vm/vmm: support for vmm found on OpenBSD (#678)

vm/vmm: add vmm implementation found on OpenBSD

1 files changed, 376 insertions, 0 deletions

diff --git a/vm/vmm/vmm.go b/vm/vmm/vmm.go
new file mode 100644
index 000000000..acaf9b3b2
--- /dev/null
+++ b/vm/vmm/vmm.go
@@ -0,0 +1,376 @@
+// Copyright 2018 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// Package vmm provides VMs based on OpenBSD vmm virtualization.
+package vmm
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/google/syzkaller/pkg/config"
+	"github.com/google/syzkaller/pkg/log"
+	"github.com/google/syzkaller/pkg/osutil"
+	"github.com/google/syzkaller/vm/vmimpl"
+)
+
+func init() {
+	vmimpl.Register("vmm", ctor)
+}
+
+type Config struct {
+	Count    int    `json:"count"`    // number of VMs to use
+	CPU      int    `json:"cpu"`      // number of VM CPUs
+	Mem      int    `json:"mem"`      // amount of VM memory in MBs
+	Kernel   string `json:"kernel"`   // kernel to boot
+	Template string `json:"template"` // vm template
+}
+
+type Pool struct {
+	env *vmimpl.Env
+	cfg *Config
+}
+
+type instance struct {
+	cfg      *Config
+	index    int
+	image    string
+	debug    bool
+	os       string
+	workdir  string
+	sshkey   string
+	sshuser  string
+	sshhost  string
+	sshport  int
+	merger   *vmimpl.OutputMerger
+	vmID     int
+	stop     chan bool
+	diagnose chan string
+}
+
+func ctor(env *vmimpl.Env) (vmimpl.Pool, error) {
+	cfg := &Config{
+		Count: 1,
+		CPU:   1,
+		Mem:   512,
+	}
+
+	if !osutil.IsExist(env.Image) {
+		return nil, fmt.Errorf("image file '%v' does not exist", env.Image)
+	}
+
+	if err := config.LoadData(env.Config, cfg); err != nil {
+		return nil, fmt.Errorf("failed to parse vmm vm config: %v", err)
+	}
+	if cfg.Count < 1 || cfg.Count > 8 {
+		return nil, fmt.Errorf("invalid config param count: %v, want [1-8]", cfg.Count)
+	}
+	if env.Debug {
+		cfg.Count = 1
+	}
+	if cfg.CPU > 1 {
+		return nil, fmt.Errorf("invalid config param cpu: %v, want 1", cfg.CPU)
+	}
+	if cfg.Mem < 128 || cfg.Mem > 1048576 {
+		return nil, fmt.Errorf("invalid config param mem: %v, want [128-1048576]", cfg.Mem)
+	}
+	if cfg.Kernel == "" {
+		return nil, fmt.Errorf("missing config param kernel")
+	}
+	if !osutil.IsExist(cfg.Kernel) {
+		return nil, fmt.Errorf("kernel '%v' does not exist", cfg.Kernel)
+	}
+	if cfg.Template == "" {
+		return nil, fmt.Errorf("missing config param template")
+	}
+	pool := &Pool{
+		cfg: cfg,
+		env: env,
+	}
+
+	return pool, nil
+}
+
+func (pool *Pool) Count() int {
+	return pool.cfg.Count
+}
+
+func (pool *Pool) Create(workdir string, index int) (vmimpl.Instance, error) {
+	image := filepath.Join(workdir, "disk.img")
+	if err := osutil.CopyFile(pool.env.Image, image); err != nil {
+		return nil, err
+	}
+
+	inst := &instance{
+		cfg:      pool.cfg,
+		index:    index,
+		image:    image,
+		debug:    pool.env.Debug,
+		os:       pool.env.OS,
+		workdir:  workdir,
+		sshkey:   pool.env.SSHKey,
+		sshuser:  pool.env.SSHUser,
+		sshport:  22,
+		stop:     make(chan bool),
+		diagnose: make(chan string),
+	}
+	closeInst := inst
+	defer func() {
+		if closeInst != nil {
+			closeInst.Close()
+		}
+	}()
+
+	if err := inst.Boot(); err != nil {
+		return nil, err
+	}
+
+	closeInst = nil
+	return inst, nil
+}
+
+func (inst *instance) Boot() error {
+	name := fmt.Sprintf("syzkaller-%v", inst.index)
+	mem := fmt.Sprintf("%vM", inst.cfg.Mem)
+	startArgs := []string{
+		"start", name,
+		"-t", inst.cfg.Template,
+		"-b", inst.cfg.Kernel,
+		"-d", inst.image,
+		"-m", mem,
+	}
+	startOut, err := inst.vmctl(startArgs...)
+	if err != nil {
+		return err
+	}
+
+	inst.vmID, err = parseID(startOut)
+	if err != nil {
+		return err
+	}
+	inst.sshhost = fmt.Sprintf("100.64.%v.3", inst.vmID)
+
+	var tee io.Writer
+	if inst.debug {
+		tee = os.Stdout
+	}
+	inst.merger = vmimpl.NewOutputMerger(tee)
+
+	if err := inst.console(); err != nil {
+		return err
+	}
+
+	var bootOutput []byte
+	bootOutputStop := make(chan bool)
+	go func() {
+		for {
+			select {
+			case out := <-inst.merger.Output:
+				bootOutput = append(bootOutput, out...)
+			case <-bootOutputStop:
+				bootOutputStop <- true
+				return
+			}
+		}
+	}()
+
+	if err := vmimpl.WaitForSSH(inst.debug, 2*time.Minute, inst.sshhost,
+		inst.sshkey, inst.sshuser, inst.os, inst.sshport); err != nil {
+		bootOutputStop <- true
+		<-bootOutputStop
+		return vmimpl.BootError{Title: err.Error(), Output: bootOutput}
+	}
+	bootOutputStop <- true
+	return nil
+}
+
+func (inst *instance) Close() {
+	inst.vmctl("stop", inst.vmIdent(), "-f")
+}
+
+func (inst *instance) Forward(port int) (string, error) {
+	addr := fmt.Sprintf("100.64.%v.2:%v", inst.vmID, port)
+	return addr, nil
+}
+
+func (inst *instance) Copy(hostSrc string) (string, error) {
+	vmDst := filepath.Join("/root", filepath.Base(hostSrc))
+	args := append(vmimpl.SCPArgs(inst.debug, inst.sshkey, inst.sshport),
+		hostSrc, inst.sshuser+"@"+inst.sshhost+":"+vmDst)
+	if inst.debug {
+		log.Logf(0, "running command: scp %#v", args)
+	}
+	_, err := osutil.RunCmd(3*time.Minute, "", "scp", args...)
+	if err != nil {
+		return "", err
+	}
+	return vmDst, nil
+}
+
+func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command string) (
+	<-chan []byte, <-chan error, error) {
+	rpipe, wpipe, err := osutil.LongPipe()
+	if err != nil {
+		return nil, nil, err
+	}
+	inst.merger.Add("ssh", rpipe)
+
+	args := append(vmimpl.SSHArgs(inst.debug, inst.sshkey, inst.sshport),
+		inst.sshuser+"@"+inst.sshhost, command)
+	if inst.debug {
+		log.Logf(0, "running command: ssh %#v", args)
+	}
+	cmd := osutil.Command("ssh", args...)
+	cmd.Stdout = wpipe
+	cmd.Stderr = wpipe
+	if err := cmd.Start(); err != nil {
+		wpipe.Close()
+		return nil, nil, err
+	}
+	wpipe.Close()
+	errc := make(chan error, 1)
+	signal := func(err error) {
+		select {
+		case errc <- err:
+		default:
+		}
+	}
+
+	go func() {
+		select {
+		case <-time.After(timeout):
+			signal(vmimpl.ErrTimeout)
+		case <-stop:
+			signal(vmimpl.ErrTimeout)
+		case err := <-inst.merger.Err:
+			cmd.Process.Kill()
+			inst.stop <- true
+			inst.merger.Wait()
+			if cmdErr := cmd.Wait(); cmdErr == nil {
+				// If the command exited successfully, we got EOF error from merger.
+				// But in this case no error has happened and the EOF is expected.
+				err = nil
+			}
+
+			signal(err)
+			return
+		}
+		cmd.Process.Kill()
+		inst.stop <- true
+		inst.merger.Wait()
+		cmd.Wait()
+	}()
+	return inst.merger.Output, errc, nil
+}
+
+func (inst *instance) Diagnose() bool {
+	commands := []string{"", "trace", "show registers"}
+	for _, c := range commands {
+		select {
+		case inst.diagnose <- c:
+		case <-time.After(2 * time.Second):
+		}
+	}
+	return true
+}
+
+func (inst *instance) console() error {
+	outr, outw, err := osutil.LongPipe()
+	if err != nil {
+		return err
+	}
+	inr, inw, err := osutil.LongPipe()
+	if err != nil {
+		return err
+	}
+
+	cmd := osutil.Command("vmctl", "console", inst.vmIdent())
+	cmd.Stdin = inr
+	cmd.Stdout = outw
+	cmd.Stderr = outw
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+	outw.Close()
+	inr.Close()
+	inst.merger.Add("console", outr)
+
+	go func() {
+		stopDiagnose := make(chan bool)
+		go func() {
+			for {
+				select {
+				case s := <-inst.diagnose:
+					inw.Write([]byte(s + "\n"))
+					time.Sleep(1 * time.Second)
+				case <-stopDiagnose:
+					return
+				}
+			}
+		}()
+
+		stopProcess := make(chan bool)
+		go func() {
+			select {
+			case <-inst.stop:
+				cmd.Process.Kill()
+			case <-stopProcess:
+			}
+		}()
+
+		_, err = cmd.Process.Wait()
+		inw.Close()
+		outr.Close()
+		stopDiagnose <- true
+		stopProcess <- true
+	}()
+
+	return nil
+}
+
+// Run the given vmctl(8) command and wait for it to finish.
+func (inst *instance) vmctl(args ...string) (string, error) {
+	if inst.debug {
+		log.Logf(0, "running command: vmctl %#v", args)
+	}
+	out, err := osutil.RunCmd(10*time.Second, "", "vmctl", args...)
+	if err != nil {
+		if inst.debug {
+			log.Logf(0, "vmctl failed: %v", err)
+		}
+		return "", err
+	}
+	if inst.debug {
+		log.Logf(0, "vmctl output: %v", string(out))
+	}
+	return string(out), nil
+}
+
+func (inst *instance) vmIdent() string {
+	return strconv.Itoa(inst.vmID)
+}
+
+// Extract VM ID from vmctl start output.
+func parseID(str string) (int, error) {
+	const prefix = "vmctl: started vm "
+	if !strings.HasPrefix(str, prefix) {
+		return 0, fmt.Errorf("could not extract ID from: %v", str)
+	}
+	fields := strings.Fields(str)
+	if len(fields) < 4 {
+		return 0, fmt.Errorf("could not extract ID from: %v", str)
+	}
+	i, err := strconv.Atoi(fields[3])
+	if err != nil {
+		return 0, err
+	}
+	if i <= 0 {
+		return 0, fmt.Errorf("invalid ID: %v", i)
+	}
+	return i, nil
+}