This is automatically generated documentation. Edit after the "COMMENTS" heading; changes to the main body will be lost.

ToDevice.b Element Documentation


ToDevice.b -- Click element; sends packets to network device (BSD kernel)



Ports: 1 input, no outputs
Processing: pull
Drivers: bsdmodule
Package: bsdmodule (core)


This manual page describes the FreeBSD kernel module version of the ToDevice element. For the user-level element, read the ToDevice.u manual page. Pulls packets from its single input and sends them out the FreeBSD network interface named DEVNAME. DEVNAME may also be an Ethernet address, in which case ToDevice searches for a device with that address. Sends up to BURST packets each time it is scheduled. By default, BURST is 16. For good performance, you should set BURST to be 8 times the number of elements that could generate packets for this device. Packets must have a link header. For Ethernet, ToDevice makes sure every packet is at least 60 bytes long. Keyword arguments are:

Unsigned integer. Same as the BURST argument.
Allow nonexistent devices. If true, and no device named DEVNAME exists when the router is initialized, then ToDevice will report a warning (rather than an error). Later, while the router is running, if a device named DEVNAME appears, ToDevice will seamlessly begin sending packets to it. Default is false.


The FreeBSD networking code may also send packets out the device. Click won't see those packets. Worse, FreeBSD may cause the device to be busy when a ToDevice wants to send a packet. Click is not clever enough to re-queue such packets, and discards them. ToDevice's depend on the net driver's send operation for synchronization


packets (read-only)
Returns the number of packets ToDevice has pulled.
reset_counts (write-only)
Resets packets counter to zero when written.


FromDevice, FromHost, ToHost, ToDevice.u

Generated by 'click-elem2man' from '../elements/bsdmodule/todevice.hh' on 7/Mar/2009.


elements/todevice.b.txt · Last modified: 2009/03/07 17:24 (external edit)
Recent changes RSS feed Driven by DokuWiki