예제 #1
1
static int balloon(void *_vballoon)
{
	struct virtio_balloon *vb = _vballoon;
	DEFINE_WAIT_FUNC(wait, woken_wake_function);

	set_freezable();
	while (!kthread_should_stop()) {
		s64 diff;

		try_to_freeze();

		add_wait_queue(&vb->config_change, &wait);
		for (;;) {
			if ((diff = towards_target(vb)) != 0 ||
			    vb->need_stats_update ||
			    kthread_should_stop() ||
			    freezing(current))
				break;
			wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
		}
		remove_wait_queue(&vb->config_change, &wait);

		if (vb->need_stats_update)
			stats_handle_request(vb);
		if (diff > 0)
			fill_balloon(vb, diff);
		else if (diff < 0)
			leak_balloon(vb, -diff);
		update_balloon_size(vb);

		/*
		 * For large balloon changes, we could spend a lot of time
		 * and always have work to do.  Be nice if preempt disabled.
		 */
		cond_resched();
	}
	return 0;
}
예제 #2
0
파일: smc_close.c 프로젝트: guribe94/linux
/* wait for sndbuf data being transmitted */
static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct sock *sk = &smc->sk;

	if (!timeout)
		return;

	if (!smc_tx_prepared_sends(&smc->conn))
		return;

	smc->wait_close_tx_prepared = 1;
	add_wait_queue(sk_sleep(sk), &wait);
	while (!signal_pending(current) && timeout) {
		int rc;

		rc = sk_wait_event(sk, &timeout,
				   !smc_tx_prepared_sends(&smc->conn) ||
				   (sk->sk_err == ECONNABORTED) ||
				   (sk->sk_err == ECONNRESET),
				   &wait);
		if (rc)
			break;
	}
	remove_wait_queue(sk_sleep(sk), &wait);
	smc->wait_close_tx_prepared = 0;
}
예제 #3
0
static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
			     int flags)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct sock *sk = sock->sk, *nsk;
	long timeo;
	int err = 0;

	lock_sock_nested(sk, L2CAP_NESTING_PARENT);

	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	BT_DBG("sk %p timeo %ld", sk, timeo);

	/* Wait for an incoming connection. (wake-one). */
	add_wait_queue_exclusive(sk_sleep(sk), &wait);
	while (1) {
		if (sk->sk_state != BT_LISTEN) {
			err = -EBADFD;
			break;
		}

		nsk = bt_accept_dequeue(sk, newsock);
		if (nsk)
			break;

		if (!timeo) {
			err = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			err = sock_intr_errno(timeo);
			break;
		}

		release_sock(sk);

		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);

		lock_sock_nested(sk, L2CAP_NESTING_PARENT);
	}
	remove_wait_queue(sk_sleep(sk), &wait);

	if (err)
		goto done;

	newsock->state = SS_CONNECTED;

	BT_DBG("new socket %p", nsk);

done:
	release_sock(sk);
	return err;
}
/*
 * Wait for a packet..
 */
static int wait_for_packet(struct sock *sk, int *err, long *timeo_p)
{
	int error;
	DEFINE_WAIT_FUNC(wait, receiver_wake_function);
    /* 
     前面的操作都是初始化wait,为将socket加入wait队列作准备,这部分代码牵涉到进程调度。关于进程调度,我      只是知道一些皮毛,留在以后学习。这里只需要将其看作是一些加入wait队列的准备工作即可,并不影响理解代码      。
     */
	prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

	/* Socket errors? */
	error = sock_error(sk);
	if (error)
		goto out_err;
    /* 一个完备检测。在决定wait和调用wait之间,有数据包到了,那么就不需要wait,所以这里再次检查socket      的队列是否为空 */

	if (!skb_queue_empty(&sk->sk_receive_queue))
		goto out;

	/* Socket shut down? */
	/* 完备检测。也许socket无数据包读取,因为socket已经被另外的线程关闭了。这样可以保证关闭socket的时      候,不会导致其他的socket的读写操作被阻塞。*/
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		goto out_noerr;

	/* Sequenced packets can come disconnected.
	 * If so we report the problem
	 *//* 对于面向连接的socket进行检查。如果是面向连接的socket,如果不是已经建立连接或者正在监听状态的so       cket是不可能有数据包的。不然即出错*/
	error = -ENOTCONN;
	if (connection_based(sk) &&
	    !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN))
		goto out_err;

	/* handle signals */
	if (signal_pending(current))/* 检查是否有pending的signal,保证阻塞时,进程可以被signal唤醒 */
		goto interrupted;

	error = 0;
	*timeo_p = schedule_timeout(*timeo_p); /* sleep本进程,直至满足唤醒条件或者被信号唤醒——因为前面设置了TASK_INTERRUPTIBLE*/
out:
	finish_wait(sk_sleep(sk), &wait); /* wait队列的清理工作 */
	return error;
interrupted:
	error = sock_intr_errno(*timeo_p);
out_err:
	*err = error;
	goto out;
out_noerr:
	*err = 0;
	error = 1;
	goto out;
}
예제 #5
0
/* blocks sndbuf producer until at least one byte of free space available */
static int smc_tx_wait_memory(struct smc_sock *smc, int flags)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct smc_connection *conn = &smc->conn;
	struct sock *sk = &smc->sk;
	bool noblock;
	long timeo;
	int rc = 0;

	/* similar to sk_stream_wait_memory */
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
	noblock = timeo ? false : true;
	add_wait_queue(sk_sleep(sk), &wait);
	while (1) {
		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
		if (sk->sk_err ||
		    (sk->sk_shutdown & SEND_SHUTDOWN) ||
		    conn->local_tx_ctrl.conn_state_flags.peer_done_writing) {
			rc = -EPIPE;
			break;
		}
		if (smc_cdc_rxed_any_close(conn)) {
			rc = -ECONNRESET;
			break;
		}
		if (!timeo) {
			if (noblock)
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
			rc = -EAGAIN;
			break;
		}
		if (signal_pending(current)) {
			rc = sock_intr_errno(timeo);
			break;
		}
		sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
		if (atomic_read(&conn->sndbuf_space))
			break; /* at least 1 byte of free space available */
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
		sk_wait_event(sk, &timeo,
			      sk->sk_err ||
			      (sk->sk_shutdown & SEND_SHUTDOWN) ||
			      smc_cdc_rxed_any_close(conn) ||
			      atomic_read(&conn->sndbuf_space),
			      &wait);
	}
	remove_wait_queue(sk_sleep(sk), &wait);
	return rc;
}
예제 #6
0
파일: datagram.c 프로젝트: 3null/linux
/*
 * Wait for the last received packet to be different from skb
 */
static int wait_for_more_packets(struct sock *sk, int *err, long *timeo_p,
				 const struct sk_buff *skb)
{
	int error;
	DEFINE_WAIT_FUNC(wait, receiver_wake_function);

	prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

	/* Socket errors? */
	error = sock_error(sk);
	if (error)
		goto out_err;

	if (sk->sk_receive_queue.prev != skb)
		goto out;

	/* Socket shut down? */
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		goto out_noerr;

	/* Sequenced packets can come disconnected.
	 * If so we report the problem
	 */
	error = -ENOTCONN;
	if (connection_based(sk) &&
	    !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN))
		goto out_err;

	/* handle signals */
	if (signal_pending(current))
		goto interrupted;

	error = 0;
	*timeo_p = schedule_timeout(*timeo_p);
out:
	finish_wait(sk_sleep(sk), &wait);
	return error;
interrupted:
	error = sock_intr_errno(*timeo_p);
out_err:
	*err = error;
	goto out;
out_noerr:
	*err = 0;
	error = 1;
	goto out;
}
예제 #7
0
static int wait_for_packet(struct sock *sk, int *err, long *timeo_p)
{
	int error;
	DEFINE_WAIT_FUNC(wait, receiver_wake_function);

	prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

	
	error = sock_error(sk);
	if (error)
		goto out_err;

	if (!skb_queue_empty(&sk->sk_receive_queue))
		goto out;

	
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		goto out_noerr;

	error = -ENOTCONN;
	if (connection_based(sk) &&
	    !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN))
		goto out_err;

	
	if (signal_pending(current))
		goto interrupted;

	error = 0;
	*timeo_p = schedule_timeout(*timeo_p);
out:
	finish_wait(sk_sleep(sk), &wait);
	return error;
interrupted:
	error = sock_intr_errno(*timeo_p);
out_err:
	*err = error;
	goto out;
out_noerr:
	*err = 0;
	error = 1;
	goto out;
}
예제 #8
0
static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
				size_t len)
{
	struct sock *sk;
	struct vsock_sock *vsk;
	ssize_t total_written;
	long timeout;
	int err;
	struct vsock_transport_send_notify_data send_data;
	DEFINE_WAIT_FUNC(wait, woken_wake_function);

	sk = sock->sk;
	vsk = vsock_sk(sk);
	total_written = 0;
	err = 0;

	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	lock_sock(sk);

	/* Callers should not provide a destination with stream sockets. */
	if (msg->msg_namelen) {
		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
		goto out;
	}

	/* Send data only if both sides are not shutdown in the direction. */
	if (sk->sk_shutdown & SEND_SHUTDOWN ||
	    vsk->peer_shutdown & RCV_SHUTDOWN) {
		err = -EPIPE;
		goto out;
	}

	if (sk->sk_state != TCP_ESTABLISHED ||
	    !vsock_addr_bound(&vsk->local_addr)) {
		err = -ENOTCONN;
		goto out;
	}

	if (!vsock_addr_bound(&vsk->remote_addr)) {
		err = -EDESTADDRREQ;
		goto out;
	}

	/* Wait for room in the produce queue to enqueue our user's data. */
	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);

	err = transport->notify_send_init(vsk, &send_data);
	if (err < 0)
		goto out;

	while (total_written < len) {
		ssize_t written;

		add_wait_queue(sk_sleep(sk), &wait);
		while (vsock_stream_has_space(vsk) == 0 &&
		       sk->sk_err == 0 &&
		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {

			/* Don't wait for non-blocking sockets. */
			if (timeout == 0) {
				err = -EAGAIN;
				remove_wait_queue(sk_sleep(sk), &wait);
				goto out_err;
			}

			err = transport->notify_send_pre_block(vsk, &send_data);
			if (err < 0) {
				remove_wait_queue(sk_sleep(sk), &wait);
				goto out_err;
			}

			release_sock(sk);
			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
			lock_sock(sk);
			if (signal_pending(current)) {
				err = sock_intr_errno(timeout);
				remove_wait_queue(sk_sleep(sk), &wait);
				goto out_err;
			} else if (timeout == 0) {
				err = -EAGAIN;
				remove_wait_queue(sk_sleep(sk), &wait);
				goto out_err;
			}
		}
		remove_wait_queue(sk_sleep(sk), &wait);

		/* These checks occur both as part of and after the loop
		 * conditional since we need to check before and after
		 * sleeping.
		 */
		if (sk->sk_err) {
			err = -sk->sk_err;
			goto out_err;
		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
			err = -EPIPE;
			goto out_err;
		}

		err = transport->notify_send_pre_enqueue(vsk, &send_data);
		if (err < 0)
			goto out_err;

		/* Note that enqueue will only write as many bytes as are free
		 * in the produce queue, so we don't need to ensure len is
		 * smaller than the queue size.  It is the caller's
		 * responsibility to check how many bytes we were able to send.
		 */

		written = transport->stream_enqueue(
				vsk, msg,
				len - total_written);
		if (written < 0) {
			err = -ENOMEM;
			goto out_err;
		}

		total_written += written;

		err = transport->notify_send_post_enqueue(
				vsk, written, &send_data);
		if (err < 0)
			goto out_err;

	}

out_err:
	if (total_written > 0)
		err = total_written;
out:
	release_sock(sk);
	return err;
}
예제 #9
0
int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
{
	struct virtio_vsock_pkt_info info = {
		.op = VIRTIO_VSOCK_OP_SHUTDOWN,
		.type = VIRTIO_VSOCK_TYPE_STREAM,
		.flags = (mode & RCV_SHUTDOWN ?
			  VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
			 (mode & SEND_SHUTDOWN ?
			  VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
		.vsk = vsk,
	};

	return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_shutdown);

int
virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
			       struct sockaddr_vm *remote_addr,
			       struct msghdr *msg,
			       size_t dgram_len)
{
	return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);

ssize_t
virtio_transport_stream_enqueue(struct vsock_sock *vsk,
				struct msghdr *msg,
				size_t len)
{
	struct virtio_vsock_pkt_info info = {
		.op = VIRTIO_VSOCK_OP_RW,
		.type = VIRTIO_VSOCK_TYPE_STREAM,
		.msg = msg,
		.pkt_len = len,
		.vsk = vsk,
	};

	return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);

void virtio_transport_destruct(struct vsock_sock *vsk)
{
	struct virtio_vsock_sock *vvs = vsk->trans;

	kfree(vvs);
}
EXPORT_SYMBOL_GPL(virtio_transport_destruct);

static int virtio_transport_reset(struct vsock_sock *vsk,
				  struct virtio_vsock_pkt *pkt)
{
	struct virtio_vsock_pkt_info info = {
		.op = VIRTIO_VSOCK_OP_RST,
		.type = VIRTIO_VSOCK_TYPE_STREAM,
		.reply = !!pkt,
		.vsk = vsk,
	};

	/* Send RST only if the original pkt is not a RST pkt */
	if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
		return 0;

	return virtio_transport_send_pkt_info(vsk, &info);
}

/* Normally packets are associated with a socket.  There may be no socket if an
 * attempt was made to connect to a socket that does not exist.
 */
static int virtio_transport_reset_no_sock(struct virtio_vsock_pkt *pkt)
{
	struct virtio_vsock_pkt_info info = {
		.op = VIRTIO_VSOCK_OP_RST,
		.type = le16_to_cpu(pkt->hdr.type),
		.reply = true,
	};

	/* Send RST only if the original pkt is not a RST pkt */
	if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
		return 0;

	pkt = virtio_transport_alloc_pkt(&info, 0,
					 le64_to_cpu(pkt->hdr.dst_cid),
					 le32_to_cpu(pkt->hdr.dst_port),
					 le64_to_cpu(pkt->hdr.src_cid),
					 le32_to_cpu(pkt->hdr.src_port));
	if (!pkt)
		return -ENOMEM;

	return virtio_transport_get_ops()->send_pkt(pkt);
}

static void virtio_transport_wait_close(struct sock *sk, long timeout)
{
	if (timeout) {
		DEFINE_WAIT_FUNC(wait, woken_wake_function);

		add_wait_queue(sk_sleep(sk), &wait);

		do {
			if (sk_wait_event(sk, &timeout,
					  sock_flag(sk, SOCK_DONE), &wait))
				break;
		} while (!signal_pending(current) && timeout);

		remove_wait_queue(sk_sleep(sk), &wait);
	}
}

static void virtio_transport_do_close(struct vsock_sock *vsk,
				      bool cancel_timeout)
{
	struct sock *sk = sk_vsock(vsk);

	sock_set_flag(sk, SOCK_DONE);
	vsk->peer_shutdown = SHUTDOWN_MASK;
	if (vsock_stream_has_data(vsk) <= 0)
		sk->sk_state = SS_DISCONNECTING;
	sk->sk_state_change(sk);

	if (vsk->close_work_scheduled &&
	    (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
		vsk->close_work_scheduled = false;

		vsock_remove_sock(vsk);

		/* Release refcnt obtained when we scheduled the timeout */
		sock_put(sk);
	}
}

static void virtio_transport_close_timeout(struct work_struct *work)
{
	struct vsock_sock *vsk =
		container_of(work, struct vsock_sock, close_work.work);
	struct sock *sk = sk_vsock(vsk);

	sock_hold(sk);
	lock_sock(sk);

	if (!sock_flag(sk, SOCK_DONE)) {
		(void)virtio_transport_reset(vsk, NULL);

		virtio_transport_do_close(vsk, false);
	}

	vsk->close_work_scheduled = false;

	release_sock(sk);
	sock_put(sk);
}

/* User context, vsk->sk is locked */
static bool virtio_transport_close(struct vsock_sock *vsk)
{
	struct sock *sk = &vsk->sk;

	if (!(sk->sk_state == SS_CONNECTED ||
	      sk->sk_state == SS_DISCONNECTING))
		return true;

	/* Already received SHUTDOWN from peer, reply with RST */
	if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
		(void)virtio_transport_reset(vsk, NULL);
		return true;
	}

	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
		(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);

	if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
		virtio_transport_wait_close(sk, sk->sk_lingertime);

	if (sock_flag(sk, SOCK_DONE)) {
		return true;
	}

	sock_hold(sk);
	INIT_DELAYED_WORK(&vsk->close_work,
			  virtio_transport_close_timeout);
	vsk->close_work_scheduled = true;
	schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
	return false;
}

void virtio_transport_release(struct vsock_sock *vsk)
{
	struct sock *sk = &vsk->sk;
	bool remove_sock = true;

	lock_sock(sk);
	if (sk->sk_type == SOCK_STREAM)
		remove_sock = virtio_transport_close(vsk);
	release_sock(sk);

	if (remove_sock)
		vsock_remove_sock(vsk);
}
EXPORT_SYMBOL_GPL(virtio_transport_release);

static int
virtio_transport_recv_connecting(struct sock *sk,
				 struct virtio_vsock_pkt *pkt)
{
	struct vsock_sock *vsk = vsock_sk(sk);
	int err;
	int skerr;

	switch (le16_to_cpu(pkt->hdr.op)) {
	case VIRTIO_VSOCK_OP_RESPONSE:
		sk->sk_state = SS_CONNECTED;
		sk->sk_socket->state = SS_CONNECTED;
		vsock_insert_connected(vsk);
		sk->sk_state_change(sk);
		break;
	case VIRTIO_VSOCK_OP_INVALID:
		break;
	case VIRTIO_VSOCK_OP_RST:
		skerr = ECONNRESET;
		err = 0;
		goto destroy;
	default:
		skerr = EPROTO;
		err = -EINVAL;
		goto destroy;
	}
	return 0;

destroy:
	virtio_transport_reset(vsk, pkt);
	sk->sk_state = SS_UNCONNECTED;
	sk->sk_err = skerr;
	sk->sk_error_report(sk);
	return err;
}

static int
virtio_transport_recv_connected(struct sock *sk,
				struct virtio_vsock_pkt *pkt)
{
	struct vsock_sock *vsk = vsock_sk(sk);
	struct virtio_vsock_sock *vvs = vsk->trans;
	int err = 0;

	switch (le16_to_cpu(pkt->hdr.op)) {
	case VIRTIO_VSOCK_OP_RW:
		pkt->len = le32_to_cpu(pkt->hdr.len);
		pkt->off = 0;

		spin_lock_bh(&vvs->rx_lock);
		virtio_transport_inc_rx_pkt(vvs, pkt);
		list_add_tail(&pkt->list, &vvs->rx_queue);
		spin_unlock_bh(&vvs->rx_lock);

		sk->sk_data_ready(sk);
		return err;
	case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
		sk->sk_write_space(sk);
		break;
	case VIRTIO_VSOCK_OP_SHUTDOWN:
		if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
			vsk->peer_shutdown |= RCV_SHUTDOWN;
		if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
			vsk->peer_shutdown |= SEND_SHUTDOWN;
		if (vsk->peer_shutdown == SHUTDOWN_MASK &&
		    vsock_stream_has_data(vsk) <= 0)
			sk->sk_state = SS_DISCONNECTING;
		if (le32_to_cpu(pkt->hdr.flags))
			sk->sk_state_change(sk);
		break;
	case VIRTIO_VSOCK_OP_RST:
		virtio_transport_do_close(vsk, true);
		break;
	default:
		err = -EINVAL;
		break;
	}

	virtio_transport_free_pkt(pkt);
	return err;
}

static void
virtio_transport_recv_disconnecting(struct sock *sk,
				    struct virtio_vsock_pkt *pkt)
{
	struct vsock_sock *vsk = vsock_sk(sk);

	if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
		virtio_transport_do_close(vsk, true);
}

static int
virtio_transport_send_response(struct vsock_sock *vsk,
			       struct virtio_vsock_pkt *pkt)
{
	struct virtio_vsock_pkt_info info = {
		.op = VIRTIO_VSOCK_OP_RESPONSE,
		.type = VIRTIO_VSOCK_TYPE_STREAM,
		.remote_cid = le64_to_cpu(pkt->hdr.src_cid),
		.remote_port = le32_to_cpu(pkt->hdr.src_port),
		.reply = true,
		.vsk = vsk,
	};

	return virtio_transport_send_pkt_info(vsk, &info);
}

/* Handle server socket */
static int
virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
{
	struct vsock_sock *vsk = vsock_sk(sk);
	struct vsock_sock *vchild;
	struct sock *child;

	if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
		virtio_transport_reset(vsk, pkt);
		return -EINVAL;
	}

	if (sk_acceptq_is_full(sk)) {
		virtio_transport_reset(vsk, pkt);
		return -ENOMEM;
	}

	child = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
			       sk->sk_type, 0);
	if (!child) {
		virtio_transport_reset(vsk, pkt);
		return -ENOMEM;
	}

	sk->sk_ack_backlog++;

	lock_sock_nested(child, SINGLE_DEPTH_NESTING);

	child->sk_state = SS_CONNECTED;

	vchild = vsock_sk(child);
	vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
			le32_to_cpu(pkt->hdr.dst_port));
	vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
			le32_to_cpu(pkt->hdr.src_port));

	vsock_insert_connected(vchild);
	vsock_enqueue_accept(sk, child);
	virtio_transport_send_response(vchild, pkt);

	release_sock(child);

	sk->sk_data_ready(sk);
	return 0;
}

static bool virtio_transport_space_update(struct sock *sk,
					  struct virtio_vsock_pkt *pkt)
{
	struct vsock_sock *vsk = vsock_sk(sk);
	struct virtio_vsock_sock *vvs = vsk->trans;
	bool space_available;

	/* buf_alloc and fwd_cnt is always included in the hdr */
	spin_lock_bh(&vvs->tx_lock);
	vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
	vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
	space_available = virtio_transport_has_space(vsk);
	spin_unlock_bh(&vvs->tx_lock);
	return space_available;
}

/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
 * lock.
 */
void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
{
	struct sockaddr_vm src, dst;
	struct vsock_sock *vsk;
	struct sock *sk;
	bool space_available;

	vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
			le32_to_cpu(pkt->hdr.src_port));
	vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
			le32_to_cpu(pkt->hdr.dst_port));

	trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
					dst.svm_cid, dst.svm_port,
					le32_to_cpu(pkt->hdr.len),
					le16_to_cpu(pkt->hdr.type),
					le16_to_cpu(pkt->hdr.op),
					le32_to_cpu(pkt->hdr.flags),
					le32_to_cpu(pkt->hdr.buf_alloc),
					le32_to_cpu(pkt->hdr.fwd_cnt));

	if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
		(void)virtio_transport_reset_no_sock(pkt);
		goto free_pkt;
	}

	/* The socket must be in connected or bound table
	 * otherwise send reset back
	 */
	sk = vsock_find_connected_socket(&src, &dst);
	if (!sk) {
		sk = vsock_find_bound_socket(&dst);
		if (!sk) {
			(void)virtio_transport_reset_no_sock(pkt);
			goto free_pkt;
		}
	}

	vsk = vsock_sk(sk);

	space_available = virtio_transport_space_update(sk, pkt);

	lock_sock(sk);

	/* Update CID in case it has changed after a transport reset event */
	vsk->local_addr.svm_cid = dst.svm_cid;

	if (space_available)
		sk->sk_write_space(sk);

	switch (sk->sk_state) {
	case VSOCK_SS_LISTEN:
		virtio_transport_recv_listen(sk, pkt);
		virtio_transport_free_pkt(pkt);
		break;
	case SS_CONNECTING:
		virtio_transport_recv_connecting(sk, pkt);
		virtio_transport_free_pkt(pkt);
		break;
	case SS_CONNECTED:
		virtio_transport_recv_connected(sk, pkt);
		break;
	case SS_DISCONNECTING:
		virtio_transport_recv_disconnecting(sk, pkt);
		virtio_transport_free_pkt(pkt);
		break;
	default:
		virtio_transport_free_pkt(pkt);
		break;
	}
	release_sock(sk);

	/* Release refcnt obtained when we fetched this socket out of the
	 * bound or connected list.
	 */
	sock_put(sk);
	return;

free_pkt:
	virtio_transport_free_pkt(pkt);
}
EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);

void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
{
	kfree(pkt->buf);
	kfree(pkt);
}
EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("common code for virtio vsock");