[DCCP]: Fix the ACK and SEQ window variables settings

This is from a first audit, more eyeballs are more than welcome.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 41 insertions, 10 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index aab72b8d070..33968a9422f 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -340,13 +340,11 @@ static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-	u64 tmp_gsr;
 
-	dccp_set_seqno(&tmp_gsr,
+	dp->dccps_gsr = seq;
+	dccp_set_seqno(&dp->dccps_swl,
 		       (dp->dccps_gsr + 1 -
 		        (dp->dccps_options.dccpo_sequence_window / 4)));
-	dp->dccps_gsr = seq;
-	dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
 	dccp_set_seqno(&dp->dccps_swh,
 		       (dp->dccps_gsr +
 			(3 * dp->dccps_options.dccpo_sequence_window) / 4));
@@ -355,13 +353,11 @@ static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-	u64 tmp_gss;
 
-	dccp_set_seqno(&tmp_gss,
+	dp->dccps_awh = dp->dccps_gss = seq;
+	dccp_set_seqno(&dp->dccps_awl,
 		       (dp->dccps_gss -
 			dp->dccps_options.dccpo_sequence_window + 1));
-	dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
-	dp->dccps_awh = dp->dccps_gss = seq;
 }
 
 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
diff --git a/net/dccp/input.c b/net/dccp/input.c
index ce8396b126d..5847cf454e2 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -314,7 +314,19 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 		}
 
 		dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
-		dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+		dccp_update_gsr(sk, dp->dccps_isr);
+		/*
+		 * SWL and AWL are initially adjusted so that they are not less than
+		 * the initial Sequence Numbers received and sent, respectively:
+		 *	SWL := max(GSR + 1 - floor(W/4), ISR),
+		 *	AWL := max(GSS - W' + 1, ISS).
+		 * These adjustments MUST be applied only at the beginning of the
+		 * connection.
+		 *
+		 * AWL was adjusted in dccp_v4_connect -acme
+		 */
+		dccp_set_seqno(&dp->dccps_swl,
+			       max48(dp->dccps_swl, dp->dccps_isr));
 
 		if (ccid_hc_rx_init(dp->dccps_hc_rx_ccid, sk) != 0 ||
 		    ccid_hc_tx_init(dp->dccps_hc_tx_ccid, sk) != 0) {
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 02ebf1f39f3..647e669a126 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -309,6 +309,16 @@ static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 							    usin->sin_port);
 	dccp_update_gss(sk, dp->dccps_iss);
 
+	/*
+	 * SWL and AWL are initially adjusted so that they are not less than
+	 * the initial Sequence Numbers received and sent, respectively:
+	 *	SWL := max(GSR + 1 - floor(W/4), ISR),
+	 *	AWL := max(GSS - W' + 1, ISS).
+	 * These adjustments MUST be applied only at the beginning of the
+	 * connection.
+	 */
+	dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
+
 	inet->id = dp->dccps_iss ^ jiffies;
 
 	err = dccp_connect(sk);
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index b8e67207e97..ce5dff4ac22 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -146,6 +146,19 @@ out_free:
 		newdp->dccps_iss = dreq->dreq_iss;
 		dccp_update_gss(newsk, dreq->dreq_iss);
 
+		/*
+		 * SWL and AWL are initially adjusted so that they are not less than
+		 * the initial Sequence Numbers received and sent, respectively:
+		 *	SWL := max(GSR + 1 - floor(W/4), ISR),
+		 *	AWL := max(GSS - W' + 1, ISS).
+		 * These adjustments MUST be applied only at the beginning of the
+		 * connection.
+		 */
+		dccp_set_seqno(&newdp->dccps_swl,
+			       max48(newdp->dccps_swl, newdp->dccps_isr));
+		dccp_set_seqno(&newdp->dccps_awl,
+			       max48(newdp->dccps_awl, newdp->dccps_iss));
+
 		dccp_init_xmit_timers(newsk);
 
 		DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index 47b1616e618..aa34b576e22 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -144,7 +144,7 @@ static void dccp_retransmit_timer(struct sock *sk)
 	/*
 	 * sk->sk_send_head has to have one skb with
 	 * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
-	 * packet types (REQUEST, RESPONSE, the ACK in the 3way hanshake
+	 * packet types (REQUEST, RESPONSE, the ACK in the 3way handshake
 	 * (PARTOPEN timer), etc).
 	 */
 	BUG_TRAP(sk->sk_send_head != NULL);