[Cluster-devel] [PATCH] cman-preconfig: allow cman to configure corosync multicast ttl

[Fabio M. Di Nitto <fdinitto@redhat.com>]

syntax:

<cman...>
 <multicast ttl=".."/>
</cman>

Resolves: rhbz#684020

Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>
---
 cman/daemon/cman-preconfig.c    |   24 +++++++++++++++++++++---
 config/tools/xml/cluster.rng.in |   17 +++++++++++++++--
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/cman/daemon/cman-preconfig.c b/cman/daemon/cman-preconfig.c
index 5239d89..0b3e7fd 100644
--- a/cman/daemon/cman-preconfig.c
+++ b/cman/daemon/cman-preconfig.c
@@ -276,7 +276,7 @@ static int add_udpu_members(struct objdb_iface_ver0 *objdb, hdb_handle_t interfa
 	return 0;
 }
 
-static int add_ifaddr(struct objdb_iface_ver0 *objdb, char *mcast, char *ifaddr, int port, enum tx_mech transport)
+static int add_ifaddr(struct objdb_iface_ver0 *objdb, char *mcast, char *ifaddr, int port, int ttl, enum tx_mech transport)
 {
 	hdb_handle_t totem_object_handle;
 	hdb_handle_t find_handle;
@@ -353,6 +353,19 @@ static int add_ifaddr(struct objdb_iface_ver0 *objdb, char *mcast, char *ifaddr,
 		objdb->object_key_create_typed(interface_object_handle, "mcastport",
 					       tmp, strlen(tmp)+1, OBJDB_VALUETYPE_STRING);
 
+		/* paranoia check. corosync already does it */
+		if ((ttl < 0) || (ttl > 255)) {
+			sprintf(error_reason, "TTL value (%u) out of range (0 - 255)", ttl);
+			return -1;
+		}
+
+		/* add the key to the objdb only if value is not default */
+		if (ttl != 1) {
+			sprintf(tmp, "%d", ttl);
+			objdb->object_key_create_typed(interface_object_handle, "ttl",
+						       tmp, strlen(tmp)+1, OBJDB_VALUETYPE_STRING);
+		}
+
 		num_interfaces++;
 	}
 	return ret;
@@ -592,6 +605,7 @@ static int get_nodename(struct objdb_iface_ver0 *objdb)
 	enum tx_mech transport = TX_MECH_UDP;
 	char *str;
 	int error;
+	unsigned int ttl = 1;
 
 	if (!getenv("CMAN_NOCONFIG")) {
 		/* our nodename */
@@ -661,6 +675,7 @@ static int get_nodename(struct objdb_iface_ver0 *objdb)
 			if (objdb->object_find_next(find_handle2, &mcast_handle) == 0) {
 
 				objdb_get_string(objdb, mcast_handle, "addr", &mcast_name);
+				objdb_get_int(objdb, mcast_handle, "ttl", &ttl, 0);
 			}
 			objdb->object_find_destroy(find_handle2);
 		}
@@ -730,7 +745,7 @@ static int get_nodename(struct objdb_iface_ver0 *objdb)
 		}
 	}
 
-	if (add_ifaddr(objdb, mcast_name, nodename, portnum, transport)) {
+	if (add_ifaddr(objdb, mcast_name, nodename, portnum, ttl, transport)) {
 		write_cman_pipe(error_reason);
 		return -1;
 	}
@@ -740,6 +755,7 @@ static int get_nodename(struct objdb_iface_ver0 *objdb)
 	objdb->object_find_create(node_object_handle,"altname", strlen("altname"), &find_handle);
 	while (objdb->object_find_next(find_handle, &alt_object) == 0) {
 		unsigned int port;
+		unsigned int altttl = 1;
 		char *node;
 		char *mcast;
 
@@ -749,11 +765,13 @@ static int get_nodename(struct objdb_iface_ver0 *objdb)
 
 		objdb_get_int(objdb, alt_object, "port", &port, portnum);
 
+		objdb_get_int(objdb, alt_object, "ttl", &altttl, ttl);
+
 		if (objdb_get_string(objdb, alt_object, "mcast", &mcast)) {
 			mcast = mcast_name;
 		}
 
-		if (add_ifaddr(objdb, mcast, node, portnum, transport)) {
+		if (add_ifaddr(objdb, mcast, node, portnum, altttl, transport)) {
 			write_cman_pipe(error_reason);
 			return -1;
 		}
diff --git a/config/tools/xml/cluster.rng.in b/config/tools/xml/cluster.rng.in
index 04906c9..c873cae 100644
--- a/config/tools/xml/cluster.rng.in
+++ b/config/tools/xml/cluster.rng.in
@@ -147,14 +147,22 @@ To validate your cluster.conf against this schema, run:
          instead of using the multicast address generated by cman. If
          a user does not specify a multicast address, cman creates one. It
          forms the upper 16 bits of the multicast address with 239.192 and
-         forms the lower 16 bits based on the cluster ID."> <attribute
-         name="addr" rha:description="A multicast address specified
+         forms the lower 16 bits based on the cluster ID.">
+      <optional>
+       <attribute name="addr" rha:description="A multicast address specified
          by a user. If you do specify a multicast address, you should
          use the 239.192.x.x series that cman uses. Otherwise, using a
          multicast address outside that range may cause unpredictable
          results. For example, using 224.0.0.x (All hosts on the network)
          may not be routed correctly, or even routed@all by some
          hardware." rha:sample="239.192.0.1"/>
+      </optional>
+      <optional>
+       <attribute name="ttl" rha:description="Define the TTL (time to live) of
+         a multicast packets. Useful only if nodes are on different subnets and
+         a multicast router is available in between." rha:default="1"
+         rha:sample="24"/>
+      </optional>
      </element>
     </optional>
    </element>
@@ -734,6 +742,11 @@ To validate your cluster.conf against this schema, run:
       <attribute name="mcast" rha:description="The multicast address
           to use on the second interface. cman(5)"/>
      </optional>
+
+     <optional>
+      <attribute name="ttl" rha:description="The multicast TTL 
+          to use on the second interface. cman(5)"/>
+     </optional>
     </element>
    </optional>
 
-- 
1.7.4