diff options
| -rw-r--r-- | net/l2tp/l2tp_core.c | 36 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.h | 3 |
2 files changed, 34 insertions, 5 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 735cc06971ef..feae495a0a30 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -572,12 +572,33 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) * reorder queue, in order of ns. */ l2tp_recv_queue_skb(session, skb); + goto out; + } + + /* Packet reordering disabled. Discard out-of-sequence packets, while + * tracking the number if in-sequence packets after the first OOS packet + * is seen. After nr_oos_count_max in-sequence packets, reset the + * sequence number to re-enable packet reception. + */ + if (L2TP_SKB_CB(skb)->ns == session->nr) { + skb_queue_tail(&session->reorder_q, skb); } else { - /* Packet reordering disabled. Discard out-of-sequence - * packets - */ - if ((L2TP_SKB_CB(skb)->ns != session->nr) && - (!session->reorder_skip)) { + u32 nr_oos = L2TP_SKB_CB(skb)->ns; + u32 nr_next = (session->nr_oos + 1) & session->nr_max; + + if (nr_oos == nr_next) + session->nr_oos_count++; + else + session->nr_oos_count = 0; + + session->nr_oos = nr_oos; + if (session->nr_oos_count > session->nr_oos_count_max) { + session->reorder_skip = 1; + l2tp_dbg(session, L2TP_MSG_SEQ, + "%s: %d oos packets received. Resetting sequence numbers\n", + session->name, session->nr_oos_count); + } + if (!session->reorder_skip) { atomic_long_inc(&session->stats.rx_seq_discards); l2tp_dbg(session, L2TP_MSG_SEQ, "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", @@ -589,6 +610,7 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) skb_queue_tail(&session->reorder_q, skb); } +out: return 0; discard: @@ -1852,6 +1874,10 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn else session->nr_max = 0xffffff; session->nr_window_size = session->nr_max / 2; + session->nr_oos_count_max = 4; + + /* Use NR of first received packet */ + session->reorder_skip = 1; sprintf(&session->name[0], "sess %u/%u", tunnel->tunnel_id, session->session_id); diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 4b9a3b724423..66a559b104b6 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -104,6 +104,9 @@ struct l2tp_session { struct sk_buff_head reorder_q; /* receive reorder queue */ u32 nr_max; /* max NR. Depends on tunnel */ u32 nr_window_size; /* NR window size */ + u32 nr_oos; /* NR of last OOS packet */ + int nr_oos_count; /* For OOS recovery */ + int nr_oos_count_max; struct hlist_node hlist; /* Hash list node */ atomic_t ref_count; |