Example #1
0
int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum)
{
	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb2, *n, *ack = NULL;
	int wakeup = 0;
	int try_retrans = 0;
	unsigned long reftime = cb->stamp;
	unsigned long pkttime;
	unsigned short xmit_count;
	unsigned short segnum;

	skb_queue_walk_safe(q, skb2, n) {
		struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);

		if (dn_before_or_equal(cb2->segnum, acknum))
			ack = skb2;

		

		if (ack == NULL)
			continue;

		

		
		try_retrans = 0;
		
		wakeup = 1;
		
		pkttime = cb2->stamp;
		xmit_count = cb2->xmit_count;
		segnum = cb2->segnum;
		
		skb_unlink(ack, q);
		kfree_skb(ack);
		ack = NULL;

		
		WARN_ON(xmit_count == 0);

		
		if (xmit_count == 1) {
			if (dn_equal(segnum, acknum))
				dn_nsp_rtt(sk, (long)(pkttime - reftime));

			if (scp->snd_window < scp->max_window)
				scp->snd_window++;
		}

		
		if (xmit_count > 1)
			try_retrans = 1;
	}

	if (try_retrans)
		dn_nsp_output(sk);

	return wakeup;
}
Example #2
0
int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum)
{
	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb2, *n, *ack = NULL;
	int wakeup = 0;
	int try_retrans = 0;
	unsigned long reftime = cb->stamp;
	unsigned long pkttime;
	unsigned short xmit_count;
	unsigned short segnum;

	skb_queue_walk_safe(q, skb2, n) {
		struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);

		if (dn_before_or_equal(cb2->segnum, acknum))
			ack = skb2;

		/* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */

		if (ack == NULL)
			continue;

		/* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */

		/* Does _last_ packet acked have xmit_count > 1 */
		try_retrans = 0;
		/* Remember to wake up the sending process */
		wakeup = 1;
		/* Keep various statistics */
		pkttime = cb2->stamp;
		xmit_count = cb2->xmit_count;
		segnum = cb2->segnum;
		/* Remove and drop ack'ed packet */
		skb_unlink(ack, q);
		kfree_skb(ack);
		ack = NULL;

		/*
		 * We don't expect to see acknowledgements for packets we
		 * haven't sent yet.
		 */
		WARN_ON(xmit_count == 0);

		/*
		 * If the packet has only been sent once, we can use it
		 * to calculate the RTT and also open the window a little
		 * further.
		 */
		if (xmit_count == 1) {
			if (dn_equal(segnum, acknum))
				dn_nsp_rtt(sk, (long)(pkttime - reftime));

			if (scp->snd_window < scp->max_window)
				scp->snd_window++;
		}

		/*
		 * Packet has been sent more than once. If this is the last
		 * packet to be acknowledged then we want to send the next
		 * packet in the send queue again (assumes the remote host does
		 * go-back-N error control).
		 */
		if (xmit_count > 1)
			try_retrans = 1;
	}

	if (try_retrans)
		dn_nsp_output(sk);

	return wakeup;
}