patch-2.3.4 linux/net/decnet/dn_nsp_out.c

• Lines: 641
• Date: Wed May 26 09:36:36 1999
• Orig file: v2.3.3/linux/net/decnet/dn_nsp_out.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.3/linux/net/decnet/dn_nsp_out.c linux/net/decnet/dn_nsp_out.c
@@ -0,0 +1,640 @@
+
+/*
+ * DECnet       An implementation of the DECnet protocol suite for the LINUX
+ *              operating system.  DECnet is implemented using the  BSD Socket
+ *              interface as the means of communication with the user level.
+ *
+ *              DECnet Network Services Protocol (Output)
+ *
+ * Author:      Eduardo Marcelo Serrat <emserrat@geocities.com>
+ *
+ * Changes:
+ *
+ *    Steve Whitehouse:  Split into dn_nsp_in.c and dn_nsp_out.c from
+ *                       original dn_nsp.c.
+ *    Steve Whitehouse:  Updated to work with my new routing architecture.
+ *    Steve Whitehouse:  Added changes from Eduardo Serrat's patches.
+ *    Steve Whitehouse:  Now conninits have the "return" bit set.
+ *    Steve Whitehouse:  Fixes to check alloc'd skbs are non NULL!
+ *                       Moved output state machine into one function
+ *    Steve Whitehouse:  New output state machine
+ */
+
+/******************************************************************************
+    (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
+    
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+*******************************************************************************/
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/inet.h>
+#include <linux/route.h>
+#include <net/sock.h>
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/termios.h>      
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/if_packet.h>
+#include <net/neighbour.h>
+#include <net/dst.h>
+#include <net/dn_nsp.h>
+#include <net/dn_dev.h>
+#include <net/dn_route.h>
+
+
+static int nsp_backoff[NSP_MAXRXTSHIFT + 1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
+
+/*
+ * If sk == NULL, then we assume that we are supposed to be making
+ * a routing layer skb. If sk != NULL, then we are supposed to be
+ * creating an skb for the NSP layer. The dn_send_skb() function will
+ * recognise skbs on the same basis. 
+ *
+ * The eventual aim is for each socket to have a cached header size
+ * for its outgoing packets, and to set hdr from this when sk != NULL.
+ */
+struct sk_buff *dn_alloc_skb(struct sock *sk, int size, int pri)
+{
+	struct sk_buff *skb;
+	int hdr = 64;
+
+	if ((skb = alloc_skb(size + hdr, pri)) == NULL)
+		return NULL;
+
+	skb->protocol = __constant_htons(ETH_P_DNA_RT);
+	skb->sk       = sk;
+	skb->pkt_type = PACKET_OUTGOING;
+
+	skb_reserve(skb, hdr);
+
+	return skb;
+}
+
+/*
+ * Wrapper for the above, for allocs of data skbs. We try and get the
+ * whole size thats been asked for (plus 11 bytes of header). If this
+ * fails, then we try for any size over 16 bytes for SOCK_STREAMS.
+ */
+struct sk_buff *dn_alloc_send_skb(struct sock *sk, int *size, int noblock, int *err)
+{
+	int space;
+	int len;
+	struct sk_buff *skb = NULL;
+
+	*err = 0;
+
+	while(skb == NULL) {
+		if (signal_pending(current)) {
+			*err = ERESTARTSYS;
+			break;
+		}
+
+		if (sk->shutdown & SEND_SHUTDOWN) {
+			*err = EINVAL;
+			break;
+		}
+
+		if (sk->err)
+			break;
+
+		len = *size + 11;
+		space = sk->sndbuf - atomic_read(&sk->wmem_alloc);
+
+		if (space < len) {
+			if ((sk->socket->type == SOCK_STREAM) && (space >= (16 + 11)))
+				len = space;
+		}
+
+		if (space < len) {
+			sk->socket->flags |= SO_NOSPACE;
+			if (noblock) {
+				*err = EWOULDBLOCK;
+				break;
+			}
+
+			sk->socket->flags &= ~SO_NOSPACE;
+			SOCK_SLEEP_PRE(sk)
+
+			if ((sk->sndbuf - atomic_read(&sk->wmem_alloc)) < len)
+				schedule();
+
+			SOCK_SLEEP_POST(sk)
+			continue;
+		}
+
+		if ((skb = dn_alloc_skb(sk, len, GFP_KERNEL)) == NULL)
+			continue;
+
+		skb->destructor = sock_wfree;
+		atomic_add(skb->truesize, &sk->wmem_alloc);
+
+		*size = len - 11;
+	}
+
+	return skb;
+}
+
+/*
+ * Calculate persist timer based upon the smoothed round
+ * trip time and the variance. Backoff according to the
+ * nsp_backoff[] array.
+ */
+unsigned long dn_nsp_persist(struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+
+	unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
+
+	t *= nsp_backoff[scp->nsp_rxtshift];
+
+	if (t < HZ) t = HZ;
+	if (t > (600*HZ)) t = (600*HZ);
+
+	if (scp->nsp_rxtshift < NSP_MAXRXTSHIFT)
+		scp->nsp_rxtshift++;
+
+	/* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */
+
+	return t;
+}
+
+/*
+ * This is called each time we get an estimate for the rtt
+ * on the link.
+ */
+static void dn_nsp_rtt(struct sock *sk, long rtt)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	long srtt = (long)scp->nsp_srtt;
+	long rttvar = (long)scp->nsp_rttvar;
+	long delta;
+
+	/*
+	 * If the jiffies clock flips over in the middle of timestamp
+	 * gathering this value might turn out negative, so we make sure
+	 * that is it always positive here.
+	 */
+	if (rtt < 0) 
+		rtt = -rtt;
+	/*
+	 * Add new rtt to smoothed average
+	 */
+	delta = ((rtt << 3) - srtt);
+	srtt += (delta >> 3);
+	if (srtt >= 1) 
+		scp->nsp_srtt = (unsigned long)srtt;
+	else
+		scp->nsp_srtt = 1;
+
+	/*
+	 * Add new rtt varience to smoothed varience
+	 */
+	delta >>= 1;
+	rttvar += ((((delta>0)?(delta):(-delta)) - rttvar) >> 2);
+	if (rttvar >= 1) 
+		scp->nsp_rttvar = (unsigned long)rttvar;
+	else
+		scp->nsp_rttvar = 1;
+
+	/* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */
+}
+
+/*
+ * Walk the queues, otherdata/linkservice first. Send as many
+ * frames as the window allows, increment send counts on all
+ * skbs which are sent. Reduce the window if we are retransmitting
+ * frames.
+ */
+void dn_nsp_output(struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	unsigned long win = scp->snd_window;
+	struct sk_buff *skb, *skb2, *list;
+	struct dn_skb_cb *cb;
+	int reduce_win = 0;
+
+	/* printk(KERN_DEBUG "dn_nsp_output: ping\n"); */
+
+	/*
+	 * First we check for otherdata/linkservice messages
+	 */
+	skb = scp->other_xmit_queue.next;
+	list = (struct sk_buff *)&scp->other_xmit_queue;
+	while(win && (skb != list)) {
+		if ((skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
+			cb = (struct dn_skb_cb *)skb;
+			if (cb->xmit_count > 0)
+				reduce_win = 1;
+			else
+				cb->stamp = jiffies;
+			cb->xmit_count++;
+			skb2->sk = sk;
+			dn_send_skb(skb2);
+		}
+		skb = skb->next;
+		win--;
+	}
+
+	/*
+	 * If we may not send any data, we don't.
+	 * Should this apply to otherdata as well ? - SJW
+	 */
+	if (scp->flowrem_sw != DN_SEND)
+		goto recalc_window;
+
+	skb = scp->data_xmit_queue.next;
+	list = (struct sk_buff *)&scp->data_xmit_queue;
+	while(win && (skb != list)) {
+		if ((skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
+			cb = (struct dn_skb_cb *)skb;
+			if (cb->xmit_count > 0)
+				reduce_win = 1;
+			else
+				cb->stamp = jiffies;
+			cb->xmit_count++;
+			skb2->sk = sk;
+			dn_send_skb(skb2);
+		}
+		skb = skb->next;
+		win--;
+	}
+
+	/*
+	 * If we've sent any frame more than once, we cut the
+	 * send window size in half. There is always a minimum
+	 * window size of one available.
+	 */
+recalc_window:
+	if (reduce_win) {
+		/* printk(KERN_DEBUG "Window reduction %ld\n", scp->snd_window); */
+		scp->snd_window >>= 1;
+		if (scp->snd_window < NSP_MIN_WINDOW)
+			scp->snd_window = NSP_MIN_WINDOW;
+	}
+}
+
+int dn_nsp_xmit_timeout(struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+
+	dn_nsp_output(sk);
+
+	if (skb_queue_len(&scp->data_xmit_queue) || skb_queue_len(&scp->other_xmit_queue))
+		scp->persist = dn_nsp_persist(sk);
+
+	return 0;
+}
+
+void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, int oth)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb;
+	unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
+	struct sk_buff *skb2;
+
+	if (t < HZ) t = HZ;
+	/*
+	 * Slow start: If we have been idle for more than
+	 * 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;
+
+	if ((skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
+		cb->stamp = jiffies;
+		cb->xmit_count++;
+		skb2->sk = sk;
+		dn_send_skb(skb2);
+	}
+}
+
+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 = (struct dn_skb_cb *)skb->cb;
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct sk_buff *skb2, *list, *ack = NULL;
+	int wakeup = 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 = (struct dn_skb_cb *)skb2->cb;
+
+		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); */
+
+		wakeup = 1;
+		pkttime = cb2->stamp;
+		xmit_count = cb2->xmit_count;
+		segnum = cb2->segnum;
+		skb_unlink(ack);
+		kfree_skb(ack);
+		ack = NULL;
+		if (xmit_count == 1) {
+			if (equal(segnum, acknum)) 
+				dn_nsp_rtt(sk, (long)(pkttime - reftime));
+
+			if (scp->snd_window < NSP_MAX_WINDOW)
+				scp->snd_window++;
+		}
+	}
+
+#if 0 /* Turned off due to possible interference in socket shutdown */
+	if ((skb_queue_len(&scp->data_xmit_queue) == 0) &&
+	    (skb_queue_len(&scp->other_xmit_queue) == 0))
+		scp->persist = 0;
+#endif
+
+	return wakeup;
+}
+
+void dn_nsp_send_data_ack(struct sock *sk)
+{
+	struct	sk_buff			*skb = NULL;
+	struct  nsp_data_ack_msg	*msg;
+
+	if ((skb = dn_alloc_skb(sk, 200, GFP_ATOMIC)) == NULL)
+		return;
+	
+	msg = (struct nsp_data_ack_msg *)skb_put(skb,sizeof(*msg));
+
+	msg->msgflg  = 0x04;			/* data ack message	*/
+	msg->dstaddr = sk->protinfo.dn.addrrem;
+	msg->srcaddr = sk->protinfo.dn.addrloc;
+	msg->acknum  = dn_htons((sk->protinfo.dn.numdat_rcv & 0x0FFF) | 0x8000);
+
+	sk->protinfo.dn.ackxmt_dat = sk->protinfo.dn.numdat_rcv;
+
+	dn_send_skb(skb);
+}
+
+void dn_nsp_send_oth_ack(struct sock *sk)
+{
+	struct	sk_buff			*skb = NULL;
+	struct  nsp_data_ack_msg		*msg;
+
+	if ((skb = dn_alloc_skb(sk, 200, GFP_ATOMIC)) == NULL)
+		return;
+	
+	/* printk(KERN_DEBUG "dn_send_oth_ack\n"); */
+
+	msg = (struct nsp_data_ack_msg *)skb_put(skb,sizeof(*msg));
+
+	msg->msgflg = 0x14;			/* oth ack message	*/
+	msg->dstaddr = sk->protinfo.dn.addrrem;
+	msg->srcaddr = sk->protinfo.dn.addrloc;
+	msg->acknum  = dn_htons((sk->protinfo.dn.numoth_rcv & 0x0FFF) | 0x8000);
+
+	sk->protinfo.dn.ackxmt_oth = sk->protinfo.dn.numoth_rcv;
+
+	dn_send_skb(skb);
+}
+
+
+void dn_send_conn_ack (struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct sk_buff *skb = NULL;
+        struct nsp_conn_ack_msg *msg;
+
+	if ((skb = dn_alloc_skb(sk, 3, GFP_KERNEL)) == NULL)
+		return;
+
+        msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
+        msg->msgflg = 0x24;                   
+	msg->dstaddr = scp->addrrem;
+
+	dn_send_skb(skb);	
+}
+
+void dn_nsp_delayed_ack(struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+
+	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);
+}
+
+void dn_send_conn_conf (struct sock *sk)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct sk_buff *skb = NULL;
+        struct nsp_conn_init_msg *msg;
+	unsigned short int aux;
+
+	if ((skb = dn_alloc_skb(sk, 50 + scp->conndata_out.opt_optl, GFP_KERNEL)) == 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 = 0x01;
+        msg->info = 0x03;
+        msg->segsize = dn_htons(0x05B3);
+
+	if (scp->conndata_out.opt_optl > 0) {
+		aux = scp->conndata_out.opt_optl;
+		*skb_put(skb,1) = aux;
+		memcpy(skb_put(skb, aux), scp->conndata_out.opt_data, aux);
+	}
+	
+
+	dn_send_skb(skb);	
+}
+
+void dn_send_disc (struct sock *sk, unsigned char msgflg, unsigned short reason)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct sk_buff *skb = NULL;
+	int ddl = (msgflg == NSP_DISCINIT || msgflg == 0x38) ? (1 + scp->discdata_out.opt_optl) : 0;
+	int size = 7 + ddl;
+	unsigned char *msg;
+
+	if ((skb = dn_alloc_skb(sk, size, GFP_ATOMIC)) == NULL)
+		return;
+
+	if (reason == 0) reason = scp->discdata_out.opt_status;
+	
+	msg = skb_put(skb, size);
+	*msg++ = msgflg;
+	*(__u16 *)msg = scp->addrrem;
+	msg += 2;
+	*(__u16 *)msg = scp->addrloc;
+	msg += 2;
+	*(__u16 *)msg = dn_htons(reason);
+	msg += 2;
+
+	if (ddl) {
+		*msg++ = scp->discdata_out.opt_optl;
+		memcpy(msg, scp->discdata_out.opt_data, scp->discdata_out.opt_optl);
+	}
+
+	dn_send_skb(skb);	
+}
+
+void dn_nsp_send_lnk(struct sock *sk, unsigned short flgs)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	struct sk_buff *skb = NULL;
+	struct nsp_data_seg_msg	*msg;
+	struct nsp_data_opt_msg	*msg1;
+	struct dn_skb_cb *cb;
+
+	if ((skb = dn_alloc_skb(sk, 80, GFP_ATOMIC)) == NULL)
+		return;
+
+	cb = (struct dn_skb_cb *)skb->cb;	
+	msg = (struct nsp_data_seg_msg *)skb_put(skb, sizeof(*msg));
+	msg->msgflg = 0x10;			/* Link svc message	*/
+	msg->dstaddr = scp->addrrem;
+	msg->srcaddr = scp->addrloc;
+
+	msg1 = (struct nsp_data_opt_msg *)skb_put(skb, sizeof(*msg1));
+	msg1->acknum = dn_htons((scp->ackxmt_oth & 0x0FFF) | 0x8000);
+	msg1->segnum = dn_htons(cb->segnum = (scp->numoth++ & 0x0FFF));
+        msg1->lsflgs = flgs;
+
+	/* printk(KERN_DEBUG "dn_nsp_send_lnk: %02x\n", flgs); */
+	
+	dn_nsp_queue_xmit(sk, skb, 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 = &sk->protinfo.dn;
+
+	if (scp->state == DN_CI) {
+		dn_nsp_send_conninit(sk, NSP_RCI);
+		scp->persist = dn_nsp_persist(sk);
+	}
+
+	return 0;
+}
+
+void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
+{
+	struct dn_scp *scp = &sk->protinfo.dn;
+	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) ? GFP_KERNEL : GFP_ATOMIC)) == NULL)
+		return;
+
+	cb  = (struct dn_skb_cb *)skb->cb;
+	msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));
+
+	msg->msgflg	= msgflg;
+	msg->dstaddr	= 0x0000;		/* Remote Node will assign it*/
+
+	if (msgflg == NSP_CI)
+		sk->protinfo.dn.addrloc = dn_alloc_port();
+
+	msg->srcaddr	= sk->protinfo.dn.addrloc;
+	msg->services	= 1 | NSP_FC_NONE;	/* Requested flow control    */
+	msg->info	= 0x03;			/* Version Number            */	
+	msg->segsize	= dn_htons(1459);	/* 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);
+
+	sk->protinfo.dn.persist = dn_nsp_persist(sk);
+	sk->protinfo.dn.persist_fxn = dn_nsp_retrans_conninit;
+
+	cb->rt_flags = DN_RT_F_RQR;
+
+	dn_send_skb(skb);	
+}
+