preliminary network - just Dial for now

R=r,presotto
OCL=15393
CL=15399

6 files changed, 1474 insertions, 0 deletions

diff --git a/src/lib/net/Makefile b/src/lib/net/Makefile
new file mode 100644
index 000000000..5d0802173
--- /dev/null
+++ b/src/lib/net/Makefile
@@ -0,0 +1,44 @@
+# 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.
+
+O=6
+GC=$(O)g
+AS=$(O)a
+
+NET=$(GOROOT)/pkg/net.a
+SOCKET=$(GOROOT)/pkg/socket.a
+IP=$(GOROOT)/pkg/ip.$O
+
+NETO=\
+	net.$O\
+
+SOCKETO=\
+	cvt.$O\
+	socket_$(GOOS).$O\
+
+$(NET): $(NETO)
+	$(O)ar grc $(NET) $(NETO)
+
+$(NETO): $(IP) $(SOCKET)
+
+$(SOCKET): $(SOCKETO)
+	$(O)ar grc $(SOCKET) $(SOCKETO)
+
+$(GOROOT)/pkg/%.$O: %.$O
+	cp $*.$O $(GOROOT)/pkg/$*.$O
+	rm $*.$O
+
+install: nuke $(IP) $(SOCKET) $(NET)
+
+nuke:
+	rm -f *.$O *.a $(IP) $(NET)
+
+clean:
+	rm -f *.$O *.a
+
+%.$O:	%.go
+	$(GC) $<
+
+%.$O:	%.s
+	$(AS) $<
diff --git a/src/lib/net/cvt.s b/src/lib/net/cvt.s
new file mode 100644
index 000000000..920f52351
--- /dev/null
+++ b/src/lib/net/cvt.s
@@ -0,0 +1,38 @@
+// 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.
+
+// Type-unsafe casts.
+
+TEXT socket·SockaddrPtr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·Int32Ptr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·LingerPtr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT	socket·TimevalPtr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·SockaddrInet4ToSockaddr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·SockaddrToSockaddrInet4(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·SockaddrInet6ToSockaddr(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
+TEXT socket·SockaddrToSockaddrInet6(SB),7,$0
+	MOVQ	8(SP), AX
+	MOVQ	AX, 16(SP)
+	RET
diff --git a/src/lib/net/ip.go b/src/lib/net/ip.go
new file mode 100644
index 000000000..ddb5114c5
--- /dev/null
+++ b/src/lib/net/ip.go
@@ -0,0 +1,431 @@
+// 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 address manipulations
+//
+// IPv4 addresses are 4 bytes; IPv6 addresses are 16 bytes.
+// An IPv4 address can be converted to an IPv6 address by
+// adding a canonical prefix (10 zeros, 2 0xFFs).
+// This library accepts either size of byte array but always
+// returns 16-byte addresses.
+
+package ip
+
+export const (
+	IPv4len = 4;
+	IPv6len = 16
+)
+
+// Make the 4 bytes into an IPv4 address (in IPv6 form)
+func MakeIPv4(a, b, c, d byte) *[]byte {
+	p := new([]byte, IPv6len)
+	for i := 0; i < 10; i++ {
+		p[i] = 0
+	}
+	p[10] = 0xff;
+	p[11] = 0xff;
+	p[12] = a;
+	p[13] = b;
+	p[14] = c;
+	p[15] = d
+	return p
+}
+
+// Well-known IP addresses
+export var IPv4bcast, IPv4allsys, IPv4allrouter, IPv4prefix, IPallbits, IPnoaddr *[]byte
+
+func init() {
+	IPv4bcast = MakeIPv4(0xff, 0xff, 0xff, 0xff);
+	IPv4allsys = MakeIPv4(0xe0, 0x00, 0x00, 0x01);
+	IPv4allrouter = MakeIPv4(0xe0, 0x00, 0x00, 0x02);
+	IPv4prefix = MakeIPv4(0, 0, 0, 0);
+	IPallbits = new([]byte, IPv6len);
+	for i := 0; i < IPv6len; i++ {
+		IPallbits[i] = 0xff
+	}
+	IPnoaddr = new([]byte, IPv6len);	// zeroed
+}
+
+// Is p all zeros?
+func IsZeros(p *[]byte) bool {
+	for i := 0; i < len(p); i++ {
+		if p[i] != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+// Is p an IPv4 address (perhaps in IPv6 form)?
+// If so, return the 4-byte V4 array.
+export func ToIPv4(p *[]byte) *[]byte {
+	if len(p) == IPv4len {
+		return p
+	}
+	if len(p) == IPv6len
+	&& IsZeros(p[0:10])
+	&& p[10] == 0xff
+	&& p[11] == 0xff {
+		return p[12:16]
+	}
+	return nil
+}
+
+// Convert p to IPv6 form.
+export func ToIPv6(p *[]byte) *[]byte {
+	if len(p) == IPv4len {
+		return MakeIPv4(p[0], p[1], p[2], p[3])
+	}
+	if len(p) == IPv6len {
+		return p
+	}
+	return nil
+}
+
+// Default route masks for IPv4.
+export var (
+	ClassAMask = MakeIPv4(0xff, 0, 0, 0);
+	ClassBMask = MakeIPv4(0xff, 0xff, 0, 0);
+	ClassCMask = MakeIPv4(0xff, 0xff, 0xff, 0);
+)
+
+export func DefaultMask(p *[]byte) *[]byte {
+	if p = ToIPv4(p); p == nil {
+		return nil
+	}
+	switch true {
+	case p[0] < 0x80:
+		return ClassAMask;
+	case p[0] < 0xC0:
+		return ClassBMask;
+	default:
+		return ClassCMask;
+	}
+	return nil;	// not reached
+}
+
+// Apply mask to ip, returning new address.
+export func Mask(ip *[]byte, mask *[]byte) *[]byte {
+	n := len(ip)
+	if n != len(mask) {
+		return nil
+	}
+	out := new([]byte, n)
+	for i := 0; i < n; i++ {
+		out[i] = ip[i] & mask[i];
+	}
+	return out
+}
+
+// Convert i to decimal string.
+func itod(i uint) string {
+	if i == 0 {
+		return "0"
+	}
+
+	// Assemble decimal in reverse order.
+	var b [32]byte;
+	bp := len(b);
+	for ; i > 0; i /= 10 {
+		bp--;
+		b[bp] = byte(i%10) + '0'
+	}
+
+	// return string(b[bp:len(b)])
+	return string((&b)[bp:len(b)])
+}
+
+// Convert i to hexadecimal string.
+func itox(i uint) string {
+	if i == 0 {
+		return "0"
+	}
+
+	// Assemble hexadecimal in reverse order.
+	var b [32]byte;
+	bp := len(b);
+	for ; i > 0; i /= 16 {
+		bp--;
+		b[bp] = "0123456789abcdef"[byte(i%16)]
+	}
+
+	// return string(b[bp:len(b)])
+	return string((&b)[bp:len(b)])
+}
+
+// Convert IP address to string.
+export func IPToString(p *[]byte) string {
+	// If IPv4, use dotted notation.
+	if p4 := ToIPv4(p); p4 != nil {
+		return itod(uint(p4[0]))+"."
+			+itod(uint(p4[1]))+"."
+			+itod(uint(p4[2]))+"."
+			+itod(uint(p4[3]))
+	}
+	if len(p) != IPv6len {
+		return "?"
+	}
+
+	// Find longest run of zeros.
+	e0 := -1;
+	e1 := -1
+	for i := 0; i < 16; i+=2 {
+		j := i
+		for j < 16 && p[j] == 0 && p[j+1] == 0 {
+			j += 2
+		}
+		if j > i && j - i > e1 - e0 {
+			e0 = i;
+			e1 = j
+		}
+	}
+
+	// Print with possible :: in place of run of zeros
+	var s string;
+	for i := 0; i < 16; i += 2 {
+		if i == e0 {
+			s += "::";
+			i = e1
+			if i >= 16 {
+				break
+			}
+		} else if i > 0 {
+			s += ":"
+		}
+		s += itox((uint(p[i])<<8) | uint(p[i+1]))
+	}
+	return s
+}
+
+// If mask is a sequence of 1 bits followed by 0 bits,
+// return the number of 1 bits.
+func SimpleMaskLength(mask *[]byte) int {
+	var i int
+	for i = 0; i < len(mask); i++ {
+		if mask[i] != 0xFF {
+			break
+		}
+	}
+	n := 8*i;
+	v := mask[i]
+	for v & 0x80 != 0 {
+		n++
+		v <<= 1
+	}
+	if v != 0 {
+		return -1
+	}
+	for i++; i < len(mask); i++ {
+		if mask[i] != 0 {
+			return -1
+		}
+	}
+	return n
+}
+
+export func MaskToString(mask *[]byte) string {
+	switch len(mask) {
+	case 4:
+		n := SimpleMaskLength(mask)
+		if n >= 0 {
+			return itod(uint(n+(IPv6len-IPv4len)*8))
+		}
+	case 16:
+		n := SimpleMaskLength(mask)
+		if n >= 0 {
+			return itod(uint(n))
+		}
+	}
+	return IPToString(mask)
+}
+
+// Parsing.
+
+// Bigger than we need, not too big to worry about overflow
+const Big = 0xFFFFFF
+
+// Decimal to integer starting at &s[i].
+// Returns number, new offset, success.
+func dtoi(s string, i int) (n int, i1 int, ok bool) {
+	if len(s) <= i || s[i] < '0' || s[i] > '9' {
+		return 0, i, false
+	}
+	n = 0;
+	for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+		n = n*10 + int(s[i] - '0')
+		if n >= Big {
+			return 0, i, false
+		}
+	}
+	return n, i, true
+}
+
+// Is b a hex digit?
+func ishex(b byte) bool {
+	return '0' <= b && b <= '9'
+		|| 'a' <= b && b <= 'f'
+		|| 'A' <= b && b <= 'F'
+}
+
+// Hexadecimal to integer starting at &s[i].
+// Returns number, new offset, success.
+func xtoi(s string, i int) (n int, i1 int, ok bool) {
+	if len(s) <= i || !ishex(s[i]) {
+		return 0, i, false
+	}
+
+	n = 0;
+	for ; i < len(s) && ishex(s[i]); i++ {
+		n *= 16
+		if '0' <= s[i] && s[i] <= '9' {
+			n += int(s[i] - '0')
+		} else if 'a' <= s[i] && s[i] <= 'f' {
+			n += int(s[i] - 'a') + 10
+		} else {
+			n += int(s[i] -'A') + 10
+		}
+		if n >= Big {
+			return 0, i, false
+		}
+	}
+	return n, i, true
+}
+
+// Parse IPv4 address (d.d.d.d).
+func ParseIPv4(s string) *[]byte {
+	var p [IPv4len]byte
+	i := 0
+	for j := 0; j < IPv4len; j++ {
+		if j > 0 {
+			if s[i] != '.' {
+				return nil
+			}
+			i++
+		}
+		var (
+			n int;
+			ok bool
+		)
+		n, i, ok = dtoi(s, i)
+		if !ok || n > 0xFF {
+			return nil
+		}
+		p[j] = byte(n)
+	}
+	if i != len(s) {
+		return nil
+	}
+	return MakeIPv4(p[0], p[1], p[2], p[3])
+}
+
+// Parse IPv6 address.  Many forms.
+// The basic form is a sequence of eight colon-separated
+// 16-bit hex numbers separated by colons,
+// as in 0123:4567:89ab:cdef:0123:4567:89ab:cdef.
+// Two exceptions:
+//	* A run of zeros can be replaced with "::".
+//	* The last 32 bits can be in IPv4 form.
+// Thus, ::ffff:1.2.3.4 is the IPv4 address 1.2.3.4.
+func ParseIPv6(s string) *[]byte {
+	p := new([]byte, 16);
+	ellipsis := -1;	// position of ellipsis in p
+	i := 0;	// index in string s
+
+	// Might have leading ellipsis
+	if len(s) >= 2 && s[0] == ':' && s[1] == ':' {
+		ellipsis = 0;
+		i = 2
+	}
+
+	// Loop, parsing hex numbers followed by colon.
+	j := 0;
+L:	for j < IPv6len {
+		// Hex number.
+		n, i1, ok := xtoi(s, i)
+		if !ok || n >= 0xFFFF {
+			return nil
+		}
+
+		// If followed by dot, might be in trailing IPv4.
+		if s[i1] == '.' {
+			if ellipsis < 0 && j != IPv6len - IPv4len {
+				// Not the right place.
+				return nil
+			}
+			if j+IPv4len > IPv6len {
+				// Not enough room.
+				return nil
+			}
+			p4 := ParseIPv4(s[i:len(s)]);
+			if p4 == nil {
+				return nil
+			}
+			// BUG: p[j:j+4] = p4
+			p[j] = p4[12];
+			p[j+1] = p4[13];
+			p[j+2] = p4[14];
+			p[j+3] = p4[15];
+			i = len(s);
+			j += 4
+			break
+		}
+
+		// Save this 16-bit chunk.
+		p[j] = byte(n>>8);
+		p[j+1] = byte(n);
+		j += 2;
+
+		// Stop at end of string.
+		i = i1
+		if i == len(s) {
+			break
+		}
+
+		// Otherwise must be followed by colon and more.
+		if s[i] != ':' && i+1 == len(s) {
+			return nil
+		}
+		i++
+
+		// Look for ellipsis.
+		if s[i+1] == ':' {
+			if ellipsis >= 0 {	// already have one
+				return nil
+			}
+			ellipsis = j;
+			if i++; i == len(s) {	// can be at end
+				break
+			}
+		}
+	}
+
+	// Must have used entire string.
+	if i != len(s) {
+		return nil
+	}
+
+	// If didn't parse enough, expand ellipsis.
+	if j < IPv6len {
+		if ellipsis < 0 {
+			return nil
+		}
+		n := IPv6len - j
+		for k := j; k >= ellipsis; k-- {
+			p[k+n] = p[k]
+		}
+		for k := ellipsis+n-1; k>=ellipsis; k-- {
+			p[k] = 0
+		}
+	}
+	return p
+}
+
+export func ParseIP(s string) *[]byte {
+	p := ParseIPv4(s)
+	if p != nil {
+		return p
+	}
+	return ParseIPv6(s)
+}
+
diff --git a/src/lib/net/net.go b/src/lib/net/net.go
new file mode 100644
index 000000000..d44f2d305
--- /dev/null
+++ b/src/lib/net/net.go
@@ -0,0 +1,483 @@
+// 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 (
+	"os";
+	"ip";
+	"socket";
+	"strings";
+	"syscall"
+)
+
+func NewError(s string) *os.Error {
+	e := new(os.Error);
+	e.s = s;
+	return e
+}
+
+export var (
+	BadAddress = NewError("malformed addres");
+	UnknownNetwork = NewError("unknown network");
+	UnknownHost = NewError("unknown host");
+	UnknownPort = NewError("unknown port");
+	UnknownSocketFamily = NewError("unknown 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.
+	var i int
+	for i = len(hostport)-1; i >= 0; i-- {
+		if hostport[i] == ':' {
+			break
+		}
+	}
+	if i < 0 {
+		return "", "", BadAddress
+	}
+	
+	host = hostport[0:i];
+	port = hostport[i+1:len(hostport)];
+	
+	// Can put brackets around host ...
+	if host[0] == '[' && host[len(host)-1] == ']' {
+		host = host[1:len(host)-1]
+	} else {
+		// ... but if there are no brackets, no colons.
+		for i := 0; i < len(host); i++ {
+			if host[i] == ':' {
+				return "", "", BadAddress
+			}
+		}
+	}
+	return host, port, nil
+}
+
+// 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.
+	for i := 0; i < len(host); i++ {
+		if host[i] == ':' {
+			return "[" + host + "]:" + port
+		}
+	}
+	return host + ":" + port
+}
+
+// Convert "host:port" into IP address and port.
+// For now, host and port must be numeric literals.
+// Eventually, we'll have name resolution.
+func HostPortToIP(net string, hostport string) (ip *[]byte, iport int, err *os.Error) {
+	var host, port string;
+	host, port, err = SplitHostPort(hostport);
+	if err != nil {
+		return nil, 0, err
+	}
+	
+	// TODO: Resolve host.
+	
+	addr := ip.ParseIP(host);
+	if addr == nil {
+print("Failed to parse: ", host, "\n");
+		return nil, 0, UnknownHost
+	}
+	
+	// TODO: Resolve port.
+	
+	p, ok := strings.atoi(port);
+	if !ok || p < 0 || p > 0xFFFF {
+		return nil, 0, UnknownPort
+	}
+	
+	return addr, p, nil
+}
+
+// Convert socket address into "host:port".
+func SockaddrToHostPort(sa *socket.Sockaddr) (hostport string, err *os.Error) {
+	switch sa.family {
+	case socket.AF_INET, socket.AF_INET6:
+		addr, port, e := socket.SockaddrToIP(sa)
+		if e != nil {
+			return "", e
+		}
+		host := ip.IPToString(addr);
+		return JoinHostPort(host, strings.itoa(port)), nil
+	default:
+		return "", UnknownSocketFamily
+	}
+	return "", nil // not reached
+}
+
+// Boolean to int.
+func boolint(b bool) int {
+	if b {
+		return 1
+	} 
+	return 0
+}
+
+// Generic Socket creation.
+func Socket(f, p, t int64, la, ra *socket.Sockaddr) (fd int64, err *os.Error) {
+	s, e := socket.socket(f, p, t);
+	if e != nil {
+		return -1, e
+	}
+	
+	var r int64
+	if la != nil {
+		r, e = socket.bind(s, la)
+		if e != nil {
+			syscall.close(s)
+			return -1, e
+		}
+	}
+	
+	if ra != nil {
+		r, e = socket.connect(s, ra)
+		if e != nil {
+			syscall.close(s)
+			return -1, e
+		}
+	}
+	
+	return s, nil
+}
+
+
+// Generic implementation of Conn interface; not exported.
+
+type ConnBase struct {
+	fd *os.FD;
+	raddr string;
+}
+
+// Eventually, these will use epoll or some such.
+
+func (c *ConnBase) FD() int64 {
+	if c == nil || c.fd == nil {
+		return -1
+	}
+	return c.fd.fd
+}
+
+func (c *ConnBase) Read(b *[]byte) (n int, err *os.Error) {
+	n, err = c.fd.Read(b)
+	return n, err
+}
+
+func (c *ConnBase) Write(b *[]byte) (n int, err *os.Error) {
+	n, err = c.fd.Write(b)
+	return n, err
+}
+
+func (c *ConnBase) ReadFrom(b *[]byte) (n int, raddr string, err *os.Error) {
+	if c == nil {
+		return -1, "", os.EINVAL
+	}
+	n, err = c.Read(b)
+	return n, c.raddr, err
+}
+
+func (c *ConnBase) WriteTo(raddr string, b *[]byte) (n int, err *os.Error) {
+	if c == nil {
+		return -1, os.EINVAL
+	}
+	if raddr != c.raddr {
+		return -1, os.EINVAL
+	}
+	n, err = c.Write(b)
+	return n, err
+}
+
+func (c *ConnBase) Close() *os.Error {
+	if c == nil {
+		return os.EINVAL
+	}
+	return c.fd.Close()
+}
+
+func (c *ConnBase) SetReadBuffer(bytes int) *os.Error {
+	return socket.setsockopt_int(c.FD(), socket.SOL_SOCKET, socket.SO_RCVBUF, bytes);
+}
+
+func (c *ConnBase) SetWriteBuffer(bytes int) *os.Error {
+	return socket.setsockopt_int(c.FD(), socket.SOL_SOCKET, socket.SO_SNDBUF, bytes);
+}
+
+func (c *ConnBase) SetReadTimeout(nsec int64) *os.Error {
+	return socket.setsockopt_tv(c.FD(), socket.SOL_SOCKET, socket.SO_RCVTIMEO, nsec);
+}
+
+func (c *ConnBase) SetWriteTimeout(nsec int64) *os.Error {
+	return socket.setsockopt_tv(c.FD(), socket.SOL_SOCKET, socket.SO_SNDTIMEO, nsec);
+}
+
+func (c *ConnBase) SetTimeout(nsec int64) *os.Error {
+	if e := c.SetReadTimeout(nsec); e != nil {
+		return e
+	}
+	return c.SetWriteTimeout(nsec)
+}
+
+func (c *ConnBase) SetReuseAddr(reuse bool) *os.Error {
+	return socket.setsockopt_int(c.FD(), socket.SOL_SOCKET, socket.SO_REUSEADDR, boolint(reuse));
+}
+
+func (c *ConnBase) BindToDevice(dev string) *os.Error {
+	// TODO: call setsockopt with null-terminated string pointer
+	return os.EINVAL
+}
+
+func (c *ConnBase) SetDontRoute(dontroute bool) *os.Error {
+	return socket.setsockopt_int(c.FD(), socket.SOL_SOCKET, socket.SO_DONTROUTE, boolint(dontroute));
+}
+
+func (c *ConnBase) SetKeepAlive(keepalive bool) *os.Error {
+	return socket.setsockopt_int(c.FD(), socket.SOL_SOCKET, socket.SO_KEEPALIVE, boolint(keepalive));
+}
+
+func (c *ConnBase) SetLinger(sec int) *os.Error {
+	return socket.setsockopt_linger(c.FD(), socket.SOL_SOCKET, socket.SO_LINGER, sec);
+}
+
+
+// Internet sockets (TCP, UDP)
+
+// 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.
+// If we need to build on a system without IPv6 support, setting
+// PreferIPv4 here should fall back to the IPv4 socket interface when possible.
+const PreferIPv4 = false
+
+func DialInternet(net, laddr, raddr string, proto int64) (fd int64, err *os.Error) {
+	// Parse addresses (unless they are empty).
+	var lip, rip *[]byte
+	var lport, rport int
+	var lerr, rerr *os.Error
+	if laddr != "" {
+		lip, lport, lerr = HostPortToIP(net, laddr)
+		if lerr != nil {
+			return -1, lerr
+		}
+	}
+	if raddr != "" {
+		rip, rport, rerr = HostPortToIP(net, raddr)
+		if rerr != nil {
+			return -1, rerr
+		}
+	}
+
+	// Figure out IP version.  
+	// If network has a suffix like "tcp4", obey it.
+	vers := 0;
+	switch net[len(net)-1] {
+	case '4':
+		vers = 4
+	case '6':
+		vers = 6
+	default:
+		// Otherwise, guess.
+		// If the addresses are IPv4 and we prefer IPv4, use 4; else 6.
+		if PreferIPv4
+		&& (lip == nil || ip.ToIPv4(lip) != nil)
+		&& (rip == nil || ip.ToIPv4(rip) != nil) {
+			vers = 4
+		} else {
+			vers = 6
+		}
+	}
+
+	var cvt *(addr *[]byte, port int) (sa *socket.Sockaddr, err *os.Error)
+	var family int64
+	if vers == 4 {
+		cvt = &socket.IPv4ToSockaddr;
+		family = socket.AF_INET
+	} else {
+		cvt = &socket.IPv6ToSockaddr;
+		family = socket.AF_INET6
+	}
+	
+	var la, ra *socket.Sockaddr;
+	if lip != nil {
+		la, lerr = cvt(lip, lport);
+		if lerr != nil {
+			return -1, lerr
+		}
+	}
+	if rip != nil {
+		ra, rerr = cvt(rip, rport);
+		if rerr != nil {
+			return -1, rerr
+		}
+	}
+
+	fd, err = Socket(family, proto, 0, la, ra);
+	return fd, err
+}
+
+
+// TCP connections.
+
+export type ConnTCP struct {
+	base ConnBase
+}
+
+// New TCP methods
+func (c *ConnTCP) SetNoDelay(nodelay bool) *os.Error {
+	if c == nil {
+		return os.EINVAL
+	}
+	return socket.setsockopt_int(c.base.fd.fd, socket.IPPROTO_TCP, socket.TCP_NODELAY, boolint(nodelay))
+}
+
+// Wrappers
+func (c *ConnTCP) Read(b *[]byte) (n int, err *os.Error) {
+	n, err = (&c.base).Read(b)
+	return n, err
+}
+func (c *ConnTCP) Write(b *[]byte) (n int, err *os.Error) {
+	n, err = (&c.base).Write(b)
+	return n, err
+}
+func (c *ConnTCP) ReadFrom(b *[]byte) (n int, raddr string, err *os.Error) {
+	n, raddr, err = (&c.base).ReadFrom(b)
+	return n, raddr, err
+}
+func (c *ConnTCP) WriteTo(raddr string, b *[]byte) (n int, err *os.Error) {
+	n, err = (&c.base).WriteTo(raddr, b)
+	return n, err
+}
+func (c *ConnTCP) Close() *os.Error {
+	return (&c.base).Close()
+}
+func (c *ConnTCP) SetReadBuffer(bytes int) *os.Error {
+	return (&c.base).SetReadBuffer(bytes)
+}
+func (c *ConnTCP) SetWriteBuffer(bytes int) *os.Error {
+	return (&c.base).SetWriteBuffer(bytes)
+}
+func (c *ConnTCP) SetTimeout(nsec int64) *os.Error {
+	return (&c.base).SetTimeout(nsec)
+}
+func (c *ConnTCP) SetReadTimeout(nsec int64) *os.Error {
+	return (&c.base).SetReadTimeout(nsec)
+}
+func (c *ConnTCP) SetWriteTimeout(nsec int64) *os.Error {
+	return (&c.base).SetWriteTimeout(nsec)
+}
+func (c *ConnTCP) SetLinger(sec int) *os.Error {
+	return (&c.base).SetLinger(sec)
+}
+func (c *ConnTCP) SetReuseAddr(reuseaddr bool) *os.Error {
+	return (&c.base).SetReuseAddr(reuseaddr)
+}
+func (c *ConnTCP) BindToDevice(dev string) *os.Error {
+	return (&c.base).BindToDevice(dev)
+}
+func (c *ConnTCP) SetDontRoute(dontroute bool) *os.Error {
+	return (&c.base).SetDontRoute(dontroute)
+}
+func (c *ConnTCP) SetKeepAlive(keepalive bool) *os.Error {
+	return (&c.base).SetKeepAlive(keepalive)
+}
+
+export func DialTCP(net, laddr, raddr string) (c *ConnTCP, err *os.Error) {
+	fd, e := DialInternet(net, laddr, raddr, socket.SOCK_STREAM)
+	if e != nil {
+		return nil, e
+	}
+	c = new(ConnTCP);
+	c.base.fd = os.NewFD(fd);
+	c.SetNoDelay(true)
+	return c, nil
+}
+
+
+// TODO: UDP connections
+
+
+// TODO: raw IP connections
+
+
+// TODO: raw ethernet connections
+
+
+export type Conn interface {
+	Read(b *[]byte) (n int, err *os.Error);
+	Write(b *[]byte) (n int, err *os.Error);
+	ReadFrom(b *[]byte) (n int, addr string, err *os.Error);
+	WriteTo(addr string, b *[]byte) (n int, err *os.Error);
+	Close() *os.Error;
+	SetReadBuffer(bytes int) *os.Error;
+	SetWriteBuffer(bytes int) *os.Error;
+	SetTimeout(nsec int64) *os.Error;
+	SetReadTimeout(nsec int64) *os.Error;
+	SetWriteTimeout(nsec int64) *os.Error;
+	SetLinger(sec int) *os.Error;
+	SetReuseAddr(reuseaddr bool) *os.Error;
+	SetDontRoute(dontroute bool) *os.Error;
+	SetKeepAlive(keepalive bool) *os.Error;
+	BindToDevice(dev string) *os.Error;
+}
+
+type NoConn struct { unused int }
+func (c *NoConn) Read(b *[]byte) (n int, err *os.Error) { return -1, os.EINVAL }
+func (c *NoConn) Write(b *[]byte) (n int, err *os.Error) { return -1, os.EINVAL }
+func (c *NoConn) ReadFrom(b *[]byte) (n int, addr string, err *os.Error) { return -1, "", os.EINVAL }
+func (c *NoConn) WriteTo(addr string, b *[]byte) (n int, err *os.Error) { return -1, os.EINVAL }
+func (c *NoConn) Close() *os.Error { return nil }
+func (c *NoConn) SetReadBuffer(bytes int) *os.Error { return os.EINVAL }
+func (c *NoConn) SetWriteBuffer(bytes int) *os.Error { return os.EINVAL }
+func (c *NoConn) SetTimeout(nsec int64) *os.Error { return os.EINVAL }
+func (c *NoConn) SetReadTimeout(nsec int64) *os.Error { return os.EINVAL }
+func (c *NoConn) SetWriteTimeout(nsec int64) *os.Error { return os.EINVAL }
+func (c *NoConn) SetLinger(sec int) *os.Error { return os.EINVAL }
+func (c *NoConn) SetReuseAddr(reuseaddr bool) *os.Error { return os.EINVAL }
+func (c *NoConn) SetDontRoute(dontroute bool) *os.Error { return os.EINVAL }
+func (c *NoConn) SetKeepAlive(keepalive bool) *os.Error { return os.EINVAL }
+func (c *NoConn) BindToDevice(dev string) *os.Error { return os.EINVAL }
+
+var noconn NoConn
+
+// Dial's arguments are the network, local address, and remote address.
+// Examples:
+//	Dial("tcp", "", "12.34.56.78:80")
+//	Dial("tcp", "", "[de:ad:be:ef::ca:fe]:80")
+//	Dial("tcp", "127.0.0.1:123", "127.0.0.1:88")
+//
+// Eventually, we plan to allow names in addition to IP addresses,
+// but that requires writing a DNS library.
+
+export func Dial(net, laddr, raddr string) (c Conn, err *os.Error) {
+	switch net {
+	case "tcp", "tcp4", "tcp6":
+		c, err := DialTCP(net, laddr, raddr)
+		if err != nil {
+			return &noconn, err
+		}
+		return c, nil
+/*
+	case "udp", "udp4", "upd6":
+		c, err := DialUDP(net, laddr, raddr)
+		return c, err
+	case "ether":
+		c, err := DialEther(net, laddr, raddr)
+		return c, err
+	case "ipv4":
+		c, err := DialIPv4(net, laddr, raddr)
+		return c, err
+	case "ipv6":
+		c, err := DialIPv6(net, laddr, raddr)
+		return c, err
+*/
+	}
+	return nil, UnknownNetwork
+}
+
diff --git a/src/lib/net/socket_darwin.go b/src/lib/net/socket_darwin.go
new file mode 100644
index 000000000..a114002ea
--- /dev/null
+++ b/src/lib/net/socket_darwin.go
@@ -0,0 +1,231 @@
+// 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.
+
+// Low-level socket interface.
+// Only for implementing net package.
+// DO NOT USE DIRECTLY.
+
+package socket
+
+import (
+	"os";
+	"ip";
+	"syscall"
+)
+
+export const (
+	ACCEPT = 30;
+	SOCKET = 97;
+	CONNECT = 98;
+	GETSOCKOPT = 118;
+	BIND = 104;
+	SETSOCKOPT = 105;
+	LISTEN = 106;
+
+	AF_UNIX = 1;
+	AF_INET = 2;
+	AF_DATAKIT = 9;
+	AF_INET6 = 30;
+
+	SOCK_STREAM = 1;
+	SOCK_DGRAM = 2;
+	SOCK_RAW = 3;
+	SOCK_RDM = 4;
+	SOCK_SEQPACKET = 5;
+
+	SOL_SOCKET = 0xffff;
+
+	SO_REUSEADDR = 0x0004;
+	SO_KEEPALIVE = 0x0008;
+	SO_DONTROUTE = 0x0010;
+	SO_BROADCAST = 0x0020;
+	SO_USELOOPBACK = 0x0040;
+	SO_LINGER = 0x1080;
+	SO_REUSEPORT = 0x0200;
+	SO_SNDBUF = 0x1001;
+	SO_RCVBUF = 0x1002;
+	SO_SNDTIMEO = 0x1005;
+	SO_RCVTIMEO = 0x1006;
+	SO_NOSIGPIPE = 0x1022;
+
+	IPPROTO_TCP = 6;
+	IPPROTO_UDP = 17;
+
+	TCP_NODELAY = 0x01;
+)
+
+export type SockaddrUnix struct {
+	len	byte;
+	family	byte;
+	path	[104]byte
+}
+export const SizeofSockaddrUnix = 106
+
+export type SockaddrInet4 struct {
+	len	byte;
+	family	byte;
+	port	[2]byte;
+	addr	[4]byte;
+	zero	[8]byte
+}
+export const SizeofSockaddrInet4 = 16
+
+export type SockaddrInet6 struct {
+	len	byte;
+	family	byte;
+	port	[2]byte;
+	flowinfo	[4]byte;
+	addr	[16]byte;
+	scopeid	[4]byte;
+}
+export const SizeofSockaddrInet6 = 28
+
+export type Sockaddr struct {
+	len	byte;
+	family	byte;
+	opaque	[126]byte
+}
+export const SizeofSockaddr = 128
+
+export type Timeval struct {
+	sec int32;
+	usec int32;
+}
+export type Linger struct {
+	yes int32;
+	sec int32;
+}
+
+func SockaddrToSockaddrInet4(s *Sockaddr) *SockaddrInet4;
+func SockaddrToSockaddrInet6(s *Sockaddr) *SockaddrInet6;
+func SockaddrInet4ToSockaddr(s *SockaddrInet4) *Sockaddr;
+func SockaddrInet6ToSockaddr(s *SockaddrInet6) *Sockaddr;
+func SockaddrPtr(s *Sockaddr) int64;
+func Int32Ptr(ip *int32) int64;
+func TimevalPtr(tv *Timeval) int64;
+func LingerPtr(l *Linger) int64;
+
+export func socket(domain, proto, typ int64) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(SOCKET, domain, proto, typ);
+	return r1, os.ErrnoToError(e)
+}
+
+export func connect(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(CONNECT, fd, SockaddrPtr(sa), int64(sa.len));
+	return r1, os.ErrnoToError(e)
+}
+
+export func bind(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(BIND, fd, SockaddrPtr(sa), int64(sa.len));
+	return r1, os.ErrnoToError(e)
+}
+
+export func listen(fd, n int64) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(LISTEN, fd, n, 0);
+	return r1, os.ErrnoToError(e)
+}
+
+export func accept(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	n := int32(sa.len);
+	r1, r2, e := syscall.Syscall(ACCEPT, fd, SockaddrPtr(sa), Int32Ptr(&n));
+	return r1, os.ErrnoToError(e)
+}
+
+export func setsockopt(fd, level, opt, valueptr, length int64) (ret int64, err *os.Error) {
+	if fd < 0 {
+		return -1, os.EINVAL
+	}
+	r1, r2, e := syscall.Syscall6(SETSOCKOPT, fd, level, opt, valueptr, length, 0);
+	return r1, os.ErrnoToError(e)
+}
+
+export func setsockopt_int(fd, level, opt int64, value int) *os.Error {
+	n := int32(opt);
+	r1, e := setsockopt(fd, level, opt, Int32Ptr(&n), 4)
+	return e
+}
+
+export func setsockopt_tv(fd, level, opt, nsec int64) *os.Error {
+	var tv Timeval;
+	nsec += 999;
+	tv.sec = int32(nsec/1000000000);
+	tv.usec = int32(nsec%1000000000);
+	r1, e := setsockopt(fd, level, opt, TimevalPtr(&tv), 4)
+	return e
+}
+
+export func setsockopt_linger(fd, level, opt int64, sec int) *os.Error {
+	var l Linger;
+	if sec != 0 {
+		l.yes = 1;
+		l.sec = sec
+	} else {
+		l.yes = 0;
+		l.sec = 0
+	}
+	r1, err := setsockopt(fd, level, opt, LingerPtr(&l), 8)
+	return err
+}
+
+/*
+export func getsockopt(fd, level, opt, valueptr, lenptr int64) (ret int64, errno int64) {
+	r1, r2, err := syscall.Syscall6(GETSOCKOPT, fd, level, opt, valueptr, lenptr, 0);
+	return r1, err;
+}
+*/
+
+export func IPv4ToSockaddr(p *[]byte, port int) (sa1 *Sockaddr, err *os.Error) {
+	p = ip.ToIPv4(p)
+	if p == nil || port < 0 || port > 0xFFFF {
+		return nil, os.EINVAL
+	}
+	sa := new(SockaddrInet4);
+	sa.len = SizeofSockaddrInet4;
+	sa.family = AF_INET;
+	sa.port[0] = byte(port>>8);
+	sa.port[1] = byte(port);
+	for i := 0; i < ip.IPv4len; i++ {
+		sa.addr[i] = p[i]
+	}
+	return SockaddrInet4ToSockaddr(sa), nil
+}
+
+export func IPv6ToSockaddr(p *[]byte, port int) (sa1 *Sockaddr, err *os.Error) {
+	p = ip.ToIPv6(p)
+	if p == nil || port < 0 || port > 0xFFFF {
+		return nil, os.EINVAL
+	}
+	sa := new(SockaddrInet6);
+	sa.len = SizeofSockaddrInet6;
+	sa.family = AF_INET6;
+	sa.port[0] = byte(port>>8);
+	sa.port[1] = byte(port);
+	for i := 0; i < ip.IPv6len; i++ {
+		sa.addr[i] = p[i]
+	}
+	return SockaddrInet6ToSockaddr(sa), nil
+}
+
+export func SockaddrToIP(sa1 *Sockaddr) (p *[]byte, port int, err *os.Error) {
+	switch sa1.family {
+	case AF_INET:
+		sa := SockaddrToSockaddrInet4(sa1);
+		a := ip.ToIPv6(&sa.addr)
+		if a == nil {
+			return nil, 0, os.EINVAL
+		}
+		return a, int(sa.port[0])<<8 + int(sa.port[1]), nil
+	case AF_INET6:
+		sa := SockaddrToSockaddrInet6(sa1);
+		a := ip.ToIPv6(&sa.addr)
+		if a == nil {
+			return nil, 0, os.EINVAL
+		}
+		return a, int(sa.port[0])<<8 + int(sa.port[1]), nil
+	default:
+		return nil, 0, os.EINVAL
+	}
+	return nil, 0, nil	// not reached
+}
+
diff --git a/src/lib/net/socket_linux.go b/src/lib/net/socket_linux.go
new file mode 100644
index 000000000..5dacaf58e
--- /dev/null
+++ b/src/lib/net/socket_linux.go
@@ -0,0 +1,247 @@
+// 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.
+
+// Low-level socket interface.
+// Only for implementing net package.
+// DO NOT USE DIRECTLY.
+
+package socket
+
+import (
+	"os";
+	"ip";
+	"syscall"
+)
+
+export const (
+	SOCKET = 41;
+	CONNECT = 42;
+	ACCEPT = 43;
+	SETSOCKOPT = 54;
+	GETSOCKOPT = 55;
+	BIND = 49;
+	LISTEN = 50;
+
+	AF_UNIX = 1;
+	AF_INET = 2;
+	AF_INET6 = 10;
+
+	SOCK_STREAM = 1;
+	SOCK_DGRAM = 2;
+	SOCK_RAW = 3;
+	SOCK_RDM = 4;
+	SOCK_SEQPACKET = 5;
+
+	SOL_SOCKET = 1;
+
+	SO_DEBUG = 1;
+	SO_REUSEADDR = 2;
+	SO_TYPE = 3;
+	SO_ERROR = 4;
+	SO_DONTROUTE = 5;
+	SO_BROADCAST = 6;
+	SO_SNDBUF = 7;
+	SO_RCVBUF = 8;
+	SO_SNDBUFFORCE = 32;
+	SO_RCVBUFFORCE = 33;
+	SO_KEEPALIVE = 9;
+	SO_OOBINLINE = 10;
+	SO_NO_CHECK = 11;
+	SO_PRIORITY = 12;
+	SO_LINGER = 13;
+	SO_BSDCOMPAT = 14;
+	SO_PASSCRED = 16;
+	SO_PEERCRED = 17;
+	SO_RCVLOWAT = 18;
+	SO_SNDLOWAT = 19;
+	SO_RCVTIMEO = 20;
+	SO_SNDTIMEO = 21;
+	SO_BINDTODEVICE = 25;
+
+	IPPROTO_TCP = 6;
+	IPPROTO_UDP = 17;
+
+	TCP_NODELAY = 0x01;
+)
+
+export type SockaddrUnix struct {
+	family	uint16;
+	path	[108]byte
+}
+export const SizeofSockaddrUnix = 110
+
+export type SockaddrInet4 struct {
+	family	uint16;
+	port	[2]byte;
+	addr	[4]byte;
+	zero	[8]byte
+}
+export const SizeofSockaddrInet4 = 16
+
+export type SockaddrInet6 struct {
+	family	uint16;
+	port	[2]byte;
+	flowinfo	[4]byte;
+	addr	[16]byte;
+	scopeid	[4]byte;
+}
+export const SizeofSockaddrInet6 = 28
+
+export type Sockaddr struct {
+	family	uint16;
+	opaque	[126]byte
+}
+export const SizeofSockaddr = 128
+
+export type Timeval struct {
+	sec int32;
+	usec int32;
+}
+export type Linger struct {
+	yes int32;
+	sec int32;
+}
+
+func (s *Sockaddr) Len() int64 {
+	switch s.family {
+	case AF_UNIX:
+		return SizeofSockaddrUnix
+	case AF_INET:
+		return SizeofSockaddrInet4
+	case AF_INET6:
+		return SizeofSockaddrInet6
+	}
+	return 0
+}
+
+func SockaddrToSockaddrInet4(s *Sockaddr) *SockaddrInet4;
+func SockaddrToSockaddrInet6(s *Sockaddr) *SockaddrInet6;
+func SockaddrInet4ToSockaddr(s *SockaddrInet4) *Sockaddr;
+func SockaddrInet6ToSockaddr(s *SockaddrInet6) *Sockaddr;
+func SockaddrPtr(s *Sockaddr) int64;
+func Int32Ptr(ip *int32) int64;
+func TimevalPtr(tv *Timeval) int64;
+func LingerPtr(l *Linger) int64;
+
+export func socket(domain, proto, typ int64) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(SOCKET, domain, proto, typ);
+	return r1, os.ErrnoToError(e)
+}
+
+export func connect(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(CONNECT, fd, SockaddrPtr(sa), sa.Len());
+	return r1, os.ErrnoToError(e)
+}
+
+export func bind(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(BIND, fd, SockaddrPtr(sa), sa.Len());
+	return r1, os.ErrnoToError(e)
+}
+
+export func listen(fd, n int64) (ret int64, err *os.Error) {
+	r1, r2, e := syscall.Syscall(LISTEN, fd, n, 0);
+	return r1, os.ErrnoToError(e)
+}
+
+export func accept(fd int64, sa *Sockaddr) (ret int64, err *os.Error) {
+	n := int32(sa.Len());
+	r1, r2, e := syscall.Syscall(ACCEPT, fd, SockaddrPtr(sa), Int32Ptr(&n));
+	return r1, os.ErrnoToError(e)
+}
+
+export func setsockopt(fd, level, opt, valueptr, length int64) (ret int64, err *os.Error) {
+	if fd < 0 {
+		return -1, os.EINVAL
+	}
+	r1, r2, e := syscall.Syscall6(SETSOCKOPT, fd, level, opt, valueptr, length, 0);
+	return r1, os.ErrnoToError(e)
+}
+
+export func setsockopt_int(fd, level, opt int64, value int) *os.Error {
+	n := int32(opt);
+	r1, e := setsockopt(fd, level, opt, Int32Ptr(&n), 4)
+	return e
+}
+
+export func setsockopt_tv(fd, level, opt, nsec int64) *os.Error {
+	var tv Timeval;
+	nsec += 999;
+	tv.sec = int32(nsec/1000000000);
+	tv.usec = int32(nsec%1000000000);
+	r1, e := setsockopt(fd, level, opt, TimevalPtr(&tv), 4)
+	return e
+}
+
+export func setsockopt_linger(fd, level, opt int64, sec int) *os.Error {
+	var l Linger;
+	if sec != 0 {
+		l.yes = 1;
+		l.sec = sec
+	} else {
+		l.yes = 0;
+		l.sec = 0
+	}
+	r1, err := setsockopt(fd, level, opt, LingerPtr(&l), 8)
+	return err
+}
+
+/*
+export func getsockopt(fd, level, opt, valueptr, lenptr int64) (ret int64, errno int64) {
+	r1, r2, err := syscall.Syscall6(GETSOCKOPT, fd, level, opt, valueptr, lenptr, 0);
+	return r1, err;
+}
+*/
+
+export func IPv4ToSockaddr(p *[]byte, port int) (sa1 *Sockaddr, err *os.Error) {
+	p = ip.ToIPv4(p)
+	if p == nil || port < 0 || port > 0xFFFF {
+		return nil, os.EINVAL
+	}
+	sa := new(SockaddrInet4);
+	sa.family = AF_INET;
+	sa.port[0] = byte(port>>8);
+	sa.port[1] = byte(port);
+	for i := 0; i < ip.IPv4len; i++ {
+		sa.addr[i] = p[i]
+	}
+	return SockaddrInet4ToSockaddr(sa), nil
+}
+
+export func IPv6ToSockaddr(p *[]byte, port int) (sa1 *Sockaddr, err *os.Error) {
+	p = ip.ToIPv6(p)
+	if p == nil || port < 0 || port > 0xFFFF {
+		return nil, os.EINVAL
+	}
+	sa := new(SockaddrInet6);
+	sa.family = AF_INET6;
+	sa.port[0] = byte(port>>8);
+	sa.port[1] = byte(port);
+	for i := 0; i < ip.IPv6len; i++ {
+		sa.addr[i] = p[i]
+	}
+	return SockaddrInet6ToSockaddr(sa), nil
+}
+
+export func SockaddrToIP(sa1 *Sockaddr) (p *[]byte, port int, err *os.Error) {
+	switch sa1.family {
+	case AF_INET:
+		sa := SockaddrToSockaddrInet4(sa1);
+		a := ip.ToIPv6(&sa.addr)
+		if a == nil {
+			return nil, 0, os.EINVAL
+		}
+		return a, int(sa.port[0])<<8 + int(sa.port[1]), nil
+	case AF_INET6:
+		sa := SockaddrToSockaddrInet6(sa1);
+		a := ip.ToIPv6(&sa.addr)
+		if a == nil {
+			return nil, 0, os.EINVAL
+		}
+		return a, int(sa.port[0])<<8 + int(sa.port[1]), nil
+	default:
+		return nil, 0, os.EINVAL
+	}
+	return nil, 0, nil	// not reached
+}
+