The netfilter hook list never uses the prev pointer, and so can be trimmed to
be a simple singly-linked list.
In addition to having a more light weight structure for hook traversal,
struct net becomes 5568 bytes (down from 6400) and struct net_device becomes
2176 bytes (down from 2240).
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This replaces the last uses of NF_HOOK_THRESH().
Followup patch will remove it and rename nf_hook_thresh.
The reason is that inet (non-bridge) netfilter no longer invokes the
hooks from hooks, so we do no longer need the thresh value to skip hooks
with a lower priority.
The bridge netfilter however may need to do this. br_nf_hook_thresh is a
wrapper that is supposed to do this, i.e. only call hooks with a
priority that exceeds NF_BR_PRI_BRNF.
It's used only in the recursion cases of br_netfilter. It invokes
nf_hook_slow while holding an rcu read-side critical section to make a
future cleanup simpler.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip_skb_dst_mtu uses skb->sk, assuming it is an AF_INET socket (e.g. it
calls ip_sk_use_pmtu which casts sk as an inet_sk).
However, in the case of UDP tunneling, the skb->sk is not necessarily an
inet socket (could be AF_PACKET socket, or AF_UNSPEC if arriving from
tun/tap).
OTOH, the sk passed as an argument throughout IP stack's output path is
the one which is of PMTU interest:
- In case of local sockets, sk is same as skb->sk;
- In case of a udp tunnel, sk is the tunneling socket.
Fix, by passing ip_finish_output's sk to ip_skb_dst_mtu.
This augments 7026b1ddb6 'netfilter: Pass socket pointer down through okfn().'
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename IP_INC_STATS_BH() to __IP_INC_STATS(), to
better express this is used in non preemptible context.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This moves bridge hooks to a register-when-needed scheme.
We use a device notifier to register the 'call-iptables' netfilter hooks
only once a bridge gets added.
This means that if the initial namespace uses a bridge, newly created
network namespaces no longer get the PRE_ROUTING ipt_sabotage hook.
It will registered in that network namespace once a bridge is created
within that namespace.
A few modules still use global hooks:
- conntrack
- bridge PF_BRIDGE hooks
- IPVS
- CLUSTER match (deprecated)
- SYNPROXY
As long as these modules are not loaded/used, a new network namespace has
empty hook list and NF_HOOK() will boil down to single list_empty test even
if initial namespace does stateless packet filtering.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This merge resolves conflicts with 75aec9df3a ("bridge: Remove
br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve
netns support in the network stack that reached upstream via David's
net-next tree.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
net/bridge/br_netfilter_hooks.c
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.
So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With the ARM mini2440_defconfig, the bridge netfilter code gets
built with both CONFIG_NF_DEFRAG_IPV4 and CONFIG_NF_DEFRAG_IPV6
disabled, which leads to a harmless gcc warning:
net/bridge/br_netfilter_hooks.c: In function 'br_nf_dev_queue_xmit':
net/bridge/br_netfilter_hooks.c:792:2: warning: label 'drop' defined but not used [-Wunused-label]
This gets rid of the warning by cleaning up the code to avoid
the respective #ifdefs causing this problem, and replacing them
with if(IS_ENABLED()) checks. I have verified that the resulting
object code is unchanged, and an additional advantage is that
we now get compile coverage of the unused functions in more
configurations.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: dd302b59bd ("netfilter: bridge: don't leak skb in error paths")
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The network namespace is easiliy available in state->net so use it.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only pass the void *priv parameter out of the nf_hook_ops. That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is immediately motivated by the bridge code that chains functions that
call into netfilter. Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.
As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.
To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn. For the moment dst_output_okfn
just silently drops the struct net.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass a network namespace parameter into the netfilter hooks. At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.
This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".
In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.
The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume() xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont() ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont() ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc() sock_net(sk)
ipv6/ip6_output.c:ip6_xmit() sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb() dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc() sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev
In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)". I am documenting them in case something odd
pops up and someone starts trying to track down what happened.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is prep work for passing net to the netfilter hooks.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When struct net starts being passed through the ipv4 and ipv6 fragment
routines br_nf_push_frag_xmit will need to take a net parameter.
Prepare br_nf_push_frag_xmit before that is needed and introduce
br_nf_push_frag_xmit_sk for the call sites that still need the old
calling conventions.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a prep work for passing struct net through ip_do_fragment and
later the netfilter okfn. Doing this independently makes the later
code changes clearer.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix checkpatch.pl "ERROR: do not initialise statics to 0 or NULL" for
all statics explicitly initialized to 0.
Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We can use union for most of the temporary cruft (original ipv4/ipv6
address, source mac, physoutdev) since they're used during different
stages of br netfilter traversal.
Also get rid of the last two ->mask users.
Shrinks struct from 48 to 32 on 64bit arch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
br_nf_dev_queue_xmit must free skb in its error path.
NF_DROP is misleading -- its an okfn, not a netfilter hook.
Fixes: 462fb2af97 ("bridge : Sanitize skb before it enters the IP stack")
Fixes: efb6de9b4b ("netfilter: bridge: forward IPv6 fragmented packets")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
br_nf_ip_fragment() is not needed when neither CONFIG_NF_DEFRAG_IPV4 nor
CONFIG_NF_DEFRAG_IPV6 is set.
struct brnf_frag_data must be available if either CONFIG_NF_DEFRAG_IPV4
or CONFIG_NF_DEFRAG_IPV6 is set.
Fixes: efb6de9b4b ("netfilter: bridge: forward IPv6 fragmented packets")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Resolve compilation breakage when CONFIG_IPV6 is not set by moving the IPv6
code into a separated br_netfilter_ipv6.c file.
Fixes: efb6de9b4b ("netfilter: bridge: forward IPv6 fragmented packets")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
