commit 91f60564228f4546cbe1c2bee3c760a651d8fae0
author Ravi Teja <raviteja28031990@gmail.com> Wed Apr 17 06:26:43 2024 -0500
committer Ravi Teja <raviteja28031990@gmail.com> Mon Apr 22 03:27:41 2024 +0000
tree fe62c7a87198c9fc578508c275d3ed5c908c641c
parent c3c6b4c3c6daef74e087c6f3e01c1482bec9abe4

IPv4/IPv6 Gateway: Configure GatewayOnLink

Currently when both interfaces configured static ip addresses and one of
that static ip address is in private network then while reload network
configuration further, route order keep changes and interface with
private network is not reachable when other gateway route is on the top
of routing table.

This commit configures IPv4/IPv6 static gateway using systemd-networkd's
Route option and sets GatewayOnLink option and make sure interfaces
network reachable irrespective of route order while reloading networkd.

Tested By:
configure one interface in static and other interface DHCP.
configure both interfaces with static IP and one interface on private
network.

Sample IPv4 network route added in systemd-networkd configuration file
[Route]
GatewayOnLink=true
Gateway=9.10.x.1

Change-Id: Id7c9ba74cf7e71e6105536c5affc905754cae908
Signed-off-by: Ravi Teja <raviteja28031990@gmail.com>

src/ethernet_interface.cpp

diff --git a/src/ethernet_interface.cpp b/src/ethernet_interface.cpp
index 1467240..cd06003 100644
--- a/src/ethernet_interface.cpp
+++ b/src/ethernet_interface.cpp
@@ -759,13 +759,14 @@
             }
         }
         {
-            auto& gateways = network["Gateway"];
             if (!dhcp4())
             {
-                auto gateway = EthernetInterfaceIntf::defaultGateway();
-                if (!gateway.empty())
+                auto gateway4 = EthernetInterfaceIntf::defaultGateway();
+                if (!gateway4.empty())
                 {
-                    gateways.emplace_back(gateway);
+                    auto& gateway4route = config.map["Route"].emplace_back();
+                    gateway4route["Gateway"].emplace_back(gateway4);
+                    gateway4route["GatewayOnLink"].emplace_back("true");
                 }
             }
 
@@ -774,7 +775,9 @@
                 auto gateway6 = EthernetInterfaceIntf::defaultGateway6();
                 if (!gateway6.empty())
                 {
-                    gateways.emplace_back(gateway6);
+                    auto& gateway6route = config.map["Route"].emplace_back();
+                    gateway6route["Gateway"].emplace_back(gateway6);
+                    gateway6route["GatewayOnLink"].emplace_back("true");
                 }
             }
         }