dhclientv6: Add DHCPv6 support via dhclientbug450326

This adds DHCPv6 support to OpenRC in Linux using dhclient as outlined
by Stuart Longland at <http://stuartl.longlandclan.yi.org/blog/2011/02/15/gentoo-and-dhcpv6/>.
The main place where the new support is added is via a modified copy of
the dhclient.sh script that:

- Renames functions using a 'v6' suffix
- Uses a different pid file
- Uses the '-6' argument when invoking dhclient
- Recognizes new DHCPv6-specific configuration variables with a fallback
  to the DHCP configuration variables.

Additionally:

1. The iproute2 and Linux ifconfig scripts have been ammended to be able
to return IPv6 addresses using new '_get_inet6_address' and
'_get_inet6_addresses' functions.

2. The 'net.lo' init script now has a '_show_address6' function.

3. The documentation in the Linux net.example now contains some DHCPv6
information.

Reported-by: Dustin C. Hatch <admiralnemo@gmail.com>
X-Gentoo-Bug: 150908
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=150908
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/net/iproute2.sh b/net/iproute2.sh
index 096e724..ed5750f 100644
--- a/net/iproute2.sh
+++ b/net/iproute2.sh
@@ -84,8 +84,16 @@ _set_mac_address()
 
 _get_inet_addresses()
 {
-	LC_ALL=C ip -family inet addr show "${IFACE}" | \
-	sed -n -e 's/.*inet \([^ ]*\).*/\1/p'
+	local family="$1";
+	if [ -z "$family" ]; then
+		family="inet"
+	fi
+	LC_ALL=C ip -family $family addr show "${IFACE}" | \
+	sed -n -e 's/.*inet6\? \([^ ]*\).*/\1/p'
+}
+
+_get_inet6_addresses() {
+	_get_inet_addresses "inet6"
 }
 
 _get_inet_address()
@@ -95,6 +103,13 @@ _get_inet_address()
 	echo "$1"
 }
 
+_get_inet6_address()
+{
+	set -- $(_get_inet6_addresses)
+	[ $# = "0" ] && return 1
+	echo "$1"
+}
+
 _add_address()
 {
 	if [ "$1" = "127.0.0.1/8" -a "${IFACE}" = "lo" ]; then