HFAXD(8C)HFAXD(8C)NAMEhfaxd - HylaFAX client-server protocol server
SYNOPSIS
/usr/sbin/hfaxd [ -d ] [ -D secs ] [ -q dir ] [ -o port ] [ -O ] [ -l
bindaddress ] [ -i port ] [ -I ] [ -s port ] [ -S ]
DESCRIPTIONhfaxd is the HylaFAX program that implements the server portion of:
· the client-server protocol and
· the Simple Network Paging Protocol (SNPP) used to submit message
pager jobs to the IXO/TAP and UCP support.
Additional client-server protocols are planned and hfaxd is intended to
be the ``carrier'' through which they are supported.
hfaxd is typically used in one of two ways; either as a stand-alone
process that is started at system boot time to listen for client con‐
nections on one or more ports (in which case the -i, -o, or -s option
must be used), or as a subservient process to the inetd(8C) program.
The two forms of use may however be combined so long as the same ser‐
vice is not provided both by the stand-alone hfaxd and through inetd.
HYLAFAX CLIENT-SERVER PROTOCOL SUPPORT
If hfaxd is started with the -i option it will service clients using
the HylaFAX client-server protocol. This protocol is strongly related
to the Internet File Transfer Protocol (FTP); so much so in fact that
FTP client programs that include support for ``quoted commands'' may be
used to communicate with hfaxd using the new protocol. (It should also
be possible to use FTP-aware World Wide Web browsers such as Mosaic and
Netscape Navigator to access HylaFAX servers through the new protocol;
but the current format for information returned in directory listings
confuses them.)
The hfaxd server currently recognizes the following protocol requests;
case is not distinguished. Entries marked with a ¹ can be used only
when the client has established administrative privileges with ADMIN.
Request Description
ABOR abort previous command
ACCT specify account (ignored)
ADMIN specify password for administrative privileges
ALLO allocate storage (vacuously)
ANSWER¹ request that call be answered
APPE append to a file
CDUP change to parent of current working directory
CHMOD change mode of a file
CHOWN¹ change owner of a file
CWD change working directory
DELE delete a file
DISABLE¹ disable outbound use of modem
ENABLE¹ enable outbound use of modem
HELP give help information
FILEFMT specify/query format for returning file status
FORM specify data transfer format
IDLE set idle-timer (in seconds)
JDELE delete done or suspended job
JINTR interrupt job
JKILL kill job
JNEW create new job
JOB set/query current job
JOBFMT specify/query format for returning job status
JPARM specify/query job state parameter
JREST reset current job state
JSUBM submit job to scheduler
JSUSP suspend job from scheduling
JWAIT wait for job to complete
JGDELE delete group of jobs
JGKILL kill group of jobs
JGINTR interrupt group of jobs
JGNEW place current job in a new job group
JGPARM set state parameter in a group of jobs
JGREST reset current state for a group of jobs
JGRP set/query current job group
JGSUBM submit group of jobs to scheduler
JGSUSP suspend group of jobs from scheduling
JGWAIT wait for group of jobs to complete
LIST list files in a directory
MDTM show last modification time of file
MODE specify data transfer mode
MDMFMT specify/query format for returning modem status
NLST give name list of files in directory
NOOP do nothing
PASS specify password
PASV prepare for server-to-server transfer
PORT specify data connection port
PWD print the current working directory
QUIT terminate session
RCVFMT specify/query format for returning received facsimile status
REIN reinitiate server state
REST restart incomplete transfer
RETP retrieve the next page in a file
RETR retrieve a file
SHUT schedule server shutdown
SITE non-standard commands (see next section)
SIZE return size of file
STAT return status of server or file
STOR store a file
STOT store a temporary file with a unique name
STOU store a file with a unique name
STRU specify data transfer structure
SYST show operating system type of server system
TYPE specify data transfer type
TZONE specify timezone handling for dates and times
USER specify user name
VRFY verify dialstring handling and/or least-cost routing
The following non-standard or experimental commands are supported
through the SITE request.
Request Description
ADDMODEM¹ add/configure new modem for use
ADDUSER¹ add client access control entry
CONFIG¹ send configuration parameter setting to server
DELMODEM¹ deconfigure/remove modem
DELUSER¹ remove client access control entry
TRIGGER register real-time event trigger
HELP give help information, e.g., SITE HELP
In addition FTP requests that are specified in Internet RFC 959 but not
listed here are recognized, but not implemented.
The hfaxd server will abort an active data transfer only when the ABOR
command is preceded by a Telnet "Interrupt Process" (IP) signal and a
Telnet "Synch" signal in the command Telnet stream, as described in
Internet RFC 959. If a STAT command is received during a data trans‐
fer, preceded by a Telnet IP and Synch, transfer status will be
returned.
SIMPLE NETWORK PAGING PROTOCOL (SNPP) SUPPORT
If hfaxd is started with the -s option it will service clients using
the Simple Network Pager Protocol (SNPP) as specified in RFC 1861
(which obsoletes RFC 1645).
The hfaxd server currently recognizes the SNPP protocol requests listed
below. Requests marked with a ¹ are non-standard extensions to RFC
1861 that may be added to SNPP at some future time. Case is not dis‐
tinguished and only the first four characters of requests are used in
identifying commands.
Request Description
2WAY preface a 2-way transaction
ABOR¹ abort previous command
ACKR set read acknowledgement handling for subsequent requests
ALER set the alter-level for subsequent requests
CALL set the caller-ID for subsequent requests
COVE set the alternate coverage area for subsequent requests
DATA specify a multi-line message
EXPT set the expiration time for subsequent requests
HELP give help information
HOLD set the time at which subsequent requests are to be delivered
KTAG kill a previously submitted request
LEVE set the service level for subsequent requests
LOGI login to server
MCRE specify multiple response text and code
MESS specify a single-line message
MSTA return the status of a previously submitted request
NOQU disable message queueing
PAGE specify the destination pager
PING locate/validate a pager
QUIT terminate session
RESE reset server state
RTYP set the reply type code for subsequent requests
SEND send message(s)
SITE¹ site-specific commands (see next section)
STAT¹ return server status
SUBJ set the message text for subsequent requests
The hfaxd server will abort an active SEND operation when an ABOR com‐
mand is preceded by a Telnet "Interrupt Process" (IP) signal and a Tel‐
net "Synch" signal in the command Telnet stream.
The following non-standard or experimental commands are also supported
through the SITE request.
Request Description
FROMUSER specify the sender's identity
IDLE set idle-timer (in seconds)
JPARM query job parameter status
JQUEUE control whether or not job is queued
LASTTIME set the time to terminate an unfinished job
MAILADDR set the e-mail address to use for notification
MAXDIALS set the maximum number of times to dial the phone
MAXTRIES set the maximum number of times to try sending the page
MODEM set the modem or class of modems to use
NOTIFY set the e-mail notification
RETRYTIME set the time to delay between job retries
SCHEDPRI set the scheduling priority for the job
HELP give help information, e.g., SITE HELP
Note that hfaxd requires that SNPP clients login first with the LOGI
directive while RFC 1861 permits clients to submit pages anonymously.
CLIENT ACCESS CONTROLhfaxd controls client access according to the information in the file
/var/spool/fax/etc/hosts.hfaxd. This file defines the set of users and
machines that may receive service and, optionally, defines password
challenges to use in authenticating clients. Clients may be permitted
access to services with or without a password challenge. Access may
also be restricted based on the host machine that a request for service
originates from. Consult hosts.hfaxd(5F) for information on the format
and content of this file. The SITE ADDUSER protocol request is pro‐
vided for adding new users to a server (available only to clients with
administrative privileges).
Server resources are controlled based on clients' identities. Jobs and
documents, both received and submitted, are protected by the server.
Typically clients are permitted access to anything they own or that is
publicly accessible. There are also administrative privileges that
clients may acquire and which permit them wide access to objects that
reside on the server.
A complete client-server protocol specification is still outstanding.
hfaxd operates with its root directory set to the top of the HylaFAX
spooling area; /var/spool/fax. This is done so that clients see a vir‐
tual file hierarchy that is completely contained within the HylaFAX
operating environment on the server machine. Administrators however
must be aware of this action when specifying files in the hfaxd config‐
uration file: absolute pathnames relative to the root of the spooling
should be used to specify filenames.
SERVER ACCESS CONTROL
The file /var/spool/fax/etc/shutdown, when present, specifies when to
restrict access to a server machine. When this file is present and
contains valid information hfaxd will permit only users with adminis‐
trative privileges to access the server. Any other users that request
service will be denied access and negative server responses will
include any shutdown message specified in the shutdown file. Consult
hylafax-shutdown(5F) for information on the format and content of this
file.
The SHUT protocol request can be used to schedule a server shutdown; it
is available only to clients with administrative privileges. To make a
shutdown server available again the shutdown file can be deleted with
the DELE protocol request (this is to be replaced with an ``unshut''
protocol request so that implementation details are not part of the
protocol).
CONFIGURATION FILEShfaxd reads configuration information from the file
/usr/share/fax/hfaxd.conf each time a new server process is started
(i.e. for each new client). This file uses the same conventions used
by other HylaFAX configuration files; as described in hylafax-con‐
fig(5F). The following configuration parameters are recognized; items
marked ``(SNPP)'' are used only by the SNPP support.
Tag Type Default Description
FaxContact string see below contact address to show in help text
FileFmt string see below format string for file status results
IdleTimeout integer 900 client idle timeout in seconds
JobFmt string see below format string for job status results
JobProtection octal 0644 permissions for job qfiles in sendq/doneq
KillTimeMap string see below mapping from service level to job kill time (SNPP)
LDAPServerURI string URI of the ldap server including port number
LDAPBaseDN string LDAP context where user objects can be found
LDAPReqGroup string LDAP context of the users group
LDAPVersion integer 3 LDAP protocol version to use
LogFacility string daemon syslog facility name for tracing messages
MaxAdminAttempts integer 5 maximum admin attempts before disconnecting
MaxConsecutiveBadCmds integer 10 maximum invalid commands before disconnecting
MaxIdleTimeout integer 7200 maximum client idle timeout permitted
MaxLoginAttempts integer 5 maximum login attempts before disconnecting
MaxMsgLength integer 128 maximum pager message length (SNPP)
ModemFmt string see below format string for modem status results
PagerIDMapFile string /var/spool/fax/etc/pagermap name of file for mapping pager IDs (SNPP)
PriorityMap string see below mapping from service level to job priority (SNPP)
RcvFmt string see below format string for received facsimile status results
RecvqProtection octal 0444 permissions for client access to recvq
RetryTimeMap string see below mapping from service level to job retry time (SNPP)
ServerTracing integer 1 server tracing control vector
ShutdownFile string /var/spool/fax/etc/shutdown name of shutdown control file
UserAccessFile string /var/spool/fax/etc/hosts.hfaxd name of access control file
XferLogFile string /var/spool/fax/etc/clientlog name of file for logging client data transfers
The configuration parameters are explained below:
FaxContact
The e-mail address to display as a point of contact in the
help text returned to a client in response to the HELP or
SITE HELP commands. By default this is ``FaxMaster@host‐
name'', where hostname is the fully qualified name for the
machine where the server is running.
FileFmt The format string to use when returning file status informa‐
tion with the LIST and STAT commands. Formats are specified
using printf(3S) style conventions but using the field iden‐
tifiers listed below. Each item can include field width,
precision, left-justification, 0-filling, etc. just as for
printf; e.g. %-8p for an 8-character wide, left-justified,
blank-padded field containing the file protection flags.
Format Description
a Last access time
c Creation time
d Device number (octal)
f Filename
g Group identifier (decimal)
i Inode number (decimal)
l Link count (decimal)
m Last modification time
o Owner (based on file GID)
p Fax-style protection flags (no group bits)
q UNIX-style protection flags
r Root device number (octal)
s File size in bytes (decimal)
u User identifier (decimal)
The default format string is ``%-7p %3l %8o %8s %-12.12m
%.48f''. It is recommended that all items include a field
width so that client applications that construct headers from
the format string can constrain the width of column title
strings.
IdleTimeout
The initial/default timeout to use in timing out idle
clients. This value defines the maximum amount of time (in
seconds) that hfaxd will wait for a command from a client
before terminating the connection. Unprivileged clients may
alter the idle timeout up to the value of MaxIdleTimeout;
privileged clients may set the timeout to any value.
JobFmt The format string to use when returning job status informa‐
tion for jobs in the sendq and doneq directories. Formats
are specified using printf(3S) style conventions but using
the field identifiers listed below. Each item can include
field width, precision, left-justification, 0-filling, etc.
just as for printf; e.g. %-3j for a 3-character wide, left-
justified, blank-padded field containing the job state.
Format Description
A Destination SubAddress
B Destination Password
C Destination company name
D Total # dials/maximum # dials
E Desired signalling rate
F Client-specific tagline format string
G Desired min-scanline time
H Desired data format
I Client-specified scheduling priority
J Client-specified job tag string
K Desired use of ECM
L Destination geographic location
M Notification e-mail address
N Desired use of private tagline (one-character symbol)
O Whether to use continuation cover page (one-character symbol)
P # pages transmitted/total # pages to transmit
Q Client-specified minimum acceptable signalling rate
R Destination person (receiver)
S Sender's identity
T Total # tries/maximum # tries
U Page chopping threshold (inches)
V Job done operation
W Communication identifier
X Job type (one-character symbol)
Y Scheduled date and time
Z Scheduled time in seconds since the UNIX epoch
a Job state (one-character symbol)
b # consecutive failed tries
c Client machine name
d Total # dials
e Public (external) format of dialstring
f # consecutive failed dials
g Group identifier
h Page chop handling (one-character symbol)
i Current scheduling priority
j Job identifier
k Job kill time
l Page length in mm
m Assigned modem
n E-mail notification handling (one-character symbol)
o Job owner
p # pages transmitted
q Job retry time (MM::SS)
r Document resolution in lines/inch
s Job status information from last failure
t Total # tries attempted
u Maximum # tries
v Client-specified dialstring
w Page width in mm
x Maximum # dials
y Total # pages to transmit
z Time to send job
The default format string is ``%-4j %3i %1a %6.6o %-12.12e
%5P %5D %7z %.25s''. This string constrains each status line
to be less than 80 characters. It is recommended that all
items include a field width so that client applications, such
as faxstat(1) that construct headers from the format string
can constrain the width of column title strings.
JobProtection
The file mode setting for job qfiles in the HylaFAX queues
(sendq and doneq). The default setting of ``0644'' allows
all users to view all job parameters in the send and done
queues. The mode determines the permissions of the clients
to see the jobs, following the HylaFAX permission model of
the group bits controlling uid permissions and the other bits
controlling other permissions. A setting of ``0640'' allows
only the job owner and the administrator to view jobs. If a
user doesn't have permissions on the job, the job will not be
visible to them when viewing the queues.
KillTimeMap
The mapping from SNPP service level (0-11) to job expiration
time (kill time). A mapping is specified as a string of
space-separate numbers where each value is the number of min‐
utes to permit a job to run. The default mapping is ``5 5 5
15 60 240 720 1440 1440 1440 1440 1440'' which expires a job
in 5 minutes for service levels 0-2, 15 minutes for level
three, 60 minutes for level four, etc.
LDAPServerURI
The full address of the ldap server including port number,
i.e.: ldaps://1.2.3.4:636 (for secure connections) or
ldap://1.2.3.4:389 (for insecure connections)
LDAPBaseDN
The full LDAP context where user objects can be found, i.e.:
ou=users,dc=example,dc=com for Active Directory/LDAP or
ou=users,o=organization for Novell eDirectory
LDAPReqGroup
The full LDAP context of the group users have to be a member
of to gain HylaFAX access for sending faxes
LDAPVersion
Version number of the LDAP Protocol to use (default is '3')
LogFacility
The symbolic name for the syslog(3) facility to use when log‐
ging error messages and informational/debugging messages
requested through the ServerTracing parameter. The list of
facility names is found in the system include file <sys‐
log.h>; comparisons are case-insensitive.
MaxAdminAttempts
The maximum number of unsuccessful attempts gain administra‐
tive privileges with the ADMIN command that hfaxd will permit
a client before terminating the connection. Note that the
count of attempts is reset if/when the client successfully
gains administrative privileges.
MaxConsecutiveBadCmds
The maximum number of consecutive unrecognized, unimple‐
mented, syntactically incorrect, or otherwise unacceptable
commands to permit a client before terminating the connec‐
tion. This control has two purposes: to handle naive or
malicious clients from sending long streams of nonsense com‐
mands to a server, and to ensure that clients are forcibly
terminated when a server is marked shutdown.
MaxIdleTimeout
The maximum value that a client may set the idle timeout to.
This value is not enforced if the client has administrative
privileges.
MaxLoginAttempts
The maximum number of unsuccessful attempts to login with the
USER and PASS commands that hfaxd will permit a client before
terminating the connection.
MaxMsgLength
The maximum number of characters to accept in a pager message
specified with the DATA or MESS commands. Messages longer
than this value are rejected.
ModemFmt The format string to use when returning modem status informa‐
tion for modems listed in the status directory. Formats are
specified using printf(3S) style conventions but using the
field identifiers listed below. Each item can include field
width, precision, left-justification, 0-filling, etc. just as
for printf; e.g. %-8h for an 8-character wide, left-justi‐
fied, blank-padded field containing the name of the host the
server is running on.
Format Description
h Server hostname
l Local identifier string
m Canonical modem name
n FAX phone number
r Maximum pages that can be received in a single call
s Status information string
t Server and session tracing levels (xxxxx:yyyyy)
v Modem speaker volume as one-character symbol
z A ``*'' if a faxgetty(8C) process is running; otherwise `` '' (space)
The default format string is ``Modem %m (%n): %s''.
PagerIDMapFile
The absolute pathname of the file that contains directions
for mapping pager identifiers to IXO/TAP or UCP service
providers (and optionally a pager identification number).
Consult pagermap(5F) for information on the format and con‐
tent of this file. (Note that absolute pathnames are rela‐
tive to the root of the spooling area).
PriorityMap
The mapping from SNPP service level (0-11) to job scheduling
priority. A mapping is specified as a string of space-sepa‐
rate numbers where each value is the priority to assign to a
job. The default mapping is ``63 127 127 127 127 127 127 127
127 127 127 127'' which assigns a high priority to service
level zero and normal (default) priority to all other service
levels.
RcvFmt The format string to use when returning status information
for received facsimile in the recvq directory. Formats are
specified using printf(3S) style conventions but using the
field identifiers listed below. Each item can include field
width, precision, left-justification, 0-filling, etc. just as
for printf; e.g. %-3b for a 3-character wide, left-justified,
blank-padded field containing the signalling rate.
Format Description
X Reception indicator (1=yes, 0=no)
Y Received date and time
Z Received time in seconds since the UNIX epoch
a SubAddress received from sender (if any)
b Signalling rate used during receive
d Data format used during receive
e Error description if an error occurred during receive
f Document filename (relative to the recvq directory)
h Time spent receiving document (HH:MM:SS)
l Page length in mm
m Fax-style protection mode string (``-rwxrwx'')
n File size (number of bytes)
o File owner
p Number of pages in document
q UNIX-style protection flags
r Resolution of received data
s Sender identity (TSI)
t Compact representation of the time when the receive happened
w Page width in mm
z A ``*'' if receive is going on; otherwise `` '' (space)
The default format string is ``%-7m %4p%1z %-8.8o %14.14s %7t
%f''. This string constrains each status line to be less
than 80 characters. It is recommended that all items include
a field width so that client applications, such as faxstat(1)
that construct headers from the format string can constrain
the width of column title strings.
RecvqProtection
The permissions setting for administrator, owners, and users
for viewing files in the HylaFAX receive queue. The default
setting of ``0444'' allows all users to view all files in the
queues. A setting of ``0440'' allows only the job owner and
the administrator to view files. A setting of ``0040''
allows only the administrator to view the files. If a user
doesn't have permissions on the file, the file will not be
visible to them when viewing the queue.
RetryTimeMap
The mapping from SNPP service level (0-11) to job retry time.
A mapping is specified as a string of space-separate numbers
where each value is the number of seconds to delay between
delivery attempts. A value of zero causes retries to be
scheduled using the default algorithm used by the HylaFAX job
scheduler. The default mapping is ``30 60 60 180 0 0 0 0 0 0
0 0'' which retries a level 0 job after a 30 second delay,
levels 1 and 2 after 60 seconds, level 3 after 3 minutes, and
other jobs are retried according to the usual scheduling
algorithm.
ServerTracing
A number that controls the generation of tracing information
by a server. areas that are individually controlled. To
enable tracing of multiple areas of operation, the flag asso‐
ciated with each area should be bit-or'd to form the value
for this tag.
Flag Description
1 (0x00001) General server operation
2 (0x00002) Client-server protocol requests and responses
4 (0x00004) File transfers from client to server
8 (0x00008) File transfers from server to client
16 (0x00010) Client logins
32 (0x00020) All network connections
64 (0x00040) FIFO messages to and from faxq(8C)
128 (0x00080) TIFF Library errors and warnings
256 (0x00100) Configuration file processing
Tracing messages are directed to syslog(3) using the facility
specified with the LogFacility configuration parameter. Note
that syslogd(8C) must be configured to capture facility.info,
facility.debug, facility.warning, and facility.err messages.
ShutdownFile
The absolute pathname of the server shutdown file; see
hylafax-shutdown(5F) for information on the format and con‐
tent of this file. (Note that absolute pathnames are rela‐
tive to the root of the spooling area).
UserAccessFile
The absolute pathname of the user access control file; see
hosts.hfaxd(5F) for information on the format and content of
this file. (Note that absolute pathnames are relative to the
root of the spooling area).
XferLogFile
The absolute pathname of the file to use for logging client-
server file transfers (when enabled through the ServerTracing
parameter). (Note that absolute pathnames are relative to
the root of the spooling area).
OPTIONS-q dir The specified directory is treated as the spooling area. The
default spooling area, /var/spool/fax, is defined at the time
the software is built.
-d Stop hfaxd from detaching itself from the controlling termi‐
nal. This option is normally used only when running hfaxd
under a debugger or when hfaxd is started up from the
inetd(8C) process.
-D secs Sleep for the specified number of seconds before actually
processing the client to allow a debugger to attach.
-l bindaddress
Bind to the specified bindaddress the tcp port. Please note
that this argument need to be specified before the -i other‐
wise it will be ignored. A better approach to improve secu‐
rity would be to run hfaxd from xinetd, binding its service
to the specific port. This will also make hylafax benefits
from tcp wrappers and other options provided by xinetd.
-i port Listen on the specified port for service requests and respond
with the client-server protocol. The port may be specified
either symbolically, e.g. ``hylafax'' or numerically. This
flag may be specified multiple times to request service on
multiple different ports.
-s port Listen on the specified port for service requests and respond
with the Simple Network Paging (SNPP) protocol. The port may
be specified either symbolically, e.g. ``snpp'' or numeri‐
cally. This flag may be specified multiple times to request
service on multiple different ports.
-I Service the client-server protocol using the standard input
and output. This option is useful when hfaxd is started up
by inetd(8C).
-S Service the Simple Network Paging (SNPP) protocol using the
standard input and output. This option is useful when hfaxd
is started up by inetd(8C).
DIAGNOSTICS
Diagnostics generated by hfaxd are logged using syslog(3).
FILES
/usr/share/fax/hfaxd.conf server configuration file
/var/spool/fax spooling area
/var/spool/fax/FIFO for submitting the job
/var/spool/fax/sendq where job description is placed
/var/spool/fax/sendq/seqf for assigning job identifiers
/var/spool/fax/docq/seqf for assigning document identifiers
/var/spool/fax/tmp temporary location of job-related files
/var/spool/fax/docq where document files are placed
/var/spool/fax/recvq where received facsimile are found
/var/spool/fax/archive where archived jobs are placed
/var/spool/fax/log for server log files
/var/spool/fax/client for FIFO files used in communicating with faxq
/var/spool/fax/status for server status information
/var/spool/fax/config.device for returning server status
/var/spool/fax/etc/hosts.hfaxd host access control list
/var/spool/fax/etc/shutdown server shutdown control
/var/spool/fax/etc/pagermap SNPP pager ID mapping file
BUGS
To be filled in.
SEE ALSOsendfax(1), sendpage(1), faxalter(1), faxrm(1), faxstat(1), faxq(8C),
syslog(3)hylafax-server(5F), hosts.hfaxd(5F), status(5F), hylafax-
shutdown(5F),
July 12, 1996 HFAXD(8C)
