include/net/mptcp.h - linux - Git at Google

 /* 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>

 struct mptcp_info;
 struct mptcp_sock;
 struct seq_file;

 /* MPTCP sk_buff extension data */
 struct mptcp_ext {
 	union {
 		u64	data_ack;
 		u32	data_ack32;
 	};
 	u64		data_seq;
 	u32		subflow_seq;
 	u16		data_len;
 	__sum16		csum;
 	u8		use_map:1,
 			dsn64:1,
 			data_fin:1,
 			use_ack:1,
 			ack64:1,
 			mpc_map:1,
 			frozen:1,
 			reset_transient:1;
 	u8		reset_reason:4,
 			csum_reqd:1,
 			infinite_map:1;
 };

 #define MPTCPOPT_HMAC_LEN	20
 #define MPTCP_RM_IDS_MAX	8

 struct mptcp_rm_list {
 	u8 ids[MPTCP_RM_IDS_MAX];
 	u8 nr;
 };

 struct mptcp_addr_info {
 	u8			id;
 	sa_family_t		family;
 	__be16			port;
 	union {
 		struct in_addr	addr;
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 		struct in6_addr	addr6;
 #endif
 	};
 };

 struct mptcp_out_options {
 #if IS_ENABLED(CONFIG_MPTCP)
 	u16 suboptions;
 	struct mptcp_rm_list rm_list;
 	u8 join_id;
 	u8 backup;
 	u8 reset_reason:4,
 	   reset_transient:1,
 	   csum_reqd:1,
 	   allow_join_id0:1;
 	union {
 		struct {
 			u64 sndr_key;
 			u64 rcvr_key;
 			u64 data_seq;
 			u32 subflow_seq;
 			u16 data_len;
 			__sum16 csum;
 		};
 		struct {
 			struct mptcp_addr_info addr;
 			u64 ahmac;
 		};
 		struct {
 			struct mptcp_ext ext_copy;
 			u64 fail_seq;
 		};
 		struct {
 			u32 nonce;
 			u32 token;
 			u64 thmac;
 			u8 hmac[MPTCPOPT_HMAC_LEN];
 		};
 	};
 #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;
 }

 static inline bool rsk_drop_req(const struct request_sock *req)
 {
 	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
 }

 void mptcp_space(const struct sock *ssk, int *space, int *full_space);
 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
 		       unsigned int *size, struct mptcp_out_options *opts);
 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);
 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);

 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
 			 struct mptcp_out_options *opts);

 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);

 /* 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 void mptcp_skb_ext_copy(struct sk_buff *to,
 				      struct sk_buff *from)
 {
 	struct mptcp_ext *from_ext;

 	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
 	if (!from_ext)
 		return;

 	from_ext->frozen = 1;
 	skb_ext_copy(to, from);
 }

 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));
 }

 void mptcp_seq_show(struct seq_file *seq);
 int mptcp_subflow_init_cookie_req(struct request_sock *req,
 				  const struct sock *sk_listener,
 				  struct sk_buff *skb);
 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
 					       struct sock *sk_listener,
 					       bool attach_listener);

 __be32 mptcp_get_reset_option(const struct sk_buff *skb);

 static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
 {
 	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
 		return mptcp_get_reset_option(skb);

 	return htonl(0u);
 }
 #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 bool rsk_drop_req(const struct request_sock *req)
 {
 	return false;
 }

 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 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 bool mptcp_incoming_options(struct sock *sk,
 					  struct sk_buff *skb)
 {
 	return true;
 }

 static inline void mptcp_skb_ext_move(struct sk_buff *to,
 				      const struct sk_buff *from)
 {
 }

 static inline void mptcp_skb_ext_copy(struct sk_buff *to,
 				      struct sk_buff *from)
 {
 }

 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
 					  const struct sk_buff *from)
 {
 	return true;
 }

 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
 static inline void mptcp_seq_show(struct seq_file *seq) { }

 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
 						const struct sock *sk_listener,
 						struct sk_buff *skb)
 {
 	return 0; /* TCP fallback */
 }

 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
 							     struct sock *sk_listener,
 							     bool attach_listener)
 {
 	return NULL;
 }

 static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return htonl(0u); }
 #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

 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
 #else
 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
 #endif

 #if !IS_ENABLED(CONFIG_MPTCP)
 struct mptcp_sock { };
 #endif

 #endif /* __NET_MPTCP_H */
	/* 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>

	struct mptcp_info;
	struct mptcp_sock;
	struct seq_file;

	/* MPTCP sk_buff extension data */
	struct mptcp_ext {
	union {
	u64 data_ack;
	u32 data_ack32;
	};
	u64 data_seq;
	u32 subflow_seq;
	u16 data_len;
	__sum16 csum;
	u8 use_map:1,
	dsn64:1,
	data_fin:1,
	use_ack:1,
	ack64:1,
	mpc_map:1,
	frozen:1,
	reset_transient:1;
	u8 reset_reason:4,
	csum_reqd:1,
	infinite_map:1;
	};

	#define MPTCPOPT_HMAC_LEN 20
	#define MPTCP_RM_IDS_MAX 8

	struct mptcp_rm_list {
	u8 ids[MPTCP_RM_IDS_MAX];
	u8 nr;
	};

	struct mptcp_addr_info {
	u8 id;
	sa_family_t family;
	__be16 port;
	union {
	struct in_addr addr;
	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	struct in6_addr addr6;
	#endif
	};
	};

	struct mptcp_out_options {
	#if IS_ENABLED(CONFIG_MPTCP)
	u16 suboptions;
	struct mptcp_rm_list rm_list;
	u8 join_id;
	u8 backup;
	u8 reset_reason:4,
	reset_transient:1,
	csum_reqd:1,
	allow_join_id0:1;
	union {
	struct {
	u64 sndr_key;
	u64 rcvr_key;
	u64 data_seq;
	u32 subflow_seq;
	u16 data_len;
	__sum16 csum;
	};
	struct {
	struct mptcp_addr_info addr;
	u64 ahmac;
	};
	struct {
	struct mptcp_ext ext_copy;
	u64 fail_seq;
	};
	struct {
	u32 nonce;
	u32 token;
	u64 thmac;
	u8 hmac[MPTCPOPT_HMAC_LEN];
	};
	};
	#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;
	}

	static inline bool rsk_drop_req(const struct request_sock *req)
	{
	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	}

	void mptcp_space(const struct sock ssk, int space, int *full_space);
	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
	unsigned int size, struct mptcp_out_options opts);
	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);
	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);

	void mptcp_write_options(struct tcphdr th, __be32 ptr, struct tcp_sock *tp,
	struct mptcp_out_options *opts);

	void mptcp_diag_fill_info(struct mptcp_sock msk, struct mptcp_info info);

	/* 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 void mptcp_skb_ext_copy(struct sk_buff *to,
	struct sk_buff *from)
	{
	struct mptcp_ext *from_ext;

	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	if (!from_ext)
	return;

	from_ext->frozen = 1;
	skb_ext_copy(to, from);
	}

	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));
	}

	void mptcp_seq_show(struct seq_file *seq);
	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	const struct sock *sk_listener,
	struct sk_buff *skb);
	struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	struct sock *sk_listener,
	bool attach_listener);

	__be32 mptcp_get_reset_option(const struct sk_buff *skb);

	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	{
	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	return mptcp_get_reset_option(skb);

	return htonl(0u);
	}
	#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 bool rsk_drop_req(const struct request_sock *req)
	{
	return false;
	}

	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 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 bool mptcp_incoming_options(struct sock *sk,
	struct sk_buff *skb)
	{
	return true;
	}

	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	const struct sk_buff *from)
	{
	}

	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	struct sk_buff *from)
	{
	}

	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	const struct sk_buff *from)
	{
	return true;
	}

	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
	static inline void mptcp_seq_show(struct seq_file *seq) { }

	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	const struct sock *sk_listener,
	struct sk_buff *skb)
	{
	return 0; /* TCP fallback */
	}

	static inline struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	struct sock *sk_listener,
	bool attach_listener)
	{
	return NULL;
	}

	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
	#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

	#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
	struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk);
	#else
	static inline struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk) { return NULL; }
	#endif

	#if !IS_ENABLED(CONFIG_MPTCP)
	struct mptcp_sock { };
	#endif

	#endif /* __NET_MPTCP_H */