go-sandbox/container/host_exec_linux.go
2025-04-03 23:21:14 +00:00

177 lines
4.5 KiB
Go

package container
import (
"context"
"fmt"
"time"
"github.com/criyle/go-sandbox/pkg/rlimit"
"github.com/criyle/go-sandbox/pkg/seccomp"
"github.com/criyle/go-sandbox/pkg/unixsocket"
"github.com/criyle/go-sandbox/runner"
)
// ExecveParam is parameters to run process inside container
type ExecveParam struct {
// Args holds command line arguments
Args []string
// Env specifies the environment of the process
Env []string
// Files specifies file descriptors for the child process
Files []uintptr
// ExecFile specifies file descriptor for executable file using fexecve
ExecFile uintptr
// CgroupFD specifies file descriptor for cgroup V2
CgroupFD uintptr
// RLimits specifies POSIX Resource limit through setrlimit
RLimits []rlimit.RLimit
// Seccomp specifies seccomp filter
Seccomp seccomp.Filter
// CTTY specifies whether to set controlling TTY
CTTY bool
// SyncFunc calls with pid just before execve (for attach the process to cgroups)
SyncFunc func(pid int) error
// SyncAfterExec makes syncFunc sync after the start of the execution
// Thus, since pid is not guarantee to be exist (may exit early), it is not passed
SyncAfterExec bool
}
// Execve runs process inside container. It accepts context cancellation as time limit exceeded.
func (c *container) Execve(ctx context.Context, param ExecveParam) runner.Result {
c.mu.Lock()
defer c.mu.Unlock()
sTime := time.Now()
// if execve with fd, put fd at the first parameter
var files []int
if param.ExecFile > 0 {
files = append(files, int(param.ExecFile))
}
if param.CgroupFD > 0 {
files = append(files, int(param.CgroupFD))
}
files = append(files, uintptrSliceToInt(param.Files)...)
msg := unixsocket.Msg{
Fds: files,
}
execCmd := &execCmd{
Argv: param.Args,
Env: param.Env,
RLimits: param.RLimits,
Seccomp: param.Seccomp,
FdExec: param.ExecFile > 0,
CTTY: param.CTTY,
SyncAfter: param.SyncAfterExec,
FdCgroup: param.CgroupFD > 0,
}
cm := cmd{
Cmd: cmdExecve,
ExecCmd: execCmd,
}
if err := c.sendCmd(cm, msg); err != nil {
return errResult("execve: sendCmd %v", err)
}
// sync function
rep, msg, err := c.recvReply()
if err != nil {
return errResult("execve: recvReply %v", err)
}
// if sync function did not involved
if rep.Error != nil {
return errResult("execve: %v", rep.Error)
}
// if pid not received
if msg.Cred == nil {
// tell kill function to exit and sync
c.execveSyncKill()
// tell err exec function to exit and sync
c.execveSyncKill()
return errResult("execve: no pid received")
}
if param.SyncFunc != nil {
if err := param.SyncFunc(int(msg.Cred.Pid)); err != nil {
// tell sync function to exit and recv error
c.execveSyncKill()
return errResult("execve: syncfunc failed %v", err)
}
}
// send to syncFunc ack ok
if err := c.sendCmd(cmd{Cmd: cmdOk}, unixsocket.Msg{}); err != nil {
return errResult("execve: ack failed %v", err)
}
// wait for done
return c.waitForDone(ctx, sTime)
}
func (c *container) waitForDone(ctx context.Context, sTime time.Time) runner.Result {
mTime := time.Now()
select {
case <-c.done: // socket error
return convertReplyResult(reply{}, sTime, mTime, c.err)
case <-ctx.Done(): // cancel
c.sendCmd(cmd{Cmd: cmdKill}, unixsocket.Msg{}) // kill
reply, _, err := c.recvReply()
return convertReplyResult(reply, sTime, mTime, err)
case ret := <-c.recvCh: // result
err := c.sendCmd(cmd{Cmd: cmdKill}, unixsocket.Msg{}) // kill
return convertReplyResult(ret.Reply, sTime, mTime, err)
}
}
func convertReplyResult(reply reply, sTime, mTime time.Time, err error) runner.Result {
// handle potential error
if err != nil {
return runner.Result{
Status: runner.StatusRunnerError,
Error: err.Error(),
}
}
if reply.Error != nil {
return runner.Result{
Status: runner.StatusRunnerError,
Error: reply.Error.Error(),
}
}
if reply.ExecReply == nil {
return runner.Result{
Status: runner.StatusRunnerError,
Error: "execve: no reply received",
}
}
// emit result after all communication finish
return runner.Result{
Status: reply.ExecReply.Status,
ExitStatus: reply.ExecReply.ExitStatus,
Time: reply.ExecReply.Time,
Memory: reply.ExecReply.Memory,
SetUpTime: mTime.Sub(sTime),
RunningTime: time.Since(mTime),
}
}
// execveSyncKill will send kill and recv reply
func (c *container) execveSyncKill() {
c.sendCmd(cmd{Cmd: cmdKill}, unixsocket.Msg{})
c.recvReply()
}
func errResult(f string, v ...interface{}) runner.Result {
return runner.Result{
Status: runner.StatusRunnerError,
Error: fmt.Sprintf(f, v...),
}
}