buildx/util/confutil/config_unix.go

61 lines
1.3 KiB
Go

//go:build !windows
// +build !windows
package confutil
import (
"os"
"os/user"
"path/filepath"
"strconv"
"strings"
"syscall"
)
// sudoer returns the user that invoked the current process with sudo only if
// sudo HOME env matches the home directory of the user that ran sudo and is
// part of configDir.
func sudoer(configDir string) *chowner {
if _, ok := os.LookupEnv("SUDO_COMMAND"); !ok {
return nil
}
suidenv := os.Getenv("SUDO_UID") // https://www.sudo.ws/docs/man/sudo.man/#SUDO_UID
sgidenv := os.Getenv("SUDO_GID") // https://www.sudo.ws/docs/man/sudo.man/#SUDO_GID
if suidenv == "" || sgidenv == "" {
return nil
}
u, err := user.LookupId(suidenv)
if err != nil {
return nil
}
suid, err := strconv.Atoi(suidenv)
if err != nil {
return nil
}
sgid, err := strconv.Atoi(sgidenv)
if err != nil {
return nil
}
home, _ := os.UserHomeDir()
if home == "" || u.HomeDir != home {
return nil
}
if ok, _ := isSubPath(home, configDir); !ok {
return nil
}
return &chowner{uid: suid, gid: sgid}
}
func fileOwner(fi os.FileInfo) *chowner {
st := fi.Sys().(*syscall.Stat_t)
return &chowner{uid: int(st.Uid), gid: int(st.Gid)}
}
func isSubPath(basePath, subPath string) (bool, error) {
rel, err := filepath.Rel(basePath, subPath)
if err != nil {
return false, err
}
return !strings.HasPrefix(rel, "..") && rel != ".", nil
}