dn_nsp_out.c

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	 * one RTT, then reset window to min size.
	 */
	if ((jiffies - scp->stamp) > t)
		scp->snd_window = NSP_MIN_WINDOW;

	/* printk(KERN_DEBUG "Window: %lu\n", scp->snd_window); */

	cb->xmit_count = 0;

	if (oth)
		skb_queue_tail(&scp->other_xmit_queue, skb);
	else
		skb_queue_tail(&scp->data_xmit_queue, skb);

	if (scp->flowrem_sw != DN_SEND)
		return;

	dn_nsp_clone_and_send(skb, gfp);
}


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, *list, *ack = NULL;
	int wakeup = 0;
	int try_retrans = 0;
	unsigned long reftime = cb->stamp;
	unsigned long pkttime;
	unsigned short xmit_count;
	unsigned short segnum;

	skb2 = q->next;
	list = (struct sk_buff *)q;
	while(list != skb2) {
		struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);

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

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

		skb2 = skb2->next;

		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);
		kfree_skb(ack);
		ack = NULL;

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

void dn_nsp_send_data_ack(struct sock *sk)
{
	struct sk_buff *skb = NULL;

	if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skb, 9);
	dn_mk_ack_header(sk, skb, 0x04, 9, 0);
	dn_nsp_send(skb);
}

void dn_nsp_send_oth_ack(struct sock *sk)
{
	struct sk_buff *skb = NULL;

	if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skb, 9);
	dn_mk_ack_header(sk, skb, 0x14, 9, 1);
	dn_nsp_send(skb);
}


void dn_send_conn_ack (struct sock *sk)
{
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb = NULL;
        struct nsp_conn_ack_msg *msg;

	if ((skb = dn_alloc_skb(sk, 3, sk->allocation)) == NULL)
		return;

        msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
        msg->msgflg = 0x24;                   
	msg->dstaddr = scp->addrrem;

	dn_nsp_send(skb);	
}

void dn_nsp_delayed_ack(struct sock *sk)
{
	struct dn_scp *scp = DN_SK(sk);

	if (scp->ackxmt_oth != scp->numoth_rcv)
		dn_nsp_send_oth_ack(sk);

	if (scp->ackxmt_dat != scp->numdat_rcv)
		dn_nsp_send_data_ack(sk);
}

static int dn_nsp_retrans_conn_conf(struct sock *sk)
{
	struct dn_scp *scp = DN_SK(sk);

	if (scp->state == DN_CC)
		dn_send_conn_conf(sk, GFP_ATOMIC);

	return 0;
}

void dn_send_conn_conf(struct sock *sk, int gfp)
{
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb = NULL;
        struct nsp_conn_init_msg *msg;
	unsigned char len = scp->conndata_out.opt_optl;

	if ((skb = dn_alloc_skb(sk, 50 + scp->conndata_out.opt_optl, gfp)) == NULL)
		return;

        msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg));
        msg->msgflg = 0x28;                   
	msg->dstaddr = scp->addrrem;
        msg->srcaddr = scp->addrloc;
        msg->services = scp->services_loc;
        msg->info = scp->info_loc;
        msg->segsize = dn_htons(scp->segsize_loc);

	*skb_put(skb,1) = len;

	if (len > 0) 
		memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len);
	

	dn_nsp_send(skb);

	scp->persist = dn_nsp_persist(sk);
	scp->persist_fxn = dn_nsp_retrans_conn_conf;
}


static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg, 
			unsigned short reason, int gfp, struct dst_entry *dst,
			int ddl, unsigned char *dd, __u16 rem, __u16 loc)
{
	struct sk_buff *skb = NULL;
	int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0);
	unsigned char *msg;

	if ((dst == NULL) || (rem == 0)) {
		if (net_ratelimit())
			printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to [e-mail] rem=%u dst=%p\n", (unsigned)rem, dst);
		return;
	}

	if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL)
		return;

	msg = skb_put(skb, size);
	*msg++ = msgflg;
	*(__u16 *)msg = rem;
	msg += 2;
	*(__u16 *)msg = loc;
	msg += 2;
	*(__u16 *)msg = dn_htons(reason);
	msg += 2;
	if (msgflg == NSP_DISCINIT)
		*msg++ = ddl;

	if (ddl) {
		memcpy(msg, dd, ddl);
	}

	/*
	 * This doesn't go via the dn_nsp_send() fucntion since we need
	 * to be able to send disc packets out which have no socket
	 * associations.
	 */
	skb->dst = dst_clone(dst);
	skb->dst->output(skb);
}


void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg, 
			unsigned short reason, int gfp)
{
	struct dn_scp *scp = DN_SK(sk);
	int ddl = 0;

	if (msgflg == NSP_DISCINIT)
		ddl = scp->discdata_out.opt_optl;

	if (reason == 0)
		reason = scp->discdata_out.opt_status;

	dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->dst_cache, ddl, 
		scp->discdata_out.opt_data, scp->addrrem, scp->addrloc);
}


void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg, 
			unsigned short reason)
{
	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	int ddl = 0;
	int gfp = GFP_ATOMIC;

	dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl, 
			NULL, cb->src_port, cb->dst_port);
}


void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval)
{
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb;
	unsigned short *segnum;
	unsigned char *ptr;
	int gfp = GFP_ATOMIC;

	if ((skb = dn_alloc_skb(sk, 13, gfp)) == NULL)
		return;

	skb_reserve(skb, 13);
	segnum = dn_mk_ack_header(sk, skb, 0x10, 13, 1);
	*segnum = dn_htons(scp->numoth);
        DN_SKB_CB(skb)->segnum = scp->numoth;
	seq_add(&scp->numoth, 1);
	ptr = (unsigned char *)(segnum + 1);
	*ptr++ = lsflags;
	*ptr = fcval;

	dn_nsp_queue_xmit(sk, skb, gfp, 1);

	scp->persist = dn_nsp_persist(sk);
	scp->persist_fxn = dn_nsp_xmit_timeout;
}

static int dn_nsp_retrans_conninit(struct sock *sk)
{
	struct dn_scp *scp = DN_SK(sk);

	if (scp->state == DN_CI)
		dn_nsp_send_conninit(sk, NSP_RCI);

	return 0;
}

void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
{
	struct dn_scp *scp = DN_SK(sk);
	struct sk_buff *skb = NULL;
	struct nsp_conn_init_msg *msg;
	unsigned char aux;
	unsigned char menuver;
	struct dn_skb_cb *cb;
	unsigned char type = 1;

	if ((skb = dn_alloc_skb(sk, 200, (msgflg == NSP_CI) ? sk->allocation : GFP_ATOMIC)) == NULL)
		return;

	cb  = DN_SKB_CB(skb);
	msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));

	msg->msgflg	= msgflg;
	msg->dstaddr	= 0x0000;		/* Remote Node will assign it*/

	msg->srcaddr	= scp->addrloc;
	msg->services	= scp->services_loc;	/* Requested flow control    */
	msg->info	= scp->info_loc;	/* Version Number            */	
	msg->segsize	= dn_htons(scp->segsize_loc);	/* Max segment size  */	

	if (scp->peer.sdn_objnum)
		type = 0;

	skb_put(skb, dn_sockaddr2username(&scp->peer, skb->tail, type));
	skb_put(skb, dn_sockaddr2username(&scp->addr, skb->tail, 2));

	menuver = DN_MENUVER_ACC | DN_MENUVER_USR;
	if (scp->peer.sdn_flags & SDF_PROXY)
		menuver |= DN_MENUVER_PRX;
	if (scp->peer.sdn_flags & SDF_UICPROXY)
		menuver |= DN_MENUVER_UIC;

	*skb_put(skb, 1) = menuver;	/* Menu Version		*/
	
	aux = scp->accessdata.acc_userl;
	*skb_put(skb, 1) = aux;
	if (aux > 0)
	memcpy(skb_put(skb, aux), scp->accessdata.acc_user, aux);

	aux = scp->accessdata.acc_passl;
	*skb_put(skb, 1) = aux;
	if (aux > 0)
	memcpy(skb_put(skb, aux), scp->accessdata.acc_pass, aux);

	aux = scp->accessdata.acc_accl;
	*skb_put(skb, 1) = aux;
	if (aux > 0)
	memcpy(skb_put(skb, aux), scp->accessdata.acc_acc, aux);

	aux = scp->conndata_out.opt_optl;
	*skb_put(skb, 1) = aux;
	if (aux > 0)
	memcpy(skb_put(skb,aux), scp->conndata_out.opt_data, aux);

	scp->persist = dn_nsp_persist(sk);
	scp->persist_fxn = dn_nsp_retrans_conninit;

	cb->rt_flags = DN_RT_F_RQR;

	dn_nsp_send(skb);	
}