On 2020-05-02 4:48 a.m., Jamal Hadi Salim wrote:
On 2020-04-30 11:53 p.m., Cong Wang wrote:
[..]
Steps to reproduce this:
ip li set dev dummy0 up
tc qd add dev dummy0 ingress
tc filter add dev dummy0 parent ffff: protocol arp basic action pass
tc filter show dev dummy0 root
Before this patch:
filter protocol arp pref 49152 basic
filter protocol arp pref 49152 basic handle 0x1
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
After this patch:
filter parent ffff: protocol arp pref 49152 basic
filter parent ffff: protocol arp pref 49152 basic handle 0x1
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
Note:
tc filter show dev dummy0 root
should not show that filter. OTOH,
tc filter show dev dummy0 parent ffff:
should.
root and ffff: are distinct/unique installation hooks.
Suprised no one raised this earlier - since it is so
fundamental (we should add a tdc test for it). I went back
to the oldest kernel i have from early 2018 and it was broken..
Cong, your patch is good for the case where we
want to show _all_ filters regardless of where they
were installed but only if no parent is specified. i.e if i did this:
tc filter show dev dummy0
then i am asking to see all the filters for that device.
I am actually not sure if "tc filter show dev dummy0"
ever worked that way - but it makes sense since
no dump-filtering is specified.
To illustrate, I did this:
tc filter add dev dummy0 root protocol arp prio 49151 basic action pass
And now the output looks like:
-------
# tc filter show dev dummy0 ingressfilter protocol arp pref 49151 basic
chain 0
filter protocol arp pref 49151 basic chain 0 handle 0x2
action order 1: gact action pass
random type none pass val 0
index 2 ref 1 bind 1
filter protocol arp pref 49151 basic chain 0 handle 0x1
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
# tc filter show dev dummy0 root
filter protocol arp pref 49151 basic chain 0
filter protocol arp pref 49151 basic chain 0 handle 0x2
action order 1: gact action pass
random type none pass val 0
index 2 ref 1 bind 1
filter protocol arp pref 49151 basic chain 0 handle 0x1
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
------
If, OTOH, i specified the parent
then only that parents filters should be displayed..
cheers,
jamal
