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  1. 19 8月, 2017 1 次提交
  3. 10 8月, 2017 1 次提交
  5. 09 8月, 2017 1 次提交
  7. 08 8月, 2017 2 次提交
  9. 05 8月, 2017 3 次提交
  11. 26 5月, 2017 2 次提交
  13. 23 5月, 2017 2 次提交
  15. 18 5月, 2017 10 次提交
  17. 22 4月, 2017 1 次提交
    • W
      net_sched: move the empty tp check from ->destroy() to ->delete() · 763dbf63
      由 WANG Cong 提交于 
      We could have a race condition where in ->classify() path we
dereference tp->root and meanwhile a parallel ->destroy() makes it
a NULL. Daniel cured this bug in commit d9363774
("net, sched: respect rcu grace period on cls destruction").

This happens when ->destroy() is called for deleting a filter to
check if we are the last one in tp, this tp is still linked and
visible at that time. The root cause of this problem is the semantic
of ->destroy(), it does two things (for non-force case):

1) check if tp is empty
2) if tp is empty we could really destroy it

and its caller, if cares, needs to check its return value to see if it
is really destroyed. Therefore we can't unlink tp unless we know it is
empty.

As suggested by Daniel, we could actually move the test logic to ->delete()
so that we can safely unlink tp after ->delete() tells us the last one is
just deleted and before ->destroy().

Fixes: 1e052be6 ("net_sched: destroy proto tp when all filters are gone")
Cc: Roi Dayan <roid@mellanox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      763dbf63
  19. 18 4月, 2017 1 次提交
  21. 14 4月, 2017 1 次提交
  23. 15 2月, 2017 1 次提交
  25. 11 2月, 2017 6 次提交
  27. 27 12月, 2016 1 次提交
    • D
      net, sched: fix soft lockup in tc_classify · 628185cf
      由 Daniel Borkmann 提交于 
      Shahar reported a soft lockup in tc_classify(), where we run into an
endless loop when walking the classifier chain due to tp->next == tp
which is a state we should never run into. The issue only seems to
trigger under load in the tc control path.

What happens is that in tc_ctl_tfilter(), thread A allocates a new
tp, initializes it, sets tp_created to 1, and calls into tp->ops->change()
with it. In that classifier callback we had to unlock/lock the rtnl
mutex and returned with -EAGAIN. One reason why we need to drop there
is, for example, that we need to request an action module to be loaded.

This happens via tcf_exts_validate() -> tcf_action_init/_1() meaning
after we loaded and found the requested action, we need to redo the
whole request so we don't race against others. While we had to unlock
rtnl in that time, thread B's request was processed next on that CPU.
Thread B added a new tp instance successfully to the classifier chain.
When thread A returned grabbing the rtnl mutex again, propagating -EAGAIN
and destroying its tp instance which never got linked, we goto replay
and redo A's request.

This time when walking the classifier chain in tc_ctl_tfilter() for
checking for existing tp instances we had a priority match and found
the tp instance that was created and linked by thread B. Now calling
again into tp->ops->change() with that tp was successful and returned
without error.

tp_created was never cleared in the second round, thus kernel thinks
that we need to link it into the classifier chain (once again). tp and
*back point to the same object due to the match we had earlier on. Thus
for thread B's already public tp, we reset tp->next to tp itself and
link it into the chain, which eventually causes the mentioned endless
loop in tc_classify() once a packet hits the data path.

Fix is to clear tp_created at the beginning of each request, also when
we replay it. On the paths that can cause -EAGAIN we already destroy
the original tp instance we had and on replay we really need to start
from scratch. It seems that this issue was first introduced in commit
12186be7 ("net_cls: fix unconfigured struct tcf_proto keeps chaining
and avoid kernel panic when we use cls_cgroup").

Fixes: 12186be7 ("net_cls: fix unconfigured struct tcf_proto keeps chaining and avoid kernel panic when we use cls_cgroup")
Reported-by: NShahar Klein <shahark@mellanox.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Tested-by: NShahar Klein <shahark@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      628185cf
  29. 03 12月, 2016 1 次提交
    • H
      net/sched: cls_flower: Add offload support using egress Hardware device · 7091d8c7
      由 Hadar Hen Zion 提交于 
      In order to support hardware offloading when the device given by the tc
rule is different from the Hardware underline device, extract the mirred
(egress) device from the tc action when a filter is added, using the new
tc_action_ops, get_dev().

Flower caches the information about the mirred device and use it for
calling ndo_setup_tc in filter change, update stats and delete.

Calling ndo_setup_tc of the mirred (egress) device instead of the
ingress device will allow a resolution between the software ingress
device and the underline hardware device.

The resolution will take place inside the offloading driver using
'egress_device' flag added to tc_to_netdev struct which is provided to
the offloading driver.
Signed-off-by: NHadar Hen Zion <hadarh@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7091d8c7
  31. 25 11月, 2016 1 次提交
  33. 18 11月, 2016 1 次提交
  35. 28 10月, 2016 1 次提交
    • J
      net sched filters: fix notification of filter delete with proper handle · 9ee78374
      由 Jamal Hadi Salim 提交于 
      Daniel says:

While trying out [1][2], I noticed that tc monitor doesn't show the
correct handle on delete:

$ tc monitor
qdisc clsact ffff: dev eno1 parent ffff:fff1
filter dev eno1 ingress protocol all pref 49152 bpf handle 0x2a [...]
deleted filter dev eno1 ingress protocol all pref 49152 bpf handle 0xf3be0c80

some context to explain the above:
The user identity of any tc filter is represented by a 32-bit
identifier encoded in tcm->tcm_handle. Example 0x2a in the bpf filter
above. A user wishing to delete, get or even modify a specific filter
uses this handle to reference it.
Every classifier is free to provide its own semantics for the 32 bit handle.
Example: classifiers like u32 use schemes like 800:1:801 to describe
the semantics of their filters represented as hash table, bucket and
node ids etc.
Classifiers also have internal per-filter representation which is different
from this externally visible identity. Most classifiers set this
internal representation to be a pointer address (which allows fast retrieval
of said filters in their implementations). This internal representation
is referenced with the "fh" variable in the kernel control code.

When a user successfuly deletes a specific filter, by specifying the correct
tcm->tcm_handle, an event is generated to user space which indicates
which specific filter was deleted.

Before this patch, the "fh" value was sent to user space as the identity.
As an example what is shown in the sample bpf filter delete event above
is 0xf3be0c80. This is infact a 32-bit truncation of 0xffff8807f3be0c80
which happens to be a 64-bit memory address of the internal filter
representation (address of the corresponding filter's struct cls_bpf_prog);

After this patch the appropriate user identifiable handle as encoded
in the originating request tcm->tcm_handle is generated in the event.
One of the cardinal rules of netlink rules is to be able to take an
event (such as a delete in this case) and reflect it back to the
kernel and successfully delete the filter. This patch achieves that.

Note, this issue has existed since the original TC action
infrastructure code patch back in 2004 as found in:
https://git.kernel.org/cgit/linux/kernel/git/history/history.git/commit/

[1] http://patchwork.ozlabs.org/patch/682828/
[2] http://patchwork.ozlabs.org/patch/682829/

Fixes: 4e54c4816bfe ("[NET]: Add tc extensions infrastructure.")
Reported-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9ee78374
  37. 13 10月, 2016 1 次提交
    • E
      net_sched: do not broadcast RTM_GETTFILTER result · fa59b27c
      由 Eric Dumazet 提交于 
      There are two ways to get tc filters from kernel to user space.

1) Full dump (tc_dump_tfilter())
2) RTM_GETTFILTER to get one precise filter, reducing overhead.

The second operation is unfortunately broadcasting its result,
polluting "tc monitor" users.

This patch makes sure only the requester gets the result, using
netlink_unicast() instead of rtnetlink_send()

Jamal cooked an iproute2 patch to implement "tc filter get" operation,
but other user space libraries already use RTM_GETTFILTER when a single
filter is queried, instead of dumping all filters.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fa59b27c
  39. 20 9月, 2016 1 次提交
  41. 18 8月, 2016 1 次提交