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authorIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
committerIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
commitac324f646ee3cb7955b0b45a7453aeb9671cbdf1 (patch)
tree0cbc5018e8807421d701d190dc20525726c7ca76 /test/packetimpact/testbench/rawsockets.go
parent352ae1022ce19de28fc72e034cc469872ad79d06 (diff)
parent6d0c5803d557d453f15ac6f683697eeb46dab680 (diff)
Merge branch 'master' into ip-forwarding
- Merges aleksej-paschenko's with HEAD - Adds vfs2 support for ip_forward
Diffstat (limited to 'test/packetimpact/testbench/rawsockets.go')
-rw-r--r--test/packetimpact/testbench/rawsockets.go188
1 files changed, 188 insertions, 0 deletions
diff --git a/test/packetimpact/testbench/rawsockets.go b/test/packetimpact/testbench/rawsockets.go
new file mode 100644
index 000000000..57e822725
--- /dev/null
+++ b/test/packetimpact/testbench/rawsockets.go
@@ -0,0 +1,188 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package testbench
+
+import (
+ "encoding/binary"
+ "fmt"
+ "math"
+ "net"
+ "testing"
+ "time"
+
+ "golang.org/x/sys/unix"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Sniffer can sniff raw packets on the wire.
+type Sniffer struct {
+ fd int
+}
+
+func htons(x uint16) uint16 {
+ buf := [2]byte{}
+ binary.BigEndian.PutUint16(buf[:], x)
+ return usermem.ByteOrder.Uint16(buf[:])
+}
+
+// NewSniffer creates a Sniffer connected to *device.
+func NewSniffer(t *testing.T) (Sniffer, error) {
+ t.Helper()
+
+ snifferFd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_RAW, int(htons(unix.ETH_P_ALL)))
+ if err != nil {
+ return Sniffer{}, err
+ }
+ if err := unix.SetsockoptInt(snifferFd, unix.SOL_SOCKET, unix.SO_RCVBUFFORCE, 1); err != nil {
+ t.Fatalf("can't set sockopt SO_RCVBUFFORCE to 1: %s", err)
+ }
+ if err := unix.SetsockoptInt(snifferFd, unix.SOL_SOCKET, unix.SO_RCVBUF, 1e7); err != nil {
+ t.Fatalf("can't setsockopt SO_RCVBUF to 10M: %s", err)
+ }
+ return Sniffer{
+ fd: snifferFd,
+ }, nil
+}
+
+// maxReadSize should be large enough for the maximum frame size in bytes. If a
+// packet too large for the buffer arrives, the test will get a fatal error.
+const maxReadSize int = 65536
+
+// Recv tries to read one frame until the timeout is up.
+func (s *Sniffer) Recv(t *testing.T, timeout time.Duration) []byte {
+ t.Helper()
+
+ deadline := time.Now().Add(timeout)
+ for {
+ timeout = deadline.Sub(time.Now())
+ if timeout <= 0 {
+ return nil
+ }
+ whole, frac := math.Modf(timeout.Seconds())
+ tv := unix.Timeval{
+ Sec: int64(whole),
+ Usec: int64(frac * float64(time.Microsecond/time.Second)),
+ }
+
+ if err := unix.SetsockoptTimeval(s.fd, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &tv); err != nil {
+ t.Fatalf("can't setsockopt SO_RCVTIMEO: %s", err)
+ }
+
+ buf := make([]byte, maxReadSize)
+ nread, _, err := unix.Recvfrom(s.fd, buf, unix.MSG_TRUNC)
+ if err == unix.EINTR || err == unix.EAGAIN {
+ // There was a timeout.
+ continue
+ }
+ if err != nil {
+ t.Fatalf("can't read: %s", err)
+ }
+ if nread > maxReadSize {
+ t.Fatalf("received a truncated frame of %d bytes, want at most %d bytes", nread, maxReadSize)
+ }
+ return buf[:nread]
+ }
+}
+
+// Drain drains the Sniffer's socket receive buffer by receiving until there's
+// nothing else to receive.
+func (s *Sniffer) Drain(t *testing.T) {
+ t.Helper()
+
+ flags, err := unix.FcntlInt(uintptr(s.fd), unix.F_GETFL, 0)
+ if err != nil {
+ t.Fatalf("failed to get sniffer socket fd flags: %s", err)
+ }
+ nonBlockingFlags := flags | unix.O_NONBLOCK
+ if _, err := unix.FcntlInt(uintptr(s.fd), unix.F_SETFL, nonBlockingFlags); err != nil {
+ t.Fatalf("failed to make sniffer socket non-blocking with flags %b: %s", nonBlockingFlags, err)
+ }
+ for {
+ buf := make([]byte, maxReadSize)
+ _, _, err := unix.Recvfrom(s.fd, buf, unix.MSG_TRUNC)
+ if err == unix.EINTR || err == unix.EAGAIN || err == unix.EWOULDBLOCK {
+ break
+ }
+ }
+ if _, err := unix.FcntlInt(uintptr(s.fd), unix.F_SETFL, flags); err != nil {
+ t.Fatalf("failed to restore sniffer socket fd flags to %b: %s", flags, err)
+ }
+}
+
+// close the socket that Sniffer is using.
+func (s *Sniffer) close() error {
+ if err := unix.Close(s.fd); err != nil {
+ return fmt.Errorf("can't close sniffer socket: %w", err)
+ }
+ s.fd = -1
+ return nil
+}
+
+// Injector can inject raw frames.
+type Injector struct {
+ fd int
+}
+
+// NewInjector creates a new injector on *device.
+func NewInjector(t *testing.T) (Injector, error) {
+ t.Helper()
+
+ ifInfo, err := net.InterfaceByName(Device)
+ if err != nil {
+ return Injector{}, err
+ }
+
+ var haddr [8]byte
+ copy(haddr[:], ifInfo.HardwareAddr)
+ sa := unix.SockaddrLinklayer{
+ Protocol: unix.ETH_P_IP,
+ Ifindex: ifInfo.Index,
+ Halen: uint8(len(ifInfo.HardwareAddr)),
+ Addr: haddr,
+ }
+
+ injectFd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_RAW, int(htons(unix.ETH_P_ALL)))
+ if err != nil {
+ return Injector{}, err
+ }
+ if err := unix.Bind(injectFd, &sa); err != nil {
+ return Injector{}, err
+ }
+ return Injector{
+ fd: injectFd,
+ }, nil
+}
+
+// Send a raw frame.
+func (i *Injector) Send(t *testing.T, b []byte) {
+ t.Helper()
+
+ n, err := unix.Write(i.fd, b)
+ if err != nil {
+ t.Fatalf("can't write bytes of len %d: %s", len(b), err)
+ }
+ if n != len(b) {
+ t.Fatalf("got %d bytes written, want %d", n, len(b))
+ }
+}
+
+// close the underlying socket.
+func (i *Injector) close() error {
+ if err := unix.Close(i.fd); err != nil {
+ return fmt.Errorf("can't close sniffer socket: %w", err)
+ }
+ i.fd = -1
+ return nil
+}