twx-linux/include
Max Krasnyansky f271b2cc78 tun: Fix/rewrite packet filtering logic
Please see the following thread to get some context on this
	http://marc.info/?l=linux-netdev&m=121564433018903&w=2

Basically the issue is that current multi-cast filtering stuff in
the TUN/TAP driver is seriously broken.
Original patch went in without proper review and ACK. It was broken and
confusing to start with and subsequent patches broke it completely.
To give you an idea of what's broken here are some of the issues:

- Very confusing comments throughout the code that imply that the
character device is a network interface in its own right, and that packets
are passed between the two nics. Which is completely wrong.

- Wrong set of ioctls is used for setting up filters. They look like
shortcuts for manipulating state of the tun/tap network interface but
in reality manipulate the state of the TX filter.

- ioctls that were originally used for setting address of the the TX filter
got "fixed" and now set the address of the network interface itself. Which
made filter totaly useless.

- Filtering is done too late. Instead of filtering early on, to avoid
unnecessary wakeups, filtering is done in the read() call.

The list goes on and on :)

So the patch cleans all that up. It introduces simple and clean interface for
setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering
before enqueuing the packets.

TX filtering is useful in the scenarios where TAP is part of a bridge, in
which case it gets all broadcast, multicast and potentially other packets when
the bridge is learning. So for example Ethernet tunnelling app may want to
setup TX filters to avoid tunnelling multicast traffic. QEMU and other
hypervisors can push RX filtering that is currently done in the guest into the
host context therefore saving wakeups and unnecessary data transfer.

Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-14 22:18:19 -07:00
..
acpi
asm-alpha alpha: fix compile error in arch/alpha/mm/init.c 2008-06-23 18:26:04 -07:00
asm-arm [ARM] 5091/1: Add missing bitfield include to regs-lcd.h 2008-06-12 20:49:38 +01:00
asm-avr32
asm-blackfin Blackfin Serial Driver: Use timer to poll CTS PIN instead of workqueue. 2008-06-19 17:46:39 +08:00
asm-cris
asm-frv
asm-generic kbuild: fix a.out.h export to userspace with O= build. 2008-06-27 23:13:54 +02:00
asm-h8300
asm-ia64 [IA64] Fix CONFIG_IA64_SGI_UV build error 2008-06-16 09:02:03 -07:00
asm-m32r
asm-m68k m68k: Add ext2_find_{first,next}_bit() for ext4 2008-06-12 18:05:39 -07:00
asm-m68knommu
asm-mips [MIPS] Malta: Fix build errors for 64-bit kernels 2008-06-16 15:14:48 +01:00
asm-mn10300
asm-parisc parisc: fix miscompilation of ip_fast_csum with gcc >= 4.3 2008-06-13 10:49:56 -04:00
asm-powerpc kbuild: fix a.out.h export to userspace with O= build. 2008-06-27 23:13:54 +02:00
asm-ppc
asm-s390
asm-sh
asm-sparc
asm-sparc64
asm-um
asm-v850
asm-x86 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-06-30 08:56:57 -07:00
asm-xtensa
crypto
keys
linux tun: Fix/rewrite packet filtering logic 2008-07-14 22:18:19 -07:00
math-emu
media V4L/DVB (8092): videodev: simplify and fix standard enumeration 2008-06-26 15:58:57 -03:00
mtd
net Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 2008-07-14 20:40:34 -07:00
pcmcia
rdma
rxrpc
scsi
sound
video
xen x86: Make xen use the paravirt clocksource structs and functions 2008-06-24 21:02:32 +03:00
Kbuild