NAME

       nbdkit_peer_name, nbdkit_peer_pid, nbdkit_peer_uid, nbdkit_peer_gid, nbdkit_peer_security_context - get
       client address and information for nbdkit

SYNOPSIS

        #include <nbdkit-plugin.h>

        int nbdkit_peer_name (struct sockaddr *addr, socklen_t *addrlen);
        int64_t nbdkit_peer_pid (void);
        int64_t nbdkit_peer_uid (void);
        int64_t nbdkit_peer_gid (void);
        char *nbdkit_peer_security_context (void);

DESCRIPTION

   nbdkit_peer_name
       Return the peer (client) address, if available.  The "addr" and "addrlen" parameters behave like
       getpeername(2).  In particular you must initialize "addrlen" with the size of the buffer pointed to by
       "addr", and if "addr" is not large enough then the address will be truncated.

       In some cases this is not available or the address returned will be meaningless (eg. if there is a proxy
       between the client and nbdkit).  This call uses thread-local magic so no parameter is required to specify
       the current connection.

   nbdkit_peer_pid
       (nbdkit ≥ 1.24, Linux only)

       Return the peer process ID.  This is only available when the client connected over a Unix domain socket.

   nbdkit_peer_uid
       (nbdkit ≥ 1.24)

       Return the peer user ID.  This is only available when the client connected over a Unix domain socket.

   nbdkit_peer_gid
       (nbdkit ≥ 1.24)

       Return the peer group ID.  This is only available when the client connected over a Unix domain socket.

   nbdkit_peer_security_context
       (nbdkit ≥ 1.36, not Windows)

       Return the peer security context (usually the SELinux label, IPSEC label or NetLabel).  See the
       description of "SO_PEERSEC" in unix(7) and ip(7).

RETURN VALUE

       All functions except "nbdkit_peer_security_context" return 0 on success.  If there is an error they call
       nbdkit_error(3) and return -1.

       "nbdkit_peer_security_context" returns a security context as a string on success.  The caller must free
       this string.  On error (which can include missing label or unsupported protocol), nbdkit_error(3) is
       called and this call returns "NULL".

LANGUAGE BINDINGS

       In nbdkit-ocaml-plugin(3):

        NBDKit.peer_name : unit -> Unix.sockaddr
        NBDKit.peer_pid : unit -> int64
        NBDKit.peer_uid : unit -> int64
        NBDKit.peer_gid : unit -> int64
        NBDKit.peer_security_context : unit -> string

       In nbdkit-python-plugin(3):

        import nbdkit
        pid = nbdkit.peer_pid()
        uid = nbdkit.peer_uid()
        gid = nbdkit.peer_gid()
        security_context = nbdkit.peer_security_context()

       In nbdkit-rust-plugin(3):

        use nbdkit::*;
        pub fn peername<T: SockaddrLike>() ->
                std::result::Result<T, Box<dyn error::Error>>

HISTORY

       "nbdkit_peer_name" was added in nbdkit 1.16.

       "nbdkit_peer_pid", "nbdkit_peer_uid" and "nbdkit_peer_gid" were added in nbdkit 1.24.

       "nbdkit_peer_security_context" was added in nbdkit 1.36.

SEE ALSO

       nbdkit(1), nbdkit-plugin(3), nbdkit-filter(3), nbdkit-ip-filter(1), getpeername(2), unix(7), ip(7).

AUTHORS

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

       Redistribution and use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

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

       •   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
           the following disclaimer in the documentation and/or other materials provided with the distribution.

       •   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.

       THIS  SOFTWARE  IS  PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND  FITNESS  FOR  A  PARTICULAR
       PURPOSE  ARE  DISCLAIMED.  IN  NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
       INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT  OF
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       DAMAGE.

nbdkit-1.42.2                                      2025-04-02                                nbdkit_peer_name(3)