net/dccp/dccp.h - kernel/msm-5.4 - Gitiles

 #ifndef _DCCP_H
 #define _DCCP_H
 /*
  *  net/dccp/dccp.h
  *
  *  An implementation of the DCCP protocol
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
  *
  *	This program is free software; you can redistribute it and/or modify it
  *	under the terms of the GNU General Public License version 2 as
  *	published by the Free Software Foundation.
  */

 #include <linux/config.h>
 #include <linux/dccp.h>
 #include <net/snmp.h>
 #include <net/sock.h>
 #include <net/tcp.h>

 #ifdef CONFIG_IP_DCCP_DEBUG
 extern int dccp_debug;

 #define dccp_pr_debug(format, a...) \
 	do { if (dccp_debug) \
 		printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
 	} while (0)
 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
 					     printk(format, ##a); } while (0)
 #else
 #define dccp_pr_debug(format, a...)
 #define dccp_pr_debug_cat(format, a...)
 #endif

 extern struct inet_hashinfo dccp_hashinfo;

 extern atomic_t dccp_orphan_count;
 extern int dccp_tw_count;
 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);

 extern void dccp_time_wait(struct sock *sk, int state, int timeo);

 /* FIXME: Right size this */
 #define DCCP_MAX_OPT_LEN 128

 #define DCCP_MAX_PACKET_HDR 32

 #define MAX_DCCP_HEADER  (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)

 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
 				     * state, about 60 seconds */

 /* draft-ietf-dccp-spec-11.txt initial RTO value */
 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))

 /* Maximal interval between probes for local resources.  */
 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))

 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */

 extern struct proto dccp_v4_prot;

 /* is seq1 < seq2 ? */
 static inline int before48(const u64 seq1, const u64 seq2)
 {
 	return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
 }

 /* is seq1 > seq2 ? */
 static inline int after48(const u64 seq1, const u64 seq2)
 {
 	return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
 }

 /* is seq2 <= seq1 <= seq3 ? */
 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
 {
 	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
 }

 static inline u64 max48(const u64 seq1, const u64 seq2)
 {
 	return after48(seq1, seq2) ? seq1 : seq2;
 }

 enum {
 	DCCP_MIB_NUM = 0,
 	DCCP_MIB_ACTIVEOPENS,			/* ActiveOpens */
 	DCCP_MIB_ESTABRESETS,			/* EstabResets */
 	DCCP_MIB_CURRESTAB,			/* CurrEstab */
 	DCCP_MIB_OUTSEGS,			/* OutSegs */
 	DCCP_MIB_OUTRSTS,
 	DCCP_MIB_ABORTONTIMEOUT,
 	DCCP_MIB_TIMEOUTS,
 	DCCP_MIB_ABORTFAILED,
 	DCCP_MIB_PASSIVEOPENS,
 	DCCP_MIB_ATTEMPTFAILS,
 	DCCP_MIB_OUTDATAGRAMS,
 	DCCP_MIB_INERRS,
 	DCCP_MIB_OPTMANDATORYERROR,
 	DCCP_MIB_INVALIDOPT,
 	__DCCP_MIB_MAX
 };

 #define DCCP_MIB_MAX	__DCCP_MIB_MAX
 struct dccp_mib {
 	unsigned long	mibs[DCCP_MIB_MAX];
 } __SNMP_MIB_ALIGN__;

 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 #define DCCP_INC_STATS(field)	    SNMP_INC_STATS(dccp_statistics, field)
 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 #define DCCP_DEC_STATS(field)	    SNMP_DEC_STATS(dccp_statistics, field)
 #define DCCP_ADD_STATS_BH(field, val) \
 			SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 #define DCCP_ADD_STATS_USER(field, val)	\
 			SNMP_ADD_STATS_USER(dccp_statistics, field, val)

 extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);

 extern int dccp_send_response(struct sock *sk);
 extern void dccp_send_ack(struct sock *sk);
 extern void dccp_send_delayed_ack(struct sock *sk);
 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 			   const enum dccp_pkt_type pkt_type);

 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo);
 extern void dccp_write_space(struct sock *sk);

 extern void dccp_init_xmit_timers(struct sock *sk);
 static inline void dccp_clear_xmit_timers(struct sock *sk)
 {
 	inet_csk_clear_xmit_timers(sk);
 }

 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);

 extern const char *dccp_packet_name(const int type);
 extern const char *dccp_state_name(const int state);

 static inline void dccp_set_state(struct sock *sk, const int state)
 {
 	const int oldstate = sk->sk_state;

 	dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
 		      dccp_role(sk), sk,
 		      dccp_state_name(oldstate), dccp_state_name(state));
 	WARN_ON(state == oldstate);

 	switch (state) {
 	case DCCP_OPEN:
 		if (oldstate != DCCP_OPEN)
 			DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
 		break;

 	case DCCP_CLOSED:
 		if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
 			DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);

 		sk->sk_prot->unhash(sk);
 		if (inet_csk(sk)->icsk_bind_hash != NULL &&
 		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 			inet_put_port(&dccp_hashinfo, sk);
 		/* fall through */
 	default:
 		if (oldstate == DCCP_OPEN)
 			DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
 	}

 	/* Change state AFTER socket is unhashed to avoid closed
 	 * socket sitting in hash tables.
 	 */
 	sk->sk_state = state;
 }

 static inline void dccp_done(struct sock *sk)
 {
 	dccp_set_state(sk, DCCP_CLOSED);
 	dccp_clear_xmit_timers(sk);

 	sk->sk_shutdown = SHUTDOWN_MASK;

 	if (!sock_flag(sk, SOCK_DEAD))
 		sk->sk_state_change(sk);
 	else
 		inet_csk_destroy_sock(sk);
 }

 static inline void dccp_openreq_init(struct request_sock *req,
 				     struct dccp_sock *dp,
 				     struct sk_buff *skb)
 {
 	/*
 	 * FIXME: fill in the other req fields from the DCCP options
 	 * received
 	 */
 	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 	inet_rsk(req)->acked	= 0;
 	req->rcv_wnd = 0;
 }

 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);

 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 					      const struct request_sock *req,
 					      const struct sk_buff *skb);

 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);

 extern void dccp_v4_err(struct sk_buff *skb, u32);

 extern int dccp_v4_rcv(struct sk_buff *skb);

 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 					      struct sk_buff *skb,
 					      struct request_sock *req,
 					      struct dst_entry *dst);
 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 				   struct request_sock *req,
 				   struct request_sock **prev);

 extern int dccp_child_process(struct sock *parent, struct sock *child,
 			      struct sk_buff *skb);
 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 				  struct dccp_hdr *dh, unsigned len);
 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 				const struct dccp_hdr *dh, const unsigned len);

 extern void		dccp_close(struct sock *sk, long timeout);
 extern struct sk_buff	*dccp_make_response(struct sock *sk,
 					    struct dst_entry *dst,
 					    struct request_sock *req);
 extern struct sk_buff	*dccp_make_reset(struct sock *sk,
 					 struct dst_entry *dst,
 					 enum dccp_reset_codes code);

 extern int	   dccp_connect(struct sock *sk);
 extern int	   dccp_disconnect(struct sock *sk, int flags);
 extern int	   dccp_getsockopt(struct sock *sk, int level, int optname,
 				   char __user *optval, int __user *optlen);
 extern int	   dccp_setsockopt(struct sock *sk, int level, int optname,
 				   char __user *optval, int optlen);
 extern int	   dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 extern int	   dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 				struct msghdr *msg, size_t size);
 extern int	   dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 				struct msghdr *msg, size_t len, int nonblock,
 				int flags, int *addr_len);
 extern void	   dccp_shutdown(struct sock *sk, int how);

 extern int	   dccp_v4_checksum(const struct sk_buff *skb,
 				    const u32 saddr, const u32 daddr);

 extern int	   dccp_v4_send_reset(struct sock *sk,
 				      enum dccp_reset_codes code);
 extern void	   dccp_send_close(struct sock *sk, const int active);

 struct dccp_skb_cb {
 	__u8 dccpd_type;
 	__u8 dccpd_reset_code;
 	__u8 dccpd_service;
 	__u8 dccpd_ccval;
 	__u64 dccpd_seq;
 	__u64 dccpd_ack_seq;
 	int  dccpd_opt_len;
 };

 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))

 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 {
 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

 	return type == DCCP_PKT_ACK	 ||
 	       type == DCCP_PKT_CLOSE	 ||
 	       type == DCCP_PKT_CLOSEREQ ||
 	       type == DCCP_PKT_RESET	 ||
 	       type == DCCP_PKT_SYNC	 ||
 	       type == DCCP_PKT_SYNCACK;
 }

 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 {
 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

 	return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 }

 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)

 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 {
 	if (value > DCCP_MAX_SEQNO)
 		value -= DCCP_MAX_SEQNO + 1;
 	*seqno = value;
 }

 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 {
 	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 }

 static inline void dccp_inc_seqno(u64 *seqno)
 {
 	if (++*seqno > DCCP_MAX_SEQNO)
 		*seqno = 0;
 }

 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 {
 	struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 							   sizeof(*dh));

 #if defined(__LITTLE_ENDIAN_BITFIELD)
 	dh->dccph_seq	   = htonl((gss >> 32)) >> 8;
 #elif defined(__BIG_ENDIAN_BITFIELD)
 	dh->dccph_seq	   = htonl((gss >> 32));
 #else
 #error  "Adjust your <asm/byteorder.h> defines"
 #endif
 	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 }

 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 				    const u64 gsr)
 {
 #if defined(__LITTLE_ENDIAN_BITFIELD)
 	dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
 #elif defined(__BIG_ENDIAN_BITFIELD)
 	dhack->dccph_ack_nr_high = htonl((gsr >> 32));
 #else
 #error  "Adjust your <asm/byteorder.h> defines"
 #endif
 	dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 }

 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 {
 	struct dccp_sock *dp = dccp_sk(sk);

 	dp->dccps_gsr = seq;
 	dccp_set_seqno(&dp->dccps_swl,
 		       (dp->dccps_gsr + 1 -
 		        (dp->dccps_options.dccpo_sequence_window / 4)));
 	dccp_set_seqno(&dp->dccps_swh,
 		       (dp->dccps_gsr +
 			(3 * dp->dccps_options.dccpo_sequence_window) / 4));
 }

 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 {
 	struct dccp_sock *dp = dccp_sk(sk);

 	dp->dccps_awh = dp->dccps_gss = seq;
 	dccp_set_seqno(&dp->dccps_awl,
 		       (dp->dccps_gss -
 			dp->dccps_options.dccpo_sequence_window + 1));
 }

 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 extern void dccp_insert_option_elapsed_time(struct sock *sk,
 					    struct sk_buff *skb,
 					    u32 elapsed_time);
 extern void dccp_insert_option_timestamp(struct sock *sk,
 					 struct sk_buff *skb);
 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 			       unsigned char option,
 			       const void *value, unsigned char len);

 extern struct socket *dccp_ctl_socket;

 #define DCCP_ACKPKTS_STATE_RECEIVED	0
 #define DCCP_ACKPKTS_STATE_ECN_MARKED	(1 << 6)
 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED	(3 << 6)

 #define DCCP_ACKPKTS_STATE_MASK		0xC0 /* 11000000 */
 #define DCCP_ACKPKTS_LEN_MASK		0x3F /* 00111111 */

 /** struct dccp_ackpkts - acknowledgeable packets
  *
  * This data structure is the one defined in the DCCP draft
  * Appendix A.
  *
  * @dccpap_buf_head - circular buffer head
  * @dccpap_buf_tail - circular buffer tail
  * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
  * 		       buffer (i.e. %dccpap_buf_head)
  * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
  * 		       by the buffer with State 0
  *
  * Additionally, the HC-Receiver must keep some information about the
  * Ack Vectors it has recently sent. For each packet sent carrying an
  * Ack Vector, it remembers four variables:
  *
  * @dccpap_ack_seqno - the Sequence Number used for the packet
  * 		       (HC-Receiver seqno)
  * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
  * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
  * 		       (HC-Sender seqno)
  * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
  *
  * @dccpap_buf_len - circular buffer length
  * @dccpap_time		- the time in usecs
  * @dccpap_buf - circular buffer of acknowledgeable packets
  */
 struct dccp_ackpkts {
 	unsigned int		dccpap_buf_head;
 	unsigned int		dccpap_buf_tail;
 	u64			dccpap_buf_ackno;
 	u64			dccpap_ack_seqno;
 	u64			dccpap_ack_ackno;
 	unsigned int		dccpap_ack_ptr;
 	unsigned int		dccpap_buf_vector_len;
 	unsigned int		dccpap_ack_vector_len;
 	unsigned int		dccpap_buf_len;
 	struct timeval		dccpap_time;
 	u8			dccpap_buf_nonce;
 	u8			dccpap_ack_nonce;
 	u8			dccpap_buf[0];
 };

 extern struct dccp_ackpkts *
 		dccp_ackpkts_alloc(unsigned int len,
 				  const unsigned int __nocast priority);
 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
 extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
 			    u64 ackno, u8 state);
 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
 					 struct sock *sk, u64 ackno);

 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);

 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 {
 	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 }

 static inline suseconds_t timeval_delta(const struct timeval *large,
 					const struct timeval *small)
 {
 	time_t	    secs  = large->tv_sec  - small->tv_sec;
 	suseconds_t usecs = large->tv_usec - small->tv_usec;

 	if (usecs < 0) {
 		secs--;
 		usecs += USEC_PER_SEC;
 	}
 	return secs * USEC_PER_SEC + usecs;
 }

 static inline void timeval_add_usecs(struct timeval *tv,
 				     const suseconds_t usecs)
 {
 	tv->tv_usec += usecs;
 	while (tv->tv_usec >= USEC_PER_SEC) {
 		tv->tv_sec++;
 		tv->tv_usec -= USEC_PER_SEC;
 	}
 }

 static inline void timeval_sub_usecs(struct timeval *tv,
 				     const suseconds_t usecs)
 {
 	tv->tv_usec -= usecs;
 	while (tv->tv_usec < 0) {
 		tv->tv_sec--;
 		tv->tv_usec += USEC_PER_SEC;
 	}
 }

 #ifdef CONFIG_IP_DCCP_DEBUG
 extern void dccp_ackvector_print(const u64 ackno,
 				 const unsigned char *vector, int len);
 extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
 #else
 static inline void dccp_ackvector_print(const u64 ackno,
 					const unsigned char *vector,
 					int len) { }
 static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
 #endif

 #endif /* _DCCP_H */
	#ifndef _DCCP_H
	#define _DCCP_H
	/*
	* net/dccp/dccp.h
	*
	* An implementation of the DCCP protocol
	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
	* Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/config.h>
	#include <linux/dccp.h>
	#include <net/snmp.h>
	#include <net/sock.h>
	#include <net/tcp.h>

	#ifdef CONFIG_IP_DCCP_DEBUG
	extern int dccp_debug;

	#define dccp_pr_debug(format, a...) \
	do { if (dccp_debug) \
	printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
	} while (0)
	#define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
	printk(format, ##a); } while (0)
	#else
	#define dccp_pr_debug(format, a...)
	#define dccp_pr_debug_cat(format, a...)
	#endif

	extern struct inet_hashinfo dccp_hashinfo;

	extern atomic_t dccp_orphan_count;
	extern int dccp_tw_count;
	extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);

	extern void dccp_time_wait(struct sock *sk, int state, int timeo);

	/* FIXME: Right size this */
	#define DCCP_MAX_OPT_LEN 128

	#define DCCP_MAX_PACKET_HDR 32

	#define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)

	#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
	* state, about 60 seconds */

	/* draft-ietf-dccp-spec-11.txt initial RTO value */
	#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))

	/* Maximal interval between probes for local resources. */
	#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))

	#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */

	extern struct proto dccp_v4_prot;

	/* is seq1 < seq2 ? */
	static inline int before48(const u64 seq1, const u64 seq2)
	{
	return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
	}

	/* is seq1 > seq2 ? */
	static inline int after48(const u64 seq1, const u64 seq2)
	{
	return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
	}

	/* is seq2 <= seq1 <= seq3 ? */
	static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
	{
	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
	}

	static inline u64 max48(const u64 seq1, const u64 seq2)
	{
	return after48(seq1, seq2) ? seq1 : seq2;
	}

	enum {
	DCCP_MIB_NUM = 0,
	DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
	DCCP_MIB_ESTABRESETS, /* EstabResets */
	DCCP_MIB_CURRESTAB, /* CurrEstab */
	DCCP_MIB_OUTSEGS, /* OutSegs */
	DCCP_MIB_OUTRSTS,
	DCCP_MIB_ABORTONTIMEOUT,
	DCCP_MIB_TIMEOUTS,
	DCCP_MIB_ABORTFAILED,
	DCCP_MIB_PASSIVEOPENS,
	DCCP_MIB_ATTEMPTFAILS,
	DCCP_MIB_OUTDATAGRAMS,
	DCCP_MIB_INERRS,
	DCCP_MIB_OPTMANDATORYERROR,
	DCCP_MIB_INVALIDOPT,
	__DCCP_MIB_MAX
	};

	#define DCCP_MIB_MAX __DCCP_MIB_MAX
	struct dccp_mib {
	unsigned long mibs[DCCP_MIB_MAX];
	} __SNMP_MIB_ALIGN__;

	DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
	#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
	#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
	#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
	#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
	#define DCCP_ADD_STATS_BH(field, val) \
	SNMP_ADD_STATS_BH(dccp_statistics, field, val)
	#define DCCP_ADD_STATS_USER(field, val) \
	SNMP_ADD_STATS_USER(dccp_statistics, field, val)

	extern int dccp_transmit_skb(struct sock sk, struct sk_buff skb);
	extern int dccp_retransmit_skb(struct sock sk, struct sk_buff skb);

	extern int dccp_send_response(struct sock *sk);
	extern void dccp_send_ack(struct sock *sk);
	extern void dccp_send_delayed_ack(struct sock *sk);
	extern void dccp_send_sync(struct sock *sk, const u64 seq,
	const enum dccp_pkt_type pkt_type);

	extern int dccp_write_xmit(struct sock sk, struct sk_buff skb, long *timeo);
	extern void dccp_write_space(struct sock *sk);

	extern void dccp_init_xmit_timers(struct sock *sk);
	static inline void dccp_clear_xmit_timers(struct sock *sk)
	{
	inet_csk_clear_xmit_timers(sk);
	}

	extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);

	extern const char *dccp_packet_name(const int type);
	extern const char *dccp_state_name(const int state);

	static inline void dccp_set_state(struct sock *sk, const int state)
	{
	const int oldstate = sk->sk_state;

	dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
	dccp_role(sk), sk,
	dccp_state_name(oldstate), dccp_state_name(state));
	WARN_ON(state == oldstate);

	switch (state) {
	case DCCP_OPEN:
	if (oldstate != DCCP_OPEN)
	DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
	break;

	case DCCP_CLOSED:
	if (oldstate == DCCP_CLOSING \|\| oldstate == DCCP_OPEN)
	DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);

	sk->sk_prot->unhash(sk);
	if (inet_csk(sk)->icsk_bind_hash != NULL &&
	!(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
	inet_put_port(&dccp_hashinfo, sk);
	/* fall through */
	default:
	if (oldstate == DCCP_OPEN)
	DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
	}

	/* Change state AFTER socket is unhashed to avoid closed
	* socket sitting in hash tables.
	*/
	sk->sk_state = state;
	}

	static inline void dccp_done(struct sock *sk)
	{
	dccp_set_state(sk, DCCP_CLOSED);
	dccp_clear_xmit_timers(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (!sock_flag(sk, SOCK_DEAD))
	sk->sk_state_change(sk);
	else
	inet_csk_destroy_sock(sk);
	}

	static inline void dccp_openreq_init(struct request_sock *req,
	struct dccp_sock *dp,
	struct sk_buff *skb)
	{
	/*
	* FIXME: fill in the other req fields from the DCCP options
	* received
	*/
	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
	inet_rsk(req)->acked = 0;
	req->rcv_wnd = 0;
	}

	extern int dccp_v4_conn_request(struct sock sk, struct sk_buff skb);

	extern struct sock dccp_create_openreq_child(struct sock sk,
	const struct request_sock *req,
	const struct sk_buff *skb);

	extern int dccp_v4_do_rcv(struct sock sk, struct sk_buff skb);

	extern void dccp_v4_err(struct sk_buff *skb, u32);

	extern int dccp_v4_rcv(struct sk_buff *skb);

	extern struct sock dccp_v4_request_recv_sock(struct sock sk,
	struct sk_buff *skb,
	struct request_sock *req,
	struct dst_entry *dst);
	extern struct sock dccp_check_req(struct sock sk, struct sk_buff *skb,
	struct request_sock *req,
	struct request_sock **prev);

	extern int dccp_child_process(struct sock parent, struct sock child,
	struct sk_buff *skb);
	extern int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
	struct dccp_hdr *dh, unsigned len);
	extern int dccp_rcv_established(struct sock sk, struct sk_buff skb,
	const struct dccp_hdr *dh, const unsigned len);

	extern void dccp_close(struct sock *sk, long timeout);
	extern struct sk_buff dccp_make_response(struct sock sk,
	struct dst_entry *dst,
	struct request_sock *req);
	extern struct sk_buff dccp_make_reset(struct sock sk,
	struct dst_entry *dst,
	enum dccp_reset_codes code);

	extern int dccp_connect(struct sock *sk);
	extern int dccp_disconnect(struct sock *sk, int flags);
	extern int dccp_getsockopt(struct sock *sk, int level, int optname,
	char __user optval, int __user optlen);
	extern int dccp_setsockopt(struct sock *sk, int level, int optname,
	char __user *optval, int optlen);
	extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
	extern int dccp_sendmsg(struct kiocb iocb, struct sock sk,
	struct msghdr *msg, size_t size);
	extern int dccp_recvmsg(struct kiocb iocb, struct sock sk,
	struct msghdr *msg, size_t len, int nonblock,
	int flags, int *addr_len);
	extern void dccp_shutdown(struct sock *sk, int how);

	extern int dccp_v4_checksum(const struct sk_buff *skb,
	const u32 saddr, const u32 daddr);

	extern int dccp_v4_send_reset(struct sock *sk,
	enum dccp_reset_codes code);
	extern void dccp_send_close(struct sock *sk, const int active);

	struct dccp_skb_cb {
	__u8 dccpd_type;
	__u8 dccpd_reset_code;
	__u8 dccpd_service;
	__u8 dccpd_ccval;
	__u64 dccpd_seq;
	__u64 dccpd_ack_seq;
	int dccpd_opt_len;
	};

	#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))

	static inline int dccp_non_data_packet(const struct sk_buff *skb)
	{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_ACK \|\|
	type == DCCP_PKT_CLOSE \|\|
	type == DCCP_PKT_CLOSEREQ \|\|
	type == DCCP_PKT_RESET \|\|
	type == DCCP_PKT_SYNC \|\|
	type == DCCP_PKT_SYNCACK;
	}

	static inline int dccp_packet_without_ack(const struct sk_buff *skb)
	{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_DATA \|\| type == DCCP_PKT_REQUEST;
	}

	#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
	#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)

	static inline void dccp_set_seqno(u64 *seqno, u64 value)
	{
	if (value > DCCP_MAX_SEQNO)
	value -= DCCP_MAX_SEQNO + 1;
	*seqno = value;
	}

	static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
	{
	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
	}

	static inline void dccp_inc_seqno(u64 *seqno)
	{
	if (++*seqno > DCCP_MAX_SEQNO)
	*seqno = 0;
	}

	static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
	{
	struct dccp_hdr_ext dhx = (struct dccp_hdr_ext )((void *)dh +
	sizeof(*dh));

	#if defined(__LITTLE_ENDIAN_BITFIELD)
	dh->dccph_seq = htonl((gss >> 32)) >> 8;
	#elif defined(__BIG_ENDIAN_BITFIELD)
	dh->dccph_seq = htonl((gss >> 32));
	#else
	#error "Adjust your <asm/byteorder.h> defines"
	#endif
	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
	}

	static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
	const u64 gsr)
	{
	#if defined(__LITTLE_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
	#elif defined(__BIG_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32));
	#else
	#error "Adjust your <asm/byteorder.h> defines"
	#endif
	dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
	}

	static inline void dccp_update_gsr(struct sock *sk, u64 seq)
	{
	struct dccp_sock *dp = dccp_sk(sk);

	dp->dccps_gsr = seq;
	dccp_set_seqno(&dp->dccps_swl,
	(dp->dccps_gsr + 1 -
	(dp->dccps_options.dccpo_sequence_window / 4)));
	dccp_set_seqno(&dp->dccps_swh,
	(dp->dccps_gsr +
	(3 * dp->dccps_options.dccpo_sequence_window) / 4));
	}

	static inline void dccp_update_gss(struct sock *sk, u64 seq)
	{
	struct dccp_sock *dp = dccp_sk(sk);

	dp->dccps_awh = dp->dccps_gss = seq;
	dccp_set_seqno(&dp->dccps_awl,
	(dp->dccps_gss -
	dp->dccps_options.dccpo_sequence_window + 1));
	}

	extern void dccp_insert_options(struct sock sk, struct sk_buff skb);
	extern void dccp_insert_option_elapsed_time(struct sock *sk,
	struct sk_buff *skb,
	u32 elapsed_time);
	extern void dccp_insert_option_timestamp(struct sock *sk,
	struct sk_buff *skb);
	extern void dccp_insert_option(struct sock sk, struct sk_buff skb,
	unsigned char option,
	const void *value, unsigned char len);

	extern struct socket *dccp_ctl_socket;

	#define DCCP_ACKPKTS_STATE_RECEIVED 0
	#define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
	#define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)

	#define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
	#define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */

	/** struct dccp_ackpkts - acknowledgeable packets
	*
	* This data structure is the one defined in the DCCP draft
	* Appendix A.
	*
	* @dccpap_buf_head - circular buffer head
	* @dccpap_buf_tail - circular buffer tail
	* @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
	* buffer (i.e. %dccpap_buf_head)
	* @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
	* by the buffer with State 0
	*
	* Additionally, the HC-Receiver must keep some information about the
	* Ack Vectors it has recently sent. For each packet sent carrying an
	* Ack Vector, it remembers four variables:
	*
	* @dccpap_ack_seqno - the Sequence Number used for the packet
	* (HC-Receiver seqno)
	* @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
	* @dccpap_ack_ackno - the Acknowledgement Number used for the packet
	* (HC-Sender seqno)
	* @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
	*
	* @dccpap_buf_len - circular buffer length
	* @dccpap_time - the time in usecs
	* @dccpap_buf - circular buffer of acknowledgeable packets
	*/
	struct dccp_ackpkts {
	unsigned int dccpap_buf_head;
	unsigned int dccpap_buf_tail;
	u64 dccpap_buf_ackno;
	u64 dccpap_ack_seqno;
	u64 dccpap_ack_ackno;
	unsigned int dccpap_ack_ptr;
	unsigned int dccpap_buf_vector_len;
	unsigned int dccpap_ack_vector_len;
	unsigned int dccpap_buf_len;
	struct timeval dccpap_time;
	u8 dccpap_buf_nonce;
	u8 dccpap_ack_nonce;
	u8 dccpap_buf[0];
	};

	extern struct dccp_ackpkts *
	dccp_ackpkts_alloc(unsigned int len,
	const unsigned int __nocast priority);
	extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
	extern int dccp_ackpkts_add(struct dccp_ackpkts ap, const struct sock sk,
	u64 ackno, u8 state);
	extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
	struct sock *sk, u64 ackno);

	extern void dccp_timestamp(const struct sock sk, struct timeval tv);

	static inline suseconds_t timeval_usecs(const struct timeval *tv)
	{
	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
	}

	static inline suseconds_t timeval_delta(const struct timeval *large,
	const struct timeval *small)
	{
	time_t secs = large->tv_sec - small->tv_sec;
	suseconds_t usecs = large->tv_usec - small->tv_usec;

	if (usecs < 0) {
	secs--;
	usecs += USEC_PER_SEC;
	}
	return secs * USEC_PER_SEC + usecs;
	}

	static inline void timeval_add_usecs(struct timeval *tv,
	const suseconds_t usecs)
	{
	tv->tv_usec += usecs;
	while (tv->tv_usec >= USEC_PER_SEC) {
	tv->tv_sec++;
	tv->tv_usec -= USEC_PER_SEC;
	}
	}

	static inline void timeval_sub_usecs(struct timeval *tv,
	const suseconds_t usecs)
	{
	tv->tv_usec -= usecs;
	while (tv->tv_usec < 0) {
	tv->tv_sec--;
	tv->tv_usec += USEC_PER_SEC;
	}
	}

	#ifdef CONFIG_IP_DCCP_DEBUG
	extern void dccp_ackvector_print(const u64 ackno,
	const unsigned char *vector, int len);
	extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
	#else
	static inline void dccp_ackvector_print(const u64 ackno,
	const unsigned char *vector,
	int len) { }
	static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
	#endif

	#endif /* _DCCP_H */