1 files changed, 104 insertions, 10 deletions

diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index 5d0842efde69..7f4729234957 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -102,6 +102,8 @@ static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local,
  */
 static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
 {
+	unsigned int max_data;
+
 	/* wind down the local interface MTU */
 	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu)
 		peer->if_mtu = mtu;
@@ -120,11 +122,15 @@ static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
 		}
 	}
 
-	if (mtu < peer->mtu) {
-		spin_lock(&peer->lock);
-		peer->mtu = mtu;
-		peer->maxdata = peer->mtu - peer->hdrsize;
-		spin_unlock(&peer->lock);
+	max_data = max_t(int, mtu - peer->hdrsize, 500);
+	if (max_data < peer->max_data) {
+		if (peer->pmtud_good > max_data)
+			peer->pmtud_good = max_data;
+		if (peer->pmtud_bad > max_data + 1)
+			peer->pmtud_bad = max_data + 1;
+
+		trace_rxrpc_pmtud_reduce(peer, 0, max_data, rxrpc_pmtud_reduce_icmp);
+		peer->max_data = max_data;
 	}
 }
 
@@ -161,6 +167,13 @@ void rxrpc_input_error(struct rxrpc_local *local, struct sk_buff *skb)
 		goto out;
 	}
 
+	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 &&
+	     serr->ee.ee_type == ICMPV6_PKT_TOOBIG &&
+	     serr->ee.ee_code == 0)) {
+		rxrpc_adjust_mtu(peer, serr->ee.ee_info);
+		goto out;
+	}
+
 	rxrpc_store_error(peer, skb);
 out:
 	rxrpc_put_peer(peer, rxrpc_peer_put_input_error);
@@ -205,23 +218,23 @@ static void rxrpc_distribute_error(struct rxrpc_peer *peer, struct sk_buff *skb,
 	struct rxrpc_call *call;
 	HLIST_HEAD(error_targets);
 
-	spin_lock(&peer->lock);
+	spin_lock_irq(&peer->lock);
 	hlist_move_list(&peer->error_targets, &error_targets);
 
 	while (!hlist_empty(&error_targets)) {
 		call = hlist_entry(error_targets.first,
 				   struct rxrpc_call, error_link);
 		hlist_del_init(&call->error_link);
-		spin_unlock(&peer->lock);
+		spin_unlock_irq(&peer->lock);
 
 		rxrpc_see_call(call, rxrpc_call_see_distribute_error);
 		rxrpc_set_call_completion(call, compl, 0, -err);
-		rxrpc_input_call_event(call, skb);
+		rxrpc_input_call_event(call);
 
-		spin_lock(&peer->lock);
+		spin_lock_irq(&peer->lock);
 	}
 
-	spin_unlock(&peer->lock);
+	spin_unlock_irq(&peer->lock);
 }
 
 /*
@@ -347,3 +360,84 @@ void rxrpc_peer_keepalive_worker(struct work_struct *work)
 
 	_leave("");
 }
+
+/*
+ * Do path MTU probing.
+ */
+void rxrpc_input_probe_for_pmtud(struct rxrpc_connection *conn, rxrpc_serial_t acked_serial,
+				 bool sendmsg_fail)
+{
+	struct rxrpc_peer *peer = conn->peer;
+	unsigned int max_data = peer->max_data;
+	int good, trial, bad, jumbo;
+
+	good  = peer->pmtud_good;
+	trial = peer->pmtud_trial;
+	bad   = peer->pmtud_bad;
+	if (good >= bad - 1) {
+		conn->pmtud_probe = 0;
+		peer->pmtud_lost = false;
+		return;
+	}
+
+	if (!peer->pmtud_probing)
+		goto send_probe;
+
+	if (sendmsg_fail || after(acked_serial, conn->pmtud_probe)) {
+		/* Retry a lost probe. */
+		if (!peer->pmtud_lost) {
+			trace_rxrpc_pmtud_lost(conn, acked_serial);
+			conn->pmtud_probe = 0;
+			peer->pmtud_lost = true;
+			goto send_probe;
+		}
+
+		/* The probed size didn't seem to get through. */
+		bad = trial;
+		peer->pmtud_bad = bad;
+		if (bad <= max_data)
+			max_data = bad - 1;
+	} else {
+		/* It did get through. */
+		good = trial;
+		peer->pmtud_good = good;
+		if (good > max_data)
+			max_data = good;
+	}
+
+	max_data = umin(max_data, peer->ackr_max_data);
+	if (max_data != peer->max_data)
+		peer->max_data = max_data;
+
+	jumbo = max_data + sizeof(struct rxrpc_jumbo_header);
+	jumbo /= RXRPC_JUMBO_SUBPKTLEN;
+	peer->pmtud_jumbo = jumbo;
+
+	trace_rxrpc_pmtud_rx(conn, acked_serial);
+	conn->pmtud_probe = 0;
+	peer->pmtud_lost = false;
+
+	if (good < RXRPC_JUMBO(2) && bad > RXRPC_JUMBO(2))
+		trial = RXRPC_JUMBO(2);
+	else if (good < RXRPC_JUMBO(4) && bad > RXRPC_JUMBO(4))
+		trial = RXRPC_JUMBO(4);
+	else if (good < RXRPC_JUMBO(3) && bad > RXRPC_JUMBO(3))
+		trial = RXRPC_JUMBO(3);
+	else if (good < RXRPC_JUMBO(6) && bad > RXRPC_JUMBO(6))
+		trial = RXRPC_JUMBO(6);
+	else if (good < RXRPC_JUMBO(5) && bad > RXRPC_JUMBO(5))
+		trial = RXRPC_JUMBO(5);
+	else if (good < RXRPC_JUMBO(8) && bad > RXRPC_JUMBO(8))
+		trial = RXRPC_JUMBO(8);
+	else if (good < RXRPC_JUMBO(7) && bad > RXRPC_JUMBO(7))
+		trial = RXRPC_JUMBO(7);
+	else
+		trial = (good + bad) / 2;
+	peer->pmtud_trial = trial;
+
+	if (good >= bad)
+		return;
+
+send_probe:
+	peer->pmtud_pending = true;
+}