/* SPDX-License-Identifier: GPL-2.0 */
/*
* Multipath TCP
*
* Copyright (c) 2017 - 2019, Intel Corporation.
*/
#ifndef __NET_MPTCP_H
#define __NET_MPTCP_H
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/types.h>
/* MPTCP sk_buff extension data */
struct mptcp_ext {
u64 data_ack;
u64 data_seq;
u32 subflow_seq;
u16 data_len;
u8 use_map:1,
dsn64:1,
data_fin:1,
use_ack:1,
ack64:1,
mpc_map:1,
__unused:2;
/* one byte hole */
};
struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
u16 suboptions;
u64 sndr_key;
u64 rcvr_key;
struct mptcp_ext ext_copy;
#endif
};
#ifdef CONFIG_MPTCP
void mptcp_init(void);
static inline bool sk_is_mptcp(const struct sock *sk)
{
return tcp_sk(sk)->is_mptcp;
}
static inline bool rsk_is_mptcp(const struct request_sock *req)
{
return tcp_rsk(req)->is_mptcp;
}
void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr,
int opsize, struct tcp_options_received *opt_rx);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
unsigned int *size, struct mptcp_out_options *opts);
void mptcp_rcv_synsent(struct sock *sk);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
struct mptcp_out_options *opts);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
unsigned int *size, unsigned int remaining,
struct mptcp_out_options *opts);
void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
struct tcp_options_received *opt_rx);
void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts);
/* move the skb extension owership, with the assumption that 'to' is
* newly allocated
*/
static inline void mptcp_skb_ext_move(struct sk_buff *to,
struct sk_buff *from)
{
if (!skb_ext_exist(from, SKB_EXT_MPTCP))
return;
if (WARN_ON_ONCE(to->active_extensions))
skb_ext_put(to);
to->active_extensions = from->active_extensions;
to->extensions = from->extensions;
from->active_extensions = 0;
}
static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
const struct mptcp_ext *from_ext)
{
/* MPTCP always clears the ext when adding it to the skb, so
* holes do not bother us here
*/
return !from_ext ||
(to_ext && from_ext &&
!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
}
/* check if skbs can be collapsed.
* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
* mapping, or if the extension of @to is the same as @from.
* Collapsing is not possible if @to lacks an extension, but @from carries one.
*/
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
skb_ext_find(from, SKB_EXT_MPTCP));
}
#else
static inline void mptcp_init(void)
{
}
static inline bool sk_is_mptcp(const struct sock *sk)
{
return false;
}
static inline bool rsk_is_mptcp(const struct request_sock *req)
{
return false;
}
static inline void mptcp_parse_option(const struct sk_buff *skb,
const unsigned char *ptr, int opsize,
struct tcp_options_received *opt_rx)
{
}
static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
unsigned int *size,
struct mptcp_out_options *opts)
{
return false;
}
static inline void mptcp_rcv_synsent(struct sock *sk)
{
}
static inline bool mptcp_synack_options(const struct request_sock *req,
unsigned int *size,
struct mptcp_out_options *opts)
{
return false;
}
static inline bool mptcp_established_options(struct sock *sk,
struct sk_buff *skb,
unsigned int *size,
unsigned int remaining,
struct mptcp_out_options *opts)
{
return false;
}
static inline void mptcp_incoming_options(struct sock *sk,
struct sk_buff *skb,
struct tcp_options_received *opt_rx)
{
}
static inline void mptcp_skb_ext_move(struct sk_buff *to,
const struct sk_buff *from)
{
}
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return true;
}
#endif /* CONFIG_MPTCP */
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#endif
#endif /* __NET_MPTCP_H */