captureexe.go RawHistoryFolder

1package wayland
2
3import (
4	"os"
5	"runtime"
6
7	"github.com/bnema/neferwl/internal/adapters/peerexe"
8)
9
10// peerExe names the executable behind a client connection, in two steps so a
11// caller can keep the pidfd and resolve the executable again at each
12// decision.
13type peerExe interface {
14	// Pidfd returns a pidfd of the peer of the connected unix socket sockFD
15	// (SO_PEERPIDFD). It pins the peer process: its pid cannot be recycled
16	// while the file is open. peerexe.ErrNoPidfd means the kernel cannot give
17	// one.
18	Pidfd(sockFD int) (*os.File, error)
19	// Exe returns the path of the executable running as the process behind
20	// pidfd, and its pid. A deleted executable, or a process that has
21	// exited, is an error.
22	Exe(pidfd *os.File) (exe string, pid int, err error)
23}
24
25// linuxPeerExe resolves the peer through a pidfd (SO_PEERPIDFD, Linux 6.5+),
26// with the proof of peerexe.ExeOfPidfd. There is no fallback to the
27// SO_PEERCRED pid: it has no such proof, so a kernel without SO_PEERPIDFD
28// identifies nobody.
29type linuxPeerExe struct {
30	// noPidfd simulates a kernel without SO_PEERPIDFD (tests).
31	noPidfd bool
32}
33
34func (l linuxPeerExe) Pidfd(sockFD int) (*os.File, error) {
35	if l.noPidfd {
36		return nil, peerexe.ErrNoPidfd
37	}
38	return peerexe.Pidfd(sockFD)
39}
40
41func (linuxPeerExe) Exe(pidfd *os.File) (string, int, error) {
42	defer runtime.KeepAlive(pidfd)
43	return peerexe.ExeOfPidfd(int(pidfd.Fd()))
44}