merged branch accel-pptpd

1 files changed, 220 insertions, 0 deletions

diff --git a/driver/gre.c b/driver/gre.c
new file mode 100644
index 0000000..77886d5
--- /dev/null
+++ b/driver/gre.c
@@ -0,0 +1,220 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <linux/spinlock.h>
+#include <net/protocol.h>
+
+#include "gre.h"
+
+struct gre_protocol *gre_proto[GREPROTO_MAX] ____cacheline_aligned_in_smp;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+static rwlock_t gre_proto_lock=RW_LOCK_UNLOCKED;
+#else
+static DEFINE_SPINLOCK(gre_proto_lock);
+#endif
+
+int gre_add_protocol(struct gre_protocol *proto, u8 version)
+{
+	int ret;
+
+	if (version >= GREPROTO_MAX)
+		return -EINVAL;
+	
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	write_lock_bh(&gre_proto_lock);
+#else
+	spin_lock(&gre_proto_lock);
+#endif
+	if (gre_proto[version]) {
+		ret = -EAGAIN;
+	} else {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+		gre_proto[version] = proto;
+#else
+		rcu_assign_pointer(gre_proto[version], proto);
+#endif
+		ret = 0;
+	}
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	write_unlock_bh(&gre_proto_lock);
+#else
+	spin_unlock(&gre_proto_lock);
+#endif
+
+	return ret;
+}
+
+int gre_del_protocol(struct gre_protocol *proto, u8 version)
+{
+	if (version >= GREPROTO_MAX)
+		goto out_err;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	write_lock_bh(&gre_proto_lock);
+#else
+	spin_lock(&gre_proto_lock);
+#endif
+	if (gre_proto[version] == proto)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+		gre_proto[version] = NULL;
+#else
+		rcu_assign_pointer(gre_proto[version], NULL);
+#endif
+	else
+		goto out_err_unlock;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	write_unlock_bh(&gre_proto_lock);
+#else
+	spin_unlock(&gre_proto_lock);
+	synchronize_rcu();
+#endif
+	return 0;
+
+out_err_unlock:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	write_unlock_bh(&gre_proto_lock);
+#else
+	spin_unlock(&gre_proto_lock);
+#endif
+out_err:
+	return -EINVAL;
+}
+
+static int gre_rcv(struct sk_buff *skb)
+{
+	u8 ver;
+	int ret;
+	struct gre_protocol *proto;
+
+	if (!pskb_may_pull(skb, 12))
+		goto drop_nolock;
+
+	ver = skb->data[1]&0x7f;
+	if (ver >= GREPROTO_MAX)
+		goto drop_nolock;
+	
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_lock(&gre_proto_lock);
+	proto = gre_proto[ver];
+#else
+	rcu_read_lock();
+	proto = rcu_dereference(gre_proto[ver]);
+#endif
+	if (!proto || !proto->handler)
+		goto drop;
+
+	ret = proto->handler(skb);
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_unlock(&gre_proto_lock);
+#else
+	rcu_read_unlock();
+#endif
+
+	return ret;
+
+drop:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_unlock(&gre_proto_lock);
+#else
+	rcu_read_unlock();
+#endif
+drop_nolock:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static void gre_err(struct sk_buff *skb, u32 info)
+{
+	u8 ver;
+	struct gre_protocol *proto;
+
+	if (!pskb_may_pull(skb, 12))
+		goto drop_nolock;
+
+	ver=skb->data[1]&0x7f;
+	if (ver>=GREPROTO_MAX)
+		goto drop_nolock;
+		
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_lock(&gre_proto_lock);
+	proto = gre_proto[ver];
+#else
+	rcu_read_lock();
+	proto = rcu_dereference(gre_proto[ver]);
+#endif
+	if (!proto || !proto->err_handler)
+		goto drop;
+
+	proto->err_handler(skb, info);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_unlock(&gre_proto_lock);
+#else
+	rcu_read_unlock();
+#endif
+
+	return;
+
+drop:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	read_unlock(&gre_proto_lock);
+#else
+	rcu_read_unlock();
+#endif
+drop_nolock:
+	kfree_skb(skb);
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+static struct inet_protocol net_gre_protocol = {
+	.handler	= gre_rcv,
+	.err_handler	= gre_err,
+	.protocol	= IPPROTO_GRE,
+	.name		= "GRE",
+};
+#else
+static struct net_protocol net_gre_protocol = {
+	.handler	= gre_rcv,
+	.err_handler	= gre_err,
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,24)
+	.netns_ok=1,
+#endif
+};
+#endif
+
+static int __init gre_init(void)
+{
+	printk(KERN_INFO "GRE over IPv4 demultiplexor driver");
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	inet_add_protocol(&net_gre_protocol);
+#else
+	if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
+		printk(KERN_INFO "gre: can't add protocol\n");
+		return -EAGAIN;
+	}
+#endif
+	return 0;
+}
+
+static void __exit gre_exit(void)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	inet_del_protocol(&net_gre_protocol);
+#else
+	inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
+#endif
+}
+
+module_init(gre_init);
+module_exit(gre_exit);
+
+MODULE_DESCRIPTION("GRE over IPv4 demultiplexor driver");
+MODULE_AUTHOR("Kozlov D. (xeb@mail.ru)");
+MODULE_LICENSE("GPL");
+EXPORT_SYMBOL_GPL(gre_add_protocol);
+EXPORT_SYMBOL_GPL(gre_del_protocol);