| .. SPDX-License-Identifier: GPL-2.0 |
| |
| ======================================== |
| Bare UDP Tunnelling Module Documentation |
| ======================================== |
| |
| There are various L3 encapsulation standards using UDP being discussed to |
| leverage the UDP based load balancing capability of different networks. |
| MPLSoUDP (__ https://tools.ietf.org/html/rfc7510) is one among them. |
| |
| The Bareudp tunnel module provides a generic L3 encapsulation tunnelling |
| support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside |
| a UDP tunnel. |
| |
| Special Handling |
| ---------------- |
| The bareudp device supports special handling for MPLS & IP as they can have |
| multiple ethertypes. |
| MPLS procotcol can have ethertypes ETH_P_MPLS_UC (unicast) & ETH_P_MPLS_MC (multicast). |
| IP protocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6). |
| This special handling can be enabled only for ethertypes ETH_P_IP & ETH_P_MPLS_UC |
| with a flag called multiproto mode. |
| |
| Usage |
| ------ |
| |
| 1) Device creation & deletion |
| |
| a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype 0x8847. |
| |
| This creates a bareudp tunnel device which tunnels L3 traffic with ethertype |
| 0x8847 (MPLS traffic). The destination port of the UDP header will be set to |
| 6635.The device will listen on UDP port 6635 to receive traffic. |
| |
| b) ip link delete bareudp0 |
| |
| 2) Device creation with multiple proto mode enabled |
| |
| There are two ways to create a bareudp device for MPLS & IP with multiproto mode |
| enabled. |
| |
| a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype 0x8847 multiproto |
| |
| b) ip link add dev bareudp0 type bareudp dstport 6635 ethertype mpls |
| |
| 3) Device Usage |
| |
| The bareudp device could be used along with OVS or flower filter in TC. |
| The OVS or TC flower layer must set the tunnel information in SKB dst field before |
| sending packet buffer to the bareudp device for transmission. On reception the |
| bareudp device extracts and stores the tunnel information in SKB dst field before |
| passing the packet buffer to the network stack. |
