Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1038 insertions, 0 deletions

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
new file mode 100644
index 000000000..4ec8e0a81
--- /dev/null
+++ b/net/mptcp/protocol.h
@@ -0,0 +1,1038 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Multipath TCP
+ *
+ * Copyright (c) 2017 - 2019, Intel Corporation.
+ */
+
+#ifndef __MPTCP_PROTOCOL_H
+#define __MPTCP_PROTOCOL_H
+
+#include <linux/random.h>
+#include <net/tcp.h>
+#include <net/inet_connection_sock.h>
+#include <uapi/linux/mptcp.h>
+#include <net/genetlink.h>
+
+#define MPTCP_SUPPORTED_VERSION	1
+
+/* MPTCP option bits */
+#define OPTION_MPTCP_MPC_SYN	BIT(0)
+#define OPTION_MPTCP_MPC_SYNACK	BIT(1)
+#define OPTION_MPTCP_MPC_ACK	BIT(2)
+#define OPTION_MPTCP_MPJ_SYN	BIT(3)
+#define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
+#define OPTION_MPTCP_MPJ_ACK	BIT(5)
+#define OPTION_MPTCP_ADD_ADDR	BIT(6)
+#define OPTION_MPTCP_RM_ADDR	BIT(7)
+#define OPTION_MPTCP_FASTCLOSE	BIT(8)
+#define OPTION_MPTCP_PRIO	BIT(9)
+#define OPTION_MPTCP_RST	BIT(10)
+#define OPTION_MPTCP_DSS	BIT(11)
+#define OPTION_MPTCP_FAIL	BIT(12)
+
+#define OPTION_MPTCP_CSUMREQD	BIT(13)
+
+#define OPTIONS_MPTCP_MPC	(OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
+				 OPTION_MPTCP_MPC_ACK)
+#define OPTIONS_MPTCP_MPJ	(OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
+				 OPTION_MPTCP_MPJ_ACK)
+
+/* MPTCP option subtypes */
+#define MPTCPOPT_MP_CAPABLE	0
+#define MPTCPOPT_MP_JOIN	1
+#define MPTCPOPT_DSS		2
+#define MPTCPOPT_ADD_ADDR	3
+#define MPTCPOPT_RM_ADDR	4
+#define MPTCPOPT_MP_PRIO	5
+#define MPTCPOPT_MP_FAIL	6
+#define MPTCPOPT_MP_FASTCLOSE	7
+#define MPTCPOPT_RST		8
+
+/* MPTCP suboption lengths */
+#define TCPOLEN_MPTCP_MPC_SYN		4
+#define TCPOLEN_MPTCP_MPC_SYNACK	12
+#define TCPOLEN_MPTCP_MPC_ACK		20
+#define TCPOLEN_MPTCP_MPC_ACK_DATA	22
+#define TCPOLEN_MPTCP_MPJ_SYN		12
+#define TCPOLEN_MPTCP_MPJ_SYNACK	16
+#define TCPOLEN_MPTCP_MPJ_ACK		24
+#define TCPOLEN_MPTCP_DSS_BASE		4
+#define TCPOLEN_MPTCP_DSS_ACK32		4
+#define TCPOLEN_MPTCP_DSS_ACK64		8
+#define TCPOLEN_MPTCP_DSS_MAP32		10
+#define TCPOLEN_MPTCP_DSS_MAP64		14
+#define TCPOLEN_MPTCP_DSS_CHECKSUM	2
+#define TCPOLEN_MPTCP_ADD_ADDR		16
+#define TCPOLEN_MPTCP_ADD_ADDR_PORT	18
+#define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
+#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	10
+#define TCPOLEN_MPTCP_ADD_ADDR6		28
+#define TCPOLEN_MPTCP_ADD_ADDR6_PORT	30
+#define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
+#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	22
+#define TCPOLEN_MPTCP_PORT_LEN		2
+#define TCPOLEN_MPTCP_PORT_ALIGN	2
+#define TCPOLEN_MPTCP_RM_ADDR_BASE	3
+#define TCPOLEN_MPTCP_PRIO		3
+#define TCPOLEN_MPTCP_PRIO_ALIGN	4
+#define TCPOLEN_MPTCP_FASTCLOSE		12
+#define TCPOLEN_MPTCP_RST		4
+#define TCPOLEN_MPTCP_FAIL		12
+
+#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM	(TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
+
+/* MPTCP MP_JOIN flags */
+#define MPTCPOPT_BACKUP		BIT(0)
+#define MPTCPOPT_THMAC_LEN	8
+
+/* MPTCP MP_CAPABLE flags */
+#define MPTCP_VERSION_MASK	(0x0F)
+#define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
+#define MPTCP_CAP_EXTENSIBILITY	BIT(6)
+#define MPTCP_CAP_DENY_JOIN_ID0	BIT(5)
+#define MPTCP_CAP_HMAC_SHA256	BIT(0)
+#define MPTCP_CAP_FLAG_MASK	(0x1F)
+
+/* MPTCP DSS flags */
+#define MPTCP_DSS_DATA_FIN	BIT(4)
+#define MPTCP_DSS_DSN64		BIT(3)
+#define MPTCP_DSS_HAS_MAP	BIT(2)
+#define MPTCP_DSS_ACK64		BIT(1)
+#define MPTCP_DSS_HAS_ACK	BIT(0)
+#define MPTCP_DSS_FLAG_MASK	(0x1F)
+
+/* MPTCP ADD_ADDR flags */
+#define MPTCP_ADDR_ECHO		BIT(0)
+
+/* MPTCP MP_PRIO flags */
+#define MPTCP_PRIO_BKUP		BIT(0)
+
+/* MPTCP TCPRST flags */
+#define MPTCP_RST_TRANSIENT	BIT(0)
+
+/* MPTCP socket atomic flags */
+#define MPTCP_NOSPACE		1
+#define MPTCP_WORK_RTX		2
+#define MPTCP_WORK_EOF		3
+#define MPTCP_FALLBACK_DONE	4
+#define MPTCP_WORK_CLOSE_SUBFLOW 5
+
+/* MPTCP socket release cb flags */
+#define MPTCP_PUSH_PENDING	1
+#define MPTCP_CLEAN_UNA		2
+#define MPTCP_ERROR_REPORT	3
+#define MPTCP_RETRANSMIT	4
+#define MPTCP_FLUSH_JOIN_LIST	5
+#define MPTCP_CONNECTED		6
+#define MPTCP_RESET_SCHEDULER	7
+
+static inline bool before64(__u64 seq1, __u64 seq2)
+{
+	return (__s64)(seq1 - seq2) < 0;
+}
+
+#define after64(seq2, seq1)	before64(seq1, seq2)
+
+struct mptcp_options_received {
+	u64	sndr_key;
+	u64	rcvr_key;
+	u64	data_ack;
+	u64	data_seq;
+	u32	subflow_seq;
+	u16	data_len;
+	__sum16	csum;
+	u16	suboptions;
+	u32	token;
+	u32	nonce;
+	u16	use_map:1,
+		dsn64:1,
+		data_fin:1,
+		use_ack:1,
+		ack64:1,
+		mpc_map:1,
+		reset_reason:4,
+		reset_transient:1,
+		echo:1,
+		backup:1,
+		deny_join_id0:1,
+		__unused:2;
+	u8	join_id;
+	u64	thmac;
+	u8	hmac[MPTCPOPT_HMAC_LEN];
+	struct mptcp_addr_info addr;
+	struct mptcp_rm_list rm_list;
+	u64	ahmac;
+	u64	fail_seq;
+};
+
+static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
+{
+	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
+		     ((nib & 0xF) << 8) | field);
+}
+
+enum mptcp_pm_status {
+	MPTCP_PM_ADD_ADDR_RECEIVED,
+	MPTCP_PM_ADD_ADDR_SEND_ACK,
+	MPTCP_PM_RM_ADDR_RECEIVED,
+	MPTCP_PM_ESTABLISHED,
+	MPTCP_PM_SUBFLOW_ESTABLISHED,
+	MPTCP_PM_ALREADY_ESTABLISHED,	/* persistent status, set after ESTABLISHED event */
+	MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
+					 * accounted int id_avail_bitmap
+					 */
+};
+
+enum mptcp_pm_type {
+	MPTCP_PM_TYPE_KERNEL = 0,
+	MPTCP_PM_TYPE_USERSPACE,
+
+	__MPTCP_PM_TYPE_NR,
+	__MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
+};
+
+/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
+#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
+
+enum mptcp_addr_signal_status {
+	MPTCP_ADD_ADDR_SIGNAL,
+	MPTCP_ADD_ADDR_ECHO,
+	MPTCP_RM_ADDR_SIGNAL,
+};
+
+/* max value of mptcp_addr_info.id */
+#define MPTCP_PM_MAX_ADDR_ID		U8_MAX
+
+struct mptcp_pm_data {
+	struct mptcp_addr_info local;
+	struct mptcp_addr_info remote;
+	struct list_head anno_list;
+	struct list_head userspace_pm_local_addr_list;
+
+	spinlock_t	lock;		/*protects the whole PM data */
+
+	u8		addr_signal;
+	bool		server_side;
+	bool		work_pending;
+	bool		accept_addr;
+	bool		accept_subflow;
+	bool		remote_deny_join_id0;
+	u8		add_addr_signaled;
+	u8		add_addr_accepted;
+	u8		local_addr_used;
+	u8		pm_type;
+	u8		subflows;
+	u8		status;
+	DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
+	struct mptcp_rm_list rm_list_tx;
+	struct mptcp_rm_list rm_list_rx;
+};
+
+struct mptcp_pm_addr_entry {
+	struct list_head	list;
+	struct mptcp_addr_info	addr;
+	u8			flags;
+	int			ifindex;
+	struct socket		*lsk;
+};
+
+struct mptcp_data_frag {
+	struct list_head list;
+	u64 data_seq;
+	u16 data_len;
+	u16 offset;
+	u16 overhead;
+	u16 already_sent;
+	struct page *page;
+};
+
+/* MPTCP connection sock */
+struct mptcp_sock {
+	/* inet_connection_sock must be the first member */
+	struct inet_connection_sock sk;
+	u64		local_key;
+	u64		remote_key;
+	u64		write_seq;
+	u64		snd_nxt;
+	u64		ack_seq;
+	atomic64_t	rcv_wnd_sent;
+	u64		rcv_data_fin_seq;
+	int		rmem_fwd_alloc;
+	struct sock	*last_snd;
+	int		snd_burst;
+	int		old_wspace;
+	u64		recovery_snd_nxt;	/* in recovery mode accept up to this seq;
+						 * recovery related fields are under data_lock
+						 * protection
+						 */
+	u64		snd_una;
+	u64		wnd_end;
+	unsigned long	timer_ival;
+	u32		token;
+	int		rmem_released;
+	unsigned long	flags;
+	unsigned long	cb_flags;
+	unsigned long	push_pending;
+	bool		recovery;		/* closing subflow write queue reinjected */
+	bool		can_ack;
+	bool		fully_established;
+	bool		rcv_data_fin;
+	bool		snd_data_fin_enable;
+	bool		rcv_fastclose;
+	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */
+	bool		csum_enabled;
+	bool		allow_infinite_fallback;
+	u8		mpc_endpoint_id;
+	u8		recvmsg_inq:1,
+			cork:1,
+			nodelay:1,
+			fastopening:1,
+			in_accept_queue:1;
+	struct work_struct work;
+	struct sk_buff  *ooo_last_skb;
+	struct rb_root  out_of_order_queue;
+	struct sk_buff_head receive_queue;
+	struct list_head conn_list;
+	struct list_head rtx_queue;
+	struct mptcp_data_frag *first_pending;
+	struct list_head join_list;
+	struct socket	*subflow; /* outgoing connect/listener/!mp_capable
+				   * The mptcp ops can safely dereference, using suitable
+				   * ONCE annotation, the subflow outside the socket
+				   * lock as such sock is freed after close().
+				   */
+	struct sock	*first;
+	struct mptcp_pm_data	pm;
+	struct {
+		u32	space;	/* bytes copied in last measurement window */
+		u32	copied; /* bytes copied in this measurement window */
+		u64	time;	/* start time of measurement window */
+		u64	rtt_us; /* last maximum rtt of subflows */
+	} rcvq_space;
+
+	u32 setsockopt_seq;
+	char		ca_name[TCP_CA_NAME_MAX];
+};
+
+#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
+#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
+
+#define mptcp_for_each_subflow(__msk, __subflow)			\
+	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
+#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp)			\
+	list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
+
+static inline void msk_owned_by_me(const struct mptcp_sock *msk)
+{
+	sock_owned_by_me((const struct sock *)msk);
+}
+
+static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
+{
+	return (struct mptcp_sock *)sk;
+}
+
+/* the msk socket don't use the backlog, also account for the bulk
+ * free memory
+ */
+static inline int __mptcp_rmem(const struct sock *sk)
+{
+	return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
+}
+
+static inline int __mptcp_space(const struct sock *sk)
+{
+	return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
+}
+
+static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
+{
+	const struct mptcp_sock *msk = mptcp_sk(sk);
+
+	return READ_ONCE(msk->first_pending);
+}
+
+static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct mptcp_data_frag *cur;
+
+	cur = msk->first_pending;
+	return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
+						     list_next_entry(cur, list);
+}
+
+static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+
+	if (!msk->first_pending)
+		return NULL;
+
+	if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
+		return NULL;
+
+	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
+}
+
+static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+
+	if (msk->snd_una == READ_ONCE(msk->snd_nxt))
+		return NULL;
+
+	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
+}
+
+struct csum_pseudo_header {
+	__be64 data_seq;
+	__be32 subflow_seq;
+	__be16 data_len;
+	__sum16 csum;
+};
+
+struct mptcp_subflow_request_sock {
+	struct	tcp_request_sock sk;
+	u16	mp_capable : 1,
+		mp_join : 1,
+		backup : 1,
+		csum_reqd : 1,
+		allow_join_id0 : 1;
+	u8	local_id;
+	u8	remote_id;
+	u64	local_key;
+	u64	idsn;
+	u32	token;
+	u32	ssn_offset;
+	u64	thmac;
+	u32	local_nonce;
+	u32	remote_nonce;
+	struct mptcp_sock	*msk;
+	struct hlist_nulls_node token_node;
+};
+
+static inline struct mptcp_subflow_request_sock *
+mptcp_subflow_rsk(const struct request_sock *rsk)
+{
+	return (struct mptcp_subflow_request_sock *)rsk;
+}
+
+enum mptcp_data_avail {
+	MPTCP_SUBFLOW_NODATA,
+	MPTCP_SUBFLOW_DATA_AVAIL,
+};
+
+struct mptcp_delegated_action {
+	struct napi_struct napi;
+	struct list_head head;
+};
+
+DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
+
+#define MPTCP_DELEGATE_SCHEDULED	0
+#define MPTCP_DELEGATE_SEND		1
+#define MPTCP_DELEGATE_ACK		2
+
+#define MPTCP_DELEGATE_ACTIONS_MASK	(~BIT(MPTCP_DELEGATE_SCHEDULED))
+/* MPTCP subflow context */
+struct mptcp_subflow_context {
+	struct	list_head node;/* conn_list of subflows */
+
+	struct_group(reset,
+
+	unsigned long avg_pacing_rate; /* protected by msk socket lock */
+	u64	local_key;
+	u64	remote_key;
+	u64	idsn;
+	u64	map_seq;
+	u32	snd_isn;
+	u32	token;
+	u32	rel_write_seq;
+	u32	map_subflow_seq;
+	u32	ssn_offset;
+	u32	map_data_len;
+	__wsum	map_data_csum;
+	u32	map_csum_len;
+	u32	request_mptcp : 1,  /* send MP_CAPABLE */
+		request_join : 1,   /* send MP_JOIN */
+		request_bkup : 1,
+		mp_capable : 1,	    /* remote is MPTCP capable */
+		mp_join : 1,	    /* remote is JOINing */
+		fully_established : 1,	    /* path validated */
+		pm_notified : 1,    /* PM hook called for established status */
+		conn_finished : 1,
+		map_valid : 1,
+		map_csum_reqd : 1,
+		map_data_fin : 1,
+		mpc_map : 1,
+		backup : 1,
+		send_mp_prio : 1,
+		send_mp_fail : 1,
+		send_fastclose : 1,
+		send_infinite_map : 1,
+		rx_eof : 1,
+		can_ack : 1,        /* only after processing the remote a key */
+		disposable : 1,	    /* ctx can be free at ulp release time */
+		stale : 1,	    /* unable to snd/rcv data, do not use for xmit */
+		local_id_valid : 1, /* local_id is correctly initialized */
+		valid_csum_seen : 1;        /* at least one csum validated */
+	enum mptcp_data_avail data_avail;
+	u32	remote_nonce;
+	u64	thmac;
+	u32	local_nonce;
+	u32	remote_token;
+	u8	hmac[MPTCPOPT_HMAC_LEN];
+	u8	local_id;
+	u8	remote_id;
+	u8	reset_seen:1;
+	u8	reset_transient:1;
+	u8	reset_reason:4;
+	u8	stale_count;
+
+	long	delegated_status;
+	unsigned long	fail_tout;
+
+	);
+
+	struct	list_head delegated_node;   /* link into delegated_action, protected by local BH */
+
+	u32	setsockopt_seq;
+	u32	stale_rcv_tstamp;
+
+	struct	sock *tcp_sock;	    /* tcp sk backpointer */
+	struct	sock *conn;	    /* parent mptcp_sock */
+	const	struct inet_connection_sock_af_ops *icsk_af_ops;
+	void	(*tcp_state_change)(struct sock *sk);
+	void	(*tcp_error_report)(struct sock *sk);
+
+	struct	rcu_head rcu;
+};
+
+static inline struct mptcp_subflow_context *
+mptcp_subflow_ctx(const struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	/* Use RCU on icsk_ulp_data only for sock diag code */
+	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
+}
+
+static inline struct sock *
+mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
+{
+	return subflow->tcp_sock;
+}
+
+static inline void
+mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
+{
+	memset(&subflow->reset, 0, sizeof(subflow->reset));
+	subflow->request_mptcp = 1;
+}
+
+static inline u64
+mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
+{
+	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
+		      subflow->ssn_offset -
+		      subflow->map_subflow_seq;
+}
+
+static inline u64
+mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
+{
+	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
+}
+
+void mptcp_subflow_process_delegated(struct sock *ssk, long actions);
+
+static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
+{
+	long old, set_bits = BIT(MPTCP_DELEGATE_SCHEDULED) | BIT(action);
+	struct mptcp_delegated_action *delegated;
+	bool schedule;
+
+	/* the caller held the subflow bh socket lock */
+	lockdep_assert_in_softirq();
+
+	/* The implied barrier pairs with tcp_release_cb_override()
+	 * mptcp_napi_poll(), and ensures the below list check sees list
+	 * updates done prior to delegated status bits changes
+	 */
+	old = set_mask_bits(&subflow->delegated_status, 0, set_bits);
+	if (!(old & BIT(MPTCP_DELEGATE_SCHEDULED))) {
+		if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node)))
+			return;
+
+		delegated = this_cpu_ptr(&mptcp_delegated_actions);
+		schedule = list_empty(&delegated->head);
+		list_add_tail(&subflow->delegated_node, &delegated->head);
+		sock_hold(mptcp_subflow_tcp_sock(subflow));
+		if (schedule)
+			napi_schedule(&delegated->napi);
+	}
+}
+
+static inline struct mptcp_subflow_context *
+mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
+{
+	struct mptcp_subflow_context *ret;
+
+	if (list_empty(&delegated->head))
+		return NULL;
+
+	ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
+	list_del_init(&ret->delegated_node);
+	return ret;
+}
+
+int mptcp_is_enabled(const struct net *net);
+unsigned int mptcp_get_add_addr_timeout(const struct net *net);
+int mptcp_is_checksum_enabled(const struct net *net);
+int mptcp_allow_join_id0(const struct net *net);
+unsigned int mptcp_stale_loss_cnt(const struct net *net);
+int mptcp_get_pm_type(const struct net *net);
+void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
+				     struct mptcp_options_received *mp_opt);
+bool __mptcp_retransmit_pending_data(struct sock *sk);
+void mptcp_check_and_set_pending(struct sock *sk);
+void __mptcp_push_pending(struct sock *sk, unsigned int flags);
+bool mptcp_subflow_data_available(struct sock *sk);
+void __init mptcp_subflow_init(void);
+void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
+void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
+		     struct mptcp_subflow_context *subflow);
+void __mptcp_subflow_send_ack(struct sock *ssk);
+void mptcp_subflow_reset(struct sock *ssk);
+void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
+void mptcp_sock_graft(struct sock *sk, struct socket *parent);
+struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
+bool __mptcp_close(struct sock *sk, long timeout);
+void mptcp_cancel_work(struct sock *sk);
+void __mptcp_unaccepted_force_close(struct sock *sk);
+
+bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
+			   const struct mptcp_addr_info *b, bool use_port);
+
+/* called with sk socket lock held */
+int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
+			    const struct mptcp_addr_info *remote);
+int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
+				struct socket **new_sock);
+void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
+			 struct sockaddr_storage *addr,
+			 unsigned short family);
+
+static inline bool __tcp_can_send(const struct sock *ssk)
+{
+	/* only send if our side has not closed yet */
+	return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
+}
+
+static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
+{
+	/* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
+	if (subflow->request_join && !subflow->fully_established)
+		return false;
+
+	return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
+}
+
+void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
+
+bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
+
+void mptcp_subflow_drop_ctx(struct sock *ssk);
+
+static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
+					      struct mptcp_subflow_context *ctx)
+{
+	sk->sk_data_ready = sock_def_readable;
+	sk->sk_state_change = ctx->tcp_state_change;
+	sk->sk_write_space = sk_stream_write_space;
+	sk->sk_error_report = ctx->tcp_error_report;
+
+	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
+}
+
+void __init mptcp_proto_init(void);
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+int __init mptcp_proto_v6_init(void);
+#endif
+
+struct sock *mptcp_sk_clone_init(const struct sock *sk,
+				 const struct mptcp_options_received *mp_opt,
+				 struct sock *ssk,
+				 struct request_sock *req);
+void mptcp_get_options(const struct sk_buff *skb,
+		       struct mptcp_options_received *mp_opt);
+
+void mptcp_finish_connect(struct sock *sk);
+void __mptcp_set_connected(struct sock *sk);
+void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout);
+
+static inline void mptcp_stop_tout_timer(struct sock *sk)
+{
+	if (!inet_csk(sk)->icsk_mtup.probe_timestamp)
+		return;
+
+	sk_stop_timer(sk, &sk->sk_timer);
+	inet_csk(sk)->icsk_mtup.probe_timestamp = 0;
+}
+
+static inline void mptcp_set_close_tout(struct sock *sk, unsigned long tout)
+{
+	/* avoid 0 timestamp, as that means no close timeout */
+	inet_csk(sk)->icsk_mtup.probe_timestamp = tout ? : 1;
+}
+
+static inline void mptcp_start_tout_timer(struct sock *sk)
+{
+	mptcp_set_close_tout(sk, tcp_jiffies32);
+	mptcp_reset_tout_timer(mptcp_sk(sk), 0);
+}
+
+static inline bool mptcp_is_fully_established(struct sock *sk)
+{
+	return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
+	       READ_ONCE(mptcp_sk(sk)->fully_established);
+}
+void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
+void mptcp_data_ready(struct sock *sk, struct sock *ssk);
+bool mptcp_finish_join(struct sock *sk);
+bool mptcp_schedule_work(struct sock *sk);
+int mptcp_setsockopt(struct sock *sk, int level, int optname,
+		     sockptr_t optval, unsigned int optlen);
+int mptcp_getsockopt(struct sock *sk, int level, int optname,
+		     char __user *optval, int __user *option);
+
+u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
+static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
+{
+	if (use_64bit)
+		return cur_seq;
+
+	return __mptcp_expand_seq(old_seq, cur_seq);
+}
+void __mptcp_check_push(struct sock *sk, struct sock *ssk);
+void __mptcp_data_acked(struct sock *sk);
+void __mptcp_error_report(struct sock *sk);
+void mptcp_subflow_eof(struct sock *sk);
+bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
+static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->snd_data_fin_enable) &&
+	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
+}
+
+static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
+{
+	if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
+		return false;
+
+	WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
+	return true;
+}
+
+static inline void mptcp_write_space(struct sock *sk)
+{
+	if (sk_stream_is_writeable(sk)) {
+		/* pairs with memory barrier in mptcp_poll */
+		smp_mb();
+		if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
+			sk_stream_write_space(sk);
+	}
+}
+
+void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
+
+#define MPTCP_TOKEN_MAX_RETRIES	4
+
+void __init mptcp_token_init(void);
+static inline void mptcp_token_init_request(struct request_sock *req)
+{
+	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
+}
+
+int mptcp_token_new_request(struct request_sock *req);
+void mptcp_token_destroy_request(struct request_sock *req);
+int mptcp_token_new_connect(struct sock *sk);
+void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
+			struct mptcp_sock *msk);
+bool mptcp_token_exists(u32 token);
+struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
+struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
+					 long *s_num);
+void mptcp_token_destroy(struct mptcp_sock *msk);
+
+void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
+
+void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
+__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
+
+void __init mptcp_pm_init(void);
+void mptcp_pm_data_init(struct mptcp_sock *msk);
+void mptcp_pm_data_reset(struct mptcp_sock *msk);
+int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
+			struct mptcp_addr_info *addr);
+int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
+			 bool require_family,
+			 struct mptcp_pm_addr_entry *entry);
+bool mptcp_pm_addr_families_match(const struct sock *sk,
+				  const struct mptcp_addr_info *loc,
+				  const struct mptcp_addr_info *rem);
+void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
+void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
+void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
+void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
+bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
+void mptcp_pm_connection_closed(struct mptcp_sock *msk);
+void mptcp_pm_subflow_established(struct mptcp_sock *msk);
+bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
+void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
+				 const struct mptcp_subflow_context *subflow);
+void mptcp_pm_add_addr_received(const struct sock *ssk,
+				const struct mptcp_addr_info *addr);
+void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
+			      const struct mptcp_addr_info *addr);
+void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
+void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
+void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
+			       const struct mptcp_rm_list *rm_list);
+void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
+void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
+int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
+				 struct mptcp_addr_info *addr,
+				 struct mptcp_addr_info *rem,
+				 u8 bkup);
+bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+			      const struct mptcp_pm_addr_entry *entry);
+void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
+bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
+struct mptcp_pm_add_entry *
+mptcp_pm_del_add_timer(struct mptcp_sock *msk,
+		       const struct mptcp_addr_info *addr, bool check_id);
+struct mptcp_pm_add_entry *
+mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
+				const struct mptcp_addr_info *addr);
+int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
+					 unsigned int id,
+					 u8 *flags, int *ifindex);
+int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
+						   unsigned int id,
+						   u8 *flags, int *ifindex);
+int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
+				 struct mptcp_pm_addr_entry *loc,
+				 struct mptcp_pm_addr_entry *rem, u8 bkup);
+int mptcp_pm_announce_addr(struct mptcp_sock *msk,
+			   const struct mptcp_addr_info *addr,
+			   bool echo);
+int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
+int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
+void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list);
+void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
+					struct list_head *rm_list);
+
+int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
+					     struct mptcp_pm_addr_entry *entry);
+void mptcp_free_local_addr_list(struct mptcp_sock *msk);
+int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);
+
+void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
+		 const struct sock *ssk, gfp_t gfp);
+void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
+void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
+bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
+
+static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.addr_signal) &
+		(BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
+}
+
+static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
+}
+
+static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
+}
+
+static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
+}
+
+static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
+}
+
+static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
+}
+
+static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
+{
+	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
+
+	if (family == AF_INET6)
+		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
+	if (!echo)
+		len += MPTCPOPT_THMAC_LEN;
+	/* account for 2 trailing 'nop' options */
+	if (port)
+		len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
+
+	return len;
+}
+
+static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
+{
+	if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
+		return -EINVAL;
+
+	return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
+}
+
+bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
+			      unsigned int opt_size, unsigned int remaining,
+			      struct mptcp_addr_info *addr, bool *echo,
+			      bool *drop_other_suboptions);
+bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
+			     struct mptcp_rm_list *rm_list);
+int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+
+void __init mptcp_pm_nl_init(void);
+void mptcp_pm_nl_work(struct mptcp_sock *msk);
+void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
+				     const struct mptcp_rm_list *rm_list);
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
+unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
+unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
+unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
+
+/* called under PM lock */
+static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
+{
+	if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
+		WRITE_ONCE(msk->pm.accept_subflow, true);
+}
+
+static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
+{
+	spin_lock_bh(&msk->pm.lock);
+	__mptcp_pm_close_subflow(msk);
+	spin_unlock_bh(&msk->pm.lock);
+}
+
+void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
+void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
+
+static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
+{
+	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
+}
+
+void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
+
+static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
+{
+	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
+}
+
+static inline bool mptcp_check_fallback(const struct sock *sk)
+{
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+
+	return __mptcp_check_fallback(msk);
+}
+
+static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
+{
+	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
+		pr_debug("TCP fallback already done (msk=%p)", msk);
+		return;
+	}
+	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
+}
+
+static inline void mptcp_do_fallback(struct sock *ssk)
+{
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+	struct sock *sk = subflow->conn;
+	struct mptcp_sock *msk;
+
+	msk = mptcp_sk(sk);
+	__mptcp_do_fallback(msk);
+	if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
+		gfp_t saved_allocation = ssk->sk_allocation;
+
+		/* we are in a atomic (BH) scope, override ssk default for data
+		 * fin allocation
+		 */
+		ssk->sk_allocation = GFP_ATOMIC;
+		ssk->sk_shutdown |= SEND_SHUTDOWN;
+		tcp_shutdown(ssk, SEND_SHUTDOWN);
+		ssk->sk_allocation = saved_allocation;
+	}
+}
+
+#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
+
+static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
+{
+	struct mptcp_ext *mpext;
+
+	mpext = skb ? mptcp_get_ext(skb) : NULL;
+	if (mpext && mpext->infinite_map)
+		return true;
+
+	return false;
+}
+
+static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
+{
+	return (subflow->request_mptcp || subflow->request_join);
+}
+
+static inline bool subflow_simultaneous_connect(struct sock *sk)
+{
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
+	return sk->sk_state == TCP_ESTABLISHED &&
+	       is_active_ssk(subflow) &&
+	       !subflow->conn_finished;
+}
+
+#ifdef CONFIG_SYN_COOKIES
+void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
+				       struct sk_buff *skb);
+bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
+					struct sk_buff *skb);
+void __init mptcp_join_cookie_init(void);
+#else
+static inline void
+subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
+				  struct sk_buff *skb) {}
+static inline bool
+mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
+				   struct sk_buff *skb)
+{
+	return false;
+}
+
+static inline void mptcp_join_cookie_init(void) {}
+#endif
+
+#endif /* __MPTCP_PROTOCOL_H */