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 <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
James Chapman 2013-07-02 20:28:58 +01:00 committed by David S. Miller
parent 8a59bd3e9b
commit b6dc01a43a
1 changed files with 34 additions and 20 deletions

View File

@ -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