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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (July 31, 2013) is 3920 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 July 31, 2013 7 Expires: February 1, 2014 9 Optimized Link State Routing Protocol version 2 (OLSRv2) and MANET 10 Neighborhood Discovery Protocol (NHDP) Extension TLVs 11 draft-dearlove-manet-nhdp-olsrv2-tlv-extension-02 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 February 1, 2014. 38 Copyright Notice 40 Copyright (c) 2013 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 . . . . . . . . . . . . . . . . . . . . . . . 10 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 unrecognied TLV Value field MUST be 164 processed or ignored by an unextended implementation of NHDP or 165 OLSRv2, as discussed 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 the 179 information encoded in the TLV Value field is the "single-length", 180 defined and calculated as per section 5.4.1 in [RFC5444]. All TLVs 181 specified in [RFC6130] and [OLSRv2] describe TLVs with one or two 182 octet TLV Value field single-lengths. These are considered the 183 expected values of single-length for a 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. 191 The following principles apply: 193 o If the received single-length is greater than the expected single- 194 length, then the excess octets MUST be ignored. 196 o If the received single-length is less than the expected single- 197 length, then the absent octets MUST considered to have all bits 198 cleared (0). 200 Exceptions: 202 o A received CONT_SEQ_NUM with a signle-lentgh < 2 SHOULD be 203 considered an error. 205 4.3. Undefined TLV Values 207 [RFC6130] and [OLSRv2] define a number of TLVs, but for some of these 208 TLVs specify meanings for only some TLV Values. This document 209 establishes IANA registries for these TLV Values, with initial 210 registrations reflecting those used by [RFC6130] and [OLSRv2], and as 211 specified in Section 4.3.3. 213 There are different cases of TLV Values with different 214 characteristics. These cases are considerd in this section. 216 4.3.1. NHDP TLVs: LOCAL_IF, LINK_STATUS and OTHER_NEIGHB 218 For the Address-Block TLVs LOCAL_IF, LINK_STAUS and OTHER_NEIGHB 219 TLVs, defined in [RFC6130], only a limited number of values are 220 specified for each. These are converted, by this specification, into 221 extensible registries with initial registrations for values defined 222 and used by [RFC6130] - see Section 5. 224 An implementation of [RFC6130], receiving a TLV with any TLV Value 225 other than those values used in that specification, MUST ignore that 226 TLV Value and any corresponding attribute association to the address. 228 4.3.2. OLSRv2 TLVs: MPR and NBR_ADDR_TYPE 230 The Address-Block TLVs MPR and NBR_ADDR_TYPE, defined in [OLSRv2], 231 are similar to those defined in [RFC6130] in having only limited 232 values specified (1, 2 and 3): 1 and 2, represent presence of two 233 different attributes associated to an address, and 3 represents "both 234 1 and 2". 236 These TLV Value fields, are by this specification, converted to bit 237 fields, and MUST be interpreted as such. As the existing definitions 238 of values 1, 2, and 3 behave in that manner, it is likely that this 239 will involve no change to an implementation, but any test of (for 240 example) Value = 1 or Value = 3 MUST be converted to a test of (for 241 example) Value bitand 1 = 1, where "bitand" denotes a bitwise and 242 operation. 244 This specification creates registries for recording reservations of 245 the individual bits in these bitfields, with initial registrations 246 for values defined and used by [OLSRv2] - see Section 5. 248 Other TLVs, defined by [OLSRv2], are not affected by this 249 specification. 251 4.3.3. Unspecified TLV Values 253 The registries defined in Section 5 for the LOCAL_IF, LINK_STATUS and 254 OTHER_NEIGHB TLVs each include an additional TLV Value UNSPECIFIED. 255 This TLV Value represents a value that MUST NOT be defined in any 256 extension of [RFC6130]. Such a TLV Value MAY be used to enable the 257 creation of more efficient multivalue Address Block TLVs, or to 258 simplify an implementation. 260 The similar requirement for the MPR and NBR_ADDR_TYPES TLVs is 261 already satisfied by the TLV Value zero, provided that each bit in 262 the TLV Value is defined as set ('1') when indicating the presence of 263 an attribute, or clear ('0') when indicating the absence of an 264 attribute; this is therefore REQUIRED for registrations from the 265 relevant registries, see Section 5. 267 For the LINK_METRIC TLV, this is already possible by clearing the 268 most significant bits (0 to 3) of the first octet of the TLV Value. 269 It is RECOMMENDED that in this case the remaining bits of the TLV 270 Value are either all clear ('0') or all set ('1'). 272 5. IANA Considerations 274 Note: Values defined as "Unallocated: Expert Review" mean that these 275 values may be allocated according to the expert review guidelines 276 specified in [RFC6130] and [OLSRv2]. In two cases a constraint on 277 future allocation is specified. 279 5.1. Address Block TLVs 281 IANA is requested to create a registry associated with the Address 282 Block TLV with name LOCAL_IF (Type = 2, Type Extension = 0) defined 283 in [RFC6130], specifying the meaning of its single values. This 284 replaces the Description column in Table 6 in [RFC6130] by a 285 reference to this table. 287 +---------+-------------+-------------------------------------------+ 288 | Value | Name | Description | 289 +---------+-------------+-------------------------------------------+ 290 | 0 | THIS_IF | The network address is associated with | 291 | | | this local interface of the sending | 292 | | | router | 293 | 1 | OTHER_IF | The network address is associated with | 294 | | | another local interface of the sending | 295 | | | router | 296 | 2-223 | | Unallocated: Expert Review | 297 | 224-254 | | Experimental Use | 298 | 255 | UNSPECIFIED | No information about this network address | 299 | | | is provided | 300 +---------+-------------+-------------------------------------------+ 302 Table 1: LOCAL_IF TLV Values 304 IANA are requested to create a registry associated with the Address 305 Block TLV with name LINK_STATUS (Type = 3, Type Extension = 0) 306 defined in [RFC6130], specifying the meaning of its single values. 307 This replaces the Description column in Table 7 in [RFC6130] by a 308 reference to this table. 310 +---------+-------------+-------------------------------------------+ 311 | Value | Name | Description | 312 +---------+-------------+-------------------------------------------+ 313 | 0 | LOST | The link on this interface from the | 314 | | | router with that network address has been | 315 | | | lost | 316 | 1 | SYMMETRIC | The link on this interface from the | 317 | | | router with that network address has the | 318 | | | status of symmetric | 319 | 2 | HEARD | The link on this interface from the | 320 | | | router with that network address has the | 321 | | | status of heard | 322 | 3-223 | | Unallocated: Expert Review | 323 | 224-254 | | Experimental Use | 324 | 255 | UNSPECIFIED | No information about this network address | 325 | | | is provided | 326 +---------+-------------+-------------------------------------------+ 328 Table 2: LINK_STATUS TLV Values 330 IANA are requested to create a registry associated with the Address 331 Block TLV with name OTHER_NEIGHB (Type = 4, Type Extension = 0) 332 defined in [RFC6130], specifying the meaning of its single values. 333 This replaces the Description column in Table 8 in [RFC6130] by a 334 reference to this table. 336 +---------+-------------+-------------------------------------------+ 337 | Value | Name | Description | 338 +---------+-------------+-------------------------------------------+ 339 | 0 | LOST | The neighbor relationship with the router | 340 | | | with that network address has been lost | 341 | 1 | SYMMETRIC | The neighbor relationship with the router | 342 | | | with that network address is symmetric | 343 | 2-223 | | Unallocated: Expert Review | 344 | 224-254 | | Experimental Use | 345 | 255 | UNSPECIFIED | No information about this network address | 346 | | | is provided | 347 +---------+-------------+-------------------------------------------+ 349 Table 3: OTHER_NEIGHB TLV Values 351 IANA are requested to create a registry associated with the Address 352 Block TLV with name MPR (Type = 8, Type Extension = 0) defined in 353 [OLSRv2], specifying the meaning of its single values in terms of the 354 values of each bit of the value, from bit 0 (most significant) to bit 355 7 (least significant). If multiple bits are set then each applies. 356 This replaces the Description column in Table 14 in [OLSRv2] by a 357 reference to this table. 359 +-------+-------+----------+----------------------------------------+ 360 | Value | Value | Name | Description | 361 | Bit | | | | 362 +-------+-------+----------+----------------------------------------+ 363 | 7 | 1 | FLOODING | The neighbor with that network address | 364 | | | | has been selected as flooding MPR | 365 | 6 | 2 | ROUTING | The neighbor with that network address | 366 | | | | has been selected as flooding MPR | 367 | 0-5 | | | Unallocated: Expert Review | 368 +-------+-------+----------+----------------------------------------+ 370 Table 4: MPR TLV Bit Values 372 Note that this registry maintains a bit field, and that the 373 combination of the bits FLOODING + ROUTING being set (1) (which gives 374 a value of 3) is given the name FLOOD_ROUTE in [OLSRv2]. For all 375 future allocations, the Expert Review MUST ensure that allocated bits 376 MUST use the unset bit (0) to indicates no information, so that the 377 case Value = 0 will always indicate that no information about this 378 network address is provided. 380 IANA are requested to create a registry associated with the Address 381 Block TLV with name NBR_ADDR_TYPE (Type = 9, Type Extension = 0) 382 defined in [OLSRv2], specifying the meaning of its single values in 383 terms of the values of each bit of the value, from bit 0 (most 384 significant) to bit 7 (least significant). If multiple bits are set 385 then each applies. This replaces the Description column in Table 15 386 in [OLSRv2] by a reference to this table. 388 +-------+-------+------------+--------------------------------------+ 389 | Value | Value | Name | Description | 390 | Bit | | | | 391 +-------+-------+------------+--------------------------------------+ 392 | 7 | 1 | ORIGINATOR | The network address is an originator | 393 | | | | address reachable via the | 394 | | | | originating router | 395 | 6 | 2 | ROUTABLE | The network address is a routable | 396 | | | | address reachable via the | 397 | | | | originating router | 398 | 0-5 | | | Unallocated: Expert Review | 399 +-------+-------+------------+--------------------------------------+ 401 Table 5: NBR_ADDR_TYPE TLV Bit Values 403 Note that this registry maintains a bit field, and that the 404 combination of the bits ORIGINATOR + ROUTABLE being set (1) (which 405 gives a value of 3) is given the name ROUTABLE_ORIG in [OLSRv2]. For 406 all future allocations, the Expert Review MUST ensure that allocated 407 bits MUST use the unset bit (0) to indicates no information, so that 408 the case Value = 0 will always indicate that no information about 409 this network address is provided. 411 6. Security Considerations 413 The presented updates to [RFC6130] and [OLSRv2]: 415 o Create IANA registries for retaining TLV values for TLVs, already 416 defined in the already published specifications of the two 417 protocols, and with initial registrations for the TLV values 418 defined by these specifications. This does not give rise to any 419 additional security considerations. 421 o Enable protocol extensions to be able to register TLV values in 422 the created IANA registries. Such extensions MUST specify 423 appropriate security considerations. 425 o Create, in some registries, a registration for "UNSPECIFIED" 426 values, for more efficient use of multi-value Address Block TLVs. 427 The interpretation of an address being associated with a TLV of a 428 given type and with the value "UNSPECIFIED" is identical to that 429 address not being associated with a TLV of that type. Thus, this 430 update does not give rise to any additional security 431 considerations. 433 o Reduces the latitude of implementations of the two protocols to 434 reject a message as "badly formed", due to the value field of a 435 TLV being unexpected. These protocols are specified in terms such 436 as "if an address is associated with a value of LOST by a 437 LINK_STATUS TLV". Association with an unknown value (or a value 438 newly defined to mean no link status information) has no effect on 439 such a specification. Thus, this update does not give rise to any 440 additional security considerations. 442 o Do not introduce any opportunities for attacks on the protocols 443 through signal modification, not already present in the two 444 protocols. 446 7. Acknowledgments 448 The authors would like to gratefully acknowledge the following people 449 for intense technical discussions, early reviews, and comments on the 450 specification (listed alphabetically): Ulrich Herberg (Fujitsu 451 Laboratories of America) and Henning Rogge (Frauenhofer FKIE). 453 8. References 455 8.1. Normative References 457 [OLSRv2] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg, 458 "The Optimized Link State Routing Protocol version 2", 459 work in progress draft-ietf-manet-olsrv2-19, March 2013. 461 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 462 Requirement Levels", BCP 14, RFC 2119, March 1997. 464 [RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih, 465 "Generalized MANET Packet/Message Format", RFC 5444, 466 February 2009. 468 [RFC6130] Clausen, T., Dean, J., and C. Dearlove, "Mobile Ad Hoc 469 Network (MANET) Neighborhood Discovery Protocol (NHDP)", 470 RFC 6130, April 2011. 472 8.2. Informative References 474 [RFC2501] Macker, J. and S. Corson, "Mobile Ad hoc Networking 475 (MANET): Routing Protocol Performance Issues and 476 Evaluation Considerations", RFC 2501, January 1999. 478 Authors' Addresses 480 Christopher Dearlove 481 BAE Systems Advanced Technology Centre 482 West Hanningfield Road 483 Great Baddow, Chelmsford 484 United Kingdom 486 Phone: +44 1245 242194 487 Email: chris.dearlove@baesystems.com 488 URI: http://www.baesystems.com/ 490 Thomas Heide Clausen 491 LIX, Ecole Polytechnique 493 Phone: +33 6 6058 9349 494 Email: T.Clausen@computer.org 495 URI: http://www.ThomasClausen.org/