From 858e57e9582a37b8a1b7aa7b5ca0bf13a68e5c4b Mon Sep 17 00:00:00 2001
From: afeiszli <alex.feiszli@gmail.com>
Date: Tue, 23 Aug 2022 10:12:13 -0400
Subject: [PATCH] add explicit routing + domain for netmaker

---
 netclient/functions/daemon.go   |  4 ++++
 netclient/functions/join.go     |  6 +++++
 netclient/local/routes.go       | 39 +++++++++++++++++++++++++++++++--
 netclient/local/routes_linux.go |  5 +++++
 4 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/netclient/functions/daemon.go b/netclient/functions/daemon.go
index 1d277402..a454d9e9 100644
--- a/netclient/functions/daemon.go
+++ b/netclient/functions/daemon.go
@@ -106,6 +106,10 @@ func startGoRoutines(wg *sync.WaitGroup) context.CancelFunc {
 			// == subscribe to all nodes for each on machine ==
 			serverSet[server] = true
 			logger.Log(1, "started daemon for server ", server)
+			err := local.SetNetmakerDomainRoute(cfg.Server.API)
+			if err != nil {
+				logger.Log(0, "error setting route for netmaker: "+err.Error())
+			}
 			wg.Add(1)
 			go messageQueue(ctx, wg, &cfg)
 		}
diff --git a/netclient/functions/join.go b/netclient/functions/join.go
index ec3c2ce8..bc978ce0 100644
--- a/netclient/functions/join.go
+++ b/netclient/functions/join.go
@@ -200,6 +200,12 @@ func JoinNetwork(cfg *config.ClientConfig, privateKey string) error {
 	if err = config.SaveBackup(node.Network); err != nil {
 		logger.Log(0, "network:", node.Network, "failed to make backup, node will not auto restore if config is corrupted")
 	}
+
+	err = local.SetNetmakerDomainRoute(cfg.Server.API)
+	if err != nil {
+		logger.Log(0, "error setting route for netmaker: "+err.Error())
+	}
+
 	logger.Log(0, "starting wireguard")
 	err = wireguard.InitWireguard(&node, privateKey, nodeGET.Peers[:], false)
 	if err != nil {
diff --git a/netclient/local/routes.go b/netclient/local/routes.go
index 022d9011..f0b5aa52 100644
--- a/netclient/local/routes.go
+++ b/netclient/local/routes.go
@@ -1,7 +1,9 @@
 package local
 
 import (
+	"fmt"
 	"net"
+	"net/url"
 
 	"github.com/gravitl/netmaker/logger"
 	"github.com/gravitl/netmaker/netclient/ncutils"
@@ -42,7 +44,7 @@ func SetPeerRoutes(iface string, oldPeers map[string]bool, newPeers []wgtypes.Pe
 			if err != nil {
 				logger.Log(0, "error parsing ip:", err.Error())
 			}
-			setRoute(gwIface, &ipNet, gwIP)
+			SetExplicitRoute(gwIface, &ipNet, gwIP)
 		}
 	}
 	// traverse through all remaining existing peers
@@ -82,9 +84,10 @@ func SetCurrentPeerRoutes(iface, currentAddr string, peers []wgtypes.PeerConfig)
 			if err != nil {
 				logger.Log(0, "error parsing ip:", err.Error())
 			}
-			setRoute(gwIface, &ipNet, gwIP)
+			SetExplicitRoute(gwIface, &ipNet, gwIP)
 		}
 	}
+
 }
 
 // FlushPeerRoutes - removes all current peer routes
@@ -122,3 +125,35 @@ func SetCIDRRoute(iface, currentAddr string, cidr *net.IPNet) {
 func RemoveCIDRRoute(iface, currentAddr string, cidr *net.IPNet) {
 	removeCidr(iface, cidr, currentAddr)
 }
+
+// SetNetmakerDomainRoute - sets explicit route over Gateway for a given DNS name
+func SetNetmakerDomainRoute(domainRaw string) error {
+	var address net.IPNet
+
+	domain, err := url.Parse(domainRaw)
+	if err != nil {
+		return err
+	}
+
+	gwIP, gwIface, err := GetDefaultRoute()
+	if err != nil {
+		return fmt.Errorf("error getting default route: %w", err)
+	}
+
+	ips, err := net.LookupIP(domain.Hostname())
+	if err != nil {
+		return err
+	}
+	for _, ip := range ips {
+		if ipv4 := ip.To4(); ipv4 != nil {
+			address, err = ncutils.GetIPNetFromString(ipv4.String())
+			if err == nil {
+				break
+			}
+		}
+	}
+	if err != nil || address.IP == nil {
+		return fmt.Errorf("address not found")
+	}
+	return SetExplicitRoute(gwIface, &address, gwIP)
+}
diff --git a/netclient/local/routes_linux.go b/netclient/local/routes_linux.go
index c7decf75..7374b8ce 100644
--- a/netclient/local/routes_linux.go
+++ b/netclient/local/routes_linux.go
@@ -44,6 +44,11 @@ func setRoute(iface string, addr *net.IPNet, address string) error {
 	return err
 }
 
+func SetExplicitRoute(iface string, destination *net.IPNet, gateway string) error {
+	_, err := ncutils.RunCmd(fmt.Sprintf("ip route add %s via %s dev %s", destination.String(), gateway, iface), false)
+	return err
+}
+
 func deleteRoute(iface string, addr *net.IPNet, address string) error {
 	var err error
 	out, _ := ncutils.RunCmd(fmt.Sprintf("ip route get %s", addr.IP.String()), false)