patch-2.1.16 linux/net/x25/x25_in.c

• Lines: 337
• Date: Wed Dec 18 12:07:56 1996
• Orig file: v2.1.15/linux/net/x25/x25_in.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.15/linux/net/x25/x25_in.c linux/net/x25/x25_in.c
@@ -0,0 +1,336 @@
+/*
+ *	X.25 Packet Layer release 001
+ *
+ *	This is ALPHA test software. This code may break your machine, randomly fail to work with new 
+ *	releases, misbehave and/or generally screw up. It might even work. 
+ *
+ *	This code REQUIRES 2.1.15 or higher
+ *
+ *	This module:
+ *		This module 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 (at your option) any later version.
+ *
+ *	History
+ *	X.25 001	Jonathan Naylor	Started coding.
+ */
+
+#include <linux/config.h>
+#if defined(CONFIG_X25) || defined(CONFIG_X25_MODULE)
+#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/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/ip.h>			/* For ip_rcv */
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/x25.h>
+
+static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
+{
+	struct sk_buff *skbo, *skbn = skb;
+
+	if (more) {
+		sk->protinfo.x25->fraglen += skb->len;
+		skb_queue_tail(&sk->protinfo.x25->fragment_queue, skb);
+		return 0;
+	}
+	
+	if (!more && sk->protinfo.x25->fraglen > 0) {	/* End of fragment */
+		sk->protinfo.x25->fraglen += skb->len;
+		skb_queue_tail(&sk->protinfo.x25->fragment_queue, skb);
+
+		if ((skbn = alloc_skb(sk->protinfo.x25->fraglen, GFP_ATOMIC)) == NULL)
+			return 1;
+
+		skbn->arp  = 1;
+		skb_set_owner_r(skbn, sk);
+		skbn->h.raw = skbn->data;
+
+		skbo = skb_dequeue(&sk->protinfo.x25->fragment_queue);
+		memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
+		kfree_skb(skbo, FREE_READ);
+
+		while ((skbo = skb_dequeue(&sk->protinfo.x25->fragment_queue)) != NULL) {
+			skb_pull(skbo, (sk->protinfo.x25->neighbour->extended) ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
+			memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
+			kfree_skb(skbo, FREE_READ);
+		}
+
+		sk->protinfo.x25->fraglen = 0;		
+	}
+
+	return sock_queue_rcv_skb(sk, skbn);
+}
+
+/*
+ * State machine for state 1, Awaiting Call Accepted State.
+ * The handling of the timer(s) is in file x25_timer.c.
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	switch (frametype) {
+
+		case X25_CALL_ACCEPTED:
+			sk->protinfo.x25->condition = 0x00;
+			sk->protinfo.x25->timer     = 0;
+			sk->protinfo.x25->vs        = 0;
+			sk->protinfo.x25->va        = 0;
+			sk->protinfo.x25->vr        = 0;
+			sk->protinfo.x25->vl        = 0;
+			sk->protinfo.x25->state     = X25_STATE_3;
+			sk->state                   = TCP_ESTABLISHED;
+			if (!sk->dead)
+				sk->state_change(sk);
+			break;
+
+		case X25_CLEAR_REQUEST:
+			x25_clear_queues(sk);
+			sk->protinfo.x25->state = X25_STATE_0;
+			sk->state               = TCP_CLOSE;
+			sk->err                 = ECONNREFUSED;
+			sk->shutdown           |= SEND_SHUTDOWN;
+			if (!sk->dead)
+				sk->state_change(sk);
+			sk->dead                = 1;
+			break;
+
+		default:
+			printk(KERN_WARNING "x25: unknown %02X in state 1\n", frametype);
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * State machine for state 2, Awaiting Clear Confirmation State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	switch (frametype) {
+
+		case X25_CLEAR_REQUEST:
+		case X25_CLEAR_CONFIRMATION:
+			sk->protinfo.x25->state = X25_STATE_0;
+			sk->state               = TCP_CLOSE;
+			sk->err                 = 0;
+			sk->shutdown           |= SEND_SHUTDOWN;
+			if (!sk->dead)
+				sk->state_change(sk);
+			sk->dead                = 1;
+			break;
+
+		default:
+			printk(KERN_WARNING "x25: unknown %02X in state 2\n", frametype);
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * State machine for state 3, Connected State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
+{
+	int queued = 0;
+	int modulus;
+	
+	modulus = (sk->protinfo.x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
+
+	switch (frametype) {
+
+		case X25_RESET_REQUEST:
+			x25_clear_queues(sk);
+			x25_write_internal(sk, X25_RESET_CONFIRMATION);
+			sk->protinfo.x25->condition = 0x00;
+			sk->protinfo.x25->timer     = 0;
+			sk->protinfo.x25->vs        = 0;
+			sk->protinfo.x25->vr        = 0;
+			sk->protinfo.x25->va        = 0;
+			sk->protinfo.x25->vl        = 0;
+			break;
+
+		case X25_CLEAR_REQUEST:
+			x25_clear_queues(sk);
+			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+			sk->protinfo.x25->state = X25_STATE_0;
+			sk->state               = TCP_CLOSE;
+			sk->err                 = 0;
+			sk->shutdown           |= SEND_SHUTDOWN;
+			if (!sk->dead)
+				sk->state_change(sk);
+			sk->dead                = 1;
+			break;
+
+		case X25_RR:
+		case X25_RNR:
+			if (frametype == X25_RNR) {
+				sk->protinfo.x25->condition |= X25_COND_PEER_RX_BUSY;
+			} else {
+				sk->protinfo.x25->condition &= ~X25_COND_PEER_RX_BUSY;
+			}
+			if (!x25_validate_nr(sk, nr)) {
+				x25_clear_queues(sk);
+				x25_write_internal(sk, X25_RESET_REQUEST);
+				sk->protinfo.x25->condition = 0x00;
+				sk->protinfo.x25->vs        = 0;
+				sk->protinfo.x25->vr        = 0;
+				sk->protinfo.x25->va        = 0;
+				sk->protinfo.x25->vl        = 0;
+				sk->protinfo.x25->state     = X25_STATE_4;
+				sk->protinfo.x25->timer     = sk->protinfo.x25->t22;
+			} else {
+				if (sk->protinfo.x25->condition & X25_COND_PEER_RX_BUSY) {
+					x25_frames_acked(sk, nr);
+				} else {
+					x25_check_iframes_acked(sk, nr);
+				}
+			}
+			break;
+			
+		case X25_DATA:	/* XXX */
+			sk->protinfo.x25->condition &= ~X25_COND_PEER_RX_BUSY;
+			if (!x25_validate_nr(sk, nr)) {
+				x25_clear_queues(sk);
+				x25_write_internal(sk, X25_RESET_REQUEST);
+				sk->protinfo.x25->condition = 0x00;
+				sk->protinfo.x25->vs        = 0;
+				sk->protinfo.x25->vr        = 0;
+				sk->protinfo.x25->va        = 0;
+				sk->protinfo.x25->vl        = 0;
+				sk->protinfo.x25->state     = X25_STATE_4;
+				sk->protinfo.x25->timer     = sk->protinfo.x25->t22;
+				break;
+			}
+			if (sk->protinfo.x25->condition & X25_COND_PEER_RX_BUSY) {
+				x25_frames_acked(sk, nr);
+			} else {
+				x25_check_iframes_acked(sk, nr);
+			}
+			if (sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)
+				break;
+			if (ns == sk->protinfo.x25->vr) {
+				if (x25_queue_rx_frame(sk, skb, m) == 0) {
+					sk->protinfo.x25->vr = (sk->protinfo.x25->vr + 1) % modulus;
+					queued = 1;
+				} else {
+					sk->protinfo.x25->condition |= X25_COND_OWN_RX_BUSY;
+				}
+			}
+			/*
+			 *	If the window is full Ack it immediately, else
+			 *	start the holdback timer.
+			 */
+			if (((sk->protinfo.x25->vl + sk->protinfo.x25->facilities.window_size) % modulus) == sk->protinfo.x25->vr) {
+				sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
+				sk->protinfo.x25->timer      = 0;
+				x25_enquiry_response(sk);
+			} else {
+				sk->protinfo.x25->condition |= X25_COND_ACK_PENDING;
+				sk->protinfo.x25->timer      = sk->protinfo.x25->t2;
+			}
+			break;
+
+		default:
+			printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
+			break;
+	}
+
+	return queued;
+}
+
+/*
+ * State machine for state 4, Awaiting Reset Confirmation State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	switch (frametype) {
+
+		case X25_RESET_CONFIRMATION:
+		case X25_RESET_REQUEST:
+			sk->protinfo.x25->timer     = 0;
+			sk->protinfo.x25->condition = 0x00;
+			sk->protinfo.x25->va        = 0;
+			sk->protinfo.x25->vr        = 0;
+			sk->protinfo.x25->vs        = 0;
+			sk->protinfo.x25->vl        = 0;
+			sk->protinfo.x25->state     = X25_STATE_3;
+			break;
+
+		case X25_CLEAR_REQUEST:
+			x25_clear_queues(sk);
+			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+			sk->protinfo.x25->timer = 0;
+			sk->protinfo.x25->state = X25_STATE_0;
+			sk->state               = TCP_CLOSE;
+			sk->err                 = 0;
+			sk->shutdown           |= SEND_SHUTDOWN;
+			if (!sk->dead)
+				sk->state_change(sk);
+			sk->dead                = 1;
+			break;
+
+		default:
+			printk(KERN_WARNING "x25: unknown %02X in state 4\n", frametype);
+			break;
+	}
+
+	return 0;
+}
+
+/* Higher level upcall for a LAPB frame */
+int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb)
+{
+	int queued = 0, frametype, ns, nr, q, d, m;
+	
+	if (sk->protinfo.x25->state == X25_STATE_0)
+		return 0;
+
+	del_timer(&sk->timer);
+
+	frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
+
+	switch (sk->protinfo.x25->state) {
+		case X25_STATE_1:
+			queued = x25_state1_machine(sk, skb, frametype);
+			break;
+		case X25_STATE_2:
+			queued = x25_state2_machine(sk, skb, frametype);
+			break;
+		case X25_STATE_3:
+			queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
+			break;
+		case X25_STATE_4:
+			queued = x25_state4_machine(sk, skb, frametype);
+			break;
+	}
+
+	x25_set_timer(sk);
+
+	return queued;
+}
+
+#endif