This makes a difference for the software scheduling mode, where
dev_queue->qdisc_sleeping is the same as the taprio root Qdisc itself,
but when we're talking about what Qdisc and stats get reported for a
traffic class, the root taprio isn't what comes to mind, but q->qdiscs[]
is.
To understand the difference, I've attempted to send 100 packets in
software mode through class 8001:5, and recorded the stats before and
after the change.
Here is before:
$ tc -s class show dev eth0
class taprio 8001:1 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:2 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:3 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:4 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:5 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:6 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:7 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:8 root leaf 8001:
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
and here is after:
class taprio 8001:1 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:2 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:3 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:4 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:5 root
Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:6 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:7 root
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
class taprio 8001:8 root leaf 800d:
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
window_drops 0
The most glaring (and expected) difference is that before, all class
stats reported the global stats, whereas now, they really report just
the counters for that traffic class.
Finally, Pedro Tammela points out that there is a tc selftest which
checks specifically which handle do the child Qdiscs corresponding to
each class have. That's changing here - taprio no longer reports
tcm->tcm_info as the same handle "1:" as itself (the root Qdisc), but 0
(the handle of the default pfifo child Qdiscs). Since iproute2 does not
print a child Qdisc handle of 0, adjust the test's expected output.
Link: https://lore.kernel.org/netdev/3b83fcf6-a5e8-26fb-8c8a-ec34ec4c3342@mojatatu.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-6-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in commit af7b29b1de ("Revert "net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"") - unlike
mqprio, taprio doesn't use q->qdiscs[] only as a temporary transport
between Qdisc_ops :: init() and Qdisc_ops :: attach().
Delete the comment, which is just stolen from mqprio, but there, the
usage patterns are a lot different, and this is nothing but confusing.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-5-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is another stab at commit 1461d212ab ("net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"), later
reverted in commit af7b29b1de ("Revert "net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"").
I believe that the problems that caused the revert were fixed, and thus,
this change is identical to the original patch.
Its purpose is to properly reject attaching a software taprio child
qdisc to a software taprio parent. Because unoffloaded taprio currently
reports itself (the root Qdisc) as the return value from qdisc_leaf(),
then the process of attaching another taprio as child to a Qdisc class
of the root will just result in a Qdisc_ops :: change() call for the
root. Whereas that's not we want. We want Qdisc_ops :: init() to be
called for the taprio child, in order to give the taprio child a chance
to check whether its sch->parent is TC_H_ROOT or not (and reject this
configuration).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-4-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Normally, Qdiscs have one reference on them held by their owner and one
held for each TXQ to which they are attached, however this is not the
case with the children of an offloaded taprio. Instead, the taprio qdisc
currently lives in the following fragile equilibrium.
In the software scheduling case, taprio attaches itself (the root Qdisc)
to all TXQs, thus having a refcount of 1 + the number of TX queues. In
this mode, the q->qdiscs[] children are not visible directly to the
Qdisc API. The lifetime of the Qdiscs from this private array lasts
until qdisc_destroy() -> taprio_destroy().
In the fully offloaded case, the root taprio has a refcount of 1, and
all child q->qdiscs[] also have a refcount of 1. The child q->qdiscs[]
are attached to the netdev TXQs directly and thus are visible to the
Qdisc API, however taprio loses a reference to them very early - during
qdisc_graft(parent==NULL) -> taprio_attach(). At that time, taprio frees
the q->qdiscs[] array to not leak memory, but interestingly, it does not
release a reference on these qdiscs because it doesn't effectively own
them - they are created by taprio but owned by the Qdisc core, and will
be freed by qdisc_graft(parent==NULL, new==NULL) -> qdisc_put(old) when
the Qdisc is deleted or when the child Qdisc is replaced with something
else.
My interest is to change this equilibrium such that taprio also owns a
reference on the q->qdiscs[] child Qdiscs for the lifetime of the root
Qdisc, including in full offload mode. I want this because I would like
taprio_leaf(), taprio_dump_class(), taprio_dump_class_stats() to have
insight into q->qdiscs[] for the software scheduling mode - currently
they look at dev_queue->qdisc_sleeping, which is, as mentioned, the same
as the root taprio.
The following set of changes is necessary:
- don't free q->qdiscs[] early in taprio_attach(), free it late in
taprio_destroy() for consistency with software mode. But:
- currently that's not possible, because taprio doesn't own a reference
on q->qdiscs[]. So hold that reference - once during the initial
attach() and once during subsequent graft() calls when the child is
changed.
- always keep track of the current child in q->qdiscs[], even for full
offload mode, so that we free in taprio_destroy() what we should, and
not something stale.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a simple code transformation with no intended behavior change,
just to make it absolutely clear that q->qdiscs[] is only attached to
the child taprio classes in full offload mode.
Right now we use the q->qdiscs[] variable in taprio_attach() for
software mode too, but that is quite confusing and avoidable. We use
it only to reach the netdev TX queue, but we could as well just use
netdev_get_tx_queue() for that.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tc flower rules support to classify ESP/AH
packets matching SPI field.
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add extack to warn that delete was rejected because
the class is still in use
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add extack to warn that delete was rejected because
the class is still in use
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add extack to warn that delete was rejected because
the class is still in use
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add extack to warn that delete was rejected because
the class is still in use
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The 'filter_cnt' counter is used to control a Qdisc class lifetime.
Each filter referecing this class by its id will eventually
increment/decrement this counter in their respective
'add/update/delete' routines.
As these operations are always serialized under rtnl lock, we don't
need an atomic type like 'refcount_t'.
It also means that we lose the overflow/underflow checks already
present in refcount_t, which are valuable to hunt down bugs
where the unsigned counter wraps around as it aids automated tools
like syzkaller to scream in such situations.
Wrap the open coded increment/decrement into helper functions and
add overflow checks to the operations.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When route4_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
Fixes: 1109c00547 ("net: sched: RCU cls_route")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-4-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When fw_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
Fixes: e35a8ee599 ("net: sched: fw use RCU")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-3-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When u32_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
Fixes: de5df63228 ("net: sched: cls_u32 changes to knode must appear atomic to readers")
Reported-by: valis <sec@valis.email>
Reported-by: M A Ramdhan <ramdhan@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-2-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
syzkaller found zero division error [0] in div_s64_rem() called from
get_cycle_time_elapsed(), where sched->cycle_time is the divisor.
We have tests in parse_taprio_schedule() so that cycle_time will never
be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed().
The problem is that the types of divisor are different; cycle_time is
s64, but the argument of div_s64_rem() is s32.
syzkaller fed this input and 0x100000000 is cast to s32 to be 0.
@TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000}
We use s64 for cycle_time to cast it to ktime_t, so let's keep it and
set max for cycle_time.
While at it, we prevent overflow in setup_txtime() and add another
test in parse_taprio_schedule() to check if cycle_time overflows.
Also, we add a new tdc test case for this issue.
[0]:
divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline]
RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline]
RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344
Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10
RSP: 0018:ffffc90000acf260 EFLAGS: 00010206
RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000
RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934
R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800
R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
<TASK>
get_packet_txtime net/sched/sch_taprio.c:508 [inline]
taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577
taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658
dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732
__dev_xmit_skb net/core/dev.c:3821 [inline]
__dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
neigh_resolve_output net/core/neighbour.c:1552 [inline]
neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135
__ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196
ip6_finish_output net/ipv6/ip6_output.c:207 [inline]
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228
dst_output include/net/dst.h:458 [inline]
NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303
ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508
ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666
addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175
process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597
worker_thread+0x60f/0x1240 kernel/workqueue.c:2748
kthread+0x2fe/0x3f0 kernel/kthread.c:389
ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308
</TASK>
Modules linked in:
Fixes: 4cfd5779bd ("taprio: Add support for txtime-assist mode")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Co-developed-by: Eric Dumazet <edumazet@google.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sk_getsockopt() runs without locks, we must add annotations
to sk->sk_rcvtimeo and sk->sk_sndtimeo.
In the future we might allow fetching these fields before
we lock the socket in TCP fast path.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A match entry is uniquely identified with an "address" or "path" in the
form of: hashtable ID(12b):bucketid(8b):nodeid(12b).
When creating table match entries all of hash table id, bucket id and
node (match entry id) are needed to be either specified by the user or
reasonable in-kernel defaults are used. The in-kernel default for a table id is
0x800(omnipresent root table); for bucketid it is 0x0. Prior to this fix there
was none for a nodeid i.e. the code assumed that the user passed the correct
nodeid and if the user passes a nodeid of 0 (as Mingi Cho did) then that is what
was used. But nodeid of 0 is reserved for identifying the table. This is not
a problem until we dump. The dump code notices that the nodeid is zero and
assumes it is referencing a table and therefore references table struct
tc_u_hnode instead of what was created i.e match entry struct tc_u_knode.
Ming does an equivalent of:
tc filter add dev dummy0 parent 10: prio 1 handle 0x1000 \
protocol ip u32 match ip src 10.0.0.1/32 classid 10:1 action ok
Essentially specifying a table id 0, bucketid 1 and nodeid of zero
Tableid 0 is remapped to the default of 0x800.
Bucketid 1 is ignored and defaults to 0x00.
Nodeid was assumed to be what Ming passed - 0x000
dumping before fix shows:
~$ tc filter ls dev dummy0 parent 10:
filter protocol ip pref 1 u32 chain 0
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor 1
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor -30591
Note that the last line reports a table instead of a match entry
(you can tell this because it says "ht divisor...").
As a result of reporting the wrong data type (misinterpretting of struct
tc_u_knode as being struct tc_u_hnode) the divisor is reported with value
of -30591. Ming identified this as part of the heap address
(physmap_base is 0xffff8880 (-30591 - 1)).
The fix is to ensure that when table entry matches are added and no
nodeid is specified (i.e nodeid == 0) then we get the next available
nodeid from the table's pool.
After the fix, this is what the dump shows:
$ tc filter ls dev dummy0 parent 10:
filter protocol ip pref 1 u32 chain 0
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor 1
filter protocol ip pref 1 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 10:1 not_in_hw
match 0a000001/ffffffff at 12
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
Reported-by: Mingi Cho <mgcho.minic@gmail.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230726135151.416917-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The nla_for_each_nested parsing in function mqprio_parse_nlattr() does
not check the length of the nested attribute. This can lead to an
out-of-attribute read and allow a malformed nlattr (e.g., length 0) to
be viewed as 8 byte integer and passed to priv->max_rate/min_rate.
This patch adds the check based on nla_len() when check the nla_type(),
which ensures that the length of these two attribute must equals
sizeof(u64).
Fixes: 4e8b86c062 ("mqprio: Introduce new hardware offload mode and shaper in mqprio")
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20230725024227.426561-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current implementation of HTB offload returns the EINVAL error for
quantum parameter. This patch removes the error returning checks for
'quantum' parameter and populates its value to tc_htb_qopt_offload
structure such that driver can use the same.
Add quantum parameter check in mlx5 driver, as mlx5 devices are not capable
of supporting the quantum parameter when htb offload is used. Report error
if quantum parameter is set to a non-default value.
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the following flows, the packets will be dropped if OVS TC offload is
enabled.
'ip,ct_state=-trk,in_port=1 actions=ct(zone=1)'
'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=1)'
'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=2),normal'
In the 1st flow, it finds the exp from the hashtable and removes it then
creates the ct with this exp in act_ct. However, in the 2nd flow it goes
to the OVS upcall at the 1st time. When the skb comes back from userspace,
it has to create the ct again without exp(the exp was removed last time).
With no 'rel' set in the ct, the 3rd flow can never get matched.
In OVS conntrack, it works around it by adding its own exp lookup function
ovs_ct_expect_find() where it doesn't remove the exp. Instead of creating
a real ct, it only updates its keys with the exp and its master info. So
when the skb comes back, the exp is still in the hashtable.
However, we can't do this trick in act_ct, as tc flower match is using a
real ct, and passing the exp and its master info to flower parsing via
tc_skb_cb is also not possible (tc_skb_cb size is not big enough).
The simple and clear fix is to not remove the exp at the 1st flow, namely,
not set IPS_CONFIRMED in tmpl when commit is not set in act_ct.
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This work refactors and adds a lightweight extension ("tcx") to the tc BPF
ingress and egress data path side for allowing BPF program management based
on fds via bpf() syscall through the newly added generic multi-prog API.
The main goal behind this work which we also presented at LPC [0] last year
and a recent update at LSF/MM/BPF this year [3] is to support long-awaited
BPF link functionality for tc BPF programs, which allows for a model of safe
ownership and program detachment.
Given the rise in tc BPF users in cloud native environments, this becomes
necessary to avoid hard to debug incidents either through stale leftover
programs or 3rd party applications accidentally stepping on each others toes.
As a recap, a BPF link represents the attachment of a BPF program to a BPF
hook point. The BPF link holds a single reference to keep BPF program alive.
Moreover, hook points do not reference a BPF link, only the application's
fd or pinning does. A BPF link holds meta-data specific to attachment and
implements operations for link creation, (atomic) BPF program update,
detachment and introspection. The motivation for BPF links for tc BPF programs
is multi-fold, for example:
- From Meta: "It's especially important for applications that are deployed
fleet-wide and that don't "control" hosts they are deployed to. If such
application crashes and no one notices and does anything about that, BPF
program will keep running draining resources or even just, say, dropping
packets. We at FB had outages due to such permanent BPF attachment
semantics. With fd-based BPF link we are getting a framework, which allows
safe, auto-detachable behavior by default, unless application explicitly
opts in by pinning the BPF link." [1]
- From Cilium-side the tc BPF programs we attach to host-facing veth devices
and phys devices build the core datapath for Kubernetes Pods, and they
implement forwarding, load-balancing, policy, EDT-management, etc, within
BPF. Currently there is no concept of 'safe' ownership, e.g. we've recently
experienced hard-to-debug issues in a user's staging environment where
another Kubernetes application using tc BPF attached to the same prio/handle
of cls_bpf, accidentally wiping all Cilium-based BPF programs from underneath
it. The goal is to establish a clear/safe ownership model via links which
cannot accidentally be overridden. [0,2]
BPF links for tc can co-exist with non-link attachments, and the semantics are
in line also with XDP links: BPF links cannot replace other BPF links, BPF
links cannot replace non-BPF links, non-BPF links cannot replace BPF links and
lastly only non-BPF links can replace non-BPF links. In case of Cilium, this
would solve mentioned issue of safe ownership model as 3rd party applications
would not be able to accidentally wipe Cilium programs, even if they are not
BPF link aware.
Earlier attempts [4] have tried to integrate BPF links into core tc machinery
to solve cls_bpf, which has been intrusive to the generic tc kernel API with
extensions only specific to cls_bpf and suboptimal/complex since cls_bpf could
be wiped from the qdisc also. Locking a tc BPF program in place this way, is
getting into layering hacks given the two object models are vastly different.
We instead implemented the tcx (tc 'express') layer which is an fd-based tc BPF
attach API, so that the BPF link implementation blends in naturally similar to
other link types which are fd-based and without the need for changing core tc
internal APIs. BPF programs for tc can then be successively migrated from classic
cls_bpf to the new tc BPF link without needing to change the program's source
code, just the BPF loader mechanics for attaching is sufficient.
For the current tc framework, there is no change in behavior with this change
and neither does this change touch on tc core kernel APIs. The gist of this
patch is that the ingress and egress hook have a lightweight, qdisc-less
extension for BPF to attach its tc BPF programs, in other words, a minimal
entry point for tc BPF. The name tcx has been suggested from discussion of
earlier revisions of this work as a good fit, and to more easily differ between
the classic cls_bpf attachment and the fd-based one.
For the ingress and egress tcx points, the device holds a cache-friendly array
with program pointers which is separated from control plane (slow-path) data.
Earlier versions of this work used priority to determine ordering and expression
of dependencies similar as with classic tc, but it was challenged that for
something more future-proof a better user experience is required. Hence this
resulted in the design and development of the generic attach/detach/query API
for multi-progs. See prior patch with its discussion on the API design. tcx is
the first user and later we plan to integrate also others, for example, one
candidate is multi-prog support for XDP which would benefit and have the same
'look and feel' from API perspective.
The goal with tcx is to have maximum compatibility to existing tc BPF programs,
so they don't need to be rewritten specifically. Compatibility to call into
classic tcf_classify() is also provided in order to allow successive migration
or both to cleanly co-exist where needed given its all one logical tc layer and
the tcx plus classic tc cls/act build one logical overall processing pipeline.
tcx supports the simplified return codes TCX_NEXT which is non-terminating (go
to next program) and terminating ones with TCX_PASS, TCX_DROP, TCX_REDIRECT.
The fd-based API is behind a static key, so that when unused the code is also
not entered. The struct tcx_entry's program array is currently static, but
could be made dynamic if necessary at a point in future. The a/b pair swap
design has been chosen so that for detachment there are no allocations which
otherwise could fail.
The work has been tested with tc-testing selftest suite which all passes, as
well as the tc BPF tests from the BPF CI, and also with Cilium's L4LB.
Thanks also to Nikolay Aleksandrov and Martin Lau for in-depth early reviews
of this work.
[0] https://lpc.events/event/16/contributions/1353/
[1] https://lore.kernel.org/bpf/CAEf4BzbokCJN33Nw_kg82sO=xppXnKWEncGTWCTB9vGCmLB6pw@mail.gmail.com
[2] https://colocatedeventseu2023.sched.com/event/1Jo6O/tales-from-an-ebpf-programs-murder-mystery-hemanth-malla-guillaume-fournier-datadog
[3] http://vger.kernel.org/bpfconf2023_material/tcx_meta_netdev_borkmann.pdf
[4] https://lore.kernel.org/bpf/20210604063116.234316-1-memxor@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If TCA_FLOWER_CLASSID is specified in the netlink message, the code will
call tcf_bind_filter. However, if any error occurs after that, the code
should undo this by calling tcf_unbind_filter.
Fixes: 77b9900ef5 ("tc: introduce Flower classifier")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If cls_bpf_offload errors out, we must also undo tcf_bind_filter that
was done before the error.
Fix that by calling tcf_unbind_filter in errout_parms.
Fixes: eadb41489f ("net: cls_bpf: add support for marking filters as hardware-only")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the case of an update, when TCA_U32_LINK is set, u32_set_parms will
decrement the refcount of the ht_down (struct tc_u_hnode) pointer
present in the older u32 filter which we are replacing. However, if
u32_replace_hw_knode errors out, the update command fails and that
ht_down pointer continues decremented. To fix that, when
u32_replace_hw_knode fails, check if ht_down's refcount was decremented
and undo the decrement.
Fixes: d34e3e1813 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When u32_replace_hw_knode fails, we need to undo the tcf_bind_filter
operation done at u32_set_parms.
Fixes: d34e3e1813 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case an error occurred after mall_set_parms executed successfully, we
must undo the tcf_bind_filter call it issues.
Fix that by calling tcf_unbind_filter in err_replace_hw_filter label.
Fixes: ec2507d2a3 ("net/sched: cls_matchall: Fix error path")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lion says:
-------
In the QFQ scheduler a similar issue to CVE-2023-31436
persists.
Consider the following code in net/sched/sch_qfq.c:
static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
unsigned int len = qdisc_pkt_len(skb), gso_segs;
// ...
if (unlikely(cl->agg->lmax < len)) {
pr_debug("qfq: increasing maxpkt from %u to %u for class %u",
cl->agg->lmax, len, cl->common.classid);
err = qfq_change_agg(sch, cl, cl->agg->class_weight, len);
if (err) {
cl->qstats.drops++;
return qdisc_drop(skb, sch, to_free);
}
// ...
}
Similarly to CVE-2023-31436, "lmax" is increased without any bounds
checks according to the packet length "len". Usually this would not
impose a problem because packet sizes are naturally limited.
This is however not the actual packet length, rather the
"qdisc_pkt_len(skb)" which might apply size transformations according to
"struct qdisc_size_table" as created by "qdisc_get_stab()" in
net/sched/sch_api.c if the TCA_STAB option was set when modifying the qdisc.
A user may choose virtually any size using such a table.
As a result the same issue as in CVE-2023-31436 can occur, allowing heap
out-of-bounds read / writes in the kmalloc-8192 cache.
-------
We can create the issue with the following commands:
tc qdisc add dev $DEV root handle 1: stab mtu 2048 tsize 512 mpu 0 \
overhead 999999999 linklayer ethernet qfq
tc class add dev $DEV parent 1: classid 1:1 htb rate 6mbit burst 15k
tc filter add dev $DEV parent 1: matchall classid 1:1
ping -I $DEV 1.1.1.2
This is caused by incorrectly assuming that qdisc_pkt_len() returns a
length within the QFQ_MIN_LMAX < len < QFQ_MAX_LMAX.
Fixes: 462dbc9101 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: Lion <nnamrec@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
25369891fc deletes a check for the case where no 'lmax' is
specified which 3037933448 previously fixed as 'lmax'
could be set to the device's MTU without any bound checking
for QFQ_LMAX_MIN and QFQ_LMAX_MAX. Therefore, reintroduce the check.
Fixes: 25369891fc ("net/sched: sch_qfq: refactor parsing of netlink parameters")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The kernel does not currently validate that both the minimum and maximum
ports of a port range are specified. This can lead user space to think
that a filter matching on a port range was successfully added, when in
fact it was not. For example, with a patched (buggy) iproute2 that only
sends the minimum port, the following commands do not return an error:
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp src_port 100-200 action pass
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp dst_port 100-200 action pass
# tc filter show dev swp1 ingress
filter protocol ip pref 1 flower chain 0
filter protocol ip pref 1 flower chain 0 handle 0x1
eth_type ipv4
ip_proto udp
not_in_hw
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
filter protocol ip pref 1 flower chain 0 handle 0x2
eth_type ipv4
ip_proto udp
not_in_hw
action order 1: gact action pass
random type none pass val 0
index 2 ref 1 bind 1
Fix by returning an error unless both ports are specified:
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp src_port 100-200 action pass
Error: Both min and max source ports must be specified.
We have an error talking to the kernel
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp dst_port 100-200 action pass
Error: Both min and max destination ports must be specified.
We have an error talking to the kernel
Fixes: 5c72299fba ("net: sched: cls_flower: Classify packets using port ranges")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the event of a failure in tcf_change_indev(), fw_set_parms() will
immediately return an error after incrementing or decrementing
reference counter in tcf_bind_filter(). If attacker can control
reference counter to zero and make reference freed, leading to
use after free.
In order to prevent this, move the point of possible failure above the
point where the TC_FW_CLASSID is handled.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: M A Ramdhan <ramdhan@starlabs.sg>
Signed-off-by: M A Ramdhan <ramdhan@starlabs.sg>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Message-ID: <20230705161530.52003-1-ramdhan@starlabs.sg>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The attribute TCA_PEDIT_PARMS_EX is not be included in pedit_policy and
one malicious user could fake a TCA_PEDIT_PARMS_EX whose length is
smaller than the intended sizeof(struct tc_pedit). Hence, the
dereference in tcf_pedit_init() could access dirty heap data.
static int tcf_pedit_init(...)
{
// ...
pattr = tb[TCA_PEDIT_PARMS]; // TCA_PEDIT_PARMS is included
if (!pattr)
pattr = tb[TCA_PEDIT_PARMS_EX]; // but this is not
// ...
parm = nla_data(pattr);
index = parm->index; // parm is able to be smaller than 4 bytes
// and this dereference gets dirty skb_buff
// data created in netlink_sendmsg
}
This commit adds TCA_PEDIT_PARMS_EX length in pedit_policy which avoid
the above case, just like the TCA_PEDIT_PARMS.
Fixes: 71d0ed7079 ("net/act_pedit: Support using offset relative to the conventional network headers")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://lore.kernel.org/r/20230703110842.590282-1-linma@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
xtables relies on skb being owned by ip stack, i.e. with ipv4
check in place skb->cb is supposed to be IPCB.
I don't see an immediate problem (REJECT target cannot be used anymore
now that PRE/POSTROUTING hook validation has been fixed), but better be
safe than sorry.
A much better patch would be to either mark act_ipt as
"depends on BROKEN" or remove it altogether. I plan to do this
for -next in the near future.
This tc extension is broken in the sense that tc lacks an
equivalent of NF_STOLEN verdict.
With NF_STOLEN, target function takes complete ownership of skb, caller
cannot dereference it anymore.
ACT_STOLEN cannot be used for this: it has a different meaning, caller
is allowed to dereference the skb.
At this time NF_STOLEN won't be returned by any targets as far as I can
see, but this may change in the future.
It might be possible to work around this via list of allowed
target extensions known to only return DROP or ACCEPT verdicts, but this
is error prone/fragile.
Existing selftest only validates xt_LOG and act_ipt is restricted
to ipv4 so I don't think this action is used widely.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Netfilter targets make assumptions on the skb state, for example
iphdr is supposed to be in the linear area.
This is normally done by IP stack, but in act_ipt case no
such checks are made.
Some targets can even assume that skb_dst will be valid.
Make a minimum effort to check for this:
- Don't call the targets eval function for non-ipv4 skbs.
- Don't call the targets eval function for POSTROUTING
emulation when the skb has no dst set.
v3: use skb_protocol helper (Davide Caratti)
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Looks like "tc" hard-codes "mangle" as the only supported table
name, but on kernel side there are no checks.
This is wrong. Not all xtables targets are safe to call from tc.
E.g. "nat" targets assume skb has a conntrack object assigned to it.
Normally those get called from netfilter nat core which consults the
nat table to obtain the address mapping.
"tc" userspace either sets PRE or POSTROUTING as hook number, but there
is no validation of this on kernel side, so update netlink policy to
reject bogus numbers. Some targets may assume skb_dst is set for
input/forward hooks, so prevent those from being used.
act_ipt uses the hook number in two places:
1. the state hook number, this is fine as-is
2. to set par.hook_mask
The latter is a bit mask, so update the assignment to make
xt_check_target() to the right thing.
Followup patch adds required checks for the skb/packet headers before
calling the targets evaluation function.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In blamed commit, I missed that get_dist_table() was allocating
memory using GFP_KERNEL, and acquiring qdisc lock to perform
the swap of newly allocated table with current one.
In this patch, get_dist_table() is allocating memory and
copy user data before we acquire the qdisc lock.
Then we perform swap operations while being protected by the lock.
Note that after this patch netem_change() no longer can do partial changes.
If an error is returned, qdisc conf is left unchanged.
Fixes: 2174a08db8 ("sch_netem: acquire qdisc lock in netem_change()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230622181503.2327695-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Mingshuai Ren reports:
When a new chain is added by using tc, one soft lockup alarm will be
generated after delete the prio 0 filter of the chain. To reproduce
the problem, perform the following steps:
(1) tc qdisc add dev eth0 root handle 1: htb default 1
(2) tc chain add dev eth0
(3) tc filter del dev eth0 chain 0 parent 1: prio 0
(4) tc filter add dev eth0 chain 0 parent 1:
Fix the issue by accounting for additional reference to chains that are
explicitly created by RTM_NEWCHAIN message as opposed to implicitly by
RTM_NEWTFILTER message.
Fixes: 726d061286 ("net: sched: prevent insertion of new classifiers during chain flush")
Reported-by: Mingshuai Ren <renmingshuai@huawei.com>
Closes: https://lore.kernel.org/lkml/87legswvi3.fsf@nvidia.com/T/
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Link: https://lore.kernel.org/r/20230612093426.2867183-1-vladbu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mini_Qdisc_pair::p_miniq is a double pointer to mini_Qdisc, initialized
in ingress_init() to point to net_device::miniq_ingress. ingress Qdiscs
access this per-net_device pointer in mini_qdisc_pair_swap(). Similar
for clsact Qdiscs and miniq_egress.
Unfortunately, after introducing RTNL-unlocked RTM_{NEW,DEL,GET}TFILTER
requests (thanks Hillf Danton for the hint), when replacing ingress or
clsact Qdiscs, for example, the old Qdisc ("@old") could access the same
miniq_{in,e}gress pointer(s) concurrently with the new Qdisc ("@new"),
causing race conditions [1] including a use-after-free bug in
mini_qdisc_pair_swap() reported by syzbot:
BUG: KASAN: slab-use-after-free in mini_qdisc_pair_swap+0x1c2/0x1f0 net/sched/sch_generic.c:1573
Write of size 8 at addr ffff888045b31308 by task syz-executor690/14901
...
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319
print_report mm/kasan/report.c:430 [inline]
kasan_report+0x11c/0x130 mm/kasan/report.c:536
mini_qdisc_pair_swap+0x1c2/0x1f0 net/sched/sch_generic.c:1573
tcf_chain_head_change_item net/sched/cls_api.c:495 [inline]
tcf_chain0_head_change.isra.0+0xb9/0x120 net/sched/cls_api.c:509
tcf_chain_tp_insert net/sched/cls_api.c:1826 [inline]
tcf_chain_tp_insert_unique net/sched/cls_api.c:1875 [inline]
tc_new_tfilter+0x1de6/0x2290 net/sched/cls_api.c:2266
...
@old and @new should not affect each other. In other words, @old should
never modify miniq_{in,e}gress after @new, and @new should not update
@old's RCU state.
Fixing without changing sch_api.c turned out to be difficult (please
refer to Closes: for discussions). Instead, make sure @new's first call
always happen after @old's last call (in {ingress,clsact}_destroy()) has
finished:
In qdisc_graft(), return -EBUSY if @old has any ongoing filter requests,
and call qdisc_destroy() for @old before grafting @new.
Introduce qdisc_refcount_dec_if_one() as the counterpart of
qdisc_refcount_inc_nz() used for filter requests. Introduce a
non-static version of qdisc_destroy() that does a TCQ_F_BUILTIN check,
just like qdisc_put() etc.
Depends on patch "net/sched: Refactor qdisc_graft() for ingress and
clsact Qdiscs".
[1] To illustrate, the syzkaller reproducer adds ingress Qdiscs under
TC_H_ROOT (no longer possible after commit c7cfbd1150 ("net/sched:
sch_ingress: Only create under TC_H_INGRESS")) on eth0 that has 8
transmission queues:
Thread 1 creates ingress Qdisc A (containing mini Qdisc a1 and a2),
then adds a flower filter X to A.
Thread 2 creates another ingress Qdisc B (containing mini Qdisc b1 and
b2) to replace A, then adds a flower filter Y to B.
Thread 1 A's refcnt Thread 2
RTM_NEWQDISC (A, RTNL-locked)
qdisc_create(A) 1
qdisc_graft(A) 9
RTM_NEWTFILTER (X, RTNL-unlocked)
__tcf_qdisc_find(A) 10
tcf_chain0_head_change(A)
mini_qdisc_pair_swap(A) (1st)
|
| RTM_NEWQDISC (B, RTNL-locked)
RCU sync 2 qdisc_graft(B)
| 1 notify_and_destroy(A)
|
tcf_block_release(A) 0 RTM_NEWTFILTER (Y, RTNL-unlocked)
qdisc_destroy(A) tcf_chain0_head_change(B)
tcf_chain0_head_change_cb_del(A) mini_qdisc_pair_swap(B) (2nd)
mini_qdisc_pair_swap(A) (3rd) |
... ...
Here, B calls mini_qdisc_pair_swap(), pointing eth0->miniq_ingress to
its mini Qdisc, b1. Then, A calls mini_qdisc_pair_swap() again during
ingress_destroy(), setting eth0->miniq_ingress to NULL, so ingress
packets on eth0 will not find filter Y in sch_handle_ingress().
This is just one of the possible consequences of concurrently accessing
miniq_{in,e}gress pointers.
Fixes: 7a096d579e ("net: sched: ingress: set 'unlocked' flag for Qdisc ops")
Fixes: 87f373921c ("net: sched: ingress: set 'unlocked' flag for clsact Qdisc ops")
Reported-by: syzbot+b53a9c0d1ea4ad62da8b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/0000000000006cf87705f79acf1a@google.com/
Cc: Hillf Danton <hdanton@sina.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Grafting ingress and clsact Qdiscs does not need a for-loop in
qdisc_graft(). Refactor it. No functional changes intended.
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently UNREPLIED and UNASSURED connections are added to the nf flow
table. This causes the following connection packets to be processed
by the flow table which then skips conntrack_in(), and thus such the
connections will remain UNREPLIED and UNASSURED even if reply traffic
is then seen. Even still, the unoffloaded reply packets are the ones
triggering hardware update from new to established state, and if
there aren't any to triger an update and/or previous update was
missed, hardware can get out of sync with sw and still mark
packets as new.
Fix the above by:
1) Not skipping conntrack_in() for UNASSURED packets, but still
refresh for hardware, as before the cited patch.
2) Try and force a refresh by reply-direction packets that update
the hardware rules from new to established state.
3) Remove any bidirectional flows that didn't failed to update in
hardware for re-insertion as bidrectional once any new packet
arrives.
Fixes: 6a9bad0069 ("net/sched: act_ct: offload UDP NEW connections")
Co-developed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/1686313379-117663-1-git-send-email-paulb@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add support to the tc flower classifier to match based on fields in CFM
information elements like level and opcode.
tc filter add dev ens6 ingress protocol 802.1q \
flower vlan_id 698 vlan_ethtype 0x8902 cfm mdl 5 op 46 \
action drop
Signed-off-by: Zahari Doychev <zdoychev@maxlinear.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The taprio Qdisc creates child classes per netdev TX queue, but
taprio_dump_class_stats() currently reports offload statistics per
traffic class. Traffic classes are groups of TXQs sharing the same
dequeue priority, so this is incorrect and we shouldn't be bundling up
the TXQ stats when reporting them, as we currently do in enetc.
Modify the API from taprio to drivers such that they report TXQ offload
stats and not TC offload stats.
There is no change in the UAPI or in the global Qdisc stats.
Fixes: 6c1adb650c ("net/sched: taprio: add netlink reporting for offload statistics counters")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
./net/sched/act_pedit.c:245:21-28: WARNING opportunity for kmemdup.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5478
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move declarations into include/net/gso.h and code into net/core/gso.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In the event of a failure in tcf_change_indev(), u32_set_parms() will
immediately return without decrementing the recently incremented
reference counter. If this happens enough times, the counter will
rollover and the reference freed, leading to a double free which can be
used to do 'bad things'.
In order to prevent this, move the point of possible failure above the
point where the reference counter is incremented. Also save any
meaningful return values to be applied to the return data at the
appropriate point in time.
This issue was caught with KASAN.
Fixes: 705c709126 ("net: sched: cls_u32: no need to call tcf_exts_change for newly allocated struct")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As shown in [1], out-of-bounds access occurs in two cases:
1)when the qdisc of the taprio type is used to replace the previously
configured taprio, count and offset in tc_to_txq can be set to 0. In this
case, the value of *txq in taprio_next_tc_txq() will increases
continuously. When the number of accessed queues exceeds the number of
queues on the device, out-of-bounds access occurs.
2)When packets are dequeued, taprio can be deleted. In this case, the tc
rule of dev is cleared. The count and offset values are also set to 0. In
this case, out-of-bounds access is also caused.
Now the restriction on the queue number is added.
[1] https://groups.google.com/g/syzkaller-bugs/c/_lYOKgkBVMg
Fixes: 2f530df76c ("net/sched: taprio: give higher priority to higher TCs in software dequeue mode")
Reported-by: syzbot+04afcb3d2c840447559a@syzkaller.appspotmail.com
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of relying on skb->transport_header being set correctly, opt
instead to parse the L3 header length out of the L3 headers for both
IPv4/IPv6 when the Extended Layer Op for tcp/udp is used. This fixes a
bug if GRO is disabled, when GRO is disabled skb->transport_header is
set by __netif_receive_skb_core() to point to the L3 header, it's later
fixed by the upper protocol layers, but act_pedit will receive the SKB
before the fixups are completed. The existing behavior causes the
following to edit the L3 header if GRO is disabled instead of the UDP
header:
tc filter add dev eth0 ingress protocol ip flower ip_proto udp \
dst_ip 192.168.1.3 action pedit ex munge udp set dport 18053
Also re-introduce a rate-limited warning if we were unable to extract
the header offset when using the 'ex' interface.
Fixes: 71d0ed7079 ("net/act_pedit: Support using offset relative to
the conventional network headers")
Signed-off-by: Max Tottenham <mtottenh@akamai.com>
Reviewed-by: Josh Hunt <johunt@akamai.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305261541.N165u9TZ-lkp@intel.com/
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/sch_taprio.c
d636fc5dd6 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
dced11ef84 ("net/sched: taprio: don't overwrite "sch" variable in taprio_dump_class_stats()")
net/ipv4/sysctl_net_ipv4.c
e209fee411 ("net/ipv4: ping_group_range: allow GID from 2147483648 to 4294967294")
ccce324dab ("tcp: make the first N SYN RTO backoffs linear")
https://lore.kernel.org/all/20230605100816.08d41a7b@canb.auug.org.au/
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
try_module_get will be called in tcf_proto_lookup_ops. So module_put needs
to be called to drop the refcount if ops don't implement the required
function.
Fixes: 9f407f1768 ("net: sched: introduce chain templates")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes following sparse errors:
net/sched/act_police.c:360:28: warning: dereference of noderef expression
net/sched/act_police.c:362:45: warning: dereference of noderef expression
net/sched/act_police.c:362:45: warning: dereference of noderef expression
net/sched/act_police.c:368:28: warning: dereference of noderef expression
net/sched/act_police.c:370:45: warning: dereference of noderef expression
net/sched/act_police.c:370:45: warning: dereference of noderef expression
net/sched/act_police.c:376:45: warning: dereference of noderef expression
net/sched/act_police.c:376:45: warning: dereference of noderef expression
Fixes: d1967e495a ("net_sched: act_police: add 2 new attributes to support police 64bit rate and peakrate")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rtm_tca_policy is used from net/sched/sch_api.c and net/sched/cls_api.c,
thus should be declared in an include file.
This fixes the following sparse warning:
net/sched/sch_api.c:1434:25: warning: symbol 'rtm_tca_policy' was not declared. Should it be static?
Fixes: e331473fee ("net/sched: cls_api: add missing validation of netlink attributes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes the following sparse warning:
net/sched/sch_api.c:2305:1: sparse: warning: symbol 'tc_skip_wrapper' was not declared. Should it be static?
No functional change intended.
Signed-off-by: Min-Hua Chen <minhuadotchen@gmail.com>
Acked-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we send two TCA_FLOWER_KEY_ENC_OPTS_GENEVE packets and their total
size is 252 bytes(key->enc_opts.len = 252) then
key->enc_opts.len = opt->length = data_len / 4 = 0 when the third
TCA_FLOWER_KEY_ENC_OPTS_GENEVE packet enters fl_set_geneve_opt. This
bypasses the next bounds check and results in an out-of-bounds.
Fixes: 0a6e77784f ("net/sched: allow flower to match tunnel options")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Link: https://lore.kernel.org/r/20230531102805.27090-1-hbh25y@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Offloading drivers may report some additional statistics counters, some
of them even suggested by 802.1Q, like TransmissionOverrun.
In my opinion we don't have to limit ourselves to reporting counters
only globally to the Qdisc/interface, especially if the device has more
detailed reporting (per traffic class), since the more detailed info is
valuable for debugging and can help identifying who is exceeding its
time slot.
But on the other hand, some devices may not be able to report both per
TC and global stats.
So we end up reporting both ways, and use the good old ethtool_put_stat()
strategy to determine which statistics are supported by this NIC.
Statistics which aren't set are simply not reported to netlink. For this
reason, we need something dynamic (a nlattr nest) to be reported through
TCA_STATS_APP, and not something daft like the fixed-size and
inextensible struct tc_codel_xstats. A good model for xstats which are a
nlattr nest rather than a fixed struct seems to be cake.
# Global stats
$ tc -s qdisc show dev eth0 root
# Per-tc stats
$ tc -s class show dev eth0
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Inspired from struct flow_cls_offload :: cmd, in order for taprio to be
able to report statistics (which is future work), it seems that we need
to drill one step further with the ndo_setup_tc(TC_SETUP_QDISC_TAPRIO)
multiplexing, and pass the command as part of the common portion of the
muxed structure.
Since we already have an "enable" variable in tc_taprio_qopt_offload,
refactor all drivers to check for "cmd" instead of "enable", and reject
every other command except "replace" and "destroy" - to be future proof.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com> # for lan966x
Acked-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In taprio_dump_class_stats() we don't need a reference to the root Qdisc
once we get the reference to the child corresponding to this traffic
class, so it's okay to overwrite "sch". But in a future patch we will
need the root Qdisc too, so create a dedicated "child" pointer variable
to hold the child reference. This also makes the code adhere to a more
conventional coding style.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the 'TCA_FLOWER_L2_MISS' netlink attribute that allows user space to
match on packets that encountered a layer 2 miss. The miss indication is
set as metadata in the tc skb extension by the bridge driver upon FDB or
MDB lookup miss and dissected by the flow dissector to the
'FLOW_DISSECTOR_KEY_META' key.
The use of this skb extension is guarded by the 'tc_skb_ext_tc' static
key. As such, enable / disable this key when filters that match on layer
2 miss are added / deleted.
Tested:
# cat tc_skb_ext_tc.py
#!/usr/bin/env -S drgn -s vmlinux
refcount = prog["tc_skb_ext_tc"].key.enabled.counter.value_()
print(f"tc_skb_ext_tc reference count is {refcount}")
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 0
# tc filter add dev swp1 egress proto all handle 101 pref 1 flower src_mac 00:11:22:33:44:55 action drop
# tc filter add dev swp1 egress proto all handle 102 pref 2 flower src_mac 00:11:22:33:44:55 l2_miss true action drop
# tc filter add dev swp1 egress proto all handle 103 pref 3 flower src_mac 00:11:22:33:44:55 l2_miss false action drop
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 2
# tc filter replace dev swp1 egress proto all handle 102 pref 2 flower src_mac 00:01:02:03:04:05 l2_miss false action drop
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 2
# tc filter del dev swp1 egress proto all handle 103 pref 3 flower
# tc filter del dev swp1 egress proto all handle 102 pref 2 flower
# tc filter del dev swp1 egress proto all handle 101 pref 1 flower
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 0
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When use the following command to test:
1)ip link add bond0 type bond
2)ip link set bond0 up
3)tc qdisc add dev bond0 root handle ffff: mq
4)tc qdisc replace dev bond0 parent ffff:fff1 handle ffff: mq
The kernel reports NULL pointer dereference issue. The stack information
is as follows:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Internal error: Oops: 0000000096000006 [#1] SMP
Modules linked in:
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mq_attach+0x44/0xa0
lr : qdisc_graft+0x20c/0x5cc
sp : ffff80000e2236a0
x29: ffff80000e2236a0 x28: ffff0000c0e59d80 x27: ffff0000c0be19c0
x26: ffff0000cae3e800 x25: 0000000000000010 x24: 00000000fffffff1
x23: 0000000000000000 x22: ffff0000cae3e800 x21: ffff0000c9df4000
x20: ffff0000c9df4000 x19: 0000000000000000 x18: ffff80000a934000
x17: ffff8000f5b56000 x16: ffff80000bb08000 x15: 0000000000000000
x14: 0000000000000000 x13: 6b6b6b6b6b6b6b6b x12: 6b6b6b6b00000001
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff0000c0be0730 x7 : bbbbbbbbbbbbbbbb x6 : 0000000000000008
x5 : ffff0000cae3e864 x4 : 0000000000000000 x3 : 0000000000000001
x2 : 0000000000000001 x1 : ffff8000090bc23c x0 : 0000000000000000
Call trace:
mq_attach+0x44/0xa0
qdisc_graft+0x20c/0x5cc
tc_modify_qdisc+0x1c4/0x664
rtnetlink_rcv_msg+0x354/0x440
netlink_rcv_skb+0x64/0x144
rtnetlink_rcv+0x28/0x34
netlink_unicast+0x1e8/0x2a4
netlink_sendmsg+0x308/0x4a0
sock_sendmsg+0x64/0xac
____sys_sendmsg+0x29c/0x358
___sys_sendmsg+0x90/0xd0
__sys_sendmsg+0x7c/0xd0
__arm64_sys_sendmsg+0x2c/0x38
invoke_syscall+0x54/0x114
el0_svc_common.constprop.1+0x90/0x174
do_el0_svc+0x3c/0xb0
el0_svc+0x24/0xec
el0t_64_sync_handler+0x90/0xb4
el0t_64_sync+0x174/0x178
This is because when mq is added for the first time, qdiscs in mq is set
to NULL in mq_attach(). Therefore, when replacing mq after adding mq, we
need to initialize qdiscs in the mq before continuing to graft. Otherwise,
it will couse NULL pointer dereference issue in mq_attach(). And the same
issue will occur in the attach functions of mqprio, taprio and htb.
ffff:fff1 means that the repalce qdisc is ingress. Ingress does not allow
any qdisc to be attached. Therefore, ffff:fff1 is incorrectly used, and
the command should be dropped.
Fixes: 6ec1c69a8f ("net_sched: add classful multiqueue dummy scheduler")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Tested-by: Peilin Ye <peilin.ye@bytedance.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230527093747.3583502-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, after creating an ingress (or clsact) Qdisc and grafting it
under TC_H_INGRESS (TC_H_CLSACT), it is possible to graft it again under
e.g. a TBF Qdisc:
$ ip link add ifb0 type ifb
$ tc qdisc add dev ifb0 handle 1: root tbf rate 20kbit buffer 1600 limit 3000
$ tc qdisc add dev ifb0 clsact
$ tc qdisc link dev ifb0 handle ffff: parent 1:1
$ tc qdisc show dev ifb0
qdisc tbf 1: root refcnt 2 rate 20Kbit burst 1600b lat 560.0ms
qdisc clsact ffff: parent ffff:fff1 refcnt 2
^^^^^^^^
clsact's refcount has increased: it is now grafted under both
TC_H_CLSACT and 1:1.
ingress and clsact Qdiscs should only be used under TC_H_INGRESS
(TC_H_CLSACT). Prohibit regrafting them.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: 1f211a1b92 ("net, sched: add clsact qdisc")
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently it is possible to add e.g. an HTB Qdisc under ffff:fff1
(TC_H_INGRESS, TC_H_CLSACT):
$ ip link add name ifb0 type ifb
$ tc qdisc add dev ifb0 parent ffff:fff1 htb
$ tc qdisc add dev ifb0 clsact
Error: Exclusivity flag on, cannot modify.
$ drgn
...
>>> ifb0 = netdev_get_by_name(prog, "ifb0")
>>> qdisc = ifb0.ingress_queue.qdisc_sleeping
>>> print(qdisc.ops.id.string_().decode())
htb
>>> qdisc.flags.value_() # TCQ_F_INGRESS
2
Only allow ingress and clsact Qdiscs under ffff:fff1. Return -EINVAL
for everything else. Make TCQ_F_INGRESS a static flag of ingress and
clsact Qdiscs.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: 1f211a1b92 ("net, sched: add clsact qdisc")
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
clsact Qdiscs are only supposed to be created under TC_H_CLSACT (which
equals TC_H_INGRESS). Return -EOPNOTSUPP if 'parent' is not
TC_H_CLSACT.
Fixes: 1f211a1b92 ("net, sched: add clsact qdisc")
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ingress Qdiscs are only supposed to be created under TC_H_INGRESS.
Return -EOPNOTSUPP if 'parent' is not TC_H_INGRESS, similar to
mq_init().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+b53a9c0d1ea4ad62da8b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/0000000000006cf87705f79acf1a@google.com/
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current implementation of HTB offload returns the EINVAL error
for unsupported parameters like prio and quantum. This patch removes
the error returning checks for 'prio' parameter and populates its
value to tc_htb_qopt_offload structure such that driver can use the
same.
Add prio parameter check in mlx5 driver, as mlx5 devices are not capable
of supporting the prio parameter when htb offload is used. Report error
if prio parameter is set to a non-default value.
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Co-developed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When replacing a filter (i.e. 'fold' pointer is not NULL) the insertion of
new filter to idr is postponed until later in code since handle is already
provided by the user. However, the error handling code in fl_change()
always assumes that the new filter had been inserted into idr. If error
handler is reached when replacing existing filter it may remove it from idr
therefore making it unreachable for delete or dump afterwards. Fix the
issue by verifying that 'fold' argument wasn't provided by caller before
calling idr_remove().
Fixes: 08a0063df3 ("net/sched: flower: Move filter handle initialization earlier")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 32eff6bace.
Superseded by the following commit in this series.
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are cases where the device is adminstratively UP, but operationally
down. For example, we have a physical device (Nvidia ConnectX-6 Dx, 25Gbps)
who's cable was pulled out, here is its ip link output:
5: ens2f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
link/ether b8:ce:f6:4b:68:35 brd ff:ff:ff:ff:ff:ff
altname enp179s0f1np1
As you can see, it's administratively UP but operationally down.
In this case, sending a packet to this port caused a nasty kernel hang (so
nasty that we were unable to capture it). Aborting a transmit based on
operational status (in addition to administrative status) fixes the issue.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
v1->v2: Add fixes tag
v2->v3: Remove blank line between tags + add change log, suggested by Leon
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 08a0063df3 ("net/sched: flower: Move filter handle initialization
earlier") moved filter handle initialization but an assignment of
the handle to fnew->handle is done regardless of fold value. This is wrong
because if fold != NULL (so fold->handle == handle) no new handle is
allocated and passed handle is assigned to fnew->handle. Then if any
subsequent action in fl_change() fails then the handle value is
removed from IDR that is incorrect as we will have still valid old filter
instance with handle that is not present in IDR.
Fix this issue by moving the assignment so it is done only when passed
fold == NULL.
Prior the patch:
[root@machine tc-testing]# ./tdc.py -d enp1s0f0np0 -e 14be
Test 14be: Concurrently replace same range of 100k flower filters from 10 tc instances
exit: 123
exit: 0
RTNETLINK answers: Invalid argument
We have an error talking to the kernel
Command failed tmp/replace_6:1885
All test results:
1..1
not ok 1 14be - Concurrently replace same range of 100k flower filters from 10 tc instances
Command exited with 123, expected 0
RTNETLINK answers: Invalid argument
We have an error talking to the kernel
Command failed tmp/replace_6:1885
After the patch:
[root@machine tc-testing]# ./tdc.py -d enp1s0f0np0 -e 14be
Test 14be: Concurrently replace same range of 100k flower filters from 10 tc instances
All test results:
1..1
ok 1 14be - Concurrently replace same range of 100k flower filters from 10 tc instances
Fixes: 08a0063df3 ("net/sched: flower: Move filter handle initialization earlier")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230425140604.169881-1-ivecera@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Two parameters can be transformed into netlink policies and
validated while parsing the netlink message.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some error messages are still being printed to dmesg.
Since extack is available, provide error messages there.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some error messages are still being printed to dmesg.
Since extack is available, provide error messages there.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unbounded info messages in the pedit datapath can flood the printk
ring buffer quite easily depending on the action created.
As these messages are informational, usually printing some, not all,
is enough to bring attention to the real issue.
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netlink parsing already validates the key 'htype'.
Remove the datapath check as it's redundant.
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Static key offsets should always be on 32 bit boundaries. Validate them on
create/update time for static offsets and move the datapath validation
for runtime offsets only.
iproute2 already errors out if a given offset and data size cannot be
packed to a 32 bit boundary. This change will make sure users which
create/update pedit instances directly via netlink also error out,
instead of finding out when packets are traversing.
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have extack available when parsing 'ex' keys, so pass it to
tcf_pedit_keys_ex_parse and add more detailed error messages.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transform two checks in the 'ex' key parsing into netlink policies
removing extra if checks.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The kernel will print several warnings in a short period of time
when it stalls. Like this:
First warning:
[ 7100.097547] ------------[ cut here ]------------
[ 7100.097550] NETDEV WATCHDOG: eno2 (xxx): transmit queue 8 timed out
[ 7100.097571] WARNING: CPU: 8 PID: 0 at net/sched/sch_generic.c:467
dev_watchdog+0x260/0x270
...
Second warning:
[ 7147.756952] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 7147.756958] rcu: 24-....: (59999 ticks this GP) idle=546/1/0x400000000000000
softirq=367 3137/3673146 fqs=13844
[ 7147.756960] (t=60001 jiffies g=4322709 q=133381)
[ 7147.756962] NMI backtrace for cpu 24
...
We calculate that the transmit queue start stall should occur before
7095s according to watchdog_timeo, the rcu start stall at 7087s.
These two times are close together, it is difficult to confirm which
happened first.
To let users know the exact time the stall started, print msecs when
the transmit queue time out.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Function tcf_exts_init_ex() sets exts->miss_cookie_node ptr only
when use_action_miss is true so it assumes in other case that
the field is set to NULL by the caller. If not then the field
contains garbage and subsequent tcf_exts_destroy() call results
in a crash.
Ensure that the field .miss_cookie_node pointer is NULL when
use_action_miss parameter is false to avoid this potential scenario.
Fixes: 80cd22c35c ("net/sched: cls_api: Support hardware miss to tc action")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230420183634.1139391-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/377
Fixes: afe4fd0624 ("pkt_sched: fq: Fair Queue packet scheduler")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7b3a3c7e36d03068707a021760a194a8eb5ad41a.1682002300.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
SCTP is not universally deployed, allow hiding its bit
from the skb.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Palash reports a UAF when using a modified version of syzkaller[1].
When 'tcf_exts_miss_cookie_base_alloc()' fails in 'tcf_exts_init_ex()'
a call to 'tcf_exts_destroy()' is made to free up the tcf_exts
resources.
In flower, a call to '__fl_put()' when 'tcf_exts_init_ex()' fails is made;
Then calling 'tcf_exts_destroy()', which triggers an UAF since the
already freed tcf_exts action pointer is lingering in the struct.
Before the offending patch, this was not an issue since there was no
case where the tcf_exts action pointer could linger. Therefore, restore
the old semantic by clearing the action pointer in case of a failure to
initialize the miss_cookie.
[1] https://github.com/cmu-pasta/linux-kernel-enriched-corpus
v1->v2: Fix compilation on configs without tc actions (kernel test robot)
Fixes: 80cd22c35c ("net/sched: cls_api: Support hardware miss to tc action")
Reported-by: Palash Oswal <oswalpalash@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the TCA_QFQ_LMAX value is not offered through nlattr, lmax is determined by the MTU value of the network device.
The MTU of the loopback device can be set up to 2^31-1.
As a result, it is possible to have an lmax value that exceeds QFQ_MIN_LMAX.
Due to the invalid lmax value, an index is generated that exceeds the QFQ_MAX_INDEX(=24) value, causing out-of-bounds read/write errors.
The following reports a oob access:
[ 84.582666] BUG: KASAN: slab-out-of-bounds in qfq_activate_agg.constprop.0 (net/sched/sch_qfq.c:1027 net/sched/sch_qfq.c:1060 net/sched/sch_qfq.c:1313)
[ 84.583267] Read of size 4 at addr ffff88810f676948 by task ping/301
[ 84.583686]
[ 84.583797] CPU: 3 PID: 301 Comm: ping Not tainted 6.3.0-rc5 #1
[ 84.584164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[ 84.584644] Call Trace:
[ 84.584787] <TASK>
[ 84.584906] dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
[ 84.585108] print_report (mm/kasan/report.c:320 mm/kasan/report.c:430)
[ 84.585570] kasan_report (mm/kasan/report.c:538)
[ 84.585988] qfq_activate_agg.constprop.0 (net/sched/sch_qfq.c:1027 net/sched/sch_qfq.c:1060 net/sched/sch_qfq.c:1313)
[ 84.586599] qfq_enqueue (net/sched/sch_qfq.c:1255)
[ 84.587607] dev_qdisc_enqueue (net/core/dev.c:3776)
[ 84.587749] __dev_queue_xmit (./include/net/sch_generic.h:186 net/core/dev.c:3865 net/core/dev.c:4212)
[ 84.588763] ip_finish_output2 (./include/net/neighbour.h:546 net/ipv4/ip_output.c:228)
[ 84.589460] ip_output (net/ipv4/ip_output.c:430)
[ 84.590132] ip_push_pending_frames (./include/net/dst.h:444 net/ipv4/ip_output.c:126 net/ipv4/ip_output.c:1586 net/ipv4/ip_output.c:1606)
[ 84.590285] raw_sendmsg (net/ipv4/raw.c:649)
[ 84.591960] sock_sendmsg (net/socket.c:724 net/socket.c:747)
[ 84.592084] __sys_sendto (net/socket.c:2142)
[ 84.593306] __x64_sys_sendto (net/socket.c:2150)
[ 84.593779] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[ 84.593902] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
[ 84.594070] RIP: 0033:0x7fe568032066
[ 84.594192] Code: 0e 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c09[ 84.594796] RSP: 002b:00007ffce388b4e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
Code starting with the faulting instruction
===========================================
[ 84.595047] RAX: ffffffffffffffda RBX: 00007ffce388cc70 RCX: 00007fe568032066
[ 84.595281] RDX: 0000000000000040 RSI: 00005605fdad6d10 RDI: 0000000000000003
[ 84.595515] RBP: 00005605fdad6d10 R08: 00007ffce388eeec R09: 0000000000000010
[ 84.595749] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040
[ 84.595984] R13: 00007ffce388cc30 R14: 00007ffce388b4f0 R15: 0000001d00000001
[ 84.596218] </TASK>
[ 84.596295]
[ 84.596351] Allocated by task 291:
[ 84.596467] kasan_save_stack (mm/kasan/common.c:46)
[ 84.596597] kasan_set_track (mm/kasan/common.c:52)
[ 84.596725] __kasan_kmalloc (mm/kasan/common.c:384)
[ 84.596852] __kmalloc_node (./include/linux/kasan.h:196 mm/slab_common.c:967 mm/slab_common.c:974)
[ 84.596979] qdisc_alloc (./include/linux/slab.h:610 ./include/linux/slab.h:731 net/sched/sch_generic.c:938)
[ 84.597100] qdisc_create (net/sched/sch_api.c:1244)
[ 84.597222] tc_modify_qdisc (net/sched/sch_api.c:1680)
[ 84.597357] rtnetlink_rcv_msg (net/core/rtnetlink.c:6174)
[ 84.597495] netlink_rcv_skb (net/netlink/af_netlink.c:2574)
[ 84.597627] netlink_unicast (net/netlink/af_netlink.c:1340 net/netlink/af_netlink.c:1365)
[ 84.597759] netlink_sendmsg (net/netlink/af_netlink.c:1942)
[ 84.597891] sock_sendmsg (net/socket.c:724 net/socket.c:747)
[ 84.598016] ____sys_sendmsg (net/socket.c:2501)
[ 84.598147] ___sys_sendmsg (net/socket.c:2557)
[ 84.598275] __sys_sendmsg (./include/linux/file.h:31 net/socket.c:2586)
[ 84.598399] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[ 84.598520] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
[ 84.598688]
[ 84.598744] The buggy address belongs to the object at ffff88810f674000
[ 84.598744] which belongs to the cache kmalloc-8k of size 8192
[ 84.599135] The buggy address is located 2664 bytes to the right of
[ 84.599135] allocated 7904-byte region [ffff88810f674000, ffff88810f675ee0)
[ 84.599544]
[ 84.599598] The buggy address belongs to the physical page:
[ 84.599777] page:00000000e638567f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f670
[ 84.600074] head:00000000e638567f order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 84.600330] flags: 0x200000000010200(slab|head|node=0|zone=2)
[ 84.600517] raw: 0200000000010200 ffff888100043180 dead000000000122 0000000000000000
[ 84.600764] raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
[ 84.601009] page dumped because: kasan: bad access detected
[ 84.601187]
[ 84.601241] Memory state around the buggy address:
[ 84.601396] ffff88810f676800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 84.601620] ffff88810f676880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 84.601845] >ffff88810f676900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 84.602069] ^
[ 84.602243] ffff88810f676980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 84.602468] ffff88810f676a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 84.602693] ==================================================================
[ 84.602924] Disabling lock debugging due to kernel taint
Fixes: 3015f3d2a3 ("pkt_sched: enable QFQ to support TSO/GSO")
Reported-by: Gwangun Jung <exsociety@gmail.com>
Signed-off-by: Gwangun Jung <exsociety@gmail.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a duplication of the FP adminStatus logic introduced for
tc-mqprio. Offloading is done through the tc_mqprio_qopt_offload
structure embedded within tc_taprio_qopt_offload. So practically, if a
device driver is written to treat the mqprio portion of taprio just like
standalone mqprio, it gets unified handling of frame preemption.
I would have reused more code with taprio, but this is mostly netlink
attribute parsing, which is hard to transform into generic code without
having something that stinks as a result. We have the same variables
with the same semantics, just different nlattr type values
(TCA_MQPRIO_TC_ENTRY=5 vs TCA_TAPRIO_ATTR_TC_ENTRY=12;
TCA_MQPRIO_TC_ENTRY_FP=2 vs TCA_TAPRIO_TC_ENTRY_FP=3, etc) and
consequently, different policies for the nest.
Every time nla_parse_nested() is called, an on-stack table "tb" of
nlattr pointers is allocated statically, up to the maximum understood
nlattr type. That array size is hardcoded as a constant, but when
transforming this into a common parsing function, it would become either
a VLA (which the Linux kernel rightfully doesn't like) or a call to the
allocator.
Having FP adminStatus in tc-taprio can be seen as addressing the 802.1Q
Annex S.3 "Scheduling and preemption used in combination, no HOLD/RELEASE"
and S.4 "Scheduling and preemption used in combination with HOLD/RELEASE"
use cases. HOLD and RELEASE events are emitted towards the underlying
MAC Merge layer when the schedule hits a Set-And-Hold-MAC or a
Set-And-Release-MAC gate operation. So within the tc-taprio UAPI space,
one can distinguish between the 2 use cases by choosing whether to use
the TC_TAPRIO_CMD_SET_AND_HOLD and TC_TAPRIO_CMD_SET_AND_RELEASE gate
operations within the schedule, or just TC_TAPRIO_CMD_SET_GATES.
A small part of the change is dedicated to refactoring the max_sdu
nlattr parsing to put all logic under the "if" that tests for presence
of that nlattr.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IEEE 802.1Q-2018 clause 6.7.2 Frame preemption specifies that each
packet priority can be assigned to a "frame preemption status" value of
either "express" or "preemptible". Express priorities are transmitted by
the local device through the eMAC, and preemptible priorities through
the pMAC (the concepts of eMAC and pMAC come from the 802.3 MAC Merge
layer).
The FP adminStatus is defined per packet priority, but 802.1Q clause
12.30.1.1.1 framePreemptionAdminStatus also says that:
| Priorities that all map to the same traffic class should be
| constrained to use the same value of preemption status.
It is impossible to ignore the cognitive dissonance in the standard
here, because it practically means that the FP adminStatus only takes
distinct values per traffic class, even though it is defined per
priority.
I can see no valid use case which is prevented by having the kernel take
the FP adminStatus as input per traffic class (what we do here).
In addition, this also enforces the above constraint by construction.
User space network managers which wish to expose FP adminStatus per
priority are free to do so; they must only observe the prio_tc_map of
the netdev (which presumably is also under their control, when
constructing the mqprio netlink attributes).
The reason for configuring frame preemption as a property of the Qdisc
layer is that the information about "preemptible TCs" is closest to the
place which handles the num_tc and prio_tc_map of the netdev. If the
UAPI would have been any other layer, it would be unclear what to do
with the FP information when num_tc collapses to 0. A key assumption is
that only mqprio/taprio change the num_tc and prio_tc_map of the netdev.
Not sure if that's a great assumption to make.
Having FP in tc-mqprio can be seen as an implementation of the use case
defined in 802.1Q Annex S.2 "Preemption used in isolation". There will
be a separate implementation of FP in tc-taprio, for the other use
cases.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
