[DCCP]: Send SYNCACK packets in response to SYNC packets
Also fix step 6 when receiving SYNC or SYNCACK packets, i.e. we were not using
the updated swl.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 9dadfc3..68b6e72 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -50,7 +50,7 @@
* Drop packet and return
*/
if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
- dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+ dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
return;
}
@@ -76,8 +76,7 @@
{
const struct dccp_hdr *dh = dccp_hdr(skb);
struct dccp_sock *dp = dccp_sk(sk);
- u64 lswl = dp->dccps_swl;
- u64 lawl = dp->dccps_awl;
+ u64 lswl, lawl;
/*
* Step 5: Prepare sequence numbers for Sync
@@ -99,6 +98,8 @@
dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
else
return -1;
+ }
+
/*
* Step 6: Check sequence numbers
* Let LSWL = S.SWL and LAWL = S.AWL
@@ -113,7 +114,10 @@
* Send Sync packet acknowledging P.seqno
* Drop packet and return
*/
- } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
+ lswl = dp->dccps_swl;
+ lawl = dp->dccps_awl;
+
+ if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
dh->dccph_type == DCCP_PKT_CLOSE ||
dh->dccph_type == DCCP_PKT_RESET) {
lswl = dp->dccps_gsr;
@@ -132,8 +136,8 @@
DCCP_PKT_WITHOUT_ACK_SEQ))
dp->dccps_gar = DCCP_SKB_CB(skb)->dccpd_ack_seq;
} else {
- dccp_pr_debug("Step 6 failed, sending SYNC...\n");
- dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+ LIMIT_NETDEBUG("Step 6 failed, sending SYNC...\n");
+ dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
return -1;
}
@@ -242,9 +246,21 @@
check_seq:
if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) {
send_sync:
- dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+ dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+ DCCP_PKT_SYNC);
}
break;
+ case DCCP_PKT_SYNC:
+ dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+ DCCP_PKT_SYNCACK);
+ /*
+ * From the draft:
+ *
+ * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
+ * MAY have non-zero-length application data areas, whose
+ * contents * receivers MUST ignore.
+ */
+ goto discard;
}
DCCP_INC_STATS_BH(DCCP_MIB_INERRS);
@@ -517,7 +533,8 @@
dh->dccph_type == DCCP_PKT_REQUEST) ||
(sk->sk_state == DCCP_RESPOND &&
dh->dccph_type == DCCP_PKT_DATA)) {
- dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+ dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
+ DCCP_PKT_SYNC);
goto discard;
}