From 552fb4b8b5aa738959848dafc20d41e6fdbdbe4e Mon Sep 17 00:00:00 2001
From: Arne Fitzenreiter <arne_f@ipfire.org>
Date: Mon, 1 Feb 2016 07:28:03 +0100
Subject: [PATCH] dhcpcd: rework mtu handling on buggy nic's

some nic's loose the carrier after setting new mtu.

Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
---
 config/dhcpc/dhcpcd-hooks/10-mtu             | 31 ++++++++++++++++++++
 config/rootfiles/core/98/filelists/files     |  2 ++
 lfs/dhcpcd                                   |  4 +--
 src/initscripts/init.d/networking/dhcpcd.exe |  7 -----
 4 files changed, 35 insertions(+), 9 deletions(-)
 create mode 100644 config/dhcpc/dhcpcd-hooks/10-mtu

diff --git a/config/dhcpc/dhcpcd-hooks/10-mtu b/config/dhcpc/dhcpcd-hooks/10-mtu
new file mode 100644
index 0000000000..49e05192ba
--- /dev/null
+++ b/config/dhcpc/dhcpcd-hooks/10-mtu
@@ -0,0 +1,31 @@
+# Configure the MTU for the interface
+
+eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
+
+set_mtu()
+{
+	local mtu=$1
+	ip link set "$interface" mtu "$mtu"
+
+	# test for buggy nic that lose link at mtu set...
+	carrier=`cat /sys/class/net/$interface/carrier`
+	if [ "$carrier" == "0" ]; then
+		syslog info "Warning! Carrier loss after MTU set. Reinit ..."
+		ip link set "$interface" down
+		ip link set "$interface" up
+	fi
+}
+if [ -n "$new_interface_mtu" ] && $if_up; then
+	if [ $RED_DHCP_FORCE_MTU -ge 576 ]; then
+		new_interface_mtu=$RED_DHCP_FORCE_MTU
+	fi
+	if [ ! "$new_interface_mtu" == "$ifmtu" ]; then
+		# The smalled MTU dhcpcd can work with is 576
+		if [ "$new_interface_mtu" -gt 576 ]; then
+			if set_mtu "$new_interface_mtu"; then
+				syslog info "MTU set to $new_interface_mtu"
+			fi
+		fi
+	fi
+fi
+
diff --git a/config/rootfiles/core/98/filelists/files b/config/rootfiles/core/98/filelists/files
index 8586e6aab3..ad5d9a7e47 100644
--- a/config/rootfiles/core/98/filelists/files
+++ b/config/rootfiles/core/98/filelists/files
@@ -1,6 +1,7 @@
 etc/system-release
 etc/issue
 etc/rc.d/init.d/firewall
+etc/rc.d/init.d/networking/dhcpcd.exe
 etc/modprobe.d/nf_conntrack.conf
 srv/web/ipfire/cgi-bin/logs.cgi/firewalllog.dat
 srv/web/ipfire/cgi-bin/logs.cgi/firewalllogcountry.dat
@@ -16,3 +17,4 @@ srv/web/ipfire/cgi-bin/webaccess.cgi
 usr/bin/pgrep
 usr/local/bin/qosctrl
 usr/local/bin/timectrl
+var/ipfire/dhcpc/dhcpcd-hooks/10-mtu
diff --git a/lfs/dhcpcd b/lfs/dhcpcd
index ff31821f60..3b9a094ce1 100644
--- a/lfs/dhcpcd
+++ b/lfs/dhcpcd
@@ -85,9 +85,9 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	rm -f $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks/50-yp.conf
 	rm -f $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks/50-ypbind
 
-	sed -i -e "s|-ge 576|-gt 576|g" $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks/10-mtu
-
 	install -m 644 $(DIR_SRC)/config/dhcpc/dhcpcd.conf $(CONFIG_ROOT)/dhcpc/
+	install -m 444 $(DIR_SRC)/config/dhcpc/dhcpcd-hooks/10-mtu $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks
+
 	chown root:root $(CONFIG_ROOT)/dhcpc/dhcpcd.conf
 
 	@rm -rf $(DIR_APP)
diff --git a/src/initscripts/init.d/networking/dhcpcd.exe b/src/initscripts/init.d/networking/dhcpcd.exe
index a7bad47b50..a2cdc66d25 100644
--- a/src/initscripts/init.d/networking/dhcpcd.exe
+++ b/src/initscripts/init.d/networking/dhcpcd.exe
@@ -31,13 +31,6 @@ dhcpcd_up()
 	# Only if RED_TYPE=DHCP update /var/ipfire/red
 	if [ "$RED_TYPE" == "DHCP" ]; then
 
-		#Force MTU option for KabelDeutschland because this ISP
-		#set the MTU to 576 instead of the supportet 1500
-		if [ $RED_DHCP_FORCE_MTU -ge 576 ]; then
-			logger -p local0.info -t dhcpcd.exe[$$] "Force mtu to $RED_DHCP_FORCE_MTU"
-			ip link set $interface mtu $RED_DHCP_FORCE_MTU
-		fi
-
 		#Check if we have to restart the services at update
 		[ ! -e "/var/ipfire/red/active" ] && update=1;
 		if [ "$old_domain_name_service" != "$new_domain_name_service" ]; then
-- 
2.39.2