nbdkit_peer_name(3)

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.

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