PCP Working Group M. Boucadair Internet-Draft France Telecom Intended status: Standards Track R. Penno Expires: March 21, 2013 D. Wing Cisco September 17, 2012 Retrieving the Capabilities of a PCP-controlled Device draft-boucadair-pcp-capability-00 Abstract This document extends Port Control Protocol (PCP) with the ability to retrieve the capabilities of PCP-controlled device: CAPABILITY Option. 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 March 21, 2013. 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 Boucadair, et al. Expires March 21, 2013 [Page 1] Internet-Draft CAPABILITY September 2012 publication of this document. Please review these documents 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. CAPABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. Normative References . . . . . . . . . . . . . . . . . . . 6 5.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Boucadair, et al. Expires March 21, 2013 [Page 2] Internet-Draft CAPABILITY September 2012 1. Introduction This document extends the base PCP [I-D.ietf-pcp-base] with a new feature to discover the capabilities of a PCP-controlled device. Retrieving the capabilities of a PCP-controlled device would allow to avoid error, provide a hint why some applications fails, help select the OpCode to issue, etc. This option can be elected to be defined as a new OpCode. This option has been defined first in [I-D.boucadair-pcp-extensions]. 2. CAPABILITY The CAPABILITY option (Code: TBA, Figure 1) 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 March 21, 2013 [Page 3] Internet-Draft CAPABILITY September 2012 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This Option: Option Name: PCP Capabilities Option (CAPABILITY) Number: TBA (IANA) Purpose: Retrieve the capabilities of a PCP-controlled device Valid for Opcodes: ANNOUNCE, MAP, PEER Length: 0x01 May appear in: both request and response Maximum occurrences: None Figure 1: 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 March 21, 2013 [Page 4] Internet-Draft CAPABILITY September 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 March 21, 2013 [Page 5] Internet-Draft CAPABILITY September 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) An A+P Port Range Router [RFC6346] would be characterized as follows: From=0 (IPv4) To=0 (IPv4) Port-Xlate=0 (No) Addr-Xlate=0 (No) Port-Set=1 (Yes) Packet-control=0 (No) Direction-out (0) (No) Direction-In=0 (No) 3. Security Considerations Security considerations discussed in [I-D.ietf-pcp-base] must be considered. 4. IANA Considerations The following PCP Option Code are to be allocated: CAPABILITY 5. References 5.1. 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-26 (work in progress), June 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation Boucadair, et al. Expires March 21, 2013 [Page 6] Internet-Draft CAPABILITY September 2012 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. 5.2. Informative References [I-D.boucadair-pcp-extensions] Boucadair, M., Penno, R., and D. Wing, "Some Extensions to Port Control Protocol (PCP)", draft-boucadair-pcp-extensions-03 (work in progress), April 2012. [RFC6346] Bush, R., "The Address plus Port (A+P) Approach to the IPv4 Address Shortage", RFC 6346, August 2011. Authors' Addresses Mohamed Boucadair France Telecom Rennes, 35000 France Email: mohamed.boucadair@orange.com 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 March 21, 2013 [Page 7]