Add support for net.IP

ipsock.go

@@ -0,0 +1,98 @@
+// The following is copied from Go 1.16 official implementation.
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+import "internal/bytealg"
+
+// SplitHostPort splits a network address of the form "host:port",
+// "host%zone:port", "[host]:port" or "[host%zone]:port" into host or
+// host%zone and port.
+//
+// A literal IPv6 address in hostport must be enclosed in square
+// brackets, as in "[::1]:80", "[::1%lo0]:80".
+//
+// See func Dial for a description of the hostport parameter, and host
+// and port results.
+func SplitHostPort(hostport string) (host, port string, err error) {
+	const (
+		missingPort   = "missing port in address"
+		tooManyColons = "too many colons in address"
+	)
+	addrErr := func(addr, why string) (host, port string, err error) {
+		return "", "", &AddrError{Err: why, Addr: addr}
+	}
+	j, k := 0, 0
+
+	// The port starts after the last colon.
+	i := last(hostport, ':')
+	if i < 0 {
+		return addrErr(hostport, missingPort)
+	}
+
+	if hostport[0] == '[' {
+		// Expect the first ']' just before the last ':'.
+		end := bytealg.IndexByteString(hostport, ']')
+		if end < 0 {
+			return addrErr(hostport, "missing ']' in address")
+		}
+		switch end + 1 {
+		case len(hostport):
+			// There can't be a ':' behind the ']' now.
+			return addrErr(hostport, missingPort)
+		case i:
+			// The expected result.
+		default:
+			// Either ']' isn't followed by a colon, or it is
+			// followed by a colon that is not the last one.
+			if hostport[end+1] == ':' {
+				return addrErr(hostport, tooManyColons)
+			}
+			return addrErr(hostport, missingPort)
+		}
+		host = hostport[1:end]
+		j, k = 1, end+1 // there can't be a '[' resp. ']' before these positions
+	} else {
+		host = hostport[:i]
+		if bytealg.IndexByteString(host, ':') >= 0 {
+			return addrErr(hostport, tooManyColons)
+		}
+	}
+	if bytealg.IndexByteString(hostport[j:], '[') >= 0 {
+		return addrErr(hostport, "unexpected '[' in address")
+	}
+	if bytealg.IndexByteString(hostport[k:], ']') >= 0 {
+		return addrErr(hostport, "unexpected ']' in address")
+	}
+
+	port = hostport[i+1:]
+	return host, port, nil
+}
+
+func splitHostZone(s string) (host, zone string) {
+	// The IPv6 scoped addressing zone identifier starts after the
+	// last percent sign.
+	if i := last(s, '%'); i > 0 {
+		host, zone = s[:i], s[i+1:]
+	} else {
+		host = s
+	}
+	return
+}
+
+// JoinHostPort combines host and port into a network address of the
+// form "host:port". If host contains a colon, as found in literal
+// IPv6 addresses, then JoinHostPort returns "[host]:port".
+//
+// See func Dial for a description of the host and port parameters.
+func JoinHostPort(host, port string) string {
+	// We assume that host is a literal IPv6 address if host has
+	// colons.
+	if bytealg.IndexByteString(host, ':') >= 0 {
+		return "[" + host + "]:" + port
+	}
+	return host + ":" + port
+}