<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/ipv4, branch v3.0.71</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>inet: limit length of fragment queue hash table bucket lists</title>
<updated>2013-03-28T19:05:59+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2013-03-15T11:32:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7b7a1b8b3bd1742ca5ab259e741da0070e936db0'/>
<id>7b7a1b8b3bd1742ca5ab259e741da0070e936db0</id>
<content type='text'>
[ Upstream commit 5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 ]

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat
arbitrary and just ensures that we can fill up the fragment cache with
empty packets up to the default ip_frag_high_thresh limits. It should
just protect from list iteration eating considerable amounts of cpu.

If we reach the maximum length in one hash bucket a warning is printed.
This is implemented on the caller side of inet_frag_find to distinguish
between the different users of inet_fragment.c.

I dropped the out of memory warning in the ipv4 fragment lookup path,
because we already get a warning by the slab allocator.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Jesper Dangaard Brouer &lt;jbrouer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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 5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 ]

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat
arbitrary and just ensures that we can fill up the fragment cache with
empty packets up to the default ip_frag_high_thresh limits. It should
just protect from list iteration eating considerable amounts of cpu.

If we reach the maximum length in one hash bucket a warning is printed.
This is implemented on the caller side of inet_frag_find to distinguish
between the different users of inet_fragment.c.

I dropped the out of memory warning in the ipv4 fragment lookup path,
because we already get a warning by the slab allocator.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Jesper Dangaard Brouer &lt;jbrouer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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>net/ipv4: Ensure that location of timestamp option is stored</title>
<updated>2013-03-28T19:05:59+00:00</updated>
<author>
<name>David Ward</name>
<email>david.ward@ll.mit.edu</email>
</author>
<published>2013-03-11T10:43:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c8b46f44552cbf67460fba1c13edcba3339b1c76'/>
<id>c8b46f44552cbf67460fba1c13edcba3339b1c76</id>
<content type='text'>
[ Upstream commit 4660c7f498c07c43173142ea95145e9dac5a6d14 ]

This is needed in order to detect if the timestamp option appears
more than once in a packet, to remove the option if the packet is
fragmented, etc. My previous change neglected to store the option
location when the router addresses were prespecified and Pointer &gt;
Length. But now the option location is also stored when Flag is an
unrecognized value, to ensure these option handling behaviors are
still performed.

Signed-off-by: David Ward &lt;david.ward@ll.mit.edu&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 4660c7f498c07c43173142ea95145e9dac5a6d14 ]

This is needed in order to detect if the timestamp option appears
more than once in a packet, to remove the option if the packet is
fragmented, etc. My previous change neglected to store the option
location when the router addresses were prespecified and Pointer &gt;
Length. But now the option location is also stored when Flag is an
unrecognized value, to ensure these option handling behaviors are
still performed.

Signed-off-by: David Ward &lt;david.ward@ll.mit.edu&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>tcp: fix double-counted receiver RTT when leaving receiver fast path</title>
<updated>2013-03-20T19:58:54+00:00</updated>
<author>
<name>Neal Cardwell</name>
<email>ncardwell@google.com</email>
</author>
<published>2013-03-04T06:23:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b1a7a7672b91264a9ff65be7d39f395522942efc'/>
<id>b1a7a7672b91264a9ff65be7d39f395522942efc</id>
<content type='text'>
[ Upstream commit aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ]

We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both
before and after going to step5. That wastes CPU and double-counts the
receiver-side RTT sample.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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 aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ]

We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both
before and after going to step5. That wastes CPU and double-counts the
receiver-side RTT sample.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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>ipv6: use a stronger hash for tcp</title>
<updated>2013-02-28T14:32:27+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2013-02-21T12:18:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae593067dbed83010fee8ad59bab7948f3d3601f'/>
<id>ae593067dbed83010fee8ad59bab7948f3d3601f</id>
<content type='text'>
[ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ]

It looks like its possible to open thousands of TCP IPv6
sessions on a server, all landing in a single slot of TCP hash
table. Incoming packets have to lookup sockets in a very
long list.

We should hash all bits from foreign IPv6 addresses, using
a salt and hash mix, not a simple XOR.

inet6_ehashfn() can also separately use the ports, instead
of xoring them.

Reported-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Yuchung Cheng &lt;ycheng@google.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 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ]

It looks like its possible to open thousands of TCP IPv6
sessions on a server, all landing in a single slot of TCP hash
table. Incoming packets have to lookup sockets in a very
long list.

We should hash all bits from foreign IPv6 addresses, using
a salt and hash mix, not a simple XOR.

inet6_ehashfn() can also separately use the ports, instead
of xoring them.

Reported-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Yuchung Cheng &lt;ycheng@google.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>ipv4: fix a bug in ping_err().</title>
<updated>2013-02-28T14:32:27+00:00</updated>
<author>
<name>Li Wei</name>
<email>lw@cn.fujitsu.com</email>
</author>
<published>2013-02-21T00:09:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b18383129b00d2d6aac160f55e27c5ba1cf9d49b'/>
<id>b18383129b00d2d6aac160f55e27c5ba1cf9d49b</id>
<content type='text'>
[ Upstream commit b531ed61a2a2a77eeb2f7c88b49aa5ec7d9880d8 ]

We should get 'type' and 'code' from the outer ICMP header.

Signed-off-by: Li Wei &lt;lw@cn.fujitsu.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 b531ed61a2a2a77eeb2f7c88b49aa5ec7d9880d8 ]

We should get 'type' and 'code' from the outer ICMP header.

Signed-off-by: Li Wei &lt;lw@cn.fujitsu.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>tcp: fix for zero packets_in_flight was too broad</title>
<updated>2013-02-14T18:47:35+00:00</updated>
<author>
<name>Ilpo Järvinen</name>
<email>ilpo.jarvinen@helsinki.fi</email>
</author>
<published>2013-02-04T02:14:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=31885683c218d57ff90d827a1be5c5d3cb4263ac'/>
<id>31885683c218d57ff90d827a1be5c5d3cb4263ac</id>
<content type='text'>
[ Upstream commit 6731d2095bd4aef18027c72ef845ab1087c3ba63 ]

There are transients during normal FRTO procedure during which
the packets_in_flight can go to zero between write_queue state
updates and firing the resulting segments out. As FRTO processing
occurs during that window the check must be more precise to
not match "spuriously" :-). More specificly, e.g., when
packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic
branch that set cwnd into zero would not be taken and new segments
might be sent out later.

Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@helsinki.fi&gt;
Tested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.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 6731d2095bd4aef18027c72ef845ab1087c3ba63 ]

There are transients during normal FRTO procedure during which
the packets_in_flight can go to zero between write_queue state
updates and firing the resulting segments out. As FRTO processing
occurs during that window the check must be more precise to
not match "spuriously" :-). More specificly, e.g., when
packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic
branch that set cwnd into zero would not be taken and new segments
might be sent out later.

Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@helsinki.fi&gt;
Tested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.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>tcp: frto should not set snd_cwnd to 0</title>
<updated>2013-02-14T18:47:35+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2013-02-03T09:13:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ff1e4e5817d104e9aa46305db294602514e1c12b'/>
<id>ff1e4e5817d104e9aa46305db294602514e1c12b</id>
<content type='text'>
[ Upstream commit 2e5f421211ff76c17130b4597bc06df4eeead24f ]

Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start())
uncovered a bug in FRTO code :
tcp_process_frto() is setting snd_cwnd to 0 if the number
of in flight packets is 0.

As Neal pointed out, if no packet is in flight we lost our
chance to disambiguate whether a loss timeout was spurious.

We should assume it was a proper loss.

Reported-by: Pasi Kärkkäinen &lt;pasik@iki.fi&gt;
Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ilpo Järvinen &lt;ilpo.jarvinen@helsinki.fi&gt;
Cc: Yuchung Cheng &lt;ycheng@google.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 2e5f421211ff76c17130b4597bc06df4eeead24f ]

Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start())
uncovered a bug in FRTO code :
tcp_process_frto() is setting snd_cwnd to 0 if the number
of in flight packets is 0.

As Neal pointed out, if no packet is in flight we lost our
chance to disambiguate whether a loss timeout was spurious.

We should assume it was a proper loss.

Reported-by: Pasi Kärkkäinen &lt;pasik@iki.fi&gt;
Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ilpo Järvinen &lt;ilpo.jarvinen@helsinki.fi&gt;
Cc: Yuchung Cheng &lt;ycheng@google.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>net: prevent setting ttl=0 via IP_TTL</title>
<updated>2013-02-14T18:47:33+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2013-01-07T21:17:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cadce465a66df20878bfa5062092a64ab17c6042'/>
<id>cadce465a66df20878bfa5062092a64ab17c6042</id>
<content type='text'>
[ Upstream commit c9be4a5c49cf51cc70a993f004c5bb30067a65ce ]

A regression is introduced by the following commit:

	commit 4d52cfbef6266092d535237ba5a4b981458ab171
	Author: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
	Date:   Tue Jun 2 00:42:16 2009 -0700

	    net: ipv4/ip_sockglue.c cleanups

	    Pure cleanups

but it is not a pure cleanup...

	-               if (val != -1 &amp;&amp; (val &lt; 1 || val&gt;255))
	+               if (val != -1 &amp;&amp; (val &lt; 0 || val &gt; 255))

Since there is no reason provided to allow ttl=0, change it back.

Reported-by: nitin padalia &lt;padalia.nitin@gmail.com&gt;
Cc: nitin padalia &lt;padalia.nitin@gmail.com&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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 c9be4a5c49cf51cc70a993f004c5bb30067a65ce ]

A regression is introduced by the following commit:

	commit 4d52cfbef6266092d535237ba5a4b981458ab171
	Author: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
	Date:   Tue Jun 2 00:42:16 2009 -0700

	    net: ipv4/ip_sockglue.c cleanups

	    Pure cleanups

but it is not a pure cleanup...

	-               if (val != -1 &amp;&amp; (val &lt; 1 || val&gt;255))
	+               if (val != -1 &amp;&amp; (val &lt; 0 || val &gt; 255))

Since there is no reason provided to allow ttl=0, change it back.

Reported-by: nitin padalia &lt;padalia.nitin@gmail.com&gt;
Cc: nitin padalia &lt;padalia.nitin@gmail.com&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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>rtnetlink: Compute and store minimum ifinfo dump size</title>
<updated>2013-01-17T16:43:58+00:00</updated>
<author>
<name>Greg Rose</name>
<email>gregory.v.rose@intel.com</email>
</author>
<published>2013-01-04T00:32:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e3cbdeae8e4d13087657d95ed7a5be57dc9695e'/>
<id>2e3cbdeae8e4d13087657d95ed7a5be57dc9695e</id>
<content type='text'>
commit c7ac8679bec9397afe8918f788cbcef88c38da54 upstream.

The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose &lt;gregory.v.rose@intel.com&gt;
Signed-off-by: Jeff Kirsher &lt;jeffrey.t.kirsher@intel.com&gt;
Cc: Ben Hutchings &lt;bhutchings@solarflare.com&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>
commit c7ac8679bec9397afe8918f788cbcef88c38da54 upstream.

The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose &lt;gregory.v.rose@intel.com&gt;
Signed-off-by: Jeff Kirsher &lt;jeffrey.t.kirsher@intel.com&gt;
Cc: Ben Hutchings &lt;bhutchings@solarflare.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation</title>
<updated>2013-01-11T17:03:48+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2012-10-21T19:57:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8d15569e14cfcf9151e9e3b4c0cb98369943a2bb'/>
<id>8d15569e14cfcf9151e9e3b4c0cb98369943a2bb</id>
<content type='text'>
[ Upstream commit 354e4aa391ed50a4d827ff6fc11e0667d0859b25 ]

RFC 5961 5.2 [Blind Data Injection Attack].[Mitigation]

  All TCP stacks MAY implement the following mitigation.  TCP stacks
  that implement this mitigation MUST add an additional input check to
  any incoming segment.  The ACK value is considered acceptable only if
  it is in the range of ((SND.UNA - MAX.SND.WND) &lt;= SEG.ACK &lt;=
  SND.NXT).  All incoming segments whose ACK value doesn't satisfy the
  above condition MUST be discarded and an ACK sent back.

Move tcp_send_challenge_ack() before tcp_ack() to avoid a forward
declaration.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Yuchung Cheng &lt;ycheng@google.com&gt;
Cc: Jerry Chu &lt;hkchu@google.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 354e4aa391ed50a4d827ff6fc11e0667d0859b25 ]

RFC 5961 5.2 [Blind Data Injection Attack].[Mitigation]

  All TCP stacks MAY implement the following mitigation.  TCP stacks
  that implement this mitigation MUST add an additional input check to
  any incoming segment.  The ACK value is considered acceptable only if
  it is in the range of ((SND.UNA - MAX.SND.WND) &lt;= SEG.ACK &lt;=
  SND.NXT).  All incoming segments whose ACK value doesn't satisfy the
  above condition MUST be discarded and an ACK sent back.

Move tcp_send_challenge_ack() before tcp_ack() to avoid a forward
declaration.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Yuchung Cheng &lt;ycheng@google.com&gt;
Cc: Jerry Chu &lt;hkchu@google.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>
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