tipc: introduce UDP replicast

This patch introduces UDP replicast. A concept where we emulate
multicast by sending multiple unicast messages to configured peers.

The purpose of replicast is mainly to be able to use TIPC in cloud
environments where IP multicast is disabled. Using replicas to unicast
multicast messages is costly as we have to copy each skb and send the
copies individually.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 0 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 28056fa8f77a..d7b442dd6669 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -42,6 +42,7 @@
 #include "monitor.h"
 #include "bcast.h"
 #include "netlink.h"
+#include "udp_media.h"
 
 #define MAX_ADDR_STR 60
 
@@ -897,6 +898,49 @@ int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
+int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct tipc_bearer *b;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
+			       info->attrs[TIPC_NLA_BEARER],
+			       tipc_nl_bearer_policy);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	rtnl_lock();
+	b = tipc_bearer_find(net, name);
+	if (!b) {
+		rtnl_unlock();
+		return -EINVAL;
+	}
+
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
+		err = tipc_udp_nl_bearer_add(b,
+					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
+		if (err) {
+			rtnl_unlock();
+			return err;
+		}
+	}
+#endif
+	rtnl_unlock();
+
+	return 0;
+}
+
 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
 {
 	int err;