6f0bcf1525
(struct ip6_tnl)->next is rcu protected : (struct ip_tunnel)->next is rcu protected : (struct xfrm6_tunnel)->next is rcu protected : add __rcu annotation and proper rcu primitives. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
153 lines
3.0 KiB
C
153 lines
3.0 KiB
C
/*
|
|
* GRE over IPv4 demultiplexer driver
|
|
*
|
|
* Authors: Dmitry Kozlov (xeb@mail.ru)
|
|
*
|
|
* 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/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kmod.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 <net/gre.h>
|
|
|
|
|
|
static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
|
|
static DEFINE_SPINLOCK(gre_proto_lock);
|
|
|
|
int gre_add_protocol(const struct gre_protocol *proto, u8 version)
|
|
{
|
|
if (version >= GREPROTO_MAX)
|
|
goto err_out;
|
|
|
|
spin_lock(&gre_proto_lock);
|
|
if (gre_proto[version])
|
|
goto err_out_unlock;
|
|
|
|
rcu_assign_pointer(gre_proto[version], proto);
|
|
spin_unlock(&gre_proto_lock);
|
|
return 0;
|
|
|
|
err_out_unlock:
|
|
spin_unlock(&gre_proto_lock);
|
|
err_out:
|
|
return -1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gre_add_protocol);
|
|
|
|
int gre_del_protocol(const struct gre_protocol *proto, u8 version)
|
|
{
|
|
if (version >= GREPROTO_MAX)
|
|
goto err_out;
|
|
|
|
spin_lock(&gre_proto_lock);
|
|
if (rcu_dereference_protected(gre_proto[version],
|
|
lockdep_is_held(&gre_proto_lock)) != proto)
|
|
goto err_out_unlock;
|
|
rcu_assign_pointer(gre_proto[version], NULL);
|
|
spin_unlock(&gre_proto_lock);
|
|
synchronize_rcu();
|
|
return 0;
|
|
|
|
err_out_unlock:
|
|
spin_unlock(&gre_proto_lock);
|
|
err_out:
|
|
return -1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gre_del_protocol);
|
|
|
|
static int gre_rcv(struct sk_buff *skb)
|
|
{
|
|
const struct gre_protocol *proto;
|
|
u8 ver;
|
|
int ret;
|
|
|
|
if (!pskb_may_pull(skb, 12))
|
|
goto drop;
|
|
|
|
ver = skb->data[1]&0x7f;
|
|
if (ver >= GREPROTO_MAX)
|
|
goto drop;
|
|
|
|
rcu_read_lock();
|
|
proto = rcu_dereference(gre_proto[ver]);
|
|
if (!proto || !proto->handler)
|
|
goto drop_unlock;
|
|
ret = proto->handler(skb);
|
|
rcu_read_unlock();
|
|
return ret;
|
|
|
|
drop_unlock:
|
|
rcu_read_unlock();
|
|
drop:
|
|
kfree_skb(skb);
|
|
return NET_RX_DROP;
|
|
}
|
|
|
|
static void gre_err(struct sk_buff *skb, u32 info)
|
|
{
|
|
const struct gre_protocol *proto;
|
|
u8 ver;
|
|
|
|
if (!pskb_may_pull(skb, 12))
|
|
goto drop;
|
|
|
|
ver = skb->data[1]&0x7f;
|
|
if (ver >= GREPROTO_MAX)
|
|
goto drop;
|
|
|
|
rcu_read_lock();
|
|
proto = rcu_dereference(gre_proto[ver]);
|
|
if (!proto || !proto->err_handler)
|
|
goto drop_unlock;
|
|
proto->err_handler(skb, info);
|
|
rcu_read_unlock();
|
|
return;
|
|
|
|
drop_unlock:
|
|
rcu_read_unlock();
|
|
drop:
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
static const struct net_protocol net_gre_protocol = {
|
|
.handler = gre_rcv,
|
|
.err_handler = gre_err,
|
|
.netns_ok = 1,
|
|
};
|
|
|
|
static int __init gre_init(void)
|
|
{
|
|
pr_info("GRE over IPv4 demultiplexor driver");
|
|
|
|
if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
|
|
pr_err("gre: can't add protocol\n");
|
|
return -EAGAIN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit gre_exit(void)
|
|
{
|
|
inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
|
|
}
|
|
|
|
module_init(gre_init);
|
|
module_exit(gre_exit);
|
|
|
|
MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver");
|
|
MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
|
|
MODULE_LICENSE("GPL");
|
|
|