go-sandbox/daemon/master_cmd_execve.go

102 lines
2.6 KiB
Go

package daemon
import (
"fmt"
"github.com/criyle/go-sandbox/pkg/rlimit"
"github.com/criyle/go-sandbox/pkg/unixsocket"
"github.com/criyle/go-sandbox/types"
)
// ExecveParam is parameters to run process inside container
type ExecveParam struct {
Args []string
Envv []string
Fds []uintptr
// fexecve fd
ExecFile uintptr
// POSIX Resource limit set by set rlimit
RLimits []rlimit.RLimit
// SyncFunc called with pid before execve
SyncFunc func(pid int) error
}
// Execve runs process inside container
// accepts done for cancelation
func (m *Master) Execve(done <-chan struct{}, param *ExecveParam) (<-chan types.Result, error) {
var files []int
if param.ExecFile > 0 {
files = append(files, int(param.ExecFile))
}
files = append(files, uintptrSliceToInt(param.Fds)...)
msg := &unixsocket.Msg{
Fds: files,
}
cmd := Cmd{
Cmd: cmdExecve,
Argv: param.Args,
Envv: param.Envv,
RLmits: param.RLimits,
FdExec: param.ExecFile > 0,
}
if err := m.sendCmd(&cmd, msg); err != nil {
return nil, fmt.Errorf("execve: sendCmd %v", err)
}
reply, msg, err := m.recvReply()
if err != nil {
return nil, fmt.Errorf("execve: recvReply %v", err)
}
if reply.Error != "" || msg == nil || msg.Cred == nil {
m.execveSyncKill()
return nil, fmt.Errorf("execve: no pid recved or error(%v)", reply.Error)
}
if param.SyncFunc != nil {
if err := param.SyncFunc(int(msg.Cred.Pid)); err != nil {
m.execveSyncKill()
return nil, fmt.Errorf("execve: syncfunc failed(%v)", err)
}
}
// send to syncFunc ack ok
if err := m.sendCmd(&Cmd{Cmd: cmdOk}, nil); err != nil {
return nil, fmt.Errorf("execve: ok failed(%v)", err)
}
// make sure goroutine not leaked (blocked) even if result is not consumed
result := make(chan types.Result, 1)
waitDone := make(chan struct{})
// Wait
go func() {
reply2, _, _ := m.recvReply()
close(waitDone)
// done signal (should recv after kill)
m.recvReply()
// emit result after all communication finish
status := reply2.Status
if reply2.Error != "" {
status = types.StatusFatal
}
result <- types.Result{
ExitStatus: reply2.ExitStatus,
Status: status,
Error: reply2.Error,
}
}()
// Kill (if wait is done, a kill message need to be send to collect zombies)
go func() {
select {
case <-done:
case <-waitDone:
}
m.sendCmd(&Cmd{Cmd: cmdKill}, nil)
}()
return result, nil
}
// handleSyncKill will send kill (for sync func), kill (for wait to kill all) and
// then recv error and finish signal when terminated by syncFunc error
func (m *Master) execveSyncKill() {
m.sendCmd(&Cmd{Cmd: cmdKill}, nil)
m.sendCmd(&Cmd{Cmd: cmdKill}, nil)
m.recvReply()
m.recvReply()
}