From 467522d04d9e0f941c618dc7bd25e674b6638f9a Mon Sep 17 00:00:00 2001 From: bt90 Date: Wed, 23 Aug 2023 12:28:48 +0200 Subject: [PATCH] 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 --- lib/connections/util.go | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) diff --git a/lib/connections/util.go b/lib/connections/util.go index 3dd5dc92c..7f6c3fd60 100644 --- a/lib/connections/util.go +++ b/lib/connections/util.go @@ -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