This is a straight foward copy of the VPP L3 (packet) MTU into the Linux
host interface, for any change on an interface/sub-int for which a LIP is
defined.
As with Linux itself, no care is taken to ensure that the parent interface
(e0) has a higher MTU than the child interface (e0.10).
DBGvpp# create sub TenGigabitEthernet3/0/0 10
DBGvpp# lcp create TenGigabitEthernet3/0/0 host-if e0
DBGvpp# lcp create TenGigabitEthernet3/0/0.10 host-if e0.10
602: e0: <BROADCAST,MULTICAST> mtu 9000 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set interface mtu packet 9216 TenGigabitEthernet3/0/0
602: e0: <BROADCAST,MULTICAST> mtu 9216 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set interface mtu packet 9050 TenGigabitEthernet3/0/0
602: e0: <BROADCAST,MULTICAST> mtu 9050 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set interface mtu packet 9050 TenGigabitEthernet3/0/0.10
602: e0: <BROADCAST,MULTICAST> mtu 9050 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9050 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set interface mtu packet 1500 TenGigabitEthernet3/0/0.10
602: e0: <BROADCAST,MULTICAST> mtu 9050 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set interface mtu packet 1500 TenGigabitEthernet3/0/0
602: e0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
603: e0.10@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
When Linux changes link on a master interface, all of its children also change.
This is not true in VPP, where bringing down a phy while its sub-ints are up
will not change link on the sub-ints.
We are forced to undo that change by walking the sub-interfaces of a phy and
syncing their state back into linux.
For simplicity, just walk all interfaces, as others will be a no-op.
The approach may have to be revisited once netlink messages are
consumed, to ensure there is not an oscillation where netlink sets a
link, which forces all links to be reset, generating more netlink
messages, etc. Care should be taken when netlink consumption comes into
play!
DBGvpp# create sub TenGigabitEthernet3/0/0 1
DBGvpp# lcp create TenGigabitEthernet3/0/0 host-if e0
DBGvpp# lcp create TenGigabitEthernet3/0/0.1 host-if e0.1
593: e0: <BROADCAST,MULTICAST> mtu 9000 qdisc mq state DOWN mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noop state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set int state TenGigabitEthernet3/0/0 up
593: e0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UNKNOWN mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST> mtu 9000 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set int state TenGigabitEthernet3/0/0.1 up
593: e0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UNKNOWN mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state UP mode DEFAULT group default qlen 1000
DBGvpp# set int state TenGigabitEthernet3/0/0 down
593: e0: <BROADCAST,MULTICAST> mtu 9000 qdisc mq state DOWN mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set int state TenGigabitEthernet3/0/0 up
DBGvpp# set int state TenGigabitEthernet3/0/0.1 down
593: e0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST> mtu 9000 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
DBGvpp# set int state TenGigabitEthernet3/0/0 down
593: e0: <BROADCAST,MULTICAST> mtu 9000 qdisc mq state DOWN mode DEFAULT group default qlen 1000
594: e0.1@e0: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
This is the first in a series of functions that aims to copy forward
interface changes in the VPP dataplane into the linux interfaces.
Capture link state changes (set interface state ...) and apply them
to Linux.
There's an important dissonance here:
- When Linux sets a parent interface up, all children also go up.
ip link set enp66s0f1 down
ip link add link enp66s0f1 name foo type vlan id 1234
ip link set foo down
ip link | grep enp66s0f1
9: enp66s0f1: <BROADCAST,MULTICAST> mtu 9000 qdisc mq state DOWN mode DEFAULT group default qlen 1000
61: foo@enp66s0f1: <BROADCAST,MULTICAST,M-DOWN> mtu 9000 qdisc noop state DOWN mode DEFAULT group default qlen 1000
ip link set enp66s0f1 up
ip link | grep s0f1
9: enp66s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP mode DEFAULT group default qlen 1000
61: foo@enp66s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state UP mode DEFAULT group default qlen 1000
While in VPP this is not so, there each individual interface and
sub-interface stands for itself. I think the proper fix here is to walk
all sub-interfaces when a phy changes, and force a sync of those from
VPP to LCP as well. I'll do that in a followup commit so it's easier to
roll back.
