Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Add basic usage instructions to Documentation/networking.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

The TPROXY target implements redirection of non-local TCP/UDP traffic to local
sockets. Additionally, it's possible to manipulate the packet mark if and only
if a socket has been found. (We need this because we cannot use multiple
targets in the same iptables rule.)
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Add iptables 'socket' match, which matches packets for which a TCP/UDP
socket lookup succeeds.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

The iptables tproxy core is a module that contains the common routines used by
various tproxy related modules (TPROXY target and socket match)
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Netfilter connection tracking requires all IPv4 packets to be defragmented.
Both the socket match and the TPROXY target depend on this functionality, so
this patch separates the Netfilter IPv4 defrag hooks into a separate module.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

From kernel perspective, allow entrance in nf_hook_slow().

Stuff which uses nf_register_hook/nf_register_hooks, but otherwise not netns-ready:

	DECnet netfilter
	ipt_CLUSTERIP
	nf_nat_standalone.c together with XFRM (?)
	IPVS
	several individual match modules (like hashlimit)
	ctnetlink
	NOTRACK
	all sorts of queueing and reporting to userspace
	L3 and L4 protocol sysctls, bridge sysctls
	probably something else

Anyway critical mass has been achieved, there is no reason to hide netfilter any longer.

From userspace perspective, allow to manipulate all sorts of
iptables/ip6tables/arptables rules.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Same story as with iptable_filter, iptables_raw tables.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

First, allow entry in notifier hook.
Second, start conntrack cleanup in netns to which netdevice belongs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

* make keymap list per-netns
* per-netns keymal lock (not strictly necessary)
* flush keymap at netns stop and module unload.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Add init_net checks to not remove kmem_caches twice and so on.

Refactor functions to split code which should be executed only for
init_net into one place.

ip_ct_attach and ip_ct_destroy assignments remain separate, because
they're separate stages in setup and teardown.

NOTE: NOTRACK code is in for-every-net part. It will be made per-netns
after we decidce how to do it correctly.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Note, sysctl table is always duplicated, this is simpler and less
special-cased.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Show correct conntrack count, while I'm at it.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Heh, last minute proof-reading of this patch made me think,
that this is actually unneeded, simply because "ct" pointers will be
different for different conntracks in different netns, just like they
are different in one netns.

Not so sure anymore.

[Patrick: pointers will be different, flushing can only be done while
 inactive though and thus it needs to be per netns]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

This is cleaner, we already know conntrack to which event is relevant.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Conntrack code will use it for
a) removing expectations and helpers when corresponding module is removed, and
b) removing conntracks when L3 protocol conntrack module is removed.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

netfilter: netns nf_conntrack: per-netns /proc/net/ip_conntrack, /proc/net/stat/ip_conntrack, /proc/net/ip_conntrack_expect
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Again, it's deducible from skb, but we're going to use it for
nf_conntrack_checksum and statistics, so just pass it from upper layer.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

It's deducible from skb->dev or skb->dst->dev, but we know netns at
the moment of call, so pass it down and use for finding and creating
conntracks.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

What is confirmed connection in one netns can very well be unconfirmed
in another one.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Make per-netns a) expectation hash and b) expectations count.

Expectations always belongs to netns to which it's master conntrack belong.
This is natural and doesn't bloat expectation.

Proc files and leaf users are stubbed to init_net, this is temporary.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Take netns from skb->dst->dev. It should be safe because, they are called
from LOCAL_OUT hook where dst is valid (though, I'm not exactly sure about
IPVS and queueing packets to userspace).

[Patrick: its safe everywhere since they already expect skb->dst to be set]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

* make per-netns conntrack hash

  Other solution is to add ->ct_net pointer to tuplehashes and still has one
  hash, I tried that it's ugly and requires more code deep down in protocol
  modules et al.

* propagate netns pointer to where needed, e. g. to conntrack iterators.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Sysctls and proc files are stubbed to init_net's one. This is temporary.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Conntrack (struct nf_conn) gets pointer to netns: ->ct_net -- netns in which
it was created. It comes from netdevice.

->ct_net is write-once field.

Every conntrack in system has ->ct_net initialized, no exceptions.

->ct_net doesn't pin netns: conntracks are recycled after timeouts and
pinning background traffic will prevent netns from even starting shutdown
sequence.

Right now every conntrack is created in init_net.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

One comment: #ifdefs around #include is necessary to overcome amazing compile
breakages in NOTRACK-in-netns patch (see below).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>