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package egress
import (
"context"
"net"
"net/netip"
"slices"
"syscall"
"testing"
"golang.org/x/sys/unix"
)
func TestDHCPServersAreRead(t *testing.T) {
packet := "op = BOOTREPLY\nhtype = 1\nyiaddr = 192.168.1.20\noptions:\n" +
"Options count is 9\n" +
"router (ip_mult): {192.168.1.1}\n" +
"domain_name_server (ip_mult): {192.168.1.1, 8.8.8.8}\n" +
"end (none):\n"
got := dhcpServers(packet)
want := []netip.Addr{netip.MustParseAddr("192.168.1.1"), netip.MustParseAddr("8.8.8.8")}
if !slices.Equal(got, want) {
t.Fatalf("got %v, want %v", got, want)
}
if got := dhcpServers("op = BOOTREPLY\n"); len(got) != 0 {
t.Fatalf("got %v from a packet without servers", got)
}
}
func TestTheMacDefaultRouteAndItsLookupAgree(t *testing.T) {
st := &tunState{index: 0xfffffff0}
index, ok := defaultInterface(false, st)
if !ok {
t.Skip("no IPv4 default route")
}
best, ok := bestInterface(netip.MustParseAddr("192.0.2.1"))
if !ok || best != index {
t.Fatalf("the route to 192.0.2.1 is through %d (%t), the default route through %d", best, ok, index)
}
if _, ok := defaultInterface(false, &tunState{index: index}); ok {
t.Fatal("the TUN's interface was taken for the network")
}
t.Logf("default interface %d, DNS %v", index, dnsServers(st))
}
// A connection made while a TUN runs is bound to the default interface;
// one to this computer is not.
func TestAMacSocketIsBoundToTheNetwork(t *testing.T) {
index, ok := defaultInterface(false, &tunState{index: 0xfffffff0})
if !ok {
t.Skip("no IPv4 default route")
}
SetTun(0xfffffff0, 0)
t.Cleanup(ClearTun)
bound := func(c net.Conn) int {
raw, err := c.(syscall.Conn).SyscallConn()
if err != nil {
t.Fatal(err)
}
var v int
var gerr error
raw.Control(func(fd uintptr) { v, gerr = unix.GetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF) })
if gerr != nil {
t.Fatal(gerr)
}
return v
}
c, err := DialContext(context.Background(), "udp4", "192.0.2.1:9")
if err != nil {
t.Fatal(err)
}
defer c.Close()
if got := bound(c); got != int(index) {
t.Fatalf("bound to %d, want %d", got, index)
}
l, err := net.ListenPacket("udp4", "127.0.0.1:0")
if err != nil {
t.Fatal(err)
}
defer l.Close()
c2, err := DialContext(context.Background(), "udp4", l.LocalAddr().String())
if err != nil {
t.Fatal(err)
}
defer c2.Close()
if got := bound(c2); got != 0 {
t.Fatalf("a loopback socket is bound to %d", got)
}
}
arblant