From 9e1d4865cb618eac014782f1c470f666c69b4338 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Fri, 1 May 2020 23:39:43 -0600
Subject: uapi: linux: put sock files in netns-specific subdir

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 ipc/uapi_linux.go | 42 ++++++++++++++++++++++++++++++------------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/ipc/uapi_linux.go b/ipc/uapi_linux.go
index a3c95ca..19c1897 100644
--- a/ipc/uapi_linux.go
+++ b/ipc/uapi_linux.go
@@ -13,6 +13,7 @@ import (
 	"path"
 
 	"golang.org/x/sys/unix"
+
 	"golang.zx2c4.com/wireguard/rwcancel"
 )
 
@@ -23,7 +24,8 @@ const (
 	IpcErrorProtocol  = -int64(unix.EPROTO)
 	IpcErrorInvalid   = -int64(unix.EINVAL)
 	IpcErrorPortInUse = -int64(unix.EADDRINUSE)
-	socketName        = "%s.sock"
+	socketNameFmt     = "%s.sock"
+	netnsFmt          = "netns-%d"
 )
 
 type UAPIListener struct {
@@ -63,6 +65,29 @@ func (l *UAPIListener) Addr() net.Addr {
 	return l.listener.Addr()
 }
 
+func currentNetns() (netns uint32, err error) {
+	link, err := os.Readlink("/proc/self/ns/net")
+	if err != nil {
+		return
+	}
+	_, err = fmt.Sscanf(link, "net:[%d]", &netns)
+	return
+}
+
+func ifaceSocketPath(iface string) string {
+	if netns, err := currentNetns(); err == nil {
+		return path.Join(
+			socketDirectory,
+			fmt.Sprintf(netnsFmt, netns),
+			fmt.Sprintf(socketNameFmt, iface),
+		)
+	}
+	return path.Join(
+		socketDirectory,
+		fmt.Sprintf(socketNameFmt, iface),
+	)
+}
+
 func UAPIListen(name string, file *os.File) (net.Listener, error) {
 
 	// wrap file in listener
@@ -82,12 +107,9 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 		connErr:  make(chan error, 1),
 	}
 
-	// watch for deletion of socket
+	socketPath := ifaceSocketPath(name)
 
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
+	// watch for deletion of socket
 
 	uapi.inotifyFd, err = unix.InotifyInit()
 	if err != nil {
@@ -145,21 +167,17 @@ func UAPIListen(name string, file *os.File) (net.Listener, error) {
 }
 
 func UAPIOpen(name string) (*os.File, error) {
+	socketPath := ifaceSocketPath(name)
 
 	// check if path exist
 
-	err := os.MkdirAll(socketDirectory, 0755)
+	err := os.MkdirAll(path.Dir(socketPath), 0755)
 	if err != nil && !os.IsExist(err) {
 		return nil, err
 	}
 
 	// open UNIX socket
 
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
-
 	addr, err := net.ResolveUnixAddr("unix", socketPath)
 	if err != nil {
 		return nil, err
-- 
cgit v1.2.3-54-g00ecf