Commit Graph

1449162 Commits

Author SHA1 Message Date
Eric Dumazet
46762cefe7 net: serialize netif_running() check in enqueue_to_backlog()
Syzbot reported a KASAN slab-use-after-free in fib_rules_lookup().

The root cause is a race condition where packets can escape the backlog
flushing during device unregistration (e.g., during netns exit).

Commit e9e4dd3267 ("net: do not process device backlog during unregistration")
introduced a lockless netif_running() check in enqueue_to_backlog() to
prevent queuing packets to an unregistering device.

However, this creates a TOCTOU race window.

A lockless transmitter (like veth_xmit) can pass
the check before dev_close() clears IFF_UP. If the transmitter is then
delayed, flush_all_backlogs() can run and finish before the transmitter
grabs the backlog lock and queues the packet. The packet then escapes
the flush and triggers UAF later when processed.

Fix this by moving the netif_running() check inside the backlog lock.
This serializes the check with the flush work (which also grabs the lock).
We then either queue the packet before the flush runs (so it gets flushed),
or check netif_running() after the flush/close completes (so it gets dropped).

Fixes: e9e4dd3267 ("net: do not process device backlog during unregistration")
Reported-by: syzbot+965506b59a2de0b6905c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a315824.b0403584.28d0ff.0000.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260616141317.407791-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 15:42:53 -07:00
Jakub Kicinski
d755d45bc0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes in preparation for the net-next PR.

Conflicts:

net/tls/tls_sw.c
  406e8a651a ("net: skmsg: preserve sg.copy across SG transforms")
  79511603a6 ("tls: remove dead sockmap (psock) handling from the SW path")

drivers/net/ethernet/microsoft/mana/mana_en.c
  f8fd56977e ("net: mana: guard TX wq object destroy with INVALID_MANA_HANDLE check")
  d07efe5a6e ("net: mana: Use per-queue allocation for tx_qp to reduce allocation size")
https://lore.kernel.org/ajAPXu-C_PuTgV-a@sirena.org.uk

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:59:58 -07:00
Yiming Qian
406e8a651a net: skmsg: preserve sg.copy across SG transforms
The sk_msg sg.copy bitmap is part of the scatterlist entry ownership
state. A set bit tells sk_msg_compute_data_pointers() not to expose the
entry through writable BPF ctx->data. This protects entries backed by
pages that are not private to the sk_msg, such as splice-backed file
page-cache pages.

Several sk_msg transform paths move, copy, split, or compact
msg->sg.data[] entries without moving the matching sg.copy bit. This can
make an externally backed entry arrive at a new slot with a clear copy
bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable
ctx->data and BPF stores can modify the original page cache.

Keep sg.copy synchronized with sg.data[] whenever entries are
transferred, shifted, split, or copied into a new sk_msg. Clear the bit
when an entry is replaced by a newly allocated private page or freed.
This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(),
sk_msg_xfer(), and tls_split_open_record(), including the partial tail
entry created during TLS open-record splitting.

Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Cc: stable@vger.kernel.org
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Yiming Qian <yimingqian591@gmail.com>
Link: https://patch.msgid.link/20260610062137.49075-1-yimingqian591@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:38:46 -07:00
Jakub Kicinski
8940a8202c Merge branch 'appletalk-move-the-protocol-out-of-tree'
Jakub Kicinski says:

====================
appletalk: move the protocol out of tree

This tiny series moves appletalk out of tree, to:

  https://github.com/linux-netdev/mod-orphan

Core maintainainers are unable to keep up with the rate of security
bug reports and fixes. Nobody seems to care about appletalk enough
to review the patches.

As Eric pointed out Mac OS dropped AppleTalk over a decade ago.
====================

Link: https://patch.msgid.link/20260615222935.947233-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:37:17 -07:00
Jakub Kicinski
8a398a0c18 appletalk: move the protocol out of tree
AppleTalk has been removed in MacOS X 10.6 (Snow Leopard), in 2009,
according to Wikipedia. We recently got a burst of AI generated
fixes to this protocol which nobody is reviewing.

Let AppleTalk follow AX.25 and hamradio out of the Linux tree.
We we will maintain the code at: github.com/linux-netdev/mod-orphan
for anyone interested in playing with it.

Retain the uAPI for now. No strong reason, simply because I suspect
keeping it will be less controversial.

Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20260615222935.947233-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:37:06 -07:00
Jakub Kicinski
023f9b0f2f appletalk: stop storing per-interface state in struct net_device
AppleTalk keeps its per-interface control block (struct atalk_iface)
directly in struct netdevice (dev->atalk_ptr). This is the only thing
tying the protocol into the core net_device layout and is the sole
blocker to moving AppleTalk out of tree.

Replace dev->atalk_ptr with a small ifindex-keyed hashtable internal
to ddp.c. The existing atalk_interfaces list stays the owner of the iface
objects; the hashtable is purely a fast dev->iface index and reuses
the same atalk_interfaces_lock.

AFAICT this patch does not make this code any more racy than it already
is, I'm sure Sashiko will point out some basically existing bugs.
AFAICT atalk_interfaces_lock is the innermost lock already.

Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20260615222935.947233-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:37:06 -07:00
Jakub Kicinski
ffaf896773 Merge branch 'tls-reject-the-combination-of-tls-and-sockmap'
Jakub Kicinski says:

====================
tls: reject the combination of TLS and sockmap

There are no known TLS+sockmap users and it has some known
hard to solve bugs. Let's reject this configuration as we
discussed a number of times.
====================

Link: https://patch.msgid.link/20260614014102.461064-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:48 -07:00
Jakub Kicinski
5949a7cf11 selftests/bpf: test that TLS crypto is rejected on a sockmap socket
TLS and sockmap are mutually exclusive. We already have a test
for the sockmap side rejecting kTLS, add the inverse test matching
patch 1 of this series.

Link: https://patch.msgid.link/20260614014102.461064-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:41 -07:00
Jakub Kicinski
6af8971d91 selftests/bpf: drop the unused kTLS program from test_sockmap
With the sockmap + kTLS tests gone, the BPF-side support in test_sockmap
is dead: the tls_sock_map map and bpf_prog3 (which redirected skbs into
it) are no longer referenced. Remove them, along with the now-unused
bpf_write_pass() helper.

bpf_prog3 was progs[2], so renumber the progs[] users in test_sockmap.c:
the sockops program drops to progs[2] and the sk_msg tx programs to
progs[3..7]. Shrink the map/prog arrays from 9 to 8 and drop the
tls_sock_map entry (the last one) from map_names[] to match.

Link: https://patch.msgid.link/20260614014102.461064-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:41 -07:00
Jakub Kicinski
faf89584e4 selftests/bpf: remove sockmap + ktls tests
The combination of sockmap and TLS is no longer supported - installing
the TLS ULP on a sockmap socket (and vice versa) is now rejected. Remove
the tests that exercise the combination along with their BPF program;
the file covered nothing but sockmap sockets holding kTLS contexts.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://patch.msgid.link/20260614014102.461064-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:41 -07:00
Jakub Kicinski
79511603a6 tls: remove dead sockmap (psock) handling from the SW path
TLS and sockmap are now mutually exclusive. Try to delete the code
from sendmsg and recvmsg path which is now obviously dead.

The main goal is to delete enough code for AI security scanners
to no longer bother us with sockmap related bugs. At the same
time retain the code in case someone has the cycles to fix
all of this and make the integration work, again.

If the integration does not get restored we can wipe the rest
of the skmsg code from TLS in two or three releases.

The changes on the Tx side are deeper since that's where most
of the bugs are, Rx side simply takes the data from sockmap
and gives it to the user. On Tx split record handling and
rolling back the iterator were the two problem areas.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20260614014102.461064-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:41 -07:00
Jakub Kicinski
460e648661 tls: reject the combination of TLS and sockmap
TLS and sockmap (BPF psock) integration hides a lot of latent bugs.
Bugs which may be more or less relevant for real users but they
are definitely exploitable.

We could not find anyone actively using this integration so let's
reject this config. Adding a TLS socket to a sockmap was already
rejected by sk_psock_init() through the inet_csk_has_ulp() check.
We need to reject the attempts to configure the TLS keys (rather
than adding the ULP itself) because checking prior to the ULP
installation is tricky without risking a race with sockmap getting
added in parallel (sockmap does not hold the socket lock).

This patch is a minimal rejection of the feature. Subsequent patch
in the series will do a light dead code removal. Full cleanup would
require a major rewrite of the Tx path, we don't need skmsg any more.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20260614014102.461064-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:55:40 -07:00
Jakub Kicinski
e1f544466b Merge branch 'atm-remove-more-dead-code'
Jakub Kicinski says:

====================
atm: remove more dead code

Commit 6deb535950 ("net: remove unused ATM protocols and legacy
ATM device drivers") removed a good chunk of old ATM drivers.
Our goal going forward is to limit the ATM support to PPPoATM
used in ADSL deployments.

A recent burst of AI generated fixes for net/atm/signaling.c and
net/atm/svc.c made me look closer at the remaining code. PPPoATM runs
over permanent virtual circuits (PF_ATMPVC) with a statically
configured VPI/VCI. We can drop switched virtual circuits (SVCs)
and user-space signaling (atmsigd) support. While digging around
I noticed a few more obviously dead pieces of code.

Annoyingly, I have applied one "fix" to QoS config which will
now make net conflict with this series :/
====================

Link: https://patch.msgid.link/20260615194416.752559-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:57 -07:00
Jakub Kicinski
8f9616500c atm: remove orphaned uAPI for deleted drivers, protocols and SVCs
ATM removals have left a number of uAPI headers and ioctl
definitions with no in-kernel implementation behind them:

 - device headers for adapters deleted with the legacy PCI/SBUS drivers:
   atm_eni.h, atm_he.h, atm_idt77105.h, atm_nicstar.h, atm_zatm.h and
   the atmtcp pair atm_tcp.h / <linux/atm_tcp.h>
 - protocol headers for the removed CLIP, LANE and MPOA stacks:
   atmarp.h, atmclip.h, atmlec.h, atmmpc.h
 - atmsvc.h and the SVC / p2mp / local-address ioctls in atmdev.h
   (ATM_{GET,RST,ADD,DEL}ADDR, ATM_{ADD,DEL,GET}LECSADDR,
   ATM_{ADD,DROP}PARTY) left behind by the SVC and address-registry
   removals

None of these are referenced by any remaining in-tree code.
Let's try to delete all this. Chances are nobody cares about
these headers any more. I'm keeping this separate from the
kernel side code changes for ease of revert, in case I am
proven wrong...

Link: https://patch.msgid.link/20260615194416.752559-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:53 -07:00
Jakub Kicinski
e44e224e2f atm: remove unused ATM PHY operations
The PHY operations are vestiges of the SAR/framer split used by the
removed PCI/SBUS ATM adapters:

 - atmdev_ops::phy_put / ::phy_get (register accessors) are never called
   by the core and solos-pci only listed them as NULL
 - struct atmphy_ops and atm_dev::phy have no users at all - nothing
   assigns or dereferences them

Remove all of them. atm_dev::phy_data is kept: solos-pci repurposes it
to stash its per-port channel index.

Link: https://patch.msgid.link/20260615194416.752559-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:53 -07:00
Jakub Kicinski
ae6e653514 atm: remove the unused pre_send and send_bh device operations
atmdev_ops::pre_send (a TX pre-processing hook) and ::send_bh (a
bottom-half capable send variant) have no implementation behind them:
no remaining ATM driver sets either, so vcc_sendmsg() always skipped
pre_send and the raw AAL0/AAL5 paths always fell back to ->send().
The drivers that used these hooks were removed with the legacy ATM
adapters.

Drop both operations and the dead branches that tested for them.

Link: https://patch.msgid.link/20260615194416.752559-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
6719d57ee0 atm: remove the unused change_qos device operation
atmdev_ops::change_qos() was the hook for renegotiating the traffic
parameters of an already-connected VCC, driven from SO_ATMQOS on a
connected socket (and previously from the SVC as_modify path, now gone).
None of the ATM drivers left in tree implement it - solos-pci only listed
change_qos = NULL - so atm_change_qos() always returned -EOPNOTSUPP.

Drop the operation and return -EOPNOTSUPP directly.

Link: https://patch.msgid.link/20260615194416.752559-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
aa582dc25a atm: remove SVC socket support and the signaling daemon interface
ATM switched virtual circuits (SVCs) are set up and torn down by a
user-space signaling daemon (atmsigd) which the kernel talks to over
a dedicated "sigd" socket: the kernel marshals Q.2931-style requests
(as_connect, as_listen, as_accept, as_close, ...) to the daemon and
applies the results to PF_ATMSVC sockets. This is the machinery behind
classical SVC use and was the foundation for LANE / MPOA, all of which
have been removed.

DSL deployments do not use any of this. PPPoATM and BR2684 run over
permanent virtual circuits (PF_ATMPVC) with a statically configured
VPI/VCI; no atmsigd, no Q.2931. Neither remaining ATM driver
(solos-pci, the USB DSL modems) is reachable through the SVC path.

Remove the SVC socket family and the signaling interface:

 - delete net/atm/svc.c, net/atm/signaling.c and signaling.h
 - drop atmsvc_init()/atmsvc_exit() and the PF_ATMSVC registration and
   module alias
 - drop the ATMSIGD_CTRL ioctl (sigd_attach) and the /proc/net/atm/svc
   file
 - fold the SVC branch out of atm_change_qos(); all sockets are PVCs now

The obsolete ATM_SETSC ioctl stub is left in place (it already just
warns and returns 0), as is the struct atm_vcc SVC bookkeeping shared
with the queueing layer.

Link: https://patch.msgid.link/20260615194416.752559-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
a5a12d76d2 atm: remove the local ATM (NSAP) address registry
net/atm/addr.c maintained the per-device lists of local NSAP addresses
(dev->local) and ILMI-learned LECS addresses (dev->lecs). These exist
solely to serve SVC signaling: the lists are populated through the
ATM_{ADD,DEL,RST}ADDR / ATM_{ADD,DEL,GET}LECSADDR ioctls used by the
atmsigd / ILMI daemons, and consumed when registering addresses with the
signaling daemon. The LECS list belonged to LAN Emulation, which has
been removed.

With no SVC users in a DSL-only configuration these lists are always
empty, so drop the registry entirely:

 - remove the ADDR/LECSADDR/RSTADDR ioctls
 - drop the now-always-empty "atmaddress" sysfs attribute
 - remove the dev->local / dev->lecs lists, structs and enums
 - delete net/atm/addr.c and net/atm/addr.h

The device ESI ("MAC" address) and its ATM_{G,S}ETESI ioctls and
"address" sysfs attribute are retained - the USB DSL modems populate
the ESI.

Link: https://patch.msgid.link/20260615194416.752559-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
277fb497d1 atm: remove dead SONET PHY ioctls
The SONET_* ioctls are SONET/SDH PHY controls that atm_dev_ioctl() and
the compat path only ever forwarded to the driver's ->ioctl() handler.
The PHY drivers that implemented them (the S/UNI library and the framers
on the removed PCI/SBUS adapters) are gone, and neither surviving driver
services them: solos-pci has no ->ioctl, and usbatm handles only
ATM_QUERYLOOP. They now uniformly return an error regardless.

Drop the SONET compat passthrough and the SONET cases in atm_dev_ioctl(),
along with the now-unused linux/sonet.h includes. The SONET_* uAPI
definitions are untouched.

Link: https://patch.msgid.link/20260615194416.752559-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
b20aa9eded atm: remove the unused send_oam / push_oam callbacks
The atmdev_ops::send_oam device operation and the atm_vcc::push_oam
callback were the kernel's interface for raw F4/F5 OAM cell exchange.
Nothing assigns them a non-NULL value and nothing ever invokes them:
the core only ever initialises push_oam to NULL (in vcc_create() and the
AAL init helpers) and the Solos driver only lists send_oam = NULL for
documentation. The drivers that actually drove OAM through these hooks
were removed along with the legacy ATM adapters.

Drop both callbacks and the NULL initialisers.

Link: https://patch.msgid.link/20260615194416.752559-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:52 -07:00
Jakub Kicinski
c1468145ce atm: remove AAL3/4 transport support
AAL3/4 is an obsolete connection-oriented ATM adaptation layer that has
seen no real use since the SMDS-era hardware it was designed for (90s?).
We are only maintaining ATM support in-tree to keep PPPoATM running,
and PPPoATM runs over AAL5.

Drop the "raw" AAL3/4 transport (atm_init_aal34()) and the ATM_AAL34
cases in the connect and traffic-parameter paths. A vcc_connect() with
qos.aal == ATM_AAL34 now fails with -EPROTOTYPE.

uAPI cleanup is performed later, separately.

Link: https://patch.msgid.link/20260615194416.752559-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 08:53:51 -07:00
David Yang
72dfa4700f net: dsa: sja1105: fix lastused timestamp in flower stats
flow_stats_update() takes an absolute timestamp for lastused, not delta.
Fix that.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260614141320.1133321-1-mmyangfl@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 19:01:48 -07:00
Jakub Kicinski
2c53418347 Merge branch 'extend-netkit-io_uring-zc-selftests'
Daniel Borkmann says:

====================
Extend netkit io_uring ZC selftests

Small follow-up to the HW net selftests, in particular to add a
selftest showing that also large rx_buf_len for io_uring ZC is
supported with netkit queue leasing.
====================

Link: https://patch.msgid.link/20260614102607.863838-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:58:03 -07:00
Daniel Borkmann
74ac711839 selftests/net: Add hugepage kernel config dependency for zcrx
test_iou_zcrx_large_buf in drivers/net/hw/nk_qlease.py runs iou-zcrx
with rx_buf_len > page size, backed by a hugepage-mapped area. Thus
add to the Kconfig.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260614102607.863838-5-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:58:01 -07:00
Daniel Borkmann
5024cfc8a3 selftests/net: Add netkit io_uring ZC test for large rx_buf_len
Add test_iou_zcrx_large_buf, which runs iou-zcrx with rx_buf_len >
page size (-x 2) through a netkit-leased RX queue. The netkit ifindex
is opaque to io_uring, but rx_page_size is honoured by the leased
physical qops via netif_mp_open_rxq()'s lease redirect.

Originally, I also added a BIG TCP variant on top, but dropped it
here as fbnic (and the QEMU fbnic model) has no BIG TCP support
to exercise it as this point.

Tested against the QEMU fbnic emulation. The new test exercises
the > page rx_buf_len path only when the leased NIC advertises
QCFG_RX_PAGE_SIZE; otherwise it skips.

For fbnic, I used Bjorn's patches locally [0]:

  # ./nk_qlease.py
  TAP version 13
  1..5
  ok 1 nk_qlease.test_iou_zcrx
  ok 2 nk_qlease.test_iou_zcrx_large_buf
  ok 3 nk_qlease.test_attrs
  ok 4 nk_qlease.test_attach_xdp_with_mp
  ok 5 nk_qlease.test_destroy
  # Totals: pass:5 fail:0 xfail:0 xpass:0 skip:0 error:0

Without those patches (aka not advertising QCFG_RX_PAGE_SIZE):

  # ./nk_qlease.py
  TAP version 13
  1..5
  ok 1 nk_qlease.test_iou_zcrx
  ok 2 nk_qlease.test_iou_zcrx_large_buf # SKIP Large chunks are not supported -95
  ok 3 nk_qlease.test_attrs
  ok 4 nk_qlease.test_attach_xdp_with_mp
  ok 5 nk_qlease.test_destroy
  # Totals: pass:4 fail:0 xfail:0 xpass:0 skip:1 error:0

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://lore.kernel.org/netdev/20260522113225.241337-1-bjorn@kernel.org/ [0]
Link: https://patch.msgid.link/20260614102607.863838-4-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:58:01 -07:00
Daniel Borkmann
96fda937b4 selftests/net: Use public NetDrvContEnv API in nk_qlease fixtures
Expose the netkit host ifname as a public attribute nk_host_ifname
(symmetric with the already-public nk_guest_ifname), rename _attach_bpf
to a public attach_bpf, and add a public detach_bpf helper that
encapsulates the tc-filter teardown bookkeeping. Switch the fixtures
to this public API. No functional change and keeps pylint happy.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260614102607.863838-3-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:58:01 -07:00
Daniel Borkmann
bc5c25c8f6 selftests/net: Move netkit lease hw setup into per-test fixtures
The HW counterpart of nk_qlease.py was carrying its lease setup in main()
and stashing src_queue / nk_queue / nk_*_ifname on cfg, which had drawbacks
called out during the review at [0].

This is the deferred half of the cleanup that landed in commit e254ffb950
("selftests/net: Split netdevsim tests from HW tests in nk_qlease") which
was the SW counterpart of nk_qlease.py.

While at it, convert the open-coded "ip netns exec" prefixes in the test
bodies over to the ns= argument of cmd() / bkg().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://lore.kernel.org/netdev/20260408162238.16709090@kernel.org/ [0]
Link: https://patch.msgid.link/20260614102607.863838-2-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:58:00 -07:00
Jakub Kicinski
987257c49b Merge branch 'ionic-expose-more-port-stats-to-ethtool'
Eric Joyner says:

====================
ionic: Expose more port stats to ethtool [part]

The primary aim of this patchset is to support the reporting of new port
statistics (and one old one) that firmware sends to the driver. A scheme
for these extra stats is introduced in order to prevent devices that
don't support these new statistics from unconditionally setting them or
reporting them in ethtool.
====================

Link: https://patch.msgid.link/20260614205303.48088-1-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:15:12 -07:00
Eric Joyner
3277e605ac ionic: Get "link_down_count" ext link stat from firmware
The number of times that link has gone down at the port level is tracked
by the firmware and sent to the driver via regular DMA writes to an
instance of struct ionic_port_status in the driver's memory.

This statistic was never reported in favor of a driver-derived stat, but
doing it in the driver was never necessary since firmware had been
reporting it the whole time. Since it would be more accurate and true to
the description of the statistic to get this count at the PHY level,
replace the driver-calculated statistic with one derived from the
firmware one and remove the driver-calculated one entirely.

The stat reported by the ethtool .get_link_ext_stats() handler is
normalized to 0 on driver load and any device resets that require the
driver to rebuild state while also handling overflows.

Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Link: https://patch.msgid.link/20260614205303.48088-5-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:15:08 -07:00
Eric Joyner
cb683ff6ee ionic: Report "rx_bits_phy" stat to ethtool
This stat contains the number of total bits that the PHY has received;
it's useful for BER calculations. Add it to the ethtool stats output.

However, since this is one of the new "extra port stats", it's reported
in a different manner than the existing port stats and only
conditionally added to the ethtool stats output list: both the
DEV_CAP_EXTRA_STATS capability must be supported by the firmware, and
the firmware must set the value of the statistic to something other than
IONIC_STAT_INVALID.

To help support this scheme, the extra port stats region is initialized to
0xff's/IONIC_STAT_INVALID by the driver, to ensure the statistics that
the driver knows about but the firmware does not are still invalid
to the driver.

Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Link: https://patch.msgid.link/20260614205303.48088-4-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:15:08 -07:00
Eric Joyner
433bc50081 ionic: Update ionic_if.h with new extra port stats
Add a new structure to report additional statistics from the firmware to
struct ionic_port_info. This new struct currently only contains FEC
related statistics, but any new port-level statistics collected by the
firmware would go into it.

The new structure is located in the same area as the unused
ionic_port_pb_stats structure, so this patch also removes that and its
supporting enumerations since they was never used in this driver.

Finally, to indicate firmware support for the new structure, introduce a
new device capability that the driver can use to see if the attached
device supports reporting these extra stats.

Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Link: https://patch.msgid.link/20260614205303.48088-3-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:15:08 -07:00
Brett Creeley
7678e69079 ionic: Fix check in ionic_get_link_ext_stats
The current check will fail if SR-IOV is not initialized for the
physical function; this is because is_physfn is 0 if sriov_init() isn't
run or fails. Change the check that prevents getting the link down count
to use is_virtfn instead so that VFs don't get this functionality, which
was the original intent.

Fixes: 132b4ebfa0 ("ionic: add support for ethtool extended stat link_down_count")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Link: https://patch.msgid.link/20260614205303.48088-2-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 18:15:08 -07:00
Jakub Kicinski
1959005463 Merge branch 'net-dsa-mxl862xx-serdes-ports'
Daniel Golle says:

====================
net: dsa: mxl862xx: SerDes ports

Add support for the two SerDes PCS interfaces of the MxL862xx switch
ICs, which can both either be used to connect PHYs or SFP cages, or as
CPU port(s). 1000Base-X, 2500Base-X, 10GBase-R, 10GBase-KR, SGMII,
QSGMII and USXGMII (single 10G or quad 2.5G) are supported.

The firmware only added the API to directly control the PCS as of
version 1.0.84, so the PCS features are gated behind a version check.

As the driver is growing do some refactoring to break out the phylink
parts into mxl862xx-phylink.h.
====================

Link: https://patch.msgid.link/cover.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:03 -07:00
Daniel Golle
13ea4d4888 net: dsa: mxl862xx: add support for SerDes ports
The MxL862xx has two XPCS/SerDes interfaces (XPCS0 for ports 9-12,
XPCS1 for ports 13-16). Each can operate in various single-lane modes
(SGMII, 1000Base-X, 2500Base-X, 10GBase-R, 10GBase-KR, USXGMII) or as
QSGMII or 10G_QXGMII providing four sub-ports per interface.

Implement phylink PCS operations using the firmware's XPCS API:

  - pcs_enable/pcs_disable: refcount the sub-ports sharing an XPCS
    and power it down once the last sub-port is released.
  - pcs_config: configure negotiation mode and CL37/SGMII advertising.
  - pcs_get_state: read link state and the link-partner ability word
    from firmware and decode using phylink's standard CL37, SGMII, and
    USXGMII decoders.
  - pcs_an_restart: restart CL37 or CL73 auto-negotiation.
  - pcs_link_up: force speed/duplex for SGMII.
  - pcs_inband_caps: report per-mode in-band status capabilities.

Register a PCS instance for each SerDes interface and
QSGMII/10G_QXGMII sub-ports during setup. Advertise the supported
interface modes in phylink_get_caps based on port number.

Firmware older than 1.0.84 lacks the XPCS API and instead configures
the SerDes itself, using defaults stored in flash. mac_select_pcs()
returns NULL in that case while the single-lane interface modes stay
advertised, so a CPU port keeps working in the firmware-configured
mode.

Lacking support for expressing PHY-side role modes in Linux only the
MAC-side of SGMII, QSGMII, USXGMII and 10G_QXGMII are implemented for
now.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/736e4df02e4cb8c530c1670cbe7efac20b5d696d.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:01 -07:00
Daniel Golle
7dab839724 net: dsa: mxl862xx: move API macros to mxl862xx-host.h
Move the MXL862XX_API_WRITE, MXL862XX_API_READ and
MXL862XX_API_READ_QUIET convenience macros from mxl862xx.c to
mxl862xx-host.h next to the mxl862xx_api_wrap() prototype they wrap.
This makes them available to other compilation units that include
mxl862xx-host.h, which is needed once the SerDes PCS code in
mxl862xx-phylink.c also calls firmware commands.

No functional change.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/914f57931e79cc3932a9f32813465c08d29cf4bf.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:01 -07:00
Daniel Golle
c103433200 net: dsa: mxl862xx: move phylink stubs to mxl862xx-phylink.c
Move the phylink MAC operations and get_caps callback from mxl862xx.c
into a dedicated mxl862xx-phylink.c file. This prepares for the SerDes
PCS implementation which adds substantial phylink/PCS code -- keeping
it in a separate file avoids function-position churn in the main
driver file.

No functional change.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/fb9336de94bef47a0834287cbca87954e5e4c795.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:00 -07:00
Daniel Golle
937137db79 net: dsa: mxl862xx: store firmware version for feature gating
Query the firmware version at init (already done in wait_ready),
cache it in priv->fw_version, and provide MXL862XX_FW_VER_MIN()
for version-gated code paths throughout the driver.

MXL862XX_FW_VER() packs major/minor/revision into a u32 with
bitwise shifts so that versions compare with natural ordering,
independent of host endianness.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/91a26a8ffeaa2ce1729f98347e93e779973976bb.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:00 -07:00
Lorenzo Bianconi
a459b560e5 net: airoha: use int instead of atomic_t for qdma users counter
QDMA users counter is always accessed holding RTNL lock so we do not
require atomic_t for it.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:35:41 -07:00
Jakub Kicinski
fbc6a80cb5 Merge branch 'mac-phy-interrupt-changed-to-level-triggered-interrupt'
Selvamani Rajagopal says:

====================
MAC-PHY interrupt changed to level triggered interrupt

According to OPEN Alliance 10BASE-T1x MAC-PHY Serial Interface
specification, MAC-PHY interrupt is "active low, level triggered".
The specification mentions about the conditions in which the IRQ
is asserted and deasserted.

Bug is inadvertently introduced by treating the IRQ in the OA TC6
framework driver and in dt-binding YAML file as edge triggered.

With the changes to use level triggered interrupt, use of threaded
irq is more efficient than the current method that has interrupt hander
working with work queue.

This change of interrupt handler mechanism exposed couple of race
conditions due to the fact that interrupts were not masked on protocol
error. And pointers were not initialized with null after skbs are freed.

Changes are done in two files
 - OA TC6 framework Ethernet driver
 - YAML file for the vendor that already uses OA TC6 framework.

Maintainer for this driver is already informed and aware of these
changes. Testing for these changes was done in onsemi's setup and
found to be working.
====================

Link: https://patch.msgid.link/20260611-level-trigger-v5-0-4533a9e85ce2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:32:14 -07:00
Selvamani Rajagopal
31e56112e6 dt-bindings: net: updated interrupt type to be active low, level triggered
According to OPEN Alliance 10BASE-T1x MACPHY Serial Interface (TC6)
specification, interrupt type is active low, level triggered interrupt.

Specification calls for when interrupt level will be asserted and what
condition it is de-asserted. By using edge triggered interrupt, there is a
potential chance to miss it, particularly if it is asserted when interrupt
is disabled.

Level triggered interrupt can't be missed as it gets de-asserted only on
interrupt handler taking actions on interrupting conditions.

Fixes: ac49b950be ("dt-bindings: net: add Microchip's LAN865X 10BASE-T1S MACPHY")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260611-level-trigger-v5-4-4533a9e85ce2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:32:10 -07:00
Selvamani Rajagopal
a5a1d11dd3 net: ethernet: oa_tc6: Remove FCS size in RX frame
OA TC6 MAC-PHY appends FCS to the incoming frame. It must be
removed from the frame before being passed to the stack.

With FCS in the frame, many applications, like ping or any
application that uses IP layer may work as they may
carry the packet size information in the protocol.

Application like ptp4l, particularly if it uses layer 2
for its communication, it will fail with "bad message" due to
the extra 4 bytes added by the presence of FCS.

Fixes: d70a0d8f2f ("net: ethernet: oa_tc6: implement receive path to receive rx ethernet frames")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260611-level-trigger-v5-3-4533a9e85ce2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:32:10 -07:00
Selvamani Rajagopal
a221d3f7e3 net: ethernet: oa_tc6: mdiobus->parent initialized with NULL
As "dev" pointer in oa_tc6 structure is never initialized,
mbiobus->parent was initialized with NULL.  This change
fixes it by initializing it with device pointer of spi.

Fixes: 8f9bf857e4 ("net: ethernet: oa_tc6: implement internal PHY initialization")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260611-level-trigger-v5-2-4533a9e85ce2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:32:09 -07:00
Selvamani Rajagopal
b542d13fab net: ethernet: oa_tc6: Interrupt is active low, level triggered.
According OPEN Alliance 10BASET1x MAC-PHY Serial Interface
specification, interrupt is active low, level triggered.

Code used edge triggered interrupt which has the risk of losing an
interrupt on instances like when interrupt is disabled. Level
triggered interrupt won't be deasserted unless handler runs and
clear the interrupting conditions.

Interrupt handler mechanism is changed to threaded irq from
interrupt handler and kernel thread waiting on work queue.
Threaded irq mechanism is best suited for level triggered interrupt
as it disables the interrupt until handler is run in thread level,
while giving us an ability to have interrupt context handler to
signal the threaded irq handler.

Introduced a logic to disable the device interrupt on error. Error
could be due in data chunk's header and footer or SPI interface itself.
This will avoid having repeated interrupts, in case the driver couldn't
recover from the error condition with the available recovery mechanism.

Fixes: 2c6ce53544 ("net: ethernet: oa_tc6: implement mac-phy interrupt")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Link: https://patch.msgid.link/20260611-level-trigger-v5-1-4533a9e85ce2@onsemi.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:32:09 -07:00
Jakub Kicinski
c02fca0bef Merge branch 'icssg-xdp-zero-copy-bug-fixes'
Meghana Malladi says:

====================
ICSSG XDP zero copy bug fixes [part]

This patch series fixes bugs introduced while adding xdp
zero copy support in the icssg driver.

Patch 1: Fix wakeup handling for Rx when available CPPI
descriptor is zero
Patch 2,3: Fix destination tag in CPPI descriptor to enable
proper Tx xmit for HSR offload mode with XDP and zero copy
====================

Link: https://patch.msgid.link/20260611185744.2498070-1-m-malladi@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:22:24 -07:00
Meghana Malladi
f969128841 net: ti: icssg: Use undirected TX tag for XDP zero copy in HSR offload mode
emac_xsk_xmit_zc() has the same issue as the fixed emac_xmit_xdp_frame():
it always sets the CPPI5 descriptor destination tag to emac->port_id,
which directs the PRU firmware to transmit on only one slave port in HSR
mode, breaking redundancy.

Apply the same fix: in HSR offload mode when NETIF_F_HW_HSR_DUP is set,
use PRUETH_UNDIRECTED_PKT_DST_TAG (port 0) so the PRU duplicates frames
to both ports. Also set PRUETH_UNDIRECTED_PKT_TAG_INS when
NETIF_F_HW_HSR_TAG_INS is set so the PRU re-inserts the HSR sequence tag
that was stripped by the PRU on RX before the XDP program saw the frame.

This ensures XSK XDP_TX frames in HSR mode are treated identically to
skb TX via hsr0.

Fixes: 8756ef2eb0 ("net: ti: icssg-prueth: Add AF_XDP zero copy for TX")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Link: https://patch.msgid.link/20260611185744.2498070-4-m-malladi@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:22:16 -07:00
Meghana Malladi
bcbf73d981 net: ti: icssg: Use undirected TX tag for native XDP in HSR offload mode
emac_xmit_xdp_frame() always sets the CPPI5 descriptor destination
tag to emac->port_id, which directs the PRU firmware to transmit
the frame on that specific slave port only.  In HSR offload mode
this bypasses the firmware's HSR duplication logic: the frame goes
out on one ring leg and never appears on the other, breaking HSR
redundancy for XDP_TX paths.

icssg_ndo_start_xmit() already handles this correctly: when HSR
offload mode is active and NETIF_F_HW_HSR_DUP is set it substitutes
PRUETH_UNDIRECTED_PKT_DST_TAG (port 0) so the PRU duplicates the
frame to both slave ports.  It also sets PRUETH_UNDIRECTED_PKT_TAG_INS
in epib[1] when NETIF_F_HW_HSR_TAG_INS is set so the PRU inserts the
HSR sequence tag, which XDP_TX frames lack (the tag is stripped by
the PRU on RX before the frame reaches the XDP program).

Apply the same logic in emac_xmit_xdp_frame() so XDP_TX frames in
HSR mode are treated identically to skb TX via hsr0.

Fixes: 62aa3246f4 ("net: ti: icssg-prueth: Add XDP support")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Link: https://patch.msgid.link/20260611185744.2498070-3-m-malladi@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:22:16 -07:00
Meghana Malladi
dfb787f7d1 net: ti: icssg-prueth: Fix AF_XDP fill ring alloc and wakeup condition
emac_rx_packet_zc() calls prueth_rx_alloc_zc() with count (frames
received in the current NAPI poll) as the allocation budget.  Two
problems arise from this:

1. When the CPPI5 descriptor pool is exhausted (avail_desc == 0,
   FDQ already holds the maximum number of descriptors), count > 0
   still triggers allocation attempts that all fail, spamming the
   kernel log with "rx push: failed to allocate descriptor" at
   high packet rates.

2. The XSK wakeup condition "ret < count" is wrong when avail_desc
   is zero: ret == 0 and count can be up to 64, so the condition is
   always true.  This causes ~200 spurious ndo_xsk_wakeup() calls
   per second even when the FDQ is already full, wasting CPU cycles
   in repeated NAPI invocations that process zero frames.

Fix both by introducing alloc_budget = min(budget, avail_desc):
- When avail_desc == 0 no allocation is attempted, avoiding pool
  exhaustion errors.  The wakeup condition "ret < alloc_budget"
  evaluates to 0 < 0 == false, correctly clearing the wakeup flag
  so the hardware IRQ re-arms NAPI without spurious kicks.
- In steady state avail_desc == count <= budget, so alloc_budget
  == count and behaviour is unchanged.
- After a dry-ring stall (count == 0, avail_desc > 0), alloc_budget
  > 0 causes new descriptors to be posted to the FDQ so the hardware
  can resume receiving immediately.

Fixes: 7a64bb388d ("net: ti: icssg-prueth: Add AF_XDP zero copy for RX")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Link: https://patch.msgid.link/20260611185744.2498070-2-m-malladi@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:22:16 -07:00
Jakub Kicinski
7f80f60161 Merge branch 'tcp-rehash-onto-different-local-ecmp-path-on-retransmit-timeout'
Neil Spring says:

====================
tcp: rehash onto different local ECMP path on retransmit timeout

Currently sk_rethink_txhash() re-rolls the socket's txhash on RTO,
PLB, and spurious-retransmission events, but the new hash is not
propagated into the IPv6 ECMP path selection.  The cached
route is reused and fib6_select_path() is never re-invoked, so
the connection uses the same local ECMP decision.

This series adds the two missing pieces:

1. __sk_dst_reset() alongside sk_rethink_txhash() so the cached dst
   is invalidated and the next transmit triggers a fresh route lookup.

2. fl6->mp_hash set from sk_txhash before each route lookup so
   fib6_select_path() picks a path from the (potentially re-rolled) hash.

The override applies only to fib_multipath_hash_policy 0 (the default L3
policy).  Its hash includes the flow label, but that is 0 by default
(np->flow_label is unset; auto_flowlabels computes the on-wire label
later, per packet), so flows to the same peer share one local path.
Keying it on sk_txhash makes that local path per-connection and lets a
rehash re-select it; even when a flow label is present (reflected REPFLOW
or explicitly set) only local path selection changes -- the on-wire flow
label is unaffected.  Policies 1-3 are left unchanged.

Patch 1 is the kernel change; patch 2 adds selftests covering rehash on
SYN, SYN/ACK, midstream RTO, midstream spurious-retransmission, and PLB
events, plus a policy 1 negative test, a flowlabel-leak regression test,
a dst-rebuild consistency test, and a syncookie path-consistency test.
====================

Link: https://patch.msgid.link/20260615042158.1600746-1-ntspring@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 16:00:00 -07:00
Neil Spring
ae57a55332 selftests: net: add local ECMP rehash test
Add ecmp_rehash.sh with nine scenarios verifying that TCP rehash
selects a different local ECMP path for IPv6:

  - SYN retransmission (forward path blocked during setup)
  - SYN/ACK retransmission (reverse path blocked during setup)
  - Midstream RTO (forward path blocked on established connection)
  - Midstream ACK rehash (reverse path blocked on established connection)
  - PLB rehash (ECN-driven congestion on established connection)
  - Hash policy 1 negative test (rehash attempted but path unchanged)
  - No flowlabel leak (client mp_hash does not alter on-wire flowlabel)
  - Dst rebuild consistency (dst invalidation does not change path)
  - Syncookie server path consistency (SYN-ACK and post-cookie ACKs
    use the same ECMP path)

The policy 1 test verifies that fib_multipath_hash_policy=1 computes
a deterministic 5-tuple hash, so txhash re-rolls do not change the
ECMP path while TcpTimeoutRehash still increments.

The flowlabel leak test sets auto_flowlabels=0 on the client and
installs tc filters on client egress that drop TCP packets with
nonzero flowlabel, confirming that the client's fl6->mp_hash does
not leak into the on-wire IPv6 flow label.

The PLB test needs DCTCP, a restricted congestion control.  Rather
than relax the host-global tcp_allowed_congestion_control (no
per-netns equivalent), it pins dctcp on the test routes via the
congctl route attribute, confined to the test namespaces.

The dst rebuild test streams data, invalidates the cached dst by
adding and removing a dummy route (bumping the fib6_node sernum),
and verifies that traffic stays on the same path.  The sernum change
causes ip6_dst_check() to fail on the next transmit, triggering a
fresh route lookup via inet6_csk_route_socket().
ECMP_REBUILD_ROUNDS=10 repeats the check to reduce the probability
of a buggy kernel passing by chance with 2-way ECMP.

The syncookie server path consistency test verifies that the
server's SYN-ACK and subsequent ACKs use the same ECMP path.
With syncookies, the request socket is freed after the SYN-ACK,
so cookie_tcp_reqsk_init() must derive the same txhash (from the
cookie) that was used for the SYN-ACK's route lookup.

The syncookie test forces tcp_syncookies=2; it skips when
CONFIG_SYN_COOKIES is not available.  selftests/net/config selects
it (and CONFIG_TCP_CONG_DCTCP for the PLB test).

Signed-off-by: Neil Spring <ntspring@meta.com>
Link: https://patch.msgid.link/20260615042158.1600746-3-ntspring@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 15:58:13 -07:00