From 35f2972e9832d02fde1bd4957bc0a3a8a5996299 Mon Sep 17 00:00:00 2001
From: Benjamin Collet <ben@clt.tf>
Date: Sat, 7 Apr 2018 21:40:38 +0200
Subject: [PATCH] Initial commit

---
 LICENSE           | 23 +++++++++++++++++++++++
 README            | 19 +++++++++++++++++++
 if-down.d/netns   | 15 +++++++++++++++
 if-pre-up.d/netns | 20 ++++++++++++++++++++
 if-up.d/netns     | 13 +++++++++++++
 5 files changed, 90 insertions(+)
 create mode 100644 LICENSE
 create mode 100644 README
 create mode 100755 if-down.d/netns
 create mode 100755 if-pre-up.d/netns
 create mode 100755 if-up.d/netns

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..534eb0c
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,23 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 m0kct
+Copyright (c) 2018 Benjmin Collet
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
diff --git a/README b/README
new file mode 100644
index 0000000..28481bf
--- /dev/null
+++ b/README
@@ -0,0 +1,19 @@
+# ifupdown-netns
+
+Some simple scripts to simplify configuring network namespaces on Debian-like
+systems.  Copy them into the corresponding directories under `/etc/network`.
+
+To configure an interface in a namespace:
+
+```
+auto eth1
+iface eth1 inet manual
+  netns myns
+```
+
+On invocation of `ifup` it will create the necessary directories under
+`/etc/netns/` and an empty `/etc/netns/<namespace>/network/interfaces` file if
+it doesn't already exist.
+
+If it does and the interface is configured it will invoke `ifup` inside the
+namespace.
diff --git a/if-down.d/netns b/if-down.d/netns
new file mode 100755
index 0000000..efb8f8e
--- /dev/null
+++ b/if-down.d/netns
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+set -e
+
+if [ -n "${IF_NETNS}" ]
+then
+  unshare -m /bin/sh <<-EOF
+mount --make-rprivate /
+mount --bind /run/network.${IF_NETNS} /run/network
+if (ip netns exec ${IF_NETNS} ifquery --list | grep -qx ${IFACE}); then
+  ip netns exec ${IF_NETNS} ifdown ${IFACE}
+fi
+ip netns exec ${IF_NETNS} ip link set netns 1 dev ${IFACE}
+EOF
+fi
diff --git a/if-pre-up.d/netns b/if-pre-up.d/netns
new file mode 100755
index 0000000..7a14ca7
--- /dev/null
+++ b/if-pre-up.d/netns
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -e
+
+if [ -n "${IF_NETNS}" ]
+then
+  # Create netns if it doesn't already exist, and bring up the loopback
+  if ! (ip netns list | grep -qx ${IF_NETNS})
+  then
+    mkdir -p /etc/netns/$IF_NETNS/network/{if-down.d,if-post-down.d,if-pre-up.d,if-up.d}
+    if [ ! -f /etc/netns/$IF_NETNS/network/interfaces ]; then
+      touch /etc/netns/$IF_NETNS/network/interfaces
+    fi
+    mkdir -p /run/network.${IF_NETNS}
+    rm -rf /run/network.${IF_NETNS}/*
+    ip netns add ${IF_NETNS}
+    ip netns exec ${IF_NETNS} ip link set lo up
+  fi
+  ip link set ${IFACE} netns ${IF_NETNS}
+fi
diff --git a/if-up.d/netns b/if-up.d/netns
new file mode 100755
index 0000000..d7ae715
--- /dev/null
+++ b/if-up.d/netns
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+set -e
+
+if [ -n "${IF_NETNS}" ]; then
+  unshare -m /bin/sh <<-EOF
+mount --make-rprivate /
+mount --bind /run/network.${IF_NETNS} /run/network
+if (ip netns exec ${IF_NETNS} ifquery --list | grep -qx ${IFACE}); then
+  ip netns exec ${IF_NETNS} ifup ${IFACE}
+fi
+EOF
+fi