Internet-Draft | A YANG Data Model for IP Traffic Flow Se | October 2021 |
Fedyk & Hopps | Expires 28 April 2022 | [Page] |
This document describes a yang module for the management of IP Traffic Flow Security additions to IKEv2 and IPsec.¶
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This document defines a YANG module [RFC7950] for the management of the IP Traffic Flow Security (IP-TFS) extensions as defined in [I-D.ietf-ipsecme-iptfs]. IP-TFS provides enhancements to an IPsec tunnel Security Association to provide improved traffic confidentiality. Traffic confidentiality reduces the ability of traffic analysis to determine identity and correlate observable traffic patterns. IP-TFS offers efficiency when aggregating traffic in fixed size IPsec tunnel packets.¶
The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].¶
The published YANG modules for IPsec are defined in [RFC9061]. This document uses these models as a general IPsec model that is augmented for IP-TFS. The models in [RFC9061] provide for both an IKE and an IKELESS model.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
This document defines configuration and operational parameters of IP traffic flow security (IP-TFS). IP-TFS, defined in [I-D.ietf-ipsecme-iptfs], defines a security association for tunnel mode IPsec with characteristics that improve traffic confidentiality and reduce bandwidth efficiency loss. These documents assume familiarity with IP security concepts described in [RFC4301].¶
IP-TFS uses tunnel mode to improve confidentiality by hiding inner packet identifiable information, packet size and packet timing. IP-TFS provides a general capability allowing aggregation of multiple packets in uniform size outer tunnel ipsec packets. It maintains the outer packet size by utilizing combinations of aggregating, padding and fragmentating inner packets to fll out the IPsec outer tunnel packet. Zero byte padding is used to fill the packet when no data is available to send.¶
This document specifies an extensible configuration model for IP-TFS. This version utilizes the capabilities of IP-TFS to configure fixed size IP-TFS Packets that are transmitted at a constant rate. This model is structured to allow for different types of operation through future augmentation.¶
IP-TFS YANG augments IPsec YANG model from [RFC9061]. IP-TFS makes use of IPsec tunnel mode and adds a small number configuration items to tunnel mode IPsec. As defined in [I-D.ietf-ipsecme-iptfs], any SA configured to use IP-TFS supports only IP-TFS packets i.e. no mixed IPsec modes.¶
The behavior for IP-TFS is controlled by the source. The self-describing format of an IP-TFS packets allows a sending side to adjust the packet-size and timing independently from any receiver. Both directions are also independent, e.g. IP-TFS may be run only in one direction. This means that counters, which are created here for both directions may be 0 or not updated in the case of an SA that uses IP-TFS only in on direction.¶
Cases where IP-TFS statistics are active for one direction:¶
Case where IP-TFS statistics are for both directions:¶
The IP-TFS model support IP-TFS configuration and operational data.¶
This YANG module supports configuration of fixed size and fixed rate packets, and elements that may be augmented to support future configuration. The protocol specification [I-D.ietf-ipsecme-iptfs], goes beyond this simple fixed mode of operation by defining a general format for any type of scheme. In this document the outer IPsec packets can be sent with fixed or variable size (without padding). The configuration allows the fixed packet size to be determined by the path MTU. The fixed packet size can also be configured if a value lower than the path MTU is desired.¶
Other configuration items include:¶
The YANG operational data allows the readout of the configured parameters as well as the per SA statistics and error counters for IP-TFS. Per SA IPsec packet statistics are provided as a feature and per SA IP-TFS specific statistics as another feature. Both sets of statistics augment the IPsec YANG models with counters that allow observation of IP-TFS packet efficiency.¶
RFC [RFC9061] has a set of IPsec YANG management objects. IP-TFS YANG augments the IKE and the IKELESS models. In these models the Security Policy database entry and Security Association entry for an IPsec Tunnel can be augmented with IP-TFS.¶
The following is the YANG tree diagram ([RFC8340]) for the IP-TFS extensions.¶
module: ietf-ipsec-iptfs augment /nsfike:ipsec-ike/nsfike:conn-entry/nsfike:spd /nsfike:spd-entry/nsfike:ipsec-policy-config /nsfike:processing-info/nsfike:ipsec-sa-cfg: +--rw traffic-flow-security +--rw congestion-control? boolean +--rw packet-size | +--rw use-path-mtu-discovery? boolean | +--rw outer-packet-size? uint16 +--rw (tunnel-rate)? | +--:(l2-fixed-rate) | | +--rw l2-fixed-rate? yang:counter64 | +--:(l3-fixed-rate) | +--rw l3-fixed-rate? yang:counter64 +--rw dont-fragment? boolean +--rw max-aggregation-time? decimal64 augment /nsfike:ipsec-ike/nsfike:conn-entry/nsfike:child-sa-info: +--ro traffic-flow-security +--ro congestion-control? boolean +--ro packet-size | +--ro use-path-mtu-discovery? boolean | +--ro outer-packet-size? uint16 +--ro (tunnel-rate)? | +--:(l2-fixed-rate) | | +--ro l2-fixed-rate? yang:counter64 | +--:(l3-fixed-rate) | +--ro l3-fixed-rate? yang:counter64 +--ro dont-fragment? boolean +--ro max-aggregation-time? decimal64 augment /nsfikels:ipsec-ikeless/nsfikels:spd/nsfikels:spd-entry /nsfikels:ipsec-policy-config/nsfikels:processing-info /nsfikels:ipsec-sa-cfg: +--rw traffic-flow-security +--rw congestion-control? boolean +--rw packet-size | +--rw use-path-mtu-discovery? boolean | +--rw outer-packet-size? uint16 +--rw (tunnel-rate)? | +--:(l2-fixed-rate) | | +--rw l2-fixed-rate? yang:counter64 | +--:(l3-fixed-rate) | +--rw l3-fixed-rate? yang:counter64 +--rw dont-fragment? boolean +--rw max-aggregation-time? decimal64 augment /nsfikels:ipsec-ikeless/nsfikels:sad/nsfikels:sad-entry: +--ro traffic-flow-security +--ro congestion-control? boolean +--ro packet-size | +--ro use-path-mtu-discovery? boolean | +--ro outer-packet-size? uint16 +--ro (tunnel-rate)? | +--:(l2-fixed-rate) | | +--ro l2-fixed-rate? yang:counter64 | +--:(l3-fixed-rate) | +--ro l3-fixed-rate? yang:counter64 +--ro dont-fragment? boolean +--ro max-aggregation-time? decimal64 augment /nsfike:ipsec-ike/nsfike:conn-entry/nsfike:child-sa-info: +--ro ipsec-stats {ipsec-stats}? | +--ro tx-pkts? yang:counter64 | +--ro tx-octets? yang:counter64 | +--ro tx-drop-pkts? yang:counter64 | +--ro rx-pkts? yang:counter64 | +--ro rx-octets? yang:counter64 | +--ro rx-drop-pkts? yang:counter64 +--ro iptfs-inner-pkt-stats {iptfs-stats}? | +--ro tx-pkts? yang:counter64 | +--ro tx-octets? yang:counter64 | +--ro rx-pkts? yang:counter64 | +--ro rx-octets? yang:counter64 | +--ro rx-incomplete-pkts? yang:counter64 +--ro iptfs-outer-pkt-stats {iptfs-stats}? +--ro tx-all-pad-pkts? yang:counter64 +--ro tx-all-pad-octets? yang:counter64 +--ro tx-extra-pad-pkts? yang:counter64 +--ro tx-extra-pad-octets? yang:counter64 +--ro rx-all-pad-pkts? yang:counter64 +--ro rx-all-pad-octets? yang:counter64 +--ro rx-extra-pad-pkts? yang:counter64 +--ro rx-extra-pad-octets? yang:counter64 +--ro rx-errored-pkts? yang:counter64 +--ro rx-missed-pkts? yang:counter64 augment /nsfikels:ipsec-ikeless/nsfikels:sad/nsfikels:sad-entry: +--rw ipsec-stats {ipsec-stats}? | +--ro tx-pkts? yang:counter64 | +--ro tx-octets? yang:counter64 | +--ro tx-drop-pkts? yang:counter64 | +--ro rx-pkts? yang:counter64 | +--ro rx-octets? yang:counter64 | +--ro rx-drop-pkts? yang:counter64 +--ro iptfs-inner-pkt-stats {iptfs-stats}? | +--ro tx-pkts? yang:counter64 | +--ro tx-octets? yang:counter64 | +--ro rx-pkts? yang:counter64 | +--ro rx-octets? yang:counter64 | +--ro rx-incomplete-pkts? yang:counter64 +--ro iptfs-outer-pkt-stats {iptfs-stats}? +--ro tx-all-pad-pkts? yang:counter64 +--ro tx-all-pad-octets? yang:counter64 +--ro tx-extra-pad-pkts? yang:counter64 +--ro tx-extra-pad-octets? yang:counter64 +--ro rx-all-pad-pkts? yang:counter64 +--ro rx-all-pad-octets? yang:counter64 +--ro rx-extra-pad-pkts? yang:counter64 +--ro rx-extra-pad-octets? yang:counter64 +--ro rx-errored-pkts? yang:counter64 +--ro rx-missed-pkts? yang:counter64¶
The following is the YANG module for managing the IP-TFS extensions. The model contains references to [I-D.ietf-ipsecme-iptfs] and [RFC5348].¶
<CODE BEGINS> file "ietf-ipsec-iptfs@2021-10-25.yang" module ietf-ipsec-iptfs { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ipsec-iptfs"; prefix iptfs; import ietf-i2nsf-ike { prefix nsfike; } import ietf-i2nsf-ikeless { prefix nsfikels; } import ietf-yang-types { prefix yang; } organization "IETF IPSECME Working Group (IPSECME)"; contact "WG Web: <https://tools.ietf.org/wg/ipsecme/> WG List: <mailto:ipsecme@ietf.org> Author: Don Fedyk <mailto:dfedyk@labn.net> Author: Christian Hopps <mailto:chopps@chopps.org>"; // RFC Ed.: replace XXXX with actual RFC number and // remove this note. description "This module defines the configuration and operational state for managing the IP Traffic Flow Security functionality [RFC XXXX]. Copyright (c) 2021 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://tools.ietf.org/html/rfcXXXX); see the RFC itself for full legal notices."; revision 2021-10-25 { description "Initial Revision"; reference "RFC XXXX: IP Traffic Flow Security YANG Module"; } feature ipsec-stats { description "This feature indicates the device supports per SA IPsec statistics"; } feature iptfs-stats { description "This feature indicates the device supports per SA IP Traffic Flow Security statistics"; } /*--------------------*/ /* groupings */ /*--------------------*/ grouping ipsec-tx-stat-grouping { description "IPsec outbound statistics"; leaf tx-pkts { type yang:counter64; config false; description "Outbound Packet count"; } leaf tx-octets { type yang:counter64; config false; description "Outbound Packet bytes"; } leaf tx-drop-pkts { type yang:counter64; config false; description "Outbound dropped packets count"; } } grouping ipsec-rx-stat-grouping { description "IPsec inbound statistics"; leaf rx-pkts { type yang:counter64; config false; description "Inbound Packet count"; } leaf rx-octets { type yang:counter64; config false; description "Inbound Packet bytes"; } leaf rx-drop-pkts { type yang:counter64; config false; description "Inbound dropped packets count"; } } grouping iptfs-inner-tx-stat-grouping { description "IP-TFS outbound inner packet statistics"; leaf tx-pkts { type yang:counter64; config false; description "Total number of IP-TFS inner packets sent. This count is whole packets only. A fragmented packet counts as one packet"; reference "draft-ietf-ipsecme-iptfs"; } leaf tx-octets { type yang:counter64; config false; description "Total number of IP-TFS inner octets sent. This is inner packet octets only. Does not count padding."; reference "draft-ietf-ipsecme-iptfs"; } } grouping iptfs-outer-tx-stat-grouping { description "IP-TFS outbound inner packet statistics"; leaf tx-all-pad-pkts { type yang:counter64; config false; description "Total number of transmitted IP-TFS packets that were all padding with no inner packet data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3"; } leaf tx-all-pad-octets { type yang:counter64; config false; description "Total number transmitted octets of padding added to IP-TFS packets with no inner packet data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3"; } leaf tx-extra-pad-pkts { type yang:counter64; config false; description "Total number of transmitted outer IP-TFS packets that included some padding."; reference "draft-ietf-ipsecme-iptfs section 2.2.3.1"; } leaf tx-extra-pad-octets { type yang:counter64; config false; description "Total number of transmitted octets of padding added to outer IP-TFS packets with data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3.1"; } } grouping iptfs-inner-rx-stat-grouping { description "IP-TFS inner packet inbound statistics"; leaf rx-pkts { type yang:counter64; config false; description "Total number of IP-TFS inner packets received."; reference "draft-ietf-ipsecme-iptfs section 2.2"; } leaf rx-octets { type yang:counter64; config false; description "Total number of IP-TFS inner octets received. Does not include padding or overhead"; reference "draft-ietf-ipsecme-iptfs section 2.2"; } leaf rx-incomplete-pkts { type yang:counter64; config false; description "Total number of IP-TFS inner packets that were incomplete. Usually this is due to fragments not received. Also, this may be due to misordering or errors in received outer packets."; reference "draft-ietf-ipsecme-iptfs"; } } grouping iptfs-outer-rx-stat-grouping { description "IP-TFS outer packet inbound statistics"; leaf rx-all-pad-pkts { type yang:counter64; config false; description "Total number of received IP-TFS packets that were all padding with no inner packet data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3"; } leaf rx-all-pad-octets { type yang:counter64; config false; description "Total number received octets of padding added to IP-TFS packets with no inner packet data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3"; } leaf rx-extra-pad-pkts { type yang:counter64; config false; description "Total number of received outer IP-TFS packets that included some padding."; reference "draft-ietf-ipsecme-iptfs section 2.2.3.1"; } leaf rx-extra-pad-octets { type yang:counter64; config false; description "Total number of received octets of padding added to outer IP-TFS packets with data."; reference "draft-ietf-ipsecme-iptfs section 2.2.3.1"; } leaf rx-errored-pkts { type yang:counter64; config false; description "Total number of IP-TFS outer packets dropped due to errors."; reference "draft-ietf-ipsecme-iptfs"; } leaf rx-missed-pkts { type yang:counter64; config false; description "Total number of IP-TFS outer packets missing indicated by missing sequence number."; reference "draft-ietf-ipsecme-iptfs"; } } grouping iptfs-config { description "This is the grouping for iptfs configuration"; container traffic-flow-security { description "Configure the IPSec TFS in Security Association Database (SAD)"; leaf congestion-control { type boolean; default "true"; description "When set to true, the default, this enables the congestion control on-the-wire exchange of data that is required by congestion control algorithms as defined by RFC 5348. When set to false, IP-TFS sends fixed-sized packets over an IP-TFS tunnel at a constant rate."; reference "draft-ietf-ipsecme-iptfs section 2.5.2, RFC 5348"; } container packet-size { description "Packet size is either auto-discovered or manually configured."; leaf use-path-mtu-discovery { type boolean; default "true"; description "Utilize path mtu discovery to determine maximum IP-TFS packet size. If the packet size is explicitly configured, then it will only be adjusted downward if use-path-mtu-discovery is set."; reference "draft-ietf-ipsecme-iptfs section 4.2"; } leaf outer-packet-size { type uint16; description "The size of the outer encapsulating tunnel packet (i.e., the IP packet containing the ESP payload)."; reference "draft-ietf-ipsecme-iptfs section 4.2"; } } choice tunnel-rate { description "TFS bit rate may be specified at layer 2 wire rate or layer 3 packet rate"; leaf l2-fixed-rate { type yang:counter64; description "Target bandwidth/bit rate in bps for iptfs tunnel. This fixed rate is the nominal timing for the fixed size packet. If congestion control is enabled the rate may be adjusted down (or up if unset)."; reference "draft-ietf-ipsecme-iptfs section 4.1"; } leaf l3-fixed-rate { type yang:counter64; description "Target bandwidth/bit rate in bps for iptfs tunnel. This fixed rate is the nominal timing for the fixed size packet. If congestion control is enabled the rate may be adjusted down (or up if unset)."; reference "draft-ietf-ipsecme-iptfs section 4.1"; } } leaf dont-fragment { type boolean; default "false"; description "Disable packet fragmentation across consecutive iptfs tunnel packets"; reference "draft-ietf-ipsecme-iptfs section 2.2.4 and 6.4.1"; } leaf max-aggregation-time { type decimal64 { fraction-digits 6; } units "milliseconds"; description "Maximum Aggregation Time in Milliseconds or fractional milliseconds down to 1 nanosecond"; } } } /* * IP-TFS ike configuration */ augment "/nsfike:ipsec-ike/nsfike:conn-entry/nsfike:spd/" + "nsfike:spd-entry/" + "nsfike:ipsec-policy-config/" + "nsfike:processing-info/" + "nsfike:ipsec-sa-cfg" { description "IP-TFS configuration for this policy."; uses iptfs-config; } augment "/nsfike:ipsec-ike/nsfike:conn-entry/" + "nsfike:child-sa-info" { description "IP-TFS configured on this SA."; uses iptfs-config { refine "traffic-flow-security" { config false; } } } /* * IP-TFS ikeless configuration */ augment "/nsfikels:ipsec-ikeless/nsfikels:spd/" + "nsfikels:spd-entry/" + "nsfikels:ipsec-policy-config/" + "nsfikels:processing-info/" + "nsfikels:ipsec-sa-cfg" { description "IP-TFS configuration for this policy."; uses iptfs-config; } augment "/nsfikels:ipsec-ikeless/nsfikels:sad/" + "nsfikels:sad-entry" { description "IP-TFS configured on this SA."; uses iptfs-config { refine "traffic-flow-security" { config false; } } } /* * packet counters */ augment "/nsfike:ipsec-ike/nsfike:conn-entry/" + "nsfike:child-sa-info" { description "Per SA Counters"; container ipsec-stats { if-feature "ipsec-stats"; config false; description "IPsec per SA packet counters."; uses ipsec-tx-stat-grouping { //when "direction = 'outbound'"; } uses ipsec-rx-stat-grouping { //when "direction = 'inbound'"; } } container iptfs-inner-pkt-stats { if-feature "iptfs-stats"; config false; description "IPTFS per SA inner packet counters."; uses iptfs-inner-tx-stat-grouping { //when "direction = 'outbound'"; } uses iptfs-inner-rx-stat-grouping { //when "direction = 'inbound'"; } } container iptfs-outer-pkt-stats { if-feature "iptfs-stats"; config false; description "IPTFS per SA outer packets counters."; uses iptfs-outer-tx-stat-grouping { //when "direction = 'outbound'"; } uses iptfs-outer-rx-stat-grouping { //when "direction = 'inbound'"; } } } /* * packet counters */ augment "/nsfikels:ipsec-ikeless/nsfikels:sad/" + "nsfikels:sad-entry" { description "Per SA Counters"; container ipsec-stats { if-feature "ipsec-stats"; description "IPsec per SA packet counters."; uses ipsec-tx-stat-grouping { //when "direction = 'outbound'"; } uses ipsec-rx-stat-grouping { //when "direction = 'inbound'"; } } container iptfs-inner-pkt-stats { if-feature "iptfs-stats"; config false; description "IPTFS per SA inner packet counters."; uses iptfs-inner-tx-stat-grouping { //when "direction = 'outbound'"; } uses iptfs-inner-rx-stat-grouping { //when "direction = 'inbound'"; } } container iptfs-outer-pkt-stats { if-feature "iptfs-stats"; config false; description "IPTFS per SA outer packets counters."; uses iptfs-outer-tx-stat-grouping { //when "direction = 'outbound'"; } uses iptfs-outer-rx-stat-grouping { //when "direction = 'inbound'"; } } } } <CODE ENDS>¶
This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in [RFC3688], the following registration has been made:¶
This document registers one YANG module in the "YANG Module Names" registry [RFC6020]. Following the format in [RFC6020], the following registration has been made:¶
The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].¶
The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.¶
The YANG module defined in this document can enable, disable and modify the behavior of IP traffic flow security, for the implications regarding these types of changes consult the [I-D.ietf-ipsecme-iptfs] which defines the functionality.¶
The authors would like to thank Eric Kinzie and Juergen Schoenwaelder for their feedback and review on the YANG model.¶
The following examples show configuration and operational data for the ikeless case in xml and ike case in json. Also, the operational statistics for the ikeless case are shown using xml.¶
This example illustrates configuration for IP-TFS in the ikeless case. Note that since this augments the ipsec ikeless schema only minimal ikeless configuration to satisfy the schema has been populated.¶
This example illustrates operational data for IP-TFS in the ikeless case. Note that since this augments the ipsec ikeless schema only minimal ikeless configuration to satisfy the schema has been populated.¶
This example illustrates config data for IP-TFS in the ike case. Note that since this augments the ipsec ike schema only minimal ike configuration to satisfy the schema has been populated.¶
This example illustrates operational data for IP-TFS in the ike case. Note that since this augments the ipsec ike tree only minimal ike configuration to satisfy the schema has been populated.¶
This example shows the json formated statistics for IP-TFS. Note a unidirectional IP-TFS transmit side is illustrated, with arbitray numbers for transmit.¶