> -----Original Message-----
> From: Lukas Straub [mailto:lukasstra...@web.de]
> Sent: Friday, August 16, 2019 2:49 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zh...@intel.com>; Jason Wang
> <jasow...@redhat.com>; Wen Congyang <wencongya...@huawei.com>; Xie
> Changlong <xiechanglon...@gmail.com>
> Subject: [PATCH v2 2/3] net/filter.c: Add Options to insert filters anywhere
> in
> the filter list
>
> To switch the Secondary to Primary, we need to insert new filters before the
> filter-rewriter.
>
> Add the options insert= and position= to be able to insert filters anywhere
> in the
> filter list.
>
> position should be either "head", "tail" or the id of another filter.
> insert should be either "before" or "after" to specify where to insert the new
> filter relative to the one specified with position.
>
Hi Lukas,
It looks no need to add the "insert = xxx" for this operation.
For example:
We have 3 net-filters, the running order like that:
Fiter1 ----------> Filter2 ------------> Filter3
If we want to add another filter between filter1 and filter2.
The "Position = head, insert = after" always seam with "position = filter2 id,
insert = before". It seems the "insert" is a redundant args.
So I think it is enough with the "position", we can make the "insert" always
equal "after" except the "head".
Thanks
Zhang Chen
> Signed-off-by: Lukas Straub <lukasstra...@web.de>
> ---
> include/net/filter.h | 2 ++
> net/filter.c | 71 +++++++++++++++++++++++++++++++++++++++++++-
> qemu-options.hx | 10 +++----
> 3 files changed, 77 insertions(+), 6 deletions(-)
>
> diff --git a/include/net/filter.h b/include/net/filter.h index
> 49da666ac0..355c178f75 100644
> --- a/include/net/filter.h
> +++ b/include/net/filter.h
> @@ -62,6 +62,8 @@ struct NetFilterState {
> NetClientState *netdev;
> NetFilterDirection direction;
> bool on;
> + char *position;
> + bool insert_before;
> QTAILQ_ENTRY(NetFilterState) next;
> };
>
> diff --git a/net/filter.c b/net/filter.c index 28d1930db7..309fd778df 100644
> --- a/net/filter.c
> +++ b/net/filter.c
> @@ -171,11 +171,47 @@ static void netfilter_set_status(Object *obj, const
> char *str, Error **errp)
> }
> }
>
> +static char *netfilter_get_position(Object *obj, Error **errp) {
> + NetFilterState *nf = NETFILTER(obj);
> +
> + return g_strdup(nf->position);
> +}
> +
> +static void netfilter_set_position(Object *obj, const char *str, Error
> +**errp) {
> + NetFilterState *nf = NETFILTER(obj);
> +
> + nf->position = g_strdup(str);
> +}
> +
> +static char *netfilter_get_insert(Object *obj, Error **errp) {
> + NetFilterState *nf = NETFILTER(obj);
> +
> + return nf->insert_before ? g_strdup("before") : g_strdup("after");
> +}
> +
> +static void netfilter_set_insert(Object *obj, const char *str, Error
> +**errp) {
> + NetFilterState *nf = NETFILTER(obj);
> +
> + if (strcmp(str, "before") && strcmp(str, "after")) {
> + error_setg(errp, "Invalid value for netfilter insert, "
> + "should be 'head' or 'tail'");
> + return;
> + }
> +
> + nf->insert_before = !strcmp(str, "before"); }
> +
> static void netfilter_init(Object *obj) {
> NetFilterState *nf = NETFILTER(obj);
>
> nf->on = true;
> + nf->insert_before = false;
> + nf->position = g_strdup("tail");
>
> object_property_add_str(obj, "netdev",
> netfilter_get_netdev_id,
> netfilter_set_netdev_id, @@ -187,11
> +223,18 @@ static void netfilter_init(Object *obj)
> object_property_add_str(obj, "status",
> netfilter_get_status, netfilter_set_status,
> NULL);
> + object_property_add_str(obj, "position",
> + netfilter_get_position, netfilter_set_position,
> + NULL);
> + object_property_add_str(obj, "insert",
> + netfilter_get_insert, netfilter_set_insert,
> + NULL);
> }
>
> static void netfilter_complete(UserCreatable *uc, Error **errp) {
> NetFilterState *nf = NETFILTER(uc);
> + NetFilterState *position = NULL;
> NetClientState *ncs[MAX_QUEUE_NUM];
> NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
> int queues;
> @@ -219,6 +262,20 @@ static void netfilter_complete(UserCreatable *uc,
> Error **errp)
> return;
> }
>
> + if (strcmp(nf->position, "head") && strcmp(nf->position, "tail")) {
> + /* Search for the position to insert before/after */
> + Object *container;
> + Object *obj;
> +
> + container = object_get_objects_root();
> + obj = object_resolve_path_component(container, nf->position);
> + if (!obj) {
> + error_setg(errp, "filter '%s' not found", nf->position);
> + return;
> + }
> + position = NETFILTER(obj);
> + }
> +
> nf->netdev = ncs[0];
>
> if (nfc->setup) {
> @@ -228,7 +285,18 @@ static void netfilter_complete(UserCreatable *uc,
> Error **errp)
> return;
> }
> }
> - QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> +
> + if (position) {
> + if (nf->insert_before) {
> + QTAILQ_INSERT_BEFORE(position, nf, next);
> + } else {
> + QTAILQ_INSERT_AFTER(&nf->netdev->filters, position, nf, next);
> + }
> + } else if (!strcmp(nf->position, "head")) {
> + QTAILQ_INSERT_HEAD(&nf->netdev->filters, nf, next);
> + } else if (!strcmp(nf->position, "tail")) {
> + QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> + }
> }
>
> static void netfilter_finalize(Object *obj) @@ -245,6 +313,7 @@ static void
> netfilter_finalize(Object *obj)
> QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
> }
> g_free(nf->netdev_id);
> + g_free(nf->position);
> }
>
> static void default_handle_event(NetFilterState *nf, int event, Error **errp)
> diff --git a/qemu-options.hx b/qemu-options.hx index 08749a3391..f0a47a0746
> 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4368,7 +4368,7 @@ applications, they can do this through this parameter.
> Its format is a gnutls priority string as described at
> @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
>
> -@item -object filter-
> buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|r
> x|tx}][,status=@var{on|off}]
> +@item -object
> +filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue
> +=@var{all|rx|tx}][,status=@var{on|off}][,position=@var{head|tail|id}][,
> +insert=@var{after|before}]
>
> Interval @var{t} can't be 0, this filter batches the packet delivery: all
> packets
> arriving in a given interval on netdev @var{netdevid} are delayed @@ -4387,11
> +4387,11 @@ queue @var{all|rx|tx} is an option that can be applied to any
> netfilter.
> @option{tx}: the filter is attached to the transmit queue of the netdev,
> where it will receive packets sent by the netdev.
>
> -@item -object filter-
> mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@v
> ar{all|rx|tx}[,vnet_hdr_support]
> +@item -object
> +filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},
> +queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|id}][
> +,insert=@var{after|before}]
>
> filter-mirror on netdev @var{netdevid},mirror net packet to
> chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror
> will
> mirror packet with vnet_hdr_len.
>
> -@item -object filter-
> redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=
> @var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
> +@item -object
> +filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevi
> +d},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][,pos
> +ition=@var{head|tail|id}][,insert=@var{after|before}]
>
> filter-redirector on netdev @var{netdevid},redirect filter's net packet to
> chardev @var{chardevid},and redirect indev's packet to filter.if it has the
> vnet_hdr_support flag, @@ -4400,7 +4400,7 @@ Create a filter-redirector we
> need to differ outdev id from indev id, id can not be the same. we can just
> use
> indev or outdev, but at least one of indev or outdev need to be specified.
>
> -@item -object filter-
> rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_
> support]
> +@item -object
> +filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx}
> +,[vnet_hdr_support][,position=@var{head|tail|id}][,insert=@var{after|be
> +fore}]
>
> Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
> secondary
> from primary to keep secondary tcp connection,and rewrite @@ -4413,7
> +4413,7 @@ colo secondary:
> -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
> -object filter-rewriter,id=rew0,netdev=hn0,queue=all
>
> -@item -object filter-
> dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
> +@item -object
> +filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=
> +@var{len}][,position=@var{head|tail|id}][,insert=@var{after|before}]
>
> Dump the network traffic on netdev @var{dev} to the file specified by
> @var{filename}. At most @var{len} bytes (64k by default) per packet are
> stored.
> --
> 2.20.1