Provided by: gnarwl_3.6.dfsg-13build1_amd64 
NAME
gnarwl - GNU Neat Autoreply With LDAP
SYNOPSIS
gnarwl [-h] [-c <cfgfile>] [-a <address>] [-s <address>]
DESCRIPTION
gnarwl is an email autoresponder, intended to be a successor to the old vaction(1)
program. Since a modern mailserver, usually serves hundreds (or even thousands) of
mailaccounts, it is not sensible to give (untrusted) users shell access so they may
create/maintain the .forward file, required by vacation(1).
With gnarwl , all user-suplied data is stored within an LDAP database, so there are no per
user ".forward" files (or even homedirs) needed. Configuration is conveniently done via
one systemwide configfile.
Like the old vacation(1) program, gnarwl accepts incoming mail through stdin, and will
send outgoing mail via an external MTA (it even maintains basic commandline compatibility,
so it may be used as a drop in replacement).
Several gdbm databases are maintained, in order to make sure, a) mail does not bounce back
and force between gnarwl and another automated MUA, b) mailing lists will not be bothered
and c) specific local addresses may never produce automatic replies. All these database
files may be managed using the damnit(8) program.
OPTIONS
-c <cfgfile>
Use a different configfile than the one, compiled in.
-a <alias>
Force <address> as receiving address.
-s <address>
Force <address> as sending address.
-h Print usage information.
CONFIGURATION
gnarwl typically uses one global configurationfile, but a per user setup is also possible
using the -c commandline switch. The following keywords are recognized in the configfile:
map_sender <macroname>
Binds a macroname (case insensitive), referring to the sender of an incoming email.
Defaults to "$sender".
map_receiver <macroname>
Binds a macroname (case insensitive), referring to the receiver(s) of an incoming
email. Defaults to "$receiver".
map_subject <macroname>
Binds a macroname (case insensitive), referring to the subject of an incoming
email. Defaults to "$subject".
map_field <ldapattribute> <macroname>
Binds a macroname (case insensitive), referring to a field in the resultset,
returned by the database. There are no defaults for this directive.
server_uri <ldap_uri [ldap_uri ...]>
URI of the databaseserver to query. Multiple URIs can be specified. No default
value.
starttls <0|1>
Enforce StartTLS on connect. Defaults to 0.
ca_cert </path/to/certificate>
Use specified CA cert to validate ldap server certificate. No default value.
server <address>
Address of the databaseserver to query. Defaults to localhost.
port <portnumber>
Port, the LDAP server listens on. Defaults to 389.
scope <base|one|sub>
The scope used for searching the database. Default is "sub".
login <string>
Destinguished name to bind with to the LDAP database. Default is to bind
anonymously.
password <string>
Password to use for binding to the LDAP database. If a password is required to
access the server, then the configfile should belong to the gnarwl user and have
file permission 0400.
base <destinguished name>
Entrypoint of the search. There is no default for this directive, it must be
supplied by the administrator.
protocol <2|3>
Select protocol to bind to the ldapserver. The default is 3.
queryfilter <ldap queryfilter>
Search pattern to match against the database. Defaults to:
"(&(mail=$recepient)(vacationActive=TRUE)".
result <ldap attribute>
The name of the attribute, that is to be taken as the emailbody. The content of
this field will be pasted in between the data found via forceheader and forcefooter
directives. Afterwards all remaining macros are expanded in the order of
declaration, and the result will be piped through to the MTA.
blockfiles <directory>
The directory, where gnarwl stores it's blockfiles. These files are required to
keep track on who was sent an automatic reply. Default is:
"/var/lib/gnarwl/block/".
umask <mode>
What permission to give newly generated database files. The default is 0600.
blockexpire <number>
How long (in hours) to block a certain sender/recepient combo. Default is 48 hours.
Setting <number> to 0 disables the feature (not recommended). No blockfiles are
read/written in this case.
maxreceivers <number>
Ignore incoming email, specifying too many receiving addresses. It does not matter,
whether these are local or not, as gnarwl doesn't know domains. Default is 256.
maxheader <number>
Ignore incoming email with more than this number of header lines. Lines are counted
before unfolding them, so a folded line really counts as at least two lines.
Default is 256.
badheaders <filename>
Path to a database file, containing matching patterns for the mailheader. If an
entry stored in this file matches a line in the header exactly, then this mail will
be ignored by gnarwl . (useful to avoid sending automatic replies to mailing
lists). This feature is deactivated by default.
blacklist <filename>
Pointer to a database file, containing emailaddresses, gnarwl is not allowed to
generate automatic replies for (useful to prevent automatic replies from addresses,
which are shared by several people). This feature is deactivated by default.
forceheader <filename>
Path to a text file, containing a standardized header, that is to be pasted in
front of every outgoing mail. This file should end with a single empty line.
Otherwise it is assumed, that the users are allowed to continue the header and will
provide the separating empty line themselves. Default is not to force anything
(that is: The user has to supply the header in the "result" attribute).
forcefooter <filename>
Path to a text file, containing a standardized footer, that is to be appended at
the end of every generated mail. Default is to not to force anything.
mta <prog> [<args>]
Specify MTA for sending mail. It must be able to accept mail on STDIN. Default is
"/usr/sbin/sendmail".
charset <encoding>
LDAP stores text in unicode, which is ok, as long as outgoing mail doesn't contain
any non ASCII characters. However, locale specific characters (like german umlaute)
end up as strange glyphs. With the "charset" directive, gnarwl tries to convert
these to the correct symbols. The <encoding> argument must contain a string
recognized by iconv(3). Default is not to try to convert anything (assume US-ASCII
charset / MIME encoded mail).
recvheader <string>
A whitespace separated list of headers (case does not matter), which may contain
receiving addresses. Defaults to: "To Cc".
loglevel <0|1|2|3>
Specifies what to send to the syslog. A higher loglevel automatically includes all
lower loglevels (see section syslog for more information).
deref <never|search|find|always>
Controls what LDAP alias dereferencing will be performed. Default is "find".
SYSLOG
Since gnarwl is not meant to be invoked by anything but the mailsystem, it'll never print
out messages to the systemconsole, but logs them via syslog(3), using the facility "mail".
A log line is always of the following format:
<level>/<origin> <message>
The <level> field indicates the severity of the message, it corresponds to the "loglevel"
config directive. Possible values are:
CRIT (loglevel 0)
Critical messages. gnarwl cannot continue and will die with a non-zero exit code.
This usually causes the mailsystem to bounce mail.
WARN (loglevel 1)
A warning. gnarwl can will continue, but not with the full/intended functionality.
INFO (loglevel 2)
Status information. A message in the INFO loglevel indicates normal behaviour.
DEBUG (loglevel 3)
Debugging information. gnarwl will log a lot of information on how mail is
processed.
The <origin> field gives a short hint about what caused the log entry in question, while
<message> contains a short description of what actually happened.
AUTHOR
Patrick Ahlbrecht <p.ahlbrecht@billiton.de>
SEE ALSO
vacation(1), postfix(1), iconv(1), damnit(8), rfc822
FILES
/etc/gnarwl.cfg
main configuration file.
/var/lib/gnarwl/.forward
forward file for the mailsystem.
/var/lib/gnarwl/blacklist.db
gnarwl won't send an autoreply for anyone whose emailaddress is listed herin.
/var/lib/gnarwl/badheaders.db
gnarwl will ignore mail, it is able to match a headerline with an entry in this
file. Case is significant, no wildcards are expanded.
/var/lib/gnarwl/header.txt
Standard header to paste in front of every outgoing mail.
/var/lib/gnarwl/footer.txt
Standard footer to append to every outgoing mail.
/var/lib/gnarwl/block/*
block files.
GNARWL(8)