coder/agent/agentssh/portinspection_supported.go

48 lines
1.3 KiB
Go

//go:build linux
package agentssh
import (
"errors"
"fmt"
"os"
"github.com/cakturk/go-netstat/netstat"
"golang.org/x/xerrors"
)
func getListeningPortProcessCmdline(port uint32) (string, error) {
acceptFn := func(s *netstat.SockTabEntry) bool {
return s.LocalAddr != nil && uint32(s.LocalAddr.Port) == port
}
tabs, err := netstat.TCPSocks(acceptFn)
tabs6, err6 := netstat.TCP6Socks(acceptFn)
// Only return the error if the other method found nothing.
if (err != nil && len(tabs6) == 0) || (err6 != nil && len(tabs) == 0) {
return "", xerrors.Errorf("inspect port %d: %w", port, errors.Join(err, err6))
}
var proc *netstat.Process
if len(tabs) > 0 {
proc = tabs[0].Process
} else if len(tabs6) > 0 {
proc = tabs6[0].Process
}
if proc == nil {
// Either nothing is listening on this port or we were unable to read the
// process details (permission issues reading /proc/$pid/* potentially).
// Or, perhaps /proc/net/tcp{,6} is not listing the port for some reason.
return "", nil
}
// The process name provided by go-netstat does not include the full command
// line so grab that instead.
pid := proc.Pid
data, err := os.ReadFile(fmt.Sprintf("/proc/%d/cmdline", pid))
if err != nil {
return "", xerrors.Errorf("read /proc/%d/cmdline: %w", pid, err)
}
return string(data), nil
}