go-sandbox/cmd/runprog/main_linux.go

484 lines
12 KiB
Go

// Command runprog executes program defined restricted environment including seccomp-ptraced, namespaced and containerized.
package main
import (
"context"
"errors"
"flag"
"fmt"
"io"
"os"
"os/signal"
"sync/atomic"
"syscall"
"time"
"github.com/criyle/go-sandbox/cmd/runprog/config"
"github.com/criyle/go-sandbox/container"
"github.com/criyle/go-sandbox/pkg/cgroup"
"github.com/criyle/go-sandbox/pkg/forkexec"
"github.com/criyle/go-sandbox/pkg/memfd"
"github.com/criyle/go-sandbox/pkg/mount"
"github.com/criyle/go-sandbox/pkg/rlimit"
"github.com/criyle/go-sandbox/pkg/seccomp"
"github.com/criyle/go-sandbox/pkg/seccomp/libseccomp"
"github.com/criyle/go-sandbox/runner"
"github.com/criyle/go-sandbox/runner/ptrace"
"github.com/criyle/go-sandbox/runner/ptrace/filehandler"
"github.com/criyle/go-sandbox/runner/unshare"
"golang.org/x/sys/unix"
)
var (
addReadable, addWritable, addRawReadable, addRawWritable arrayFlags
allowProc, unsafe, showDetails, useCGroup, memfile, cred, nucg bool
timeLimit, realTimeLimit, memoryLimit, outputLimit, stackLimit uint64
inputFileName, outputFileName, errorFileName, workPath, runt string
useCGroupFd bool
pType, result string
args []string
)
// container init
func init() {
container.Init()
}
func main() {
flag.Usage = printUsage
flag.Uint64Var(&timeLimit, "tl", 1, "Set time limit (in second)")
flag.Uint64Var(&realTimeLimit, "rtl", 0, "Set real time limit (in second)")
flag.Uint64Var(&memoryLimit, "ml", 256, "Set memory limit (in mb)")
flag.Uint64Var(&outputLimit, "ol", 64, "Set output limit (in mb)")
flag.Uint64Var(&stackLimit, "sl", 1024, "Set stack limit (in mb)")
flag.StringVar(&inputFileName, "in", "", "Set input file name")
flag.StringVar(&outputFileName, "out", "", "Set output file name")
flag.StringVar(&errorFileName, "err", "", "Set error file name")
flag.StringVar(&workPath, "work-path", "", "Set the work path of the program")
flag.StringVar(&pType, "type", "default", "Set the program type (for some program such as python)")
flag.StringVar(&result, "res", "stdout", "Set the file name for output the result")
flag.Var(&addReadable, "add-readable", "Add a readable file")
flag.Var(&addWritable, "add-writable", "Add a writable file")
flag.BoolVar(&unsafe, "unsafe", false, "Don't check dangerous syscalls")
flag.BoolVar(&showDetails, "show-trace-details", false, "Show trace details")
flag.BoolVar(&allowProc, "allow-proc", false, "Allow fork, exec... etc.")
flag.Var(&addRawReadable, "add-readable-raw", "Add a readable file (don't transform to its real path)")
flag.Var(&addRawWritable, "add-writable-raw", "Add a writable file (don't transform to its real path)")
flag.BoolVar(&useCGroup, "cgroup", false, "Use cgroup to colloct resource usage")
flag.BoolVar(&useCGroupFd, "cgroupfd", false, "Use cgroup FD to clone3 (cgroup v2 & kernel > 5.7)")
flag.BoolVar(&memfile, "memfd", false, "Use memfd as exec file")
flag.StringVar(&runt, "runner", "ptrace", "Runner for the program (ptrace, ns, container)")
flag.BoolVar(&cred, "cred", false, "Generate credential for containers (uid=10000)")
flag.BoolVar(&nucg, "nucg", false, "don't unshare cgroup")
flag.Parse()
args = flag.Args()
if len(args) == 0 {
printUsage()
}
if realTimeLimit < timeLimit {
realTimeLimit = timeLimit + 2
}
if stackLimit > memoryLimit {
stackLimit = memoryLimit
}
if workPath == "" {
workPath, _ = os.Getwd()
}
var (
f *os.File
err error
)
if result == "stdout" {
f = os.Stdout
} else if result == "stderr" {
f = os.Stderr
} else {
f, err = os.Create(result)
if err != nil {
debug("Failed to open result file:", err)
return
}
defer f.Close()
}
rt, err := start()
if rt == nil {
rt = &runner.Result{
Status: runner.StatusRunnerError,
}
}
if err == nil && rt.Status != runner.StatusNormal {
err = rt.Status
}
debug("setupTime: ", rt.SetUpTime)
debug("runningTime: ", rt.RunningTime)
if err != nil {
debug(err)
c, ok := err.(runner.Status)
if !ok {
c = runner.StatusRunnerError
}
// Handle fatal error from trace
fmt.Fprintf(f, "%d %d %d %d\n", getStatus(c),
int(rt.Time.Round(time.Millisecond)/time.Millisecond), uint64(rt.Memory)>>10, rt.ExitStatus)
if c == runner.StatusRunnerError {
os.Exit(1)
}
} else {
fmt.Fprintf(f, "%d %d %d %d\n", 0,
int(rt.Time.Round(time.Millisecond)/time.Millisecond), uint64(rt.Memory)>>10, rt.ExitStatus)
}
}
type containerRunner struct {
container.Environment
container.ExecveParam
}
func (r *containerRunner) Run(c context.Context) runner.Result {
return r.Environment.Execve(c, r.ExecveParam)
}
func start() (*runner.Result, error) {
var (
r runner.Runner
cg cgroup.Cgroup
cgDir *os.File
cgroupFd uintptr
err error
execFile uintptr
rt runner.Result
)
addRead := filehandler.GetExtraSet(addReadable, addRawReadable)
addWrite := filehandler.GetExtraSet(addWritable, addRawWritable)
args, allow, trace, h := config.GetConf(pType, workPath, args, addRead, addWrite, allowProc)
mb := mount.NewBuilder().
// basic exec and lib
WithBind("/bin", "bin", true).
WithBind("/lib", "lib", true).
WithBind("/lib64", "lib64", true).
WithBind("/usr", "usr", true).
// java wants /proc/self/exe as it need relative path for lib
// however, /proc gives interface like /proc/1/fd/3 ..
// it is fine since open that file will be a EPERM
// changing the fs uid and gid would be a good idea
WithProc().
// some compiler have multiple version
WithBind("/etc/alternatives", "etc/alternatives", true).
// fpc wants /etc/fpc.cfg
WithBind("/etc/fpc.cfg", "etc/fpc.cfg", true).
// go wants /dev/null
WithBind("/dev/null", "dev/null", false).
// ghc wants /var/lib/ghc
WithBind("/var/lib/ghc", "var/lib/ghc", true).
// work dir
WithTmpfs("w", "size=8m,nr_inodes=4k").
// tmp dir
WithTmpfs("tmp", "size=8m,nr_inodes=4k").
FilterNotExist()
mt, err := mb.FilterNotExist().Build()
if err != nil {
return nil, err
}
if useCGroup {
t := cgroup.DetectType()
if t == cgroup.TypeV2 {
cgroup.EnableV2Nesting()
}
ct, err := cgroup.GetAvailableController()
if err != nil {
return nil, err
}
b, err := cgroup.New("runprog", ct)
if err != nil {
return nil, err
}
debug(b)
cg, err = b.Random("runprog")
if err != nil {
return nil, err
}
defer cg.Destroy()
if err = cg.SetMemoryLimit(memoryLimit << 20); err != nil {
return nil, err
}
debug("cgroup:", cg)
if useCGroupFd {
debug("use cgroup fd")
if t != cgroup.TypeV2 {
return nil, fmt.Errorf("use cgroup fd cannot be enabled without cgroup v2")
}
if cgDir, err = cg.Open(); err != nil {
return nil, err
}
defer cgDir.Close()
cgroupFd = cgDir.Fd()
}
}
var syncFunc func(pid int) error
if cg != nil {
syncFunc = func(pid int) error {
if err := cg.AddProc(pid); err != nil {
return err
}
return nil
}
}
if memfile {
fin, err := os.Open(args[0])
if err != nil {
return nil, fmt.Errorf("failed to open args[0]: %w", err)
}
execf, err := memfd.DupToMemfd("run_program", fin)
if err != nil {
return nil, fmt.Errorf("dup to memfd failed: %w", err)
}
fin.Close()
defer execf.Close()
execFile = execf.Fd()
debug("memfd: ", execFile)
}
// open input / output / err files
files, err := prepareFiles(inputFileName, outputFileName, errorFileName)
if err != nil {
return nil, fmt.Errorf("failed to prepare files: %w", err)
}
defer closeFiles(files)
// if not defined, then use the original value
fds := make([]uintptr, len(files))
for i, f := range files {
if f != nil {
fds[i] = f.Fd()
} else {
fds[i] = uintptr(i)
}
}
rlims := rlimit.RLimits{
CPU: timeLimit,
CPUHard: realTimeLimit,
FileSize: outputLimit << 20,
Stack: stackLimit << 20,
Data: memoryLimit << 20,
OpenFile: 256,
DisableCore: true,
}
debug("rlimit: ", rlims)
actionDefault := libseccomp.ActionKill
if showDetails {
actionDefault = libseccomp.ActionTrace
}
if runt != "ptrace" {
allow = append(allow, trace...)
trace = nil
}
builder := libseccomp.Builder{
Allow: allow,
Trace: trace,
Default: actionDefault,
}
// do not build filter for container unsafe since seccomp is not compatible with aarch64 syscalls
var filter seccomp.Filter
if !unsafe || runt != "container" {
filter, err = builder.Build()
if err != nil {
return nil, fmt.Errorf("failed to create seccomp filter: %w", err)
}
}
limit := runner.Limit{
TimeLimit: time.Duration(timeLimit) * time.Second,
MemoryLimit: runner.Size(memoryLimit << 20),
}
if runt == "container" {
var credG container.CredGenerator
if cred {
credG = newCredGen()
}
var stderr io.Writer
if showDetails {
stderr = os.Stderr
}
cloneFlag := forkexec.UnshareFlags
if nucg {
cloneFlag &= ^unix.CLONE_NEWCGROUP
}
b := container.Builder{
TmpRoot: "dm",
Mounts: mb.Mounts,
Stderr: stderr,
CredGenerator: credG,
CloneFlags: uintptr(cloneFlag),
}
m, err := b.Build()
if err != nil {
return nil, fmt.Errorf("failed to new container: %w", err)
}
defer m.Destroy()
err = m.Ping()
if err != nil {
return nil, fmt.Errorf("failed to ping container: %w", err)
}
if unsafe {
filter = nil
}
r = &containerRunner{
Environment: m,
ExecveParam: container.ExecveParam{
Args: args,
Env: []string{pathEnv},
Files: fds,
ExecFile: execFile,
RLimits: rlims.PrepareRLimit(),
Seccomp: filter,
SyncFunc: syncFunc,
CgroupFD: cgroupFd,
SyncAfterExec: cg == nil || cgDir != nil,
},
}
} else if runt == "ns" {
root, err := os.MkdirTemp("", "ns")
if err != nil {
return nil, fmt.Errorf("cannot make temp root for new namespace")
}
defer os.RemoveAll(root)
r = &unshare.Runner{
Args: args,
Env: []string{pathEnv},
ExecFile: execFile,
WorkDir: "/w",
Files: fds,
RLimits: rlims.PrepareRLimit(),
Limit: limit,
Seccomp: filter,
Root: root,
Mounts: mt,
ShowDetails: showDetails,
SyncFunc: syncFunc,
HostName: "run_program",
DomainName: "run_program",
}
} else if runt == "ptrace" {
r = &ptrace.Runner{
Args: args,
Env: []string{pathEnv},
ExecFile: execFile,
WorkDir: workPath,
RLimits: rlims.PrepareRLimit(),
Limit: limit,
Files: fds,
Seccomp: filter,
ShowDetails: showDetails,
Unsafe: unsafe,
Handler: h,
SyncFunc: syncFunc,
}
} else {
return nil, fmt.Errorf("invalid runner type: %s", runt)
}
// gracefully shutdown
sig := make(chan os.Signal, 1)
signal.Notify(sig, os.Interrupt)
// Run tracer
sTime := time.Now()
c, cancel := context.WithTimeout(context.Background(), time.Duration(int64(realTimeLimit)*int64(time.Second)))
defer cancel()
s := make(chan runner.Result, 1)
go func() {
s <- r.Run(c)
}()
rTime := time.Now()
select {
case <-sig:
cancel()
rt = <-s
rt.Status = runner.StatusRunnerError
case rt = <-s:
}
eTime := time.Now()
if rt.SetUpTime == 0 {
rt.SetUpTime = rTime.Sub(sTime)
rt.RunningTime = eTime.Sub(rTime)
}
debug("results:", rt, err)
if useCGroup {
cpu, err := cg.CPUUsage()
if err != nil {
return nil, fmt.Errorf("cgroup cpu: %v", err)
} else {
rt.Time = time.Duration(cpu)
}
// max memory usage may not exist in cgroup v2
memory, err := cg.MemoryMaxUsage()
if err != nil && !errors.Is(err, os.ErrNotExist) {
return nil, fmt.Errorf("cgroup memory: %v", err)
} else if err == nil {
rt.Memory = runner.Size(memory)
}
procPeak, err := cg.ProcessPeak()
if err != nil && !errors.Is(err, os.ErrNotExist) {
return nil, fmt.Errorf("cgroup pid: %v", err)
} else if err == nil {
rt.ProcPeak = procPeak
}
debug("cgroup: cpu: ", cpu, " memory: ", memory, " procPeak: ", procPeak)
debug("cgroup:", rt)
}
if rt.Status == runner.StatusTimeLimitExceeded || rt.Status == runner.StatusNormal {
if rt.Time > limit.TimeLimit {
rt.Status = runner.StatusTimeLimitExceeded
} else {
rt.Status = runner.StatusNormal
}
}
if rt.Status == runner.StatusMemoryLimitExceeded || rt.Status == runner.StatusNormal {
if rt.Memory > limit.MemoryLimit {
rt.Status = runner.StatusMemoryLimitExceeded
} else {
rt.Status = runner.StatusNormal
}
}
return &rt, nil
}
type credGen struct {
cur uint32
}
func newCredGen() *credGen {
return &credGen{cur: 10000}
}
func (c *credGen) Get() syscall.Credential {
n := atomic.AddUint32(&c.cur, 1)
return syscall.Credential{
Uid: n,
Gid: n,
}
}