blocklistd.conf(5) - NetBSD Manual Pages

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BLOCKLISTD.CONF(5)        NetBSD File Formats Manual        BLOCKLISTD.CONF(5)


NAME

     blocklistd.conf -- configuration file format for blocklistd


DESCRIPTION

     The blocklistd.conf file contains configuration entries for blocklistd(8)
     in a fashion similar to inetd.conf(5).  Only one entry per line is per-
     mitted.  Every entry must have all fields populated.  Each field can be
     separated by a tab or a space.  Comments are denoted by a ``#'' at the
     beginning of a line.

     There are two kinds of configuration lines, [local] and [remote].  By
     default, configuration lines are [local], i.e. the address specified
     refers to the addresses on the local machine.  To switch to between
     [local] and [remote] configuration lines you can specify the stanzas:
     ``[local]'' and ``[remote]''.

     On [local] and [remote] lines ``*'' means use the default, or wildcard
     match.  In addition, for [remote] lines ``='' means use the values from
     the matched [local] configuration line.

     The first four fields, location, type, proto, and owner are used to match
     the [local] or [remote] addresses, whereas the last 3 fields name, nfail,
     and disable are used to modify the filtering action.

     The first field denotes the location as an address, mask, and port.  The
     syntax for the location is:

                   [<address>|<interface>][/<mask>][:<port>]

     The address can be an IPv4 address in numeric format, an IPv6 address in
     numeric format and enclosed by square brackets, or an interface name.
     Mask modifiers are not allowed on interfaces because interfaces can have
     multiple addresses in different protocols where the mask has a different
     size.

     The mask is always numeric, but the port can be either numeric or sym-
     bolic.

     The second field is the socket type: stream, dgram, or numeric.  The
     third field is the protocol: tcp, udp, tcp6, udp6, or numeric.  The
     fourth field is the effective user (owner) of the daemon process report-
     ing the event, either as a username or a userid.

     The rest of the fields control the behavior of the filter.

     The name field, is the name of the packet filter rule to be used.  If the
     name starts with a hyphen (``-''), then the default rulename is prepended
     to the given name.  If the name contains a ``/'', the remaining portion
     of the name is interpreted as the mask to be applied to the address spec-
     ified in the rule, causing a single rule violation to block the entire
     subnet for the configured prefix.

     The nfail field contains the number of failed attempts before access is
     blocked, defaulting to ``*'' meaning never, and the last field duration
     specifies the amount of time since the last access that the blocking rule
     should be active, defaulting to ``*'' meaning forever.  The default unit
     for duration is seconds, but one can specify suffixes for different
     units, such as ``m'' for minutes ``h'' for hours and ``d'' for days.

     Matching is done first by checking the [local] rules individually, in the
     order of the most specific to the least specific.  If a match is found,
     then the matching [remote] rules are applied.  The name, nfail, and
     duration fields can be altered by the [remote] rule that matched.

     The [remote] rules can be used for allowing specific addresses, changing
     the mask size (via name), the rule that the packet filter uses (also via
     name), the number of failed attempts (via nfail), or the duration to
     block (via duration).


FILES

     /etc/blocklistd.conf  Configuration file.


EXAMPLES

             # Block ssh, after 3 attempts for 6 hours on the bnx0 interface
             [local]
             # location      type    proto   owner   name    nfail   duration
             bnx0:ssh        *       *       *       *       3       6h
             [remote]
             # Never block 1.2.3.4
             1.2.3.4:ssh     *       *       *       *       *       *
             # Never block the example IPv6 subnet either
             [2001:db8::]/32:ssh     *       *       *       *       *       *
             # For addresses coming from 8.8.0.0/16 block whole /24 networks instead
             # individual hosts, but keep the rest of the blocking parameters the same.
             8.8.0.0/16:ssh  *       *       *       /24     =       =


SEE ALSO

     blocklistctl(8), blocklistd(8)


HISTORY

     blocklistd.conf first appeared in NetBSD 7.  FreeBSD support for
     blocklistd.conf was implemented in FreeBSD 11.


AUTHORS

     Christos Zoulas

NetBSD 10.99                   February 5, 2025                   NetBSD 10.99