69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
package routing
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import (
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"errors"
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"fmt"
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"net"
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"github.com/qdm12/gluetun/internal/netlink"
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)
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func IPIsPrivate(ip net.IP) bool {
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return ip.IsPrivate() || ip.IsLoopback() ||
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ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast()
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}
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var (
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errInterfaceIPNotFound = errors.New("IP address not found for interface")
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)
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func ipMatchesFamily(ip net.IP, family int) bool {
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return (family == netlink.FAMILY_V6 && ip.To4() == nil) ||
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(family == netlink.FAMILY_V4 && ip.To4() != nil)
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}
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func ensureNoIPv6WrappedIPv4(candidateIP net.IP) (resultIP net.IP) {
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const ipv4Size = 4
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if candidateIP.To4() == nil || len(candidateIP) == ipv4Size { // ipv6 or ipv4
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return candidateIP
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}
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// ipv6-wrapped ipv4
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resultIP = make(net.IP, ipv4Size)
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copy(resultIP, candidateIP[12:16])
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return resultIP
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}
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func (r *Routing) assignedIP(interfaceName string, family int) (ip net.IP, err error) {
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iface, err := net.InterfaceByName(interfaceName)
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if err != nil {
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return nil, fmt.Errorf("network interface %s not found: %w", interfaceName, err)
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}
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addresses, err := iface.Addrs()
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if err != nil {
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return nil, fmt.Errorf("listing interface %s addresses: %w", interfaceName, err)
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}
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for _, address := range addresses {
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switch value := address.(type) {
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case *net.IPAddr:
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ip = value.IP
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case *net.IPNet:
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ip = value.IP
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default:
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continue
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}
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if !ipMatchesFamily(ip, family) {
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continue
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}
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// Ensure we don't return an IPv6-wrapped IPv4 address
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// since netip.Address String method works differently than
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// net.IP String method for this kind of addresses.
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ip = ensureNoIPv6WrappedIPv4(ip)
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return ip, nil
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}
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return nil, fmt.Errorf("%w: interface %s in %d addresses",
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errInterfaceIPNotFound, interfaceName, len(addresses))
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}
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