tipc: eliminate link's reference to owner node
[cascardo/linux.git] / net / tipc / link.c
index dfc738e..819fb71 100644 (file)
@@ -76,6 +76,14 @@ static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
        [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
 };
 
+/* Send states for broadcast NACKs
+ */
+enum {
+       BC_NACK_SND_CONDITIONAL,
+       BC_NACK_SND_UNCONDITIONAL,
+       BC_NACK_SND_SUPPRESS,
+};
+
 /*
  * Interval between NACKs when packets arrive out of order
  */
@@ -111,7 +119,11 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                      struct sk_buff_head *xmitq);
 static void link_reset_statistics(struct tipc_link *l_ptr);
 static void link_print(struct tipc_link *l_ptr, const char *str);
-static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
+static void tipc_link_build_nack_msg(struct tipc_link *l,
+                                    struct sk_buff_head *xmitq);
+static void tipc_link_build_bc_init_msg(struct tipc_link *l,
+                                       struct sk_buff_head *xmitq);
+static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
 
 /*
  *  Simple non-static link routines (i.e. referenced outside this file)
@@ -151,11 +163,66 @@ bool tipc_link_is_blocked(struct tipc_link *l)
        return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 }
 
+bool link_is_bc_sndlink(struct tipc_link *l)
+{
+       return !l->bc_sndlink;
+}
+
+bool link_is_bc_rcvlink(struct tipc_link *l)
+{
+       return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
+}
+
 int tipc_link_is_active(struct tipc_link *l)
 {
-       struct tipc_node *n = l->owner;
+       return l->active;
+}
+
+void tipc_link_set_active(struct tipc_link *l, bool active)
+{
+       l->active = active;
+}
+
+void tipc_link_add_bc_peer(struct tipc_link *snd_l,
+                          struct tipc_link *uc_l,
+                          struct sk_buff_head *xmitq)
+{
+       struct tipc_link *rcv_l = uc_l->bc_rcvlink;
+
+       snd_l->ackers++;
+       rcv_l->acked = snd_l->snd_nxt - 1;
+       tipc_link_build_bc_init_msg(uc_l, xmitq);
+}
+
+void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
+                             struct tipc_link *rcv_l,
+                             struct sk_buff_head *xmitq)
+{
+       u16 ack = snd_l->snd_nxt - 1;
+
+       snd_l->ackers--;
+       tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
+       tipc_link_reset(rcv_l);
+       rcv_l->state = LINK_RESET;
+       if (!snd_l->ackers) {
+               tipc_link_reset(snd_l);
+               __skb_queue_purge(xmitq);
+       }
+}
+
+int tipc_link_bc_peers(struct tipc_link *l)
+{
+       return l->ackers;
+}
+
+void tipc_link_set_mtu(struct tipc_link *l, int mtu)
+{
+       l->mtu = mtu;
+}
 
-       return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
+int tipc_link_mtu(struct tipc_link *l)
+{
+       return l->mtu;
 }
 
 static u32 link_own_addr(struct tipc_link *l)
@@ -176,18 +243,25 @@ static u32 link_own_addr(struct tipc_link *l)
  * @session: session to be used by link
  * @ownnode: identity of own node
  * @peer: node id of peer node
+ * @peer_caps: bitmap describing peer node capabilities
  * @maddr: media address to be used
+ * @bc_sndlink: the namespace global link used for broadcast sending
+ * @bc_rcvlink: the peer specific link used for broadcast reception
  * @inputq: queue to put messages ready for delivery
  * @namedq: queue to put binding table update messages ready for delivery
  * @link: return value, pointer to put the created link
  *
  * Returns true if link was created, otherwise false
  */
-bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
+bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
                      int tolerance, char net_plane, u32 mtu, int priority,
                      int window, u32 session, u32 ownnode, u32 peer,
+                     u16 peer_caps,
                      struct tipc_media_addr *maddr,
-                     struct sk_buff_head *inputq, struct sk_buff_head *namedq,
+                     struct tipc_link *bc_sndlink,
+                     struct tipc_link *bc_rcvlink,
+                     struct sk_buff_head *inputq,
+                     struct sk_buff_head *namedq,
                      struct tipc_link **link)
 {
        struct tipc_link *l;
@@ -211,8 +285,9 @@ bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
        strcpy((char *)msg_data(hdr), if_name);
 
        l->addr = peer;
+       l->peer_caps = peer_caps;
        l->media_addr = maddr;
-       l->owner = n;
+       l->net = net;
        l->peer_session = WILDCARD_SESSION;
        l->bearer_id = bearer_id;
        l->tolerance = tolerance;
@@ -222,6 +297,8 @@ bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
        l->priority = priority;
        tipc_link_set_queue_limits(l, window);
        l->ackers = 1;
+       l->bc_sndlink = bc_sndlink;
+       l->bc_rcvlink = bc_rcvlink;
        l->inputq = inputq;
        l->namedq = namedq;
        l->state = LINK_RESETTING;
@@ -244,44 +321,32 @@ bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
  *
  * Returns true if link was created, otherwise false
  */
-bool tipc_link_bc_create(struct tipc_node *n, int mtu, int window,
+bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
+                        int mtu, int window, u16 peer_caps,
                         struct sk_buff_head *inputq,
                         struct sk_buff_head *namedq,
+                        struct tipc_link *bc_sndlink,
                         struct tipc_link **link)
 {
        struct tipc_link *l;
 
-       if (!tipc_link_create(n, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
-                             0, 0, 0, NULL, inputq, namedq, link))
+       if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
+                             0, ownnode, peer, peer_caps, NULL, bc_sndlink,
+                             NULL, inputq, namedq, link))
                return false;
 
        l = *link;
        strcpy(l->name, tipc_bclink_name);
        tipc_link_reset(l);
-       return true;
-}
+       l->state = LINK_RESET;
+       l->ackers = 0;
+       l->bc_rcvlink = l;
 
-/* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
- *
- * Give a newly added peer node the sequence number where it should
- * start receiving and acking broadcast packets.
- */
-void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
-                                   struct sk_buff_head *xmitq)
-{
-       struct sk_buff *skb;
-       struct sk_buff_head list;
-       u16 last_sent;
+       /* Broadcast send link is always up */
+       if (link_is_bc_sndlink(l))
+               l->state = LINK_ESTABLISHED;
 
-       skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
-                             0, l->addr, link_own_addr(l), 0, 0, 0);
-       if (!skb)
-               return;
-       last_sent = tipc_bclink_get_last_sent(l->owner->net);
-       msg_set_last_bcast(buf_msg(skb), last_sent);
-       __skb_queue_head_init(&list);
-       __skb_queue_tail(&list, skb);
-       tipc_link_xmit(l, &list, xmitq);
+       return true;
 }
 
 /**
@@ -486,6 +551,8 @@ static void link_profile_stats(struct tipc_link *l)
                l->stats.msg_length_profile[6]++;
 }
 
+/* tipc_link_timeout - perform periodic task as instructed from node timeout
+ */
 /* tipc_link_timeout - perform periodic task as instructed from node timeout
  */
 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
@@ -494,6 +561,9 @@ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
        int mtyp = STATE_MSG;
        bool xmit = false;
        bool prb = false;
+       u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
+       u16 bc_acked = l->bc_rcvlink->acked;
+       bool bc_up = link_is_up(l->bc_rcvlink);
 
        link_profile_stats(l);
 
@@ -501,7 +571,7 @@ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
        case LINK_ESTABLISHED:
        case LINK_SYNCHING:
                if (!l->silent_intv_cnt) {
-                       if (tipc_bclink_acks_missing(l->owner))
+                       if (bc_up && (bc_acked != bc_snt))
                                xmit = true;
                } else if (l->silent_intv_cnt <= l->abort_limit) {
                        xmit = true;
@@ -652,6 +722,7 @@ void tipc_link_reset(struct tipc_link *l)
        l->silent_intv_cnt = 0;
        l->stats.recv_info = 0;
        l->stale_count = 0;
+       l->bc_peer_is_up = false;
        link_reset_statistics(l);
 }
 
@@ -673,7 +744,7 @@ int __tipc_link_xmit(struct net *net, struct tipc_link *link,
        uint mtu = link->mtu;
        u16 ack = mod(link->rcv_nxt - 1);
        u16 seqno = link->snd_nxt;
-       u16 bc_last_in = link->owner->bclink.last_in;
+       u16 bc_ack = link->bc_rcvlink->rcv_nxt - 1;
        struct tipc_media_addr *addr = link->media_addr;
        struct sk_buff_head *transmq = &link->transmq;
        struct sk_buff_head *backlogq = &link->backlogq;
@@ -693,7 +764,7 @@ int __tipc_link_xmit(struct net *net, struct tipc_link *link,
                msg = buf_msg(skb);
                msg_set_seqno(msg, seqno);
                msg_set_ack(msg, ack);
-               msg_set_bcast_ack(msg, bc_last_in);
+               msg_set_bcast_ack(msg, bc_ack);
 
                if (likely(skb_queue_len(transmq) < maxwin)) {
                        __skb_dequeue(list);
@@ -743,7 +814,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
        unsigned int mtu = l->mtu;
        u16 ack = l->rcv_nxt - 1;
        u16 seqno = l->snd_nxt;
-       u16 bc_last_in = l->owner->bclink.last_in;
+       u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
        struct sk_buff_head *transmq = &l->transmq;
        struct sk_buff_head *backlogq = &l->backlogq;
        struct sk_buff *skb, *_skb, *bskb;
@@ -762,7 +833,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
                hdr = buf_msg(skb);
                msg_set_seqno(hdr, seqno);
                msg_set_ack(hdr, ack);
-               msg_set_bcast_ack(hdr, bc_last_in);
+               msg_set_bcast_ack(hdr, bc_ack);
 
                if (likely(skb_queue_len(transmq) < maxwin)) {
                        _skb = skb_clone(skb, GFP_ATOMIC);
@@ -796,23 +867,6 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
        return 0;
 }
 
-/*
- * tipc_link_sync_rcv - synchronize broadcast link endpoints.
- * Receive the sequence number where we should start receiving and
- * acking broadcast packets from a newly added peer node, and open
- * up for reception of such packets.
- *
- * Called with node locked
- */
-static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
-{
-       struct tipc_msg *msg = buf_msg(buf);
-
-       n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
-       n->bclink.recv_permitted = true;
-       kfree_skb(buf);
-}
-
 /*
  * tipc_link_push_packets - push unsent packets to bearer
  *
@@ -838,10 +892,10 @@ void tipc_link_push_packets(struct tipc_link *link)
                msg_set_ack(msg, ack);
                msg_set_seqno(msg, seqno);
                seqno = mod(seqno + 1);
-               msg_set_bcast_ack(msg, link->owner->bclink.last_in);
+               /* msg_set_bcast_ack(msg, link->owner->bclink.last_in); */
                link->rcv_unacked = 0;
                __skb_queue_tail(&link->transmq, skb);
-               tipc_bearer_send(link->owner->net, link->bearer_id,
+               tipc_bearer_send(link->net, link->bearer_id,
                                 skb, link->media_addr);
        }
        link->snd_nxt = seqno;
@@ -853,6 +907,7 @@ void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
        struct tipc_msg *hdr;
        u16 seqno = l->snd_nxt;
        u16 ack = l->rcv_nxt - 1;
+       u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 
        while (skb_queue_len(&l->transmq) < l->window) {
                skb = skb_peek(&l->backlogq);
@@ -867,55 +922,25 @@ void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
                __skb_queue_tail(&l->transmq, skb);
                __skb_queue_tail(xmitq, _skb);
                TIPC_SKB_CB(skb)->ackers = l->ackers;
-               msg_set_ack(hdr, ack);
                msg_set_seqno(hdr, seqno);
-               msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
+               msg_set_ack(hdr, ack);
+               msg_set_bcast_ack(hdr, bc_ack);
                l->rcv_unacked = 0;
                seqno++;
        }
        l->snd_nxt = seqno;
 }
 
-static void link_retransmit_failure(struct tipc_link *l_ptr,
-                                   struct sk_buff *buf)
+static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
 {
-       struct tipc_msg *msg = buf_msg(buf);
-       struct net *net = l_ptr->owner->net;
-
-       pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
+       struct tipc_msg *hdr = buf_msg(skb);
 
-       if (l_ptr->addr) {
-               /* Handle failure on standard link */
-               link_print(l_ptr, "Resetting link ");
-               pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
-                       msg_user(msg), msg_type(msg), msg_size(msg),
-                       msg_errcode(msg));
-               pr_info("sqno %u, prev: %x, src: %x\n",
-                       msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
-       } else {
-               /* Handle failure on broadcast link */
-               struct tipc_node *n_ptr;
-               char addr_string[16];
-
-               pr_info("Msg seq number: %u,  ", msg_seqno(msg));
-               pr_cont("Outstanding acks: %lu\n",
-                       (unsigned long) TIPC_SKB_CB(buf)->handle);
-
-               n_ptr = tipc_bclink_retransmit_to(net);
-
-               tipc_addr_string_fill(addr_string, n_ptr->addr);
-               pr_info("Broadcast link info for %s\n", addr_string);
-               pr_info("Reception permitted: %d,  Acked: %u\n",
-                       n_ptr->bclink.recv_permitted,
-                       n_ptr->bclink.acked);
-               pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
-                       n_ptr->bclink.last_in,
-                       n_ptr->bclink.oos_state,
-                       n_ptr->bclink.last_sent);
-
-               n_ptr->action_flags |= TIPC_BCAST_RESET;
-               l_ptr->stale_count = 0;
-       }
+       pr_warn("Retransmission failure on link <%s>\n", l->name);
+       link_print(l, "Resetting link ");
+       pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
+               msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
+       pr_info("sqno %u, prev: %x, src: %x\n",
+               msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
 }
 
 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
@@ -944,8 +969,8 @@ void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
                        break;
                msg = buf_msg(skb);
                msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
-               msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
-               tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
+               /* msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); */
+               tipc_bearer_send(l_ptr->net, l_ptr->bearer_id, skb,
                                 l_ptr->media_addr);
                retransmits--;
                l_ptr->stats.retransmitted++;
@@ -958,7 +983,7 @@ int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
        struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
        struct tipc_msg *hdr;
        u16 ack = l->rcv_nxt - 1;
-       u16 bc_ack = l->owner->bclink.last_in;
+       u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 
        if (!skb)
                return 0;
@@ -1000,11 +1025,9 @@ int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
  * Consumes buffer if message is of right type
  * Node lock must be held
  */
-static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
+static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
                            struct sk_buff_head *inputq)
 {
-       struct tipc_node *node = link->owner;
-
        switch (msg_user(buf_msg(skb))) {
        case TIPC_LOW_IMPORTANCE:
        case TIPC_MEDIUM_IMPORTANCE:
@@ -1014,8 +1037,8 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
                skb_queue_tail(inputq, skb);
                return true;
        case NAME_DISTRIBUTOR:
-               node->bclink.recv_permitted = true;
-               skb_queue_tail(link->namedq, skb);
+               l->bc_rcvlink->state = LINK_ESTABLISHED;
+               skb_queue_tail(l->namedq, skb);
                return true;
        case MSG_BUNDLER:
        case TUNNEL_PROTOCOL:
@@ -1036,7 +1059,6 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
                           struct sk_buff_head *inputq)
 {
-       struct tipc_node *node = l->owner;
        struct tipc_msg *hdr = buf_msg(skb);
        struct sk_buff **reasm_skb = &l->reasm_buf;
        struct sk_buff *iskb;
@@ -1077,13 +1099,15 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
                if (tipc_buf_append(reasm_skb, &skb)) {
                        l->stats.recv_fragmented++;
                        tipc_data_input(l, skb, inputq);
-               } else if (!*reasm_skb) {
+               } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
+                       pr_warn_ratelimited("Unable to build fragment list\n");
                        return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
                }
                return 0;
        } else if (usr == BCAST_PROTOCOL) {
-               tipc_link_sync_rcv(node, skb);
-               return 0;
+               tipc_bcast_lock(l->net);
+               tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
+               tipc_bcast_unlock(l->net);
        }
 drop:
        kfree_skb(skb);
@@ -1106,12 +1130,28 @@ static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
 }
 
 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
+ *
+ * Note that sending of broadcast ack is coordinated among nodes, to reduce
+ * risk of ack storms towards the sender
  */
-void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
+int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
 {
+       if (!l)
+               return 0;
+
+       /* Broadcast ACK must be sent via a unicast link => defer to caller */
+       if (link_is_bc_rcvlink(l)) {
+               if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf)
+                       return 0;
+               l->rcv_unacked = 0;
+               return TIPC_LINK_SND_BC_ACK;
+       }
+
+       /* Unicast ACK */
        l->rcv_unacked = 0;
        l->stats.sent_acks++;
        tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
+       return 0;
 }
 
 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
@@ -1133,6 +1173,9 @@ static void tipc_link_build_nack_msg(struct tipc_link *l,
 {
        u32 def_cnt = ++l->stats.deferred_recv;
 
+       if (link_is_bc_rcvlink(l))
+               return;
+
        if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
                tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
 }
@@ -1193,12 +1236,11 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                l->rcv_nxt++;
                l->stats.recv_info++;
                if (!tipc_data_input(l, skb, l->inputq))
-                       rc = tipc_link_input(l, skb, l->inputq);
-               if (unlikely(rc))
-                       break;
+                       rc |= tipc_link_input(l, skb, l->inputq);
                if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
-                       tipc_link_build_ack_msg(l, xmitq);
-
+                       rc |= tipc_link_build_ack_msg(l, xmitq);
+               if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
+                       break;
        } while ((skb = __skb_dequeue(defq)));
 
        return rc;
@@ -1261,23 +1303,17 @@ void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
        skb = __skb_dequeue(&xmitq);
        if (!skb)
                return;
-       tipc_bearer_send(l->owner->net, l->bearer_id, skb, l->media_addr);
+       tipc_bearer_xmit_skb(l->net, l->bearer_id, skb, l->media_addr);
        l->rcv_unacked = 0;
-       kfree_skb(skb);
 }
 
-/* tipc_link_build_proto_msg: prepare link protocol message for transmission
- */
 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 sk_buff *skb = NULL;
        struct tipc_msg *hdr = l->pmsg;
-       u16 snd_nxt = l->snd_nxt;
-       u16 rcv_nxt = l->rcv_nxt;
-       u16 rcv_last = rcv_nxt - 1;
-       int node_up = l->owner->bclink.recv_permitted;
+       bool node_up = link_is_up(l->bc_rcvlink);
 
        /* Don't send protocol message during reset or link failover */
        if (tipc_link_is_blocked(l))
@@ -1285,33 +1321,34 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 
        msg_set_type(hdr, mtyp);
        msg_set_net_plane(hdr, l->net_plane);
-       msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
-       msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
+       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_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
        msg_set_link_tolerance(hdr, tolerance);
        msg_set_linkprio(hdr, priority);
        msg_set_redundant_link(hdr, node_up);
        msg_set_seq_gap(hdr, 0);
 
        /* Compatibility: created msg must not be in sequence with pkt flow */
-       msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
+       msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
 
        if (mtyp == STATE_MSG) {
                if (!tipc_link_is_up(l))
                        return;
-               msg_set_next_sent(hdr, snd_nxt);
 
                /* Override rcvgap if there are packets in deferred queue */
                if (!skb_queue_empty(&l->deferdq))
-                       rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
+                       rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
                if (rcvgap) {
                        msg_set_seq_gap(hdr, rcvgap);
                        l->stats.sent_nacks++;
                }
-               msg_set_ack(hdr, rcv_last);
                msg_set_probe(hdr, probe);
                if (probe)
                        l->stats.sent_probes++;
                l->stats.sent_states++;
+               l->rcv_unacked = 0;
        } else {
                /* RESET_MSG or ACTIVATE_MSG */
                msg_set_max_pkt(hdr, l->advertised_mtu);
@@ -1413,7 +1450,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
        char *if_name;
        int rc = 0;
 
-       if (tipc_link_is_blocked(l))
+       if (tipc_link_is_blocked(l) || !xmitq)
                goto exit;
 
        if (link_own_addr(l) > msg_prevnode(hdr))
@@ -1500,6 +1537,188 @@ exit:
        return rc;
 }
 
+/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
+ */
+static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
+                                        u16 peers_snd_nxt,
+                                        struct sk_buff_head *xmitq)
+{
+       struct sk_buff *skb;
+       struct tipc_msg *hdr;
+       struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
+       u16 ack = l->rcv_nxt - 1;
+       u16 gap_to = peers_snd_nxt - 1;
+
+       skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
+                             0, l->addr, link_own_addr(l), 0, 0, 0);
+       if (!skb)
+               return false;
+       hdr = buf_msg(skb);
+       msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
+       msg_set_bcast_ack(hdr, ack);
+       msg_set_bcgap_after(hdr, ack);
+       if (dfrd_skb)
+               gap_to = buf_seqno(dfrd_skb) - 1;
+       msg_set_bcgap_to(hdr, gap_to);
+       msg_set_non_seq(hdr, bcast);
+       __skb_queue_tail(xmitq, skb);
+       return true;
+}
+
+/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
+ *
+ * Give a newly added peer node the sequence number where it should
+ * start receiving and acking broadcast packets.
+ */
+void tipc_link_build_bc_init_msg(struct tipc_link *l,
+                                struct sk_buff_head *xmitq)
+{
+       struct sk_buff_head list;
+
+       __skb_queue_head_init(&list);
+       if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
+               return;
+       tipc_link_xmit(l, &list, xmitq);
+}
+
+/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
+ */
+void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
+{
+       int mtyp = msg_type(hdr);
+       u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
+
+       if (link_is_up(l))
+               return;
+
+       if (msg_user(hdr) == BCAST_PROTOCOL) {
+               l->rcv_nxt = peers_snd_nxt;
+               l->state = LINK_ESTABLISHED;
+               return;
+       }
+
+       if (l->peer_caps & TIPC_BCAST_SYNCH)
+               return;
+
+       if (msg_peer_node_is_up(hdr))
+               return;
+
+       /* Compatibility: accept older, less safe initial synch data */
+       if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
+               l->rcv_nxt = peers_snd_nxt;
+}
+
+/* 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)
+{
+       u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
+
+       if (!link_is_up(l))
+               return;
+
+       if (!msg_peer_node_is_up(hdr))
+               return;
+
+       l->bc_peer_is_up = true;
+
+       /* Ignore if peers_snd_nxt goes beyond receive window */
+       if (more(peers_snd_nxt, l->rcv_nxt + l->window))
+               return;
+
+       if (!more(peers_snd_nxt, l->rcv_nxt)) {
+               l->nack_state = BC_NACK_SND_CONDITIONAL;
+               return;
+       }
+
+       /* 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;
+       }
+
+       /* 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;
+       }
+
+       /* 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;
+}
+
+void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
+                         struct sk_buff_head *xmitq)
+{
+       struct sk_buff *skb, *tmp;
+       struct tipc_link *snd_l = l->bc_sndlink;
+
+       if (!link_is_up(l) || !l->bc_peer_is_up)
+               return;
+
+       if (!more(acked, l->acked))
+               return;
+
+       /* Skip over packets peer has already acked */
+       skb_queue_walk(&snd_l->transmq, skb) {
+               if (more(buf_seqno(skb), l->acked))
+                       break;
+       }
+
+       /* Update/release the packets peer is acking now */
+       skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
+               if (more(buf_seqno(skb), acked))
+                       break;
+               if (!--TIPC_SKB_CB(skb)->ackers) {
+                       __skb_unlink(skb, &snd_l->transmq);
+                       kfree_skb(skb);
+               }
+       }
+       l->acked = acked;
+       tipc_link_advance_backlog(snd_l, xmitq);
+       if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
+               link_prepare_wakeup(snd_l);
+}
+
+/* tipc_link_bc_nack_rcv(): receive broadcast nack message
+ */
+int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
+                         struct sk_buff_head *xmitq)
+{
+       struct tipc_msg *hdr = buf_msg(skb);
+       u32 dnode = msg_destnode(hdr);
+       int mtyp = msg_type(hdr);
+       u16 acked = msg_bcast_ack(hdr);
+       u16 from = acked + 1;
+       u16 to = msg_bcgap_to(hdr);
+       u16 peers_snd_nxt = to + 1;
+       int rc = 0;
+
+       kfree_skb(skb);
+
+       if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
+               return 0;
+
+       if (mtyp != STATE_MSG)
+               return 0;
+
+       if (dnode == link_own_addr(l)) {
+               tipc_link_bc_ack_rcv(l, acked, xmitq);
+               rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
+               l->stats.recv_nacks++;
+               return rc;
+       }
+
+       /* Msg for other node => suppress own NACK at next sync if applicable */
+       if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
+               l->nack_state = BC_NACK_SND_SUPPRESS;
+
+       return 0;
+}
+
 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
 {
        int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
@@ -1788,7 +2007,7 @@ static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
        if (tipc_link_is_up(link))
                if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
                        goto attr_msg_full;
-       if (tipc_link_is_active(link))
+       if (link->active)
                if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
                        goto attr_msg_full;