On 07/31/2015 12:13 PM, Yang Hongyang wrote:
> This filter is to buffer/release packets, this feature can be used
> when using MicroCheckpointing, or other Remus like VM FT solutions, you
> can also use it to simulate the network delay.
> It has an interval option, if supplied, this filter will release
> packets by interval.
>
> Usage:
> -netdev tap,id=bn0
> -netfilter buffer,id=f0,netdev=bn0,chain=in,interval=1000
>
> NOTE:
> the scale of interval is microsecond.
>
> Signed-off-by: Yang Hongyang <yan...@cn.fujitsu.com>
> ---
> net/Makefile.objs | 1 +
> net/filter-buffer.c | 160
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> net/filter.c | 2 +
> net/filters.h | 17 ++++++
> qapi-schema.json | 18 +++++-
> 5 files changed, 197 insertions(+), 1 deletion(-)
> create mode 100644 net/filter-buffer.c
> create mode 100644 net/filters.h
>
> diff --git a/net/Makefile.objs b/net/Makefile.objs
> index 914aec0..5fa2f97 100644
> --- a/net/Makefile.objs
> +++ b/net/Makefile.objs
> @@ -14,3 +14,4 @@ common-obj-$(CONFIG_SLIRP) += slirp.o
> common-obj-$(CONFIG_VDE) += vde.o
> common-obj-$(CONFIG_NETMAP) += netmap.o
> common-obj-y += filter.o
> +common-obj-y += filter-buffer.o
> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
> new file mode 100644
> index 0000000..7f2b050
> --- /dev/null
> +++ b/net/filter-buffer.c
> @@ -0,0 +1,160 @@
> +/*
> + * Copyright (c) 2015 FUJITSU LIMITED
> + * Author: Yang Hongyang <yan...@cn.fujitsu.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * later. See the COPYING file in the top-level directory.
> + */
> +
> +#include "net/filter.h"
> +#include "net/queue.h"
> +#include "filters.h"
> +#include "qemu-common.h"
> +#include "qemu/error-report.h"
> +#include "qemu/main-loop.h"
> +#include "qemu/timer.h"
> +#include "qemu/iov.h"
> +
> +typedef struct FILTERBUFFERState {
> + NetFilterState nf;
> + NetQueue *incoming_queue;
> + NetQueue *inflight_queue;
> + QEMUBH *flush_bh;
> + int64_t interval;
> + QEMUTimer release_timer;
> +} FILTERBUFFERState;
> +
> +static void packet_send_completed(NetClientState *nc, ssize_t len)
> +{
> + return;
> +}
> +
> +static void filter_buffer_flush(NetFilterState *nf)
> +{
> + FILTERBUFFERState *s = DO_UPCAST(FILTERBUFFERState, nf, nf);
> + NetQueue *queue = s->inflight_queue;
> + NetPacket *packet;
> +
> + while (queue && !QTAILQ_EMPTY(&queue->packets)) {
> + packet = QTAILQ_FIRST(&queue->packets);
> + QTAILQ_REMOVE(&queue->packets, packet, entry);
> + queue->nq_count--;
> +
> + qemu_net_queue_send(packet->sender->peer->incoming_queue,
> + packet->sender,
> + packet->flags,
> + packet->data,
> + packet->size,
> + packet->sent_cb);
Need to check peer since it may be NULL e.g after it was deleted. And we
probably need to queue the packet into next filter.
