A library to create Linux TUN/TAP interfaces
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.
defstruct lolevel socket
- (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 tun) procedure
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-name) procedure
returns the name of the TUN/TAP interface. Available after running make-tun
- (tun-mac tun) procedure
returns the MAC address associated with a TUN or TAP interface as a list of 6 integers
(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
;; 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.
0.1 alpha release