dracut-module-setup: Support the network for ipv6 protocol

Previously, Kdump will save route to setup the network route in the 2nd
kernel for ipv4 protocol. To support ipv6 protocol, make Kdump fetch
correct nexthop, since the ruturning format is different.

In order to enhance kdump to support ipv6, support the static ip for
ipv6 protocol, which ipv4 has supported already.

Introduce a new lib function get_remote_host which is used to factor out
the ip address(ipv4 or ipv6) and hostname in /etc/kdump.conf.

Introduce a new lib function is_ipv6_address which is used to make sure
whether the passed ip address is ipv4 or ipv6.

Introduce a new lib function is_hostname which is used to confirm
whether the passed parameter is hostname, not the ip address.

Introduce a new function get_ip_route_field which is used to factor out
the specified string in ip route info.

Due to the different format between ipv4 and ipv6 protocol, quote the
ipv6 address with bracket "[]" to make dracut notify.

Signed-off-by: Minfei Huang <mhuang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>

dracut-module-setup.sh

@@ -89,19 +89,38 @@ kdump_setup_dns() {
 #$2: srcaddr
 #if it use static ip echo it, or echo null
 kdump_static_ip() {
-    local _netmask _gateway
-    local _netdev="$1" _srcaddr="$2"
-    local _ipaddr=$(ip addr show dev $_netdev permanent | \
-                    awk "/ $_srcaddr\/.* $_netdev\$/{print \$2}")
-    if [ -n "$_ipaddr" ]; then
-       _netmask=$(ipcalc -m $_ipaddr | cut -d'=' -f2)
-       _gateway=$(ip route list dev $_netdev | awk '/^default /{print $3}')
-       echo -n "${_srcaddr}::${_gateway}:${_netmask}::"
+    local _netdev="$1" _srcaddr="$2" _ipv6_flag
+    local _netmask _gateway _ipaddr _target _nexthop
+
+    _ipaddr=$(ip addr show dev $_netdev | awk "/ $_srcaddr\/.* /{print \$2}")
+
+    if is_ipv6_address $_srcaddr; then
+        _ipv6_flag="-6"
     fi
 
-    /sbin/ip route show | grep -v default | grep "^[[:digit:]].*via.* $_netdev " |\
-    while read line; do
-        echo $line | awk '{printf("rd.route=%s:%s:%s\n", $1, $3, $5)}'
+    if [ -n "$_ipaddr" ]; then
+        _gateway=$(ip $_ipv6_flag route list dev $_netdev | awk '/^default /{print $3}')
+
+        if [ "x" !=  "x"$_ipv6_flag ]; then
+            # _ipaddr="2002::56ff:feb6:56d5/64", _netmask is the number after "/"
+            _netmask=${_ipaddr#*\/}
+            _srcaddr="[$_srcaddr]"
+            _gateway="[$_gateway]"
+        else
+            _netmask=$(ipcalc -m $_ipaddr | cut -d'=' -f2)
+        fi
+        echo -n "${_srcaddr}::${_gateway}:${_netmask}::"
+    fi
+
+    /sbin/ip $_ipv6_flag route show | grep -v default | grep ".*via.* $_netdev " |\
+    while read _route; do
+        _target=`echo $_route | cut -d ' ' -f1`
+        _nexthop=`echo $_route | cut -d ' ' -f3`
+        if [ "x" !=  "x"$_ipv6_flag ]; then
+            _target="[$_target]"
+            _nexthop="[$_nexthop]"
+        fi
+        echo "rd.route=$_target:$_nexthop:$_netdev"
     done >> ${initdir}/etc/cmdline.d/45route-static.conf
 }
 
@@ -276,32 +295,30 @@ kdump_setup_netdev() {
     kdump_setup_dns "$_netdev"
 }
 
+get_ip_route_field()
+{
+    if `echo $1 | grep -q $2`; then
+        echo ${1##*$2} | cut -d ' ' -f1
+    fi
+}
+
 #Function:kdump_install_net
 #$1: config values of net line in kdump.conf
 #$2: srcaddr of network device
 kdump_install_net() {
-    local _server _netdev _srcaddr
+    local _server _netdev _srcaddr _route
     local config_val="$1"
 
-    _server=`echo $config_val | sed 's/.*@//' | cut -d':' -f1`
+    _server=$(get_remote_host $config_val)
 
-    _need_dns=`echo $_server|grep "[a-zA-Z]"`
-    [ -n "$_need_dns" ] && _server=`getent hosts $_server|cut -d' ' -f1`
+    is_hostname $_server && _server=`getent hosts $_server | head -n 1 | cut -d' ' -f1`
 
-    _netdev=`/sbin/ip route get to $_server 2>&1`
+    _route=`/sbin/ip -o route get to $_server 2>&1`
     [ $? != 0 ] && echo "Bad kdump location: $config_val" && exit 1
 
     #the field in the ip output changes if we go to another subnet
-    if [ -n "`echo $_netdev | grep via`" ]
-    then
-        # we are going to a different subnet
-        _srcaddr=`echo $_netdev|awk '{print $7}'|head -n 1`
-        _netdev=`echo $_netdev|awk '{print $5;}'|head -n 1`
-    else
-        # we are on the same subnet
-        _srcaddr=`echo $_netdev|awk '{print $5}'|head -n 1`
-        _netdev=`echo $_netdev|awk '{print $3}'|head -n 1`
-    fi
+    _srcaddr=$(get_ip_route_field "$_route" "src")
+    _netdev=$(get_ip_route_field "$_route" "dev")
 
     kdump_setup_netdev "${_netdev}" "${_srcaddr}"
 

kdump-lib.sh

@@ -201,3 +201,32 @@ is_atomic()
 {
     grep -q "ostree" /proc/cmdline
 }
+
+is_ipv6_address()
+{
+    echo $1 | grep -q ":"
+}
+
+# get ip address or hostname from nfs/ssh config value
+get_remote_host()
+{
+    local _config_val=$1
+
+    # ipv6 address in kdump.conf is around with "[]",
+    # factor out the ipv6 address
+    _config_val=${_config_val#*@}
+    _config_val=${_config_val%:/*}
+    _config_val=${_config_val#[}
+    _config_val=${_config_val%]}
+    echo $_config_val
+}
+
+is_hostname()
+{
+    local _hostname=`echo $1 | grep ":"`
+
+    if [ -n "$_hostname" ]; then
+        return 1
+    fi
+    echo $1 | grep -q "[a-zA-Z]"
+}