[deliverable/linux.git] / net / core / netpoll.c

/*
 * Common framework for low-level network console, dump, and debugger code
 *
 * Sep 8 2003  Matt Mackall <mpm@selenic.com>
 *
 * based on the netconsole code from:
 *
 * Copyright (C) 2001  Ingo Molnar <mingo@redhat.com>
 * Copyright (C) 2002  Red Hat, Inc.
 */

#include <linux/smp_lock.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/string.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/inet.h>
#include <linux/interrupt.h>
#include <linux/netpoll.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <asm/unaligned.h>

/*
 * We maintain a small pool of fully-sized skbs, to make sure the
 * message gets out even in extreme OOM situations.
 */

#define MAX_UDP_CHUNK 1460
#define MAX_SKBS 32
#define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
#define MAX_RETRIES 20000

static DEFINE_SPINLOCK(skb_list_lock);
static int nr_skbs;
static struct sk_buff *skbs;

static DEFINE_SPINLOCK(queue_lock);
static int queue_depth;
static struct sk_buff *queue_head, *queue_tail;

static atomic_t trapped;

#define NETPOLL_RX_ENABLED  1
#define NETPOLL_RX_DROP     2

#define MAX_SKB_SIZE \
		(MAX_UDP_CHUNK + sizeof(struct udphdr) + \
				sizeof(struct iphdr) + sizeof(struct ethhdr))

static void zap_completion_queue(void);

static void queue_process(void *p)
{
	unsigned long flags;
	struct sk_buff *skb;

	while (queue_head) {
		spin_lock_irqsave(&queue_lock, flags);

		skb = queue_head;
		queue_head = skb->next;
		if (skb == queue_tail)
			queue_head = NULL;

		queue_depth--;

		spin_unlock_irqrestore(&queue_lock, flags);

		dev_queue_xmit(skb);
	}
}

static DECLARE_WORK(send_queue, queue_process, NULL);

void netpoll_queue(struct sk_buff *skb)
{
	unsigned long flags;

	if (queue_depth == MAX_QUEUE_DEPTH) {
		__kfree_skb(skb);
		return;
	}

	spin_lock_irqsave(&queue_lock, flags);
	if (!queue_head)
		queue_head = skb;
	else
		queue_tail->next = skb;
	queue_tail = skb;
	queue_depth++;
	spin_unlock_irqrestore(&queue_lock, flags);

	schedule_work(&send_queue);
}

static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
			     unsigned short ulen, u32 saddr, u32 daddr)
{
	unsigned int psum;

	if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
		return 0;

	psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);

	if (skb->ip_summed == CHECKSUM_HW &&
	    !(u16)csum_fold(csum_add(psum, skb->csum)))
		return 0;

	skb->csum = psum;

	return __skb_checksum_complete(skb);
}

/*
 * Check whether delayed processing was scheduled for our NIC. If so,
 * we attempt to grab the poll lock and use ->poll() to pump the card.
 * If this fails, either we've recursed in ->poll() or it's already
 * running on another CPU.
 *
 * Note: we don't mask interrupts with this lock because we're using
 * trylock here and interrupts are already disabled in the softirq
 * case. Further, we test the poll_owner to avoid recursion on UP
 * systems where the lock doesn't exist.
 *
 * In cases where there is bi-directional communications, reading only
 * one message at a time can lead to packets being dropped by the
 * network adapter, forcing superfluous retries and possibly timeouts.
 * Thus, we set our budget to greater than 1.
 */
static void poll_napi(struct netpoll *np)
{
	struct netpoll_info *npinfo = np->dev->npinfo;
	int budget = 16;

	if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
	    npinfo->poll_owner != smp_processor_id() &&
	    spin_trylock(&npinfo->poll_lock)) {
		npinfo->rx_flags |= NETPOLL_RX_DROP;
		atomic_inc(&trapped);

		np->dev->poll(np->dev, &budget);

		atomic_dec(&trapped);
		npinfo->rx_flags &= ~NETPOLL_RX_DROP;
		spin_unlock(&npinfo->poll_lock);
	}
}

void netpoll_poll(struct netpoll *np)
{
	if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
		return;

	/* Process pending work on NIC */
	np->dev->poll_controller(np->dev);
	if (np->dev->poll)
		poll_napi(np);

	zap_completion_queue();
}

static void refill_skbs(void)
{
	struct sk_buff *skb;
	unsigned long flags;

	spin_lock_irqsave(&skb_list_lock, flags);
	while (nr_skbs < MAX_SKBS) {
		skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
		if (!skb)
			break;

		skb->next = skbs;
		skbs = skb;
		nr_skbs++;
	}
	spin_unlock_irqrestore(&skb_list_lock, flags);
}

static void zap_completion_queue(void)
{
	unsigned long flags;
	struct softnet_data *sd = &get_cpu_var(softnet_data);

	if (sd->completion_queue) {
		struct sk_buff *clist;

		local_irq_save(flags);
		clist = sd->completion_queue;
		sd->completion_queue = NULL;
		local_irq_restore(flags);

		while (clist != NULL) {
			struct sk_buff *skb = clist;
			clist = clist->next;
			if(skb->destructor)
				dev_kfree_skb_any(skb); /* put this one back */
			else
				__kfree_skb(skb);
		}
	}

	put_cpu_var(softnet_data);
}

static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve)
{
	int once = 1, count = 0;
	unsigned long flags;
	struct sk_buff *skb = NULL;

	zap_completion_queue();
repeat:
	if (nr_skbs < MAX_SKBS)
		refill_skbs();

	skb = alloc_skb(len, GFP_ATOMIC);

	if (!skb) {
		spin_lock_irqsave(&skb_list_lock, flags);
		skb = skbs;
		if (skb) {
			skbs = skb->next;
			skb->next = NULL;
			nr_skbs--;
		}
		spin_unlock_irqrestore(&skb_list_lock, flags);
	}

	if(!skb) {
		count++;
		if (once && (count == 1000000)) {
			printk("out of netpoll skbs!\n");
			once = 0;
		}
		netpoll_poll(np);
		goto repeat;
	}

	atomic_set(&skb->users, 1);
	skb_reserve(skb, reserve);
	return skb;
}

static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
	int status;
	struct netpoll_info *npinfo;

	if (!np || !np->dev || !netif_running(np->dev)) {
		__kfree_skb(skb);
		return;
	}

	npinfo = np->dev->npinfo;

	/* avoid recursion */
	if (npinfo->poll_owner == smp_processor_id() ||
	    np->dev->xmit_lock_owner == smp_processor_id()) {
		if (np->drop)
			np->drop(skb);
		else
			__kfree_skb(skb);
		return;
	}

	do {
		npinfo->tries--;
		spin_lock(&np->dev->xmit_lock);
		np->dev->xmit_lock_owner = smp_processor_id();

		/*
		 * network drivers do not expect to be called if the queue is
		 * stopped.
		 */
		if (netif_queue_stopped(np->dev)) {
			np->dev->xmit_lock_owner = -1;
			spin_unlock(&np->dev->xmit_lock);
			netpoll_poll(np);
			udelay(50);
			continue;
		}

		status = np->dev->hard_start_xmit(skb, np->dev);
		np->dev->xmit_lock_owner = -1;
		spin_unlock(&np->dev->xmit_lock);

		/* success */
		if(!status) {
			npinfo->tries = MAX_RETRIES; /* reset */
			return;
		}

		/* transmit busy */
		netpoll_poll(np);
		udelay(50);
	} while (npinfo->tries > 0);
}

void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
{
	int total_len, eth_len, ip_len, udp_len;
	struct sk_buff *skb;
	struct udphdr *udph;
	struct iphdr *iph;
	struct ethhdr *eth;

	udp_len = len + sizeof(*udph);
	ip_len = eth_len = udp_len + sizeof(*iph);
	total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;

	skb = find_skb(np, total_len, total_len - len);
	if (!skb)
		return;

	memcpy(skb->data, msg, len);
	skb->len += len;

	udph = (struct udphdr *) skb_push(skb, sizeof(*udph));
	udph->source = htons(np->local_port);
	udph->dest = htons(np->remote_port);
	udph->len = htons(udp_len);
	udph->check = 0;

	iph = (struct iphdr *)skb_push(skb, sizeof(*iph));

	/* iph->version = 4; iph->ihl = 5; */
	put_unaligned(0x45, (unsigned char *)iph);
	iph->tos      = 0;
	put_unaligned(htons(ip_len), &(iph->tot_len));
	iph->id       = 0;
	iph->frag_off = 0;
	iph->ttl      = 64;
	iph->protocol = IPPROTO_UDP;
	iph->check    = 0;
	put_unaligned(htonl(np->local_ip), &(iph->saddr));
	put_unaligned(htonl(np->remote_ip), &(iph->daddr));
	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, np->local_mac, 6);
	memcpy(eth->h_dest, np->remote_mac, 6);

	skb->dev = np->dev;

	netpoll_send_skb(np, skb);
}

static void arp_reply(struct sk_buff *skb)
{
	struct netpoll_info *npinfo = skb->dev->npinfo;
	struct arphdr *arp;
	unsigned char *arp_ptr;
	int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
	u32 sip, tip;
	struct sk_buff *send_skb;
	struct netpoll *np = NULL;

	if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
		np = npinfo->rx_np;
	if (!np)
		return;

	/* No arp on this interface */
	if (skb->dev->flags & IFF_NOARP)
		return;

	if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
				 (2 * skb->dev->addr_len) +
				 (2 * sizeof(u32)))))
		return;

	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) ||
	    arp->ar_op != htons(ARPOP_REQUEST))
		return;

	arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len;
	memcpy(&sip, arp_ptr, 4);
	arp_ptr += 4 + skb->dev->addr_len;
	memcpy(&tip, arp_ptr, 4);

	/* Should we ignore arp? */
	if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
		return;

	size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
	send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
			    LL_RESERVED_SPACE(np->dev));

	if (!send_skb)
		return;

	send_skb->nh.raw = send_skb->data;
	arp = (struct arphdr *) skb_put(send_skb, size);
	send_skb->dev = skb->dev;
	send_skb->protocol = htons(ETH_P_ARP);

	/* Fill the device header for the ARP frame */

	if (np->dev->hard_header &&
	    np->dev->hard_header(send_skb, skb->dev, ptype,
				       np->remote_mac, np->local_mac,
				       send_skb->len) < 0) {
		kfree_skb(send_skb);
		return;
	}

	/*
	 * 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(np->dev->type);
	arp->ar_pro = htons(ETH_P_IP);
	arp->ar_hln = np->dev->addr_len;
	arp->ar_pln = 4;
	arp->ar_op = htons(type);

	arp_ptr=(unsigned char *)(arp + 1);
	memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
	arp_ptr += np->dev->addr_len;
	memcpy(arp_ptr, &tip, 4);
	arp_ptr += 4;
	memcpy(arp_ptr, np->remote_mac, np->dev->addr_len);
	arp_ptr += np->dev->addr_len;
	memcpy(arp_ptr, &sip, 4);

	netpoll_send_skb(np, send_skb);
}

int __netpoll_rx(struct sk_buff *skb)
{
	int proto, len, ulen;
	struct iphdr *iph;
	struct udphdr *uh;
	struct netpoll *np = skb->dev->npinfo->rx_np;

	if (!np)
		goto out;
	if (skb->dev->type != ARPHRD_ETHER)
		goto out;

	/* check if netpoll clients need ARP */
	if (skb->protocol == __constant_htons(ETH_P_ARP) &&
	    atomic_read(&trapped)) {
		arp_reply(skb);
		return 1;
	}

	proto = ntohs(eth_hdr(skb)->h_proto);
	if (proto != ETH_P_IP)
		goto out;
	if (skb->pkt_type == PACKET_OTHERHOST)
		goto out;
	if (skb_shared(skb))
		goto out;

	iph = (struct iphdr *)skb->data;
	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
		goto out;
	if (iph->ihl < 5 || iph->version != 4)
		goto out;
	if (!pskb_may_pull(skb, iph->ihl*4))
		goto out;
	if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
		goto out;

	len = ntohs(iph->tot_len);
	if (skb->len < len || len < iph->ihl*4)
		goto out;

	if (iph->protocol != IPPROTO_UDP)
		goto out;

	len -= iph->ihl*4;
	uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
	ulen = ntohs(uh->len);

	if (ulen != len)
		goto out;
	if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
		goto out;
	if (np->local_ip && np->local_ip != ntohl(iph->daddr))
		goto out;
	if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
		goto out;
	if (np->local_port && np->local_port != ntohs(uh->dest))
		goto out;

	np->rx_hook(np, ntohs(uh->source),
		    (char *)(uh+1),
		    ulen - sizeof(struct udphdr));

	kfree_skb(skb);
	return 1;

out:
	if (atomic_read(&trapped)) {
		kfree_skb(skb);
		return 1;
	}

	return 0;
}

int netpoll_parse_options(struct netpoll *np, char *opt)
{
	char *cur=opt, *delim;

	if(*cur != '@') {
		if ((delim = strchr(cur, '@')) == NULL)
			goto parse_failed;
		*delim=0;
		np->local_port=simple_strtol(cur, NULL, 10);
		cur=delim;
	}
	cur++;
	printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port);

	if(*cur != '/') {
		if ((delim = strchr(cur, '/')) == NULL)
			goto parse_failed;
		*delim=0;
		np->local_ip=ntohl(in_aton(cur));
		cur=delim;

		printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
		       np->name, HIPQUAD(np->local_ip));
	}
	cur++;

	if ( *cur != ',') {
		/* parse out dev name */
		if ((delim = strchr(cur, ',')) == NULL)
			goto parse_failed;
		*delim=0;
		strlcpy(np->dev_name, cur, sizeof(np->dev_name));
		cur=delim;
	}
	cur++;

	printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name);

	if ( *cur != '@' ) {
		/* dst port */
		if ((delim = strchr(cur, '@')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_port=simple_strtol(cur, NULL, 10);
		cur=delim;
	}
	cur++;
	printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port);

	/* dst ip */
	if ((delim = strchr(cur, '/')) == NULL)
		goto parse_failed;
	*delim=0;
	np->remote_ip=ntohl(in_aton(cur));
	cur=delim+1;

	printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
		       np->name, HIPQUAD(np->remote_ip));

	if( *cur != 0 )
	{
		/* MAC address */
		if ((delim = strchr(cur, ':')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_mac[0]=simple_strtol(cur, NULL, 16);
		cur=delim+1;
		if ((delim = strchr(cur, ':')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_mac[1]=simple_strtol(cur, NULL, 16);
		cur=delim+1;
		if ((delim = strchr(cur, ':')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_mac[2]=simple_strtol(cur, NULL, 16);
		cur=delim+1;
		if ((delim = strchr(cur, ':')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_mac[3]=simple_strtol(cur, NULL, 16);
		cur=delim+1;
		if ((delim = strchr(cur, ':')) == NULL)
			goto parse_failed;
		*delim=0;
		np->remote_mac[4]=simple_strtol(cur, NULL, 16);
		cur=delim+1;
		np->remote_mac[5]=simple_strtol(cur, NULL, 16);
	}

	printk(KERN_INFO "%s: remote ethernet address "
	       "%02x:%02x:%02x:%02x:%02x:%02x\n",
	       np->name,
	       np->remote_mac[0],
	       np->remote_mac[1],
	       np->remote_mac[2],
	       np->remote_mac[3],
	       np->remote_mac[4],
	       np->remote_mac[5]);

	return 0;

 parse_failed:
	printk(KERN_INFO "%s: couldn't parse config at %s!\n",
	       np->name, cur);
	return -1;
}

int netpoll_setup(struct netpoll *np)
{
	struct net_device *ndev = NULL;
	struct in_device *in_dev;
	struct netpoll_info *npinfo;
	unsigned long flags;

	if (np->dev_name)
		ndev = dev_get_by_name(np->dev_name);
	if (!ndev) {
		printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
		       np->name, np->dev_name);
		return -1;
	}

	np->dev = ndev;
	if (!ndev->npinfo) {
		npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
		if (!npinfo)
			goto release;

		npinfo->rx_flags = 0;
		npinfo->rx_np = NULL;
		spin_lock_init(&npinfo->poll_lock);
		npinfo->poll_owner = -1;
		npinfo->tries = MAX_RETRIES;
		spin_lock_init(&npinfo->rx_lock);
	} else
		npinfo = ndev->npinfo;

	if (!ndev->poll_controller) {
		printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
		       np->name, np->dev_name);
		goto release;
	}

	if (!netif_running(ndev)) {
		unsigned long atmost, atleast;

		printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
		       np->name, np->dev_name);

		rtnl_shlock();
		if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) {
			printk(KERN_ERR "%s: failed to open %s\n",
			       np->name, np->dev_name);
			rtnl_shunlock();
			goto release;
		}
		rtnl_shunlock();

		atleast = jiffies + HZ/10;
 		atmost = jiffies + 4*HZ;
		while (!netif_carrier_ok(ndev)) {
			if (time_after(jiffies, atmost)) {
				printk(KERN_NOTICE
				       "%s: timeout waiting for carrier\n",
				       np->name);
				break;
			}
			cond_resched();
		}

		/* If carrier appears to come up instantly, we don't
		 * trust it and pause so that we don't pump all our
		 * queued console messages into the bitbucket.
		 */

		if (time_before(jiffies, atleast)) {
			printk(KERN_NOTICE "%s: carrier detect appears"
			       " untrustworthy, waiting 4 seconds\n",
			       np->name);
			msleep(4000);
		}
	}

	if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
		memcpy(np->local_mac, ndev->dev_addr, 6);

	if (!np->local_ip) {
		rcu_read_lock();
		in_dev = __in_dev_get_rcu(ndev);

		if (!in_dev || !in_dev->ifa_list) {
			rcu_read_unlock();
			printk(KERN_ERR "%s: no IP address for %s, aborting\n",
			       np->name, np->dev_name);
			goto release;
		}

		np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
		rcu_read_unlock();
		printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
		       np->name, HIPQUAD(np->local_ip));
	}

	if (np->rx_hook) {
		spin_lock_irqsave(&npinfo->rx_lock, flags);
		npinfo->rx_flags |= NETPOLL_RX_ENABLED;
		npinfo->rx_np = np;
		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
	}

	/* fill up the skb queue */
	refill_skbs();

	/* last thing to do is link it to the net device structure */
	ndev->npinfo = npinfo;

	/* avoid racing with NAPI reading npinfo */
	synchronize_rcu();

	return 0;

 release:
	if (!ndev->npinfo)
		kfree(npinfo);
	np->dev = NULL;
	dev_put(ndev);
	return -1;
}

void netpoll_cleanup(struct netpoll *np)
{
	struct netpoll_info *npinfo;
	unsigned long flags;

	if (np->dev) {
		npinfo = np->dev->npinfo;
		if (npinfo && npinfo->rx_np == np) {
			spin_lock_irqsave(&npinfo->rx_lock, flags);
			npinfo->rx_np = NULL;
			npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
			spin_unlock_irqrestore(&npinfo->rx_lock, flags);
		}
		dev_put(np->dev);
	}

	np->dev = NULL;
}

int netpoll_trap(void)
{
	return atomic_read(&trapped);
}

void netpoll_set_trap(int trap)
{
	if (trap)
		atomic_inc(&trapped);
	else
		atomic_dec(&trapped);
}

EXPORT_SYMBOL(netpoll_set_trap);
EXPORT_SYMBOL(netpoll_trap);
EXPORT_SYMBOL(netpoll_parse_options);
EXPORT_SYMBOL(netpoll_setup);
EXPORT_SYMBOL(netpoll_cleanup);
EXPORT_SYMBOL(netpoll_send_udp);
EXPORT_SYMBOL(netpoll_poll);
EXPORT_SYMBOL(netpoll_queue);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Common framework for low-level network console, dump, and debugger code
	3	*
	4	* Sep 8 2003 Matt Mackall <mpm@selenic.com>
	5	*
	6	* based on the netconsole code from:
	7	*
	8	* Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
	9	* Copyright (C) 2002 Red Hat, Inc.
	10	*/
	11
	12	#include <linux/smp_lock.h>
	13	#include <linux/netdevice.h>
	14	#include <linux/etherdevice.h>
	15	#include <linux/string.h>
14c85021	16	#include <linux/if_arp.h>
1da177e4 LT	17	#include <linux/inetdevice.h>
	18	#include <linux/inet.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/netpoll.h>
	21	#include <linux/sched.h>
	22	#include <linux/delay.h>
	23	#include <linux/rcupdate.h>
	24	#include <linux/workqueue.h>
	25	#include <net/tcp.h>
	26	#include <net/udp.h>
	27	#include <asm/unaligned.h>
	28
	29	/*
	30	* We maintain a small pool of fully-sized skbs, to make sure the
	31	* message gets out even in extreme OOM situations.
	32	*/
	33
	34	#define MAX_UDP_CHUNK 1460
	35	#define MAX_SKBS 32
	36	#define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
0db1d6fc	37	#define MAX_RETRIES 20000
1da177e4 LT	38
	39	static DEFINE_SPINLOCK(skb_list_lock);
	40	static int nr_skbs;
	41	static struct sk_buff *skbs;
	42
	43	static DEFINE_SPINLOCK(queue_lock);
	44	static int queue_depth;
	45	static struct sk_buff queue_head, queue_tail;
	46
	47	static atomic_t trapped;
	48
	49	#define NETPOLL_RX_ENABLED 1
	50	#define NETPOLL_RX_DROP 2
	51
	52	#define MAX_SKB_SIZE \
	53	(MAX_UDP_CHUNK + sizeof(struct udphdr) + \
	54	sizeof(struct iphdr) + sizeof(struct ethhdr))
	55
	56	static void zap_completion_queue(void);
	57
	58	static void queue_process(void *p)
	59	{
	60	unsigned long flags;
	61	struct sk_buff *skb;
	62
	63	while (queue_head) {
	64	spin_lock_irqsave(&queue_lock, flags);
	65
	66	skb = queue_head;
	67	queue_head = skb->next;
	68	if (skb == queue_tail)
	69	queue_head = NULL;
	70
	71	queue_depth--;
	72
	73	spin_unlock_irqrestore(&queue_lock, flags);
	74
	75	dev_queue_xmit(skb);
	76	}
	77	}
	78
	79	static DECLARE_WORK(send_queue, queue_process, NULL);
	80
	81	void netpoll_queue(struct sk_buff *skb)
	82	{
	83	unsigned long flags;
	84
	85	if (queue_depth == MAX_QUEUE_DEPTH) {
	86	__kfree_skb(skb);
	87	return;
	88	}
	89
	90	spin_lock_irqsave(&queue_lock, flags);
	91	if (!queue_head)
	92	queue_head = skb;
	93	else
	94	queue_tail->next = skb;
	95	queue_tail = skb;
	96	queue_depth++;
	97	spin_unlock_irqrestore(&queue_lock, flags);
	98
	99	schedule_work(&send_queue);
	100	}
	101
102	static int checksum_udp(struct sk_buff skb, struct udphdr uh,
103	unsigned short ulen, u32 saddr, u32 daddr)
104	{
fb286bb2 HX	105	unsigned int psum;
	106
	107	if (uh->check == 0 \|\| skb->ip_summed == CHECKSUM_UNNECESSARY)
1da177e4 LT	108	return 0;
1da177e4 LT	109
fb286bb2 HX	110	psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
	111
	112	if (skb->ip_summed == CHECKSUM_HW &&
	113	!(u16)csum_fold(csum_add(psum, skb->csum)))
	114	return 0;
1da177e4	115
fb286bb2	116	skb->csum = psum;
1da177e4	117
fb286bb2	118	return __skb_checksum_complete(skb);
1da177e4 LT	119	}
	120
	121	/*
	122	* Check whether delayed processing was scheduled for our NIC. If so,
	123	* we attempt to grab the poll lock and use ->poll() to pump the card.
	124	* If this fails, either we've recursed in ->poll() or it's already
	125	* running on another CPU.
	126	*
	127	* Note: we don't mask interrupts with this lock because we're using
	128	* trylock here and interrupts are already disabled in the softirq
	129	* case. Further, we test the poll_owner to avoid recursion on UP
	130	* systems where the lock doesn't exist.
	131	*
	132	* In cases where there is bi-directional communications, reading only
	133	* one message at a time can lead to packets being dropped by the
	134	* network adapter, forcing superfluous retries and possibly timeouts.
	135	* Thus, we set our budget to greater than 1.
	136	*/
	137	static void poll_napi(struct netpoll *np)
	138	{
115c1d6e	139	struct netpoll_info *npinfo = np->dev->npinfo;
1da177e4 LT	140	int budget = 16;
	141
	142	if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
115c1d6e JM	143	npinfo->poll_owner != smp_processor_id() &&
	144	spin_trylock(&npinfo->poll_lock)) {
	145	npinfo->rx_flags \|= NETPOLL_RX_DROP;
1da177e4 LT	146	atomic_inc(&trapped);
	147
	148	np->dev->poll(np->dev, &budget);
	149
	150	atomic_dec(&trapped);
115c1d6e JM	151	npinfo->rx_flags &= ~NETPOLL_RX_DROP;
115c1d6e JM	152	spin_unlock(&npinfo->poll_lock);
1da177e4 LT	153	}
	154	}
	155
	156	void netpoll_poll(struct netpoll *np)
	157	{
	158	if(!np->dev \|\| !netif_running(np->dev) \|\| !np->dev->poll_controller)
	159	return;
	160
	161	/* Process pending work on NIC */
	162	np->dev->poll_controller(np->dev);
	163	if (np->dev->poll)
	164	poll_napi(np);
	165
	166	zap_completion_queue();
	167	}
	168
	169	static void refill_skbs(void)
	170	{
	171	struct sk_buff *skb;
	172	unsigned long flags;
	173
	174	spin_lock_irqsave(&skb_list_lock, flags);
	175	while (nr_skbs < MAX_SKBS) {
	176	skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
	177	if (!skb)
	178	break;
	179
	180	skb->next = skbs;
	181	skbs = skb;
	182	nr_skbs++;
	183	}
	184	spin_unlock_irqrestore(&skb_list_lock, flags);
	185	}
	186
	187	static void zap_completion_queue(void)
	188	{
	189	unsigned long flags;
	190	struct softnet_data *sd = &get_cpu_var(softnet_data);
	191
	192	if (sd->completion_queue) {
	193	struct sk_buff *clist;
	194
	195	local_irq_save(flags);
	196	clist = sd->completion_queue;
	197	sd->completion_queue = NULL;
	198	local_irq_restore(flags);
	199
	200	while (clist != NULL) {
	201	struct sk_buff *skb = clist;
	202	clist = clist->next;
	203	if(skb->destructor)
	204	dev_kfree_skb_any(skb); /* put this one back */
	205	else
	206	__kfree_skb(skb);
	207	}
	208	}
	209
	210	put_cpu_var(softnet_data);
	211	}
	212
	213	static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve)
	214	{
	215	int once = 1, count = 0;
	216	unsigned long flags;
217	struct sk_buff *skb = NULL;
218
219	zap_completion_queue();
220	repeat:
221	if (nr_skbs < MAX_SKBS)
222	refill_skbs();
223
224	skb = alloc_skb(len, GFP_ATOMIC);
225
226	if (!skb) {
227	spin_lock_irqsave(&skb_list_lock, flags);
228	skb = skbs;
229	if (skb) {
230	skbs = skb->next;
231	skb->next = NULL;
232	nr_skbs--;
233	}
234	spin_unlock_irqrestore(&skb_list_lock, flags);
235	}
236
237	if(!skb) {
238	count++;
239	if (once && (count == 1000000)) {
240	printk("out of netpoll skbs!\n");
241	once = 0;
242	}
243	netpoll_poll(np);
244	goto repeat;
245	}
246
247	atomic_set(&skb->users, 1);
248	skb_reserve(skb, reserve);
249	return skb;
250	}
251
252	static void netpoll_send_skb(struct netpoll np, struct sk_buff skb)
253	{
254	int status;
115c1d6e	255	struct netpoll_info *npinfo;
1da177e4	256
f0d3459d	257	if (!np \|\| !np->dev \|\| !netif_running(np->dev)) {
1da177e4 LT	258	__kfree_skb(skb);
	259	return;
	260	}
	261
115c1d6e	262	npinfo = np->dev->npinfo;
f0d3459d MM	263
f0d3459d MM	264	/* avoid recursion */
115c1d6e JM	265	if (npinfo->poll_owner == smp_processor_id() \|\|
115c1d6e JM	266	np->dev->xmit_lock_owner == smp_processor_id()) {
1da177e4 LT	267	if (np->drop)
	268	np->drop(skb);
	269	else
	270	__kfree_skb(skb);
	271	return;
	272	}
	273
0db1d6fc MM	274	do {
0db1d6fc MM	275	npinfo->tries--;
f0d3459d MM	276	spin_lock(&np->dev->xmit_lock);
	277	np->dev->xmit_lock_owner = smp_processor_id();
	278
	279	/*
	280	* network drivers do not expect to be called if the queue is
	281	* stopped.
	282	*/
	283	if (netif_queue_stopped(np->dev)) {
	284	np->dev->xmit_lock_owner = -1;
	285	spin_unlock(&np->dev->xmit_lock);
	286	netpoll_poll(np);
0db1d6fc	287	udelay(50);
f0d3459d MM	288	continue;
f0d3459d MM	289	}
1da177e4	290
f0d3459d	291	status = np->dev->hard_start_xmit(skb, np->dev);
1da177e4 LT	292	np->dev->xmit_lock_owner = -1;
	293	spin_unlock(&np->dev->xmit_lock);
	294
f0d3459d	295	/* success */
0db1d6fc MM	296	if(!status) {
0db1d6fc MM	297	npinfo->tries = MAX_RETRIES; /* reset */
f0d3459d	298	return;
0db1d6fc	299	}
1da177e4	300
f0d3459d	301	/* transmit busy */
1da177e4	302	netpoll_poll(np);
0db1d6fc MM	303	udelay(50);
0db1d6fc MM	304	} while (npinfo->tries > 0);
1da177e4 LT	305	}
	306
	307	void netpoll_send_udp(struct netpoll np, const char msg, int len)
	308	{
	309	int total_len, eth_len, ip_len, udp_len;
	310	struct sk_buff *skb;
	311	struct udphdr *udph;
	312	struct iphdr *iph;
	313	struct ethhdr *eth;
	314
	315	udp_len = len + sizeof(*udph);
	316	ip_len = eth_len = udp_len + sizeof(*iph);
	317	total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
	318
	319	skb = find_skb(np, total_len, total_len - len);
	320	if (!skb)
	321	return;
	322
	323	memcpy(skb->data, msg, len);
	324	skb->len += len;
	325
	326	udph = (struct udphdr ) skb_push(skb, sizeof(udph));
	327	udph->source = htons(np->local_port);
	328	udph->dest = htons(np->remote_port);
	329	udph->len = htons(udp_len);
	330	udph->check = 0;
	331
	332	iph = (struct iphdr )skb_push(skb, sizeof(iph));
	333
	334	/* iph->version = 4; iph->ihl = 5; */
	335	put_unaligned(0x45, (unsigned char *)iph);
	336	iph->tos = 0;
	337	put_unaligned(htons(ip_len), &(iph->tot_len));
	338	iph->id = 0;
	339	iph->frag_off = 0;
	340	iph->ttl = 64;
	341	iph->protocol = IPPROTO_UDP;
	342	iph->check = 0;
	343	put_unaligned(htonl(np->local_ip), &(iph->saddr));
	344	put_unaligned(htonl(np->remote_ip), &(iph->daddr));
	345	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
	346
	347	eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
	348
	349	eth->h_proto = htons(ETH_P_IP);
	350	memcpy(eth->h_source, np->local_mac, 6);
	351	memcpy(eth->h_dest, np->remote_mac, 6);
	352
	353	skb->dev = np->dev;
	354
	355	netpoll_send_skb(np, skb);
	356	}
	357
	358	static void arp_reply(struct sk_buff *skb)
	359	{
115c1d6e	360	struct netpoll_info *npinfo = skb->dev->npinfo;
1da177e4 LT	361	struct arphdr *arp;
	362	unsigned char *arp_ptr;
	363	int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
	364	u32 sip, tip;
	365	struct sk_buff *send_skb;
115c1d6e	366	struct netpoll *np = NULL;
1da177e4	367
fbeec2e1 JM	368	if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
fbeec2e1 JM	369	np = npinfo->rx_np;
115c1d6e JM	370	if (!np)
115c1d6e JM	371	return;
1da177e4 LT	372
	373	/* No arp on this interface */
	374	if (skb->dev->flags & IFF_NOARP)
	375	return;
	376
	377	if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
	378	(2 * skb->dev->addr_len) +
	379	(2 * sizeof(u32)))))
	380	return;
	381
	382	skb->h.raw = skb->nh.raw = skb->data;
	383	arp = skb->nh.arph;
	384
	385	if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
	386	arp->ar_hrd != htons(ARPHRD_IEEE802)) \|\|
	387	arp->ar_pro != htons(ETH_P_IP) \|\|
	388	arp->ar_op != htons(ARPOP_REQUEST))
	389	return;
	390
	391	arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len;
	392	memcpy(&sip, arp_ptr, 4);
	393	arp_ptr += 4 + skb->dev->addr_len;
	394	memcpy(&tip, arp_ptr, 4);
	395
	396	/* Should we ignore arp? */
	397	if (tip != htonl(np->local_ip) \|\| LOOPBACK(tip) \|\| MULTICAST(tip))
	398	return;
	399
	400	size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
	401	send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
	402	LL_RESERVED_SPACE(np->dev));
	403
	404	if (!send_skb)
	405	return;
	406
	407	send_skb->nh.raw = send_skb->data;
	408	arp = (struct arphdr *) skb_put(send_skb, size);
	409	send_skb->dev = skb->dev;
	410	send_skb->protocol = htons(ETH_P_ARP);
	411
	412	/* Fill the device header for the ARP frame */
	413
	414	if (np->dev->hard_header &&
	415	np->dev->hard_header(send_skb, skb->dev, ptype,
	416	np->remote_mac, np->local_mac,
	417	send_skb->len) < 0) {
	418	kfree_skb(send_skb);
	419	return;
	420	}
	421
	422	/*
	423	* Fill out the arp protocol part.
	424	*
	425	* we only support ethernet device type,
	426	* which (according to RFC 1390) should always equal 1 (Ethernet).
	427	*/
	428
	429	arp->ar_hrd = htons(np->dev->type);
	430	arp->ar_pro = htons(ETH_P_IP);
	431	arp->ar_hln = np->dev->addr_len;
	432	arp->ar_pln = 4;
	433	arp->ar_op = htons(type);
	434
	435	arp_ptr=(unsigned char *)(arp + 1);
436	memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
437	arp_ptr += np->dev->addr_len;
438	memcpy(arp_ptr, &tip, 4);
439	arp_ptr += 4;
440	memcpy(arp_ptr, np->remote_mac, np->dev->addr_len);
441	arp_ptr += np->dev->addr_len;
442	memcpy(arp_ptr, &sip, 4);
443
444	netpoll_send_skb(np, send_skb);
445	}
446
447	int __netpoll_rx(struct sk_buff *skb)
448	{
449	int proto, len, ulen;
450	struct iphdr *iph;
451	struct udphdr *uh;
fbeec2e1	452	struct netpoll *np = skb->dev->npinfo->rx_np;
1da177e4	453
fbeec2e1	454	if (!np)
1da177e4 LT	455	goto out;
	456	if (skb->dev->type != ARPHRD_ETHER)
	457	goto out;
	458
	459	/* check if netpoll clients need ARP */
	460	if (skb->protocol == __constant_htons(ETH_P_ARP) &&
	461	atomic_read(&trapped)) {
	462	arp_reply(skb);
	463	return 1;
	464	}
	465
	466	proto = ntohs(eth_hdr(skb)->h_proto);
	467	if (proto != ETH_P_IP)
	468	goto out;
	469	if (skb->pkt_type == PACKET_OTHERHOST)
	470	goto out;
	471	if (skb_shared(skb))
	472	goto out;
	473
	474	iph = (struct iphdr *)skb->data;
	475	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
	476	goto out;
	477	if (iph->ihl < 5 \|\| iph->version != 4)
	478	goto out;
	479	if (!pskb_may_pull(skb, iph->ihl*4))
	480	goto out;
	481	if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
	482	goto out;
	483
	484	len = ntohs(iph->tot_len);
	485	if (skb->len < len \|\| len < iph->ihl*4)
	486	goto out;
	487
	488	if (iph->protocol != IPPROTO_UDP)
	489	goto out;
	490
	491	len -= iph->ihl*4;
	492	uh = (struct udphdr )(((char )iph) + iph->ihl*4);
	493	ulen = ntohs(uh->len);
	494
	495	if (ulen != len)
	496	goto out;
fb286bb2	497	if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
1da177e4 LT	498	goto out;
	499	if (np->local_ip && np->local_ip != ntohl(iph->daddr))
	500	goto out;
	501	if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
	502	goto out;
	503	if (np->local_port && np->local_port != ntohs(uh->dest))
	504	goto out;
	505
	506	np->rx_hook(np, ntohs(uh->source),
	507	(char *)(uh+1),
	508	ulen - sizeof(struct udphdr));
	509
	510	kfree_skb(skb);
	511	return 1;
	512
	513	out:
	514	if (atomic_read(&trapped)) {
	515	kfree_skb(skb);
	516	return 1;
	517	}
	518
	519	return 0;
	520	}
	521
	522	int netpoll_parse_options(struct netpoll np, char opt)
	523	{
	524	char cur=opt, delim;
	525
	526	if(*cur != '@') {
	527	if ((delim = strchr(cur, '@')) == NULL)
	528	goto parse_failed;
	529	*delim=0;
	530	np->local_port=simple_strtol(cur, NULL, 10);
	531	cur=delim;
	532	}
	533	cur++;
	534	printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port);
	535
	536	if(*cur != '/') {
	537	if ((delim = strchr(cur, '/')) == NULL)
	538	goto parse_failed;
	539	*delim=0;
	540	np->local_ip=ntohl(in_aton(cur));
	541	cur=delim;
	542
	543	printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
	544	np->name, HIPQUAD(np->local_ip));
	545	}
	546	cur++;
	547
	548	if ( *cur != ',') {
	549	/* parse out dev name */
	550	if ((delim = strchr(cur, ',')) == NULL)
	551	goto parse_failed;
	552	*delim=0;
	553	strlcpy(np->dev_name, cur, sizeof(np->dev_name));
	554	cur=delim;
	555	}
	556	cur++;
	557
	558	printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name);
	559
	560	if ( *cur != '@' ) {
	561	/* dst port */
562	if ((delim = strchr(cur, '@')) == NULL)
563	goto parse_failed;
564	*delim=0;
565	np->remote_port=simple_strtol(cur, NULL, 10);
566	cur=delim;
567	}
568	cur++;
569	printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port);
570
571	/* dst ip */
572	if ((delim = strchr(cur, '/')) == NULL)
573	goto parse_failed;
574	*delim=0;
575	np->remote_ip=ntohl(in_aton(cur));
576	cur=delim+1;
577
578	printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
579	np->name, HIPQUAD(np->remote_ip));
580
581	if( *cur != 0 )
582	{
583	/* MAC address */
584	if ((delim = strchr(cur, ':')) == NULL)
585	goto parse_failed;
586	*delim=0;
587	np->remote_mac[0]=simple_strtol(cur, NULL, 16);
588	cur=delim+1;
589	if ((delim = strchr(cur, ':')) == NULL)
590	goto parse_failed;
591	*delim=0;
592	np->remote_mac[1]=simple_strtol(cur, NULL, 16);
593	cur=delim+1;
594	if ((delim = strchr(cur, ':')) == NULL)
595	goto parse_failed;
596	*delim=0;
597	np->remote_mac[2]=simple_strtol(cur, NULL, 16);
598	cur=delim+1;
599	if ((delim = strchr(cur, ':')) == NULL)
600	goto parse_failed;
601	*delim=0;
602	np->remote_mac[3]=simple_strtol(cur, NULL, 16);
603	cur=delim+1;
604	if ((delim = strchr(cur, ':')) == NULL)
605	goto parse_failed;
606	*delim=0;
607	np->remote_mac[4]=simple_strtol(cur, NULL, 16);
608	cur=delim+1;
609	np->remote_mac[5]=simple_strtol(cur, NULL, 16);
610	}
611
612	printk(KERN_INFO "%s: remote ethernet address "
613	"%02x:%02x:%02x:%02x:%02x:%02x\n",
614	np->name,
615	np->remote_mac[0],
616	np->remote_mac[1],
617	np->remote_mac[2],
618	np->remote_mac[3],
619	np->remote_mac[4],
620	np->remote_mac[5]);
621
622	return 0;
623
624	parse_failed:
625	printk(KERN_INFO "%s: couldn't parse config at %s!\n",
626	np->name, cur);
627	return -1;
628	}
629
630	int netpoll_setup(struct netpoll *np)
631	{
632	struct net_device *ndev = NULL;
633	struct in_device *in_dev;
115c1d6e	634	struct netpoll_info *npinfo;
fbeec2e1	635	unsigned long flags;
1da177e4 LT	636
	637	if (np->dev_name)
	638	ndev = dev_get_by_name(np->dev_name);
	639	if (!ndev) {
	640	printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
	641	np->name, np->dev_name);
	642	return -1;
	643	}
	644
	645	np->dev = ndev;
115c1d6e JM	646	if (!ndev->npinfo) {
	647	npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
	648	if (!npinfo)
	649	goto release;
	650
11513128	651	npinfo->rx_flags = 0;
fbeec2e1	652	npinfo->rx_np = NULL;
a9f6a0dd	653	spin_lock_init(&npinfo->poll_lock);
115c1d6e	654	npinfo->poll_owner = -1;
0db1d6fc	655	npinfo->tries = MAX_RETRIES;
a9f6a0dd	656	spin_lock_init(&npinfo->rx_lock);
115c1d6e JM	657	} else
115c1d6e JM	658	npinfo = ndev->npinfo;
1da177e4 LT	659
	660	if (!ndev->poll_controller) {
	661	printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
	662	np->name, np->dev_name);
	663	goto release;
	664	}
	665
	666	if (!netif_running(ndev)) {
	667	unsigned long atmost, atleast;
	668
	669	printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
	670	np->name, np->dev_name);
	671
	672	rtnl_shlock();
	673	if (dev_change_flags(ndev, ndev->flags \| IFF_UP) < 0) {
	674	printk(KERN_ERR "%s: failed to open %s\n",
	675	np->name, np->dev_name);
	676	rtnl_shunlock();
	677	goto release;
	678	}
	679	rtnl_shunlock();
	680
	681	atleast = jiffies + HZ/10;
	682	atmost = jiffies + 4*HZ;
	683	while (!netif_carrier_ok(ndev)) {
	684	if (time_after(jiffies, atmost)) {
	685	printk(KERN_NOTICE
	686	"%s: timeout waiting for carrier\n",
	687	np->name);
	688	break;
	689	}
	690	cond_resched();
	691	}
	692
	693	/* If carrier appears to come up instantly, we don't
	694	* trust it and pause so that we don't pump all our
	695	* queued console messages into the bitbucket.
	696	*/
	697
	698	if (time_before(jiffies, atleast)) {
	699	printk(KERN_NOTICE "%s: carrier detect appears"
	700	" untrustworthy, waiting 4 seconds\n",
	701	np->name);
	702	msleep(4000);
	703	}
	704	}
	705
3860288e	706	if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
1da177e4 LT	707	memcpy(np->local_mac, ndev->dev_addr, 6);
	708
	709	if (!np->local_ip) {
	710	rcu_read_lock();
e5ed6399	711	in_dev = __in_dev_get_rcu(ndev);
1da177e4 LT	712
	713	if (!in_dev \|\| !in_dev->ifa_list) {
	714	rcu_read_unlock();
	715	printk(KERN_ERR "%s: no IP address for %s, aborting\n",
	716	np->name, np->dev_name);
	717	goto release;
	718	}
	719
	720	np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
	721	rcu_read_unlock();
	722	printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
	723	np->name, HIPQUAD(np->local_ip));
	724	}
	725
fbeec2e1 JM	726	if (np->rx_hook) {
	727	spin_lock_irqsave(&npinfo->rx_lock, flags);
	728	npinfo->rx_flags \|= NETPOLL_RX_ENABLED;
	729	npinfo->rx_np = np;
	730	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
	731	}
26520765 IM	732
	733	/* fill up the skb queue */
	734	refill_skbs();
	735
fbeec2e1	736	/* last thing to do is link it to the net device structure */
115c1d6e	737	ndev->npinfo = npinfo;
1da177e4	738
53fb95d3 MM	739	/* avoid racing with NAPI reading npinfo */
	740	synchronize_rcu();
	741
1da177e4 LT	742	return 0;
	743
	744	release:
115c1d6e JM	745	if (!ndev->npinfo)
115c1d6e JM	746	kfree(npinfo);
1da177e4 LT	747	np->dev = NULL;
	748	dev_put(ndev);
	749	return -1;
	750	}
	751
	752	void netpoll_cleanup(struct netpoll *np)
	753	{
fbeec2e1 JM	754	struct netpoll_info *npinfo;
	755	unsigned long flags;
	756
115c1d6e	757	if (np->dev) {
fbeec2e1 JM	758	npinfo = np->dev->npinfo;
	759	if (npinfo && npinfo->rx_np == np) {
	760	spin_lock_irqsave(&npinfo->rx_lock, flags);
	761	npinfo->rx_np = NULL;
	762	npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
	763	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
	764	}
115c1d6e JM	765	dev_put(np->dev);
115c1d6e JM	766	}
fbeec2e1	767
1da177e4 LT	768	np->dev = NULL;
	769	}
	770
	771	int netpoll_trap(void)
	772	{
	773	return atomic_read(&trapped);
	774	}
	775
	776	void netpoll_set_trap(int trap)
	777	{
	778	if (trap)
	779	atomic_inc(&trapped);
	780	else
	781	atomic_dec(&trapped);
	782	}
	783
	784	EXPORT_SYMBOL(netpoll_set_trap);
	785	EXPORT_SYMBOL(netpoll_trap);
	786	EXPORT_SYMBOL(netpoll_parse_options);
	787	EXPORT_SYMBOL(netpoll_setup);
	788	EXPORT_SYMBOL(netpoll_cleanup);
	789	EXPORT_SYMBOL(netpoll_send_udp);
	790	EXPORT_SYMBOL(netpoll_poll);
	791	EXPORT_SYMBOL(netpoll_queue);