1 files changed, 323 insertions, 170 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 69cd9bf..0cc3d90 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -75,6 +75,20 @@ static const char *link_unk_evt = "Unknown link event ";
  */
 #define START_CHANGEOVER 100000u
 
+/**
+ * struct tipc_link_name - deconstructed link name
+ * @addr_local: network address of node at this end
+ * @if_local: name of interface at this end
+ * @addr_peer: network address of node at far end
+ * @if_peer: name of interface at far end
+ */
+struct tipc_link_name {
+	u32 addr_local;
+	char if_local[TIPC_MAX_IF_NAME];
+	u32 addr_peer;
+	char if_peer[TIPC_MAX_IF_NAME];
+};
+
 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
 				       struct sk_buff *buf);
 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
@@ -83,7 +97,8 @@ static int  link_recv_changeover_msg(struct tipc_link **l_ptr,
 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
 static int  link_send_sections_long(struct tipc_port *sender,
 				    struct iovec const *msg_sect,
-				    unsigned int len, u32 destnode);
+				    u32 num_sect, unsigned int total_len,
+				    u32 destnode);
 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 static void link_reset_statistics(struct tipc_link *l_ptr);
 static void link_print(struct tipc_link *l_ptr, const char *str);
@@ -146,6 +161,72 @@ int tipc_link_is_active(struct tipc_link *l_ptr)
 }
 
 /**
+ * link_name_validate - validate & (optionally) deconstruct tipc_link name
+ * @name: ptr to link name string
+ * @name_parts: ptr to area for link name components (or NULL if not needed)
+ *
+ * Returns 1 if link name is valid, otherwise 0.
+ */
+static int link_name_validate(const char *name,
+				struct tipc_link_name *name_parts)
+{
+	char name_copy[TIPC_MAX_LINK_NAME];
+	char *addr_local;
+	char *if_local;
+	char *addr_peer;
+	char *if_peer;
+	char dummy;
+	u32 z_local, c_local, n_local;
+	u32 z_peer, c_peer, n_peer;
+	u32 if_local_len;
+	u32 if_peer_len;
+
+	/* copy link name & ensure length is OK */
+	name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
+	/* need above in case non-Posix strncpy() doesn't pad with nulls */
+	strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
+	if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
+		return 0;
+
+	/* ensure all component parts of link name are present */
+	addr_local = name_copy;
+	if_local = strchr(addr_local, ':');
+	if (if_local == NULL)
+		return 0;
+	*(if_local++) = 0;
+	addr_peer = strchr(if_local, '-');
+	if (addr_peer == NULL)
+		return 0;
+	*(addr_peer++) = 0;
+	if_local_len = addr_peer - if_local;
+	if_peer = strchr(addr_peer, ':');
+	if (if_peer == NULL)
+		return 0;
+	*(if_peer++) = 0;
+	if_peer_len = strlen(if_peer) + 1;
+
+	/* validate component parts of link name */
+	if ((sscanf(addr_local, "%u.%u.%u%c",
+		    &z_local, &c_local, &n_local, &dummy) != 3) ||
+	    (sscanf(addr_peer, "%u.%u.%u%c",
+		    &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
+	    (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
+	    (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
+	    (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
+	    (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME))
+		return 0;
+
+	/* return link name components, if necessary */
+	if (name_parts) {
+		name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
+		strcpy(name_parts->if_local, if_local);
+		name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
+		strcpy(name_parts->if_peer, if_peer);
+	}
+	return 1;
+}
+
+/**
  * link_timeout - handle expiration of link timer
  * @l_ptr: pointer to link
  *
@@ -404,9 +485,15 @@ 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;
+	struct sk_buff *buf = l_ptr->defragm_buf;
+	struct sk_buff *next;
+
+	while (buf) {
+		next = buf->next;
+		kfree_skb(buf);
+		buf = next;
+	}
+	l_ptr->defragm_buf = NULL;
 }
 
 /**
@@ -978,7 +1065,8 @@ static int link_send_buf_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
  */
 int tipc_link_send_sections_fast(struct tipc_port *sender,
 				 struct iovec const *msg_sect,
-				 unsigned int len, u32 destaddr)
+				 const u32 num_sect, unsigned int total_len,
+				 u32 destaddr)
 {
 	struct tipc_msg *hdr = &sender->phdr;
 	struct tipc_link *l_ptr;
@@ -992,7 +1080,8 @@ again:
 	 * Try building message using port's max_pkt hint.
 	 * (Must not hold any locks while building message.)
 	 */
-	res = tipc_msg_build(hdr, msg_sect, len, sender->max_pkt, &buf);
+	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
+			     sender->max_pkt, &buf);
 	/* Exit if build request was invalid */
 	if (unlikely(res < 0))
 		return res;
@@ -1032,7 +1121,8 @@ exit:
 			if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
 				goto again;
 
-			return link_send_sections_long(sender, msg_sect, len,
+			return link_send_sections_long(sender, msg_sect,
+						       num_sect, total_len,
 						       destaddr);
 		}
 		tipc_node_unlock(node);
@@ -1043,8 +1133,8 @@ exit:
 	if (buf)
 		return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
 	if (res >= 0)
-		return tipc_port_reject_sections(sender, hdr, msg_sect,
-						 len, TIPC_ERR_NO_NODE);
+		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
+						 total_len, TIPC_ERR_NO_NODE);
 	return res;
 }
 
@@ -1064,17 +1154,18 @@ exit:
  */
 static int link_send_sections_long(struct tipc_port *sender,
 				   struct iovec const *msg_sect,
-				   unsigned int len, u32 destaddr)
+				   u32 num_sect, unsigned int total_len,
+				   u32 destaddr)
 {
 	struct tipc_link *l_ptr;
 	struct tipc_node *node;
 	struct tipc_msg *hdr = &sender->phdr;
-	u32 dsz = len;
+	u32 dsz = total_len;
 	u32 max_pkt, fragm_sz, rest;
 	struct tipc_msg fragm_hdr;
 	struct sk_buff *buf, *buf_chain, *prev;
 	u32 fragm_crs, fragm_rest, hsz, sect_rest;
-	const unchar __user *sect_crs;
+	const unchar *sect_crs;
 	int curr_sect;
 	u32 fragm_no;
 	int res = 0;
@@ -1116,7 +1207,7 @@ again:
 
 		if (!sect_rest) {
 			sect_rest = msg_sect[++curr_sect].iov_len;
-			sect_crs = msg_sect[curr_sect].iov_base;
+			sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
 		}
 
 		if (sect_rest < fragm_rest)
@@ -1192,8 +1283,8 @@ reject:
 			buf = buf_chain->next;
 			kfree_skb(buf_chain);
 		}
-		return tipc_port_reject_sections(sender, hdr, msg_sect,
-						 len, TIPC_ERR_NO_NODE);
+		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
+						 total_len, TIPC_ERR_NO_NODE);
 	}
 
 	/* Append chain of fragments to send queue & send them */
@@ -1501,15 +1592,15 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
 		/* Ensure bearer is still enabled */
 		if (unlikely(!b_ptr->active))
-			goto discard;
+			goto cont;
 
 		/* Ensure message is well-formed */
 		if (unlikely(!link_recv_buf_validate(buf)))
-			goto discard;
+			goto cont;
 
 		/* Ensure message data is a single contiguous unit */
 		if (unlikely(skb_linearize(buf)))
-			goto discard;
+			goto cont;
 
 		/* Handle arrival of a non-unicast link message */
 		msg = buf_msg(buf);
@@ -1525,18 +1616,20 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 		/* Discard unicast link messages destined for another node */
 		if (unlikely(!msg_short(msg) &&
 			     (msg_destnode(msg) != tipc_own_addr)))
-			goto discard;
+			goto cont;
 
 		/* Locate neighboring node that sent message */
 		n_ptr = tipc_node_find(msg_prevnode(msg));
 		if (unlikely(!n_ptr))
-			goto discard;
+			goto cont;
 		tipc_node_lock(n_ptr);
 
 		/* Locate unicast link endpoint that should handle message */
 		l_ptr = n_ptr->links[b_ptr->identity];
-		if (unlikely(!l_ptr))
-			goto unlock_discard;
+		if (unlikely(!l_ptr)) {
+			tipc_node_unlock(n_ptr);
+			goto cont;
+		}
 
 		/* Verify that communication with node is currently allowed */
 		if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
@@ -1546,8 +1639,10 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 			!msg_redundant_link(msg))
 			n_ptr->block_setup &= ~WAIT_PEER_DOWN;
 
-		if (n_ptr->block_setup)
-			goto unlock_discard;
+		if (n_ptr->block_setup) {
+			tipc_node_unlock(n_ptr);
+			goto cont;
+		}
 
 		/* Validate message sequence number info */
 		seq_no = msg_seqno(msg);
@@ -1583,100 +1678,98 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
 		/* Now (finally!) process the incoming message */
 protocol_check:
-		if (unlikely(!link_working_working(l_ptr))) {
-			if (msg_user(msg) == LINK_PROTOCOL) {
-				link_recv_proto_msg(l_ptr, buf);
-				head = link_insert_deferred_queue(l_ptr, head);
-				tipc_node_unlock(n_ptr);
-				continue;
-			}
-
-			/* Traffic message. Conditionally activate link */
-			link_state_event(l_ptr, TRAFFIC_MSG_EVT);
-
-			if (link_working_working(l_ptr)) {
-				/* Re-insert buffer in front of queue */
-				buf->next = head;
-				head = buf;
+		if (likely(link_working_working(l_ptr))) {
+			if (likely(seq_no == mod(l_ptr->next_in_no))) {
+				l_ptr->next_in_no++;
+				if (unlikely(l_ptr->oldest_deferred_in))
+					head = link_insert_deferred_queue(l_ptr,
+									  head);
+deliver:
+				if (likely(msg_isdata(msg))) {
+					tipc_node_unlock(n_ptr);
+					tipc_port_recv_msg(buf);
+					continue;
+				}
+				switch (msg_user(msg)) {
+					int ret;
+				case MSG_BUNDLER:
+					l_ptr->stats.recv_bundles++;
+					l_ptr->stats.recv_bundled +=
+						msg_msgcnt(msg);
+					tipc_node_unlock(n_ptr);
+					tipc_link_recv_bundle(buf);
+					continue;
+				case NAME_DISTRIBUTOR:
+					n_ptr->bclink.recv_permitted = true;
+					tipc_node_unlock(n_ptr);
+					tipc_named_recv(buf);
+					continue;
+				case BCAST_PROTOCOL:
+					tipc_link_recv_sync(n_ptr, buf);
+					tipc_node_unlock(n_ptr);
+					continue;
+				case CONN_MANAGER:
+					tipc_node_unlock(n_ptr);
+					tipc_port_recv_proto_msg(buf);
+					continue;
+				case MSG_FRAGMENTER:
+					l_ptr->stats.recv_fragments++;
+					ret = tipc_link_recv_fragment(
+						&l_ptr->defragm_buf,
+						&buf, &msg);
+					if (ret == 1) {
+						l_ptr->stats.recv_fragmented++;
+						goto deliver;
+					}
+					if (ret == -1)
+						l_ptr->next_in_no--;
+					break;
+				case CHANGEOVER_PROTOCOL:
+					type = msg_type(msg);
+					if (link_recv_changeover_msg(&l_ptr,
+								     &buf)) {
+						msg = buf_msg(buf);
+						seq_no = msg_seqno(msg);
+						if (type == ORIGINAL_MSG)
+							goto deliver;
+						goto protocol_check;
+					}
+					break;
+				default:
+					kfree_skb(buf);
+					buf = NULL;
+					break;
+				}
 				tipc_node_unlock(n_ptr);
+				tipc_net_route_msg(buf);
 				continue;
 			}
-			goto unlock_discard;
-		}
-
-		/* Link is now in state WORKING_WORKING */
-		if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
 			link_handle_out_of_seq_msg(l_ptr, buf);
 			head = link_insert_deferred_queue(l_ptr, head);
 			tipc_node_unlock(n_ptr);
 			continue;
 		}
-		l_ptr->next_in_no++;
-		if (unlikely(l_ptr->oldest_deferred_in))
+
+		/* Link is not in state WORKING_WORKING */
+		if (msg_user(msg) == LINK_PROTOCOL) {
+			link_recv_proto_msg(l_ptr, buf);
 			head = link_insert_deferred_queue(l_ptr, head);
-deliver:
-		if (likely(msg_isdata(msg))) {
 			tipc_node_unlock(n_ptr);
-			tipc_port_recv_msg(buf);
 			continue;
 		}
-		switch (msg_user(msg)) {
-			int ret;
-		case MSG_BUNDLER:
-			l_ptr->stats.recv_bundles++;
-			l_ptr->stats.recv_bundled += msg_msgcnt(msg);
-			tipc_node_unlock(n_ptr);
-			tipc_link_recv_bundle(buf);
-			continue;
-		case NAME_DISTRIBUTOR:
-			n_ptr->bclink.recv_permitted = true;
-			tipc_node_unlock(n_ptr);
-			tipc_named_recv(buf);
-			continue;
-		case BCAST_PROTOCOL:
-			tipc_link_recv_sync(n_ptr, buf);
-			tipc_node_unlock(n_ptr);
-			continue;
-		case CONN_MANAGER:
-			tipc_node_unlock(n_ptr);
-			tipc_port_recv_proto_msg(buf);
-			continue;
-		case MSG_FRAGMENTER:
-			l_ptr->stats.recv_fragments++;
-			ret = tipc_link_recv_fragment(&l_ptr->reasm_head,
-						      &l_ptr->reasm_tail,
-						      &buf);
-			if (ret == LINK_REASM_COMPLETE) {
-				l_ptr->stats.recv_fragmented++;
-				msg = buf_msg(buf);
-				goto deliver;
-			}
-			if (ret == LINK_REASM_ERROR)
-				tipc_link_reset(l_ptr);
+
+		/* Traffic message. Conditionally activate link */
+		link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+
+		if (link_working_working(l_ptr)) {
+			/* Re-insert buffer in front of queue */
+			buf->next = head;
+			head = buf;
 			tipc_node_unlock(n_ptr);
 			continue;
-		case CHANGEOVER_PROTOCOL:
-			type = msg_type(msg);
-			if (link_recv_changeover_msg(&l_ptr, &buf)) {
-				msg = buf_msg(buf);
-				seq_no = msg_seqno(msg);
-				if (type == ORIGINAL_MSG)
-					goto deliver;
-				goto protocol_check;
-			}
-			break;
-		default:
-			kfree_skb(buf);
-			buf = NULL;
-			break;
 		}
 		tipc_node_unlock(n_ptr);
-		tipc_net_route_msg(buf);
-		continue;
-unlock_discard:
-
-		tipc_node_unlock(n_ptr);
-discard:
+cont:
 		kfree_skb(buf);
 	}
 	read_unlock_bh(&tipc_net_lock);
@@ -2339,48 +2432,114 @@ static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
 }
 
 /*
+ * A pending message being re-assembled must store certain values
+ * to handle subsequent fragments correctly. The following functions
+ * help storing these values in unused, available fields in the
+ * pending message. This makes dynamic memory allocation unnecessary.
+ */
+static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
+{
+	msg_set_seqno(buf_msg(buf), seqno);
+}
+
+static u32 get_fragm_size(struct sk_buff *buf)
+{
+	return msg_ack(buf_msg(buf));
+}
+
+static void set_fragm_size(struct sk_buff *buf, u32 sz)
+{
+	msg_set_ack(buf_msg(buf), sz);
+}
+
+static u32 get_expected_frags(struct sk_buff *buf)
+{
+	return msg_bcast_ack(buf_msg(buf));
+}
+
+static void set_expected_frags(struct sk_buff *buf, u32 exp)
+{
+	msg_set_bcast_ack(buf_msg(buf), exp);
+}
+
+/*
  * tipc_link_recv_fragment(): Called with node lock on. Returns
  * the reassembled buffer if message is complete.
  */
-int tipc_link_recv_fragment(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);
+int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
+			    struct tipc_msg **m)
+{
+	struct sk_buff *prev = NULL;
+	struct sk_buff *fbuf = *fb;
+	struct tipc_msg *fragm = buf_msg(fbuf);
+	struct sk_buff *pbuf = *pending;
+	u32 long_msg_seq_no = msg_long_msgno(fragm);
+
+	*fb = NULL;
+
+	/* Is there an incomplete message waiting for this fragment? */
+	while (pbuf && ((buf_seqno(pbuf) != long_msg_seq_no) ||
+			(msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
+		prev = pbuf;
+		pbuf = pbuf->next;
+	}
+
+	if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
+		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
+		u32 msg_sz = msg_size(imsg);
+		u32 fragm_sz = msg_data_sz(fragm);
+		u32 exp_fragm_cnt;
+		u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
+
+		if (msg_type(imsg) == TIPC_MCAST_MSG)
+			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
+		if (fragm_sz == 0 || msg_size(imsg) > max) {
+			kfree_skb(fbuf);
+			return 0;
+		}
+		exp_fragm_cnt = msg_sz / fragm_sz + !!(msg_sz % fragm_sz);
+		pbuf = tipc_buf_acquire(msg_size(imsg));
+		if (pbuf != NULL) {
+			pbuf->next = *pending;
+			*pending = pbuf;
+			skb_copy_to_linear_data(pbuf, imsg,
+						msg_data_sz(fragm));
+			/*  Prepare buffer for subsequent fragments. */
+			set_long_msg_seqno(pbuf, long_msg_seq_no);
+			set_fragm_size(pbuf, fragm_sz);
+			set_expected_frags(pbuf, exp_fragm_cnt - 1);
+		} else {
+			pr_debug("Link unable to reassemble fragmented message\n");
+			kfree_skb(fbuf);
+			return -1;
+		}
+		kfree_skb(fbuf);
+		return 0;
+	} else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
+		u32 dsz = msg_data_sz(fragm);
+		u32 fsz = get_fragm_size(pbuf);
+		u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
+		u32 exp_frags = get_expected_frags(pbuf) - 1;
+		skb_copy_to_linear_data_offset(pbuf, crs,
+					       msg_data(fragm), dsz);
+		kfree_skb(fbuf);
+
+		/* Is message complete? */
+		if (exp_frags == 0) {
+			if (prev)
+				prev->next = pbuf->next;
+			else
+				*pending = pbuf->next;
+			msg_reset_reroute_cnt(buf_msg(pbuf));
+			*fb = pbuf;
+			*m = buf_msg(pbuf);
+			return 1;
+		}
+		set_expected_frags(pbuf, exp_frags);
 		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;
 	}
+	kfree_skb(fbuf);
 	return 0;
-out_free:
-	pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
-	kfree_skb(*fbuf);
-	return LINK_REASM_ERROR;
 }
 
 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
@@ -2426,21 +2585,25 @@ void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
 static struct tipc_link *link_find_link(const char *name,
 					struct tipc_node **node)
 {
+	struct tipc_link_name link_name_parts;
+	struct tipc_bearer *b_ptr;
 	struct tipc_link *l_ptr;
-	struct tipc_node *n_ptr;
-	int i;
 
-	list_for_each_entry(n_ptr, &tipc_node_list, list) {
-		for (i = 0; i < MAX_BEARERS; i++) {
-			l_ptr = n_ptr->links[i];
-			if (l_ptr && !strcmp(l_ptr->name, name))
-				goto found;
-		}
-	}
-	l_ptr = NULL;
-	n_ptr = NULL;
-found:
-	*node = n_ptr;
+	if (!link_name_validate(name, &link_name_parts))
+		return NULL;
+
+	b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
+	if (!b_ptr)
+		return NULL;
+
+	*node = tipc_node_find(link_name_parts.addr_peer);
+	if (!*node)
+		return NULL;
+
+	l_ptr = (*node)->links[b_ptr->identity];
+	if (!l_ptr || strcmp(l_ptr->name, name))
+		return NULL;
+
 	return l_ptr;
 }
 
@@ -2483,7 +2646,6 @@ static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
 	struct tipc_link *l_ptr;
 	struct tipc_bearer *b_ptr;
 	struct tipc_media *m_ptr;
-	int res = 0;
 
 	l_ptr = link_find_link(name, &node);
 	if (l_ptr) {
@@ -2506,12 +2668,9 @@ static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
 		case TIPC_CMD_SET_LINK_WINDOW:
 			tipc_link_set_queue_limits(l_ptr, new_value);
 			break;
-		default:
-			res = -EINVAL;
-			break;
 		}
 		tipc_node_unlock(node);
-		return res;
+		return 0;
 	}
 
 	b_ptr = tipc_bearer_find(name);
@@ -2519,18 +2678,15 @@ static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
 		switch (cmd) {
 		case TIPC_CMD_SET_LINK_TOL:
 			b_ptr->tolerance = new_value;
-			break;
+			return 0;
 		case TIPC_CMD_SET_LINK_PRI:
 			b_ptr->priority = new_value;
-			break;
+			return 0;
 		case TIPC_CMD_SET_LINK_WINDOW:
 			b_ptr->window = new_value;
-			break;
-		default:
-			res = -EINVAL;
-			break;
+			return 0;
 		}
-		return res;
+		return -EINVAL;
 	}
 
 	m_ptr = tipc_media_find(name);
@@ -2539,18 +2695,15 @@ static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
 	switch (cmd) {
 	case TIPC_CMD_SET_LINK_TOL:
 		m_ptr->tolerance = new_value;
-		break;
+		return 0;
 	case TIPC_CMD_SET_LINK_PRI:
 		m_ptr->priority = new_value;
-		break;
+		return 0;
 	case TIPC_CMD_SET_LINK_WINDOW:
 		m_ptr->window = new_value;
-		break;
-	default:
-		res = -EINVAL;
-		break;
+		return 0;
 	}
-	return res;
+	return -EINVAL;
 }
 
 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,