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  +   ˆl–Ü4ý( ©³( 	Å€fàB¦-ÿÅ„yï_†I|¥+ÃÈ *ì    /* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DCCP_H
#define _LINUX_DCCP_H


#include <linux/in.h>
#include <linux/interrupt.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/uio.h>
#include <linux/workqueue.h>

#include <net/inet_connection_sock.h>
#include <net/inet_sock.h>
#include <net/inet_timewait_sock.h>
#include <net/tcp_states.h>
#include <uapi/linux/dccp.h>

enum dccp_state {
	DCCP_OPEN	     = TCP_ESTABLISHED,
	DCCP_REQUESTING	     = TCP_SYN_SENT,
	DCCP_LISTEN	     = TCP_LISTEN,
	DCCP_RESPOND	     = TCP_SYN_RECV,
	/*
	 * States involved in closing a DCCP connection:
	 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
	 *
	 * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
	 *  a. Client has performed active-close, has sent a Close to the server
	 *     from state OPEN or PARTOPEN, and is waiting for the final Reset
	 *     (in this case, SOCK_DONE == 1).
	 *  b. Client is asked to perform passive-close, by receiving a CloseReq
	 *     in (PART)OPEN state. It sends a Close and waits for final Reset
	 *     (in this case, SOCK_DONE == 0).
	 *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
	 *
	 * 3) The following intermediate states are employed to give passively
	 *    closing nodes a chance to process their unread data:
	 *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
	 *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
	 */
	DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
	DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,	/* any node receiving a Close */
	DCCP_CLOSING	     = TCP_CLOSING,
	DCCP_TIME_WAIT	     = TCP_TIME_WAIT,
	DCCP_CLOSED	     = TCP_CLOSE,
	DCCP_NEW_SYN_RECV    = TCP_NEW_SYN_RECV,
	DCCP_PARTOPEN	     = TCP_MAX_STATES,
	DCCP_PASSIVE_CLOSEREQ,			/* clients receiving CloseReq */
	DCCP_MAX_STATES
};

enum {
	DCCPF_OPEN	      = TCPF_ESTABLISHED,
	DCCPF_REQUESTING      = TCPF_SYN_SENT,
	DCCPF_LISTEN	      = TCPF_LISTEN,
	DCCPF_RESPOND	      = TCPF_SYN_RECV,
	DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
	DCCPF_CLOSING	      = TCPF_CLOSING,
	DCCPF_TIME_WAIT	      = TCPF_TIME_WAIT,
	DCCPF_CLOSED	      = TCPF_CLOSE,
	DCCPF_NEW_SYN_RECV    = TCPF_NEW_SYN_RECV,
	DCCPF_PARTOPEN	      = (1 << DCCP_PARTOPEN),
};

static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
{
	return (struct dccp_hdr *)skb_transport_header(skb);
}

static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
{
	skb_push(skb, headlen);
	skb_reset_transport_header(skb);
	return memset(skb_transport_header(skb), 0, headlen);
}

static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
{
	return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
}

static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
{
	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
}

static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
{
	const struct dccp_hdr *dh = dccp_hdr(skb);
	return __dccp_basic_hdr_len(dh);
}

static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
{
	__u64 seq_nr =  ntohs(dh->dccph_seq);

	if (dh->dccph_x != 0)
		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
	else
		seq_nr += (u32)dh->dccph_seq2 << 16;

	return seq_nr;
}

static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
{
	return (struct dccp_hdr_request *)(skb_transport_header(skb) +
					   dccp_basic_hdr_len(skb));
}

static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
{
	return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
					    dccp_basic_hdr_len(skb));
}

static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
{
	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
	return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
}

static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
{
	return (struct dccp_hdr_response *)(skb_transport_header(skb