gnb_udp_over_tcp

gnb_udp_over_tcp

GNB is an open source, decentralized VPN that performs three-layer network switching through P2P with ultimate intranet penetration capabilities.

Data is transmitted between GNB nodes through the UDP protocol. In some network environments, routers/firewalls will implement QOS policies for UDP packets. Therefore, forwarding GNB data through tcp links does not require changes to the GNB communication protocol and can improve the adaptability of the GNB network. way.

gnb_udp_over_tcp is a service developed for GNB that forwards UDP packets through tcp links.

Relay GNB data via gnb_udp_over_tcp

Demo environment

The remote GNB node ip address is 192.168.1.25 GNB UDP port 9025 GNB TUN ip 10.1.0.25 The remote GNB configuration file does not need to be adjusted

The relay server IP address is 192.168.1.11

 [gnb_1010]
    |
   udp 
    |
[udp_over_tcp udp:127.0.0.1:5001]    (./gnb_udp_over_tcp -u -l 5001 192.168.1.11 6000)
    |
   tcp
    |
[udp_over_tcp tcp:192.168.1.11:6000] (./gnb_udp_over_tcp -t -l 6000 192.168.1.25 9025)
    |
   udp 
    |
[gnb_1025  udp:192.168.1.25:9025]

Executed on 192.168.1.11

./gnb_udp_over_tcp -t -l 6000 192.168.1.25 9025

The local ip address is 192.168.1.10 GNB TUN ip 10.1.0.10

The content of local GNB conf/1010/address.conf is

 n|1025|127.0.0.1|5001

Do not configure i type GNB nodes in address.conf

Executed on 192.168.1.10

./gnb_udp_over_tcp -u -l 5001 192.168.1.11 6000

Start the local GNB node and ping 10.1.0.25 to check whether the ping can succeed.

gnb_udp_over_tcp can transfer data for other services based on UDP protocol

Use nc for local test demonstration

 [netcat]                          (nc -u 127.0.0.1 5001)
    |
   udp
    |
[udp_over_tcp udp:127.0.0.1:5001] (./gnb_udp_over_tcp -u -l 5001 127.0.0.1 6000)
    |
   tcp
    |
[udp_over_tcp tcp:127.0.0.1:6000] (./gnb_udp_over_tcp -t -l 6000 127.0.0.1 7000)
    |
   udp
    |
[netcat udp:127.0.0.1:7000]       (nc -u -l 7000)

Step1

Use nc to monitor port 7000 udp

nc -u -l 7000

Step2

Start the tcp side of gnb_udp_over_tcp: listen to the tcp 6000 port. Each tcp link connected to the port will establish a udp socket to form a channel. The packets received by the tcp link are sent to the UDP 7000 port of 127.0.0.1, from The data received at the udp end will be sent to the other end of the tcp link. The tcp end of gnb_udp_over_tcp can simultaneously access multiple tcp connections and forward them to the udp port of the same destination address.

./gnb_udp_over_tcp -t -l 6000 127.0.0.1 7000

Step3

Start the udp end of gnb_udp_over_tcp: listen to udp port 5001, establish a tcp link with 127.0.0.1 tcp port 6000, the data received by the udp end is sent to the other end of the tcp link, and the data received from the tcp link is sent to the udp end .

./gnb_udp_over_tcp -u -l 5001 127.0.0.1 6000

Step4

Use nc to access the 5001 udp port of 127.0.0.1 to check whether the data is successfully forwarded.

nc -u 127.0.0.1 5001

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