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|
/*
* lwtunnel Infrastructure for light weight tunnels like mpls
*
* Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
*
* 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/capability.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/lwtunnel.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/err.h>
#include <net/lwtunnel.h>
#include <net/rtnetlink.h>
#include <net/ip6_fib.h>
#ifdef CONFIG_MODULES
static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
{
/* Only lwt encaps implemented without using an interface for
* the encap need to return a string here.
*/
switch (encap_type) {
case LWTUNNEL_ENCAP_MPLS:
return "MPLS";
case LWTUNNEL_ENCAP_ILA:
return "ILA";
case LWTUNNEL_ENCAP_SEG6:
return "SEG6";
case LWTUNNEL_ENCAP_BPF:
return "BPF";
case LWTUNNEL_ENCAP_IP6:
case LWTUNNEL_ENCAP_IP:
case LWTUNNEL_ENCAP_NONE:
case __LWTUNNEL_ENCAP_MAX:
/* should not have got here */
WARN_ON(1);
break;
}
return NULL;
}
#endif /* CONFIG_MODULES */
struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
{
struct lwtunnel_state *lws;
lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
return lws;
}
EXPORT_SYMBOL(lwtunnel_state_alloc);
static const struct lwtunnel_encap_ops __rcu *
lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
unsigned int num)
{
if (num > LWTUNNEL_ENCAP_MAX)
return -ERANGE;
return !cmpxchg((const struct lwtunnel_encap_ops **)
&lwtun_encaps[num],
NULL, ops) ? 0 : -1;
}
EXPORT_SYMBOL(lwtunnel_encap_add_ops);
int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
unsigned int encap_type)
{
int ret;
if (encap_type == LWTUNNEL_ENCAP_NONE ||
encap_type > LWTUNNEL_ENCAP_MAX)
return -ERANGE;
ret = (cmpxchg((const struct lwtunnel_encap_ops **)
&lwtun_encaps[encap_type],
ops, NULL) == ops) ? 0 : -1;
synchronize_net();
return ret;
}
EXPORT_SYMBOL(lwtunnel_encap_del_ops);
int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
struct nlattr *encap, unsigned int family,
const void *cfg, struct lwtunnel_state **lws)
{
const struct lwtunnel_encap_ops *ops;
int ret = -EINVAL;
if (encap_type == LWTUNNEL_ENCAP_NONE ||
encap_type > LWTUNNEL_ENCAP_MAX)
return ret;
ret = -EOPNOTSUPP;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[encap_type]);
#ifdef CONFIG_MODULES
if (!ops) {
const char *encap_type_str = lwtunnel_encap_str(encap_type);
if (encap_type_str) {
rcu_read_unlock();
request_module("rtnl-lwt-%s", encap_type_str);
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[encap_type]);
}
}
#endif
if (likely(ops && ops->build_state))
ret = ops->build_state(dev, encap, family, cfg, lws);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(lwtunnel_build_state);
void lwtstate_free(struct lwtunnel_state *lws)
{
const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
if (ops->destroy_state) {
ops->destroy_state(lws);
kfree_rcu(lws, rcu);
} else {
kfree(lws);
}
}
EXPORT_SYMBOL(lwtstate_free);
int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate)
{
const struct lwtunnel_encap_ops *ops;
struct nlattr *nest;
int ret = -EINVAL;
if (!lwtstate)
return 0;
if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
lwtstate->type > LWTUNNEL_ENCAP_MAX)
return 0;
ret = -EOPNOTSUPP;
nest = nla_nest_start(skb, RTA_ENCAP);
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
if (likely(ops && ops->fill_encap))
ret = ops->fill_encap(skb, lwtstate);
rcu_read_unlock();
if (ret)
goto nla_put_failure;
nla_nest_end(skb, nest);
ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type);
if (ret)
goto nla_put_failure;
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return (ret == -EOPNOTSUPP ? 0 : ret);
}
EXPORT_SYMBOL(lwtunnel_fill_encap);
int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
{
const struct lwtunnel_encap_ops *ops;
int ret = 0;
if (!lwtstate)
return 0;
if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
lwtstate->type > LWTUNNEL_ENCAP_MAX)
return 0;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
if (likely(ops && ops->get_encap_size))
ret = nla_total_size(ops->get_encap_size(lwtstate));
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(lwtunnel_get_encap_size);
int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
const struct lwtunnel_encap_ops *ops;
int ret = 0;
if (!a && !b)
return 0;
if (!a || !b)
return 1;
if (a->type != b->type)
return 1;
if (a->type == LWTUNNEL_ENCAP_NONE ||
a->type > LWTUNNEL_ENCAP_MAX)
return 0;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[a->type]);
if (likely(ops && ops->cmp_encap))
ret = ops->cmp_encap(a, b);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(lwtunnel_cmp_encap);
int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
const struct lwtunnel_encap_ops *ops;
struct lwtunnel_state *lwtstate;
int ret = -EINVAL;
if (!dst)
goto drop;
lwtstate = dst->lwtstate;
if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
lwtstate->type > LWTUNNEL_ENCAP_MAX)
return 0;
ret = -EOPNOTSUPP;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
if (likely(ops && ops->output))
ret = ops->output(net, sk, skb);
rcu_read_unlock();
if (ret == -EOPNOTSUPP)
goto drop;
return ret;
drop:
kfree_skb(skb);
return ret;
}
EXPORT_SYMBOL(lwtunnel_output);
int lwtunnel_xmit(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
const struct lwtunnel_encap_ops *ops;
struct lwtunnel_state *lwtstate;
int ret = -EINVAL;
if (!dst)
goto drop;
lwtstate = dst->lwtstate;
if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
lwtstate->type > LWTUNNEL_ENCAP_MAX)
return 0;
ret = -EOPNOTSUPP;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
if (likely(ops && ops->xmit))
ret = ops->xmit(skb);
rcu_read_unlock();
if (ret == -EOPNOTSUPP)
goto drop;
return ret;
drop:
kfree_skb(skb);
return ret;
}
EXPORT_SYMBOL(lwtunnel_xmit);
int lwtunnel_input(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
const struct lwtunnel_encap_ops *ops;
struct lwtunnel_state *lwtstate;
int ret = -EINVAL;
if (!dst)
goto drop;
lwtstate = dst->lwtstate;
if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
lwtstate->type > LWTUNNEL_ENCAP_MAX)
return 0;
ret = -EOPNOTSUPP;
rcu_read_lock();
ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
if (likely(ops && ops->input))
ret = ops->input(skb);
rcu_read_unlock();
if (ret == -EOPNOTSUPP)
goto drop;
return ret;
drop:
kfree_skb(skb);
return ret;
}
EXPORT_SYMBOL(lwtunnel_input);
|
