Rename go files that contain "main" function to main.go.

This is a good Go convention that we should follow.

PiperOrigin-RevId: 378538679

1 files changed, 400 insertions, 0 deletions

diff --git a/test/cmd/test_app/main.go b/test/cmd/test_app/main.go
new file mode 100644
index 000000000..2d08ce2db
--- /dev/null
+++ b/test/cmd/test_app/main.go
@@ -0,0 +1,400 @@
+// Copyright 2018 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.
+
+// Binary test_app is like a swiss knife for tests that need to run anything
+// inside the sandbox. New functionality can be added with new commands.
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	sys "syscall"
+	"time"
+
+	"github.com/google/subcommands"
+	"github.com/kr/pty"
+	"gvisor.dev/gvisor/pkg/test/testutil"
+	"gvisor.dev/gvisor/runsc/flag"
+)
+
+func main() {
+	subcommands.Register(subcommands.HelpCommand(), "")
+	subcommands.Register(subcommands.FlagsCommand(), "")
+	subcommands.Register(new(capability), "")
+	subcommands.Register(new(fdReceiver), "")
+	subcommands.Register(new(fdSender), "")
+	subcommands.Register(new(forkBomb), "")
+	subcommands.Register(new(ptyRunner), "")
+	subcommands.Register(new(reaper), "")
+	subcommands.Register(new(syscall), "")
+	subcommands.Register(new(taskTree), "")
+	subcommands.Register(new(uds), "")
+
+	flag.Parse()
+
+	exitCode := subcommands.Execute(context.Background())
+	os.Exit(int(exitCode))
+}
+
+type uds struct {
+	fileName   string
+	socketPath string
+}
+
+// Name implements subcommands.Command.Name.
+func (*uds) Name() string {
+	return "uds"
+}
+
+// Synopsis implements subcommands.Command.Synopsys.
+func (*uds) Synopsis() string {
+	return "creates unix domain socket client and server. Client sends a contant flow of sequential numbers. Server prints them to --file"
+}
+
+// Usage implements subcommands.Command.Usage.
+func (*uds) Usage() string {
+	return "uds <flags>"
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (c *uds) SetFlags(f *flag.FlagSet) {
+	f.StringVar(&c.fileName, "file", "", "name of output file")
+	f.StringVar(&c.socketPath, "socket", "", "path to socket")
+}
+
+// Execute implements subcommands.Command.Execute.
+func (c *uds) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if c.fileName == "" || c.socketPath == "" {
+		log.Fatalf("Flags cannot be empty, given: fileName: %q, socketPath: %q", c.fileName, c.socketPath)
+		return subcommands.ExitFailure
+	}
+	outputFile, err := os.OpenFile(c.fileName, os.O_WRONLY|os.O_CREATE, 0666)
+	if err != nil {
+		log.Fatal("error opening output file:", err)
+	}
+
+	defer os.Remove(c.socketPath)
+
+	listener, err := net.Listen("unix", c.socketPath)
+	if err != nil {
+		log.Fatalf("error listening on socket %q: %v", c.socketPath, err)
+	}
+
+	go server(listener, outputFile)
+	for i := 0; ; i++ {
+		conn, err := net.Dial("unix", c.socketPath)
+		if err != nil {
+			log.Fatal("error dialing:", err)
+		}
+		if _, err := conn.Write([]byte(strconv.Itoa(i))); err != nil {
+			log.Fatal("error writing:", err)
+		}
+		conn.Close()
+		time.Sleep(100 * time.Millisecond)
+	}
+}
+
+func server(listener net.Listener, out *os.File) {
+	buf := make([]byte, 16)
+
+	for {
+		c, err := listener.Accept()
+		if err != nil {
+			log.Fatal("error accepting connection:", err)
+		}
+		nr, err := c.Read(buf)
+		if err != nil {
+			log.Fatal("error reading from buf:", err)
+		}
+		data := buf[0:nr]
+		fmt.Fprint(out, string(data)+"\n")
+	}
+}
+
+type taskTree struct {
+	depth int
+	width int
+	pause bool
+}
+
+// Name implements subcommands.Command.
+func (*taskTree) Name() string {
+	return "task-tree"
+}
+
+// Synopsis implements subcommands.Command.
+func (*taskTree) Synopsis() string {
+	return "creates a tree of tasks"
+}
+
+// Usage implements subcommands.Command.
+func (*taskTree) Usage() string {
+	return "task-tree <flags>"
+}
+
+// SetFlags implements subcommands.Command.
+func (c *taskTree) SetFlags(f *flag.FlagSet) {
+	f.IntVar(&c.depth, "depth", 1, "number of levels to create")
+	f.IntVar(&c.width, "width", 1, "number of tasks at each level")
+	f.BoolVar(&c.pause, "pause", false, "whether the tasks should pause perpetually")
+}
+
+// Execute implements subcommands.Command.
+func (c *taskTree) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if c.depth == 0 {
+		log.Printf("Child sleeping, PID: %d\n", os.Getpid())
+		for {
+			time.Sleep(time.Hour)
+		}
+	}
+
+	log.Printf("Parent %d creating %d children, PID: %d\n", c.depth, c.width, os.Getpid())
+
+	stop := testutil.StartReaper()
+	defer stop()
+
+	var cmds []*exec.Cmd
+	for i := 0; i < c.width; i++ {
+		cmd := exec.Command(
+			"/proc/self/exe", c.Name(),
+			"--depth", strconv.Itoa(c.depth-1),
+			"--width", strconv.Itoa(c.width),
+			fmt.Sprintf("--pause=%t", c.pause))
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+
+		if err := cmd.Start(); err != nil {
+			log.Fatal("failed to call self:", err)
+		}
+		cmds = append(cmds, cmd)
+	}
+
+	for _, c := range cmds {
+		c.Wait()
+	}
+
+	if c.pause {
+		log.Printf("Parent %d sleeping, PID: %d\n", c.depth, os.Getpid())
+		for {
+			time.Sleep(time.Hour)
+		}
+	}
+
+	return subcommands.ExitSuccess
+}
+
+type forkBomb struct {
+	delay time.Duration
+}
+
+// Name implements subcommands.Command.
+func (*forkBomb) Name() string {
+	return "fork-bomb"
+}
+
+// Synopsis implements subcommands.Command.
+func (*forkBomb) Synopsis() string {
+	return "creates child process until the end of times"
+}
+
+// Usage implements subcommands.Command.
+func (*forkBomb) Usage() string {
+	return "fork-bomb <flags>"
+}
+
+// SetFlags implements subcommands.Command.
+func (c *forkBomb) SetFlags(f *flag.FlagSet) {
+	f.DurationVar(&c.delay, "delay", 100*time.Millisecond, "amount of time to delay creation of child")
+}
+
+// Execute implements subcommands.Command.
+func (c *forkBomb) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	time.Sleep(c.delay)
+
+	cmd := exec.Command("/proc/self/exe", c.Name())
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		log.Fatal("failed to call self:", err)
+	}
+	return subcommands.ExitSuccess
+}
+
+type reaper struct{}
+
+// Name implements subcommands.Command.
+func (*reaper) Name() string {
+	return "reaper"
+}
+
+// Synopsis implements subcommands.Command.
+func (*reaper) Synopsis() string {
+	return "reaps all children in a loop"
+}
+
+// Usage implements subcommands.Command.
+func (*reaper) Usage() string {
+	return "reaper <flags>"
+}
+
+// SetFlags implements subcommands.Command.
+func (*reaper) SetFlags(*flag.FlagSet) {}
+
+// Execute implements subcommands.Command.
+func (c *reaper) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	stop := testutil.StartReaper()
+	defer stop()
+	select {}
+}
+
+type syscall struct {
+	sysno uint64
+}
+
+// Name implements subcommands.Command.
+func (*syscall) Name() string {
+	return "syscall"
+}
+
+// Synopsis implements subcommands.Command.
+func (*syscall) Synopsis() string {
+	return "syscall makes a syscall"
+}
+
+// Usage implements subcommands.Command.
+func (*syscall) Usage() string {
+	return "syscall <flags>"
+}
+
+// SetFlags implements subcommands.Command.
+func (s *syscall) SetFlags(f *flag.FlagSet) {
+	f.Uint64Var(&s.sysno, "syscall", 0, "syscall to call")
+}
+
+// Execute implements subcommands.Command.
+func (s *syscall) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if _, _, errno := sys.Syscall(uintptr(s.sysno), 0, 0, 0); errno != 0 {
+		fmt.Printf("syscall(%d, 0, 0...) failed: %v\n", s.sysno, errno)
+	} else {
+		fmt.Printf("syscall(%d, 0, 0...) success\n", s.sysno)
+	}
+	return subcommands.ExitSuccess
+}
+
+type capability struct {
+	enabled  uint64
+	disabled uint64
+}
+
+// Name implements subcommands.Command.
+func (*capability) Name() string {
+	return "capability"
+}
+
+// Synopsis implements subcommands.Command.
+func (*capability) Synopsis() string {
+	return "checks if effective capabilities are set/unset"
+}
+
+// Usage implements subcommands.Command.
+func (*capability) Usage() string {
+	return "capability [--enabled=number] [--disabled=number]"
+}
+
+// SetFlags implements subcommands.Command.
+func (c *capability) SetFlags(f *flag.FlagSet) {
+	f.Uint64Var(&c.enabled, "enabled", 0, "")
+	f.Uint64Var(&c.disabled, "disabled", 0, "")
+}
+
+// Execute implements subcommands.Command.
+func (c *capability) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if c.enabled == 0 && c.disabled == 0 {
+		fmt.Println("One of the flags must be set")
+		return subcommands.ExitUsageError
+	}
+
+	status, err := ioutil.ReadFile("/proc/self/status")
+	if err != nil {
+		fmt.Printf("Error reading %q: %v\n", "proc/self/status", err)
+		return subcommands.ExitFailure
+	}
+	re := regexp.MustCompile("CapEff:\t([0-9a-f]+)\n")
+	matches := re.FindStringSubmatch(string(status))
+	if matches == nil || len(matches) != 2 {
+		fmt.Printf("Effective capabilities not found in\n%s\n", status)
+		return subcommands.ExitFailure
+	}
+	caps, err := strconv.ParseUint(matches[1], 16, 64)
+	if err != nil {
+		fmt.Printf("failed to convert capabilities %q: %v\n", matches[1], err)
+		return subcommands.ExitFailure
+	}
+
+	if c.enabled != 0 && (caps&c.enabled) != c.enabled {
+		fmt.Printf("Missing capabilities, want: %#x: got: %#x\n", c.enabled, caps)
+		return subcommands.ExitFailure
+	}
+	if c.disabled != 0 && (caps&c.disabled) != 0 {
+		fmt.Printf("Extra capabilities found, dont_want: %#x: got: %#x\n", c.disabled, caps)
+		return subcommands.ExitFailure
+	}
+
+	return subcommands.ExitSuccess
+}
+
+type ptyRunner struct{}
+
+// Name implements subcommands.Command.
+func (*ptyRunner) Name() string {
+	return "pty-runner"
+}
+
+// Synopsis implements subcommands.Command.
+func (*ptyRunner) Synopsis() string {
+	return "runs the given command with an open pty terminal"
+}
+
+// Usage implements subcommands.Command.
+func (*ptyRunner) Usage() string {
+	return "pty-runner [command]"
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (*ptyRunner) SetFlags(f *flag.FlagSet) {}
+
+// Execute implements subcommands.Command.
+func (*ptyRunner) Execute(_ context.Context, fs *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
+	c := exec.Command(fs.Args()[0], fs.Args()[1:]...)
+	f, err := pty.Start(c)
+	if err != nil {
+		fmt.Printf("pty.Start failed: %v", err)
+		return subcommands.ExitFailure
+	}
+	defer f.Close()
+
+	// Copy stdout from the command to keep this process alive until the
+	// subprocess exits.
+	io.Copy(os.Stdout, f)
+
+	return subcommands.ExitSuccess
+}