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factor dnsmasq code into testing helper, verify dhcp6 client id

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This commit is contained in:
Michael Stapelberg 2018-06-02 18:05:09 +02:00
parent 7d2205c295
commit 1e62de50bd
4 changed files with 262 additions and 166 deletions
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149
integrationdhcpv4_test.go
View File

@ -1,25 +1,18 @@
package integration_test
import (
"bytes"
"io/ioutil"
"log"
"net"
"os"
"os/exec"
"regexp"
"strconv"
"strings"
"testing"
"time"
"router7/internal/dhcp4"
"router7/internal/testing/dnsmasq"
"github.com/google/go-cmp/cmp"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/google/gopacket/pcap"
"github.com/google/gopacket/pcapgo"
)
func TestDHCPv4(t *testing.T) {
@ -51,77 +44,41 @@ func TestDHCPv4(t *testing.T) {
ready.Close() // dnsmasq will re-create the file anyway
defer os.Remove(ready.Name()) // dnsmasq does not clean up its pid file
var stderr bytes.Buffer
dnsmasq := exec.Command("ip", "netns", "exec", ns, "dnsmasq",
"--keep-in-foreground", // cannot use --no-daemon because we need --pid-file
"--log-facility=-", // log to stderr
"--pid-file="+ready.Name(),
"--bind-interfaces",
"--interface=veth0b",
"--dhcp-range=192.168.23.2,192.168.23.10",
"--dhcp-range=::1,::10,constructor:veth0b",
"--dhcp-authoritative", // eliminate timeouts
"--no-ping", // disable ICMP confirmation of unused addresses to eliminate tedious timeout
"--leasefile-ro", // do not create a lease database
)
dnsmasq.Stdout = os.Stdout
dnsmasq.Stderr = &stderr
if err := dnsmasq.Start(); err != nil {
t.Fatal(err)
}
done := false // TODO: fix data race
go func() {
err := dnsmasq.Wait()
if !done {
t.Fatalf("dnsmasq exited prematurely: %v", err)
}
}()
defer func() {
done = true
dnsmasq.Process.Kill()
}()
dnsmasq := dnsmasq.Run(t)
defer dnsmasq.Kill()
// TODO(later): use inotify instead of polling
// Wait for dnsmasq to write its process id, at which point it is already
// listening for requests.
for {
b, err := ioutil.ReadFile(ready.Name())
if err != nil {
t.Fatal(err)
}
if strings.TrimSpace(string(b)) == strconv.Itoa(dnsmasq.Process.Pid) {
break
}
time.Sleep(10 * time.Millisecond)
}
f, err := os.Create("/tmp/pcap")
if err != nil {
t.Fatal(err)
}
defer f.Close()
pcapw := pcapgo.NewWriter(f)
if err := pcapw.WriteFileHeader(1600, layers.LinkTypeEthernet); err != nil {
t.Fatal(err)
}
handle, err := pcap.OpenLive("veth0a", 1600, true, pcap.BlockForever)
if err != nil {
t.Fatal(err)
}
pkgsrc := gopacket.NewPacketSource(handle, handle.LinkType())
closed := make(chan struct{})
go func() {
for packet := range pkgsrc.Packets() {
if packet.Layer(layers.LayerTypeDHCPv4) != nil {
log.Printf("packet: %+v", packet)
if err := pcapw.WritePacket(packet.Metadata().CaptureInfo, packet.Data()); err != nil {
t.Fatalf("pcap.WritePacket(): %v", err)
}
}
}
close(closed)
}()
// TODO: test the capture daemon
// f, err := os.Create("/tmp/pcap")
// if err != nil {
// t.Fatal(err)
// }
// defer f.Close()
// pcapw := pcapgo.NewWriter(f)
// if err := pcapw.WriteFileHeader(1600, layers.LinkTypeEthernet); err != nil {
// t.Fatal(err)
// }
// handle, err := pcap.OpenLive("veth0a", 1600, true, pcap.BlockForever)
// if err != nil {
// t.Fatal(err)
// }
// pkgsrc := gopacket.NewPacketSource(handle, handle.LinkType())
// closed := make(chan struct{})
// go func() {
// for packet := range pkgsrc.Packets() {
// if packet.Layer(layers.LayerTypeDHCPv4) != nil {
// log.Printf("packet: %+v", packet)
// if err := pcapw.WritePacket(packet.Metadata().CaptureInfo, packet.Data()); err != nil {
// t.Fatalf("pcap.WritePacket(): %v", err)
// }
// }
// }
// close(closed)
// }()
// // TODO: test the capture daemon
// defer func() {
// time.Sleep(1 * time.Second)
// handle.Close()
// <-closed
// }()
iface, err := net.InterfaceByName("veth0a")
if err != nil {
@ -147,27 +104,8 @@ func TestDHCPv4(t *testing.T) {
// TODO: alternatively, replace bytes.Buffer with a pipe and read from that
time.Sleep(100 * time.Millisecond) // give dnsmasq some time to process the DHCPRELEASE
// Kill dnsmasq to flush its log
done = true
dnsmasq.Process.Kill()
mac := iface.HardwareAddr.String()
lines := strings.Split(strings.TrimSpace(stderr.String()), "\n")
var dhcpActionRe = regexp.MustCompile(` (DHCP[^ ]*)`)
var actions []string
for _, line := range lines {
if !strings.HasPrefix(line, "dnsmasq-dhcp") {
continue
}
if !strings.Contains(line, mac) {
continue
}
matches := dhcpActionRe.FindStringSubmatch(line)
if matches == nil {
continue
}
actions = append(actions, matches[1])
}
dnsmasq.Kill() // to flush logs
got := dnsmasq.Actions()
want := []string{
"DHCPDISCOVER(veth0b)",
"DHCPOFFER(veth0b)",
@ -175,11 +113,14 @@ func TestDHCPv4(t *testing.T) {
"DHCPACK(veth0b)",
"DHCPRELEASE(veth0b)",
}
if diff := cmp.Diff(actions, want); diff != "" {
actionOnly := func(line string) string {
result := line
if idx := strings.Index(result, " "); idx > -1 {
return result[:idx]
}
return result
}
if diff := cmp.Diff(got, want, cmp.Transformer("ActionOnly", actionOnly)); diff != "" {
t.Errorf("dnsmasq log does not contain expected DHCP sequence: diff (-got +want):\n%s", diff)
}
time.Sleep(1 * time.Second)
handle.Close()
<-closed
}

92
integrationdhcpv6_test.go
View File

@ -1,19 +1,19 @@
package integration_test
import (
"io/ioutil"
"os"
"os/exec"
"strconv"
"regexp"
"strings"
"testing"
"time"
"router7/internal/dhcp6"
"router7/internal/testing/dnsmasq"
"github.com/google/go-cmp/cmp"
)
var v6AddrRe = regexp.MustCompile(`2001:db8::[^ ]+`)
func TestDHCPv6(t *testing.T) {
const ns = "ns0" // name of the network namespace to use for this test
@ -43,57 +43,10 @@ func TestDHCPv6(t *testing.T) {
}
}
ready, err := ioutil.TempFile("", "router7")
if err != nil {
t.Fatal(err)
}
ready.Close() // dnsmasq will re-create the file anyway
defer os.Remove(ready.Name()) // dnsmasq does not clean up its pid file
dnsmasq := dnsmasq.Run(t)
defer dnsmasq.Kill()
dnsmasq := exec.Command("ip", "netns", "exec", ns, "dnsmasq",
"--keep-in-foreground", // cannot use --no-daemon because we need --pid-file
"--log-facility=-", // log to stderr
"--pid-file="+ready.Name(),
"--bind-interfaces",
"--interface=veth0b",
"--dhcp-range=192.168.23.2,192.168.23.10",
"--dhcp-range=::1,::10,constructor:veth0b",
"--dhcp-authoritative", // eliminate timeouts
"--no-ping", // disable ICMP confirmation of unused addresses to eliminate tedious timeout
"--leasefile-ro", // do not create a lease database
)
dnsmasq.Stdout = os.Stdout
dnsmasq.Stderr = os.Stderr
if err := dnsmasq.Start(); err != nil {
t.Fatal(err)
}
done := false // TODO: fix data race
go func() {
err := dnsmasq.Wait()
if !done {
t.Fatalf("dnsmasq exited prematurely: %v", err)
}
}()
defer func() {
done = true
dnsmasq.Process.Kill()
}()
// TODO(later): use inotify instead of polling
// Wait for dnsmasq to write its process id, at which point it is already
// listening for requests.
for {
b, err := ioutil.ReadFile(ready.Name())
if err != nil {
t.Fatal(err)
}
if strings.TrimSpace(string(b)) == strconv.Itoa(dnsmasq.Process.Pid) {
break
}
time.Sleep(10 * time.Millisecond)
}
// f, err := os.Create("/tmp/pcap")
// f, err := os.Create("/tmp/pcap6")
// if err != nil {
// t.Fatal(err)
// }
@ -110,19 +63,26 @@ func TestDHCPv6(t *testing.T) {
// closed := make(chan struct{})
// go func() {
// for packet := range pkgsrc.Packets() {
// if packet.Layer(layers.LayerTypeDHCPv4) != nil {
// log.Printf("packet: %+v", packet)
// //if packet.Layer(layers.LayerTypeDHCPv6) != nil {
// fmt.Printf("packet: %+v\n", packet)
// if err := pcapw.WritePacket(packet.Metadata().CaptureInfo, packet.Data()); err != nil {
// t.Fatalf("pcap.WritePacket(): %v", err)
// }
// }
// //}
// }
// close(closed)
// }()
// // TODO: test the capture daemon
// defer func() {
// time.Sleep(1 * time.Second)
// handle.Close()
// <-closed
// }()
duid := []byte{0x00, 0x0a, 0x00, 0x03, 0x00, 0x01, 0x4c, 0x5e, 0xc, 0x41, 0xbf, 0x39}
c, err := dhcp6.NewClient(dhcp6.ClientConfig{
InterfaceName: "veth0a",
DUID: duid,
})
if err != nil {
t.Fatal(err)
@ -139,7 +99,19 @@ func TestDHCPv6(t *testing.T) {
t.Fatalf("unexpected config: diff (-got +want):\n%s", diff)
}
// time.Sleep(1 * time.Second)
// handle.Close()
// <-closed
{
got := dnsmasq.Actions()
want := []string{
"DHCPSOLICIT(veth0b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
"DHCPADVERTISE(veth0b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
"DHCPREQUEST(veth0b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
"DHCPREPLY(veth0b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
}
withoutMac := func(line string) string {
return v6AddrRe.ReplaceAllString(strings.TrimSpace(line), "")
}
if diff := cmp.Diff(got, want, cmp.Transformer("WithoutMAC", withoutMac)); diff != "" {
t.Errorf("dnsmasq log does not contain expected DHCP sequence: diff (-got +want):\n%s", diff)
}
}
}

147
internal/testing/dnsmasq/dnsmasq.go Normal file
View File

@ -0,0 +1,147 @@
// Package dnsmasq manages the process lifecycle of the dnsmasq(8) DHCP server.
package dnsmasq
import (
"bufio"
"fmt"
"io"
"io/ioutil"
"os"
"os/exec"
"regexp"
"strconv"
"strings"
"sync"
"testing"
"time"
)
// Process is a handle for a dnsmasq(8) process.
type Process struct {
killed bool // whether Kill was called
done chan struct{} // closed when Done() is called
wait chan struct{} // closed when Wait() returns
dnsmasq *exec.Cmd
mu sync.Mutex
actions []string
}
var dhcpActionRe = regexp.MustCompile(` (DHCP[^(]+\(.*)$`)
// Run starts a dnsmasq(8) process and returns a handle to it.
func Run(t *testing.T, args ...string) *Process {
const ns = "ns0" // TODO: configurable?
ready, err := ioutil.TempFile("", "router7")
if err != nil {
t.Fatal(err)
}
ready.Close() // dnsmasq will re-create the file anyway
defer os.Remove(ready.Name()) // dnsmasq does not clean up its pid file
// iface, err := net.InterfaceByName("veth0a")
// if err != nil {
// t.Fatal(err)
// }
p := &Process{
wait: make(chan struct{}),
}
p.dnsmasq = exec.Command("ip", "netns", "exec", ns, "dnsmasq",
"--keep-in-foreground", // cannot use --no-daemon because we need --pid-file
"--log-facility=-", // log to stderr
"--pid-file="+ready.Name(),
"--bind-interfaces",
"--interface=veth0b",
"--dhcp-range=192.168.23.2,192.168.23.10",
"--dhcp-range=::1,::10,constructor:veth0b",
"--dhcp-authoritative", // eliminate timeouts
"--no-ping", // disable ICMP confirmation of unused addresses to eliminate tedious timeout
"--leasefile-ro", // do not create a lease database
)
p.dnsmasq.Stdout = os.Stdout
stderr := make(chan string)
r, w := io.Pipe()
scanner := bufio.NewScanner(r)
go func() {
for scanner.Scan() {
stderr <- scanner.Text()
}
close(stderr)
}()
p.dnsmasq.Stderr = w
//mac := iface.HardwareAddr.String()
go func() {
for line := range stderr {
fmt.Printf("dnsmasq log line: %s\n", line)
if !strings.HasPrefix(line, "dnsmasq-dhcp") {
continue
}
// if !strings.Contains(line, mac) {
// continue
// }
matches := dhcpActionRe.FindStringSubmatch(line)
if matches == nil {
continue
}
p.mu.Lock()
p.actions = append(p.actions, matches[1])
p.mu.Unlock()
}
}()
if err := p.dnsmasq.Start(); err != nil {
t.Fatal(err)
}
p.done = make(chan struct{})
go func() {
err := p.dnsmasq.Wait()
close(p.wait)
select {
case <-p.done:
return // test done, any errors are from our Kill()
default:
t.Fatalf("dnsmasq exited prematurely: %v", err)
}
}()
// TODO(later): use inotify instead of polling
// Wait for dnsmasq to write its process id, at which point it is already
// listening for requests.
for {
b, err := ioutil.ReadFile(ready.Name())
if err != nil {
t.Fatal(err)
}
if strings.TrimSpace(string(b)) == strconv.Itoa(p.dnsmasq.Process.Pid) {
break
}
time.Sleep(10 * time.Millisecond)
}
return p
}
// Kill shuts down the dnsmasq(8) process and returns once waitpid returns.
func (p *Process) Kill() {
if p.killed {
return
}
p.killed = true
close(p.done)
p.dnsmasq.Process.Kill()
<-p.wait
}
// Actions returns a string slice of dnsmasq(8) actions (as per its stderr log)
// received up until now. Use Kill before calling Actions to force a log flush.
func (p *Process) Actions() []string {
p.mu.Lock()
defer p.mu.Unlock()
result := make([]string, len(p.actions))
copy(result, p.actions)
return result
}

36
internal/testing/dnsmasq/example_test.go Normal file
View File

@ -0,0 +1,36 @@
package dnsmasq_test
import (
"router7/internal/testing/dnsmasq"
"strings"
"testing"
"github.com/google/go-cmp/cmp"
)
func Example(t *testing.T) {
dnsmasq := dnsmasq.Run(t)
defer dnsmasq.Kill()
// test code here
// optionally introspect the dnsmasq log:
dnsmasq.Kill()
got := dnsmasq.Actions()
want := []string{
"DHCPDISCOVER(veth0b)",
"DHCPOFFER(veth0b)",
"DHCPREQUEST(veth0b)",
"DHCPACK(veth0b)",
"DHCPRELEASE(veth0b)",
}
actionOnly := func(line string) string {
result := line
if idx := strings.Index(result, " "); idx > -1 {
return result[:idx]
}
return result
}
if diff := cmp.Diff(got, want, cmp.Transformer("ActionOnly", actionOnly)); diff != "" {
t.Errorf("dnsmasq log does not contain expected DHCP sequence: diff (-got +want):\n%s", diff)
}
}