Add tests that trigger packet drops in cake_enqueue(): "CAKE with QFQ
Parent - CAKE enqueue with packets dropping". It forces CAKE_enqueue to
return NET_XMIT_CN after dropping the packets when it has a QFQ parent.
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20251128001415.377823-3-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add tests to ensure proper backlog accounting in hhf, codel, pie, fq,
fq_pie, and fq_codel qdiscs. We check for the bug pattern originally
found in fq, fq_pie, and fq_codel, which was an underflow in the tbf
parent backlog stats upon child qdisc removal.
Signed-off-by: William Liu <will@willsroot.io>
Reviewed-by: Savino Dicanosa <savy@syst3mfailure.io>
Link: https://patch.msgid.link/20250812235808.45281-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As described in a previous commit [1], Lion's patch [2] revealed an ancient
bug in the qdisc API. Whenever a user tries to add a qdisc to an
invalid parent (not a class, root, or ingress qdisc), the qdisc API will
detect this after qdisc_create is called. Some qdiscs (like fq_codel, pie,
and sfq) call functions (on their init callback) which assume the parent is
valid, so qdisc_create itself may have caused a NULL pointer dereference in
such cases.
This commit creates 3 TDC tests that attempt to add fq_codel, pie and sfq
qdiscs to invalid parents
- Attempts to add an fq_codel qdisc to an hhf qdisc parent
- Attempts to add a pie qdisc to a drr qdisc parent
- Attempts to add an sfq qdisc to an inexistent hfsc classid (which would
belong to a valid hfsc qdisc)
[1] https://lore.kernel.org/all/20250707210801.372995-1-victor@mojatatu.com/
[2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250712145035.705156-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This test reproduces a scenario where HFSC queue length and backlog accounting
can become inconsistent when a peek operation triggers a dequeue and possible
drop before the parent qdisc updates its counters. The test sets up a DRR root
qdisc with an HFSC class, netem, and blackhole children, and uses Scapy to
inject a packet. It helps to verify that HFSC correctly tracks qlen and backlog
even when packets are dropped during peek-induced dequeue.
Cc: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250518222038.58538-3-xiyou.wangcong@gmail.com
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add 5 TDC tests that exercise the reentrant enqueue behaviour in drr,
ets, qfq, and hfsc:
- Test DRR's enqueue reentrant behaviour with netem (which caused a
double list add)
- Test ETS's enqueue reentrant behaviour with netem (which caused a double
list add)
- Test QFQ's enqueue reentrant behaviour with netem (which caused a double
list add)
- Test HFSC's enqueue reentrant behaviour with netem (which caused a UAF)
- Test nested DRR's enqueue reentrant behaviour with netem (which caused a
double list add)
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-6-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a test case to validate the interaction between TBF and SKBPRIO queueing
disciplines, specifically targeting queue length accounting corner cases.
This test complements the fix for the queue length accounting issue in the
SKBPRIO qdisc. This is still best-effort, as timing and manipulating enqueue
and dequeue from user-space is very hard.
Cc: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250329222536.696204-3-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add 3 tests to check for the expected behaviour of
qdisc_tree_reduce_backlog in special scenarios.
- The first test checks if the qdisc class is notified of deletion for
major handle 'ffff:'.
- The second test checks the same as the first test but with 'ffff:' as the root
qdisc.
- The third test checks if everything works if ingress is active.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20241101143148.1218890-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
