static void bclink_send_nack(struct tipc_node *n_ptr)
{
struct sk_buff *buf;
struct tipc_msg *msg;
if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
return;
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
msg = buf_msg(buf);
tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
INT_H_SIZE, n_ptr->addr);
msg_set_non_seq(msg, 1);
msg_set_mc_netid(msg, tipc_net_id);
msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in));
msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
msg_set_bcast_tag(msg, tipc_own_tag);
tipc_bearer_send(&bcbearer->bearer, buf, NULL);
bcl->stats.sent_nacks++;
buf_discard(buf);
/*
* Ensure we doesn't send another NACK msg to the node
* until 16 more deferred messages arrive from it
* (i.e. helps prevent all nodes from NACK'ing at same time)
*/
n_ptr->bclink.nack_sync = tipc_own_tag;
}
}
/**
* tipc_bclink_update_link_state - update broadcast link state
*
* tipc_net_lock and node lock set
*/
void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
{
struct sk_buff *buf;
/* Ignore "stale" link state info */
if (less_eq(last_sent, n_ptr->bclink.last_in))
return;
/* Update link synchronization state; quit if in sync */
bclink_update_last_sent(n_ptr, last_sent);
if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
return;
/* Update out-of-sync state; quit if loss is still unconfirmed */
if ((++n_ptr->bclink.oos_state) == 1) {
if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
return;
n_ptr->bclink.oos_state++;
}
/* Don't NACK if one has been recently sent (or seen) */
if (n_ptr->bclink.oos_state & 0x1)
return;
/* Send NACK */
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
struct tipc_msg *msg = buf_msg(buf);
tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
INT_H_SIZE, n_ptr->addr);
msg_set_non_seq(msg, 1);
msg_set_mc_netid(msg, tipc_net_id);
msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
? buf_seqno(n_ptr->bclink.deferred_head) - 1
: n_ptr->bclink.last_sent);
spin_lock_bh(&bc_lock);
tipc_bearer_send(&bcbearer->bearer, buf, NULL);
bcl->stats.sent_nacks++;
spin_unlock_bh(&bc_lock);
kfree_skb(buf);
n_ptr->bclink.oos_state++;
}
}