RE: [PATCH V4 1/7] qapi/net.json: Add IP_PROTOCOL definition

From: "Zhang, Chen" <chen.zhang@intel.com>
To: Markus Armbruster <armbru@redhat.com>
Cc: Lukas Straub <lukasstraub2@web.de>,
	Li Zhijian <lizhijian@cn.fujitsu.com>,
	Jason Wang <jasowang@redhat.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	qemu-dev <qemu-devel@nongnu.org>,
	Zhang Chen <zhangckid@gmail.com>
Subject: RE: [PATCH V4 1/7] qapi/net.json: Add IP_PROTOCOL definition
Date: Fri, 16 Apr 2021 06:03:53 +0000	[thread overview]
Message-ID: <e3d3a24a770f4dada58159ece42da330@intel.com> (raw)
In-Reply-To: <87czuvbmvi.fsf@dusky.pond.sub.org>

> -----Original Message-----
> From: Markus Armbruster <armbru@redhat.com>
> Sent: Thursday, April 15, 2021 11:15 PM
> To: Zhang, Chen <chen.zhang@intel.com>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>; Lukas Straub
> <lukasstraub2@web.de>; Li Zhijian <lizhijian@cn.fujitsu.com>; Jason Wang
> <jasowang@redhat.com>; qemu-dev <qemu-devel@nongnu.org>; Zhang
> Chen <zhangckid@gmail.com>
> Subject: Re: [PATCH V4 1/7] qapi/net.json: Add IP_PROTOCOL definition
> 
> "Zhang, Chen" <chen.zhang@intel.com> writes:
> 
> >> -----Original Message-----
> >> From: Qemu-devel <qemu-devel-
> >> bounces+chen.zhang=intel.com@nongnu.org> On Behalf Of Dr. David
> Alan
> >> Gilbert
> >> Sent: Wednesday, March 24, 2021 4:01 AM
> >> To: Zhang, Chen <chen.zhang@intel.com>
> >> Cc: Lukas Straub <lukasstraub2@web.de>; Li Zhijian
> >> <lizhijian@cn.fujitsu.com>; Jason Wang <jasowang@redhat.com>; qemu-
> >> dev <qemu-devel@nongnu.org>; Markus Armbruster
> <armbru@redhat.com>;
> >> Zhang Chen <zhangckid@gmail.com>
> >> Subject: Re: [PATCH V4 1/7] qapi/net.json: Add IP_PROTOCOL definition
> >>
> >> * Zhang Chen (chen.zhang@intel.com) wrote:
> >> > Add IP_PROTOCOL as enum include TCP,UDP, ICMP... for other QMP
> >> commands.
> >> >
> >> > Signed-off-by: Zhang Chen <chen.zhang@intel.com>
> >> > ---
> >> >  qapi/net.json | 31 +++++++++++++++++++++++++++++++
> >> >  1 file changed, 31 insertions(+)
> >> >
> >> > diff --git a/qapi/net.json b/qapi/net.json index
> >> > 87361ebd9a..498ea7aa72 100644
> >> > --- a/qapi/net.json
> >> > +++ b/qapi/net.json
> >> > @@ -794,3 +794,34 @@
> >> >  #
> >> >  ##
> >> >  { 'command': 'query-netdev', 'returns': ['NetdevInfo'] }
> >> > +
> >> > +##
> >> > +# @IP_PROTOCOL:
> >> > +#
> >> > +# Transport layer protocol.
> >> > +#
> >> > +# Just for IPv4.
> >> > +#
> >> > +# @tcp: Transmission Control Protocol.
> >> > +#
> >> > +# @udp: User Datagram Protocol.
> >> > +#
> >> > +# @dccp: Datagram Congestion Control Protocol.
> >> > +#
> >> > +# @sctp: Stream Control Transmission Protocol.
> >> > +#
> >> > +# @udplite: Lightweight User Datagram Protocol.
> >> > +#
> >> > +# @icmp: Internet Control Message Protocol.
> >> > +#
> >> > +# @igmp: Internet Group Management Protocol.
> >> > +#
> >> > +# @ipv6: IPv6 Encapsulation.
> >> > +#
> >> > +# TODO: Need to add more transport layer protocol.
> >> > +#
> >> > +# Since: 6.1
> >> > +##
> >> > +{ 'enum': 'IP_PROTOCOL', 'data': [ 'tcp', 'udp', 'dccp', 'sctp', 'udplite',
> >> > +    'icmp', 'igmp', 'ipv6' ] }
> >>
> >> Isn't the right thing to do here to use a string for protocol and
> >> then pass it to getprotobyname;  that way your list is never out of
> >> date, and you never have to translate between the order of this enum
> >> and the integer assignment set in stone.
> >>
> >
> > Hi Dave,
> >
> > Considering that most of the scenes in Qemu don't call the
> getprotobyname, looks keep the string are more readable.
> 
> Unless I'm missing something,
> 
> (1) this enum is only used for matching packets by source IP, source port,
> destination IP, destination port, and protocol, and
> 
> (2) the packet matching works just fine for *any* protocol.
> 
> By using an enum for the protocol, you're limiting the matcher to whatever
> protocols we bother to include in the enum for no particular reason.  Feels
> wrong to me.

Should we remove the IP_PROTOCOL enum here? Make user input string protocol name for this field?
Or any other detailed comments here?

Thanks
Chen

> 
> > Please review the V5 patches, Thanks.
> >
> > Thanks
> > Chen
> >
> >> Dave
> >>
> >> > +
> >> > --
> >> > 2.25.1
> >> >
> >> --
> >> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> >>