From eb6bb7d15d12563bc64a4d0b67f6f7ea689c671f Mon Sep 17 00:00:00 2001
From: KusakabeSi <si@kskb.eu.org>
Date: Sun, 2 Jan 2022 19:00:54 +0000
Subject: [PATCH] Allow exact IP, update error msg, fix getIFIndex

---
 gencfg/gencfgNM.go | 28 ++++++++++++++++++++++++++++
 tap/tap.go         |  3 +++
 tap/tap_linux.go   | 13 +++++++------
 3 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/gencfg/gencfgNM.go b/gencfg/gencfgNM.go
index 22a6dcb..0813e45 100644
--- a/gencfg/gencfgNM.go
+++ b/gencfg/gencfgNM.go
@@ -192,7 +192,35 @@ func GenNMCfg(NMCinfigPath string, enableP2P bool, printExample bool) (err error
 	if enableP2P {
 		econfig.NextHopTable = make(mtypes.NextHopTable)
 	}
+	ModeIDmax := 0
+	for id, _ := range NMCfg.NetworkName {
+		if ModeIDmax < id {
+			ModeIDmax = id
+		}
+	}
+	IPv4Block := NMCfg.EdgeNode.IPv4Range
+	if IPv4Block != "" {
+		_, _, err = tap.GetIP(4, IPv4Block, uint32(ModeIDmax))
+		if err != nil {
+			return err
+		}
+	}
 
+	IPv6Block := NMCfg.EdgeNode.IPv6Range
+	if IPv6Block != "" {
+		_, _, err = tap.GetIP(6, IPv6Block, uint32(ModeIDmax))
+		if err != nil {
+			return err
+		}
+	}
+
+	IPv6LLBlock := NMCfg.EdgeNode.IPv6LLRange
+	if IPv6LLBlock != "" {
+		_, _, err = tap.GetIP(6, IPv6LLBlock, uint32(ModeIDmax))
+		if err != nil {
+			return err
+		}
+	}
 	econfig.DynamicRoute.NTPConfig.Servers = make([]string, 0)
 	econfig.DynamicRoute.SuperNode.PSKey = ""
 	econfig.DynamicRoute.SuperNode.EndpointV4 = ""
diff --git a/tap/tap.go b/tap/tap.go
index edc3ced..a6c4190 100644
--- a/tap/tap.go
+++ b/tap/tap.go
@@ -55,6 +55,9 @@ func GetIP(version int, netcidr string, uid uint32) (net.IP, net.IPMask, error)
 		}
 	}
 	ones, bits := the_net.Mask.Size()
+	if ones == bits {
+		return the_net.IP, the_net.Mask, nil
+	}
 	maxuid := big.NewInt(1)
 	maxuid.Lsh(maxuid, uint((bits - ones)))
 	ip_use := big.NewInt(int64(uid))
diff --git a/tap/tap_linux.go b/tap/tap_linux.go
index bd2e854..e75b137 100644
--- a/tap/tap_linux.go
+++ b/tap/tap_linux.go
@@ -291,19 +291,19 @@ func (tap *NativeTap) addIPAddr(version string, ip net.IP, mask net.IPMask) (err
 		e := exec.Command("ip", "addr", "add", ip.String()+"/"+masklen, "dev", name)
 		ret, err := e.CombinedOutput()
 		if err != nil {
-			fmt.Println("Please make sure `ip` tool installed")
+			fmt.Printf("Failed to set ip %v to interface %v, please make sure `ip` tool installed\n", ip.String()+"/"+masklen, name)
 			return fmt.Errorf(string(ret))
 		}
 	} else if version == "6ll" {
 		_, llnet, _ := net.ParseCIDR("fe80::/64")
 
-		if llnet.Contains(ip) == false {
+		if !llnet.Contains(ip) {
 			return fmt.Errorf("%v is not a link-local address", ip)
 		}
 		e := exec.Command("ip", "addr", "add", ip.String()+"/64", "dev", name)
 		ret, err := e.CombinedOutput()
 		if err != nil {
-			fmt.Println("Please make sure `ip` tool installed")
+			fmt.Printf("Failed to set ip %v to interface %v, please make sure `ip` tool installed\n", ip.String()+"/64", name)
 			return fmt.Errorf(string(ret))
 		}
 	}
@@ -330,8 +330,9 @@ func (tap *NativeTap) setUp() (err error) {
 
 func getIFIndex(name string) (ret int32, err error) {
 	var ifr [ifReqSize]byte
+	copy(ifr[:unix.IFNAMSIZ], name) // 0-16
 	err = ioctlRequest(unix.SIOCGIFINDEX, uintptr(unsafe.Pointer(&ifr[0])))
-	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), nil
+	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), err
 }
 
 func (tap *NativeTap) setMTU(n uint16) (err error) {
@@ -359,7 +360,7 @@ func (tap *NativeTap) MTU() (int, error) {
 	copy(ifr[:], name)
 	err = ioctlRequest(unix.SIOCGIFMTU, uintptr(unsafe.Pointer(&ifr[0])))
 
-	return int(*(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), nil
+	return int(*(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), err
 }
 
 func (tap *NativeTap) Name() (string, error) {
@@ -558,7 +559,7 @@ func CreateTAPFromFile(file *os.File, iconfig mtypes.InterfaceConf, NodeID mtype
 		e := exec.Command("ip", "addr", "flush", "dev", tapname)
 		_, err := e.CombinedOutput()
 		if err != nil {
-			fmt.Println("Please make sure `ip` tool installed")
+			fmt.Printf("Failed to flush ip from interface %v , please make sure `ip` tool installed\n", tapname)
 			return nil, err
 		}
 		cidrstr := iconfig.IPv6LLPrefix