go-sandbox/deamon/deamon.go
2019-08-04 18:29:25 -07:00

53 lines
1.7 KiB
Go

// Package deamon provides pre-forked container to reduce the container
// create / destroy costs (about 160ms). It creates deamon within unshared
// container and communicate with original process using unix socket with
// oob for fd / pid and structs are encoded in gob format.
package deamon
/*
Protocol between client and deamon (not thread safe):
- copyin (copy file into container):
send: path, perm, <input fd>
reply: "finished" (after copy finished) / "error"
- open (open file inside container):
send: path, flags, perm
reply: "success", <file fd> / "error"
- delete (unlik file / rmdir dir inside container):
send: path
reply: "finished" / "error"
- reset (clean up container for later use (clear workdir / tmp)):
send:
reply: "success"
- execve: (execute file inside container):
send: argv, envv, fd map, rlimits, <fds>
reply:
- success: "success", <pid>
- failed: "failed"
send (success): "init_finished" (as cmd)
- reply: "finished" / send: "kill" (as cmd)
- send: "kill" (as cmd) / reply: "finished"
Any socket related error will cause the deamon exit (with all process inside container)
*/
import (
"github.com/criyle/go-judger/types/rlimit"
)
// Cmd is the control message send into deamon
type Cmd struct {
Cmd string // type of the cmd
Path string // path
Perm int // write perm / open perm
Flags int // open flags
Argv []string // execve argv
Envv []string // execve envv
FdMap []int // execvc fd map
RLmits []rlimit.RLimit // execve posix rlimit
}
// Reply is the reply message send back to controller
type Reply struct {
Error string // empty if no error
}