mdouchement
commented
5 months ago Some POC code used to inject host binary stdout & stderr instead of Golang's default ones:
package runner
import (
"fmt"
"io"
"os"
osexec "os/exec"
"syscall"
tengopkg "github.com/d5/tengo/v2"
"github.com/d5/tengo/v2/stdlib"
"github.com/mdouchement/ldt/pkg/tengolib"
"github.com/mdouchement/logger"
"github.com/pkg/errors"
)
func withfmt(modules *tengopkg.ModuleMap, w io.Writer) {
m := modules.GetBuiltinModule("fmt")
// Overwrite useful methods defined in v2.16.1
m.Attrs["print"] = &tengopkg.UserFunction{
Name: "print",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) < 1 {
return nil, tengopkg.ErrWrongNumArguments
}
fmt.Fprint(w, tengolib.InterfaceArray(args)...)
return tengopkg.UndefinedValue, nil
},
}
m.Attrs["printf"] = &tengopkg.UserFunction{
Name: "printf",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) < 2 {
return nil, tengopkg.ErrWrongNumArguments
}
str, err := tengolib.Format(args...)
if err != nil {
return nil, err
}
fmt.Fprint(w, str)
return tengopkg.UndefinedValue, nil
},
}
m.Attrs["println"] = &tengopkg.UserFunction{
Name: "println",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) < 1 {
return nil, tengopkg.ErrWrongNumArguments
}
fmt.Fprintln(w, tengolib.InterfaceArray(args)...)
return tengopkg.UndefinedValue, nil
},
}
}
func withexec(modules *tengopkg.ModuleMap, dir string, env map[string]string, wout io.Writer, werr io.Writer) {
m := modules.GetBuiltinModule("os")
// Overwrite useful methods defined in v2.16.1
m.Attrs["exec"] = &tengopkg.UserFunction{
Name: "exec",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) == 0 {
return nil, tengopkg.ErrWrongNumArguments
}
bin, ok := tengopkg.ToString(args[0])
if !ok {
return nil, tengopkg.ErrInvalidArgumentType{
Name: "first",
Expected: "string(compatible)",
Found: args[0].TypeName(),
}
}
bin, err := osexec.LookPath(bin)
if err != nil {
return tengolib.WrapError(err), nil
}
arguments := make([]string, 0, len(args)-1)
for idx, arg := range args[1:] {
execArg, ok := tengopkg.ToString(arg)
if !ok {
return nil, tengopkg.ErrInvalidArgumentType{
Name: fmt.Sprintf("args[%d]", idx),
Expected: "string(compatible)",
Found: args[1+idx].TypeName(),
}
}
arguments = append(arguments, execArg)
}
cmd := &osexec.Cmd{
Path: bin,
Args: arguments,
Dir: dir,
}
if wout != nil {
cmd.Stdout = wout
}
if werr != nil {
cmd.Stderr = werr
}
for k, v := range env {
cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", k, v))
}
fmt.Printf("%#v\n", cmd)
return makeOSExecCommand(cmd), nil
},
}
}
func makeOSExecCommand(cmd *osexec.Cmd) *tengopkg.ImmutableMap {
return &tengopkg.ImmutableMap{
Value: map[string]tengopkg.Object{
// combined_output() => bytes/error
"combined_output": &tengopkg.UserFunction{
Name: "combined_output",
Value: stdlib.FuncARYE(cmd.CombinedOutput),
},
// output() => bytes/error
"output": &tengopkg.UserFunction{
Name: "output",
Value: stdlib.FuncARYE(cmd.Output),
}, //
// run() => error
"run": &tengopkg.UserFunction{
Name: "run",
Value: stdlib.FuncARE(cmd.Run),
}, //
// start() => error
"start": &tengopkg.UserFunction{
Name: "start",
Value: stdlib.FuncARE(cmd.Start),
}, //
// wait() => error
"wait": &tengopkg.UserFunction{
Name: "wait",
Value: stdlib.FuncARE(cmd.Wait),
}, //
// set_path(path string)
"set_path": &tengopkg.UserFunction{
Name: "set_path",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 1 {
return nil, tengopkg.ErrWrongNumArguments
}
s1, ok := tengopkg.ToString(args[0])
if !ok {
return nil, tengopkg.ErrInvalidArgumentType{
Name: "first",
Expected: "string(compatible)",
Found: args[0].TypeName(),
}
}
cmd.Path = s1
return tengopkg.UndefinedValue, nil
},
},
// set_dir(dir string)
"set_dir": &tengopkg.UserFunction{
Name: "set_dir",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 1 {
return nil, tengopkg.ErrWrongNumArguments
}
s1, ok := tengopkg.ToString(args[0])
if !ok {
return nil, tengopkg.ErrInvalidArgumentType{
Name: "first",
Expected: "string(compatible)",
Found: args[0].TypeName(),
}
}
cmd.Dir = s1
return tengopkg.UndefinedValue, nil
},
},
// set_env(env array(string))
"set_env": &tengopkg.UserFunction{
Name: "set_env",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 1 {
return nil, tengopkg.ErrWrongNumArguments
}
var env []string
var err error
switch arg0 := args[0].(type) {
case *tengopkg.Array:
env, err = tengolib.StringArray(arg0.Value, "first")
if err != nil {
return nil, err
}
case *tengopkg.ImmutableArray:
env, err = tengolib.StringArray(arg0.Value, "first")
if err != nil {
return nil, err
}
default:
return nil, tengopkg.ErrInvalidArgumentType{
Name: "first",
Expected: "array",
Found: arg0.TypeName(),
}
}
cmd.Env = append(cmd.Env, env...) // Custom modification behavior
return tengopkg.UndefinedValue, nil
},
},
// process() => imap(process)
"process": &tengopkg.UserFunction{
Name: "process",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 0 {
return nil, tengopkg.ErrWrongNumArguments
}
return makeOSProcess(cmd.Process), nil
},
},
},
}
}
func makeOSProcess(proc *os.Process) *tengopkg.ImmutableMap {
return &tengopkg.ImmutableMap{
Value: map[string]tengopkg.Object{
"kill": &tengopkg.UserFunction{
Name: "kill",
Value: stdlib.FuncARE(proc.Kill),
},
"release": &tengopkg.UserFunction{
Name: "release",
Value: stdlib.FuncARE(proc.Release),
},
"signal": &tengopkg.UserFunction{
Name: "signal",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 1 {
return nil, tengopkg.ErrWrongNumArguments
}
i1, ok := tengopkg.ToInt64(args[0])
if !ok {
return nil, tengopkg.ErrInvalidArgumentType{
Name: "first",
Expected: "int(compatible)",
Found: args[0].TypeName(),
}
}
return tengolib.WrapError(proc.Signal(syscall.Signal(i1))), nil
},
},
"wait": &tengopkg.UserFunction{
Name: "wait",
Value: func(args ...tengopkg.Object) (tengopkg.Object, error) {
if len(args) != 0 {
return nil, tengopkg.ErrWrongNumArguments
}
state, err := proc.Wait()
if err != nil {
return tengolib.WrapError(err), nil
}
return makeOSProcessState(state), nil
},
},
},
}
}
func makeOSProcessState(state *os.ProcessState) *tengopkg.ImmutableMap {
return &tengopkg.ImmutableMap{
Value: map[string]tengopkg.Object{
"exited": &tengopkg.UserFunction{
Name: "exited",
Value: stdlib.FuncARB(state.Exited),
},
"pid": &tengopkg.UserFunction{
Name: "pid",
Value: stdlib.FuncARI(state.Pid),
},
"string": &tengopkg.UserFunction{
Name: "string",
Value: stdlib.FuncARS(state.String),
},
"success": &tengopkg.UserFunction{
Name: "success",
Value: stdlib.FuncARB(state.Success),
},
},
}
}
Add the following features:
shigoto.set_local_variable(k, v)variablesshigoto.set_global_variable(k, v)variables(the ones defined at the root of the YAML file)shigoto.set_local_env(k, v)environmentshigoto.set_global_env(k, v)environment(the ones defined at the root of the YAML file)shigoto.stdoutwhich provides:write(bytes) => int/errorread(bytes) => int/errorshigoto.stderrset_stdout()&set_stderrto https://github.com/d5/tengo/blob/master/docs/stdlib-os.md#command