Merge branch 'tipc-next'

Jon Maloy says:

====================
tipc: bug fixes and improvements

Intensive and extensive testing has revealed some rather infrequent
problems related to flow control, buffer handling and link
establishment. Commits ##1 to 4 deal with these problems.

The remaining four commits are just code improvments, aiming at
making the code more comprehensible and maintainable. There are
no functional enhancements in this series.

v2: Fixed a typo in commit log #2. Otherwise no changes from v1.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

19 files changed, 348 insertions, 351 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index a0978d0890cb..671f9817b4f4 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -506,18 +506,14 @@ receive:
 			tipc_node_unlock(node);
 			tipc_link_bundle_rcv(buf);
 		} else if (msg_user(msg) == MSG_FRAGMENTER) {
-			int ret;
-			ret = tipc_link_frag_rcv(&node->bclink.reasm_head,
-						 &node->bclink.reasm_tail,
-						 &buf);
-			if (ret == LINK_REASM_ERROR)
+			tipc_buf_append(&node->bclink.reasm_buf, &buf);
+			if (unlikely(!buf && !node->bclink.reasm_buf))
 				goto unlock;
 			tipc_bclink_lock();
 			bclink_accept_pkt(node, seqno);
 			bcl->stats.recv_fragments++;
-			if (ret == LINK_REASM_COMPLETE) {
+			if (buf) {
 				bcl->stats.recv_fragmented++;
-				/* Point msg to inner header */
 				msg = buf_msg(buf);
 				tipc_bclink_unlock();
 				goto receive;
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index f3259d4133b6..264474394f9f 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -411,28 +411,6 @@ int tipc_disable_bearer(const char *name)
 	return res;
 }
 
-
-/* tipc_l2_media_addr_set - initialize Ethernet media address structure
- *
- * Media-dependent "value" field stores MAC address in first 6 bytes
- * and zeroes out the remaining bytes.
- */
-void tipc_l2_media_addr_set(const struct tipc_bearer *b,
-			    struct tipc_media_addr *a, char *mac)
-{
-	int len = b->media->hwaddr_len;
-
-	if (unlikely(sizeof(a->value) < len)) {
-		WARN_ONCE(1, "Media length invalid\n");
-		return;
-	}
-
-	memcpy(a->value, mac, len);
-	memset(a->value + len, 0, sizeof(a->value) - len);
-	a->media_id = b->media->type_id;
-	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
-}
-
 int tipc_enable_l2_media(struct tipc_bearer *b)
 {
 	struct net_device *dev;
@@ -443,21 +421,21 @@ int tipc_enable_l2_media(struct tipc_bearer *b)
 	if (!dev)
 		return -ENODEV;
 
-	/* Associate TIPC bearer with Ethernet bearer */
+	/* Associate TIPC bearer with L2 bearer */
 	rcu_assign_pointer(b->media_ptr, dev);
-	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
+	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
 	b->bcast_addr.media_id = b->media->type_id;
 	b->bcast_addr.broadcast = 1;
 	b->mtu = dev->mtu;
-	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
+	b->media->raw2addr(b, &b->addr, (char *)dev->dev_addr);
 	rcu_assign_pointer(dev->tipc_ptr, b);
 	return 0;
 }
 
-/* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
+/* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
  *
- * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
+ * Mark L2 bearer as inactive so that incoming buffers are thrown away,
  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
  * here because cleanup code needs to sleep and caller holds spinlocks.)
  */
@@ -473,7 +451,7 @@ void tipc_disable_l2_media(struct tipc_bearer *b)
 }
 
 /**
- * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
+ * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
  * @buf: the packet to be sent
  * @b_ptr: the bearer through which the packet is to be sent
  * @dest: peer destination address
@@ -597,7 +575,7 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
 		tipc_reset_bearer(b_ptr);
 		break;
 	case NETDEV_CHANGEADDR:
-		tipc_l2_media_addr_set(b_ptr, &b_ptr->addr,
+		b_ptr->media->raw2addr(b_ptr, &b_ptr->addr,
 				       (char *)dev->dev_addr);
 		tipc_reset_bearer(b_ptr);
 		break;
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index a983b3005e71..78fccc49de23 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -42,14 +42,12 @@
 #define MAX_BEARERS	2
 #define MAX_MEDIA	2
 
-/*
- * Identifiers associated with TIPC message header media address info
- *
- * - address info field is 20 bytes long
- * - media type identifier located at offset 3
- * - remaining bytes vary according to media type
+/* Identifiers associated with TIPC message header media address info
+ * - address info field is 32 bytes long
+ * - the field's actual content and length is defined per media
+ * - remaining unused bytes in the field are set to zero
  */
-#define TIPC_MEDIA_ADDR_SIZE	20
+#define TIPC_MEDIA_ADDR_SIZE	32
 #define TIPC_MEDIA_TYPE_OFFSET	3
 
 /*
@@ -77,9 +75,10 @@ struct tipc_bearer;
  * @send_msg: routine which handles buffer transmission
  * @enable_media: routine which enables a media
  * @disable_media: routine which disables a media
- * @addr2str: routine which converts media address to string
- * @addr2msg: routine which converts media address to protocol message area
- * @msg2addr: routine which converts media address from protocol message area
+ * @addr2str: convert media address format to string
+ * @addr2msg: convert from media addr format to discovery msg addr format
+ * @msg2addr: convert from discovery msg addr format to media addr format
+ * @raw2addr: convert from raw addr format to media addr format
  * @priority: default link (and bearer) priority
  * @tolerance: default time (in ms) before declaring link failure
  * @window: default window (in packets) before declaring link congestion
@@ -93,10 +92,16 @@ struct tipc_media {
 			struct tipc_media_addr *dest);
 	int (*enable_media)(struct tipc_bearer *b_ptr);
 	void (*disable_media)(struct tipc_bearer *b_ptr);
-	int (*addr2str)(struct tipc_media_addr *a, char *str_buf, int str_size);
-	int (*addr2msg)(struct tipc_media_addr *a, char *msg_area);
-	int (*msg2addr)(const struct tipc_bearer *b_ptr,
-			struct tipc_media_addr *a, char *msg_area);
+	int (*addr2str)(struct tipc_media_addr *addr,
+			char *strbuf,
+			int bufsz);
+	int (*addr2msg)(char *msg, struct tipc_media_addr *addr);
+	int (*msg2addr)(struct tipc_bearer *b,
+			struct tipc_media_addr *addr,
+			char *msg);
+	int (*raw2addr)(struct tipc_bearer *b,
+			struct tipc_media_addr *addr,
+			char *raw);
 	u32 priority;
 	u32 tolerance;
 	u32 window;
@@ -175,8 +180,6 @@ int tipc_media_set_priority(const char *name, u32 new_value);
 int tipc_media_set_window(const char *name, u32 new_value);
 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a);
 struct sk_buff *tipc_media_get_names(void);
-void tipc_l2_media_addr_set(const struct tipc_bearer *b,
-			    struct tipc_media_addr *a, char *mac);
 int tipc_enable_l2_media(struct tipc_bearer *b);
 void tipc_disable_l2_media(struct tipc_bearer *b);
 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
diff --git a/net/tipc/core.c b/net/tipc/core.c
index 57f8ae9aa466..676d18015dd8 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -154,10 +154,11 @@ static int __init tipc_init(void)
 	tipc_max_ports = CONFIG_TIPC_PORTS;
 	tipc_net_id = 4711;
 
-	sysctl_tipc_rmem[0] = CONN_OVERLOAD_LIMIT >> 4 << TIPC_LOW_IMPORTANCE;
-	sysctl_tipc_rmem[1] = CONN_OVERLOAD_LIMIT >> 4 <<
+	sysctl_tipc_rmem[0] = TIPC_CONN_OVERLOAD_LIMIT >> 4 <<
+			      TIPC_LOW_IMPORTANCE;
+	sysctl_tipc_rmem[1] = TIPC_CONN_OVERLOAD_LIMIT >> 4 <<
 			      TIPC_CRITICAL_IMPORTANCE;
-	sysctl_tipc_rmem[2] = CONN_OVERLOAD_LIMIT;
+	sysctl_tipc_rmem[2] = TIPC_CONN_OVERLOAD_LIMIT;
 
 	res = tipc_core_start();
 	if (res)
diff --git a/net/tipc/core.h b/net/tipc/core.h
index ae55d37267e6..bb26ed1ee966 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -57,6 +57,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/rtnetlink.h>
+#include <linux/etherdevice.h>
 
 #define TIPC_MOD_VER "2.0.0"
 
@@ -187,6 +188,7 @@ static inline void k_term_timer(struct timer_list *timer)
 struct tipc_skb_cb {
 	void *handle;
 	bool deferred;
+	struct sk_buff *tail;
 };
 
 #define TIPC_SKB_CB(__skb) ((struct tipc_skb_cb *)&((__skb)->cb[0]))
diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index bd35c4a0746f..aa722a42ef8b 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/discover.c
  *
- * Copyright (c) 2003-2006, Ericsson AB
+ * Copyright (c) 2003-2006, 2014, Ericsson AB
  * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
  * All rights reserved.
  *
@@ -83,7 +83,7 @@ static void tipc_disc_init_msg(struct sk_buff *buf, u32 type,
 	msg_set_node_sig(msg, tipc_random);
 	msg_set_dest_domain(msg, dest_domain);
 	msg_set_bc_netid(msg, tipc_net_id);
-	b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg));
+	b_ptr->media->addr2msg(msg_media_addr(msg), &b_ptr->addr);
 }
 
 /**
@@ -106,147 +106,150 @@ static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
 }
 
 /**
- * tipc_disc_rcv - handle incoming link setup message (request or response)
+ * tipc_disc_rcv - handle incoming discovery message (request or response)
  * @buf: buffer containing message
- * @b_ptr: bearer that message arrived on
+ * @bearer: bearer that message arrived on
  */
-void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *b_ptr)
+void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *bearer)
 {
-	struct tipc_node *n_ptr;
+	struct tipc_node *node;
 	struct tipc_link *link;
-	struct tipc_media_addr media_addr;
+	struct tipc_media_addr maddr;
 	struct sk_buff *rbuf;
 	struct tipc_msg *msg = buf_msg(buf);
-	u32 dest = msg_dest_domain(msg);
-	u32 orig = msg_prevnode(msg);
+	u32 ddom = msg_dest_domain(msg);
+	u32 onode = msg_prevnode(msg);
 	u32 net_id = msg_bc_netid(msg);
-	u32 type = msg_type(msg);
+	u32 mtyp = msg_type(msg);
 	u32 signature = msg_node_sig(msg);
-	int addr_mismatch;
-	int link_fully_up;
-
-	media_addr.broadcast = 1;
-	b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg));
+	bool addr_match = false;
+	bool sign_match = false;
+	bool link_up = false;
+	bool accept_addr = false;
+	bool accept_sign = false;
+	bool respond = false;
+
+	bearer->media->msg2addr(bearer, &maddr, msg_media_addr(msg));
 	kfree_skb(buf);
 
 	/* Ensure message from node is valid and communication is permitted */
 	if (net_id != tipc_net_id)
 		return;
-	if (media_addr.broadcast)
+	if (maddr.broadcast)
 		return;
-	if (!tipc_addr_domain_valid(dest))
+	if (!tipc_addr_domain_valid(ddom))
 		return;
-	if (!tipc_addr_node_valid(orig))
+	if (!tipc_addr_node_valid(onode))
 		return;
-	if (orig == tipc_own_addr) {
-		if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
-			disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
+
+	if (in_own_node(onode)) {
+		if (memcmp(&maddr, &bearer->addr, sizeof(maddr)))
+			disc_dupl_alert(bearer, tipc_own_addr, &maddr);
 		return;
 	}
-	if (!tipc_in_scope(dest, tipc_own_addr))
+	if (!tipc_in_scope(ddom, tipc_own_addr))
 		return;
-	if (!tipc_in_scope(b_ptr->domain, orig))
+	if (!tipc_in_scope(bearer->domain, onode))
 		return;
 
-	/* Locate structure corresponding to requesting node */
-	n_ptr = tipc_node_find(orig);
-	if (!n_ptr) {
-		n_ptr = tipc_node_create(orig);
-		if (!n_ptr)
-			return;
-	}
-	tipc_node_lock(n_ptr);
+	/* Locate, or if necessary, create, node: */
+	node = tipc_node_find(onode);
+	if (!node)
+		node = tipc_node_create(onode);
+	if (!node)
+		return;
 
-	/* Prepare to validate requesting node's signature and media address */
-	link = n_ptr->links[b_ptr->identity];
-	addr_mismatch = (link != NULL) &&
-		memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
+	tipc_node_lock(node);
+	link = node->links[bearer->identity];
 
-	/*
-	 * Ensure discovery message's signature is correct
-	 *
-	 * If signature is incorrect and there is no working link to the node,
-	 * accept the new signature but invalidate all existing links to the
-	 * node so they won't re-activate without a new discovery message.
-	 *
-	 * If signature is incorrect and the requested link to the node is
-	 * working, accept the new signature. (This is an instance of delayed
-	 * rediscovery, where a link endpoint was able to re-establish contact
-	 * with its peer endpoint on a node that rebooted before receiving a
-	 * discovery message from that node.)
-	 *
-	 * If signature is incorrect and there is a working link to the node
-	 * that is not the requested link, reject the request (must be from
-	 * a duplicate node).
-	 */
-	if (signature != n_ptr->signature) {
-		if (n_ptr->working_links == 0) {
-			struct tipc_link *curr_link;
-			int i;
-
-			for (i = 0; i < MAX_BEARERS; i++) {
-				curr_link = n_ptr->links[i];
-				if (curr_link) {
-					memset(&curr_link->media_addr, 0,
-					       sizeof(media_addr));
-					tipc_link_reset(curr_link);
-				}
-			}
-			addr_mismatch = (link != NULL);
-		} else if (tipc_link_is_up(link) && !addr_mismatch) {
-			/* delayed rediscovery */
-		} else {
-			disc_dupl_alert(b_ptr, orig, &media_addr);
-			tipc_node_unlock(n_ptr);
-			return;
-		}
-		n_ptr->signature = signature;
+	/* Prepare to validate requesting node's signature and media address */
+	sign_match = (signature == node->signature);
+	addr_match = link && !memcmp(&link->media_addr, &maddr, sizeof(maddr));
+	link_up = link && tipc_link_is_up(link);
+
+
+	/* These three flags give us eight permutations: */
+
+	if (sign_match && addr_match && link_up) {
+		/* All is fine. Do nothing. */
+	} else if (sign_match && addr_match && !link_up) {
+		/* Respond. The link will come up in due time */
+		respond = true;
+	} else if (sign_match && !addr_match && link_up) {
+		/* Peer has changed i/f address without rebooting.
+		 * If so, the link will reset soon, and the next
+		 * discovery will be accepted. So we can ignore it.
+		 * It may also be an cloned or malicious peer having
+		 * chosen the same node address and signature as an
+		 * existing one.
+		 * Ignore requests until the link goes down, if ever.
+		 */
+		disc_dupl_alert(bearer, onode, &maddr);
+	} else if (sign_match && !addr_match && !link_up) {
+		/* Peer link has changed i/f address without rebooting.
+		 * It may also be a cloned or malicious peer; we can't
+		 * distinguish between the two.
+		 * The signature is correct, so we must accept.
+		 */
+		accept_addr = true;
+		respond = true;
+	} else if (!sign_match && addr_match && link_up) {
+		/* Peer node rebooted. Two possibilities:
+		 *  - Delayed re-discovery; this link endpoint has already
+		 *    reset and re-established contact with the peer, before
+		 *    receiving a discovery message from that node.
+		 *    (The peer happened to receive one from this node first).
+		 *  - The peer came back so fast that our side has not
+		 *    discovered it yet. Probing from this side will soon
+		 *    reset the link, since there can be no working link
+		 *    endpoint at the peer end, and the link will re-establish.
+		 *  Accept the signature, since it comes from a known peer.
+		 */
+		accept_sign = true;
+	} else if (!sign_match && addr_match && !link_up) {
+		/*  The peer node has rebooted.
+		 *  Accept signature, since it is a known peer.
+		 */
+		accept_sign = true;
+		respond = true;
+	} else if (!sign_match && !addr_match && link_up) {
+		/* Peer rebooted with new address, or a new/duplicate peer.
+		 * Ignore until the link goes down, if ever.
+		 */
+		disc_dupl_alert(bearer, onode, &maddr);
+	} else if (!sign_match && !addr_match && !link_up) {
+		/* Peer rebooted with new address, or it is a new peer.
+		 * Accept signature and address.
+		*/
+		accept_sign = true;
+		accept_addr = true;
+		respond = true;
 	}
 
-	/*
-	 * Ensure requesting node's media address is correct
-	 *
-	 * If media address doesn't match and the link is working, reject the
-	 * request (must be from a duplicate node).
-	 *
-	 * If media address doesn't match and the link is not working, accept
-	 * the new media address and reset the link to ensure it starts up
-	 * cleanly.
-	 */
-	if (addr_mismatch) {
-		if (tipc_link_is_up(link)) {
-			disc_dupl_alert(b_ptr, orig, &media_addr);
-			tipc_node_unlock(n_ptr);
-			return;
-		} else {
-			memcpy(&link->media_addr, &media_addr,
-			       sizeof(media_addr));
-			tipc_link_reset(link);
-		}
-	}
+	if (accept_sign)
+		node->signature = signature;
 
-	/* Create a link endpoint for this bearer, if necessary */
-	if (!link) {
-		link = tipc_link_create(n_ptr, b_ptr, &media_addr);
-		if (!link) {
-			tipc_node_unlock(n_ptr);
-			return;
+	if (accept_addr) {
+		if (!link)
+			link = tipc_link_create(node, bearer, &maddr);
+		if (link) {
+			memcpy(&link->media_addr, &maddr, sizeof(maddr));
+			tipc_link_reset(link);
+		} else {
+			respond = false;
 		}
 	}
 
-	/* Accept discovery message & send response, if necessary */
-	link_fully_up = link_working_working(link);
-
-	if ((type == DSC_REQ_MSG) && !link_fully_up) {
+	/* Send response, if necessary */
+	if (respond && (mtyp == DSC_REQ_MSG)) {
 		rbuf = tipc_buf_acquire(INT_H_SIZE);
 		if (rbuf) {
-			tipc_disc_init_msg(rbuf, DSC_RESP_MSG, b_ptr);
-			tipc_bearer_send(b_ptr->identity, rbuf, &media_addr);
+			tipc_disc_init_msg(rbuf, DSC_RESP_MSG, bearer);
+			tipc_bearer_send(bearer->identity, rbuf, &maddr);
 			kfree_skb(rbuf);
 		}
 	}
-
-	tipc_node_unlock(n_ptr);
+	tipc_node_unlock(node);
 }
 
 /**
diff --git a/net/tipc/eth_media.c b/net/tipc/eth_media.c
index 67cf3f935dba..5e1426f1751f 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/eth_media.c: Ethernet bearer support for TIPC
  *
- * Copyright (c) 2001-2007, 2013, Ericsson AB
+ * Copyright (c) 2001-2007, 2013-2014, Ericsson AB
  * Copyright (c) 2005-2008, 2011-2013, Wind River Systems
  * All rights reserved.
  *
@@ -37,39 +37,52 @@
 #include "core.h"
 #include "bearer.h"
 
-#define ETH_ADDR_OFFSET	4	/* message header offset of MAC address */
+#define ETH_ADDR_OFFSET  4  /* MAC addr position inside address field */
 
-/* convert Ethernet address to string */
-static int tipc_eth_addr2str(struct tipc_media_addr *a, char *str_buf,
-			     int str_size)
+/* Convert Ethernet address (media address format) to string */
+static int tipc_eth_addr2str(struct tipc_media_addr *addr,
+			     char *strbuf, int bufsz)
 {
-	if (str_size < 18)	/* 18 = strlen("aa:bb:cc:dd:ee:ff\0") */
+	if (bufsz < 18)	/* 18 = strlen("aa:bb:cc:dd:ee:ff\0") */
 		return 1;
 
-	sprintf(str_buf, "%pM", a->value);
+	sprintf(strbuf, "%pM", addr->value);
 	return 0;
 }
 
-/* convert Ethernet address format to message header format */
-static int tipc_eth_addr2msg(struct tipc_media_addr *a, char *msg_area)
+/* Convert from media address format to discovery message addr format */
+static int tipc_eth_addr2msg(char *msg, struct tipc_media_addr *addr)
 {
-	memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
-	msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_ETH;
-	memcpy(msg_area + ETH_ADDR_OFFSET, a->value, ETH_ALEN);
+	memset(msg, 0, TIPC_MEDIA_ADDR_SIZE);
+	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_ETH;
+	memcpy(msg + ETH_ADDR_OFFSET, addr->value, ETH_ALEN);
 	return 0;
 }
 
-/* convert message header address format to Ethernet format */
-static int tipc_eth_msg2addr(const struct tipc_bearer *tb_ptr,
-			     struct tipc_media_addr *a, char *msg_area)
+/* Convert raw mac address format to media addr format */
+static int tipc_eth_raw2addr(struct tipc_bearer *b,
+			     struct tipc_media_addr *addr,
+			     char *msg)
 {
-	if (msg_area[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_ETH)
-		return 1;
+	char bcast_mac[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
-	tipc_l2_media_addr_set(tb_ptr, a, msg_area + ETH_ADDR_OFFSET);
+	memset(addr, 0, sizeof(*addr));
+	ether_addr_copy(addr->value, msg);
+	addr->media_id = TIPC_MEDIA_TYPE_ETH;
+	addr->broadcast = !memcmp(addr->value, bcast_mac, ETH_ALEN);
 	return 0;
 }
 
+/* Convert discovery msg addr format to Ethernet media addr format */
+static int tipc_eth_msg2addr(struct tipc_bearer *b,
+			     struct tipc_media_addr *addr,
+			     char *msg)
+{
+	/* Skip past preamble: */
+	msg += ETH_ADDR_OFFSET;
+	return tipc_eth_raw2addr(b, addr, msg);
+}
+
 /* Ethernet media registration info */
 struct tipc_media eth_media_info = {
 	.send_msg	= tipc_l2_send_msg,
@@ -78,6 +91,7 @@ struct tipc_media eth_media_info = {
 	.addr2str	= tipc_eth_addr2str,
 	.addr2msg	= tipc_eth_addr2msg,
 	.msg2addr	= tipc_eth_msg2addr,
+	.raw2addr	= tipc_eth_raw2addr,
 	.priority	= TIPC_DEF_LINK_PRI,
 	.tolerance	= TIPC_DEF_LINK_TOL,
 	.window		= TIPC_DEF_LINK_WIN,
@@ -85,4 +99,3 @@ struct tipc_media eth_media_info = {
 	.hwaddr_len	= ETH_ALEN,
 	.name		= "eth"
 };
-
diff --git a/net/tipc/ib_media.c b/net/tipc/ib_media.c
index 844a77e25828..8522eef9c136 100644
--- a/net/tipc/ib_media.c
+++ b/net/tipc/ib_media.c
@@ -42,7 +42,7 @@
 #include "core.h"
 #include "bearer.h"
 
-/* convert InfiniBand address to string */
+/* convert InfiniBand address (media address format) media address to string */
 static int tipc_ib_addr2str(struct tipc_media_addr *a, char *str_buf,
 			    int str_size)
 {
@@ -54,23 +54,35 @@ static int tipc_ib_addr2str(struct tipc_media_addr *a, char *str_buf,
 	return 0;
 }
 
-/* convert InfiniBand address format to message header format */
-static int tipc_ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
+/* Convert from media address format to discovery message addr format */
+static int tipc_ib_addr2msg(char *msg, struct tipc_media_addr *addr)
 {
-	memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
-	msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
-	memcpy(msg_area, a->value, INFINIBAND_ALEN);
+	memset(msg, 0, TIPC_MEDIA_ADDR_SIZE);
+	memcpy(msg, addr->value, INFINIBAND_ALEN);
 	return 0;
 }
 
-/* convert message header address format to InfiniBand format */
-static int tipc_ib_msg2addr(const struct tipc_bearer *tb_ptr,
-			    struct tipc_media_addr *a, char *msg_area)
+/* Convert raw InfiniBand address format to media addr format */
+static int tipc_ib_raw2addr(struct tipc_bearer *b,
+			    struct tipc_media_addr *addr,
+			    char *msg)
 {
-	tipc_l2_media_addr_set(tb_ptr, a, msg_area);
+	memset(addr, 0, sizeof(*addr));
+	memcpy(addr->value, msg, INFINIBAND_ALEN);
+	addr->media_id = TIPC_MEDIA_TYPE_IB;
+	addr->broadcast = !memcmp(msg, b->bcast_addr.value,
+				  INFINIBAND_ALEN);
 	return 0;
 }
 
+/* Convert discovery msg addr format to InfiniBand media addr format */
+static int tipc_ib_msg2addr(struct tipc_bearer *b,
+			    struct tipc_media_addr *addr,
+			    char *msg)
+{
+	return tipc_ib_raw2addr(b, addr, msg);
+}
+
 /* InfiniBand media registration info */
 struct tipc_media ib_media_info = {
 	.send_msg	= tipc_l2_send_msg,
@@ -79,6 +91,7 @@ struct tipc_media ib_media_info = {
 	.addr2str	= tipc_ib_addr2str,
 	.addr2msg	= tipc_ib_addr2msg,
 	.msg2addr	= tipc_ib_msg2addr,
+	.raw2addr	= tipc_ib_raw2addr,
 	.priority	= TIPC_DEF_LINK_PRI,
 	.tolerance	= TIPC_DEF_LINK_TOL,
 	.window		= TIPC_DEF_LINK_WIN,
@@ -86,4 +99,3 @@ struct tipc_media ib_media_info = {
 	.hwaddr_len	= INFINIBAND_ALEN,
 	.name		= "ib"
 };
-
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2140837fbab9..ad2c57f5868d 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -37,6 +37,7 @@
 #include "core.h"
 #include "link.h"
 #include "port.h"
+#include "socket.h"
 #include "name_distr.h"
 #include "discover.h"
 #include "config.h"
@@ -398,9 +399,8 @@ static void link_release_outqueue(struct tipc_link *l_ptr)
  */
 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 {
-	kfree_skb(l_ptr->reasm_head);
-	l_ptr->reasm_head = NULL;
-	l_ptr->reasm_tail = NULL;
+	kfree_skb(l_ptr->reasm_buf);
+	l_ptr->reasm_buf = NULL;
 }
 
 /**
@@ -1573,17 +1573,12 @@ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
 			}
 			msg = buf_msg(buf);
 		} else if (msg_user(msg) == MSG_FRAGMENTER) {
-			int rc;
-
 			l_ptr->stats.recv_fragments++;
-			rc = tipc_link_frag_rcv(&l_ptr->reasm_head,
-						&l_ptr->reasm_tail,
-						&buf);
-			if (rc == LINK_REASM_COMPLETE) {
+			if (tipc_buf_append(&l_ptr->reasm_buf, &buf)) {
 				l_ptr->stats.recv_fragmented++;
 				msg = buf_msg(buf);
 			} else {
-				if (rc == LINK_REASM_ERROR)
+				if (!l_ptr->reasm_buf)
 					tipc_link_reset(l_ptr);
 				tipc_node_unlock(n_ptr);
 				continue;
@@ -1596,7 +1591,7 @@ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
 		case TIPC_HIGH_IMPORTANCE:
 		case TIPC_CRITICAL_IMPORTANCE:
 			tipc_node_unlock(n_ptr);
-			tipc_port_rcv(buf);
+			tipc_sk_rcv(buf);
 			continue;
 		case MSG_BUNDLER:
 			l_ptr->stats.recv_bundles++;
@@ -1831,9 +1826,6 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
 	if (l_ptr->exp_msg_count)
 		goto exit;
 
-	/* record unnumbered packet arrival (force mismatch on next timeout) */
-	l_ptr->checkpoint--;
-
 	if (l_ptr->net_plane != msg_net_plane(msg))
 		if (tipc_own_addr > msg_prevnode(msg))
 			l_ptr->net_plane = msg_net_plane(msg);
@@ -1909,6 +1901,10 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
 			tipc_link_reset(l_ptr); /* Enforce change to take effect */
 			break;
 		}
+
+		/* Record reception; force mismatch at next timeout: */
+		l_ptr->checkpoint--;
+
 		link_state_event(l_ptr, TRAFFIC_MSG_EVT);
 		l_ptr->stats.recv_states++;
 		if (link_reset_unknown(l_ptr))
@@ -2168,9 +2164,7 @@ static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
 		}
 		if (msg_user(msg) == MSG_FRAGMENTER) {
 			l_ptr->stats.recv_fragments++;
-			tipc_link_frag_rcv(&l_ptr->reasm_head,
-					   &l_ptr->reasm_tail,
-					   &buf);
+			tipc_buf_append(&l_ptr->reasm_buf, &buf);
 		}
 	}
 exit:
@@ -2308,53 +2302,6 @@ static int tipc_link_frag_xmit(struct tipc_link *l_ptr, struct sk_buff *buf)
 	return dsz;
 }
 
-/* tipc_link_frag_rcv(): Called with node lock on. Returns
- * the reassembled buffer if message is complete.
- */
-int tipc_link_frag_rcv(struct sk_buff **head, struct sk_buff **tail,
-		       struct sk_buff **fbuf)
-{
-	struct sk_buff *frag = *fbuf;
-	struct tipc_msg *msg = buf_msg(frag);
-	u32 fragid = msg_type(msg);
-	bool headstolen;
-	int delta;
-
-	skb_pull(frag, msg_hdr_sz(msg));
-	if (fragid == FIRST_FRAGMENT) {
-		if (*head || skb_unclone(frag, GFP_ATOMIC))
-			goto out_free;
-		*head = frag;
-		skb_frag_list_init(*head);
-		*fbuf = NULL;
-		return 0;
-	} else if (*head &&
-		   skb_try_coalesce(*head, frag, &headstolen, &delta)) {
-		kfree_skb_partial(frag, headstolen);
-	} else {
-		if (!*head)
-			goto out_free;
-		if (!skb_has_frag_list(*head))
-			skb_shinfo(*head)->frag_list = frag;
-		else
-			(*tail)->next = frag;
-		*tail = frag;
-		(*head)->truesize += frag->truesize;
-	}
-	if (fragid == LAST_FRAGMENT) {
-		*fbuf = *head;
-		*tail = *head = NULL;
-		return LINK_REASM_COMPLETE;
-	}
-	*fbuf = NULL;
-	return 0;
-out_free:
-	pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
-	kfree_skb(*fbuf);
-	*fbuf = NULL;
-	return LINK_REASM_ERROR;
-}
-
 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
 {
 	if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 7ba73fa6b81e..200d518b218e 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -40,11 +40,6 @@
 #include "msg.h"
 #include "node.h"
 
-/* Link reassembly status codes
- */
-#define LINK_REASM_ERROR	-1
-#define LINK_REASM_COMPLETE	1
-
 /* Out-of-range value for link sequence numbers
  */
 #define INVALID_LINK_SEQ 0x10000
@@ -140,8 +135,7 @@ struct tipc_stats {
  * @next_out: ptr to first unsent outbound message in queue
  * @waiting_ports: linked list of ports waiting for link congestion to abate
  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
- * @reasm_head: list head of partially reassembled inbound message fragments
- * @reasm_tail: last fragment received
+ * @reasm_buf: head of partially reassembled inbound message fragments
  * @stats: collects statistics regarding link activity
  */
 struct tipc_link {
@@ -204,8 +198,7 @@ struct tipc_link {
 
 	/* Fragmentation/reassembly */
 	u32 long_msg_seq_no;
-	struct sk_buff *reasm_head;
-	struct sk_buff *reasm_tail;
+	struct sk_buff *reasm_buf;
 
 	/* Statistics */
 	struct tipc_stats stats;
@@ -242,9 +235,6 @@ int tipc_link_iovec_xmit_fast(struct tipc_port *sender,
 			      struct iovec const *msg_sect,
 			      unsigned int len, u32 destnode);
 void tipc_link_bundle_rcv(struct sk_buff *buf);
-int tipc_link_frag_rcv(struct sk_buff **reasm_head,
-		       struct sk_buff **reasm_tail,
-		       struct sk_buff **fbuf);
 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 			  u32 gap, u32 tolerance, u32 priority, u32 acked_mtu);
 void tipc_link_push_queue(struct tipc_link *l_ptr);
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index e525f8ce1dee..8be6e94a1ca9 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/msg.c: TIPC message header routines
  *
- * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2000-2006, 2014, Ericsson AB
  * Copyright (c) 2005, 2010-2011, Wind River Systems
  * All rights reserved.
  *
@@ -99,3 +99,56 @@ int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
 	}
 	return dsz;
 }
+
+/* tipc_buf_append(): Append a buffer to the fragment list of another buffer
+ * Let first buffer become head buffer
+ * Returns 1 and sets *buf to headbuf if chain is complete, otherwise 0
+ * Leaves headbuf pointer at NULL if failure
+ */
+int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
+{
+	struct sk_buff *head = *headbuf;
+	struct sk_buff *frag = *buf;
+	struct sk_buff *tail;
+	struct tipc_msg *msg = buf_msg(frag);
+	u32 fragid = msg_type(msg);
+	bool headstolen;
+	int delta;
+
+	skb_pull(frag, msg_hdr_sz(msg));
+
+	if (fragid == FIRST_FRAGMENT) {
+		if (head || skb_unclone(frag, GFP_ATOMIC))
+			goto out_free;
+		head = *headbuf = frag;
+		skb_frag_list_init(head);
+		return 0;
+	}
+	if (!head)
+		goto out_free;
+	tail = TIPC_SKB_CB(head)->tail;
+	if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
+		kfree_skb_partial(frag, headstolen);
+	} else {
+		if (!skb_has_frag_list(head))
+			skb_shinfo(head)->frag_list = frag;
+		else
+			tail->next = frag;
+		head->truesize += frag->truesize;
+		head->data_len += frag->len;
+		head->len += frag->len;
+		TIPC_SKB_CB(head)->tail = frag;
+	}
+	if (fragid == LAST_FRAGMENT) {
+		*buf = head;
+		TIPC_SKB_CB(head)->tail = NULL;
+		*headbuf = NULL;
+		return 1;
+	}
+	*buf = NULL;
+	return 0;
+out_free:
+	pr_warn_ratelimited("Unable to build fragment list\n");
+	kfree_skb(*buf);
+	return 0;
+}
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 76d1269b9443..503511903d1d 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -1,7 +1,7 @@
 /*
  * net/tipc/msg.h: Include file for TIPC message header routines
  *
- * Copyright (c) 2000-2007, Ericsson AB
+ * Copyright (c) 2000-2007, 2014, Ericsson AB
  * Copyright (c) 2005-2008, 2010-2011, Wind River Systems
  * All rights reserved.
  *
@@ -711,4 +711,7 @@ void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
 		   u32 destnode);
 int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
 		   unsigned int len, int max_size, struct sk_buff **buf);
+
+int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf);
+
 #endif
diff --git a/net/tipc/net.c b/net/tipc/net.c
index f8fc95d58c0d..f64375e7f99f 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -39,6 +39,7 @@
 #include "name_distr.h"
 #include "subscr.h"
 #include "port.h"
+#include "socket.h"
 #include "node.h"
 #include "config.h"
 
@@ -141,7 +142,7 @@ void tipc_net_route_msg(struct sk_buff *buf)
 			if (msg_mcast(msg))
 				tipc_port_mcast_rcv(buf, NULL);
 			else if (msg_destport(msg))
-				tipc_port_rcv(buf);
+				tipc_sk_rcv(buf);
 			else
 				net_route_named_msg(buf);
 			return;
diff --git a/net/tipc/node.c b/net/tipc/node.c
index facd5611e785..5b44c3041be4 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -286,10 +286,9 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 		kfree_skb_list(n_ptr->bclink.deferred_head);
 		n_ptr->bclink.deferred_size = 0;
 
-		if (n_ptr->bclink.reasm_head) {
-			kfree_skb(n_ptr->bclink.reasm_head);
-			n_ptr->bclink.reasm_head = NULL;
-			n_ptr->bclink.reasm_tail = NULL;
+		if (n_ptr->bclink.reasm_buf) {
+			kfree_skb(n_ptr->bclink.reasm_buf);
+			n_ptr->bclink.reasm_buf = NULL;
 		}
 
 		tipc_bclink_remove_node(n_ptr->addr);
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 5454edf994c3..9087063793f2 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -69,8 +69,7 @@ enum {
  * @deferred_size: number of OOS b'cast messages in deferred queue
  * @deferred_head: oldest OOS b'cast message received from node
  * @deferred_tail: newest OOS b'cast message received from node
- * @reasm_head: broadcast reassembly queue head from node
- * @reasm_tail: last broadcast fragment received from node
+ * @reasm_buf: broadcast reassembly queue head from node
  * @recv_permitted: true if node is allowed to receive b'cast messages
  */
 struct tipc_node_bclink {
@@ -81,8 +80,7 @@ struct tipc_node_bclink {
 	u32 deferred_size;
 	struct sk_buff *deferred_head;
 	struct sk_buff *deferred_tail;
-	struct sk_buff *reasm_head;
-	struct sk_buff *reasm_tail;
+	struct sk_buff *reasm_buf;
 	bool recv_permitted;
 };
 
diff --git a/net/tipc/port.c b/net/tipc/port.c
index 5c14c7801ee6..5fd7acce01ea 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -165,7 +165,7 @@ void tipc_port_mcast_rcv(struct sk_buff *buf, struct tipc_port_list *dp)
 		msg_set_destnode(msg, tipc_own_addr);
 		if (dp->count == 1) {
 			msg_set_destport(msg, dp->ports[0]);
-			tipc_port_rcv(buf);
+			tipc_sk_rcv(buf);
 			tipc_port_list_free(dp);
 			return;
 		}
@@ -180,7 +180,7 @@ void tipc_port_mcast_rcv(struct sk_buff *buf, struct tipc_port_list *dp)
 			if ((index == 0) && (cnt != 0))
 				item = item->next;
 			msg_set_destport(buf_msg(b), item->ports[index]);
-			tipc_port_rcv(b);
+			tipc_sk_rcv(b);
 		}
 	}
 exit:
@@ -343,7 +343,7 @@ int tipc_reject_msg(struct sk_buff *buf, u32 err)
 	/* send returned message & dispose of rejected message */
 	src_node = msg_prevnode(msg);
 	if (in_own_node(src_node))
-		tipc_port_rcv(rbuf);
+		tipc_sk_rcv(rbuf);
 	else
 		tipc_link_xmit(rbuf, src_node, msg_link_selector(rmsg));
 exit:
@@ -754,37 +754,6 @@ int tipc_port_shutdown(u32 ref)
 	return tipc_port_disconnect(ref);
 }
 
-/**
- * tipc_port_rcv - receive message from lower layer and deliver to port user
- */
-int tipc_port_rcv(struct sk_buff *buf)
-{
-	struct tipc_port *p_ptr;
-	struct tipc_msg *msg = buf_msg(buf);
-	u32 destport = msg_destport(msg);
-	u32 dsz = msg_data_sz(msg);
-	u32 err;
-
-	/* forward unresolved named message */
-	if (unlikely(!destport)) {
-		tipc_net_route_msg(buf);
-		return dsz;
-	}
-
-	/* validate destination & pass to port, otherwise reject message */
-	p_ptr = tipc_port_lock(destport);
-	if (likely(p_ptr)) {
-		err = tipc_sk_rcv(&tipc_port_to_sock(p_ptr)->sk, buf);
-		tipc_port_unlock(p_ptr);
-		if (likely(!err))
-			return dsz;
-	} else {
-		err = TIPC_ERR_NO_PORT;
-	}
-
-	return tipc_reject_msg(buf, err);
-}
-
 /*
  *  tipc_port_iovec_rcv: Concatenate and deliver sectioned
  *                       message for this node.
@@ -798,7 +767,7 @@ static int tipc_port_iovec_rcv(struct tipc_port *sender,
 
 	res = tipc_msg_build(&sender->phdr, msg_sect, len, MAX_MSG_SIZE, &buf);
 	if (likely(buf))
-		tipc_port_rcv(buf);
+		tipc_sk_rcv(buf);
 	return res;
 }
 
diff --git a/net/tipc/port.h b/net/tipc/port.h
index a00397393bd1..cf4ca5b1d9a4 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -42,9 +42,10 @@
 #include "msg.h"
 #include "node_subscr.h"
 
-#define TIPC_FLOW_CONTROL_WIN 512
-#define CONN_OVERLOAD_LIMIT	((TIPC_FLOW_CONTROL_WIN * 2 + 1) * \
-				SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
+#define TIPC_CONNACK_INTV         256
+#define TIPC_FLOWCTRL_WIN        (TIPC_CONNACK_INTV * 2)
+#define TIPC_CONN_OVERLOAD_LIMIT ((TIPC_FLOWCTRL_WIN * 2 + 1) * \
+				  SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
 
 /**
  * struct tipc_port - TIPC port structure
@@ -134,7 +135,6 @@ int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg);
 /*
  * TIPC messaging routines
  */
-int tipc_port_rcv(struct sk_buff *buf);
 
 int tipc_send(struct tipc_port *port,
 	      struct iovec const *msg_sect,
@@ -187,7 +187,7 @@ static inline void tipc_port_unlock(struct tipc_port *p_ptr)
 
 static inline int tipc_port_congested(struct tipc_port *p_ptr)
 {
-	return (p_ptr->sent - p_ptr->acked) >= (TIPC_FLOW_CONTROL_WIN * 2);
+	return ((p_ptr->sent - p_ptr->acked) >= TIPC_FLOWCTRL_WIN);
 }
 
 
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 3f9912f87d0d..ac08966f2858 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1,5 +1,5 @@
 /*
- * net/tipc/socket.c: TIPC socket API
+* net/tipc/socket.c: TIPC socket API
  *
  * Copyright (c) 2001-2007, 2012-2014, Ericsson AB
  * Copyright (c) 2004-2008, 2010-2013, Wind River Systems
@@ -45,7 +45,7 @@
 
 #define CONN_TIMEOUT_DEFAULT	8000	/* default connect timeout = 8s */
 
-static int backlog_rcv(struct sock *sk, struct sk_buff *skb);
+static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 static void tipc_data_ready(struct sock *sk);
 static void tipc_write_space(struct sock *sk);
 static int tipc_release(struct socket *sock);
@@ -196,11 +196,12 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 	sock->state = state;
 
 	sock_init_data(sock, sk);
-	sk->sk_backlog_rcv = backlog_rcv;
+	sk->sk_backlog_rcv = tipc_backlog_rcv;
 	sk->sk_rcvbuf = sysctl_tipc_rmem[1];
 	sk->sk_data_ready = tipc_data_ready;
 	sk->sk_write_space = tipc_write_space;
-	tipc_sk(sk)->conn_timeout = CONN_TIMEOUT_DEFAULT;
+	tsk->conn_timeout = CONN_TIMEOUT_DEFAULT;
+	atomic_set(&tsk->dupl_rcvcnt, 0);
 	tipc_port_unlock(port);
 
 	if (sock->state == SS_READY) {
@@ -1101,7 +1102,7 @@ restart:
 	/* Consume received message (optional) */
 	if (likely(!(flags & MSG_PEEK))) {
 		if ((sock->state != SS_READY) &&
-		    (++port->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
+		    (++port->conn_unacked >= TIPC_CONNACK_INTV))
 			tipc_acknowledge(port->ref, port->conn_unacked);
 		advance_rx_queue(sk);
 	}
@@ -1210,7 +1211,7 @@ restart:
 
 	/* Consume received message (optional) */
 	if (likely(!(flags & MSG_PEEK))) {
-		if (unlikely(++port->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
+		if (unlikely(++port->conn_unacked >= TIPC_CONNACK_INTV))
 			tipc_acknowledge(port->ref, port->conn_unacked);
 		advance_rx_queue(sk);
 	}
@@ -1416,7 +1417,7 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
 }
 
 /**
- * backlog_rcv - handle incoming message from backlog queue
+ * tipc_backlog_rcv - handle incoming message from backlog queue
  * @sk: socket
  * @buf: message
  *
@@ -1424,47 +1425,73 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
  *
  * Returns 0
  */
-static int backlog_rcv(struct sock *sk, struct sk_buff *buf)
+static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *buf)
 {
 	u32 res;
+	struct tipc_sock *tsk = tipc_sk(sk);
 
 	res = filter_rcv(sk, buf);
-	if (res)
+	if (unlikely(res))
 		tipc_reject_msg(buf, res);
+
+	if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT)
+		atomic_add(buf->truesize, &tsk->dupl_rcvcnt);
+
 	return 0;
 }
 
 /**
  * tipc_sk_rcv - handle incoming message
- * @sk:  socket receiving message
- * @buf: message
- *
- * Called with port lock already taken.
- *
- * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
+ * @buf: buffer containing arriving message
+ * Consumes buffer
+ * Returns 0 if success, or errno: -EHOSTUNREACH
  */
-u32 tipc_sk_rcv(struct sock *sk, struct sk_buff *buf)
+int tipc_sk_rcv(struct sk_buff *buf)
 {
-	u32 res;
+	struct tipc_sock *tsk;
+	struct tipc_port *port;
+	struct sock *sk;
+	u32 dport = msg_destport(buf_msg(buf));
+	int err = TIPC_OK;
+	uint limit;
 
-	/*
-	 * Process message if socket is unlocked; otherwise add to backlog queue
-	 *
-	 * This code is based on sk_receive_skb(), but must be distinct from it
-	 * since a TIPC-specific filter/reject mechanism is utilized
-	 */
+	/* Forward unresolved named message */
+	if (unlikely(!dport)) {
+		tipc_net_route_msg(buf);
+		return 0;
+	}
+
+	/* Validate destination */
+	port = tipc_port_lock(dport);
+	if (unlikely(!port)) {
+		err = TIPC_ERR_NO_PORT;
+		goto exit;
+	}
+
+	tsk = tipc_port_to_sock(port);
+	sk = &tsk->sk;
+
+	/* Queue message */
 	bh_lock_sock(sk);
+
 	if (!sock_owned_by_user(sk)) {
-		res = filter_rcv(sk, buf);
+		err = filter_rcv(sk, buf);
 	} else {
-		if (sk_add_backlog(sk, buf, rcvbuf_limit(sk, buf)))
-			res = TIPC_ERR_OVERLOAD;
-		else
-			res = TIPC_OK;
+		if (sk->sk_backlog.len == 0)
+			atomic_set(&tsk->dupl_rcvcnt, 0);
+		limit = rcvbuf_limit(sk, buf) + atomic_read(&tsk->dupl_rcvcnt);
+		if (sk_add_backlog(sk, buf, limit))
+			err = TIPC_ERR_OVERLOAD;
 	}
+
 	bh_unlock_sock(sk);
+	tipc_port_unlock(port);
 
-	return res;
+	if (likely(!err))
+		return 0;
+exit:
+	tipc_reject_msg(buf, err);
+	return -EHOSTUNREACH;
 }
 
 static int tipc_wait_for_connect(struct socket *sock, long *timeo_p)
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index 74e5c7f195a6..3afcd2a70b31 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -44,12 +44,14 @@
  * @port: port - interacts with 'sk' and with the rest of the TIPC stack
  * @peer_name: the peer of the connection, if any
  * @conn_timeout: the time we can wait for an unresponded setup request
+ * @dupl_rcvcnt: number of bytes counted twice, in both backlog and rcv queue
  */
 
 struct tipc_sock {
 	struct sock sk;
 	struct tipc_port port;
 	unsigned int conn_timeout;
+	atomic_t dupl_rcvcnt;
 };
 
 static inline struct tipc_sock *tipc_sk(const struct sock *sk)
@@ -67,6 +69,6 @@ static inline void tipc_sock_wakeup(struct tipc_sock *tsk)
 	tsk->sk.sk_write_space(&tsk->sk);
 }
 
-u32 tipc_sk_rcv(struct sock *sk, struct sk_buff *buf);
+int tipc_sk_rcv(struct sk_buff *buf);
 
 #endif