include/linux/dccp.h - kernel/msm-4.9 - Gitiles

 #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) +
 					    dccp_basic_hdr_len(skb));
 }

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

 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
 {
 	return __dccp_basic_hdr_len(dh) +
 	       dccp_packet_hdr_len(dh->dccph_type);
 }

 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 {
 	return __dccp_hdr_len(dccp_hdr(skb));
 }

 /**
  * struct dccp_request_sock  -  represent DCCP-specific connection request
  * @dreq_inet_rsk: structure inherited from
  * @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1)
  * @dreq_gss: greatest sequence number sent (for retransmitted Responses)
  * @dreq_isr: initial sequence number received in the first Request
  * @dreq_gsr: greatest sequence number received (for retransmitted Request(s))
  * @dreq_service: service code present on the Request (there is just one)
  * @dreq_featneg: feature negotiation options for this connection
  * The following two fields are analogous to the ones in dccp_sock:
  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
  */
 struct dccp_request_sock {
 	struct inet_request_sock dreq_inet_rsk;
 	__u64			 dreq_iss;
 	__u64			 dreq_gss;
 	__u64			 dreq_isr;
 	__u64			 dreq_gsr;
 	__be32			 dreq_service;
 	struct list_head	 dreq_featneg;
 	__u32			 dreq_timestamp_echo;
 	__u32			 dreq_timestamp_time;
 };

 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
 {
 	return (struct dccp_request_sock *)req;
 }

 extern struct inet_timewait_death_row dccp_death_row;

 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
 			      struct sk_buff *skb);

 struct dccp_options_received {
 	u64	dccpor_ndp:48;
 	u32	dccpor_timestamp;
 	u32	dccpor_timestamp_echo;
 	u32	dccpor_elapsed_time;
 };

 struct ccid;

 enum dccp_role {
 	DCCP_ROLE_UNDEFINED,
 	DCCP_ROLE_LISTEN,
 	DCCP_ROLE_CLIENT,
 	DCCP_ROLE_SERVER,
 };

 struct dccp_service_list {
 	__u32	dccpsl_nr;
 	__be32	dccpsl_list[0];
 };

 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
 #define DCCP_SERVICE_CODE_IS_ABSENT		0

 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
 					const __be32 service)
 {
 	if (likely(sl != NULL)) {
 		u32 i = sl->dccpsl_nr;
 		while (i--)
 			if (sl->dccpsl_list[i] == service)
 				return 1;
 	}
 	return 0;
 }

 struct dccp_ackvec;

 /**
  * struct dccp_sock - DCCP socket state
  *
  * @dccps_swl - sequence number window low
  * @dccps_swh - sequence number window high
  * @dccps_awl - acknowledgement number window low
  * @dccps_awh - acknowledgement number window high
  * @dccps_iss - initial sequence number sent
  * @dccps_isr - initial sequence number received
  * @dccps_osr - first OPEN sequence number received
  * @dccps_gss - greatest sequence number sent
  * @dccps_gsr - greatest valid sequence number received
  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
  * @dccps_service - first (passive sock) or unique (active sock) service code
  * @dccps_service_list - second .. last service code on passive socket
  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
  * @dccps_l_ack_ratio - feature-local Ack Ratio
  * @dccps_r_ack_ratio - feature-remote Ack Ratio
  * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
  * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
  * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
  * @dccps_ndp_count - number of Non Data Packets since last data packet
  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
  * @dccps_hc_rx_ackvec - rx half connection ack vector
  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
  * @dccps_options_received - parsed set of retrieved options
  * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
  * @dccps_tx_qlen - maximum length of the TX queue
  * @dccps_role - role of this sock, one of %dccp_role
  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
  * @dccps_hc_tx_insert_options - sender wants to add options when sending
  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
  * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
  * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
  * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
  */
 struct dccp_sock {
 	/* inet_connection_sock has to be the first member of dccp_sock */
 	struct inet_connection_sock	dccps_inet_connection;
 #define dccps_syn_rtt			dccps_inet_connection.icsk_ack.lrcvtime
 	__u64				dccps_swl;
 	__u64				dccps_swh;
 	__u64				dccps_awl;
 	__u64				dccps_awh;
 	__u64				dccps_iss;
 	__u64				dccps_isr;
 	__u64				dccps_osr;
 	__u64				dccps_gss;
 	__u64				dccps_gsr;
 	__u64				dccps_gar;
 	__be32				dccps_service;
 	__u32				dccps_mss_cache;
 	struct dccp_service_list	*dccps_service_list;
 	__u32				dccps_timestamp_echo;
 	__u32				dccps_timestamp_time;
 	__u16				dccps_l_ack_ratio;
 	__u16				dccps_r_ack_ratio;
 	__u64				dccps_l_seq_win:48;
 	__u64				dccps_r_seq_win:48;
 	__u8				dccps_pcslen:4;
 	__u8				dccps_pcrlen:4;
 	__u8				dccps_send_ndp_count:1;
 	__u64				dccps_ndp_count:48;
 	unsigned long			dccps_rate_last;
 	struct list_head		dccps_featneg;
 	struct dccp_ackvec		*dccps_hc_rx_ackvec;
 	struct ccid			*dccps_hc_rx_ccid;
 	struct ccid			*dccps_hc_tx_ccid;
 	struct dccp_options_received	dccps_options_received;
 	__u8				dccps_qpolicy;
 	__u32				dccps_tx_qlen;
 	enum dccp_role			dccps_role:2;
 	__u8				dccps_hc_rx_insert_options:1;
 	__u8				dccps_hc_tx_insert_options:1;
 	__u8				dccps_server_timewait:1;
 	__u8				dccps_sync_scheduled:1;
 	struct tasklet_struct		dccps_xmitlet;
 	struct timer_list		dccps_xmit_timer;
 };

 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
 {
 	return (struct dccp_sock *)sk;
 }

 static inline const char *dccp_role(const struct sock *sk)
 {
 	switch (dccp_sk(sk)->dccps_role) {
 	case DCCP_ROLE_UNDEFINED: return "undefined";
 	case DCCP_ROLE_LISTEN:	  return "listen";
 	case DCCP_ROLE_SERVER:	  return "server";
 	case DCCP_ROLE_CLIENT:	  return "client";
 	}
 	return NULL;
 }

 extern void dccp_syn_ack_timeout(const struct request_sock *req);

 #endif /* _LINUX_DCCP_H */
	#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) +
	dccp_basic_hdr_len(skb));
	}

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

	static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
	{
	return __dccp_basic_hdr_len(dh) +
	dccp_packet_hdr_len(dh->dccph_type);
	}

	static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
	{
	return __dccp_hdr_len(dccp_hdr(skb));
	}

	/**
	* struct dccp_request_sock - represent DCCP-specific connection request
	* @dreq_inet_rsk: structure inherited from
	* @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1)
	* @dreq_gss: greatest sequence number sent (for retransmitted Responses)
	* @dreq_isr: initial sequence number received in the first Request
	* @dreq_gsr: greatest sequence number received (for retransmitted Request(s))
	* @dreq_service: service code present on the Request (there is just one)
	* @dreq_featneg: feature negotiation options for this connection
	* The following two fields are analogous to the ones in dccp_sock:
	* @dreq_timestamp_echo: last received timestamp to echo (13.1)
	* @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
	*/
	struct dccp_request_sock {
	struct inet_request_sock dreq_inet_rsk;
	__u64 dreq_iss;
	__u64 dreq_gss;
	__u64 dreq_isr;
	__u64 dreq_gsr;
	__be32 dreq_service;
	struct list_head dreq_featneg;
	__u32 dreq_timestamp_echo;
	__u32 dreq_timestamp_time;
	};

	static inline struct dccp_request_sock dccp_rsk(const struct request_sock req)
	{
	return (struct dccp_request_sock *)req;
	}

	extern struct inet_timewait_death_row dccp_death_row;

	extern int dccp_parse_options(struct sock sk, struct dccp_request_sock dreq,
	struct sk_buff *skb);

	struct dccp_options_received {
	u64 dccpor_ndp:48;
	u32 dccpor_timestamp;
	u32 dccpor_timestamp_echo;
	u32 dccpor_elapsed_time;
	};

	struct ccid;

	enum dccp_role {
	DCCP_ROLE_UNDEFINED,
	DCCP_ROLE_LISTEN,
	DCCP_ROLE_CLIENT,
	DCCP_ROLE_SERVER,
	};

	struct dccp_service_list {
	__u32 dccpsl_nr;
	__be32 dccpsl_list[0];
	};

	#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
	#define DCCP_SERVICE_CODE_IS_ABSENT 0

	static inline int dccp_list_has_service(const struct dccp_service_list *sl,
	const __be32 service)
	{
	if (likely(sl != NULL)) {
	u32 i = sl->dccpsl_nr;
	while (i--)
	if (sl->dccpsl_list[i] == service)
	return 1;
	}
	return 0;
	}

	struct dccp_ackvec;

	/**
	* struct dccp_sock - DCCP socket state
	*
	* @dccps_swl - sequence number window low
	* @dccps_swh - sequence number window high
	* @dccps_awl - acknowledgement number window low
	* @dccps_awh - acknowledgement number window high
	* @dccps_iss - initial sequence number sent
	* @dccps_isr - initial sequence number received
	* @dccps_osr - first OPEN sequence number received
	* @dccps_gss - greatest sequence number sent
	* @dccps_gsr - greatest valid sequence number received
	* @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
	* @dccps_service - first (passive sock) or unique (active sock) service code
	* @dccps_service_list - second .. last service code on passive socket
	* @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
	* @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
	* @dccps_l_ack_ratio - feature-local Ack Ratio
	* @dccps_r_ack_ratio - feature-remote Ack Ratio
	* @dccps_l_seq_win - local Sequence Window (influences ack number validity)
	* @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
	* @dccps_pcslen - sender partial checksum coverage (via sockopt)
	* @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
	* @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
	* @dccps_ndp_count - number of Non Data Packets since last data packet
	* @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
	* @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
	* @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
	* @dccps_hc_rx_ackvec - rx half connection ack vector
	* @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
	* @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
	* @dccps_options_received - parsed set of retrieved options
	* @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
	* @dccps_tx_qlen - maximum length of the TX queue
	* @dccps_role - role of this sock, one of %dccp_role
	* @dccps_hc_rx_insert_options - receiver wants to add options when acking
	* @dccps_hc_tx_insert_options - sender wants to add options when sending
	* @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
	* @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
	* @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
	* @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
	* @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
	*/
	struct dccp_sock {
	/* inet_connection_sock has to be the first member of dccp_sock */
	struct inet_connection_sock dccps_inet_connection;
	#define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime
	__u64 dccps_swl;
	__u64 dccps_swh;
	__u64 dccps_awl;
	__u64 dccps_awh;
	__u64 dccps_iss;
	__u64 dccps_isr;
	__u64 dccps_osr;
	__u64 dccps_gss;
	__u64 dccps_gsr;
	__u64 dccps_gar;
	__be32 dccps_service;
	__u32 dccps_mss_cache;
	struct dccp_service_list *dccps_service_list;
	__u32 dccps_timestamp_echo;
	__u32 dccps_timestamp_time;
	__u16 dccps_l_ack_ratio;
	__u16 dccps_r_ack_ratio;
	__u64 dccps_l_seq_win:48;
	__u64 dccps_r_seq_win:48;
	__u8 dccps_pcslen:4;
	__u8 dccps_pcrlen:4;
	__u8 dccps_send_ndp_count:1;
	__u64 dccps_ndp_count:48;
	unsigned long dccps_rate_last;
	struct list_head dccps_featneg;
	struct dccp_ackvec *dccps_hc_rx_ackvec;
	struct ccid *dccps_hc_rx_ccid;
	struct ccid *dccps_hc_tx_ccid;
	struct dccp_options_received dccps_options_received;
	__u8 dccps_qpolicy;
	__u32 dccps_tx_qlen;
	enum dccp_role dccps_role:2;
	__u8 dccps_hc_rx_insert_options:1;
	__u8 dccps_hc_tx_insert_options:1;
	__u8 dccps_server_timewait:1;
	__u8 dccps_sync_scheduled:1;
	struct tasklet_struct dccps_xmitlet;
	struct timer_list dccps_xmit_timer;
	};

	static inline struct dccp_sock dccp_sk(const struct sock sk)
	{
	return (struct dccp_sock *)sk;
	}

	static inline const char dccp_role(const struct sock sk)
	{
	switch (dccp_sk(sk)->dccps_role) {
	case DCCP_ROLE_UNDEFINED: return "undefined";
	case DCCP_ROLE_LISTEN: return "listen";
	case DCCP_ROLE_SERVER: return "server";
	case DCCP_ROLE_CLIENT: return "client";
	}
	return NULL;
	}

	extern void dccp_syn_ack_timeout(const struct request_sock *req);

	#endif /* _LINUX_DCCP_H */