<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/dccp, branch v3.14-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>ipv4: introduce hardened ip_no_pmtu_disc mode</title>
<updated>2014-01-13T19:22:55+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2014-01-09T09:01:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e'/>
<id>8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e</id>
<content type='text'>
This new ip_no_pmtu_disc mode only allowes fragmentation-needed errors
to be honored by protocols which do more stringent validation on the
ICMP's packet payload. This knob is useful for people who e.g. want to
run an unmodified DNS server in a namespace where they need to use pmtu
for TCP connections (as they are used for zone transfers or fallback
for requests) but don't want to use possibly spoofed UDP pmtu information.

Currently the whitelisted protocols are TCP, SCTP and DCCP as they check
if the returned packet is in the window or if the association is valid.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: John Heffner &lt;johnwheffner@gmail.com&gt;
Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This new ip_no_pmtu_disc mode only allowes fragmentation-needed errors
to be honored by protocols which do more stringent validation on the
ICMP's packet payload. This knob is useful for people who e.g. want to
run an unmodified DNS server in a namespace where they need to use pmtu
for TCP connections (as they are used for zone transfers or fallback
for requests) but don't want to use possibly spoofed UDP pmtu information.

Currently the whitelisted protocols are TCP, SCTP and DCCP as they check
if the returned packet is in the window or if the association is valid.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: John Heffner &lt;johnwheffner@gmail.com&gt;
Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2014-01-06T22:37:45+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2014-01-06T22:37:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=56a4342dfe3145cd66f766adccb28fd9b571606d'/>
<id>56a4342dfe3145cd66f766adccb28fd9b571606d</id>
<content type='text'>
Conflicts:
	drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
	net/ipv6/ip6_tunnel.c
	net/ipv6/ip6_vti.c

ipv6 tunnel statistic bug fixes conflicting with consolidation into
generic sw per-cpu net stats.

qlogic conflict between queue counting bug fix and the addition
of multiple MAC address support.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
	net/ipv6/ip6_tunnel.c
	net/ipv6/ip6_vti.c

ipv6 tunnel statistic bug fixes conflicting with consolidation into
generic sw per-cpu net stats.

qlogic conflict between queue counting bug fix and the addition
of multiple MAC address support.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dccp: make local variable static</title>
<updated>2014-01-05T01:18:50+00:00</updated>
<author>
<name>stephen hemminger</name>
<email>stephen@networkplumber.org</email>
</author>
<published>2014-01-04T21:46:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6aee49c558de39eaf9100652bc9595f5a34200d9'/>
<id>6aee49c558de39eaf9100652bc9595f5a34200d9</id>
<content type='text'>
Make DCCP module config variable static, only used in one file.

Signed-off-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make DCCP module config variable static, only used in one file.

Signed-off-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dccp: remove obsolete code</title>
<updated>2014-01-05T01:18:49+00:00</updated>
<author>
<name>stephen hemminger</name>
<email>stephen@networkplumber.org</email>
</author>
<published>2014-01-04T21:46:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fd34d627aee8f32d6e54fdc0347be7a18e2d65ee'/>
<id>fd34d627aee8f32d6e54fdc0347be7a18e2d65ee</id>
<content type='text'>
This function is defined but not used.
Remove it now, can be resurrected if ever needed.

Signed-off-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This function is defined but not used.
Remove it now, can be resurrected if ever needed.

Signed-off-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dccp: catch failed request_module call in dccp_probe init</title>
<updated>2013-12-20T00:25:50+00:00</updated>
<author>
<name>Wang Weidong</name>
<email>wangweidong1@huawei.com</email>
</author>
<published>2013-12-18T02:24:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=965cdea825693c821d200e38fac9402cde6dce6a'/>
<id>965cdea825693c821d200e38fac9402cde6dce6a</id>
<content type='text'>
Check the return value of request_module during dccp_probe initialisation,
bail out if that call fails.

Signed-off-by: Gerrit Renker &lt;gerrit@erg.abdn.ac.uk&gt;
Signed-off-by: Wang Weidong &lt;wangweidong1@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Check the return value of request_module during dccp_probe initialisation,
bail out if that call fails.

Signed-off-by: Gerrit Renker &lt;gerrit@erg.abdn.ac.uk&gt;
Signed-off-by: Wang Weidong &lt;wangweidong1@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next</title>
<updated>2013-12-19T23:37:49+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2013-12-19T23:37:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1669cb9855050fe9d2a13391846f9aceccf42559'/>
<id>1669cb9855050fe9d2a13391846f9aceccf42559</id>
<content type='text'>
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2013-12-19

1) Use the user supplied policy index instead of a generated one
   if present. From Fan Du.

2) Make xfrm migration namespace aware. From Fan Du.

3) Make the xfrm state and policy locks namespace aware. From Fan Du.

4) Remove ancient sleeping when the SA is in acquire state,
   we now queue packets to the policy instead. This replaces the
   sleeping code.

5) Remove FLOWI_FLAG_CAN_SLEEP. This was used to notify xfrm about the
   posibility to sleep. The sleeping code is gone, so remove it.

6) Check user specified spi for IPComp. Thr spi for IPcomp is only
   16 bit wide, so check for a valid value. From Fan Du.

7) Export verify_userspi_info to check for valid user supplied spi ranges
   with pfkey and netlink. From Fan Du.

8) RFC3173 states that if the total size of a compressed payload and the IPComp
   header is not smaller than the size of the original payload, the IP datagram
   must be sent in the original non-compressed form. These packets are dropped
   by the inbound policy check because they are not transformed. Document the need
   to set 'level use' for IPcomp to receive such packets anyway. From Fan Du.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2013-12-19

1) Use the user supplied policy index instead of a generated one
   if present. From Fan Du.

2) Make xfrm migration namespace aware. From Fan Du.

3) Make the xfrm state and policy locks namespace aware. From Fan Du.

4) Remove ancient sleeping when the SA is in acquire state,
   we now queue packets to the policy instead. This replaces the
   sleeping code.

5) Remove FLOWI_FLAG_CAN_SLEEP. This was used to notify xfrm about the
   posibility to sleep. The sleeping code is gone, so remove it.

6) Check user specified spi for IPComp. Thr spi for IPcomp is only
   16 bit wide, so check for a valid value. From Fan Du.

7) Export verify_userspi_info to check for valid user supplied spi ranges
   with pfkey and netlink. From Fan Du.

8) RFC3173 states that if the total size of a compressed payload and the IPComp
   header is not smaller than the size of the original payload, the IP datagram
   must be sent in the original non-compressed form. These packets are dropped
   by the inbound policy check because they are not transformed. Document the need
   to set 'level use' for IPcomp to receive such packets anyway. From Fan Du.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: support IPV6_PMTU_INTERFACE on sockets</title>
<updated>2013-12-18T22:37:05+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2013-12-15T02:41:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=93b36cf3425b9bd9c56df7680fb237686b9c82ae'/>
<id>93b36cf3425b9bd9c56df7680fb237686b9c82ae</id>
<content type='text'>
IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it
nontheless for symmetry with IPv4 sockets. Also drop incoming MTU
information if this mode is enabled.

The additional bit in ipv6_pinfo just eats in the padding behind the
bitfield. There are no changes to the layout of the struct at all.

Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it
nontheless for symmetry with IPv4 sockets. Also drop incoming MTU
information if this mode is enabled.

The additional bit in ipv6_pinfo just eats in the padding behind the
bitfield. There are no changes to the layout of the struct at all.

Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: do not erase dst address with flow label destination</title>
<updated>2013-12-11T03:51:00+00:00</updated>
<author>
<name>Florent Fourcot</name>
<email>florent.fourcot@enst-bretagne.fr</email>
</author>
<published>2013-12-10T14:15:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ce7a3bdf18a8dbcba1409f5d335c56fde432ca89'/>
<id>ce7a3bdf18a8dbcba1409f5d335c56fde432ca89</id>
<content type='text'>
This patch is following b579035ff766c9412e2b92abf5cab794bff102b6
	"ipv6: remove old conditions on flow label sharing"

Since there is no reason to restrict a label to a
destination, we should not erase the destination value of a
socket with the value contained in the flow label storage.

This patch allows to really have the same flow label to more
than one destination.

Signed-off-by: Florent Fourcot &lt;florent.fourcot@enst-bretagne.fr&gt;
Reviewed-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch is following b579035ff766c9412e2b92abf5cab794bff102b6
	"ipv6: remove old conditions on flow label sharing"

Since there is no reason to restrict a label to a
destination, we should not erase the destination value of a
socket with the value contained in the flow label storage.

This patch allows to really have the same flow label to more
than one destination.

Signed-off-by: Florent Fourcot &lt;florent.fourcot@enst-bretagne.fr&gt;
Reviewed-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Remove FLOWI_FLAG_CAN_SLEEP</title>
<updated>2013-12-06T06:24:39+00:00</updated>
<author>
<name>Steffen Klassert</name>
<email>steffen.klassert@secunet.com</email>
</author>
<published>2013-08-28T06:04:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0e0d44ab4275549998567cd4700b43f7496eb62b'/>
<id>0e0d44ab4275549998567cd4700b43f7496eb62b</id>
<content type='text'>
FLOWI_FLAG_CAN_SLEEP was used to notify xfrm about the posibility
to sleep until the needed states are resolved. This code is gone,
so FLOWI_FLAG_CAN_SLEEP is not needed anymore.

Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
FLOWI_FLAG_CAN_SLEEP was used to notify xfrm about the posibility
to sleep until the needed states are resolved. This code is gone,
so FLOWI_FLAG_CAN_SLEEP is not needed anymore.

Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv4: introduce new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE</title>
<updated>2013-11-06T02:52:27+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2013-11-05T01:24:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=482fc6094afad572a4ea1fd722e7b11ca72022a0'/>
<id>482fc6094afad572a4ea1fd722e7b11ca72022a0</id>
<content type='text'>
Sockets marked with IP_PMTUDISC_INTERFACE won't do path mtu discovery,
their sockets won't accept and install new path mtu information and they
will always use the interface mtu for outgoing packets. It is guaranteed
that the packet is not fragmented locally. But we won't set the DF-Flag
on the outgoing frames.

Florian Weimer had the idea to use this flag to ensure DNS servers are
never generating outgoing fragments. They may well be fragmented on the
path, but the server never stores or usees path mtu values, which could
well be forged in an attack.

(The root of the problem with path MTU discovery is that there is
no reliable way to authenticate ICMP Fragmentation Needed But DF Set
messages because they are sent from intermediate routers with their
source addresses, and the IMCP payload will not always contain sufficient
information to identify a flow.)

Recent research in the DNS community showed that it is possible to
implement an attack where DNS cache poisoning is feasible by spoofing
fragments. This work was done by Amir Herzberg and Haya Shulman:
&lt;https://sites.google.com/site/hayashulman/files/fragmentation-poisoning.pdf&gt;

This issue was previously discussed among the DNS community, e.g.
&lt;http://www.ietf.org/mail-archive/web/dnsext/current/msg01204.html&gt;,
without leading to fixes.

This patch depends on the patch "ipv4: fix DO and PROBE pmtu mode
regarding local fragmentation with UFO/CORK" for the enforcement of the
non-fragmentable checks. If other users than ip_append_page/data should
use this semantic too, we have to add a new flag to IPCB(skb)-&gt;flags to
suppress local fragmentation and check for this in ip_finish_output.

Many thanks to Florian Weimer for the idea and feedback while implementing
this patch.

Cc: David S. Miller &lt;davem@davemloft.net&gt;
Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sockets marked with IP_PMTUDISC_INTERFACE won't do path mtu discovery,
their sockets won't accept and install new path mtu information and they
will always use the interface mtu for outgoing packets. It is guaranteed
that the packet is not fragmented locally. But we won't set the DF-Flag
on the outgoing frames.

Florian Weimer had the idea to use this flag to ensure DNS servers are
never generating outgoing fragments. They may well be fragmented on the
path, but the server never stores or usees path mtu values, which could
well be forged in an attack.

(The root of the problem with path MTU discovery is that there is
no reliable way to authenticate ICMP Fragmentation Needed But DF Set
messages because they are sent from intermediate routers with their
source addresses, and the IMCP payload will not always contain sufficient
information to identify a flow.)

Recent research in the DNS community showed that it is possible to
implement an attack where DNS cache poisoning is feasible by spoofing
fragments. This work was done by Amir Herzberg and Haya Shulman:
&lt;https://sites.google.com/site/hayashulman/files/fragmentation-poisoning.pdf&gt;

This issue was previously discussed among the DNS community, e.g.
&lt;http://www.ietf.org/mail-archive/web/dnsext/current/msg01204.html&gt;,
without leading to fixes.

This patch depends on the patch "ipv4: fix DO and PROBE pmtu mode
regarding local fragmentation with UFO/CORK" for the enforcement of the
non-fragmentable checks. If other users than ip_append_page/data should
use this semantic too, we have to add a new flag to IPCB(skb)-&gt;flags to
suppress local fragmentation and check for this in ip_finish_output.

Many thanks to Florian Weimer for the idea and feedback while implementing
this patch.

Cc: David S. Miller &lt;davem@davemloft.net&gt;
Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
