<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/net, branch v3.12.33</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets</title>
<updated>2014-11-13T18:01:51+00:00</updated>
<author>
<name>Ben Hutchings</name>
<email>ben@decadent.org.uk</email>
</author>
<published>2014-10-30T18:27:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=30ab1cf8b31dc6a680ac6443a34d02d9edb9a589'/>
<id>30ab1cf8b31dc6a680ac6443a34d02d9edb9a589</id>
<content type='text'>
[ Upstream commit 5188cd44c55db3e92cd9e77a40b5baa7ed4340f7 ]

UFO is now disabled on all drivers that work with virtio net headers,
but userland may try to send UFO/IPv6 packets anyway.  Instead of
sending with ID=0, we should select identifiers on their behalf (as we
used to).

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Fixes: 916e4cf46d02 ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5188cd44c55db3e92cd9e77a40b5baa7ed4340f7 ]

UFO is now disabled on all drivers that work with virtio net headers,
but userland may try to send UFO/IPv6 packets anyway.  Instead of
sending with ID=0, we should select identifiers on their behalf (as we
used to).

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Fixes: 916e4cf46d02 ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>regulatory: fix misapplied alpha2 fix</title>
<updated>2014-10-29T08:29:02+00:00</updated>
<author>
<name>Eliad Peller</name>
<email>eliad@wizery.com</email>
</author>
<published>2014-06-11T07:23:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=84197d64c418b1b9fb9512defa61f57411df1989'/>
<id>84197d64c418b1b9fb9512defa61f57411df1989</id>
<content type='text'>
Upstream commit a5fe8e7695dc3f547e955ad2b662e3e72969e506 (regulatory:
add NUL to alpha2) contained a hunk that was supposed to be applied to
struct ieee80211_reg_rule.  However in stable 3.12 (3.12.31 in
particular), it ended up in struct regulatory_request. Fix that now.

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Cc: Johannes Berg &lt;johannes.berg@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Upstream commit a5fe8e7695dc3f547e955ad2b662e3e72969e506 (regulatory:
add NUL to alpha2) contained a hunk that was supposed to be applied to
struct ieee80211_reg_rule.  However in stable 3.12 (3.12.31 in
particular), it ended up in struct regulatory_request. Fix that now.

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Cc: Johannes Berg &lt;johannes.berg@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sctp: handle association restarts when the socket is closed.</title>
<updated>2014-10-17T07:43:19+00:00</updated>
<author>
<name>Vlad Yasevich</name>
<email>vyasevich@gmail.com</email>
</author>
<published>2014-10-03T22:16:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e6fd6243cdc7434e7001589099394321a1670b47'/>
<id>e6fd6243cdc7434e7001589099394321a1670b47</id>
<content type='text'>
[ Upstream commit bdf6fa52f01b941d4a80372d56de465bdbbd1d23 ]

Currently association restarts do not take into consideration the
state of the socket.  When a restart happens, the current assocation
simply transitions into established state.  This creates a condition
where a remote system, through a the restart procedure, may create a
local association that is no way reachable by user.  The conditions
to trigger this are as follows:
  1) Remote does not acknoledge some data causing data to remain
     outstanding.
  2) Local application calls close() on the socket.  Since data
     is still outstanding, the association is placed in SHUTDOWN_PENDING
     state.  However, the socket is closed.
  3) The remote tries to create a new association, triggering a restart
     on the local system.  The association moves from SHUTDOWN_PENDING
     to ESTABLISHED.  At this point, it is no longer reachable by
     any socket on the local system.

This patch addresses the above situation by moving the newly ESTABLISHED
association into SHUTDOWN-SENT state and bundling a SHUTDOWN after
the COOKIE-ACK chunk.  This way, the restarted associate immidiately
enters the shutdown procedure and forces the termination of the
unreachable association.

Reported-by: David Laight &lt;David.Laight@aculab.com&gt;
Signed-off-by: Vlad Yasevich &lt;vyasevich@gmail.com&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 bdf6fa52f01b941d4a80372d56de465bdbbd1d23 ]

Currently association restarts do not take into consideration the
state of the socket.  When a restart happens, the current assocation
simply transitions into established state.  This creates a condition
where a remote system, through a the restart procedure, may create a
local association that is no way reachable by user.  The conditions
to trigger this are as follows:
  1) Remote does not acknoledge some data causing data to remain
     outstanding.
  2) Local application calls close() on the socket.  Since data
     is still outstanding, the association is placed in SHUTDOWN_PENDING
     state.  However, the socket is closed.
  3) The remote tries to create a new association, triggering a restart
     on the local system.  The association moves from SHUTDOWN_PENDING
     to ESTABLISHED.  At this point, it is no longer reachable by
     any socket on the local system.

This patch addresses the above situation by moving the newly ESTABLISHED
association into SHUTDOWN-SENT state and bundling a SHUTDOWN after
the COOKIE-ACK chunk.  This way, the restarted associate immidiately
enters the shutdown procedure and forces the termination of the
unreachable association.

Reported-by: David Laight &lt;David.Laight@aculab.com&gt;
Signed-off-by: Vlad Yasevich &lt;vyasevich@gmail.com&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>xfrm: Generate queueing routes only from route lookup functions</title>
<updated>2014-10-17T07:43:16+00:00</updated>
<author>
<name>Steffen Klassert</name>
<email>steffen.klassert@secunet.com</email>
</author>
<published>2014-09-16T08:08:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2a9e5d6b68e0d88843caeeb69944e17c632f8a73'/>
<id>2a9e5d6b68e0d88843caeeb69944e17c632f8a73</id>
<content type='text'>
[ Upstream commit b8c203b2d2fc961bafd53b41d5396bbcdec55998 ]

Currently we genarate a queueing route if we have matching policies
but can not resolve the states and the sysctl xfrm_larval_drop is
disabled. Here we assume that dst_output() is called to kill the
queued packets. Unfortunately this assumption is not true in all
cases, so it is possible that these packets leave the system unwanted.

We fix this by generating queueing routes only from the
route lookup functions, here we can guarantee a call to
dst_output() afterwards.

Fixes: a0073fe18e71 ("xfrm: Add a state resolution packet queue")
Reported-by: Konstantinos Kolelis &lt;k.kolelis@sirrix.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&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 b8c203b2d2fc961bafd53b41d5396bbcdec55998 ]

Currently we genarate a queueing route if we have matching policies
but can not resolve the states and the sysctl xfrm_larval_drop is
disabled. Here we assume that dst_output() is called to kill the
queued packets. Unfortunately this assumption is not true in all
cases, so it is possible that these packets leave the system unwanted.

We fix this by generating queueing routes only from the
route lookup functions, here we can guarantee a call to
dst_output() afterwards.

Fixes: a0073fe18e71 ("xfrm: Add a state resolution packet queue")
Reported-by: Konstantinos Kolelis &lt;k.kolelis@sirrix.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xfrm: Generate blackhole routes only from route lookup functions</title>
<updated>2014-10-17T07:43:16+00:00</updated>
<author>
<name>Steffen Klassert</name>
<email>steffen.klassert@secunet.com</email>
</author>
<published>2014-09-16T08:08:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e5a51bbc5bacc7131a8ff04412468a0517dbb2b2'/>
<id>e5a51bbc5bacc7131a8ff04412468a0517dbb2b2</id>
<content type='text'>
[ Upstream commit f92ee61982d6da15a9e49664ecd6405a15a2ee56 ]

Currently we genarate a blackhole route route whenever we have
matching policies but can not resolve the states. Here we assume
that dst_output() is called to kill the balckholed packets.
Unfortunately this assumption is not true in all cases, so
it is possible that these packets leave the system unwanted.

We fix this by generating blackhole routes only from the
route lookup functions, here we can guarantee a call to
dst_output() afterwards.

Fixes: 2774c131b1d ("xfrm: Handle blackhole route creation via afinfo.")
Reported-by: Konstantinos Kolelis &lt;k.kolelis@sirrix.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&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 f92ee61982d6da15a9e49664ecd6405a15a2ee56 ]

Currently we genarate a blackhole route route whenever we have
matching policies but can not resolve the states. Here we assume
that dst_output() is called to kill the balckholed packets.
Unfortunately this assumption is not true in all cases, so
it is possible that these packets leave the system unwanted.

We fix this by generating blackhole routes only from the
route lookup functions, here we can guarantee a call to
dst_output() afterwards.

Fixes: 2774c131b1d ("xfrm: Handle blackhole route creation via afinfo.")
Reported-by: Konstantinos Kolelis &lt;k.kolelis@sirrix.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()</title>
<updated>2014-10-17T07:43:12+00:00</updated>
<author>
<name>Neal Cardwell</name>
<email>ncardwell@google.com</email>
</author>
<published>2014-08-14T16:40:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8e2aadd34bfee8db9253431c3c8e5457c130f608'/>
<id>8e2aadd34bfee8db9253431c3c8e5457c130f608</id>
<content type='text'>
[ Upstream commit 4fab9071950c2021d846e18351e0f46a1cffd67b ]

Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Diagnosed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications")
Reviewed-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&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 4fab9071950c2021d846e18351e0f46a1cffd67b ]

Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Diagnosed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications")
Reviewed-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&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>regulatory: add NUL to alpha2</title>
<updated>2014-10-13T13:41:25+00:00</updated>
<author>
<name>Eliad Peller</name>
<email>eliad@wizery.com</email>
</author>
<published>2014-06-11T07:23:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=91a95b41f3abe8071e62193668f8c3e7dbd5e94f'/>
<id>91a95b41f3abe8071e62193668f8c3e7dbd5e94f</id>
<content type='text'>
commit a5fe8e7695dc3f547e955ad2b662e3e72969e506 upstream.

alpha2 is defined as 2-chars array, but is used in multiple
places as string (e.g. with nla_put_string calls), which
might leak kernel data.

Solve it by simply adding an extra char for the NULL
terminator, making such operations safe.

Signed-off-by: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&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 a5fe8e7695dc3f547e955ad2b662e3e72969e506 upstream.

alpha2 is defined as 2-chars array, but is used in multiple
places as string (e.g. with nla_put_string calls), which
might leak kernel data.

Solve it by simply adding an extra char for the NULL
terminator, making such operations safe.

Signed-off-by: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mac80211: reset probe_send_count also in HW_CONNECTION_MONITOR case</title>
<updated>2014-08-26T12:12:02+00:00</updated>
<author>
<name>Eliad Peller</name>
<email>eliad@wizery.com</email>
</author>
<published>2014-02-11T10:30:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d7c722da3c3aeed898eccbad143ff6bfd84812e5'/>
<id>d7c722da3c3aeed898eccbad143ff6bfd84812e5</id>
<content type='text'>
commit 448cd2e248732326632957e52ea9c44729affcb2 upstream.

In case of beacon_loss with IEEE80211_HW_CONNECTION_MONITOR
device, mac80211 probes the ap (and disconnects on timeout)
but ignores the ack.

If we already got an ack, there's no reason to continue
disconnecting. this can help devices that supports
IEEE80211_HW_CONNECTION_MONITOR only partially (e.g. take
care of keep alives, but does not probe the ap.

In case the device wants to disconnect without probing,
it can just call ieee80211_connection_loss.

Signed-off-by: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&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 448cd2e248732326632957e52ea9c44729affcb2 upstream.

In case of beacon_loss with IEEE80211_HW_CONNECTION_MONITOR
device, mac80211 probes the ap (and disconnects on timeout)
but ignores the ack.

If we already got an ack, there's no reason to continue
disconnecting. this can help devices that supports
IEEE80211_HW_CONNECTION_MONITOR only partially (e.g. take
care of keep alives, but does not probe the ap.

In case the device wants to disconnect without probing,
it can just call ieee80211_connection_loss.

Signed-off-by: Eliad Peller &lt;eliadx.peller@intel.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ip: make IP identifiers less predictable</title>
<updated>2014-08-19T15:15:00+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2014-07-26T06:58:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b03bce84364b12644b35a88f6d9e88bfcb7aacc'/>
<id>2b03bce84364b12644b35a88f6d9e88bfcb7aacc</id>
<content type='text'>
[ Upstream commit 04ca6973f7c1a0d8537f2d9906a0cf8e69886d75 ]

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.

With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.

This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.

Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.

This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.

We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.

For IPv6, adds saddr into the hash as well, but not nexthdr.

If I ping the patched target, we can see ID are now hard to predict.

21:57:11.008086 IP (...)
    A &gt; target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
    target &gt; A: ICMP echo reply, seq 1, length 64

21:57:12.013133 IP (...)
    A &gt; target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
    target &gt; A: ICMP echo reply, seq 2, length 64

21:57:13.016580 IP (...)
    A &gt; target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
    target &gt; A: ICMP echo reply, seq 3, length 64

[1] TCP sessions uses a per flow ID generator not changed by this patch.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Jeffrey Knockel &lt;jeffk@cs.unm.edu&gt;
Reported-by: Jedidiah R. Crandall &lt;crandall@cs.unm.edu&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Hannes Frederic Sowa &lt;hannes@redhat.com&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 04ca6973f7c1a0d8537f2d9906a0cf8e69886d75 ]

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.

With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.

This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.

Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.

This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.

We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.

For IPv6, adds saddr into the hash as well, but not nexthdr.

If I ping the patched target, we can see ID are now hard to predict.

21:57:11.008086 IP (...)
    A &gt; target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
    target &gt; A: ICMP echo reply, seq 1, length 64

21:57:12.013133 IP (...)
    A &gt; target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
    target &gt; A: ICMP echo reply, seq 2, length 64

21:57:13.016580 IP (...)
    A &gt; target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
    target &gt; A: ICMP echo reply, seq 3, length 64

[1] TCP sessions uses a per flow ID generator not changed by this patch.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Jeffrey Knockel &lt;jeffk@cs.unm.edu&gt;
Reported-by: Jedidiah R. Crandall &lt;crandall@cs.unm.edu&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Hannes Frederic Sowa &lt;hannes@redhat.com&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>inetpeer: get rid of ip_id_count</title>
<updated>2014-08-19T15:15:00+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2014-06-02T12:26:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=16cc7c2f0ce25aaa048b626477f594668203c44d'/>
<id>16cc7c2f0ce25aaa048b626477f594668203c44d</id>
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[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
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<pre>
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
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