From 348eb4aee32b127480087826b5f55ce0c2bb4cbf Mon Sep 17 00:00:00 2001
From: GnomeZworc <nicolas.boufidjeline@g3e.fr>
Date: Sun, 28 Dec 2025 14:57:36 +0100
Subject: [PATCH] f-8: code: implemete netns first code #8

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>
---
 go.mod                        |  6 ++++--
 go.sum                        |  2 ++
 internal/netns/enter.go       |  5 +++++
 internal/netns/enter_linux.go | 26 ++++++++++++++++++++++++++
 internal/netns/enter_other.go |  8 ++++++++
 5 files changed, 45 insertions(+), 2 deletions(-)
 create mode 100644 internal/netns/enter.go
 create mode 100644 internal/netns/enter_linux.go
 create mode 100644 internal/netns/enter_other.go

diff --git a/go.mod b/go.mod
index 555ca1b..26bd137 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,8 @@
 module git.g3e.fr/syonad/two
 
-go 1.23.8
+go 1.24.0
+
+toolchain go1.24.11
 
 require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
@@ -29,7 +31,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.37.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/net v0.41.0 // indirect
-	golang.org/x/sys v0.34.0 // indirect
+	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
 	google.golang.org/protobuf v1.36.6 // indirect
 )
diff --git a/go.sum b/go.sum
index f61e769..0d19489 100644
--- a/go.sum
+++ b/go.sum
@@ -53,6 +53,8 @@ golang.org/x/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
 golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
 golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
 golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY=
diff --git a/internal/netns/enter.go b/internal/netns/enter.go
new file mode 100644
index 0000000..68ea372
--- /dev/null
+++ b/internal/netns/enter.go
@@ -0,0 +1,5 @@
+package netns
+
+func Enter(name string) error {
+	return enter(name)
+}
diff --git a/internal/netns/enter_linux.go b/internal/netns/enter_linux.go
new file mode 100644
index 0000000..04e116a
--- /dev/null
+++ b/internal/netns/enter_linux.go
@@ -0,0 +1,26 @@
+//go:build linux
+
+package netns
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+
+	"golang.org/x/sys/unix"
+)
+
+func enter(name string) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	path := fmt.Sprintf("/var/run/netns/%s", name)
+
+	f, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	return unix.Setns(int(f.Fd()), unix.CLONE_NEWNET)
+}
diff --git a/internal/netns/enter_other.go b/internal/netns/enter_other.go
new file mode 100644
index 0000000..2691ff2
--- /dev/null
+++ b/internal/netns/enter_other.go
@@ -0,0 +1,8 @@
+//go:build !linux
+
+package netns
+
+func enter(name string) error {
+	// Ignoré hors Linux
+	return nil
+}