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lib/connections: Allow IPv6 ULA in discovery announcements (fixes #7456) (#9048) 

The allowed IPv4 ranges are the same as before. But we now also accept IPv6 addresses in the ULA range FC00::/7. These addresses don't require an interface identifier and are roughly equivalent to the IPv4 private ranges.

Typical usecases:

VPN interface IPs: Wireguard, OpenVPN, Tailscale, ...
fixed IPv6 LAN addressing while the provider assigns a dynamic prefix. e.g used by pihole
https://cs.opensource.google/go/go/+/refs/tags/go1.21.0:src/net/ip.go;l=146
This commit is contained in:
bt90 2023-08-23 12:28:48 +02:00 committed by GitHub
parent 3147285c60
commit 467522d04d
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 3 additions and 17 deletions
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20
lib/connections/util.go
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@ -71,12 +71,9 @@ func getHostPortsForAllAdapters(port int) []string {
portStr := strconv.Itoa(port)
for _, network := range nets {
// Only IPv4 addresses, as v6 link local require an interface identifiers to work correctly
// And non link local in theory are globally routable anyway.
if network.IP.To4() == nil {
continue
}
if network.IP.IsLinkLocalUnicast() || (isV4Local(network.IP) && network.IP.IsGlobalUnicast()) {
// Only accept IPv4 link-local unicast and the private ranges defined in RFC 1918 and RFC 4193
// IPv6 link-local addresses require an interface identifier to work correctly
if (network.IP.To4() != nil && network.IP.IsLinkLocalUnicast()) || network.IP.IsPrivate() {
hostPorts = append(hostPorts, net.JoinHostPort(network.IP.String(), portStr))
}
}
@ -107,17 +104,6 @@ func resolve(network, hostPort string) (net.IP, int, error) {
return net.IPv4zero, 0, net.UnknownNetworkError(network)
}
func isV4Local(ip net.IP) bool {
// See https://go-review.googlesource.com/c/go/+/162998/
// We only take the V4 part of that.
if ip4 := ip.To4(); ip4 != nil {
return ip4[0] == 10 ||
(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
(ip4[0] == 192 && ip4[1] == 168)
}
return false
}
func maybeReplacePort(uri *url.URL, laddr net.Addr) *url.URL {
if laddr == nil {
return uri