Internet DRAFT - draft-cms-masque-connect-ip-ext-routes
draft-cms-masque-connect-ip-ext-routes
MASQUE A. Chernyakhovsky
Internet-Draft D. McCall
Intended status: Standards Track D. Schinazi
Expires: 28 February 2022 Google LLC
27 August 2021
A Routing Extension to CONNECT-IP
draft-cms-masque-connect-ip-ext-routes-00
Abstract
This document describes an extension to the CONNECT-IP HTTP method.
This extension allows both endpoints to negotiate routes. This
enables split-tunnel VPN services, and network-to-network VPNs.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Multiplexed
Application Substrate over QUIC Encryption Working Group mailing list
(masque@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/masque/.
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 28 February 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
Chernyakhovsky, et al. Expires 28 February 2022 [Page 1]
Internet-Draft CONNECT-IP Routes August 2021
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 carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions and Definitions . . . . . . . . . . . . . . . 3
2. Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Capsules . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. ROUTE_ADVERTISEMENT Capsule . . . . . . . . . . . . . . . 3
3.2. ROUTE_REJECTION Capsule . . . . . . . . . . . . . . . . . 4
3.3. ROUTE_RESET Capsule . . . . . . . . . . . . . . . . . . . 5
3.4. ATOMIC_START Capsule . . . . . . . . . . . . . . . . . . 5
3.5. ATOMIC_END Capsule . . . . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
5.1. Capsule Type Registrations . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 8
A.1. Consumer VPN . . . . . . . . . . . . . . . . . . . . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
This document describes an extension to the CONNECT-IP HTTP method
[CONNECT-IP]. This extension allows both endpoints to negotiate
routes. This enables split-tunnel VPN services, and network-to-
network VPNs.
CONNECT-IP allows endpoints to set up an IP tunnel between one
another but does not allow exchanging which routes are supported
though the tunnel. This extension can be used to connect an endpoint
or network to another network without changing default routes.
Chernyakhovsky, et al. Expires 28 February 2022 [Page 2]
Internet-Draft CONNECT-IP Routes August 2021
1.1. Conventions and Definitions
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.
In this document, we use the term "proxy" to refer to the HTTP server
that responds to the CONNECT-IP request. If there are HTTP
intermediaries (as defined in Section 2.3 of [RFC7230]) between the
client and the proxy, those are referred to as "intermediaries" in
this document.
2. Routes
Endpoints have the ability to advertise and reject routes using the
ROUTE_ADVERTISEMENT (Section 3.1) and ROUTE_REJECTION (Section 3.1)
capsule. Note that these capsules are purely informational: receipt
of a ROUTE_ADVERTISEMENT capsule does not require the recipient to
start routing traffic to its peer. Additionally, if an endpoint
receives a ROUTE_REJECTION for a given prefix that it had previously
received a ROUTE_ADVERTISEMENT capsule for, then the two cancel out
and the endpoint MUST remove its state from the ROUTE_ADVERTISEMENT
capsule instead of installing new state for the ROUTE_REJECTION
capsule. Conversely, the same is true of a ROUTE_ADVERTISEMENT that
matches a previous ROUTE_REJECTION. Routes are handled via longest-
prefix-first preference, meaning that if a given IP prefix is covered
by multiple route advertisement and route rejections, the one with
the longest prefix is used.
When processing ROUTE_ADVERTISEMENT capsules, endpoints MUST check
their local policy before deciding whether to forward packets to
their peer. Since ignoring these capsules is allowed by the
protocol, such policy decisions will not prevent interoperability.
3. Capsules
3.1. ROUTE_ADVERTISEMENT Capsule
The ROUTE_ADVERTISEMENT capsule allows an endpoint to communicate to
its peer that it is willing to route traffic to a given prefix. This
indicates that the sender has an existing route to the prefix, and
notifies its peer that if the receiver of the ROUTE_ADVERTISEMENT
capsule sends IP packets for this prefix in HTTP Datagrams, the
sender of the capsule will forward them along its preexisting route.
This capsule uses a Capsule Type of 0xfff102. Its value uses the
following format:
Chernyakhovsky, et al. Expires 28 February 2022 [Page 3]
Internet-Draft CONNECT-IP Routes August 2021
ROUTE_ADVERTISEMENT Capsule {
IP Version (8),
IP Address (32..128),
IP Prefix Length (8),
}
Figure 1: ROUTE_ADVERTISEMENT Capsule Format
IP Version: IP Version of this route advertisement. MUST be either
4 or 6.
IP Address: IP address of the advertised route. If the IP Version
field has value 4, the IP Address field SHALL have a length of 32
bits. If the IP Version field has value 6, the IP Address field
SHALL have a length of 128 bits.
IP Prefix Length: Length of the IP Prefix of the advertised route,
in bits. MUST be lesser or equal to the length of the IP Address
field, in bits.
Upon receiving the ROUTE_ADVERTISEMENT capsule, an endpoint MAY start
routing IP packets in that prefix to its peer.
3.2. ROUTE_REJECTION Capsule
The ROUTE_REJECTION capsule allows an endpoint to communicate to its
peer that it is not willing to route traffic to a given prefix. This
capsule uses a Capsule Type of 0xfff103. Its value uses the
following format:
ROUTE_REJECTION Capsule {
IP Version (8),
IP Address (32..128),
IP Prefix Length (8),
}
Figure 2: ROUTE_REJECTION Capsule Format
IP Version: IP Version of this route rejection. MUST be either 4 or
6.
IP Address: IP address of the rejected route. If the IP Version
field has value 4, the IP Address field SHALL have a length of 32
bits. If the IP Version field has value 6, the IP Address field
SHALL have a length of 128 bits.
IP Prefix Length: Length of the IP Prefix of the advertised route,
Chernyakhovsky, et al. Expires 28 February 2022 [Page 4]
Internet-Draft CONNECT-IP Routes August 2021
in bits. MUST be lesser or equal to the length of the IP Address
field, in bits.
Upon receiving the ROUTE_REJECTION capsule, an endpoint MUST stop
routing IP packets in that prefix to its peer. Note that this
capsule can be reordered with DATAGRAM frames, and therefore an
endpoint that receives packets for routes it has rejected MUST NOT
treat that as an error.
3.3. ROUTE_RESET Capsule
The ROUTE_RESET capsule allows an endpoint to cancel any routes it
had previously advertised or denied. This capsule uses a Capsule
Type of 0xfff104. Its value uses the following format:
ROUTE_RESET Capsule {
}
Figure 3: ROUTE_RESET Capsule Format
Upon receiving the ROUTE_RESET capsule, an endpoint MUST stop routing
IP packets to its peer. Note that this capsule can be reordered with
DATAGRAM frames, and therefore an endpoint that receives packets for
routes it has rejected MUST NOT treat that as an error.
The main purpose of the ROUTE_RESET capsule is to allow endpoints to
not have to remember the full list of routes they have shared with
their peer. In practice, it is expected that ROUTE_RESET capsules
will be closely followed by ROUTE_ADVERTISEMENT capsules that will
refill the routing table that was just cleared.
3.4. ATOMIC_START Capsule
The ATOMIC_START capsule allows an endpoint to create an atomic set
of capsules. This capsule uses a Capsule Type of 0xfff106. Its
value uses the following format:
ATOMIC_START Capsule {
}
Figure 4: ATOMIC_START Capsule Format
Upon receiving an ATOMIC_START capsule, an endpoint MUST buffer all
incoming known CONNECT-IP-specific capsules (i.e., capsules defined
in this document) until it receives an ATOMIC_END capsule. Endpoints
MUST NOT send two ATOMIC_START capsules without an ATOMIC_END capsule
between them.
Chernyakhovsky, et al. Expires 28 February 2022 [Page 5]
Internet-Draft CONNECT-IP Routes August 2021
Endpoints MUST NOT buffer unknown capsules. Endpoints MAY choose to
immediately process IP_PACKET and SHUTDOWN capsules instead of
buffering them. Capsules defined in other documents are by default
not buffered by ATOMIC_START. Extensions that register new capsule
types MAY specify that these capsules should be buffered by
ATOMIC_START, and whether it is allowed to skip buffering for them.
The purpose of this frame is to avoid timing issues where an endpoint
installs a route before an important route rejection was received.
Endpoints SHOULD group their initial configuration into an atomic
block to allow their peer to mark the tunnel as operational once the
whole block is parsed.
3.5. ATOMIC_END Capsule
The ATOMIC_END capsule allows an endpoint to end an atomic set of
capsules. This capsule uses a Capsule Type of 0xfff107. Its value
uses the following format:
ATOMIC_END Capsule {
}
Figure 5: ATOMIC_END Capsule Format
Upon receiving an ATOMIC_END capsule, an endpoint MUST parse all
previously buffered capsules, in order of receipt. Endpoints MUST
NOT send an ATOMIC_END capsule without a preceding ATOMIC_START
capsule.
4. Security Considerations
In theory, endpoints could use ROUTE_ADVERTISEMENT capsules to divert
traffic from naive endpoints. To avoid this, receivers of
ROUTE_ADVERTISEMENT capsules MUST check their local policy before
acting on such capsules, see Section 2.
5. IANA Considerations
5.1. Capsule Type Registrations
This document will request IANA to add the following values to the
"HTTP Capsule Types" registry created by [HTTP-DGRAM]:
Chernyakhovsky, et al. Expires 28 February 2022 [Page 6]
Internet-Draft CONNECT-IP Routes August 2021
+----------+---------------------+---------------------+---------------+
| Value | Type | Description | Reference |
+----------+---------------------+---------------------+---------------+
| 0xfff102 | ROUTE_ADVERTISEMENT | Route Advertisement | This document |
| 0xfff103 | ROUTE_REJECTION | Route Rejection | This document |
| 0xfff104 | ROUTE_RESET | Route Reset | This document |
| 0xfff106 | ATOMIC_START | Atomic Start | This document |
| 0xfff107 | ATOMIC_END | Atomic End | This document |
+----------+---------------------+---------------------+---------------+
6. References
6.1. Normative References
[HTTP-DGRAM]
Schinazi, D. and L. Pardue, "Using Datagrams with HTTP",
Work in Progress, Internet-Draft, draft-ietf-masque-h3-
datagram-03, 12 July 2021,
<https://datatracker.ietf.org/doc/html/draft-ietf-masque-
h3-datagram-03>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/rfc/rfc7230>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
6.2. Informative References
[CONNECT-IP]
Chernyakhovsky, A., McCall, D., and D. Schinazi, "The
CONNECT-IP HTTP Method", Work in Progress, Internet-Draft,
draft-cms-masque-connect-ip-02, 27 August 2021,
<https://datatracker.ietf.org/doc/html/draft-cms-masque-
connect-ip-02>.
Chernyakhovsky, et al. Expires 28 February 2022 [Page 7]
Internet-Draft CONNECT-IP Routes August 2021
[REQS] Chernyakhovsky, A., McCall, D., and D. Schinazi,
"Requirements for a MASQUE Protocol to Proxy IP Traffic",
Work in Progress, Internet-Draft, draft-ietf-masque-ip-
proxy-reqs-03, 27 August 2021,
<https://datatracker.ietf.org/doc/html/draft-ietf-masque-
ip-proxy-reqs-03>.
Appendix A. Examples
A.1. Consumer VPN
In this scenario, the client will typically receive a single IP
address that the proxy has picked from a pool of addresses it
maintains. The client will route all traffic through the tunnel.
The exchange could look as follows:
Client Server
ADDRESS_REQUEST -------->
IP Version = 4
IP Address = 0.0.0.0
IP Prefix Length = 0
<-------- ADDRESS_ASSIGN
IP Version = 4
IP Address = 192.0.2.42
IP Prefix Length = 32
<-------- ROUTE_ADVERTISEMENT
IP Version = 4
IP Address = 0.0.0.0
IP Prefix Length = 0
Acknowledgments
The design of CONNECT-IP was inspired by discussions in the MASQUE
working group around [REQS]. The authors would like to thank
participants in those discussions for their feedback.
Authors' Addresses
Alex Chernyakhovsky
Google LLC
1600 Amphitheatre Parkway
Mountain View, California 94043,
United States of America
Email: achernya@google.com
Chernyakhovsky, et al. Expires 28 February 2022 [Page 8]
Internet-Draft CONNECT-IP Routes August 2021
Dallas McCall
Google LLC
1600 Amphitheatre Parkway
Mountain View, California 94043,
United States of America
Email: dallasmccall@google.com
David Schinazi
Google LLC
1600 Amphitheatre Parkway
Mountain View, California 94043,
United States of America
Email: dschinazi.ietf@gmail.com
Chernyakhovsky, et al. Expires 28 February 2022 [Page 9]
