idnits 2.17.1 draft-ietf-manet-nhdp-olsrv2-tlv-extension-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- == The 'Updates: ' line in the draft header should list only the _numbers_ of the RFCs which will be updated by this document (if approved); it should not include the word 'RFC' in the list. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 23, 2014) is 3739 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Mobile Ad hoc Networking (MANET) C. Dearlove 3 Internet-Draft BAE Systems ATC 4 Updates: RFC6130, OLSRv2 T. Clausen 5 (if approved) LIX, Ecole Polytechnique 6 Intended status: Standards Track January 23, 2014 7 Expires: July 27, 2014 9 Optimized Link State Routing Protocol version 2 (OLSRv2) and MANET 10 Neighborhood Discovery Protocol (NHDP) Extension TLVs 11 draft-ietf-manet-nhdp-olsrv2-tlv-extension-01 13 Abstract 15 This specification describes extensions to definitions of TLVs used 16 by the Optimized Link State Routing Protocol version 2 (OLSRv2) and 17 the MANET Neighborhood Discovery Protocol (NHDP), to increase their 18 abilities to accommodate protocol extensions. This document updates 19 OLSRv2 and RFC6130. 21 Status of this Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at http://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on July 27, 2014. 38 Copyright Notice 40 Copyright (c) 2014 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (http://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 56 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 3. Applicability Statement . . . . . . . . . . . . . . . . . . . 3 58 4. TLV Values . . . . . . . . . . . . . . . . . . . . . . . . . . 4 59 4.1. Unrecognized TLV Values . . . . . . . . . . . . . . . . . 4 60 4.2. TLV Value Lengths . . . . . . . . . . . . . . . . . . . . 5 61 4.3. Undefined TLV Values . . . . . . . . . . . . . . . . . . . 5 62 4.3.1. NHDP TLVs: LOCAL_IF, LINK_STATUS and OTHER_NEIGHB . . 6 63 4.3.2. OLSRv2 TLVs: MPR and NBR_ADDR_TYPE . . . . . . . . . . 6 64 4.3.3. Unspecified TLV Values . . . . . . . . . . . . . . . . 6 65 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 66 5.1. Address Block TLVs . . . . . . . . . . . . . . . . . . . . 7 67 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 68 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 69 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 70 8.1. Normative References . . . . . . . . . . . . . . . . . . . 11 71 8.2. Informative References . . . . . . . . . . . . . . . . . . 11 72 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 74 1. Introduction 76 The MANET Neighborhood Discovery Protocol (NHDP) [RFC6130] and the 77 Optimized Link State Routing Protocol, version 2 (OLSRv2) [OLSRv2] 78 are protocols for use in mobile ad hoc networks (MANETs) [RFC2501], 79 based on the Generalized Mobile Ad Hoc Network (MANET) Packet/Message 80 Format [RFC5444]. 82 This document updates [RFC6130] and [OLSRv2], specifically their use 83 of TLV (Type-Length-Value) elements, to increase the extensibility of 84 these protocols, and to enable some improvements in their 85 implementation. 87 This specification reduces the latitude of implementations of 88 [OLSRv2] and [RFC6130] to consider some messages, which will not be 89 created by implementations simply following those specifications, as 90 a reason to consider the message as "badly formed", and thus as a 91 reason to reject the message. This gives greater latitude to the 92 creation of extensions of these protocols, in particular extensions 93 that will interoperate with unextended implementations of those 94 protocols. As part of that, it indicates how TLVs (Type-Length-Value 95 elements) [RFC5444] with unexpected value fields must be handled, and 96 adds some additional options to those TLVs. 98 2. Terminology 100 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 101 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 102 "OPTIONAL" in this document are to be interpreted as described in 103 [RFC2119]. 105 Additionally, this document uses the terminology of [RFC5444], 106 [RFC6130], and [OLSRv2]. 108 3. Applicability Statement 110 This document updates the specification of the protocols [OLSRv2] and 111 [RFC6130]. As such it is applicable to all implementations of these 112 protocols. 114 Specifically, this specification updates [RFC6130] and [OLSRv2] in 115 the following way: 117 o Removes the latitude of rejecting a message with a TLV with a 118 known type, but with an unexpected TLV Value field, for the TLV 119 Types defined in [RFC6130] and [OLSRv2]. 121 o Specifies the handling of a TLV Value field with unexpected 122 length. 124 o Sets up IANA registries for TLV Values for the Address Block TLVs: 126 * LOCAL_IF, defined in [RFC6130]. 128 * LINK_STATUS, defined in [RFC6130]. 130 * OTHER_NEIGHB, defined in [RFC6130]. 132 * MPR, defined in [OLSRv2], now considered as a bit field. 134 * NBR_ADDR_TYPE, defined in [OLSRv2], now considered as a bit 135 field. 137 o Defines a well-known TLV Value for "UNSPECIFIED" for the Address 138 Block TLV Types LOCAL_IF, LINK_STATUS, and OTHER_NEIGHB, all 139 defined in [RFC6130]. 141 4. TLV Values 143 NHDP [RFC6130] and OLSRv2 [OLSRv2] define a number of TLVs within the 144 framework of [RFC5444]. These TLVs define the meaning of only some 145 of the contents that can be found in a TLV Value field. This 146 limitation may be either only defining certain TLV Values, or 147 considering only some lengths of the TLV Value fields (or single 148 value field in a multi value Address-Block TLV). This specification 149 describes how NHDP [RFC6130] and OLSRv2 [OLSRv2] SHOULD handle TLVs 150 with other TLV Value fields. 152 4.1. Unrecognized TLV Values 154 NHDP and OLSRv2 specify that, in addition to well-defined reasons (in 155 the respective protocol specifications), an implementation of these 156 protocols MAY recognize a message as "badly formed" and therefore 157 "invalid for processing" for other reasons (Section 12.1 of [RFC6130] 158 and Section 16.3.1 of [OLSRv2]). These sections could be interpreted 159 as allowing rejection of a message because a TLV Value field is 160 unrecognized. This specification removes that latitude: 162 o An implementation MUST NOT reject a message because it contains 163 such a TLV. Instead, any unrecognised TLV Value field MUST be 164 processed or ignored by an unextended implementation of NHDP or 165 OLSRv2, as described in the following sections. 167 It should be stressed that this is not a change to [RFC6130] or 169 [OLSRv2], except with regard to not allowing this to be a reason for 170 rejection of a message. [RFC6130] or [OLSRv2] are specified in terms 171 such as "if an address is associated with a value of LOST by a 172 LINK_STATUS TLV". Association with an unrecognized value has no 173 effect on any implementation strictly following such a specification. 175 4.2. TLV Value Lengths 177 The TLVs specified in [RFC6130] and [OLSRv2] may be either single- 178 value or multi-value TLVs. In either case, the length of each item 179 of information encoded in the TLV Value field is the "single-length", 180 defined and calculated as in section 5.4.1 in [RFC5444]. All TLVs 181 specified in [RFC6130] and [OLSRv2] have a one or two octet single- 182 length. These are considered the expected single-lengths of such a 183 received TLV. 185 Other single-length TLV Value fields may be introduced by extensions 186 to [RFC6130] and [OLSRv2]. This document specifies how 187 implementations of [RFC6130] and [OLSRv2], or extensions thereof, 188 MUST behave on receiving TLVs of the TLV types defined in [RFC6130] 189 and [OLSRv2], but with TLV Value fields with other single-length 190 values. 192 The following principles apply: 194 o If the received single-length is greater than the expected single- 195 length, then the excess octets MUST be ignored. 197 o If the received single-length is less than the expected single- 198 length, then the absent octets MUST considered to have all bits 199 cleared (0). 201 Exceptions: 203 o A received CONT_SEQ_NUM with a single-length < 2 SHOULD be 204 considered an error. 206 4.3. Undefined TLV Values 208 [RFC6130] and [OLSRv2] define a number of TLVs, but for some of these 209 TLVs specify meanings for only some TLV Values. This document 210 establishes IANA registries for these TLV Values, with initial 211 registrations reflecting those used by [RFC6130] and [OLSRv2], and as 212 specified in Section 4.3.3. 214 There are different cases of TLV Values with different 215 characteristics. These cases are considered in this section. 217 4.3.1. NHDP TLVs: LOCAL_IF, LINK_STATUS and OTHER_NEIGHB 219 For the Address-Block TLVs LOCAL_IF, LINK_STAUS and OTHER_NEIGHB 220 TLVs, defined in [RFC6130], only a limited number of values are 221 specified for each. These are converted, by this specification, into 222 extensible registries with initial registrations for values defined 223 and used by [RFC6130] - see Section 5. 225 An implementation of [RFC6130], receiving a TLV with any TLV Value 226 other than those values used in that specification, MUST ignore that 227 TLV Value and any corresponding attribute association to the address. 229 4.3.2. OLSRv2 TLVs: MPR and NBR_ADDR_TYPE 231 The Address-Block TLVs MPR and NBR_ADDR_TYPE, defined in [OLSRv2], 232 are similar to those defined in [RFC6130] in having only limited 233 values specified (1, 2 and 3): 1 and 2, represent presence of two 234 different attributes associated to an address, and 3 represents "both 235 1 and 2". 237 These TLV Value fields, are by this specification, converted to bit 238 fields, and MUST be interpreted as such. As the existing definitions 239 of values 1, 2, and 3 behave in that manner, it is likely that this 240 will involve no change to an implementation, but any test of (for 241 example) Value = 1 or Value = 3 MUST be converted to a test of (for 242 example) Value bitand 1 = 1, where "bitand" denotes a bitwise and 243 operation. 245 This specification creates registries for recording reservations of 246 the individual bits in these bitfields, with initial registrations 247 for values defined and used by [OLSRv2] - see Section 5. 249 Other TLVs defined by [OLSRv2] are not affected by this 250 specification. 252 4.3.3. Unspecified TLV Values 254 The registries defined in Section 5 for the LOCAL_IF, LINK_STATUS and 255 OTHER_NEIGHB TLVs each include an additional TLV Value UNSPECIFIED. 256 This TLV Value represents a defined value that, like currently 257 undefined TLV Values, indicates that no information is associated 258 with this address, but will always have this meaning. Such a TLV 259 Value may be used to enable the creation of more efficient multivalue 260 Address Block TLVs, or to simplify an implementation. 262 The similar requirement for the MPR and NBR_ADDR_TYPES TLVs is 263 already satisfied by the TLV Value zero, provided that each bit in 264 the TLV Value is defined as set ('1') when indicating the presence of 265 an attribute, or clear ('0') when indicating the absence of an 266 attribute; this is therefore required for registrations from the 267 relevant registries, see Section 5. 269 For the LINK_METRIC TLV, this is already possible by clearing the 270 most significant bits (0 to 3) of the first octet of the TLV Value. 271 It is RECOMMENDED that in this case the remaining bits of the TLV 272 Value are either all clear ('0') or all set ('1'). 274 5. IANA Considerations 276 Note: Values defined as "Unallocated: Expert Review" mean that these 277 values may be allocated according to the expert review guidelines 278 specified in [RFC6130] and [OLSRv2]. In two cases a constraint on 279 future allocation is specified. IANA tables referenced are from 280 "Mobile Ad hoc NETwork (MANET) Parameters". 282 5.1. Address Block TLVs 284 IANA is requested to create a registry associated with the Address 285 Block TLV with name LOCAL_IF (Type = 2, Type Extension = 0) defined 286 in [RFC6130], specifying the meaning of its single values. This 287 replaces the Description column in IANA table "LOCAL_IF Address Block 288 TLV Type Extensions" (from Table 6 in [RFC6130]) by a reference to 289 this table. 291 +---------+-------------+-------------------------------------------+ 292 | Value | Name | Description | 293 +---------+-------------+-------------------------------------------+ 294 | 0 | THIS_IF | The network address is associated with | 295 | | | this local interface of the sending | 296 | | | router | 297 | 1 | OTHER_IF | The network address is associated with | 298 | | | another local interface of the sending | 299 | | | router | 300 | 2-223 | | Unallocated: Expert Review | 301 | 224-254 | | Experimental Use | 302 | 255 | UNSPECIFIED | No information about this network address | 303 | | | is provided | 304 +---------+-------------+-------------------------------------------+ 306 Table 1: LOCAL_IF TLV Values 308 IANA are requested to create a registry associated with the Address 309 Block TLV with name LINK_STATUS (Type = 3, Type Extension = 0) 310 defined in [RFC6130], specifying the meaning of its single values. 311 This replaces the Description column in the IANA table "LINK_STATUS 312 Address Block TLV Type Extensions" (from Table 7 in [RFC6130]) by a 313 reference to this table. 315 +---------+-------------+-------------------------------------------+ 316 | Value | Name | Description | 317 +---------+-------------+-------------------------------------------+ 318 | 0 | LOST | The link on this interface from the | 319 | | | router with that network address has been | 320 | | | lost | 321 | 1 | SYMMETRIC | The link on this interface from the | 322 | | | router with that network address has the | 323 | | | status of symmetric | 324 | 2 | HEARD | The link on this interface from the | 325 | | | router with that network address has the | 326 | | | status of heard | 327 | 3-223 | | Unallocated: Expert Review | 328 | 224-254 | | Experimental Use | 329 | 255 | UNSPECIFIED | No information about this network address | 330 | | | is provided | 331 +---------+-------------+-------------------------------------------+ 333 Table 2: LINK_STATUS TLV Values 335 IANA are requested to create a registry associated with the Address 336 Block TLV with name OTHER_NEIGHB (Type = 4, Type Extension = 0) 337 defined in [RFC6130], specifying the meaning of its single values. 338 This replaces the Description column in Table 8 in the IANA table 339 "OTHER_NEIGHB Address Block TLV Type Extensions" (from [RFC6130]) by 340 a reference to this table. 342 +---------+-------------+-------------------------------------------+ 343 | Value | Name | Description | 344 +---------+-------------+-------------------------------------------+ 345 | 0 | LOST | The neighbor relationship with the router | 346 | | | with that network address has been lost | 347 | 1 | SYMMETRIC | The neighbor relationship with the router | 348 | | | with that network address is symmetric | 349 | 2-223 | | Unallocated: Expert Review | 350 | 224-254 | | Experimental Use | 351 | 255 | UNSPECIFIED | No information about this network address | 352 | | | is provided | 353 +---------+-------------+-------------------------------------------+ 355 Table 3: OTHER_NEIGHB TLV Values 357 IANA are requested to create a registry associated with the Address 358 Block TLV with name MPR (Type = 8, Type Extension = 0) defined in 359 [OLSRv2], specifying the meaning of its single values in terms of the 360 values of each bit of the value, from bit 0 (most significant) to bit 361 7 (least significant). If multiple bits are set then each applies. 362 This replaces the Description column in the (not yet created) IANA 363 table "MPR Address Block TLV Type Extensions" (from Table 14 in 364 [OLSRv2]) by a reference to this table. 366 +-------+-------+----------+----------------------------------------+ 367 | Value | Value | Name | Description | 368 | Bit | | | | 369 +-------+-------+----------+----------------------------------------+ 370 | 7 | 1 | FLOODING | The neighbor with that network address | 371 | | | | has been selected as flooding MPR | 372 | 6 | 2 | ROUTING | The neighbor with that network address | 373 | | | | has been selected as flooding MPR | 374 | 0-5 | | | Unallocated: Expert Review | 375 +-------+-------+----------+----------------------------------------+ 377 Table 4: MPR TLV Bit Values 379 Note that this registry maintains a bit field, and that the 380 combination of the bits FLOODING + ROUTING being set (1) (which gives 381 a value of 3) is given the name FLOOD_ROUTE in [OLSRv2]. For all 382 future allocations, the Expert Review MUST ensure that allocated bits 383 MUST use the unset bit (0) to indicates no information, so that the 384 case Value = 0 will always indicate that no information about this 385 network address is provided. 387 IANA are requested to create a registry associated with the Address 388 Block TLV with name NBR_ADDR_TYPE (Type = 9, Type Extension = 0) 389 defined in [OLSRv2], specifying the meaning of its single values in 390 terms of the values of each bit of the value, from bit 0 (most 391 significant) to bit 7 (least significant). If multiple bits are set 392 then each applies. This replaces the Description column in the (not 393 yet created) IANA table "NBR_ADDR_TYPE Address Block TLV Type 394 Extensions" (from Table 15 in [OLSRv2]) by a reference to this table. 396 +-------+-------+------------+--------------------------------------+ 397 | Value | Value | Name | Description | 398 | Bit | | | | 399 +-------+-------+------------+--------------------------------------+ 400 | 7 | 1 | ORIGINATOR | The network address is an originator | 401 | | | | address reachable via the | 402 | | | | originating router | 403 | 6 | 2 | ROUTABLE | The network address is a routable | 404 | | | | address reachable via the | 405 | | | | originating router | 406 | 0-5 | | | Unallocated: Expert Review | 407 +-------+-------+------------+--------------------------------------+ 408 Table 5: NBR_ADDR_TYPE TLV Bit Values 410 Note that this registry maintains a bit field, and that the 411 combination of the bits ORIGINATOR + ROUTABLE being set (1) (which 412 gives a value of 3) is given the name ROUTABLE_ORIG in [OLSRv2]. For 413 all future allocations, the Expert Review MUST ensure that allocated 414 bits MUST use the unset bit (0) to indicates no information, so that 415 the case Value = 0 will always indicate that no information about 416 this network address is provided. 418 6. Security Considerations 420 The presented updates to [RFC6130] and [OLSRv2]: 422 o Create IANA registries for retaining TLV values for TLVs, already 423 defined in the already published specifications of the two 424 protocols, and with initial registrations for the TLV values 425 defined by these specifications. This does not give rise to any 426 additional security considerations. 428 o Enable protocol extensions to be able to register TLV values in 429 the created IANA registries. Such extensions MUST specify 430 appropriate security considerations. 432 o Create, in some registries, a registration for "UNSPECIFIED" 433 values, for more efficient use of multi-value Address Block TLVs. 434 The interpretation of an address being associated with a TLV of a 435 given type and with the value "UNSPECIFIED" is identical to that 436 address not being associated with a TLV of that type. Thus, this 437 update does not give rise to any additional security 438 considerations. 440 o Reduces the latitude of implementations of the two protocols to 441 reject a message as "badly formed", due to the value field of a 442 TLV being unexpected. These protocols are specified in terms such 443 as "if an address is associated with a value of LOST by a 444 LINK_STATUS TLV". Association with an unknown value (or a value 445 newly defined to mean no link status information) has no effect on 446 such a specification. Thus, this update does not give rise to any 447 additional security considerations. 449 o Do not introduce any opportunities for attacks on the protocols 450 through signal modification that are not already present in the 451 two protocols. 453 7. Acknowledgments 455 The authors would like to gratefully acknowledge the following people 456 for intense technical discussions, early reviews, and comments on the 457 specification (listed alphabetically): Ulrich Herberg (Fujitsu 458 Laboratories of America) and Henning Rogge (Frauenhofer FKIE). 460 8. References 462 8.1. Normative References 464 [OLSRv2] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg, 465 "The Optimized Link State Routing Protocol version 2", 466 work in progress draft-ietf-manet-olsrv2-19, March 2013. 468 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 469 Requirement Levels", BCP 14, RFC 2119, March 1997. 471 [RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih, 472 "Generalized MANET Packet/Message Format", RFC 5444, 473 February 2009. 475 [RFC6130] Clausen, T., Dean, J., and C. Dearlove, "Mobile Ad Hoc 476 Network (MANET) Neighborhood Discovery Protocol (NHDP)", 477 RFC 6130, April 2011. 479 8.2. Informative References 481 [RFC2501] Macker, J. and S. Corson, "Mobile Ad hoc Networking 482 (MANET): Routing Protocol Performance Issues and 483 Evaluation Considerations", RFC 2501, January 1999. 485 Authors' Addresses 487 Christopher Dearlove 488 BAE Systems Advanced Technology Centre 489 West Hanningfield Road 490 Great Baddow, Chelmsford 491 United Kingdom 493 Phone: +44 1245 242194 494 Email: chris.dearlove@baesystems.com 495 URI: http://www.baesystems.com/ 496 Thomas Heide Clausen 497 LIX, Ecole Polytechnique 499 Phone: +33 6 6058 9349 500 Email: T.Clausen@computer.org 501 URI: http://www.ThomasClausen.org/