From 58cb7e09a8265cff793732bd07a818e555ba2429 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=BA=90=E6=96=87=E9=9B=A8?=
 <41315874+fumiama@users.noreply.github.com>
Date: Wed, 17 Jul 2024 14:08:59 +0900
Subject: [PATCH] optimize(lower): nic route setting

---
 lower/nic.go            | 30 +++++++++++++++++++-----------
 lower/tun_darwin.go     | 13 ++++++++++---
 lower/tun_linux.go      |  4 +---
 lower/tun_windows.go    |  9 ++-------
 upper/services/wg/wg.go |  8 ++++++--
 5 files changed, 38 insertions(+), 26 deletions(-)

diff --git a/lower/nic.go b/lower/nic.go
index c9d416b..2d0f1c2 100644
--- a/lower/nic.go
+++ b/lower/nic.go
@@ -2,8 +2,10 @@ package lower
 
 import (
 	"io"
+	"net"
 	"os"
 	"os/exec"
+	"strconv"
 
 	"github.com/fumiama/water"
 	"github.com/sirupsen/logrus"
@@ -17,29 +19,35 @@ type NICIO interface {
 
 // NIC 虚拟网卡
 type NIC struct {
-	ifce   *water.Interface
-	ip     string
-	subnet string
-	mtu    string
-	cidrs  []string
+	ifce     *water.Interface
+	ip       net.IP
+	subnet   *net.IPNet
+	rawipnet string
+	mtu      string
+	cidrs    []string
 }
 
 // NewNIC 新建 TUN 网络接口卡
 // 网卡地址为 ip, 所属子网为 subnet
 // 以本网卡为下一跳的所有子网为 cidrs
 // cidrs 不包括本网卡 subnet
-func NewNIC(ip, subnet, mtu string, cidrs ...string) NICIO {
+func NewNIC(ip net.IP, subnet *net.IPNet, mtu string, cidrs ...string) NICIO {
 	ifce, err := water.New(water.Config{DeviceType: water.TUN})
 	if err != nil {
 		logrus.Error(err)
 		os.Exit(1)
 	}
+	subn, bitsn := subnet.Mask.Size()
+	if bitsn != 32 {
+		panic("mask len " + strconv.Itoa(bitsn) + " is not supported")
+	}
 	n := &NIC{
-		ifce:   ifce,
-		ip:     ip,
-		subnet: subnet,
-		mtu:    mtu,
-		cidrs:  cidrs,
+		ifce:     ifce,
+		ip:       ip,
+		subnet:   subnet,
+		rawipnet: ip.String() + "/" + strconv.Itoa(subn),
+		mtu:      mtu,
+		cidrs:    cidrs,
 	}
 	return n
 }
diff --git a/lower/tun_darwin.go b/lower/tun_darwin.go
index 776ff67..9a72df4 100644
--- a/lower/tun_darwin.go
+++ b/lower/tun_darwin.go
@@ -3,17 +3,24 @@
 
 package lower
 
+import "net"
+
 func (n *NIC) Up() {
 	execute("ifconfig", n.ifce.Name(), "mtu", n.mtu) // max: 9159
-	execute("ifconfig", n.ifce.Name(), "inet", n.ip, n.ip, "up")
-	execute("route", "add", n.subnet, "-interface", n.ifce.Name())
+	execute(
+		"ifconfig", n.ifce.Name(),
+		"inet", n.ip.String(), n.ip.String(),
+		"netmask", (net.IP)(n.subnet.Mask).String(),
+		"up",
+	)
+	execute("route", "add", n.subnet.String(), "-interface", n.ifce.Name())
 	for _, c := range n.cidrs {
 		execute("route", "add", c, "-interface", n.ifce.Name())
 	}
 }
 
 func (n *NIC) Down() {
-	execute("route", "delete", n.subnet, "-interface", n.ifce.Name())
+	execute("route", "delete", n.subnet.String(), "-interface", n.ifce.Name())
 	for _, c := range n.cidrs {
 		execute("route", "delete", c, "-interface", n.ifce.Name())
 	}
diff --git a/lower/tun_linux.go b/lower/tun_linux.go
index 3dad251..145ecd1 100644
--- a/lower/tun_linux.go
+++ b/lower/tun_linux.go
@@ -5,16 +5,14 @@ package lower
 
 func (n *NIC) Up() {
 	execute("/sbin/ip", "link", "set", "dev", n.ifce.Name(), "mtu", n.mtu)
-	execute("/sbin/ip", "addr", "add", n.ip, "dev", n.ifce.Name())
+	execute("/sbin/ip", "addr", "add", n.rawipnet, "dev", n.ifce.Name())
 	execute("/sbin/ip", "link", "set", "dev", n.ifce.Name(), "up")
-	execute("/sbin/ip", "route", "add", n.subnet, "dev", n.ifce.Name())
 	for _, c := range n.cidrs {
 		execute("/sbin/ip", "route", "add", c, "dev", n.ifce.Name())
 	}
 }
 
 func (n *NIC) Down() {
-	execute("/sbin/ip", "route", "del", n.subnet, "dev", n.ifce.Name())
 	for _, c := range n.cidrs {
 		execute("/sbin/ip", "route", "del", c, "dev", n.ifce.Name())
 	}
diff --git a/lower/tun_windows.go b/lower/tun_windows.go
index bdbb625..f9a2851 100644
--- a/lower/tun_windows.go
+++ b/lower/tun_windows.go
@@ -6,19 +6,14 @@ package lower
 import "net"
 
 func (n *NIC) Up() {
-	// execute("netsh", "interface", "set", "interface", n.ifce.Name(), "enabled")
-	_, ipn, err := net.ParseCIDR(n.subnet)
-	if err != nil {
-		panic(err)
-	}
-	execute("cmd", "/c", "netsh interface ip set address name=\""+n.ifce.Name()+"\" source=static addr=\""+n.ip+"\" mask=\""+(net.IP)(ipn.Mask).String()+"\" gateway=none")
+	execute("cmd", "/c", "netsh interface ip set address name=\""+n.ifce.Name()+"\" source=static addr=\""+n.ip.String()+"\" mask=\""+(net.IP)(n.subnet.Mask).String()+"\" gateway=none")
 	execute("cmd", "/c", "netsh interface ipv4 set subinterface \""+n.ifce.Name()+"\" mtu="+n.mtu)
 	for _, c := range n.cidrs {
 		ip, cidr, err := net.ParseCIDR(c)
 		if err != nil {
 			panic(err)
 		}
-		execute("cmd", "/c", "route ADD "+ip.String()+" MASK "+(net.IP)(cidr.Mask).String()+" "+n.ip)
+		execute("cmd", "/c", "route ADD "+ip.String()+" MASK "+(net.IP)(cidr.Mask).String()+" "+n.ip.String())
 	}
 }
 
diff --git a/upper/services/wg/wg.go b/upper/services/wg/wg.go
index 29de02b..b3fb9db 100644
--- a/upper/services/wg/wg.go
+++ b/upper/services/wg/wg.go
@@ -72,6 +72,10 @@ func (wg *WG) init(srcport, dstport uint16) {
 	if err != nil {
 		panic(err)
 	}
+	myip := net.ParseIP(wg.c.IP)
+	if myip == nil {
+		panic("invalid ip " + wg.c.IP)
+	}
 	for _, p := range wg.c.Peers {
 		for _, ip := range p.AllowedIPs {
 			if len(ip) == 0 || ip[0] == 'x' {
@@ -94,11 +98,11 @@ func (wg *WG) init(srcport, dstport uint16) {
 	}
 
 	wg.me = link.NewMe(&link.MyConfig{
-		MyIPwithMask: wg.c.IP + "/32",
+		MyIPwithMask: myip.String() + "/32",
 		MyEndpoint:   wg.c.EndPoint,
 		Network:      wg.c.Network,
 		PrivateKey:   &wg.key,
-		NIC:          lower.NewNIC(wg.c.IP, wg.c.SubNet, strconv.FormatInt(wg.c.MTU, 10), cidrs...),
+		NIC:          lower.NewNIC(myip, mysubnet, strconv.FormatInt(wg.c.MTU, 10), cidrs...),
 		SrcPort:      srcport,
 		DstPort:      dstport,
 		MTU:          uint16(wg.c.MTU),