tipc: send out RESET immediately when link goes down
[cascardo/linux.git] / net / tipc / link.c
index 75db07c..737b598 100644 (file)
@@ -125,6 +125,11 @@ bool tipc_link_is_reset(struct tipc_link *l)
        return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 }
 
+bool tipc_link_is_establishing(struct tipc_link *l)
+{
+       return l->state == LINK_ESTABLISHING;
+}
+
 bool tipc_link_is_synching(struct tipc_link *l)
 {
        return l->state == LINK_SYNCHING;
@@ -321,14 +326,15 @@ int tipc_link_fsm_evt(struct tipc_link *l, int evt)
                switch (evt) {
                case LINK_ESTABLISH_EVT:
                        l->state = LINK_ESTABLISHED;
-                       rc |= TIPC_LINK_UP_EVT;
                        break;
                case LINK_FAILOVER_BEGIN_EVT:
                        l->state = LINK_FAILINGOVER;
                        break;
-               case LINK_PEER_RESET_EVT:
                case LINK_RESET_EVT:
+                       l->state = LINK_RESET;
+                       break;
                case LINK_FAILURE_EVT:
+               case LINK_PEER_RESET_EVT:
                case LINK_SYNCH_BEGIN_EVT:
                case LINK_FAILOVER_END_EVT:
                        break;
@@ -953,7 +959,7 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
        case TIPC_HIGH_IMPORTANCE:
        case TIPC_CRITICAL_IMPORTANCE:
        case CONN_MANAGER:
-               __skb_queue_tail(inputq, skb);
+               skb_queue_tail(inputq, skb);
                return true;
        case NAME_DISTRIBUTOR:
                node->bclink.recv_permitted = true;
@@ -982,6 +988,7 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
        struct tipc_msg *hdr = buf_msg(skb);
        struct sk_buff **reasm_skb = &l->reasm_buf;
        struct sk_buff *iskb;
+       struct sk_buff_head tmpq;
        int usr = msg_user(hdr);
        int rc = 0;
        int pos = 0;
@@ -1006,10 +1013,12 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
        }
 
        if (usr == MSG_BUNDLER) {
+               skb_queue_head_init(&tmpq);
                l->stats.recv_bundles++;
                l->stats.recv_bundled += msg_msgcnt(hdr);
                while (tipc_msg_extract(skb, &iskb, &pos))
-                       tipc_data_input(l, iskb, inputq);
+                       tipc_data_input(l, iskb, &tmpq);
+               tipc_skb_queue_splice_tail(&tmpq, inputq);
                return 0;
        } else if (usr == MSG_FRAGMENTER) {
                l->stats.recv_fragments++;
@@ -1044,49 +1053,76 @@ static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
        return released;
 }
 
+/* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
+ */
+void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
+{
+       l->rcv_unacked = 0;
+       l->stats.sent_acks++;
+       tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
+}
+
+/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
+ */
+void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
+{
+       int mtyp = RESET_MSG;
+
+       if (l->state == LINK_ESTABLISHING)
+               mtyp = ACTIVATE_MSG;
+
+       tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
+}
+
+/* tipc_link_build_nack_msg: prepare link nack message for transmission
+ */
+static void tipc_link_build_nack_msg(struct tipc_link *l,
+                                    struct sk_buff_head *xmitq)
+{
+       u32 def_cnt = ++l->stats.deferred_recv;
+
+       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);
+}
+
 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
- * @link: the link that should handle the message
+ * @l: the link that should handle the message
  * @skb: TIPC packet
  * @xmitq: queue to place packets to be sent after this call
  */
 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                  struct sk_buff_head *xmitq)
 {
-       struct sk_buff_head *arrvq = &l->deferdq;
-       struct sk_buff_head tmpq;
+       struct sk_buff_head *defq = &l->deferdq;
        struct tipc_msg *hdr;
-       u16 seqno, rcv_nxt;
+       u16 seqno, rcv_nxt, win_lim;
        int rc = 0;
 
-       __skb_queue_head_init(&tmpq);
-
-       if (unlikely(!__tipc_skb_queue_sorted(arrvq, skb))) {
-               if (!(skb_queue_len(arrvq) % TIPC_NACK_INTV))
-                       tipc_link_build_proto_msg(l, STATE_MSG, 0,
-                                                 0, 0, 0, xmitq);
-               return rc;
-       }
-
-       while ((skb = skb_peek(arrvq))) {
+       do {
                hdr = buf_msg(skb);
+               seqno = msg_seqno(hdr);
+               rcv_nxt = l->rcv_nxt;
+               win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
 
                /* Verify and update link state */
-               if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) {
-                       __skb_dequeue(arrvq);
-                       rc = tipc_link_proto_rcv(l, skb, xmitq);
-                       continue;
-               }
+               if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
+                       return tipc_link_proto_rcv(l, skb, xmitq);
 
                if (unlikely(!link_is_up(l))) {
-                       rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-                       if (!link_is_up(l)) {
-                               kfree_skb(__skb_dequeue(arrvq));
-                               goto exit;
-                       }
+                       if (l->state == LINK_ESTABLISHING)
+                               rc = TIPC_LINK_UP_EVT;
+                       goto drop;
                }
 
+               /* Don't send probe at next timeout expiration */
                l->silent_intv_cnt = 0;
 
+               /* Drop if outside receive window */
+               if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
+                       l->stats.duplicates++;
+                       goto drop;
+               }
+
                /* Forward queues and wake up waiting users */
                if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
                        tipc_link_advance_backlog(l, xmitq);
@@ -1094,39 +1130,28 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                                link_prepare_wakeup(l);
                }
 
-               /* Defer reception if there is a gap in the sequence */
-               seqno = msg_seqno(hdr);
-               rcv_nxt = l->rcv_nxt;
-               if (unlikely(less(rcv_nxt, seqno))) {
-                       l->stats.deferred_recv++;
-                       goto exit;
-               }
-
-               __skb_dequeue(arrvq);
-
-               /* Drop if packet already received */
-               if (unlikely(more(rcv_nxt, seqno))) {
-                       l->stats.duplicates++;
-                       kfree_skb(skb);
-                       goto exit;
+               /* Defer delivery if sequence gap */
+               if (unlikely(seqno != rcv_nxt)) {
+                       __tipc_skb_queue_sorted(defq, seqno, skb);
+                       tipc_link_build_nack_msg(l, xmitq);
+                       break;
                }
 
-               /* Packet can be delivered */
+               /* Deliver packet */
                l->rcv_nxt++;
                l->stats.recv_info++;
-               if (unlikely(!tipc_data_input(l, skb, &tmpq)))
-                       rc = tipc_link_input(l, skb, &tmpq);
+               if (!tipc_data_input(l, skb, l->inputq))
+                       rc = tipc_link_input(l, skb, l->inputq);
+               if (unlikely(rc))
+                       break;
+               if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
+                       tipc_link_build_ack_msg(l, xmitq);
+
+       } while ((skb = __skb_dequeue(defq)));
 
-               /* Ack at regular intervals */
-               if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
-                       l->rcv_unacked = 0;
-                       l->stats.sent_acks++;
-                       tipc_link_build_proto_msg(l, STATE_MSG,
-                                                 0, 0, 0, 0, xmitq);
-               }
-       }
-exit:
-       tipc_skb_queue_splice_tail(&tmpq, l->inputq);
+       return rc;
+drop:
+       kfree_skb(skb);
        return rc;
 }
 
@@ -1250,7 +1275,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 }
 
 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
- * with contents of the link's tranmsit and backlog queues.
+ * with contents of the link's transmit and backlog queues.
  */
 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
                           int mtyp, struct sk_buff_head *xmitq)
@@ -1331,6 +1356,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
        u16 peers_tol = msg_link_tolerance(hdr);
        u16 peers_prio = msg_linkprio(hdr);
        u16 rcv_nxt = l->rcv_nxt;
+       int mtyp = msg_type(hdr);
        char *if_name;
        int rc = 0;
 
@@ -1340,7 +1366,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
        if (link_own_addr(l) > msg_prevnode(hdr))
                l->net_plane = msg_net_plane(hdr);
 
-       switch (msg_type(hdr)) {
+       switch (mtyp) {
        case RESET_MSG:
 
                /* Ignore duplicate RESET with old session number */
@@ -1367,12 +1393,14 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
                if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
                        l->priority = peers_prio;
 
-               if (msg_type(hdr) == RESET_MSG) {
-                       rc |= tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
-               } else if (!link_is_up(l)) {
-                       tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
-                       rc |= tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-               }
+               /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
+               if ((mtyp == RESET_MSG) || !link_is_up(l))
+                       rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
+
+               /* ACTIVATE_MSG takes up link if it was already locally reset */
+               if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
+                       rc = TIPC_LINK_UP_EVT;
+
                l->peer_session = msg_session(hdr);
                l->peer_bearer_id = msg_bearer_id(hdr);
                if (l->mtu > msg_max_pkt(hdr))
@@ -1389,9 +1417,12 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
                l->stats.recv_states++;
                if (msg_probe(hdr))
                        l->stats.recv_probes++;
-               rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-               if (!link_is_up(l))
+
+               if (!link_is_up(l)) {
+                       if (l->state == LINK_ESTABLISHING)
+                               rc = TIPC_LINK_UP_EVT;
                        break;
+               }
 
                /* Send NACK if peer has sent pkts we haven't received yet */
                if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))