[mirror_ubuntu-bionic-kernel.git] / net / dccp / 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) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.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/dccp.h>
#include <net/snmp.h>
#include <net/sock.h>
#include <net/tcp.h>
#include "ackvec.h"

/*
 * 	DCCP - specific warning and debugging macros.
 */
#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt,       \
							__FUNCTION__, ##a)
#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
					 __FILE__, __LINE__, __FUNCTION__)
#define DCCP_BUG(a...)       do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
#define DCCP_BUG_ON(cond)    do { if (unlikely((cond) != 0))		   \
				     DCCP_BUG("\"%s\" holds (exception!)", \
					      __stringify(cond));          \
			     } while (0)

#define DCCP_PRINTK(enable, fmt, args...)	do { if (enable)	     \
							printk(fmt, ##args); \
						} while(0)
#define DCCP_PR_DEBUG(enable, fmt, a...)	DCCP_PRINTK(enable, KERN_DEBUG \
						  "%s: " fmt, __FUNCTION__, ##a)

#ifdef CONFIG_IP_DCCP_DEBUG
extern int dccp_debug;
#define dccp_pr_debug(format, a...)	  DCCP_PR_DEBUG(dccp_debug, format, ##a)
#define dccp_pr_debug_cat(format, a...)   DCCP_PRINTK(dccp_debug, format, ##a)
#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 void dccp_time_wait(struct sock *sk, int state, int timeo);

/*
 *  Set safe upper bounds for header and option length. Since Data Offset is 8
 *  bits (RFC 4340, sec. 5.1), the total header length can never be more than
 *  4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
 *    - DCCP-Response with ACK Subheader and 4 bytes of Service code      OR
 *    - DCCP-Reset    with ACK Subheader and 4 bytes of Reset Code fields
 *  Hence a safe upper bound for the maximum option length is 1020-28 = 992
 */
#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
#define DCCP_MAX_PACKET_HDR 28
#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)

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

/* RFC 1122, 4.2.3.1 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 */

/* sysctl variables for DCCP */
extern int  sysctl_dccp_request_retries;
extern int  sysctl_dccp_retries1;
extern int  sysctl_dccp_retries2;
extern int  sysctl_dccp_feat_sequence_window;
extern int  sysctl_dccp_feat_rx_ccid;
extern int  sysctl_dccp_feat_tx_ccid;
extern int  sysctl_dccp_feat_ack_ratio;
extern int  sysctl_dccp_feat_send_ack_vector;
extern int  sysctl_dccp_feat_send_ndp_count;
extern int  sysctl_dccp_tx_qlen;

/*
 *	48-bit sequence number arithmetic (signed and unsigned)
 */
#define INT48_MIN	  0x800000000000LL		/* 2^47	    */
#define UINT48_MAX	  0xFFFFFFFFFFFFLL		/* 2^48 - 1 */
#define COMPLEMENT48(x)	 (0x1000000000000LL - (x))	/* 2^48 - x */
#define TO_SIGNED48(x)	 (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
#define TO_UNSIGNED48(x) (((x) >= 0)?	     (x) :  COMPLEMENT48(-(x)))
#define ADD48(a, b)	 (((a) + (b)) & UINT48_MAX)
#define SUB48(a, b)	 ADD48((a), COMPLEMENT48(b))

static inline void dccp_set_seqno(u64 *seqno, u64 value)
{
	*seqno = value & UINT48_MAX;
}

static inline void dccp_inc_seqno(u64 *seqno)
{
	*seqno = ADD48(*seqno, 1);
}

/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
{
	u64 delta = SUB48(seqno2, seqno1);

	return TO_SIGNED48(delta);
}

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

/* is seq1 > seq2 ? */
#define after48(seq1, seq2)	before48(seq2, seq1)

/* 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;
}

/* is seq1 next seqno after seq2 */
static inline int follows48(const u64 seq1, const u64 seq2)
{
	return dccp_delta_seqno(seq2, seq1) == 1;
}

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)

/*
 * 	Checksumming routines
 */
static inline int dccp_csum_coverage(const struct sk_buff *skb)
{
	const struct dccp_hdr* dh = dccp_hdr(skb);

	if (dh->dccph_cscov == 0)
		return skb->len;
	return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
}

static inline void dccp_csum_outgoing(struct sk_buff *skb)
{
	int cov = dccp_csum_coverage(skb);

	if (cov >= skb->len)
		dccp_hdr(skb)->dccph_cscov = 0;

	skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
}

extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);

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

extern void dccp_send_ack(struct sock *sk);
extern void dccp_send_delayed_ack(struct sock *sk);
extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);

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

extern void dccp_write_xmit(struct sock *sk, int block);
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);

extern void dccp_set_state(struct sock *sk, const int state);
extern void dccp_done(struct sock *sk);

extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);

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 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 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
extern int dccp_destroy_sock(struct sock *sk);

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 int	   dccp_connect(struct sock *sk);
extern int	   dccp_disconnect(struct sock *sk, int flags);
extern void	   dccp_hash(struct sock *sk);
extern void	   dccp_unhash(struct sock *sk);
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);
#ifdef CONFIG_COMPAT
extern int	   compat_dccp_getsockopt(struct sock *sk,
				int level, int optname,
				char __user *optval, int __user *optlen);
extern int	   compat_dccp_setsockopt(struct sock *sk,
				int level, int optname,
				char __user *optval, int optlen);
#endif
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	   inet_dccp_listen(struct socket *sock, int backlog);
extern unsigned int dccp_poll(struct file *file, struct socket *sock,
			     poll_table *wait);
extern int	   dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
				   int addr_len);

extern int	   dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
extern void	   dccp_send_close(struct sock *sk, const int active);
extern int	   dccp_invalid_packet(struct sk_buff *skb);

static inline int dccp_bad_service_code(const struct sock *sk,
					const __be32 service)
{
	const struct dccp_sock *dp = dccp_sk(sk);

	if (dp->dccps_service == service)
		return 0;
	return !dccp_list_has_service(dp->dccps_service_list, service);
}

struct dccp_skb_cb {
	__u8  dccpd_type:4;
	__u8  dccpd_ccval:4;
	__u8  dccpd_reset_code;
	__u16 dccpd_opt_len;
	__u64 dccpd_seq;
	__u64 dccpd_ack_seq;
};

#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_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)

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));
	dh->dccph_seq2 = 0;
	dh->dccph_seq = htons((gss >> 32) & 0xfffff);
	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
}

static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
				    const u64 gsr)
{
	dhack->dccph_reserved1 = 0;
	dhack->dccph_ack_nr_high = htons(gsr >> 32);
	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);
	const struct dccp_minisock *dmsk = dccp_msk(sk);

	dp->dccps_gsr = seq;
	dccp_set_seqno(&dp->dccps_swl,
		       dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
	dccp_set_seqno(&dp->dccps_swh,
		       dp->dccps_gsr + (3 * dmsk->dccpms_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 -
			dccp_msk(sk)->dccpms_sequence_window + 1));
}

static inline int dccp_ack_pending(const struct sock *sk)
{
	const struct dccp_sock *dp = dccp_sk(sk);
	return dp->dccps_timestamp_echo != 0 ||
#ifdef CONFIG_IP_DCCP_ACKVEC
	       (dccp_msk(sk)->dccpms_send_ack_vector &&
		dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
#endif
	       inet_csk_ack_scheduled(sk);
}

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

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;
	}
	DCCP_BUG_ON(tv->tv_sec < 0);
}

#ifdef CONFIG_SYSCTL
extern int dccp_sysctl_init(void);
extern void dccp_sysctl_exit(void);
#else
static inline int dccp_sysctl_init(void)
{
	return 0;
}

static inline void dccp_sysctl_exit(void)
{
}
#endif

#endif /* _DCCP_H */
Commit	Line	Data
7c657876 ACM	1	#ifndef _DCCP_H
	2	#define _DCCP_H
	3	/*
	4	* net/dccp/dccp.h
	5	*
	6	* An implementation of the DCCP protocol
1bc09869	7	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
e6bccd35	8	* Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
7c657876 ACM	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
	15	#include <linux/dccp.h>
	16	#include <net/snmp.h>
	17	#include <net/sock.h>
	18	#include <net/tcp.h>
ae31c339	19	#include "ackvec.h"
7c657876	20
59348b19 GR	21	/*
	22	* DCCP - specific warning and debugging macros.
	23	*/
	24	#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
c9eaf173	25	__FUNCTION__, ##a)
59348b19 GR	26	#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
	27	__FILE__, __LINE__, __FUNCTION__)
	28	#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
	29	#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
	30	DCCP_BUG("\"%s\" holds (exception!)", \
	31	__stringify(cond)); \
3c695262 GR	32	} while (0)
3c695262 GR	33
84116716 GR	34	#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
84116716 GR	35	printk(fmt, ##args); \
c9eaf173	36	} while(0)
84116716 GR	37	#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
	38	"%s: " fmt, __FUNCTION__, ##a)
	39
725ba8ee	40	#ifdef CONFIG_IP_DCCP_DEBUG
7c657876	41	extern int dccp_debug;
84116716 GR	42	#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
84116716 GR	43	#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
7c657876 ACM	44	#else
	45	#define dccp_pr_debug(format, a...)
	46	#define dccp_pr_debug_cat(format, a...)
	47	#endif
	48
	49	extern struct inet_hashinfo dccp_hashinfo;
	50
	51	extern atomic_t dccp_orphan_count;
7c657876 ACM	52
	53	extern void dccp_time_wait(struct sock *sk, int state, int timeo);
	54
60361be1 GR	55	/*
	56	* Set safe upper bounds for header and option length. Since Data Offset is 8
	57	* bits (RFC 4340, sec. 5.1), the total header length can never be more than
	58	* 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
	59	* - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
	60	* - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
	61	* Hence a safe upper bound for the maximum option length is 1020-28 = 992
	62	*/
	63	#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
	64	#define DCCP_MAX_PACKET_HDR 28
	65	#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
	66	#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
7c657876 ACM	67
	68	#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
	69	* state, about 60 seconds */
	70
0e64e94e	71	/* RFC 1122, 4.2.3.1 initial RTO value */
7c657876 ACM	72	#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
	73
	74	/* Maximal interval between probes for local resources. */
	75	#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
	76
	77	#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
	78
2e2e9e92 GR	79	/* sysctl variables for DCCP */
	80	extern int sysctl_dccp_request_retries;
	81	extern int sysctl_dccp_retries1;
	82	extern int sysctl_dccp_retries2;
afb0a34d GR	83	extern int sysctl_dccp_feat_sequence_window;
	84	extern int sysctl_dccp_feat_rx_ccid;
	85	extern int sysctl_dccp_feat_tx_ccid;
	86	extern int sysctl_dccp_feat_ack_ratio;
	87	extern int sysctl_dccp_feat_send_ack_vector;
	88	extern int sysctl_dccp_feat_send_ndp_count;
b1308dc0	89	extern int sysctl_dccp_tx_qlen;
2e2e9e92	90
6b811d43 GR	91	/*
	92	* 48-bit sequence number arithmetic (signed and unsigned)
	93	*/
	94	#define INT48_MIN 0x800000000000LL /* 2^47 */
	95	#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
	96	#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
	97	#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
	98	#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
	99	#define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
	100	#define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
	101
	102	static inline void dccp_set_seqno(u64 *seqno, u64 value)
	103	{
	104	*seqno = value & UINT48_MAX;
	105	}
	106
	107	static inline void dccp_inc_seqno(u64 *seqno)
	108	{
	109	seqno = ADD48(seqno, 1);
	110	}
	111
0aec51c8 GR	112	/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
0aec51c8 GR	113	static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
6b811d43	114	{
0aec51c8 GR	115	u64 delta = SUB48(seqno2, seqno1);
	116
	117	return TO_SIGNED48(delta);
6b811d43 GR	118	}
6b811d43 GR	119
7c657876	120	/* is seq1 < seq2 ? */
a10cedd4	121	static inline int before48(const u64 seq1, const u64 seq2)
7c657876	122	{
d52de17b	123	return (s64)((seq2 << 16) - (seq1 << 16)) > 0;
7c657876 ACM	124	}
	125
	126	/* is seq1 > seq2 ? */
d52de17b	127	#define after48(seq1, seq2) before48(seq2, seq1)
7c657876 ACM	128
7c657876 ACM	129	/* is seq2 <= seq1 <= seq3 ? */
a10cedd4	130	static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
7c657876 ACM	131	{
	132	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
	133	}
	134
	135	static inline u64 max48(const u64 seq1, const u64 seq2)
	136	{
	137	return after48(seq1, seq2) ? seq1 : seq2;
	138	}
	139
837d107c IM	140	/* is seq1 next seqno after seq2 */
	141	static inline int follows48(const u64 seq1, const u64 seq2)
	142	{
b16be51b	143	return dccp_delta_seqno(seq2, seq1) == 1;
837d107c IM	144	}
837d107c IM	145
7c657876 ACM	146	enum {
	147	DCCP_MIB_NUM = 0,
	148	DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
	149	DCCP_MIB_ESTABRESETS, /* EstabResets */
	150	DCCP_MIB_CURRESTAB, /* CurrEstab */
c9eaf173	151	DCCP_MIB_OUTSEGS, /* OutSegs */
7c657876 ACM	152	DCCP_MIB_OUTRSTS,
	153	DCCP_MIB_ABORTONTIMEOUT,
	154	DCCP_MIB_TIMEOUTS,
	155	DCCP_MIB_ABORTFAILED,
	156	DCCP_MIB_PASSIVEOPENS,
	157	DCCP_MIB_ATTEMPTFAILS,
	158	DCCP_MIB_OUTDATAGRAMS,
	159	DCCP_MIB_INERRS,
	160	DCCP_MIB_OPTMANDATORYERROR,
	161	DCCP_MIB_INVALIDOPT,
	162	__DCCP_MIB_MAX
	163	};
	164
	165	#define DCCP_MIB_MAX __DCCP_MIB_MAX
	166	struct dccp_mib {
	167	unsigned long mibs[DCCP_MIB_MAX];
	168	} __SNMP_MIB_ALIGN__;
	169
	170	DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
7690af3f ACM	171	#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
	172	#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
	173	#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
	174	#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
	175	#define DCCP_ADD_STATS_BH(field, val) \
	176	SNMP_ADD_STATS_BH(dccp_statistics, field, val)
	177	#define DCCP_ADD_STATS_USER(field, val) \
	178	SNMP_ADD_STATS_USER(dccp_statistics, field, val)
7c657876	179
6f4e5fff GR	180	/*
	181	* Checksumming routines
	182	*/
	183	static inline int dccp_csum_coverage(const struct sk_buff *skb)
	184	{
	185	const struct dccp_hdr* dh = dccp_hdr(skb);
	186
	187	if (dh->dccph_cscov == 0)
	188	return skb->len;
	189	return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
	190	}
	191
	192	static inline void dccp_csum_outgoing(struct sk_buff *skb)
	193	{
	194	int cov = dccp_csum_coverage(skb);
	195
	196	if (cov >= skb->len)
	197	dccp_hdr(skb)->dccph_cscov = 0;
	198
	199	skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
	200	}
	201
	202	extern void dccp_v4_send_check(struct sock sk, int len, struct sk_buff skb);
	203
7c657876 ACM	204	extern int dccp_retransmit_skb(struct sock sk, struct sk_buff skb);
7c657876 ACM	205
7c657876 ACM	206	extern void dccp_send_ack(struct sock *sk);
7c657876 ACM	207	extern void dccp_send_delayed_ack(struct sock *sk);
8a73cd09 GR	208	extern void dccp_reqsk_send_ack(struct sk_buff sk, struct request_sock rsk);
8a73cd09 GR	209
e92ae93a ACM	210	extern void dccp_send_sync(struct sock *sk, const u64 seq,
e92ae93a ACM	211	const enum dccp_pkt_type pkt_type);
7c657876	212
97e5848d	213	extern void dccp_write_xmit(struct sock *sk, int block);
c530cfb1	214	extern void dccp_write_space(struct sock *sk);
27258ee5	215
7c657876 ACM	216	extern void dccp_init_xmit_timers(struct sock *sk);
	217	static inline void dccp_clear_xmit_timers(struct sock *sk)
	218	{
	219	inet_csk_clear_xmit_timers(sk);
	220	}
	221
	222	extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
	223
	224	extern const char *dccp_packet_name(const int type);
	225	extern const char *dccp_state_name(const int state);
	226
c25a18ba ACM	227	extern void dccp_set_state(struct sock *sk, const int state);
c25a18ba ACM	228	extern void dccp_done(struct sock *sk);
7c657876	229
cf557926	230	extern void dccp_reqsk_init(struct request_sock req, struct sk_buff skb);
7c657876	231
7c657876 ACM	232	extern int dccp_v4_conn_request(struct sock sk, struct sk_buff skb);
	233
	234	extern struct sock dccp_create_openreq_child(struct sock sk,
	235	const struct request_sock *req,
	236	const struct sk_buff *skb);
	237
	238	extern int dccp_v4_do_rcv(struct sock sk, struct sk_buff skb);
	239
7c657876 ACM	240	extern struct sock dccp_v4_request_recv_sock(struct sock sk,
	241	struct sk_buff *skb,
	242	struct request_sock *req,
	243	struct dst_entry *dst);
	244	extern struct sock dccp_check_req(struct sock sk, struct sk_buff *skb,
	245	struct request_sock *req,
	246	struct request_sock **prev);
	247
	248	extern int dccp_child_process(struct sock parent, struct sock child,
	249	struct sk_buff *skb);
	250	extern int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
	251	struct dccp_hdr *dh, unsigned len);
	252	extern int dccp_rcv_established(struct sock sk, struct sk_buff skb,
	253	const struct dccp_hdr *dh, const unsigned len);
	254
72478873	255	extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
3e0fadc5	256	extern int dccp_destroy_sock(struct sock *sk);
f21e68ca	257
7c657876 ACM	258	extern void dccp_close(struct sock *sk, long timeout);
	259	extern struct sk_buff dccp_make_response(struct sock sk,
	260	struct dst_entry *dst,
	261	struct request_sock *req);
	262
	263	extern int dccp_connect(struct sock *sk);
	264	extern int dccp_disconnect(struct sock *sk, int flags);
c985ed70	265	extern void dccp_hash(struct sock *sk);
f21e68ca	266	extern void dccp_unhash(struct sock *sk);
7c657876	267	extern int dccp_getsockopt(struct sock *sk, int level, int optname,
a1d3a355 ACM	268	char __user optval, int __user optlen);
	269	extern int dccp_setsockopt(struct sock *sk, int level, int optname,
	270	char __user *optval, int optlen);
3fdadf7d DM	271	#ifdef CONFIG_COMPAT
	272	extern int compat_dccp_getsockopt(struct sock *sk,
	273	int level, int optname,
	274	char __user optval, int __user optlen);
	275	extern int compat_dccp_setsockopt(struct sock *sk,
	276	int level, int optname,
	277	char __user *optval, int optlen);
	278	#endif
7c657876	279	extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
7690af3f ACM	280	extern int dccp_sendmsg(struct kiocb iocb, struct sock sk,
7690af3f ACM	281	struct msghdr *msg, size_t size);
7c657876 ACM	282	extern int dccp_recvmsg(struct kiocb iocb, struct sock sk,
	283	struct msghdr *msg, size_t len, int nonblock,
	284	int flags, int *addr_len);
7c657876	285	extern void dccp_shutdown(struct sock *sk, int how);
f21e68ca ACM	286	extern int inet_dccp_listen(struct socket *sock, int backlog);
	287	extern unsigned int dccp_poll(struct file file, struct socket sock,
	288	poll_table *wait);
f21e68ca ACM	289	extern int dccp_v4_connect(struct sock sk, struct sockaddr uaddr,
f21e68ca ACM	290	int addr_len);
7c657876	291
017487d7	292	extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
7ad07e7c	293	extern void dccp_send_close(struct sock *sk, const int active);
f21e68ca ACM	294	extern int dccp_invalid_packet(struct sk_buff *skb);
	295
	296	static inline int dccp_bad_service_code(const struct sock *sk,
60fe62e7	297	const __be32 service)
f21e68ca ACM	298	{
	299	const struct dccp_sock *dp = dccp_sk(sk);
	300
	301	if (dp->dccps_service == service)
	302	return 0;
	303	return !dccp_list_has_service(dp->dccps_service_list, service);
	304	}
7c657876 ACM	305
7c657876 ACM	306	struct dccp_skb_cb {
67e6b629 ACM	307	__u8 dccpd_type:4;
	308	__u8 dccpd_ccval:4;
	309	__u8 dccpd_reset_code;
	310	__u16 dccpd_opt_len;
7c657876 ACM	311	__u64 dccpd_seq;
7c657876 ACM	312	__u64 dccpd_ack_seq;
7c657876 ACM	313	};
	314
	315	#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
	316
	317	static inline int dccp_non_data_packet(const struct sk_buff *skb)
	318	{
	319	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	320
	321	return type == DCCP_PKT_ACK \|\|
	322	type == DCCP_PKT_CLOSE \|\|
	323	type == DCCP_PKT_CLOSEREQ \|\|
	324	type == DCCP_PKT_RESET \|\|
	325	type == DCCP_PKT_SYNC \|\|
	326	type == DCCP_PKT_SYNCACK;
	327	}
	328
	329	static inline int dccp_packet_without_ack(const struct sk_buff *skb)
	330	{
	331	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	332
	333	return type == DCCP_PKT_DATA \|\| type == DCCP_PKT_REQUEST;
	334	}
	335
6b811d43	336	#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
7c657876 ACM	337
	338	static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
	339	{
7690af3f ACM	340	struct dccp_hdr_ext dhx = (struct dccp_hdr_ext )((void *)dh +
7690af3f ACM	341	sizeof(*dh));
60fe62e7 AB	342	dh->dccph_seq2 = 0;
60fe62e7 AB	343	dh->dccph_seq = htons((gss >> 32) & 0xfffff);
7c657876 ACM	344	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
	345	}
	346
7690af3f ACM	347	static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
7690af3f ACM	348	const u64 gsr)
7c657876	349	{
60fe62e7 AB	350	dhack->dccph_reserved1 = 0;
60fe62e7 AB	351	dhack->dccph_ack_nr_high = htons(gsr >> 32);
7c657876 ACM	352	dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
	353	}
	354
	355	static inline void dccp_update_gsr(struct sock *sk, u64 seq)
	356	{
	357	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	358	const struct dccp_minisock *dmsk = dccp_msk(sk);
7c657876	359
03ace394 ACM	360	dp->dccps_gsr = seq;
03ace394 ACM	361	dccp_set_seqno(&dp->dccps_swl,
a4bf3902	362	dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
7c657876	363	dccp_set_seqno(&dp->dccps_swh,
a4bf3902	364	dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
7c657876 ACM	365	}
	366
	367	static inline void dccp_update_gss(struct sock *sk, u64 seq)
	368	{
	369	struct dccp_sock *dp = dccp_sk(sk);
7c657876	370
03ace394 ACM	371	dp->dccps_awh = dp->dccps_gss = seq;
03ace394 ACM	372	dccp_set_seqno(&dp->dccps_awl,
7690af3f	373	(dp->dccps_gss -
a4bf3902	374	dccp_msk(sk)->dccpms_sequence_window + 1));
7c657876	375	}
c9eaf173	376
ae31c339 ACM	377	static inline int dccp_ack_pending(const struct sock *sk)
	378	{
	379	const struct dccp_sock *dp = dccp_sk(sk);
	380	return dp->dccps_timestamp_echo != 0 \|\|
	381	#ifdef CONFIG_IP_DCCP_ACKVEC
a4bf3902	382	(dccp_msk(sk)->dccpms_send_ack_vector &&
ae31c339 ACM	383	dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) \|\|
	384	#endif
	385	inet_csk_ack_scheduled(sk);
	386	}
7c657876	387
2d0817d1 ACM	388	extern int dccp_insert_options(struct sock sk, struct sk_buff skb);
2d0817d1 ACM	389	extern int dccp_insert_option_elapsed_time(struct sock *sk,
7c657876 ACM	390	struct sk_buff *skb,
7c657876 ACM	391	u32 elapsed_time);
2d0817d1	392	extern int dccp_insert_option_timestamp(struct sock *sk,
d4b81ff7	393	struct sk_buff *skb);
2d0817d1	394	extern int dccp_insert_option(struct sock sk, struct sk_buff skb,
7c657876 ACM	395	unsigned char option,
	396	const void *value, unsigned char len);
	397
b0e56780 ACM	398	extern void dccp_timestamp(const struct sock sk, struct timeval tv);
b0e56780 ACM	399
b6ee3d4a ACM	400	static inline suseconds_t timeval_usecs(const struct timeval *tv)
	401	{
	402	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
	403	}
	404
	405	static inline suseconds_t timeval_delta(const struct timeval *large,
	406	const struct timeval *small)
	407	{
	408	time_t secs = large->tv_sec - small->tv_sec;
	409	suseconds_t usecs = large->tv_usec - small->tv_usec;
	410
	411	if (usecs < 0) {
	412	secs--;
	413	usecs += USEC_PER_SEC;
	414	}
	415	return secs * USEC_PER_SEC + usecs;
	416	}
	417
	418	static inline void timeval_add_usecs(struct timeval *tv,
	419	const suseconds_t usecs)
	420	{
	421	tv->tv_usec += usecs;
	422	while (tv->tv_usec >= USEC_PER_SEC) {
	423	tv->tv_sec++;
	424	tv->tv_usec -= USEC_PER_SEC;
	425	}
	426	}
	427
	428	static inline void timeval_sub_usecs(struct timeval *tv,
	429	const suseconds_t usecs)
	430	{
	431	tv->tv_usec -= usecs;
	432	while (tv->tv_usec < 0) {
	433	tv->tv_sec--;
	434	tv->tv_usec += USEC_PER_SEC;
	435	}
0f9e5b57	436	DCCP_BUG_ON(tv->tv_sec < 0);
b6ee3d4a ACM	437	}
b6ee3d4a ACM	438
e55d912f ACM	439	#ifdef CONFIG_SYSCTL
	440	extern int dccp_sysctl_init(void);
	441	extern void dccp_sysctl_exit(void);
	442	#else
	443	static inline int dccp_sysctl_init(void)
	444	{
	445	return 0;
	446	}
	447
	448	static inline void dccp_sysctl_exit(void)
	449	{
	450	}
	451	#endif
	452
7c657876	453	#endif /* _DCCP_H */