Internet Printing Protocol WG Robert Herriot INTERNET-DRAFT Tom Hastings Carl-Uno Manros Updates: RFC 2911 Xerox Corp. [Target Category: standards track] Henrik Holst Expires: January 17, 2002 i-data international a/s July 17, 2001 Internet Printing Protocol (IPP): The 'mailto' Delivery Method for Event Notifications Copyright (C) The Internet Society (2000). All Rights Reserved. Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of [RFC2026]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed as http://www.ietf.org/shadow.html. Abstract This document describes an extension to the Internet Printing Protocol/1.0 (IPP) [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910]. This document specifies the 'mailto' Delivery Method for use with the "IPP Event Notifications and Subscriptions" specification [ipp-ntfy]. When IPP Notification [ipp-ntfy] is supported, the Delivery Method defined in this document is one of the RECOMMENDED Delivery Methods for Printers to support. For this Delivery Method, when an Event occurs, the Printer immediately sends an Event Notification via an email message to the Notification Recipient specified in the Subscription Object. The message body of the email consists of Human Consumable text that is not intended to be parsed by a machine. The Notification Recipient receives the Event Notification in the same way as it receives any other email message. Herriot, et al. Expires: January 17, 2002 [page 1] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Table of Contents 1 Introduction.....................................................4 2 Terminology......................................................4 3 Model and Operation..............................................5 4 General Information..............................................6 5 Subscription Template Attributes.................................8 5.1 Additional Subscription Template Attributes....................8 5.1.1 notify-mailto-text-only (boolean)............................8 5.2 Additional Information about Subscription Template Attributes..9 5.2.1 notify-recipient-uri (uri)...................................9 5.2.2 notify-user-data (octetString(63))..........................10 6 Event Notification Content......................................10 6.1 Headers.......................................................11 6.1.1 'Date' header...............................................11 6.1.2 'From' header...............................................11 6.1.3 'Subject' header............................................12 6.1.4 'Sender' header.............................................12 6.1.5 'Reply-to' header...........................................13 6.1.6 'To' header.................................................13 6.1.7 'Content-type' header.......................................13 6.2 Message Body..................................................14 6.3 Plain Text Content............................................14 6.3.1 Event Notification Content Common to All Events.............15 6.3.2 Additional Event Notification Content for Job Events........17 6.3.3 Additional Event Notification Content for Printer Events....18 6.4 Examples......................................................18 6.4.1 Job Event Example...........................................19 6.4.2 Printer Event Example.......................................20 6.4.3 Printer Event Example (localized to Danish)................21 7 Conformance Requirements........................................23 8 IANA Considerations.............................................23 8.1 Attribute Registration........................................23 8.2 Additional uriScheme Attribute Value Registration for the "operations-supported" Printer Attribute..........................24 9 Internationalization Considerations.............................24 10 Security Considerations........................................24 11 References.....................................................25 Herriot, et al. Expires: January 17, 2002 [page 2] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 12 Author's Addresses.............................................27 13 Summary of Base IPP Documents..................................28 14 Full Copyright Statement.......................................29 Table of Tables Table 1 - Information about the Delivery Method.....................6 Table 2 - Additional Subscription Template Attributes...............8 Table 3 - Printer Name in Event Notification Content...............16 Table 4 - Event Name in Event Notification Content.................17 Table 5 - Job Name in Event Notification Content...................17 Table 6 - Job State in Event Notification Content..................18 Table 7 - Printer State in Event Notification Content..............18 Herriot, et al. Expires: January 17, 2002 [page 3] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 1 Introduction The "IPP Event Notifications and Subscriptions" document [ipp-ntfy] defines an OPTIONAL extension to Internet Printing Protocol/1.0 (IPP) [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910] (for a description of the base IPP documents, see section 13). That extension defines operations that a client can perform in order to create Subscription Objects in a Printer and carry out other operations on them. A Subscription Object represents a Subscription abstraction. A client associates Subscription Objects with a particular Job by performing the Create-Job-Subscriptions operation or by submitting a Job with subscription information. A client associates Subscription Objects with the Printer by performing a Create-Printer-Subscriptions operation. Four other operations are defined for Subscription Objects: Get-Subscriptions-Attributes, Get-Subscriptions, Renew- Subscription, and Cancel-Subscription. The Subscription Object specifies that when one of the specified Events occurs, the Printer sends an asynchronous Event Notification to the specified Notification Recipient via the specified Delivery Method (i.e., protocol). The "IPP Event Notifications and Subscriptions" document [ipp-ntfy] specifies that each Delivery Method is defined in another document. This document is one such document, and it specifies the 'mailto' delivery method. When IPP Notification [ipp-ntfy] is supported, the Delivery Method defined in this document is one of the RECOMMENDED Delivery Methods and Printers to support. For this Delivery Method, when an Event occurs, the Printer immediately sends an Event Notification via an email message to the Notification Recipient specified in the Subscription Object. The message body of the email consists of Human Consumable text that is not intended to be parsed by a machine. The 'mailto' Delivery Method is a 'push' Delivery Method as defined in [ipp-ntfy]. The Notification Recipient receives the Event Notification in the same way as it receives any other email message. 2 Terminology This section defines the following terms that are used throughout this document: This document uses the same terminology as [RFC2911], such as "client", "Printer", "attribute", "attribute value", "keyword", "operation", "request", "response", and "support". Herriot, et al. Expires: January 17, 2002 [page 4] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to conformance as defined in RFC 2119 [RFC2119] and [RFC2911] section 12.1. If an implementation supports the extension defined in this document, then these terms apply; otherwise, they do not. These terms define conformance to this document only; they do not affect conformance to other documents, unless explicitly stated otherwise. Capitalized terms, such as Notification Recipient, Event Notification, Compound Event Notification, Printer, etc., are defined in [ipp-ntfy], have the same meanings, and are not reproduced here. 3 Model and Operation In a Subscription Creation Operation, when the value of the "notify- recipient-uri" attribute contains the URI scheme "mailto", the client is requesting that the Printer use the 'mailto' Delivery Method for Event Notifications generated from the new Subscription Object. For this Delivery Method, the "notify-recipient-uri" attribute value MUST consist of a "mailto" scheme followed by a colon, and then followed by an address part (e.g., 'mailto:smith@abc.com'). See section 5.2.1 for the syntax of the "notify-recipient-uri" attribute value for this Delivery Method. A Printer MUST support SMTP [RFC821], and it MAY support other email protocols. A Printer MAY use additional services, such as SMTP delivery status notification [RFC1891] or S/MIME encryption [RFC2633]. If the client wants the Printer to send Event Notifications via the 'mailto' Delivery Method, the client MUST choose a value for "notify- recipient-uri" attribute which conforms to the rules of section 5.2.1. To avoid denial-of-service attacks, a client SHOULD NOT use distribution lists as the Notification Recipient. When an Event occurs, the Printer MUST immediately: 1.Find all pertinent Subscription Objects P according to the rules of section 9 of [ipp-ntfy], AND 2.Find the subset M of these Subscription Objects P whose "notify- recipient-uri" attribute has a scheme value of 'mailto', AND 3.For each Subscription Object in M, the Printer MUST Herriot, et al. Expires: January 17, 2002 [page 5] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 a)generate an email message as specified in section 5.2.2 AND b)send the email message to the Notification Recipient specified by the address part of the "notify-recipient-uri" attribute value (see section 5.2.1). If the Printer supports only SMTP, it MUST send the email message via SMTP. If the Printer supports additional email protocols, it MUST determine the protocol from the address part of the "notify- recipient-uri" attribute value and then send the email message via the appropriate email protocol. When a Subscribing Client is subscribing to the 'job-progress' event (which is a frequently occurring event), it SHOULD supply the "notify-time-interval" attribute (see [ipp-ntfy]) in the Subscription Creation request with a suitable value to limit the time between 'job-progress' Event Notifications sent by the Printer. 4 General Information If a Printer supports this Delivery Method, the following are its characteristics. Table 1 - Information about the Delivery Method Document Method Conformance Delivery Method Realization Requirement 1. What is the URL scheme name for the mailto Delivery Method? 2. Is the Delivery Method REQUIRED, RECOMMENDED RECOMMENDED, or OPTIONAL for an IPP Printer to support? 3. What transport and delivery A Printer MUST support protocols does the Printer use to SMTP. It MAY support other deliver the Event Notification email protocols. Content, i.e., what is the entire network stack? 4. Can several Event Notifications be A Printer implementation combined into a Compound Event MAY combine several Event Notification? Notifications into a single email message (see section 6). Herriot, et al. Expires: January 17, 2002 [page 6] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 email message (see section 6). 5. Is the Delivery Method initiated by This Delivery Method is a the Notification Recipient (pull), push. or by the Printer (push)? 6. Is the Event Notification content Human Consumable Machine Consumable or Human Consumable? 7. What section in this document Section 6 answers the following question? For a Machine Consumable Event Notification, what is the representation and encoding of values defined in section 9.1 of [ipp-ntfy] and the conformance requirements thereof? For a Human Consumable Event Notification, what is the representation and encoding of pieces of information defined in section 9.2 of [ipp-ntfy] and the conformance requirements thereof? 8. What are the latency and reliability Same as the underlying SMTP of the transport and delivery (or other optional) email protocol? transport 9. What are the security aspects of the Same as the underlying SMTP transport and delivery protocol, (or other optional) email e.g., how it is handled in transport firewalls? 10. What are the content length None restrictions? 11. What are the additional values or None pieces of information that a Printer sends in an Event Notification content and the conformance requirements thereof? 12. What are the additional See section 5.1.1 on Subscription Template and/or "notify-mailto-text-only" Subscription Description attributes and the conformance requirements thereof? Herriot, et al. Expires: January 17, 2002 [page 7] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 and the conformance requirements thereof? 13. What are the additional Printer None Description attributes and the conformance requirements thereof? 5 Subscription Template Attributes 5.1 Additional Subscription Template Attributes This Delivery Method introduces one additional Subscription Template Attribute (See Table 2). Table 2 - Additional Subscription Template Attributes Attribute in Subscription Object Default and Supported Printer Attributes notify-mailto-text-only (boolean) N/A 5.1.1 notify-mailto-text-only (boolean) When the Printer generates an Event Notification from a Subscription Object, this attribute specifies whether the Printer generates the Event Notification with only plain text (i.e. 'text/plain') or with Content-Types that the Printer chooses. The Printer MUST support this attribute if it supports the 'mailto' Delivery Method. A client MAY supply this attribute. If a client does not supply this attribute, the Printer MUST populate this attribute with the value of 'false' on the Subscription Object. There is no "notify-mailto-text- only-default" attribute. If the value of this attribute is 'true' in a Subscription Object, the message body of each Event Notification that the Printer generates from the Subscription Object MUST contain plain text only (i.e. 'text/plain' with the charset specified by the "notify-charset' Subscription Object attribute). Herriot, et al. Expires: January 17, 2002 [page 8] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 If the value of this attribute is 'false' in a Subscription Object, the Content-Type of the message body of each Event Notification that the Printer generates from the Subscription Object MUST be either 'text/plain' or 'multipart', depending on implementation. If the Content-Type is 'multipart', one message body of the 'multipart' MUST be the same as the 'text/plain' message body when this attribute has the value of 'true'. Each of the other message bodies of the 'multipart' MAY be any Content-Type (e.g. 'text/html', 'image/gif', 'audio/basic', etc.). A Printer MUST support both values ('true' and 'false') of this attribute. There is no "notify-mailto-text-only-supported" attribute. 5.2 Additional Information about Subscription Template Attributes This section describes additional values for attributes defined in [ipp-ntfy]. 5.2.1 notify-recipient-uri (uri) This section describes the syntax of the value of this attribute for the 'mailto' Delivery Method. The syntax for values of this attribute for other Delivery Method is defined in other Delivery Method Documents. In order to support the 'mailto' Delivery Method, the Printer MUST support the following syntax for the 'mailto' Delivery Method when the Printer uses SMTP. The line below use RFC 822 syntax rules and terms. "mailto:" mailbox Note: the above syntax allows 1 occurrence of 'mailbox'. The occurrence of 'mailbox' represents an email address of a Notification Recipient. For SMTP, the phrase 'address part' of the "notify-recipient-uri" attribute value refers to the 'mailbox' part of the value. Example: mailto:jones@acme.com Unlike other URLs, the mailto scheme MUST NOT use // after the colon (see [RFC2368]). The Printer MAY support other syntax for the 'address part' if it supports email protocols in addition to SMTP. Herriot, et al. Expires: January 17, 2002 [page 9] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 As noted in [ipp-ntfy], the uriScheme value of the corresponding "notify-schemes-supported" Printer attribute does not include the ":" character. 5.2.2 notify-user-data (octetString(63)) This attributes has a special use for the 'mailto' Delivery Method. It specifies the email address of the Subscribing Client. It is primarily useful when the Notification Recipient is some person other than the Subscribing Client. Then the Notification Recipient has a way to reply to the Subscribing Client. If a client specifies this Delivery Method in a Subscription Creation Operation, and the specified Notification Recipient is not associated with the same person as the client, the client SHOULD supply its email address as the value of the "notify-user-data" attribute. If the client does not supply this attribute, the Printer MUST NOT populate the Subscription Object with this attribute. 6 Event Notification Content This section describes the content of an Event Notification sent via the 'mailto' Delivery Method using the SMTP protocol. This document does not describe the content for other email protocols, but an implementation should use this section as a model. When a Printer sends an email message via SMTP, the content MUST conform to RFC 822. The following sections define the content that a Printer MUST send. A Printer MAY send additional content as long as the resulting content conforms to RFC 822. While the "Event Notification Ordering" in [ipp-ntfy] section 9 specifies ordering requirements for Printers when sending separate Event Notifications, email messages are not guaranteed to arrive in the order sent so that the Notification Recipient may not receive them in the same order. Each subsection below specifies the syntax that pertains to the subsection. The syntax rules and syntactic terms (e.g. 'date-time') in each subsection come from RFC 822, except for the section on "Content-Type" which comes from RFC 1521. The Event Notification content has two parts, the headers and the message body. The headers precede the message body and are separated by a blank line (see [RFC 822]). Herriot, et al. Expires: January 17, 2002 [page 10] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 A Printer implementation MAY combine several Event Notifications into a single email message body. Such an email message is considered a single Compound Event Notification and MUST follow the "Event Notification Ordering" requirements for Event Notifications within a Compound Event Notification specified in [ipp-ntfy] section 9. 6.1 Headers When a Printer sends an Event Notification via SMTP, it MUST include the following headers. RFC 822 RECOMMENDS that the headers be in the order that they appear below. 6.1.1 'Date' header Syntax: "Date" ":" date-time This header contains the date and time that the Event occurred. The Printer MUST include a "Date" header if and only if it supports the "printer-current-time" Printer attribute. 6.1.2 'From' header Syntax: "From" ":" mailbox where mailbox = addr-spec / phrase route-addr This header causes a typical email reader to show the email as coming from the Printer that is sending the Event Notification. The Printer MUST include a "From" header whose syntax is specified above. The Printer MUST use the second alternative of the syntax for 'mailbox' defined above (i.e. 'phrase route-addr'). The 'phrase' is the Printer's display name and it MUST be the value of the "printer- name" Printer attribute. The 'route-addr' MUST contain an email address (inside angle brackets) belonging to either an administrator or the output-device. This email address NEED NOT be capable of receiving mail. There is no Printer attribute to hold this email address, so that it cannot be configured using the IPP protocol without an implementation-defined attribute extension. Herriot, et al. Expires: January 17, 2002 [page 11] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 6.1.3 'Subject' header Syntax: "Subject" ":" *text This header specifies the subject of the message and contains a short summary of the Event Notification. The Printer MUST include a "Subject" header whose syntax is specified above. The Printer MUST localize the '*text' using the values of the "notify-charset" and "notify-natural-language" Subscription Object attributes. For Printer Events, the '*text' SHOULD start with the localized word "printer:", followed by the Printer name, and then followed by the localized Event name, e.g., in English: "printer: 'tiger' stopped" or in Danish: "Printeren 'tiger' er standset". For Job Events, the '*text' SHOULD start with the localized phrase "print job:", followed by the Job name, and then followed by the localized Event name, e.g., in English: "print job: 'financials' completed". The wording is implementation dependent. A Notification Recipient MUST NOT expect to be able to parse this text. But an email filter might look for "printer" or "print job". 6.1.4 'Sender' header Syntax: "Sender" ":" mailbox This header causes a typical email reader to show the email as coming on behalf of the person associated with the Subscribing Client. If the Subscription Object contains the "notify-user-data" attribute, and if its value satisfies the RFC 822 syntax rules for 'mailbox', the Printer MUST include a "Sender" header whose syntax is specified above. Otherwise, the Printer MUST NOT include a "Sender" header. For the "Sender" header, the 'mailbox' MUST be the value of the "notify-user-data" Subscription Object attribute. See section 5.2.2 for details about the "notify-user-data" attribute. Herriot, et al. Expires: January 17, 2002 [page 12] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 6.1.5 'Reply-to' header Syntax: "Reply-to" ":" mailbox If the Notification Recipient replies to Event Notification email, this header causes a typical email reader to send email to the person acting as the Subscribing Client. The rules are identical to the "Sender" header. If the Subscription Object contains the "notify-user-data" attribute, and if its value satisfies the RFC 822 syntax rules for "mailbox", the Printer MUST include a "Reply-to" header whose syntax is specified above. Otherwise, the Printer MUST NOT include a "Reply-to" header. For the "Reply-to" header, the "mailbox" MUST be the value of the "notify-user-data" Subscription Object attribute. See section 5.2.2 for details about the "notify-user-data" attribute. 6.1.6 'To' header Syntax: "To" ":" 1#mailbox See [RFC 1521] for the syntax. This header specifies the Notification Recipient(s). The Printer MUST include a "To" header whose syntax is specified above. The '1#mailbox' MUST be the '1#mailbox' part of the value of the "notify-recipient-uri" Subscription attribute, i.e. the part after the "mailto:". 6.1.7 'Content-type' header Syntax: "Content-Type" ":" type "/" subtype *(";"parameter) See [RFC 1521] for the syntactic terms (e.g. 'type'). This header specifies the format of the message body. The Printer MUST include the "Content-Type" header. Herriot, et al. Expires: January 17, 2002 [page 13] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 The "notify-mailto-text-only" attribute determines the 'type' and 'subtype' values. The possible values are "text/plain" and "multipart" values. 6.2 Message Body The message body MUST contain Human Consumable content as plain text. It MAY also contain other types of implementation dependent content. For plain text, the Content-Type of Human Consumable content MUST be 'text/plain'. For implementation dependent content, the Content-Type of Human Consumable content MUST be 'multipart'. The Content-Type of one body part MUST be 'text/plain' and the Content-Types of the other body parts are implementation dependent. See section 6.3 for a description of plain text content. The following table shows the Content-Type of the message body for the "notify-mailto-text-only" attribute: "notify- Content-Type of Message Body mailto-text- Message Body only" attribute false 'text/plain' Human Consumable true 'text/plain' or* Human Consumable plain text 'multipart' Human Consumable where one body part is plain text * The Content-Type depends on the implementation. A Printer MAY send 'text/plain' only or it MAY send several body parts of various Content-Types within a message body whose Content-Type is 'multipart'. 6.3 Plain Text Content When a Printer sends a plain text message, it MUST localize the text using the values of the "notify-charset" and "notify-natural- language" Subscription Object attributes. Herriot, et al. Expires: January 17, 2002 [page 14] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Section 9.2 in [ipp-ntfy] specifies the information that a Delivery Method MUST specify and a Printer SHOULD send. A Printer SHOULD send the following localized information in the message body. The specific wording of this information and its layout are implementation dependent. a)the Printer name (see Table 3) b)omitted (see below). c)for Printer Events only: i) the Event (see Table 4) and/or Printer state information (see Table 7) d)for Job Events only: i) the job identity (see Table 5) ii) the Event (see Table 4) and/or Job state information (see Table 6) Item b) in the above list is omitted because the Printer sends the time of the Event as an email header (see section 6.1.1 on the 'Date' header). The subsections of this section specify the attributes that a Printer MUST use to obtain this information. The Printer MAY send additional information, depending on implementation. Notification Recipients MUST NOT expect to be able to parse the message. The next three sections define the attributes in Event Notification Contents that are: a)for all Events b)for Job Events only c)for Printer Events only 6.3.1 Event Notification Content Common to All Events The Printer MUST send the following information. There is a separate table for each piece of information. Each row in the table represents a source value for the information and the values are listed in order of preference, with the first one being the preferred one. An implementation SHOULD use the source value from Herriot, et al. Expires: January 17, 2002 [page 15] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 the earliest row in each table. It MAY use the source value from another row instead, or it MAY combine the source values from several rows. An implementation is free to determine the best way to present this information. The tables in this section and following sections contain the following columns for each piece of information: a)Source of Value: the name of the attribute that supplies the value for the Event Notification b)Sends: MAY: this is the only value used in the tables. It means that the Printer OPTIONALLY sends this value. However, the Printer SHOULD use at least one value from each table. c)Source Object: the object from which the source value comes. Table 3 lists the source of the information for the Printer Name. The "printer-name" is more user-friendly unless the Notification Recipient is in a place where the Printer name is not meaningful. For example, an implementation could have the intelligence to send the value of the "printer-name" attribute to a Notification Recipient that can access the Printer via value of the "printer-name" attribute and otherwise send the value of the "notify-printer-uri" attribute. Table 3 - Printer Name in Event Notification Content Source Value Sends Source Object printer-name (name(127)) MAY Printer notify-printer-uri (uri) MAY Subscription Table 4 lists the source of the information for the Event name. A Printer MAY combine this information with state information described for Jobs in Table 6 or for Printers in Table 7. Herriot, et al. Expires: January 17, 2002 [page 16] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Table 4 - Event Name in Event Notification Content Source Value Sends Source Object notify-subscribed-event (type2 keyword) MAY Subscription 6.3.2 Additional Event Notification Content for Job Events This section lists the source of the additional information that a Printer MUST send for Job Events. Table 5 lists the source of the information for the job name. The "job-name" is likely more meaningful to a user than "job-id". Table 5 - Job Name in Event Notification Content Source Value Sends Source Object job-name (name(MAX)) MAY Job job-id (integer(1:MAX)) MAY Job Table 6 lists the source of the information for the job-state. If a Printer supports the "job-state-message" and "job-detailed-state- message" attributes, it SHOULD use those attributes for the job state information, otherwise, it should fabricate such information from the "job-state" and "job-state-reasons". For some Events, a Printer MAY combine this information with Event information. Herriot, et al. Expires: January 17, 2002 [page 17] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Table 6 - Job State in Event Notification Content Source Value Sends Source Object job-state-message (text(MAX)) MAY Job job-detailed-status-messages (1setOf Job text(MAX)) MAY job-state (type1 enum) MAY Job job-state-reasons (1setOf type2 keyword) MAY Job 6.3.3 Additional Event Notification Content for Printer Events This section lists the source of the additional information that a Printer MUST send for Printer Events. Table 7 lists the source of the information for the printer-state. If a Printer supports the "printer-state-message", it SHOULD use that attribute for the job state information, otherwise it SHOULD fabricate such information from the "printer-state" and "printer- state-reasons". For some Events, a Printer MAY combine this information with Event information. Table 7 - Printer State in Event Notification Content Source Value Sends Source Object printer-state-message (text(MAX)) MAY Printer printer-state (type1 enum) MAY Printer printer-state-reasons (1setOf type2 MAY Printer keyword) printer-is-accepting-jobs (boolean) MAY Printer 6.4 Examples This section contains three examples. One is a Job Event and the other two are Printer Events, the latter in Danish. Herriot, et al. Expires: January 17, 2002 [page 18] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 A Printer implementation NEED NOT generate Event Notification content that is identical or even similar to these examples. In fact it would be unfortunate if every implementation copied these example as is. These examples merely show some possibilities and are not necessarily the best way to convey information about an Event. 6.4.1 Job Event Example This section contains an example of an Event Notification of a Job Event. A Subscribing Client Mike Jones (who works for xyz Corp.) performs a Subscription Creation Operation as part of the Print-Job operation on Printer "ipp://tiger@abc.com". Mike Jones specifies that the "job- name" is "financials". Mike is printing the Job for Bill Smith at abc Corp. The Subscription Object then has the following attributes: Attribute Name Attribute Value notify-recipient-uri mailto:bsmith@abc.com notify-events job-completed notify-user-data mjones@xyz.com notify-mailto-text-only true notify-charset us-ascii notify-natural-language en-us notify-subscription-id 35692 notify-sequence-number 0 notify-printer-up-time 34593 notify-printer-uri ipp://tiger@abc.com notify-job-id 345 notify-subscriber-user-name mjones Herriot, et al. Expires: January 17, 2002 [page 19] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 When the Job completes, the Printer generates and sends the following email message: Date: 17 Jul 00 1632 PDT From: tiger Subject: print job: 'financials' completed Sender: mjones@xyz.com Reply-to: mjones@xyz.com To: bsmith@abc.com Content-type: text/plain printer: tiger job: financials job-state: completed The reader should note that the phrases are not identical to IPP keywords. They have been localized to English. 6.4.2 Printer Event Example This section contains an example of an Event Notification of a Printer Event. A Subscribing Client Peter Williams, a Printer admin, performs a Create-Printer-Subscriptions operation on Printer "ipp://tiger@abc.com". The Subscription Object then has the following attributes: Herriot, et al. Expires: January 17, 2002 [page 20] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Attribute Name Attribute Value notify-recipient-uri mailto:pwilliams@abc.com notify-events printer-state-changed notify-mailto-text-only true notify-charset us-ascii notify-natural-language en-us notify-subscription-id 4623 notify-sequence-number 0 notify-printer-uptime 23002 notify-printer-uri ipp://tiger@abc.com notify-lease-expiration-time 0 notify-subscriber-user-name pwilliams When the Printer jams, the Printer generates and sends the following email message: Date: 29 Aug 00 0832 PDT From: tiger Subject: printer: 'tiger' has stopped To: pwilliams@abc.com Content-type: text/plain Printer tiger has stopped with a paper jam. The reader should note that the phrases are not identical to IPP keywords. They have been localized to English. 6.4.3 Printer Event Example (localized to Danish) This section contains an example of an Event Notification of a Printer Event localized to Danish. Herriot, et al. Expires: January 17, 2002 [page 21] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 A Subscribing Client Per Jensen, a Printer admin, performs a Create- Printer-Subscriptions operation on Printer "ipp://tiger@def.dk". The Subscription Object then has the following attributes: Attribute Name Attribute Value notify-recipient-uri mailto:pjensen@def.dk notify-events printer-state-changed notify-mailto-text-only true notify-charset utf-8 notify-natural-language da notify-subscription-id 50225 notify-sequence-number 0 notify-printer-uptime 53217 notify-printer-uri ipp://tiger@def.dk notify-lease-expiration-time 0 notify-subscriber-user-name pjensen When the Printer jams, the Printer generates and sends the following email message: Date: 29 Jan 00 0832 CET From: tiger Subject: Printeren 'tiger' er standset To: pjensen@def.dk Content-type: text/plain;charset=utf-8 Printerens navn er 'tiger'. Printeren er standset. Aarsagen er papir stop. Herriot, et al. Expires: January 17, 2002 [page 22] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 7 Conformance Requirements The 'mailto' Delivery Method is RECOMMENDED for a Printer to support. If the Printer supports the 'mailto' Delivery Method, the Printer MUST: 1.meet the conformance requirements defined in [ipp-ntfy]. 2.support the "notify-mailto-text-only" Subscription Object attribute defined in section 5.1.1. 3.support the syntax for the "notify-recipient-uri" Subscription Object attribute defined in section 5.2.1 4.support the use for the "notify-user-data" Subscription Object attribute defined in section 5.2.2 5.support SMTP for sending Event Notifications. 6.support the 'text/plain' Content-Type for the message body. 7.support sending Event Notification via email with the content specified in section 5.2. 8 IANA Considerations Because the 'mailto' URL scheme is already defined in a standards track document [RFC 2368] and has been registered with IANA as a URL scheme, this document does not require that the mailto URL scheme be further registered as a protocol scheme. The rest of this section contains the exact registration information for IANA to add to the various IPP Registries according to the procedures defined in RFC 2911 [RFC2911] section 6 to cover the definitions in this document. Note to RFC Editors: Replace RFC NNNN below with the RFC number for this document, so that it accurately reflects the content of the information for the IANA Registry. 8.1 Attribute Registration The following table lists the attribute defined in this document. This is to be registered according to the procedures in RFC 2911 [RFC2911] section 6.2. Herriot, et al. Expires: January 17, 2002 [page 23] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 Subscription Template attributes: Ref. Section: notify-mailto-text-only (boolean) RFC NNNN 5.1.1 The resulting attribute registration will be published in the ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attributes/ area. 8.2 Additional uriScheme Attribute Value Registration for the "operations-supported" Printer Attribute The following table lists the uriScheme value defined in this document as an additional uriScheme value for use with the "notify- schemes-supported" Printer attribute defined in [ipp-ntfy]. This is to be registered according to the procedures in RFC 2911 [RFC2911] section 6.1. uriScheme Attribute Values: Ref. Section: mailto RFC NNNN 5.2.1 The resulting uri scheme attribute value registration will be published in the ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute- values/notify-schemes-supported/ area. 9 Internationalization Considerations This Delivery Method presents no internationalization considerations beyond those covered in the [ipp-ntfy] document, and sections 6.1.3 and 6.2 of this document. The Notification Recipient is expected to present the email as received because the Printer does all necessary localization to the Event Notification contents. 10 Security Considerations The biggest security concern is that a Subscribing Client will cause unsolicited Event Notifications to be sent to third parties, potentially creating denial-of-service problems (i.e., spam). The problem is even worse if the third parties are distribution lists. Herriot, et al. Expires: January 17, 2002 [page 24] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 There exist scenarios where third party notification is required (see Scenario #2 and #3 in [ipp-not-req]). The fully secure solution would require active agreement of all persons before they can become Notification Recipients. However, requirement #9 in [ipp-req] ("There is no requirement for IPP Printer receiving the print request to validate the identity of an event recipient") argues against this. To minimize the risk, a Printer could disallow third party Notification Recipients (a traditional facsimile model). The Delivery Method recommends that the Subscribing Client supply his or her email address as the value of the "notify-user-data" attribute in the Subscription Creation Operation when the Notification Recipient is a third party. To reduce the chance of spamming or identify the spammer, a Printer could disallow third party Notification Recipients if the Subscribing Client doesn't supply the "notify-user-data" attribute with a valid email address. Some firewall administrators prevent mail attachments from being accepted into their organizations because of the problem of the attachments containing computer viruses. The 'mailto' Delivery Method allows the Subscribing Client to request that the Content-Type of a message body be 'text/plain'. 11 References [ipp-iig] Hastings, T., Manros, C., Kugler, K, Holst H., Zehler, P., "Internet Printing Protocol/1.1: draft-ietf-ipp-implementers- guide-v11-03.txt, work in progress, July 17, 2001. [ipp-ntfy] Herriot, R., Hastings, T., Isaacson, S., Martin, J., deBry, R., Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP Event Notifications and Subscriptions", , July 17, 2001. [RFC821] Jonathan B. Postel, "Simple Mail Transfer Protocol", RFC 821, August, 1982. [RFC822] David H. Crocker, "Standard For The Format Of ARPA Internet Text Messages", RFC 822, August 13, 1982. Herriot, et al. Expires: January 17, 2002 [page 25] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 [RFC1341] N. Borenstein, N. Freed, "MIME (Multipurpose Internet Mail Extensions): Mechanisms for Specifying and Describing the Format of Internet Message Bodies", RFC 1341, June, 1992. [RFC1521] N. Borenstein, N. Freed, "MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies", RFC 1521, September 1993. [RFC1891] K. Moore, "SMTP Service Extension for Delivery Status Notifications", RFC 1891, January 1996 [RFC2026] S. Bradner, "The Internet Standards Process -- Revision 3", RFC 2026, October 1996. [RFC2046] R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1", RFC 2616, June 1999. [RFC2368] P. Hoffman, L. Masinter, J. Zawinski, "The mailto URL scheme", RFC 2368, July 1998. [RFC2616] R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1", RFC 2616, June 1999. [RFC2633] B. Ramsdell, "S/MIME Version 3 Message Specification", RFC 2633, June 1999. [RFC2910] Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing Protocol/1.1: Encoding and Transport", RFC 2910, September, 2000. [RFC2911] R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell, "Internet Printing Protocol/1.0: Model and Semantics", RFC 2911, September, 2000. Herriot, et al. Expires: January 17, 2002 [page 26] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 12 Author's Addresses Robert Herriot Xerox Corporation 3400 Hillview Ave., Bldg #1 Palo Alto, CA 94304 Phone: 650-813-7696 Fax: 650-813-6860 Email: robert.herriot@pahv.xerox.com Henrik Holst i-data international a/s Vadstrupvej 35-43 2880 Bagsvaerd, Denmark Phone: +45 4436-6000 Fax: +45 4436-6111 e-mail: hh@i-data.com Tom Hastings Xerox Corporation 737 Hawaii St. ESAE 231 El Segundo, CA 90245 Phone: 310-333-6413 Fax: 310-333-5514 e-mail: hastings@cp10.es.xerox.com Carl-Uno Manros Xerox Corporation 737 Hawaii St. ESAE 231 El Segundo, CA 90245 Phone: 310-333-8273 Fax: 310-333-5514 e-mail: manros@cp10.es.xerox.com IPP Web Page: http://www.pwg.org/ipp/ IPP Mailing List: ipp@pwg.org To subscribe to the ipp mailing list, send the following email: 1) send it to majordomo@pwg.org 2) leave the subject line blank Herriot, et al. Expires: January 17, 2002 [page 27] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 3) put the following two lines in the message body: subscribe ipp end Implementers of this specification document are encouraged to join IPP Mailing List in order to participate in any discussions of clarification issues and review of registration proposals for additional attributes and values. In order to reduce spam the mailing list rejects mail from non-subscribers, so you must subscribe to the mailing list in order to send a question or comment to the mailing list. 13 Summary of Base IPP Documents The base set of IPP documents includes: Design Goals for an Internet Printing Protocol [RFC2567] Rationale for the Structure and Model and Protocol for the Internet Printing Protocol [RFC2568] Internet Printing Protocol/1.1: Model and Semantics [RFC2911] Internet Printing Protocol/1.1: Encoding and Transport [RFC2910] Internet Printing Protocol/1.1: Implementer's Guide [ipp-iig] Mapping between LPD and IPP Protocols [RFC2569] Internet Printing Protocol (IPP): IPP Event Notifications and Subscriptions [ipp-ntfy] The "Design Goals for an Internet Printing Protocol" document takes a broad look at distributed printing functionality, and it enumerates real-life scenarios that help to clarify the features that need to be included in a printing protocol for the Internet. It identifies requirements for three types of users: end users, operators, and administrators. It calls out a subset of end user requirements that are satisfied in IPP/1.0. A few OPTIONAL operator operations have been added to IPP/1.1. The "Rationale for the Structure and Model and Protocol for the Internet Printing Protocol" document describes IPP from a high level view, defines a roadmap for the various documents that form the suite of IPP specification documents, and gives background and rationale for the IETF working group's major decisions. The "Internet Printing Protocol/1.1: Model and Semantics" document describes a simplified model with abstract objects, their attributes, and their operations that are independent of encoding and transport. It introduces a Printer and a Job object. The Job object optionally supports multiple documents per Job. It also addresses security, internationalization, and directory issues. Herriot, et al. Expires: January 17, 2002 [page 28] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 The "Internet Printing Protocol/1.1: Encoding and Transport" document is a formal mapping of the abstract operations and attributes defined in the model document onto HTTP/1.1 [RFC2616]. It defines the encoding rules for a new Internet MIME media type called "application/ipp". This document also defines the rules for transporting over HTTP a message body whose Content-Type is "application/ipp". This document defines the 'ippget' scheme for identifying IPP printers and jobs. The "Internet Printing Protocol/1.1: Implementer's Guide" document gives insight and advice to implementers of IPP clients and IPP objects. It is intended to help them understand IPP/1.1 and some of the considerations that may assist them in the design of their client and/or IPP object implementations. For example, a typical order of processing requests is given, including error checking. Motivation for some of the specification decisions is also included. The "Mapping between LPD and IPP Protocols" document gives some advice to implementers of gateways between IPP and LPD (Line Printer Daemon) implementations. The "IPP Event Notifications and Subscriptions" document defines an extension to IPP/1.0 [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910]. This extension allows a client to subscribe to printing related Events and defines the semantics for delivering asynchronous Event Notifications to the specified Notification Recipient via a specified Delivery Method (i.e., protocols) defined in (separate) Delivery Method documents. 14 Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. Herriot, et al. Expires: January 17, 2002 [page 29] INTERNET-DRAFT IPP: The 'mailto' Delivery Method July 17, 2001 The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Herriot, et al. Expires: January 17, 2002 [page 30]