[PATCH net-next 0/7] tipc: introduce UDP replicast

[PATCH net-next 0/7] tipc: introduce UDP replicast

[Richard Alpe]

This series introduces UDP replicast. A concept where we emulate multicast by
sending multiple unicast messages to configured peers. This allows TIPC to be
used in environments where IP multicast is disabled.

There is a corresponding patch series for the tipc user space tool that
allows a user to add remote addresses to the replicast list.

Richard Alpe (7):
  tipc: split UDP nl address parsing
  tipc: split UDP send function
  tipc: refactor multicast ip check
  tipc: introduce UDP replicast
  tipc: add replicast peer discovery
  tipc: add the ability to get UDP options via netlink
  tipc: add UDP remoteip dump to netlink API

 include/uapi/linux/tipc_netlink.h |   3 +
 net/tipc/bearer.c                 |  52 ++++
 net/tipc/bearer.h                 |   1 +
 net/tipc/netlink.c                |  15 +-
 net/tipc/udp_media.c              | 520 +++++++++++++++++++++++++++++++-------
 net/tipc/udp_media.h              |  46 ++++
 6 files changed, 545 insertions(+), 92 deletions(-)
 create mode 100644 net/tipc/udp_media.h

-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 1/7] tipc: split UDP nl address parsing

[Richard Alpe]

Split the UDP netlink parse function so that it only parses one
netlink attribute at the time. This makes the parse function more
generic and allow future UDP API functions to use it for parsing.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
---
 net/tipc/udp_media.c | 112 +++++++++++++++++++++++++--------------------------
 1 file changed, 55 insertions(+), 57 deletions(-)

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 33bdf54..adb3c21 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -258,68 +258,47 @@ static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 }
 
 /**
- * parse_options - build local/remote addresses from configuration
- * @attrs:	netlink config data
- * @ub:		UDP bearer instance
- * @local:	local bearer IP address/port
- * @remote:	peer or multicast IP/port
+ * tipc_parse_udp_addr - build udp media address from netlink data
+ * @nlattr:	netlink attribute containing sockaddr storage aligned address
+ * @addr:	tipc media address to fill with address, port and protocol type
+ * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
  */
-static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
-			 struct udp_media_addr *local,
-			 struct udp_media_addr *remote)
+
+static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
+			       u32 *scope_id)
 {
-	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
-	struct sockaddr_storage sa_local, sa_remote;
+	struct sockaddr_storage sa;
 
-	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
-		goto err;
-	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
-			     attrs[TIPC_NLA_BEARER_UDP_OPTS],
-			     tipc_nl_udp_policy))
-		goto err;
-	if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
-		nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL],
-			   sizeof(sa_local));
-		nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE],
-			   sizeof(sa_remote));
-	} else {
-err:
-		pr_err("Invalid UDP bearer configuration");
-		return -EINVAL;
-	}
-	if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET) {
-		struct sockaddr_in *ip4;
-
-		ip4 = (struct sockaddr_in *)&sa_local;
-		local->proto = htons(ETH_P_IP);
-		local->port = ip4->sin_port;
-		local->ipv4.s_addr = ip4->sin_addr.s_addr;
-
-		ip4 = (struct sockaddr_in *)&sa_remote;
-		remote->proto = htons(ETH_P_IP);
-		remote->port = ip4->sin_port;
-		remote->ipv4.s_addr = ip4->sin_addr.s_addr;
+	nla_memcpy(&sa, nla, sizeof(sa));
+	if (sa.ss_family == AF_INET) {
+		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
+
+		addr->proto = htons(ETH_P_IP);
+		addr->port = ip4->sin_port;
+		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
 		return 0;
 
 #if IS_ENABLED(CONFIG_IPV6)
-	} else if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET6) {
-		int atype;
-		struct sockaddr_in6 *ip6;
-
-		ip6 = (struct sockaddr_in6 *)&sa_local;
-		atype = ipv6_addr_type(&ip6->sin6_addr);
-		if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id)
-			return -EINVAL;
-
-		local->proto = htons(ETH_P_IPV6);
-		local->port = ip6->sin6_port;
-		memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
-		ub->ifindex = ip6->sin6_scope_id;
-
-		ip6 = (struct sockaddr_in6 *)&sa_remote;
-		remote->proto = htons(ETH_P_IPV6);
-		remote->port = ip6->sin6_port;
-		memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
+	} else if (sa.ss_family == AF_INET6) {
+		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
+
+		addr->proto = htons(ETH_P_IPV6);
+		addr->port = ip6->sin6_port;
+		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
+
+		/* Scope ID is only interesting for local addresses */
+		if (scope_id) {
+			int atype;
+
+			atype = ipv6_addr_type(&ip6->sin6_addr);
+			if (__ipv6_addr_needs_scope_id(atype) &&
+			    !ip6->sin6_scope_id) {
+				return -EINVAL;
+			}
+
+			*scope_id = ip6->sin6_scope_id ? : 0;
+		}
+
 		return 0;
 #endif
 	}
@@ -344,14 +323,33 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	struct udp_media_addr local = {0};
 	struct udp_port_cfg udp_conf = {0};
 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
+	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 
 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 	if (!ub)
 		return -ENOMEM;
 
+	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
+		goto err;
+
+	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
+			     attrs[TIPC_NLA_BEARER_UDP_OPTS],
+			     tipc_nl_udp_policy))
+		goto err;
+
+	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
+		pr_err("Invalid UDP bearer configuration");
+		return -EINVAL;
+	}
+
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
+				  &ub->ifindex);
+	if (err)
+		goto err;
+
 	remote = (struct udp_media_addr *)&b->bcast_addr.value;
 	memset(remote, 0, sizeof(struct udp_media_addr));
-	err = parse_options(attrs, ub, &local, remote);
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], remote, NULL);
 	if (err)
 		goto err;
 
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 2/7] tipc: split UDP send function

[Richard Alpe]

Split the UDP send function into two. One callback that prepares the
skb and one transmit function that sends the skb. This will come in
handy in later patches, when we introduce UDP replicast.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
---
 net/tipc/udp_media.c | 50 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index adb3c21..7033b4a 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -140,28 +140,13 @@ static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 }
 
 /* tipc_send_msg - enqueue a send request */
-static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
-			     struct tipc_bearer *b,
-			     struct tipc_media_addr *dest)
+static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
+			 struct udp_bearer *ub, struct udp_media_addr *src,
+			 struct udp_media_addr *dst)
 {
 	int ttl, err = 0;
-	struct udp_bearer *ub;
-	struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
-	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 	struct rtable *rt;
 
-	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
-		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
-		if (err)
-			goto tx_error;
-	}
-
-	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
-	ub = rcu_dereference_rtnl(b->media_ptr);
-	if (!ub) {
-		err = -ENODEV;
-		goto tx_error;
-	}
 	if (dst->proto == htons(ETH_P_IP)) {
 		struct flowi4 fl = {
 			.daddr = dst->ipv4.s_addr,
@@ -207,6 +192,35 @@ tx_error:
 	return err;
 }
 
+static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
+			     struct tipc_bearer *b,
+			     struct tipc_media_addr *addr)
+{
+	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
+	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
+	struct udp_bearer *ub;
+	int err = 0;
+
+	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
+		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
+		if (err)
+			goto tx_error;
+	}
+
+	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
+	ub = rcu_dereference_rtnl(b->media_ptr);
+	if (!ub) {
+		err = -ENODEV;
+		goto tx_error;
+	}
+
+	return tipc_udp_xmit(net, skb, ub, src, dst);
+
+tx_error:
+	kfree_skb(skb);
+	return err;
+}
+
 /* tipc_udp_recv - read data from bearer socket */
 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 {
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 3/7] tipc: refactor multicast ip check

[Richard Alpe]

Add a function to check if a tipc UDP media address is a multicast
address or not. This is a purely cosmetic change.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/udp_media.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 7033b4a..b8ec1a1 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -84,6 +84,17 @@ struct udp_bearer {
 	struct work_struct work;
 };
 
+static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
+{
+	if (ntohs(addr->proto) == ETH_P_IP)
+		return ipv4_is_multicast(addr->ipv4.s_addr);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		return ipv6_addr_is_multicast(&addr->ipv6);
+#endif
+	return 0;
+}
+
 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
 				    struct udp_media_addr *ua)
@@ -91,15 +102,9 @@ static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
 	memset(addr, 0, sizeof(struct tipc_media_addr));
 	addr->media_id = TIPC_MEDIA_TYPE_UDP;
 	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
-	if (ntohs(ua->proto) == ETH_P_IP) {
-		if (ipv4_is_multicast(ua->ipv4.s_addr))
-			addr->broadcast = 1;
-	} else if (ntohs(ua->proto) == ETH_P_IPV6) {
-		if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
-			addr->broadcast = 1;
-	} else {
-		pr_err("Invalid UDP media address\n");
-	}
+
+	if (tipc_udp_is_mcast_addr(ua))
+		addr->broadcast = 1;
 }
 
 /* tipc_udp_addr2str - convert ip/udp address to string */
@@ -255,15 +260,11 @@ static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 	struct sock *sk = ub->ubsock->sk;
 
 	if (ntohs(remote->proto) == ETH_P_IP) {
-		if (!ipv4_is_multicast(remote->ipv4.s_addr))
-			return 0;
 		mreqn.imr_multiaddr = remote->ipv4;
 		mreqn.imr_ifindex = ub->ifindex;
 		err = ip_mc_join_group(sk, &mreqn);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
-		if (!ipv6_addr_is_multicast(&remote->ipv6))
-			return 0;
 		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 						   &remote->ipv6);
 #endif
@@ -408,8 +409,11 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	tuncfg.encap_destroy = NULL;
 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 
-	if (enable_mcast(ub, remote))
-		goto err;
+	if (tipc_udp_is_mcast_addr(remote)) {
+		if (enable_mcast(ub, remote))
+			goto err;
+	}
+
 	return 0;
 err:
 	kfree(ub);
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 4/7] tipc: introduce UDP replicast

[Richard Alpe]

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>
---
 include/uapi/linux/tipc_netlink.h |   1 +
 net/tipc/bearer.c                 |  44 ++++++++++++++
 net/tipc/bearer.h                 |   1 +
 net/tipc/netlink.c                |   5 ++
 net/tipc/udp_media.c              | 118 ++++++++++++++++++++++++++++++++++----
 net/tipc/udp_media.h              |  44 ++++++++++++++
 6 files changed, 201 insertions(+), 12 deletions(-)
 create mode 100644 net/tipc/udp_media.h

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index bcb65ef..b15664c 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -60,6 +60,7 @@ enum {
 	TIPC_NL_MON_GET,
 	TIPC_NL_MON_PEER_GET,
 	TIPC_NL_PEER_REMOVE,
+	TIPC_NL_BEARER_ADD,
 
 	__TIPC_NL_CMD_MAX,
 	TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 28056fa..d7b442d 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;
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 83a9abb..78892e2f 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -181,6 +181,7 @@ int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info);
+int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info);
 
 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info);
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 2718de6..3122f21 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -161,6 +161,11 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 		.policy = tipc_nl_policy,
 	},
 	{
+		.cmd	= TIPC_NL_BEARER_ADD,
+		.doit	= tipc_nl_bearer_add,
+		.policy = tipc_nl_policy,
+	},
+	{
 		.cmd	= TIPC_NL_BEARER_SET,
 		.doit	= tipc_nl_bearer_set,
 		.policy = tipc_nl_policy,
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index b8ec1a1..6b938cc 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -49,6 +49,7 @@
 #include "core.h"
 #include "bearer.h"
 #include "netlink.h"
+#include "msg.h"
 
 /* IANA assigned UDP port */
 #define UDP_PORT_DEFAULT	6118
@@ -70,6 +71,13 @@ struct udp_media_addr {
 	};
 };
 
+/* struct udp_replicast - container for UDP remote addresses */
+struct udp_replicast {
+	struct udp_media_addr addr;
+	struct rcu_head rcu;
+	struct list_head list;
+};
+
 /**
  * struct udp_bearer - ip/udp bearer data structure
  * @bearer:	associated generic tipc bearer
@@ -82,6 +90,7 @@ struct udp_bearer {
 	struct socket *ubsock;
 	u32 ifindex;
 	struct work_struct work;
+	struct udp_replicast rcast;
 };
 
 static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
@@ -203,29 +212,75 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 {
 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
+	struct udp_replicast *rcast;
 	struct udp_bearer *ub;
 	int err = 0;
 
 	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
 		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
 		if (err)
-			goto tx_error;
+			goto out;
 	}
 
 	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
 	ub = rcu_dereference_rtnl(b->media_ptr);
 	if (!ub) {
 		err = -ENODEV;
-		goto tx_error;
+		goto out;
 	}
 
-	return tipc_udp_xmit(net, skb, ub, src, dst);
+	if (!addr->broadcast || list_empty(&ub->rcast.list))
+		return tipc_udp_xmit(net, skb, ub, src, dst);
 
-tx_error:
+	/* Replicast, send an skb to each configured IP address */
+	list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
+		struct sk_buff *_skb;
+
+		_skb = pskb_copy(skb, GFP_ATOMIC);
+		if (!_skb) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr);
+		if (err) {
+			kfree_skb(_skb);
+			goto out;
+		}
+	}
+	err = 0;
+out:
 	kfree_skb(skb);
 	return err;
 }
 
+static int tipc_udp_rcast_add(struct tipc_bearer *b,
+			      struct udp_media_addr *addr)
+{
+	struct udp_replicast *rcast;
+	struct udp_bearer *ub;
+
+	ub = rcu_dereference_rtnl(b->media_ptr);
+	if (!ub)
+		return -ENODEV;
+
+	rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
+	if (!rcast)
+		return -ENOMEM;
+
+	memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
+
+	if (ntohs(addr->proto) == ETH_P_IP)
+		pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (ntohs(addr->proto) == ETH_P_IPV6)
+		pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
+#endif
+
+	list_add_rcu(&rcast->list, &ub->rcast.list);
+	return 0;
+}
+
 /* tipc_udp_recv - read data from bearer socket */
 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 {
@@ -320,6 +375,32 @@ static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
 	return -EADDRNOTAVAIL;
 }
 
+int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
+{
+	int err;
+	struct udp_media_addr addr = {0};
+	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
+	struct udp_media_addr *dst;
+
+	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy))
+		return -EINVAL;
+
+	if (!opts[TIPC_NLA_UDP_REMOTE])
+		return -EINVAL;
+
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
+	if (err)
+		return err;
+
+	dst = (struct udp_media_addr *)&b->bcast_addr.value;
+	if (tipc_udp_is_mcast_addr(dst)) {
+		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
+		return -EINVAL;
+	}
+
+	return tipc_udp_rcast_add(b, &addr);
+}
+
 /**
  * tipc_udp_enable - callback to create a new udp bearer instance
  * @net:	network namespace
@@ -334,7 +415,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 {
 	int err = -EINVAL;
 	struct udp_bearer *ub;
-	struct udp_media_addr *remote;
+	struct udp_media_addr remote = {0};
 	struct udp_media_addr local = {0};
 	struct udp_port_cfg udp_conf = {0};
 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
@@ -344,6 +425,8 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	if (!ub)
 		return -ENOMEM;
 
+	INIT_LIST_HEAD(&ub->rcast.list);
+
 	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 		goto err;
 
@@ -362,9 +445,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	if (err)
 		goto err;
 
-	remote = (struct udp_media_addr *)&b->bcast_addr.value;
-	memset(remote, 0, sizeof(struct udp_media_addr));
-	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], remote, NULL);
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
 	if (err)
 		goto err;
 
@@ -409,10 +490,17 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	tuncfg.encap_destroy = NULL;
 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 
-	if (tipc_udp_is_mcast_addr(remote)) {
-		if (enable_mcast(ub, remote))
-			goto err;
-	}
+	/**
+	 * The bcast media address port is used for all peers and the ip
+	 * is used if it's a multicast address.
+	 */
+	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
+	if (tipc_udp_is_mcast_addr(&remote))
+		err = enable_mcast(ub, &remote);
+	else
+		err = tipc_udp_rcast_add(b, &remote);
+	if (err)
+		goto err;
 
 	return 0;
 err:
@@ -424,6 +512,12 @@ err:
 static void cleanup_bearer(struct work_struct *work)
 {
 	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
+	struct udp_replicast *rcast, *tmp;
+
+	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
+		list_del_rcu(&rcast->list);
+		kfree_rcu(rcast, rcu);
+	}
 
 	if (ub->ubsock)
 		udp_tunnel_sock_release(ub->ubsock);
diff --git a/net/tipc/udp_media.h b/net/tipc/udp_media.h
new file mode 100644
index 0000000..4dcb548
--- /dev/null
+++ b/net/tipc/udp_media.h
@@ -0,0 +1,44 @@
+/*
+ * net/tipc/udp_media.h: Include file for UDP bearer media
+ *
+ * Copyright (c) 1996-2006, 2013-2016, Ericsson AB
+ * Copyright (c) 2005, 2010-2011, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef CONFIG_TIPC_MEDIA_UDP
+#ifndef _TIPC_UDP_MEDIA_H
+#define _TIPC_UDP_MEDIA_H
+
+int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr);
+
+#endif
+#endif
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 5/7] tipc: add replicast peer discovery

[Richard Alpe]

Automatically learn UDP remote IP addresses of communicating peers by
looking at the source IP address of incoming TIPC link configuration
messages (neighbor discovery).

This makes configuration slightly easier and removes the problematic
scenario where a node receives directly addressed neighbor discovery
messages sent using replicast which the node cannot "reply" to using
mutlicast, leaving the link FSM in a limbo state.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/udp_media.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 80 insertions(+), 3 deletions(-)

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 6b938cc..6ece3c9 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -254,6 +254,26 @@ out:
 	return err;
 }
 
+static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
+				   struct udp_media_addr *addr)
+{
+	struct udp_replicast *rcast, *tmp;
+	struct udp_bearer *ub;
+
+	ub = rcu_dereference_rtnl(b->media_ptr);
+	if (!ub) {
+		pr_err_ratelimited("UDP bearer instance not found\n");
+		return false;
+	}
+
+	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
+		if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
+			return true;
+	}
+
+	return false;
+}
+
 static int tipc_udp_rcast_add(struct tipc_bearer *b,
 			      struct udp_media_addr *addr)
 {
@@ -281,29 +301,83 @@ static int tipc_udp_rcast_add(struct tipc_bearer *b,
 	return 0;
 }
 
+static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
+{
+	struct udp_media_addr src = {0};
+	struct udp_media_addr *dst;
+
+	dst = (struct udp_media_addr *)&b->bcast_addr.value;
+	if (tipc_udp_is_mcast_addr(dst))
+		return 0;
+
+	src.port = udp_hdr(skb)->source;
+
+	if (ip_hdr(skb)->version == 4) {
+		struct iphdr *iphdr = ip_hdr(skb);
+
+		src.proto = htons(ETH_P_IP);
+		src.ipv4.s_addr = iphdr->saddr;
+		if (ipv4_is_multicast(iphdr->daddr))
+			return 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (ip_hdr(skb)->version == 6) {
+		struct ipv6hdr *iphdr = ipv6_hdr(skb);
+
+		src.proto = htons(ETH_P_IPV6);
+		src.ipv6 = iphdr->saddr;
+		if (ipv6_addr_is_multicast(&iphdr->daddr))
+			return 0;
+#endif
+	} else {
+		return 0;
+	}
+
+	if (likely(tipc_udp_is_known_peer(b, &src)))
+		return 0;
+
+	return tipc_udp_rcast_add(b, &src);
+}
+
 /* tipc_udp_recv - read data from bearer socket */
 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct udp_bearer *ub;
 	struct tipc_bearer *b;
+	struct tipc_msg *hdr;
+	int err;
 
 	ub = rcu_dereference_sk_user_data(sk);
 	if (!ub) {
 		pr_err_ratelimited("Failed to get UDP bearer reference");
-		kfree_skb(skb);
-		return 0;
+		goto out;
 	}
-
 	skb_pull(skb, sizeof(struct udphdr));
+	hdr = buf_msg(skb);
+
 	rcu_read_lock();
 	b = rcu_dereference_rtnl(ub->bearer);
+	if (!b)
+		goto rcu_out;
 
 	if (b && test_bit(0, &b->up)) {
 		tipc_rcv(sock_net(sk), skb, b);
 		rcu_read_unlock();
 		return 0;
 	}
+
+	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
+		err = tipc_udp_rcast_disc(b, skb);
+		if (err)
+			goto rcu_out;
+	}
+
+	tipc_rcv(sock_net(sk), skb, b);
 	rcu_read_unlock();
+	return 0;
+
+rcu_out:
+	rcu_read_unlock();
+out:
 	kfree_skb(skb);
 	return 0;
 }
@@ -398,6 +472,9 @@ int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
 		return -EINVAL;
 	}
 
+	if (tipc_udp_is_known_peer(b, &addr))
+		return 0;
+
 	return tipc_udp_rcast_add(b, &addr);
 }
 
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 6/7] tipc: add the ability to get UDP options via netlink

[Richard Alpe]

Add UDP bearer options to netlink bearer get message. This is used by
the tipc user space tool to display UDP options.

The UDP bearer information is passed using either a sockaddr_in or
sockaddr_in6 structs. This means the user space receiver should
intermediately store the retrieved data in a large enough struct
(sockaddr_strage) before casting to the proper IP version type.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
---
 include/uapi/linux/tipc_netlink.h |  2 ++
 net/tipc/bearer.c                 |  8 +++++
 net/tipc/udp_media.c              | 61 +++++++++++++++++++++++++++++++++++++++
 net/tipc/udp_media.h              |  1 +
 4 files changed, 72 insertions(+)

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index b15664c..f9edd20 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -61,6 +61,7 @@ enum {
 	TIPC_NL_MON_PEER_GET,
 	TIPC_NL_PEER_REMOVE,
 	TIPC_NL_BEARER_ADD,
+	TIPC_NL_UDP_GET_REMOTEIP,
 
 	__TIPC_NL_CMD_MAX,
 	TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
@@ -100,6 +101,7 @@ enum {
 	TIPC_NLA_UDP_UNSPEC,
 	TIPC_NLA_UDP_LOCAL,		/* sockaddr_storage */
 	TIPC_NLA_UDP_REMOTE,		/* sockaddr_storage */
+	TIPC_NLA_UDP_MULTI_REMOTEIP,	/* flag */
 
 	__TIPC_NLA_UDP_MAX,
 	TIPC_NLA_UDP_MAX = __TIPC_NLA_UDP_MAX - 1
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index d7b442d..975dbeb 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -712,6 +712,14 @@ static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
 		goto prop_msg_full;
 
 	nla_nest_end(msg->skb, prop);
+
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
+		if (tipc_udp_nl_add_bearer_data(msg, bearer))
+			goto attr_msg_full;
+	}
+#endif
+
 	nla_nest_end(msg->skb, attrs);
 	genlmsg_end(msg->skb, hdr);
 
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 6ece3c9..a6cdd98 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -401,6 +401,67 @@ static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 	return err;
 }
 
+static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
+				  struct udp_media_addr *addr, int nla_t)
+{
+	if (ntohs(addr->proto) == ETH_P_IP) {
+		struct sockaddr_in ip4;
+
+		ip4.sin_family = AF_INET;
+		ip4.sin_port = addr->port;
+		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
+		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
+			return -EMSGSIZE;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
+		struct sockaddr_in6 ip6;
+
+		ip6.sin6_family = AF_INET6;
+		ip6.sin6_port  = addr->port;
+		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
+		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
+			return -EMSGSIZE;
+#endif
+	}
+
+	return 0;
+}
+
+int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
+{
+	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
+	struct udp_media_addr *dst;
+	struct udp_bearer *ub;
+	struct nlattr *nest;
+
+	ub = rcu_dereference_rtnl(b->media_ptr);
+	if (!ub)
+		return -ENODEV;
+
+	nest = nla_nest_start(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
+	if (!nest)
+		goto msg_full;
+
+	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
+		goto msg_full;
+
+	dst = (struct udp_media_addr *)&b->bcast_addr.value;
+	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
+		goto msg_full;
+
+	if (!list_empty(&ub->rcast.list)) {
+		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
+			goto msg_full;
+	}
+
+	nla_nest_end(msg->skb, nest);
+	return 0;
+msg_full:
+	nla_nest_cancel(msg->skb, nest);
+	return -EMSGSIZE;
+}
+
 /**
  * tipc_parse_udp_addr - build udp media address from netlink data
  * @nlattr:	netlink attribute containing sockaddr storage aligned address
diff --git a/net/tipc/udp_media.h b/net/tipc/udp_media.h
index 4dcb548..c06326a 100644
--- a/net/tipc/udp_media.h
+++ b/net/tipc/udp_media.h
@@ -39,6 +39,7 @@
 #define _TIPC_UDP_MEDIA_H
 
 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr);
+int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b);
 
 #endif
 #endif
-- 
2.1.4


------------------------------------------------------------------------------

[PATCH net-next 7/7] tipc: add UDP remoteip dump to netlink API

[Richard Alpe]

When using replicast a UDP bearer can have an arbitrary amount of
remote ip addresses associated with it. This means we cannot simply
add all remote ip addresses to an existing bearer data message as it
might fill the message, leaving us with a truncated message that we
can't safely resume. To handle this we introduce the new netlink
command TIPC_NL_UDP_GET_REMOTEIP. This command is intended to be
called when the bearer data message has the
TIPC_NLA_UDP_MULTI_REMOTEIP flag set, indicating there are more than
one remote ip (replicast).

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/netlink.c   | 10 +++++-
 net/tipc/udp_media.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 net/tipc/udp_media.h |  1 +
 3 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 3122f21..3200059 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -41,6 +41,7 @@
 #include "link.h"
 #include "node.h"
 #include "net.h"
+#include "udp_media.h"
 #include <net/genetlink.h>
 
 static const struct nla_policy tipc_nl_policy[TIPC_NLA_MAX + 1] = {
@@ -247,7 +248,14 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 		.cmd	= TIPC_NL_PEER_REMOVE,
 		.doit	= tipc_nl_peer_rm,
 		.policy = tipc_nl_policy,
-	}
+	},
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	{
+		.cmd	= TIPC_NL_UDP_GET_REMOTEIP,
+		.dumpit	= tipc_udp_nl_dump_remoteip,
+		.policy = tipc_nl_policy,
+	},
+#endif
 };
 
 int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***attr)
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index a6cdd98..245e9a2 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -428,6 +428,96 @@ static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
 	return 0;
 }
 
+int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	u32 bid = cb->args[0];
+	u32 skip_cnt = cb->args[1];
+	u32 portid = NETLINK_CB(cb->skb).portid;
+	struct udp_replicast *rcast, *tmp;
+	struct tipc_bearer *b;
+	struct udp_bearer *ub;
+	void *hdr;
+	int err;
+	int i;
+
+	if (!bid && !skip_cnt) {
+		struct net *net = sock_net(skb->sk);
+		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
+		struct nlattr **attrs;
+		char *bname;
+
+		err = tipc_nlmsg_parse(cb->nlh, &attrs);
+		if (err)
+			return err;
+
+		if (!attrs[TIPC_NLA_BEARER])
+			return -EINVAL;
+
+		err = nla_parse_nested(battrs, TIPC_NLA_BEARER_MAX,
+				       attrs[TIPC_NLA_BEARER],
+				       tipc_nl_bearer_policy);
+		if (err)
+			return err;
+
+		if (!battrs[TIPC_NLA_BEARER_NAME])
+			return -EINVAL;
+
+		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
+
+		rtnl_lock();
+		b = tipc_bearer_find(net, bname);
+		if (!b) {
+			rtnl_unlock();
+			return -EINVAL;
+		}
+		bid = b->identity;
+	} else {
+		struct net *net = sock_net(skb->sk);
+		struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+		rtnl_lock();
+		b = rtnl_dereference(tn->bearer_list[bid]);
+		if (!b) {
+			rtnl_unlock();
+			return -EINVAL;
+		}
+	}
+
+	ub = rcu_dereference_rtnl(b->media_ptr);
+	if (!ub) {
+		rtnl_unlock();
+		return -EINVAL;
+	}
+
+	i = 0;
+	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
+		if (i < skip_cnt)
+			goto count;
+
+		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
+				  &tipc_genl_family, NLM_F_MULTI,
+				  TIPC_NL_BEARER_GET);
+		if (!hdr)
+			goto done;
+
+		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
+					     TIPC_NLA_UDP_REMOTE);
+		if (err) {
+			genlmsg_cancel(skb, hdr);
+			goto done;
+		}
+		genlmsg_end(skb, hdr);
+count:
+		i++;
+	}
+done:
+	rtnl_unlock();
+	cb->args[0] = bid;
+	cb->args[1] = i;
+
+	return skb->len;
+}
+
 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
 {
 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
diff --git a/net/tipc/udp_media.h b/net/tipc/udp_media.h
index c06326a..281bbae 100644
--- a/net/tipc/udp_media.h
+++ b/net/tipc/udp_media.h
@@ -40,6 +40,7 @@
 
 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr);
 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b);
+int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb);
 
 #endif
 #endif
-- 
2.1.4


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Re: [PATCH net-next 0/7] tipc: introduce UDP replicast

[David Miller]

From: Richard Alpe <richard.alpe@ericsson.com>
Date: Fri, 26 Aug 2016 10:52:49 +0200

> This series introduces UDP replicast. A concept where we emulate multicast by
> sending multiple unicast messages to configured peers. This allows TIPC to be
> used in environments where IP multicast is disabled.
> 
> There is a corresponding patch series for the tipc user space tool that
> allows a user to add remote addresses to the replicast list.

Series applied, thanks.

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