[Buildroot] [PATCH 0/2] Alternative way to wait interfaces on bootup

[Buildroot] [PATCH 0/2] Alternative way to wait interfaces on bootup

[Jérôme Pouiller]

As discussed here:

   http://lists.busybox.net/pipermail/buildroot/2015-October/142329.html   
   
v2:
  - Squash patches 2 and 3
  - Remove blank lines
  - Do not print anything if interface already exist
  - Change displayed information

Notice I did not handled case where IFACE=--all. Indeed IF_WAIT_DELAY
is not set in this case won't be set (and none of scripts provided by
ifupdown/ifupdown-extra packages have special handling for '--all'.)

I don't print any explicit error message in case failure. Indeed,
ifupdown/run-parts already print messages and I believe 
"Waiting for interface dummy0 to appear... timeout!" is explicit enough.

   
J?r?me Pouiller (2):
  Revert "package/initscripts: S40network: wait for network interfaces
    to appear"
  skeleton: optionally wait for network interfaces to appear

 package/initscripts/init.d/S40network              | 29 ----------------------
 package/skeleton/skeleton.mk                       |  1 +
 system/skeleton/etc/network/if-pre-up.d/wait_iface | 21 ++++++++++++++++
 3 files changed, 22 insertions(+), 29 deletions(-)
 create mode 100755 system/skeleton/etc/network/if-pre-up.d/wait_iface

-- 
2.1.4

[Buildroot] [PATCH 1/2] Revert "package/initscripts: S40network: wait for network interfaces to appear"

[Jérôme Pouiller]

This reverts commit 49964858f45d2243c513e6d362e992ad89ec7a45. It is
going to be replaced with an ifup hook in next patch.

Signed-off-by: J?r?me Pouiller <jezz@sysmic.org>
---
 package/initscripts/init.d/S40network | 29 -----------------------------
 1 file changed, 29 deletions(-)

diff --git a/package/initscripts/init.d/S40network b/package/initscripts/init.d/S40network
index a8d7c5d..7b11d8b 100755
--- a/package/initscripts/init.d/S40network
+++ b/package/initscripts/init.d/S40network
@@ -6,37 +6,8 @@
 # Debian ifupdown needs the /run/network lock directory
 mkdir -p /run/network
 
-# In case we have a slow-to-appear interface (e.g. eth-over-USB),
-# and we need to configure it, wait until it appears, but not too
-# long either. WAIT_DELAY is in seconds.
-WAIT_DELAY=15
-
-wait_for_interfaces() {
-	IFACES=$(awk '/^auto/ { print $2 }' /etc/network/interfaces)
-	[ -n "$IFACES" ] || return
-
-	printf "Waiting for network interfaces to appear"
-
-	for i in $(seq $WAIT_DELAY); do
-	    for IFACE in $IFACES; do
-		if [ ! -e "/sys/class/net/$IFACE" ]; then
-		    printf "."
-		    sleep 1
-		    continue 2
-		fi
-	    done
-
-	    printf " ok\n"; return
-	done
-
-	printf " timeout\n"
-	exit 1
-}
-
 case "$1" in
   start)
-	wait_for_interfaces
-
  	echo "Starting network..."
 	/sbin/ifup -a
 	;;
-- 
2.1.4

[Buildroot] [PATCH 2/2] skeleton: optionally wait for network interfaces to appear

[Jérôme Pouiller]

This patch has same purpose than 49964858f45d2243c513e6d362e992ad89ec7a45:

  On some machines, the network interface is slow to appear. For example,
  on the Raspberry Pi, the network interface eth0 is an ethernet-over-USB,
  and our standard boot process is too fast, so our network startup script
  is called before the USB bus is compeltely enumerated, thus it can't
  configure eth0.

  Closes #8116.

However, wait-delay hook is enabled only if wait-delay property appears
in /etc/network/interfaces. This patch enable it automaticaly when
interface is configured through DHCP at bootup. But, if user choose
to write /etc/network/interface himself, he have to explicitly
set wait-delay.

Signed-off-by: J?r?me Pouiller <jezz@sysmic.org>
---
 package/skeleton/skeleton.mk                       |  1 +
 system/skeleton/etc/network/if-pre-up.d/wait_iface | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100755 system/skeleton/etc/network/if-pre-up.d/wait_iface

diff --git a/package/skeleton/skeleton.mk b/package/skeleton/skeleton.mk
index 920d3b4..d1b797d 100644
--- a/package/skeleton/skeleton.mk
+++ b/package/skeleton/skeleton.mk
@@ -89,6 +89,7 @@ define SET_NETWORK_DHCP
 		echo ;                                               \
 		echo "auto $(NETWORK_DHCP_IFACE)";                   \
 		echo "iface $(NETWORK_DHCP_IFACE) inet dhcp";        \
+		echo "	wait-delay 15";                              \
 	) >> $(TARGET_DIR)/etc/network/interfaces
 endef
 endif
diff --git a/system/skeleton/etc/network/if-pre-up.d/wait_iface b/system/skeleton/etc/network/if-pre-up.d/wait_iface
new file mode 100755
index 0000000..f4a1c4c
--- /dev/null
+++ b/system/skeleton/etc/network/if-pre-up.d/wait_iface
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# In case we have a slow-to-appear interface (e.g. eth-over-USB),
+# and we need to configure it, wait until it appears, but not too
+# long either. IF_WAIT_DELAY is in seconds.
+
+if [ "${IF_WAIT_DELAY}" && ! -e "/sys/class/net/${IFACE}" ]; then
+    printf "Waiting for interface %s to appear" "${IFACE}"
+    while [ ${IF_WAIT_DELAY} -gt 0 ]; do
+        if [ -e "/sys/class/net/${IFACE}" ]; then
+            printf "\n"
+            exit 0
+        fi
+        sleep 1
+        printf "."
+        : $((IF_WAIT_DELAY -= 1))
+    done
+    printf " timeout!\n"
+    exit 1
+fi
+
-- 
2.1.4

[Buildroot] [PATCH 0/2] Alternative way to wait interfaces on bootup

[Jérôme Pouiller]

On Thursday 29 October 2015 09:51:54 J?r?me Pouiller wrote:
> As discussed here:
> 
>   
> http://lists.busybox.net/pipermail/buildroot/2015-October/142329.html
> 
> v2:
Arf... I forgot "v2" in subject. Sorry.

-- 
J?r?me Pouiller, Sysmic
Embedded Linux specialist
http://www.sysmic.fr