HFAXD(8C)
NAME
hfaxd - HylaFAX client-server protocol server
SYNOPSIS
/usr/local/sbin/hfaxd [ -d ] [ -q dir ] [ -o port ] [ -O ]
[ -i port ] [ -I ] [ -s port ] [ -S ]
DESCRIPTION
hfaxd is the HylaFAX program that implements the server
portion of:
+o the (new) client-server protocol,
+o the old client-server protocol previously implemented
by the faxd.recv program, and
+o the Simple Network Paging Protocol (SNPP) used to sub-
mit 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
standalone process that is started at system boot time to
listen for client connections on one or more ports, or as
a subservient process to the inetd(8C) program. The two
forms of use may however be combined so long as the same
service is not provided both by the standalone hfaxd and
through inetd.
HYLAFAX (NEW) CLIENT-SERVER PROTOCOL SUPPORT
If hfaxd is started with the -i option it will service
clients using the (new) 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 com-
mands'' 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 proto-
col; but the current format for information returned in
directory listings confuses them.)
The hfaxd server currently recognizes the following proto-
col requests; case is not distinguished. Entries marked
with a 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)
ANSWER request that call be answered
APPE append to a file
CDUP change to parent of current working directory
CHMOD change mode of a file
CHOWN change owner of a file
CWD change working directory
DELE delete a file
DISABLE disable outbound use of modem
ENABLE 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 returing 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
ADDMODEM add/configure new modem for use
ADDUSER add client access control entry
CONFIG send configuration parameter setting to server
DELMODEM deconfigure/remove modem
DELUSER remove client access control entry
TRIGGER register realtime 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 imple-
mented.
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 transfer, pre-
ceded by a Telnet IP and Synch, transfer status will be
returned.
OLD CLIENT-SERVER PROTOCOL SUPPORT
If hfaxd is started with the -o option it will service
clients using the old HylaFAX client-server protocol that
was used in distributions prior to the 4.0 release. Note
however that this support is only available if hfaxd is
compiled with the support enabled.
Emulation of the old protocol is important for supporting
non-UNIX clients such as the WinFlex client for Windows
systems and the MacFlex client for Macintosh systems. It
is strongly recommended however that unless you need to
support these old-style clients that you not enable sup-
port for the old protocol because of the inherent misde-
sign of this protocol.
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 are non-
standard extensions to RFC 1861 that may be added to SNPP
at some future time. Case is not distinguished and only
the first four characters of requests are used in identi-
fying commands.
Request Description
2WAY preface a 2-way transaction
ABOR 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 diable 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)
SITE site-specific commands (see next section)
STAT return server status
SUBJ set the message text for subsequent requests
The hfaxd server will abort an active SEND operation when
an ABOR command is preceded by a Telnet "Interrupt Pro-
cess" (IP) signal and a Telnet "Synch" signal in the com-
mand 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 CONTROL
hfaxd controls client access according to the information
in the file etc/hosts. 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(5F) for informa-
tion on the format and content of this file. The SITE
ADDUSER protocol request is provided for adding new users
to a server (available only to clients with administrative
privileges).
Server resources are controlled based on clients' identi-
ties. Jobs and documents, both received and submitted,
are protected by the server. Typically clients are per-
mitted 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; ${SPOOLDIR}. This is done so
that clients see a virtual file hierarchy that is com-
pletely contained within the HylaFAX operating environment
on the server machine. Administrators however must be
aware of this action when specifying files in the hfaxd
configuration file: absolute pathnames relative to the
root of the spooling should be used to specify filenames.
SERVER ACCESS CONTROL
The file 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 administrative 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. Con-
sult shutdown(5F) for information on the format and con-
tent of this file.
The SHUT protocol request can be used to schedule a server
shutdown; it is available only to clients with administra-
tive privileges. To make a shutdown server available
again the shutdown file can be deleted with the DELE pro-
tocol request (this is to be replaced with an ``unshut''
protocol request so that implementation details are not
part of the protocol).
CONFIGURATION FILES
hfaxd reads configuration information from the file
/usr/local/lib/fax/hfaxd.conf each time a new server pro-
cess is started (i.e. for each new client). This file
uses the same conventions used by other HylaFAX configura-
tion files; as described in config(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
KillTimeMap string see below mapping from service level to job kill time (SNPP)
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 /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
RetryTimeMap string see below mapping from service level to job retry time (SNPP)
ServerTracing integer 1 server tracing control vector
ShutdownFile string /etc/shutdown name of shutdown control file
UserAccessFile string /etc/hosts name of access control file
XferLogFile string /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 con-
tact in the help text returned to a client in
response to the HELP or SITE HELP commands. By
default this is ``FaxMaster@hostname'', 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 information with the LIST and STAT com-
mands. Formats are specified using printf(3S)
style conventions but using the field identi-
fiers 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 MaxIdleTime-
out; privileged clients may set the timeout to
any value.
JobFmt The format string to use when returning job sta-
tus information 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)
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 applica-
tions, such as faxstat(1) that construct headers
from the format string can constrain the width
of column title strings.
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 minutes 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 min-
utes for level four, etc.
LogFacility
The symbolic name for the syslog(3) facility to
use when logging error messages and informa-
tional/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
adminstrative privileges with the ADMIN command
that hfaxd will permit a client before terminat-
ing the connection. Note that the count of
attempts is reset if/when the client success-
fully gains administrative privileges.
MaxConsecutiveBadCmds
The maximum number of consecutive unrecognized,
unimplemented, syntactically incorrect, or oth-
erwise unacceptable commands to permit a client
before terminating the connection. This control
has two purposes: to handle naive or malicious
clients from sending long streams of nonsense
commands to a server, and to insure 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 con-
nection.
MaxMsgLength
The maximum number of characters to accept in a
pager message specified with the DATA or CESS
commands. Messages longer than this value are
rejected.
ModemFmt The format string to use when returning modem
status information for modems listed in the sta-
tus 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-justified, 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
content of this file. (Note that absolute path-
names are relative 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-separate 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 pri-
ority 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
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 faxs-
tat(1) that construct headers from the format
string can constrain the width of column title
strings.
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 algo-
rithm 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 sec-
ond delay, levels 1 and 2 after 60 seconds,
level 3 after 3 minutes, and other jobs are
retried according to the usual scheduling algo-
rithm.
ServerTracing
A number that controls the generation of tracing
information by a server. areas that are indi-
vidually controlled. To enable tracing of mul-
tiple areas of operation, the flag associated
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 con-
figuration parameter. Note that syslogd(8C)
must be configured to capture facility.info,
facility.debug, facility.warning, and facil-
ity.err messages.
ShutdownFile
The absolute pathname of the server shutdown
file; see shutdown(5F) for information on the
format and content of this file. (Note that
absolute pathnames are relative to the root of
the spooling area).
UserAccessFile
The absolute pathname of the user access control
file; see hosts(5F) for information on the for-
mat and content of this file. (Note that abso-
lute 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 spool-
ing area. The default spooling area,
/var/spool/fax, is defined at the time the soft-
ware is built.
-d Stop hfaxd from detaching itself from the con-
trolling terminal. This option is normally used
only when running hfaxd under a debugger or when
hfaxd is started up from the inetd(8C) process.
-i port Listen on the specified port for service
requests and respond with the (new) client-
server protocol. The port may be specified
either symbolically, e.g. ``hylafax'' or numeri-
cally. This flag may be specified multiple
times to request service on multiple different
ports.
-o port Listen on the specified port for service
requests and respond with the old client-server
protocol. The port may be specified either sym-
bolically, e.g. ``fax'' 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 speci-
fied either symbolically, e.g. ``snpp'' or
numerically. This flag may be specified multi-
ple times to request service on multiple differ-
ent ports.
-I Service the (new) client-server protocol using
the standard input and output. This option is
useful when hfaxd is started up by inetd(8C).
-O Service the old client-server protocol using the
standard input and output. This option is use-
ful when hfaxd is started up by inetd(8C).
-S Service the Simple Network Paging (SNPP) proto-
col 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/local/lib/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 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 ALSO
sendfax(1) sendpage(1) faxalter(1) faxrm(1) faxs-
tat(1) faxq(8C) syslog(3) hylafax(5F) hosts(5F) sta-
tus(5F) shutdown(5F)