treewide: replace IP string manipulation by owipcalc tool

The owipcalc tool provides an "add" algorithm which can be used
to concateneted IPv6 addresses from prefix and suffix.

Since it's available upstream and our string manipulation is ugly,
let's replace our IP concatenation with that tool. The package
consists of a single .c file with about 1000 lines resulting in
about 4 kB for the ipk package.

This patch does _not_ introduce any conceptual changes yet. Thus,
the "wrong" IPv6 prefix from KeyXchange will be expected in the
same format, it is just healed for the new code for now.

The change allows to get rid of some bloat, i.e. some quite trivial
custom functions on the way. This also drops the ipTidyColon()
function, as owipcalc seems to return the collapsed version by default.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Reviewed-by: Fabian Bläse <fabian@blaese.de>

src/packages/fff/fff-hoods/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fff-hoods
-PKG_RELEASE:=17
+PKG_RELEASE:=18
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)
 
@@ -22,6 +22,7 @@ define Package/$(PKG_NAME)
 		+fff-web-hood \
 		+fff-wireless \
 		+jshn \
+		+owipcalc \
 		+@BUSYBOX_CONFIG_WGET \
 		+@BUSYBOX_CONFIG_FEATURE_WGET_TIMEOUT
 endef

src/packages/fff/fff-hoods/files/usr/sbin/configurehood

@@ -189,12 +189,13 @@ if [ -s "$hoodfiletmp" ]; then
 	json_get_var prefix ula_prefix
 	# Set $prefix::MAC as IP
 	if [ -n "$prefix" ] ; then
-		prefix="$(echo "$prefix" | sed -e 's,\\,,')"
-		mac="$(cat "/sys/class/net/br-client/address")"
-		addr="$(ipMacAssemble "$prefix" "$mac")"
-		addr="$(ipTidyColon "$addr")"
-		addr_eui="$(ipEUIAssemble "$prefix" "$mac")"
-		addr_eui="$(ipTidyColon "$addr_eui")"
+		# remove escape character
+		prefix=$(echo "$prefix" | sed -e 's,\\,,')
+		# create proper prefix
+		prefix=$(echo "$prefix" | sed -e 's,/,:/,')
+		mac=$(cat "/sys/class/net/br-client/address")
+		addr=$(owipcalc "$prefix" add "::$(ipMacSuffix "$mac")")
+		addr_eui=$(owipcalc "$prefix" add "::$(ipEUISuffix "$mac")")
 		for ip in $(ip -6 addr show dev br-client | grep inet6 | grep -v -e " $addr" -e " $addr_eui" -e " fe80::" -e " fdff::" | cut -f6 -d " "); do
 			ip -6 addr del "$ip" dev br-client
 		done

src/packages/fff/fff-network/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fff-network
-PKG_RELEASE:=27
+PKG_RELEASE:=28
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)
 
@@ -12,7 +12,10 @@ define Package/$(PKG_NAME)
 	CATEGORY:=Freifunk
 	TITLE:=Freifunk-Franken network configuration
 	URL:=http://www.freifunk-franken.de
-	DEPENDS:=+fff-boardname +fff-firewall
+	DEPENDS:= \
+		+owipcalc \
+		+fff-boardname \
+		+fff-firewall
 endef
 
 define Package/$(PKG_NAME)/description

src/packages/fff/fff-network/files/lib/functions/fff/network

@@ -29,62 +29,6 @@ ipEUISuffix() {
 	return 0
 }
 
-ipAssemble() {
-	# Concatenates a prefix (1st argument) and a suffix (2nd argument) to a merged IPv6 address
-	# (The prefix has to bear the subnet: fdff::/64)
-	# (The prefix must only contain the higher 64 bits (correct: 0:0:0:0: or 0:: - wrong: 0:0:0:0::)
-
-	[ $# -ne "2" ] && return 1
-
-	local prefix=$1
-	local suffix=$2
-
-	echo "$prefix" | sed -e 's,/,'$suffix'/,'
-	return 0
-}
-
-ipMacAssemble() {
-	# Concatenates a prefix (1st argument) and a MAC-based suffix (MAC address as 2nd argument) to a merged IPv6 address
-	# (Details on prefix: Check ipAssemble(), details on suffix: Check ipMacSuffix())
-
-	[ $# -ne "2" ] && return 1
-
-	local prefix=$1
-	local mac=$2
-
-	suffix="$(ipMacSuffix "$mac")"
-	ipAssemble "$prefix" "$suffix"
-	return 0
-}
-
-ipEUIAssemble() {
-	# Concatenates a prefix (1st argument) and an EUI-based suffix (MAC address as 2nd argument) to a merged IPv6 address
-	# (Details on prefix: Check ipAssemble(), details on suffix: Check ipEUISuffix())
-
-	[ $# -ne "2" ] && return 1
-
-	local prefix=$1
-	local mac=$2
-
-	suffix="$(ipEUISuffix "$mac")"
-	ipAssemble "$prefix" "$suffix"
-	return 0
-}
-
-ipTidyColon() {
-	# Collapses zeros to :: to yield short but valid IPv6 addresses
-	#
-	# Argument: IPv6 address to be shortened
-
-	[ $# -ne "1" ] && return 1
-
-	local addr=$1
-
-	echo "$addr" | grep -q "::" || addr="$(echo "$addr" | sed -e 's,:[0:]*:,::,')"
-	echo "$addr"
-	return 0
-}
-
 macFlipLocalBit() {
 	# Returns given MAC-address with locally administered bit flipped
 	#

src/packages/fff/fff-network/files/usr/sbin/configurenetwork

@@ -195,9 +195,9 @@ else
         ip -6 addr del $ip dev br-client
     done
 
-    prefix="fdff:0::/64"
+    prefix="fdff::/64"
     # Set $prefix::MAC as IP
-    addr="$(ipMacAssemble "$prefix" "$ROUTERMAC")"
+    addr=$(owipcalc "$prefix" add "::$(ipMacSuffix "$ROUTERMAC")")
     ip -6 addr add $addr dev br-client
 
     uci -q del network.globals
@@ -207,12 +207,12 @@ else
     uci -q set network.client.proto=static
 
     # Set $prefix::1 as IP
-    addr="$(ipAssemble "$prefix" "1")"
+    addr=$(owipcalc "$prefix" add ::1)
     ip -6 addr add $addr dev br-client
     uci -q add_list network.client.ip6addr=$addr
 
     # Set $prefix::link-local as IP
-    addr="$(ipEUIAssemble "$prefix" "$ROUTERMAC")"
+    addr=$(owipcalc "$prefix" add "::$(ipEUISuffix "$ROUTERMAC")")
     ip -6 addr add $addr dev br-client
     uci -q add_list network.client.ip6addr=$addr
 

src/packages/fff/fff-wireguard/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fff-wireguard
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/fff-wireguard
 
@@ -12,9 +12,11 @@ define Package/fff-wireguard
 	CATEGORY:=Freifunk
 	TITLE:=Freifunk-Franken wireguard
 	URL:=https://www.freifunk-franken.de
-	DEPENDS:=+wireguard \
-			 +fff-network \
-			 +fff-babeld
+	DEPENDS:= \
+		+owipcalc \
+		+wireguard \
+		+fff-babeld \
+		+fff-network
 endef
 
 define Package/fff-wireguard/description

src/packages/fff/fff-wireguard/files/etc/layer3.d/50-wireguard

@@ -116,7 +116,7 @@ configure() {
 		uci -q del network.$prefixname.addresses
 
 		# add link local address
-		uci add_list network.$prefixname.addresses="$(ipEUIAssemble "fe80::/64" "$ROUTERMAC")"
+		uci add_list network.$prefixname.addresses="$(owipcalc "fe80::/64" add "::$(ipEUISuffix "$ROUTERMAC")")"
 
 		# add peer_ip
 		babel_add_peeraddr "network.$prefixname.addresses"