draft-ietf-sipcore-name-addr-guidance-00.txt   draft-ietf-sipcore-name-addr-guidance-01.txt 
Network Working Group R. Sparks Network Working Group R. Sparks
Internet-Draft Oracle Internet-Draft Oracle
Updates: 3261, 3325, 3515, 3892, 4508, February 28, 2017 Updates: 3261, 3325, 3515, 3892, 4508, May 10, 2017
5002, 5318, 5360, 5502 (if 5002, 5318, 5360, 5502 (if
approved) approved)
Intended status: Standards Track Intended status: Standards Track
Expires: September 1, 2017 Expires: November 11, 2017
Clarifications for when to use the name-addr production in SIP messages Clarifications for when to use the name-addr production in SIP messages
draft-ietf-sipcore-name-addr-guidance-00 draft-ietf-sipcore-name-addr-guidance-01
Abstract Abstract
RFC3261 constrained several SIP header fields whose grammar contains RFC3261 constrained several SIP header fields whose grammar contains
the "name-addr / addr-spec" alternative to use name-addr when certain the "name-addr / addr-spec" alternative to use name-addr when certain
characters appear. Unfortunately it expressed the constraints with characters appear. Unfortunately it expressed the constraints with
prose copied into each header field definition, and at least one prose copied into each header field definition, and at least one
header field was missed. Further, the constraint has not been copied header field was missed. Further, the constraint has not been copied
into documents defining extension headers whose grammar contains the into documents defining extension headers whose grammar contains the
alternative. alternative.
This document updates RFC3261 to state the constraint generically, This document updates RFC3261 to state the constraint generically,
and clarifies that the constraint applies to all SIP header fields and clarifies that the constraint applies to all SIP header fields
where there is a choice between using name-addr or addr-spec. It where there is a choice between using name-addr or addr-spec. It
also updates those extension SIP header fields that use the also updates the RFCs that define extension SIP header fields using
alternative to clarify that the constraint applies (RFCs 3325, 3515, the alternative to clarify that the constraint applies (RFCs 3325,
3892, 4508, 5002, 5318, 5360, and 5502). 3515, 3892, 4508, 5002, 5318, 5360, and 5502).
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 1, 2017. This Internet-Draft will expire on November 11, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 27 skipping to change at page 2, line 27
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Updates to RFC3261 . . . . . . . . . . . . . . . . . . . . . 3 2. Updates to RFC3261 . . . . . . . . . . . . . . . . . . . . . 3
3. Updates to RFCs defining SIP Extension header fields . . . . 4 3. Updates to RFCs defining SIP Extension header fields . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5
7. Instructions to the RFC Editor . . . . . . . . . . . . . . . 5 7. Instructions to the RFC Editor . . . . . . . . . . . . . . . 5
8. Normative References . . . . . . . . . . . . . . . . . . . . 5 8. Normative References . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
[RFC3261] defines several header fields that contain URIs to allow [RFC3261] defines several header fields that contain URIs to allow
both a form that contains the bare URI (addr-spec) and one that both a form that contains the bare URI (addr-spec) and one that
provides a name and the URI (name-addr). This subset, taken from the provides a name and the URI (name-addr). This subset, taken from the
ABNF [RFC5234] specified in [RFC3261] shows the relevant part of the ABNF [RFC5234] specified in [RFC3261] shows the relevant part of the
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sometimes failed to include the constraint. Many errata have been sometimes failed to include the constraint. Many errata have been
entered to correct this omission. When the constraint was called entered to correct this omission. When the constraint was called
out, the form has not been consistent. out, the form has not been consistent.
This memo updates the specifications of SIP and its extensions to This memo updates the specifications of SIP and its extensions to
clarify that the constraint to use the name-addr form applies clarify that the constraint to use the name-addr form applies
anywhere there is a choice between the name-addr and addr-spec anywhere there is a choice between the name-addr and addr-spec
production rules in the grammar for SIP header fields. production rules in the grammar for SIP header fields.
It is important to note that a message formed without honoring the It is important to note that a message formed without honoring the
constraint will still be syntactically valid, but would be constraint will still be syntactically valid, but would very likely
interpreted differently. The characters after the comma, question be interpreted differently. The characters after the comma, question
mark, or semicolon would be interpreted as header field parameters or mark, or semicolon will, in most cases, be interpreted as header
additional header field values as discussed in section 7.3.1 of field parameters or additional header field values as discussed in
[RFC3261]. section 7.3.1 of [RFC3261]. (An exception is the degenerate case of
a URL like sip:10.0.0.1,@10.0.0.0 where it is possible to parse the
comma via the 'user' production).
2. Updates to RFC3261 2. Updates to RFC3261
This text from the introduction to section 20 of [RFC3261]: This text from the introduction to section 20 of [RFC3261]:
The Contact, From, and To header fields contain a URI. If the URI The Contact, From, and To header fields contain a URI. If the URI
contains a comma, question mark or semicolon, the URI MUST be contains a comma, question mark or semicolon, the URI MUST be
enclosed in angle brackets (< and >). enclosed in angle brackets (< and >). Any URI parameters are
contained within these brackets. If the URI is not enclosed in
angle brackets, any semicolon-delimited parameters are
header-parameters, not URI parameters.
is replaced with: is replaced with:
When constructing the value of any SIP header field whose grammar When constructing the value of any SIP header field whose grammar
allows choosing between name-addr and addr-spec, such as those allows choosing between name-addr and addr-spec, such as those
that use the form '(name-addr / addr-spec)', the "addr-spec" form that use the form '(name-addr / addr-spec)', the "addr-spec" form
MUST NOT be used if its value would contain a comma, semicolon, MUST NOT be used if its value would contain a comma, semicolon,
or question mark. or question mark.
The header fields defined in this specification that allow this When a URI appears in such a header field, any URI parameters MUST
choice are "To", "From", "Contact", and "Reply-To". be contained within angle brackets (< and >). If the URI is not
enclosed in angle brackets, any semicolon-delimited parameters are
header-parameters, not URI parameters.
The header fields defined in this specification that allow this
choice are "To", "From", "Contact", and "Reply-To".
3. Updates to RFCs defining SIP Extension header fields 3. Updates to RFCs defining SIP Extension header fields
The following standards track RFCs: [RFC3515], [RFC3892], [RFC4508], The following standards track RFCs: [RFC3515], [RFC3892], [RFC4508],
and [RFC5360] and [RFC5360]
and the following informational RFCS: [RFC3325], [RFC5002], and the following informational RFCS: [RFC3325], [RFC5002],
[RFC5318], and [RFC5502] [RFC5318], and [RFC5502]
are updated to include: are updated to include:
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4. IANA Considerations 4. IANA Considerations
This memo has no considerations for IANA. This memo has no considerations for IANA.
5. Security Considerations 5. Security Considerations
The updates specified in this memo clarify a constraint on the The updates specified in this memo clarify a constraint on the
grammar for producing SIP messages. It introduces no new security grammar for producing SIP messages. It introduces no new security
considerations. One pre-existing consideration is worth reiterating: considerations. One pre-existing consideration is worth reiterating:
messages produced without honoring the constraint will be mis- messages produced without honoring the constraint will very likely be
interpreted by the receiving element. mis-interpreted by the receiving element.
6. Acknowledgments 6. Acknowledgments
Brett Tate identified this issue in several extension documents, Brett Tate identified this issue in several extension documents,
submitted several corresponding errata, and drove the discussion that submitted several corresponding errata, and drove the discussion that
led to this memo. Substantive comments leading to this text were led to this memo. Substantive comments leading to this text were
provided by Paul Kyzivat, Gonzalo Camarillo, and Dale Worley. provided by Paul Kyzivat, Gonzalo Camarillo, Dale Worley, and
Yehoshua Gev.
7. Instructions to the RFC Editor 7. Instructions to the RFC Editor
Please remove this section in its entirety before publication as an Please remove this section in its entirety before publication as an
RFC. RFC.
Please replace any instances of RFCxxxx with the RFC number assigned Please replace any instances of RFCxxxx with the RFC number assigned
to this memo. to this memo.
This memo, if it is approved, obviates Errata 3744, 3894, and This memo, if it is approved, obviates Errata 3744, 3894, and
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