<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/Documentation/networking, branch linux-6.14.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>tcp: be less liberal in TSEcr received while in SYN_RECV state</title>
<updated>2025-05-29T09:13:05+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2025-02-25T17:10:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7967b84909e5ebcd5273b393e48d6ba8075306db'/>
<id>7967b84909e5ebcd5273b393e48d6ba8075306db</id>
<content type='text'>
[ Upstream commit 3ba075278c11cdb19e2dbb80362042f1b0c08f74 ]

Yong-Hao Zou mentioned that linux was not strict as other OS in 3WHS,
for flows using TCP TS option (RFC 7323)

As hinted by an old comment in tcp_check_req(),
we can check the TSEcr value in the incoming packet corresponds
to one of the SYNACK TSval values we have sent.

In this patch, I record the oldest and most recent values
that SYNACK packets have used.

Send a challenge ACK if we receive a TSEcr outside
of this range, and increase a new SNMP counter.

nstat -az | grep TSEcrRejected
TcpExtTSEcrRejected            0                  0.0

Due to TCP fastopen implementation, do not apply yet these checks
for fastopen flows.

v2: No longer use req-&gt;num_timeout, but treq-&gt;snt_tsval_first
    to detect when first SYNACK is prepared. This means
    we make sure to not send an initial zero TSval.
    Make sure MPTCP and TCP selftests are passing.
    Change MIB name to TcpExtTSEcrRejected

v1: https://lore.kernel.org/netdev/CADVnQykD8i4ArpSZaPKaoNxLJ2if2ts9m4As+=Jvdkrgx1qMHw@mail.gmail.com/T/

Reported-by: Yong-Hao Zou &lt;yonghaoz1994@gmail.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Reviewed-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Link: https://patch.msgid.link/20250225171048.3105061-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3ba075278c11cdb19e2dbb80362042f1b0c08f74 ]

Yong-Hao Zou mentioned that linux was not strict as other OS in 3WHS,
for flows using TCP TS option (RFC 7323)

As hinted by an old comment in tcp_check_req(),
we can check the TSEcr value in the incoming packet corresponds
to one of the SYNACK TSval values we have sent.

In this patch, I record the oldest and most recent values
that SYNACK packets have used.

Send a challenge ACK if we receive a TSEcr outside
of this range, and increase a new SNMP counter.

nstat -az | grep TSEcrRejected
TcpExtTSEcrRejected            0                  0.0

Due to TCP fastopen implementation, do not apply yet these checks
for fastopen flows.

v2: No longer use req-&gt;num_timeout, but treq-&gt;snt_tsval_first
    to detect when first SYNACK is prepared. This means
    we make sure to not send an initial zero TSval.
    Make sure MPTCP and TCP selftests are passing.
    Change MIB name to TcpExtTSEcrRejected

v1: https://lore.kernel.org/netdev/CADVnQykD8i4ArpSZaPKaoNxLJ2if2ts9m4As+=Jvdkrgx1qMHw@mail.gmail.com/T/

Reported-by: Yong-Hao Zou &lt;yonghaoz1994@gmail.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Reviewed-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Link: https://patch.msgid.link/20250225171048.3105061-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xsk: Add launch time hardware offload support to XDP Tx metadata</title>
<updated>2025-04-10T12:44:39+00:00</updated>
<author>
<name>Song Yoong Siang</name>
<email>yoong.siang.song@intel.com</email>
</author>
<published>2025-02-16T09:34:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d9d736c416c9a85f84e15435ba82a177262e745b'/>
<id>d9d736c416c9a85f84e15435ba82a177262e745b</id>
<content type='text'>
[ Upstream commit ca4419f15abd19ba8be1e109661b60f9f5b6c9f0 ]

Extend the XDP Tx metadata framework so that user can requests launch time
hardware offload, where the Ethernet device will schedule the packet for
transmission at a pre-determined time called launch time. The value of
launch time is communicated from user space to Ethernet driver via
launch_time field of struct xsk_tx_metadata.

Suggested-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Signed-off-by: Song Yoong Siang &lt;yoong.siang.song@intel.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Acked-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://patch.msgid.link/20250216093430.957880-2-yoong.siang.song@intel.com
Stable-dep-of: d931cf9b38da ("igc: Fix TX drops in XDP ZC")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ca4419f15abd19ba8be1e109661b60f9f5b6c9f0 ]

Extend the XDP Tx metadata framework so that user can requests launch time
hardware offload, where the Ethernet device will schedule the packet for
transmission at a pre-determined time called launch time. The value of
launch time is communicated from user space to Ethernet driver via
launch_time field of struct xsk_tx_metadata.

Suggested-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Signed-off-by: Song Yoong Siang &lt;yoong.siang.song@intel.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Acked-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://patch.msgid.link/20250216093430.957880-2-yoong.siang.song@intel.com
Stable-dep-of: d931cf9b38da ("igc: Fix TX drops in XDP ZC")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2025-02-20T23:37:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-02-20T23:37:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=319fc77f8f45a1b3dba15b0cc1a869778fd222f7'/>
<id>319fc77f8f45a1b3dba15b0cc1a869778fd222f7</id>
<content type='text'>
Pull BPF fixes from Daniel Borkmann:

 - Fix a soft-lockup in BPF arena_map_free on 64k page size kernels
   (Alan Maguire)

 - Fix a missing allocation failure check in BPF verifier's
   acquire_lock_state (Kumar Kartikeya Dwivedi)

 - Fix a NULL-pointer dereference in trace_kfree_skb by adding kfree_skb
   to the raw_tp_null_args set (Kuniyuki Iwashima)

 - Fix a deadlock when freeing BPF cgroup storage (Abel Wu)

 - Fix a syzbot-reported deadlock when holding BPF map's freeze_mutex
   (Andrii Nakryiko)

 - Fix a use-after-free issue in bpf_test_init when eth_skb_pkt_type is
   accessing skb data not containing an Ethernet header (Shigeru
   Yoshida)

 - Fix skipping non-existing keys in generic_map_lookup_batch (Yan Zhai)

 - Several BPF sockmap fixes to address incorrect TCP copied_seq
   calculations, which prevented correct data reads from recv(2) in user
   space (Jiayuan Chen)

 - Two fixes for BPF map lookup nullness elision (Daniel Xu)

 - Fix a NULL-pointer dereference from vmlinux BTF lookup in
   bpf_sk_storage_tracing_allowed (Jared Kangas)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests: bpf: test batch lookup on array of maps with holes
  bpf: skip non exist keys in generic_map_lookup_batch
  bpf: Handle allocation failure in acquire_lock_state
  bpf: verifier: Disambiguate get_constant_map_key() errors
  bpf: selftests: Test constant key extraction on irrelevant maps
  bpf: verifier: Do not extract constant map keys for irrelevant maps
  bpf: Fix softlockup in arena_map_free on 64k page kernel
  net: Add rx_skb of kfree_skb to raw_tp_null_args[].
  bpf: Fix deadlock when freeing cgroup storage
  selftests/bpf: Add strparser test for bpf
  selftests/bpf: Fix invalid flag of recv()
  bpf: Disable non stream socket for strparser
  bpf: Fix wrong copied_seq calculation
  strparser: Add read_sock callback
  bpf: avoid holding freeze_mutex during mmap operation
  bpf: unify VM_WRITE vs VM_MAYWRITE use in BPF map mmaping logic
  selftests/bpf: Adjust data size to have ETH_HLEN
  bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()
  bpf: Remove unnecessary BTF lookups in bpf_sk_storage_tracing_allowed
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull BPF fixes from Daniel Borkmann:

 - Fix a soft-lockup in BPF arena_map_free on 64k page size kernels
   (Alan Maguire)

 - Fix a missing allocation failure check in BPF verifier's
   acquire_lock_state (Kumar Kartikeya Dwivedi)

 - Fix a NULL-pointer dereference in trace_kfree_skb by adding kfree_skb
   to the raw_tp_null_args set (Kuniyuki Iwashima)

 - Fix a deadlock when freeing BPF cgroup storage (Abel Wu)

 - Fix a syzbot-reported deadlock when holding BPF map's freeze_mutex
   (Andrii Nakryiko)

 - Fix a use-after-free issue in bpf_test_init when eth_skb_pkt_type is
   accessing skb data not containing an Ethernet header (Shigeru
   Yoshida)

 - Fix skipping non-existing keys in generic_map_lookup_batch (Yan Zhai)

 - Several BPF sockmap fixes to address incorrect TCP copied_seq
   calculations, which prevented correct data reads from recv(2) in user
   space (Jiayuan Chen)

 - Two fixes for BPF map lookup nullness elision (Daniel Xu)

 - Fix a NULL-pointer dereference from vmlinux BTF lookup in
   bpf_sk_storage_tracing_allowed (Jared Kangas)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests: bpf: test batch lookup on array of maps with holes
  bpf: skip non exist keys in generic_map_lookup_batch
  bpf: Handle allocation failure in acquire_lock_state
  bpf: verifier: Disambiguate get_constant_map_key() errors
  bpf: selftests: Test constant key extraction on irrelevant maps
  bpf: verifier: Do not extract constant map keys for irrelevant maps
  bpf: Fix softlockup in arena_map_free on 64k page kernel
  net: Add rx_skb of kfree_skb to raw_tp_null_args[].
  bpf: Fix deadlock when freeing cgroup storage
  selftests/bpf: Add strparser test for bpf
  selftests/bpf: Fix invalid flag of recv()
  bpf: Disable non stream socket for strparser
  bpf: Fix wrong copied_seq calculation
  strparser: Add read_sock callback
  bpf: avoid holding freeze_mutex during mmap operation
  bpf: unify VM_WRITE vs VM_MAYWRITE use in BPF map mmaping logic
  selftests/bpf: Adjust data size to have ETH_HLEN
  bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()
  bpf: Remove unnecessary BTF lookups in bpf_sk_storage_tracing_allowed
</pre>
</div>
</content>
</entry>
<entry>
<title>Documentation/networking: fix basic node example document ISO 15765-2</title>
<updated>2025-02-08T10:28:11+00:00</updated>
<author>
<name>Reyders Morales</name>
<email>reyders1@gmail.com</email>
</author>
<published>2025-02-03T22:47:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d0b197b6505fe3788860fc2a81b3ce53cbecc69c'/>
<id>d0b197b6505fe3788860fc2a81b3ce53cbecc69c</id>
<content type='text'>
In the current struct sockaddr_can tp is member of can_addr. tp is not
member of struct sockaddr_can.

Signed-off-by: Reyders Morales &lt;reyders1@gmail.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://patch.msgid.link/20250203224720.42530-1-reyders1@gmail.com
Fixes: 67711e04254c ("Documentation: networking: document ISO 15765-2")
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the current struct sockaddr_can tp is member of can_addr. tp is not
member of struct sockaddr_can.

Signed-off-by: Reyders Morales &lt;reyders1@gmail.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://patch.msgid.link/20250203224720.42530-1-reyders1@gmail.com
Fixes: 67711e04254c ("Documentation: networking: document ISO 15765-2")
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>doc: mptcp: sysctl: blackhole_timeout is per-netns</title>
<updated>2025-01-30T13:02:19+00:00</updated>
<author>
<name>Matthieu Baerts (NGI0)</name>
<email>matttbe@kernel.org</email>
</author>
<published>2025-01-29T12:24:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=18da4b5d123285dea470b15ff51c7fbe61dc37fd'/>
<id>18da4b5d123285dea470b15ff51c7fbe61dc37fd</id>
<content type='text'>
All other sysctl entries mention it, and it is a per-namespace sysctl.

So mention it as well.

Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole")
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All other sysctl entries mention it, and it is a per-namespace sysctl.

So mention it as well.

Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole")
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>strparser: Add read_sock callback</title>
<updated>2025-01-29T21:32:08+00:00</updated>
<author>
<name>Jiayuan Chen</name>
<email>mrpre@163.com</email>
</author>
<published>2025-01-22T10:09:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0532a79efd68a4d9686b0385e4993af4b130ff82'/>
<id>0532a79efd68a4d9686b0385e4993af4b130ff82</id>
<content type='text'>
Added a new read_sock handler, allowing users to customize read operations
instead of relying on the native socket's read_sock.

Signed-off-by: Jiayuan Chen &lt;mrpre@163.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Reviewed-by: Jakub Sitnicki &lt;jakub@cloudflare.com&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Link: https://patch.msgid.link/20250122100917.49845-2-mrpre@163.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Added a new read_sock handler, allowing users to customize read operations
instead of relying on the native socket's read_sock.

Signed-off-by: Jiayuan Chen &lt;mrpre@163.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Reviewed-by: Jakub Sitnicki &lt;jakub@cloudflare.com&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Link: https://patch.msgid.link/20250122100917.49845-2-mrpre@163.com
</pre>
</div>
</content>
</entry>
<entry>
<title>documentation: networking: fix spelling mistakes</title>
<updated>2025-01-27T22:26:06+00:00</updated>
<author>
<name>Khaled Elnaggar</name>
<email>khaledelnaggarlinux@gmail.com</email>
</author>
<published>2025-01-23T08:25:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cde5959913b713eecee44451c9bb3141e625a8d8'/>
<id>cde5959913b713eecee44451c9bb3141e625a8d8</id>
<content type='text'>
Fix a couple of typos/spelling mistakes in the documentation.

Signed-off-by: Khaled Elnaggar &lt;khaledelnaggarlinux@gmail.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Reviewed-by: Przemek Kitszel &lt;przemyslaw.kitszel@intel.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Bagas Sanjaya &lt;bagasdotme@gmail.com&gt;
Link: https://patch.msgid.link/20250123082521.59997-1-khaledelnaggarlinux@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix a couple of typos/spelling mistakes in the documentation.

Signed-off-by: Khaled Elnaggar &lt;khaledelnaggarlinux@gmail.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Reviewed-by: Przemek Kitszel &lt;przemyslaw.kitszel@intel.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Bagas Sanjaya &lt;bagasdotme@gmail.com&gt;
Link: https://patch.msgid.link/20250123082521.59997-1-khaledelnaggarlinux@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'batadv-next-pullrequest-20250117' of git://git.open-mesh.org/linux-merge</title>
<updated>2025-01-19T01:57:31+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2025-01-19T01:57:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59372af69d4d71e6487614f1b35712cf241eadb4'/>
<id>59372af69d4d71e6487614f1b35712cf241eadb4</id>
<content type='text'>
Simon Wunderlich says:

====================
This cleanup patchset includes the following patches:

 - bump version strings, by Simon Wunderlich

 - Reorder includes for distributed-arp-table.c, by Sven Eckelmann

 - Fix translation table change handling, by Remi Pommarel (2 patches)

 - Map VID 0 to untagged TT VLAN, by Sven Eckelmann

 - Update MAINTAINERS/mailmap e-mail addresses, by the respective authors
   (4 patches)

 - netlink: reduce duplicate code by returning interfaces,
   by Linus Lüssing

* tag 'batadv-next-pullrequest-20250117' of git://git.open-mesh.org/linux-merge:
  batman-adv: netlink: reduce duplicate code by returning interfaces
  MAINTAINERS: mailmap: add entries for Antonio Quartulli
  mailmap: add entries for Sven Eckelmann
  mailmap: add entries for Simon Wunderlich
  MAINTAINERS: update email address of Marek Linder
  batman-adv: Map VID 0 to untagged TT VLAN
  batman-adv: Don't keep redundant TT change events
  batman-adv: Remove atomic usage for tt.local_changes
  batman-adv: Reorder includes for distributed-arp-table.c
  batman-adv: Start new development cycle
====================

Link: https://patch.msgid.link/20250117123910.219278-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Simon Wunderlich says:

====================
This cleanup patchset includes the following patches:

 - bump version strings, by Simon Wunderlich

 - Reorder includes for distributed-arp-table.c, by Sven Eckelmann

 - Fix translation table change handling, by Remi Pommarel (2 patches)

 - Map VID 0 to untagged TT VLAN, by Sven Eckelmann

 - Update MAINTAINERS/mailmap e-mail addresses, by the respective authors
   (4 patches)

 - netlink: reduce duplicate code by returning interfaces,
   by Linus Lüssing

* tag 'batadv-next-pullrequest-20250117' of git://git.open-mesh.org/linux-merge:
  batman-adv: netlink: reduce duplicate code by returning interfaces
  MAINTAINERS: mailmap: add entries for Antonio Quartulli
  mailmap: add entries for Sven Eckelmann
  mailmap: add entries for Simon Wunderlich
  MAINTAINERS: update email address of Marek Linder
  batman-adv: Map VID 0 to untagged TT VLAN
  batman-adv: Don't keep redundant TT change events
  batman-adv: Remove atomic usage for tt.local_changes
  batman-adv: Reorder includes for distributed-arp-table.c
  batman-adv: Start new development cycle
====================

Link: https://patch.msgid.link/20250117123910.219278-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mptcp: sysctl: add syn_retrans_before_tcp_fallback</title>
<updated>2025-01-19T01:32:01+00:00</updated>
<author>
<name>Matthieu Baerts (NGI0)</name>
<email>matttbe@kernel.org</email>
</author>
<published>2025-01-17T17:40:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5b4fd35343d72f4d4f964de2a9fe36143cc18f39'/>
<id>5b4fd35343d72f4d4f964de2a9fe36143cc18f39</id>
<content type='text'>
The number of SYN + MPC retransmissions before falling back to TCP was
fixed to 2. This is certainly a good default value, but having a fixed
number can be a problem in some environments.

The current behaviour means that if all packets are dropped, there will
be:

- The initial SYN + MPC

- 2 retransmissions with MPC

- The next ones will be without MPTCP.

So typically ~3 seconds before falling back to TCP. In some networks
where some temporally blackholes are unfortunately frequent, or when a
client tries to initiate connections while the network is not ready yet,
this can cause new connections not to have MPTCP connections.

In such environments, it is now possible to increase the number of SYN
retransmissions with MPTCP options to make sure MPTCP is used.

Interesting values are:

- 0: the first retransmission will be done without MPTCP options: quite
     aggressive, but also a higher risk of detecting false-positive
     MPTCP blackholes.

- &gt;= 128: all SYN retransmissions will keep the MPTCP options: back to
          the &lt; 6.12 behaviour.

The default behaviour is not changed here.

Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20250117-net-next-mptcp-syn_retrans_before_tcp_fallback-v1-1-ab4b187099b0@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The number of SYN + MPC retransmissions before falling back to TCP was
fixed to 2. This is certainly a good default value, but having a fixed
number can be a problem in some environments.

The current behaviour means that if all packets are dropped, there will
be:

- The initial SYN + MPC

- 2 retransmissions with MPC

- The next ones will be without MPTCP.

So typically ~3 seconds before falling back to TCP. In some networks
where some temporally blackholes are unfortunately frequent, or when a
client tries to initiate connections while the network is not ready yet,
this can cause new connections not to have MPTCP connections.

In such environments, it is now possible to increase the number of SYN
retransmissions with MPTCP options to make sure MPTCP is used.

Interesting values are:

- 0: the first retransmission will be done without MPTCP options: quite
     aggressive, but also a higher risk of detecting false-positive
     MPTCP blackholes.

- &gt;= 128: all SYN retransmissions will keep the MPTCP options: back to
          the &lt; 6.12 behaviour.

The default behaviour is not changed here.

Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20250117-net-next-mptcp-syn_retrans_before_tcp_fallback-v1-1-ab4b187099b0@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ethtool: ts: add separate counter for unconfirmed one-step TX timestamps</title>
<updated>2025-01-18T04:01:09+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2025-01-16T10:46:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6a128cdf1926b20a94d6af7d7d03b76ba19a4f8b'/>
<id>6a128cdf1926b20a94d6af7d7d03b76ba19a4f8b</id>
<content type='text'>
For packets with two-step timestamp requests, the hardware timestamp
comes back to the driver through a confirmation mechanism of sorts,
which allows the driver to confidently bump the successful "pkts"
counter.

For one-step PTP, the NIC is supposed to autonomously insert its
hardware TX timestamp in the packet headers while simultaneously
transmitting it. There may be a confirmation that this was done
successfully, or there may not.

None of the current drivers which implement ethtool_ops :: get_ts_stats()
also support HWTSTAMP_TX_ONESTEP_SYNC or HWTSTAMP_TX_ONESTEP_SYNC, so it
is a bit unclear which model to follow. But there are NICs, such as DSA,
where there is no transmit confirmation at all. Here, it would be wrong /
misleading to increment the successful "pkts" counter, because one-step
PTP packets can be dropped on TX just like any other packets.

So introduce a special counter which signifies "yes, an attempt was made,
but we don't know whether it also exited the port or not". I expect that
for one-step PTP packets where a confirmation is available, the "pkts"
counter would be bumped.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://patch.msgid.link/20250116104628.123555-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For packets with two-step timestamp requests, the hardware timestamp
comes back to the driver through a confirmation mechanism of sorts,
which allows the driver to confidently bump the successful "pkts"
counter.

For one-step PTP, the NIC is supposed to autonomously insert its
hardware TX timestamp in the packet headers while simultaneously
transmitting it. There may be a confirmation that this was done
successfully, or there may not.

None of the current drivers which implement ethtool_ops :: get_ts_stats()
also support HWTSTAMP_TX_ONESTEP_SYNC or HWTSTAMP_TX_ONESTEP_SYNC, so it
is a bit unclear which model to follow. But there are NICs, such as DSA,
where there is no transmit confirmation at all. Here, it would be wrong /
misleading to increment the successful "pkts" counter, because one-step
PTP packets can be dropped on TX just like any other packets.

So introduce a special counter which signifies "yes, an attempt was made,
but we don't know whether it also exited the port or not". I expect that
for one-step PTP packets where a confirmation is available, the "pkts"
counter would be bumped.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://patch.msgid.link/20250116104628.123555-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
