Hi Ben,
Thank you for your reply! I am newbie to openflow development, please
pardon me if my problem description is not precise :)
Could you please point me to the gre tunnel processing file, I would
like to take a look to understand it better.
Thanks!
Yimin
On Tue, May 8, 2012 at 12:16 AM, Ben Pfaff <b...@nicira.com> wrote:
> With the normal way that gre tunnel processing works, you only get a
> shot at it after decap.
>
> Or maybe you're just describing the way that GRE tunnel processing
> works and don't need resubmit at all. It's hard to tell, since you
> keep changing your description and your requirements.
>
> On Mon, May 07, 2012 at 08:55:36AM +0800, YIMIN CHEN wrote:
>> I didn't quite yet understand why resubmit does not work for my case.
>> It could be the same flow table, I just need to search it twice:
>> -- once before decap, when hit, knows the flow needs to be decap'ed
>> and resubmitted to the table again
>> -- once after decap, with the destination IP of decap'ed packet.
>>
>> This does not work?
>>
>>
>> Thanks!
>>
>> On Sat, May 5, 2012 at 3:40 AM, Ben Pfaff <b...@nicira.com> wrote:
>> > The difference is that Yimin Chen wants to process the packet through
>> > two flow tables, one before and one after decap. With the normal way
>> > that gre tunnel processing works, you only get a shot at it after
>> > decap.
>> >
>> > On Fri, May 04, 2012 at 12:35:00PM -0700, Karl Yang wrote:
>> >> what is the difference between your this case and the "gre" tunnel
>> >> processing case within data path code?
>> >>
>> >> On Fri, May 4, 2012 at 10:05 AM, Ben Pfaff <b...@nicira.com> wrote:
>> >>
>> >> > No.
>> >> >
>> >> > On Fri, May 04, 2012 at 10:16:14AM +0800, YIMIN CHEN wrote:
>> >> > > Hi Ben,
>> >> > >
>> >> > > My goal is to implement a decap action that would decap a packet with
>> >> > > external IP addresses, and then have the decapped packet, with
>> >> > > internal IP addresses, do a flow lookup again.
>> >> > >
>> >> > > Can this be achieved using resubmit?
>> >> > >
>> >> > > Thanks!
>> >> > > Yimin
>> >> > >
>> >> > > On Fri, May 4, 2012 at 9:37 AM, Ben Pfaff <b...@nicira.com> wrote:
>> >> > > > You can read PORTING in the root of the tree.
>> >> > > >
>> >> > > > It would be best if you'd explain your goal first, instead of doing
>> >> > > > a
>> >> > > > deep dive into implementation details.
>> >> > > >
>> >> > > > On Fri, May 04, 2012 at 09:20:38AM +0800, YIMIN CHEN wrote:
>> >> > > >> Hi Ben,
>> >> > > >>
>> >> > > >> Thank you for the detailed information! I read this part of the
>> >> > > >> code,
>> >> > > >> and have some confusion. Can you please review the following to
>> >> > > >> see if
>> >> > > >> my understanding of code is correct?
>> >> > > >>
>> >> > > >> 1) ofproto/ code is userspace code, and datapath/ code is the
>> >> > > >> actual
>> >> > dp code.
>> >> > > >> 2) ofproto handles the rule insertion from control plane, and
>> >> > > >> datapath
>> >> > > >> handles the actual flow lookup.
>> >> > > >> 3) resubmit is handled in userspace? I saw the resubmit logic
>> >> > > >> xlate_nicira_action() is in ofproto I didn't see find any code in
>> >> > > >> datapath that handles resubmit, not even in ovs-ofctl.c. Is
>> >> > > >> xlate_nicira_action() doing flow insertion with resubmit action or
>> >> > > >> actually performing the dp actions? I am confused.
>> >> > > >>
>> >> > > >> What is the relationship between ofproto userspace and the dp code?
>> >> > > >> what is the difference between xlate table action and odp action?
>> >> > > >>
>> >> > > >> I think I am very confused, if there is any documentation I can
>> >> > > >> read
>> >> > > >> to understand this design better, would you please give me a
>> >> > > >> pointer?
>> >> > > >>
>> >> > > >> Thanks!
>> >> > > >> Yimin
>> >> > > >>
>> >> > > >> On Thu, May 3, 2012 at 11:30 AM, Ben Pfaff <b...@nicira.com> wrote:
>> >> > > >> > It's documented in nicira-ext.h:
>> >> > > >> >
>> >> > > >> > /* Action structures for NXAST_RESUBMIT and NXAST_RESUBMIT_TABLE.
>> >> > > >> > *
>> >> > > >> > * These actions search one of the switch's flow tables:
>> >> > > >> > *
>> >> > > >> > * - For NXAST_RESUBMIT_TABLE only, if the 'table' member is
>> >> > > >> > not
>> >> > 255, then
>> >> > > >> > * it specifies the table to search.
>> >> > > >> > *
>> >> > > >> > * - Otherwise (for NXAST_RESUBMIT_TABLE with a 'table' of
>> >> > > >> > 255,
>> >> > or for
>> >> > > >> > * NXAST_RESUBMIT regardless of 'table'), it searches the
>> >> > current flow
>> >> > > >> > * table, that is, the OpenFlow flow table that contains the
>> >> > flow from
>> >> > > >> > * which this action was obtained. If this action did not
>> >> > come from a
>> >> > > >> > * flow table (e.g. it came from an OFPT_PACKET_OUT
>> >> > > >> > message),
>> >> > then table 0
>> >> > > >> > * is the current table.
>> >> > > >> > *
>> >> > > >> > * The flow table lookup uses a flow that may be slightly
>> >> > > >> > modified
>> >> > from the
>> >> > > >> > * original lookup:
>> >> > > >> > *
>> >> > > >> > * - For NXAST_RESUBMIT, the 'in_port' member of struct
>> >> > nx_action_resubmit
>> >> > > >> > * is used as the flow's in_port.
>> >> > > >> > *
>> >> > > >> > * - For NXAST_RESUBMIT_TABLE, if the 'in_port' member is not
>> >> > OFPP_IN_PORT,
>> >> > > >> > * then its value is used as the flow's in_port. Otherwise,
>> >> > the original
>> >> > > >> > * in_port is used.
>> >> > > >> > *
>> >> > > >> > * - If actions that modify the flow (e.g. OFPAT_SET_VLAN_VID)
>> >> > precede the
>> >> > > >> > * resubmit action, then the flow is updated with the new
>> >> > values.
>> >> > > >> > *
>> >> > > >> > * Following the lookup, the original in_port is restored.
>> >> > > >> > *
>> >> > > >> > * If the modified flow matched in the flow table, then the
>> >> > corresponding
>> >> > > >> > * actions are executed. Afterward, actions following the
>> >> > > >> > resubmit
>> >> > in the
>> >> > > >> > * original set of actions, if any, are executed; any changes
>> >> > > >> > made
>> >> > to the
>> >> > > >> > * packet (e.g. changes to VLAN) by secondary actions persist
>> >> > > >> > when
>> >> > those
>> >> > > >> > * actions are executed, although the original in_port is
>> >> > > >> > restored.
>> >> > > >> > *
>> >> > > >> > * Resubmit actions may be used any number of times within a set
>> >> > > >> > of
>> >> > actions.
>> >> > > >> > *
>> >> > > >> > * Resubmit actions may nest to an implementation-defined depth.
>> >> > Beyond this
>> >> > > >> > * implementation-defined depth, further resubmit actions are
>> >> > simply ignored.
>> >> > > >> > *
>> >> > > >> > * NXAST_RESUBMIT ignores 'table' and 'pad'.
>> >> > > >> > NXAST_RESUBMIT_TABLE
>> >> > requires
>> >> > > >> > * 'pad' to be all-bits-zero.
>> >> > > >> > *
>> >> > > >> > * Open vSwitch 1.0.1 and earlier did not support recursion.
>> >> > > >> > Open
>> >> > vSwitch
>> >> > > >> > * before 1.2.90 did not support NXAST_RESUBMIT_TABLE.
>> >> > > >> > */
>> >> > > >> > struct nx_action_resubmit {
>> >> > > >> > ovs_be16 type; /* OFPAT_VENDOR. */
>> >> > > >> > ovs_be16 len; /* Length is 16. */
>> >> > > >> > ovs_be32 vendor; /* NX_VENDOR_ID. */
>> >> > > >> > ovs_be16 subtype; /* NXAST_RESUBMIT. */
>> >> > > >> > ovs_be16 in_port; /* New in_port for checking
>> >> > > >> > flow
>> >> > table. */
>> >> > > >> > uint8_t table; /* NXAST_RESUBMIT_TABLE: table
>> >> > to use. */
>> >> > > >> > uint8_t pad[3];
>> >> > > >> > };
>> >> > > >> > OFP_ASSERT(sizeof(struct nx_action_resubmit) == 16);
>> >> > > >> >
>> >> > > >> > and in ovs-ofctl(8):
>> >> > > >> >
>> >> > > >> > resubmit:port
>> >> > > >> > resubmit([port],[table])
>> >> > > >> > Re-searches this OpenFlow flow table (or the
>> >> > table whose
>> >> > > >> > number is specified by table) with the
>> >> > in_port field
>> >> > > >> > replaced by port (if port is specified) and
>> >> > executes the
>> >> > > >> > actions found, if any, in addition to any
>> >> > other actions
>> >> > > >> > in this flow entry.
>> >> > > >> >
>> >> > > >> > Recursive resubmit actions are obeyed up to
>> >> > > >> > an
>> >> > implemen‐
>> >> > > >> > tation-defined maximum depth. Open vSwitch
>> >> > 1.0.1 and
>> >> > > >> > earlier did not support recursion; Open
>> >> > vSwitch before
>> >> > > >> > 1.2.90 did not support table.
>> >> > > >> >
>> >> > > >> >
>> >> > > >> > On Thu, May 03, 2012 at 09:54:08AM +0800, YIMIN CHEN wrote:
>> >> > > >> >> Hi Ben,
>> >> > > >> >>
>> >> > > >> >> Thank you for your reply! I saw there is some code about
>> >> > > >> >> resubmit
>> >> > > >> >> Nicira extension action, but that seems to be in userspace
>> >> > ofproto.c,
>> >> > > >> >> not in datapath, so I didn't know that is related. Could you
>> >> > > >> >> help
>> >> > > >> >> clarify for me how does resubmit work?
>> >> > > >> >>
>> >> > > >> >>
>> >> > > >> >> Thanks!
>> >> > > >> >> Yimin
>> >> > > >> >>
>> >> > > >> >> On Wed, May 2, 2012 at 12:40 PM, Ben Pfaff <b...@nicira.com>
>> >> > > >> >> wrote:
>> >> > > >> >> > On Wed, May 02, 2012 at 10:53:10AM +0800, YIMIN CHEN wrote:
>> >> > > >> >> >> I am looking at ovs dp code, and is looking at a correct way
>> >> > for a
>> >> > > >> >> >> flow to traverse the table twice. The goal is like this:
>> >> > > >> >> >>
>> >> > > >> >> >> flow lookup => tbl_lookup()
>> >> > > >> >> >> perform actions => execute_actions() which changes the packet
>> >> > > >> >> >> flow lookup using the new packet => tbl_lookup()
>> >> > > >> >> >> perform actions on the new packet => execute_actions.
>> >> > > >> >> >
>> >> > > >> >> > Do you want the "resubmit" Nicira extension action?
>> >> > _______________________________________________
>> >> > dev mailing list
>> >> > dev@openvswitch.org
>> >> > http://openvswitch.org/mailman/listinfo/dev
>> >> >
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