On Fri, Sep 21, 2018 at 02:30:05PM -0700, Saif Hasan wrote:
> Summary:
>
> This appears to be necessary and sufficient change to enable `MPLS` on
> `ip6gre` tunnels (RFC4023).
>
> This diff allows IP6GRE devices to be recognized by MPLS kernel module
> and hence user can configure interface to accept packets with mpls
> headers as well setup mpls routes on them.
>
> Test Plan:
>
> Test plan consists of multiple containers connected via GRE-V6 tunnel.
> Then carrying out testing steps as below.
>
> - Carry out necessary sysctl settings on all containers
>
> ```
> sysctl -w net.mpls.platform_labels=65536
> sysctl -w net.mpls.ip_ttl_propagate=1
> sysctl -w net.mpls.conf.lo.input=1
> ```
>
> - Establish IP6GRE tunnels
>
> ```
> ip -6 tunnel add name if_1_2_1 mode ip6gre \
> local 2401:db00:21:6048:feed:0::1 \
> remote 2401:db00:21:6048:feed:0::2 key 1
> ip link set dev if_1_2_1 up
> sysctl -w net.mpls.conf.if_1_2_1.input=1
> ip -4 addr add 169.254.0.2/31 dev if_1_2_1 scope link
>
> ip -6 tunnel add name if_1_3_1 mode ip6gre \
> local 2401:db00:21:6048:feed:0::1 \
> remote 2401:db00:21:6048:feed:0::3 key 1
> ip link set dev if_1_3_1 up
> sysctl -w net.mpls.conf.if_1_3_1.input=1
> ip -4 addr add 169.254.0.4/31 dev if_1_3_1 scope link
> ```
>
> - Install MPLS encap rules on node-1 towards node-2
>
> ```
> ip route add 192.168.0.11/32 nexthop encap mpls 32/64 \
> via inet 169.254.0.3 dev if_1_2_1
> ```
>
> - Install MPLS forwarding rules on node-2 and node-3
> ```
> // node2
> ip -f mpls route add 32 via inet 169.254.0.7 dev if_2_4_1
>
> // node3
> ip -f mpls route add 64 via inet 169.254.0.12 dev if_4_3_1
> ```
>
> - Ping 192.168.0.11 (node4) from 192.168.0.1 (node1) (where routing
> towards 192.168.0.1 is via IP route directly towards node1 from node4)
> ```
> ping 192.168.0.11
> ```
>
> - tcpdump on interface to capture ping packets wrapped within MPLS
> header which inturn wrapped within IP6GRE header
>
> ```
> 16:43:41.121073 IP6
> 2401:db00:21:6048:feed::1 > 2401:db00:21:6048:feed::2:
> DSTOPT GREv0, key=0x1, length 100:
> MPLS (label 32, exp 0, ttl 255) (label 64, exp 0, [S], ttl 255)
> IP 192.168.0.1 > 192.168.0.11:
> ICMP echo request, id 1208, seq 45, length 64
>
> 0x0000: 6000 2cdb 006c 3c3f 2401 db00 0021 6048 `.,..l<?$....!`H
> 0x0010: feed 0000 0000 0001 2401 db00 0021 6048 ........$....!`H
> 0x0020: feed 0000 0000 0002 2f00 0401 0401 0100 ......../.......
> 0x0030: 2000 8847 0000 0001 0002 00ff 0004 01ff ...G............
> 0x0040: 4500 0054 3280 4000 ff01 c7cb c0a8 0001 E..T2.@.........
> 0x0050: c0a8 000b 0800 a8d7 04b8 002d 2d3c a05b ...........--<.[
> 0x0060: 0000 0000 bcd8 0100 0000 0000 1011 1213 ................
> 0x0070: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 .............!"#
> 0x0080: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 $%&'()*+,-./0123
> 0x0090: 3435 3637 4567
> ```
>
> Signed-off-by: Saif Hasan <h...@fb.com>
This appears to be consistent with work I did to enable
MPLS over SIT, IPIP and (IPv4) IPGRE.
I do not recall why I did not enable IP6GRE at the time,
it may well have been a oversight.
Reviewed-by: Simon Horman <simon.hor...@netronome.com>
> ---
> net/mpls/af_mpls.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
> index 7a4de6d618b1..8fbe6cdbe255 100644
> --- a/net/mpls/af_mpls.c
> +++ b/net/mpls/af_mpls.c
> @@ -1533,10 +1533,14 @@ static int mpls_dev_notify(struct notifier_block
> *this, unsigned long event,
> unsigned int flags;
>
> if (event == NETDEV_REGISTER) {
> - /* For now just support Ethernet, IPGRE, SIT and IPIP devices */
> +
> + /* For now just support Ethernet, IPGRE, IP6GRE, SIT and
> + * IPIP devices
> + */
> if (dev->type == ARPHRD_ETHER ||
> dev->type == ARPHRD_LOOPBACK ||
> dev->type == ARPHRD_IPGRE ||
> + dev->type == ARPHRD_IP6GRE ||
> dev->type == ARPHRD_SIT ||
> dev->type == ARPHRD_TUNNEL) {
> mdev = mpls_add_dev(dev);
> --
> 2.13.5
>
