Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Another merge window, another set of networking changes.  I've heard
  rumblings that the lightweight tunnels infrastructure has been voted
  networking change of the year.  But what do I know?

   1) Add conntrack support to openvswitch, from Joe Stringer.

   2) Initial support for VRF (Virtual Routing and Forwarding), which
      allows the segmentation of routing paths without using multiple
      devices.  There are some semantic kinks to work out still, but
      this is a reasonably strong foundation.  From David Ahern.

   3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov.

   4) Ignore route nexthops with a link down state in ipv6, just like
      ipv4.  From Andy Gospodarek.

   5) Remove spinlock from fast path of act_gact and act_mirred, from
      Eric Dumazet.

   6) Document the DSA layer, from Florian Fainelli.

   7) Add netconsole support to bcmgenet, systemport, and DSA.  Also
      from Florian Fainelli.

   8) Add Mellanox Switch Driver and core infrastructure, from Jiri
      Pirko.

   9) Add support for "light weight tunnels", which allow for
      encapsulation and decapsulation without bearing the overhead of a
      full blown netdevice.  From Thomas Graf, Jiri Benc, and a cast of
      others.

  10) Add Identifier Locator Addressing support for ipv6, from Tom
      Herbert.

  11) Support fragmented SKBs in iwlwifi, from Johannes Berg.

  12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia.

  13) Add BQL support to 3c59x driver, from Loganaden Velvindron.

  14) Stop using a zero TX queue length to mean that a device shouldn't
      have a qdisc attached, use an explicit flag instead.  From Phil
      Sutter.

  15) Use generic geneve netdevice infrastructure in openvswitch, from
      Pravin B Shelar.

  16) Add infrastructure to avoid re-forwarding a packet in software
      that was already forwarded by a hardware switch.  From Scott
      Feldman.

  17) Allow AF_PACKET fanout function to be implemented in a bpf
      program, from Willem de Bruijn"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits)
  netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
  netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled
  net: fec: clear receive interrupts before processing a packet
  ipv6: fix exthdrs offload registration in out_rt path
  xen-netback: add support for multicast control
  bgmac: Update fixed_phy_register()
  sock, diag: fix panic in sock_diag_put_filterinfo
  flow_dissector: Use 'const' where possible.
  flow_dissector: Fix function argument ordering dependency
  ixgbe: Resolve "initialized field overwritten" warnings
  ixgbe: Remove bimodal SR-IOV disabling
  ixgbe: Add support for reporting 2.5G link speed
  ixgbe: fix bounds checking in ixgbe_setup_tc for 82598
  ixgbe: support for ethtool set_rxfh
  ixgbe: Avoid needless PHY access on copper phys
  ixgbe: cleanup to use cached mask value
  ixgbe: Remove second instance of lan_id variable
  ixgbe: use kzalloc for allocating one thing
  flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c
  ixgbe: Remove unused PCI bus types
  ...

1 files changed, 174 insertions, 95 deletions

diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index d99ad93eb855..43f140950075 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -262,6 +262,11 @@ struct ip_vs_sync_mesg {
 	/* ip_vs_sync_conn entries start here */
 };
 
+union ipvs_sockaddr {
+	struct sockaddr_in	in;
+	struct sockaddr_in6	in6;
+};
+
 struct ip_vs_sync_buff {
 	struct list_head        list;
 	unsigned long           firstuse;
@@ -320,26 +325,28 @@ sb_dequeue(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
  * Create a new sync buffer for Version 1 proto.
  */
 static inline struct ip_vs_sync_buff *
-ip_vs_sync_buff_create(struct netns_ipvs *ipvs)
+ip_vs_sync_buff_create(struct netns_ipvs *ipvs, unsigned int len)
 {
 	struct ip_vs_sync_buff *sb;
 
 	if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
 		return NULL;
 
-	sb->mesg = kmalloc(ipvs->send_mesg_maxlen, GFP_ATOMIC);
+	len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg),
+		    ipvs->mcfg.sync_maxlen);
+	sb->mesg = kmalloc(len, GFP_ATOMIC);
 	if (!sb->mesg) {
 		kfree(sb);
 		return NULL;
 	}
 	sb->mesg->reserved = 0;  /* old nr_conns i.e. must be zero now */
 	sb->mesg->version = SYNC_PROTO_VER;
-	sb->mesg->syncid = ipvs->master_syncid;
+	sb->mesg->syncid = ipvs->mcfg.syncid;
 	sb->mesg->size = htons(sizeof(struct ip_vs_sync_mesg));
 	sb->mesg->nr_conns = 0;
 	sb->mesg->spare = 0;
 	sb->head = (unsigned char *)sb->mesg + sizeof(struct ip_vs_sync_mesg);
-	sb->end = (unsigned char *)sb->mesg + ipvs->send_mesg_maxlen;
+	sb->end = (unsigned char *)sb->mesg + len;
 
 	sb->firstuse = jiffies;
 	return sb;
@@ -402,7 +409,7 @@ select_master_thread_id(struct netns_ipvs *ipvs, struct ip_vs_conn *cp)
  * Create a new sync buffer for Version 0 proto.
  */
 static inline struct ip_vs_sync_buff *
-ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs)
+ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs, unsigned int len)
 {
 	struct ip_vs_sync_buff *sb;
 	struct ip_vs_sync_mesg_v0 *mesg;
@@ -410,17 +417,19 @@ ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs)
 	if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
 		return NULL;
 
-	sb->mesg = kmalloc(ipvs->send_mesg_maxlen, GFP_ATOMIC);
+	len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg_v0),
+		    ipvs->mcfg.sync_maxlen);
+	sb->mesg = kmalloc(len, GFP_ATOMIC);
 	if (!sb->mesg) {
 		kfree(sb);
 		return NULL;
 	}
 	mesg = (struct ip_vs_sync_mesg_v0 *)sb->mesg;
 	mesg->nr_conns = 0;
-	mesg->syncid = ipvs->master_syncid;
+	mesg->syncid = ipvs->mcfg.syncid;
 	mesg->size = htons(sizeof(struct ip_vs_sync_mesg_v0));
 	sb->head = (unsigned char *)mesg + sizeof(struct ip_vs_sync_mesg_v0);
-	sb->end = (unsigned char *)mesg + ipvs->send_mesg_maxlen;
+	sb->end = (unsigned char *)mesg + len;
 	sb->firstuse = jiffies;
 	return sb;
 }
@@ -533,7 +542,7 @@ static void ip_vs_sync_conn_v0(struct net *net, struct ip_vs_conn *cp,
 	struct ip_vs_sync_buff *buff;
 	struct ipvs_master_sync_state *ms;
 	int id;
-	int len;
+	unsigned int len;
 
 	if (unlikely(cp->af != AF_INET))
 		return;
@@ -553,17 +562,19 @@ static void ip_vs_sync_conn_v0(struct net *net, struct ip_vs_conn *cp,
 	id = select_master_thread_id(ipvs, cp);
 	ms = &ipvs->ms[id];
 	buff = ms->sync_buff;
+	len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
+		SIMPLE_CONN_SIZE;
 	if (buff) {
 		m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
 		/* Send buffer if it is for v1 */
-		if (!m->nr_conns) {
+		if (buff->head + len > buff->end || !m->nr_conns) {
 			sb_queue_tail(ipvs, ms);
 			ms->sync_buff = NULL;
 			buff = NULL;
 		}
 	}
 	if (!buff) {
-		buff = ip_vs_sync_buff_create_v0(ipvs);
+		buff = ip_vs_sync_buff_create_v0(ipvs, len);
 		if (!buff) {
 			spin_unlock_bh(&ipvs->sync_buff_lock);
 			pr_err("ip_vs_sync_buff_create failed.\n");
@@ -572,8 +583,6 @@ static void ip_vs_sync_conn_v0(struct net *net, struct ip_vs_conn *cp,
 		ms->sync_buff = buff;
 	}
 
-	len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
-		SIMPLE_CONN_SIZE;
 	m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
 	s = (struct ip_vs_sync_conn_v0 *) buff->head;
 
@@ -597,12 +606,6 @@ static void ip_vs_sync_conn_v0(struct net *net, struct ip_vs_conn *cp,
 	m->nr_conns++;
 	m->size = htons(ntohs(m->size) + len);
 	buff->head += len;
-
-	/* check if there is a space for next one */
-	if (buff->head + FULL_CONN_SIZE > buff->end) {
-		sb_queue_tail(ipvs, ms);
-		ms->sync_buff = NULL;
-	}
 	spin_unlock_bh(&ipvs->sync_buff_lock);
 
 	/* synchronize its controller if it has */
@@ -694,7 +697,7 @@ sloop:
 	}
 
 	if (!buff) {
-		buff = ip_vs_sync_buff_create(ipvs);
+		buff = ip_vs_sync_buff_create(ipvs, len);
 		if (!buff) {
 			spin_unlock_bh(&ipvs->sync_buff_lock);
 			pr_err("ip_vs_sync_buff_create failed.\n");
@@ -1219,7 +1222,7 @@ static void ip_vs_process_message(struct net *net, __u8 *buffer,
 		return;
 	}
 	/* SyncID sanity check */
-	if (ipvs->backup_syncid != 0 && m2->syncid != ipvs->backup_syncid) {
+	if (ipvs->bcfg.syncid != 0 && m2->syncid != ipvs->bcfg.syncid) {
 		IP_VS_DBG(7, "BACKUP, Ignoring syncid = %d\n", m2->syncid);
 		return;
 	}
@@ -1303,6 +1306,14 @@ static void set_mcast_loop(struct sock *sk, u_char loop)
 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
 	lock_sock(sk);
 	inet->mc_loop = loop ? 1 : 0;
+#ifdef CONFIG_IP_VS_IPV6
+	if (sk->sk_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		/* IPV6_MULTICAST_LOOP */
+		np->mc_loop = loop ? 1 : 0;
+	}
+#endif
 	release_sock(sk);
 }
 
@@ -1316,6 +1327,33 @@ static void set_mcast_ttl(struct sock *sk, u_char ttl)
 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
 	lock_sock(sk);
 	inet->mc_ttl = ttl;
+#ifdef CONFIG_IP_VS_IPV6
+	if (sk->sk_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		/* IPV6_MULTICAST_HOPS */
+		np->mcast_hops = ttl;
+	}
+#endif
+	release_sock(sk);
+}
+
+/* Control fragmentation of messages */
+static void set_mcast_pmtudisc(struct sock *sk, int val)
+{
+	struct inet_sock *inet = inet_sk(sk);
+
+	/* setsockopt(sock, SOL_IP, IP_MTU_DISCOVER, &val, sizeof(val)); */
+	lock_sock(sk);
+	inet->pmtudisc = val;
+#ifdef CONFIG_IP_VS_IPV6
+	if (sk->sk_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		/* IPV6_MTU_DISCOVER */
+		np->pmtudisc = val;
+	}
+#endif
 	release_sock(sk);
 }
 
@@ -1338,44 +1376,15 @@ static int set_mcast_if(struct sock *sk, char *ifname)
 	lock_sock(sk);
 	inet->mc_index = dev->ifindex;
 	/*  inet->mc_addr  = 0; */
-	release_sock(sk);
-
-	return 0;
-}
-
+#ifdef CONFIG_IP_VS_IPV6
+	if (sk->sk_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
 
-/*
- *	Set the maximum length of sync message according to the
- *	specified interface's MTU.
- */
-static int set_sync_mesg_maxlen(struct net *net, int sync_state)
-{
-	struct netns_ipvs *ipvs = net_ipvs(net);
-	struct net_device *dev;
-	int num;
-
-	if (sync_state == IP_VS_STATE_MASTER) {
-		dev = __dev_get_by_name(net, ipvs->master_mcast_ifn);
-		if (!dev)
-			return -ENODEV;
-
-		num = (dev->mtu - sizeof(struct iphdr) -
-		       sizeof(struct udphdr) -
-		       SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
-		ipvs->send_mesg_maxlen = SYNC_MESG_HEADER_LEN +
-			SIMPLE_CONN_SIZE * min(num, MAX_CONNS_PER_SYNCBUFF);
-		IP_VS_DBG(7, "setting the maximum length of sync sending "
-			  "message %d.\n", ipvs->send_mesg_maxlen);
-	} else if (sync_state == IP_VS_STATE_BACKUP) {
-		dev = __dev_get_by_name(net, ipvs->backup_mcast_ifn);
-		if (!dev)
-			return -ENODEV;
-
-		ipvs->recv_mesg_maxlen = dev->mtu -
-			sizeof(struct iphdr) - sizeof(struct udphdr);
-		IP_VS_DBG(7, "setting the maximum length of sync receiving "
-			  "message %d.\n", ipvs->recv_mesg_maxlen);
+		/* IPV6_MULTICAST_IF */
+		np->mcast_oif = dev->ifindex;
 	}
+#endif
+	release_sock(sk);
 
 	return 0;
 }
@@ -1405,15 +1414,34 @@ join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
 
 	mreq.imr_ifindex = dev->ifindex;
 
-	rtnl_lock();
 	lock_sock(sk);
 	ret = ip_mc_join_group(sk, &mreq);
 	release_sock(sk);
-	rtnl_unlock();
 
 	return ret;
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
+			     char *ifname)
+{
+	struct net *net = sock_net(sk);
+	struct net_device *dev;
+	int ret;
+
+	dev = __dev_get_by_name(net, ifname);
+	if (!dev)
+		return -ENODEV;
+	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
+		return -EINVAL;
+
+	lock_sock(sk);
+	ret = ipv6_sock_mc_join(sk, dev->ifindex, addr);
+	release_sock(sk);
+
+	return ret;
+}
+#endif
 
 static int bind_mcastif_addr(struct socket *sock, char *ifname)
 {
@@ -1442,6 +1470,26 @@ static int bind_mcastif_addr(struct socket *sock, char *ifname)
 	return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
 }
 
+static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
+			       struct ipvs_sync_daemon_cfg *c, int id)
+{
+	if (AF_INET6 == c->mcast_af) {
+		sa->in6 = (struct sockaddr_in6) {
+			.sin6_family = AF_INET6,
+			.sin6_port = htons(c->mcast_port + id),
+		};
+		sa->in6.sin6_addr = c->mcast_group.in6;
+		*salen = sizeof(sa->in6);
+	} else {
+		sa->in = (struct sockaddr_in) {
+			.sin_family = AF_INET,
+			.sin_port = htons(c->mcast_port + id),
+		};
+		sa->in.sin_addr = c->mcast_group.in;
+		*salen = sizeof(sa->in);
+	}
+}
+
 /*
  *      Set up sending multicast socket over UDP
  */
@@ -1449,40 +1497,43 @@ static struct socket *make_send_sock(struct net *net, int id)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
 	/* multicast addr */
-	struct sockaddr_in mcast_addr = {
-		.sin_family		= AF_INET,
-		.sin_port		= cpu_to_be16(IP_VS_SYNC_PORT + id),
-		.sin_addr.s_addr	= cpu_to_be32(IP_VS_SYNC_GROUP),
-	};
+	union ipvs_sockaddr mcast_addr;
 	struct socket *sock;
-	int result;
+	int result, salen;
 
 	/* First create a socket */
-	result = sock_create_kern(net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
+	result = sock_create_kern(net, ipvs->mcfg.mcast_af, SOCK_DGRAM,
+				  IPPROTO_UDP, &sock);
 	if (result < 0) {
 		pr_err("Error during creation of socket; terminating\n");
 		return ERR_PTR(result);
 	}
-	result = set_mcast_if(sock->sk, ipvs->master_mcast_ifn);
+	result = set_mcast_if(sock->sk, ipvs->mcfg.mcast_ifn);
 	if (result < 0) {
 		pr_err("Error setting outbound mcast interface\n");
 		goto error;
 	}
 
 	set_mcast_loop(sock->sk, 0);
-	set_mcast_ttl(sock->sk, 1);
+	set_mcast_ttl(sock->sk, ipvs->mcfg.mcast_ttl);
+	/* Allow fragmentation if MTU changes */
+	set_mcast_pmtudisc(sock->sk, IP_PMTUDISC_DONT);
 	result = sysctl_sync_sock_size(ipvs);
 	if (result > 0)
 		set_sock_size(sock->sk, 1, result);
 
-	result = bind_mcastif_addr(sock, ipvs->master_mcast_ifn);
+	if (AF_INET == ipvs->mcfg.mcast_af)
+		result = bind_mcastif_addr(sock, ipvs->mcfg.mcast_ifn);
+	else
+		result = 0;
 	if (result < 0) {
 		pr_err("Error binding address of the mcast interface\n");
 		goto error;
 	}
 
+	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->mcfg, id);
 	result = sock->ops->connect(sock, (struct sockaddr *) &mcast_addr,
-			sizeof(struct sockaddr), 0);
+				    salen, 0);
 	if (result < 0) {
 		pr_err("Error connecting to the multicast addr\n");
 		goto error;
@@ -1503,16 +1554,13 @@ static struct socket *make_receive_sock(struct net *net, int id)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
 	/* multicast addr */
-	struct sockaddr_in mcast_addr = {
-		.sin_family		= AF_INET,
-		.sin_port		= cpu_to_be16(IP_VS_SYNC_PORT + id),
-		.sin_addr.s_addr	= cpu_to_be32(IP_VS_SYNC_GROUP),
-	};
+	union ipvs_sockaddr mcast_addr;
 	struct socket *sock;
-	int result;
+	int result, salen;
 
 	/* First create a socket */
-	result = sock_create_kern(net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
+	result = sock_create_kern(net, ipvs->bcfg.mcast_af, SOCK_DGRAM,
+				  IPPROTO_UDP, &sock);
 	if (result < 0) {
 		pr_err("Error during creation of socket; terminating\n");
 		return ERR_PTR(result);
@@ -1523,17 +1571,22 @@ static struct socket *make_receive_sock(struct net *net, int id)
 	if (result > 0)
 		set_sock_size(sock->sk, 0, result);
 
-	result = sock->ops->bind(sock, (struct sockaddr *) &mcast_addr,
-			sizeof(struct sockaddr));
+	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
+	result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen);
 	if (result < 0) {
 		pr_err("Error binding to the multicast addr\n");
 		goto error;
 	}
 
 	/* join the multicast group */
-	result = join_mcast_group(sock->sk,
-			(struct in_addr *) &mcast_addr.sin_addr,
-			ipvs->backup_mcast_ifn);
+#ifdef CONFIG_IP_VS_IPV6
+	if (ipvs->bcfg.mcast_af == AF_INET6)
+		result = join_mcast_group6(sock->sk, &mcast_addr.in6.sin6_addr,
+					   ipvs->bcfg.mcast_ifn);
+	else
+#endif
+		result = join_mcast_group(sock->sk, &mcast_addr.in.sin_addr,
+					  ipvs->bcfg.mcast_ifn);
 	if (result < 0) {
 		pr_err("Error joining to the multicast group\n");
 		goto error;
@@ -1641,7 +1694,7 @@ static int sync_thread_master(void *data)
 
 	pr_info("sync thread started: state = MASTER, mcast_ifn = %s, "
 		"syncid = %d, id = %d\n",
-		ipvs->master_mcast_ifn, ipvs->master_syncid, tinfo->id);
+		ipvs->mcfg.mcast_ifn, ipvs->mcfg.syncid, tinfo->id);
 
 	for (;;) {
 		sb = next_sync_buff(ipvs, ms);
@@ -1695,7 +1748,7 @@ static int sync_thread_backup(void *data)
 
 	pr_info("sync thread started: state = BACKUP, mcast_ifn = %s, "
 		"syncid = %d, id = %d\n",
-		ipvs->backup_mcast_ifn, ipvs->backup_syncid, tinfo->id);
+		ipvs->bcfg.mcast_ifn, ipvs->bcfg.syncid, tinfo->id);
 
 	while (!kthread_should_stop()) {
 		wait_event_interruptible(*sk_sleep(tinfo->sock->sk),
@@ -1705,7 +1758,7 @@ static int sync_thread_backup(void *data)
 		/* do we have data now? */
 		while (!skb_queue_empty(&(tinfo->sock->sk->sk_receive_queue))) {
 			len = ip_vs_receive(tinfo->sock, tinfo->buf,
-					ipvs->recv_mesg_maxlen);
+					ipvs->bcfg.sync_maxlen);
 			if (len <= 0) {
 				if (len != -EAGAIN)
 					pr_err("receiving message error\n");
@@ -1725,16 +1778,19 @@ static int sync_thread_backup(void *data)
 }
 
 
-int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid)
+int start_sync_thread(struct net *net, struct ipvs_sync_daemon_cfg *c,
+		      int state)
 {
 	struct ip_vs_sync_thread_data *tinfo;
 	struct task_struct **array = NULL, *task;
 	struct socket *sock;
 	struct netns_ipvs *ipvs = net_ipvs(net);
+	struct net_device *dev;
 	char *name;
 	int (*threadfn)(void *data);
-	int id, count;
+	int id, count, hlen;
 	int result = -ENOMEM;
+	u16 mtu, min_mtu;
 
 	IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
 	IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %Zd bytes\n",
@@ -1746,22 +1802,46 @@ int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid)
 	} else
 		count = ipvs->threads_mask + 1;
 
+	if (c->mcast_af == AF_UNSPEC) {
+		c->mcast_af = AF_INET;
+		c->mcast_group.ip = cpu_to_be32(IP_VS_SYNC_GROUP);
+	}
+	if (!c->mcast_port)
+		c->mcast_port = IP_VS_SYNC_PORT;
+	if (!c->mcast_ttl)
+		c->mcast_ttl = 1;
+
+	dev = __dev_get_by_name(net, c->mcast_ifn);
+	if (!dev) {
+		pr_err("Unknown mcast interface: %s\n", c->mcast_ifn);
+		return -ENODEV;
+	}
+	hlen = (AF_INET6 == c->mcast_af) ?
+	       sizeof(struct ipv6hdr) + sizeof(struct udphdr) :
+	       sizeof(struct iphdr) + sizeof(struct udphdr);
+	mtu = (state == IP_VS_STATE_BACKUP) ?
+		  clamp(dev->mtu, 1500U, 65535U) : 1500U;
+	min_mtu = (state == IP_VS_STATE_BACKUP) ? 1024 : 1;
+
+	if (c->sync_maxlen)
+		c->sync_maxlen = clamp_t(unsigned int,
+					 c->sync_maxlen, min_mtu,
+					 65535 - hlen);
+	else
+		c->sync_maxlen = mtu - hlen;
+
 	if (state == IP_VS_STATE_MASTER) {
 		if (ipvs->ms)
 			return -EEXIST;
 
-		strlcpy(ipvs->master_mcast_ifn, mcast_ifn,
-			sizeof(ipvs->master_mcast_ifn));
-		ipvs->master_syncid = syncid;
+		ipvs->mcfg = *c;
 		name = "ipvs-m:%d:%d";
 		threadfn = sync_thread_master;
 	} else if (state == IP_VS_STATE_BACKUP) {
 		if (ipvs->backup_threads)
 			return -EEXIST;
 
-		strlcpy(ipvs->backup_mcast_ifn, mcast_ifn,
-			sizeof(ipvs->backup_mcast_ifn));
-		ipvs->backup_syncid = syncid;
+		ipvs->bcfg = *c;
 		name = "ipvs-b:%d:%d";
 		threadfn = sync_thread_backup;
 	} else {
@@ -1789,7 +1869,6 @@ int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid)
 		if (!array)
 			goto out;
 	}
-	set_sync_mesg_maxlen(net, state);
 
 	tinfo = NULL;
 	for (id = 0; id < count; id++) {
@@ -1807,7 +1886,7 @@ int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid)
 		tinfo->net = net;
 		tinfo->sock = sock;
 		if (state == IP_VS_STATE_BACKUP) {
-			tinfo->buf = kmalloc(ipvs->recv_mesg_maxlen,
+			tinfo->buf = kmalloc(ipvs->bcfg.sync_maxlen,
 					     GFP_KERNEL);
 			if (!tinfo->buf)
 				goto outtinfo;