First basic version

- NFT and DNS Update skeletons
- Integrated viper configuration management
- Integrated cobra CLI management
- Basic webservice skeleton

service/nftables.go

@@ -0,0 +1,82 @@
+package service
+
+import (
+	"fmt"
+	"net"
+	"runtime"
+
+	"github.com/google/nftables"
+)
+
+func UpdateNFTSets(tableName string, set4name string, ip4 net.IP, set6name string, ip6 net.IP) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	conn := &nftables.Conn{}
+
+	tables, err := conn.ListTables()
+	if err != nil {
+		return fmt.Errorf("could not list NFT tables: %v", err)
+	}
+
+	var table *nftables.Table = nil
+	for _, t := range tables {
+		if t.Name == tableName {
+			if table == nil {
+				table = t
+			} else {
+				return fmt.Errorf("found two tables with name %s", tableName)
+			}
+		}
+	}
+	if table == nil {
+		return fmt.Errorf("could not find table %s", tableName)
+	}
+
+	if ip4 != nil {
+		ip4bin := ip4.To4()
+		if ip4bin == nil {
+			return fmt.Errorf("ipv4 must be a valid IPv4 address")
+		}
+
+		set4, err := conn.GetSetByName(table, set4name)
+		if err != nil {
+			return fmt.Errorf("could not find IPv4 NFT set %s: %v", set4name, err)
+		}
+		if set4.KeyType.GetNFTMagic() != nftables.TypeIPAddr.GetNFTMagic() {
+			return fmt.Errorf("the NFT set %s is not of type ip", set4name)
+		}
+
+		conn.FlushSet(set4)
+
+		err = conn.SetAddElements(set4, []nftables.SetElement{{Key: ip4bin}})
+		if err != nil {
+			return fmt.Errorf("failed to add IP %v to set %s: %v", ip4, set4name, err)
+		}
+	}
+
+	if ip6 != nil {
+		ip6bin := ip6.To16()
+		if ip6bin == nil {
+			return fmt.Errorf("ipv6 must be a valid IPv6 address")
+		}
+
+		set6, err := conn.GetSetByName(table, set6name)
+		if err != nil {
+			return fmt.Errorf("could not find IPv6 NFT set %s: %v", set6name, err)
+		}
+		if set6.KeyType.GetNFTMagic() != nftables.TypeIP6Addr.GetNFTMagic() {
+			return fmt.Errorf("the NFT set %s is not of type ip6", set6name)
+		}
+
+		conn.FlushSet(set6)
+
+		err = conn.SetAddElements(set6, []nftables.SetElement{{Key: ip6bin}})
+		if err != nil {
+			return fmt.Errorf("failed to add IP %v to set %s: %v", ip6, set6name, err)
+		}
+	}
+
+	conn.Flush()
+	return nil
+}