1 files changed, 236 insertions, 0 deletions
diff --git a/libgo/go/net/ipsock.go b/libgo/go/net/ipsock.go
new file mode 100644
index 000000000..4ba6a55b9
--- /dev/null
+++ b/libgo/go/net/ipsock.go
@@ -0,0 +1,236 @@
+// 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.
+
+// IP sockets
+
+package net
+
+import (
+	"os"
+	"syscall"
+)
+
+// Should we try to use the IPv4 socket interface if we're
+// only dealing with IPv4 sockets?  As long as the host system
+// understands IPv6, it's okay to pass IPv4 addresses to the IPv6
+// interface.  That simplifies our code and is most general.
+// Unfortunately, we need to run on kernels built without IPv6 support too.
+// So probe the kernel to figure it out.
+func kernelSupportsIPv6() bool {
+	// FreeBSD does not support this sort of interface.
+	if syscall.OS == "freebsd" {
+		return false
+	}
+	fd, e := syscall.Socket(syscall.AF_INET6, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
+	if fd >= 0 {
+		closesocket(fd)
+	}
+	return e == 0
+}
+
+var preferIPv4 = !kernelSupportsIPv6()
+
+// TODO(rsc): if syscall.OS == "linux", we're supposd to read
+// /proc/sys/net/core/somaxconn,
+// to take advantage of kernels that have raised the limit.
+func listenBacklog() int { return syscall.SOMAXCONN }
+
+// Internet sockets (TCP, UDP)
+
+// A sockaddr represents a TCP or UDP network address that can
+// be converted into a syscall.Sockaddr.
+type sockaddr interface {
+	Addr
+	sockaddr(family int) (syscall.Sockaddr, os.Error)
+	family() int
+}
+
+func internetSocket(net string, laddr, raddr sockaddr, socktype, proto int, mode string, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err os.Error) {
+	// Figure out IP version.
+	// If network has a suffix like "tcp4", obey it.
+	var oserr os.Error
+	family := syscall.AF_INET6
+	switch net[len(net)-1] {
+	case '4':
+		family = syscall.AF_INET
+	case '6':
+		// nothing to do
+	default:
+		// Otherwise, guess.
+		// If the addresses are IPv4 and we prefer IPv4, use 4; else 6.
+		if preferIPv4 &&
+			(laddr == nil || laddr.family() == syscall.AF_INET) &&
+			(raddr == nil || raddr.family() == syscall.AF_INET) {
+			family = syscall.AF_INET
+		}
+	}
+
+	var la, ra syscall.Sockaddr
+	if laddr != nil {
+		if la, oserr = laddr.sockaddr(family); oserr != nil {
+			goto Error
+		}
+	}
+	if raddr != nil {
+		if ra, oserr = raddr.sockaddr(family); oserr != nil {
+			goto Error
+		}
+	}
+	fd, oserr = socket(net, family, socktype, proto, la, ra, toAddr)
+	if oserr != nil {
+		goto Error
+	}
+	return fd, nil
+
+Error:
+	addr := raddr
+	if mode == "listen" {
+		addr = laddr
+	}
+	return nil, &OpError{mode, net, addr, oserr}
+}
+
+func getip(fd int, remote bool) (ip []byte, port int, ok bool) {
+	// No attempt at error reporting because
+	// there are no possible errors, and the
+	// caller won't report them anyway.
+	var sa syscall.Sockaddr
+	if remote {
+		sa, _ = syscall.Getpeername(fd)
+	} else {
+		sa, _ = syscall.Getsockname(fd)
+	}
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		return sa.Addr[0:], sa.Port, true
+	case *syscall.SockaddrInet6:
+		return sa.Addr[0:], sa.Port, true
+	}
+	return
+}
+
+type InvalidAddrError string
+
+func (e InvalidAddrError) String() string  { return string(e) }
+func (e InvalidAddrError) Timeout() bool   { return false }
+func (e InvalidAddrError) Temporary() bool { return false }
+
+
+func ipToSockaddr(family int, ip IP, port int) (syscall.Sockaddr, os.Error) {
+	switch family {
+	case syscall.AF_INET:
+		if len(ip) == 0 {
+			ip = IPv4zero
+		}
+		if ip = ip.To4(); ip == nil {
+			return nil, InvalidAddrError("non-IPv4 address")
+		}
+		s := new(syscall.SockaddrInet4)
+		for i := 0; i < IPv4len; i++ {
+			s.Addr[i] = ip[i]
+		}
+		s.Port = port
+		return s, nil
+	case syscall.AF_INET6:
+		if len(ip) == 0 {
+			ip = IPzero
+		}
+		// IPv4 callers use 0.0.0.0 to mean "announce on any available address".
+		// In IPv6 mode, Linux treats that as meaning "announce on 0.0.0.0",
+		// which it refuses to do.  Rewrite to the IPv6 all zeros.
+		if p4 := ip.To4(); p4 != nil && p4[0] == 0 && p4[1] == 0 && p4[2] == 0 && p4[3] == 0 {
+			ip = IPzero
+		}
+		if ip = ip.To16(); ip == nil {
+			return nil, InvalidAddrError("non-IPv6 address")
+		}
+		s := new(syscall.SockaddrInet6)
+		for i := 0; i < IPv6len; i++ {
+			s.Addr[i] = ip[i]
+		}
+		s.Port = port
+		return s, nil
+	}
+	return nil, InvalidAddrError("unexpected socket family")
+}
+
+// Split "host:port" into "host" and "port".
+// Host cannot contain colons unless it is bracketed.
+func splitHostPort(hostport string) (host, port string, err os.Error) {
+	// The port starts after the last colon.
+	i := last(hostport, ':')
+	if i < 0 {
+		err = &AddrError{"missing port in address", hostport}
+		return
+	}
+
+	host, port = hostport[0:i], hostport[i+1:]
+
+	// Can put brackets around host ...
+	if len(host) > 0 && host[0] == '[' && host[len(host)-1] == ']' {
+		host = host[1 : len(host)-1]
+	} else {
+		// ... but if there are no brackets, no colons.
+		if byteIndex(host, ':') >= 0 {
+			err = &AddrError{"too many colons in address", hostport}
+			return
+		}
+	}
+	return
+}
+
+// Join "host" and "port" into "host:port".
+// If host contains colons, will join into "[host]:port".
+func joinHostPort(host, port string) string {
+	// If host has colons, have to bracket it.
+	if byteIndex(host, ':') >= 0 {
+		return "[" + host + "]:" + port
+	}
+	return host + ":" + port
+}
+
+// Convert "host:port" into IP address and port.
+func hostPortToIP(net, hostport string) (ip IP, iport int, err os.Error) {
+	host, port, err := splitHostPort(hostport)
+	if err != nil {
+		goto Error
+	}
+
+	var addr IP
+	if host != "" {
+		// Try as an IP address.
+		addr = ParseIP(host)
+		if addr == nil {
+			// Not an IP address.  Try as a DNS name.
+			_, addrs, err1 := LookupHost(host)
+			if err1 != nil {
+				err = err1
+				goto Error
+			}
+			addr = ParseIP(addrs[0])
+			if addr == nil {
+				// should not happen
+				err = &AddrError{"LookupHost returned invalid address", addrs[0]}
+				goto Error
+			}
+		}
+	}
+
+	p, i, ok := dtoi(port, 0)
+	if !ok || i != len(port) {
+		p, err = LookupPort(net, port)
+		if err != nil {
+			goto Error
+		}
+	}
+	if p < 0 || p > 0xFFFF {
+		err = &AddrError{"invalid port", port}
+		goto Error
+	}
+
+	return addr, p, nil
+
+Error:
+	return nil, 0, err
+}