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

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