noble (1) nbdkit-ip-filter.1.gz

Provided by: nbdkit_1.36.3-1ubuntu10_amd64 bug

NAME
       nbdkit-ip-filter - filter clients by IP address, process ID, user ID or group ID


SYNOPSIS
        nbdkit --filter=ip PLUGIN [allow=addr[,addr...]]
                                  [deny=addr[,addr...]]


DESCRIPTION
       "nbdkit-ip-filter" can allow or deny client connections by their IP address.  Usually it is better to
       control this outside nbdkit, for example using TCP wrappers or a firewall, but this filter can be used if
       these are not available.

       nbdkit ≥ 1.24 added the ability to filter clients connecting over Unix domain sockets by client process
       ID, user ID and group ID.  Also this version added support for filtering "AF_VSOCK" sockets by peer CID
       or port.


EXAMPLES
   Filter by IP address
        nbdkit --filter=ip [...] allow=127.0.0.1,::1 deny=all

       Allow clients to connect on the loopback IPv4 or loopback IPv6 address, deny all other clients.

        nbdkit --filter=ip [...] deny=8.0.0.0/8

       Allow any client except connections from the IPv4 "8.0.0.0/8" network.

        nbdkit --filter=ip [...] allow=anyipv6 deny=all

       Allow IPv6 clients to connect from anywhere, deny all other sources.

   Filter by Unix domain socket peer
        nbdkit -U $tmpdir/sock --filter=ip [...] allow=uid:`id -u` deny=all

       Only allow the current user ("id -u") to connect over the socket.

       Layer extra security by creating the socket inside a temporary directory only accessible by the user.

        nbdkit -U $tmpdir/sock --filter=ip [...] allow=gid:`id -g` deny=all

       Allow anyone in the same group as the current user to connect to the Unix domain socket.

       As in the previous example, layer extra security by creating the socket inside a temporary directory only
       accessible by the group.


RULES
       When a client connects, this filter checks its source address against the allow and deny lists as
       follows:

       1.  If the address matches any in the allow list, permission is granted.

       2.  If the address matches any in the deny list, permission is denied.

       3.  Otherwise permission is granted.

       If either the "allow" or "deny" parameter is not present then it is assumed to be an empty list.  The
       order in which the parameters appear on the command line does not matter; the allow list is always
       processed first and the deny list second.

       The "allow" and "deny" parameters each contain a comma-separated list of any of the following:

       all
       any These keywords (which both have the same meaning) match any source.

       allipv4
       anyipv4
           These keywords match any IPv4 address.

       allipv6
       anyipv6
           These keywords match any IPv6 address.

       allunix
       anyunix
           These keywords match any connection over a Unix domain socket.

       allvsock
       anyvsock
           These keywords match any connection over an "AF_VSOCK" socket.

       A.B.C.D
           This matches the single IPv4 address "A.B.C.D", for example 127.0.0.1.

       A.B.C.D/NN
           This matches the range of IPv4 addresses "A.B.C.D/NN", for example "192.168.2.0/24" or "10.0.0.0/8".

       A:B:...
           This matches the single IPv6 address "A:B:...".  The usual IPv6 address representations can be used
           (see RFC 5952).

       A:B:.../NN
           This matches a range of IPv6 addresses "A:B:.../NN".

       pid:PID
           (nbdkit ≥ 1.24, Linux only)

           This matches the process ID "PID", if the client connects over a Unix domain socket.

           Note that process IDs are recycled so this alone is not secure enough to ensure that only a single
           desired process can connect.  However you could use it as an additional check.

       security:LABEL
           (nbdkit ≥ 1.36, not Windows)

           This matches the security context (usually the SELinux label, IPSEC label or NetLabel) of the client.

       uid:UID
           (nbdkit ≥ 1.24)

           This matches the numeric user ID "UID", if the client connects over a Unix domain socket.

       gid:GID
           (nbdkit ≥ 1.24)

           This matches the numeric group ID "GID", if the client connects over a Unix domain socket.

       vsock-cid:CID
       vsock-port:PORT
           (nbdkit ≥ 1.24)

           These match the CID or port number for "AF_VSOCK" sockets.

   Not filtered
       If neither the "allow" nor the "deny" parameter is given the filter does nothing.

       Unix domain sockets and "AF_VSOCK" sockets were always unfiltered in nbdkit ≤ 1.22.  In nbdkit ≥ 1.24 the
       ability to filter them was added.

   Common patterns of usage
       Permit known good connections and deny everything else:

        nbdkit --filter=ip ... allow=good1,good2,... deny=all

       Block troublemakers but allow everything else:

        nbdkit --filter=ip ... deny=bad1,bad2,...


PARAMETERS
       allow=addr[,...]
           Set list of allow rules.  This parameter is optional, if omitted the allow list is empty.

       deny=addr[,...]
           Set list of deny rules.  This parameter is optional, if omitted the deny list is empty.


DEBUG FLAGS
       -D ip.rules=1
           Debug rules and rule matching.  If clients are accepted or rejected when they should not be, using
           -v -D ip.rules=1 can help to debug the problem.


FILES
       $filterdir/nbdkit-ip-filter.so
           The filter.

           Use "nbdkit --dump-config" to find the location of $filterdir.


VERSION
       "nbdkit-ip-filter" first appeared in nbdkit 1.18.


SEE ALSO
       nbdkit(1), nbdkit-exitlast-filter(1), nbdkit-exitwhen-filter(1), nbdkit-limit-filter(1),
       nbdkit-filter(3).


AUTHORS
       Richard W.M. Jones


       Copyright Red Hat


LICENSE
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       that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list of conditions and
           the following disclaimer.

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       •   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote
           products derived from this software without specific prior written permission.

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       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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