patch-2.1.20 linux/net/lapb/lapb_out.c

• Lines: 253
• Date: Thu Jan 2 15:13:29 1997
• Orig file: v2.1.19/linux/net/lapb/lapb_out.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.19/linux/net/lapb/lapb_out.c linux/net/lapb/lapb_out.c
@@ -0,0 +1,252 @@
+/*
+ *	LAPB 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/ NET3.038
+ *
+ *	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
+ *	LAPB 001	Jonathan Naylor	Started Coding
+ */
+
+#include <linux/config.h>
+#if defined(CONFIG_LAPB) || defined(CONFIG_LAPB_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/skbuff.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/lapb.h>
+
+/* 
+ *  This procedure is passed a buffer descriptor for an iframe. It builds
+ *  the rest of the control part of the frame and then writes it out.
+ */
+static void lapb_send_iframe(lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
+{
+	unsigned char *frame;
+
+	if (skb == NULL)
+		return;
+
+	if (lapb->mode & LAPB_EXTENDED) {
+		frame = skb_push(skb, 2);
+
+		frame[0] = I;
+		frame[0] |= (lapb->vs << 1);
+		frame[1] = (poll_bit) ? LAPB_EPF : 0;
+		frame[1] |= (lapb->vr << 1);
+	} else {
+		frame = skb_push(skb, 1);
+
+		*frame = I;
+		*frame |= (poll_bit) ? LAPB_SPF : 0;
+		*frame |= (lapb->vr << 5);
+		*frame |= (lapb->vs << 1);
+	}
+
+	lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);	
+}
+
+void lapb_kick(lapb_cb *lapb)
+{
+	struct sk_buff *skb, *skbn;
+	int modulus, last = 1;
+	unsigned short start, end, next;
+
+	del_timer(&lapb->timer);
+
+	modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
+
+	start = (skb_peek(&lapb->ack_queue) == NULL) ? lapb->va : lapb->vs;
+	end   = (lapb->va + lapb->window) % modulus;
+
+	if (!(lapb->condition & PEER_RX_BUSY_CONDITION) &&
+	    start != end                                &&
+	    skb_peek(&lapb->write_queue) != NULL) {
+
+		lapb->vs = start;
+
+		/*
+		 * Dequeue the frame and copy it.
+		 */
+		skb  = skb_dequeue(&lapb->write_queue);
+
+		do {
+			if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
+				skb_queue_head(&lapb->write_queue, skb);
+				break;
+			}
+
+			next = (lapb->vs + 1) % modulus;
+#ifdef notdef
+			last = (next == end) || skb_peek(&lapb->write_queue) == NULL;
+#else
+			last = (next == end);
+#endif
+			/*
+			 * Transmit the frame copy.
+			 */
+			lapb_send_iframe(lapb, skbn, POLLOFF);
+
+			lapb->vs = next;
+
+			/*
+			 * Requeue the original data frame.
+			 */
+			skb_queue_tail(&lapb->ack_queue, skb);
+#ifdef notdef
+		} while (!last);
+#else
+		} while (!last && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
+#endif
+		lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+
+		if (lapb->t1timer == 0)
+			lapb->t1timer = lapb->t1;
+	}
+
+	lapb_set_timer(lapb);
+}
+
+void lapb_transmit_buffer(lapb_cb *lapb, struct sk_buff *skb, int type)
+{
+	unsigned char *ptr;
+
+	ptr = skb_push(skb, 1);
+
+	if (lapb->mode & LAPB_MLP) {
+		if (lapb->mode & LAPB_DCE) {
+			if (type == LAPB_COMMAND)
+				*ptr = LAPB_ADDR_C;
+			if (type == LAPB_RESPONSE)
+				*ptr = LAPB_ADDR_D;
+		} else {
+			if (type == LAPB_COMMAND)
+				*ptr = LAPB_ADDR_D;
+			if (type == LAPB_RESPONSE)
+				*ptr = LAPB_ADDR_C;
+		}
+	} else {
+		if (lapb->mode & LAPB_DCE) {
+			if (type == LAPB_COMMAND)
+				*ptr = LAPB_ADDR_A;
+			if (type == LAPB_RESPONSE)
+				*ptr = LAPB_ADDR_B;
+		} else {
+			if (type == LAPB_COMMAND)
+				*ptr = LAPB_ADDR_B;
+			if (type == LAPB_RESPONSE)
+				*ptr = LAPB_ADDR_A;
+		}
+	}
+
+#if LAPB_DEBUG > 2
+	printk(KERN_DEBUG "lapb: (%p) S%d TX %02X %02X %02X\n", lapb->token, lapb->state, skb->data[0], skb->data[1], skb->data[2]);
+#endif
+
+	if (!lapb_data_transmit(lapb, skb))
+		kfree_skb(skb, FREE_WRITE);
+}
+
+void lapb_nr_error_recovery(lapb_cb *lapb)
+{
+	lapb_establish_data_link(lapb);
+}
+
+void lapb_establish_data_link(lapb_cb *lapb)
+{
+	lapb->condition = 0x00;
+	lapb->n2count   = 0;
+
+	if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+		printk(KERN_DEBUG "lapb: (%p) S%d TX SABME(1)\n", lapb->token, lapb->state);
+#endif
+		lapb_send_control(lapb, SABME, POLLON, LAPB_COMMAND);
+	} else {
+#if LAPB_DEBUG > 1
+		printk(KERN_DEBUG "lapb: (%p) S%d TX SABM(1)\n", lapb->token, lapb->state);
+#endif
+		lapb_send_control(lapb, SABM, POLLON, LAPB_COMMAND);
+	}
+	
+	lapb->t2timer = 0;
+	lapb->t1timer = lapb->t1;
+}
+
+void lapb_transmit_enquiry(lapb_cb *lapb)
+{
+#if LAPB_DEBUG > 1
+	printk(KERN_DEBUG "lapb: (%p) S%d TX RR(1) R%d\n", lapb->token, lapb->state, lapb->vr);
+#endif
+
+	lapb_send_control(lapb, RR, POLLON, C_COMMAND);
+
+	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+
+	lapb->t1timer = lapb->t1;
+}
+ 	
+void lapb_enquiry_response(lapb_cb *lapb)
+{
+#if LAPB_DEBUG > 1
+	printk(KERN_DEBUG "lapb: (%p) S%d TX RR(1) R%d\n", lapb->token, lapb->state, lapb->vr);
+#endif
+
+	lapb_send_control(lapb, RR, POLLON, LAPB_RESPONSE);
+
+	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+}
+
+void lapb_timeout_response(lapb_cb *lapb)
+{
+#if LAPB_DEBUG > 1
+	printk(KERN_DEBUG "lapb: (%p) S%d TX RR(0) R%d\n", lapb->token, lapb->state, lapb->vr);
+#endif
+
+	lapb_send_control(lapb, RR, POLLOFF, LAPB_RESPONSE);
+
+	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+}
+
+void lapb_check_iframes_acked(lapb_cb *lapb, unsigned short nr)
+{
+	if (lapb->vs == nr) {
+		lapb_frames_acked(lapb, nr);
+		lapb->t1timer = 0;
+	} else {
+		if (lapb->va != nr) {
+			lapb_frames_acked(lapb, nr);
+			lapb->t1timer = lapb->t1;
+		}
+	}
+}
+
+void lapb_check_need_response(lapb_cb *lapb, int type, int pf)
+{
+	if (type == LAPB_COMMAND && pf)
+		lapb_enquiry_response(lapb);
+}
+
+#endif