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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_LWTUNNEL_H
#define __NET_LWTUNNEL_H 1
#include <linux/lwtunnel.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/route.h>
#define LWTUNNEL_HASH_BITS 7
#define LWTUNNEL_HASH_SIZE (1 << LWTUNNEL_HASH_BITS)
/* lw tunnel state flags */
#define LWTUNNEL_STATE_OUTPUT_REDIRECT BIT(0)
#define LWTUNNEL_STATE_INPUT_REDIRECT BIT(1)
#define LWTUNNEL_STATE_XMIT_REDIRECT BIT(2)
/* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return
* values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety.
*/
enum {
LWTUNNEL_XMIT_DONE,
LWTUNNEL_XMIT_CONTINUE = 0x100,
};
struct lwtunnel_state {
__u16 type;
__u16 flags;
__u16 headroom;
atomic_t refcnt;
int (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
int (*orig_input)(struct sk_buff *);
struct rcu_head rcu;
__u8 data[];
};
struct lwtunnel_encap_ops {
int (*build_state)(struct net *net, struct nlattr *encap,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack);
void (*destroy_state)(struct lwtunnel_state *lws);
int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
int (*input)(struct sk_buff *skb);
int (*fill_encap)(struct sk_buff *skb,
struct lwtunnel_state *lwtstate);
int (*get_encap_size)(struct lwtunnel_state *lwtstate);
int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
int (*xmit)(struct sk_buff *skb);
struct module *owner;
};
#ifdef CONFIG_LWTUNNEL
DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
void lwtstate_free(struct lwtunnel_state *lws);
static inline struct lwtunnel_state *
lwtstate_get(struct lwtunnel_state *lws)
{
if (lws)
atomic_inc(&lws->refcnt);
return lws;
}
static inline void lwtstate_put(struct lwtunnel_state *lws)
{
if (!lws)
return;
if (atomic_dec_and_test(&lws->refcnt))
lwtstate_free(lws);
}
static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
{
if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
return true;
return false;
}
static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
{
if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
return true;
return false;
}
static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
{
if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
return true;
return false;
}
static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
unsigned int mtu)
{
if ((lwtunnel_xmit_redirect(lwtstate) ||
lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
return lwtstate->headroom;
return 0;
}
int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
unsigned int num);
int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
unsigned int num);
int lwtunnel_valid_encap_type(u16 encap_type,
struct netlink_ext_ack *extack);
int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
struct netlink_ext_ack *extack);
int lwtunnel_build_state(struct net *net, u16 encap_type,
struct nlattr *encap,
unsigned int family, const void *cfg,
struct lwtunnel_state **lws,
struct netlink_ext_ack *extack);
int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
int encap_attr, int encap_type_attr);
int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
int lwtunnel_input(struct sk_buff *skb);
int lwtunnel_xmit(struct sk_buff *skb);
int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
bool ingress);
static inline void lwtunnel_set_redirect(struct dst_entry *dst)
{
if (lwtunnel_output_redirect(dst->lwtstate)) {
dst->lwtstate->orig_output = dst->output;
dst->output = lwtunnel_output;
}
if (lwtunnel_input_redirect(dst->lwtstate)) {
dst->lwtstate->orig_input = dst->input;
dst->input = lwtunnel_input;
}
}
#else
static inline void lwtstate_free(struct lwtunnel_state *lws)
{
}
static inline struct lwtunnel_state *
lwtstate_get(struct lwtunnel_state *lws)
{
return lws;
}
static inline void lwtstate_put(struct lwtunnel_state *lws)
{
}
static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
{
return false;
}
static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
{
return false;
}
static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
{
return false;
}
static inline void lwtunnel_set_redirect(struct dst_entry *dst)
{
}
static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
unsigned int mtu)
{
return 0;
}
static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
unsigned int num)
{
return -EOPNOTSUPP;
}
static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
unsigned int num)
{
return -EOPNOTSUPP;
}
static inline int lwtunnel_valid_encap_type(u16 encap_type,
struct netlink_ext_ack *extack)
{
NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
return -EOPNOTSUPP;
}
static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
struct netlink_ext_ack *extack)
{
/* return 0 since we are not walking attr looking for
* RTA_ENCAP_TYPE attribute on nexthops.
*/
return 0;
}
static inline int lwtunnel_build_state(struct net *net, u16 encap_type,
struct nlattr *encap,
unsigned int family, const void *cfg,
struct lwtunnel_state **lws,
struct netlink_ext_ack *extack)
{
return -EOPNOTSUPP;
}
static inline int lwtunnel_fill_encap(struct sk_buff *skb,
struct lwtunnel_state *lwtstate,
int encap_attr, int encap_type_attr)
{
return 0;
}
static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
{
return 0;
}
static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
{
return NULL;
}
static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
struct lwtunnel_state *b)
{
return 0;
}
static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
return -EOPNOTSUPP;
}
static inline int lwtunnel_input(struct sk_buff *skb)
{
return -EOPNOTSUPP;
}
static inline int lwtunnel_xmit(struct sk_buff *skb)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_LWTUNNEL */
#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
#endif /* __NET_LWTUNNEL_H */
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