linux.git/include/linux/netfilter_ipv6.h, branch v6.1

netfilter: use actual socket sk rather than skb sk when routing harder

2020-10-30T11:57:39+00:00

If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():

   /* Note: skb->sk can be different from sk, in case of tunnels */
   int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,

That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.

One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.

So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: avoid ipv6 -> nf_defrag_ipv6 module dependency

2020-08-13T02:16:15+00:00

nf_ct_frag6_gather is part of nf_defrag_ipv6.ko, not ipv6 core.

The current use of the netfilter ipv6 stub indirections  causes a module
dependency between ipv6 and nf_defrag_ipv6.

This prevents nf_defrag_ipv6 module from being removed because ipv6 can't
be unloaded.

Remove the indirection and always use a direct call.  This creates a
depency from nf_conntrack_bridge to nf_defrag_ipv6 instead:

modinfo nf_conntrack
depends:        nf_conntrack,nf_defrag_ipv6,bridge

.. and nf_conntrack already depends on nf_defrag_ipv6 anyway.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: move nf_bridge_frag_data struct definition to a more appropriate header.

2019-09-13T10:35:33+00:00

There is a struct definition function in nf_conntrack_bridge.h which is
not specific to conntrack and is used elswhere in netfilter.  Move it
into netfilter_bridge.h.

Signed-off-by: Jeremy Sowden 
Signed-off-by: Pablo Neira Ayuso

netfilter: move inline nf_ip6_ext_hdr() function to a more appropriate header.

2019-09-13T10:34:09+00:00

There is an inline function in ip6_tables.h which is not specific to
ip6tables and is used elswhere in netfilter.  Move it into
netfilter_ipv6.h and update the callers.

Signed-off-by: Jeremy Sowden 
Signed-off-by: Pablo Neira Ayuso

netfilter: fix coding-style errors.

2019-09-13T09:39:38+00:00

Several header-files, Kconfig files and Makefiles have trailing
white-space.  Remove it.

In netfilter/Kconfig, indent the type of CONFIG_NETFILTER_NETLINK_ACCT
correctly.

There are semicolons at the end of two function definitions in
include/net/netfilter/nf_conntrack_acct.h and
include/net/netfilter/nf_conntrack_ecache.h. Remove them.

Fix indentation in nf_conntrack_l4proto.h.

Signed-off-by: Jeremy Sowden 
Signed-off-by: Pablo Neira Ayuso

netfilter: fix nf_conntrack_bridge/ipv6 link error

2019-06-21T15:21:11+00:00

When CONFIG_IPV6 is disabled, the bridge netfilter code
produces a link error:

ERROR: "br_ip6_fragment" [net/bridge/netfilter/nf_conntrack_bridge.ko] undefined!
ERROR: "nf_ct_frag6_gather" [net/bridge/netfilter/nf_conntrack_bridge.ko] undefined!

The problem is that it assumes that whenever IPV6 is not a loadable
module, we can call the functions direction. This is clearly
not true when IPV6 is disabled.

There are two other functions defined like this in linux/netfilter_ipv6.h,
so change them all the same way.

Fixes: 764dd163ac92 ("netfilter: nf_conntrack_bridge: add support for IPv6")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Pablo Neira Ayuso

netfilter: synproxy: fix building syncookie calls

2019-06-20T09:59:36+00:00

When either CONFIG_IPV6 or CONFIG_SYN_COOKIES are disabled, the kernel
fails to build:

include/linux/netfilter_ipv6.h:180:9: error: implicit declaration of function '__cookie_v6_init_sequence'
      [-Werror,-Wimplicit-function-declaration]
        return __cookie_v6_init_sequence(iph, th, mssp);
include/linux/netfilter_ipv6.h:194:9: error: implicit declaration of function '__cookie_v6_check'
      [-Werror,-Wimplicit-function-declaration]
        return __cookie_v6_check(iph, th, cookie);
net/ipv6/netfilter.c:237:26: error: use of undeclared identifier '__cookie_v6_init_sequence'; did you mean 'cookie_init_sequence'?
net/ipv6/netfilter.c:238:21: error: use of undeclared identifier '__cookie_v6_check'; did you mean '__cookie_v4_check'?

Fix the IS_ENABLED() checks to match the function declaration
and definitions for these.

Fixes: 3006a5224f15 ("netfilter: synproxy: remove module dependency on IPv6 SYNPROXY")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Pablo Neira Ayuso

netfilter: synproxy: remove module dependency on IPv6 SYNPROXY

2019-06-17T15:12:09+00:00

This is a prerequisite for the infrastructure module NETFILTER_SYNPROXY.
The new module is needed to avoid duplicated code for the SYNPROXY
nftables support.

Signed-off-by: Fernando Fernandez Mancera 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_conntrack_bridge: fix CONFIG_IPV6=y

2019-05-31T16:45:26+00:00

This patch fixes a few problems with CONFIG_IPV6=y and
CONFIG_NF_CONNTRACK_BRIDGE=m:

In file included from net/netfilter/utils.c:5:
include/linux/netfilter_ipv6.h: In function 'nf_ipv6_br_defrag':
include/linux/netfilter_ipv6.h:110:9: error: implicit declaration of function 'nf_ct_frag6_gather'; did you mean 'nf_ct_attach'? [-Werror=implicit-function-declaration]

And these too:

net/ipv6/netfilter.c:242:2: error: unknown field 'br_defrag' specified in initializer
net/ipv6/netfilter.c:243:2: error: unknown field 'br_fragment' specified in initializer

This patch includes an original chunk from wenxu.

Fixes: 764dd163ac92 ("netfilter: nf_conntrack_bridge: add support for IPv6")
Reported-by: Stephen Rothwell 
Reported-by: Yuehaibing 
Reported-by: kbuild test robot 
Reported-by: wenxu 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: wenxu 
Signed-off-by: David S. Miller

netfilter: nf_conntrack_bridge: add support for IPv6

2019-05-30T21:18:18+00:00

br_defrag() and br_fragment() indirections are added in case that IPv6
support comes as a module, to avoid pulling innecessary dependencies in.

The new fraglist iterator and fragment transformer APIs are used to
implement the refragmentation code.

Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: David S. Miller