Add support for SRv6 in gRIBI

[cscarpitta]

This pull request introduces a YANG model necessary to support the configuration of SRv6 through gRIBI.

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[robshakir]

Existing tree:

module: gribi-aft
  +--ro afts
     +--ro ipv4-unicast
     |  +--ro ipv4-entry* [prefix]
     |     +--ro prefix    -> ../state/prefix
     |     +--ro state
     |        +--ro prefix?                            oc-inet:ipv4-prefix
     |        +--ro entry-metadata?                    binary
     |        +--ro decapsulate-header?                oc-aftt:encapsulation-header-type
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro ipv6-unicast
     |  +--ro ipv6-entry* [prefix]
     |     +--ro prefix    -> ../state/prefix
     |     +--ro state
     |        +--ro prefix?                            oc-inet:ipv6-prefix
     |        +--ro entry-metadata?                    binary
     |        +--ro decapsulate-header?                oc-aftt:encapsulation-header-type
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro policy-forwarding
     |  +--ro policy-forwarding-entry* [index]
     |     +--ro index    -> ../state/index
     |     +--ro state
     |        +--ro index?                             uint64
     |        +--ro ip-prefix?                         oc-inet:ip-prefix
     |        +--ro mac-address?                       oc-yang:mac-address
     |        +--ro mpls-label?                        oc-mplst:mpls-label
     |        +--ro mpls-tc?                           oc-mplst:mpls-tc
     |        +--ro ip-dscp?                           oc-inet:dscp
     |        +--ro ip-protocol?                       oc-pkt-match-types:ip-protocol-type
     |        +--ro l4-src-port?                       oc-inet:port-number
     |        +--ro l4-dst-port?                       oc-inet:port-number
     |        +--ro entry-metadata?                    binary
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro mpls
     |  +--ro label-entry* [label]
     |     +--ro label    -> ../state/label
     |     +--ro state
     |        +--ro label?                             oc-mplst:mpls-label
     |        +--ro entry-metadata?                    binary
     |        +--ro popped-mpls-label-stack*           oc-mplst:mpls-label
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro ethernet
     |  +--ro mac-entry* [mac-address]
     |     +--ro mac-address    -> ../state/mac-address
     |     +--ro state
     |        +--ro mac-address?                       oc-yang:mac-address
     |        +--ro entry-metadata?                    binary
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro next-hop-groups
     |  +--ro next-hop-group* [id]
     |     +--ro id           -> ../state/id
     |     +--ro state
     |     |  +--ro id?                      uint64
     |     |  +--ro color?                   uint64
     |     |  +--ro backup-next-hop-group?   -> ../../../next-hop-group/state/id
     |     +--ro next-hops
     |        +--ro next-hop* [index]
     |           +--ro index    -> ../state/index
     |           +--ro state
     |              +--ro index?    -> ../../../../../../next-hops/next-hop/state/index
     |              +--ro weight?   uint64
     +--ro next-hops
        +--ro next-hop* [index]
           +--ro index            -> ../state/index
           +--ro state
           |  +--ro index?                     uint64
           |  +--ro ip-address?                oc-inet:ip-address
           |  +--ro mac-address?               oc-yang:mac-address
           |  +--ro pop-top-label?             boolean
           |  +--ro pushed-mpls-label-stack*   oc-mplst:mpls-label
           |  +--ro encapsulate-header?        oc-aftt:encapsulation-header-type
           |  +--ro decapsulate-header?        oc-aftt:encapsulation-header-type
           |  +--ro vni-label?                 oc-evpn-types:evi-id
           |  +--ro tunnel-src-ip-address?     oc-inet:ip-address
           |  +--ro network-instance?          string
           +--ro ip-in-ip
           |  +--ro state
           |     +--ro src-ip?   oc-inet:ip-address
           |     +--ro dst-ip?   oc-inet:ip-address
           +--ro gre
           |  +--ro state
           |     +--ro src-ip?   oc-inet:ip-address
           |     +--ro dst-ip?   oc-inet:ip-address
           |     +--ro ttl?      uint8
           +--ro encap-headers
           |  +--ro encap-header* [index]
           |     +--ro index     -> ../state/index
           |     +--ro state
           |     |  +--ro index?   uint8
           |     |  +--ro type?    oc-aftt:encapsulation-header-type
           |     +--ro gre
           |     |  +--ro state
           |     |     +--ro src-ip?   oc-inet:ip-address
           |     |     +--ro dst-ip?   oc-inet:ip-address
           |     |     +--ro ttl?      uint8
           |     +--ro ipv4
           |     |  +--ro state
           |     |     +--ro src-ip?   oc-inet:ip-address
           |     |     +--ro dst-ip?   oc-inet:ip-address
           |     +--ro ipv6
           |     |  +--ro state
           |     |     +--ro src-ip?   oc-inet:ip-address
           |     |     +--ro dst-ip?   oc-inet:ip-address
           |     +--ro mpls
           |     |  +--ro state
           |     |     +--ro traffic-class?      oc-mplst:mpls-tc
           |     |     +--ro mpls-label-stack*   oc-mplst:mpls-label
           |     +--ro udp-v4
           |     |  +--ro state
           |     |     +--ro src-ip?         oc-inet:ip-address
           |     |     +--ro dst-ip?         oc-inet:ip-address
           |     |     +--ro dscp?           oc-inet:dscp
           |     |     +--ro src-udp-port?   oc-inet:port-number
           |     |     +--ro dst-udp-port?   oc-inet:port-number
           |     |     +--ro ip-ttl?         uint8
           |     +--ro udp-v6
           |        +--ro state
           |           +--ro src-ip?         oc-inet:ip-address
           |           +--ro dst-ip?         oc-inet:ip-address
           |           +--ro dscp?           oc-inet:dscp
           |           +--ro src-udp-port?   oc-inet:port-number
           |           +--ro dst-udp-port?   oc-inet:port-number
           |           +--ro ip-ttl?         uint8
           +--ro interface-ref
              +--ro state
                 +--ro interface?      -> /oc-if:interfaces/interface/name
                 +--ro subinterface?   -> /oc-if:interfaces/interface[oc-if:name=current()/../interface]/subinterfaces/subinterface/index

[robshakir]

Proposed tree:

module: gribi-aft
  +--ro afts
     +--ro ipv4-unicast
     |  +--ro ipv4-entry* [prefix]
     |     +--ro prefix    -> ../state/prefix
     |     +--ro state
     |        +--ro prefix?                            oc-inet:ipv4-prefix
     |        +--ro entry-metadata?                    binary
     |        +--ro decapsulate-header?                oc-aftt:encapsulation-header-type
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro ipv6-unicast
     |  +--ro ipv6-entry* [prefix]
     |     +--ro prefix    -> ../state/prefix
     |     +--ro state
     |        +--ro prefix?                            oc-inet:ipv6-prefix
     |        +--ro entry-metadata?                    binary
     |        +--ro decapsulate-header?                oc-aftt:encapsulation-header-type
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro policy-forwarding
     |  +--ro policy-forwarding-entry* [index]
     |     +--ro index    -> ../state/index
     |     +--ro state
     |        +--ro index?                             uint64
     |        +--ro ip-prefix?                         oc-inet:ip-prefix
     |        +--ro mac-address?                       oc-yang:mac-address
     |        +--ro mpls-label?                        oc-mplst:mpls-label
     |        +--ro mpls-tc?                           oc-mplst:mpls-tc
     |        +--ro ip-dscp?                           oc-inet:dscp
     |        +--ro ip-protocol?                       oc-pkt-match-types:ip-protocol-type
     |        +--ro l4-src-port?                       oc-inet:port-number
     |        +--ro l4-dst-port?                       oc-inet:port-number
     |        +--ro entry-metadata?                    binary
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro mpls
     |  +--ro label-entry* [label]
     |     +--ro label    -> ../state/label
     |     +--ro state
     |        +--ro label?                             oc-mplst:mpls-label
     |        +--ro entry-metadata?                    binary
     |        +--ro popped-mpls-label-stack*           oc-mplst:mpls-label
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro ethernet
     |  +--ro mac-entry* [mac-address]
     |     +--ro mac-address    -> ../state/mac-address
     |     +--ro state
     |        +--ro mac-address?                       oc-yang:mac-address
     |        +--ro entry-metadata?                    binary
     |        +--ro next-hop-group?                    uint64
     |        +--ro next-hop-group-network-instance?   string
     +--ro srv6
     |  +--ro srv6-sid-entry* [sid]
     |     +--ro sid      -> ../state/sid
     |     +--ro state
     |        +--ro sid?              oc-inet:ipv6-prefix
     |        +--ro sid-params
     |        |  +--ro behavior-type              uint16
     |        |  +--ro lookup-network-instance?   string
     |        |  +--ro interface?                 if:interface-ref
     |        |  +--ro next-hop?                  oc-inet:ip-address
     |        |  +--ro encap-object-bsid
     |        |     +--ro encap-type?            enumeration
     |        |     +--ro srv6-sidlist*          oc-inet:ipv6-address
     |        |     +--ro sr-mpls-label-stack*   oc-mplst:mpls-label
     |        +--ro counters
     |        |  +--ro packets-forwarded?   oc-yang:counter64
     |        |  +--ro octets-forwarded?    oc-yang:counter64
     |        +--ro entry-metadata?   binary
     +--ro next-hop-groups
     |  +--ro next-hop-group* [id]
     |     +--ro id           -> ../state/id
     |     +--ro state
     |     |  +--ro id?                      uint64
     |     |  +--ro color?                   uint64
     |     |  +--ro backup-next-hop-group?   -> ../../../next-hop-group/state/id
     |     +--ro next-hops
     |        +--ro next-hop* [index]
     |           +--ro index    -> ../state/index
     |           +--ro state
     |              +--ro index?    -> ../../../../../../next-hops/next-hop/state/index
     |              +--ro weight?   uint64
     +--ro next-hops
        +--ro next-hop* [index]
           +--ro index            -> ../state/index
           +--ro state
           |  +--ro index?                     uint64
           |  +--ro ip-address?                oc-inet:ip-address
           |  +--ro mac-address?               oc-yang:mac-address
           |  +--ro pop-top-label?             boolean
           |  +--ro pushed-mpls-label-stack*   oc-mplst:mpls-label
           |  +--ro encapsulate-header?        oc-aftt:encapsulation-header-type
           |  +--ro decapsulate-header?        oc-aftt:encapsulation-header-type
           |  +--ro vni-label?                 oc-evpn-types:evi-id
           |  +--ro tunnel-src-ip-address?     oc-inet:ip-address
           |  +--ro network-instance?          string
           +--ro ip-in-ip
           |  +--ro state
           |     +--ro src-ip?          oc-inet:ip-address
           |     +--ro dst-ip?          oc-inet:ip-address
           |     +--ro srv6-sid-list*   oc-inet:ipv6-address
           |     +--ro flow-label?      uint32
           |     +--ro traffic-class?   uint8
           |     +--ro hop-limit?       uint8
           +--ro gre
           |  +--ro state
           |     +--ro src-ip?   oc-inet:ip-address
           |     +--ro dst-ip?   oc-inet:ip-address
           |     +--ro ttl?      uint8
           +--ro encap-headers
           |  +--ro encap-header* [index]
           |     +--ro index     -> ../state/index
           |     +--ro state
           |     |  +--ro index?   uint8
           |     |  +--ro type?    oc-aftt:encapsulation-header-type
           |     +--ro gre
           |     |  +--ro state
           |     |     +--ro src-ip?   oc-inet:ip-address
           |     |     +--ro dst-ip?   oc-inet:ip-address
           |     |     +--ro ttl?      uint8
           |     +--ro ipv4
           |     |  +--ro state
           |     |     +--ro src-ip?          oc-inet:ip-address
           |     |     +--ro dst-ip?          oc-inet:ip-address
           |     |     +--ro srv6-sid-list*   oc-inet:ipv6-address
           |     |     +--ro flow-label?      uint32
           |     |     +--ro traffic-class?   uint8
           |     |     +--ro hop-limit?       uint8
           |     +--ro ipv6
           |     |  +--ro state
           |     |     +--ro src-ip?          oc-inet:ip-address
           |     |     +--ro dst-ip?          oc-inet:ip-address
           |     |     +--ro srv6-sid-list*   oc-inet:ipv6-address
           |     |     +--ro flow-label?      uint32
           |     |     +--ro traffic-class?   uint8
           |     |     +--ro hop-limit?       uint8
           |     +--ro mpls
           |     |  +--ro state
           |     |     +--ro traffic-class?      oc-mplst:mpls-tc
           |     |     +--ro mpls-label-stack*   oc-mplst:mpls-label
           |     +--ro udp-v4
           |     |  +--ro state
           |     |     +--ro src-ip?         oc-inet:ip-address
           |     |     +--ro dst-ip?         oc-inet:ip-address
           |     |     +--ro dscp?           oc-inet:dscp
           |     |     +--ro src-udp-port?   oc-inet:port-number
           |     |     +--ro dst-udp-port?   oc-inet:port-number
           |     |     +--ro ip-ttl?         uint8
           |     +--ro udp-v6
           |        +--ro state
           |           +--ro src-ip?         oc-inet:ip-address
           |           +--ro dst-ip?         oc-inet:ip-address
           |           +--ro dscp?           oc-inet:dscp
           |           +--ro src-udp-port?   oc-inet:port-number
           |           +--ro dst-udp-port?   oc-inet:port-number
           |           +--ro ip-ttl?         uint8
           +--ro interface-ref
              +--ro state
                 +--ro interface?      -> /oc-if:interfaces/interface/name
                 +--ro subinterface?   -> /oc-if:interfaces/interface[oc-if:name=current()/../interface]/subinterfaces/subinterface/index

[robshakir]

Diff from tree view:

➜  gribi git:(srv6_support) diff -prauwN ~/tmp/gribi-tree ~/tmp/gribi-tree-srv6
--- /Users/robjs/tmp/gribi-tree	2025-12-09 10:14:50
+++ /Users/robjs/tmp/gribi-tree-srv6	2025-12-09 10:15:16
@@ -51,6 +51,24 @@ module: gribi-aft
      |        +--ro entry-metadata?                    binary
      |        +--ro next-hop-group?                    uint64
      |        +--ro next-hop-group-network-instance?   string
+     +--ro srv6
+     |  +--ro srv6-sid-entry* [sid]
+     |     +--ro sid      -> ../state/sid
+     |     +--ro state
+     |        +--ro sid?              oc-inet:ipv6-prefix
+     |        +--ro sid-params
+     |        |  +--ro behavior-type              uint16
+     |        |  +--ro lookup-network-instance?   string
+     |        |  +--ro interface?                 if:interface-ref
+     |        |  +--ro next-hop?                  oc-inet:ip-address
+     |        |  +--ro encap-object-bsid
+     |        |     +--ro encap-type?            enumeration
+     |        |     +--ro srv6-sidlist*          oc-inet:ipv6-address
+     |        |     +--ro sr-mpls-label-stack*   oc-mplst:mpls-label
+     |        +--ro counters
+     |        |  +--ro packets-forwarded?   oc-yang:counter64
+     |        |  +--ro octets-forwarded?    oc-yang:counter64
+     |        +--ro entry-metadata?   binary
      +--ro next-hop-groups
      |  +--ro next-hop-group* [id]
      |     +--ro id           -> ../state/id
@@ -82,6 +100,10 @@ module: gribi-aft
            |  +--ro state
            |     +--ro src-ip?   oc-inet:ip-address
            |     +--ro dst-ip?   oc-inet:ip-address
+           |     +--ro srv6-sid-list*   oc-inet:ipv6-address
+           |     +--ro flow-label?      uint32
+           |     +--ro traffic-class?   uint8
+           |     +--ro hop-limit?       uint8
            +--ro gre
            |  +--ro state
            |     +--ro src-ip?   oc-inet:ip-address
@@ -102,10 +124,18 @@ module: gribi-aft
            |     |  +--ro state
            |     |     +--ro src-ip?   oc-inet:ip-address
            |     |     +--ro dst-ip?   oc-inet:ip-address
+           |     |     +--ro srv6-sid-list*   oc-inet:ipv6-address
+           |     |     +--ro flow-label?      uint32
+           |     |     +--ro traffic-class?   uint8
+           |     |     +--ro hop-limit?       uint8
            |     +--ro ipv6
            |     |  +--ro state
            |     |     +--ro src-ip?   oc-inet:ip-address
            |     |     +--ro dst-ip?   oc-inet:ip-address
+           |     |     +--ro srv6-sid-list*   oc-inet:ipv6-address
+           |     |     +--ro flow-label?      uint32
+           |     |     +--ro traffic-class?   uint8
+           |     |     +--ro hop-limit?       uint8
            |     +--ro mpls
            |     |  +--ro state
            |     |     +--ro traffic-class?      oc-mplst:mpls-tc

[robshakir]

Paths diff:

➜  gribi git:(master) diff -prawuN /tmp/existing-paths /tmp/srv6-paths
--- /tmp/existing-paths	2025-12-09 10:19:29
+++ /tmp/srv6-paths	2025-12-09 10:19:15
@@ -50,6 +50,24 @@
 /afts/ethernet/mac-entry/state/entry-metadata
 /afts/ethernet/mac-entry/state/next-hop-group
 /afts/ethernet/mac-entry/state/next-hop-group-network-instance
+/afts/srv6
+/afts/srv6/srv6-sid-entry
+/afts/srv6/srv6-sid-entry/sid
+/afts/srv6/srv6-sid-entry/state
+/afts/srv6/srv6-sid-entry/state/sid
+/afts/srv6/srv6-sid-entry/state/sid-params
+/afts/srv6/srv6-sid-entry/state/sid-params/behavior-type
+/afts/srv6/srv6-sid-entry/state/sid-params/lookup-network-instance
+/afts/srv6/srv6-sid-entry/state/sid-params/interface
+/afts/srv6/srv6-sid-entry/state/sid-params/next-hop
+/afts/srv6/srv6-sid-entry/state/sid-params/encap-object-bsid
+/afts/srv6/srv6-sid-entry/state/sid-params/encap-object-bsid/encap-type
+/afts/srv6/srv6-sid-entry/state/sid-params/encap-object-bsid/srv6-sidlist
+/afts/srv6/srv6-sid-entry/state/sid-params/encap-object-bsid/sr-mpls-label-stack
+/afts/srv6/srv6-sid-entry/state/counters
+/afts/srv6/srv6-sid-entry/state/counters/packets-forwarded
+/afts/srv6/srv6-sid-entry/state/counters/octets-forwarded
+/afts/srv6/srv6-sid-entry/state/entry-metadata
 /afts/next-hop-groups
 /afts/next-hop-groups/next-hop-group
 /afts/next-hop-groups/next-hop-group/id
@@ -81,6 +99,10 @@
 /afts/next-hops/next-hop/ip-in-ip/state
 /afts/next-hops/next-hop/ip-in-ip/state/src-ip
 /afts/next-hops/next-hop/ip-in-ip/state/dst-ip
+/afts/next-hops/next-hop/ip-in-ip/state/srv6-sid-list
+/afts/next-hops/next-hop/ip-in-ip/state/flow-label
+/afts/next-hops/next-hop/ip-in-ip/state/traffic-class
+/afts/next-hops/next-hop/ip-in-ip/state/hop-limit
 /afts/next-hops/next-hop/gre
 /afts/next-hops/next-hop/gre/state
 /afts/next-hops/next-hop/gre/state/src-ip
@@ -101,10 +123,18 @@
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/src-ip
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/dst-ip
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/srv6-sid-list
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/flow-label
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/traffic-class
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv4/state/hop-limit
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv6
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/src-ip
 /afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/dst-ip
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/srv6-sid-list
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/flow-label
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/traffic-class
+/afts/next-hops/next-hop/encap-headers/encap-header/ipv6/state/hop-limit
 /afts/next-hops/next-hop/encap-headers/encap-header/mpls
 /afts/next-hops/next-hop/encap-headers/encap-header/mpls/state
 /afts/next-hops/next-hop/encap-headers/encap-header/mpls/state/traffic-class

[robshakir]

A few comments:

• Let's discuss what the difference between an SRv6 entry and an IPv6 entry is -- we should clarify how a device is intended to handle the two in terms of lookup logic.
• lookup-network-instance is likely not required to match the current structure. The AFT subtree for telemetry is rooted under /network-instances/network-instance and the gRIBI proto itself has a network_instance field that is used to determine which VRF is being populated.
• For the interface and next-hop leaves that are under the srv6-entry. I think this structure breaks how the current fundamental layout of the AFTs are in gRIBI. Particularly:
  • An XX-entry (IPv4 prefix, IPv6 prefix, MPLS label...) links to a next-hop-group which can be in the local or another network-instance. These entries tend to not have actions associated with them -- although an exception is a "pop" action for MPLS.
  • A next-hop-group contains a set of next-hops that have weights associated with them.
  • A next-hop then has where the packet is to be forwarded and any actions associated with it.
  • Based on this, I think I'd expect that the interface and next-hop can be programmed within a next-hop entry, and the SRv6 entries themselves don't include this. WDYT?
• For the encap-object-bsid leaves. Can you explain to me why these are different to other encapsulation types? For SR-MPLS, how we have been doing this thus far is that we have a MPLS, IPv4 or IPv6 entry which has a NHG and then NH - each NH has a pushed-mpls-label-stack (although with the recent changes to encap-headers it would now have one or more entries in that list). Is there a reason that such an approach wouldn't work for the SRv6 SID list?
• We probably need to modify the way that the flow-label, traffic-class and hop-limit are being specified since they now show up for IPv4 too. I think it sounds reasonable to add these (although I am not sure that all silicon can implement them today).