On Wed, 24 Nov 1999 02:30:05 -0800 (PST) 
 Todd Whitesel <toddpw@best.com> wrote:

 > Every time I've tried to implement Internet code, I've given up on the
 > idea of elegantly portable code. Just trying to deal with strictly aligned
 > RISC chips and ethernet devices that put a 14-byte ethernet header on a
 > word boundary (forcing the entire IP header to be non-word-aligned), is
 > enough to make me wonder how anyone can write elegantly portable Internet
 > code without quite a few abstraction macros. (And before you ask, no I
 > haven't looked at netinet recently, I gave up on this a long time ago.)

Well, right now, NetBSD simple makes sure the Ethernet header itself is
*unaligned* (which is fine for the Ethernet header), which then ensures
that the IP header *is* aligned.

Matt Thomas has suggested a more clever method, involving changes to the
IP stack, and I've been thinking about a more clever method which could
be used in e.g. the `tlp' driver.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>