[DCCP]: Introduce dccp_write_xmit from code in dccp_sendmsg

This way it gets closer to the TCP flow, where congestion window
checks are done, it seems we can map ccid_hc_tx_send_packet in
dccp_write_xmit to tcp_snd_wnd_test in tcp_write_xmit, a CCID2
decision should just fit in here as well...
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/ccid.h

@@ -43,8 +43,7 @@ struct ccid {
 						    unsigned char len, u16 idx,
 						    unsigned char* value);
 	int		(*ccid_hc_tx_send_packet)(struct sock *sk,
-						  struct sk_buff *skb, int len,
-						  long *delay);
+						  struct sk_buff *skb, int len);
 	void		(*ccid_hc_tx_packet_sent)(struct sock *sk, int more, int len);
 };
 
@@ -60,12 +59,11 @@ static inline void __ccid_get(struct ccid *ccid)
 }
 
 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
-					 struct sk_buff *skb, int len,
-					 long *delay)
+					 struct sk_buff *skb, int len)
 {
 	int rc = 0;
 	if (ccid->ccid_hc_tx_send_packet != NULL)
-		rc = ccid->ccid_hc_tx_send_packet(sk, skb, len, delay);
+		rc = ccid->ccid_hc_tx_send_packet(sk, skb, len);
 	return rc;
 }
 

net/dccp/ccids/ccid3.c

@@ -977,13 +977,14 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 	sock_put(sk);
 }
 
-static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb,
-				   int len, long *delay)
+static int ccid3_hc_tx_send_packet(struct sock *sk,
+				   struct sk_buff *skb, int len)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
 	struct ccid3_tx_hist_entry *new_packet = NULL;
 	struct timeval now;
+	long delay;
 	int rc = -ENOTCONN;
 
 //	ccid3_pr_debug("%s, sk=%p, skb=%p, len=%d\n", dccp_role(sk), sk, skb, len);
@@ -1037,11 +1038,11 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb,
 		break;
 	case TFRC_SSTATE_NO_FBACK:
 	case TFRC_SSTATE_FBACK:
-		*delay = (now_delta(hctx->ccid3hctx_t_nom) - hctx->ccid3hctx_delta);
-		ccid3_pr_debug("send_packet delay=%ld\n",*delay);
-		*delay /= -1000;
+		delay = (now_delta(hctx->ccid3hctx_t_nom) - hctx->ccid3hctx_delta);
+		ccid3_pr_debug("send_packet delay=%ld\n", delay);
+		delay /= -1000;
 		/* divide by -1000 is to convert to ms and get sign right */
-		rc = *delay > 0 ? -EAGAIN : 0;
+		rc = delay > 0 ? -EAGAIN : 0;
 		break;
 	default:
 		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",

net/dccp/dccp.h

@@ -122,6 +122,9 @@ extern void dccp_send_ack(struct sock *sk);
 extern void dccp_send_delayed_ack(struct sock *sk);
 extern void dccp_send_sync(struct sock *sk, u64 seq);
 
+extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
+			   const int len);
+
 extern void dccp_init_xmit_timers(struct sock *sk);
 static inline void dccp_clear_xmit_timers(struct sock *sk)
 {
@@ -194,8 +197,6 @@ static inline void dccp_openreq_init(struct request_sock *req,
 	req->rcv_wnd = 0;
 }
 
-extern void dccp_v4_send_check(struct sock *sk, struct dccp_hdr *dh, int len, 
-			       struct sk_buff *skb);
 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 
 extern struct sock *dccp_create_openreq_child(struct sock *sk,

net/dccp/output.c

@@ -148,6 +148,41 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
 	return mss_now;
 }
 
+int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, const int len)
+{
+	const struct dccp_sock *dp = dccp_sk(sk);
+	int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, len);
+
+	if (err == 0) {
+		const struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
+		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
+
+		if (sk->sk_state == DCCP_PARTOPEN) {
+			/* See 8.1.5.  Handshake Completion */
+			inet_csk_schedule_ack(sk);
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+						  inet_csk(sk)->icsk_rto,
+						  DCCP_RTO_MAX);
+			dcb->dccpd_type = DCCP_PKT_DATAACK;
+			/*
+			 * FIXME: we really should have a
+			 * dccps_ack_pending or use icsk.
+			 */
+		} else if (inet_csk_ack_scheduled(sk) ||
+			   (dp->dccps_options.dccpo_send_ack_vector &&
+			    ap->dccpap_buf_ackno != DCCP_MAX_SEQNO + 1 &&
+			    ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1))
+			dcb->dccpd_type = DCCP_PKT_DATAACK;
+		else
+			dcb->dccpd_type = DCCP_PKT_DATA;
+
+		err = dccp_transmit_skb(sk, skb);
+		ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
+	}
+
+	return err;
+}
+
 int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 {
 	if (inet_sk_rebuild_header(sk) != 0)
@@ -299,7 +334,8 @@ int dccp_connect(struct sock *sk)
 	DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
 
 	/* Timer for repeating the REQUEST until an answer. */
-	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX);
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+				  icsk->icsk_rto, DCCP_RTO_MAX);
 	return 0;
 }
 

net/dccp/proto.c

@@ -182,8 +182,7 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		return -EMSGSIZE;
 
 	lock_sock(sk);
-
-	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+	timeo = sock_sndtimeo(sk, noblock);
 
 	/*
 	 * We have to use sk_stream_wait_connect here to set sk_write_pending,
@@ -192,77 +191,27 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	/* Wait for a connection to finish. */
 	if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
 		if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
-			goto out_err;
+			goto out_release;
 
 	size = sk->sk_prot->max_header + len;
 	release_sock(sk);
 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 	lock_sock(sk);
-
 	if (skb == NULL)
 		goto out_release;
 
 	skb_reserve(skb, sk->sk_prot->max_header);
 	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
-	if (rc == 0) {
-		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
-		const struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
-		long delay; 
-
-		/*
-		 * XXX: This is just to match the Waikato tree CA interaction
-		 * points, after the CCID3 code is stable and I have a better
-		 * understanding of behaviour I'll change this to look more like
-		 * TCP.
-		 */
-		while (1) {
-			rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk,
-						    skb, len, &delay);
-			if (rc == 0)
-				break;
-			if (rc != -EAGAIN)
-				goto out_discard;
-			if (delay > timeo)
-				goto out_discard;
-			release_sock(sk);
-			delay = schedule_timeout(delay);
-			lock_sock(sk);
-			timeo -= delay;
-			if (signal_pending(current))
-				goto out_interrupted;
-			rc = -EPIPE;
-			if (!(sk->sk_state == DCCP_PARTOPEN || sk->sk_state == DCCP_OPEN))
+	if (rc != 0)
 		goto out_discard;
-		}
 
-		if (sk->sk_state == DCCP_PARTOPEN) {
-			/* See 8.1.5.  Handshake Completion */
-			inet_csk_schedule_ack(sk);
-			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
-			dcb->dccpd_type = DCCP_PKT_DATAACK;
-			/* FIXME: we really should have a dccps_ack_pending or use icsk */
-		} else if (inet_csk_ack_scheduled(sk) ||
-			   (dp->dccps_options.dccpo_send_ack_vector &&
-			    ap->dccpap_buf_ackno != DCCP_MAX_SEQNO + 1 &&
-			    ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1))
-			dcb->dccpd_type = DCCP_PKT_DATAACK;
-		else
-			dcb->dccpd_type = DCCP_PKT_DATA;
-		dccp_transmit_skb(sk, skb);
-		ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
-	} else {
-out_discard:
-		kfree_skb(skb);
-	}
+	rc = dccp_write_xmit(sk, skb, len);
 out_release:
 	release_sock(sk);
 	return rc ? : len;
-out_err:
-	rc = sk_stream_error(sk, flags, rc);
+out_discard:
+	kfree_skb(skb);
 	goto out_release;
-out_interrupted:
-	rc = sock_intr_errno(timeo);
-	goto out_discard;
 }
 
 EXPORT_SYMBOL(dccp_sendmsg);