Merge branch 'tipc-next'

Jon Maloy says:

====================
tipc: improve broadcast implementation

The TIPC broadcast link implementation is currently complex and hard to
follow. It also incurs some amount of code and structure duplication,
something that can be reduced significantly with a little effort.

This commit series introduces a number of improvements which address
both the locking structure, the code/structure duplication issue, and
the overall readbility of the code.

The series consists of three main parts:

1-7: Adaptation to the new link structure, and preparation for the next
     step. In particular, we want the broadcast transmission link to
     have a life cycle that is longer than any of its potential (unicast
     and broadcast receive links) users. This eliminates the need to
     always test for the presence of this link before accessing it.

8-10: This is what is really new in this series. Commit #9 is by far
      the largest and most important one, because it moves most of
      the broadcast functionality into link.c, partially reusing the
      fields and functionality of the unicast link. The removal of
      the "node_map" infrastructure in commit #10 is also an important
      achievement.

11-16: Some improvements leveraging the changes made in the previous
       commits.

The series needs commit 53387c4e22ac ("tipc: extend broadcast link window size")
and commit e53567948f82 ("tipc: conditionally expand buffer headroom over udp tunnel")
which are both present in 'net' but not yet in 'net-next', to apply cleanly.
====================

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

1 files changed, 120 insertions, 64 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 2670751d0e2e..7493506b069b 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -72,7 +72,6 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
 				bool delete);
 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
-static void node_established_contact(struct tipc_node *n_ptr);
 static void tipc_node_delete(struct tipc_node *node);
 static void tipc_node_timeout(unsigned long data);
 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
@@ -165,8 +164,10 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
 	INIT_LIST_HEAD(&n_ptr->list);
 	INIT_LIST_HEAD(&n_ptr->publ_list);
 	INIT_LIST_HEAD(&n_ptr->conn_sks);
-	skb_queue_head_init(&n_ptr->bclink.namedq);
-	__skb_queue_head_init(&n_ptr->bclink.deferdq);
+	skb_queue_head_init(&n_ptr->bc_entry.namedq);
+	skb_queue_head_init(&n_ptr->bc_entry.inputq1);
+	__skb_queue_head_init(&n_ptr->bc_entry.arrvq);
+	skb_queue_head_init(&n_ptr->bc_entry.inputq2);
 	hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 		if (n_ptr->addr < temp_node->addr)
@@ -177,6 +178,18 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
 	n_ptr->signature = INVALID_NODE_SIG;
 	n_ptr->active_links[0] = INVALID_BEARER_ID;
 	n_ptr->active_links[1] = INVALID_BEARER_ID;
+	if (!tipc_link_bc_create(net, tipc_own_addr(net), n_ptr->addr,
+				 U16_MAX, tipc_bc_sndlink(net)->window,
+				 n_ptr->capabilities,
+				 &n_ptr->bc_entry.inputq1,
+				 &n_ptr->bc_entry.namedq,
+				 tipc_bc_sndlink(net),
+				 &n_ptr->bc_entry.link)) {
+		pr_warn("Broadcast rcv link creation failed, no memory\n");
+		kfree(n_ptr);
+		n_ptr = NULL;
+		goto exit;
+	}
 	tipc_node_get(n_ptr);
 	setup_timer(&n_ptr->timer, tipc_node_timeout, (unsigned long)n_ptr);
 	n_ptr->keepalive_intv = U32_MAX;
@@ -203,6 +216,7 @@ static void tipc_node_delete(struct tipc_node *node)
 {
 	list_del_rcu(&node->list);
 	hlist_del_rcu(&node->hash);
+	kfree(node->bc_entry.link);
 	kfree_rcu(node, rcu);
 }
 
@@ -332,6 +346,7 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
 	n->links[bearer_id].mtu = nl->mtu - INT_H_SIZE;
 
 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
+	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
 
 	pr_debug("Established link <%s> on network plane %c\n",
 		 nl->name, nl->net_plane);
@@ -340,8 +355,9 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
 	if (!ol) {
 		*slot0 = bearer_id;
 		*slot1 = bearer_id;
-		tipc_link_build_bcast_sync_msg(nl, xmitq);
-		node_established_contact(n);
+		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
+		n->action_flags |= TIPC_NOTIFY_NODE_UP;
+		tipc_bcast_add_peer(n->net, nl, xmitq);
 		return;
 	}
 
@@ -350,8 +366,11 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
 		pr_debug("Old link <%s> becomes standby\n", ol->name);
 		*slot0 = bearer_id;
 		*slot1 = bearer_id;
+		tipc_link_set_active(nl, true);
+		tipc_link_set_active(ol, false);
 	} else if (nl->priority == ol->priority) {
-		*slot0 = bearer_id;
+		tipc_link_set_active(nl, true);
+		*slot1 = bearer_id;
 	} else {
 		pr_debug("New link <%s> is standby\n", nl->name);
 	}
@@ -428,8 +447,10 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 		tipc_link_build_reset_msg(l, xmitq);
 		*maddr = &n->links[*bearer_id].maddr;
 		node_lost_contact(n, &le->inputq);
+		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
 		return;
 	}
+	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
 
 	/* There is still a working link => initiate failover */
 	tnl = node_active_link(n, 0);
@@ -493,6 +514,7 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 	bool link_up = false;
 	bool accept_addr = false;
 	bool reset = true;
+	char *if_name;
 
 	*dupl_addr = false;
 	*respond = false;
@@ -579,9 +601,15 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 			pr_warn("Cannot establish 3rd link to %x\n", n->addr);
 			goto exit;
 		}
-		if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
-				      tipc_own_addr(net), onode, &le->maddr,
-				      &le->inputq, &n->bclink.namedq, &l)) {
+		if_name = strchr(b->name, ':') + 1;
+		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
+				      b->net_plane, b->mtu, b->priority,
+				      b->window, mod(tipc_net(net)->random),
+				      tipc_own_addr(net), onode,
+				      n->capabilities,
+				      tipc_bc_sndlink(n->net), n->bc_entry.link,
+				      &le->inputq,
+				      &n->bc_entry.namedq, &l)) {
 			*respond = false;
 			goto exit;
 		}
@@ -824,58 +852,36 @@ bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
 	return true;
 }
 
-static void node_established_contact(struct tipc_node *n_ptr)
-{
-	tipc_node_fsm_evt(n_ptr, SELF_ESTABL_CONTACT_EVT);
-	n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
-	n_ptr->bclink.oos_state = 0;
-	n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net);
-	tipc_bclink_add_node(n_ptr->net, n_ptr->addr);
-}
-
-static void node_lost_contact(struct tipc_node *n_ptr,
+static void node_lost_contact(struct tipc_node *n,
 			      struct sk_buff_head *inputq)
 {
 	char addr_string[16];
 	struct tipc_sock_conn *conn, *safe;
 	struct tipc_link *l;
-	struct list_head *conns = &n_ptr->conn_sks;
+	struct list_head *conns = &n->conn_sks;
 	struct sk_buff *skb;
-	struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 	uint i;
 
 	pr_debug("Lost contact with %s\n",
-		 tipc_addr_string_fill(addr_string, n_ptr->addr));
+		 tipc_addr_string_fill(addr_string, n->addr));
 
-	/* Flush broadcast link info associated with lost node */
-	if (n_ptr->bclink.recv_permitted) {
-		__skb_queue_purge(&n_ptr->bclink.deferdq);
-
-		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->net, n_ptr->addr);
-		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
-
-		n_ptr->bclink.recv_permitted = false;
-	}
+	/* Clean up broadcast state */
+	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
 
 	/* Abort any ongoing link failover */
 	for (i = 0; i < MAX_BEARERS; i++) {
-		l = n_ptr->links[i].link;
+		l = n->links[i].link;
 		if (l)
 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
 	}
 
 	/* Notify publications from this node */
-	n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN;
+	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
 
 	/* Notify sockets connected to node */
 	list_for_each_entry_safe(conn, safe, conns, list) {
 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
-				      SHORT_H_SIZE, 0, tn->own_addr,
+				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
 				      conn->peer_node, conn->port,
 				      conn->peer_port, TIPC_ERR_NO_NODE);
 		if (likely(skb))
@@ -937,18 +943,13 @@ void tipc_node_unlock(struct tipc_node *node)
 	publ_list = &node->publ_list;
 
 	node->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
-				TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP |
-				TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT |
-				TIPC_BCAST_RESET);
+				TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
 
 	spin_unlock_bh(&node->lock);
 
 	if (flags & TIPC_NOTIFY_NODE_DOWN)
 		tipc_publ_notify(net, publ_list, addr);
 
-	if (flags & TIPC_WAKEUP_BCAST_USERS)
-		tipc_bclink_wakeup_users(net);
-
 	if (flags & TIPC_NOTIFY_NODE_UP)
 		tipc_named_node_up(net, addr);
 
@@ -960,11 +961,6 @@ void tipc_node_unlock(struct tipc_node *node)
 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
 				      link_id, addr);
 
-	if (flags & TIPC_BCAST_MSG_EVT)
-		tipc_bclink_input(net);
-
-	if (flags & TIPC_BCAST_RESET)
-		tipc_node_reset_links(node);
 }
 
 /* Caller should hold node lock for the passed node */
@@ -1080,6 +1076,67 @@ int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 }
 
 /**
+ * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
+ * @net: the applicable net namespace
+ * @skb: TIPC packet
+ * @bearer_id: id of bearer message arrived on
+ *
+ * Invoked with no locks held.
+ */
+void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
+{
+	int rc;
+	struct sk_buff_head xmitq;
+	struct tipc_bclink_entry *be;
+	struct tipc_link_entry *le;
+	struct tipc_msg *hdr = buf_msg(skb);
+	int usr = msg_user(hdr);
+	u32 dnode = msg_destnode(hdr);
+	struct tipc_node *n;
+
+	__skb_queue_head_init(&xmitq);
+
+	/* If NACK for other node, let rcv link for that node peek into it */
+	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
+		n = tipc_node_find(net, dnode);
+	else
+		n = tipc_node_find(net, msg_prevnode(hdr));
+	if (!n) {
+		kfree_skb(skb);
+		return;
+	}
+	be = &n->bc_entry;
+	le = &n->links[bearer_id];
+
+	rc = tipc_bcast_rcv(net, be->link, skb);
+
+	/* Broadcast link reset may happen at reassembly failure */
+	if (rc & TIPC_LINK_DOWN_EVT)
+		tipc_node_reset_links(n);
+
+	/* Broadcast ACKs are sent on a unicast link */
+	if (rc & TIPC_LINK_SND_BC_ACK) {
+		tipc_node_lock(n);
+		tipc_link_build_ack_msg(le->link, &xmitq);
+		tipc_node_unlock(n);
+	}
+
+	if (!skb_queue_empty(&xmitq))
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+
+	/* Deliver. 'arrvq' is under inputq2's lock protection */
+	if (!skb_queue_empty(&be->inputq1)) {
+		spin_lock_bh(&be->inputq2.lock);
+		spin_lock_bh(&be->inputq1.lock);
+		skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
+		spin_unlock_bh(&be->inputq1.lock);
+		spin_unlock_bh(&be->inputq2.lock);
+		tipc_sk_mcast_rcv(net, &be->arrvq, &be->inputq2);
+	}
+	tipc_node_put(n);
+}
+
+/**
  * tipc_node_check_state - check and if necessary update node state
  * @skb: TIPC packet
  * @bearer_id: identity of bearer delivering the packet
@@ -1221,6 +1278,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 	int usr = msg_user(hdr);
 	int bearer_id = b->identity;
 	struct tipc_link_entry *le;
+	u16 bc_ack = msg_bcast_ack(hdr);
 	int rc = 0;
 
 	__skb_queue_head_init(&xmitq);
@@ -1229,13 +1287,12 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 	if (unlikely(!tipc_msg_validate(skb)))
 		goto discard;
 
-	/* Handle arrival of a non-unicast link packet */
+	/* Handle arrival of discovery or broadcast packet */
 	if (unlikely(msg_non_seq(hdr))) {
-		if (usr ==  LINK_CONFIG)
-			tipc_disc_rcv(net, skb, b);
+		if (unlikely(usr == LINK_CONFIG))
+			return tipc_disc_rcv(net, skb, b);
 		else
-			tipc_bclink_rcv(net, skb);
-		return;
+			return tipc_node_bc_rcv(net, skb, bearer_id);
 	}
 
 	/* Locate neighboring node that sent packet */
@@ -1244,19 +1301,18 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 		goto discard;
 	le = &n->links[bearer_id];
 
+	/* Ensure broadcast reception is in synch with peer's send state */
+	if (unlikely(usr == LINK_PROTOCOL))
+		tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr);
+	else if (unlikely(n->bc_entry.link->acked != bc_ack))
+		tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
+
 	tipc_node_lock(n);
 
 	/* Is reception permitted at the moment ? */
 	if (!tipc_node_filter_pkt(n, hdr))
 		goto unlock;
 
-	if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
-		tipc_bclink_sync_state(n, hdr);
-
-	/* Release acked broadcast packets */
-	if (unlikely(n->bclink.acked != msg_bcast_ack(hdr)))
-		tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
-
 	/* Check and if necessary update node state */
 	if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
 		rc = tipc_link_rcv(le->link, skb, &xmitq);
@@ -1271,8 +1327,8 @@ unlock:
 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
 		tipc_node_link_down(n, bearer_id, false);
 
-	if (unlikely(!skb_queue_empty(&n->bclink.namedq)))
-		tipc_named_rcv(net, &n->bclink.namedq);
+	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
+		tipc_named_rcv(net, &n->bc_entry.namedq);
 
 	if (!skb_queue_empty(&le->inputq))
 		tipc_sk_rcv(net, &le->inputq);