[network-manager-openvpn] handle 'subnet' topology better

[Dan Williams <dcbw src gnome org>]

commit 98dcecdf70e2637a8e64fed7f650babc56f9c1de
Author: Dan Williams <dcbw redhat com>
Date:   Tue Jul 14 06:52:31 2009 -0400

    handle 'subnet' topology better
    
    Since openvpn doesn't appear to actually pass topology to the
    script, we have to infer it from the 'ifconfig' arguments.  If the
    second argument to ifconfig appears to be a netmask, then use it
    as a netmask instead of the ptp address.

 src/nm-openvpn-service-openvpn-helper.c |   28 ++++++++++++++++++++++------
 1 files changed, 22 insertions(+), 6 deletions(-)
---
diff --git a/src/nm-openvpn-service-openvpn-helper.c b/src/nm-openvpn-service-openvpn-helper.c
index d9a596e..9823d94 100644
--- a/src/nm-openvpn-service-openvpn-helper.c
+++ b/src/nm-openvpn-service-openvpn-helper.c
@@ -331,8 +331,22 @@ main (int argc, char *argv[])
 
 	/* PTP address; for vpnc PTP address == internal IP4 address */
 	val = addr_to_gvalue (getenv ("ifconfig_remote"));
-	if (val)
-		g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PTP, val);
+	if (val) {
+		/* Sigh.  Openvpn added 'topology' stuff in 2.1 that changes the meaning
+		 * of the ifconfig bits without actually telling you what they are
+		 * supposed to mean; basically relying on specific 'ifconfig' behavior.
+		 */
+		tmp = getenv ("ifconfig_remote");
+		if (tmp && !strncmp (tmp, "255.", 4)) {
+			guint32 addr;
+
+			/* probably a netmask, not a PTP address; topology == subnet */
+			addr = g_value_get_uint (val);
+			g_value_set_uint (val, nm_utils_ip4_netmask_to_prefix (addr));
+			g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PREFIX, val);
+		} else
+			g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PTP, val);
+	}
 
 	/* Netmask
 	 *
@@ -348,10 +362,12 @@ main (int argc, char *argv[])
 		g_value_set_uint (val, nm_utils_ip4_netmask_to_prefix (temp_addr.s_addr));
 		g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PREFIX, val);
 	} else if (!tapdev) {
-		val = g_slice_new0 (GValue);
-		g_value_init (val, G_TYPE_UINT);
-		g_value_set_uint (val, 32);
-		g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PREFIX, val);
+		if (!g_hash_table_lookup (config, NM_VPN_PLUGIN_IP4_CONFIG_PREFIX)) {
+			val = g_slice_new0 (GValue);
+			g_value_init (val, G_TYPE_UINT);
+			g_value_set_uint (val, 32);
+			g_hash_table_insert (config, NM_VPN_PLUGIN_IP4_CONFIG_PREFIX, val);
+		}
 	} else
 		nm_warning ("No IP4 netmask/prefix (missing or invalid 'ifconfig_netmask')");