package tcp import ( "fmt" "regexp" "strings" "unicode/utf8" "github.com/go-acme/lego/v4/challenge/tlsalpn01" "github.com/rs/zerolog/log" "github.com/traefik/traefik/v2/pkg/ip" ) var tcpFuncs = map[string]func(*matchersTree, ...string) error{ "ALPN": expect1Parameter(alpn), "ClientIP": expect1Parameter(clientIP), "HostSNI": expect1Parameter(hostSNI), "HostSNIRegexp": expect1Parameter(hostSNIRegexp), } func expect1Parameter(fn func(*matchersTree, ...string) error) func(*matchersTree, ...string) error { return func(route *matchersTree, s ...string) error { if len(s) != 1 { return fmt.Errorf("unexpected number of parameters; got %d, expected 1", len(s)) } return fn(route, s...) } } // alpn checks if any of the connection ALPN protocols matches one of the matcher protocols. func alpn(tree *matchersTree, protos ...string) error { proto := protos[0] if proto == tlsalpn01.ACMETLS1Protocol { return fmt.Errorf("invalid protocol value for ALPN matcher, %q is not allowed", proto) } tree.matcher = func(meta ConnData) bool { for _, alpnProto := range meta.alpnProtos { if alpnProto == proto { return true } } return false } return nil } func clientIP(tree *matchersTree, clientIP ...string) error { checker, err := ip.NewChecker(clientIP) if err != nil { return fmt.Errorf("initializing IP checker for ClientIP matcher: %w", err) } tree.matcher = func(meta ConnData) bool { ok, err := checker.Contains(meta.remoteIP) if err != nil { log.Warn().Err(err).Msg("ClientIP matcher: could not match remote address") return false } return ok } return nil } var almostFQDN = regexp.MustCompile(`^[[:alnum:]\.-]+$`) // hostSNI checks if the SNI Host of the connection match the matcher host. func hostSNI(tree *matchersTree, hosts ...string) error { host := hosts[0] if host == "*" { // Since a HostSNI(`*`) rule has been provided as catchAll for non-TLS TCP, // it allows matching with an empty serverName. tree.matcher = func(meta ConnData) bool { return true } return nil } if !almostFQDN.MatchString(host) { return fmt.Errorf("invalid value for HostSNI matcher, %q is not a valid hostname", host) } tree.matcher = func(meta ConnData) bool { if meta.serverName == "" { return false } if host == meta.serverName { return true } // trim trailing period in case of FQDN host = strings.TrimSuffix(host, ".") return host == meta.serverName } return nil } // hostSNIRegexp checks if the SNI Host of the connection matches the matcher host regexp. func hostSNIRegexp(tree *matchersTree, templates ...string) error { template := templates[0] if !isASCII(template) { return fmt.Errorf("invalid value for HostSNIRegexp matcher, %q is not a valid hostname", template) } re, err := regexp.Compile(template) if err != nil { return fmt.Errorf("compiling HostSNIRegexp matcher: %w", err) } tree.matcher = func(meta ConnData) bool { return re.MatchString(meta.serverName) } return nil } // isASCII checks if the given string contains only ASCII characters. func isASCII(s string) bool { for i := 0; i < len(s); i++ { if s[i] >= utf8.RuneSelf { return false } } return true }