7 files changed, 108 insertions, 27 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index ae469b37d852..753f774cb46f 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -269,18 +269,19 @@ void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked)
  *
  * RCU is locked, no other locks set
  */
-void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
-                         struct tipc_msg *hdr)
+int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
+                        struct tipc_msg *hdr)
 {
         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
         struct sk_buff_head xmitq;
+        int rc = 0;
 
         __skb_queue_head_init(&xmitq);
 
         tipc_bcast_lock(net);
         if (msg_type(hdr) == STATE_MSG) {
                 tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
-                tipc_link_bc_sync_rcv(l, hdr, &xmitq);
+                rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);
         } else {
                 tipc_link_bc_init_rcv(l, hdr);
         }
@@ -291,6 +292,7 @@ void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
         /* Any socket wakeup messages ? */
         if (!skb_queue_empty(inputq))
                 tipc_sk_rcv(net, inputq);
+        return rc;
 }
 
 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h
index d5e79b3767fd..5ffe34472ccd 100644
--- a/net/tipc/bcast.h
+++ b/net/tipc/bcast.h
@@ -56,8 +56,8 @@ int  tipc_bcast_get_mtu(struct net *net);
 int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list);
 int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb);
 void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked);
-void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
-                         struct tipc_msg *hdr);
+int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
+                        struct tipc_msg *hdr);
 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg);
 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[]);
 int tipc_bclink_reset_stats(struct net *net);
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2c6e1b9e024b..136316fb37ec 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -367,6 +367,18 @@ int tipc_link_bc_peers(struct tipc_link *l)
         return l->ackers;
 }
 
+u16 link_bc_rcv_gap(struct tipc_link *l)
+{
+        struct sk_buff *skb = skb_peek(&l->deferdq);
+        u16 gap = 0;
+
+        if (more(l->snd_nxt, l->rcv_nxt))
+                gap = l->snd_nxt - l->rcv_nxt;
+        if (skb)
+                gap = buf_seqno(skb) - l->rcv_nxt;
+        return gap;
+}
+
 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 {
         l->mtu = mtu;
@@ -1135,7 +1147,10 @@ int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
                 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
                         return 0;
                 l->rcv_unacked = 0;
-                return TIPC_LINK_SND_BC_ACK;
+
+                /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
+                l->snd_nxt = l->rcv_nxt;
+                return TIPC_LINK_SND_STATE;
         }
 
         /* Unicast ACK */
@@ -1236,7 +1251,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                         rc |= tipc_link_input(l, skb, l->inputq);
                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
                         rc |= tipc_link_build_state_msg(l, xmitq);
-                if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
+                if (unlikely(rc & ~TIPC_LINK_SND_STATE))
                         break;
         } while ((skb = __skb_dequeue(defq)));
 
@@ -1250,10 +1265,11 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                       u16 rcvgap, int tolerance, int priority,
                                       struct sk_buff_head *xmitq)
 {
+        struct tipc_link *bcl = l->bc_rcvlink;
         struct sk_buff *skb;
         struct tipc_msg *hdr;
         struct sk_buff_head *dfq = &l->deferdq;
-        bool node_up = link_is_up(l->bc_rcvlink);
+        bool node_up = link_is_up(bcl);
         struct tipc_mon_state *mstate = &l->mon_state;
         int dlen = 0;
         void *data;
@@ -1281,7 +1297,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
         msg_set_net_plane(hdr, l->net_plane);
         msg_set_next_sent(hdr, l->snd_nxt);
         msg_set_ack(hdr, l->rcv_nxt - 1);
-        msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
+        msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
         msg_set_link_tolerance(hdr, tolerance);
         msg_set_linkprio(hdr, priority);
@@ -1291,6 +1307,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 
         if (mtyp == STATE_MSG) {
                 msg_set_seq_gap(hdr, rcvgap);
+                msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
                 msg_set_probe(hdr, probe);
                 tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
                 msg_set_size(hdr, INT_H_SIZE + dlen);
@@ -1575,49 +1592,68 @@ void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
 
 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
  */
-void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
-                           struct sk_buff_head *xmitq)
+int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
+                          struct sk_buff_head *xmitq)
 {
         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
+        u16 from = msg_bcast_ack(hdr) + 1;
+        u16 to = from + msg_bc_gap(hdr) - 1;
+        int rc = 0;
 
         if (!link_is_up(l))
-                return;
+                return rc;
 
         if (!msg_peer_node_is_up(hdr))
-                return;
+                return rc;
 
         /* Open when peer ackowledges our bcast init msg (pkt #1) */
         if (msg_ack(hdr))
                 l->bc_peer_is_up = true;
 
         if (!l->bc_peer_is_up)
-                return;
+                return rc;
 
         /* Ignore if peers_snd_nxt goes beyond receive window */
         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
-                return;
+                return rc;
+
+        if (!less(to, from)) {
+                rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
+                l->stats.recv_nacks++;
+        }
+
+        l->snd_nxt = peers_snd_nxt;
+        if (link_bc_rcv_gap(l))
+                rc |= TIPC_LINK_SND_STATE;
+
+        /* Return now if sender supports nack via STATE messages */
+        if (l->peer_caps & TIPC_BCAST_STATE_NACK)
+                return rc;
+
+        /* Otherwise, be backwards compatible */
 
         if (!more(peers_snd_nxt, l->rcv_nxt)) {
                 l->nack_state = BC_NACK_SND_CONDITIONAL;
-                return;
+                return 0;
         }
 
         /* Don't NACK if one was recently sent or peeked */
         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
-                return;
+                return 0;
         }
 
         /* Conditionally delay NACK sending until next synch rcv */
         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
-                        return;
+                        return 0;
         }
 
         /* Send NACK now but suppress next one */
         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
         l->nack_state = BC_NACK_SND_SUPPRESS;
+        return 0;
 }
 
 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
@@ -1654,6 +1690,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
 }
 
 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
+ * This function is here for backwards compatibility, since
+ * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
  */
 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
                           struct sk_buff_head *xmitq)
diff --git a/net/tipc/link.h b/net/tipc/link.h
index d7e9d42fcb2d..d1bd1787a768 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -63,7 +63,7 @@ enum {
 enum {
         TIPC_LINK_UP_EVT       = 1,
         TIPC_LINK_DOWN_EVT     = (1 << 1),
-        TIPC_LINK_SND_BC_ACK   = (1 << 2)
+        TIPC_LINK_SND_STATE    = (1 << 2)
 };
 
 /* Starting value for maximum packet size negotiation on unicast links
@@ -138,8 +138,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
 void tipc_link_build_bc_sync_msg(struct tipc_link *l,
                                  struct sk_buff_head *xmitq);
 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr);
-void tipc_link_bc_sync_rcv(struct tipc_link *l,   struct tipc_msg *hdr,
-                           struct sk_buff_head *xmitq);
+int tipc_link_bc_sync_rcv(struct tipc_link *l,   struct tipc_msg *hdr,
+                          struct sk_buff_head *xmitq);
 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
                           struct sk_buff_head *xmitq);
 #endif
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 7cf52fb39bee..c3832cdf2278 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -719,6 +719,16 @@ static inline char *msg_media_addr(struct tipc_msg *m)
         return (char *)&m->hdr[TIPC_MEDIA_INFO_OFFSET];
 }
 
+static inline u32 msg_bc_gap(struct tipc_msg *m)
+{
+        return msg_bits(m, 8, 0, 0x3ff);
+}
+
+static inline void msg_set_bc_gap(struct tipc_msg *m, u32 n)
+{
+        msg_set_bits(m, 8, 0, 0x3ff, n);
+}
+
 /*
  * Word 9
  */
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 7e8b75fd1a02..7ef14e2d2356 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1262,6 +1262,34 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
         kfree_skb(skb);
 }
 
+static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
+                                  int bearer_id, struct sk_buff_head *xmitq)
+{
+        struct tipc_link *ucl;
+        int rc;
+
+        rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
+
+        if (rc & TIPC_LINK_DOWN_EVT) {
+                tipc_bearer_reset_all(n->net);
+                return;
+        }
+
+        if (!(rc & TIPC_LINK_SND_STATE))
+                return;
+
+        /* If probe message, a STATE response will be sent anyway */
+        if (msg_probe(hdr))
+                return;
+
+        /* Produce a STATE message carrying broadcast NACK */
+        tipc_node_read_lock(n);
+        ucl = n->links[bearer_id].link;
+        if (ucl)
+                tipc_link_build_state_msg(ucl, xmitq);
+        tipc_node_read_unlock(n);
+}
+
 /**
  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
  * @net: the applicable net namespace
@@ -1298,7 +1326,7 @@ static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id
         rc = tipc_bcast_rcv(net, be->link, skb);
 
         /* Broadcast ACKs are sent on a unicast link */
-        if (rc & TIPC_LINK_SND_BC_ACK) {
+        if (rc & TIPC_LINK_SND_STATE) {
                 tipc_node_read_lock(n);
                 tipc_link_build_state_msg(le->link, &xmitq);
                 tipc_node_read_unlock(n);
@@ -1505,7 +1533,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 
         /* 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);
+                tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
         else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
                 tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
 
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 4578b34c7dca..39ef54c1f2ad 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -1,7 +1,7 @@
 /*
  * net/tipc/node.h: Include file for TIPC node management routines
  *
- * Copyright (c) 2000-2006, 2014-2015, Ericsson AB
+ * Copyright (c) 2000-2006, 2014-2016, Ericsson AB
  * Copyright (c) 2005, 2010-2014, Wind River Systems
  * All rights reserved.
  *
@@ -45,11 +45,14 @@
 /* Optional capabilities supported by this code version
  */
 enum {
-        TIPC_BCAST_SYNCH   = (1 << 1),
-        TIPC_BLOCK_FLOWCTL = (2 << 1)
+        TIPC_BCAST_SYNCH      = (1 << 1),
+        TIPC_BCAST_STATE_NACK = (1 << 2),
+        TIPC_BLOCK_FLOWCTL    = (1 << 3)
 };
 
-#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | TIPC_BLOCK_FLOWCTL)
+#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
+                                TIPC_BCAST_STATE_NACK | \
+                                TIPC_BLOCK_FLOWCTL)
 #define INVALID_BEARER_ID -1
 
 void tipc_node_stop(struct net *net);