patch-2.1.16 linux/net/x25/x25_link.c

• Lines: 466
• Date: Wed Dec 18 12:07:56 1996
• Orig file: v2.1.15/linux/net/x25/x25_link.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.15/linux/net/x25/x25_link.c linux/net/x25/x25_link.c
@@ -0,0 +1,465 @@
+/*
+ *	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 <asm/segment.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/firewall.h>
+#include <net/x25.h>
+
+static struct x25_neigh *x25_neigh_list = NULL;
+
+static void x25_link_timer(unsigned long);
+
+/*
+ *	Linux set/reset timer routines
+ */
+static void x25_link_set_timer(struct x25_neigh *neigh)
+{
+	unsigned long flags;
+	
+	save_flags(flags);
+	cli();
+	del_timer(&neigh->timer);
+	restore_flags(flags);
+
+	neigh->timer.next     = neigh->timer.prev = NULL;	
+	neigh->timer.data     = (unsigned long)neigh;
+	neigh->timer.function = &x25_link_timer;
+
+	neigh->timer.expires  = jiffies + 100;
+	add_timer(&neigh->timer);
+}
+
+static void x25_link_reset_timer(struct x25_neigh *neigh)
+{
+	unsigned long flags;
+	
+	save_flags(flags);
+	cli();
+	del_timer(&neigh->timer);
+	restore_flags(flags);
+
+	neigh->timer.data     = (unsigned long)neigh;
+	neigh->timer.function = &x25_link_timer;
+	neigh->timer.expires  = jiffies + 100;
+	add_timer(&neigh->timer);
+}
+
+/*
+ *	X.25 Link TIMER 
+ *
+ *	This routine is called every second. Decrement timer by this
+ *	amount - if expired then process the event.
+ */
+static void x25_link_timer(unsigned long param)
+{
+	struct x25_neigh *neigh = (struct x25_neigh *)param;
+
+	if (neigh->t20timer == 0 || --neigh->t20timer > 0) {
+		x25_link_reset_timer(neigh);
+		return;
+	}
+
+	/*
+	 * T20 for a link has expired.
+	 */
+	x25_transmit_restart_request(neigh);
+
+	neigh->t20timer = neigh->t20;
+
+	x25_link_set_timer(neigh);
+}
+
+/*
+ *	This handles all restart and diagnostic frames.
+ */
+void x25_link_control(struct sk_buff *skb, struct x25_neigh *neigh, unsigned short frametype)
+{
+	struct sk_buff *skbn;
+
+	switch (frametype) {
+		case X25_RESTART_REQUEST:
+			neigh->t20timer = 0;
+			neigh->state    = 1;
+			del_timer(&neigh->timer);
+			x25_transmit_restart_confirmation(neigh);
+			break;
+
+		case X25_RESTART_CONFIRMATION:
+			neigh->t20timer = 0;
+			neigh->state    = 1;
+			del_timer(&neigh->timer);
+			break;
+
+		case X25_DIAGNOSTIC:
+			printk(KERN_WARNING "x25: diagnostic #%d\n", skb->data[3]);
+			break;
+			
+		default:
+			printk(KERN_WARNING "x25: received unknown %02X with LCI 000\n", frametype);
+			break;
+	}
+
+	if (neigh->state == 1) {
+		while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
+			x25_send_frame(skbn, neigh->dev);
+	}
+}
+
+/*
+ *	This routine is called when a Restart Request is needed
+ */
+void x25_transmit_restart_request(struct x25_neigh *neigh)
+{
+	struct sk_buff *skb;
+	unsigned char *dptr;
+	int len;
+
+	len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
+
+	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
+		return;
+
+	skb_reserve(skb, X25_MAX_L2_LEN);
+
+	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
+
+	*dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
+	*dptr++ = 0x00;
+	*dptr++ = X25_RESTART_REQUEST;
+	*dptr++ = 0x00;
+	*dptr++ = 0;
+
+	skb->sk = NULL;
+
+	x25_send_frame(skb, neigh->dev);
+}
+
+/*
+ * This routine is called when a Restart Confirmation is needed
+ */
+void x25_transmit_restart_confirmation(struct x25_neigh *neigh)
+{
+	struct sk_buff *skb;
+	unsigned char *dptr;
+	int len;
+
+	len = X25_MAX_L2_LEN + X25_STD_MIN_LEN;
+
+	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
+		return;
+
+	skb_reserve(skb, X25_MAX_L2_LEN);
+
+	dptr = skb_put(skb, X25_STD_MIN_LEN);
+
+	*dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
+	*dptr++ = 0x00;
+	*dptr++ = X25_RESTART_CONFIRMATION;
+
+	skb->sk = NULL;
+
+	x25_send_frame(skb, neigh->dev);
+}
+
+/*
+ * This routine is called when a Diagnostic is required.
+ */
+void x25_transmit_diagnostic(struct x25_neigh *neigh, unsigned char diag)
+{
+	struct sk_buff *skb;
+	unsigned char *dptr;
+	int len;
+
+	len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 1;
+
+	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
+		return;
+
+	skb_reserve(skb, X25_MAX_L2_LEN);
+
+	dptr = skb_put(skb, X25_STD_MIN_LEN + 1);
+
+	*dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
+	*dptr++ = 0x00;
+	*dptr++ = X25_DIAGNOSTIC;
+	*dptr++ = diag;
+
+	skb->sk = NULL;
+
+	x25_send_frame(skb, neigh->dev);
+}
+
+/*
+ *	This routine is called when a Clear Request is needed outside of the context
+ *	of a connected socket.
+ */
+void x25_transmit_clear_request(struct x25_neigh *neigh, unsigned int lci, unsigned char cause)
+{
+	struct sk_buff *skb;
+	unsigned char *dptr;
+	int len;
+
+	len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
+
+	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
+		return;
+
+	skb_reserve(skb, X25_MAX_L2_LEN);
+
+	dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
+
+	*dptr++ = ((lci >> 8) & 0x0F) | (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
+	*dptr++ = ((lci >> 0) & 0xFF);
+	*dptr++ = X25_CLEAR_REQUEST;
+	*dptr++ = cause;
+	*dptr++ = 0x00;
+
+	skb->sk = NULL;
+
+	x25_send_frame(skb, neigh->dev);
+}
+
+void x25_transmit_link(struct sk_buff *skb, struct x25_neigh *neigh)
+{
+#ifdef CONFIG_FIREWALL
+	if (call_fw_firewall(PF_X25, skb->dev, skb->data, NULL) != FW_ACCEPT)
+		return;
+#endif
+
+	if (!x25_link_up(neigh->dev))
+		neigh->state = 0;
+
+	skb->arp  = 1;
+
+	if (neigh->state == 1) {
+		x25_send_frame(skb, neigh->dev);
+	} else {
+		skb_queue_tail(&neigh->queue, skb);
+		
+		if (neigh->t20timer == 0) {
+			x25_transmit_restart_request(neigh);
+			neigh->t20timer = neigh->t20;
+			x25_link_set_timer(neigh);
+		}
+	}
+}
+
+/*
+ *	Add a new device.
+ */
+void x25_link_device_up(struct device *dev)
+{
+	struct x25_neigh *x25_neigh;
+	unsigned long flags;
+
+	if ((x25_neigh = (struct x25_neigh *)kmalloc(sizeof(*x25_neigh), GFP_ATOMIC)) == NULL)
+		return;
+
+	skb_queue_head_init(&x25_neigh->queue);
+	init_timer(&x25_neigh->timer);
+
+	x25_neigh->dev      = dev;
+	x25_neigh->state    = 0;
+	x25_neigh->extended = 0;
+	x25_neigh->t20timer = 0;
+	x25_neigh->t20      = sysctl_x25_restart_request_timeout;
+
+	save_flags(flags); cli();
+	x25_neigh->next = x25_neigh_list;
+	x25_neigh_list  = x25_neigh;
+	restore_flags(flags);
+}
+
+static void x25_remove_neigh(struct x25_neigh *x25_neigh)
+{
+	struct x25_neigh *s;
+	unsigned long flags;
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&x25_neigh->queue)) != NULL)
+		kfree_skb(skb, FREE_WRITE);
+	
+	del_timer(&x25_neigh->timer);
+
+	save_flags(flags);
+	cli();
+
+	if ((s = x25_neigh_list) == x25_neigh) {
+		x25_neigh_list = x25_neigh->next;
+		restore_flags(flags);
+		kfree_s(x25_neigh, sizeof(struct x25_neigh));
+		return;
+	}
+
+	while (s != NULL && s->next != NULL) {
+		if (s->next == x25_neigh) {
+			s->next = x25_neigh->next;
+			restore_flags(flags);
+			kfree_s(x25_neigh, sizeof(struct x25_neigh));
+			return;
+		}
+
+		s = s->next;
+	}
+
+	restore_flags(flags);
+}
+
+/*
+ *	A device has been removed, remove its links.
+ */
+void x25_link_device_down(struct device *dev)
+{
+	struct x25_neigh *neigh, *x25_neigh = x25_neigh_list;
+
+	while (x25_neigh != NULL) {
+		neigh     = x25_neigh;
+		x25_neigh = x25_neigh->next;
+		
+		if (neigh->dev == dev)
+			x25_remove_neigh(neigh);
+	}
+}
+
+/*
+ *	Given a device, return the neighbour address.
+ */
+struct x25_neigh *x25_get_neigh(struct device *dev)
+{
+	struct x25_neigh *x25_neigh;
+
+	for (x25_neigh = x25_neigh_list; x25_neigh != NULL; x25_neigh = x25_neigh->next)
+		if (x25_neigh->dev == dev)
+			return x25_neigh;
+
+	return NULL;
+}
+
+/*
+ *	Handle the ioctls that control the subscription functions.
+ */
+int x25_subscr_ioctl(unsigned int cmd, void *arg)
+{
+	struct x25_subscrip_struct x25_subscr;
+	struct x25_neigh *x25_neigh;
+	struct device *dev;
+	int err;
+
+	switch (cmd) {
+
+		case SIOCX25SETSUBSCR:
+			if ((err = verify_area(VERIFY_READ, arg, sizeof(struct x25_subscrip_struct))) != 0)
+				return err;
+			copy_from_user(&x25_subscr, arg, sizeof(struct x25_subscrip_struct));
+			if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
+				return -EINVAL;
+			if ((x25_neigh = x25_get_neigh(dev)) == NULL)
+				return -EINVAL;
+			if (x25_subscr.extended != 0 && x25_subscr.extended != 1)
+				return -EINVAL;
+			x25_neigh->extended = x25_subscr.extended;
+			break;
+
+		default:
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+int x25_link_get_info(char *buffer, char **start, off_t offset, int length, int dummy)
+{
+	struct x25_neigh *x25_neigh;
+	int len     = 0;
+	off_t pos   = 0;
+	off_t begin = 0;
+
+	cli();
+
+	len += sprintf(buffer, "device           st    t20    ext\n");
+
+	for (x25_neigh = x25_neigh_list; x25_neigh != NULL; x25_neigh = x25_neigh->next) {
+		len += sprintf(buffer + len, "%-15s  %2d %3d/%03d  %d\n",
+			x25_neigh->dev->name,
+			x25_neigh->state,
+			x25_neigh->t20timer / X25_SLOWHZ,
+			x25_neigh->t20      / X25_SLOWHZ,
+			x25_neigh->extended);
+
+		pos = begin + len;
+
+		if (pos < offset) {
+			len   = 0;
+			begin = pos;
+		}
+		
+		if (pos > offset + length)
+			break;
+	}
+
+	sti();
+
+	*start = buffer + (offset - begin);
+	len   -= (offset - begin);
+
+	if (len > length) len = length;
+
+	return len;
+} 
+
+#ifdef MODULE
+
+/*
+ *	Release all memory associated with X.25 neighbour structures.
+ */
+void x25_link_free(void)
+{
+	struct x25_neigh *neigh, *x25_neigh = x25_neigh_list;
+
+	while (x25_neigh != NULL) {
+		neigh     = x25_neigh;
+		x25_neigh = x25_neigh->next;
+		
+		x25_remove_neigh(neigh);
+	}
+}
+
+#endif
+
+#endif