INTERNET-DRAFT
Robert Herriot (editor)
Sun Microsystems, Inc.
Tom Hastings
Xerox Corporation
Norm Jacobs
Sun Microsystems, Inc.
Jay Martin
Underscore, Inc.
July 30, 1997
Mapping between LPD and IPP Protocols
<draft-ietf-ipp-lpd-ipp-map-01.txt>
Expires Jan 30, 1998
Status of this Memo
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Abstract
This Internet-Draft specifies the mapping between (1) the commands
and operands of the "Line Printer Daemon (LPD) Protocol" specified
in RFC 1179 and (2) the operations and parameters of the Internet
Printing Protocol (IPP). One of the purposes of this document is
to compare the functionality of the two protocols. Another purpose
is to facilitate implementation of gateways between LPD and IPP.
WARNING: RFC 1179 was not on standards track. While RFC 1179 was
intended to record existing practice, it fell short in some areas.
However, this specification maps between (1) the actual current
practice of RFC 1179 and (2) IPP. This document does not attempt
to map the numerous divergent extensions to the LPD protocol that
have been made by many implementers.
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TABLE OF CONTENTS
1. Introduction........................................................3
2. Terminology.........................................................3
3. Mapping from LPD Commands to IPP Operations.........................4
3.1 Print any waiting jobs ...........................................4
3.2 Receive a printer job ............................................4
3.2.1 Abort job ....................................................5
3.2.2 Receive control file .........................................6
3.2.3 Receive data file ............................................6
3.3 Send queue state (short) .........................................6
3.4 Send queue state (long) ..........................................8
3.5 Remove jobs ......................................................9
4. Mapping of LPD Control File Lines to IPP Parameters................10
4.1 Required Job Functions ..........................................10
4.2 Optional Job Functions ..........................................11
4.3 Required Document Functions .....................................12
4.4 Recommended Document Functions ..................................13
5. Mapping from IPP operations to LPD commands........................13
5.1 Get-Operations ..................................................13
5.2 Print-Job .......................................................13
5.3 Print-URI .......................................................14
5.4 Validate-Job ....................................................15
5.5 Create-Job ......................................................15
5.6 Send-Document ...................................................15
5.7 Send-URI ........................................................15
5.8 Cancel-Job ......................................................15
5.9 Get-Attributes ..................................................16
5.10 Get-Jobs .......................................................17
6. Mapping of IPP Parameters to LPD Control File Lines................17
6.1 Required Job Functions ..........................................17
6.2 Optional Job Functions ..........................................18
6.3 Required Document Functions .....................................18
7. References.........................................................19
8. Author's Addresses.................................................19
9. Appendix A: ABNF Syntax for response of Send-queue-state (short)...20
10. Appendix B: ABNF Syntax for response of Send-queue-state (long)...20
11. Appendix C: Unsupported LPD functions.............................21
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Mapping between the LPD and IPP Protocols
1. Introduction
The reader of this specification is expected to be familiar with the IPP
Model and Semantics specification [1], the IPP Protocol specification
[2], and the Line Printer Daemon (LPD) protocol specification [3] as
described in RFC 1179.
RFC 1179 was written in 1990 in an attempt to document existing LPD
protocol implementations. Since then, a number of undocumented
extensions have been made by vendors to support functionality specific
to their printing solutions. All of these extensions consist of
additional control file commands. This document does not address any of
these vendor extensions. Rather it addresses existing practice within
the context of the features described by RFC 1179. Deviations of
existing practice from RFC 1179 are so indicated.
Other LPD control file commands in RFC 1179 are obsolete. They are
intended to work on "text" only formats and are inappropriate for many
contemporary document formats that completely specify each page. This
document does not address the support of these obsolete features.
In the area of document formats, also known as page description
languages (PDL), RFC 1179 defines a fixed set with no capability for
extension. Consequently, some new PDL's are not supported, and some of
those that are supported are sufficiently unimportant now that they have
not been registered for use with the Printer MIB[4] and IPP[1] [2],
though they could be registered if desired. See the Printer MIB
specification [4] and/or the IPP Model specification [1] for
instructions for registration of document-formats with IANA. IANA lists
the registered document-formats as "printer languages".
This document addresses the protocol mapping for both directions:
mapping of the LPD protocol to the IPP protocol and mapping of the IPP
protocol to the LPD protocol. The former is called the "LPD-to-IPP
mapper" and the latter is called the "IPP-to-LPD mapper".
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [6].
RFC 1179 uses the word "command" in two contexts: for over-the-wire
operations and for command file functions. This document SHALL use the
word "command" for the former and the phrase "functions" for the latter.
The syntax of the LPD commands is given using ABNF [6].
The following tokens are used in order to make the syntax more readable:
LF stands for %x0A (linefeed)
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SP stands for %x20. (space)
DIGIT stands for %x30-39 ("0" to "9")
3. Mapping from LPD Commands to IPP Operations
This section describes the mapping from LPD commands to IPP operations.
Each of the following sub-sections appear as sub-sections of section 5
of RFC 1179.
The following table summarizes the IPP operation that the mapper uses
when it receives an LPD command. Each section below gives more detail.
LPD command IPP operation
print-any-waiting-jobs ignore
receive-a-printer-job Print-Job or Create-Job/Send-Document
send queue state Get-Attributes (printer) and Get-Jobs
(short or long)
remove-jobs Cancel-Job
3.1 Print any waiting jobs
Command syntax:
print-waiting-jobs = %x01 printer-name LF
This command causes the LPD daemon check its queue and print any waiting
jobs. An IPP printer handles waiting jobs without such a nudge.
If the mapper receives this LPD command, it SHALL ignore it and send no
IPP operation.
3.2 Receive a printer job
Command syntax:
receive-job = %x02 printer-name LF
The control file and data files mentioned in the following paragraphs
are received via LPD sub-commands that follow this command. Their
mapping to IPP commands and attributes is described later in this
section.
The mapper maps the 'Receive a printer job' command to either:
. the Print-Job operation which includes a single data file or
. the Create-Job operation followed by one Send-Document
operation for each data file.
If the IPP printer supports both Create-Job and Send-Document, and if a
job consists of:
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. a single data file, the mapper SHOULD use the PrintJob
operation, but MAY use the Create-Job and Send-Document
operations.
. more than one data file, the mapper SHALL use Create Job
followed by one Send-Document for each received LPD data file.
If the IPP printer does not support both Create-Job and Send-Document,
and if a job consists of:
. a single data file, the mapper SHALL use the PrintJob
operation.
. more than one data file, the mapper SHALL submit each received
LPD data file as a separate Print-Job operation (thereby
converting a single LPD job into multiple IPP jobs).
If the mapper uses Create-Job and Send-Document, it MUST send the
Create-Job operation before it sends any Send-Document operations
whether the LPD control file, which supplies attributes for Create-Job,
arrives before or after all LPD data files.
NOTE: This specification does not specify how the mapper maps: the LPD
Printer-name operand to the IPP "printer-uri" parameter.
The following 3 sub-sections gives further details about the mapping
from LPD receive-a-printer-job sub-commands. Each of the following
sub-sections appear as sub-sections of section 6 of RFC 1179.
ISSUE: the mapper needs to maintain information such as the mapping of
each job-number to its corresponding job-URI. It would be nice for IPP
to support an "scratch-pad" attribute for the mapper to encode such
information. Then it wouldn't have to maintain this information
separately.
3.2.1 Abort job
Sub-command syntax:
abort-job = %x1 LF
This sub-command of receive-a-printer-job is intended to abort any job
transfer in process.
If the mapper receives this sub-command, it SHALL cancel the job that it
is in the process of transmitting.
If the mapper is in the process of sending a Print-Job or Create-Job
operation, it terminates the job either by closing the connection, or
performing the Cancel-Job operation with the job-uri that it received
from the Print-Job or Create-Job operation.
NOTE: This sub-command is implied if at any time the connection between
the LPD client and server is terminated before an entire print job has
been transferred via an LPD Receive-a-printer-job request.
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3.2.2 Receive control file
Sub-command syntax:
receive-control-file = %x2 number-of-bytes SP name-of-control-file LF
number-of-bytes = 1*DIGIT
name-of-control-file = "cfA" job-number client-host-name
; e.g. "cfA123woden"
job-number = 3DIGIT
client-host-name = <a host name>
This sub-command is roughly equivalent to the IPP Create-Job operation.
The mapper SHALL use the contents of the received LPD control file to
create IPP parameter and attribute values to transmit with the Print-Job
or Create-Job operation.
3.2.3 Receive data file
Sub-command syntax: %x3 number-of-bytes-in-data-file Name-of-data-file
receive-data-file = %x03 number-of-bytes SP name-of-data-file LF
number-of-bytes = 1*DIGIT
name-of-data-file = "df" letter job-number client-host-name
; e.g. "dfA123woden for the first file
letter = %x41-5A / %x61-7A ; "A" to "Z", "a" to "z"
; first file is "A",
; second "B", and 52nd file is "z"
job-number = 3DIGIT
client-host-name = <a host name>
This sub-command is roughly equivalent to the IPP Send-Document
operation.
The mapper SHALL use the contents of the received LPD data file as the
data to transmit with the IPP Print-Job or Send-Document operation.
Although RFC-1179 alludes to a method for passing an unspecified
length data file by using an octet-count of zero, no implementations
support this feature.. The mapper SHALL reject a job that has a value of
0 in the number-of-bytes field.
3.3 Send queue state (short)
Command syntax:
send-queue-short = %x03 printer-name *(SP(user-name / job-number)) LF
The mapper's response to this command includes information about the
printer and its jobs. RFC 1179 specifies neither the information nor the
format of its response. This document requires the mapper to follow
existing practice as specified in this document.
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The mapper SHALL produce a response in the following format which
consists of a printer-status line optionally followed by a heading line,
and a list of jobs. This format is defined by examples below. Appendix A
contains the ABNF syntax.
For an printer with no jobs, the response starts in column 1 and is:
no entries
For a printer with jobs, an example of the response is:
killtree is ready and printing
Rank Owner Job Files Total Size
active fred 123 stuff 1204 bytes
1st smith 124 resume, foo 34576 bytes
2nd fred 125 more 99 bytes
3rd mary 126 mydoc 378 bytes
4th jones 127 statistics.ps 4567 bytes
5th fred 128 data.txt 9 bytes
The column numbers of above headings and job entries are:
| | | | |
01 08 19 35 63
The mapper SHALL produce each field above from the following IPP
attribute:
LPD field IPP attribute special conversion details
printer- printer-state and For a printer-state of idle or
status printer-state-reasons processing, the mapper SHALL use
the formats above. For stopped,
the mapper SHALL use printer-
state-reasons to produce an
unspecified format for the error.
rank number-of- the mapper SHALL the format above
intervening-jobs
owner job-originating-user unspecified conversion; job-
originating-user may be the
mapper's user-name
job job-uri unspecified conversion
files document-name the mapper shall create a comma
separated list of the document-
names and then truncate this list
to the first 24 characters
total- job-k-octets the mapper shall multiple the
size value of job-k-octets by 1024.
A mapper SHOULD use the job attribute number-of-intervening-jobs rather
than the job's position in a list of jobs to determine `rank' because a
Printer may omit jobs that it wants to keep secret. If a printer doesn't
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support the job attribute number-of-intervening-jobs, a mapper MAY use
the job's position.
ISSUE: is job-k-octets the sum of the bytes of each document times the
number of copies? If so, "total-size" is 1024 times job-k-octets. The
model document needs clarification.
In order to obtain the information specified above, The LPD-to-IPP
mapper SHALL use the Get-Attributes operation of the printer to get
printer-status and SHOULD use the Get-Jobs operation to get information
about all of the jobs. If the LPD command contains job-numbers or user-
names, the mapper handles the filtering of the response because Get-Jobs
has no way to limit jobs to those of a particular user. If the LPD
command contains job-numbers but no user-names, the mapper MAY use Get-
Attributes on each converted job-number rather than Get-Jobs.
NOTE: This specification does not define how the mapper maps the LPD
Printer-name operand to the IPP "printer-uri" parameter.
3.4 Send queue state (long)
Command syntax:
send-queue-long = %x04 printer-name *(SP(user-name / job-number)) LF
The mapper's response to this command includes information about the
printer and its jobs. RFC 1179 specifies neither the information nor the
format of its response. This document requires the mapper to follow
existing practice as specified in this document.
The mapper SHALL produce a response in the following format which
consists of a printer-status line optionally followed a list of jobs,
where each job consists of a blank line, a description line, and one
line for each file. The description line contains the user-name, rank,
job-number and host. This format is defined by examples below. Appendix
B contain the ABNF syntax.
For an printer with no jobs the response is:
no entries
For a printer with jobs, an example of the response is:
killtree is ready and printing
fred: active [job 123 tiger]
2 copies of stuff 602 bytes
smith: 1st [job 124 snail]
2 copies of resume 7088 bytes
2 copies of foo 10200 bytes
fred: 2nd [job 125 tiger]
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more 99 bytes
The column numbers of above headings and job entries are:
| | |
01 09 41
Although the format of the long form is different from the format of the
short form, their fields are identical except for the copies and host
fields which are only in the long form. For fields other than the host
and copies fields, see the preceding section. For the host field see the
table below.
LPD field IPP attribute special conversion details
host job-originating-host unspecified conversion; job-
originating-host may be the
mapper's host
copies copies the mapper shall assume the
value of copies precedes the
string "copies of "; otherwise,
the value of copies is 1.
NOTE: This specification does not define how the mapper maps the LPD
Printer-name operand to the IPP printer-uri parameter.
3.5 Remove jobs
Command syntax:
remove-jobs = %x05 printer-name SP agent
*(SP(user-name / job-number)) LF
The agent operand is the user-name of the user initiating the remove-
jobs command. The special user-name 'root' indicates a privileged user
who can remove jobs whose user-name differs from the agent..
The mapper SHALL issue one Cancel-Job operation for each job referenced
by the remove-jobs command. Each job-number in the remove-jobs command
references a single job. Each user-name in the remove-jobs command
implicitly references all jobs owned by the specified user. The active
job is implicitly referenced when the remove-jobs command contains
neither job-numbers nor user-names. The mapper MAY use Get-Job to
determine the job-uri of implicitly referenced jobs.
The mapper SHALL not use the agent name of `root' when end-users cancel
their own jobs. Violation of this rule creates a potential security
violation, and it may cause the printer to issue a notification that
misleads a user into thinking that some other person canceled the job.
If the agent of a remove-jobs command for a job J is the same as the
user name specified with the `P' function in the control file for job J,
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then the mapper SHALL ensure that the caller of the Cancel-Job command
for job J is the same as job-originating-user for job J.
Note: This requirement means that a mapper must be consistent in who the
receiver perceives as the caller of IPP operations. The mapper either
acts as itself or acts on behalf of another user. The latter is
preferable if it is possible. This consistency is necessary between
Print-Job/Create-Job and Cancel-Job in order for Cancel-Job to work, but
it is also desirable for other operations. For example, Get-Jobs may
give more information about job submitted by the caller of this
operation.
NOTE: This specification does not define how the mapper maps: (1) the
LPD printer-name to the IPP "printer-uri" or (2) the LPD job-number to
the IPP "job-uri".
NOTE: This specification does not specify how the mapper maps the LPD
user-name to the IPP job-originating-user because the mapper may use its
own user-name with jobs.
4. Mapping of LPD Control File Lines to IPP Parameters
This section describes the mapping from LPD control file lines (called
`functions') to IPP operation input parameters. The mapper receives the
control file lines via the LPD receive-control-file sub-command.. Each
of the LPD functions appear as sub-sections of section 7 of RFC 1179.
In LPD control file lines, the text operands have a maximum length of 31
or 99 while IPP input parameters have a maximum of 255 characters.
Therefore, no data is lost.
The mapper converts each supported LPD function to its corresponding IPP
parameter as defined by tables in the subsections that follow. These
subsections group functions according to whether they are:
. required with a job,
. optional with a job
. required with each document.
In the tables below, each LPD value is given a name, such as `h'. If an
IPP value uses the LPD value, then the IPP value column contains the LPD
name, such as `h' to denote this. Otherwise, the IPP value column
specifies the literal value.
4.1 Required Job Functions
The following LPD functions MUST be in a received LPD job. The mapper
SHALL receive each of the following LPD functions and SHALL include the
information as a parameter with each IPP job. The functions SHOULD be in
the order `H', `P' and they SHOULD be the first two functions in the
control file, but they MAY be anywhere in the control file and in any
order.
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LPD function IPP
name value description name value
H h Originating Host h (in security layer)
P u User identification u (in security layer)
none best-effort `true'
A mapper MAY sends its own host rather than the client's host, and a
mapper MAY send its own user-name as user identification rather than the
client user. But in any case, the values sent SHALL be compatible with
the Cancel-Job operation. The IPP operation MAY have no way to specify
an originating host-name.
ISSUE: what do we do about job-orginating-host?
The mapper SHALL include best-effort=true so that it doesn't have to
determine which attributes a printer supports.
4.2 Optional Job Functions
The following LPD functions MAY be in a received job. These function
SHOULD follow the required job functions and precede the document
functions, but they MAY be anywhere in the control file.
If the mapper receives such an LPD function, the mapper SHALL include
the corresponding IPP attribute with the value converted as specified in
the table below. If the mapper does not receive such an LPD attribute,
the mapper SHALL NOT include the corresponding IPP attribute, except the
`L' LPD function whose absence has a special meaning as noted in the
table.
LPD function IPP
name value description name value
J j Job name for job-name j
banner page
L l Print banner page job-sheets `standard' if `L' is
present
`none' if `L' is present
M m Mail When Printed notification- `job-completion'
events 'mailto://'m`@'h
notification-
method
Note: `m' is the user name and not an email address. The mapper can
fabricate an email address with the source host. This email address
mail fail when the `h' is some intermediary host that doesn't know about
user `m'. But there is no better solution.
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4.3 Required Document Functions
The mapper SHALL receive one set of the required document functions with
each copy of a document, and SHALL include the converted information as
parameters with each IPP document
If the control file contains required and recommended document
functions, the required functions SHOULD precede the recommended ones
and if the job contains multiple documents, all the functions for each
document are grouped together as shown in the example of section 6.3
"Required Document Functions". However, the document functions MAY be in
any order.
LPD function IPP
name valu description name value
e
f fff Print formatted document-format 37 (langAutomatic)
file
l fff Print file leaving document-format 37 (langAutomatic)
control characters
o fff Print Postscript document-format 6 (langPS).
output file
copies see note
Note: In practice, the `f' LPD function is often overloaded. It is often
used with any format of document data including PostScript and PCL data.
Note: In practice, the `l' LPD function is often used as a rough
equivalent to the `f' function.
Note: When RFC 1179 was written, no implementation supported the `o'
function; instead `f' was used for PostScript. Windows NT now sends `o'
function for a PostScript file.
Note: the value `fff' of the `f', `l' and `o' functions is the name of
the data file as transferred, e.g. "dfA123woden".
If the mapper receives any other lower case letter, the mapper SHALL
reject the job because the document contains a format that the mapper
does not support.
The mapper determines the number of copies by counting the number of
occurrences of each `fff' file with one of the lower-case functions
above. For example, if `f dfA123woden' occurs 4 times, then copies has a
value of 4. Although the LPD protocol allows the value of copies to be
different for each document, the commands and the receiving print
systems don't support this.
ISSUE: should we register DVI, ditroff and troff. At least DVI and one
of the troff is still in use.
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4.4 Recommended Document Functions
The mapper SHOULD receive one set of the recommended document functions
with each document, and SHOULD include the converted information as
parameters with each IPP document. The functions SHOULD be received in
the order `U' and `N', but they MAY arrive in any order.
LPD function IPP
name value description name value
U fff ignored
N n Name of source file document-name n
Note: the value `fff' of the `U' function is the name of the data file
as transferred, e.g. "dfA123woden".
5. Mapping from IPP operations to LPD commands
If the IPP-to-LPD mapper receives an IPP operation, the following table
summarizes the LPD command that it uses. Each section below gives the
detail. Each of the following sub-sections appear as sub-sections of
section 3 in the document "Internet Printing Protocol/1.0: Model and
Semantics" [1].
IPP operation LPD command
Get-Operations implemented by the mapper
Print-Job or Print-URI or receive-a-printer-job
Create-Job/Send-Document/Send-URI and then print-any-waiting-jobs
Validate-Job implemented by the mapper
Cancel-Job remove-jobs
Get-Attributes (printer or job) send queue state (short or long)
or Get-Jobs
5.1 Get-Operations
The mapper SHALL return a list of the operations that it supports. It
SHALL support at least those operations that are mandatory according to
the IPP model document [1].
5.2 Print-Job
The mapper SHALL send the following commands in the order listed below:
. receive-a-printer-job command
. both receive-control-file sub-command and receive-data-file
sub-command
(unspecified order, see Note below)
. print-any-waiting-jobs command,
except that if the mapper is sending a sequence of receive-a-
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printer-job commands, it MAY omit sending print-any-waiting-
jobs after any receive-a printer-job command that is neither
the first nor last command in this sequence
Note: it is recommended that the order of the receive-control-file sub-
command and the receive-data-file sub-command be configurable because
either order fails for some print systems. Some print systems assume
that the control file follows all data files and start printing
immediately on receipt of the control file. When such a print system
tries to print a data file that has not arrived, it produces an error.
Other print systems assume that the control file arrives before the data
files and start printing when the first data file arrives. Such a system
ignores the control information, such as banner page or copies.
NOTE: This specification does not define the mapping between the IPP
printer-uri and the LPD printer-name.
The mapper SHALL send the IPP parameters and attributes received from
the operation to the LPD printer by using the LPD receive-control-file
sub-command. The mapper SHALL create the job-number for use in the
control file name, but the receiving printer MAY, in some circumstances,
assign a different job-number to the job. The mapper SHALL create the
job-uri returned in the Print-Job response.
NOTE: This specification does not specify how the mapper determines the
job-number or the job-uri of a job that it creates nor does it specify
the relation ship between the job-uri and the job-number, both of which
the mapper creates.
The mapper SHALL send data received in the IPP operation to the LPD
printer by using the LPD receive-data-file sub-command. The mapper SHALL
specify the exact number of bytes being transmitted in the number-of-
bytes field of the receive-data-file sub-command. It SHALL NOT use a
value of 0 in this field.
If the mapper, while it is transmitting a receive-a-printer-job command
or sub-command, either detects that its IPP connection has closed or
receives a Cancel-Job operation, the mapper SHALL terminate the LPD job
either with the abort sub-command or the remove-jobs command.
ISSUE: error code conversion.
5.3 Print-URI
The mapper SHALL handle this operation in the same way as a Print-Job
operation except that it SHALL obtain data referenced by the "document-
uri" parameter and SHALL then treat that data as if it had been received
via a Print-Job operation.
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5.4 Validate-Job
The mapper SHALL perform this operation directly. Because LPD supports
very few attributes, this operation doesn't have much to check.
5.5 Create-Job
The mapper SHALL handle this operation like Print-Job, except
. the mapper SHALL send the control file after it has received
the last Send-Document or Send-URI operation because the
control file contains all the document-name and document-
format values specified in the Send-Document and Send-URI
operations.
. the mapper SHALL perform one receive-data-file sub-command for
each Send-Document or Send-URI operation received and in the
same order received.
. the mapper SHALL send the control file either before all data
files or after all data files.
(See the note in the section on Print-Job about the dilemma of
sending the control file either before or after the data
files.
5.6 Send-Document
The mapper performs a receive-data-file sub-command on the received
data. See the preceding section 5.5 "Create-Job" for the details.
5.7 Send-URI
The mapper SHALL obtain the data referenced by the "document-uri"
parameter, and SHALL then treat that data as if it had been received via
a Send-Document operation. See the preceding section 5.6 "Send-Document"
for the details.
5.8 Cancel-Job
The mapper SHALL perform a remove-jobs command with the following
parameters:
. the printer is the one containing the job specified by the IPP
job-uri,
. the agent is the authenticated user-name of the IPP client,
. the job-number is the one corresponding to the IPP job-uri
parameter.
NOTE: This specification does not specify how the mapper maps the IPP
"job-uri" to the LPD printer-name or LPD job-number.
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ISSUE: the model needs to offer a solution for mapping jobs to printers
either with a new job attribute "printer-uri" or with all operation
targets being a printer-uri.
5.9 Get-Attributes
LPD severely limits the set of attributes that the mapper is able to
return in its response for this operation.
When the mapper receives a Get-Attributes operation for a printer
object, it SHALL support, at most, the following printer attributes:
. printer-state
. printer-state-reasons
When the mapper receives a Get-Attributes operation for a job object, it
SHALL support, at most, the following job attributes:
. number-of-intervening-jobs
. job-originating-user
. job-uri
. job-originating-host
. document-name
. job-k-octets
. copies
The mapper uses either the long or short form of the "send queue state"
command. If it receives a request for the "job-originating-host" or
"copies" and supports those attribute it SHALL use the long form;
otherwise, it SHALL use the short form.
Note: the value of job-k-octets is the value in the short form, but it
can be computed from the copies and file size fields in the long form.
The mapper SHALL assume that the LPD response that it receives has the
format and information specified in section 3.3 "Send queue state
(short)" and section 3.4 "Send queue state (long)". The mapper SHALL
determine the value of each requested attribute by using the inverse of
the mapping specified in the two aforementioned sections.
Note: when the mapper receives the Get-Attributes operation for a
printer, it can determine the response from the printer-status line
without examining the rest of the LPD response. When the mapper receives
the Get-Attributes operation for a job and uses the LPD short form, it
can determine the response from the single line that pertains to the job
specified by the Get-Attributes operation.
NOTE: For Get-Attributes of a job, this specification does not specify
how the mapper maps the IPP "job-uri" to the LPD printer-name or LPD
job-number.
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5.10 Get-Jobs
The mapper SHALL perform this operation in the same way as Get-
Attributes of a printer except that the mapper converts the job-lines,
and the IPP response contains one job object for each job in the LPD
response..
6. Mapping of IPP Parameters to LPD Control File Lines
This section describes the mapping from IPP operation input parameters
to LPD control file lines (called `functions'). The mapper receives the
IPP operation input parameters via the IPP operation. Each of the IPP
operation input parameters appear as sub-sections of section 3 and 4.2
in the IPP model document [1].
In the context of LPD control file lines, the text operands have a
maximum length of 31 or 99 while IPP input parameters have a maximum of
255 characters. Therefore, there may be some data loss if the IPP
parameters exceed the maximum length of the LPD equivalent operands.
The mapper converts each supported IPP parameter to its corresponding
LPD function as defined by tables in the subsections that follow. These
subsections group functions according to whether they are:
. required with a job,
. optional with a job
. required with each document.
In the tables below, each IPP value is given a name, such as `h'. If an
LPD value uses the IPP value, then the LPD value column contains the IPP
name, such as `h' to denote this. Otherwise, the LPD value column
specifies the literal value.
6.1 Required Job Functions
The mapper SHALL include the following LPD functions with each job, and
they SHALL have the specified value. They SHALL be the first functions
in the control file and they SHALL be in the order "H" and then "P".
IPP LPD function
name value name value description
(in security layer) h H gateway host Originating Host
(in security layer) u P u User identification
A mapper SHALL sends its own host rather than the client's host, because
some LPD systems require that it be the same as the host from which the
remove-jobs command comes. A mapper MAY send its own user name as user
identification rather than the client user. But in any case, the values
sent SHALL be compatible with the LPD remove-jobs operation.
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6.2 Optional Job Functions
The mapper MAY include the following LPD functions with each job. They
SHALL have the specified value if they are sent. These functions, if
present, SHALL follow the require job functions, and they SHALL precede
the required document functions.
IPP attribute LPD function
name value nam value description
e
job-name j J j Job name for banner
page
job-sheets `standard' L u Print banner page
job-sheets `none' omit `L' function
notification- `job-completion' user Mail When Printed
user`@' M events `mailto://'
notification- host
method
Note: `L' has special meaning when it is omitted. If `M' is omitted,
there is no notification. If `J' is omitted, some undefined behavior
occurs with respect to the banner page.
Note: the `user' for the `M' function comes from a substring of the
notification-method's value.
6.3 Required Document Functions
The mapper SHALL include one set of the following LPD functions with
each document, and they SHALL have the specified values. For each
document, the order of the functions SHALL be `f', `U' and then `N',
where `f' is replicated once for each copy.
IPP attribute LPD function
name value name value description
document- `37' (langAutomatic) f fff Print formatted file
format or `6' (langPS).
copies c replicate `f' `c'
times
none U fff Unlink data file
document- n N n Name of source file
name
Note: the value `fff' of the `f' and `U' functions is the name of the
data file as transferred, e.g. "dfA123woden".
Note: the mapper SHALL not send the `o' function
ISSUE: should we register DVI, troff or ditroff?
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If the mapper receives no "best-effort" or it has a value of false, then
the mapper SHALL reject the job if it specifies attributes or attribute
values that are not among those supported in the above tables.
Below is an example of the minimal control file for a job with three
copies of two files `foo' and `bar':
H tiger
P jones
f dfA123woden
f dfA123woden
f dfA123woden
U dfA123woden
N foo
f dfB123woden
f dfB123woden
f dfB123woden
U dfB123woden
N bar
7. References
[1] R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell, "Internet
Printing Protocol/1.0: Model and Semantics", <draft-ietf-ipp-model-
02.txt>, July 1997.
[2] R. Herriot, S. Butler, P. Moore, R. Turner, "Internet Printing
Protocol/1.0: Protocol specification", <draft-ietf-ipp-protocol-00.txt>,
July 1997.
[3] L. McLaughlin, "Line Printer Daemon Protocol", RFC 1179, August
1990.
[4] Smith, R., Wright, F., Hastings, T., Zilles, S., and Gyllenskog, J.,
"Printer MIB", RFC 1759, March 1995.
[5] S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119 , March 1997
[6] D. Crocker et al., "Augmented BNF for Syntax Specifications: ABNF",
draft-ietf-drums-abnf-03.txt.
8. Author's Addresses
Robert Herriot (editor) Norm Jacobs
Sun Microsystems Inc. Sun Microsystems Inc.
901 San Antonio.Road., MPK-17 1430 Owl Ridge Rd.
Mountain View, CA 94043 Colorado Springs, CO 80919
Phone: 650-786-8995 Phone: 719-532-9927
Fax: 650-786-7077 Fax: 719-535-0956
Email: robert.herriot@eng.sun.com Email:
Norm.Jacobs@Central.sun.com
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Thomas N. Hastings Jay Martin
Xerox Corporation Underscore, Inc.
701 S. Aviation Blvd., ESAE-231 41-C Sagamore Park Road
El Segundo, CA 90245 Hudson, NH 03051-4915
Phone: 310-333-6413 Phone: 603-889-7000
Fax: 310-333-5514 Fax: 603-889-2699
EMail: hastings@cp10.es.xerox.com Email: jkm@underscore.com
9. Appendix A: ABNF Syntax for response of Send-queue-state (short)
The syntax in ABNF for the response to the LPD command `send-queue-state
(long)' is:
status-response = empty-queue / nonempty-queue
empty-queue = "no-entries" LF
nonempty-queue = printer-status LF heading LF *(job LF)
printer-status = OK-status / error-status
OK-status = printer-name SP "ready and printing" LF
error-status = < implementation dependent status information >
heading = "Rank" 3SP Owner 6SP "Job" 13SP "Files"
23SP "Total Size" LF
; the column headings and their values below begin
at the columns
; 1, 8, 19, 35 and 63
job = rank *SP owner *SP job *SP files *SP total-size "bytes"
; jobs are in order of oldest to newest
rank = "active" / "1st" / "2nd" / "3rd" / integer "th"
; job that is printing is "active"
; other values show position in the queue
owner = <user name of person who submitted the job>
job = 1*3DIGIT ; job-number
files = <file name> *( "," <file name>) ; truncated to 24 characters
total-size = 1*DIGIT ; combined size in bytes of all documents
10. Appendix B: ABNF Syntax for response of Send-queue-state (long)
The syntax in ABNF for the response to the LPD command `send-queue-state
(long)' is:
status-response = empty-queue / nonempty-queue
empty-queue = "no-entries" LF
nonempty-queue = printer-status LF *job
printer-status = OK-status / error-status
OK-status = printer-name SP "ready and printing" LF
error-status = < implementation dependent status information >
job = LF line-1 LF line-2 LF
line-1 = owner ":" SP rank 1*SP "[job" job SP host "]"
line-2 = file-name 1*SP document-size "bytes"
; jobs are in order of oldest to newest
rank = "active" / "1st" / "2nd" / "3rd" / integer "th"
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; job that is printing is "active"
; other values show position in the queue
owner = <user name of person who submitted the job>
job = 1*3DIGIT
file-name = [ 1*DIGIT "copies of" SP ] <file name>
; truncated to 24 characters
document-size = 1*DIGIT ;size of single copy of the document.
11. Appendix C: Unsupported LPD functions
The follow LPD functions have no IPP equivalent. The LPD-to-IPP mapper
ignores them and the IPP-to-LPD mapper does not send them.
LPD command
name description
C Class for banner page
I Indent Printing
S Symbolic link data
T Title for pr
W Width of output
1 troff R font
2 troff I font
3 troff B font
4 troff S font
The follow LPD functions specify document-formats which have no IPP
equivalent, unless someone registers them. The LPD-to-IPP mapper rejects
jobs that request such a document format, and the IPP-to-LPD mapper does
not send them.
LPD command
name description
c Plot CIF file
d Print DVI file
g Plot file
k reserved for Kerberized clients and servers
n Print ditroff output file
p Print file with 'pr' format
r File to print with FORTRAN carriage control
t Print troff output file
v Print raster file
z reserved for future use with the Palladium
print system
ISSUE: we may move some of these to the supported list.
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