Re: [PATCH net-next 4/4] net/sched: act_mirred: Implement ingress actions

On Fri, Sep 23, 2016 at 8:40 AM, Shmulik Ladkani
[off-list ref] wrote:

On Fri, 23 Sep 2016 08:48:33 -0400 Jamal Hadi Salim [off-list ref] wrote:

quoted

quoted

Even today, one may create loops using existing 'egress redirect',
e.g. this rediculously errorneous construct:

 # ip l add v0 type veth peer name v0p
 # tc filter add dev v0p parent ffff: basic \
    action mirred egress redirect dev v0

I think we actually recover from this one by eventually
dropping (theres a ttl field).

[off topic]

Don't know about that :) cpu fan got very noisy, 3 of 4 cores at 100%,
and after one second I got:

# ip -s l show type veth
16: v0p@v0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether a2:64:ff:10:dd:85 brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast
    71660305923 469890864 0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    3509       24       0       0       0       0
17: v0@v0p: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 52:a2:34:f6:7c:ec brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast
    3509       24       0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    71660713017 469893555 0       0       0       0

These ghost packets never enter IP stack, I don't think TTL
helps.