From b6dc01a43aaca24e6e6928e24d9b37ba599f1e3c Mon Sep 17 00:00:00 2001 From: James Chapman Date: Tue, 2 Jul 2013 20:28:58 +0100 Subject: [PATCH] l2tp: do data sequence number handling in a separate func This change moves some code handling data sequence numbers into a separate function to avoid too much indentation. This is to prepare for some changes to data sequence number handling in subsequent patches. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 54 ++++++++++++++++++++++++++++---------------- 1 file changed, 34 insertions(+), 20 deletions(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 6984c3a353cd..5ca29659171d 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -542,6 +542,38 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk, return __skb_checksum_complete(skb); } +/* If packet has sequence numbers, queue it if acceptable. Returns 0 if + * acceptable, else non-zero. + */ +static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) +{ + if (session->reorder_timeout != 0) { + /* Packet reordering enabled. Add skb to session's + * reorder queue, in order of ns. + */ + l2tp_recv_queue_skb(session, skb); + } else { + /* Packet reordering disabled. Discard out-of-sequence + * packets + */ + if (L2TP_SKB_CB(skb)->ns != session->nr) { + 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", + session->name, L2TP_SKB_CB(skb)->ns, + L2TP_SKB_CB(skb)->length, session->nr, + skb_queue_len(&session->reorder_q)); + goto discard; + } + skb_queue_tail(&session->reorder_q, skb); + } + + return 0; + +discard: + return 1; +} + /* Do receive processing of L2TP data frames. We handle both L2TPv2 * and L2TPv3 data frames here. * @@ -757,26 +789,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, * enabled. Saved L2TP protocol info is stored in skb->sb[]. */ if (L2TP_SKB_CB(skb)->has_seq) { - if (session->reorder_timeout != 0) { - /* Packet reordering enabled. Add skb to session's - * reorder queue, in order of ns. - */ - l2tp_recv_queue_skb(session, skb); - } else { - /* Packet reordering disabled. Discard out-of-sequence - * packets - */ - if (L2TP_SKB_CB(skb)->ns != session->nr) { - 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", - session->name, L2TP_SKB_CB(skb)->ns, - L2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); - goto discard; - } - skb_queue_tail(&session->reorder_q, skb); - } + if (l2tp_recv_data_seq(session, skb)) + goto discard; } else { /* No sequence numbers. Add the skb to the tail of the * reorder queue. This ensures that it will be -- 2.39.5