1// +build linux,!appengine
2
3package dns
4
5import (
6	"bytes"
7	"net"
8	"runtime"
9	"strings"
10	"testing"
11	"time"
12
13	"golang.org/x/net/ipv4"
14	"golang.org/x/net/ipv6"
15)
16
17func TestSetUDPSocketOptions(t *testing.T) {
18	// returns an error if we cannot resolve that address
19	testFamily := func(n, addr string) error {
20		a, err := net.ResolveUDPAddr(n, addr)
21		if err != nil {
22			return err
23		}
24		c, err := net.ListenUDP(n, a)
25		if err != nil {
26			return err
27		}
28		if err := setUDPSocketOptions(c); err != nil {
29			t.Fatalf("failed to set socket options: %v", err)
30		}
31		ch := make(chan *SessionUDP)
32		go func() {
33			// Set some deadline so this goroutine doesn't hang forever
34			c.SetReadDeadline(time.Now().Add(time.Minute))
35			b := make([]byte, 1)
36			_, sess, err := ReadFromSessionUDP(c, b)
37			if err != nil {
38				t.Errorf("failed to read from conn: %v", err)
39				// fallthrough to chan send below
40			}
41			ch <- sess
42		}()
43
44		c2, err := net.Dial("udp", c.LocalAddr().String())
45		if err != nil {
46			t.Fatalf("failed to dial udp: %v", err)
47		}
48		if _, err := c2.Write([]byte{1}); err != nil {
49			t.Fatalf("failed to write to conn: %v", err)
50		}
51		sess := <-ch
52		if sess == nil {
53			// t.Error was already called in the goroutine above.
54			t.FailNow()
55		}
56		if len(sess.context) == 0 {
57			t.Fatalf("empty session context: %v", sess)
58		}
59		ip := parseDstFromOOB(sess.context)
60		if ip == nil {
61			t.Fatalf("failed to parse dst: %v", sess)
62		}
63		if !strings.Contains(c.LocalAddr().String(), ip.String()) {
64			t.Fatalf("dst was different than listen addr: %v != %v", ip.String(), c.LocalAddr().String())
65		}
66		return nil
67	}
68
69	// we require that ipv4 be supported
70	if err := testFamily("udp4", "127.0.0.1:0"); err != nil {
71		t.Fatalf("failed to test socket options on IPv4: %v", err)
72	}
73	// IPv6 might not be supported so these will just log
74	if err := testFamily("udp6", "[::1]:0"); err != nil {
75		t.Logf("failed to test socket options on IPv6-only: %v", err)
76	}
77	if err := testFamily("udp", "[::1]:0"); err != nil {
78		t.Logf("failed to test socket options on IPv6/IPv4: %v", err)
79	}
80}
81
82func TestParseDstFromOOB(t *testing.T) {
83	if runtime.GOARCH != "amd64" {
84		// The cmsghdr struct differs in the width (32/64-bit) of
85		// lengths and the struct padding between architectures.
86		// The data below was only written with amd64 in mind, and
87		// thus the test must be skipped on other architectures.
88		t.Skip("skipping test on unsupported architecture")
89	}
90
91	// dst is :ffff:100.100.100.100
92	oob := []byte{36, 0, 0, 0, 0, 0, 0, 0, 41, 0, 0, 0, 50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 100, 100, 100, 100, 2, 0, 0, 0}
93	dst := parseDstFromOOB(oob)
94	dst4 := dst.To4()
95	if dst4 == nil {
96		t.Errorf("failed to parse IPv4 in IPv6: %v", dst)
97	} else if dst4.String() != "100.100.100.100" {
98		t.Errorf("unexpected IPv4: %v", dst4)
99	}
100
101	// dst is 2001:db8::1
102	oob = []byte{36, 0, 0, 0, 0, 0, 0, 0, 41, 0, 0, 0, 50, 0, 0, 0, 32, 1, 13, 184, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0}
103	dst = parseDstFromOOB(oob)
104	dst6 := dst.To16()
105	if dst6 == nil {
106		t.Errorf("failed to parse IPv6: %v", dst)
107	} else if dst6.String() != "2001:db8::1" {
108		t.Errorf("unexpected IPv6: %v", dst4)
109	}
110
111	// dst is 100.100.100.100 but was received on 10.10.10.10
112	oob = []byte{28, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 2, 0, 0, 0, 10, 10, 10, 10, 100, 100, 100, 100, 0, 0, 0, 0}
113	dst = parseDstFromOOB(oob)
114	dst4 = dst.To4()
115	if dst4 == nil {
116		t.Errorf("failed to parse IPv4: %v", dst)
117	} else if dst4.String() != "100.100.100.100" {
118		t.Errorf("unexpected IPv4: %v", dst4)
119	}
120}
121
122func TestCorrectSource(t *testing.T) {
123	if runtime.GOARCH != "amd64" {
124		// See comment above in TestParseDstFromOOB.
125		t.Skip("skipping test on unsupported architecture")
126	}
127
128	// dst is :ffff:100.100.100.100 which should be counted as IPv4
129	oob := []byte{36, 0, 0, 0, 0, 0, 0, 0, 41, 0, 0, 0, 50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 100, 100, 100, 100, 2, 0, 0, 0}
130	soob := correctSource(oob)
131	cm4 := new(ipv4.ControlMessage)
132	cm4.Src = net.ParseIP("100.100.100.100")
133	if !bytes.Equal(soob, cm4.Marshal()) {
134		t.Errorf("unexpected oob for ipv4 address: %v", soob)
135	}
136
137	// dst is 2001:db8::1
138	oob = []byte{36, 0, 0, 0, 0, 0, 0, 0, 41, 0, 0, 0, 50, 0, 0, 0, 32, 1, 13, 184, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0}
139	soob = correctSource(oob)
140	cm6 := new(ipv6.ControlMessage)
141	cm6.Src = net.ParseIP("2001:db8::1")
142	if !bytes.Equal(soob, cm6.Marshal()) {
143		t.Errorf("unexpected oob for IPv6 address: %v", soob)
144	}
145}
146