add random feeding code for ssh dump

ssh: add random feeding code

openssh usually depends on /dev/urandom to seeding PRNG (pseudo-random number
generator). To ensure there's sufficient entropy just feed /dev/urandom with
saved /var/lib/random-seed which is saved in installing phase.

dracut_install will print error message, so just exit and do not print error
again.

Todo: other dracut_install fail and exit, such as dd, makedumpfile.

[v2->v3]: use [[:blank:]] for whitespace checking.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

dracut-kdump.sh

@@ -102,6 +102,7 @@ dump_ssh()
     local _opt="-i $1 -o BatchMode=yes -o StrictHostKeyChecking=yes"
     local _dir="$KDUMP_PATH/$DATEDIR"
 
+    cat /var/lib/random-seed > /dev/urandom
     ssh -q $_opt $2 mkdir -p $_dir || return 1
 
     if [ "${CORE_COLLECTOR%% *}" = "scp" ]; then

dracut-module-setup.sh

@@ -17,6 +17,11 @@ depends() {
     return 0
 }
 
+is_ssh_dump_target()
+{
+    grep -q "^ssh[[:blank:]].*@" /etc/kdump.conf
+}
+
 kdump_to_udev_name() {
     local dev="$1"
 
@@ -339,6 +344,9 @@ kdump_check_iscsi_targets () {
 
 install() {
     kdump_install_conf
+    if is_ssh_dump_target; then
+        dracut_install /var/lib/random-seed || exit $?
+    fi
     inst "$moddir/monitor_dd_progress" "/kdumpscripts/monitor_dd_progress"
     chmod +x ${initdir}/kdumpscripts/monitor_dd_progress
     inst "/bin/dd" "/bin/dd"