1 files changed, 735 insertions, 0 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
new file mode 100644
index 000000000000..a119696d5521
--- /dev/null
+++ b/net/core/netpoll.c
@@ -0,0 +1,735 @@
+/*
+ * 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/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)
+
+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)
+{
+	if (uh->check == 0)
+		return 0;
+
+	if (skb->ip_summed == CHECKSUM_HW)
+		return csum_tcpudp_magic(
+			saddr, daddr, ulen, IPPROTO_UDP, skb->csum);
+
+	skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
+
+	return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
+}
+
+/*
+ * 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)
+{
+	int budget = 16;
+
+	if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
+	    np->poll_owner != smp_processor_id() &&
+	    spin_trylock(&np->poll_lock)) {
+		np->rx_flags |= NETPOLL_RX_DROP;
+		atomic_inc(&trapped);
+
+		np->dev->poll(np->dev, &budget);
+
+		atomic_dec(&trapped);
+		np->rx_flags &= ~NETPOLL_RX_DROP;
+		spin_unlock(&np->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;
+
+repeat:
+	if(!np || !np->dev || !netif_running(np->dev)) {
+		__kfree_skb(skb);
+		return;
+	}
+
+	/* avoid recursion */
+	if(np->poll_owner == smp_processor_id() ||
+	   np->dev->xmit_lock_owner == smp_processor_id()) {
+		if (np->drop)
+			np->drop(skb);
+		else
+			__kfree_skb(skb);
+		return;
+	}
+
+	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);
+		goto repeat;
+	}
+
+	status = np->dev->hard_start_xmit(skb, np->dev);
+	np->dev->xmit_lock_owner = -1;
+	spin_unlock(&np->dev->xmit_lock);
+
+	/* transmit busy */
+	if(status) {
+		netpoll_poll(np);
+		goto repeat;
+	}
+}
+
+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 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 = skb->dev->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->np;
+
+	if (!np->rx_hook)
+		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) < 0)
+		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;
+
+	np->poll_lock = SPIN_LOCK_UNLOCKED;
+	np->poll_owner = -1;
+
+	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;
+	ndev->np = np;
+
+	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 (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr)
+		memcpy(np->local_mac, ndev->dev_addr, 6);
+
+	if (!np->local_ip) {
+		rcu_read_lock();
+		in_dev = __in_dev_get(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)
+		np->rx_flags = NETPOLL_RX_ENABLED;
+
+	return 0;
+
+ release:
+	ndev->np = NULL;
+	np->dev = NULL;
+	dev_put(ndev);
+	return -1;
+}
+
+void netpoll_cleanup(struct netpoll *np)
+{
+	if (np->dev)
+		np->dev->np = NULL;
+	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);