[deliverable/linux.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)

#ifdef MODULE
#define DCCP_PRINTK(enable, fmt, args...)	do { if (enable)	     \
							printk(fmt, ##args); \
						} while(0)
#else
#define DCCP_PRINTK(enable, fmt, args...)	printk(fmt, ##args)
#endif
#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)((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;
}

/* is seq1 next seqno after seq2 */
static inline int follows48(const u64 seq1, const u64 seq2)
{
	int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);

	return diff==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	#ifdef MODULE
	35	#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
	36	printk(fmt, ##args); \
c9eaf173	37	} while(0)
84116716 GR	38	#else
	39	#define DCCP_PRINTK(enable, fmt, args...) printk(fmt, ##args)
	40	#endif
	41	#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
	42	"%s: " fmt, __FUNCTION__, ##a)
	43
725ba8ee	44	#ifdef CONFIG_IP_DCCP_DEBUG
7c657876	45	extern int dccp_debug;
84116716 GR	46	#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
84116716 GR	47	#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
7c657876 ACM	48	#else
	49	#define dccp_pr_debug(format, a...)
	50	#define dccp_pr_debug_cat(format, a...)
	51	#endif
	52
	53	extern struct inet_hashinfo dccp_hashinfo;
	54
	55	extern atomic_t dccp_orphan_count;
7c657876 ACM	56
	57	extern void dccp_time_wait(struct sock *sk, int state, int timeo);
	58
60361be1 GR	59	/*
	60	* Set safe upper bounds for header and option length. Since Data Offset is 8
	61	* bits (RFC 4340, sec. 5.1), the total header length can never be more than
	62	* 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
	63	* - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
	64	* - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
	65	* Hence a safe upper bound for the maximum option length is 1020-28 = 992
	66	*/
	67	#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
	68	#define DCCP_MAX_PACKET_HDR 28
	69	#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
	70	#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
7c657876 ACM	71
	72	#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
	73	* state, about 60 seconds */
	74
0e64e94e	75	/* RFC 1122, 4.2.3.1 initial RTO value */
7c657876 ACM	76	#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
	77
	78	/* Maximal interval between probes for local resources. */
	79	#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
	80
	81	#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
	82
2e2e9e92 GR	83	/* sysctl variables for DCCP */
	84	extern int sysctl_dccp_request_retries;
	85	extern int sysctl_dccp_retries1;
	86	extern int sysctl_dccp_retries2;
afb0a34d GR	87	extern int sysctl_dccp_feat_sequence_window;
	88	extern int sysctl_dccp_feat_rx_ccid;
	89	extern int sysctl_dccp_feat_tx_ccid;
	90	extern int sysctl_dccp_feat_ack_ratio;
	91	extern int sysctl_dccp_feat_send_ack_vector;
	92	extern int sysctl_dccp_feat_send_ndp_count;
b1308dc0	93	extern int sysctl_dccp_tx_qlen;
2e2e9e92	94
6b811d43 GR	95	/*
	96	* 48-bit sequence number arithmetic (signed and unsigned)
	97	*/
	98	#define INT48_MIN 0x800000000000LL /* 2^47 */
	99	#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
	100	#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
	101	#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
	102	#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
	103	#define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
	104	#define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
	105
	106	static inline void dccp_set_seqno(u64 *seqno, u64 value)
	107	{
	108	*seqno = value & UINT48_MAX;
	109	}
	110
	111	static inline void dccp_inc_seqno(u64 *seqno)
	112	{
	113	seqno = ADD48(seqno, 1);
	114	}
	115
0aec51c8 GR	116	/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
0aec51c8 GR	117	static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
6b811d43	118	{
0aec51c8 GR	119	u64 delta = SUB48(seqno2, seqno1);
	120
	121	return TO_SIGNED48(delta);
6b811d43 GR	122	}
6b811d43 GR	123
7c657876	124	/* is seq1 < seq2 ? */
a10cedd4	125	static inline int before48(const u64 seq1, const u64 seq2)
7c657876	126	{
a10cedd4	127	return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
7c657876 ACM	128	}
	129
	130	/* is seq1 > seq2 ? */
a10cedd4	131	static inline int after48(const u64 seq1, const u64 seq2)
7c657876	132	{
a10cedd4	133	return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
7c657876 ACM	134	}
	135
	136	/* is seq2 <= seq1 <= seq3 ? */
a10cedd4	137	static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
7c657876 ACM	138	{
	139	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
	140	}
	141
	142	static inline u64 max48(const u64 seq1, const u64 seq2)
	143	{
	144	return after48(seq1, seq2) ? seq1 : seq2;
	145	}
	146
837d107c IM	147	/* is seq1 next seqno after seq2 */
	148	static inline int follows48(const u64 seq1, const u64 seq2)
	149	{
	150	int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
	151
	152	return diff==1;
	153	}
	154
7c657876 ACM	155	enum {
	156	DCCP_MIB_NUM = 0,
	157	DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
	158	DCCP_MIB_ESTABRESETS, /* EstabResets */
	159	DCCP_MIB_CURRESTAB, /* CurrEstab */
c9eaf173	160	DCCP_MIB_OUTSEGS, /* OutSegs */
7c657876 ACM	161	DCCP_MIB_OUTRSTS,
	162	DCCP_MIB_ABORTONTIMEOUT,
	163	DCCP_MIB_TIMEOUTS,
	164	DCCP_MIB_ABORTFAILED,
	165	DCCP_MIB_PASSIVEOPENS,
	166	DCCP_MIB_ATTEMPTFAILS,
	167	DCCP_MIB_OUTDATAGRAMS,
	168	DCCP_MIB_INERRS,
	169	DCCP_MIB_OPTMANDATORYERROR,
	170	DCCP_MIB_INVALIDOPT,
	171	__DCCP_MIB_MAX
	172	};
	173
	174	#define DCCP_MIB_MAX __DCCP_MIB_MAX
	175	struct dccp_mib {
	176	unsigned long mibs[DCCP_MIB_MAX];
	177	} __SNMP_MIB_ALIGN__;
	178
	179	DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
7690af3f ACM	180	#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
	181	#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
	182	#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
	183	#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
	184	#define DCCP_ADD_STATS_BH(field, val) \
	185	SNMP_ADD_STATS_BH(dccp_statistics, field, val)
	186	#define DCCP_ADD_STATS_USER(field, val) \
	187	SNMP_ADD_STATS_USER(dccp_statistics, field, val)
7c657876	188
6f4e5fff GR	189	/*
	190	* Checksumming routines
	191	*/
	192	static inline int dccp_csum_coverage(const struct sk_buff *skb)
	193	{
	194	const struct dccp_hdr* dh = dccp_hdr(skb);
	195
	196	if (dh->dccph_cscov == 0)
	197	return skb->len;
	198	return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
	199	}
	200
	201	static inline void dccp_csum_outgoing(struct sk_buff *skb)
	202	{
	203	int cov = dccp_csum_coverage(skb);
	204
	205	if (cov >= skb->len)
	206	dccp_hdr(skb)->dccph_cscov = 0;
	207
	208	skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
	209	}
	210
	211	extern void dccp_v4_send_check(struct sock sk, int len, struct sk_buff skb);
	212
7c657876 ACM	213	extern int dccp_retransmit_skb(struct sock sk, struct sk_buff skb);
7c657876 ACM	214
7c657876 ACM	215	extern void dccp_send_ack(struct sock *sk);
7c657876 ACM	216	extern void dccp_send_delayed_ack(struct sock *sk);
8a73cd09 GR	217	extern void dccp_reqsk_send_ack(struct sk_buff sk, struct request_sock rsk);
8a73cd09 GR	218
e92ae93a ACM	219	extern void dccp_send_sync(struct sock *sk, const u64 seq,
e92ae93a ACM	220	const enum dccp_pkt_type pkt_type);
7c657876	221
97e5848d	222	extern void dccp_write_xmit(struct sock *sk, int block);
c530cfb1	223	extern void dccp_write_space(struct sock *sk);
27258ee5	224
7c657876 ACM	225	extern void dccp_init_xmit_timers(struct sock *sk);
	226	static inline void dccp_clear_xmit_timers(struct sock *sk)
	227	{
	228	inet_csk_clear_xmit_timers(sk);
	229	}
	230
	231	extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
	232
	233	extern const char *dccp_packet_name(const int type);
	234	extern const char *dccp_state_name(const int state);
	235
c25a18ba ACM	236	extern void dccp_set_state(struct sock *sk, const int state);
c25a18ba ACM	237	extern void dccp_done(struct sock *sk);
7c657876	238
cf557926	239	extern void dccp_reqsk_init(struct request_sock req, struct sk_buff skb);
7c657876	240
7c657876 ACM	241	extern int dccp_v4_conn_request(struct sock sk, struct sk_buff skb);
	242
	243	extern struct sock dccp_create_openreq_child(struct sock sk,
	244	const struct request_sock *req,
	245	const struct sk_buff *skb);
	246
	247	extern int dccp_v4_do_rcv(struct sock sk, struct sk_buff skb);
	248
7c657876 ACM	249	extern struct sock dccp_v4_request_recv_sock(struct sock sk,
	250	struct sk_buff *skb,
	251	struct request_sock *req,
	252	struct dst_entry *dst);
	253	extern struct sock dccp_check_req(struct sock sk, struct sk_buff *skb,
	254	struct request_sock *req,
	255	struct request_sock **prev);
	256
	257	extern int dccp_child_process(struct sock parent, struct sock child,
	258	struct sk_buff *skb);
	259	extern int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
	260	struct dccp_hdr *dh, unsigned len);
	261	extern int dccp_rcv_established(struct sock sk, struct sk_buff skb,
	262	const struct dccp_hdr *dh, const unsigned len);
	263
72478873	264	extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
3e0fadc5	265	extern int dccp_destroy_sock(struct sock *sk);
f21e68ca	266
7c657876 ACM	267	extern void dccp_close(struct sock *sk, long timeout);
	268	extern struct sk_buff dccp_make_response(struct sock sk,
	269	struct dst_entry *dst,
	270	struct request_sock *req);
	271
	272	extern int dccp_connect(struct sock *sk);
	273	extern int dccp_disconnect(struct sock *sk, int flags);
c985ed70	274	extern void dccp_hash(struct sock *sk);
f21e68ca	275	extern void dccp_unhash(struct sock *sk);
7c657876	276	extern int dccp_getsockopt(struct sock *sk, int level, int optname,
a1d3a355 ACM	277	char __user optval, int __user optlen);
	278	extern int dccp_setsockopt(struct sock *sk, int level, int optname,
	279	char __user *optval, int optlen);
3fdadf7d DM	280	#ifdef CONFIG_COMPAT
	281	extern int compat_dccp_getsockopt(struct sock *sk,
	282	int level, int optname,
	283	char __user optval, int __user optlen);
	284	extern int compat_dccp_setsockopt(struct sock *sk,
	285	int level, int optname,
	286	char __user *optval, int optlen);
	287	#endif
7c657876	288	extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
7690af3f ACM	289	extern int dccp_sendmsg(struct kiocb iocb, struct sock sk,
7690af3f ACM	290	struct msghdr *msg, size_t size);
7c657876 ACM	291	extern int dccp_recvmsg(struct kiocb iocb, struct sock sk,
	292	struct msghdr *msg, size_t len, int nonblock,
	293	int flags, int *addr_len);
7c657876	294	extern void dccp_shutdown(struct sock *sk, int how);
f21e68ca ACM	295	extern int inet_dccp_listen(struct socket *sock, int backlog);
	296	extern unsigned int dccp_poll(struct file file, struct socket sock,
	297	poll_table *wait);
f21e68ca ACM	298	extern int dccp_v4_connect(struct sock sk, struct sockaddr uaddr,
f21e68ca ACM	299	int addr_len);
7c657876	300
017487d7	301	extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
7ad07e7c	302	extern void dccp_send_close(struct sock *sk, const int active);
f21e68ca ACM	303	extern int dccp_invalid_packet(struct sk_buff *skb);
	304
	305	static inline int dccp_bad_service_code(const struct sock *sk,
60fe62e7	306	const __be32 service)
f21e68ca ACM	307	{
	308	const struct dccp_sock *dp = dccp_sk(sk);
	309
	310	if (dp->dccps_service == service)
	311	return 0;
	312	return !dccp_list_has_service(dp->dccps_service_list, service);
	313	}
7c657876 ACM	314
7c657876 ACM	315	struct dccp_skb_cb {
67e6b629 ACM	316	__u8 dccpd_type:4;
	317	__u8 dccpd_ccval:4;
	318	__u8 dccpd_reset_code;
	319	__u16 dccpd_opt_len;
7c657876 ACM	320	__u64 dccpd_seq;
7c657876 ACM	321	__u64 dccpd_ack_seq;
7c657876 ACM	322	};
	323
	324	#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
	325
	326	static inline int dccp_non_data_packet(const struct sk_buff *skb)
	327	{
	328	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	329
	330	return type == DCCP_PKT_ACK \|\|
	331	type == DCCP_PKT_CLOSE \|\|
	332	type == DCCP_PKT_CLOSEREQ \|\|
	333	type == DCCP_PKT_RESET \|\|
	334	type == DCCP_PKT_SYNC \|\|
	335	type == DCCP_PKT_SYNCACK;
	336	}
	337
	338	static inline int dccp_packet_without_ack(const struct sk_buff *skb)
	339	{
	340	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	341
	342	return type == DCCP_PKT_DATA \|\| type == DCCP_PKT_REQUEST;
	343	}
	344
6b811d43	345	#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
7c657876 ACM	346
	347	static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
	348	{
7690af3f ACM	349	struct dccp_hdr_ext dhx = (struct dccp_hdr_ext )((void *)dh +
7690af3f ACM	350	sizeof(*dh));
60fe62e7 AB	351	dh->dccph_seq2 = 0;
60fe62e7 AB	352	dh->dccph_seq = htons((gss >> 32) & 0xfffff);
7c657876 ACM	353	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
	354	}
	355
7690af3f ACM	356	static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
7690af3f ACM	357	const u64 gsr)
7c657876	358	{
60fe62e7 AB	359	dhack->dccph_reserved1 = 0;
60fe62e7 AB	360	dhack->dccph_ack_nr_high = htons(gsr >> 32);
7c657876 ACM	361	dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
	362	}
	363
	364	static inline void dccp_update_gsr(struct sock *sk, u64 seq)
	365	{
	366	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	367	const struct dccp_minisock *dmsk = dccp_msk(sk);
7c657876	368
03ace394 ACM	369	dp->dccps_gsr = seq;
03ace394 ACM	370	dccp_set_seqno(&dp->dccps_swl,
a4bf3902	371	dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
7c657876	372	dccp_set_seqno(&dp->dccps_swh,
a4bf3902	373	dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
7c657876 ACM	374	}
	375
	376	static inline void dccp_update_gss(struct sock *sk, u64 seq)
	377	{
	378	struct dccp_sock *dp = dccp_sk(sk);
7c657876	379
03ace394 ACM	380	dp->dccps_awh = dp->dccps_gss = seq;
03ace394 ACM	381	dccp_set_seqno(&dp->dccps_awl,
7690af3f	382	(dp->dccps_gss -
a4bf3902	383	dccp_msk(sk)->dccpms_sequence_window + 1));
7c657876	384	}
c9eaf173	385
ae31c339 ACM	386	static inline int dccp_ack_pending(const struct sock *sk)
	387	{
	388	const struct dccp_sock *dp = dccp_sk(sk);
	389	return dp->dccps_timestamp_echo != 0 \|\|
	390	#ifdef CONFIG_IP_DCCP_ACKVEC
a4bf3902	391	(dccp_msk(sk)->dccpms_send_ack_vector &&
ae31c339 ACM	392	dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) \|\|
	393	#endif
	394	inet_csk_ack_scheduled(sk);
	395	}
7c657876	396
2d0817d1 ACM	397	extern int dccp_insert_options(struct sock sk, struct sk_buff skb);
2d0817d1 ACM	398	extern int dccp_insert_option_elapsed_time(struct sock *sk,
7c657876 ACM	399	struct sk_buff *skb,
7c657876 ACM	400	u32 elapsed_time);
2d0817d1	401	extern int dccp_insert_option_timestamp(struct sock *sk,
d4b81ff7	402	struct sk_buff *skb);
2d0817d1	403	extern int dccp_insert_option(struct sock sk, struct sk_buff skb,
7c657876 ACM	404	unsigned char option,
	405	const void *value, unsigned char len);
	406
b0e56780 ACM	407	extern void dccp_timestamp(const struct sock sk, struct timeval tv);
b0e56780 ACM	408
b6ee3d4a ACM	409	static inline suseconds_t timeval_usecs(const struct timeval *tv)
	410	{
	411	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
	412	}
	413
	414	static inline suseconds_t timeval_delta(const struct timeval *large,
	415	const struct timeval *small)
	416	{
	417	time_t secs = large->tv_sec - small->tv_sec;
	418	suseconds_t usecs = large->tv_usec - small->tv_usec;
	419
	420	if (usecs < 0) {
	421	secs--;
	422	usecs += USEC_PER_SEC;
	423	}
	424	return secs * USEC_PER_SEC + usecs;
	425	}
	426
	427	static inline void timeval_add_usecs(struct timeval *tv,
	428	const suseconds_t usecs)
	429	{
	430	tv->tv_usec += usecs;
	431	while (tv->tv_usec >= USEC_PER_SEC) {
	432	tv->tv_sec++;
	433	tv->tv_usec -= USEC_PER_SEC;
	434	}
	435	}
	436
	437	static inline void timeval_sub_usecs(struct timeval *tv,
	438	const suseconds_t usecs)
	439	{
	440	tv->tv_usec -= usecs;
	441	while (tv->tv_usec < 0) {
	442	tv->tv_sec--;
	443	tv->tv_usec += USEC_PER_SEC;
	444	}
0f9e5b57	445	DCCP_BUG_ON(tv->tv_sec < 0);
b6ee3d4a ACM	446	}
b6ee3d4a ACM	447
e55d912f ACM	448	#ifdef CONFIG_SYSCTL
	449	extern int dccp_sysctl_init(void);
	450	extern void dccp_sysctl_exit(void);
	451	#else
	452	static inline int dccp_sysctl_init(void)
	453	{
	454	return 0;
	455	}
	456
	457	static inline void dccp_sysctl_exit(void)
	458	{
	459	}
	460	#endif
	461
7c657876	462	#endif /* _DCCP_H */