split ipsock.go, sock.go, and unixsock.go out of net.go

prior to cleanup.  no changes, only moving.

remove dependencies on strconv and strings

R=r
http://go/go-review/1017010

1 files changed, 362 insertions, 0 deletions

diff --git a/src/pkg/net/ipsock.go b/src/pkg/net/ipsock.go
new file mode 100644
index 000000000..640695256
--- /dev/null
+++ b/src/pkg/net/ipsock.go
@@ -0,0 +1,362 @@
+// 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 {
+	fd, e := syscall.Socket(syscall.AF_INET6, syscall.SOCK_STREAM, syscall.IPPROTO_TCP);
+	if fd >= 0 {
+		syscall.Close(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
+}
+
+// ListenerTCP is a TCP network listener.
+// Clients should typically use variables of type Listener
+// instead of assuming TCP.
+type ListenerTCP struct {
+	fd *netFD;
+}
+
+// ListenTCP announces on the TCP address laddr and returns a TCP listener.
+// Net must be "tcp", "tcp4", or "tcp6".
+// If laddr has a port of 0, it means to listen on some available port.
+// The caller can use l.Addr() to retrieve the chosen address.
+func ListenTCP(net, laddr string) (l *ListenerTCP, err os.Error) {
+	fd, e := internetSocket(net, laddr, "", syscall.SOCK_STREAM, "listen");
+	if e != nil {
+		return nil, e
+	}
+	e1 := syscall.Listen(fd.fd, listenBacklog());
+	if e1 != 0 {
+		syscall.Close(fd.fd);
+		return nil, &OpError{"listen", "tcp", laddr, os.Errno(e1)};
+	}
+	l = new(ListenerTCP);
+	l.fd = fd;
+	return l, nil
+}
+
+// AcceptTCP accepts the next incoming call and returns the new connection
+// and the remote address.
+func (l *ListenerTCP) AcceptTCP() (c *ConnTCP, raddr string, err os.Error) {
+	if l == nil || l.fd == nil || l.fd.fd < 0 {
+		return nil, "", os.EINVAL
+	}
+	fd, e := l.fd.accept();
+	if e != nil {
+		return nil, "", e
+	}
+	return newConnTCP(fd, fd.raddr), fd.raddr, nil
+}
+
+// Accept implements the Accept method in the Listener interface;
+// it waits for the next call and returns a generic Conn.
+func (l *ListenerTCP) Accept() (c Conn, raddr string, err os.Error) {
+	c1, r1, e1 := l.AcceptTCP();
+	if e1 != nil {
+		return nil, "", e1
+	}
+	return c1, r1, nil
+}
+
+// Close stops listening on the TCP address.
+// Already Accepted connections are not closed.
+func (l *ListenerTCP) Close() os.Error {
+	if l == nil || l.fd == nil {
+		return os.EINVAL
+	}
+	return l.fd.Close()
+}
+
+// Addr returns the listener's network address.
+func (l *ListenerTCP) Addr() string {
+	return l.fd.addr();
+}
+
+// Internet sockets (TCP, UDP)
+
+func internetSocket(net, laddr, raddr string, proto int, mode string) (fd *netFD, err os.Error) {
+	// Parse addresses (unless they are empty).
+	var lip, rip IP;
+	var lport, rport int;
+
+	if laddr != "" {
+		if lip, lport, err = hostPortToIP(net, laddr, mode); err != nil {
+			goto Error;
+		}
+	}
+	if raddr != "" {
+		if rip, rport, err = hostPortToIP(net, raddr, mode); err != nil {
+			goto Error;
+		}
+	}
+
+	// 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 || lip.To4() != nil) && (rip == nil || rip.To4() != nil) {
+			vers = 4
+		} else {
+			vers = 6
+		}
+	}
+
+	var family int;
+	if vers == 4 {
+		family = syscall.AF_INET
+	} else {
+		family = syscall.AF_INET6
+	}
+
+	var la, ra syscall.Sockaddr;
+	if lip != nil {
+		if la, err = ipToSockaddr(family, lip, lport); err != nil {
+			goto Error;
+		}
+	}
+	if rip != nil {
+		if ra, err = ipToSockaddr(family, rip, rport); err != nil {
+			goto Error;
+		}
+	}
+
+	fd, err = socket(net, laddr, raddr, family, proto, 0, la, ra);
+	if err != nil {
+		goto Error;
+	}
+	return fd, nil;
+
+Error:
+	addr := raddr;
+	if mode == "listen" {
+		addr = laddr;
+	}
+	return nil, &OpError{mode, net, addr, err};
+}
+
+
+// TCP connections.
+
+// ConnTCP is an implementation of the Conn interface
+// for TCP network connections.
+type ConnTCP struct {
+	connBase
+}
+
+func (c *ConnTCP) SetNoDelay(nodelay bool) os.Error {
+	if c == nil {
+		return os.EINVAL
+	}
+	return setsockoptInt(c.sysFD(), syscall.IPPROTO_TCP, syscall.TCP_NODELAY, boolint(nodelay))
+}
+
+func newConnTCP(fd *netFD, raddr string) *ConnTCP {
+	c := new(ConnTCP);
+	c.fd = fd;
+	c.raddr = raddr;
+	c.SetNoDelay(true);
+	return c
+}
+
+// DialTCP is like Dial but can only connect to TCP networks
+// and returns a ConnTCP structure.
+func DialTCP(net, laddr, raddr string) (c *ConnTCP, err os.Error) {
+	if raddr == "" {
+		return nil, &OpError{"dial", "tcp", "", errMissingAddress}
+	}
+	fd, e := internetSocket(net, laddr, raddr, syscall.SOCK_STREAM, "dial");
+	if e != nil {
+		return nil, e
+	}
+	return newConnTCP(fd, raddr), nil
+}
+
+
+// UDP connections.
+
+// TODO(rsc): UDP headers mode
+
+// ConnUDP is an implementation of the Conn interface
+// for UDP network connections.
+type ConnUDP struct {
+	connBase
+}
+
+func newConnUDP(fd *netFD, raddr string) *ConnUDP {
+	c := new(ConnUDP);
+	c.fd = fd;
+	c.raddr = raddr;
+	return c
+}
+
+// DialUDP is like Dial but can only connect to UDP networks
+// and returns a ConnUDP structure.
+func DialUDP(net, laddr, raddr string) (c *ConnUDP, err os.Error) {
+	if raddr == "" {
+		return nil, &OpError{"dial", "udp", "", errMissingAddress}
+	}
+	fd, e := internetSocket(net, laddr, raddr, syscall.SOCK_DGRAM, "dial");
+	if e != nil {
+		return nil, e
+	}
+	return newConnUDP(fd, raddr), nil
+}
+
+func ipToSockaddr(family int, ip IP, port int) (syscall.Sockaddr, os.Error) {
+	switch family {
+	case syscall.AF_INET:
+		if ip = ip.To4(); ip == nil {
+			return nil, os.EINVAL
+		}
+		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:
+		// 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, os.EINVAL
+		}
+		s := new(syscall.SockaddrInet6);
+		for i := 0; i < IPv6len; i++ {
+			s.Addr[i] = ip[i];
+		}
+		s.Port = port;
+		return s, nil;
+	}
+	return nil, os.EINVAL;
+}
+
+// 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:len(hostport)];
+
+	// 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.
+// For now, host and port must be numeric literals.
+// Eventually, we'll have name resolution.
+func hostPortToIP(net, hostport, mode string) (ip IP, iport int, err os.Error) {
+	host, port, err := splitHostPort(hostport);
+	if err != nil {
+		goto Error;
+	}
+
+	var addr IP;
+	if host == "" {
+		if mode != "listen" {
+			err = &AddrError{"no host in address", hostport};
+			goto Error;
+		}
+		if preferIPv4 {
+			addr = IPv4zero;
+		} else {
+			addr = IPzero;	// wildcard - listen to all
+		}
+	}
+
+	// Try as an IP address.
+	if addr == nil {
+		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;
+}
+