<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/netfilter/ipvs, branch v6.6-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux</title>
<updated>2023-08-30T00:39:15+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-08-30T00:39:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=adfd671676c922bada16477eb68b5eb5f065addc'/>
<id>adfd671676c922bada16477eb68b5eb5f065addc</id>
<content type='text'>
Pull sysctl updates from Luis Chamberlain:
 "Long ago we set out to remove the kitchen sink on kernel/sysctl.c
  arrays and placings sysctls to their own sybsystem or file to help
  avoid merge conflicts. Matthew Wilcox pointed out though that if we're
  going to do that we might as well also *save* space while at it and
  try to remove the extra last sysctl entry added at the end of each
  array, a sentintel, instead of bloating the kernel by adding a new
  sentinel with each array moved.

  Doing that was not so trivial, and has required slowing down the moves
  of kernel/sysctl.c arrays and measuring the impact on size by each new
  move.

  The complex part of the effort to help reduce the size of each sysctl
  is being done by the patient work of el señor Don Joel Granados. A lot
  of this is truly painful code refactoring and testing and then trying
  to measure the savings of each move and removing the sentinels.
  Although Joel already has code which does most of this work,
  experience with sysctl moves in the past shows is we need to be
  careful due to the slew of odd build failures that are possible due to
  the amount of random Kconfig options sysctls use.

  To that end Joel's work is split by first addressing the major
  housekeeping needed to remove the sentinels, which is part of this
  merge request. The rest of the work to actually remove the sentinels
  will be done later in future kernel releases.

  The preliminary math is showing this will all help reduce the overall
  build time size of the kernel and run time memory consumed by the
  kernel by about ~64 bytes per array where we are able to remove each
  sentinel in the future. That also means there is no more bloating the
  kernel with the extra ~64 bytes per array moved as no new sentinels
  are created"

* tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: Use ctl_table_size as stopping criteria for list macro
  sysctl: SIZE_MAX-&gt;ARRAY_SIZE in register_net_sysctl
  vrf: Update to register_net_sysctl_sz
  networking: Update to register_net_sysctl_sz
  netfilter: Update to register_net_sysctl_sz
  ax.25: Update to register_net_sysctl_sz
  sysctl: Add size to register_net_sysctl function
  sysctl: Add size arg to __register_sysctl_init
  sysctl: Add size to register_sysctl
  sysctl: Add a size arg to __register_sysctl_table
  sysctl: Add size argument to init_header
  sysctl: Add ctl_table_size to ctl_table_header
  sysctl: Use ctl_table_header in list_for_each_table_entry
  sysctl: Prefer ctl_table_header in proc_sysctl
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull sysctl updates from Luis Chamberlain:
 "Long ago we set out to remove the kitchen sink on kernel/sysctl.c
  arrays and placings sysctls to their own sybsystem or file to help
  avoid merge conflicts. Matthew Wilcox pointed out though that if we're
  going to do that we might as well also *save* space while at it and
  try to remove the extra last sysctl entry added at the end of each
  array, a sentintel, instead of bloating the kernel by adding a new
  sentinel with each array moved.

  Doing that was not so trivial, and has required slowing down the moves
  of kernel/sysctl.c arrays and measuring the impact on size by each new
  move.

  The complex part of the effort to help reduce the size of each sysctl
  is being done by the patient work of el señor Don Joel Granados. A lot
  of this is truly painful code refactoring and testing and then trying
  to measure the savings of each move and removing the sentinels.
  Although Joel already has code which does most of this work,
  experience with sysctl moves in the past shows is we need to be
  careful due to the slew of odd build failures that are possible due to
  the amount of random Kconfig options sysctls use.

  To that end Joel's work is split by first addressing the major
  housekeeping needed to remove the sentinels, which is part of this
  merge request. The rest of the work to actually remove the sentinels
  will be done later in future kernel releases.

  The preliminary math is showing this will all help reduce the overall
  build time size of the kernel and run time memory consumed by the
  kernel by about ~64 bytes per array where we are able to remove each
  sentinel in the future. That also means there is no more bloating the
  kernel with the extra ~64 bytes per array moved as no new sentinels
  are created"

* tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: Use ctl_table_size as stopping criteria for list macro
  sysctl: SIZE_MAX-&gt;ARRAY_SIZE in register_net_sysctl
  vrf: Update to register_net_sysctl_sz
  networking: Update to register_net_sysctl_sz
  netfilter: Update to register_net_sysctl_sz
  ax.25: Update to register_net_sysctl_sz
  sysctl: Add size to register_net_sysctl function
  sysctl: Add size arg to __register_sysctl_init
  sysctl: Add size to register_sysctl
  sysctl: Add a size arg to __register_sysctl_table
  sysctl: Add size argument to init_header
  sysctl: Add ctl_table_size to ctl_table_header
  sysctl: Use ctl_table_header in list_for_each_table_entry
  sysctl: Prefer ctl_table_header in proc_sysctl
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-08-18T19:44:56+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-08-18T19:44:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7ff57803d24e0cb326251489d70f60462e3e6c04'/>
<id>7ff57803d24e0cb326251489d70f60462e3e6c04</id>
<content type='text'>
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/sfc/tc.c
  fa165e194997 ("sfc: don't unregister flow_indr if it was never registered")
  3bf969e88ada ("sfc: add MAE table machinery for conntrack table")
https://lore.kernel.org/all/20230818112159.7430e9b4@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/sfc/tc.c
  fa165e194997 ("sfc: don't unregister flow_indr if it was never registered")
  3bf969e88ada ("sfc: add MAE table machinery for conntrack table")
https://lore.kernel.org/all/20230818112159.7430e9b4@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>inet: move inet-&gt;nodefrag to inet-&gt;inet_flags</title>
<updated>2023-08-16T10:09:17+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-08-16T08:15:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f04b8d3478a3a63f17d8dc0dc6da16a828b48df0'/>
<id>f04b8d3478a3a63f17d8dc0dc6da16a828b48df0</id>
<content type='text'>
IP_NODEFRAG socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Soheil Hassas Yeganeh &lt;soheil@google.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.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>
IP_NODEFRAG socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Soheil Hassas Yeganeh &lt;soheil@google.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>inet: move inet-&gt;mc_loop to inet-&gt;inet_frags</title>
<updated>2023-08-16T10:09:17+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-08-16T08:15:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b09bde5c3554d58cb711dac55a10ecc56d436966'/>
<id>b09bde5c3554d58cb711dac55a10ecc56d436966</id>
<content type='text'>
IP_MULTICAST_LOOP socket option can now be set/read
without locking the socket.

v3: fix build bot error reported in ipvs set_mcast_loop()

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Soheil Hassas Yeganeh &lt;soheil@google.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.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>
IP_MULTICAST_LOOP socket option can now be set/read
without locking the socket.

v3: fix build bot error reported in ipvs set_mcast_loop()

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Soheil Hassas Yeganeh &lt;soheil@google.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: Update to register_net_sysctl_sz</title>
<updated>2023-08-15T22:26:17+00:00</updated>
<author>
<name>Joel Granados</name>
<email>joel.granados@gmail.com</email>
</author>
<published>2023-08-09T10:50:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=385a5dc9e578bdc43bf5196258f699f08612379b'/>
<id>385a5dc9e578bdc43bf5196258f699f08612379b</id>
<content type='text'>
Move from register_net_sysctl to register_net_sysctl_sz for all the
netfilter related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Joel Granados &lt;j.granados@samsung.com&gt;
Signed-off-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move from register_net_sysctl to register_net_sysctl_sz for all the
netfilter related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Joel Granados &lt;j.granados@samsung.com&gt;
Signed-off-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: fix racy memcpy in proc_do_sync_threshold</title>
<updated>2023-08-15T22:05:15+00:00</updated>
<author>
<name>Sishuai Gong</name>
<email>sishuai.system@gmail.com</email>
</author>
<published>2023-08-10T19:12:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5310760af1d4fbea1452bfc77db5f9a680f7ae47'/>
<id>5310760af1d4fbea1452bfc77db5f9a680f7ae47</id>
<content type='text'>
When two threads run proc_do_sync_threshold() in parallel,
data races could happen between the two memcpy():

Thread-1			Thread-2
memcpy(val, valp, sizeof(val));
				memcpy(valp, val, sizeof(val));

This race might mess up the (struct ctl_table *) table-&gt;data,
so we add a mutex lock to serialize them.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/netdev/B6988E90-0A1E-4B85-BF26-2DAF6D482433@gmail.com/
Signed-off-by: Sishuai Gong &lt;sishuai.system@gmail.com&gt;
Acked-by: Simon Horman &lt;horms@kernel.org&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When two threads run proc_do_sync_threshold() in parallel,
data races could happen between the two memcpy():

Thread-1			Thread-2
memcpy(val, valp, sizeof(val));
				memcpy(valp, val, sizeof(val));

This race might mess up the (struct ctl_table *) table-&gt;data,
so we add a mutex lock to serialize them.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/netdev/B6988E90-0A1E-4B85-BF26-2DAF6D482433@gmail.com/
Signed-off-by: Sishuai Gong &lt;sishuai.system@gmail.com&gt;
Acked-by: Simon Horman &lt;horms@kernel.org&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'nf-next-23-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next</title>
<updated>2023-06-26T19:59:18+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-06-26T19:59:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=61dc651cdfe85066e1371dd1bd8aee685bd6ec75'/>
<id>61dc651cdfe85066e1371dd1bd8aee685bd6ec75</id>
<content type='text'>
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

1) Allow slightly larger IPVS connection table size from Kconfig for
   64-bit arch, from Abhijeet Rastogi.

2) Since IPVS connection table might be larger than 2^20 after previous
   patch, allow to limit it depending on the available memory.
   Moreover, use kvmalloc. From Julian Anastasov.

3) Do not rebuild VLAN header in nft_payload when matching source and
   destination MAC address.

4) Remove nested rcu read lock side in ip_set_test(), from Florian Westphal.

5) Allow to update set size, also from Florian.

6) Improve NAT tuple selection when connection is closing,
   from Florian Westphal.

7) Support for resetting set element stateful expression, from Phil Sutter.

8) Use NLA_POLICY_MAX to narrow down maximum attribute value in nf_tables,
   from Florian Westphal.

* tag 'nf-next-23-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: limit allowed range via nla_policy
  netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET
  netfilter: snat: evict closing tcp entries on reply tuple collision
  netfilter: nf_tables: permit update of set size
  netfilter: ipset: remove rcu_read_lock_bh pair from ip_set_test
  netfilter: nft_payload: rebuild vlan header when needed
  ipvs: dynamically limit the connection hash table
  ipvs: increase ip_vs_conn_tab_bits range for 64BIT
====================

Link: https://lore.kernel.org/r/20230626064749.75525-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

1) Allow slightly larger IPVS connection table size from Kconfig for
   64-bit arch, from Abhijeet Rastogi.

2) Since IPVS connection table might be larger than 2^20 after previous
   patch, allow to limit it depending on the available memory.
   Moreover, use kvmalloc. From Julian Anastasov.

3) Do not rebuild VLAN header in nft_payload when matching source and
   destination MAC address.

4) Remove nested rcu read lock side in ip_set_test(), from Florian Westphal.

5) Allow to update set size, also from Florian.

6) Improve NAT tuple selection when connection is closing,
   from Florian Westphal.

7) Support for resetting set element stateful expression, from Phil Sutter.

8) Use NLA_POLICY_MAX to narrow down maximum attribute value in nf_tables,
   from Florian Westphal.

* tag 'nf-next-23-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: limit allowed range via nla_policy
  netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET
  netfilter: snat: evict closing tcp entries on reply tuple collision
  netfilter: nf_tables: permit update of set size
  netfilter: ipset: remove rcu_read_lock_bh pair from ip_set_test
  netfilter: nft_payload: rebuild vlan header when needed
  ipvs: dynamically limit the connection hash table
  ipvs: increase ip_vs_conn_tab_bits range for 64BIT
====================

Link: https://lore.kernel.org/r/20230626064749.75525-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-06-23T01:40:38+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-06-23T01:40:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a7384f3918756c193e3fcd7e3111fc4bd3686013'/>
<id>a7384f3918756c193e3fcd7e3111fc4bd3686013</id>
<content type='text'>
Cross-merge networking fixes after downstream PR.

Conflicts:

tools/testing/selftests/net/fcnal-test.sh
  d7a2fc1437f7 ("selftests: net: fcnal-test: check if FIPS mode is enabled")
  dd017c72dde6 ("selftests: fcnal: Test SO_DONTROUTE on TCP sockets.")
https://lore.kernel.org/all/5007b52c-dd16-dbf6-8d64-b9701bfa498b@tessares.net/
https://lore.kernel.org/all/20230619105427.4a0df9b3@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cross-merge networking fixes after downstream PR.

Conflicts:

tools/testing/selftests/net/fcnal-test.sh
  d7a2fc1437f7 ("selftests: net: fcnal-test: check if FIPS mode is enabled")
  dd017c72dde6 ("selftests: fcnal: Test SO_DONTROUTE on TCP sockets.")
https://lore.kernel.org/all/5007b52c-dd16-dbf6-8d64-b9701bfa498b@tessares.net/
https://lore.kernel.org/all/20230619105427.4a0df9b3@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: align inner_mac_header for encapsulation</title>
<updated>2023-06-19T14:01:07+00:00</updated>
<author>
<name>Terin Stock</name>
<email>terin@cloudflare.com</email>
</author>
<published>2023-06-09T20:58:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d7fce52fdf96663ddc2eb21afecff3775588612a'/>
<id>d7fce52fdf96663ddc2eb21afecff3775588612a</id>
<content type='text'>
When using encapsulation the original packet's headers are copied to the
inner headers. This preserves the space for an inner mac header, which
is not used by the inner payloads for the encapsulation types supported
by IPVS. If a packet is using GUE or GRE encapsulation and needs to be
segmented, flow can be passed to __skb_udp_tunnel_segment() which
calculates a negative tunnel header length. A negative tunnel header
length causes pskb_may_pull() to fail, dropping the packet.

This can be observed by attaching probes to ip_vs_in_hook(),
__dev_queue_xmit(), and __skb_udp_tunnel_segment():

    perf probe --add '__dev_queue_xmit skb-&gt;inner_mac_header \
    skb-&gt;inner_network_header skb-&gt;mac_header skb-&gt;network_header'
    perf probe --add '__skb_udp_tunnel_segment:7 tnl_hlen'
    perf probe -m ip_vs --add 'ip_vs_in_hook skb-&gt;inner_mac_header \
    skb-&gt;inner_network_header skb-&gt;mac_header skb-&gt;network_header'

These probes the headers and tunnel header length for packets which
traverse the IPVS encapsulation path. A TCP packet can be forced into
the segmentation path by being smaller than a calculated clamped MSS,
but larger than the advertised MSS.

    probe:ip_vs_in_hook: inner_mac_header=0x0 inner_network_header=0x0 mac_header=0x44 network_header=0x52
    probe:ip_vs_in_hook: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
    probe:dev_queue_xmit: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
    probe:__skb_udp_tunnel_segment_L7: tnl_hlen=-2

When using veth-based encapsulation, the interfaces are set to be
mac-less, which does not preserve space for an inner mac header. This
prevents this issue from occurring.

In our real-world testing of sending a 32KB file we observed operation
time increasing from ~75ms for veth-based encapsulation to over 1.5s
using IPVS encapsulation due to retries from dropped packets.

This changeset modifies the packet on the encapsulation path in
ip_vs_tunnel_xmit() and ip_vs_tunnel_xmit_v6() to remove the inner mac
header offset. This fixes UDP segmentation for both encapsulation types,
and corrects the inner headers for any IPIP flows that may use it.

Fixes: 84c0d5e96f3a ("ipvs: allow tunneling with gue encapsulation")
Signed-off-by: Terin Stock &lt;terin@cloudflare.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Acked-by: Simon Horman &lt;horms@kernel.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When using encapsulation the original packet's headers are copied to the
inner headers. This preserves the space for an inner mac header, which
is not used by the inner payloads for the encapsulation types supported
by IPVS. If a packet is using GUE or GRE encapsulation and needs to be
segmented, flow can be passed to __skb_udp_tunnel_segment() which
calculates a negative tunnel header length. A negative tunnel header
length causes pskb_may_pull() to fail, dropping the packet.

This can be observed by attaching probes to ip_vs_in_hook(),
__dev_queue_xmit(), and __skb_udp_tunnel_segment():

    perf probe --add '__dev_queue_xmit skb-&gt;inner_mac_header \
    skb-&gt;inner_network_header skb-&gt;mac_header skb-&gt;network_header'
    perf probe --add '__skb_udp_tunnel_segment:7 tnl_hlen'
    perf probe -m ip_vs --add 'ip_vs_in_hook skb-&gt;inner_mac_header \
    skb-&gt;inner_network_header skb-&gt;mac_header skb-&gt;network_header'

These probes the headers and tunnel header length for packets which
traverse the IPVS encapsulation path. A TCP packet can be forced into
the segmentation path by being smaller than a calculated clamped MSS,
but larger than the advertised MSS.

    probe:ip_vs_in_hook: inner_mac_header=0x0 inner_network_header=0x0 mac_header=0x44 network_header=0x52
    probe:ip_vs_in_hook: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
    probe:dev_queue_xmit: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
    probe:__skb_udp_tunnel_segment_L7: tnl_hlen=-2

When using veth-based encapsulation, the interfaces are set to be
mac-less, which does not preserve space for an inner mac header. This
prevents this issue from occurring.

In our real-world testing of sending a 32KB file we observed operation
time increasing from ~75ms for veth-based encapsulation to over 1.5s
using IPVS encapsulation due to retries from dropped packets.

This changeset modifies the packet on the encapsulation path in
ip_vs_tunnel_xmit() and ip_vs_tunnel_xmit_v6() to remove the inner mac
header offset. This fixes UDP segmentation for both encapsulation types,
and corrects the inner headers for any IPIP flows that may use it.

Fixes: 84c0d5e96f3a ("ipvs: allow tunneling with gue encapsulation")
Signed-off-by: Terin Stock &lt;terin@cloudflare.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Acked-by: Simon Horman &lt;horms@kernel.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
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</entry>
<entry>
<title>ipv4: Drop tos parameter from flowi4_update_output()</title>
<updated>2023-06-02T09:52:38+00:00</updated>
<author>
<name>Guillaume Nault</name>
<email>gnault@redhat.com</email>
</author>
<published>2023-06-01T16:37:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3f06760c00f56c5fe6c7f3361c2cf64becee1174'/>
<id>3f06760c00f56c5fe6c7f3361c2cf64becee1174</id>
<content type='text'>
Callers of flowi4_update_output() never try to update -&gt;flowi4_tos:

  * ip_route_connect() updates -&gt;flowi4_tos with its own current
    value.

  * ip_route_newports() has two users: tcp_v4_connect() and
    dccp_v4_connect. Both initialise fl4 with ip_route_connect(), which
    in turn sets -&gt;flowi4_tos with RT_TOS(inet_sk(sk)-&gt;tos) and
    -&gt;flowi4_scope based on SOCK_LOCALROUTE.

    Then ip_route_newports() updates -&gt;flowi4_tos with
    RT_CONN_FLAGS(sk), which is the same as RT_TOS(inet_sk(sk)-&gt;tos),
    unless SOCK_LOCALROUTE is set on the socket. In that case, the
    lowest order bit is set to 1, to eventually inform
    ip_route_output_key_hash() to restrict the scope to RT_SCOPE_LINK.
    This is equivalent to properly setting -&gt;flowi4_scope as
    ip_route_connect() did.

  * ip_vs_xmit.c initialises -&gt;flowi4_tos with memset(0), then calls
    flowi4_update_output() with tos=0.

  * sctp_v4_get_dst() uses the same RT_CONN_FLAGS_TOS() when
    initialising -&gt;flowi4_tos and when calling flowi4_update_output().

In the end, -&gt;flowi4_tos never changes. So let's just drop the tos
parameter. This will simplify the conversion of -&gt;flowi4_tos from __u8
to dscp_t.

Signed-off-by: Guillaume Nault &lt;gnault@redhat.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>
Callers of flowi4_update_output() never try to update -&gt;flowi4_tos:

  * ip_route_connect() updates -&gt;flowi4_tos with its own current
    value.

  * ip_route_newports() has two users: tcp_v4_connect() and
    dccp_v4_connect. Both initialise fl4 with ip_route_connect(), which
    in turn sets -&gt;flowi4_tos with RT_TOS(inet_sk(sk)-&gt;tos) and
    -&gt;flowi4_scope based on SOCK_LOCALROUTE.

    Then ip_route_newports() updates -&gt;flowi4_tos with
    RT_CONN_FLAGS(sk), which is the same as RT_TOS(inet_sk(sk)-&gt;tos),
    unless SOCK_LOCALROUTE is set on the socket. In that case, the
    lowest order bit is set to 1, to eventually inform
    ip_route_output_key_hash() to restrict the scope to RT_SCOPE_LINK.
    This is equivalent to properly setting -&gt;flowi4_scope as
    ip_route_connect() did.

  * ip_vs_xmit.c initialises -&gt;flowi4_tos with memset(0), then calls
    flowi4_update_output() with tos=0.

  * sctp_v4_get_dst() uses the same RT_CONN_FLAGS_TOS() when
    initialising -&gt;flowi4_tos and when calling flowi4_update_output().

In the end, -&gt;flowi4_tos never changes. So let's just drop the tos
parameter. This will simplify the conversion of -&gt;flowi4_tos from __u8
to dscp_t.

Signed-off-by: Guillaume Nault &lt;gnault@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
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