Network Working Group M. Boucadair Internet-Draft France Telecom Intended status: Standards Track R. Penno Expires: October 27, 2012 D. Wing Cisco April 25, 2012 Some Extensions to Port Control Protocol (PCP) draft-boucadair-pcp-extensions-03 Abstract This document extends Port Control Protocol (PCP) with new functionalities. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on October 27, 2012. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents Boucadair, et al. Expires October 27, 2012 [Page 1] Internet-Draft Extensions to PCP April 2012 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. DSCP_POLICY . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. CAPABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. REPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. CLIENT_IDENTIFIER . . . . . . . . . . . . . . . . . . . . . . 9 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 9. Normative References . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Boucadair, et al. Expires October 27, 2012 [Page 2] Internet-Draft Extensions to PCP April 2012 1. Introduction This document extends the base PCP [I-D.ietf-pcp-base] with various PCP Options. Some of these options may be defined as new PCP OpCodes. The main goal of this document is to kick-off discussions on the need to define some useful PCP options which are not part of base PCP. 2. DESCRIPTION This option (Code TBA, Figure 1) MAY be included in a PCP MAP request to include a description associated with a requested mapping. This option is optional to be supported by PCP Servers and PCP Clients. The maximum length SHOULD be a configurable option in the PCP Server. If a PCP Client includes a Description PCP option with a length exceeding the maximum length supported by the PCP Server, only the portion of the Description field fitting that maximum length is stored by the PCP Server. This option can be used by a user to indicate a description associated with a given mapping such as "My mapping for my FTP server" or "My remote access to my CP router", etc. In addition, in the some deployment scenarios, this field can be used for troubleshooting purposes and can be used to convey values as the ones listed hereafter: o "This is the mapping for my specific IPsec implementation" o "This is the mapping for subscriber bob@example.com" o "This is the mapping for special subscriber adsl-line-1234@example.com" o "This is the mapping that failed before due to XYZ" Issues related to the usage of this field for troubleshooting or for any further usage are out of scope of this document. Boucadair, et al. Expires October 27, 2012 [Page 3] Internet-Draft Extensions to PCP April 2012 This Option: Option Name: Description Option (DESCRIPTION) Number: TBA (IANA) Purpose: Used to associate a text description with a mapping Valid for Opcodes: MAP Length: Variable May appear in: both request and response Maximum occurrences: 1 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DESCRIPTION | Reserved | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Description | : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Description Option 3. DSCP_POLICY In some scenarios, the DSCP marking in the internal interface (i.e., customer-facing interface) and the external one (i.e., Internet- facing interface) of the PCP-controlled device may be distinct. A Service Provider MAY allow its customers to configure their DSCP marking policies in an upstream device. Distinct DSCP marking policies can be implemented in the internal and external sides of the PCP-controlled device. A PCP Client MAY issue a PCP MAP request indicating its internal DS code point and the external DSCP value. Instructed forwarding policies are applied only for packets marked with a given DSCP value. A Service Provider may not support DSCP re-marking feature and adopt a transparent scheme to QoS policy enforcement, that is, not controllable by subscribers. Generic QoS enforcement policies can be enforced for all customers: such as leave DSCP field values unchanged. This option is mandatory to process. This option (Code TBA, Figure 2) allows to: o Re-write any DSCP value to a specific value; Boucadair, et al. Expires October 27, 2012 [Page 4] Internet-Draft Extensions to PCP April 2012 o Re-write a specific DSCP value to another specific value. This Option: Option Name: PCP DSCP Marking Policy Option (DSCP_POLICY) Number: TBA (IANA); mandatory to process Purpose: Associated a DSCP re-marking policy with a mapping Valid for Opcodes: MAP, PEER Length: 0x04 May appear in: both request and response Maximum occurrences: 1 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DSCP_POLICY | Reserved | 0x04 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |DIR| Int DSCP | Ext DSCP | 00...00 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ DIR : Indicates the direction: 0 Inbound 1 Outbound 2 Both Int DSCP: Indicates the DSCP value in the customer-faced interface. 0x3F is used to indicate ANY value. Ext DSCP: Indicates the DSCP value in the Internet-faced interface. 0x3F is used to indicate ANY value. Figure 2: DSCP Marking option 4. CAPABILITY The CAPABILITY option (Code: TBA, Figure 3) is used by a PCP Server to indicate to a requesting PCP Client the capabilities it supports with regards to port forwarding operations. Several Capability options MAY be conveyed in the same PCP response message if several functions are co-located in the same PCP-controlled device (e.g., NAT44 and NAT64, NAT44 and ports set assignment capability, etc.). This option, when received from a PCP Server, is used by a PCP Client to constraint the content of its requests and therefore avoid errors. Boucadair, et al. Expires October 27, 2012 [Page 5] Internet-Draft Extensions to PCP April 2012 This Option: Option Name: PCP Capabilities Option (CAPABILITY) Number: TBA (IANA) Purpose: Retrieve the capabilities of a PCP-controlled device Valid for Opcodes: can be returned in a error message Length: 0x01 May appear in: both request and response Maximum occurrences: None 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CAPABILITY | Reserved | 0x01 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |F T P A S C I O| 00...00 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Capability option Below is provided a description of the F, T, P, A, S, C, I and O bits: Name Description ---- ---------------------------------------------------------------- F This bit indicates the address family of the source address issued by internal hosts T This bit indicates the address family of the source address of the packets forwarded in the external side of the PCP-controlled device P This bit indicates whether the source port number is translated or not. A This bit indicates whether the source IP address is translated or not. S This bit indicates whether the controlled device supports the ability to assign a set or ports C This bit indicates whether the PCP-controlled devices inspects the received packets and if it can block them I This bit indicates whether incoming packets are rejected unless an explicit rule is enforced in the PCP-controlled device O This bit indicates whether outbound packets are inspected or not before being granted to leave the internal realm. The value of the F, T, P, A, S, C, I and O bits are as follows: Boucadair, et al. Expires October 27, 2012 [Page 6] Internet-Draft Extensions to PCP April 2012 Position Name Meaning -------- ------------------ ------------------------------ 1 From (F) 0=from IPv4, 1=from IPv6 2 To (T) 0=to IPv4, 1=to IPv6 3 Port-Xlate (P) 1=translated, 0=not translated 4 Addr-Xlate (A) 1=translated, 0=not translated 5 Port-Set (S) 1=enabled, 0=not supported 6 Packet-Control (C) 1=enabled, 0=not supported 7 Direction-Out (I) 1=enabled, 0=disabled 8 Direction-In (O) 1=enabled, 0=disabled A stateless NAT64 [RFC6145] would have the following values: From=0 (IPv4) To=1 (IPv6) Port-Xlate=0 (No) Addr-Xlate=1 (Yes) Port-Set=0 (No) Packet-control=0 (No) Direction-out (0) (No) Direction-In=0 (No) A stateful NAT64 [RFC6146] would have the following values: From=0 (IPv4) To=1 (IPv6) Port-Xlate=1 (Yes) Addr-Xlate=1 (Yes) Port-Set=0 (No) Packet-control=0 (No) Direction-out (0) (No) Direction-In=0 (No) A NAT44 would be characterized as follows: Boucadair, et al. Expires October 27, 2012 [Page 7] Internet-Draft Extensions to PCP April 2012 From=0 (IPv4) To=0 (IPv4) Port-Xlate=1 (Yes) Addr-Xlate=1 (Yes) Port-Set=0 (No) Packet-control=0 (No) Direction-out (0) (No) Direction-In=0 (No) 5. REPORT The Report PCP Option (Code TBA, Figure 4) is used by a PCP Client to report a set of useful information to the PCP Server. Several Report Options with distinct Report Sub-Code values MAY be conveyed in the same PCP message. Only report data associated with the PCP Server to which this option is sent MUST be included in a Report Option. This option can be used for troubleshooting or diagnose purposes. This Option: Option Name: PCP Report Option (REPORT) Number: TBA (IANA) Purpose: Send a set of report data Valid for Opcodes: MAP Length: Variable May appear in: both request and response Maximum occurrences: Multiple 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SCOPE | Reserved | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Report Sub-Code | 00...00 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Report Data | : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Report Option The following Report Sub-Code values are defined: Boucadair, et al. Expires October 27, 2012 [Page 8] Internet-Draft Extensions to PCP April 2012 Position Meaning -------- ------------------------------------------------------------ 0x00 Time since last reboot/boot 0x01 Count of transmitted PCP messages to the PCP Server since last boot 0x02 Count of retransmitted PCP messages to the PCP Server since last boot 0x03 Count of received PCP Error messages from the PCP Server 6. CLIENT_IDENTIFIER PCP CLIENT_ID (Code TBA, Figure 5) is a token randomly [RFC4086] generated by the PCP Client. Only one CLIENT_ID Option MUST be present in a PCP message. The PCP Client and PCP Server MUST store the value included in this Option in a PCP MAP request. o The CLIENT_ID MUST be generated by the PCP Client and not the PCP Server; o Upon change of the IP address of the PCP Client (or a third party on behalf of which a mapping has been created), the CLIENT_ID is used to update related mappings (e.g., PCP MAP delete request and PCP MAP create request); o The same CLIENT_ID MUST be used for all requested mappings, unless a new CLIENT_ID is generated by the PCP Client (e.g., reboot, OS crash, etc.); o The CLIENT_ID is stored by the PCP Server for all mappings (persistent storage); Boucadair, et al. Expires October 27, 2012 [Page 9] Internet-Draft Extensions to PCP April 2012 This Option: Option Name: PCP Client Identifier Option (CLIENT_ID) Number: TBA (IANA); mandatory to process option Purpose: Associate an identifier with the mappings Valid for Opcodes: MAP Length: Variable May appear in: both request and response Maximum occurrences: 1 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CLIENT_ID | Reserved | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Client Identifier | : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: CLIENT_ID PCP Option The length of the CLIENT_ID is encoded in the Length field in bytes. The length of the CLIENT_ID MUST be at least 4 bytes and MUST NOT exceed 16 bytes. The RECOMMENDED value is 16 bytes so as to have a robust random CLIENT_ID. If a CLIENT_ID longer than 16 bytes or shorter than 4 bytes is received, the PCP Server MUST issue a PCP Error message with an error cause equal to "Invalid Client-ID". For sanity checks, a PCP Server maintains the same CLIENT_ID value (which is used in the latest PCP request) for a given PCP Client for all mappings associated with the same internal IP address belonging to the same subscriber. Indeed, the PCP Server maintains an additional identifier denoted as subscriber-Id. A subscriber-is can be an IP address, IPv6 prefix or a subscriber identifier configured locally. 7. Security Considerations Security considerations discussed in [I-D.ietf-pcp-base] must be considered. The use of CLIENT_ID option allows to soften issues related to stale mappings. Boucadair, et al. Expires October 27, 2012 [Page 10] Internet-Draft Extensions to PCP April 2012 8. IANA Considerations The following PCP Option Codes are to be allocated: DESCRIPTION DSCP_POLICY: The "O" bit MUST be set to 1. CAPABILITY REPORT CLIENT_IDENTIFIER: The "O" bit MUST be set to 1. 9. Normative References [I-D.ietf-pcp-base] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. Selkirk, "Port Control Protocol (PCP)", draft-ietf-pcp-base-24 (work in progress), March 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, June 2005. [RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation Algorithm", RFC 6145, April 2011. [RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", RFC 6146, April 2011. Authors' Addresses Mohamed Boucadair France Telecom Rennes, 35000 France Email: mohamed.boucadair@orange.com Boucadair, et al. Expires October 27, 2012 [Page 11] Internet-Draft Extensions to PCP April 2012 Reinaldo Penno Cisco USA Email: repenno@cisco.com Dan Wing Cisco Systems, Inc. 170 West Tasman Drive San Jose, California 95134 USA Email: dwing@cisco.com Boucadair, et al. Expires October 27, 2012 [Page 12]