--- /dev/null
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf_test
+
+import (
+ "net"
+ "testing"
+
+ "golang.org/x/net/bpf"
+ "golang.org/x/net/ipv4"
+)
+
+func TestVMLoadAbsoluteOffsetOutOfBounds(t *testing.T) {
+ vm, done, err := testVM(t, []bpf.Instruction{
+ bpf.LoadAbsolute{
+ Off: 100,
+ Size: 2,
+ },
+ bpf.RetA{},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+ defer done()
+
+ out, err := vm.Run([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0, 1, 2, 3,
+ })
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 0, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func TestVMLoadAbsoluteOffsetPlusSizeOutOfBounds(t *testing.T) {
+ vm, done, err := testVM(t, []bpf.Instruction{
+ bpf.LoadAbsolute{
+ Off: 8,
+ Size: 2,
+ },
+ bpf.RetA{},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+ defer done()
+
+ out, err := vm.Run([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0,
+ })
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 0, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func TestVMLoadAbsoluteBadInstructionSize(t *testing.T) {
+ _, _, err := testVM(t, []bpf.Instruction{
+ bpf.LoadAbsolute{
+ Size: 5,
+ },
+ bpf.RetA{},
+ })
+ if errStr(err) != "assembling instruction 1: invalid load byte length 0" {
+ t.Fatalf("unexpected error: %v", err)
+ }
+}
+
+func TestVMLoadConstantOK(t *testing.T) {
+ vm, done, err := testVM(t, []bpf.Instruction{
+ bpf.LoadConstant{
+ Dst: bpf.RegX,
+ Val: 9,
+ },
+ bpf.TXA{},
+ bpf.RetA{},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+ defer done()
+
+ out, err := vm.Run([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0,
+ })
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 1, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func TestVMLoadIndirectOutOfBounds(t *testing.T) {
+ vm, done, err := testVM(t, []bpf.Instruction{
+ bpf.LoadIndirect{
+ Off: 100,
+ Size: 1,
+ },
+ bpf.RetA{},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+ defer done()
+
+ out, err := vm.Run([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0,
+ })
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 0, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func TestVMLoadMemShiftOutOfBounds(t *testing.T) {
+ vm, done, err := testVM(t, []bpf.Instruction{
+ bpf.LoadMemShift{
+ Off: 100,
+ },
+ bpf.RetA{},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+ defer done()
+
+ out, err := vm.Run([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ 0,
+ })
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 0, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+const (
+ dhcp4Port = 53
+)
+
+func TestVMLoadMemShiftLoadIndirectNoResult(t *testing.T) {
+ vm, in, done := testDHCPv4(t)
+ defer done()
+
+ // Append mostly empty UDP header with incorrect DHCPv4 port
+ in = append(in, []byte{
+ 0, 0,
+ 0, dhcp4Port + 1,
+ 0, 0,
+ 0, 0,
+ }...)
+
+ out, err := vm.Run(in)
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := 0, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func TestVMLoadMemShiftLoadIndirectOK(t *testing.T) {
+ vm, in, done := testDHCPv4(t)
+ defer done()
+
+ // Append mostly empty UDP header with correct DHCPv4 port
+ in = append(in, []byte{
+ 0, 0,
+ 0, dhcp4Port,
+ 0, 0,
+ 0, 0,
+ }...)
+
+ out, err := vm.Run(in)
+ if err != nil {
+ t.Fatalf("unexpected error while running program: %v", err)
+ }
+ if want, got := len(in)-8, out; want != got {
+ t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
+ want, got)
+ }
+}
+
+func testDHCPv4(t *testing.T) (virtualMachine, []byte, func()) {
+ // DHCPv4 test data courtesy of David Anderson:
+ // https://github.com/google/netboot/blob/master/dhcp4/conn_linux.go#L59-L70
+ vm, done, err := testVM(t, []bpf.Instruction{
+ // Load IPv4 packet length
+ bpf.LoadMemShift{Off: 8},
+ // Get UDP dport
+ bpf.LoadIndirect{Off: 8 + 2, Size: 2},
+ // Correct dport?
+ bpf.JumpIf{Cond: bpf.JumpEqual, Val: dhcp4Port, SkipFalse: 1},
+ // Accept
+ bpf.RetConstant{Val: 1500},
+ // Ignore
+ bpf.RetConstant{Val: 0},
+ })
+ if err != nil {
+ t.Fatalf("failed to load BPF program: %v", err)
+ }
+
+ // Minimal requirements to make a valid IPv4 header
+ h := &ipv4.Header{
+ Len: ipv4.HeaderLen,
+ Src: net.IPv4(192, 168, 1, 1),
+ Dst: net.IPv4(192, 168, 1, 2),
+ }
+ hb, err := h.Marshal()
+ if err != nil {
+ t.Fatalf("failed to marshal IPv4 header: %v", err)
+ }
+
+ hb = append([]byte{
+ 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff,
+ }, hb...)
+
+ return vm, hb, done
+}
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