diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2a9f44a..4bab139 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -92,7 +92,8 @@
 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
 static int  link_send_sections_long(struct tipc_port *sender,
 				    struct iovec const *msg_sect,
-				    u32 num_sect, u32 destnode);
+				    u32 num_sect, unsigned int total_len,
+				    u32 destnode);
 static void link_check_defragm_bufs(struct link *l_ptr);
 static void link_state_event(struct link *l_ptr, u32 event);
 static void link_reset_statistics(struct link *l_ptr);
@@ -1043,6 +1044,7 @@
 int tipc_link_send_sections_fast(struct tipc_port *sender,
 				 struct iovec const *msg_sect,
 				 const u32 num_sect,
+				 unsigned int total_len,
 				 u32 destaddr)
 {
 	struct tipc_msg *hdr = &sender->phdr;
@@ -1058,8 +1060,8 @@
 	 * (Must not hold any locks while building message.)
 	 */
 
-	res = tipc_msg_build(hdr, msg_sect, num_sect, sender->max_pkt,
-			!sender->user_port, &buf);
+	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
+			     sender->max_pkt, !sender->user_port, &buf);
 
 	read_lock_bh(&tipc_net_lock);
 	node = tipc_node_find(destaddr);
@@ -1104,7 +1106,8 @@
 				goto again;
 
 			return link_send_sections_long(sender, msg_sect,
-						       num_sect, destaddr);
+						       num_sect, total_len,
+						       destaddr);
 		}
 		tipc_node_unlock(node);
 	}
@@ -1116,7 +1119,7 @@
 		return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
 	if (res >= 0)
 		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
-						 TIPC_ERR_NO_NODE);
+						 total_len, TIPC_ERR_NO_NODE);
 	return res;
 }
 
@@ -1137,12 +1140,13 @@
 static int link_send_sections_long(struct tipc_port *sender,
 				   struct iovec const *msg_sect,
 				   u32 num_sect,
+				   unsigned int total_len,
 				   u32 destaddr)
 {
 	struct link *l_ptr;
 	struct tipc_node *node;
 	struct tipc_msg *hdr = &sender->phdr;
-	u32 dsz = msg_data_sz(hdr);
+	u32 dsz = total_len;
 	u32 max_pkt, fragm_sz, rest;
 	struct tipc_msg fragm_hdr;
 	struct sk_buff *buf, *buf_chain, *prev;
@@ -1269,7 +1273,7 @@
 			buf_discard(buf_chain);
 		}
 		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
-						 TIPC_ERR_NO_NODE);
+						 total_len, TIPC_ERR_NO_NODE);
 	}
 
 	/* Append whole chain to send queue: */
diff --git a/net/tipc/link.h b/net/tipc/link.h
index e6a30db..74fbeca 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -228,6 +228,7 @@
 int tipc_link_send_sections_fast(struct tipc_port *sender,
 				 struct iovec const *msg_sect,
 				 const u32 num_sect,
+				 unsigned int total_len,
 				 u32 destnode);
 void tipc_link_recv_bundle(struct sk_buff *buf);
 int  tipc_link_recv_fragment(struct sk_buff **pending,
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 6d92d17..03e57bf 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -68,20 +68,6 @@
 }
 
 /**
- * tipc_msg_calc_data_size - determine total data size for message
- */
-
-int tipc_msg_calc_data_size(struct iovec const *msg_sect, u32 num_sect)
-{
-	int dsz = 0;
-	int i;
-
-	for (i = 0; i < num_sect; i++)
-		dsz += msg_sect[i].iov_len;
-	return dsz;
-}
-
-/**
  * tipc_msg_build - create message using specified header and data
  *
  * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
@@ -89,18 +75,13 @@
  * Returns message data size or errno
  */
 
-int tipc_msg_build(struct tipc_msg *hdr,
-			    struct iovec const *msg_sect, u32 num_sect,
+int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
+		   u32 num_sect, unsigned int total_len,
 			    int max_size, int usrmem, struct sk_buff **buf)
 {
 	int dsz, sz, hsz, pos, res, cnt;
 
-	dsz = tipc_msg_calc_data_size(msg_sect, num_sect);
-	if (unlikely(dsz > TIPC_MAX_USER_MSG_SIZE)) {
-		*buf = NULL;
-		return -EINVAL;
-	}
-
+	dsz = total_len;
 	pos = hsz = msg_hdr_sz(hdr);
 	sz = hsz + dsz;
 	msg_set_size(hdr, sz);
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 005b318..8452454 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -750,9 +750,8 @@
 u32 tipc_msg_tot_importance(struct tipc_msg *m);
 void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type,
 			    u32 hsize, u32 destnode);
-int tipc_msg_calc_data_size(struct iovec const *msg_sect, u32 num_sect);
-int tipc_msg_build(struct tipc_msg *hdr,
-			    struct iovec const *msg_sect, u32 num_sect,
+int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
+		   u32 num_sect, unsigned int total_len,
 			    int max_size, int usrmem, struct sk_buff **buf);
 
 static inline void msg_set_media_addr(struct tipc_msg *m, struct tipc_media_addr *a)
diff --git a/net/tipc/port.c b/net/tipc/port.c
index 9f2ff12..c68dc95 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -74,7 +74,8 @@
  */
 
 int tipc_multicast(u32 ref, struct tipc_name_seq const *seq,
-		   u32 num_sect, struct iovec const *msg_sect)
+		   u32 num_sect, struct iovec const *msg_sect,
+		   unsigned int total_len)
 {
 	struct tipc_msg *hdr;
 	struct sk_buff *buf;
@@ -98,7 +99,7 @@
 	msg_set_namelower(hdr, seq->lower);
 	msg_set_nameupper(hdr, seq->upper);
 	msg_set_hdr_sz(hdr, MCAST_H_SIZE);
-	res = tipc_msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
+	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len, MAX_MSG_SIZE,
 			!oport->user_port, &buf);
 	if (unlikely(!buf))
 		return res;
@@ -418,12 +419,12 @@
 
 int tipc_port_reject_sections(struct tipc_port *p_ptr, struct tipc_msg *hdr,
 			      struct iovec const *msg_sect, u32 num_sect,
-			      int err)
+			      unsigned int total_len, int err)
 {
 	struct sk_buff *buf;
 	int res;
 
-	res = tipc_msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
+	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len, MAX_MSG_SIZE,
 			!p_ptr->user_port, &buf);
 	if (!buf)
 		return res;
@@ -1163,12 +1164,13 @@
  */
 
 static int tipc_port_recv_sections(struct tipc_port *sender, unsigned int num_sect,
-				   struct iovec const *msg_sect)
+				   struct iovec const *msg_sect,
+				   unsigned int total_len)
 {
 	struct sk_buff *buf;
 	int res;
 
-	res = tipc_msg_build(&sender->phdr, msg_sect, num_sect,
+	res = tipc_msg_build(&sender->phdr, msg_sect, num_sect, total_len,
 			MAX_MSG_SIZE, !sender->user_port, &buf);
 	if (likely(buf))
 		tipc_port_recv_msg(buf);
@@ -1179,7 +1181,8 @@
  * tipc_send - send message sections on connection
  */
 
-int tipc_send(u32 ref, unsigned int num_sect, struct iovec const *msg_sect)
+int tipc_send(u32 ref, unsigned int num_sect, struct iovec const *msg_sect,
+	      unsigned int total_len)
 {
 	struct tipc_port *p_ptr;
 	u32 destnode;
@@ -1194,9 +1197,10 @@
 		destnode = port_peernode(p_ptr);
 		if (likely(destnode != tipc_own_addr))
 			res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
-							   destnode);
+							   total_len, destnode);
 		else
-			res = tipc_port_recv_sections(p_ptr, num_sect, msg_sect);
+			res = tipc_port_recv_sections(p_ptr, num_sect, msg_sect,
+						      total_len);
 
 		if (likely(res != -ELINKCONG)) {
 			p_ptr->congested = 0;
@@ -1207,8 +1211,7 @@
 	}
 	if (port_unreliable(p_ptr)) {
 		p_ptr->congested = 0;
-		/* Just calculate msg length and return */
-		return tipc_msg_calc_data_size(msg_sect, num_sect);
+		return total_len;
 	}
 	return -ELINKCONG;
 }
@@ -1218,7 +1221,8 @@
  */
 
 int tipc_send2name(u32 ref, struct tipc_name const *name, unsigned int domain,
-	   unsigned int num_sect, struct iovec const *msg_sect)
+		   unsigned int num_sect, struct iovec const *msg_sect,
+		   unsigned int total_len)
 {
 	struct tipc_port *p_ptr;
 	struct tipc_msg *msg;
@@ -1245,23 +1249,23 @@
 	if (likely(destport)) {
 		if (likely(destnode == tipc_own_addr))
 			res = tipc_port_recv_sections(p_ptr, num_sect,
-						      msg_sect);
+						      msg_sect, total_len);
 		else
 			res = tipc_link_send_sections_fast(p_ptr, msg_sect,
-							   num_sect, destnode);
+							   num_sect, total_len,
+							   destnode);
 		if (likely(res != -ELINKCONG)) {
 			if (res > 0)
 				p_ptr->sent++;
 			return res;
 		}
 		if (port_unreliable(p_ptr)) {
-			/* Just calculate msg length and return */
-			return tipc_msg_calc_data_size(msg_sect, num_sect);
+			return total_len;
 		}
 		return -ELINKCONG;
 	}
 	return tipc_port_reject_sections(p_ptr, msg, msg_sect, num_sect,
-					 TIPC_ERR_NO_NAME);
+					 total_len, TIPC_ERR_NO_NAME);
 }
 
 /**
@@ -1269,7 +1273,8 @@
  */
 
 int tipc_send2port(u32 ref, struct tipc_portid const *dest,
-	   unsigned int num_sect, struct iovec const *msg_sect)
+		   unsigned int num_sect, struct iovec const *msg_sect,
+		   unsigned int total_len)
 {
 	struct tipc_port *p_ptr;
 	struct tipc_msg *msg;
@@ -1289,18 +1294,18 @@
 	msg_set_hdr_sz(msg, DIR_MSG_H_SIZE);
 
 	if (dest->node == tipc_own_addr)
-		res =  tipc_port_recv_sections(p_ptr, num_sect, msg_sect);
+		res =  tipc_port_recv_sections(p_ptr, num_sect, msg_sect,
+					       total_len);
 	else
 		res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
-						   dest->node);
+						   total_len, dest->node);
 	if (likely(res != -ELINKCONG)) {
 		if (res > 0)
 			p_ptr->sent++;
 		return res;
 	}
 	if (port_unreliable(p_ptr)) {
-		/* Just calculate msg length and return */
-		return tipc_msg_calc_data_size(msg_sect, num_sect);
+		return total_len;
 	}
 	return -ELINKCONG;
 }
diff --git a/net/tipc/port.h b/net/tipc/port.h
index 87b9424..b9aa341 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -205,23 +205,27 @@
 /*
  * TIPC messaging routines
  */
-int tipc_send(u32 portref, unsigned int num_sect, struct iovec const *msg_sect);
+int tipc_send(u32 portref, unsigned int num_sect, struct iovec const *msg_sect,
+	      unsigned int total_len);
 
 int tipc_send2name(u32 portref, struct tipc_name const *name, u32 domain,
-		unsigned int num_sect, struct iovec const *msg_sect);
+		   unsigned int num_sect, struct iovec const *msg_sect,
+		   unsigned int total_len);
 
 int tipc_send2port(u32 portref, struct tipc_portid const *dest,
-		unsigned int num_sect, struct iovec const *msg_sect);
+		   unsigned int num_sect, struct iovec const *msg_sect,
+		   unsigned int total_len);
 
 int tipc_send_buf2port(u32 portref, struct tipc_portid const *dest,
 		struct sk_buff *buf, unsigned int dsz);
 
 int tipc_multicast(u32 portref, struct tipc_name_seq const *seq,
-		unsigned int section_count, struct iovec const *msg);
+		   unsigned int section_count, struct iovec const *msg,
+		   unsigned int total_len);
 
 int tipc_port_reject_sections(struct tipc_port *p_ptr, struct tipc_msg *hdr,
 			      struct iovec const *msg_sect, u32 num_sect,
-			      int err);
+			      unsigned int total_len, int err);
 struct sk_buff *tipc_port_get_ports(void);
 void tipc_port_recv_proto_msg(struct sk_buff *buf);
 void tipc_port_recv_mcast(struct sk_buff *buf, struct port_list *dp);
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index e1c7917..3388373 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -576,12 +576,14 @@
 					     &dest->addr.name.name,
 					     dest->addr.name.domain,
 					     m->msg_iovlen,
-					     m->msg_iov);
+					     m->msg_iov,
+					     total_len);
 		} else if (dest->addrtype == TIPC_ADDR_ID) {
 			res = tipc_send2port(tport->ref,
 					     &dest->addr.id,
 					     m->msg_iovlen,
-					     m->msg_iov);
+					     m->msg_iov,
+					     total_len);
 		} else if (dest->addrtype == TIPC_ADDR_MCAST) {
 			if (needs_conn) {
 				res = -EOPNOTSUPP;
@@ -593,7 +595,8 @@
 			res = tipc_multicast(tport->ref,
 					     &dest->addr.nameseq,
 					     m->msg_iovlen,
-					     m->msg_iov);
+					     m->msg_iov,
+					     total_len);
 		}
 		if (likely(res != -ELINKCONG)) {
 			if (needs_conn && (res >= 0))
@@ -659,7 +662,8 @@
 			break;
 		}
 
-		res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov);
+		res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov,
+				total_len);
 		if (likely(res != -ELINKCONG))
 			break;
 		if (m->msg_flags & MSG_DONTWAIT) {
@@ -766,7 +770,7 @@
 				bytes_to_send = curr_left;
 			my_iov.iov_base = curr_start;
 			my_iov.iov_len = bytes_to_send;
-			res = send_packet(NULL, sock, &my_msg, 0);
+			res = send_packet(NULL, sock, &my_msg, bytes_to_send);
 			if (res < 0) {
 				if (bytes_sent)
 					res = bytes_sent;
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index aae9eae..6cf7268 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -109,7 +109,7 @@
 	sub->evt.found_upper = htohl(found_upper, sub->swap);
 	sub->evt.port.ref = htohl(port_ref, sub->swap);
 	sub->evt.port.node = htohl(node, sub->swap);
-	tipc_send(sub->server_ref, 1, &msg_sect);
+	tipc_send(sub->server_ref, 1, &msg_sect, msg_sect.iov_len);
 }
 
 /**
@@ -521,7 +521,7 @@
 
 	/* Send an ACK- to complete connection handshaking */
 
-	tipc_send(server_port_ref, 0, NULL);
+	tipc_send(server_port_ref, 0, NULL, 0);
 
 	/* Handle optional subscription request */