Well, I may have some more socket options in the future for the application to fill segments of the 20-byte tag, and the tag may be extended to 40 or 64 bytes, when OOB information increases.
How does IPSEC prepend the new header in tunnelling mode? Thanks. Haisang On 1/24/06, Chuck Swiger <[EMAIL PROTECTED]> wrote: > > Haisang Wu wrote: > > I am writing for help on my freebsd kernel hacking. I am working on > 4.10, > > and intend to introduct a new socket option (say, SO_TAG_PAK) > > for my own kernel. When sending out a packet, if this option is set, the > > socket layer will produce a 20-byte tag, and finally this tag will be > > prepended before IP header (may be done in ip_output() ). This is > somewhat > > like MPLS's shim layer, but this special packet with the tag will only > be > > sent over a logical tunnel to another system. When receiving a packet, > the > > IP layer will check whether the packet has this tag (through the > > first integer of the tag), and pass the tag up (to applications). > > If you want to write your own protocol which wraps IP, OK, but there are > easier > ways of passing out-of-band data to the application layer. > > Consider either setting up a new IP-layer option, a new TCP-layer option, > or > just using TCP's urgent pointer to send OOB data. Twenty bytes would fit > just > fine inside the existing protocols, and you would be able to take > advantage of > hardware support for Rx and Tx checksums, etc, etc. > > -- > -Chuck > _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"