caif_socket.c 30 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
 */

#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/mutex.h>
#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);

#define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10)
#define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100)

/*
 * 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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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)) {
		trace_printk("CAIF: %s():"
			" sending flow OFF (queue len = %d %d)\n",
			__func__,
			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);
		trace_printk("CAIF: %s():"
			" sending flow OFF due to rmem_schedule\n",
			__func__);
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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:
		pr_debug("CAIF: %s(): Unexpected flow command %d\n",
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				__func__, 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)) {
			pr_warning("CAIF: %s(): transmit retries failed,"
				" error = %d\n", __func__, ret);
			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;

	buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM;

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

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

	ret = -ENOMEM;
	skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
	if (!skb)
		goto err;
	skb_reserve(skb, CAIF_NEEDED_HEADROOM);

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

648 649
	if (unlikely(msg->msg_namelen))
		goto out_err;
650

651 652
	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
	timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
653

654 655
	if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
		goto pipe_err;
656

657
	while (sent < len) {
658

659
		size = len-sent;
660

661 662
		if (size > CAIF_MAX_PAYLOAD_SIZE)
			size = CAIF_MAX_PAYLOAD_SIZE;
663

664 665 666
		/* If size is more than half of sndbuf, chop up message */
		if (size > ((sk->sk_sndbuf >> 1) - 64))
			size = (sk->sk_sndbuf >> 1) - 64;
667

668 669
		if (size > SKB_MAX_ALLOC)
			size = SKB_MAX_ALLOC;
670

671 672 673 674 675 676 677
		skb = sock_alloc_send_skb(sk,
					size + CAIF_NEEDED_HEADROOM
					+ CAIF_NEEDED_TAILROOM,
					msg->msg_flags&MSG_DONTWAIT,
					&err);
		if (skb == NULL)
			goto out_err;
678

679 680 681 682 683 684 685 686 687
		skb_reserve(skb, CAIF_NEEDED_HEADROOM);
		/*
		 *	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));
688

689 690 691 692 693 694 695 696 697 698 699 700
		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;
701 702
	}

703
	return sent;
704

705 706 707 708 709 710
pipe_err:
	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
		send_sig(SIGPIPE, current, 0);
	err = -EPIPE;
out_err:
	return sent ? : err;
711 712 713 714 715 716 717 718 719 720
}

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);
	int prio, linksel;
	struct ifreq ifreq;

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
			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 SO_PRIORITY:
		if (lvl != SOL_SOCKET)
			goto bad_sol;
740
		if (ol < sizeof(int))
741 742 743 744 745 746 747 748 749 750 751
			return -EINVAL;
		if (copy_from_user(&prio, ov, sizeof(int)))
			return -EINVAL;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.priority = prio;
		release_sock(&cf_sk->sk);
		return 0;

	case SO_BINDTODEVICE:
		if (lvl != SOL_SOCKET)
			goto bad_sol;
752
		if (ol < sizeof(struct ifreq))
753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770
			return -EINVAL;
		if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
			return -EFAULT;
		lock_sock(&(cf_sk->sk));
		strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
			sizeof(cf_sk->conn_req.link_name));
		cf_sk->conn_req.link_name
			[sizeof(cf_sk->conn_req.link_name)-1] = 0;
		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;
771 772
		if (ol > sizeof(cf_sk->conn_req.param.data) ||
			copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
773 774 775 776 777 778 779
			release_sock(&cf_sk->sk);
			return -EINVAL;
		}
		release_sock(&cf_sk->sk);
		return 0;

	default:
780
		return -ENOPROTOOPT;
781 782 783 784 785 786 787 788
	}

	return 0;
bad_sol:
	return -ENOPROTOOPT;

}

789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814
/*
 * 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)
815 816
{
	struct sock *sk = sock->sk;
817 818 819 820
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	long timeo;
	int err;
	lock_sock(sk);
821

822 823
	err = -EAFNOSUPPORT;
	if (uaddr->sa_family != AF_CAIF)
824 825
		goto out;

826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866
	err = -ESOCKTNOSUPPORT;
	if (unlikely(!(sk->sk_type == SOCK_STREAM &&
		       cf_sk->sk.sk_protocol == CAIFPROTO_AT) &&
		       sk->sk_type != SOCK_SEQPACKET))
		goto out;
	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;
867
	}
868 869 870
	sk->sk_state = CAIF_DISCONNECTED;
	sock->state = SS_UNCONNECTED;
	sk_stream_kill_queues(&cf_sk->sk);
871

872
	err = -EINVAL;
873
	if (addr_len != sizeof(struct sockaddr_caif))
874
		goto out;
875

876
	memcpy(&cf_sk->conn_req.sockaddr, uaddr,
877 878
		sizeof(struct sockaddr_caif));

879 880 881 882 883 884 885 886 887 888 889 890
	/* Move to connecting socket, start sending Connect Requests */
	sock->state = SS_CONNECTING;
	sk->sk_state = CAIF_CONNECTING;

	dbfs_atomic_inc(&cnt.num_connect_req);
	cf_sk->layer.receive = caif_sktrecv_cb;
	err = caif_connect_client(&cf_sk->conn_req,
				&cf_sk->layer);
	if (err < 0) {
		cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		goto out;
891 892
	}

893 894
	err = -EINPROGRESS;
wait_connect:
895

896 897
	if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
		goto out;
898

899 900 901
	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);

	release_sock(sk);
902 903
	err = -ERESTARTSYS;
	timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
904 905 906
			sk->sk_state != CAIF_CONNECTING,
			timeo);
	lock_sock(sk);
907
	if (timeo < 0)
908
		goto out; /* -ERESTARTSYS */
909

910 911 912
	err = -ETIMEDOUT;
	if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
		goto out;
913 914 915 916 917 918 919 920 921
	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;
922
out:
923 924
	release_sock(sk);
	return err;
925 926
}

927 928 929 930 931
/*
 * caif_release() - Disconnect a CAIF Socket
 * Copied and modified af_irda.c:irda_release().
 */
static int caif_release(struct socket *sock)
932 933
{
	struct sock *sk = sock->sk;
934 935
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int res = 0;
936

937 938
	if (!sk)
		return 0;
939

940
	set_tx_flow_off(cf_sk);
941 942

	/*
943 944 945
	 * 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.
946
	 */
947 948 949 950
	spin_lock(&sk->sk_receive_queue.lock);
	sock_set_flag(sk, SOCK_DEAD);
	spin_unlock(&sk->sk_receive_queue.lock);
	sock->sk = NULL;
951

952
	dbfs_atomic_inc(&cnt.num_disconnect);
953 954 955 956 957

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

	lock_sock(&(cf_sk->sk));
958 959
	sk->sk_state = CAIF_DISCONNECTED;
	sk->sk_shutdown = SHUTDOWN_MASK;
960

961 962 963
	if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
		cf_sk->sk.sk_socket->state == SS_CONNECTING)
		res = caif_disconnect_client(&cf_sk->layer);
964

965 966
	cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
	wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
967

968 969 970 971 972 973 974
	sock_orphan(sk);
	cf_sk->layer.dn = NULL;
	sk_stream_kill_queues(&cf_sk->sk);
	release_sock(sk);
	sock_put(sk);
	return res;
}
975

976 977 978 979 980 981 982
/* 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);
983

984 985
	sock_poll_wait(file, sk_sleep(sk), wait);
	mask = 0;
986

987 988 989 990 991 992 993
	/* exceptional events? */
	if (sk->sk_err)
		mask |= POLLERR;
	if (sk->sk_shutdown == SHUTDOWN_MASK)
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLRDHUP;
994

995 996 997 998
	/* readable? */
	if (!skb_queue_empty(&sk->sk_receive_queue) ||
		(sk->sk_shutdown & RCV_SHUTDOWN))
		mask |= POLLIN | POLLRDNORM;
999 1000

	/*
1001 1002
	 * we set writable also when the other side has shut down the
	 * connection. This prevents stuck sockets.
1003
	 */
1004 1005 1006 1007
	if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

	return mask;
1008 1009
}

1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
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 = {
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
	.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,
1043
	.shutdown = sock_no_shutdown,
1044 1045
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
1046 1047
	.sendmsg = caif_stream_sendmsg,
	.recvmsg = caif_stream_recvmsg,
1048
	.mmap = sock_no_mmap,
1049
	.sendpage = sock_no_sendpage,
1050 1051 1052 1053 1054
};

/* This function is called when a socket is finally destroyed. */
static void caif_sock_destructor(struct sock *sk)
{
1055
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1056 1057 1058 1059
	caif_assert(!atomic_read(&sk->sk_wmem_alloc));
	caif_assert(sk_unhashed(sk));
	caif_assert(!sk->sk_socket);
	if (!sock_flag(sk, SOCK_DEAD)) {
1060
		pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1061 1062
		return;
	}
1063 1064
	sk_stream_kill_queues(&cf_sk->sk);
	dbfs_atomic_dec(&cnt.caif_nr_socks);
1065 1066 1067
}

static int caif_create(struct net *net, struct socket *sock, int protocol,
1068
			int kern)
1069 1070 1071 1072 1073 1074 1075 1076
{
	struct sock *sk = NULL;
	struct caifsock *cf_sk = NULL;
	static struct proto prot = {.name = "PF_CAIF",
		.owner = THIS_MODULE,
		.obj_size = sizeof(struct caifsock),
	};

1077 1078
	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
		return -EPERM;
1079 1080
	/*
	 * The sock->type specifies the socket type to use.
1081 1082 1083
	 * 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.
1084
	 */
1085 1086 1087 1088 1089
	if (sock->type == SOCK_SEQPACKET)
		sock->ops = &caif_seqpacket_ops;
	else if (sock->type == SOCK_STREAM)
		sock->ops = &caif_stream_ops;
	else
1090 1091 1092 1093 1094
		return -ESOCKTNOSUPPORT;

	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
		return -EPROTONOSUPPORT;
	/*
1095 1096
	 * Set the socket state to unconnected.	 The socket state
	 * is really not used at all in the net/core or socket.c but the
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
	 * 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;

1108 1109 1110
	/* Sendbuf dictates the amount of outbound packets not yet sent */
	sk->sk_sndbuf = CAIF_DEF_SNDBUF;
	sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121

	/*
	 * 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;

1122 1123 1124 1125
	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;
1126

1127 1128
	set_tx_flow_off(cf_sk);
	set_rx_flow_on(cf_sk);
1129 1130 1131

	/* Set default options on configuration */
	cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1132
	cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1133 1134
	cf_sk->conn_req.protocol = protocol;
	/* Increase the number of sockets created. */
1135 1136
	dbfs_atomic_inc(&cnt.caif_nr_socks);
#ifdef CONFIG_DEBUG_FS
1137
	if (!IS_ERR(debugfsdir)) {
1138 1139 1140 1141
		/* Fill in some information concerning the misc socket. */
		snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
				atomic_read(&cnt.caif_nr_socks));

1142 1143
		cf_sk->debugfs_socket_dir =
			debugfs_create_dir(cf_sk->name, debugfsdir);
1144 1145 1146
		debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->sk.sk_state);
1147 1148
		debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1149 1150 1151 1152
		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,
1153
				cf_sk->debugfs_socket_dir,
1154
				(u32 *) &cf_sk->sk.sk_wmem_alloc);
1155 1156 1157 1158
		debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->layer.id);
	}
1159
#endif
1160 1161 1162 1163
	release_sock(&cf_sk->sk);
	return 0;
}

1164

1165 1166 1167 1168 1169 1170
static struct net_proto_family caif_family_ops = {
	.family = PF_CAIF,
	.create = caif_create,
	.owner = THIS_MODULE,
};

1171
static int af_caif_init(void)
1172
{
1173
	int err = sock_register(&caif_family_ops);
1174 1175 1176 1177 1178 1179 1180 1181
	if (!err)
		return err;
	return 0;
}

static int __init caif_sktinit_module(void)
{
#ifdef CONFIG_DEBUG_FS
1182
	debugfsdir = debugfs_create_dir("caif_sk", NULL);
1183 1184 1185
	if (!IS_ERR(debugfsdir)) {
		debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
				debugfsdir,
1186 1187
				(u32 *) &cnt.caif_nr_socks);
		debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1188
				debugfsdir,
1189 1190
				(u32 *) &cnt.num_connect_req);
		debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1191
				debugfsdir,
1192 1193
				(u32 *) &cnt.num_connect_resp);
		debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1194
				debugfsdir,
1195 1196
				(u32 *) &cnt.num_connect_fail_resp);
		debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1197
				debugfsdir,
1198
				(u32 *) &cnt.num_disconnect);
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
		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
1216
	return af_caif_init();
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
}

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);