patch-2.1.8 linux/net/ipv6/sit.c

• Lines: 579
• Date: Sun Nov 3 11:04:46 1996
• Orig file: v2.1.7/linux/net/ipv6/sit.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.7/linux/net/ipv6/sit.c linux/net/ipv6/sit.c
@@ -0,0 +1,578 @@
+/*
+ *	IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>	
+ *
+ *
+ *	This program 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.
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/sched.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/icmp.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/ndisc.h>
+#include <net/ipv6_route.h>
+#include <net/addrconf.h>
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/sit.h>
+
+
+static int sit_init_dev(struct device *dev);
+
+static struct device sit_device = {
+	"sit0",
+	0, 0, 0, 0,
+	0x0, 0,
+	0, 0, 0, NULL, sit_init_dev
+};
+
+static unsigned long		sit_gc_last_run;
+static void			sit_mtu_cache_gc(void);
+
+static int			sit_xmit(struct sk_buff *skb, 
+					 struct device *dev);
+static int			sit_rcv(struct sk_buff *skb, 
+					struct device *dev, 
+					struct options *opt,
+					__u32 daddr, unsigned short len,
+					__u32 saddr, int redo, 
+					struct inet_protocol * protocol);
+
+static int			sit_open(struct device *dev);
+static int			sit_close(struct device *dev);
+
+static struct enet_statistics *	sit_get_stats(struct device *dev);
+
+static void			sit_err(int type, int code, 
+					unsigned char *buff, __u32 info,
+					__u32 daddr, __u32 saddr,
+					struct inet_protocol *protocol);
+
+static struct inet_protocol sit_protocol = {
+	sit_rcv,
+	sit_err,
+	0,
+	IPPROTO_IPV6,
+	0,
+	NULL,
+	"IPv6"
+};
+
+#define SIT_NUM_BUCKETS	16
+
+struct sit_mtu_info *sit_mtu_cache[SIT_NUM_BUCKETS];
+
+static int		vif_num = 0;
+static struct sit_vif	*vif_list = NULL;
+
+static __inline__ __u32 sit_addr_hash(__u32 addr)
+{
+        
+        __u32 hash_val;
+        
+        hash_val = addr;
+
+        hash_val ^= hash_val >> 16;
+	hash_val ^= hash_val >> 8;
+        
+        return (hash_val & (SIT_NUM_BUCKETS - 1));
+}
+
+static void sit_cache_insert(__u32 addr, int mtu)
+{
+	struct sit_mtu_info *minfo;
+	int hash;
+	
+	minfo = kmalloc(sizeof(struct sit_mtu_info), GFP_ATOMIC);
+	
+	if (minfo == NULL)
+		return;
+
+	minfo->addr = addr;
+	minfo->tstamp = jiffies;
+	minfo->mtu = mtu;
+
+	hash = sit_addr_hash(addr);
+
+	minfo->next = sit_mtu_cache[hash];
+	sit_mtu_cache[hash] = minfo;
+}
+
+static struct sit_mtu_info * sit_mtu_lookup(__u32 addr)
+{
+	struct sit_mtu_info *iter;
+	int hash;
+
+	hash = sit_addr_hash(addr);
+
+	for(iter = sit_mtu_cache[hash]; iter; iter=iter->next)
+	{
+		if (iter->addr == addr)
+		{
+			iter->tstamp = jiffies;
+			break;
+		}
+	}
+
+	/*
+	 *	run garbage collector
+	 */
+
+	if (jiffies - sit_gc_last_run > SIT_GC_FREQUENCY)
+	{
+		sit_mtu_cache_gc();
+		sit_gc_last_run = jiffies;
+	}
+
+	return iter;
+}
+
+static void sit_mtu_cache_gc(void)
+{
+	struct sit_mtu_info *iter, *back;
+	unsigned long now = jiffies;
+	int i;
+
+	for (i=0; i < SIT_NUM_BUCKETS; i++)
+	{
+		back = NULL;
+		for (iter = sit_mtu_cache[i]; iter;)
+		{
+			if (now - iter->tstamp > SIT_GC_TIMEOUT)
+			{
+				struct sit_mtu_info *old;
+
+				old = iter;
+				iter = iter->next;
+
+				if (back)
+				{
+					back->next = iter;
+				}
+				else
+				{
+					sit_mtu_cache[i] = iter;
+				}
+
+				kfree(old);
+				continue;
+			}
+			back = iter;
+			iter = iter->next;
+		}
+	}
+}
+
+static int sit_init_dev(struct device *dev)
+{
+	int i;
+
+	dev->open	= sit_open;
+	dev->stop	= sit_close;
+
+	dev->hard_start_xmit	= sit_xmit;
+	dev->get_stats		= sit_get_stats;
+
+	dev->priv = kmalloc(sizeof(struct enet_statistics), GFP_KERNEL);
+
+	if (dev->priv == NULL)
+		return -ENOMEM;
+
+	memset(dev->priv, 0, sizeof(struct enet_statistics));
+
+
+	for (i = 0; i < DEV_NUMBUFFS; i++)
+		skb_queue_head_init(&dev->buffs[i]);
+
+	dev->hard_header	= NULL;
+	dev->rebuild_header 	= NULL;
+	dev->set_mac_address 	= NULL;
+	dev->header_cache_bind 	= NULL;
+	dev->header_cache_update= NULL;
+
+	dev->type		= ARPHRD_SIT;
+
+	dev->hard_header_len 	= MAX_HEADER;
+	dev->mtu		= 1500 - sizeof(struct iphdr);
+	dev->addr_len		= 0;
+	dev->tx_queue_len	= 2;
+
+	memset(dev->broadcast, 0, MAX_ADDR_LEN);
+	memset(dev->dev_addr,  0, MAX_ADDR_LEN);
+
+	dev->flags		= IFF_NOARP;	
+
+	dev->family		= AF_INET6;
+	dev->pa_addr		= 0;
+	dev->pa_brdaddr 	= 0;
+	dev->pa_dstaddr		= 0;
+	dev->pa_mask		= 0;
+	dev->pa_alen		= 4;
+
+	return 0;
+}
+
+static int sit_init_vif(struct device *dev)
+{
+	int i;
+
+	dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST;
+	dev->priv = kmalloc(sizeof(struct enet_statistics), GFP_KERNEL);
+
+	if (dev->priv == NULL)
+		return -ENOMEM;
+
+	memset(dev->priv, 0, sizeof(struct enet_statistics));
+
+	for (i = 0; i < DEV_NUMBUFFS; i++)
+		skb_queue_head_init(&dev->buffs[i]);
+		
+	return 0;
+}
+
+static int sit_open(struct device *dev)
+{
+	return 0;
+}
+
+static int sit_close(struct device *dev)
+{
+	return 0;
+}
+
+
+int sit_init(void)
+{
+	int i;
+
+	/* register device */
+
+	if (register_netdev(&sit_device) != 0)
+	{
+		return -EIO;
+	}
+
+	inet_add_protocol(&sit_protocol);
+
+	for (i=0; i < SIT_NUM_BUCKETS; i++)
+		sit_mtu_cache[i] = NULL;
+
+	sit_gc_last_run = jiffies;
+
+	return 0;
+}
+
+struct device *sit_add_tunnel(__u32 dstaddr)
+{
+	struct sit_vif *vif;
+	struct device *dev;
+	
+	vif = kmalloc(sizeof(struct sit_vif), GFP_KERNEL);
+	if (vif == NULL)
+		return NULL;
+	
+	/*
+	 *	Create PtoP configured tunnel
+	 */
+	
+	dev = kmalloc(sizeof(struct device), GFP_KERNEL);
+	if (dev == NULL)
+		return NULL;
+
+	memcpy(dev, &sit_device, sizeof(struct device));
+	dev->init = sit_init_vif;
+	dev->pa_dstaddr = dstaddr;
+
+	dev->name = vif->name;
+	sprintf(vif->name, "sit%d", ++vif_num);
+
+	register_netdev(dev);
+
+	vif->dev = dev;
+	vif->next = vif_list;
+	vif_list = vif;
+
+	return dev;
+}
+
+void sit_cleanup(void)
+{
+	struct sit_vif *vif;
+	
+	for (vif = vif_list; vif;)
+	{
+		struct device *dev = vif->dev;
+		struct sit_vif *cur;
+
+		unregister_netdev(dev);
+		kfree(dev->priv);
+		kfree(dev);
+		
+		cur = vif;
+		vif = vif->next;
+	}
+
+	vif_list = NULL;
+
+	unregister_netdev(&sit_device);
+	inet_del_protocol(&sit_protocol);
+	
+}
+
+
+
+/*
+ *	receive IPv4 ICMP messages
+ */
+
+static void sit_err(int type, int code, unsigned char *buff, __u32 info,
+		    __u32 daddr, __u32 saddr, struct inet_protocol *protocol)
+		    
+{
+	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+	{
+		struct sit_mtu_info *minfo;
+
+		info -= sizeof(struct iphdr);
+
+		minfo = sit_mtu_lookup(daddr);
+
+		printk(KERN_DEBUG "sit: %08lx pmtu = %ul\n", ntohl(saddr),
+		       info);
+		if (minfo == NULL)
+		{
+			minfo = kmalloc(sizeof(struct sit_mtu_info),
+					GFP_ATOMIC);
+
+			if (minfo == NULL)
+				return;
+
+			start_bh_atomic();
+			sit_cache_insert(daddr, info);
+			end_bh_atomic();
+		}
+		else
+		{
+			minfo->mtu = info;
+		}
+	}
+}
+
+static int sit_rcv(struct sk_buff *skb, struct device *idev, 
+		   struct options *opt,
+		   __u32 daddr, unsigned short len,
+		   __u32 saddr, int redo, struct inet_protocol * protocol)
+{
+	struct enet_statistics *stats;
+	struct device *dev = NULL;
+	struct sit_vif *vif;	
+       
+	skb->h.raw = skb_pull(skb, skb->h.raw - skb->data);
+	skb->protocol = __constant_htons(ETH_P_IPV6);
+
+	for (vif = vif_list; vif; vif = vif->next)
+	{
+		if (saddr == vif->dev->pa_dstaddr)
+		{
+			dev = vif->dev;
+			break;
+		}
+	}
+
+	if (dev == NULL)
+	{
+		dev = &sit_device;
+	}
+
+	skb->dev = dev;
+	skb->ip_summed = CHECKSUM_NONE;
+
+	stats = (struct enet_statistics *)dev->priv;
+	stats->rx_packets++;
+
+	ipv6_rcv(skb, dev, NULL);
+	return 0;
+}
+
+static int sit_xmit(struct sk_buff *skb, struct device *dev)
+{
+	struct enet_statistics *stats;
+	struct sit_mtu_info *minfo;
+	struct in6_addr *addr6;	
+	unsigned long flags;
+	struct rtable *rt;
+	struct iphdr *iph;
+	__u32 saddr;
+	__u32 daddr;
+	__u32 raddr;
+	int addr_type;
+	int mtu;
+	int len;
+
+	/* 
+	 *	Make sure we are not busy (check lock variable) 
+	 */
+
+	stats = (struct enet_statistics *)dev->priv;
+	save_flags(flags);
+	cli();
+	if (dev->tbusy != 0) 
+	{
+		restore_flags(flags);
+		printk(KERN_DEBUG "sit_xmit: busy\n");
+		return(1);
+	}
+	dev->tbusy = 1;
+	restore_flags(flags);
+
+	daddr = dev->pa_dstaddr;
+	if (daddr == 0)
+	{
+		addr6 = &skb->ipv6_hdr->daddr;
+		addr_type = ipv6_addr_type(addr6);
+
+		if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
+		{
+			printk(KERN_DEBUG "sit_xmit: non v4 address\n");
+			goto on_error;
+		}
+	}
+
+	len = skb->tail - (skb->data + sizeof(struct ipv6hdr));
+
+	if (skb->sk)
+	{
+		atomic_sub(skb->truesize, &skb->sk->wmem_alloc);
+	}
+
+	skb->sk = NULL;
+		
+	iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr));
+	
+	skb->protocol = htons(ETH_P_IP);
+
+	/* get route */
+
+	rt = ip_rt_route(daddr, skb->localroute);
+	
+	if (rt == NULL)
+	{
+		printk(KERN_DEBUG "sit: no route to host\n");
+		goto on_error;
+	}
+
+	minfo = sit_mtu_lookup(daddr);
+
+	if (minfo)
+		mtu = minfo->mtu;
+	else
+		mtu = rt->rt_dev->mtu;
+
+	if (mtu > 576 && len > mtu)
+	{
+		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
+		goto on_error;
+	}
+
+	saddr = rt->rt_src;
+	skb->dev = rt->rt_dev;
+	raddr = rt->rt_gateway;	
+
+	if (raddr == 0)
+		raddr = daddr;
+
+	/* now for the device header */
+
+	skb->arp = 1;
+		
+	if (skb->dev->hard_header_len) 
+	{
+		int mac;
+
+		if (skb->data - skb->head < skb->dev->hard_header_len)
+		{
+			printk(KERN_DEBUG "sit: space at head < dev header\n");
+			goto on_error;
+		}
+
+		if (skb->dev->hard_header)
+		{
+			mac = skb->dev->hard_header(skb, skb->dev, ETH_P_IP, 
+					       NULL, NULL, len);
+
+			if (mac < 0)
+				skb->arp = 0;
+
+			skb->raddr = raddr;		
+		}
+		
+	}
+
+	ip_rt_put(rt);
+
+
+	iph->version  = 4;
+	iph->ihl      = 5;
+	iph->tos      = 0;				/* tos set to 0... */
+
+	if (mtu > 576)
+	{
+		iph->frag_off = htons(IP_DF);
+	}
+	else
+		iph->frag_off = 0;
+
+	iph->ttl      = 64;
+	iph->saddr    = saddr;
+	iph->daddr    = daddr;
+	iph->protocol = IPPROTO_IPV6;
+	skb->ip_hdr   = iph;
+
+	ip_send_check(iph);
+
+	ip_queue_xmit(NULL, skb->dev, skb, 1);
+
+	stats->tx_packets++;
+	dev->tbusy=0;
+
+	return 0;
+
+  on_error:
+	kfree_skb(skb, FREE_WRITE);
+	dev->tbusy=0;
+	stats->tx_errors++;
+	return 0;	
+}
+
+static struct enet_statistics *sit_get_stats(struct device *dev)
+{
+	return((struct enet_statistics*) dev->priv);
+}
+
+
+/*
+ * Local variables:
+ *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strength-reduce -pipe -m486 -DCPU=486 -DMODULE -DMODVERSIONS -include /usr/src/linux/include/linux/modversions.h  -c -o sit.o sit.c"
+ * c-file-style: "Linux"
+ * End:
+ */