_stream_data_wait(sk, timeo);
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			if (signal_pending(current)) {
				err = sock_intr_errno(timeo);
				goto out;
			}
			caif_read_lock(sk);
			continue;
unlock:
			release_sock(sk);
			break;
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		}
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		release_sock(sk);
		chunk = min_t(unsigned int, skb->len, size);
		if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
			skb_queue_head(&sk->sk_receive_queue, skb);
			if (copied == 0)
				copied = -EFAULT;
			break;
		}
		copied += chunk;
		size -= chunk;
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		/* Mark read part of skb as used */
		if (!(flags & MSG_PEEK)) {
			skb_pull(skb, chunk);
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			/* put the skb back if we didn't use it up. */
			if (skb->len) {
				skb_queue_head(&sk->sk_receive_queue, skb);
				break;
			}
			kfree_skb(skb);
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		} else {
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			/*
			 * It is questionable, see note in unix_dgram_recvmsg.
			 */
			/* put message back and return */
			skb_queue_head(&sk->sk_receive_queue, skb);
			break;
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		}
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	} while (size);
	caif_read_unlock(sk);
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out:
	return copied ? : err;
}
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/*
 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
 * CAIF flow-on and sock_writable.
 */
static long caif_wait_for_flow_on(struct caifsock *cf_sk,
				int wait_writeable, long timeo, int *err)
{
	struct sock *sk = &cf_sk->sk;
	DEFINE_WAIT(wait);
	for (;;) {
		*err = 0;
		if (tx_flow_is_on(cf_sk) &&
			(!wait_writeable || sock_writeable(&cf_sk->sk)))
			break;
		*err = -ETIMEDOUT;
		if (!timeo)
			break;
		*err = -ERESTARTSYS;
		if (signal_pending(current))
			break;
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
		*err = -ECONNRESET;
		if (sk->sk_shutdown & SHUTDOWN_MASK)
			break;
		*err = -sk->sk_err;
		if (sk->sk_err)
			break;
		*err = -EPIPE;
		if (cf_sk->sk.sk_state != CAIF_CONNECTED)
			break;
		timeo = schedule_timeout(timeo);
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	}
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	finish_wait(sk_sleep(sk), &wait);
	return timeo;
}
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/*
 * Transmit a SKB. The device may temporarily request re-transmission
 * by returning EAGAIN.
 */
static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
			int noblock, long timeo)
{
	struct cfpkt *pkt;
	int ret, loopcnt = 0;
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	pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
	memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
	do {
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		ret = -ETIMEDOUT;
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		/* Slight paranoia, probably not needed. */
		if (unlikely(loopcnt++ > 1000)) {
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			pr_warn("transmit retries failed, error = %d\n", ret);
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			break;
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		}

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		if (cf_sk->layer.dn != NULL)
			ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
		if (likely(ret >= 0))
			break;
		/* if transmit return -EAGAIN, then retry */
		if (noblock && ret == -EAGAIN)
			break;
		timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
		if (signal_pending(current)) {
			ret = sock_intr_errno(timeo);
			break;
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		}
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		if (ret)
			break;
		if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
			sock_flag(&cf_sk->sk, SOCK_DEAD) ||
			(cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
			ret = -EPIPE;
			cf_sk->sk.sk_err = EPIPE;
			break;
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		}
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	} while (ret == -EAGAIN);
	return ret;
}
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/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int buffer_size;
	int ret = 0;
	struct sk_buff *skb = NULL;
	int noblock;
	long timeo;
	caif_assert(cf_sk);
	ret = sock_error(sk);
	if (ret)
		goto err;

	ret = -EOPNOTSUPP;
	if (msg->msg_flags&MSG_OOB)
		goto err;

	ret = -EOPNOTSUPP;
	if (msg->msg_namelen)
		goto err;

	ret = -EINVAL;
	if (unlikely(msg->msg_iov->iov_base == NULL))
		goto err;
	noblock = msg->msg_flags & MSG_DONTWAIT;

	timeo = sock_sndtimeo(sk, noblock);
	timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
				1, timeo, &ret);

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	if (ret)
		goto err;
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	ret = -EPIPE;
	if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
		sock_flag(sk, SOCK_DEAD) ||
		(sk->sk_shutdown & RCV_SHUTDOWN))
		goto err;

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	/* Error if trying to write more than maximum frame size. */
	ret = -EMSGSIZE;
	if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
		goto err;

	buffer_size = len + cf_sk->headroom + cf_sk->tailroom;

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	ret = -ENOMEM;
	skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
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	if (!skb || skb_tailroom(skb) < buffer_size)
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		goto err;
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	skb_reserve(skb, cf_sk->headroom);
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	ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);

	if (ret)
		goto err;
	ret = transmit_skb(skb, cf_sk, noblock, timeo);
	if (ret < 0)
		goto err;
	return len;
err:
	kfree_skb(skb);
	return ret;
}
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/*
 * Copied from unix_stream_sendmsg and adapted to CAIF:
 * Changed removed permission handling and added waiting for flow on
 * and other minor adaptations.
 */
static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
				struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int err, size;
	struct sk_buff *skb;
	int sent = 0;
	long timeo;
644

645 646 647
	err = -EOPNOTSUPP;
	if (unlikely(msg->msg_flags&MSG_OOB))
		goto out_err;
648

649 650
	if (unlikely(msg->msg_namelen))
		goto out_err;
651

652 653
	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
	timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
654

655 656
	if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
		goto pipe_err;
657

658
	while (sent < len) {
659

660
		size = len-sent;
661

662 663
		if (size > cf_sk->maxframe)
			size = cf_sk->maxframe;
664

665 666 667
		/* If size is more than half of sndbuf, chop up message */
		if (size > ((sk->sk_sndbuf >> 1) - 64))
			size = (sk->sk_sndbuf >> 1) - 64;
668

669 670
		if (size > SKB_MAX_ALLOC)
			size = SKB_MAX_ALLOC;
671

672
		skb = sock_alloc_send_skb(sk,
673 674
					size + cf_sk->headroom +
					cf_sk->tailroom,
675 676 677 678
					msg->msg_flags&MSG_DONTWAIT,
					&err);
		if (skb == NULL)
			goto out_err;
679

680
		skb_reserve(skb, cf_sk->headroom);
681 682 683 684 685 686 687 688
		/*
		 *	If you pass two values to the sock_alloc_send_skb
		 *	it tries to grab the large buffer with GFP_NOFS
		 *	(which can fail easily), and if it fails grab the
		 *	fallback size buffer which is under a page and will
		 *	succeed. [Alan]
		 */
		size = min_t(int, size, skb_tailroom(skb));
689

690 691 692 693 694 695 696 697 698 699 700 701
		err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
		if (err) {
			kfree_skb(skb);
			goto out_err;
		}
		err = transmit_skb(skb, cf_sk,
				msg->msg_flags&MSG_DONTWAIT, timeo);
		if (err < 0) {
			kfree_skb(skb);
			goto pipe_err;
		}
		sent += size;
702 703
	}

704
	return sent;
705

706 707 708 709 710 711
pipe_err:
	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
		send_sig(SIGPIPE, current, 0);
	err = -EPIPE;
out_err:
	return sent ? : err;
712 713 714 715 716 717 718
}

static int setsockopt(struct socket *sock,
			int lvl, int opt, char __user *ov, unsigned int ol)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
719
	int linksel;
720

721
	if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
722
		return -ENOPROTOOPT;
723

724 725
	switch (opt) {
	case CAIFSO_LINK_SELECT:
726
		if (ol < sizeof(int))
727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
			return -EINVAL;
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (copy_from_user(&linksel, ov, sizeof(int)))
			return -EINVAL;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.link_selector = linksel;
		release_sock(&cf_sk->sk);
		return 0;

	case CAIFSO_REQ_PARAM:
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
			return -ENOPROTOOPT;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.param.size = ol;
744 745
		if (ol > sizeof(cf_sk->conn_req.param.data) ||
			copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
746 747 748 749 750 751 752
			release_sock(&cf_sk->sk);
			return -EINVAL;
		}
		release_sock(&cf_sk->sk);
		return 0;

	default:
753
		return -ENOPROTOOPT;
754 755 756 757 758 759 760 761
	}

	return 0;
bad_sol:
	return -ENOPROTOOPT;

}

762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787
/*
 * caif_connect() - Connect a CAIF Socket
 * Copied and modified af_irda.c:irda_connect().
 *
 * Note : by consulting "errno", the user space caller may learn the cause
 * of the failure. Most of them are visible in the function, others may come
 * from subroutines called and are listed here :
 *  o -EAFNOSUPPORT: bad socket family or type.
 *  o -ESOCKTNOSUPPORT: bad socket type or protocol
 *  o -EINVAL: bad socket address, or CAIF link type
 *  o -ECONNREFUSED: remote end refused the connection.
 *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
 *  o -EISCONN: already connected.
 *  o -ETIMEDOUT: Connection timed out (send timeout)
 *  o -ENODEV: No link layer to send request
 *  o -ECONNRESET: Received Shutdown indication or lost link layer
 *  o -ENOMEM: Out of memory
 *
 *  State Strategy:
 *  o sk_state: holds the CAIF_* protocol state, it's updated by
 *	caif_ctrl_cb.
 *  o sock->state: holds the SS_* socket state and is updated by connect and
 *	disconnect.
 */
static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
			int addr_len, int flags)
788 789
{
	struct sock *sk = sock->sk;
790 791 792
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	long timeo;
	int err;
793
	int ifindex, headroom, tailroom;
E
Eric Dumazet 已提交
794
	unsigned int mtu;
795 796
	struct net_device *dev;

797
	lock_sock(sk);
798

799 800
	err = -EAFNOSUPPORT;
	if (uaddr->sa_family != AF_CAIF)
801 802
		goto out;

803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
	switch (sock->state) {
	case SS_UNCONNECTED:
		/* Normal case, a fresh connect */
		caif_assert(sk->sk_state == CAIF_DISCONNECTED);
		break;
	case SS_CONNECTING:
		switch (sk->sk_state) {
		case CAIF_CONNECTED:
			sock->state = SS_CONNECTED;
			err = -EISCONN;
			goto out;
		case CAIF_DISCONNECTED:
			/* Reconnect allowed */
			break;
		case CAIF_CONNECTING:
			err = -EALREADY;
			if (flags & O_NONBLOCK)
				goto out;
			goto wait_connect;
		}
		break;
	case SS_CONNECTED:
		caif_assert(sk->sk_state == CAIF_CONNECTED ||
				sk->sk_state == CAIF_DISCONNECTED);
		if (sk->sk_shutdown & SHUTDOWN_MASK) {
			/* Allow re-connect after SHUTDOWN_IND */
			caif_disconnect_client(&cf_sk->layer);
			break;
		}
		/* No reconnect on a seqpacket socket */
		err = -EISCONN;
		goto out;
	case SS_DISCONNECTING:
	case SS_FREE:
		caif_assert(1); /*Should never happen */
		break;
839
	}
840 841 842
	sk->sk_state = CAIF_DISCONNECTED;
	sock->state = SS_UNCONNECTED;
	sk_stream_kill_queues(&cf_sk->sk);
843

844
	err = -EINVAL;
845
	if (addr_len != sizeof(struct sockaddr_caif))
846
		goto out;
847

848
	memcpy(&cf_sk->conn_req.sockaddr, uaddr,
849 850
		sizeof(struct sockaddr_caif));

851 852 853 854
	/* Move to connecting socket, start sending Connect Requests */
	sock->state = SS_CONNECTING;
	sk->sk_state = CAIF_CONNECTING;

855 856 857 858 859 860 861 862 863 864 865 866
	/* Check priority value comming from socket */
	/* if priority value is out of range it will be ajusted */
	if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
		cf_sk->conn_req.priority = CAIF_PRIO_MAX;
	else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
		cf_sk->conn_req.priority = CAIF_PRIO_MIN;
	else
		cf_sk->conn_req.priority = cf_sk->sk.sk_priority;

	/*ifindex = id of the interface.*/
	cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;

867 868 869
	dbfs_atomic_inc(&cnt.num_connect_req);
	cf_sk->layer.receive = caif_sktrecv_cb;
	err = caif_connect_client(&cf_sk->conn_req,
870
				&cf_sk->layer, &ifindex, &headroom, &tailroom);
871 872 873 874
	if (err < 0) {
		cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		goto out;
875
	}
E
Eric Dumazet 已提交
876 877 878 879 880 881 882 883

	err = -ENODEV;
	rcu_read_lock();
	dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
	if (!dev) {
		rcu_read_unlock();
		goto out;
	}
884
	cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
E
Eric Dumazet 已提交
885 886 887
	mtu = dev->mtu;
	rcu_read_unlock();

888
	cf_sk->tailroom = tailroom;
E
Eric Dumazet 已提交
889
	cf_sk->maxframe = mtu - (headroom + tailroom);
890
	if (cf_sk->maxframe < 1) {
J
Joe Perches 已提交
891
		pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
892
		err = -ENODEV;
893 894
		goto out;
	}
895

896 897
	err = -EINPROGRESS;
wait_connect:
898

899 900
	if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
		goto out;
901

902 903 904
	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);

	release_sock(sk);
905 906
	err = -ERESTARTSYS;
	timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
907 908 909
			sk->sk_state != CAIF_CONNECTING,
			timeo);
	lock_sock(sk);
910
	if (timeo < 0)
911
		goto out; /* -ERESTARTSYS */
912

913 914 915
	err = -ETIMEDOUT;
	if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
		goto out;
916 917 918 919 920 921 922 923 924
	if (sk->sk_state != CAIF_CONNECTED) {
		sock->state = SS_UNCONNECTED;
		err = sock_error(sk);
		if (!err)
			err = -ECONNREFUSED;
		goto out;
	}
	sock->state = SS_CONNECTED;
	err = 0;
925
out:
926 927
	release_sock(sk);
	return err;
928 929
}

930 931 932 933 934
/*
 * caif_release() - Disconnect a CAIF Socket
 * Copied and modified af_irda.c:irda_release().
 */
static int caif_release(struct socket *sock)
935 936
{
	struct sock *sk = sock->sk;
937 938
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int res = 0;
939

940 941
	if (!sk)
		return 0;
942

943
	set_tx_flow_off(cf_sk);
944 945

	/*
946 947 948
	 * Ensure that packets are not queued after this point in time.
	 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
	 * this ensures no packets when sock is dead.
949
	 */
950 951 952 953
	spin_lock(&sk->sk_receive_queue.lock);
	sock_set_flag(sk, SOCK_DEAD);
	spin_unlock(&sk->sk_receive_queue.lock);
	sock->sk = NULL;
954

955
	dbfs_atomic_inc(&cnt.num_disconnect);
956 957 958 959 960

	if (cf_sk->debugfs_socket_dir != NULL)
		debugfs_remove_recursive(cf_sk->debugfs_socket_dir);

	lock_sock(&(cf_sk->sk));
961 962
	sk->sk_state = CAIF_DISCONNECTED;
	sk->sk_shutdown = SHUTDOWN_MASK;
963

964 965 966
	if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
		cf_sk->sk.sk_socket->state == SS_CONNECTING)
		res = caif_disconnect_client(&cf_sk->layer);
967

968 969
	cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
	wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
970

971 972 973 974 975 976 977
	sock_orphan(sk);
	cf_sk->layer.dn = NULL;
	sk_stream_kill_queues(&cf_sk->sk);
	release_sock(sk);
	sock_put(sk);
	return res;
}
978

979 980 981 982 983 984 985
/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
static unsigned int caif_poll(struct file *file,
				struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
986

987 988
	sock_poll_wait(file, sk_sleep(sk), wait);
	mask = 0;
989

990 991 992 993 994 995 996
	/* exceptional events? */
	if (sk->sk_err)
		mask |= POLLERR;
	if (sk->sk_shutdown == SHUTDOWN_MASK)
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLRDHUP;
997

998 999 1000 1001
	/* readable? */
	if (!skb_queue_empty(&sk->sk_receive_queue) ||
		(sk->sk_shutdown & RCV_SHUTDOWN))
		mask |= POLLIN | POLLRDNORM;
1002 1003

	/*
1004 1005
	 * we set writable also when the other side has shut down the
	 * connection. This prevents stuck sockets.
1006
	 */
1007 1008 1009 1010
	if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

	return mask;
1011 1012
}

1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034
static const struct proto_ops caif_seqpacket_ops = {
	.family = PF_CAIF,
	.owner = THIS_MODULE,
	.release = caif_release,
	.bind = sock_no_bind,
	.connect = caif_connect,
	.socketpair = sock_no_socketpair,
	.accept = sock_no_accept,
	.getname = sock_no_getname,
	.poll = caif_poll,
	.ioctl = sock_no_ioctl,
	.listen = sock_no_listen,
	.shutdown = sock_no_shutdown,
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
	.sendmsg = caif_seqpkt_sendmsg,
	.recvmsg = caif_seqpkt_recvmsg,
	.mmap = sock_no_mmap,
	.sendpage = sock_no_sendpage,
};

static const struct proto_ops caif_stream_ops = {
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
	.family = PF_CAIF,
	.owner = THIS_MODULE,
	.release = caif_release,
	.bind = sock_no_bind,
	.connect = caif_connect,
	.socketpair = sock_no_socketpair,
	.accept = sock_no_accept,
	.getname = sock_no_getname,
	.poll = caif_poll,
	.ioctl = sock_no_ioctl,
	.listen = sock_no_listen,
1046
	.shutdown = sock_no_shutdown,
1047 1048
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
1049 1050
	.sendmsg = caif_stream_sendmsg,
	.recvmsg = caif_stream_recvmsg,
1051
	.mmap = sock_no_mmap,
1052
	.sendpage = sock_no_sendpage,
1053 1054 1055 1056 1057
};

/* This function is called when a socket is finally destroyed. */
static void caif_sock_destructor(struct sock *sk)
{
1058
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1059 1060 1061 1062
	caif_assert(!atomic_read(&sk->sk_wmem_alloc));
	caif_assert(sk_unhashed(sk));
	caif_assert(!sk->sk_socket);
	if (!sock_flag(sk, SOCK_DEAD)) {
1063
		pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1064 1065
		return;
	}
1066 1067
	sk_stream_kill_queues(&cf_sk->sk);
	dbfs_atomic_dec(&cnt.caif_nr_socks);
1068 1069 1070
}

static int caif_create(struct net *net, struct socket *sock, int protocol,
1071
			int kern)
1072 1073 1074 1075 1076 1077 1078 1079
{
	struct sock *sk = NULL;
	struct caifsock *cf_sk = NULL;
	static struct proto prot = {.name = "PF_CAIF",
		.owner = THIS_MODULE,
		.obj_size = sizeof(struct caifsock),
	};

1080 1081
	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
		return -EPERM;
1082 1083
	/*
	 * The sock->type specifies the socket type to use.
1084 1085 1086
	 * The CAIF socket is a packet stream in the sense
	 * that it is packet based. CAIF trusts the reliability
	 * of the link, no resending is implemented.
1087
	 */
1088 1089 1090 1091 1092
	if (sock->type == SOCK_SEQPACKET)
		sock->ops = &caif_seqpacket_ops;
	else if (sock->type == SOCK_STREAM)
		sock->ops = &caif_stream_ops;
	else
1093 1094 1095 1096 1097
		return -ESOCKTNOSUPPORT;

	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
		return -EPROTONOSUPPORT;
	/*
1098 1099
	 * Set the socket state to unconnected.	 The socket state
	 * is really not used at all in the net/core or socket.c but the
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
	 * initialization makes sure that sock->state is not uninitialized.
	 */
	sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
	if (!sk)
		return -ENOMEM;

	cf_sk = container_of(sk, struct caifsock, sk);

	/* Store the protocol */
	sk->sk_protocol = (unsigned char) protocol;

	/*
	 * Lock in order to try to stop someone from opening the socket
	 * too early.
	 */
	lock_sock(&(cf_sk->sk));

	/* Initialize the nozero default sock structure data. */
	sock_init_data(sock, sk);
	sk->sk_destruct = caif_sock_destructor;

1121 1122 1123 1124
	mutex_init(&cf_sk->readlock); /* single task reading lock */
	cf_sk->layer.ctrlcmd = caif_ctrl_cb;
	cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
	cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1125

1126 1127
	set_tx_flow_off(cf_sk);
	set_rx_flow_on(cf_sk);
1128 1129

	/* Set default options on configuration */
1130
	cf_sk->sk.sk_priority= CAIF_PRIO_NORMAL;
1131
	cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1132 1133
	cf_sk->conn_req.protocol = protocol;
	/* Increase the number of sockets created. */
1134 1135
	dbfs_atomic_inc(&cnt.caif_nr_socks);
#ifdef CONFIG_DEBUG_FS
1136
	if (!IS_ERR(debugfsdir)) {
1137 1138 1139 1140
		/* Fill in some information concerning the misc socket. */
		snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
				atomic_read(&cnt.caif_nr_socks));

1141 1142
		cf_sk->debugfs_socket_dir =
			debugfs_create_dir(cf_sk->name, debugfsdir);
1143 1144 1145
		debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->sk.sk_state);
1146 1147
		debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1148 1149 1150 1151
		debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->sk.sk_rmem_alloc);
		debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1152
				cf_sk->debugfs_socket_dir,
1153
				(u32 *) &cf_sk->sk.sk_wmem_alloc);
1154 1155 1156 1157
		debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->layer.id);
	}
1158
#endif
1159 1160 1161 1162
	release_sock(&cf_sk->sk);
	return 0;
}

1163

1164 1165 1166 1167 1168 1169
static struct net_proto_family caif_family_ops = {
	.family = PF_CAIF,
	.create = caif_create,
	.owner = THIS_MODULE,
};

1170
static int af_caif_init(void)
1171
{
1172
	int err = sock_register(&caif_family_ops);
1173 1174 1175 1176 1177 1178 1179 1180
	if (!err)
		return err;
	return 0;
}

static int __init caif_sktinit_module(void)
{
#ifdef CONFIG_DEBUG_FS
1181
	debugfsdir = debugfs_create_dir("caif_sk", NULL);
1182 1183 1184
	if (!IS_ERR(debugfsdir)) {
		debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
				debugfsdir,
1185 1186
				(u32 *) &cnt.caif_nr_socks);
		debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1187
				debugfsdir,
1188 1189
				(u32 *) &cnt.num_connect_req);
		debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1190
				debugfsdir,
1191 1192
				(u32 *) &cnt.num_connect_resp);
		debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1193
				debugfsdir,
1194 1195
				(u32 *) &cnt.num_connect_fail_resp);
		debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1196
				debugfsdir,
1197
				(u32 *) &cnt.num_disconnect);
1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
		debugfs_create_u32("num_remote_shutdown_ind",
				S_IRUSR | S_IWUSR, debugfsdir,
				(u32 *) &cnt.num_remote_shutdown_ind);
		debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_off_ind);
		debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_on_ind);
		debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_off);
		debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_on);
	}
#endif
1215
	return af_caif_init();
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
}

static void __exit caif_sktexit_module(void)
{
	sock_unregister(PF_CAIF);
	if (debugfsdir != NULL)
		debugfs_remove_recursive(debugfsdir);
}
module_init(caif_sktinit_module);
module_exit(caif_sktexit_module);