// Copyright (C) 2016 The Syncthing Authors. // // This Source Code Form is subject to the terms of the Mozilla Public // License, v. 2.0. If a copy of the MPL was not distributed with this file, // You can obtain one at http://mozilla.org/MPL/2.0/. package connections import ( "net" "net/url" "strconv" "strings" "github.com/syncthing/syncthing/lib/osutil" ) func fixupPort(uri *url.URL, defaultPort int) *url.URL { copyURI := *uri host, port, err := net.SplitHostPort(uri.Host) if err != nil && strings.Contains(err.Error(), "missing port") { // addr is on the form "1.2.3.4" or "[fe80::1]" host = uri.Host if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") { // net.JoinHostPort will add the brackets again host = host[1 : len(host)-1] } copyURI.Host = net.JoinHostPort(host, strconv.Itoa(defaultPort)) } else if err == nil && port == "" { // addr is on the form "1.2.3.4:" or "[fe80::1]:" copyURI.Host = net.JoinHostPort(host, strconv.Itoa(defaultPort)) } return ©URI } func getURLsForAllAdaptersIfUnspecified(network string, uri *url.URL) []*url.URL { ip, port, err := resolve(network, uri.Host) // Failed to resolve if err != nil || port == 0 { return nil } // Not an unspecified address, so no point of substituting with local // interface addresses as it's listening on a specific adapter anyway. if len(ip) != 0 && !ip.IsUnspecified() { return nil } hostPorts := getHostPortsForAllAdapters(port) addrs := make([]*url.URL, 0, len(hostPorts)) for _, hostPort := range hostPorts { newUri := *uri newUri.Host = hostPort addrs = append(addrs, &newUri) } return addrs } func getHostPortsForAllAdapters(port int) []string { nets, err := osutil.GetLans() if err != nil { // Ignore failure. return nil } hostPorts := make([]string, 0, len(nets)) 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()) { hostPorts = append(hostPorts, net.JoinHostPort(network.IP.String(), portStr)) } } return hostPorts } func resolve(network, hostPort string) (net.IP, int, error) { switch network { case "tcp", "tcp4", "tcp6": if addr, err := net.ResolveTCPAddr(network, hostPort); err != nil { return net.IPv4zero, 0, err } else { return addr.IP, addr.Port, nil } case "udp", "udp4", "udp6": if addr, err := net.ResolveUDPAddr(network, hostPort); err != nil { return net.IPv4zero, 0, err } else { return addr.IP, addr.Port, nil } case "ip", "ip4", "ip6": if addr, err := net.ResolveIPAddr(network, hostPort); err != nil { return net.IPv4zero, 0, err } else { return addr.IP, 0, nil } } 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 }