When you've enabled conntrack and NAT as a module (standard case in all
distributions), and you've also enabled the new conntrack netlink
interface, loading ip_conntrack_netlink.ko will auto-load iptable_nat.ko.
This causes a huge performance penalty, since for every packet you iterate
the nat code, even if you don't want it.
This patch splits iptable_nat.ko into the NAT core (ip_nat.ko) and the
iptables frontend (iptable_nat.ko). Threfore, ip_conntrack_netlink.ko will
only pull ip_nat.ko, but not the frontend. ip_nat.ko will "only" allocate
some resources, but not affect runtime performance.
This separation is also a nice step in anticipation of new packet filters
(nf-hipac, ipset, pkttables) being able to use the NAT core.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the NAT module is loaded when connections are already confirmed
it must not change their tuples anymore. This is especially important
with CONFIG_NETFILTER_DEBUG, the netfilter listhelp functions will
refuse to remove an entry from a list when it can not be found on
the list, so when a changed tuple hashes to a new bucket the entry
is kept in the list until and after the conntrack is freed.
Allocate the exact conntrack tuple for NAT for already confirmed
connections or drop them if that fails.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ctnetlink subsystem for userspace-access to ip_conntrack table.
This allows reading and updating of existing entries, as well as
creating new ones (and new expect's) via nfnetlink.
Please note the 'strange' byte order: nfattr (tag+length) are in host
byte order, while the payload is always guaranteed to be in network
byte order. This allows a simple userspace process to encapsulate netlink
messages into arch-independent udp packets by just processing/swapping the
headers and not knowing anything about the actual payload.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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>
With the introduction of 'rustynat' in 2.6.11, the old tricks of preventing
NAT of 'untracked' connections (e.g. NOTRACK target in 'raw' table) are no
longer sufficient.
The ip_conntrack_untracked.status |= IPS_NAT_DONE_MASK effectively
prevents iteration of the 'nat' table, but doesn't prevent nat_packet()
to be executed. Since nr_manips is gone in 'rustynat', nat_packet() now
implicitly thinks that it has to do NAT on the packet.
This patch fixes that problem by explicitly checking for
ip_conntrack_untracked in ip_nat_fn().
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The NAT changes in 2.6.11 changed the position where helpers
are called and perform packet mangling. Before 2.6.11, a NAT
helper was called before the packet was NATed and had its
sequence number adjusted. Since 2.6.11, the helpers get packets
with already adjusted sequence numbers.
This breaks sequence number adjustment, adjust_tcp_sequence()
needs the original sequence number to determine whether
a packet was a retransmission and to store it for further
corrections. It can't be reconstructed without more information
than available, so this patch restores the old order by
calling helpers from a new conntrack hook two priorities
below ip_conntrack_confirm() and adjusting the sequence number
from a new NAT hook one priority below ip_conntrack_confirm().
Tracked down by Phil Oester <kernel@linuxace.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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!
