DHCP_FQDN and DHCP_SEND_HOSTNAME introduced

  The way DHCP_HOSTNAME is being sent to DHCP server has been completely
  reworked...

  DHCP_FQDN now allows user to specify fully qualified domain name to be
  sent to DHCP server instead of just using simple hostname. This option
  takes precedence before DHCP_HOSTNAME variable.

  DHCP_SEND_HOSTNAME can be used to tell initscripts to not send either
  DHCP_HOSTNAME or DHCP_FQDN to DHCP server.

  Both of these options should behave same as they do in NetworkManager.

2 files changed, 38 insertions, 14 deletions

diff --git a/sysconfig/network-scripts/ifup-eth b/sysconfig/network-scripts/ifup-eth
index b6a883f6..3da5c16b 100755
--- a/sysconfig/network-scripts/ifup-eth
+++ b/sysconfig/network-scripts/ifup-eth
@@ -186,13 +186,9 @@ if [ -n "${DYNCONFIG}" ] && [ -x /sbin/dhclient ]; then
     generate_config_file_name
     generate_lease_file_name
 
-    if is_hostname_set; then
-        # We already have the hostname ->> send it to DHCP:
-        DHCLIENTARGS="${DHCLIENTARGS} -H ${DHCP_HOSTNAME:-${HOSTNAME%%.*}} ${ONESHOT} -q ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient-${DEVICE}.pid"
-    else
-        # We need to acquire the hostname:
-        DHCLIENTARGS="${DHCLIENTARGS} ${DHCP_HOSTNAME:+-H $DHCP_HOSTNAME} ${ONESHOT} -q ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient-${DEVICE}.pid"
-    fi
+    # Initialize the dhclient args and obtain the hostname options if needed:
+    DHCLIENTARGS="${DHCLIENTARGS} ${ONESHOT} -q ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient-${DEVICE}.pid"
+    set_hostname_options DHCLIENTARGS
 
     echo
     echo -n $"Determining IP information for ${DEVICE}..."
@@ -335,13 +331,9 @@ if is_true "${DHCPV6C}" && [ -x /sbin/dhclient ]; then
     echo
     echo -n $"Determining IPv6 information for ${DEVICE}..."
 
-    if is_hostname_set; then
-        # We already have the hostname ->> send it to DHCP:
-        DHCLIENTARGS="-6 -1 ${DHCPV6C_OPTIONS} ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient6-${DEVICE}.pid -H ${DHCP_HOSTNAME:-${HOSTNAME%%.*}} ${DEVICE}"
-    else
-        # We need to acquire the hostname:
-        DHCLIENTARGS="-6 -1 ${DHCPV6C_OPTIONS} ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient6-${DEVICE}.pid ${DHCP_HOSTNAME:+-H $DHCP_HOSTNAME} ${DEVICE}"
-    fi
+    # Initialize the dhclient args for IPv6 and obtain the hostname options if needed:
+    DHCLIENTARGS="-6 -1 ${DHCPV6C_OPTIONS} ${DHCLIENTCONF} -lf ${LEASEFILE} -pf /var/run/dhclient6-${DEVICE}.pid ${DEVICE}"
+    set_hostname_options DHCLIENTARGS
 
     if /sbin/dhclient $DHCLIENTARGS; then
         echo $" done."
diff --git a/sysconfig/network-scripts/network-functions b/sysconfig/network-scripts/network-functions
index 850cc3ff..1867c38a 100644
--- a/sysconfig/network-scripts/network-functions
+++ b/sysconfig/network-scripts/network-functions
@@ -397,6 +397,38 @@ need_hostname ()
     fi
 }
 
+set_hostname_options ()
+{
+    # User explicitly requires to *not* send DHCP_HOSTNAME, DHCP_FQDN or HOSTNAME:
+    is_false "${DHCP_SEND_HOSTNAME}" && return
+
+    if [[ -n "${DHCP_HOSTNAME}" && -n "${DHCP_FQDN}" ]]; then
+        net_log $"Both 'DHCP_HOSTNAME=${DHCP_HOSTNAME}' and 'DHCP_FQDN=${DHCP_FQDN}' are configured... Using DHCP_FQDN." warning
+    fi
+
+    local hostname_options=''
+
+    # DHCP_FQDN takes precedence before DHCP_HOSTNAME -- as it does in NetworkManager,
+    # and DHCP_HOSTNAME takes precedence before HOSTNAME:
+    if [[ -n "${DHCP_FQDN}" ]]; then
+        hostname_options="-F ${DHCP_FQDN}"
+    elif [[ -n "${DHCP_HOSTNAME}" ]]; then
+        hostname_options="-H ${DHCP_HOSTNAME}"
+    elif is_hostname_set; then
+        # We need to truncate the hostname in case it is the FQDN:
+        hostname_options="-H ${HOSTNAME%%.*}"
+    else
+        # Nothing to send to the DHCP server:
+        # ['(none)', 'localhost' or 'localhost.localdomain' are not valid]
+        return
+    fi
+
+    # Append the hostname options to the content of passed variable name:
+    eval "$1='${!1} ${hostname_options}'"
+
+    return
+}
+
 set_hostname ()
 {
     hostname $1