tipc: transfer broadcast nacks in link state messages

[cascardo/linux.git] / net / tipc / link.c

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2c6e1b9..136316f 100644 (file)
--- 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)