tests, netlink: added tests for netlink functions

daemon/netlink/socket_test.go

@@ -0,0 +1,110 @@
+package netlink
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+type Connection struct {
+	SrcIP    net.IP
+	DstIP    net.IP
+	Protocol string
+	SrcPort  uint
+	DstPort  uint
+	OutConn  net.Conn
+	Listener net.Listener
+}
+
+func EstablishConnection(proto, dst string) (net.Conn, error) {
+	c, err := net.Dial(proto, dst)
+	if err != nil {
+		fmt.Println(err)
+		return nil, err
+	}
+	return c, nil
+}
+
+func ListenOnPort(proto, port string) (net.Listener, error) {
+	// TODO: UDP -> ListenUDP() or ListenPacket()
+	l, err := net.Listen(proto, port)
+	if err != nil {
+		fmt.Println(err)
+		return nil, err
+	}
+	return l, nil
+}
+
+func setupConnection(proto string, connChan chan *Connection) {
+	listnr, _ := ListenOnPort(proto, "127.0.0.1:55555")
+	conn, err := EstablishConnection(proto, "127.0.0.1:55555")
+	if err != nil {
+		connChan <- nil
+		return
+	}
+	laddr := strings.Split(conn.LocalAddr().String(), ":")
+	daddr := strings.Split(conn.RemoteAddr().String(), ":")
+	sport, _ := strconv.Atoi(laddr[1])
+	dport, _ := strconv.Atoi(daddr[1])
+
+	lconn := &Connection{
+		SrcPort:  uint(sport),
+		DstPort:  uint(dport),
+		SrcIP:    net.ParseIP(laddr[0]),
+		DstIP:    net.ParseIP(daddr[0]),
+		Protocol: "tcp",
+		Listener: listnr,
+		OutConn:  conn,
+	}
+	connChan <- lconn
+}
+
+// TestNetlinkQueries tests queries to the kernel to get the inode of a connection.
+// When using ProcFS as monitor method, we need that value to get the PID of an application.
+// We also need it if for any reason auditd or ebpf doesn't return the PID of the application.
+// TODO: test all the cases described in the GetSocketInfo() description.
+func TestNetlinkTCPQueries(t *testing.T) {
+	connChan := make(chan *Connection)
+	go setupConnection("tcp", connChan)
+	conn := <-connChan
+	if conn == nil {
+		t.Error("TestParseTCPConnection, conn nil")
+	}
+
+	var inodes []int
+	uid := -1
+	t.Run("Test GetSocketInfo", func(t *testing.T) {
+		uid, inodes = GetSocketInfo("tcp", conn.SrcIP, conn.SrcPort, conn.DstIP, conn.DstPort)
+
+		if len(inodes) == 0 {
+			t.Error("inodes empty")
+		}
+		if uid != os.Getuid() {
+			t.Error("GetSocketInfo UID error:", uid, os.Getuid())
+		}
+	})
+
+	t.Run("Test GetSocketInfoByInode", func(t *testing.T) {
+		socket, err := GetSocketInfoByInode(fmt.Sprint(inodes[0]))
+		if err != nil {
+			t.Error("GetSocketInfoByInode error:", err)
+		}
+		if socket == nil {
+			t.Error("GetSocketInfoByInode inode not found")
+		}
+		if socket.ID.SourcePort != uint16(conn.SrcPort) {
+			t.Error("GetSocketInfoByInode dstPort error:", socket)
+		}
+		if socket.ID.DestinationPort != uint16(conn.DstPort) {
+			t.Error("GetSocketInfoByInode dstPort error:", socket)
+		}
+		if socket.UID != uint32(os.Getuid()) {
+			t.Error("GetSocketInfoByInode UID error:", socket, os.Getuid())
+		}
+	})
+
+	conn.Listener.Close()
+}