The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
From: Jesper Juhl <jesper.juhl@gmail.com>
This is the net/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in net/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Attached is kernel patch for UDP Fragmentation Offload (UFO) feature.
1. This patch incorporate the review comments by Jeff Garzik.
2. Renamed USO as UFO (UDP Fragmentation Offload)
3. udp sendfile support with UFO
This patches uses scatter-gather feature of skb to generate large UDP
datagram. Below is a "how-to" on changes required in network device
driver to use the UFO interface.
UDP Fragmentation Offload (UFO) Interface:
-------------------------------------------
UFO is a feature wherein the Linux kernel network stack will offload the
IP fragmentation functionality of large UDP datagram to hardware. This
will reduce the overhead of stack in fragmenting the large UDP datagram to
MTU sized packets
1) Drivers indicate their capability of UFO using
dev->features |= NETIF_F_UFO | NETIF_F_HW_CSUM | NETIF_F_SG
NETIF_F_HW_CSUM is required for UFO over ipv6.
2) UFO packet will be submitted for transmission using driver xmit routine.
UFO packet will have a non-zero value for
"skb_shinfo(skb)->ufo_size"
skb_shinfo(skb)->ufo_size will indicate the length of data part in each IP
fragment going out of the adapter after IP fragmentation by hardware.
skb->data will contain MAC/IP/UDP header and skb_shinfo(skb)->frags[]
contains the data payload. The skb->ip_summed will be set to CHECKSUM_HW
indicating that hardware has to do checksum calculation. Hardware should
compute the UDP checksum of complete datagram and also ip header checksum of
each fragmented IP packet.
For IPV6 the UFO provides the fragment identification-id in
skb_shinfo(skb)->ip6_frag_id. The adapter should use this ID for generating
IPv6 fragments.
Signed-off-by: Ananda Raju <ananda.raju@neterion.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (forwarded)
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Based on patch from David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Take account of whether a socket is bound to a particular device when
selecting an IPv6 raw socket to receive a packet. Also perform this
check when receiving IPv6 packets with router alert options.
Signed-off-by: Andrew McDonald <andrew@mcdonald.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Netfilter cleanup
- Move ipv4 code from net/core/netfilter.c to net/ipv4/netfilter.c
- Move ipv6 netfilter code from net/ipv6/ip6_output.c to net/ipv6/netfilter.c
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller. I did some basic
testing on my notebook and it seems to work.
The only real in-tree user of nfcache was IPVS, who only needs a
single bit. Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them. Maybe the IPVS guys can resolve that to further save space.
Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(
The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.
- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
compile-conditional skb->ipvs_property field. IPVS maintainers can
decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
turn many #if $undefined_string into #ifdef $undefined_string to fix some
warnings after -Wno-def was added to global CFLAGS
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Having frag_list members which holds wmem of an sk leads to nightmares
with partially cloned frag skb's. The reason is that once you unleash
a skb with a frag_list that has individual sk ownerships into the stack
you can never undo those ownerships safely as they may have been cloned
by things like netfilter. Since we have to undo them in order to make
skb_linearize happy this approach leads to a dead-end.
So let's go the other way and make this an invariant:
For any skb on a frag_list, skb->sk must be NULL.
That is, the socket ownership always belongs to the head skb.
It turns out that the implementation is actually pretty simple.
The above invariant is actually violated in the following patch
for a short duration inside ip_fragment. This is OK because the
offending frag_list member is either destroyed at the end of the
slow path without being sent anywhere, or it is detached from
the frag_list before being sent.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
While looking at this problem I noticed that IPv6 was sometimes
looking at inet->recverr which is bogus. Here is a patch to
correct that and use np->recverr.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!