From 15a913643edab26206c4a444691150edb79022ea Mon Sep 17 00:00:00 2001
From: GnomeZworc <nicolas.boufidjeline@g3e.fr>
Date: Sun, 11 Jan 2026 18:38:02 +0100
Subject: [PATCH] f-14: code: add a new package internal #14

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>
---
 internal/netif/veth.go | 48 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 internal/netif/veth.go

diff --git a/internal/netif/veth.go b/internal/netif/veth.go
new file mode 100644
index 0000000..0056c60
--- /dev/null
+++ b/internal/netif/veth.go
@@ -0,0 +1,48 @@
+package netif
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/vishvananda/netlink"
+	"github.com/vishvananda/netns"
+)
+
+func CreateVethToNetns(rootIf, nsIf, netnsPath string, mtu int) error {
+	// Obligatoire : netns lié au thread
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	// Ouvrir le netns cible
+	ns, err := netns.GetFromPath(netnsPath)
+	if err != nil {
+		return fmt.Errorf("open netns: %w, %s", err, netnsPath)
+	}
+	defer ns.Close()
+
+	// Créer le veth dans le netns courant
+	veth := &netlink.Veth{
+		LinkAttrs: netlink.LinkAttrs{
+			Name: rootIf,
+			MTU:  mtu,
+		},
+		PeerName: nsIf,
+	}
+
+	if err := netlink.LinkAdd(veth); err != nil {
+		return fmt.Errorf("link add: %w", err)
+	}
+
+	// Récupérer l'interface peer
+	peer, err := netlink.LinkByName(nsIf)
+	if err != nil {
+		return fmt.Errorf("peer not found: %w", err)
+	}
+
+	// Déplacer le peer dans le netns cible
+	if err := netlink.LinkSetNsFd(peer, int(ns)); err != nil {
+		return fmt.Errorf("set ns: %w", err)
+	}
+
+	return nil
+}