RFC2167 - Referral Whois (RWhois) Protocol V1.5

Network Working Group S. Williamson

Request for Comments: 2167 M. Kosters

Obsoletes: RFC1714 D. Blacka

Category: Informational J. Singh

K. Zeilstra

Network Solutions, Inc.

June 1997

Referral Whois (RWhois) Protocol V1.5

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Abstract

This memo describes Version 1.5 of the client/server interaction of

RWhois. RWhois provides a distributed system for the discovery,

retrieval, and maintenance of Directory information. This system is

primarily hierarchical by design. It allows for the deterministic

routing of a query based on hierarchical tags, referring the user

closer to the maintainer of the information. While RWhois can be

considered a generic directory services protocol, it distinguishes

itself from other protocols by providing an integrated, hierarchical

architecture and query routing mechanism.

1. IntrodUCtion

Early in the development of the ARPANET, the SRI-NIC established a

centralized Whois database that provided host and network information

about the systems connected to the network and the electronic mail

(email) addresses of the users on those systems [RFC954]. The

ARPANET eXPeriment evolved into a global network, the Internet, with

countless people and hundreds of thousands of end systems. The sheer

size and effort needed to maintain a centralized database

necessitates an alternate, decentralized approach to storing and

retrieving this information.

The original Whois function was to be a central directory of

resources and people on ARPANET. However, it could not adequately

meet the needs of the expanded Internet. RWhois extends and enhances

the Whois concept in a hierarchical and scaleable fashion. In

accordance with this, RWhois focuses primarily on the distribution of

"network objects", or the data representing Internet resources or

people, and uses the inherently hierarchical nature of these network

objects (domain names, Internet Protocol (IP) networks, email

addresses) to more accurately discover the requested information.

RWhois synthesizes concepts from other, established Internet

protocols. The RWhois protocol and architecture derive a great deal

of structure from the Domain Name System (DNS) [RFC1034] and borrow

directory service concepts from other directory service efforts,

primarily [X.500]. The protocol is also influenced by earlier

established Internet protocols, such as the Simple Mail Transport

Protocol (SMTP) [RFC821].

This RWhois specification defines both a directory Access protocol

and a directory architecture. The directory access protocol

specifically describes the syntax of the client/server interaction.

It describes how an RWhois client can search for data on an RWhois

server, or how the client can modify data on the server. It also

describes how the server is to interpret input from the client, and

how the client should interpret the results returned by the server.

The architecture portion of this document describes the conceptual

framework behind the RWhois protocol. It details the concepts upon

which the protocol is based and describes its structural elements.

The protocol implements the architecture.

This document uses language like SHOULD and SHALL that have special

meaning as specified in "Key Words for use in RFCs to Indicate

Requirement Levels". [RFC2119]

2. Architecture

2.1 Overview

As a directory service, RWhois is a distributed database, where data

is split across multiple servers to keep database sizes manageable.

The architecture portion of this document details the concepts upon

which the protocol is based and describes its structural elements.

Specifically, the architecture is concerned with how the data is

split across the different servers. The basis of this splitting is

the lexically hierarchical label (or tag), which is a text string

whose position in a hierarchy can be determined from the structure of

the string itself.

All data can follow some sort of hierarchy, even if the hierarchy

seems somewhat arbitrary. For example, person names can be arranged

into hierarchical groups via geography. If all the people in

particular towns are grouped into town groups, then all of the town

groups can be grouped into state (or province) groups, and then all

of the state groups can be grouped into a country group. Then, a

particular name would belong in a town group, a state group, and a

country group. However, just given a name, it would be impossible to

determine where in the hierarchy it belongs. Therefore, a person

name is not lexically hierarchical.

However, there are certain types of data whose position in the

hierarchy can be determined by deciphering the data itself, for

example, phone numbers. A phone number is grouped according to

country code, area code, local exchange, and local extension. By

looking at a phone number, it is possible to determine to which of

all these groups the number belongs: 1-303-555-2367 is in country

code 1, area code 303, local exchange 555, and has a local extension

of 2367. Therefore, a phone number is lexically hierarchical.

On the Internet, two such types of data are widely used: domain names

and IP networks. Domain names are organized via a label-dot system,

reading from a more specific label to a more general label left to

right; for example, war.west.netsol.com is a part of west.netsol.com,

which is a part of netsol.com, which is a part of com. IP networks

are also lexically hierarchical labels using the Classless Inter-

Domain Routing (CIDR) notation, but their hierarchy is not easily

determined with simple text manipulation; for example, 198.41.0.0/22

is a part of 198.41.0.0/16, which is a part of 198.40.0.0/15.

Instead, an IP network's hierarchy is determined by converting the

network to binary notation and applying successively shorter bit

masks.

It is important to note that, while very little real data is

lexically hierarchical in nature, people often create label systems

(or namespaces) to help manage the data and provide an element of

uniqueness, for example, Social Security Numbers, ISBNs, or the Dewey

Decimal System. RWhois leverages lexically hierarchical labels,

domain names and IP networks, for its data splitting using the

concepts of authority areas and referrals. An authority area is

associated with an RWhois server and a lexically hierarchical label,

which is considered to be its name. An authority area is a piece of

the distributed database that speaks with authority about its

assigned part of the hierarchy. All data associated with a particular

lexically hierarchical tag should be located within that authority

area's database. Authority areas are further explained in Section

2.4.

RWhois directs clients toward the appropriate authority area by

generating referrals. Referrals are pointers to other servers that

are presumed to be closer to the desired data. The client uses this

referral to contact the next server and ask the same question. The

next server may respond with data, an error, or another referral (or

referrals). By following this chain of referrals, the client will

eventually reach the server with the appropriate authority area. In

the RWhois architecture, referrals are generated by identifying a

lexically hierarchical label and deciphering the label to determine

the next server. Referrals are further explained in Section 2.5.

When a number of RWhois servers containing authority areas are

brought on line and informed about each other, they form an RWhois

tree. The tree has a root authority area, which is the group that

contains all other groups. The root authority area must keep

pointers to the servers and authority areas that form the first level

of the hierarchy. The authority areas in the first level of the

hierarchy are then responsible for keeping pointers to the authority

areas below them and for keeping a pointer to the root.

2.2 Design Philosophy

The design goals for the RWhois protocol are as follows.

* It should be a directory access protocol. The server should be

able to access and update the data residing on it.

* It should facilitate query routing. An unresolved query should

be redirected to a server that is presumed to be closer to the

desired data.

* It should enable data replication. The server should be able to

duplicate its data on another server.

* The server should be lightweight and delegate more functions to

the client.

The concepts used to achieve these design goals are explained in the

remaining document.

2.3 Schema Model

As a directory service, RWhois uses various database schema to store

and represent data. Schema, in this document, has two definitions.

First, it refers to the entire structure of a database, all the

tables and fields forming a complete database. When schema is used in

this context, it is called the "database schema". Database schema

consists of attributes, classes, and objects. Schema may also refer

to a single piece of the database, a single table with fields. When

schema is used in this context, it is just called "schema" or it is

preceded by the name of the particular piece: contact schema or

domain schema, for example. In this usage, schema is equivalent to

"class", defined below.

There is no standard database schema in the RWhois architecture. Each

authority area is presumed to be able to define its own local schema.

However, an authority area that is part of a larger RWhois tree is

expected to have some part of its schema pertain to the lexically

hierarchical label upon which the RWhois tree is based. An authority

area schema may not change throughout much of an RWhois tree.

2.3.1 Attributes

An attribute is a named field and is the smallest typed unit in the

database schema. It is equivalent to a relational database's field.

An attribute is not considered to be data by itself; it is simply

used to give data a type. When a piece of data has been typed by an

attribute, it is typically referred to as a value and is represented

as an attribute-value pair. The RWhois syntax for the attribute-value

pair is to separate them with a colon, for example:

First-Name:Bill

Attributes have a number of properties, some mandated by the RWhois

protocol and some that are implementation dependent. These properties

are usually a reflection of the database system used by the server.

The following is a list of the protocol-mandated properties and their

descriptions.

Attribute This is the name of the attribute.

Description This is a natural language description of the

attribute.

Type This is a parameter that broadly indicates the use

of the attribute to the protocol. There are three

standard types: TEXT, ID, and SEE-ALSO. The default is

TEXT, which indicates that the value is a text string.

ID indicates that the attribute contains the ID of

another RWhois object. This type of attribute is used

for database normalization. SEE-ALSO indicates that

the attribute contains a pointer (a Uniform Resource

Identifier (URI)) to some other kind of external data;

for example, a World Wide Web page or FTP site.

Format This is an interpretable string that describes the

acceptance format of the value. The server (and

optionally the client) should match the value to the

format string to determine if the value is acceptable.

The format of this property is a keyword indicating the

syntax of the format string, followed by a colon,

followed by the format string itself. Currently, the

only keyword recognized is "re" for POSIX.2 extended

regular expressions.

Indexed This is a true or false flag indicating that this

attribute should be indexed (and therefore able to be

searched).

Required This is a true or false flag indicating that this

attribute must have a value in an instance of the

class.

Multi-Line This is a true or false flag indicating that this

attribute may have multiple instances in a class, but

all of the instances are to be considered as multiple

lines of the same attribute instance. This allows

normal line terminators to terminate values.

Repeatable This is a true or false flag indicating that there may

be multiple instances of this attribute in a class and

each instance is to be interpreted as a separate

instance (in contrast to Multi-Line). This flag is

mutually exclusive with Multi-Line: if Multi-Line is

true, then Repeatable must be false and vice versa.

Primary This is a true or false flag that indicates that this

attribute is a primary key. If more than one attribute

in a class is marked as primary, then these attributes

together form a single primary key. The primary key is

intended to be used to force uniqueness among class

instances. Therefore, there can be only one instance of

a primary key in a database. The Primary flag implies

that the attribute is also required.

Hierarchical This is a true or false flag that indicates that this

attribute is lexically hierarchical.

Private This is a true or false flag that indicates whether or

not this attribute is private (that is, publicly not

viewable). It defaults to false. If it is true, then

only the clients that satisfy the

authentication/encryption requirements of a guardian

(described below) are able to view the attribute-value

pair.

2.3.2 Class

A class is a collection of attributes; it is a structure, not data.

The concept is equivalent to that of a relational database table. It

is also equivalent to the second definition of schema, above.

A class also has some properties that are sometimes referred to as

its "meta" information. These properties are listed below.

Version This is a time/date stamp that is used to quickly detect

when a class definition has been changed.

Description This is a natural language description of the class.

2.3.3 Object

An object is an instance of a class. It is data with a type of

<class>.

2.3.4 Base Class

While RWhois does not have or advocate using a specific, standardized

schema, it does impose a few requirements. It requires that all

defined classes inherit attributes from a particular base class (or

base schema). The RWhois specification does not require the actual

implementation of inheritance. Instead, all classes must include the

attributes defined in the base class.

The base class has the following attributes.

Class-Name This attribute contains the name of the class to which

the object belongs. It is the type of the object

itself. It is of type TEXT and is required.

Auth-Area This attribute contains the name of the authority area

to which the object belongs. It, along with Class-

Name, definitively defines the type of the object. It

is of type TEXT and is required.

ID This attribute is a universal identifier for the

object. It is formed by choosing a string that is

unique within an authority area and appending the

authority area to it, separating the local string from

the authority area name with a period. The only

restrictions on the local string are that it must be

unique within the authority area and not contain the

period character. This attribute is hierarchical in

nature. It is always generated by the server (for

example, during a register operation). It is of type

TEXT and is required.

Updated This attribute is a time/date stamp that indicates the

time of last modification of the object. It is both

informational and a form of record locking. It

prevents two clients from modifying the same object at

the same time. It is of type TEXT and is required.

Guardian This attribute is a link to a guardian object

(described below). Its value is the ID of a guardian

object. It is of type ID and is optional. It is

repeatable, since an object may have multiple

guardians.

Private This attribute is a true or false flag that indicates

whether or not an object is private (that is, publicly

not viewable). It defaults to false. If it is true,

then only the clients that satisfy the

authentication/encryption requirements of one of the

object's guardians are able to view the object. If the

object is publicly viewable, then the Private

attribute property of each of its attributes still

applies.

TTL This attribute is the "time-to-live" of a given

object. It is included only if an object has a

different time-to-live than the default given in the

Start of Authority information. Its value is specified

in seconds. It is of type TEXT and is optional.

The RWhois specification defines two standard classes that should be

included in all implementations: the referral and guardian classes.

2.3.5 Referral Class

The referral class is defined to hold referral information (typically

for link referrals). It consists of attributes defined as part of the

base class, the protocol-specific attributes described below, and any

installation-specific attributes.

Referred-Auth-Area This attribute contains the name of the authority

area to which the referral points. It is used as

a search key during the query routing. It is of

type TEXT and is required. It is repeatable,

since referrals can point to servers hosting more

than one authority area.

Referral This attribute contains the referral itself. It

is an RWhois URL. It is of type TEXT and is

required. It is repeatable, since more than one

server can host a Referred-Auth-Area.

2.3.6 Guardian Class

The guardian class is defined to hold security information. The

fundamental concept behind the guardian class is that an object (or

another structure) is "guarded" by containing a pointer to a guardian

object [Guardian]. To modify, delete, or possibly view the guarded

object, the authentication (or encryption, or both) scheme must be

satisfied. Guardians are intended to not have rank: if an object is

guarded by more than one guardian object, satisfying any one of those

guardians is sufficient. A guardian object that does not have any

Guardian attribute linking it to other guardians guards itself. That

is, the authentication scheme in the guardian object itself must be

satisfied to modify, delete, or possibly view it.

Guardian objects are typically linked to actual database objects with

the Guardian attribute found in the base class. However, a guardian

may also be linked to an entire authority area, in which case the

guardian becomes implicitly linked to all of the objects contained

within the authority area.

The guardian class consists of the base class, the protocol-specific

attributes described below, and any installation-specific attributes.

Guard-Scheme This attribute contains a keyword indicating the

authentication methodology. Its value must be

understood by both the client and server, and its value

dictates the contents of the Guard-Info attribute. It

is of type TEXT and is required.

Guard-Info This attribute contains that data that is used by the

Guard-Scheme to verify the authentication. Its actual

format is dictated by the Guard-Scheme, for example, it

could contain a password or Pretty Good Privacy (PGP)

public key id [RFC1991]. For security reasons, it

should not be displayed, and its Private attribute

property should be set to true. It is of type TEXT and

is required.

2.4 Authority Areas

The concept of authority areas is pivotal to the RWhois architecture.

When an RWhois tree is created for a particular lexically

hierarchical namespace, the different pieces of the hierarchy are

mapped to authority areas. The most important concept behind an

authority area is the ability for a portion of the RWhois tree to

definitively control that portion of the hierarchy. This means that

an authority area is able to state whether or not a hierarchical tag

is in the whole RWhois tree. It does this either by returning the

object containing this tag, returning a referral to a sub-authority

area, or returning a response indicating that no objects were found.

This structure enables efficient routing of queries based on the

hierarchical label to the piece of the hierarchy responsible for it.

For example, in the domain name namespace as served by RWhois, the

root of the tree would be an authority area named ".", which would

delegate a "us" sub-authority area, which would delegate "va", "co",

"md", and "ca" authority areas, and so forth. When the server with

the "va.us" authority area is asked about "loudoun.va.us", it will be

able to authoritatively state that either no "loudoun.va.us" exists

or it will provide an object for or a referral to "loudoun.va.us".

Further, if the server is asked about "howard.md.us", it cannot

answer authoritatively, so it must provide a referral to its

hierarchical parent ("us" or the root).

This use of authority area strongly indicates where data should be

stored within an RWhois tree. Because RWhois uses a specific query

routing model, data needs to be placed under the proper authority

area. It is certainly possible to place a piece of data under the

wrong authority area, for example, putting an object for

"howard.md.us" under the "va.us" authority area. In such cases, the

data is considered to be misplaced and unable to be found within the

RWhois tree. However, while data should be placed under the lowest

(most specific) authority area, it is also possible that it could be

placed in a higher (least specific) authority area, for example,

putting an object for "loudoun.va.us" under the "us" authority. This

may be acceptable since, in most cases, the data would be able to be

found.

In addition to controlling a part of an RWhois hierarchy, an

authority area is considered to be autonomous. Each authority area is

treated as a separate database by the protocol. However, it is

recommended that an authority area share some core schema with the

rest of the RWhois tree for interoperability reasons. Each authority

area, however, is not bound by the database schema of its

hierarchical parent or by any of its sub-authority areas.

2.5 Query Routing

RWhois is not only a directory access protocol but it can also route

queries. Routing a query involves redirecting the query to another

server that is presumed to be closer to the desired data. To route a

query, the server first determines the location of the next server.

It then either forwards the query to that server and returns the

result to the client or returns the location of that server to the

client. The location of the server must contain its host name (or IP

address), port number, and authority area.

The location of the server to which a query is routed is called a

referral. There are two types of referrals: punt and link referrals.

A punt referral is a pointer to a server that is further up an RWhois

tree, and a link referral is a pointer to a server that is further

down the tree. For example, in Figure 1, when the server for the

"va.us" authority area routes a query up to the server for the "us"

authority area, it generates a punt referral. Alternatively, when it

routes a query down to the server for the "loudon.va.us" authority

area, it generates a link referral.

Query routing depends on whether or not the search value in a query

is lexically hierarchical. If the search value is hierarchical, the

server can generate punt or link referrals using the association of

authority areas with lexically hierarchical labels. Otherwise, the

server may send the query to a special index server that gathers the

indexing information for both hierarchical and non-hierarchical data

from the directory servers and returns referrals to these servers

[CIP]. If the server receives one or more referrals from the index

server, it should return them to the client.

It is important to note that the server may route a query whether it

could resolve the query or not. Even if a query has been resolved

locally, the server may also return referrals to the client by

sending the query to the index server. For example, if the server for

the "com" authority area receives the "domain Org-Name=IBM" query, it

may return all the domain objects for IBM within the "com" authority

area. In addition, it may also return referrals to the server for the

"nl" authority area if that server contains domain objects for IBM in

the Netherlands and has fed the corresponding indexing information to

the index server. This way the client can get back information for

both "ibm.com" and "ibm.nl" domains.

2.5.1 Query Routing Rules

An RWhois server routes a query based on certain rules. The objective

is to determine the location of a server to which to route the query.

A query may contain one or more query terms. The query routing rules

are applied on each query term until a referral is found. The rules

are listed below.

* Is the search value in the query term hierarchical? If not, go

to the next query term.

* Parse the hierarchical portion of the search value. Is it is

within one of the authority areas? If not, go to the next query

term.

* Does the found authority area have any referral objects

(instances of the referral class)? If not, return the "230 No

objects found" error to the client.

* Is the hierarchical portion of the search value within the

Referred-Auth-Area attribute of one of the referral objects? If

it is, return the value of the Referral attribute of the found

referral object as a link referral to the client.

* Are the search values of some of the query terms hierarchical

but not within any of the authority areas? If they are, return a

punt referral to the client.

* Are the search values of all the query terms non-hierarchical?

If they are, send the query to a special index server that

gathers the indexing information for both hierarchical and non-

hierarchical data from the directory servers and returns

referrals to these servers. If the server receives one or more

referrals from the index server, return them to the client.

Note that there can be more than one referral returned to the client.

These referrals may point to servers serving different authority

areas. The client may follow them in any order.

The pseudo code for the above rules is:

for each query term in the query

if the search value in the query term is hierarchical

if the search value is within one of the authority areas

if the search value is within one of the referred authority areas

the server sends link referral(s)

else

the server sends a "230 No objects found" error

endif

endfor

if the search values of some of the query terms are hierarchical but

not within any of the authority areas

the server sends Punt referral(s)

endif

if the search values of all the query terms are non-hierarchical

the server sends Referral(s) from an index server

endif

2.6 Data Replication

An RWhois server can replicate (duplicate) data from another RWhois

server on a per-authority area basis. Data replication makes the

RWhois service more reliable. Further, it increases throughput by

distributing queries to more than one server.

There can be two types of servers serving an authority area: a master

server and a slave server. A master server is where data is

registered for an authority area. It answers authoritatively to

queries in that authority area. There must be one and only one master

server for an authority area. A master server is also called a

primary server.

A slave server is where data is replicated from the master server for

an authority area. It also answers authoritatively to queries in that

authority area. There may be one or more slave servers for an

authority area. A slave server is also called a secondary server.

Note that a slave server must not register data for an authority

area.

It is recommended that the master and slave servers for an authority

area be geographically separate. Therefore, network unreachability at

one site will not completely shut down the RWhois service for that

authority area.

2.6.1 Data to Replicate

In RWhois, data is replicated on a per-authority area basis. The

smallest type of data a slave server can replicate is an attribute of

a class. Therefore, a slave server can replicate data for all the

classes, some classes, or some attributes of some classes.

The amount of data a slave server can replicate each time is either

all of the data or the data that has changed since the last

replication. The process of replicating all of the data is called

complete replication. The process of replicating the data that has

changed since the last replication is called incremental replication.

2.6.2 Start Of Authority Variables

Each authority area has some administrative variables, defined at the

master server, to control data replication. These variables are

called the Start Of Authority (SOA) variables. They are listed below.

Serial-Number This is the serial number of the data in an

authority area. The master server should update

this variable whenever the data in the authority

area is changed. Its value is a time/date stamp.

Refresh-Interval This is the time interval before a slave server

checks for complete replication. Its value is

specified in seconds.

Increment-IntervalThis is the time interval before a slave server

checks for incremental replication. Its value is

specified in seconds.

Retry-Interval This is the time interval before a slave server

tries again to connect to a master server that

appears to be out-of-service. Its value is

specified in seconds.

Time-To-Live This is the default time to live for the data in

an authority area at a slave server. The slave

server should not answer authoritatively to

queries for such stale data. Its value is

specified in seconds.

Admin-Contact This is the email address of an individual or a

role account responsible for the data integrity in

an authority area at the master server.

Tech-Contact This is the email address of an individual or a

role account responsible for the operation of the

master server for an authority area.

Hostmaster This is the email address of an individual or a

role account to whom email messages to update the

data in an authority area at the master server are

sent.

Primary-Server This is the location of the master server for an

authority area. Its value must contain both the

host name (or IP address) and port number of the

master server.

3. Protocol

3.1 Overview

The above sections describe the directory service architecture based

on the RWhois protocol. The remaining sections describe the syntax of

the protocol; the sequence and syntax of the information exchanged

between a server and a client. There are five types of information

that may be exchanged during a client/server session: directive,

response, query, result, and info.

3.1.1 Directive

A directive is a command that a client sends to a server to set a

control parameter for the session, get the meta-information (class

definitions and SOA information) about an authority area, or get the

data in an authority area. The first character of a directive must be

a "-". The server must support the "-rwhois" directive; all other

directives are optional. The server must indicate in the banner which

directives are implemented (see Section 3.1.9).

3.1.2 Response

A response is the information that a server returns to a client for a

directive. It is comprised of one or more lines, and the last line

always indicates the success or failure of the directive. The first

character of each response line must be a "%". If a server runs a

directive successfully, the last response line must be "%ok".

Otherwise, it must be "%error <error-code> <error-text>". A line with

the string "%ok" or "%error" in the first position must occur only

once in a server response and must always be the last line. The

server may send the "%info" response for special messages.

A client must understand the "%ok", "%error", and "%info" responses.

The client must also understand directive specific responses, if it

uses the related directives to communicate with the server. For

example, if the client sends the "-schema" directive to the server,

the client must understand the "%schema" response.

3.1.3 Query

A query is a command that a client sends to a server to access the

data in an authority area. The first character of a query must not be

a "-", since the server checks the first character of each command

from a client to determine whether it is a directive or a query.

3.1.4 Result

A result is the information that a server returns to a client for a

query. It can be either the accessed data or referrals to other

servers. It is comprised of one or more lines, and the last line

always indicates the success or failure of the query. If a server

returns either data or referrals for a query, the last result line

must be "%ok". Otherwise, it must be "%error <error-code> <error-

text>".

3.1.5 Info

An info message contains miscellaneous information that a server

sends to a client. The server may use it to send special messages,

for example a "message of the day" (MOTD), to the client. The first

info line must be "%info on", and the last info line must be "%info

off".

3.1.6 Client/Server Session

A typical RWhois client/server session has the following sequence of

messages.

* The client connects to the server.

* The server returns a banner identifying its protocol versions

and capabilities.

* The client sends one or more directives to the server.

* The server returns the response to each directive.

* The client finally sends a query to the server.

* The server returns the query results.

* The server closes the connection, unless the client has directed

it not to close the connection.

3.1.7 Examples

This section gives some common examples of the client/server

interaction. The notation in the examples uses a prefix to indicate

from where the information comes. A "C" indicates that the client

sends the data to the server. An "S" indicates that the server sends

the data to the client. The line is a comment when "#" is used. The

space after the prefix is not part of the data.

The following example illustrates a successful query.

# The client connects to the server.

# The server returns a banner identifying its protocol versions and

# capabilities.

S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)

# The client sends a directive to limit the number of search hits

# to 20.

C -limit 20

# The server returns a successful response.

S %ok

# The client sends a query to search for rwhois.net domain.

C domain rwhois.net

# The server returns the data for rwhois.net domain.

S domain:ID:dom-1.rwhois.net

S domain:Auth-Area:rwhois.net

S domain:Class-Name:domain

S domain:Updated:19970107201111000

S domain:Domain:rwhois.net

S domain:Server;I:hst-1.rwhois.net

S domain:Server;I:hst-2.rwhois.net

S %ok

# The server closes the connection.

The following example illustrates the link and punt referrals.

# The client connects to the server.

# The server returns a banner identifying its protocol versions and

# capabilities.

S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)

# The client sends a directive to hold the connection until it sends

# a directive to close the connection.

C -holdconnect on

# The server returns a successful response.

S %ok

# The client sends a query to search for a.b.rwhois.net domain.

C domain a.b.rwhois.net

# The server returns a link referral to a server serving the

# b.rwhois.net authority area.

S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net

S %ok

# The client sends a query to search for internic.net domain.

C domain internic.net

# The server returns a punt referral to a server serving the root

# authority area.

S %referral rwhois://rs.internic.net:4321/auth-area=.

S %ok

# The client sends a directive to close the connection.

C -quit

S %ok

# The server closes the connection.

The following example illustrates a query error.

# The client connects to the server.

# The server returns a banner identifying its protocol versions and

# capabilities.

S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)

# The client sends a query to search for c.rwhois.net domain.

C domain c.rwhois.net

# The server returns an error, since neither data nor referrals for

# c.rwhois.net domain are found within the rwhois.net authority area.

S %error 230 No objects found

# The server closes the connection.

3.1.8 Notation

The following sections use the Augmented Backus-Naur Form (ABNF)

notation to describe the syntax of the protocol. For further

information, see Section 2 of [RFC822]. The notation in the examples

uses a prefix to indicate from where the information comes. A "C"

indicates that the client sends the data to the server. An "S"

indicates that the server sends the data to the client. The line is a

comment when "#" is used. The space after the prefix is not part of

the data.

3.1.9 General ABNF definitions

Lexical Tokens

alpha = "a".."z" / "A".."Z"

digit = "0".."9"

hex-digit = digit / "a".."f" / "A".. "F"

id-char = alpha / digit / "_" / "-"

any-char = <ASCII 1..255,

except LF (linefeed) and CR (carriage return)>

dns-char = alpha / digit / "-"

email-char = <see [RFC822]>

space = " "

tab = <ASCII TAB (tab)>

lf = <ASCII LF (linefeed)>

cr = <ASCII CR (carriage return)>

crlf = cr lf

Grammar

year = 4digit

month = 2digit

day = 2digit

hour = 2digit

minute = 2digit

second = 2digit

milli-second = 3digit

host-name = dns-char *(dns-char / ".")

ip-address = 1*3digit "." 1*3digit "." 1*3digit "." 1*3digit

email = 1*email-char "@" host-name

authority-area = (dns-char / ".") *(dns-char / "." / "/")

object-id = 1*id-char "." authority-area

host-port = (host-name / ip-address) ":" 1*5digit

class-name = 1*id-char

attribute-name = 1*id-char

attribute-value = 1*any-char

time-stamp = year month day hour minute second milli-second

on-off = "on" / "off"

Note that the time-stamp must be in the Greenwich Mean Time (GMT)

time zone. Also note that since in the above any-char is 1..255

ASCII that the RWhois protocol is an 8 bit protocol.

Response

The general response for every directive and query is either "%ok" or

"%error". In addition, a "%info" response may be sent.

response = ok-response crlf / error-response crlf / info-response

ok-response = "%ok"

error-response = "%error" space error-code space error-text

error-code = 3digit

error-text = 1*any-char

info-response = "%info" space "on" crlf *(*any-char crlf) "%info"

space "off" crlf

Banner

The server must send a banner to the client when the connection is

opened. The banner contains the version(s) of the protocol the

server supports and a capability ID of encoded bit flags that

indicates which directives are implemented. If the server supports

more than one version of the protocol, the lowest-numbered version

must be specified first. The bits in extra-id are reserved for future

use. The end of the banner should contain a free-form string

indicating the name of the server implementation. A server must

support at least one version of the protocol, and may accept more

versions for compatibility reasons.

rwhois-banner = "%rwhois" space version-list space host-name

[space implementation] crlf

version-list = version *("," version)

version = version-number [":" capability-id]

/ "V-1.5" ":" capability-id

version-number = "V-" 1*digit "." 1*digit

capability-id = response-id ":" extra-id

response-id = 6hex-digit

extra-id = 2hex-digit

implementation = 1*any-char

Protocol

The entire RWhois protocol can be defined as a series of directives,

responses, queries, and results.

rwhois-protocol = client-sends / server-returns

client-sends = *(directives / rwhois-query)

server-returns = *(responses / rwhois-query-result)

3.2 Required Directives

The server must implement the following directives.

3.2.1 rwhois

Description

The "-rwhois" directive may be issued by the client at the start of

every session . It tells the server which version of the protocol the

client can handle. The server must respond with a banner containing

the protocol version and directives it implements. This banner is the

same banner that is sent by the server when the connection is opened,

except that the server must indicate only one version number. The

banner issued when opening a connection may contain more than one

version number. The directive flags are encoded into three octets,

which are described in Appendix D.

ABNF

rwhois-dir = "-rwhois" space version-number [space implementation]

crlf

rwhois-response = "%rwhois" space version space host-name

[space implementation] crlf

Errors

300 Not compatible with version

338 Invalid directive syntax

Examples

# When a connection is opened, the server issues the banner.

S %rwhois V-1.0,V-1.5:00ffff:00 rs.internic.net (NSI Server 1.5.4)

# The client sends the rwhois directive.

C -rwhois V-1.5 NSI Client 1.2.3

S %rwhois V-1.5:00ffff:00 rs.internic.net (NSI Server 1.5.4)

S %ok

3.3 Optional Directives

The server should implement the following directives.

3.3.1 class

Description

The "-class" directive can be used by the client to get the meta-

information for one or more classes in an authority area. The

response must contain the description and version number of each

specified class and may be expanded in the future with additional

attributes. When no class name is given, the server must return the

meta-information for all the classes in the authority area. Every

class record must end with an empty "%class" line.

ABNF

class-dir = "-class" space authority-area *(space class-name) crlf

class-response = *class-record response

class-record = *class-line "%class" crlf

class-line = "%class" space class-name ":" "description" ":"

1*any-char crlf

/ "%class" space class-name ":" "version" ":" time-stamp crlf

/ "%class" space class-name ":" meta-field ":" meta-value crlf

meta-field = 1*id-char

meta-value = 1*any-char

The following fields are required.

meta-field meta-value Description

description 1*any-char Class description.

Time/date stamp indicating version of class,

version time-stamp must be updated after class definition is

changed.

Errors

338 Invalid directive syntax

340 Invalid authority area

341 Invalid class

400 Directive not available

401 Not authorized for directive

Examples

C -class rwhois.net domain host

S %class domain:description:Domain information

S %class domain:version:19970103101232000

S %class

S %class host:description:Host information

S %class host:version:19970214213241000

S %class

S %ok

3.3.2 directive

Description

The "-directive" directive can be used by the client to get

information about the directives that the server supports. The

response must contain the name and description of each specified

directive and may be expanded in the future with additional

attributes. When no directive name is given, the server must return

information about all the directives. Every directive record must end

with an empty "%directive" line.

ABNF

directive-dir = "-directive" *(space directive-name) crlf

directive-name = 1*id-char

directive-response = *directive-record response

directive-record = "%directive" space "directive" ":" directive-name

crlf *directive-line "%directive" crlf

directive-line = "%directive" space "description" ":" 1*any-char crlf

/ "%directive" space attribute-name ":" attribute-value crlf

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

Without parameters:

C -directive

S %directive directive:rwhois

S %directive description:RWhois directive

S %directive

S %directive directive:quit

S %directive description:Quit connection

S %directive

S %ok

With parameters:

C -directive quit

S %directive directive:quit

S %directive description:Quit connection

S %directive

S %ok

3.3.3 display

Description

By default, the server uses the dump format for the output of a query

result. The output format can be changed with the "-display"

directive. When no parameter is given, the server must list all the

display formats it supports. Every display record must end with an

empty "%display" line.

Currently, only the dump format is standard and must be supported by

the server. Other output formats may be added in the future. See

Section 3.4 for the definition of the dump format.

ABNF

display-dir = "-display" crlf

/ "-display" space display-name crlf

display-name = 1*id-char

display-response = *(display-record) response

display-record = "%display" space "name" ":" display-name crlf

*display-line "%display" crlf

display-line = "%display" space attribute-name ":"

attribute-value crlf

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

436 Invalid display format

Examples

# Get the available display formats.

C -display

S %display name:dump

S %display

S %ok

# Change the active display format.

C -display dump

S %ok

3.3.4 forward

Description

The "-forward" directive instructs the server to follow all the

referrals and return the results to the client. This directive can be

used to run an RWhois server as a proxy server. The default value

must be "off". When the value is set to "on", the server must not

return referrals.

ABNF

forward-dir = "-forward" space on-off crlf

forward-response = response

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

C -forward on

S %ok

C -forward off

S %ok

3.3.5 holdconnect

Description

Normally, the server closes the connection after each query. This

behavior is controlled by the holdconnect state, which can be changed

with the "-holdconnect" directive. When the holdconnect state is set

to "off", the server must close the connection after a query; when it

is set to "on", the server must not close the connection after a

query. By default, the holdconnect state must be set to "off" for

each connection.

ABNF

holdconnect-dir = "-holdconnect" space on-off crlf

holdconnect-response = response

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

C -holdconnect on

S %ok

C -holdconnect off

S %ok

3.3.6 limit

Description

When returning a query result, the server should limit the number of

objects returned to the client. The "-limit" directive changes this

limit. The default and maximum limit is server-dependent. The client

can get the current limit by using the "-status" directive (see

Section 3.3.13).

ABNF

limit-dir = "-limit" space 1*digit crlf

limit-response = response

Errors

331 Invalid limit

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

C -limit 100

S %ok

3.3.7 notify

Description

The "-notify" directive performs several functions.

* If the server returns a referral that results in an error, the

client can report the bad referral to the server using the

"badref" option.

* When the client follows referrals and goes through the same

referral twice, that referral is a recursive referral and causes

a referral loop. The client can report the recursive referral to

the server using the "recurref" option.

* When the data in an authority area changes, a master server can

use the "update" option to notify its slave servers to update

the data.

* The "inssec" option allows an RWhois server to register itself

as a slave server for an authority area with a master server.

The master server may reject the request on the basis of its

registration policy.

* The "delsec" option allows a slave server to cancel its

registration with the master server.

ABNF

notify-dir = "-notify" space "badref" space referral-query crlf

/ "-notify" space "recurref" space referral-query crlf

/ "-notify" space "update" space host-port ":" authority-area crlf

/ "-notify" space "inssec" space host-port ":"

authority-area crlf

/ "-notify" space "delsec" space host-port ":"

authority-area crlf

referral-query = referral-url space [class-name space] query

notify-response = response

See Section 3.4 for the definitions of referral-url and query.

Errors

338 Invalid directive syntax

340 Invalid authority area

342 Invalid host/port

400 Directive not available

401 Not authorized for directive

Examples

# The client reports a bad referral to rwhois.Foobar.com to the

# server.

C -notify badref rwhois://rwhois.foobar.com:4321/auth-area=foobar.com

domain foobar.com

S %ok

# The client reports a recursive referral to rwhois.foobar.com to the

# server.

C -notify recurref rwhois://rwhois.foobar.com:4321/auth-area=

foobar.com contact Last-Name="Beeblebrox"

S %ok

# The master server for the foobar.com authority area notifies its

# slave servers to update the data.

C -notify update master.foobar.com:4321:foobar.com

S %ok

# The server rwhois2.foobar.com registers as a slave server for the

# foobar.com authority area.

C -notify inssec rwhois2.foobar.com:4321:foobar.com

S %ok

# The server rwhois2.foobar.com cancels its registration as a slave

# server for the foobar.com authority area.

C -notify delsec rwhois2.foobar.com:4321:foobar.com

S %ok

3.3.8 quit

Description

The "-quit" directive can be used by the client to close the

connection. Before the server closes the connection, it must respond

with "%ok".

ABNF

quit-dir = "-quit" crlf

quit-response = response

Errors

No errors.

Examples

C -quit

S %ok

3.3.9 register

Description

The "-register" directive can be used by the client to add, modify,

or delete objects in the server's database. The client must wait to

send the registration data until the "%ok" response is received from

the server. This directive has the following options.

* The "add" option indicates that the object being sent should be

added to the server's database.

* The "mod" option indicates that the object being sent is a

modification of an object that already resides on the server's

database. During a modify operation, the "_NEW_" tag is used to

delineate the end of the original (unmodified) object and the

beginning of the replacement object. That is, the identifying

characteristics of the original object are sent first, then the

"_NEW_" separator is sent, and then the entire replacement

object is sent.

The "del" option indicates that the object being sent should be

deleted from the server's database.

After a register operation (add, modify, or delete an object) in an

authority area, the server should update the "Serial-Number" variable

in the SOA information for the authority area. This is useful for

data replication because a slave server checks the "Serial-Number"

variable to detect a data change at the master server (see Section

3.6.2).

ABNF

/ register-on space "mod" space maintainer-id crlf

/ register-on space "del" space maintainer-id crlf

1*(register-line crlf)

maintainer-id = email

response

/ "%register" space "Updated" ":" time-stamp crlf response

/ response

* The server must return the register-on-response for the

"-register on" directive and the register-off-response for the

"-register off" directive.

* The maintainer-id identifies, for maintenance purposes, the

sender of registration information. The server should not use it

to authenticate the sender.

* For the "add" option, the client must send all the required

attributes for the object, including the Class-Name and Auth-

Area attributes. However, the client must not send the ID and

Updated attributes. These attributes are assigned by the server

and returned in the response.

* For the "mod" option, the client must send the identifying

information for the object to be modified, followed by the

"_NEW_" separator and the entire replacement object. The

identifying information must contain the ID and Updated

attributes; it may contain other attributes, but the server may

not check them. The ID, Auth-Area, and Class-Name attributes

must match in both the original object data and the replacement

object. The original object data is sent before the replacement

object to enable the server to lock the record in the database.

* For the "del" option, the client must send the identifying

information for the object to be deleted. The identifying

information must contain the ID and Updated attributes; it may

contain other attributes, but the server may not check them.

Errors

120 Registration deferred

320 Invalid attribute

321 Invalid attribute syntax

322 Required attribute missing

323 Object reference not found

324 Primary key not unique

325 Failed to update outdated object

336 Object not found

338 Invalid directive syntax

340 Invalid authority area

341 Invalid class

400 Directive not available

401 Not authorized for directive

Examples

# Add an object.

C -register on add joe@netsol.com

S %ok

C Class-Name:contact

C Auth-Area:a.com

C First-Name:Scott

C Last-Name:Williamson

C Name:Williamson, Scott

C Email:scottw@a.com

C -register off

S %register ID:23456789.a.com

S %register Updated:19961205224403000

S %ok

# Modify an object.

C -register on mod joe@netsol.com

S %ok

C ID:23456789.a.com

C Updated:19961205124403000

C _NEW_

C Class-Name:contact

C Auth-Area:a.com

C ID:23456789.a.com

C First-Name:Scott

C Last-Name:Williamson

C Name:Williamson, Scott

C Email:sw@a.com

C -register off

S %ok

# Delete an object.

C -register on del joe@netsol.com

S %ok

C ID:23456789.a.com

C Updated:19961205224403000

C -register off

S %ok

3.3.10 schema

Description

The "-schema" directive can be used by the client to get the

attribute definitions of one or more classes in an authority area. If

the client specifies class names, the server must return the

attribute definitions of the specified classes. Otherwise, the server

must return the attribute definitions of all the classes in the

authority area. Every schema record must end with an empty "%schema"

line.

ABNF

schema-dir = "-schema" space authority-area *(space class-name) crlf

schema-response = *schema-record response

schema-record = *schema-line "%schema" crlf

schema-line = "%schema" space class-name ":" attribute-name ":"

attribute-value crlf

Errors

338 Invalid directive syntax

340 Invalid authority area

341 Invalid class

400 Directive not available

401 Not authorized for directive

Examples

C -schema map

S %schema map:attribute:Class-Name

S %schema map:description:Type of the object

S %schema map:type:TEXT

S %schema map:format:re:[a-zA-Z0-9-]+

S %schema map:indexed:OFF

S %schema map:required:ON

S %schema map:multi-line:OFF

S %schema map:repeatable:OFF

S %schema map:primary:OFF

S %schema map:hierarchical:OFF

S %schema map:private:OFF

S %schema

S %schema map:attribute:ID

S %schema map:description:Globally unique object identifier

S %schema map:type:TEXT

S %schema map:format:re:[0-9]+.[a-zA-Z0-9.-]+

S %schema map:indexed:ON

S %schema map:required:ON

S %schema map:multi-line:OFF

S %schema map:repeatable:OFF

S %schema map:primary:ON

S %schema map:hierarchical:OFF

S %schema map:private:OFF

S %schema

# This is an abbreviated example, more attributes usually follow.

S %ok

3.3.11 security

Description

The "-security" directive enables either a client request or a server

response to be authenticated and/or encrypted. Currently, RWhois uses

two standard security methods: password and PGP. Password provides

authentication only, and PGP provides both authentication and

encryption. This directive can be used to securely access or update

any information (meta or data) in an authority area that is protected

by one or more guardian objects.

ABNF

security-dir = "-security" space "on" space direction space

security-method [space security-data] crlf

security-payload ["-security" space "off" crlf]

direction = "request" / "response"

security-method = "password" / "pgp" / 1*id-char

security-data = password-data / pgp-data / 1*any-char

password-data = 1*any-char

pgp-data = "signed" / "encrypt" [space key-id] / "signed-encrypt"

[space key-id]

security-payload = *(*any-char crlf)

security-response = response

* The "password" security-method is available in the "request"

direction only. For password, the security-data is a cleartext

password.

* The "pgp" security-method is available in both the "request" and

"response" directions. For PGP, the security-data indicates how

to treat the security-payload: signed, encrypted, or signed and

encrypted. To encrypt the security-payload in the "response"

direction, the security-data must include the public key ID with

which to encrypt it.

Errors

338 Invalid directive syntax

352 Invalid security method

353 Authentication failed

354 Encryption failed

400 Directive not available

401 Not authorized for directive

Examples

# Authenticate a request using password.

C -security on request password hello!1

S %ok

# Authenticate a PGP signed request.

C -security on request pgp signed

S %ok

C -register on mod joe@netsol.com

S %ok

C -----BEGIN PGP MESSAGE-----

C Version: 2.6.2

C owHrZJjKzMpgdP9D9crUhdpBYnwHGRnPbmVhmHlV7Hef9je/n7vyzhmE6589/+Dg

C jPpVm59tNz92vPSmrFB/4ankBRz+xgY+7z9OUYjefGahbWSNwzzxbw6TpWZGerU+

C uOUg/Cygs33JBdHqjwEc+wyfZPp+N5p2bu+ywoaOu8eLPyn+m2Mt/T9p1UaG68vP

C Zd2d9EPw+Ywpio7dco6yh3b/v7zmQxJHcWpyaVFmSSUDEHi6WBkZm5iamVtY6iXq

C JefnKnCFFQQklqSmWBlaWpoZGhmYGhqZmBgYGxgYKHA55yQWF+v6JeamWiXn55Uk

C JpcocDmWlmToOhalJlpB9cf7uYbHE6kWi/VumUXFJRB9wcn5JUBdPokwgfDMnJzM

C xNzi/DwFLjQBHQWoatfcxMwcq+JyB6h5AA==

C =a0sQ

C -----END PGP MESSAGE-----

C -register off

S %ok

# Encrypt a response using PGP. 52160EC1 is the public key ID with

# which the response is encrypted.

C -security on response pgp encrypt 52160EC1

S %ok

C -xfer com class=domain attribute=Domain-Name

attribute=Organization-Name

S -----BEGIN PGP MESSAGE-----

S Version: 2.6.2

S hIwDqWWhK1IWDsEBBACOXssTzD2CbB7Vjj2cNURScpJc2as2TbUDOQiwkT+8qFgG

S ZyRfktpwNNTawRIcGOk1Kcs84z8a3vvTA/oje9vZexHtzfJwBHFdiIZxPuCEpvgv

S 2ppK7WqlmHGcQKVBJJHYw7Fq83CUkeGJB9P1M3CQiXeW8h8MwAuhxSgbgt23PKYA

S AABuhknJrXeh9Owm81+MvyzgLOyM7sjDYmttU9sj/yuOYmAhS9V+34MT/Mwn4wO8

S 2BCsJqBHXbwOuYKs02p0se4jyKFtZR8MDPWNm9QyAP+oNMTjsufy6ZRa9PegUC6t

S HDhXymkiP03mKMMVK1//7X0=

S =vZ2x

S -----END PGP MESSAGE-----

S %ok

3.3.12 soa

Description

The "-soa" directive can be used by the client to retrieve the SOA

information for one or more authority areas. When no authority area

name is given, the server must return the SOA information for all the

authority areas. Every SOA record must end with an empty "%soa" line.

ABNF

soa-dir = "-soa" *(space authority-area) crlf

soa-response = *soa-record response

soa-record = *soa-line "%soa" crlf

soa-line = "%soa" space "authority" ":" authority-area crlf

/ "%soa" space "ttl" ":" 1*digit crlf

/ "%soa" space "serial" ":" time-stamp crlf

/ "%soa" space "refresh" ":" 1*digit crlf

/ "%soa" space "increment" ":" 1*digit crlf

/ "%soa" space "retry" ":" 1*digit crlf

/ "%soa" space "tech-contact" ":" email crlf

/ "%soa" space "admin-contact" ":" email crlf

/ "%soa" space "hostmaster" ":" email crlf

/ "%soa" space "primary" ":" host-port crlf

/ "%soa" space attribute-name ":" attribute-value crlf

The server must return the following SOA information for an authority

area.

attribute-name attribute-value Comments

authority authority-area This is the name of the authority area.

ttl 1*digit This is the default time to live for

the data in the authority area.

serial time-stamp This is the serial number of the data

in the authority area; it changes

when the data changes.

refresh 1*digit This is the time interval before a

slave server checks for complete

replication.

increment 1*digit This is the time interval before a

slave server checks for incremental

replication.

retry 1*digit This is the time interval before a

slave server tries again to connect

to a master server that appears to be

out-of-service.

tech-contact email This is the contact for the operation

of the master server.

admin-contact email This is the contact for the data

integrity at the master server.

hostmaster email This is the contact for sending update

requests at the master server.

primary host-port This is the host name (or IP address)

and port number of the master server.

Errors

338 Invalid directive syntax

340 Invalid authority area

400 Directive not available

401 Not authorized for directive

Examples

C -soa org

S %soa authority:org

S %soa ttl:86400

S %soa serial:19961119111535000

S %soa refresh:3600

S %soa increment:1800

S %soa retry:180

S %soa tech-contact:tech@internic.net

S %soa admin-contact:admin@internic.net

S %soa hostmaster:hostmaster@internic.net

S %soa primary:rs.internic.net:4321

S %soa

S %ok

3.3.13 status

Description

The "-status" directive can be used by the client to get various

status flags from the server. The response must include the number of

objects in all the authority areas, the current display format, the

server contact information, and the status flags for the state-

oriented directives: "-limit", "-holdconnect", and "-forward".

ABNF

status-dir = "-status" crlf

status-response = *status-line response

status-line = "%status" space "limit" ":" 1*digit crlf

/ "%status" space "holdconnect" ":" on-off crlf

/ "%status" space "forward" ":" on-off crlf

/ "%status" space "objects" ":" 1*digit crlf

/ "%status" space "display" ":" 1*any-char crlf

/ "%status" space "contact" ":" email crlf

/ "%status" space attribute-name ":" attribute-value crlf

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

C -status

S %status limit:20

S %status holdconnect:OFF

S %status forward:OFF

S %status objects:12345

S %status display:dump

S %status contact:joe@rwhois.net

S %ok

3.3.14 xfer

Description

The "-xfer" directive can be used by the client (generally, a slave

server) to transfer the data in an authority area. The client can

control the amount of data transferred using one of the following

options.

* serial-number: The client can transfer all the objects that have

been added, modified or deleted since a certain time, specifying

the serial-number that indicates that time. This option is used

for incremental replication.

* class: The client can limit the data transfer to one or more

classes, using the "class=<class-name>" option. The server must

return data for only the specified classes. If no class name is

specified, the server must return data for all the classes.

* attribute: The client can limit the data transfer to one or more

attributes of a class, using the "attribute=<attribute-name>"

option in combination with the "class=<class-name>" option. The

server must return data for only the specified attributes of the

class. The client can specify multiple "class=" and "attribute="

pairs.

ABNF

xfer-dir = "-xfer" space authority-area *attribute-def

[space serial-number] crlf

attribute-def = [space "class=" class-name] *(space "attribute="

attribute-name)

serial-number = time-stamp

xfer-response = *xfer-record response

xfer-record = *xfer-line "%xfer" crlf

xfer-line = "%xfer" space class-name ":" attribute-name ":"

attribute-value crlf

Errors

332 Nothing to transfer

333 Not master for authority area

338 Invalid directive syntax

340 Invalid authority area

341 Invalid class

342 Invalid attribute

400 Directive not available

401 Not authorized for directive

Examples

C -xfer com class=domain attribute=Domain-Name

attribute=Organization-Name

S %xfer domain:Domain-Name:acme.com

S %xfer domain:Organization-Name:Acme Inc.

S %xfer

S %xfer domain:Domain-Name:vogon.com

S %xfer domain:Organization-Name:Vogon Heavy Industries

S %xfer

S %ok

3.3.15 X

Description

The "-X" directive is used to specify an additional, non-standard

directive. It can be implemented by executing an external program, by

internal functions, or by other means. It may interact with the

client or simply produce output like one of the standard directives.

ABNF

x-dir = "-X-" x-directive [space x-arguments] crlf *x-line

x-directive = 1*id-char

x-arguments = *any-char

x-response = *(*any-char crlf) response

x-line = *any-char crlf

Errors

338 Invalid directive syntax

400 Directive not available

401 Not authorized for directive

Examples

The following example uses an implementation that executes an

external program, the UNIX "date" command. The server runs the "date"

command and returns its output to the client.

C -X-date

S Mon Jan 6 13:21:20 EST 1997

S %ok

3.4 Query

Description

The query allows the client to retrieve objects from the server's

database. The server must support the following types of queries.

* Unrestricted query: It is a single word or a quoted string. The

server must return all the matching objects where one or more

attributes match the query, regardless of the class.

* Class-restricted query: It is a class name specified in front

of the unrestricted query. The server must return all the

matching objects where one or more attributes of the specified

class match the query.

* Attribute-restricted query: It is of the

"<attribute-name>=<search-string>" form. The server must return

all the matching objects where the specified attribute matches

the query.

The server may implement the following types of queries.

* Boolean operator query: It consists of simpler queries combined

using the "and" and "or" operators.

* Wild card query: It consists of an asterisk ("*") in the front

and/or at the end of the search string. The server may support

partial matching using the asterisk.

In response to the query, the server will return the objects that

match the query. If the server does not support complex queries,

with, for example, wild cards or boolean operators, the server may

return the "351 Query too complex" error. When the number of objects

found exceeds the limit (set by the "-limit" directive), the server

should return the objects, followed by the "330 Exceeded maximum

objects limit" error.

The default object output format is the dump format that uses the

"<class-name>:<attribute-name>;<type character>:<attribute-value>"

form. The type character is optional and identifies the type of the

attribute value. The type character is a shorthand for the Type field

of the attribute definition (see Section 2.3.1). The type characters

are defined as follows.

Type Attribute

character Type

T TEXT

I ID

S SEE-ALSO

When no type character is given, the client should assume the "T"

type character. The server must provide the type character when the

attribute type is ID or SEE-ALSO. The purpose of the type character

is to aid the client in displaying the data. For example, when an

attribute value is an ID, the client may indicate to the end-user

that it is possible to retrieve the object indicated by the ID.

The server may return one or more referrals in the "%referral

rwhois://<host-name>:<port-number>/auth-area=<authority area>" form.

The client can distinguish multiple referrals by comparing their

authority areas; if all the referrals refer to the same authority

area, the client should follow only one of them. Otherwise, the

client should follow all of them. To follow a referral, the client

must connect to the specified host name and port number, and issue

the same query.

ABNF

rwhois-query = [class-name space] query crlf

query = query-string / attribute-query / query bin-boolean query

query-char = <any-char, except """, space, tab>

quoted-query-char = query-char / space / tab / "

query-string = ["*"] 1*query-char ["*"] / """ ["*"]

1*quoted-query-char ["*"] """

attribute-query = attribute-name "=" query-string

bin-boolean = "and" / "or"

rwhois-query-result = *(query-record / referral-record) response

query-record = 1*query-line crlf

query-line = class-name ":" attribute-name [";" type-char] ":"

attribute-value crlf

type-char = "T" / "I" / "S"

referral-record = 1*(referral-line crlf)

referral-line = "%referral" space referral-url

referral-url = "rwhois" ":" "//" host-port "/" "auth-area="

authority-area

Errors

130 Object not authoritative

230 No objects found

330 Exceeded maximum objects limit

340 Invalid authority area

341 Invalid class

342 Invalid attribute

350 Invalid query syntax

351 Query too complex

Examples

This example illustrates a query, where no objects are found.

C vogon

S %error 230 No objects found

This example illustrates a query, where two different objects are

returned.

C ibm

S domain:ID:IBMLIFEPRO-DOM.com

S domain:Auth-Area:com

S domain:Domain-Name:IBMLIFEPRO.COM

S domain:Org-Name:IBM

S domain:Server;I:NS12345-HST.NET

S domain:Admin-Contact;I:TW1234.COM

S domain:Tech-Contact;I:BN123.NET

S domain:Updated:19961120123455000

S domain:Updated-By:autoreg@internic.net

S domain:Class-Name:domain

S network:ID:NET-IBMNET-3.0.0.0/0

S network:Auth-Area:0.0.0.0/0

S network:Network-Name:IBMNET-3

S network:IP-Network:123.45.67.0/24

S network:Org-Name:IBM

S network:Street-Address:1234 Maneck Avenue

S network:City:Black Plains

S network:State:NY

S network:Postal-Code:12345

S network:Country-Code:US

S network:Tech-Contact;I:MG305.COM

S network:Updated:19931120123455000

S network:Updated-By:joeblo@nic.ddn.mil

S network:Class-Name:network

S %ok

This example illustrates a query with a class restrictor, where the

number of objects found exceeds the limit set by the "-limit"

directive.

C -limit 1

S %ok

C domain ibm

S domain:ID:IBMLIFEPRO-DOM.com

S domain:Auth-Area:com

S domain:Domain-Name:IBMLIFEPRO.COM

S domain:Org-Name:IBM

S domain:Server;I:NS12345-HST.NET

S domain:Admin-Contact;I:TW1234.COM

S domain:Tech-Contact;I:BN123.NET

S domain:Updated:19961120123455000

S domain:Updated-By:erice@internic.net

S domain:Class-Name:domain

S %error 330 Exceeded maximum objects limit

This is an example of attribute matching.

C domain Domain-Name=konabo.com

S domain:ID:12345678.com

S domain:Auth-Area:com

S domain:Domain-Name:konabo.com

S domain:Org-Name:ACME

S domain:Server;I:12345670.com

S domain:Server;I:12345671.com

S domain:Admin-Contact;I:12345660.com

S domain:Tech-Contact;I:12345665.com

S domain:Updated:19961120123455000

S domain:Updated-By:joeblo@internic.net

S domain:Class-Name:domain

S %ok

This example illustrates a link referral.

C domain a.b.rwhois.net

# The server returns a link referral to a server serving the

# b.rwhois.net authority area.

S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net

S %ok

This example illustrates a punt referral.

C domain internic.net

# The server returns a punt referral to a server serving the root

# authority area.

S %referral rwhois://rs.internic.net:4321/auth-area=.

S %ok

This example illustrates multiple referrals that refer to the same

authority area. The client should follow only one of them.

C domain a.b.rwhois.net

# The server returns link referrals to two RWhois servers serving the

# b.rwhois.net authority area.

S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net

S %referral rwhois://slave.b.rwhois.net:4321/auth-area=b.rwhois.net

S %ok

This example illustrates multiple referrals that refer to different

authority areas. The client should follow all of them.

C contact Last-Name="Beeblebrox"

# The server returns a link referral to a server serving the

# b.rwhois.net authority area.

S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net

# The server also returns a punt referral to a server serving the

# net authority area since the query matched an entry in the

# non-hierarchical index received from it.

S %referral rwhois://rs.internic.net:4321/auth-area=net

S %ok

This is an example of a boolean operator and wildcard matching.

C ibm and jubliana*

S host:ID:JUBLIANA-HST.root

S host:Auth-Area:.

S host:Host-Name:JUBLIANA.TRL.IBM.CO.JP

S host:IP-Address:123.156.220.68

S host:Org-Name:IBM

S host:Street-Address:1234 Maneck Avenue

S host:City:Black Plains

S host:State:NY

S host:Postal-Code:12345

S host:Country-Code:US

S host:Updated:19961120123455000

S host:Updated-By:joeblo@nic.ddn.mil

S host:Class-Name:host

S %ok

3.5 Connection Model

An RWhois client can connect to an RWhois server using one of the

following transport protocols.

3.5.1 Transmission Control Protocol (TCP)

TCP provides a reliable stream transport service between a client and

a server. In RWhois, TCP is the default transport protocol because,

during a particular session, a client can send more than one query

and a server can reliably return a large amount of data for each of

those queries. By default, a TCP RWhois server should run on the

standard, Internet Assigned Number Authority (IANA)-assigned port

4321. However, if port 4321 is not available, it may run on an

available port in the non-reserved range (1024 - 65535).

3.5.2 User Datagram Protocol (UDP)

UDP provides an unreliable connectionless transport service between a

client and a server. In RWhois, UDP may be used as the transport

protocol if a client wants to quickly send only one query, without

incurring the overhead of establishing a TCP connection with a

server. By default, a UDP RWhois server should run on the standard,

IANA-assigned port 4321. However, if port 4321 is not available, it

may run on an available port in the non-reserved range (1024 -

65535). A separate document will describe the use of UDP as the

transport protocol in RWhois.

3.6 Data Replication

This section discusses when and how a slave server should replicate

data. Further, it describes the server registration and location

mechanisms.

3.6.1 When to Replicate Data

The time when a slave server may replicate data for an authority area

is determined by the SOA variables for that authority area. The

possible times are the following.

* When the "Refresh-Interval" expires, a slave server may

completely replicate data.

* When the "Increment-Interval" expires, a slave server may

incrementally replicate data.

* A slave server fails to connect to its master server to

replicate data. When the "Retry-Interval" expires, it tries

again to replicate data.

* When the data in an authority area is changed and its "Serial-

Number" updated, a master server may notify its slave servers to

immediately update the data. To notify about the data change,

the master server should send the "-notify update <host-

name>:<port-number>:<authority-area>" directive to its slave

servers.

3.6.2 How to Replicate Data

To replicate data, a slave server sends a series of directives to its

master server and checks each response before sending the next

directive. The following sections describe the protocols for

complete and incremental replication.

Complete Replication

The protocol between a master server and a slave server to completely

replicate data for an authority area is as follows.

1. The slave server should connect to the master server. If there

is a connection error, the slave server should log an error and

exit.

2. The slave server should send the "-soa <authority-area>"

directive to the master server and parse the SOA variables from

the response. Let the "Serial-Number" variable in this response

be called the "old-serial-number".

3. The slave server should send the "-class <authority-area>"

directive to the master server and parse the versions of all the

classes from the response.

4. The slave server should send the "-schema <authority-area>"

directive to the master server and parse the definitions of all

the classes from the response.

5. The slave server should send the "-xfer <authority-area>"

directive to the master server and parse the data objects from

the response. The master server should return all the data

objects, excluding the deleted ones, in the authority area. The

slave server should index these data objects.

6. When the "Refresh-Interval" expires, the slave server should

to the master server. If there is a connection error, the slave

server should try again after the "Retry-Interval".

7. The slave server should send the "-soa <authority-area>"

directive to the master server and parse the SOA variables from

the response. Let the "Serial-Number" variable in this response

be called the "new-serial-number". If the "new-serial-number" is

not greater than the "old-serial-number", go back to step 6.

Otherwise, it indicates a data change at the master server.

8. The slave server should send the "-class <authority-area>"

directive to the master server and parse the versions of all the

classes from the response. If the version of any of the classes

has changed, the slave server should send the "-schema

<authority-area>" directive to the master server and parse the

definitions of all the classes from the response.

9. The slave server should send the "-xfer <authority-area>"

directive the master server and parse the data objects from the

response. The master server should return all the data objects,

excluding the deleted ones, in the authority area. The slave

server should index these data objects and seamlessly replace

the old index with the new one. Further, it should assign the

"new-serial-number" to the "old-serial-number".

10. Go back to step 6.

Note that the "-class", "-schema", and "-xfer" directives change when

a slave server replicates data for only a subset of the schema for an

authority area.

In the following example, a slave server completely replicates data

for all the classes in an authority area. The notation in the example

uses a prefix to indicate from where the information is coming. An

"M" indicates that the master server sends the data to the slave

server. An "S" indicates that the slave server sends the data to the

master server. The line is a comment when "#" is used. The space

after the prefix is not part of the data. The example authority area

is "rwhois.net".

# The slave server connects to the master server.

M %rwhois V-1.5:00ffff:00 master.rwhois.net

S -soa rwhois.net

M ...

M %soa serial:19970103102258000

M %soa refresh:3600

M ...

S -class rwhois.net

# The master server returns the versions of all the classes in the

# rwhois.net authority area.

S -schema rwhois.net

# The master server returns the definitions of all the classes in the

# rwhois.net authority area.

S -xfer rwhois.net

# The master server returns all the data objects, excluding the

# deleted ones, in the rwhois.net authority area. The slave server

# indexes these data objects.

# The refresh interval of 3600 seconds expires.

S -soa rwhois.net

M ...

M %soa serial:19970103103258000

M %soa refresh:3600

M ...

# The new serial number 19970103103258000 is greater than the old

# serial number 19970103102258000. It indicates a data change at the

# master server.

S -class rwhois.net

# The master server returns the versions of all the classes in the

# rwhois.net authority area. If the version of any of the classes has

# changed, the slave server logs an error and closes the connection.

S -xfer rwhois.net

# The master server returns all the data objects, excluding the

# deleted ones, in the rwhois.net authority area. The slave server

# indexes these data objects and seamlessly replaces the old index.

# The refresh interval of 3600 seconds expires.

S ...

Incremental Replication

The protocol between a master server and a slave server to

incrementally replicate data for an authority area is as follows.

1. The slave server should connect to the master server. If there

is a connection error, the slave server should log an error and

exit.

2. The slave server should send the "-soa <authority-area>"

directive to the master server and parse the SOA variables from

the response. Let the "Serial-Number" variable in this response

be called the "old-serial-number".

3. The slave server should send the "-class <authority-area>"

directive to the master server and parse the versions of all the

classes from the response.

4. The slave server should send the "-schema <authority-area>"

directive to the master server and parse the definitions of all

the classes from the response.

5. The slave server should send the "-xfer <authority-area>"

directive to the master server and parse the data objects from

the response. The master server should return all the data

objects, excluding the deleted ones, in the authority area. The

slave server should index these data objects.

6. When the "Increment-Interval" expires, the slave server should

connect to the master server. If there is a connection error,

the slave server should try again after the "Retry-Interval".

7. The slave server should send the "-soa <authority-area>"

directive to the master server and parse the SOA variables from

the response. Let the "Serial-Number" variable in this response

be called the "new-serial-number". If the "new-serial-number" is

not greater than the "old-serial-number", go back to step 6.

Otherwise, it indicates a data change at the master server.

8. The slave server should send the "-class <authority-area>"

directive to the master server and parse the versions of all the

classes from the response. If the version of any of the classes

has changed, the slave server should send the "-schema

<authority-area>" directive to the master server and parse the

definitions of all the classes from the response. The slave

server should then send the "-xfer <authority-area>" directive

to the master server and parse the data objects from the

response. The master server should return all the data objects,

excluding the deleted ones, in the authority area. The slave

server should index these data objects and seamlessly replace

the old index with the new one. Further, it should assign the

"new-serial-number" to the "old-serial-number". If the version

of any of the classes has changed, go back to step 6.

9. The slave server should send the "-xfer <authority-area>

<old-serial-number>" directive to the master server and parse

the data objects from the response. The master server should

return all the data objects in the authority area that have been

inserted, updated, or deleted since the "old-serial-number". The

slave server should index all the data again after purging stale

data objects and seamlessly replace the old index with the new

one. Further, it should assign the "new-serial-number" to the

"old-serial-number".

10. Go back to step 6.

Note that the "-class", "-schema", and "-xfer" directives change when

a slave server replicates data for only a subset of the schema for an

authority area.

In the following example, a slave server incrementally replicates

data for all the classes in an authority area. The notation in the

example uses a prefix to indicate from where the information is

coming. An "M" indicates that the master server sends the data to the

slave server. An "S" indicates the slave server sends the data to the

master server. The line is a comment when "#" is used. The space

after the prefix is not part of the data. The example authority area

is "rwhois.net".

# The slave server connects to the master server.

M %rwhois V-1.5:00ffff:00 master.rwhois.net

S -soa rwhois.net

M ...

M %soa serial:19970103102258000

M %soa increment:1800

M ...

S -class rwhois.net

# The master server returns the versions of all the classes in the

# rwhois.net authority area.

S -schema rwhois.net

# The master server returns the definitions of all the classes in the

# rwhois.net authority area.

S -xfer rwhois.net

# The master server returns all the data objects, excluding the

# deleted ones, in the rwhois.net authority area. The slave server

# indexes these data objects.

# The increment interval of 1800 seconds expires.

S -soa rwhois.net

M ...

M %soa serial:19970103103258000

M %soa increment:1800

M ...

# The new serial number 19970103103258000 is greater than the old

# serial number 19970103102258000. It indicates a data change at

# the master server.

S -class rwhois.net

# The master server returns the versions of all the classes in the

# rwhois.net authority area. If the version of any of the classes has

# changed, the slave server logs an error and closes the connection.

S -xfer rwhois.net 19970103102258000

# The master server returns all the data objects in the rwhois.net

# authority area that have been inserted, updated, or deleted since

# 19970103102258000. The slave server indexes all the data again

# after purging stale data objects and seamlessly replaces the old

# index. The increment interval of 1800 seconds expires.

S ...

3.6.3 Server Registration

This section discusses how an RWhois server can register itself or

cancel its registration as a slave server for an authority area with

a master server.

The initial list of slave servers for an authority area should be

manually configured at the master server. To register itself as a

slave server, the server should send the "-notify inssec <host-

name>:<port-number>:<authority-area>" directive to the master server.

The master server may reject the request on the basis of its

registration policy. To cancel its registration as a slave server,

the server should send the "-notify delsec <host-name>:<port-

number>:<authority-area>" directive to the master server. Note that

the "host-name" and "port-number" in the above directives correspond

to the requesting server.

3.6.4 Server Location

To resolve a query in a particular authority area, an RWhois client

may need to first locate the master and slave servers for that

authority area. The different server location mechanisms are as

follows.

Referrals

An RWhois client should know about at least one RWhois server. It

should send the "referral <authority-area>" query to that server. The

query may be routed up or down the RWhois tree before getting

resolved. If the query does get resolved, the result should be a

referral object for that authority area. The client should parse the

"Referral" attributes from the result to oBTain a list of servers

serving that authority area.

The client should then send the "-soa <authority-area>" directive to

one of the above servers and parse the "Primary-Server" variable from

the response. The value of this variable is the master server. Then,

the remaining servers in the list are the slave servers.

SRV RRs

The Server Resource Record (SRV RR), defined for DNS, can be used to

locate the master and slave servers for an authority area. An SRV RR

specifies the location of a network service in an organization's DNS.

It is defined in [RFC2052] as follows.

Service.Proto.Name TTL Class SRV Priority Weight Port Target

Since an authority area identifier is generally a domain name or an

IP address, the RWhois SRV RRs can be added to the DNS file for that

domain or IP address. For example, the RWhois SRV RRs for the

"rwhois.net" authority area could be:

rwhois.tcp.rwhois.net. 86400 IN SRV 10 0 4321 master.rwhois.net.

SRV 20 0 4322 slave.rwhois.net.

where the "master.rwhois.net" server has a higher priority than the

"slave.rwhois.net" server. The client must try to connect to the

server with a higher (lower-numbered) priority.

4. Security Considerations

RWhois provides security using the guardian class (see Section

2.3.6). Any information (meta or data) in an authority area can be

guarded by containing pointers to one or more guardian objects; that

is, it can be securely updated and accessed. Currently, there are two

standard security methods: password and PGP (see Section 3.3.11).

Password provides authentication only, and PGP provides both

authentication and encryption. PGP is the recommended security

method in RWhois.

The following sections discuss how to securely update and access the

data in an authority area.

4.1 Data Update

This involves the ability to securely add, modify, or delete some

information (meta or data) in an authority area. An authority area,

on the whole, can be guarded by linking guardians to its SOA and

schema information. Only these guardians should be allowed to add

objects to the authority area and modify its SOA and schema

information. In addition, they can also modify or delete existing

objects in the authority area. However, the function of modifying or

deleting existing objects can be delegated to other guardians by

linking them to objects on a per-object basis.

4.2 Access Control

There are two access control issues; the first is the ability to

securely transfer data between the slave and master servers. To

transfer data for an authority area, a slave server can authenticate

itself by satisfying one of the guardians linked to the SOA

information of the authority area at the master server. In addition,

the master server may encrypt the transferred data.

The second issue is the ability to make public only a subset of the

data in an authority area. If all the objects of a particular class

need to be private, the Private attribute of the class should be set

to true. If only some attributes of all the objects of a particular

class need to be private, the Private attribute property of each of

those attributes should be set to true. The guardians of such objects

must be able to view them completely.

5. Acknowledgments

The authors would like to acknowledge the following individuals.

Stan Borinski

C. Ming Lu

Leslie Meador

Michael Mealling

Greg Pierce

Amar Rao

6. References

[CIP] Allen, J., "The Common Indexing Protocol (CIP)", Bunyip

Information Systems, November 1996, Work in Progress.

[Guardian] Singh, J., M. Kosters, "The InterNIC Guardian Object",

ftp://rs.internic.net/policy/internic/internic-gen-1.txt, Network

Solutions, February 1996.

[RFC821] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC

821, ISI, August 1982.

[RFC822] Crocker, D, "Standards for the Format of ARPA Internet Text

Messages", STD 11, RFC822, University of Delaware, August 1982.

[RFC954] Harrenstien, K., Stahl, M., Feinler, E., "NICNAME/WHOIS",

RFC954, SRI, October 1985.

[RFC1034] Mockapetris, P. V., "Domain names - concepts and

facilities", STD 13, RFC1034, November 1987.

[RFC1714] Williamson, S., Kosters, M., "Referral Whois Protocol",

RFC1714, Network Solutions, November 1994.

[RFC1738] T. Berners-Lee, L. Masinter, M. McCahill, "Uniform

Resource Locators (URL)", RFC1738, CERN, Xerox Corporation,

University of Minnesota, December 1994.

[RFC1991] Atkins, D., W. Stallings, P. Zimmermann, "PGP Message

Exchange Formats", RFC1991, MIT, Comp-Comm Consulting, Boulder

Software Engineering, August 1996.

[RFC2052] Gulbrandsen, A., P. Vixie, "A DNS RR for specifying the

location of services (DNS SRV)", RFC2052, Troll Technologies, Vixie

Enterprises, October 1996.

[X.500] "The Directory: Overview of Concepts, Models and Service",

CCITT Recommendation X.500, 1988.

Authors' Addresses

Scott Williamson (scottw@rwhois.net)

Mark Kosters (markk@internic.net)

David Blacka (davidb@rwhois.net)

Jasdip Singh (jasdips@rwhois.net)

Koert Zeilstra (kzeil@rwhois.net)

Postal Address:

505 Huntmar Park Drive

Herndon, VA 22070-5100

Telephone: 703-742-0400

Appendix A: Glossary Of Terms

ABNF: Augmented Backus-Naur Form. Refined version of BNF, defined in

[RFC822]. See BNF.

Attribute: A named field and the smallest typed unit in a database

schema. See Database Schema.

Authority Area: An autonomous part of an RWhois tree. It is

associated and named after a particular piece of a hierarchy and is

able to state authoritatively whether or not an instance of

hierarchical data is present within the RWhois tree. See RWhois Tree.

Banner: A line sent by a server indicating which protocol versions it

supports and which directives are implemented. This line is issued by

the server after a connection is opened and as a response to the "-

rwhois" directive. See Directive and Response.

Base Class: A class from which all defined classes in a database

schema inherit attributes. See Attribute, Class, and Database Schema.

BNF: Backus-Naur Form. Language to precisely define the syntax of

protocols and computer languages.

Class: A collection of attributes. See Attribute.

Complete Replication: The process of replicating all of the data for

an authority area. See Replication.

Database Schema: A collection of all the classes forming an RWhois

database. See Class.

Directive: A command that a client sends to a server to set a control

parameter for the session, get the meta-information (class

definitions and SOA information) about an authority area, or get the

data in an authority area. See Class and SOA.

Guardian Class: A standard class that contains security information.

An object is guarded by containing a pointer to a guardian object.

See Class and Object.

Incremental Replication: The process of replicating the data that has

changed since the last replication for an authority area. See

Replication.

Info: The miscellaneous information that a server sends to a client.

Lexically Hierarchical Label: A text string whose position in a

hierarchy is encoded in the string itself.

Link Referral: A pointer to another server that is further down an

RWhois tree. It is used to route a query down the tree. See Referral

and RWhois Tree.

Master Server: A server where the data is registered for an authority

area. It answers authoritatively to queries in the authority area.

It is also called a primary server. See Authority Area.

Namespace: A particular naming system defined by a set of rules

describing the format of a name. Alternately, all of the names

satisfying the rules.

Object: An instance of a class. It is data with a type of <class>.

See Class.

PGP: Pretty Good Privacy. An authentication and encryption scheme.

Primary Server: See Master Server.

Punt Referral: A pointer to another server that is further up an

RWhois tree. It is used to route a query up the tree. See Referral

and RWhois Tree.

Query: A command that a client sends to a server to access the data

in an authority area.

Query Routing: Redirecting a query to another server for resolution.

See Query.

Referral: A pointer to another server that is presumed to be closer

to the desired data. It is used to route a query. See Query Routing.

Referral Class: A standard class that contains referral information

for an authority area. See Class and Referral.

Replication: A server duplicating data from another server on a per-

authority area basis. See Authority Area.

Response: The information that a server returns to a client for a

directive. See Directive.

Result: The information that a server returns to a client for a

query. It can be either the accessed data or referrals to other

servers. See Query and Referral.

RWhois Tree: A data information tree of RWhois servers where the data

is arranged hierarchically in the authority areas. See Authority

Area.

Schema: See Class.

Secondary Server: See Slave Server.

Slave Server: A server where the data is replicated from the master

server for an authority area. It also answers authoritatively to

queries in the authority area. It is also called a secondary server.

See Master Server.

SOA: Start Of Authority. Administrative variables, defined at the

master server, to control replication for an authority area. See

Master Server and Replication.

Appendix B: RWhois ABNF

This specification uses the Augmented Backus-Naur Form (ABNF)

notation, as defined in Section 2 of [RFC822].

General Definitions

Lexical Tokens

alpha = "a".."z" / "A".."Z"

digit = "0".."9"

hex-digit = digit / "a".."f" / "A".. "F"

id-char = alpha / digit / "_" / "-"

any-char = <ASCII 1..255,

except LF (linefeed) and CR (carriage return)>

dns-char = alpha / digit / "-"

email-char = <see [RFC822]>

space = " "

tab = <ASCII TAB (tab)>

lf = <ASCII LF (linefeed)>

cr = <ASCII CR (carriage return)>

crlf = cr lf

Grammar

year = 4digit

month = 2digit

day = 2digit

hour = 2digit

minute = 2digit

second = 2digit

milli-second = 3digit

host-name = dns-char *(dns-char / ".")

email = 1*email-char "@" host-name

authority-area = (dns-char / ".") *(dns-char / "." / "/")

object-id = 1*id-char "." authority-area

host-port = (host-name / ip-address) ":" 1*5digit

ip-address = 1*3digit "." 1*3digit "." 1*3digit "." 1*3digit

class-name = 1*id-char

attribute-name = 1*id-char

attribute-value = 1*any-char

time-stamp = year month day hour minute second milli-second

on-off = "on" / "off"

Note that the time-stamp must be in the Greenwich Mean Time (GMT)

time zone.

response = ok-response crlf / error-response crlf / info-response

ok-response = "%ok"

error-response = "%error" space error-code space error-text

error-code = 3digit

error-text = 1*any-char

info-response = "%info" space "on" crlf *(*any-char crlf) "%info"

space "off" crlf

rwhois-banner = "%rwhois" space version-list space host-name

[space implementation] crlf

version-list = version *("," version)

version = version-number [":" capability-id]

/ "V-1.5" ":" capability-id

version-number = "V-" 1*digit "." 1*digit

capability-id = response-id ":" extra-id

response-id = 6hex-digit

extra-id = 2hex-digit

implementation = 1*any-char

rwhois-protocol = client-sends / server-returns

client-sends = *(directives / rwhois-query)

server-returns = *(responses / rwhois-query-result)

directives = rwhois-dir / class-dir / directive-dir / display-dir /

holdconnect-dir / limit-dir / notify-dir / quit-dir /

status-dir / xfer-dir / x-dir

responses = rwhois-response / class-response/ directive-response/

display-response/ holdconnect-response/ limit-response/

notify-response/ quit-response/ register-response/

schema-response / security-response/ soa-response/

status-response/ xfer-response/ x-response

Required Directives

rwhois

rwhois-dir = "-rwhois" space version-number [space implementation]

crlf

rwhois-response = "%rwhois" space version space host-name

[space implementation] crlf

Optional Directives

class

class-dir = "-class" space authority-area *(space class-name) crlf

class-response = *class-record response

class-record = *class-line "%class" crlf

class-line = "%class" space class-name ":" "description" ":"

1*any-char crlf

/ "%class" space class-name ":" "version" ":" time-stamp crlf

/ "%class" space class-name ":" meta-field ":" meta-value crlf

meta-field = 1*id-char

meta-value = 1*any-char

directive

directive-dir = "-directive" *(space directive-name)crlf

directive-name = 1*id-char

directive-response = *directive-record response

directive-record = "%directive" space "directive" ":"

directive-name crlf *directive-line "%directive" crlf

directive-line = "%directive" space "description" ":" 1*any-char crlf

/ "%directive" space attribute-name ":" attribute-value crlf

display

display-dir = "-display" crlf

/ "-display" space display-name crlf

display-name = 1*id-char

display-response = *display-record response

display-record = "%display" space "name" ":" display-name crlf

*display-line "%display" crlf

display-line = "%display" space attribute-name ":" attribute-value

crlf

holdconnect

holdconnect-dir = "-holdconnect" space on-off crlf

holdconnect-response = response

limit

limit-dir = "-limit" space 1*digit crlf

limit-response = response

notify

notify-dir = "-notify" space "badref" space referral-query crlf

/ "-notify" space "recurref" space referral-query crlf

/ "-notify" space "update" space host-port ":" authority-area

crlf

/ "-notify" space "inssec" space host-port ":" authority-area

crlf

/ "-notify" space "delsec" space host-port ":" authority-area

crlf

referral-query = referral-url space [class-name space] query

notify-response = response

See the query section for the definitions of referral-url and query.

quit

quit-dir = "-quit" crlf

quit-response = response

/ register-on space "mod" space maintainer-id crlf

/ register-on space "del" space maintainer-id crlf

1*(register-line crlf)

maintainer-id = email

response

/ "%register" space "Updated" ":" time-stamp crlf response

/ response

schema

schema-dir = "-schema" space authority-area *(space class-name) crlf

schema-response = *schema-record response

schema-record = *schema-line "%schema" crlf

schema-line = "%schema" space class-name ":" attribute-name ":"

attribute-value crlf

security

security-dir = "-security" space "on" space direction space

security-method [space security-data] crlf security-payload

["-security" space "off" crlf]

direction = "request" / "response"

security-method = "password" / "pgp" / 1*id-char

security-data = password-data / pgp-data / 1*any-char

password-data = 1*any-char

pgp-data = "signed" / "encrypt" [space key-id] / "signed-encrypt"

[space key-id]

security-payload = *(*any-char crlf)

security-response = response

soa

soa-dir = "-soa" *(space authority-area) crlf

soa-response = *soa-record response

soa-record = *soa-line "%soa" crlf

soa-line = "%soa" space "authority" ":" authority-area crlf

/ "%soa" space "ttl" ":" 1*digit crlf

/ "%soa" space "serial" ":" time-stamp crlf

/ "%soa" space "refresh" ":" 1*digit crlf

/ "%soa" space "increment" ":" 1*digit crlf

/ "%soa" space "retry" ":" 1*digit crlf

/ "%soa" space "tech-contact" ":" email crlf

/ "%soa" space "admin-contact" ":" email crlf

/ "%soa" space "hostmaster" ":" email crlf

/ "%soa" space "primary" ":" host-port crlf

/ "%soa" space attribute-name ":" attribute-value crlf

status

status-dir = "-status" crlf

status-response = *status-line response

status-line = "%status" space "limit" ":" 1*digit crlf

/ "%status" space "holdconnect" ":" on-off crlf

/ "%status" space "forward" ":" on-off crlf

/ "%status" space "authority" ":" 1*digit crlf

/ "%status" space "display" ":" 1*any-char crlf

/ "%status" space "contact" ":" email crlf

/ "%status" space attribute-name ":" attribute-value crlf

xfer

xfer-dir = "-xfer" space authority-area *attribute-def

[space serial-number] crlf

attribute-def = [space "class=" class-name]

*(space "attribute=" attribute-name)

serial-number = time-stamp

xfer-response = *xfer-record response

xfer-record = *xfer-line "%xfer" crlf

xfer-line = "%xfer" space class-name ":" attribute-name ":"

attribute-value crlf

x-dir = "-X-" x-directive [space *[x-arguments]] crlf

x-directive = 1*id-char

x-arguments = *any-char

x-response = *(*any-char crlf) response

Query

rwhois-query = [class-name space] query crlf

query = query-string / attribute-query / query bin-boolean query

query-char = <any-char, except """, space, tab>

quoted-query-char = query-char / space / tab / "

query-string = 1*query-char ["*"] / """ 1*quoted-query-char ["*"] """

attribute-query = attribute-name "=" query-string

bin-boolean = "and" / "or"

rwhois-query-result = *(query-record / referral-record) response

query-record = 1*query-line crlf

query-line = class-name ":" attribute-name [";" type-char] ":"

attribute-value crlf

type-char = "T" / "I" / "S"

referral-record = 1*(referral-line crlf)

referral-line = "%referral" space referral-url

referral-url = "rwhois" ":" "//" host-port "/" "auth-area="

authority-area

Appendix C: Error Codes

When a server fails to run a command (directive or query), it returns

an error response. The ABNF for an error response is as follows.

error-response = "%error" space error-code space error-text

error-code = 3digit

error-text = 1*any-char

An error text may be modified, but its meaning must remain the same.

The server may append additional information to it, for example

"%error 333 Not master for authority area: foobar.com".

The following table describes the possible digits in the first,

second, and third positions of an error code.

XXX Description

1XX Information only, no action required

2XX Information, action required

3XX Specific command error, retry that command or try another one

4XX Serious for current command, may correct with another command

5XX Fatal, must disconnect

X0X System wide, no specific command

X1X System wide, no specific command

X2X Registration error

X3X Specific command

X4X Specific command

X5X Specific command

X6X Extended message (version specific)

XXX Sequential order

The following table gives an ordered list of RWhois error codes.

These codes may be extended with implementation- specific codes. An

implementation- specific code must have a "6" in the second position.

Code Text

120 Registration deferred

130 Object not authoritative

230 No objects found

300 Not compatible with version

320 Invalid attribute

321 Invalid attribute syntax

322 Required attribute missing

323 Object reference not found

324 Primary key not unique

325 Failed to update outdated object

330 Exceeded maximum objects limit

331 Invalid limit

332 Nothing to transfer

333 Not master for authority area

336 Object not found

338 Invalid directive syntax

340 Invalid authority area

341 Invalid class

342 Invalid host/port

350 Invalid query syntax

351 Query too complex

352 Invalid security method

353 Authentication failed

354 Encryption failed

400 Directive not available

401 Not authorized for directive

402 Unidentified error

420 Registration not authorized

436 Invalid display format

500 Memory allocation problem

501 Service not available

502 Unrecoverable error

503 Idle time exceeded

The following error codes, defined in [RFC1714], have been made

obsolete: 100, 200, 231, 334, 335, 337, 421, 431, 432, 433, 434,

460, 461, and 530.

Appendix D: Capability ID

The capability ID encodes which directives are implemented in the

server. To create a capability ID, perform a logical OR on all the

hexadecimal numbers corresponding to the implemented directives. The

resulting number is used in the banner, which is sent by the server

after opening a connection and as a response to the "-rwhois"

directive. The eight most significant bits of the capability ID are

reserved for future use:

class 000001h

directive 000002h

display 000004h

forward 000008h

holdconnect 000010h

limit 000020h

notify 000040h

quit 000080h

schema 000200h

security 000400h

soa 000800h

status 001000h

xfer 002000h

X 004000h

Appendix E: Schema Definitions

Attribute Definition Model

Name Type Description

Attribute N This is the name of the attribute.

Description S This is a free-form description of the attribute.

Type T This is a parameter that broadly indicates the use

of the attribute to the protocol. There are three

standard types: TEXT, ID, and SEE-ALSO. The default

is TEXT, which indicates that the value is a text

string. ID indicates that the attribute contains

the ID of another RWhois object. This type of

attribute is used for database normalization. SEE-

ALSO indicates that the attribute contains a pointer

(a Uniform Resource Identifier (URI)) to some other

kind of external data; for example, a World Wide Web

page or FTP site.

Format S This is an interpretable string that describes the

acceptance format of the value. The server (and

optionally the client) should match the value to the

format string to determine if the value is

acceptable. The format of this property is a

keyword indicating the syntax of the format string,

followed by a colon, followed by the format string

itself. Currently, the only keyword recognized is

"re" for POSIX.2 extended regular expressions.

Indexed B This is a true or false flag that indicates that

this attribute should be indexed (and therefore able

to be searched).

Required B This is a true or false flag that indicates that

this attribute must have a value.

Multi-Line B This is a true or false flag that indicates that

this attribute may have multiple instances in an

object; all the instances are to be considered as

multiple lines of the same attribute instance.

Repeatable B This is a true or false flag that indicates that

there may be multiple instances of this attribute in

a class and each instance is to be interpreted as a

separate instance (in contrast to Multi-Line). This

flag is mutually exclusive with Multi-Line: if

Multi-Line is true, then Repeatable must be false

and vice versa.

Primary B This is a true or false flag that indicates that

this attribute is a primary key. If more than one

attribute in a class is marked as primary, then

these attributes together form a single primary key.

The primary key is intended to be used to force

uniqueness among class instances. Therefore, there

can be only one instance of a primary key in a

database. The Primary flag implies that the

attribute is also required.

Hierarchical B This is a true or false flag that indicates that

this attribute is lexically hierarchical.

Private B This is a true or false flag that indicates whether

or not this attribute is private (that is, publicly

not viewable). It defaults to false. If it is true,

then only the clients that satisfy the

authentication/encryption requirements of a guardian

are able to view the attribute-value pair.

Type is defined as follows:

Type ABNF Definition

B "ON" / "OFF"

N 1*id-char

S 1*any-char

T "ID" / "SEE-ALSO" / "TEXT"

Base Class

Name Type Required RepeatableDescription

Class-Name TEXT Y N This attribute is the name of the

class to which the object

belongs.

Auth-Area TEXT Y N This attribute is the name of the

authority area to which the

object belongs.

ID TEXT Y N This attribute is the universal

identifier of the object.

Updated TEXT Y N This attribute is a time/date

stamp that indicates the time of

last modification of the object.

Guardian ID N Y This attribute is a link to a

guardian object. Its value is the

ID of a guardian object.

Private TEXT N N This attribute is a true or false

flag that indicates whether or

not an object is private (that

is, publicly not viewable). It

defaults to false. If it is

true, then only the clients

that satisfy the

authentication/encryption

requirements of one of the

object's guardians are able to

view the object. If the object

is publicly viewable, then the

Private attribute property of

each of its attributes still

applies.

TTL TEXT N N This attribute is the

"time-to-live" of a given object.

It is included only if an object

has a different time-to-live than

the default given in the Start of

Authority information. Its value

is specified in seconds.

Appendix F: Changes RWhois V1.0 - V1.5

General

* Multiple authority areas per server.

* Data replication.

* Revised schema model.

* Revised query routing rules.

* Revised error codes.

* Removed unnecessary spaces in responses and results.

Directives

* Class: New. Returns meta-information for a class.

* Display: Can return supported display formats.

* Load: Obsolete.

* Notify: Syntax change.

* Private: Obsolete.

* Register: Syntax change.

* Schema: Syntax change.

* Security: Obsoletes Private.

* Xfer: Syntax change.

Query

* Display option removed.

* Output format: Only the dump format is standard; optional type

character added.

* Attribute-restricted query.

* Revised referral syntax.