kdump/kdump-add-IPv6-KDUMP_NETCONFIG-modes.patch

From: Petr Tesarik <ptesarik@suse.cz>
Date: Tue Sep 23 16:12:34 2014 +0200
Subject: Add KDUMP_NETCONFIG modes to support IPv6
References: bnc#885897
Patch-mainline: v0.8.16
Git-commit: 72be4138d5ac03af8c5579099c6a39ab7d272503

KDUMP_NETCONFIG had only two modes: static and dhcp, where dhcp
actually only means DHCP4. New modes are needed to get an IPv6
address on the interface.

Note that automatic configuration (KDUMP_NETCONFIG=auto) still uses
only IPv4, because dracut does not implement multiple alternative
ip configurations, and there's no way to determine in advance
which stack should be used.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>

---
 doc/man/kdump.5.txt.in     |   35 ++++++++++++++++++++++++++++++-----
 init/module-setup.sh       |   42 ++++++++++++++++++++++++++++++++++--------
 init/setup-kdump.functions |   39 ++++++++++++++++++++++++++++++++++++++-
 sysconfig.kdump.in         |    4 ++--
 4 files changed, 104 insertions(+), 16 deletions(-)

--- a/doc/man/kdump.5.txt.in
+++ b/doc/man/kdump.5.txt.in
@@ -513,13 +513,38 @@ KDUMP_NETCONFIG
 
 Network configuration for kdump. Because the dump process runs in initrd, the
 network configuration is different from the normal network configuration. Use
-_auto_ to auto-detect the network configuration, this is also the default.
+_auto_ to auto-detect the network configuration (see *auto* mode below). The
+interface with the default route will be used. This is the default.
+
+Auto-detection cannot be used to set up dual-stack (IPv4 and IPv6) hosts
+because of limitations in the implementation of the _ip=_ initrd command line
+option.
 
 Use a _netdevice:mode_ string to force a specific network device to be used. A
-_netdevice_ is for example "eth0". The _mode_ can be either "dhcp" or "static".
-If you use "static", you have to set the IP address with _ip=ipspec_. _ipspec_
-is <client>:<server>:<gateway>:<netmask>:<hostname>:<device>:<proto>. See
-*mkinitrd*(8) for details.
+_netdevice_ is for example "eth0". The _mode_ can be:
+
+*static*::
+  Always re-use the current configuration of _netdevice_ (both IPv4 and IPv6).
+  Note that only permanent global IPv6 addresses are stored, because temporary
+  addresses are likely to expire before the system crashes, and link-local
+  addresses are set up automatically.
+
+*auto6*::
+  Use IPv6 autoconfiguration to get an address on the interface.
+
+*dhcp*::
+*dhcp4*::
+  Use DHCP to configure an IPv4 address on the interface.
+
+*dhcp6*::
+  Use DHCP6 to configure an IPv6 address on the interface.
+
+*auto*::
+  Select the mode depending on the current state of the interface:
+
+  * use DHCP4 if it has an IPv4 address (IPv6 not set up),
+  * use DHCP6 if it has a permanent IPv6 address (IPv4 not set up),
+  * use IPv6 auto-configuration if it has neither (IPv4 not set up).
 
 You can set KDUMP_NETCONFIG to "" if you want no network in initrd, i.e. you use
 disk dumping.
--- a/init/module-setup.sh
+++ b/init/module-setup.sh
@@ -65,24 +65,50 @@ kdump_cmdline_ip() {
     [ "$kdump_neednet" = y ] || return 0
 
     echo -n "rd.neednet=1"
+
+    local _if _mode
     if [ "$KDUMP_NETCONFIG" = "auto" ] ; then
-	echo -n " ip=any"
+	_if=default
+	_mode=auto
     else
 	set -- ${KDUMP_NETCONFIG//:/ }
 	local _if=$1
 	local _mode=$2
+    fi
 
-	if [ "$_if" = "default" ] ; then
-	    _if=$(kdump_default_netdev)
-	fi
-	printf " %s" $(kdump_ifname_config "$_if")
+    [ "$_if" = "default" ] && _if=$(kdump_default_netdev)
 
-	if [ "$_mode" = "static" ] ; then
-	    printf " %s" $(kdump_ip_config "$_if")
+    printf " %s" $(kdump_ifname_config "$_if")
+
+    if [ "$_mode" = "auto" ] ; then
+	if [ -n $(kdump_ip_config) ] ; then
+	    _mode=dhcp4
+	elif [ -n $(kdump_ip6_config) ] ; then
+	    _mode=dhcp6
 	else
-	    echo -n " ip=${_if}:dhcp"
+	    _mode=auto6
 	fi
     fi
+
+    case "$_mode" in
+	static)
+	    printf " %s" \
+		$(kdump_ip_config "$_if") \
+		$(kdump_ip6_config "$_if")
+	    ;;
+	dhcp|dhcp4)
+	    echo " ip=${_if}:dhcp"
+	    ;;
+	dhcp6)
+	    echo " ip=${_if}:dhcp6"
+	    ;;
+	auto6)
+	    echo " ip=${_if}:auto6"
+	    ;;
+	*)
+	    derror "Wrong KDUMP_NETCONFIG mode: $_mode"
+	    ;;
+    esac
 }
 
 cmdline() {
--- a/init/setup-kdump.functions
+++ b/init/setup-kdump.functions
@@ -230,7 +230,7 @@ kdump_prefix2netmask() {						   # {{{
 }									   # }}}
 
 #
-# Get the ip= parameter for a given device
+# Get the IPv4 ip= parameter for a given device
 #
 # Parameters:
 #   1) device  device name
@@ -267,6 +267,43 @@ function kdump_ip_config()						   # {{{
 }									   # }}}
 
 #
+# Get the IPv6 ip= parameter for a given device
+#
+# Parameters:
+#   1) device  device name
+# Output:
+#   ip configuration string that can be used for the ip= initrd parameter
+function kdump_ip6_config()						   # {{{
+{
+    local iface="$1"
+    local ipaddr peeraddr gwaddr hostname
+    local family cidr rest prefix
+
+    hostname=$(hostname)
+    gwaddr=$(ip -6 route show ::/0 | sed -n 's/.* via \([^ ]*\).*/[\1]/p')
+
+    while read family cidr rest
+    do
+	[ "$family" = "inet6" ] || continue
+
+	ipaddr="${cidr%/*}"
+	prefix="${cidr:${#ipaddr}}"
+	ipaddr="[$ipaddr]$prefix"
+	set -- $rest
+
+        if [ "$1" == "peer" ] ; then
+	    peeraddr="${2%/*}"
+	    prefix="${2:${#peeraddr}}"
+	    peeraddr="[$peeraddr]"
+	else
+	    peeraddr=
+        fi
+
+	echo "ip=$ipaddr:$peeraddr:$gwaddr::$hostname:$iface:none"
+    done < <(ip -6 address show dev "$iface" permanent scope global)
+}									   # }}}
+
+#
 # Get the save directory and protocol.
 #
 # Output variables:
--- a/sysconfig.kdump.in
+++ b/sysconfig.kdump.in
@@ -279,8 +279,8 @@ KDUMPTOOL_FLAGS=""
 ## ServiceRestart:	kdump
 #
 # Network configuration. Use "auto" for auto-detection in initrd, or a string
-# that contains the network device and the mode (dhcp,static), separated by
-# a colon. Example: "eth0:static" or "eth1:dhcp".
+# that contains the network device and the mode (static, dhcp, dhcp6, auto6),
+# separated by a colon. Example: "eth0:static" or "eth1:dhcp".
 #
 # For static configuration, you have to add the configuration to
 # KDUMP_COMMANDLINE_APPEND.