[PATCH] fff-network/fff-hoods: Create functions for IPv6 rewriting

[Adrian Schmutzler]

This puts the code for creating IPv6 addresses from MAC
address and EUI into functions, so it can be reused.

This should be particularly helpful if code is rewritten later.

Signed-off-by: Adrian Schmutzler <freifunk at adrianschmutzler.de>

Tested-by: Adrian Schmutzler <freifunk at adrianschmutzler.de>
---
 .../fff/fff-hoods/files/usr/sbin/configurehood     | 11 ++--
 .../fff-network/files/lib/functions/fff/network    | 63 ++++++++++++++++++++++
 .../fff-network/files/usr/sbin/configurenetwork    | 11 ++--
 3 files changed, 73 insertions(+), 12 deletions(-)
 create mode 100644 src/packages/fff/fff-network/files/lib/functions/fff/network

diff --git a/src/packages/fff/fff-hoods/files/usr/sbin/configurehood b/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
index 88c0daa..e60812d 100755
--- a/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
+++ b/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
@@ -1,6 +1,7 @@
 #!/bin/sh
 
 . /usr/share/libubox/jshn.sh
+. /lib/functions/fff/network
 . /lib/functions/fff/wireless
 . /lib/functions/fff/timeserver
 
@@ -205,12 +206,10 @@ if [ -s /tmp/keyxchangev2data ]; then
 	# Set $prefix::MAC as IP
 	if [ -n "$prefix" ] ; then
 		prefix="$(echo "$prefix" | sed -e 's,\\,,')"
-		suffix="$(awk -F: '{ print "0:"$1$2":"$3$4":"$5$6 }' /sys/class/net/br-mesh/address)"
-		suffix_eui="$(awk -F: '{ printf("%02x%s:%sff:fe%s:%s%s\n", xor(("0x"$1),2), $2, $3, $4, $5, $6) }' /sys/class/net/br-mesh/address)"
-		addr="$(echo "$prefix" | sed -e 's,/,'$suffix'/,')"
-		echo $addr | grep -q "::" || addr="$(echo "$addr" | sed -e 's,:[0:]*:,::,')"
-		addr_eui="$(echo "$prefix" | sed -e 's,/,'$suffix_eui'/,')"
-		echo $addr_eui | grep -q "::" || addr_eui="$(echo "$addr_eui" | sed -e 's,:[0:]*:,::,')"
+		addr="$(ipMacAssemble "$prefix" "br-mesh")"
+		addr="$(ipTidyColon "$addr")"
+		addr_eui="$(ipEUIAssemble "$prefix" "br-mesh")"
+		addr_eui="$(ipTidyColon "$addr_eui")"
 		for ip in $(ip -6 addr show dev br-mesh | grep inet6 | grep -v -e " $addr" -e " $addr_eui" -e " fe80::" -e " fdff::" | cut -f6 -d " "); do
 			ip -6 addr del "$ip" dev br-mesh
 		done
diff --git a/src/packages/fff/fff-network/files/lib/functions/fff/network b/src/packages/fff/fff-network/files/lib/functions/fff/network
new file mode 100644
index 0000000..f16d671
--- /dev/null
+++ b/src/packages/fff/fff-network/files/lib/functions/fff/network
@@ -0,0 +1,63 @@
+#!/bin/sh
+# Copyright 2017 Adrian Schmutzler
+# License GPLv3
+
+ipMacSuffix() {
+	[ $# -ne "1" ] && return 1
+
+	local iface=$1
+
+	awk -F: '{ print "0:"$1$2":"$3$4":"$5$6 }' "/sys/class/net/${iface}/address"
+	return 0
+}
+
+ipEUISuffix() {
+	[ $# -ne "1" ] && return 1
+
+	local iface=$1
+
+	awk -F: '{ printf("%02x%s:%sff:fe%s:%s%s\n", xor(("0x"$1),2), $2, $3, $4, $5, $6) }' "/sys/class/net/${iface}/address"
+	return 0
+}
+
+ipAssemble() {
+	[ $# -ne "2" ] && return 1
+
+	local prefix=$1
+	local suffix=$2
+
+	echo "$prefix" | sed -e 's,/,'$suffix'/,'
+	return 0
+}
+
+ipMacAssemble() {
+	[ $# -ne "2" ] && return 1
+
+	local prefix=$1
+	local iface=$2
+
+	suffix="$(ipMacSuffix "$iface")"
+	ipAssemble "$prefix" "$suffix"
+	return 0
+}
+
+ipEUIAssemble() {
+	[ $# -ne "2" ] && return 1
+
+	local prefix=$1
+	local iface=$2
+
+	suffix="$(ipEUISuffix "$iface")"
+	ipAssemble "$prefix" "$suffix"
+	return 0
+}
+
+ipTidyColon() {
+	[ $# -ne "1" ] && return 1
+
+	local addr=$1
+
+	echo "$addr" | grep -q "::" || addr="$(echo "$addr" | sed -e 's,:[0:]*:,::,')"
+	echo "$addr"
+	return 0
+}
diff --git a/src/packages/fff/fff-network/files/usr/sbin/configurenetwork b/src/packages/fff/fff-network/files/usr/sbin/configurenetwork
index c6b3113..d4866e4 100755
--- a/src/packages/fff/fff-network/files/usr/sbin/configurenetwork
+++ b/src/packages/fff/fff-network/files/usr/sbin/configurenetwork
@@ -9,6 +9,8 @@
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 
+. /lib/functions/fff/network
+
 BOARD="$(uci get board.model.name)"
 . /etc/network.$BOARD
 
@@ -218,8 +220,7 @@ else
 
     prefix="fdff:0::/64"
     # Set $prefix::MAC as IP
-    suffix=$(awk -F: '{ print $1$2":"$3$4":"$5$6 }' /sys/class/net/br-mesh/address)
-    addr=$(echo $prefix | sed -e 's/\//'$suffix'\//')
+    addr="$(ipMacAssemble "$prefix" "br-mesh")"
     ip -6 addr add $addr dev br-mesh
 
     uci -q del network.globals
@@ -229,14 +230,12 @@ else
     uci -q set network.mesh.proto=static
 
     # Set $prefix::1 as IP
-    suffix="1"
-    addr=$(echo $prefix | sed -e 's/\//'$suffix'\//')
+    addr="$(ipAssemble "$prefix" "1")"
     ip -6 addr add $addr dev br-mesh
     uci -q add_list network.mesh.ip6addr=$addr
 
     # Set $prefix::link-local as IP
-    suffix=$(awk -F: '{ printf("%02x%s:%sff:fe%s:%s%s\n", xor(("0x"$1),2), $2, $3, $4, $5, $6) }' /sys/class/net/br-mesh/address)
-    addr=$(echo $prefix | sed -e 's/\//'$suffix'\//')
+    addr="$(ipEUIAssemble "$prefix" "br-mesh")"
     ip -6 addr add $addr dev br-mesh
     uci -q add_list network.mesh.ip6addr=$addr
 
-- 
2.7.4