--- 1/draft-ietf-ipwave-ipv6-over-80211ocb-45.txt 2019-06-07 06:13:11.379817735 -0700 +++ 2/draft-ietf-ipwave-ipv6-over-80211ocb-46.txt 2019-06-07 06:13:11.447819446 -0700 @@ -1,53 +1,49 @@ IPWAVE Working Group N. Benamar Internet-Draft Moulay Ismail University Intended status: Standards Track J. Haerri -Expires: October 31, 2019 Eurecom +Expires: December 9, 2019 Eurecom J. Lee Sangmyung University T. Ernst YoGoKo - April 29, 2019 + June 7, 2019 -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-45 + Basic support for IPv6 over IEEE Std 802.11 Networks operating Outside + the Context of a Basic Service Set (IPv6-over-80211-OCB) + draft-ietf-ipwave-ipv6-over-80211ocb-46 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 how IPv6 (including addressing and - basic ND) can be used to communicate among nodes in range of one - another over IEEE 802.11-OCB. Optimizations and usage of IPv6 over - more complex scenarios is not covered and is subject of future work. + This document provides methods and settings, and describes + limitations, for using IPv6 to communicate among nodes in range of + one another over a single IEEE 802.11-OCB link with minimal change to + existing stacks. Optimizations and usage of IPv6 over more complex + scenarios is not covered and is subject of future work. 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 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 October 31, 2019. + This Internet-Draft will expire on December 9, 2019. Copyright Notice Copyright (c) 2019 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 @@ -57,74 +53,72 @@ 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 . . . . . . . . . . . . . . . . . . . . 4 4.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 4 - 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 5 - 4.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 5 - 4.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 7 - 4.4. Stateless Autoconfiguration . . . . . . . . . . . . . . . 7 - 4.5. Address Mapping . . . . . . . . . . . . . . . . . . . . . 8 - 4.5.1. Address Mapping -- Unicast . . . . . . . . . . . . . 8 - 4.5.2. Address Mapping -- Multicast . . . . . . . . . . . . 8 - 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 8 - 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 - 5.1. Privacy Considerations . . . . . . . . . . . . . . . . . 10 - 5.1.1. Privacy Risks of Meaningful info in Interface IDs . . 10 - 5.2. MAC Address and Interface ID Generation . . . . . . . . . 11 - 5.3. Pseudonym Handling . . . . . . . . . . . . . . . . . . . 11 - 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 - 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12 - 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 - 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 - 9.1. Normative References . . . . . . . . . . . . . . . . . . 13 - 9.2. Informative References . . . . . . . . . . . . . . . . . 16 - Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 17 - Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 28 - Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 28 - Appendix D. Changes Needed on a software driver 802.11a to - become a 802.11-OCB driver . . . 32 - Appendix E. Protocol Layering . . . . . . . . . . . . . . . . . 33 - Appendix F. Design Considerations . . . . . . . . . . . . . . . 34 - Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 34 - Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 35 - H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 36 - H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 38 - Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 40 - Appendix J. Neighbor Discovery (ND) Potential Issues in Wireless - Links . . . . . . . . . . . . . . . . . . . . . . . 41 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43 + 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 4 + 4.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 5 + 4.4. Stateless Autoconfiguration . . . . . . . . . . . . . . . 5 + 4.5. Address Mapping . . . . . . . . . . . . . . . . . . . . . 6 + 4.5.1. Address Mapping -- Unicast . . . . . . . . . . . . . 6 + 4.5.2. Address Mapping -- Multicast . . . . . . . . . . . . 6 + 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 7 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 + 5.1. Privacy Considerations . . . . . . . . . . . . . . . . . 8 + 5.1.1. Privacy Risks of Meaningful info in Interface IDs . . 9 + 5.2. MAC Address and Interface ID Generation . . . . . . . . . 9 + 5.3. Pseudonym Handling . . . . . . . . . . . . . . . . . . . 10 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 + 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 + 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 9.2. Informative References . . . . . . . . . . . . . . . . . 14 + Appendix A. 802.11p . . . . . . . . . . . . . . . . . . . . . . 16 + Appendix B. Aspects introduced by the OCB mode to 802.11 . . . . 16 + Appendix C. Changes Needed on a software driver 802.11a to + become a 802.11-OCB driver . . . 21 + Appendix D. Protocol Layering . . . . . . . . . . . . . . . . . 22 + Appendix E. Design Considerations . . . . . . . . . . . . . . . 23 + Appendix F. IEEE 802.11 Messages Transmitted in OCB mode . . . . 23 + Appendix G. Examples of Packet Formats . . . . . . . . . . . . . 23 + G.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 24 + G.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 27 + Appendix H. Extra Terminology . . . . . . . . . . . . . . . . . 29 + Appendix I. Neighbor Discovery (ND) Potential Issues in Wireless + Links . . . . . . . . . . . . . . . . . . . . . . . 30 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32 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 - layer. + This document provides a baseline with limitations for using IPv6 to + communicate among nodes in range of one another over a single IEEE + 802.11-OCB link [IEEE-802.11-2016] (a.k.a "802.11p" see Appendix A, + Appendix B and Appendix C) with minimal change to existing stacks. + This document describes the layering of IPv6 networking on top of the + IEEE Std 802.11 MAC layer or an IEEE Std 802.3 MAC layer with a frame + translation underneath. The resulting stack operates over 802.11-OCB + and provides at least P2P connectivity using IPv6 ND and link-local + addresses. ND Extensions and IPWAVE optimizations for vehicular + communications are not in scope. The expectation is that further + specs will elaborate for more complex vehicular networking scenarios. The IPv6 network layer operates on 802.11-OCB in the same manner as operating on Ethernet, but there are two kinds of exceptions: o Exceptions due to different operation of IPv6 network layer on - 802.11 than on Ethernet. To satisfy these exceptions, this - document describes an Ethernet Adaptation Layer between Ethernet - headers and 802.11 headers. The Ethernet Adaptation Layer is - described Section 4.2.1. The operation of IP on Ethernet is + 802.11 than on Ethernet. The operation of IP on Ethernet is described in [RFC1042], [RFC2464] . o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. This has impacts on security, privacy, subnet structure and movement detection. For security and privacy recommendations see Section 5 and Section 4.4. The subnet structure is described in Section 4.6. The movement detection on OCB links is not described in this document. In the published literature, many documents describe aspects and @@ -136,21 +130,21 @@ 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 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 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. + in section Appendix H. IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. It has at least two distinct IP-enabled interfaces; the wireless PHY/MAC layer of at least one of its IP-enabled interfaces is configured to operate in 802.11-OCB mode. An IP-RSU communicates with the IP-OBU in the vehicle over 802.11 wireless link operating in OCB mode. An IP-RSU is similar to an Access Network Router (ANR) defined in [RFC3753], and a Wireless Termination Point (WTP) defined in [RFC5415]. @@ -160,148 +154,83 @@ 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. 3. Communication Scenarios where IEEE 802.11-OCB Links are Used The IEEE 802.11-OCB Networks are used for vehicular communications, - as 'Wireless Access in Vehicular Environments'. The IP communication - scenarios for these environments have been described in several - documents; in particular, we refer the reader to - [I-D.ietf-ipwave-vehicular-networking], that lists some scenarios and - requirements for IP in Intelligent Transportation Systems. + as 'Wireless Access in Vehicular Environments'. In particular, we + refer the reader to [I-D.ietf-ipwave-vehicular-networking], that + lists some scenarios and requirements for IP in Intelligent + Transportation Systems. The link model is the following: STA --- 802.11-OCB --- STA. In - vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While - 802.11-OCB is clearly specified, and the use of IPv6 over such link - is not radically new, the operating environment (vehicular networks) - brings in new perspectives. + vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. All links + are assumed to be P2P and multiple links can be on one radio + interface. While 802.11-OCB is clearly specified, and a legacy IPv6 + stack can operate on such links, the use of the operating environment + (vehicular networks) brings in new perspectives. 4. IPv6 over 802.11-OCB 4.1. Maximum Transmission Unit (MTU) - The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It - is the same value as IPv6 packets on Ethernet links, as specified in - [RFC2464]. This value of the MTU respects the recommendation that - every link on the Internet must have a minimum MTU of 1280 octets - (stated in [RFC8200], and the recommendations therein, especially - with respect to fragmentation). + The default MTU for IP packets on 802.11-OCB is inherited from + RFC2464 and is 1500 octets. This value of the MTU respects the + recommendation that every link on the Internet must have a minimum + MTU of 1280 octets (stated in [RFC8200], and the recommendations + therein, especially with respect to fragmentation). 4.2. Frame Format IP packets MUST be transmitted over 802.11-OCB media as QoS Data - frames whose format is specified in IEEE 802.11(TM) -2016 + frames whose format is specified in IEEE 802.11 spec [IEEE-802.11-2016]. - The IPv6 packet transmitted on 802.11-OCB MUST be immediately - preceded by a Logical Link Control (LLC) header and an 802.11 header. - In the LLC header, and in accordance with the EtherType Protocol - Discrimination (EPD, see Appendix E), the value of the Type field - MUST be set to 0x86DD (IPv6). In the 802.11 header, the value of the - Subtype sub-field in the Frame Control field MUST be set to 8 (i.e. - 'QoS Data'); the value of the Traffic Identifier (TID) sub-field of - the QoS Control field of the 802.11 header MUST be set to binary 001 - (i.e. User Priority 'Background', QoS Access Category 'AC_BK'). + The IPv6 packet transmitted on 802.11-OCB are immediately preceded by + a Logical Link Control (LLC) header and an 802.11 header. In the LLC + header, and in accordance with the EtherType Protocol Discrimination + (EPD, see Appendix D), the value of the Type field MUST be set to + 0x86DD (IPv6). The mapping to the 802.11 data service MUST use a + 'priority' value of 1, which specifies the use of QoS with a + 'Background' user priority. To simplify the Application Programming Interface (API) between the operating system and the 802.11-OCB media, device drivers MAY - implement an Ethernet Adaptation Layer that translates Ethernet II - frames to the 802.11 format and vice versa. An Ethernet Adaptation - Layer is described in Section 4.2.1. - -4.2.1. Ethernet Adaptation Layer - - An 'adaptation' layer is inserted between a MAC layer and the - Networking layer. This is used to transform some parameters between - their form expected by the IP stack and the form provided by the MAC - layer. - - An Ethernet Adaptation Layer makes an 802.11 MAC look to IP - Networking layer as a more traditional Ethernet layer. At reception, - this layer takes as input the IEEE 802.11 header and the Logical-Link - Layer Control Header and produces an Ethernet II Header. At sending, - the reverse operation is performed. - - The operation of the Ethernet Adaptation Layer is depicted by the - double arrow in Figure 1. - - +------------------+------------+-------------+---------+-----------+ - | 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer| - +------------------+------------+-------------+---------+-----------+ - \ / \ / - --------------------------- -------- - \---------------------------------------------/ - ^ - | - 802.11-to-Ethernet Adaptation Layer - | - v - +---------------------+-------------+---------+ - | Ethernet II Header | IPv6 Header | Payload | - +---------------------+-------------+---------+ - - Figure 1: Operation of the Ethernet Adaptation Layer - - The Receiver and Transmitter Address fields in the 802.11 header MUST - contain the same values as the Destination and the Source Address - fields in the Ethernet II Header, respectively. The value of the - Type field in the LLC Header MUST be the same as the value of the - Type field in the Ethernet II Header. That value MUST be set to - 0x86DD (IPv6). - - The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. - - The placement of IPv6 networking layer on Ethernet Adaptation Layer - is illustrated in Figure 2. - - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | IPv6 | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Ethernet Adaptation Layer | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | 802.11 MAC | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | 802.11 PHY | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - Figure 2: Ethernet Adaptation Layer stacked with other layers - - (in the above figure, a 802.11 profile is represented; this is used - also for 802.11-OCB profile.) + implement IPv6 over Ethernet per RFC 2464 and then a frame + translation from 802.3 to 802.11 in order to minimize the code + changes. 4.3. Link-Local Addresses There are several types of IPv6 addresses [RFC4291], [RFC4193], that MAY be assigned to an 802.11-OCB interface. Among these types of addresses only the IPv6 link-local addresses MAY be formed using an EUI-64 identifier, in particular during transition time. If the IPv6 link-local address is formed using an EUI-64 identifier, then the mechanism of forming that address is the same mechanism as used to form an IPv6 link-local address on Ethernet links. This mechanism is described in section 5 of [RFC2464]. 4.4. Stateless Autoconfiguration - There are several types of IPv6 addresses [RFC4291], [RFC4193], that - MAY be assigned to an 802.11-OCB interface. This section describes - the formation of Interface Identifiers for IPv6 addresses of type - 'Global' or 'Unique Local'. For Interface Identifiers for IPv6 - address of type 'Link-Local' see Section 4.3. + The steps a host takes in deciding how to autoconfigure its + interfaces in IP version 6 are described in [RFC4862]. This section + describes the formation of Interface Identifiers for IPv6 addresses + of type 'Global' or 'Unique Local'. For Interface Identifiers for + IPv6 address of type 'Link-Local' see Section 4.3. - The Interface Identifier for an 802.11-OCB interface is formed using - the same rules as the Interface Identifier for an Ethernet interface; - the RECOMMENDED method for forming stable Interface Identifiers + The RECOMMENDED method for forming stable Interface Identifiers (IIDs) is described in [RFC8064]. The method of forming IIDs described in section 4 of [RFC2464] MAY be used during transition time, in particular for IPv6 link-local addresses. The bits in the Interface Identifier have no generic meaning and the identifier should be treated as an opaque value. The bits 'Universal' and 'Group' in the identifier of an 802.11-OCB interface are significant, as this is an IEEE link-layer address. The details of this significance are described in [RFC7136]. @@ -330,47 +259,47 @@ name, or logical interface name, that is decided by a local administrator. 4.5. Address Mapping Unicast and multicast address mapping MUST follow the procedures specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 4.5.1. Address Mapping -- Unicast - The procedure for mapping IPv6 unicast addresses into Ethernet link- - layer addresses is described in [RFC4861]. + This draft is scoped for AR and DAD per RFC 4861 [RFC4861]. 4.5.2. Address Mapping -- Multicast The multicast address mapping is performed according to the method specified in section 7 of [RFC2464]. The meaning of the value "3333" mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 of [RFC7042]. Transmitting IPv6 packets to multicast destinations over 802.11 links proved to have some performance issues [I-D.ietf-mboned-ieee802-mcast-problems]. These issues may be - exacerbated in OCB mode. Solutions for these problems SHOULD - consider the OCB mode of operation. + exacerbated in OCB mode.A Future improvement to this specification + SHOULD consider solutions for these problems. 4.6. Subnet Structure - A subnet is formed by the external 802.11-OCB interfaces of vehicles - that are in close range (not by their in-vehicle interfaces). A - Prefix List conceptual data structure ([RFC4861] section 5.1) is - maintained for each 802.11-OCB interface. + A subnet may be formed over 802.11-OCB interfaces of vehicles that + are in close range (not by their in-vehicle interfaces). A Prefix + List conceptual data structure ([RFC4861] section 5.1) is maintained + for each 802.11-OCB interface. - The subnet structure on which the Neighbor Discovery protocol (ND) on - OCB works ok is a single-link subnet; the status of ND operation on a - subnet that covers multiple OCB links that repeat the signal at PHY - layer, or the messages at MAC layer, is unknown. + An IPv6 subnet on which Neighbor Discovery protocol (ND) can be + mapped on an OCB network iff all nodes share a single broadcast + Domain, which is generally the case for P2P OCB links; The extension + to IPv6 ND operating on a subnet that covers multiple OCB links and + not fully overlapping (NBMA) is not in scope. The structure of this subnet is ephemeral, in that it is strongly influenced by the mobility of vehicles: the hidden terminal effects appear; the 802.11 networks in OCB mode may be considered as 'ad-hoc' networks with an addressing model as described in [RFC5889]. On another hand, the structure of the internal subnets in each car is relatively stable. As recommended in [RFC5889], when the timing requirements are very strict (e.g. fast drive through IP-RSU coverage), no on-link subnet @@ -378,32 +307,33 @@ cases, the exclusive use of IPv6 link-local addresses is RECOMMENDED. Additionally, even if the timing requirements are not very strict (e.g. the moving subnet formed by two following vehicles is stable, a fixed IP-RSU is absent), the subnet is disconnected from the Internet (a default route is absent), and the addressing peers are equally qualified (impossible to determine that some vehicle owns and distributes addresses to others) the use of link-local addresses is RECOMMENDED. - The baseline Neighbor Discovery protocol (ND) [RFC4861] MUST be used - over 802.11-OCB links. Transmitting ND packets may prove to have - some performance issues. These issues may be exacerbated in OCB - mode. Solutions for these problems SHOULD consider the OCB mode of - operation. The best of current knowledge indicates the kinds of - issues that may arise with ND in OCB mode; they are described in - Appendix J. + The baseline Neighbor Discovery protocol (ND) [RFC4861] MUST be + supported over 802.11-OCB links. Transmitting ND packets may prove + to have some performance issues see Section 4.5.2, and Appendix I. + These issues may be exacerbated in OCB mode. Solutions for these + problems SHOULD consider the OCB mode of operation. Future solutions + to OCB should consider solutions for avoiding broadcast. The best of + current knowledge indicates the kinds of issues that may arise with + ND in OCB mode; they are described in Appendix I. - Protocols like Mobile IPv6 [RFC6275] and DNAv6 [RFC6059], which - depend on timely movement detection, might need additional tuning - work to handle the lack of link-layer notifications during handover. - This is for further study. + Protocols like Mobile IPv6 [RFC6275] , [RFC3963] and DNAv6 [RFC6059], + which depend on timely movement detection, might need additional + tuning work to handle the lack of link-layer notifications during + handover. This is for further study. 5. Security Considerations Any security mechanism at the IP layer or above that may be carried out for the general case of IPv6 may also be carried out for IPv6 operating over 802.11-OCB. The OCB operation is stripped off of all existing 802.11 link-layer security mechanisms. There is no encryption applied below the network layer running on 802.11-OCB. At application layer, the IEEE @@ -415,31 +345,29 @@ 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 Section 5.1. + and session hijacking, and privacy violation Section 5.1. A previous + work at SAVI WG presents some threats [RFC6959], while SeND presented + in [RFC3971] and [RFC3972] is a solution against address theft but it + is complex and not deployed. - 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]. + 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]. 5.1. Privacy Considerations As with all Ethernet and 802.11 interface identifiers ([RFC7721]), the identifier of an 802.11-OCB interface may involve privacy, MAC 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 @@ -470,21 +398,21 @@ 5.2. MAC Address and Interface ID 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 the motivation of this policy please refer to the privacy discussion - in Appendix C. + in Appendix B. A 'randomized' MAC address has the following characteristics: o Bit "Local/Global" set to "locally admninistered". o Bit "Unicast/Multicast" set to "Unicast". o The 46 remaining bits are set to a random value, using a random number generator that meets the requirements of [RFC4086]. @@ -541,20 +469,23 @@ Michelle Wetterwald contributed extensively the MTU discussion, offered the ETSI ITS perspective, and reviewed other parts of the document. 8. Acknowledgements The authors would like to thank Alexandre Petrescu for initiating this work and for being the lead author until the version 43 of this draft. + The authors would like to thank Pascal Thubert for reviewing, + proofreading and suggesting modifications of this document. + The authors would like to thank Witold Klaudel, Ryuji Wakikawa, Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 't Velt, Katrin Sjoberg, Roland Bless, Tijink Jasja, Kevin Smith, @@ -596,25 +527,34 @@ . [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, May 2000, . [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, . + [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. + Thubert, "Network Mobility (NEMO) Basic Support Protocol", + RFC 3963, DOI 10.17487/RFC3963, January 2005, + . + [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, DOI 10.17487/RFC3971, March 2005, . + [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", + RFC 3972, DOI 10.17487/RFC3972, March 2005, + . + [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, DOI 10.17487/RFC4086, June 2005, . [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, . [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, @@ -637,20 +577,25 @@ [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", RFC 4303, DOI 10.17487/RFC4303, December 2005, . [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, September 2007, . + [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless + Address Autoconfiguration", RFC 4862, + DOI 10.17487/RFC4862, September 2007, + . + [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast Extensions to the Security Architecture for the Internet Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, . [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, Ed., "Control And Provisioning of Wireless Access Points (CAPWAP) Protocol Specification", RFC 5415, DOI 10.17487/RFC5415, March 2009, . @@ -661,20 +606,25 @@ [RFC6059] Krishnan, S. and G. Daley, "Simple Procedures for Detecting Network Attachment in IPv6", RFC 6059, DOI 10.17487/RFC6059, November 2010, . [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 2011, . + [RFC6959] McPherson, D., Baker, F., and J. Halpern, "Source Address + Validation Improvement (SAVI) Threat Scope", RFC 6959, + DOI 10.17487/RFC6959, May 2013, + . + [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and IETF Protocol and Documentation Usage for IEEE 802 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, October 2013, . [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, February 2014, . [RFC7217] Gont, F., "A Method for Generating Semantically Opaque @@ -710,21 +660,21 @@ Security; ITS communications security architecture and security management, November 2016. Downloaded on September 9th, 2017, freely available from ETSI website at URL http://www.etsi.org/deliver/ etsi_ts/102900_102999/102940/01.02.01_60/ ts_102940v010201p.pdf". [I-D.ietf-ipwave-vehicular-networking] Jeong, J., "IP Wireless Access in Vehicular Environments (IPWAVE): Problem Statement and Use Cases", draft-ietf- - ipwave-vehicular-networking-08 (work in progress), March + ipwave-vehicular-networking-09 (work in progress), May 2019. [I-D.ietf-mboned-ieee802-mcast-problems] Perkins, C., McBride, M., Stanley, D., Kumari, W., and J. Zuniga, "Multicast Considerations over IEEE 802 Wireless Media", draft-ietf-mboned-ieee802-mcast-problems-05 (work in progress), April 2019. [IEEE-1609.2] "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access @@ -765,544 +715,33 @@ 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, Amendment 6: Wireless Access in Vehicular Environments; 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. - - -43: removed the SHOULD 48bit of a MAC address, just stay silent - about it; corrected 'global' address to 'Globally Reachable address'; - added a paragraph scoping IPv6-over-OCB ND to work ok on single-link - subnets. - - -42: removed 118 len IID; points to 'other documents' for the length - of Interface ID; removed 'directly using' phrase for LLs in a subnet. - - -41: updated a reference from draft-ietf-ipwave-vehicular-networking- - survey to draft-ietf-ipwave-vehicular-networking; clarified the link- - local text by eliminating link-local addresses and prefixes - altogether and referring to RFC4861 which requires the prefixes; - added a statement about the subnet being a not multi-link subnet. - - -40: added a phrase in appendix to further described a condition - where ND on OCB may not work; that phrase contains a placeholder; the - placeholder is 'TBD' (To Be Defined). - - -39: removed a reference to an expired draft trying to update the - IPv6-over-Ethernet spec 'RFC2464bis'; added text in the subnet - structure section saying nodes MUST be able to communicate directly - using their link-local addresses. - - -38: removed the word "fe80::/10". - - -37: added a section about issues on ND wireless; added the qualifier - 'baseline' to using ND on 802.11-OCB; improved the description of the - reference to 802.11-2016 document, with a qualifier about the - difficulty of accessing it, even though it is free. - - -36: removed a phrase about the IID formation and MAC generation, but - left in the section 5.2 that describes how it happens. - - -35: addressing the the intarea review: clarified a small apparent - contradiction between two parts of text that use the old MAC-based - IIDs (clarified by using qualifiers from each other: transition time, - and ll addresses); sequenced closer the LL and Stateless Autoconf - sections, instead of spacing them; shortened the paragraph of Opaque - IIDs; moved the privacy risks of in-clear IIDs in the security - section; removed a short phrase duplicating the idea of privacy - risks; added third time a reference to the 802.11-2016 document; used - 'the hidden terminal' text; updated the Terminology section with new - BCP-14 text 'MUST' to include RFC8174. - - -33: substituted 'movement detection' for 'handover behaviour' in - introductory text; removed redundant phrase referring to Security - Considerations section; removed the phrase about forming mechanisms - being left out, as IP is not much concerned about L2 forming; moved - the Pseudonym section from main section to end of Security - Considerations section (and clarified 'concurrently'); capitalized - SHOULD consider OCB in WiFi multicast problems, and referred to more - recent I-D on topic; removed several phrases in a paragraph about - oui.txt and MAC presence in IPv6 address, as they are well known - info, but clarified the example of privacy risk of Company ID in MAC - addresses in public roads; clarified that ND MUST be used over - 802.11-OCB. - - -32: significantly shortened the relevant ND/OCB paragraph. It now - just states ND is used over OCB, w/o detailing. - - -31: filled in the section titled "Pseudonym Handling"; removed a - 'MAY NOT' phrase about possibility of having other prefix than the LL - on the link between cars; shortened and improved the paragraph about - Mobile IPv6, now with DNAv6; improved the ND text about ND - retransmissions with relationship to packet loss; changed the title - of an appendix from 'EPD' to 'Protocol Layering'; improved the - 'Aspects introduced by OCB' appendix with a few phrases about the - channel use and references. - - -30: a clarification on the reliability of ND over OCB and over - 802.11. - - -29: - - o - - -28: - - o Created a new section 'Pseudonym Handling'. - - o removed the 'Vehicle ID' appendix. - - o improved the address generation from random MAC address. - - o shortened Term IP-RSU definition. - - o removed refs to two detail Clauses in IEEE documents, kept just - these latter. - - -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 - of just 'Management Information Base'; added ref to further - appendices in the introductory phrases; improved text for IID - formation for SLAAC, inserting recommendation for RFC8064 before - RFC2464. - - From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- - ipv6-over-80211ocb-24 - - o Nit: wrote "IPWAVE Working Group" on the front page, instead of - "Network Working Group". - - o Addressed the comments on 6MAN: replaced a sentence about ND - problem with "is used over 802.11-OCB". - - From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- - ipv6-over-80211ocb-23 - - o No content modifications, but check the entire draft chain on - IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. - - From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- - ipv6-over-80211ocb-22 - - o Corrected typo, use dash in "802.11-OCB" instead of space. - - o Improved the Frame Format section: MUST use QoSData, specify the - values within; clarified the Ethernet Adaptation Layer text. - - From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- - ipv6-over-80211ocb-21 - - o Corrected a few nits and added names in Acknowledgments section. - - o Removed unused reference to old Internet Draft tsvwg about QoS. - - From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- - ipv6-over-80211ocb-20 - - o Reduced the definition of term "802.11-OCB". - - o Left out of this specification which 802.11 header to use to - transmit IP packets in OCB mode (QoS Data header, Data header, or - any other). - - o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is - using' an Ethernet Adaptation Layer. - - From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- - ipv6-over-80211ocb-19 - - o Removed the text about fragmentation. - - o Removed the mentioning of WSMP and GeoNetworking. - - o Removed the explanation of the binary representation of the - EtherType. - - o Rendered normative the paragraph about unicast and multicast - address mapping. - - o Removed paragraph about addressing model, subnet structure and - easiness of using LLs. - - o Clarified the Type/Subtype field in the 802.11 Header. - - o Used RECOMMENDED instead of recommended, for the stable interface - identifiers. - - From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- - ipv6-over-80211ocb-18 - - o Improved the MTU and fragmentation paragraph. - - From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- - ipv6-over-80211ocb-17 - - o Susbtituted "MUST be increased" to "is increased" in the MTU - section, about fragmentation. - - From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- - ipv6-over-80211ocb-16 - - o Removed the definition of the 'WiFi' term and its occurences. - Clarified a phrase that used it in Appendix C "Aspects introduced - by the OCB mode to 802.11". - - o Added more normative words: MUST be 0x86DD, MUST fragment if size - larger than MTU, Sequence number in 802.11 Data header MUST be - increased. - - From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- - ipv6-over-80211ocb-15 - - o Added normative term MUST in two places in section "Ethernet - Adaptation Layer". - - From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- - ipv6-over-80211ocb-14 - - o Created a new Appendix titled "Extra Terminology" that contains - terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them - are used in the main Terminology section. - - o Added two paragraphs explaining that ND and Mobile IPv6 have - problems working over 802.11-OCB, yet their adaptations is not - specified in this document. - - From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- - ipv6-over-80211ocb-13 - - o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" - throughout and improved OBU-related definitions in the Terminology - section. - - From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- - ipv6-over-80211ocb-12 - - o Improved the appendix about "MAC Address Generation" by expressing - the technique to be an optional suggestion, not a mandatory - mechanism. - - From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- - ipv6-over-80211ocb-11 - - o Shortened the paragraph on forming/terminating 802.11-OCB links. - - o Moved the draft tsvwg-ieee-802-11 to Informative References. - - From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- - ipv6-over-80211ocb-10 - - o Removed text requesting a new Group ID for multicast for OCB. - - o Added a clarification of the meaning of value "3333" in the - section Address Mapping -- Multicast. - - o Added note clarifying that in Europe the regional authority is not - ETSI, but "ECC/CEPT based on ENs from ETSI". - - o Added note stating that the manner in which two STAtions set their - communication channel is not described in this document. - - o Added a time qualifier to state that the "each node is represented - uniquely at a certain point in time." - - o Removed text "This section may need to be moved" (the "Reliability - Requirements" section). This section stays there at this time. - - o In the term definition "802.11-OCB" added a note stating that "any - implementation should comply with standards and regulations set in - the different countries for using that frequency band." - - o In the RSU term definition, added a sentence explaining the - difference between RSU and RSRU: in terms of number of interfaces - and IP forwarding. - - o Replaced "with at least two IP interfaces" with "with at least two - real or virtual IP interfaces". - - o Added a term in the Terminology for "OBU". However the definition - is left empty, as this term is defined outside IETF. - - o Added a clarification that it is an OBU or an OBRU in this phrase - "A vehicle embarking an OBU or an OBRU". - - o Checked the entire document for a consistent use of terms OBU and - OBRU. - - o Added note saying that "'p' is a letter identifying the - Ammendment". - - o Substituted lower case for capitals SHALL or MUST in the - Appendices. - - o Added reference to RFC7042, helpful in the 3333 explanation. - Removed reference to individual submission draft-petrescu-its- - scenario-reqs and added reference to draft-ietf-ipwave-vehicular- - networking-survey. - - o Added figure captions, figure numbers, and references to figure - numbers instead of 'below'. Replaced "section Section" with - "section" throughout. - - o Minor typographical errors. - - From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- - ipv6-over-80211ocb-09 - - o Significantly shortened the Address Mapping sections, by text - copied from RFC2464, and rather referring to it. - - o Moved the EPD description to an Appendix on its own. - - o Shortened the Introduction and the Abstract. - - o Moved the tutorial section of OCB mode introduced to .11, into an - appendix. - - o Removed the statement that suggests that for routing purposes a - prefix exchange mechanism could be needed. - - o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, - MIP/NEMO and oDAD; they were referred in the handover discussion - section, which is out. - - o Updated a reference from individual submission to now a WG item in - IPWAVE: the survey document. - - o Added term definition for WiFi. - - o Updated the authorship and expanded the Contributors section. - - o Corrected typographical errors. - - From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- - ipv6-over-80211ocb-08 - - o Removed the per-channel IPv6 prohibition text. - - o Corrected typographical errors. - - From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- - ipv6-over-80211ocb-07 - - o Added new terms: OBRU and RSRU ('R' for Router). Refined the - existing terms RSU and OBU, which are no longer used throughout - the document. - - o Improved definition of term "802.11-OCB". - - o Clarified that OCB does not "strip" security, but that the - operation in OCB mode is "stripped off of all .11 security". - - o Clarified that theoretical OCB bandwidth speed is 54mbits, but - that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. - - o Corrected typographical errors, and improved some phrasing. - - From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- - ipv6-over-80211ocb-06 - - o Updated references of 802.11-OCB document from -2012 to the IEEE - 802.11-2016. - - o In the LL address section, and in SLAAC section, added references - to 7217 opaque IIDs and 8064 stable IIDs. - - From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- - ipv6-over-80211ocb-05 - - o Lengthened the title and cleanded the abstract. - - o Added text suggesting LLs may be easy to use on OCB, rather than - GUAs based on received prefix. - - o Added the risks of spoofing and hijacking. - - o Removed the text speculation on adoption of the TSA message. - - o Clarified that the ND protocol is used. - - o Clarified what it means "No association needed". - - o Added some text about how two STAs discover each other. - - o Added mention of external (OCB) and internal network (stable), in - the subnet structure section. - - o Added phrase explaining that both .11 Data and .11 QoS Data - headers are currently being used, and may be used in the future. - - o Moved the packet capture example into an Appendix Implementation - Status. - - o Suggested moving the reliability requirements appendix out into - another document. - - o Added a IANA Consiserations section, with content, requesting for - a new multicast group "all OCB interfaces". - - o Added new OBU term, improved the RSU term definition, removed the - ETTC term, replaced more occurences of 802.11p, 802.11-OCB with - 802.11-OCB. - - o References: - - * Added an informational reference to ETSI's IPv6-over- - GeoNetworking. - - * Added more references to IETF and ETSI security protocols. - - * Updated some references from I-D to RFC, and from old RFC to - new RFC numbers. - - * Added reference to multicast extensions to IPsec architecture - RFC. - - * Added a reference to 2464-bis. - - * Removed FCC informative references, because not used. - - o Updated the affiliation of one author. - - o Reformulation of some phrases for better readability, and - correction of typographical errors. - - From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- - ipv6-over-80211ocb-04 - - o Removed a few informative references pointing to Dx draft IEEE - 1609 documents. - - o Removed outdated informative references to ETSI documents. - - o Added citations to IEEE 1609.2, .3 and .4-2016. - - o Minor textual issues. - - From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- - ipv6-over-80211ocb-03 - - o Keep the previous text on multiple addresses, so remove talk about - MIP6, NEMOv6 and MCoA. - - o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. - - o Clarified the figure showing Infrastructure mode and OCB mode side - by side. - - o Added a reference to the IP Security Architecture RFC. - - o Detailed the IPv6-per-channel prohibition paragraph which reflects - the discussion at the last IETF IPWAVE WG meeting. - - o Added section "Address Mapping -- Unicast". - - o Added the ".11 Trailer" to pictures of 802.11 frames. - - o Added text about SNAP carrying the Ethertype. - - o New RSU definition allowing for it be both a Router and not - necessarily a Router some times. - - o Minor textual issues. - - From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- - ipv6-over-80211ocb-02 - o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving - only when explanation of evolution was necessary. - - o Shortened by removing parameter details from a paragraph in the - Introduction. - - o Moved a reference from Normative to Informative. - - o Added text in intro clarifying there is no handover spec at IEEE, - and that 1609.2 does provide security services. - - o Named the contents the fields of the EthernetII header (including - the Ethertype bitstring). - - o Improved relationship between two paragraphs describing the - increase of the Sequence Number in 802.11 header upon IP - fragmentation. - - o Added brief clarification of "tracking". - - From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- - ipv6-over-80211ocb-01 - - o Introduced message exchange diagram illustrating differences - between 802.11 and 802.11 in OCB mode. - - o Introduced an appendix listing for information the set of 802.11 - messages that may be transmitted in OCB mode. - - o Removed appendix sections "Privacy Requirements", "Authentication - Requirements" and "Security Certificate Generation". - - o Removed appendix section "Non IP Communications". - - o Introductory phrase in the Security Considerations section. - - o Improved the definition of "OCB". - - o Introduced theoretical stacked layers about IPv6 and IEEE layers - including EPD. - - o Removed the appendix describing the details of prohibiting IPv6 on - certain channels relevant to 802.11-OCB. - - o Added a brief reference in the privacy text about a precise clause - in IEEE 1609.3 and .4. - - o Clarified the definition of a Road Side Unit. - - o Removed the discussion about security of WSA (because is non-IP). - - o Removed mentioning of the GeoNetworking discussion. - - o Moved references to scientific articles to a separate 'overview' - draft, and referred to it. - -Appendix B. 802.11p +Appendix A. 802.11p The term "802.11p" is an earlier definition. The behaviour of "802.11p" networks is rolled in the document IEEE Std 802.11-2016. In that document the term 802.11p disappears. Instead, each 802.11p feature is conditioned by the IEEE Management Information Base (MIB) attribute "OCBActivated" [IEEE-802.11-2016]. Whenever OCBActivated is set to true the IEEE Std 802.11-OCB state is activated. For example, an 802.11 STAtion operating outside the context of a basic service set has the OCBActivated flag set. Such a station, when it has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. -Appendix C. Aspects introduced by the OCB mode to 802.11 +Appendix B. Aspects introduced by the OCB mode to 802.11 In the IEEE 802.11-OCB mode, all nodes in the wireless range can directly communicate with each other without involving authentication or association procedures. In OCB mode, the manner in which channels are selected and used is simplified compared to when in BSS mode. Contrary to BSS mode, at link layer, it is necessary to set statically the same channel number (or frequency) on two stations that need to communicate with each other (in BSS mode this channel set operation is performed automatically during 'scanning'). The manner in which stations set their channel number in OCB mode is not @@ -1317,56 +756,57 @@ Briefly, the IEEE 802.11-OCB mode has the following properties: o The use by each node of a 'wildcard' BSSID (i.e., each bit of the BSSID is set to 1) o No IEEE 802.11 Beacon frames are transmitted o No authentication is required in order to be able to communicate o No association is needed in order to be able to communicate + o No encryption is provided in order to be able to communicate o Flag dot11OCBActivated is set to true All the nodes in the radio communication range (IP-OBU and IP-RSU) receive all the messages transmitted (IP-OBU and IP-RSU) within the radio communications range. The eventual conflict(s) are resolved by the MAC CDMA function. - The message exchange diagram in Figure 3 illustrates a comparison + The message exchange diagram in Figure 1 illustrates a comparison between traditional 802.11 and 802.11 in OCB mode. The 'Data' messages can be IP packets such as HTTP or others. Other 802.11 management and control frames (non IP) may be transmitted, as specified in the 802.11 standard. For information, the names of these messages as currently specified by the 802.11 standard are - listed in Appendix G. + listed in Appendix F. STA AP STA1 STA2 | | | | |<------ Beacon -------| |<------ Data -------->| | | | | |---- Probe Req. ----->| |<------ Data -------->| |<--- Probe Res. ------| | | | | |<------ Data -------->| |---- Auth Req. ------>| | | |<--- Auth Res. -------| |<------ Data -------->| | | | | |---- Asso Req. ------>| |<------ Data -------->| |<--- Asso Res. -------| | | | | |<------ Data -------->| |<------ Data -------->| | | |<------ Data -------->| |<------ Data -------->| (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode - Figure 3: Difference between messages exchanged on 802.11 (left) and + Figure 1: Difference between messages exchanged on 802.11 (left) and 802.11-OCB (right) The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, titled "Amendment 6: Wireless Access in Vehicular Environments". Since then, this amendment has been integrated in IEEE 802.11(TM) -2012 and -2016 [IEEE-802.11-2016]. In document 802.11-2016, anything qualified specifically as "OCBActivated", or "outside the context of a basic service" set to be @@ -1472,21 +912,21 @@ 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 documents IEEE 1609.3-2016 [IEEE-1609.3] and IEEE 1609.4-2016 [IEEE-1609.4]. -Appendix D. Changes Needed on a software driver 802.11a to become a +Appendix C. 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: o The PHY entity shall be an orthogonal frequency division multiplexing (OFDM) system. It must support the frequency bands @@ -1537,116 +977,116 @@ Response) and for authentication (Authentication Request/Reply, Challenge) are not called. * The beacon interval is always set to 0 (zero). * Timing Advertisement frames, defined in the amendment, should be supported. The upper layer should be able to trigger such frames emission and to retrieve information contained in received Timing Advertisements. -Appendix E. Protocol Layering +Appendix D. Protocol Layering A more theoretical and detailed view of layer stacking, and interfaces between the IP layer and 802.11-OCB layers, is illustrated - in Figure 4. The IP layer operates on top of the EtherType Protocol + in Figure 2. The IP layer operates on top of the EtherType Protocol Discrimination (EPD); this Discrimination layer is described in IEEE Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP (Link Layer Control Service Access Point). +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 | +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ { LLC_SAP } 802.11-OCB +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary | EPD | | | | | MLME | | +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | | MAC Sublayer | | | 802.11-OCB | and ch. coord. | | SME | Services +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | | | PLME | | | PHY Layer | PLME_SAP | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Figure 4: EtherType Protocol Discrimination + Figure 2: EtherType Protocol Discrimination -Appendix F. Design Considerations +Appendix E. Design Considerations The networks defined by 802.11-OCB are in many ways similar to other networks of the 802.11 family. In theory, the encapsulation of IPv6 over 802.11-OCB could be very similar to the operation of IPv6 over other networks of the 802.11 family. However, the high mobility, strong link asymmetry and very short connection makes the 802.11-OCB link significantly different from other 802.11 networks. Also, the automotive applications have specific requirements for reliability, security and privacy, which further add to the particularity of the 802.11-OCB link. -Appendix G. IEEE 802.11 Messages Transmitted in OCB mode +Appendix F. 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, CF-End, and CF-End plus CFAck; o The STA may send data frames of subtype Data, Null, QoS Data, and QoS Null. -Appendix H. Examples of Packet Formats +Appendix G. Examples of Packet Formats This section describes an example of an IPv6 Packet captured over a IEEE 802.11-OCB link. By way of example we show that there is no modification in the headers when transmitted over 802.11-OCB networks - they are transmitted like any other 802.11 and Ethernet packets. We describe an experiment of capturing an IPv6 packet on an - 802.11-OCB link. In topology depicted in Figure 5, the packet is an + 802.11-OCB link. In topology depicted in Figure 3, the packet is an IPv6 Router Advertisement. This packet is emitted by a Router on its 802.11-OCB interface. The packet is captured on the Host, using a network protocol analyzer (e.g. Wireshark); the capture is performed in two different modes: direct mode and 'monitor' mode. The topology used during the capture is depicted below. The packet is captured on the Host. The Host is an IP-OBU containing an 802.11 interface in format PCI express (an ITRI product). The kernel runs the ath5k software driver with modifications for OCB mode. The capture tool is Wireshark. The file format for save and analyze is 'pcap'. The packet is generated by the Router. The Router is an IP-RSU (ITRI product). +--------+ +-------+ | | 802.11-OCB Link | | ---| Router |--------------------------------| Host | | | | | +--------+ +-------+ - Figure 5: Topology for capturing IP packets on 802.11-OCB + Figure 3: Topology for capturing IP packets on 802.11-OCB During several capture operations running from a few moments to several hours, no message relevant to the BSSID contexts were captured (no Association Request/Response, Authentication Req/Resp, Beacon). This shows that the operation of 802.11-OCB is outside the context of a BSSID. Overall, the captured message is identical with a capture of an IPv6 packet emitted on a 802.11b interface. The contents are precisely similar. -H.1. Capture in Monitor Mode +G.1. Capture in Monitor Mode The IPv6 RA packet captured in monitor mode is illustrated below. The radio tap header provides more flexibility for reporting the characteristics of frames. The Radiotap Header is prepended by this particular stack and operating system on the Host machine to the RA packet received from the network (the Radiotap Header is not present on the air). The implementation-dependent Radiotap Header is useful for piggybacking PHY information from the chip's registers as data in a packet understandable by userland applications using Socket interfaces (the PHY interface can be, for example: power levels, data @@ -1750,21 +1191,21 @@ the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 which is the corresponding multicast MAC address. The BSS id is a broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link duration between vehicles and the roadside infrastructure, there is no need in IEEE 802.11-OCB to wait for the completion of association and authentication procedures before exchanging data. IEEE 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) and may start communicating as soon as they arrive on the communication channel. -H.2. Capture in Normal Mode +G.2. Capture in Normal Mode The same IPv6 Router Advertisement packet described above (monitor mode) is captured on the Host, in the Normal mode, and depicted below. Ethernet II Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...Destination | Source... @@ -1821,30 +1262,30 @@ The value of the Type field in the Ethernet II header is 0x86DD (recognized as "IPv6"); this value is the same value as the value of the field Type in the Logical-Link Control Header in the "monitor" mode capture. The knowledgeable experimenter will no doubt notice the similarity of this Ethernet II Header with a capture in normal mode on a pure Ethernet cable interface. - An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC + A frame translation is inserted on top of a pure IEEE 802.11 MAC layer, in order to adapt packets, before delivering the payload data to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II headers. In further detail, this adaptation consists in the elimination of the Radiotap, 802.11 and LLC headers, and in the insertion of the Ethernet II header. In this way, IPv6 runs straight over LLC over the 802.11-OCB MAC layer; this is further confirmed by the use of the unique Type 0x86DD. -Appendix I. Extra Terminology +Appendix H. Extra Terminology The following terms are defined outside the IETF. They are used to define the main terms in the main terminology section Section 2. DSRC (Dedicated Short Range Communication): a term defined outside the IETF. The US Federal Communications Commission (FCC) Dedicated Short Range Communication (DSRC) is defined in the Code of Federal Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the definitions below. At the time of the writing of this Internet Draft, the last update of this Code was dated October 1st, 2010. @@ -1879,21 +1320,21 @@ carried, but it may only operate when the vehicle or hand- carried unit is stationary. Furthermore, an RSU operating under the respectgive part is restricted to the location where it is licensed to operate. However, portable or hand-held RSUs are permitted to operate where they do not interfere with a site-licensed operation. A RSU broadcasts data to OBUs or exchanges data with OBUs in its communications zone. An RSU also provides channel assignments and operating instructions to OBUs in its communications zone, when required. - [CFR 90.7 - Definitions]. -Appendix J. Neighbor Discovery (ND) Potential Issues in Wireless Links +Appendix I. Neighbor Discovery (ND) Potential Issues in Wireless Links IPv6 Neighbor Discovery (IPv6 ND) [RFC4861][RFC4862] was designed for point-to-point and transit links such as Ethernet, with the expectation of a cheap and reliable support for multicast from the lower layer. Section 3.2 of RFC 4861 indicates that the operation on Shared Media and on non-broadcast multi-access (NBMA) networks require additional support, e.g., for Address Resolution (AR) and duplicate address detection (DAD), which depend on multicast. An infrastructureless radio network such as OCB shares properties with both Shared Media and NBMA networks, and then adds its own