62 lines
1.9 KiB
Go
62 lines
1.9 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"regexp"
|
|
)
|
|
|
|
var hostnameRe = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?$`)
|
|
|
|
func validateHostname(name string) error {
|
|
if !hostnameRe.MatchString(name) {
|
|
return fmt.Errorf("ungültiger Hostname %q (nur Buchstaben, Ziffern, Bindestrich, kein führender/abschließender Bindestrich, keine Domain)", name)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func ip4ToUint32(ip net.IP) uint32 {
|
|
b := ip.To4()
|
|
return uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])
|
|
}
|
|
|
|
// validateIP checks that ip is a valid IPv4 address inside lanCIDR and outside
|
|
// the dynamic DHCP pool [poolStart, poolEnd] (both inclusive), so static
|
|
// reservations can never collide with dynamically leased addresses.
|
|
func validateIP(ip, lanCIDR, poolStart, poolEnd string) error {
|
|
parsed := net.ParseIP(ip)
|
|
if parsed == nil || parsed.To4() == nil {
|
|
return fmt.Errorf("ungültige IPv4-Adresse: %q", ip)
|
|
}
|
|
_, cidr, err := net.ParseCIDR(lanCIDR)
|
|
if err != nil {
|
|
return fmt.Errorf("internes Problem: ungültiges LAN-CIDR %q: %w", lanCIDR, err)
|
|
}
|
|
if !cidr.Contains(parsed) {
|
|
return fmt.Errorf("IP %s liegt nicht im LAN-Netz %s", ip, lanCIDR)
|
|
}
|
|
start := net.ParseIP(poolStart)
|
|
end := net.ParseIP(poolEnd)
|
|
if start == nil || end == nil {
|
|
return fmt.Errorf("internes Problem: ungültiger DHCP-Pool %q-%q", poolStart, poolEnd)
|
|
}
|
|
v, s, e := ip4ToUint32(parsed), ip4ToUint32(start), ip4ToUint32(end)
|
|
if v >= s && v <= e {
|
|
return fmt.Errorf("IP %s liegt im dynamischen DHCP-Pool (%s-%s) und ist für statische Reservierungen gesperrt", ip, poolStart, poolEnd)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// normalizeMAC validates a MAC address and returns it in canonical lower-case
|
|
// colon-separated form. Empty input is accepted and returned as-is.
|
|
func normalizeMAC(mac string) (string, error) {
|
|
if mac == "" {
|
|
return "", nil
|
|
}
|
|
hw, err := net.ParseMAC(mac)
|
|
if err != nil {
|
|
return "", fmt.Errorf("ungültige MAC-Adresse %q: %w", mac, err)
|
|
}
|
|
return hw.String(), nil
|
|
}
|