<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/ipv6/netfilter, branch v3.12.52</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>netfilter: ip6t_SYNPROXY: fix NULL pointer dereference</title>
<updated>2016-01-05T16:01:29+00:00</updated>
<author>
<name>Phil Sutter</name>
<email>phil@nwl.cc</email>
</author>
<published>2015-08-09T11:14:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b80a514e3c8957a68608825ccbd18ff18420ff1e'/>
<id>b80a514e3c8957a68608825ccbd18ff18420ff1e</id>
<content type='text'>
commit 96fffb4f23f124f297d51dedc9cf51d19eb88ee1 upstream.

This happens when networking namespaces are enabled.

Suggested-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 96fffb4f23f124f297d51dedc9cf51d19eb88ee1 upstream.

This happens when networking namespaces are enabled.

Suggested-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: distinguish frag queues by device for multicast and link-local packets</title>
<updated>2016-01-05T15:11:13+00:00</updated>
<author>
<name>Michal Kubeček</name>
<email>mkubecek@suse.cz</email>
</author>
<published>2015-11-24T14:07:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eac843e433fe2b8c25b55a0cf4294b12f05742e9'/>
<id>eac843e433fe2b8c25b55a0cf4294b12f05742e9</id>
<content type='text'>
[ Upstream commit 264640fc2c5f4f913db5c73fa3eb1ead2c45e9d7 ]

If a fragmented multicast packet is received on an ethernet device which
has an active macvlan on top of it, each fragment is duplicated and
received both on the underlying device and the macvlan. If some
fragments for macvlan are processed before the whole packet for the
underlying device is reassembled, the "overlapping fragments" test in
ip6_frag_queue() discards the whole fragment queue.

To resolve this, add device ifindex to the search key and require it to
match reassembling multicast packets and packets to link-local
addresses.

Note: similar patch has been already submitted by Yoshifuji Hideaki in

  http://patchwork.ozlabs.org/patch/220979/

but got lost and forgotten for some reason.

Signed-off-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 264640fc2c5f4f913db5c73fa3eb1ead2c45e9d7 ]

If a fragmented multicast packet is received on an ethernet device which
has an active macvlan on top of it, each fragment is duplicated and
received both on the underlying device and the macvlan. If some
fragments for macvlan are processed before the whole packet for the
underlying device is reassembled, the "overlapping fragments" test in
ip6_frag_queue() discards the whole fragment queue.

To resolve this, add device ifindex to the search key and require it to
match reassembling multicast packets and packets to link-local
addresses.

Note: similar patch has been already submitted by Yoshifuji Hideaki in

  http://patchwork.ozlabs.org/patch/220979/

but got lost and forgotten for some reason.

Signed-off-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: Can't fail and free after table replacement</title>
<updated>2014-05-29T09:38:09+00:00</updated>
<author>
<name>Thomas Graf</name>
<email>tgraf@suug.ch</email>
</author>
<published>2014-04-04T15:57:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f34728610b2a8c7b9864f9404f2884c17f6fca5c'/>
<id>f34728610b2a8c7b9864f9404f2884c17f6fca5c</id>
<content type='text'>
commit c58dd2dd443c26d856a168db108a0cd11c285bf3 upstream.

All xtables variants suffer from the defect that the copy_to_user()
to copy the counters to user memory may fail after the table has
already been exchanged and thus exposed. Return an error at this
point will result in freeing the already exposed table. Any
subsequent packet processing will result in a kernel panic.

We can't copy the counters before exposing the new tables as we
want provide the counter state after the old table has been
unhooked. Therefore convert this into a silent error.

Cc: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c58dd2dd443c26d856a168db108a0cd11c285bf3 upstream.

All xtables variants suffer from the defect that the copy_to_user()
to copy the counters to user memory may fail after the table has
already been exchanged and thus exposed. Return an error at this
point will result in freeing the already exposed table. Any
subsequent packet processing will result in a kernel panic.

We can't copy the counters before exposing the new tables as we
want provide the counter state after the old table has been
unhooked. Therefore convert this into a silent error.

Cc: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: push reasm skb through instead of original frag skbs</title>
<updated>2013-12-08T15:29:13+00:00</updated>
<author>
<name>Jiri Pirko</name>
<email>jiri@resnulli.us</email>
</author>
<published>2013-11-06T16:52:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0a6905b2186e5ae1715545d067dde8ad830fc3f5'/>
<id>0a6905b2186e5ae1715545d067dde8ad830fc3f5</id>
<content type='text'>
[ Upstream commit 6aafeef03b9d9ecf255f3a80ed85ee070260e1ae ]

Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:

&lt;example&gt;
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT

and on HOSTB you do:
ping6 HOSTA -s2000    (MTU is 1500)

Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
&lt;/example&gt;

As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.

Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.

Signed-off-by: Jiri Pirko &lt;jiri@resnulli.us&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Marcelo Ricardo Leitner &lt;mleitner@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6aafeef03b9d9ecf255f3a80ed85ee070260e1ae ]

Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:

&lt;example&gt;
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT

and on HOSTB you do:
ping6 HOSTA -s2000    (MTU is 1500)

Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
&lt;/example&gt;

As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.

Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.

Signed-off-by: Jiri Pirko &lt;jiri@resnulli.us&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Marcelo Ricardo Leitner &lt;mleitner@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: synproxy: fix BUG_ON triggered by corrupt TCP packets</title>
<updated>2013-09-30T10:44:38+00:00</updated>
<author>
<name>Patrick McHardy</name>
<email>kaber@trash.net</email>
</author>
<published>2013-09-30T07:51:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f4a87e7bd2eaef26a3ca25437ce8b807de2966ad'/>
<id>f4a87e7bd2eaef26a3ca25437ce8b807de2966ad</id>
<content type='text'>
TCP packets hitting the SYN proxy through the SYNPROXY target are not
validated by TCP conntrack. When th-&gt;doff is below 5, an underflow happens
when calculating the options length, causing skb_header_pointer() to
return NULL and triggering the BUG_ON().

Handle this case gracefully by checking for NULL instead of using BUG_ON().

Reported-by: Martin Topholm &lt;mph@one.com&gt;
Tested-by: Martin Topholm &lt;mph@one.com&gt;
Signed-off-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
TCP packets hitting the SYN proxy through the SYNPROXY target are not
validated by TCP conntrack. When th-&gt;doff is below 5, an underflow happens
when calculating the options length, causing skb_header_pointer() to
return NULL and triggering the BUG_ON().

Handle this case gracefully by checking for NULL instead of using BUG_ON().

Reported-by: Martin Topholm &lt;mph@one.com&gt;
Tested-by: Martin Topholm &lt;mph@one.com&gt;
Signed-off-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_nat_proto_icmpv6:: fix wrong comparison in icmpv6_manip_pkt</title>
<updated>2013-09-13T09:58:48+00:00</updated>
<author>
<name>Phil Oester</name>
<email>kernel@linuxace.com</email>
</author>
<published>2013-09-13T01:04:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d830f0fa1dd7ca447c38aec82cd44230e0b7ca75'/>
<id>d830f0fa1dd7ca447c38aec82cd44230e0b7ca75</id>
<content type='text'>
In commit 58a317f1 (netfilter: ipv6: add IPv6 NAT support), icmpv6_manip_pkt
was added with an incorrect comparison of ICMP codes to types.  This causes
problems when using NAT rules with the --random option.  Correct the
comparison.

This closes netfilter bugzilla #851, reported by Alexander Neumann.

Signed-off-by: Phil Oester &lt;kernel@linuxace.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In commit 58a317f1 (netfilter: ipv6: add IPv6 NAT support), icmpv6_manip_pkt
was added with an incorrect comparison of ICMP codes to types.  This causes
problems when using NAT rules with the --random option.  Correct the
comparison.

This closes netfilter bugzilla #851, reported by Alexander Neumann.

Signed-off-by: Phil Oester &lt;kernel@linuxace.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next</title>
<updated>2013-09-05T21:54:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-09-05T21:54:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cc998ff8811530be521f6b316f37ab7676a07938'/>
<id>cc998ff8811530be521f6b316f37ab7676a07938</id>
<content type='text'>
Pull networking changes from David Miller:
 "Noteworthy changes this time around:

   1) Multicast rejoin support for team driver, from Jiri Pirko.

   2) Centralize and simplify TCP RTT measurement handling in order to
      reduce the impact of bad RTO seeding from SYN/ACKs.  Also, when
      both timestamps and local RTT measurements are available prefer
      the later because there are broken middleware devices which
      scramble the timestamp.

      From Yuchung Cheng.

   3) Add TCP_NOTSENT_LOWAT socket option to limit the amount of kernel
      memory consumed to queue up unsend user data.  From Eric Dumazet.

   4) Add a "physical port ID" abstraction for network devices, from
      Jiri Pirko.

   5) Add a "suppress" operation to influence fib_rules lookups, from
      Stefan Tomanek.

   6) Add a networking development FAQ, from Paul Gortmaker.

   7) Extend the information provided by tcp_probe and add ipv6 support,
      from Daniel Borkmann.

   8) Use RCU locking more extensively in openvswitch data paths, from
      Pravin B Shelar.

   9) Add SCTP support to openvswitch, from Joe Stringer.

  10) Add EF10 chip support to SFC driver, from Ben Hutchings.

  11) Add new SYNPROXY netfilter target, from Patrick McHardy.

  12) Compute a rate approximation for sending in TCP sockets, and use
      this to more intelligently coalesce TSO frames.  Furthermore, add
      a new packet scheduler which takes advantage of this estimate when
      available.  From Eric Dumazet.

  13) Allow AF_PACKET fanouts with random selection, from Daniel
      Borkmann.

  14) Add ipv6 support to vxlan driver, from Cong Wang"

Resolved conflicts as per discussion.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1218 commits)
  openvswitch: Fix alignment of struct sw_flow_key.
  netfilter: Fix build errors with xt_socket.c
  tcp: Add missing braces to do_tcp_setsockopt
  caif: Add missing braces to multiline if in cfctrl_linkup_request
  bnx2x: Add missing braces in bnx2x:bnx2x_link_initialize
  vxlan: Fix kernel panic on device delete.
  net: mvneta: implement -&gt;ndo_do_ioctl() to support PHY ioctls
  net: mvneta: properly disable HW PHY polling and ensure adjust_link() works
  icplus: Use netif_running to determine device state
  ethernet/arc/arc_emac: Fix huge delays in large file copies
  tuntap: orphan frags before trying to set tx timestamp
  tuntap: purge socket error queue on detach
  qlcnic: use standard NAPI weights
  ipv6:introduce function to find route for redirect
  bnx2x: VF RSS support - VF side
  bnx2x: VF RSS support - PF side
  vxlan: Notify drivers for listening UDP port changes
  net: usbnet: update addr_assign_type if appropriate
  driver/net: enic: update enic maintainers and driver
  driver/net: enic: Exposing symbols for Cisco's low latency driver
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking changes from David Miller:
 "Noteworthy changes this time around:

   1) Multicast rejoin support for team driver, from Jiri Pirko.

   2) Centralize and simplify TCP RTT measurement handling in order to
      reduce the impact of bad RTO seeding from SYN/ACKs.  Also, when
      both timestamps and local RTT measurements are available prefer
      the later because there are broken middleware devices which
      scramble the timestamp.

      From Yuchung Cheng.

   3) Add TCP_NOTSENT_LOWAT socket option to limit the amount of kernel
      memory consumed to queue up unsend user data.  From Eric Dumazet.

   4) Add a "physical port ID" abstraction for network devices, from
      Jiri Pirko.

   5) Add a "suppress" operation to influence fib_rules lookups, from
      Stefan Tomanek.

   6) Add a networking development FAQ, from Paul Gortmaker.

   7) Extend the information provided by tcp_probe and add ipv6 support,
      from Daniel Borkmann.

   8) Use RCU locking more extensively in openvswitch data paths, from
      Pravin B Shelar.

   9) Add SCTP support to openvswitch, from Joe Stringer.

  10) Add EF10 chip support to SFC driver, from Ben Hutchings.

  11) Add new SYNPROXY netfilter target, from Patrick McHardy.

  12) Compute a rate approximation for sending in TCP sockets, and use
      this to more intelligently coalesce TSO frames.  Furthermore, add
      a new packet scheduler which takes advantage of this estimate when
      available.  From Eric Dumazet.

  13) Allow AF_PACKET fanouts with random selection, from Daniel
      Borkmann.

  14) Add ipv6 support to vxlan driver, from Cong Wang"

Resolved conflicts as per discussion.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1218 commits)
  openvswitch: Fix alignment of struct sw_flow_key.
  netfilter: Fix build errors with xt_socket.c
  tcp: Add missing braces to do_tcp_setsockopt
  caif: Add missing braces to multiline if in cfctrl_linkup_request
  bnx2x: Add missing braces in bnx2x:bnx2x_link_initialize
  vxlan: Fix kernel panic on device delete.
  net: mvneta: implement -&gt;ndo_do_ioctl() to support PHY ioctls
  net: mvneta: properly disable HW PHY polling and ensure adjust_link() works
  icplus: Use netif_running to determine device state
  ethernet/arc/arc_emac: Fix huge delays in large file copies
  tuntap: orphan frags before trying to set tx timestamp
  tuntap: purge socket error queue on detach
  qlcnic: use standard NAPI weights
  ipv6:introduce function to find route for redirect
  bnx2x: VF RSS support - VF side
  bnx2x: VF RSS support - PF side
  vxlan: Notify drivers for listening UDP port changes
  net: usbnet: update addr_assign_type if appropriate
  driver/net: enic: update enic maintainers and driver
  driver/net: enic: Exposing symbols for Cisco's low latency driver
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: SYNPROXY: let unrelated packets continue</title>
<updated>2013-09-04T09:44:23+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2013-08-29T10:18:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7cc9eb6ef78d0dcb97d543ea19966486e98afa0b'/>
<id>7cc9eb6ef78d0dcb97d543ea19966486e98afa0b</id>
<content type='text'>
Packets reaching SYNPROXY were default dropped, as they were most
likely invalid (given the recommended state matching).  This
patch, changes SYNPROXY target to let packets, not consumed,
continue being processed by the stack.

This will be more in line other target modules. As it will allow
more flexible configurations of handling, logging or matching on
packets in INVALID states.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Packets reaching SYNPROXY were default dropped, as they were most
likely invalid (given the recommended state matching).  This
patch, changes SYNPROXY target to let packets, not consumed,
continue being processed by the stack.

This will be more in line other target modules. As it will allow
more flexible configurations of handling, logging or matching on
packets in INVALID states.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: more strict TCP flag matching in SYNPROXY</title>
<updated>2013-09-04T09:43:11+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2013-08-28T13:14:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=775ada6d9f4c9dc440f5aeca00354eb87f6e0696'/>
<id>775ada6d9f4c9dc440f5aeca00354eb87f6e0696</id>
<content type='text'>
Its seems Patrick missed to incoorporate some of my requested changes
during review v2 of SYNPROXY netfilter module.

Which were, to avoid SYN+ACK packets to enter the path, meant for the
ACK packet from the client (from the 3WHS).

Further there were a bug in ip6t_SYNPROXY.c, for matching SYN packets
that didn't exclude the ACK flag.

Go a step further with SYN packet/flag matching by excluding flags
ACK+FIN+RST, in both IPv4 and IPv6 modules.

The intented usage of SYNPROXY is as follows:
(gracefully describing usage in commit)

 iptables -t raw -A PREROUTING -i eth0 -p tcp --dport 80 --syn -j NOTRACK
 iptables -A INPUT -i eth0 -p tcp --dport 80 -m state UNTRACKED,INVALID \
         -j SYNPROXY --sack-perm --timestamp --mss 1480 --wscale 7 --ecn

 echo 0 &gt; /proc/sys/net/netfilter/nf_conntrack_tcp_loose

This does filter SYN flags early, for packets in the UNTRACKED state,
but packets in the INVALID state with other TCP flags could still
reach the module, thus this stricter flag matching is still needed.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Its seems Patrick missed to incoorporate some of my requested changes
during review v2 of SYNPROXY netfilter module.

Which were, to avoid SYN+ACK packets to enter the path, meant for the
ACK packet from the client (from the 3WHS).

Further there were a bug in ip6t_SYNPROXY.c, for matching SYN packets
that didn't exclude the ACK flag.

Go a step further with SYN packet/flag matching by excluding flags
ACK+FIN+RST, in both IPv4 and IPv6 modules.

The intented usage of SYNPROXY is as follows:
(gracefully describing usage in commit)

 iptables -t raw -A PREROUTING -i eth0 -p tcp --dport 80 --syn -j NOTRACK
 iptables -A INPUT -i eth0 -p tcp --dport 80 -m state UNTRACKED,INVALID \
         -j SYNPROXY --sack-perm --timestamp --mss 1480 --wscale 7 --ecn

 echo 0 &gt; /proc/sys/net/netfilter/nf_conntrack_tcp_loose

This does filter SYN flags early, for packets in the UNTRACKED state,
but packets in the INVALID state with other TCP flags could still
reach the module, thus this stricter flag matching is still needed.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: add IPv6 SYNPROXY target</title>
<updated>2013-08-27T22:28:13+00:00</updated>
<author>
<name>Patrick McHardy</name>
<email>kaber@trash.net</email>
</author>
<published>2013-08-27T06:50:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4ad362282cb45bbc831a182e45637da8c5bd7aa1'/>
<id>4ad362282cb45bbc831a182e45637da8c5bd7aa1</id>
<content type='text'>
Add an IPv6 version of the SYNPROXY target. The main differences to the
IPv4 version is routing and IP header construction.

Signed-off-by: Patrick McHardy &lt;kaber@trash.net&gt;
Tested-by: Martin Topholm &lt;mph@one.com&gt;
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add an IPv6 version of the SYNPROXY target. The main differences to the
IPv4 version is routing and IP header construction.

Signed-off-by: Patrick McHardy &lt;kaber@trash.net&gt;
Tested-by: Martin Topholm &lt;mph@one.com&gt;
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
