From 69f0fe67b63d90e523a5a1241fb1b46c2e8dbe03 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 3 Mar 2019 04:04:41 +0100
Subject: global: begin modularization

---
 device/conn.go | 180 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 180 insertions(+)
 create mode 100644 device/conn.go

(limited to 'device/conn.go')

diff --git a/device/conn.go b/device/conn.go
new file mode 100644
index 0000000..2594680
--- /dev/null
+++ b/device/conn.go
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"errors"
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+	"net"
+)
+
+const (
+	ConnRoutineNumber = 2
+)
+
+/* A Bind handles listening on a port for both IPv6 and IPv4 UDP traffic
+ */
+type Bind interface {
+	SetMark(value uint32) error
+	ReceiveIPv6(buff []byte) (int, Endpoint, error)
+	ReceiveIPv4(buff []byte) (int, Endpoint, error)
+	Send(buff []byte, end Endpoint) error
+	Close() error
+}
+
+/* An Endpoint maintains the source/destination caching for a peer
+ *
+ * dst : the remote address of a peer ("endpoint" in uapi terminology)
+ * src : the local address from which datagrams originate going to the peer
+ */
+type Endpoint interface {
+	ClearSrc()           // clears the source address
+	SrcToString() string // returns the local source address (ip:port)
+	DstToString() string // returns the destination address (ip:port)
+	DstToBytes() []byte  // used for mac2 cookie calculations
+	DstIP() net.IP
+	SrcIP() net.IP
+}
+
+func parseEndpoint(s string) (*net.UDPAddr, error) {
+
+	// ensure that the host is an IP address
+
+	host, _, err := net.SplitHostPort(s)
+	if err != nil {
+		return nil, err
+	}
+	if ip := net.ParseIP(host); ip == nil {
+		return nil, errors.New("Failed to parse IP address: " + host)
+	}
+
+	// parse address and port
+
+	addr, err := net.ResolveUDPAddr("udp", s)
+	if err != nil {
+		return nil, err
+	}
+	ip4 := addr.IP.To4()
+	if ip4 != nil {
+		addr.IP = ip4
+	}
+	return addr, err
+}
+
+func unsafeCloseBind(device *Device) error {
+	var err error
+	netc := &device.net
+	if netc.bind != nil {
+		err = netc.bind.Close()
+		netc.bind = nil
+	}
+	netc.stopping.Wait()
+	return err
+}
+
+func (device *Device) BindSetMark(mark uint32) error {
+
+	device.net.Lock()
+	defer device.net.Unlock()
+
+	// check if modified
+
+	if device.net.fwmark == mark {
+		return nil
+	}
+
+	// update fwmark on existing bind
+
+	device.net.fwmark = mark
+	if device.isUp.Get() && device.net.bind != nil {
+		if err := device.net.bind.SetMark(mark); err != nil {
+			return err
+		}
+	}
+
+	// clear cached source addresses
+
+	device.peers.RLock()
+	for _, peer := range device.peers.keyMap {
+		peer.Lock()
+		defer peer.Unlock()
+		if peer.endpoint != nil {
+			peer.endpoint.ClearSrc()
+		}
+	}
+	device.peers.RUnlock()
+
+	return nil
+}
+
+func (device *Device) BindUpdate() error {
+
+	device.net.Lock()
+	defer device.net.Unlock()
+
+	// close existing sockets
+
+	if err := unsafeCloseBind(device); err != nil {
+		return err
+	}
+
+	// open new sockets
+
+	if device.isUp.Get() {
+
+		// bind to new port
+
+		var err error
+		netc := &device.net
+		netc.bind, netc.port, err = CreateBind(netc.port, device)
+		if err != nil {
+			netc.bind = nil
+			netc.port = 0
+			return err
+		}
+
+		// set fwmark
+
+		if netc.fwmark != 0 {
+			err = netc.bind.SetMark(netc.fwmark)
+			if err != nil {
+				return err
+			}
+		}
+
+		// clear cached source addresses
+
+		device.peers.RLock()
+		for _, peer := range device.peers.keyMap {
+			peer.Lock()
+			defer peer.Unlock()
+			if peer.endpoint != nil {
+				peer.endpoint.ClearSrc()
+			}
+		}
+		device.peers.RUnlock()
+
+		// start receiving routines
+
+		device.net.starting.Add(ConnRoutineNumber)
+		device.net.stopping.Add(ConnRoutineNumber)
+		go device.RoutineReceiveIncoming(ipv4.Version, netc.bind)
+		go device.RoutineReceiveIncoming(ipv6.Version, netc.bind)
+		device.net.starting.Wait()
+
+		device.log.Debug.Println("UDP bind has been updated")
+	}
+
+	return nil
+}
+
+func (device *Device) BindClose() error {
+	device.net.Lock()
+	err := unsafeCloseBind(device)
+	device.net.Unlock()
+	return err
+}
\ No newline at end of file
-- 
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