kgdb 2.0.5

["Amit S. Kale" <amitkale@emsyssoft.com>]

Hi,

kgdb 2.0.5 is available at 
http://kgdb.sourceforge.net/kgdb-2/linux-2.6.1-kgdb-2.0.5.tar.bz2

ChangeLog
2004-01-20 Amit S. Kale <amitkale@emsyssoft.com>
        * Created a ring buffer for kgdb ethernet packets. Several
        fixes and changes to kgdb on ethernet.

2004-01-20 TimeSys Corporation
        * Fixed a problem with not responding to Ctrl+C during priting of
        console messages through gdb.

I have pasted below eth.patch for review. When using the ethernet interface, 
gdb times out several times. It receives packets and junk instead of acks. I 
see following type of messages out of 8139too.c on the console 
"eth0:Out-of-sync dirty pointer, 15 vs. 20."

Any comments/suggestions/fixes on this patch are most welcome.
Thanks.
-- 
Amit Kale
EmSysSoft (http://www.emsyssoft.com)
KGDB: Linux Kernel Source Level Debugger (http://kgdb.sourceforge.net)


diff -Naurp linux-2.6.1/drivers/net/Kconfig 
linux-2.6.1-kgdb-2.0.5-eth/drivers/net/Kconfig
--- linux-2.6.1/drivers/net/Kconfig	2003-11-24 07:02:50.000000000 +0530
+++ linux-2.6.1-kgdb-2.0.5-eth/drivers/net/Kconfig	2004-01-12 
19:11:13.000000000 +0530
@@ -187,6 +187,12 @@ config NET_ETHERNET
 	  Note that the answer to this question won't directly affect the
 	  kernel: saying N will just cause the configurator to skip all
 	  the questions about Ethernet network cards. If unsure, say N.
+	
+config KGDB_ETH
+	bool "KGDB: On ethernet"
+	depends on KGDB
+	help
+	  Uses ethernet interface for kgdb.
 
 config MII
 	tristate "Generic Media Independent Interface device support"
diff -Naurp linux-2.6.1/drivers/net/kgdb_eth.c 
linux-2.6.1-kgdb-2.0.5-eth/drivers/net/kgdb_eth.c
--- linux-2.6.1/drivers/net/kgdb_eth.c	1970-01-01 05:30:00.000000000 +0530
+++ linux-2.6.1-kgdb-2.0.5-eth/drivers/net/kgdb_eth.c	2004-01-20 
16:14:22.000000000 +0530
@@ -0,0 +1,704 @@
+/*
+ * Network interface GDB stub
+ *
+ * Copyright (C), 2004 Amit S. Kale 
+ *
+ * Written by San Mehat (nettwerk@biodome.org)
+ * Based upon 'gdbserial' by David Grothe (dave@gcom.com)
+ * and Scott Foehner (sfoehner@engr.sgi.com)
+ *
+ * Twiddled for 2.6 by Robert Walsh <rjwalsh@durables.org>
+ * and wangdi <wangdi@clusterfs.com>.
+ *
+ * Restructured for generic a gdb interface 
+ * Reveral changes to make it free of device driver changes.
+ * Added internal buffers for this interface.
+ * 	by Amit S. Kale <amitkale@emsyssoft.com>
+ * Some cleanups by Pavel Machek <pavel@suse.cz>
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/config.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/kgdb.h>
+#include <linux/if_ether.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/inet.h>
+#include <linux/notifier.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+#include <asm/bitops.h>
+#include <asm/system.h>
+#include <asm/atomic.h>
+
+#define	GDB_BUF_SIZE	512		/* power of 2, please */
+
+#define CHUNKSIZE 30
+#define MAXINCHUNK (CHUNKSIZE + 8)
+
+static char	kgdb_buf[GDB_BUF_SIZE];
+static int	kgdb_buf_in_inx;
+static atomic_t	kgdb_buf_in_cnt;
+static int	kgdb_buf_out_inx;
+
+static unsigned int	kgdb_remoteip = 0;
+static unsigned short	kgdb_listenport = 6443;
+static unsigned short	kgdb_sendport= 6442;
+static int		kgdb_eth = -1; /* Default tty mode */
+static unsigned char	kgdb_remotemac[6] = {0xff,0xff,0xff,0xff,0xff,0xff};
+static unsigned char	kgdb_localmac[6] = {0xff,0xff,0xff,0xff,0xff,0xff};
+
+static char		kgdbeth_sendbuf[MAXINCHUNK];
+static int		kgdbeth_sendbufchars;
+static irqreturn_t	(*kgdbeth_irqhandler)(int, void *, struct pt_regs *) = 
NULL;
+
+struct net_device *kgdb_netdevice = NULL;
+
+/* Indicates dept of recursion for xmitlock hold */
+static int xlockholdcount = 0;
+
+/* kgdb ethernet ring buffers. Increase the space if you get panics in
+ * kgdbeth_alloc_skb.
+ * Status of send_skbs can be known from the field users.
+ * If it's 1 the buffer is free.
+ * If the count 2 or more, the buffer is in use.
+ * Keeping 1 as the initial count prevents kfree_skb from freeing it. */
+#define SEND_BUFLEN 1024
+#define NUM_SENDBUF 128
+static char *send_bufs[NUM_SENDBUF];
+static struct sk_buff *send_skbs[NUM_SENDBUF];
+static struct sk_buff *send_skb;
+static int bufnum;
+
+static char kgdb_netdevname[16];
+
+#ifdef CONFIG_KGDB_CONSOLE
+#error kgdb over ethernet is not yet ready for console messages.
+#endif
+
+/*
+ * Returns next skb from kgdb skbs.
+ * Initializes users field of the skb to 2 so that kfree_skb doesn't attempt
+ * freeing it.
+ * Always call after holding xmitlock of the ethernet device.
+ */
+
+struct sk_buff *kgdbeth_alloc_skb(int size)
+{
+	struct sk_buff *skb;
+	u8		*data;
+	int i;
+
+	i = bufnum;
+
+	do {
+		skb = send_skbs[i];
+
+		if (atomic_read(&skb->users) == 1) {
+			bufnum = i;
+			i = -1;
+			break;
+		}
+		i = (i + 1) % NUM_SENDBUF;
+	} while (i != bufnum);
+	if (i == bufnum) {
+		panic("kgdb ethernet buffer overflow\n");
+	}
+	data = (u8 *)(send_bufs[bufnum]);
+
+	size = SKB_DATA_ALIGN(size);
+	if (size + sizeof(struct skb_shared_info) > SEND_BUFLEN)
+		panic("kgdb ethernet buffer too short for this request");
+
+	memset(skb, 0, offsetof(struct sk_buff, truesize));
+	skb->truesize = size + sizeof(struct sk_buff);
+	atomic_set(&skb->users, 2);
+	skb->head = data;
+	skb->data = data;
+	skb->tail = data;
+	skb->end  = data + size;
+
+	atomic_set(&(skb_shinfo(skb)->dataref), 1);
+	skb_shinfo(skb)->nr_frags  = 0;
+	skb_shinfo(skb)->tso_size = 0;
+	skb_shinfo(skb)->tso_segs = 0;
+	skb_shinfo(skb)->frag_list = NULL;
+
+	return skb;
+}
+
+/* Holds xmitlock of the ethernet device 
+ * Recursive calls allowed */
+static void kgdbeth_holdxlock(void)
+{
+	if (spin_is_locked(&kgdb_netdevice->xmit_lock)) {
+		if (kgdb_netdevice->xmit_lock_owner == smp_processor_id()) {
+			goto gotit;
+		}
+	}
+	spin_lock(&kgdb_netdevice->xmit_lock);
+	kgdb_netdevice->xmit_lock_owner = smp_processor_id();
+
+gotit:
+	xlockholdcount++;
+}
+
+/* releases xmitlock of the ethernet device 
+ * Recursive calls allowed */
+static void kgdbeth_relxlock(void)
+{
+	if (--xlockholdcount) {
+		kgdb_netdevice->xmit_lock_owner = -1;
+		spin_unlock(&kgdb_netdevice->xmit_lock);
+	}
+}
+
+/*
+ * Get a char if available, return -1 if nothing available.
+ * Empty the receive buffer first, then look at the interface hardware.
+ */
+static int
+read_char(void)
+{
+	/* intr routine has queued chars */
+	if (atomic_read(&kgdb_buf_in_cnt) != 0) {
+		int chr;
+
+		chr = kgdb_buf[kgdb_buf_out_inx++];
+		kgdb_buf_out_inx &= (GDB_BUF_SIZE - 1);
+		atomic_dec(&kgdb_buf_in_cnt);
+		return chr;
+	}
+
+	return -1; /* no data */
+}
+
+/*
+ * Wait until the interface can accept a char, then write it.
+ */
+static void
+write_buffer(char *buf, int len)
+{
+	int			total_len, eth_len, ip_len, udp_len;
+	struct in_device	*in_dev;
+	struct sk_buff		*skb;
+	struct udphdr		*udph;
+	struct iphdr		*iph;
+	struct ethhdr		*eth;
+
+	if (!(in_dev = (struct in_device *) kgdb_netdevice->ip_ptr)) {
+		panic("No in_device available for interface!\n");
+	}
+
+	if (!(in_dev->ifa_list)) {
+		panic("No interface address set for interface!\n");
+	}
+	kgdbeth_holdxlock();
+
+	udp_len = len + sizeof(struct udphdr);
+	ip_len = eth_len = udp_len + sizeof(struct iphdr);
+	total_len = eth_len + ETH_HLEN;
+
+	skb = kgdbeth_alloc_skb(total_len);
+
+	skb_reserve(skb, total_len - 1);
+
+	memcpy(skb->data, (unsigned char *) buf, len);
+	skb->len += len;
+
+	udph = (struct udphdr *) skb_push(skb, sizeof(*udph));
+	udph->source = htons(kgdb_listenport);
+	udph->dest   = htons(kgdb_sendport);
+	udph->len    = htons(udp_len);
+	udph->check  = 0;
+
+	iph = (struct iphdr *)skb_push(skb, sizeof(*iph));
+	iph->version  = 4;
+	iph->ihl      = 5;
+	iph->tos      = 0;
+	iph->tot_len  = htons(ip_len);
+	iph->id       = 0;
+	iph->frag_off = 0;
+	iph->ttl      = 64;
+	iph->protocol = IPPROTO_UDP;
+	iph->check    = 0;
+	iph->saddr    = in_dev->ifa_list->ifa_address;
+	iph->daddr    = kgdb_remoteip;
+	iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
+
+	eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
+	eth->h_proto = htons(ETH_P_IP);
+	memcpy(eth->h_source, kgdb_localmac, kgdb_netdevice->addr_len);
+	memcpy(eth->h_dest, kgdb_remotemac, kgdb_netdevice->addr_len);
+
+	kgdb_netdevice->hard_start_xmit(skb, kgdb_netdevice);
+	if (atomic_read(&skb->users) != 1) {
+		BUG();
+	}
+	kgdbeth_relxlock();
+}
+
+static void kgdbeth_flush(void)
+{
+	if (!kgdbeth_sendbufchars) {
+		return;
+	}
+	write_buffer(kgdbeth_sendbuf, kgdbeth_sendbufchars);
+	kgdbeth_sendbufchars = 0;
+}
+
+static void kgdbeth_write_char(int chr)
+{
+	if (kgdbeth_sendbufchars == MAXINCHUNK) {
+		kgdbeth_flush();
+	}
+	kgdbeth_sendbuf[kgdbeth_sendbufchars++] = chr;
+}
+
+
+/*
+ * In the interrupt state the target machine will not respond to any
+ * arp requests, so handle them here.
+ */
+
+static void
+kgdb_eth_reply_arp(void)
+{
+	if (send_skb) {
+		kgdbeth_holdxlock();
+	    	kgdb_netdevice->hard_start_xmit(send_skb, kgdb_netdevice);
+		send_skb = NULL;
+		kgdbeth_relxlock();
+	}
+}
+
+static int
+make_arp_request(struct sk_buff *skb)
+{
+	struct arphdr *arp;
+	unsigned char *arp_ptr;
+	int type = ARPOP_REPLY;
+	int ptype = ETH_P_ARP;
+	u32 sip, tip;
+	unsigned char *sha, *tha;
+	struct in_device *in_dev = (struct in_device *) kgdb_netdevice->ip_ptr;
+
+	/* No arp on this interface */
+
+	if (kgdb_netdevice->flags & IFF_NOARP) {
+		return 0;
+	}
+
+	if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
+				 (2 * kgdb_netdevice->addr_len) +
+				 (2 * sizeof(u32))))) {
+		return 0;
+	}
+
+	skb->h.raw = skb->nh.raw = skb->data;
+	arp = skb->nh.arph;
+
+	if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
+	     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
+	    arp->ar_pro != htons(ETH_P_IP)) {
+		return 0;
+	}
+
+	/* Understand only these message types */
+
+	if (arp->ar_op != htons(ARPOP_REQUEST)) {
+		return 0;
+	}
+
+	/* Extract fields */
+
+	arp_ptr= (unsigned char *)(arp+1);
+	sha = arp_ptr;
+	arp_ptr += kgdb_netdevice->addr_len;
+	memcpy(&sip, arp_ptr, 4);
+	arp_ptr += 4;
+	tha = arp_ptr;
+	arp_ptr += kgdb_netdevice->addr_len;
+	memcpy(&tip, arp_ptr, 4);
+
+	if (tip != in_dev->ifa_list->ifa_address) {
+		return 0;
+	}
+
+	if (kgdb_remoteip != sip) {
+		return 0;
+	}
+
+	/*
+	 * Check for bad requests for 127.x.x.x and requests for multicast
+	 * addresses.  If this is one such, delete it.
+	 */
+
+	if (LOOPBACK(tip) || MULTICAST(tip)) {
+		return 0;
+	}
+	/* reply to the ARP request */
+
+	kgdbeth_holdxlock();
+	if (send_skb) {
+		/* Get rid of any previous replies to ARP request. We hope
+		 * that regular reply to ARP by network layers would have gone
+		 * out by now. */
+		kfree_skb(send_skb);
+	}
+	send_skb = kgdbeth_alloc_skb(sizeof(struct arphdr) +
+			2 * (kgdb_netdevice->addr_len + 4) +
+			LL_RESERVED_SPACE(kgdb_netdevice));
+	kgdbeth_relxlock();
+
+	skb_reserve(send_skb, LL_RESERVED_SPACE(kgdb_netdevice));
+	send_skb->nh.raw = send_skb->data;
+	arp = (struct arphdr *) skb_put(send_skb, sizeof(struct arphdr) + 2 * 
(kgdb_netdevice->addr_len + 4));
+	send_skb->dev = kgdb_netdevice;
+	send_skb->protocol = htons(ETH_P_ARP);
+
+	/* Fill the device header for the ARP frame */
+
+	if (kgdb_netdevice->hard_header &&
+	    kgdb_netdevice->hard_header(send_skb, kgdb_netdevice, ptype,
+				       kgdb_remotemac, kgdb_localmac,
+				       send_skb->len) < 0) {
+		kfree_skb(send_skb);
+		return 0;
+	}
+
+	/*
+	 * Fill out the arp protocol part.
+	 *
+	 * we only support ethernet device type,
+	 * which (according to RFC 1390) should always equal 1 (Ethernet).
+	 */
+
+	arp->ar_hrd = htons(kgdb_netdevice->type);
+	arp->ar_pro = htons(ETH_P_IP);
+
+	arp->ar_hln = kgdb_netdevice->addr_len;
+	arp->ar_pln = 4;
+	arp->ar_op = htons(type);
+
+	arp_ptr=(unsigned char *)(arp + 1);
+
+	memcpy(arp_ptr, kgdb_netdevice->dev_addr, kgdb_netdevice->addr_len);
+	arp_ptr += kgdb_netdevice->addr_len;
+	memcpy(arp_ptr, &tip, 4);
+	arp_ptr += 4;
+	memcpy(arp_ptr, kgdb_localmac, kgdb_netdevice->addr_len);
+	arp_ptr += kgdb_netdevice->addr_len;
+	memcpy(arp_ptr, &sip, 4);
+	return 0;
+}
+
+
+/*
+ * Accept an skbuff from net_device layer and add the payload onto
+ * kgdb buffer
+ *
+ * When the kgdb stub routine read_char() is called it draws characters
+ * out of the buffer until it is empty and then polls the hardware.
+ *
+ * Return value of NET_RX_DROP means skb was used by this function.
+ * NET_RX_SUCCESS indicates this function didn't use it.
+
+ * Be prepared to respond to ARP requests. Let the caller also handle
+ * them if debugger is not active. We'll respond to the ARP request when
+ * a debugging session begins. It's necessary to respond to the request as 
the
+ * debugging session may begin even before kernel has a chance finish the
+ * response.
+ */
+int
+kgdb_net_interrupt(struct sk_buff *skb)
+{
+	unsigned char	chr;
+	struct iphdr	*iph = (struct iphdr*)skb->data;
+	struct udphdr	*udph= (struct udphdr*)(skb->data+(iph->ihl<<2));
+	unsigned char	*data = (unsigned char *) udph + sizeof(struct udphdr);
+	int		len;
+	int		i;
+
+	if (!kgdb_initialized || !kgdb_netdevice) {
+		goto out;
+	}
+	if (skb->protocol == __constant_htons(ETH_P_ARP) && !send_skb) {
+		make_arp_request(skb);
+		goto out;
+	}
+	if (iph->protocol != IPPROTO_UDP ||
+		be16_to_cpu(udph->dest) != kgdb_listenport) 
+		goto out;
+
+	kgdb_sendport = be16_to_cpu(udph->source);
+
+	len = (be16_to_cpu(iph->tot_len) -
+	       (sizeof(struct udphdr) + sizeof(struct iphdr)));
+
+	for (i = 0; i < len; i++) {
+		chr = *data++;
+		if (chr == 3)
+		{
+			if (!atomic_read(&debugger_active)) {
+				breakpoint();
+			}
+			continue;
+		}
+		if (atomic_read(&kgdb_buf_in_cnt) >= GDB_BUF_SIZE) {
+			/* buffer overflow, clear it */
+			kgdb_buf_in_inx = 0;
+			atomic_set(&kgdb_buf_in_cnt, 0);
+			kgdb_buf_out_inx = 0;
+			break;
+		}
+		kgdb_buf[kgdb_buf_in_inx++] = chr;
+		kgdb_buf_in_inx &= (GDB_BUF_SIZE - 1);
+		atomic_inc(&kgdb_buf_in_cnt) ;
+	}
+	return NET_RX_DROP;
+
+out:
+	if (atomic_read(&debugger_active))
+		return NET_RX_DROP;
+	return NET_RX_SUCCESS;
+}
+
+/*
+ * Initializes ethernet interface to kgdb.
+ * Searches the device list and finds the device specified on kernel command
+ * line.
+ * Finds the irq handler for the device and saves its reference.
+ * Initializes kgdbeth data structures.
+ */
+
+int
+kgdbeth_hook(void)
+{
+	extern void kgdb_respond_ok(void);
+	struct irqaction *ia_ptr;
+	int i;
+
+	sprintf(kgdb_netdevname, "eth%d", kgdb_eth);
+
+	for (kgdb_netdevice = dev_base;
+		kgdb_netdevice != NULL;
+		kgdb_netdevice = kgdb_netdevice->next) {
+		if (strncmp(kgdb_netdevice->name, kgdb_netdevname, IFNAMSIZ) == 0) {
+			break;
+		}
+	}
+	if (!kgdb_netdevice) {
+		printk("kgdbeth: Unable to find interface %s\n",
+				kgdb_netdevname);
+		return -ENODEV;
+	}
+	if (!(kgdb_netdevice->flags & IFF_UP)) {
+		return -EINVAL;
+	}
+	ia_ptr = irq_desc[kgdb_netdevice->irq].action;
+	while (ia_ptr) {
+		if (!strncmp(kgdb_netdevname, ia_ptr->name, IFNAMSIZ)) {
+			kgdbeth_irqhandler = ia_ptr->handler;
+			break;
+		}
+		ia_ptr = ia_ptr->next;
+	}
+	if (!kgdbeth_irqhandler) {
+		printk("kgdbeth: Interface %s doesn't have an interrupt"
+			" handler cannot use it\n", kgdb_netdevname);
+		return -EINVAL;
+	}
+	for (i = 0; i < NUM_SENDBUF; i++) {
+		send_skbs[i] = kmalloc(sizeof (struct sk_buff), GFP_KERNEL);
+		send_bufs[i] = kmalloc(SEND_BUFLEN, GFP_KERNEL);
+		if (!send_skbs[i] || !send_bufs[i]) {
+			printk("kgdbeth: not enough memory\n");
+			return -ENOMEM;
+		}
+		atomic_set(&(send_skbs[i]->users), 1);
+	}
+
+
+	return 0;
+}
+
+/*
+ * kgdbeth_read_char
+ *
+ * This is a GDB stub routine.  It waits for a character from the
+ * ethernet interface and then returns it.
+ */
+static int
+kgdbeth_read_char(void)
+{
+	int	chr;
+
+	while ((chr = read_char()) < 0) {
+		if (send_skb) {
+			kgdb_eth_reply_arp();
+		}
+		(*kgdbeth_irqhandler)(kgdb_netdevice->irq,
+				      (void *)kgdb_netdevice, 0);
+	}
+	return chr;
+}
+
+/*
+ * Hold onto the xmitlock and keep holding till the session ends.
+ * Disable device irq and keep it disabled till this session ends.
+ * Respond to last arp request we have received. It may not not have be
+ * responded yet.
+ */
+static void kgdbeth_begin_session(void) {
+	kgdbeth_holdxlock();
+	disable_irq(kgdb_netdevice->irq);
+	kgdb_eth_reply_arp();
+}
+
+static void kgdbeth_end_session(void)
+{
+	enable_irq(kgdb_netdevice->irq);
+	kgdbeth_relxlock();
+}
+
+struct kgdb_serial kgdbeth_serial = {
+	.chunksize = CHUNKSIZE,
+	.read_char = kgdbeth_read_char,
+	.write_char = kgdbeth_write_char,
+	.hook = kgdbeth_hook,
+	.flush = kgdbeth_flush,
+	.begin_session = kgdbeth_begin_session,
+	.end_session = kgdbeth_end_session,
+};
+
+static int __init parse_hw_addr(char **ptr, unsigned char *addr,
+		unsigned char delimiter)
+{
+	int  i = 0;
+
+	while(**ptr != delimiter)
+	{
+		unsigned int c;
+
+		if (sscanf(*ptr, "%x", &c) != 1) {
+			return 1;
+		}
+		addr[i++] = c;
+		do
+			(*ptr)++;
+		while((**ptr != delimiter) && (*(*ptr -1) != ':'));
+		if (i > 6)
+			return -EINVAL;
+	}
+	if (i != 6)
+		return -EINVAL;
+	return 0;
+}
+
+int kgdbeth_thread(void *data)
+{
+	struct net_device *ndev = (struct net_device *)data;
+	daemonize("kgdbeth");
+	while (!ndev->ip_ptr) {
+		schedule();
+	}
+	debugger_entry();
+	return 0;
+}
+
+int kgdbeth_event(struct notifier_block * self, unsigned long val, void * 
data)
+{
+	if (strcmp(((struct net_device *)data)->name, kgdb_netdevname)) {
+		goto out;
+	}
+	if (val!= NETDEV_UP)
+		goto out;
+	kernel_thread(kgdbeth_thread, data, CLONE_KERNEL);
+
+out:
+	return NOTIFY_DONE;
+}
+static struct notifier_block nb = {
+       .notifier_call = kgdbeth_event,
+};
+
+/*
+ * Syntax for this cmdline option is
+ * kgdbeth=interfacenum,localmac,listenport,remoteip,remotemac
+ */
+
+static int __init kgdbeth_opt(char *str)
+{
+	char ipaddrstr[16];
+	char *ipaddrptr = ipaddrstr;
+	extern int register_netdevice_notifier(struct notifier_block *nb);
+
+
+	if (register_netdevice_notifier(&nb)) {
+		printk("KGDB_ETH: couldn't register notifier\n");
+		return 0;
+	}
+
+	/* interfacenum */
+	if (*str < '0' || *str > '9')
+		goto errout;
+	kgdb_eth = *str - '0';
+	str++;
+	if (*str != ',')
+		goto errout;
+	str++;
+
+	/* localmac */
+	if (parse_hw_addr(&str, kgdb_localmac, ','))
+		goto errout;
+	str++;
+
+	/* port */
+	kgdb_listenport = simple_strtoul(str, &str, 10);
+
+	if (*str != ',')
+		goto errout;
+	str++;
+
+	/* remoteip */
+	while (*str != ',') {
+		if (!*str)
+			goto errout;
+		*ipaddrptr = *str;
+		str++;
+		ipaddrptr++;
+	}
+	str++;
+	*ipaddrptr = '\0';
+	kgdb_remoteip = in_aton(ipaddrstr);
+
+	/* remotemac */
+	if (parse_hw_addr(&str, kgdb_remotemac, '\0'))
+		goto errout;
+
+	kgdb_serial = &kgdbeth_serial;
+	return 1;
+
+errout:
+	printk("Invalid syntax for option kgdbeth=\n");
+	return 0;
+}
+
+__setup("kgdbeth=", kgdbeth_opt);
diff -Naurp linux-2.6.1/drivers/net/Makefile 
linux-2.6.1-kgdb-2.0.5-eth/drivers/net/Makefile
--- linux-2.6.1/drivers/net/Makefile	2003-11-24 07:01:27.000000000 +0530
+++ linux-2.6.1-kgdb-2.0.5-eth/drivers/net/Makefile	2004-01-12 
19:11:13.000000000 +0530
@@ -32,6 +32,8 @@ obj-$(CONFIG_BMAC) += bmac.o
 
 obj-$(CONFIG_OAKNET) += oaknet.o 8390.o
 
+obj-$(CONFIG_KGDB_ETH) += kgdb_eth.o
+
 obj-$(CONFIG_DGRS) += dgrs.o
 obj-$(CONFIG_RCPCI) += rcpci.o
 obj-$(CONFIG_VORTEX) += 3c59x.o
diff -Naurp linux-2.6.1/net/core/dev.c 
linux-2.6.1-kgdb-2.0.5-eth/net/core/dev.c
--- linux-2.6.1/net/core/dev.c	2004-01-10 11:01:50.000000000 +0530
+++ linux-2.6.1-kgdb-2.0.5-eth/net/core/dev.c	2004-01-20 14:27:38.000000000 
+0530
@@ -1380,7 +1380,6 @@ static void sample_queue(unsigned long d
 }
 #endif
 
-
 /**
  *	netif_rx	-	post buffer to the network code
  *	@skb: buffer to post
@@ -1404,6 +1403,15 @@ int netif_rx(struct sk_buff *skb)
 	int this_cpu;
 	struct softnet_data *queue;
 	unsigned long flags;
+	int ret;
+	int kgdb_net_interrupt(struct sk_buff *skb);
+
+#ifdef CONFIG_KGDB_ETH
+	/* See if kgdb_eth wants this packet */
+	if ((ret = kgdb_net_interrupt(skb)) == NET_RX_DROP) {
+		return ret;
+	}
+#endif
 
 	if (!skb->stamp.tv_sec)
 		do_gettimeofday(&skb->stamp);
diff -Naurp linux-2.6.1/net/core/skbuff.c 
linux-2.6.1-kgdb-2.0.5-eth/net/core/skbuff.c
--- linux-2.6.1/net/core/skbuff.c	2003-11-24 07:02:36.000000000 +0530
+++ linux-2.6.1-kgdb-2.0.5-eth/net/core/skbuff.c	2004-01-20 16:10:42.000000000 
+0530
@@ -55,6 +55,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/init.h>
 #include <linux/highmem.h>
+#include <linux/debugger.h>
 
 #include <net/protocol.h>
 #include <net/dst.h>
@@ -126,6 +127,11 @@ struct sk_buff *alloc_skb(unsigned int s
 {
 	struct sk_buff *skb;
 	u8 *data;
+	struct sk_buff *kgdbeth_alloc_skb(int size);
+
+	if (atomic_read(&debugger_active)) {
+		return kgdbeth_alloc_skb(size);
+	}
 
 	/* Get the HEAD */
 	skb = kmem_cache_alloc(skbuff_head_cache,