1) Imports ENCAP_MPLS labels from IPv4/IPv6 routes.
Note that this requires libnl 3.6.0 or newer.
In previous patches, the fib_path_ext_t had a path ID of -1.
After a long investigation, it turned out to be caused by route weight
being set to 0. There is a comment explaining more details.
2) Handles MPLS routes.
MPLS routes were wrongly added as IPv4 routes before.
POP and SWAP are now both supported.
All the routes are installed as NON-EOS and EOS routes,
as the Linux kernel does not differentiate.
EOS POP used in PHP uses the next-hop address family
to determine the resulting address family.
This patch is sufficient for P setups.
PE setups with implicit null should also function okay, as long as a
seperate label gets programmed per address family.
PE setups with explicit null will also forward packets,
but punting is a bit odd and needs MPLS input enabled on the LCP host
device.
Make sure to enable MPLS in VPP first.
3) Propagate MPLS input state to LCP Pair and Linux.
Since the Linux kernel uses the MPLS routes itself,
the LCP pair tap needs MPLS enabled to allow host originated packets.
This also syncs the Linux `net.mpls.conf.<host_if>.input` sysctl to
allow punted packets to have MPLS labels, mostly explicit nulls.
For that to work, load the mpls kernel modules.
4) Cross connect MPLS packets from Linux directly to interface-output
This is a port of https://gerrit.fd.io/r/c/vpp/+/38702
Add lcpng_nl_sync.c that will house these functions. Their purpose is to
take state learned from netlink messages, and apply that state to VPP.
Some rearranging/plumbing was necessary to get logging to be visible in
this new source file.
Then, we add lcp_nl_neigh_add() and _del() which look up the LIP, convert
the lladdr and ip address from Netlink into VPP variants, and then add or
remove the ip4/ip6 neighbor adjacency.
Register lcp_nl_init() which adds interface pair add/del callbacks.
lcb_nl_pair_add_cb: Initiate netlink listener for first interface in its
netns. If subsequent adds are in other netns, issue a warning. Keep
refcount.
lcb_nl_pair_del_cb: Remove listener when the last interface pair is
removed.
Socket is opened, file is added to VPP's epoll, with lcp_nl_read_cb()
and lcp_nl_error_cb() callbacks installed.
- lcp_nl_read_cb() calls lcp_nl_callback() which pushes netlink messages
onto a queue and issues NL_EVENT_READ event, any socket read error
issues NL_EVENT_READ_ERR event.
- lcp_nl_error_cb() simply issues NL_EVENT_READ_ERR event.
Then, initialize a process node called lcp_nl_process(), which handles:
- NL_EVENT_READ and call lcp_nl_process_msgs()
- if messages are left in the queue, reschedule consumption after M
msecs. This allows new netlink messages to continuously be read from
the kernel, even if we have lots of messages to consume.
- NL_EVENT_READ_ERR and close/reopens the netlink socket.
lcp_nl_process_msgs() processes up to N messages and/or for up to M
msecs, whichever comes first. For each, calling lcp_nl_dispatch().
lcp_nl_dispatch() ultimately just throws the message away after
logging it with format_nl_object()
There are three ways in which IP addresses will want to be copied
from VPP into the companion Linux devices:
1) set interface ip address ... adds an IPv4 or IPv6 address
- this is handled by lcp_itf_ip[46]_add_del_interface_addr() which
is a callback installed in lcp_itf_pair_init()
2) set interface ip address del ... removes them
- also handled by lcp_itf_ip[46]_add_del_interface_addr() but
curiously there is no upstream vnet_netlink_del_ip[46]_addr() so
I wrote them inline here - I will try to get them upstreamed, as
they appear to be obvious companions in vnet/device/netlink.h
3) Upon LIP creation, it could be that there are L3 addresses already
on the VPP interface. If so, set them with lcp_itf_set_interface_addr()
This means that now, at any time a new LIP is created, its state from
VPP is fully copied over (MTU, Link state, IPv4/IPv6 addresses)!
At runtime, new addresses can be set/removed as well.
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.
