Subject: Re: [RFC 2/5] VSOCK: Introduce virtio-vsock-common.ko

From: "Michael S. Tsirkin" <[email-masked]>
Date: Thu, 27 Jun 2013 13:34:30 +0300

On Thu, Jun 27, 2013 at 04:00:01PM +0800, Asias He wrote:
> This module contains the common code and header files for the following
> virtio-vsock and virtio-vhost kernel modules.
> 
> Signed-off-by: Asias He <[email-masked]>
> ---
>  include/linux/virtio_vsock.h            | 200 +++++++
>  include/uapi/linux/virtio_ids.h         |   1 +
>  include/uapi/linux/virtio_vsock.h       |  70 +++
>  net/vmw_vsock/virtio_transport_common.c | 992 ++++++++++++++++++++++++++++++++
>  4 files changed, 1263 insertions(+)
>  create mode 100644 include/linux/virtio_vsock.h
>  create mode 100644 include/uapi/linux/virtio_vsock.h
>  create mode 100644 net/vmw_vsock/virtio_transport_common.c
> 
> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> new file mode 100644
> index 0000000..cd8ed95
> --- /dev/null
> +++ b/include/linux/virtio_vsock.h
> @@ -0,0 +1,200 @@
> +/*
> + * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
> + * anyone can use the definitions to implement compatible drivers/servers:
> + *
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of IBM nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + *
> + * Copyright (C) Red Hat, Inc., 2013
> + * Copyright (C) Asias He <[email-masked]>, 2013
> + */
> +
> +#ifndef _LINUX_VIRTIO_VSOCK_H
> +#define _LINUX_VIRTIO_VSOCK_H
> +
> +#include <uapi/linux/virtio_vsock.h>
> +#include <linux/socket.h>
> +#include <net/sock.h>
> +
> +#define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE	128
> +#define VIRTIO_VSOCK_DEFAULT_BUF_SIZE		(1024 * 256)
> +#define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE	(1024 * 256)
> +#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE	(1024 * 4)
> +#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE		(1024 * 64)
> +
> +struct vsock_transport_recv_notify_data;
> +struct vsock_transport_send_notify_data;
> +struct sockaddr_vm;
> +struct vsock_sock;
> +
> +enum {
> +	VSOCK_VQ_CTRL	= 0,
> +	VSOCK_VQ_RX	= 1, /* for host to guest data */
> +	VSOCK_VQ_TX	= 2, /* for guest to host data */
> +	VSOCK_VQ_MAX	= 3,
> +};
> +
> +/* virtio transport socket state */
> +struct virtio_transport {
> +	struct virtio_transport_pkt_ops	*ops;
> +	struct vsock_sock *vsk;
> +
> +	u64 buf_size;
> +	u64 buf_size_min;
> +	u64 buf_size_max;
> +
> +	struct mutex tx_lock;
> +	struct mutex rx_lock;
> +
> +	struct list_head rx_queue;
> +	u64 rx_bytes;
> +
> +	/* Protected by trans->tx_lock */
> +	u64 tx_cnt;
> +	u64 buf_alloc;
> +	u64 peer_fwd_cnt;
> +	u64 peer_buf_alloc;
> +	/* Protected by trans->rx_lock */
> +	u64 fwd_cnt;
> +};
> +
> +struct virtio_vsock_pkt {
> +	struct virtio_vsock_hdr	hdr;
> +	struct virtio_transport	*trans;
> +	struct work_struct work;
> +	struct list_head list;
> +	void *buf;
> +	u32 len;
> +	u32 off;
> +};
> +
> +struct virtio_vsock_pkt_info {
> +	struct sockaddr_vm *src;
> +	struct sockaddr_vm *dst;
> +	struct iovec *iov;
> +	u32 len;
> +	u8 type;
> +	u8 op;
> +	u8 shut;
> +};
> +
> +struct virtio_transport_pkt_ops {
> +	int (*send_pkt)(struct vsock_sock *vsk,
> +			struct virtio_vsock_pkt_info *info);
> +};
> +
> +void virtio_vsock_dumppkt(const char *func,
> +			  const struct virtio_vsock_pkt *pkt);
> +
> +struct sock *
> +virtio_transport_get_pending(struct sock *listener,
> +			     struct virtio_vsock_pkt *pkt);
> +struct virtio_vsock_pkt *
> +virtio_transport_alloc_pkt(struct vsock_sock *vsk,
> +			   struct virtio_vsock_pkt_info *info,
> +			   size_t len,
> +			   u32 src_cid,
> +			   u32 src_port,
> +			   u32 dst_cid,
> +			   u32 dst_port);
> +ssize_t
> +virtio_transport_stream_dequeue(struct vsock_sock *vsk,
> +				struct iovec *iov,
> +				size_t len,
> +				int type);
> +int
> +virtio_transport_dgram_dequeue(struct kiocb *kiocb,
> +			       struct vsock_sock *vsk,
> +			       struct msghdr *msg,
> +			       size_t len, int flags);
> +
> +s64 virtio_transport_stream_has_data(struct vsock_sock *vsk);
> +s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
> +
> +int virtio_transport_do_socket_init(struct vsock_sock *vsk,
> +				 struct vsock_sock *psk);
> +u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk);
> +u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk);
> +u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk);
> +void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val);
> +void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val);
> +void virtio_transport_set_max_buffer_size(struct vsock_sock *vs, u64 val);
> +int
> +virtio_transport_notify_poll_in(struct vsock_sock *vsk,
> +				size_t target,
> +				bool *data_ready_now);
> +int
> +virtio_transport_notify_poll_out(struct vsock_sock *vsk,
> +				 size_t target,
> +				 bool *space_available_now);
> +
> +int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data);
> +int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data);
> +int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data);
> +int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
> +	size_t target, ssize_t copied, bool data_read,
> +	struct vsock_transport_recv_notify_data *data);
> +int virtio_transport_notify_send_init(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data);
> +int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data);
> +int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data);
> +int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
> +	ssize_t written, struct vsock_transport_send_notify_data *data);
> +
> +u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
> +bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
> +bool virtio_transport_stream_allow(u32 cid, u32 port);
> +int virtio_transport_dgram_bind(struct vsock_sock *vsk,
> +				struct sockaddr_vm *addr);
> +bool virtio_transport_dgram_allow(u32 cid, u32 port);
> +
> +int virtio_transport_connect(struct vsock_sock *vsk);
> +
> +int virtio_transport_shutdown(struct vsock_sock *vsk, int mode);
> +
> +void virtio_transport_release(struct vsock_sock *vsk);
> +
> +ssize_t
> +virtio_transport_stream_enqueue(struct vsock_sock *vsk,
> +				struct iovec *iov,
> +				size_t len);
> +int
> +virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
> +			       struct sockaddr_vm *remote_addr,
> +			       struct iovec *iov,
> +			       size_t len);
> +
> +void virtio_transport_destruct(struct vsock_sock *vsk);
> +
> +void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt);
> +void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt);
> +void virtio_transport_inc_tx_pkt(struct virtio_vsock_pkt *pkt);
> +void virtio_transport_dec_tx_pkt(struct virtio_vsock_pkt *pkt);
> +u64 virtio_transport_get_credit(struct virtio_transport *trans);
> +#endif /* _LINUX_VIRTIO_VSOCK_H */
> diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
> index 284fc3a..8a27609 100644
> --- a/include/uapi/linux/virtio_ids.h
> +++ b/include/uapi/linux/virtio_ids.h
> @@ -39,5 +39,6 @@
>  #define VIRTIO_ID_9P		9 /* 9p virtio console */
>  #define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */
>  #define VIRTIO_ID_CAIF	       12 /* Virtio caif */
> +#define VIRTIO_ID_VSOCK        13 /* virtio vsock transport */
>  
>  #endif /* _LINUX_VIRTIO_IDS_H */
> diff --git a/include/uapi/linux/virtio_vsock.h b/include/uapi/linux/virtio_vsock.h
> new file mode 100644
> index 0000000..0a58ac3
> --- /dev/null
> +++ b/include/uapi/linux/virtio_vsock.h
> @@ -0,0 +1,70 @@
> +/*
> + * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
> + * anyone can use the definitions to implement compatible drivers/servers:
> + *
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of IBM nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + *
> + * Copyright (C) Red Hat, Inc., 2013
> + * Copyright (C) Asias He <[email-masked]>, 2013
> + */
> +
> +#ifndef _UAPI_LINUX_VIRTIO_VSOCK_H
> +#define _UAPI_LINUX_VIRTIO_VOSCK_H
> +
> +#include <linux/types.h>
> +#include <linux/virtio_ids.h>
> +#include <linux/virtio_config.h>
> +
> +struct virtio_vsock_config {
> +	__u32 guest_cid;
> +	__u32 max_virtqueue_pairs;
> +} __packed;
> +
> +struct virtio_vsock_hdr {
> +	__u32	src_cid;
> +	__u32	src_port;
> +	__u32	dst_cid;
> +	__u32	dst_port;
> +	__u32	len;
> +	__u8	type;
> +	__u8	op;
> +	__u8	shut;
> +	__u64	fwd_cnt;
> +	__u64	buf_alloc;
> +} __packed;
> +
> +enum {
> +	VIRTIO_VSOCK_OP_INVALID = 0,
> +	VIRTIO_VSOCK_OP_REQUEST = 1,
> +	VIRTIO_VSOCK_OP_NEGOTIATE = 2,
> +	VIRTIO_VSOCK_OP_OFFER = 3,
> +	VIRTIO_VSOCK_OP_ATTACH = 4,
> +	VIRTIO_VSOCK_OP_RW = 5,
> +	VIRTIO_VSOCK_OP_CREDIT = 6,
> +	VIRTIO_VSOCK_OP_RST = 7,
> +	VIRTIO_VSOCK_OP_SHUTDOWN = 8,
> +};
> +
> +#endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> new file mode 100644
> index 0000000..0482eb1
> --- /dev/null
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -0,0 +1,992 @@
> +/*
> + * common code for virtio vsock
> + *
> + * Copyright (C) 2013 Red Hat, Inc.
> + * Author: Asias He <[email-masked]>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + */
> +#include <linux/module.h>
> +#include <linux/ctype.h>
> +#include <linux/list.h>
> +#include <linux/virtio.h>
> +#include <linux/virtio_ids.h>
> +#include <linux/virtio_config.h>
> +#include <linux/virtio_vsock.h>
> +
> +#include <net/sock.h>
> +#include "af_vsock.h"
> +
> +#define SS_LISTEN 255
> +
> +void virtio_vsock_dumppkt(const char *func,  const struct virtio_vsock_pkt *pkt)
> +{
> +	pr_debug("%s: pkt=%p, op=%d, len=%d, %d:%d---%d:%d, len=%d\n",
> +		 func, pkt, pkt->hdr.op, pkt->hdr.len,
> +		 pkt->hdr.src_cid, pkt->hdr.src_port,
> +		 pkt->hdr.dst_cid, pkt->hdr.dst_port, pkt->len);
> +}
> +EXPORT_SYMBOL_GPL(virtio_vsock_dumppkt);
> +
> +struct virtio_vsock_pkt *
> +virtio_transport_alloc_pkt(struct vsock_sock *vsk,
> +			   struct virtio_vsock_pkt_info *info,
> +			   size_t len,
> +			   u32 src_cid,
> +			   u32 src_port,
> +			   u32 dst_cid,
> +			   u32 dst_port)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt *pkt;
> +	int err;
> +
> +	BUG_ON(!trans);
> +
> +	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
> +	if (!pkt)
> +		return NULL;
> +
> +	pkt->hdr.type		= info->type;
> +	pkt->hdr.op		= info->op;
> +	pkt->hdr.src_cid	= src_cid;
> +	pkt->hdr.src_port	= src_port;
> +	pkt->hdr.dst_cid	= dst_cid;
> +	pkt->hdr.dst_port	= dst_port;
> +	pkt->hdr.len		= len;
> +	pkt->hdr.shut		= info->shut;
> +	pkt->len		= len;
> +	pkt->trans		= trans;
> +
> +	if (info->iov && len > 0) {
> +		pkt->buf = kmalloc(len, GFP_KERNEL);
> +		if (!pkt->buf)
> +			goto out_pkt;
> +		err = memcpy_fromiovec(pkt->buf, info->iov, len);
> +		if (err)
> +			goto out;
> +	}
> +
> +	return pkt;
> +
> +out:
> +	kfree(pkt->buf);
> +out_pkt:
> +	kfree(pkt);
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_alloc_pkt);
> +
> +struct sock *
> +virtio_transport_get_pending(struct sock *listener,
> +			     struct virtio_vsock_pkt *pkt)
> +{
> +	struct vsock_sock *vlistener;
> +	struct vsock_sock *vpending;
> +	struct sockaddr_vm src;
> +	struct sockaddr_vm dst;
> +	struct sock *pending;
> +
> +	vsock_addr_init(&src, pkt->hdr.src_cid, pkt->hdr.src_port);
> +	vsock_addr_init(&dst, pkt->hdr.dst_cid, pkt->hdr.dst_port);
> +
> +	vlistener = vsock_sk(listener);
> +	list_for_each_entry(vpending, &vlistener->pending_links,
> +			    pending_links) {
> +		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
> +		    vsock_addr_equals_addr(&dst, &vpending->local_addr)) {
> +			pending = sk_vsock(vpending);
> +			sock_hold(pending);
> +			return pending;
> +		}
> +	}
> +
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_get_pending);
> +
> +static void virtio_transport_inc_rx_pkt(struct virtio_vsock_pkt *pkt)
> +{
> +	pkt->trans->rx_bytes += pkt->len;
> +}
> +
> +static void virtio_transport_dec_rx_pkt(struct virtio_vsock_pkt *pkt)
> +{
> +	pkt->trans->rx_bytes -= pkt->len;
> +	pkt->trans->fwd_cnt += pkt->len;
> +}
> +
> +void virtio_transport_inc_tx_pkt(struct virtio_vsock_pkt *pkt)
> +{
> +	mutex_lock(&pkt->trans->tx_lock);
> +	pkt->hdr.fwd_cnt = pkt->trans->fwd_cnt;
> +	pkt->hdr.buf_alloc = pkt->trans->buf_alloc;
> +	pkt->trans->tx_cnt += pkt->len;
> +	mutex_unlock(&pkt->trans->tx_lock);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
> +
> +void virtio_transport_dec_tx_pkt(struct virtio_vsock_pkt *pkt)
> +{
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_dec_tx_pkt);
> +
> +u64 virtio_transport_get_credit(struct virtio_transport *trans)
> +{
> +	u64 credit;
> +
> +	mutex_lock(&trans->tx_lock);
> +	credit = trans->peer_buf_alloc - (trans->tx_cnt - trans->peer_fwd_cnt);
> +	mutex_unlock(&trans->tx_lock);

So two callers can call virtio_transport_get_credit and
both get a credit. Later credit gets negative.

You must have the lock until you increment tx_cnt I think.

> +
> +	pr_debug("credit=%lld, buf_alloc=%lld, peer_buf_alloc=%lld,"
> +		 "tx_cnt=%lld, fwd_cnt=%lld, peer_fwd_cnt=%lld\n",
> +		 credit, trans->buf_alloc, trans->peer_buf_alloc,
> +		 trans->tx_cnt, trans->fwd_cnt, trans->peer_fwd_cnt);
> +
> +	return credit;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
> +
> +static int virtio_transport_send_credit(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_CREDIT,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s: sk=%p send_credit\n", __func__, vsk);
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +
> +static ssize_t
> +virtio_transport_do_dequeue(struct vsock_sock *vsk,
> +			    struct iovec *iov,
> +			    size_t len,
> +			    int type)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt *pkt;
> +	size_t bytes, total = 0;
> +	int err = -EFAULT;
> +
> +	mutex_lock(&trans->rx_lock);
> +	while (total < len && trans->rx_bytes > 0  &&
> +			!list_empty(&trans->rx_queue)) {
> +		pkt = list_first_entry(&trans->rx_queue,
> +				       struct virtio_vsock_pkt, list);
> +
> +		if (pkt->hdr.type != type)
> +			continue;
> +
> +		bytes = len - total;
> +		if (bytes > pkt->len - pkt->off)
> +			bytes = pkt->len - pkt->off;
> +
> +		err = memcpy_toiovec(iov, pkt->buf + pkt->off, bytes);
> +		if (err)
> +			goto out;
> +		total += bytes;
> +		pkt->off += bytes;
> +		if (pkt->off == pkt->len) {
> +			virtio_transport_dec_rx_pkt(pkt);
> +			list_del(&pkt->list);
> +			virtio_transport_free_pkt(pkt);
> +		}
> +	}
> +	mutex_unlock(&trans->rx_lock);
> +
> +	/* Send a credit pkt to peer */
> +	if (type == SOCK_STREAM)
> +		virtio_transport_send_credit(vsk);
> +
> +	return total;
> +
> +out:
> +	mutex_unlock(&trans->rx_lock);
> +	if (total)
> +		err = total;
> +	return err;
> +}
> +
> +ssize_t
> +virtio_transport_stream_dequeue(struct vsock_sock *vsk,
> +				struct iovec *iov,
> +				size_t len, int flags)
> +{
> +	if (flags & MSG_PEEK)
> +		return -EOPNOTSUPP;
> +
> +	return virtio_transport_do_dequeue(vsk, iov, len, SOCK_STREAM);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
> +
> +static void
> +virtio_transport_recv_dgram(struct sock *sk,
> +			    struct virtio_vsock_pkt *pkt)
> +{
> +	struct sk_buff *skb;
> +	struct vsock_sock *vsk;
> +	size_t size;
> +
> +	vsk = vsock_sk(sk);
> +
> +	pkt->len = pkt->hdr.len;
> +	pkt->off = 0;
> +
> +	size = sizeof(*pkt) + pkt->len;
> +	/* Attach the packet to the socket's receive queue as an sk_buff. */
> +	skb = alloc_skb(size, GFP_ATOMIC);
> +	if (!skb)
> +		goto out;
> +
> +	/* sk_receive_skb() will do a sock_put(), so hold here. */
> +	sock_hold(sk);
> +	skb_put(skb, size);
> +	memcpy(skb->data, pkt, sizeof(*pkt));
> +	memcpy(skb->data + sizeof(*pkt), pkt->buf, pkt->len);
> +
> +	sk_receive_skb(sk, skb, 0);
> +out:
> +	virtio_transport_free_pkt(pkt);
> +}
> +
> +int
> +virtio_transport_dgram_dequeue(struct kiocb *kiocb,
> +			       struct vsock_sock *vsk,
> +			       struct msghdr *msg,
> +			       size_t len, int flags)
> +{
> +	struct virtio_vsock_pkt *pkt;
> +	struct sk_buff *skb;
> +	size_t payload_len;
> +	int noblock;
> +	int err;
> +
> +	noblock = flags & MSG_DONTWAIT;
> +
> +	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> +		return -EOPNOTSUPP;
> +
> +	msg->msg_namelen = 0;
> +
> +	/* Retrieve the head sk_buff from the socket's receive queue. */
> +	err = 0;
> +	skb = skb_recv_datagram(&vsk->sk, flags, noblock, &err);
> +	if (err)
> +		return err;
> +	if (!skb)
> +		return -EAGAIN;
> +
> +	pkt = (struct virtio_vsock_pkt *)skb->data;
> +	if (!pkt)
> +		goto out;
> +
> +	/* FIXME: check payload_len */
> +	payload_len = pkt->len;
> +
> +	/* Place the datagram payload in the user's iovec. */
> +	err = skb_copy_datagram_iovec(skb, sizeof(*pkt),
> +				      msg->msg_iov, payload_len);
> +	if (err)
> +		goto out;
> +
> +	if (msg->msg_name) {
> +		struct sockaddr_vm *vm_addr;
> +
> +		/* Provide the address of the sender. */
> +		vm_addr = (struct sockaddr_vm *)msg->msg_name;
> +		vsock_addr_init(vm_addr, pkt->hdr.src_cid, pkt->hdr.src_port);
> +		msg->msg_namelen = sizeof(*vm_addr);
> +	}
> +	err = payload_len;
> +
> +out:
> +	skb_free_datagram(&vsk->sk, skb);
> +	return err;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
> +
> +s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	size_t bytes = 0;
> +
> +	mutex_lock(&trans->rx_lock);
> +	bytes = trans->rx_bytes;
> +	mutex_unlock(&trans->rx_lock);
> +
> +	return bytes;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
> +
> +static s64 __virtio_transport_stream_has_space(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	size_t bytes = 0;
> +
> +	bytes = trans->peer_buf_alloc - (trans->tx_cnt - trans->peer_fwd_cnt);
> +	if (bytes < 0)
> +		bytes = 0;
> +
> +	return bytes;
> +}
> +
> +s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	size_t bytes = 0;
> +
> +	mutex_lock(&trans->tx_lock);
> +	bytes = trans->peer_buf_alloc - (trans->tx_cnt - trans->peer_fwd_cnt);
> +	if (bytes < 0)
> +		bytes = 0;
> +	mutex_unlock(&trans->tx_lock);
> +	pr_debug("%s: bytes=%ld\n", __func__, bytes);
> +
> +	return bytes;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
> +
> +int virtio_transport_do_socket_init(struct vsock_sock *vsk,
> +				    struct vsock_sock *psk)
> +{
> +	struct virtio_transport *trans;
> +
> +	trans = kzalloc(sizeof(*trans), GFP_KERNEL);
> +	if (!trans)
> +		return -ENOMEM;
> +
> +	vsk->trans = trans;
> +	trans->vsk = vsk;
> +	if (psk) {
> +		struct virtio_transport *ptrans = psk->trans;
> +		trans->buf_size	= ptrans->buf_size;
> +		trans->buf_size_min = ptrans->buf_size_min;
> +		trans->buf_size_max = ptrans->buf_size_max;
> +	} else {
> +		trans->buf_size = VIRTIO_VSOCK_DEFAULT_BUF_SIZE;
> +		trans->buf_size_min = VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE;
> +		trans->buf_size_max = VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE;
> +	}
> +
> +	trans->buf_alloc = trans->buf_size;
> +	pr_debug("%s: trans->buf_alloc=%lld\n", __func__, trans->buf_alloc);
> +
> +	mutex_init(&trans->rx_lock);
> +	mutex_init(&trans->tx_lock);
> +	INIT_LIST_HEAD(&trans->rx_queue);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
> +
> +u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	return trans->buf_size;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_get_buffer_size);
> +
> +u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	return trans->buf_size_min;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_get_min_buffer_size);
> +
> +u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	return trans->buf_size_max;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_get_max_buffer_size);
> +
> +void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	if (val < trans->buf_size_min)
> +		trans->buf_size_min = val;
> +	if (val > trans->buf_size_max)
> +		trans->buf_size_max = val;
> +	trans->buf_size = val;
> +	trans->buf_alloc = val;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
> +
> +void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	if (val > trans->buf_size)
> +		trans->buf_size = val;
> +	trans->buf_size_min = val;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_set_min_buffer_size);
> +
> +void virtio_transport_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	if (val < trans->buf_size)
> +		trans->buf_size = val;
> +	trans->buf_size_max = val;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_set_max_buffer_size);
> +
> +int
> +virtio_transport_notify_poll_in(struct vsock_sock *vsk,
> +				size_t target,
> +				bool *data_ready_now)
> +{
> +	if (vsock_stream_has_data(vsk))
> +		*data_ready_now = true;
> +	else
> +		*data_ready_now = false;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
> +
> +int
> +virtio_transport_notify_poll_out(struct vsock_sock *vsk,
> +				 size_t target,
> +				 bool *space_avail_now)
> +{
> +	s64 free_space;
> +
> +	free_space = vsock_stream_has_space(vsk);
> +	if (free_space > 0)
> +		*space_avail_now = true;
> +	else if (free_space == 0)
> +		*space_avail_now = false;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
> +
> +int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
> +
> +int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
> +
> +int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
> +	size_t target, struct vsock_transport_recv_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
> +
> +int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
> +	size_t target, ssize_t copied, bool data_read,
> +	struct vsock_transport_recv_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
> +
> +int virtio_transport_notify_send_init(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
> +
> +int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
> +
> +int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
> +	struct vsock_transport_send_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
> +
> +int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
> +	ssize_t written, struct vsock_transport_send_notify_data *data)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
> +
> +u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	return trans->buf_size;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
> +
> +bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
> +{
> +	return true;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
> +
> +bool virtio_transport_stream_allow(u32 cid, u32 port)
> +{
> +	return true;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
> +
> +int virtio_transport_dgram_bind(struct vsock_sock *vsk,
> +				struct sockaddr_vm *addr)
> +{
> +	return vsock_bind_dgram_generic(vsk, addr);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
> +
> +bool virtio_transport_dgram_allow(u32 cid, u32 port)
> +{
> +	return true;
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
> +
> +int virtio_transport_connect(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_REQUEST,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s: vsk=%p send_request\n", __func__, vsk);
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_connect);
> +
> +int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_SHUTDOWN,
> +		.type = SOCK_STREAM,
> +		.shut = mode,
> +	};
> +
> +	pr_debug("%s: vsk=%p: send_shutdown\n", __func__, vsk);
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
> +
> +void virtio_transport_release(struct vsock_sock *vsk)
> +{
> +	pr_debug("%s: vsk=%p\n", __func__, vsk);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_release);
> +
> +int
> +virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
> +			       struct sockaddr_vm *remote_addr,
> +			       struct iovec *iov,
> +			       size_t len)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_RW,
> +		.type = SOCK_DGRAM,
> +		.iov = iov,
> +		.len = len,
> +	};
> +
> +	vsk->remote_addr = *remote_addr;
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
> +
> +ssize_t
> +virtio_transport_stream_enqueue(struct vsock_sock *vsk,
> +				struct iovec *iov,
> +				size_t len)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_RW,
> +		.type = SOCK_STREAM,
> +		.iov = iov,
> +		.len = len,
> +	};
> +
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
> +
> +void virtio_transport_destruct(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +
> +	pr_debug("%s: vsk=%p\n", __func__, vsk);
> +	kfree(trans);
> +}
> +EXPORT_SYMBOL_GPL(virtio_transport_destruct);
> +
> +static int virtio_transport_send_attach(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_ATTACH,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s: vsk=%p send_attach\n", __func__, vsk);
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +
> +static int virtio_transport_send_offer(struct vsock_sock *vsk)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_OFFER,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s: sk=%p send_offer\n", __func__, vsk);
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +
> +static int virtio_transport_send_reset(struct vsock_sock *vsk,
> +				       struct virtio_vsock_pkt *pkt)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_RST,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s\n", __func__);
> +
> +	/* Send RST only if the original pkt is not a RST pkt */
> +	if (pkt->hdr.op == VIRTIO_VSOCK_OP_RST)
> +		return 0;
> +
> +	return trans->ops->send_pkt(vsk, &info);
> +}
> +
> +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;
> +
> +	pr_debug("%s: vsk=%p\n", __func__, vsk);
> +	switch (pkt->hdr.op) {
> +	case VIRTIO_VSOCK_OP_ATTACH:
> +		pr_debug("%s: got attach\n", __func__);
> +		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_NEGOTIATE:
> +		pr_debug("%s: got negotiate and send_offer\n", __func__);
> +		err = virtio_transport_send_offer(vsk);
> +		if (err < 0) {
> +			skerr = -err;
> +			goto destroy;
> +		}
> +		break;
> +	case VIRTIO_VSOCK_OP_INVALID:
> +		pr_debug("%s: got invalid\n", __func__);
> +		break;
> +	case VIRTIO_VSOCK_OP_RST:
> +		pr_debug("%s: got rst\n", __func__);
> +		skerr = ECONNRESET;
> +		err = 0;
> +		goto destroy;
> +	default:
> +		pr_debug("%s: got def\n", __func__);
> +		skerr = EPROTO;
> +		err = -EINVAL;
> +		goto destroy;
> +	}
> +	return 0;
> +
> +destroy:
> +	virtio_transport_send_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_transport *trans = vsk->trans;
> +	int err = 0;
> +
> +	switch (pkt->hdr.op) {
> +	case VIRTIO_VSOCK_OP_RW:
> +		pkt->len = pkt->hdr.len;
> +		pkt->off = 0;
> +		pkt->trans = trans;
> +
> +		mutex_lock(&trans->rx_lock);
> +		virtio_transport_inc_rx_pkt(pkt);
> +		list_add_tail(&pkt->list, &trans->rx_queue);
> +		mutex_unlock(&trans->rx_lock);
> +
> +		sk->sk_data_ready(sk, pkt->len);
> +		return err;
> +	case VIRTIO_VSOCK_OP_CREDIT:
> +		sk->sk_write_space(sk);
> +		break;
> +	case VIRTIO_VSOCK_OP_SHUTDOWN:
> +		pr_debug("%s: got shutdown\n", __func__);
> +		if (pkt->hdr.shut) {
> +			vsk->peer_shutdown |= pkt->hdr.shut;
> +			sk->sk_state_change(sk);
> +		}
> +		break;
> +	case VIRTIO_VSOCK_OP_RST:
> +		pr_debug("%s: got rst\n", __func__);
> +		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);
> +		break;
> +	default:
> +		err = -EINVAL;
> +		break;
> +	}
> +
> +	virtio_transport_free_pkt(pkt);
> +	return err;
> +}
> +
> +static int
> +virtio_transport_send_negotiate(struct vsock_sock *vsk,
> +				struct virtio_vsock_pkt *pkt)
> +{
> +	struct virtio_transport *trans = vsk->trans;
> +	struct virtio_vsock_pkt_info info = {
> +		.op = VIRTIO_VSOCK_OP_NEGOTIATE,
> +		.type = SOCK_STREAM,
> +	};
> +
> +	pr_debug("%s: send_negotiate\n", __func__);
> +
> +	return trans->ops->send_pkt(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 *vpending;
> +	struct sock *pending;
> +	int err;
> +
> +	pending = virtio_transport_get_pending(sk, pkt);
> +	if (pending) {
> +		pr_debug("virtio_transport_recv_listen: get pending\n");
> +		vpending = vsock_sk(pending);
> +		lock_sock(pending);
> +		switch (pending->sk_state) {
> +		case SS_CONNECTING:
> +			if (pkt->hdr.op != VIRTIO_VSOCK_OP_OFFER) {
> +				pr_debug("%s: != OP_OFFER op=%d\n",
> +					 __func__, pkt->hdr.op);
> +				virtio_transport_send_reset(vpending, pkt);
> +				pending->sk_err = EPROTO;
> +				pending->sk_state = SS_UNCONNECTED;
> +				sock_put(pending);
> +			} else {
> +				pending->sk_state = SS_CONNECTED;
> +				vsock_insert_connected(vpending);
> +
> +				vsock_remove_pending(sk, pending);
> +				vsock_enqueue_accept(sk, pending);
> +
> +				virtio_transport_send_attach(vpending);
> +				sk->sk_state_change(sk);
> +			}
> +			err = 0;
> +			break;
> +		default:
> +			pr_debug("%s: sk->sk_ack_backlog=%d\n", __func__,
> +				 sk->sk_ack_backlog);
> +			virtio_transport_send_reset(vpending, pkt);
> +			err = -EINVAL;
> +			break;
> +		}
> +		if (err < 0)
> +			vsock_remove_pending(sk, pending);
> +		release_sock(pending);
> +
> +		/* Release refcnt obtained in virtio_transport_get_pending */
> +		sock_put(pending);
> +
> +		return err;
> +	}
> +
> +	if (pkt->hdr.op != VIRTIO_VSOCK_OP_REQUEST) {
> +		virtio_transport_send_reset(vsk, pkt);
> +		pr_debug("%s:op != OP_REQUEST op = %d\n",
> +			 __func__, pkt->hdr.op);
> +		return -EINVAL;
> +	}
> +
> +	if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) {
> +		pr_debug("%s: sk->sk_ack_backlog=%d\n", __func__,
> +			 sk->sk_ack_backlog);
> +		virtio_transport_send_reset(vsk, pkt);
> +		return -ECONNREFUSED;
> +	}
> +
> +	/* So no pending socket are responsible for this pkt, create one */
> +	pending = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
> +				 sk->sk_type);
> +	if (!pending) {
> +		virtio_transport_send_reset(vsk, pkt);
> +		return -ENOMEM;
> +	}
> +	pr_debug("virtio_transport_recv_listen: create pending\n");
> +
> +	vpending = vsock_sk(pending);
> +	vsock_addr_init(&vpending->local_addr, pkt->hdr.dst_cid,
> +			pkt->hdr.dst_port);
> +	vsock_addr_init(&vpending->remote_addr, pkt->hdr.src_cid,
> +			pkt->hdr.src_port);
> +
> +	vsock_add_pending(sk, pending);
> +
> +	err = virtio_transport_send_negotiate(vpending, pkt);
> +	if (err < 0) {
> +		virtio_transport_send_reset(vsk, pkt);
> +		sock_put(pending);
> +		return err;
> +	}
> +
> +	sk->sk_ack_backlog++;
> +
> +	pending->sk_state = SS_CONNECTING;
> +
> +	/* Clean up in case no further message is received for this socket */
> +	vpending->listener = sk;
> +	sock_hold(sk);
> +	sock_hold(pending);
> +	INIT_DELAYED_WORK(&vpending->dwork, vsock_pending_work);
> +	schedule_delayed_work(&vpending->dwork, HZ);
> +
> +	return 0;
> +}
> +
> +void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
> +{
> +	struct virtio_transport *trans;
> +	struct sockaddr_vm src, dst;
> +	struct vsock_sock *vsk;
> +	struct sock *sk;
> +
> +	vsock_addr_init(&src, pkt->hdr.src_cid, pkt->hdr.src_port);
> +	vsock_addr_init(&dst, pkt->hdr.dst_cid, pkt->hdr.dst_port);
> +
> +	virtio_vsock_dumppkt(__func__, pkt);
> +
> +	if (pkt->hdr.type == SOCK_DGRAM) {
> +		sk = vsock_find_unbound_socket(&dst);
> +		if (!sk)
> +			goto free_pkt;
> +		return virtio_transport_recv_dgram(sk, 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) {
> +			pr_debug("%s: can not find bound_socket\n", __func__);
> +			virtio_vsock_dumppkt(__func__, pkt);
> +			/* Ignore this pkt instead of sending reset back */
> +			goto free_pkt;
> +		}
> +	}
> +
> +	vsk = vsock_sk(sk);
> +	trans = vsk->trans;
> +	BUG_ON(!trans);
> +
> +	mutex_lock(&trans->tx_lock);
> +	trans->peer_buf_alloc = pkt->hdr.buf_alloc;
> +	trans->peer_fwd_cnt = pkt->hdr.fwd_cnt;
> +	if (__virtio_transport_stream_has_space(vsk))
> +		sk->sk_write_space(sk);
> +	mutex_unlock(&trans->tx_lock);
> +
> +	lock_sock(sk);
> +	switch (sk->sk_state) {
> +	case 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;
> +	default:
> +		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);
> +
> +static int __init virtio_vsock_common_init(void)
> +{
> +	return 0;
> +}
> +
> +static void __exit virtio_vsock_common_exit(void)
> +{
> +}
> +
> +module_init(virtio_vsock_common_init);
> +module_exit(virtio_vsock_common_exit);
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Asias He");
> +MODULE_DESCRIPTION("common code for virtio vsock");
> -- 
> 1.8.1.4