[PATCH] connman: fix race condition with systemd-udev

[Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>]

When a new USB network interface is plugged in systemd
fails to rename the new interface (ethX) to a predictable
name [1] because connman locks it first.

The proposed solution is to blacklist unpredictable names
in connman in case systemd is used as an init system.
Also add a fix to connman that makes it to re-evaluate
a known but blacklisted ethernet interface for enabling
after it has got renamed.

Fixes [YOCTO #11341]

[1] https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/

Signed-off-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
---
 ...try-to-add-ether-interface-after-renaming.patch | 42 ++++++++++++++++++++++
 .../recipes-connectivity/connman/connman/main.conf |  2 ++
 meta/recipes-connectivity/connman/connman_1.33.bb  | 10 ++++++
 3 files changed, 54 insertions(+)
 create mode 100644 meta/recipes-connectivity/connman/connman/0001-rtnl-retry-to-add-ether-interface-after-renaming.patch
 create mode 100644 meta/recipes-connectivity/connman/connman/main.conf

diff --git a/meta/recipes-connectivity/connman/connman/0001-rtnl-retry-to-add-ether-interface-after-renaming.patch b/meta/recipes-connectivity/connman/connman/0001-rtnl-retry-to-add-ether-interface-after-renaming.patch
new file mode 100644
index 0000000..e5f4360
--- /dev/null
+++ b/meta/recipes-connectivity/connman/connman/0001-rtnl-retry-to-add-ether-interface-after-renaming.patch
@@ -0,0 +1,42 @@
+From d92e713e112e48cb4434f1c67b97e6507a7cf9e8 Mon Sep 17 00:00:00 2001
+From: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
+Date: Thu, 20 Apr 2017 15:54:29 +0300
+Subject: [PATCH] rtnl: retry to add ether interface after renaming
+
+If eth* interfaces are blacklisted to avoid a race condition
+where connman may access an interface before systemd/udev can
+change it to use a predictable interface name then it's impossible
+to re-activate it under a new predictable name because an existing
+interface is considered to be already added to the technology.
+
+Once blacklisted an interface is not re-evaluated under a new name.
+
+This patch allows to re-evaluate an interface known to connman for
+adding it to the ethernet technology in case it's name has changed.
+E.g. after unplugging a cable and plugging it back.
+
+Upstream-Status: Submitted [https://lists.01.org/pipermail/connman/2017-April/021790.html]
+
+Signed-off-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
+---
+ src/rtnl.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/src/rtnl.c b/src/rtnl.c
+index d1b851f..19a999c 100644
+--- a/src/rtnl.c
++++ b/src/rtnl.c
+@@ -469,7 +469,9 @@ static void process_newlink(unsigned short type, int index, unsigned flags,
+ 
+ 		if (type == ARPHRD_ETHER)
+ 			read_uevent(interface);
+-	} else
++	} else if (type == ARPHRD_ETHER && interface->device_type == CONNMAN_DEVICE_TYPE_UNKNOWN)
++		read_uevent(interface);
++	else
+ 		interface = NULL;
+ 
+ 	for (list = rtnl_list; list; list = list->next) {
+-- 
+2.9.3
+
diff --git a/meta/recipes-connectivity/connman/connman/main.conf b/meta/recipes-connectivity/connman/connman/main.conf
new file mode 100644
index 0000000..fcd6ca0
--- /dev/null
+++ b/meta/recipes-connectivity/connman/connman/main.conf
@@ -0,0 +1,2 @@
+[General]
+NetworkInterfaceBlacklist=vmnet,vboxnet,virbr,ifb,docker,veth,eth,wlan
diff --git a/meta/recipes-connectivity/connman/connman_1.33.bb b/meta/recipes-connectivity/connman/connman_1.33.bb
index 4129b05..02247cb 100644
--- a/meta/recipes-connectivity/connman/connman_1.33.bb
+++ b/meta/recipes-connectivity/connman/connman_1.33.bb
@@ -1,5 +1,7 @@
 require connman.inc
 
+OVERRIDES_append = "${@bb.utils.contains('DISTRO_FEATURES', 'systemd', ':systemd', '', d)}"
+
 SRC_URI  = "${KERNELORG_MIRROR}/linux/network/${BPN}/${BP}.tar.xz \
             file://0001-plugin.h-Change-visibility-to-default-for-debug-symb.patch \
             file://connman \
@@ -9,8 +11,16 @@ SRC_URI  = "${KERNELORG_MIRROR}/linux/network/${BPN}/${BP}.tar.xz \
             "
 SRC_URI_append_libc-musl = " file://0002-resolve-musl-does-not-implement-res_ninit.patch \
                              file://0001-Fix-compile-on-musl-with-kernel-4.9-headers.patch"
+SRC_URI_append_systemd = "   file://0001-rtnl-retry-to-add-ether-interface-after-renaming.patch \
+                             file://main.conf"
+
 
 SRC_URI[md5sum] = "c51903fd3e7a6a371d12ac5d72a1fa01"
 SRC_URI[sha256sum] = "bc8946036fa70124d663136f9f6b6238d897ca482782df907b07a428b09df5a0"
 
+do_install_append_systemd() {
+    install -d ${D}${sysconfdir}/connman
+    install -m 0644 ${WORKDIR}/main.conf ${D}${sysconfdir}/connman/main.conf
+}
+
 RRECOMMENDS_${PN} = "connman-conf"
-- 
2.9.3