before adding/removing packets from the queue. Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.
IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue. An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.
Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.
Now most big problem of IPv6 is getting IPv6 address
assignment.
6to4 solve the problem. 6to4 addr is defined like below,
2002: 4byte v4 addr : 2byte SLA ID : 8byte interface ID
The most important point of the address format is that an IPv4 addr
is embeded in it. So any user who has IPv4 addr can get IPv6 address
block with 2byte subnet space. Also, the IPv4 addr is used for
semi-automatic IPv6 over IPv4 tunneling.
With 6to4, getting IPv6 addr become dramatically easy.
The attached patch enable 6to4 extension, and confirmed to work,
between "Richard Seaman, Jr." <dick@tar.com> and me.
Approved by: jkh
Reviewed by: itojun
packet divert at kernel for IPv6/IPv4 translater daemon
This includes queue related patch submitted by jburkhol@home.com.
Submitted by: queue related patch from jburkhol@home.com
Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project
