From e9bf87805cf968ef4542fefb123384dbf4b5f98c Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 14 Oct 2016 11:00:16 +0200
Subject: [PATCH] dhcp: make default dhcp plugin configurable at compile-time

---
 configure.ac                       | 12 +++++++++++-
 man/NetworkManager.conf.xml        |  6 +++---
 man/common.ent.in                  |  1 +
 src/dhcp-manager/nm-dhcp-manager.c | 12 +++++++++++-
 4 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index 30364a4c0d..d589227430 100644
--- a/configure.ac
+++ b/configure.ac
@@ -808,6 +808,16 @@ else
 	AC_DEFINE(WITH_DHCPCD, 0, [Define if you have dhcpcd])
 fi
 
+AC_ARG_WITH(config-dhcp-default, AS_HELP_STRING([--with-config-dhcp-default=dhclient|dhcpcd|internal], [Default configuration option for main.dhcp setting, used as fallback if the configuration option is unset]), [config_dhcp_default="$withval"], [config_dhcp_default=""])
+if test "$config_dhcp_default" = yes -o "$config_dhcp_default" = no; then
+	config_dhcp_default=''
+fi
+test -z "$config_dhcp_default" -a "$with_dhclient" != "no" && config_dhcp_default='dhclient'
+test -z "$config_dhcp_default" -a "$with_dhcpcd"   != "no" && config_dhcp_default='dhcpcd'
+test -z "$config_dhcp_default"                             && config_dhcp_default='internal'
+AC_DEFINE_UNQUOTED(NM_CONFIG_DEFAULT_DHCP, "$config_dhcp_default", [Default configuration option for main.dhcp setting])
+AC_SUBST(NM_CONFIG_DEFAULT_DHCP, $config_dhcp_default)
+
 # resolvconf and netconfig support
 AC_ARG_WITH(resolvconf, AS_HELP_STRING([--with-resolvconf=yes|no|path], [Enable resolvconf support]))
 AC_ARG_WITH(netconfig, AS_HELP_STRING([--with-netconfig=yes|no], [Enable SUSE netconfig support]))
@@ -1213,7 +1223,7 @@ echo "  netconfig: ${with_netconfig}"
 echo "  config-dns-rc-manager-default: ${config_dns_rc_manager_default}"
 echo
 
-echo "DHCP clients:"
+echo "DHCP clients (default $config_dhcp_default):"
 echo "  dhclient: $with_dhclient"
 echo "  dhcpcd: $with_dhcpcd"
 echo "  dhcpcd-supports-ipv6: $with_dhcpcd_supports_ipv6"
diff --git a/man/NetworkManager.conf.xml b/man/NetworkManager.conf.xml
index e662d43a82..c2bd02c4a4 100644
--- a/man/NetworkManager.conf.xml
+++ b/man/NetworkManager.conf.xml
@@ -189,9 +189,9 @@ plugins-=remove-me
         clients to be installed. The <literal>internal</literal>
         option uses a built-in DHCP client which is not currently as
         featureful as the external clients.</para>
-        <para>If this key is missing, available DHCP clients are
-        looked for in this order: <literal>dhclient</literal>,
-        <literal>dhcpcd</literal>,
+        <para>If this key is missing, it defaults to <literal>&NM_CONFIG_DEFAULT_DHCP;</literal>.
+        It the chosen plugin is not available, clients are looked for
+        in this order: <literal>dhclient</literal>, <literal>dhcpcd</literal>,
         <literal>internal</literal>.</para></listitem>
       </varlistentry>
       <varlistentry>
diff --git a/man/common.ent.in b/man/common.ent.in
index ec91e8a6a2..bb9adad248 100644
--- a/man/common.ent.in
+++ b/man/common.ent.in
@@ -5,3 +5,4 @@
 <!ENTITY NM_CONFIG_LOGGING_BACKEND_DEFAULT_TEXT "@NM_CONFIG_LOGGING_BACKEND_DEFAULT_TEXT@">
 <!ENTITY NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT "@NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT@">
 <!ENTITY NM_CONFIG_DEFAULT_DNS_RC_MANAGER "@NM_CONFIG_DEFAULT_DNS_RC_MANAGER@">
+<!ENTITY NM_CONFIG_DEFAULT_DHCP "@NM_CONFIG_DEFAULT_DHCP@">
diff --git a/src/dhcp-manager/nm-dhcp-manager.c b/src/dhcp-manager/nm-dhcp-manager.c
index cc0289c9ab..dee4039a5c 100644
--- a/src/dhcp-manager/nm-dhcp-manager.c
+++ b/src/dhcp-manager/nm-dhcp-manager.c
@@ -349,13 +349,23 @@ nm_dhcp_manager_init (NMDhcpManager *self)
 	if (nm_config_get_configure_and_quit (config)) {
 		client_factory = &_nm_dhcp_client_factory_internal;
 		if (client && !nm_streq (client, client_factory->name))
-			nm_log_warn (LOGD_DHCP, "dhcp-init: Using internal DHCP client since configure-and-quit is set.");
+			nm_log_info (LOGD_DHCP, "dhcp-init: Using internal DHCP client since configure-and-quit is set.");
 	} else {
 		if (client) {
 			client_factory = _client_factory_available (_client_factory_find_by_name (client));
 			if (!client_factory)
 				nm_log_warn (LOGD_DHCP, "dhcp-init: DHCP client '%s' not available", client);
 		}
+		if (!client_factory) {
+			client_factory = _client_factory_find_by_name (""NM_CONFIG_DEFAULT_DHCP);
+			if (!client_factory)
+				nm_log_err (LOGD_DHCP, "dhcp-init: default DHCP client '%s' is not installed", NM_CONFIG_DEFAULT_DHCP);
+			else {
+				client_factory = _client_factory_available (client_factory);
+				if (!client_factory)
+					nm_log_info (LOGD_DHCP, "dhcp-init: default DHCP client '%s' is not available", NM_CONFIG_DEFAULT_DHCP);
+			}
+		}
 		if (!client_factory) {
 			for (i = 0; i < G_N_ELEMENTS (_nm_dhcp_manager_factories); i++) {
 				client_factory = _client_factory_available (_nm_dhcp_manager_factories[i]);