chickadee » tun

tun

Description

A library to create Linux TUN/TAP interfaces

Current status

The library currently allows the opening of a TUN/TAP interface in either TUN or TAP mode and keeps track of the interface name and its file descriptor. It provides two utility functions tun-up! and tun-mac which bring the interface up and return the interface MAC address respectively.

Note: the library assumes the presence of the "/dev/net/tun" device file. See https://www.kernel.org/doc/Documentation/networking/tuntap.txt.

Author

Omar Shorbaji

Requirements

defstruct lolevel socket

API

make-tun #!optional (mode 'tun) (pi #f)procedure

returns a tun/tap interface. The mode argument can be 'tun for a tunnel interface or 'tap for a tap interface. When the argument pi is #t we do not send the IFF_NO_PI flag and the interface includes packet information (four bytes) when reading every packet or frame

tun-fd tunprocedure

returns the file descriptor associated with the tunnel interface. Writing to this file descriptor sends data out of the interface. Note that written data must be well-formed packet (for tun) or ethernet frame (for tap).

tun-nameprocedure

returns the name of the TUN/TAP interface. Available after running make-tun

tun-mac tunprocedure

returns the MAC address associated with a TUN or TAP interface as a list of 6 integers

Examples

(define tap (make-tun 'tap)) ; creates a TUN/TAP interface in tap mode

(tun-up! tun)                ; brings interface up

(print "MAC address: " (tun-mac tap))

(use posix ethernet)

(let* ((pr (file-read fd size))
       (buf (car pr))
       (n (cadr pr)))
  (with-input-from-string (string-take buf n)
     (read-ethernet-frame))) ; reads an ethernet frame from TAP interface
  

Repository

https://github.com/shorbaji/chicken-tun

License

;; Copyright (c) 2016, Omar Shorbaji
;; All rights reserved.
;; 
;; 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 the author 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 THE COPYRIGHT HOLDERS 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 THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
;; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
;; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OFcl
;; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
;; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
;; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
;; POSSIBILITY OF SUCH DAMAGE.

Version History

0.1 alpha release

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