From a31898c41db86646fd8a9fe23e57dfc6e2abeb7b Mon Sep 17 00:00:00 2001
From: mykola2312 <49044616+mykola2312@users.noreply.github.com>
Date: Mon, 27 Jan 2025 00:52:41 +0200
Subject: [PATCH] begin implementing lux interface enumeration

---
 host/lux_netif.go | 107 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 host/lux_netif.go

diff --git a/host/lux_netif.go b/host/lux_netif.go
new file mode 100644
index 0000000..8294594
--- /dev/null
+++ b/host/lux_netif.go
@@ -0,0 +1,107 @@
+package host
+
+import (
+	"lux/proto"
+	"net"
+	"net/netip"
+)
+
+// Option containing all network interfaces of host (excluding loopbacks)
+
+// IPv6 GUA
+// IPv6 ULA
+// IPv6 LL
+// IPv4
+
+type LuxNetAddrType int
+
+const (
+	LuxNetAddrType4    = 0
+	LuxNetAddrType6LL  = 1
+	LuxNetAddrType6ULA = 2
+	LuxNetAddrType6GUA = 3
+)
+
+type LuxNetAddr struct {
+	Type LuxNetAddrType
+	Addr netip.Addr
+}
+
+type LuxNetInterface struct {
+	Name  string
+	Index int
+	Addrs []LuxNetAddr
+}
+
+func NewLuxNetInterface(netif *net.Interface) (LuxNetInterface, error) {
+	luxNet := LuxNetInterface{
+		Name:  netif.Name,
+		Index: netif.Index,
+		Addrs: make([]LuxNetAddr, 0),
+	}
+
+	// enumerate interface ips
+	addrs, err := netif.Addrs()
+	if err != nil {
+		return luxNet, err
+	}
+
+	for _, addr := range addrs {
+		ip := net.ParseIP(addr.String())
+		if ip == nil {
+			return luxNet, err
+		}
+
+		luxAddr := LuxNetAddr{}
+		if ip.IsLoopback() {
+			continue // loopbacks are useless to LUX
+		} else if ip.To4() == nil {
+			// got IPv6
+			if ip.IsLinkLocalUnicast() {
+				luxAddr.Type = LuxNetAddrType6LL
+			} else if ip[0] == 0xFD || ip[0] == 0xFC {
+				// ULA - fc00::/7 with L = 1 -> fd00::/8,
+				// tho fc L 0 is not defined we still gonna assume its ULA
+				luxAddr.Type = LuxNetAddrType6ULA
+			} else {
+				// anything else is global unicast
+				luxAddr.Type = LuxNetAddrType6GUA
+			}
+		} else {
+			// got IPv4
+			luxAddr.Type = LuxNetAddrType4
+		}
+
+		luxAddr.Addr = proto.LuxProtoIPToAddr(ip)
+
+		luxNet.Addrs = append(luxNet.Addrs, luxAddr)
+	}
+
+	return luxNet, nil
+}
+
+type LuxOptionNetIf struct {
+	Interfaces map[string]*LuxNetInterface
+}
+
+func EnumerateLuxNetInterfaces() (LuxOptionNetIf, error) {
+	opt := LuxOptionNetIf{
+		make(map[string]*LuxNetInterface),
+	}
+
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return opt, err
+	}
+
+	for _, iface := range ifaces {
+		netif, err := NewLuxNetInterface(&iface)
+		if err != nil {
+			return opt, nil
+		}
+
+		opt.Interfaces[netif.Name] = &netif
+	}
+
+	return opt, nil
+}