From c9db62c69f26684eb5b00c620d0e182f3e336412 Mon Sep 17 00:00:00 2001
From: Kozlov Dmitry <dima@server>
Date: Sat, 21 Aug 2010 12:53:18 +0400
Subject: * use rcu + spin_lock in gre module for 2.6 kernel * use rcu +
 spin_lock instead of rcu + semaphone in pptp module * fixed incorrect
 rcu_synchronize() place * use static bitmap (DECLARE_BITMAP) instead of
 dynamically allocated * use vmalloc for callid_sock memory allocation instead
 of BITS_PER_LONG + __get_free_pages * avoid copying writable clones (thanks
 to theMIROn)

---
 kernel/driver/gre.c | 107 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 85 insertions(+), 22 deletions(-)

(limited to 'kernel/driver/gre.c')

diff --git a/kernel/driver/gre.c b/kernel/driver/gre.c
index cda0576b..485da85d 100644
--- a/kernel/driver/gre.c
+++ b/kernel/driver/gre.c
@@ -10,50 +10,83 @@
 
 #include "gre.h"
 
-
 struct gre_protocol *gre_proto[GREPROTO_MAX] ____cacheline_aligned_in_smp;
-static DEFINE_RWLOCK(gre_proto_lock);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+static rwlock_t chan_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 -1;
+		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 = -1;
+		ret = -EAGAIN;
 	} else {
-		gre_proto[version]=proto;
+#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)
 {
-	int ret;
-
 	if (version >= GREPROTO_MAX)
-		return -1;
+		goto out_err;
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 	write_lock_bh(&gre_proto_lock);
-	if (gre_proto[version] == proto) {
+#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;
-		ret = 0;
-	} else {
-		ret = -1;
-	}
+#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;
 
-	return ret;
+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;
@@ -62,17 +95,32 @@ static int gre_rcv(struct sk_buff *skb)
 	if (ver >= GREPROTO_MAX)
 		goto drop_nolock;
 	
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 	read_lock(&gre_proto_lock);
-	if (!gre_proto[ver] || !gre_proto[ver]->handler)
+	proto = gre_proto[ver];
+#else
+	rcu_read_lock();
+	proto = rcu_dereference(gre_proto[ver]);
+#endif
+	if (!proto || !proto->handler)
 		goto drop;
 
-	ret = gre_proto[ver]->handler(skb);
+	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;
@@ -80,27 +128,40 @@ drop_nolock:
 static void gre_err(struct sk_buff *skb, u32 info)
 {
 	u8 ver;
-
-	printk("err\n");
+	struct gre_protocol *proto;
 
 	if (!pskb_may_pull(skb, 12))
 		goto drop_nolock;
 
-	ver=skb->data[1];
+	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);
-	if (!gre_proto[ver] || !gre_proto[ver]->err_handler)
+	proto = gre_proto[ver];
+#else
+	rcu_read_lock();
+	proto = rcu_dereference(gre_proto[ver]);
+#endif
+	if (!proto || !proto->err_handler)
 		goto drop;
 
-	gre_proto[ver]->err_handler(skb,info);
+	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);
 }
@@ -109,7 +170,9 @@ drop_nolock:
 static struct net_protocol net_gre_protocol = {
 	.handler	= gre_rcv,
 	.err_handler	=	gre_err,
-//	.netns_ok=1,
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,24)
+	.netns_ok=1,
+#endif
 };
 
 static int __init gre_init(void)
-- 
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