tipc: permit overlapping service ranges in name table

With the new RB tree structure for service ranges it becomes possible to
solve an old problem; - we can now allow overlapping service ranges in
the table.

When inserting a new service range to the tree, we use 'lower' as primary
key, and when necessary 'upper' as secondary key.

Since there may now be multiple service ranges matching an indicated
'lower' value, we must also add the 'upper' value to the functions
used for removing publications, so that the correct, corresponding
range item can be found.

These changes guarantee that a well-formed publication/withdrawal item
from a peer node never will be rejected, and make it possible to
eliminate the problematic backlog functionality we currently have for
handling such cases.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 60 insertions, 111 deletions

diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
index 8240a85b0d0c..51b4b96f89db 100644
--- a/net/tipc/name_distr.c
+++ b/net/tipc/name_distr.c
@@ -204,12 +204,12 @@ void tipc_named_node_up(struct net *net, u32 dnode)
  */
 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 {
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_net *tn = tipc_net(net);
 	struct publication *p;
 
 	spin_lock_bh(&tn->nametbl_lock);
-	p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
-				     publ->node, publ->port, publ->key);
+	p = tipc_nametbl_remove_publ(net, publ->type, publ->lower, publ->upper,
+				     publ->node, publ->key);
 	if (p)
 		tipc_node_unsubscribe(net, &p->binding_node, addr);
 	spin_unlock_bh(&tn->nametbl_lock);
@@ -261,28 +261,31 @@ void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 				u32 node, u32 dtype)
 {
-	struct publication *publ = NULL;
+	struct publication *p = NULL;
+	u32 lower = ntohl(i->lower);
+	u32 upper = ntohl(i->upper);
+	u32 type = ntohl(i->type);
+	u32 port = ntohl(i->port);
+	u32 key = ntohl(i->key);
 
 	if (dtype == PUBLICATION) {
-		publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
-						ntohl(i->lower),
-						ntohl(i->upper),
-						TIPC_CLUSTER_SCOPE, node,
-						ntohl(i->port), ntohl(i->key));
-		if (publ) {
-			tipc_node_subscribe(net, &publ->binding_node, node);
+		p = tipc_nametbl_insert_publ(net, type, lower, upper,
+					     TIPC_CLUSTER_SCOPE, node,
+					     port, key);
+		if (p) {
+			tipc_node_subscribe(net, &p->binding_node, node);
 			return true;
 		}
 	} else if (dtype == WITHDRAWAL) {
-		publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
-						ntohl(i->lower),
-						node, ntohl(i->port),
-						ntohl(i->key));
-		if (publ) {
-			tipc_node_unsubscribe(net, &publ->binding_node, node);
-			kfree_rcu(publ, rcu);
+		p = tipc_nametbl_remove_publ(net, type, lower,
+					     upper, node, key);
+		if (p) {
+			tipc_node_unsubscribe(net, &p->binding_node, node);
+			kfree_rcu(p, rcu);
 			return true;
 		}
+		pr_warn_ratelimited("Failed to remove binding %u,%u from %x\n",
+				    type, lower, node);
 	} else {
 		pr_warn("Unrecognized name table message received\n");
 	}
@@ -290,53 +293,6 @@ static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 }
 
 /**
- * tipc_named_add_backlog - add a failed name table update to the backlog
- *
- */
-static void tipc_named_add_backlog(struct net *net, struct distr_item *i,
-				   u32 type, u32 node)
-{
-	struct distr_queue_item *e;
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	unsigned long now = get_jiffies_64();
-
-	e = kzalloc(sizeof(*e), GFP_ATOMIC);
-	if (!e)
-		return;
-	e->dtype = type;
-	e->node = node;
-	e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
-	memcpy(e, i, sizeof(*i));
-	list_add_tail(&e->next, &tn->dist_queue);
-}
-
-/**
- * tipc_named_process_backlog - try to process any pending name table updates
- * from the network.
- */
-void tipc_named_process_backlog(struct net *net)
-{
-	struct distr_queue_item *e, *tmp;
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	unsigned long now = get_jiffies_64();
-
-	list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
-		if (time_after(e->expires, now)) {
-			if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
-				continue;
-		} else {
-			pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %x key=%u\n",
-					    e->dtype, ntohl(e->i.type),
-					    ntohl(e->i.lower),
-					    ntohl(e->i.upper),
-					    e->node, ntohl(e->i.key));
-		}
-		list_del(&e->next);
-		kfree(e);
-	}
-}
-
-/**
  * tipc_named_rcv - process name table update messages sent by another node
  */
 void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
@@ -358,12 +314,10 @@ void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
 		count = msg_data_sz(msg) / ITEM_SIZE;
 		node = msg_orignode(msg);
 		while (count--) {
-			if (!tipc_update_nametbl(net, item, node, mtype))
-				tipc_named_add_backlog(net, item, mtype, node);
+			tipc_update_nametbl(net, item, node, mtype);
 			item++;
 		}
 		kfree_skb(skb);
-		tipc_named_process_backlog(net);
 	}
 	spin_unlock_bh(&tn->nametbl_lock);
 }
diff --git a/net/tipc/name_distr.h b/net/tipc/name_distr.h
index 4753e628d7c4..63fc73e0fa6c 100644
--- a/net/tipc/name_distr.h
+++ b/net/tipc/name_distr.h
@@ -72,7 +72,6 @@ struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ);
 void tipc_named_node_up(struct net *net, u32 dnode);
 void tipc_named_rcv(struct net *net, struct sk_buff_head *msg_queue);
 void tipc_named_reinit(struct net *net);
-void tipc_named_process_backlog(struct net *net);
 void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr);
 
 #endif
diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c
index 4bdc580c533b..b1fe20972aa9 100644
--- a/net/tipc/name_table.c
+++ b/net/tipc/name_table.c
@@ -171,10 +171,14 @@ static struct service_range *tipc_service_create_range(struct tipc_service *sc,
 		tmp = container_of(parent, struct service_range, tree_node);
 		if (lower < tmp->lower)
 			n = &(*n)->rb_left;
+		else if (lower > tmp->lower)
+			n = &(*n)->rb_right;
+		else if (upper < tmp->upper)
+			n = &(*n)->rb_left;
 		else if (upper > tmp->upper)
 			n = &(*n)->rb_right;
 		else
-			return NULL;
+			return tmp;
 	}
 	sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
 	if (!sr)
@@ -200,17 +204,11 @@ static struct publication *tipc_service_insert_publ(struct net *net,
 	struct publication *p;
 	bool first = false;
 
-	sr = tipc_service_find_range(sc, lower);
-	if (!sr) {
-		sr = tipc_service_create_range(sc, lower, upper);
-		if (!sr)
-			goto  err;
-		first = true;
-	}
+	sr = tipc_service_create_range(sc, lower, upper);
+	if (!sr)
+		goto  err;
 
-	/* Lower end overlaps existing entry, but we need an exact match */
-	if (sr->lower != lower || sr->upper != upper)
-		return NULL;
+	first = list_empty(&sr->all_publ);
 
 	/* Return if the publication already exists */
 	list_for_each_entry(p, &sr->all_publ, all_publ) {
@@ -239,30 +237,32 @@ err:
 
 /**
  * tipc_service_remove_publ - remove a publication from a service
- *
- * NOTE: There may be cases where TIPC is asked to remove a publication
- * that is not in the name table.  For example, if another node issues a
- * publication for a name range that overlaps an existing name range
- * the publication will not be recorded, which means the publication won't
- * be found when the name range is later withdrawn by that node.
- * A failed withdraw request simply returns a failure indication and lets the
- * caller issue any error or warning messages associated with such a problem.
  */
 static struct publication *tipc_service_remove_publ(struct net *net,
 						    struct tipc_service *sc,
-						    u32 inst, u32 node,
-						    u32 port, u32 key)
+						    u32 lower, u32 upper,
+						    u32 node, u32 key)
 {
 	struct tipc_subscription *sub, *tmp;
 	struct service_range *sr;
 	struct publication *p;
 	bool found = false;
 	bool last = false;
+	struct rb_node *n;
 
-	sr = tipc_service_find_range(sc, inst);
+	sr = tipc_service_find_range(sc, lower);
 	if (!sr)
 		return NULL;
 
+	/* Find exact matching service range */
+	for (n = &sr->tree_node; n; n = rb_next(n)) {
+		sr = container_of(n, struct service_range, tree_node);
+		if (sr->upper == upper)
+			break;
+	}
+	if (!n || sr->lower != lower || sr->upper != upper)
+		return NULL;
+
 	/* Find publication, if it exists */
 	list_for_each_entry(p, &sr->all_publ, all_publ) {
 		if (p->key != key || (node && node != p->node))
@@ -375,8 +375,8 @@ struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 }
 
 struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
-						 u32 lower, u32 node, u32 port,
-						 u32 key)
+					     u32 lower, u32 upper,
+					     u32 node, u32 key)
 {
 	struct tipc_service *sc = tipc_service_find(net, type);
 	struct publication *p = NULL;
@@ -385,7 +385,7 @@ struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 		return NULL;
 
 	spin_lock_bh(&sc->lock);
-	p = tipc_service_remove_publ(net, sc, lower, node, port, key);
+	p = tipc_service_remove_publ(net, sc, lower, upper, node, key);
 
 	/* Delete service item if this no more publications and subscriptions */
 	if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
@@ -620,8 +620,6 @@ struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 	if (p) {
 		nt->local_publ_count++;
 		skb = tipc_named_publish(net, p);
-		/* Any pending external events? */
-		tipc_named_process_backlog(net);
 	}
 exit:
 	spin_unlock_bh(&tn->nametbl_lock);
@@ -635,7 +633,7 @@ exit:
  * tipc_nametbl_withdraw - withdraw a service binding
  */
 int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
-			  u32 port, u32 key)
+			  u32 upper, u32 key)
 {
 	struct name_table *nt = tipc_name_table(net);
 	struct tipc_net *tn = tipc_net(net);
@@ -645,17 +643,15 @@ int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
 
 	spin_lock_bh(&tn->nametbl_lock);
 
-	p = tipc_nametbl_remove_publ(net, type, lower, self, port, key);
+	p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
 	if (p) {
 		nt->local_publ_count--;
 		skb = tipc_named_withdraw(net, p);
-		/* Any pending external events? */
-		tipc_named_process_backlog(net);
 		list_del_init(&p->binding_sock);
 		kfree_rcu(p, rcu);
 	} else {
 		pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
-		       type, lower, port, key);
+		       type, lower, upper, key);
 	}
 	spin_unlock_bh(&tn->nametbl_lock);
 
@@ -754,8 +750,8 @@ static void tipc_service_delete(struct net *net, struct tipc_service *sc)
 	rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
 		list_for_each_entry_safe(p, tmpb,
 					 &sr->all_publ, all_publ) {
-			tipc_service_remove_publ(net, sc, p->lower, p->node,
-						 p->port, p->key);
+			tipc_service_remove_publ(net, sc, p->lower, p->upper,
+						 p->node, p->key);
 			kfree_rcu(p, rcu);
 		}
 	}
diff --git a/net/tipc/name_table.h b/net/tipc/name_table.h
index 1b03b8751707..4b14fc28d9e2 100644
--- a/net/tipc/name_table.h
+++ b/net/tipc/name_table.h
@@ -116,16 +116,16 @@ bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 domain,
 			 struct list_head *dsts, int *dstcnt, u32 exclude,
 			 bool all);
 struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
-					 u32 upper, u32 scope, u32 port_ref,
+					 u32 upper, u32 scope, u32 port,
 					 u32 key);
-int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 ref,
+int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 upper,
 			  u32 key);
 struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 					     u32 lower, u32 upper, u32 scope,
 					     u32 node, u32 ref, u32 key);
 struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
-					     u32 lower, u32 node, u32 ref,
-					     u32 key);
+					     u32 lower, u32 upper,
+					     u32 node, u32 key);
 void tipc_nametbl_subscribe(struct tipc_subscription *s);
 void tipc_nametbl_unsubscribe(struct tipc_subscription *s);
 int tipc_nametbl_init(struct net *net);
diff --git a/net/tipc/net.c b/net/tipc/net.c
index 29538dc00857..856f9e97ea29 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -136,7 +136,7 @@ void tipc_net_stop(struct net *net)
 	if (!self)
 		return;
 
-	tipc_nametbl_withdraw(net, TIPC_CFG_SRV, self, 0, self);
+	tipc_nametbl_withdraw(net, TIPC_CFG_SRV, self, self, self);
 	rtnl_lock();
 	tipc_bearer_stop(net);
 	tipc_node_stop(net);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 85e777e00ec9..c77dd2f3c589 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -329,7 +329,7 @@ static void tipc_node_write_unlock(struct tipc_node *n)
 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
 		tipc_mon_peer_down(net, addr, bearer_id);
 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
-				      link_id, link_id);
+				      addr, link_id);
 	}
 }
 
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 275b666f6231..3e5eba30865e 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2634,12 +2634,12 @@ static int tipc_sk_withdraw(struct tipc_sock *tsk, uint scope,
 			if (publ->upper != seq->upper)
 				break;
 			tipc_nametbl_withdraw(net, publ->type, publ->lower,
-					      publ->port, publ->key);
+					      publ->upper, publ->key);
 			rc = 0;
 			break;
 		}
 		tipc_nametbl_withdraw(net, publ->type, publ->lower,
-				      publ->port, publ->key);
+				      publ->upper, publ->key);
 		rc = 0;
 	}
 	if (list_empty(&tsk->publications))