diff --git a/net/tipc/link.c b/net/tipc/link.c index 58bb44d95f95..b36e16cdc945 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -242,8 +242,8 @@ 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); static void link_print(struct tipc_link *l, const char *str); -static void tipc_link_build_nack_msg(struct tipc_link *l, - struct sk_buff_head *xmitq); +static int 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); @@ -1184,17 +1184,26 @@ void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq) } /* tipc_link_build_nack_msg: prepare link nack message for transmission + * Note that sending of broadcast NACK is coordinated among nodes, to + * reduce the risk of NACK storms towards the sender */ -static void tipc_link_build_nack_msg(struct tipc_link *l, - struct sk_buff_head *xmitq) +static int tipc_link_build_nack_msg(struct tipc_link *l, + struct sk_buff_head *xmitq) { u32 def_cnt = ++l->stats.deferred_recv; + int match1, match2; - if (link_is_bc_rcvlink(l)) - return; + if (link_is_bc_rcvlink(l)) { + match1 = def_cnt & 0xf; + match2 = tipc_own_addr(l->net) & 0xf; + if (match1 == match2) + return TIPC_LINK_SND_STATE; + return 0; + } 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); + return 0; } /* tipc_link_rcv - process TIPC packets/messages arriving from off-node @@ -1245,7 +1254,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, /* Defer delivery if sequence gap */ if (unlikely(seqno != rcv_nxt)) { __tipc_skb_queue_sorted(defq, seqno, skb); - tipc_link_build_nack_msg(l, xmitq); + rc |= tipc_link_build_nack_msg(l, xmitq); break; }