--- 1/draft-ietf-ipwave-ipv6-over-80211ocb-26.txt 2018-09-14 07:13:54.525045024 -0700 +++ 2/draft-ietf-ipwave-ipv6-over-80211ocb-27.txt 2018-09-14 07:13:54.601046841 -0700 @@ -1,26 +1,26 @@ IPWAVE Working Group A. Petrescu Internet-Draft CEA, LIST Intended status: Standards Track N. Benamar -Expires: March 11, 2019 Moulay Ismail University +Expires: March 18, 2019 Moulay Ismail University J. Haerri Eurecom J. Lee Sangmyung University T. Ernst YoGoKo - September 7, 2018 + September 14, 2018 Transmission of IPv6 Packets over IEEE 802.11 Networks operating in mode Outside the Context of a Basic Service Set (IPv6-over-80211-OCB) - draft-ietf-ipwave-ipv6-over-80211ocb-26 + draft-ietf-ipwave-ipv6-over-80211ocb-27 Abstract In order to transmit IPv6 packets on IEEE 802.11 networks running outside the context of a basic service set (OCB, earlier "802.11p") there is a need to define a few parameters such as the supported Maximum Transmission Unit size on the 802.11-OCB link, the header format preceding the IPv6 header, the Type value within it, and others. This document describes these parameters for IPv6 and IEEE 802.11-OCB networks; it portrays the layering of IPv6 on 802.11-OCB @@ -35,21 +35,21 @@ 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 https://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 11, 2019. + This Internet-Draft will expire on March 18, 2019. Copyright Notice Copyright (c) 2018 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -57,21 +57,21 @@ 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. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 4 - 4. IPv6 over 802.11-OCB . . . . . . . . . . . . . . . . . . . . 5 + 4. IPv6 over 802.11-OCB . . . . . . . . . . . . . . . . . . . . 4 4.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 5 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 5 4.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 5 4.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 7 4.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 7 4.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 7 4.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 7 4.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 7 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 @@ -84,28 +84,26 @@ 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 9.2. Informative References . . . . . . . . . . . . . . . . . 14 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 15 Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 24 Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 24 Appendix D. Changes Needed on a software driver 802.11a to become a 802.11-OCB driver . . . 28 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 29 Appendix F. Design Considerations . . . . . . . . . . . . . . . 30 F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 30 - F.2. Reliability Requirements . . . . . . . . . . . . . . . . 31 - F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 31 - Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 32 - Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 32 - H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 33 - H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 36 - Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 38 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 + Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31 + Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 31 + H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 32 + H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 34 + Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 36 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37 1. Introduction This document describes the transmission of IPv6 packets on IEEE Std 802.11-OCB networks [IEEE-802.11-2016] (a.k.a "802.11p" see Appendix B, Appendix C and Appendix D). This involves the layering of IPv6 networking on top of the IEEE 802.11 MAC layer, with an LLC layer. Compared to running IPv6 over the Ethernet MAC layer, there is no modification expected to IEEE Std 802.11 MAC and Logical Link sublayers: IPv6 works fine directly over 802.11-OCB too, with an LLC @@ -139,29 +137,28 @@ "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a computer situated in a vehicle such as an automobile, bicycle, or similar. It has at least one IP interface that runs in mode OCB of 802.11, and that has an "OBU" transceiver. See the definition of the term "OBU" in section Appendix I. IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. An - IP-RSU has at least two distinct IP-enabled interfaces; at least one - interface is operated in mode OCB of IEEE 802.11 and is IP-enabled. - An IP-RSU is similar to a Wireless Termination Point (WTP), as - defined in [RFC5415], or an Access Point (AP), as defined in IEEE - documents, or an Access Network Router (ANR) defined in [RFC3753], - with one key particularity: the wireless PHY/MAC layer of at least - one of its IP-enabled interfaces is configured to operate in - 802.11-OCB mode. The IP-RSU communicates with the IP-OBU in the - vehicle over 802.11 wireless link operating in OCB mode. + IP-RSU has at least two distinct IP-enabled interfaces. An IP-RSU is + similar to a Wireless Termination Point (WTP), as defined in + [RFC5415], or an Access Point (AP), as defined in IEEE documents, or + an Access Network Router (ANR) defined in [RFC3753], with one key + particularity: the wireless PHY/MAC layer of at least one of its IP- + enabled interfaces is configured to operate in 802.11-OCB mode. The + IP-RSU communicates with the IP-OBU in the vehicle over 802.11 + wireless link operating in OCB mode. OCB (outside the context of a basic service set - BSS): A mode of operation in which a STA is not a member of a BSS and does not utilize IEEE Std 802.11 authentication, association, or data confidentiality. 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB attribute dot11OCBActivited is true. Note: compliance with standards and regulations set in different countries when using the 5.9GHz frequency band is required. @@ -389,21 +385,21 @@ 802.11-OCB does not provide any cryptographic protection, because it operates outside the context of a BSS (no Association Request/ Response, no Challenge messages). Any attacker can therefore just sit in the near range of vehicles, sniff the network (just set the interface card's frequency to the proper range) and perform attacks without needing to physically break any wall. Such a link is less protected than commonly used links (wired link or protected 802.11). The potential attack vectors are: MAC address spoofing, IP address - and session hijacking and privacy violation. + and session hijacking, and privacy violation Section 5.1. Within the IPsec Security Architecture [RFC4301], the IPsec AH and ESP headers [RFC4302] and [RFC4303] respectively, its multicast extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols can be used to protect communications. Further, the assistance of proper Public Key Infrastructure (PKI) protocols [RFC4210] is necessary to establish credentials. More IETF protocols are available in the toolbox of the IP security protocol designer. Certain ETSI protocols related to security protocols in Intelligent Transportation Systems are described in [ETSI-sec-archi]. @@ -415,22 +411,24 @@ address spoofing and IP address hijacking risks. A vehicle embarking an IP-OBU whose egress interface is 802.11-OCB may expose itself to eavesdropping and subsequent correlation of data; this may reveal data considered private by the vehicle owner; there is a risk of being tracked. In outdoors public environments, where vehicles typically circulate, the privacy risks are more important than in indoors settings. It is highly likely that attacker sniffers are deployed along routes which listen for IEEE frames, including IP packets, of vehicles passing by. For this reason, in the 802.11-OCB deployments, there is a strong necessity to use protection tools such - as dynamically changing MAC addresses. This may help mitigate - privacy risks to a certain level. + as dynamically changing MAC addresses Section 5.2, semantically + opaque Interface Identifiers and stable Interface Identifiers + Section 4.5. This may help mitigate privacy risks to a certain + level. 5.2. MAC Address Generation In 802.11-OCB networks, the MAC addresses MAY change during well defined renumbering events. In the moment the MAC address is changed on an 802.11-OCB interface all the Interface Identifiers of IPv6 addresses assigned to that interface MUST change. The policy dictating when the MAC address is changed on the 802.11-OCB interface is to-be-determined. For more information on @@ -647,33 +645,20 @@ draft-perkins-intarea-multicast-ieee802-03 (work in progress), July 2017. [IEEE-1609.2] "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access in Vehicular Environments (WAVE) -- Security Services for Applications and Management Messages. Example URL http://ieeexplore.ieee.org/document/7426684/ accessed on August 17th, 2017.". - [IEEE-1609.3] - "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access - in Vehicular Environments (WAVE) -- Networking Services. - Example URL http://ieeexplore.ieee.org/document/7458115/ - accessed on August 17th, 2017.". - - [IEEE-1609.4] - "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access - in Vehicular Environments (WAVE) -- Multi-Channel - Operation. Example URL - http://ieeexplore.ieee.org/document/7435228/ accessed on - August 17th, 2017.". - [IEEE-802.11-2016] "IEEE Standard 802.11-2016 - IEEE Standard for Information Technology - Telecommunications and information exchange between systems Local and metropolitan area networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. Status - Active Standard. Description retrieved freely on September 12th, 2017, at URL https://standards.ieee.org/findstds/ standard/802.11-2016.html". @@ -688,20 +673,24 @@ document freely available at URL http://standards.ieee.org/getieee802/ download/802.11p-2010.pdf retrieved on September 20th, 2013.". Appendix A. ChangeLog The changes are listed in reverse chronological order, most recent changes appearing at the top of the list. + -27: part 1 of addressing Human Rights review from IRTF. Removed + appendices F.2 and F.3. Shortened definition of IP-RSU. Removed + reference to 1609.4. A few other small changes, see diff. + -26: moved text from SLAAC section and from Design Considerations appendix about privacy into a new Privacy Condiderations subsection of the Security section; reformulated the SLAAC and IID sections to stress only LLs can use EUI-64; removed the "GeoIP" wireshark explanation; reformulated SLAAC and LL sections; added brief mention of need of use LLs; clarified text about MAC address changes; dropped pseudonym discussion; changed title of section describing examples of packet formats. -25: added a reference to 'IEEE Management Information Base', instead @@ -1285,23 +1275,21 @@ related to PHY, and thus has not much impact on the interface between the IP layer and the MAC layer. o In vehicular communications using 802.11-OCB links, there are strong privacy requirements with respect to addressing. While the 802.11-OCB standard does not specify anything in particular with respect to MAC addresses, in these settings there exists a strong need for dynamic change of these addresses (as opposed to the non- vehicular settings - real wall protection - where fixed MAC addresses do not currently pose some privacy risks). This is - further described in Section 5. A relevant function is described - in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE - 1609.4-2016 [IEEE-1609.4], clause 6.7. + further described in Section 5. Appendix D. Changes Needed on a software driver 802.11a to become a 802.11-OCB driver The 802.11p amendment modifies both the 802.11 stack's physical and MAC layers but all the induced modifications can be quite easily obtained by modifying an existing 802.11a ad-hoc stack. Conditions for a 802.11a hardware to be 802.11-OCB compliant: @@ -1410,84 +1398,20 @@ In case multiple 802.11-OCB NICs are present in one car, implicitely multiple vehicle IDs will be generated. Additionally, some software generates a random MAC address each time the computer boots; this constitutes an additional difficulty. A mechanim to uniquely identify a vehicle irrespectively to the multiplicity of NICs, or frequent MAC address generation, is necessary. -F.2. Reliability Requirements - - The dynamically changing topology, short connectivity, mobile - transmitter and receivers, different antenna heights, and many-to- - many communication types, make IEEE 802.11-OCB links significantly - different from other IEEE 802.11 links. Any IPv6 mechanism operating - on IEEE 802.11-OCB link must support strong link asymmetry, spatio- - temporal link quality, fast address resolution and transmission. - - IEEE 802.11-OCB strongly differs from other 802.11 systems to operate - outside of the context of a Basic Service Set. This means in - practice that IEEE 802.11-OCB does not rely on a Base Station for all - Basic Service Set management. In particular, IEEE 802.11-OCB shall - not use beacons. Any IPv6 mechanism requiring L2 services from IEEE - 802.11 beacons must support an alternative service. - - Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must - implement a mechanism for transmitter and receiver to converge to a - common channel. - - Authentication not being possible, IPv6 over IEEE 802.11-OCB must - implement an distributed mechanism to authenticate transmitters and - receivers without the support of a DHCP server. - - Time synchronization not being available, IPv6 over IEEE 802.11-OCB - must implement a higher layer mechanism for time synchronization - between transmitters and receivers without the support of a NTP - server. - - The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB - must disable management mechanisms requesting acknowledgements or - replies. - - The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE - 802.11-OCB should implement fast IPv6 mobility management mechanisms. - -F.3. Multiple interfaces - - There are considerations for 2 or more IEEE 802.11-OCB interface - cards per vehicle. For each vehicle taking part in road traffic, one - IEEE 802.11-OCB interface card could be fully allocated for Non IP - safety-critical communication. Any other IEEE 802.11-OCB may be used - for other type of traffic. - - The mode of operation of these other wireless interfaces is not - clearly defined yet. One possibility is to consider each card as an - independent network interface, with a specific MAC Address and a set - of IPv6 addresses. Another possibility is to consider the set of - these wireless interfaces as a single network interface (not - including the IEEE 802.11-OCB interface used by Non IP safety - critical communications). This will require specific logic to - ensure, for example, that packets meant for a vehicle in front are - actually sent by the radio in the front, or that multiple copies of - the same packet received by multiple interfaces are treated as a - single packet. Treating each wireless interface as a separate - network interface pushes such issues to the application layer. - - Certain privacy requirements imply that if these multiple interfaces - are represented by many network interface, a single renumbering event - shall cause renumbering of all these interfaces. If one MAC changed - and another stayed constant, external observers would be able to - correlate old and new values, and the privacy benefits of - randomization would be lost. - Appendix G. IEEE 802.11 Messages Transmitted in OCB mode For information, at the time of writing, this is the list of IEEE 802.11 messages that may be transmitted in OCB mode, i.e. when dot11OCBActivated is true in a STA: o The STA may send management frames of subtype Action and, if the STA maintains a TSF Timer, subtype Timing Advertisement; o The STA may send control frames, except those of subtype PS-Poll,